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+</HEAD>
+<BODY>
+<P>YAFFS Todo</P>
+<OL>
+ <LI><P>Locking</P>
+ <LI><P>Fix statfs. df does not give correct results.</P>
+ <LI><P>Fix disk full condition.
+ </P>
+ <LI><P>ECC and write failure handling.</P>
+ <LI><P>Add symlinks and links to VFS interface.</P>
+ <LI><P>Add memory mapping (to allow file execution).</P>
+ <LI><P>Test with nandemul mtd.</P>
+ <LI><P>Discuss improved NAND page interface with mtd group.</P>
+</OL>
+<P>NANDEmul MTD</P>
+<OL>
+ <LI><P>Complete and test.</P>
+ <LI><P></P>
+ <P></P>
+</OL>
+<P><BR><BR>
+</P>
+</BODY>
+</HTML>
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+<HEAD>
+ <META HTTP-EQUIV="CONTENT-TYPE" CONTENT="text/html; charset=iso-8859-1">
+ <TITLE></TITLE>
+ <META NAME="GENERATOR" CONTENT="StarOffice/5.2 (Linux)">
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+ <META NAME="CHANGEDBY" CONTENT=" ">
+ <META NAME="CHANGED" CONTENT="20020128;21063000">
+</HEAD>
+<BODY>
+<H1 ALIGN=CENTER>YAFFS (yet another Flash File System)</H1>
+<H4 ALIGN=LEFT>Version 0.3<BR>Charles Manning (and Wookey), December 2001</H4>
+<P ALIGN=LEFT><BR><BR>
+</P>
+<H2>Revision History</H2>
+<TABLE WIDTH=548 BORDER=1 CELLPADDING=4 CELLSPACING=3>
+ <COL WIDTH=88>
+ <COL WIDTH=72>
+ <COL WIDTH=350>
+ <THEAD>
+ <TR>
+ <TH WIDTH=88 VALIGN=TOP>
+ <P ALIGN=LEFT STYLE="font-style: normal">V0.0</P>
+ </TH>
+ <TH WIDTH=72 VALIGN=BOTTOM SDVAL="37245" SDNUM="5129;0;D/MM/YY">
+ <P ALIGN=LEFT STYLE="font-style: normal">20/12/01</P>
+ </TH>
+ <TH WIDTH=350 VALIGN=TOP>
+ <P ALIGN=LEFT STYLE="font-style: normal">First draft</P>
+ </TH>
+ </TR>
+ </THEAD>
+ <TBODY>
+ <TR>
+ <TD WIDTH=88 VALIGN=TOP>
+ <P ALIGN=LEFT STYLE="font-style: normal">V0.1</P>
+ </TD>
+ <TD WIDTH=72 VALIGN=BOTTOM SDVAL="37267" SDNUM="5129;0;D/MM/YY">
+ <P ALIGN=LEFT STYLE="font-style: normal">11/01/02</P>
+ </TD>
+ <TD WIDTH=350 VALIGN=TOP>
+ <P ALIGN=LEFT STYLE="font-style: normal">Minor corrections &
+ cosmetics.<BR>Change use of data status byte.</P>
+ </TD>
+ </TR>
+ <TR>
+ <TD WIDTH=88 VALIGN=TOP>
+ <P ALIGN=LEFT STYLE="font-style: normal">V0.2</P>
+ </TD>
+ <TD WIDTH=72 VALIGN=BOTTOM SDVAL="37284" SDNUM="5129;0;D/MM/YY">
+ <P ALIGN=RIGHT STYLE="font-style: normal">28/01/02</P>
+ </TD>
+ <TD WIDTH=350 VALIGN=TOP>
+ <P ALIGN=LEFT STYLE="font-style: normal">Added observations about
+ inodes, file headers and hard links.</P>
+ </TD>
+ </TR>
+ <TR>
+ <TD WIDTH=88 VALIGN=TOP>
+ <P ALIGN=LEFT STYLE="font-style: normal">V0.3</P>
+ </TD>
+ <TD WIDTH=72 VALIGN=BOTTOM SDVAL="37285" SDNUM="5129;0;D/MM/YY">
+ <P ALIGN=RIGHT STYLE="font-style: normal">26/02/02</P>
+ </TD>
+ <TD WIDTH=350 VALIGN=TOP>
+ <P ALIGN=LEFT STYLE="font-style: normal">W:Added some general
+ observations on compatibility, partitions and bootloading.</P>
+ </TD>
+ </TR>
+ </TBODY>
+</TABLE>
+<P ALIGN=LEFT><BR><BR>
+</P>
+<H2>Scope</H2>
+<P>The purpose of this document is to outline a potential
+NAND-friendly file system for Linux.</P>
+<H2>Background</H2>
+<P>There are already various flash-file systems (FFSs) or block
+drivers for flash (on top of which a regular FS runs). There are pros
+and cons with all of these.
+</P>
+<P>Flash memory has quite a few constraints which will not be
+addressed here. Various approaches are available to work around these
+constraints to provide a file system. It is important to recognise
+that "flash" includes both NOR and NAND flash which have
+different sets of constraints. It is easy to be mislead by the
+generic term "flash" into thinking that approaches
+appropriate for NOR flash are immediately suitable for NAND flash.</P>
+<P>The NAND block drivers (eg. SmartMedia [currently not available
+for Linux] and DiskOnChip NFTL) typically use FAT16 as the file
+system. This isn't too robust and nor is it that flash-friendly.
+These block drivers provide a logical to physical mapping layer to
+emulate rewritable blocks that look like disk sectors. When used with
+FAT16, these file systems work reasonably well. They have a low
+memory footprint and scale well. Like all FAT based systems they are
+prone to corruption ("lost clusters etc").</P>
+<P>The other approach is to design an entire file system which does
+not work through a block driver layer and is flash-friendly. This
+allows more scope to work around issues.</P>
+<P>Currently, two Linux file systems that support NOR flash very well
+are JFFS and its derivative JFFS2. Both of these are based on the
+principles of journaling (hence the leading J) which significantly
+increases robustness - a particularly important feature in embedded
+systems. Unfortunately neither of these file systems scale
+particularly well in both boot time and RAM usage. Scaling is
+particularly relevant when one considers that a 16MB NOR array would
+be considered large while a 128MB NAND is available as a single chip.</P>
+<P>JFFS requires a RAM-based jffs_node structure for each journalling
+node in the flash. Each of these nodes is 48 bytes. JFFS2 makes a
+significant improvement here by reducing the equivalent structure
+(jffs2_raw_node_ref) to 16 bytes. Still, at say an average node-size
+of 512 bytes, a 128MB NAND might need 250000 of these ... 4MB!</P>
+<P>Both JFFS and JFFS2 require scanning the flash array at boot time
+to find the journaling nodes and determine the file structures. Since
+NAND is large, slow, serially accessed and needs ECC this does not
+scale well and will take an unacceptably long boot time for the
+target systems. As a thumb-suck, the scanning of a 128MB NAND array
+might take approx 25 seconds.</P>
+<P>The intentions of the design sketched here are:</P>
+<UL>
+ <LI><P>Be NAND-flash friendly.</P>
+ <LI><P>Robustness through journaling strategies.</P>
+ <LI><P>Significantly reduce the RAM overheads and boot times
+ associated with JFFSx.</P>
+</UL>
+<p>This FS is intended primarily for internal NAND rather than removable NAND
+(SM cards). On removable SM cards Smartmedia compatibility is likely to be
+important so SM/FAT will normally be used, although of course YAFFS makes a
+lot of sense if reliability is more important than compatibility.</p>
+
+<H2>Overview</H2>
+<P>Here follows a simplified overview of YAFFS.</P>
+<P>YAFFS uses a physical flash format similar to SmartMedia. This is
+done for various reasons:</P>
+<UL>
+ <LI><P>Some of the formatting, eg placement of bad block markers is
+ determined by the NAND manufacturers and can't be changed.</P>
+ <LI><P>Potential to reuse code.</P>
+ <LI><P>If it ain't broke don't fix.</P>
+</UL>
+<P>Some of the fields are obviously different to reflect the
+different usage. Despite the similarities YAFFS is not actually compatible
+with SM/FAT. SM cards need to be reformatted to switch from using SM/FAT to
+YAFFS or vice versa.</P>
+<P>File data is stored in fixed size "chunks" consistent
+with the size of a page (ie. 512 bytes). Each page is marked with a
+file id and chunk number. These tags are stored in the "spare
+data" region of the flash. The chunk number is determined by
+dividing the file position by the chunk size.</P>
+<P>When data in a file is overwritten, the relevant chunks are
+replaced by writing new pages to flash containing the new data but
+the same tags. The overwritten data is marked as "discarded".
+</P>
+<P>File "headers" are stored as a single page, marked so as
+to be differentiated from data pages.</P>
+<P>Pages are also marked with a short (2 bit) serial number that
+increments each time the page at this position is incremented. The
+reason for this is that if power loss/crash/other act of demonic
+forces happens before the replaced page is marked as discarded, it is
+possible to have two pages with the same tags. The serial number is
+used to arbitrate.</P>
+<P>A block containing only discarded pages (termed a <I>dirty block</I>)
+is an obvious candidate for garbage collection. Otherwise valid pages
+can be copied off a block thus rendering the whole block discarded
+and ready for garbage collection.</P>
+<P>In theory you don't need to hold the file structure in RAM... you
+could just scan the whole flash looking for pages when you need them.
+In practice though you'd want better file access times than that! The
+mechanism proposed here is to have a list of __u16 page addresses
+associated with each file. Since there are 2<SUP>18</SUP> pages in a
+128MB NAND, a __u16 is insufficient to uniquely identify a page but
+is does identify a group of 4 pages - a small enough region to search
+exhaustively. This mechanism is clearly expandable to larger NAND
+devices - within reason. The RAM overhead with this approach is
+approx 2 bytes per page - 512kB of RAM for a whole 128MB NAND.</P>
+<P>Boot-time scanning to build the file structure lists should
+require just one pass reading NAND. Since only the the spare data
+needs to be read, this should be relatively fast ( approx 3 seconds
+for 128MB). Improvements can be achieved by partitioning the NAND.
+ie. mount the critical partition first then mount the data partition
+afterwards.</P>
+<P>Various runtime improvements can be achieved by changing the
+"chunk size" to 1024 bytes or more. However this would
+likely reduce flash efficiency. As always, life is a compromise....</P>
+<P><BR><BR>
+</P>
+<H3>Spare area details</H3>
+<P>The following table summarizes the layout of the spare area of
+each page.</P>
+<TABLE WIDTH=674 BORDER=1 CELLPADDING=4 CELLSPACING=3>
+ <COL WIDTH=96>
+ <COL WIDTH=249>
+ <COL WIDTH=291>
+ <THEAD>
+ <TR VALIGN=TOP>
+ <TH WIDTH=96>
+ <P>Byte #</P>
+ </TH>
+ <TH WIDTH=249>
+ <P>SmartMedia usage</P>
+ </TH>
+ <TH WIDTH=291>
+ <P>YAFFS usage</P>
+ </TH>
+ </TR>
+ </THEAD>
+ <TBODY>
+ <TR VALIGN=TOP>
+ <TD WIDTH=96>
+ <P>0..511</P>
+ </TD>
+ <TD WIDTH=249>
+ <P>Data</P>
+ </TD>
+ <TD WIDTH=291>
+ <P>Data. either file data or file header depending on tags</P>
+ </TD>
+ </TR>
+ <TR VALIGN=TOP>
+ <TD WIDTH=96>
+ <P>512..515</P>
+ </TD>
+ <TD WIDTH=249>
+ <P>Reserved</P>
+ </TD>
+ <TD WIDTH=291>
+ <P>Tags</P>
+ </TD>
+ </TR>
+ <TR>
+ <TD WIDTH=96 VALIGN=BOTTOM SDVAL="516" SDNUM="5129;">
+ <P ALIGN=RIGHT>516</P>
+ </TD>
+ <TD WIDTH=249 VALIGN=TOP>
+ <P>Data status byte. Not used in SM code from Samsung</P>
+ </TD>
+ <TD WIDTH=291 VALIGN=TOP>
+ <P>Data status byte. If more than 4 bits are zero, then this page
+ is discarded.</P>
+ </TD>
+ </TR>
+ <TR>
+ <TD WIDTH=96 VALIGN=BOTTOM SDVAL="517" SDNUM="5129;">
+ <P ALIGN=RIGHT>517</P>
+ </TD>
+ <TD WIDTH=249 VALIGN=TOP>
+ <P>Block status byte</P>
+ </TD>
+ <TD WIDTH=291 VALIGN=TOP>
+ <P>Block status byte</P>
+ </TD>
+ </TR>
+ <TR VALIGN=TOP>
+ <TD WIDTH=96>
+ <P ALIGN=LEFT>518..519</P>
+ </TD>
+ <TD WIDTH=249>
+ <P>Block address</P>
+ </TD>
+ <TD WIDTH=291>
+ <P>Tags</P>
+ </TD>
+ </TR>
+ <TR VALIGN=TOP>
+ <TD WIDTH=96>
+ <P ALIGN=LEFT>520..522</P>
+ </TD>
+ <TD WIDTH=249>
+ <P>ECC on second 256 bytes part of data</P>
+ </TD>
+ <TD WIDTH=291>
+ <P>ECC on second 256 bytes of data</P>
+ </TD>
+ </TR>
+ <TR VALIGN=TOP>
+ <TD WIDTH=96>
+ <P ALIGN=LEFT>523..524</P>
+ </TD>
+ <TD WIDTH=249>
+ <P>Block address</P>
+ </TD>
+ <TD WIDTH=291>
+ <P>Tags</P>
+ </TD>
+ </TR>
+ <TR VALIGN=TOP>
+ <TD WIDTH=96>
+ <P ALIGN=LEFT>525..527</P>
+ </TD>
+ <TD WIDTH=249>
+ <P>ECC on first 256 bytes part of data</P>
+ </TD>
+ <TD WIDTH=291>
+ <P>ECC on first 256 bytes part of data</P>
+ </TD>
+ </TR>
+ </TBODY>
+</TABLE>
+<P><BR><BR>
+</P>
+<P>The block status is a reserved value that shows whether the block
+is damaged.</P>
+<P>The data status tracks whether the page is valid. If less than 4
+bits are zero, then the page is valid otherwise it is discarded.</P>
+<P>There are 8 bytes (64 bits) for use by YAFFS tags. This is
+partitioned as follows:</P>
+<TABLE WIDTH=596 BORDER=1 CELLPADDING=4 CELLSPACING=3>
+ <COL WIDTH=146>
+ <COL WIDTH=423>
+ <THEAD>
+ <TR VALIGN=TOP>
+ <TH WIDTH=146>
+ <P>Number of bits</P>
+ </TH>
+ <TH WIDTH=423>
+ <P>Usage</P>
+ </TH>
+ </TR>
+ </THEAD>
+ <TBODY>
+ <TR>
+ <TD WIDTH=146 VALIGN=BOTTOM SDVAL="18" SDNUM="5129;">
+ <P ALIGN=RIGHT>18</P>
+ </TD>
+ <TD WIDTH=423 VALIGN=TOP>
+ <P>18-bit file id. ie. Limit of 2<SUP>18</SUP> (over 260000)
+ files. File id 0 is not valid and indicates a deleted page. File
+ Id 0x3FFFF i is also not valid.</P>
+ </TD>
+ </TR>
+ <TR>
+ <TD WIDTH=146 VALIGN=BOTTOM SDVAL="2" SDNUM="5129;">
+ <P ALIGN=RIGHT>2</P>
+ </TD>
+ <TD WIDTH=423 VALIGN=TOP>
+ <P ALIGN=LEFT>2-bit serial number.</P>
+ </TD>
+ </TR>
+ <TR>
+ <TD WIDTH=146 VALIGN=BOTTOM SDVAL="20" SDNUM="5129;">
+ <P ALIGN=RIGHT>20</P>
+ </TD>
+ <TD WIDTH=423 VALIGN=TOP>
+ <P>20-bit page id within file. Limit of 2<SUP>20</SUP> pages per
+ file. ie. over 500MB file max size. Page id 0 means the file
+ header for this file.</P>
+ </TD>
+ </TR>
+ <TR>
+ <TD WIDTH=146 VALIGN=BOTTOM SDVAL="10" SDNUM="5129;">
+ <P ALIGN=RIGHT>10</P>
+ </TD>
+ <TD WIDTH=423 VALIGN=TOP>
+ <P>10-bit counter of the number of bytes used in the page.</P>
+ </TD>
+ </TR>
+ <TR>
+ <TD WIDTH=146 VALIGN=BOTTOM SDVAL="12" SDNUM="5129;">
+ <P ALIGN=RIGHT>12</P>
+ </TD>
+ <TD WIDTH=423 VALIGN=TOP>
+ <P>12-bit ECC on tags.</P>
+ </TD>
+ </TR>
+ <TR>
+ <TD WIDTH=146 VALIGN=BOTTOM SDVAL="2" SDNUM="5129;">
+ <P ALIGN=RIGHT>2</P>
+ </TD>
+ <TD WIDTH=423 VALIGN=TOP>
+ <P>Unused. Keep as 1.</P>
+ </TD>
+ </TR>
+ <TR>
+ <TD WIDTH=146 VALIGN=BOTTOM SDVAL="64" SDNUM="5129;">
+ <P ALIGN=RIGHT><B>64</B></P>
+ </TD>
+ <TD WIDTH=423 VALIGN=TOP>
+ <P><B>Total</B></P>
+ </TD>
+ </TR>
+ </TBODY>
+</TABLE>
+<P><BR><BR>
+</P>
+<P>A bit of explanation on the usage of some of these fields:</P>
+<P>file Id is synonymous with inode.</P>
+<P>The serial number is incremented each time a page with the same
+file_id:page_id is rewritten (because of data changes or copy during
+garbage collection). When a page is replaced, there is a brief period
+during which there are two pages with the same id. The serial number
+resolves this. Since there should never be a difference of less than
+more than one, a two-bit counter is sufficient to determine which is
+the current page.</P>
+<P>When the page is rewritten, the file id, these data status byte
+and the 12-bit ECC are all written to zero.</P>
+<P>The byte counter indicates how many bytes are valid in this page.
+Since the page would not exist if it contains zero bytes, this field
+should thus hold 512 for all pages except the last page in the file.
+The use of counters means that the file length integrity is preserved
+while the file is open without having to constantly update the file
+length in the file header. The file header only needs to be refreshed
+when the file is closed (rather than whenever it is appended to).
+This field is wide enough to allow expansion to 1024-byte "chunks".</P>
+<P>File "headers" come in two flavours:</P>
+<UL>
+ <LI><P>file info ( the mode, ower id, group id, length,...)</P>
+ <LI><P>the hard link(s) that refers to the file.</P>
+</UL>
+<P>A directory also appears as a file (ie. has an inode and hard
+link(s)) but has no data.</P>
+<P>The 12-bit ECC applies to only the tag data uses a similar
+algorithm to the 22-bit ECCs used for file system data. They are kept
+independent.</P>
+<H3>RAM data details</H3>
+<P>Block management details are reasonably obvious and, I feel, don't
+need to be addressed here apart from stating that there will be a
+structure to track block status (eg. number of pages in use, failed
+blocks, and which are candidates for garbage collection etc).</P>
+<P>The files need an indexing structure of sorts to locate and track
+the pages in the file. Some sort of tree structure should work rather
+well. The look-up needs to be quite efficient in both CPU time and
+space.</P>
+<H3>Page allocation and garbage collection</H3>
+<P>Pages are allocated sequentially from the currently selected
+block. When all the pages in the block are filled, another clean
+block is selected for allocation. At least two or three clean blocks
+are reserved for garbage collection purposes. If there are
+insufficient clean blocks available, then a dirty block ( ie one
+containing only discarded pages) is erased to free it up as a clean
+block. If no dirty blocks are available, then the dirtiest block is
+selected for garbage collection.</P>
+<P>Garbage collection is performed by copying the valid data pages
+into new data pages thus rendering all the pages in this block dirty
+and freeing it up for erasure. I also like the idea of selecting a
+block at random some small percentage of the time - thus reducing the
+chance of wear differences.</P>
+<P>Relative to NOR, NAND writes and erases very fast. Therefore
+garbage collection might be performed on-demand (eg. during a write)
+without significant degradation in performance. Alternatively garbage
+collection might be delegated to a kernel tasklet.</P>
+<P>Relative to JFFSx, the garbage collection presented here is
+incredibly simple - thanks mainly to the use of fixed-size pages
+instead of journaling nodes.</P>
+<H3>Flash writing</H3>
+<P>As presented here, YAFFS only writes to the page's data area once
+and to the spare area twice (once when new page is written and once when it
+gets stomped on) before an erasure. This is within the limits of the most
+restrictive NAND flashes.</P>
+
+<H3>Wear leveling</H3>
+<P>No wear leveling is explicitly used here. Instead we rely on two
+"strategies":</P>
+<UL>
+ <LI><P>Reserving some blocks to cater for failure. You need to do
+ this anyway with NAND. The main purpose behind wear leveling is to
+ prevent some blocks getting more wear and failing. Since we expect,
+ and handle, failure this is no longer as important.</P>
+ <LI><P>The infrequent random block selection should prevent low-wear
+ blocks getting "stuck".</P>
+</UL>
+<h3>Partitioning</h3>
+<p> Partitioning is not included in this spec, but could be added if
+required.</p>
+<h3>Bootloading</h3>
+<p>Bootloaders cannot just read files direct from NAND due to the high
+probability of bad blocks. Because YAFFS is quite simple it will be
+relatively straightforward for bootloaders to read from it (eg reading a
+kernel).</p>
+
+<H3>Conclusion</H3>
+<P>YAFFS is very simple. It is also NAND-friendly, is relatively
+frugal with resources (especially RAM) and boots quickly. Like JFFSx
+it has journaling which makes it far more robust than FAT.</P>
+<P>While it might seem high-risk to develop YAFFS, it is probably
+about the same amount of effort as implementing changes to JFFS to
+get it to work effectively within the constraints of NAND. A
+resulting JFFSx system would still require significant amounts of RAM
+and have long boot times.</P>
+<P>While YAFFS is indeed a new file system internally, much of the
+file system glue code (including inode management, link management
+etc) can likely be stolen from JFFSx.
+</P>
+<P><BR><BR>
+</P>
+<P><BR><BR>
+</P>
+<P><BR><BR>
+</P>
+<P><BR><BR>
+</P>
+<P><BR><BR>
+</P>
+<P><BR><BR>
+</P>
+<P><BR><BR>
+</P>
+<P><BR><BR>
+</P>
+<P><BR><BR>
+</P>
+</BODY>
+</HTML>
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+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN">
+<HTML>
+<HEAD>
+ <META HTTP-EQUIV="CONTENT-TYPE" CONTENT="text/html; charset=iso-8859-1">
+ <TITLE></TITLE>
+ <META NAME="GENERATOR" CONTENT="StarOffice/5.2 (Linux)">
+ <META NAME="AUTHOR" CONTENT=" ">
+ <META NAME="CREATED" CONTENT="20020429;14311100">
+ <META NAME="CHANGEDBY" CONTENT=" ">
+ <META NAME="CHANGED" CONTENT="20020513;21133100">
+</HEAD>
+<BODY>
+<H1 ALIGN=CENTER>YAFFS Development Notes</H1>
+<P><BR><BR>
+</P>
+<P><BR><BR>
+</P>
+<H3>Build options</H3>
+<P>Yaffs can be built as either a kernel module (ie. a Linux file
+system) or as an application.</P>
+<P>Of course the goal is to build yaffs as a file system running on
+top of real NAND flash, but yaffs can be built to run on a RAM
+emulation layer for in-kernel testing without NAND flash in the
+system.</P>
+<P>Building as an application allows the yaffs_guts algorithms to be
+tested/debugged in a more friendly debugging environment. The test
+harness is in yaffsdev.c</P>
+<H3>Trying it out</H3>
+<P>YAFFS can be built to run with either mtd or RAM emulation, or
+both. The file system that interfaces to mtd is called <B>yaffs</B>,
+the file system that uses internal ram is called <B>yaffsram</B>.
+YAFFS simultaneously supports both if they are enabled.</P>
+<OL>
+ <LI><P>Hack the Makefile and change the KERNELDIR define to your
+ kernel directory.</P>
+ <LI><P>If you don't have mtd support in your kernel, then you might
+ need to turn off USE_MTD otherwise the yaffs module might not load.</P>
+ <LI><P>Type <B><FONT FACE="Courier, monospace">make clean; make</FONT></B>
+ to build yaffs</P>
+ <LI><P>Load yaffs as a module by typing <B><FONT FACE="Courier, monospace">/sbin/insmod
+ yaffs.o</FONT></B> (ya gotta be root!).</P>
+ <LI><P>Create a mount point eg. <B><FONT FACE="Courier, monospace">mkdir
+ /mnt/y</FONT></B></P>
+ <LI><P>To mount the RAM emulation version of yaffs, <B><FONT FACE="Courier, monospace">mount
+ -t yaffsram none /mnt/y</FONT></B></P>
+ <LI><P><FONT FACE="Courier, monospace"><SPAN STYLE="font-weight: medium"><FONT FACE="Times, serif">Alternatively,
+ to mount the mtd version of yaffs,</FONT></SPAN><B> mount -t yaffs
+ /dev/mtd0 /mnt/y</B></FONT></P>
+</OL>
+<P><BR><BR>
+</P>
+<H3>YAFFS Data structures</H3>
+<P>All data types are defined in yaffs_guts.h</P>
+<P>Yaffs uses the following major objects:</P>
+<UL>
+ <LI><P>yaffs_Object: A yaffs_Object can be a file, directory,
+ symlink or hardlink. The yaffs_Objects "know" about their
+ corresponding yaffs_ObjectHeader in NAND and the data for that
+ object. yaffs_Objects also bind together the directory structure as
+ follows:</P>
+ <LI><P>parent: pointer to the yaffs_Object that is a parent of this
+ yaffs_Object in the directory structure.</P>
+ <LI><P>siblings: this field is used to link together a list of all
+ the yaffs_Objects in the same directory.</P>
+ <LI><P>children: if the object is a directory, then children holds
+ the head of the list of objects in the directory.</P>
+ <LI><P>yaffs_Tnode: yaffs_Tnodes form a tree structure that speeds
+ up the search for data chunks in a file. As the file grows in size,
+ the levels increase. The Tnodes are a constant size (32 bytes).
+ Level 0 (ie the lowest level) comprise 16 2-byte entries giving an
+ index used to search for the chunkId. Tnodes at other levels
+ comprise 8 4-byte pointer entries to other tnodes lower in the tree.</P>
+ <LI><P>yaffs_Device: this holds the device context and is in some
+ ways analogous to the VFS superblock. It stores the data used to
+ access the mtd as well as function pointers to access the NAND data.</P>
+</UL>
+<P>The Tnodes and Objects are allocated in groups to reduce memory
+allocation/freeing overheads. Freed up tnodes and objects are kept in
+a free list and re-used.</P>
+<H3>yaffs_Object</H3>
+<P><BR><BR>
+</P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2>struct
+ yaffs_ObjectStruct</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2>{</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> __u8
+fake:1; // A fake object has no presence on NAND.</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> __u8
+renameAllowed:1; // Are we allowed to rename it?</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> __u8
+unlinkAllowed:1; // Are we allowed to unlink it?</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> __u8
+dirty:1; // the object needs to be written to flash</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> __u8
+valid:1; // When the file system is being loaded up, this </FONT></FONT>
+</P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2>
+ // object might be created before the data</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2>
+ // is available (ie. file data records appear before the header).</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> __u8
+serial; // serial number of chunk in NAND. Store here so we
+don't have to</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2>
+ // read back the old one to update.</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> __u16
+sum; // sum of the name to speed searching</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> </FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> struct
+yaffs_DeviceStruct *myDev; // The device I'm on</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> </FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> </FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> struct
+list_head hashLink; // list of objects in this hash bucket</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> </FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><BR>
+</P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> struct
+list_head hardLinks; // all the equivalent hard linked objects</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> //
+live on this list</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> //
+directory structure stuff</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> struct
+yaffs_ObjectStruct *parent; //my parent directory</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> struct
+list_head siblings; // siblings in a directory</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2>
+// also used for linking up the free list</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> </FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> //
+Where's my data in NAND?</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> int
+chunkId; // where it lives</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> </FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> __u32
+objectId; // the object id value</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> </FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> </FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> __u32
+st_mode; // protection</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> __u32
+st_uid; // user ID of owner</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> __u32
+st_gid; // group ID of owner </FONT></FONT>
+</P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> __u32
+st_atime; // time of last access</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> __u32
+st_mtime; // time of last modification</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> __u32
+st_ctime; // time of last change</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><BR>
+</P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> </FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> yaffs_ObjectType
+variantType;</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> </FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> yaffs_ObjectVariant
+variant;</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> </FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2>};</FONT></FONT></P>
+<P><BR><BR>
+</P>
+<P>Obvious stuff skipped....</P>
+<P>fake, renameAllowed, unlinkAllowed are special flags for handling
+"fake" objects which live in the file system but do not
+live on NAND. Currently there are only two such objects: the root
+object and the lost+found directory. None of these may be renamed or
+unlinked.</P>
+<P>serial, sum: see yaffs_ObjectHeader.</P>
+<P>dirty indicates that the object's contents has changed and a new
+yaffs_ObjectHeader must be written to flash.</P>
+<P>valid indicates that the object has been loaded up. This is only
+used during scanning (yaffs_Scan()) since we can know of an object's
+existance - and thus need to create the object header - before we
+encounter the associated yaffs_ObjectHeader.</P>
+<P>hashlink is a list of Objects in the same hash bucket.
+</P>
+<P>The four variants hold extra info:</P>
+<P>Files hold the file size and the top level and pointer to the
+tnode tree for the file.</P>
+<P>Directories hold a list of children objects.</P>
+<P>Symlinks hold a pointer to the alias string. This is probably
+inefficient, but that probably does not matter since we don't expect
+to see many of these.
+</P>
+<P>Hardlinks hold information to identify the equivalent object.</P>
+<P><BR><BR>
+</P>
+<P><BR><BR>
+</P>
+<H3>File structure (tnodes)</H3>
+<P>File structures are done with a tiered indexing structure</P>
+<P><BR><BR>
+</P>
+<P><IMG SRC="sv9349341.gif" NAME="Graphic2" ALIGN=LEFT WIDTH=491 HEIGHT=294 BORDER=0><BR CLEAR=LEFT><BR><BR>
+</P>
+<P>The file structure is maintained by a tree structure. Depending
+where it is in the tree, each tree node (<B><I>tnode</I></B>) (the
+blue/things) holds either:</P>
+<UL>
+ <LI><P>.... if it is at the lowest level, then 16 __u16s which
+ identify the page.</P>
+ <LI><P>.... if it is at a higher level (ie an internal tnode), then
+ 8 pointers to lowest-level tnodes.</P>
+</UL>
+<P>When the file starts out, it is assigned only one low-level tnode.
+When the file expands past what a single tnode can hold, then it is
+assigned a second tnode and an internal node is added to point to the
+two tnodes. As the file grows, more low-level tnodes and high level
+tnodes are added.</P>
+<P>Traversing the tnode tree to find a particular page in a file is
+quite simple: each internal tnode is selected from by using 3 bits of
+the page offset in the file. The level 0 page resolves 4 bits.</P>
+<P>For example, finding page 0x235 (ie. the one starting at file
+position 0x46800 would proceed as follows:</P>
+<P>0x235 is 0000001000110101, partitioned as follows.
