fs/jffs2/dir.c

/* [<][>][^][v][top][bottom][index][help] */
This source file includes following definitions.
jffs2_lookup
jffs2_readdir
jffs2_create
jffs2_unlink
jffs2_link
jffs2_symlink
jffs2_mkdir
jffs2_rmdir
jffs2_mknod
jffs2_rename
   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         d_instantiate_new(dentry, inode);
 213         return 0;
 214 
 215  fail:
 216         iget_failed(inode);
 217         jffs2_free_raw_inode(ri);
 218         return ret;
 219 }
 220 
 221 /***********************************************************************/
 222 
 223 
 224 static int jffs2_unlink(struct inode *dir_i, struct dentry *dentry)
 225 {
 226         struct jffs2_sb_info *c = JFFS2_SB_INFO(dir_i->i_sb);
 227         struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
 228         struct jffs2_inode_info *dead_f = JFFS2_INODE_INFO(d_inode(dentry));
 229         int ret;
 230         uint32_t now = JFFS2_NOW();
 231 
 232         ret = jffs2_do_unlink(c, dir_f, dentry->d_name.name,
 233                               dentry->d_name.len, dead_f, now);
 234         if (dead_f->inocache)
 235                 set_nlink(d_inode(dentry), dead_f->inocache->pino_nlink);
 236         if (!ret)
 237                 dir_i->i_mtime = dir_i->i_ctime = ITIME(now);
 238         return ret;
 239 }
 240 /***********************************************************************/
 241 
 242 
 243 static int jffs2_link (struct dentry *old_dentry, struct inode *dir_i, struct dentry *dentry)
 244 {
 245         struct jffs2_sb_info *c = JFFS2_SB_INFO(old_dentry->d_sb);
 246         struct jffs2_inode_info *f = JFFS2_INODE_INFO(d_inode(old_dentry));
 247         struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
 248         int ret;
 249         uint8_t type;
 250         uint32_t now;
 251 
 252         /* Don't let people make hard links to bad inodes. */
 253         if (!f->inocache)
 254                 return -EIO;
 255 
 256         if (d_is_dir(old_dentry))
 257                 return -EPERM;
 258 
 259         /* XXX: This is ugly */
 260         type = (d_inode(old_dentry)->i_mode & S_IFMT) >> 12;
 261         if (!type) type = DT_REG;
 262 
 263         now = JFFS2_NOW();
 264         ret = jffs2_do_link(c, dir_f, f->inocache->ino, type, dentry->d_name.name, dentry->d_name.len, now);
 265 
 266         if (!ret) {
 267                 mutex_lock(&f->sem);
 268                 set_nlink(d_inode(old_dentry), ++f->inocache->pino_nlink);
 269                 mutex_unlock(&f->sem);
 270                 d_instantiate(dentry, d_inode(old_dentry));
 271                 dir_i->i_mtime = dir_i->i_ctime = ITIME(now);
 272                 ihold(d_inode(old_dentry));
 273         }
 274         return ret;
 275 }
 276 
 277 /***********************************************************************/
 278 
 279 static int jffs2_symlink (struct inode *dir_i, struct dentry *dentry, const char *target)
 280 {
 281         struct jffs2_inode_info *f, *dir_f;
 282         struct jffs2_sb_info *c;
 283         struct inode *inode;
 284         struct jffs2_raw_inode *ri;
 285         struct jffs2_raw_dirent *rd;
 286         struct jffs2_full_dnode *fn;
 287         struct jffs2_full_dirent *fd;
 288         int namelen;
 289         uint32_t alloclen;
 290         int ret, targetlen = strlen(target);
 291 
 292         /* FIXME: If you care. We'd need to use frags for the target
 293            if it grows much more than this */
 294         if (targetlen > 254)
 295                 return -ENAMETOOLONG;
 296 
 297         ri = jffs2_alloc_raw_inode();
 298 
 299         if (!ri)
 300                 return -ENOMEM;
 301 
 302         c = JFFS2_SB_INFO(dir_i->i_sb);
 303 
 304         /* Try to reserve enough space for both node and dirent.
