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_format.h"
24 #include "xfs_trans.h"
27 #include "xfs_mount.h"
28 #include "xfs_da_btree.h"
29 #include "xfs_dir2_format.h"
31 #include "xfs_bmap_btree.h"
32 #include "xfs_ialloc_btree.h"
33 #include "xfs_dinode.h"
34 #include "xfs_inode.h"
35 #include "xfs_ialloc.h"
36 #include "xfs_alloc.h"
38 #include "xfs_error.h"
39 #include "xfs_quota.h"
40 #include "xfs_utils.h"
41 #include "xfs_trans_space.h"
42 #include "xfs_trace.h"
43 #include "xfs_symlink.h"
45 /* ----- Kernel only functions below ----- */
51 struct xfs_mount *mp = ip->i_mount;
52 struct xfs_bmbt_irec mval[XFS_SYMLINK_MAPS];
56 int pathlen = ip->i_d.di_size;
57 int nmaps = XFS_SYMLINK_MAPS;
64 fsblocks = xfs_symlink_blocks(mp, pathlen);
65 error = xfs_bmapi_read(ip, 0, fsblocks, mval, &nmaps, 0);
70 for (n = 0; n < nmaps; n++) {
71 d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock);
72 byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);
74 bp = xfs_buf_read(mp->m_ddev_targp, d, BTOBB(byte_cnt), 0,
75 &xfs_symlink_buf_ops);
77 return XFS_ERROR(ENOMEM);
80 xfs_buf_ioerror_alert(bp, __func__);
84 byte_cnt = XFS_SYMLINK_BUF_SPACE(mp, byte_cnt);
85 if (pathlen < byte_cnt)
88 cur_chunk = bp->b_addr;
89 if (xfs_sb_version_hascrc(&mp->m_sb)) {
90 if (!xfs_symlink_hdr_ok(mp, ip->i_ino, offset,
94 "symlink header does not match required off/len/owner (0x%x/Ox%x,0x%llx)",
95 offset, byte_cnt, ip->i_ino);
101 cur_chunk += sizeof(struct xfs_dsymlink_hdr);
104 memcpy(link + offset, bp->b_addr, byte_cnt);
111 ASSERT(pathlen == 0);
113 link[ip->i_d.di_size] = '\0';
122 struct xfs_inode *ip,
125 struct xfs_mount *mp = ip->i_mount;
129 trace_xfs_readlink(ip);
131 if (XFS_FORCED_SHUTDOWN(mp))
132 return XFS_ERROR(EIO);
134 xfs_ilock(ip, XFS_ILOCK_SHARED);
136 pathlen = ip->i_d.di_size;
140 if (pathlen < 0 || pathlen > MAXPATHLEN) {
141 xfs_alert(mp, "%s: inode (%llu) bad symlink length (%lld)",
142 __func__, (unsigned long long) ip->i_ino,
143 (long long) pathlen);
145 error = XFS_ERROR(EFSCORRUPTED);
150 if (ip->i_df.if_flags & XFS_IFINLINE) {
151 memcpy(link, ip->i_df.if_u1.if_data, pathlen);
152 link[pathlen] = '\0';
154 error = xfs_readlink_bmap(ip, link);
158 xfs_iunlock(ip, XFS_ILOCK_SHARED);
164 struct xfs_inode *dp,
165 struct xfs_name *link_name,
166 const char *target_path,
168 struct xfs_inode **ipp)
170 struct xfs_mount *mp = dp->i_mount;
171 struct xfs_trans *tp = NULL;
172 struct xfs_inode *ip = NULL;
175 struct xfs_bmap_free free_list;
176 xfs_fsblock_t first_block;
177 bool unlock_dp_on_error = false;
180 xfs_fileoff_t first_fsb;
181 xfs_filblks_t fs_blocks;
183 struct xfs_bmbt_irec mval[XFS_SYMLINK_MAPS];
185 const char *cur_chunk;
190 struct xfs_dquot *udqp = NULL;
191 struct xfs_dquot *gdqp = NULL;
192 struct xfs_dquot *pdqp = NULL;
197 trace_xfs_symlink(dp, link_name);
199 if (XFS_FORCED_SHUTDOWN(mp))
200 return XFS_ERROR(EIO);
203 * Check component lengths of the target path name.
205 pathlen = strlen(target_path);
206 if (pathlen >= MAXPATHLEN) /* total string too long */
207 return XFS_ERROR(ENAMETOOLONG);
210 if (dp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT)
211 prid = xfs_get_projid(dp);
213 prid = XFS_PROJID_DEFAULT;
216 * Make sure that we have allocated dquot(s) on disk.
218 error = xfs_qm_vop_dqalloc(dp, current_fsuid(), current_fsgid(), prid,
219 XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT, &udqp, &gdqp, &pdqp);
223 tp = xfs_trans_alloc(mp, XFS_TRANS_SYMLINK);
224 cancel_flags = XFS_TRANS_RELEASE_LOG_RES;
226 * The symlink will fit into the inode data fork?
