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Merge branch 'v6v7' into devel
[linux/fpc-iii.git] / fs / exofs / inode.c
bloba7555238c41aaf942237b2aafb780c8605244812
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 struct page_collect {
47 struct exofs_sb_info *sbi;
48 struct inode *inode;
49 unsigned expected_pages;
50 struct exofs_io_state *ios;
51
52 struct page **pages;
53 unsigned alloc_pages;
54 unsigned nr_pages;
55 unsigned long length;
56 loff_t pg_first; /* keep 64bit also in 32-arches */
57 bool read_4_write; /* This means two things: that the read is sync
58 * And the pages should not be unlocked.
59 */
60 };
61
62 static void _pcol_init(struct page_collect *pcol, unsigned expected_pages,
63 struct inode *inode)
64 {
65 struct exofs_sb_info *sbi = inode->i_sb->s_fs_info;
66
67 pcol->sbi = sbi;
68 pcol->inode = inode;
69 pcol->expected_pages = expected_pages;
70
71 pcol->ios = NULL;
72 pcol->pages = NULL;
73 pcol->alloc_pages = 0;
74 pcol->nr_pages = 0;
75 pcol->length = 0;
76 pcol->pg_first = -1;
77 pcol->read_4_write = false;
78 }
79
80 static void _pcol_reset(struct page_collect *pcol)
81 {
82 pcol->expected_pages -= min(pcol->nr_pages, pcol->expected_pages);
83
84 pcol->pages = NULL;
85 pcol->alloc_pages = 0;
86 pcol->nr_pages = 0;
87 pcol->length = 0;
88 pcol->pg_first = -1;
89 pcol->ios = NULL;
90
91 /* this is probably the end of the loop but in writes
92 * it might not end here. don't be left with nothing
93 */
94 if (!pcol->expected_pages)
95 pcol->expected_pages = MAX_PAGES_KMALLOC;
96 }
97
98 static int pcol_try_alloc(struct page_collect *pcol)
99 {
100 unsigned pages = min_t(unsigned, pcol->expected_pages,
101 MAX_PAGES_KMALLOC);
102
103 if (!pcol->ios) { /* First time allocate io_state */
104 int ret = exofs_get_io_state(&pcol->sbi->layout, &pcol->ios);
105
106 if (ret)
107 return ret;
108 }
109
110 /* TODO: easily support bio chaining */
111 pages = min_t(unsigned, pages,
112 pcol->sbi->layout.group_width * BIO_MAX_PAGES_KMALLOC);
113
114 for (; pages; pages >>= 1) {
115 pcol->pages = kmalloc(pages * sizeof(struct page *),
116 GFP_KERNEL);
117 if (likely(pcol->pages)) {
118 pcol->alloc_pages = pages;
119 return 0;
120 }
121 }
122
123 EXOFS_ERR("Failed to kmalloc expected_pages=%u\n",
124 pcol->expected_pages);
125 return -ENOMEM;
126 }
127
128 static void pcol_free(struct page_collect *pcol)
129 {
130 kfree(pcol->pages);
131 pcol->pages = NULL;
132
133 if (pcol->ios) {
134 exofs_put_io_state(pcol->ios);
135 pcol->ios = NULL;
136 }
137 }
138
139 static int pcol_add_page(struct page_collect *pcol, struct page *page,
140 unsigned len)
141 {
142 if (unlikely(pcol->nr_pages >= pcol->alloc_pages))
143 return -ENOMEM;
144
145 pcol->pages[pcol->nr_pages++] = page;
146 pcol->length += len;
147 return 0;
148 }
149
150 static int update_read_page(struct page *page, int ret)
151 {
152 if (ret == 0) {
153 /* Everything is OK */
154 SetPageUptodate(page);
155 if (PageError(page))
156 ClearPageError(page);
157 } else if (ret == -EFAULT) {
158 /* In this case we were trying to read something that wasn't on
159 * disk yet - return a page full of zeroes. This should be OK,
160 * because the object should be empty (if there was a write
161 * before this read, the read would be waiting with the page
162 * locked */
163 clear_highpage(page);
164
165 SetPageUptodate(page);
166 if (PageError(page))
167 ClearPageError(page);
168 ret = 0; /* recovered error */
169 EXOFS_DBGMSG("recovered read error\n");
170 } else /* Error */
171 SetPageError(page);
172
173 return ret;
174 }
175
176 static void update_write_page(struct page *page, int ret)
177 {
178 if (ret) {
179 mapping_set_error(page->mapping, ret);
180 SetPageError(page);
181 }
182 end_page_writeback(page);
183 }
184
185 /* Called at the end of reads, to optionally unlock pages and update their
186 * status.
