fs/jffs2/fs.c

   1 /*
   2  * JFFS2 -- Journalling Flash File System, Version 2.
   3  *
   4  * Copyright © 2001-2007 Red Hat, Inc.
   5  * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
   6  *
   7  * Created by David Woodhouse <dwmw2@infradead.org>
   8  *
   9  * For licensing information, see the file 'LICENCE' in this directory.
  10  *
  11  */
  12
  13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  14
  15 #include <linux/capability.h>
  16 #include <linux/kernel.h>
  17 #include <linux/sched.h>
  18 #include <linux/fs.h>
  19 #include <linux/list.h>
  20 #include <linux/mtd/mtd.h>
  21 #include <linux/pagemap.h>
  22 #include <linux/slab.h>
  23 #include <linux/vmalloc.h>
  24 #include <linux/vfs.h>
  25 #include <linux/crc32.h>
  26 #include "nodelist.h"
  27
  28 static int jffs2_flash_setup(struct jffs2_sb_info *c);
  29
  30 int jffs2_do_setattr (struct inode *inode, struct iattr *iattr)
  31 {
  32         struct jffs2_full_dnode *old_metadata, *new_metadata;
  33         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
  34         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
  35         struct jffs2_raw_inode *ri;
  36         union jffs2_device_node dev;
  37         unsigned char *mdata = NULL;
  38         int mdatalen = 0;
  39         unsigned int ivalid;
  40         uint32_t alloclen;
  41         int ret;
  42         int alloc_type = ALLOC_NORMAL;
  43
  44         jffs2_dbg(1, "%s(): ino #%lu\n", __func__, inode->i_ino);
  45
  46         /* Special cases - we don't want more than one data node
  47            for these types on the medium at any time. So setattr
  48            must read the original data associated with the node
  49            (i.e. the device numbers or the target name) and write
  50            it out again with the appropriate data attached */
  51         if (S_ISBLK(inode->i_mode) || S_ISCHR(inode->i_mode)) {
  52                 /* For these, we don't actually need to read the old node */
  53                 mdatalen = jffs2_encode_dev(&dev, inode->i_rdev);
  54                 mdata = (char *)&dev;
  55                 jffs2_dbg(1, "%s(): Writing %d bytes of kdev_t\n",
  56                           __func__, mdatalen);
  57         } else if (S_ISLNK(inode->i_mode)) {
  58                 mutex_lock(&f->sem);
  59                 mdatalen = f->metadata->size;
  60                 mdata = kmalloc(f->metadata->size, GFP_USER);
  61                 if (!mdata) {
  62                         mutex_unlock(&f->sem);
  63                         return -ENOMEM;
  64                 }
  65                 ret = jffs2_read_dnode(c, f, f->metadata, mdata, 0, mdatalen);
  66                 if (ret) {
  67                         mutex_unlock(&f->sem);
  68                         kfree(mdata);
  69                         return ret;
  70                 }
  71                 mutex_unlock(&f->sem);
  72                 jffs2_dbg(1, "%s(): Writing %d bytes of symlink target\n",
  73                           __func__, mdatalen);
  74         }
  75
  76         ri = jffs2_alloc_raw_inode();
  77         if (!ri) {
  78                 if (S_ISLNK(inode->i_mode))
  79                         kfree(mdata);
  80                 return -ENOMEM;
  81         }
  82
  83         ret = jffs2_reserve_space(c, sizeof(*ri) + mdatalen, &alloclen,
  84                                   ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
  85         if (ret) {
  86                 jffs2_free_raw_inode(ri);
  87                 if (S_ISLNK(inode->i_mode))
  88                          kfree(mdata);
  89                 return ret;
  90         }
  91         mutex_lock(&f->sem);
  92         ivalid = iattr->ia_valid;
  93
  94         ri->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
  95         ri->nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE);
  96         ri->totlen = cpu_to_je32(sizeof(*ri) + mdatalen);
  97         ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
  98
  99         ri->ino = cpu_to_je32(inode->i_ino);
 100         ri->version = cpu_to_je32(++f->highest_version);
 101
 102         ri->uid = cpu_to_je16((ivalid & ATTR_UID)?
