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1/*
2 * Copyright (c) 2000-2006 Silicon Graphics, Inc.
3 * All Rights Reserved.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18#include "xfs.h"
19#include "xfs_fs.h"
20#include "xfs_types.h"
21#include "xfs_bit.h"
22#include "xfs_log.h"
23#include "xfs_inum.h"
24#include "xfs_trans.h"
25#include "xfs_sb.h"
26#include "xfs_ag.h"
27#include "xfs_mount.h"
28#include "xfs_bmap_btree.h"
29#include "xfs_dinode.h"
30#include "xfs_inode.h"
31#include "xfs_inode_item.h"
32#include "xfs_bmap.h"
33#include "xfs_itable.h"
34#include "xfs_dfrag.h"
35#include "xfs_error.h"
36#include "xfs_vnodeops.h"
37#include "xfs_trace.h"
38
39
40static int xfs_swap_extents(
41 xfs_inode_t *ip, /* target inode */
42 xfs_inode_t *tip, /* tmp inode */
43 xfs_swapext_t *sxp);
44
45/*
46 * ioctl interface for swapext
47 */
48int
49xfs_swapext(
50 xfs_swapext_t *sxp)
51{
52 xfs_inode_t *ip, *tip;
53 struct file *file, *tmp_file;
54 int error = 0;
55
56 /* Pull information for the target fd */
57 file = fget((int)sxp->sx_fdtarget);
58 if (!file) {
59 error = XFS_ERROR(EINVAL);
60 goto out;
61 }
62
63 if (!(file->f_mode & FMODE_WRITE) ||
64 !(file->f_mode & FMODE_READ) ||
65 (file->f_flags & O_APPEND)) {
66 error = XFS_ERROR(EBADF);
67 goto out_put_file;
68 }
69
70 tmp_file = fget((int)sxp->sx_fdtmp);
71 if (!tmp_file) {
72 error = XFS_ERROR(EINVAL);
73 goto out_put_file;
74 }
75
76 if (!(tmp_file->f_mode & FMODE_WRITE) ||
77 !(tmp_file->f_mode & FMODE_READ) ||
78 (tmp_file->f_flags & O_APPEND)) {
79 error = XFS_ERROR(EBADF);
80 goto out_put_tmp_file;
81 }
82
83 if (IS_SWAPFILE(file->f_path.dentry->d_inode) ||
84 IS_SWAPFILE(tmp_file->f_path.dentry->d_inode)) {
85 error = XFS_ERROR(EINVAL);
86 goto out_put_tmp_file;
87 }
88
89 ip = XFS_I(file->f_path.dentry->d_inode);
90 tip = XFS_I(tmp_file->f_path.dentry->d_inode);
91
92 if (ip->i_mount != tip->i_mount) {
93 error = XFS_ERROR(EINVAL);
94 goto out_put_tmp_file;
95 }
96
97 if (ip->i_ino == tip->i_ino) {
98 error = XFS_ERROR(EINVAL);
99 goto out_put_tmp_file;
100 }
101
102 if (XFS_FORCED_SHUTDOWN(ip->i_mount)) {
103 error = XFS_ERROR(EIO);
104 goto out_put_tmp_file;
105 }
106
107 error = xfs_swap_extents(ip, tip, sxp);
108
109 out_put_tmp_file:
110 fput(tmp_file);
111 out_put_file:
112 fput(file);
113 out:
114 return error;
115}
116
117/*
118 * We need to check that the format of the data fork in the temporary inode is
119 * valid for the target inode before doing the swap. This is not a problem with
120 * attr1 because of the fixed fork offset, but attr2 has a dynamically sized
121 * data fork depending on the space the attribute fork is taking so we can get
122 * invalid formats on the target inode.
123 *
124 * E.g. target has space for 7 extents in extent format, temp inode only has
125 * space for 6. If we defragment down to 7 extents, then the tmp format is a
126 * btree, but when swapped it needs to be in extent format. Hence we can't just
127 * blindly swap data forks on attr2 filesystems.
128 *
129 * Note that we check the swap in both directions so that we don't end up with
130 * a corrupt temporary inode, either.
131 *
132 * Note that fixing the way xfs_fsr sets up the attribute fork in the source
133 * inode will prevent this situation from occurring, so all we do here is
134 * reject and log the attempt. basically we are putting the responsibility on
135 * userspace to get this right.
