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exofs: Add offset/length to exofs_get_io_state
[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 /* TODO: easily support bio chaining */
114 pages = exofs_max_io_pages(&pcol->sbi->layout, pcol->expected_pages);
115
116 for (; pages; pages >>= 1) {
117 pcol->pages = kmalloc(pages * sizeof(struct page *),
118 GFP_KERNEL);
119 if (likely(pcol->pages)) {
120 pcol->alloc_pages = pages;
121 return 0;
122 }
123 }
124
125 EXOFS_ERR("Failed to kmalloc expected_pages=%u\n",
126 pcol->expected_pages);
127 return -ENOMEM;
128 }
129
130 static void pcol_free(struct page_collect *pcol)
131 {
132 kfree(pcol->pages);
133 pcol->pages = NULL;
134
135 if (pcol->ios) {
136 exofs_put_io_state(pcol->ios);
137 pcol->ios = NULL;
138 }
139 }
140
141 static int pcol_add_page(struct page_collect *pcol, struct page *page,
142 unsigned len)
143 {
144 if (unlikely(pcol->nr_pages >= pcol->alloc_pages))
145 return -ENOMEM;
146
147 pcol->pages[pcol->nr_pages++] = page;
148 pcol->length += len;
149 return 0;
150 }
151
152 static int update_read_page(struct page *page, int ret)
153 {
154 if (ret == 0) {
155 /* Everything is OK */
156 SetPageUptodate(page);
157 if (PageError(page))
158 ClearPageError(page);
159 } else if (ret == -EFAULT) {
160 /* In this case we were trying to read something that wasn't on
161 * disk yet - return a page full of zeroes. This should be OK,
162 * because the object should be empty (if there was a write
163 * before this read, the read would be waiting with the page
164 * locked */
165 clear_highpage(page);
166
167 SetPageUptodate(page);
168 if (PageError(page))
169 ClearPageError(page);
170 ret = 0; /* recovered error */
171 EXOFS_DBGMSG("recovered read error\n");
172 } else /* Error */
173 SetPageError(page);
174
175 return ret;
176 }
177
178 static void update_write_page(struct page *page, int ret)
179 {
180 if (ret) {
181 mapping_set_error(page->mapping, ret);
182 SetPageError(page);
183 }
184 end_page_writeback(page);
185 }
186
187 /* Called at the end of reads, to optionally unlock pages and update their
188 * status.
189 */
190 static int __readpages_done(struct page_collect *pcol)
191 {
192 int i;
193 u64 resid;
194 u64 good_bytes;
195 u64 length = 0;
196 int ret = exofs_check_io(pcol->ios, &resid);
197
198 if (likely(!ret))
199 good_bytes = pcol->length;
200 else
201 good_bytes = pcol->length - resid;
202
203 EXOFS_DBGMSG2("readpages_done(0x%lx) good_bytes=0x%llx"
204 " length=0x%lx nr_pages=%u\n",
205 pcol->inode->i_ino, _LLU(good_bytes), pcol->length,
206 pcol->nr_pages);
207
208 for (i = 0; i < pcol->nr_pages; i++) {
209 struct page *page = pcol->pages[i];
210 struct inode *inode = page->mapping->host;
211 int page_stat;
212
213 if (inode != pcol->inode)
214 continue; /* osd might add more pages at end */
215
216 if (likely(length < good_bytes))
217 page_stat = 0;
218 else
219 page_stat = ret;
220
221 EXOFS_DBGMSG2(" readpages_done(0x%lx, 0x%lx) %s\n",
222 inode->i_ino, page->index,
223 page_stat ? "bad_bytes" : "good_bytes");
224
225 ret = update_read_page(page, page_stat);
226 if (!pcol->read_4_write)
227 unlock_page(page);
228 length += PAGE_SIZE;
229 }
230
231 pcol_free(pcol);
232 EXOFS_DBGMSG2("readpages_done END\n");
233 return ret;
234 }
235
236 /* callback of async reads */
237 static void readpages_done(struct exofs_io_state *ios, void *p)
238 {
239 struct page_collect *pcol = p;
240
241 __readpages_done(pcol);
242 atomic_dec(&pcol->sbi->s_curr_pending);
243 kfree(pcol);
244 }
245
246 static void _unlock_pcol_pages(struct page_collect *pcol, int ret, int rw)
247 {
248 int i;
249
250 for (i = 0; i < pcol->nr_pages; i++) {
251 struct page *page = pcol->pages[i];
252
253 if (rw == READ)
254 update_read_page(page, ret);
255 else
256 update_write_page(page, ret);
