Commit | Line | Data |
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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; | |
30028030 | 90 | struct xfs_da_geometry *geo; |
4a8af273 DC |
91 | |
92 | mp = dp->i_mount; | |
30028030 | 93 | geo = mp->m_dir_geo; |
4a8af273 DC |
94 | |
95 | ASSERT(dp->i_df.if_flags & XFS_IFINLINE); | |
96 | /* | |
97 | * Give up if the directory is way too short. | |
98 | */ | |
99 | if (dp->i_d.di_size < offsetof(xfs_dir2_sf_hdr_t, parent)) { | |
100 | ASSERT(XFS_FORCED_SHUTDOWN(mp)); | |
101 | return XFS_ERROR(EIO); | |
102 | } | |
103 | ||
104 | ASSERT(dp->i_df.if_bytes == dp->i_d.di_size); | |
105 | ASSERT(dp->i_df.if_u1.if_data != NULL); | |
106 | ||
107 | sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data; | |
108 | ||
109 | ASSERT(dp->i_d.di_size >= xfs_dir2_sf_hdr_size(sfp->i8count)); | |
110 | ||
111 | /* | |
112 | * If the block number in the offset is out of range, we're done. | |
113 | */ | |
7dda6e86 | 114 | if (xfs_dir2_dataptr_to_db(geo, ctx->pos) > geo->datablk) |
4a8af273 DC |
115 | return 0; |
116 | ||
117 | /* | |
118 | * Precalculate offsets for . and .. as we will always need them. | |
119 | * | |
120 | * XXX(hch): the second argument is sometimes 0 and sometimes | |
7dda6e86 | 121 | * geo->datablk |
4a8af273 | 122 | */ |
7dda6e86 | 123 | dot_offset = xfs_dir2_db_off_to_dataptr(geo, geo->datablk, |
1c9a5b2e | 124 | dp->d_ops->data_dot_offset); |
7dda6e86 | 125 | dotdot_offset = xfs_dir2_db_off_to_dataptr(geo, geo->datablk, |
1c9a5b2e | 126 | dp->d_ops->data_dotdot_offset); |
4a8af273 DC |
127 | |
128 | /* | |
129 | * Put . entry unless we're starting past it. | |
130 | */ | |
131 | if (ctx->pos <= dot_offset) { | |
132 | ctx->pos = dot_offset & 0x7fffffff; | |
133 | if (!dir_emit(ctx, ".", 1, dp->i_ino, DT_DIR)) | |
134 | return 0; | |
135 | } | |
136 | ||
137 | /* | |
138 | * Put .. entry unless we're starting past it. | |
139 | */ | |
140 | if (ctx->pos <= dotdot_offset) { | |
4740175e | 141 | ino = dp->d_ops->sf_get_parent_ino(sfp); |
4a8af273 DC |
142 | ctx->pos = dotdot_offset & 0x7fffffff; |
143 | if (!dir_emit(ctx, "..", 2, ino, DT_DIR)) | |
144 | return 0; | |
145 | } | |
146 | ||
147 | /* | |
148 | * Loop while there are more entries and put'ing works. | |
149 | */ | |
150 | sfep = xfs_dir2_sf_firstentry(sfp); | |
151 | for (i = 0; i < sfp->count; i++) { | |
0cb97766 DC |
152 | __uint8_t filetype; |
153 | ||
7dda6e86 | 154 | off = xfs_dir2_db_off_to_dataptr(geo, geo->datablk, |
4a8af273 DC |
155 | xfs_dir2_sf_get_offset(sfep)); |
156 | ||
157 | if (ctx->pos > off) { | |
32c5483a | 158 | sfep = dp->d_ops->sf_nextentry(sfp, sfep); |
4a8af273 DC |
159 | continue; |
160 | } | |
161 | ||
4740175e DC |
162 | ino = dp->d_ops->sf_get_ino(sfp, sfep); |
163 | filetype = dp->d_ops->sf_get_ftype(sfep); | |
4a8af273 | 164 | ctx->pos = off & 0x7fffffff; |
0cb97766 DC |
165 | if (!dir_emit(ctx, (char *)sfep->name, sfep->namelen, ino, |
166 | xfs_dir3_get_dtype(mp, filetype))) | |
4a8af273 | 167 | return 0; |
32c5483a | 168 | sfep = dp->d_ops->sf_nextentry(sfp, sfep); |
4a8af273 DC |
169 | } |
170 | ||
