fs/jffs2/dir.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/kernel.h>
  16 #include <linux/slab.h>
  17 #include <linux/fs.h>
  18 #include <linux/crc32.h>
  19 #include <linux/jffs2.h>
  20 #include "jffs2_fs_i.h"
  21 #include "jffs2_fs_sb.h"
  22 #include <linux/time.h>
  23 #include "nodelist.h"
  24
  25 static int jffs2_readdir (struct file *, struct dir_context *);
  26
  27 static int jffs2_create (struct inode *,struct dentry *,umode_t,
  28                          bool);
  29 static struct dentry *jffs2_lookup (struct inode *,struct dentry *,
  30                                     unsigned int);
  31 static int jffs2_link (struct dentry *,struct inode *,struct dentry *);
  32 static int jffs2_unlink (struct inode *,struct dentry *);
  33 static int jffs2_symlink (struct inode *,struct dentry *,const char *);
  34 static int jffs2_mkdir (struct inode *,struct dentry *,umode_t);
  35 static int jffs2_rmdir (struct inode *,struct dentry *);
  36 static int jffs2_mknod (struct inode *,struct dentry *,umode_t,dev_t);
  37 static int jffs2_rename (struct inode *, struct dentry *,
  38                          struct inode *, struct dentry *);
  39
  40 const struct file_operations jffs2_dir_operations =
  41 {
  42         .read =         generic_read_dir,
  43         .iterate_shared=jffs2_readdir,
  44         .unlocked_ioctl=jffs2_ioctl,
  45         .fsync =        jffs2_fsync,
  46         .llseek =       generic_file_llseek,
  47 };
  48
  49
  50 const struct inode_operations jffs2_dir_inode_operations =
  51 {
  52         .create =       jffs2_create,
  53         .lookup =       jffs2_lookup,
  54         .link =         jffs2_link,
  55         .unlink =       jffs2_unlink,
  56         .symlink =      jffs2_symlink,
  57         .mkdir =        jffs2_mkdir,
  58         .rmdir =        jffs2_rmdir,
  59         .mknod =        jffs2_mknod,
  60         .rename =       jffs2_rename,
  61         .get_acl =      jffs2_get_acl,
  62         .set_acl =      jffs2_set_acl,
  63         .setattr =      jffs2_setattr,
  64         .setxattr =     jffs2_setxattr,
  65         .getxattr =     jffs2_getxattr,
  66         .listxattr =    jffs2_listxattr,
  67         .removexattr =  jffs2_removexattr
  68 };
  69
  70 /***********************************************************************/
  71
  72
  73 /* We keep the dirent list sorted in increasing order of name hash,
  74    and we use the same hash function as the dentries. Makes this
  75    nice and simple
  76 */
  77 static struct dentry *jffs2_lookup(struct inode *dir_i, struct dentry *target,
  78                                    unsigned int flags)
  79 {
  80         struct jffs2_inode_info *dir_f;
  81         struct jffs2_full_dirent *fd = NULL, *fd_list;
  82         uint32_t ino = 0;
  83         struct inode *inode = NULL;
  84         unsigned int nhash;
  85
  86         jffs2_dbg(1, "jffs2_lookup()\n");
  87
  88         if (target->d_name.len > JFFS2_MAX_NAME_LEN)
  89                 return ERR_PTR(-ENAMETOOLONG);
  90
  91         dir_f = JFFS2_INODE_INFO(dir_i);
  92
  93         /* The 'nhash' on the fd_list is not the same as the dentry hash */
  94         nhash = full_name_hash(NULL, target->d_name.name, target->d_name.len);
  95
  96         mutex_lock(&dir_f->sem);
  97
  98         /* NB: The 2.2 backport will need to explicitly check for '.' and '..' here */
  99         for (fd_list = dir_f->dents; fd_list && fd_list->nhash <= nhash; fd_list = fd_list->next) {
 100                 if (fd_list->nhash == nhash &&
 101                     (!fd || fd_list->version > fd->version) &&
 102                     strlen(fd_list->name) == target->d_name.len &&
 103                     !strncmp(fd_list->name, target->d_name.name, target->d_name.len)) {
 104                         fd = fd_list;
 105                 }
