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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_format.h" | |
22 | #include "xfs_log_format.h" | |
23 | #include "xfs_trans_resv.h" | |
24 | #include "xfs_bit.h" | |
25 | #include "xfs_mount.h" | |
26 | #include "xfs_da_format.h" | |
27 | #include "xfs_da_btree.h" | |
28 | #include "xfs_inode.h" | |
29 | #include "xfs_dir2.h" | |
30 | #include "xfs_dir2_priv.h" | |
31 | #include "xfs_error.h" | |
32 | #include "xfs_trace.h" | |
33 | #include "xfs_bmap.h" | |
34 | #include "xfs_trans.h" | |
35 | ||
36 | /* | |
37 | * Directory file type support functions | |
38 | */ | |
39 | static unsigned char xfs_dir3_filetype_table[] = { | |
40 | DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, | |
41 | DT_FIFO, DT_SOCK, DT_LNK, DT_WHT, | |
42 | }; | |
43 | ||
44 | static unsigned char | |
45 | xfs_dir3_get_dtype( | |
46 | struct xfs_mount *mp, | |
47 | __uint8_t filetype) | |
48 | { | |
49 | if (!xfs_sb_version_hasftype(&mp->m_sb)) | |
50 | return DT_UNKNOWN; | |
51 | ||
52 | if (filetype >= XFS_DIR3_FT_MAX) | |
53 | return DT_UNKNOWN; | |
54 | ||
55 | return xfs_dir3_filetype_table[filetype]; | |
56 | } | |
57 | ||
58 | STATIC int | |
59 | xfs_dir2_sf_getdents( | |
60 | struct xfs_da_args *args, | |
61 | struct dir_context *ctx) | |
62 | { | |
63 | int i; /* shortform entry number */ | |
64 | struct xfs_inode *dp = args->dp; /* incore directory inode */ | |
65 | xfs_dir2_dataptr_t off; /* current entry's offset */ | |
66 | xfs_dir2_sf_entry_t *sfep; /* shortform directory entry */ | |
67 | xfs_dir2_sf_hdr_t *sfp; /* shortform structure */ | |
68 | xfs_dir2_dataptr_t dot_offset; | |
69 | xfs_dir2_dataptr_t dotdot_offset; | |
70 | xfs_ino_t ino; | |
71 | struct xfs_da_geometry *geo = args->geo; | |
72 | ||
73 | ASSERT(dp->i_df.if_flags & XFS_IFINLINE); | |
74 | /* | |
75 | * Give up if the directory is way too short. | |
76 | */ | |
77 | if (dp->i_d.di_size < offsetof(xfs_dir2_sf_hdr_t, parent)) { | |
78 | ASSERT(XFS_FORCED_SHUTDOWN(dp->i_mount)); | |
79 | return -EIO; | |
80 | } | |
81 | ||
82 | ASSERT(dp->i_df.if_bytes == dp->i_d.di_size); | |
83 | ASSERT(dp->i_df.if_u1.if_data != NULL); | |
84 | ||
85 | sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data; | |
86 | ||
87 | if (dp->i_d.di_size < xfs_dir2_sf_hdr_size(sfp->i8count)) | |
88 | return -EFSCORRUPTED; | |
89 | ||
90 | /* | |
91 | * If the block number in the offset is out of range, we're done. | |
92 | */ | |
93 | if (xfs_dir2_dataptr_to_db(geo, ctx->pos) > geo->datablk) | |
94 | return 0; | |
95 | ||
96 | /* | |
97 | * Precalculate offsets for . and .. as we will always need them. | |
98 | * | |
99 | * XXX(hch): the second argument is sometimes 0 and sometimes | |
100 | * geo->datablk | |
101 | */ | |
102 | dot_offset = xfs_dir2_db_off_to_dataptr(geo, geo->datablk, | |
103 | dp->d_ops->data_dot_offset); | |
104 | dotdot_offset = xfs_dir2_db_off_to_dataptr(geo, geo->datablk, | |
105 | dp->d_ops->data_dotdot_offset); | |
106 | ||
107 | /* | |
108 | * Put . entry unless we're starting past it. | |
109 | */ | |
110 | if (ctx->pos <= dot_offset) { | |
111 | ctx->pos = dot_offset & 0x7fffffff; | |
112 | if (!dir_emit(ctx, ".", 1, dp->i_ino, DT_DIR)) | |
