yaffs_vfs_single.c

   1 /*
   2  * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
   3  *
   4  * Copyright (C) 2002-2010 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
  40 #include <linux/kernel.h>
  41 #include <linux/module.h>
  42 #include <linux/slab.h>
  43 #include <linux/init.h>
  44 #include <linux/fs.h>
  45 #include <linux/proc_fs.h>
  46 #include <linux/smp_lock.h>
  47 #include <linux/pagemap.h>
  48 #include <linux/mtd/mtd.h>
  49 #include <linux/interrupt.h>
  50 #include <linux/string.h>
  51 #include <linux/ctype.h>
  52 #include <linux/namei.h>
  53 #include <linux/exportfs.h>
  54 #include <linux/kthread.h>
  55 #include <linux/delay.h>
  56 #include <linux/freezer.h>
  57
  58 #include <asm/div64.h>
  59
  60 #include <linux/statfs.h>
  61
  62 #define yaffs_devname(sb, buf)  bdevname(sb->s_bdev, buf)
  63
  64 #define YPROC_ROOT  NULL
  65
  66 #define Y_INIT_TIMER(a) init_timer_on_stack(a)
  67
  68 #define WRITE_SIZE_STR "writesize"
  69 #define WRITE_SIZE(mtd) ((mtd)->writesize)
  70
  71 static uint32_t YCALCBLOCKS(uint64_t partition_size, uint32_t block_size)
  72 {
  73         uint64_t result = partition_size;
  74         do_div(result, block_size);
  75         return (uint32_t) result;
  76 }
  77
  78 #include <linux/uaccess.h>
  79 #include <linux/mtd/mtd.h>
  80
  81 #include "yportenv.h"
  82 #include "yaffs_trace.h"
  83 #include "yaffs_guts.h"
  84 #include "yaffs_attribs.h"
  85
  86 #include "yaffs_linux.h"
  87
  88 #include "yaffs_mtdif.h"
  89 #include "yaffs_mtdif1.h"
  90 #include "yaffs_mtdif2.h"
  91
  92 unsigned int yaffs_trace_mask = YAFFS_TRACE_BAD_BLOCKS | YAFFS_TRACE_ALWAYS;
  93 unsigned int yaffs_wr_attempts = YAFFS_WR_ATTEMPTS;
  94 unsigned int yaffs_auto_checkpoint = 1;
  95 unsigned int yaffs_gc_control = 1;
  96 unsigned int yaffs_bg_enable = 1;
  97
  98 /* Module Parameters */
  99 module_param(yaffs_trace_mask, uint, 0644);
 100 module_param(yaffs_wr_attempts, uint, 0644);
 101 module_param(yaffs_auto_checkpoint, uint, 0644);
 102 module_param(yaffs_gc_control, uint, 0644);
 103 module_param(yaffs_bg_enable, uint, 0644);
 104
 105
 106 #define yaffs_inode_to_obj_lv(iptr) ((iptr)->i_private)
 107 #define yaffs_inode_to_obj(iptr) ((struct yaffs_obj *)(yaffs_inode_to_obj_lv(iptr)))
 108 #define yaffs_dentry_to_obj(dptr) yaffs_inode_to_obj((dptr)->d_inode)
 109 #define yaffs_super_to_dev(sb)  ((struct yaffs_dev *)sb->s_fs_info)
 110
 111 #define update_dir_time(dir) do {\
 112                         (dir)->i_ctime = (dir)->i_mtime = CURRENT_TIME; \
 113                 } while(0)
 114
 115
 116 static unsigned yaffs_gc_control_callback(struct yaffs_dev *dev)
 117 {
 118         return yaffs_gc_control;
 119 }
 120
 121 static void yaffs_gross_lock(struct yaffs_dev *dev)
 122 {
 123         yaffs_trace(YAFFS_TRACE_LOCK, "yaffs locking %p", current);
 124         mutex_lock(&(yaffs_dev_to_lc(dev)->gross_lock));
 125         yaffs_trace(YAFFS_TRACE_LOCK, "yaffs locked %p", current);
 126 }
 127
 128 static void yaffs_gross_unlock(struct yaffs_dev *dev)
 129 {
 130         yaffs_trace(YAFFS_TRACE_LOCK, "yaffs unlocking %p", current);
 131         mutex_unlock(&(yaffs_dev_to_lc(dev)->gross_lock));
 132 }
 133
 134 static void yaffs_fill_inode_from_obj(struct inode *inode,
 135                                       struct yaffs_obj *obj);
 136
 137 static struct inode *yaffs_iget(struct super_block *sb, unsigned long ino)
 138 {
 139         struct inode *inode;
 140         struct yaffs_obj *obj;
 141         struct yaffs_dev *dev = yaffs_super_to_dev(sb);
 142
 143         yaffs_trace(YAFFS_TRACE_OS, "yaffs_iget for %lu", ino);
 144
 145         inode = iget_locked(sb, ino);
 146         if (!inode)
 147                 return ERR_PTR(-ENOMEM);
 148         if (!(inode->i_state & I_NEW))
 149                 return inode;
 150
 151         /* NB This is called as a side effect of other functions, but
 152          * we had to release the lock to prevent deadlocks, so
 153          * need to lock again.
 154          */
 155
 156         yaffs_gross_lock(dev);
 157
 158         obj = yaffs_find_by_number(dev, inode->i_ino);
 159
 160         yaffs_fill_inode_from_obj(inode, obj);
 161
 162         yaffs_gross_unlock(dev);
 163
 164         unlock_new_inode(inode);
 165         return inode;
 166 }
 167
 168 struct inode *yaffs_get_inode(struct super_block *sb, int mode, int dev,
 169                               struct yaffs_obj *obj)
 170 {
 171         struct inode *inode;
 172
 173         if (!sb) {
 174                 yaffs_trace(YAFFS_TRACE_OS,
 175                         "yaffs_get_inode for NULL super_block!!");
 176                 return NULL;
 177
 178         }
 179
 180         if (!obj) {
 181                 yaffs_trace(YAFFS_TRACE_OS,
 182                         "yaffs_get_inode for NULL object!!");
 183                 return NULL;
 184
 185         }
 186
 187         yaffs_trace(YAFFS_TRACE_OS,
 188                 "yaffs_get_inode for object %d",
 189                 obj->obj_id);
 190
 191         inode = yaffs_iget(sb, obj->obj_id);
 192         if (IS_ERR(inode))
 193                 return NULL;
 194
 195         /* NB Side effect: iget calls back to yaffs_read_inode(). */
 196         /* iget also increments the inode's i_count */
 197         /* NB You can't be holding gross_lock or deadlock will happen! */
 198
 199         return inode;
 200 }
 201
 202 static int yaffs_mknod(struct inode *dir, struct dentry *dentry, int mode,
 203                        dev_t rdev)
 204 {
 205         struct inode *inode;
 206
 207         struct yaffs_obj *obj = NULL;
 208         struct yaffs_dev *dev;
 209
 210         struct yaffs_obj *parent = yaffs_inode_to_obj(dir);
 211
 212         int error = -ENOSPC;
 213         uid_t uid = current->cred->fsuid;
 214         gid_t gid =
 215             (dir->i_mode & S_ISGID) ? dir->i_gid : current->cred->fsgid;
 216
 217         if ((dir->i_mode & S_ISGID) && S_ISDIR(mode))
 218                 mode |= S_ISGID;
 219
 220         if (parent) {
 221                 yaffs_trace(YAFFS_TRACE_OS,
 222                         "yaffs_mknod: parent object %d type %d",
 223                         parent->obj_id, parent->variant_type);
 224         } else {
 225                 yaffs_trace(YAFFS_TRACE_OS,
 226                         "yaffs_mknod: could not get parent object");
 227                 return -EPERM;
 228         }
 229
 230         yaffs_trace(YAFFS_TRACE_OS,
 231                 "yaffs_mknod: making oject for %s, mode %x dev %x",
 232                 dentry->d_name.name, mode, rdev);
 233
 234         dev = parent->my_dev;
 235
 236         yaffs_gross_lock(dev);
 237
 238         switch (mode & S_IFMT) {
 239         default:
 240                 /* Special (socket, fifo, device...) */
 241                 yaffs_trace(YAFFS_TRACE_OS, "yaffs_mknod: making special");
 242                 obj =
 243                     yaffs_create_special(parent, dentry->d_name.name, mode, uid,
 244                                          gid, old_encode_dev(rdev));
 245                 break;
 246         case S_IFREG:           /* file          */
 247                 yaffs_trace(YAFFS_TRACE_OS, "yaffs_mknod: making file");
 248                 obj = yaffs_create_file(parent, dentry->d_name.name, mode, uid,
 249                                         gid);
 250                 break;
 251         case S_IFDIR:           /* directory */
 252                 yaffs_trace(YAFFS_TRACE_OS, "yaffs_mknod: making directory");
 253                 obj = yaffs_create_dir(parent, dentry->d_name.name, mode,
 254                                        uid, gid);
 255                 break;
 256         case S_IFLNK:           /* symlink */
 257                 yaffs_trace(YAFFS_TRACE_OS, "yaffs_mknod: making symlink");
 258                 obj = NULL;     /* Do we ever get here? */
 259                 break;
 260         }
 261
 262         /* Can not call yaffs_get_inode() with gross lock held */
 263         yaffs_gross_unlock(dev);
 264
 265         if (obj) {
 266                 inode = yaffs_get_inode(dir->i_sb, mode, rdev, obj);
 267                 d_instantiate(dentry, inode);
 268                 update_dir_time(dir);
 269                 yaffs_trace(YAFFS_TRACE_OS,
 270                         "yaffs_mknod created object %d count = %d",
 271                         obj->obj_id, atomic_read(&inode->i_count));
 272                 error = 0;
 273                 yaffs_fill_inode_from_obj(dir, parent);
 274         } else {
 275                 yaffs_trace(YAFFS_TRACE_OS, "yaffs_mknod failed making object");
 276                 error = -ENOMEM;
 277         }
 278
 279         return error;
 280 }
 281
 282 static int yaffs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 283 {
 284         return yaffs_mknod(dir, dentry, mode | S_IFDIR, 0);
 285 }
 286
 287 static int yaffs_create(struct inode *dir, struct dentry *dentry, int mode,
 288                         struct nameidata *n)
 289 {
 290         return yaffs_mknod(dir, dentry, mode | S_IFREG, 0);
 291 }
 292
 293 static int yaffs_link(struct dentry *old_dentry, struct inode *dir,
 294                       struct dentry *dentry)
 295 {
 296         struct inode *inode = old_dentry->d_inode;
 297         struct yaffs_obj *obj = NULL;
 298         struct yaffs_obj *link = NULL;
 299         struct yaffs_dev *dev;
 300
 301         yaffs_trace(YAFFS_TRACE_OS, "yaffs_link");
 302
 303         obj = yaffs_inode_to_obj(inode);
 304         dev = obj->my_dev;
 305
 306         yaffs_gross_lock(dev);
 307
 308         if (!S_ISDIR(inode->i_mode))    /* Don't link directories */
 309                 link =
 310                     yaffs_link_obj(yaffs_inode_to_obj(dir), dentry->d_name.name,
 311                                    obj);
 312
 313         if (link) {
 314                 old_dentry->d_inode->i_nlink = yaffs_get_obj_link_count(obj);
 315                 d_instantiate(dentry, old_dentry->d_inode);
 316                 atomic_inc(&old_dentry->d_inode->i_count);
 317                 yaffs_trace(YAFFS_TRACE_OS,
 318                         "yaffs_link link count %d i_count %d",
 319                         old_dentry->d_inode->i_nlink,
 320                         atomic_read(&old_dentry->d_inode->i_count));
 321         }
 322
 323         yaffs_gross_unlock(dev);
 324
 325         if (link) {
 326                 update_dir_time(dir);
 327                 return 0;
 328         }
 329
 330         return -EPERM;
 331 }
 332
 333 static int yaffs_symlink(struct inode *dir, struct dentry *dentry,
 334                          const char *symname)
 335 {
 336         struct yaffs_obj *obj;
 337         struct yaffs_dev *dev;
 338         uid_t uid = current->cred->fsuid;
 339         gid_t gid =
 340             (dir->i_mode & S_ISGID) ? dir->i_gid : current->cred->fsgid;
 341
 342         yaffs_trace(YAFFS_TRACE_OS, "yaffs_symlink");
 343
 344         dev = yaffs_inode_to_obj(dir)->my_dev;
 345         yaffs_gross_lock(dev);
 346         obj = yaffs_create_symlink(yaffs_inode_to_obj(dir), dentry->d_name.name,
 347                                    S_IFLNK | S_IRWXUGO, uid, gid, symname);
 348         yaffs_gross_unlock(dev);
 349
 350         if (obj) {
 351                 struct inode *inode;
 352
 353                 inode = yaffs_get_inode(dir->i_sb, obj->yst_mode, 0, obj);
 354                 d_instantiate(dentry, inode);
 355                 update_dir_time(dir);
 356                 yaffs_trace(YAFFS_TRACE_OS, "symlink created OK");
 357                 return 0;
 358         } else {
 359                 yaffs_trace(YAFFS_TRACE_OS, "symlink not created");
 360         }
 361
 362         return -ENOMEM;
 363 }
 364
 365 static struct dentry *yaffs_lookup(struct inode *dir, struct dentry *dentry,
 366                                    struct nameidata *n)
 367 {
 368         struct yaffs_obj *obj;
 369         struct inode *inode = NULL;
 370
 371         struct yaffs_dev *dev = yaffs_inode_to_obj(dir)->my_dev;
 372
 373         if (current != yaffs_dev_to_lc(dev)->readdir_process)
 374                 yaffs_gross_lock(dev);
 375
 376         yaffs_trace(YAFFS_TRACE_OS,
 377                 "yaffs_lookup for %d:%s",
 378                 yaffs_inode_to_obj(dir)->obj_id, dentry->d_name.name);
 379
 380         obj = yaffs_find_by_name(yaffs_inode_to_obj(dir), dentry->d_name.name);
 381
 382         obj = yaffs_get_equivalent_obj(obj);    /* in case it was a hardlink */
 383
 384         /* Can't hold gross lock when calling yaffs_get_inode() */
 385         if (current != yaffs_dev_to_lc(dev)->readdir_process)
 386                 yaffs_gross_unlock(dev);
 387
 388         if (obj) {
 389                 yaffs_trace(YAFFS_TRACE_OS,
 390                         "yaffs_lookup found %d", obj->obj_id);
 391
 392                 inode = yaffs_get_inode(dir->i_sb, obj->yst_mode, 0, obj);
 393
 394                 if (inode) {
 395                         yaffs_trace(YAFFS_TRACE_OS, "yaffs_loookup dentry");
 396                         d_add(dentry, inode);
 397                         /* return dentry; */
 398                         return NULL;
 399                 }
 400
 401         } else {
 402                 yaffs_trace(YAFFS_TRACE_OS, "yaffs_lookup not found");
 403
 404         }
 405
 406         d_add(dentry, inode);
 407
 408         return NULL;
 409 }
 410
 411 static int yaffs_unlink(struct inode *dir, struct dentry *dentry)
 412 {
 413         int ret_val;
 414
 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                 dentry->d_inode->i_nlink--;
 430                 dir->i_version++;
 431                 yaffs_gross_unlock(dev);
 432                 mark_inode_dirty(dentry->d_inode);
 433                 update_dir_time(dir);
 434                 return 0;
 435         }
 436         yaffs_gross_unlock(dev);
 437         return -ENOTEMPTY;
 438 }
 439
 440 static int yaffs_sync_object(struct file *file, int datasync)
 441 {
 442
 443         struct yaffs_obj *obj;
 444         struct yaffs_dev *dev;
 445         struct dentry *dentry = file->f_path.dentry;
 446
 447         obj = yaffs_dentry_to_obj(dentry);
 448
 449         dev = obj->my_dev;
 450
 451         yaffs_trace(YAFFS_TRACE_OS | YAFFS_TRACE_SYNC, "yaffs_sync_object");
 452         yaffs_gross_lock(dev);
 453         yaffs_flush_file(obj, 1, datasync);
 454         yaffs_gross_unlock(dev);
 455         return 0;
 456 }
 457 /*
 458  * The VFS layer already does all the dentry stuff for rename.