 103                 from_kuid(&init_user_ns, iattr->ia_uid):i_uid_read(inode));
 104         ri->gid = cpu_to_je16((ivalid & ATTR_GID)?
 105                 from_kgid(&init_user_ns, iattr->ia_gid):i_gid_read(inode));
 106
 107         if (ivalid & ATTR_MODE)
 108                 ri->mode = cpu_to_jemode(iattr->ia_mode);
 109         else
 110                 ri->mode = cpu_to_jemode(inode->i_mode);
 111
 112
 113         ri->isize = cpu_to_je32((ivalid & ATTR_SIZE)?iattr->ia_size:inode->i_size);
 114         ri->atime = cpu_to_je32(I_SEC((ivalid & ATTR_ATIME)?iattr->ia_atime:inode->i_atime));
 115         ri->mtime = cpu_to_je32(I_SEC((ivalid & ATTR_MTIME)?iattr->ia_mtime:inode->i_mtime));
 116         ri->ctime = cpu_to_je32(I_SEC((ivalid & ATTR_CTIME)?iattr->ia_ctime:inode->i_ctime));
 117
 118         ri->offset = cpu_to_je32(0);
 119         ri->csize = ri->dsize = cpu_to_je32(mdatalen);
 120         ri->compr = JFFS2_COMPR_NONE;
 121         if (ivalid & ATTR_SIZE && inode->i_size < iattr->ia_size) {
 122                 /* It's an extension. Make it a hole node */
 123                 ri->compr = JFFS2_COMPR_ZERO;
 124                 ri->dsize = cpu_to_je32(iattr->ia_size - inode->i_size);
 125                 ri->offset = cpu_to_je32(inode->i_size);
 126         } else if (ivalid & ATTR_SIZE && !iattr->ia_size) {
 127                 /* For truncate-to-zero, treat it as deletion because
 128                    it'll always be obsoleting all previous nodes */
 129                 alloc_type = ALLOC_DELETION;
 130         }
 131         ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
 132         if (mdatalen)
 133                 ri->data_crc = cpu_to_je32(crc32(0, mdata, mdatalen));
 134         else
 135                 ri->data_crc = cpu_to_je32(0);
 136
 137         new_metadata = jffs2_write_dnode(c, f, ri, mdata, mdatalen, alloc_type);
 138         if (S_ISLNK(inode->i_mode))
 139                 kfree(mdata);
 140
 141         if (IS_ERR(new_metadata)) {
 142                 jffs2_complete_reservation(c);
 143                 jffs2_free_raw_inode(ri);
 144                 mutex_unlock(&f->sem);
 145                 return PTR_ERR(new_metadata);
 146         }
 147         /* It worked. Update the inode */
 148         inode->i_atime = ITIME(je32_to_cpu(ri->atime));
 149         inode->i_ctime = ITIME(je32_to_cpu(ri->ctime));
 150         inode->i_mtime = ITIME(je32_to_cpu(ri->mtime));
 151         inode->i_mode = jemode_to_cpu(ri->mode);
 152         i_uid_write(inode, je16_to_cpu(ri->uid));
 153         i_gid_write(inode, je16_to_cpu(ri->gid));
 154
 155
 156         old_metadata = f->metadata;
 157
 158         if (ivalid & ATTR_SIZE && inode->i_size > iattr->ia_size)
 159                 jffs2_truncate_fragtree (c, &f->fragtree, iattr->ia_size);
 160
 161         if (ivalid & ATTR_SIZE && inode->i_size < iattr->ia_size) {
 162                 jffs2_add_full_dnode_to_inode(c, f, new_metadata);
 163                 inode->i_size = iattr->ia_size;
 164                 inode->i_blocks = (inode->i_size + 511) >> 9;
 165                 f->metadata = NULL;
 166         } else {
 167                 f->metadata = new_metadata;
 168         }
 169         if (old_metadata) {
 170                 jffs2_mark_node_obsolete(c, old_metadata->raw);
 171                 jffs2_free_full_dnode(old_metadata);
 172         }
 173         jffs2_free_raw_inode(ri);
 174
 175         mutex_unlock(&f->sem);
 176         jffs2_complete_reservation(c);
 177
 178         /* We have to do the truncate_setsize() without f->sem held, since
 179            some pages may be locked and waiting for it in readpage().
