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Merge branch 'allocator' of git://git.kernel.org/pub/scm/linux/kernel/git/arne/btrfs...
[deliverable/linux.git] / fs / exofs / inode.c
1 /*
2 * Copyright (C) 2005, 2006
3 * Avishay Traeger (avishay@gmail.com)
4 * Copyright (C) 2008, 2009
5 * Boaz Harrosh <bharrosh@panasas.com>
6 *
7 * Copyrights for code taken from ext2:
8 * Copyright (C) 1992, 1993, 1994, 1995
9 * Remy Card (card@masi.ibp.fr)
10 * Laboratoire MASI - Institut Blaise Pascal
11 * Universite Pierre et Marie Curie (Paris VI)
12 * from
13 * linux/fs/minix/inode.c
14 * Copyright (C) 1991, 1992 Linus Torvalds
15 *
16 * This file is part of exofs.
17 *
18 * exofs is free software; you can redistribute it and/or modify
19 * it under the terms of the GNU General Public License as published by
20 * the Free Software Foundation. Since it is based on ext2, and the only
21 * valid version of GPL for the Linux kernel is version 2, the only valid
22 * version of GPL for exofs is version 2.
23 *
24 * exofs is distributed in the hope that it will be useful,
25 * but WITHOUT ANY WARRANTY; without even the implied warranty of
26 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
27 * GNU General Public License for more details.
28 *
29 * You should have received a copy of the GNU General Public License
30 * along with exofs; if not, write to the Free Software
31 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
32 */
33
34 #include <linux/slab.h>
35
36 #include "exofs.h"
37
38 #define EXOFS_DBGMSG2(M...) do {} while (0)
39
40 enum { BIO_MAX_PAGES_KMALLOC =
41 (PAGE_SIZE - sizeof(struct bio)) / sizeof(struct bio_vec),
42 MAX_PAGES_KMALLOC =
43 PAGE_SIZE / sizeof(struct page *),
44 };
45
46 unsigned exofs_max_io_pages(struct exofs_layout *layout,
47 unsigned expected_pages)
48 {
49 unsigned pages = min_t(unsigned, expected_pages, MAX_PAGES_KMALLOC);
50
51 /* TODO: easily support bio chaining */
52 pages = min_t(unsigned, pages,
53 layout->group_width * BIO_MAX_PAGES_KMALLOC);
54 return pages;
55 }
56
57 struct page_collect {
58 struct exofs_sb_info *sbi;
59 struct inode *inode;
60 unsigned expected_pages;
61 struct exofs_io_state *ios;
62
63 struct page **pages;
64 unsigned alloc_pages;
65 unsigned nr_pages;
66 unsigned long length;
67 loff_t pg_first; /* keep 64bit also in 32-arches */
68 bool read_4_write; /* This means two things: that the read is sync
69 * And the pages should not be unlocked.
70 */
71 };
72
73 static void _pcol_init(struct page_collect *pcol, unsigned expected_pages,
74 struct inode *inode)
75 {
76 struct exofs_sb_info *sbi = inode->i_sb->s_fs_info;
77
78 pcol->sbi = sbi;
79 pcol->inode = inode;
80 pcol->expected_pages = expected_pages;
81
82 pcol->ios = NULL;
83 pcol->pages = NULL;
84 pcol->alloc_pages = 0;
85 pcol->nr_pages = 0;
86 pcol->length = 0;
87 pcol->pg_first = -1;
88 pcol->read_4_write = false;
89 }
90
91 static void _pcol_reset(struct page_collect *pcol)
92 {
93 pcol->expected_pages -= min(pcol->nr_pages, pcol->expected_pages);
94
95 pcol->pages = NULL;
96 pcol->alloc_pages = 0;
97 pcol->nr_pages = 0;
98 pcol->length = 0;
99 pcol->pg_first = -1;
100 pcol->ios = NULL;
101
102 /* this is probably the end of the loop but in writes
103 * it might not end here. don't be left with nothing
104 */
105 if (!pcol->expected_pages)
106 pcol->expected_pages = MAX_PAGES_KMALLOC;
107 }
108
109 static int pcol_try_alloc(struct page_collect *pcol)
110 {
111 unsigned pages;
112
113 if (!pcol->ios) { /* First time allocate io_state */
114 int ret = exofs_get_io_state(&pcol->sbi->layout, &pcol->ios);
115
116 if (ret)
117 return ret;
118 }
119
120 /* TODO: easily support bio chaining */
121 pages = exofs_max_io_pages(&pcol->sbi->layout, pcol->expected_pages);
122
123 for (; pages; pages >>= 1) {
124 pcol->pages = kmalloc(pages * sizeof(struct page *),
125 GFP_KERNEL);
126 if (likely(pcol->pages)) {
127 pcol->alloc_pages = pages;
128 return 0;
129 }
130 }
131
132 EXOFS_ERR("Failed to kmalloc expected_pages=%u\n",
133 pcol->expected_pages);
134 return -ENOMEM;
135 }
136
137 static void pcol_free(struct page_collect *pcol)
138 {
139 kfree(pcol->pages);
140 pcol->pages = NULL;
141
142 if (pcol->ios) {
143 exofs_put_io_state(pcol->ios);
144 pcol->ios = NULL;
145 }
146 }
147
148 static int pcol_add_page(struct page_collect *pcol, struct page *page,
149 unsigned len)
150 {
151 if (unlikely(pcol->nr_pages >= pcol->alloc_pages))
152 return -ENOMEM;
153
154 pcol->pages[pcol->nr_pages++] = page;
155 pcol->length += len;
156 return 0;
157 }
158
159 static int update_read_page(struct page *page, int ret)
160 {
161 if (ret == 0) {
162 /* Everything is OK */
163 SetPageUptodate(page);
164 if (PageError(page))
165 ClearPageError(page);
166 } else if (ret == -EFAULT) {
167 /* In this case we were trying to read something that wasn't on
168 * disk yet - return a page full of zeroes. This should be OK,
169 * because the object should be empty (if there was a write
170 * before this read, the read would be waiting with the page
171 * locked */
172 clear_highpage(page);
173
174 SetPageUptodate(page);
175 if (PageError(page))
176 ClearPageError(page);
177 ret = 0; /* recovered error */
178 EXOFS_DBGMSG("recovered read error\n");
179 } else /* Error */
180 SetPageError(page);
181
182 return ret;
183 }
184
185 static void update_write_page(struct page *page, int ret)
186 {
187 if (ret) {
188 mapping_set_error(page->mapping, ret);
189 SetPageError(page);
190 }
191 end_page_writeback(page);
192 }
193
194 /* Called at the end of reads, to optionally unlock pages and update their
195 * status.
