Dave Chinner | 4a8af27 | 2013-08-12 20:49:36 +1000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright (c) 2000-2005 Silicon Graphics, Inc. |
| 3 | * Copyright (c) 2013 Red Hat, Inc. |
| 4 | * All Rights Reserved. |
| 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 as |
| 8 | * published by the Free Software Foundation. |
| 9 | * |
| 10 | * This program is distributed in the hope that it would be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License |
| 16 | * along with this program; if not, write the Free Software Foundation, |
| 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| 18 | */ |
| 19 | #include "xfs.h" |
| 20 | #include "xfs_fs.h" |
| 21 | #include "xfs_types.h" |
| 22 | #include "xfs_bit.h" |
| 23 | #include "xfs_log.h" |
| 24 | #include "xfs_trans.h" |
| 25 | #include "xfs_sb.h" |
| 26 | #include "xfs_ag.h" |
| 27 | #include "xfs_mount.h" |
| 28 | #include "xfs_da_btree.h" |
| 29 | #include "xfs_bmap_btree.h" |
| 30 | #include "xfs_dinode.h" |
| 31 | #include "xfs_inode.h" |
| 32 | #include "xfs_dir2_format.h" |
| 33 | #include "xfs_dir2_priv.h" |
| 34 | #include "xfs_error.h" |
| 35 | #include "xfs_trace.h" |
| 36 | #include "xfs_bmap.h" |
| 37 | |
| 38 | STATIC int |
| 39 | xfs_dir2_sf_getdents( |
| 40 | xfs_inode_t *dp, /* incore directory inode */ |
| 41 | struct dir_context *ctx) |
| 42 | { |
| 43 | int i; /* shortform entry number */ |
| 44 | xfs_mount_t *mp; /* filesystem mount point */ |
| 45 | xfs_dir2_dataptr_t off; /* current entry's offset */ |
| 46 | xfs_dir2_sf_entry_t *sfep; /* shortform directory entry */ |
| 47 | xfs_dir2_sf_hdr_t *sfp; /* shortform structure */ |
| 48 | xfs_dir2_dataptr_t dot_offset; |
| 49 | xfs_dir2_dataptr_t dotdot_offset; |
| 50 | xfs_ino_t ino; |
| 51 | |
| 52 | mp = dp->i_mount; |
| 53 | |
| 54 | ASSERT(dp->i_df.if_flags & XFS_IFINLINE); |
| 55 | /* |
| 56 | * Give up if the directory is way too short. |
| 57 | */ |
| 58 | if (dp->i_d.di_size < offsetof(xfs_dir2_sf_hdr_t, parent)) { |
| 59 | ASSERT(XFS_FORCED_SHUTDOWN(mp)); |
| 60 | return XFS_ERROR(EIO); |
| 61 | } |
| 62 | |
| 63 | ASSERT(dp->i_df.if_bytes == dp->i_d.di_size); |
| 64 | ASSERT(dp->i_df.if_u1.if_data != NULL); |
| 65 | |
| 66 | sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data; |
| 67 | |
| 68 | ASSERT(dp->i_d.di_size >= xfs_dir2_sf_hdr_size(sfp->i8count)); |
| 69 | |
| 70 | /* |
| 71 | * If the block number in the offset is out of range, we're done. |
| 72 | */ |
| 73 | if (xfs_dir2_dataptr_to_db(mp, ctx->pos) > mp->m_dirdatablk) |
| 74 | return 0; |
| 75 | |
| 76 | /* |
| 77 | * Precalculate offsets for . and .. as we will always need them. |
| 78 | * |
| 79 | * XXX(hch): the second argument is sometimes 0 and sometimes |
| 80 | * mp->m_dirdatablk. |
| 81 | */ |
| 82 | dot_offset = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk, |
| 83 | XFS_DIR3_DATA_DOT_OFFSET(mp)); |
| 84 | dotdot_offset = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk, |
| 85 | XFS_DIR3_DATA_DOTDOT_OFFSET(mp)); |
| 86 | |
| 87 | /* |
| 88 | * Put . entry unless we're starting past it. |
| 89 | */ |