113 | return 0; | |
114 | } | |
115 | ||
116 | /* | |
117 | * Put .. entry unless we're starting past it. | |
118 | */ | |
119 | if (ctx->pos <= dotdot_offset) { | |
120 | ino = dp->d_ops->sf_get_parent_ino(sfp); | |
121 | ctx->pos = dotdot_offset & 0x7fffffff; | |
122 | if (!dir_emit(ctx, "..", 2, ino, DT_DIR)) | |
123 | return 0; | |
124 | } | |
125 | ||
126 | /* | |
127 | * Loop while there are more entries and put'ing works. | |
128 | */ | |
129 | sfep = xfs_dir2_sf_firstentry(sfp); | |
130 | for (i = 0; i < sfp->count; i++) { | |
131 | __uint8_t filetype; | |
132 | ||
133 | off = xfs_dir2_db_off_to_dataptr(geo, geo->datablk, | |
134 | xfs_dir2_sf_get_offset(sfep)); | |
135 | ||
136 | if (ctx->pos > off) { | |
137 | sfep = dp->d_ops->sf_nextentry(sfp, sfep); | |
138 | continue; | |
139 | } | |
140 | ||
141 | ino = dp->d_ops->sf_get_ino(sfp, sfep); | |
142 | filetype = dp->d_ops->sf_get_ftype(sfep); | |
143 | ctx->pos = off & 0x7fffffff; | |
144 | if (!dir_emit(ctx, (char *)sfep->name, sfep->namelen, ino, | |
145 | xfs_dir3_get_dtype(dp->i_mount, filetype))) | |
146 | return 0; | |
147 | sfep = dp->d_ops->sf_nextentry(sfp, sfep); | |
148 | } | |
149 | ||
150 | ctx->pos = xfs_dir2_db_off_to_dataptr(geo, geo->datablk + 1, 0) & | |
151 | 0x7fffffff; | |
152 | return 0; | |
153 | } | |
154 | ||
155 | /* | |
156 | * Readdir for block directories. | |
157 | */ | |
158 | STATIC int | |
159 | xfs_dir2_block_getdents( | |
160 | struct xfs_da_args *args, | |
161 | struct dir_context *ctx) | |
162 | { | |
163 | struct xfs_inode *dp = args->dp; /* incore directory inode */ | |
164 | xfs_dir2_data_hdr_t *hdr; /* block header */ | |
165 | struct xfs_buf *bp; /* buffer for block */ | |
166 | xfs_dir2_block_tail_t *btp; /* block tail */ | |
167 | xfs_dir2_data_entry_t *dep; /* block data entry */ | |
168 | xfs_dir2_data_unused_t *dup; /* block unused entry */ | |
169 | char *endptr; /* end of the data entries */ | |
170 | int error; /* error return value */ | |
171 | char *ptr; /* current data entry */ | |
172 | int wantoff; /* starting block offset */ | |
173 | xfs_off_t cook; | |
174 | struct xfs_da_geometry *geo = args->geo; | |
175 | int lock_mode; | |
176 | ||
177 | /* | |
178 | * If the block number in the offset is out of range, we're done. | |
179 | */ | |
180 | if (xfs_dir2_dataptr_to_db(geo, ctx->pos) > geo->datablk) | |
181 | return 0; | |
182 | ||
183 | lock_mode = xfs_ilock_data_map_shared(dp); | |
184 | error = xfs_dir3_block_read(NULL, dp, &bp); | |
185 | xfs_iunlock(dp, lock_mode); | |
186 | if (error) | |
187 | return error; | |
188 | ||
189 | /* | |
190 | * Extract the byte offset we start at from the seek pointer. | |
191 | * We'll skip entries before this. | |
192 | */ | |
193 | wantoff = xfs_dir2_dataptr_to_off(geo, ctx->pos); | |
194 | hdr = bp->b_addr; | |
195 | xfs_dir3_data_check(dp, bp); | |
196 | /* | |
197 | * Set up values for the loop. | |
198 | */ | |
199 | btp = xfs_dir2_block_tail_p(geo, hdr); | |
200 | ptr = (char *)dp->d_ops->data_entry_p(hdr); | |
201 | endptr = (char *)xfs_dir2_block_leaf_p(btp); | |
202 | ||
203 | /* | |
204 | * Loop over the data portion of the block. | |
205 | * Each object is a real entry (dep) or an unused one (dup). | |
