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"
29 #include "xfs_defer.h"
31 #include "xfs_inode.h"
32 #include "xfs_ialloc.h"
33 #include "xfs_alloc.h"
35 #include "xfs_bmap_btree.h"
36 #include "xfs_bmap_util.h"
37 #include "xfs_error.h"
38 #include "xfs_quota.h"
39 #include "xfs_trans_space.h"
40 #include "xfs_trace.h"
41 #include "xfs_symlink.h"
42 #include "xfs_trans.h"
45 /* ----- Kernel only functions below ----- */
47 xfs_readlink_bmap_ilocked(
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 ASSERT(xfs_isilocked(ip, XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
66 fsblocks = xfs_symlink_blocks(mp, pathlen);
67 error = xfs_bmapi_read(ip, 0, fsblocks, mval, &nmaps, 0);
72 for (n = 0; n < nmaps; n++) {
73 d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock);
74 byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);
76 bp = xfs_buf_read(mp->m_ddev_targp, d, BTOBB(byte_cnt), 0,
77 &xfs_symlink_buf_ops);
82 xfs_buf_ioerror_alert(bp, __func__);
85 /* bad CRC means corrupted metadata */
86 if (error == -EFSBADCRC)
87 error = -EFSCORRUPTED;
90 byte_cnt = XFS_SYMLINK_BUF_SPACE(mp, byte_cnt);
91 if (pathlen < byte_cnt)
94 cur_chunk = bp->b_addr;
95 if (xfs_sb_version_hascrc(&mp->m_sb)) {
96 if (!xfs_symlink_hdr_ok(ip->i_ino, offset,
98 error = -EFSCORRUPTED;
100 "symlink header does not match required off/len/owner (0x%x/Ox%x,0x%llx)",
101 offset, byte_cnt, ip->i_ino);
107 cur_chunk += sizeof(struct xfs_dsymlink_hdr);
110 memcpy(link + offset, cur_chunk, byte_cnt);
117 ASSERT(pathlen == 0);
119 link[ip->i_d.di_size] = '\0';
128 struct xfs_inode *ip,
131 struct xfs_mount *mp = ip->i_mount;
135 trace_xfs_readlink(ip);
137 ASSERT(!(ip->i_df.if_flags & XFS_IFINLINE));
139 if (XFS_FORCED_SHUTDOWN(mp))
142 xfs_ilock(ip, XFS_ILOCK_SHARED);
144 pathlen = ip->i_d.di_size;
148 if (pathlen < 0 || pathlen > XFS_SYMLINK_MAXLEN) {
149 xfs_alert(mp, "%s: inode (%llu) bad symlink length (%lld)",
150 __func__, (unsigned long long) ip->i_ino,
151 (long long) pathlen);
153 error = -EFSCORRUPTED;
158 error = xfs_readlink_bmap_ilocked(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_defer_ops dfops;
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 >= XFS_SYMLINK_MAXLEN) /* 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);
225 * The symlink will fit into the inode data fork?
226 * There can't be any attributes so we get the whole variable part.
228 if (pathlen <= XFS_LITINO(mp, dp->i_d.di_version))
231 fs_blocks = xfs_symlink_blocks(mp, pathlen);
232 resblks = XFS_SYMLINK_SPACE_RES(mp, link_name->len, fs_blocks);
234 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_symlink, resblks, 0, 0, &tp);
236 goto out_release_inode;
238 xfs_ilock(dp, XFS_ILOCK_EXCL | XFS_ILOCK_PARENT);
239 unlock_dp_on_error = true;
242 * Check whether the directory allows new symlinks or not.
244 if (dp->i_d.di_flags & XFS_DIFLAG_NOSYMLINKS) {
246 goto out_trans_cancel;
250 * Reserve disk quota : blocks and inode.
252 error = xfs_trans_reserve_quota(tp, mp, udqp, gdqp,
253 pdqp, resblks, 1, 0);
255 goto out_trans_cancel;
258 * Initialize the bmap freelist prior to calling either
259 * bmapi or the directory create code.
261 xfs_defer_init(&dfops, &first_block);
264 * Allocate an inode for the symlink.