136 */
137static int
138xfs_swap_extents_check_format(
139 xfs_inode_t *ip, /* target inode */
140 xfs_inode_t *tip) /* tmp inode */
141{
142
143 /* Should never get a local format */
144 if (ip->i_d.di_format == XFS_DINODE_FMT_LOCAL ||
145 tip->i_d.di_format == XFS_DINODE_FMT_LOCAL)
146 return EINVAL;
147
148 /*
149 * if the target inode has less extents that then temporary inode then
150 * why did userspace call us?
151 */
152 if (ip->i_d.di_nextents < tip->i_d.di_nextents)
153 return EINVAL;
154
155 /*
156 * if the target inode is in extent form and the temp inode is in btree
157 * form then we will end up with the target inode in the wrong format
158 * as we already know there are less extents in the temp inode.
159 */
160 if (ip->i_d.di_format == XFS_DINODE_FMT_EXTENTS &&
161 tip->i_d.di_format == XFS_DINODE_FMT_BTREE)
162 return EINVAL;
163
164 /* Check temp in extent form to max in target */
165 if (tip->i_d.di_format == XFS_DINODE_FMT_EXTENTS &&
166 XFS_IFORK_NEXTENTS(tip, XFS_DATA_FORK) > ip->i_df.if_ext_max)
167 return EINVAL;
168
169 /* Check target in extent form to max in temp */
170 if (ip->i_d.di_format == XFS_DINODE_FMT_EXTENTS &&
171 XFS_IFORK_NEXTENTS(ip, XFS_DATA_FORK) > tip->i_df.if_ext_max)
172 return EINVAL;
173
174 /*
175 * If we are in a btree format, check that the temp root block will fit
176 * in the target and that it has enough extents to be in btree format
177 * in the target.
178 *
179 * Note that we have to be careful to allow btree->extent conversions
180 * (a common defrag case) which will occur when the temp inode is in
181 * extent format...
182 */
183 if (tip->i_d.di_format == XFS_DINODE_FMT_BTREE &&
184 ((XFS_IFORK_BOFF(ip) &&
185 tip->i_df.if_broot_bytes > XFS_IFORK_BOFF(ip)) ||
186 XFS_IFORK_NEXTENTS(tip, XFS_DATA_FORK) <= ip->i_df.if_ext_max))
187 return EINVAL;
188
189 /* Reciprocal target->temp btree format checks */
190 if (ip->i_d.di_format == XFS_DINODE_FMT_BTREE &&
191 ((XFS_IFORK_BOFF(tip) &&
192 ip->i_df.if_broot_bytes > XFS_IFORK_BOFF(tip)) ||
193 XFS_IFORK_NEXTENTS(ip, XFS_DATA_FORK) <= tip->i_df.if_ext_max))
194 return EINVAL;
195
196 return 0;
197}
198
199static int
200xfs_swap_extents(
201 xfs_inode_t *ip, /* target inode */
202 xfs_inode_t *tip, /* tmp inode */
203 xfs_swapext_t *sxp)
204{
205 xfs_mount_t *mp = ip->i_mount;
206 xfs_trans_t *tp;
207 xfs_bstat_t *sbp = &sxp->sx_stat;
208 xfs_ifork_t *tempifp, *ifp, *tifp;
209 int ilf_fields, tilf_fields;
210 int error = 0;
211 int aforkblks = 0;
212 int taforkblks = 0;
213 __uint64_t tmp;
214
215 tempifp = kmem_alloc(sizeof(xfs_ifork_t), KM_MAYFAIL);
216 if (!tempifp) {
217 error = XFS_ERROR(ENOMEM);
218 goto out;
219 }
220
221 /*
222 * we have to do two separate lock calls here to keep lockdep
223 * happy. If we try to get all the locks in one call, lock will
224 * report false positives when we drop the ILOCK and regain them
225 * below.
