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4a8af273 DC |
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" | |
a4fbe6ab | 21 | #include "xfs_format.h" |
239880ef DC |
22 | #include "xfs_log_format.h" |
23 | #include "xfs_trans_resv.h" | |
4a8af273 | 24 | #include "xfs_bit.h" |
4a8af273 DC |
25 | #include "xfs_sb.h" |
26 | #include "xfs_ag.h" | |
27 | #include "xfs_mount.h" | |
57062787 | 28 | #include "xfs_da_format.h" |
4a8af273 | 29 | #include "xfs_da_btree.h" |
4a8af273 | 30 | #include "xfs_inode.h" |
2b9ab5ab | 31 | #include "xfs_dir2.h" |
4a8af273 DC |
32 | #include "xfs_dir2_priv.h" |
33 | #include "xfs_error.h" | |
34 | #include "xfs_trace.h" | |
35 | #include "xfs_bmap.h" | |
239880ef | 36 | #include "xfs_trans.h" |
a4fbe6ab | 37 | #include "xfs_dinode.h" |
4a8af273 | 38 | |
0cb97766 DC |
39 | /* |
40 | * Directory file type support functions | |
41 | */ | |
42 | static unsigned char xfs_dir3_filetype_table[] = { | |
43 | DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, | |
44 | DT_FIFO, DT_SOCK, DT_LNK, DT_WHT, | |
45 | }; | |
46 | ||
47 | unsigned char | |
48 | xfs_dir3_get_dtype( | |
49 | struct xfs_mount *mp, | |
50 | __uint8_t filetype) | |
51 | { | |
52 | if (!xfs_sb_version_hasftype(&mp->m_sb)) | |
53 | return DT_UNKNOWN; | |
54 | ||
55 | if (filetype >= XFS_DIR3_FT_MAX) | |
56 | return DT_UNKNOWN; | |
57 | ||
58 | return xfs_dir3_filetype_table[filetype]; | |
59 | } | |
60 | /* | |
61 | * @mode, if set, indicates that the type field needs to be set up. | |
62 | * This uses the transformation from file mode to DT_* as defined in linux/fs.h | |
63 | * for file type specification. This will be propagated into the directory | |
64 | * structure if appropriate for the given operation and filesystem config. | |
65 | */ | |
66 | const unsigned char xfs_mode_to_ftype[S_IFMT >> S_SHIFT] = { | |
67 | [0] = XFS_DIR3_FT_UNKNOWN, | |
68 | [S_IFREG >> S_SHIFT] = XFS_DIR3_FT_REG_FILE, | |
69 | [S_IFDIR >> S_SHIFT] = XFS_DIR3_FT_DIR, | |
70 | [S_IFCHR >> S_SHIFT] = XFS_DIR3_FT_CHRDEV, | |
71 | [S_IFBLK >> S_SHIFT] = XFS_DIR3_FT_BLKDEV, | |
72 | [S_IFIFO >> S_SHIFT] = XFS_DIR3_FT_FIFO, | |
73 | [S_IFSOCK >> S_SHIFT] = XFS_DIR3_FT_SOCK, | |
74 | [S_IFLNK >> S_SHIFT] = XFS_DIR3_FT_SYMLINK, | |
75 | }; | |
76 | ||
4a8af273 DC |
77 | STATIC int |
78 | xfs_dir2_sf_getdents( | |
79 | xfs_inode_t *dp, /* incore directory inode */ | |
80 | struct dir_context *ctx) | |
81 | { | |
82 | int i; /* shortform entry number */ | |
83 | xfs_mount_t *mp; /* filesystem mount point */ | |
84 | xfs_dir2_dataptr_t off; /* current entry's offset */ | |
85 | xfs_dir2_sf_entry_t *sfep; /* shortform directory entry */ | |
86 | xfs_dir2_sf_hdr_t *sfp; /* shortform structure */ | |
87 | xfs_dir2_dataptr_t dot_offset; | |
88 | xfs_dir2_dataptr_t dotdot_offset; | |
89 | xfs_ino_t ino; | |
90 | ||
91 | mp = dp->i_mount; | |
92 | ||
93 | ASSERT(dp->i_df.if_flags & XFS_IFINLINE); | |
94 | /* | |