| 90 | if (ctx->pos <= dot_offset) { |
| 91 | ctx->pos = dot_offset & 0x7fffffff; |
| 92 | if (!dir_emit(ctx, ".", 1, dp->i_ino, DT_DIR)) |
| 93 | return 0; |
| 94 | } |
| 95 | |
| 96 | /* |
| 97 | * Put .. entry unless we're starting past it. |
| 98 | */ |
| 99 | if (ctx->pos <= dotdot_offset) { |
| 100 | ino = xfs_dir2_sf_get_parent_ino(sfp); |
| 101 | ctx->pos = dotdot_offset & 0x7fffffff; |
| 102 | if (!dir_emit(ctx, "..", 2, ino, DT_DIR)) |
| 103 | return 0; |
| 104 | } |
| 105 | |
| 106 | /* |
| 107 | * Loop while there are more entries and put'ing works. |
| 108 | */ |
| 109 | sfep = xfs_dir2_sf_firstentry(sfp); |
| 110 | for (i = 0; i < sfp->count; i++) { |
| 111 | off = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk, |
| 112 | xfs_dir2_sf_get_offset(sfep)); |
| 113 | |
| 114 | if (ctx->pos > off) { |
| 115 | sfep = xfs_dir2_sf_nextentry(sfp, sfep); |
| 116 | continue; |
| 117 | } |
| 118 | |
| 119 | ino = xfs_dir2_sfe_get_ino(sfp, sfep); |
| 120 | ctx->pos = off & 0x7fffffff; |
| 121 | if (!dir_emit(ctx, (char *)sfep->name, sfep->namelen, |
| 122 | ino, DT_UNKNOWN)) |
| 123 | return 0; |
| 124 | sfep = xfs_dir2_sf_nextentry(sfp, sfep); |
| 125 | } |
| 126 | |
| 127 | ctx->pos = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk + 1, 0) & |
| 128 | 0x7fffffff; |
| 129 | return 0; |
| 130 | } |
| 131 | |
| 132 | /* |
| 133 | * Readdir for block directories. |
| 134 | */ |
| 135 | STATIC int |
| 136 | xfs_dir2_block_getdents( |
| 137 | xfs_inode_t *dp, /* incore inode */ |
| 138 | struct dir_context *ctx) |
| 139 | { |
| 140 | xfs_dir2_data_hdr_t *hdr; /* block header */ |
| 141 | struct xfs_buf *bp; /* buffer for block */ |
| 142 | xfs_dir2_block_tail_t *btp; /* block tail */ |
| 143 | xfs_dir2_data_entry_t *dep; /* block data entry */ |
| 144 | xfs_dir2_data_unused_t *dup; /* block unused entry */ |
| 145 | char *endptr; /* end of the data entries */ |
| 146 | int error; /* error return value */ |
| 147 | xfs_mount_t *mp; /* filesystem mount point */ |
| 148 | char *ptr; /* current data entry */ |
| 149 | int wantoff; /* starting block offset */ |
| 150 | xfs_off_t cook; |
| 151 | |
| 152 | mp = dp->i_mount; |
| 153 | /* |
| 154 | * If the block number in the offset is out of range, we're done. |
| 155 | */ |
| 156 | if (xfs_dir2_dataptr_to_db(mp, ctx->pos) > mp->m_dirdatablk) |
| 157 | return 0; |
| 158 | |
| 159 | error = xfs_dir3_block_read(NULL, dp, &bp); |
| 160 | if (error) |
| 161 | return error; |
| 162 | |
| 163 | /* |
| 164 | * Extract the byte offset we start at from the seek pointer. |
| 165 | * We'll skip entries before this. |
| 166 | */ |
| 167 | wantoff = xfs_dir2_dataptr_to_off(mp, ctx->pos); |
| 168 | hdr = bp->b_addr; |
| 169 | xfs_dir3_data_check(dp, bp); |
| 170 | /* |
| 171 | * Set up values for the loop. |
| 172 | */ |
| 173 | btp = xfs_dir2_block_tail_p(mp, hdr); |
| 174 | ptr = (char *)xfs_dir3_data_entry_p(hdr); |
| 175 | endptr = (char *)xfs_dir2_block_leaf_p(btp); |
| 176 | |
| 177 | /* |
| 178 | * Loop over the data portion of the block. |
| 179 | * Each object is a real entry (dep) or an unused one (dup). |
