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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/xfs/linux-2.6/xfs_aops.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'fs/xfs/linux-2.6/xfs_aops.c')
-rw-r--r--fs/xfs/linux-2.6/xfs_aops.c1275
1 files changed, 1275 insertions, 0 deletions
diff --git a/fs/xfs/linux-2.6/xfs_aops.c b/fs/xfs/linux-2.6/xfs_aops.c
new file mode 100644
index 000000000000..76a84758073a
--- /dev/null
+++ b/fs/xfs/linux-2.6/xfs_aops.c
@@ -0,0 +1,1275 @@
1/*
2 * Copyright (c) 2000-2005 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#include "xfs.h"
34#include "xfs_inum.h"
35#include "xfs_log.h"
36#include "xfs_sb.h"
37#include "xfs_dir.h"
38#include "xfs_dir2.h"
39#include "xfs_trans.h"
40#include "xfs_dmapi.h"
41#include "xfs_mount.h"
42#include "xfs_bmap_btree.h"
43#include "xfs_alloc_btree.h"
44#include "xfs_ialloc_btree.h"
45#include "xfs_alloc.h"
46#include "xfs_btree.h"
47#include "xfs_attr_sf.h"
48#include "xfs_dir_sf.h"
49#include "xfs_dir2_sf.h"
50#include "xfs_dinode.h"
51#include "xfs_inode.h"
52#include "xfs_error.h"
53#include "xfs_rw.h"
54#include "xfs_iomap.h"
55#include <linux/mpage.h>
56#include <linux/writeback.h>
57
58STATIC void xfs_count_page_state(struct page *, int *, int *, int *);
59STATIC void xfs_convert_page(struct inode *, struct page *, xfs_iomap_t *,
60 struct writeback_control *wbc, void *, int, int);
61
62#if defined(XFS_RW_TRACE)
63void
64xfs_page_trace(
65 int tag,
66 struct inode *inode,
67 struct page *page,
68 int mask)
69{
70 xfs_inode_t *ip;
71 bhv_desc_t *bdp;
72 vnode_t *vp = LINVFS_GET_VP(inode);
73 loff_t isize = i_size_read(inode);
74 loff_t offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
75 int delalloc = -1, unmapped = -1, unwritten = -1;
76
77 if (page_has_buffers(page))
78 xfs_count_page_state(page, &delalloc, &unmapped, &unwritten);
79
80 bdp = vn_bhv_lookup(VN_BHV_HEAD(vp), &xfs_vnodeops);
81 ip = XFS_BHVTOI(bdp);
82 if (!ip->i_rwtrace)
83 return;
84
85 ktrace_enter(ip->i_rwtrace,
86 (void *)((unsigned long)tag),
87 (void *)ip,
88 (void *)inode,
89 (void *)page,
90 (void *)((unsigned long)mask),
91 (void *)((unsigned long)((ip->i_d.di_size >> 32) & 0xffffffff)),
92 (void *)((unsigned long)(ip->i_d.di_size & 0xffffffff)),
93 (void *)((unsigned long)((isize >> 32) & 0xffffffff)),
94 (void *)((unsigned long)(isize & 0xffffffff)),
95 (void *)((unsigned long)((offset >> 32) & 0xffffffff)),
96 (void *)((unsigned long)(offset & 0xffffffff)),
97 (void *)((unsigned long)delalloc),
98 (void *)((unsigned long)unmapped),
99 (void *)((unsigned long)unwritten),
100 (void *)NULL,
101 (void *)NULL);
102}
103#else
104#define xfs_page_trace(tag, inode, page, mask)
105#endif
106
107void
108linvfs_unwritten_done(
109 struct buffer_head *bh,
110 int uptodate)
111{
112 xfs_buf_t *pb = (xfs_buf_t *)bh->b_private;
113
114 ASSERT(buffer_unwritten(bh));
115 bh->b_end_io = NULL;
116 clear_buffer_unwritten(bh);
117 if (!uptodate)
118 pagebuf_ioerror(pb, EIO);
119 if (atomic_dec_and_test(&pb->pb_io_remaining) == 1) {
120 pagebuf_iodone(pb, 1, 1);
121 }
122 end_buffer_async_write(bh, uptodate);
123}
124
125/*
126 * Issue transactions to convert a buffer range from unwritten
127 * to written extents (buffered IO).
128 */
129STATIC void
130linvfs_unwritten_convert(
131 xfs_buf_t *bp)
132{
133 vnode_t *vp = XFS_BUF_FSPRIVATE(bp, vnode_t *);
134 int error;
135
136 BUG_ON(atomic_read(&bp->pb_hold) < 1);
137 VOP_BMAP(vp, XFS_BUF_OFFSET(bp), XFS_BUF_SIZE(bp),
138 BMAPI_UNWRITTEN, NULL, NULL, error);
139 XFS_BUF_SET_FSPRIVATE(bp, NULL);
140 XFS_BUF_CLR_IODONE_FUNC(bp);
141 XFS_BUF_UNDATAIO(bp);
142 iput(LINVFS_GET_IP(vp));
143 pagebuf_iodone(bp, 0, 0);
144}
145
146/*
147 * Issue transactions to convert a buffer range from unwritten
148 * to written extents (direct IO).