206 | */ | |
207 | while (ptr < endptr) { | |
208 | __uint8_t filetype; | |
209 | ||
210 | dup = (xfs_dir2_data_unused_t *)ptr; | |
211 | /* | |
212 | * Unused, skip it. | |
213 | */ | |
214 | if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) { | |
215 | ptr += be16_to_cpu(dup->length); | |
216 | continue; | |
217 | } | |
218 | ||
219 | dep = (xfs_dir2_data_entry_t *)ptr; | |
220 | ||
221 | /* | |
222 | * Bump pointer for the next iteration. | |
223 | */ | |
224 | ptr += dp->d_ops->data_entsize(dep->namelen); | |
225 | /* | |
226 | * The entry is before the desired starting point, skip it. | |
227 | */ | |
228 | if ((char *)dep - (char *)hdr < wantoff) | |
229 | continue; | |
230 | ||
231 | cook = xfs_dir2_db_off_to_dataptr(geo, geo->datablk, | |
232 | (char *)dep - (char *)hdr); | |
233 | ||
234 | ctx->pos = cook & 0x7fffffff; | |
235 | filetype = dp->d_ops->data_get_ftype(dep); | |
236 | /* | |
237 | * If it didn't fit, set the final offset to here & return. | |
238 | */ | |
239 | if (!dir_emit(ctx, (char *)dep->name, dep->namelen, | |
240 | be64_to_cpu(dep->inumber), | |
241 | xfs_dir3_get_dtype(dp->i_mount, filetype))) { | |
242 | xfs_trans_brelse(NULL, bp); | |
243 | return 0; | |
244 | } | |
245 | } | |
246 | ||
247 | /* | |
248 | * Reached the end of the block. | |
249 | * Set the offset to a non-existent block 1 and return. | |
250 | */ | |
251 | ctx->pos = xfs_dir2_db_off_to_dataptr(geo, geo->datablk + 1, 0) & | |
252 | 0x7fffffff; | |
253 | xfs_trans_brelse(NULL, bp); | |
254 | return 0; | |
255 | } | |
256 | ||
257 | struct xfs_dir2_leaf_map_info { | |
258 | xfs_extlen_t map_blocks; /* number of fsbs in map */ | |
259 | xfs_dablk_t map_off; /* last mapped file offset */ | |
260 | int map_size; /* total entries in *map */ | |
261 | int map_valid; /* valid entries in *map */ | |
262 | int nmap; /* mappings to ask xfs_bmapi */ | |
263 | xfs_dir2_db_t curdb; /* db for current block */ | |
264 | int ra_current; /* number of read-ahead blks */ | |
265 | int ra_index; /* *map index for read-ahead */ | |
266 | int ra_offset; /* map entry offset for ra */ | |
267 | int ra_want; /* readahead count wanted */ | |
268 | struct xfs_bmbt_irec map[]; /* map vector for blocks */ | |
269 | }; | |
270 | ||
271 | STATIC int | |
272 | xfs_dir2_leaf_readbuf( | |
273 | struct xfs_da_args *args, | |
274 | size_t bufsize, | |
275 | struct xfs_dir2_leaf_map_info *mip, | |
276 | xfs_dir2_off_t *curoff, | |
277 | struct xfs_buf **bpp, | |
278 | bool trim_map) | |
279 | { | |
280 | struct xfs_inode *dp = args->dp; | |
281 | struct xfs_buf *bp = NULL; | |
282 | struct xfs_bmbt_irec *map = mip->map; | |
283 | struct blk_plug plug; | |
284 | int error = 0; | |
285 | int length; | |
286 | int i; | |
287 | int j; | |
288 | struct xfs_da_geometry *geo = args->geo; | |
289 | ||
290 | /* | |
291 | * If the caller just finished processing a buffer, it will tell us | |
292 | * we need to trim that block out of the mapping now it is done. | |
293 | */ | |
294 | if (trim_map) { | |
295 | mip->map_blocks -= geo->fsbcount; | |
296 | /* | |
297 | * Loop to get rid of the extents for the | |
298 | * directory block. | |
299 | */ | |