 305          * Just the node will do for now, though
 306          */
 307         namelen = dentry->d_name.len;
 308         ret = jffs2_reserve_space(c, sizeof(*ri) + targetlen, &alloclen,
 309                                   ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
 310 
 311         if (ret) {
 312                 jffs2_free_raw_inode(ri);
 313                 return ret;
 314         }
 315 
 316         inode = jffs2_new_inode(dir_i, S_IFLNK | S_IRWXUGO, ri);
 317 
 318         if (IS_ERR(inode)) {
 319                 jffs2_free_raw_inode(ri);
 320                 jffs2_complete_reservation(c);
 321                 return PTR_ERR(inode);
 322         }
 323 
 324         inode->i_op = &jffs2_symlink_inode_operations;
 325 
 326         f = JFFS2_INODE_INFO(inode);
 327 
 328         inode->i_size = targetlen;
 329         ri->isize = ri->dsize = ri->csize = cpu_to_je32(inode->i_size);
 330         ri->totlen = cpu_to_je32(sizeof(*ri) + inode->i_size);
 331         ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
 332 
 333         ri->compr = JFFS2_COMPR_NONE;
 334         ri->data_crc = cpu_to_je32(crc32(0, target, targetlen));
 335         ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
 336 
 337         fn = jffs2_write_dnode(c, f, ri, target, targetlen, ALLOC_NORMAL);
 338 
 339         jffs2_free_raw_inode(ri);
 340 
 341         if (IS_ERR(fn)) {
 342                 /* Eeek. Wave bye bye */
 343                 mutex_unlock(&f->sem);
 344                 jffs2_complete_reservation(c);
 345                 ret = PTR_ERR(fn);
 346                 goto fail;
 347         }
 348 
 349         /* We use f->target field to store the target path. */
 350         f->target = kmemdup(target, targetlen + 1, GFP_KERNEL);
 351         if (!f->target) {
 352                 pr_warn("Can't allocate %d bytes of memory\n", targetlen + 1);
 353                 mutex_unlock(&f->sem);
 354                 jffs2_complete_reservation(c);
 355                 ret = -ENOMEM;
 356                 goto fail;
 357         }
 358         inode->i_link = f->target;
 359 
 360         jffs2_dbg(1, "%s(): symlink's target '%s' cached\n",
 361                   __func__, (char *)f->target);
 362 
 363         /* No data here. Only a metadata node, which will be
 364            obsoleted by the first data write
 365         */
 366         f->metadata = fn;
 367         mutex_unlock(&f->sem);
 368 
 369         jffs2_complete_reservation(c);
 370 
 371         ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
 372         if (ret)
 373                 goto fail;
 374 
 375         ret = jffs2_init_acl_post(inode);
 376         if (ret)
 377                 goto fail;
 378 
 379         ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
 380                                   ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
 381         if (ret)
 382                 goto fail;
 383 
 384         rd = jffs2_alloc_raw_dirent();
 385         if (!rd) {
 386                 /* Argh. Now we treat it like a normal delete */
 387                 jffs2_complete_reservation(c);
 388                 ret = -ENOMEM;
 389                 goto fail;
 390         }
 391 
 392         dir_f = JFFS2_INODE_INFO(dir_i);
 393         mutex_lock(&dir_f->sem);
 394 
 395         rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
 396         rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
 397         rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
 398         rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
 399 
 400         rd->pino = cpu_to_je32(dir_i->i_ino);
 401         rd->version = cpu_to_je32(++dir_f->highest_version);
 402         rd->ino = cpu_to_je32(inode->i_ino);
 403         rd->mctime = cpu_to_je32(JFFS2_NOW());
 404         rd->nsize = namelen;
 405         rd->type = DT_LNK;
 406         rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
