Change Linux glue code to work with 2.6.28
authorcharles <charles>
Thu, 22 Jan 2009 00:45:54 +0000 (00:45 +0000)
committercharles <charles>
Thu, 22 Jan 2009 00:45:54 +0000 (00:45 +0000)
yaffs_fs.c

index b57b657..9c11b5d 100644 (file)
@@ -32,7 +32,7 @@
  */
 
 const char *yaffs_fs_c_version =
-    "$Id: yaffs_fs.c,v 1.70 2009-01-18 21:50:37 charles Exp $";
+    "$Id: yaffs_fs.c,v 1.71 2009-01-22 00:45:54 charles Exp $";
 extern const char *yaffs_guts_c_version;
 
 #include <linux/version.h>
@@ -91,6 +91,13 @@ extern const char *yaffs_guts_c_version;
 #define WRITE_SIZE(mtd) (mtd)->oobblock
 #endif
 
+#if(LINUX_VERSION_CODE > KERNEL_VERSION(2,6,27))
+#define YAFFS_USE_WRITE_BEGIN_END 1
+#else
+#define YAFFS_USE_WRITE_BEGIN_END 0
+#endif
+
+
 #include <asm/uaccess.h>
 
 #include "yportenv.h"
@@ -150,6 +157,8 @@ static void yaffs_put_super(struct super_block *sb);
 
 static ssize_t yaffs_file_write(struct file *f, const char *buf, size_t n,
                                loff_t * pos);
+static ssize_t yaffs_hold_space(struct file *f);
+static void yaffs_release_space(struct file *f);
 
 #if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,17))
 static int yaffs_file_flush(struct file *file, fl_owner_t id);
@@ -218,10 +227,22 @@ static int yaffs_writepage(struct page *page, struct writeback_control *wbc);
 #else
 static int yaffs_writepage(struct page *page);
 #endif
+
+
+#if (YAFFS_USE_WRITE_BEGIN_END != 0)
+static int yaffs_write_begin(struct file *filp, struct address_space *mapping,
+                             loff_t pos, unsigned len, unsigned flags,
+                          struct page **pagep, void **fsdata);
+static int yaffs_write_end(struct file *filp, struct address_space *mapping,
+                          loff_t pos, unsigned len, unsigned copied,
+                          struct page *pg, void *fsdadata);
+#else
 static int yaffs_prepare_write(struct file *f, struct page *pg,
                               unsigned offset, unsigned to);
 static int yaffs_commit_write(struct file *f, struct page *pg, unsigned offset,
                              unsigned to);
+                                                                                                
+#endif
 
 static int yaffs_readlink(struct dentry *dentry, char __user * buffer,
                          int buflen);
@@ -234,8 +255,13 @@ static int yaffs_follow_link(struct dentry *dentry, struct nameidata *nd);
 static struct address_space_operations yaffs_file_address_operations = {
        .readpage = yaffs_readpage,
        .writepage = yaffs_writepage,
+#if (YAFFS_USE_WRITE_BEGIN_END > 0)
+       .write_begin = yaffs_write_begin,
+       .write_end = yaffs_write_end,
+#else
        .prepare_write = yaffs_prepare_write,
        .commit_write = yaffs_commit_write,
+#endif
 };
 
 #if (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,22))
@@ -249,6 +275,7 @@ static struct file_operations yaffs_file_operations = {
        .fsync = yaffs_sync_object,
        .splice_read = generic_file_splice_read,
        .splice_write = generic_file_splice_write,
+       .llseek = generic_file_llseek,
 };
 
 #elif (LINUX_VERSION_CODE > KERNEL_VERSION(2,6,18))
@@ -701,6 +728,64 @@ static int yaffs_writepage(struct page *page)
        return (nWritten == nBytes) ? 0 : -ENOSPC;
 }
 
+
+#if (YAFFS_USE_WRITE_BEGIN_END > 0)
+static int yaffs_write_begin(struct file *filp, struct address_space *mapping,
+                             loff_t pos, unsigned len, unsigned flags,
+                          struct page **pagep, void **fsdata)
+
+{
+       struct page *pg = NULL;
+        pgoff_t index = pos >> PAGE_CACHE_SHIFT;
+        uint32_t offset = pos & (PAGE_CACHE_SIZE - 1);
+        uint32_t to = offset + len;
+        
+        int ret = 0;
+        int space_held = 0;
+        
+       T(YAFFS_TRACE_OS, (KERN_DEBUG "start yaffs_write_begin\n"));
+       /* Get a page */
+       pg = __grab_cache_page(mapping,index);
+       *pagep = pg;    
+       if(!pg){
+               ret =  -ENOMEM;
+               goto out;
+       }
+       /* Get fs space */
+       space_held = yaffs_hold_space(filp);
+       
+       if(!space_held){
+               ret = -ENOSPC;
+               goto out;
+       }
+               
+       /* Update page if required */
+       
+       if (!Page_Uptodate(pg) && (offset || to < PAGE_CACHE_SIZE))
+               ret = yaffs_readpage_nolock(filp, pg);
+       
+       if(ret)
+               goto out;
+
+       /* Happy path return */
+       T(YAFFS_TRACE_OS, (KERN_DEBUG "end yaffs_write_begin - ok\n"));
+               
+       return 0;
+               
+out:
+       T(YAFFS_TRACE_OS, (KERN_DEBUG "end yaffs_write_begin fail returning %d\n",ret));
+       if(space_held){
+               yaffs_release_space(filp);
+       }
+       if(pg) {
+               unlock_page(pg);
+               page_cache_release(pg);
+       }
+       return ret;
+}
+
+#else
+
 static int yaffs_prepare_write(struct file *f, struct page *pg,
                               unsigned offset, unsigned to)
 {
@@ -708,10 +793,51 @@ static int yaffs_prepare_write(struct file *f, struct page *pg,
        T(YAFFS_TRACE_OS, (KERN_DEBUG "yaffs_prepair_write\n"));
        if (!Page_Uptodate(pg) && (offset || to < PAGE_CACHE_SIZE))
                return yaffs_readpage_nolock(f, pg);
-
        return 0;
 
