yaffs_fs.c

   1 /*
   2  * YAFFS: Yet another FFS. A NAND-flash specific file system.
   3  * yaffs_fs.c
   4  *
   5  * Copyright (C) 2002 Aleph One Ltd.
   6  *   for Toby Churchill Ltd and Brightstar Engineering
   7  *
   8  * Created by Charles Manning <charles@aleph1.co.uk>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  *
  14  * This is the file system front-end to YAFFS that hooks it up to
  15  * the VFS.
  16  *
  17  * Special notes:
  18  * >> sb->u.generic_sbp points to the yaffs_Device associated with this superblock
  19  * >> inode->u.generic_ip points to the associated yaffs_Object.
  20  */
  21
  22
  23 #include <linux/config.h>
  24 #include <linux/kernel.h>
  25 #include <linux/module.h>
  26 #include <linux/version.h>
  27 #include <linux/slab.h>
  28 #include <linux/init.h>
  29 #include <linux/list.h>
  30 #include <linux/fs.h>
  31 #include <linux/proc_fs.h>
  32 #include <linux/pagemap.h>
  33 #include <linux/mtd/mtd.h>
  34 #include <linux/interrupt.h>
  35 #include <linux/string.h>
  36 #include <linux/locks.h>
  37
  38 #include <asm/uaccess.h>
  39
  40 #include "yaffs_guts.h"
  41
  42 #ifdef YAFFS_RAM_ENABLED
  43 #include "yaffs_nandemul.h"
  44 // 2 MB of RAM for emulation
  45 #define YAFFS_RAM_EMULATION_SIZE  0x200000
  46 #endif //YAFFS_RAM_ENABLED
  47
  48 #ifdef YAFFS_MTD_ENABLED
  49 #include <linux/mtd/mtd.h>
  50 #include "yaffs_mtdif.h"
  51 #endif //YAFFS_MTD_ENABLED
  52
  53 #define T(x) printk x
  54
  55
  56
  57 #define yaffs_InodeToObject(iptr) ((yaffs_Object *)((iptr)->u.generic_ip))
  58 #define yaffs_DentryToObject(dptr) yaffs_InodeToObject((dptr)->d_inode)
  59 #define yaffs_SuperToDevice(sb) ((yaffs_Device *)sb->u.generic_sbp)
  60
  61
  62
  63 static void yaffs_put_super(struct super_block *sb);
  64
  65 static ssize_t yaffs_file_read(struct file *f, char *buf, size_t n, loff_t *pos);
  66 static ssize_t yaffs_file_write(struct file *f, const char *buf, size_t n, loff_t *pos);
  67
  68 static int yaffs_sync_object(struct file * file, struct dentry *dentry, int datasync);
  69
  70 static int yaffs_readdir(struct file *f, void *dirent, filldir_t filldir);
  71
  72 static int yaffs_create(struct inode *dir, struct dentry *dentry, int mode);
  73 static struct dentry * yaffs_lookup(struct inode *dir, struct dentry *dentry);
  74 static int yaffs_link(struct dentry *old_dentry, struct inode * dir, struct dentry * dentry);
  75 static int yaffs_unlink(struct inode * dir, struct dentry *dentry);
  76 static int yaffs_symlink(struct inode * dir, struct dentry *dentry, const char * symname);
  77 static int yaffs_mkdir(struct inode * dir, struct dentry * dentry, int mode);
  78 static int yaffs_mknod(struct inode *dir, struct dentry *dentry, int mode, int dev);
  79 static int yaffs_rename(struct inode * old_dir, struct dentry *old_dentry, struct inode * new_dir,struct dentry *new_dentry);
  80 static int yaffs_setattr(struct dentry *dentry, struct iattr *attr);
  81
  82 static int yaffs_statfs(struct super_block *sb, struct statfs *buf);
  83 static void yaffs_read_inode (struct inode *inode);
  84 static struct super_block *yaffs_read_super(struct super_block * sb, void * data, int silent);
  85 static void yaffs_put_inode (struct inode *inode);
  86
  87 //static int yaffs_readpage(struct file*,struct page *
  88
  89 static struct address_space_operations yaffs_address_ops = {
  90 //      readpage:               yaffs_readpage,
  91 //      prepare_write:  yaffs_prepare_write,
  92 //      commit_write:   yaffs_commit_write
  93 };
  94
  95
  96 static struct file_operations yaffs_file_operations = {
  97         read:           yaffs_file_read,
  98         write:          yaffs_file_write,
  99 //      mmap:           generic_file_mmap,
 100         fsync:          yaffs_sync_object,
 101 };
 102
