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Merge branch 'upstream' of git://lost.foo-projects.org/~ahkok/git/netdev-2.6 into...
[mirror_ubuntu-bionic-kernel.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_acl.h"
46 #include "xfs_cap.h"
47 #include "xfs_mac.h"
48 #include "xfs_attr.h"
49 #include "xfs_inode_item.h"
50 #include "xfs_buf_item.h"
51 #include "xfs_utils.h"
52 #include "xfs_iomap.h"
53
54 #include <linux/capability.h>
55 #include <linux/writeback.h>
56
57
58 #if defined(XFS_RW_TRACE)
59 void
60 xfs_rw_enter_trace(
61 int tag,
62 xfs_iocore_t *io,
63 void *data,
64 size_t segs,
65 loff_t offset,
66 int ioflags)
67 {
68 xfs_inode_t *ip = XFS_IO_INODE(io);
69
70 if (ip->i_rwtrace == NULL)
71 return;
72 ktrace_enter(ip->i_rwtrace,
73 (void *)(unsigned long)tag,
74 (void *)ip,
75 (void *)((unsigned long)((ip->i_d.di_size >> 32) & 0xffffffff)),
76 (void *)((unsigned long)(ip->i_d.di_size & 0xffffffff)),
77 (void *)data,
78 (void *)((unsigned long)segs),
79 (void *)((unsigned long)((offset >> 32) & 0xffffffff)),
80 (void *)((unsigned long)(offset & 0xffffffff)),
81 (void *)((unsigned long)ioflags),
82 (void *)((unsigned long)((io->io_new_size >> 32) & 0xffffffff)),
83 (void *)((unsigned long)(io->io_new_size & 0xffffffff)),
84 (void *)((unsigned long)current_pid()),
85 (void *)NULL,
86 (void *)NULL,
87 (void *)NULL,
88 (void *)NULL);
89 }
90
91 void
92 xfs_inval_cached_trace(
93 xfs_iocore_t *io,
94 xfs_off_t offset,
95 xfs_off_t len,
96 xfs_off_t first,
97 xfs_off_t last)
98 {
99 xfs_inode_t *ip = XFS_IO_INODE(io);
100
101 if (ip->i_rwtrace == NULL)
102 return;
103 ktrace_enter(ip->i_rwtrace,
104 (void *)(__psint_t)XFS_INVAL_CACHED,
105 (void *)ip,
106 (void *)((unsigned long)((offset >> 32) & 0xffffffff)),
107 (void *)((unsigned long)(offset & 0xffffffff)),
108 (void *)((unsigned long)((len >> 32) & 0xffffffff)),
109 (void *)((unsigned long)(len & 0xffffffff)),
110 (void *)((unsigned long)((first >> 32) & 0xffffffff)),
111 (void *)((unsigned long)(first & 0xffffffff)),
112 (void *)((unsigned long)((last >> 32) & 0xffffffff)),
113 (void *)((unsigned long)(last & 0xffffffff)),
114 (void *)((unsigned long)current_pid()),
115 (void *)NULL,
116 (void *)NULL,
117 (void *)NULL,
118 (void *)NULL,
119 (void *)NULL);
120 }
121 #endif
122
123 /*
124 * xfs_iozero
125 *
126 * xfs_iozero clears the specified range of buffer supplied,
127 * and marks all the affected blocks as valid and modified. If
128 * an affected block is not allocated, it will be allocated. If
129 * an affected block is not completely overwritten, and is not
130 * valid before the operation, it will be read from disk before
131 * being partially zeroed.