196 */
197 static int __readpages_done(struct page_collect *pcol)
198 {
199 int i;
200 u64 resid;
201 u64 good_bytes;
202 u64 length = 0;
203 int ret = exofs_check_io(pcol->ios, &resid);
204
205 if (likely(!ret))
206 good_bytes = pcol->length;
207 else
208 good_bytes = pcol->length - resid;
209
210 EXOFS_DBGMSG2("readpages_done(0x%lx) good_bytes=0x%llx"
211 " length=0x%lx nr_pages=%u\n",
212 pcol->inode->i_ino, _LLU(good_bytes), pcol->length,
213 pcol->nr_pages);
214
215 for (i = 0; i < pcol->nr_pages; i++) {
216 struct page *page = pcol->pages[i];
217 struct inode *inode = page->mapping->host;
218 int page_stat;
219
220 if (inode != pcol->inode)
221 continue; /* osd might add more pages at end */
222
223 if (likely(length < good_bytes))
224 page_stat = 0;
225 else
226 page_stat = ret;
227
228 EXOFS_DBGMSG2(" readpages_done(0x%lx, 0x%lx) %s\n",
229 inode->i_ino, page->index,
230 page_stat ? "bad_bytes" : "good_bytes");
231
232 ret = update_read_page(page, page_stat);
233 if (!pcol->read_4_write)
234 unlock_page(page);
235 length += PAGE_SIZE;
236 }
237
238 pcol_free(pcol);
239 EXOFS_DBGMSG2("readpages_done END\n");
240 return ret;
241 }
242
243 /* callback of async reads */
244 static void readpages_done(struct exofs_io_state *ios, void *p)
245 {
246 struct page_collect *pcol = p;
247
248 __readpages_done(pcol);
249 atomic_dec(&pcol->sbi->s_curr_pending);
250 kfree(pcol);
251 }
252
253 static void _unlock_pcol_pages(struct page_collect *pcol, int ret, int rw)
254 {
255 int i;
256
257 for (i = 0; i < pcol->nr_pages; i++) {
258 struct page *page = pcol->pages[i];
259
260 if (rw == READ)
261 update_read_page(page, ret);
262 else
263 update_write_page(page, ret);
264
265 unlock_page(page);
266 }
267 }
268
269 static int read_exec(struct page_collect *pcol)
270 {
271 struct exofs_i_info *oi = exofs_i(pcol->inode);
272 struct exofs_io_state *ios = pcol->ios;
273 struct page_collect *pcol_copy = NULL;
274 int ret;
275
276 if (!pcol->pages)
277 return 0;
278
279 ios->pages = pcol->pages;
280 ios->nr_pages = pcol->nr_pages;
281 ios->length = pcol->length;
282 ios->offset = pcol->pg_first << PAGE_CACHE_SHIFT;
283
284 if (pcol->read_4_write) {
285 exofs_oi_read(oi, pcol->ios);
286 return __readpages_done(pcol);
287 }
288
289 pcol_copy = kmalloc(sizeof(*pcol_copy), GFP_KERNEL);
290 if (!pcol_copy) {
291 ret = -ENOMEM;
292 goto err;
293 }
294
295 *pcol_copy = *pcol;
296 ios->done = readpages_done;
297 ios->private = pcol_copy;
298 ret = exofs_oi_read(oi, ios);
299 if (unlikely(ret))
300 goto err;
301
302 atomic_inc(&pcol->sbi->s_curr_pending);
303
304 EXOFS_DBGMSG2("read_exec obj=0x%llx start=0x%llx length=0x%lx\n",
305 ios->obj.id, _LLU(ios->offset), pcol->length);
306
307 /* pages ownership was passed to pcol_copy */
308 _pcol_reset(pcol);
309 return 0;
310
311 err:
312 if (!pcol->read_4_write)
313 _unlock_pcol_pages(pcol, ret, READ);
314
315 pcol_free(pcol);
316
317 kfree(pcol_copy);
318 return ret;
319 }
320
321 /* readpage_strip is called either directly from readpage() or by the VFS from
322 * within read_cache_pages(), to add one more page to be read. It will try to
323 * collect as many contiguous pages as posible. If a discontinuity is
324 * encountered, or it runs out of resources, it will submit the previous segment
325 * and will start a new collection. Eventually caller must submit the last
326 * segment if present.
327 */
328 static int readpage_strip(void *data, struct page *page)
329 {
330 struct page_collect *pcol = data;
331 struct inode *inode = pcol->inode;
332 struct exofs_i_info *oi = exofs_i(inode);
333 loff_t i_size = i_size_read(inode);
334 pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
335 size_t len;
336 int ret;
337
338 /* FIXME: Just for debugging, will be removed */
339 if (PageUptodate(page))
340 EXOFS_ERR("PageUptodate(0x%lx, 0x%lx)\n", pcol->inode->i_ino,
341 page->index);
342
343 if (page->index < end_index)
344 len = PAGE_CACHE_SIZE;
345 else if (page->index == end_index)
346 len = i_size & ~PAGE_CACHE_MASK;
347 else
348 len = 0;
349
350 if (!len || !obj_created(oi)) {
351 /* this will be out of bounds, or doesn't exist yet.