7dda6e86 | 171 | ctx->pos = xfs_dir2_db_off_to_dataptr(geo, geo->datablk + 1, 0) & |
4a8af273 DC |
172 | 0x7fffffff; |
173 | return 0; | |
174 | } | |
175 | ||
176 | /* | |
177 | * Readdir for block directories. | |
178 | */ | |
179 | STATIC int | |
180 | xfs_dir2_block_getdents( | |
181 | xfs_inode_t *dp, /* incore inode */ | |
182 | struct dir_context *ctx) | |
183 | { | |
184 | xfs_dir2_data_hdr_t *hdr; /* block header */ | |
185 | struct xfs_buf *bp; /* buffer for block */ | |
186 | xfs_dir2_block_tail_t *btp; /* block tail */ | |
187 | xfs_dir2_data_entry_t *dep; /* block data entry */ | |
188 | xfs_dir2_data_unused_t *dup; /* block unused entry */ | |
189 | char *endptr; /* end of the data entries */ | |
190 | int error; /* error return value */ | |
191 | xfs_mount_t *mp; /* filesystem mount point */ | |
192 | char *ptr; /* current data entry */ | |
193 | int wantoff; /* starting block offset */ | |
194 | xfs_off_t cook; | |
30028030 | 195 | struct xfs_da_geometry *geo; |
4a8af273 DC |
196 | |
197 | mp = dp->i_mount; | |
30028030 | 198 | geo = mp->m_dir_geo; |
4a8af273 DC |
199 | /* |
200 | * If the block number in the offset is out of range, we're done. | |
201 | */ | |
7dda6e86 | 202 | if (xfs_dir2_dataptr_to_db(geo, ctx->pos) > geo->datablk) |
4a8af273 DC |
203 | return 0; |
204 | ||
205 | error = xfs_dir3_block_read(NULL, dp, &bp); | |
206 | if (error) | |
207 | return error; | |
208 | ||
209 | /* | |
210 | * Extract the byte offset we start at from the seek pointer. | |
211 | * We'll skip entries before this. | |
212 | */ | |
30028030 | 213 | wantoff = xfs_dir2_dataptr_to_off(geo, ctx->pos); |
4a8af273 DC |
214 | hdr = bp->b_addr; |
215 | xfs_dir3_data_check(dp, bp); | |
216 | /* | |
217 | * Set up values for the loop. | |
218 | */ | |
8f66193c | 219 | btp = xfs_dir2_block_tail_p(geo, hdr); |
2ca98774 | 220 | ptr = (char *)dp->d_ops->data_entry_p(hdr); |
4a8af273 DC |
221 | endptr = (char *)xfs_dir2_block_leaf_p(btp); |
222 | ||
223 | /* | |
224 | * Loop over the data portion of the block. | |
225 | * Each object is a real entry (dep) or an unused one (dup). | |
226 | */ | |
227 | while (ptr < endptr) { | |
0cb97766 DC |
228 | __uint8_t filetype; |
229 | ||
4a8af273 DC |
230 | dup = (xfs_dir2_data_unused_t *)ptr; |
231 | /* | |
232 | * Unused, skip it. | |
233 | */ | |
234 | if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) { | |
235 | ptr += be16_to_cpu(dup->length); | |
236 | continue; | |
237 | } | |
238 | ||
239 | dep = (xfs_dir2_data_entry_t *)ptr; | |
240 | ||
241 | /* | |
242 | * Bump pointer for the next iteration. | |
243 | */ | |
9d23fc85 | 244 | ptr += dp->d_ops->data_entsize(dep->namelen); |
4a8af273 DC |
245 | /* |
246 | * The entry is before the desired starting point, skip it. | |
247 | */ | |
248 | if ((char *)dep - (char *)hdr < wantoff) | |
249 | continue; | |
250 | ||
7dda6e86 | 251 | cook = xfs_dir2_db_off_to_dataptr(geo, geo->datablk, |
4a8af273 DC |
252 | (char *)dep - (char *)hdr); |
253 | ||
254 | ctx->pos = cook & 0x7fffffff; | |
9d23fc85 | 255 | filetype = dp->d_ops->data_get_ftype(dep); |
4a8af273 DC |
256 | /* |
257 | * If it didn't fit, set the final offset to here & return. | |
