1 /*
2 * Copyright (c) 2000-2003 Silicon Graphics, Inc. All Rights Reserved.
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms of version 2 of the GNU General Public License as
6 * published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it would be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
11 *
12 * Further, this software is distributed without any warranty that it is
13 * free of the rightful claim of any third person regarding infringement
14 * or the like. Any license provided herein, whether implied or
15 * otherwise, applies only to this software file. Patent licenses, if
16 * any, provided herein do not apply to combinations of this program with
17 * other software, or any other product whatsoever.
18 *
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, write the Free Software Foundation, Inc., 59
21 * Temple Place - Suite 330, Boston MA 02111-1307, USA.
22 *
23 * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
24 * Mountain View, CA 94043, or:
25 *
26 * http://www.sgi.com
27 *
28 * For further information regarding this notice, see:
29 *
30 * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
31 */
32 /*
33 * fs/xfs/linux/xfs_lrw.c (Linux Read Write stuff)
34 *
35 */
36
37 #include "xfs.h"
38
39 #include "xfs_fs.h"
40 #include "xfs_inum.h"
41 #include "xfs_log.h"
42 #include "xfs_trans.h"
43 #include "xfs_sb.h"
44 #include "xfs_ag.h"
45 #include "xfs_dir.h"
46 #include "xfs_dir2.h"
47 #include "xfs_alloc.h"
48 #include "xfs_dmapi.h"
49 #include "xfs_quota.h"
50 #include "xfs_mount.h"
51 #include "xfs_alloc_btree.h"
52 #include "xfs_bmap_btree.h"
53 #include "xfs_ialloc_btree.h"
54 #include "xfs_btree.h"
55 #include "xfs_ialloc.h"
56 #include "xfs_attr_sf.h"
57 #include "xfs_dir_sf.h"
58 #include "xfs_dir2_sf.h"
59 #include "xfs_dinode.h"
60 #include "xfs_inode.h"
61 #include "xfs_bmap.h"
62 #include "xfs_bit.h"
63 #include "xfs_rtalloc.h"
64 #include "xfs_error.h"
65 #include "xfs_itable.h"
66 #include "xfs_rw.h"
67 #include "xfs_refcache.h"
68 #include "xfs_acl.h"
69 #include "xfs_cap.h"
70 #include "xfs_mac.h"
71 #include "xfs_attr.h"
72 #include "xfs_inode_item.h"
73 #include "xfs_buf_item.h"
74 #include "xfs_utils.h"
75 #include "xfs_iomap.h"
76
77 #include <linux/capability.h>
78
79
80 #if defined(XFS_RW_TRACE)
81 void
xfs_rw_enter_trace(int tag,xfs_iocore_t * io,const char * buf,size_t size,loff_t offset,int ioflags)82 xfs_rw_enter_trace(
83 int tag,
84 xfs_iocore_t *io,
85 const char *buf,
86 size_t size,
87 loff_t offset,
88 int ioflags)
89 {
90 xfs_inode_t *ip = XFS_IO_INODE(io);
91
92 if (ip->i_rwtrace == NULL)
93 return;
94 ktrace_enter(ip->i_rwtrace,
95 (void *)(unsigned long)tag,
96 (void *)ip,
97 (void *)((unsigned long)((ip->i_d.di_size >> 32) & 0xffffffff)),
98 (void *)((unsigned long)(ip->i_d.di_size & 0xffffffff)),
99 (void *)(__psint_t)buf,
100 (void *)((unsigned long)size),
101 (void *)((unsigned long)((offset >> 32) & 0xffffffff)),
102 (void *)((unsigned long)(offset & 0xffffffff)),
103 (void *)((unsigned long)ioflags),
104 (void *)((unsigned long)((io->io_new_size >> 32) & 0xffffffff)),
105 (void *)((unsigned long)(io->io_new_size & 0xffffffff)),
106 (void *)NULL,
107 (void *)NULL,
108 (void *)NULL,
109 (void *)NULL,
110 (void *)NULL);
111 }
112
113 void
xfs_inval_cached_trace(xfs_iocore_t * io,xfs_off_t offset,xfs_off_t len,xfs_off_t first,xfs_off_t last)114 xfs_inval_cached_trace(
115 xfs_iocore_t *io,
116 xfs_off_t offset,
117 xfs_off_t len,
118 xfs_off_t first,
119 xfs_off_t last)
120 {
121 xfs_inode_t *ip = XFS_IO_INODE(io);
122
123 if (ip->i_rwtrace == NULL)
124 return;
125 ktrace_enter(ip->i_rwtrace,
126 (void *)(__psint_t)XFS_INVAL_CACHED,
127 (void *)ip,
128 (void *)((unsigned long)((offset >> 32) & 0xffffffff)),
129 (void *)((unsigned long)(offset & 0xffffffff)),
130 (void *)((unsigned long)((len >> 32) & 0xffffffff)),
131 (void *)((unsigned long)(len & 0xffffffff)),
132 (void *)((unsigned long)((first >> 32) & 0xffffffff)),
133 (void *)((unsigned long)(first & 0xffffffff)),
134 (void *)((unsigned long)((last >> 32) & 0xffffffff)),
135 (void *)((unsigned long)(last & 0xffffffff)),
136 (void *)NULL,
137 (void *)NULL,
138 (void *)NULL,
139 (void *)NULL,
140 (void *)NULL,
141 (void *)NULL);
142 }
143 #endif
144
145 /*
146 * xfs_iozero
147 *
148 * xfs_iozero clears the specified range of buffer supplied,
149 * and marks all the affected blocks as valid and modified. If
150 * an affected block is not allocated, it will be allocated. If
151 * an affected block is not completely overwritten, and is not
152 * valid before the operation, it will be read from disk before
153 * being partially zeroed.