187 */
188 static int __readpages_done(struct page_collect *pcol)
189 {
190 int i;
191 u64 resid;
192 u64 good_bytes;
193 u64 length = 0;
194 int ret = exofs_check_io(pcol->ios, &resid);
195
196 if (likely(!ret))
197 good_bytes = pcol->length;
198 else
199 good_bytes = pcol->length - resid;
200
201 EXOFS_DBGMSG2("readpages_done(0x%lx) good_bytes=0x%llx"
202 " length=0x%lx nr_pages=%u\n",
203 pcol->inode->i_ino, _LLU(good_bytes), pcol->length,
204 pcol->nr_pages);
205
206 for (i = 0; i < pcol->nr_pages; i++) {
207 struct page *page = pcol->pages[i];
208 struct inode *inode = page->mapping->host;
209 int page_stat;
210
211 if (inode != pcol->inode)
212 continue; /* osd might add more pages at end */
213
214 if (likely(length < good_bytes))
215 page_stat = 0;
216 else
217 page_stat = ret;
218
219 EXOFS_DBGMSG2(" readpages_done(0x%lx, 0x%lx) %s\n",
220 inode->i_ino, page->index,
221 page_stat ? "bad_bytes" : "good_bytes");
222
223 ret = update_read_page(page, page_stat);
224 if (!pcol->read_4_write)
225 unlock_page(page);
226 length += PAGE_SIZE;
227 }
228
229 pcol_free(pcol);
230 EXOFS_DBGMSG2("readpages_done END\n");
231 return ret;
232 }
233
234 /* callback of async reads */
235 static void readpages_done(struct exofs_io_state *ios, void *p)
236 {
237 struct page_collect *pcol = p;
238
239 __readpages_done(pcol);
240 atomic_dec(&pcol->sbi->s_curr_pending);
241 kfree(pcol);
242 }
243
244 static void _unlock_pcol_pages(struct page_collect *pcol, int ret, int rw)
245 {
246 int i;
247
248 for (i = 0; i < pcol->nr_pages; i++) {
249 struct page *page = pcol->pages[i];
250
251 if (rw == READ)
252 update_read_page(page, ret);
253 else
254 update_write_page(page, ret);
255
256 unlock_page(page);
257 }
258 }
259
260 static int read_exec(struct page_collect *pcol)
261 {
262 struct exofs_i_info *oi = exofs_i(pcol->inode);
263 struct exofs_io_state *ios = pcol->ios;
264 struct page_collect *pcol_copy = NULL;
265 int ret;
266
267 if (!pcol->pages)
268 return 0;
269
270 ios->pages = pcol->pages;
271 ios->nr_pages = pcol->nr_pages;
272 ios->length = pcol->length;
273 ios->offset = pcol->pg_first << PAGE_CACHE_SHIFT;
274
275 if (pcol->read_4_write) {
276 exofs_oi_read(oi, pcol->ios);
277 return __readpages_done(pcol);
278 }
279
280 pcol_copy = kmalloc(sizeof(*pcol_copy), GFP_KERNEL);
281 if (!pcol_copy) {
282 ret = -ENOMEM;
283 goto err;
284 }
285
286 *pcol_copy = *pcol;
287 ios->done = readpages_done;
288 ios->private = pcol_copy;
289 ret = exofs_oi_read(oi, ios);
290 if (unlikely(ret))
291 goto err;
292
293 atomic_inc(&pcol->sbi->s_curr_pending);
294
295 EXOFS_DBGMSG2("read_exec obj=0x%llx start=0x%llx length=0x%lx\n",
296 ios->obj.id, _LLU(ios->offset), pcol->length);
297
298 /* pages ownership was passed to pcol_copy */
299 _pcol_reset(pcol);
300 return 0;
301
302 err:
303 if (!pcol->read_4_write)
304 _unlock_pcol_pages(pcol, ret, READ);
305
306 pcol_free(pcol);
307
308 kfree(pcol_copy);
309 return ret;
310 }
311
312 /* readpage_strip is called either directly from readpage() or by the VFS from
313 * within read_cache_pages(), to add one more page to be read. It will try to
314 * collect as many contiguous pages as posible. If a discontinuity is
315 * encountered, or it runs out of resources, it will submit the previous segment
316 * and will start a new collection. Eventually caller must submit the last
317 * segment if present.
318 */
319 static int readpage_strip(void *data, struct page *page)
320 {
321 struct page_collect *pcol = data;
322 struct inode *inode = pcol->inode;
323 struct exofs_i_info *oi = exofs_i(inode);
324 loff_t i_size = i_size_read(inode);
325 pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
326 size_t len;
327 int ret;
328
329 /* FIXME: Just for debugging, will be removed */
330 if (PageUptodate(page))
331 EXOFS_ERR("PageUptodate(0x%lx, 0x%lx)\n", pcol->inode->i_ino,
332 page->index);
333
334 if (page->index < end_index)
335 len = PAGE_CACHE_SIZE;
336 else if (page->index == end_index)
337 len = i_size & ~PAGE_CACHE_MASK;
338 else
339 len = 0;
340
341 if (!len || !obj_created(oi)) {
342 /* this will be out of bounds, or doesn't exist yet.