149 */
150STATIC void
151linvfs_unwritten_convert_direct(
152 struct inode *inode,
153 loff_t offset,
154 ssize_t size,
155 void *private)
156{
157 ASSERT(!private || inode == (struct inode *)private);
158
159 /* private indicates an unwritten extent lay beneath this IO */
160 if (private && size > 0) {
161 vnode_t *vp = LINVFS_GET_VP(inode);
162 int error;
163
164 VOP_BMAP(vp, offset, size, BMAPI_UNWRITTEN, NULL, NULL, error);
165 }
166}
167
168STATIC int
169xfs_map_blocks(
170 struct inode *inode,
171 loff_t offset,
172 ssize_t count,
173 xfs_iomap_t *mapp,
174 int flags)
175{
176 vnode_t *vp = LINVFS_GET_VP(inode);
177 int error, nmaps = 1;
178
179 VOP_BMAP(vp, offset, count, flags, mapp, &nmaps, error);
180 if (!error && (flags & (BMAPI_WRITE|BMAPI_ALLOCATE)))
181 VMODIFY(vp);
182 return -error;
183}
184
185/*
186 * Finds the corresponding mapping in block @map array of the
187 * given @offset within a @page.
188 */
189STATIC xfs_iomap_t *
190xfs_offset_to_map(
191 struct page *page,
192 xfs_iomap_t *iomapp,
193 unsigned long offset)
194{
195 loff_t full_offset; /* offset from start of file */
196
197 ASSERT(offset < PAGE_CACHE_SIZE);
198
199 full_offset = page->index; /* NB: using 64bit number */
200 full_offset <<= PAGE_CACHE_SHIFT; /* offset from file start */
201 full_offset += offset; /* offset from page start */
202
203 if (full_offset < iomapp->iomap_offset)
204 return NULL;
205 if (iomapp->iomap_offset + (iomapp->iomap_bsize -1) >= full_offset)
206 return iomapp;
207 return NULL;
208}
209
210STATIC void
211xfs_map_at_offset(
212 struct page *page,
213 struct buffer_head *bh,
214 unsigned long offset,
215 int block_bits,
216 xfs_iomap_t *iomapp)
217{
218 xfs_daddr_t bn;
219 loff_t delta;
220 int sector_shift;
221
222 ASSERT(!(iomapp->iomap_flags & IOMAP_HOLE));
223 ASSERT(!(iomapp->iomap_flags & IOMAP_DELAY));
224 ASSERT(iomapp->iomap_bn != IOMAP_DADDR_NULL);
225
226 delta = page->index;
227 delta <<= PAGE_CACHE_SHIFT;
228 delta += offset;
229 delta -= iomapp->iomap_offset;
230 delta >>= block_bits;
231
232 sector_shift = block_bits - BBSHIFT;
233 bn = iomapp->iomap_bn >> sector_shift;
234 bn += delta;
235 BUG_ON(!bn && !(iomapp->iomap_flags & IOMAP_REALTIME));
236 ASSERT((bn << sector_shift) >= iomapp->iomap_bn);
237
238 lock_buffer(bh);
239 bh->b_blocknr = bn;
240 bh->b_bdev = iomapp->iomap_target->pbr_bdev;
241 set_buffer_mapped(bh);
242 clear_buffer_delay(bh);
243}
244
245/*
246 * Look for a page at index which is unlocked and contains our
247 * unwritten extent flagged buffers at its head. Returns page
248 * locked and with an extra reference count, and length of the
249 * unwritten extent component on this page that we can write,
250 * in units of filesystem blocks.
251 */
252STATIC struct page *
253xfs_probe_unwritten_page(
254 struct address_space *mapping,
255 pgoff_t index,
256 xfs_iomap_t *iomapp,
257 xfs_buf_t *pb,
258 unsigned long max_offset,
259 unsigned long *fsbs,
260 unsigned int bbits)
261{
262 struct page *page;
263
264 page = find_trylock_page(mapping, index);
265 if (!page)
266 return NULL;
267 if (PageWriteback(page))
268 goto out;
269
270 if (page->mapping && page_has_buffers(page)) {
271 struct buffer_head *bh, *head;
272 unsigned long p_offset = 0;
273
274 *fsbs = 0;
275 bh = head = page_buffers(page);
276 do {
277 if (!buffer_unwritten(bh) || !buffer_uptodate(bh))
278 break;
279 if (!xfs_offset_to_map(page, iomapp, p_offset))
280 break;
281 if (p_offset >= max_offset)
282 break;
283 xfs_map_at_offset(page, bh, p_offset, bbits, iomapp);
284 set_buffer_unwritten_io(bh);
285 bh->b_private = pb;
286 p_offset += bh->b_size;
287 (*fsbs)++;
288 } while ((bh = bh->b_this_page) != head);
289
290 if (p_offset)
291 return page;
292 }
293
294out:
295 unlock_page(page);
296 return NULL;
297}
298
299/*
300 * Look for a page at index which is unlocked and not mapped
301 * yet - clustering for mmap write case.
