2 * Copyright (c) 2000-2006 Silicon Graphics, Inc.
3 * Copyright (c) 2012-2013 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_types.h"
24 #include "xfs_trans.h"
28 #include "xfs_mount.h"
29 #include "xfs_da_btree.h"
30 #include "xfs_bmap_btree.h"
31 #include "xfs_ialloc_btree.h"
32 #include "xfs_dinode.h"
33 #include "xfs_inode.h"
34 #include "xfs_inode_item.h"
35 #include "xfs_itable.h"
36 #include "xfs_ialloc.h"
37 #include "xfs_alloc.h"
39 #include "xfs_error.h"
40 #include "xfs_quota.h"
41 #include "xfs_utils.h"
42 #include "xfs_trans_space.h"
43 #include "xfs_log_priv.h"
44 #include "xfs_trace.h"
45 #include "xfs_symlink.h"
46 #include "xfs_cksum.h"
47 #include "xfs_buf_item.h"
51 * Each contiguous block has a header, so it is not just a simple pathlen
59 int buflen
= XFS_SYMLINK_BUF_SPACE(mp
, mp
->m_sb
.sb_blocksize
);
61 return (pathlen
+ buflen
- 1) / buflen
;
72 struct xfs_dsymlink_hdr
*dsl
= bp
->b_addr
;
74 if (!xfs_sb_version_hascrc(&mp
->m_sb
))
77 dsl
->sl_magic
= cpu_to_be32(XFS_SYMLINK_MAGIC
);
78 dsl
->sl_offset
= cpu_to_be32(offset
);
79 dsl
->sl_bytes
= cpu_to_be32(size
);
80 uuid_copy(&dsl
->sl_uuid
, &mp
->m_sb
.sb_uuid
);
81 dsl
->sl_owner
= cpu_to_be64(ino
);
82 dsl
->sl_blkno
= cpu_to_be64(bp
->b_bn
);
83 bp
->b_ops
= &xfs_symlink_buf_ops
;
85 return sizeof(struct xfs_dsymlink_hdr
);
89 * Checking of the symlink header is split into two parts. the verifier does
90 * CRC, location and bounds checking, the unpacking function checks the path
91 * parameters and owner.
101 struct xfs_dsymlink_hdr
*dsl
= bp
->b_addr
;
103 if (offset
!= be32_to_cpu(dsl
->sl_offset
))
105 if (size
!= be32_to_cpu(dsl
->sl_bytes
))
107 if (ino
!= be64_to_cpu(dsl
->sl_owner
))
118 struct xfs_mount
*mp
= bp
->b_target
->bt_mount
;
119 struct xfs_dsymlink_hdr
*dsl
= bp
->b_addr
;
121 if (!xfs_sb_version_hascrc(&mp
->m_sb
))
123 if (dsl
->sl_magic
!= cpu_to_be32(XFS_SYMLINK_MAGIC
))
125 if (!uuid_equal(&dsl
->sl_uuid
, &mp
->m_sb
.sb_uuid
))
127 if (bp
->b_bn
!= be64_to_cpu(dsl
->sl_blkno
))
129 if (be32_to_cpu(dsl
->sl_offset
) +
130 be32_to_cpu(dsl
->sl_bytes
) >= MAXPATHLEN
)
132 if (dsl
->sl_owner
== 0)
139 xfs_symlink_read_verify(
142 struct xfs_mount
*mp
= bp
->b_target
->bt_mount
;
144 /* no verification of non-crc buffers */
145 if (!xfs_sb_version_hascrc(&mp
->m_sb
))
148 if (!xfs_verify_cksum(bp
->b_addr
, BBTOB(bp
->b_length
),
149 offsetof(struct xfs_dsymlink_hdr
, sl_crc
)) ||
150 !xfs_symlink_verify(bp
)) {
151 XFS_CORRUPTION_ERROR(__func__
, XFS_ERRLEVEL_LOW
, mp
, bp
->b_addr
);
152 xfs_buf_ioerror(bp
, EFSCORRUPTED
);
157 xfs_symlink_write_verify(
160 struct xfs_mount
*mp
= bp
->b_target
->bt_mount
;
161 struct xfs_buf_log_item
*bip
= bp
->b_fspriv
;
163 /* no verification of non-crc buffers */
164 if (!xfs_sb_version_hascrc(&mp
->m_sb
))
167 if (!xfs_symlink_verify(bp
)) {
168 XFS_CORRUPTION_ERROR(__func__
, XFS_ERRLEVEL_LOW
, mp
, bp
->b_addr
);
169 xfs_buf_ioerror(bp
, EFSCORRUPTED
);
174 struct xfs_dsymlink_hdr
*dsl
= bp
->b_addr
;
175 dsl
->sl_lsn
= cpu_to_be64(bip
->bli_item
.li_lsn
);
177 xfs_update_cksum(bp
->b_addr
, BBTOB(bp
->b_length
),
178 offsetof(struct xfs_dsymlink_hdr
, sl_crc
));
181 const struct xfs_buf_ops xfs_symlink_buf_ops
= {
182 .verify_read
= xfs_symlink_read_verify
,
183 .verify_write
= xfs_symlink_write_verify
,
187 xfs_symlink_local_to_remote(
188 struct xfs_trans
*tp
,
190 struct xfs_inode
*ip
,
191 struct xfs_ifork
*ifp
)
193 struct xfs_mount
*mp
= ip
->i_mount
;
196 if (!xfs_sb_version_hascrc(&mp
->m_sb
)) {
198 memcpy(bp
->b_addr
, ifp
->if_u1
.if_data
, ifp
->if_bytes
);
203 * As this symlink fits in an inode literal area, it must also fit in
204 * the smallest buffer the filesystem supports.
