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1da177e4 LT |
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_acl.h" | |
68 | #include "xfs_cap.h" | |
69 | #include "xfs_mac.h" | |
70 | #include "xfs_attr.h" | |
71 | #include "xfs_inode_item.h" | |
72 | #include "xfs_buf_item.h" | |
73 | #include "xfs_utils.h" | |
74 | #include "xfs_iomap.h" | |
75 | ||
76 | #include <linux/capability.h> | |
77 | #include <linux/writeback.h> | |
78 | ||
79 | ||
80 | #if defined(XFS_RW_TRACE) | |
81 | void | |
82 | xfs_rw_enter_trace( | |
83 | int tag, | |
84 | xfs_iocore_t *io, | |
85 | void *data, | |
86 | size_t segs, | |
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 *)data, | |
100 | (void *)((unsigned long)segs), | |
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 | |
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 | |
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 | ||
1da177e4 LT |
212 | ssize_t /* bytes read, or (-) error */ |
213 | xfs_read( | |
214 | bhv_desc_t *bdp, | |
215 | struct kiocb *iocb, | |
216 | const struct iovec *iovp, | |
217 | unsigned int segs, | |
218 | loff_t *offset, | |
219 | int ioflags, | |
220 | cred_t *credp) | |
221 | { | |
222 | struct file *file = iocb->ki_filp; | |
223 | struct inode *inode = file->f_mapping->host; | |
224 | size_t size = 0; | |
225 | ssize_t ret; | |
226 | xfs_fsize_t n; | |
227 | xfs_inode_t *ip; | |
228 | xfs_mount_t *mp; | |
229 | vnode_t *vp; | |
230 | unsigned long seg; | |
231 | ||
232 | ip = XFS_BHVTOI(bdp); | |
233 | vp = BHV_TO_VNODE(bdp); | |
234 | mp = ip->i_mount; | |
235 | ||
236 | XFS_STATS_INC(xs_read_calls); | |
237 | ||
238 | /* START copy & waste from filemap.c */ | |
239 | for (seg = 0; seg < segs; seg++) { | |
240 | const struct iovec *iv = &iovp[seg]; | |
241 | ||
242 | /* | |
243 | * If any segment has a negative length, or the cumulative | |
244 | * length ever wraps negative then return -EINVAL. | |
245 | */ | |
246 | size += iv->iov_len; | |
247 | if (unlikely((ssize_t)(size|iv->iov_len) < 0)) | |
248 | return XFS_ERROR(-EINVAL); | |
249 | } | |
250 | /* END copy & waste from filemap.c */ | |
251 | ||
252 | if (unlikely(ioflags & IO_ISDIRECT)) { | |
253 | xfs_buftarg_t *target = | |
254 | (ip->i_d.di_flags & XFS_DIFLAG_REALTIME) ? | |
255 | mp->m_rtdev_targp : mp->m_ddev_targp; | |
256 | if ((*offset & target->pbr_smask) || | |
257 | (size & target->pbr_smask)) { | |
258 | if (*offset == ip->i_d.di_size) { | |
259 | return (0); | |
260 | } | |
261 | return -XFS_ERROR(EINVAL); | |
262 | } | |
263 | } | |
264 | ||
265 | n = XFS_MAXIOFFSET(mp) - *offset; | |
266 | if ((n <= 0) || (size == 0)) | |
267 | return 0; | |
268 | ||
269 | if (n < size) | |
270 | size = n; | |
271 | ||
272 | if (XFS_FORCED_SHUTDOWN(mp)) { | |
273 | return -EIO; | |
274 | } | |
275 | ||
276 | if (unlikely(ioflags & IO_ISDIRECT)) | |
277 | down(&inode->i_sem); | |
278 | xfs_ilock(ip, XFS_IOLOCK_SHARED); | |
279 | ||
280 | if (DM_EVENT_ENABLED(vp->v_vfsp, ip, DM_EVENT_READ) && | |
281 | !(ioflags & IO_INVIS)) { | |
282 | vrwlock_t locktype = VRWLOCK_READ; | |
283 | ||
284 | ret = -XFS_SEND_DATA(mp, DM_EVENT_READ, | |
285 | BHV_TO_VNODE(bdp), *offset, size, | |
286 | FILP_DELAY_FLAG(file), &locktype); | |
287 | if (ret) { | |
288 | xfs_iunlock(ip, XFS_IOLOCK_SHARED); | |
289 | goto unlock_isem; | |
290 | } | |
291 | } | |
292 | ||
293 | xfs_rw_enter_trace(XFS_READ_ENTER, &ip->i_iocore, | |
294 | (void *)iovp, segs, *offset, ioflags); | |
295 | ret = __generic_file_aio_read(iocb, iovp, segs, offset); | |
296 | if (ret == -EIOCBQUEUED && !(ioflags & IO_ISAIO)) | |
297 | ret = wait_on_sync_kiocb(iocb); | |
298 | if (ret > 0) | |