+000.000.100.011.0101</P>
+<TABLE WIDTH=496 BORDER=1 CELLPADDING=4 CELLSPACING=3>
+ <COL WIDTH=140>
+ <COL WIDTH=160>
+ <COL WIDTH=158>
+ <THEAD>
+ <TR VALIGN=TOP>
+ <TH WIDTH=140>
+ <P>Level</P>
+ </TH>
+ <TH WIDTH=160>
+ <P>Bits</P>
+ </TH>
+ <TH WIDTH=158>
+ <P>Selected value</P>
+ </TH>
+ </TR>
+ </THEAD>
+ <TBODY>
+ <TR VALIGN=TOP>
+ <TD WIDTH=140>
+ <P>3 or more if they exist</P>
+ </TD>
+ <TD WIDTH=160>
+ <P>>= 10</P>
+ </TD>
+ <TD WIDTH=158>
+ <P>Zero</P>
+ </TD>
+ </TR>
+ <TR>
+ <TD WIDTH=140 VALIGN=BOTTOM SDVAL="2" SDNUM="5129;">
+ <P ALIGN=RIGHT>2</P>
+ </TD>
+ <TD WIDTH=160 VALIGN=TOP>
+ <P ALIGN=LEFT>9 to 7</P>
+ </TD>
+ <TD WIDTH=158 VALIGN=TOP>
+ <P>100 binary = 4</P>
+ </TD>
+ </TR>
+ <TR>
+ <TD WIDTH=140 VALIGN=BOTTOM SDVAL="1" SDNUM="5129;">
+ <P ALIGN=RIGHT>1</P>
+ </TD>
+ <TD WIDTH=160 VALIGN=TOP>
+ <P ALIGN=LEFT>6 to 4</P>
+ </TD>
+ <TD WIDTH=158 VALIGN=TOP>
+ <P>011 binary = 3</P>
+ </TD>
+ </TR>
+ <TR>
+ <TD WIDTH=140 VALIGN=BOTTOM SDVAL="0" SDNUM="5129;">
+ <P ALIGN=RIGHT>0</P>
+ </TD>
+ <TD WIDTH=160 VALIGN=TOP>
+ <P ALIGN=LEFT>3 to 0</P>
+ </TD>
+ <TD WIDTH=158 VALIGN=TOP>
+ <P>0101 binary = 5</P>
+ </TD>
+ </TR>
+ </TBODY>
+</TABLE>
+<P><BR><BR>
+</P>
+<P>Free tnodes are stored in a list. When the list is exhausted, more
+are allocated.</P>
+<P>Each tnode takes 32 bytes. Each file needs at least one level 0
+tnode. How many do we need? A full 16MB file system needs at least
+16MB/512/16 = 2000 level zero tnodes. More for internal tnodes. More
+for files smaller than optimal.</P>
+<P>The tree grows as required. When the file is resized to a smaller
+size then it is pruned.</P>
+<P><BR><BR>
+</P>
+<H3>NAND data</H3>
+<P>Data is stored on NAND in "chunks". Currently each chunk
+is the same size as a NAND flash page (ie. 512 bytes + 16 byte
+spare). In the future we might decide to allow for different chunk
+sizes. Chunks can hold either:</P>
+<UL>
+ <LI><P>A yaffs_ObjectHeader. This is the way a yaffs_Object gets
+ stored on NAND.</P>
+ <LI><P>A chunk of file data.</P>
+</UL>
+<P>The 16 byte spare area contains:</P>
+<UL>
+ <LI><P>8 bytes of tags,</P>
+ <LI><P>6 bytes of ECC data</P>
+ <LI><P>1 byte block status (used to identify damaged blocks)</P>
+ <LI><P>1 byte data status (currently unused).</P>
+</UL>
+<P>The tags are made up as follows:</P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2>typedef
+struct</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2>{</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2>
+ unsigned chunkId:20; //chunk number in file</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2>
+ unsigned serialNumber:2; //serial number for chunk</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2>
+ unsigned byteCount:10; //number of bytes of data used in this
+chunk</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2>
+ unsigned objectId:18; //the object id that this chunk belongs
+to. </FONT></FONT>
+</P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2>
+ unsigned ecc:12; //ECC on tags</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2>
+ unsigned unusedStuff:2; //unused</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2>}
+yaffs_Tags;</FONT></FONT></P>
+<P STYLE="margin-bottom: 0cm"><BR>
+</P>
+<P>A chunkId of zero indicates that this chunk holds a
+yaffs_ObjectHeader. A non zero value indicates that this is a data
+chunk and the position of the chunk in the file (ie. the first chunk
+- at offset 0 - has chunkId 1). See yaffs_guts.c:yaffs_Scan () to see
+how this is done.</P>
+<P>When a chunk is repalced (eg. file details changed or a part of a
+file was overwritten), the new chunk is written before the old chunk
+is deleted. This means that we don't lose data if there is a power
+loss after the new chunk is created but before the old one is
+discarded, but it does mean that we can encounter the situation where
+we find both the old and the new chunks in flash. The serialNumber is
+incremented each time the chunk is written. 2 bits is sufficient to
+resolve any ambiguity.</P>
+<P>bytecount applies only to data chunks and tells how many of the
+data bytes are valid.</P>
+<P>objectId says which object this chunk belongs to.</P>
+<P>ecc is used to perform error correction on the tags. Another ecc
+field is used to error correct the data.</P>
+<P><BR><BR>
+</P>
+<H3>yaffs_ObjectHeader</H3>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2>typedef
+struct</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2>{</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> yaffs_ObjectType
+type;</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><BR>
+</P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> //
+Apply to everything </FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> int
+ parentObjectId;</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> __u16
+sum; // checksum of name</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> char
+ name[YAFFS_MAX_NAME_LENGTH + 1];</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><BR>
+</P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> //
+Thes following apply to directories, files, symlinks - not hard links</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> __u32
+st_mode; // protection</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> __u32
+st_uid; // user ID of owner</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> __u32
+st_gid; // group ID of owner </FONT></FONT>
+</P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> __u32
+st_atime; // time of last access</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> __u32
+st_mtime; // time of last modification</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> __u32
+st_ctime; // time of last change</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> </FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> //
+File size applies to files only</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> int
+fileSize; </FONT></FONT>
+</P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> </FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> //
+Equivalent object id applies to hard links only.</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> int
+ equivalentObjectId;</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2>
+ // alias only applies to symlinks</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> char
+alias[YAFFS_MAX_ALIAS_LENGTH + 1];</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> </FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2> </FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><FONT FACE="Courier, monospace"><FONT SIZE=2>}
+yaffs_ObjectHeader;</FONT></FONT></P>
+<P STYLE="margin-left: 2cm; margin-bottom: 0cm"><BR>
+</P>
+<P>A yaffs_ObjectHeader is stored in NAND for every yaffs_Object.</P>
+<P>type holds the type of yaffs_Object (file,directory,hardlink or
+symlink).</P>
+<P>parentObject is the objectId of this object's parent. name holds
+the object's name. Together these form the directory structure of the
+file system. Also worth mention is sum. This is a "checksum"
+on the name which speeds directory searching (ie. when searching the
+directory we only compare the name for those entries where sum
+matches).</P>
+<P>Obvious stuff skipped....</P>
+<P>equivalentObjectId is used by hardlinks. A hardlink to an object
+uses this field to specify the object that this links to. This way of
+doing things is a bit different than the normal Linux way of doing
+things (ie. keeping the links distinct from the inode) but is simpler
+and uses less space except for a few corner cases with hardlinks.</P>
+<P>alias is used by symlinks to hold the symlink alias string. This
+limits the size of the symlink alias. In future we should expand
+YAFFS to use data chunks to store aliases too long to fit into the
+yaffs_ObjectHeader.</P>
+<P><BR><BR>
+</P>
+<H3>NAND Interface</H3>
+<P>All NAND access is performed via four functions pointed to by
+yaffs_Device. At the moment a chunk is a page.</P>
+<UL>
+ <LI><P><FONT FACE="Courier, monospace"><FONT SIZE=2>int
+ WriteChunkToNAND(struct yaffs_DeviceStruct *dev,int chunkInNAND,
+ const __u8 *data, yaffs_Spare *spare)</FONT></FONT></P>
+ <LI><P><FONT FACE="Courier, monospace"><FONT SIZE=2>int
+ ReadChunkFromNAND(struct yaffs_DeviceStruct *dev,int chunkInNAND,
+ __u8 *data, yaffs_Spare *spare);</FONT></FONT></P>
+ <LI><P><FONT FACE="Courier, monospace"><FONT SIZE=2>int
+ EraseBlockInNAND(struct yaffs_DeviceStruct *dev,int blockInNAND);</FONT></FONT></P>
+ <LI><P><FONT FACE="Courier, monospace"><FONT SIZE=2>int
+ InitialiseNAND(struct yaffs_DeviceStruct *dev);</FONT></FONT></P>
+</UL>
+<P>In the Readxxx and Writexxx functions, the data and/or spare
+pointers may be NULL in which case these data transfers are ignored.</P>
+<P>A quick note about NAND:</P>
+<UL>
+ <LI><P>NAND is not random access, but page oriented. Thus, we do all
+ reads & writes in pages.</P>
+ <LI><P>Each NAND page holds 512 bytes of data and 16 "spare"
+ bytes. Yaffs structures the spare area with tags used to identify
+ what is stored in the data area. There are 32 such pages to a block.</P>
+ <LI><P>NAND writes will only change 1 bits to 0. eg. if a byte holds
+ 10110011 and you write 11011010 to it you will get the logical and
+ of the two values: 10010010. The only way to get 1s again is to
+ erase the entire block.
+ </P>
+ <LI><P>You may only write to a page a few times before erasing the
+ entire block. Yaffs lives within these limitations. Each page only
+ gets written to twice (once when written and once when discarded).</P>
+ <LI><P>ECC is normally used with NAND to correct for single bit
+ errors. YAFFS applies the ECC itself, so the MTD should not do this.</P>
+ <LI><P>The current mtd interfaces are not particularly well suited
+ to YAFFS and we will address the issue with the mtd group. (The mtd
+ interface does not support page-oriented read/write which YAFFS
+ would prefer).</P>
+</UL>
+<P><BR><BR>
+</P>
+<H3>mkyaffs</H3>
+<P>mkyaffs is the tool to format a NAND mtd to be used for YAFFS.
+This is quite simple, just erase all the undamaged blocks. YAFFS
+treats erased blocks as free (empty) space.</P>
+<P><BR><BR>
+</P>
+<H2>Expected performance</H2>
+<P>The following numbers should give an indication of the performance
+we should expect from YAFFS.</P>
+<P>As an example, I'll use the following numbers. Since the hardware
+is capable of 50ns read/write, these numbers allow for some other
+ovberheads. Clearly though, the performance can be degraded in
+various ways.</P>
+<TABLE WIDTH=233 BORDER=1 CELLPADDING=4 CELLSPACING=3>
+ <COL WIDTH=103>
+ <COL WIDTH=103>
+ <THEAD>
+ <TR VALIGN=TOP>
+ <TH WIDTH=103>
+ <P ALIGN=LEFT STYLE="font-style: normal">Seek</P>
+ </TH>
+ <TH WIDTH=103>
+ <P ALIGN=LEFT STYLE="font-style: normal">10uS/page</P>
+ </TH>
+ </TR>
+ </THEAD>
+ <TBODY>
+ <TR VALIGN=TOP>
+ <TD WIDTH=103>
+ <P ALIGN=LEFT STYLE="font-style: normal">Read</P>
+ </TD>
+ <TD WIDTH=103>
+ <P ALIGN=LEFT STYLE="font-style: normal">100nS/byte</P>
+ </TD>
+ </TR>
+ <TR VALIGN=TOP>
+ <TD WIDTH=103>
+ <P ALIGN=LEFT STYLE="font-style: normal">Write</P>
+ </TD>
+ <TD WIDTH=103>
+ <P ALIGN=LEFT STYLE="font-style: normal">100nS/byte</P>
+ </TD>
+ </TR>
+ <TR VALIGN=TOP>
+ <TD WIDTH=103>
+ <P ALIGN=LEFT STYLE="font-style: normal">Program</P>
+ </TD>
+ <TD WIDTH=103>
+ <P ALIGN=LEFT STYLE="font-style: normal">200uS/page</P>
+ </TD>
+ </TR>
+ <TR VALIGN=TOP>
+ <TD WIDTH=103>
+ <P ALIGN=LEFT STYLE="font-style: normal">Erase</P>
+ </TD>
+ <TD WIDTH=103>
+ <P ALIGN=LEFT STYLE="font-style: normal">2mS/block</P>
+ </TD>
+ </TR>
+ </TBODY>
+</TABLE>
+<P><BR><BR>
+</P>
+<P>From this we can derive some higher-level numbers:</P>
+<TABLE WIDTH=706 BORDER=1 CELLPADDING=4 CELLSPACING=3>
+ <COL WIDTH=204>
+ <COL WIDTH=160>
+ <COL WIDTH=304>
+ <THEAD>
+ <TR VALIGN=TOP>
+ <TH WIDTH=204>
+ <P>Operation</P>
+ </TH>
+ <TH WIDTH=160>
+ <P>Time</P>
+ </TH>
+ <TH WIDTH=304>
+ <P>Calculation</P>
+ </TH>
+ </TR>
+ </THEAD>
+ <TBODY>
+ <TR VALIGN=TOP>
+ <TD WIDTH=204>
+ <P>Read spare</P>
+ </TD>
+ <TD WIDTH=160>
+ <P>12uS</P>
+ </TD>
+ <TD WIDTH=304>
+ <P>seek + 16 * read</P>
+ </TD>
+ </TR>
+ <TR VALIGN=TOP>
+ <TD WIDTH=204>
+ <P>Read page</P>
+ </TD>
+ <TD WIDTH=160>
+ <P>63 uS</P>
+ </TD>
+ <TD WIDTH=304>
+ <P>seek + 528 * read</P>
+ </TD>
+ </TR>
+ <TR VALIGN=TOP>
+ <TD WIDTH=204>
+ <P>Write page</P>
+ </TD>
+ <TD WIDTH=160>
+ <P>326 uS</P>
+ </TD>
+ <TD WIDTH=304>
+ <P>seek + 528 * write + program + read page (for verification)</P>
+ </TD>
+ </TR>
+ <TR VALIGN=TOP>
+ <TD WIDTH=204>
+ <P>Discard page</P>
+ </TD>
+ <TD WIDTH=160>
+ <P>212 uS</P>
+ </TD>
+ <TD WIDTH=304>
+ <P>seek + 16 * write + program</P>
+ </TD>
+ </TR>
+ <TR VALIGN=TOP>
+ <TD WIDTH=204>
+ <P>Overwrite page</P>
+ </TD>
+ <TD WIDTH=160>
+ <P>538 uS</P>
+ </TD>
+ <TD WIDTH=304>
+ <P>write page + discard page</P>
+ </TD>
+ </TR>
+ <TR VALIGN=TOP>
+ <TD WIDTH=204>
+ <P>Erase overhead per page</P>
+ </TD>
+ <TD WIDTH=160>
+ <P>63uS</P>
+ </TD>
+ <TD WIDTH=304>
+ <P>erase/32</P>
+ </TD>
+ </TR>
+ </TBODY>
+</TABLE>
+<P><BR><BR>
+</P>
+<P>From this we can infer the following flash access times:</P>
+<TABLE WIDTH=704 BORDER=1 CELLPADDING=4 CELLSPACING=3>
+ <COL WIDTH=196>
+ <COL WIDTH=167>
+ <COL WIDTH=303>
+ <THEAD>
+ <TR VALIGN=TOP>
+ <TH WIDTH=196>
+ <P>Operation</P>
+ </TH>
+ <TH WIDTH=167>
+ <P>Time</P>
+ </TH>
+ <TH WIDTH=303>
+ <P>Calculation</P>
+ </TH>
+ </TR>
+ </THEAD>
+ <TBODY>
+ <TR VALIGN=TOP>
+ <TD WIDTH=196>
+ <P>Read 1MB file</P>
+ </TD>
+ <TD WIDTH=167>
+ <P>0.13s (about 7.5 MB/s)</P>
+ </TD>
+ <TD WIDTH=303>
+ <P>2000 * read page</P>
+ </TD>
+ </TR>
+ <TR VALIGN=TOP>
+ <TD WIDTH=196>
+ <P>Write 1MB (clean system)</P>
+ </TD>
+ <TD WIDTH=167>
+ <P>0.53s (about 1.8 MB/s)</P>
+ </TD>
+ <TD WIDTH=303>
+ <P>2000 * write page</P>
+ </TD>
+ </TR>
+ <TR VALIGN=TOP>
+ <TD WIDTH=196>
+ <P>Overwrite 1MB file (no gc)</P>
+ </TD>
+ <TD WIDTH=167>
+ <P>1.08s (about 0.9MB/s)</P>
+ </TD>
+ <TD WIDTH=303>
+ <P>2000 * overwrite page</P>
+ </TD>
+ </TR>
+ <TR VALIGN=TOP>
+ <TD WIDTH=196>
+ <P>Overwrite 1MB with 50% gc</P>
+ </TD>
+ <TD WIDTH=167>
+ <P>2.4s (about 0.4 MB/s)</P>
+ </TD>
+ <TD WIDTH=303>
+ <P>2000 * overwrite page + 2000 * page copy (== overwrite page) +
+ 4000 * erase overhead</P>
+ </TD>
+ </TR>
+ <TR VALIGN=TOP>
+ <TD WIDTH=196>
+ <P>Delete 1MB file</P>
+ </TD>
+ <TD WIDTH=167>
+ <P>0.43s (about 2.2 MB/s)</P>
+ </TD>
+ <TD WIDTH=303>
+ <P>2000 * discard page</P>
+ </TD>
+ </TR>
+ <TR VALIGN=TOP>
+ <TD WIDTH=196>
+ <P>Delete 1MB file with 50% gc</P>
+ </TD>
+ <TD WIDTH=167>
+ <P>0.49s (about 2.0MB/s)</P>
+ </TD>
+ <TD WIDTH=303>
+ <P>2000 * discard page + 1000 * erase overhead</P>
+ </TD>
+ </TR>
+ </TBODY>
+</TABLE>
+<P><BR><BR>
+</P>
+<P><BR><BR>
+</P>
+<P><BR><BR>
+</P>
+</BODY>
+</HTML>
\ No newline at end of file
--- /dev/null
+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN">
+<HTML>
+<HEAD>
+ <META HTTP-EQUIV="CONTENT-TYPE" CONTENT="text/html; charset=iso-8859-1">
+ <TITLE></TITLE>
+ <META NAME="GENERATOR" CONTENT="StarOffice/5.2 (Linux)">
+ <META NAME="AUTHOR" CONTENT=" ">
+ <META NAME="CREATED" CONTENT="20020211;20201700">
+ <META NAME="CHANGEDBY" CONTENT=" ">
+ <META NAME="CHANGED" CONTENT="20020211;21005100">
+</HEAD>
+<BODY>
+<H3>YAFFS Progress 11 Feb 2002</H3>
+<H3>Approach</H3>
+<P><I>C. A. R. Hoare, in his 1980 ACM Turing Award lecture, told of
+two ways of constructing a software design: "One way is to make
+it so simple that there are obviously no deficiencies and the other
+way is to make it so complicated that there are no obvious
+deficiencies."</I></P>
+<P>The approach I'm taking with Yaffs is to design and make notes up
+front as much as possible. I find this helps make the coding/debug
+phase go way faster and more predictably.</P>
+<P>Although obviously the code ends up in the kernel, I'm abstracting
+out kernel services so that I develop/debug in user space using
+vanilla dev tools. I like to use Source Navigator because it has a
+nice xref capability though a few quirks too). Thus, yaffs code will
+be tested in application space wrapped in a test harness which calls
+the yaffs functions. and sits on top of a NAND emulation layer (just
+two big disk files). I can then do things like force ecc failures
+etc at will to test recovery logic and check booting etc. This
+general approach has served me well in the past and I expect it will
+this time too.</P>
+<H3>Design</H3>
+<P>At this stage all the major design work is done. Basically there
+are 3 in RAM management "objects":</P>
+<UL>
+ <LI><P> inodes: An inode maps to the normal file system concept of
+ an inode. It is thus either a file or a directory. <BR>A file type
+ inode points to a tnode tree which is a layered tree that is used to
+ quickly find the pages of data in NAND.<BR>A directory type inode
+ has a list of children links (ie. the links in that directory).<BR>An
+ inode knows which hard links are associated with it.<BR>inode
+ look-up uses a hashing table.</P>
+ <LI><P>links: Links are hard or soft links. All links have a parent
+ inode (ie. the directory they're in). <BR>Hard links point to an
+ inode.<BR>Soft links are just alias strings.<BR>Instead of storing
+ the link name in RAM (big and wasteful and variable size), the
+ location in NAND is stored instead and a u16 "checksum"
+ value is stored in RAM to help in quickly scanning links [ie. say
+ the checksum for "freddies_file" is 123 then when I go
+ search for it I don't need to go look at every link in NAND (slow),
+ just those that match checksum 123].
+ </P>
+ <LI><P>tnodes: Tnodes are a tiered tree system to rapidly get from
+ inodes to their data pages in RAM.</P>
+</UL>
+<P>There is a need for speed in certain areas, such as rapidly
+locating inodes, links data pages during certain scenarios (eg.
+garbage collection). These have been identified and suitable look-up
+structures are in place.</P>
+<P>All dynamic data structures are allocated from pools rather than
+one at a time. This is more efficient time-wise and simplifies
+clean-up.</P>
+<H3>Code</H3>
+<P>Much of the code for the management layers is already in place, as
+is some of the tag management code. Some of the code has already been
+tested.</P>
+<P>I have started with coding the management layer since this is the
+most critical part to get right. Every now and then I have coded up
+some other section to verify that what I have will work.</P>
+<H3>Time</H3>
+<P>So far I've logged 65 hours on yaffs (though it chews up
+significant null cycles too :-)). I believe this is comfortably
+within budget. I was not able to make much progress through Christmas
+and the week of January, but am able to give a lot more effort now.</P>
+<P><BR><BR>
+</P>
+<P><BR><BR>
+</P>
+</BODY>
+</HTML>
\ No newline at end of file
--- /dev/null
+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN">
+<HTML>
+<HEAD>
+ <META HTTP-EQUIV="CONTENT-TYPE" CONTENT="text/html; charset=iso-8859-1">
+ <TITLE></TITLE>
+ <META NAME="GENERATOR" CONTENT="StarOffice/5.2 (Linux)">
+ <META NAME="AUTHOR" CONTENT=" ">
+ <META NAME="CREATED" CONTENT="20020211;20201700">
+ <META NAME="CHANGEDBY" CONTENT=" ">
+ <META NAME="CHANGED" CONTENT="20020304;21123700">
+</HEAD>
+<BODY>
+<H3>YAFFS Progress 4 March 2002</H3>
+<H3><BR><BR>
+</H3>
+<H3>Design</H3>
+<P>A few of the design areas needed to be tweaked slightly without
+significant impact.</P>
+<P>The only real significance is that what is termed a yaffs_Inode
+really becomes an object Id. Where an 'object' is a file, directory,
+symlink or hard link. This differs from the *nix concept of an inode
+in that a hard link is not an inode. yaffs_Inode should really be
+renamed to yaffs_Object to reflect this.</P>
+<P>Rge reason for introducing the object is to provide identifiers
+for the objects stored on NAND. For example, each hardlink (which
+does not have a distinct inode) needs an object Id for storage on
+</P>
+<H3>Code</H3>
+<P>Pretty much all the guts of the code is there except for:</P>
+<UL>
+ <LI><P>symlink handling (a doddle)</P>
+ <LI><P>hard link handling.</P>
+ <LI><P>some of start-up scanning</P>
+ <LI><P>ECC on tags</P>
+ <LI><P>superblock handling (ie hook-up to mtd and the Linux VFS).
+ Some of this code to be pinched from JFFS2.</P>
+</UL>
+<P>Some of the code has already been tested.</P>
+<P>I will now be testing out the guts on a NAND emulation layer in an
+application. This provides better debugging. I hope to have this
+running by 11/03/2002.
+</P>
+<P>Once the guts looks solid on the NAND emulation, I will graft it
+on to the VFS and mtd - at which point it becomes a real file
+system.</P>
+<H3>Time</H3>
+<P>So far I've logged 90 hours on yaffs. I will not be charging for
+approx 15 hours I have spent swotting up on the Linux VFS. I still
+believe this is on budget.</P>
+<P><BR><BR>
+</P>
+<P><BR><BR>
+</P>
+<P><BR><BR>
+</P>
+</BODY>
+</HTML>
\ No newline at end of file
--- /dev/null
+#Makefile for YAFFS as a module
+#
+# NB this is not yet suitable for putting into the kernel tree.
+# YAFFS: Yet another FFS. A NAND-flash specific file system.
+#
+# Copyright (C) 2002 Aleph One Ltd.
+# for Toby Churchill Ltd and Brightstar Engineering
+#
+# Created by Charles Manning <charles@aleph1.co.uk>
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 as
+# published by the Free Software Foundation.
+
+## Change or override KERNELDIR to your kernel
+## comment out USE_xxxx if you don't want these features.
+
+KERNELDIR = /usr/src/kernel-headers-2.4.18
+USE_RAM_FOR_TEST = -DYAFFS_RAM_ENABLED
+USE_MTD = -DYAFFS_MTD_ENABLED
+
+
+CFLAGS = -D__KERNEL__ -DMODULE $(USE_RAM_FOR_TEST) $(USE_MTD) -I$(KERNELDIR)/include -O2 -Wall
+
+
+OBJS = yaffs_fs.o yaffs_guts.o yaffs_ramem.o yaffs_mtdif.o
+
+
+all: yaffs.o
+
+$(OBJS): %.o: %.c
+ gcc -c $(CFLAGS) $< -o $@
+
+yaffs.o: $(OBJS)
+ ld -r $(OBJS) -o $@
+
+clean:
+ rm -f $(OBJS) core
--- /dev/null
+/*
+ * YAFFS: Yet another FFS. A NAND-flash specific file system.
+ * devextras.h
+ *
+ * Copyright (C) 2002 Aleph One Ltd.
+ * for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This file is just holds extra declarations used during development.
+ * Most of these are from kernel includes placed here so we can use them in
+ * applications.
+ *
+ */
+
+#ifndef __EXTRAS_H__
+#define __EXTRAS_H__
+
+#ifndef __KERNEL__
+
+// User space defines
+
+typedef unsigned char __u8;
+typedef unsigned short __u16;
+typedef unsigned __u32;
+
+
+/*
+ * Simple doubly linked list implementation.
+ *
+ * Some of the internal functions ("__xxx") are useful when
+ * manipulating whole lists rather than single entries, as
+ * sometimes we already know the next/prev entries and we can
+ * generate better code by using them directly rather than
+ * using the generic single-entry routines.
+ */
+
+ #define prefetch(x) 1
+
+
+struct list_head {
+ struct list_head *next, *prev;
+};
+
+#define LIST_HEAD_INIT(name) { &(name), &(name) }
+
+#define LIST_HEAD(name) \
+ struct list_head name = LIST_HEAD_INIT(name)
+
+#define INIT_LIST_HEAD(ptr) do { \
+ (ptr)->next = (ptr); (ptr)->prev = (ptr); \
+} while (0)
+
+/*
+ * Insert a new entry between two known consecutive entries.
+ *
+ * This is only for internal list manipulation where we know
+ * the prev/next entries already!
+ */
+static __inline__ void __list_add(struct list_head * new,
+ struct list_head * prev,
+ struct list_head * next)
+{
+ next->prev = new;
+ new->next = next;
+ new->prev = prev;
+ prev->next = new;
+}
+
+/**
+ * list_add - add a new entry
+ * @new: new entry to be added
+ * @head: list head to add it after
+ *
+ * Insert a new entry after the specified head.
+ * This is good for implementing stacks.
+ */
+static __inline__ void list_add(struct list_head *new, struct list_head *head)
+{
+ __list_add(new, head, head->next);
+}
+
+/**
+ * list_add_tail - add a new entry
+ * @new: new entry to be added
+ * @head: list head to add it before
+ *
+ * Insert a new entry before the specified head.
+ * This is useful for implementing queues.
+ */
+static __inline__ void list_add_tail(struct list_head *new, struct list_head *head)
+{
+ __list_add(new, head->prev, head);
+}
+
+/*
+ * Delete a list entry by making the prev/next entries
+ * point to each other.
+ *
+ * This is only for internal list manipulation where we know
+ * the prev/next entries already!
+ */
+static __inline__ void __list_del(struct list_head * prev,
+ struct list_head * next)
+{
+ next->prev = prev;
+ prev->next = next;
+}
+
+/**
+ * list_del - deletes entry from list.
+ * @entry: the element to delete from the list.
+ * Note: list_empty on entry does not return true after this, the entry is in an undefined state.
+ */
+static __inline__ void list_del(struct list_head *entry)
+{
+ __list_del(entry->prev, entry->next);
+}
+
+/**
+ * list_del_init - deletes entry from list and reinitialize it.
+ * @entry: the element to delete from the list.
+ */
+static __inline__ void list_del_init(struct list_head *entry)
+{
+ __list_del(entry->prev, entry->next);
+ INIT_LIST_HEAD(entry);
+}
+
+/**
+ * list_empty - tests whether a list is empty
+ * @head: the list to test.
+ */
+static __inline__ int list_empty(struct list_head *head)
+{
+ return head->next == head;
+}
+
+/**
+ * list_splice - join two lists
+ * @list: the new list to add.
+ * @head: the place to add it in the first list.
+ */
+static __inline__ void list_splice(struct list_head *list, struct list_head *head)
+{
+ struct list_head *first = list->next;
+
+ if (first != list) {
+ struct list_head *last = list->prev;
+ struct list_head *at = head->next;
+
+ first->prev = head;
+ head->next = first;
+
+ last->next = at;
+ at->prev = last;
+ }
+}
+
+/**
+ * list_entry - get the struct for this entry
+ * @ptr: the &struct list_head pointer.
+ * @type: the type of the struct this is embedded in.
+ * @member: the name of the list_struct within the struct.
+ */
+#define list_entry(ptr, type, member) \
+ ((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member)))
+
+/**
+ * list_for_each - iterate over a list
+ * @pos: the &struct list_head to use as a loop counter.
+ * @head: the head for your list.
+ */
+#define list_for_each(pos, head) \
+ for (pos = (head)->next, prefetch(pos->next); pos != (head); \
+ pos = pos->next, prefetch(pos->next))
+
+/**
+ * list_for_each_safe - iterate over a list safe against removal of list entry
+ * @pos: the &struct list_head to use as a loop counter.
+ * @n: another &struct list_head to use as temporary storage
+ * @head: the head for your list.
+ */
+#define list_for_each_safe(pos, n, head) \
+ for (pos = (head)->next, n = pos->next; pos != (head); \
+ pos = n, n = pos->next)
+
+
+
+#define CURRENT_TIME 0
+
+
+/*
+ * File types
+ */
+#define DT_UNKNOWN 0
+#define DT_FIFO 1
+#define DT_CHR 2
+#define DT_DIR 4
+#define DT_BLK 6
+#define DT_REG 8
+#define DT_LNK 10
+#define DT_SOCK 12
+#define DT_WHT 14
+
+#include <sys/stat.h>
+
+/*
+ * Attribute flags. These should be or-ed together to figure out what
+ * has been changed!