| 180 | */ |
| 181 | while (ptr < endptr) { |
| 182 | dup = (xfs_dir2_data_unused_t *)ptr; |
| 183 | /* |
| 184 | * Unused, skip it. |
| 185 | */ |
| 186 | if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) { |
| 187 | ptr += be16_to_cpu(dup->length); |
| 188 | continue; |
| 189 | } |
| 190 | |
| 191 | dep = (xfs_dir2_data_entry_t *)ptr; |
| 192 | |
| 193 | /* |
| 194 | * Bump pointer for the next iteration. |
| 195 | */ |
| 196 | ptr += xfs_dir2_data_entsize(dep->namelen); |
| 197 | /* |
| 198 | * The entry is before the desired starting point, skip it. |
| 199 | */ |
| 200 | if ((char *)dep - (char *)hdr < wantoff) |
| 201 | continue; |
| 202 | |
| 203 | cook = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk, |
| 204 | (char *)dep - (char *)hdr); |
| 205 | |
| 206 | ctx->pos = cook & 0x7fffffff; |
| 207 | /* |
| 208 | * If it didn't fit, set the final offset to here & return. |
| 209 | */ |
| 210 | if (!dir_emit(ctx, (char *)dep->name, dep->namelen, |
| 211 | be64_to_cpu(dep->inumber), DT_UNKNOWN)) { |
| 212 | xfs_trans_brelse(NULL, bp); |
| 213 | return 0; |
| 214 | } |
| 215 | } |
| 216 | |
| 217 | /* |
| 218 | * Reached the end of the block. |
| 219 | * Set the offset to a non-existent block 1 and return. |
| 220 | */ |
| 221 | ctx->pos = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk + 1, 0) & |
| 222 | 0x7fffffff; |
| 223 | xfs_trans_brelse(NULL, bp); |
| 224 | return 0; |
| 225 | } |
| 226 | |
| 227 | struct xfs_dir2_leaf_map_info { |
| 228 | xfs_extlen_t map_blocks; /* number of fsbs in map */ |
| 229 | xfs_dablk_t map_off; /* last mapped file offset */ |
| 230 | int map_size; /* total entries in *map */ |
| 231 | int map_valid; /* valid entries in *map */ |
| 232 | int nmap; /* mappings to ask xfs_bmapi */ |
| 233 | xfs_dir2_db_t curdb; /* db for current block */ |
| 234 | int ra_current; /* number of read-ahead blks */ |
| 235 | int ra_index; /* *map index for read-ahead */ |
| 236 | int ra_offset; /* map entry offset for ra */ |
| 237 | int ra_want; /* readahead count wanted */ |
| 238 | struct xfs_bmbt_irec map[]; /* map vector for blocks */ |
| 239 | }; |
| 240 | |
| 241 | STATIC int |
| 242 | xfs_dir2_leaf_readbuf( |
| 243 | struct xfs_inode *dp, |
| 244 | size_t bufsize, |
| 245 | struct xfs_dir2_leaf_map_info *mip, |
| 246 | xfs_dir2_off_t *curoff, |
| 247 | struct xfs_buf **bpp) |
| 248 | { |
| 249 | struct xfs_mount *mp = dp->i_mount; |
| 250 | struct xfs_buf *bp = *bpp; |
| 251 | struct xfs_bmbt_irec *map = mip->map; |
| 252 | struct blk_plug plug; |
| 253 | int error = 0; |
| 254 | int length; |
| 255 | int i; |
| 256 | int j; |
| 257 | |
| 258 | /* |
| 259 | * If we have a buffer, we need to release it and |
| 260 | * take it out of the mapping. |
| 261 | */ |
| 262 | |
| 263 | if (bp) { |
| 264 | xfs_trans_brelse(NULL, bp); |
| 265 | bp = NULL; |
| 266 | mip->map_blocks -= mp->m_dirblkfsbs; |
| 267 | /* |
| 268 | * Loop to get rid of the extents for the |
| 269 | * directory block. |
| 270 | */ |
| 271 | for (i = mp->m_dirblkfsbs; i > 0; ) { |
| 272 | j = min_t(int, map->br_blockcount, i); |
