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xfs: use generic Posix ACL code
[deliverable/linux.git] / fs / xfs / linux-2.6 / xfs_lrw.c
1 /*
2 * Copyright (c) 2000-2003,2005 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_bit.h"
21 #include "xfs_log.h"
22 #include "xfs_inum.h"
23 #include "xfs_trans.h"
24 #include "xfs_sb.h"
25 #include "xfs_ag.h"
26 #include "xfs_dir2.h"
27 #include "xfs_alloc.h"
28 #include "xfs_dmapi.h"
29 #include "xfs_quota.h"
30 #include "xfs_mount.h"
31 #include "xfs_bmap_btree.h"
32 #include "xfs_alloc_btree.h"
33 #include "xfs_ialloc_btree.h"
34 #include "xfs_dir2_sf.h"
35 #include "xfs_attr_sf.h"
36 #include "xfs_dinode.h"
37 #include "xfs_inode.h"
38 #include "xfs_bmap.h"
39 #include "xfs_btree.h"
40 #include "xfs_ialloc.h"
41 #include "xfs_rtalloc.h"
42 #include "xfs_error.h"
43 #include "xfs_itable.h"
44 #include "xfs_rw.h"
45 #include "xfs_attr.h"
46 #include "xfs_inode_item.h"
47 #include "xfs_buf_item.h"
48 #include "xfs_utils.h"
49 #include "xfs_iomap.h"
50 #include "xfs_vnodeops.h"
51
52 #include <linux/capability.h>
53 #include <linux/writeback.h>
54
55
56 #if defined(XFS_RW_TRACE)
57 void
58 xfs_rw_enter_trace(
59 int tag,
60 xfs_inode_t *ip,
61 void *data,
62 size_t segs,
63 loff_t offset,
64 int ioflags)
65 {
66 if (ip->i_rwtrace == NULL)
67 return;
68 ktrace_enter(ip->i_rwtrace,
69 (void *)(unsigned long)tag,
70 (void *)ip,
71 (void *)((unsigned long)((ip->i_d.di_size >> 32) & 0xffffffff)),
72 (void *)((unsigned long)(ip->i_d.di_size & 0xffffffff)),
73 (void *)data,
74 (void *)((unsigned long)segs),
75 (void *)((unsigned long)((offset >> 32) & 0xffffffff)),
76 (void *)((unsigned long)(offset & 0xffffffff)),
77 (void *)((unsigned long)ioflags),
78 (void *)((unsigned long)((ip->i_new_size >> 32) & 0xffffffff)),
79 (void *)((unsigned long)(ip->i_new_size & 0xffffffff)),
80 (void *)((unsigned long)current_pid()),
81 (void *)NULL,
82 (void *)NULL,
83 (void *)NULL,
84 (void *)NULL);
85 }
86
87 void
88 xfs_inval_cached_trace(
89 xfs_inode_t *ip,
90 xfs_off_t offset,
91 xfs_off_t len,
92 xfs_off_t first,
93 xfs_off_t last)
94 {
95
96 if (ip->i_rwtrace == NULL)
97 return;
98 ktrace_enter(ip->i_rwtrace,
99 (void *)(__psint_t)XFS_INVAL_CACHED,
100 (void *)ip,
101 (void *)((unsigned long)((offset >> 32) & 0xffffffff)),
102 (void *)((unsigned long)(offset & 0xffffffff)),
103 (void *)((unsigned long)((len >> 32) & 0xffffffff)),
104 (void *)((unsigned long)(len & 0xffffffff)),
105 (void *)((unsigned long)((first >> 32) & 0xffffffff)),
106 (void *)((unsigned long)(first & 0xffffffff)),
107 (void *)((unsigned long)((last >> 32) & 0xffffffff)),
108 (void *)((unsigned long)(last & 0xffffffff)),
109 (void *)((unsigned long)current_pid()),
110 (void *)NULL,
111 (void *)NULL,
112 (void *)NULL,
113 (void *)NULL,
114 (void *)NULL);
115 }
116 #endif
117
118 /*
119 * xfs_iozero
120 *
121 * xfs_iozero clears the specified range of buffer supplied,
122 * and marks all the affected blocks as valid and modified. If
123 * an affected block is not allocated, it will be allocated. If
124 * an affected block is not completely overwritten, and is not
125 * valid before the operation, it will be read from disk before
126 * being partially zeroed.
