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_bmap_util.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_trace.h"
44 #include "xfs_symlink.h"
46 /* ----- Kernel only functions below ----- */
52 struct xfs_mount *mp = ip->i_mount;
53 struct xfs_bmbt_irec mval[XFS_SYMLINK_MAPS];
57 int pathlen = ip->i_d.di_size;
58 int nmaps = XFS_SYMLINK_MAPS;
65 fsblocks = xfs_symlink_blocks(mp, pathlen);
66 error = xfs_bmapi_read(ip, 0, fsblocks, mval, &nmaps, 0);
71 for (n = 0; n < nmaps; n++) {
72 d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock);
73 byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);
75 bp = xfs_buf_read(mp->m_ddev_targp, d, BTOBB(byte_cnt), 0,
76 &xfs_symlink_buf_ops);
78 return XFS_ERROR(ENOMEM);
81 xfs_buf_ioerror_alert(bp, __func__);
85 byte_cnt = XFS_SYMLINK_BUF_SPACE(mp, byte_cnt);
86 if (pathlen < byte_cnt)
89 cur_chunk = bp->b_addr;
90 if (xfs_sb_version_hascrc(&mp->m_sb)) {
91 if (!xfs_symlink_hdr_ok(mp, ip->i_ino, offset,
95 "symlink header does not match required off/len/owner (0x%x/Ox%x,0x%llx)",
96 offset, byte_cnt, ip->i_ino);
102 cur_chunk += sizeof(struct xfs_dsymlink_hdr);
105 memcpy(link + offset, bp->b_addr, byte_cnt);
112 ASSERT(pathlen == 0);
114 link[ip->i_d.di_size] = '\0';
123 struct xfs_inode *ip,
126 struct xfs_mount *mp = ip->i_mount;
130 trace_xfs_readlink(ip);
132 if (XFS_FORCED_SHUTDOWN(mp))
133 return XFS_ERROR(EIO);
135 xfs_ilock(ip, XFS_ILOCK_SHARED);
137 pathlen = ip->i_d.di_size;
141 if (pathlen < 0 || pathlen > MAXPATHLEN) {
142 xfs_alert(mp, "%s: inode (%llu) bad symlink length (%lld)",
143 __func__, (unsigned long long) ip->i_ino,
144 (long long) pathlen);
146 error = XFS_ERROR(EFSCORRUPTED);
151 if (ip->i_df.if_flags & XFS_IFINLINE) {
152 memcpy(link, ip->i_df.if_u1.if_data, pathlen);
153 link[pathlen] = '\0';
155 error = xfs_readlink_bmap(ip, link);
159 xfs_iunlock(ip, XFS_ILOCK_SHARED);
165 struct xfs_inode *dp,
166 struct xfs_name *link_name,
167 const char *target_path,
169 struct xfs_inode **ipp)
171 struct xfs_mount *mp = dp->i_mount;
172 struct xfs_trans *tp = NULL;
173 struct xfs_inode *ip = NULL;
176 struct xfs_bmap_free free_list;
177 xfs_fsblock_t first_block;
178 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))
201 return XFS_ERROR(EIO);
204 * Check component lengths of the target path name.
206 pathlen = strlen(target_path);
207 if (pathlen >= MAXPATHLEN) /* total string too long */
208 return XFS_ERROR(ENAMETOOLONG);
211 if (dp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT)
212 prid = xfs_get_projid(dp);
214 prid = XFS_PROJID_DEFAULT;
217 * Make sure that we have allocated dquot(s) on disk.
219 error = xfs_qm_vop_dqalloc(dp, current_fsuid(), current_fsgid(), prid,
220 XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT, &udqp, &gdqp, &pdqp);
224 tp = xfs_trans_alloc(mp, XFS_TRANS_SYMLINK);
225 cancel_flags = XFS_TRANS_RELEASE_LOG_RES;
227 * The symlink will fit into the inode data fork?
228 * There can't be any attributes so we get the whole variable part.
230 if (pathlen <= XFS_LITINO(mp, dp->i_d.di_version))
233 fs_blocks = xfs_symlink_blocks(mp, pathlen);
234 resblks = XFS_SYMLINK_SPACE_RES(mp, link_name->len, fs_blocks);
235 error = xfs_trans_reserve(tp, resblks, XFS_SYMLINK_LOG_RES(mp), 0,
236 XFS_TRANS_PERM_LOG_RES, XFS_SYMLINK_LOG_COUNT);
237 if (error == ENOSPC && fs_blocks == 0) {
239 error = xfs_trans_reserve(tp, 0, XFS_SYMLINK_LOG_RES(mp), 0,
240 XFS_TRANS_PERM_LOG_RES, XFS_SYMLINK_LOG_COUNT);
247 xfs_ilock(dp, XFS_ILOCK_EXCL | XFS_ILOCK_PARENT);
248 unlock_dp_on_error = true;
251 * Check whether the directory allows new symlinks or not.