132 */
133 STATIC int
134 xfs_iozero(
135 struct inode *ip, /* inode */
136 loff_t pos, /* offset in file */
137 size_t count, /* size of data to zero */
138 loff_t end_size) /* max file size to set */
139 {
140 unsigned bytes;
141 struct page *page;
142 struct address_space *mapping;
143 char *kaddr;
144 int status;
145
146 mapping = ip->i_mapping;
147 do {
148 unsigned long index, offset;
149
150 offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */
151 index = pos >> PAGE_CACHE_SHIFT;
152 bytes = PAGE_CACHE_SIZE - offset;
153 if (bytes > count)
154 bytes = count;
155
156 status = -ENOMEM;
157 page = grab_cache_page(mapping, index);
158 if (!page)
159 break;
160
161 kaddr = kmap(page);
162 status = mapping->a_ops->prepare_write(NULL, page, offset,
163 offset + bytes);
164 if (status) {
165 goto unlock;
166 }
167
168 memset((void *) (kaddr + offset), 0, bytes);
169 flush_dcache_page(page);
170 status = mapping->a_ops->commit_write(NULL, page, offset,
171 offset + bytes);
172 if (!status) {
173 pos += bytes;
174 count -= bytes;
175 if (pos > i_size_read(ip))
176 i_size_write(ip, pos < end_size ? pos : end_size);
177 }
178
179 unlock:
180 kunmap(page);
181 unlock_page(page);
182 page_cache_release(page);
183 if (status)
184 break;
185 } while (count);
186
187 return (-status);
188 }
189
190 ssize_t /* bytes read, or (-) error */
191 xfs_read(
192 bhv_desc_t *bdp,
193 struct kiocb *iocb,
194 const struct iovec *iovp,
195 unsigned int segs,
196 loff_t *offset,
197 int ioflags,
198 cred_t *credp)
199 {
200 struct file *file = iocb->ki_filp;
201 struct inode *inode = file->f_mapping->host;
202 size_t size = 0;
203 ssize_t ret;
204 xfs_fsize_t n;
205 xfs_inode_t *ip;
206 xfs_mount_t *mp;
207 bhv_vnode_t *vp;
208 unsigned long seg;
209
210 ip = XFS_BHVTOI(bdp);
211 vp = BHV_TO_VNODE(bdp);
212 mp = ip->i_mount;
213
214 XFS_STATS_INC(xs_read_calls);
215
216 /* START copy & waste from filemap.c */
217 for (seg = 0; seg < segs; seg++) {
218 const struct iovec *iv = &iovp[seg];
219
220 /*
221 * If any segment has a negative length, or the cumulative
222 * length ever wraps negative then return -EINVAL.
223 */
224 size += iv->iov_len;
225 if (unlikely((ssize_t)(size|iv->iov_len) < 0))
226 return XFS_ERROR(-EINVAL);
227 }
228 /* END copy & waste from filemap.c */
229
230 if (unlikely(ioflags & IO_ISDIRECT)) {
231 xfs_buftarg_t *target =
232 (ip->i_d.di_flags & XFS_DIFLAG_REALTIME) ?
233 mp->m_rtdev_targp : mp->m_ddev_targp;
234 if ((*offset & target->bt_smask) ||
235 (size & target->bt_smask)) {
236 if (*offset == ip->i_d.di_size) {
237 return (0);
238 }
239 return -XFS_ERROR(EINVAL);
240 }
241 }
242
243 n = XFS_MAXIOFFSET(mp) - *offset;
244 if ((n <= 0) || (size == 0))
245 return 0;
246
247 if (n < size)
248 size = n;
249
250 if (XFS_FORCED_SHUTDOWN(mp))
251 return -EIO;
252
253 if (unlikely(ioflags & IO_ISDIRECT))
254 mutex_lock(&inode->i_mutex);
255 xfs_ilock(ip, XFS_IOLOCK_SHARED);
256
257 if (DM_EVENT_ENABLED(vp->v_vfsp, ip, DM_EVENT_READ) &&
258 !(ioflags & IO_INVIS)) {
259 bhv_vrwlock_t locktype = VRWLOCK_READ;
260 int dmflags = FILP_DELAY_FLAG(file) | DM_SEM_FLAG_RD(ioflags);
261
262 ret = -XFS_SEND_DATA(mp, DM_EVENT_READ,
263 BHV_TO_VNODE(bdp), *offset, size,
264 dmflags, &locktype);
265 if (ret) {
266 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
267 goto unlock_mutex;
268 }
269 }
270
271 if (unlikely((ioflags & IO_ISDIRECT) && VN_CACHED(vp)))
272 bhv_vop_flushinval_pages(vp, ctooff(offtoct(*offset)),
273 -1, FI_REMAPF_LOCKED);
274
275 xfs_rw_enter_trace(XFS_READ_ENTER, &ip->i_iocore,
276 (void *)iovp, segs, *offset, ioflags);
277 ret = __generic_file_aio_read(iocb, iovp, segs, offset);
278 if (ret == -EIOCBQUEUED && !(ioflags & IO_ISAIO))
279 ret = wait_on_sync_kiocb(iocb);
280 if (ret > 0)
281 XFS_STATS_ADD(xs_read_bytes, ret);
282
