| 1 | /* dir.c: AFS filesystem directory handling |
| 2 | * |
| 3 | * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved. |
| 4 | * Written by David Howells (dhowells@redhat.com) |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU General Public License |
| 8 | * as published by the Free Software Foundation; either version |
| 9 | * 2 of the License, or (at your option) any later version. |
| 10 | */ |
| 11 | |
| 12 | #include <linux/kernel.h> |
| 13 | #include <linux/module.h> |
| 14 | #include <linux/init.h> |
| 15 | #include <linux/fs.h> |
| 16 | #include <linux/namei.h> |
| 17 | #include <linux/pagemap.h> |
| 18 | #include <linux/ctype.h> |
| 19 | #include <linux/sched.h> |
| 20 | #include "internal.h" |
| 21 | |
| 22 | static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry, |
| 23 | unsigned int flags); |
| 24 | static int afs_dir_open(struct inode *inode, struct file *file); |
| 25 | static int afs_readdir(struct file *file, struct dir_context *ctx); |
| 26 | static int afs_d_revalidate(struct dentry *dentry, unsigned int flags); |
| 27 | static int afs_d_delete(const struct dentry *dentry); |
| 28 | static void afs_d_release(struct dentry *dentry); |
| 29 | static int afs_lookup_filldir(struct dir_context *ctx, const char *name, int nlen, |
| 30 | loff_t fpos, u64 ino, unsigned dtype); |
| 31 | static int afs_create(struct inode *dir, struct dentry *dentry, umode_t mode, |
| 32 | bool excl); |
| 33 | static int afs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode); |
| 34 | static int afs_rmdir(struct inode *dir, struct dentry *dentry); |
| 35 | static int afs_unlink(struct inode *dir, struct dentry *dentry); |
| 36 | static int afs_link(struct dentry *from, struct inode *dir, |
| 37 | struct dentry *dentry); |
| 38 | static int afs_symlink(struct inode *dir, struct dentry *dentry, |
| 39 | const char *content); |
| 40 | static int afs_rename(struct inode *old_dir, struct dentry *old_dentry, |
| 41 | struct inode *new_dir, struct dentry *new_dentry); |
| 42 | |
| 43 | const struct file_operations afs_dir_file_operations = { |
| 44 | .open = afs_dir_open, |
| 45 | .release = afs_release, |
| 46 | .iterate = afs_readdir, |
| 47 | .lock = afs_lock, |
| 48 | .llseek = generic_file_llseek, |
| 49 | }; |
| 50 | |
| 51 | const struct inode_operations afs_dir_inode_operations = { |
| 52 | .create = afs_create, |
| 53 | .lookup = afs_lookup, |
| 54 | .link = afs_link, |
| 55 | .unlink = afs_unlink, |
| 56 | .symlink = afs_symlink, |
| 57 | .mkdir = afs_mkdir, |
| 58 | .rmdir = afs_rmdir, |
| 59 | .rename = afs_rename, |
| 60 | .permission = afs_permission, |
| 61 | .getattr = afs_getattr, |
| 62 | .setattr = afs_setattr, |
| 63 | }; |
| 64 | |
| 65 | const struct dentry_operations afs_fs_dentry_operations = { |
| 66 | .d_revalidate = afs_d_revalidate, |
| 67 | .d_delete = afs_d_delete, |
| 68 | .d_release = afs_d_release, |
| 69 | .d_automount = afs_d_automount, |
| 70 | }; |
| 71 | |
| 72 | #define AFS_DIR_HASHTBL_SIZE 128 |
| 73 | #define AFS_DIR_DIRENT_SIZE 32 |
| 74 | #define AFS_DIRENT_PER_BLOCK 64 |
| 75 | |
| 76 | union afs_dirent { |
| 77 | struct { |
| 78 | uint8_t valid; |
| 79 | uint8_t unused[1]; |
| 80 | __be16 hash_next; |
| 81 | __be32 vnode; |
| 82 | __be32 unique; |
| 83 | uint8_t name[16]; |
| 84 | uint8_t overflow[4]; /* if any char of the name (inc |
| 85 | * NUL) reaches here, consume |
| 86 | * the next dirent too */ |
| 87 | } u; |
| 88 | uint8_t extended_name[32]; |
| 89 | }; |
| 90 | |
| 91 | /* AFS directory page header (one at the beginning of every 2048-byte chunk) */ |
| 92 | struct afs_dir_pagehdr { |
| 93 | __be16 npages; |
| 94 | __be16 magic; |
| 95 | #define AFS_DIR_MAGIC htons(1234) |
| 96 | uint8_t nentries; |
| 97 | uint8_t bitmap[8]; |
| 98 | uint8_t pad[19]; |
| 99 | }; |
| 100 | |
| 101 | /* directory block layout */ |
| 102 | union afs_dir_block { |
| 103 | |
| 104 | struct afs_dir_pagehdr pagehdr; |
| 105 | |
| 106 | struct { |
| 107 | struct afs_dir_pagehdr pagehdr; |
| 108 | uint8_t alloc_ctrs[128]; |
| 109 | /* dir hash table */ |
| 110 | uint16_t hashtable[AFS_DIR_HASHTBL_SIZE]; |
| 111 | } hdr; |
| 112 | |
| 113 | union afs_dirent dirents[AFS_DIRENT_PER_BLOCK]; |
| 114 | }; |
| 115 | |
| 116 | /* layout on a linux VM page */ |
| 117 | struct afs_dir_page { |
| 118 | union afs_dir_block blocks[PAGE_SIZE / sizeof(union afs_dir_block)]; |
| 119 | }; |
| 120 | |
| 121 | struct afs_lookup_cookie { |
| 122 | struct dir_context ctx; |