302 */
303STATIC unsigned int
304xfs_probe_unmapped_page(
305 struct address_space *mapping,
306 pgoff_t index,
307 unsigned int pg_offset)
308{
309 struct page *page;
310 int ret = 0;
311
312 page = find_trylock_page(mapping, index);
313 if (!page)
314 return 0;
315 if (PageWriteback(page))
316 goto out;
317
318 if (page->mapping && PageDirty(page)) {
319 if (page_has_buffers(page)) {
320 struct buffer_head *bh, *head;
321
322 bh = head = page_buffers(page);
323 do {
324 if (buffer_mapped(bh) || !buffer_uptodate(bh))
325 break;
326 ret += bh->b_size;
327 if (ret >= pg_offset)
328 break;
329 } while ((bh = bh->b_this_page) != head);
330 } else
331 ret = PAGE_CACHE_SIZE;
332 }
333
334out:
335 unlock_page(page);
336 return ret;
337}
338
339STATIC unsigned int
340xfs_probe_unmapped_cluster(
341 struct inode *inode,
342 struct page *startpage,
343 struct buffer_head *bh,
344 struct buffer_head *head)
345{
346 pgoff_t tindex, tlast, tloff;
347 unsigned int pg_offset, len, total = 0;
348 struct address_space *mapping = inode->i_mapping;
349
350 /* First sum forwards in this page */
351 do {
352 if (buffer_mapped(bh))
353 break;
354 total += bh->b_size;
355 } while ((bh = bh->b_this_page) != head);
356
357 /* If we reached the end of the page, sum forwards in
358 * following pages.
359 */
360 if (bh == head) {
361 tlast = i_size_read(inode) >> PAGE_CACHE_SHIFT;
362 /* Prune this back to avoid pathological behavior */
363 tloff = min(tlast, startpage->index + 64);
364 for (tindex = startpage->index + 1; tindex < tloff; tindex++) {
365 len = xfs_probe_unmapped_page(mapping, tindex,
366 PAGE_CACHE_SIZE);
367 if (!len)
368 return total;
369 total += len;
370 }
371 if (tindex == tlast &&
372 (pg_offset = i_size_read(inode) & (PAGE_CACHE_SIZE - 1))) {
373 total += xfs_probe_unmapped_page(mapping,
374 tindex, pg_offset);
375 }
376 }
377 return total;
378}
379
380/*
381 * Probe for a given page (index) in the inode and test if it is delayed
382 * and without unwritten buffers. Returns page locked and with an extra
383 * reference count.
384 */
385STATIC struct page *
386xfs_probe_delalloc_page(
387 struct inode *inode,
388 pgoff_t index)
389{
390 struct page *page;
391
392 page = find_trylock_page(inode->i_mapping, index);
393 if (!page)
394 return NULL;
395 if (PageWriteback(page))
396 goto out;
397
398 if (page->mapping && page_has_buffers(page)) {
399 struct buffer_head *bh, *head;
400 int acceptable = 0;
401
402 bh = head = page_buffers(page);
403 do {
404 if (buffer_unwritten(bh)) {
405 acceptable = 0;
406 break;
407 } else if (buffer_delay(bh)) {
408 acceptable = 1;
409 }
410 } while ((bh = bh->b_this_page) != head);
411
412 if (acceptable)
413 return page;
414 }
415
416out:
417 unlock_page(page);
418 return NULL;
419}
420
421STATIC int
422xfs_map_unwritten(
423 struct inode *inode,
424 struct page *start_page,
425 struct buffer_head *head,
426 struct buffer_head *curr,
427 unsigned long p_offset,
428 int block_bits,
429 xfs_iomap_t *iomapp,
430 struct writeback_control *wbc,
431 int startio,
432 int all_bh)
433{
434 struct buffer_head *bh = curr;
435 xfs_iomap_t *tmp;
436 xfs_buf_t *pb;
437 loff_t offset, size;
438 unsigned long nblocks = 0;
439
440 offset = start_page->index;
441 offset <<= PAGE_CACHE_SHIFT;
442 offset += p_offset;
443
444 /* get an "empty" pagebuf to manage IO completion
445 * Proper values will be set before returning */
446 pb = pagebuf_lookup(iomapp->iomap_target, 0, 0, 0);
447 if (!pb)
448 return -EAGAIN;
449
450 /* Take a reference to the inode to prevent it from
451 * being reclaimed while we have outstanding unwritten
452 * extent IO on it.
453 */
454 if ((igrab(inode)) != inode) {
455 pagebuf_free(pb);
456 return -EAGAIN;
457 }
458
459 /* Set the count to 1 initially, this will stop an I/O
460 * completion callout which happens before we have started
461 * all the I/O from calling pagebuf_iodone too early.
462 */
463 atomic_set(&pb->pb_io_remaining, 1);
464
465 /* First map forwards in the page consecutive buffers
466 * covering this unwritten extent
467 */
468 do {
469 if (!buffer_unwritten(bh))
470 break;
471 tmp = xfs_offset_to_map(start_page, iomapp, p_offset);
472 if (!tmp)
473 break;
474 xfs_map_at_offset(start_page, bh, p_offset, block_bits, iomapp);
475 set_buffer_unwritten_io(bh);
476 bh->b_private = pb;
477 p_offset += bh->b_size;
478 nblocks++;
479 } while ((bh = bh->b_this_page) != head);
480
481 atomic_add(nblocks, &pb->pb_io_remaining);
482
483 /* If we reached the end of the page, map forwards in any
484 * following pages which are also covered by this extent.