 106         }
 107         if (fd)
 108                 ino = fd->ino;
 109         mutex_unlock(&dir_f->sem);
 110         if (ino) {
 111                 inode = jffs2_iget(dir_i->i_sb, ino);
 112                 if (IS_ERR(inode))
 113                         pr_warn("iget() failed for ino #%u\n", ino);
 114         }
 115
 116         return d_splice_alias(inode, target);
 117 }
 118
 119 /***********************************************************************/
 120
 121
 122 static int jffs2_readdir(struct file *file, struct dir_context *ctx)
 123 {
 124         struct inode *inode = file_inode(file);
 125         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
 126         struct jffs2_full_dirent *fd;
 127         unsigned long curofs = 1;
 128
 129         jffs2_dbg(1, "jffs2_readdir() for dir_i #%lu\n", inode->i_ino);
 130
 131         if (!dir_emit_dots(file, ctx))
 132                 return 0;
 133
 134         mutex_lock(&f->sem);
 135         for (fd = f->dents; fd; fd = fd->next) {
 136                 curofs++;
 137                 /* First loop: curofs = 2; pos = 2 */
 138                 if (curofs < ctx->pos) {
 139                         jffs2_dbg(2, "Skipping dirent: \"%s\", ino #%u, type %d, because curofs %ld < offset %ld\n",
 140                                   fd->name, fd->ino, fd->type, curofs, (unsigned long)ctx->pos);
 141                         continue;
 142                 }
 143                 if (!fd->ino) {
 144                         jffs2_dbg(2, "Skipping deletion dirent \"%s\"\n",
 145                                   fd->name);
 146                         ctx->pos++;
 147                         continue;
 148                 }
 149                 jffs2_dbg(2, "Dirent %ld: \"%s\", ino #%u, type %d\n",
 150                           (unsigned long)ctx->pos, fd->name, fd->ino, fd->type);
 151                 if (!dir_emit(ctx, fd->name, strlen(fd->name), fd->ino, fd->type))
 152                         break;
 153                 ctx->pos++;
 154         }
 155         mutex_unlock(&f->sem);
 156         return 0;
 157 }
 158
 159 /***********************************************************************/
 160
 161
 162 static int jffs2_create(struct inode *dir_i, struct dentry *dentry,
 163                         umode_t mode, bool excl)
 164 {
 165         struct jffs2_raw_inode *ri;
 166         struct jffs2_inode_info *f, *dir_f;
 167         struct jffs2_sb_info *c;
 168         struct inode *inode;
 169         int ret;
 170
 171         ri = jffs2_alloc_raw_inode();
 172         if (!ri)
 173                 return -ENOMEM;
 174
 175         c = JFFS2_SB_INFO(dir_i->i_sb);
 176
 177         jffs2_dbg(1, "%s()\n", __func__);
 178
 179         inode = jffs2_new_inode(dir_i, mode, ri);
 180
 181         if (IS_ERR(inode)) {
 182                 jffs2_dbg(1, "jffs2_new_inode() failed\n");
 183                 jffs2_free_raw_inode(ri);
 184                 return PTR_ERR(inode);
 185         }
 186
 187         inode->i_op = &jffs2_file_inode_operations;
 188         inode->i_fop = &jffs2_file_operations;
 189         inode->i_mapping->a_ops = &jffs2_file_address_operations;
 190         inode->i_mapping->nrpages = 0;
 191
 192         f = JFFS2_INODE_INFO(inode);
 193         dir_f = JFFS2_INODE_INFO(dir_i);
 194
 195         /* jffs2_do_create() will want to lock it, _after_ reserving
 196            space and taking c-alloc_sem. If we keep it locked here,
 197            lockdep gets unhappy (although it's a false positive;
 198            nothing else will be looking at this inode yet so there's
 199            no chance of AB-BA deadlock involving its f->sem). */
 200         mutex_unlock(&f->sem);
 201
 202         ret = jffs2_do_create(c, dir_f, f, ri, &dentry->d_name);
 203         if (ret)
 204                 goto fail;
 205