| 273 | map->br_blockcount -= j; |
| 274 | map->br_startblock += j; |
| 275 | map->br_startoff += j; |
| 276 | /* |
| 277 | * If mapping is done, pitch it from |
| 278 | * the table. |
| 279 | */ |
| 280 | if (!map->br_blockcount && --mip->map_valid) |
| 281 | memmove(&map[0], &map[1], |
| 282 | sizeof(map[0]) * mip->map_valid); |
| 283 | i -= j; |
| 284 | } |
| 285 | } |
| 286 | |
| 287 | /* |
| 288 | * Recalculate the readahead blocks wanted. |
| 289 | */ |
| 290 | mip->ra_want = howmany(bufsize + mp->m_dirblksize, |
| 291 | mp->m_sb.sb_blocksize) - 1; |
| 292 | ASSERT(mip->ra_want >= 0); |
| 293 | |
| 294 | /* |
| 295 | * If we don't have as many as we want, and we haven't |
| 296 | * run out of data blocks, get some more mappings. |
| 297 | */ |
| 298 | if (1 + mip->ra_want > mip->map_blocks && |
| 299 | mip->map_off < xfs_dir2_byte_to_da(mp, XFS_DIR2_LEAF_OFFSET)) { |
| 300 | /* |
| 301 | * Get more bmaps, fill in after the ones |
| 302 | * we already have in the table. |
| 303 | */ |
| 304 | mip->nmap = mip->map_size - mip->map_valid; |
| 305 | error = xfs_bmapi_read(dp, mip->map_off, |
| 306 | xfs_dir2_byte_to_da(mp, XFS_DIR2_LEAF_OFFSET) - |
| 307 | mip->map_off, |
| 308 | &map[mip->map_valid], &mip->nmap, 0); |
| 309 | |
| 310 | /* |
| 311 | * Don't know if we should ignore this or try to return an |
| 312 | * error. The trouble with returning errors is that readdir |
| 313 | * will just stop without actually passing the error through. |
| 314 | */ |
| 315 | if (error) |
| 316 | goto out; /* XXX */ |
| 317 | |
| 318 | /* |
| 319 | * If we got all the mappings we asked for, set the final map |
| 320 | * offset based on the last bmap value received. Otherwise, |
| 321 | * we've reached the end. |
| 322 | */ |
| 323 | if (mip->nmap == mip->map_size - mip->map_valid) { |
| 324 | i = mip->map_valid + mip->nmap - 1; |
| 325 | mip->map_off = map[i].br_startoff + map[i].br_blockcount; |
| 326 | } else |
| 327 | mip->map_off = xfs_dir2_byte_to_da(mp, |
| 328 | XFS_DIR2_LEAF_OFFSET); |
| 329 | |
| 330 | /* |
| 331 | * Look for holes in the mapping, and eliminate them. Count up |
| 332 | * the valid blocks. |
| 333 | */ |
| 334 | for (i = mip->map_valid; i < mip->map_valid + mip->nmap; ) { |
| 335 | if (map[i].br_startblock == HOLESTARTBLOCK) { |
| 336 | mip->nmap--; |
| 337 | length = mip->map_valid + mip->nmap - i; |
| 338 | if (length) |
| 339 | memmove(&map[i], &map[i + 1], |
| 340 | sizeof(map[i]) * length); |
| 341 | } else { |
| 342 | mip->map_blocks += map[i].br_blockcount; |
| 343 | i++; |
| 344 | } |
| 345 | } |
| 346 | mip->map_valid += mip->nmap; |
| 347 | } |
| 348 | |
| 349 | /* |
| 350 | * No valid mappings, so no more data blocks. |
| 351 | */ |
| 352 | if (!mip->map_valid) { |
| 353 | *curoff = xfs_dir2_da_to_byte(mp, mip->map_off); |
| 354 | goto out; |
| 355 | } |
| 356 | |
| 357 | /* |
| 358 | * Read the directory block starting at the first mapping. |
| 359 | */ |
| 360 | mip->curdb = xfs_dir2_da_to_db(mp, map->br_startoff); |
| 361 | error = xfs_dir3_data_read(NULL, dp, map->br_startoff, |