 180            We are protected from a simultaneous write() extending i_size
 181            back past iattr->ia_size, because do_truncate() holds the
 182            generic inode semaphore. */
 183         if (ivalid & ATTR_SIZE && inode->i_size > iattr->ia_size) {
 184                 truncate_setsize(inode, iattr->ia_size);
 185                 inode->i_blocks = (inode->i_size + 511) >> 9;
 186         }
 187
 188         return 0;
 189 }
 190
 191 int jffs2_setattr(struct dentry *dentry, struct iattr *iattr)
 192 {
 193         struct inode *inode = d_inode(dentry);
 194         int rc;
 195
 196         rc = inode_change_ok(inode, iattr);
 197         if (rc)
 198                 return rc;
 199
 200         rc = jffs2_do_setattr(inode, iattr);
 201         if (!rc && (iattr->ia_valid & ATTR_MODE))
 202                 rc = posix_acl_chmod(inode, inode->i_mode);
 203
 204         return rc;
 205 }
 206
 207 int jffs2_statfs(struct dentry *dentry, struct kstatfs *buf)
 208 {
 209         struct jffs2_sb_info *c = JFFS2_SB_INFO(dentry->d_sb);
 210         unsigned long avail;
 211
 212         buf->f_type = JFFS2_SUPER_MAGIC;
 213         buf->f_bsize = 1 << PAGE_SHIFT;
 214         buf->f_blocks = c->flash_size >> PAGE_SHIFT;
 215         buf->f_files = 0;
 216         buf->f_ffree = 0;
 217         buf->f_namelen = JFFS2_MAX_NAME_LEN;
 218         buf->f_fsid.val[0] = JFFS2_SUPER_MAGIC;
 219         buf->f_fsid.val[1] = c->mtd->index;
 220
 221         spin_lock(&c->erase_completion_lock);
 222         avail = c->dirty_size + c->free_size;
 223         if (avail > c->sector_size * c->resv_blocks_write)
 224                 avail -= c->sector_size * c->resv_blocks_write;
 225         else
 226                 avail = 0;
 227         spin_unlock(&c->erase_completion_lock);
 228
 229         buf->f_bavail = buf->f_bfree = avail >> PAGE_SHIFT;
 230
 231         return 0;
 232 }
 233
 234
 235 void jffs2_evict_inode (struct inode *inode)
 236 {
 237         /* We can forget about this inode for now - drop all
 238          *  the nodelists associated with it, etc.
