yaffs_vfs_single.c

   1 /*
   2  * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
   3  *
   4  * Copyright (C) 2002-2011 Aleph One Ltd.
   5  *   for Toby Churchill Ltd and Brightstar Engineering
   6  *
   7  * Created by Charles Manning <charles@aleph1.co.uk>
   8  * Acknowledgements:
   9  * Luc van OostenRyck for numerous patches.
  10  * Nick Bane for numerous patches.
  11  * Nick Bane for 2.5/2.6 integration.
  12  * Andras Toth for mknod rdev issue.
  13  * Michael Fischer for finding the problem with inode inconsistency.
  14  * Some code bodily lifted from JFFS
  15  *
  16  * This program is free software; you can redistribute it and/or modify
  17  * it under the terms of the GNU General Public License version 2 as
  18  * published by the Free Software Foundation.
  19  */
  20
  21 /*
  22  *
  23  * This is the file system front-end to YAFFS that hooks it up to
  24  * the VFS.
  25  *
  26  * Special notes:
  27  * >> 2.4: sb->u.generic_sbp points to the struct yaffs_dev associated with
  28  *         this superblock
  29  * >> 2.6: sb->s_fs_info  points to the struct yaffs_dev associated with this
  30  *         superblock
  31  * >> inode->u.generic_ip points to the associated struct yaffs_obj.
  32  */
  33
  34 /*
  35  * NB There are two variants of Linux VFS glue code. This variant supports
  36  * a single version and should not include any multi-version code.
  37  */
  38 #include <linux/version.h>
  39 #include <linux/kernel.h>
  40 #include <linux/module.h>
  41 #include <linux/slab.h>
  42 #include <linux/init.h>
  43 #include <linux/fs.h>
  44 #include <linux/proc_fs.h>
  45 #include <linux/pagemap.h>
  46 #include <linux/mtd/mtd.h>
  47 #include <linux/interrupt.h>
  48 #include <linux/string.h>
  49 #include <linux/ctype.h>
  50 #include <linux/namei.h>
  51 #include <linux/exportfs.h>
  52 #include <linux/kthread.h>
  53 #include <linux/delay.h>
  54 #include <linux/freezer.h>
  55 #include <asm/div64.h>
  56 #include <linux/statfs.h>
  57 #include <linux/uaccess.h>
  58 #include <linux/mtd/mtd.h>
  59
  60 #include "yportenv.h"
  61 #include "yaffs_trace.h"
  62 #include "yaffs_guts.h"
  63 #include "yaffs_attribs.h"
  64 #include "yaffs_linux.h"
  65 #include "yaffs_mtdif.h"
  66 #include "yaffs_mtdif1.h"
  67 #include "yaffs_mtdif2.h"
  68
  69 unsigned int yaffs_trace_mask = YAFFS_TRACE_BAD_BLOCKS | YAFFS_TRACE_ALWAYS;
  70 unsigned int yaffs_wr_attempts = YAFFS_WR_ATTEMPTS;
  71 unsigned int yaffs_auto_checkpoint = 1;
  72 unsigned int yaffs_gc_control = 1;
  73 unsigned int yaffs_bg_enable = 1;
  74 unsigned int yaffs_auto_select = 1;
  75
  76 /* Module Parameters */
  77 module_param(yaffs_trace_mask, uint, 0644);
  78 module_param(yaffs_wr_attempts, uint, 0644);
  79 module_param(yaffs_auto_checkpoint, uint, 0644);
  80 module_param(yaffs_gc_control, uint, 0644);
  81 module_param(yaffs_bg_enable, uint, 0644);
  82 module_param(yaffs_auto_select, uint, 0644);
  83
  84 #define yaffs_devname(sb, buf)  bdevname(sb->s_bdev, buf)
  85
  86 static uint32_t YCALCBLOCKS(uint64_t partition_size, uint32_t block_size)
  87 {
  88         uint64_t result = partition_size;
  89
  90         do_div(result, block_size);
  91         return (uint32_t) result;
  92 }
  93
  94 #define yaffs_inode_to_obj_lv(iptr) ((iptr)->i_private)
  95 #define yaffs_inode_to_obj(iptr)\
  96         ((struct yaffs_obj *)(yaffs_inode_to_obj_lv(iptr)))
  97 #define yaffs_dentry_to_obj(dptr) yaffs_inode_to_obj((dptr)->d_inode)
  98 #define yaffs_super_to_dev(sb)  ((struct yaffs_dev *)sb->s_fs_info)
  99
 100 #define update_dir_time(dir) do {\
 101                         (dir)->i_ctime = (dir)->i_mtime = CURRENT_TIME; \
 102                 } while (0)
 103
 104
 105 static unsigned yaffs_gc_control_callback(struct yaffs_dev *dev)
 106 {
 107         return yaffs_gc_control;
 108 }
 109
 110 static void yaffs_gross_lock(struct yaffs_dev *dev)
 111 {
 112         yaffs_trace(YAFFS_TRACE_LOCK, "yaffs locking %p", current);
 113         mutex_lock(&(yaffs_dev_to_lc(dev)->gross_lock));
 114         yaffs_trace(YAFFS_TRACE_LOCK, "yaffs locked %p", current);
 115 }
 116
 117 static void yaffs_gross_unlock(struct yaffs_dev *dev)
 118 {
 119         yaffs_trace(YAFFS_TRACE_LOCK, "yaffs unlocking %p", current);
 120         mutex_unlock(&(yaffs_dev_to_lc(dev)->gross_lock));
 121 }
 122
 123 static void yaffs_fill_inode_from_obj(struct inode *inode,
 124                                       struct yaffs_obj *obj);
 125
 126 static struct inode *yaffs_iget(struct super_block *sb, unsigned long ino)
 127 {
 128         struct inode *inode;
 129         struct yaffs_obj *obj;
 130         struct yaffs_dev *dev = yaffs_super_to_dev(sb);
 131
 132         yaffs_trace(YAFFS_TRACE_OS, "yaffs_iget for %lu", ino);
 133
 134         inode = iget_locked(sb, ino);
 135         if (!inode)
 136                 return ERR_PTR(-ENOMEM);
 137         if (!(inode->i_state & I_NEW))
 138                 return inode;
 139
 140         /* NB This is called as a side effect of other functions, but
 141          * we had to release the lock to prevent deadlocks, so
 142          * need to lock again.
 143          */
 144
 145         yaffs_gross_lock(dev);
 146
 147         obj = yaffs_find_by_number(dev, inode->i_ino);
 148         yaffs_fill_inode_from_obj(inode, obj);
 149
 150         yaffs_gross_unlock(dev);
 151
 152         unlock_new_inode(inode);
 153         return inode;
 154 }
 155
 156 struct inode *yaffs_get_inode(struct super_block *sb, int mode, int dev,
 157                               struct yaffs_obj *obj)
 158 {
 159         struct inode *inode;
 160
 161         if (!sb) {
 162                 yaffs_trace(YAFFS_TRACE_OS,
 163                         "yaffs_get_inode for NULL super_block!!");
 164                 return NULL;
 165
 166         }
 167
 168         if (!obj) {
 169                 yaffs_trace(YAFFS_TRACE_OS,
 170                         "yaffs_get_inode for NULL object!!");
 171                 return NULL;
 172
 173         }
 174
 175         yaffs_trace(YAFFS_TRACE_OS,
 176                 "yaffs_get_inode for object %d",
 177                 obj->obj_id);
 178
 179         inode = yaffs_iget(sb, obj->obj_id);
 180         if (IS_ERR(inode))
 181                 return NULL;
 182
 183         /* NB Side effect: iget calls back to yaffs_read_inode(). */
 184         /* iget also increments the inode's i_count */
 185         /* NB You can't be holding gross_lock or deadlock will happen! */
 186
 187         return inode;
 188 }
 189
 190 static int yaffs_mknod(struct inode *dir, struct dentry *dentry, int mode,
 191                        dev_t rdev)
 192 {
 193         struct inode *inode;
 194         struct yaffs_obj *obj = NULL;
 195         struct yaffs_dev *dev;
 196         struct yaffs_obj *parent = yaffs_inode_to_obj(dir);
 197         int error;
 198         uid_t uid = current->cred->fsuid;
 199         gid_t gid =
 200             (dir->i_mode & S_ISGID) ? dir->i_gid : current->cred->fsgid;
 201
 202         if ((dir->i_mode & S_ISGID) && S_ISDIR(mode))
 203                 mode |= S_ISGID;
 204
 205         if (!parent) {
 206                 yaffs_trace(YAFFS_TRACE_OS,
 207                         "yaffs_mknod: could not get parent object");
 208                 return -EPERM;
 209         }
 210
 211         yaffs_trace(YAFFS_TRACE_OS,
 212                         "yaffs_mknod: parent object %d type %d",
 213                         parent->obj_id, parent->variant_type);
 214
 215         yaffs_trace(YAFFS_TRACE_OS,
 216                 "yaffs_mknod: making oject for %s, mode %x dev %x",
 217                 dentry->d_name.name, mode, rdev);
 218
 219         dev = parent->my_dev;
 220
 221         yaffs_gross_lock(dev);
 222
 223         if (yaffs_get_n_free_chunks(dev) < 1) {
 224                 error = -ENOSPC;
 225                 goto err_out;
 226         }
 227
 228         switch (mode & S_IFMT) {
 229         default:
 230                 /* Special (socket, fifo, device...) */
 231                 yaffs_trace(YAFFS_TRACE_OS, "yaffs_mknod: making special");
 232                 obj =
 233                     yaffs_create_special(parent, dentry->d_name.name, mode, uid,
 234                                          gid, old_encode_dev(rdev));
 235                 break;
 236         case S_IFREG:           /* file          */
 237                 yaffs_trace(YAFFS_TRACE_OS, "yaffs_mknod: making file");
 238                 obj = yaffs_create_file(parent, dentry->d_name.name, mode, uid,
 239                                         gid);
 240                 break;
 241         case S_IFDIR:           /* directory */
 242                 yaffs_trace(YAFFS_TRACE_OS, "yaffs_mknod: making directory");
 243                 obj = yaffs_create_dir(parent, dentry->d_name.name, mode,
 244                                        uid, gid);
 245                 break;
 246         case S_IFLNK:           /* symlink */
 247                 yaffs_trace(YAFFS_TRACE_OS, "yaffs_mknod: making symlink");
 248                 obj = NULL;     /* Do we ever get here? */
 249                 break;
 250         }
 251
 252         if (!obj) {
 253                 error = -ENOMEM;
 254                 goto err_out;
 255         }
 256
 257         /* Can not call yaffs_get_inode() with gross lock held */
 258         yaffs_gross_unlock(dev);
 259
 260
 261         inode = yaffs_get_inode(dir->i_sb, mode, rdev, obj);
 262         d_instantiate(dentry, inode);
 263         update_dir_time(dir);
 264         yaffs_trace(YAFFS_TRACE_OS,
 265                 "yaffs_mknod created object %d count = %d",
 266                 obj->obj_id, atomic_read(&inode->i_count));
 267         yaffs_fill_inode_from_obj(dir, parent);
 268         return 0;
 269
 270 err_out:
 271         yaffs_gross_unlock(dev);
 272         yaffs_trace(YAFFS_TRACE_OS, "yaffs_mknod error %d", error);
 273         return error;
 274
 275 }
 276
 277 static int yaffs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 278 {
 279         return yaffs_mknod(dir, dentry, mode | S_IFDIR, 0);
 280 }
 281
 282 static int yaffs_create(struct inode *dir, struct dentry *dentry, int mode,
 283                         struct nameidata *n)
 284 {
 285         return yaffs_mknod(dir, dentry, mode | S_IFREG, 0);
 286 }
 287
 288 static int yaffs_link(struct dentry *old_dentry, struct inode *dir,
 289                       struct dentry *dentry)
 290 {
 291         struct inode *inode = old_dentry->d_inode;
 292         struct yaffs_obj *obj = NULL;
 293         struct yaffs_obj *link = NULL;
 294         struct yaffs_dev *dev;
 295
 296         yaffs_trace(YAFFS_TRACE_OS, "yaffs_link");
 297
 298         obj = yaffs_inode_to_obj(inode);
 299         dev = obj->my_dev;
 300
 301         yaffs_gross_lock(dev);
 302
 303         if (!S_ISDIR(inode->i_mode))    /* Don't link directories */
 304                 link =
 305                     yaffs_link_obj(yaffs_inode_to_obj(dir), dentry->d_name.name,
 306                                    obj);
 307
 308         if (link) {
 309                 set_nlink(old_dentry->d_inode, yaffs_get_obj_link_count(obj));
 310                 d_instantiate(dentry, old_dentry->d_inode);
 311                 atomic_inc(&old_dentry->d_inode->i_count);
 312                 yaffs_trace(YAFFS_TRACE_OS,
 313                         "yaffs_link link count %d i_count %d",
 314                         old_dentry->d_inode->i_nlink,
 315                         atomic_read(&old_dentry->d_inode->i_count));
 316         }
 317
 318         yaffs_gross_unlock(dev);
 319
 320         if (link) {
 321                 update_dir_time(dir);
 322                 return 0;
 323         }
 324
 325         return -EPERM;
 326 }
 327
 328 static int yaffs_symlink(struct inode *dir, struct dentry *dentry,
 329                          const char *symname)
 330 {
 331         struct yaffs_obj *obj;
 332         struct yaffs_dev *dev;
