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"
15 #include "xfs_da_format.h"
16 #include "xfs_da_btree.h"
17 #include "xfs_defer.h"
19 #include "xfs_inode.h"
20 #include "xfs_ialloc.h"
21 #include "xfs_alloc.h"
23 #include "xfs_bmap_btree.h"
24 #include "xfs_bmap_util.h"
25 #include "xfs_error.h"
26 #include "xfs_quota.h"
27 #include "xfs_trans_space.h"
28 #include "xfs_trace.h"
29 #include "xfs_symlink.h"
30 #include "xfs_trans.h"
33 /* ----- Kernel only functions below ----- */
35 xfs_readlink_bmap_ilocked(
39 struct xfs_mount *mp = ip->i_mount;
40 struct xfs_bmbt_irec mval[XFS_SYMLINK_MAPS];
44 int pathlen = ip->i_d.di_size;
45 int nmaps = XFS_SYMLINK_MAPS;
52 ASSERT(xfs_isilocked(ip, XFS_ILOCK_SHARED | XFS_ILOCK_EXCL));
54 fsblocks = xfs_symlink_blocks(mp, pathlen);
55 error = xfs_bmapi_read(ip, 0, fsblocks, mval, &nmaps, 0);
60 for (n = 0; n < nmaps; n++) {
61 d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock);
62 byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);
64 bp = xfs_buf_read(mp->m_ddev_targp, d, BTOBB(byte_cnt), 0,
65 &xfs_symlink_buf_ops);
70 xfs_buf_ioerror_alert(bp, __func__);
73 /* bad CRC means corrupted metadata */
74 if (error == -EFSBADCRC)
75 error = -EFSCORRUPTED;
78 byte_cnt = XFS_SYMLINK_BUF_SPACE(mp, byte_cnt);
79 if (pathlen < byte_cnt)
82 cur_chunk = bp->b_addr;
83 if (xfs_sb_version_hascrc(&mp->m_sb)) {
84 if (!xfs_symlink_hdr_ok(ip->i_ino, offset,
86 error = -EFSCORRUPTED;
88 "symlink header does not match required off/len/owner (0x%x/Ox%x,0x%llx)",
89 offset, byte_cnt, ip->i_ino);
95 cur_chunk += sizeof(struct xfs_dsymlink_hdr);
98 memcpy(link + offset, cur_chunk, byte_cnt);
105 ASSERT(pathlen == 0);
107 link[ip->i_d.di_size] = '\0';
116 struct xfs_inode *ip,
119 struct xfs_mount *mp = ip->i_mount;
123 trace_xfs_readlink(ip);
125 ASSERT(!(ip->i_df.if_flags & XFS_IFINLINE));
127 if (XFS_FORCED_SHUTDOWN(mp))
130 xfs_ilock(ip, XFS_ILOCK_SHARED);
132 pathlen = ip->i_d.di_size;
136 if (pathlen < 0 || pathlen > XFS_SYMLINK_MAXLEN) {
137 xfs_alert(mp, "%s: inode (%llu) bad symlink length (%lld)",
138 __func__, (unsigned long long) ip->i_ino,
139 (long long) pathlen);
141 error = -EFSCORRUPTED;
146 error = xfs_readlink_bmap_ilocked(ip, link);
149 xfs_iunlock(ip, XFS_ILOCK_SHARED);
155 struct xfs_inode *dp,
156 struct xfs_name *link_name,
157 const char *target_path,
159 struct xfs_inode **ipp)
161 struct xfs_mount *mp = dp->i_mount;
162 struct xfs_trans *tp = NULL;
163 struct xfs_inode *ip = NULL;
166 struct xfs_defer_ops dfops;
167 xfs_fsblock_t first_block;
168 bool unlock_dp_on_error = false;
169 xfs_fileoff_t first_fsb;
170 xfs_filblks_t fs_blocks;
172 struct xfs_bmbt_irec mval[XFS_SYMLINK_MAPS];
174 const char *cur_chunk;
179 struct xfs_dquot *udqp = NULL;
180 struct xfs_dquot *gdqp = NULL;
181 struct xfs_dquot *pdqp = NULL;
186 trace_xfs_symlink(dp, link_name);
188 if (XFS_FORCED_SHUTDOWN(mp))
192 * Check component lengths of the target path name.
194 pathlen = strlen(target_path);
195 if (pathlen >= XFS_SYMLINK_MAXLEN) /* total string too long */
196 return -ENAMETOOLONG;
199 prid = xfs_get_initial_prid(dp);
202 * Make sure that we have allocated dquot(s) on disk.