 407         rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
 408 
 409         fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
 410 
 411         if (IS_ERR(fd)) {
 412                 /* dirent failed to write. Delete the inode normally
 413                    as if it were the final unlink() */
 414                 jffs2_complete_reservation(c);
 415                 jffs2_free_raw_dirent(rd);
 416                 mutex_unlock(&dir_f->sem);
 417                 ret = PTR_ERR(fd);
 418                 goto fail;
 419         }
 420 
 421         dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
 422 
 423         jffs2_free_raw_dirent(rd);
 424 
 425         /* Link the fd into the inode's list, obsoleting an old
 426            one if necessary. */
 427         jffs2_add_fd_to_list(c, fd, &dir_f->dents);
 428 
 429         mutex_unlock(&dir_f->sem);
 430         jffs2_complete_reservation(c);
 431 
 432         d_instantiate_new(dentry, inode);
 433         return 0;
 434 
 435  fail:
 436         iget_failed(inode);
 437         return ret;
 438 }
 439 
 440 
 441 static int jffs2_mkdir (struct inode *dir_i, struct dentry *dentry, umode_t mode)
 442 {
 443         struct jffs2_inode_info *f, *dir_f;
 444         struct jffs2_sb_info *c;
 445         struct inode *inode;
 446         struct jffs2_raw_inode *ri;
 447         struct jffs2_raw_dirent *rd;
 448         struct jffs2_full_dnode *fn;
 449         struct jffs2_full_dirent *fd;
 450         int namelen;
 451         uint32_t alloclen;
 452         int ret;
 453 
 454         mode |= S_IFDIR;
 455 
 456         ri = jffs2_alloc_raw_inode();
 457         if (!ri)
 458                 return -ENOMEM;
 459 
 460         c = JFFS2_SB_INFO(dir_i->i_sb);
 461 
 462         /* Try to reserve enough space for both node and dirent.
 463          * Just the node will do for now, though
 464          */
 465         namelen = dentry->d_name.len;
 466         ret = jffs2_reserve_space(c, sizeof(*ri), &alloclen, ALLOC_NORMAL,
 467                                   JFFS2_SUMMARY_INODE_SIZE);
 468 
 469         if (ret) {
 470                 jffs2_free_raw_inode(ri);
 471                 return ret;
 472         }
 473 
 474         inode = jffs2_new_inode(dir_i, mode, ri);
 475 
 476         if (IS_ERR(inode)) {
 477                 jffs2_free_raw_inode(ri);
 478                 jffs2_complete_reservation(c);
 479                 return PTR_ERR(inode);
 480         }
 481 
 482         inode->i_op = &jffs2_dir_inode_operations;
 483         inode->i_fop = &jffs2_dir_operations;
 484 
 485         f = JFFS2_INODE_INFO(inode);
 486 
 487         /* Directories get nlink 2 at start */
 488         set_nlink(inode, 2);
 489         /* but ic->pino_nlink is the parent ino# */
 490         f->inocache->pino_nlink = dir_i->i_ino;
 491 
 492         ri->data_crc = cpu_to_je32(0);
 493         ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
 494 
 495         fn = jffs2_write_dnode(c, f, ri, NULL, 0, ALLOC_NORMAL);
 496 
 497         jffs2_free_raw_inode(ri);
 498 
 499         if (IS_ERR(fn)) {
 500                 /* Eeek. Wave bye bye */
 501                 mutex_unlock(&f->sem);
 502                 jffs2_complete_reservation(c);
 503                 ret = PTR_ERR(fn);
 504                 goto fail;
 505         }
 506         /* No data here. Only a metadata node, which will be
 507            obsoleted by the first data write
 508         */
 509         f->metadata = fn;
 510         mutex_unlock(&f->sem);
 511 
 512         jffs2_complete_reservation(c);
 513 
 514         ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
 515         if (ret)
 516                 goto fail;
 517 
 518         ret = jffs2_init_acl_post(inode);
 519         if (ret)
 520                 goto fail;
 521 
 522         ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
 523                                   ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
 524         if (ret)