 206         dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(ri->ctime));
 207
 208         jffs2_free_raw_inode(ri);
 209
 210         jffs2_dbg(1, "%s(): Created ino #%lu with mode %o, nlink %d(%d). nrpages %ld\n",
 211                   __func__, inode->i_ino, inode->i_mode, inode->i_nlink,
 212                   f->inocache->pino_nlink, inode->i_mapping->nrpages);
 213
 214         unlock_new_inode(inode);
 215         d_instantiate(dentry, inode);
 216         return 0;
 217
 218  fail:
 219         iget_failed(inode);
 220         jffs2_free_raw_inode(ri);
 221         return ret;
 222 }
 223
 224 /***********************************************************************/
 225
 226
 227 static int jffs2_unlink(struct inode *dir_i, struct dentry *dentry)
 228 {
 229         struct jffs2_sb_info *c = JFFS2_SB_INFO(dir_i->i_sb);
 230         struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
 231         struct jffs2_inode_info *dead_f = JFFS2_INODE_INFO(d_inode(dentry));
 232         int ret;
 233         uint32_t now = get_seconds();
 234
 235         ret = jffs2_do_unlink(c, dir_f, dentry->d_name.name,
 236                               dentry->d_name.len, dead_f, now);
 237         if (dead_f->inocache)
 238                 set_nlink(d_inode(dentry), dead_f->inocache->pino_nlink);
 239         if (!ret)
 240                 dir_i->i_mtime = dir_i->i_ctime = ITIME(now);
 241         return ret;
 242 }
 243 /***********************************************************************/
 244
 245
 246 static int jffs2_link (struct dentry *old_dentry, struct inode *dir_i, struct dentry *dentry)
 247 {
 248         struct jffs2_sb_info *c = JFFS2_SB_INFO(old_dentry->d_sb);
 249         struct jffs2_inode_info *f = JFFS2_INODE_INFO(d_inode(old_dentry));
 250         struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
 251         int ret;
 252         uint8_t type;
 253         uint32_t now;
 254
 255         /* Don't let people make hard links to bad inodes. */
 256         if (!f->inocache)
 257                 return -EIO;
 258
 259         if (d_is_dir(old_dentry))
 260                 return -EPERM;
 261
 262         /* XXX: This is ugly */
 263         type = (d_inode(old_dentry)->i_mode & S_IFMT) >> 12;
 264         if (!type) type = DT_REG;
 265
 266         now = get_seconds();
 267         ret = jffs2_do_link(c, dir_f, f->inocache->ino, type, dentry->d_name.name, dentry->d_name.len, now);
 268
 269         if (!ret) {
 270                 mutex_lock(&f->sem);
 271                 set_nlink(d_inode(old_dentry), ++f->inocache->pino_nlink);
 272                 mutex_unlock(&f->sem);
 273                 d_instantiate(dentry, d_inode(old_dentry));
 274                 dir_i->i_mtime = dir_i->i_ctime = ITIME(now);
 275                 ihold(d_inode(old_dentry));
 276         }
 277         return ret;
 278 }
 279
 280 /***********************************************************************/
 281
 282 static int jffs2_symlink (struct inode *dir_i, struct dentry *dentry, const char *target)
 283 {
 284         struct jffs2_inode_info *f, *dir_f;
 285         struct jffs2_sb_info *c;
 286         struct inode *inode;
 287         struct jffs2_raw_inode *ri;
 288         struct jffs2_raw_dirent *rd;
 289         struct jffs2_full_dnode *fn;
 290         struct jffs2_full_dirent *fd;
 291         int namelen;
 292         uint32_t alloclen;
 293         int ret, targetlen = strlen(target);
 294
 295         /* FIXME: If you care. We'd need to use frags for the target
 296            if it grows much more than this */
 297         if (targetlen > 254)
 298                 return -ENAMETOOLONG;
 299
 300         ri = jffs2_alloc_raw_inode();
 301
 302         if (!ri)
 303                 return -ENOMEM;
 304
 305         c = JFFS2_SB_INFO(dir_i->i_sb);
 306
 307         /* Try to reserve enough space for both node and dirent.