154 */
155 STATIC int
xfs_iozero(struct inode * ip,loff_t pos,size_t count,loff_t end_size)156 xfs_iozero(
157 struct inode *ip, /* inode */
158 loff_t pos, /* offset in file */
159 size_t count, /* size of data to zero */
160 loff_t end_size) /* max file size to set */
161 {
162 unsigned bytes;
163 struct page *page;
164 struct address_space *mapping;
165 char *kaddr;
166 int status;
167
168 mapping = ip->i_mapping;
169 do {
170 unsigned long index, offset;
171
172 offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */
173 index = pos >> PAGE_CACHE_SHIFT;
174 bytes = PAGE_CACHE_SIZE - offset;
175 if (bytes > count)
176 bytes = count;
177
178 status = -ENOMEM;
179 page = grab_cache_page(mapping, index);
180 if (!page)
181 break;
182
183 kaddr = kmap(page);
184 status = mapping->a_ops->prepare_write(NULL, page, offset,
185 offset + bytes);
186 if (status) {
187 goto unlock;
188 }
189
190 memset((void *) (kaddr + offset), 0, bytes);
191 flush_dcache_page(page);
192 status = mapping->a_ops->commit_write(NULL, page, offset,
193 offset + bytes);
194 if (!status) {
195 pos += bytes;
196 count -= bytes;
197 if (pos > i_size_read(ip))
198 i_size_write(ip, pos < end_size ? pos : end_size);
199 }
200
201 unlock:
202 kunmap(page);
203 unlock_page(page);
204 page_cache_release(page);
205 if (status)
206 break;
207 } while (count);
208
209 return (-status);
210 }
211
212 /*
213 * xfs_inval_cached_pages
214 *
215 * This routine is responsible for keeping direct I/O and buffered I/O
216 * somewhat coherent. From here we make sure that we're at least
217 * temporarily holding the inode I/O lock exclusively and then call
218 * the page cache to flush and invalidate any cached pages. If there
219 * are no cached pages this routine will be very quick.
220 */
221 void
xfs_inval_cached_pages(vnode_t * vp,xfs_iocore_t * io,xfs_off_t offset,int write,int relock)222 xfs_inval_cached_pages(
223 vnode_t *vp,
224 xfs_iocore_t *io,
225 xfs_off_t offset,
226 int write,
227 int relock)
228 {
229 xfs_mount_t *mp;
230
231 if (!VN_CACHED(vp)) {
232 return;
233 }
234
235 mp = io->io_mount;
236
237 /*
238 * We need to get the I/O lock exclusively in order
239 * to safely invalidate pages and mappings.