226 */
227 xfs_lock_two_inodes(ip, tip, XFS_IOLOCK_EXCL);
228 xfs_lock_two_inodes(ip, tip, XFS_ILOCK_EXCL);
229
230 /* Verify that both files have the same format */
231 if ((ip->i_d.di_mode & S_IFMT) != (tip->i_d.di_mode & S_IFMT)) {
232 error = XFS_ERROR(EINVAL);
233 goto out_unlock;
234 }
235
236 /* Verify both files are either real-time or non-realtime */
237 if (XFS_IS_REALTIME_INODE(ip) != XFS_IS_REALTIME_INODE(tip)) {
238 error = XFS_ERROR(EINVAL);
239 goto out_unlock;
240 }
241
242 if (VN_CACHED(VFS_I(tip)) != 0) {
243 error = xfs_flushinval_pages(tip, 0, -1,
244 FI_REMAPF_LOCKED);
245 if (error)
246 goto out_unlock;
247 }
248
249 /* Verify O_DIRECT for ftmp */
250 if (VN_CACHED(VFS_I(tip)) != 0) {
251 error = XFS_ERROR(EINVAL);
252 goto out_unlock;
253 }
254
255 /* Verify all data are being swapped */
256 if (sxp->sx_offset != 0 ||
257 sxp->sx_length != ip->i_d.di_size ||
258 sxp->sx_length != tip->i_d.di_size) {
259 error = XFS_ERROR(EFAULT);
260 goto out_unlock;
261 }
262
263 trace_xfs_swap_extent_before(ip, 0);
264 trace_xfs_swap_extent_before(tip, 1);
265
266 /* check inode formats now that data is flushed */
267 error = xfs_swap_extents_check_format(ip, tip);
268 if (error) {
269 xfs_notice(mp,
270 "%s: inode 0x%llx format is incompatible for exchanging.",
271 __func__, ip->i_ino);
272 goto out_unlock;
273 }
274
275 /*
276 * Compare the current change & modify times with that
277 * passed in. If they differ, we abort this swap.
278 * This is the mechanism used to ensure the calling
279 * process that the file was not changed out from
280 * under it.
281 */
282 if ((sbp->bs_ctime.tv_sec != VFS_I(ip)->i_ctime.tv_sec) ||
283 (sbp->bs_ctime.tv_nsec != VFS_I(ip)->i_ctime.tv_nsec) ||
284 (sbp->bs_mtime.tv_sec != VFS_I(ip)->i_mtime.tv_sec) ||
285 (sbp->bs_mtime.tv_nsec != VFS_I(ip)->i_mtime.tv_nsec)) {
286 error = XFS_ERROR(EBUSY);
287 goto out_unlock;
288 }
289
290 /* We need to fail if the file is memory mapped. Once we have tossed
291 * all existing pages, the page fault will have no option
292 * but to go to the filesystem for pages. By making the page fault call
293 * vop_read (or write in the case of autogrow) they block on the iolock
294 * until we have switched the extents.
295 */
296 if (VN_MAPPED(VFS_I(ip))) {
297 error = XFS_ERROR(EBUSY);
298 goto out_unlock;
299 }
300
301 xfs_iunlock(ip, XFS_ILOCK_EXCL);
302 xfs_iunlock(tip, XFS_ILOCK_EXCL);
303
304 /*
305 * There is a race condition here since we gave up the
306 * ilock. However, the data fork will not change since
307 * we have the iolock (locked for truncation too) so we
308 * are safe. We don't really care if non-io related
309 * fields change.
310 */
311
312 xfs_tosspages(ip, 0, -1, FI_REMAPF);
313
314 tp = xfs_trans_alloc(mp, XFS_TRANS_SWAPEXT);
315 if ((error = xfs_trans_reserve(tp, 0,
316 XFS_ICHANGE_LOG_RES(mp), 0,
317 0, 0))) {
318 xfs_iunlock(ip, XFS_IOLOCK_EXCL);
319 xfs_iunlock(tip, XFS_IOLOCK_EXCL);
320 xfs_trans_cancel(tp, 0);
321 goto out;
322 }
323 xfs_lock_two_inodes(ip, tip, XFS_ILOCK_EXCL);
324
325 /*
326 * Count the number of extended attribute blocks
327 */
328 if ( ((XFS_IFORK_Q(ip) != 0) && (ip->i_d.di_anextents > 0)) &&
329 (ip->i_d.di_aformat != XFS_DINODE_FMT_LOCAL)) {
330 error = xfs_bmap_count_blocks(tp, ip, XFS_ATTR_FORK, &aforkblks);
331 if (error)
332 goto out_trans_cancel;
333 }
334 if ( ((XFS_IFORK_Q(tip) != 0) && (tip->i_d.di_anextents > 0)) &&
335 (tip->i_d.di_aformat != XFS_DINODE_FMT_LOCAL)) {
336 error = xfs_bmap_count_blocks(tp, tip, XFS_ATTR_FORK,
337 &taforkblks);
338 if (error)
339 goto out_trans_cancel;
340 }
341
342 /*
343 * Swap the data forks of the inodes
344 */
345 ifp = &ip->i_df;
346 tifp = &tip->i_df;
347 *tempifp = *ifp; /* struct copy */
348 *ifp = *tifp; /* struct copy */
349 *tifp = *tempifp; /* struct copy */
350
351 /*
352 * Fix the in-memory data fork values that are dependent on the fork
353 * offset in the inode. We can't assume they remain the same as attr2
354 * has dynamic fork offsets.
