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
);
75 * Give up if the directory is way too short.
77 if (dp
->i_d
.di_size
< offsetof(xfs_dir2_sf_hdr_t
, parent
)) {
78 ASSERT(XFS_FORCED_SHUTDOWN(dp
->i_mount
));
82 ASSERT(dp
->i_df
.if_bytes
== dp
->i_d
.di_size
);
83 ASSERT(dp
->i_df
.if_u1
.if_data
!= NULL
);
85 sfp
= (xfs_dir2_sf_hdr_t
*)dp
->i_df
.if_u1
.if_data
;
87 ASSERT(dp
->i_d
.di_size
>= xfs_dir2_sf_hdr_size(sfp
->i8count
));
90 * If the block number in the offset is out of range, we're done.
92 if (xfs_dir2_dataptr_to_db(geo
, ctx
->pos
) > geo
->datablk
)
96 * Precalculate offsets for . and .. as we will always need them.
98 * XXX(hch): the second argument is sometimes 0 and sometimes
101 dot_offset
= xfs_dir2_db_off_to_dataptr(geo
, geo
->datablk
,
102 dp
->d_ops
->data_dot_offset
);
103 dotdot_offset
= xfs_dir2_db_off_to_dataptr(geo
, geo
->datablk
,
104 dp
->d_ops
->data_dotdot_offset
);
107 * Put . entry unless we're starting past it.
109 if (ctx
->pos
<= dot_offset
) {
110 ctx
->pos
= dot_offset
& 0x7fffffff;
111 if (!dir_emit(ctx
, ".", 1, dp
->i_ino
, DT_DIR
))
116 * Put .. entry unless we're starting past it.
118 if (ctx
->pos
<= dotdot_offset
) {
119 ino
= dp
->d_ops
->sf_get_parent_ino(sfp
);
120 ctx
->pos
= dotdot_offset
& 0x7fffffff;
121 if (!dir_emit(ctx
, "..", 2, ino
, DT_DIR
))
126 * Loop while there are more entries and put'ing works.
128 sfep
= xfs_dir2_sf_firstentry(sfp
);
129 for (i
= 0; i
< sfp
->count
; i
++) {
132 off
= xfs_dir2_db_off_to_dataptr(geo
, geo
->datablk
,
133 xfs_dir2_sf_get_offset(sfep
));
135 if (ctx
->pos
> off
) {
136 sfep
= dp
->d_ops
->sf_nextentry(sfp
, sfep
);
140 ino
= dp
->d_ops
->sf_get_ino(sfp
, sfep
);
141 filetype
= dp
->d_ops
->sf_get_ftype(sfep
);
142 ctx
->pos
= off
& 0x7fffffff;
143 if (!dir_emit(ctx
, (char *)sfep
->name
, sfep
->namelen
, ino
,
144 xfs_dir3_get_dtype(dp
->i_mount
, filetype
)))
146 sfep
= dp
->d_ops
->sf_nextentry(sfp
, sfep
);
149 ctx
->pos
= xfs_dir2_db_off_to_dataptr(geo
, geo
->datablk
+ 1, 0) &
155 * Readdir for block directories.
158 xfs_dir2_block_getdents(
159 struct xfs_da_args
*args
,
160 struct dir_context
*ctx
)
162 struct xfs_inode
*dp
= args
->dp
; /* incore directory inode */
163 xfs_dir2_data_hdr_t
*hdr
; /* block header */
164 struct xfs_buf
*bp
; /* buffer for block */
165 xfs_dir2_block_tail_t
*btp
; /* block tail */
166 xfs_dir2_data_entry_t
*dep
; /* block data entry */
167 xfs_dir2_data_unused_t
*dup
; /* block unused entry */
168 char *endptr
; /* end of the data entries */
169 int error
; /* error return value */
170 char *ptr
; /* current data entry */
171 int wantoff
; /* starting block offset */
173 struct xfs_da_geometry
*geo
= args
->geo
;
176 * If the block number in the offset is out of range, we're done.
