Line data Source code
1 : // SPDX-License-Identifier: GPL-2.0
2 : /*
3 : * Copyright (c) 2000-2005 Silicon Graphics, Inc.
4 : * Copyright (c) 2013 Red Hat, Inc.
5 : * All Rights Reserved.
6 : */
7 : #include "xfs.h"
8 : #include "xfs_fs.h"
9 : #include "xfs_shared.h"
10 : #include "xfs_format.h"
11 : #include "xfs_log_format.h"
12 : #include "xfs_trans_resv.h"
13 : #include "xfs_mount.h"
14 : #include "xfs_inode.h"
15 : #include "xfs_dir2.h"
16 : #include "xfs_dir2_priv.h"
17 : #include "xfs_trace.h"
18 : #include "xfs_bmap.h"
19 : #include "xfs_trans.h"
20 : #include "xfs_error.h"
21 :
22 : /*
23 : * Directory file type support functions
24 : */
25 : static unsigned char xfs_dir3_filetype_table[] = {
26 : DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK,
27 : DT_FIFO, DT_SOCK, DT_LNK, DT_WHT,
28 : };
29 :
30 : unsigned char
31 0 : xfs_dir3_get_dtype(
32 : struct xfs_mount *mp,
33 : uint8_t filetype)
34 : {
35 0 : if (!xfs_has_ftype(mp))
36 : return DT_UNKNOWN;
37 :
38 19157939023 : if (filetype >= XFS_DIR3_FT_MAX)
39 : return DT_UNKNOWN;
40 :
41 19157939023 : return xfs_dir3_filetype_table[filetype];
42 : }
43 :
44 : STATIC int
45 126897517 : xfs_dir2_sf_getdents(
46 : struct xfs_da_args *args,
47 : struct dir_context *ctx)
48 : {
49 126897517 : int i; /* shortform entry number */
50 126897517 : struct xfs_inode *dp = args->dp; /* incore directory inode */
51 126897517 : struct xfs_mount *mp = dp->i_mount;
52 126897517 : xfs_dir2_dataptr_t off; /* current entry's offset */
53 126897517 : xfs_dir2_sf_entry_t *sfep; /* shortform directory entry */
54 126897517 : xfs_dir2_sf_hdr_t *sfp; /* shortform structure */
55 126897517 : xfs_dir2_dataptr_t dot_offset;
56 126897517 : xfs_dir2_dataptr_t dotdot_offset;
57 126897517 : xfs_ino_t ino;
58 126897517 : struct xfs_da_geometry *geo = args->geo;
59 :
60 126897517 : ASSERT(dp->i_df.if_format == XFS_DINODE_FMT_LOCAL);
61 126897517 : ASSERT(dp->i_df.if_bytes == dp->i_disk_size);
62 126897517 : ASSERT(dp->i_df.if_u1.if_data != NULL);
63 :
64 126897517 : sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
65 :
66 : /*
67 : * If the block number in the offset is out of range, we're done.
68 : */
69 126897517 : if (xfs_dir2_dataptr_to_db(geo, ctx->pos) > geo->datablk)
70 : return 0;
71 :
72 : /*
73 : * Precalculate offsets for "." and ".." as we will always need them.
74 : * This relies on the fact that directories always start with the
75 : * entries for "." and "..".
76 : */
77 65243437 : dot_offset = xfs_dir2_db_off_to_dataptr(geo, geo->datablk,
78 65243437 : geo->data_entry_offset);
79 65243672 : dotdot_offset = xfs_dir2_db_off_to_dataptr(geo, geo->datablk,
80 65243672 : geo->data_entry_offset +
81 : xfs_dir2_data_entsize(mp, sizeof(".") - 1));
82 :
83 : /*
84 : * Put . entry unless we're starting past it.
85 : */
86 65230531 : if (ctx->pos <= dot_offset) {
87 65244448 : ctx->pos = dot_offset & 0x7fffffff;
88 65244448 : if (!dir_emit(ctx, ".", 1, dp->i_ino, DT_DIR))
89 : return 0;
90 : }
91 :
92 : /*
93 : * Put .. entry unless we're starting past it.