| 123 | struct afs_fid fid; |
| 124 | struct qstr name; |
| 125 | int found; |
| 126 | }; |
| 127 | |
| 128 | /* |
| 129 | * check that a directory page is valid |
| 130 | */ |
| 131 | static inline void afs_dir_check_page(struct inode *dir, struct page *page) |
| 132 | { |
| 133 | struct afs_dir_page *dbuf; |
| 134 | loff_t latter; |
| 135 | int tmp, qty; |
| 136 | |
| 137 | #if 0 |
| 138 | /* check the page count */ |
| 139 | qty = desc.size / sizeof(dbuf->blocks[0]); |
| 140 | if (qty == 0) |
| 141 | goto error; |
| 142 | |
| 143 | if (page->index == 0 && qty != ntohs(dbuf->blocks[0].pagehdr.npages)) { |
| 144 | printk("kAFS: %s(%lu): wrong number of dir blocks %d!=%hu\n", |
| 145 | __func__, dir->i_ino, qty, |
| 146 | ntohs(dbuf->blocks[0].pagehdr.npages)); |
| 147 | goto error; |
| 148 | } |
| 149 | #endif |
| 150 | |
| 151 | /* determine how many magic numbers there should be in this page */ |
| 152 | latter = dir->i_size - page_offset(page); |
| 153 | if (latter >= PAGE_SIZE) |
| 154 | qty = PAGE_SIZE; |
| 155 | else |
| 156 | qty = latter; |
| 157 | qty /= sizeof(union afs_dir_block); |
| 158 | |
| 159 | /* check them */ |
| 160 | dbuf = page_address(page); |
| 161 | for (tmp = 0; tmp < qty; tmp++) { |
| 162 | if (dbuf->blocks[tmp].pagehdr.magic != AFS_DIR_MAGIC) { |
| 163 | printk("kAFS: %s(%lu): bad magic %d/%d is %04hx\n", |
| 164 | __func__, dir->i_ino, tmp, qty, |
| 165 | ntohs(dbuf->blocks[tmp].pagehdr.magic)); |
| 166 | goto error; |
| 167 | } |
| 168 | } |
| 169 | |
| 170 | SetPageChecked(page); |
| 171 | return; |
| 172 | |
| 173 | error: |
| 174 | SetPageChecked(page); |
| 175 | SetPageError(page); |
| 176 | } |
| 177 | |
| 178 | /* |
| 179 | * discard a page cached in the pagecache |
| 180 | */ |
| 181 | static inline void afs_dir_put_page(struct page *page) |
| 182 | { |
| 183 | kunmap(page); |
| 184 | page_cache_release(page); |
| 185 | } |
| 186 | |
| 187 | /* |
| 188 | * get a page into the pagecache |
| 189 | */ |
| 190 | static struct page *afs_dir_get_page(struct inode *dir, unsigned long index, |
| 191 | struct key *key) |
| 192 | { |
| 193 | struct page *page; |
| 194 | _enter("{%lu},%lu", dir->i_ino, index); |
| 195 | |
| 196 | page = read_cache_page(dir->i_mapping, index, afs_page_filler, key); |
| 197 | if (!IS_ERR(page)) { |
| 198 | kmap(page); |
| 199 | if (!PageChecked(page)) |
| 200 | afs_dir_check_page(dir, page); |
| 201 | if (PageError(page)) |
| 202 | goto fail; |
| 203 | } |
| 204 | return page; |
| 205 | |
| 206 | fail: |
| 207 | afs_dir_put_page(page); |
| 208 | _leave(" = -EIO"); |
| 209 | return ERR_PTR(-EIO); |
| 210 | } |
| 211 | |
| 212 | /* |
| 213 | * open an AFS directory file |
| 214 | */ |
| 215 | static int afs_dir_open(struct inode *inode, struct file *file) |
| 216 | { |
| 217 | _enter("{%lu}", inode->i_ino); |
| 218 | |
| 219 | BUILD_BUG_ON(sizeof(union afs_dir_block) != 2048); |
| 220 | BUILD_BUG_ON(sizeof(union afs_dirent) != 32); |
| 221 | |
| 222 | if (test_bit(AFS_VNODE_DELETED, &AFS_FS_I(inode)->flags)) |
| 223 | return -ENOENT; |
| 224 | |
| 225 | return afs_open(inode, file); |
| 226 | } |
| 227 | |
| 228 | /* |
| 229 | * deal with one block in an AFS directory |
| 230 | */ |
| 231 | static int afs_dir_iterate_block(struct dir_context *ctx, |
| 232 | union afs_dir_block *block, |
| 233 | unsigned blkoff) |
| 234 | { |
| 235 | union afs_dirent *dire; |
| 236 | unsigned offset, next, curr; |
| 237 | size_t nlen; |
| 238 | int tmp; |
| 239 | |
| 240 | _enter("%u,%x,%p,,",(unsigned)ctx->pos,blkoff,block); |
| 241 | |
| 242 | curr = (ctx->pos - blkoff) / sizeof(union afs_dirent); |
| 243 | |
| 244 | /* walk through the block, an entry at a time */ |
| 245 | for (offset = AFS_DIRENT_PER_BLOCK - block->pagehdr.nentries; |
| 246 | offset < AFS_DIRENT_PER_BLOCK; |
| 247 | offset = next |
| 248 | ) { |
| 249 | next = offset + 1; |
| 250 | |
| 251 | /* skip entries marked unused in the bitmap */ |
| 252 | if (!(block->pagehdr.bitmap[offset / 8] & |
| 253 | (1 << (offset % 8)))) { |
| 254 | _debug("ENT[%Zu.%u]: unused", |
| 255 | blkoff / sizeof(union afs_dir_block), offset); |
| 256 | if (offset >= curr) |
| 257 | ctx->pos = blkoff + |
| 258 | next * sizeof(union afs_dirent); |
| 259 | continue; |
| 260 | } |
| 261 | |
| 262 | /* got a valid entry */ |
| 263 | dire = &block->dirents[offset]; |
| 264 | nlen = strnlen(dire->u.name, |
| 265 | sizeof(*block) - |
| 266 | offset * sizeof(union afs_dirent)); |
| 267 | |
