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"
27 #include "xfs_mount.h"
28 #include "xfs_da_format.h"
29 #include "xfs_da_btree.h"
30 #include "xfs_inode.h"
32 #include "xfs_dir2_priv.h"
33 #include "xfs_error.h"
34 #include "xfs_trace.h"
36 #include "xfs_trans.h"
37 #include "xfs_dinode.h"
40 * Directory file type support functions
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
,
52 if (!xfs_sb_version_hasftype(&mp
->m_sb
))
55 if (filetype
>= XFS_DIR3_FT_MAX
)
58 return xfs_dir3_filetype_table
[filetype
];
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.
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
,
79 xfs_inode_t
*dp
, /* incore directory inode */
80 struct dir_context
*ctx
)
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
;
90 struct xfs_da_geometry
*geo
;
95 ASSERT(dp
->i_df
.if_flags
& XFS_IFINLINE
);
97 * Give up if the directory is way too short.
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
);
104 ASSERT(dp
->i_df
.if_bytes
== dp
->i_d
.di_size
);
105 ASSERT(dp
->i_df
.if_u1
.if_data
!= NULL
);
107 sfp
= (xfs_dir2_sf_hdr_t
*)dp
->i_df
.if_u1
.if_data
;
109 ASSERT(dp
->i_d
.di_size
>= xfs_dir2_sf_hdr_size(sfp
->i8count
));
112 * If the block number in the offset is out of range, we're done.
114 if (xfs_dir2_dataptr_to_db(geo
, ctx
->pos
) > geo
->datablk
)
118 * Precalculate offsets for . and .. as we will always need them.
120 * XXX(hch): the second argument is sometimes 0 and sometimes
123 dot_offset
= xfs_dir2_db_off_to_dataptr(geo
, geo
->datablk
,
124 dp
->d_ops
->data_dot_offset
);
125 dotdot_offset
= xfs_dir2_db_off_to_dataptr(geo
, geo
->datablk
,
126 dp
->d_ops
->data_dotdot_offset
);
129 * Put . entry unless we're starting past it.
131 if (ctx
->pos
<= dot_offset
) {
132 ctx
->pos
= dot_offset
& 0x7fffffff;
133 if (!dir_emit(ctx
, ".", 1, dp
->i_ino
, DT_DIR
))
138 * Put .. entry unless we're starting past it.
140 if (ctx
->pos
<= dotdot_offset
) {
141 ino
= dp
->d_ops
->sf_get_parent_ino(sfp
);
142 ctx
->pos
= dotdot_offset
& 0x7fffffff;
143 if (!dir_emit(ctx
, "..", 2, ino
, DT_DIR
))
148 * Loop while there are more entries and put'ing works.
150 sfep
= xfs_dir2_sf_firstentry(sfp
);
151 for (i
= 0; i
< sfp
->count
; i
++) {
154 off
= xfs_dir2_db_off_to_dataptr(geo
, geo
->datablk
,
155 xfs_dir2_sf_get_offset(sfep
));
157 if (ctx
->pos
> off
) {
158 sfep
= dp
->d_ops
->sf_nextentry(sfp
, sfep
);
162 ino
= dp
->d_ops
->sf_get_ino(sfp
, sfep
);
163 filetype
= dp
->d_ops
->sf_get_ftype(sfep
);
164 ctx
->pos
= off
& 0x7fffffff;
165 if (!dir_emit(ctx
, (char *)sfep
->name
, sfep
->namelen
, ino
,
166 xfs_dir3_get_dtype(mp
, filetype
)))
168 sfep
= dp
->d_ops
->sf_nextentry(sfp
, sfep
);
171 ctx
->pos
= xfs_dir2_db_off_to_dataptr(geo
, geo
->datablk
+ 1, 0) &
177 * Readdir for block directories.
180 xfs_dir2_block_getdents(
181 xfs_inode_t
*dp
, /* incore inode */
182 struct dir_context
*ctx
)
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 */
195 struct xfs_da_geometry
*geo
;
200 * If the block number in the offset is out of range, we're done.
202 if (xfs_dir2_dataptr_to_db(geo
, ctx
->pos
) > geo
->datablk
)
205 error
= xfs_dir3_block_read(NULL
, dp
, &bp
);
210 * Extract the byte offset we start at from the seek pointer.