 103
 104 static struct inode_operations yaffs_file_inode_operations = {
 105         setattr:        yaffs_setattr,
 106 };
 107
 108
 109
 110 static struct file_operations yaffs_dir_operations = {
 111         read:           generic_read_dir,
 112         readdir:        yaffs_readdir,
 113         fsync:          yaffs_sync_object,
 114 };
 115
 116 static struct inode_operations yaffs_dir_inode_operations = {
 117         create:         yaffs_create,
 118         lookup:         yaffs_lookup,
 119         link:           yaffs_link,
 120         unlink:         yaffs_unlink,
 121         symlink:        yaffs_symlink,
 122         mkdir:          yaffs_mkdir,
 123         rmdir:          yaffs_unlink,
 124         mknod:          yaffs_mknod,
 125         rename:         yaffs_rename,
 126         setattr:        yaffs_setattr,
 127 };
 128
 129 static struct super_operations yaffs_super_ops = {
 130         statfs:                 yaffs_statfs,
 131         read_inode:             yaffs_read_inode,
 132         put_inode:              yaffs_put_inode,
 133         put_super:              yaffs_put_super,
 134 //      read_inode:
 135 //      remount_fs:
 136 //      clear_inode:
 137 };
 138
 139
 140 struct inode *yaffs_get_inode(struct super_block *sb, int mode, int dev,yaffs_Object *obj);
 141
 142 /*
 143  * Lookup is used to find objects in the fs
 144  */
 145 static struct dentry * yaffs_lookup(struct inode *dir, struct dentry *dentry)
 146 {
 147         yaffs_Object *obj;
 148         struct inode *inode;
 149
 150
 151         T((KERN_DEBUG"yaffs_lookup for %d:%s\n",yaffs_InodeToObject(dir)->objectId,dentry->d_name.name));
 152
 153         obj = yaffs_FindObjectByName(yaffs_InodeToObject(dir),dentry->d_name.name);
 154
 155         if(obj)
 156         {
 157                 T((KERN_DEBUG"yaffs_lookup found %d\n",obj->objectId));
 158
 159                 inode = yaffs_get_inode(dir->i_sb, obj->st_mode,0,obj);
 160
 161                 if(inode)
 162                 {
 163                         T((KERN_DEBUG"yaffs_loookup looks good\n"));
 164                         dget(dentry); // try to solve directory bug
 165                         d_add(dentry,inode);
 166                         return dentry;
 167                 }
 168
 169         }
 170         else
 171         {
 172                 T((KERN_DEBUG"yaffs_lookup not found\n"));
 173
 174         }
 175         return NULL;
 176
 177 }
 178
 179 // For now put inode is just for debugging
 180 static void yaffs_put_inode(struct inode *inode)
 181 {
 182         T(("yaffs_put_inode: ino %d, count %d\n",(int)inode->i_ino, atomic_read(&inode->i_count)));
 183
 184         yaffs_FlushFile(yaffs_InodeToObject(inode));
 185
 186 }
 187
 188 #ifdef YAFFS_ADDRESS_OPS
 189 static int yaffs_readpage(struct file *file, struct page * page)
 190 {
 191         T((KERN_DEBUG"yaffs_readpage\n"));
 192
 193         // TODO
 194         return 0;
 195 }
 196
 197 static int yaffs_prepare_write(struct file *file, struct page *page, unsigned offset, unsigned to)
 198 {
 199         T((KERN_DEBUG"yaffs_prepare_write\n"));
 200
 201         //TODO
 202         return 0;
 203 }
 204
 205 static int yaffs_commit_write(struct file *file, struct page *page, unsigned offset, unsigned to)
 206 {
 207
 208         struct inode *inode = page->mapping->host;
 209         loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
 210
 211         T((KERN_DEBUG"yaffs_commit_write\n"));
 212
 213         return 0;
 214 }
 215
 216 #endif //YAFFS_ADDRESS_OPS
 217
 218
 219 static void yaffs_FillInodeFromObject(struct inode *inode, yaffs_Object *obj)
 220 {
 221         if (inode && obj)
 222         {
 223                 inode->i_ino = obj->objectId;
 224                 inode->i_mode = obj->st_mode;