240 */
241 if (relock) {
242 XFS_IUNLOCK(mp, io, XFS_IOLOCK_SHARED);
243 XFS_ILOCK(mp, io, XFS_IOLOCK_EXCL);
244 }
245
246 /* Writing beyond EOF creates a hole that must be zeroed */
247 if (write && (offset > XFS_SIZE(mp, io))) {
248 xfs_fsize_t isize;
249
250 XFS_ILOCK(mp, io, XFS_ILOCK_EXCL|XFS_EXTSIZE_RD);
251 isize = XFS_SIZE(mp, io);
252 if (offset > isize) {
253 xfs_zero_eof(vp, io, offset, isize, offset);
254 }
255 XFS_IUNLOCK(mp, io, XFS_ILOCK_EXCL|XFS_EXTSIZE_RD);
256 }
257
258 xfs_inval_cached_trace(io, offset, -1, ctooff(offtoct(offset)), -1);
259 VOP_FLUSHINVAL_PAGES(vp, ctooff(offtoct(offset)), -1, FI_REMAPF_LOCKED);
260 if (relock) {
261 XFS_ILOCK_DEMOTE(mp, io, XFS_IOLOCK_EXCL);
262 }
263 }
264
265 ssize_t /* bytes read, or (-) error */
xfs_read(bhv_desc_t * bdp,struct file * file,char * buf,size_t size,loff_t * offset,int ioflags,cred_t * credp)266 xfs_read(
267 bhv_desc_t *bdp,
268 struct file *file,
269 char *buf,
270 size_t size,
271 loff_t *offset,
272 int ioflags,
273 cred_t *credp)
274 {
275 ssize_t ret;
276 xfs_fsize_t n;
277 xfs_inode_t *ip;
278 xfs_mount_t *mp;
279
280 ip = XFS_BHVTOI(bdp);
281 mp = ip->i_mount;
282
283 XFS_STATS_INC(xs_read_calls);
284
285 if (unlikely(ioflags & IO_ISDIRECT)) {
286 if ((ssize_t)size < 0)
287 return -XFS_ERROR(EINVAL);
288 if (((__psint_t)buf & BBMASK) ||
289 (*offset & mp->m_blockmask) ||
290 (size & mp->m_blockmask)) {
291 if (*offset >= ip->i_d.di_size) {
292 return (0);
293 }
294 return -XFS_ERROR(EINVAL);
295 }
296 }
297
298 n = XFS_MAXIOFFSET(mp) - *offset;
299 if ((n <= 0) || (size == 0))
300 return 0;
301
302 if (n < size)
303 size = n;
304
305 if (XFS_FORCED_SHUTDOWN(mp)) {
306 return -EIO;
307 }
308
309 if (!(ioflags & IO_ISLOCKED))
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 int error;
315 vrwlock_t locktype = VRWLOCK_READ;
316 int dmflags = FILP_DELAY_FLAG(file) | DM_SEM_FLAG_RD(ioflags);
317
318 error = XFS_SEND_DATA(mp, DM_EVENT_READ, BHV_TO_VNODE(bdp), *offset, size,
319 dmflags, &locktype);
320 if (error) {
321 if (!(ioflags & IO_ISLOCKED))
322 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
323 return -error;
324 }
325 }
326
327 if (unlikely(ioflags & IO_ISDIRECT)) {
328 xfs_rw_enter_trace(XFS_DIORD_ENTER, &ip->i_iocore,
329 buf, size, *offset, ioflags);
330 ret = (*offset < ip->i_d.di_size) ?
331 do_generic_direct_read(file, buf, size, offset) : 0;
332 UPDATE_ATIME(file->f_dentry->d_inode);
333 } else {
334 xfs_rw_enter_trace(XFS_READ_ENTER, &ip->i_iocore,
335 buf, size, *offset, ioflags);
336 ret = generic_file_read(file, buf, size, offset);
337 }
338
339 if (ret > 0)
340 XFS_STATS_ADD(xs_read_bytes, ret);
341
342 if (!(ioflags & IO_ISLOCKED))
343 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
344
345 if (unlikely(ioflags & IO_INVIS)) {
346 /* generic_file_read updates the atime but we need to
347 * undo that because this I/O was supposed to be invisible.
348 */
349 struct inode *inode = LINVFS_GET_IP(BHV_TO_VNODE(bdp));
350 inode->i_atime = ip->i_d.di_atime.t_sec;
351 } else {
352 xfs_ichgtime(ip, XFS_ICHGTIME_ACC);
353 }
354
355 return ret;
356 }
357
358 /*
359 * This routine is called to handle zeroing any space in the last
360 * block of the file that is beyond the EOF. We do this since the
361 * size is being increased without writing anything to that block
362 * and we don't want anyone to read the garbage on the disk.
363 */
364 STATIC int /* error (positive) */
xfs_zero_last_block(struct inode * ip,xfs_iocore_t * io,xfs_off_t offset,xfs_fsize_t isize,xfs_fsize_t end_size)365 xfs_zero_last_block(
366 struct inode *ip,
367 xfs_iocore_t *io,
368 xfs_off_t offset,
369 xfs_fsize_t isize,
370 xfs_fsize_t end_size)
371 {
372 xfs_fileoff_t last_fsb;
373 xfs_mount_t *mp;
374 int nimaps;
375 int zero_offset;
376 int zero_len;
377 int isize_fsb_offset;
378 int error = 0;
379 xfs_bmbt_irec_t imap;
380 loff_t loff;
381 size_t lsize;
382
383 ASSERT(ismrlocked(io->io_lock, MR_UPDATE) != 0);
384 ASSERT(offset > isize);
385
386 mp = io->io_mount;
387
388 isize_fsb_offset = XFS_B_FSB_OFFSET(mp, isize);
389 if (isize_fsb_offset == 0) {
390 /*
391 * There are no extra bytes in the last block on disk to
392 * zero, so return.