 333         struct inode *inode;
 334         uid_t uid = current->cred->fsuid;
 335         gid_t gid =
 336             (dir->i_mode & S_ISGID) ? dir->i_gid : current->cred->fsgid;
 337
 338         yaffs_trace(YAFFS_TRACE_OS, "yaffs_symlink");
 339
 340         if (strnlen(dentry->d_name.name, YAFFS_MAX_NAME_LENGTH + 1) >
 341                                 YAFFS_MAX_NAME_LENGTH)
 342                 return -ENAMETOOLONG;
 343
 344         if (strnlen(symname, YAFFS_MAX_ALIAS_LENGTH + 1) >
 345                                 YAFFS_MAX_ALIAS_LENGTH)
 346                 return -ENAMETOOLONG;
 347
 348         dev = yaffs_inode_to_obj(dir)->my_dev;
 349         yaffs_gross_lock(dev);
 350         obj = yaffs_create_symlink(yaffs_inode_to_obj(dir), dentry->d_name.name,
 351                                    S_IFLNK | S_IRWXUGO, uid, gid, symname);
 352         yaffs_gross_unlock(dev);
 353
 354         if (!obj) {
 355                 yaffs_trace(YAFFS_TRACE_OS, "symlink not created");
 356                 return -ENOMEM;
 357         }
 358
 359         inode = yaffs_get_inode(dir->i_sb, obj->yst_mode, 0, obj);
 360         d_instantiate(dentry, inode);
 361         update_dir_time(dir);
 362         yaffs_trace(YAFFS_TRACE_OS, "symlink created OK");
 363
 364         return 0;
 365 }
 366
 367 static struct dentry *yaffs_lookup(struct inode *dir, struct dentry *dentry,
 368                                    struct nameidata *n)
 369 {
 370         struct yaffs_obj *obj;
 371         struct inode *inode = NULL;
 372         struct yaffs_dev *dev = yaffs_inode_to_obj(dir)->my_dev;
 373
 374         if (current != yaffs_dev_to_lc(dev)->readdir_process)
 375                 yaffs_gross_lock(dev);
 376
 377         yaffs_trace(YAFFS_TRACE_OS,
 378                 "yaffs_lookup for %d:%s",
 379                 yaffs_inode_to_obj(dir)->obj_id, dentry->d_name.name);
 380
 381         obj = yaffs_find_by_name(yaffs_inode_to_obj(dir), dentry->d_name.name);
 382
 383         obj = yaffs_get_equivalent_obj(obj);    /* in case it was a hardlink */
 384
 385         /* Can't hold gross lock when calling yaffs_get_inode() */
 386         if (current != yaffs_dev_to_lc(dev)->readdir_process)
 387                 yaffs_gross_unlock(dev);
 388
 389         if (obj) {
 390                 yaffs_trace(YAFFS_TRACE_OS,
 391                         "yaffs_lookup found %d", obj->obj_id);
 392
 393                 inode = yaffs_get_inode(dir->i_sb, obj->yst_mode, 0, obj);
 394
 395                 if (inode) {
 396                         yaffs_trace(YAFFS_TRACE_OS, "yaffs_loookup dentry");
 397                         d_add(dentry, inode);
 398                         /* return dentry; */
 399                         return NULL;
 400                 }
 401
 402         } else {
 403                 yaffs_trace(YAFFS_TRACE_OS, "yaffs_lookup not found");
 404
 405         }
 406
 407         d_add(dentry, inode);
 408
 409         return NULL;
 410 }
 411
 412 static int yaffs_unlink(struct inode *dir, struct dentry *dentry)
 413 {
 414         int ret_val;
 415         struct yaffs_dev *dev;
 416         struct yaffs_obj *obj;
 417
 418         yaffs_trace(YAFFS_TRACE_OS,
 419                 "yaffs_unlink %d:%s",
 420                 (int)(dir->i_ino), dentry->d_name.name);
 421         obj = yaffs_inode_to_obj(dir);
 422         dev = obj->my_dev;
 423
 424         yaffs_gross_lock(dev);
 425
 426         ret_val = yaffs_unlinker(obj, dentry->d_name.name);
 427
 428         if (ret_val == YAFFS_OK) {
 429                 inode_dec_link_count(dentry->d_inode);
 430                 dir->i_version++;
 431                 yaffs_gross_unlock(dev);
 432                 update_dir_time(dir);
 433                 return 0;
 434         }
 435         yaffs_gross_unlock(dev);
 436         return -ENOTEMPTY;
 437 }
 438
 439 static int yaffs_sync_object(struct file *file, loff_t start, loff_t end, int datasync)
 440 {
 441
 442         struct yaffs_obj *obj;
 443         struct yaffs_dev *dev;
 444         struct dentry *dentry = file->f_path.dentry;
 445
 446         obj = yaffs_dentry_to_obj(dentry);
 447
 448         dev = obj->my_dev;
 449
 450         yaffs_trace(YAFFS_TRACE_OS | YAFFS_TRACE_SYNC, "yaffs_sync_object");
 451         yaffs_gross_lock(dev);
 452         yaffs_flush_file(obj, 1, datasync);
 453         yaffs_gross_unlock(dev);
 454         return 0;
 455 }
 456 /*
 457  * The VFS layer already does all the dentry stuff for rename.
 458  *
 459  * NB: POSIX says you can rename an object over an old object of the same name
 460  */
 461 static int yaffs_rename(struct inode *old_dir, struct dentry *old_dentry,
 462                         struct inode *new_dir, struct dentry *new_dentry)
 463 {
 464         struct yaffs_dev *dev;
 465         int ret_val = YAFFS_FAIL;
 466         struct yaffs_obj *target;
 467
 468         yaffs_trace(YAFFS_TRACE_OS, "yaffs_rename");
 469         dev = yaffs_inode_to_obj(old_dir)->my_dev;
 470
 471         yaffs_gross_lock(dev);
 472
 473         /* Check if the target is an existing directory that is not empty. */
 474         target = yaffs_find_by_name(yaffs_inode_to_obj(new_dir),
 475                                     new_dentry->d_name.name);
 476
 477         if (target && target->variant_type == YAFFS_OBJECT_TYPE_DIRECTORY &&
 478             !list_empty(&target->variant.dir_variant.children)) {
 479
 480                 yaffs_trace(YAFFS_TRACE_OS, "target is non-empty dir");
 481
 482                 ret_val = YAFFS_FAIL;
 483         } else {
 484                 /* Now does unlinking internally using shadowing mechanism */
 485                 yaffs_trace(YAFFS_TRACE_OS, "calling yaffs_rename_obj");
 486
 487                 ret_val = yaffs_rename_obj(yaffs_inode_to_obj(old_dir),
 488                                            old_dentry->d_name.name,
 489                                            yaffs_inode_to_obj(new_dir),
 490                                            new_dentry->d_name.name);
 491         }
 492         yaffs_gross_unlock(dev);
 493
 494         if (ret_val == YAFFS_OK) {
 495                 if (target)
 496                         inode_dec_link_count(new_dentry->d_inode);
 497
 498                 update_dir_time(old_dir);
 499                 if (old_dir != new_dir)
 500                         update_dir_time(new_dir);
 501                 return 0;
 502         } else {
 503                 return -ENOTEMPTY;
 504         }
 505 }
 506
 507 static int yaffs_setattr(struct dentry *dentry, struct iattr *attr)
 508 {
 509         struct inode *inode = dentry->d_inode;
 510         int error = 0;
 511         struct yaffs_dev *dev;
 512         int result;
 513
 514         yaffs_trace(YAFFS_TRACE_OS,
 515                 "yaffs_setattr of object %d",
 516                 yaffs_inode_to_obj(inode)->obj_id);
 517
 518         /* Fail if a requested resize >= 2GB */
 519         if (attr->ia_valid & ATTR_SIZE && (attr->ia_size >> 31))
 520                 error = -EINVAL;
 521
 522         if (!error)
 523                 error = inode_change_ok(inode, attr);
 524
 525         if (!error) {
 526                 setattr_copy(inode, attr);
 527                 yaffs_trace(YAFFS_TRACE_OS, "inode_setattr called");
 528                 if (attr->ia_valid & ATTR_SIZE) {
 529                         truncate_setsize(inode, attr->ia_size);
 530                         inode->i_blocks = (inode->i_size + 511) >> 9;
 531                 }
 532                 dev = yaffs_inode_to_obj(inode)->my_dev;
 533                 if (attr->ia_valid & ATTR_SIZE) {
 534                         yaffs_trace(YAFFS_TRACE_OS, "resize to %d(%x)",
 535                                            (int)(attr->ia_size),
 536                                            (int)(attr->ia_size));
 537                 }
 538
 539                 yaffs_gross_lock(dev);
 540                 result = yaffs_set_attribs(yaffs_inode_to_obj(inode), attr);
 541                 if (result != YAFFS_OK)
 542                         error = -EPERM;
 543                 yaffs_gross_unlock(dev);
 544         }
 545
 546         yaffs_trace(YAFFS_TRACE_OS, "yaffs_setattr done returning %d", error);
 547
 548         return error;
 549 }
 550
 551 static int yaffs_setxattr(struct dentry *dentry, const char *name,
 552                    const void *value, size_t size, int flags)
 553 {
 554         struct inode *inode = dentry->d_inode;
 555         int error;
 556         struct yaffs_dev *dev;
 557         struct yaffs_obj *obj = yaffs_inode_to_obj(inode);
 558
 559         yaffs_trace(YAFFS_TRACE_OS, "yaffs_setxattr of object %d", obj->obj_id);
 560
 561         dev = obj->my_dev;
 562         yaffs_gross_lock(dev);
 563         error = yaffs_set_xattrib(obj, name, value, size, flags);
 564         yaffs_gross_unlock(dev);
 565
 566         yaffs_trace(YAFFS_TRACE_OS, "yaffs_setxattr done returning %d", error);
 567
 568         return error;
 569 }
 570
 571 static ssize_t yaffs_getxattr(struct dentry *dentry, const char *name,
 572                                 void *buff, size_t size)
 573 {
 574         struct inode *inode = dentry->d_inode;
 575         int error;
 576         struct yaffs_dev *dev;
 577         struct yaffs_obj *obj = yaffs_inode_to_obj(inode);
 578
 579         yaffs_trace(YAFFS_TRACE_OS,
 580                 "yaffs_getxattr \"%s\" from object %d",
 581                 name, obj->obj_id);
 582
 583         dev = obj->my_dev;
 584         yaffs_gross_lock(dev);
 585         error = yaffs_get_xattrib(obj, name, buff, size);
 586         yaffs_gross_unlock(dev);
 587
 588         yaffs_trace(YAFFS_TRACE_OS, "yaffs_getxattr done returning %d", error);
 589
 590         return error;
 591 }
 592
 593 static int yaffs_removexattr(struct dentry *dentry, const char *name)
 594 {
 595         struct inode *inode = dentry->d_inode;
 596         int error;
 597         struct yaffs_dev *dev;
 598         struct yaffs_obj *obj = yaffs_inode_to_obj(inode);
 599
 600         yaffs_trace(YAFFS_TRACE_OS,
 601                 "yaffs_removexattr of object %d", obj->obj_id);
 602
 603         dev = obj->my_dev;
 604         yaffs_gross_lock(dev);
 605         error = yaffs_remove_xattrib(obj, name);
 606         yaffs_gross_unlock(dev);
 607
 608         yaffs_trace(YAFFS_TRACE_OS,
 609                 "yaffs_removexattr done returning %d", error);
 610
 611         return error;
 612 }
 613
 614 static ssize_t yaffs_listxattr(struct dentry *dentry, char *buff, size_t size)
 615 {
 616         struct inode *inode = dentry->d_inode;
 617         int error;
 618         struct yaffs_dev *dev;
 619         struct yaffs_obj *obj = yaffs_inode_to_obj(inode);
 620
 621         yaffs_trace(YAFFS_TRACE_OS,
 622                 "yaffs_listxattr of object %d", obj->obj_id);
 623
 624         dev = obj->my_dev;
 625         yaffs_gross_lock(dev);
 626         error = yaffs_list_xattrib(obj, buff, size);
 627         yaffs_gross_unlock(dev);
 628
 629         yaffs_trace(YAFFS_TRACE_OS,
 630                 "yaffs_listxattr done returning %d", error);
 631
 632         return error;
 633 }
 634
 635 static const struct inode_operations yaffs_dir_inode_operations = {
 636         .create = yaffs_create,
 637         .lookup = yaffs_lookup,
 638         .link = yaffs_link,
 639         .unlink = yaffs_unlink,
 640         .symlink = yaffs_symlink,
 641         .mkdir = yaffs_mkdir,
 642         .rmdir = yaffs_unlink,
 643         .mknod = yaffs_mknod,
 644         .rename = yaffs_rename,
 645         .setattr = yaffs_setattr,
 646         .setxattr = yaffs_setxattr,
 647         .getxattr = yaffs_getxattr,
 648         .listxattr = yaffs_listxattr,
 649         .removexattr = yaffs_removexattr,
 650 };
 651 /*-----------------------------------------------------------------*/
 652 /* Directory search context allows us to unlock access to yaffs during
 653  * filldir without causing problems with the directory being modified.