178 if (xfs_dir2_dataptr_to_db(geo
, ctx
->pos
) > geo
->datablk
)
181 error
= xfs_dir3_block_read(NULL
, dp
, &bp
);
186 * Extract the byte offset we start at from the seek pointer.
187 * We'll skip entries before this.
189 wantoff
= xfs_dir2_dataptr_to_off(geo
, ctx
->pos
);
191 xfs_dir3_data_check(dp
, bp
);
193 * Set up values for the loop.
195 btp
= xfs_dir2_block_tail_p(geo
, hdr
);
196 ptr
= (char *)dp
->d_ops
->data_entry_p(hdr
);
197 endptr
= (char *)xfs_dir2_block_leaf_p(btp
);
200 * Loop over the data portion of the block.
201 * Each object is a real entry (dep) or an unused one (dup).
203 while (ptr
< endptr
) {
206 dup
= (xfs_dir2_data_unused_t
*)ptr
;
210 if (be16_to_cpu(dup
->freetag
) == XFS_DIR2_DATA_FREE_TAG
) {
211 ptr
+= be16_to_cpu(dup
->length
);
215 dep
= (xfs_dir2_data_entry_t
*)ptr
;
218 * Bump pointer for the next iteration.
220 ptr
+= dp
->d_ops
->data_entsize(dep
->namelen
);
222 * The entry is before the desired starting point, skip it.
224 if ((char *)dep
- (char *)hdr
< wantoff
)
227 cook
= xfs_dir2_db_off_to_dataptr(geo
, geo
->datablk
,
228 (char *)dep
- (char *)hdr
);
230 ctx
->pos
= cook
& 0x7fffffff;
231 filetype
= dp
->d_ops
->data_get_ftype(dep
);
233 * If it didn't fit, set the final offset to here & return.
235 if (!dir_emit(ctx
, (char *)dep
->name
, dep
->namelen
,
236 be64_to_cpu(dep
->inumber
),
237 xfs_dir3_get_dtype(dp
->i_mount
, filetype
))) {
238 xfs_trans_brelse(NULL
, bp
);
244 * Reached the end of the block.
245 * Set the offset to a non-existent block 1 and return.
247 ctx
->pos
= xfs_dir2_db_off_to_dataptr(geo
, geo
->datablk
+ 1, 0) &
249 xfs_trans_brelse(NULL
, bp
);
253 struct xfs_dir2_leaf_map_info
{
254 xfs_extlen_t map_blocks
; /* number of fsbs in map */
255 xfs_dablk_t map_off
; /* last mapped file offset */
256 int map_size
; /* total entries in *map */
257 int map_valid
; /* valid entries in *map */
258 int nmap
; /* mappings to ask xfs_bmapi */
259 xfs_dir2_db_t curdb
; /* db for current block */
260 int ra_current
; /* number of read-ahead blks */
261 int ra_index
; /* *map index for read-ahead */
262 int ra_offset
; /* map entry offset for ra */
263 int ra_want
; /* readahead count wanted */
264 struct xfs_bmbt_irec map
[]; /* map vector for blocks */
268 xfs_dir2_leaf_readbuf(
269 struct xfs_da_args
*args
,
271 struct xfs_dir2_leaf_map_info
*mip
,
272 xfs_dir2_off_t
*curoff
,
273 struct xfs_buf
**bpp
)
275 struct xfs_inode
*dp
= args
->dp
;
276 struct xfs_buf
*bp
= *bpp
;
277 struct xfs_bmbt_irec
*map
= mip
->map
;
278 struct blk_plug plug
;
283 struct xfs_da_geometry
*geo
= args
->geo
;
286 * If we have a buffer, we need to release it and
287 * take it out of the mapping.