393 */
394 return 0;
395 }
396
397 last_fsb = XFS_B_TO_FSBT(mp, isize);
398 nimaps = 1;
399 error = XFS_BMAPI(mp, NULL, io, last_fsb, 1, 0, NULL, 0, &imap,
400 &nimaps, NULL);
401 if (error) {
402 return error;
403 }
404 ASSERT(nimaps > 0);
405 /*
406 * If the block underlying isize is just a hole, then there
407 * is nothing to zero.
408 */
409 if (imap.br_startblock == HOLESTARTBLOCK) {
410 return 0;
411 }
412 /*
413 * Zero the part of the last block beyond the EOF, and write it
414 * out sync. We need to drop the ilock while we do this so we
415 * don't deadlock when the buffer cache calls back to us.
416 */
417 XFS_IUNLOCK(mp, io, XFS_ILOCK_EXCL| XFS_EXTSIZE_RD);
418 loff = XFS_FSB_TO_B(mp, last_fsb);
419 lsize = XFS_FSB_TO_B(mp, 1);
420
421 zero_offset = isize_fsb_offset;
422 zero_len = mp->m_sb.sb_blocksize - isize_fsb_offset;
423
424 error = xfs_iozero(ip, loff + zero_offset, zero_len, end_size);
425
426 XFS_ILOCK(mp, io, XFS_ILOCK_EXCL|XFS_EXTSIZE_RD);
427 ASSERT(error >= 0);
428 return error;
429 }
430
431 /*
432 * Zero any on disk space between the current EOF and the new,
433 * larger EOF. This handles the normal case of zeroing the remainder
434 * of the last block in the file and the unusual case of zeroing blocks
435 * out beyond the size of the file. This second case only happens
436 * with fixed size extents and when the system crashes before the inode
437 * size was updated but after blocks were allocated. If fill is set,
438 * then any holes in the range are filled and zeroed. If not, the holes
439 * are left alone as holes.
440 */
441
442 int /* error (positive) */
xfs_zero_eof(vnode_t * vp,xfs_iocore_t * io,xfs_off_t offset,xfs_fsize_t isize,xfs_fsize_t end_size)443 xfs_zero_eof(
444 vnode_t *vp,
445 xfs_iocore_t *io,
446 xfs_off_t offset, /* starting I/O offset */
447 xfs_fsize_t isize, /* current inode size */
448 xfs_fsize_t end_size) /* terminal inode size */
449 {
450 struct inode *ip = LINVFS_GET_IP(vp);
451 xfs_fileoff_t start_zero_fsb;
452 xfs_fileoff_t end_zero_fsb;
453 xfs_fileoff_t prev_zero_fsb;
454 xfs_fileoff_t zero_count_fsb;
455 xfs_fileoff_t last_fsb;
456 xfs_extlen_t buf_len_fsb;
457 xfs_extlen_t prev_zero_count;
458 xfs_mount_t *mp;
459 int nimaps;
460 int error = 0;
461 xfs_bmbt_irec_t imap;
462 loff_t loff;
463 size_t lsize;
464
465 ASSERT(ismrlocked(io->io_lock, MR_UPDATE));
466 ASSERT(ismrlocked(io->io_iolock, MR_UPDATE));
467
468 mp = io->io_mount;
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, io, offset, isize, end_size);
475 if (error) {
476 ASSERT(ismrlocked(io->io_lock, MR_UPDATE));
477 ASSERT(ismrlocked(io->io_iolock, MR_UPDATE));
478 return error;
479 }
480
481 /*
482 * Calculate the range between the new size and the old
483 * where blocks needing to be zeroed may exist. To get the
484 * block where the last byte in the file currently resides,
485 * we need to subtract one from the size and truncate back
486 * to a block boundary. We subtract 1 in case the size is
487 * exactly on a block boundary.
488 */
489 last_fsb = isize ? XFS_B_TO_FSBT(mp, isize - 1) : (xfs_fileoff_t)-1;
490 start_zero_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)isize);
491 end_zero_fsb = XFS_B_TO_FSBT(mp, offset - 1);
492 ASSERT((xfs_sfiloff_t)last_fsb < (xfs_sfiloff_t)start_zero_fsb);
493 if (last_fsb == end_zero_fsb) {
494 /*
495 * The size was only incremented on its last block.