| 362 | map->br_blockcount >= mp->m_dirblkfsbs ? |
| 363 | XFS_FSB_TO_DADDR(mp, map->br_startblock) : -1, &bp); |
| 364 | |
| 365 | /* |
| 366 | * Should just skip over the data block instead of giving up. |
| 367 | */ |
| 368 | if (error) |
| 369 | goto out; /* XXX */ |
| 370 | |
| 371 | /* |
| 372 | * Adjust the current amount of read-ahead: we just read a block that |
| 373 | * was previously ra. |
| 374 | */ |
| 375 | if (mip->ra_current) |
| 376 | mip->ra_current -= mp->m_dirblkfsbs; |
| 377 | |
| 378 | /* |
| 379 | * Do we need more readahead? |
| 380 | */ |
| 381 | blk_start_plug(&plug); |
| 382 | for (mip->ra_index = mip->ra_offset = i = 0; |
| 383 | mip->ra_want > mip->ra_current && i < mip->map_blocks; |
| 384 | i += mp->m_dirblkfsbs) { |
| 385 | ASSERT(mip->ra_index < mip->map_valid); |
| 386 | /* |
| 387 | * Read-ahead a contiguous directory block. |
| 388 | */ |
| 389 | if (i > mip->ra_current && |
| 390 | map[mip->ra_index].br_blockcount >= mp->m_dirblkfsbs) { |
| 391 | xfs_dir3_data_readahead(NULL, dp, |
| 392 | map[mip->ra_index].br_startoff + mip->ra_offset, |
| 393 | XFS_FSB_TO_DADDR(mp, |
| 394 | map[mip->ra_index].br_startblock + |
| 395 | mip->ra_offset)); |
| 396 | mip->ra_current = i; |
| 397 | } |
| 398 | |
| 399 | /* |
| 400 | * Read-ahead a non-contiguous directory block. This doesn't |
| 401 | * use our mapping, but this is a very rare case. |
| 402 | */ |
| 403 | else if (i > mip->ra_current) { |
| 404 | xfs_dir3_data_readahead(NULL, dp, |
| 405 | map[mip->ra_index].br_startoff + |
| 406 | mip->ra_offset, -1); |
| 407 | mip->ra_current = i; |
| 408 | } |
| 409 | |
| 410 | /* |
| 411 | * Advance offset through the mapping table. |
| 412 | */ |
| 413 | for (j = 0; j < mp->m_dirblkfsbs; j++) { |
| 414 | /* |
| 415 | * The rest of this extent but not more than a dir |
| 416 | * block. |
| 417 | */ |
| 418 | length = min_t(int, mp->m_dirblkfsbs, |
| 419 | map[mip->ra_index].br_blockcount - |
| 420 | mip->ra_offset); |
| 421 | j += length; |
| 422 | mip->ra_offset += length; |
| 423 | |
| 424 | /* |
| 425 | * Advance to the next mapping if this one is used up. |
| 426 | */ |
| 427 | if (mip->ra_offset == map[mip->ra_index].br_blockcount) { |
| 428 | mip->ra_offset = 0; |
| 429 | mip->ra_index++; |
| 430 | } |
| 431 | } |
| 432 | } |
| 433 | blk_finish_plug(&plug); |
| 434 | |
| 435 | out: |
| 436 | *bpp = bp; |
| 437 | return error; |
| 438 | } |
| 439 | |
| 440 | /* |
| 441 | * Getdents (readdir) for leaf and node directories. |
| 442 | * This reads the data blocks only, so is the same for both forms. |
| 443 | */ |
| 444 | STATIC int |
| 445 | xfs_dir2_leaf_getdents( |
| 446 | xfs_inode_t *dp, /* incore directory inode */ |
| 447 | struct dir_context *ctx, |
| 448 | size_t bufsize) |
| 449 | { |
| 450 | struct xfs_buf *bp = NULL; /* data block buffer */ |
| 451 | xfs_dir2_data_hdr_t *hdr; /* data block header */ |
| 452 | xfs_dir2_data_entry_t *dep; /* data entry */ |
| 453 | xfs_dir2_data_unused_t *dup; /* unused entry */ |
| 454 | int error = 0; /* error return value */ |
| 455 | int length; /* temporary length value */ |