485 */
486 if (bh == head) {
487 struct address_space *mapping = inode->i_mapping;
488 pgoff_t tindex, tloff, tlast;
489 unsigned long bs;
490 unsigned int pg_offset, bbits = inode->i_blkbits;
491 struct page *page;
492
493 tlast = i_size_read(inode) >> PAGE_CACHE_SHIFT;
494 tloff = (iomapp->iomap_offset + iomapp->iomap_bsize) >> PAGE_CACHE_SHIFT;
495 tloff = min(tlast, tloff);
496 for (tindex = start_page->index + 1; tindex < tloff; tindex++) {
497 page = xfs_probe_unwritten_page(mapping,
498 tindex, iomapp, pb,
499 PAGE_CACHE_SIZE, &bs, bbits);
500 if (!page)
501 break;
502 nblocks += bs;
503 atomic_add(bs, &pb->pb_io_remaining);
504 xfs_convert_page(inode, page, iomapp, wbc, pb,
505 startio, all_bh);
506 /* stop if converting the next page might add
507 * enough blocks that the corresponding byte
508 * count won't fit in our ulong page buf length */
509 if (nblocks >= ((ULONG_MAX - PAGE_SIZE) >> block_bits))
510 goto enough;
511 }
512
513 if (tindex == tlast &&
514 (pg_offset = (i_size_read(inode) & (PAGE_CACHE_SIZE - 1)))) {
515 page = xfs_probe_unwritten_page(mapping,
516 tindex, iomapp, pb,
517 pg_offset, &bs, bbits);
518 if (page) {
519 nblocks += bs;
520 atomic_add(bs, &pb->pb_io_remaining);
521 xfs_convert_page(inode, page, iomapp, wbc, pb,
522 startio, all_bh);
523 if (nblocks >= ((ULONG_MAX - PAGE_SIZE) >> block_bits))
524 goto enough;
525 }
526 }
527 }
528
529enough:
530 size = nblocks; /* NB: using 64bit number here */
531 size <<= block_bits; /* convert fsb's to byte range */
532
533 XFS_BUF_DATAIO(pb);
534 XFS_BUF_ASYNC(pb);
535 XFS_BUF_SET_SIZE(pb, size);
536 XFS_BUF_SET_COUNT(pb, size);
537 XFS_BUF_SET_OFFSET(pb, offset);
538 XFS_BUF_SET_FSPRIVATE(pb, LINVFS_GET_VP(inode));
539 XFS_BUF_SET_IODONE_FUNC(pb, linvfs_unwritten_convert);
540
541 if (atomic_dec_and_test(&pb->pb_io_remaining) == 1) {
542 pagebuf_iodone(pb, 1, 1);
543 }
544
545 return 0;
546}
547
548STATIC void
549xfs_submit_page(
550 struct page *page,
551 struct writeback_control *wbc,
552 struct buffer_head *bh_arr[],
553 int bh_count,
554 int probed_page,
555 int clear_dirty)
556{
557 struct buffer_head *bh;
558 int i;
559
560 BUG_ON(PageWriteback(page));
561 set_page_writeback(page);
562 if (clear_dirty)
563 clear_page_dirty(page);
564 unlock_page(page);
565
566 if (bh_count) {
567 for (i = 0; i < bh_count; i++) {
568 bh = bh_arr[i];
569 mark_buffer_async_write(bh);
570 if (buffer_unwritten(bh))
571 set_buffer_unwritten_io(bh);
572 set_buffer_uptodate(bh);
573 clear_buffer_dirty(bh);
574 }
575
576 for (i = 0; i < bh_count; i++)
577 submit_bh(WRITE, bh_arr[i]);
578
579 if (probed_page && clear_dirty)
580 wbc->nr_to_write--; /* Wrote an "extra" page */
581 } else {
582 end_page_writeback(page);
583 wbc->pages_skipped++; /* We didn't write this page */
584 }
585}
586
587/*
588 * Allocate & map buffers for page given the extent map. Write it out.
589 * except for the original page of a writepage, this is called on
590 * delalloc/unwritten pages only, for the original page it is possible
591 * that the page has no mapping at all.
592 */
593STATIC void
594xfs_convert_page(
595 struct inode *inode,
596 struct page *page,
597 xfs_iomap_t *iomapp,
598 struct writeback_control *wbc,
599 void *private,
600 int startio,
601 int all_bh)
602{
603 struct buffer_head *bh_arr[MAX_BUF_PER_PAGE], *bh, *head;
604 xfs_iomap_t *mp = iomapp, *tmp;
605 unsigned long end, offset;
606 pgoff_t end_index;
607 int i = 0, index = 0;
608 int bbits = inode->i_blkbits;
609
610 end_index = i_size_read(inode) >> PAGE_CACHE_SHIFT;
611 if (page->index < end_index) {
612 end = PAGE_CACHE_SIZE;
613 } else {
614 end = i_size_read(inode) & (PAGE_CACHE_SIZE-1);
615 }
616 bh = head = page_buffers(page);
617 do {
618 offset = i << bbits;
619 if (offset >= end)
620 break;
621 if (!(PageUptodate(page) || buffer_uptodate(bh)))
622 continue;
623 if (buffer_mapped(bh) && all_bh &&
624 !(buffer_unwritten(bh) || buffer_delay(bh))) {
625 if (startio) {
626 lock_buffer(bh);
627 bh_arr[index++] = bh;
628 }
629 continue;
630 }
631 tmp = xfs_offset_to_map(page, mp, offset);
632 if (!tmp)
633 continue;
634 ASSERT(!(tmp->iomap_flags & IOMAP_HOLE));
635 ASSERT(!(tmp->iomap_flags & IOMAP_DELAY));
636
637 /* If this is a new unwritten extent buffer (i.e. one
638 * that we haven't passed in private data for, we must
639 * now map this buffer too.