258 | */ | |
259 | if (!dir_emit(ctx, (char *)dep->name, dep->namelen, | |
0cb97766 DC |
260 | be64_to_cpu(dep->inumber), |
261 | xfs_dir3_get_dtype(mp, filetype))) { | |
4a8af273 DC |
262 | xfs_trans_brelse(NULL, bp); |
263 | return 0; | |
264 | } | |
265 | } | |
266 | ||
267 | /* | |
268 | * Reached the end of the block. | |
269 | * Set the offset to a non-existent block 1 and return. | |
270 | */ | |
7dda6e86 | 271 | ctx->pos = xfs_dir2_db_off_to_dataptr(geo, geo->datablk + 1, 0) & |
4a8af273 DC |
272 | 0x7fffffff; |
273 | xfs_trans_brelse(NULL, bp); | |
274 | return 0; | |
275 | } | |
276 | ||
277 | struct xfs_dir2_leaf_map_info { | |
278 | xfs_extlen_t map_blocks; /* number of fsbs in map */ | |
279 | xfs_dablk_t map_off; /* last mapped file offset */ | |
280 | int map_size; /* total entries in *map */ | |
281 | int map_valid; /* valid entries in *map */ | |
282 | int nmap; /* mappings to ask xfs_bmapi */ | |
283 | xfs_dir2_db_t curdb; /* db for current block */ | |
284 | int ra_current; /* number of read-ahead blks */ | |
285 | int ra_index; /* *map index for read-ahead */ | |
286 | int ra_offset; /* map entry offset for ra */ | |
287 | int ra_want; /* readahead count wanted */ | |
288 | struct xfs_bmbt_irec map[]; /* map vector for blocks */ | |
289 | }; | |
290 | ||
291 | STATIC int | |
292 | xfs_dir2_leaf_readbuf( | |
293 | struct xfs_inode *dp, | |
294 | size_t bufsize, | |
295 | struct xfs_dir2_leaf_map_info *mip, | |
296 | xfs_dir2_off_t *curoff, | |
297 | struct xfs_buf **bpp) | |
298 | { | |
299 | struct xfs_mount *mp = dp->i_mount; | |
300 | struct xfs_buf *bp = *bpp; | |
301 | struct xfs_bmbt_irec *map = mip->map; | |
302 | struct blk_plug plug; | |
303 | int error = 0; | |
304 | int length; | |
305 | int i; | |
306 | int j; | |
30028030 | 307 | struct xfs_da_geometry *geo = mp->m_dir_geo; |
4a8af273 DC |
308 | |
309 | /* | |
310 | * If we have a buffer, we need to release it and | |
311 | * take it out of the mapping. | |
312 | */ | |
313 | ||
314 | if (bp) { | |
315 | xfs_trans_brelse(NULL, bp); | |
316 | bp = NULL; | |
d6cf1305 | 317 | mip->map_blocks -= geo->fsbcount; |
4a8af273 DC |
318 | /* |
319 | * Loop to get rid of the extents for the | |
320 | * directory block. | |
321 | */ | |
d6cf1305 | 322 | for (i = geo->fsbcount; i > 0; ) { |
4a8af273 DC |
323 | j = min_t(int, map->br_blockcount, i); |
324 | map->br_blockcount -= j; | |
325 | map->br_startblock += j; | |
326 | map->br_startoff += j; | |
327 | /* | |
328 | * If mapping is done, pitch it from | |
329 | * the table. | |
330 | */ | |
331 | if (!map->br_blockcount && --mip->map_valid) | |
332 | memmove(&map[0], &map[1], | |
333 | sizeof(map[0]) * mip->map_valid); | |
334 | i -= j; | |
335 | } | |
336 | } | |
337 | ||
338 | /* | |
339 | * Recalculate the readahead blocks wanted. | |
340 | */ | |
8f66193c | 341 | mip->ra_want = howmany(bufsize + geo->blksize, |
4a8af273 DC |
342 | mp->m_sb.sb_blocksize) - 1; |
343 | ASSERT(mip->ra_want >= 0); | |
344 | ||
345 | /* | |
346 | * If we don't have as many as we want, and we haven't | |
347 | * run out of data blocks, get some more mappings. | |
348 | */ | |