| 268 | _debug("ENT[%Zu.%u]: %s %Zu \"%s\"", |
| 269 | blkoff / sizeof(union afs_dir_block), offset, |
| 270 | (offset < curr ? "skip" : "fill"), |
| 271 | nlen, dire->u.name); |
| 272 | |
| 273 | /* work out where the next possible entry is */ |
| 274 | for (tmp = nlen; tmp > 15; tmp -= sizeof(union afs_dirent)) { |
| 275 | if (next >= AFS_DIRENT_PER_BLOCK) { |
| 276 | _debug("ENT[%Zu.%u]:" |
| 277 | " %u travelled beyond end dir block" |
| 278 | " (len %u/%Zu)", |
| 279 | blkoff / sizeof(union afs_dir_block), |
| 280 | offset, next, tmp, nlen); |
| 281 | return -EIO; |
| 282 | } |
| 283 | if (!(block->pagehdr.bitmap[next / 8] & |
| 284 | (1 << (next % 8)))) { |
| 285 | _debug("ENT[%Zu.%u]:" |
| 286 | " %u unmarked extension (len %u/%Zu)", |
| 287 | blkoff / sizeof(union afs_dir_block), |
| 288 | offset, next, tmp, nlen); |
| 289 | return -EIO; |
| 290 | } |
| 291 | |
| 292 | _debug("ENT[%Zu.%u]: ext %u/%Zu", |
| 293 | blkoff / sizeof(union afs_dir_block), |
| 294 | next, tmp, nlen); |
| 295 | next++; |
| 296 | } |
| 297 | |
| 298 | /* skip if starts before the current position */ |
| 299 | if (offset < curr) |
| 300 | continue; |
| 301 | |
| 302 | /* found the next entry */ |
| 303 | if (!dir_emit(ctx, dire->u.name, nlen, |
| 304 | ntohl(dire->u.vnode), |
| 305 | ctx->actor == afs_lookup_filldir ? |
| 306 | ntohl(dire->u.unique) : DT_UNKNOWN)) { |
| 307 | _leave(" = 0 [full]"); |
| 308 | return 0; |
| 309 | } |
| 310 | |
| 311 | ctx->pos = blkoff + next * sizeof(union afs_dirent); |
| 312 | } |
| 313 | |
| 314 | _leave(" = 1 [more]"); |
| 315 | return 1; |
| 316 | } |
| 317 | |
| 318 | /* |
| 319 | * iterate through the data blob that lists the contents of an AFS directory |
| 320 | */ |
| 321 | static int afs_dir_iterate(struct inode *dir, struct dir_context *ctx, |
| 322 | struct key *key) |
| 323 | { |
| 324 | union afs_dir_block *dblock; |
| 325 | struct afs_dir_page *dbuf; |
| 326 | struct page *page; |
| 327 | unsigned blkoff, limit; |
| 328 | int ret; |
| 329 | |
| 330 | _enter("{%lu},%u,,", dir->i_ino, (unsigned)ctx->pos); |
| 331 | |
| 332 | if (test_bit(AFS_VNODE_DELETED, &AFS_FS_I(dir)->flags)) { |
| 333 | _leave(" = -ESTALE"); |
| 334 | return -ESTALE; |
| 335 | } |
| 336 | |
| 337 | /* round the file position up to the next entry boundary */ |
| 338 | ctx->pos += sizeof(union afs_dirent) - 1; |
| 339 | ctx->pos &= ~(sizeof(union afs_dirent) - 1); |
| 340 | |
| 341 | /* walk through the blocks in sequence */ |
| 342 | ret = 0; |
| 343 | while (ctx->pos < dir->i_size) { |
| 344 | blkoff = ctx->pos & ~(sizeof(union afs_dir_block) - 1); |
| 345 | |
| 346 | /* fetch the appropriate page from the directory */ |
| 347 | page = afs_dir_get_page(dir, blkoff / PAGE_SIZE, key); |
| 348 | if (IS_ERR(page)) { |
| 349 | ret = PTR_ERR(page); |
| 350 | break; |
| 351 | } |
| 352 | |
| 353 | limit = blkoff & ~(PAGE_SIZE - 1); |
| 354 | |
| 355 | dbuf = page_address(page); |
| 356 | |
| 357 | /* deal with the individual blocks stashed on this page */ |
| 358 | do { |
| 359 | dblock = &dbuf->blocks[(blkoff % PAGE_SIZE) / |
| 360 | sizeof(union afs_dir_block)]; |
| 361 | ret = afs_dir_iterate_block(ctx, dblock, blkoff); |
| 362 | if (ret != 1) { |
| 363 | afs_dir_put_page(page); |
| 364 | goto out; |
| 365 | } |
| 366 | |
| 367 | blkoff += sizeof(union afs_dir_block); |
| 368 | |
| 369 | } while (ctx->pos < dir->i_size && blkoff < limit); |
| 370 | |
| 371 | afs_dir_put_page(page); |
| 372 | ret = 0; |
| 373 | } |
| 374 | |
| 375 | out: |
| 376 | _leave(" = %d", ret); |
| 377 | return ret; |
| 378 | } |
| 379 | |
| 380 | /* |
| 381 | * read an AFS directory |
| 382 | */ |
| 383 | static int afs_readdir(struct file *file, struct dir_context *ctx) |
| 384 | { |
| 385 | return afs_dir_iterate(file_inode(file), |
| 386 | ctx, file->private_data); |
| 387 | } |
| 388 | |
| 389 | /* |
| 390 | * search the directory for a name |
| 391 | * - if afs_dir_iterate_block() spots this function, it'll pass the FID |
| 392 | * uniquifier through dtype |
| 393 | */ |
| 394 | static int afs_lookup_filldir(struct dir_context *ctx, const char *name, |
| 395 | int nlen, loff_t fpos, u64 ino, unsigned dtype) |
| 396 | { |
| 397 | struct afs_lookup_cookie *cookie = |
| 398 | container_of(ctx, struct afs_lookup_cookie, ctx); |
| 399 | |
| 400 | _enter("{%s,%u},%s,%u,,%llu,%u", |
| 401 | cookie->name.name, cookie->name.len, name, nlen, |
| 402 | (unsigned long long) ino, dtype); |
| 403 | |