640 */
641 if (buffer_unwritten(bh) && !bh->b_end_io) {
642 ASSERT(tmp->iomap_flags & IOMAP_UNWRITTEN);
643 xfs_map_unwritten(inode, page, head, bh, offset,
644 bbits, tmp, wbc, startio, all_bh);
645 } else if (! (buffer_unwritten(bh) && buffer_locked(bh))) {
646 xfs_map_at_offset(page, bh, offset, bbits, tmp);
647 if (buffer_unwritten(bh)) {
648 set_buffer_unwritten_io(bh);
649 bh->b_private = private;
650 ASSERT(private);
651 }
652 }
653 if (startio) {
654 bh_arr[index++] = bh;
655 } else {
656 set_buffer_dirty(bh);
657 unlock_buffer(bh);
658 mark_buffer_dirty(bh);
659 }
660 } while (i++, (bh = bh->b_this_page) != head);
661
662 if (startio) {
663 xfs_submit_page(page, wbc, bh_arr, index, 1, index == i);
664 } else {
665 unlock_page(page);
666 }
667}
668
669/*
670 * Convert & write out a cluster of pages in the same extent as defined
671 * by mp and following the start page.
672 */
673STATIC void
674xfs_cluster_write(
675 struct inode *inode,
676 pgoff_t tindex,
677 xfs_iomap_t *iomapp,
678 struct writeback_control *wbc,
679 int startio,
680 int all_bh,
681 pgoff_t tlast)
682{
683 struct page *page;
684
685 for (; tindex <= tlast; tindex++) {
686 page = xfs_probe_delalloc_page(inode, tindex);
687 if (!page)
688 break;
689 xfs_convert_page(inode, page, iomapp, wbc, NULL,
690 startio, all_bh);
691 }
692}
693
694/*
695 * Calling this without startio set means we are being asked to make a dirty
696 * page ready for freeing it's buffers. When called with startio set then
697 * we are coming from writepage.
698 *
699 * When called with startio set it is important that we write the WHOLE
700 * page if possible.
701 * The bh->b_state's cannot know if any of the blocks or which block for
702 * that matter are dirty due to mmap writes, and therefore bh uptodate is
703 * only vaild if the page itself isn't completely uptodate. Some layers
704 * may clear the page dirty flag prior to calling write page, under the
705 * assumption the entire page will be written out; by not writing out the
706 * whole page the page can be reused before all valid dirty data is
707 * written out. Note: in the case of a page that has been dirty'd by
708 * mapwrite and but partially setup by block_prepare_write the
709 * bh->b_states's will not agree and only ones setup by BPW/BCW will have
710 * valid state, thus the whole page must be written out thing.
711 */
712
713STATIC int
714xfs_page_state_convert(
715 struct inode *inode,
716 struct page *page,
717 struct writeback_control *wbc,
718 int startio,
719 int unmapped) /* also implies page uptodate */
720{
721 struct buffer_head *bh_arr[MAX_BUF_PER_PAGE], *bh, *head;
722 xfs_iomap_t *iomp, iomap;
723 loff_t offset;
724 unsigned long p_offset = 0;
725 __uint64_t end_offset;
726 pgoff_t end_index, last_index, tlast;
727 int len, err, i, cnt = 0, uptodate = 1;
728 int flags = startio ? 0 : BMAPI_TRYLOCK;
729 int page_dirty, delalloc = 0;
730
731 /* Is this page beyond the end of the file? */
732 offset = i_size_read(inode);
733 end_index = offset >> PAGE_CACHE_SHIFT;
734 last_index = (offset - 1) >> PAGE_CACHE_SHIFT;
735 if (page->index >= end_index) {
736 if ((page->index >= end_index + 1) ||
737 !(i_size_read(inode) & (PAGE_CACHE_SIZE - 1))) {
738 err = -EIO;
739 goto error;
740 }
741 }
742
743 offset = (loff_t)page->index << PAGE_CACHE_SHIFT;
744 end_offset = min_t(unsigned long long,
745 offset + PAGE_CACHE_SIZE, i_size_read(inode));
746
747 bh = head = page_buffers(page);
748 iomp = NULL;
749
750 /*
751 * page_dirty is initially a count of buffers on the page and
752 * is decrememted as we move each into a cleanable state.
753 */
754 len = bh->b_size;
755 page_dirty = PAGE_CACHE_SIZE / len;
756
757 do {
758 if (offset >= end_offset)
759 break;
760 if (!buffer_uptodate(bh))
761 uptodate = 0;
762 if (!(PageUptodate(page) || buffer_uptodate(bh)) && !startio)
763 continue;
764
765 if (iomp) {
766 iomp = xfs_offset_to_map(page, &iomap, p_offset);
767 }
768
769 /*
770 * First case, map an unwritten extent and prepare for
771 * extent state conversion transaction on completion.
772 */
773 if (buffer_unwritten(bh)) {
774 if (!startio)
775 continue;
776 if (!iomp) {
777 err = xfs_map_blocks(inode, offset, len, &iomap,
778 BMAPI_READ|BMAPI_IGNSTATE);
779 if (err) {
780 goto error;
781 }
782 iomp = xfs_offset_to_map(page, &iomap,
783 p_offset);
784 }
785 if (iomp) {
786 if (!bh->b_end_io) {
787 err = xfs_map_unwritten(inode, page,
788 head, bh, p_offset,
789 inode->i_blkbits, iomp,
790 wbc, startio, unmapped);
791 if (err) {
792 goto error;
793 }
794 } else {
795 set_bit(BH_Lock, &bh->b_state);
796 }
797 BUG_ON(!buffer_locked(bh));
798 bh_arr[cnt++] = bh;
799 page_dirty--;
800 }
801 /*
802 * Second case, allocate space for a delalloc buffer.