283 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
284
285 unlock_mutex:
286 if (unlikely(ioflags & IO_ISDIRECT))
287 mutex_unlock(&inode->i_mutex);
288 return ret;
289 }
290
291 ssize_t
292 xfs_sendfile(
293 bhv_desc_t *bdp,
294 struct file *filp,
295 loff_t *offset,
296 int ioflags,
297 size_t count,
298 read_actor_t actor,
299 void *target,
300 cred_t *credp)
301 {
302 xfs_inode_t *ip = XFS_BHVTOI(bdp);
303 xfs_mount_t *mp = ip->i_mount;
304 ssize_t ret;
305
306 XFS_STATS_INC(xs_read_calls);
307 if (XFS_FORCED_SHUTDOWN(mp))
308 return -EIO;
309
310 xfs_ilock(ip, XFS_IOLOCK_SHARED);
311
312 if (DM_EVENT_ENABLED(BHV_TO_VNODE(bdp)->v_vfsp, ip, DM_EVENT_READ) &&
313 (!(ioflags & IO_INVIS))) {
314 bhv_vrwlock_t locktype = VRWLOCK_READ;
315 int error;
316
317 error = XFS_SEND_DATA(mp, DM_EVENT_READ, BHV_TO_VNODE(bdp),
318 *offset, count,
319 FILP_DELAY_FLAG(filp), &locktype);
320 if (error) {
321 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
322 return -error;
323 }
324 }
325 xfs_rw_enter_trace(XFS_SENDFILE_ENTER, &ip->i_iocore,
326 (void *)(unsigned long)target, count, *offset, ioflags);
327 ret = generic_file_sendfile(filp, offset, count, actor, target);
328 if (ret > 0)
329 XFS_STATS_ADD(xs_read_bytes, ret);
330
331 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
332 return ret;
333 }
334
335 ssize_t
336 xfs_splice_read(
337 bhv_desc_t *bdp,
338 struct file *infilp,
339 loff_t *ppos,
340 struct pipe_inode_info *pipe,
341 size_t count,
342 int flags,
343 int ioflags,
344 cred_t *credp)
345 {
346 xfs_inode_t *ip = XFS_BHVTOI(bdp);
347 xfs_mount_t *mp = ip->i_mount;
348 ssize_t ret;
349
350 XFS_STATS_INC(xs_read_calls);
351 if (XFS_FORCED_SHUTDOWN(ip->i_mount))
352 return -EIO;
353
354 xfs_ilock(ip, XFS_IOLOCK_SHARED);
355
356 if (DM_EVENT_ENABLED(BHV_TO_VNODE(bdp)->v_vfsp, ip, DM_EVENT_READ) &&
357 (!(ioflags & IO_INVIS))) {
358 bhv_vrwlock_t locktype = VRWLOCK_READ;
359 int error;
360
361 error = XFS_SEND_DATA(mp, DM_EVENT_READ, BHV_TO_VNODE(bdp),
362 *ppos, count,
363 FILP_DELAY_FLAG(infilp), &locktype);
364 if (error) {
365 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
366 return -error;
367 }
368 }
369 xfs_rw_enter_trace(XFS_SPLICE_READ_ENTER, &ip->i_iocore,
370 pipe, count, *ppos, ioflags);
371 ret = generic_file_splice_read(infilp, ppos, pipe, count, flags);
372 if (ret > 0)
373 XFS_STATS_ADD(xs_read_bytes, ret);
374
375 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
376 return ret;
377 }
378
379 ssize_t
380 xfs_splice_write(
381 bhv_desc_t *bdp,
382 struct pipe_inode_info *pipe,
383 struct file *outfilp,
384 loff_t *ppos,
385 size_t count,
386 int flags,
387 int ioflags,
388 cred_t *credp)
389 {
390 xfs_inode_t *ip = XFS_BHVTOI(bdp);
391 xfs_mount_t *mp = ip->i_mount;
392 ssize_t ret;
393
394 XFS_STATS_INC(xs_write_calls);
395 if (XFS_FORCED_SHUTDOWN(ip->i_mount))
396 return -EIO;
397
398 xfs_ilock(ip, XFS_IOLOCK_EXCL);
399
400 if (DM_EVENT_ENABLED(BHV_TO_VNODE(bdp)->v_vfsp, ip, DM_EVENT_WRITE) &&
401 (!(ioflags & IO_INVIS))) {
402 bhv_vrwlock_t locktype = VRWLOCK_WRITE;
403 int error;
404
405 error = XFS_SEND_DATA(mp, DM_EVENT_WRITE, BHV_TO_VNODE(bdp),
406 *ppos, count,
407 FILP_DELAY_FLAG(outfilp), &locktype);
408 if (error) {
409 xfs_iunlock(ip, XFS_IOLOCK_EXCL);
410 return -error;
411 }
412 }
413 xfs_rw_enter_trace(XFS_SPLICE_WRITE_ENTER, &ip->i_iocore,
414 pipe, count, *ppos, ioflags);
415 ret = generic_file_splice_write(pipe, outfilp, ppos, count, flags);
416 if (ret > 0)
417 XFS_STATS_ADD(xs_write_bytes, ret);
418
419 xfs_iunlock(ip, XFS_IOLOCK_EXCL);
420 return ret;
421 }
422
423 /*
424 * This routine is called to handle zeroing any space in the last
425 * block of the file that is beyond the EOF. We do this since the
426 * size is being increased without writing anything to that block
427 * and we don't want anyone to read the garbage on the disk.