299 | XFS_STATS_ADD(xs_read_bytes, ret); | |
300 | ||
301 | xfs_iunlock(ip, XFS_IOLOCK_SHARED); | |
302 | ||
303 | if (likely(!(ioflags & IO_INVIS))) | |
304 | xfs_ichgtime(ip, XFS_ICHGTIME_ACC); | |
305 | ||
306 | unlock_isem: | |
307 | if (unlikely(ioflags & IO_ISDIRECT)) | |
308 | up(&inode->i_sem); | |
309 | return ret; | |
310 | } | |
311 | ||
312 | ssize_t | |
313 | xfs_sendfile( | |
314 | bhv_desc_t *bdp, | |
315 | struct file *filp, | |
316 | loff_t *offset, | |
317 | int ioflags, | |
318 | size_t count, | |
319 | read_actor_t actor, | |
320 | void *target, | |
321 | cred_t *credp) | |
322 | { | |
323 | ssize_t ret; | |
324 | xfs_fsize_t n; | |
325 | xfs_inode_t *ip; | |
326 | xfs_mount_t *mp; | |
327 | vnode_t *vp; | |
328 | ||
329 | ip = XFS_BHVTOI(bdp); | |
330 | vp = BHV_TO_VNODE(bdp); | |
331 | mp = ip->i_mount; | |
332 | ||
333 | XFS_STATS_INC(xs_read_calls); | |
334 | ||
335 | n = XFS_MAXIOFFSET(mp) - *offset; | |
336 | if ((n <= 0) || (count == 0)) | |
337 | return 0; | |
338 | ||
339 | if (n < count) | |
340 | count = n; | |
341 | ||
342 | if (XFS_FORCED_SHUTDOWN(ip->i_mount)) | |
343 | return -EIO; | |
344 | ||
345 | xfs_ilock(ip, XFS_IOLOCK_SHARED); | |
346 | ||
347 | if (DM_EVENT_ENABLED(vp->v_vfsp, ip, DM_EVENT_READ) && | |
348 | (!(ioflags & IO_INVIS))) { | |
349 | vrwlock_t locktype = VRWLOCK_READ; | |
350 | int error; | |
351 | ||
352 | error = XFS_SEND_DATA(mp, DM_EVENT_READ, BHV_TO_VNODE(bdp), *offset, count, | |
353 | FILP_DELAY_FLAG(filp), &locktype); | |
354 | if (error) { | |
355 | xfs_iunlock(ip, XFS_IOLOCK_SHARED); | |
356 | return -error; | |
357 | } | |
358 | } | |
359 | xfs_rw_enter_trace(XFS_SENDFILE_ENTER, &ip->i_iocore, | |
360 | (void *)(unsigned long)target, count, *offset, ioflags); | |
361 | ret = generic_file_sendfile(filp, offset, count, actor, target); | |
362 | ||
363 | xfs_iunlock(ip, XFS_IOLOCK_SHARED); | |
364 | ||
365 | if (ret > 0) | |
366 | XFS_STATS_ADD(xs_read_bytes, ret); | |
367 | ||
368 | if (likely(!(ioflags & IO_INVIS))) | |
369 | xfs_ichgtime(ip, XFS_ICHGTIME_ACC); | |
370 | ||
371 | return ret; | |
372 | } | |
373 | ||
374 | /* | |
375 | * This routine is called to handle zeroing any space in the last | |
376 | * block of the file that is beyond the EOF. We do this since the | |
377 | * size is being increased without writing anything to that block | |
378 | * and we don't want anyone to read the garbage on the disk. | |
379 | */ | |
380 | STATIC int /* error (positive) */ | |
381 | xfs_zero_last_block( | |
382 | struct inode *ip, | |
383 | xfs_iocore_t *io, | |
384 | xfs_off_t offset, | |
385 | xfs_fsize_t isize, | |
386 | xfs_fsize_t end_size) | |
387 | { | |
388 | xfs_fileoff_t last_fsb; | |
389 | xfs_mount_t *mp; | |
390 | int nimaps; | |
391 | int zero_offset; | |
392 | int zero_len; | |
393 | int isize_fsb_offset; | |
394 | int error = 0; | |
395 | xfs_bmbt_irec_t imap; | |
396 | loff_t loff; | |
397 | size_t lsize; | |
398 | ||
399 | ASSERT(ismrlocked(io->io_lock, MR_UPDATE) != 0); | |
400 | ASSERT(offset > isize); | |
401 | ||
402 | mp = io->io_mount; | |
403 | ||
404 | isize_fsb_offset = XFS_B_FSB_OFFSET(mp, isize); | |
405 | if (isize_fsb_offset == 0) { | |
406 | /* | |
407 | * There are no extra bytes in the last block on disk to | |
408 | * zero, so return. | |
409 | */ | |
410 | return 0; | |
411 | } | |
412 | ||
413 | last_fsb = XFS_B_TO_FSBT(mp, isize); | |
414 | nimaps = 1; | |
415 | error = XFS_BMAPI(mp, NULL, io, last_fsb, 1, 0, NULL, 0, &imap, | |
416 | &nimaps, NULL); | |
417 | if (error) { | |
418 | return error; | |
419 | } | |
420 | ASSERT(nimaps > 0); | |
421 | /* | |
422 | * If the block underlying isize is just a hole, then there | |
