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                          unsigned int);
  40
  41 const struct file_operations jffs2_dir_operations =
  42 {
  43         .read =         generic_read_dir,
  44         .iterate_shared=jffs2_readdir,
  45         .unlocked_ioctl=jffs2_ioctl,
  46         .fsync =        jffs2_fsync,
  47         .llseek =       generic_file_llseek,
  48 };
  49
  50
  51 const struct inode_operations jffs2_dir_inode_operations =
  52 {
  53         .create =       jffs2_create,
  54         .lookup =       jffs2_lookup,
  55         .link =         jffs2_link,
  56         .unlink =       jffs2_unlink,
  57         .symlink =      jffs2_symlink,
  58         .mkdir =        jffs2_mkdir,
  59         .rmdir =        jffs2_rmdir,
  60         .mknod =        jffs2_mknod,
  61         .rename =       jffs2_rename,
  62         .get_acl =      jffs2_get_acl,
  63         .set_acl =      jffs2_set_acl,
  64         .setattr =      jffs2_setattr,
  65         .setxattr =     jffs2_setxattr,
  66         .getxattr =     jffs2_getxattr,
  67         .listxattr =    jffs2_listxattr,
  68         .removexattr =  jffs2_removexattr
  69 };
  70
  71 /***********************************************************************/
  72
  73
  74 /* We keep the dirent list sorted in increasing order of name hash,
  75    and we use the same hash function as the dentries. Makes this
  76    nice and simple
  77 */
  78 static struct dentry *jffs2_lookup(struct inode *dir_i, struct dentry *target,
  79                                    unsigned int flags)
  80 {
  81         struct jffs2_inode_info *dir_f;
  82         struct jffs2_full_dirent *fd = NULL, *fd_list;
  83         uint32_t ino = 0;
  84         struct inode *inode = NULL;
  85         unsigned int nhash;
  86
  87         jffs2_dbg(1, "jffs2_lookup()\n");
  88
  89         if (target->d_name.len > JFFS2_MAX_NAME_LEN)
  90                 return ERR_PTR(-ENAMETOOLONG);
  91
  92         dir_f = JFFS2_INODE_INFO(dir_i);
  93
  94         /* The 'nhash' on the fd_list is not the same as the dentry hash */
  95         nhash = full_name_hash(NULL, target->d_name.name, target->d_name.len);
  96
  97         mutex_lock(&dir_f->sem);
  98
  99         /* NB: The 2.2 backport will need to explicitly check for '.' and '..' here */
 100         for (fd_list = dir_f->dents; fd_list && fd_list->nhash <= nhash; fd_list = fd_list->next) {
 101                 if (fd_list->nhash == nhash &&
 102                     (!fd || fd_list->version > fd->version) &&
 103                     strlen(fd_list->name) == target->d_name.len &&
 104                     !strncmp(fd_list->name, target->d_name.name, target->d_name.len)) {
 105                         fd = fd_list;
 106                 }
 107         }
 108         if (fd)
 109                 ino = fd->ino;
 110         mutex_unlock(&dir_f->sem);
 111         if (ino) {
 112                 inode = jffs2_iget(dir_i->i_sb, ino);
 113                 if (IS_ERR(inode))
 114                         pr_warn("iget() failed for ino #%u\n", ino);
 115         }
 116
 117         return d_splice_alias(inode, target);
 118 }
 119
 120 /***********************************************************************/
 121
 122
 123 static int jffs2_readdir(struct file *file, struct dir_context *ctx)
 124 {
 125         struct inode *inode = file_inode(file);
 126         struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
 127         struct jffs2_full_dirent *fd;