95 | * Give up if the directory is way too short. | |
96 | */ | |
97 | if (dp->i_d.di_size < offsetof(xfs_dir2_sf_hdr_t, parent)) { | |
98 | ASSERT(XFS_FORCED_SHUTDOWN(mp)); | |
99 | return XFS_ERROR(EIO); | |
100 | } | |
101 | ||
102 | ASSERT(dp->i_df.if_bytes == dp->i_d.di_size); | |
103 | ASSERT(dp->i_df.if_u1.if_data != NULL); | |
104 | ||
105 | sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data; | |
106 | ||
107 | ASSERT(dp->i_d.di_size >= xfs_dir2_sf_hdr_size(sfp->i8count)); | |
108 | ||
109 | /* | |
110 | * If the block number in the offset is out of range, we're done. | |
111 | */ | |
112 | if (xfs_dir2_dataptr_to_db(mp, ctx->pos) > mp->m_dirdatablk) | |
113 | return 0; | |
114 | ||
115 | /* | |
116 | * Precalculate offsets for . and .. as we will always need them. | |
117 | * | |
118 | * XXX(hch): the second argument is sometimes 0 and sometimes | |
119 | * mp->m_dirdatablk. | |
120 | */ | |
121 | dot_offset = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk, | |
1c9a5b2e | 122 | dp->d_ops->data_dot_offset); |
4a8af273 | 123 | dotdot_offset = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk, |
1c9a5b2e | 124 | dp->d_ops->data_dotdot_offset); |
4a8af273 DC |
125 | |
126 | /* | |
127 | * Put . entry unless we're starting past it. | |
128 | */ | |
129 | if (ctx->pos <= dot_offset) { | |
130 | ctx->pos = dot_offset & 0x7fffffff; | |
131 | if (!dir_emit(ctx, ".", 1, dp->i_ino, DT_DIR)) | |
132 | return 0; | |
133 | } | |
134 | ||
135 | /* | |
136 | * Put .. entry unless we're starting past it. | |
137 | */ | |
138 | if (ctx->pos <= dotdot_offset) { | |
4740175e | 139 | ino = dp->d_ops->sf_get_parent_ino(sfp); |
4a8af273 DC |
140 | ctx->pos = dotdot_offset & 0x7fffffff; |
141 | if (!dir_emit(ctx, "..", 2, ino, DT_DIR)) | |
142 | return 0; | |
143 | } | |
144 | ||
145 | /* | |
146 | * Loop while there are more entries and put'ing works. | |
147 | */ | |
148 | sfep = xfs_dir2_sf_firstentry(sfp); | |
149 | for (i = 0; i < sfp->count; i++) { | |
0cb97766 DC |
150 | __uint8_t filetype; |
151 | ||
4a8af273 DC |
152 | off = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk, |
153 | xfs_dir2_sf_get_offset(sfep)); | |
154 | ||
155 | if (ctx->pos > off) { | |
32c5483a | 156 | sfep = dp->d_ops->sf_nextentry(sfp, sfep); |
4a8af273 DC |
157 | continue; |
158 | } | |
159 | ||
4740175e DC |
160 | ino = dp->d_ops->sf_get_ino(sfp, sfep); |
161 | filetype = dp->d_ops->sf_get_ftype(sfep); | |
4a8af273 | 162 | ctx->pos = off & 0x7fffffff; |
0cb97766 DC |
163 | if (!dir_emit(ctx, (char *)sfep->name, sfep->namelen, ino, |
164 | xfs_dir3_get_dtype(mp, filetype))) | |
4a8af273 | 165 | return 0; |
32c5483a | 166 | sfep = dp->d_ops->sf_nextentry(sfp, sfep); |
4a8af273 DC |
167 | } |
168 | ||
169 | ctx->pos = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk + 1, 0) & | |
170 | 0x7fffffff; | |
171 | return 0; | |
172 | } | |
173 | ||
174 | /* | |
175 | * Readdir for block directories. | |
176 | */ | |
177 | STATIC int | |