 654  * This is similar to the tried and tested mechanism used in yaffs direct.
 655  *
 656  * A search context iterates along a doubly linked list of siblings in the
 657  * directory. If the iterating object is deleted then this would corrupt
 658  * the list iteration, likely causing a crash. The search context avoids
 659  * this by using the remove_obj_fn to move the search context to the
 660  * next object before the object is deleted.
 661  *
 662  * Many readdirs (and thus seach conexts) may be alive simulateously so
 663  * each struct yaffs_dev has a list of these.
 664  *
 665  * A seach context lives for the duration of a readdir.
 666  *
 667  * All these functions must be called while yaffs is locked.
 668  */
 669
 670 struct yaffs_search_context {
 671         struct yaffs_dev *dev;
 672         struct yaffs_obj *dir_obj;
 673         struct yaffs_obj *next_return;
 674         struct list_head others;
 675 };
 676
 677 /*
 678  * yaffs_new_search() creates a new search context, initialises it and
 679  * adds it to the device's search context list.
 680  *
 681  * Called at start of readdir.
 682  */
 683 static struct yaffs_search_context *yaffs_new_search(struct yaffs_obj *dir)
 684 {
 685         struct yaffs_dev *dev = dir->my_dev;
 686         struct yaffs_search_context *sc =
 687             kmalloc(sizeof(struct yaffs_search_context), GFP_NOFS);
 688
 689         if (!sc)
 690                 return NULL;
 691
 692         sc->dir_obj = dir;
 693         sc->dev = dev;
 694         if (list_empty(&sc->dir_obj->variant.dir_variant.children))
 695                 sc->next_return = NULL;
 696         else
 697                 sc->next_return =
 698                     list_entry(dir->variant.dir_variant.children.next,
 699                                struct yaffs_obj, siblings);
 700         INIT_LIST_HEAD(&sc->others);
 701         list_add(&sc->others, &(yaffs_dev_to_lc(dev)->search_contexts));
 702
 703         return sc;
 704 }
 705
 706 /*
 707  * yaffs_search_end() disposes of a search context and cleans up.
 708  */
 709 static void yaffs_search_end(struct yaffs_search_context *sc)
 710 {
 711         if (sc) {
 712                 list_del(&sc->others);
 713                 kfree(sc);
 714         }
 715 }
 716
 717 /*
 718  * yaffs_search_advance() moves a search context to the next object.
 719  * Called when the search iterates or when an object removal causes
 720  * the search context to be moved to the next object.
 721  */
 722 static void yaffs_search_advance(struct yaffs_search_context *sc)
 723 {
 724         if (!sc)
 725                 return;
 726
 727         if (sc->next_return == NULL ||
 728             list_empty(&sc->dir_obj->variant.dir_variant.children))
 729                 sc->next_return = NULL;
 730         else {
 731                 struct list_head *next = sc->next_return->siblings.next;
 732
 733                 if (next == &sc->dir_obj->variant.dir_variant.children)
 734                         sc->next_return = NULL; /* end of list */
 735                 else
 736                         sc->next_return =
 737                             list_entry(next, struct yaffs_obj, siblings);
 738         }
 739 }
 740
 741 /*
 742  * yaffs_remove_obj_callback() is called when an object is unlinked.
 743  * We check open search contexts and advance any which are currently
 744  * on the object being iterated.
 745  */
 746 static void yaffs_remove_obj_callback(struct yaffs_obj *obj)
 747 {
 748
 749         struct list_head *i;
 750         struct yaffs_search_context *sc;
 751         struct list_head *search_contexts =
 752             &(yaffs_dev_to_lc(obj->my_dev)->search_contexts);
 753
 754         /* Iterate through the directory search contexts.
 755          * If any are currently on the object being removed, then advance
 756          * the search context to the next object to prevent a hanging pointer.
 757          */
 758         list_for_each(i, search_contexts) {
 759                 sc = list_entry(i, struct yaffs_search_context, others);
 760                 if (sc->next_return == obj)
 761                         yaffs_search_advance(sc);
 762         }
 763
 764 }
 765
 766 static int yaffs_readdir(struct file *f, void *dirent, filldir_t filldir)
 767 {
 768         struct yaffs_obj *obj;
 769         struct yaffs_dev *dev;
 770         struct yaffs_search_context *sc;
 771         struct inode *inode = f->f_dentry->d_inode;
 772         unsigned long offset, curoffs;
 773         struct yaffs_obj *l;
 774         int ret_val = 0;
 775         char name[YAFFS_MAX_NAME_LENGTH + 1];
 776
 777         obj = yaffs_dentry_to_obj(f->f_dentry);
 778         dev = obj->my_dev;
 779
 780         yaffs_gross_lock(dev);
 781
 782         yaffs_dev_to_lc(dev)->readdir_process = current;
 783
 784         offset = f->f_pos;
 785
 786         sc = yaffs_new_search(obj);
 787         if (!sc) {
 788                 ret_val = -ENOMEM;
 789                 goto out;
 790         }
 791
 792         yaffs_trace(YAFFS_TRACE_OS,
 793                 "yaffs_readdir: starting at %d", (int)offset);
 794
 795         if (offset == 0) {
 796                 yaffs_trace(YAFFS_TRACE_OS,
 797                         "yaffs_readdir: entry . ino %d",
 798                         (int)inode->i_ino);
 799                 yaffs_gross_unlock(dev);
 800                 if (filldir(dirent, ".", 1, offset, inode->i_ino, DT_DIR) < 0) {
 801                         yaffs_gross_lock(dev);
 802                         goto out;
 803                 }
 804                 yaffs_gross_lock(dev);
 805                 offset++;
 806                 f->f_pos++;
 807         }
 808         if (offset == 1) {
 809                 yaffs_trace(YAFFS_TRACE_OS,
 810                         "yaffs_readdir: entry .. ino %d",
 811                         (int)f->f_dentry->d_parent->d_inode->i_ino);
 812                 yaffs_gross_unlock(dev);
 813                 if (filldir(dirent, "..", 2, offset,
 814                             f->f_dentry->d_parent->d_inode->i_ino,
 815                             DT_DIR) < 0) {
 816                         yaffs_gross_lock(dev);
 817                         goto out;
 818                 }
 819                 yaffs_gross_lock(dev);
 820                 offset++;
 821                 f->f_pos++;
 822         }
 823
 824         curoffs = 1;
 825
 826         /* If the directory has changed since the open or last call to
 827            readdir, rewind to after the 2 canned entries. */
 828         if (f->f_version != inode->i_version) {
 829                 offset = 2;
 830                 f->f_pos = offset;
 831                 f->f_version = inode->i_version;
 832         }
 833
 834         while (sc->next_return) {
 835                 curoffs++;
 836                 l = sc->next_return;
 837                 if (curoffs >= offset) {
 838                         int this_inode = yaffs_get_obj_inode(l);
 839                         int this_type = yaffs_get_obj_type(l);
 840
 841                         yaffs_get_obj_name(l, name, YAFFS_MAX_NAME_LENGTH + 1);
 842                         yaffs_trace(YAFFS_TRACE_OS,
 843                                 "yaffs_readdir: %s inode %d",
 844                                 name, yaffs_get_obj_inode(l));
 845
 846                         yaffs_gross_unlock(dev);
 847
 848                         if (filldir(dirent,
 849                                     name,
 850                                     strlen(name),
 851                                     offset, this_inode, this_type) < 0) {
 852                                 yaffs_gross_lock(dev);
 853                                 goto out;
 854                         }
 855
 856                         yaffs_gross_lock(dev);
 857
 858                         offset++;
 859                         f->f_pos++;
 860                 }
 861                 yaffs_search_advance(sc);
 862         }
 863
 864 out:
 865         yaffs_search_end(sc);
 866         yaffs_dev_to_lc(dev)->readdir_process = NULL;
 867         yaffs_gross_unlock(dev);
 868
 869         return ret_val;
 870 }
 871
 872 static const struct file_operations yaffs_dir_operations = {
 873         .read = generic_read_dir,
 874         .readdir = yaffs_readdir,
 875         .fsync = yaffs_sync_object,
 876         .llseek = generic_file_llseek,
 877 };
 878
 879
 880
 881 static int yaffs_file_flush(struct file *file, fl_owner_t id)
 882 {
 883         struct yaffs_obj *obj = yaffs_dentry_to_obj(file->f_dentry);
 884         struct yaffs_dev *dev = obj->my_dev;
 885
 886         yaffs_trace(YAFFS_TRACE_OS,
 887                 "yaffs_file_flush object %d (%s)",
 888                 obj->obj_id, obj->dirty ? "dirty" : "clean");
 889
 890         yaffs_gross_lock(dev);
 891
 892         yaffs_flush_file(obj, 1, 0);
 893
 894         yaffs_gross_unlock(dev);
 895
 896         return 0;
 897 }
 898
 899 static const struct file_operations yaffs_file_operations = {
 900         .read = do_sync_read,
 901         .write = do_sync_write,
 902         .aio_read = generic_file_aio_read,
 903         .aio_write = generic_file_aio_write,
 904         .mmap = generic_file_mmap,
 905         .flush = yaffs_file_flush,
 906         .fsync = yaffs_sync_object,
 907         .splice_read = generic_file_splice_read,
 908         .splice_write = generic_file_splice_write,
 909         .llseek = generic_file_llseek,
 910 };
 911
 912
 913 /* ExportFS support */
 914 static struct inode *yaffs2_nfs_get_inode(struct super_block *sb, uint64_t ino,
 915                                           uint32_t generation)
 916 {
 917         return yaffs_iget(sb, ino);
 918 }
 919
 920 static struct dentry *yaffs2_fh_to_dentry(struct super_block *sb,
 921                                           struct fid *fid, int fh_len,
 922                                           int fh_type)
 923 {
 924         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 925                                     yaffs2_nfs_get_inode);
 926 }
 927
 928 static struct dentry *yaffs2_fh_to_parent(struct super_block *sb,
 929                                           struct fid *fid, int fh_len,
 930                                           int fh_type)
 931 {
 932         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 933                                     yaffs2_nfs_get_inode);
 934 }
 935
 936 struct dentry *yaffs2_get_parent(struct dentry *dentry)
 937 {
 938
 939         struct super_block *sb = dentry->d_inode->i_sb;
 940         struct dentry *parent = ERR_PTR(-ENOENT);
 941         struct inode *inode;
 942         unsigned long parent_ino;
 943         struct yaffs_obj *d_obj;
 944         struct yaffs_obj *parent_obj;
 945
 946         d_obj = yaffs_inode_to_obj(dentry->d_inode);
 947
 948         if (d_obj) {
 949                 parent_obj = d_obj->parent;
 950                 if (parent_obj) {
 951                         parent_ino = yaffs_get_obj_inode(parent_obj);
 952                         inode = yaffs_iget(sb, parent_ino);
 953
 954                         if (IS_ERR(inode)) {
 955                                 parent = ERR_CAST(inode);
 956                         } else {
 957                                 parent = d_obtain_alias(inode);
 958                                 if (!IS_ERR(parent)) {
 959                                         parent = ERR_PTR(-ENOMEM);
 960                                         iput(inode);
 961                                 }
 962                         }
 963                 }
 964         }
 965         return parent;
 966 }
 967
 968 /* Just declare a zero structure as a NULL value implies
 969  * using the default functions of exportfs.