 239          */
 240         struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
 241         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
 242
 243         jffs2_dbg(1, "%s(): ino #%lu mode %o\n",
 244                   __func__, inode->i_ino, inode->i_mode);
 245         truncate_inode_pages_final(&inode->i_data);
 246         clear_inode(inode);
 247         jffs2_do_clear_inode(c, f);
 248 }
 249
 250 struct inode *jffs2_iget(struct super_block *sb, unsigned long ino)
 251 {
 252         struct jffs2_inode_info *f;
 253         struct jffs2_sb_info *c;
 254         struct jffs2_raw_inode latest_node;
 255         union jffs2_device_node jdev;
 256         struct inode *inode;
 257         dev_t rdev = 0;
 258         int ret;
 259
 260         jffs2_dbg(1, "%s(): ino == %lu\n", __func__, ino);
 261
 262         inode = iget_locked(sb, ino);
 263         if (!inode)
 264                 return ERR_PTR(-ENOMEM);
 265         if (!(inode->i_state & I_NEW))
 266                 return inode;
 267
 268         f = JFFS2_INODE_INFO(inode);
 269         c = JFFS2_SB_INFO(inode->i_sb);
 270
 271         jffs2_init_inode_info(f);
 272         mutex_lock(&f->sem);
 273
 274         ret = jffs2_do_read_inode(c, f, inode->i_ino, &latest_node);
 275         if (ret)
 276                 goto error;
 277
 278         inode->i_mode = jemode_to_cpu(latest_node.mode);
 279         i_uid_write(inode, je16_to_cpu(latest_node.uid));
 280         i_gid_write(inode, je16_to_cpu(latest_node.gid));
 281         inode->i_size = je32_to_cpu(latest_node.isize);
 282         inode->i_atime = ITIME(je32_to_cpu(latest_node.atime));
 283         inode->i_mtime = ITIME(je32_to_cpu(latest_node.mtime));
 284         inode->i_ctime = ITIME(je32_to_cpu(latest_node.ctime));
 285
 286         set_nlink(inode, f->inocache->pino_nlink);
 287
 288         inode->i_blocks = (inode->i_size + 511) >> 9;
 289
 290         switch (inode->i_mode & S_IFMT) {
 291
 292         case S_IFLNK:
 293                 inode->i_op = &jffs2_symlink_inode_operations;
 294                 inode->i_link = f->target;
 295                 break;
 296
 297         case S_IFDIR:
 298         {
 299                 struct jffs2_full_dirent *fd;
 300                 set_nlink(inode, 2); /* parent and '.' */
 301
 302                 for (fd=f->dents; fd; fd = fd->next) {
 303                         if (fd->type == DT_DIR && fd->ino)
 304                                 inc_nlink(inode);
 305                 }
 306                 /* Root dir gets i_nlink 3 for some reason */
 307                 if (inode->i_ino == 1)
 308                         inc_nlink(inode);
 309
 310                 inode->i_op = &jffs2_dir_inode_operations;
 311                 inode->i_fop = &jffs2_dir_operations;
 312                 break;
 313         }
 314         case S_IFREG:
 315                 inode->i_op = &jffs2_file_inode_operations;
 316                 inode->i_fop = &jffs2_file_operations;
 317                 inode->i_mapping->a_ops = &jffs2_file_address_operations;
 318                 inode->i_mapping->nrpages = 0;
 319                 break;
 320
 321         case S_IFBLK:
 322         case S_IFCHR:
 323                 /* Read the device numbers from the media */
 324                 if (f->metadata->size != sizeof(jdev.old_id) &&
 325                     f->metadata->size != sizeof(jdev.new_id)) {
 326                         pr_notice("Device node has strange size %d\n",
 327                                   f->metadata->size);
 328                         goto error_io;
 329                 }
 330                 jffs2_dbg(1, "Reading device numbers from flash\n");
 331                 ret = jffs2_read_dnode(c, f, f->metadata, (char *)&jdev, 0, f->metadata->size);
 332                 if (ret < 0) {
 333                         /* Eep */
 334                         pr_notice("Read device numbers for inode %lu failed\n",
 335                                   (unsigned long)inode->i_ino);
 336                         goto error;
 337                 }
 338                 if (f->metadata->size == sizeof(jdev.old_id))
 339                         rdev = old_decode_dev(je16_to_cpu(jdev.old_id));
