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