| 404 | /* insanity checks first */ |
| 405 | BUILD_BUG_ON(sizeof(union afs_dir_block) != 2048); |
| 406 | BUILD_BUG_ON(sizeof(union afs_dirent) != 32); |
| 407 | |
| 408 | if (cookie->name.len != nlen || |
| 409 | memcmp(cookie->name.name, name, nlen) != 0) { |
| 410 | _leave(" = 0 [no]"); |
| 411 | return 0; |
| 412 | } |
| 413 | |
| 414 | cookie->fid.vnode = ino; |
| 415 | cookie->fid.unique = dtype; |
| 416 | cookie->found = 1; |
| 417 | |
| 418 | _leave(" = -1 [found]"); |
| 419 | return -1; |
| 420 | } |
| 421 | |
| 422 | /* |
| 423 | * do a lookup in a directory |
| 424 | * - just returns the FID the dentry name maps to if found |
| 425 | */ |
| 426 | static int afs_do_lookup(struct inode *dir, struct dentry *dentry, |
| 427 | struct afs_fid *fid, struct key *key) |
| 428 | { |
| 429 | struct afs_super_info *as = dir->i_sb->s_fs_info; |
| 430 | struct afs_lookup_cookie cookie = { |
| 431 | .ctx.actor = afs_lookup_filldir, |
| 432 | .name = dentry->d_name, |
| 433 | .fid.vid = as->volume->vid |
| 434 | }; |
| 435 | int ret; |
| 436 | |
| 437 | _enter("{%lu},%p{%pd},", dir->i_ino, dentry, dentry); |
| 438 | |
| 439 | /* search the directory */ |
| 440 | ret = afs_dir_iterate(dir, &cookie.ctx, key); |
| 441 | if (ret < 0) { |
| 442 | _leave(" = %d [iter]", ret); |
| 443 | return ret; |
| 444 | } |
| 445 | |
| 446 | ret = -ENOENT; |
| 447 | if (!cookie.found) { |
| 448 | _leave(" = -ENOENT [not found]"); |
| 449 | return -ENOENT; |
| 450 | } |
| 451 | |
| 452 | *fid = cookie.fid; |
| 453 | _leave(" = 0 { vn=%u u=%u }", fid->vnode, fid->unique); |
| 454 | return 0; |
| 455 | } |
| 456 | |
| 457 | /* |
| 458 | * Try to auto mount the mountpoint with pseudo directory, if the autocell |
| 459 | * operation is setted. |
| 460 | */ |
| 461 | static struct inode *afs_try_auto_mntpt( |
| 462 | int ret, struct dentry *dentry, struct inode *dir, struct key *key, |
| 463 | struct afs_fid *fid) |
| 464 | { |
| 465 | const char *devname = dentry->d_name.name; |
| 466 | struct afs_vnode *vnode = AFS_FS_I(dir); |
| 467 | struct inode *inode; |
| 468 | |
| 469 | _enter("%d, %p{%pd}, {%x:%u}, %p", |
| 470 | ret, dentry, dentry, vnode->fid.vid, vnode->fid.vnode, key); |
| 471 | |
| 472 | if (ret != -ENOENT || |
| 473 | !test_bit(AFS_VNODE_AUTOCELL, &vnode->flags)) |
| 474 | goto out; |
| 475 | |
| 476 | inode = afs_iget_autocell(dir, devname, strlen(devname), key); |
| 477 | if (IS_ERR(inode)) { |
| 478 | ret = PTR_ERR(inode); |
| 479 | goto out; |
| 480 | } |
| 481 | |
| 482 | *fid = AFS_FS_I(inode)->fid; |
| 483 | _leave("= %p", inode); |
| 484 | return inode; |
| 485 | |
| 486 | out: |
| 487 | _leave("= %d", ret); |
| 488 | return ERR_PTR(ret); |
| 489 | } |
| 490 | |
| 491 | /* |
| 492 | * look up an entry in a directory |
| 493 | */ |
| 494 | static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry, |
| 495 | unsigned int flags) |
| 496 | { |
| 497 | struct afs_vnode *vnode; |
| 498 | struct afs_fid fid; |
| 499 | struct inode *inode; |
| 500 | struct key *key; |
| 501 | int ret; |
| 502 | |
| 503 | vnode = AFS_FS_I(dir); |
| 504 | |
| 505 | _enter("{%x:%u},%p{%pd},", |
| 506 | vnode->fid.vid, vnode->fid.vnode, dentry, dentry); |
| 507 | |
| 508 | ASSERTCMP(d_inode(dentry), ==, NULL); |
| 509 | |
| 510 | if (dentry->d_name.len >= AFSNAMEMAX) { |
| 511 | _leave(" = -ENAMETOOLONG"); |
| 512 | return ERR_PTR(-ENAMETOOLONG); |
| 513 | } |
| 514 | |
| 515 | if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) { |
| 516 | _leave(" = -ESTALE"); |
| 517 | return ERR_PTR(-ESTALE); |
| 518 | } |
| 519 | |
| 520 | key = afs_request_key(vnode->volume->cell); |
| 521 | if (IS_ERR(key)) { |
| 522 | _leave(" = %ld [key]", PTR_ERR(key)); |
| 523 | return ERR_CAST(key); |
| 524 | } |
| 525 | |
| 526 | ret = afs_validate(vnode, key); |
| 527 | if (ret < 0) { |
| 528 | key_put(key); |
| 529 | _leave(" = %d [val]", ret); |
| 530 | return ERR_PTR(ret); |
| 531 | } |
| 532 | |
| 533 | ret = afs_do_lookup(dir, dentry, &fid, key); |
| 534 | if (ret < 0) { |
| 535 | inode = afs_try_auto_mntpt(ret, dentry, dir, key, &fid); |
| 536 | if (!IS_ERR(inode)) { |
| 537 | key_put(key); |
| 538 | goto success; |
| 539 | } |
| 540 | |
| 541 | ret = PTR_ERR(inode); |
| 542 | key_put(key); |
| 543 | if (ret == -ENOENT) { |
| 544 | d_add(dentry, NULL); |
| 545 | _leave(" = NULL [negative]"); |
| 546 | return NULL; |
| 547 | } |
| 548 | _leave(" = %d [do]", ret); |
| 549 | return ERR_PTR(ret); |
| 550 | } |
