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 struct xfs_da_args
*args
,
80 struct dir_context
*ctx
)
82 int i
; /* shortform entry number */
83 struct xfs_inode
*dp
= args
->dp
; /* incore directory inode */
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
= args
->geo
;
92 ASSERT(dp
->i_df
.if_flags
& XFS_IFINLINE
);
94 * Give up if the directory is way too short.
96 if (dp
->i_d
.di_size
< offsetof(xfs_dir2_sf_hdr_t
, parent
)) {
97 ASSERT(XFS_FORCED_SHUTDOWN(dp
->i_mount
));
101 ASSERT(dp
->i_df
.if_bytes
== dp
->i_d
.di_size
);
102 ASSERT(dp
->i_df
.if_u1
.if_data
!= NULL
);
104 sfp
= (xfs_dir2_sf_hdr_t
*)dp
->i_df
.if_u1
.if_data
;
106 ASSERT(dp
->i_d
.di_size
>= xfs_dir2_sf_hdr_size(sfp
->i8count
));
109 * If the block number in the offset is out of range, we're done.
111 if (xfs_dir2_dataptr_to_db(geo
, ctx
->pos
) > geo
->datablk
)
115 * Precalculate offsets for . and .. as we will always need them.
117 * XXX(hch): the second argument is sometimes 0 and sometimes
120 dot_offset
= xfs_dir2_db_off_to_dataptr(geo
, geo
->datablk
,
121 dp
->d_ops
->data_dot_offset
);
122 dotdot_offset
= xfs_dir2_db_off_to_dataptr(geo
, geo
->datablk
,
123 dp
->d_ops
->data_dotdot_offset
);
126 * Put . entry unless we're starting past it.
128 if (ctx
->pos
<= dot_offset
) {
129 ctx
->pos
= dot_offset
& 0x7fffffff;
130 if (!dir_emit(ctx
, ".", 1, dp
->i_ino
, DT_DIR
))
135 * Put .. entry unless we're starting past it.
137 if (ctx
->pos
<= dotdot_offset
) {
138 ino
= dp
->d_ops
->sf_get_parent_ino(sfp
);
139 ctx
->pos
= dotdot_offset
& 0x7fffffff;
140 if (!dir_emit(ctx
, "..", 2, ino
, DT_DIR
))
145 * Loop while there are more entries and put'ing works.
147 sfep
= xfs_dir2_sf_firstentry(sfp
);
148 for (i
= 0; i
< sfp
->count
; i
++) {
151 off
= xfs_dir2_db_off_to_dataptr(geo
, geo
->datablk
,
152 xfs_dir2_sf_get_offset(sfep
));
154 if (ctx
->pos
> off
) {
155 sfep
= dp
->d_ops
->sf_nextentry(sfp
, sfep
);
159 ino
= dp
->d_ops
->sf_get_ino(sfp
, sfep
);
160 filetype
= dp
->d_ops
->sf_get_ftype(sfep
);
161 ctx
->pos
= off
& 0x7fffffff;
162 if (!dir_emit(ctx
, (char *)sfep
->name
, sfep
->namelen
, ino
,
163 xfs_dir3_get_dtype(dp
->i_mount
, filetype
)))
165 sfep
= dp
->d_ops
->sf_nextentry(sfp
, sfep
);
168 ctx
->pos
= xfs_dir2_db_off_to_dataptr(geo
, geo
->datablk
+ 1, 0) &
174 * Readdir for block directories.
177 xfs_dir2_block_getdents(
178 struct xfs_da_args
*args
,
179 struct dir_context
*ctx
)
181 struct xfs_inode
*dp
= args
->dp
; /* incore directory inode */
182 xfs_dir2_data_hdr_t
*hdr
; /* block header */
183 struct xfs_buf
*bp
; /* buffer for block */
184 xfs_dir2_block_tail_t
*btp
; /* block tail */
185 xfs_dir2_data_entry_t
*dep
; /* block data entry */
186 xfs_dir2_data_unused_t
*dup
; /* block unused entry */
187 char *endptr
; /* end of the data entries */
188 int error
; /* error return value */
189 char *ptr
; /* current data entry */
190 int wantoff
; /* starting block offset */
192 struct xfs_da_geometry
*geo
= args
->geo
;
195 * If the block number in the offset is out of range, we're done.