496 * We took care of that above, so just return.
497 */
498 return 0;
499 }
500
501 ASSERT(start_zero_fsb <= end_zero_fsb);
502 prev_zero_fsb = NULLFILEOFF;
503 prev_zero_count = 0;
504 while (start_zero_fsb <= end_zero_fsb) {
505 nimaps = 1;
506 zero_count_fsb = end_zero_fsb - start_zero_fsb + 1;
507 error = XFS_BMAPI(mp, NULL, io, start_zero_fsb, zero_count_fsb,
508 0, NULL, 0, &imap, &nimaps, NULL);
509 if (error) {
510 ASSERT(ismrlocked(io->io_lock, MR_UPDATE));
511 ASSERT(ismrlocked(io->io_iolock, MR_UPDATE));
512 return error;
513 }
514 ASSERT(nimaps > 0);
515
516 if (imap.br_state == XFS_EXT_UNWRITTEN ||
517 imap.br_startblock == HOLESTARTBLOCK) {
518 /*
519 * This loop handles initializing pages that were
520 * partially initialized by the code below this
521 * loop. It basically zeroes the part of the page
522 * that sits on a hole and sets the page as P_HOLE
523 * and calls remapf if it is a mapped file.
524 */
525 prev_zero_fsb = NULLFILEOFF;
526 prev_zero_count = 0;
527 start_zero_fsb = imap.br_startoff +
528 imap.br_blockcount;
529 ASSERT(start_zero_fsb <= (end_zero_fsb + 1));
530 continue;
531 }
532
533 /*
534 * There are blocks in the range requested.
535 * Zero them a single write at a time. We actually
536 * don't zero the entire range returned if it is
537 * too big and simply loop around to get the rest.
538 * That is not the most efficient thing to do, but it
539 * is simple and this path should not be exercised often.
540 */
541 buf_len_fsb = XFS_FILBLKS_MIN(imap.br_blockcount,
542 mp->m_writeio_blocks << 8);
543 /*
544 * Drop the inode lock while we're doing the I/O.
545 * We'll still have the iolock to protect us.
546 */
547 XFS_IUNLOCK(mp, io, XFS_ILOCK_EXCL|XFS_EXTSIZE_RD);
548
549 loff = XFS_FSB_TO_B(mp, start_zero_fsb);
550 lsize = XFS_FSB_TO_B(mp, buf_len_fsb);
551
552 error = xfs_iozero(ip, loff, lsize, end_size);
553
554 if (error) {
555 goto out_lock;
556 }
557
558 prev_zero_fsb = start_zero_fsb;
559 prev_zero_count = buf_len_fsb;
560 start_zero_fsb = imap.br_startoff + buf_len_fsb;
561 ASSERT(start_zero_fsb <= (end_zero_fsb + 1));
562
563 XFS_ILOCK(mp, io, XFS_ILOCK_EXCL|XFS_EXTSIZE_RD);
564 }
565
566 return 0;
567
568 out_lock:
569
570 XFS_ILOCK(mp, io, XFS_ILOCK_EXCL|XFS_EXTSIZE_RD);
571 ASSERT(error >= 0);
572 return error;
573 }
574
575 ssize_t /* bytes written, or (-) error */
xfs_write(bhv_desc_t * bdp,struct file * file,const char * buf,size_t size,loff_t * offset,int ioflags,cred_t * credp)576 xfs_write(
577 bhv_desc_t *bdp,
578 struct file *file,
579 const char *buf,
580 size_t size,
581 loff_t *offset,
582 int ioflags,
583 cred_t *credp)
584 {
585 xfs_inode_t *xip;
586 xfs_mount_t *mp;
587 ssize_t ret;
588 int error = 0;
589 xfs_fsize_t isize, new_size;
590 xfs_fsize_t n, limit;
591 xfs_iocore_t *io;
592 vnode_t *vp;
593 int iolock;
594 int eventsent = 0;
595 vrwlock_t locktype;
596
597 XFS_STATS_INC(xs_write_calls);
598
599 vp = BHV_TO_VNODE(bdp);
600 xip = XFS_BHVTOI(bdp);
601
602 if (size == 0)
603 return 0;
604
605 io = &xip->i_iocore;
606 mp = io->io_mount;
607
608 fs_check_frozen(vp->v_vfsp, SB_FREEZE_WRITE);
609
610 if (XFS_FORCED_SHUTDOWN(xip->i_mount)) {
611 return -EIO;
612 }
613
614 if (unlikely(ioflags & IO_ISDIRECT)) {
615 if (((__psint_t)buf & BBMASK) ||
616 (*offset & mp->m_blockmask) ||
617 (size & mp->m_blockmask)) {
618 return XFS_ERROR(-EINVAL);
619 }
620 iolock = XFS_IOLOCK_SHARED;