 128         unsigned long curofs = 1;
 129
 130         jffs2_dbg(1, "jffs2_readdir() for dir_i #%lu\n", inode->i_ino);
 131
 132         if (!dir_emit_dots(file, ctx))
 133                 return 0;
 134
 135         mutex_lock(&f->sem);
 136         for (fd = f->dents; fd; fd = fd->next) {
 137                 curofs++;
 138                 /* First loop: curofs = 2; pos = 2 */
 139                 if (curofs < ctx->pos) {
 140                         jffs2_dbg(2, "Skipping dirent: \"%s\", ino #%u, type %d, because curofs %ld < offset %ld\n",
 141                                   fd->name, fd->ino, fd->type, curofs, (unsigned long)ctx->pos);
 142                         continue;
 143                 }
 144                 if (!fd->ino) {
 145                         jffs2_dbg(2, "Skipping deletion dirent \"%s\"\n",
 146                                   fd->name);
 147                         ctx->pos++;
 148                         continue;
 149                 }
 150                 jffs2_dbg(2, "Dirent %ld: \"%s\", ino #%u, type %d\n",
 151                           (unsigned long)ctx->pos, fd->name, fd->ino, fd->type);
 152                 if (!dir_emit(ctx, fd->name, strlen(fd->name), fd->ino, fd->type))
 153                         break;
 154                 ctx->pos++;
 155         }
 156         mutex_unlock(&f->sem);
 157         return 0;
 158 }
 159
 160 /***********************************************************************/
 161
 162
 163 static int jffs2_create(struct inode *dir_i, struct dentry *dentry,
 164                         umode_t mode, bool excl)
 165 {
 166         struct jffs2_raw_inode *ri;
 167         struct jffs2_inode_info *f, *dir_f;
 168         struct jffs2_sb_info *c;
 169         struct inode *inode;
 170         int ret;
 171
 172         ri = jffs2_alloc_raw_inode();
 173         if (!ri)
 174                 return -ENOMEM;
 175
 176         c = JFFS2_SB_INFO(dir_i->i_sb);
 177
 178         jffs2_dbg(1, "%s()\n", __func__);
 179
 180         inode = jffs2_new_inode(dir_i, mode, ri);
 181
 182         if (IS_ERR(inode)) {
 183                 jffs2_dbg(1, "jffs2_new_inode() failed\n");
 184                 jffs2_free_raw_inode(ri);
 185                 return PTR_ERR(inode);
 186         }
 187
 188         inode->i_op = &jffs2_file_inode_operations;
 189         inode->i_fop = &jffs2_file_operations;
 190         inode->i_mapping->a_ops = &jffs2_file_address_operations;
 191         inode->i_mapping->nrpages = 0;
 192
 193         f = JFFS2_INODE_INFO(inode);
 194         dir_f = JFFS2_INODE_INFO(dir_i);
 195
 196         /* jffs2_do_create() will want to lock it, _after_ reserving
 197            space and taking c-alloc_sem. If we keep it locked here,
 198            lockdep gets unhappy (although it's a false positive;
 199            nothing else will be looking at this inode yet so there's
 200            no chance of AB-BA deadlock involving its f->sem). */
 201         mutex_unlock(&f->sem);
 202
 203         ret = jffs2_do_create(c, dir_f, f, ri, &dentry->d_name);
 204         if (ret)
 205                 goto fail;
 206
 207         dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(ri->ctime));
 208
 209         jffs2_free_raw_inode(ri);
 210
 211         jffs2_dbg(1, "%s(): Created ino #%lu with mode %o, nlink %d(%d). nrpages %ld\n",
 212                   __func__, inode->i_ino, inode->i_mode, inode->i_nlink,
 213                   f->inocache->pino_nlink, inode->i_mapping->nrpages);
 214