 459  *
 460  * NB: POSIX says you can rename an object over an old object of the same name
 461  */
 462 static int yaffs_rename(struct inode *old_dir, struct dentry *old_dentry,
 463                         struct inode *new_dir, struct dentry *new_dentry)
 464 {
 465         struct yaffs_dev *dev;
 466         int ret_val = YAFFS_FAIL;
 467         struct yaffs_obj *target;
 468
 469         yaffs_trace(YAFFS_TRACE_OS, "yaffs_rename");
 470         dev = yaffs_inode_to_obj(old_dir)->my_dev;
 471
 472         yaffs_gross_lock(dev);
 473
 474         /* Check if the target is an existing directory that is not empty. */
 475         target = yaffs_find_by_name(yaffs_inode_to_obj(new_dir),
 476                                     new_dentry->d_name.name);
 477
 478         if (target && target->variant_type == YAFFS_OBJECT_TYPE_DIRECTORY &&
 479             !list_empty(&target->variant.dir_variant.children)) {
 480
 481                 yaffs_trace(YAFFS_TRACE_OS, "target is non-empty dir");
 482
 483                 ret_val = YAFFS_FAIL;
 484         } else {
 485                 /* Now does unlinking internally using shadowing mechanism */
 486                 yaffs_trace(YAFFS_TRACE_OS, "calling yaffs_rename_obj");
 487
 488                 ret_val = yaffs_rename_obj(yaffs_inode_to_obj(old_dir),
 489                                            old_dentry->d_name.name,
 490                                            yaffs_inode_to_obj(new_dir),
 491                                            new_dentry->d_name.name);
 492         }
 493         yaffs_gross_unlock(dev);
 494
 495         if (ret_val == YAFFS_OK) {
 496                 if (target) {
 497                         new_dentry->d_inode->i_nlink--;
 498                         mark_inode_dirty(new_dentry->d_inode);
 499                 }
 500
 501                 update_dir_time(old_dir);
 502                 if (old_dir != new_dir)
 503                         update_dir_time(new_dir);
 504                 return 0;
 505         } else {
 506                 return -ENOTEMPTY;
 507         }
 508 }
 509
 510 static int yaffs_setattr(struct dentry *dentry, struct iattr *attr)
 511 {
 512         struct inode *inode = dentry->d_inode;
 513         int error = 0;
 514         struct yaffs_dev *dev;
 515
 516         yaffs_trace(YAFFS_TRACE_OS,
 517                 "yaffs_setattr of object %d",
 518                 yaffs_inode_to_obj(inode)->obj_id);
 519
 520         /* Fail if a requested resize >= 2GB */
 521         if (attr->ia_valid & ATTR_SIZE && (attr->ia_size >> 31))
 522                 error = -EINVAL;
 523
 524         if (error == 0)
 525                 error = inode_change_ok(inode, attr);
 526         if (error == 0) {
 527                 int result;
 528                 if (!error) {
 529                         setattr_copy(inode, attr);
 530                         yaffs_trace(YAFFS_TRACE_OS, "inode_setattr called");
 531                         if (attr->ia_valid & ATTR_SIZE) {
 532                                 truncate_setsize(inode, attr->ia_size);
 533                                 inode->i_blocks = (inode->i_size + 511) >> 9;
 534                         }
 535                 }
 536                 dev = yaffs_inode_to_obj(inode)->my_dev;
 537                 if (attr->ia_valid & ATTR_SIZE) {
 538                         yaffs_trace(YAFFS_TRACE_OS, "resize to %d(%x)",
 539                                            (int)(attr->ia_size),
 540                                            (int)(attr->ia_size));
 541                 }
 542                 yaffs_gross_lock(dev);
 543                 result = yaffs_set_attribs(yaffs_inode_to_obj(inode), attr);
 544                 if (result == YAFFS_OK) {
 545                         error = 0;
 546                 } else {
 547                         error = -EPERM;
 548                 }
 549                 yaffs_gross_unlock(dev);
 550
 551         }
 552
 553         yaffs_trace(YAFFS_TRACE_OS, "yaffs_setattr done returning %d", error);
 554
 555         return error;
 556 }
 557
 558 #ifdef CONFIG_YAFFS_XATTR
 559 static int yaffs_setxattr(struct dentry *dentry, const char *name,
 560                    const void *value, size_t size, int flags)
 561 {
 562         struct inode *inode = dentry->d_inode;
 563         int error = 0;
 564         struct yaffs_dev *dev;
 565         struct yaffs_obj *obj = yaffs_inode_to_obj(inode);
 566
 567         yaffs_trace(YAFFS_TRACE_OS, "yaffs_setxattr of object %d", obj->obj_id);
 568
 569         if (error == 0) {
 570                 int result;
 571                 dev = obj->my_dev;
 572                 yaffs_gross_lock(dev);
 573                 result = yaffs_set_xattrib(obj, name, value, size, flags);
 574                 if (result == YAFFS_OK)
 575                         error = 0;
 576                 else if (result < 0)
 577                         error = result;
 578                 yaffs_gross_unlock(dev);
 579
 580         }
 581         yaffs_trace(YAFFS_TRACE_OS, "yaffs_setxattr done returning %d", error);
 582
 583         return error;
 584 }
 585
 586 static ssize_t yaffs_getxattr(struct dentry * dentry, const char *name, void *buff,
 587                        size_t size)
 588 {
 589         struct inode *inode = dentry->d_inode;
 590         int error = 0;
 591         struct yaffs_dev *dev;
 592         struct yaffs_obj *obj = yaffs_inode_to_obj(inode);
 593
 594         yaffs_trace(YAFFS_TRACE_OS,
 595                 "yaffs_getxattr \"%s\" from object %d",
 596                 name, obj->obj_id);
 597
 598         if (error == 0) {
 599                 dev = obj->my_dev;
 600                 yaffs_gross_lock(dev);
 601                 error = yaffs_get_xattrib(obj, name, buff, size);
 602                 yaffs_gross_unlock(dev);
 603
 604         }
 605         yaffs_trace(YAFFS_TRACE_OS, "yaffs_getxattr done returning %d", error);
 606
 607         return error;
 608 }
 609
 610 static int yaffs_removexattr(struct dentry *dentry, const char *name)
 611 {
 612         struct inode *inode = dentry->d_inode;
 613         int error = 0;
 614         struct yaffs_dev *dev;
 615         struct yaffs_obj *obj = yaffs_inode_to_obj(inode);
 616
 617         yaffs_trace(YAFFS_TRACE_OS,
 618                 "yaffs_removexattr of object %d", obj->obj_id);
 619
 620         if (error == 0) {
 621                 int result;
 622                 dev = obj->my_dev;
 623                 yaffs_gross_lock(dev);
 624                 result = yaffs_remove_xattrib(obj, name);
 625                 if (result == YAFFS_OK)
 626                         error = 0;
 627                 else if (result < 0)
 628                         error = result;
 629                 yaffs_gross_unlock(dev);
 630
 631         }
 632         yaffs_trace(YAFFS_TRACE_OS,
 633                 "yaffs_removexattr done returning %d", error);
 634
 635         return error;
 636 }
 637
 638 static ssize_t yaffs_listxattr(struct dentry * dentry, char *buff, size_t size)
 639 {
 640         struct inode *inode = dentry->d_inode;
 641         int error = 0;
 642         struct yaffs_dev *dev;
 643         struct yaffs_obj *obj = yaffs_inode_to_obj(inode);
 644
 645         yaffs_trace(YAFFS_TRACE_OS,
 646                 "yaffs_listxattr of object %d", obj->obj_id);
 647
 648         if (error == 0) {
 649                 dev = obj->my_dev;
 650                 yaffs_gross_lock(dev);
 651                 error = yaffs_list_xattrib(obj, buff, size);
 652                 yaffs_gross_unlock(dev);
 653
 654         }
 655         yaffs_trace(YAFFS_TRACE_OS,
 656                 "yaffs_listxattr done returning %d", error);
 657
 658         return error;
 659 }
 660
 661 #endif
 662
 663 static const struct inode_operations yaffs_dir_inode_operations = {
 664         .create = yaffs_create,
 665         .lookup = yaffs_lookup,
 666         .link = yaffs_link,
 667         .unlink = yaffs_unlink,
 668         .symlink = yaffs_symlink,
 669         .mkdir = yaffs_mkdir,
 670         .rmdir = yaffs_unlink,
 671         .mknod = yaffs_mknod,
 672         .rename = yaffs_rename,
 673         .setattr = yaffs_setattr,
 674 #ifdef CONFIG_YAFFS_XATTR
 675         .setxattr = yaffs_setxattr,
 676         .getxattr = yaffs_getxattr,
 677         .listxattr = yaffs_listxattr,
 678         .removexattr = yaffs_removexattr,
 679 #endif
 680 };
 681 /*-----------------------------------------------------------------*/
 682 /* Directory search context allows us to unlock access to yaffs during
 683  * filldir without causing problems with the directory being modified.
 684  * This is similar to the tried and tested mechanism used in yaffs direct.
 685  *
 686  * A search context iterates along a doubly linked list of siblings in the
 687  * directory. If the iterating object is deleted then this would corrupt
 688  * the list iteration, likely causing a crash. The search context avoids
 689  * this by using the remove_obj_fn to move the search context to the
 690  * next object before the object is deleted.
 691  *
 692  * Many readdirs (and thus seach conexts) may be alive simulateously so
 693  * each struct yaffs_dev has a list of these.
 694  *
 695  * A seach context lives for the duration of a readdir.
 696  *
 697  * All these functions must be called while yaffs is locked.
 698  */
 699
 700 struct yaffs_search_context {
 701         struct yaffs_dev *dev;
 702         struct yaffs_obj *dir_obj;
 703         struct yaffs_obj *next_return;
 704         struct list_head others;
 705 };
 706
 707 /*
 708  * yaffs_new_search() creates a new search context, initialises it and
 709  * adds it to the device's search context list.
 710  *
 711  * Called at start of readdir.
 712  */
 713 static struct yaffs_search_context *yaffs_new_search(struct yaffs_obj *dir)
 714 {
 715         struct yaffs_dev *dev = dir->my_dev;
 716         struct yaffs_search_context *sc =
 717             kmalloc(sizeof(struct yaffs_search_context), GFP_NOFS);
 718         if (sc) {
 719                 sc->dir_obj = dir;
 720                 sc->dev = dev;
 721                 if (list_empty(&sc->dir_obj->variant.dir_variant.children))
 722                         sc->next_return = NULL;
 723                 else
 724                         sc->next_return =
 725                             list_entry(dir->variant.dir_variant.children.next,
 726                                        struct yaffs_obj, siblings);
 727                 INIT_LIST_HEAD(&sc->others);
 728                 list_add(&sc->others, &(yaffs_dev_to_lc(dev)->search_contexts));
 729         }
 730         return sc;
 731 }
 732
 733 /*
 734  * yaffs_search_end() disposes of a search context and cleans up.
