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
20 #include "xfs_shared.h"
22 #include "xfs_format.h"
23 #include "xfs_log_format.h"
24 #include "xfs_trans_resv.h"
26 #include "xfs_mount.h"
27 #include "xfs_da_format.h"
28 #include "xfs_da_btree.h"
30 #include "xfs_inode.h"
31 #include "xfs_ialloc.h"
32 #include "xfs_alloc.h"
34 #include "xfs_bmap_btree.h"
35 #include "xfs_bmap_util.h"
36 #include "xfs_error.h"
37 #include "xfs_quota.h"
38 #include "xfs_trans_space.h"
39 #include "xfs_trace.h"
40 #include "xfs_symlink.h"
41 #include "xfs_trans.h"
44 /* ----- Kernel only functions below ----- */
50 struct xfs_mount *mp = ip->i_mount;
51 struct xfs_bmbt_irec mval[XFS_SYMLINK_MAPS];
55 int pathlen = ip->i_d.di_size;
56 int nmaps = XFS_SYMLINK_MAPS;
63 fsblocks = xfs_symlink_blocks(mp, pathlen);
64 error = xfs_bmapi_read(ip, 0, fsblocks, mval, &nmaps, 0);
69 for (n = 0; n < nmaps; n++) {
70 d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock);
71 byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);
73 bp = xfs_buf_read(mp->m_ddev_targp, d, BTOBB(byte_cnt), 0,
74 &xfs_symlink_buf_ops);
79 xfs_buf_ioerror_alert(bp, __func__);
82 /* bad CRC means corrupted metadata */
83 if (error == -EFSBADCRC)
84 error = -EFSCORRUPTED;
87 byte_cnt = XFS_SYMLINK_BUF_SPACE(mp, byte_cnt);
88 if (pathlen < byte_cnt)
91 cur_chunk = bp->b_addr;
92 if (xfs_sb_version_hascrc(&mp->m_sb)) {
93 if (!xfs_symlink_hdr_ok(ip->i_ino, offset,
95 error = -EFSCORRUPTED;
97 "symlink header does not match required off/len/owner (0x%x/Ox%x,0x%llx)",
98 offset, byte_cnt, ip->i_ino);
104 cur_chunk += sizeof(struct xfs_dsymlink_hdr);
107 memcpy(link + offset, cur_chunk, byte_cnt);
114 ASSERT(pathlen == 0);
116 link[ip->i_d.di_size] = '\0';
125 struct xfs_inode *ip,
128 struct xfs_mount *mp = ip->i_mount;
132 trace_xfs_readlink(ip);
134 if (XFS_FORCED_SHUTDOWN(mp))
137 xfs_ilock(ip, XFS_ILOCK_SHARED);
139 pathlen = ip->i_d.di_size;
143 if (pathlen < 0 || pathlen > MAXPATHLEN) {
144 xfs_alert(mp, "%s: inode (%llu) bad symlink length (%lld)",
145 __func__, (unsigned long long) ip->i_ino,
146 (long long) pathlen);
148 error = -EFSCORRUPTED;
153 if (ip->i_df.if_flags & XFS_IFINLINE) {
154 memcpy(link, ip->i_df.if_u1.if_data, pathlen);
155 link[pathlen] = '\0';
157 error = xfs_readlink_bmap(ip, link);
161 xfs_iunlock(ip, XFS_ILOCK_SHARED);
167 struct xfs_inode *dp,
168 struct xfs_name *link_name,
169 const char *target_path,
171 struct xfs_inode **ipp)
173 struct xfs_mount *mp = dp->i_mount;
174 struct xfs_trans *tp = NULL;
175 struct xfs_inode *ip = NULL;
178 struct xfs_bmap_free free_list;
179 xfs_fsblock_t first_block;
180 bool unlock_dp_on_error = false;
181 xfs_fileoff_t first_fsb;
182 xfs_filblks_t fs_blocks;
184 struct xfs_bmbt_irec mval[XFS_SYMLINK_MAPS];
186 const char *cur_chunk;
191 struct xfs_dquot *udqp = NULL;
192 struct xfs_dquot *gdqp = NULL;
193 struct xfs_dquot *pdqp = NULL;
198 trace_xfs_symlink(dp, link_name);
200 if (XFS_FORCED_SHUTDOWN(mp))
204 * Check component lengths of the target path name.
206 pathlen = strlen(target_path);
207 if (pathlen >= MAXPATHLEN) /* total string too long */
208 return -ENAMETOOLONG;
211 prid = xfs_get_initial_prid(dp);
214 * Make sure that we have allocated dquot(s) on disk.