 215         unlock_new_inode(inode);
 216         d_instantiate(dentry, inode);
 217         return 0;
 218
 219  fail:
 220         iget_failed(inode);
 221         jffs2_free_raw_inode(ri);
 222         return ret;
 223 }
 224
 225 /***********************************************************************/
 226
 227
 228 static int jffs2_unlink(struct inode *dir_i, struct dentry *dentry)
 229 {
 230         struct jffs2_sb_info *c = JFFS2_SB_INFO(dir_i->i_sb);
 231         struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
 232         struct jffs2_inode_info *dead_f = JFFS2_INODE_INFO(d_inode(dentry));
 233         int ret;
 234         uint32_t now = get_seconds();
 235
 236         ret = jffs2_do_unlink(c, dir_f, dentry->d_name.name,
 237                               dentry->d_name.len, dead_f, now);
 238         if (dead_f->inocache)
 239                 set_nlink(d_inode(dentry), dead_f->inocache->pino_nlink);
 240         if (!ret)
 241                 dir_i->i_mtime = dir_i->i_ctime = ITIME(now);
 242         return ret;
 243 }
 244 /***********************************************************************/
 245
 246
 247 static int jffs2_link (struct dentry *old_dentry, struct inode *dir_i, struct dentry *dentry)
 248 {
 249         struct jffs2_sb_info *c = JFFS2_SB_INFO(old_dentry->d_sb);
 250         struct jffs2_inode_info *f = JFFS2_INODE_INFO(d_inode(old_dentry));
 251         struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
 252         int ret;
 253         uint8_t type;
 254         uint32_t now;
 255
 256         /* Don't let people make hard links to bad inodes. */
 257         if (!f->inocache)
 258                 return -EIO;
 259
 260         if (d_is_dir(old_dentry))
 261                 return -EPERM;
 262
 263         /* XXX: This is ugly */
 264         type = (d_inode(old_dentry)->i_mode & S_IFMT) >> 12;
 265         if (!type) type = DT_REG;
 266
 267         now = get_seconds();
 268         ret = jffs2_do_link(c, dir_f, f->inocache->ino, type, dentry->d_name.name, dentry->d_name.len, now);
 269
 270         if (!ret) {
 271                 mutex_lock(&f->sem);
 272                 set_nlink(d_inode(old_dentry), ++f->inocache->pino_nlink);
 273                 mutex_unlock(&f->sem);
 274                 d_instantiate(dentry, d_inode(old_dentry));
 275                 dir_i->i_mtime = dir_i->i_ctime = ITIME(now);
 276                 ihold(d_inode(old_dentry));
 277         }
 278         return ret;
 279 }
 280
 281 /***********************************************************************/
 282
 283 static int jffs2_symlink (struct inode *dir_i, struct dentry *dentry, const char *target)
 284 {
 285         struct jffs2_inode_info *f, *dir_f;
 286         struct jffs2_sb_info *c;
 287         struct inode *inode;
 288         struct jffs2_raw_inode *ri;
 289         struct jffs2_raw_dirent *rd;
 290         struct jffs2_full_dnode *fn;
 291         struct jffs2_full_dirent *fd;
 292         int namelen;
 293         uint32_t alloclen;
 294         int ret, targetlen = strlen(target);
 295
 296         /* FIXME: If you care. We'd need to use frags for the target
 297            if it grows much more than this */
 298         if (targetlen > 254)
 299                 return -ENAMETOOLONG;
 300
 301         ri = jffs2_alloc_raw_inode();
 302
 303         if (!ri)
 304                 return -ENOMEM;
 305
 306         c = JFFS2_SB_INFO(dir_i->i_sb);
 307
 308         /* Try to reserve enough space for both node and dirent.