 340                 else
 341                         rdev = new_decode_dev(je32_to_cpu(jdev.new_id));
 342
 343         case S_IFSOCK:
 344         case S_IFIFO:
 345                 inode->i_op = &jffs2_file_inode_operations;
 346                 init_special_inode(inode, inode->i_mode, rdev);
 347                 break;
 348
 349         default:
 350                 pr_warn("%s(): Bogus i_mode %o for ino %lu\n",
 351                         __func__, inode->i_mode, (unsigned long)inode->i_ino);
 352         }
 353
 354         mutex_unlock(&f->sem);
 355
 356         jffs2_dbg(1, "jffs2_read_inode() returning\n");
 357         unlock_new_inode(inode);
 358         return inode;
 359
 360 error_io:
 361         ret = -EIO;
 362 error:
 363         mutex_unlock(&f->sem);
 364         jffs2_do_clear_inode(c, f);
 365         iget_failed(inode);
 366         return ERR_PTR(ret);
 367 }
 368
 369 void jffs2_dirty_inode(struct inode *inode, int flags)
 370 {
 371         struct iattr iattr;
 372
 373         if (!(inode->i_state & I_DIRTY_DATASYNC)) {
 374                 jffs2_dbg(2, "%s(): not calling setattr() for ino #%lu\n",
 375                           __func__, inode->i_ino);
 376                 return;
 377         }
 378
 379         jffs2_dbg(1, "%s(): calling setattr() for ino #%lu\n",
 380                   __func__, inode->i_ino);
 381
 382         iattr.ia_valid = ATTR_MODE|ATTR_UID|ATTR_GID|ATTR_ATIME|ATTR_MTIME|ATTR_CTIME;
 383         iattr.ia_mode = inode->i_mode;
 384         iattr.ia_uid = inode->i_uid;
 385         iattr.ia_gid = inode->i_gid;
 386         iattr.ia_atime = inode->i_atime;
 387         iattr.ia_mtime = inode->i_mtime;
 388         iattr.ia_ctime = inode->i_ctime;
 389
 390         jffs2_do_setattr(inode, &iattr);
 391 }
 392
 393 int jffs2_do_remount_fs(struct super_block *sb, int *flags, char *data)
 394 {
 395         struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
 396
 397         if (c->flags & JFFS2_SB_FLAG_RO && !(sb->s_flags & MS_RDONLY))
 398                 return -EROFS;
 399
 400         /* We stop if it was running, then restart if it needs to.
 401            This also catches the case where it was stopped and this
 402            is just a remount to restart it.
 403            Flush the writebuffer, if neccecary, else we loose it */
 404         if (!(sb->s_flags & MS_RDONLY)) {
 405                 jffs2_stop_garbage_collect_thread(c);
 406                 mutex_lock(&c->alloc_sem);
 407                 jffs2_flush_wbuf_pad(c);
 408                 mutex_unlock(&c->alloc_sem);
 409         }
 410
 411         if (!(*flags & MS_RDONLY))
 412                 jffs2_start_garbage_collect_thread(c);
 413
 414         *flags |= MS_NOATIME;
 415         return 0;
 416 }
 417
 418 /* jffs2_new_inode: allocate a new inode and inocache, add it to the hash,
 419    fill in the raw_inode while you're at it. */
 420 struct inode *jffs2_new_inode (struct inode *dir_i, umode_t mode, struct jffs2_raw_inode *ri)
 421 {
 422         struct inode *inode;
 423         struct super_block *sb = dir_i->i_sb;
 424         struct jffs2_sb_info *c;
 425         struct jffs2_inode_info *f;
 426         int ret;
 427
 428         jffs2_dbg(1, "%s(): dir_i %ld, mode 0x%x\n",
 429                   __func__, dir_i->i_ino, mode);
 430
 431         c = JFFS2_SB_INFO(sb);
 432
 433         inode = new_inode(sb);
 434
 435         if (!inode)
 436                 return ERR_PTR(-ENOMEM);
 437
 438         f = JFFS2_INODE_INFO(inode);
 439         jffs2_init_inode_info(f);
 440         mutex_lock(&f->sem);
 441
 442         memset(ri, 0, sizeof(*ri));
 443         /* Set OS-specific defaults for new inodes */
 444         ri->uid = cpu_to_je16(from_kuid(&init_user_ns, current_fsuid()));
 445
 446         if (dir_i->i_mode & S_ISGID) {
 447                 ri->gid = cpu_to_je16(i_gid_read(dir_i));
 448                 if (S_ISDIR(mode))
 449                         mode |= S_ISGID;
 450         } else {
 451                 ri->gid = cpu_to_je16(from_kgid(&init_user_ns, current_fsgid()));
 452         }
 453
 454         /* POSIX ACLs have to be processed now, at least partly.