291 xfs_trans_brelse(NULL
, bp
);
293 mip
->map_blocks
-= geo
->fsbcount
;
295 * Loop to get rid of the extents for the
298 for (i
= geo
->fsbcount
; i
> 0; ) {
299 j
= min_t(int, map
->br_blockcount
, i
);
300 map
->br_blockcount
-= j
;
301 map
->br_startblock
+= j
;
302 map
->br_startoff
+= j
;
304 * If mapping is done, pitch it from
307 if (!map
->br_blockcount
&& --mip
->map_valid
)
308 memmove(&map
[0], &map
[1],
309 sizeof(map
[0]) * mip
->map_valid
);
315 * Recalculate the readahead blocks wanted.
317 mip
->ra_want
= howmany(bufsize
+ geo
->blksize
, (1 << geo
->fsblog
)) - 1;
318 ASSERT(mip
->ra_want
>= 0);
321 * If we don't have as many as we want, and we haven't
322 * run out of data blocks, get some more mappings.
324 if (1 + mip
->ra_want
> mip
->map_blocks
&&
325 mip
->map_off
< xfs_dir2_byte_to_da(geo
, XFS_DIR2_LEAF_OFFSET
)) {
327 * Get more bmaps, fill in after the ones
328 * we already have in the table.
330 mip
->nmap
= mip
->map_size
- mip
->map_valid
;
331 error
= xfs_bmapi_read(dp
, mip
->map_off
,
332 xfs_dir2_byte_to_da(geo
, XFS_DIR2_LEAF_OFFSET
) -
334 &map
[mip
->map_valid
], &mip
->nmap
, 0);
337 * Don't know if we should ignore this or try to return an
338 * error. The trouble with returning errors is that readdir
339 * will just stop without actually passing the error through.
345 * If we got all the mappings we asked for, set the final map
346 * offset based on the last bmap value received. Otherwise,
347 * we've reached the end.
349 if (mip
->nmap
== mip
->map_size
- mip
->map_valid
) {
350 i
= mip
->map_valid
+ mip
->nmap
- 1;
351 mip
->map_off
= map
[i
].br_startoff
+ map
[i
].br_blockcount
;
353 mip
->map_off
= xfs_dir2_byte_to_da(geo
,
354 XFS_DIR2_LEAF_OFFSET
);
357 * Look for holes in the mapping, and eliminate them. Count up
360 for (i
= mip
->map_valid
; i
< mip
->map_valid
+ mip
->nmap
; ) {
361 if (map
[i
].br_startblock
== HOLESTARTBLOCK
) {
363 length
= mip
->map_valid
+ mip
->nmap
- i
;
365 memmove(&map
[i
], &map
[i
+ 1],
366 sizeof(map
[i
]) * length
);
368 mip
->map_blocks
+= map
[i
].br_blockcount
;
372 mip
->map_valid
+= mip
->nmap
;
376 * No valid mappings, so no more data blocks.
378 if (!mip
->map_valid
) {
379 *curoff
= xfs_dir2_da_to_byte(geo
, mip
->map_off
);
384 * Read the directory block starting at the first mapping.
386 mip
->curdb
= xfs_dir2_da_to_db(geo
, map
->br_startoff
);
387 error
= xfs_dir3_data_read(NULL
, dp
, map
->br_startoff
,
388 map
->br_blockcount
>= geo
->fsbcount
?
389 XFS_FSB_TO_DADDR(dp
->i_mount
, map
->br_startblock
) :
392 * Should just skip over the data block instead of giving up.
398 * Adjust the current amount of read-ahead: we just read a block that
402 mip
->ra_current
-= geo
->fsbcount
;
405 * Do we need more readahead?
407 blk_start_plug(&plug
);
408 for (mip
->ra_index
= mip
->ra_offset
= i
= 0;
409 mip
->ra_want
> mip
->ra_current
&& i
< mip
->map_blocks
;
410 i
+= geo
->fsbcount
) {
411 ASSERT(mip
->ra_index
< mip
->map_valid
);
413 * Read-ahead a contiguous directory block.