197 if (xfs_dir2_dataptr_to_db(geo
, ctx
->pos
) > geo
->datablk
)
200 error
= xfs_dir3_block_read(NULL
, dp
, &bp
);
205 * Extract the byte offset we start at from the seek pointer.
206 * We'll skip entries before this.
208 wantoff
= xfs_dir2_dataptr_to_off(geo
, ctx
->pos
);
210 xfs_dir3_data_check(dp
, bp
);
212 * Set up values for the loop.
214 btp
= xfs_dir2_block_tail_p(geo
, hdr
);
215 ptr
= (char *)dp
->d_ops
->data_entry_p(hdr
);
216 endptr
= (char *)xfs_dir2_block_leaf_p(btp
);
219 * Loop over the data portion of the block.
220 * Each object is a real entry (dep) or an unused one (dup).
222 while (ptr
< endptr
) {
225 dup
= (xfs_dir2_data_unused_t
*)ptr
;
229 if (be16_to_cpu(dup
->freetag
) == XFS_DIR2_DATA_FREE_TAG
) {
230 ptr
+= be16_to_cpu(dup
->length
);
234 dep
= (xfs_dir2_data_entry_t
*)ptr
;
237 * Bump pointer for the next iteration.
239 ptr
+= dp
->d_ops
->data_entsize(dep
->namelen
);
241 * The entry is before the desired starting point, skip it.
243 if ((char *)dep
- (char *)hdr
< wantoff
)
246 cook
= xfs_dir2_db_off_to_dataptr(geo
, geo
->datablk
,
247 (char *)dep
- (char *)hdr
);
249 ctx
->pos
= cook
& 0x7fffffff;
250 filetype
= dp
->d_ops
->data_get_ftype(dep
);
252 * If it didn't fit, set the final offset to here & return.
254 if (!dir_emit(ctx
, (char *)dep
->name
, dep
->namelen
,
255 be64_to_cpu(dep
->inumber
),
256 xfs_dir3_get_dtype(dp
->i_mount
, filetype
))) {
257 xfs_trans_brelse(NULL
, bp
);
263 * Reached the end of the block.
264 * Set the offset to a non-existent block 1 and return.
266 ctx
->pos
= xfs_dir2_db_off_to_dataptr(geo
, geo
->datablk
+ 1, 0) &
268 xfs_trans_brelse(NULL
, bp
);
272 struct xfs_dir2_leaf_map_info
{
273 xfs_extlen_t map_blocks
; /* number of fsbs in map */
274 xfs_dablk_t map_off
; /* last mapped file offset */
275 int map_size
; /* total entries in *map */
276 int map_valid
; /* valid entries in *map */
277 int nmap
; /* mappings to ask xfs_bmapi */
278 xfs_dir2_db_t curdb
; /* db for current block */
279 int ra_current
; /* number of read-ahead blks */
280 int ra_index
; /* *map index for read-ahead */
281 int ra_offset
; /* map entry offset for ra */
282 int ra_want
; /* readahead count wanted */
283 struct xfs_bmbt_irec map
[]; /* map vector for blocks */
287 xfs_dir2_leaf_readbuf(
288 struct xfs_da_args
*args
,
290 struct xfs_dir2_leaf_map_info
*mip
,
291 xfs_dir2_off_t
*curoff
,
292 struct xfs_buf
**bpp
)
294 struct xfs_inode
*dp
= args
->dp
;
295 struct xfs_buf
*bp
= *bpp
;
296 struct xfs_bmbt_irec
*map
= mip
->map
;
297 struct blk_plug plug
;
302 struct xfs_da_geometry
*geo
= args
->geo
;
305 * If we have a buffer, we need to release it and
306 * take it out of the mapping.