 455            The umask is only applied if there's no default ACL */
 456         ret = jffs2_init_acl_pre(dir_i, inode, &mode);
 457         if (ret) {
 458                 mutex_unlock(&f->sem);
 459                 make_bad_inode(inode);
 460                 iput(inode);
 461                 return ERR_PTR(ret);
 462         }
 463         ret = jffs2_do_new_inode (c, f, mode, ri);
 464         if (ret) {
 465                 mutex_unlock(&f->sem);
 466                 make_bad_inode(inode);
 467                 iput(inode);
 468                 return ERR_PTR(ret);
 469         }
 470         set_nlink(inode, 1);
 471         inode->i_ino = je32_to_cpu(ri->ino);
 472         inode->i_mode = jemode_to_cpu(ri->mode);
 473         i_gid_write(inode, je16_to_cpu(ri->gid));
 474         i_uid_write(inode, je16_to_cpu(ri->uid));
 475         inode->i_atime = inode->i_ctime = inode->i_mtime = CURRENT_TIME_SEC;
 476         ri->atime = ri->mtime = ri->ctime = cpu_to_je32(I_SEC(inode->i_mtime));
 477
 478         inode->i_blocks = 0;
 479         inode->i_size = 0;
 480
 481         if (insert_inode_locked(inode) < 0) {
 482                 mutex_unlock(&f->sem);
 483                 make_bad_inode(inode);
 484                 iput(inode);
 485                 return ERR_PTR(-EINVAL);
 486         }
 487
 488         return inode;
 489 }
 490
 491 static int calculate_inocache_hashsize(uint32_t flash_size)
 492 {
 493         /*
 494          * Pick a inocache hash size based on the size of the medium.
 495          * Count how many megabytes we're dealing with, apply a hashsize twice
 496          * that size, but rounding down to the usual big powers of 2. And keep
 497          * to sensible bounds.
 498          */
 499
 500         int size_mb = flash_size / 1024 / 1024;
 501         int hashsize = (size_mb * 2) & ~0x3f;
 502
 503         if (hashsize < INOCACHE_HASHSIZE_MIN)
 504                 return INOCACHE_HASHSIZE_MIN;
 505         if (hashsize > INOCACHE_HASHSIZE_MAX)
 506                 return INOCACHE_HASHSIZE_MAX;
 507
 508         return hashsize;
 509 }
 510
 511 int jffs2_do_fill_super(struct super_block *sb, void *data, int silent)
 512 {
 513         struct jffs2_sb_info *c;
 514         struct inode *root_i;
 515         int ret;
 516         size_t blocks;
 517
 518         c = JFFS2_SB_INFO(sb);
 519
 520         /* Do not support the MLC nand */
 521         if (c->mtd->type == MTD_MLCNANDFLASH)
 522                 return -EINVAL;
 523
 524 #ifndef CONFIG_JFFS2_FS_WRITEBUFFER
 525         if (c->mtd->type == MTD_NANDFLASH) {
 526                 pr_err("Cannot operate on NAND flash unless jffs2 NAND support is compiled in\n");
 527                 return -EINVAL;
 528         }
 529         if (c->mtd->type == MTD_DATAFLASH) {
 530                 pr_err("Cannot operate on DataFlash unless jffs2 DataFlash support is compiled in\n");
 531                 return -EINVAL;
 532         }
 533 #endif
 534
 535         c->flash_size = c->mtd->size;
 536         c->sector_size = c->mtd->erasesize;
 537         blocks = c->flash_size / c->sector_size;
 538
 539         /*
 540          * Size alignment check
 541          */
 542         if ((c->sector_size * blocks) != c->flash_size) {
 543                 c->flash_size = c->sector_size * blocks;
 544                 pr_info("Flash size not aligned to erasesize, reducing to %dKiB\n",
 545                         c->flash_size / 1024);
 546         }
 547
 548         if (c->flash_size < 5*c->sector_size) {
 549                 pr_err("Too few erase blocks (%d)\n",
 550                        c->flash_size / c->sector_size);
 551                 return -EINVAL;
 552         }
 553
 554         c->cleanmarker_size = sizeof(struct jffs2_unknown_node);
 555
 556         /* NAND (or other bizarre) flash... do setup accordingly */
 557         ret = jffs2_flash_setup(c);
 558         if (ret)
 559                 return ret;
 560
 561         c->inocache_hashsize = calculate_inocache_hashsize(c->flash_size);
 562         c->inocache_list = kcalloc(c->inocache_hashsize, sizeof(struct jffs2_inode_cache *), GFP_KERNEL);
 563         if (!c->inocache_list) {
 564                 ret = -ENOMEM;