621 locktype = VRWLOCK_WRITE_DIRECT;
622 } else {
623 iolock = XFS_IOLOCK_EXCL;
624 locktype = VRWLOCK_WRITE;
625 }
626
627 if (ioflags & IO_ISLOCKED)
628 iolock = 0;
629
630 xfs_ilock(xip, XFS_ILOCK_EXCL|iolock);
631
632 isize = xip->i_d.di_size;
633 limit = XFS_MAXIOFFSET(mp);
634
635 if (file->f_flags & O_APPEND)
636 *offset = isize;
637
638 start:
639 n = limit - *offset;
640 if (n <= 0) {
641 xfs_iunlock(xip, XFS_ILOCK_EXCL|iolock);
642 return -EFBIG;
643 }
644 if (n < size)
645 size = n;
646
647 new_size = *offset + size;
648 if (new_size > isize) {
649 io->io_new_size = new_size;
650 }
651
652 if ((DM_EVENT_ENABLED(vp->v_vfsp, xip, DM_EVENT_WRITE) &&
653 !(ioflags & IO_INVIS) && !eventsent)) {
654 loff_t savedsize = *offset;
655 int dmflags = FILP_DELAY_FLAG(file) | DM_SEM_FLAG_RD(ioflags);
656
657 xfs_iunlock(xip, XFS_ILOCK_EXCL);
658 error = XFS_SEND_DATA(xip->i_mount, DM_EVENT_WRITE, vp,
659 *offset, size,
660 dmflags, &locktype);
661 if (error) {
662 if (iolock) xfs_iunlock(xip, iolock);
663 return -error;
664 }
665 xfs_ilock(xip, XFS_ILOCK_EXCL);
666 eventsent = 1;
667
668 /*
669 * The iolock was dropped and reaquired in XFS_SEND_DATA
670 * so we have to recheck the size when appending.
671 * We will only "goto start;" once, since having sent the
672 * event prevents another call to XFS_SEND_DATA, which is
673 * what allows the size to change in the first place.
674 */
675 if ((file->f_flags & O_APPEND) &&
676 savedsize != xip->i_d.di_size) {
677 *offset = isize = xip->i_d.di_size;
678 goto start;
679 }
680 }
681
682 /*
683 * If the offset is beyond the size of the file, we have a couple
684 * of things to do. First, if there is already space allocated
685 * we need to either create holes or zero the disk or ...
686 *
687 * If there is a page where the previous size lands, we need
688 * to zero it out up to the new size.
689 */
690
691 if (!(ioflags & IO_ISDIRECT) && (*offset > isize && isize)) {
692 error = xfs_zero_eof(BHV_TO_VNODE(bdp), io, *offset,
693 isize, *offset + size);
694 if (error) {
695 xfs_iunlock(xip, XFS_ILOCK_EXCL|iolock);
696 return(-error);
697 }
698 }
699 xfs_iunlock(xip, XFS_ILOCK_EXCL);
700
701 /*
702 * If we're writing the file then make sure to clear the
703 * setuid and setgid bits if the process is not being run
704 * by root. This keeps people from modifying setuid and
705 * setgid binaries.
706 */
707
708 if (((xip->i_d.di_mode & S_ISUID) ||
709 ((xip->i_d.di_mode & (S_ISGID | S_IXGRP)) ==
710 (S_ISGID | S_IXGRP))) &&
711 !capable(CAP_FSETID)) {
712 error = xfs_write_clear_setuid(xip);
713 if (error) {
714 xfs_iunlock(xip, iolock);
715 return -error;
716 }
717 }
718
719
720 if ((ssize_t) size < 0) {
721 ret = -EINVAL;
722 goto error;
723 }
724
725 if (!access_ok(VERIFY_READ, buf, size)) {
726 ret = -EINVAL;
727 goto error;
728 }
729
730 retry:
731 if (unlikely(ioflags & IO_ISDIRECT)) {
732 xfs_inval_cached_pages(vp, io, *offset, 1, 1);
733 xfs_rw_enter_trace(XFS_DIOWR_ENTER,
734 io, buf, size, *offset, ioflags);
735 ret = do_generic_direct_write(file, buf, size, offset);
736 } else {
737 xfs_rw_enter_trace(XFS_WRITE_ENTER,
738 io, buf, size, *offset, ioflags);
739 ret = do_generic_file_write(file, buf, size, offset);
740 }
741
742 if (unlikely(ioflags & IO_INVIS)) {
743 /* generic_file_write updates the mtime/ctime but we need
744 * to undo that because this I/O was supposed to be
745 * invisible.