+ */
+#define ATTR_MODE 1
+#define ATTR_UID 2
+#define ATTR_GID 4
+#define ATTR_SIZE 8
+#define ATTR_ATIME 16
+#define ATTR_MTIME 32
+#define ATTR_CTIME 64
+#define ATTR_ATIME_SET 128
+#define ATTR_MTIME_SET 256
+#define ATTR_FORCE 512 /* Not a change, but a change it */
+#define ATTR_ATTR_FLAG 1024
+
+
+struct iattr {
+ unsigned int ia_valid;
+ unsigned ia_mode;
+ unsigned ia_uid;
+ unsigned ia_gid;
+ unsigned ia_size;
+ unsigned ia_atime;
+ unsigned ia_mtime;
+ unsigned ia_ctime;
+ unsigned int ia_attr_flags;
+};
+
+#define KERN_DEBUG
+
+
+#else
+#include <linux/types.h>
+#include <linux/list.h>
+#include <linux/fs.h>
+#include <linux/stat.h>
+
+
+#endif
+
+
+
+
+#endif
+
--- /dev/null
+#########################################################
+# Makefile auto generated by Cygnus Source Navigator.
+# Target: yaffsdev_RAM Date: May 03 2002 Time: 07:11:35 PM
+#
+
+
+.SUFFIXES: .cc .class .java .cxx .C .cpp .o .c .l .y
+
+
+VPATH = /opt/aleph1/yaffs/.
+
+
+YACC = bison
+LEX = flex
+JAVA = gcj
+CC = gcc
+CPP = g++
+YACC_FLAGS =
+LEX_FLAGS =
+JAVA_FLAGS =
+CC_FLAGS = -g -Wall
+CPP_FLAGS =
+YACC_INCLUDES =
+LEX_INCLUDES =
+JAVA_INCLUDES =
+CC_INCLUDES =
+CPP_INCLUDES =
+YACC_DEFINES =
+LEX_DEFINES =
+JAVA_DEFINES =
+CC_DEFINES =
+CPP_DEFINES =
+yaffsdev_RAM_LIBS =
+LINKER = gcc
+LINKER_FLAGS =
+LINKER_ENTRY =
+yaffsdev_RAM_OBJECTS = yaffs_guts.o yaffs_ramem.o yaffsdev.o
+
+all: yaffsdev
+
+yaffsdev: $(yaffsdev_RAM_OBJECTS)
+ $(LINKER) -o yaffsdev $(LINKER_ENTRY) $(LINKER_FLAGS) $(yaffsdev_RAM_OBJECTS) $(yaffsdev_RAM_LIBS)
+
+.y.c:
+ $(YACC) $< $(YACC_FLAGS) $(YACC_DEFINES) $(YACC_INCLUDES)
+
+
+.l.c:
+ $(LEX) -t $< > $@ $(LEX_FLAGS) $(LEX_DEFINES) $(LEX_INCLUDES)
+
+
+.java.o:
+ $(JAVA) -c $< $(JAVA_FLAGS) $(JAVA_DEFINES) $(JAVA_INCLUDES)
+.class:
+ $(JAVA) -c $< $(JAVA_FLAGS) $(JAVA_DEFINES) $(JAVA_INCLUDES)
+
+
+.c.o:
+ $(CC) -c $< $(CC_FLAGS) $(CC_DEFINES) $(CC_INCLUDES)
+
+
+.cpp.o:
+ $(CPP) -c $< $(CPP_FLAGS) $(CPP_DEFINES) $(CPP_INCLUDES)
+.C.o:
+ $(CPP) -c $< $(CPP_FLAGS) $(CPP_DEFINES) $(CPP_INCLUDES)
+.cc.o:
+ $(CPP) -c $< $(CPP_FLAGS) $(CPP_DEFINES) $(CPP_INCLUDES)
+.cxx.o:
+ $(CPP) -c $< $(CPP_FLAGS) $(CPP_DEFINES) $(CPP_INCLUDES)
+
+
+yaffs_guts.o: /opt/aleph1/yaffs/yaffs_guts.h /opt/aleph1/yaffs/yaffsinterface.h /opt/aleph1/yaffs/yportenv.h
+yaffs_ramem.o: yaffs_nandemul.h /opt/aleph1/yaffs/devextras.h /opt/aleph1/yaffs/yaffs_guts.h /opt/aleph1/yaffs/yaffsinterface.h /opt/aleph1/yaffs/yportenv.h
+yaffsdev.o: yaffs_nandemul.h /usr/include/stdio.h /usr/include/stdlib.h /usr/include/string.h /opt/aleph1/yaffs/yaffs_guts.h /opt/aleph1/yaffs/yaffsinterface.h
+
+clean:
+ rm -f *.o
+ rm -f yaffsdev
+
--- /dev/null
+#Makefile for mkyaffs
+#
+# NB this is not yet suitable for putting into the kernel tree.
+# YAFFS: Yet another FFS. A NAND-flash specific file system.
+#
+# Copyright (C) 2002 Aleph One Ltd.
+# for Toby Churchill Ltd and Brightstar Engineering
+#
+# Created by Charles Manning <charles@aleph1.co.uk>
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 as
+# published by the Free Software Foundation.
+
+## Change or override KERNELDIR to your kernel
+
+KERNELDIR = /usr/src/kernel-headers-2.4.18
+
+CFLAGS = -I$(KERNELDIR)/include -O2 -Wall
+
+
+OBJS = mkyaffs.o
+
+
+all: mkyaffs
+
+$(OBJS): %.o: %.c
+ gcc -c $(CFLAGS) $< -o $@
+
+mkyaffs: $(OBJS)
+ gcc -o $@ $(OBJS)
+
+clean:
+ rm -f $(OBJS) core
--- /dev/null
+/*
+ * YAFFS: Yet another FFS. A NAND-flash specific file system.
+ * mkyaffs.c Format a chunk of NAND for YAFFS.
+ *
+ * Copyright (C) 2002 Aleph One Ltd.
+ * for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Acknowledgement:
+ * This file is crafted from nandtest.c by Miguel Freitas (miguel@cetuc.puc-rio.br)
+ * and Steven J. Hill (sjhill@cotw.com)
+ *
+ * Overview:
+ * Formatting a YAFFS device is very simple. Just erase all undamaged blocks.
+ * NB Don't erase blocks maked as damaged.
+ */
+
+#define _GNU_SOURCE
+#include <ctype.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <asm/types.h>
+#include <linux/config.h>
+#include <linux/mtd/mtd.h>
+
+
+// countBits is a quick way of counting the number of bits in a byte.
+// ie. countBits[n] holds the number of 1 bits in a byte with the value n.
+
+static const char countBits[256] =
+{
+0,1,1,2,1,2,2,3,1,2,2,3,2,3,3,4,
+1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,
+1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,
+2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,
+1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,
+2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,
+2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,
+3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,
+1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,
+2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,
+2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,
+3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,
+2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,
+3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,
+3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,
+4,5,5,6,5,6,6,7,5,6,6,7,6,7,7,8
+};
+
+/*
+ * Buffer arrays used for running tests
+ */
+
+unsigned char oobbuf[16];
+
+
+/*
+ * Main program
+ */
+int main(int argc, char **argv)
+{
+ unsigned long addr;
+ int bs, fd, i;
+ struct mtd_oob_buf oob = {0, 16, (unsigned char *) &oobbuf};
+ mtd_info_t meminfo;
+ erase_info_t erase;
+
+ /* Make sure a device was specified */
+ if(argc < 2) {
+ printf("usage: %s <mtdname>\n", argv[0]);
+ exit(1);
+ }
+
+ /* Open the device */
+ if((fd = open(argv[1], O_RDWR)) == -1) {
+ perror("open flash");
+ exit(1);
+ }
+
+ /* Fill in MTD device capability structure */
+ if(ioctl(fd, MEMGETINFO, &meminfo) != 0) {
+ perror("MEMGETINFO");
+ close(fd);
+ exit(1);
+ }
+
+ /* Make sure device page sizes are valid */
+ if( !(meminfo.oobsize == 16 && meminfo.oobblock == 512))
+ {
+ printf("Unknown flash (not normal NAND)\n");
+ close(fd);
+ exit(1);
+ }
+
+
+ for(addr = 0; addr < meminfo.size; addr += meminfo.erasesize)
+ {
+ /* Read the OOB data to determine if the block is valid.
+ * If the block is damaged, then byte 5 of the OOB data will
+ * have at least 2 zero bits.
+ */
+ oob.start = addr;
+ oob.length = 16;
+ oob.ptr = oobbuf;
+ if (ioctl(fd, MEMREADOOB, &oob) != 0)
+ {
+ perror("ioctl(MEMREADOOB)");
+ close(fd);
+ exit(1);
+ }
+
+ if(countBits[oobbuf[5]] < 7)
+ {
+ printf("Block at 0x08%lx is damaged and is not being formatted\n",addr);
+ }
+ else
+ {
+ /* Erase this block */
+ erase.start = addr;
+ erase.length = meminfo.erasesize;
+ printf("Erasing block at 0x08%lx\n",addr);
+ if(ioctl(fd, MEMERASE, &erase) != 0)
+ {
+ perror("\nMTD Erase failure\n");
+ close(fd);
+ exit(1);
+ }
+
+ }
+
+ }
+
+
+ /* All the tests succeeded */
+ printf("OK\n");
+ close(fd);
+ return 0;
+}
+
--- /dev/null
+/*
+ * YAFFS: Yet another FFS. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002 Aleph One Ltd.
+ * for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
--- /dev/null
+/*
+ * YAFFS: Yet another FFS. A NAND-flash specific file system.
+ * yaffs_fileem.c NAND emulation on top of files
+ *
+ * Copyright (C) 2002 Aleph One Ltd.
+ * for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+ //yaffs_fileem.c
+
+#include "yaffs_nandif.h"
+#include "yaffs_guts.h"
+#include "yaffsinterface.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <string.h>
+
+#define FILE_SIZE_IN_MEG 2
+
+#define BLOCK_SIZE (32 * 528)
+#define BLOCKS_PER_MEG ((1024*1024)/(32 * 512))
+#define FILE_SIZE_IN_BLOCKS (FILE_SIZE_IN_MEG * BLOCKS_PER_MEG)
+#define FILE_SIZE_IN_BYTES (FILE_SIZE_IN_BLOCKS * BLOCK_SIZE)
+
+
+static int h;
+static __u8 ffChunk[528];
+
+
+
+static void CheckInit(void)
+{
+ static int initialised = 0;
+
+ int length;
+
+
+ if(!initialised)
+ {
+ memset(ffChunk,0xFF,528);
+
+ h = open("yaffs-em-file" , O_RDWR | O_CREAT, S_IREAD | S_IWRITE);
+ if(h < 0)
+ {
+ perror("Fatal error opening yaffs emulation file");
+ exit(1);
+ }
+ initialised = 1;
+
+ length = lseek(h,0,SEEK_END);
+ if(length != FILE_SIZE_IN_BYTES)
+ {
+ // Create file contents
+ int i;
+
+ printf("Creating emulation file...\n");
+ for(i = 0; i < FILE_SIZE_IN_BLOCKS; i++)
+ {
+ yaffs_EraseBlockInNAND(i);
+ }
+ }
+ }
+}
+
+int yaffs_WriteChunkToNAND(int chunkInNAND,__u8 *data, yaffs_Spare *spare)
+{
+ int pos;
+
+ pos = chunkInNAND * 528;
+
+ CheckInit();
+
+
+ if(data)
+ {
+ lseek(h,pos,SEEK_SET);
+ write(h,data,512);
+ }
+
+ pos += 512;
+
+ if(spare)
+ {
+ lseek(h,pos,SEEK_SET);
+ write(h,spare,16);
+ }
+
+ return YAFFS_OK;
+}
+
+
+int yaffs_ReadChunkFromNAND(int chunkInNAND, __u8 *data, yaffs_Spare *spare)
+{
+ int pos;
+
+ pos = chunkInNAND * 528;
+
+
+ CheckInit();
+
+ if(data)
+ {
+ lseek(h,pos,SEEK_SET);
+ read(h,data,512);
+ }
+
+ pos += 512;
+
+ if(spare)
+ {
+ lseek(h,pos,SEEK_SET);
+ read(h,spare,16);
+ }
+
+ return YAFFS_OK;
+}
+
+
+int yaffs_EraseBlockInNAND(int blockInNAND)
+{
+ int i;
+
+ CheckInit();
+
+ printf("Erasing block %d\n",blockInNAND);
+
+ lseek(h,blockInNAND * BLOCK_SIZE,SEEK_SET);
+ for(i = 0; i < 32; i++)
+ {
+ write(h,ffChunk,528);
+ }
+ return YAFFS_OK;
+}
+
--- /dev/null
+/*
+ * YAFFS: Yet another FFS. A NAND-flash specific file system.
+ * yaffs_fs.c
+ *
+ * Copyright (C) 2002 Aleph One Ltd.
+ * for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This is the file system front-end to YAFFS that hooks it up to
+ * the VFS.
+ *
+ * Special notes:
+ * >> sb->u.generic_sbp points to the yaffs_Device associated with this superblock
+ * >> inode->u.generic_ip points to the associated yaffs_Object.
+ */
+
+
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/version.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/fs.h>
+#include <linux/proc_fs.h>
+#include <linux/pagemap.h>
+#include <linux/mtd/mtd.h>
+#include <linux/interrupt.h>
+#include <linux/string.h>
+#include <linux/locks.h>
+
+#include <asm/uaccess.h>
+
+#include "yaffs_guts.h"
+
+#ifdef YAFFS_RAM_ENABLED
+#include "yaffs_nandemul.h"
+// 2 MB of RAM for emulation
+#define YAFFS_RAM_EMULATION_SIZE 0x200000
+#endif // YAFFS_RAM_ENABLED
+
+#ifdef YAFFS_MTD_ENABLED
+#include <linux/mtd/mtd.h>
+#include "yaffs_mtdif.h"
+#endif //YAFFS_MTD_ENABLED
+
+#define T(x) printk x
+
+
+
+#define yaffs_InodeToObject(iptr) ((yaffs_Object *)((iptr)->u.generic_ip))
+#define yaffs_DentryToObject(dptr) yaffs_InodeToObject((dptr)->d_inode)
+#define yaffs_SuperToDevice(sb) ((yaffs_Device *)sb->u.generic_sbp)
+
+
+
+static ssize_t yaffs_file_read(struct file *f, char *buf, size_t n, loff_t *pos);
+static ssize_t yaffs_file_write(struct file *f, const char *buf, size_t n, loff_t *pos);
+
+static int yaffs_sync_object(struct file * file, struct dentry *dentry, int datasync);
+
+static int yaffs_readdir(struct file *f, void *dirent, filldir_t filldir);
+
+static int yaffs_create(struct inode *dir, struct dentry *dentry, int mode);
+static struct dentry * yaffs_lookup(struct inode *dir, struct dentry *dentry);
+static int yaffs_link(struct dentry *old_dentry, struct inode * dir, struct dentry * dentry);
+static int yaffs_unlink(struct inode * dir, struct dentry *dentry);
+static int yaffs_symlink(struct inode * dir, struct dentry *dentry, const char * symname);
+static int yaffs_mkdir(struct inode * dir, struct dentry * dentry, int mode);
+static int yaffs_mknod(struct inode *dir, struct dentry *dentry, int mode, int dev);
+static int yaffs_rename(struct inode * old_dir, struct dentry *old_dentry, struct inode * new_dir,struct dentry *new_dentry);
+static int yaffs_setattr(struct dentry *dentry, struct iattr *attr);
+
+static int yaffs_statfs(struct super_block *sb, struct statfs *buf);
+static void yaffs_read_inode (struct inode *inode);
+static struct super_block *yaffs_read_super(struct super_block * sb, void * data, int silent);
+static void yaffs_put_inode (struct inode *inode);
+
+//static int yaffs_readpage(struct file*,struct page *
+
+static struct address_space_operations yaffs_address_ops = {
+// readpage: yaffs_readpage,
+// prepare_write: yaffs_prepare_write,
+// commit_write: yaffs_commit_write
+};
+
+
+static struct file_operations yaffs_file_operations = {
+ read: yaffs_file_read,
+ write: yaffs_file_write,
+// mmap: generic_file_mmap,
+ fsync: yaffs_sync_object,
+};
+
+
+static struct inode_operations yaffs_file_inode_operations = {
+ setattr: yaffs_setattr,
+};
+
+
+
+static struct file_operations yaffs_dir_operations = {
+ read: generic_read_dir,
+ readdir: yaffs_readdir,
+ fsync: yaffs_sync_object,
+};
+
+static struct inode_operations yaffs_dir_inode_operations = {
+ create: yaffs_create,
+ lookup: yaffs_lookup,
+ link: yaffs_link,
+ unlink: yaffs_unlink,
+ symlink: yaffs_symlink,
+ mkdir: yaffs_mkdir,
+ rmdir: yaffs_unlink,
+ mknod: yaffs_mknod,
+ rename: yaffs_rename,
+ setattr: yaffs_setattr,
+};
+
+static struct super_operations yaffs_super_ops = {
+ statfs: yaffs_statfs,
+ read_inode: yaffs_read_inode,
+ put_inode: yaffs_put_inode,
+// read_inode:
+// remount_fs:
+// clear_inode:
+};
+
+
+struct inode *yaffs_get_inode(struct super_block *sb, int mode, int dev,yaffs_Object *obj);
+
+/*
+ * Lookup is used to find objects in the fs
+ */
+static struct dentry * yaffs_lookup(struct inode *dir, struct dentry *dentry)
+{
+ yaffs_Object *obj;
+ struct inode *inode;
+
+
+ T((KERN_DEBUG"yaffs_lookup for %d:%s\n",yaffs_InodeToObject(dir)->objectId,dentry->d_name.name));
+
+ obj = yaffs_FindObjectByName(yaffs_InodeToObject(dir),dentry->d_name.name);
+
+ if(obj)
+ {
+ T((KERN_DEBUG"yaffs_lookup found %d\n",obj->objectId));
+
+ inode = yaffs_get_inode(dir->i_sb, obj->st_mode,0,obj);
+
+ if(inode)
+ {
+ T((KERN_DEBUG"yaffs_loookup looks good\n"));
+ dget(dentry); // try to solve directory bug
+ d_add(dentry,inode);
+ return dentry;
+ }
+
+ }
+ else
+ {
+ T((KERN_DEBUG"yaffs_lookup not found\n"));
+
+ }
+ return NULL;
+
+}
+
+// For now put inode is just for debugging
+static void yaffs_put_inode(struct inode *inode)
+{
+ T(("yaffs_put_inode: ino %d, count %d\n",(int)inode->i_ino, atomic_read(&inode->i_count)));
+}
+
+#ifdef YAFFS_ADDRESS_OPS
+static int yaffs_readpage(struct file *file, struct page * page)
+{
+ T((KERN_DEBUG"yaffs_readpage\n"));
+
+ // TODO
+ return 0;
+}
+
+static int yaffs_prepare_write(struct file *file, struct page *page, unsigned offset, unsigned to)
+{
+ T((KERN_DEBUG"yaffs_prepare_write\n"));
+
+ //TODO
+ return 0;
+}
+
+static int yaffs_commit_write(struct file *file, struct page *page, unsigned offset, unsigned to)
+{
+
+ struct inode *inode = page->mapping->host;
+ loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
+
+ T((KERN_DEBUG"yaffs_commit_write\n"));
+
+ return 0;
+}
+
+#endif //YAFFS_ADDRESS_OPS
+
+
+static void yaffs_FillInodeFromObject(struct inode *inode, yaffs_Object *obj)
+{
+ if (inode && obj)
+ {
+ inode->i_ino = obj->objectId;
+ inode->i_mode = obj->st_mode;
+ inode->i_uid = obj->st_uid;
+ inode->i_gid = obj->st_gid;
+ inode->i_blksize = YAFFS_BYTES_PER_CHUNK;
+ inode->i_blocks = 0;
+ inode->i_rdev = NODEV;
+ inode->i_mapping->a_ops = &yaffs_address_ops;
+ inode->i_atime = obj->st_atime;
+ inode->i_mtime = obj->st_mtime;
+ inode->i_ctime = obj->st_ctime;
+ inode->i_size = yaffs_GetObjectFileLength(obj);
+ inode->i_nlink = yaffs_GetObjectLinkCount(obj);
+
+ T((KERN_DEBUG"yaffs_FillInode mode %x uid %d gid %d size %d count %d\n",
+ inode->i_mode, inode->i_uid, inode->i_gid, (int)inode->i_size, atomic_read(&inode->i_count)));
+
+ switch (obj->st_mode & S_IFMT)
+ {
+ default:
+ // init_special_inode(inode, mode, dev);
+ break;
+ case S_IFREG: // file
+ inode->i_op = &yaffs_file_inode_operations;
+ inode->i_fop = &yaffs_file_operations;
+ break;
+ case S_IFDIR: // directory
+ inode->i_op = &yaffs_dir_inode_operations;
+ inode->i_fop = &yaffs_dir_operations;
+ break;
+ case S_IFLNK: // symlink
+ inode->i_op = &page_symlink_inode_operations;
+ break;
+ }
+
+
+ inode->u.generic_ip = obj;
+
+ }
+ else
+ {
+ T((KERN_DEBUG"yaffs_FileInode invalid parameters\n"));
+ }
+
+}
+
+struct inode *yaffs_get_inode(struct super_block *sb, int mode, int dev,yaffs_Object *obj)
+{
+ struct inode * inode;
+
+ T((KERN_DEBUG"yaffs_get_inode for object %d\n",obj->objectId));
+
+ inode = iget(sb,obj->objectId);
+
+ // No need to call this since iget calls it via the read_inode callback
+ // yaffs_FillInodeFromObject(inode,obj);
+
+ return inode;
+}
+
+static ssize_t yaffs_file_read(struct file *f, char *buf, size_t n, loff_t *pos)
+{
+ yaffs_Object *obj;
+ int nRead,ipos;
+ struct inode *inode;
+
+ T((KERN_DEBUG"yaffs_file_read\n"));
+
+ obj = yaffs_DentryToObject(f->f_dentry);
+ inode = f->f_dentry->d_inode;
+
+ if (*pos < inode->i_size)
+ {
+ if (*pos + n > inode->i_size)
+ {
+ n = inode->i_size - *pos;
+ }
+ }
+ else
+ {
+ n = 0;
+ }
+
+ nRead = yaffs_ReadDataFromFile(obj,buf,*pos,n);
+ if(nRead > 0)
+ {
+ f->f_pos += nRead;
+ }
+ ipos = *pos;
+ T((KERN_DEBUG"yaffs_file_read read %d bytes, %d read at %d\n",n,nRead,ipos));
+ return nRead;
+
+}
+
+static ssize_t yaffs_file_write(struct file *f, const char *buf, size_t n, loff_t *pos)
+{
+ yaffs_Object *obj;
+ int nWritten,ipos;
+ struct inode *inode;
+
+ obj = yaffs_DentryToObject(f->f_dentry);
+ inode = f->f_dentry->d_inode;
+ nWritten = yaffs_WriteDataToFile(obj,buf,*pos,n);
+ ipos = *pos;
+ T((KERN_DEBUG"yaffs_file_write writing %d bytes, %d written at %d\n",n,nWritten,ipos));
+ if(nWritten > 0)
+ {
+ *pos += nWritten;
+ ipos = *pos;
+ if(*pos > inode->i_size)
+ {
+ inode->i_size = *pos;
+ T((KERN_DEBUG"yaffs_file_write size updated to %d\n",ipos));
+ }
+
+ }
+ return nWritten;
+}
+
+
+static int yaffs_readdir(struct file *f, void *dirent, filldir_t filldir)
+{
+ yaffs_Object *obj;
+ struct inode *inode = f->f_dentry->d_inode;
+ unsigned long offset, curoffs;
+ struct list_head *i;
+ yaffs_Object *l;
+
+ char name[YAFFS_MAX_NAME_LENGTH +1];
+
+ obj = yaffs_DentryToObject(f->f_dentry);
+
+ offset = f->f_pos;
+
+ T(("yaffs_readdir: starting at %d\n",(int)offset));
+
+ if(offset == 0)
+ {
+ T((KERN_DEBUG"yaffs_readdir: entry . ino %d \n",(int)inode->i_ino));
+ if(filldir(dirent,".",1,offset,inode->i_ino,DT_DIR) < 0)
+ {
+ goto out;
+ }
+ offset++;
+ f->f_pos++;
+ }
+ if(offset == 1)
+ {
+ T((KERN_DEBUG"yaffs_readdir: entry .. ino %d \n",(int)f->f_dentry->d_parent->d_inode->i_ino));
+ if(filldir(dirent,"..",2,offset,f->f_dentry->d_parent->d_inode->i_ino,DT_DIR) < 0)
+ {
+ goto out;
+ }
+ offset++;
+ f->f_pos++;
+ }
+
+ curoffs = 1;
+
+ //down(&obj->sem);
+
+
+ list_for_each(i,&obj->variant.directoryVariant.children)
+ {
+ curoffs++;
+ if(curoffs >= offset)
+ {
+ l = list_entry(i, yaffs_Object,siblings);
+
+ yaffs_GetObjectName(l,name,YAFFS_MAX_NAME_LENGTH+1);
+ T((KERN_DEBUG"yaffs_readdir: %s inode %d\n",name,yaffs_GetObjectInode(l)));
+
+ if(filldir(dirent,
+ name,
+ strlen(name),
+ offset,
+ yaffs_GetObjectInode(l),
+ yaffs_GetObjectType(l))
+ < 0)
+ {
+ goto up_and_out;
+ }
+
+ offset++;
+ f->f_pos++;
+ }
+ }
+
+ up_and_out:
+
+ //up(&obj->sem);
+
+ out:
+ return 0;
+}
+
+
+/*
+ * File creation. Allocate an inode, and we're done..
+ */
+static int yaffs_mknod(struct inode *dir, struct dentry *dentry, int mode, int dev)
+{
+ struct inode *inode;
+
+ yaffs_Object *obj = NULL;
+ yaffs_Object *parent = yaffs_InodeToObject(dir);
+
+ int error = -ENOSPC;
+
+ if(parent)
+ {
+ T((KERN_DEBUG"yaffs_mknod: parent object %d type %d\n",
+ parent->objectId,parent->variantType));
+ }
+ else
+ {
+ T((KERN_DEBUG"yaffs_mknod: could not get parent object\n"));
+ return -EPERM;
+ }
+
+ T(("yaffs_mknod: making oject for %s, mode %x\n",
+ dentry->d_name.name, mode));
+
+ switch (mode & S_IFMT)
+ {
+ default:
+
+ break;
+ case S_IFREG: // file
+ T((KERN_DEBUG"yaffs_mknod: making file\n"));
+ obj = yaffs_MknodFile(parent,dentry->d_name.name,mode,current->uid, current->gid);
+ break;
+ case S_IFDIR: // directory
+ T((KERN_DEBUG"yaffs_mknod: making directory\n"));
+ obj = yaffs_MknodDirectory(parent,dentry->d_name.name,mode,current->uid, current->gid);
+ break;
+ case S_IFLNK: // symlink
+ T((KERN_DEBUG"yaffs_mknod: making file\n"));
+ obj = NULL; // Todo
+ break;
+ }
+
+ if(obj)
+ {
+ inode = yaffs_get_inode(dir->i_sb, mode, dev, obj);
+
+// did not fix dir bug if((mode & S_IFMT) == S_IFDIR) atomic_inc(&inode->i_count);
+
+ d_instantiate(dentry, inode);
+ T((KERN_DEBUG"yaffs_mknod created object %d count = %d\n",obj->objectId,atomic_read(&inode->i_count)));
+ error = 0;
+ }
+ else
+ {
+ T((KERN_DEBUG"yaffs_mknod failed making object\n"));
+ error = -ENOMEM;
+ }
+
+
+ return error;
+}
+
+static int yaffs_mkdir(struct inode * dir, struct dentry * dentry, int mode)
+{
+ int retVal;
+ T((KERN_DEBUG"yaffs_mkdir\n"));
+ retVal = yaffs_mknod(dir, dentry, mode | S_IFDIR, 0);
+#if 0
+ // attempt to fix dir bug - didn't work
+ if(!retVal)
+ {
+ dget(dentry);
+ }
+#endif
+ return retVal;
+}
+
+static int yaffs_create(struct inode *dir, struct dentry *dentry, int mode)
+{
+ T((KERN_DEBUG"yaffs_create\n"));
+ return yaffs_mknod(dir, dentry, mode | S_IFREG, 0);
+}
+
+
+static int yaffs_unlink(struct inode * dir, struct dentry *dentry)
+{
+
+ T((KERN_DEBUG"yaffs_unlink\n"));
+
+ if(yaffs_Unlink(yaffs_InodeToObject(dir),dentry->d_name.name) == YAFFS_OK)
+ {
+ return 0;
+ }
+ else
+ {
+ return -ENOTEMPTY;
+ }
+}
+
+
+/*
+ * Link a file..
+ */
+static int yaffs_link(struct dentry *old_dentry, struct inode * dir, struct dentry * dentry)
+{
+ struct inode *inode = old_dentry->d_inode;
+
+ T((KERN_DEBUG"yaffs_link\n"));
+
+ return -EPERM; //Todo
+
+
+ if (S_ISDIR(inode->i_mode))
+ return -EPERM;
+
+
+ return 0;
+}
+
+
+static int yaffs_symlink(struct inode * dir, struct dentry *dentry, const char * symname)
+{
+ int error;
+
+ T((KERN_DEBUG"yaffs_symlink\n"));
+
+
+ return -ENOMEM; //Todo
+
+ error = yaffs_mknod(dir, dentry, S_IFLNK | S_IRWXUGO, 0);
+ return error;
+}
+
+static int yaffs_sync_object(struct file * file, struct dentry *dentry, int datasync)
+{
+
+ T((KERN_DEBUG"yaffs_sync_object\n"));
+ yaffs_FlushFile(yaffs_DentryToObject(dentry));
+ return 0;
+}
+
+/*
+ * The VFS layer already does all the dentry stuff for rename.