127 */
128 STATIC int
129 xfs_iozero(
130 struct xfs_inode *ip, /* inode */
131 loff_t pos, /* offset in file */
132 size_t count) /* size of data to zero */
133 {
134 struct page *page;
135 struct address_space *mapping;
136 int status;
137
138 mapping = VFS_I(ip)->i_mapping;
139 do {
140 unsigned offset, bytes;
141 void *fsdata;
142
143 offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */
144 bytes = PAGE_CACHE_SIZE - offset;
145 if (bytes > count)
146 bytes = count;
147
148 status = pagecache_write_begin(NULL, mapping, pos, bytes,
149 AOP_FLAG_UNINTERRUPTIBLE,
150 &page, &fsdata);
151 if (status)
152 break;
153
154 zero_user(page, offset, bytes);
155
156 status = pagecache_write_end(NULL, mapping, pos, bytes, bytes,
157 page, fsdata);
158 WARN_ON(status <= 0); /* can't return less than zero! */
159 pos += bytes;
160 count -= bytes;
161 status = 0;
162 } while (count);
163
164 return (-status);
165 }
166
167 ssize_t /* bytes read, or (-) error */
168 xfs_read(
169 xfs_inode_t *ip,
170 struct kiocb *iocb,
171 const struct iovec *iovp,
172 unsigned int segs,
173 loff_t *offset,
174 int ioflags)
175 {
176 struct file *file = iocb->ki_filp;
177 struct inode *inode = file->f_mapping->host;
178 xfs_mount_t *mp = ip->i_mount;
179 size_t size = 0;
180 ssize_t ret = 0;
181 xfs_fsize_t n;
182 unsigned long seg;
183
184
185 XFS_STATS_INC(xs_read_calls);
186
187 /* START copy & waste from filemap.c */
188 for (seg = 0; seg < segs; seg++) {
189 const struct iovec *iv = &iovp[seg];
190
191 /*
192 * If any segment has a negative length, or the cumulative
193 * length ever wraps negative then return -EINVAL.
194 */
195 size += iv->iov_len;
196 if (unlikely((ssize_t)(size|iv->iov_len) < 0))
197 return XFS_ERROR(-EINVAL);
198 }
199 /* END copy & waste from filemap.c */
200
201 if (unlikely(ioflags & IO_ISDIRECT)) {
202 xfs_buftarg_t *target =
203 XFS_IS_REALTIME_INODE(ip) ?
204 mp->m_rtdev_targp : mp->m_ddev_targp;
205 if ((*offset & target->bt_smask) ||
206 (size & target->bt_smask)) {
207 if (*offset == ip->i_size) {
208 return (0);
209 }
210 return -XFS_ERROR(EINVAL);
211 }
212 }
213
214 n = XFS_MAXIOFFSET(mp) - *offset;
215 if ((n <= 0) || (size == 0))
216 return 0;
217
218 if (n < size)
219 size = n;
220
221 if (XFS_FORCED_SHUTDOWN(mp))
222 return -EIO;
223
224 if (unlikely(ioflags & IO_ISDIRECT))
225 mutex_lock(&inode->i_mutex);
226 xfs_ilock(ip, XFS_IOLOCK_SHARED);
227
228 if (DM_EVENT_ENABLED(ip, DM_EVENT_READ) && !(ioflags & IO_INVIS)) {
229 int dmflags = FILP_DELAY_FLAG(file) | DM_SEM_FLAG_RD(ioflags);
230 int iolock = XFS_IOLOCK_SHARED;
231
232 ret = -XFS_SEND_DATA(mp, DM_EVENT_READ, ip, *offset, size,
233 dmflags, &iolock);
234 if (ret) {
235 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
236 if (unlikely(ioflags & IO_ISDIRECT))
237 mutex_unlock(&inode->i_mutex);
238 return ret;
239 }
240 }
241
242 if (unlikely(ioflags & IO_ISDIRECT)) {
243 if (inode->i_mapping->nrpages)
244 ret = -xfs_flushinval_pages(ip, (*offset & PAGE_CACHE_MASK),
245 -1, FI_REMAPF_LOCKED);
246 mutex_unlock(&inode->i_mutex);
247 if (ret) {
248 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
249 return ret;
250 }
251 }
252
253 xfs_rw_enter_trace(XFS_READ_ENTER, ip,
254 (void *)iovp, segs, *offset, ioflags);
255
256 iocb->ki_pos = *offset;
