2 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
3 * Copyright (c) 2013 Red Hat, Inc.
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.
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.
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
21 #include "xfs_format.h"
22 #include "xfs_log_format.h"
23 #include "xfs_trans_resv.h"
25 #include "xfs_mount.h"
26 #include "xfs_da_format.h"
27 #include "xfs_da_btree.h"
28 #include "xfs_inode.h"
30 #include "xfs_dir2_priv.h"
31 #include "xfs_error.h"
32 #include "xfs_trace.h"
34 #include "xfs_trans.h"
37 * Directory file type support functions
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,
49 if (!xfs_sb_version_hasftype(&mp->m_sb))
52 if (filetype >= XFS_DIR3_FT_MAX)
55 return xfs_dir3_filetype_table[filetype];
60 struct xfs_da_args *args,
61 struct dir_context *ctx)
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;
71 struct xfs_da_geometry *geo = args->geo;
73 ASSERT(dp->i_df.if_flags & XFS_IFINLINE);
74 ASSERT(dp->i_df.if_bytes == dp->i_d.di_size);
75 ASSERT(dp->i_df.if_u1.if_data != NULL);
77 sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
80 * If the block number in the offset is out of range, we're done.
82 if (xfs_dir2_dataptr_to_db(geo, ctx->pos) > geo->datablk)
86 * Precalculate offsets for . and .. as we will always need them.
88 * XXX(hch): the second argument is sometimes 0 and sometimes
91 dot_offset = xfs_dir2_db_off_to_dataptr(geo, geo->datablk,
92 dp->d_ops->data_dot_offset);
93 dotdot_offset = xfs_dir2_db_off_to_dataptr(geo, geo->datablk,
94 dp->d_ops->data_dotdot_offset);
97 * Put . entry unless we're starting past it.
99 if (ctx->pos <= dot_offset) {
100 ctx->pos = dot_offset & 0x7fffffff;
101 if (!dir_emit(ctx, ".", 1, dp->i_ino, DT_DIR))
106 * Put .. entry unless we're starting past it.
108 if (ctx->pos <= dotdot_offset) {
109 ino = dp->d_ops->sf_get_parent_ino(sfp);
110 ctx->pos = dotdot_offset & 0x7fffffff;
111 if (!dir_emit(ctx, "..", 2, ino, DT_DIR))
116 * Loop while there are more entries and put'ing works.
118 sfep = xfs_dir2_sf_firstentry(sfp);
119 for (i = 0; i < sfp->count; i++) {
122 off = xfs_dir2_db_off_to_dataptr(geo, geo->datablk,
123 xfs_dir2_sf_get_offset(sfep));
125 if (ctx->pos > off) {
126 sfep = dp->d_ops->sf_nextentry(sfp, sfep);
130 ino = dp->d_ops->sf_get_ino(sfp, sfep);
131 filetype = dp->d_ops->sf_get_ftype(sfep);
132 ctx->pos = off & 0x7fffffff;
133 if (!dir_emit(ctx, (char *)sfep->name, sfep->namelen, ino,
134 xfs_dir3_get_dtype(dp->i_mount, filetype)))
136 sfep = dp->d_ops->sf_nextentry(sfp, sfep);
139 ctx->pos = xfs_dir2_db_off_to_dataptr(geo, geo->datablk + 1, 0) &
145 * Readdir for block directories.
148 xfs_dir2_block_getdents(
149 struct xfs_da_args *args,
150 struct dir_context *ctx)
152 struct xfs_inode *dp = args->dp; /* incore directory inode */
153 xfs_dir2_data_hdr_t *hdr; /* block header */
154 struct xfs_buf *bp; /* buffer for block */
155 xfs_dir2_block_tail_t *btp; /* block tail */
156 xfs_dir2_data_entry_t *dep; /* block data entry */
157 xfs_dir2_data_unused_t *dup; /* block unused entry */
158 char *endptr; /* end of the data entries */
159 int error; /* error return value */
160 char *ptr; /* current data entry */
161 int wantoff; /* starting block offset */
163 struct xfs_da_geometry *geo = args->geo;
167 * If the block number in the offset is out of range, we're done.
169 if (xfs_dir2_dataptr_to_db(geo, ctx->pos) > geo->datablk)
172 lock_mode = xfs_ilock_data_map_shared(dp);
173 error = xfs_dir3_block_read(NULL, dp, &bp);
174 xfs_iunlock(dp, lock_mode);
179 * Extract the byte offset we start at from the seek pointer.
180 * We'll skip entries before this.