 309          * Just the node will do for now, though
 310          */
 311         namelen = dentry->d_name.len;
 312         ret = jffs2_reserve_space(c, sizeof(*ri) + targetlen, &alloclen,
 313                                   ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
 314
 315         if (ret) {
 316                 jffs2_free_raw_inode(ri);
 317                 return ret;
 318         }
 319
 320         inode = jffs2_new_inode(dir_i, S_IFLNK | S_IRWXUGO, ri);
 321
 322         if (IS_ERR(inode)) {
 323                 jffs2_free_raw_inode(ri);
 324                 jffs2_complete_reservation(c);
 325                 return PTR_ERR(inode);
 326         }
 327
 328         inode->i_op = &jffs2_symlink_inode_operations;
 329
 330         f = JFFS2_INODE_INFO(inode);
 331
 332         inode->i_size = targetlen;
 333         ri->isize = ri->dsize = ri->csize = cpu_to_je32(inode->i_size);
 334         ri->totlen = cpu_to_je32(sizeof(*ri) + inode->i_size);
 335         ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
 336
 337         ri->compr = JFFS2_COMPR_NONE;
 338         ri->data_crc = cpu_to_je32(crc32(0, target, targetlen));
 339         ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
 340
 341         fn = jffs2_write_dnode(c, f, ri, target, targetlen, ALLOC_NORMAL);
 342
 343         jffs2_free_raw_inode(ri);
 344
 345         if (IS_ERR(fn)) {
 346                 /* Eeek. Wave bye bye */
 347                 mutex_unlock(&f->sem);
 348                 jffs2_complete_reservation(c);
 349                 ret = PTR_ERR(fn);
 350                 goto fail;
 351         }
 352
 353         /* We use f->target field to store the target path. */
 354         f->target = kmemdup(target, targetlen + 1, GFP_KERNEL);
 355         if (!f->target) {
 356                 pr_warn("Can't allocate %d bytes of memory\n", targetlen + 1);
 357                 mutex_unlock(&f->sem);
 358                 jffs2_complete_reservation(c);
 359                 ret = -ENOMEM;
 360                 goto fail;
 361         }
 362         inode->i_link = f->target;
 363
 364         jffs2_dbg(1, "%s(): symlink's target '%s' cached\n",
 365                   __func__, (char *)f->target);
 366
 367         /* No data here. Only a metadata node, which will be
 368            obsoleted by the first data write
 369         */
 370         f->metadata = fn;
 371         mutex_unlock(&f->sem);
 372
 373         jffs2_complete_reservation(c);
 374
 375         ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
 376         if (ret)
 377                 goto fail;
 378
 379         ret = jffs2_init_acl_post(inode);
 380         if (ret)
 381                 goto fail;
 382
 383         ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
 384                                   ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
 385         if (ret)
 386                 goto fail;
 387
 388         rd = jffs2_alloc_raw_dirent();
 389         if (!rd) {
 390                 /* Argh. Now we treat it like a normal delete */
 391                 jffs2_complete_reservation(c);
 392                 ret = -ENOMEM;
 393                 goto fail;
 394         }
 395
 396         dir_f = JFFS2_INODE_INFO(dir_i);
 397         mutex_lock(&dir_f->sem);
 398
 399         rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
 400         rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
 401         rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
 402         rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
 403
 404         rd->pino = cpu_to_je32(dir_i->i_ino);
 405         rd->version = cpu_to_je32(++dir_f->highest_version);
 406         rd->ino = cpu_to_je32(inode->i_ino);
 407         rd->mctime = cpu_to_je32(get_seconds());
 408         rd->nsize = namelen;
 409         rd->type = DT_LNK;
 410         rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
 411         rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
 412
 413         fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
 414
 415         if (IS_ERR(fd)) {
 416                 /* dirent failed to write. Delete the inode normally
 417                    as if it were the final unlink() */
 418                 jffs2_complete_reservation(c);
 419                 jffs2_free_raw_dirent(rd);
 420                 mutex_unlock(&dir_f->sem);
 421                 ret = PTR_ERR(fd);
 422                 goto fail;
 423         }
 424
 425         dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
 426
 427         jffs2_free_raw_dirent(rd);
 428
 429         /* Link the fd into the inode's list, obsoleting an old
 430            one if necessary. */
 431         jffs2_add_fd_to_list(c, fd, &dir_f->dents);
 432
 433         mutex_unlock(&dir_f->sem);
 434         jffs2_complete_reservation(c);
 435
 436         unlock_new_inode(inode);
 437         d_instantiate(dentry, inode);
 438         return 0;
 439
 440  fail:
 441         iget_failed(inode);
 442         return ret;
 443 }
 444
 445
 446 static int jffs2_mkdir (struct inode *dir_i, struct dentry *dentry, umode_t mode)
 447 {
 448         struct jffs2_inode_info *f, *dir_f;
 449         struct jffs2_sb_info *c;
 450         struct inode *inode;
 451         struct jffs2_raw_inode *ri;
 452         struct jffs2_raw_dirent *rd;
 453         struct jffs2_full_dnode *fn;
 454         struct jffs2_full_dirent *fd;
 455         int namelen;
 456         uint32_t alloclen;
 457         int ret;
 458
 459         mode |= S_IFDIR;
 460
 461         ri = jffs2_alloc_raw_inode();
 462         if (!ri)
 463                 return -ENOMEM;
 464
 465         c = JFFS2_SB_INFO(dir_i->i_sb);
 466
 467         /* Try to reserve enough space for both node and dirent.