 565                 goto out_wbuf;
 566         }
 567
 568         jffs2_init_xattr_subsystem(c);
 569
 570         if ((ret = jffs2_do_mount_fs(c)))
 571                 goto out_inohash;
 572
 573         jffs2_dbg(1, "%s(): Getting root inode\n", __func__);
 574         root_i = jffs2_iget(sb, 1);
 575         if (IS_ERR(root_i)) {
 576                 jffs2_dbg(1, "get root inode failed\n");
 577                 ret = PTR_ERR(root_i);
 578                 goto out_root;
 579         }
 580
 581         ret = -ENOMEM;
 582
 583         jffs2_dbg(1, "%s(): d_make_root()\n", __func__);
 584         sb->s_root = d_make_root(root_i);
 585         if (!sb->s_root)
 586                 goto out_root;
 587
 588         sb->s_maxbytes = 0xFFFFFFFF;
 589         sb->s_blocksize = PAGE_CACHE_SIZE;
 590         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
 591         sb->s_magic = JFFS2_SUPER_MAGIC;
 592         if (!(sb->s_flags & MS_RDONLY))
 593                 jffs2_start_garbage_collect_thread(c);
 594         return 0;
 595
 596 out_root:
 597         jffs2_free_ino_caches(c);
 598         jffs2_free_raw_node_refs(c);
 599         kvfree(c->blocks);
 600  out_inohash:
 601         jffs2_clear_xattr_subsystem(c);
 602         kfree(c->inocache_list);
 603  out_wbuf:
 604         jffs2_flash_cleanup(c);
 605
 606         return ret;
 607 }
 608
 609 void jffs2_gc_release_inode(struct jffs2_sb_info *c,
 610                                    struct jffs2_inode_info *f)
 611 {
 612         iput(OFNI_EDONI_2SFFJ(f));
 613 }
 614
 615 struct jffs2_inode_info *jffs2_gc_fetch_inode(struct jffs2_sb_info *c,
 616                                               int inum, int unlinked)
 617 {
 618         struct inode *inode;
 619         struct jffs2_inode_cache *ic;
 620
 621         if (unlinked) {
 622                 /* The inode has zero nlink but its nodes weren't yet marked
 623                    obsolete. This has to be because we're still waiting for
 624                    the final (close() and) iput() to happen.
 625
 626                    There's a possibility that the final iput() could have
 627                    happened while we were contemplating. In order to ensure
 628                    that we don't cause a new read_inode() (which would fail)
 629                    for the inode in question, we use ilookup() in this case
 630                    instead of iget().
 631
 632                    The nlink can't _become_ zero at this point because we're
 633                    holding the alloc_sem, and jffs2_do_unlink() would also
 634                    need that while decrementing nlink on any inode.
 635                 */
 636                 inode = ilookup(OFNI_BS_2SFFJ(c), inum);
 637                 if (!inode) {
 638                         jffs2_dbg(1, "ilookup() failed for ino #%u; inode is probably deleted.\n",
 639                                   inum);
 640
 641                         spin_lock(&c->inocache_lock);
 642                         ic = jffs2_get_ino_cache(c, inum);
 643                         if (!ic) {
 644                                 jffs2_dbg(1, "Inode cache for ino #%u is gone\n",
 645                                           inum);
 646                                 spin_unlock(&c->inocache_lock);
 647                                 return NULL;
 648                         }
 649                         if (ic->state != INO_STATE_CHECKEDABSENT) {
 650                                 /* Wait for progress. Don't just loop */
 651                                 jffs2_dbg(1, "Waiting for ino #%u in state %d\n",
 652                                           ic->ino, ic->state);
 653                                 sleep_on_spinunlock(&c->inocache_wq, &c->inocache_lock);
 654                         } else {
 655                                 spin_unlock(&c->inocache_lock);
 656                         }
 657
 658                         return NULL;
 659                 }
 660         } else {
 661                 /* Inode has links to it still; they're not going away because
 662                    jffs2_do_unlink() would need the alloc_sem and we have it.