352 * Current page is cleared and the request is split
353 */
354 clear_highpage(page);
355
356 SetPageUptodate(page);
357 if (PageError(page))
358 ClearPageError(page);
359
360 if (!pcol->read_4_write)
361 unlock_page(page);
362 EXOFS_DBGMSG("readpage_strip(0x%lx) empty page len=%zx "
363 "read_4_write=%d index=0x%lx end_index=0x%lx "
364 "splitting\n", inode->i_ino, len,
365 pcol->read_4_write, page->index, end_index);
366
367 return read_exec(pcol);
368 }
369
370 try_again:
371
372 if (unlikely(pcol->pg_first == -1)) {
373 pcol->pg_first = page->index;
374 } else if (unlikely((pcol->pg_first + pcol->nr_pages) !=
375 page->index)) {
376 /* Discontinuity detected, split the request */
377 ret = read_exec(pcol);
378 if (unlikely(ret))
379 goto fail;
380 goto try_again;
381 }
382
383 if (!pcol->pages) {
384 ret = pcol_try_alloc(pcol);
385 if (unlikely(ret))
386 goto fail;
387 }
388
389 if (len != PAGE_CACHE_SIZE)
390 zero_user(page, len, PAGE_CACHE_SIZE - len);
391
392 EXOFS_DBGMSG2(" readpage_strip(0x%lx, 0x%lx) len=0x%zx\n",
393 inode->i_ino, page->index, len);
394
395 ret = pcol_add_page(pcol, page, len);
396 if (ret) {
397 EXOFS_DBGMSG2("Failed pcol_add_page pages[i]=%p "
398 "this_len=0x%zx nr_pages=%u length=0x%lx\n",
399 page, len, pcol->nr_pages, pcol->length);
400
401 /* split the request, and start again with current page */
402 ret = read_exec(pcol);
403 if (unlikely(ret))
404 goto fail;
405
406 goto try_again;
407 }
408
409 return 0;
410
411 fail:
412 /* SetPageError(page); ??? */
413 unlock_page(page);
414 return ret;
415 }
416
417 static int exofs_readpages(struct file *file, struct address_space *mapping,
418 struct list_head *pages, unsigned nr_pages)
419 {
420 struct page_collect pcol;
421 int ret;
422
423 _pcol_init(&pcol, nr_pages, mapping->host);
424
425 ret = read_cache_pages(mapping, pages, readpage_strip, &pcol);
426 if (ret) {
427 EXOFS_ERR("read_cache_pages => %d\n", ret);
428 return ret;
429 }
430
431 return read_exec(&pcol);
432 }
433
434 static int _readpage(struct page *page, bool read_4_write)
435 {
436 struct page_collect pcol;
437 int ret;
438
439 _pcol_init(&pcol, 1, page->mapping->host);
440
441 pcol.read_4_write = read_4_write;
442 ret = readpage_strip(&pcol, page);
443 if (ret) {
444 EXOFS_ERR("_readpage => %d\n", ret);
445 return ret;
446 }
447
448 return read_exec(&pcol);
449 }
450
451 /*
452 * We don't need the file
453 */
454 static int exofs_readpage(struct file *file, struct page *page)
455 {
456 return _readpage(page, false);
457 }
458
459 /* Callback for osd_write. All writes are asynchronous */
460 static void writepages_done(struct exofs_io_state *ios, void *p)
461 {
462 struct page_collect *pcol = p;
463 int i;
464 u64 resid;
465 u64 good_bytes;
466 u64 length = 0;
467 int ret = exofs_check_io(ios, &resid);
468
469 atomic_dec(&pcol->sbi->s_curr_pending);
470
471 if (likely(!ret))
472 good_bytes = pcol->length;
473 else
474 good_bytes = pcol->length - resid;
475
476 EXOFS_DBGMSG2("writepages_done(0x%lx) good_bytes=0x%llx"
477 " length=0x%lx nr_pages=%u\n",
478 pcol->inode->i_ino, _LLU(good_bytes), pcol->length,
479 pcol->nr_pages);
480
481 for (i = 0; i < pcol->nr_pages; i++) {
482 struct page *page = pcol->pages[i];
483 struct inode *inode = page->mapping->host;
484 int page_stat;
485
486 if (inode != pcol->inode)
487 continue; /* osd might add more pages to a bio */
488
489 if (likely(length < good_bytes))
490 page_stat = 0;
491 else
492 page_stat = ret;
493
494 update_write_page(page, page_stat);
495 unlock_page(page);
496 EXOFS_DBGMSG2(" writepages_done(0x%lx, 0x%lx) status=%d\n",
497 inode->i_ino, page->index, page_stat);
498
499 length += PAGE_SIZE;
500 }
501
502 pcol_free(pcol);
503 kfree(pcol);
504 EXOFS_DBGMSG2("writepages_done END\n");
505 }
506
507 static int write_exec(struct page_collect *pcol)
508 {
509 struct exofs_i_info *oi = exofs_i(pcol->inode);
510 struct exofs_io_state *ios = pcol->ios;
511 struct page_collect *pcol_copy = NULL;
512 int ret;
513
514 if (!pcol->pages)
515 return 0;
516
517 pcol_copy = kmalloc(sizeof(*pcol_copy), GFP_KERNEL);
518 if (!pcol_copy) {
519 EXOFS_ERR("write_exec: Failed to kmalloc(pcol)\n");
520 ret = -ENOMEM;
521 goto err;
522 }
523
524 *pcol_copy = *pcol;
525
526 ios->pages = pcol_copy->pages;
527 ios->nr_pages = pcol_copy->nr_pages;
528 ios->offset = pcol_copy->pg_first << PAGE_CACHE_SHIFT;
529 ios->length = pcol_copy->length;
530 ios->done = writepages_done;
531 ios->private = pcol_copy;
532
533 ret = exofs_oi_write(oi, ios);
534 if (unlikely(ret)) {
535 EXOFS_ERR("write_exec: exofs_oi_write() Failed\n");
536 goto err;
537 }
538
539 atomic_inc(&pcol->sbi->s_curr_pending);
540 EXOFS_DBGMSG2("write_exec(0x%lx, 0x%llx) start=0x%llx length=0x%lx\n",
541 pcol->inode->i_ino, pcol->pg_first, _LLU(ios->offset),
542 pcol->length);
543 /* pages ownership was passed to pcol_copy */
544 _pcol_reset(pcol);
545 return 0;
546
547 err:
548 _unlock_pcol_pages(pcol, ret, WRITE);
549 pcol_free(pcol);
550 kfree(pcol_copy);
551
552 return ret;
553 }
554
555 /* writepage_strip is called either directly from writepage() or by the VFS from
556 * within write_cache_pages(), to add one more page to be written to storage.