428 */
429 STATIC int /* error (positive) */
430 xfs_zero_last_block(
431 struct inode *ip,
432 xfs_iocore_t *io,
433 xfs_fsize_t isize,
434 xfs_fsize_t end_size)
435 {
436 xfs_fileoff_t last_fsb;
437 xfs_mount_t *mp = io->io_mount;
438 int nimaps;
439 int zero_offset;
440 int zero_len;
441 int error = 0;
442 xfs_bmbt_irec_t imap;
443 loff_t loff;
444
445 ASSERT(ismrlocked(io->io_lock, MR_UPDATE) != 0);
446
447 zero_offset = XFS_B_FSB_OFFSET(mp, isize);
448 if (zero_offset == 0) {
449 /*
450 * There are no extra bytes in the last block on disk to
451 * zero, so return.
452 */
453 return 0;
454 }
455
456 last_fsb = XFS_B_TO_FSBT(mp, isize);
457 nimaps = 1;
458 error = XFS_BMAPI(mp, NULL, io, last_fsb, 1, 0, NULL, 0, &imap,
459 &nimaps, NULL, NULL);
460 if (error) {
461 return error;
462 }
463 ASSERT(nimaps > 0);
464 /*
465 * If the block underlying isize is just a hole, then there
466 * is nothing to zero.
467 */
468 if (imap.br_startblock == HOLESTARTBLOCK) {
469 return 0;
470 }
471 /*
472 * Zero the part of the last block beyond the EOF, and write it
473 * out sync. We need to drop the ilock while we do this so we
474 * don't deadlock when the buffer cache calls back to us.
475 */
476 XFS_IUNLOCK(mp, io, XFS_ILOCK_EXCL| XFS_EXTSIZE_RD);
477
478 loff = XFS_FSB_TO_B(mp, last_fsb);
479 zero_len = mp->m_sb.sb_blocksize - zero_offset;
480 error = xfs_iozero(ip, loff + zero_offset, zero_len, end_size);
481
482 XFS_ILOCK(mp, io, XFS_ILOCK_EXCL|XFS_EXTSIZE_RD);
483 ASSERT(error >= 0);
484 return error;
485 }
486
487 /*
488 * Zero any on disk space between the current EOF and the new,
489 * larger EOF. This handles the normal case of zeroing the remainder
490 * of the last block in the file and the unusual case of zeroing blocks
491 * out beyond the size of the file. This second case only happens
492 * with fixed size extents and when the system crashes before the inode
493 * size was updated but after blocks were allocated. If fill is set,
494 * then any holes in the range are filled and zeroed. If not, the holes
495 * are left alone as holes.
496 */
497
498 int /* error (positive) */
499 xfs_zero_eof(
500 bhv_vnode_t *vp,
501 xfs_iocore_t *io,
502 xfs_off_t offset, /* starting I/O offset */
503 xfs_fsize_t isize, /* current inode size */
504 xfs_fsize_t end_size) /* terminal inode size */
505 {
506 struct inode *ip = vn_to_inode(vp);
507 xfs_fileoff_t start_zero_fsb;
508 xfs_fileoff_t end_zero_fsb;
509 xfs_fileoff_t zero_count_fsb;
510 xfs_fileoff_t last_fsb;
511 xfs_mount_t *mp = io->io_mount;
512 int nimaps;
513 int error = 0;
514 xfs_bmbt_irec_t imap;
515
516 ASSERT(ismrlocked(io->io_lock, MR_UPDATE));
517 ASSERT(ismrlocked(io->io_iolock, MR_UPDATE));
518 ASSERT(offset > isize);
519
520 /*
521 * First handle zeroing the block on which isize resides.
522 * We only zero a part of that block so it is handled specially.