423 | * is nothing to zero. | |
424 | */ | |
425 | if (imap.br_startblock == HOLESTARTBLOCK) { | |
426 | return 0; | |
427 | } | |
428 | /* | |
429 | * Zero the part of the last block beyond the EOF, and write it | |
430 | * out sync. We need to drop the ilock while we do this so we | |
431 | * don't deadlock when the buffer cache calls back to us. | |
432 | */ | |
433 | XFS_IUNLOCK(mp, io, XFS_ILOCK_EXCL| XFS_EXTSIZE_RD); | |
434 | loff = XFS_FSB_TO_B(mp, last_fsb); | |
435 | lsize = XFS_FSB_TO_B(mp, 1); | |
436 | ||
437 | zero_offset = isize_fsb_offset; | |
438 | zero_len = mp->m_sb.sb_blocksize - isize_fsb_offset; | |
439 | ||
440 | error = xfs_iozero(ip, loff + zero_offset, zero_len, end_size); | |
441 | ||
442 | XFS_ILOCK(mp, io, XFS_ILOCK_EXCL|XFS_EXTSIZE_RD); | |
443 | ASSERT(error >= 0); | |
444 | return error; | |
445 | } | |
446 | ||
447 | /* | |
448 | * Zero any on disk space between the current EOF and the new, | |
449 | * larger EOF. This handles the normal case of zeroing the remainder | |
450 | * of the last block in the file and the unusual case of zeroing blocks | |
451 | * out beyond the size of the file. This second case only happens | |
452 | * with fixed size extents and when the system crashes before the inode | |
453 | * size was updated but after blocks were allocated. If fill is set, | |
454 | * then any holes in the range are filled and zeroed. If not, the holes | |
455 | * are left alone as holes. | |
456 | */ | |
457 | ||
458 | int /* error (positive) */ | |
459 | xfs_zero_eof( | |
460 | vnode_t *vp, | |
461 | xfs_iocore_t *io, | |
462 | xfs_off_t offset, /* starting I/O offset */ | |
463 | xfs_fsize_t isize, /* current inode size */ | |
464 | xfs_fsize_t end_size) /* terminal inode size */ | |
465 | { | |
466 | struct inode *ip = LINVFS_GET_IP(vp); | |
467 | xfs_fileoff_t start_zero_fsb; | |
468 | xfs_fileoff_t end_zero_fsb; | |
469 | xfs_fileoff_t prev_zero_fsb; | |
470 | xfs_fileoff_t zero_count_fsb; | |
471 | xfs_fileoff_t last_fsb; | |
472 | xfs_extlen_t buf_len_fsb; | |
473 | xfs_extlen_t prev_zero_count; | |
474 | xfs_mount_t *mp; | |
475 | int nimaps; | |
476 | int error = 0; | |
477 | xfs_bmbt_irec_t imap; | |
478 | loff_t loff; | |
479 | size_t lsize; | |
480 | ||
481 | ASSERT(ismrlocked(io->io_lock, MR_UPDATE)); | |
482 | ASSERT(ismrlocked(io->io_iolock, MR_UPDATE)); | |
483 | ||
484 | mp = io->io_mount; | |
485 | ||
486 | /* | |
487 | * First handle zeroing the block on which isize resides. | |
488 | * We only zero a part of that block so it is handled specially. | |
489 | */ | |
490 | error = xfs_zero_last_block(ip, io, offset, isize, end_size); | |
491 | if (error) { | |
492 | ASSERT(ismrlocked(io->io_lock, MR_UPDATE)); | |
493 | ASSERT(ismrlocked(io->io_iolock, MR_UPDATE)); | |
494 | return error; | |
495 | } | |
496 | ||
497 | /* | |
498 | * Calculate the range between the new size and the old | |
499 | * where blocks needing to be zeroed may exist. To get the | |
500 | * block where the last byte in the file currently resides, | |
501 | * we need to subtract one from the size and truncate back | |
502 | * to a block boundary. We subtract 1 in case the size is | |
503 | * exactly on a block boundary. | |
504 | */ | |
505 | last_fsb = isize ? XFS_B_TO_FSBT(mp, isize - 1) : (xfs_fileoff_t)-1; | |
506 | start_zero_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)isize); | |
507 | end_zero_fsb = XFS_B_TO_FSBT(mp, offset - 1); | |
508 | ASSERT((xfs_sfiloff_t)last_fsb < (xfs_sfiloff_t)start_zero_fsb); | |
509 | if (last_fsb == end_zero_fsb) { | |
510 | /* | |
511 | * The size was only incremented on its last block. | |
512 | * We took care of that above, so just return. | |