 468          * Just the node will do for now, though
 469          */
 470         namelen = dentry->d_name.len;
 471         ret = jffs2_reserve_space(c, sizeof(*ri), &alloclen, ALLOC_NORMAL,
 472                                   JFFS2_SUMMARY_INODE_SIZE);
 473
 474         if (ret) {
 475                 jffs2_free_raw_inode(ri);
 476                 return ret;
 477         }
 478
 479         inode = jffs2_new_inode(dir_i, mode, ri);
 480
 481         if (IS_ERR(inode)) {
 482                 jffs2_free_raw_inode(ri);
 483                 jffs2_complete_reservation(c);
 484                 return PTR_ERR(inode);
 485         }
 486
 487         inode->i_op = &jffs2_dir_inode_operations;
 488         inode->i_fop = &jffs2_dir_operations;
 489
 490         f = JFFS2_INODE_INFO(inode);
 491
 492         /* Directories get nlink 2 at start */
 493         set_nlink(inode, 2);
 494         /* but ic->pino_nlink is the parent ino# */
 495         f->inocache->pino_nlink = dir_i->i_ino;
 496
 497         ri->data_crc = cpu_to_je32(0);
 498         ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
 499
 500         fn = jffs2_write_dnode(c, f, ri, NULL, 0, ALLOC_NORMAL);
 501
 502         jffs2_free_raw_inode(ri);
 503
 504         if (IS_ERR(fn)) {
 505                 /* Eeek. Wave bye bye */
 506                 mutex_unlock(&f->sem);
 507                 jffs2_complete_reservation(c);
 508                 ret = PTR_ERR(fn);
 509                 goto fail;
 510         }
 511         /* No data here. Only a metadata node, which will be
 512            obsoleted by the first data write
 513         */
 514         f->metadata = fn;
 515         mutex_unlock(&f->sem);
 516
 517         jffs2_complete_reservation(c);
 518
 519         ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
 520         if (ret)
 521                 goto fail;
 522
 523         ret = jffs2_init_acl_post(inode);
 524         if (ret)
 525                 goto fail;
 526
 527         ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
 528                                   ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
 529         if (ret)
 530                 goto fail;
 531
 532         rd = jffs2_alloc_raw_dirent();
 533         if (!rd) {
 534                 /* Argh. Now we treat it like a normal delete */
 535                 jffs2_complete_reservation(c);
 536                 ret = -ENOMEM;
 537                 goto fail;
 538         }
 539
 540         dir_f = JFFS2_INODE_INFO(dir_i);
 541         mutex_lock(&dir_f->sem);
 542
 543         rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
 544         rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
 545         rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
 546         rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
 547
 548         rd->pino = cpu_to_je32(dir_i->i_ino);
 549         rd->version = cpu_to_je32(++dir_f->highest_version);
 550         rd->ino = cpu_to_je32(inode->i_ino);
 551         rd->mctime = cpu_to_je32(get_seconds());