523 */
524 error = xfs_zero_last_block(ip, io, isize, end_size);
525 if (error) {
526 ASSERT(ismrlocked(io->io_lock, MR_UPDATE));
527 ASSERT(ismrlocked(io->io_iolock, MR_UPDATE));
528 return error;
529 }
530
531 /*
532 * Calculate the range between the new size and the old
533 * where blocks needing to be zeroed may exist. To get the
534 * block where the last byte in the file currently resides,
535 * we need to subtract one from the size and truncate back
536 * to a block boundary. We subtract 1 in case the size is
537 * exactly on a block boundary.
538 */
539 last_fsb = isize ? XFS_B_TO_FSBT(mp, isize - 1) : (xfs_fileoff_t)-1;
540 start_zero_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)isize);
541 end_zero_fsb = XFS_B_TO_FSBT(mp, offset - 1);
542 ASSERT((xfs_sfiloff_t)last_fsb < (xfs_sfiloff_t)start_zero_fsb);
543 if (last_fsb == end_zero_fsb) {
544 /*
545 * The size was only incremented on its last block.
546 * We took care of that above, so just return.
547 */
548 return 0;
549 }
550
551 ASSERT(start_zero_fsb <= end_zero_fsb);
552 while (start_zero_fsb <= end_zero_fsb) {
553 nimaps = 1;
554 zero_count_fsb = end_zero_fsb - start_zero_fsb + 1;
555 error = XFS_BMAPI(mp, NULL, io, start_zero_fsb, zero_count_fsb,
556 0, NULL, 0, &imap, &nimaps, NULL, NULL);
557 if (error) {
558 ASSERT(ismrlocked(io->io_lock, MR_UPDATE));
559 ASSERT(ismrlocked(io->io_iolock, MR_UPDATE));
560 return error;
561 }
562 ASSERT(nimaps > 0);
563
564 if (imap.br_state == XFS_EXT_UNWRITTEN ||
565 imap.br_startblock == HOLESTARTBLOCK) {
566 /*
567 * This loop handles initializing pages that were
568 * partially initialized by the code below this
569 * loop. It basically zeroes the part of the page
570 * that sits on a hole and sets the page as P_HOLE
571 * and calls remapf if it is a mapped file.
572 */
573 start_zero_fsb = imap.br_startoff + imap.br_blockcount;
574 ASSERT(start_zero_fsb <= (end_zero_fsb + 1));
575 continue;
576 }
577
578 /*
579 * There are blocks we need to zero.
580 * Drop the inode lock while we're doing the I/O.
581 * We'll still have the iolock to protect us.
582 */
583 XFS_IUNLOCK(mp, io, XFS_ILOCK_EXCL|XFS_EXTSIZE_RD);
584
585 error = xfs_iozero(ip,
586 XFS_FSB_TO_B(mp, start_zero_fsb),
587 XFS_FSB_TO_B(mp, imap.br_blockcount),
588 end_size);
589 if (error) {
590 goto out_lock;
591 }
592
593 start_zero_fsb = imap.br_startoff + imap.br_blockcount;
594 ASSERT(start_zero_fsb <= (end_zero_fsb + 1));
595
596 XFS_ILOCK(mp, io, XFS_ILOCK_EXCL|XFS_EXTSIZE_RD);
597 }
598
599 return 0;
600
601 out_lock:
602
603 XFS_ILOCK(mp, io, XFS_ILOCK_EXCL|XFS_EXTSIZE_RD);
604 ASSERT(error >= 0);
605 return error;
606 }
607
608 ssize_t /* bytes written, or (-) error */
609 xfs_write(
610 bhv_desc_t *bdp,
611 struct kiocb *iocb,
612 const struct iovec *iovp,
613 unsigned int nsegs,
614 loff_t *offset,
615 int ioflags,
616 cred_t *credp)
617 {
618 struct file *file = iocb->ki_filp;
619 struct address_space *mapping = file->f_mapping;
620 struct inode *inode = mapping->host;
621 unsigned long segs = nsegs;
622 xfs_inode_t *xip;
623 xfs_mount_t *mp;
624 ssize_t ret = 0, error = 0;
625 xfs_fsize_t isize, new_size;
626 xfs_iocore_t *io;
627 bhv_vnode_t *vp;
628 unsigned long seg;
629 int iolock;
630 int eventsent = 0;
631 bhv_vrwlock_t locktype;
632 size_t ocount = 0, count;
633 loff_t pos;
634 int need_i_mutex = 1, need_flush = 0;
635
636 XFS_STATS_INC(xs_write_calls);
637
638 vp = BHV_TO_VNODE(bdp);
639 xip = XFS_BHVTOI(bdp);
640
641 for (seg = 0; seg < segs; seg++) {
642 const struct iovec *iv = &iovp[seg];
643
644 /*
645 * If any segment has a negative length, or the cumulative
646 * length ever wraps negative then return -EINVAL.