 970  */
 971
 972 static struct export_operations yaffs_export_ops = {
 973         .fh_to_dentry = yaffs2_fh_to_dentry,
 974         .fh_to_parent = yaffs2_fh_to_parent,
 975         .get_parent = yaffs2_get_parent,
 976 };
 977
 978
 979 /*-----------------------------------------------------------------*/
 980
 981 static int yaffs_readlink(struct dentry *dentry, char __user * buffer,
 982                           int buflen)
 983 {
 984         unsigned char *alias;
 985         int ret;
 986         struct yaffs_dev *dev = yaffs_dentry_to_obj(dentry)->my_dev;
 987
 988         yaffs_gross_lock(dev);
 989
 990         alias = yaffs_get_symlink_alias(yaffs_dentry_to_obj(dentry));
 991
 992         yaffs_gross_unlock(dev);
 993
 994         if (!alias)
 995                 return -ENOMEM;
 996
 997         ret = vfs_readlink(dentry, buffer, buflen, alias);
 998         kfree(alias);
 999         return ret;
1000 }
1001
1002 static void *yaffs_follow_link(struct dentry *dentry, struct nameidata *nd)
1003 {
1004         unsigned char *alias;
1005         void *ret;
1006         struct yaffs_dev *dev = yaffs_dentry_to_obj(dentry)->my_dev;
1007
1008         yaffs_gross_lock(dev);
1009
1010         alias = yaffs_get_symlink_alias(yaffs_dentry_to_obj(dentry));
1011         yaffs_gross_unlock(dev);
1012
1013         if (!alias) {
1014                 ret = ERR_PTR(-ENOMEM);
1015                 goto out;
1016         }
1017
1018         nd_set_link(nd, alias);
1019         ret = (void *)alias;
1020 out:
1021         return ret;
1022 }
1023
1024 void yaffs_put_link(struct dentry *dentry, struct nameidata *nd, void *alias)
1025 {
1026         kfree(alias);
1027 }
1028
1029
1030 static void yaffs_unstitch_obj(struct inode *inode, struct yaffs_obj *obj)
1031 {
1032         /* Clear the association between the inode and
1033          * the struct yaffs_obj.
1034          */
1035         obj->my_inode = NULL;
1036         yaffs_inode_to_obj_lv(inode) = NULL;
1037
1038         /* If the object freeing was deferred, then the real
1039          * free happens now.
1040          * This should fix the inode inconsistency problem.
1041          */
1042         yaffs_handle_defered_free(obj);
1043 }
1044
1045 /* yaffs_evict_inode combines into one operation what was previously done in
1046  * yaffs_clear_inode() and yaffs_delete_inode()
1047  *
1048  */
1049 static void yaffs_evict_inode(struct inode *inode)
1050 {
1051         struct yaffs_obj *obj;
1052         struct yaffs_dev *dev;
1053         int deleteme = 0;
1054
1055         obj = yaffs_inode_to_obj(inode);
1056
1057         yaffs_trace(YAFFS_TRACE_OS,
1058                 "yaffs_evict_inode: ino %d, count %d %s",
1059                 (int)inode->i_ino,
1060                 atomic_read(&inode->i_count),
1061                 obj ? "object exists" : "null object");
1062
1063         if (!inode->i_nlink && !is_bad_inode(inode))
1064                 deleteme = 1;
1065         truncate_inode_pages(&inode->i_data, 0);
1066         end_writeback(inode);
1067
1068         if (deleteme && obj) {
1069                 dev = obj->my_dev;
1070                 yaffs_gross_lock(dev);
1071                 yaffs_del_obj(obj);
1072                 yaffs_gross_unlock(dev);
1073         }
1074         if (obj) {
1075                 dev = obj->my_dev;
1076                 yaffs_gross_lock(dev);
1077                 yaffs_unstitch_obj(inode, obj);
1078                 yaffs_gross_unlock(dev);
1079         }
1080
1081 }
1082
1083 static void yaffs_touch_super(struct yaffs_dev *dev)
1084 {
1085         struct super_block *sb = yaffs_dev_to_lc(dev)->super;
1086
1087         yaffs_trace(YAFFS_TRACE_OS, "yaffs_touch_super() sb = %p", sb);
1088         if (sb)
1089                 sb->s_dirt = 1;
1090 }
1091
1092 static int yaffs_readpage_nolock(struct file *f, struct page *pg)
1093 {
1094         /* Lifted from jffs2 */
1095
1096         struct yaffs_obj *obj;
1097         unsigned char *pg_buf;
1098         int ret;
1099         struct yaffs_dev *dev;
1100         loff_t pos = ((loff_t) pg->index) << PAGE_CACHE_SHIFT;
1101
1102         yaffs_trace(YAFFS_TRACE_OS,
1103                 "yaffs_readpage_nolock at %lld, size %08x",
1104                 (long long)pos,
1105                 (unsigned)PAGE_CACHE_SIZE);
1106
1107
1108         obj = yaffs_dentry_to_obj(f->f_dentry);
1109
1110         dev = obj->my_dev;
1111
1112         BUG_ON(!PageLocked(pg));
1113
1114         pg_buf = kmap(pg);
1115         /* FIXME: Can kmap fail? */
1116
1117         yaffs_gross_lock(dev);
1118
1119         ret = yaffs_file_rd(obj, pg_buf, pos, PAGE_CACHE_SIZE);
1120
1121         yaffs_gross_unlock(dev);
1122
1123         if (ret >= 0)
1124                 ret = 0;
1125
1126         if (ret) {
1127                 ClearPageUptodate(pg);
1128                 SetPageError(pg);
1129         } else {
1130                 SetPageUptodate(pg);
1131                 ClearPageError(pg);
1132         }
1133
1134         flush_dcache_page(pg);
1135         kunmap(pg);
1136
1137         yaffs_trace(YAFFS_TRACE_OS, "yaffs_readpage_nolock done");
1138         return ret;
1139 }
1140
1141 static int yaffs_readpage_unlock(struct file *f, struct page *pg)
1142 {
1143         int ret = yaffs_readpage_nolock(f, pg);
1144
1145         unlock_page(pg);
1146         return ret;
1147 }
1148
1149 static int yaffs_readpage(struct file *f, struct page *pg)
1150 {
1151         int ret;
1152
1153         yaffs_trace(YAFFS_TRACE_OS, "yaffs_readpage");
1154         ret = yaffs_readpage_unlock(f, pg);
1155         yaffs_trace(YAFFS_TRACE_OS, "yaffs_readpage done");
1156         return ret;
1157 }
1158
1159 /* writepage inspired by/stolen from smbfs */
1160
1161 static int yaffs_writepage(struct page *page, struct writeback_control *wbc)
1162 {
1163         struct yaffs_dev *dev;
1164         struct address_space *mapping = page->mapping;
1165         struct inode *inode;
1166         unsigned long end_index;
1167         char *buffer;
1168         struct yaffs_obj *obj;
1169         int n_written = 0;
1170         unsigned n_bytes;
1171         loff_t i_size;
1172
1173         if (!mapping)
1174                 BUG();
1175         inode = mapping->host;
1176         if (!inode)
1177                 BUG();
1178         i_size = i_size_read(inode);
1179
1180         end_index = i_size >> PAGE_CACHE_SHIFT;
1181
1182         if (page->index < end_index)
1183                 n_bytes = PAGE_CACHE_SIZE;
1184         else {
1185                 n_bytes = i_size & (PAGE_CACHE_SIZE - 1);
1186
1187                 if (page->index > end_index || !n_bytes) {
1188                         yaffs_trace(YAFFS_TRACE_OS,
1189                                 "yaffs_writepage at %08x, inode size = %08x!!!",
1190                                 (unsigned)(page->index << PAGE_CACHE_SHIFT),
1191                                 (unsigned)inode->i_size);
1192                         yaffs_trace(YAFFS_TRACE_OS,
1193                           "                -> don't care!!");
1194
1195                         zero_user_segment(page, 0, PAGE_CACHE_SIZE);
1196                         set_page_writeback(page);
1197                         unlock_page(page);
1198                         end_page_writeback(page);
1199                         return 0;
1200                 }
1201         }
1202
1203         if (n_bytes != PAGE_CACHE_SIZE)
1204                 zero_user_segment(page, n_bytes, PAGE_CACHE_SIZE);
1205
1206         get_page(page);
1207
1208         buffer = kmap(page);
1209
1210         obj = yaffs_inode_to_obj(inode);
1211         dev = obj->my_dev;
1212         yaffs_gross_lock(dev);
1213
1214         yaffs_trace(YAFFS_TRACE_OS,
1215                 "yaffs_writepage at %08x, size %08x",
1216                 (unsigned)(page->index << PAGE_CACHE_SHIFT), n_bytes);
1217         yaffs_trace(YAFFS_TRACE_OS,
1218                 "writepag0: obj = %05x, ino = %05x",
1219                 (int)obj->variant.file_variant.file_size, (int)inode->i_size);
1220
1221         n_written = yaffs_wr_file(obj, buffer,
1222                                   ((loff_t)page->index) << PAGE_CACHE_SHIFT, n_bytes, 0);
1223
1224         yaffs_touch_super(dev);
1225
1226         yaffs_trace(YAFFS_TRACE_OS,
1227                 "writepag1: obj = %05x, ino = %05x",
1228                 (int)obj->variant.file_variant.file_size, (int)inode->i_size);
1229
1230         yaffs_gross_unlock(dev);
1231
1232         kunmap(page);
1233         set_page_writeback(page);
1234         unlock_page(page);
1235         end_page_writeback(page);
1236         put_page(page);
1237
1238         return (n_written == n_bytes) ? 0 : -ENOSPC;
1239 }
1240
1241 /* Space holding and freeing is done to ensure we have space available for
1242  * write_begin/end.
1243  * For now we just assume few parallel writes and check against a small
1244  * number.