257
258 unlock_page(page);
259 }
260 }
261
262 static int read_exec(struct page_collect *pcol)
263 {
264 struct exofs_i_info *oi = exofs_i(pcol->inode);
265 struct exofs_io_state *ios;
266 struct page_collect *pcol_copy = NULL;
267 int ret;
268
269 if (!pcol->pages)
270 return 0;
271
272 if (!pcol->ios) {
273 int ret = exofs_get_rw_state(&pcol->sbi->layout, true,
274 pcol->pg_first << PAGE_CACHE_SHIFT,
275 pcol->length, &pcol->ios);
276
277 if (ret)
278 return ret;
279 }
280
281 ios = pcol->ios;
282 ios->pages = pcol->pages;
283 ios->nr_pages = pcol->nr_pages;
284
285 if (pcol->read_4_write) {
286 exofs_oi_read(oi, pcol->ios);
287 return __readpages_done(pcol);
288 }
289
290 pcol_copy = kmalloc(sizeof(*pcol_copy), GFP_KERNEL);
291 if (!pcol_copy) {
292 ret = -ENOMEM;
293 goto err;
294 }
295
296 *pcol_copy = *pcol;
297 ios->done = readpages_done;
298 ios->private = pcol_copy;
299 ret = exofs_oi_read(oi, ios);
300 if (unlikely(ret))
301 goto err;
302
303 atomic_inc(&pcol->sbi->s_curr_pending);
304
305 EXOFS_DBGMSG2("read_exec obj=0x%llx start=0x%llx length=0x%lx\n",
306 ios->obj.id, _LLU(ios->offset), pcol->length);
307
308 /* pages ownership was passed to pcol_copy */
309 _pcol_reset(pcol);
310 return 0;
311
312 err:
313 if (!pcol->read_4_write)
314 _unlock_pcol_pages(pcol, ret, READ);
315
316 pcol_free(pcol);
317
318 kfree(pcol_copy);
319 return ret;
320 }
321
322 /* readpage_strip is called either directly from readpage() or by the VFS from
323 * within read_cache_pages(), to add one more page to be read. It will try to
324 * collect as many contiguous pages as posible. If a discontinuity is
325 * encountered, or it runs out of resources, it will submit the previous segment
326 * and will start a new collection. Eventually caller must submit the last
327 * segment if present.
328 */
329 static int readpage_strip(void *data, struct page *page)
330 {
331 struct page_collect *pcol = data;
332 struct inode *inode = pcol->inode;
333 struct exofs_i_info *oi = exofs_i(inode);
334 loff_t i_size = i_size_read(inode);
335 pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
336 size_t len;
337 int ret;
338
339 /* FIXME: Just for debugging, will be removed */
340 if (PageUptodate(page))
341 EXOFS_ERR("PageUptodate(0x%lx, 0x%lx)\n", pcol->inode->i_ino,
342 page->index);
343
344 if (page->index < end_index)
345 len = PAGE_CACHE_SIZE;
346 else if (page->index == end_index)
347 len = i_size & ~PAGE_CACHE_MASK;
348 else
349 len = 0;
350
351 if (!len || !obj_created(oi)) {
352 /* this will be out of bounds, or doesn't exist yet.
353 * Current page is cleared and the request is split
354 */
355 clear_highpage(page);
356
357 SetPageUptodate(page);
358 if (PageError(page))
359 ClearPageError(page);
360
361 if (!pcol->read_4_write)
362 unlock_page(page);
363 EXOFS_DBGMSG("readpage_strip(0x%lx) empty page len=%zx "
364 "read_4_write=%d index=0x%lx end_index=0x%lx "
365 "splitting\n", inode->i_ino, len,
366 pcol->read_4_write, page->index, end_index);
367
368 return read_exec(pcol);
369 }
370
371 try_again:
372
373 if (unlikely(pcol->pg_first == -1)) {
374 pcol->pg_first = page->index;
375 } else if (unlikely((pcol->pg_first + pcol->nr_pages) !=
376 page->index)) {
377 /* Discontinuity detected, split the request */
378 ret = read_exec(pcol);
379 if (unlikely(ret))
380 goto fail;
381 goto try_again;
382 }
383
384 if (!pcol->pages) {
385 ret = pcol_try_alloc(pcol);
386 if (unlikely(ret))
387 goto fail;
388 }
389
390 if (len != PAGE_CACHE_SIZE)
391 zero_user(page, len, PAGE_CACHE_SIZE - len);
392
393 EXOFS_DBGMSG2(" readpage_strip(0x%lx, 0x%lx) len=0x%zx\n",
394 inode->i_ino, page->index, len);
395
396 ret = pcol_add_page(pcol, page, len);
397 if (ret) {
398 EXOFS_DBGMSG2("Failed pcol_add_page pages[i]=%p "