257 ret = generic_file_aio_read(iocb, iovp, segs, *offset);
258 if (ret == -EIOCBQUEUED && !(ioflags & IO_ISAIO))
259 ret = wait_on_sync_kiocb(iocb);
260 if (ret > 0)
261 XFS_STATS_ADD(xs_read_bytes, ret);
262
263 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
264 return ret;
265 }
266
267 ssize_t
268 xfs_splice_read(
269 xfs_inode_t *ip,
270 struct file *infilp,
271 loff_t *ppos,
272 struct pipe_inode_info *pipe,
273 size_t count,
274 int flags,
275 int ioflags)
276 {
277 xfs_mount_t *mp = ip->i_mount;
278 ssize_t ret;
279
280 XFS_STATS_INC(xs_read_calls);
281 if (XFS_FORCED_SHUTDOWN(ip->i_mount))
282 return -EIO;
283
284 xfs_ilock(ip, XFS_IOLOCK_SHARED);
285
286 if (DM_EVENT_ENABLED(ip, DM_EVENT_READ) && !(ioflags & IO_INVIS)) {
287 int iolock = XFS_IOLOCK_SHARED;
288 int error;
289
290 error = XFS_SEND_DATA(mp, DM_EVENT_READ, ip, *ppos, count,
291 FILP_DELAY_FLAG(infilp), &iolock);
292 if (error) {
293 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
294 return -error;
295 }
296 }
297 xfs_rw_enter_trace(XFS_SPLICE_READ_ENTER, ip,
298 pipe, count, *ppos, ioflags);
299 ret = generic_file_splice_read(infilp, ppos, pipe, count, flags);
300 if (ret > 0)
301 XFS_STATS_ADD(xs_read_bytes, ret);
302
303 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
304 return ret;
305 }
306
307 ssize_t
308 xfs_splice_write(
309 xfs_inode_t *ip,
310 struct pipe_inode_info *pipe,
311 struct file *outfilp,
312 loff_t *ppos,
313 size_t count,
314 int flags,
315 int ioflags)
316 {
317 xfs_mount_t *mp = ip->i_mount;
318 ssize_t ret;
319 struct inode *inode = outfilp->f_mapping->host;
320 xfs_fsize_t isize, new_size;
321
322 XFS_STATS_INC(xs_write_calls);
323 if (XFS_FORCED_SHUTDOWN(ip->i_mount))
324 return -EIO;
325
326 xfs_ilock(ip, XFS_IOLOCK_EXCL);
327
328 if (DM_EVENT_ENABLED(ip, DM_EVENT_WRITE) && !(ioflags & IO_INVIS)) {
329 int iolock = XFS_IOLOCK_EXCL;
330 int error;
331
332 error = XFS_SEND_DATA(mp, DM_EVENT_WRITE, ip, *ppos, count,
333 FILP_DELAY_FLAG(outfilp), &iolock);
334 if (error) {
335 xfs_iunlock(ip, XFS_IOLOCK_EXCL);
336 return -error;
337 }
338 }
339
340 new_size = *ppos + count;
341
342 xfs_ilock(ip, XFS_ILOCK_EXCL);
343 if (new_size > ip->i_size)
344 ip->i_new_size = new_size;
345 xfs_iunlock(ip, XFS_ILOCK_EXCL);
346
347 xfs_rw_enter_trace(XFS_SPLICE_WRITE_ENTER, ip,
348 pipe, count, *ppos, ioflags);
349 ret = generic_file_splice_write(pipe, outfilp, ppos, count, flags);
350 if (ret > 0)
351 XFS_STATS_ADD(xs_write_bytes, ret);
352
353 isize = i_size_read(inode);
354 if (unlikely(ret < 0 && ret != -EFAULT && *ppos > isize))
355 *ppos = isize;
356
357 if (*ppos > ip->i_size) {
358 xfs_ilock(ip, XFS_ILOCK_EXCL);
359 if (*ppos > ip->i_size)
360 ip->i_size = *ppos;
361 xfs_iunlock(ip, XFS_ILOCK_EXCL);
362 }
363
364 if (ip->i_new_size) {
365 xfs_ilock(ip, XFS_ILOCK_EXCL);
366 ip->i_new_size = 0;
367 if (ip->i_d.di_size > ip->i_size)
368 ip->i_d.di_size = ip->i_size;
369 xfs_iunlock(ip, XFS_ILOCK_EXCL);
370 }
371 xfs_iunlock(ip, XFS_IOLOCK_EXCL);
372 return ret;
373 }
374
375 /*
376 * This routine is called to handle zeroing any space in the last
377 * block of the file that is beyond the EOF. We do this since the
378 * size is being increased without writing anything to that block
379 * and we don't want anyone to read the garbage on the disk.
