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
64 len -= XFS_SYMLINK_BUF_SPACE(mp, mp->m_sb.sb_blocksize);
67 ASSERT(fsblocks <= XFS_SYMLINK_MAPS);
79 struct xfs_dsymlink_hdr *dsl = bp->b_addr;
81 if (!xfs_sb_version_hascrc(&mp->m_sb))
84 dsl->sl_magic = cpu_to_be32(XFS_SYMLINK_MAGIC);
85 dsl->sl_offset = cpu_to_be32(offset);
86 dsl->sl_bytes = cpu_to_be32(size);
87 uuid_copy(&dsl->sl_uuid, &mp->m_sb.sb_uuid);
88 dsl->sl_owner = cpu_to_be64(ino);
89 dsl->sl_blkno = cpu_to_be64(bp->b_bn);
90 bp->b_ops = &xfs_symlink_buf_ops;
92 return sizeof(struct xfs_dsymlink_hdr);
96 * Checking of the symlink header is split into two parts. the verifier does
97 * CRC, location and bounds checking, the unpacking function checks the path
98 * parameters and owner.
102 struct xfs_mount *mp,
108 struct xfs_dsymlink_hdr *dsl = bp->b_addr;
110 if (offset != be32_to_cpu(dsl->sl_offset))
112 if (size != be32_to_cpu(dsl->sl_bytes))
114 if (ino != be64_to_cpu(dsl->sl_owner))
125 struct xfs_mount *mp = bp->b_target->bt_mount;
126 struct xfs_dsymlink_hdr *dsl = bp->b_addr;
128 if (!xfs_sb_version_hascrc(&mp->m_sb))
130 if (dsl->sl_magic != cpu_to_be32(XFS_SYMLINK_MAGIC))
132 if (!uuid_equal(&dsl->sl_uuid, &mp->m_sb.sb_uuid))
134 if (bp->b_bn != be64_to_cpu(dsl->sl_blkno))
136 if (be32_to_cpu(dsl->sl_offset) +
137 be32_to_cpu(dsl->sl_bytes) >= MAXPATHLEN)
139 if (dsl->sl_owner == 0)
146 xfs_symlink_read_verify(
149 struct xfs_mount *mp = bp->b_target->bt_mount;
151 /* no verification of non-crc buffers */
152 if (!xfs_sb_version_hascrc(&mp->m_sb))
155 if (!xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length),
156 offsetof(struct xfs_dsymlink_hdr, sl_crc)) ||
157 !xfs_symlink_verify(bp)) {
158 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
159 xfs_buf_ioerror(bp, EFSCORRUPTED);
164 xfs_symlink_write_verify(
167 struct xfs_mount *mp = bp->b_target->bt_mount;
168 struct xfs_buf_log_item *bip = bp->b_fspriv;
170 /* no verification of non-crc buffers */
171 if (!xfs_sb_version_hascrc(&mp->m_sb))
174 if (!xfs_symlink_verify(bp)) {
175 XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
176 xfs_buf_ioerror(bp, EFSCORRUPTED);
181 struct xfs_dsymlink_hdr *dsl = bp->b_addr;
182 dsl->sl_lsn = cpu_to_be64(bip->bli_item.li_lsn);
184 xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length),
185 offsetof(struct xfs_dsymlink_hdr, sl_crc));
188 const struct xfs_buf_ops xfs_symlink_buf_ops = {
189 .verify_read = xfs_symlink_read_verify,
190 .verify_write = xfs_symlink_write_verify,
194 xfs_symlink_local_to_remote(
195 struct xfs_trans *tp,
197 struct xfs_inode *ip,
198 struct xfs_ifork *ifp)
200 struct xfs_mount *mp = ip->i_mount;
203 if (!xfs_sb_version_hascrc(&mp->m_sb)) {
205 memcpy(bp->b_addr, ifp->if_u1.if_data, ifp->if_bytes);
210 * As this symlink fits in an inode literal area, it must also fit in
211 * the smallest buffer the filesystem supports.