266 error = xfs_dir_ialloc(&tp, dp, S_IFLNK | (mode & ~S_IFMT), 1, 0,
269 goto out_trans_cancel;
272 * Now we join the directory inode to the transaction. We do not do it
273 * earlier because xfs_dir_ialloc might commit the previous transaction
274 * (and release all the locks). An error from here on will result in
275 * the transaction cancel unlocking dp so don't do it explicitly in the
278 xfs_trans_ijoin(tp, dp, XFS_ILOCK_EXCL);
279 unlock_dp_on_error = false;
282 * Also attach the dquot(s) to it, if applicable.
284 xfs_qm_vop_create_dqattach(tp, ip, udqp, gdqp, pdqp);
287 resblks -= XFS_IALLOC_SPACE_RES(mp);
289 * If the symlink will fit into the inode, write it inline.
291 if (pathlen <= XFS_IFORK_DSIZE(ip)) {
292 xfs_init_local_fork(ip, XFS_DATA_FORK, target_path, pathlen);
294 ip->i_d.di_size = pathlen;
295 ip->i_d.di_format = XFS_DINODE_FMT_LOCAL;
296 xfs_trans_log_inode(tp, ip, XFS_ILOG_DDATA | XFS_ILOG_CORE);
301 nmaps = XFS_SYMLINK_MAPS;
303 error = xfs_bmapi_write(tp, ip, first_fsb, fs_blocks,
304 XFS_BMAPI_METADATA, &first_block, resblks,
305 mval, &nmaps, &dfops);
307 goto out_bmap_cancel;
310 resblks -= fs_blocks;
311 ip->i_d.di_size = pathlen;
312 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
314 cur_chunk = target_path;
316 for (n = 0; n < nmaps; n++) {
319 d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock);
320 byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);
321 bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d,
325 goto out_bmap_cancel;
327 bp->b_ops = &xfs_symlink_buf_ops;
329 byte_cnt = XFS_SYMLINK_BUF_SPACE(mp, byte_cnt);
330 byte_cnt = min(byte_cnt, pathlen);
333 buf += xfs_symlink_hdr_set(mp, ip->i_ino, offset,
336 memcpy(buf, cur_chunk, byte_cnt);
338 cur_chunk += byte_cnt;
342 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_SYMLINK_BUF);
343 xfs_trans_log_buf(tp, bp, 0, (buf + byte_cnt - 1) -
346 ASSERT(pathlen == 0);
350 * Create the directory entry for the symlink.
352 error = xfs_dir_createname(tp, dp, link_name, ip->i_ino,
353 &first_block, &dfops, resblks);
355 goto out_bmap_cancel;
356 xfs_trans_ichgtime(tp, dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
357 xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
360 * If this is a synchronous mount, make sure that the
361 * symlink transaction goes to disk before returning to
364 if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC)) {
365 xfs_trans_set_sync(tp);
368 error = xfs_defer_finish(&tp, &dfops);
370 goto out_bmap_cancel;
372 error = xfs_trans_commit(tp);
374 goto out_release_inode;
384 xfs_defer_cancel(&dfops);
386 xfs_trans_cancel(tp);
389 * Wait until after the current transaction is aborted to finish the
390 * setup of the inode and release the inode. This prevents recursive
391 * transactions and deadlocks from xfs_inactive.
394 xfs_finish_inode_setup(ip);
402 if (unlock_dp_on_error)
403 xfs_iunlock(dp, XFS_ILOCK_EXCL);
408 * Free a symlink that has blocks associated with it.
411 xfs_inactive_symlink_rmt(
412 struct xfs_inode *ip)
417 xfs_fsblock_t first_block;
418 struct xfs_defer_ops dfops;
421 xfs_bmbt_irec_t mval[XFS_SYMLINK_MAPS];
427 ASSERT(ip->i_df.if_flags & XFS_IFEXTENTS);
429 * We're freeing a symlink that has some
430 * blocks allocated to it. Free the
431 * blocks here. We know that we've got
432 * either 1 or 2 extents and that we can
433 * free them all in one bunmapi call.