 308          * Just the node will do for now, though
 309          */
 310         namelen = dentry->d_name.len;
 311         ret = jffs2_reserve_space(c, sizeof(*ri) + targetlen, &alloclen,
 312                                   ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
 313
 314         if (ret) {
 315                 jffs2_free_raw_inode(ri);
 316                 return ret;
 317         }
 318
 319         inode = jffs2_new_inode(dir_i, S_IFLNK | S_IRWXUGO, ri);
 320
 321         if (IS_ERR(inode)) {
 322                 jffs2_free_raw_inode(ri);
 323                 jffs2_complete_reservation(c);
 324                 return PTR_ERR(inode);
 325         }
 326
 327         inode->i_op = &jffs2_symlink_inode_operations;
 328
 329         f = JFFS2_INODE_INFO(inode);
 330
 331         inode->i_size = targetlen;
 332         ri->isize = ri->dsize = ri->csize = cpu_to_je32(inode->i_size);
 333         ri->totlen = cpu_to_je32(sizeof(*ri) + inode->i_size);
 334         ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
 335
 336         ri->compr = JFFS2_COMPR_NONE;
 337         ri->data_crc = cpu_to_je32(crc32(0, target, targetlen));
 338         ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
 339
 340         fn = jffs2_write_dnode(c, f, ri, target, targetlen, ALLOC_NORMAL);
 341
 342         jffs2_free_raw_inode(ri);
 343
 344         if (IS_ERR(fn)) {
 345                 /* Eeek. Wave bye bye */
 346                 mutex_unlock(&f->sem);
 347                 jffs2_complete_reservation(c);
 348                 ret = PTR_ERR(fn);
 349                 goto fail;
 350         }
 351
 352         /* We use f->target field to store the target path. */
 353         f->target = kmemdup(target, targetlen + 1, GFP_KERNEL);
 354         if (!f->target) {
 355                 pr_warn("Can't allocate %d bytes of memory\n", targetlen + 1);
 356                 mutex_unlock(&f->sem);
 357                 jffs2_complete_reservation(c);
 358                 ret = -ENOMEM;
 359                 goto fail;
 360         }
 361         inode->i_link = f->target;
 362
 363         jffs2_dbg(1, "%s(): symlink's target '%s' cached\n",
 364                   __func__, (char *)f->target);
 365
 366         /* No data here. Only a metadata node, which will be
 367            obsoleted by the first data write
 368         */
 369         f->metadata = fn;
 370         mutex_unlock(&f->sem);
 371
 372         jffs2_complete_reservation(c);
 373
 374         ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
 375         if (ret)
 376                 goto fail;
 377
 378         ret = jffs2_init_acl_post(inode);
 379         if (ret)
 380                 goto fail;
 381
 382         ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
 383                                   ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
 384         if (ret)
 385                 goto fail;
 386
 387         rd = jffs2_alloc_raw_dirent();
 388         if (!rd) {
 389                 /* Argh. Now we treat it like a normal delete */
 390                 jffs2_complete_reservation(c);
 391                 ret = -ENOMEM;
 392                 goto fail;
 393         }
 394
 395         dir_f = JFFS2_INODE_INFO(dir_i);
 396         mutex_lock(&dir_f->sem);
 397
 398         rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
 399         rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
 400         rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
 401         rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
 402
 403         rd->pino = cpu_to_je32(dir_i->i_ino);
 404         rd->version = cpu_to_je32(++dir_f->highest_version);
 405         rd->ino = cpu_to_je32(inode->i_ino);
 406         rd->mctime = cpu_to_je32(get_seconds());
 407         rd->nsize = namelen;
 408         rd->type = DT_LNK;
 409         rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
 410         rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