+ */
+static int yaffs_rename(struct inode * old_dir, struct dentry *old_dentry, struct inode * new_dir,struct dentry *new_dentry)
+{
+
+
+ if( yaffs_RenameObject(yaffs_InodeToObject(old_dir),old_dentry->d_name.name,
+ yaffs_InodeToObject(new_dir),new_dentry->d_name.name) == YAFFS_OK)
+ {
+ return 0;
+ }
+ else
+ {
+ return -ENOTEMPTY;
+ }
+
+
+}
+
+static int yaffs_setattr(struct dentry *dentry, struct iattr *attr)
+{
+ struct inode *inode = dentry->d_inode;
+ int error;
+
+ T((KERN_DEBUG"yaffs_setattr\n"));
+
+ if((error = inode_change_ok(inode,attr)) == 0)
+ {
+
+ if(yaffs_SetAttributes(yaffs_InodeToObject(inode),attr) == YAFFS_OK)
+ {
+ error = 0;
+ }
+ else
+ {
+ error = -EPERM;
+ }
+
+ inode_setattr(inode,attr);
+ }
+ return error;
+}
+
+static int yaffs_statfs(struct super_block *sb, struct statfs *buf)
+{
+ T((KERN_DEBUG"yaffs_statfs\n"));
+
+ buf->f_type = YAFFS_MAGIC;
+ buf->f_bsize = YAFFS_BYTES_PER_CHUNK;
+ buf->f_namelen = 255;
+ buf->f_blocks = yaffs_SuperToDevice(sb)->nBlocks * YAFFS_CHUNKS_PER_BLOCK;
+ buf->f_files = 0;
+ buf->f_ffree = 0;
+ buf->f_bavail = yaffs_GetNumberOfFreeChunks(yaffs_SuperToDevice(sb));
+ return 0;
+}
+
+static void yaffs_read_inode (struct inode *inode)
+{
+
+ yaffs_Object *obj ;
+
+ T((KERN_DEBUG"yaffs_read_inode for %d\n",(int)inode->i_ino));
+
+ obj = yaffs_FindObjectByNumber(yaffs_SuperToDevice(inode->i_sb),inode->i_ino);
+
+ yaffs_FillInodeFromObject(inode,obj);
+}
+
+
+static struct super_block *yaffs_internal_read_super(int useRam, struct super_block * sb, void * data, int silent)
+{
+ struct inode * inode;
+ struct dentry * root;
+ yaffs_Device *dev;
+
+
+ T(("yaffs_read_super:\n"));
+ sb->s_blocksize = YAFFS_BYTES_PER_CHUNK;
+ sb->s_blocksize_bits = YAFFS_CHUNK_SIZE_SHIFT;
+ sb->s_magic = YAFFS_MAGIC;
+ sb->s_op = &yaffs_super_ops;
+
+ if(!sb)
+ printk(KERN_INFO"sb is NULL\n");
+ else if(!sb->s_dev)
+ printk(KERN_INFO"sb->s_dev is NULL\n");
+ else if(! kdevname(sb->s_dev))
+ printk(KERN_INFO"kdevname is NULL\n");
+ else
+ printk(KERN_INFO"dev is %d name is \"%s\"\n", sb->s_dev, kdevname(sb->s_dev));
+
+
+ if(useRam)
+ {
+
+#if YAFFS_RAM_ENABLED
+ // Set the yaffs_Device up for ram emulation
+
+ sb->u.generic_sbp = dev = kmalloc(sizeof(yaffs_Device),GFP_KERNEL);
+ if(!dev)
+ {
+ // Deep shit could not allocate device structure
+ printk(KERN_DEBUG"yaffs_read_super: Failed trying to allocate yaffs_Device. Terminating debug.\n");
+ return NULL;
+ }
+
+ memset(dev,0,sizeof(yaffs_Device));
+ dev->genericDevice = NULL; // Not used for RAM emulation.
+
+ dev->nBlocks = YAFFS_RAM_EMULATION_SIZE / (YAFFS_CHUNKS_PER_BLOCK * YAFFS_BYTES_PER_CHUNK);
+ dev->startBlock = 1; // Don't use block 0
+ dev->endBlock = dev->nBlocks - 1;
+
+ dev->writeChunkToNAND = nandemul_WriteChunkToNAND;
+ dev->readChunkFromNAND = nandemul_ReadChunkFromNAND;
+ dev->eraseBlockInNAND = nandemul_EraseBlockInNAND;
+ dev->initialiseNAND = nandemul_InitialiseNAND;
+#endif
+
+ }
+ else
+ {
+#ifdef YAFFS_MTD_ENABLED
+ struct mtd_info *mtd;
+
+ // Hope it's a NAND mtd
+ mtd = get_mtd_device(NULL, MINOR(sb->s_dev));
+ if (!mtd)
+ {
+ printk(KERN_DEBUG "yaffs: MTD device #%u doesn't appear to exist\n", MINOR(sb->s_dev));
+ return NULL;
+ }
+ if(mtd->type != MTD_NANDFLASH)
+ {
+ printk(KERN_DEBUG "yaffs: MTD device is not NAND it's type %d\n", mtd->type);
+ return NULL;
+ }
+
+ if(!mtd->erase ||
+ !mtd->read ||
+ !mtd->write ||
+ !mtd->read_oob ||
+ !mtd->write_oob)
+ {
+ printk(KERN_DEBUG "yaffs: MTD device does not support required functions\n");
+ return NULL;
+ }
+
+ if(mtd->oobblock != YAFFS_BYTES_PER_CHUNK ||
+ mtd->oobsize != YAFFS_BYTES_PER_SPARE)
+ {
+ printk(KERN_DEBUG "yaffs: MTD device does not support have the right page sizes\n");
+ return NULL;
+ }
+
+
+ // OK, so if we got here, we have an MTD that's NAND and looks
+ // like it has the right capabilities
+ // Set the yaffs_Device up for ram emulation
+
+ sb->u.generic_sbp = dev = kmalloc(sizeof(yaffs_Device),GFP_KERNEL);
+ if(!dev)
+ {
+ // Deep shit could not allocate device structure
+ printk(KERN_DEBUG"yaffs_read_super: Failed trying to allocate yaffs_Device. Terminating debug.\n");
+ return NULL;
+ }
+
+ memset(dev,0,sizeof(yaffs_Device));
+ dev->genericDevice = mtd;
+
+ // Set up the memory size parameters....
+
+ dev->nBlocks = mtd->size / (YAFFS_CHUNKS_PER_BLOCK * YAFFS_BYTES_PER_CHUNK);
+ dev->startBlock = 1; // Don't use block 0
+ dev->endBlock = dev->nBlocks - 1;
+
+ // ... and the functions.
+ dev->writeChunkToNAND = nandmtd_WriteChunkToNAND;
+ dev->readChunkFromNAND = nandmtd_ReadChunkFromNAND;
+ dev->eraseBlockInNAND = nandmtd_EraseBlockInNAND;
+ dev->initialiseNAND = nandmtd_InitialiseNAND;
+
+#endif
+ }
+
+
+
+ yaffs_GutsInitialise(yaffs_SuperToDevice(sb));
+ T(("yaffs_read_super: guts initialised\n"));
+
+ // Create root inode
+ inode = yaffs_get_inode(sb, S_IFDIR | 0755, 0,yaffs_Root(yaffs_SuperToDevice(sb)));
+ if (!inode)
+ return NULL;
+
+ T(("yaffs_read_super: got root inode\n"));
+
+
+ root = d_alloc_root(inode);
+
+ T(("yaffs_read_super: d_alloc_root done\n"));
+
+ if (!root) {
+ iput(inode);
+ return NULL;
+ }
+ sb->s_root = root;
+
+ T(("yaffs_read_super: done\n"));
+ return sb;
+}
+
+#ifdef YAFFS_MTD_ENABLED
+static struct super_block *yaffs_read_super(struct super_block * sb, void * data, int silent)
+{
+ return yaffs_internal_read_super(0,sb,data,silent);
+}
+
+static DECLARE_FSTYPE(yaffs_fs_type, "yaffs", yaffs_read_super, FS_REQUIRES_DEV);
+#endif
+
+#ifdef YAFFS_RAM_ENABLED
+
+static struct super_block *yaffs_ram_read_super(struct super_block * sb, void * data, int silent)
+{
+ return yaffs_internal_read_super(1,sb,data,silent);
+}
+
+static DECLARE_FSTYPE(yaffs_ram_fs_type, "yaffsram", yaffs_ram_read_super, FS_SINGLE);
+#endif // YAFFS_RAM_ENABLED
+
+
+static struct proc_dir_entry *my_proc_entry;
+
+
+static int yaffs_proc_read(
+ char *page,
+ char **start,
+ off_t offset,
+ int count,
+ int *eof,
+ void *data
+ )
+{
+
+ static char my_buffer[1000];
+
+ if (offset > 0) return 0;
+
+ /* Fill the buffer and get its length */
+ sprintf( my_buffer,
+ "YAFFS built:"__DATE__ " "__TIME__"\n"
+
+ );
+
+ strcpy(page,my_buffer);
+ return strlen(my_buffer);
+}
+
+static int __init init_yaffs_fs(void)
+{
+ int error = 0;
+
+ printk(KERN_DEBUG "yaffs " __DATE__ " " __TIME__ " Initialisation\n");
+ /* Install the proc_fs entry */
+ my_proc_entry = create_proc_read_entry("yaffs",
+ S_IRUGO | S_IFREG,
+ &proc_root,
+ yaffs_proc_read,
+ NULL);
+ if(!my_proc_entry)
+ {
+ return -ENOMEM;
+ }
+
+#ifdef YAFFS_RAM_ENABLED
+
+ error = register_filesystem(&yaffs_ram_fs_type);
+ if(error)
+ {
+ return error;
+ }
+#endif //YAFFS_RAM_ENABLED
+
+#ifdef YAFFS_MTD_ENABLED
+ error = register_filesystem(&yaffs_fs_type);
+ if(error)
+ {
+#ifdef YAFFS_RAM_ENABLED
+ unregister_filesystem(&yaffs_ram_fs_type);
+#endif //YAFFS_RAM_ENABLED
+ }
+#endif // YAFFS_MTD_ENABLED
+
+ return error;
+}
+
+static void __exit exit_yaffs_fs(void)
+{
+ printk(KERN_DEBUG "yaffs " __DATE__ " " __TIME__ " Clean up\n");
+
+ remove_proc_entry("yaffs",&proc_root);
+
+#ifdef YAFFS_RAM_ENABLED
+ unregister_filesystem(&yaffs_ram_fs_type);
+#endif
+#ifdef YAFFS_MTD_ENABLED
+ unregister_filesystem(&yaffs_fs_type);
+#endif
+
+}
+
+module_init(init_yaffs_fs)
+module_exit(exit_yaffs_fs)
+
+MODULE_DESCRIPTION("YAFFS - a NAND specific flash file system");
+MODULE_AUTHOR("Charles Manning, Aleph One Ltd., 2002");
+MODULE_LICENSE("GPL");
+
--- /dev/null
+/*
+ * YAFFS: Yet another FFS. A NAND-flash specific file system.
+ * yaffs_guts.c The main guts of YAFFS
+ *
+ * Copyright (C) 2002 Aleph One Ltd.
+ * for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+ //yaffs_guts.c
+
+#include "yportenv.h"
+
+#include "yaffsinterface.h"
+#include "yaffs_guts.h"
+
+
+#if 0
+#define T(x) printf x
+#else
+#define T(x)
+#endif
+
+
+// countBits is a quick way of counting the number of bits in a byte.
+// ie. countBits[n] holds the number of 1 bits in a byte with the value n.
+
+static const char yaffs_countBits[256] =
+{
+0,1,1,2,1,2,2,3,1,2,2,3,2,3,3,4,
+1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,
+1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,
+2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,
+1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,
+2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,
+2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,
+3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,
+1,2,2,3,2,3,3,4,2,3,3,4,3,4,4,5,
+2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,
+2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,
+3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,
+2,3,3,4,3,4,4,5,3,4,4,5,4,5,5,6,
+3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,
+3,4,4,5,4,5,5,6,4,5,5,6,5,6,6,7,
+4,5,5,6,5,6,6,7,5,6,6,7,6,7,7,8
+};
+
+
+
+// Device info
+//static yaffs_Device *yaffs_device;
+//yaffs_Object *yaffs_rootDir;
+//yaffs_Object *yaffs_lostNFound;
+
+
+
+// Local prototypes
+static int yaffs_CheckObjectHashSanity(yaffs_Device *dev);
+static void yaffs_LoadTagsIntoSpare(yaffs_Spare *sparePtr, yaffs_Tags *tagsPtr);
+static void yaffs_GetTagsFromSpare(yaffs_Spare *sparePtr,yaffs_Tags *tagsPtr);
+static int yaffs_PutChunkIntoFile(yaffs_Object *in,int chunkInInode, int chunkInNAND);
+
+static yaffs_Object *yaffs_CreateNewObject(yaffs_Device *dev,int number,yaffs_ObjectType type);
+static void yaffs_AddObjectToDirectory(yaffs_Object *directory, yaffs_Object *obj);
+static int yaffs_UpdateObjectHeader(yaffs_Object *in,const char *name);
+static void yaffs_DeleteChunk(yaffs_Device *dev,int chunkId);
+static void yaffs_RemoveObjectFromDirectory(yaffs_Object *obj);
+static int yaffs_CheckStructures(void);
+static yaffs_Object *yaffs_GetEquivalentObject(yaffs_Object *obj);
+
+loff_t yaffs_GetFileSize(yaffs_Object *obj);
+
+
+static int yaffs_AllocateChunk(yaffs_Device *dev,int useReserve);
+
+#if YAFFS_PARANOID
+static int yaffs_CheckFileSanity(yaffs_Object *in)
+#else
+#define yaffs_CheckFileSanity(in)
+#endif
+
+static int __inline__ yaffs_HashFunction(int n)
+{
+ return (n % YAFFS_NOBJECT_BUCKETS);
+}
+
+
+yaffs_Object *yaffs_Root(yaffs_Device *dev)
+{
+ return dev->rootDir;
+}
+
+yaffs_Object *yaffs_LostNFound(yaffs_Device *dev)
+{
+ return dev->lostNFoundDir;
+}
+
+
+static int yaffs_WriteChunkToNAND(struct yaffs_DeviceStruct *dev,int chunkInNAND, const __u8 *data, yaffs_Spare *spare)
+{
+ return dev->writeChunkToNAND(dev,chunkInNAND,data,spare);
+}
+
+int yaffs_ReadChunkFromNAND(struct yaffs_DeviceStruct *dev,int chunkInNAND, __u8 *data, yaffs_Spare *spare)
+{
+ return dev->readChunkFromNAND(dev,chunkInNAND,data,spare);
+}
+
+int yaffs_EraseBlockInNAND(struct yaffs_DeviceStruct *dev,int blockInNAND)
+{
+ return dev->eraseBlockInNAND(dev,blockInNAND);
+}
+
+int yaffs_InitialiseNAND(struct yaffs_DeviceStruct *dev)
+{
+ return dev->initialiseNAND(dev);
+}
+
+static int yaffs_WriteNewChunkToNAND(struct yaffs_DeviceStruct *dev, const __u8 *data, yaffs_Spare *spare,int useReserve)
+{
+ int chunk;
+
+ int writeOk = 0;
+
+ do{
+ chunk = yaffs_AllocateChunk(dev,useReserve);
+
+ if(chunk >= 0)
+ {
+ writeOk = yaffs_WriteChunkToNAND(dev,chunk,data,spare);
+ if(writeOk)
+ {
+ //Todo read-back and verify
+ // If verify fails, then delete this chunk and try again
+ }
+ }
+ } while(chunk >= 0 && ! writeOk);
+
+ return chunk;
+}
+
+
+
+
+///////////////////////// Object management //////////////////
+// List of spare objects
+// The list is hooked together using the first pointer
+// in the object
+
+// static yaffs_Object *yaffs_freeObjects = NULL;
+
+// static int yaffs_nFreeObjects;
+
+// static yaffs_ObjectList *yaffs_allocatedObjectList = NULL;
+
+// static yaffs_ObjectBucket yaffs_objectBucket[YAFFS_NOBJECT_BUCKETS];
+
+
+static __u16 yaffs_CalcNameSum(const char *name)
+{
+ __u16 sum = 0;
+ __u16 i = 1;
+
+ __u8 *bname = (__u8 *)name;
+
+ while (*bname)
+ {
+ sum += (*bname) * i;
+ i++;
+ bname++;
+ }
+ return sum;
+}
+
+
+void yaffs_CalcECC(const __u8 *buffer, yaffs_Spare *spare)
+{
+
+ // Todo do nothing now. Need to put in ecc
+ spare->ecc1[0] = spare->ecc1[1] = spare->ecc1[2] = 0xFF;
+ spare->ecc2[0] = spare->ecc2[1] = spare->ecc2[2] = 0xFF;
+}
+
+void yaffs_CalcTagsECC(yaffs_Tags *tags)
+{
+ // Todo don't do anything yet. Need to calculate ecc
+ tags->ecc = 0xFFFFFFFF;
+}
+
+
+
+///////////////////////// TNODES ///////////////////////
+
+// List of spare tnodes
+// The list is hooked together using the first pointer
+// in the tnode.
+
+//static yaffs_Tnode *yaffs_freeTnodes = NULL;
+
+// static int yaffs_nFreeTnodes;
+
+//static yaffs_TnodeList *yaffs_allocatedTnodeList = NULL;
+
+
+
+// yaffs_CreateTnodes creates a bunch more tnodes and
+// adds them to the tnode free list.
+// Don't use this function directly
+
+static int yaffs_CreateTnodes(yaffs_Device *dev,int nTnodes)
+{
+ int i;
+ yaffs_Tnode *newTnodes;
+ yaffs_TnodeList *tnl;
+
+ if(nTnodes < 1) return YAFFS_OK;
+
+ // make these things
+
+ newTnodes = YMALLOC(nTnodes * sizeof(yaffs_Tnode));
+
+ if (!newTnodes)
+ {
+ YALERT("Could not malloc tnodes");
+ return YAFFS_FAIL;
+ }
+
+ // Hook them into the free list
+ for(i = 0; i < nTnodes - 1; i++)
+ {
+ newTnodes[i].internal[0] = &newTnodes[i+1];
+ }
+
+ newTnodes[nTnodes - 1].internal[0] = dev->freeTnodes;
+ dev->freeTnodes = newTnodes;
+ dev->nFreeTnodes+= nTnodes;
+ dev->nTnodesCreated += nTnodes;
+
+ // Now add this bunch of tnodes to a list for freeing up.
+
+ tnl = YMALLOC(sizeof(yaffs_TnodeList));
+ if(!tnl)
+ {
+ YALERT("Could not add tnodes to management list");
+ }
+ else
+ {
+ tnl->tnodes = newTnodes;
+ tnl->next = dev->allocatedTnodeList;
+ dev->allocatedTnodeList = tnl;
+ }
+
+
+ YINFO("Tnodes created");
+
+
+ return YAFFS_OK;
+}
+
+
+// GetTnode gets us a clean tnode. Tries to make allocate more if we run out
+static yaffs_Tnode *yaffs_GetTnode(yaffs_Device *dev)
+{
+ yaffs_Tnode *tn = NULL;
+
+ // If there are none left make more
+ if(!dev->freeTnodes)
+ {
+ yaffs_CreateTnodes(dev,YAFFS_ALLOCATION_NTNODES);
+ }
+
+ if(dev->freeTnodes)
+ {
+ tn = dev->freeTnodes;
+ dev->freeTnodes = dev->freeTnodes->internal[0];
+ dev->nFreeTnodes--;
+ // zero out
+ memset(tn,0,sizeof(yaffs_Tnode));
+ }
+
+
+ return tn;
+}
+
+
+// FreeTnode frees up a tnode and puts it back on the free list
+static void yaffs_FreeTnode(yaffs_Device*dev, yaffs_Tnode *tn)
+{
+ tn->internal[0] = dev->freeTnodes;
+ dev->freeTnodes = tn;
+ dev->nFreeTnodes++;
+}
+
+
+static void yaffs_DeinitialiseTnodes(yaffs_Device*dev)
+{
+ // Free the list of allocated tnodes
+
+ while(dev->allocatedTnodeList)
+ {
+ YFREE(dev->allocatedTnodeList->tnodes);
+ dev->allocatedTnodeList = dev->allocatedTnodeList->next;
+ }
+
+ dev->freeTnodes = NULL;
+ dev->nFreeTnodes = 0;
+}
+
+static void yaffs_InitialiseTnodes(yaffs_Device*dev)
+{
+ dev->allocatedTnodeList = NULL;
+ dev->freeTnodes = NULL;
+ dev->nFreeTnodes = 0;
+ dev->nTnodesCreated = 0;
+
+}
+
+void yaffs_TnodeTest(yaffs_Device *dev)
+{
+
+ int i;
+ int j;
+ yaffs_Tnode *tn[1000];
+
+ YINFO("Testing TNodes");
+
+ for(j = 0; j < 50; j++)
+ {
+ for(i = 0; i < 1000; i++)
+ {
+ tn[i] = yaffs_GetTnode(dev);
+ if(!tn[i])
+ {
+ YALERT("Getting tnode failed");
+ }
+ }
+ for(i = 0; i < 1000; i+=3)
+ {
+ yaffs_FreeTnode(dev,tn[i]);
+ tn[i] = NULL;
+ }
+
+ }
+}
+
+////////////////// END OF TNODE MANIPULATION ///////////////////////////
+
+/////////////// Functions to manipulate the look-up tree (made up of tnodes)
+// The look up tree is represented by the top tnode and the number of topLevel
+// in the tree. 0 means only the level 0 tnode is in the tree.
+
+
+// FindLevel0Tnode finds the level 0 tnode, if one exists.
+// Used when reading.....
+static yaffs_Tnode *yaffs_FindLevel0Tnode(yaffs_Device *dev,yaffs_FileStructure *fStruct, __u32 chunkId)
+{
+
+ yaffs_Tnode *tn = fStruct->top;
+ __u32 i;
+ int requiredTallness;
+ int level = fStruct->topLevel;
+
+ // Check sane level and chunk Id
+ if(level < 0 || level > YAFFS_TNODES_MAX_LEVEL)
+ {
+ char str[50];
+ sprintf(str,"Bad level %d",level);
+ YALERT(str);
+ return NULL;
+ }
+ if(chunkId > YAFFS_MAX_CHUNK_ID)
+ {
+ char str[50];
+ sprintf(str,"Bad chunkId %d",chunkId);
+ YALERT(str);
+ return NULL;
+ }
+
+ // First check we're tall enough (ie enough topLevel)
+
+ i = chunkId >> (dev->chunkGroupBits + YAFFS_TNODES_LEVEL0_BITS);
+ requiredTallness = 0;
+ while(i)
+ {
+ i >>= YAFFS_TNODES_INTERNAL_BITS;
+ requiredTallness++;
+ }
+
+
+ if(requiredTallness > fStruct->topLevel)
+ {
+ // Not tall enough, so we can't find it, return NULL.
+ return NULL;
+ }
+
+
+ // Traverse down to level 0
+ while (level > 0 && tn)
+ {
+ tn = tn->internal[(chunkId >>(dev->chunkGroupBits + YAFFS_TNODES_LEVEL0_BITS + (level-1) * YAFFS_TNODES_INTERNAL_BITS)) &
+ YAFFS_TNODES_INTERNAL_MASK];
+ level--;
+
+ }
+
+ return tn;
+}
+
+// AddOrFindLevel0Tnode finds the level 0 tnode if it exists, otherwise first expands the tree.
+// This happens in two steps:
+// 1. If the tree isn't tall enough, then make it taller.
+// 2. Scan down the tree towards the level 0 tnode adding tnodes if required.
+//
+// Used when modifying the tree.
+//
+static yaffs_Tnode *yaffs_AddOrFindLevel0Tnode(yaffs_Device *dev, yaffs_FileStructure *fStruct, __u32 chunkId)
+{
+
+ yaffs_Tnode *tn;
+
+ int requiredTallness;
+
+ __u32 i;
+ __u32 l;
+
+
+ T(("AddOrFind topLevel=%d, chunk=%d",fStruct->topLevel,chunkId));
+
+ // Check sane level and page Id
+ if(fStruct->topLevel < 0 || fStruct->topLevel > YAFFS_TNODES_MAX_LEVEL)
+ {
+ char str[50];
+ sprintf(str,"Bad level %d",fStruct->topLevel);
+ YALERT(str);
+ return NULL;
+ }
+
+ if(chunkId > YAFFS_MAX_CHUNK_ID)
+ {
+ char str[50];
+ sprintf(str,"Bad chunkId %d",chunkId);
+ YALERT(str);
+ return NULL;
+ }
+
+ // First check we're tall enough (ie enough topLevel)
+
+ i = chunkId >> (dev->chunkGroupBits + YAFFS_TNODES_LEVEL0_BITS);
+ requiredTallness = 0;
+ while(i)
+ {
+ i >>= YAFFS_TNODES_INTERNAL_BITS;
+ requiredTallness++;
+ }
+
+ T((" required=%d",requiredTallness));
+
+
+ if(requiredTallness > fStruct->topLevel)
+ {
+ // Not tall enough,gotta make the tree taller
+ for(i = fStruct->topLevel; i < requiredTallness; i++)
+ {
+ T((" add new top"));
+
+ tn = yaffs_GetTnode(dev);
+
+ if(tn)
+ {
+ tn->internal[0] = fStruct->top;
+ fStruct->top = tn;
+ }
+ else
+ {
+ YALERT("No more tnodes");
+ }
+ }
+
+ fStruct->topLevel = requiredTallness;
+ }
+
+
+ // Traverse down to level 0, adding anything we need
+
+ l = fStruct->topLevel;
+ tn = fStruct->top;
+ while (l > 0 && tn)
+ {
+ i = (chunkId >> (dev->chunkGroupBits +YAFFS_TNODES_LEVEL0_BITS + (l-1) * YAFFS_TNODES_INTERNAL_BITS)) &
+ YAFFS_TNODES_INTERNAL_MASK;
+
+ T((" [%d:%d]",l,i));
+
+ if(!tn->internal[i])
+ {
+ T((" added"));
+
+ tn->internal[i] = yaffs_GetTnode(dev);
+ }
+
+ tn = tn->internal[i];
+ l--;
+
+ }
+
+ T(("\n"));
+
+ return tn;
+}
+
+
+// Pruning removes any part of the file structure tree that is beyond the
+// bounds of the file.
+// A file should only get pruned when its size is reduced.
+//
+// Before pruning, the chunks must be pulled from the tree and the
+// level 0 tnode entries must be zeroed out.
+// Could also use this for file deletion, but that's probably better handled
+// by a special case.
+
+// yaffs_PruneWorker should only be called by yaffs_PruneFileStructure()
+
+static yaffs_Tnode *yaffs_PruneWorker(yaffs_Device *dev, yaffs_Tnode *tn, __u32 level, int del0)
+{
+ int i;
+ int hasData;
+
+ if(tn)
+ {
+ hasData = 0;
+
+ for(i = 0; i < YAFFS_NTNODES_INTERNAL; i++)
+ {
+ if(tn->internal[i] && level > 0)
+ {
+ tn->internal[i] = yaffs_PruneWorker(dev,tn->internal[i],level - 1, ( i == 0) ? del0 : 1);
+ }
+
+ if(tn->internal[i])
+ {
+ hasData++;
+ }
+ }
+
+ if(hasData == 0 && del0)
+ {
+ // Free and return NULL
+
+ yaffs_FreeTnode(dev,tn);
+ tn = NULL;
+ }
+
+ }
+
+ return tn;
+
+}
+
+static int yaffs_PruneFileStructure(yaffs_Device *dev, yaffs_FileStructure *fStruct)
+{
+ int i;
+ int hasData;
+ int done = 0;
+ yaffs_Tnode *tn;
+
+ if(fStruct->topLevel > 0)
+ {
+ fStruct->top = yaffs_PruneWorker(dev,fStruct->top, fStruct->topLevel,0);
+
+ // Now we have a tree with all the non-zero branches NULL but the height
+ // is the same as it was.
+ // Let's see if we can trim internal tnodes to shorten the tree.
+ // We can do this if only the 0th element in the tnode is in use
+ // (ie all the non-zero are NULL)
+
+ while(fStruct->topLevel && !done)
+ {
+ tn = fStruct->top;
+
+ hasData = 0;
+ for(i = 1; i <YAFFS_NTNODES_INTERNAL; i++)
+ {
+ if(tn->internal[i])
+ {
+ hasData++;
+ }
+ }
+
+ if(!hasData)
+ {
+ fStruct->top = tn->internal[0];
+ fStruct->topLevel--;
+ yaffs_FreeTnode(dev,tn);
+ }
+ else
+ {
+ done = 1;
+ }
+ }
+ }
+
+ return YAFFS_OK;
+}
+
+
+
+
+/////////////////////// End of File Structure functions. /////////////////
+
+// yaffs_CreateFreeObjects creates a bunch more objects and
+// adds them to the object free list.
+static int yaffs_CreateFreeObjects(yaffs_Device *dev, int nObjects)
+{
+ int i;
+ yaffs_Object *newObjects;
+ yaffs_ObjectList *list;
+
+ if(nObjects < 1) return YAFFS_OK;
+
+ // make these things
+
+ newObjects = YMALLOC(nObjects * sizeof(yaffs_Object));
+
+ if (!newObjects)
+ {
+ YALERT("Could not allocate more objects");
+ return YAFFS_FAIL;
+ }
+
+ // Hook them into the free list
+ for(i = 0; i < nObjects - 1; i++)
+ {
+ (yaffs_Object *)newObjects[i].siblings.next = &newObjects[i+1];
+ }
+
+ newObjects[nObjects - 1].siblings.next = (void *)dev->freeObjects;
+ dev->freeObjects = newObjects;
+ dev->nFreeObjects+= nObjects;
+ dev->nObjectsCreated+= nObjects;
+
+ // Now add this bunch of Objects to a list for freeing up.
+
+ list = YMALLOC(sizeof(yaffs_ObjectList));
+ if(!list)
+ {
+ YALERT("Could not add Objects to management list");
+ }
+ else
+ {
+ list->objects = newObjects;
+ list->next = dev->allocatedObjectList;
+ dev->allocatedObjectList = list;
+ }
+
+
+ YINFO("Objects created");
+
+
+ return YAFFS_OK;
+}
+
+
+// AllocateEmptyObject gets us a clean Object. Tries to make allocate more if we run out
+static yaffs_Object *yaffs_AllocateEmptyObject(yaffs_Device *dev)
+{
+ yaffs_Object *tn = NULL;
+
+ // If there are none left make more
+ if(!dev->freeObjects)
+ {
+ yaffs_CreateFreeObjects(dev,YAFFS_ALLOCATION_NOBJECTS);
+ }
+
+ if(dev->freeObjects)
+ {
+ tn = dev->freeObjects;
+ dev->freeObjects = (yaffs_Object *)(dev->freeObjects->siblings.next);
+ dev->nFreeObjects--;
+
+ // Now sweeten it up...
+
+ memset(tn,0,sizeof(yaffs_Object));
+ tn->chunkId = -1;
+ tn->variantType = YAFFS_OBJECT_TYPE_UNKNOWN;
+ INIT_LIST_HEAD(&(tn->hardLinks));
+ INIT_LIST_HEAD(&(tn->hashLink));
+ INIT_LIST_HEAD(&tn->siblings);
+
+ // Add it to the lost and found directory.
+ // NB Can't put root or lostNFound in lostNFound so
+ // check if lostNFound exists first
+ if(dev->lostNFoundDir)
+ {
+ yaffs_AddObjectToDirectory(dev->lostNFoundDir,tn);
+ }
+ }
+
+
+ return tn;
+}
+
+static yaffs_Object *yaffs_CreateFakeDirectory(yaffs_Device *dev,int number,__u32 mode)
+{
+
+ yaffs_Object *obj = yaffs_CreateNewObject(dev,number,YAFFS_OBJECT_TYPE_DIRECTORY);
+ if(obj)
+ {
+ obj->fake = 1; // it is fake so it has no NAND presence...
+ obj->renameAllowed= 0; // ... and we're not allowed to rename it...
+ obj->unlinkAllowed= 0; // ... or unlink it
+ obj->st_mode = mode;
+ obj->myDev = dev;
+ obj->chunkId = 0; // Not a valid chunk.
+ }
+
+ return obj;
+
+}
+
+
+static void yaffs_UnhashObject(yaffs_Object *tn)
+{
+ int bucket;
+ yaffs_Device *dev = tn->myDev;
+
+
+ // If it is still linked into the bucket list, free from the list
+ if(!list_empty(&tn->hashLink))
+ {
+ list_del_init(&tn->hashLink);
+ bucket = yaffs_HashFunction(tn->objectId);
+ dev->objectBucket[bucket].count--;
+ }
+
+}
+
+
+// FreeObject frees up a Object and puts it back on the free list
+static void yaffs_FreeObject(yaffs_Object *tn)
+{
+
+ yaffs_Device *dev = tn->myDev;
+
+ yaffs_UnhashObject(tn);
+
+ // Link into the free list.