| 551 | dentry->d_fsdata = (void *)(unsigned long) vnode->status.data_version; |
| 552 | |
| 553 | /* instantiate the dentry */ |
| 554 | inode = afs_iget(dir->i_sb, key, &fid, NULL, NULL); |
| 555 | key_put(key); |
| 556 | if (IS_ERR(inode)) { |
| 557 | _leave(" = %ld", PTR_ERR(inode)); |
| 558 | return ERR_CAST(inode); |
| 559 | } |
| 560 | |
| 561 | success: |
| 562 | d_add(dentry, inode); |
| 563 | _leave(" = 0 { vn=%u u=%u } -> { ino=%lu v=%u }", |
| 564 | fid.vnode, |
| 565 | fid.unique, |
| 566 | d_inode(dentry)->i_ino, |
| 567 | d_inode(dentry)->i_generation); |
| 568 | |
| 569 | return NULL; |
| 570 | } |
| 571 | |
| 572 | /* |
| 573 | * check that a dentry lookup hit has found a valid entry |
| 574 | * - NOTE! the hit can be a negative hit too, so we can't assume we have an |
| 575 | * inode |
| 576 | */ |
| 577 | static int afs_d_revalidate(struct dentry *dentry, unsigned int flags) |
| 578 | { |
| 579 | struct afs_vnode *vnode, *dir; |
| 580 | struct afs_fid uninitialized_var(fid); |
| 581 | struct dentry *parent; |
| 582 | struct key *key; |
| 583 | void *dir_version; |
| 584 | int ret; |
| 585 | |
| 586 | if (flags & LOOKUP_RCU) |
| 587 | return -ECHILD; |
| 588 | |
| 589 | vnode = AFS_FS_I(d_inode(dentry)); |
| 590 | |
| 591 | if (d_really_is_positive(dentry)) |
| 592 | _enter("{v={%x:%u} n=%pd fl=%lx},", |
| 593 | vnode->fid.vid, vnode->fid.vnode, dentry, |
| 594 | vnode->flags); |
| 595 | else |
| 596 | _enter("{neg n=%pd}", dentry); |
| 597 | |
| 598 | key = afs_request_key(AFS_FS_S(dentry->d_sb)->volume->cell); |
| 599 | if (IS_ERR(key)) |
| 600 | key = NULL; |
| 601 | |
| 602 | /* lock down the parent dentry so we can peer at it */ |
| 603 | parent = dget_parent(dentry); |
| 604 | dir = AFS_FS_I(d_inode(parent)); |
| 605 | |
| 606 | /* validate the parent directory */ |
| 607 | if (test_bit(AFS_VNODE_MODIFIED, &dir->flags)) |
| 608 | afs_validate(dir, key); |
| 609 | |
| 610 | if (test_bit(AFS_VNODE_DELETED, &dir->flags)) { |
| 611 | _debug("%pd: parent dir deleted", dentry); |
| 612 | goto out_bad; |
| 613 | } |
| 614 | |
| 615 | dir_version = (void *) (unsigned long) dir->status.data_version; |
| 616 | if (dentry->d_fsdata == dir_version) |
| 617 | goto out_valid; /* the dir contents are unchanged */ |
| 618 | |
| 619 | _debug("dir modified"); |
| 620 | |
| 621 | /* search the directory for this vnode */ |
| 622 | ret = afs_do_lookup(&dir->vfs_inode, dentry, &fid, key); |
| 623 | switch (ret) { |
| 624 | case 0: |
| 625 | /* the filename maps to something */ |
| 626 | if (d_really_is_negative(dentry)) |
| 627 | goto out_bad; |
| 628 | if (is_bad_inode(d_inode(dentry))) { |
| 629 | printk("kAFS: afs_d_revalidate: %pd2 has bad inode\n", |
| 630 | dentry); |
| 631 | goto out_bad; |
| 632 | } |
| 633 | |
| 634 | /* if the vnode ID has changed, then the dirent points to a |
| 635 | * different file */ |
| 636 | if (fid.vnode != vnode->fid.vnode) { |
| 637 | _debug("%pd: dirent changed [%u != %u]", |
| 638 | dentry, fid.vnode, |
| 639 | vnode->fid.vnode); |
| 640 | goto not_found; |
| 641 | } |
| 642 | |
| 643 | /* if the vnode ID uniqifier has changed, then the file has |
| 644 | * been deleted and replaced, and the original vnode ID has |
| 645 | * been reused */ |
| 646 | if (fid.unique != vnode->fid.unique) { |
| 647 | _debug("%pd: file deleted (uq %u -> %u I:%u)", |
| 648 | dentry, fid.unique, |
| 649 | vnode->fid.unique, |
| 650 | d_inode(dentry)->i_generation); |
| 651 | spin_lock(&vnode->lock); |
| 652 | set_bit(AFS_VNODE_DELETED, &vnode->flags); |
| 653 | spin_unlock(&vnode->lock); |
| 654 | goto not_found; |
| 655 | } |
| 656 | goto out_valid; |
| 657 | |
| 658 | case -ENOENT: |
| 659 | /* the filename is unknown */ |
| 660 | _debug("%pd: dirent not found", dentry); |
| 661 | if (d_really_is_positive(dentry)) |
| 662 | goto not_found; |
| 663 | goto out_valid; |
| 664 | |
| 665 | default: |
| 666 | _debug("failed to iterate dir %pd: %d", |
| 667 | parent, ret); |
| 668 | goto out_bad; |
| 669 | } |
| 670 | |
| 671 | out_valid: |
| 672 | dentry->d_fsdata = dir_version; |
| 673 | dput(parent); |
| 674 | key_put(key); |
| 675 | _leave(" = 1 [valid]"); |
| 676 | return 1; |
| 677 | |
| 678 | /* the dirent, if it exists, now points to a different vnode */ |
| 679 | not_found: |
| 680 | spin_lock(&dentry->d_lock); |
| 681 | dentry->d_flags |= DCACHE_NFSFS_RENAMED; |
| 682 | spin_unlock(&dentry->d_lock); |
| 683 | |
| 684 | out_bad: |
| 685 | _debug("dropping dentry %pd2", dentry); |