380 */
381 STATIC int /* error (positive) */
382 xfs_zero_last_block(
383 xfs_inode_t *ip,
384 xfs_fsize_t offset,
385 xfs_fsize_t isize)
386 {
387 xfs_fileoff_t last_fsb;
388 xfs_mount_t *mp = ip->i_mount;
389 int nimaps;
390 int zero_offset;
391 int zero_len;
392 int error = 0;
393 xfs_bmbt_irec_t imap;
394
395 ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
396
397 zero_offset = XFS_B_FSB_OFFSET(mp, isize);
398 if (zero_offset == 0) {
399 /*
400 * There are no extra bytes in the last block on disk to
401 * zero, so return.
402 */
403 return 0;
404 }
405
406 last_fsb = XFS_B_TO_FSBT(mp, isize);
407 nimaps = 1;
408 error = xfs_bmapi(NULL, ip, last_fsb, 1, 0, NULL, 0, &imap,
409 &nimaps, NULL, NULL);
410 if (error) {
411 return error;
412 }
413 ASSERT(nimaps > 0);
414 /*
415 * If the block underlying isize is just a hole, then there
416 * is nothing to zero.
417 */
418 if (imap.br_startblock == HOLESTARTBLOCK) {
419 return 0;
420 }
421 /*
422 * Zero the part of the last block beyond the EOF, and write it
423 * out sync. We need to drop the ilock while we do this so we
424 * don't deadlock when the buffer cache calls back to us.
425 */
426 xfs_iunlock(ip, XFS_ILOCK_EXCL);
427
428 zero_len = mp->m_sb.sb_blocksize - zero_offset;
429 if (isize + zero_len > offset)
430 zero_len = offset - isize;
431 error = xfs_iozero(ip, isize, zero_len);
432
433 xfs_ilock(ip, XFS_ILOCK_EXCL);
434 ASSERT(error >= 0);
435 return error;
436 }
437
438 /*
439 * Zero any on disk space between the current EOF and the new,
440 * larger EOF. This handles the normal case of zeroing the remainder
441 * of the last block in the file and the unusual case of zeroing blocks
442 * out beyond the size of the file. This second case only happens
443 * with fixed size extents and when the system crashes before the inode
444 * size was updated but after blocks were allocated. If fill is set,
445 * then any holes in the range are filled and zeroed. If not, the holes
446 * are left alone as holes.
447 */
448
449 int /* error (positive) */
450 xfs_zero_eof(
451 xfs_inode_t *ip,
452 xfs_off_t offset, /* starting I/O offset */
453 xfs_fsize_t isize) /* current inode size */
454 {
455 xfs_mount_t *mp = ip->i_mount;
456 xfs_fileoff_t start_zero_fsb;
457 xfs_fileoff_t end_zero_fsb;
458 xfs_fileoff_t zero_count_fsb;
459 xfs_fileoff_t last_fsb;
460 xfs_fileoff_t zero_off;
461 xfs_fsize_t zero_len;
462 int nimaps;
463 int error = 0;
464 xfs_bmbt_irec_t imap;
465
466 ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_IOLOCK_EXCL));
467 ASSERT(offset > isize);
468
469 /*
470 * First handle zeroing the block on which isize resides.