1245  * Todo: need to do this with a counter to handle parallel reads better
1246  */
1247
1248 static ssize_t yaffs_hold_space(struct file *f)
1249 {
1250         struct yaffs_obj *obj;
1251         struct yaffs_dev *dev;
1252         int n_free_chunks;
1253
1254         obj = yaffs_dentry_to_obj(f->f_dentry);
1255
1256         dev = obj->my_dev;
1257
1258         yaffs_gross_lock(dev);
1259
1260         n_free_chunks = yaffs_get_n_free_chunks(dev);
1261
1262         yaffs_gross_unlock(dev);
1263
1264         return (n_free_chunks > 20) ? 1 : 0;
1265 }
1266
1267 static void yaffs_release_space(struct file *f)
1268 {
1269         struct yaffs_obj *obj;
1270         struct yaffs_dev *dev;
1271
1272         obj = yaffs_dentry_to_obj(f->f_dentry);
1273
1274         dev = obj->my_dev;
1275
1276         yaffs_gross_lock(dev);
1277
1278         yaffs_gross_unlock(dev);
1279 }
1280
1281 static int yaffs_write_begin(struct file *filp, struct address_space *mapping,
1282                              loff_t pos, unsigned len, unsigned flags,
1283                              struct page **pagep, void **fsdata)
1284 {
1285         struct page *pg = NULL;
1286         pgoff_t index = pos >> PAGE_CACHE_SHIFT;
1287         int ret = 0;
1288         int space_held = 0;
1289
1290         /* Get a page */
1291         pg = grab_cache_page_write_begin(mapping, index, flags);
1292
1293         *pagep = pg;
1294         if (!pg) {
1295                 ret = -ENOMEM;
1296                 goto out;
1297         }
1298         yaffs_trace(YAFFS_TRACE_OS,
1299                 "start yaffs_write_begin index %d(%x) uptodate %d",
1300                 (int)index, (int)index, PageUptodate(pg) ? 1 : 0);
1301
1302         /* Get fs space */
1303         space_held = yaffs_hold_space(filp);
1304
1305         if (!space_held) {
1306                 ret = -ENOSPC;
1307                 goto out;
1308         }
1309
1310         /* Update page if required */
1311
1312         if (!PageUptodate(pg))
1313                 ret = yaffs_readpage_nolock(filp, pg);
1314
1315         if (ret)
1316                 goto out;
1317
1318         /* Happy path return */
1319         yaffs_trace(YAFFS_TRACE_OS, "end yaffs_write_begin - ok");
1320
1321         return 0;
1322
1323 out:
1324         yaffs_trace(YAFFS_TRACE_OS,
1325                 "end yaffs_write_begin fail returning %d", ret);
1326         if (space_held)
1327                 yaffs_release_space(filp);
1328         if (pg) {
1329                 unlock_page(pg);
1330                 page_cache_release(pg);
1331         }
1332         return ret;
1333 }
1334
1335 static ssize_t yaffs_file_write(struct file *f, const char *buf, size_t n,
1336                                 loff_t *pos)
1337 {
1338         struct yaffs_obj *obj;
1339         int n_written, ipos;
1340         struct inode *inode;
1341         struct yaffs_dev *dev;
1342
1343         obj = yaffs_dentry_to_obj(f->f_dentry);
1344
1345         if (!obj) {
1346                 /* This should not happen */
1347                 yaffs_trace(YAFFS_TRACE_OS,
1348                         "yaffs_file_write: hey obj is null!");
1349                 return -EINVAL;
1350         }
1351
1352         dev = obj->my_dev;
1353
1354         yaffs_gross_lock(dev);
1355
1356         inode = f->f_dentry->d_inode;
1357
1358         if (!S_ISBLK(inode->i_mode) && f->f_flags & O_APPEND)
1359                 ipos = inode->i_size;
1360         else
1361                 ipos = *pos;
1362
1363         yaffs_trace(YAFFS_TRACE_OS,
1364                 "yaffs_file_write about to write writing %u(%x) bytes to object %d at %d(%x)",
1365                 (unsigned)n, (unsigned)n, obj->obj_id, ipos, ipos);
1366
1367         n_written = yaffs_wr_file(obj, buf, ipos, n, 0);
1368
1369         yaffs_touch_super(dev);
1370
1371         yaffs_trace(YAFFS_TRACE_OS,
1372                 "yaffs_file_write: %d(%x) bytes written",
1373                 (unsigned)n, (unsigned)n);
1374
1375         if (n_written > 0) {
1376                 ipos += n_written;
1377                 *pos = ipos;
1378                 if (ipos > inode->i_size) {
1379                         inode->i_size = ipos;
1380                         inode->i_blocks = (ipos + 511) >> 9;
1381
1382                         yaffs_trace(YAFFS_TRACE_OS,
1383                                 "yaffs_file_write size updated to %d bytes, %d blocks",
1384                                 ipos, (int)(inode->i_blocks));
1385                 }
1386         }
1387         yaffs_gross_unlock(dev);
1388         return (n_written == 0) && (n > 0) ? -ENOSPC : n_written;
1389 }
1390
1391 static int yaffs_write_end(struct file *filp, struct address_space *mapping,
1392                            loff_t pos, unsigned len, unsigned copied,
1393                            struct page *pg, void *fsdadata)
1394 {
1395         int ret = 0;
1396         void *addr, *kva;
1397         uint32_t offset_into_page = pos & (PAGE_CACHE_SIZE - 1);
1398
1399         kva = kmap(pg);
1400         addr = kva + offset_into_page;
1401
1402         yaffs_trace(YAFFS_TRACE_OS,
1403                 "yaffs_write_end addr %p pos %x n_bytes %d",
1404                 addr, (unsigned)pos, copied);
1405
1406         ret = yaffs_file_write(filp, addr, copied, &pos);
1407
1408         if (ret != copied) {
1409                 yaffs_trace(YAFFS_TRACE_OS,
1410                         "yaffs_write_end not same size ret %d  copied %d",
1411                         ret, copied);
1412                 SetPageError(pg);
1413         }
1414
1415         kunmap(pg);
1416
1417         yaffs_release_space(filp);
1418         unlock_page(pg);
1419         page_cache_release(pg);
1420         return ret;
1421 }
1422
1423 static int yaffs_statfs(struct dentry *dentry, struct kstatfs *buf)
1424 {
1425         struct yaffs_dev *dev = yaffs_dentry_to_obj(dentry)->my_dev;
1426         struct super_block *sb = dentry->d_sb;
1427
1428         yaffs_trace(YAFFS_TRACE_OS, "yaffs_statfs");
1429
1430         yaffs_gross_lock(dev);
1431
1432         buf->f_type = YAFFS_MAGIC;
1433         buf->f_bsize = sb->s_blocksize;
1434         buf->f_namelen = 255;
1435
1436         if (dev->data_bytes_per_chunk & (dev->data_bytes_per_chunk - 1)) {
1437                 /* Do this if chunk size is not a power of 2 */
1438
1439                 uint64_t bytes_in_dev;
1440                 uint64_t bytes_free;
1441
1442                 bytes_in_dev =
1443                     ((uint64_t)
1444                      ((dev->param.end_block - dev->param.start_block + 1))) *
1445                      ((uint64_t) (dev->param.chunks_per_block *
1446                                            dev->data_bytes_per_chunk));
1447
1448                 do_div(bytes_in_dev, sb->s_blocksize);
1449                         /* bytes_in_dev becomes the number of blocks */
1450                 buf->f_blocks = bytes_in_dev;
1451
1452                 bytes_free = ((uint64_t) (yaffs_get_n_free_chunks(dev))) *
1453                     ((uint64_t) (dev->data_bytes_per_chunk));
1454
1455                 do_div(bytes_free, sb->s_blocksize);
1456
1457                 buf->f_bfree = bytes_free;
1458
1459         } else if (sb->s_blocksize > dev->data_bytes_per_chunk) {
1460
1461                 buf->f_blocks =
1462                     (dev->param.end_block - dev->param.start_block + 1) *
1463                     dev->param.chunks_per_block /
1464                     (sb->s_blocksize / dev->data_bytes_per_chunk);
1465                 buf->f_bfree =
1466                     yaffs_get_n_free_chunks(dev) /
1467                     (sb->s_blocksize / dev->data_bytes_per_chunk);
1468         } else {
1469                 buf->f_blocks =
1470                     (dev->param.end_block - dev->param.start_block + 1) *
1471                     dev->param.chunks_per_block *
1472                     (dev->data_bytes_per_chunk / sb->s_blocksize);
1473
1474                 buf->f_bfree =
1475                     yaffs_get_n_free_chunks(dev) *
1476                     (dev->data_bytes_per_chunk / sb->s_blocksize);
1477         }
1478
1479         buf->f_files = 0;
1480         buf->f_ffree = 0;
1481         buf->f_bavail = buf->f_bfree;
1482
1483         yaffs_gross_unlock(dev);
1484         return 0;
1485 }
1486
1487 static void yaffs_flush_inodes(struct super_block *sb)
1488 {
1489         struct inode *iptr;
1490         struct yaffs_obj *obj;
1491
1492         list_for_each_entry(iptr, &sb->s_inodes, i_sb_list) {
1493                 obj = yaffs_inode_to_obj(iptr);
1494                 if (obj) {
1495                         yaffs_trace(YAFFS_TRACE_OS,
1496                                 "flushing obj %d", obj->obj_id);
1497                         yaffs_flush_file(obj, 1, 0);
1498                 }
1499         }
1500 }
1501
1502 static void yaffs_flush_super(struct super_block *sb, int do_checkpoint)
1503 {
1504         struct yaffs_dev *dev = yaffs_super_to_dev(sb);
1505
1506         if (!dev)
1507                 return;
1508
1509         yaffs_flush_inodes(sb);
1510         yaffs_update_dirty_dirs(dev);
1511         yaffs_flush_whole_cache(dev);
1512         if (do_checkpoint)
1513                 yaffs_checkpoint_save(dev);
1514 }
1515
1516 static unsigned yaffs_bg_gc_urgency(struct yaffs_dev *dev)
1517 {
1518         unsigned erased_chunks =
1519             dev->n_erased_blocks * dev->param.chunks_per_block;
1520         struct yaffs_linux_context *context = yaffs_dev_to_lc(dev);
1521         unsigned scattered = 0; /* Free chunks not in an erased block */
1522
1523         if (erased_chunks < dev->n_free_chunks)
1524                 scattered = (dev->n_free_chunks - erased_chunks);
1525
1526         if (!context->bg_running)
1527                 return 0;
1528         else if (scattered < (dev->param.chunks_per_block * 2))
1529                 return 0;
1530         else if (erased_chunks > dev->n_free_chunks / 2)
1531                 return 0;
1532         else if (erased_chunks > dev->n_free_chunks / 4)
1533                 return 1;
1534         else
1535                 return 2;
1536 }
1537
1538 static int yaffs_do_sync_fs(struct super_block *sb, int request_checkpoint)
1539 {
1540
1541         struct yaffs_dev *dev = yaffs_super_to_dev(sb);
1542         unsigned int oneshot_checkpoint = (yaffs_auto_checkpoint & 4);
1543         unsigned gc_urgent = yaffs_bg_gc_urgency(dev);
1544         int do_checkpoint;
1545
1546         yaffs_trace(YAFFS_TRACE_OS | YAFFS_TRACE_SYNC | YAFFS_TRACE_BACKGROUND,
1547                 "yaffs_do_sync_fs: gc-urgency %d %s %s%s",
1548                 gc_urgent,
1549                 sb->s_dirt ? "dirty" : "clean",
1550                 request_checkpoint ? "checkpoint requested" : "no checkpoint",
1551                 oneshot_checkpoint ? " one-shot" : "");
1552
1553         yaffs_gross_lock(dev);
1554         do_checkpoint = ((request_checkpoint && !gc_urgent) ||
1555                          oneshot_checkpoint) && !dev->is_checkpointed;
1556
1557         if (sb->s_dirt || do_checkpoint) {
1558                 yaffs_flush_super(sb, !dev->is_checkpointed && do_checkpoint);
1559                 sb->s_dirt = 0;
1560                 if (oneshot_checkpoint)
1561                         yaffs_auto_checkpoint &= ~4;
1562         }
1563         yaffs_gross_unlock(dev);
1564
1565         return 0;
1566 }
1567
1568 /*
1569  * yaffs background thread functions .
1570  * yaffs_bg_thread_fn() the thread function
1571  * yaffs_bg_start() launches the background thread.
1572  * yaffs_bg_stop() cleans up the background thread.
1573  *
1574  * NB:
1575  * The thread should only run after the yaffs is initialised
1576  * The thread should be stopped before yaffs is unmounted.
1577  * The thread should not do any writing while the fs is in read only.