 411
 412         fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
 413
 414         if (IS_ERR(fd)) {
 415                 /* dirent failed to write. Delete the inode normally
 416                    as if it were the final unlink() */
 417                 jffs2_complete_reservation(c);
 418                 jffs2_free_raw_dirent(rd);
 419                 mutex_unlock(&dir_f->sem);
 420                 ret = PTR_ERR(fd);
 421                 goto fail;
 422         }
 423
 424         dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
 425
 426         jffs2_free_raw_dirent(rd);
 427
 428         /* Link the fd into the inode's list, obsoleting an old
 429            one if necessary. */
 430         jffs2_add_fd_to_list(c, fd, &dir_f->dents);
 431
 432         mutex_unlock(&dir_f->sem);
 433         jffs2_complete_reservation(c);
 434
 435         unlock_new_inode(inode);
 436         d_instantiate(dentry, inode);
 437         return 0;
 438
 439  fail:
 440         iget_failed(inode);
 441         return ret;
 442 }
 443
 444
 445 static int jffs2_mkdir (struct inode *dir_i, struct dentry *dentry, umode_t mode)
 446 {
 447         struct jffs2_inode_info *f, *dir_f;
 448         struct jffs2_sb_info *c;
 449         struct inode *inode;
 450         struct jffs2_raw_inode *ri;
 451         struct jffs2_raw_dirent *rd;
 452         struct jffs2_full_dnode *fn;
 453         struct jffs2_full_dirent *fd;
 454         int namelen;
 455         uint32_t alloclen;
 456         int ret;
 457
 458         mode |= S_IFDIR;
 459
 460         ri = jffs2_alloc_raw_inode();
 461         if (!ri)
 462                 return -ENOMEM;
 463
 464         c = JFFS2_SB_INFO(dir_i->i_sb);
 465
 466         /* Try to reserve enough space for both node and dirent.
 467          * Just the node will do for now, though
 468          */
 469         namelen = dentry->d_name.len;
 470         ret = jffs2_reserve_space(c, sizeof(*ri), &alloclen, ALLOC_NORMAL,
 471                                   JFFS2_SUMMARY_INODE_SIZE);
 472
 473         if (ret) {
 474                 jffs2_free_raw_inode(ri);
 475                 return ret;
 476         }
 477
 478         inode = jffs2_new_inode(dir_i, mode, ri);
 479
 480         if (IS_ERR(inode)) {
 481                 jffs2_free_raw_inode(ri);
 482                 jffs2_complete_reservation(c);
 483                 return PTR_ERR(inode);
 484         }
 485
 486         inode->i_op = &jffs2_dir_inode_operations;
 487         inode->i_fop = &jffs2_dir_operations;
 488
 489         f = JFFS2_INODE_INFO(inode);
 490
 491         /* Directories get nlink 2 at start */
 492         set_nlink(inode, 2);
 493         /* but ic->pino_nlink is the parent ino# */
 494         f->inocache->pino_nlink = dir_i->i_ino;
 495
 496         ri->data_crc = cpu_to_je32(0);
 497         ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
 498
 499         fn = jffs2_write_dnode(c, f, ri, NULL, 0, ALLOC_NORMAL);
 500
 501         jffs2_free_raw_inode(ri);
 502
 503         if (IS_ERR(fn)) {
 504                 /* Eeek. Wave bye bye */
 505                 mutex_unlock(&f->sem);
 506                 jffs2_complete_reservation(c);
 507                 ret = PTR_ERR(fn);
 508                 goto fail;
 509         }
 510         /* No data here. Only a metadata node, which will be
 511            obsoleted by the first data write
 512         */
 513         f->metadata = fn;
 514         mutex_unlock(&f->sem);
 515
 516         jffs2_complete_reservation(c);
 517
 518         ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
 519         if (ret)
 520                 goto fail;
 521
 522         ret = jffs2_init_acl_post(inode);
 523         if (ret)
 524                 goto fail;
 525
 526         ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
 527                                   ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
 528         if (ret)
 529                 goto fail;