647 */
648 ocount += iv->iov_len;
649 if (unlikely((ssize_t)(ocount|iv->iov_len) < 0))
650 return -EINVAL;
651 if (access_ok(VERIFY_READ, iv->iov_base, iv->iov_len))
652 continue;
653 if (seg == 0)
654 return -EFAULT;
655 segs = seg;
656 ocount -= iv->iov_len; /* This segment is no good */
657 break;
658 }
659
660 count = ocount;
661 pos = *offset;
662
663 if (count == 0)
664 return 0;
665
666 io = &xip->i_iocore;
667 mp = io->io_mount;
668
669 vfs_wait_for_freeze(vp->v_vfsp, SB_FREEZE_WRITE);
670
671 if (XFS_FORCED_SHUTDOWN(mp))
672 return -EIO;
673
674 if (ioflags & IO_ISDIRECT) {
675 xfs_buftarg_t *target =
676 (xip->i_d.di_flags & XFS_DIFLAG_REALTIME) ?
677 mp->m_rtdev_targp : mp->m_ddev_targp;
678
679 if ((pos & target->bt_smask) || (count & target->bt_smask))
680 return XFS_ERROR(-EINVAL);
681
682 if (!VN_CACHED(vp) && pos < i_size_read(inode))
683 need_i_mutex = 0;
684
685 if (VN_CACHED(vp))
686 need_flush = 1;
687 }
688
689 relock:
690 if (need_i_mutex) {
691 iolock = XFS_IOLOCK_EXCL;
692 locktype = VRWLOCK_WRITE;
693
694 mutex_lock(&inode->i_mutex);
695 } else {
696 iolock = XFS_IOLOCK_SHARED;
697 locktype = VRWLOCK_WRITE_DIRECT;
698 }
699
700 xfs_ilock(xip, XFS_ILOCK_EXCL|iolock);
701
702 isize = i_size_read(inode);
703
704 if (file->f_flags & O_APPEND)
705 *offset = isize;
706
707 start:
708 error = -generic_write_checks(file, &pos, &count,
709 S_ISBLK(inode->i_mode));
710 if (error) {
711 xfs_iunlock(xip, XFS_ILOCK_EXCL|iolock);
712 goto out_unlock_mutex;
713 }
714
715 new_size = pos + count;
716 if (new_size > isize)
717 io->io_new_size = new_size;
718
719 if ((DM_EVENT_ENABLED(vp->v_vfsp, xip, DM_EVENT_WRITE) &&
720 !(ioflags & IO_INVIS) && !eventsent)) {
721 loff_t savedsize = pos;
722 int dmflags = FILP_DELAY_FLAG(file);
723
724 if (need_i_mutex)
725 dmflags |= DM_FLAGS_IMUX;
726
727 xfs_iunlock(xip, XFS_ILOCK_EXCL);
728 error = XFS_SEND_DATA(xip->i_mount, DM_EVENT_WRITE, vp,
729 pos, count,
730 dmflags, &locktype);
731 if (error) {
732 xfs_iunlock(xip, iolock);
733 goto out_unlock_mutex;
734 }
735 xfs_ilock(xip, XFS_ILOCK_EXCL);
736 eventsent = 1;
737
738 /*
739 * The iolock was dropped and reacquired in XFS_SEND_DATA
740 * so we have to recheck the size when appending.
741 * We will only "goto start;" once, since having sent the
742 * event prevents another call to XFS_SEND_DATA, which is
743 * what allows the size to change in the first place.
744 */
745 if ((file->f_flags & O_APPEND) && savedsize != isize) {
746 pos = isize = xip->i_d.di_size;
747 goto start;
748 }
749 }
750
751 if (likely(!(ioflags & IO_INVIS))) {
752 file_update_time(file);
753 xfs_ichgtime_fast(xip, inode,
754 XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
755 }
756
757 /*
758 * If the offset is beyond the size of the file, we have a couple
759 * of things to do. First, if there is already space allocated
760 * we need to either create holes or zero the disk or ...
761 *
762 * If there is a page where the previous size lands, we need
763 * to zero it out up to the new size.