300 | for (i = geo->fsbcount; i > 0; ) { | |
301 | j = min_t(int, map->br_blockcount, i); | |
302 | map->br_blockcount -= j; | |
303 | map->br_startblock += j; | |
304 | map->br_startoff += j; | |
305 | /* | |
306 | * If mapping is done, pitch it from | |
307 | * the table. | |
308 | */ | |
309 | if (!map->br_blockcount && --mip->map_valid) | |
310 | memmove(&map[0], &map[1], | |
311 | sizeof(map[0]) * mip->map_valid); | |
312 | i -= j; | |
313 | } | |
314 | } | |
315 | ||
316 | /* | |
317 | * Recalculate the readahead blocks wanted. | |
318 | */ | |
319 | mip->ra_want = howmany(bufsize + geo->blksize, (1 << geo->fsblog)) - 1; | |
320 | ASSERT(mip->ra_want >= 0); | |
321 | ||
322 | /* | |
323 | * If we don't have as many as we want, and we haven't | |
324 | * run out of data blocks, get some more mappings. | |
325 | */ | |
326 | if (1 + mip->ra_want > mip->map_blocks && | |
327 | mip->map_off < xfs_dir2_byte_to_da(geo, XFS_DIR2_LEAF_OFFSET)) { | |
328 | /* | |
329 | * Get more bmaps, fill in after the ones | |
330 | * we already have in the table. | |
331 | */ | |
332 | mip->nmap = mip->map_size - mip->map_valid; | |
333 | error = xfs_bmapi_read(dp, mip->map_off, | |
334 | xfs_dir2_byte_to_da(geo, XFS_DIR2_LEAF_OFFSET) - | |
335 | mip->map_off, | |
336 | &map[mip->map_valid], &mip->nmap, 0); | |
337 | ||
338 | /* | |
339 | * Don't know if we should ignore this or try to return an | |
340 | * error. The trouble with returning errors is that readdir | |
341 | * will just stop without actually passing the error through. | |
342 | */ | |
343 | if (error) | |
344 | goto out; /* XXX */ | |
345 | ||
346 | /* | |
347 | * If we got all the mappings we asked for, set the final map | |
348 | * offset based on the last bmap value received. Otherwise, | |
349 | * we've reached the end. | |
350 | */ | |
351 | if (mip->nmap == mip->map_size - mip->map_valid) { | |
352 | i = mip->map_valid + mip->nmap - 1; | |
353 | mip->map_off = map[i].br_startoff + map[i].br_blockcount; | |
354 | } else | |
355 | mip->map_off = xfs_dir2_byte_to_da(geo, | |
356 | XFS_DIR2_LEAF_OFFSET); | |
357 | ||
358 | /* | |
359 | * Look for holes in the mapping, and eliminate them. Count up | |
360 | * the valid blocks. | |
361 | */ | |
362 | for (i = mip->map_valid; i < mip->map_valid + mip->nmap; ) { | |
363 | if (map[i].br_startblock == HOLESTARTBLOCK) { | |
364 | mip->nmap--; | |
365 | length = mip->map_valid + mip->nmap - i; | |
366 | if (length) | |
367 | memmove(&map[i], &map[i + 1], | |
368 | sizeof(map[i]) * length); | |
369 | } else { | |
370 | mip->map_blocks += map[i].br_blockcount; | |
371 | i++; | |
372 | } | |
373 | } | |
374 | mip->map_valid += mip->nmap; | |
375 | } | |
376 | ||
377 | /* | |
378 | * No valid mappings, so no more data blocks. | |
379 | */ | |
380 | if (!mip->map_valid) { | |
381 | *curoff = xfs_dir2_da_to_byte(geo, mip->map_off); | |
382 | goto out; | |
383 | } | |
384 | ||
385 | /* | |
386 | * Read the directory block starting at the first mapping. | |
387 | */ | |
388 | mip->curdb = xfs_dir2_da_to_db(geo, map->br_startoff); | |
389 | error = xfs_dir3_data_read(NULL, dp, map->br_startoff, | |
390 | map->br_blockcount >= geo->fsbcount ? | |
391 | XFS_FSB_TO_DADDR(dp->i_mount, map->br_startblock) : | |