253 if (dp->i_d.di_flags & XFS_DIFLAG_NOSYMLINKS) {
254 error = XFS_ERROR(EPERM);
259 * Reserve disk quota : blocks and inode.
261 error = xfs_trans_reserve_quota(tp, mp, udqp, gdqp,
262 pdqp, resblks, 1, 0);
267 * Check for ability to enter directory entry, if no space reserved.
269 error = xfs_dir_canenter(tp, dp, link_name, resblks);
273 * Initialize the bmap freelist prior to calling either
274 * bmapi or the directory create code.
276 xfs_bmap_init(&free_list, &first_block);
279 * Allocate an inode for the symlink.
281 error = xfs_dir_ialloc(&tp, dp, S_IFLNK | (mode & ~S_IFMT), 1, 0,
282 prid, resblks > 0, &ip, NULL);
290 * An error after we've joined dp to the transaction will result in the
291 * transaction cancel unlocking dp so don't do it explicitly in the
294 xfs_trans_ijoin(tp, dp, XFS_ILOCK_EXCL);
295 unlock_dp_on_error = false;
298 * Also attach the dquot(s) to it, if applicable.
300 xfs_qm_vop_create_dqattach(tp, ip, udqp, gdqp, pdqp);
303 resblks -= XFS_IALLOC_SPACE_RES(mp);
305 * If the symlink will fit into the inode, write it inline.
307 if (pathlen <= XFS_IFORK_DSIZE(ip)) {
308 xfs_idata_realloc(ip, pathlen, XFS_DATA_FORK);
309 memcpy(ip->i_df.if_u1.if_data, target_path, pathlen);
310 ip->i_d.di_size = pathlen;
313 * The inode was initially created in extent format.
315 ip->i_df.if_flags &= ~(XFS_IFEXTENTS | XFS_IFBROOT);
316 ip->i_df.if_flags |= XFS_IFINLINE;
318 ip->i_d.di_format = XFS_DINODE_FMT_LOCAL;
319 xfs_trans_log_inode(tp, ip, XFS_ILOG_DDATA | XFS_ILOG_CORE);
325 nmaps = XFS_SYMLINK_MAPS;
327 error = xfs_bmapi_write(tp, ip, first_fsb, fs_blocks,
328 XFS_BMAPI_METADATA, &first_block, resblks,
329 mval, &nmaps, &free_list);
334 resblks -= fs_blocks;
335 ip->i_d.di_size = pathlen;
336 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
338 cur_chunk = target_path;
340 for (n = 0; n < nmaps; n++) {
343 d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock);
344 byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);
345 bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d,
351 bp->b_ops = &xfs_symlink_buf_ops;
353 byte_cnt = XFS_SYMLINK_BUF_SPACE(mp, byte_cnt);
354 byte_cnt = min(byte_cnt, pathlen);
357 buf += xfs_symlink_hdr_set(mp, ip->i_ino, offset,
360 memcpy(buf, cur_chunk, byte_cnt);
362 cur_chunk += byte_cnt;
366 xfs_trans_log_buf(tp, bp, 0, (buf + byte_cnt - 1) -
369 ASSERT(pathlen == 0);
373 * Create the directory entry for the symlink.
375 error = xfs_dir_createname(tp, dp, link_name, ip->i_ino,
376 &first_block, &free_list, resblks);
379 xfs_trans_ichgtime(tp, dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
380 xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
383 * If this is a synchronous mount, make sure that the
384 * symlink transaction goes to disk before returning to
387 if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC)) {
388 xfs_trans_set_sync(tp);
391 error = xfs_bmap_finish(&tp, &free_list, &committed);
395 error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
406 xfs_bmap_cancel(&free_list);
407 cancel_flags |= XFS_TRANS_ABORT;
409 xfs_trans_cancel(tp, cancel_flags);
414 if (unlock_dp_on_error)
415 xfs_iunlock(dp, XFS_ILOCK_EXCL);
421 * Free a symlink that has blocks associated with it.
424 xfs_inactive_symlink_rmt(
432 xfs_fsblock_t first_block;
433 xfs_bmap_free_t free_list;
436 xfs_bmbt_irec_t mval[XFS_SYMLINK_MAPS];
444 ASSERT(ip->i_df.if_flags & XFS_IFEXTENTS);
446 * We're freeing a symlink that has some
447 * blocks allocated to it. Free the
448 * blocks here. We know that we've got
449 * either 1 or 2 extents and that we can
450 * free them all in one bunmapi call.