764 */
765
766 if (pos > isize) {
767 error = xfs_zero_eof(BHV_TO_VNODE(bdp), io, pos,
768 isize, pos + count);
769 if (error) {
770 xfs_iunlock(xip, XFS_ILOCK_EXCL|iolock);
771 goto out_unlock_mutex;
772 }
773 }
774 xfs_iunlock(xip, XFS_ILOCK_EXCL);
775
776 /*
777 * If we're writing the file then make sure to clear the
778 * setuid and setgid bits if the process is not being run
779 * by root. This keeps people from modifying setuid and
780 * setgid binaries.
781 */
782
783 if (((xip->i_d.di_mode & S_ISUID) ||
784 ((xip->i_d.di_mode & (S_ISGID | S_IXGRP)) ==
785 (S_ISGID | S_IXGRP))) &&
786 !capable(CAP_FSETID)) {
787 error = xfs_write_clear_setuid(xip);
788 if (likely(!error))
789 error = -remove_suid(file->f_dentry);
790 if (unlikely(error)) {
791 xfs_iunlock(xip, iolock);
792 goto out_unlock_mutex;
793 }
794 }
795
796 retry:
797 /* We can write back this queue in page reclaim */
798 current->backing_dev_info = mapping->backing_dev_info;
799
800 if ((ioflags & IO_ISDIRECT)) {
801 if (need_flush) {
802 xfs_inval_cached_trace(io, pos, -1,
803 ctooff(offtoct(pos)), -1);
804 bhv_vop_flushinval_pages(vp, ctooff(offtoct(pos)),
805 -1, FI_REMAPF_LOCKED);
806 }
807
808 if (need_i_mutex) {
809 /* demote the lock now the cached pages are gone */
810 XFS_ILOCK_DEMOTE(mp, io, XFS_IOLOCK_EXCL);
811 mutex_unlock(&inode->i_mutex);
812
813 iolock = XFS_IOLOCK_SHARED;
814 locktype = VRWLOCK_WRITE_DIRECT;
815 need_i_mutex = 0;
816 }
817
818 xfs_rw_enter_trace(XFS_DIOWR_ENTER, io, (void *)iovp, segs,
819 *offset, ioflags);
820 ret = generic_file_direct_write(iocb, iovp,
821 &segs, pos, offset, count, ocount);
822
823 /*
824 * direct-io write to a hole: fall through to buffered I/O
825 * for completing the rest of the request.
826 */
827 if (ret >= 0 && ret != count) {
828 XFS_STATS_ADD(xs_write_bytes, ret);
829
830 pos += ret;
831 count -= ret;
832
833 need_i_mutex = 1;
834 ioflags &= ~IO_ISDIRECT;
835 xfs_iunlock(xip, iolock);
836 goto relock;
837 }
838 } else {
839 xfs_rw_enter_trace(XFS_WRITE_ENTER, io, (void *)iovp, segs,
840 *offset, ioflags);
841 ret = generic_file_buffered_write(iocb, iovp, segs,
842 pos, offset, count, ret);
843 }
844
845 current->backing_dev_info = NULL;
846
847 if (ret == -EIOCBQUEUED && !(ioflags & IO_ISAIO))
848 ret = wait_on_sync_kiocb(iocb);
849
850 if ((ret == -ENOSPC) &&
851 DM_EVENT_ENABLED(vp->v_vfsp, xip, DM_EVENT_NOSPACE) &&
852 !(ioflags & IO_INVIS)) {
853
854 xfs_rwunlock(bdp, locktype);
855 if (need_i_mutex)
856 mutex_unlock(&inode->i_mutex);
857 error = XFS_SEND_NAMESP(xip->i_mount, DM_EVENT_NOSPACE, vp,
858 DM_RIGHT_NULL, vp, DM_RIGHT_NULL, NULL, NULL,
859 0, 0, 0); /* Delay flag intentionally unused */
860 if (error)
861 goto out_nounlocks;
862 if (need_i_mutex)
863 mutex_lock(&inode->i_mutex);
864 xfs_rwlock(bdp, locktype);
865 pos = xip->i_d.di_size;
866 ret = 0;
867 goto retry;
868 }
869
870 isize = i_size_read(inode);
871 if (unlikely(ret < 0 && ret != -EFAULT && *offset > isize))
872 *offset = isize;
873
874 if (*offset > xip->i_d.di_size) {
875 xfs_ilock(xip, XFS_ILOCK_EXCL);
876 if (*offset > xip->i_d.di_size) {
877 xip->i_d.di_size = *offset;
878 i_size_write(inode, *offset);
879 xip->i_update_core = 1;
880 xip->i_update_size = 1;
881 }
882 xfs_iunlock(xip, XFS_ILOCK_EXCL);
883 }
884
885 error = -ret;
886 if (ret <= 0)
887 goto out_unlock_internal;
888
889 XFS_STATS_ADD(xs_write_bytes, ret);
890
891 /* Handle various SYNC-type writes */
892 if ((file->f_flags & O_SYNC) || IS_SYNC(inode)) {
893 error = xfs_write_sync_logforce(mp, xip);
894 if (error)
895 goto out_unlock_internal;
896
897 xfs_rwunlock(bdp, locktype);
898 if (need_i_mutex)
899 mutex_unlock(&inode->i_mutex);
900
901 error = sync_page_range(inode, mapping, pos, ret);
902 if (!error)
903 error = ret;
904 return error;
905 }
906
907 out_unlock_internal:
908 xfs_rwunlock(bdp, locktype);
909 out_unlock_mutex:
910 if (need_i_mutex)
911 mutex_unlock(&inode->i_mutex);
912 out_nounlocks:
913 return -error;
914 }
915
916 /*
917 * All xfs metadata buffers except log state machine buffers
918 * get this attached as their b_bdstrat callback function.