 530
 531         rd = jffs2_alloc_raw_dirent();
 532         if (!rd) {
 533                 /* Argh. Now we treat it like a normal delete */
 534                 jffs2_complete_reservation(c);
 535                 ret = -ENOMEM;
 536                 goto fail;
 537         }
 538
 539         dir_f = JFFS2_INODE_INFO(dir_i);
 540         mutex_lock(&dir_f->sem);
 541
 542         rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
 543         rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
 544         rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
 545         rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
 546
 547         rd->pino = cpu_to_je32(dir_i->i_ino);
 548         rd->version = cpu_to_je32(++dir_f->highest_version);
 549         rd->ino = cpu_to_je32(inode->i_ino);
 550         rd->mctime = cpu_to_je32(get_seconds());
 551         rd->nsize = namelen;
 552         rd->type = DT_DIR;
 553         rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
 554         rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
 555
 556         fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
 557
 558         if (IS_ERR(fd)) {
 559                 /* dirent failed to write. Delete the inode normally
 560                    as if it were the final unlink() */
 561                 jffs2_complete_reservation(c);
 562                 jffs2_free_raw_dirent(rd);
 563                 mutex_unlock(&dir_f->sem);
 564                 ret = PTR_ERR(fd);
 565                 goto fail;
 566         }
 567
 568         dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
 569         inc_nlink(dir_i);
 570
 571         jffs2_free_raw_dirent(rd);
 572
 573         /* Link the fd into the inode's list, obsoleting an old
 574            one if necessary. */
 575         jffs2_add_fd_to_list(c, fd, &dir_f->dents);
 576
 577         mutex_unlock(&dir_f->sem);
 578         jffs2_complete_reservation(c);
 579
 580         unlock_new_inode(inode);
 581         d_instantiate(dentry, inode);
 582         return 0;
 583
 584  fail:
 585         iget_failed(inode);
 586         return ret;
 587 }
 588
 589 static int jffs2_rmdir (struct inode *dir_i, struct dentry *dentry)
 590 {
 591         struct jffs2_sb_info *c = JFFS2_SB_INFO(dir_i->i_sb);
 592         struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
 593         struct jffs2_inode_info *f = JFFS2_INODE_INFO(d_inode(dentry));
 594         struct jffs2_full_dirent *fd;
 595         int ret;
 596         uint32_t now = get_seconds();
 597
 598         for (fd = f->dents ; fd; fd = fd->next) {
 599                 if (fd->ino)
 600                         return -ENOTEMPTY;
 601         }
 602
 603         ret = jffs2_do_unlink(c, dir_f, dentry->d_name.name,
 604                               dentry->d_name.len, f, now);
 605         if (!ret) {
 606                 dir_i->i_mtime = dir_i->i_ctime = ITIME(now);
 607                 clear_nlink(d_inode(dentry));
 608                 drop_nlink(dir_i);
 609         }
 610         return ret;
 611 }
 612
 613 static int jffs2_mknod (struct inode *dir_i, struct dentry *dentry, umode_t mode, dev_t rdev)
 614 {
 615         struct jffs2_inode_info *f, *dir_f;
 616         struct jffs2_sb_info *c;
 617         struct inode *inode;
 618         struct jffs2_raw_inode *ri;
 619         struct jffs2_raw_dirent *rd;
 620         struct jffs2_full_dnode *fn;
 621         struct jffs2_full_dirent *fd;
 622         int namelen;
 623         union jffs2_device_node dev;
 624         int devlen = 0;
 625         uint32_t alloclen;
 626         int ret;
 627
 628         ri = jffs2_alloc_raw_inode();
 629         if (!ri)
 630                 return -ENOMEM;
 631
 632         c = JFFS2_SB_INFO(dir_i->i_sb);
 633
 634         if (S_ISBLK(mode) || S_ISCHR(mode))
 635                 devlen = jffs2_encode_dev(&dev, rdev);
 636
 637         /* Try to reserve enough space for both node and dirent.