452 ASSERT(ip->i_d.di_nextents > 0 && ip->i_d.di_nextents <= 2);
455 * Lock the inode, fix the size, and join it to the transaction.
456 * Hold it so in the normal path, we still have it locked for
457 * the second transaction. In the error paths we need it
458 * held so the cancel won't rele it, see below.
460 size = (int)ip->i_d.di_size;
462 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
464 * Find the block(s) so we can inval and unmap them.
467 xfs_bmap_init(&free_list, &first_block);
468 nmaps = ARRAY_SIZE(mval);
469 error = xfs_bmapi_read(ip, 0, xfs_symlink_blocks(mp, size),
474 * Invalidate the block(s). No validation is done.
476 for (i = 0; i < nmaps; i++) {
477 bp = xfs_trans_get_buf(tp, mp->m_ddev_targp,
478 XFS_FSB_TO_DADDR(mp, mval[i].br_startblock),
479 XFS_FSB_TO_BB(mp, mval[i].br_blockcount), 0);
484 xfs_trans_binval(tp, bp);
487 * Unmap the dead block(s) to the free_list.
489 if ((error = xfs_bunmapi(tp, ip, 0, size, XFS_BMAPI_METADATA, nmaps,
490 &first_block, &free_list, &done)))
494 * Commit the first transaction. This logs the EFI and the inode.
496 if ((error = xfs_bmap_finish(&tp, &free_list, &committed)))
499 * The transaction must have been committed, since there were
500 * actually extents freed by xfs_bunmapi. See xfs_bmap_finish.
501 * The new tp has the extent freeing and EFDs.
505 * The first xact was committed, so add the inode to the new one.
506 * Mark it dirty so it will be logged and moved forward in the log as
507 * part of every commit.
509 xfs_trans_ijoin(tp, ip, 0);
510 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
512 * Get a new, empty transaction to return to our caller.
514 ntp = xfs_trans_dup(tp);
516 * Commit the transaction containing extent freeing and EFDs.
517 * If we get an error on the commit here or on the reserve below,
518 * we need to unlock the inode since the new transaction doesn't
519 * have the inode attached.
521 error = xfs_trans_commit(tp, 0);
524 ASSERT(XFS_FORCED_SHUTDOWN(mp));
528 * transaction commit worked ok so we can drop the extra ticket
529 * reference that we gained in xfs_trans_dup()
531 xfs_log_ticket_put(tp->t_ticket);
534 * Remove the memory for extent descriptions (just bookkeeping).
536 if (ip->i_df.if_bytes)
537 xfs_idata_realloc(ip, -ip->i_df.if_bytes, XFS_DATA_FORK);
538 ASSERT(ip->i_df.if_bytes == 0);
540 * Put an itruncate log reservation in the new transaction
543 if ((error = xfs_trans_reserve(tp, 0, XFS_ITRUNCATE_LOG_RES(mp), 0,
544 XFS_TRANS_PERM_LOG_RES, XFS_ITRUNCATE_LOG_COUNT))) {
545 ASSERT(XFS_FORCED_SHUTDOWN(mp));
549 xfs_trans_ijoin(tp, ip, 0);
554 xfs_bmap_cancel(&free_list);
560 * xfs_inactive_symlink - free a symlink
563 xfs_inactive_symlink(
564 struct xfs_inode *ip,
565 struct xfs_trans **tp)
567 struct xfs_mount *mp = ip->i_mount;
570 trace_xfs_inactive_symlink(ip);
572 ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
574 if (XFS_FORCED_SHUTDOWN(mp))
575 return XFS_ERROR(EIO);
578 * Zero length symlinks _can_ exist.
580 pathlen = (int)ip->i_d.di_size;
584 if (pathlen < 0 || pathlen > MAXPATHLEN) {
585 xfs_alert(mp, "%s: inode (0x%llx) bad symlink length (%d)",
586 __func__, (unsigned long long)ip->i_ino, pathlen);
588 return XFS_ERROR(EFSCORRUPTED);
591 if (ip->i_df.if_flags & XFS_IFINLINE) {
592 if (ip->i_df.if_bytes > 0)
593 xfs_idata_realloc(ip, -(ip->i_df.if_bytes),
595 ASSERT(ip->i_df.if_bytes == 0);
599 /* remove the remote symlink */
600 return xfs_inactive_symlink_rmt(ip, tp);