349 | if (1 + mip->ra_want > mip->map_blocks && | |
30028030 | 350 | mip->map_off < xfs_dir2_byte_to_da(geo, XFS_DIR2_LEAF_OFFSET)) { |
4a8af273 DC |
351 | /* |
352 | * Get more bmaps, fill in after the ones | |
353 | * we already have in the table. | |
354 | */ | |
355 | mip->nmap = mip->map_size - mip->map_valid; | |
356 | error = xfs_bmapi_read(dp, mip->map_off, | |
30028030 | 357 | xfs_dir2_byte_to_da(geo, XFS_DIR2_LEAF_OFFSET) - |
4a8af273 DC |
358 | mip->map_off, |
359 | &map[mip->map_valid], &mip->nmap, 0); | |
360 | ||
361 | /* | |
362 | * Don't know if we should ignore this or try to return an | |
363 | * error. The trouble with returning errors is that readdir | |
364 | * will just stop without actually passing the error through. | |
365 | */ | |
366 | if (error) | |
367 | goto out; /* XXX */ | |
368 | ||
369 | /* | |
370 | * If we got all the mappings we asked for, set the final map | |
371 | * offset based on the last bmap value received. Otherwise, | |
372 | * we've reached the end. | |
373 | */ | |
374 | if (mip->nmap == mip->map_size - mip->map_valid) { | |
375 | i = mip->map_valid + mip->nmap - 1; | |
376 | mip->map_off = map[i].br_startoff + map[i].br_blockcount; | |
377 | } else | |
30028030 | 378 | mip->map_off = xfs_dir2_byte_to_da(geo, |
4a8af273 DC |
379 | XFS_DIR2_LEAF_OFFSET); |
380 | ||
381 | /* | |
382 | * Look for holes in the mapping, and eliminate them. Count up | |
383 | * the valid blocks. | |
384 | */ | |
385 | for (i = mip->map_valid; i < mip->map_valid + mip->nmap; ) { | |
386 | if (map[i].br_startblock == HOLESTARTBLOCK) { | |
387 | mip->nmap--; | |
388 | length = mip->map_valid + mip->nmap - i; | |
389 | if (length) | |
390 | memmove(&map[i], &map[i + 1], | |
391 | sizeof(map[i]) * length); | |
392 | } else { | |
393 | mip->map_blocks += map[i].br_blockcount; | |
394 | i++; | |
395 | } | |
396 | } | |
397 | mip->map_valid += mip->nmap; | |
398 | } | |
399 | ||
400 | /* | |
401 | * No valid mappings, so no more data blocks. | |
402 | */ | |
403 | if (!mip->map_valid) { | |
30028030 | 404 | *curoff = xfs_dir2_da_to_byte(geo, mip->map_off); |
4a8af273 DC |
405 | goto out; |
406 | } | |
407 | ||
408 | /* | |
409 | * Read the directory block starting at the first mapping. | |
410 | */ | |
30028030 | 411 | mip->curdb = xfs_dir2_da_to_db(geo, map->br_startoff); |
4a8af273 | 412 | error = xfs_dir3_data_read(NULL, dp, map->br_startoff, |
d6cf1305 | 413 | map->br_blockcount >= geo->fsbcount ? |
4a8af273 DC |
414 | XFS_FSB_TO_DADDR(mp, map->br_startblock) : -1, &bp); |
415 | ||
416 | /* | |
417 | * Should just skip over the data block instead of giving up. | |
418 | */ | |
419 | if (error) | |
420 | goto out; /* XXX */ | |
421 | ||
422 | /* | |
423 | * Adjust the current amount of read-ahead: we just read a block that | |
424 | * was previously ra. | |
425 | */ | |
426 | if (mip->ra_current) | |
d6cf1305 | 427 | mip->ra_current -= geo->fsbcount; |
4a8af273 DC |
428 | |
429 | /* | |
430 | * Do we need more readahead? | |
431 | */ | |
432 | blk_start_plug(&plug); | |
433 | for (mip->ra_index = mip->ra_offset = i = 0; | |
434 | mip->ra_want > mip->ra_current && i < mip->map_blocks; | |