206 ASSERT(BBTOB(bp
->b_length
) >=
207 ifp
->if_bytes
+ sizeof(struct xfs_dsymlink_hdr
));
209 bp
->b_ops
= &xfs_symlink_buf_ops
;
212 buf
+= xfs_symlink_hdr_set(mp
, ip
->i_ino
, 0, ifp
->if_bytes
, bp
);
213 memcpy(buf
, ifp
->if_u1
.if_data
, ifp
->if_bytes
);
216 /* ----- Kernel only functions below ----- */
219 struct xfs_inode
*ip
,
222 struct xfs_mount
*mp
= ip
->i_mount
;
223 struct xfs_bmbt_irec mval
[XFS_SYMLINK_MAPS
];
227 int pathlen
= ip
->i_d
.di_size
;
228 int nmaps
= XFS_SYMLINK_MAPS
;
235 fsblocks
= xfs_symlink_blocks(mp
, pathlen
);
236 error
= xfs_bmapi_read(ip
, 0, fsblocks
, mval
, &nmaps
, 0);
241 for (n
= 0; n
< nmaps
; n
++) {
242 d
= XFS_FSB_TO_DADDR(mp
, mval
[n
].br_startblock
);
243 byte_cnt
= XFS_FSB_TO_B(mp
, mval
[n
].br_blockcount
);
245 bp
= xfs_buf_read(mp
->m_ddev_targp
, d
, BTOBB(byte_cnt
), 0,
246 &xfs_symlink_buf_ops
);
248 return XFS_ERROR(ENOMEM
);
251 xfs_buf_ioerror_alert(bp
, __func__
);
255 byte_cnt
= XFS_SYMLINK_BUF_SPACE(mp
, byte_cnt
);
256 if (pathlen
< byte_cnt
)
259 cur_chunk
= bp
->b_addr
;
260 if (xfs_sb_version_hascrc(&mp
->m_sb
)) {
261 if (!xfs_symlink_hdr_ok(mp
, ip
->i_ino
, offset
,
263 error
= EFSCORRUPTED
;
265 "symlink header does not match required off/len/owner (0x%x/Ox%x,0x%llx)",
266 offset
, byte_cnt
, ip
->i_ino
);
272 cur_chunk
+= sizeof(struct xfs_dsymlink_hdr
);
275 memcpy(link
+ offset
, bp
->b_addr
, byte_cnt
);
282 ASSERT(pathlen
== 0);
284 link
[ip
->i_d
.di_size
] = '\0';
293 struct xfs_inode
*ip
,
296 struct xfs_mount
*mp
= ip
->i_mount
;
300 trace_xfs_readlink(ip
);
302 if (XFS_FORCED_SHUTDOWN(mp
))
303 return XFS_ERROR(EIO
);
305 xfs_ilock(ip
, XFS_ILOCK_SHARED
);
307 pathlen
= ip
->i_d
.di_size
;
311 if (pathlen
< 0 || pathlen
> MAXPATHLEN
) {
312 xfs_alert(mp
, "%s: inode (%llu) bad symlink length (%lld)",
313 __func__
, (unsigned long long) ip
->i_ino
,
314 (long long) pathlen
);
316 error
= XFS_ERROR(EFSCORRUPTED
);
321 if (ip
->i_df
.if_flags
& XFS_IFINLINE
) {
322 memcpy(link
, ip
->i_df
.if_u1
.if_data
, pathlen
);
323 link
[pathlen
] = '\0';
325 error
= xfs_readlink_bmap(ip
, link
);
329 xfs_iunlock(ip
, XFS_ILOCK_SHARED
);
335 struct xfs_inode
*dp
,
336 struct xfs_name
*link_name
,
337 const char *target_path
,
339 struct xfs_inode
**ipp
)
341 struct xfs_mount
*mp
= dp
->i_mount
;
342 struct xfs_trans
*tp
= NULL
;
343 struct xfs_inode
*ip
= NULL
;
346 struct xfs_bmap_free free_list
;
347 xfs_fsblock_t first_block
;
348 bool unlock_dp_on_error
= false;
351 xfs_fileoff_t first_fsb
;
352 xfs_filblks_t fs_blocks
;
354 struct xfs_bmbt_irec mval
[XFS_SYMLINK_MAPS
];
356 const char *cur_chunk
;
361 struct xfs_dquot
*udqp
= NULL
;
362 struct xfs_dquot
*gdqp
= NULL
;
363 struct xfs_dquot
*pdqp
= NULL
;
368 trace_xfs_symlink(dp
, link_name
);
370 if (XFS_FORCED_SHUTDOWN(mp
))
371 return XFS_ERROR(EIO
);
374 * Check component lengths of the target path name.