1578  */
1579
1580 void yaffs_background_waker(unsigned long data)
1581 {
1582         wake_up_process((struct task_struct *)data);
1583 }
1584
1585 static int yaffs_bg_thread_fn(void *data)
1586 {
1587         struct yaffs_dev *dev = (struct yaffs_dev *)data;
1588         struct yaffs_linux_context *context = yaffs_dev_to_lc(dev);
1589         unsigned long now = jiffies;
1590         unsigned long next_dir_update = now;
1591         unsigned long next_gc = now;
1592         unsigned long expires;
1593         unsigned int urgency;
1594         int gc_result;
1595         struct timer_list timer;
1596
1597         yaffs_trace(YAFFS_TRACE_BACKGROUND,
1598                 "yaffs_background starting for dev %p", (void *)dev);
1599
1600         set_freezable();
1601         while (context->bg_running) {
1602                 yaffs_trace(YAFFS_TRACE_BACKGROUND, "yaffs_background");
1603
1604                 if (kthread_should_stop())
1605                         break;
1606
1607                 if (try_to_freeze())
1608                         continue;
1609
1610                 yaffs_gross_lock(dev);
1611
1612                 now = jiffies;
1613
1614                 if (time_after(now, next_dir_update) && yaffs_bg_enable) {
1615                         yaffs_update_dirty_dirs(dev);
1616                         next_dir_update = now + HZ;
1617                 }
1618
1619                 if (time_after(now, next_gc) && yaffs_bg_enable) {
1620                         if (!dev->is_checkpointed) {
1621                                 urgency = yaffs_bg_gc_urgency(dev);
1622                                 gc_result = yaffs_bg_gc(dev, urgency);
1623                                 if (urgency > 1)
1624                                         next_gc = now + HZ / 20 + 1;
1625                                 else if (urgency > 0)
1626                                         next_gc = now + HZ / 10 + 1;
1627                                 else
1628                                         next_gc = now + HZ * 2;
1629                         } else  {
1630                                 /*
1631                                  * gc not running so set to next_dir_update
1632                                  * to cut down on wake ups
1633                                  */
1634                                 next_gc = next_dir_update;
1635                         }
1636                 }
1637                 yaffs_gross_unlock(dev);
1638                 expires = next_dir_update;
1639                 if (time_before(next_gc, expires))
1640                         expires = next_gc;
1641                 if (time_before(expires, now))
1642                         expires = now + HZ;
1643
1644                 init_timer_on_stack(&timer);
1645                 timer.expires = expires + 1;
1646                 timer.data = (unsigned long)current;
1647                 timer.function = yaffs_background_waker;
1648
1649                 set_current_state(TASK_INTERRUPTIBLE);
1650                 add_timer(&timer);
1651                 schedule();
1652                 del_timer_sync(&timer);
1653         }
1654
1655         return 0;
1656 }
1657
1658 static int yaffs_bg_start(struct yaffs_dev *dev)
1659 {
1660         int retval = 0;
1661         struct yaffs_linux_context *context = yaffs_dev_to_lc(dev);
1662
1663         if (dev->read_only)
1664                 return -1;
1665
1666         context->bg_running = 1;
1667
1668         context->bg_thread = kthread_run(yaffs_bg_thread_fn,
1669                                          (void *)dev, "yaffs-bg-%d",
1670                                          context->mount_id);
1671
1672         if (IS_ERR(context->bg_thread)) {
1673                 retval = PTR_ERR(context->bg_thread);
1674                 context->bg_thread = NULL;
1675                 context->bg_running = 0;
1676         }
1677         return retval;
1678 }
1679
1680 static void yaffs_bg_stop(struct yaffs_dev *dev)
1681 {
1682         struct yaffs_linux_context *ctxt = yaffs_dev_to_lc(dev);
1683
1684         ctxt->bg_running = 0;
1685
1686         if (ctxt->bg_thread) {
1687                 kthread_stop(ctxt->bg_thread);
1688                 ctxt->bg_thread = NULL;
1689         }
1690 }
1691
1692 static void yaffs_write_super(struct super_block *sb)
1693 {
1694         unsigned request_checkpoint = (yaffs_auto_checkpoint >= 2);
1695
1696         yaffs_trace(YAFFS_TRACE_OS | YAFFS_TRACE_SYNC | YAFFS_TRACE_BACKGROUND,
1697                 "yaffs_write_super%s",
1698                 request_checkpoint ? " checkpt" : "");
1699
1700         yaffs_do_sync_fs(sb, request_checkpoint);
1701
1702 }
1703
1704 static int yaffs_sync_fs(struct super_block *sb, int wait)
1705 {
1706         unsigned request_checkpoint = (yaffs_auto_checkpoint >= 1);
1707
1708         yaffs_trace(YAFFS_TRACE_OS | YAFFS_TRACE_SYNC,
1709                 "yaffs_sync_fs%s", request_checkpoint ? " checkpt" : "");
1710
1711         yaffs_do_sync_fs(sb, request_checkpoint);
1712
1713         return 0;
1714 }
1715
1716 static LIST_HEAD(yaffs_context_list);
1717 struct mutex yaffs_context_lock;
1718
1719 struct yaffs_options {
1720         int inband_tags;
1721         int skip_checkpoint_read;
1722         int skip_checkpoint_write;
1723         int no_cache;
1724         int tags_ecc_on;
1725         int tags_ecc_overridden;
1726         int lazy_loading_enabled;
1727         int lazy_loading_overridden;
1728         int empty_lost_and_found;
1729         int empty_lost_and_found_overridden;
1730 };
1731
1732 #define MAX_OPT_LEN 30
1733 static int yaffs_parse_options(struct yaffs_options *options,
1734                                 const char *options_str)
1735 {
1736         char cur_opt[MAX_OPT_LEN + 1];
1737         int p;
1738         int error = 0;
1739
1740         /* Parse through the options which is a comma seperated list */
1741
1742         while (options_str && *options_str && !error) {
1743                 memset(cur_opt, 0, MAX_OPT_LEN + 1);
1744                 p = 0;
1745
1746                 while (*options_str == ',')
1747                         options_str++;
1748
1749                 while (*options_str && *options_str != ',') {
1750                         if (p < MAX_OPT_LEN) {
1751                                 cur_opt[p] = *options_str;
1752                                 p++;
1753                         }
1754                         options_str++;
1755                 }
1756
1757                 if (!strcmp(cur_opt, "inband-tags")) {
1758                         options->inband_tags = 1;
1759                 } else if (!strcmp(cur_opt, "tags-ecc-off")) {
1760                         options->tags_ecc_on = 0;
1761                         options->tags_ecc_overridden = 1;
1762                 } else if (!strcmp(cur_opt, "tags-ecc-on")) {
1763                         options->tags_ecc_on = 1;
1764                         options->tags_ecc_overridden = 1;
1765                 } else if (!strcmp(cur_opt, "lazy-loading-off")) {
1766                         options->lazy_loading_enabled = 0;
1767                         options->lazy_loading_overridden = 1;
1768                 } else if (!strcmp(cur_opt, "lazy-loading-on")) {
1769                         options->lazy_loading_enabled = 1;
1770                         options->lazy_loading_overridden = 1;
1771                 } else if (!strcmp(cur_opt, "empty-lost-and-found-off")) {
1772                         options->empty_lost_and_found = 0;
1773                         options->empty_lost_and_found_overridden = 1;
1774                 } else if (!strcmp(cur_opt, "empty-lost-and-found-on")) {
1775                         options->empty_lost_and_found = 1;
1776                         options->empty_lost_and_found_overridden = 1;
1777                 } else if (!strcmp(cur_opt, "no-cache")) {
1778                         options->no_cache = 1;
1779                 } else if (!strcmp(cur_opt, "no-checkpoint-read")) {
1780                         options->skip_checkpoint_read = 1;
1781                 } else if (!strcmp(cur_opt, "no-checkpoint-write")) {
1782                         options->skip_checkpoint_write = 1;
1783                 } else if (!strcmp(cur_opt, "no-checkpoint")) {
1784                         options->skip_checkpoint_read = 1;
1785                         options->skip_checkpoint_write = 1;
1786                 } else {
1787                         printk(KERN_INFO "yaffs: Bad mount option \"%s\"\n",
1788                                cur_opt);
1789                         error = 1;
1790                 }
1791         }
1792         return error;
1793 }
1794
1795 static const struct address_space_operations yaffs_file_address_operations = {
1796         .readpage = yaffs_readpage,
1797         .writepage = yaffs_writepage,
1798         .write_begin = yaffs_write_begin,
1799         .write_end = yaffs_write_end,
1800 };
1801
1802
1803
1804 static const struct inode_operations yaffs_file_inode_operations = {
1805         .setattr = yaffs_setattr,
1806         .setxattr = yaffs_setxattr,
1807         .getxattr = yaffs_getxattr,
1808         .listxattr = yaffs_listxattr,
1809         .removexattr = yaffs_removexattr,
1810 };
1811
1812 static const struct inode_operations yaffs_symlink_inode_operations = {
1813         .readlink = yaffs_readlink,
1814         .follow_link = yaffs_follow_link,
1815         .put_link = yaffs_put_link,
1816         .setattr = yaffs_setattr,
1817         .setxattr = yaffs_setxattr,
1818         .getxattr = yaffs_getxattr,
1819         .listxattr = yaffs_listxattr,
1820         .removexattr = yaffs_removexattr,
1821 };
1822
1823 static void yaffs_fill_inode_from_obj(struct inode *inode,
1824                                       struct yaffs_obj *obj)
1825 {
1826         u32 mode;
1827
1828         if (!inode || !obj)  {
1829                 yaffs_trace(YAFFS_TRACE_OS,
1830                         "yaffs_fill_inode invalid parameters");
1831                 return;
1832         }
1833
1834         /* Check mode against the variant type
1835          * and attempt to repair if broken. */
1836         mode = obj->yst_mode;
1837
1838         switch (obj->variant_type) {
1839         case YAFFS_OBJECT_TYPE_FILE:
1840                 if (!S_ISREG(mode)) {
1841                         obj->yst_mode &= ~S_IFMT;
1842                         obj->yst_mode |= S_IFREG;
1843                 }
1844                 break;
1845         case YAFFS_OBJECT_TYPE_SYMLINK:
1846                 if (!S_ISLNK(mode)) {
1847                         obj->yst_mode &= ~S_IFMT;
1848                         obj->yst_mode |= S_IFLNK;
1849                 }
1850                 break;
1851         case YAFFS_OBJECT_TYPE_DIRECTORY:
1852                 if (!S_ISDIR(mode)) {
1853                         obj->yst_mode &= ~S_IFMT;
1854                         obj->yst_mode |= S_IFDIR;
1855                 }
1856                 break;
1857         case YAFFS_OBJECT_TYPE_UNKNOWN:
1858         case YAFFS_OBJECT_TYPE_HARDLINK:
1859         case YAFFS_OBJECT_TYPE_SPECIAL:
1860         default:
1861                 /* TODO? */
1862                 break;
1863         }
1864
1865         inode->i_flags |= S_NOATIME;
1866         inode->i_ino = obj->obj_id;
1867         inode->i_mode = obj->yst_mode;
1868         inode->i_uid = obj->yst_uid;
1869         inode->i_gid = obj->yst_gid;
1870
1871         inode->i_rdev = old_decode_dev(obj->yst_rdev);
1872
1873         inode->i_atime.tv_sec = (time_t) (obj->yst_atime);
1874         inode->i_atime.tv_nsec = 0;
1875         inode->i_mtime.tv_sec = (time_t) obj->yst_mtime;
1876         inode->i_mtime.tv_nsec = 0;
1877         inode->i_ctime.tv_sec = (time_t) obj->yst_ctime;
1878         inode->i_ctime.tv_nsec = 0;
1879         inode->i_size = yaffs_get_obj_length(obj);
1880         inode->i_blocks = (inode->i_size + 511) >> 9;
1881         set_nlink(inode, yaffs_get_obj_link_count(obj));
1882         yaffs_trace(YAFFS_TRACE_OS,
1883                 "yaffs_fill_inode mode %x uid %d gid %d size %d count %d",
1884                 inode->i_mode, inode->i_uid, inode->i_gid,
1885                 (int)inode->i_size, atomic_read(&inode->i_count));
1886
1887         switch (obj->yst_mode & S_IFMT) {
1888         default:        /* fifo, device or socket */
1889                 init_special_inode(inode, obj->yst_mode,
1890                                    old_decode_dev(obj->yst_rdev));
1891                 break;
1892         case S_IFREG:   /* file */
1893                 inode->i_op = &yaffs_file_inode_operations;
1894                 inode->i_fop = &yaffs_file_operations;
1895                 inode->i_mapping->a_ops = &yaffs_file_address_operations;
1896                 break;
1897         case S_IFDIR:   /* directory */
1898                 inode->i_op = &yaffs_dir_inode_operations;
1899                 inode->i_fop = &yaffs_dir_operations;
1900                 break;
1901         case S_IFLNK:   /* symlink */
1902                 inode->i_op = &yaffs_symlink_inode_operations;
1903                 break;
1904         }
1905
1906         yaffs_inode_to_obj_lv(inode) = obj;
1907         obj->my_inode = inode;
1908 }
1909
1910 static void yaffs_put_super(struct super_block *sb)
1911 {
1912         struct yaffs_dev *dev = yaffs_super_to_dev(sb);
1913
1914         yaffs_trace(YAFFS_TRACE_OS, "yaffs_put_super");
1915