d6cf1305 | 435 | i += geo->fsbcount) { |
4a8af273 DC |
436 | ASSERT(mip->ra_index < mip->map_valid); |
437 | /* | |
438 | * Read-ahead a contiguous directory block. | |
439 | */ | |
440 | if (i > mip->ra_current && | |
d6cf1305 | 441 | map[mip->ra_index].br_blockcount >= geo->fsbcount) { |
9df2dd0b | 442 | xfs_dir3_data_readahead(dp, |
4a8af273 DC |
443 | map[mip->ra_index].br_startoff + mip->ra_offset, |
444 | XFS_FSB_TO_DADDR(mp, | |
445 | map[mip->ra_index].br_startblock + | |
446 | mip->ra_offset)); | |
447 | mip->ra_current = i; | |
448 | } | |
449 | ||
450 | /* | |
451 | * Read-ahead a non-contiguous directory block. This doesn't | |
452 | * use our mapping, but this is a very rare case. | |
453 | */ | |
454 | else if (i > mip->ra_current) { | |
9df2dd0b | 455 | xfs_dir3_data_readahead(dp, |
4a8af273 DC |
456 | map[mip->ra_index].br_startoff + |
457 | mip->ra_offset, -1); | |
458 | mip->ra_current = i; | |
459 | } | |
460 | ||
461 | /* | |
462 | * Advance offset through the mapping table. | |
463 | */ | |
d6cf1305 | 464 | for (j = 0; j < geo->fsbcount; j += length ) { |
4a8af273 DC |
465 | /* |
466 | * The rest of this extent but not more than a dir | |
467 | * block. | |
468 | */ | |
d6cf1305 | 469 | length = min_t(int, geo->fsbcount, |
4a8af273 DC |
470 | map[mip->ra_index].br_blockcount - |
471 | mip->ra_offset); | |
4a8af273 DC |
472 | mip->ra_offset += length; |
473 | ||
474 | /* | |
475 | * Advance to the next mapping if this one is used up. | |
476 | */ | |
477 | if (mip->ra_offset == map[mip->ra_index].br_blockcount) { | |
478 | mip->ra_offset = 0; | |
479 | mip->ra_index++; | |
480 | } | |
481 | } | |
482 | } | |
483 | blk_finish_plug(&plug); | |
484 | ||
485 | out: | |
486 | *bpp = bp; | |
487 | return error; | |
488 | } | |
489 | ||
490 | /* | |
491 | * Getdents (readdir) for leaf and node directories. | |
492 | * This reads the data blocks only, so is the same for both forms. | |
493 | */ | |
494 | STATIC int | |
495 | xfs_dir2_leaf_getdents( | |
496 | xfs_inode_t *dp, /* incore directory inode */ | |
497 | struct dir_context *ctx, | |
498 | size_t bufsize) | |
499 | { | |
500 | struct xfs_buf *bp = NULL; /* data block buffer */ | |
501 | xfs_dir2_data_hdr_t *hdr; /* data block header */ | |
502 | xfs_dir2_data_entry_t *dep; /* data entry */ | |
503 | xfs_dir2_data_unused_t *dup; /* unused entry */ | |
504 | int error = 0; /* error return value */ | |
505 | int length; /* temporary length value */ | |
506 | xfs_mount_t *mp; /* filesystem mount point */ | |
507 | int byteoff; /* offset in current block */ | |
508 | xfs_dir2_off_t curoff; /* current overall offset */ | |
509 | xfs_dir2_off_t newoff; /* new curoff after new blk */ | |
510 | char *ptr = NULL; /* pointer to current data */ | |
511 | struct xfs_dir2_leaf_map_info *map_info; | |
30028030 | 512 | struct xfs_da_geometry *geo; |
4a8af273 DC |
513 | |
514 | /* | |
515 | * If the offset is at or past the largest allowed value, | |
516 | * give up right away. | |
517 | */ | |
518 | if (ctx->pos >= XFS_DIR2_MAX_DATAPTR) | |
519 | return 0; | |
520 | ||
521 | mp = dp->i_mount; | |
30028030 | 522 | geo = mp->m_dir_geo; |
4a8af273 DC |