 225                 inode->i_uid = obj->st_uid;
 226                 inode->i_gid = obj->st_gid;
 227                 inode->i_blksize = YAFFS_BYTES_PER_CHUNK;
 228                 inode->i_blocks = 0;
 229                 inode->i_rdev = NODEV;
 230                 inode->i_mapping->a_ops = &yaffs_address_ops;
 231                 inode->i_atime = obj->st_atime;
 232                 inode->i_mtime = obj->st_mtime;
 233                 inode->i_ctime = obj->st_ctime;
 234                 inode->i_size = yaffs_GetObjectFileLength(obj);
 235                 inode->i_nlink = yaffs_GetObjectLinkCount(obj);
 236
 237                 T((KERN_DEBUG"yaffs_FillInode mode %x uid %d gid %d size %d count %d\n",
 238                                 inode->i_mode, inode->i_uid, inode->i_gid, (int)inode->i_size, atomic_read(&inode->i_count)));
 239
 240                 switch (obj->st_mode & S_IFMT)
 241                 {
 242                         default:
 243                         //      init_special_inode(inode, mode, dev);
 244                                 break;
 245                         case S_IFREG:   // file
 246                                 inode->i_op = &yaffs_file_inode_operations;
 247                                 inode->i_fop = &yaffs_file_operations;
 248                                 break;
 249                         case S_IFDIR:   // directory
 250                                 inode->i_op = &yaffs_dir_inode_operations;
 251                                 inode->i_fop = &yaffs_dir_operations;
 252                                 break;
 253                         case S_IFLNK:   // symlink
 254                                 inode->i_op = &page_symlink_inode_operations;
 255                                 break;
 256                 }
 257
 258
 259                 inode->u.generic_ip = obj;
 260
 261         }
 262         else
 263         {
 264                 T((KERN_DEBUG"yaffs_FileInode invalid parameters\n"));
 265         }
 266
 267 }
 268
 269 struct inode *yaffs_get_inode(struct super_block *sb, int mode, int dev,yaffs_Object *obj)
 270 {
 271         struct inode * inode;
 272
 273         T((KERN_DEBUG"yaffs_get_inode for object %d\n",obj->objectId));
 274
 275         inode = iget(sb,obj->objectId);
 276
 277         // No need to call this since iget calls it via the read_inode callback
 278         // yaffs_FillInodeFromObject(inode,obj);
 279
 280         return inode;
 281 }
 282
 283 static ssize_t yaffs_file_read(struct file *f, char *buf, size_t n, loff_t *pos)
 284 {
 285         yaffs_Object *obj;
 286         int nRead,ipos;
 287         struct inode *inode;
 288
 289         T((KERN_DEBUG"yaffs_file_read\n"));
 290
 291         obj  = yaffs_DentryToObject(f->f_dentry);
 292         inode = f->f_dentry->d_inode;
 293
 294         if (*pos < inode->i_size)
 295         {
 296                         if (*pos + n > inode->i_size)
 297                         {
 298                                 n = inode->i_size - *pos;
 299                         }
 300         }
 301         else
 302         {
 303                 n = 0;
 304         }
 305
 306         nRead = yaffs_ReadDataFromFile(obj,buf,*pos,n);
 307         if(nRead > 0)
 308         {
 309                 f->f_pos += nRead;
 310         }
 311         ipos = *pos;
 312         T((KERN_DEBUG"yaffs_file_read read %d bytes, %d read at %d\n",n,nRead,ipos));
 313         return nRead;
 314
 315 }
 316
 317 static ssize_t yaffs_file_write(struct file *f, const char *buf, size_t n, loff_t *pos)
 318 {
 319         yaffs_Object *obj;
 320         int nWritten,ipos;
 321         struct inode *inode;
 322
 323         obj  = yaffs_DentryToObject(f->f_dentry);
 324         inode = f->f_dentry->d_inode;
 325         nWritten = yaffs_WriteDataToFile(obj,buf,*pos,n);
 326         ipos = *pos;