392 | -1, &bp); | |
393 | /* | |
394 | * Should just skip over the data block instead of giving up. | |
395 | */ | |
396 | if (error) | |
397 | goto out; /* XXX */ | |
398 | ||
399 | /* | |
400 | * Adjust the current amount of read-ahead: we just read a block that | |
401 | * was previously ra. | |
402 | */ | |
403 | if (mip->ra_current) | |
404 | mip->ra_current -= geo->fsbcount; | |
405 | ||
406 | /* | |
407 | * Do we need more readahead? | |
408 | */ | |
409 | blk_start_plug(&plug); | |
410 | for (mip->ra_index = mip->ra_offset = i = 0; | |
411 | mip->ra_want > mip->ra_current && i < mip->map_blocks; | |
412 | i += geo->fsbcount) { | |
413 | ASSERT(mip->ra_index < mip->map_valid); | |
414 | /* | |
415 | * Read-ahead a contiguous directory block. | |
416 | */ | |
417 | if (i > mip->ra_current && | |
418 | map[mip->ra_index].br_blockcount >= geo->fsbcount) { | |
419 | xfs_dir3_data_readahead(dp, | |
420 | map[mip->ra_index].br_startoff + mip->ra_offset, | |
421 | XFS_FSB_TO_DADDR(dp->i_mount, | |
422 | map[mip->ra_index].br_startblock + | |
423 | mip->ra_offset)); | |
424 | mip->ra_current = i; | |
425 | } | |
426 | ||
427 | /* | |
428 | * Read-ahead a non-contiguous directory block. This doesn't | |
429 | * use our mapping, but this is a very rare case. | |
430 | */ | |
431 | else if (i > mip->ra_current) { | |
432 | xfs_dir3_data_readahead(dp, | |
433 | map[mip->ra_index].br_startoff + | |
434 | mip->ra_offset, -1); | |
435 | mip->ra_current = i; | |
436 | } | |
437 | ||
438 | /* | |
439 | * Advance offset through the mapping table. | |
440 | */ | |
441 | for (j = 0; j < geo->fsbcount; j += length ) { | |
442 | /* | |
443 | * The rest of this extent but not more than a dir | |
444 | * block. | |
445 | */ | |
446 | length = min_t(int, geo->fsbcount, | |
447 | map[mip->ra_index].br_blockcount - | |
448 | mip->ra_offset); | |
449 | mip->ra_offset += length; | |
450 | ||
451 | /* | |
452 | * Advance to the next mapping if this one is used up. | |
453 | */ | |
454 | if (mip->ra_offset == map[mip->ra_index].br_blockcount) { | |
455 | mip->ra_offset = 0; | |
456 | mip->ra_index++; | |
457 | } | |
458 | } | |
459 | } | |
460 | blk_finish_plug(&plug); | |
461 | ||
462 | out: | |
463 | *bpp = bp; | |
464 | return error; | |
465 | } | |
466 | ||
467 | /* | |
468 | * Getdents (readdir) for leaf and node directories. | |
469 | * This reads the data blocks only, so is the same for both forms. | |
470 | */ | |
471 | STATIC int | |
472 | xfs_dir2_leaf_getdents( | |
473 | struct xfs_da_args *args, | |
474 | struct dir_context *ctx, | |
475 | size_t bufsize) | |
476 | { | |
477 | struct xfs_inode *dp = args->dp; | |
478 | struct xfs_buf *bp = NULL; /* data block buffer */ | |
479 | xfs_dir2_data_hdr_t *hdr; /* data block header */ | |
480 | xfs_dir2_data_entry_t *dep; /* data entry */ | |
481 | xfs_dir2_data_unused_t *dup; /* unused entry */ | |
482 | int error = 0; /* error return value */ | |
483 | int length; /* temporary length value */ | |
484 | int byteoff; /* offset in current block */ | |
485 | xfs_dir2_off_t curoff; /* current overall offset */ | |
486 | xfs_dir2_off_t newoff; /* new curoff after new blk */ | |
487 | char *ptr = NULL; /* pointer to current data */ | |