471 * We only zero a part of that block so it is handled specially.
472 */
473 error = xfs_zero_last_block(ip, offset, isize);
474 if (error) {
475 ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_IOLOCK_EXCL));
476 return error;
477 }
478
479 /*
480 * Calculate the range between the new size and the old
481 * where blocks needing to be zeroed may exist. To get the
482 * block where the last byte in the file currently resides,
483 * we need to subtract one from the size and truncate back
484 * to a block boundary. We subtract 1 in case the size is
485 * exactly on a block boundary.
486 */
487 last_fsb = isize ? XFS_B_TO_FSBT(mp, isize - 1) : (xfs_fileoff_t)-1;
488 start_zero_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)isize);
489 end_zero_fsb = XFS_B_TO_FSBT(mp, offset - 1);
490 ASSERT((xfs_sfiloff_t)last_fsb < (xfs_sfiloff_t)start_zero_fsb);
491 if (last_fsb == end_zero_fsb) {
492 /*
493 * The size was only incremented on its last block.
494 * We took care of that above, so just return.
495 */
496 return 0;
497 }
498
499 ASSERT(start_zero_fsb <= end_zero_fsb);
500 while (start_zero_fsb <= end_zero_fsb) {
501 nimaps = 1;
502 zero_count_fsb = end_zero_fsb - start_zero_fsb + 1;
503 error = xfs_bmapi(NULL, ip, start_zero_fsb, zero_count_fsb,
504 0, NULL, 0, &imap, &nimaps, NULL, NULL);
505 if (error) {
506 ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_IOLOCK_EXCL));
507 return error;
508 }
509 ASSERT(nimaps > 0);
510
511 if (imap.br_state == XFS_EXT_UNWRITTEN ||
512 imap.br_startblock == HOLESTARTBLOCK) {
513 /*
514 * This loop handles initializing pages that were
515 * partially initialized by the code below this
516 * loop. It basically zeroes the part of the page
517 * that sits on a hole and sets the page as P_HOLE
518 * and calls remapf if it is a mapped file.
519 */
520 start_zero_fsb = imap.br_startoff + imap.br_blockcount;
521 ASSERT(start_zero_fsb <= (end_zero_fsb + 1));
522 continue;
523 }
524
525 /*
526 * There are blocks we need to zero.
527 * Drop the inode lock while we're doing the I/O.
528 * We'll still have the iolock to protect us.
529 */
530 xfs_iunlock(ip, XFS_ILOCK_EXCL);
531
532 zero_off = XFS_FSB_TO_B(mp, start_zero_fsb);
533 zero_len = XFS_FSB_TO_B(mp, imap.br_blockcount);
534
535 if ((zero_off + zero_len) > offset)
536 zero_len = offset - zero_off;
537
538 error = xfs_iozero(ip, zero_off, zero_len);
539 if (error) {
540 goto out_lock;
541 }
542
543 start_zero_fsb = imap.br_startoff + imap.br_blockcount;
544 ASSERT(start_zero_fsb <= (end_zero_fsb + 1));
545
546 xfs_ilock(ip, XFS_ILOCK_EXCL);
547 }
548
549 return 0;
550
551 out_lock:
552 xfs_ilock(ip, XFS_ILOCK_EXCL);
553 ASSERT(error >= 0);
554 return error;
555 }
556
557 ssize_t /* bytes written, or (-) error */
558 xfs_write(
559 struct xfs_inode *xip,
560 struct kiocb *iocb,
561 const struct iovec *iovp,
562 unsigned int nsegs,
563 loff_t *offset,
564 int ioflags)
565 {
566 struct file *file = iocb->ki_filp;
567 struct address_space *mapping = file->f_mapping;
568 struct inode *inode = mapping->host;
569 unsigned long segs = nsegs;
570 xfs_mount_t *mp;
571 ssize_t ret = 0, error = 0;
572 xfs_fsize_t isize, new_size;
573 int iolock;
574 int eventsent = 0;
575 size_t ocount = 0, count;