94 : */
95 65228622 : if (ctx->pos <= dotdot_offset) {
96 65241726 : ino = xfs_dir2_sf_get_parent_ino(sfp);
97 65236803 : ctx->pos = dotdot_offset & 0x7fffffff;
98 65236803 : if (!dir_emit(ctx, "..", 2, ino, DT_DIR))
99 : return 0;
100 : }
101 :
102 : /*
103 : * Loop while there are more entries and put'ing works.
104 : */
105 65229157 : sfep = xfs_dir2_sf_firstentry(sfp);
106 285151342 : for (i = 0; i < sfp->count; i++) {
107 223434279 : uint8_t filetype;
108 :
109 223434279 : off = xfs_dir2_db_off_to_dataptr(geo, geo->datablk,
110 : xfs_dir2_sf_get_offset(sfep));
111 :
112 223433360 : if (ctx->pos > off) {
113 2 : sfep = xfs_dir2_sf_nextentry(mp, sfp, sfep);
114 2 : continue;
115 : }
116 :
117 223433358 : ino = xfs_dir2_sf_get_ino(mp, sfp, sfep);
118 223428847 : filetype = xfs_dir2_sf_get_ftype(mp, sfep);
119 223437980 : ctx->pos = off & 0x7fffffff;
120 223437980 : if (XFS_IS_CORRUPT(dp->i_mount,
121 : !xfs_dir2_namecheck(sfep->name,
122 : sfep->namelen)))
123 4 : return -EFSCORRUPTED;
124 446848668 : if (!dir_emit(ctx, (char *)sfep->name, sfep->namelen, ino,
125 : xfs_dir3_get_dtype(mp, filetype)))
126 : return 0;
127 219954579 : sfep = xfs_dir2_sf_nextentry(mp, sfp, sfep);
128 : }
129 :
130 61717063 : ctx->pos = xfs_dir2_db_off_to_dataptr(geo, geo->datablk + 1, 0) &
131 : 0x7fffffff;
132 61736486 : return 0;
133 : }
134 :
135 : /*
136 : * Readdir for block directories.
137 : */
138 : STATIC int
139 673046 : xfs_dir2_block_getdents(
140 : struct xfs_da_args *args,
141 : struct dir_context *ctx,
142 : unsigned int *lock_mode)
143 : {
144 673046 : struct xfs_inode *dp = args->dp; /* incore directory inode */
145 673046 : struct xfs_buf *bp; /* buffer for block */
146 673046 : int error; /* error return value */
147 673046 : int wantoff; /* starting block offset */
148 673046 : xfs_off_t cook;
149 673046 : struct xfs_da_geometry *geo = args->geo;
150 673046 : unsigned int offset, next_offset;
151 673046 : unsigned int end;
152 :
153 : /*
154 : * If the block number in the offset is out of range, we're done.
155 : */
156 673046 : if (xfs_dir2_dataptr_to_db(geo, ctx->pos) > geo->datablk)
157 : return 0;
158 :
159 381924 : error = xfs_dir3_block_read(args->trans, dp, &bp);
160 381923 : if (error)
161 : return error;
162 :
163 381923 : xfs_iunlock(dp, *lock_mode);
164 381928 : *lock_mode = 0;
165 :
166 : /*
167 : * Extract the byte offset we start at from the seek pointer.
168 : * We'll skip entries before this.
169 : */
170 381928 : wantoff = xfs_dir2_dataptr_to_off(geo, ctx->pos);
171 381928 : xfs_dir3_data_check(dp, bp);
172 :
173 : /*
174 : * Loop over the data portion of the block.
175 : * Each object is a real entry (dep) or an unused one (dup).