+ (yaffs_Object *)(tn->siblings.next) = dev->freeObjects;
+ dev->freeObjects = tn;
+ dev->nFreeObjects++;
+}
+
+
+
+
+static void yaffs_DeinitialiseObjects(yaffs_Device *dev)
+{
+ // Free the list of allocated Objects
+
+ while( dev->allocatedObjectList)
+ {
+ YFREE(dev->allocatedObjectList->objects);
+ dev->allocatedObjectList = dev->allocatedObjectList->next;
+ }
+
+ dev->freeObjects = NULL;
+ dev->nFreeObjects = 0;
+}
+
+static void yaffs_InitialiseObjects(yaffs_Device *dev)
+{
+ int i;
+
+ dev->allocatedObjectList = NULL;
+ dev->freeObjects = NULL;
+ dev->nFreeObjects = 0;
+
+ for(i = 0; i < YAFFS_NOBJECT_BUCKETS; i++)
+ {
+ INIT_LIST_HEAD(&dev->objectBucket[i].list);
+ dev->objectBucket[i].count = 0;
+ }
+
+}
+
+
+
+
+
+
+int yaffs_FindNiceObjectBucket(yaffs_Device *dev)
+{
+ static int x = 0;
+ int i;
+ int l = 999;
+ int lowest = 999999;
+
+
+ // First let's see if we can find one that's empty.
+
+ for(i = 0; i < 10 && lowest > 0; i++)
+ {
+ x++;
+ x %= YAFFS_NOBJECT_BUCKETS;
+ if(dev->objectBucket[x].count < lowest)
+ {
+ lowest = dev->objectBucket[x].count;
+ l = x;
+ }
+
+ }
+
+ // If we didn't find an empty list, then try
+ // looking a bit further for a short one
+
+ for(i = 0; i < 10 && lowest > 3; i++)
+ {
+ x++;
+ x %= YAFFS_NOBJECT_BUCKETS;
+ if(dev->objectBucket[x].count < lowest)
+ {
+ lowest = dev->objectBucket[x].count;
+ l = x;
+ }
+
+ }
+
+ return l;
+}
+
+static int yaffs_CreateNewObjectNumber(yaffs_Device *dev)
+{
+ int bucket = yaffs_FindNiceObjectBucket(dev);
+
+ // Now find an object value that has not already been taken
+ // by scanning the list.
+
+ int found = 0;
+ struct list_head *i;
+
+ int n = bucket;
+
+ //yaffs_CheckObjectHashSanity();
+
+ while(!found)
+ {
+ found = 1;
+ n += YAFFS_NOBJECT_BUCKETS;
+ if(1 ||dev->objectBucket[bucket].count > 0)
+ {
+ list_for_each(i,&dev->objectBucket[bucket].list)
+ {
+ // If there is already one in the list
+ if(list_entry(i, yaffs_Object,hashLink)->objectId == n)
+ {
+ found = 0;
+ }
+ }
+ }
+ }
+
+ //T(("bucket %d count %d inode %d\n",bucket,yaffs_objectBucket[bucket].count,n);
+
+ return n;
+}
+
+void yaffs_HashObject(yaffs_Object *in)
+{
+ int bucket = yaffs_HashFunction(in->objectId);
+ yaffs_Device *dev = in->myDev;
+
+ if(!list_empty(&in->hashLink))
+ {
+ YINFO("!!!");
+ }
+
+
+ list_add(&in->hashLink,&dev->objectBucket[bucket].list);
+ dev->objectBucket[bucket].count++;
+
+}
+
+yaffs_Object *yaffs_FindObjectByNumber(yaffs_Device *dev,int number)
+{
+ int bucket = yaffs_HashFunction(number);
+ struct list_head *i;
+ yaffs_Object *in;
+
+ list_for_each(i,&dev->objectBucket[bucket].list)
+ {
+ // Lookm if it is in the list
+ in = list_entry(i, yaffs_Object,hashLink);
+ if(in->objectId == number)
+ {
+ return in;
+ }
+ }
+
+ return NULL;
+}
+
+
+
+yaffs_Object *yaffs_CreateNewObject(yaffs_Device *dev,int number,yaffs_ObjectType type)
+{
+
+ yaffs_Object *theObject;
+
+ if(number < 0)
+ {
+ number = yaffs_CreateNewObjectNumber(dev);
+ }
+
+ theObject = yaffs_AllocateEmptyObject(dev);
+
+ if(theObject)
+ {
+ theObject->fake = 0;
+ theObject->renameAllowed = 1;
+ theObject->unlinkAllowed = 1;
+ theObject->objectId = number;
+ theObject->myDev = dev;
+ yaffs_HashObject(theObject);
+ theObject->variantType = type;
+ theObject->st_atime = theObject->st_mtime = theObject->st_ctime = CURRENT_TIME;
+
+ switch(type)
+ {
+ case YAFFS_OBJECT_TYPE_FILE:
+ theObject->variant.fileVariant.fileSize = 0;
+ theObject->variant.fileVariant.topLevel = 0;
+ theObject->variant.fileVariant.top = yaffs_GetTnode(dev);
+ break;
+ case YAFFS_OBJECT_TYPE_DIRECTORY:
+ INIT_LIST_HEAD(&theObject->variant.directoryVariant.children);
+ break;
+ case YAFFS_OBJECT_TYPE_SYMLINK:
+ break;
+ case YAFFS_OBJECT_TYPE_HARDLINK:
+ break;
+ case YAFFS_OBJECT_TYPE_UNKNOWN:
+ // todo this should not happen
+ }
+ }
+
+ return theObject;
+}
+
+yaffs_Object *yaffs_FindOrCreateObjectByNumber(yaffs_Device *dev, int number,yaffs_ObjectType type)
+{
+ yaffs_Object *theObject = NULL;
+
+ if(number >= 0)
+ {
+ theObject = yaffs_FindObjectByNumber(dev,number);
+ }
+
+ if(!theObject)
+ {
+ theObject = yaffs_CreateNewObject(dev,number,type);
+ }
+
+ return theObject;
+
+}
+
+char *yaffs_CloneString(const char *str)
+{
+ char *newStr = NULL;
+
+ if(str && *str)
+ {
+ newStr = YMALLOC(strlen(str) + 1);
+ strcpy(newStr,str);
+ }
+
+ return newStr;
+
+}
+
+//
+// Mknod (create) a new object.
+// equivalentObject only has meaning for a hard link;
+// aliasString only has meaning for a sumlink.
+yaffs_Object *yaffs_MknodObject( yaffs_ObjectType type,
+ yaffs_Object *parent,
+ const char *name,
+ __u32 mode,
+ __u32 uid,
+ __u32 gid,
+ yaffs_Object *equivalentObject,
+ const char *aliasString)
+{
+ yaffs_Object *in;
+
+ yaffs_Device *dev = parent->myDev;
+
+ in = yaffs_CreateNewObject(dev,-1,type);
+
+ if(in)
+ {
+ in->chunkId = -1;
+ in->valid = 1;
+ in->variantType = type;
+
+ in->st_mode = mode;
+ in->st_uid = uid;
+ in->st_gid = gid;
+ in->st_atime = in->st_mtime = in->st_ctime = CURRENT_TIME;
+
+ in->sum = yaffs_CalcNameSum(name);
+ in->dirty = 1;
+
+ yaffs_AddObjectToDirectory(parent,in);
+
+ in->myDev = parent->myDev;
+
+
+ switch(type)
+ {
+ case YAFFS_OBJECT_TYPE_SYMLINK:
+ in->variant.symLinkVariant.alias = yaffs_CloneString(aliasString);
+ break;
+ case YAFFS_OBJECT_TYPE_HARDLINK:
+ in->variant.hardLinkVariant.equivalentObject = equivalentObject;
+ in->variant.hardLinkVariant.equivalentObjectId = equivalentObject->objectId;
+ list_add(&in->hardLinks,&equivalentObject->hardLinks);
+ break;
+ case YAFFS_OBJECT_TYPE_FILE: // do nothing
+ case YAFFS_OBJECT_TYPE_DIRECTORY: // do nothing
+ case YAFFS_OBJECT_TYPE_UNKNOWN:
+ }
+
+ yaffs_UpdateObjectHeader(in,name);
+
+ }
+
+ return in;
+}
+
+yaffs_Object *yaffs_MknodFile(yaffs_Object *parent,const char *name, __u32 mode, __u32 uid, __u32 gid)
+{
+ return yaffs_MknodObject(YAFFS_OBJECT_TYPE_FILE,parent,name,mode,uid,gid,NULL,NULL);
+}
+
+yaffs_Object *yaffs_MknodDirectory(yaffs_Object *parent,const char *name, __u32 mode, __u32 uid, __u32 gid)
+{
+ return yaffs_MknodObject(YAFFS_OBJECT_TYPE_DIRECTORY,parent,name,mode,uid,gid,NULL,NULL);
+}
+
+yaffs_Object *yaffs_MknodSymLink(yaffs_Object *parent,const char *name, __u32 mode, __u32 uid, __u32 gid,const char *alias)
+{
+ return yaffs_MknodObject(YAFFS_OBJECT_TYPE_SYMLINK,parent,name,mode,uid,gid,NULL,alias);
+}
+
+// NB yaffs_Link returns the object id of the equivalent object.
+yaffs_Object *yaffs_Link(yaffs_Object *parent, const char *name, yaffs_Object *equivalentObject)
+{
+ // Get the real object in case we were fed a hard link as an equivalent object
+ equivalentObject = yaffs_GetEquivalentObject(equivalentObject);
+
+ if(yaffs_MknodObject(YAFFS_OBJECT_TYPE_HARDLINK,parent,name,0,0,0,equivalentObject,NULL))
+ {
+ return equivalentObject;
+ }
+ else
+ {
+ return NULL;
+ }
+
+}
+
+
+static int yaffs_ChangeObjectName(yaffs_Object *obj, yaffs_Object *newDir, const char *newName)
+{
+ //yaffs_Device *dev = obj->myDev;
+
+ if(newDir == NULL)
+ {
+ newDir = obj->parent; // use the old directory
+ }
+
+ // Only proceed if the new name does not exist and
+ // if we're putting it into a directory.
+ if(!yaffs_FindObjectByName(newDir,newName) &&
+ newDir->variantType == YAFFS_OBJECT_TYPE_DIRECTORY)
+ {
+ obj->sum = yaffs_CalcNameSum(newName);
+ obj->dirty = 1;
+ yaffs_AddObjectToDirectory(newDir,obj);
+
+ return yaffs_UpdateObjectHeader(obj,newName);
+ }
+
+ return YAFFS_FAIL;
+}
+
+int yaffs_RenameObject(yaffs_Object *oldDir, const char *oldName, yaffs_Object *newDir, const char *newName)
+{
+ yaffs_Object *obj;
+
+ obj = yaffs_FindObjectByName(oldDir,oldName);
+ if(obj && obj->renameAllowed)
+ {
+ return yaffs_ChangeObjectName(obj,newDir,newName);
+ }
+ return YAFFS_FAIL;
+}
+
+
+
+static int yaffs_CheckObjectHashSanity(yaffs_Device *dev)
+{
+ // Scan the buckets and check that the lists
+ // have as many members as the count says there are
+ int bucket;
+ int countEm;
+ struct list_head *j;
+ int ok = YAFFS_OK;
+
+ for(bucket = 0; bucket < YAFFS_NOBJECT_BUCKETS; bucket++)
+ {
+ countEm = 0;
+
+ list_for_each(j,&dev->objectBucket[bucket].list)
+ {
+ countEm++;
+ }
+
+ if(countEm != dev->objectBucket[bucket].count)
+ {
+ YALERT("Inode hash inconsistency");
+ ok = YAFFS_FAIL;
+ }
+ }
+
+ return ok;
+}
+
+void yaffs_ObjectTest(yaffs_Device *dev)
+{
+ yaffs_Object *in[1000];
+ int inNo[1000];
+ yaffs_Object *inold[1000];
+ int i;
+ int j;
+
+ memset(in,0,1000*sizeof(yaffs_Object *));
+ memset(inold,0,1000*sizeof(yaffs_Object *));
+
+ yaffs_CheckObjectHashSanity(dev);
+
+ for(j = 0; j < 10; j++)
+ {
+ T(("%d\n",j));
+
+ for(i = 0; i < 1000; i++)
+ {
+ in[i] = yaffs_CreateNewObject(dev,-1,YAFFS_OBJECT_TYPE_FILE);
+ if(!in[i])
+ {
+ YINFO("No more inodes");
+ }
+ else
+ {
+ inNo[i] = in[i]->objectId;
+ }
+ }
+
+ for(i = 0; i < 1000; i++)
+ {
+ if(yaffs_FindObjectByNumber(dev,inNo[i]) != in[i])
+ {
+ T(("Differnce in look up test\n"));
+ }
+ else
+ {
+ // T(("Look up ok\n"));
+ }
+ }
+
+ yaffs_CheckObjectHashSanity(dev);
+
+ for(i = 0; i < 1000; i+=3)
+ {
+ yaffs_FreeObject(in[i]);
+ in[i] = NULL;
+ }
+
+
+ yaffs_CheckObjectHashSanity(dev);
+ }
+
+}
+
+
+
+/////////////////////////// Block Management and Page Allocation ///////////////////
+
+
+static void yaffs_InitialiseBlocks(yaffs_Device *dev)
+{
+ dev->blockInfo = YMALLOC(dev->nBlocks * sizeof(yaffs_BlockInfo));
+ memset(dev->blockInfo,0,dev->nBlocks * sizeof(yaffs_BlockInfo));
+ dev->allocationBlock = -1; // force it to get a new one
+}
+
+static void yaffs_DeinitialiseBlocks(yaffs_Device *dev)
+{
+ YFREE(dev->blockInfo);
+}
+
+// FindDiretiestBlock is used to select the dirtiest block (or close enough)
+// for garbage collection.
+
+static int yaffs_FindDirtiestBlock(yaffs_Device *dev)
+{
+
+ int b = dev->currentDirtyChecker;
+
+ int i;
+ int dirtiest = -1;
+ int pagesInUse = 100; // silly big number
+
+ for(i = dev->startBlock; i <= dev->endBlock && pagesInUse > 2 ; i++)
+ {
+ b++;
+ if (b > dev->endBlock)
+ {
+ b = dev->startBlock;
+ }
+
+ if(dev->blockInfo[b].blockState == YAFFS_BLOCK_STATE_FULL &&
+ (dev->blockInfo)[b].pagesInUse < pagesInUse)
+ {
+ dirtiest = b;
+ pagesInUse = (dev->blockInfo)[b].pagesInUse;
+ }
+ }
+
+ dev->currentDirtyChecker = b;
+
+ return dirtiest;
+}
+
+
+static int yaffs_FindBlockForAllocation(yaffs_Device *dev,int useReserve)
+{
+ int i;
+
+ if(useReserve && dev->nErasedBlocks < 1)
+ {
+ // Hoosterman we've got a problem.
+ // Can't get space to gc
+ return -1;
+ }
+ else if(!useReserve && dev->nErasedBlocks <= YAFFS_RESERVED_BLOCKS)
+ {
+ // We are not in GC, so we hold some in reserve so we can get
+ // a gc done.
+ }
+
+ // Find an empty block.
+
+ for(i = dev->startBlock; i <= dev->endBlock; i++)
+ {
+
+ if(dev->blockInfo[i].blockState == YAFFS_BLOCK_STATE_EMPTY)
+ {
+ dev->blockInfo[i].blockState = YAFFS_BLOCK_STATE_ALLOCATING;
+ dev->nErasedBlocks--;
+ if(dev->nErasedBlocks <= YAFFS_RESERVED_BLOCKS)
+ {
+ dev->garbageCollectionRequired = 1;
+ }
+
+ return i;
+ }
+ }
+
+ return -1;
+}
+
+
+static void yaffs_BlockBecameDirty(yaffs_Device *dev,int blockNo)
+{
+ yaffs_BlockInfo *bi = &dev->blockInfo[blockNo];
+
+ // Mark as dirty, erase it and mark as clean.
+ bi->blockState = YAFFS_BLOCK_STATE_DIRTY;
+ yaffs_EraseBlockInNAND(dev,blockNo);
+ bi->blockState = YAFFS_BLOCK_STATE_EMPTY;
+ dev->nErasedBlocks++;
+ bi->pagesInUse = 0;
+ bi->pageBits = 0;
+
+ T(("Erased block %d\n",blockNo));
+}
+
+
+static int yaffs_AllocateChunk(yaffs_Device *dev,int useReserve)
+{
+ int retVal;
+
+ if(dev->allocationBlock < 0)
+ {
+ // Get next block to allocate off
+ dev->allocationBlock = yaffs_FindBlockForAllocation(dev,useReserve);
+ dev->allocationPage = 0;
+ }
+
+ // Next page please....
+ if(dev->allocationBlock >= 0)
+ {
+ retVal = (dev->allocationBlock * YAFFS_CHUNKS_PER_BLOCK) +
+ dev->allocationPage;
+ dev->blockInfo[dev->allocationBlock].pagesInUse++;
+ dev->blockInfo[dev->allocationBlock].pageBits |=
+ (1 << (dev->allocationPage));
+
+ dev->allocationPage++;
+
+ dev->nFreeChunks--;
+
+ // If the block is full set the state to full
+ if(dev->allocationPage >= YAFFS_CHUNKS_PER_BLOCK)
+ {
+ dev->blockInfo[dev->allocationBlock].blockState = YAFFS_BLOCK_STATE_FULL;
+ dev->allocationBlock = -1;
+ }
+
+#ifdef YAFFS_PARANOID
+ if(yaffs_CheckChunkErased(retVal) == YAFFS_FAIL)
+ {
+ T(("..................Trying to allocate non-erased page %d\n",retVal));
+ }
+#endif
+ return retVal;
+
+ }
+ T(("!!!!!!!!! Allocator out !!!!!!!!!!!!!!!!!\n"));
+
+ return -1;
+}
+
+
+int yaffs_GarbageCollectBlock(yaffs_Device *dev,int block)
+{
+ int oldChunk;
+ int newChunk;
+ __u32 mask;
+
+
+ yaffs_Spare spare;
+ yaffs_Tags tags;
+ __u8 buffer[YAFFS_BYTES_PER_CHUNK];
+
+ yaffs_BlockInfo *bi = &dev->blockInfo[block];
+
+ yaffs_Object *object;
+
+ T(("Collecting block %d n %d bits %x\n",block, bi->pagesInUse, bi->pageBits));
+
+ for(mask = 1,oldChunk = block * YAFFS_CHUNKS_PER_BLOCK;
+ mask && bi->pageBits;
+ mask <<= 1, oldChunk++ )
+ {
+ if(bi->pageBits & mask)
+ {
+
+ // This page is in use and needs to be copied off
+
+ T(("copying page %x from %d to %d\n",mask,oldChunk,newChunk));
+
+ yaffs_ReadChunkFromNAND(dev,oldChunk,buffer, &spare);
+
+ yaffs_GetTagsFromSpare(&spare,&tags);
+ tags.serialNumber++;
+ yaffs_LoadTagsIntoSpare(&spare,&tags);
+
+#if 0
+ newChunk = yaffs_AllocatePage(dev,1);
+ if(newChunk < 0)
+ {
+ return YAFFS_FAIL;
+ }
+
+ yaffs_WriteChunkToNAND(dev,newChunk, buffer, &spare);
+
+#else
+ newChunk = yaffs_WriteNewChunkToNAND(dev, buffer, &spare,1);
+#endif
+ if(newChunk < 0)
+ {
+ return YAFFS_FAIL;
+ }
+
+ object = yaffs_FindObjectByNumber(dev,tags.objectId);
+
+ // Ok, now fix up the Tnodes etc.
+
+ if(tags.chunkId == 0)
+ {
+ // It's a header
+ object->chunkId = newChunk;
+ }
+ else
+ {
+ // It's a data chunk
+ yaffs_PutChunkIntoFile(object, tags.chunkId, newChunk);
+
+ }
+
+ yaffs_DeleteChunk(dev,oldChunk);
+
+ }
+ }
+
+ return YAFFS_OK;
+}
+
+int yaffs_CheckGarbageCollection(yaffs_Device *dev)
+{
+ int block;
+
+ if(dev->garbageCollectionRequired)
+ {
+ dev->garbageCollectionRequired = 0;
+ block = yaffs_FindDirtiestBlock(dev);
+ if(block >= 0)
+ {
+ return yaffs_GarbageCollectBlock(dev,block);
+ }
+ else
+ {
+ return YAFFS_FAIL;
+ }
+ }
+
+ return YAFFS_OK;
+}
+
+
+//////////////////////////// TAGS ///////////////////////////////////////
+
+static void yaffs_LoadTagsIntoSpare(yaffs_Spare *sparePtr, yaffs_Tags *tagsPtr)
+{
+ yaffs_TagsUnion *tu = (yaffs_TagsUnion *)tagsPtr;
+
+ yaffs_CalcTagsECC(tagsPtr);
+
+ sparePtr->tagByte0 = tu->asBytes[0];
+ sparePtr->tagByte1 = tu->asBytes[1];
+ sparePtr->tagByte2 = tu->asBytes[2];
+ sparePtr->tagByte3 = tu->asBytes[3];
+ sparePtr->tagByte4 = tu->asBytes[4];
+ sparePtr->tagByte5 = tu->asBytes[5];
+ sparePtr->tagByte6 = tu->asBytes[6];
+ sparePtr->tagByte7 = tu->asBytes[7];
+}
+
+static void yaffs_GetTagsFromSpare(yaffs_Spare *sparePtr,yaffs_Tags *tagsPtr)
+{
+ yaffs_TagsUnion *tu = (yaffs_TagsUnion *)tagsPtr;
+
+ tu->asBytes[0]= sparePtr->tagByte0;
+ tu->asBytes[1]= sparePtr->tagByte1;
+ tu->asBytes[2]= sparePtr->tagByte2;
+ tu->asBytes[3]= sparePtr->tagByte3;
+ tu->asBytes[4]= sparePtr->tagByte4;
+ tu->asBytes[5]= sparePtr->tagByte5;
+ tu->asBytes[6]= sparePtr->tagByte6;
+ tu->asBytes[7]= sparePtr->tagByte7;
+
+ // Todo Check ECC on tags
+}
+
+static void yaffs_SpareInitialise(yaffs_Spare *spare)
+{
+ memset(spare,0xFF,sizeof(yaffs_Spare));
+}
+
+static int yaffs_ReadChunkTagsFromNAND(yaffs_Device *dev,int chunkInNAND, yaffs_Tags *tags)
+{
+ if(tags)
+ {
+ yaffs_Spare spare;
+ if(yaffs_ReadChunkFromNAND(dev,chunkInNAND,NULL,&spare) == YAFFS_OK)
+ {
+ yaffs_GetTagsFromSpare(&spare,tags);
+ return YAFFS_OK;
+ }
+ else
+ {
+ return YAFFS_FAIL;
+ }
+ }
+
+ return YAFFS_OK;
+}
+
+static int yaffs_WriteChunkWithTagsToNAND(yaffs_Device *dev,int chunkInNAND, const __u8 *buffer, yaffs_Tags *tags)
+{
+ // NB There must be tags, data is optional
+ // If there is data, then an ECC is calculated on it.
+
+ yaffs_Spare spare;
+
+ if(!tags)
+ {
+ return YAFFS_FAIL;
+ }
+
+ yaffs_SpareInitialise(&spare);
+
+
+ if(buffer)
+ {
+ yaffs_CalcECC(buffer,&spare);
+ }
+
+ yaffs_LoadTagsIntoSpare(&spare,tags);
+
+ return yaffs_WriteChunkToNAND(dev,chunkInNAND,buffer,&spare);
+
+}
+
+static int yaffs_WriteNewChunkWithTagsToNAND(yaffs_Device *dev, const __u8 *buffer, yaffs_Tags *tags, int useReserve)
+{
+ // NB There must be tags, data is optional
+ // If there is data, then an ECC is calculated on it.
+
+ yaffs_Spare spare;
+
+ if(!tags)
+ {
+ return YAFFS_FAIL;
+ }
+
+ yaffs_SpareInitialise(&spare);
+
+
+ if(buffer)
+ {
+ yaffs_CalcECC(buffer,&spare);
+ }
+
+ yaffs_LoadTagsIntoSpare(&spare,tags);
+
+ return yaffs_WriteNewChunkToNAND(dev,buffer,&spare,useReserve);
+
+}
+
+
+
+
+int yaffs_FindChunkInFile(yaffs_Object *in,int chunkInInode,yaffs_Tags *tags)
+{
+ //Get the Tnode, then get the level 0 offset chunk offset
+ yaffs_Tnode *tn;
+ int theChunk = -1;
+ yaffs_Tags localTags;
+ int i;
+ int found = 0;
+ yaffs_Device *dev = in->myDev;
+
+
+ if(!tags)
+ {
+ // Passed a NULL, so use our own tags space
+ tags = &localTags;
+ }
+
+ tn = yaffs_FindLevel0Tnode(dev,&in->variant.fileVariant, chunkInInode);
+
+ if(tn)
+ {
+ theChunk = tn->level0[chunkInInode & YAFFS_TNODES_LEVEL0_MASK] << dev->chunkGroupBits;
+
+ // Now we need to do the shifting etc and search for it
+ for(i = 0,found = 0; i < dev->chunkGroupSize && !found; i++)
+ {
+ yaffs_ReadChunkTagsFromNAND(dev,theChunk,tags);
+ if(tags->chunkId == chunkInInode &&
+ tags->objectId == in->objectId)
+ {
+ // found it;
+ found = 1;
+ }
+ else
+ {
+ theChunk++;
+ }
+ }
+ }
+ return found ? theChunk : -1;
+}
+
+int yaffs_FindAndDeleteChunkInFile(yaffs_Object *in,int chunkInInode,yaffs_Tags *tags)
+{
+ //Get the Tnode, then get the level 0 offset chunk offset
+ yaffs_Tnode *tn;
+ int theChunk = -1;
+ yaffs_Tags localTags;
+ int i;
+ int found = 0;
+ yaffs_Device *dev = in->myDev;
+
+ if(!tags)
+ {
+ // Passed a NULL, so use our own tags space
+ tags = &localTags;
+ }
+
+ tn = yaffs_FindLevel0Tnode(dev,&in->variant.fileVariant, chunkInInode);
+
+ if(tn)
+ {
+
+ theChunk = tn->level0[chunkInInode & YAFFS_TNODES_LEVEL0_MASK] << dev->chunkGroupBits;
+
+ // Now we need to do the shifting etc and search for it
+ for(i = 0,found = 0; i < dev->chunkGroupSize && !found; i++)
+ {
+ yaffs_ReadChunkTagsFromNAND(dev,theChunk,tags);
+ if(tags->chunkId == chunkInInode &&
+ tags->objectId == in->objectId)
+ {
+ // found it;
+ found = 1;
+ }
+ else
+ {
+ theChunk++;
+ }
+ }
+
+ // Delete the entry in the filestructure
+ if(found)
+ {
+ tn->level0[chunkInInode & YAFFS_TNODES_LEVEL0_MASK] = 0;
+ }
+ }
+ else
+ {
+ T(("No level 0 found for %d\n", chunkInInode));
+ }
+
+ if(!found)
+ {
+ T(("Could not find %d to delete\n",chunkInInode));
+ }
+ return found ? theChunk : -1;
+}
+
+
+#if YAFFS_PARANOID
+
+static int yaffs_CheckFileSanity(yaffs_Object *in)
+{
+ int chunk;
+ int nChunks;
+ int fSize;
+ int failed = 0;
+ int objId;
+ yaffs_Tnode *tn;
+ yaffs_Tags localTags;
+ yaffs_Tags *tags = &localTags;
+ int theChunk;
+
+
+ if(in->variantType != YAFFS_OBJECT_TYPE_FILE)
+ {
+ T(("Object not a file\n"));
+ return YAFFS_FAIL;
+ }
+
+ objId = in->objectId;
+ fSize = in->variant.fileVariant.fileSize;
+ nChunks = (fSize + YAFFS_BYTES_PER_CHUNK -1)/YAFFS_BYTES_PER_CHUNK;
+
+ for(chunk = 1; chunk <= nChunks; chunk++)
+ {
+ tn = yaffs_FindLevel0Tnode(&in->variant.fileVariant, chunk);
+
+ if(tn)
+ {
+
+ theChunk = tn->level0[chunk & YAFFS_TNODES_LEVEL0_MASK] << dev->chunkGroupBits;
+
+
+ yaffs_ReadChunkTagsFromNAND(theChunk,tags);
+ if(tags->chunkId == chunk &&
+ tags->objectId == in->objectId)
+ {
+ // found it;
+
+ }
+ else
+ {
+ //T(("File problem file [%d,%d] NAND %d tags[%d,%d]\n",
+ // objId,chunk,theChunk,tags->chunkId,tags->objectId);
+
+ failed = 1;
+
+ }
+
+ }
+ else
+ {
+ T(("No level 0 found for %d\n", chunk));
+ }
+ }
+
+ return failed ? YAFFS_FAIL : YAFFS_OK;
+}
+
+#endif
+
+static int yaffs_PutChunkIntoFile(yaffs_Object *in,int chunkInInode, int chunkInNAND)
+{
+ yaffs_Tnode *tn;
+ yaffs_Device *dev = in->myDev;
+
+ tn = yaffs_AddOrFindLevel0Tnode(dev,&in->variant.fileVariant, chunkInInode);
+ tn->level0[chunkInInode & YAFFS_TNODES_LEVEL0_MASK] = chunkInNAND;
+ return YAFFS_OK;
+}
+
+
+
+int yaffs_ReadChunkDataFromObject(yaffs_Object *in,int chunkInInode, __u8 *buffer)
+{
+ int chunkInNAND = yaffs_FindChunkInFile(in,chunkInInode,NULL);
+
+ if(chunkInNAND >= 0)
+ {
+ return yaffs_ReadChunkFromNAND(in->myDev,chunkInNAND,buffer,NULL);
+ }
+ else
+ {
+ return 0;
+ }
+
+}
+
+
+static void yaffs_DeleteChunk(yaffs_Device *dev,int chunkId)
+{
+ int block = chunkId / YAFFS_CHUNKS_PER_BLOCK;
+ int page = chunkId % YAFFS_CHUNKS_PER_BLOCK;
+ yaffs_Tags tags;
+
+ // Mark the deleted NAND page as deleted
+ tags.chunkId = 0;
+ tags.objectId = 0;
+ tags.byteCount = 0;
+ tags.ecc = 0;
+
+ yaffs_WriteChunkWithTagsToNAND(dev,chunkId,NULL,&tags);
+
+
+ // Pull out of the management area.
+ if( dev->blockInfo[block].blockState == YAFFS_BLOCK_STATE_ALLOCATING ||
+ dev->blockInfo[block].blockState == YAFFS_BLOCK_STATE_FULL)
+ {
+ dev->nFreeChunks++;
+
+ dev->blockInfo[block].pageBits &= ~(1 << page);
+ dev->blockInfo[block].pagesInUse--;
+
+ if( dev->blockInfo[block].pagesInUse == 0 &&
+ dev->blockInfo[block].blockState == YAFFS_BLOCK_STATE_FULL)
+ {
+ yaffs_BlockBecameDirty(dev,block);
+ }
+
+ }
+ else
+ {
+ T(("Bad news deteing chunk %d\n",chunkId));
+ }
+
+}
+
+
+
+
+int yaffs_WriteChunkDataToObject(yaffs_Object *in,int chunkInInode, const __u8 *buffer,int nBytes,int useReserve)
+{
+ // Find old chunk Need to do this to get serial number
+ // Write new one and patch into tree.
+ // Invalidate old tags.