557 * It will try to collect as many contiguous pages as possible. If a
558 * discontinuity is encountered or it runs out of resources it will submit the
559 * previous segment and will start a new collection.
560 * Eventually caller must submit the last segment if present.
561 */
562 static int writepage_strip(struct page *page,
563 struct writeback_control *wbc_unused, void *data)
564 {
565 struct page_collect *pcol = data;
566 struct inode *inode = pcol->inode;
567 struct exofs_i_info *oi = exofs_i(inode);
568 loff_t i_size = i_size_read(inode);
569 pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
570 size_t len;
571 int ret;
572
573 BUG_ON(!PageLocked(page));
574
575 ret = wait_obj_created(oi);
576 if (unlikely(ret))
577 goto fail;
578
579 if (page->index < end_index)
580 /* in this case, the page is within the limits of the file */
581 len = PAGE_CACHE_SIZE;
582 else {
583 len = i_size & ~PAGE_CACHE_MASK;
584
585 if (page->index > end_index || !len) {
586 /* in this case, the page is outside the limits
587 * (truncate in progress)
588 */
589 ret = write_exec(pcol);
590 if (unlikely(ret))
591 goto fail;
592 if (PageError(page))
593 ClearPageError(page);
594 unlock_page(page);
595 EXOFS_DBGMSG("writepage_strip(0x%lx, 0x%lx) "
596 "outside the limits\n",
597 inode->i_ino, page->index);
598 return 0;
599 }
600 }
601
602 try_again:
603
604 if (unlikely(pcol->pg_first == -1)) {
605 pcol->pg_first = page->index;
606 } else if (unlikely((pcol->pg_first + pcol->nr_pages) !=
607 page->index)) {
608 /* Discontinuity detected, split the request */
609 ret = write_exec(pcol);
610 if (unlikely(ret))
611 goto fail;
612
613 EXOFS_DBGMSG("writepage_strip(0x%lx, 0x%lx) Discontinuity\n",
614 inode->i_ino, page->index);
615 goto try_again;
616 }
617
618 if (!pcol->pages) {
619 ret = pcol_try_alloc(pcol);
620 if (unlikely(ret))
621 goto fail;
622 }
623
624 EXOFS_DBGMSG2(" writepage_strip(0x%lx, 0x%lx) len=0x%zx\n",
625 inode->i_ino, page->index, len);
626
627 ret = pcol_add_page(pcol, page, len);
628 if (unlikely(ret)) {
629 EXOFS_DBGMSG2("Failed pcol_add_page "
630 "nr_pages=%u total_length=0x%lx\n",
631 pcol->nr_pages, pcol->length);
632
633 /* split the request, next loop will start again */
634 ret = write_exec(pcol);
635 if (unlikely(ret)) {
636 EXOFS_DBGMSG("write_exec failed => %d", ret);
637 goto fail;
638 }
639
640 goto try_again;
641 }
642
643 BUG_ON(PageWriteback(page));
644 set_page_writeback(page);
645
646 return 0;
647
648 fail:
649 EXOFS_DBGMSG("Error: writepage_strip(0x%lx, 0x%lx)=>%d\n",
650 inode->i_ino, page->index, ret);
651 set_bit(AS_EIO, &page->mapping->flags);
652 unlock_page(page);
653 return ret;
654 }
655
656 static int exofs_writepages(struct address_space *mapping,
657 struct writeback_control *wbc)
658 {
659 struct page_collect pcol;
660 long start, end, expected_pages;
661 int ret;
662
663 start = wbc->range_start >> PAGE_CACHE_SHIFT;
664 end = (wbc->range_end == LLONG_MAX) ?
665 start + mapping->nrpages :
666 wbc->range_end >> PAGE_CACHE_SHIFT;
667
668 if (start || end)
669 expected_pages = end - start + 1;
670 else
671 expected_pages = mapping->nrpages;
672
673 if (expected_pages < 32L)
674 expected_pages = 32L;
675
676 EXOFS_DBGMSG2("inode(0x%lx) wbc->start=0x%llx wbc->end=0x%llx "
677 "nrpages=%lu start=0x%lx end=0x%lx expected_pages=%ld\n",
678 mapping->host->i_ino, wbc->range_start, wbc->range_end,
679 mapping->nrpages, start, end, expected_pages);
680
681 _pcol_init(&pcol, expected_pages, mapping->host);
682
683 ret = write_cache_pages(mapping, wbc, writepage_strip, &pcol);
684 if (ret) {
685 EXOFS_ERR("write_cache_pages => %d\n", ret);
686 return ret;
687 }
688
689 return write_exec(&pcol);
690 }
691
692 static int exofs_writepage(struct page *page, struct writeback_control *wbc)
693 {
694 struct page_collect pcol;
695 int ret;
696
697 _pcol_init(&pcol, 1, page->mapping->host);
698
699 ret = writepage_strip(page, NULL, &pcol);
700 if (ret) {
701 EXOFS_ERR("exofs_writepage => %d\n", ret);
702 return ret;
703 }
704
705 return write_exec(&pcol);
706 }
707
708 /* i_mutex held using inode->i_size directly */
709 static void _write_failed(struct inode *inode, loff_t to)
710 {
711 if (to > inode->i_size)
712 truncate_pagecache(inode, to, inode->i_size);
713 }
714
715 int exofs_write_begin(struct file *file, struct address_space *mapping,
716 loff_t pos, unsigned len, unsigned flags,
717 struct page **pagep, void **fsdata)
718 {
719 int ret = 0;
720 struct page *page;
721
722 page = *pagep;
723 if (page == NULL) {
724 ret = simple_write_begin(file, mapping, pos, len, flags, pagep,
725 fsdata);
726 if (ret) {
727 EXOFS_DBGMSG("simple_write_begin failed\n");
728 goto out;
729 }
730
731 page = *pagep;
732 }
733
734 /* read modify write */
735 if (!PageUptodate(page) && (len != PAGE_CACHE_SIZE)) {
736 loff_t i_size = i_size_read(mapping->host);
737 pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