| 686 | dput(parent); |
| 687 | key_put(key); |
| 688 | |
| 689 | _leave(" = 0 [bad]"); |
| 690 | return 0; |
| 691 | } |
| 692 | |
| 693 | /* |
| 694 | * allow the VFS to enquire as to whether a dentry should be unhashed (mustn't |
| 695 | * sleep) |
| 696 | * - called from dput() when d_count is going to 0. |
| 697 | * - return 1 to request dentry be unhashed, 0 otherwise |
| 698 | */ |
| 699 | static int afs_d_delete(const struct dentry *dentry) |
| 700 | { |
| 701 | _enter("%pd", dentry); |
| 702 | |
| 703 | if (dentry->d_flags & DCACHE_NFSFS_RENAMED) |
| 704 | goto zap; |
| 705 | |
| 706 | if (d_really_is_positive(dentry) && |
| 707 | (test_bit(AFS_VNODE_DELETED, &AFS_FS_I(d_inode(dentry))->flags) || |
| 708 | test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(d_inode(dentry))->flags))) |
| 709 | goto zap; |
| 710 | |
| 711 | _leave(" = 0 [keep]"); |
| 712 | return 0; |
| 713 | |
| 714 | zap: |
| 715 | _leave(" = 1 [zap]"); |
| 716 | return 1; |
| 717 | } |
| 718 | |
| 719 | /* |
| 720 | * handle dentry release |
| 721 | */ |
| 722 | static void afs_d_release(struct dentry *dentry) |
| 723 | { |
| 724 | _enter("%pd", dentry); |
| 725 | } |
| 726 | |
| 727 | /* |
| 728 | * create a directory on an AFS filesystem |
| 729 | */ |
| 730 | static int afs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) |
| 731 | { |
| 732 | struct afs_file_status status; |
| 733 | struct afs_callback cb; |
| 734 | struct afs_server *server; |
| 735 | struct afs_vnode *dvnode, *vnode; |
| 736 | struct afs_fid fid; |
| 737 | struct inode *inode; |
| 738 | struct key *key; |
| 739 | int ret; |
| 740 | |
| 741 | dvnode = AFS_FS_I(dir); |
| 742 | |
| 743 | _enter("{%x:%u},{%pd},%ho", |
| 744 | dvnode->fid.vid, dvnode->fid.vnode, dentry, mode); |
| 745 | |
| 746 | key = afs_request_key(dvnode->volume->cell); |
| 747 | if (IS_ERR(key)) { |
| 748 | ret = PTR_ERR(key); |
| 749 | goto error; |
| 750 | } |
| 751 | |
| 752 | mode |= S_IFDIR; |
| 753 | ret = afs_vnode_create(dvnode, key, dentry->d_name.name, |
| 754 | mode, &fid, &status, &cb, &server); |
| 755 | if (ret < 0) |
| 756 | goto mkdir_error; |
| 757 | |
| 758 | inode = afs_iget(dir->i_sb, key, &fid, &status, &cb); |
| 759 | if (IS_ERR(inode)) { |
| 760 | /* ENOMEM at a really inconvenient time - just abandon the new |
| 761 | * directory on the server */ |
| 762 | ret = PTR_ERR(inode); |
| 763 | goto iget_error; |
| 764 | } |
| 765 | |
| 766 | /* apply the status report we've got for the new vnode */ |
| 767 | vnode = AFS_FS_I(inode); |
| 768 | spin_lock(&vnode->lock); |
| 769 | vnode->update_cnt++; |
| 770 | spin_unlock(&vnode->lock); |
| 771 | afs_vnode_finalise_status_update(vnode, server); |
| 772 | afs_put_server(server); |
| 773 | |
| 774 | d_instantiate(dentry, inode); |
| 775 | if (d_unhashed(dentry)) { |
| 776 | _debug("not hashed"); |
| 777 | d_rehash(dentry); |
| 778 | } |
| 779 | key_put(key); |
| 780 | _leave(" = 0"); |
| 781 | return 0; |
| 782 | |
| 783 | iget_error: |
| 784 | afs_put_server(server); |
| 785 | mkdir_error: |
| 786 | key_put(key); |
| 787 | error: |
| 788 | d_drop(dentry); |
| 789 | _leave(" = %d", ret); |
| 790 | return ret; |
| 791 | } |
| 792 | |
| 793 | /* |
| 794 | * remove a directory from an AFS filesystem |
| 795 | */ |
| 796 | static int afs_rmdir(struct inode *dir, struct dentry *dentry) |
| 797 | { |
| 798 | struct afs_vnode *dvnode, *vnode; |
| 799 | struct key *key; |
| 800 | int ret; |
| 801 | |
| 802 | dvnode = AFS_FS_I(dir); |
| 803 | |
| 804 | _enter("{%x:%u},{%pd}", |
| 805 | dvnode->fid.vid, dvnode->fid.vnode, dentry); |
| 806 | |
| 807 | key = afs_request_key(dvnode->volume->cell); |
| 808 | if (IS_ERR(key)) { |
| 809 | ret = PTR_ERR(key); |
| 810 | goto error; |
| 811 | } |
| 812 | |
| 813 | ret = afs_vnode_remove(dvnode, key, dentry->d_name.name, true); |
| 814 | if (ret < 0) |
| 815 | goto rmdir_error; |
| 816 | |
| 817 | if (d_really_is_positive(dentry)) { |
| 818 | vnode = AFS_FS_I(d_inode(dentry)); |
| 819 | clear_nlink(&vnode->vfs_inode); |
| 820 | set_bit(AFS_VNODE_DELETED, &vnode->flags); |
| 821 | afs_discard_callback_on_delete(vnode); |
| 822 | } |
| 823 | |
| 824 | key_put(key); |
| 825 | _leave(" = 0"); |
| 826 | return 0; |
| 827 | |
| 828 | rmdir_error: |
| 829 | key_put(key); |
| 830 | error: |
| 831 | _leave(" = %d", ret); |
| 832 | return ret; |
| 833 | } |
| 834 | |
| 835 | /* |
| 836 | * remove a file from an AFS filesystem |
| 837 | */ |