310 xfs_trans_brelse(NULL
, bp
);
312 mip
->map_blocks
-= geo
->fsbcount
;
314 * Loop to get rid of the extents for the
317 for (i
= geo
->fsbcount
; i
> 0; ) {
318 j
= min_t(int, map
->br_blockcount
, i
);
319 map
->br_blockcount
-= j
;
320 map
->br_startblock
+= j
;
321 map
->br_startoff
+= j
;
323 * If mapping is done, pitch it from
326 if (!map
->br_blockcount
&& --mip
->map_valid
)
327 memmove(&map
[0], &map
[1],
328 sizeof(map
[0]) * mip
->map_valid
);
334 * Recalculate the readahead blocks wanted.
336 mip
->ra_want
= howmany(bufsize
+ geo
->blksize
, (1 << geo
->fsblog
)) - 1;
337 ASSERT(mip
->ra_want
>= 0);
340 * If we don't have as many as we want, and we haven't
341 * run out of data blocks, get some more mappings.
343 if (1 + mip
->ra_want
> mip
->map_blocks
&&
344 mip
->map_off
< xfs_dir2_byte_to_da(geo
, XFS_DIR2_LEAF_OFFSET
)) {
346 * Get more bmaps, fill in after the ones
347 * we already have in the table.
349 mip
->nmap
= mip
->map_size
- mip
->map_valid
;
350 error
= xfs_bmapi_read(dp
, mip
->map_off
,
351 xfs_dir2_byte_to_da(geo
, XFS_DIR2_LEAF_OFFSET
) -
353 &map
[mip
->map_valid
], &mip
->nmap
, 0);
356 * Don't know if we should ignore this or try to return an
357 * error. The trouble with returning errors is that readdir
358 * will just stop without actually passing the error through.
364 * If we got all the mappings we asked for, set the final map
365 * offset based on the last bmap value received. Otherwise,
366 * we've reached the end.
368 if (mip
->nmap
== mip
->map_size
- mip
->map_valid
) {
369 i
= mip
->map_valid
+ mip
->nmap
- 1;
370 mip
->map_off
= map
[i
].br_startoff
+ map
[i
].br_blockcount
;
372 mip
->map_off
= xfs_dir2_byte_to_da(geo
,
373 XFS_DIR2_LEAF_OFFSET
);
376 * Look for holes in the mapping, and eliminate them. Count up
379 for (i
= mip
->map_valid
; i
< mip
->map_valid
+ mip
->nmap
; ) {
380 if (map
[i
].br_startblock
== HOLESTARTBLOCK
) {
382 length
= mip
->map_valid
+ mip
->nmap
- i
;
384 memmove(&map
[i
], &map
[i
+ 1],
385 sizeof(map
[i
]) * length
);
387 mip
->map_blocks
+= map
[i
].br_blockcount
;
391 mip
->map_valid
+= mip
->nmap
;
395 * No valid mappings, so no more data blocks.
397 if (!mip
->map_valid
) {
398 *curoff
= xfs_dir2_da_to_byte(geo
, mip
->map_off
);
403 * Read the directory block starting at the first mapping.
405 mip
->curdb
= xfs_dir2_da_to_db(geo
, map
->br_startoff
);
406 error
= xfs_dir3_data_read(NULL
, dp
, map
->br_startoff
,
407 map
->br_blockcount
>= geo
->fsbcount
?
408 XFS_FSB_TO_DADDR(dp
->i_mount
, map
->br_startblock
) :
411 * Should just skip over the data block instead of giving up.
417 * Adjust the current amount of read-ahead: we just read a block that
421 mip
->ra_current
-= geo
->fsbcount
;
424 * Do we need more readahead?
426 blk_start_plug(&plug
);
427 for (mip
->ra_index
= mip
->ra_offset
= i
= 0;
428 mip
->ra_want
> mip
->ra_current
&& i
< mip
->map_blocks
;
429 i
+= geo
->fsbcount
) {
430 ASSERT(mip
->ra_index
< mip
->map_valid
);
432 * Read-ahead a contiguous directory block.