213 ASSERT(BBTOB(bp->b_length) >=
214 ifp->if_bytes + sizeof(struct xfs_dsymlink_hdr));
216 bp->b_ops = &xfs_symlink_buf_ops;
219 buf += xfs_symlink_hdr_set(mp, ip->i_ino, 0, ifp->if_bytes, bp);
220 memcpy(buf, ifp->if_u1.if_data, ifp->if_bytes);
223 /* ----- Kernel only functions below ----- */
226 struct xfs_inode *ip,
229 struct xfs_mount *mp = ip->i_mount;
230 struct xfs_bmbt_irec mval[XFS_SYMLINK_MAPS];
234 int pathlen = ip->i_d.di_size;
235 int nmaps = XFS_SYMLINK_MAPS;
242 fsblocks = xfs_symlink_blocks(mp, pathlen);
243 error = xfs_bmapi_read(ip, 0, fsblocks, mval, &nmaps, 0);
248 for (n = 0; n < nmaps; n++) {
249 d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock);
250 byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);
252 bp = xfs_buf_read(mp->m_ddev_targp, d, BTOBB(byte_cnt), 0,
253 &xfs_symlink_buf_ops);
255 return XFS_ERROR(ENOMEM);
258 xfs_buf_ioerror_alert(bp, __func__);
262 byte_cnt = XFS_SYMLINK_BUF_SPACE(mp, byte_cnt);
263 if (pathlen < byte_cnt)
266 cur_chunk = bp->b_addr;
267 if (xfs_sb_version_hascrc(&mp->m_sb)) {
268 if (!xfs_symlink_hdr_ok(mp, ip->i_ino, offset,
270 error = EFSCORRUPTED;
272 "symlink header does not match required off/len/owner (0x%x/Ox%x,0x%llx)",
273 offset, byte_cnt, ip->i_ino);
279 cur_chunk += sizeof(struct xfs_dsymlink_hdr);
282 memcpy(link + offset, bp->b_addr, byte_cnt);
289 ASSERT(pathlen == 0);
291 link[ip->i_d.di_size] = '\0';
300 struct xfs_inode *ip,
303 struct xfs_mount *mp = ip->i_mount;
307 trace_xfs_readlink(ip);
309 if (XFS_FORCED_SHUTDOWN(mp))
310 return XFS_ERROR(EIO);
312 xfs_ilock(ip, XFS_ILOCK_SHARED);
314 pathlen = ip->i_d.di_size;
318 if (pathlen < 0 || pathlen > MAXPATHLEN) {
319 xfs_alert(mp, "%s: inode (%llu) bad symlink length (%lld)",
320 __func__, (unsigned long long) ip->i_ino,
321 (long long) pathlen);
323 error = XFS_ERROR(EFSCORRUPTED);
328 if (ip->i_df.if_flags & XFS_IFINLINE) {
329 memcpy(link, ip->i_df.if_u1.if_data, pathlen);
330 link[pathlen] = '\0';
332 error = xfs_readlink_bmap(ip, link);
336 xfs_iunlock(ip, XFS_ILOCK_SHARED);
342 struct xfs_inode *dp,
343 struct xfs_name *link_name,
344 const char *target_path,
346 struct xfs_inode **ipp)
348 struct xfs_mount *mp = dp->i_mount;
349 struct xfs_trans *tp = NULL;
350 struct xfs_inode *ip = NULL;
353 struct xfs_bmap_free free_list;
354 xfs_fsblock_t first_block;
355 bool unlock_dp_on_error = false;
358 xfs_fileoff_t first_fsb;
359 xfs_filblks_t fs_blocks;
361 struct xfs_bmbt_irec mval[XFS_SYMLINK_MAPS];
363 const char *cur_chunk;
368 struct xfs_dquot *udqp, *gdqp;
373 trace_xfs_symlink(dp, link_name);
375 if (XFS_FORCED_SHUTDOWN(mp))
376 return XFS_ERROR(EIO);
379 * Check component lengths of the target path name.
381 pathlen = strlen(target_path);
382 if (pathlen >= MAXPATHLEN) /* total string too long */
383 return XFS_ERROR(ENAMETOOLONG);
386 if (dp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT)
387 prid = xfs_get_projid(dp);
389 prid = XFS_PROJID_DEFAULT;
392 * Make sure that we have allocated dquot(s) on disk.
394 error = xfs_qm_vop_dqalloc(dp, current_fsuid(), current_fsgid(), prid,
395 XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT, &udqp, &gdqp);
399 tp = xfs_trans_alloc(mp, XFS_TRANS_SYMLINK);
400 cancel_flags = XFS_TRANS_RELEASE_LOG_RES;
402 * The symlink will fit into the inode data fork?
