1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (c) 2000-2006 Silicon Graphics, Inc.
4 * Copyright (c) 2012-2013 Red Hat, Inc.
8 #include "xfs_shared.h"
10 #include "xfs_format.h"
11 #include "xfs_log_format.h"
12 #include "xfs_trans_resv.h"
14 #include "xfs_mount.h"
16 #include "xfs_inode.h"
18 #include "xfs_bmap_btree.h"
19 #include "xfs_quota.h"
20 #include "xfs_symlink.h"
21 #include "xfs_trans_space.h"
22 #include "xfs_trace.h"
23 #include "xfs_trans.h"
25 /* ----- Kernel only functions below ----- */
27 xfs_readlink_bmap_ilocked(
31 struct xfs_mount *mp = ip->i_mount;
32 struct xfs_bmbt_irec mval[XFS_SYMLINK_MAPS];
36 int pathlen = ip->i_d.di_size;
37 int nmaps = XFS_SYMLINK_MAPS;
44 ASSERT(xfs_isilocked(ip, XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
46 fsblocks = xfs_symlink_blocks(mp, pathlen);
47 error = xfs_bmapi_read(ip, 0, fsblocks, mval, &nmaps, 0);
52 for (n = 0; n < nmaps; n++) {
53 d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock);
54 byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);
56 error = xfs_buf_read(mp->m_ddev_targp, d, BTOBB(byte_cnt), 0,
57 &bp, &xfs_symlink_buf_ops);
60 byte_cnt = XFS_SYMLINK_BUF_SPACE(mp, byte_cnt);
61 if (pathlen < byte_cnt)
64 cur_chunk = bp->b_addr;
65 if (xfs_sb_version_hascrc(&mp->m_sb)) {
66 if (!xfs_symlink_hdr_ok(ip->i_ino, offset,
68 error = -EFSCORRUPTED;
70 "symlink header does not match required off/len/owner (0x%x/Ox%x,0x%llx)",
71 offset, byte_cnt, ip->i_ino);
77 cur_chunk += sizeof(struct xfs_dsymlink_hdr);
80 memcpy(link + offset, cur_chunk, byte_cnt);
89 link[ip->i_d.di_size] = '\0';
101 struct xfs_mount *mp = ip->i_mount;
105 trace_xfs_readlink(ip);
107 ASSERT(!(ip->i_df.if_flags & XFS_IFINLINE));
109 if (XFS_FORCED_SHUTDOWN(mp))
112 xfs_ilock(ip, XFS_ILOCK_SHARED);
114 pathlen = ip->i_d.di_size;
118 if (pathlen < 0 || pathlen > XFS_SYMLINK_MAXLEN) {
119 xfs_alert(mp, "%s: inode (%llu) bad symlink length (%lld)",
120 __func__, (unsigned long long) ip->i_ino,
121 (long long) pathlen);
123 error = -EFSCORRUPTED;
128 error = xfs_readlink_bmap_ilocked(ip, link);
131 xfs_iunlock(ip, XFS_ILOCK_SHARED);
137 struct xfs_inode *dp,
138 struct xfs_name *link_name,
139 const char *target_path,
141 struct xfs_inode **ipp)
143 struct xfs_mount *mp = dp->i_mount;
144 struct xfs_trans *tp = NULL;
145 struct xfs_inode *ip = NULL;
148 bool unlock_dp_on_error = false;
149 xfs_fileoff_t first_fsb;
150 xfs_filblks_t fs_blocks;
152 struct xfs_bmbt_irec mval[XFS_SYMLINK_MAPS];
154 const char *cur_chunk;
159 struct xfs_dquot *udqp = NULL;
160 struct xfs_dquot *gdqp = NULL;
161 struct xfs_dquot *pdqp = NULL;
166 trace_xfs_symlink(dp, link_name);
168 if (XFS_FORCED_SHUTDOWN(mp))
172 * Check component lengths of the target path name.
174 pathlen = strlen(target_path);
175 if (pathlen >= XFS_SYMLINK_MAXLEN) /* total string too long */
176 return -ENAMETOOLONG;
180 prid = xfs_get_initial_prid(dp);
183 * Make sure that we have allocated dquot(s) on disk.
185 error = xfs_qm_vop_dqalloc(dp, current_fsuid(), current_fsgid(), prid,
186 XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT,
187 &udqp, &gdqp, &pdqp);
192 * The symlink will fit into the inode data fork?