738 size_t rlen;
739
740 if (page->index < end_index)
741 rlen = PAGE_CACHE_SIZE;
742 else if (page->index == end_index)
743 rlen = i_size & ~PAGE_CACHE_MASK;
744 else
745 rlen = 0;
746
747 if (!rlen) {
748 clear_highpage(page);
749 SetPageUptodate(page);
750 goto out;
751 }
752
753 ret = _readpage(page, true);
754 if (ret) {
755 /*SetPageError was done by _readpage. Is it ok?*/
756 unlock_page(page);
757 EXOFS_DBGMSG("__readpage failed\n");
758 }
759 }
760 out:
761 if (unlikely(ret))
762 _write_failed(mapping->host, pos + len);
763
764 return ret;
765 }
766
767 static int exofs_write_begin_export(struct file *file,
768 struct address_space *mapping,
769 loff_t pos, unsigned len, unsigned flags,
770 struct page **pagep, void **fsdata)
771 {
772 *pagep = NULL;
773
774 return exofs_write_begin(file, mapping, pos, len, flags, pagep,
775 fsdata);
776 }
777
778 static int exofs_write_end(struct file *file, struct address_space *mapping,
779 loff_t pos, unsigned len, unsigned copied,
780 struct page *page, void *fsdata)
781 {
782 struct inode *inode = mapping->host;
783 /* According to comment in simple_write_end i_mutex is held */
784 loff_t i_size = inode->i_size;
785 int ret;
786
787 ret = simple_write_end(file, mapping,pos, len, copied, page, fsdata);
788 if (unlikely(ret))
789 _write_failed(inode, pos + len);
790
791 /* TODO: once simple_write_end marks inode dirty remove */
792 if (i_size != inode->i_size)
793 mark_inode_dirty(inode);
794 return ret;
795 }
796
797 static int exofs_releasepage(struct page *page, gfp_t gfp)
798 {
799 EXOFS_DBGMSG("page 0x%lx\n", page->index);
800 WARN_ON(1);
801 return 0;
802 }
803
804 static void exofs_invalidatepage(struct page *page, unsigned long offset)
805 {
806 EXOFS_DBGMSG("page 0x%lx offset 0x%lx\n", page->index, offset);
807 WARN_ON(1);
808 }
809
810 const struct address_space_operations exofs_aops = {
811 .readpage = exofs_readpage,
812 .readpages = exofs_readpages,
813 .writepage = exofs_writepage,
814 .writepages = exofs_writepages,
815 .write_begin = exofs_write_begin_export,
816 .write_end = exofs_write_end,
817 .releasepage = exofs_releasepage,
818 .set_page_dirty = __set_page_dirty_nobuffers,
819 .invalidatepage = exofs_invalidatepage,
820
821 /* Not implemented Yet */
822 .bmap = NULL, /* TODO: use osd's OSD_ACT_READ_MAP */
823 .direct_IO = NULL, /* TODO: Should be trivial to do */
824
825 /* With these NULL has special meaning or default is not exported */
826 .get_xip_mem = NULL,
827 .migratepage = NULL,
828 .launder_page = NULL,
829 .is_partially_uptodate = NULL,
830 .error_remove_page = NULL,
831 };
832
833 /******************************************************************************
834 * INODE OPERATIONS
835 *****************************************************************************/
836
837 /*
838 * Test whether an inode is a fast symlink.
839 */
840 static inline int exofs_inode_is_fast_symlink(struct inode *inode)
841 {
842 struct exofs_i_info *oi = exofs_i(inode);
843
844 return S_ISLNK(inode->i_mode) && (oi->i_data[0] != 0);
845 }
846
847 const struct osd_attr g_attr_logical_length = ATTR_DEF(
848 OSD_APAGE_OBJECT_INFORMATION, OSD_ATTR_OI_LOGICAL_LENGTH, 8);
849
850 static int _do_truncate(struct inode *inode, loff_t newsize)
851 {
852 struct exofs_i_info *oi = exofs_i(inode);
853 int ret;
854
855 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
856
857 ret = exofs_oi_truncate(oi, (u64)newsize);
858 if (likely(!ret))
859 truncate_setsize(inode, newsize);
860
861 EXOFS_DBGMSG("(0x%lx) size=0x%llx ret=>%d\n",
862 inode->i_ino, newsize, ret);
863 return ret;
864 }
865
866 /*
867 * Set inode attributes - update size attribute on OSD if needed,
868 * otherwise just call generic functions.
869 */
870 int exofs_setattr(struct dentry *dentry, struct iattr *iattr)
871 {
872 struct inode *inode = dentry->d_inode;
873 int error;
874
875 /* if we are about to modify an object, and it hasn't been
876 * created yet, wait
877 */
878 error = wait_obj_created(exofs_i(inode));
879 if (unlikely(error))
880 return error;
881
882 error = inode_change_ok(inode, iattr);
883 if (unlikely(error))
884 return error;
885
886 if ((iattr->ia_valid & ATTR_SIZE) &&
887 iattr->ia_size != i_size_read(inode)) {
888 error = _do_truncate(inode, iattr->ia_size);
889 if (unlikely(error))
890 return error;
891 }
892
893 setattr_copy(inode, iattr);
894 mark_inode_dirty(inode);
895 return 0;
896 }
897
898 static const struct osd_attr g_attr_inode_file_layout = ATTR_DEF(
899 EXOFS_APAGE_FS_DATA,
900 EXOFS_ATTR_INODE_FILE_LAYOUT,
901 0);
902 static const struct osd_attr g_attr_inode_dir_layout = ATTR_DEF(
903 EXOFS_APAGE_FS_DATA,
904 EXOFS_ATTR_INODE_DIR_LAYOUT,
905 0);
906
907 /*
908 * Read the Linux inode info from the OSD, and return it as is. In exofs the
909 * inode info is in an application specific page/attribute of the osd-object.