403 * There can't be any attributes so we get the whole variable part.
405 if (pathlen <= XFS_LITINO(mp, dp->i_d.di_version))
408 fs_blocks = XFS_B_TO_FSB(mp, pathlen);
409 resblks = XFS_SYMLINK_SPACE_RES(mp, link_name->len, fs_blocks);
410 error = xfs_trans_reserve(tp, resblks, XFS_SYMLINK_LOG_RES(mp), 0,
411 XFS_TRANS_PERM_LOG_RES, XFS_SYMLINK_LOG_COUNT);
412 if (error == ENOSPC && fs_blocks == 0) {
414 error = xfs_trans_reserve(tp, 0, XFS_SYMLINK_LOG_RES(mp), 0,
415 XFS_TRANS_PERM_LOG_RES, XFS_SYMLINK_LOG_COUNT);
422 xfs_ilock(dp, XFS_ILOCK_EXCL | XFS_ILOCK_PARENT);
423 unlock_dp_on_error = true;
426 * Check whether the directory allows new symlinks or not.
428 if (dp->i_d.di_flags & XFS_DIFLAG_NOSYMLINKS) {
429 error = XFS_ERROR(EPERM);
434 * Reserve disk quota : blocks and inode.
436 error = xfs_trans_reserve_quota(tp, mp, udqp, gdqp, resblks, 1, 0);
441 * Check for ability to enter directory entry, if no space reserved.
443 error = xfs_dir_canenter(tp, dp, link_name, resblks);
447 * Initialize the bmap freelist prior to calling either
448 * bmapi or the directory create code.
450 xfs_bmap_init(&free_list, &first_block);
453 * Allocate an inode for the symlink.
455 error = xfs_dir_ialloc(&tp, dp, S_IFLNK | (mode & ~S_IFMT), 1, 0,
456 prid, resblks > 0, &ip, NULL);
464 * An error after we've joined dp to the transaction will result in the
465 * transaction cancel unlocking dp so don't do it explicitly in the
468 xfs_trans_ijoin(tp, dp, XFS_ILOCK_EXCL);
469 unlock_dp_on_error = false;
472 * Also attach the dquot(s) to it, if applicable.
474 xfs_qm_vop_create_dqattach(tp, ip, udqp, gdqp);
477 resblks -= XFS_IALLOC_SPACE_RES(mp);
479 * If the symlink will fit into the inode, write it inline.
481 if (pathlen <= XFS_IFORK_DSIZE(ip)) {
482 xfs_idata_realloc(ip, pathlen, XFS_DATA_FORK);
483 memcpy(ip->i_df.if_u1.if_data, target_path, pathlen);
484 ip->i_d.di_size = pathlen;
487 * The inode was initially created in extent format.
489 ip->i_df.if_flags &= ~(XFS_IFEXTENTS | XFS_IFBROOT);
490 ip->i_df.if_flags |= XFS_IFINLINE;
492 ip->i_d.di_format = XFS_DINODE_FMT_LOCAL;
493 xfs_trans_log_inode(tp, ip, XFS_ILOG_DDATA | XFS_ILOG_CORE);
499 nmaps = XFS_SYMLINK_MAPS;
501 error = xfs_bmapi_write(tp, ip, first_fsb, fs_blocks,
502 XFS_BMAPI_METADATA, &first_block, resblks,
503 mval, &nmaps, &free_list);
508 resblks -= fs_blocks;
509 ip->i_d.di_size = pathlen;
510 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
512 cur_chunk = target_path;
514 for (n = 0; n < nmaps; n++) {
517 d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock);
518 byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);
519 bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d,
525 bp->b_ops = &xfs_symlink_buf_ops;
527 byte_cnt = XFS_SYMLINK_BUF_SPACE(mp, byte_cnt);
528 if (pathlen < byte_cnt) {
533 buf += xfs_symlink_hdr_set(mp, ip->i_ino, offset,
536 memcpy(buf, cur_chunk, byte_cnt);
538 cur_chunk += byte_cnt;
542 xfs_trans_log_buf(tp, bp, 0, (buf + byte_cnt - 1) -
548 * Create the directory entry for the symlink.