182 wantoff = xfs_dir2_dataptr_to_off(geo, ctx->pos);
184 xfs_dir3_data_check(dp, bp);
186 * Set up values for the loop.
188 btp = xfs_dir2_block_tail_p(geo, hdr);
189 ptr = (char *)dp->d_ops->data_entry_p(hdr);
190 endptr = (char *)xfs_dir2_block_leaf_p(btp);
193 * Loop over the data portion of the block.
194 * Each object is a real entry (dep) or an unused one (dup).
196 while (ptr < endptr) {
199 dup = (xfs_dir2_data_unused_t *)ptr;
203 if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
204 ptr += be16_to_cpu(dup->length);
208 dep = (xfs_dir2_data_entry_t *)ptr;
211 * Bump pointer for the next iteration.
213 ptr += dp->d_ops->data_entsize(dep->namelen);
215 * The entry is before the desired starting point, skip it.
217 if ((char *)dep - (char *)hdr < wantoff)
220 cook = xfs_dir2_db_off_to_dataptr(geo, geo->datablk,
221 (char *)dep - (char *)hdr);
223 ctx->pos = cook & 0x7fffffff;
224 filetype = dp->d_ops->data_get_ftype(dep);
226 * If it didn't fit, set the final offset to here & return.
228 if (!dir_emit(ctx, (char *)dep->name, dep->namelen,
229 be64_to_cpu(dep->inumber),
230 xfs_dir3_get_dtype(dp->i_mount, filetype))) {
231 xfs_trans_brelse(NULL, bp);
237 * Reached the end of the block.
238 * Set the offset to a non-existent block 1 and return.
240 ctx->pos = xfs_dir2_db_off_to_dataptr(geo, geo->datablk + 1, 0) &
242 xfs_trans_brelse(NULL, bp);
246 struct xfs_dir2_leaf_map_info {
247 xfs_extlen_t map_blocks; /* number of fsbs in map */
248 xfs_dablk_t map_off; /* last mapped file offset */
249 int map_size; /* total entries in *map */
250 int map_valid; /* valid entries in *map */
251 int nmap; /* mappings to ask xfs_bmapi */
252 xfs_dir2_db_t curdb; /* db for current block */
253 int ra_current; /* number of read-ahead blks */
254 int ra_index; /* *map index for read-ahead */
255 int ra_offset; /* map entry offset for ra */
256 int ra_want; /* readahead count wanted */
257 struct xfs_bmbt_irec map[]; /* map vector for blocks */
261 xfs_dir2_leaf_readbuf(
262 struct xfs_da_args *args,
264 struct xfs_dir2_leaf_map_info *mip,
265 xfs_dir2_off_t *curoff,
266 struct xfs_buf **bpp,
269 struct xfs_inode *dp = args->dp;
270 struct xfs_buf *bp = NULL;
271 struct xfs_bmbt_irec *map = mip->map;
272 struct blk_plug plug;
277 struct xfs_da_geometry *geo = args->geo;
280 * If the caller just finished processing a buffer, it will tell us
281 * we need to trim that block out of the mapping now it is done.
284 mip->map_blocks -= geo->fsbcount;
286 * Loop to get rid of the extents for the
289 for (i = geo->fsbcount; i > 0; ) {
290 j = min_t(int, map->br_blockcount, i);
291 map->br_blockcount -= j;
292 map->br_startblock += j;
293 map->br_startoff += j;
295 * If mapping is done, pitch it from
298 if (!map->br_blockcount && --mip->map_valid)
299 memmove(&map[0], &map[1],
300 sizeof(map[0]) * mip->map_valid);
306 * Recalculate the readahead blocks wanted.
308 mip->ra_want = howmany(bufsize + geo->blksize, (1 << geo->fsblog)) - 1;
309 ASSERT(mip->ra_want >= 0);
312 * If we don't have as many as we want, and we haven't
313 * run out of data blocks, get some more mappings.
315 if (1 + mip->ra_want > mip->map_blocks &&
316 mip->map_off < xfs_dir2_byte_to_da(geo, XFS_DIR2_LEAF_OFFSET)) {
318 * Get more bmaps, fill in after the ones
319 * we already have in the table.
321 mip->nmap = mip->map_size - mip->map_valid;
322 error = xfs_bmapi_read(dp, mip->map_off,
323 xfs_dir2_byte_to_da(geo, XFS_DIR2_LEAF_OFFSET) -
325 &map[mip->map_valid], &mip->nmap, 0);
328 * Don't know if we should ignore this or try to return an
329 * error. The trouble with returning errors is that readdir
330 * will just stop without actually passing the error through.