1916         yaffs_trace(YAFFS_TRACE_OS | YAFFS_TRACE_BACKGROUND,
1917                 "Shutting down yaffs background thread");
1918         yaffs_bg_stop(dev);
1919         yaffs_trace(YAFFS_TRACE_OS | YAFFS_TRACE_BACKGROUND,
1920                 "yaffs background thread shut down");
1921
1922         yaffs_gross_lock(dev);
1923
1924         yaffs_flush_super(sb, 1);
1925
1926         if (yaffs_dev_to_lc(dev)->put_super_fn)
1927                 yaffs_dev_to_lc(dev)->put_super_fn(sb);
1928
1929         yaffs_deinitialise(dev);
1930
1931         yaffs_gross_unlock(dev);
1932         mutex_lock(&yaffs_context_lock);
1933         list_del_init(&(yaffs_dev_to_lc(dev)->context_list));
1934         mutex_unlock(&yaffs_context_lock);
1935
1936         if (yaffs_dev_to_lc(dev)->spare_buffer) {
1937                 kfree(yaffs_dev_to_lc(dev)->spare_buffer);
1938                 yaffs_dev_to_lc(dev)->spare_buffer = NULL;
1939         }
1940
1941         kfree(dev);
1942 }
1943
1944 static void yaffs_mtd_put_super(struct super_block *sb)
1945 {
1946         struct mtd_info *mtd = yaffs_dev_to_mtd(yaffs_super_to_dev(sb));
1947
1948         if (mtd->sync)
1949                 mtd->sync(mtd);
1950
1951         put_mtd_device(mtd);
1952 }
1953
1954 static const struct super_operations yaffs_super_ops = {
1955         .statfs = yaffs_statfs,
1956         .put_super = yaffs_put_super,
1957         .evict_inode = yaffs_evict_inode,
1958         .sync_fs = yaffs_sync_fs,
1959         .write_super = yaffs_write_super,
1960 };
1961
1962 static struct super_block *yaffs_internal_read_super(int yaffs_version,
1963                                                      struct super_block *sb,
1964                                                      void *data, int silent)
1965 {
1966         int n_blocks;
1967         struct inode *inode = NULL;
1968         struct dentry *root;
1969         struct yaffs_dev *dev = 0;
1970         char devname_buf[BDEVNAME_SIZE + 1];
1971         struct mtd_info *mtd;
1972         int err;
1973         char *data_str = (char *)data;
1974         struct yaffs_linux_context *context = NULL;
1975         struct yaffs_param *param;
1976         int read_only = 0;
1977         struct yaffs_options options;
1978         unsigned mount_id;
1979         int found;
1980         struct yaffs_linux_context *context_iterator;
1981         struct list_head *l;
1982
1983         if (!sb) {
1984                 printk(KERN_INFO "yaffs: sb is NULL\n");
1985                 return NULL;
1986         }
1987
1988         sb->s_magic = YAFFS_MAGIC;
1989         sb->s_op = &yaffs_super_ops;
1990         sb->s_flags |= MS_NOATIME;
1991
1992         read_only = ((sb->s_flags & MS_RDONLY) != 0);
1993
1994         sb->s_export_op = &yaffs_export_ops;
1995
1996         if (!sb->s_dev)
1997                 printk(KERN_INFO "yaffs: sb->s_dev is NULL\n");
1998         else if (!yaffs_devname(sb, devname_buf))
1999                 printk(KERN_INFO "yaffs: devname is NULL\n");
2000         else
2001                 printk(KERN_INFO "yaffs: dev is %d name is \"%s\" %s\n",
2002                        sb->s_dev,
2003                        yaffs_devname(sb, devname_buf), read_only ? "ro" : "rw");
2004
2005         if (!data_str)
2006                 data_str = "";
2007
2008         printk(KERN_INFO "yaffs: passed flags \"%s\"\n", data_str);
2009
2010         memset(&options, 0, sizeof(options));
2011
2012         if (yaffs_parse_options(&options, data_str))
2013                 /* Option parsing failed */
2014                 return NULL;
2015
2016         sb->s_blocksize = PAGE_CACHE_SIZE;
2017         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2018
2019         yaffs_trace(YAFFS_TRACE_OS,
2020                 "yaffs_read_super: Using yaffs%d", yaffs_version);
2021         yaffs_trace(YAFFS_TRACE_OS,
2022                 "yaffs_read_super: block size %d", (int)(sb->s_blocksize));
2023
2024         yaffs_trace(YAFFS_TRACE_ALWAYS,
2025                 "Attempting MTD mount of %u.%u,\"%s\"",
2026                 MAJOR(sb->s_dev), MINOR(sb->s_dev),
2027                 yaffs_devname(sb, devname_buf));
2028
2029         /* Check it's an mtd device..... */
2030         if (MAJOR(sb->s_dev) != MTD_BLOCK_MAJOR)
2031                 return NULL;    /* This isn't an mtd device */
2032
2033         /* Get the device */
2034         mtd = get_mtd_device(NULL, MINOR(sb->s_dev));
2035         if (!mtd) {
2036                 yaffs_trace(YAFFS_TRACE_ALWAYS,
2037                         "MTD device #%u doesn't appear to exist",
2038                         MINOR(sb->s_dev));
2039                 return NULL;
2040         }
2041         /* Check it's NAND */
2042         if (mtd->type != MTD_NANDFLASH) {
2043                 yaffs_trace(YAFFS_TRACE_ALWAYS,
2044                         "MTD device is not NAND it's type %d",
2045                         mtd->type);
2046                 return NULL;
2047         }
2048
2049         yaffs_trace(YAFFS_TRACE_OS, " erase %p", mtd->erase);
2050         yaffs_trace(YAFFS_TRACE_OS, " read %p", mtd->read);
2051         yaffs_trace(YAFFS_TRACE_OS, " write %p", mtd->write);
2052         yaffs_trace(YAFFS_TRACE_OS, " readoob %p", mtd->read_oob);
2053         yaffs_trace(YAFFS_TRACE_OS, " writeoob %p", mtd->write_oob);
2054         yaffs_trace(YAFFS_TRACE_OS, " block_isbad %p", mtd->block_isbad);
2055         yaffs_trace(YAFFS_TRACE_OS, " block_markbad %p", mtd->block_markbad);
2056         yaffs_trace(YAFFS_TRACE_OS, " writesize %d", mtd->writesize);
2057         yaffs_trace(YAFFS_TRACE_OS, " oobsize %d", mtd->oobsize);
2058         yaffs_trace(YAFFS_TRACE_OS, " erasesize %d", mtd->erasesize);
2059         yaffs_trace(YAFFS_TRACE_OS, " size %lld", mtd->size);
2060
2061         if (yaffs_auto_select && yaffs_version == 1 && mtd->writesize >= 2048) {
2062                 yaffs_trace(YAFFS_TRACE_ALWAYS, "auto selecting yaffs2");
2063                 yaffs_version = 2;
2064         }
2065
2066         if (yaffs_auto_select && yaffs_version == 2 && !options.inband_tags &&
2067                 mtd->writesize == 512) {
2068                 yaffs_trace(YAFFS_TRACE_ALWAYS, "auto selecting yaffs1");
2069                 yaffs_version = 1;
2070         }
2071
2072         if (yaffs_version == 2) {
2073                 /* Check for version 2 style functions */
2074                 if (!mtd->erase ||
2075                     !mtd->block_isbad ||
2076                     !mtd->block_markbad ||
2077                     !mtd->read ||
2078                     !mtd->write || !mtd->read_oob || !mtd->write_oob) {
2079                         yaffs_trace(YAFFS_TRACE_ALWAYS,
2080                                 "MTD device does not support required functions");
2081                         return NULL;
2082                 }
2083
2084                 if ((mtd->writesize < YAFFS_MIN_YAFFS2_CHUNK_SIZE ||
2085                      mtd->oobsize < YAFFS_MIN_YAFFS2_SPARE_SIZE) &&
2086                     !options.inband_tags) {
2087                         yaffs_trace(YAFFS_TRACE_ALWAYS,
2088                                 "MTD device does not have the right page sizes");
2089                         return NULL;
2090                 }
2091         } else {
2092                 /* Check for V1 style functions */
2093                 if (!mtd->erase ||
2094                     !mtd->read ||
2095                     !mtd->write || !mtd->read_oob || !mtd->write_oob) {
2096                         yaffs_trace(YAFFS_TRACE_ALWAYS,
2097                                 "MTD device does not support required functions");
2098                         return NULL;
2099                 }
2100
2101                 if (mtd->writesize < YAFFS_BYTES_PER_CHUNK ||
2102                     mtd->oobsize != YAFFS_BYTES_PER_SPARE) {
2103                         yaffs_trace(YAFFS_TRACE_ALWAYS,
2104                                 "MTD device does not support have the right page sizes");
2105                         return NULL;
2106                 }
2107         }
2108
2109         /* OK, so if we got here, we have an MTD that's NAND and looks
2110          * like it has the right capabilities
2111          * Set the struct yaffs_dev up for mtd
2112          */
2113
2114         if (!read_only && !(mtd->flags & MTD_WRITEABLE)) {
2115                 read_only = 1;
2116                 printk(KERN_INFO
2117                        "yaffs: mtd is read only, setting superblock read only");
2118                 sb->s_flags |= MS_RDONLY;
2119         }
2120
2121         dev = kmalloc(sizeof(struct yaffs_dev), GFP_KERNEL);
2122         context = kmalloc(sizeof(struct yaffs_linux_context), GFP_KERNEL);
2123
2124         if (!dev || !context) {
2125                 kfree(dev);
2126                 kfree(context);
2127                 dev = NULL;
2128                 context = NULL;
2129         }
2130
2131         if (!dev) {
2132                 /* Deep shit could not allocate device structure */
2133                 yaffs_trace(YAFFS_TRACE_ALWAYS,
2134                         "yaffs_read_super failed trying to allocate yaffs_dev");
2135                 return NULL;
2136         }
2137         memset(dev, 0, sizeof(struct yaffs_dev));
2138         param = &(dev->param);
2139
2140         memset(context, 0, sizeof(struct yaffs_linux_context));
2141         dev->os_context = context;
2142         INIT_LIST_HEAD(&(context->context_list));
2143         context->dev = dev;
2144         context->super = sb;
2145
2146         dev->read_only = read_only;
2147
2148         sb->s_fs_info = dev;
2149
2150         dev->driver_context = mtd;
2151         param->name = mtd->name;
2152
2153         /* Set up the memory size parameters.... */
2154
2155         n_blocks =
2156             YCALCBLOCKS(mtd->size,
2157                         (YAFFS_CHUNKS_PER_BLOCK * YAFFS_BYTES_PER_CHUNK));
2158
2159         param->start_block = 0;
2160         param->end_block = n_blocks - 1;
2161         param->chunks_per_block = YAFFS_CHUNKS_PER_BLOCK;
2162         param->total_bytes_per_chunk = YAFFS_BYTES_PER_CHUNK;
2163         param->n_reserved_blocks = 5;
2164         param->n_caches = (options.no_cache) ? 0 : 10;
2165         param->inband_tags = options.inband_tags;
2166
2167         param->disable_lazy_load = 1;
2168         param->enable_xattr = 1;
2169         if (options.lazy_loading_overridden)
2170                 param->disable_lazy_load = !options.lazy_loading_enabled;
2171
2172         param->defered_dir_update = 1;
2173
2174         if (options.tags_ecc_overridden)
2175                 param->no_tags_ecc = !options.tags_ecc_on;
2176
2177         param->empty_lost_n_found = 1;
2178
2179         param->refresh_period = 500;
2180
2181         if (options.empty_lost_and_found_overridden)
2182                 param->empty_lost_n_found = options.empty_lost_and_found;
2183
2184         /* ... and the functions. */
2185         if (yaffs_version == 2) {
2186                 param->write_chunk_tags_fn = nandmtd2_write_chunk_tags;
2187                 param->read_chunk_tags_fn = nandmtd2_read_chunk_tags;
2188                 param->bad_block_fn = nandmtd2_mark_block_bad;
2189                 param->query_block_fn = nandmtd2_query_block;
2190                 yaffs_dev_to_lc(dev)->spare_buffer =
2191                                 kmalloc(mtd->oobsize, GFP_NOFS);
2192                 param->is_yaffs2 = 1;
2193                 param->total_bytes_per_chunk = mtd->writesize;
2194                 param->chunks_per_block = mtd->erasesize / mtd->writesize;
2195                 n_blocks = YCALCBLOCKS(mtd->size, mtd->erasesize);
2196
2197                 param->start_block = 0;
2198                 param->end_block = n_blocks - 1;
2199         } else {
2200                 /* use the MTD interface in yaffs_mtdif1.c */
2201                 param->write_chunk_tags_fn = nandmtd1_write_chunk_tags;
2202                 param->read_chunk_tags_fn = nandmtd1_read_chunk_tags;
2203                 param->bad_block_fn = nandmtd1_mark_block_bad;
2204                 param->query_block_fn = nandmtd1_query_block;
2205                 param->is_yaffs2 = 0;
2206         }
2207         /* ... and common functions */
2208         param->erase_fn = nandmtd_erase_block;
2209         param->initialise_flash_fn = nandmtd_initialise;
2210
2211         yaffs_dev_to_lc(dev)->put_super_fn = yaffs_mtd_put_super;
2212
2213         param->sb_dirty_fn = yaffs_touch_super;
2214         param->gc_control = yaffs_gc_control_callback;
2215
2216         yaffs_dev_to_lc(dev)->super = sb;
2217
2218         param->use_nand_ecc = 1;
2219
2220         param->skip_checkpt_rd = options.skip_checkpoint_read;
2221         param->skip_checkpt_wr = options.skip_checkpoint_write;
2222
2223         mutex_lock(&yaffs_context_lock);
2224         /* Get a mount id */
2225         for (mount_id = 0, found = 0; !found; mount_id++) {
2226                 found = 1;
2227                 list_for_each(l, &yaffs_context_list) {
2228                         context_iterator =
2229                                 list_entry(l, struct yaffs_linux_context,
2230                                         context_list);
2231                         if (context_iterator->mount_id == mount_id)
2232                                 found = 0;
2233                 }
2234         }
2235         context->mount_id = mount_id;
2236
2237         list_add_tail(&(yaffs_dev_to_lc(dev)->context_list),