576 loff_t pos;
577 int need_i_mutex;
578
579 XFS_STATS_INC(xs_write_calls);
580
581 error = generic_segment_checks(iovp, &segs, &ocount, VERIFY_READ);
582 if (error)
583 return error;
584
585 count = ocount;
586 pos = *offset;
587
588 if (count == 0)
589 return 0;
590
591 mp = xip->i_mount;
592
593 xfs_wait_for_freeze(mp, SB_FREEZE_WRITE);
594
595 if (XFS_FORCED_SHUTDOWN(mp))
596 return -EIO;
597
598 relock:
599 if (ioflags & IO_ISDIRECT) {
600 iolock = XFS_IOLOCK_SHARED;
601 need_i_mutex = 0;
602 } else {
603 iolock = XFS_IOLOCK_EXCL;
604 need_i_mutex = 1;
605 mutex_lock(&inode->i_mutex);
606 }
607
608 xfs_ilock(xip, XFS_ILOCK_EXCL|iolock);
609
610 start:
611 error = -generic_write_checks(file, &pos, &count,
612 S_ISBLK(inode->i_mode));
613 if (error) {
614 xfs_iunlock(xip, XFS_ILOCK_EXCL|iolock);
615 goto out_unlock_mutex;
616 }
617
618 if ((DM_EVENT_ENABLED(xip, DM_EVENT_WRITE) &&
619 !(ioflags & IO_INVIS) && !eventsent)) {
620 int dmflags = FILP_DELAY_FLAG(file);
621
622 if (need_i_mutex)
623 dmflags |= DM_FLAGS_IMUX;
624
625 xfs_iunlock(xip, XFS_ILOCK_EXCL);
626 error = XFS_SEND_DATA(xip->i_mount, DM_EVENT_WRITE, xip,
627 pos, count, dmflags, &iolock);
628 if (error) {
629 goto out_unlock_internal;
630 }
631 xfs_ilock(xip, XFS_ILOCK_EXCL);
632 eventsent = 1;
633
634 /*
635 * The iolock was dropped and reacquired in XFS_SEND_DATA
636 * so we have to recheck the size when appending.
637 * We will only "goto start;" once, since having sent the
638 * event prevents another call to XFS_SEND_DATA, which is
639 * what allows the size to change in the first place.
640 */
641 if ((file->f_flags & O_APPEND) && pos != xip->i_size)
642 goto start;
643 }
644
645 if (ioflags & IO_ISDIRECT) {
646 xfs_buftarg_t *target =
647 XFS_IS_REALTIME_INODE(xip) ?
648 mp->m_rtdev_targp : mp->m_ddev_targp;
649
650 if ((pos & target->bt_smask) || (count & target->bt_smask)) {
651 xfs_iunlock(xip, XFS_ILOCK_EXCL|iolock);
652 return XFS_ERROR(-EINVAL);
653 }
654
655 if (!need_i_mutex && (mapping->nrpages || pos > xip->i_size)) {
656 xfs_iunlock(xip, XFS_ILOCK_EXCL|iolock);
657 iolock = XFS_IOLOCK_EXCL;
658 need_i_mutex = 1;
659 mutex_lock(&inode->i_mutex);
660 xfs_ilock(xip, XFS_ILOCK_EXCL|iolock);
661 goto start;
662 }
663 }
664
665 new_size = pos + count;
666 if (new_size > xip->i_size)
667 xip->i_new_size = new_size;
668
669 if (likely(!(ioflags & IO_INVIS)))
670 xfs_ichgtime(xip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
671
672 /*
673 * If the offset is beyond the size of the file, we have a couple
674 * of things to do. First, if there is already space allocated
675 * we need to either create holes or zero the disk or ...
676 *
677 * If there is a page where the previous size lands, we need
678 * to zero it out up to the new size.
679 */
680
681 if (pos > xip->i_size) {
682 error = xfs_zero_eof(xip, pos, xip->i_size);
683 if (error) {
684 xfs_iunlock(xip, XFS_ILOCK_EXCL);
685 goto out_unlock_internal;
686 }
687 }
688 xfs_iunlock(xip, XFS_ILOCK_EXCL);
689
690 /*
691 * If we're writing the file then make sure to clear the
692 * setuid and setgid bits if the process is not being run
693 * by root. This keeps people from modifying setuid and
694 * setgid binaries.