 735  */
 736 static void yaffs_search_end(struct yaffs_search_context *sc)
 737 {
 738         if (sc) {
 739                 list_del(&sc->others);
 740                 kfree(sc);
 741         }
 742 }
 743
 744 /*
 745  * yaffs_search_advance() moves a search context to the next object.
 746  * Called when the search iterates or when an object removal causes
 747  * the search context to be moved to the next object.
 748  */
 749 static void yaffs_search_advance(struct yaffs_search_context *sc)
 750 {
 751         if (!sc)
 752                 return;
 753
 754         if (sc->next_return == NULL ||
 755             list_empty(&sc->dir_obj->variant.dir_variant.children))
 756                 sc->next_return = NULL;
 757         else {
 758                 struct list_head *next = sc->next_return->siblings.next;
 759
 760                 if (next == &sc->dir_obj->variant.dir_variant.children)
 761                         sc->next_return = NULL; /* end of list */
 762                 else
 763                         sc->next_return =
 764                             list_entry(next, struct yaffs_obj, siblings);
 765         }
 766 }
 767
 768 /*
 769  * yaffs_remove_obj_callback() is called when an object is unlinked.
 770  * We check open search contexts and advance any which are currently
 771  * on the object being iterated.
 772  */
 773 static void yaffs_remove_obj_callback(struct yaffs_obj *obj)
 774 {
 775
 776         struct list_head *i;
 777         struct yaffs_search_context *sc;
 778         struct list_head *search_contexts =
 779             &(yaffs_dev_to_lc(obj->my_dev)->search_contexts);
 780
 781         /* Iterate through the directory search contexts.
 782          * If any are currently on the object being removed, then advance
 783          * the search context to the next object to prevent a hanging pointer.
 784          */
 785         list_for_each(i, search_contexts) {
 786                 if (i) {
 787                         sc = list_entry(i, struct yaffs_search_context, others);
 788                         if (sc->next_return == obj)
 789                                 yaffs_search_advance(sc);
 790                 }
 791         }
 792
 793 }
 794
 795 static int yaffs_readdir(struct file *f, void *dirent, filldir_t filldir)
 796 {
 797         struct yaffs_obj *obj;
 798         struct yaffs_dev *dev;
 799         struct yaffs_search_context *sc;
 800         struct inode *inode = f->f_dentry->d_inode;
 801         unsigned long offset, curoffs;
 802         struct yaffs_obj *l;
 803         int ret_val = 0;
 804
 805         char name[YAFFS_MAX_NAME_LENGTH + 1];
 806
 807         obj = yaffs_dentry_to_obj(f->f_dentry);
 808         dev = obj->my_dev;
 809
 810         yaffs_gross_lock(dev);
 811
 812         yaffs_dev_to_lc(dev)->readdir_process = current;
 813
 814         offset = f->f_pos;
 815
 816         sc = yaffs_new_search(obj);
 817         if (!sc) {
 818                 ret_val = -ENOMEM;
 819                 goto out;
 820         }
 821
 822         yaffs_trace(YAFFS_TRACE_OS,
 823                 "yaffs_readdir: starting at %d", (int)offset);
 824
 825         if (offset == 0) {
 826                 yaffs_trace(YAFFS_TRACE_OS,
 827                         "yaffs_readdir: entry . ino %d",
 828                         (int)inode->i_ino);
 829                 yaffs_gross_unlock(dev);
 830                 if (filldir(dirent, ".", 1, offset, inode->i_ino, DT_DIR) < 0) {
 831                         yaffs_gross_lock(dev);
 832                         goto out;
 833                 }
 834                 yaffs_gross_lock(dev);
 835                 offset++;
 836                 f->f_pos++;
 837         }
 838         if (offset == 1) {
 839                 yaffs_trace(YAFFS_TRACE_OS,
 840                         "yaffs_readdir: entry .. ino %d",
 841                         (int)f->f_dentry->d_parent->d_inode->i_ino);
 842                 yaffs_gross_unlock(dev);
 843                 if (filldir(dirent, "..", 2, offset,
 844                             f->f_dentry->d_parent->d_inode->i_ino,
 845                             DT_DIR) < 0) {
 846                         yaffs_gross_lock(dev);
 847                         goto out;
 848                 }
 849                 yaffs_gross_lock(dev);
 850                 offset++;
 851                 f->f_pos++;
 852         }
 853
 854         curoffs = 1;
 855
 856         /* If the directory has changed since the open or last call to
 857            readdir, rewind to after the 2 canned entries. */
 858         if (f->f_version != inode->i_version) {
 859                 offset = 2;
 860                 f->f_pos = offset;
 861                 f->f_version = inode->i_version;
 862         }
 863
 864         while (sc->next_return) {
 865                 curoffs++;
 866                 l = sc->next_return;
 867                 if (curoffs >= offset) {
 868                         int this_inode = yaffs_get_obj_inode(l);
 869                         int this_type = yaffs_get_obj_type(l);
 870
 871                         yaffs_get_obj_name(l, name, YAFFS_MAX_NAME_LENGTH + 1);
 872                         yaffs_trace(YAFFS_TRACE_OS,
 873                                 "yaffs_readdir: %s inode %d",
 874                                 name, yaffs_get_obj_inode(l));
 875
 876                         yaffs_gross_unlock(dev);
 877
 878                         if (filldir(dirent,
 879                                     name,
 880                                     strlen(name),
 881                                     offset, this_inode, this_type) < 0) {
 882                                 yaffs_gross_lock(dev);
 883                                 goto out;
 884                         }
 885
 886                         yaffs_gross_lock(dev);
 887
 888                         offset++;
 889                         f->f_pos++;
 890                 }
 891                 yaffs_search_advance(sc);
 892         }
 893
 894 out:
 895         yaffs_search_end(sc);
 896         yaffs_dev_to_lc(dev)->readdir_process = NULL;
 897         yaffs_gross_unlock(dev);
 898
 899         return ret_val;
 900 }
 901
 902 static const struct file_operations yaffs_dir_operations = {
 903         .read = generic_read_dir,
 904         .readdir = yaffs_readdir,
 905         .fsync = yaffs_sync_object,
 906         .llseek = generic_file_llseek,
 907 };
 908
 909
 910
 911 static int yaffs_file_flush(struct file *file, fl_owner_t id)
 912 {
 913         struct yaffs_obj *obj = yaffs_dentry_to_obj(file->f_dentry);
 914
 915         struct yaffs_dev *dev = obj->my_dev;
 916
 917         yaffs_trace(YAFFS_TRACE_OS,
 918                 "yaffs_file_flush object %d (%s)",
 919                 obj->obj_id, obj->dirty ? "dirty" : "clean");
 920
 921         yaffs_gross_lock(dev);
 922
 923         yaffs_flush_file(obj, 1, 0);
 924
 925         yaffs_gross_unlock(dev);
 926
 927         return 0;
 928 }
 929
 930 static const struct file_operations yaffs_file_operations = {
 931         .read = do_sync_read,
 932         .write = do_sync_write,
 933         .aio_read = generic_file_aio_read,
 934         .aio_write = generic_file_aio_write,
 935         .mmap = generic_file_mmap,
 936         .flush = yaffs_file_flush,
 937         .fsync = yaffs_sync_object,
 938         .splice_read = generic_file_splice_read,
 939         .splice_write = generic_file_splice_write,
 940         .llseek = generic_file_llseek,
 941 };
 942
 943
 944 /* ExportFS support */
 945 static struct inode *yaffs2_nfs_get_inode(struct super_block *sb, uint64_t ino,
 946                                           uint32_t generation)
 947 {
 948         return yaffs_iget(sb, ino);
 949 }
 950
 951 static struct dentry *yaffs2_fh_to_dentry(struct super_block *sb,
 952                                           struct fid *fid, int fh_len,
 953                                           int fh_type)
 954 {
 955         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
 956                                     yaffs2_nfs_get_inode);
 957 }
 958
 959 static struct dentry *yaffs2_fh_to_parent(struct super_block *sb,
 960                                           struct fid *fid, int fh_len,
 961                                           int fh_type)
 962 {
 963         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
 964                                     yaffs2_nfs_get_inode);
 965 }
 966
 967 struct dentry *yaffs2_get_parent(struct dentry *dentry)
 968 {
 969
 970         struct super_block *sb = dentry->d_inode->i_sb;
 971         struct dentry *parent = ERR_PTR(-ENOENT);
 972         struct inode *inode;
 973         unsigned long parent_ino;
 974         struct yaffs_obj *d_obj;
 975         struct yaffs_obj *parent_obj;
 976
 977         d_obj = yaffs_inode_to_obj(dentry->d_inode);
 978
 979         if (d_obj) {
 980                 parent_obj = d_obj->parent;
 981                 if (parent_obj) {
 982                         parent_ino = yaffs_get_obj_inode(parent_obj);
 983                         inode = yaffs_iget(sb, parent_ino);
 984
 985                         if (IS_ERR(inode)) {
 986                                 parent = ERR_CAST(inode);
 987                         } else {
 988                                 parent = d_obtain_alias(inode);
 989                                 if (!IS_ERR(parent)) {
 990                                         parent = ERR_PTR(-ENOMEM);
 991                                         iput(inode);
 992                                 }
 993                         }
 994                 }
 995         }
 996
 997         return parent;
 998 }
 999
1000 /* Just declare a zero structure as a NULL value implies
1001  * using the default functions of exportfs.
1002  */
1003
1004 static struct export_operations yaffs_export_ops = {
1005         .fh_to_dentry = yaffs2_fh_to_dentry,
1006         .fh_to_parent = yaffs2_fh_to_parent,
1007         .get_parent = yaffs2_get_parent,
1008 };
1009
1010
1011 /*-----------------------------------------------------------------*/
1012
1013 static int yaffs_readlink(struct dentry *dentry, char __user * buffer,
1014                           int buflen)
1015 {
1016         unsigned char *alias;
1017         int ret;
1018
1019         struct yaffs_dev *dev = yaffs_dentry_to_obj(dentry)->my_dev;
1020
1021         yaffs_gross_lock(dev);
1022
1023         alias = yaffs_get_symlink_alias(yaffs_dentry_to_obj(dentry));
1024
1025         yaffs_gross_unlock(dev);
1026
1027         if (!alias)
1028                 return -ENOMEM;
1029
1030         ret = vfs_readlink(dentry, buffer, buflen, alias);
1031         kfree(alias);
1032         return ret;
1033 }
1034
1035 static void *yaffs_follow_link(struct dentry *dentry, struct nameidata *nd)
1036 {
1037         unsigned char *alias;
1038         void *ret;
1039         struct yaffs_dev *dev = yaffs_dentry_to_obj(dentry)->my_dev;
1040
1041         yaffs_gross_lock(dev);
1042
1043         alias = yaffs_get_symlink_alias(yaffs_dentry_to_obj(dentry));
1044         yaffs_gross_unlock(dev);
1045
1046         if (!alias) {
1047                 ret = ERR_PTR(-ENOMEM);
1048                 goto out;
1049         }
1050
1051         nd_set_link(nd, alias);
1052         ret = (void *)alias;
1053 out:
1054         return ret;
1055 }
1056
1057 void yaffs_put_link(struct dentry *dentry, struct nameidata *nd, void *alias)
1058 {
1059         kfree(alias);
1060 }
1061
1062
1063 static void yaffs_unstitch_obj(struct inode *inode, struct yaffs_obj *obj)
1064 {
1065         /* Clear the association between the inode and
1066          * the struct yaffs_obj.
1067          */
1068         obj->my_inode = NULL;
1069         yaffs_inode_to_obj_lv(inode) = NULL;
1070
1071         /* If the object freeing was deferred, then the real
1072          * free happens now.
1073          * This should fix the inode inconsistency problem.