523 | |
524 | /* | |
525 | * Set up to bmap a number of blocks based on the caller's | |
526 | * buffer size, the directory block size, and the filesystem | |
527 | * block size. | |
528 | */ | |
8f66193c | 529 | length = howmany(bufsize + geo->blksize, mp->m_sb.sb_blocksize); |
4a8af273 DC |
530 | map_info = kmem_zalloc(offsetof(struct xfs_dir2_leaf_map_info, map) + |
531 | (length * sizeof(struct xfs_bmbt_irec)), | |
532 | KM_SLEEP | KM_NOFS); | |
533 | map_info->map_size = length; | |
534 | ||
535 | /* | |
536 | * Inside the loop we keep the main offset value as a byte offset | |
537 | * in the directory file. | |
538 | */ | |
25994053 | 539 | curoff = xfs_dir2_dataptr_to_byte(ctx->pos); |
4a8af273 DC |
540 | |
541 | /* | |
542 | * Force this conversion through db so we truncate the offset | |
543 | * down to get the start of the data block. | |
544 | */ | |
30028030 DC |
545 | map_info->map_off = xfs_dir2_db_to_da(geo, |
546 | xfs_dir2_byte_to_db(geo, curoff)); | |
4a8af273 DC |
547 | |
548 | /* | |
549 | * Loop over directory entries until we reach the end offset. | |
550 | * Get more blocks and readahead as necessary. | |
551 | */ | |
552 | while (curoff < XFS_DIR2_LEAF_OFFSET) { | |
0cb97766 DC |
553 | __uint8_t filetype; |
554 | ||
4a8af273 DC |
555 | /* |
556 | * If we have no buffer, or we're off the end of the | |
557 | * current buffer, need to get another one. | |
558 | */ | |
8f66193c | 559 | if (!bp || ptr >= (char *)bp->b_addr + geo->blksize) { |
4a8af273 DC |
560 | |
561 | error = xfs_dir2_leaf_readbuf(dp, bufsize, map_info, | |
562 | &curoff, &bp); | |
563 | if (error || !map_info->map_valid) | |
564 | break; | |
565 | ||
566 | /* | |
567 | * Having done a read, we need to set a new offset. | |
568 | */ | |
9b3b5522 DC |
569 | newoff = xfs_dir2_db_off_to_byte(mp->m_dir_geo, |
570 | map_info->curdb, 0); | |
4a8af273 DC |
571 | /* |
572 | * Start of the current block. | |
573 | */ | |
574 | if (curoff < newoff) | |
575 | curoff = newoff; | |
576 | /* | |
577 | * Make sure we're in the right block. | |
578 | */ | |
579 | else if (curoff > newoff) | |
30028030 | 580 | ASSERT(xfs_dir2_byte_to_db(geo, curoff) == |
4a8af273 DC |
581 | map_info->curdb); |
582 | hdr = bp->b_addr; | |
583 | xfs_dir3_data_check(dp, bp); | |
584 | /* | |
585 | * Find our position in the block. | |
586 | */ | |
2ca98774 | 587 | ptr = (char *)dp->d_ops->data_entry_p(hdr); |
9b3b5522 | 588 | byteoff = xfs_dir2_byte_to_off(mp->m_dir_geo, curoff); |
4a8af273 DC |
589 | /* |
590 | * Skip past the header. | |
591 | */ | |
592 | if (byteoff == 0) | |
1c9a5b2e | 593 | curoff += dp->d_ops->data_entry_offset; |
4a8af273 DC |
594 | /* |
595 | * Skip past entries until we reach our offset. | |
596 | */ | |
597 | else { | |
598 | while ((char *)ptr - (char *)hdr < byteoff) { | |
599 | dup = (xfs_dir2_data_unused_t *)ptr; | |
600 | ||
601 | if (be16_to_cpu(dup->freetag) | |
602 | == XFS_DIR2_DATA_FREE_TAG) { | |
603 | ||
604 | length = be16_to_cpu(dup->length); | |
605 | ptr += length; | |
606 | continue; | |
607 | } | |
608 | dep = (xfs_dir2_data_entry_t *)ptr; | |
609 | length = | |
9d23fc85 | 610 | dp->d_ops->data_entsize(dep->namelen); |