 327         T((KERN_DEBUG"yaffs_file_write writing %d bytes, %d written at %d\n",n,nWritten,ipos));
 328         if(nWritten > 0)
 329         {
 330                 *pos += nWritten;
 331                 ipos = *pos;
 332                 if(*pos > inode->i_size)
 333                 {
 334                         inode->i_size = *pos;
 335                         T((KERN_DEBUG"yaffs_file_write size updated to %d\n",ipos));
 336                 }
 337
 338         }
 339         return nWritten;
 340 }
 341
 342
 343 static int yaffs_readdir(struct file *f, void *dirent, filldir_t filldir)
 344 {
 345         yaffs_Object *obj;
 346         struct inode *inode = f->f_dentry->d_inode;
 347         unsigned long offset, curoffs;
 348         struct list_head *i;
 349         yaffs_Object *l;
 350
 351         char name[YAFFS_MAX_NAME_LENGTH +1];
 352
 353         obj =  yaffs_DentryToObject(f->f_dentry);
 354
 355         offset = f->f_pos;
 356
 357         T(("yaffs_readdir: starting at %d\n",(int)offset));
 358
 359         if(offset == 0)
 360         {
 361         T((KERN_DEBUG"yaffs_readdir: entry . ino %d \n",(int)inode->i_ino));
 362                 if(filldir(dirent,".",1,offset,inode->i_ino,DT_DIR) < 0)
 363                 {
 364                         goto out;
 365                 }
 366                 offset++;
 367                 f->f_pos++;
 368         }
 369         if(offset == 1)
 370         {
 371                 T((KERN_DEBUG"yaffs_readdir: entry .. ino %d \n",(int)f->f_dentry->d_parent->d_inode->i_ino));
 372                 if(filldir(dirent,"..",2,offset,f->f_dentry->d_parent->d_inode->i_ino,DT_DIR) < 0)
 373                 {
 374                         goto out;
 375                 }
 376                 offset++;
 377                 f->f_pos++;
 378         }
 379
 380         curoffs = 1;
 381
 382         //down(&obj->sem);
 383
 384
 385         list_for_each(i,&obj->variant.directoryVariant.children)
 386         {
 387                 curoffs++;
 388                 if(curoffs >= offset)
 389                 {
 390                         l = list_entry(i, yaffs_Object,siblings);
 391
 392                         yaffs_GetObjectName(l,name,YAFFS_MAX_NAME_LENGTH+1);
 393                         T((KERN_DEBUG"yaffs_readdir: %s inode %d\n",name,yaffs_GetObjectInode(l)));
 394
 395                         if(filldir(dirent,
 396                                            name,
 397                                            strlen(name),
 398                                            offset,
 399                                            yaffs_GetObjectInode(l),
 400                                            yaffs_GetObjectType(l))
 401                                            < 0)
 402                         {
 403                                 goto up_and_out;
 404                         }
 405
 406                         offset++;
 407                         f->f_pos++;
 408                 }
 409         }
 410
 411   up_and_out:
 412
 413         //up(&obj->sem);
 414
 415   out:
 416         return 0;
 417 }
 418
 419
 420 /*
 421  * File creation. Allocate an inode, and we're done..
 422  */
 423 static int yaffs_mknod(struct inode *dir, struct dentry *dentry, int mode, int dev)
 424 {
 425         struct inode *inode;
 426
 427         yaffs_Object *obj = NULL;
 428         yaffs_Object *parent = yaffs_InodeToObject(dir);
 429
 430         int error = -ENOSPC;
 431
 432         if(parent)
 433         {
 434                 T((KERN_DEBUG"yaffs_mknod: parent object %d type %d\n",
 435                                          parent->objectId,parent->variantType));
 436         }
 437         else
 438         {
 439                 T((KERN_DEBUG"yaffs_mknod: could not get parent object\n"));
 440                 return -EPERM;