 552         rd->nsize = namelen;
 553         rd->type = DT_DIR;
 554         rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
 555         rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
 556
 557         fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
 558
 559         if (IS_ERR(fd)) {
 560                 /* dirent failed to write. Delete the inode normally
 561                    as if it were the final unlink() */
 562                 jffs2_complete_reservation(c);
 563                 jffs2_free_raw_dirent(rd);
 564                 mutex_unlock(&dir_f->sem);
 565                 ret = PTR_ERR(fd);
 566                 goto fail;
 567         }
 568
 569         dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
 570         inc_nlink(dir_i);
 571
 572         jffs2_free_raw_dirent(rd);
 573
 574         /* Link the fd into the inode's list, obsoleting an old
 575            one if necessary. */
 576         jffs2_add_fd_to_list(c, fd, &dir_f->dents);
 577
 578         mutex_unlock(&dir_f->sem);
 579         jffs2_complete_reservation(c);
 580
 581         unlock_new_inode(inode);
 582         d_instantiate(dentry, inode);
 583         return 0;
 584
 585  fail:
 586         iget_failed(inode);
 587         return ret;
 588 }
 589
 590 static int jffs2_rmdir (struct inode *dir_i, struct dentry *dentry)
 591 {
 592         struct jffs2_sb_info *c = JFFS2_SB_INFO(dir_i->i_sb);
 593         struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
 594         struct jffs2_inode_info *f = JFFS2_INODE_INFO(d_inode(dentry));
 595         struct jffs2_full_dirent *fd;
 596         int ret;
 597         uint32_t now = get_seconds();
 598
 599         for (fd = f->dents ; fd; fd = fd->next) {
 600                 if (fd->ino)
 601                         return -ENOTEMPTY;
 602         }
 603
 604         ret = jffs2_do_unlink(c, dir_f, dentry->d_name.name,
 605                               dentry->d_name.len, f, now);
 606         if (!ret) {
 607                 dir_i->i_mtime = dir_i->i_ctime = ITIME(now);
 608                 clear_nlink(d_inode(dentry));
 609                 drop_nlink(dir_i);
 610         }
 611         return ret;
 612 }
 613
 614 static int jffs2_mknod (struct inode *dir_i, struct dentry *dentry, umode_t mode, dev_t rdev)
 615 {
 616         struct jffs2_inode_info *f, *dir_f;
 617         struct jffs2_sb_info *c;
 618         struct inode *inode;
 619         struct jffs2_raw_inode *ri;
 620         struct jffs2_raw_dirent *rd;
 621         struct jffs2_full_dnode *fn;
 622         struct jffs2_full_dirent *fd;
 623         int namelen;
 624         union jffs2_device_node dev;
 625         int devlen = 0;
 626         uint32_t alloclen;
 627         int ret;
 628
 629         ri = jffs2_alloc_raw_inode();
 630         if (!ri)
 631                 return -ENOMEM;
 632
 633         c = JFFS2_SB_INFO(dir_i->i_sb);
 634
 635         if (S_ISBLK(mode) || S_ISCHR(mode))
 636                 devlen = jffs2_encode_dev(&dev, rdev);
 637
 638         /* Try to reserve enough space for both node and dirent.