513 | */ | |
514 | return 0; | |
515 | } | |
516 | ||
517 | ASSERT(start_zero_fsb <= end_zero_fsb); | |
518 | prev_zero_fsb = NULLFILEOFF; | |
519 | prev_zero_count = 0; | |
520 | while (start_zero_fsb <= end_zero_fsb) { | |
521 | nimaps = 1; | |
522 | zero_count_fsb = end_zero_fsb - start_zero_fsb + 1; | |
523 | error = XFS_BMAPI(mp, NULL, io, start_zero_fsb, zero_count_fsb, | |
524 | 0, NULL, 0, &imap, &nimaps, NULL); | |
525 | if (error) { | |
526 | ASSERT(ismrlocked(io->io_lock, MR_UPDATE)); | |
527 | ASSERT(ismrlocked(io->io_iolock, MR_UPDATE)); | |
528 | return error; | |
529 | } | |
530 | ASSERT(nimaps > 0); | |
531 | ||
532 | if (imap.br_state == XFS_EXT_UNWRITTEN || | |
533 | imap.br_startblock == HOLESTARTBLOCK) { | |
534 | /* | |
535 | * This loop handles initializing pages that were | |
536 | * partially initialized by the code below this | |
537 | * loop. It basically zeroes the part of the page | |
538 | * that sits on a hole and sets the page as P_HOLE | |
539 | * and calls remapf if it is a mapped file. | |
540 | */ | |
541 | prev_zero_fsb = NULLFILEOFF; | |
542 | prev_zero_count = 0; | |
543 | start_zero_fsb = imap.br_startoff + | |
544 | imap.br_blockcount; | |
545 | ASSERT(start_zero_fsb <= (end_zero_fsb + 1)); | |
546 | continue; | |
547 | } | |
548 | ||
549 | /* | |
550 | * There are blocks in the range requested. | |
551 | * Zero them a single write at a time. We actually | |
552 | * don't zero the entire range returned if it is | |
553 | * too big and simply loop around to get the rest. | |
554 | * That is not the most efficient thing to do, but it | |
555 | * is simple and this path should not be exercised often. | |
556 | */ | |
557 | buf_len_fsb = XFS_FILBLKS_MIN(imap.br_blockcount, | |
558 | mp->m_writeio_blocks << 8); | |
559 | /* | |
560 | * Drop the inode lock while we're doing the I/O. | |
561 | * We'll still have the iolock to protect us. | |
562 | */ | |
563 | XFS_IUNLOCK(mp, io, XFS_ILOCK_EXCL|XFS_EXTSIZE_RD); | |
564 | ||
565 | loff = XFS_FSB_TO_B(mp, start_zero_fsb); | |
566 | lsize = XFS_FSB_TO_B(mp, buf_len_fsb); | |
567 | ||
568 | error = xfs_iozero(ip, loff, lsize, end_size); | |
569 | ||
570 | if (error) { | |
571 | goto out_lock; | |
572 | } | |
573 | ||
574 | prev_zero_fsb = start_zero_fsb; | |
575 | prev_zero_count = buf_len_fsb; | |
576 | start_zero_fsb = imap.br_startoff + buf_len_fsb; | |
577 | ASSERT(start_zero_fsb <= (end_zero_fsb + 1)); | |
578 | ||
579 | XFS_ILOCK(mp, io, XFS_ILOCK_EXCL|XFS_EXTSIZE_RD); | |
580 | } | |
581 | ||
582 | return 0; | |
583 | ||
584 | out_lock: | |
585 | ||
586 | XFS_ILOCK(mp, io, XFS_ILOCK_EXCL|XFS_EXTSIZE_RD); | |
587 | ASSERT(error >= 0); | |
588 | return error; | |
589 | } | |
590 | ||
591 | ssize_t /* bytes written, or (-) error */ | |
592 | xfs_write( | |
593 | bhv_desc_t *bdp, | |
594 | struct kiocb *iocb, | |
595 | const struct iovec *iovp, | |
596 | unsigned int nsegs, | |
597 | loff_t *offset, | |
598 | int ioflags, | |
599 | cred_t *credp) | |
600 | { | |
601 | struct file *file = iocb->ki_filp; | |
602 | struct address_space *mapping = file->f_mapping; | |
603 | struct inode *inode = mapping->host; | |
604 | unsigned long segs = nsegs; | |
605 | xfs_inode_t *xip; | |
606 | xfs_mount_t *mp; | |
607 | ssize_t ret = 0, error = 0; | |
608 | xfs_fsize_t isize, new_size; | |
609 | xfs_iocore_t *io; | |
610 | vnode_t *vp; | |
611 | unsigned long seg; | |
612 | int iolock; | |
613 | int eventsent = 0; | |
614 | vrwlock_t locktype; | |
615 | size_t ocount = 0, count; | |
616 | loff_t pos; | |
617 | int need_isem = 1, need_flush = 0; | |
618 | ||
619 | XFS_STATS_INC(xs_write_calls); | |
620 | ||
