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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 | } |