336 * If we got all the mappings we asked for, set the final map
337 * offset based on the last bmap value received. Otherwise,
338 * we've reached the end.
340 if (mip->nmap == mip->map_size - mip->map_valid) {
341 i = mip->map_valid + mip->nmap - 1;
342 mip->map_off = map[i].br_startoff + map[i].br_blockcount;
344 mip->map_off = xfs_dir2_byte_to_da(geo,
345 XFS_DIR2_LEAF_OFFSET);
348 * Look for holes in the mapping, and eliminate them. Count up
351 for (i = mip->map_valid; i < mip->map_valid + mip->nmap; ) {
352 if (map[i].br_startblock == HOLESTARTBLOCK) {
354 length = mip->map_valid + mip->nmap - i;
356 memmove(&map[i], &map[i + 1],
357 sizeof(map[i]) * length);
359 mip->map_blocks += map[i].br_blockcount;
363 mip->map_valid += mip->nmap;
367 * No valid mappings, so no more data blocks.
369 if (!mip->map_valid) {
370 *curoff = xfs_dir2_da_to_byte(geo, mip->map_off);
375 * Read the directory block starting at the first mapping.
377 mip->curdb = xfs_dir2_da_to_db(geo, map->br_startoff);
378 error = xfs_dir3_data_read(NULL, dp, map->br_startoff,
379 map->br_blockcount >= geo->fsbcount ?
380 XFS_FSB_TO_DADDR(dp->i_mount, map->br_startblock) :
383 * Should just skip over the data block instead of giving up.
389 * Adjust the current amount of read-ahead: we just read a block that
393 mip->ra_current -= geo->fsbcount;
396 * Do we need more readahead?
398 blk_start_plug(&plug);
399 for (mip->ra_index = mip->ra_offset = i = 0;
400 mip->ra_want > mip->ra_current && i < mip->map_blocks;
401 i += geo->fsbcount) {
402 ASSERT(mip->ra_index < mip->map_valid);
404 * Read-ahead a contiguous directory block.
406 if (i > mip->ra_current &&
407 map[mip->ra_index].br_blockcount >= geo->fsbcount) {
408 xfs_dir3_data_readahead(dp,
409 map[mip->ra_index].br_startoff + mip->ra_offset,
410 XFS_FSB_TO_DADDR(dp->i_mount,
411 map[mip->ra_index].br_startblock +
417 * Read-ahead a non-contiguous directory block. This doesn't
418 * use our mapping, but this is a very rare case.
420 else if (i > mip->ra_current) {
421 xfs_dir3_data_readahead(dp,
422 map[mip->ra_index].br_startoff +
428 * Advance offset through the mapping table.
430 for (j = 0; j < geo->fsbcount; j += length ) {
432 * The rest of this extent but not more than a dir
435 length = min_t(int, geo->fsbcount,
436 map[mip->ra_index].br_blockcount -
438 mip->ra_offset += length;
441 * Advance to the next mapping if this one is used up.
443 if (mip->ra_offset == map[mip->ra_index].br_blockcount) {
449 blk_finish_plug(&plug);
457 * Getdents (readdir) for leaf and node directories.
458 * This reads the data blocks only, so is the same for both forms.
461 xfs_dir2_leaf_getdents(
462 struct xfs_da_args *args,
463 struct dir_context *ctx,
466 struct xfs_inode *dp = args->dp;
467 struct xfs_buf *bp = NULL; /* data block buffer */
468 xfs_dir2_data_hdr_t *hdr; /* data block header */
469 xfs_dir2_data_entry_t *dep; /* data entry */
470 xfs_dir2_data_unused_t *dup; /* unused entry */
471 int error = 0; /* error return value */
472 int length; /* temporary length value */
473 int byteoff; /* offset in current block */
474 xfs_dir2_off_t curoff; /* current overall offset */
475 xfs_dir2_off_t newoff; /* new curoff after new blk */
476 char *ptr = NULL; /* pointer to current data */
477 struct xfs_dir2_leaf_map_info *map_info;
478 struct xfs_da_geometry *geo = args->geo;
481 * If the offset is at or past the largest allowed value,
482 * give up right away.
484 if (ctx->pos >= XFS_DIR2_MAX_DATAPTR)
488 * Set up to bmap a number of blocks based on the caller's
489 * buffer size, the directory block size, and the filesystem
492 length = howmany(bufsize + geo->blksize, (1 << geo->fsblog));
493 map_info = kmem_zalloc(offsetof(struct xfs_dir2_leaf_map_info, map) +
494 (length * sizeof(struct xfs_bmbt_irec)),
496 map_info->map_size = length;
499 * Inside the loop we keep the main offset value as a byte offset
500 * in the directory file.