178 | xfs_dir2_block_getdents( | |
179 | xfs_inode_t *dp, /* incore inode */ | |
180 | struct dir_context *ctx) | |
181 | { | |
182 | xfs_dir2_data_hdr_t *hdr; /* block header */ | |
183 | struct xfs_buf *bp; /* buffer for block */ | |
184 | xfs_dir2_block_tail_t *btp; /* block tail */ | |
185 | xfs_dir2_data_entry_t *dep; /* block data entry */ | |
186 | xfs_dir2_data_unused_t *dup; /* block unused entry */ | |
187 | char *endptr; /* end of the data entries */ | |
188 | int error; /* error return value */ | |
189 | xfs_mount_t *mp; /* filesystem mount point */ | |
190 | char *ptr; /* current data entry */ | |
191 | int wantoff; /* starting block offset */ | |
192 | xfs_off_t cook; | |
193 | ||
194 | mp = dp->i_mount; | |
195 | /* | |
196 | * If the block number in the offset is out of range, we're done. | |
197 | */ | |
198 | if (xfs_dir2_dataptr_to_db(mp, ctx->pos) > mp->m_dirdatablk) | |
199 | return 0; | |
200 | ||
201 | error = xfs_dir3_block_read(NULL, dp, &bp); | |
202 | if (error) | |
203 | return error; | |
204 | ||
205 | /* | |
206 | * Extract the byte offset we start at from the seek pointer. | |
207 | * We'll skip entries before this. | |
208 | */ | |
209 | wantoff = xfs_dir2_dataptr_to_off(mp, ctx->pos); | |
210 | hdr = bp->b_addr; | |
211 | xfs_dir3_data_check(dp, bp); | |
212 | /* | |
213 | * Set up values for the loop. | |
214 | */ | |
215 | btp = xfs_dir2_block_tail_p(mp, hdr); | |
2ca98774 | 216 | ptr = (char *)dp->d_ops->data_entry_p(hdr); |
4a8af273 DC |
217 | endptr = (char *)xfs_dir2_block_leaf_p(btp); |
218 | ||
219 | /* | |
220 | * Loop over the data portion of the block. | |
221 | * Each object is a real entry (dep) or an unused one (dup). | |
222 | */ | |
223 | while (ptr < endptr) { | |
0cb97766 DC |
224 | __uint8_t filetype; |
225 | ||
4a8af273 DC |
226 | dup = (xfs_dir2_data_unused_t *)ptr; |
227 | /* | |
228 | * Unused, skip it. | |
229 | */ | |
230 | if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) { | |
231 | ptr += be16_to_cpu(dup->length); | |
232 | continue; | |
233 | } | |
234 | ||
235 | dep = (xfs_dir2_data_entry_t *)ptr; | |
236 | ||
237 | /* | |
238 | * Bump pointer for the next iteration. | |
239 | */ | |
9d23fc85 | 240 | ptr += dp->d_ops->data_entsize(dep->namelen); |
4a8af273 DC |
241 | /* |
242 | * The entry is before the desired starting point, skip it. | |
243 | */ | |
244 | if ((char *)dep - (char *)hdr < wantoff) | |
245 | continue; | |
246 | ||
247 | cook = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk, | |
248 | (char *)dep - (char *)hdr); | |
249 | ||
250 | ctx->pos = cook & 0x7fffffff; | |
9d23fc85 | 251 | filetype = dp->d_ops->data_get_ftype(dep); |
4a8af273 DC |
252 | /* |
253 | * If it didn't fit, set the final offset to here & return. | |
254 | */ | |
255 | if (!dir_emit(ctx, (char *)dep->name, dep->namelen, | |
0cb97766 DC |
256 | be64_to_cpu(dep->inumber), |
257 | xfs_dir3_get_dtype(mp, filetype))) { | |
4a8af273 DC |
258 | xfs_trans_brelse(NULL, bp); |