193 * There can't be any attributes so we get the whole variable part.
195 if (pathlen <= XFS_LITINO(mp))
198 fs_blocks = xfs_symlink_blocks(mp, pathlen);
199 resblks = XFS_SYMLINK_SPACE_RES(mp, link_name->len, fs_blocks);
201 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_symlink, resblks, 0, 0, &tp);
203 goto out_release_inode;
205 xfs_ilock(dp, XFS_ILOCK_EXCL | XFS_ILOCK_PARENT);
206 unlock_dp_on_error = true;
209 * Check whether the directory allows new symlinks or not.
211 if (dp->i_d.di_flags & XFS_DIFLAG_NOSYMLINKS) {
213 goto out_trans_cancel;
217 * Reserve disk quota : blocks and inode.
219 error = xfs_trans_reserve_quota(tp, mp, udqp, gdqp,
220 pdqp, resblks, 1, 0);
222 goto out_trans_cancel;
225 * Allocate an inode for the symlink.
227 error = xfs_dir_ialloc(&tp, dp, S_IFLNK | (mode & ~S_IFMT), 1, 0,
230 goto out_trans_cancel;
233 * Now we join the directory inode to the transaction. We do not do it
234 * earlier because xfs_dir_ialloc might commit the previous transaction
235 * (and release all the locks). An error from here on will result in
236 * the transaction cancel unlocking dp so don't do it explicitly in the
239 xfs_trans_ijoin(tp, dp, XFS_ILOCK_EXCL);
240 unlock_dp_on_error = false;
243 * Also attach the dquot(s) to it, if applicable.
245 xfs_qm_vop_create_dqattach(tp, ip, udqp, gdqp, pdqp);
248 resblks -= XFS_IALLOC_SPACE_RES(mp);
250 * If the symlink will fit into the inode, write it inline.
252 if (pathlen <= XFS_IFORK_DSIZE(ip)) {
253 xfs_init_local_fork(ip, XFS_DATA_FORK, target_path, pathlen);
255 ip->i_d.di_size = pathlen;
256 ip->i_d.di_format = XFS_DINODE_FMT_LOCAL;
257 xfs_trans_log_inode(tp, ip, XFS_ILOG_DDATA | XFS_ILOG_CORE);
262 nmaps = XFS_SYMLINK_MAPS;
264 error = xfs_bmapi_write(tp, ip, first_fsb, fs_blocks,
265 XFS_BMAPI_METADATA, resblks, mval, &nmaps);
267 goto out_trans_cancel;
270 resblks -= fs_blocks;
271 ip->i_d.di_size = pathlen;
272 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
274 cur_chunk = target_path;
276 for (n = 0; n < nmaps; n++) {
279 d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock);
280 byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);
281 error = xfs_trans_get_buf(tp, mp->m_ddev_targp, d,
282 BTOBB(byte_cnt), 0, &bp);
284 goto out_trans_cancel;
285 bp->b_ops = &xfs_symlink_buf_ops;
287 byte_cnt = XFS_SYMLINK_BUF_SPACE(mp, byte_cnt);
288 byte_cnt = min(byte_cnt, pathlen);
291 buf += xfs_symlink_hdr_set(mp, ip->i_ino, offset,
294 memcpy(buf, cur_chunk, byte_cnt);
296 cur_chunk += byte_cnt;
300 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_SYMLINK_BUF);
301 xfs_trans_log_buf(tp, bp, 0, (buf + byte_cnt - 1) -
304 ASSERT(pathlen == 0);
308 * Create the directory entry for the symlink.
310 error = xfs_dir_createname(tp, dp, link_name, ip->i_ino, resblks);
312 goto out_trans_cancel;
313 xfs_trans_ichgtime(tp, dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
314 xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
317 * If this is a synchronous mount, make sure that the
318 * symlink transaction goes to disk before returning to
321 if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC)) {
322 xfs_trans_set_sync(tp);
325 error = xfs_trans_commit(tp);
327 goto out_release_inode;
337 xfs_trans_cancel(tp);
340 * Wait until after the current transaction is aborted to finish the
341 * setup of the inode and release the inode. This prevents recursive
342 * transactions and deadlocks from xfs_inactive.
345 xfs_finish_inode_setup(ip);
353 if (unlock_dp_on_error)
354 xfs_iunlock(dp, XFS_ILOCK_EXCL);
359 * Free a symlink that has blocks associated with it.