803 * We can return EAGAIN here in the release page case.
804 */
805 } else if (buffer_delay(bh)) {
806 if (!iomp) {
807 delalloc = 1;
808 err = xfs_map_blocks(inode, offset, len, &iomap,
809 BMAPI_ALLOCATE | flags);
810 if (err) {
811 goto error;
812 }
813 iomp = xfs_offset_to_map(page, &iomap,
814 p_offset);
815 }
816 if (iomp) {
817 xfs_map_at_offset(page, bh, p_offset,
818 inode->i_blkbits, iomp);
819 if (startio) {
820 bh_arr[cnt++] = bh;
821 } else {
822 set_buffer_dirty(bh);
823 unlock_buffer(bh);
824 mark_buffer_dirty(bh);
825 }
826 page_dirty--;
827 }
828 } else if ((buffer_uptodate(bh) || PageUptodate(page)) &&
829 (unmapped || startio)) {
830
831 if (!buffer_mapped(bh)) {
832 int size;
833
834 /*
835 * Getting here implies an unmapped buffer
836 * was found, and we are in a path where we
837 * need to write the whole page out.
838 */
839 if (!iomp) {
840 size = xfs_probe_unmapped_cluster(
841 inode, page, bh, head);
842 err = xfs_map_blocks(inode, offset,
843 size, &iomap,
844 BMAPI_WRITE|BMAPI_MMAP);
845 if (err) {
846 goto error;
847 }
848 iomp = xfs_offset_to_map(page, &iomap,
849 p_offset);
850 }
851 if (iomp) {
852 xfs_map_at_offset(page,
853 bh, p_offset,
854 inode->i_blkbits, iomp);
855 if (startio) {
856 bh_arr[cnt++] = bh;
857 } else {
858 set_buffer_dirty(bh);
859 unlock_buffer(bh);
860 mark_buffer_dirty(bh);
861 }
862 page_dirty--;
863 }
864 } else if (startio) {
865 if (buffer_uptodate(bh) &&
866 !test_and_set_bit(BH_Lock, &bh->b_state)) {
867 bh_arr[cnt++] = bh;
868 page_dirty--;
869 }
870 }
871 }
872 } while (offset += len, p_offset += len,
873 ((bh = bh->b_this_page) != head));
874
875 if (uptodate && bh == head)
876 SetPageUptodate(page);
877
878 if (startio)
879 xfs_submit_page(page, wbc, bh_arr, cnt, 0, 1);
880
881 if (iomp) {
882 tlast = (iomp->iomap_offset + iomp->iomap_bsize - 1) >>
883 PAGE_CACHE_SHIFT;
884 if (delalloc && (tlast > last_index))
885 tlast = last_index;
886 xfs_cluster_write(inode, page->index + 1, iomp, wbc,
887 startio, unmapped, tlast);
888 }
889
890 return page_dirty;
891
892error:
893 for (i = 0; i < cnt; i++) {
894 unlock_buffer(bh_arr[i]);
895 }
896
897 /*
898 * If it's delalloc and we have nowhere to put it,
899 * throw it away, unless the lower layers told
900 * us to try again.
901 */
902 if (err != -EAGAIN) {
903 if (!unmapped) {
904 block_invalidatepage(page, 0);
905 }
906 ClearPageUptodate(page);
907 }
908 return err;
909}
910
911STATIC int
912__linvfs_get_block(
913 struct inode *inode,
914 sector_t iblock,
915 unsigned long blocks,
916 struct buffer_head *bh_result,
917 int create,
918 int direct,
919 bmapi_flags_t flags)
920{
921 vnode_t *vp = LINVFS_GET_VP(inode);
922 xfs_iomap_t iomap;
923 int retpbbm = 1;
924 int error;
925 ssize_t size;
926 loff_t offset = (loff_t)iblock << inode->i_blkbits;
927
928 if (blocks)
929 size = blocks << inode->i_blkbits;
930 else
931 size = 1 << inode->i_blkbits;
932
933 VOP_BMAP(vp, offset, size,
934 create ? flags : BMAPI_READ, &iomap, &retpbbm, error);
935 if (error)
936 return -error;
937
938 if (retpbbm == 0)
939 return 0;
940
941 if (iomap.iomap_bn != IOMAP_DADDR_NULL) {
942 xfs_daddr_t bn;
943 loff_t delta;
944
945 /* For unwritten extents do not report a disk address on
946 * the read case (treat as if we're reading into a hole).
947 */
948 if (create || !(iomap.iomap_flags & IOMAP_UNWRITTEN)) {
949 delta = offset - iomap.iomap_offset;
950 delta >>= inode->i_blkbits;
951
952 bn = iomap.iomap_bn >> (inode->i_blkbits - BBSHIFT);
953 bn += delta;
954 BUG_ON(!bn && !(iomap.iomap_flags & IOMAP_REALTIME));
955 bh_result->b_blocknr = bn;
956 set_buffer_mapped(bh_result);
957 }
958 if (create && (iomap.iomap_flags & IOMAP_UNWRITTEN)) {
959 if (direct)
960 bh_result->b_private = inode;
961 set_buffer_unwritten(bh_result);
962 set_buffer_delay(bh_result);
963 }
964 }
965
966 /* If this is a realtime file, data might be on a new device */
967 bh_result->b_bdev = iomap.iomap_target->pbr_bdev;
968
969 /* If we previously allocated a block out beyond eof and
970 * we are now coming back to use it then we will need to
971 * flag it as new even if it has a disk address.