1074          */
1075         yaffs_handle_defered_free(obj);
1076 }
1077
1078 /* yaffs_evict_inode combines into one operation what was previously done in
1079  * yaffs_clear_inode() and yaffs_delete_inode()
1080  *
1081  */
1082 static void yaffs_evict_inode(struct inode *inode)
1083 {
1084         struct yaffs_obj *obj;
1085         struct yaffs_dev *dev;
1086         int deleteme = 0;
1087
1088         obj = yaffs_inode_to_obj(inode);
1089
1090         yaffs_trace(YAFFS_TRACE_OS,
1091                 "yaffs_evict_inode: ino %d, count %d %s",
1092                 (int)inode->i_ino,
1093                 atomic_read(&inode->i_count),
1094                 obj ? "object exists" : "null object");
1095
1096         if (!inode->i_nlink && !is_bad_inode(inode))
1097                 deleteme = 1;
1098         truncate_inode_pages(&inode->i_data, 0);
1099         end_writeback(inode);
1100
1101         if (deleteme && obj) {
1102                 dev = obj->my_dev;
1103                 yaffs_gross_lock(dev);
1104                 yaffs_del_obj(obj);
1105                 yaffs_gross_unlock(dev);
1106         }
1107         if (obj) {
1108                 dev = obj->my_dev;
1109                 yaffs_gross_lock(dev);
1110                 yaffs_unstitch_obj(inode, obj);
1111                 yaffs_gross_unlock(dev);
1112         }
1113
1114 }
1115
1116 static void yaffs_touch_super(struct yaffs_dev *dev)
1117 {
1118         struct super_block *sb = yaffs_dev_to_lc(dev)->super;
1119
1120         yaffs_trace(YAFFS_TRACE_OS, "yaffs_touch_super() sb = %p", sb);
1121         if (sb)
1122                 sb->s_dirt = 1;
1123 }
1124
1125 static int yaffs_readpage_nolock(struct file *f, struct page *pg)
1126 {
1127         /* Lifted from jffs2 */
1128
1129         struct yaffs_obj *obj;
1130         unsigned char *pg_buf;
1131         int ret;
1132
1133         struct yaffs_dev *dev;
1134
1135         yaffs_trace(YAFFS_TRACE_OS,
1136                 "yaffs_readpage_nolock at %08x, size %08x",
1137                 (unsigned)(pg->index << PAGE_CACHE_SHIFT),
1138                 (unsigned)PAGE_CACHE_SIZE);
1139
1140         obj = yaffs_dentry_to_obj(f->f_dentry);
1141
1142         dev = obj->my_dev;
1143
1144         BUG_ON(!PageLocked(pg));
1145
1146         pg_buf = kmap(pg);
1147         /* FIXME: Can kmap fail? */
1148
1149         yaffs_gross_lock(dev);
1150
1151         ret = yaffs_file_rd(obj, pg_buf,
1152                             pg->index << PAGE_CACHE_SHIFT, PAGE_CACHE_SIZE);
1153
1154         yaffs_gross_unlock(dev);
1155
1156         if (ret >= 0)
1157                 ret = 0;
1158
1159         if (ret) {
1160                 ClearPageUptodate(pg);
1161                 SetPageError(pg);
1162         } else {
1163                 SetPageUptodate(pg);
1164                 ClearPageError(pg);
1165         }
1166
1167         flush_dcache_page(pg);
1168         kunmap(pg);
1169
1170         yaffs_trace(YAFFS_TRACE_OS, "yaffs_readpage_nolock done");
1171         return ret;
1172 }
1173
1174 static int yaffs_readpage_unlock(struct file *f, struct page *pg)
1175 {
1176         int ret = yaffs_readpage_nolock(f, pg);
1177         unlock_page(pg);
1178         return ret;
1179 }
1180
1181 static int yaffs_readpage(struct file *f, struct page *pg)
1182 {
1183         int ret;
1184
1185         yaffs_trace(YAFFS_TRACE_OS, "yaffs_readpage");
1186         ret = yaffs_readpage_unlock(f, pg);
1187         yaffs_trace(YAFFS_TRACE_OS, "yaffs_readpage done");
1188         return ret;
1189 }
1190
1191 /* writepage inspired by/stolen from smbfs */
1192
1193 static int yaffs_writepage(struct page *page, struct writeback_control *wbc)
1194 {
1195         struct yaffs_dev *dev;
1196         struct address_space *mapping = page->mapping;
1197         struct inode *inode;
1198         unsigned long end_index;
1199         char *buffer;
1200         struct yaffs_obj *obj;
1201         int n_written = 0;
1202         unsigned n_bytes;
1203         loff_t i_size;
1204
1205         if (!mapping)
1206                 BUG();
1207         inode = mapping->host;
1208         if (!inode)
1209                 BUG();
1210         i_size = i_size_read(inode);
1211
1212         end_index = i_size >> PAGE_CACHE_SHIFT;
1213
1214         if (page->index < end_index)
1215                 n_bytes = PAGE_CACHE_SIZE;
1216         else {
1217                 n_bytes = i_size & (PAGE_CACHE_SIZE - 1);
1218
1219                 if (page->index > end_index || !n_bytes) {
1220                         yaffs_trace(YAFFS_TRACE_OS,
1221                                 "yaffs_writepage at %08x, inode size = %08x!!!",
1222                                 (unsigned)(page->index << PAGE_CACHE_SHIFT),
1223                                 (unsigned)inode->i_size);
1224                         yaffs_trace(YAFFS_TRACE_OS,
1225                           "                -> don't care!!");
1226
1227                         zero_user_segment(page, 0, PAGE_CACHE_SIZE);
1228                         set_page_writeback(page);
1229                         unlock_page(page);
1230                         end_page_writeback(page);
1231                         return 0;
1232                 }
1233         }
1234
1235         if (n_bytes != PAGE_CACHE_SIZE)
1236                 zero_user_segment(page, n_bytes, PAGE_CACHE_SIZE);
1237
1238         get_page(page);
1239
1240         buffer = kmap(page);
1241
1242         obj = yaffs_inode_to_obj(inode);
1243         dev = obj->my_dev;
1244         yaffs_gross_lock(dev);
1245
1246         yaffs_trace(YAFFS_TRACE_OS,
1247                 "yaffs_writepage at %08x, size %08x",
1248                 (unsigned)(page->index << PAGE_CACHE_SHIFT), n_bytes);
1249         yaffs_trace(YAFFS_TRACE_OS,
1250                 "writepag0: obj = %05x, ino = %05x",
1251                 (int)obj->variant.file_variant.file_size, (int)inode->i_size);
1252
1253         n_written = yaffs_wr_file(obj, buffer,
1254                                   page->index << PAGE_CACHE_SHIFT, n_bytes, 0);
1255
1256         yaffs_touch_super(dev);
1257
1258         yaffs_trace(YAFFS_TRACE_OS,
1259                 "writepag1: obj = %05x, ino = %05x",
1260                 (int)obj->variant.file_variant.file_size, (int)inode->i_size);
1261
1262         yaffs_gross_unlock(dev);
1263
1264         kunmap(page);
1265         set_page_writeback(page);
1266         unlock_page(page);
1267         end_page_writeback(page);
1268         put_page(page);
1269
1270         return (n_written == n_bytes) ? 0 : -ENOSPC;
1271 }
1272
1273 /* Space holding and freeing is done to ensure we have space available for
1274  * write_begin/end.
1275  * For now we just assume few parallel writes and check against a small
1276  * number.
1277  * Todo: need to do this with a counter to handle parallel reads better.
1278  */
1279
1280 static ssize_t yaffs_hold_space(struct file *f)
1281 {
1282         struct yaffs_obj *obj;
1283         struct yaffs_dev *dev;
1284
1285         int n_free_chunks;
1286
1287         obj = yaffs_dentry_to_obj(f->f_dentry);
1288
1289         dev = obj->my_dev;
1290
1291         yaffs_gross_lock(dev);
1292
1293         n_free_chunks = yaffs_get_n_free_chunks(dev);
1294
1295         yaffs_gross_unlock(dev);
1296
1297         return (n_free_chunks > 20) ? 1 : 0;
1298 }
1299
1300 static void yaffs_release_space(struct file *f)
1301 {
1302         struct yaffs_obj *obj;
1303         struct yaffs_dev *dev;
1304
1305         obj = yaffs_dentry_to_obj(f->f_dentry);
1306
1307         dev = obj->my_dev;
1308
1309         yaffs_gross_lock(dev);
1310
1311         yaffs_gross_unlock(dev);
1312 }
1313
1314 static int yaffs_write_begin(struct file *filp, struct address_space *mapping,
1315                              loff_t pos, unsigned len, unsigned flags,
1316                              struct page **pagep, void **fsdata)
1317 {
1318         struct page *pg = NULL;
1319         pgoff_t index = pos >> PAGE_CACHE_SHIFT;
1320
1321         int ret = 0;
1322         int space_held = 0;
1323
1324         /* Get a page */
1325         pg = grab_cache_page_write_begin(mapping, index, flags);
1326
1327         *pagep = pg;
1328         if (!pg) {
1329                 ret = -ENOMEM;
1330                 goto out;
1331         }
1332         yaffs_trace(YAFFS_TRACE_OS,
1333                 "start yaffs_write_begin index %d(%x) uptodate %d",
1334                 (int)index, (int)index, PageUptodate(pg) ? 1 : 0);
1335
1336         /* Get fs space */
1337         space_held = yaffs_hold_space(filp);
1338
1339         if (!space_held) {
1340                 ret = -ENOSPC;
1341                 goto out;
1342         }
1343
1344         /* Update page if required */
1345
1346         if (!PageUptodate(pg))
1347                 ret = yaffs_readpage_nolock(filp, pg);
1348
1349         if (ret)
1350                 goto out;
1351
1352         /* Happy path return */
1353         yaffs_trace(YAFFS_TRACE_OS, "end yaffs_write_begin - ok");
1354
1355         return 0;
1356
1357 out:
1358         yaffs_trace(YAFFS_TRACE_OS,
1359                 "end yaffs_write_begin fail returning %d", ret);
1360         if (space_held)
1361                 yaffs_release_space(filp);
1362         if (pg) {
1363                 unlock_page(pg);
1364                 page_cache_release(pg);
1365         }
1366         return ret;
1367 }
1368
1369 static ssize_t yaffs_file_write(struct file *f, const char *buf, size_t n,
1370                                 loff_t * pos)
1371 {
1372         struct yaffs_obj *obj;
1373         int n_written, ipos;
1374         struct inode *inode;
1375         struct yaffs_dev *dev;
1376
1377         obj = yaffs_dentry_to_obj(f->f_dentry);
1378
1379         dev = obj->my_dev;
1380
1381         yaffs_gross_lock(dev);
1382
1383         inode = f->f_dentry->d_inode;
1384
1385         if (!S_ISBLK(inode->i_mode) && f->f_flags & O_APPEND)
1386                 ipos = inode->i_size;
1387         else
1388                 ipos = *pos;
1389
1390         if (!obj)
1391                 yaffs_trace(YAFFS_TRACE_OS,
1392                         "yaffs_file_write: hey obj is null!");
1393         else
1394                 yaffs_trace(YAFFS_TRACE_OS,
1395                         "yaffs_file_write about to write writing %u(%x) bytes to object %d at %d(%x)",
1396                         (unsigned)n, (unsigned)n, obj->obj_id, ipos, ipos);
1397
1398         n_written = yaffs_wr_file(obj, buf, ipos, n, 0);
1399
1400         yaffs_touch_super(dev);
1401
1402         yaffs_trace(YAFFS_TRACE_OS,
1403                 "yaffs_file_write: %d(%x) bytes written",
1404                 (unsigned)n, (unsigned)n);
1405
1406         if (n_written > 0) {
1407                 ipos += n_written;
1408                 *pos = ipos;
1409                 if (ipos > inode->i_size) {
1410                         inode->i_size = ipos;
1411                         inode->i_blocks = (ipos + 511) >> 9;
1412
1413                         yaffs_trace(YAFFS_TRACE_OS,
1414                                 "yaffs_file_write size updated to %d bytes, %d blocks",
1415                                 ipos, (int)(inode->i_blocks));
1416                 }
1417
1418         }
1419         yaffs_gross_unlock(dev);
1420         return (n_written == 0) && (n > 0) ? -ENOSPC : n_written;
1421 }
1422
1423 static int yaffs_write_end(struct file *filp, struct address_space *mapping,
1424                            loff_t pos, unsigned len, unsigned copied,
1425                            struct page *pg, void *fsdadata)
1426 {
1427         int ret = 0;
1428         void *addr, *kva;
1429         uint32_t offset_into_page = pos & (PAGE_CACHE_SIZE - 1);
1430
1431         kva = kmap(pg);
1432         addr = kva + offset_into_page;
1433
1434         yaffs_trace(YAFFS_TRACE_OS,
1435                 "yaffs_write_end addr %p pos %x n_bytes %d",
1436                 addr, (unsigned)pos, copied);
1437
1438         ret = yaffs_file_write(filp, addr, copied, &pos);
1439
1440         if (ret != copied) {
1441                 yaffs_trace(YAFFS_TRACE_OS,
1442                         "yaffs_write_end not same size ret %d  copied %d",
1443                         ret, copied);
1444                 SetPageError(pg);
1445         }
1446
1447         kunmap(pg);
1448
1449         yaffs_release_space(filp);
1450         unlock_page(pg);
1451         page_cache_release(pg);
1452         return ret;
1453 }
1454
1455 static int yaffs_statfs(struct dentry *dentry, struct kstatfs *buf)
1456 {
1457         struct yaffs_dev *dev = yaffs_dentry_to_obj(dentry)->my_dev;
1458         struct super_block *sb = dentry->d_sb;
1459
1460         yaffs_trace(YAFFS_TRACE_OS, "yaffs_statfs");
1461
1462         yaffs_gross_lock(dev);
1463
1464         buf->f_type = YAFFS_MAGIC;
1465         buf->f_bsize = sb->s_blocksize;
1466         buf->f_namelen = 255;
1467
1468         if (dev->data_bytes_per_chunk & (dev->data_bytes_per_chunk - 1)) {
1469                 /* Do this if chunk size is not a power of 2 */
1470
1471                 uint64_t bytes_in_dev;
1472                 uint64_t bytes_free;
1473
1474                 bytes_in_dev =
1475                     ((uint64_t)
1476                      ((dev->param.end_block - dev->param.start_block +
1477                        1))) * ((uint64_t) (dev->param.chunks_per_block *
1478                                            dev->data_bytes_per_chunk));
1479
1480                 do_div(bytes_in_dev, sb->s_blocksize);  /* bytes_in_dev becomes the number of blocks */
1481                 buf->f_blocks = bytes_in_dev;
1482
1483                 bytes_free = ((uint64_t) (yaffs_get_n_free_chunks(dev))) *
1484                     ((uint64_t) (dev->data_bytes_per_chunk));
1485
1486                 do_div(bytes_free, sb->s_blocksize);
1487
