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