4a8af273 DC |
611 | ptr += length; |
612 | } | |
613 | /* | |
614 | * Now set our real offset. | |
615 | */ | |
616 | curoff = | |
30028030 DC |
617 | xfs_dir2_db_off_to_byte(geo, |
618 | xfs_dir2_byte_to_db(geo, curoff), | |
4a8af273 | 619 | (char *)ptr - (char *)hdr); |
8f66193c | 620 | if (ptr >= (char *)hdr + geo->blksize) { |
4a8af273 DC |
621 | continue; |
622 | } | |
623 | } | |
624 | } | |
625 | /* | |
626 | * We have a pointer to an entry. | |
627 | * Is it a live one? | |
628 | */ | |
629 | dup = (xfs_dir2_data_unused_t *)ptr; | |
630 | /* | |
631 | * No, it's unused, skip over it. | |
632 | */ | |
633 | if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) { | |
634 | length = be16_to_cpu(dup->length); | |
635 | ptr += length; | |
636 | curoff += length; | |
637 | continue; | |
638 | } | |
639 | ||
640 | dep = (xfs_dir2_data_entry_t *)ptr; | |
9d23fc85 DC |
641 | length = dp->d_ops->data_entsize(dep->namelen); |
642 | filetype = dp->d_ops->data_get_ftype(dep); | |
4a8af273 | 643 | |
25994053 | 644 | ctx->pos = xfs_dir2_byte_to_dataptr(curoff) & 0x7fffffff; |
4a8af273 | 645 | if (!dir_emit(ctx, (char *)dep->name, dep->namelen, |
0cb97766 DC |
646 | be64_to_cpu(dep->inumber), |
647 | xfs_dir3_get_dtype(mp, filetype))) | |
4a8af273 DC |
648 | break; |
649 | ||
650 | /* | |
651 | * Advance to next entry in the block. | |
652 | */ | |
653 | ptr += length; | |
654 | curoff += length; | |
655 | /* bufsize may have just been a guess; don't go negative */ | |
656 | bufsize = bufsize > length ? bufsize - length : 0; | |
657 | } | |
658 | ||
659 | /* | |
660 | * All done. Set output offset value to current offset. | |
661 | */ | |
25994053 | 662 | if (curoff > xfs_dir2_dataptr_to_byte(XFS_DIR2_MAX_DATAPTR)) |
4a8af273 DC |
663 | ctx->pos = XFS_DIR2_MAX_DATAPTR & 0x7fffffff; |
664 | else | |
25994053 | 665 | ctx->pos = xfs_dir2_byte_to_dataptr(curoff) & 0x7fffffff; |
4a8af273 DC |
666 | kmem_free(map_info); |
667 | if (bp) | |
668 | xfs_trans_brelse(NULL, bp); | |
669 | return error; | |
670 | } | |
671 | ||
672 | /* | |
673 | * Read a directory. | |
674 | */ | |
675 | int | |
676 | xfs_readdir( | |
677 | xfs_inode_t *dp, | |
678 | struct dir_context *ctx, | |
679 | size_t bufsize) | |
680 | { | |
681 | int rval; /* return value */ | |
682 | int v; /* type-checking value */ | |
40194ecc | 683 | uint lock_mode; |
4a8af273 DC |
684 | |
685 | trace_xfs_readdir(dp); | |
686 | ||
687 | if (XFS_FORCED_SHUTDOWN(dp->i_mount)) | |
688 | return XFS_ERROR(EIO); | |
689 | ||
690 | ASSERT(S_ISDIR(dp->i_d.di_mode)); | |
691 | XFS_STATS_INC(xs_dir_getdents); | |
692 | ||
40194ecc | 693 | lock_mode = xfs_ilock_data_map_shared(dp); |
4a8af273 DC |
694 | if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL) |
695 | rval = xfs_dir2_sf_getdents(dp, ctx); | |
7fb2cd4d | 696 | else if ((rval = xfs_dir2_isblock(dp, &v))) |
4a8af273 DC |
697 | ; |
698 | else if (v) | |
699 | rval = xfs_dir2_block_getdents(dp, ctx); | |
700 | else | |
701 | rval = xfs_dir2_leaf_getdents(dp, ctx, bufsize); | |
40194ecc BM |
702 | xfs_iunlock(dp, lock_mode); |
703 | ||
4a8af273 DC |
704 | return rval; |
705 | } |