259 | return 0; | |
260 | } | |
261 | } | |
262 | ||
263 | /* | |
264 | * Reached the end of the block. | |
265 | * Set the offset to a non-existent block 1 and return. | |
266 | */ | |
267 | ctx->pos = xfs_dir2_db_off_to_dataptr(mp, mp->m_dirdatablk + 1, 0) & | |
268 | 0x7fffffff; | |
269 | xfs_trans_brelse(NULL, bp); | |
270 | return 0; | |
271 | } | |
272 | ||
273 | struct xfs_dir2_leaf_map_info { | |
274 | xfs_extlen_t map_blocks; /* number of fsbs in map */ | |
275 | xfs_dablk_t map_off; /* last mapped file offset */ | |
276 | int map_size; /* total entries in *map */ | |
277 | int map_valid; /* valid entries in *map */ | |
278 | int nmap; /* mappings to ask xfs_bmapi */ | |
279 | xfs_dir2_db_t curdb; /* db for current block */ | |
280 | int ra_current; /* number of read-ahead blks */ | |
281 | int ra_index; /* *map index for read-ahead */ | |
282 | int ra_offset; /* map entry offset for ra */ | |
283 | int ra_want; /* readahead count wanted */ | |
284 | struct xfs_bmbt_irec map[]; /* map vector for blocks */ | |
285 | }; | |
286 | ||
287 | STATIC int | |
288 | xfs_dir2_leaf_readbuf( | |
289 | struct xfs_inode *dp, | |
290 | size_t bufsize, | |
291 | struct xfs_dir2_leaf_map_info *mip, | |
292 | xfs_dir2_off_t *curoff, | |
293 | struct xfs_buf **bpp) | |
294 | { | |
295 | struct xfs_mount *mp = dp->i_mount; | |
296 | struct xfs_buf *bp = *bpp; | |
297 | struct xfs_bmbt_irec *map = mip->map; | |
298 | struct blk_plug plug; | |
299 | int error = 0; | |
300 | int length; | |
301 | int i; | |
302 | int j; | |
303 | ||
304 | /* | |
305 | * If we have a buffer, we need to release it and | |
306 | * take it out of the mapping. | |
307 | */ | |
308 | ||
309 | if (bp) { | |
310 | xfs_trans_brelse(NULL, bp); | |
311 | bp = NULL; | |
312 | mip->map_blocks -= mp->m_dirblkfsbs; | |
313 | /* | |
314 | * Loop to get rid of the extents for the | |
315 | * directory block. | |
316 | */ | |
317 | for (i = mp->m_dirblkfsbs; i > 0; ) { | |
318 | j = min_t(int, map->br_blockcount, i); | |
319 | map->br_blockcount -= j; | |
320 | map->br_startblock += j; | |
321 | map->br_startoff += j; | |
322 | /* | |
323 | * If mapping is done, pitch it from | |
324 | * the table. | |
325 | */ | |
326 | if (!map->br_blockcount && --mip->map_valid) | |
327 | memmove(&map[0], &map[1], | |
328 | sizeof(map[0]) * mip->map_valid); | |
329 | i -= j; | |
330 | } | |
331 | } | |
332 | ||
333 | /* | |
334 | * Recalculate the readahead blocks wanted. | |
335 | */ | |
336 | mip->ra_want = howmany(bufsize + mp->m_dirblksize, | |
337 | mp->m_sb.sb_blocksize) - 1; | |
338 | ASSERT(mip->ra_want >= 0); | |
339 | ||
340 | /* | |
341 | * If we don't have as many as we want, and we haven't | |
342 | * run out of data blocks, get some more mappings. | |
343 | */ | |
344 | if (1 + mip->ra_want > mip->map_blocks && | |
345 | mip->map_off < xfs_dir2_byte_to_da(mp, XFS_DIR2_LEAF_OFFSET)) { | |
346 | /* | |
347 | * Get more bmaps, fill in after the ones | |