211 * We'll skip entries before this.
213 wantoff
= xfs_dir2_dataptr_to_off(geo
, ctx
->pos
);
215 xfs_dir3_data_check(dp
, bp
);
217 * Set up values for the loop.
219 btp
= xfs_dir2_block_tail_p(geo
, hdr
);
220 ptr
= (char *)dp
->d_ops
->data_entry_p(hdr
);
221 endptr
= (char *)xfs_dir2_block_leaf_p(btp
);
224 * Loop over the data portion of the block.
225 * Each object is a real entry (dep) or an unused one (dup).
227 while (ptr
< endptr
) {
230 dup
= (xfs_dir2_data_unused_t
*)ptr
;
234 if (be16_to_cpu(dup
->freetag
) == XFS_DIR2_DATA_FREE_TAG
) {
235 ptr
+= be16_to_cpu(dup
->length
);
239 dep
= (xfs_dir2_data_entry_t
*)ptr
;
242 * Bump pointer for the next iteration.
244 ptr
+= dp
->d_ops
->data_entsize(dep
->namelen
);
246 * The entry is before the desired starting point, skip it.
248 if ((char *)dep
- (char *)hdr
< wantoff
)
251 cook
= xfs_dir2_db_off_to_dataptr(geo
, geo
->datablk
,
252 (char *)dep
- (char *)hdr
);
254 ctx
->pos
= cook
& 0x7fffffff;
255 filetype
= dp
->d_ops
->data_get_ftype(dep
);
257 * If it didn't fit, set the final offset to here & return.
259 if (!dir_emit(ctx
, (char *)dep
->name
, dep
->namelen
,
260 be64_to_cpu(dep
->inumber
),
261 xfs_dir3_get_dtype(mp
, filetype
))) {
262 xfs_trans_brelse(NULL
, bp
);
268 * Reached the end of the block.
269 * Set the offset to a non-existent block 1 and return.
271 ctx
->pos
= xfs_dir2_db_off_to_dataptr(geo
, geo
->datablk
+ 1, 0) &
273 xfs_trans_brelse(NULL
, bp
);
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 */
292 xfs_dir2_leaf_readbuf(
293 struct xfs_inode
*dp
,
295 struct xfs_dir2_leaf_map_info
*mip
,
296 xfs_dir2_off_t
*curoff
,
297 struct xfs_buf
**bpp
)
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
;
307 struct xfs_da_geometry
*geo
= mp
->m_dir_geo
;
310 * If we have a buffer, we need to release it and
311 * take it out of the mapping.
315 xfs_trans_brelse(NULL
, bp
);
317 mip
->map_blocks
-= geo
->fsbcount
;
319 * Loop to get rid of the extents for the
322 for (i
= geo
->fsbcount
; i
> 0; ) {
323 j
= min_t(int, map
->br_blockcount
, i
);
324 map
->br_blockcount
-= j
;
325 map
->br_startblock
+= j
;
326 map
->br_startoff
+= j
;
328 * If mapping is done, pitch it from
331 if (!map
->br_blockcount
&& --mip
->map_valid
)
332 memmove(&map
[0], &map
[1],
333 sizeof(map
[0]) * mip
->map_valid
);
339 * Recalculate the readahead blocks wanted.
341 mip
->ra_want
= howmany(bufsize
+ geo
->blksize
,
342 mp
->m_sb
.sb_blocksize
) - 1;
343 ASSERT(mip
->ra_want
>= 0);
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.
349 if (1 + mip
->ra_want
> mip
->map_blocks
&&
350 mip
->map_off
< xfs_dir2_byte_to_da(geo
, XFS_DIR2_LEAF_OFFSET
)) {
352 * Get more bmaps, fill in after the ones
353 * we already have in the table.
355 mip
->nmap
= mip
->map_size
- mip
->map_valid
;
356 error
= xfs_bmapi_read(dp
, mip
->map_off
,
357 xfs_dir2_byte_to_da(geo
, XFS_DIR2_LEAF_OFFSET
) -
359 &map
[mip
->map_valid
], &mip
->nmap
, 0);
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.
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.