919 * This is so that we can catch a buffer
920 * after prematurely unpinning it to forcibly shutdown the filesystem.
921 */
922 int
923 xfs_bdstrat_cb(struct xfs_buf *bp)
924 {
925 xfs_mount_t *mp;
926
927 mp = XFS_BUF_FSPRIVATE3(bp, xfs_mount_t *);
928 if (!XFS_FORCED_SHUTDOWN(mp)) {
929 xfs_buf_iorequest(bp);
930 return 0;
931 } else {
932 xfs_buftrace("XFS__BDSTRAT IOERROR", bp);
933 /*
934 * Metadata write that didn't get logged but
935 * written delayed anyway. These aren't associated
936 * with a transaction, and can be ignored.
937 */
938 if (XFS_BUF_IODONE_FUNC(bp) == NULL &&
939 (XFS_BUF_ISREAD(bp)) == 0)
940 return (xfs_bioerror_relse(bp));
941 else
942 return (xfs_bioerror(bp));
943 }
944 }
945
946
947 int
948 xfs_bmap(bhv_desc_t *bdp,
949 xfs_off_t offset,
950 ssize_t count,
951 int flags,
952 xfs_iomap_t *iomapp,
953 int *niomaps)
954 {
955 xfs_inode_t *ip = XFS_BHVTOI(bdp);
956 xfs_iocore_t *io = &ip->i_iocore;
957
958 ASSERT((ip->i_d.di_mode & S_IFMT) == S_IFREG);
959 ASSERT(((ip->i_d.di_flags & XFS_DIFLAG_REALTIME) != 0) ==
960 ((ip->i_iocore.io_flags & XFS_IOCORE_RT) != 0));
961
962 return xfs_iomap(io, offset, count, flags, iomapp, niomaps);
963 }
964
965 /*
966 * Wrapper around bdstrat so that we can stop data
967 * from going to disk in case we are shutting down the filesystem.
968 * Typically user data goes thru this path; one of the exceptions
969 * is the superblock.
970 */
971 int
972 xfsbdstrat(
973 struct xfs_mount *mp,
974 struct xfs_buf *bp)
975 {
976 ASSERT(mp);
977 if (!XFS_FORCED_SHUTDOWN(mp)) {
978 /* Grio redirection would go here
979 * if (XFS_BUF_IS_GRIO(bp)) {
980 */
981
982 xfs_buf_iorequest(bp);
983 return 0;
984 }
985
986 xfs_buftrace("XFSBDSTRAT IOERROR", bp);
987 return (xfs_bioerror_relse(bp));
988 }
989
990 /*
991 * If the underlying (data/log/rt) device is readonly, there are some
992 * operations that cannot proceed.
993 */
994 int
995 xfs_dev_is_read_only(
996 xfs_mount_t *mp,
997 char *message)
998 {
999 if (xfs_readonly_buftarg(mp->m_ddev_targp) ||
1000 xfs_readonly_buftarg(mp->m_logdev_targp) ||
1001 (mp->m_rtdev_targp && xfs_readonly_buftarg(mp->m_rtdev_targp))) {
1002 cmn_err(CE_NOTE,
1003 "XFS: %s required on read-only device.", message);
1004 cmn_err(CE_NOTE,
1005 "XFS: write access unavailable, cannot proceed.");
1006 return EROFS;
1007 }
1008 return 0;
1009 }
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