 441         }
 442
 443         T(("yaffs_mknod: making oject for %s, mode %x\n",
 444                                 dentry->d_name.name, mode));
 445
 446         switch (mode & S_IFMT)
 447         {
 448                 default:
 449
 450                         break;
 451                 case S_IFREG:   // file
 452                         T((KERN_DEBUG"yaffs_mknod: making file\n"));
 453                         obj = yaffs_MknodFile(parent,dentry->d_name.name,mode,current->uid, current->gid);
 454                         break;
 455                 case S_IFDIR:   // directory
 456                         T((KERN_DEBUG"yaffs_mknod: making directory\n"));
 457                         obj = yaffs_MknodDirectory(parent,dentry->d_name.name,mode,current->uid, current->gid);
 458                         break;
 459                 case S_IFLNK:   // symlink
 460                         T((KERN_DEBUG"yaffs_mknod: making file\n"));
 461                         obj = NULL; // Todo
 462                         break;
 463         }
 464
 465         if(obj)
 466         {
 467                 inode = yaffs_get_inode(dir->i_sb, mode, dev, obj);
 468
 469 // did not fix dir bug          if((mode & S_IFMT) == S_IFDIR)  atomic_inc(&inode->i_count);
 470
 471                 d_instantiate(dentry, inode);
 472                 T((KERN_DEBUG"yaffs_mknod created object %d count = %d\n",obj->objectId,atomic_read(&inode->i_count)));
 473                 error = 0;
 474         }
 475         else
 476         {
 477                 T((KERN_DEBUG"yaffs_mknod failed making object\n"));
 478                 error = -ENOMEM;
 479         }
 480
 481
 482         return error;
 483 }
 484
 485 static int yaffs_mkdir(struct inode * dir, struct dentry * dentry, int mode)
 486 {
 487         int retVal;
 488         T((KERN_DEBUG"yaffs_mkdir\n"));
 489         retVal =  yaffs_mknod(dir, dentry, mode | S_IFDIR, 0);
 490 #if 0
 491  // attempt to fix dir bug - didn't work
 492         if(!retVal)
 493         {
 494                 dget(dentry);
 495         }
 496 #endif
 497         return retVal;
 498 }
 499
 500 static int yaffs_create(struct inode *dir, struct dentry *dentry, int mode)
 501 {
 502         T((KERN_DEBUG"yaffs_create\n"));
 503         return yaffs_mknod(dir, dentry, mode | S_IFREG, 0);
 504 }
 505
 506
 507 static int yaffs_unlink(struct inode * dir, struct dentry *dentry)
 508 {
 509
 510         T((KERN_DEBUG"yaffs_unlink\n"));
 511
 512         if(yaffs_Unlink(yaffs_InodeToObject(dir),dentry->d_name.name) == YAFFS_OK)
 513         {
 514                 return 0;
 515         }
 516         else
 517         {
 518                 return -ENOTEMPTY;
 519         }
 520 }
 521
 522
 523 /*
 524  * Link a file..
 525  */
 526 static int yaffs_link(struct dentry *old_dentry, struct inode * dir, struct dentry * dentry)
 527 {
 528         struct inode *inode = old_dentry->d_inode;
 529
 530         T((KERN_DEBUG"yaffs_link\n"));
 531
 532         return -EPERM; //Todo
 533
 534
 535         if (S_ISDIR(inode->i_mode))
 536                 return -EPERM;
 537
 538
 539         return 0;
 540 }
 541
 542
 543 static int yaffs_symlink(struct inode * dir, struct dentry *dentry, const char * symname)
 544 {
 545         int error;
 546
 547         T((KERN_DEBUG"yaffs_symlink\n"));
 548
 549
 550         return -ENOMEM; //Todo
 551
 552         error = yaffs_mknod(dir, dentry, S_IFLNK | S_IRWXUGO, 0);
 553         return error;
 554 }
 555
 556 static int yaffs_sync_object(struct file * file, struct dentry *dentry, int datasync)
 557 {
 558
 559         T((KERN_DEBUG"yaffs_sync_object\n"));
 560         yaffs_FlushFile(yaffs_DentryToObject(dentry));
 561         return 0;
 562 }
 563
 564 /*
 565  * The VFS layer already does all the dentry stuff for rename.