621 | vp = BHV_TO_VNODE(bdp); | |
622 | xip = XFS_BHVTOI(bdp); | |
623 | ||
624 | for (seg = 0; seg < segs; seg++) { | |
625 | const struct iovec *iv = &iovp[seg]; | |
626 | ||
627 | /* | |
628 | * If any segment has a negative length, or the cumulative | |
629 | * length ever wraps negative then return -EINVAL. | |
630 | */ | |
631 | ocount += iv->iov_len; | |
632 | if (unlikely((ssize_t)(ocount|iv->iov_len) < 0)) | |
633 | return -EINVAL; | |
634 | if (access_ok(VERIFY_READ, iv->iov_base, iv->iov_len)) | |
635 | continue; | |
636 | if (seg == 0) | |
637 | return -EFAULT; | |
638 | segs = seg; | |
639 | ocount -= iv->iov_len; /* This segment is no good */ | |
640 | break; | |
641 | } | |
642 | ||
643 | count = ocount; | |
644 | pos = *offset; | |
645 | ||
646 | if (count == 0) | |
647 | return 0; | |
648 | ||
649 | io = &xip->i_iocore; | |
650 | mp = io->io_mount; | |
651 | ||
652 | if (XFS_FORCED_SHUTDOWN(mp)) | |
653 | return -EIO; | |
654 | ||
655 | fs_check_frozen(vp->v_vfsp, SB_FREEZE_WRITE); | |
656 | ||
657 | if (ioflags & IO_ISDIRECT) { | |
658 | xfs_buftarg_t *target = | |
659 | (xip->i_d.di_flags & XFS_DIFLAG_REALTIME) ? | |
660 | mp->m_rtdev_targp : mp->m_ddev_targp; | |
661 | ||
3f243766 NS |
662 | if (ioflags & IO_ISAIO) |
663 | return XFS_ERROR(-ENOSYS); | |
664 | ||
1da177e4 LT |
665 | if ((pos & target->pbr_smask) || (count & target->pbr_smask)) |
666 | return XFS_ERROR(-EINVAL); | |
667 | ||
668 | if (!VN_CACHED(vp) && pos < i_size_read(inode)) | |
669 | need_isem = 0; | |
670 | ||
671 | if (VN_CACHED(vp)) | |
672 | need_flush = 1; | |
673 | } | |
674 | ||
675 | relock: | |
676 | if (need_isem) { | |
677 | iolock = XFS_IOLOCK_EXCL; | |
678 | locktype = VRWLOCK_WRITE; | |
679 | ||
680 | down(&inode->i_sem); | |
681 | } else { | |
682 | iolock = XFS_IOLOCK_SHARED; | |
683 | locktype = VRWLOCK_WRITE_DIRECT; | |
684 | } | |
685 | ||
686 | xfs_ilock(xip, XFS_ILOCK_EXCL|iolock); | |
687 | ||
688 | isize = i_size_read(inode); | |
689 | ||
690 | if (file->f_flags & O_APPEND) | |
691 | *offset = isize; | |
692 | ||
693 | start: | |
694 | error = -generic_write_checks(file, &pos, &count, | |
695 | S_ISBLK(inode->i_mode)); | |
696 | if (error) { | |
697 | xfs_iunlock(xip, XFS_ILOCK_EXCL|iolock); | |
698 | goto out_unlock_isem; | |
699 | } | |
700 | ||
701 | new_size = pos + count; | |
702 | if (new_size > isize) | |
703 | io->io_new_size = new_size; | |
704 | ||
705 | if ((DM_EVENT_ENABLED(vp->v_vfsp, xip, DM_EVENT_WRITE) && | |
706 | !(ioflags & IO_INVIS) && !eventsent)) { | |
707 | loff_t savedsize = pos; | |
708 | int dmflags = FILP_DELAY_FLAG(file); | |
709 | ||
710 | if (need_isem) | |
711 | dmflags |= DM_FLAGS_ISEM; | |
712 | ||
713 | xfs_iunlock(xip, XFS_ILOCK_EXCL); | |
714 | error = XFS_SEND_DATA(xip->i_mount, DM_EVENT_WRITE, vp, | |
715 | pos, count, | |
716 | dmflags, &locktype); | |
717 | if (error) { | |
718 | xfs_iunlock(xip, iolock); | |
719 | goto out_unlock_isem; | |
720 | } | |
721 | xfs_ilock(xip, XFS_ILOCK_EXCL); | |
722 | eventsent = 1; | |
723 | ||
724 | /* | |
725 | * The iolock was dropped and reaquired in XFS_SEND_DATA | |
726 | * so we have to recheck the size when appending. | |
727 | * We will only "goto start;" once, since having sent the | |
728 | * event prevents another call to XFS_SEND_DATA, which is | |
729 | * what allows the size to change in the first place. | |
730 | */ | |
731 | if ((file->f_flags & O_APPEND) && savedsize != isize) { | |
732 | pos = isize = xip->i_d.di_size; | |
733 | goto start; | |
734 | } | |
735 | } | |
736 | ||
737 | /* | |
738 | * On Linux, generic_file_write updates the times even if | |
739 | * no data is copied in so long as the write had a size. | |
