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