 566  */
 567 static int yaffs_rename(struct inode * old_dir, struct dentry *old_dentry, struct inode * new_dir,struct dentry *new_dentry)
 568 {
 569
 570
 571         if( yaffs_RenameObject(yaffs_InodeToObject(old_dir),old_dentry->d_name.name,
 572                                yaffs_InodeToObject(new_dir),new_dentry->d_name.name) == YAFFS_OK)
 573         {
 574                 return 0;
 575         }
 576         else
 577         {
 578                 return -ENOTEMPTY;
 579         }
 580
 581
 582 }
 583
 584 static int yaffs_setattr(struct dentry *dentry, struct iattr *attr)
 585 {
 586         struct inode *inode = dentry->d_inode;
 587         int error;
 588
 589         T((KERN_DEBUG"yaffs_setattr\n"));
 590
 591         if((error = inode_change_ok(inode,attr)) == 0)
 592         {
 593
 594                 if(yaffs_SetAttributes(yaffs_InodeToObject(inode),attr) == YAFFS_OK)
 595                 {
 596                         error = 0;
 597                 }
 598                 else
 599                 {
 600                         error = -EPERM;
 601                 }
 602
 603                 inode_setattr(inode,attr);
 604         }
 605         return error;
 606 }
 607
 608 static int yaffs_statfs(struct super_block *sb, struct statfs *buf)
 609 {
 610         T((KERN_DEBUG"yaffs_statfs\n"));
 611
 612         buf->f_type = YAFFS_MAGIC;
 613         buf->f_bsize = YAFFS_BYTES_PER_CHUNK;
 614         buf->f_namelen = 255;
 615         buf->f_blocks = yaffs_SuperToDevice(sb)->nBlocks * YAFFS_CHUNKS_PER_BLOCK;
 616         buf->f_files = 0;
 617         buf->f_ffree = 0;
 618         buf->f_bavail = buf->f_bfree = yaffs_GetNumberOfFreeChunks(yaffs_SuperToDevice(sb));
 619         return 0;
 620 }
 621
 622 static void yaffs_read_inode (struct inode *inode)
 623 {
 624
 625         yaffs_Object *obj ;
 626
 627         T((KERN_DEBUG"yaffs_read_inode for %d\n",(int)inode->i_ino));
 628
 629         obj  = yaffs_FindObjectByNumber(yaffs_SuperToDevice(inode->i_sb),inode->i_ino);
 630
 631         yaffs_FillInodeFromObject(inode,obj);
 632 }
 633
 634
 635 static void yaffs_put_super(struct super_block *sb)
 636 {
 637         yaffs_Device *dev = yaffs_SuperToDevice(sb);
 638
 639         if(dev->putSuperFunc)
 640         {
 641                  dev->putSuperFunc(sb);
 642         }
 643 }
 644
 645
 646 #ifdef YAFFS_MTD_ENABLED
 647
 648 static void  yaffs_MTDPutSuper(struct super_block *sb)
 649 {
 650
 651         struct mtd_info *mtd = yaffs_SuperToDevice(sb)->genericDevice;
 652
 653         if(mtd->sync)
 654         {
 655                 mtd->sync(mtd);
 656         }
 657
 658         put_mtd_device(mtd);
 659 }
 660
 661 #endif
 662
 663 static struct super_block *yaffs_internal_read_super(int useRam, struct super_block * sb, void * data, int silent)
 664 {
 665         struct inode * inode;
 666         struct dentry * root;
 667         yaffs_Device *dev;
 668
 669
 670         T(("yaffs_read_super: %s\n", useRam ? "RAM" : "MTD"));
 671         sb->s_blocksize = YAFFS_BYTES_PER_CHUNK;
 672         sb->s_blocksize_bits = YAFFS_CHUNK_SIZE_SHIFT;
 673         sb->s_magic = YAFFS_MAGIC;
 674         sb->s_op = &yaffs_super_ops;
 675
 676         if(!sb)
 677                 printk(KERN_INFO"yaffs: sb is NULL\n");
 678         else if(!sb->s_dev)
 679                 printk(KERN_INFO"yaffs: sb->s_dev is NULL\n");
 680         else if(! kdevname(sb->s_dev))
 681                 printk(KERN_INFO"yaffs: kdevname is NULL\n");
 682         else
 683                 printk(KERN_INFO"yaffs: dev is %d name is \"%s\"\n", sb->s_dev, kdevname(sb->s_dev));
 684
 685
 686
 687         if(useRam)
 688         {
 689
 690 #ifdef YAFFS_RAM_ENABLED
 691                 // Set the yaffs_Device up for ram emulation
 692
 693                 sb->u.generic_sbp =     dev = kmalloc(sizeof(yaffs_Device),GFP_KERNEL);
 694                 if(!dev)
 695                 {
 696                         // Deep shit could not allocate device structure
 697                         printk(KERN_DEBUG"yaffs_read_super: Failed trying to allocate yaffs_Device. Terminating debug.\n");
 698                         return NULL;
 699                 }
 700
 701                 memset(dev,0,sizeof(yaffs_Device));
 702                 dev->genericDevice = NULL; // Not used for RAM emulation.