355 */
356 ifp->if_ext_max = XFS_IFORK_SIZE(ip, XFS_DATA_FORK) /
357 (uint)sizeof(xfs_bmbt_rec_t);
358 tifp->if_ext_max = XFS_IFORK_SIZE(tip, XFS_DATA_FORK) /
359 (uint)sizeof(xfs_bmbt_rec_t);
360
361 /*
362 * Fix the on-disk inode values
363 */
364 tmp = (__uint64_t)ip->i_d.di_nblocks;
365 ip->i_d.di_nblocks = tip->i_d.di_nblocks - taforkblks + aforkblks;
366 tip->i_d.di_nblocks = tmp + taforkblks - aforkblks;
367
368 tmp = (__uint64_t) ip->i_d.di_nextents;
369 ip->i_d.di_nextents = tip->i_d.di_nextents;
370 tip->i_d.di_nextents = tmp;
371
372 tmp = (__uint64_t) ip->i_d.di_format;
373 ip->i_d.di_format = tip->i_d.di_format;
374 tip->i_d.di_format = tmp;
375
376 /*
377 * The extents in the source inode could still contain speculative
378 * preallocation beyond EOF (e.g. the file is open but not modified
379 * while defrag is in progress). In that case, we need to copy over the
380 * number of delalloc blocks the data fork in the source inode is
381 * tracking beyond EOF so that when the fork is truncated away when the
382 * temporary inode is unlinked we don't underrun the i_delayed_blks
383 * counter on that inode.
384 */
385 ASSERT(tip->i_delayed_blks == 0);
386 tip->i_delayed_blks = ip->i_delayed_blks;
387 ip->i_delayed_blks = 0;
388
389 ilf_fields = XFS_ILOG_CORE;
390
391 switch(ip->i_d.di_format) {
392 case XFS_DINODE_FMT_EXTENTS:
393 /* If the extents fit in the inode, fix the
394 * pointer. Otherwise it's already NULL or
395 * pointing to the extent.
396 */
397 if (ip->i_d.di_nextents <= XFS_INLINE_EXTS) {
398 ifp->if_u1.if_extents =
399 ifp->if_u2.if_inline_ext;
400 }
401 ilf_fields |= XFS_ILOG_DEXT;
402 break;
403 case XFS_DINODE_FMT_BTREE:
404 ilf_fields |= XFS_ILOG_DBROOT;
405 break;
406 }
407
408 tilf_fields = XFS_ILOG_CORE;
409
410 switch(tip->i_d.di_format) {
411 case XFS_DINODE_FMT_EXTENTS:
412 /* If the extents fit in the inode, fix the
413 * pointer. Otherwise it's already NULL or
414 * pointing to the extent.
415 */
416 if (tip->i_d.di_nextents <= XFS_INLINE_EXTS) {
417 tifp->if_u1.if_extents =
418 tifp->if_u2.if_inline_ext;
419 }
420 tilf_fields |= XFS_ILOG_DEXT;
421 break;
422 case XFS_DINODE_FMT_BTREE:
423 tilf_fields |= XFS_ILOG_DBROOT;
424 break;
425 }
426
427
428 xfs_trans_ijoin_ref(tp, ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
429 xfs_trans_ijoin_ref(tp, tip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
430
431 xfs_trans_log_inode(tp, ip, ilf_fields);
432 xfs_trans_log_inode(tp, tip, tilf_fields);
433
434 /*
435 * If this is a synchronous mount, make sure that the
436 * transaction goes to disk before returning to the user.
437 */
438 if (mp->m_flags & XFS_MOUNT_WSYNC)
439 xfs_trans_set_sync(tp);
440
441 error = xfs_trans_commit(tp, XFS_TRANS_SWAPEXT);
442
443 trace_xfs_swap_extent_after(ip, 0);
444 trace_xfs_swap_extent_after(tip, 1);
445out:
446 kmem_free(tempifp);
447 return error;
448
449out_unlock:
450 xfs_iunlock(ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
451 xfs_iunlock(tip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL);
452 goto out;
453
454out_trans_cancel:
455 xfs_trans_cancel(tp, 0);
456 goto out_unlock;
457}