348 | * we already have in the table. | |
349 | */ | |
350 | mip->nmap = mip->map_size - mip->map_valid; | |
351 | error = xfs_bmapi_read(dp, mip->map_off, | |
352 | xfs_dir2_byte_to_da(mp, XFS_DIR2_LEAF_OFFSET) - | |
353 | mip->map_off, | |
354 | &map[mip->map_valid], &mip->nmap, 0); | |
355 | ||
356 | /* | |
357 | * Don't know if we should ignore this or try to return an | |
358 | * error. The trouble with returning errors is that readdir | |
359 | * will just stop without actually passing the error through. | |
360 | */ | |
361 | if (error) | |
362 | goto out; /* XXX */ | |
363 | ||
364 | /* | |
365 | * If we got all the mappings we asked for, set the final map | |
366 | * offset based on the last bmap value received. Otherwise, | |
367 | * we've reached the end. | |
368 | */ | |
369 | if (mip->nmap == mip->map_size - mip->map_valid) { | |
370 | i = mip->map_valid + mip->nmap - 1; | |
371 | mip->map_off = map[i].br_startoff + map[i].br_blockcount; | |
372 | } else | |
373 | mip->map_off = xfs_dir2_byte_to_da(mp, | |
374 | XFS_DIR2_LEAF_OFFSET); | |
375 | ||
376 | /* | |
377 | * Look for holes in the mapping, and eliminate them. Count up | |
378 | * the valid blocks. | |
379 | */ | |
380 | for (i = mip->map_valid; i < mip->map_valid + mip->nmap; ) { | |
381 | if (map[i].br_startblock == HOLESTARTBLOCK) { | |
382 | mip->nmap--; | |
383 | length = mip->map_valid + mip->nmap - i; | |
384 | if (length) | |
385 | memmove(&map[i], &map[i + 1], | |
386 | sizeof(map[i]) * length); | |
387 | } else { | |
388 | mip->map_blocks += map[i].br_blockcount; | |
389 | i++; | |
390 | } | |
391 | } | |
392 | mip->map_valid += mip->nmap; | |
393 | } | |
394 | ||
395 | /* | |
396 | * No valid mappings, so no more data blocks. | |
397 | */ | |
398 | if (!mip->map_valid) { | |
399 | *curoff = xfs_dir2_da_to_byte(mp, mip->map_off); | |
400 | goto out; | |
401 | } | |
402 | ||
403 | /* | |
404 | * Read the directory block starting at the first mapping. | |
405 | */ | |
406 | mip->curdb = xfs_dir2_da_to_db(mp, map->br_startoff); | |
407 | error = xfs_dir3_data_read(NULL, dp, map->br_startoff, | |
408 | map->br_blockcount >= mp->m_dirblkfsbs ? | |
409 | XFS_FSB_TO_DADDR(mp, map->br_startblock) : -1, &bp); | |
410 | ||
411 | /* | |
412 | * Should just skip over the data block instead of giving up. | |
413 | */ | |
414 | if (error) | |
415 | goto out; /* XXX */ | |
416 | ||
417 | /* | |
418 | * Adjust the current amount of read-ahead: we just read a block that | |
419 | * was previously ra. | |
420 | */ | |
421 | if (mip->ra_current) | |
422 | mip->ra_current -= mp->m_dirblkfsbs; | |
423 | ||
424 | /* | |
425 | * Do we need more readahead? | |
426 | */ | |
427 | blk_start_plug(&plug); | |
428 | for (mip->ra_index = mip->ra_offset = i = 0; | |
429 | mip->ra_want > mip->ra_current && i < mip->map_blocks; | |
430 | i += mp->m_dirblkfsbs) { | |
431 | ASSERT(mip->ra_index < mip->map_valid); | |
432 | /* | |