 703
 704                 dev->nBlocks = YAFFS_RAM_EMULATION_SIZE / (YAFFS_CHUNKS_PER_BLOCK * YAFFS_BYTES_PER_CHUNK);
 705                 dev->startBlock = 1;  // Don't use block 0
 706                 dev->endBlock = dev->nBlocks - 1;
 707
 708                 dev->writeChunkToNAND = nandemul_WriteChunkToNAND;
 709                 dev->readChunkFromNAND = nandemul_ReadChunkFromNAND;
 710                 dev->eraseBlockInNAND = nandemul_EraseBlockInNAND;
 711                 dev->initialiseNAND = nandemul_InitialiseNAND;
 712
 713 #endif
 714
 715         }
 716         else
 717         {
 718 #ifdef YAFFS_MTD_ENABLED
 719                 struct mtd_info *mtd;
 720
 721                 printk(KERN_DEBUG "yaffs: Attempting MTD mount on %u.%u, \"%s\"\n",
 722                  MAJOR(sb->s_dev),MINOR(sb->s_dev),kdevname(sb->s_dev));
 723
 724                 // Hope it's a NAND mtd
 725                 mtd = get_mtd_device(NULL, MINOR(sb->s_dev));
 726                 if (!mtd)
 727                 {
 728                         printk(KERN_DEBUG "yaffs: MTD device #%u doesn't appear to exist\n", MINOR(sb->s_dev));
 729                         return NULL;
 730                 }
 731
 732                 if(mtd->type != MTD_NANDFLASH)
 733                 {
 734                         printk(KERN_DEBUG "yaffs: MTD device is not NAND it's type %d\n", mtd->type);
 735                         return NULL;
 736                 }
 737
 738                 printk(KERN_DEBUG" erase %x\n",mtd->erase);
 739                 printk(KERN_DEBUG" read %x\n",mtd->read);
 740                 printk(KERN_DEBUG" write %x\n",mtd->write);
 741                 printk(KERN_DEBUG" readoob %x\n",mtd->read_oob);
 742                 printk(KERN_DEBUG" writeoob %x\n",mtd->write_oob);
 743                 printk(KERN_DEBUG" oobblock %x\n",mtd->oobblock);
 744                 printk(KERN_DEBUG" oobsize %x\n",mtd->oobsize);
 745
 746
 747                 if(!mtd->erase ||
 748                    !mtd->read  ||
 749                    !mtd->write ||
 750                    !mtd->read_oob ||
 751                    !mtd->write_oob)
 752                 {
 753                         printk(KERN_DEBUG "yaffs: MTD device does not support required functions\n");
 754                         return NULL;
 755                 }
 756
 757                 if(mtd->oobblock != YAFFS_BYTES_PER_CHUNK ||
 758                    mtd->oobsize != YAFFS_BYTES_PER_SPARE)
 759                 {
 760                         printk(KERN_DEBUG "yaffs: MTD device does not support have the right page sizes\n");
 761                         return NULL;
 762                 }
 763
 764
 765                 // OK, so if we got here, we have an MTD that's NAND and looks
 766                 // like it has the right capabilities
 767                 // Set the yaffs_Device up for ram emulation
 768
 769                 sb->u.generic_sbp =     dev = kmalloc(sizeof(yaffs_Device),GFP_KERNEL);
 770                 if(!dev)
 771                 {
 772                         // Deep shit could not allocate device structure
 773                         printk(KERN_DEBUG"yaffs_read_super: Failed trying to allocate yaffs_Device. Terminating debug.\n");
 774                         return NULL;
 775                 }
 776
 777                 memset(dev,0,sizeof(yaffs_Device));
 778                 dev->genericDevice = mtd;
 779
 780                 // Set up the memory size parameters....
 781
 782 // NCB          dev->nBlocks = YAFFS_RAM_EMULATION_SIZE / (YAFFS_CHUNKS_PER_BLOCK * YAFFS_BYTES_PER_CHUNK);
 783                 dev->nBlocks = mtd->size / (YAFFS_CHUNKS_PER_BLOCK * YAFFS_BYTES_PER_CHUNK);
 784                 dev->startBlock = 1;  // Don't use block 0
 785                 dev->endBlock = dev->nBlocks - 1;
 786
 787                 // ... and the functions.