343 * Current page is cleared and the request is split
344 */
345 clear_highpage(page);
346
347 SetPageUptodate(page);
348 if (PageError(page))
349 ClearPageError(page);
350
351 if (!pcol->read_4_write)
352 unlock_page(page);
353 EXOFS_DBGMSG("readpage_strip(0x%lx, 0x%lx) empty page,"
354 " splitting\n", inode->i_ino, page->index);
355
356 return read_exec(pcol);
357 }
358
359 try_again:
360
361 if (unlikely(pcol->pg_first == -1)) {
362 pcol->pg_first = page->index;
363 } else if (unlikely((pcol->pg_first + pcol->nr_pages) !=
364 page->index)) {
365 /* Discontinuity detected, split the request */
366 ret = read_exec(pcol);
367 if (unlikely(ret))
368 goto fail;
369 goto try_again;
370 }
371
372 if (!pcol->pages) {
373 ret = pcol_try_alloc(pcol);
374 if (unlikely(ret))
375 goto fail;
376 }
377
378 if (len != PAGE_CACHE_SIZE)
379 zero_user(page, len, PAGE_CACHE_SIZE - len);
380
381 EXOFS_DBGMSG2(" readpage_strip(0x%lx, 0x%lx) len=0x%zx\n",
382 inode->i_ino, page->index, len);
383
384 ret = pcol_add_page(pcol, page, len);
385 if (ret) {
386 EXOFS_DBGMSG2("Failed pcol_add_page pages[i]=%p "
387 "this_len=0x%zx nr_pages=%u length=0x%lx\n",
388 page, len, pcol->nr_pages, pcol->length);
389
390 /* split the request, and start again with current page */
391 ret = read_exec(pcol);
392 if (unlikely(ret))
393 goto fail;
394
395 goto try_again;
396 }
397
398 return 0;
399
400 fail:
401 /* SetPageError(page); ??? */
402 unlock_page(page);
403 return ret;
404 }
405
406 static int exofs_readpages(struct file *file, struct address_space *mapping,
407 struct list_head *pages, unsigned nr_pages)
408 {
409 struct page_collect pcol;
410 int ret;
411
412 _pcol_init(&pcol, nr_pages, mapping->host);
413
414 ret = read_cache_pages(mapping, pages, readpage_strip, &pcol);
415 if (ret) {
416 EXOFS_ERR("read_cache_pages => %d\n", ret);
417 return ret;
418 }
419
420 return read_exec(&pcol);
421 }
422
423 static int _readpage(struct page *page, bool read_4_write)
424 {
425 struct page_collect pcol;
426 int ret;
427
428 _pcol_init(&pcol, 1, page->mapping->host);
429
430 pcol.read_4_write = read_4_write;
431 ret = readpage_strip(&pcol, page);
432 if (ret) {
433 EXOFS_ERR("_readpage => %d\n", ret);
434 return ret;
435 }
436
437 return read_exec(&pcol);
438 }
439
440 /*
441 * We don't need the file
442 */
443 static int exofs_readpage(struct file *file, struct page *page)
444 {
445 return _readpage(page, false);
446 }
447
448 /* Callback for osd_write. All writes are asynchronous */
449 static void writepages_done(struct exofs_io_state *ios, void *p)
450 {
451 struct page_collect *pcol = p;
452 int i;
453 u64 resid;
454 u64 good_bytes;
455 u64 length = 0;
456 int ret = exofs_check_io(ios, &resid);
457
458 atomic_dec(&pcol->sbi->s_curr_pending);
459
460 if (likely(!ret))
461 good_bytes = pcol->length;
462 else
463 good_bytes = pcol->length - resid;
464
465 EXOFS_DBGMSG2("writepages_done(0x%lx) good_bytes=0x%llx"
466 " length=0x%lx nr_pages=%u\n",
467 pcol->inode->i_ino, _LLU(good_bytes), pcol->length,
468 pcol->nr_pages);
469
470 for (i = 0; i < pcol->nr_pages; i++) {
471 struct page *page = pcol->pages[i];
472 struct inode *inode = page->mapping->host;
473 int page_stat;
474
475 if (inode != pcol->inode)
476 continue; /* osd might add more pages to a bio */
477
478 if (likely(length < good_bytes))
479 page_stat = 0;
480 else
481 page_stat = ret;
482
483 update_write_page(page, page_stat);
484 unlock_page(page);
485 EXOFS_DBGMSG2(" writepages_done(0x%lx, 0x%lx) status=%d\n",
486 inode->i_ino, page->index, page_stat);
487
488 length += PAGE_SIZE;
489 }
490
491 pcol_free(pcol);
492 kfree(pcol);
493 EXOFS_DBGMSG2("writepages_done END\n");
494 }
495
496 static int write_exec(struct page_collect *pcol)
497 {
498 struct exofs_i_info *oi = exofs_i(pcol->inode);
499 struct exofs_io_state *ios = pcol->ios;
500 struct page_collect *pcol_copy = NULL;
501 int ret;
502
503 if (!pcol->pages)
504 return 0;
505
506 pcol_copy = kmalloc(sizeof(*pcol_copy), GFP_KERNEL);
507 if (!pcol_copy) {
508 EXOFS_ERR("write_exec: Failed to kmalloc(pcol)\n");
509 ret = -ENOMEM;
510 goto err;
511 }
512
513 *pcol_copy = *pcol;
514
515 ios->pages = pcol_copy->pages;
516 ios->nr_pages = pcol_copy->nr_pages;
517 ios->offset = pcol_copy->pg_first << PAGE_CACHE_SHIFT;
518 ios->length = pcol_copy->length;
519 ios->done = writepages_done;
520 ios->private = pcol_copy;
521
522 ret = exofs_oi_write(oi, ios);
523 if (unlikely(ret)) {
524 EXOFS_ERR("write_exec: exofs_oi_write() Failed\n");
525 goto err;
526 }
527
528 atomic_inc(&pcol->sbi->s_curr_pending);
529 EXOFS_DBGMSG2("write_exec(0x%lx, 0x%llx) start=0x%llx length=0x%lx\n",
530 pcol->inode->i_ino, pcol->pg_first, _LLU(ios->offset),
531 pcol->length);
532 /* pages ownership was passed to pcol_copy */
533 _pcol_reset(pcol);
534 return 0;
535
536 err:
537 _unlock_pcol_pages(pcol, ret, WRITE);
538 pcol_free(pcol);
539 kfree(pcol_copy);
540
541 return ret;
542 }
543
544 /* writepage_strip is called either directly from writepage() or by the VFS from
545 * within write_cache_pages(), to add one more page to be written to storage.
546 * It will try to collect as many contiguous pages as possible. If a
547 * discontinuity is encountered or it runs out of resources it will submit the
548 * previous segment and will start a new collection.
549 * Eventually caller must submit the last segment if present.