433 | * Read-ahead a contiguous directory block. | |
434 | */ | |
435 | if (i > mip->ra_current && | |
436 | map[mip->ra_index].br_blockcount >= mp->m_dirblkfsbs) { | |
437 | xfs_dir3_data_readahead(NULL, dp, | |
438 | map[mip->ra_index].br_startoff + mip->ra_offset, | |
439 | XFS_FSB_TO_DADDR(mp, | |
440 | map[mip->ra_index].br_startblock + | |
441 | mip->ra_offset)); | |
442 | mip->ra_current = i; | |
443 | } | |
444 | ||
445 | /* | |
446 | * Read-ahead a non-contiguous directory block. This doesn't | |
447 | * use our mapping, but this is a very rare case. | |
448 | */ | |
449 | else if (i > mip->ra_current) { | |
450 | xfs_dir3_data_readahead(NULL, dp, | |
451 | map[mip->ra_index].br_startoff + | |
452 | mip->ra_offset, -1); | |
453 | mip->ra_current = i; | |
454 | } | |
455 | ||
456 | /* | |
457 | * Advance offset through the mapping table. | |
458 | */ | |
459 | for (j = 0; j < mp->m_dirblkfsbs; j++) { | |
460 | /* | |
461 | * The rest of this extent but not more than a dir | |
462 | * block. | |
463 | */ | |
464 | length = min_t(int, mp->m_dirblkfsbs, | |
465 | map[mip->ra_index].br_blockcount - | |
466 | mip->ra_offset); | |
467 | j += length; | |
468 | mip->ra_offset += length; | |
469 | ||
470 | /* | |
471 | * Advance to the next mapping if this one is used up. | |
472 | */ | |
473 | if (mip->ra_offset == map[mip->ra_index].br_blockcount) { | |
474 | mip->ra_offset = 0; | |
475 | mip->ra_index++; | |
476 | } | |
477 | } | |
478 | } | |
479 | blk_finish_plug(&plug); | |
480 | ||
481 | out: | |
482 | *bpp = bp; | |
483 | return error; | |
484 | } | |
485 | ||
486 | /* | |
487 | * Getdents (readdir) for leaf and node directories. | |
488 | * This reads the data blocks only, so is the same for both forms. | |
489 | */ | |
490 | STATIC int | |
491 | xfs_dir2_leaf_getdents( | |
492 | xfs_inode_t *dp, /* incore directory inode */ | |
493 | struct dir_context *ctx, | |
494 | size_t bufsize) | |
495 | { | |
496 | struct xfs_buf *bp = NULL; /* data block buffer */ | |
497 | xfs_dir2_data_hdr_t *hdr; /* data block header */ | |
498 | xfs_dir2_data_entry_t *dep; /* data entry */ | |
499 | xfs_dir2_data_unused_t *dup; /* unused entry */ | |
500 | int error = 0; /* error return value */ | |
501 | int length; /* temporary length value */ | |
502 | xfs_mount_t *mp; /* filesystem mount point */ | |
503 | int byteoff; /* offset in current block */ | |
504 | xfs_dir2_off_t curoff; /* current overall offset */ | |
505 | xfs_dir2_off_t newoff; /* new curoff after new blk */ | |
506 | char *ptr = NULL; /* pointer to current data */ | |
507 | struct xfs_dir2_leaf_map_info *map_info; | |
508 | ||
509 | /* | |
510 | * If the offset is at or past the largest allowed value, | |
511 | * give up right away. | |
512 | */ | |
513 | if (ctx->pos >= XFS_DIR2_MAX_DATAPTR) | |
514 | return 0; | |
515 | ||
516 | mp = dp->i_mount; | |
517 | ||
518 | /* | |
519 | * Set up to bmap a number of blocks based on the caller's | |
520 | * buffer size, the directory block size, and the filesystem | |