695 */
696
697 if (((xip->i_d.di_mode & S_ISUID) ||
698 ((xip->i_d.di_mode & (S_ISGID | S_IXGRP)) ==
699 (S_ISGID | S_IXGRP))) &&
700 !capable(CAP_FSETID)) {
701 error = xfs_write_clear_setuid(xip);
702 if (likely(!error))
703 error = -file_remove_suid(file);
704 if (unlikely(error)) {
705 goto out_unlock_internal;
706 }
707 }
708
709 /* We can write back this queue in page reclaim */
710 current->backing_dev_info = mapping->backing_dev_info;
711
712 if ((ioflags & IO_ISDIRECT)) {
713 if (mapping->nrpages) {
714 WARN_ON(need_i_mutex == 0);
715 xfs_inval_cached_trace(xip, pos, -1,
716 (pos & PAGE_CACHE_MASK), -1);
717 error = xfs_flushinval_pages(xip,
718 (pos & PAGE_CACHE_MASK),
719 -1, FI_REMAPF_LOCKED);
720 if (error)
721 goto out_unlock_internal;
722 }
723
724 if (need_i_mutex) {
725 /* demote the lock now the cached pages are gone */
726 xfs_ilock_demote(xip, XFS_IOLOCK_EXCL);
727 mutex_unlock(&inode->i_mutex);
728
729 iolock = XFS_IOLOCK_SHARED;
730 need_i_mutex = 0;
731 }
732
733 xfs_rw_enter_trace(XFS_DIOWR_ENTER, xip, (void *)iovp, segs,
734 *offset, ioflags);
735 ret = generic_file_direct_write(iocb, iovp,
736 &segs, pos, offset, count, ocount);
737
738 /*
739 * direct-io write to a hole: fall through to buffered I/O
740 * for completing the rest of the request.
741 */
742 if (ret >= 0 && ret != count) {
743 XFS_STATS_ADD(xs_write_bytes, ret);
744
745 pos += ret;
746 count -= ret;
747
748 ioflags &= ~IO_ISDIRECT;
749 xfs_iunlock(xip, iolock);
750 goto relock;
751 }
752 } else {
753 int enospc = 0;
754 ssize_t ret2 = 0;
755
756 write_retry:
757 xfs_rw_enter_trace(XFS_WRITE_ENTER, xip, (void *)iovp, segs,
758 *offset, ioflags);
759 ret2 = generic_file_buffered_write(iocb, iovp, segs,
760 pos, offset, count, ret);
761 /*
762 * if we just got an ENOSPC, flush the inode now we
763 * aren't holding any page locks and retry *once*
764 */
765 if (ret2 == -ENOSPC && !enospc) {
766 error = xfs_flush_pages(xip, 0, -1, 0, FI_NONE);
767 if (error)
768 goto out_unlock_internal;
769 enospc = 1;
770 goto write_retry;
771 }
772 ret = ret2;
773 }
774
775 current->backing_dev_info = NULL;
776
777 if (ret == -EIOCBQUEUED && !(ioflags & IO_ISAIO))
778 ret = wait_on_sync_kiocb(iocb);
779
780 isize = i_size_read(inode);
781 if (unlikely(ret < 0 && ret != -EFAULT && *offset > isize))
782 *offset = isize;
783
784 if (*offset > xip->i_size) {
785 xfs_ilock(xip, XFS_ILOCK_EXCL);
786 if (*offset > xip->i_size)
787 xip->i_size = *offset;
788 xfs_iunlock(xip, XFS_ILOCK_EXCL);
789 }
790
791 if (ret == -ENOSPC &&
792 DM_EVENT_ENABLED(xip, DM_EVENT_NOSPACE) && !(ioflags & IO_INVIS)) {
793 xfs_iunlock(xip, iolock);
794 if (need_i_mutex)
795 mutex_unlock(&inode->i_mutex);
796 error = XFS_SEND_NAMESP(xip->i_mount, DM_EVENT_NOSPACE, xip,
797 DM_RIGHT_NULL, xip, DM_RIGHT_NULL, NULL, NULL,
798 0, 0, 0); /* Delay flag intentionally unused */
799 if (need_i_mutex)
800 mutex_lock(&inode->i_mutex);
801 xfs_ilock(xip, iolock);
802 if (error)
803 goto out_unlock_internal;
804 goto start;
805 }
806
807 error = -ret;
808 if (ret <= 0)
809 goto out_unlock_internal;
810