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
;
378 mip
->map_off
= xfs_dir2_byte_to_da(geo
,
379 XFS_DIR2_LEAF_OFFSET
);
382 * Look for holes in the mapping, and eliminate them. Count up
385 for (i
= mip
->map_valid
; i
< mip
->map_valid
+ mip
->nmap
; ) {
386 if (map
[i
].br_startblock
== HOLESTARTBLOCK
) {
388 length
= mip
->map_valid
+ mip
->nmap
- i
;
390 memmove(&map
[i
], &map
[i
+ 1],
391 sizeof(map
[i
]) * length
);
393 mip
->map_blocks
+= map
[i
].br_blockcount
;
397 mip
->map_valid
+= mip
->nmap
;
401 * No valid mappings, so no more data blocks.
403 if (!mip
->map_valid
) {
404 *curoff
= xfs_dir2_da_to_byte(geo
, mip
->map_off
);
409 * Read the directory block starting at the first mapping.
411 mip
->curdb
= xfs_dir2_da_to_db(geo
, map
->br_startoff
);
412 error
= xfs_dir3_data_read(NULL
, dp
, map
->br_startoff
,
413 map
->br_blockcount
>= geo
->fsbcount
?
414 XFS_FSB_TO_DADDR(mp
, map
->br_startblock
) : -1, &bp
);
417 * Should just skip over the data block instead of giving up.
423 * Adjust the current amount of read-ahead: we just read a block that
427 mip
->ra_current
-= geo
->fsbcount
;
430 * Do we need more readahead?
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
;
435 i
+= geo
->fsbcount
) {
436 ASSERT(mip
->ra_index
< mip
->map_valid
);
438 * Read-ahead a contiguous directory block.
440 if (i
> mip
->ra_current
&&
441 map
[mip
->ra_index
].br_blockcount
>= geo
->fsbcount
) {
442 xfs_dir3_data_readahead(dp
,
443 map
[mip
->ra_index
].br_startoff
+ mip
->ra_offset
,
445 map
[mip
->ra_index
].br_startblock
+
451 * Read-ahead a non-contiguous directory block. This doesn't
452 * use our mapping, but this is a very rare case.
454 else if (i
> mip
->ra_current
) {
455 xfs_dir3_data_readahead(dp
,
456 map
[mip
->ra_index
].br_startoff
+
462 * Advance offset through the mapping table.
464 for (j
= 0; j
< geo
->fsbcount
; j
+= length
) {
466 * The rest of this extent but not more than a dir
469 length
= min_t(int, geo
->fsbcount
,
470 map
[mip
->ra_index
].br_blockcount
-
472 mip
->ra_offset
+= length
;
475 * Advance to the next mapping if this one is used up.
477 if (mip
->ra_offset
== map
[mip
->ra_index
].br_blockcount
) {
483 blk_finish_plug(&plug
);
491 * Getdents (readdir) for leaf and node directories.
492 * This reads the data blocks only, so is the same for both forms.
495 xfs_dir2_leaf_getdents(
496 xfs_inode_t
*dp
, /* incore directory inode */
497 struct dir_context
*ctx
,
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
;
512 struct xfs_da_geometry
*geo
;
515 * If the offset is at or past the largest allowed value,
516 * give up right away.
518 if (ctx
->pos
>= XFS_DIR2_MAX_DATAPTR
)
525 * Set up to bmap a number of blocks based on the caller's
526 * buffer size, the directory block size, and the filesystem
529 length
= howmany(bufsize
+ geo
->blksize
, mp
->m_sb
.sb_blocksize
);
530 map_info
= kmem_zalloc(offsetof(struct xfs_dir2_leaf_map_info
, map
) +
531 (length
* sizeof(struct xfs_bmbt_irec
)),
533 map_info
->map_size
= length
;
536 * Inside the loop we keep the main offset value as a byte offset
537 * in the directory file.
539 curoff
= xfs_dir2_dataptr_to_byte(ctx
->pos
);
542 * Force this conversion through db so we truncate the offset
543 * down to get the start of the data block.
545 map_info
->map_off
= xfs_dir2_db_to_da(geo
,
546 xfs_dir2_byte_to_db(geo
, curoff
));
549 * Loop over directory entries until we reach the end offset.
550 * Get more blocks and readahead as necessary.
552 while (curoff
< XFS_DIR2_LEAF_OFFSET
) {
556 * If we have no buffer, or we're off the end of the
557 * current buffer, need to get another one.