361 * Note: zero length symlinks are not allowed to exist. When we set the size to
362 * zero, also change it to a regular file so that it does not get written to
363 * disk as a zero length symlink. The inode is on the unlinked list already, so
364 * userspace cannot find this inode anymore, so this change is not user visible
365 * but allows us to catch corrupt zero-length symlinks in the verifiers.
368 xfs_inactive_symlink_rmt(
369 struct xfs_inode *ip)
376 xfs_bmbt_irec_t mval[XFS_SYMLINK_MAPS];
382 ASSERT(ip->i_df.if_flags & XFS_IFEXTENTS);
384 * We're freeing a symlink that has some
385 * blocks allocated to it. Free the
386 * blocks here. We know that we've got
387 * either 1 or 2 extents and that we can
388 * free them all in one bunmapi call.
390 ASSERT(ip->i_d.di_nextents > 0 && ip->i_d.di_nextents <= 2);
392 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0, &tp);
396 xfs_ilock(ip, XFS_ILOCK_EXCL);
397 xfs_trans_ijoin(tp, ip, 0);
400 * Lock the inode, fix the size, turn it into a regular file and join it
401 * to the transaction. Hold it so in the normal path, we still have it
402 * locked for the second transaction. In the error paths we need it
403 * held so the cancel won't rele it, see below.
405 size = (int)ip->i_d.di_size;
407 VFS_I(ip)->i_mode = (VFS_I(ip)->i_mode & ~S_IFMT) | S_IFREG;
408 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
410 * Find the block(s) so we can inval and unmap them.
413 nmaps = ARRAY_SIZE(mval);
414 error = xfs_bmapi_read(ip, 0, xfs_symlink_blocks(mp, size),
417 goto error_trans_cancel;
419 * Invalidate the block(s). No validation is done.
421 for (i = 0; i < nmaps; i++) {
422 error = xfs_trans_get_buf(tp, mp->m_ddev_targp,
423 XFS_FSB_TO_DADDR(mp, mval[i].br_startblock),
424 XFS_FSB_TO_BB(mp, mval[i].br_blockcount), 0,
427 goto error_trans_cancel;
428 xfs_trans_binval(tp, bp);
431 * Unmap the dead block(s) to the dfops.
433 error = xfs_bunmapi(tp, ip, 0, size, 0, nmaps, &done);
435 goto error_trans_cancel;
439 * Commit the transaction. This first logs the EFI and the inode, then
440 * rolls and commits the transaction that frees the extents.
442 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
443 error = xfs_trans_commit(tp);
445 ASSERT(XFS_FORCED_SHUTDOWN(mp));
450 * Remove the memory for extent descriptions (just bookkeeping).
452 if (ip->i_df.if_bytes)
453 xfs_idata_realloc(ip, -ip->i_df.if_bytes, XFS_DATA_FORK);
454 ASSERT(ip->i_df.if_bytes == 0);
456 xfs_iunlock(ip, XFS_ILOCK_EXCL);
460 xfs_trans_cancel(tp);
462 xfs_iunlock(ip, XFS_ILOCK_EXCL);
467 * xfs_inactive_symlink - free a symlink
470 xfs_inactive_symlink(
471 struct xfs_inode *ip)
473 struct xfs_mount *mp = ip->i_mount;
476 trace_xfs_inactive_symlink(ip);
478 if (XFS_FORCED_SHUTDOWN(mp))
481 xfs_ilock(ip, XFS_ILOCK_EXCL);
482 pathlen = (int)ip->i_d.di_size;
485 if (pathlen <= 0 || pathlen > XFS_SYMLINK_MAXLEN) {
486 xfs_alert(mp, "%s: inode (0x%llx) bad symlink length (%d)",
487 __func__, (unsigned long long)ip->i_ino, pathlen);
488 xfs_iunlock(ip, XFS_ILOCK_EXCL);
490 return -EFSCORRUPTED;
494 * Inline fork state gets removed by xfs_difree() so we have nothing to
495 * do here in that case.
497 if (ip->i_df.if_flags & XFS_IFINLINE) {
498 xfs_iunlock(ip, XFS_ILOCK_EXCL);
502 xfs_iunlock(ip, XFS_ILOCK_EXCL);
504 /* remove the remote symlink */
505 return xfs_inactive_symlink_rmt(ip);