176 : */
177 381915 : end = xfs_dir3_data_end_offset(geo, bp->b_addr);
178 381917 : for (offset = geo->data_entry_offset;
179 30391524 : offset < end;
180 : offset = next_offset) {
181 30095691 : struct xfs_dir2_data_unused *dup = bp->b_addr + offset;
182 30095691 : struct xfs_dir2_data_entry *dep = bp->b_addr + offset;
183 30095691 : uint8_t filetype;
184 :
185 : /*
186 : * Unused, skip it.
187 : */
188 30095691 : if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
189 5629343 : next_offset = offset + be16_to_cpu(dup->length);
190 5629343 : continue;
191 : }
192 :
193 : /*
194 : * Bump pointer for the next iteration.
195 : */
196 48932696 : next_offset = offset +
197 24466348 : xfs_dir2_data_entsize(dp->i_mount, dep->namelen);
198 :
199 : /*
200 : * The entry is before the desired starting point, skip it.
201 : */
202 24466348 : if (offset < wantoff)
203 131959 : continue;
204 :
205 24334389 : cook = xfs_dir2_db_off_to_dataptr(geo, geo->datablk, offset);
206 :
207 24287274 : ctx->pos = cook & 0x7fffffff;
208 24287274 : filetype = xfs_dir2_data_get_ftype(dp->i_mount, dep);
209 : /*
210 : * If it didn't fit, set the final offset to here & return.
211 : */
212 24314632 : if (XFS_IS_CORRUPT(dp->i_mount,
213 : !xfs_dir2_namecheck(dep->name,
214 : dep->namelen))) {
215 0 : error = -EFSCORRUPTED;
216 0 : goto out_rele;
217 : }
218 24296713 : if (!dir_emit(ctx, (char *)dep->name, dep->namelen,
219 24295807 : be64_to_cpu(dep->inumber),
220 24295807 : xfs_dir3_get_dtype(dp->i_mount, filetype)))
221 86096 : goto out_rele;
222 : }
223 :
224 : /*
225 : * Reached the end of the block.
226 : * Set the offset to a non-existent block 1 and return.
227 : */
228 295833 : ctx->pos = xfs_dir2_db_off_to_dataptr(geo, geo->datablk + 1, 0) &
229 : 0x7fffffff;
230 381929 : out_rele:
231 381929 : xfs_trans_brelse(args->trans, bp);
232 381929 : return error;
233 : }
234 :
235 : /*
236 : * Read a directory block and initiate readahead for blocks beyond that.
237 : * We maintain a sliding readahead window of the remaining space in the
238 : * buffer rounded up to the nearest block.
239 : */
240 : STATIC int
241 113712162 : xfs_dir2_leaf_readbuf(
242 : struct xfs_da_args *args,
243 : size_t bufsize,
244 : xfs_dir2_off_t *cur_off,
245 : xfs_dablk_t *ra_blk,
246 : struct xfs_buf **bpp)
247 : {
248 113712162 : struct xfs_inode *dp = args->dp;
249 113712162 : struct xfs_buf *bp = NULL;
250 113712162 : struct xfs_da_geometry *geo = args->geo;
251 113712162 : struct xfs_ifork *ifp = xfs_ifork_ptr(dp, XFS_DATA_FORK);
252 113712162 : struct xfs_bmbt_irec map;
253 113712162 : struct blk_plug plug;
254 113712162 : xfs_dir2_off_t new_off;
255 113712162 : xfs_dablk_t next_ra;
256 113712162 : xfs_dablk_t map_off;
257 113712162 : xfs_dablk_t last_da;
258 113712162 : struct xfs_iext_cursor icur;
259 113712162 : int ra_want;
260 113712162 : int error = 0;
261 :
262 113712162 : error = xfs_iread_extents(args->trans, dp, XFS_DATA_FORK);
263 113719368 : if (error)
264 0 : goto out;
265 :
266 : /*
267 : * Look for mapped directory blocks at or above the current offset.
268 : * Truncate down to the nearest directory block to start the scanning
269 : * operation.