 638          * Just the node will do for now, though
 639          */
 640         namelen = dentry->d_name.len;
 641         ret = jffs2_reserve_space(c, sizeof(*ri) + devlen, &alloclen,
 642                                   ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
 643
 644         if (ret) {
 645                 jffs2_free_raw_inode(ri);
 646                 return ret;
 647         }
 648
 649         inode = jffs2_new_inode(dir_i, mode, ri);
 650
 651         if (IS_ERR(inode)) {
 652                 jffs2_free_raw_inode(ri);
 653                 jffs2_complete_reservation(c);
 654                 return PTR_ERR(inode);
 655         }
 656         inode->i_op = &jffs2_file_inode_operations;
 657         init_special_inode(inode, inode->i_mode, rdev);
 658
 659         f = JFFS2_INODE_INFO(inode);
 660
 661         ri->dsize = ri->csize = cpu_to_je32(devlen);
 662         ri->totlen = cpu_to_je32(sizeof(*ri) + devlen);
 663         ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
 664
 665         ri->compr = JFFS2_COMPR_NONE;
 666         ri->data_crc = cpu_to_je32(crc32(0, &dev, devlen));
 667         ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
 668
 669         fn = jffs2_write_dnode(c, f, ri, (char *)&dev, devlen, ALLOC_NORMAL);
 670
 671         jffs2_free_raw_inode(ri);
 672
 673         if (IS_ERR(fn)) {
 674                 /* Eeek. Wave bye bye */
 675                 mutex_unlock(&f->sem);
 676                 jffs2_complete_reservation(c);
 677                 ret = PTR_ERR(fn);
 678                 goto fail;
 679         }
 680         /* No data here. Only a metadata node, which will be
 681            obsoleted by the first data write
 682         */
 683         f->metadata = fn;
 684         mutex_unlock(&f->sem);
 685
 686         jffs2_complete_reservation(c);
 687
 688         ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
 689         if (ret)
 690                 goto fail;
 691
 692         ret = jffs2_init_acl_post(inode);
 693         if (ret)
 694                 goto fail;
 695
 696         ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
 697                                   ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
 698         if (ret)
 699                 goto fail;
 700
 701         rd = jffs2_alloc_raw_dirent();
 702         if (!rd) {
 703                 /* Argh. Now we treat it like a normal delete */
 704                 jffs2_complete_reservation(c);
 705                 ret = -ENOMEM;
 706                 goto fail;
 707         }
 708
 709         dir_f = JFFS2_INODE_INFO(dir_i);
 710         mutex_lock(&dir_f->sem);
 711
 712         rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
 713         rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
 714         rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
 715         rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
 716
 717         rd->pino = cpu_to_je32(dir_i->i_ino);
 718         rd->version = cpu_to_je32(++dir_f->highest_version);
 719         rd->ino = cpu_to_je32(inode->i_ino);
 720         rd->mctime = cpu_to_je32(get_seconds());
 721         rd->nsize = namelen;
 722
 723         /* XXX: This is ugly. */
 724         rd->type = (mode & S_IFMT) >> 12;
 725
 726         rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
 727         rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
 728
 729         fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
 730
 731         if (IS_ERR(fd)) {
 732                 /* dirent failed to write. Delete the inode normally
 733                    as if it were the final unlink() */
 734                 jffs2_complete_reservation(c);
 735                 jffs2_free_raw_dirent(rd);
 736                 mutex_unlock(&dir_f->sem);
 737                 ret = PTR_ERR(fd);
 738                 goto fail;
 739         }
 740
 741         dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
 742
 743         jffs2_free_raw_dirent(rd);
 744
 745         /* Link the fd into the inode's list, obsoleting an old
 746            one if necessary. */
 747         jffs2_add_fd_to_list(c, fd, &dir_f->dents);
 748
 749         mutex_unlock(&dir_f->sem);
 750         jffs2_complete_reservation(c);
 751
 752         unlock_new_inode(inode);
 753         d_instantiate(dentry, inode);
 754         return 0;
 755
 756  fail:
 757         iget_failed(inode);
 758         return ret;
 759 }
 760
 761 static int jffs2_rename (struct inode *old_dir_i, struct dentry *old_dentry,
 762                          struct inode *new_dir_i, struct dentry *new_dentry)
 763 {
 764         int ret;
 765         struct jffs2_sb_info *c = JFFS2_SB_INFO(old_dir_i->i_sb);
 766         struct jffs2_inode_info *victim_f = NULL;
 767         uint8_t type;
 768         uint32_t now;
 769
 770         /* The VFS will check for us and prevent trying to rename a
 771          * file over a directory and vice versa, but if it's a directory,
 772          * the VFS can't check whether the victim is empty. The filesystem
 773          * needs to do that for itself.