1488                 buf->f_bfree = bytes_free;
1489
1490         } else if (sb->s_blocksize > dev->data_bytes_per_chunk) {
1491
1492                 buf->f_blocks =
1493                     (dev->param.end_block - dev->param.start_block + 1) *
1494                     dev->param.chunks_per_block /
1495                     (sb->s_blocksize / dev->data_bytes_per_chunk);
1496                 buf->f_bfree =
1497                     yaffs_get_n_free_chunks(dev) /
1498                     (sb->s_blocksize / dev->data_bytes_per_chunk);
1499         } else {
1500                 buf->f_blocks =
1501                     (dev->param.end_block - dev->param.start_block + 1) *
1502                     dev->param.chunks_per_block *
1503                     (dev->data_bytes_per_chunk / sb->s_blocksize);
1504
1505                 buf->f_bfree =
1506                     yaffs_get_n_free_chunks(dev) *
1507                     (dev->data_bytes_per_chunk / sb->s_blocksize);
1508         }
1509
1510         buf->f_files = 0;
1511         buf->f_ffree = 0;
1512         buf->f_bavail = buf->f_bfree;
1513
1514         yaffs_gross_unlock(dev);
1515         return 0;
1516 }
1517
1518 static void yaffs_flush_inodes(struct super_block *sb)
1519 {
1520         struct inode *iptr;
1521         struct yaffs_obj *obj;
1522
1523         list_for_each_entry(iptr, &sb->s_inodes, i_sb_list) {
1524                 obj = yaffs_inode_to_obj(iptr);
1525                 if (obj) {
1526                         yaffs_trace(YAFFS_TRACE_OS,
1527                                 "flushing obj %d", obj->obj_id);
1528                         yaffs_flush_file(obj, 1, 0);
1529                 }
1530         }
1531 }
1532
1533 static void yaffs_flush_super(struct super_block *sb, int do_checkpoint)
1534 {
1535         struct yaffs_dev *dev = yaffs_super_to_dev(sb);
1536         if (!dev)
1537                 return;
1538
1539         yaffs_flush_inodes(sb);
1540         yaffs_update_dirty_dirs(dev);
1541         yaffs_flush_whole_cache(dev);
1542         if (do_checkpoint)
1543                 yaffs_checkpoint_save(dev);
1544 }
1545
1546 static unsigned yaffs_bg_gc_urgency(struct yaffs_dev *dev)
1547 {
1548         unsigned erased_chunks =
1549             dev->n_erased_blocks * dev->param.chunks_per_block;
1550         struct yaffs_linux_context *context = yaffs_dev_to_lc(dev);
1551         unsigned scattered = 0; /* Free chunks not in an erased block */
1552
1553         if (erased_chunks < dev->n_free_chunks)
1554                 scattered = (dev->n_free_chunks - erased_chunks);
1555
1556         if (!context->bg_running)
1557                 return 0;
1558         else if (scattered < (dev->param.chunks_per_block * 2))
1559                 return 0;
1560         else if (erased_chunks > dev->n_free_chunks / 2)
1561                 return 0;
1562         else if (erased_chunks > dev->n_free_chunks / 4)
1563                 return 1;
1564         else
1565                 return 2;
1566 }
1567
1568 static int yaffs_do_sync_fs(struct super_block *sb, int request_checkpoint)
1569 {
1570
1571         struct yaffs_dev *dev = yaffs_super_to_dev(sb);
1572         unsigned int oneshot_checkpoint = (yaffs_auto_checkpoint & 4);
1573         unsigned gc_urgent = yaffs_bg_gc_urgency(dev);
1574         int do_checkpoint;
1575
1576         yaffs_trace(YAFFS_TRACE_OS | YAFFS_TRACE_SYNC | YAFFS_TRACE_BACKGROUND,
1577                 "yaffs_do_sync_fs: gc-urgency %d %s %s%s",
1578                 gc_urgent,
1579                 sb->s_dirt ? "dirty" : "clean",
1580                 request_checkpoint ? "checkpoint requested" : "no checkpoint",
1581                 oneshot_checkpoint ? " one-shot" : "");
1582
1583         yaffs_gross_lock(dev);
1584         do_checkpoint = ((request_checkpoint && !gc_urgent) ||
1585                          oneshot_checkpoint) && !dev->is_checkpointed;
1586
1587         if (sb->s_dirt || do_checkpoint) {
1588                 yaffs_flush_super(sb, !dev->is_checkpointed && do_checkpoint);
1589                 sb->s_dirt = 0;
1590                 if (oneshot_checkpoint)
1591                         yaffs_auto_checkpoint &= ~4;
1592         }
1593         yaffs_gross_unlock(dev);
1594
1595         return 0;
1596 }
1597
1598 /*
1599  * yaffs background thread functions .
1600  * yaffs_bg_thread_fn() the thread function
1601  * yaffs_bg_start() launches the background thread.
1602  * yaffs_bg_stop() cleans up the background thread.
1603  *
1604  * NB:
1605  * The thread should only run after the yaffs is initialised
1606  * The thread should be stopped before yaffs is unmounted.
1607  * The thread should not do any writing while the fs is in read only.
1608  */
1609
1610 void yaffs_background_waker(unsigned long data)
1611 {
1612         wake_up_process((struct task_struct *)data);
1613 }
1614
1615 static int yaffs_bg_thread_fn(void *data)
1616 {
1617         struct yaffs_dev *dev = (struct yaffs_dev *)data;
1618         struct yaffs_linux_context *context = yaffs_dev_to_lc(dev);
1619         unsigned long now = jiffies;
1620         unsigned long next_dir_update = now;
1621         unsigned long next_gc = now;
1622         unsigned long expires;
1623         unsigned int urgency;
1624
1625         int gc_result;
1626         struct timer_list timer;
1627
1628         yaffs_trace(YAFFS_TRACE_BACKGROUND,
1629                 "yaffs_background starting for dev %p", (void *)dev);
1630
1631         set_freezable();
1632         while (context->bg_running) {
1633                 yaffs_trace(YAFFS_TRACE_BACKGROUND, "yaffs_background");
1634
1635                 if (kthread_should_stop())
1636                         break;
1637
1638                 if (try_to_freeze())
1639                         continue;
1640
1641                 yaffs_gross_lock(dev);
1642
1643                 now = jiffies;
1644
1645                 if (time_after(now, next_dir_update) && yaffs_bg_enable) {
1646                         yaffs_update_dirty_dirs(dev);
1647                         next_dir_update = now + HZ;
1648                 }
1649
1650                 if (time_after(now, next_gc) && yaffs_bg_enable) {
1651                         if (!dev->is_checkpointed) {
1652                                 urgency = yaffs_bg_gc_urgency(dev);
1653                                 gc_result = yaffs_bg_gc(dev, urgency);
1654                                 if (urgency > 1)
1655                                         next_gc = now + HZ / 20 + 1;
1656                                 else if (urgency > 0)
1657                                         next_gc = now + HZ / 10 + 1;
1658                                 else
1659                                         next_gc = now + HZ * 2;
1660                         } else  {
1661                                 /*
1662                                  * gc not running so set to next_dir_update
1663                                  * to cut down on wake ups
1664                                  */
1665                                 next_gc = next_dir_update;
1666                         }
1667                 }
1668                 yaffs_gross_unlock(dev);
1669                 expires = next_dir_update;
1670                 if (time_before(next_gc, expires))
1671                         expires = next_gc;
1672                 if (time_before(expires, now))
1673                         expires = now + HZ;
1674
1675                 Y_INIT_TIMER(&timer);
1676                 timer.expires = expires + 1;
1677                 timer.data = (unsigned long)current;
1678                 timer.function = yaffs_background_waker;
1679
1680                 set_current_state(TASK_INTERRUPTIBLE);
1681                 add_timer(&timer);
1682                 schedule();
1683                 del_timer_sync(&timer);
1684         }
1685
1686         return 0;
1687 }
1688
1689 static int yaffs_bg_start(struct yaffs_dev *dev)
1690 {
1691         int retval = 0;
1692         struct yaffs_linux_context *context = yaffs_dev_to_lc(dev);
1693
1694         if (dev->read_only)
1695                 return -1;
1696
1697         context->bg_running = 1;
1698
1699         context->bg_thread = kthread_run(yaffs_bg_thread_fn,
1700                                          (void *)dev, "yaffs-bg-%d",
1701                                          context->mount_id);
1702
1703         if (IS_ERR(context->bg_thread)) {
1704                 retval = PTR_ERR(context->bg_thread);
1705                 context->bg_thread = NULL;
1706                 context->bg_running = 0;
1707         }
1708         return retval;
1709 }
1710
1711 static void yaffs_bg_stop(struct yaffs_dev *dev)
1712 {
1713         struct yaffs_linux_context *ctxt = yaffs_dev_to_lc(dev);
1714
1715         ctxt->bg_running = 0;
1716
1717         if (ctxt->bg_thread) {
1718                 kthread_stop(ctxt->bg_thread);
1719                 ctxt->bg_thread = NULL;
1720         }
1721 }
1722
1723 static void yaffs_write_super(struct super_block *sb)
1724 {
1725         unsigned request_checkpoint = (yaffs_auto_checkpoint >= 2);
1726
1727         yaffs_trace(YAFFS_TRACE_OS | YAFFS_TRACE_SYNC | YAFFS_TRACE_BACKGROUND,
1728                 "yaffs_write_super%s",
1729                 request_checkpoint ? " checkpt" : "");
1730
1731         yaffs_do_sync_fs(sb, request_checkpoint);
1732
1733 }
1734
1735 static int yaffs_sync_fs(struct super_block *sb, int wait)
1736 {
1737         unsigned request_checkpoint = (yaffs_auto_checkpoint >= 1);
1738
1739         yaffs_trace(YAFFS_TRACE_OS | YAFFS_TRACE_SYNC,
1740                 "yaffs_sync_fs%s", request_checkpoint ? " checkpt" : "");
1741
1742         yaffs_do_sync_fs(sb, request_checkpoint);
1743
1744         return 0;
1745 }
1746
1747
1748 static LIST_HEAD(yaffs_context_list);
1749 struct mutex yaffs_context_lock;
1750
1751
1752
1753 struct yaffs_options {
1754         int inband_tags;
1755         int skip_checkpoint_read;
1756         int skip_checkpoint_write;
1757         int no_cache;
1758         int tags_ecc_on;
1759         int tags_ecc_overridden;
1760         int lazy_loading_enabled;
1761         int lazy_loading_overridden;
1762         int empty_lost_and_found;
1763         int empty_lost_and_found_overridden;
1764 };
1765
1766 #define MAX_OPT_LEN 30
1767 static int yaffs_parse_options(struct yaffs_options *options,
1768                                const char *options_str)
1769 {
1770         char cur_opt[MAX_OPT_LEN + 1];
1771         int p;
1772         int error = 0;
1773
1774         /* Parse through the options which is a comma seperated list */
1775
1776         while (options_str && *options_str && !error) {
1777                 memset(cur_opt, 0, MAX_OPT_LEN + 1);
1778                 p = 0;
1779
1780                 while (*options_str == ',')
1781                         options_str++;
1782
1783                 while (*options_str && *options_str != ',') {
1784                         if (p < MAX_OPT_LEN) {
1785                                 cur_opt[p] = *options_str;
1786                                 p++;
1787                         }
1788                         options_str++;
1789                 }
1790
1791                 if (!strcmp(cur_opt, "inband-tags")) {
1792                         options->inband_tags = 1;
1793                 } else if (!strcmp(cur_opt, "tags-ecc-off")) {
1794                         options->tags_ecc_on = 0;
1795                         options->tags_ecc_overridden = 1;
1796                 } else if (!strcmp(cur_opt, "tags-ecc-on")) {
1797                         options->tags_ecc_on = 1;
1798                         options->tags_ecc_overridden = 1;
1799                 } else if (!strcmp(cur_opt, "lazy-loading-off")) {
1800                         options->lazy_loading_enabled = 0;
1801                         options->lazy_loading_overridden = 1;
1802                 } else if (!strcmp(cur_opt, "lazy-loading-on")) {
1803                         options->lazy_loading_enabled = 1;
1804                         options->lazy_loading_overridden = 1;
1805                 } else if (!strcmp(cur_opt, "empty-lost-and-found-off")) {
1806                         options->empty_lost_and_found = 0;
1807                         options->empty_lost_and_found_overridden = 1;
1808                 } else if (!strcmp(cur_opt, "empty-lost-and-found-on")) {
1809                         options->empty_lost_and_found = 1;
1810                         options->empty_lost_and_found_overridden = 1;
1811                 } else if (!strcmp(cur_opt, "no-cache")) {
1812                         options->no_cache = 1;
1813                 } else if (!strcmp(cur_opt, "no-checkpoint-read")) {
1814                         options->skip_checkpoint_read = 1;
1815                 } else if (!strcmp(cur_opt, "no-checkpoint-write")) {
1816                         options->skip_checkpoint_write = 1;
1817                 } else if (!strcmp(cur_opt, "no-checkpoint")) {
1818                         options->skip_checkpoint_read = 1;
1819                         options->skip_checkpoint_write = 1;
1820                 } else {
1821                         printk(KERN_INFO "yaffs: Bad mount option \"%s\"\n",
1822                                cur_opt);
1823                         error = 1;
1824                 }
1825         }
1826
1827         return error;
1828 }
1829
1830 static struct address_space_operations yaffs_file_address_operations = {
1831         .readpage = yaffs_readpage,
1832         .writepage = yaffs_writepage,
1833         .write_begin = yaffs_write_begin,
1834         .write_end = yaffs_write_end,
1835 };
1836
1837
1838
1839 static const struct inode_operations yaffs_file_inode_operations = {
1840         .setattr = yaffs_setattr,
1841 #ifdef CONFIG_YAFFS_XATTR
1842         .setxattr = yaffs_setxattr,