227 * There can't be any attributes so we get the whole variable part.
229 if (pathlen <= XFS_LITINO(mp, dp->i_d.di_version))
232 fs_blocks = xfs_symlink_blocks(mp, pathlen);
233 resblks = XFS_SYMLINK_SPACE_RES(mp, link_name->len, fs_blocks);
234 error = xfs_trans_reserve(tp, resblks, XFS_SYMLINK_LOG_RES(mp), 0,
235 XFS_TRANS_PERM_LOG_RES, XFS_SYMLINK_LOG_COUNT);
236 if (error == ENOSPC && fs_blocks == 0) {
238 error = xfs_trans_reserve(tp, 0, XFS_SYMLINK_LOG_RES(mp), 0,
239 XFS_TRANS_PERM_LOG_RES, XFS_SYMLINK_LOG_COUNT);
246 xfs_ilock(dp, XFS_ILOCK_EXCL | XFS_ILOCK_PARENT);
247 unlock_dp_on_error = true;
250 * Check whether the directory allows new symlinks or not.
252 if (dp->i_d.di_flags & XFS_DIFLAG_NOSYMLINKS) {
253 error = XFS_ERROR(EPERM);
258 * Reserve disk quota : blocks and inode.
260 error = xfs_trans_reserve_quota(tp, mp, udqp, gdqp,
261 pdqp, resblks, 1, 0);
266 * Check for ability to enter directory entry, if no space reserved.
268 error = xfs_dir_canenter(tp, dp, link_name, resblks);
272 * Initialize the bmap freelist prior to calling either
273 * bmapi or the directory create code.
275 xfs_bmap_init(&free_list, &first_block);
278 * Allocate an inode for the symlink.
280 error = xfs_dir_ialloc(&tp, dp, S_IFLNK | (mode & ~S_IFMT), 1, 0,
281 prid, resblks > 0, &ip, NULL);
289 * An error after we've joined dp to the transaction will result in the
290 * transaction cancel unlocking dp so don't do it explicitly in the
293 xfs_trans_ijoin(tp, dp, XFS_ILOCK_EXCL);
294 unlock_dp_on_error = false;
297 * Also attach the dquot(s) to it, if applicable.
299 xfs_qm_vop_create_dqattach(tp, ip, udqp, gdqp, pdqp);
302 resblks -= XFS_IALLOC_SPACE_RES(mp);
304 * If the symlink will fit into the inode, write it inline.
306 if (pathlen <= XFS_IFORK_DSIZE(ip)) {
307 xfs_idata_realloc(ip, pathlen, XFS_DATA_FORK);
308 memcpy(ip->i_df.if_u1.if_data, target_path, pathlen);
309 ip->i_d.di_size = pathlen;
312 * The inode was initially created in extent format.
314 ip->i_df.if_flags &= ~(XFS_IFEXTENTS | XFS_IFBROOT);
315 ip->i_df.if_flags |= XFS_IFINLINE;
317 ip->i_d.di_format = XFS_DINODE_FMT_LOCAL;
318 xfs_trans_log_inode(tp, ip, XFS_ILOG_DDATA | XFS_ILOG_CORE);
324 nmaps = XFS_SYMLINK_MAPS;
326 error = xfs_bmapi_write(tp, ip, first_fsb, fs_blocks,
327 XFS_BMAPI_METADATA, &first_block, resblks,
328 mval, &nmaps, &free_list);
333 resblks -= fs_blocks;
334 ip->i_d.di_size = pathlen;
335 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
337 cur_chunk = target_path;
339 for (n = 0; n < nmaps; n++) {
342 d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock);
343 byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);
344 bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d,
350 bp->b_ops = &xfs_symlink_buf_ops;
352 byte_cnt = XFS_SYMLINK_BUF_SPACE(mp, byte_cnt);
353 byte_cnt = min(byte_cnt, pathlen);
356 buf += xfs_symlink_hdr_set(mp, ip->i_ino, offset,
359 memcpy(buf, cur_chunk, byte_cnt);
361 cur_chunk += byte_cnt;
365 xfs_trans_log_buf(tp, bp, 0, (buf + byte_cnt - 1) -
368 ASSERT(pathlen == 0);
372 * Create the directory entry for the symlink.
374 error = xfs_dir_createname(tp, dp, link_name, ip->i_ino,
375 &first_block, &free_list, resblks);
378 xfs_trans_ichgtime(tp, dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
379 xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
382 * If this is a synchronous mount, make sure that the
383 * symlink transaction goes to disk before returning to
386 if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC)) {
387 xfs_trans_set_sync(tp);
390 error = xfs_bmap_finish(&tp, &free_list, &committed);
394 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
405 xfs_bmap_cancel(&free_list);
406 cancel_flags |= XFS_TRANS_ABORT;
408 xfs_trans_cancel(tp, cancel_flags);
413 if (unlock_dp_on_error)
414 xfs_iunlock(dp, XFS_ILOCK_EXCL);
420 * Free a symlink that has blocks associated with it.