740 | * | |
741 | * We must update xfs' times since revalidate will overcopy xfs. | |
742 | */ | |
743 | if (!(ioflags & IO_INVIS)) { | |
744 | xfs_ichgtime(xip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG); | |
745 | inode_update_time(inode, 1); | |
746 | } | |
747 | ||
748 | /* | |
749 | * If the offset is beyond the size of the file, we have a couple | |
750 | * of things to do. First, if there is already space allocated | |
751 | * we need to either create holes or zero the disk or ... | |
752 | * | |
753 | * If there is a page where the previous size lands, we need | |
754 | * to zero it out up to the new size. | |
755 | */ | |
756 | ||
757 | if (pos > isize) { | |
758 | error = xfs_zero_eof(BHV_TO_VNODE(bdp), io, pos, | |
759 | isize, pos + count); | |
760 | if (error) { | |
761 | xfs_iunlock(xip, XFS_ILOCK_EXCL|iolock); | |
762 | goto out_unlock_isem; | |
763 | } | |
764 | } | |
765 | xfs_iunlock(xip, XFS_ILOCK_EXCL); | |
766 | ||
767 | /* | |
768 | * If we're writing the file then make sure to clear the | |
769 | * setuid and setgid bits if the process is not being run | |
770 | * by root. This keeps people from modifying setuid and | |
771 | * setgid binaries. | |
772 | */ | |
773 | ||
774 | if (((xip->i_d.di_mode & S_ISUID) || | |
775 | ((xip->i_d.di_mode & (S_ISGID | S_IXGRP)) == | |
776 | (S_ISGID | S_IXGRP))) && | |
777 | !capable(CAP_FSETID)) { | |
778 | error = xfs_write_clear_setuid(xip); | |
779 | if (likely(!error)) | |
780 | error = -remove_suid(file->f_dentry); | |
781 | if (unlikely(error)) { | |
782 | xfs_iunlock(xip, iolock); | |
783 | goto out_unlock_isem; | |
784 | } | |
785 | } | |
786 | ||
787 | retry: | |
788 | /* We can write back this queue in page reclaim */ | |
789 | current->backing_dev_info = mapping->backing_dev_info; | |
790 | ||
791 | if ((ioflags & IO_ISDIRECT)) { | |
792 | if (need_flush) { | |
793 | xfs_inval_cached_trace(io, pos, -1, | |
794 | ctooff(offtoct(pos)), -1); | |
795 | VOP_FLUSHINVAL_PAGES(vp, ctooff(offtoct(pos)), | |
796 | -1, FI_REMAPF_LOCKED); | |
797 | } | |
798 | ||
799 | if (need_isem) { | |
800 | /* demote the lock now the cached pages are gone */ | |
801 | XFS_ILOCK_DEMOTE(mp, io, XFS_IOLOCK_EXCL); | |
802 | up(&inode->i_sem); | |
803 | ||
804 | iolock = XFS_IOLOCK_SHARED; | |
805 | locktype = VRWLOCK_WRITE_DIRECT; | |
806 | need_isem = 0; | |
807 | } | |
808 | ||
809 | xfs_rw_enter_trace(XFS_DIOWR_ENTER, io, (void *)iovp, segs, | |
810 | *offset, ioflags); | |
811 | ret = generic_file_direct_write(iocb, iovp, | |
812 | &segs, pos, offset, count, ocount); | |
813 | ||
814 | /* | |
815 | * direct-io write to a hole: fall through to buffered I/O | |
816 | * for completing the rest of the request. | |
817 | */ | |
818 | if (ret >= 0 && ret != count) { | |
819 | XFS_STATS_ADD(xs_write_bytes, ret); | |
820 | ||
821 | pos += ret; | |
822 | count -= ret; | |
823 | ||
824 | need_isem = 1; | |
825 | ioflags &= ~IO_ISDIRECT; | |
826 | xfs_iunlock(xip, iolock); | |
827 | goto relock; | |
828 | } | |
829 | } else { | |
830 | xfs_rw_enter_trace(XFS_WRITE_ENTER, io, (void *)iovp, segs, | |
831 | *offset, ioflags); | |
832 | ret = generic_file_buffered_write(iocb, iovp, segs, | |
833 | pos, offset, count, ret); | |
834 | } | |
835 | ||
836 | current->backing_dev_info = NULL; | |
837 | ||
838 | if (ret == -EIOCBQUEUED && !(ioflags & IO_ISAIO)) | |
839 | ret = wait_on_sync_kiocb(iocb); | |
840 | ||
841 | if ((ret == -ENOSPC) && | |
842 | DM_EVENT_ENABLED(vp->v_vfsp, xip, DM_EVENT_NOSPACE) && | |
843 | !(ioflags & IO_INVIS)) { | |
844 | ||
845 | xfs_rwunlock(bdp, locktype); | |
846 | error = XFS_SEND_NAMESP(xip->i_mount, DM_EVENT_NOSPACE, vp, | |