559 if (!bp
|| ptr
>= (char *)bp
->b_addr
+ geo
->blksize
) {
561 error
= xfs_dir2_leaf_readbuf(dp
, bufsize
, map_info
,
563 if (error
|| !map_info
->map_valid
)
567 * Having done a read, we need to set a new offset.
569 newoff
= xfs_dir2_db_off_to_byte(mp
->m_dir_geo
,
572 * Start of the current block.
577 * Make sure we're in the right block.
579 else if (curoff
> newoff
)
580 ASSERT(xfs_dir2_byte_to_db(geo
, curoff
) ==
583 xfs_dir3_data_check(dp
, bp
);
585 * Find our position in the block.
587 ptr
= (char *)dp
->d_ops
->data_entry_p(hdr
);
588 byteoff
= xfs_dir2_byte_to_off(mp
->m_dir_geo
, curoff
);
590 * Skip past the header.
593 curoff
+= dp
->d_ops
->data_entry_offset
;
595 * Skip past entries until we reach our offset.
598 while ((char *)ptr
- (char *)hdr
< byteoff
) {
599 dup
= (xfs_dir2_data_unused_t
*)ptr
;
601 if (be16_to_cpu(dup
->freetag
)
602 == XFS_DIR2_DATA_FREE_TAG
) {
604 length
= be16_to_cpu(dup
->length
);
608 dep
= (xfs_dir2_data_entry_t
*)ptr
;
610 dp
->d_ops
->data_entsize(dep
->namelen
);
614 * Now set our real offset.
617 xfs_dir2_db_off_to_byte(geo
,
618 xfs_dir2_byte_to_db(geo
, curoff
),
619 (char *)ptr
- (char *)hdr
);
620 if (ptr
>= (char *)hdr
+ geo
->blksize
) {
626 * We have a pointer to an entry.
629 dup
= (xfs_dir2_data_unused_t
*)ptr
;
631 * No, it's unused, skip over it.
633 if (be16_to_cpu(dup
->freetag
) == XFS_DIR2_DATA_FREE_TAG
) {
634 length
= be16_to_cpu(dup
->length
);
640 dep
= (xfs_dir2_data_entry_t
*)ptr
;
641 length
= dp
->d_ops
->data_entsize(dep
->namelen
);
642 filetype
= dp
->d_ops
->data_get_ftype(dep
);
644 ctx
->pos
= xfs_dir2_byte_to_dataptr(curoff
) & 0x7fffffff;
645 if (!dir_emit(ctx
, (char *)dep
->name
, dep
->namelen
,
646 be64_to_cpu(dep
->inumber
),
647 xfs_dir3_get_dtype(mp
, filetype
)))
651 * Advance to next entry in the block.
655 /* bufsize may have just been a guess; don't go negative */
656 bufsize
= bufsize
> length
? bufsize
- length
: 0;
660 * All done. Set output offset value to current offset.
662 if (curoff
> xfs_dir2_dataptr_to_byte(XFS_DIR2_MAX_DATAPTR
))
663 ctx
->pos
= XFS_DIR2_MAX_DATAPTR
& 0x7fffffff;
665 ctx
->pos
= xfs_dir2_byte_to_dataptr(curoff
) & 0x7fffffff;
668 xfs_trans_brelse(NULL
, bp
);
678 struct dir_context
*ctx
,
681 int rval
; /* return value */
682 int v
; /* type-checking value */
685 trace_xfs_readdir(dp
);
687 if (XFS_FORCED_SHUTDOWN(dp
->i_mount
))
688 return XFS_ERROR(EIO
);
690 ASSERT(S_ISDIR(dp
->i_d
.di_mode
));
691 XFS_STATS_INC(xs_dir_getdents
);
693 lock_mode
= xfs_ilock_data_map_shared(dp
);
694 if (dp
->i_d
.di_format
== XFS_DINODE_FMT_LOCAL
)
695 rval
= xfs_dir2_sf_getdents(dp
, ctx
);
696 else if ((rval
= xfs_dir2_isblock(dp
, &v
)))
699 rval
= xfs_dir2_block_getdents(dp
, ctx
);
701 rval
= xfs_dir2_leaf_getdents(dp
, ctx
, bufsize
);
702 xfs_iunlock(dp
, lock_mode
);