| 838 | static int afs_unlink(struct inode *dir, struct dentry *dentry) |
| 839 | { |
| 840 | struct afs_vnode *dvnode, *vnode; |
| 841 | struct key *key; |
| 842 | int ret; |
| 843 | |
| 844 | dvnode = AFS_FS_I(dir); |
| 845 | |
| 846 | _enter("{%x:%u},{%pd}", |
| 847 | dvnode->fid.vid, dvnode->fid.vnode, dentry); |
| 848 | |
| 849 | ret = -ENAMETOOLONG; |
| 850 | if (dentry->d_name.len >= AFSNAMEMAX) |
| 851 | goto error; |
| 852 | |
| 853 | key = afs_request_key(dvnode->volume->cell); |
| 854 | if (IS_ERR(key)) { |
| 855 | ret = PTR_ERR(key); |
| 856 | goto error; |
| 857 | } |
| 858 | |
| 859 | if (d_really_is_positive(dentry)) { |
| 860 | vnode = AFS_FS_I(d_inode(dentry)); |
| 861 | |
| 862 | /* make sure we have a callback promise on the victim */ |
| 863 | ret = afs_validate(vnode, key); |
| 864 | if (ret < 0) |
| 865 | goto error; |
| 866 | } |
| 867 | |
| 868 | ret = afs_vnode_remove(dvnode, key, dentry->d_name.name, false); |
| 869 | if (ret < 0) |
| 870 | goto remove_error; |
| 871 | |
| 872 | if (d_really_is_positive(dentry)) { |
| 873 | /* if the file wasn't deleted due to excess hard links, the |
| 874 | * fileserver will break the callback promise on the file - if |
| 875 | * it had one - before it returns to us, and if it was deleted, |
| 876 | * it won't |
| 877 | * |
| 878 | * however, if we didn't have a callback promise outstanding, |
| 879 | * or it was outstanding on a different server, then it won't |
| 880 | * break it either... |
| 881 | */ |
| 882 | vnode = AFS_FS_I(d_inode(dentry)); |
| 883 | if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) |
| 884 | _debug("AFS_VNODE_DELETED"); |
| 885 | if (test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags)) |
| 886 | _debug("AFS_VNODE_CB_BROKEN"); |
| 887 | set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags); |
| 888 | ret = afs_validate(vnode, key); |
| 889 | _debug("nlink %d [val %d]", vnode->vfs_inode.i_nlink, ret); |
| 890 | } |
| 891 | |
| 892 | key_put(key); |
| 893 | _leave(" = 0"); |
| 894 | return 0; |
| 895 | |
| 896 | remove_error: |
| 897 | key_put(key); |
| 898 | error: |
| 899 | _leave(" = %d", ret); |
| 900 | return ret; |
| 901 | } |
| 902 | |
| 903 | /* |
| 904 | * create a regular file on an AFS filesystem |
| 905 | */ |
| 906 | static int afs_create(struct inode *dir, struct dentry *dentry, umode_t mode, |
| 907 | bool excl) |
| 908 | { |
| 909 | struct afs_file_status status; |
| 910 | struct afs_callback cb; |
| 911 | struct afs_server *server; |
| 912 | struct afs_vnode *dvnode, *vnode; |
| 913 | struct afs_fid fid; |
| 914 | struct inode *inode; |
| 915 | struct key *key; |
| 916 | int ret; |
| 917 | |
| 918 | dvnode = AFS_FS_I(dir); |
| 919 | |
| 920 | _enter("{%x:%u},{%pd},%ho,", |
| 921 | dvnode->fid.vid, dvnode->fid.vnode, dentry, mode); |
| 922 | |
| 923 | key = afs_request_key(dvnode->volume->cell); |
| 924 | if (IS_ERR(key)) { |
| 925 | ret = PTR_ERR(key); |
| 926 | goto error; |
| 927 | } |
| 928 | |
| 929 | mode |= S_IFREG; |
| 930 | ret = afs_vnode_create(dvnode, key, dentry->d_name.name, |
| 931 | mode, &fid, &status, &cb, &server); |
| 932 | if (ret < 0) |
| 933 | goto create_error; |
| 934 | |
| 935 | inode = afs_iget(dir->i_sb, key, &fid, &status, &cb); |
| 936 | if (IS_ERR(inode)) { |
| 937 | /* ENOMEM at a really inconvenient time - just abandon the new |
| 938 | * directory on the server */ |
| 939 | ret = PTR_ERR(inode); |
| 940 | goto iget_error; |
| 941 | } |
| 942 | |
| 943 | /* apply the status report we've got for the new vnode */ |
| 944 | vnode = AFS_FS_I(inode); |
| 945 | spin_lock(&vnode->lock); |
| 946 | vnode->update_cnt++; |
| 947 | spin_unlock(&vnode->lock); |
| 948 | afs_vnode_finalise_status_update(vnode, server); |
| 949 | afs_put_server(server); |
| 950 | |
| 951 | d_instantiate(dentry, inode); |
| 952 | if (d_unhashed(dentry)) { |
| 953 | _debug("not hashed"); |
| 954 | d_rehash(dentry); |
| 955 | } |
| 956 | key_put(key); |
| 957 | _leave(" = 0"); |
| 958 | return 0; |
| 959 | |
| 960 | iget_error: |
| 961 | afs_put_server(server); |
| 962 | create_error: |
| 963 | key_put(key); |
| 964 | error: |
| 965 | d_drop(dentry); |
| 966 | _leave(" = %d", ret); |
| 967 | return ret; |
| 968 | } |
| 969 | |
| 970 | /* |
| 971 | * create a hard link between files in an AFS filesystem |
| 972 | */ |
| 973 | static int afs_link(struct dentry *from, struct inode *dir, |
| 974 | struct dentry *dentry) |
| 975 | { |
| 976 | struct afs_vnode *dvnode, *vnode; |
| 977 | struct key *key; |