550 */
551 static int writepage_strip(struct page *page,
552 struct writeback_control *wbc_unused, void *data)
553 {
554 struct page_collect *pcol = data;
555 struct inode *inode = pcol->inode;
556 struct exofs_i_info *oi = exofs_i(inode);
557 loff_t i_size = i_size_read(inode);
558 pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
559 size_t len;
560 int ret;
561
562 BUG_ON(!PageLocked(page));
563
564 ret = wait_obj_created(oi);
565 if (unlikely(ret))
566 goto fail;
567
568 if (page->index < end_index)
569 /* in this case, the page is within the limits of the file */
570 len = PAGE_CACHE_SIZE;
571 else {
572 len = i_size & ~PAGE_CACHE_MASK;
573
574 if (page->index > end_index || !len) {
575 /* in this case, the page is outside the limits
576 * (truncate in progress)
577 */
578 ret = write_exec(pcol);
579 if (unlikely(ret))
580 goto fail;
581 if (PageError(page))
582 ClearPageError(page);
583 unlock_page(page);
584 EXOFS_DBGMSG("writepage_strip(0x%lx, 0x%lx) "
585 "outside the limits\n",
586 inode->i_ino, page->index);
587 return 0;
588 }
589 }
590
591 try_again:
592
593 if (unlikely(pcol->pg_first == -1)) {
594 pcol->pg_first = page->index;
595 } else if (unlikely((pcol->pg_first + pcol->nr_pages) !=
596 page->index)) {
597 /* Discontinuity detected, split the request */
598 ret = write_exec(pcol);
599 if (unlikely(ret))
600 goto fail;
601
602 EXOFS_DBGMSG("writepage_strip(0x%lx, 0x%lx) Discontinuity\n",
603 inode->i_ino, page->index);
604 goto try_again;
605 }
606
607 if (!pcol->pages) {
608 ret = pcol_try_alloc(pcol);
609 if (unlikely(ret))
610 goto fail;
611 }
612
613 EXOFS_DBGMSG2(" writepage_strip(0x%lx, 0x%lx) len=0x%zx\n",
614 inode->i_ino, page->index, len);
615
616 ret = pcol_add_page(pcol, page, len);
617 if (unlikely(ret)) {
618 EXOFS_DBGMSG2("Failed pcol_add_page "
619 "nr_pages=%u total_length=0x%lx\n",
620 pcol->nr_pages, pcol->length);
621
622 /* split the request, next loop will start again */
623 ret = write_exec(pcol);
624 if (unlikely(ret)) {
625 EXOFS_DBGMSG("write_exec failed => %d", ret);
626 goto fail;
627 }
628
629 goto try_again;
630 }
631
632 BUG_ON(PageWriteback(page));
633 set_page_writeback(page);
634
635 return 0;
636
637 fail:
638 EXOFS_DBGMSG("Error: writepage_strip(0x%lx, 0x%lx)=>%d\n",
639 inode->i_ino, page->index, ret);
640 set_bit(AS_EIO, &page->mapping->flags);
641 unlock_page(page);
642 return ret;
643 }
644
645 static int exofs_writepages(struct address_space *mapping,
646 struct writeback_control *wbc)
647 {
648 struct page_collect pcol;
649 long start, end, expected_pages;
650 int ret;
651
652 start = wbc->range_start >> PAGE_CACHE_SHIFT;
653 end = (wbc->range_end == LLONG_MAX) ?
654 start + mapping->nrpages :
655 wbc->range_end >> PAGE_CACHE_SHIFT;
656
657 if (start || end)
658 expected_pages = end - start + 1;
659 else
660 expected_pages = mapping->nrpages;
661
662 if (expected_pages < 32L)
663 expected_pages = 32L;
664
665 EXOFS_DBGMSG2("inode(0x%lx) wbc->start=0x%llx wbc->end=0x%llx "
666 "nrpages=%lu start=0x%lx end=0x%lx expected_pages=%ld\n",
667 mapping->host->i_ino, wbc->range_start, wbc->range_end,
668 mapping->nrpages, start, end, expected_pages);
669
670 _pcol_init(&pcol, expected_pages, mapping->host);
671
672 ret = write_cache_pages(mapping, wbc, writepage_strip, &pcol);
673 if (ret) {
674 EXOFS_ERR("write_cache_pages => %d\n", ret);
675 return ret;
676 }
677
678 return write_exec(&pcol);
679 }
680
681 static int exofs_writepage(struct page *page, struct writeback_control *wbc)
682 {
683 struct page_collect pcol;
684 int ret;
685
686 _pcol_init(&pcol, 1, page->mapping->host);
687
688 ret = writepage_strip(page, NULL, &pcol);
689 if (ret) {
690 EXOFS_ERR("exofs_writepage => %d\n", ret);
691 return ret;
692 }
693
694 return write_exec(&pcol);
695 }
696
697 /* i_mutex held using inode->i_size directly */
698 static void _write_failed(struct inode *inode, loff_t to)
699 {
700 if (to > inode->i_size)
701 truncate_pagecache(inode, to, inode->i_size);
702 }
703
704 int exofs_write_begin(struct file *file, struct address_space *mapping,
705 loff_t pos, unsigned len, unsigned flags,
706 struct page **pagep, void **fsdata)
707 {
708 int ret = 0;
709 struct page *page;
710
711 page = *pagep;
712 if (page == NULL) {
713 ret = simple_write_begin(file, mapping, pos, len, flags, pagep,
714 fsdata);
715 if (ret) {
716 EXOFS_DBGMSG("simple_write_begin failed\n");
717 goto out;
718 }
719
720 page = *pagep;
721 }
722
723 /* read modify write */
724 if (!PageUptodate(page) && (len != PAGE_CACHE_SIZE)) {
725 ret = _readpage(page, true);