 663                    Just iget() it, and if read_inode() is necessary that's OK.
 664                 */
 665                 inode = jffs2_iget(OFNI_BS_2SFFJ(c), inum);
 666                 if (IS_ERR(inode))
 667                         return ERR_CAST(inode);
 668         }
 669         if (is_bad_inode(inode)) {
 670                 pr_notice("Eep. read_inode() failed for ino #%u. unlinked %d\n",
 671                           inum, unlinked);
 672                 /* NB. This will happen again. We need to do something appropriate here. */
 673                 iput(inode);
 674                 return ERR_PTR(-EIO);
 675         }
 676
 677         return JFFS2_INODE_INFO(inode);
 678 }
 679
 680 unsigned char *jffs2_gc_fetch_page(struct jffs2_sb_info *c,
 681                                    struct jffs2_inode_info *f,
 682                                    unsigned long offset,
 683                                    unsigned long *priv)
 684 {
 685         struct inode *inode = OFNI_EDONI_2SFFJ(f);
 686         struct page *pg;
 687
 688         pg = read_cache_page(inode->i_mapping, offset >> PAGE_CACHE_SHIFT,
 689                              (void *)jffs2_do_readpage_unlock, inode);
 690         if (IS_ERR(pg))
 691                 return (void *)pg;
 692
 693         *priv = (unsigned long)pg;
 694         return kmap(pg);
 695 }
 696
 697 void jffs2_gc_release_page(struct jffs2_sb_info *c,
 698                            unsigned char *ptr,
 699                            unsigned long *priv)
 700 {
 701         struct page *pg = (void *)*priv;
 702
 703         kunmap(pg);
 704         page_cache_release(pg);
 705 }
 706
 707 static int jffs2_flash_setup(struct jffs2_sb_info *c) {
 708         int ret = 0;
 709
 710         if (jffs2_cleanmarker_oob(c)) {
 711                 /* NAND flash... do setup accordingly */
 712                 ret = jffs2_nand_flash_setup(c);
 713                 if (ret)
 714                         return ret;
 715         }
 716
 717         /* and Dataflash */
 718         if (jffs2_dataflash(c)) {
 719                 ret = jffs2_dataflash_setup(c);
 720                 if (ret)
 721                         return ret;
 722         }
 723
 724         /* and Intel "Sibley" flash */
 725         if (jffs2_nor_wbuf_flash(c)) {
 726                 ret = jffs2_nor_wbuf_flash_setup(c);
 727                 if (ret)
 728                         return ret;
 729         }
 730
 731         /* and an UBI volume */
 732         if (jffs2_ubivol(c)) {
 733                 ret = jffs2_ubivol_setup(c);
 734                 if (ret)
 735                         return ret;
 736         }
 737
 738         return ret;
 739 }
 740
 741 void jffs2_flash_cleanup(struct jffs2_sb_info *c) {
 742
 743         if (jffs2_cleanmarker_oob(c)) {
 744                 jffs2_nand_flash_cleanup(c);
 745         }
 746
 747         /* and DataFlash */
 748         if (jffs2_dataflash(c)) {
 749                 jffs2_dataflash_cleanup(c);
 750         }
 751
 752         /* and Intel "Sibley" flash */
 753         if (jffs2_nor_wbuf_flash(c)) {
 754                 jffs2_nor_wbuf_flash_cleanup(c);
 755         }
 756
 757         /* and an UBI volume */
 758         if (jffs2_ubivol(c)) {
 759                 jffs2_ubivol_cleanup(c);
 760         }
 761 }