+
+ int prevChunkId;
+ yaffs_Tags prevTags;
+
+ int newChunkId;
+ yaffs_Tags newTags;
+
+ yaffs_Device *dev = in->myDev;
+
+ yaffs_CheckGarbageCollection(dev);
+
+ // Get the previous chunk at this location in the file if it exists
+ prevChunkId = yaffs_FindChunkInFile(in,chunkInInode,&prevTags);
+
+ // Set up new tags
+ newTags.chunkId = chunkInInode;
+ newTags.objectId = in->objectId;
+ newTags.serialNumber = (prevChunkId >= 0) ? prevTags.serialNumber + 1 : 1;
+ newTags.byteCount = nBytes;
+ newTags.unusedStuff = 0xFFFFFFFF;
+
+ yaffs_CalcTagsECC(&newTags);
+
+
+ #if 0
+ // Create new chunk in NAND
+ newChunkId = yaffs_AllocatePage(dev,useReserve);
+
+
+ if(newChunkId >= 0)
+ {
+
+
+ yaffs_WriteChunkWithTagsToNAND(dev,newChunkId,buffer,&newTags);
+
+ yaffs_PutChunkIntoFile(in,chunkInInode,newChunkId);
+
+
+ if(prevChunkId >= 0)
+ {
+ yaffs_DeleteChunk(dev,prevChunkId);
+
+ }
+
+ yaffs_CheckFileSanity(in);
+
+ return newChunkId;
+ }
+
+
+ return -1;
+#else
+
+ newChunkId = yaffs_WriteNewChunkWithTagsToNAND(dev,buffer,&newTags,useReserve);
+ if(newChunkId >= 0)
+ {
+ yaffs_PutChunkIntoFile(in,chunkInInode,newChunkId);
+
+
+ if(prevChunkId >= 0)
+ {
+ yaffs_DeleteChunk(dev,prevChunkId);
+
+ }
+
+ yaffs_CheckFileSanity(in);
+ }
+ return newChunkId;
+
+#endif
+
+
+
+}
+
+
+// UpdateObjectHeader updates the header on NAND for an object.
+// If name is not NULL, then that new name is used.
+//
+int yaffs_UpdateObjectHeader(yaffs_Object *in,const char *name)
+{
+
+ yaffs_Device *dev = in->myDev;
+
+ int prevChunkId;
+
+ int newChunkId;
+ yaffs_Tags newTags;
+ __u8 bufferNew[YAFFS_BYTES_PER_CHUNK];
+ __u8 bufferOld[YAFFS_BYTES_PER_CHUNK];
+
+ yaffs_ObjectHeader *oh = (yaffs_ObjectHeader *)bufferNew;
+ yaffs_ObjectHeader *ohOld = (yaffs_ObjectHeader *)bufferOld;
+
+ if(!in->fake)
+ {
+
+ yaffs_CheckGarbageCollection(dev);
+
+ memset(bufferNew,0xFF,YAFFS_BYTES_PER_CHUNK);
+
+ prevChunkId = in->chunkId;
+
+ if(prevChunkId >= 0)
+ {
+ yaffs_ReadChunkFromNAND(dev,prevChunkId,bufferOld,NULL);
+ }
+
+ // Header data
+ oh->type = in->variantType;
+
+ oh->st_mode = in->st_mode;
+ oh->st_uid = in->st_uid;
+ oh->st_gid = in->st_gid;
+ oh->st_atime = in->st_atime;
+ oh->st_mtime = in->st_mtime;
+ oh->st_ctime = in->st_ctime;
+
+ oh->parentObjectId = in->parent->objectId;
+ oh->sum = in->sum;
+ if(name && *name)
+ {
+ memset(oh->name,0,YAFFS_MAX_NAME_LENGTH + 1);
+ strncpy(oh->name,name,YAFFS_MAX_NAME_LENGTH);
+ }
+ else
+ {
+ memcpy(oh->name, ohOld->name,YAFFS_MAX_NAME_LENGTH + 1);
+ }
+
+ switch(in->variantType)
+ {
+ case YAFFS_OBJECT_TYPE_UNKNOWN: // Todo got a problem
+ break;
+ case YAFFS_OBJECT_TYPE_FILE:
+ oh->fileSize = in->variant.fileVariant.fileSize;
+ break;
+ case YAFFS_OBJECT_TYPE_HARDLINK:
+ oh->equivalentObjectId = in->variant.hardLinkVariant.equivalentObjectId;
+ break;
+ case YAFFS_OBJECT_TYPE_DIRECTORY: // Do nothing
+ break;
+ case YAFFS_OBJECT_TYPE_SYMLINK:
+ strncpy(oh->alias,in->variant.symLinkVariant.alias,YAFFS_MAX_ALIAS_LENGTH);
+ oh->alias[YAFFS_MAX_ALIAS_LENGTH] = 0;
+ break;
+ }
+
+ // Tags
+ in->serial++;
+ newTags.chunkId = 0;
+ newTags.objectId = in->objectId;
+ newTags.serialNumber = in->serial;
+ newTags.byteCount = 0xFFFFFFFF;
+ newTags.unusedStuff = 0xFFFFFFFF;
+
+ yaffs_CalcTagsECC(&newTags);
+
+
+
+#if 0
+ // Create new chunk in NAND
+ newChunkId = yaffs_AllocatePage(dev,1);
+
+ if(newChunkId >= 0)
+ {
+
+ yaffs_WriteChunkWithTagsToNAND(dev,newChunkId,bufferNew,&newTags);
+
+ in->chunkId = newChunkId;
+
+ if(prevChunkId >= 0)
+ {
+ yaffs_DeleteChunk(dev,prevChunkId);
+ }
+
+ in->dirty = 0;
+ return newChunkId;
+ }
+
+ return -1;
+#else
+ // Create new chunk in NAND
+ newChunkId = yaffs_WriteNewChunkWithTagsToNAND(dev,bufferNew,&newTags,1);
+
+ if(newChunkId >= 0)
+ {
+
+ in->chunkId = newChunkId;
+
+ if(prevChunkId >= 0)
+ {
+ yaffs_DeleteChunk(dev,prevChunkId);
+ }
+
+ in->dirty = 0;
+ }
+
+ return newChunkId;
+
+#endif
+ }
+ return 0;
+}
+
+
+
+///////////////////////// File read/write ///////////////////////////////
+// Read and write have very similar structures.
+// In general the read/write has three parts to it
+// * An incomplete chunk to start with (if the read/write is not chunk-aligned)
+// * Some complete chunks
+// * An incomplete chunk to end off with
+//
+// Curve-balls: the first chunk might also be the last chunk.
+
+int yaffs_ReadDataFromFile(yaffs_Object *in, __u8 * buffer, __u32 offset, int nBytes)
+{
+
+// yaffs_Device *dev = in->myDev;
+
+ __u8 localBuffer[YAFFS_BYTES_PER_CHUNK];
+
+ int chunk;
+ int start;
+ int nToCopy;
+ int n = nBytes;
+ int nDone = 0;
+
+ while(n > 0)
+ {
+ chunk = offset / YAFFS_BYTES_PER_CHUNK + 1; // The first chunk is 1
+ start = offset % YAFFS_BYTES_PER_CHUNK;
+
+ // OK now check for the curveball where the start and end are in
+ // the same chunk.
+ if( (start + n) < YAFFS_BYTES_PER_CHUNK)
+ {
+ nToCopy = n;
+ }
+ else
+ {
+ nToCopy = YAFFS_BYTES_PER_CHUNK - start;
+ }
+
+ if(nToCopy != YAFFS_BYTES_PER_CHUNK)
+ {
+ // An incomplete start or end chunk (or maybe both start and end chunk)
+ // Read into the local buffer then copy...
+
+ yaffs_ReadChunkDataFromObject(in,chunk,localBuffer);
+ memcpy(buffer,&localBuffer[start],nToCopy);
+ }
+ else
+ {
+ // A full chunk. Read directly into the supplied buffer.
+ yaffs_ReadChunkDataFromObject(in,chunk,buffer);
+ }
+
+ n -= nToCopy;
+ offset += nToCopy;
+ buffer += nToCopy;
+ nDone += nToCopy;
+
+ }
+
+ return nDone;
+}
+
+
+int yaffs_WriteDataToFile(yaffs_Object *in,const __u8 * buffer, __u32 offset, int nBytes)
+{
+ __u8 localBuffer[YAFFS_BYTES_PER_CHUNK];
+
+ int chunk;
+ int start;
+ int nToCopy;
+ int n = nBytes;
+ int nDone = 0;
+ int nToWriteBack;
+ int endOfWrite = offset+nBytes;
+ int chunkWritten = 0;
+
+ while(n > 0 && chunkWritten >= 0)
+ {
+ chunk = offset / YAFFS_BYTES_PER_CHUNK + 1;
+ start = offset % YAFFS_BYTES_PER_CHUNK;
+
+
+ // OK now check for the curveball where the start and end are in
+ // the same chunk.
+ if( (start + n) < YAFFS_BYTES_PER_CHUNK)
+ {
+ nToCopy = n;
+ nToWriteBack = (start + n);
+ }
+ else
+ {
+ nToCopy = YAFFS_BYTES_PER_CHUNK - start;
+ nToWriteBack = YAFFS_BYTES_PER_CHUNK;
+ }
+
+ if(nToCopy != YAFFS_BYTES_PER_CHUNK)
+ {
+ // An incomplete start or end chunk (or maybe both start and end chunk)
+ // Read into the local buffer then copy, then copy over and write back.
+
+ yaffs_ReadChunkDataFromObject(in,chunk,localBuffer);
+
+ memcpy(&localBuffer[start],buffer,nToCopy);
+
+ chunkWritten = yaffs_WriteChunkDataToObject(in,chunk,localBuffer,nToWriteBack,0);
+
+ T(("Write with readback to chunk %d %d\n",chunk,chunkWritten));
+
+ }
+ else
+ {
+ // A full chunk. Write directly from the supplied buffer.
+ chunkWritten = yaffs_WriteChunkDataToObject(in,chunk,buffer,YAFFS_BYTES_PER_CHUNK,0);
+ T(("Write to chunk %d %d\n",chunk,chunkWritten));
+ }
+
+ if(chunkWritten >= 0)
+ {
+ n -= nToCopy;
+ offset += nToCopy;
+ buffer += nToCopy;
+ nDone += nToCopy;
+ }
+
+ }
+
+ // Update file object
+
+ if(endOfWrite > in->variant.fileVariant.fileSize)
+ {
+ in->variant.fileVariant.fileSize = endOfWrite;
+ }
+
+ in->dirty = 1;
+ in->st_mtime = CURRENT_TIME;
+
+ return nDone;
+}
+
+
+int yaffs_ResizeFile(yaffs_Object *in, int newSize)
+{
+ int i;
+ int chunkId;
+ int oldFileSize = in->variant.fileVariant.fileSize;
+ int sizeOfLastChunk = newSize % YAFFS_BYTES_PER_CHUNK;
+
+ yaffs_Device *dev = in->myDev;
+
+ __u8 localBuffer[YAFFS_BYTES_PER_CHUNK];
+
+ if(in->variantType != YAFFS_OBJECT_TYPE_FILE)
+ {
+ return yaffs_GetFileSize(in);
+ }
+
+ if(newSize < oldFileSize)
+ {
+
+ int lastDel = 1 + oldFileSize/YAFFS_BYTES_PER_CHUNK;
+
+ int startDel = 1 + (newSize + YAFFS_BYTES_PER_CHUNK - 1)/
+ YAFFS_BYTES_PER_CHUNK;
+
+ for(i = startDel; i <= lastDel; i++)
+ {
+ // NB this could be optimised somewhat,
+ // eg. could retrieve the tags and write them without
+ // using yaffs_DeleteChunk
+ chunkId = yaffs_FindAndDeleteChunkInFile(in,i,NULL);
+ if(chunkId < 0 || chunkId >= (dev->endBlock * 32))
+ {
+ T(("Found daft chunkId %d for %d\n",chunkId,i));
+ }
+ else
+ {
+ yaffs_DeleteChunk(dev,chunkId);
+ }
+ }
+
+
+ if(sizeOfLastChunk != 0)
+ {
+ int lastChunk = 1+ newSize/YAFFS_BYTES_PER_CHUNK;
+
+ // Got to read and rewrite the last chunk with its new size.
+ yaffs_ReadChunkDataFromObject(in,lastChunk,localBuffer);
+
+ yaffs_WriteChunkDataToObject(in,lastChunk,localBuffer,sizeOfLastChunk,1);
+
+ }
+
+ in->variant.fileVariant.fileSize = newSize;
+
+ yaffs_PruneFileStructure(dev,&in->variant.fileVariant);
+
+ return newSize;
+
+ }
+ else
+ {
+ return oldFileSize;
+ }
+}
+
+
+loff_t yaffs_GetFileSize(yaffs_Object *obj)
+{
+ obj = yaffs_GetEquivalentObject(obj);
+
+ switch(obj->variantType)
+ {
+ case YAFFS_OBJECT_TYPE_FILE:
+ return obj->variant.fileVariant.fileSize;
+ case YAFFS_OBJECT_TYPE_SYMLINK:
+ return strlen(obj->variant.symLinkVariant.alias);
+ default:
+ return 0;
+ }
+}
+
+
+
+// yaffs_FlushFile() updates the file's
+// objectId in NAND
+
+int yaffs_FlushFile(yaffs_Object *in)
+{
+ int retVal;
+ if(in->dirty)
+ {
+ retVal = yaffs_UpdateObjectHeader(in,NULL);
+ }
+ else
+ {
+ retVal = YAFFS_OK;
+ }
+
+ return retVal;
+
+}
+
+
+static int yaffs_DoGenericObjectDeletion(yaffs_Object *in)
+{
+ yaffs_RemoveObjectFromDirectory(in);
+ yaffs_DeleteChunk(in->myDev,in->chunkId);
+ yaffs_FreeObject(in);
+ return YAFFS_OK;
+
+}
+
+// yaffs_DeleteFile deletes the whole file data
+// and the inode associated with the file.
+// It does not delete the links associated with the file.
+static int yaffs_DeleteFile(yaffs_Object *in)
+{
+ // Delete the file data & tnodes
+ yaffs_ResizeFile(in,0);
+ yaffs_FreeTnode(in->myDev,in->variant.fileVariant.top);
+
+ return yaffs_DoGenericObjectDeletion(in);
+}
+
+static int yaffs_DeleteDirectory(yaffs_Object *in)
+{
+ //First check that the directory is empty.
+ if(list_empty(&in->variant.directoryVariant.children))
+ {
+ return yaffs_DoGenericObjectDeletion(in);
+ }
+
+ return YAFFS_FAIL;
+
+}
+
+static int yaffs_DeleteSymLink(yaffs_Object *in)
+{
+ YFREE(in->variant.symLinkVariant.alias);
+
+ return yaffs_DoGenericObjectDeletion(in);
+}
+
+static int yaffs_DeleteHardLink(yaffs_Object *in)
+{
+ // remove this hardlink from the list assocaited with the equivalent
+ // object
+ list_del(&in->hardLinks);
+ return yaffs_DoGenericObjectDeletion(in);
+}
+
+
+static int yaffs_UnlinkWorker(yaffs_Object *obj)
+{
+
+
+ if(obj->variantType == YAFFS_OBJECT_TYPE_HARDLINK)
+ {
+ return yaffs_DeleteHardLink(obj);
+ }
+ else if(!list_empty(&obj->hardLinks))
+ {
+#if 0
+ // Curve ball: We're unlinking an object that has a hardlink.
+ // Therefore we can't really delete the object.
+ // Instead, we do the following:
+ // - Select a hardlink.
+ // - Re-type a hardlink as the equivalent object and populate the fields, including the
+ // objectId. Updating the object id is important so that all the hardlinks do not need
+ // to be rewritten.
+ // - Update the equivalet object pointers.
+ // - Delete all object.
+
+ yaffs_Object *hl;
+ struct list_head *i;
+
+
+ yaffs_RemoveObjectFromDirectory(obj);
+
+
+
+ hl = list_entry(obj->hardLinks.next, yaffs_Object,hardLinks);
+
+ hl->dirty = 1;
+ hl->st_mode = obj->st_mode;
+ hl->st_uid = obj->st_uid;
+ hl->st_gid = obj->st_gid;
+ hl->st_atime = obj->st_atime;
+ hl->st_mtime = obj->st_mtime;
+ hl->st_ctime = obj->st_ctime;
+
+ hl->variantType = obj->variantType;
+
+ switch(hl->variantType)
+ {
+ case YAFFS_OBJECT_TYPE_FILE:
+ case YAFFS_OBJECT_TYPE_SYMLINK:
+ // These types are OK to just copy across.
+ hl->variant = obj->variant;
+ break;
+ case YAFFS_OBJECT_TYPE_DIRECTORY:
+ // Fix the list up
+ list_add(&hl->variant.directoryVariant.children,
+ &obj->variant.directoryVariant.children);
+ list_del(&obj->variant.directoryVariant.children);
+
+ // Now change all the directory children to point to the new parent.
+ list_for_each(i,&hl->variant.directoryVariant.children)
+ {
+ list_entry(i,yaffs_Object,siblings)->parent = hl;
+ }
+ break;
+
+ case YAFFS_OBJECT_TYPE_HARDLINK:
+ case YAFFS_OBJECT_TYPE_UNKNOWN:
+ // Should not be either of these types.
+ }
+
+ // Now fix up the hardlink chain
+ list_del(&obj->hardLinks);
+
+ list_for_each(i,&hl->hardLinks)
+ {
+ list_entry(i,yaffs_Object,hardLinks)->variant.hardLinkVariant.equivalentObject = hl;
+ list_entry(i,yaffs_Object,hardLinks)->variant.hardLinkVariant.equivalentObjectId = hl->objectId;
+ }
+
+ // Now fix up the hash links.
+ yaffs_UnhashObject(hl);
+ hl->objectId = obj->objectId;
+ yaffs_HashObject(hl);
+
+ // Update the hardlink which has become an object
+ yaffs_UpdateObjectHeader(hl,NULL);
+
+ // Finally throw away the deleted object
+ yaffs_DeleteChunk(obj->myDev,obj->chunkId);
+ yaffs_FreeObject(obj);
+
+ return YAFFS_OK;
+#else
+ // Curve ball: We're unlinking an object that has a hardlink.
+ //
+ // This problem arises because we are not strictly following
+ // The Linux link/inode model.
+ //
+ // We can't really delete the object.
+ // Instead, we do the following:
+ // - Select a hardlink.
+ // - Unhook it from the hard links
+ // - Unhook it from its parent directory (so that the rename can work)
+ // - Rename the object to the hardlink's name.
+ // - Delete the hardlink
+
+
+ yaffs_Object *hl;
+ int retVal;
+ char name[YAFFS_MAX_NAME_LENGTH+1];
+
+ hl = list_entry(obj->hardLinks.next,yaffs_Object,hardLinks);
+ list_del_init(&hl->hardLinks);
+ list_del_init(&hl->siblings);
+
+ yaffs_GetObjectName(hl,name,YAFFS_MAX_NAME_LENGTH+1);
+
+ retVal = yaffs_ChangeObjectName(obj, hl->parent, name);
+ if(retVal == YAFFS_OK)
+ {
+ retVal = yaffs_DoGenericObjectDeletion(hl);
+ }
+ return retVal;
+
+#endif
+
+
+ }
+ else
+ {
+ switch(obj->variantType)
+ {
+ case YAFFS_OBJECT_TYPE_FILE:
+ return yaffs_DeleteFile(obj);
+ break;
+ case YAFFS_OBJECT_TYPE_DIRECTORY:
+ return yaffs_DeleteDirectory(obj);
+ break;
+ case YAFFS_OBJECT_TYPE_SYMLINK:
+ return yaffs_DeleteSymLink(obj);
+ break;
+ case YAFFS_OBJECT_TYPE_HARDLINK:
+ case YAFFS_OBJECT_TYPE_UNKNOWN:
+ default:
+ return YAFFS_FAIL;
+ }
+ }
+}
+
+int yaffs_Unlink(yaffs_Object *dir, const char *name)
+{
+ yaffs_Object *obj;
+
+ obj = yaffs_FindObjectByName(dir,name);
+
+ if(obj && obj->unlinkAllowed)
+ {
+ return yaffs_UnlinkWorker(obj);
+ }
+
+ return YAFFS_FAIL;
+
+}
+
+//////////////// Initialisation Scanning /////////////////
+
+
+static int yaffs_Scan(yaffs_Device *dev)
+{
+ yaffs_Spare spare;
+ yaffs_Tags tags;
+ int blk;
+ int chunk;
+ int c;
+ int deleted;
+ int inuse;
+ yaffs_BlockState state;
+ yaffs_Object *hardList = NULL;
+ yaffs_Object *hl;
+
+ __u32 pageBits;
+
+ yaffs_ObjectHeader *oh;
+ yaffs_Object *in;
+ yaffs_Object *parent;
+
+ __u8 chunkData[YAFFS_BYTES_PER_CHUNK];
+
+ for(blk = dev->startBlock; blk <= dev->endBlock; blk++)
+ {
+ deleted = 0;
+ pageBits = 0;
+ inuse = 0;
+ state = YAFFS_BLOCK_STATE_UNKNOWN;
+
+ for(c = 0; c < YAFFS_CHUNKS_PER_BLOCK &&
+ state == YAFFS_BLOCK_STATE_UNKNOWN; c++)
+ {
+ // Read the spare area and decide what to do
+ chunk = blk * YAFFS_CHUNKS_PER_BLOCK + c;
+ yaffs_ReadChunkFromNAND(dev,chunk,NULL,&spare);
+
+
+ // Is this a valid block?
+ if(yaffs_countBits[spare.blockStatus] >= 7)
+ {
+ // This block looks ok, now what's in this chunk?
+ yaffs_GetTagsFromSpare(&spare,&tags);
+
+ if(tags.objectId == YAFFS_UNUSED_OBJECT_ID)
+ {
+ // An unassigned chunk in the block
+ // This means that either the block is empty or
+ // this is the one being allocated from
+
+ if(c == 0)
+ {
+ // the block is unused
+ state = YAFFS_BLOCK_STATE_EMPTY;
+ dev->nErasedBlocks++;
+ }
+ else
+ {
+ // this is the block being allocated from
+ T((" allocating %d %d\n",blk,c));
+ state = YAFFS_BLOCK_STATE_ALLOCATING;
+ dev->allocationBlock = blk;
+ dev->allocationPage = c;
+ }
+
+ dev->nFreeChunks += (YAFFS_CHUNKS_PER_BLOCK - c);
+ }
+ else if(tags.objectId == 0)
+ {
+ // A deleted chunk
+ deleted++;
+ dev->nFreeChunks ++;
+ T((" %d %d deleted\n",blk,c));
+ }
+ else if(tags.chunkId > 0)
+ {
+ // A data chunk.
+ inuse++;
+ pageBits |= ( 1 <<c);
+ in = yaffs_FindOrCreateObjectByNumber(dev,tags.objectId,YAFFS_OBJECT_TYPE_FILE);
+ // todo check for a clash (two data chunks with
+ // the same chunkId).
+ yaffs_PutChunkIntoFile(in,tags.chunkId,chunk);
+ T((" %d %d data %d %d\n",blk,c,tags.objectId,tags.chunkId));
+ }
+ else
+ {
+ // chunkId == 0, so it is an ObjectHeader.
+ inuse++;
+ pageBits |= ( 1 <<c);
+ yaffs_ReadChunkFromNAND(dev,chunk,chunkData,NULL);
+ oh = (yaffs_ObjectHeader *)chunkData;
+
+ in = yaffs_FindOrCreateObjectByNumber(dev,tags.objectId,oh->type);
+ if(in->valid)
+ {
+ // todo we have already filled this one. We have
+ // a duplicate. Need to fix
+ }
+
+ // we don't have a duplicate...
+
+ in->valid = 1;
+ in->variantType = oh->type;
+
+ in->st_mode = oh->st_mode;
+ in->st_uid = oh->st_uid;
+ in->st_gid = oh->st_gid;
+ in->st_atime = oh->st_atime;
+ in->st_mtime = oh->st_mtime;
+ in->st_ctime = oh->st_ctime;
+ in->chunkId = chunk;
+
+ in->sum = oh->sum;
+ in->dirty = 0;
+
+ // directory stuff...
+ // hook up to parent
+
+ parent = yaffs_FindOrCreateObjectByNumber(dev,oh->parentObjectId,YAFFS_OBJECT_TYPE_DIRECTORY);
+ if(parent->variantType == YAFFS_OBJECT_TYPE_UNKNOWN)
+ {
+ // Set up as a directory
+ parent->variantType = YAFFS_OBJECT_TYPE_DIRECTORY;
+ INIT_LIST_HEAD(&parent->variant.directoryVariant.children);
+ }
+ else if(parent->variantType != YAFFS_OBJECT_TYPE_DIRECTORY)
+ {
+ // Hoosterman, another problem....
+ // We're trying to use a non-directory as a directory
+ // Todo ... handle
+ }
+
+ yaffs_AddObjectToDirectory(parent,in);
+
+ // Note re hardlinks.
+ // Since we might scan a hardlink before its equivalent object is scanned
+ // we put them all in a list.
+ // After scanning is complete, we should have all the objects, so we run through this
+ // list and fix up all the chains.
+
+ switch(in->variantType)
+ {
+ case YAFFS_OBJECT_TYPE_UNKNOWN: // Todo got a problem
+ break;
+ case YAFFS_OBJECT_TYPE_FILE:
+ in->variant.fileVariant.fileSize = oh->fileSize;
+ break;
+ case YAFFS_OBJECT_TYPE_HARDLINK:
+ in->variant.hardLinkVariant.equivalentObjectId = oh->equivalentObjectId;
+ (yaffs_Object *)(in->hardLinks.next) = hardList;
+ hardList = in;
+ break;
+ case YAFFS_OBJECT_TYPE_DIRECTORY: // Do nothing
+ break;
+ case YAFFS_OBJECT_TYPE_SYMLINK: // Do nothing
+ in->variant.symLinkVariant.alias = yaffs_CloneString(oh->alias);
+ break;
+ }
+ T((" %d %d header %d \"%s\" type %d\n",blk,c,tags.objectId,oh->name,in->variantType));
+ }
+ }
+ else
+ {
+ // it's a bad block
+ state = YAFFS_BLOCK_STATE_DEAD;
+ }
+ }
+
+ if(state == YAFFS_BLOCK_STATE_UNKNOWN)
+ {
+ // If we got this far, then the block is fully allocated.
+ // ie. Full or Dirty
+ state = (inuse) ? YAFFS_BLOCK_STATE_FULL : YAFFS_BLOCK_STATE_DIRTY;
+
+ }
+
+ dev->blockInfo[blk].pageBits = pageBits;
+ dev->blockInfo[blk].pagesInUse = inuse;
+ dev->blockInfo[blk].blockState = state;
+
+ }
+
+ // Todo fix up the hard link chains
+ while(hardList)
+ {
+ hl = hardList;
+ hardList = (yaffs_Object *)(hardList->hardLinks.next);
+
+ in = yaffs_FindObjectByNumber(dev,hl->variant.hardLinkVariant.equivalentObjectId);
+
+ if(in)
+ {
+ hl->variant.hardLinkVariant.equivalentObject=in;
+ list_add(&hl->hardLinks,&in->hardLinks);
+ }
+ else
+ {
+ //Todo Need to report this better.
+ hl->variant.hardLinkVariant.equivalentObject=NULL;
+ INIT_LIST_HEAD(&hl->hardLinks);
+
+ }
+
+ }
+
+
+
+ return YAFFS_OK;
+}
+
+
+////////////////////////// Directory Functions /////////////////////////
+
+
+static void yaffs_AddObjectToDirectory(yaffs_Object *directory, yaffs_Object *obj)
+{
+
+ if(obj->siblings.prev == NULL)
+ {
+ // Not initialised
+ INIT_LIST_HEAD(&obj->siblings);
+
+ }
+ else if(!list_empty(&obj->siblings))
+ {
+ // If it is holed up somewhere else, un hook it
+ list_del_init(&obj->siblings);
+ }
+ // Now add it
+ list_add(&obj->siblings,&directory->variant.directoryVariant.children);
+ obj->parent = directory;
+}
+
+static void yaffs_RemoveObjectFromDirectory(yaffs_Object *obj)
+{
+ list_del_init(&obj->siblings);
+ obj->parent = NULL;
+}
+
+yaffs_Object *yaffs_FindObjectByName(yaffs_Object *directory,const char *name)
+{
+ int sum;
+
+ struct list_head *i;
+ __u8 buffer[YAFFS_BYTES_PER_CHUNK];
+ yaffs_ObjectHeader *oh = (yaffs_ObjectHeader *)buffer;
+
+ yaffs_Object *l;
+
+ sum = yaffs_CalcNameSum(name);
+
+ list_for_each(i,&directory->variant.directoryVariant.children)
+ {
+ l = list_entry(i, yaffs_Object,siblings);
+
+ // Special case for lost-n-found
+ if(l->objectId == YAFFS_OBJECTID_LOSTNFOUND)
+ {
+ if(strcmp(name,YAFFS_LOSTNFOUND_NAME) == 0)
+ {
+ return l;
+ }
+ }
+ else if(l->sum == sum)
+ {
+ // Do a real check
+ yaffs_ReadChunkFromNAND(l->myDev,l->chunkId,buffer,NULL);
+ if(strcmp(name,oh->name) == 0)
+ {
+ return l;
+ }
+
+
+ }
+ }
+
+ return NULL;
+}
+
+
+int yaffs_ApplyToDirectoryChildren(yaffs_Object *theDir,int (*fn)(yaffs_Object *))
+{
+ struct list_head *i;
+ yaffs_Object *l;
+
+
+ list_for_each(i,&theDir->variant.directoryVariant.children)
+ {
+ l = list_entry(i, yaffs_Object,siblings);
+ if(!fn(l))
+ {
+ return YAFFS_FAIL;
+ }
+ }
+
+ return YAFFS_OK;
+
+}
+
+
+// GetEquivalentObject dereferences any hard links to get to the
+// actual object.