521 | * block size. | |
522 | */ | |
523 | length = howmany(bufsize + mp->m_dirblksize, | |
524 | mp->m_sb.sb_blocksize); | |
525 | map_info = kmem_zalloc(offsetof(struct xfs_dir2_leaf_map_info, map) + | |
526 | (length * sizeof(struct xfs_bmbt_irec)), | |
527 | KM_SLEEP | KM_NOFS); | |
528 | map_info->map_size = length; | |
529 | ||
530 | /* | |
531 | * Inside the loop we keep the main offset value as a byte offset | |
532 | * in the directory file. | |
533 | */ | |
534 | curoff = xfs_dir2_dataptr_to_byte(mp, ctx->pos); | |
535 | ||
536 | /* | |
537 | * Force this conversion through db so we truncate the offset | |
538 | * down to get the start of the data block. | |
539 | */ | |
540 | map_info->map_off = xfs_dir2_db_to_da(mp, | |
541 | xfs_dir2_byte_to_db(mp, curoff)); | |
542 | ||
543 | /* | |
544 | * Loop over directory entries until we reach the end offset. | |
545 | * Get more blocks and readahead as necessary. | |
546 | */ | |
547 | while (curoff < XFS_DIR2_LEAF_OFFSET) { | |
0cb97766 DC |
548 | __uint8_t filetype; |
549 | ||
4a8af273 DC |
550 | /* |
551 | * If we have no buffer, or we're off the end of the | |
552 | * current buffer, need to get another one. | |
553 | */ | |
554 | if (!bp || ptr >= (char *)bp->b_addr + mp->m_dirblksize) { | |
555 | ||
556 | error = xfs_dir2_leaf_readbuf(dp, bufsize, map_info, | |
557 | &curoff, &bp); | |
558 | if (error || !map_info->map_valid) | |
559 | break; | |
560 | ||
561 | /* | |
562 | * Having done a read, we need to set a new offset. | |
563 | */ | |
564 | newoff = xfs_dir2_db_off_to_byte(mp, map_info->curdb, 0); | |
565 | /* | |
566 | * Start of the current block. | |
567 | */ | |
568 | if (curoff < newoff) | |
569 | curoff = newoff; | |
570 | /* | |
571 | * Make sure we're in the right block. | |
572 | */ | |
573 | else if (curoff > newoff) | |
574 | ASSERT(xfs_dir2_byte_to_db(mp, curoff) == | |
575 | map_info->curdb); | |
576 | hdr = bp->b_addr; | |
577 | xfs_dir3_data_check(dp, bp); | |
578 | /* | |
579 | * Find our position in the block. | |
580 | */ | |
2ca98774 | 581 | ptr = (char *)dp->d_ops->data_entry_p(hdr); |
4a8af273 DC |
582 | byteoff = xfs_dir2_byte_to_off(mp, curoff); |
583 | /* | |
584 | * Skip past the header. | |
585 | */ | |
586 | if (byteoff == 0) | |
1c9a5b2e | 587 | curoff += dp->d_ops->data_entry_offset; |
4a8af273 DC |
588 | /* |
589 | * Skip past entries until we reach our offset. | |
590 | */ | |
591 | else { | |
592 | while ((char *)ptr - (char *)hdr < byteoff) { | |
593 | dup = (xfs_dir2_data_unused_t *)ptr; | |
594 | ||
595 | if (be16_to_cpu(dup->freetag) | |
596 | == XFS_DIR2_DATA_FREE_TAG) { | |
597 | ||
598 | length = be16_to_cpu(dup->length); | |
599 | ptr += length; | |
600 | continue; | |
601 | } | |
602 | dep = (xfs_dir2_data_entry_t *)ptr; | |
603 | length = | |
9d23fc85 | 604 | dp->d_ops->data_entsize(dep->namelen); |
4a8af273 DC |
605 | ptr += length; |
606 | } | |
607 | /* | |