726 if (ret) {
727 /*SetPageError was done by _readpage. Is it ok?*/
728 unlock_page(page);
729 EXOFS_DBGMSG("__readpage_filler failed\n");
730 }
731 }
732 out:
733 if (unlikely(ret))
734 _write_failed(mapping->host, pos + len);
735
736 return ret;
737 }
738
739 static int exofs_write_begin_export(struct file *file,
740 struct address_space *mapping,
741 loff_t pos, unsigned len, unsigned flags,
742 struct page **pagep, void **fsdata)
743 {
744 *pagep = NULL;
745
746 return exofs_write_begin(file, mapping, pos, len, flags, pagep,
747 fsdata);
748 }
749
750 static int exofs_write_end(struct file *file, struct address_space *mapping,
751 loff_t pos, unsigned len, unsigned copied,
752 struct page *page, void *fsdata)
753 {
754 struct inode *inode = mapping->host;
755 /* According to comment in simple_write_end i_mutex is held */
756 loff_t i_size = inode->i_size;
757 int ret;
758
759 ret = simple_write_end(file, mapping,pos, len, copied, page, fsdata);
760 if (unlikely(ret))
761 _write_failed(inode, pos + len);
762
763 /* TODO: once simple_write_end marks inode dirty remove */
764 if (i_size != inode->i_size)
765 mark_inode_dirty(inode);
766 return ret;
767 }
768
769 static int exofs_releasepage(struct page *page, gfp_t gfp)
770 {
771 EXOFS_DBGMSG("page 0x%lx\n", page->index);
772 WARN_ON(1);
773 return 0;
774 }
775
776 static void exofs_invalidatepage(struct page *page, unsigned long offset)
777 {
778 EXOFS_DBGMSG("page 0x%lx offset 0x%lx\n", page->index, offset);
779 WARN_ON(1);
780 }
781
782 const struct address_space_operations exofs_aops = {
783 .readpage = exofs_readpage,
784 .readpages = exofs_readpages,
785 .writepage = exofs_writepage,
786 .writepages = exofs_writepages,
787 .write_begin = exofs_write_begin_export,
788 .write_end = exofs_write_end,
789 .releasepage = exofs_releasepage,
790 .set_page_dirty = __set_page_dirty_nobuffers,
791 .invalidatepage = exofs_invalidatepage,
792
793 /* Not implemented Yet */
794 .bmap = NULL, /* TODO: use osd's OSD_ACT_READ_MAP */
795 .direct_IO = NULL, /* TODO: Should be trivial to do */
796
797 /* With these NULL has special meaning or default is not exported */
798 .sync_page = NULL,
799 .get_xip_mem = NULL,
800 .migratepage = NULL,
801 .launder_page = NULL,
802 .is_partially_uptodate = NULL,
803 .error_remove_page = NULL,
804 };
805
806 /******************************************************************************
807 * INODE OPERATIONS
808 *****************************************************************************/
809
810 /*
811 * Test whether an inode is a fast symlink.
812 */
813 static inline int exofs_inode_is_fast_symlink(struct inode *inode)
814 {
815 struct exofs_i_info *oi = exofs_i(inode);
816
817 return S_ISLNK(inode->i_mode) && (oi->i_data[0] != 0);
818 }
819
820 const struct osd_attr g_attr_logical_length = ATTR_DEF(
821 OSD_APAGE_OBJECT_INFORMATION, OSD_ATTR_OI_LOGICAL_LENGTH, 8);
822
823 static int _do_truncate(struct inode *inode, loff_t newsize)
824 {
825 struct exofs_i_info *oi = exofs_i(inode);
826 int ret;
827
828 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
829
830 ret = exofs_oi_truncate(oi, (u64)newsize);
831 if (likely(!ret))
832 truncate_setsize(inode, newsize);
833
834 EXOFS_DBGMSG("(0x%lx) size=0x%llx ret=>%d\n",
835 inode->i_ino, newsize, ret);
836 return ret;
837 }
838
839 /*
840 * Set inode attributes - update size attribute on OSD if needed,
841 * otherwise just call generic functions.
842 */
843 int exofs_setattr(struct dentry *dentry, struct iattr *iattr)
844 {
845 struct inode *inode = dentry->d_inode;
846 int error;
847
848 /* if we are about to modify an object, and it hasn't been
849 * created yet, wait
850 */
851 error = wait_obj_created(exofs_i(inode));
852 if (unlikely(error))
853 return error;
854
855 error = inode_change_ok(inode, iattr);
856 if (unlikely(error))
857 return error;
858
859 if ((iattr->ia_valid & ATTR_SIZE) &&
860 iattr->ia_size != i_size_read(inode)) {
861 error = _do_truncate(inode, iattr->ia_size);
862 if (unlikely(error))
863 return error;
864 }
865
866 setattr_copy(inode, iattr);
867 mark_inode_dirty(inode);
868 return 0;
869 }
870
871 static const struct osd_attr g_attr_inode_file_layout = ATTR_DEF(
872 EXOFS_APAGE_FS_DATA,
873 EXOFS_ATTR_INODE_FILE_LAYOUT,
874 0);
875 static const struct osd_attr g_attr_inode_dir_layout = ATTR_DEF(
876 EXOFS_APAGE_FS_DATA,
877 EXOFS_ATTR_INODE_DIR_LAYOUT,
878 0);
879
880 /*
881 * Read the Linux inode info from the OSD, and return it as is. In exofs the
882 * inode info is in an application specific page/attribute of the osd-object.