 774          */
 775         if (d_really_is_positive(new_dentry)) {
 776                 victim_f = JFFS2_INODE_INFO(d_inode(new_dentry));
 777                 if (d_is_dir(new_dentry)) {
 778                         struct jffs2_full_dirent *fd;
 779
 780                         mutex_lock(&victim_f->sem);
 781                         for (fd = victim_f->dents; fd; fd = fd->next) {
 782                                 if (fd->ino) {
 783                                         mutex_unlock(&victim_f->sem);
 784                                         return -ENOTEMPTY;
 785                                 }
 786                         }
 787                         mutex_unlock(&victim_f->sem);
 788                 }
 789         }
 790
 791         /* XXX: We probably ought to alloc enough space for
 792            both nodes at the same time. Writing the new link,
 793            then getting -ENOSPC, is quite bad :)
 794         */
 795
 796         /* Make a hard link */
 797
 798         /* XXX: This is ugly */
 799         type = (d_inode(old_dentry)->i_mode & S_IFMT) >> 12;
 800         if (!type) type = DT_REG;
 801
 802         now = get_seconds();
 803         ret = jffs2_do_link(c, JFFS2_INODE_INFO(new_dir_i),
 804                             d_inode(old_dentry)->i_ino, type,
 805                             new_dentry->d_name.name, new_dentry->d_name.len, now);
 806
 807         if (ret)
 808                 return ret;
 809
 810         if (victim_f) {
 811                 /* There was a victim. Kill it off nicely */
 812                 if (d_is_dir(new_dentry))
 813                         clear_nlink(d_inode(new_dentry));
 814                 else
 815                         drop_nlink(d_inode(new_dentry));
 816                 /* Don't oops if the victim was a dirent pointing to an
 817                    inode which didn't exist. */
 818                 if (victim_f->inocache) {
 819                         mutex_lock(&victim_f->sem);
 820                         if (d_is_dir(new_dentry))
 821                                 victim_f->inocache->pino_nlink = 0;
 822                         else
 823                                 victim_f->inocache->pino_nlink--;
 824                         mutex_unlock(&victim_f->sem);
 825                 }
 826         }
 827
 828         /* If it was a directory we moved, and there was no victim,
 829            increase i_nlink on its new parent */
 830         if (d_is_dir(old_dentry) && !victim_f)
 831                 inc_nlink(new_dir_i);
 832
 833         /* Unlink the original */
 834         ret = jffs2_do_unlink(c, JFFS2_INODE_INFO(old_dir_i),
 835                               old_dentry->d_name.name, old_dentry->d_name.len, NULL, now);
 836
 837         /* We don't touch inode->i_nlink */
 838
 839         if (ret) {
 840                 /* Oh shit. We really ought to make a single node which can do both atomically */
 841                 struct jffs2_inode_info *f = JFFS2_INODE_INFO(d_inode(old_dentry));
 842                 mutex_lock(&f->sem);
 843                 inc_nlink(d_inode(old_dentry));
 844                 if (f->inocache && !d_is_dir(old_dentry))
 845                         f->inocache->pino_nlink++;
 846                 mutex_unlock(&f->sem);
 847
 848                 pr_notice("%s(): Link succeeded, unlink failed (err %d). You now have a hard link\n",
 849                           __func__, ret);
 850                 /*
 851                  * We can't keep the target in dcache after that.
 852                  * For one thing, we can't afford dentry aliases for directories.
 853                  * For another, if there was a victim, we _can't_ set new inode
 854                  * for that sucker and we have to trigger mount eviction - the
 855                  * caller won't do it on its own since we are returning an error.
 856                  */
 857                 d_invalidate(new_dentry);
 858                 new_dir_i->i_mtime = new_dir_i->i_ctime = ITIME(now);
 859                 return ret;
 860         }
 861
 862         if (d_is_dir(old_dentry))
 863                 drop_nlink(old_dir_i);
 864
 865         new_dir_i->i_mtime = new_dir_i->i_ctime = old_dir_i->i_mtime = old_dir_i->i_ctime = ITIME(now);
 866
 867         return 0;
 868 }
 869