746 */
747 struct inode *inode = LINVFS_GET_IP(vp);
748 inode->i_mtime = xip->i_d.di_mtime.t_sec;
749 inode->i_ctime = xip->i_d.di_ctime.t_sec;
750 } else {
751 xfs_ichgtime(xip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
752 }
753
754 if ((ret == -ENOSPC) &&
755 DM_EVENT_ENABLED(vp->v_vfsp, xip, DM_EVENT_NOSPACE) &&
756 !(ioflags & IO_INVIS)) {
757
758 xfs_rwunlock(bdp, locktype);
759 error = XFS_SEND_NAMESP(xip->i_mount, DM_EVENT_NOSPACE, vp,
760 DM_RIGHT_NULL, vp, DM_RIGHT_NULL, NULL, NULL,
761 0, 0, 0); /* Delay flag intentionally unused */
762 if (error)
763 return -error;
764 xfs_rwlock(bdp, locktype);
765 *offset = xip->i_d.di_size;
766 goto retry;
767 }
768
769 error:
770 if (ret <= 0) {
771 if (iolock)
772 xfs_rwunlock(bdp, locktype);
773 return ret;
774 }
775
776 XFS_STATS_ADD(xs_write_bytes, ret);
777
778 if (*offset > xip->i_d.di_size) {
779 xfs_ilock(xip, XFS_ILOCK_EXCL);
780 if (*offset > xip->i_d.di_size) {
781 struct inode *inode = LINVFS_GET_IP(vp);
782
783 xip->i_d.di_size = *offset;
784 i_size_write(inode, *offset);
785 xip->i_update_core = 1;
786 xip->i_update_size = 1;
787 mark_inode_dirty_sync(inode);
788 }
789 xfs_iunlock(xip, XFS_ILOCK_EXCL);
790 }
791
792 /* Handle various SYNC-type writes */
793 if ((file->f_flags & O_SYNC) || IS_SYNC(file->f_dentry->d_inode)) {
794
795 /*
796 * If we're treating this as O_DSYNC and we have not updated the
797 * size, force the log.
798 */
799
800 if (!(mp->m_flags & XFS_MOUNT_OSYNCISOSYNC)
801 && !(xip->i_update_size)) {
802 /*
803 * If an allocation transaction occurred
804 * without extending the size, then we have to force
805 * the log up the proper point to ensure that the
806 * allocation is permanent. We can't count on
807 * the fact that buffered writes lock out direct I/O
808 * writes - the direct I/O write could have extended
809 * the size nontransactionally, then finished before
810 * we started. xfs_write_file will think that the file
811 * didn't grow but the update isn't safe unless the
812 * size change is logged.
813 *
814 * Force the log if we've committed a transaction
815 * against the inode or if someone else has and
816 * the commit record hasn't gone to disk (e.g.
817 * the inode is pinned). This guarantees that
818 * all changes affecting the inode are permanent
819 * when we return.
820 */
821
822 xfs_inode_log_item_t *iip;
823 xfs_lsn_t lsn;
824
825 iip = xip->i_itemp;
826 if (iip && iip->ili_last_lsn) {
827 lsn = iip->ili_last_lsn;
828 xfs_log_force(mp, lsn,
829 XFS_LOG_FORCE | XFS_LOG_SYNC);
830 } else if (xfs_ipincount(xip) > 0) {
831 xfs_log_force(mp, (xfs_lsn_t)0,
832 XFS_LOG_FORCE | XFS_LOG_SYNC);
833 }
834
835 } else {
836 xfs_trans_t *tp;
837
838 /*
839 * O_SYNC or O_DSYNC _with_ a size update are handled
840 * the same way.
841 *
842 * If the write was synchronous then we need to make
843 * sure that the inode modification time is permanent.
844 * We'll have updated the timestamp above, so here
845 * we use a synchronous transaction to log the inode.
846 * It's not fast, but it's necessary.
847 *
848 * If this a dsync write and the size got changed
849 * non-transactionally, then we need to ensure that
850 * the size change gets logged in a synchronous
851 * transaction.