216 error = xfs_qm_vop_dqalloc(dp,
217 xfs_kuid_to_uid(current_fsuid()),
218 xfs_kgid_to_gid(current_fsgid()), prid,
219 XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT,
220 &udqp, &gdqp, &pdqp);
224 tp = xfs_trans_alloc(mp, XFS_TRANS_SYMLINK);
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, &M_RES(mp)->tr_symlink, resblks, 0);
235 if (error == -ENOSPC && fs_blocks == 0) {
237 error = xfs_trans_reserve(tp, &M_RES(mp)->tr_symlink, 0, 0);
240 goto out_trans_cancel;
242 xfs_ilock(dp, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL |
243 XFS_IOLOCK_PARENT | XFS_ILOCK_PARENT);
244 unlock_dp_on_error = true;
247 * Check whether the directory allows new symlinks or not.
249 if (dp->i_d.di_flags & XFS_DIFLAG_NOSYMLINKS) {
251 goto out_trans_cancel;
255 * Reserve disk quota : blocks and inode.
257 error = xfs_trans_reserve_quota(tp, mp, udqp, gdqp,
258 pdqp, resblks, 1, 0);
260 goto out_trans_cancel;
263 * Check for ability to enter directory entry, if no space reserved.
266 error = xfs_dir_canenter(tp, dp, link_name);
268 goto out_trans_cancel;
271 * Initialize the bmap freelist prior to calling either
272 * bmapi or the directory create code.
274 xfs_bmap_init(&free_list, &first_block);
277 * Allocate an inode for the symlink.
279 error = xfs_dir_ialloc(&tp, dp, S_IFLNK | (mode & ~S_IFMT), 1, 0,
280 prid, resblks > 0, &ip, NULL);
282 goto out_trans_cancel;
285 * Now we join the directory inode to the transaction. We do not do it
286 * earlier because xfs_dir_ialloc might commit the previous transaction
287 * (and release all the locks). An error from here on will result in
288 * the transaction cancel unlocking dp so don't do it explicitly in the
291 xfs_trans_ijoin(tp, dp, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL);
292 unlock_dp_on_error = false;
295 * Also attach the dquot(s) to it, if applicable.
297 xfs_qm_vop_create_dqattach(tp, ip, udqp, gdqp, pdqp);
300 resblks -= XFS_IALLOC_SPACE_RES(mp);
302 * If the symlink will fit into the inode, write it inline.
304 if (pathlen <= XFS_IFORK_DSIZE(ip)) {
305 xfs_idata_realloc(ip, pathlen, XFS_DATA_FORK);
306 memcpy(ip->i_df.if_u1.if_data, target_path, pathlen);
307 ip->i_d.di_size = pathlen;
310 * The inode was initially created in extent format.
312 ip->i_df.if_flags &= ~(XFS_IFEXTENTS | XFS_IFBROOT);
313 ip->i_df.if_flags |= XFS_IFINLINE;
315 ip->i_d.di_format = XFS_DINODE_FMT_LOCAL;
316 xfs_trans_log_inode(tp, ip, XFS_ILOG_DDATA | XFS_ILOG_CORE);
322 nmaps = XFS_SYMLINK_MAPS;
324 error = xfs_bmapi_write(tp, ip, first_fsb, fs_blocks,
325 XFS_BMAPI_METADATA, &first_block, resblks,
326 mval, &nmaps, &free_list);
328 goto out_bmap_cancel;
331 resblks -= fs_blocks;
332 ip->i_d.di_size = pathlen;
333 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
335 cur_chunk = target_path;
337 for (n = 0; n < nmaps; n++) {
340 d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock);
341 byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);
342 bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d,
346 goto out_bmap_cancel;
348 bp->b_ops = &xfs_symlink_buf_ops;
350 byte_cnt = XFS_SYMLINK_BUF_SPACE(mp, byte_cnt);
351 byte_cnt = min(byte_cnt, pathlen);
354 buf += xfs_symlink_hdr_set(mp, ip->i_ino, offset,
357 memcpy(buf, cur_chunk, byte_cnt);
359 cur_chunk += byte_cnt;
363 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_SYMLINK_BUF);
364 xfs_trans_log_buf(tp, bp, 0, (buf + byte_cnt - 1) -
367 ASSERT(pathlen == 0);
371 * Create the directory entry for the symlink.
373 error = xfs_dir_createname(tp, dp, link_name, ip->i_ino,
374 &first_block, &free_list, resblks);
376 goto out_bmap_cancel;
377 xfs_trans_ichgtime(tp, dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
378 xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
381 * If this is a synchronous mount, make sure that the
382 * symlink transaction goes to disk before returning to
385 if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC)) {
386 xfs_trans_set_sync(tp);
389 error = xfs_bmap_finish(&tp, &free_list, NULL);
391 goto out_bmap_cancel;
393 error = xfs_trans_commit(tp);
395 goto out_release_inode;
405 xfs_bmap_cancel(&free_list);
407 xfs_trans_cancel(tp);
410 * Wait until after the current transaction is aborted to finish the
411 * setup of the inode and release the inode. This prevents recursive
412 * transactions and deadlocks from xfs_inactive.