 639          * Just the node will do for now, though
 640          */
 641         namelen = dentry->d_name.len;
 642         ret = jffs2_reserve_space(c, sizeof(*ri) + devlen, &alloclen,
 643                                   ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
 644
 645         if (ret) {
 646                 jffs2_free_raw_inode(ri);
 647                 return ret;
 648         }
 649
 650         inode = jffs2_new_inode(dir_i, mode, ri);
 651
 652         if (IS_ERR(inode)) {
 653                 jffs2_free_raw_inode(ri);
 654                 jffs2_complete_reservation(c);
 655                 return PTR_ERR(inode);
 656         }
 657         inode->i_op = &jffs2_file_inode_operations;
 658         init_special_inode(inode, inode->i_mode, rdev);
 659
 660         f = JFFS2_INODE_INFO(inode);
 661
 662         ri->dsize = ri->csize = cpu_to_je32(devlen);
 663         ri->totlen = cpu_to_je32(sizeof(*ri) + devlen);
 664         ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
 665
 666         ri->compr = JFFS2_COMPR_NONE;
 667         ri->data_crc = cpu_to_je32(crc32(0, &dev, devlen));
 668         ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
 669
 670         fn = jffs2_write_dnode(c, f, ri, (char *)&dev, devlen, ALLOC_NORMAL);
 671
 672         jffs2_free_raw_inode(ri);
 673
 674         if (IS_ERR(fn)) {
 675                 /* Eeek. Wave bye bye */
 676                 mutex_unlock(&f->sem);
 677                 jffs2_complete_reservation(c);
 678                 ret = PTR_ERR(fn);
 679                 goto fail;
 680         }
 681         /* No data here. Only a metadata node, which will be
 682            obsoleted by the first data write
 683         */
 684         f->metadata = fn;
 685         mutex_unlock(&f->sem);
 686
 687         jffs2_complete_reservation(c);
 688
 689         ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
 690         if (ret)
 691                 goto fail;
 692
 693         ret = jffs2_init_acl_post(inode);
 694         if (ret)
 695                 goto fail;
 696
 697         ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
 698                                   ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
 699         if (ret)
 700                 goto fail;
 701
 702         rd = jffs2_alloc_raw_dirent();
 703         if (!rd) {
 704                 /* Argh. Now we treat it like a normal delete */
 705                 jffs2_complete_reservation(c);
 706                 ret = -ENOMEM;
 707                 goto fail;
 708         }
 709
 710         dir_f = JFFS2_INODE_INFO(dir_i);
 711         mutex_lock(&dir_f->sem);
 712
 713         rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
 714         rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
 715         rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
 716         rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
 717
 718         rd->pino = cpu_to_je32(dir_i->i_ino);
 719         rd->version = cpu_to_je32(++dir_f->highest_version);
 720         rd->ino = cpu_to_je32(inode->i_ino);
 721         rd->mctime = cpu_to_je32(get_seconds());
 722         rd->nsize = namelen;
 723
 724         /* XXX: This is ugly. */
 725         rd->type = (mode & S_IFMT) >> 12;
 726
 727         rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
 728         rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
 729
 730         fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
 731
 732         if (IS_ERR(fd)) {
 733                 /* dirent failed to write. Delete the inode normally
 734                    as if it were the final unlink() */
 735                 jffs2_complete_reservation(c);
 736                 jffs2_free_raw_dirent(rd);
 737                 mutex_unlock(&dir_f->sem);
 738                 ret = PTR_ERR(fd);
 739                 goto fail;
 740         }
 741
 742         dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
 743
 744         jffs2_free_raw_dirent(rd);
 745
 746         /* Link the fd into the inode's list, obsoleting an old
 747            one if necessary. */
 748         jffs2_add_fd_to_list(c, fd, &dir_f->dents);
 749
 750         mutex_unlock(&dir_f->sem);
 751         jffs2_complete_reservation(c);
 752
 753         unlock_new_inode(inode);
 754         d_instantiate(dentry, inode);
 755         return 0;
 756
 757  fail:
 758         iget_failed(inode);
 759         return ret;
 760 }
 761
 762 static int jffs2_rename (struct inode *old_dir_i, struct dentry *old_dentry,
 763                          struct inode *new_dir_i, struct dentry *new_dentry,
 764                          unsigned int flags)
 765 {
 766         int ret;
 767         struct jffs2_sb_info *c = JFFS2_SB_INFO(old_dir_i->i_sb);
 768         struct jffs2_inode_info *victim_f = NULL;
 769         uint8_t type;
 770         uint32_t now;
 771
 772         if (flags & ~RENAME_NOREPLACE)
 773                 return -EINVAL;
 774
 775         /* The VFS will check for us and prevent trying to rename a
 776          * file over a directory and vice versa, but if it's a directory,
 777          * the VFS can't check whether the victim is empty. The filesystem
 778          * needs to do that for itself.