852 */
853
854 tp = xfs_trans_alloc(mp, XFS_TRANS_WRITE_SYNC);
855 if ((error = xfs_trans_reserve(tp, 0,
856 XFS_SWRITE_LOG_RES(mp),
857 0, 0, 0))) {
858 /* Transaction reserve failed */
859 xfs_trans_cancel(tp, 0);
860 } else {
861 /* Transaction reserve successful */
862 xfs_ilock(xip, XFS_ILOCK_EXCL);
863 xfs_trans_ijoin(tp, xip, XFS_ILOCK_EXCL);
864 xfs_trans_ihold(tp, xip);
865 xfs_trans_log_inode(tp, xip, XFS_ILOG_CORE);
866 xfs_trans_set_sync(tp);
867 error = xfs_trans_commit(tp, 0, NULL);
868 xfs_iunlock(xip, XFS_ILOCK_EXCL);
869 }
870 }
871 } /* (ioflags & O_SYNC) */
872
873 /*
874 * If we are coming from an nfsd thread then insert into the
875 * reference cache.
876 */
877
878 if (!strcmp(current->comm, "nfsd"))
879 xfs_refcache_insert(xip);
880
881 /* Drop lock this way - the old refcache release is in here */
882 if (iolock)
883 xfs_rwunlock(bdp, locktype);
884
885 return(ret);
886 }
887
888 /*
889 * All xfs metadata buffers except log state machine buffers
890 * get this attached as their b_bdstrat callback function.
891 * This is so that we can catch a buffer
892 * after prematurely unpinning it to forcibly shutdown the filesystem.
893 */
894 int
xfs_bdstrat_cb(struct xfs_buf * bp)895 xfs_bdstrat_cb(struct xfs_buf *bp)
896 {
897 xfs_mount_t *mp;
898
899 mp = XFS_BUF_FSPRIVATE3(bp, xfs_mount_t *);
900 if (!XFS_FORCED_SHUTDOWN(mp)) {
901 pagebuf_iorequest(bp);
902 return 0;
903 } else {
904 xfs_buftrace("XFS__BDSTRAT IOERROR", bp);
905 /*
906 * Metadata write that didn't get logged but
907 * written delayed anyway. These aren't associated
908 * with a transaction, and can be ignored.
909 */
910 if (XFS_BUF_IODONE_FUNC(bp) == NULL &&
911 (XFS_BUF_ISREAD(bp)) == 0)
912 return (xfs_bioerror_relse(bp));
913 else
914 return (xfs_bioerror(bp));
915 }
916 }
917
918
919 int
xfs_bmap(bhv_desc_t * bdp,xfs_off_t offset,ssize_t count,int flags,xfs_iomap_t * iomapp,int * niomaps)920 xfs_bmap(bhv_desc_t *bdp,
921 xfs_off_t offset,
922 ssize_t count,
923 int flags,
924 xfs_iomap_t *iomapp,
925 int *niomaps)
926 {
927 xfs_inode_t *ip = XFS_BHVTOI(bdp);
928 xfs_iocore_t *io = &ip->i_iocore;
929
930 ASSERT((ip->i_d.di_mode & S_IFMT) == S_IFREG);
931 ASSERT(((ip->i_d.di_flags & XFS_DIFLAG_REALTIME) != 0) ==
932 ((ip->i_iocore.io_flags & XFS_IOCORE_RT) != 0));
933
934 return xfs_iomap(io, offset, count, flags, iomapp, niomaps);
935 }
936
937 /*
938 * Wrapper around bdstrat so that we can stop data
939 * from going to disk in case we are shutting down the filesystem.
940 * Typically user data goes thru this path; one of the exceptions
941 * is the superblock.
942 */
943 int
xfsbdstrat(struct xfs_mount * mp,struct xfs_buf * bp)944 xfsbdstrat(
945 struct xfs_mount *mp,
946 struct xfs_buf *bp)
947 {
948 ASSERT(mp);
949 if (!XFS_FORCED_SHUTDOWN(mp)) {
950 /* Grio redirection would go here
951 * if (XFS_BUF_IS_GRIO(bp)) {
952 */
953
954 pagebuf_iorequest(bp);
955 return 0;
956 }
957
958 xfs_buftrace("XFSBDSTRAT IOERROR", bp);
959 return (xfs_bioerror_relse(bp));
960 }
961
962 /*
963 * If the underlying (data/log/rt) device is readonly, there are some
964 * operations that cannot proceed.
965 */
966 int
xfs_dev_is_read_only(xfs_mount_t * mp,char * message)967 xfs_dev_is_read_only(
968 xfs_mount_t *mp,
969 char *message)
970 {
971 if (xfs_readonly_buftarg(mp->m_ddev_targp) ||
972 xfs_readonly_buftarg(mp->m_logdev_targp) ||
973 (mp->m_rtdev_targp && xfs_readonly_buftarg(mp->m_rtdev_targp))) {
974 cmn_err(CE_NOTE,
975 "XFS: %s required on read-only device.", message);
976 cmn_err(CE_NOTE,
977 "XFS: write access unavailable, cannot proceed.");
978 return EROFS;
979 }
980 return 0;
981 }
982