1843         .getxattr = yaffs_getxattr,
1844         .listxattr = yaffs_listxattr,
1845         .removexattr = yaffs_removexattr,
1846 #endif
1847 };
1848
1849 static const struct inode_operations yaffs_symlink_inode_operations = {
1850         .readlink = yaffs_readlink,
1851         .follow_link = yaffs_follow_link,
1852         .put_link = yaffs_put_link,
1853         .setattr = yaffs_setattr,
1854 #ifdef CONFIG_YAFFS_XATTR
1855         .setxattr = yaffs_setxattr,
1856         .getxattr = yaffs_getxattr,
1857         .listxattr = yaffs_listxattr,
1858         .removexattr = yaffs_removexattr,
1859 #endif
1860 };
1861
1862 static void yaffs_fill_inode_from_obj(struct inode *inode,
1863                                       struct yaffs_obj *obj)
1864 {
1865         if (inode && obj) {
1866
1867                 /* Check mode against the variant type and attempt to repair if broken. */
1868                 u32 mode = obj->yst_mode;
1869                 switch (obj->variant_type) {
1870                 case YAFFS_OBJECT_TYPE_FILE:
1871                         if (!S_ISREG(mode)) {
1872                                 obj->yst_mode &= ~S_IFMT;
1873                                 obj->yst_mode |= S_IFREG;
1874                         }
1875
1876                         break;
1877                 case YAFFS_OBJECT_TYPE_SYMLINK:
1878                         if (!S_ISLNK(mode)) {
1879                                 obj->yst_mode &= ~S_IFMT;
1880                                 obj->yst_mode |= S_IFLNK;
1881                         }
1882
1883                         break;
1884                 case YAFFS_OBJECT_TYPE_DIRECTORY:
1885                         if (!S_ISDIR(mode)) {
1886                                 obj->yst_mode &= ~S_IFMT;
1887                                 obj->yst_mode |= S_IFDIR;
1888                         }
1889
1890                         break;
1891                 case YAFFS_OBJECT_TYPE_UNKNOWN:
1892                 case YAFFS_OBJECT_TYPE_HARDLINK:
1893                 case YAFFS_OBJECT_TYPE_SPECIAL:
1894                 default:
1895                         /* TODO? */
1896                         break;
1897                 }
1898
1899                 inode->i_flags |= S_NOATIME;
1900
1901                 inode->i_ino = obj->obj_id;
1902                 inode->i_mode = obj->yst_mode;
1903                 inode->i_uid = obj->yst_uid;
1904                 inode->i_gid = obj->yst_gid;
1905
1906                 inode->i_rdev = old_decode_dev(obj->yst_rdev);
1907
1908                 inode->i_atime.tv_sec = (time_t) (obj->yst_atime);
1909                 inode->i_atime.tv_nsec = 0;
1910                 inode->i_mtime.tv_sec = (time_t) obj->yst_mtime;
1911                 inode->i_mtime.tv_nsec = 0;
1912                 inode->i_ctime.tv_sec = (time_t) obj->yst_ctime;
1913                 inode->i_ctime.tv_nsec = 0;
1914                 inode->i_size = yaffs_get_obj_length(obj);
1915                 inode->i_blocks = (inode->i_size + 511) >> 9;
1916
1917                 inode->i_nlink = yaffs_get_obj_link_count(obj);
1918
1919                 yaffs_trace(YAFFS_TRACE_OS,
1920                         "yaffs_fill_inode mode %x uid %d gid %d size %d count %d",
1921                         inode->i_mode, inode->i_uid, inode->i_gid,
1922                         (int)inode->i_size, atomic_read(&inode->i_count));
1923
1924                 switch (obj->yst_mode & S_IFMT) {
1925                 default:        /* fifo, device or socket */
1926                         init_special_inode(inode, obj->yst_mode,
1927                                            old_decode_dev(obj->yst_rdev));
1928                         break;
1929                 case S_IFREG:   /* file */
1930                         inode->i_op = &yaffs_file_inode_operations;
1931                         inode->i_fop = &yaffs_file_operations;
1932                         inode->i_mapping->a_ops =
1933                             &yaffs_file_address_operations;
1934                         break;
1935                 case S_IFDIR:   /* directory */
1936                         inode->i_op = &yaffs_dir_inode_operations;
1937                         inode->i_fop = &yaffs_dir_operations;
1938                         break;
1939                 case S_IFLNK:   /* symlink */
1940                         inode->i_op = &yaffs_symlink_inode_operations;
1941                         break;
1942                 }
1943
1944                 yaffs_inode_to_obj_lv(inode) = obj;
1945
1946                 obj->my_inode = inode;
1947
1948         } else {
1949                 yaffs_trace(YAFFS_TRACE_OS,
1950                         "yaffs_fill_inode invalid parameters");
1951         }
1952 }
1953
1954 static void yaffs_put_super(struct super_block *sb)
1955 {
1956         struct yaffs_dev *dev = yaffs_super_to_dev(sb);
1957
1958         yaffs_trace(YAFFS_TRACE_OS, "yaffs_put_super");
1959
1960         yaffs_trace(YAFFS_TRACE_OS | YAFFS_TRACE_BACKGROUND,
1961                 "Shutting down yaffs background thread");
1962         yaffs_bg_stop(dev);
1963         yaffs_trace(YAFFS_TRACE_OS | YAFFS_TRACE_BACKGROUND,
1964                 "yaffs background thread shut down");
1965
1966         yaffs_gross_lock(dev);
1967
1968         yaffs_flush_super(sb, 1);
1969
1970         if (yaffs_dev_to_lc(dev)->put_super_fn)
1971                 yaffs_dev_to_lc(dev)->put_super_fn(sb);
1972
1973         yaffs_deinitialise(dev);
1974
1975         yaffs_gross_unlock(dev);
1976         mutex_lock(&yaffs_context_lock);
1977         list_del_init(&(yaffs_dev_to_lc(dev)->context_list));
1978         mutex_unlock(&yaffs_context_lock);
1979
1980         if (yaffs_dev_to_lc(dev)->spare_buffer) {
1981                 kfree(yaffs_dev_to_lc(dev)->spare_buffer);
1982                 yaffs_dev_to_lc(dev)->spare_buffer = NULL;
1983         }
1984
1985         kfree(dev);
1986 }
1987
1988 static void yaffs_mtd_put_super(struct super_block *sb)
1989 {
1990         struct mtd_info *mtd = yaffs_dev_to_mtd(yaffs_super_to_dev(sb));
1991
1992         if (mtd->sync)
1993                 mtd->sync(mtd);
1994
1995         put_mtd_device(mtd);
1996 }
1997
1998 static const struct super_operations yaffs_super_ops = {
1999         .statfs = yaffs_statfs,
2000         .put_super = yaffs_put_super,
2001         .evict_inode = yaffs_evict_inode,
2002         .sync_fs = yaffs_sync_fs,
2003         .write_super = yaffs_write_super,
2004 };
2005
2006 static struct super_block *yaffs_internal_read_super(int yaffs_version,
2007                                                      struct super_block *sb,
2008                                                      void *data, int silent)
2009 {
2010         int n_blocks;
2011         struct inode *inode = NULL;
2012         struct dentry *root;
2013         struct yaffs_dev *dev = 0;
2014         char devname_buf[BDEVNAME_SIZE + 1];
2015         struct mtd_info *mtd;
2016         int err;
2017         char *data_str = (char *)data;
2018         struct yaffs_linux_context *context = NULL;
2019         struct yaffs_param *param;
2020
2021         int read_only = 0;
2022
2023         struct yaffs_options options;
2024
2025         unsigned mount_id;
2026         int found;
2027         struct yaffs_linux_context *context_iterator;
2028         struct list_head *l;
2029
2030         sb->s_magic = YAFFS_MAGIC;
2031         sb->s_op = &yaffs_super_ops;
2032         sb->s_flags |= MS_NOATIME;
2033
2034         read_only = ((sb->s_flags & MS_RDONLY) != 0);
2035
2036         sb->s_export_op = &yaffs_export_ops;
2037
2038         if (!sb)
2039                 printk(KERN_INFO "yaffs: sb is NULL\n");
2040         else if (!sb->s_dev)
2041                 printk(KERN_INFO "yaffs: sb->s_dev is NULL\n");
2042         else if (!yaffs_devname(sb, devname_buf))
2043                 printk(KERN_INFO "yaffs: devname is NULL\n");
2044         else
2045                 printk(KERN_INFO "yaffs: dev is %d name is \"%s\" %s\n",
2046                        sb->s_dev,
2047                        yaffs_devname(sb, devname_buf), read_only ? "ro" : "rw");
2048
2049         if (!data_str)
2050                 data_str = "";
2051
2052         printk(KERN_INFO "yaffs: passed flags \"%s\"\n", data_str);
2053
2054         memset(&options, 0, sizeof(options));
2055
2056         if (yaffs_parse_options(&options, data_str)) {
2057                 /* Option parsing failed */
2058                 return NULL;
2059         }
2060
2061         sb->s_blocksize = PAGE_CACHE_SIZE;
2062         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2063
2064         yaffs_trace(YAFFS_TRACE_OS,
2065                 "yaffs_read_super: Using yaffs%d", yaffs_version);
2066         yaffs_trace(YAFFS_TRACE_OS,
2067                 "yaffs_read_super: block size %d", (int)(sb->s_blocksize));
2068
2069         yaffs_trace(YAFFS_TRACE_ALWAYS,
2070                 "Attempting MTD mount of %u.%u,\"%s\"",
2071                 MAJOR(sb->s_dev), MINOR(sb->s_dev),
2072                 yaffs_devname(sb, devname_buf));
2073
2074         /* Check it's an mtd device..... */
2075         if (MAJOR(sb->s_dev) != MTD_BLOCK_MAJOR)
2076                 return NULL;    /* This isn't an mtd device */
2077
2078         /* Get the device */
2079         mtd = get_mtd_device(NULL, MINOR(sb->s_dev));
2080         if (!mtd) {
2081                 yaffs_trace(YAFFS_TRACE_ALWAYS,
2082                         "MTD device #%u doesn't appear to exist",
2083                         MINOR(sb->s_dev));
2084                 return NULL;
2085         }
2086         /* Check it's NAND */
2087         if (mtd->type != MTD_NANDFLASH) {
2088                 yaffs_trace(YAFFS_TRACE_ALWAYS,
2089                         "MTD device is not NAND it's type %d",
2090                         mtd->type);
2091                 return NULL;
2092         }
2093
2094         yaffs_trace(YAFFS_TRACE_OS, " erase %p", mtd->erase);
2095         yaffs_trace(YAFFS_TRACE_OS, " read %p", mtd->read);
2096         yaffs_trace(YAFFS_TRACE_OS, " write %p", mtd->write);
2097         yaffs_trace(YAFFS_TRACE_OS, " readoob %p", mtd->read_oob);
2098         yaffs_trace(YAFFS_TRACE_OS, " writeoob %p", mtd->write_oob);
2099         yaffs_trace(YAFFS_TRACE_OS, " block_isbad %p", mtd->block_isbad);
2100         yaffs_trace(YAFFS_TRACE_OS, " block_markbad %p", mtd->block_markbad);
2101         yaffs_trace(YAFFS_TRACE_OS, " %s %d", WRITE_SIZE_STR, WRITE_SIZE(mtd));
2102         yaffs_trace(YAFFS_TRACE_OS, " oobsize %d", mtd->oobsize);
2103         yaffs_trace(YAFFS_TRACE_OS, " erasesize %d", mtd->erasesize);
2104         yaffs_trace(YAFFS_TRACE_OS, " size %lld", mtd->size);
2105
2106 #ifdef CONFIG_YAFFS_AUTO_YAFFS2
2107
2108         if (yaffs_version == 1 && WRITE_SIZE(mtd) >= 2048) {
2109                 yaffs_trace(YAFFS_TRACE_ALWAYS, "auto selecting yaffs2");
2110                 yaffs_version = 2;
2111         }
2112
2113         /* Added NCB 26/5/2006 for completeness */
2114         if (yaffs_version == 2 && !options.inband_tags
2115             && WRITE_SIZE(mtd) == 512) {
2116                 yaffs_trace(YAFFS_TRACE_ALWAYS, "auto selecting yaffs1");
2117                 yaffs_version = 1;
2118         }
2119 #endif
2120
2121         if (yaffs_version == 2) {
2122                 /* Check for version 2 style functions */
2123                 if (!mtd->erase ||
2124                     !mtd->block_isbad ||
2125                     !mtd->block_markbad ||
2126                     !mtd->read ||
2127                     !mtd->write || !mtd->read_oob || !mtd->write_oob) {
2128                         yaffs_trace(YAFFS_TRACE_ALWAYS,
2129                                 "MTD device does not support required functions");
2130                         return NULL;
2131                 }
2132
2133                 if ((WRITE_SIZE(mtd) < YAFFS_MIN_YAFFS2_CHUNK_SIZE ||
2134                      mtd->oobsize < YAFFS_MIN_YAFFS2_SPARE_SIZE) &&
2135                     !options.inband_tags) {
2136                         yaffs_trace(YAFFS_TRACE_ALWAYS,
2137                                 "MTD device does not have the right page sizes");
2138                         return NULL;
2139                 }
2140         } else {
2141                 /* Check for V1 style functions */
2142                 if (!mtd->erase ||
2143                     !mtd->read ||
2144                     !mtd->write || !mtd->read_oob || !mtd->write_oob) {
2145                         yaffs_trace(YAFFS_TRACE_ALWAYS,
2146                                 "MTD device does not support required functions");
2147                         return NULL;
2148                 }
2149
2150                 if (WRITE_SIZE(mtd) < YAFFS_BYTES_PER_CHUNK ||
2151                     mtd->oobsize != YAFFS_BYTES_PER_SPARE) {
2152                         yaffs_trace(YAFFS_TRACE_ALWAYS,
2153                                 "MTD device does not support have the right page sizes");
2154                         return NULL;
2155                 }
2156         }
2157
2158         /* OK, so if we got here, we have an MTD that's NAND and looks
2159          * like it has the right capabilities
2160          * Set the struct yaffs_dev up for mtd
2161          */
2162
2163         if (!read_only && !(mtd->flags & MTD_WRITEABLE)) {
2164                 read_only = 1;
2165                 printk(KERN_INFO
2166                        "yaffs: mtd is read only, setting superblock read only");
2167                 sb->s_flags |= MS_RDONLY;
2168         }
2169
2170         dev = kmalloc(sizeof(struct yaffs_dev), GFP_KERNEL);
2171         context = kmalloc(sizeof(struct yaffs_linux_context), GFP_KERNEL);
2172
2173         if (!dev || !context) {
2174                 if (dev)
2175                         kfree(dev);