 525                 goto fail;
 526 
 527         rd = jffs2_alloc_raw_dirent();
 528         if (!rd) {
 529                 /* Argh. Now we treat it like a normal delete */
 530                 jffs2_complete_reservation(c);
 531                 ret = -ENOMEM;
 532                 goto fail;
 533         }
 534 
 535         dir_f = JFFS2_INODE_INFO(dir_i);
 536         mutex_lock(&dir_f->sem);
 537 
 538         rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
 539         rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
 540         rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
 541         rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
 542 
 543         rd->pino = cpu_to_je32(dir_i->i_ino);
 544         rd->version = cpu_to_je32(++dir_f->highest_version);
 545         rd->ino = cpu_to_je32(inode->i_ino);
 546         rd->mctime = cpu_to_je32(JFFS2_NOW());
 547         rd->nsize = namelen;
 548         rd->type = DT_DIR;
 549         rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
 550         rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
 551 
 552         fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
 553 
 554         if (IS_ERR(fd)) {
 555                 /* dirent failed to write. Delete the inode normally
 556                    as if it were the final unlink() */
 557                 jffs2_complete_reservation(c);
 558                 jffs2_free_raw_dirent(rd);
 559                 mutex_unlock(&dir_f->sem);
 560                 ret = PTR_ERR(fd);
 561                 goto fail;
 562         }
 563 
 564         dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
 565         inc_nlink(dir_i);
 566 
 567         jffs2_free_raw_dirent(rd);
 568 
 569         /* Link the fd into the inode's list, obsoleting an old
 570            one if necessary. */
 571         jffs2_add_fd_to_list(c, fd, &dir_f->dents);
 572 
 573         mutex_unlock(&dir_f->sem);
 574         jffs2_complete_reservation(c);
 575 
 576         d_instantiate_new(dentry, inode);
 577         return 0;
 578 
 579  fail:
 580         iget_failed(inode);
 581         return ret;
 582 }
 583 
 584 static int jffs2_rmdir (struct inode *dir_i, struct dentry *dentry)
 585 {
 586         struct jffs2_sb_info *c = JFFS2_SB_INFO(dir_i->i_sb);
 587         struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
 588         struct jffs2_inode_info *f = JFFS2_INODE_INFO(d_inode(dentry));
 589         struct jffs2_full_dirent *fd;
 590         int ret;
 591         uint32_t now = JFFS2_NOW();
 592 
 593         for (fd = f->dents ; fd; fd = fd->next) {
 594                 if (fd->ino)
 595                         return -ENOTEMPTY;
 596         }
 597 
 598         ret = jffs2_do_unlink(c, dir_f, dentry->d_name.name,
 599                               dentry->d_name.len, f, now);
 600         if (!ret) {
 601                 dir_i->i_mtime = dir_i->i_ctime = ITIME(now);
 602                 clear_nlink(d_inode(dentry));
 603                 drop_nlink(dir_i);
 604         }
 605         return ret;
 606 }
 607 
 608 static int jffs2_mknod (struct inode *dir_i, struct dentry *dentry, umode_t mode, dev_t rdev)
 609 {
 610         struct jffs2_inode_info *f, *dir_f;
 611         struct jffs2_sb_info *c;
 612         struct inode *inode;
 613         struct jffs2_raw_inode *ri;
 614         struct jffs2_raw_dirent *rd;
 615         struct jffs2_full_dnode *fn;
 616         struct jffs2_full_dirent *fd;
 617         int namelen;
 618         union jffs2_device_node dev;
 619         int devlen = 0;
 620         uint32_t alloclen;
 621         int ret;
 622 
 623         ri = jffs2_alloc_raw_inode();
 624         if (!ri)
 625                 return -ENOMEM;
 626 
 627         c = JFFS2_SB_INFO(dir_i->i_sb);
 628 
 629         if (S_ISBLK(mode) || S_ISCHR(mode))
 630                 devlen = jffs2_encode_dev(&dev, rdev);
 631 
 632         /* Try to reserve enough space for both node and dirent.