415 if (i
> mip
->ra_current
&&
416 map
[mip
->ra_index
].br_blockcount
>= geo
->fsbcount
) {
417 xfs_dir3_data_readahead(dp
,
418 map
[mip
->ra_index
].br_startoff
+ mip
->ra_offset
,
419 XFS_FSB_TO_DADDR(dp
->i_mount
,
420 map
[mip
->ra_index
].br_startblock
+
426 * Read-ahead a non-contiguous directory block. This doesn't
427 * use our mapping, but this is a very rare case.
429 else if (i
> mip
->ra_current
) {
430 xfs_dir3_data_readahead(dp
,
431 map
[mip
->ra_index
].br_startoff
+
437 * Advance offset through the mapping table.
439 for (j
= 0; j
< geo
->fsbcount
; j
+= length
) {
441 * The rest of this extent but not more than a dir
444 length
= min_t(int, geo
->fsbcount
,
445 map
[mip
->ra_index
].br_blockcount
-
447 mip
->ra_offset
+= length
;
450 * Advance to the next mapping if this one is used up.
452 if (mip
->ra_offset
== map
[mip
->ra_index
].br_blockcount
) {
458 blk_finish_plug(&plug
);
466 * Getdents (readdir) for leaf and node directories.
467 * This reads the data blocks only, so is the same for both forms.
470 xfs_dir2_leaf_getdents(
471 struct xfs_da_args
*args
,
472 struct dir_context
*ctx
,
475 struct xfs_inode
*dp
= args
->dp
;
476 struct xfs_buf
*bp
= NULL
; /* data block buffer */
477 xfs_dir2_data_hdr_t
*hdr
; /* data block header */
478 xfs_dir2_data_entry_t
*dep
; /* data entry */
479 xfs_dir2_data_unused_t
*dup
; /* unused entry */
480 int error
= 0; /* error return value */
481 int length
; /* temporary length value */
482 int byteoff
; /* offset in current block */
483 xfs_dir2_off_t curoff
; /* current overall offset */
484 xfs_dir2_off_t newoff
; /* new curoff after new blk */
485 char *ptr
= NULL
; /* pointer to current data */
486 struct xfs_dir2_leaf_map_info
*map_info
;
487 struct xfs_da_geometry
*geo
= args
->geo
;
490 * If the offset is at or past the largest allowed value,
491 * give up right away.
493 if (ctx
->pos
>= XFS_DIR2_MAX_DATAPTR
)
497 * Set up to bmap a number of blocks based on the caller's
498 * buffer size, the directory block size, and the filesystem
501 length
= howmany(bufsize
+ geo
->blksize
, (1 << geo
->fsblog
));
502 map_info
= kmem_zalloc(offsetof(struct xfs_dir2_leaf_map_info
, map
) +
503 (length
* sizeof(struct xfs_bmbt_irec
)),
505 map_info
->map_size
= length
;
508 * Inside the loop we keep the main offset value as a byte offset
509 * in the directory file.
511 curoff
= xfs_dir2_dataptr_to_byte(ctx
->pos
);
514 * Force this conversion through db so we truncate the offset
515 * down to get the start of the data block.
517 map_info
->map_off
= xfs_dir2_db_to_da(geo
,
518 xfs_dir2_byte_to_db(geo
, curoff
));
521 * Loop over directory entries until we reach the end offset.
522 * Get more blocks and readahead as necessary.
524 while (curoff
< XFS_DIR2_LEAF_OFFSET
) {
528 * If we have no buffer, or we're off the end of the
529 * current buffer, need to get another one.
531 if (!bp
|| ptr
>= (char *)bp
->b_addr
+ geo
->blksize
) {
533 error
= xfs_dir2_leaf_readbuf(args
, bufsize
, map_info
,
535 if (error
|| !map_info
->map_valid
)
539 * Having done a read, we need to set a new offset.
541 newoff
= xfs_dir2_db_off_to_byte(geo
,
544 * Start of the current block.
