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