488 | struct xfs_dir2_leaf_map_info *map_info; | |
489 | struct xfs_da_geometry *geo = args->geo; | |
490 | ||
491 | /* | |
492 | * If the offset is at or past the largest allowed value, | |
493 | * give up right away. | |
494 | */ | |
495 | if (ctx->pos >= XFS_DIR2_MAX_DATAPTR) | |
496 | return 0; | |
497 | ||
498 | /* | |
499 | * Set up to bmap a number of blocks based on the caller's | |
500 | * buffer size, the directory block size, and the filesystem | |
501 | * block size. | |
502 | */ | |
503 | length = howmany(bufsize + geo->blksize, (1 << geo->fsblog)); | |
504 | map_info = kmem_zalloc(offsetof(struct xfs_dir2_leaf_map_info, map) + | |
505 | (length * sizeof(struct xfs_bmbt_irec)), | |
506 | KM_SLEEP | KM_NOFS); | |
507 | map_info->map_size = length; | |
508 | ||
509 | /* | |
510 | * Inside the loop we keep the main offset value as a byte offset | |
511 | * in the directory file. | |
512 | */ | |
513 | curoff = xfs_dir2_dataptr_to_byte(ctx->pos); | |
514 | ||
515 | /* | |
516 | * Force this conversion through db so we truncate the offset | |
517 | * down to get the start of the data block. | |
518 | */ | |
519 | map_info->map_off = xfs_dir2_db_to_da(geo, | |
520 | xfs_dir2_byte_to_db(geo, curoff)); | |
521 | ||
522 | /* | |
523 | * Loop over directory entries until we reach the end offset. | |
524 | * Get more blocks and readahead as necessary. | |
525 | */ | |
526 | while (curoff < XFS_DIR2_LEAF_OFFSET) { | |
527 | __uint8_t filetype; | |
528 | ||
529 | /* | |
530 | * If we have no buffer, or we're off the end of the | |
531 | * current buffer, need to get another one. | |
532 | */ | |
533 | if (!bp || ptr >= (char *)bp->b_addr + geo->blksize) { | |
534 | int lock_mode; | |
535 | bool trim_map = false; | |
536 | ||
537 | if (bp) { | |
538 | xfs_trans_brelse(NULL, bp); | |
539 | bp = NULL; | |
540 | trim_map = true; | |
541 | } | |
542 | ||
543 | lock_mode = xfs_ilock_data_map_shared(dp); | |
544 | error = xfs_dir2_leaf_readbuf(args, bufsize, map_info, | |
545 | &curoff, &bp, trim_map); | |
546 | xfs_iunlock(dp, lock_mode); | |
547 | if (error || !map_info->map_valid) | |
548 | break; | |
549 | ||
550 | /* | |
551 | * Having done a read, we need to set a new offset. | |
552 | */ | |
553 | newoff = xfs_dir2_db_off_to_byte(geo, | |
554 | map_info->curdb, 0); | |
555 | /* | |
556 | * Start of the current block. | |
557 | */ | |
558 | if (curoff < newoff) | |
559 | curoff = newoff; | |
560 | /* | |
561 | * Make sure we're in the right block. | |
562 | */ | |
563 | else if (curoff > newoff) | |
564 | ASSERT(xfs_dir2_byte_to_db(geo, curoff) == | |
565 | map_info->curdb); | |
566 | hdr = bp->b_addr; | |
567 | xfs_dir3_data_check(dp, bp); | |
568 | /* | |
569 | * Find our position in the block. | |
570 | */ | |
571 | ptr = (char *)dp->d_ops->data_entry_p(hdr); | |
572 | byteoff = xfs_dir2_byte_to_off(geo, curoff); | |
573 | /* | |
574 | * Skip past the header. | |
575 | */ | |
576 | if (byteoff == 0) | |
577 | curoff += dp->d_ops->data_entry_offset; | |
578 | /* | |
579 | * Skip past entries until we reach our offset. | |
580 | */ | |
581 | else { | |
582 | while ((char *)ptr - (char *)hdr < byteoff) { | |
583 | dup = (xfs_dir2_data_unused_t *)ptr; | |