| 456 | xfs_mount_t *mp; /* filesystem mount point */ |
| 457 | int byteoff; /* offset in current block */ |
| 458 | xfs_dir2_off_t curoff; /* current overall offset */ |
| 459 | xfs_dir2_off_t newoff; /* new curoff after new blk */ |
| 460 | char *ptr = NULL; /* pointer to current data */ |
| 461 | struct xfs_dir2_leaf_map_info *map_info; |
| 462 | |
| 463 | /* |
| 464 | * If the offset is at or past the largest allowed value, |
| 465 | * give up right away. |
| 466 | */ |
| 467 | if (ctx->pos >= XFS_DIR2_MAX_DATAPTR) |
| 468 | return 0; |
| 469 | |
| 470 | mp = dp->i_mount; |
| 471 | |
| 472 | /* |
| 473 | * Set up to bmap a number of blocks based on the caller's |
| 474 | * buffer size, the directory block size, and the filesystem |
| 475 | * block size. |
| 476 | */ |
| 477 | length = howmany(bufsize + mp->m_dirblksize, |
| 478 | mp->m_sb.sb_blocksize); |
| 479 | map_info = kmem_zalloc(offsetof(struct xfs_dir2_leaf_map_info, map) + |
| 480 | (length * sizeof(struct xfs_bmbt_irec)), |
| 481 | KM_SLEEP | KM_NOFS); |
| 482 | map_info->map_size = length; |
| 483 | |
| 484 | /* |
| 485 | * Inside the loop we keep the main offset value as a byte offset |
| 486 | * in the directory file. |
| 487 | */ |
| 488 | curoff = xfs_dir2_dataptr_to_byte(mp, ctx->pos); |
| 489 | |
| 490 | /* |
| 491 | * Force this conversion through db so we truncate the offset |
| 492 | * down to get the start of the data block. |
| 493 | */ |
| 494 | map_info->map_off = xfs_dir2_db_to_da(mp, |
| 495 | xfs_dir2_byte_to_db(mp, curoff)); |
| 496 | |
| 497 | /* |
| 498 | * Loop over directory entries until we reach the end offset. |
| 499 | * Get more blocks and readahead as necessary. |
| 500 | */ |
| 501 | while (curoff < XFS_DIR2_LEAF_OFFSET) { |
| 502 | /* |
| 503 | * If we have no buffer, or we're off the end of the |
| 504 | * current buffer, need to get another one. |
| 505 | */ |
| 506 | if (!bp || ptr >= (char *)bp->b_addr + mp->m_dirblksize) { |
| 507 | |
| 508 | error = xfs_dir2_leaf_readbuf(dp, bufsize, map_info, |
| 509 | &curoff, &bp); |
| 510 | if (error || !map_info->map_valid) |
| 511 | break; |
| 512 | |
| 513 | /* |
| 514 | * Having done a read, we need to set a new offset. |
| 515 | */ |
| 516 | newoff = xfs_dir2_db_off_to_byte(mp, map_info->curdb, 0); |
| 517 | /* |
| 518 | * Start of the current block. |
| 519 | */ |
| 520 | if (curoff < newoff) |
| 521 | curoff = newoff; |
| 522 | /* |
| 523 | * Make sure we're in the right block. |
| 524 | */ |
| 525 | else if (curoff > newoff) |
| 526 | ASSERT(xfs_dir2_byte_to_db(mp, curoff) == |
| 527 | map_info->curdb); |
| 528 | hdr = bp->b_addr; |
| 529 | xfs_dir3_data_check(dp, bp); |
| 530 | /* |
| 531 | * Find our position in the block. |
| 532 | */ |
| 533 | ptr = (char *)xfs_dir3_data_entry_p(hdr); |
| 534 | byteoff = xfs_dir2_byte_to_off(mp, curoff); |
| 535 | /* |
| 536 | * Skip past the header. |
| 537 | */ |
| 538 | if (byteoff == 0) |
| 539 | curoff += xfs_dir3_data_entry_offset(hdr); |
| 540 | /* |
| 541 | * Skip past entries until we reach our offset. |
| 542 | */ |
| 543 | else { |