883 */
884 static int exofs_get_inode(struct super_block *sb, struct exofs_i_info *oi,
885 struct exofs_fcb *inode)
886 {
887 struct exofs_sb_info *sbi = sb->s_fs_info;
888 struct osd_attr attrs[] = {
889 [0] = g_attr_inode_data,
890 [1] = g_attr_inode_file_layout,
891 [2] = g_attr_inode_dir_layout,
892 };
893 struct exofs_io_state *ios;
894 struct exofs_on_disk_inode_layout *layout;
895 int ret;
896
897 ret = exofs_get_io_state(&sbi->layout, &ios);
898 if (unlikely(ret)) {
899 EXOFS_ERR("%s: exofs_get_io_state failed.\n", __func__);
900 return ret;
901 }
902
903 ios->obj.id = exofs_oi_objno(oi);
904 exofs_make_credential(oi->i_cred, &ios->obj);
905 ios->cred = oi->i_cred;
906
907 attrs[1].len = exofs_on_disk_inode_layout_size(sbi->layout.s_numdevs);
908 attrs[2].len = exofs_on_disk_inode_layout_size(sbi->layout.s_numdevs);
909
910 ios->in_attr = attrs;
911 ios->in_attr_len = ARRAY_SIZE(attrs);
912
913 ret = exofs_sbi_read(ios);
914 if (unlikely(ret)) {
915 EXOFS_ERR("object(0x%llx) corrupted, return empty file=>%d\n",
916 _LLU(ios->obj.id), ret);
917 memset(inode, 0, sizeof(*inode));
918 inode->i_mode = 0040000 | (0777 & ~022);
919 /* If object is lost on target we might as well enable it's
920 * delete.
921 */
922 if ((ret == -ENOENT) || (ret == -EINVAL))
923 ret = 0;
924 goto out;
925 }
926
927 ret = extract_attr_from_ios(ios, &attrs[0]);
928 if (ret) {
929 EXOFS_ERR("%s: extract_attr of inode_data failed\n", __func__);
930 goto out;
931 }
932 WARN_ON(attrs[0].len != EXOFS_INO_ATTR_SIZE);
933 memcpy(inode, attrs[0].val_ptr, EXOFS_INO_ATTR_SIZE);
934
935 ret = extract_attr_from_ios(ios, &attrs[1]);
936 if (ret) {
937 EXOFS_ERR("%s: extract_attr of inode_data failed\n", __func__);
938 goto out;
939 }
940 if (attrs[1].len) {
941 layout = attrs[1].val_ptr;
942 if (layout->gen_func != cpu_to_le16(LAYOUT_MOVING_WINDOW)) {
943 EXOFS_ERR("%s: unsupported files layout %d\n",
944 __func__, layout->gen_func);
945 ret = -ENOTSUPP;
946 goto out;
947 }
948 }
949
950 ret = extract_attr_from_ios(ios, &attrs[2]);
951 if (ret) {
952 EXOFS_ERR("%s: extract_attr of inode_data failed\n", __func__);
953 goto out;
954 }
955 if (attrs[2].len) {
956 layout = attrs[2].val_ptr;
957 if (layout->gen_func != cpu_to_le16(LAYOUT_MOVING_WINDOW)) {
958 EXOFS_ERR("%s: unsupported meta-data layout %d\n",
959 __func__, layout->gen_func);
960 ret = -ENOTSUPP;
961 goto out;
962 }
963 }
964
965 out:
966 exofs_put_io_state(ios);
967 return ret;
968 }
969
970 static void __oi_init(struct exofs_i_info *oi)
971 {
972 init_waitqueue_head(&oi->i_wq);
973 oi->i_flags = 0;
974 }
975 /*
976 * Fill in an inode read from the OSD and set it up for use
977 */
978 struct inode *exofs_iget(struct super_block *sb, unsigned long ino)
979 {
980 struct exofs_i_info *oi;
981 struct exofs_fcb fcb;
982 struct inode *inode;
983 int ret;
984
985 inode = iget_locked(sb, ino);
986 if (!inode)
987 return ERR_PTR(-ENOMEM);
988 if (!(inode->i_state & I_NEW))
989 return inode;
990 oi = exofs_i(inode);
991 __oi_init(oi);
992
993 /* read the inode from the osd */
994 ret = exofs_get_inode(sb, oi, &fcb);
995 if (ret)
996 goto bad_inode;
997
998 set_obj_created(oi);
999
1000 /* copy stuff from on-disk struct to in-memory struct */
1001 inode->i_mode = le16_to_cpu(fcb.i_mode);
1002 inode->i_uid = le32_to_cpu(fcb.i_uid);
1003 inode->i_gid = le32_to_cpu(fcb.i_gid);
1004 inode->i_nlink = le16_to_cpu(fcb.i_links_count);
1005 inode->i_ctime.tv_sec = (signed)le32_to_cpu(fcb.i_ctime);
1006 inode->i_atime.tv_sec = (signed)le32_to_cpu(fcb.i_atime);
1007 inode->i_mtime.tv_sec = (signed)le32_to_cpu(fcb.i_mtime);
1008 inode->i_ctime.tv_nsec =
1009 inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = 0;
1010 oi->i_commit_size = le64_to_cpu(fcb.i_size);
1011 i_size_write(inode, oi->i_commit_size);
1012 inode->i_blkbits = EXOFS_BLKSHIFT;
1013 inode->i_generation = le32_to_cpu(fcb.i_generation);
1014
1015 oi->i_dir_start_lookup = 0;
1016
1017 if ((inode->i_nlink == 0) && (inode->i_mode == 0)) {
1018 ret = -ESTALE;
1019 goto bad_inode;
1020 }
1021
1022 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
1023 if (fcb.i_data[0])
1024 inode->i_rdev =
1025 old_decode_dev(le32_to_cpu(fcb.i_data[0]));
1026 else
1027 inode->i_rdev =
1028 new_decode_dev(le32_to_cpu(fcb.i_data[1]));
1029 } else {
1030 memcpy(oi->i_data, fcb.i_data, sizeof(fcb.i_data));
1031 }
1032
1033 if (S_ISREG(inode->i_mode)) {
1034 inode->i_op = &exofs_file_inode_operations;
1035 inode->i_fop = &exofs_file_operations;