910 */
911 static int exofs_get_inode(struct super_block *sb, struct exofs_i_info *oi,
912 struct exofs_fcb *inode)
913 {
914 struct exofs_sb_info *sbi = sb->s_fs_info;
915 struct osd_attr attrs[] = {
916 [0] = g_attr_inode_data,
917 [1] = g_attr_inode_file_layout,
918 [2] = g_attr_inode_dir_layout,
919 };
920 struct exofs_io_state *ios;
921 struct exofs_on_disk_inode_layout *layout;
922 int ret;
923
924 ret = exofs_get_io_state(&sbi->layout, &ios);
925 if (unlikely(ret)) {
926 EXOFS_ERR("%s: exofs_get_io_state failed.\n", __func__);
927 return ret;
928 }
929
930 ios->obj.id = exofs_oi_objno(oi);
931 exofs_make_credential(oi->i_cred, &ios->obj);
932 ios->cred = oi->i_cred;
933
934 attrs[1].len = exofs_on_disk_inode_layout_size(sbi->layout.s_numdevs);
935 attrs[2].len = exofs_on_disk_inode_layout_size(sbi->layout.s_numdevs);
936
937 ios->in_attr = attrs;
938 ios->in_attr_len = ARRAY_SIZE(attrs);
939
940 ret = exofs_sbi_read(ios);
941 if (unlikely(ret)) {
942 EXOFS_ERR("object(0x%llx) corrupted, return empty file=>%d\n",
943 _LLU(ios->obj.id), ret);
944 memset(inode, 0, sizeof(*inode));
945 inode->i_mode = 0040000 | (0777 & ~022);
946 /* If object is lost on target we might as well enable it's
947 * delete.
948 */
949 if ((ret == -ENOENT) || (ret == -EINVAL))
950 ret = 0;
951 goto out;
952 }
953
954 ret = extract_attr_from_ios(ios, &attrs[0]);
955 if (ret) {
956 EXOFS_ERR("%s: extract_attr of inode_data failed\n", __func__);
957 goto out;
958 }
959 WARN_ON(attrs[0].len != EXOFS_INO_ATTR_SIZE);
960 memcpy(inode, attrs[0].val_ptr, EXOFS_INO_ATTR_SIZE);
961
962 ret = extract_attr_from_ios(ios, &attrs[1]);
963 if (ret) {
964 EXOFS_ERR("%s: extract_attr of inode_data failed\n", __func__);
965 goto out;
966 }
967 if (attrs[1].len) {
968 layout = attrs[1].val_ptr;
969 if (layout->gen_func != cpu_to_le16(LAYOUT_MOVING_WINDOW)) {
970 EXOFS_ERR("%s: unsupported files layout %d\n",
971 __func__, layout->gen_func);
972 ret = -ENOTSUPP;
973 goto out;
974 }
975 }
976
977 ret = extract_attr_from_ios(ios, &attrs[2]);
978 if (ret) {
979 EXOFS_ERR("%s: extract_attr of inode_data failed\n", __func__);
980 goto out;
981 }
982 if (attrs[2].len) {
983 layout = attrs[2].val_ptr;
984 if (layout->gen_func != cpu_to_le16(LAYOUT_MOVING_WINDOW)) {
985 EXOFS_ERR("%s: unsupported meta-data layout %d\n",
986 __func__, layout->gen_func);
987 ret = -ENOTSUPP;
988 goto out;
989 }
990 }
991
992 out:
993 exofs_put_io_state(ios);
994 return ret;
995 }
996
997 static void __oi_init(struct exofs_i_info *oi)
998 {
999 init_waitqueue_head(&oi->i_wq);
1000 oi->i_flags = 0;
1001 }
1002 /*
1003 * Fill in an inode read from the OSD and set it up for use
1004 */
1005 struct inode *exofs_iget(struct super_block *sb, unsigned long ino)
1006 {
1007 struct exofs_i_info *oi;
1008 struct exofs_fcb fcb;
1009 struct inode *inode;
1010 int ret;
1011
1012 inode = iget_locked(sb, ino);
1013 if (!inode)
1014 return ERR_PTR(-ENOMEM);
1015 if (!(inode->i_state & I_NEW))
1016 return inode;
1017 oi = exofs_i(inode);
1018 __oi_init(oi);
1019
1020 /* read the inode from the osd */
1021 ret = exofs_get_inode(sb, oi, &fcb);
1022 if (ret)
1023 goto bad_inode;
1024
1025 set_obj_created(oi);
1026
1027 /* copy stuff from on-disk struct to in-memory struct */
1028 inode->i_mode = le16_to_cpu(fcb.i_mode);
1029 inode->i_uid = le32_to_cpu(fcb.i_uid);
1030 inode->i_gid = le32_to_cpu(fcb.i_gid);
1031 inode->i_nlink = le16_to_cpu(fcb.i_links_count);
1032 inode->i_ctime.tv_sec = (signed)le32_to_cpu(fcb.i_ctime);
1033 inode->i_atime.tv_sec = (signed)le32_to_cpu(fcb.i_atime);
1034 inode->i_mtime.tv_sec = (signed)le32_to_cpu(fcb.i_mtime);
1035 inode->i_ctime.tv_nsec =
1036 inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = 0;
1037 oi->i_commit_size = le64_to_cpu(fcb.i_size);
1038 i_size_write(inode, oi->i_commit_size);
1039 inode->i_blkbits = EXOFS_BLKSHIFT;
1040 inode->i_generation = le32_to_cpu(fcb.i_generation);
1041
1042 oi->i_dir_start_lookup = 0;
1043
1044 if ((inode->i_nlink == 0) && (inode->i_mode == 0)) {
1045 ret = -ESTALE;
1046 goto bad_inode;
1047 }
1048
1049 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
1050 if (fcb.i_data[0])
1051 inode->i_rdev =
1052 old_decode_dev(le32_to_cpu(fcb.i_data[0]));
1053 else
1054 inode->i_rdev =
1055 new_decode_dev(le32_to_cpu(fcb.i_data[1]));
1056 } else {
1057 memcpy(oi->i_data, fcb.i_data, sizeof(fcb.i_data));
1058 }