270 : */
271 113719368 : last_da = xfs_dir2_byte_to_da(geo, XFS_DIR2_LEAF_OFFSET);
272 113743508 : map_off = xfs_dir2_db_to_da(geo, xfs_dir2_byte_to_db(geo, *cur_off));
273 113743649 : if (!xfs_iext_lookup_extent(dp, ifp, map_off, &icur, &map))
274 0 : goto out;
275 113749412 : if (map.br_startoff >= last_da)
276 10186975 : goto out;
277 103562437 : xfs_trim_extent(&map, map_off, last_da - map_off);
278 :
279 : /* Read the directory block of that first mapping. */
280 103556785 : new_off = xfs_dir2_da_to_byte(geo, map.br_startoff);
281 103564942 : if (new_off > *cur_off)
282 635 : *cur_off = new_off;
283 103564942 : error = xfs_dir3_data_read(args->trans, dp, map.br_startoff, 0, &bp);
284 103560577 : if (error)
285 1411 : goto out;
286 :
287 : /*
288 : * Start readahead for the next bufsize's worth of dir data blocks.
289 : * We may have already issued readahead for some of that range;
290 : * ra_blk tracks the last block we tried to read(ahead).
291 : */
292 103559166 : ra_want = howmany(bufsize + geo->blksize, (1 << geo->fsblog));
293 103559166 : if (*ra_blk >= last_da)
294 18319602 : goto out;
295 85239564 : else if (*ra_blk == 0)
296 10879142 : *ra_blk = map.br_startoff;
297 85239564 : next_ra = map.br_startoff + geo->fsbcount;
298 85239564 : if (next_ra >= last_da)
299 0 : goto out_no_ra;
300 85239564 : if (map.br_blockcount < geo->fsbcount &&
301 0 : !xfs_iext_next_extent(ifp, &icur, &map))
302 0 : goto out_no_ra;
303 85239564 : if (map.br_startoff >= last_da)
304 0 : goto out_no_ra;
305 85239564 : xfs_trim_extent(&map, next_ra, last_da - next_ra);
306 :
307 : /* Start ra for each dir (not fs) block that has a mapping. */
308 85245039 : blk_start_plug(&plug);
309 558303629 : while (ra_want > 0) {
310 478377913 : next_ra = roundup((xfs_dablk_t)map.br_startoff, geo->fsbcount);
311 860850242 : while (ra_want > 0 &&
312 780937249 : next_ra < map.br_startoff + map.br_blockcount) {
313 460309160 : if (next_ra >= last_da) {
314 77886058 : *ra_blk = last_da;
315 77886058 : break;
316 : }
317 382423102 : if (next_ra > *ra_blk) {
318 98498106 : xfs_dir3_data_readahead(dp, next_ra,
319 : XFS_DABUF_MAP_HOLE_OK);
320 98547333 : *ra_blk = next_ra;
321 : }
322 382472329 : ra_want -= geo->fsbcount;
323 382472329 : next_ra += geo->fsbcount;
324 : }
325 478427140 : if (!xfs_iext_next_extent(ifp, &icur, &map)) {
326 5330872 : *ra_blk = last_da;
327 5330872 : break;
328 : }
329 : }
330 85246759 : blk_finish_plug(&plug);
331 :
332 113751527 : out:
333 113751527 : *bpp = bp;
334 113751527 : return error;
335 0 : out_no_ra:
336 0 : *ra_blk = last_da;
337 0 : goto out;
338 : }
339 :
340 : /*
341 : * Getdents (readdir) for leaf and node directories.
342 : * This reads the data blocks only, so is the same for both forms.