 788                 dev->writeChunkToNAND = nandmtd_WriteChunkToNAND;
 789                 dev->readChunkFromNAND = nandmtd_ReadChunkFromNAND;
 790                 dev->eraseBlockInNAND = nandmtd_EraseBlockInNAND;
 791                 dev->initialiseNAND = nandmtd_InitialiseNAND;
 792
 793                 dev->putSuperFunc = yaffs_MTDPutSuper;
 794 #endif
 795         }
 796
 797
 798
 799         yaffs_GutsInitialise(yaffs_SuperToDevice(sb));
 800         T(("yaffs_read_super: guts initialised\n"));
 801
 802         // Create root inode
 803         inode = yaffs_get_inode(sb, S_IFDIR | 0755, 0,yaffs_Root(yaffs_SuperToDevice(sb)));
 804         if (!inode)
 805                 return NULL;
 806
 807         T(("yaffs_read_super: got root inode\n"));
 808
 809
 810         root = d_alloc_root(inode);
 811
 812         T(("yaffs_read_super: d_alloc_root done\n"));
 813
 814         if (!root) {
 815                 iput(inode);
 816                 return NULL;
 817         }
 818         sb->s_root = root;
 819
 820         T(("yaffs_read_super: done\n"));
 821         return sb;
 822 }
 823
 824 #ifdef YAFFS_MTD_ENABLED
 825 static struct super_block *yaffs_read_super(struct super_block * sb, void * data, int silent)
 826 {
 827         return yaffs_internal_read_super(0,sb,data,silent);
 828 }
 829
 830 static DECLARE_FSTYPE(yaffs_fs_type, "yaffs", yaffs_read_super, FS_REQUIRES_DEV);
 831 #endif
 832
 833 #ifdef YAFFS_RAM_ENABLED
 834
 835 static struct super_block *yaffs_ram_read_super(struct super_block * sb, void * data, int silent)
 836 {
 837         return yaffs_internal_read_super(1,sb,data,silent);
 838 }
 839
 840 static DECLARE_FSTYPE(yaffs_ram_fs_type, "yaffsram", yaffs_ram_read_super, FS_SINGLE);
 841 #endif // YAFFS_RAM_ENABLED
 842
 843
 844 static struct proc_dir_entry *my_proc_entry;
 845
 846
 847 static int  yaffs_proc_read(
 848         char *page,
 849         char **start,
 850         off_t offset,
 851         int count,
 852         int *eof,
 853         void *data
 854         )
 855 {
 856
 857         static char my_buffer[1000];
 858
 859         if (offset > 0) return 0;
 860
 861         /* Fill the buffer and get its length */
 862         sprintf( my_buffer,
 863                 "YAFFS built:"__DATE__ " "__TIME__"\n"
 864
 865         );
 866
 867         strcpy(page,my_buffer);
 868         return strlen(my_buffer);
 869 }
 870
 871 static int __init init_yaffs_fs(void)
 872 {
 873         int error = 0;
 874
 875         printk(KERN_DEBUG "yaffs " __DATE__ " " __TIME__ " Initialisation\n");
 876     /* Install the proc_fs entry */
 877     my_proc_entry = create_proc_read_entry("yaffs",
 878                                            S_IRUGO | S_IFREG,
 879                                            &proc_root,
 880                                            yaffs_proc_read,
 881                                            NULL);
 882     if(!my_proc_entry)
 883     {
 884        return -ENOMEM;
 885     }
 886
 887 #ifdef YAFFS_RAM_ENABLED
 888
 889     error = register_filesystem(&yaffs_ram_fs_type);
 890     if(error)
 891     {
 892         return error;
 893     }
 894 #endif //YAFFS_RAM_ENABLED
 895
 896 #ifdef YAFFS_MTD_ENABLED
 897         error = register_filesystem(&yaffs_fs_type);
 898         if(error)
 899         {
 900 #ifdef YAFFS_RAM_ENABLED
 901                 unregister_filesystem(&yaffs_ram_fs_type);
 902 #endif //YAFFS_RAM_ENABLED
 903         }
 904 #endif // YAFFS_MTD_ENABLED
 905
 906         return error;
 907 }
 908
 909 static void __exit exit_yaffs_fs(void)
 910 {
 911         printk(KERN_DEBUG "yaffs " __DATE__ " " __TIME__ " Clean up\n");
 912
 913     remove_proc_entry("yaffs",&proc_root);
 914
 915 #ifdef YAFFS_RAM_ENABLED
 916         unregister_filesystem(&yaffs_ram_fs_type);
 917 #endif
 918 #ifdef YAFFS_MTD_ENABLED
 919         unregister_filesystem(&yaffs_fs_type);
 920 #endif
 921
 922 }
 923
 924 module_init(init_yaffs_fs)
 925 module_exit(exit_yaffs_fs)
 926
 927 MODULE_DESCRIPTION("YAFFS - a NAND specific flash file system");
 928 MODULE_AUTHOR("Charles Manning, Aleph One Ltd., 2002");
 929 MODULE_LICENSE("GPL");
 930