 633          * Just the node will do for now, though
 634          */
 635         namelen = dentry->d_name.len;
 636         ret = jffs2_reserve_space(c, sizeof(*ri) + devlen, &alloclen,
 637                                   ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
 638 
 639         if (ret) {
 640                 jffs2_free_raw_inode(ri);
 641                 return ret;
 642         }
 643 
 644         inode = jffs2_new_inode(dir_i, mode, ri);
 645 
 646         if (IS_ERR(inode)) {
 647                 jffs2_free_raw_inode(ri);
 648                 jffs2_complete_reservation(c);
 649                 return PTR_ERR(inode);
 650         }
 651         inode->i_op = &jffs2_file_inode_operations;
 652         init_special_inode(inode, inode->i_mode, rdev);
 653 
 654         f = JFFS2_INODE_INFO(inode);
 655 
 656         ri->dsize = ri->csize = cpu_to_je32(devlen);
 657         ri->totlen = cpu_to_je32(sizeof(*ri) + devlen);
 658         ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
 659 
 660         ri->compr = JFFS2_COMPR_NONE;
 661         ri->data_crc = cpu_to_je32(crc32(0, &dev, devlen));
 662         ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
 663 
 664         fn = jffs2_write_dnode(c, f, ri, (char *)&dev, devlen, ALLOC_NORMAL);
 665 
 666         jffs2_free_raw_inode(ri);
 667 
 668         if (IS_ERR(fn)) {
 669                 /* Eeek. Wave bye bye */
 670                 mutex_unlock(&f->sem);
 671                 jffs2_complete_reservation(c);
 672                 ret = PTR_ERR(fn);
 673                 goto fail;
 674         }
 675         /* No data here. Only a metadata node, which will be
 676            obsoleted by the first data write
 677         */
 678         f->metadata = fn;
 679         mutex_unlock(&f->sem);
 680 
 681         jffs2_complete_reservation(c);
 682 
 683         ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
 684         if (ret)
 685                 goto fail;
 686 
 687         ret = jffs2_init_acl_post(inode);
 688         if (ret)
 689                 goto fail;
 690 
 691         ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
 692                                   ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
 693         if (ret)
 694                 goto fail;
 695 
 696         rd = jffs2_alloc_raw_dirent();
 697         if (!rd) {
 698                 /* Argh. Now we treat it like a normal delete */
 699                 jffs2_complete_reservation(c);
 700                 ret = -ENOMEM;
 701                 goto fail;
 702         }
 703 
 704         dir_f = JFFS2_INODE_INFO(dir_i);
 705         mutex_lock(&dir_f->sem);
 706 
 707         rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
 708         rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
 709         rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
 710         rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
 711 
 712         rd->pino = cpu_to_je32(dir_i->i_ino);
 713         rd->version = cpu_to_je32(++dir_f->highest_version);
 714         rd->ino = cpu_to_je32(inode->i_ino);
 715         rd->mctime = cpu_to_je32(JFFS2_NOW());
 716         rd->nsize = namelen;
 717 
 718         /* XXX: This is ugly. */
 719         rd->type = (mode & S_IFMT) >> 12;
 720 
 721         rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
 722         rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
 723 
 724         fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
 725 
 726         if (IS_ERR(fd)) {
 727                 /* dirent failed to write. Delete the inode normally
 728                    as if it were the final unlink() */
 729                 jffs2_complete_reservation(c);
 730                 jffs2_free_raw_dirent(rd);
 731                 mutex_unlock(&dir_f->sem);
 732                 ret = PTR_ERR(fd);
 733                 goto fail;
 734         }
 735 
 736         dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
 737 
 738         jffs2_free_raw_dirent(rd);
 739 
 740         /* Link the fd into the inode's list, obsoleting an old
 741            one if necessary. */
 742         jffs2_add_fd_to_list(c, fd, &dir_f->dents);
 743 
 744         mutex_unlock(&dir_f->sem);
 745         jffs2_complete_reservation(c);
 746 
 747         d_instantiate_new(dentry, inode);
 748         return 0;
 749 
 750  fail:
 751         iget_failed(inode);
 752         return ret;
 753 }
 754 
 755 static int jffs2_rename (struct inode *old_dir_i, struct dentry *old_dentry,
 756                          struct inode *new_dir_i, struct dentry *new_dentry,
 757                          unsigned int flags)
 758 {
 759         int ret;
 760         struct jffs2_sb_info *c = JFFS2_SB_INFO(old_dir_i->i_sb);
 761         struct jffs2_inode_info *victim_f = NULL;
 762         uint8_t type;
 763         uint32_t now;
 764 
 765         if (flags & ~RENAME_NOREPLACE)
 766                 return -EINVAL;
 767 
 768         /* The VFS will check for us and prevent trying to rename a
 769          * file over a directory and vice versa, but if it's a directory,
 770          * the VFS can't check whether the victim is empty. The filesystem
 771          * needs to do that for itself.