972 */
973 if (create &&
974 ((!buffer_mapped(bh_result) && !buffer_uptodate(bh_result)) ||
975 (offset >= i_size_read(inode)) || (iomap.iomap_flags & IOMAP_NEW))) {
976 set_buffer_new(bh_result);
977 }
978
979 if (iomap.iomap_flags & IOMAP_DELAY) {
980 BUG_ON(direct);
981 if (create) {
982 set_buffer_uptodate(bh_result);
983 set_buffer_mapped(bh_result);
984 set_buffer_delay(bh_result);
985 }
986 }
987
988 if (blocks) {
989 bh_result->b_size = (ssize_t)min(
990 (loff_t)(iomap.iomap_bsize - iomap.iomap_delta),
991 (loff_t)(blocks << inode->i_blkbits));
992 }
993
994 return 0;
995}
996
997int
998linvfs_get_block(
999 struct inode *inode,
1000 sector_t iblock,
1001 struct buffer_head *bh_result,
1002 int create)
1003{
1004 return __linvfs_get_block(inode, iblock, 0, bh_result,
1005 create, 0, BMAPI_WRITE);
1006}
1007
1008STATIC int
1009linvfs_get_blocks_direct(
1010 struct inode *inode,
1011 sector_t iblock,
1012 unsigned long max_blocks,
1013 struct buffer_head *bh_result,
1014 int create)
1015{
1016 return __linvfs_get_block(inode, iblock, max_blocks, bh_result,
1017 create, 1, BMAPI_WRITE|BMAPI_DIRECT);
1018}
1019
1020STATIC ssize_t
1021linvfs_direct_IO(
1022 int rw,
1023 struct kiocb *iocb,
1024 const struct iovec *iov,
1025 loff_t offset,
1026 unsigned long nr_segs)
1027{
1028 struct file *file = iocb->ki_filp;
1029 struct inode *inode = file->f_mapping->host;
1030 vnode_t *vp = LINVFS_GET_VP(inode);
1031 xfs_iomap_t iomap;
1032 int maps = 1;
1033 int error;
1034
1035 VOP_BMAP(vp, offset, 0, BMAPI_DEVICE, &iomap, &maps, error);
1036 if (error)
1037 return -error;
1038
1039 return blockdev_direct_IO_own_locking(rw, iocb, inode,
1040 iomap.iomap_target->pbr_bdev,
1041 iov, offset, nr_segs,
1042 linvfs_get_blocks_direct,
1043 linvfs_unwritten_convert_direct);
1044}
1045
1046
1047STATIC sector_t
1048linvfs_bmap(
1049 struct address_space *mapping,
1050 sector_t block)
1051{
1052 struct inode *inode = (struct inode *)mapping->host;
1053 vnode_t *vp = LINVFS_GET_VP(inode);
1054 int error;
1055
1056 vn_trace_entry(vp, "linvfs_bmap", (inst_t *)__return_address);
1057
1058 VOP_RWLOCK(vp, VRWLOCK_READ);
1059 VOP_FLUSH_PAGES(vp, (xfs_off_t)0, -1, 0, FI_REMAPF, error);
1060 VOP_RWUNLOCK(vp, VRWLOCK_READ);
1061 return generic_block_bmap(mapping, block, linvfs_get_block);
1062}
1063
1064STATIC int
1065linvfs_readpage(
1066 struct file *unused,
1067 struct page *page)
1068{
1069 return mpage_readpage(page, linvfs_get_block);
1070}
1071
1072STATIC int
1073linvfs_readpages(
1074 struct file *unused,
1075 struct address_space *mapping,
1076 struct list_head *pages,
1077 unsigned nr_pages)
1078{
1079 return mpage_readpages(mapping, pages, nr_pages, linvfs_get_block);
1080}
1081
1082STATIC void
1083xfs_count_page_state(
1084 struct page *page,
1085 int *delalloc,
1086 int *unmapped,
1087 int *unwritten)
1088{
1089 struct buffer_head *bh, *head;
1090
1091 *delalloc = *unmapped = *unwritten = 0;
1092
1093 bh = head = page_buffers(page);
1094 do {
1095 if (buffer_uptodate(bh) && !buffer_mapped(bh))
1096 (*unmapped) = 1;
1097 else if (buffer_unwritten(bh) && !buffer_delay(bh))
1098 clear_buffer_unwritten(bh);
1099 else if (buffer_unwritten(bh))
1100 (*unwritten) = 1;
1101 else if (buffer_delay(bh))
1102 (*delalloc) = 1;
1103 } while ((bh = bh->b_this_page) != head);
1104}
1105
1106
1107/*
1108 * writepage: Called from one of two places:
1109 *
1110 * 1. we are flushing a delalloc buffer head.
1111 *
1112 * 2. we are writing out a dirty page. Typically the page dirty
1113 * state is cleared before we get here. In this case is it
1114 * conceivable we have no buffer heads.
1115 *
1116 * For delalloc space on the page we need to allocate space and
1117 * flush it. For unmapped buffer heads on the page we should
1118 * allocate space if the page is uptodate. For any other dirty
1119 * buffer heads on the page we should flush them.