847 | DM_RIGHT_NULL, vp, DM_RIGHT_NULL, NULL, NULL, | |
848 | 0, 0, 0); /* Delay flag intentionally unused */ | |
849 | if (error) | |
850 | goto out_unlock_isem; | |
851 | xfs_rwlock(bdp, locktype); | |
852 | pos = xip->i_d.di_size; | |
853 | ret = 0; | |
854 | goto retry; | |
855 | } | |
856 | ||
857 | if (*offset > xip->i_d.di_size) { | |
858 | xfs_ilock(xip, XFS_ILOCK_EXCL); | |
859 | if (*offset > xip->i_d.di_size) { | |
860 | xip->i_d.di_size = *offset; | |
861 | i_size_write(inode, *offset); | |
862 | xip->i_update_core = 1; | |
863 | xip->i_update_size = 1; | |
864 | } | |
865 | xfs_iunlock(xip, XFS_ILOCK_EXCL); | |
866 | } | |
867 | ||
868 | error = -ret; | |
869 | if (ret <= 0) | |
870 | goto out_unlock_internal; | |
871 | ||
872 | XFS_STATS_ADD(xs_write_bytes, ret); | |
873 | ||
874 | /* Handle various SYNC-type writes */ | |
875 | if ((file->f_flags & O_SYNC) || IS_SYNC(inode)) { | |
876 | /* | |
877 | * If we're treating this as O_DSYNC and we have not updated the | |
878 | * size, force the log. | |
879 | */ | |
880 | if (!(mp->m_flags & XFS_MOUNT_OSYNCISOSYNC) && | |
881 | !(xip->i_update_size)) { | |
882 | xfs_inode_log_item_t *iip = xip->i_itemp; | |
883 | ||
884 | /* | |
885 | * If an allocation transaction occurred | |
886 | * without extending the size, then we have to force | |
887 | * the log up the proper point to ensure that the | |
888 | * allocation is permanent. We can't count on | |
889 | * the fact that buffered writes lock out direct I/O | |
890 | * writes - the direct I/O write could have extended | |
891 | * the size nontransactionally, then finished before | |
892 | * we started. xfs_write_file will think that the file | |
893 | * didn't grow but the update isn't safe unless the | |
894 | * size change is logged. | |
895 | * | |
896 | * Force the log if we've committed a transaction | |
897 | * against the inode or if someone else has and | |
898 | * the commit record hasn't gone to disk (e.g. | |
899 | * the inode is pinned). This guarantees that | |
900 | * all changes affecting the inode are permanent | |
901 | * when we return. | |
902 | */ | |
903 | if (iip && iip->ili_last_lsn) { | |
904 | xfs_log_force(mp, iip->ili_last_lsn, | |
905 | XFS_LOG_FORCE | XFS_LOG_SYNC); | |
906 | } else if (xfs_ipincount(xip) > 0) { | |
907 | xfs_log_force(mp, (xfs_lsn_t)0, | |
908 | XFS_LOG_FORCE | XFS_LOG_SYNC); | |
909 | } | |
910 | ||
911 | } else { | |
912 | xfs_trans_t *tp; | |
913 | ||
914 | /* | |
915 | * O_SYNC or O_DSYNC _with_ a size update are handled | |
916 | * the same way. | |
917 | * | |
918 | * If the write was synchronous then we need to make | |
919 | * sure that the inode modification time is permanent. | |
920 | * We'll have updated the timestamp above, so here | |
921 | * we use a synchronous transaction to log the inode. | |
922 | * It's not fast, but it's necessary. | |
923 | * | |
924 | * If this a dsync write and the size got changed | |
925 | * non-transactionally, then we need to ensure that | |
926 | * the size change gets logged in a synchronous | |
927 | * transaction. | |
928 | */ | |
929 | ||
930 | tp = xfs_trans_alloc(mp, XFS_TRANS_WRITE_SYNC); | |
931 | if ((error = xfs_trans_reserve(tp, 0, | |
932 | XFS_SWRITE_LOG_RES(mp), | |
933 | 0, 0, 0))) { | |
934 | /* Transaction reserve failed */ | |
935 | xfs_trans_cancel(tp, 0); | |
936 | } else { | |
937 | /* Transaction reserve successful */ | |
938 | xfs_ilock(xip, XFS_ILOCK_EXCL); | |
939 | xfs_trans_ijoin(tp, xip, XFS_ILOCK_EXCL); | |
940 | xfs_trans_ihold(tp, xip); | |
941 | xfs_trans_log_inode(tp, xip, XFS_ILOG_CORE); | |
942 | xfs_trans_set_sync(tp); | |
943 | error = xfs_trans_commit(tp, 0, NULL); | |