423 xfs_inactive_symlink_rmt(
431 xfs_fsblock_t first_block;
432 xfs_bmap_free_t free_list;
435 xfs_bmbt_irec_t mval[XFS_SYMLINK_MAPS];
443 ASSERT(ip->i_df.if_flags & XFS_IFEXTENTS);
445 * We're freeing a symlink that has some
446 * blocks allocated to it. Free the
447 * blocks here. We know that we've got
448 * either 1 or 2 extents and that we can
449 * free them all in one bunmapi call.
451 ASSERT(ip->i_d.di_nextents > 0 && ip->i_d.di_nextents <= 2);
454 * Lock the inode, fix the size, and join it to the transaction.
455 * Hold it so in the normal path, we still have it locked for
456 * the second transaction. In the error paths we need it
457 * held so the cancel won't rele it, see below.
459 size = (int)ip->i_d.di_size;
461 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
463 * Find the block(s) so we can inval and unmap them.
466 xfs_bmap_init(&free_list, &first_block);
467 nmaps = ARRAY_SIZE(mval);
468 error = xfs_bmapi_read(ip, 0, xfs_symlink_blocks(mp, size),
473 * Invalidate the block(s). No validation is done.
475 for (i = 0; i < nmaps; i++) {
476 bp = xfs_trans_get_buf(tp, mp->m_ddev_targp,
477 XFS_FSB_TO_DADDR(mp, mval[i].br_startblock),
478 XFS_FSB_TO_BB(mp, mval[i].br_blockcount), 0);
483 xfs_trans_binval(tp, bp);
486 * Unmap the dead block(s) to the free_list.
488 if ((error = xfs_bunmapi(tp, ip, 0, size, XFS_BMAPI_METADATA, nmaps,
489 &first_block, &free_list, &done)))
493 * Commit the first transaction. This logs the EFI and the inode.
495 if ((error = xfs_bmap_finish(&tp, &free_list, &committed)))
498 * The transaction must have been committed, since there were
499 * actually extents freed by xfs_bunmapi. See xfs_bmap_finish.
500 * The new tp has the extent freeing and EFDs.
504 * The first xact was committed, so add the inode to the new one.
505 * Mark it dirty so it will be logged and moved forward in the log as
506 * part of every commit.
508 xfs_trans_ijoin(tp, ip, 0);
509 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
511 * Get a new, empty transaction to return to our caller.
513 ntp = xfs_trans_dup(tp);
515 * Commit the transaction containing extent freeing and EFDs.
516 * If we get an error on the commit here or on the reserve below,
517 * we need to unlock the inode since the new transaction doesn't
518 * have the inode attached.
520 error = xfs_trans_commit(tp, 0);
523 ASSERT(XFS_FORCED_SHUTDOWN(mp));
527 * transaction commit worked ok so we can drop the extra ticket
528 * reference that we gained in xfs_trans_dup()
530 xfs_log_ticket_put(tp->t_ticket);
533 * Remove the memory for extent descriptions (just bookkeeping).
535 if (ip->i_df.if_bytes)
536 xfs_idata_realloc(ip, -ip->i_df.if_bytes, XFS_DATA_FORK);
537 ASSERT(ip->i_df.if_bytes == 0);
539 * Put an itruncate log reservation in the new transaction
542 if ((error = xfs_trans_reserve(tp, 0, XFS_ITRUNCATE_LOG_RES(mp), 0,
543 XFS_TRANS_PERM_LOG_RES, XFS_ITRUNCATE_LOG_COUNT))) {
544 ASSERT(XFS_FORCED_SHUTDOWN(mp));
548 xfs_trans_ijoin(tp, ip, 0);
553 xfs_bmap_cancel(&free_list);
559 * xfs_inactive_symlink - free a symlink
562 xfs_inactive_symlink(
563 struct xfs_inode *ip,
564 struct xfs_trans **tp)
566 struct xfs_mount *mp = ip->i_mount;
569 trace_xfs_inactive_symlink(ip);
571 ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
573 if (XFS_FORCED_SHUTDOWN(mp))
574 return XFS_ERROR(EIO);
577 * Zero length symlinks _can_ exist.
579 pathlen = (int)ip->i_d.di_size;
583 if (pathlen < 0 || pathlen > MAXPATHLEN) {
584 xfs_alert(mp, "%s: inode (0x%llx) bad symlink length (%d)",
585 __func__, (unsigned long long)ip->i_ino, pathlen);
587 return XFS_ERROR(EFSCORRUPTED);
590 if (ip->i_df.if_flags & XFS_IFINLINE) {
591 if (ip->i_df.if_bytes > 0)
592 xfs_idata_realloc(ip, -(ip->i_df.if_bytes),
594 ASSERT(ip->i_df.if_bytes == 0);
598 /* remove the remote symlink */
599 return xfs_inactive_symlink_rmt(ip, tp);