 }
+#endif
+
+#if (YAFFS_USE_WRITE_BEGIN_END > 0)
+static int yaffs_write_end(struct file *filp, struct address_space *mapping,
+                          loff_t pos, unsigned len, unsigned copied,
+                          struct page *pg, void *fsdadata)
+{
+       int ret = 0;
+       void *addr, *kva;
+        pgoff_t index = pos >> PAGE_CACHE_SHIFT;
+        uint32_t offset_into_page = pos & (PAGE_CACHE_SIZE -1); 
+
+
+       
+       kva=kmap(pg);
+       addr = kva + offset_into_page;
+
+       T(YAFFS_TRACE_OS,
+         (KERN_DEBUG "yaffs_write_end addr %x pos %x nBytes %d\n", (unsigned) addr,
+          (int)pos, copied));
+
+       ret = yaffs_file_write(filp, addr, copied, &pos);
+
+       if (ret != copied) {
+               T(YAFFS_TRACE_OS,
+                 (KERN_DEBUG
+                  "yaffs_write_end not same size ret %d  copied %d\n",
+                  ret, copied ));
+               SetPageError(pg);
+               ClearPageUptodate(pg);
+       } else {
+               SetPageUptodate(pg);
+       }
+
+       kunmap(pg);
+
+       yaffs_release_space(filp);
+       unlock_page(pg);
+       page_cache_release(pg);
+       return ret;
+}
+#else
 
 static int yaffs_commit_write(struct file *f, struct page *pg, unsigned offset,
                              unsigned to)
@@ -724,11 +850,13 @@ static int yaffs_commit_write(struct file *f, struct page *pg, unsigned offset,
        int nWritten;
 
        unsigned spos = pos;
-       unsigned saddr = (unsigned)addr;
+       unsigned saddr;
        
        kva=kmap(pg);
        addr = kva + offset;
 
+       saddr = (unsigned) addr;
+
        T(YAFFS_TRACE_OS,
          (KERN_DEBUG "yaffs_commit_write addr %x pos %x nBytes %d\n", saddr,
           spos, nBytes));
@@ -755,6 +883,8 @@ static int yaffs_commit_write(struct file *f, struct page *pg, unsigned offset,
        return nWritten == nBytes ? 0 : nWritten;
 
 }
+#endif
+
 
 static void yaffs_FillInodeFromObject(struct inode *inode, yaffs_Object * obj)
 {
@@ -954,6 +1084,48 @@ static ssize_t yaffs_file_write(struct file *f, const char *buf, size_t n,
        return nWritten == 0 ? -ENOSPC : nWritten;
 }
 
+/* Space holding and freeing is done to ensure we have space available for write_begin/end */
+/* For now we just assume few parallel writes and check against a small number. */
+/* Todo: need to do this with a counter to handle parallel reads better */
+
+static ssize_t yaffs_hold_space(struct file *f)
+{
+       yaffs_Object *obj;
+       yaffs_Device *dev;
+       
+       int nFreeChunks;
+
+       
+       obj = yaffs_DentryToObject(f->f_dentry);
+
+       dev = obj->myDev;
+
+       yaffs_GrossLock(dev);
+
+       nFreeChunks = yaffs_GetNumberOfFreeChunks(dev);
+       
+       yaffs_GrossUnlock(dev);
+
+       return (nFreeChunks > 20) ? 1 : 0;
+}
+
+static void yaffs_release_space(struct file *f)
+{
+       yaffs_Object *obj;
+       yaffs_Device *dev;
+       
+       
+       obj = yaffs_DentryToObject(f->f_dentry);
+
+       dev = obj->myDev;
+
+       yaffs_GrossLock(dev);
+
+       
+       yaffs_GrossUnlock(dev);
+
+}
+
 static int yaffs_readdir(struct file *f, void *dirent, filldir_t filldir)
 {
        yaffs_Object *obj;