2176                 if (context)
2177                         kfree(context);
2178                 dev = NULL;
2179                 context = NULL;
2180         }
2181
2182         if (!dev) {
2183                 /* Deep shit could not allocate device structure */
2184                 yaffs_trace(YAFFS_TRACE_ALWAYS,
2185                         "yaffs_read_super failed trying to allocate yaffs_dev");
2186                 return NULL;
2187         }
2188         memset(dev, 0, sizeof(struct yaffs_dev));
2189         param = &(dev->param);
2190
2191         memset(context, 0, sizeof(struct yaffs_linux_context));
2192         dev->os_context = context;
2193         INIT_LIST_HEAD(&(context->context_list));
2194         context->dev = dev;
2195         context->super = sb;
2196
2197         dev->read_only = read_only;
2198
2199         sb->s_fs_info = dev;
2200
2201         dev->driver_context = mtd;
2202         param->name = mtd->name;
2203
2204         /* Set up the memory size parameters.... */
2205
2206         n_blocks =
2207             YCALCBLOCKS(mtd->size,
2208                         (YAFFS_CHUNKS_PER_BLOCK * YAFFS_BYTES_PER_CHUNK));
2209
2210         param->start_block = 0;
2211         param->end_block = n_blocks - 1;
2212         param->chunks_per_block = YAFFS_CHUNKS_PER_BLOCK;
2213         param->total_bytes_per_chunk = YAFFS_BYTES_PER_CHUNK;
2214         param->n_reserved_blocks = 5;
2215         param->n_caches = (options.no_cache) ? 0 : 10;
2216         param->inband_tags = options.inband_tags;
2217
2218 #ifdef CONFIG_YAFFS_DISABLE_LAZY_LOAD
2219         param->disable_lazy_load = 1;
2220 #endif
2221 #ifdef CONFIG_YAFFS_XATTR
2222         param->enable_xattr = 1;
2223 #endif
2224         if (options.lazy_loading_overridden)
2225                 param->disable_lazy_load = !options.lazy_loading_enabled;
2226
2227 #ifdef CONFIG_YAFFS_DISABLE_TAGS_ECC
2228         param->no_tags_ecc = 1;
2229 #endif
2230
2231 #ifdef CONFIG_YAFFS_DISABLE_BACKGROUND
2232 #else
2233         param->defered_dir_update = 1;
2234 #endif
2235
2236         if (options.tags_ecc_overridden)
2237                 param->no_tags_ecc = !options.tags_ecc_on;
2238
2239 #ifdef CONFIG_YAFFS_EMPTY_LOST_AND_FOUND
2240         param->empty_lost_n_found = 1;
2241 #endif
2242
2243 #ifdef CONFIG_YAFFS_DISABLE_BLOCK_REFRESHING
2244         param->refresh_period = 0;
2245 #else
2246         param->refresh_period = 500;
2247 #endif
2248
2249 #ifdef CONFIG_YAFFS_ALWAYS_CHECK_CHUNK_ERASED
2250         param->always_check_erased = 1;
2251 #endif
2252
2253         if (options.empty_lost_and_found_overridden)
2254                 param->empty_lost_n_found = options.empty_lost_and_found;
2255
2256         /* ... and the functions. */
2257         if (yaffs_version == 2) {
2258                 param->write_chunk_tags_fn = nandmtd2_write_chunk_tags;
2259                 param->read_chunk_tags_fn = nandmtd2_read_chunk_tags;
2260                 param->bad_block_fn = nandmtd2_mark_block_bad;
2261                 param->query_block_fn = nandmtd2_query_block;
2262                 yaffs_dev_to_lc(dev)->spare_buffer =
2263                                 kmalloc(mtd->oobsize, GFP_NOFS);
2264                 param->is_yaffs2 = 1;
2265                 param->total_bytes_per_chunk = mtd->writesize;
2266                 param->chunks_per_block = mtd->erasesize / mtd->writesize;
2267                 n_blocks = YCALCBLOCKS(mtd->size, mtd->erasesize);
2268
2269                 param->start_block = 0;
2270                 param->end_block = n_blocks - 1;
2271         } else {
2272                 /* use the MTD interface in yaffs_mtdif1.c */
2273                 param->write_chunk_tags_fn = nandmtd1_write_chunk_tags;
2274                 param->read_chunk_tags_fn = nandmtd1_read_chunk_tags;
2275                 param->bad_block_fn = nandmtd1_mark_block_bad;
2276                 param->query_block_fn = nandmtd1_query_block;
2277                 param->is_yaffs2 = 0;
2278         }
2279         /* ... and common functions */
2280         param->erase_fn = nandmtd_erase_block;
2281         param->initialise_flash_fn = nandmtd_initialise;
2282
2283         yaffs_dev_to_lc(dev)->put_super_fn = yaffs_mtd_put_super;
2284
2285         param->sb_dirty_fn = yaffs_touch_super;
2286         param->gc_control = yaffs_gc_control_callback;
2287
2288         yaffs_dev_to_lc(dev)->super = sb;
2289
2290 #ifndef CONFIG_YAFFS_DOES_ECC
2291         param->use_nand_ecc = 1;
2292 #endif
2293
2294         param->skip_checkpt_rd = options.skip_checkpoint_read;
2295         param->skip_checkpt_wr = options.skip_checkpoint_write;
2296
2297         mutex_lock(&yaffs_context_lock);
2298         /* Get a mount id */
2299         found = 0;
2300         for (mount_id = 0; !found; mount_id++) {
2301                 found = 1;
2302                 list_for_each(l, &yaffs_context_list) {
2303                         context_iterator =
2304                             list_entry(l, struct yaffs_linux_context,
2305                                        context_list);
2306                         if (context_iterator->mount_id == mount_id)
2307                                 found = 0;
2308                 }
2309         }
2310         context->mount_id = mount_id;
2311
2312         list_add_tail(&(yaffs_dev_to_lc(dev)->context_list),
2313                       &yaffs_context_list);
2314         mutex_unlock(&yaffs_context_lock);
2315
2316         /* Directory search handling... */
2317         INIT_LIST_HEAD(&(yaffs_dev_to_lc(dev)->search_contexts));
2318         param->remove_obj_fn = yaffs_remove_obj_callback;
2319
2320         mutex_init(&(yaffs_dev_to_lc(dev)->gross_lock));
2321
2322         yaffs_gross_lock(dev);
2323
2324         err = yaffs_guts_initialise(dev);
2325
2326         yaffs_trace(YAFFS_TRACE_OS,
2327                 "yaffs_read_super: guts initialised %s",
2328                 (err == YAFFS_OK) ? "OK" : "FAILED");
2329
2330         if (err == YAFFS_OK)
2331                 yaffs_bg_start(dev);
2332
2333         if (!context->bg_thread)
2334                 param->defered_dir_update = 0;
2335
2336         /* Release lock before yaffs_get_inode() */
2337         yaffs_gross_unlock(dev);
2338
2339         /* Create root inode */
2340         if (err == YAFFS_OK)
2341                 inode = yaffs_get_inode(sb, S_IFDIR | 0755, 0, yaffs_root(dev));
2342
2343         if (!inode)
2344                 return NULL;
2345
2346         inode->i_op = &yaffs_dir_inode_operations;
2347         inode->i_fop = &yaffs_dir_operations;
2348
2349         yaffs_trace(YAFFS_TRACE_OS, "yaffs_read_super: got root inode");
2350
2351         root = d_alloc_root(inode);
2352
2353         yaffs_trace(YAFFS_TRACE_OS, "yaffs_read_super: d_alloc_root done");
2354
2355         if (!root) {
2356                 iput(inode);
2357                 return NULL;
2358         }
2359         sb->s_root = root;
2360         sb->s_dirt = !dev->is_checkpointed;
2361         yaffs_trace(YAFFS_TRACE_ALWAYS,
2362                 "yaffs_read_super: is_checkpointed %d",
2363                 dev->is_checkpointed);
2364
2365         yaffs_trace(YAFFS_TRACE_OS, "yaffs_read_super: done");
2366         return sb;
2367 }
2368
2369 static int yaffs_internal_read_super_mtd(struct super_block *sb, void *data,
2370                                          int silent)
2371 {
2372         return yaffs_internal_read_super(1, sb, data, silent) ? 0 : -EINVAL;
2373 }
2374
2375 static int yaffs_read_super(struct file_system_type *fs,
2376                             int flags, const char *dev_name,
2377                             void *data, struct vfsmount *mnt)
2378 {
2379
2380         return get_sb_bdev(fs, flags, dev_name, data,
2381                            yaffs_internal_read_super_mtd, mnt);
2382 }
2383
2384 static struct file_system_type yaffs_fs_type = {
2385         .owner = THIS_MODULE,
2386         .name = "yaffs",
2387         .get_sb = yaffs_read_super,
2388         .kill_sb = kill_block_super,
2389         .fs_flags = FS_REQUIRES_DEV,
2390 };
2391
2392 #ifdef CONFIG_YAFFS_YAFFS2
2393
2394 static int yaffs2_internal_read_super_mtd(struct super_block *sb, void *data,
2395                                           int silent)
2396 {
2397         return yaffs_internal_read_super(2, sb, data, silent) ? 0 : -EINVAL;
2398 }
2399
2400 static int yaffs2_read_super(struct file_system_type *fs,
2401                              int flags, const char *dev_name, void *data,
2402                              struct vfsmount *mnt)
2403 {
2404         return get_sb_bdev(fs, flags, dev_name, data,
2405                            yaffs2_internal_read_super_mtd, mnt);
2406 }
2407
2408 static struct file_system_type yaffs2_fs_type = {
2409         .owner = THIS_MODULE,
2410         .name = "yaffs2",
2411         .get_sb = yaffs2_read_super,
2412         .kill_sb = kill_block_super,
2413         .fs_flags = FS_REQUIRES_DEV,
2414 };
2415 #endif /* CONFIG_YAFFS_YAFFS2 */
2416
2417 static struct proc_dir_entry *my_proc_entry;
2418
2419 static char *yaffs_dump_dev_part0(char *buf, struct yaffs_dev *dev)
2420 {
2421         struct yaffs_param *param = &dev->param;
2422         buf += sprintf(buf, "start_block........... %d\n", param->start_block);
2423         buf += sprintf(buf, "end_block............. %d\n", param->end_block);
2424         buf += sprintf(buf, "total_bytes_per_chunk. %d\n",
2425                         param->total_bytes_per_chunk);
2426         buf += sprintf(buf, "use_nand_ecc.......... %d\n",
2427                         param->use_nand_ecc);
2428         buf += sprintf(buf, "no_tags_ecc........... %d\n", param->no_tags_ecc);
2429         buf += sprintf(buf, "is_yaffs2............. %d\n", param->is_yaffs2);
2430         buf += sprintf(buf, "inband_tags........... %d\n", param->inband_tags);
2431         buf += sprintf(buf, "empty_lost_n_found.... %d\n",
2432                         param->empty_lost_n_found);
2433         buf += sprintf(buf, "disable_lazy_load..... %d\n",
2434                         param->disable_lazy_load);
2435         buf += sprintf(buf, "refresh_period........ %d\n",
2436                         param->refresh_period);
2437         buf += sprintf(buf, "n_caches.............. %d\n", param->n_caches);
2438         buf += sprintf(buf, "n_reserved_blocks..... %d\n",
2439                         param->n_reserved_blocks);
2440         buf += sprintf(buf, "always_check_erased... %d\n",
2441                         param->always_check_erased);
2442
2443         return buf;
2444 }
2445
2446 static char *yaffs_dump_dev_part1(char *buf, struct yaffs_dev *dev)
2447 {
2448         buf +=
2449             sprintf(buf, "data_bytes_per_chunk.. %d\n",
2450                     dev->data_bytes_per_chunk);
2451         buf += sprintf(buf, "chunk_grp_bits........ %d\n", dev->chunk_grp_bits);
2452         buf += sprintf(buf, "chunk_grp_size........ %d\n", dev->chunk_grp_size);
2453         buf +=
2454             sprintf(buf, "n_erased_blocks....... %d\n", dev->n_erased_blocks);
2455         buf +=
2456             sprintf(buf, "blocks_in_checkpt..... %d\n", dev->blocks_in_checkpt);
2457         buf += sprintf(buf, "\n");
2458         buf += sprintf(buf, "n_tnodes.............. %d\n", dev->n_tnodes);
2459         buf += sprintf(buf, "n_obj................. %d\n", dev->n_obj);
2460         buf += sprintf(buf, "n_free_chunks......... %d\n", dev->n_free_chunks);
2461         buf += sprintf(buf, "\n");
2462         buf += sprintf(buf, "n_page_writes......... %u\n", dev->n_page_writes);
2463         buf += sprintf(buf, "n_page_reads.......... %u\n", dev->n_page_reads);
2464         buf += sprintf(buf, "n_erasures............ %u\n", dev->n_erasures);
2465         buf += sprintf(buf, "n_gc_copies........... %u\n", dev->n_gc_copies);
2466         buf += sprintf(buf, "all_gcs............... %u\n", dev->all_gcs);
2467         buf +=
2468             sprintf(buf, "passive_gc_count...... %u\n", dev->passive_gc_count);
2469         buf +=
2470             sprintf(buf, "oldest_dirty_gc_count. %u\n",
2471                     dev->oldest_dirty_gc_count);
2472         buf += sprintf(buf, "n_gc_blocks........... %u\n", dev->n_gc_blocks);
2473         buf += sprintf(buf, "bg_gcs................ %u\n", dev->bg_gcs);
2474         buf +=
2475             sprintf(buf, "n_retired_writes...... %u\n", dev->n_retired_writes);
2476         buf +=
2477             sprintf(buf, "n_retired_blocks...... %u\n", dev->n_retired_blocks);
2478         buf += sprintf(buf, "n_ecc_fixed........... %u\n", dev->n_ecc_fixed);
2479         buf += sprintf(buf, "n_ecc_unfixed......... %u\n", dev->n_ecc_unfixed);
2480         buf +=
2481             sprintf(buf, "n_tags_ecc_fixed...... %u\n", dev->n_tags_ecc_fixed);
2482         buf +=
2483             sprintf(buf, "n_tags_ecc_unfixed.... %u\n",
2484                     dev->n_tags_ecc_unfixed);
2485         buf += sprintf(buf, "cache_hits............ %u\n", dev->cache_hits);
2486         buf +=
2487             sprintf(buf, "n_deleted_files....... %u\n", dev->n_deleted_files);
2488         buf +=
2489             sprintf(buf, "n_unlinked_files...... %u\n", dev->n_unlinked_files);
2490         buf += sprintf(buf, "refresh_count......... %u\n", dev->refresh_count);
2491         buf += sprintf(buf, "n_bg_deletions........ %u\n", dev->n_bg_deletions);
2492
2493         return buf;
2494 }
2495
2496 static int yaffs_proc_read(char *page,
2497                            char **start,
2498                            off_t offset, int count, int *eof, void *data)
2499 {
2500         struct list_head *item;
2501         char *buf = page;
2502         int step = offset;
2503         int n = 0;
2504
2505         /* Get proc_file_read() to step 'offset' by one on each sucessive call.