204 error = xfs_qm_vop_dqalloc(dp,
205 xfs_kuid_to_uid(current_fsuid()),
206 xfs_kgid_to_gid(current_fsgid()), prid,
207 XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT,
208 &udqp, &gdqp, &pdqp);
213 * The symlink will fit into the inode data fork?
214 * There can't be any attributes so we get the whole variable part.
216 if (pathlen <= XFS_LITINO(mp, dp->i_d.di_version))
219 fs_blocks = xfs_symlink_blocks(mp, pathlen);
220 resblks = XFS_SYMLINK_SPACE_RES(mp, link_name->len, fs_blocks);
222 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_symlink, resblks, 0, 0, &tp);
224 goto out_release_inode;
226 xfs_ilock(dp, XFS_ILOCK_EXCL | XFS_ILOCK_PARENT);
227 unlock_dp_on_error = true;
230 * Check whether the directory allows new symlinks or not.
232 if (dp->i_d.di_flags & XFS_DIFLAG_NOSYMLINKS) {
234 goto out_trans_cancel;
238 * Reserve disk quota : blocks and inode.
240 error = xfs_trans_reserve_quota(tp, mp, udqp, gdqp,
241 pdqp, resblks, 1, 0);
243 goto out_trans_cancel;
246 * Initialize the bmap freelist prior to calling either
247 * bmapi or the directory create code.
249 xfs_defer_init(&dfops, &first_block);
250 tp->t_agfl_dfops = &dfops;
253 * Allocate an inode for the symlink.
255 error = xfs_dir_ialloc(&tp, dp, S_IFLNK | (mode & ~S_IFMT), 1, 0,
258 goto out_trans_cancel;
261 * Now we join the directory inode to the transaction. We do not do it
262 * earlier because xfs_dir_ialloc might commit the previous transaction
263 * (and release all the locks). An error from here on will result in
264 * the transaction cancel unlocking dp so don't do it explicitly in the
267 xfs_trans_ijoin(tp, dp, XFS_ILOCK_EXCL);
268 unlock_dp_on_error = false;
271 * Also attach the dquot(s) to it, if applicable.
273 xfs_qm_vop_create_dqattach(tp, ip, udqp, gdqp, pdqp);
276 resblks -= XFS_IALLOC_SPACE_RES(mp);
278 * If the symlink will fit into the inode, write it inline.
280 if (pathlen <= XFS_IFORK_DSIZE(ip)) {
281 xfs_init_local_fork(ip, XFS_DATA_FORK, target_path, pathlen);
283 ip->i_d.di_size = pathlen;
284 ip->i_d.di_format = XFS_DINODE_FMT_LOCAL;
285 xfs_trans_log_inode(tp, ip, XFS_ILOG_DDATA | XFS_ILOG_CORE);
290 nmaps = XFS_SYMLINK_MAPS;
292 error = xfs_bmapi_write(tp, ip, first_fsb, fs_blocks,
293 XFS_BMAPI_METADATA, &first_block, resblks,
294 mval, &nmaps, &dfops);
296 goto out_bmap_cancel;
299 resblks -= fs_blocks;
300 ip->i_d.di_size = pathlen;
301 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
303 cur_chunk = target_path;
305 for (n = 0; n < nmaps; n++) {
308 d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock);
309 byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);
310 bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d,
314 goto out_bmap_cancel;
316 bp->b_ops = &xfs_symlink_buf_ops;
318 byte_cnt = XFS_SYMLINK_BUF_SPACE(mp, byte_cnt);
319 byte_cnt = min(byte_cnt, pathlen);
322 buf += xfs_symlink_hdr_set(mp, ip->i_ino, offset,
325 memcpy(buf, cur_chunk, byte_cnt);
327 cur_chunk += byte_cnt;
331 xfs_trans_buf_set_type(tp, bp, XFS_BLFT_SYMLINK_BUF);
332 xfs_trans_log_buf(tp, bp, 0, (buf + byte_cnt - 1) -
335 ASSERT(pathlen == 0);
339 * Create the directory entry for the symlink.
341 error = xfs_dir_createname(tp, dp, link_name, ip->i_ino,
342 &first_block, &dfops, resblks);
344 goto out_bmap_cancel;
345 xfs_trans_ichgtime(tp, dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
346 xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
349 * If this is a synchronous mount, make sure that the
350 * symlink transaction goes to disk before returning to
353 if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC)) {
354 xfs_trans_set_sync(tp);
357 error = xfs_defer_finish(&tp, &dfops);
359 goto out_bmap_cancel;
361 error = xfs_trans_commit(tp);
363 goto out_release_inode;
373 xfs_defer_cancel(&dfops);
375 xfs_trans_cancel(tp);
378 * Wait until after the current transaction is aborted to finish the
379 * setup of the inode and release the inode. This prevents recursive
380 * transactions and deadlocks from xfs_inactive.