944 | xfs_iunlock(xip, XFS_ILOCK_EXCL); | |
945 | } | |
946 | if (error) | |
947 | goto out_unlock_internal; | |
948 | } | |
949 | ||
950 | xfs_rwunlock(bdp, locktype); | |
951 | if (need_isem) | |
952 | up(&inode->i_sem); | |
953 | ||
954 | error = sync_page_range(inode, mapping, pos, ret); | |
955 | if (!error) | |
956 | error = ret; | |
957 | return error; | |
958 | } | |
959 | ||
960 | out_unlock_internal: | |
961 | xfs_rwunlock(bdp, locktype); | |
962 | out_unlock_isem: | |
963 | if (need_isem) | |
964 | up(&inode->i_sem); | |
965 | return -error; | |
966 | } | |
967 | ||
968 | /* | |
969 | * All xfs metadata buffers except log state machine buffers | |
970 | * get this attached as their b_bdstrat callback function. | |
971 | * This is so that we can catch a buffer | |
972 | * after prematurely unpinning it to forcibly shutdown the filesystem. | |
973 | */ | |
974 | int | |
975 | xfs_bdstrat_cb(struct xfs_buf *bp) | |
976 | { | |
977 | xfs_mount_t *mp; | |
978 | ||
979 | mp = XFS_BUF_FSPRIVATE3(bp, xfs_mount_t *); | |
980 | if (!XFS_FORCED_SHUTDOWN(mp)) { | |
981 | pagebuf_iorequest(bp); | |
982 | return 0; | |
983 | } else { | |
984 | xfs_buftrace("XFS__BDSTRAT IOERROR", bp); | |
985 | /* | |
986 | * Metadata write that didn't get logged but | |
987 | * written delayed anyway. These aren't associated | |
988 | * with a transaction, and can be ignored. | |
989 | */ | |
990 | if (XFS_BUF_IODONE_FUNC(bp) == NULL && | |
991 | (XFS_BUF_ISREAD(bp)) == 0) | |
992 | return (xfs_bioerror_relse(bp)); | |
993 | else | |
994 | return (xfs_bioerror(bp)); | |
995 | } | |
996 | } | |
997 | ||
998 | ||
999 | int | |
1000 | xfs_bmap(bhv_desc_t *bdp, | |
1001 | xfs_off_t offset, | |
1002 | ssize_t count, | |
1003 | int flags, | |
1004 | xfs_iomap_t *iomapp, | |
1005 | int *niomaps) | |
1006 | { | |
1007 | xfs_inode_t *ip = XFS_BHVTOI(bdp); | |
1008 | xfs_iocore_t *io = &ip->i_iocore; | |
1009 | ||
1010 | ASSERT((ip->i_d.di_mode & S_IFMT) == S_IFREG); | |
1011 | ASSERT(((ip->i_d.di_flags & XFS_DIFLAG_REALTIME) != 0) == | |
1012 | ((ip->i_iocore.io_flags & XFS_IOCORE_RT) != 0)); | |
1013 | ||
1014 | return xfs_iomap(io, offset, count, flags, iomapp, niomaps); | |
1015 | } | |
1016 | ||
1017 | /* | |
1018 | * Wrapper around bdstrat so that we can stop data | |
1019 | * from going to disk in case we are shutting down the filesystem. | |
1020 | * Typically user data goes thru this path; one of the exceptions | |
1021 | * is the superblock. | |
1022 | */ | |
1023 | int | |
1024 | xfsbdstrat( | |
1025 | struct xfs_mount *mp, | |
1026 | struct xfs_buf *bp) | |
1027 | { | |
1028 | ASSERT(mp); | |
1029 | if (!XFS_FORCED_SHUTDOWN(mp)) { | |
1030 | /* Grio redirection would go here | |
1031 | * if (XFS_BUF_IS_GRIO(bp)) { | |
1032 | */ | |
1033 | ||
1034 | pagebuf_iorequest(bp); | |
1035 | return 0; | |
1036 | } | |
1037 | ||
1038 | xfs_buftrace("XFSBDSTRAT IOERROR", bp); | |
1039 | return (xfs_bioerror_relse(bp)); | |
1040 | } | |
1041 | ||
1042 | /* | |
1043 | * If the underlying (data/log/rt) device is readonly, there are some | |
1044 | * operations that cannot proceed. | |
1045 | */ | |
1046 | int | |
1047 | xfs_dev_is_read_only( | |
1048 | xfs_mount_t *mp, | |
1049 | char *message) | |
1050 | { | |
1051 | if (xfs_readonly_buftarg(mp->m_ddev_targp) || | |
1052 | xfs_readonly_buftarg(mp->m_logdev_targp) || | |
1053 | (mp->m_rtdev_targp && xfs_readonly_buftarg(mp->m_rtdev_targp))) { | |
1054 | cmn_err(CE_NOTE, | |
1055 | "XFS: %s required on read-only device.", message); | |
1056 | cmn_err(CE_NOTE, | |
1057 | "XFS: write access unavailable, cannot proceed."); | |
1058 | return EROFS; | |
1059 | } | |
1060 | return 0; | |
1061 | } |