549 * Make sure we're in the right block.
551 else if (curoff
> newoff
)
552 ASSERT(xfs_dir2_byte_to_db(geo
, curoff
) ==
555 xfs_dir3_data_check(dp
, bp
);
557 * Find our position in the block.
559 ptr
= (char *)dp
->d_ops
->data_entry_p(hdr
);
560 byteoff
= xfs_dir2_byte_to_off(geo
, curoff
);
562 * Skip past the header.
565 curoff
+= dp
->d_ops
->data_entry_offset
;
567 * Skip past entries until we reach our offset.
570 while ((char *)ptr
- (char *)hdr
< byteoff
) {
571 dup
= (xfs_dir2_data_unused_t
*)ptr
;
573 if (be16_to_cpu(dup
->freetag
)
574 == XFS_DIR2_DATA_FREE_TAG
) {
576 length
= be16_to_cpu(dup
->length
);
580 dep
= (xfs_dir2_data_entry_t
*)ptr
;
582 dp
->d_ops
->data_entsize(dep
->namelen
);
586 * Now set our real offset.
589 xfs_dir2_db_off_to_byte(geo
,
590 xfs_dir2_byte_to_db(geo
, curoff
),
591 (char *)ptr
- (char *)hdr
);
592 if (ptr
>= (char *)hdr
+ geo
->blksize
) {
598 * We have a pointer to an entry.
601 dup
= (xfs_dir2_data_unused_t
*)ptr
;
603 * No, it's unused, skip over it.
605 if (be16_to_cpu(dup
->freetag
) == XFS_DIR2_DATA_FREE_TAG
) {
606 length
= be16_to_cpu(dup
->length
);
612 dep
= (xfs_dir2_data_entry_t
*)ptr
;
613 length
= dp
->d_ops
->data_entsize(dep
->namelen
);
614 filetype
= dp
->d_ops
->data_get_ftype(dep
);
616 ctx
->pos
= xfs_dir2_byte_to_dataptr(curoff
) & 0x7fffffff;
617 if (!dir_emit(ctx
, (char *)dep
->name
, dep
->namelen
,
618 be64_to_cpu(dep
->inumber
),
619 xfs_dir3_get_dtype(dp
->i_mount
, filetype
)))
623 * Advance to next entry in the block.
627 /* bufsize may have just been a guess; don't go negative */
628 bufsize
= bufsize
> length
? bufsize
- length
: 0;
632 * All done. Set output offset value to current offset.
634 if (curoff
> xfs_dir2_dataptr_to_byte(XFS_DIR2_MAX_DATAPTR
))
635 ctx
->pos
= XFS_DIR2_MAX_DATAPTR
& 0x7fffffff;
637 ctx
->pos
= xfs_dir2_byte_to_dataptr(curoff
) & 0x7fffffff;
640 xfs_trans_brelse(NULL
, bp
);
649 struct xfs_inode
*dp
,
650 struct dir_context
*ctx
,
653 struct xfs_da_args args
= { NULL
};
658 trace_xfs_readdir(dp
);
660 if (XFS_FORCED_SHUTDOWN(dp
->i_mount
))
663 ASSERT(S_ISDIR(dp
->i_d
.di_mode
));
664 XFS_STATS_INC(xs_dir_getdents
);
667 args
.geo
= dp
->i_mount
->m_dir_geo
;
669 lock_mode
= xfs_ilock_data_map_shared(dp
);
670 if (dp
->i_d
.di_format
== XFS_DINODE_FMT_LOCAL
)
671 rval
= xfs_dir2_sf_getdents(&args
, ctx
);
672 else if ((rval
= xfs_dir2_isblock(&args
, &v
)))
675 rval
= xfs_dir2_block_getdents(&args
, ctx
);
677 rval
= xfs_dir2_leaf_getdents(&args
, ctx
, bufsize
);
678 xfs_iunlock(dp
, lock_mode
);