415 xfs_finish_inode_setup(ip);
423 if (unlock_dp_on_error)
424 xfs_iunlock(dp, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL);
429 * Free a symlink that has blocks associated with it.
432 xfs_inactive_symlink_rmt(
433 struct xfs_inode *ip)
438 xfs_fsblock_t first_block;
439 xfs_bmap_free_t free_list;
442 xfs_bmbt_irec_t mval[XFS_SYMLINK_MAPS];
448 ASSERT(ip->i_df.if_flags & XFS_IFEXTENTS);
450 * We're freeing a symlink that has some
451 * blocks allocated to it. Free the
452 * blocks here. We know that we've got
453 * either 1 or 2 extents and that we can
454 * free them all in one bunmapi call.
456 ASSERT(ip->i_d.di_nextents > 0 && ip->i_d.di_nextents <= 2);
458 tp = xfs_trans_alloc(mp, XFS_TRANS_INACTIVE);
459 error = xfs_trans_reserve(tp, &M_RES(mp)->tr_itruncate, 0, 0);
461 xfs_trans_cancel(tp);
465 xfs_ilock(ip, XFS_ILOCK_EXCL);
466 xfs_trans_ijoin(tp, ip, 0);
469 * Lock the inode, fix the size, and join it to the transaction.
470 * Hold it so in the normal path, we still have it locked for
471 * the second transaction. In the error paths we need it
472 * held so the cancel won't rele it, see below.
474 size = (int)ip->i_d.di_size;
476 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
478 * Find the block(s) so we can inval and unmap them.
481 xfs_bmap_init(&free_list, &first_block);
482 nmaps = ARRAY_SIZE(mval);
483 error = xfs_bmapi_read(ip, 0, xfs_symlink_blocks(mp, size),
486 goto error_trans_cancel;
488 * Invalidate the block(s). No validation is done.
490 for (i = 0; i < nmaps; i++) {
491 bp = xfs_trans_get_buf(tp, mp->m_ddev_targp,
492 XFS_FSB_TO_DADDR(mp, mval[i].br_startblock),
493 XFS_FSB_TO_BB(mp, mval[i].br_blockcount), 0);
496 goto error_bmap_cancel;
498 xfs_trans_binval(tp, bp);
501 * Unmap the dead block(s) to the free_list.
503 error = xfs_bunmapi(tp, ip, 0, size, 0, nmaps,
504 &first_block, &free_list, &done);
506 goto error_bmap_cancel;
509 * Commit the first transaction. This logs the EFI and the inode.
511 error = xfs_bmap_finish(&tp, &free_list, ip);
513 goto error_bmap_cancel;
515 * The first xact was committed, so add the inode to the new one.
516 * Mark it dirty so it will be logged and moved forward in the log as
517 * part of every commit.
519 xfs_trans_ijoin(tp, ip, 0);
520 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
522 * Commit the transaction containing extent freeing and EFDs.
524 error = xfs_trans_commit(tp);
526 ASSERT(XFS_FORCED_SHUTDOWN(mp));
531 * Remove the memory for extent descriptions (just bookkeeping).
533 if (ip->i_df.if_bytes)
534 xfs_idata_realloc(ip, -ip->i_df.if_bytes, XFS_DATA_FORK);
535 ASSERT(ip->i_df.if_bytes == 0);
537 xfs_iunlock(ip, XFS_ILOCK_EXCL);
541 xfs_bmap_cancel(&free_list);
543 xfs_trans_cancel(tp);
545 xfs_iunlock(ip, XFS_ILOCK_EXCL);
550 * xfs_inactive_symlink - free a symlink
553 xfs_inactive_symlink(
554 struct xfs_inode *ip)
556 struct xfs_mount *mp = ip->i_mount;
559 trace_xfs_inactive_symlink(ip);
561 if (XFS_FORCED_SHUTDOWN(mp))
564 xfs_ilock(ip, XFS_ILOCK_EXCL);
567 * Zero length symlinks _can_ exist.
569 pathlen = (int)ip->i_d.di_size;
571 xfs_iunlock(ip, XFS_ILOCK_EXCL);
575 if (pathlen < 0 || pathlen > MAXPATHLEN) {
576 xfs_alert(mp, "%s: inode (0x%llx) bad symlink length (%d)",
577 __func__, (unsigned long long)ip->i_ino, pathlen);
578 xfs_iunlock(ip, XFS_ILOCK_EXCL);
580 return -EFSCORRUPTED;
583 if (ip->i_df.if_flags & XFS_IFINLINE) {
584 if (ip->i_df.if_bytes > 0)
585 xfs_idata_realloc(ip, -(ip->i_df.if_bytes),
587 xfs_iunlock(ip, XFS_ILOCK_EXCL);
588 ASSERT(ip->i_df.if_bytes == 0);
592 xfs_iunlock(ip, XFS_ILOCK_EXCL);
594 /* remove the remote symlink */
595 return xfs_inactive_symlink_rmt(ip);