435 ASSERT(ip->i_d.di_nextents > 0 && ip->i_d.di_nextents <= 2);
437 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0, &tp);
441 xfs_ilock(ip, XFS_ILOCK_EXCL);
442 xfs_trans_ijoin(tp, ip, 0);
445 * Lock the inode, fix the size, and join it to the transaction.
446 * Hold it so in the normal path, we still have it locked for
447 * the second transaction. In the error paths we need it
448 * held so the cancel won't rele it, see below.
450 size = (int)ip->i_d.di_size;
452 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
454 * Find the block(s) so we can inval and unmap them.
457 xfs_defer_init(&dfops, &first_block);
458 nmaps = ARRAY_SIZE(mval);
459 error = xfs_bmapi_read(ip, 0, xfs_symlink_blocks(mp, size),
462 goto error_trans_cancel;
464 * Invalidate the block(s). No validation is done.
466 for (i = 0; i < nmaps; i++) {
467 bp = xfs_trans_get_buf(tp, mp->m_ddev_targp,
468 XFS_FSB_TO_DADDR(mp, mval[i].br_startblock),
469 XFS_FSB_TO_BB(mp, mval[i].br_blockcount), 0);
472 goto error_bmap_cancel;
474 xfs_trans_binval(tp, bp);
477 * Unmap the dead block(s) to the dfops.
479 error = xfs_bunmapi(tp, ip, 0, size, 0, nmaps,
480 &first_block, &dfops, &done);
482 goto error_bmap_cancel;
485 * Commit the first transaction. This logs the EFI and the inode.
487 xfs_defer_ijoin(&dfops, ip);
488 error = xfs_defer_finish(&tp, &dfops);
490 goto error_bmap_cancel;
492 * The first xact was committed, so add the inode to the new one.
493 * Mark it dirty so it will be logged and moved forward in the log as
494 * part of every commit.
496 xfs_trans_ijoin(tp, ip, 0);
497 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
499 * Commit the transaction containing extent freeing and EFDs.
501 error = xfs_trans_commit(tp);
503 ASSERT(XFS_FORCED_SHUTDOWN(mp));
508 * Remove the memory for extent descriptions (just bookkeeping).
510 if (ip->i_df.if_bytes)
511 xfs_idata_realloc(ip, -ip->i_df.if_bytes, XFS_DATA_FORK);
512 ASSERT(ip->i_df.if_bytes == 0);
514 xfs_iunlock(ip, XFS_ILOCK_EXCL);
518 xfs_defer_cancel(&dfops);
520 xfs_trans_cancel(tp);
522 xfs_iunlock(ip, XFS_ILOCK_EXCL);
527 * xfs_inactive_symlink - free a symlink
530 xfs_inactive_symlink(
531 struct xfs_inode *ip)
533 struct xfs_mount *mp = ip->i_mount;
536 trace_xfs_inactive_symlink(ip);
538 if (XFS_FORCED_SHUTDOWN(mp))
541 xfs_ilock(ip, XFS_ILOCK_EXCL);
544 * Zero length symlinks _can_ exist.
546 pathlen = (int)ip->i_d.di_size;
548 xfs_iunlock(ip, XFS_ILOCK_EXCL);
552 if (pathlen < 0 || pathlen > XFS_SYMLINK_MAXLEN) {
553 xfs_alert(mp, "%s: inode (0x%llx) bad symlink length (%d)",
554 __func__, (unsigned long long)ip->i_ino, pathlen);
555 xfs_iunlock(ip, XFS_ILOCK_EXCL);
557 return -EFSCORRUPTED;
560 if (ip->i_df.if_flags & XFS_IFINLINE) {
561 if (ip->i_df.if_bytes > 0)
562 xfs_idata_realloc(ip, -(ip->i_df.if_bytes),
564 xfs_iunlock(ip, XFS_ILOCK_EXCL);
565 ASSERT(ip->i_df.if_bytes == 0);
569 xfs_iunlock(ip, XFS_ILOCK_EXCL);
571 /* remove the remote symlink */
572 return xfs_inactive_symlink_rmt(ip);