376 pathlen
= strlen(target_path
);
377 if (pathlen
>= MAXPATHLEN
) /* total string too long */
378 return XFS_ERROR(ENAMETOOLONG
);
381 if (dp
->i_d
.di_flags
& XFS_DIFLAG_PROJINHERIT
)
382 prid
= xfs_get_projid(dp
);
384 prid
= XFS_PROJID_DEFAULT
;
387 * Make sure that we have allocated dquot(s) on disk.
389 error
= xfs_qm_vop_dqalloc(dp
, current_fsuid(), current_fsgid(), prid
,
390 XFS_QMOPT_QUOTALL
| XFS_QMOPT_INHERIT
, &udqp
, &gdqp
, &pdqp
);
394 tp
= xfs_trans_alloc(mp
, XFS_TRANS_SYMLINK
);
395 cancel_flags
= XFS_TRANS_RELEASE_LOG_RES
;
397 * The symlink will fit into the inode data fork?
398 * There can't be any attributes so we get the whole variable part.
400 if (pathlen
<= XFS_LITINO(mp
, dp
->i_d
.di_version
))
403 fs_blocks
= xfs_symlink_blocks(mp
, pathlen
);
404 resblks
= XFS_SYMLINK_SPACE_RES(mp
, link_name
->len
, fs_blocks
);
405 error
= xfs_trans_reserve(tp
, resblks
, XFS_SYMLINK_LOG_RES(mp
), 0,
406 XFS_TRANS_PERM_LOG_RES
, XFS_SYMLINK_LOG_COUNT
);
407 if (error
== ENOSPC
&& fs_blocks
== 0) {
409 error
= xfs_trans_reserve(tp
, 0, XFS_SYMLINK_LOG_RES(mp
), 0,
410 XFS_TRANS_PERM_LOG_RES
, XFS_SYMLINK_LOG_COUNT
);
417 xfs_ilock(dp
, XFS_ILOCK_EXCL
| XFS_ILOCK_PARENT
);
418 unlock_dp_on_error
= true;
421 * Check whether the directory allows new symlinks or not.
423 if (dp
->i_d
.di_flags
& XFS_DIFLAG_NOSYMLINKS
) {
424 error
= XFS_ERROR(EPERM
);
429 * Reserve disk quota : blocks and inode.
431 error
= xfs_trans_reserve_quota(tp
, mp
, udqp
, gdqp
,
432 pdqp
, resblks
, 1, 0);
437 * Check for ability to enter directory entry, if no space reserved.
439 error
= xfs_dir_canenter(tp
, dp
, link_name
, resblks
);
443 * Initialize the bmap freelist prior to calling either
444 * bmapi or the directory create code.
446 xfs_bmap_init(&free_list
, &first_block
);
449 * Allocate an inode for the symlink.
451 error
= xfs_dir_ialloc(&tp
, dp
, S_IFLNK
| (mode
& ~S_IFMT
), 1, 0,
452 prid
, resblks
> 0, &ip
, NULL
);
460 * An error after we've joined dp to the transaction will result in the
461 * transaction cancel unlocking dp so don't do it explicitly in the
464 xfs_trans_ijoin(tp
, dp
, XFS_ILOCK_EXCL
);
465 unlock_dp_on_error
= false;
468 * Also attach the dquot(s) to it, if applicable.