550 error = xfs_dir_createname(tp, dp, link_name, ip->i_ino,
551 &first_block, &free_list, resblks);
554 xfs_trans_ichgtime(tp, dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
555 xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
558 * If this is a synchronous mount, make sure that the
559 * symlink transaction goes to disk before returning to
562 if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC)) {
563 xfs_trans_set_sync(tp);
566 error = xfs_bmap_finish(&tp, &free_list, &committed);
570 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
580 xfs_bmap_cancel(&free_list);
581 cancel_flags |= XFS_TRANS_ABORT;
583 xfs_trans_cancel(tp, cancel_flags);
587 if (unlock_dp_on_error)
588 xfs_iunlock(dp, XFS_ILOCK_EXCL);
594 * Free a symlink that has blocks associated with it.
597 xfs_inactive_symlink_rmt(
605 xfs_fsblock_t first_block;
606 xfs_bmap_free_t free_list;
609 xfs_bmbt_irec_t mval[XFS_SYMLINK_MAPS];
617 ASSERT(ip->i_d.di_size > XFS_IFORK_DSIZE(ip));
619 * We're freeing a symlink that has some
620 * blocks allocated to it. Free the
621 * blocks here. We know that we've got
622 * either 1 or 2 extents and that we can
623 * free them all in one bunmapi call.
625 ASSERT(ip->i_d.di_nextents > 0 && ip->i_d.di_nextents <= 2);
628 * Lock the inode, fix the size, and join it to the transaction.
629 * Hold it so in the normal path, we still have it locked for
630 * the second transaction. In the error paths we need it
631 * held so the cancel won't rele it, see below.
633 size = (int)ip->i_d.di_size;
635 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
637 * Find the block(s) so we can inval and unmap them.
640 xfs_bmap_init(&free_list, &first_block);
641 nmaps = ARRAY_SIZE(mval);
642 error = xfs_bmapi_read(ip, 0, xfs_symlink_blocks(mp, size),
647 * Invalidate the block(s). No validation is done.
649 for (i = 0; i < nmaps; i++) {
650 bp = xfs_trans_get_buf(tp, mp->m_ddev_targp,
651 XFS_FSB_TO_DADDR(mp, mval[i].br_startblock),
652 XFS_FSB_TO_BB(mp, mval[i].br_blockcount), 0);
657 xfs_trans_binval(tp, bp);
660 * Unmap the dead block(s) to the free_list.
662 if ((error = xfs_bunmapi(tp, ip, 0, size, XFS_BMAPI_METADATA, nmaps,
663 &first_block, &free_list, &done)))
667 * Commit the first transaction. This logs the EFI and the inode.
669 if ((error = xfs_bmap_finish(&tp, &free_list, &committed)))
672 * The transaction must have been committed, since there were
673 * actually extents freed by xfs_bunmapi. See xfs_bmap_finish.
674 * The new tp has the extent freeing and EFDs.
678 * The first xact was committed, so add the inode to the new one.
679 * Mark it dirty so it will be logged and moved forward in the log as
680 * part of every commit.
682 xfs_trans_ijoin(tp, ip, 0);
683 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
685 * Get a new, empty transaction to return to our caller.
687 ntp = xfs_trans_dup(tp);
689 * Commit the transaction containing extent freeing and EFDs.
690 * If we get an error on the commit here or on the reserve below,
691 * we need to unlock the inode since the new transaction doesn't
692 * have the inode attached.
694 error = xfs_trans_commit(tp, 0);
697 ASSERT(XFS_FORCED_SHUTDOWN(mp));
701 * transaction commit worked ok so we can drop the extra ticket
702 * reference that we gained in xfs_trans_dup()
704 xfs_log_ticket_put(tp->t_ticket);
707 * Remove the memory for extent descriptions (just bookkeeping).
709 if (ip->i_df.if_bytes)
710 xfs_idata_realloc(ip, -ip->i_df.if_bytes, XFS_DATA_FORK);
711 ASSERT(ip->i_df.if_bytes == 0);
713 * Put an itruncate log reservation in the new transaction
716 if ((error = xfs_trans_reserve(tp, 0, XFS_ITRUNCATE_LOG_RES(mp), 0,
717 XFS_TRANS_PERM_LOG_RES, XFS_ITRUNCATE_LOG_COUNT))) {
718 ASSERT(XFS_FORCED_SHUTDOWN(mp));
722 xfs_trans_ijoin(tp, ip, 0);
727 xfs_bmap_cancel(&free_list);