| 978 | int ret; |
| 979 | |
| 980 | vnode = AFS_FS_I(d_inode(from)); |
| 981 | dvnode = AFS_FS_I(dir); |
| 982 | |
| 983 | _enter("{%x:%u},{%x:%u},{%pd}", |
| 984 | vnode->fid.vid, vnode->fid.vnode, |
| 985 | dvnode->fid.vid, dvnode->fid.vnode, |
| 986 | dentry); |
| 987 | |
| 988 | key = afs_request_key(dvnode->volume->cell); |
| 989 | if (IS_ERR(key)) { |
| 990 | ret = PTR_ERR(key); |
| 991 | goto error; |
| 992 | } |
| 993 | |
| 994 | ret = afs_vnode_link(dvnode, vnode, key, dentry->d_name.name); |
| 995 | if (ret < 0) |
| 996 | goto link_error; |
| 997 | |
| 998 | ihold(&vnode->vfs_inode); |
| 999 | d_instantiate(dentry, &vnode->vfs_inode); |
| 1000 | key_put(key); |
| 1001 | _leave(" = 0"); |
| 1002 | return 0; |
| 1003 | |
| 1004 | link_error: |
| 1005 | key_put(key); |
| 1006 | error: |
| 1007 | d_drop(dentry); |
| 1008 | _leave(" = %d", ret); |
| 1009 | return ret; |
| 1010 | } |
| 1011 | |
| 1012 | /* |
| 1013 | * create a symlink in an AFS filesystem |
| 1014 | */ |
| 1015 | static int afs_symlink(struct inode *dir, struct dentry *dentry, |
| 1016 | const char *content) |
| 1017 | { |
| 1018 | struct afs_file_status status; |
| 1019 | struct afs_server *server; |
| 1020 | struct afs_vnode *dvnode, *vnode; |
| 1021 | struct afs_fid fid; |
| 1022 | struct inode *inode; |
| 1023 | struct key *key; |
| 1024 | int ret; |
| 1025 | |
| 1026 | dvnode = AFS_FS_I(dir); |
| 1027 | |
| 1028 | _enter("{%x:%u},{%pd},%s", |
| 1029 | dvnode->fid.vid, dvnode->fid.vnode, dentry, |
| 1030 | content); |
| 1031 | |
| 1032 | ret = -EINVAL; |
| 1033 | if (strlen(content) >= AFSPATHMAX) |
| 1034 | goto error; |
| 1035 | |
| 1036 | key = afs_request_key(dvnode->volume->cell); |
| 1037 | if (IS_ERR(key)) { |
| 1038 | ret = PTR_ERR(key); |
| 1039 | goto error; |
| 1040 | } |
| 1041 | |
| 1042 | ret = afs_vnode_symlink(dvnode, key, dentry->d_name.name, content, |
| 1043 | &fid, &status, &server); |
| 1044 | if (ret < 0) |
| 1045 | goto create_error; |
| 1046 | |
| 1047 | inode = afs_iget(dir->i_sb, key, &fid, &status, NULL); |
| 1048 | if (IS_ERR(inode)) { |
| 1049 | /* ENOMEM at a really inconvenient time - just abandon the new |
| 1050 | * directory on the server */ |
| 1051 | ret = PTR_ERR(inode); |
| 1052 | goto iget_error; |
| 1053 | } |
| 1054 | |
| 1055 | /* apply the status report we've got for the new vnode */ |
| 1056 | vnode = AFS_FS_I(inode); |
| 1057 | spin_lock(&vnode->lock); |
| 1058 | vnode->update_cnt++; |
| 1059 | spin_unlock(&vnode->lock); |
| 1060 | afs_vnode_finalise_status_update(vnode, server); |
| 1061 | afs_put_server(server); |
| 1062 | |
| 1063 | d_instantiate(dentry, inode); |
| 1064 | if (d_unhashed(dentry)) { |
| 1065 | _debug("not hashed"); |
| 1066 | d_rehash(dentry); |
| 1067 | } |
| 1068 | key_put(key); |
| 1069 | _leave(" = 0"); |
| 1070 | return 0; |
| 1071 | |
| 1072 | iget_error: |
| 1073 | afs_put_server(server); |
| 1074 | create_error: |
| 1075 | key_put(key); |
| 1076 | error: |
| 1077 | d_drop(dentry); |
| 1078 | _leave(" = %d", ret); |
| 1079 | return ret; |
| 1080 | } |
| 1081 | |
| 1082 | /* |
| 1083 | * rename a file in an AFS filesystem and/or move it between directories |
| 1084 | */ |
| 1085 | static int afs_rename(struct inode *old_dir, struct dentry *old_dentry, |
| 1086 | struct inode *new_dir, struct dentry *new_dentry) |
| 1087 | { |
| 1088 | struct afs_vnode *orig_dvnode, *new_dvnode, *vnode; |
| 1089 | struct key *key; |
| 1090 | int ret; |
| 1091 | |
| 1092 | vnode = AFS_FS_I(d_inode(old_dentry)); |
| 1093 | orig_dvnode = AFS_FS_I(old_dir); |
| 1094 | new_dvnode = AFS_FS_I(new_dir); |
| 1095 | |
| 1096 | _enter("{%x:%u},{%x:%u},{%x:%u},{%pd}", |
| 1097 | orig_dvnode->fid.vid, orig_dvnode->fid.vnode, |
| 1098 | vnode->fid.vid, vnode->fid.vnode, |
| 1099 | new_dvnode->fid.vid, new_dvnode->fid.vnode, |
| 1100 | new_dentry); |
| 1101 | |
| 1102 | key = afs_request_key(orig_dvnode->volume->cell); |
| 1103 | if (IS_ERR(key)) { |
| 1104 | ret = PTR_ERR(key); |
| 1105 | goto error; |
| 1106 | } |
| 1107 | |
| 1108 | ret = afs_vnode_rename(orig_dvnode, new_dvnode, key, |
| 1109 | old_dentry->d_name.name, |
| 1110 | new_dentry->d_name.name); |
| 1111 | if (ret < 0) |
| 1112 | goto rename_error; |
| 1113 | key_put(key); |
| 1114 | _leave(" = 0"); |
| 1115 | return 0; |
| 1116 | |
| 1117 | rename_error: |
| 1118 | key_put(key); |
| 1119 | error: |
| 1120 | d_drop(new_dentry); |
| 1121 | _leave(" = %d", ret); |
| 1122 | return ret; |
| 1123 | } |