470 xfs_qm_vop_create_dqattach(tp
, ip
, udqp
, gdqp
, pdqp
);
473 resblks
-= XFS_IALLOC_SPACE_RES(mp
);
475 * If the symlink will fit into the inode, write it inline.
477 if (pathlen
<= XFS_IFORK_DSIZE(ip
)) {
478 xfs_idata_realloc(ip
, pathlen
, XFS_DATA_FORK
);
479 memcpy(ip
->i_df
.if_u1
.if_data
, target_path
, pathlen
);
480 ip
->i_d
.di_size
= pathlen
;
483 * The inode was initially created in extent format.
485 ip
->i_df
.if_flags
&= ~(XFS_IFEXTENTS
| XFS_IFBROOT
);
486 ip
->i_df
.if_flags
|= XFS_IFINLINE
;
488 ip
->i_d
.di_format
= XFS_DINODE_FMT_LOCAL
;
489 xfs_trans_log_inode(tp
, ip
, XFS_ILOG_DDATA
| XFS_ILOG_CORE
);
495 nmaps
= XFS_SYMLINK_MAPS
;
497 error
= xfs_bmapi_write(tp
, ip
, first_fsb
, fs_blocks
,
498 XFS_BMAPI_METADATA
, &first_block
, resblks
,
499 mval
, &nmaps
, &free_list
);
504 resblks
-= fs_blocks
;
505 ip
->i_d
.di_size
= pathlen
;
506 xfs_trans_log_inode(tp
, ip
, XFS_ILOG_CORE
);
508 cur_chunk
= target_path
;
510 for (n
= 0; n
< nmaps
; n
++) {
513 d
= XFS_FSB_TO_DADDR(mp
, mval
[n
].br_startblock
);
514 byte_cnt
= XFS_FSB_TO_B(mp
, mval
[n
].br_blockcount
);
515 bp
= xfs_trans_get_buf(tp
, mp
->m_ddev_targp
, d
,
521 bp
->b_ops
= &xfs_symlink_buf_ops
;
523 byte_cnt
= XFS_SYMLINK_BUF_SPACE(mp
, byte_cnt
);
524 byte_cnt
= min(byte_cnt
, pathlen
);
527 buf
+= xfs_symlink_hdr_set(mp
, ip
->i_ino
, offset
,
530 memcpy(buf
, cur_chunk
, byte_cnt
);
532 cur_chunk
+= byte_cnt
;
536 xfs_trans_log_buf(tp
, bp
, 0, (buf
+ byte_cnt
- 1) -
539 ASSERT(pathlen
== 0);
543 * Create the directory entry for the symlink.
545 error
= xfs_dir_createname(tp
, dp
, link_name
, ip
->i_ino
,
546 &first_block
, &free_list
, resblks
);
549 xfs_trans_ichgtime(tp
, dp
, XFS_ICHGTIME_MOD
| XFS_ICHGTIME_CHG
);
550 xfs_trans_log_inode(tp
, dp
, XFS_ILOG_CORE
);
553 * If this is a synchronous mount, make sure that the
554 * symlink transaction goes to disk before returning to
557 if (mp
->m_flags
& (XFS_MOUNT_WSYNC
|XFS_MOUNT_DIRSYNC
)) {
558 xfs_trans_set_sync(tp
);
561 error
= xfs_bmap_finish(&tp
, &free_list
, &committed
);
565 error
= xfs_trans_commit(tp
, XFS_TRANS_RELEASE_LOG_RES
);
576 xfs_bmap_cancel(&free_list
);
577 cancel_flags
|= XFS_TRANS_ABORT
;
579 xfs_trans_cancel(tp
, cancel_flags
);
584 if (unlock_dp_on_error
)
585 xfs_iunlock(dp
, XFS_ILOCK_EXCL
);
591 * Free a symlink that has blocks associated with it.
594 xfs_inactive_symlink_rmt(
602 xfs_fsblock_t first_block
;
603 xfs_bmap_free_t free_list
;
606 xfs_bmbt_irec_t mval
[XFS_SYMLINK_MAPS
];
614 ASSERT(ip
->i_df
.if_flags
& XFS_IFEXTENTS
);
616 * We're freeing a symlink that has some
617 * blocks allocated to it. Free the
618 * blocks here. We know that we've got
619 * either 1 or 2 extents and that we can
620 * free them all in one bunmapi call.
622 ASSERT(ip
->i_d
.di_nextents
> 0 && ip
->i_d
.di_nextents
<= 2);
625 * Lock the inode, fix the size, and join it to the transaction.
626 * Hold it so in the normal path, we still have it locked for
627 * the second transaction. In the error paths we need it
628 * held so the cancel won't rele it, see below.