+
+static yaffs_Object *yaffs_GetEquivalentObject(yaffs_Object *obj)
+{
+ if(obj && obj->variantType == YAFFS_OBJECT_TYPE_HARDLINK)
+ {
+ // We want the object id of the equivalent object, not this one
+ obj = obj->variant.hardLinkVariant.equivalentObject;
+ }
+ return obj;
+
+}
+
+int yaffs_GetObjectName(yaffs_Object *obj,char *name,int buffSize)
+{
+ memset(name,0,buffSize);
+
+ if(obj->objectId == YAFFS_OBJECTID_LOSTNFOUND)
+ {
+ strncpy(name,YAFFS_LOSTNFOUND_NAME,buffSize - 1);
+ }
+ else
+ {
+ __u8 buffer[YAFFS_BYTES_PER_CHUNK];
+ yaffs_ObjectHeader *oh = (yaffs_ObjectHeader *)buffer;
+
+ memset(buffer,0,YAFFS_BYTES_PER_CHUNK);
+
+ if(obj->chunkId >= 0)
+ {
+ yaffs_ReadChunkFromNAND(obj->myDev,obj->chunkId,buffer,NULL);
+ }
+ strncpy(name,oh->name,buffSize - 1);
+ }
+
+ return strlen(name);
+}
+
+int yaffs_GetObjectFileLength(yaffs_Object *obj)
+{
+
+ // Dereference any hard linking
+ obj = yaffs_GetEquivalentObject(obj);
+
+ if(obj->variantType == YAFFS_OBJECT_TYPE_FILE)
+ {
+ return obj->variant.fileVariant.fileSize;
+ }
+ if(obj->variantType == YAFFS_OBJECT_TYPE_SYMLINK)
+ {
+ return strlen(obj->variant.symLinkVariant.alias);
+ }
+ else
+ {
+ // Only a directory should drop through to here
+ return YAFFS_BYTES_PER_CHUNK;
+ }
+}
+
+int yaffs_GetObjectLinkCount(yaffs_Object *obj)
+{
+ int count = 1; // the object itself
+ struct list_head *i;
+
+ list_for_each(i,&obj->hardLinks)
+ {
+ count++;
+ }
+ return count;
+
+}
+
+
+int yaffs_GetObjectInode(yaffs_Object *obj)
+{
+ obj = yaffs_GetEquivalentObject(obj);
+
+ return obj->objectId;
+}
+
+unsigned yaffs_GetObjectType(yaffs_Object *obj)
+{
+ obj = yaffs_GetEquivalentObject(obj);
+
+ switch(obj->variantType)
+ {
+ case YAFFS_OBJECT_TYPE_FILE: return DT_REG; break;
+ case YAFFS_OBJECT_TYPE_DIRECTORY: return DT_DIR; break;
+ case YAFFS_OBJECT_TYPE_SYMLINK: return DT_LNK; break;
+ case YAFFS_OBJECT_TYPE_HARDLINK: return DT_REG; break;
+ default: return DT_REG; break;
+ }
+}
+
+char *yaffs_GetSymlinkAlias(yaffs_Object *obj)
+{
+ obj = yaffs_GetEquivalentObject(obj);
+ if(obj->variantType == YAFFS_OBJECT_TYPE_SYMLINK)
+ {
+ return yaffs_CloneString(obj->variant.symLinkVariant.alias);
+ }
+ else
+ {
+ return yaffs_CloneString("");
+ }
+}
+
+
+int yaffs_SetAttributes(yaffs_Object *obj, struct iattr *attr)
+{
+ unsigned int valid = attr->ia_valid;
+
+ if(valid & ATTR_MODE) obj->st_mode = attr->ia_mode;
+ if(valid & ATTR_UID) obj->st_uid = attr->ia_uid;
+ if(valid & ATTR_GID) obj->st_gid = attr->ia_gid;
+
+ if(valid & ATTR_ATIME) obj->st_atime = attr->ia_atime;
+ if(valid & ATTR_CTIME) obj->st_ctime = attr->ia_ctime;
+ if(valid & ATTR_MTIME) obj->st_mtime = attr->ia_mtime;
+
+ if(valid & ATTR_SIZE) yaffs_ResizeFile(obj,attr->ia_size);
+
+ yaffs_UpdateObjectHeader(obj,NULL);
+
+ return YAFFS_OK;
+
+}
+int yaffs_GetAttributes(yaffs_Object *obj, struct iattr *attr)
+{
+ unsigned int valid = 0;
+
+ attr->ia_mode = obj->st_mode; valid |= ATTR_MODE;
+ attr->ia_uid = obj->st_uid; valid |= ATTR_UID;
+ attr->ia_gid = obj->st_gid; valid |= ATTR_GID;
+
+ attr->ia_atime = obj->st_atime; valid |= ATTR_ATIME;
+ attr->ia_ctime = obj->st_ctime; valid |= ATTR_CTIME;
+ attr->ia_mtime = obj->st_mtime; valid |= ATTR_MTIME;
+
+ attr->ia_size = yaffs_GetFileSize(obj); valid |= ATTR_SIZE;
+
+ attr->ia_valid = valid;
+
+ return YAFFS_OK;
+
+}
+
+
+
+int yaffs_DumpObject(yaffs_Object *obj)
+{
+ __u8 buffer[YAFFS_BYTES_PER_CHUNK];
+ char name[256];
+// yaffs_ObjectHeader *oh = (yaffs_ObjectHeader *)buffer;
+
+ memset(buffer,0,YAFFS_BYTES_PER_CHUNK);
+
+ if(obj->chunkId >= 0)
+ {
+ yaffs_ReadChunkFromNAND(obj->myDev,obj->chunkId,buffer,NULL);
+ }
+
+ yaffs_GetObjectName(obj,name,256);
+
+ YPRINTF(("Object %d \"%s\"\n dirty %d valid %d serial %d sum %d chunk %d type %d size %d\n",
+ yaffs_GetObjectInode(obj), name, obj->dirty, obj->valid, obj->serial,
+ obj->sum, obj->chunkId, yaffs_GetObjectType(obj), yaffs_GetObjectFileLength(obj)));
+
+#if 0
+ YPRINTF(("Object %d \"%s\"\n dirty %d valid %d serial %d sum %d chunk %d\n",
+ obj->objectId, oh->name, obj->dirty, obj->valid, obj->serial,
+ obj->sum, obj->chunkId));
+ switch(obj->variantType)
+ {
+ case YAFFS_OBJECT_TYPE_FILE:
+ YPRINTF((" FILE length %d\n",obj->variant.fileVariant.fileSize));
+ break;
+ case YAFFS_OBJECT_TYPE_DIRECTORY:
+ YPRINTF((" DIRECTORY\n"));
+ break;
+ case YAFFS_OBJECT_TYPE_HARDLINK: //todo
+ case YAFFS_OBJECT_TYPE_SYMLINK:
+ case YAFFS_OBJECT_TYPE_UNKNOWN:
+ default:
+ }
+#endif
+
+ return YAFFS_OK;
+}
+
+
+///////////////////////// Initialisation code ///////////////////////////
+
+
+
+int yaffs_GutsInitialise(yaffs_Device *dev)
+{
+ unsigned nChunks,x;
+ int bits;
+
+
+ dev = dev;
+
+ if(!yaffs_CheckStructures())
+ {
+ return YAFFS_FAIL;
+ }
+
+
+ // OK now calculate a few things for the device
+ // Calculate chunkGroupBits.
+ // If there are 64k or less chunks then this is 1
+ // Else it is log2(nChunks) - 16
+ //
+ x = nChunks = YAFFS_CHUNKS_PER_BLOCK * dev->nBlocks;
+
+ for(bits = 0, x = nChunks; (x & 1) == 0; bits++)
+ {
+ x >>= 1;
+ }
+
+ if( x != 1)
+ {
+ // Not a power of 2
+ YPRINTF(("nBlocks should be a power of 2 but is %u\n",
+ dev->nBlocks));
+ return YAFFS_FAIL;
+ }
+
+ if(bits <= 16)
+ {
+ dev->chunkGroupBits = 0;
+ dev->chunkGroupSize = 1;
+ }
+ else
+ {
+ dev->chunkGroupBits = bits - 16;
+ dev->chunkGroupSize = nChunks/0x10000;
+ }
+
+ // More device initialisation
+ dev->garbageCollectionRequired = 0;
+ dev->currentDirtyChecker = 0;
+
+ yaffs_InitialiseBlocks(dev);
+
+ yaffs_InitialiseTnodes(dev);
+
+ yaffs_InitialiseObjects(dev);
+
+
+ // Initialise the root and lost and found directories
+ dev->lostNFoundDir = dev->rootDir = NULL;
+ dev->rootDir = yaffs_CreateFakeDirectory(dev,YAFFS_OBJECTID_ROOT,YAFFS_ROOT_MODE | S_IFDIR);
+ dev->lostNFoundDir = yaffs_CreateFakeDirectory(dev,YAFFS_OBJECTID_LOSTNFOUND,YAFFS_ROOT_MODE | S_IFDIR);
+ yaffs_AddObjectToDirectory(dev->rootDir,dev->lostNFoundDir);
+
+ // Now scan the flash.
+ yaffs_Scan(dev);
+
+
+ return YAFFS_OK;
+
+}
+
+void yaffs_Deinitialise(yaffs_Device *dev)
+{
+ yaffs_DeinitialiseBlocks(dev);
+ yaffs_DeinitialiseTnodes(dev);
+ yaffs_DeinitialiseObjects(dev);
+
+}
+
+int yaffs_GetNumberOfFreeChunks(yaffs_Device *dev)
+{
+ int nFree = dev->nFreeChunks - (YAFFS_CHUNKS_PER_BLOCK * YAFFS_RESERVED_BLOCKS);
+
+ return (nFree < 0) ? 0 : nFree;
+
+}
+
+
+/////////////////// YAFFS test code //////////////////////////////////
+
+#define yaffs_CheckStruct(structure,syze, name) \
+ if(sizeof(structure) != syze) \
+ { YPRINTF(("%s should be %d but is %d\n",name,syze,sizeof(structure))); \
+ return YAFFS_FAIL; \
+ }
+
+
+static int yaffs_CheckStructures(void)
+{
+ yaffs_CheckStruct(yaffs_Tags,8,"yaffs_Tags")
+ yaffs_CheckStruct(yaffs_TagsUnion,8,"yaffs_TagsUnion")
+ yaffs_CheckStruct(yaffs_Spare,16,"yaffs_Spare")
+ yaffs_CheckStruct(yaffs_Tnode,2* YAFFS_NTNODES_LEVEL0,"yaffs_Tnode")
+ yaffs_CheckStruct(yaffs_ObjectHeader,512,"yaffs_ObjectHeader")
+
+
+ return YAFFS_OK;
+}
+
+void yaffs_GutsTest(yaffs_Device *dev)
+{
+
+ if(yaffs_CheckStructures() != YAFFS_OK)
+ {
+ YPRINTF(("One or more structures malformed-- aborting\n"));
+ }
+ else
+ {
+ YPRINTF(("Structures OK\n"));
+ }
+
+ yaffs_TnodeTest(dev);
+ yaffs_ObjectTest(dev);
+}
+
+
--- /dev/null
+/*
+ * YAFFS: Yet another FFS. A NAND-flash specific file system.
+ * yaffs_guts.h: Configuration etc for yaffs_guts
+ *
+ * Copyright (C) 2002 Aleph One Ltd.
+ * for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#ifndef __YAFFS_GUTS_H__
+#define __YAFFS_GUTS_H__
+
+#include "devextras.h"
+
+
+#define YAFFS_OK 1
+#define YAFFS_FAIL 0
+
+// Y=0x59, A=0x41, S=0x53
+#define YAFFS_MAGIC 0x5941FF53
+
+#define YAFFS_NTNODES_LEVEL0 16
+#define YAFFS_TNODES_LEVEL0_BITS 4
+#define YAFFS_TNODES_LEVEL0_MASK 0xf
+
+#define YAFFS_NTNODES_INTERNAL (YAFFS_NTNODES_LEVEL0 / 2)
+#define YAFFS_TNODES_INTERNAL_BITS (YAFFS_TNODES_LEVEL0_BITS - 1)
+#define YAFFS_TNODES_INTERNAL_MASK 0x7
+#define YAFFS_TNODES_MAX_LEVEL 6
+
+#define YAFFS_BYTES_PER_CHUNK 512
+#define YAFFS_CHUNK_SIZE_SHIFT 9
+
+#define YAFFS_BYTES_PER_SPARE 16
+
+#define YAFFS_CHUNKS_PER_BLOCK 32
+#define YAFFS_BYTES_PER_BLOCK (YAFFS_CHUNKS_PER_BLOCK*YAFFS_BYTES_PER_CHUNK)
+
+#define YAFFS_MAX_CHUNK_ID 0x000FFFFF
+
+#define YAFFS_UNUSED_OBJECT_ID 0x0003FFFF
+
+#define YAFFS_ALLOCATION_NOBJECTS 100
+#define YAFFS_ALLOCATION_NTNODES 100
+#define YAFFS_ALLOCATION_NLINKS 100
+
+#define YAFFS_NOBJECT_BUCKETS 256
+
+
+#define YAFFS_RESERVED_BLOCKS 5
+
+#define YAFFS_OBJECT_SPACE 0x40000
+#define YAFFS_MAX_NAME_LENGTH 255
+
+#define YAFFS_MAX_ALIAS_LENGTH 211
+
+#define YAFFS_OBJECTID_ROOT 1
+#define YAFFS_ROOT_MODE 0666
+#define YAFFS_OBJECTID_LOSTNFOUND 2
+#define YAFFS_LOSTNFOUND_NAME "lost+found"
+
+// Tags structures in RAM
+// NB This uses bitfield. Bitfields should not stradle a u32 boundary otherwise
+// the structure size will get blown out.
+
+typedef struct
+{
+ unsigned chunkId:20;
+ unsigned serialNumber:2;
+ unsigned byteCount:10;
+ unsigned objectId:18;
+ unsigned ecc:12;
+ unsigned unusedStuff:2;
+} yaffs_Tags;
+
+typedef union
+{
+ yaffs_Tags asTags;
+ __u8 asBytes[8];
+} yaffs_TagsUnion;
+
+
+// Spare structure
+typedef struct
+{
+ __u8 tagByte0;
+ __u8 tagByte1;
+ __u8 tagByte2;
+ __u8 tagByte3;
+ __u8 pageStatus;
+ __u8 blockStatus;
+ __u8 tagByte4;
+ __u8 tagByte5;
+ __u8 ecc1[3];
+ __u8 tagByte6;
+ __u8 tagByte7;
+ __u8 ecc2[3];
+} yaffs_Spare;
+
+// Block data in RAM
+
+typedef enum {
+ YAFFS_BLOCK_STATE_UNKNOWN = 0,
+
+ YAFFS_BLOCK_STATE_EMPTY, // This block is empty
+
+ YAFFS_BLOCK_STATE_ALLOCATING, // This block is partially allocated.
+ // This is the one currently being used for page
+ // allocation. Should never be more than one of these
+
+
+ YAFFS_BLOCK_STATE_FULL, // All the pages in this block have been allocated.
+ // At least one page holds valid data.
+
+ YAFFS_BLOCK_STATE_DIRTY, // All pages have been allocated and deleted.
+ // Erase me, reuse me.
+
+ YAFFS_BLOCK_STATE_DEAD = 0x99 // This block has failed and is not in use
+
+} yaffs_BlockState;
+
+
+
+
+typedef struct
+{
+ __u32 pageBits; // bitmap of pages in use
+ __u8 blockState; // One of the above block states
+ __u8 pagesInUse; // number of pages in use
+} yaffs_BlockInfo;
+
+
+//////////////////// Object structure ///////////////////////////
+// This is the object structure as stored on NAND
+
+typedef enum
+{
+ YAFFS_OBJECT_TYPE_UNKNOWN,
+ YAFFS_OBJECT_TYPE_FILE,
+ YAFFS_OBJECT_TYPE_SYMLINK,
+ YAFFS_OBJECT_TYPE_DIRECTORY,
+ YAFFS_OBJECT_TYPE_HARDLINK
+} yaffs_ObjectType;
+
+typedef struct
+{
+ yaffs_ObjectType type;
+
+ // Apply to everything
+ int parentObjectId;
+ __u16 sum; // checksum of name
+ char name[YAFFS_MAX_NAME_LENGTH + 1];
+
+ // Thes following apply to directories, files, symlinks - not hard links
+ __u32 st_mode; // protection
+ __u32 st_uid; // user ID of owner
+ __u32 st_gid; // group ID of owner
+ __u32 st_atime; // time of last access
+ __u32 st_mtime; // time of last modification
+ __u32 st_ctime; // time of last change
+
+ // File size applies to files only
+ int fileSize;
+
+ // Equivalent object id applies to hard links only.
+ int equivalentObjectId;
+ char alias[YAFFS_MAX_ALIAS_LENGTH + 1];
+
+
+} yaffs_ObjectHeader;
+
+
+
+//////////////////// Tnode ///////////////////////////
+
+union yaffs_Tnode_union
+{
+ union yaffs_Tnode_union *internal[YAFFS_NTNODES_INTERNAL];
+ __u16 level0[YAFFS_NTNODES_LEVEL0];
+
+};
+
+typedef union yaffs_Tnode_union yaffs_Tnode;
+
+struct yaffs_TnodeList_struct
+{
+ struct yaffs_TnodeList_struct *next;
+ yaffs_Tnode *tnodes;
+};
+
+typedef struct yaffs_TnodeList_struct yaffs_TnodeList;
+
+
+
+/////////////////// Object ////////////////////////////////
+// An object can be one of:
+// - a directory (no data, has children links
+// - a regular file (data.... not prunes :->).
+// - a symlink [symbolic link] (the alias).
+// - a hard link
+
+
+typedef struct
+{
+ __u32 fileSize;
+ __u32 topLevel;
+ yaffs_Tnode *top;
+} yaffs_FileStructure;
+
+typedef struct
+{
+ struct list_head children; // list of child links
+} yaffs_DirectoryStructure;
+
+typedef struct
+{
+ char *alias;
+} yaffs_SymLinkStructure;
+
+typedef struct
+{
+ struct yaffs_ObjectStruct *equivalentObject;
+ __u32 equivalentObjectId;
+} yaffs_HardLinkStructure;
+
+typedef union
+{
+ yaffs_FileStructure fileVariant;
+ yaffs_DirectoryStructure directoryVariant;
+ yaffs_SymLinkStructure symLinkVariant;
+ yaffs_HardLinkStructure hardLinkVariant;
+} yaffs_ObjectVariant;
+
+
+struct yaffs_ObjectStruct
+{
+ __u8 fake:1; // A fake object has no presence on NAND.
+ __u8 renameAllowed:1;
+ __u8 unlinkAllowed:1;
+ __u8 dirty:1; // the object needs to be written to flash
+ __u8 valid:1; // When the file system is being loaded up, this
+ // object might be created before the data
+ // is available (ie. file data records appear before the header).
+ __u8 serial; // serial number of chunk in NAND. Store here so we don't have to
+ // read back the old one to update.
+ __u16 sum; // sum of the name to speed searching
+
+ struct yaffs_DeviceStruct *myDev; // The device I'm on
+
+
+ struct list_head hashLink; // list of objects in this hash bucket
+
+
+ struct list_head hardLinks; // all the equivalent hard linked objects
+ // live on this list
+ // directory structure stuff
+ struct yaffs_ObjectStruct *parent; //my parent directory
+ struct list_head siblings; // siblings in a directory
+ // also used for linking up the free list
+
+ // Where's my data in NAND?
+ int chunkId; // where it lives
+
+ __u32 objectId; // the object id value
+
+
+ __u32 st_mode; // protection
+ __u32 st_uid; // user ID of owner
+ __u32 st_gid; // group ID of owner
+ __u32 st_atime; // time of last access
+ __u32 st_mtime; // time of last modification
+ __u32 st_ctime; // time of last change
+
+
+ yaffs_ObjectType variantType;
+
+ yaffs_ObjectVariant variant;
+
+};
+
+
+
+typedef struct yaffs_ObjectStruct yaffs_Object;
+
+
+struct yaffs_ObjectList_struct
+{
+ yaffs_Object *objects;
+ struct yaffs_ObjectList_struct *next;
+};
+
+typedef struct yaffs_ObjectList_struct yaffs_ObjectList;
+
+typedef struct
+{
+ struct list_head list;
+ __u32 count;
+} yaffs_ObjectBucket;
+
+
+//////////////////// Device ////////////////////////////////
+
+struct yaffs_DeviceStruct
+{
+ // Entry parameters set up way early. Yaffs sets up the rest.
+ __u32 nBlocks; // Size of whole device in blocks
+ __u32 startBlock; // Start block we're allowed to use
+ __u32 endBlock; // End block we're allowed to use
+ __u16 chunkGroupBits; // 0 for devices <= 32MB. else log2(nchunks) - 16
+ __u16 chunkGroupSize; // == 2^^chunkGroupBits
+
+
+ void *genericDevice; // Pointer to device context
+ // On an mtd this holds the mtd pointer.
+ struct semaphore sem;// Semaphore for waiting on erasure.
+
+
+ // NAND access functions (Must be set before calling YAFFS)
+
+ int (*writeChunkToNAND)(struct yaffs_DeviceStruct *dev,int chunkInNAND, const __u8 *data, yaffs_Spare *spare);
+ int (*readChunkFromNAND)(struct yaffs_DeviceStruct *dev,int chunkInNAND, __u8 *data, yaffs_Spare *spare);
+ int (*eraseBlockInNAND)(struct yaffs_DeviceStruct *dev,int blockInNAND);
+ int (*initialiseNAND)(struct yaffs_DeviceStruct *dev);
+
+
+
+ // Runtime parameters.
+ yaffs_BlockInfo *blockInfo;
+ int nErasedBlocks;
+ int allocationBlock;
+ __u32 allocationPage;
+
+ // Runtime state
+ int nTnodesCreated;
+ yaffs_Tnode *freeTnodes;
+ int nFreeTnodes;
+ yaffs_TnodeList *allocatedTnodeList;
+
+
+ int nObjectsCreated;
+ yaffs_Object *freeObjects;
+ int nFreeObjects;
+
+ yaffs_ObjectList *allocatedObjectList;
+
+ yaffs_ObjectBucket objectBucket[YAFFS_NOBJECT_BUCKETS];
+
+ int nFreeChunks;
+
+ int currentDirtyChecker; // Used to find current dirtiest block
+
+ int garbageCollectionRequired;
+
+ yaffs_Object *rootDir;
+ yaffs_Object *lostNFoundDir;
+
+
+};
+
+ typedef struct yaffs_DeviceStruct yaffs_Device;
+
+
+
+//////////// YAFFS Functions //////////////////
+
+int yaffs_GutsInitialise(yaffs_Device *dev);
+void yaffs_Deinitialise(yaffs_Device *dev);
+
+int yaffs_GetNumberOfFreeChunks(yaffs_Device *dev);
+
+
+// Rename
+int yaffs_RenameObject(yaffs_Object *oldDir, const char *oldName, yaffs_Object *newDir, const char *newName);
+
+// generic Object functions
+int yaffs_Unlink(yaffs_Object *dir, const char *name);
+
+// Object access functions.
+int yaffs_GetObjectName(yaffs_Object *obj,char *name,int buffSize);
+int yaffs_GetObjectFileLength(yaffs_Object *obj);
+int yaffs_GetObjectInode(yaffs_Object *obj);
+unsigned yaffs_GetObjectType(yaffs_Object *obj);
+int yaffs_GetObjectLinkCount(yaffs_Object *obj);
+
+// Change inode attributes
+int yaffs_SetAttributes(yaffs_Object *obj, struct iattr *attr);
+int yaffs_GetAttributes(yaffs_Object *obj, struct iattr *attr);
+
+// File operations
+int yaffs_ReadDataFromFile(yaffs_Object *obj, __u8 *buffer, __u32 offset, int nBytes);
+int yaffs_WriteDataToFile(yaffs_Object *obj, const __u8 *buffer, __u32 offset, int nBytes);
+int yaffs_ResizeFile(yaffs_Object *obj, int newSize);
+
+yaffs_Object *yaffs_MknodFile(yaffs_Object *parent,const char *name, __u32 mode, __u32 uid, __u32 gid);
+int yaffs_FlushFile(yaffs_Object *obj);
+
+
+// Directory operations
+yaffs_Object *yaffs_MknodDirectory(yaffs_Object *parent,const char *name, __u32 mode, __u32 uid, __u32 gid);
+yaffs_Object *yaffs_FindObjectByName(yaffs_Object *theDir,const char *name);
+int yaffs_ApplyToDirectoryChildren(yaffs_Object *theDir,int (*fn)(yaffs_Object *));
+
+yaffs_Object *yaffs_FindObjectByNumber(yaffs_Device *dev,int number);
+
+// Link operations
+yaffs_Object *yaffs_Link(yaffs_Object *parent, const char *name, yaffs_Object *equivalentObject);
+
+// Symlink operations
+yaffs_Object *yaffs_MknodSymLink(yaffs_Object *parent, const char *name, __u32 mode, __u32 uid, __u32 gid, const char *alias);
+char *yaffs_GetSymlinkAlias(yaffs_Object *obj);
+
+
+// Special directories
+yaffs_Object *yaffs_Root(yaffs_Device *dev);
+yaffs_Object *yaffs_LostNFound(yaffs_Device *dev);
+
+
+// Debug dump
+int yaffs_DumpObject(yaffs_Object *obj);
+
+
+void yaffs_GutsTest(yaffs_Device *dev);
+
+
+#endif
--- /dev/null
+/*
+ * YAFFS: Yet another FFS. A NAND-flash specific file system.
+ * yaffs_mtdif.c NAND mtd wrapper functions.
+ *
+ * Copyright (C) 2002 Aleph One Ltd.
+ * for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+ #ifdef YAFFS_MTD_ENABLED
+
+#include "yportenv.h"
+
+#include "yaffs_mtdif.h"
+
+#include "linux/mtd/mtd.h"
+#include "linux/types.h"
+
+
+int nandmtd_WriteChunkToNAND(yaffs_Device *dev,int chunkInNAND,const __u8 *data, yaffs_Spare *spare)
+{
+ struct mtd_info *mtd = (struct mtd_info *)(dev->genericDevice);
+ size_t dummy;
+
+ loff_t addr = ((loff_t)chunkInNAND) * YAFFS_BYTES_PER_CHUNK;
+
+
+ __u8 *spareAsBytes = (__u8 *)spare;
+
+ if(data)
+ mtd->write(mtd,addr,YAFFS_BYTES_PER_CHUNK,&dummy,data);
+ if(spare)
+ mtd->write_oob(mtd,addr,YAFFS_BYTES_PER_SPARE,&dummy,spareAsBytes);
+
+ return YAFFS_OK;
+}
+
+
+int nandmtd_ReadChunkFromNAND(yaffs_Device *dev,int chunkInNAND, __u8 *data, yaffs_Spare *spare)
+{
+ struct mtd_info *mtd = (struct mtd_info *)(dev->genericDevice);
+ size_t dummy;
+
+ loff_t addr = ((loff_t)chunkInNAND) * YAFFS_BYTES_PER_CHUNK;
+
+ __u8 *spareAsBytes = (__u8 *)spare;
+
+ if(data)
+ mtd->read(mtd,addr,YAFFS_BYTES_PER_CHUNK,&dummy,data);
+ if(spare)
+ mtd->read_oob(mtd,addr,YAFFS_BYTES_PER_SPARE,&dummy,spareAsBytes);
+
+ return YAFFS_OK;
+}
+
+
+static void nandmtd_EraseCallback(struct erase_info *ei)
+{
+ yaffs_Device *dev = (yaffs_Device *)ei->priv;
+ up(&dev->sem);
+}
+
+
+int nandmtd_EraseBlockInNAND(yaffs_Device *dev, int blockNumber)
+{
+
+ struct mtd_info *mtd = (struct mtd_info *)(dev->genericDevice);
+ __u32 addr = ((loff_t) blockNumber) * YAFFS_BYTES_PER_BLOCK;
+ struct erase_info ei;
+
+ ei.mtd = mtd;
+ ei.addr = addr;
+ ei.len = YAFFS_BYTES_PER_BLOCK;
+ ei.time = 1000;
+ ei.retries = 2;
+ ei.callback = nandmtd_EraseCallback;
+ ei.priv = (u_long)dev;
+
+ // Todo finish off the ei if required
+
+ sema_init(&dev->sem,0);
+
+ mtd->erase(mtd,&ei);
+
+
+ down(&dev->sem); // Wait for the erasure to complete
+
+ //Todo, check result of erasure
+
+ return YAFFS_OK;
+}
+
+int nandmtd_InitialiseNAND(yaffs_Device *dev)
+{
+ return YAFFS_OK;
+}
+
+#endif // YAFFS_MTD_ENABLED
+
--- /dev/null
+/*
+ * YAFFS: Yet another FFS. A NAND-flash specific file system.
+ * yaffs_mtdif.h NAND mtd interface wrappers
+ *
+ * Copyright (C) 2002 Aleph One Ltd.
+ * for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#ifndef __YAFFS_MTDIF_H__
+#define __YAFFS_MTDIF_H__
+
+#include "yaffs_guts.h"
+
+int nandmtd_WriteChunkToNAND(yaffs_Device *dev,int chunkInNAND,const __u8 *data, yaffs_Spare *spare);
+int nandmtd_ReadChunkFromNAND(yaffs_Device *dev,int chunkInNAND, __u8 *data, yaffs_Spare *spare);
+int nandmtd_EraseBlockInNAND(yaffs_Device *dev, int blockNumber);
+int nandmtd_InitialiseNAND(yaffs_Device *dev);
+#endif
+
+
+
+
--- /dev/null
+/*
+ * YAFFS: Yet another FFS. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002 Aleph One Ltd.
+ * for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * yaffs_nandemul.h: Interface to emulated NAND functions
+ *
+ */
+
+#ifndef __YAFFS_NANDEMUL_H__
+#define __YAFFS_NANDEMUL_H__
+
+#include "yaffs_guts.h"
+
+
+/* WriteChunkToNAND and ReadChunkFromNAND are used with two pointers.
+ * If either of these pointers are null, then that field will not be
+ * transferred.
+ */
+
+int nandemul_WriteChunkToNAND(struct yaffs_DeviceStruct *dev,int chunkInNAND, const __u8 *data, yaffs_Spare *spare);
+int nandemul_ReadChunkFromNAND(struct yaffs_DeviceStruct *dev,int chunkInNAND, __u8 *data, yaffs_Spare *spare);
+int nandemul_EraseBlockInNAND(struct yaffs_DeviceStruct *dev,int blockInNAND);
+int nandemul_InitialiseNAND(struct yaffs_DeviceStruct *dev);
+
+#endif
+
--- /dev/null
+/*
+ * YAFFS: Yet another FFS. A NAND-flash specific file system.
+ * yaffs_ramem.c NAND emulation on top of a chunk of RAM
+ *
+ * Copyright (C) 2002 Aleph One Ltd.
+ * for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+ //yaffs_ramem.c
+ // Since this creates the RAM block at start up it is pretty useless for testing the scanner.
+
+#ifdef YAFFS_RAM_ENABLED
+
+#include "yportenv.h"
+
+#include "yaffs_nandemul.h"
+#include "yaffs_guts.h"
+#include "yaffsinterface.h"
+#include "devextras.h"
+
+
+#define EM_SIZE_IN_MEG 2
+
+#define BLOCK_SIZE (32 * 528)
+#define BLOCKS_PER_MEG ((1024*1024)/(32 * 512))
+#define FILE_SIZE_IN_BLOCKS (FILE_SIZE_IN_MEG * BLOCKS_PER_MEG)
+#define FILE_SIZE_IN_BYTES (FILE_SIZE_IN_BLOCKS * BLOCK_SIZE)
+
+#define T(x) YPRINTF(x)
+
+#define DEFAULT_SIZE_IN_MB 2
+
+typedef struct
+{
+ __u8 data[528]; // Data + spare
+ int count[3]; // The programming count for each area of
+ // the page (0..255,256..511,512..527
+ int empty; // is this empty?
+} nandemul_Page;
+
+typedef struct
+{
+ nandemul_Page page[32]; // The pages in the block
+ __u8 damaged; // Is the block damaged?