 772          */
 773         if (d_really_is_positive(new_dentry)) {
 774                 victim_f = JFFS2_INODE_INFO(d_inode(new_dentry));
 775                 if (d_is_dir(new_dentry)) {
 776                         struct jffs2_full_dirent *fd;
 777 
 778                         mutex_lock(&victim_f->sem);
 779                         for (fd = victim_f->dents; fd; fd = fd->next) {
 780                                 if (fd->ino) {
 781                                         mutex_unlock(&victim_f->sem);
 782                                         return -ENOTEMPTY;
 783                                 }
 784                         }
 785                         mutex_unlock(&victim_f->sem);
 786                 }
 787         }
 788 
 789         /* XXX: We probably ought to alloc enough space for
 790            both nodes at the same time. Writing the new link,
 791            then getting -ENOSPC, is quite bad :)
 792         */
 793 
 794         /* Make a hard link */
 795 
 796         /* XXX: This is ugly */
 797         type = (d_inode(old_dentry)->i_mode & S_IFMT) >> 12;
 798         if (!type) type = DT_REG;
 799 
 800         now = JFFS2_NOW();
 801         ret = jffs2_do_link(c, JFFS2_INODE_INFO(new_dir_i),
 802                             d_inode(old_dentry)->i_ino, type,
 803                             new_dentry->d_name.name, new_dentry->d_name.len, now);
 804 
 805         if (ret)
 806                 return ret;
 807 
 808         if (victim_f) {
 809                 /* There was a victim. Kill it off nicely */
 810                 if (d_is_dir(new_dentry))
 811                         clear_nlink(d_inode(new_dentry));
 812                 else
 813                         drop_nlink(d_inode(new_dentry));
 814                 /* Don't oops if the victim was a dirent pointing to an
 815                    inode which didn't exist. */
 816                 if (victim_f->inocache) {
 817                         mutex_lock(&victim_f->sem);
 818                         if (d_is_dir(new_dentry))
 819                                 victim_f->inocache->pino_nlink = 0;
 820                         else
 821                                 victim_f->inocache->pino_nlink--;
 822                         mutex_unlock(&victim_f->sem);
 823                 }
 824         }
 825 
 826         /* If it was a directory we moved, and there was no victim,
 827            increase i_nlink on its new parent */
 828         if (d_is_dir(old_dentry) && !victim_f)
 829                 inc_nlink(new_dir_i);
 830 
 831         /* Unlink the original */
 832         ret = jffs2_do_unlink(c, JFFS2_INODE_INFO(old_dir_i),
 833                               old_dentry->d_name.name, old_dentry->d_name.len, NULL, now);
 834 
 835         /* We don't touch inode->i_nlink */
 836 
 837         if (ret) {
 838                 /* Oh shit. We really ought to make a single node which can do both atomically */
 839                 struct jffs2_inode_info *f = JFFS2_INODE_INFO(d_inode(old_dentry));
 840                 mutex_lock(&f->sem);
 841                 inc_nlink(d_inode(old_dentry));
 842                 if (f->inocache && !d_is_dir(old_dentry))
 843                         f->inocache->pino_nlink++;
 844                 mutex_unlock(&f->sem);
 845 
 846                 pr_notice("%s(): Link succeeded, unlink failed (err %d). You now have a hard link\n",
 847                           __func__, ret);
 848                 /*
 849                  * We can't keep the target in dcache after that.
 850                  * For one thing, we can't afford dentry aliases for directories.
 851                  * For another, if there was a victim, we _can't_ set new inode
 852                  * for that sucker and we have to trigger mount eviction - the
 853                  * caller won't do it on its own since we are returning an error.
 854                  */
 855                 d_invalidate(new_dentry);
 856                 new_dir_i->i_mtime = new_dir_i->i_ctime = ITIME(now);
 857                 return ret;
 858         }
 859 
 860         if (d_is_dir(old_dentry))
 861                 drop_nlink(old_dir_i);
 862 
 863         new_dir_i->i_mtime = new_dir_i->i_ctime = old_dir_i->i_mtime = old_dir_i->i_ctime = ITIME(now);
 864 
 865         return 0;
 866 }
 867
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root/fs/jffs2/dir.c

DEFINITIONS