383 xfs_finish_inode_setup(ip);
391 if (unlock_dp_on_error)
392 xfs_iunlock(dp, XFS_ILOCK_EXCL);
397 * Free a symlink that has blocks associated with it.
400 xfs_inactive_symlink_rmt(
401 struct xfs_inode *ip)
406 xfs_fsblock_t first_block;
407 struct xfs_defer_ops dfops;
410 xfs_bmbt_irec_t mval[XFS_SYMLINK_MAPS];
416 ASSERT(ip->i_df.if_flags & XFS_IFEXTENTS);
418 * We're freeing a symlink that has some
419 * blocks allocated to it. Free the
420 * blocks here. We know that we've got
421 * either 1 or 2 extents and that we can
422 * free them all in one bunmapi call.
424 ASSERT(ip->i_d.di_nextents > 0 && ip->i_d.di_nextents <= 2);
426 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0, &tp);
430 xfs_ilock(ip, XFS_ILOCK_EXCL);
431 xfs_trans_ijoin(tp, ip, 0);
434 * Lock the inode, fix the size, and join it to the transaction.
435 * Hold it so in the normal path, we still have it locked for
436 * the second transaction. In the error paths we need it
437 * held so the cancel won't rele it, see below.
439 size = (int)ip->i_d.di_size;
441 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
443 * Find the block(s) so we can inval and unmap them.
446 xfs_defer_init(&dfops, &first_block);
447 nmaps = ARRAY_SIZE(mval);
448 error = xfs_bmapi_read(ip, 0, xfs_symlink_blocks(mp, size),
451 goto error_trans_cancel;
453 * Invalidate the block(s). No validation is done.
455 for (i = 0; i < nmaps; i++) {
456 bp = xfs_trans_get_buf(tp, mp->m_ddev_targp,
457 XFS_FSB_TO_DADDR(mp, mval[i].br_startblock),
458 XFS_FSB_TO_BB(mp, mval[i].br_blockcount), 0);
461 goto error_bmap_cancel;
463 xfs_trans_binval(tp, bp);
466 * Unmap the dead block(s) to the dfops.
468 error = xfs_bunmapi(tp, ip, 0, size, 0, nmaps,
469 &first_block, &dfops, &done);
471 goto error_bmap_cancel;
474 * Commit the first transaction. This logs the EFI and the inode.
476 xfs_defer_ijoin(&dfops, ip);
477 error = xfs_defer_finish(&tp, &dfops);
479 goto error_bmap_cancel;
482 * Commit the transaction containing extent freeing and EFDs.
484 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
485 error = xfs_trans_commit(tp);
487 ASSERT(XFS_FORCED_SHUTDOWN(mp));
492 * Remove the memory for extent descriptions (just bookkeeping).
494 if (ip->i_df.if_bytes)
495 xfs_idata_realloc(ip, -ip->i_df.if_bytes, XFS_DATA_FORK);
496 ASSERT(ip->i_df.if_bytes == 0);
498 xfs_iunlock(ip, XFS_ILOCK_EXCL);
502 xfs_defer_cancel(&dfops);
504 xfs_trans_cancel(tp);
506 xfs_iunlock(ip, XFS_ILOCK_EXCL);
511 * xfs_inactive_symlink - free a symlink
514 xfs_inactive_symlink(
515 struct xfs_inode *ip)
517 struct xfs_mount *mp = ip->i_mount;
520 trace_xfs_inactive_symlink(ip);
522 if (XFS_FORCED_SHUTDOWN(mp))
525 xfs_ilock(ip, XFS_ILOCK_EXCL);
528 * Zero length symlinks _can_ exist.
530 pathlen = (int)ip->i_d.di_size;
532 xfs_iunlock(ip, XFS_ILOCK_EXCL);
536 if (pathlen < 0 || pathlen > XFS_SYMLINK_MAXLEN) {
537 xfs_alert(mp, "%s: inode (0x%llx) bad symlink length (%d)",
538 __func__, (unsigned long long)ip->i_ino, pathlen);
539 xfs_iunlock(ip, XFS_ILOCK_EXCL);
541 return -EFSCORRUPTED;
544 if (ip->i_df.if_flags & XFS_IFINLINE) {
545 if (ip->i_df.if_bytes > 0)
546 xfs_idata_realloc(ip, -(ip->i_df.if_bytes),
548 xfs_iunlock(ip, XFS_ILOCK_EXCL);
549 ASSERT(ip->i_df.if_bytes == 0);
553 xfs_iunlock(ip, XFS_ILOCK_EXCL);
555 /* remove the remote symlink */
556 return xfs_inactive_symlink_rmt(ip);