1036 inode->i_mapping->a_ops = &exofs_aops;
1037 } else if (S_ISDIR(inode->i_mode)) {
1038 inode->i_op = &exofs_dir_inode_operations;
1039 inode->i_fop = &exofs_dir_operations;
1040 inode->i_mapping->a_ops = &exofs_aops;
1041 } else if (S_ISLNK(inode->i_mode)) {
1042 if (exofs_inode_is_fast_symlink(inode))
1043 inode->i_op = &exofs_fast_symlink_inode_operations;
1044 else {
1045 inode->i_op = &exofs_symlink_inode_operations;
1046 inode->i_mapping->a_ops = &exofs_aops;
1047 }
1048 } else {
1049 inode->i_op = &exofs_special_inode_operations;
1050 if (fcb.i_data[0])
1051 init_special_inode(inode, inode->i_mode,
1052 old_decode_dev(le32_to_cpu(fcb.i_data[0])));
1053 else
1054 init_special_inode(inode, inode->i_mode,
1055 new_decode_dev(le32_to_cpu(fcb.i_data[1])));
1056 }
1057
1058 unlock_new_inode(inode);
1059 return inode;
1060
1061 bad_inode:
1062 iget_failed(inode);
1063 return ERR_PTR(ret);
1064 }
1065
1066 int __exofs_wait_obj_created(struct exofs_i_info *oi)
1067 {
1068 if (!obj_created(oi)) {
1069 EXOFS_DBGMSG("!obj_created\n");
1070 BUG_ON(!obj_2bcreated(oi));
1071 wait_event(oi->i_wq, obj_created(oi));
1072 EXOFS_DBGMSG("wait_event done\n");
1073 }
1074 return unlikely(is_bad_inode(&oi->vfs_inode)) ? -EIO : 0;
1075 }
1076 /*
1077 * Callback function from exofs_new_inode(). The important thing is that we
1078 * set the obj_created flag so that other methods know that the object exists on
1079 * the OSD.
1080 */
1081 static void create_done(struct exofs_io_state *ios, void *p)
1082 {
1083 struct inode *inode = p;
1084 struct exofs_i_info *oi = exofs_i(inode);
1085 struct exofs_sb_info *sbi = inode->i_sb->s_fs_info;
1086 int ret;
1087
1088 ret = exofs_check_io(ios, NULL);
1089 exofs_put_io_state(ios);
1090
1091 atomic_dec(&sbi->s_curr_pending);
1092
1093 if (unlikely(ret)) {
1094 EXOFS_ERR("object=0x%llx creation failed in pid=0x%llx",
1095 _LLU(exofs_oi_objno(oi)), _LLU(sbi->layout.s_pid));
1096 /*TODO: When FS is corrupted creation can fail, object already
1097 * exist. Get rid of this asynchronous creation, if exist
1098 * increment the obj counter and try the next object. Until we
1099 * succeed. All these dangling objects will be made into lost
1100 * files by chkfs.exofs
1101 */
1102 }
1103
1104 set_obj_created(oi);
1105
1106 wake_up(&oi->i_wq);
1107 }
1108
1109 /*
1110 * Set up a new inode and create an object for it on the OSD
1111 */
1112 struct inode *exofs_new_inode(struct inode *dir, int mode)
1113 {
1114 struct super_block *sb;
1115 struct inode *inode;
1116 struct exofs_i_info *oi;
1117 struct exofs_sb_info *sbi;
1118 struct exofs_io_state *ios;
1119 int ret;
1120
1121 sb = dir->i_sb;
1122 inode = new_inode(sb);
1123 if (!inode)
1124 return ERR_PTR(-ENOMEM);
1125
1126 oi = exofs_i(inode);
1127 __oi_init(oi);
1128
1129 set_obj_2bcreated(oi);
1130
1131 sbi = sb->s_fs_info;
1132
1133 sb->s_dirt = 1;
1134 inode_init_owner(inode, dir, mode);
1135 inode->i_ino = sbi->s_nextid++;
1136 inode->i_blkbits = EXOFS_BLKSHIFT;
1137 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1138 oi->i_commit_size = inode->i_size = 0;
1139 spin_lock(&sbi->s_next_gen_lock);
1140 inode->i_generation = sbi->s_next_generation++;
1141 spin_unlock(&sbi->s_next_gen_lock);
1142 insert_inode_hash(inode);
1143
1144 mark_inode_dirty(inode);
1145
1146 ret = exofs_get_io_state(&sbi->layout, &ios);
1147 if (unlikely(ret)) {
1148 EXOFS_ERR("exofs_new_inode: exofs_get_io_state failed\n");
1149 return ERR_PTR(ret);
1150 }
1151
1152 ios->obj.id = exofs_oi_objno(oi);
1153 exofs_make_credential(oi->i_cred, &ios->obj);
1154
1155 ios->done = create_done;
1156 ios->private = inode;
1157 ios->cred = oi->i_cred;
1158 ret = exofs_sbi_create(ios);
1159 if (ret) {
1160 exofs_put_io_state(ios);
1161 return ERR_PTR(ret);
1162 }
1163 atomic_inc(&sbi->s_curr_pending);
1164
1165 return inode;
1166 }
1167
1168 /*
1169 * struct to pass two arguments to update_inode's callback
1170 */
1171 struct updatei_args {
1172 struct exofs_sb_info *sbi;
1173 struct exofs_fcb fcb;
1174 };
1175
1176 /*
1177 * Callback function from exofs_update_inode().
1178 */
1179 static void updatei_done(struct exofs_io_state *ios, void *p)
1180 {
1181 struct updatei_args *args = p;
1182
1183 exofs_put_io_state(ios);
1184
1185 atomic_dec(&args->sbi->s_curr_pending);
1186
1187 kfree(args);
1188 }
1189
1190 /*
1191 * Write the inode to the OSD. Just fill up the struct, and set the attribute
1192 * synchronously or asynchronously depending on the do_sync flag.