630 size
= (int)ip
->i_d
.di_size
;
632 xfs_trans_log_inode(tp
, ip
, XFS_ILOG_CORE
);
634 * Find the block(s) so we can inval and unmap them.
637 xfs_bmap_init(&free_list
, &first_block
);
638 nmaps
= ARRAY_SIZE(mval
);
639 error
= xfs_bmapi_read(ip
, 0, xfs_symlink_blocks(mp
, size
),
644 * Invalidate the block(s). No validation is done.
646 for (i
= 0; i
< nmaps
; i
++) {
647 bp
= xfs_trans_get_buf(tp
, mp
->m_ddev_targp
,
648 XFS_FSB_TO_DADDR(mp
, mval
[i
].br_startblock
),
649 XFS_FSB_TO_BB(mp
, mval
[i
].br_blockcount
), 0);
654 xfs_trans_binval(tp
, bp
);
657 * Unmap the dead block(s) to the free_list.
659 if ((error
= xfs_bunmapi(tp
, ip
, 0, size
, XFS_BMAPI_METADATA
, nmaps
,
660 &first_block
, &free_list
, &done
)))
664 * Commit the first transaction. This logs the EFI and the inode.
666 if ((error
= xfs_bmap_finish(&tp
, &free_list
, &committed
)))
669 * The transaction must have been committed, since there were
670 * actually extents freed by xfs_bunmapi. See xfs_bmap_finish.
671 * The new tp has the extent freeing and EFDs.
675 * The first xact was committed, so add the inode to the new one.
676 * Mark it dirty so it will be logged and moved forward in the log as
677 * part of every commit.
679 xfs_trans_ijoin(tp
, ip
, 0);
680 xfs_trans_log_inode(tp
, ip
, XFS_ILOG_CORE
);
682 * Get a new, empty transaction to return to our caller.
684 ntp
= xfs_trans_dup(tp
);
686 * Commit the transaction containing extent freeing and EFDs.
687 * If we get an error on the commit here or on the reserve below,
688 * we need to unlock the inode since the new transaction doesn't
689 * have the inode attached.
691 error
= xfs_trans_commit(tp
, 0);
694 ASSERT(XFS_FORCED_SHUTDOWN(mp
));
698 * transaction commit worked ok so we can drop the extra ticket
699 * reference that we gained in xfs_trans_dup()
701 xfs_log_ticket_put(tp
->t_ticket
);
704 * Remove the memory for extent descriptions (just bookkeeping).
706 if (ip
->i_df
.if_bytes
)
707 xfs_idata_realloc(ip
, -ip
->i_df
.if_bytes
, XFS_DATA_FORK
);
708 ASSERT(ip
->i_df
.if_bytes
== 0);
710 * Put an itruncate log reservation in the new transaction
713 if ((error
= xfs_trans_reserve(tp
, 0, XFS_ITRUNCATE_LOG_RES(mp
), 0,
714 XFS_TRANS_PERM_LOG_RES
, XFS_ITRUNCATE_LOG_COUNT
))) {
715 ASSERT(XFS_FORCED_SHUTDOWN(mp
));
719 xfs_trans_ijoin(tp
, ip
, 0);
724 xfs_bmap_cancel(&free_list
);
730 * xfs_inactive_symlink - free a symlink
733 xfs_inactive_symlink(
734 struct xfs_inode
*ip
,
735 struct xfs_trans
**tp
)
737 struct xfs_mount
*mp
= ip
->i_mount
;
740 trace_xfs_inactive_symlink(ip
);
742 ASSERT(xfs_isilocked(ip
, XFS_ILOCK_EXCL
));
744 if (XFS_FORCED_SHUTDOWN(mp
))
745 return XFS_ERROR(EIO
);
748 * Zero length symlinks _can_ exist.
750 pathlen
= (int)ip
->i_d
.di_size
;
754 if (pathlen
< 0 || pathlen
> MAXPATHLEN
) {
755 xfs_alert(mp
, "%s: inode (0x%llx) bad symlink length (%d)",
756 __func__
, (unsigned long long)ip
->i_ino
, pathlen
);
758 return XFS_ERROR(EFSCORRUPTED
);
761 if (ip
->i_df
.if_flags
& XFS_IFINLINE
) {
762 if (ip
->i_df
.if_bytes
> 0)
763 xfs_idata_realloc(ip
, -(ip
->i_df
.if_bytes
),
765 ASSERT(ip
->i_df
.if_bytes
== 0);
769 /* remove the remote symlink */
770 return xfs_inactive_symlink_rmt(ip
, tp
);