2238                       &yaffs_context_list);
2239         mutex_unlock(&yaffs_context_lock);
2240
2241         /* Directory search handling... */
2242         INIT_LIST_HEAD(&(yaffs_dev_to_lc(dev)->search_contexts));
2243         param->remove_obj_fn = yaffs_remove_obj_callback;
2244
2245         mutex_init(&(yaffs_dev_to_lc(dev)->gross_lock));
2246
2247         yaffs_gross_lock(dev);
2248
2249         err = yaffs_guts_initialise(dev);
2250
2251         yaffs_trace(YAFFS_TRACE_OS,
2252                 "yaffs_read_super: guts initialised %s",
2253                 (err == YAFFS_OK) ? "OK" : "FAILED");
2254
2255         if (err == YAFFS_OK)
2256                 yaffs_bg_start(dev);
2257
2258         if (!context->bg_thread)
2259                 param->defered_dir_update = 0;
2260
2261         sb->s_maxbytes = yaffs_max_file_size(dev);
2262
2263         yaffs_trace(YAFFS_TRACE_OS,
2264                 "yaffs_readpage_nolock at %lld, size %08x",
2265                 (long long)pos,
2266                 (unsigned)PAGE_CACHE_SIZE);
2267         /* Release lock before yaffs_get_inode() */
2268         yaffs_gross_unlock(dev);
2269
2270         /* Create root inode */
2271         if (err == YAFFS_OK)
2272                 inode = yaffs_get_inode(sb, S_IFDIR | 0755, 0, yaffs_root(dev));
2273
2274         if (!inode)
2275                 return NULL;
2276
2277         inode->i_op = &yaffs_dir_inode_operations;
2278         inode->i_fop = &yaffs_dir_operations;
2279
2280         yaffs_trace(YAFFS_TRACE_OS, "yaffs_read_super: got root inode");
2281
2282         root = d_alloc_root(inode);
2283
2284         yaffs_trace(YAFFS_TRACE_OS, "yaffs_read_super: d_alloc_root done");
2285
2286         if (!root) {
2287                 iput(inode);
2288                 return NULL;
2289         }
2290         sb->s_root = root;
2291         sb->s_dirt = !dev->is_checkpointed;
2292         yaffs_trace(YAFFS_TRACE_ALWAYS,
2293                 "yaffs_read_super: is_checkpointed %d",
2294                 dev->is_checkpointed);
2295
2296         yaffs_trace(YAFFS_TRACE_OS, "yaffs_read_super: done");
2297         return sb;
2298 }
2299
2300 static int yaffs_internal_read_super_mtd(struct super_block *sb, void *data,
2301                                          int silent)
2302 {
2303         return yaffs_internal_read_super(1, sb, data, silent) ? 0 : -EINVAL;
2304 }
2305
2306 static struct dentry *yaffs_mount(struct file_system_type *fs,
2307                             int flags, const char *dev_name,
2308                             void *data)
2309 {
2310         return mount_bdev(fs, flags, dev_name, data,
2311                            yaffs_internal_read_super_mtd);
2312 }
2313
2314 static struct file_system_type yaffs_fs_type = {
2315         .owner = THIS_MODULE,
2316         .name = "yaffs",
2317         .mount = yaffs_mount,
2318         .kill_sb = kill_block_super,
2319         .fs_flags = FS_REQUIRES_DEV,
2320 };
2321
2322 static int yaffs2_internal_read_super_mtd(struct super_block *sb, void *data,
2323                                           int silent)
2324 {
2325         return yaffs_internal_read_super(2, sb, data, silent) ? 0 : -EINVAL;
2326 }
2327
2328 static struct dentry *yaffs2_mount(struct file_system_type *fs,
2329                              int flags, const char *dev_name, void *data)
2330 {
2331         return mount_bdev(fs, flags, dev_name, data,
2332                            yaffs2_internal_read_super_mtd);
2333 }
2334
2335 static struct file_system_type yaffs2_fs_type = {
2336         .owner = THIS_MODULE,
2337         .name = "yaffs2",
2338         .mount = yaffs2_mount,
2339         .kill_sb = kill_block_super,
2340         .fs_flags = FS_REQUIRES_DEV,
2341 };
2342
2343
2344 static struct proc_dir_entry *my_proc_entry;
2345
2346 static char *yaffs_dump_dev_part0(char *buf, struct yaffs_dev *dev)
2347 {
2348         struct yaffs_param *param = &dev->param;
2349
2350         buf += sprintf(buf, "start_block........... %d\n", param->start_block);
2351         buf += sprintf(buf, "end_block............. %d\n", param->end_block);
2352         buf += sprintf(buf, "total_bytes_per_chunk. %d\n",
2353                         param->total_bytes_per_chunk);
2354         buf += sprintf(buf, "use_nand_ecc.......... %d\n",
2355                         param->use_nand_ecc);
2356         buf += sprintf(buf, "no_tags_ecc........... %d\n", param->no_tags_ecc);
2357         buf += sprintf(buf, "is_yaffs2............. %d\n", param->is_yaffs2);
2358         buf += sprintf(buf, "inband_tags........... %d\n", param->inband_tags);
2359         buf += sprintf(buf, "empty_lost_n_found.... %d\n",
2360                         param->empty_lost_n_found);
2361         buf += sprintf(buf, "disable_lazy_load..... %d\n",
2362                         param->disable_lazy_load);
2363         buf += sprintf(buf, "refresh_period........ %d\n",
2364                         param->refresh_period);
2365         buf += sprintf(buf, "n_caches.............. %d\n", param->n_caches);
2366         buf += sprintf(buf, "n_reserved_blocks..... %d\n",
2367                         param->n_reserved_blocks);
2368         buf += sprintf(buf, "always_check_erased... %d\n",
2369                         param->always_check_erased);
2370
2371         return buf;
2372 }
2373
2374 static char *yaffs_dump_dev_part1(char *buf, struct yaffs_dev *dev)
2375 {
2376         buf += sprintf(buf, "max file size......... %lld\n",
2377                         (long long) yaffs_max_file_size(dev));
2378         buf += sprintf(buf, "data_bytes_per_chunk.. %d\n",
2379                     dev->data_bytes_per_chunk);
2380         buf += sprintf(buf, "chunk_grp_bits........ %d\n", dev->chunk_grp_bits);
2381         buf += sprintf(buf, "chunk_grp_size........ %d\n", dev->chunk_grp_size);
2382         buf +=
2383             sprintf(buf, "n_erased_blocks....... %d\n", dev->n_erased_blocks);
2384         buf +=
2385             sprintf(buf, "blocks_in_checkpt..... %d\n", dev->blocks_in_checkpt);
2386         buf += sprintf(buf, "\n");
2387         buf += sprintf(buf, "n_tnodes.............. %d\n", dev->n_tnodes);
2388         buf += sprintf(buf, "n_obj................. %d\n", dev->n_obj);
2389         buf += sprintf(buf, "n_free_chunks......... %d\n", dev->n_free_chunks);
2390         buf += sprintf(buf, "\n");
2391         buf += sprintf(buf, "n_page_writes......... %u\n", dev->n_page_writes);
2392         buf += sprintf(buf, "n_page_reads.......... %u\n", dev->n_page_reads);
2393         buf += sprintf(buf, "n_erasures............ %u\n", dev->n_erasures);
2394         buf += sprintf(buf, "n_gc_copies........... %u\n", dev->n_gc_copies);
2395         buf += sprintf(buf, "all_gcs............... %u\n", dev->all_gcs);
2396         buf +=
2397             sprintf(buf, "passive_gc_count...... %u\n", dev->passive_gc_count);
2398         buf +=
2399             sprintf(buf, "oldest_dirty_gc_count. %u\n",
2400                     dev->oldest_dirty_gc_count);
2401         buf += sprintf(buf, "n_gc_blocks........... %u\n", dev->n_gc_blocks);
2402         buf += sprintf(buf, "bg_gcs................ %u\n", dev->bg_gcs);
2403         buf +=
2404             sprintf(buf, "n_retried_writes...... %u\n", dev->n_retried_writes);
2405         buf +=
2406             sprintf(buf, "n_retired_blocks...... %u\n", dev->n_retired_blocks);
2407         buf += sprintf(buf, "n_ecc_fixed........... %u\n", dev->n_ecc_fixed);
2408         buf += sprintf(buf, "n_ecc_unfixed......... %u\n", dev->n_ecc_unfixed);
2409         buf +=
2410             sprintf(buf, "n_tags_ecc_fixed...... %u\n", dev->n_tags_ecc_fixed);
2411         buf +=
2412             sprintf(buf, "n_tags_ecc_unfixed.... %u\n",
2413                     dev->n_tags_ecc_unfixed);
2414         buf += sprintf(buf, "cache_hits............ %u\n", dev->cache_hits);
2415         buf +=
2416             sprintf(buf, "n_deleted_files....... %u\n", dev->n_deleted_files);
2417         buf +=
2418             sprintf(buf, "n_unlinked_files...... %u\n", dev->n_unlinked_files);
2419         buf += sprintf(buf, "refresh_count......... %u\n", dev->refresh_count);
2420         buf += sprintf(buf, "n_bg_deletions........ %u\n", dev->n_bg_deletions);
2421
2422         return buf;
2423 }
2424
2425 static int yaffs_proc_read(char *page,
2426                            char **start,
2427                            off_t offset, int count, int *eof, void *data)
2428 {
2429         struct list_head *item;
2430         char *buf = page;
2431         int step = offset;
2432         int n = 0;
2433
2434         /* Get proc_file_read() to step 'offset' by one on each sucessive call.
2435          * We use 'offset' (*ppos) to indicate where we are in dev_list.
2436          * This also assumes the user has posted a read buffer large
2437          * enough to hold the complete output; but that's life in /proc.
2438          */
2439
2440         *(int *)start = 1;
2441
2442         /* Print header first */
2443         if (step == 0)
2444                 buf += sprintf(buf, "YAFFS built:" __DATE__ " " __TIME__ "\n");
2445         else if (step == 1)
2446                 buf += sprintf(buf, "\n");
2447         else {
2448                 step -= 2;
2449
2450                 mutex_lock(&yaffs_context_lock);
2451
2452                 /* Locate and print the Nth entry.
2453                  * Order N-squared but N is small. */
2454                 list_for_each(item, &yaffs_context_list) {
2455                         struct yaffs_linux_context *dc =
2456                             list_entry(item, struct yaffs_linux_context,
2457                                        context_list);
2458                         struct yaffs_dev *dev = dc->dev;
2459
2460                         if (n < (step & ~1)) {
2461                                 n += 2;
2462                                 continue;
2463                         }
2464                         if ((step & 1) == 0) {
2465                                 buf +=
2466                                     sprintf(buf, "\nDevice %d \"%s\"\n", n,
2467                                             dev->param.name);
2468                                 buf = yaffs_dump_dev_part0(buf, dev);
2469                         } else {
2470                                 buf = yaffs_dump_dev_part1(buf, dev);
2471                         }
2472
2473                         break;
2474                 }
2475                 mutex_unlock(&yaffs_context_lock);
2476         }
2477
2478         return buf - page < count ? buf - page : count;
2479 }
2480
2481
2482
2483 /* Stuff to handle installation of file systems */
2484 struct file_system_to_install {
2485         struct file_system_type *fst;
2486         int installed;
2487 };
2488
2489 static struct file_system_to_install fs_to_install[] = {
2490         {&yaffs_fs_type, 0},
2491         {&yaffs2_fs_type, 0},
2492         {NULL, 0}
2493 };
2494
2495 static int __init init_yaffs_fs(void)
2496 {
2497         int error = 0;
2498         struct file_system_to_install *fsinst;
2499
2500         yaffs_trace(YAFFS_TRACE_ALWAYS,
2501                 "yaffs built " __DATE__ " " __TIME__ " Installing.");
2502
2503         mutex_init(&yaffs_context_lock);
2504
2505         /* Install the proc_fs entries */
2506         my_proc_entry = create_proc_entry("yaffs",
2507                                           S_IRUGO | S_IFREG, NULL);
2508
2509         if (my_proc_entry) {
2510                 my_proc_entry->write_proc = NULL;
2511                 my_proc_entry->read_proc = yaffs_proc_read;
2512                 my_proc_entry->data = NULL;
2513         } else {
2514                 return -ENOMEM;
2515         }
2516
2517
2518         /* Now add the file system entries */
2519
2520         fsinst = fs_to_install;
2521
2522         while (fsinst->fst && !error) {
2523                 error = register_filesystem(fsinst->fst);
2524                 if (!error)
2525                         fsinst->installed = 1;
2526                 fsinst++;
2527         }
2528
2529         /* Any errors? uninstall  */
2530         if (error) {
2531                 fsinst = fs_to_install;
2532
2533                 while (fsinst->fst) {
2534                         if (fsinst->installed) {
2535                                 unregister_filesystem(fsinst->fst);
2536                                 fsinst->installed = 0;
2537                         }
2538                         fsinst++;
2539                 }
2540         }
2541
2542         return error;
2543 }
2544
2545 static void __exit exit_yaffs_fs(void)
2546 {
2547
2548         struct file_system_to_install *fsinst;
2549
2550         yaffs_trace(YAFFS_TRACE_ALWAYS,
2551                 "yaffs built " __DATE__ " " __TIME__ " removing.");
2552
2553         remove_proc_entry("yaffs", NULL);
2554
2555         fsinst = fs_to_install;
2556
2557         while (fsinst->fst) {
2558                 if (fsinst->installed) {
2559                         unregister_filesystem(fsinst->fst);
2560                         fsinst->installed = 0;
2561                 }
2562                 fsinst++;
2563         }
2564 }
2565
2566 module_init(init_yaffs_fs)
2567 module_exit(exit_yaffs_fs)
2568
2569 MODULE_DESCRIPTION("YAFFS2 - a NAND specific flash file system");
2570 MODULE_AUTHOR("Charles Manning, Aleph One Ltd., 2002-2011");
2571 MODULE_LICENSE("GPL");