343 : */
344 : STATIC int
345 15989192 : xfs_dir2_leaf_getdents(
346 : struct xfs_da_args *args,
347 : struct dir_context *ctx,
348 : size_t bufsize,
349 : unsigned int *lock_mode)
350 : {
351 15989192 : struct xfs_inode *dp = args->dp;
352 15989192 : struct xfs_mount *mp = dp->i_mount;
353 15989192 : struct xfs_buf *bp = NULL; /* data block buffer */
354 15989192 : xfs_dir2_data_entry_t *dep; /* data entry */
355 15989192 : xfs_dir2_data_unused_t *dup; /* unused entry */
356 15989192 : struct xfs_da_geometry *geo = args->geo;
357 15989192 : xfs_dablk_t rablk = 0; /* current readahead block */
358 15989192 : xfs_dir2_off_t curoff; /* current overall offset */
359 15989192 : int length; /* temporary length value */
360 15989192 : int byteoff; /* offset in current block */
361 15989192 : unsigned int offset = 0;
362 15989192 : int error = 0; /* error return value */
363 :
364 : /*
365 : * If the offset is at or past the largest allowed value,
366 : * give up right away.
367 : */
368 15989192 : if (ctx->pos >= XFS_DIR2_MAX_DATAPTR)
369 : return 0;
370 :
371 : /*
372 : * Inside the loop we keep the main offset value as a byte offset
373 : * in the directory file.
374 : */
375 15989192 : curoff = xfs_dir2_dataptr_to_byte(ctx->pos);
376 :
377 : /*
378 : * Loop over directory entries until we reach the end offset.
379 : * Get more blocks and readahead as necessary.
380 : */
381 20117122249 : while (curoff < XFS_DIR2_LEAF_OFFSET) {
382 20117122249 : uint8_t filetype;
383 :
384 : /*
385 : * If we have no buffer, or we're off the end of the
386 : * current buffer, need to get another one.
387 : */
388 20117122249 : if (!bp || offset >= geo->blksize) {
389 24353506 : if (bp) {
390 97744251 : xfs_trans_brelse(args->trans, bp);
391 97767238 : bp = NULL;
392 : }
393 :
394 24357932 : if (*lock_mode == 0)
395 97766718 : *lock_mode = xfs_ilock_data_map_shared(dp);
396 24358022 : error = xfs_dir2_leaf_readbuf(args, bufsize, &curoff,
397 : &rablk, &bp);
398 113722162 : if (error || !bp)
399 : break;
400 :
401 103534396 : xfs_iunlock(dp, *lock_mode);
402 103563397 : *lock_mode = 0;
403 :
404 103563397 : xfs_dir3_data_check(dp, bp);
405 : /*
406 : * Find our position in the block.
407 : */
408 103551997 : offset = geo->data_entry_offset;
409 103551997 : byteoff = xfs_dir2_byte_to_off(geo, curoff);
410 : /*
411 : * Skip past the header.
412 : */
413 103551997 : if (byteoff == 0)
414 97893702 : curoff += geo->data_entry_offset;
415 : /*
416 : * Skip past entries until we reach our offset.
417 : */
418 : else {
419 556470644 : while (offset < byteoff) {
420 550812349 : dup = bp->b_addr + offset;
421 :
422 550812349 : if (be16_to_cpu(dup->freetag)
423 550812349 : == XFS_DIR2_DATA_FREE_TAG) {
424 :
425 17889792 : length = be16_to_cpu(dup->length);
426 17889792 : offset += length;
427 17889792 : continue;
428 : }
429 532922557 : dep = bp->b_addr + offset;
430 532922557 : length = xfs_dir2_data_entsize(mp,
431 532922557 : dep->namelen);
432 532922557 : offset += length;
433 : }
434 : /*
435 : * Now set our real offset.
436 : */
437 11316576 : curoff =
438 5658295 : xfs_dir2_db_off_to_byte(geo,
439 : xfs_dir2_byte_to_db(geo, curoff),
440 : offset);
441 5658281 : if (offset >= geo->blksize)
442 18537 : continue;
443 : }
444 : }
445 :
446 : /*
447 : * We have a pointer to an entry. Is it a live one?
448 : */
449 20235739005 : dup = bp->b_addr + offset;
450 :
451 : /*
452 : * No, it's unused, skip over it.