584 | ||
585 | if (be16_to_cpu(dup->freetag) | |
586 | == XFS_DIR2_DATA_FREE_TAG) { | |
587 | ||
588 | length = be16_to_cpu(dup->length); | |
589 | ptr += length; | |
590 | continue; | |
591 | } | |
592 | dep = (xfs_dir2_data_entry_t *)ptr; | |
593 | length = | |
594 | dp->d_ops->data_entsize(dep->namelen); | |
595 | ptr += length; | |
596 | } | |
597 | /* | |
598 | * Now set our real offset. | |
599 | */ | |
600 | curoff = | |
601 | xfs_dir2_db_off_to_byte(geo, | |
602 | xfs_dir2_byte_to_db(geo, curoff), | |
603 | (char *)ptr - (char *)hdr); | |
604 | if (ptr >= (char *)hdr + geo->blksize) { | |
605 | continue; | |
606 | } | |
607 | } | |
608 | } | |
609 | /* | |
610 | * We have a pointer to an entry. | |
611 | * Is it a live one? | |
612 | */ | |
613 | dup = (xfs_dir2_data_unused_t *)ptr; | |
614 | /* | |
615 | * No, it's unused, skip over it. | |
616 | */ | |
617 | if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) { | |
618 | length = be16_to_cpu(dup->length); | |
619 | ptr += length; | |
620 | curoff += length; | |
621 | continue; | |
622 | } | |
623 | ||
624 | dep = (xfs_dir2_data_entry_t *)ptr; | |
625 | length = dp->d_ops->data_entsize(dep->namelen); | |
626 | filetype = dp->d_ops->data_get_ftype(dep); | |
627 | ||
628 | ctx->pos = xfs_dir2_byte_to_dataptr(curoff) & 0x7fffffff; | |
629 | if (!dir_emit(ctx, (char *)dep->name, dep->namelen, | |
630 | be64_to_cpu(dep->inumber), | |
631 | xfs_dir3_get_dtype(dp->i_mount, filetype))) | |
632 | break; | |
633 | ||
634 | /* | |
635 | * Advance to next entry in the block. | |
636 | */ | |
637 | ptr += length; | |
638 | curoff += length; | |
639 | /* bufsize may have just been a guess; don't go negative */ | |
640 | bufsize = bufsize > length ? bufsize - length : 0; | |
641 | } | |
642 | ||
643 | /* | |
644 | * All done. Set output offset value to current offset. | |
645 | */ | |
646 | if (curoff > xfs_dir2_dataptr_to_byte(XFS_DIR2_MAX_DATAPTR)) | |
647 | ctx->pos = XFS_DIR2_MAX_DATAPTR & 0x7fffffff; | |
648 | else | |
649 | ctx->pos = xfs_dir2_byte_to_dataptr(curoff) & 0x7fffffff; | |
650 | kmem_free(map_info); | |
651 | if (bp) | |
652 | xfs_trans_brelse(NULL, bp); | |
653 | return error; | |
654 | } | |
655 | ||
656 | /* | |
657 | * Read a directory. | |
658 | */ | |
659 | int | |
660 | xfs_readdir( | |
661 | struct xfs_inode *dp, | |
662 | struct dir_context *ctx, | |
663 | size_t bufsize) | |
664 | { | |
665 | struct xfs_da_args args = { NULL }; | |
666 | int rval; | |
667 | int v; | |
668 | ||
669 | trace_xfs_readdir(dp); | |
670 | ||
671 | if (XFS_FORCED_SHUTDOWN(dp->i_mount)) | |
672 | return -EIO; | |
673 | ||
674 | ASSERT(S_ISDIR(VFS_I(dp)->i_mode)); | |
675 | XFS_STATS_INC(dp->i_mount, xs_dir_getdents); | |
676 | ||
677 | args.dp = dp; | |
678 | args.geo = dp->i_mount->m_dir_geo; | |
679 | ||
680 | if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) | |
681 | rval = xfs_dir2_sf_getdents(&args, ctx); | |
682 | else if ((rval = xfs_dir2_isblock(&args, &v))) | |
683 | ; | |
684 | else if (v) | |
685 | rval = xfs_dir2_block_getdents(&args, ctx); | |
686 | else | |
687 | rval = xfs_dir2_leaf_getdents(&args, ctx, bufsize); | |
688 | ||
689 | return rval; | |
690 | } |