2506          * We use 'offset' (*ppos) to indicate where we are in dev_list.
2507          * This also assumes the user has posted a read buffer large
2508          * enough to hold the complete output; but that's life in /proc.
2509          */
2510
2511         *(int *)start = 1;
2512
2513         /* Print header first */
2514         if (step == 0)
2515                 buf += sprintf(buf, "YAFFS built:" __DATE__ " " __TIME__ "\n");
2516         else if (step == 1)
2517                 buf += sprintf(buf, "\n");
2518         else {
2519                 step -= 2;
2520
2521                 mutex_lock(&yaffs_context_lock);
2522
2523                 /* Locate and print the Nth entry.  Order N-squared but N is small. */
2524                 list_for_each(item, &yaffs_context_list) {
2525                         struct yaffs_linux_context *dc =
2526                             list_entry(item, struct yaffs_linux_context,
2527                                        context_list);
2528                         struct yaffs_dev *dev = dc->dev;
2529
2530                         if (n < (step & ~1)) {
2531                                 n += 2;
2532                                 continue;
2533                         }
2534                         if ((step & 1) == 0) {
2535                                 buf +=
2536                                     sprintf(buf, "\nDevice %d \"%s\"\n", n,
2537                                             dev->param.name);
2538                                 buf = yaffs_dump_dev_part0(buf, dev);
2539                         } else {
2540                                 buf = yaffs_dump_dev_part1(buf, dev);
2541                         }
2542
2543                         break;
2544                 }
2545                 mutex_unlock(&yaffs_context_lock);
2546         }
2547
2548         return buf - page < count ? buf - page : count;
2549 }
2550
2551
2552 /**
2553  * Set the verbosity of the warnings and error messages.
2554  *
2555  * Note that the names can only be a..z or _ with the current code.
2556  */
2557
2558 static struct {
2559         char *mask_name;
2560         unsigned mask_bitfield;
2561 } mask_flags[] = {
2562         {"allocate", YAFFS_TRACE_ALLOCATE},
2563         {"always", YAFFS_TRACE_ALWAYS},
2564         {"background", YAFFS_TRACE_BACKGROUND},
2565         {"bad_blocks", YAFFS_TRACE_BAD_BLOCKS},
2566         {"buffers", YAFFS_TRACE_BUFFERS},
2567         {"bug", YAFFS_TRACE_BUG},
2568         {"checkpt", YAFFS_TRACE_CHECKPOINT},
2569         {"deletion", YAFFS_TRACE_DELETION},
2570         {"erase", YAFFS_TRACE_ERASE},
2571         {"error", YAFFS_TRACE_ERROR},
2572         {"gc_detail", YAFFS_TRACE_GC_DETAIL},
2573         {"gc", YAFFS_TRACE_GC},
2574         {"lock", YAFFS_TRACE_LOCK},
2575         {"mtd", YAFFS_TRACE_MTD},
2576         {"nandaccess", YAFFS_TRACE_NANDACCESS},
2577         {"os", YAFFS_TRACE_OS},
2578         {"scan_debug", YAFFS_TRACE_SCAN_DEBUG},
2579         {"scan", YAFFS_TRACE_SCAN},
2580         {"mount", YAFFS_TRACE_MOUNT},
2581         {"tracing", YAFFS_TRACE_TRACING},
2582         {"sync", YAFFS_TRACE_SYNC},
2583         {"write", YAFFS_TRACE_WRITE},
2584         {"verify", YAFFS_TRACE_VERIFY},
2585         {"verify_nand", YAFFS_TRACE_VERIFY_NAND},
2586         {"verify_full", YAFFS_TRACE_VERIFY_FULL},
2587         {"verify_all", YAFFS_TRACE_VERIFY_ALL},
2588         {"all", 0xffffffff},
2589         {"none", 0},
2590         {NULL, 0},
2591 };
2592
2593 #define MAX_MASK_NAME_LENGTH 40
2594 static int yaffs_proc_write_trace_options(struct file *file, const char *buf,
2595                                           unsigned long count, void *data)
2596 {
2597         unsigned rg = 0, mask_bitfield;
2598         char *end;
2599         char *mask_name;
2600         const char *x;
2601         char substring[MAX_MASK_NAME_LENGTH + 1];
2602         int i;
2603         int done = 0;
2604         int add, len = 0;
2605         int pos = 0;
2606
2607         rg = yaffs_trace_mask;
2608
2609         while (!done && (pos < count)) {
2610                 done = 1;
2611                 while ((pos < count) && isspace(buf[pos]))
2612                         pos++;
2613
2614                 switch (buf[pos]) {
2615                 case '+':
2616                 case '-':
2617                 case '=':
2618                         add = buf[pos];
2619                         pos++;
2620                         break;
2621
2622                 default:
2623                         add = ' ';
2624                         break;
2625                 }
2626                 mask_name = NULL;
2627
2628                 mask_bitfield = simple_strtoul(buf + pos, &end, 0);
2629
2630                 if (end > buf + pos) {
2631                         mask_name = "numeral";
2632                         len = end - (buf + pos);
2633                         pos += len;
2634                         done = 0;
2635                 } else {
2636                         for (x = buf + pos, i = 0;
2637                              (*x == '_' || (*x >= 'a' && *x <= 'z')) &&
2638                              i < MAX_MASK_NAME_LENGTH; x++, i++, pos++)
2639                                 substring[i] = *x;
2640                         substring[i] = '\0';
2641
2642                         for (i = 0; mask_flags[i].mask_name != NULL; i++) {
2643                                 if (strcmp(substring, mask_flags[i].mask_name)
2644                                     == 0) {
2645                                         mask_name = mask_flags[i].mask_name;
2646                                         mask_bitfield =
2647                                             mask_flags[i].mask_bitfield;
2648                                         done = 0;
2649                                         break;
2650                                 }
2651                         }
2652                 }
2653
2654                 if (mask_name != NULL) {
2655                         done = 0;
2656                         switch (add) {
2657                         case '-':
2658                                 rg &= ~mask_bitfield;
2659                                 break;
2660                         case '+':
2661                                 rg |= mask_bitfield;
2662                                 break;
2663                         case '=':
2664                                 rg = mask_bitfield;
2665                                 break;
2666                         default:
2667                                 rg |= mask_bitfield;
2668                                 break;
2669                         }
2670                 }
2671         }
2672
2673         yaffs_trace_mask = rg | YAFFS_TRACE_ALWAYS;
2674
2675         printk(KERN_DEBUG "new trace = 0x%08X\n", yaffs_trace_mask);
2676
2677         if (rg & YAFFS_TRACE_ALWAYS) {
2678                 for (i = 0; mask_flags[i].mask_name != NULL; i++) {
2679                         char flag;
2680                         flag = ((rg & mask_flags[i].mask_bitfield) ==
2681                                 mask_flags[i].mask_bitfield) ? '+' : '-';
2682                         printk(KERN_DEBUG "%c%s\n", flag,
2683                                mask_flags[i].mask_name);
2684                 }
2685         }
2686
2687         return count;
2688 }
2689
2690 static int yaffs_proc_write(struct file *file, const char *buf,
2691                             unsigned long count, void *data)
2692 {
2693         return yaffs_proc_write_trace_options(file, buf, count, data);
2694 }
2695
2696 /* Stuff to handle installation of file systems */
2697 struct file_system_to_install {
2698         struct file_system_type *fst;
2699         int installed;
2700 };
2701
2702 static struct file_system_to_install fs_to_install[] = {
2703         {&yaffs_fs_type, 0},
2704         {&yaffs2_fs_type, 0},
2705         {NULL, 0}
2706 };
2707
2708 static int __init init_yaffs_fs(void)
2709 {
2710         int error = 0;
2711         struct file_system_to_install *fsinst;
2712
2713         yaffs_trace(YAFFS_TRACE_ALWAYS,
2714                 "yaffs built " __DATE__ " " __TIME__ " Installing.");
2715
2716 #ifdef CONFIG_YAFFS_ALWAYS_CHECK_CHUNK_ERASED
2717         yaffs_trace(YAFFS_TRACE_ALWAYS,
2718                 "\n\nYAFFS-WARNING CONFIG_YAFFS_ALWAYS_CHECK_CHUNK_ERASED selected.\n\n\n");
2719 #endif
2720
2721         mutex_init(&yaffs_context_lock);
2722
2723         /* Install the proc_fs entries */
2724         my_proc_entry = create_proc_entry("yaffs",
2725                                           S_IRUGO | S_IFREG, YPROC_ROOT);
2726
2727         if (my_proc_entry) {
2728                 my_proc_entry->write_proc = yaffs_proc_write;
2729                 my_proc_entry->read_proc = yaffs_proc_read;
2730                 my_proc_entry->data = NULL;
2731         } else {
2732                 return -ENOMEM;
2733         }
2734
2735
2736         /* Now add the file system entries */
2737
2738         fsinst = fs_to_install;
2739
2740         while (fsinst->fst && !error) {
2741                 error = register_filesystem(fsinst->fst);
2742                 if (!error)
2743                         fsinst->installed = 1;
2744                 fsinst++;
2745         }
2746
2747         /* Any errors? uninstall  */
2748         if (error) {
2749                 fsinst = fs_to_install;
2750
2751                 while (fsinst->fst) {
2752                         if (fsinst->installed) {
2753                                 unregister_filesystem(fsinst->fst);
2754                                 fsinst->installed = 0;
2755                         }
2756                         fsinst++;
2757                 }
2758         }
2759
2760         return error;
2761 }
2762
2763 static void __exit exit_yaffs_fs(void)
2764 {
2765
2766         struct file_system_to_install *fsinst;
2767
2768         yaffs_trace(YAFFS_TRACE_ALWAYS,
2769                 "yaffs built " __DATE__ " " __TIME__ " removing.");
2770
2771         remove_proc_entry("yaffs", YPROC_ROOT);
2772
2773         fsinst = fs_to_install;
2774
2775         while (fsinst->fst) {
2776                 if (fsinst->installed) {
2777                         unregister_filesystem(fsinst->fst);
2778                         fsinst->installed = 0;
2779                 }
2780                 fsinst++;
2781         }
2782 }
2783
2784 module_init(init_yaffs_fs)
2785     module_exit(exit_yaffs_fs)
2786
2787     MODULE_DESCRIPTION("YAFFS2 - a NAND specific flash file system");
2788 MODULE_AUTHOR("Charles Manning, Aleph One Ltd., 2002-2010");
2789 MODULE_LICENSE("GPL");