453 : */
454 20235739005 : if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
455 1314933724 : length = be16_to_cpu(dup->length);
456 1314933724 : offset += length;
457 1314933724 : curoff += length;
458 1314933724 : continue;
459 : }
460 :
461 18920805281 : dep = bp->b_addr + offset;
462 18920805281 : length = xfs_dir2_data_entsize(mp, dep->namelen);
463 18920805281 : filetype = xfs_dir2_data_get_ftype(mp, dep);
464 :
465 18938216172 : ctx->pos = xfs_dir2_byte_to_dataptr(curoff) & 0x7fffffff;
466 18938216172 : if (XFS_IS_CORRUPT(dp->i_mount,
467 : !xfs_dir2_namecheck(dep->name,
468 : dep->namelen))) {
469 : error = -EFSCORRUPTED;
470 : break;
471 : }
472 18381329833 : if (!dir_emit(ctx, (char *)dep->name, dep->namelen,
473 18380194107 : be64_to_cpu(dep->inumber),
474 18380194107 : xfs_dir3_get_dtype(dp->i_mount, filetype)))
475 : break;
476 :
477 : /*
478 : * Advance to next entry in the block.
479 : */
480 18786180796 : offset += length;
481 18786180796 : curoff += length;
482 : /* bufsize may have just been a guess; don't go negative */
483 18786180796 : bufsize = bufsize > length ? bufsize - length : 0;
484 : }
485 :
486 : /*
487 : * All done. Set output offset value to current offset.
488 : */
489 15989080 : if (curoff > xfs_dir2_dataptr_to_byte(XFS_DIR2_MAX_DATAPTR))
490 0 : ctx->pos = XFS_DIR2_MAX_DATAPTR & 0x7fffffff;
491 : else
492 15989080 : ctx->pos = xfs_dir2_byte_to_dataptr(curoff) & 0x7fffffff;
493 15989080 : if (bp)
494 5801063 : xfs_trans_brelse(args->trans, bp);
495 : return error;
496 : }
497 :
498 : /*
499 : * Read a directory.
500 : *
501 : * If supplied, the transaction collects locked dir buffers to avoid
502 : * nested buffer deadlocks. This function does not dirty the
503 : * transaction. The caller must hold the IOLOCK (shared or exclusive)
504 : * before calling this function.
505 : */
506 : int
507 143528352 : xfs_readdir(
508 : struct xfs_trans *tp,
509 : struct xfs_inode *dp,
510 : struct dir_context *ctx,
511 : size_t bufsize)
512 : {
513 143528352 : struct xfs_da_args args = { NULL };
514 143528352 : unsigned int lock_mode;
515 143528352 : bool isblock;
516 143528352 : int error;
517 :
518 143528352 : trace_xfs_readdir(dp);
519 :
520 287115278 : if (xfs_is_shutdown(dp->i_mount))
521 : return -EIO;
522 :
523 143557566 : ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
524 143557566 : ASSERT(xfs_isilocked(dp, XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL));
525 143569850 : XFS_STATS_INC(dp->i_mount, xs_dir_getdents);
526 :
527 143575623 : args.dp = dp;
528 143575623 : args.geo = dp->i_mount->m_dir_geo;
529 143575623 : args.trans = tp;
530 :
531 143575623 : if (dp->i_df.if_format == XFS_DINODE_FMT_LOCAL)
532 126913814 : return xfs_dir2_sf_getdents(&args, ctx);
533 :
534 16661809 : lock_mode = xfs_ilock_data_map_shared(dp);
535 16662371 : error = xfs_dir2_isblock(&args, &isblock);
536 16662427 : if (error)
537 0 : goto out_unlock;
538 :
539 16662427 : if (isblock) {
540 672652 : error = xfs_dir2_block_getdents(&args, ctx, &lock_mode);
541 672708 : goto out_unlock;
542 : }
543 :
544 15989775 : error = xfs_dir2_leaf_getdents(&args, ctx, bufsize, &lock_mode);
545 :
546 16661509 : out_unlock:
547 16661509 : if (lock_mode)
548 10479860 : xfs_iunlock(dp, lock_mode);
549 : return error;
550 : }
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