+
+} nandemul_Block;
+
+
+
+typedef struct
+{
+ nandemul_Block **block;
+ int nBlocks;
+} nandemul_Device;
+
+static nandemul_Device ned;
+
+int sizeInMB = DEFAULT_SIZE_IN_MB;
+
+
+static void nandemul_ReallyEraseBlock(int blockNumber)
+{
+ int i;
+
+ nandemul_Block *theBlock = ned.block[blockNumber];
+
+ for(i = 0; i < 32; i++)
+ {
+ memset(theBlock->page[i].data,0xff,528);
+ theBlock->page[i].count[0] = 0;
+ theBlock->page[i].count[1] = 0;
+ theBlock->page[i].count[2] = 0;
+ theBlock->page[i].empty = 1;
+ }
+
+}
+
+
+int nandemul_CalcNBlocks(void)
+{
+ switch(sizeInMB)
+ {
+ case 8:
+ case 16:
+ case 32:
+ case 64:
+ case 128:
+ case 256:
+ case 512:
+ break;
+ default:
+ sizeInMB = DEFAULT_SIZE_IN_MB;
+ }
+ return sizeInMB * 64;
+}
+
+
+
+static int CheckInit(void)
+{
+ static int initialised = 0;
+
+ int i;
+ int fail = 0;
+ int nBlocks;
+ int nAllocated = 0;
+
+ if(initialised)
+ {
+ return YAFFS_OK;
+ }
+
+
+ nBlocks = nandemul_CalcNBlocks();
+
+ ned.block = YMALLOC(sizeof(nandemul_Block *) * nBlocks);
+
+ if(!ned.block) return 0;
+
+ for(i=0; i <nBlocks; i++)
+ {
+ ned.block[i] = NULL;
+ }
+
+ for(i=0; i <nBlocks && !fail; i++)
+ {
+ if((ned.block[i] = YMALLOC(sizeof(nandemul_Block))) == 0)
+ {
+ fail = 1;
+ }
+ else
+ {
+ nandemul_ReallyEraseBlock(i);
+ ned.block[i]->damaged = 0;
+ nAllocated++;
+ }
+ }
+
+ if(fail)
+ {
+ for(i = 0; i < nAllocated; i++)
+ {
+ YFREE(ned.block[i]);
+ }
+ YFREE(ned.block);
+
+ T(("Allocation failed, could only allocate %dMB of %dMB requested.\n",
+ nAllocated/64,sizeInMB));
+ return 0;
+ }
+
+ ned.nBlocks = nBlocks;
+
+ initialised = 1;
+
+ return 1;
+}
+
+int nandemul_WriteChunkToNAND(yaffs_Device *dev,int chunkInNAND,const __u8 *data, yaffs_Spare *spare)
+{
+ int blk;
+ int pg;
+ int i;
+
+ __u8 *x;
+
+ __u8 *spareAsBytes = (__u8 *)spare;
+
+
+ CheckInit();
+
+ blk = chunkInNAND/32;
+ pg = chunkInNAND%32;
+
+
+ if(data)
+ {
+ x = ned.block[blk]->page[pg].data;
+
+ for(i = 0; i < 512; i++)
+ {
+ x[i] &=data[i];
+ }
+
+ ned.block[blk]->page[pg].count[0]++;
+ ned.block[blk]->page[pg].count[1]++;
+ ned.block[blk]->page[pg].empty = 0;
+ }
+
+
+ if(spare)
+ {
+ x = &ned.block[blk]->page[pg].data[512];
+
+ for(i = 0; i < 16; i++)
+ {
+ x[i] &=spareAsBytes[i];
+ }
+ ned.block[blk]->page[pg].count[2]++;
+ }
+
+ return YAFFS_OK;
+}
+
+
+int nandemul_ReadChunkFromNAND(yaffs_Device *dev,int chunkInNAND, __u8 *data, yaffs_Spare *spare)
+{
+ int blk;
+ int pg;
+
+
+ CheckInit();
+
+ blk = chunkInNAND/32;
+ pg = chunkInNAND%32;
+
+
+ if(data)
+ {
+ memcpy(data,ned.block[blk]->page[pg].data,512);
+ }
+
+
+ if(spare)
+ {
+ memcpy(spare,&ned.block[blk]->page[pg].data[512],16);
+ }
+
+ return YAFFS_OK;
+}
+
+
+int nandemul_CheckChunkErased(yaffs_Device *dev,int chunkInNAND)
+{
+ int blk;
+ int pg;
+ int i;
+
+
+ CheckInit();
+
+ blk = chunkInNAND/32;
+ pg = chunkInNAND%32;
+
+
+ for(i = 0; i < 528; i++)
+ {
+ if(ned.block[blk]->page[pg].data[i] != 0xFF)
+ {
+ return YAFFS_FAIL;
+ }
+ }
+
+ return YAFFS_OK;
+
+}
+
+int nandemul_EraseBlockInNAND(yaffs_Device *dev, int blockNumber)
+{
+
+ CheckInit();
+
+ if(blockNumber < 0 || blockNumber >= ned.nBlocks)
+ {
+ T(("Attempt to erase non-existant block %d\n",blockNumber));
+ }
+ else if(ned.block[blockNumber]->damaged)
+ {
+ T(("Attempt to erase damaged block %d\n",blockNumber));
+ }
+ else
+ {
+ nandemul_ReallyEraseBlock(blockNumber);
+ }
+
+ return YAFFS_OK;
+}
+
+int nandemul_InitialiseNAND(yaffs_Device *dev)
+{
+ return YAFFS_OK;
+}
+
+#endif //YAFFS_RAM_ENABLED
+
--- /dev/null
+/*
+ * JFFS2 -- Journalling Flash File System, Version 2.
+ *
+ * Copyright (C) 2001 Red Hat, Inc.
+ *
+ * Created by David Woodhouse <dwmw2@cambridge.redhat.com>
+ *
+ * The original JFFS, from which the design for JFFS2 was derived,
+ * was designed and implemented by Axis Communications AB.
+ *
+ * The contents of this file are subject to the Red Hat eCos Public
+ * License Version 1.1 (the "Licence"); you may not use this file
+ * except in compliance with the Licence. You may obtain a copy of
+ * the Licence at http://www.redhat.com/
+ *
+ * Software distributed under the Licence is distributed on an "AS IS"
+ * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied.
+ * See the Licence for the specific language governing rights and
+ * limitations under the Licence.
+ *
+ * The Original Code is JFFS2 - Journalling Flash File System, version 2
+ *
+ * Alternatively, the contents of this file may be used under the
+ * terms of the GNU General Public License version 2 (the "GPL"), in
+ * which case the provisions of the GPL are applicable instead of the
+ * above. If you wish to allow the use of your version of this file
+ * only under the terms of the GPL and not to allow others to use your
+ * version of this file under the RHEPL, indicate your decision by
+ * deleting the provisions above and replace them with the notice and
+ * other provisions required by the GPL. If you do not delete the
+ * provisions above, a recipient may use your version of this file
+ * under either the RHEPL or the GPL.
+ *
+ * $Id: yaffs_super.c,v 1.1 2002-05-20 17:42:08 aleph1 Exp $
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/version.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/fs.h>
+#include <linux/jffs2.h>
+#include <linux/pagemap.h>
+#include <linux/mtd/mtd.h>
+#include <linux/interrupt.h>
+#include "nodelist.h"
+
+#ifndef MTD_BLOCK_MAJOR
+#define MTD_BLOCK_MAJOR 31
+#endif
+
+extern void jffs2_read_inode (struct inode *);
+void jffs2_put_super (struct super_block *);
+void jffs2_write_super (struct super_block *);
+static int jffs2_statfs (struct super_block *, struct statfs *);
+int jffs2_remount_fs (struct super_block *, int *, char *);
+extern void jffs2_clear_inode (struct inode *);
+
+static struct super_operations jffs2_super_operations =
+{
+ read_inode: jffs2_read_inode,
+// delete_inode: jffs2_delete_inode,
+ put_super: jffs2_put_super,
+ write_super: jffs2_write_super,
+ statfs: jffs2_statfs,
+ remount_fs: jffs2_remount_fs,
+ clear_inode: jffs2_clear_inode
+};
+
+static int jffs2_statfs(struct super_block *sb, struct statfs *buf)
+{
+ struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
+ unsigned long avail;
+
+ buf->f_type = JFFS2_SUPER_MAGIC;
+ buf->f_bsize = 1 << PAGE_SHIFT;
+ buf->f_blocks = c->flash_size >> PAGE_SHIFT;
+ buf->f_files = 0;
+ buf->f_ffree = 0;
+ buf->f_namelen = JFFS2_MAX_NAME_LEN;
+
+ spin_lock_bh(&c->erase_completion_lock);
+
+ avail = c->dirty_size + c->free_size;
+ if (avail > c->sector_size * JFFS2_RESERVED_BLOCKS_WRITE)
+ avail -= c->sector_size * JFFS2_RESERVED_BLOCKS_WRITE;
+ else
+ avail = 0;
+
+ buf->f_bavail = buf->f_bfree = avail >> PAGE_SHIFT;
+
+#if CONFIG_JFFS2_FS_DEBUG > 0
+ printk(KERN_DEBUG "STATFS:\n");
+ printk(KERN_DEBUG "flash_size: %08x\n", c->flash_size);
+ printk(KERN_DEBUG "used_size: %08x\n", c->used_size);
+ printk(KERN_DEBUG "dirty_size: %08x\n", c->dirty_size);
+ printk(KERN_DEBUG "free_size: %08x\n", c->free_size);
+ printk(KERN_DEBUG "erasing_size: %08x\n", c->erasing_size);
+ printk(KERN_DEBUG "bad_size: %08x\n", c->bad_size);
+ printk(KERN_DEBUG "sector_size: %08x\n", c->sector_size);
+
+ if (c->nextblock) {
+ printk(KERN_DEBUG "nextblock: 0x%08x\n", c->nextblock->offset);
+ } else {
+ printk(KERN_DEBUG "nextblock: NULL\n");
+ }
+ if (c->gcblock) {
+ printk(KERN_DEBUG "gcblock: 0x%08x\n", c->gcblock->offset);
+ } else {
+ printk(KERN_DEBUG "gcblock: NULL\n");
+ }
+ if (list_empty(&c->clean_list)) {
+ printk(KERN_DEBUG "clean_list: empty\n");
+ } else {
+ struct list_head *this;
+
+ list_for_each(this, &c->clean_list) {
+ struct jffs2_eraseblock *jeb = list_entry(this, struct jffs2_eraseblock, list);
+ printk(KERN_DEBUG "clean_list: %08x\n", jeb->offset);
+ }
+ }
+ if (list_empty(&c->dirty_list)) {
+ printk(KERN_DEBUG "dirty_list: empty\n");
+ } else {
+ struct list_head *this;
+
+ list_for_each(this, &c->dirty_list) {
+ struct jffs2_eraseblock *jeb = list_entry(this, struct jffs2_eraseblock, list);
+ printk(KERN_DEBUG "dirty_list: %08x\n", jeb->offset);
+ }
+ }
+ if (list_empty(&c->erasing_list)) {
+ printk(KERN_DEBUG "erasing_list: empty\n");
+ } else {
+ struct list_head *this;
+
+ list_for_each(this, &c->erasing_list) {
+ struct jffs2_eraseblock *jeb = list_entry(this, struct jffs2_eraseblock, list);
+ printk(KERN_DEBUG "erasing_list: %08x\n", jeb->offset);
+ }
+ }
+ if (list_empty(&c->erase_pending_list)) {
+ printk(KERN_DEBUG "erase_pending_list: empty\n");
+ } else {
+ struct list_head *this;
+
+ list_for_each(this, &c->erase_pending_list) {
+ struct jffs2_eraseblock *jeb = list_entry(this, struct jffs2_eraseblock, list);
+ printk(KERN_DEBUG "erase_pending_list: %08x\n", jeb->offset);
+ }
+ }
+ if (list_empty(&c->free_list)) {
+ printk(KERN_DEBUG "free_list: empty\n");
+ } else {
+ struct list_head *this;
+
+ list_for_each(this, &c->free_list) {
+ struct jffs2_eraseblock *jeb = list_entry(this, struct jffs2_eraseblock, list);
+ printk(KERN_DEBUG "free_list: %08x\n", jeb->offset);
+ }
+ }
+ if (list_empty(&c->bad_list)) {
+ printk(KERN_DEBUG "bad_list: empty\n");
+ } else {
+ struct list_head *this;
+
+ list_for_each(this, &c->bad_list) {
+ struct jffs2_eraseblock *jeb = list_entry(this, struct jffs2_eraseblock, list);
+ printk(KERN_DEBUG "bad_list: %08x\n", jeb->offset);
+ }
+ }
+ if (list_empty(&c->bad_used_list)) {
+ printk(KERN_DEBUG "bad_used_list: empty\n");
+ } else {
+ struct list_head *this;
+
+ list_for_each(this, &c->bad_used_list) {
+ struct jffs2_eraseblock *jeb = list_entry(this, struct jffs2_eraseblock, list);
+ printk(KERN_DEBUG "bad_used_list: %08x\n", jeb->offset);
+ }
+ }
+#endif /* CONFIG_JFFS2_FS_DEBUG */
+
+ spin_unlock_bh(&c->erase_completion_lock);
+
+
+ return 0;
+}
+
+static struct super_block *jffs2_read_super(struct super_block *sb, void *data, int silent)
+{
+ struct jffs2_sb_info *c;
+ struct inode *root_i;
+ int i;
+
+ D1(printk(KERN_DEBUG "jffs2: read_super for device %s\n", kdevname(sb->s_dev)));
+
+ if (MAJOR(sb->s_dev) != MTD_BLOCK_MAJOR) {
+ if (!silent)
+ printk(KERN_DEBUG "jffs2: attempt to mount non-MTD device %s\n", kdevname(sb->s_dev));
+ return NULL;
+ }
+
+ c = JFFS2_SB_INFO(sb);
+ memset(c, 0, sizeof(*c));
+
+ c->mtd = get_mtd_device(NULL, MINOR(sb->s_dev));
+ if (!c->mtd) {
+ D1(printk(KERN_DEBUG "jffs2: MTD device #%u doesn't appear to exist\n", MINOR(sb->s_dev)));
+ return NULL;
+ }
+ c->sector_size = c->mtd->erasesize;
+ c->free_size = c->flash_size = c->mtd->size;
+ c->nr_blocks = c->mtd->size / c->mtd->erasesize;
+ c->blocks = kmalloc(sizeof(struct jffs2_eraseblock) * c->nr_blocks, GFP_KERNEL);
+ if (!c->blocks)
+ goto out_mtd;
+ for (i=0; i<c->nr_blocks; i++) {
+ INIT_LIST_HEAD(&c->blocks[i].list);
+ c->blocks[i].offset = i * c->sector_size;
+ c->blocks[i].free_size = c->sector_size;
+ c->blocks[i].dirty_size = 0;
+ c->blocks[i].used_size = 0;
+ c->blocks[i].first_node = NULL;
+ c->blocks[i].last_node = NULL;
+ }
+
+ spin_lock_init(&c->nodelist_lock);
+ init_MUTEX(&c->alloc_sem);
+ init_waitqueue_head(&c->erase_wait);
+ spin_lock_init(&c->erase_completion_lock);
+ spin_lock_init(&c->inocache_lock);
+
+ INIT_LIST_HEAD(&c->clean_list);
+ INIT_LIST_HEAD(&c->dirty_list);
+ INIT_LIST_HEAD(&c->erasing_list);
+ INIT_LIST_HEAD(&c->erase_pending_list);
+ INIT_LIST_HEAD(&c->erase_complete_list);
+ INIT_LIST_HEAD(&c->free_list);
+ INIT_LIST_HEAD(&c->bad_list);
+ INIT_LIST_HEAD(&c->bad_used_list);
+ c->highest_ino = 1;
+
+ if (jffs2_build_filesystem(c)) {
+ D1(printk(KERN_DEBUG "build_fs failed\n"));
+ goto out_nodes;
+ }
+ sb->s_op = &jffs2_super_operations;
+
+ D1(printk(KERN_DEBUG "jffs2_read_super(): Getting root inode\n"));
+ root_i = iget(sb, 1);
+ if (is_bad_inode(root_i)) {
+ D1(printk(KERN_WARNING "get root inode failed\n"));
+ goto out_nodes;
+ }
+
+ D1(printk(KERN_DEBUG "jffs2_read_super(): d_alloc_root()\n"));
+ sb->s_root = d_alloc_root(root_i);
+ if (!sb->s_root)
+ goto out_root_i;
+
+#if LINUX_VERSION_CODE >= 0x20403
+ sb->s_maxbytes = 0xFFFFFFFF;
+#endif
+ sb->s_blocksize = PAGE_CACHE_SIZE;
+ sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
+ sb->s_magic = JFFS2_SUPER_MAGIC;
+ if (!(sb->s_flags & MS_RDONLY))
+ jffs2_start_garbage_collect_thread(c);
+ return sb;
+
+ out_root_i:
+ iput(root_i);
+ out_nodes:
+ jffs2_free_ino_caches(c);
+ jffs2_free_raw_node_refs(c);
+ kfree(c->blocks);
+ out_mtd:
+ put_mtd_device(c->mtd);
+ return NULL;
+}
+
+void jffs2_put_super (struct super_block *sb)
+{
+ struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
+
+ D2(printk(KERN_DEBUG "jffs2: jffs2_put_super()\n"));
+
+ if (!(sb->s_flags & MS_RDONLY))
+ jffs2_stop_garbage_collect_thread(c);
+ jffs2_free_ino_caches(c);
+ jffs2_free_raw_node_refs(c);
+ kfree(c->blocks);
+ if (c->mtd->sync)
+ c->mtd->sync(c->mtd);
+ put_mtd_device(c->mtd);
+
+ D1(printk(KERN_DEBUG "jffs2_put_super returning\n"));
+}
+
+int jffs2_remount_fs (struct super_block *sb, int *flags, char *data)
+{
+ struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
+
+ if (c->flags & JFFS2_SB_FLAG_RO && !(sb->s_flags & MS_RDONLY))
+ return -EROFS;
+
+ /* We stop if it was running, then restart if it needs to.
+ This also catches the case where it was stopped and this
+ is just a remount to restart it */
+ if (!(sb->s_flags & MS_RDONLY))
+ jffs2_stop_garbage_collect_thread(c);
+
+ if (!(*flags & MS_RDONLY))
+ jffs2_start_garbage_collect_thread(c);
+
+ sb->s_flags = (sb->s_flags & ~MS_RDONLY)|(*flags & MS_RDONLY);
+
+ return 0;
+}
+
+void jffs2_write_super (struct super_block *sb)
+{
+ struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
+ sb->s_dirt = 0;
+
+ if (sb->s_flags & MS_RDONLY)
+ return;
+
+ jffs2_garbage_collect_trigger(c);
+ jffs2_erase_pending_blocks(c);
+ jffs2_mark_erased_blocks(c);
+}
+
+
+static DECLARE_FSTYPE_DEV(jffs2_fs_type, "jffs2", jffs2_read_super);
+
+static int __init init_jffs2_fs(void)
+{
+ int ret;
+
+ printk(KERN_NOTICE "JFFS2 version 2.1. (C) 2001 Red Hat, Inc., designed by Axis Communications AB.\n");
+
+#ifdef JFFS2_OUT_OF_KERNEL
+ /* sanity checks. Could we do these at compile time? */
+ if (sizeof(struct jffs2_sb_info) > sizeof (((struct super_block *)NULL)->u)) {
+ printk(KERN_ERR "JFFS2 error: struct jffs2_sb_info (%d bytes) doesn't fit in the super_block union (%d bytes)\n",
+ sizeof(struct jffs2_sb_info), sizeof (((struct super_block *)NULL)->u));
+ return -EIO;
+ }
+
+ if (sizeof(struct jffs2_inode_info) > sizeof (((struct inode *)NULL)->u)) {
+ printk(KERN_ERR "JFFS2 error: struct jffs2_inode_info (%d bytes) doesn't fit in the inode union (%d bytes)\n",
+ sizeof(struct jffs2_inode_info), sizeof (((struct inode *)NULL)->u));
+ return -EIO;
+ }
+#endif
+
+ ret = jffs2_create_slab_caches();
+ if (ret) {
+ printk(KERN_ERR "JFFS2 error: Failed to initialise slab caches\n");
+ return ret;
+ }
+ ret = register_filesystem(&jffs2_fs_type);
+ if (ret) {
+ printk(KERN_ERR "JFFS2 error: Failed to register filesystem\n");
+ jffs2_destroy_slab_caches();
+ }
+ return ret;
+}
+
+static void __exit exit_jffs2_fs(void)
+{
+ jffs2_destroy_slab_caches();
+ unregister_filesystem(&jffs2_fs_type);
+}
+
+module_init(init_jffs2_fs);
+module_exit(exit_jffs2_fs);
+
+MODULE_DESCRIPTION("The Journalling Flash File System, v2");
+MODULE_AUTHOR("Red Hat, Inc.");
+MODULE_LICENSE("GPL"); // Actually dual-licensed, but it doesn't matter for
+ // the sake of this tag. It's Free Software.
+/*
+ * YAFFS: Yet another FFS. A NAND-flash specific file system.
+ *
+ * Copyright (C) 2002 Aleph One Ltd.
+ * for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
--- /dev/null
+/*
+ * YAFFS: Yet another FFS. A NAND-flash specific file system.
+ * yaffsdev.c
+ *
+ * Copyright (C) 2002 Aleph One Ltd.
+ * for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include "yaffsinterface.h"
+#include "yaffs_nandemul.h"
+#include "yaffs_guts.h"
+#include <stdlib.h>
+
+#include <stdio.h>
+#include <string.h>
+
+
+
+
+
+yaffs_Device device;
+
+
+
+
+
+
+
+char *testStr = "this is a test string";
+
+char *testStr2 = "abcdefghijklmnopqrstuvwxyz1234567890";
+
+void TestTimexxx(yaffs_Device *dev)
+{
+ yaffs_Object *f;
+ int x;
+
+
+ printf("Start\n");
+
+
+ f = yaffs_FindObjectByName(yaffs_Root(dev),"Name1");
+ if(f)
+ {
+ printf("Found\n");
+ }
+ else
+ {
+ f = yaffs_MknodFile(yaffs_Root(dev),"Name1",0,0,0);
+ printf("Created\n");
+ }
+
+
+ x = yaffs_RenameObject(yaffs_Root(dev),"Name1",NULL,"Rename");
+
+}
+
+
+void TestTimeasasas(yaffs_Device *dev)
+{
+ yaffs_Object *f;
+ int x;
+ int i;
+ int b;
+ char data[200];
+ int written;
+
+
+ printf("Start\n");
+
+
+ f = yaffs_FindObjectByName(yaffs_Root(dev),"Name1");
+ if(f)
+ {
+ printf("Found\n");
+ }
+ else
+ {
+ f = yaffs_MknodFile(yaffs_Root(dev),"Name1",0,0,0);
+ printf("Created\n");
+ }
+
+
+ x = yaffs_RenameObject(yaffs_Root(dev),"Name1",NULL,"Rename");
+
+
+
+ for(i = 0; i < 10000; i+=20)
+ {
+
+ b++;
+ if(b & 1)
+ written = yaffs_WriteDataToFile(f,testStr,i,strlen(testStr));
+ else
+ written = yaffs_WriteDataToFile(f,testStr2,i,strlen(testStr2));
+ }
+
+
+ yaffs_ApplyToDirectoryChildren(yaffs_Root(dev),yaffs_DumpObject);
+
+ printf("Flush\n");
+
+ yaffs_FlushFile(f);
+
+ yaffs_ApplyToDirectoryChildren(yaffs_Root(dev),yaffs_DumpObject);
+
+ yaffs_ReadDataFromFile(f,data,1000,50);
+ data[50] = 0;
+
+ printf("Read data is \"%s\"\n",data);
+
+ yaffs_DumpObject(f);
+
+ printf("Resize\n");
+ yaffs_ResizeFile(f,2000);
+
+ yaffs_DumpObject(f);
+
+ yaffs_FlushFile(f);
+
+
+
+
+}
+
+void TestTime(yaffs_Device *dev)
+{
+ yaffs_Object *f;
+ yaffs_Object *sl;
+ yaffs_Object *lnf;
+
+ yaffs_Object *hl1;
+ yaffs_Object *hl2;
+ yaffs_Object *hl3;
+ yaffs_Object *d, *df;
+
+ int x;
+ int i;
+ int b;
+ char data[200];
+
+ char * alias;
+ int written;
+
+
+ printf("Start\n");
+
+
+ f = yaffs_FindObjectByName(yaffs_Root(dev),"Name1");
+ if(f)
+ {
+ printf("Found\n");
+ }
+ else
+ {
+ f = yaffs_MknodFile(yaffs_Root(dev),"Name1",0,0,0);
+ printf("Created\n");
+ }
+
+
+ x = yaffs_RenameObject(yaffs_Root(dev),"Name1",NULL,"Rename");
+
+ for(i = 0; i < 100000; i+=20)
+ {
+
+ b++;
+ if(b & 1)
+ written = yaffs_WriteDataToFile(f,testStr,i,strlen(testStr));
+ else
+ written = yaffs_WriteDataToFile(f,testStr2,i,strlen(testStr2));
+ }
+
+ yaffs_ApplyToDirectoryChildren(yaffs_Root(dev),yaffs_DumpObject);
+
+ printf("Flush\n");
+
+ yaffs_FlushFile(f);
+
+ printf("File length is %d\n",yaffs_GetObjectFileLength(f));
+
+ sl = yaffs_MknodSymLink(yaffs_Root(dev),"sym-link",0,0,0,"/tmp/alias");
+
+
+ yaffs_ApplyToDirectoryChildren(yaffs_Root(dev),yaffs_DumpObject);
+
+ printf("\n\nsymlink alias is \"%s\"\n",alias = yaffs_GetSymlinkAlias(sl));
+
+ free(alias);
+
+ printf("Unlink symlink %d\n",yaffs_Unlink(yaffs_Root(dev),"sym-link"));
+
+
+ yaffs_ReadDataFromFile(f,data,1000,50);
+ data[50] = 0;
+
+ printf("Read data is \"%s\"\n",data);
+
+ yaffs_DumpObject(f);
+
+ printf("Resize\n");
+ yaffs_ResizeFile(f,2000);
+
+ yaffs_DumpObject(f);
+
+ lnf = yaffs_FindObjectByName(yaffs_Root(dev),YAFFS_LOSTNFOUND_NAME);
+
+
+
+ yaffs_FlushFile(f);
+
+
+ printf("Unlink file: %d\n",yaffs_Unlink(yaffs_Root(dev),"Rename"));
+
+ yaffs_ApplyToDirectoryChildren(yaffs_Root(dev),yaffs_DumpObject);
+
+ // Create a directory and play with it
+
+
+ printf("Create directory and play with it\n");
+
+ d = yaffs_MknodDirectory(yaffs_Root(dev),"direct",0,0,0);
+ yaffs_ApplyToDirectoryChildren(yaffs_Root(dev),yaffs_DumpObject);
+ yaffs_ApplyToDirectoryChildren(d,yaffs_DumpObject);
+
+ printf("Make file in directory\n");
+
+ df = yaffs_MknodFile(d,"file-in-directory",0,0,0);
+ yaffs_ApplyToDirectoryChildren(d,yaffs_DumpObject);
+
+
+ // Do some stuff with hardlinks
+ //
+ // NB Deleting hardlinked objects can mess up pointers to hardlinks.
+ // The mechanism is as follows:
+ // * If you unlink a file,softlink or directory that has one or more hardlinks,
+ // then the object is renamed to one of the hardlinks and that hardlink is unlinked.
+ // This means that a pointer to a hardlink so deleted will point to an invalid address.
+ // Thus, make sure that pointers to hardlinks are immediately dereferenced.
+
+
+ printf("Hard link tests\n");
+
+ f = yaffs_MknodFile(yaffs_Root(dev),"Name1",0,0,0);
+ hl1 = yaffs_Link(yaffs_Root(dev),"HardLink 1",f);
+ hl2 = yaffs_Link(yaffs_Root(dev),"HardLink 2",f);
+ hl3 = yaffs_Link(yaffs_Root(dev),"HardLink 3",hl2);
+
+ printf("\n\nHard links created\n");
+ yaffs_ApplyToDirectoryChildren(yaffs_Root(dev),yaffs_DumpObject);
+
+ yaffs_Unlink(yaffs_Root(dev),"HardLink 1");
+ printf("\n\nHard link deleted\n");
+ yaffs_ApplyToDirectoryChildren(yaffs_Root(dev),yaffs_DumpObject);
+
+ yaffs_Unlink(yaffs_Root(dev),"Name1");
+ printf("\n\nHard linked file deleted\n");
+ yaffs_ApplyToDirectoryChildren(yaffs_Root(dev),yaffs_DumpObject);
+
+ yaffs_Unlink(yaffs_Root(dev),"HardLink 2");
+ printf("\n\nHard link 2 deleted\n");
+ yaffs_ApplyToDirectoryChildren(yaffs_Root(dev),yaffs_DumpObject);
+
+ yaffs_Unlink(yaffs_Root(dev),"HardLink 3");
+
+ printf("\n\nHard link 3 deleted\n");
+ yaffs_ApplyToDirectoryChildren(yaffs_Root(dev),yaffs_DumpObject);
+
+ // NB We don't allow unlinking or rename of the root or lost+found
+ // We allow setting attributes, but these must not be written to
+ // NAND since they are not real objects.
+
+ printf("Attempt to rename lost+found - should have failed\n");
+ x = yaffs_RenameObject(yaffs_Root(dev),YAFFS_LOSTNFOUND_NAME,NULL,"Renamed");
+ yaffs_ApplyToDirectoryChildren(yaffs_Root(dev),yaffs_DumpObject);
+
+}
+
+int main(int argc,char *argv[])
+{
+ device.nBlocks = (2 * 1024 * 1024) / (YAFFS_CHUNKS_PER_BLOCK * YAFFS_BYTES_PER_CHUNK);
+ device.startBlock = 1; // Don't use block 0
+ device.endBlock = device.nBlocks - 1;
+
+ device.writeChunkToNAND = nandemul_WriteChunkToNAND;
+ device.readChunkFromNAND = nandemul_ReadChunkFromNAND;
+ device.eraseBlockInNAND = nandemul_EraseBlockInNAND;
+ device.initialiseNAND = nandemul_InitialiseNAND;
+
+ yaffs_GutsInitialise(&device);
+
+ // yaffs_GutsTest();
+
+ TestTime(&device);
+
+ exit(0);
+}
--- /dev/null
+/*
+ * YAFFS: Yet another FFS. A NAND-flash specific file system.
+ * yaffsinterface.h: Interface to the guts of yaffs.
+ *
+ * Copyright (C) 2002 Aleph One Ltd.
+ * for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#ifndef __YAFFSINTERFACE_H__
+#define __YAFFSINTERFACE_H__
+
+
+int yaffs_Initialise(unsigned nBlocks);
+
+#endif
+
--- /dev/null
+/*
+ * YAFFS: Yet another FFS. A NAND-flash specific file system.
+ * yportenv.h: Portable services used by yaffs. This is done to allow
+ * simple migration from kernel space into app space for testing.
+ *
+ * Copyright (C) 2002 Aleph One Ltd.
+ * for Toby Churchill Ltd and Brightstar Engineering
+ *
+ * Created by Charles Manning <charles@aleph1.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#ifndef __PORTENV_H__
+#define __PORTENV_H__
+
+#ifndef __KERNEL__
+
+#include "stdlib.h"
+#include "stdio.h"
+#include "string.h"
+
+#define YPRINTF(x) printf x
+#define YMALLOC(x) malloc(x)
+#define YFREE(x) free(x)
+
+
+#define YINFO(s) YPRINTF(( __FILE__ " %d %s\n",__LINE__,s))
+#define YALERT(s) YINFO(s)
+
+#else
+
+#include "linux/kernel.h"
+#include "linux/mm.h"
+#include "linux/string.h"
+#include "linux/slab.h"
+
+#define YPRINTF(x) printk x
+#define YMALLOC(x) kmalloc(x,GFP_KERNEL)
+#define YFREE(x) kfree(x)
+
+#endif
+
+
+
+#define YINFO(s) YPRINTF((KERN_DEBUG __FILE__ " %d %s\n",__LINE__,s))
+#define YALERT(s) YINFO(s)
+
+#endif
+
+
+
+