434 if (i
> mip
->ra_current
&&
435 map
[mip
->ra_index
].br_blockcount
>= geo
->fsbcount
) {
436 xfs_dir3_data_readahead(dp
,
437 map
[mip
->ra_index
].br_startoff
+ mip
->ra_offset
,
438 XFS_FSB_TO_DADDR(dp
->i_mount
,
439 map
[mip
->ra_index
].br_startblock
+
445 * Read-ahead a non-contiguous directory block. This doesn't
446 * use our mapping, but this is a very rare case.
448 else if (i
> mip
->ra_current
) {
449 xfs_dir3_data_readahead(dp
,
450 map
[mip
->ra_index
].br_startoff
+
456 * Advance offset through the mapping table.
458 for (j
= 0; j
< geo
->fsbcount
; j
+= length
) {
460 * The rest of this extent but not more than a dir
463 length
= min_t(int, geo
->fsbcount
,
464 map
[mip
->ra_index
].br_blockcount
-
466 mip
->ra_offset
+= length
;
469 * Advance to the next mapping if this one is used up.
471 if (mip
->ra_offset
== map
[mip
->ra_index
].br_blockcount
) {
477 blk_finish_plug(&plug
);
485 * Getdents (readdir) for leaf and node directories.
486 * This reads the data blocks only, so is the same for both forms.
489 xfs_dir2_leaf_getdents(
490 struct xfs_da_args
*args
,
491 struct dir_context
*ctx
,
494 struct xfs_inode
*dp
= args
->dp
;
495 struct xfs_buf
*bp
= NULL
; /* data block buffer */
496 xfs_dir2_data_hdr_t
*hdr
; /* data block header */
497 xfs_dir2_data_entry_t
*dep
; /* data entry */
498 xfs_dir2_data_unused_t
*dup
; /* unused entry */
499 int error
= 0; /* error return value */
500 int length
; /* temporary length value */
501 int byteoff
; /* offset in current block */
502 xfs_dir2_off_t curoff
; /* current overall offset */
503 xfs_dir2_off_t newoff
; /* new curoff after new blk */
504 char *ptr
= NULL
; /* pointer to current data */
505 struct xfs_dir2_leaf_map_info
*map_info
;
506 struct xfs_da_geometry
*geo
= args
->geo
;
509 * If the offset is at or past the largest allowed value,
510 * give up right away.
512 if (ctx
->pos
>= XFS_DIR2_MAX_DATAPTR
)
516 * Set up to bmap a number of blocks based on the caller's
517 * buffer size, the directory block size, and the filesystem
520 length
= howmany(bufsize
+ geo
->blksize
, (1 << geo
->fsblog
));
521 map_info
= kmem_zalloc(offsetof(struct xfs_dir2_leaf_map_info
, map
) +
522 (length
* sizeof(struct xfs_bmbt_irec
)),
524 map_info
->map_size
= length
;
527 * Inside the loop we keep the main offset value as a byte offset
528 * in the directory file.
530 curoff
= xfs_dir2_dataptr_to_byte(ctx
->pos
);
533 * Force this conversion through db so we truncate the offset
534 * down to get the start of the data block.
536 map_info
->map_off
= xfs_dir2_db_to_da(geo
,
537 xfs_dir2_byte_to_db(geo
, curoff
));
540 * Loop over directory entries until we reach the end offset.
541 * Get more blocks and readahead as necessary.
543 while (curoff
< XFS_DIR2_LEAF_OFFSET
) {
547 * If we have no buffer, or we're off the end of the
548 * current buffer, need to get another one.
550 if (!bp
|| ptr
>= (char *)bp
->b_addr
+ geo
->blksize
) {
552 error
= xfs_dir2_leaf_readbuf(args
, bufsize
, map_info
,
554 if (error
|| !map_info
->map_valid
)
558 * Having done a read, we need to set a new offset.