811 XFS_STATS_ADD(xs_write_bytes, ret);
812
813 /* Handle various SYNC-type writes */
814 if ((file->f_flags & O_SYNC) || IS_SYNC(inode)) {
815 int error2;
816
817 xfs_iunlock(xip, iolock);
818 if (need_i_mutex)
819 mutex_unlock(&inode->i_mutex);
820 error2 = sync_page_range(inode, mapping, pos, ret);
821 if (!error)
822 error = error2;
823 if (need_i_mutex)
824 mutex_lock(&inode->i_mutex);
825 xfs_ilock(xip, iolock);
826 error2 = xfs_write_sync_logforce(mp, xip);
827 if (!error)
828 error = error2;
829 }
830
831 out_unlock_internal:
832 if (xip->i_new_size) {
833 xfs_ilock(xip, XFS_ILOCK_EXCL);
834 xip->i_new_size = 0;
835 /*
836 * If this was a direct or synchronous I/O that failed (such
837 * as ENOSPC) then part of the I/O may have been written to
838 * disk before the error occured. In this case the on-disk
839 * file size may have been adjusted beyond the in-memory file
840 * size and now needs to be truncated back.
841 */
842 if (xip->i_d.di_size > xip->i_size)
843 xip->i_d.di_size = xip->i_size;
844 xfs_iunlock(xip, XFS_ILOCK_EXCL);
845 }
846 xfs_iunlock(xip, iolock);
847 out_unlock_mutex:
848 if (need_i_mutex)
849 mutex_unlock(&inode->i_mutex);
850 return -error;
851 }
852
853 /*
854 * All xfs metadata buffers except log state machine buffers
855 * get this attached as their b_bdstrat callback function.
856 * This is so that we can catch a buffer
857 * after prematurely unpinning it to forcibly shutdown the filesystem.
858 */
859 int
860 xfs_bdstrat_cb(struct xfs_buf *bp)
861 {
862 if (XFS_FORCED_SHUTDOWN(bp->b_mount)) {
863 xfs_buftrace("XFS__BDSTRAT IOERROR", bp);
864 /*
865 * Metadata write that didn't get logged but
866 * written delayed anyway. These aren't associated
867 * with a transaction, and can be ignored.
868 */
869 if (XFS_BUF_IODONE_FUNC(bp) == NULL &&
870 (XFS_BUF_ISREAD(bp)) == 0)
871 return (xfs_bioerror_relse(bp));
872 else
873 return (xfs_bioerror(bp));
874 }
875
876 xfs_buf_iorequest(bp);
877 return 0;
878 }
879
880 /*
881 * Wrapper around bdstrat so that we can stop data from going to disk in case
882 * we are shutting down the filesystem. Typically user data goes thru this
883 * path; one of the exceptions is the superblock.
884 */
885 void
886 xfsbdstrat(
887 struct xfs_mount *mp,
888 struct xfs_buf *bp)
889 {
890 ASSERT(mp);
891 if (!XFS_FORCED_SHUTDOWN(mp)) {
892 xfs_buf_iorequest(bp);
893 return;
894 }
895
896 xfs_buftrace("XFSBDSTRAT IOERROR", bp);
897 xfs_bioerror_relse(bp);
898 }
899
900 /*
901 * If the underlying (data/log/rt) device is readonly, there are some
902 * operations that cannot proceed.
903 */
904 int
905 xfs_dev_is_read_only(
906 xfs_mount_t *mp,
907 char *message)
908 {
909 if (xfs_readonly_buftarg(mp->m_ddev_targp) ||
910 xfs_readonly_buftarg(mp->m_logdev_targp) ||
911 (mp->m_rtdev_targp && xfs_readonly_buftarg(mp->m_rtdev_targp))) {
912 cmn_err(CE_NOTE,
913 "XFS: %s required on read-only device.", message);
914 cmn_err(CE_NOTE,
915 "XFS: write access unavailable, cannot proceed.");
916 return EROFS;
917 }
918 return 0;
919 }
Linux kernel - Deliverables
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