1059
1060 inode->i_mapping->backing_dev_info = sb->s_bdi;
1061 if (S_ISREG(inode->i_mode)) {
1062 inode->i_op = &exofs_file_inode_operations;
1063 inode->i_fop = &exofs_file_operations;
1064 inode->i_mapping->a_ops = &exofs_aops;
1065 } else if (S_ISDIR(inode->i_mode)) {
1066 inode->i_op = &exofs_dir_inode_operations;
1067 inode->i_fop = &exofs_dir_operations;
1068 inode->i_mapping->a_ops = &exofs_aops;
1069 } else if (S_ISLNK(inode->i_mode)) {
1070 if (exofs_inode_is_fast_symlink(inode))
1071 inode->i_op = &exofs_fast_symlink_inode_operations;
1072 else {
1073 inode->i_op = &exofs_symlink_inode_operations;
1074 inode->i_mapping->a_ops = &exofs_aops;
1075 }
1076 } else {
1077 inode->i_op = &exofs_special_inode_operations;
1078 if (fcb.i_data[0])
1079 init_special_inode(inode, inode->i_mode,
1080 old_decode_dev(le32_to_cpu(fcb.i_data[0])));
1081 else
1082 init_special_inode(inode, inode->i_mode,
1083 new_decode_dev(le32_to_cpu(fcb.i_data[1])));
1084 }
1085
1086 unlock_new_inode(inode);
1087 return inode;
1088
1089 bad_inode:
1090 iget_failed(inode);
1091 return ERR_PTR(ret);
1092 }
1093
1094 int __exofs_wait_obj_created(struct exofs_i_info *oi)
1095 {
1096 if (!obj_created(oi)) {
1097 EXOFS_DBGMSG("!obj_created\n");
1098 BUG_ON(!obj_2bcreated(oi));
1099 wait_event(oi->i_wq, obj_created(oi));
1100 EXOFS_DBGMSG("wait_event done\n");
1101 }
1102 return unlikely(is_bad_inode(&oi->vfs_inode)) ? -EIO : 0;
1103 }
1104
1105 /*
1106 * Callback function from exofs_new_inode(). The important thing is that we
1107 * set the obj_created flag so that other methods know that the object exists on
1108 * the OSD.
1109 */
1110 static void create_done(struct exofs_io_state *ios, void *p)
1111 {
1112 struct inode *inode = p;
1113 struct exofs_i_info *oi = exofs_i(inode);
1114 struct exofs_sb_info *sbi = inode->i_sb->s_fs_info;
1115 int ret;
1116
1117 ret = exofs_check_io(ios, NULL);
1118 exofs_put_io_state(ios);
1119
1120 atomic_dec(&sbi->s_curr_pending);
1121
1122 if (unlikely(ret)) {
1123 EXOFS_ERR("object=0x%llx creation failed in pid=0x%llx",
1124 _LLU(exofs_oi_objno(oi)), _LLU(sbi->layout.s_pid));
1125 /*TODO: When FS is corrupted creation can fail, object already
1126 * exist. Get rid of this asynchronous creation, if exist
1127 * increment the obj counter and try the next object. Until we
1128 * succeed. All these dangling objects will be made into lost
1129 * files by chkfs.exofs
1130 */
1131 }
1132
1133 set_obj_created(oi);
1134
1135 wake_up(&oi->i_wq);
1136 }
1137
1138 /*
1139 * Set up a new inode and create an object for it on the OSD
1140 */
1141 struct inode *exofs_new_inode(struct inode *dir, int mode)
1142 {
1143 struct super_block *sb;
1144 struct inode *inode;
1145 struct exofs_i_info *oi;
1146 struct exofs_sb_info *sbi;
1147 struct exofs_io_state *ios;
1148 int ret;
1149
1150 sb = dir->i_sb;
1151 inode = new_inode(sb);
1152 if (!inode)
1153 return ERR_PTR(-ENOMEM);
1154
1155 oi = exofs_i(inode);
1156 __oi_init(oi);
1157
1158 set_obj_2bcreated(oi);
1159
1160 sbi = sb->s_fs_info;
1161
1162 inode->i_mapping->backing_dev_info = sb->s_bdi;
1163 inode_init_owner(inode, dir, mode);
1164 inode->i_ino = sbi->s_nextid++;
1165 inode->i_blkbits = EXOFS_BLKSHIFT;
1166 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1167 oi->i_commit_size = inode->i_size = 0;
1168 spin_lock(&sbi->s_next_gen_lock);
1169 inode->i_generation = sbi->s_next_generation++;
1170 spin_unlock(&sbi->s_next_gen_lock);
1171 insert_inode_hash(inode);
1172
1173 exofs_sbi_write_stats(sbi); /* Make sure new sbi->s_nextid is on disk */
1174
1175 mark_inode_dirty(inode);
1176
1177 ret = exofs_get_io_state(&sbi->layout, &ios);
1178 if (unlikely(ret)) {
1179 EXOFS_ERR("exofs_new_inode: exofs_get_io_state failed\n");
1180 return ERR_PTR(ret);
1181 }
1182
1183 ios->obj.id = exofs_oi_objno(oi);
1184 exofs_make_credential(oi->i_cred, &ios->obj);
1185
1186 ios->done = create_done;
1187 ios->private = inode;
1188 ios->cred = oi->i_cred;
1189 ret = exofs_sbi_create(ios);
1190 if (ret) {
1191 exofs_put_io_state(ios);
1192 return ERR_PTR(ret);
1193 }
1194 atomic_inc(&sbi->s_curr_pending);
1195
1196 return inode;
1197 }
1198
1199 /*
1200 * struct to pass two arguments to update_inode's callback
1201 */
1202 struct updatei_args {
1203 struct exofs_sb_info *sbi;
1204 struct exofs_fcb fcb;
1205 };
1206
1207 /*
1208 * Callback function from exofs_update_inode().