| 544 | while ((char *)ptr - (char *)hdr < byteoff) { |
| 545 | dup = (xfs_dir2_data_unused_t *)ptr; |
| 546 | |
| 547 | if (be16_to_cpu(dup->freetag) |
| 548 | == XFS_DIR2_DATA_FREE_TAG) { |
| 549 | |
| 550 | length = be16_to_cpu(dup->length); |
| 551 | ptr += length; |
| 552 | continue; |
| 553 | } |
| 554 | dep = (xfs_dir2_data_entry_t *)ptr; |
| 555 | length = |
| 556 | xfs_dir2_data_entsize(dep->namelen); |
| 557 | ptr += length; |
| 558 | } |
| 559 | /* |
| 560 | * Now set our real offset. |
| 561 | */ |
| 562 | curoff = |
| 563 | xfs_dir2_db_off_to_byte(mp, |
| 564 | xfs_dir2_byte_to_db(mp, curoff), |
| 565 | (char *)ptr - (char *)hdr); |
| 566 | if (ptr >= (char *)hdr + mp->m_dirblksize) { |
| 567 | continue; |
| 568 | } |
| 569 | } |
| 570 | } |
| 571 | /* |
| 572 | * We have a pointer to an entry. |
| 573 | * Is it a live one? |
| 574 | */ |
| 575 | dup = (xfs_dir2_data_unused_t *)ptr; |
| 576 | /* |
| 577 | * No, it's unused, skip over it. |
| 578 | */ |
| 579 | if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) { |
| 580 | length = be16_to_cpu(dup->length); |
| 581 | ptr += length; |
| 582 | curoff += length; |
| 583 | continue; |
| 584 | } |
| 585 | |
| 586 | dep = (xfs_dir2_data_entry_t *)ptr; |
| 587 | length = xfs_dir2_data_entsize(dep->namelen); |
| 588 | |
| 589 | ctx->pos = xfs_dir2_byte_to_dataptr(mp, curoff) & 0x7fffffff; |
| 590 | if (!dir_emit(ctx, (char *)dep->name, dep->namelen, |
| 591 | be64_to_cpu(dep->inumber), DT_UNKNOWN)) |
| 592 | break; |
| 593 | |
| 594 | /* |
| 595 | * Advance to next entry in the block. |
| 596 | */ |
| 597 | ptr += length; |
| 598 | curoff += length; |
| 599 | /* bufsize may have just been a guess; don't go negative */ |
| 600 | bufsize = bufsize > length ? bufsize - length : 0; |
| 601 | } |
| 602 | |
| 603 | /* |
| 604 | * All done. Set output offset value to current offset. |
| 605 | */ |
| 606 | if (curoff > xfs_dir2_dataptr_to_byte(mp, XFS_DIR2_MAX_DATAPTR)) |
| 607 | ctx->pos = XFS_DIR2_MAX_DATAPTR & 0x7fffffff; |
| 608 | else |
| 609 | ctx->pos = xfs_dir2_byte_to_dataptr(mp, curoff) & 0x7fffffff; |
| 610 | kmem_free(map_info); |
| 611 | if (bp) |
| 612 | xfs_trans_brelse(NULL, bp); |
| 613 | return error; |
| 614 | } |
| 615 | |
| 616 | /* |
| 617 | * Read a directory. |
| 618 | */ |
| 619 | int |
| 620 | xfs_readdir( |
| 621 | xfs_inode_t *dp, |
| 622 | struct dir_context *ctx, |
| 623 | size_t bufsize) |
| 624 | { |
| 625 | int rval; /* return value */ |
| 626 | int v; /* type-checking value */ |
| 627 | |
| 628 | trace_xfs_readdir(dp); |
| 629 | |
| 630 | if (XFS_FORCED_SHUTDOWN(dp->i_mount)) |
| 631 | return XFS_ERROR(EIO); |
| 632 | |
| 633 | ASSERT(S_ISDIR(dp->i_d.di_mode)); |
| 634 | XFS_STATS_INC(xs_dir_getdents); |
| 635 | |
| 636 | if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) |
| 637 | rval = xfs_dir2_sf_getdents(dp, ctx); |
| 638 | else if ((rval = xfs_dir2_isblock(NULL, dp, &v))) |
| 639 | ; |
| 640 | else if (v) |
| 641 | rval = xfs_dir2_block_getdents(dp, ctx); |
| 642 | else |
| 643 | rval = xfs_dir2_leaf_getdents(dp, ctx, bufsize); |
| 644 | return rval; |
| 645 | } |