 779          */
 780         if (d_really_is_positive(new_dentry)) {
 781                 victim_f = JFFS2_INODE_INFO(d_inode(new_dentry));
 782                 if (d_is_dir(new_dentry)) {
 783                         struct jffs2_full_dirent *fd;
 784
 785                         mutex_lock(&victim_f->sem);
 786                         for (fd = victim_f->dents; fd; fd = fd->next) {
 787                                 if (fd->ino) {
 788                                         mutex_unlock(&victim_f->sem);
 789                                         return -ENOTEMPTY;
 790                                 }
 791                         }
 792                         mutex_unlock(&victim_f->sem);
 793                 }
 794         }
 795
 796         /* XXX: We probably ought to alloc enough space for
 797            both nodes at the same time. Writing the new link,
 798            then getting -ENOSPC, is quite bad :)
 799         */
 800
 801         /* Make a hard link */
 802
 803         /* XXX: This is ugly */
 804         type = (d_inode(old_dentry)->i_mode & S_IFMT) >> 12;
 805         if (!type) type = DT_REG;
 806
 807         now = get_seconds();
 808         ret = jffs2_do_link(c, JFFS2_INODE_INFO(new_dir_i),
 809                             d_inode(old_dentry)->i_ino, type,
 810                             new_dentry->d_name.name, new_dentry->d_name.len, now);
 811
 812         if (ret)
 813                 return ret;
 814
 815         if (victim_f) {
 816                 /* There was a victim. Kill it off nicely */
 817                 if (d_is_dir(new_dentry))
 818                         clear_nlink(d_inode(new_dentry));
 819                 else
 820                         drop_nlink(d_inode(new_dentry));
 821                 /* Don't oops if the victim was a dirent pointing to an
 822                    inode which didn't exist. */
 823                 if (victim_f->inocache) {
 824                         mutex_lock(&victim_f->sem);
 825                         if (d_is_dir(new_dentry))
 826                                 victim_f->inocache->pino_nlink = 0;
 827                         else
 828                                 victim_f->inocache->pino_nlink--;
 829                         mutex_unlock(&victim_f->sem);
 830                 }
 831         }
 832
 833         /* If it was a directory we moved, and there was no victim,
 834            increase i_nlink on its new parent */
 835         if (d_is_dir(old_dentry) && !victim_f)
 836                 inc_nlink(new_dir_i);
 837
 838         /* Unlink the original */
 839         ret = jffs2_do_unlink(c, JFFS2_INODE_INFO(old_dir_i),
 840                               old_dentry->d_name.name, old_dentry->d_name.len, NULL, now);
 841
 842         /* We don't touch inode->i_nlink */
 843
 844         if (ret) {
 845                 /* Oh shit. We really ought to make a single node which can do both atomically */
 846                 struct jffs2_inode_info *f = JFFS2_INODE_INFO(d_inode(old_dentry));
 847                 mutex_lock(&f->sem);
 848                 inc_nlink(d_inode(old_dentry));
 849                 if (f->inocache && !d_is_dir(old_dentry))
 850                         f->inocache->pino_nlink++;
 851                 mutex_unlock(&f->sem);
 852
 853                 pr_notice("%s(): Link succeeded, unlink failed (err %d). You now have a hard link\n",
 854                           __func__, ret);
 855                 /*
 856                  * We can't keep the target in dcache after that.
 857                  * For one thing, we can't afford dentry aliases for directories.
 858                  * For another, if there was a victim, we _can't_ set new inode
 859                  * for that sucker and we have to trigger mount eviction - the
 860                  * caller won't do it on its own since we are returning an error.
 861                  */
 862                 d_invalidate(new_dentry);
 863                 new_dir_i->i_mtime = new_dir_i->i_ctime = ITIME(now);
 864                 return ret;
 865         }
 866
 867         if (d_is_dir(old_dentry))
 868                 drop_nlink(old_dir_i);
 869
 870         new_dir_i->i_mtime = new_dir_i->i_ctime = old_dir_i->i_mtime = old_dir_i->i_ctime = ITIME(now);
 871
 872         return 0;
 873 }
 874