502 curoff = xfs_dir2_dataptr_to_byte(ctx->pos);
505 * Force this conversion through db so we truncate the offset
506 * down to get the start of the data block.
508 map_info->map_off = xfs_dir2_db_to_da(geo,
509 xfs_dir2_byte_to_db(geo, curoff));
512 * Loop over directory entries until we reach the end offset.
513 * Get more blocks and readahead as necessary.
515 while (curoff < XFS_DIR2_LEAF_OFFSET) {
519 * If we have no buffer, or we're off the end of the
520 * current buffer, need to get another one.
522 if (!bp || ptr >= (char *)bp->b_addr + geo->blksize) {
524 bool trim_map = false;
527 xfs_trans_brelse(NULL, bp);
532 lock_mode = xfs_ilock_data_map_shared(dp);
533 error = xfs_dir2_leaf_readbuf(args, bufsize, map_info,
534 &curoff, &bp, trim_map);
535 xfs_iunlock(dp, lock_mode);
536 if (error || !map_info->map_valid)
540 * Having done a read, we need to set a new offset.
542 newoff = xfs_dir2_db_off_to_byte(geo,
545 * Start of the current block.
550 * Make sure we're in the right block.
552 else if (curoff > newoff)
553 ASSERT(xfs_dir2_byte_to_db(geo, curoff) ==
556 xfs_dir3_data_check(dp, bp);
558 * Find our position in the block.
560 ptr = (char *)dp->d_ops->data_entry_p(hdr);
561 byteoff = xfs_dir2_byte_to_off(geo, curoff);
563 * Skip past the header.
566 curoff += dp->d_ops->data_entry_offset;
568 * Skip past entries until we reach our offset.
571 while ((char *)ptr - (char *)hdr < byteoff) {
572 dup = (xfs_dir2_data_unused_t *)ptr;
574 if (be16_to_cpu(dup->freetag)
575 == XFS_DIR2_DATA_FREE_TAG) {
577 length = be16_to_cpu(dup->length);
581 dep = (xfs_dir2_data_entry_t *)ptr;
583 dp->d_ops->data_entsize(dep->namelen);
587 * Now set our real offset.
590 xfs_dir2_db_off_to_byte(geo,
591 xfs_dir2_byte_to_db(geo, curoff),
592 (char *)ptr - (char *)hdr);
593 if (ptr >= (char *)hdr + geo->blksize) {
599 * We have a pointer to an entry.
602 dup = (xfs_dir2_data_unused_t *)ptr;
604 * No, it's unused, skip over it.
606 if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
607 length = be16_to_cpu(dup->length);
613 dep = (xfs_dir2_data_entry_t *)ptr;
614 length = dp->d_ops->data_entsize(dep->namelen);
615 filetype = dp->d_ops->data_get_ftype(dep);
617 ctx->pos = xfs_dir2_byte_to_dataptr(curoff) & 0x7fffffff;
618 if (!dir_emit(ctx, (char *)dep->name, dep->namelen,
619 be64_to_cpu(dep->inumber),
620 xfs_dir3_get_dtype(dp->i_mount, filetype)))
624 * Advance to next entry in the block.
628 /* bufsize may have just been a guess; don't go negative */
629 bufsize = bufsize > length ? bufsize - length : 0;
633 * All done. Set output offset value to current offset.
635 if (curoff > xfs_dir2_dataptr_to_byte(XFS_DIR2_MAX_DATAPTR))
636 ctx->pos = XFS_DIR2_MAX_DATAPTR & 0x7fffffff;
638 ctx->pos = xfs_dir2_byte_to_dataptr(curoff) & 0x7fffffff;
641 xfs_trans_brelse(NULL, bp);
650 struct xfs_inode *dp,
651 struct dir_context *ctx,
654 struct xfs_da_args args = { NULL };
658 trace_xfs_readdir(dp);
660 if (XFS_FORCED_SHUTDOWN(dp->i_mount))
663 ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
664 XFS_STATS_INC(dp->i_mount, xs_dir_getdents);
667 args.geo = dp->i_mount->m_dir_geo;
669 if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
670 rval = xfs_dir2_sf_getdents(&args, ctx);
671 else if ((rval = xfs_dir2_isblock(&args, &v)))
674 rval = xfs_dir2_block_getdents(&args, ctx);
676 rval = xfs_dir2_leaf_getdents(&args, ctx, bufsize);