1193 */
1194 static int exofs_update_inode(struct inode *inode, int do_sync)
1195 {
1196 struct exofs_i_info *oi = exofs_i(inode);
1197 struct super_block *sb = inode->i_sb;
1198 struct exofs_sb_info *sbi = sb->s_fs_info;
1199 struct exofs_io_state *ios;
1200 struct osd_attr attr;
1201 struct exofs_fcb *fcb;
1202 struct updatei_args *args;
1203 int ret;
1204
1205 args = kzalloc(sizeof(*args), GFP_KERNEL);
1206 if (!args) {
1207 EXOFS_DBGMSG("Failed kzalloc of args\n");
1208 return -ENOMEM;
1209 }
1210
1211 fcb = &args->fcb;
1212
1213 fcb->i_mode = cpu_to_le16(inode->i_mode);
1214 fcb->i_uid = cpu_to_le32(inode->i_uid);
1215 fcb->i_gid = cpu_to_le32(inode->i_gid);
1216 fcb->i_links_count = cpu_to_le16(inode->i_nlink);
1217 fcb->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
1218 fcb->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
1219 fcb->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
1220 oi->i_commit_size = i_size_read(inode);
1221 fcb->i_size = cpu_to_le64(oi->i_commit_size);
1222 fcb->i_generation = cpu_to_le32(inode->i_generation);
1223
1224 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
1225 if (old_valid_dev(inode->i_rdev)) {
1226 fcb->i_data[0] =
1227 cpu_to_le32(old_encode_dev(inode->i_rdev));
1228 fcb->i_data[1] = 0;
1229 } else {
1230 fcb->i_data[0] = 0;
1231 fcb->i_data[1] =
1232 cpu_to_le32(new_encode_dev(inode->i_rdev));
1233 fcb->i_data[2] = 0;
1234 }
1235 } else
1236 memcpy(fcb->i_data, oi->i_data, sizeof(fcb->i_data));
1237
1238 ret = exofs_get_io_state(&sbi->layout, &ios);
1239 if (unlikely(ret)) {
1240 EXOFS_ERR("%s: exofs_get_io_state failed.\n", __func__);
1241 goto free_args;
1242 }
1243
1244 attr = g_attr_inode_data;
1245 attr.val_ptr = fcb;
1246 ios->out_attr_len = 1;
1247 ios->out_attr = &attr;
1248
1249 wait_obj_created(oi);
1250
1251 if (!do_sync) {
1252 args->sbi = sbi;
1253 ios->done = updatei_done;
1254 ios->private = args;
1255 }
1256
1257 ret = exofs_oi_write(oi, ios);
1258 if (!do_sync && !ret) {
1259 atomic_inc(&sbi->s_curr_pending);
1260 goto out; /* deallocation in updatei_done */
1261 }
1262
1263 exofs_put_io_state(ios);
1264 free_args:
1265 kfree(args);
1266 out:
1267 EXOFS_DBGMSG("(0x%lx) do_sync=%d ret=>%d\n",
1268 inode->i_ino, do_sync, ret);
1269 return ret;
1270 }
1271
1272 int exofs_write_inode(struct inode *inode, struct writeback_control *wbc)
1273 {
1274 return exofs_update_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
1275 }
1276
1277 /*
1278 * Callback function from exofs_delete_inode() - don't have much cleaning up to
1279 * do.
1280 */
1281 static void delete_done(struct exofs_io_state *ios, void *p)
1282 {
1283 struct exofs_sb_info *sbi = p;
1284
1285 exofs_put_io_state(ios);
1286
1287 atomic_dec(&sbi->s_curr_pending);
1288 }
1289
1290 /*
1291 * Called when the refcount of an inode reaches zero. We remove the object
1292 * from the OSD here. We make sure the object was created before we try and
1293 * delete it.
1294 */
1295 void exofs_evict_inode(struct inode *inode)
1296 {
1297 struct exofs_i_info *oi = exofs_i(inode);
1298 struct super_block *sb = inode->i_sb;
1299 struct exofs_sb_info *sbi = sb->s_fs_info;
1300 struct exofs_io_state *ios;
1301 int ret;
1302
1303 truncate_inode_pages(&inode->i_data, 0);
1304
1305 /* TODO: should do better here */
1306 if (inode->i_nlink || is_bad_inode(inode))
1307 goto no_delete;
1308
1309 inode->i_size = 0;
1310 end_writeback(inode);
1311
1312 /* if we are deleting an obj that hasn't been created yet, wait.
1313 * This also makes sure that create_done cannot be called with an
1314 * already evicted inode.
1315 */
1316 wait_obj_created(oi);
1317 /* ignore the error, attempt a remove anyway */
1318
1319 /* Now Remove the OSD objects */
1320 ret = exofs_get_io_state(&sbi->layout, &ios);
1321 if (unlikely(ret)) {
1322 EXOFS_ERR("%s: exofs_get_io_state failed\n", __func__);
1323 return;
1324 }
1325
1326 ios->obj.id = exofs_oi_objno(oi);
1327 ios->done = delete_done;
1328 ios->private = sbi;
1329 ios->cred = oi->i_cred;
1330 ret = exofs_sbi_remove(ios);
1331 if (ret) {
1332 EXOFS_ERR("%s: exofs_sbi_remove failed\n", __func__);
1333 exofs_put_io_state(ios);
1334 return;
1335 }
1336 atomic_inc(&sbi->s_curr_pending);
1337
1338 return;
1339
1340 no_delete:
1341 end_writeback(inode);
1342 }
Linux with added FPC-III support