1209 */
1210 static void updatei_done(struct exofs_io_state *ios, void *p)
1211 {
1212 struct updatei_args *args = p;
1213
1214 exofs_put_io_state(ios);
1215
1216 atomic_dec(&args->sbi->s_curr_pending);
1217
1218 kfree(args);
1219 }
1220
1221 /*
1222 * Write the inode to the OSD. Just fill up the struct, and set the attribute
1223 * synchronously or asynchronously depending on the do_sync flag.
1224 */
1225 static int exofs_update_inode(struct inode *inode, int do_sync)
1226 {
1227 struct exofs_i_info *oi = exofs_i(inode);
1228 struct super_block *sb = inode->i_sb;
1229 struct exofs_sb_info *sbi = sb->s_fs_info;
1230 struct exofs_io_state *ios;
1231 struct osd_attr attr;
1232 struct exofs_fcb *fcb;
1233 struct updatei_args *args;
1234 int ret;
1235
1236 args = kzalloc(sizeof(*args), GFP_KERNEL);
1237 if (!args) {
1238 EXOFS_DBGMSG("Failed kzalloc of args\n");
1239 return -ENOMEM;
1240 }
1241
1242 fcb = &args->fcb;
1243
1244 fcb->i_mode = cpu_to_le16(inode->i_mode);
1245 fcb->i_uid = cpu_to_le32(inode->i_uid);
1246 fcb->i_gid = cpu_to_le32(inode->i_gid);
1247 fcb->i_links_count = cpu_to_le16(inode->i_nlink);
1248 fcb->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
1249 fcb->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
1250 fcb->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
1251 oi->i_commit_size = i_size_read(inode);
1252 fcb->i_size = cpu_to_le64(oi->i_commit_size);
1253 fcb->i_generation = cpu_to_le32(inode->i_generation);
1254
1255 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
1256 if (old_valid_dev(inode->i_rdev)) {
1257 fcb->i_data[0] =
1258 cpu_to_le32(old_encode_dev(inode->i_rdev));
1259 fcb->i_data[1] = 0;
1260 } else {
1261 fcb->i_data[0] = 0;
1262 fcb->i_data[1] =
1263 cpu_to_le32(new_encode_dev(inode->i_rdev));
1264 fcb->i_data[2] = 0;
1265 }
1266 } else
1267 memcpy(fcb->i_data, oi->i_data, sizeof(fcb->i_data));
1268
1269 ret = exofs_get_io_state(&sbi->layout, &ios);
1270 if (unlikely(ret)) {
1271 EXOFS_ERR("%s: exofs_get_io_state failed.\n", __func__);
1272 goto free_args;
1273 }
1274
1275 attr = g_attr_inode_data;
1276 attr.val_ptr = fcb;
1277 ios->out_attr_len = 1;
1278 ios->out_attr = &attr;
1279
1280 wait_obj_created(oi);
1281
1282 if (!do_sync) {
1283 args->sbi = sbi;
1284 ios->done = updatei_done;
1285 ios->private = args;
1286 }
1287
1288 ret = exofs_oi_write(oi, ios);
1289 if (!do_sync && !ret) {
1290 atomic_inc(&sbi->s_curr_pending);
1291 goto out; /* deallocation in updatei_done */
1292 }
1293
1294 exofs_put_io_state(ios);
1295 free_args:
1296 kfree(args);
1297 out:
1298 EXOFS_DBGMSG("(0x%lx) do_sync=%d ret=>%d\n",
1299 inode->i_ino, do_sync, ret);
1300 return ret;
1301 }
1302
1303 int exofs_write_inode(struct inode *inode, struct writeback_control *wbc)
1304 {
1305 /* FIXME: fix fsync and use wbc->sync_mode == WB_SYNC_ALL */
1306 return exofs_update_inode(inode, 1);
1307 }
1308
1309 /*
1310 * Callback function from exofs_delete_inode() - don't have much cleaning up to
1311 * do.
1312 */
1313 static void delete_done(struct exofs_io_state *ios, void *p)
1314 {
1315 struct exofs_sb_info *sbi = p;
1316
1317 exofs_put_io_state(ios);
1318
1319 atomic_dec(&sbi->s_curr_pending);
1320 }
1321
1322 /*
1323 * Called when the refcount of an inode reaches zero. We remove the object
1324 * from the OSD here. We make sure the object was created before we try and
1325 * delete it.
1326 */
1327 void exofs_evict_inode(struct inode *inode)
1328 {
1329 struct exofs_i_info *oi = exofs_i(inode);
1330 struct super_block *sb = inode->i_sb;
1331 struct exofs_sb_info *sbi = sb->s_fs_info;
1332 struct exofs_io_state *ios;
1333 int ret;
1334
1335 truncate_inode_pages(&inode->i_data, 0);
1336
1337 /* TODO: should do better here */
1338 if (inode->i_nlink || is_bad_inode(inode))
1339 goto no_delete;
1340
1341 inode->i_size = 0;
1342 end_writeback(inode);
1343
1344 /* if we are deleting an obj that hasn't been created yet, wait.
1345 * This also makes sure that create_done cannot be called with an
1346 * already evicted inode.
1347 */
1348 wait_obj_created(oi);
1349 /* ignore the error, attempt a remove anyway */
1350
1351 /* Now Remove the OSD objects */
1352 ret = exofs_get_io_state(&sbi->layout, &ios);
1353 if (unlikely(ret)) {
1354 EXOFS_ERR("%s: exofs_get_io_state failed\n", __func__);
1355 return;
1356 }
1357
1358 ios->obj.id = exofs_oi_objno(oi);
1359 ios->done = delete_done;
1360 ios->private = sbi;
1361 ios->cred = oi->i_cred;
1362 ret = exofs_sbi_remove(ios);
1363 if (ret) {
1364 EXOFS_ERR("%s: exofs_sbi_remove failed\n", __func__);
1365 exofs_put_io_state(ios);
1366 return;
1367 }
1368 atomic_inc(&sbi->s_curr_pending);
1369
1370 return;
1371
1372 no_delete:
1373 end_writeback(inode);
1374 }
Linux kernel - Deliverables
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