1120 *
1121 * If we detect that a transaction would be required to flush
1122 * the page, we have to check the process flags first, if we
1123 * are already in a transaction or disk I/O during allocations
1124 * is off, we need to fail the writepage and redirty the page.
1125 */
1126
1127STATIC int
1128linvfs_writepage(
1129 struct page *page,
1130 struct writeback_control *wbc)
1131{
1132 int error;
1133 int need_trans;
1134 int delalloc, unmapped, unwritten;
1135 struct inode *inode = page->mapping->host;
1136
1137 xfs_page_trace(XFS_WRITEPAGE_ENTER, inode, page, 0);
1138
1139 /*
1140 * We need a transaction if:
1141 * 1. There are delalloc buffers on the page
1142 * 2. The page is uptodate and we have unmapped buffers
1143 * 3. The page is uptodate and we have no buffers
1144 * 4. There are unwritten buffers on the page
1145 */
1146
1147 if (!page_has_buffers(page)) {
1148 unmapped = 1;
1149 need_trans = 1;
1150 } else {
1151 xfs_count_page_state(page, &delalloc, &unmapped, &unwritten);
1152 if (!PageUptodate(page))
1153 unmapped = 0;
1154 need_trans = delalloc + unmapped + unwritten;
1155 }
1156
1157 /*
1158 * If we need a transaction and the process flags say
1159 * we are already in a transaction, or no IO is allowed
1160 * then mark the page dirty again and leave the page
1161 * as is.
1162 */
1163 if (PFLAGS_TEST_FSTRANS() && need_trans)
1164 goto out_fail;
1165
1166 /*
1167 * Delay hooking up buffer heads until we have
1168 * made our go/no-go decision.
1169 */
1170 if (!page_has_buffers(page))
1171 create_empty_buffers(page, 1 << inode->i_blkbits, 0);
1172
1173 /*
1174 * Convert delayed allocate, unwritten or unmapped space
1175 * to real space and flush out to disk.
1176 */
1177 error = xfs_page_state_convert(inode, page, wbc, 1, unmapped);
1178 if (error == -EAGAIN)
1179 goto out_fail;
1180 if (unlikely(error < 0))
1181 goto out_unlock;
1182
1183 return 0;
1184
1185out_fail:
1186 redirty_page_for_writepage(wbc, page);
1187 unlock_page(page);
1188 return 0;
1189out_unlock:
1190 unlock_page(page);
1191 return error;
1192}
1193
1194/*
1195 * Called to move a page into cleanable state - and from there
1196 * to be released. Possibly the page is already clean. We always
1197 * have buffer heads in this call.
1198 *
1199 * Returns 0 if the page is ok to release, 1 otherwise.
1200 *
1201 * Possible scenarios are:
1202 *
1203 * 1. We are being called to release a page which has been written
1204 * to via regular I/O. buffer heads will be dirty and possibly
1205 * delalloc. If no delalloc buffer heads in this case then we
1206 * can just return zero.
1207 *
1208 * 2. We are called to release a page which has been written via
1209 * mmap, all we need to do is ensure there is no delalloc
1210 * state in the buffer heads, if not we can let the caller
1211 * free them and we should come back later via writepage.
1212 */
1213STATIC int
1214linvfs_release_page(
1215 struct page *page,
1216 int gfp_mask)
1217{
1218 struct inode *inode = page->mapping->host;
1219 int dirty, delalloc, unmapped, unwritten;
1220 struct writeback_control wbc = {
1221 .sync_mode = WB_SYNC_ALL,
1222 .nr_to_write = 1,
1223 };
1224
1225 xfs_page_trace(XFS_RELEASEPAGE_ENTER, inode, page, gfp_mask);
1226
1227 xfs_count_page_state(page, &delalloc, &unmapped, &unwritten);
1228 if (!delalloc && !unwritten)
1229 goto free_buffers;
1230
1231 if (!(gfp_mask & __GFP_FS))
1232 return 0;
1233
1234 /* If we are already inside a transaction or the thread cannot
1235 * do I/O, we cannot release this page.
1236 */
1237 if (PFLAGS_TEST_FSTRANS())
1238 return 0;
1239
1240 /*
1241 * Convert delalloc space to real space, do not flush the
1242 * data out to disk, that will be done by the caller.
1243 * Never need to allocate space here - we will always
1244 * come back to writepage in that case.
1245 */
1246 dirty = xfs_page_state_convert(inode, page, &wbc, 0, 0);
1247 if (dirty == 0 && !unwritten)
1248 goto free_buffers;
1249 return 0;
1250
1251free_buffers:
1252 return try_to_free_buffers(page);
1253}
1254
1255STATIC int
1256linvfs_prepare_write(
1257 struct file *file,
1258 struct page *page,
1259 unsigned int from,
1260 unsigned int to)
1261{
1262 return block_prepare_write(page, from, to, linvfs_get_block);
1263}
1264
1265struct address_space_operations linvfs_aops = {
1266 .readpage = linvfs_readpage,
1267 .readpages = linvfs_readpages,
1268 .writepage = linvfs_writepage,
1269 .sync_page = block_sync_page,
1270 .releasepage = linvfs_release_page,
1271 .prepare_write = linvfs_prepare_write,
1272 .commit_write = generic_commit_write,
1273 .bmap = linvfs_bmap,
1274 .direct_IO = linvfs_direct_IO,
1275};
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-27 05:21:33 -0500