608 | * Now set our real offset. | |
609 | */ | |
610 | curoff = | |
611 | xfs_dir2_db_off_to_byte(mp, | |
612 | xfs_dir2_byte_to_db(mp, curoff), | |
613 | (char *)ptr - (char *)hdr); | |
614 | if (ptr >= (char *)hdr + mp->m_dirblksize) { | |
615 | continue; | |
616 | } | |
617 | } | |
618 | } | |
619 | /* | |
620 | * We have a pointer to an entry. | |
621 | * Is it a live one? | |
622 | */ | |
623 | dup = (xfs_dir2_data_unused_t *)ptr; | |
624 | /* | |
625 | * No, it's unused, skip over it. | |
626 | */ | |
627 | if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) { | |
628 | length = be16_to_cpu(dup->length); | |
629 | ptr += length; | |
630 | curoff += length; | |
631 | continue; | |
632 | } | |
633 | ||
634 | dep = (xfs_dir2_data_entry_t *)ptr; | |
9d23fc85 DC |
635 | length = dp->d_ops->data_entsize(dep->namelen); |
636 | filetype = dp->d_ops->data_get_ftype(dep); | |
4a8af273 DC |
637 | |
638 | ctx->pos = xfs_dir2_byte_to_dataptr(mp, curoff) & 0x7fffffff; | |
639 | if (!dir_emit(ctx, (char *)dep->name, dep->namelen, | |
0cb97766 DC |
640 | be64_to_cpu(dep->inumber), |
641 | xfs_dir3_get_dtype(mp, filetype))) | |
4a8af273 DC |
642 | break; |
643 | ||
644 | /* | |
645 | * Advance to next entry in the block. | |
646 | */ | |
647 | ptr += length; | |
648 | curoff += length; | |
649 | /* bufsize may have just been a guess; don't go negative */ | |
650 | bufsize = bufsize > length ? bufsize - length : 0; | |
651 | } | |
652 | ||
653 | /* | |
654 | * All done. Set output offset value to current offset. | |
655 | */ | |
656 | if (curoff > xfs_dir2_dataptr_to_byte(mp, XFS_DIR2_MAX_DATAPTR)) | |
657 | ctx->pos = XFS_DIR2_MAX_DATAPTR & 0x7fffffff; | |
658 | else | |
659 | ctx->pos = xfs_dir2_byte_to_dataptr(mp, curoff) & 0x7fffffff; | |
660 | kmem_free(map_info); | |
661 | if (bp) | |
662 | xfs_trans_brelse(NULL, bp); | |
663 | return error; | |
664 | } | |
665 | ||
666 | /* | |
667 | * Read a directory. | |
668 | */ | |
669 | int | |
670 | xfs_readdir( | |
671 | xfs_inode_t *dp, | |
672 | struct dir_context *ctx, | |
673 | size_t bufsize) | |
674 | { | |
675 | int rval; /* return value */ | |
676 | int v; /* type-checking value */ | |
40194ecc | 677 | uint lock_mode; |
4a8af273 DC |
678 | |
679 | trace_xfs_readdir(dp); | |
680 | ||
681 | if (XFS_FORCED_SHUTDOWN(dp->i_mount)) | |
682 | return XFS_ERROR(EIO); | |
683 | ||
684 | ASSERT(S_ISDIR(dp->i_d.di_mode)); | |
685 | XFS_STATS_INC(xs_dir_getdents); | |
686 | ||
40194ecc | 687 | lock_mode = xfs_ilock_data_map_shared(dp); |
4a8af273 DC |
688 | if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) |
689 | rval = xfs_dir2_sf_getdents(dp, ctx); | |
690 | else if ((rval = xfs_dir2_isblock(NULL, dp, &v))) | |
691 | ; | |
692 | else if (v) | |
693 | rval = xfs_dir2_block_getdents(dp, ctx); | |
694 | else | |
695 | rval = xfs_dir2_leaf_getdents(dp, ctx, bufsize); | |
40194ecc BM |
696 | xfs_iunlock(dp, lock_mode); |
697 | ||
4a8af273 DC |
698 | return rval; |
699 | } |