560 newoff
= xfs_dir2_db_off_to_byte(geo
,
563 * Start of the current block.
568 * Make sure we're in the right block.
570 else if (curoff
> newoff
)
571 ASSERT(xfs_dir2_byte_to_db(geo
, curoff
) ==
574 xfs_dir3_data_check(dp
, bp
);
576 * Find our position in the block.
578 ptr
= (char *)dp
->d_ops
->data_entry_p(hdr
);
579 byteoff
= xfs_dir2_byte_to_off(geo
, curoff
);
581 * Skip past the header.
584 curoff
+= dp
->d_ops
->data_entry_offset
;
586 * Skip past entries until we reach our offset.
589 while ((char *)ptr
- (char *)hdr
< byteoff
) {
590 dup
= (xfs_dir2_data_unused_t
*)ptr
;
592 if (be16_to_cpu(dup
->freetag
)
593 == XFS_DIR2_DATA_FREE_TAG
) {
595 length
= be16_to_cpu(dup
->length
);
599 dep
= (xfs_dir2_data_entry_t
*)ptr
;
601 dp
->d_ops
->data_entsize(dep
->namelen
);
605 * Now set our real offset.
608 xfs_dir2_db_off_to_byte(geo
,
609 xfs_dir2_byte_to_db(geo
, curoff
),
610 (char *)ptr
- (char *)hdr
);
611 if (ptr
>= (char *)hdr
+ geo
->blksize
) {
617 * We have a pointer to an entry.
620 dup
= (xfs_dir2_data_unused_t
*)ptr
;
622 * No, it's unused, skip over it.
624 if (be16_to_cpu(dup
->freetag
) == XFS_DIR2_DATA_FREE_TAG
) {
625 length
= be16_to_cpu(dup
->length
);
631 dep
= (xfs_dir2_data_entry_t
*)ptr
;
632 length
= dp
->d_ops
->data_entsize(dep
->namelen
);
633 filetype
= dp
->d_ops
->data_get_ftype(dep
);
635 ctx
->pos
= xfs_dir2_byte_to_dataptr(curoff
) & 0x7fffffff;
636 if (!dir_emit(ctx
, (char *)dep
->name
, dep
->namelen
,
637 be64_to_cpu(dep
->inumber
),
638 xfs_dir3_get_dtype(dp
->i_mount
, filetype
)))
642 * Advance to next entry in the block.
646 /* bufsize may have just been a guess; don't go negative */
647 bufsize
= bufsize
> length
? bufsize
- length
: 0;
651 * All done. Set output offset value to current offset.
653 if (curoff
> xfs_dir2_dataptr_to_byte(XFS_DIR2_MAX_DATAPTR
))
654 ctx
->pos
= XFS_DIR2_MAX_DATAPTR
& 0x7fffffff;
656 ctx
->pos
= xfs_dir2_byte_to_dataptr(curoff
) & 0x7fffffff;
659 xfs_trans_brelse(NULL
, bp
);
668 struct xfs_inode
*dp
,
669 struct dir_context
*ctx
,
672 struct xfs_da_args args
= { NULL
};
677 trace_xfs_readdir(dp
);
679 if (XFS_FORCED_SHUTDOWN(dp
->i_mount
))
682 ASSERT(S_ISDIR(dp
->i_d
.di_mode
));
683 XFS_STATS_INC(xs_dir_getdents
);
686 args
.geo
= dp
->i_mount
->m_dir_geo
;
688 lock_mode
= xfs_ilock_data_map_shared(dp
);
689 if (dp
->i_d
.di_format
== XFS_DINODE_FMT_LOCAL
)
690 rval
= xfs_dir2_sf_getdents(&args
, ctx
);
691 else if ((rval
= xfs_dir2_isblock(&args
, &v
)))
694 rval
= xfs_dir2_block_getdents(&args
, ctx
);
696 rval
= xfs_dir2_leaf_getdents(&args
, ctx
, bufsize
);
697 xfs_iunlock(dp
, lock_mode
);