399 "this_len=0x%zx nr_pages=%u length=0x%lx\n",
400 page, len, pcol->nr_pages, pcol->length);
401
402 /* split the request, and start again with current page */
403 ret = read_exec(pcol);
404 if (unlikely(ret))
405 goto fail;
406
407 goto try_again;
408 }
409
410 return 0;
411
412 fail:
413 /* SetPageError(page); ??? */
414 unlock_page(page);
415 return ret;
416 }
417
418 static int exofs_readpages(struct file *file, struct address_space *mapping,
419 struct list_head *pages, unsigned nr_pages)
420 {
421 struct page_collect pcol;
422 int ret;
423
424 _pcol_init(&pcol, nr_pages, mapping->host);
425
426 ret = read_cache_pages(mapping, pages, readpage_strip, &pcol);
427 if (ret) {
428 EXOFS_ERR("read_cache_pages => %d\n", ret);
429 return ret;
430 }
431
432 return read_exec(&pcol);
433 }
434
435 static int _readpage(struct page *page, bool read_4_write)
436 {
437 struct page_collect pcol;
438 int ret;
439
440 _pcol_init(&pcol, 1, page->mapping->host);
441
442 pcol.read_4_write = read_4_write;
443 ret = readpage_strip(&pcol, page);
444 if (ret) {
445 EXOFS_ERR("_readpage => %d\n", ret);
446 return ret;
447 }
448
449 return read_exec(&pcol);
450 }
451
452 /*
453 * We don't need the file
454 */
455 static int exofs_readpage(struct file *file, struct page *page)
456 {
457 return _readpage(page, false);
458 }
459
460 /* Callback for osd_write. All writes are asynchronous */
461 static void writepages_done(struct exofs_io_state *ios, void *p)
462 {
463 struct page_collect *pcol = p;
464 int i;
465 u64 resid;
466 u64 good_bytes;
467 u64 length = 0;
468 int ret = exofs_check_io(ios, &resid);
469
470 atomic_dec(&pcol->sbi->s_curr_pending);
471
472 if (likely(!ret))
473 good_bytes = pcol->length;
474 else
475 good_bytes = pcol->length - resid;
476
477 EXOFS_DBGMSG2("writepages_done(0x%lx) good_bytes=0x%llx"
478 " length=0x%lx nr_pages=%u\n",
479 pcol->inode->i_ino, _LLU(good_bytes), pcol->length,
480 pcol->nr_pages);
481
482 for (i = 0; i < pcol->nr_pages; i++) {
483 struct page *page = pcol->pages[i];
484 struct inode *inode = page->mapping->host;
485 int page_stat;
486
487 if (inode != pcol->inode)
488 continue; /* osd might add more pages to a bio */
489
490 if (likely(length < good_bytes))
491 page_stat = 0;
492 else
493 page_stat = ret;
494
495 update_write_page(page, page_stat);
496 unlock_page(page);
497 EXOFS_DBGMSG2(" writepages_done(0x%lx, 0x%lx) status=%d\n",
498 inode->i_ino, page->index, page_stat);
499
500 length += PAGE_SIZE;
501 }
502
503 pcol_free(pcol);
504 kfree(pcol);
505 EXOFS_DBGMSG2("writepages_done END\n");
506 }
507
508 static int write_exec(struct page_collect *pcol)
509 {
510 struct exofs_i_info *oi = exofs_i(pcol->inode);
511 struct exofs_io_state *ios;
512 struct page_collect *pcol_copy = NULL;
513 int ret;
514
515 if (!pcol->pages)
516 return 0;
517
518 BUG_ON(pcol->ios);
519 ret = exofs_get_rw_state(&pcol->sbi->layout, false,
520 pcol->pg_first << PAGE_CACHE_SHIFT,
521 pcol->length, &pcol->ios);
522
523 if (unlikely(ret))
524 goto err;
525
526 pcol_copy = kmalloc(sizeof(*pcol_copy), GFP_KERNEL);
527 if (!pcol_copy) {
528 EXOFS_ERR("write_exec: Failed to kmalloc(pcol)\n");
529 ret = -ENOMEM;
530 goto err;
531 }
532
533 *pcol_copy = *pcol;
534
535 ios = pcol->ios;
536 ios->pages = pcol_copy->pages;
537 ios->nr_pages = pcol_copy->nr_pages;
538 ios->done = writepages_done;
539 ios->private = pcol_copy;
540
541 ret = exofs_oi_write(oi, ios);
542 if (unlikely(ret)) {
543 EXOFS_ERR("write_exec: exofs_oi_write() Failed\n");
544 goto err;
545 }
546
547 atomic_inc(&pcol->sbi->s_curr_pending);
548 EXOFS_DBGMSG2("write_exec(0x%lx, 0x%llx) start=0x%llx length=0x%lx\n",
549 pcol->inode->i_ino, pcol->pg_first, _LLU(ios->offset),
550 pcol->length);
551 /* pages ownership was passed to pcol_copy */
552 _pcol_reset(pcol);
553 return 0;
554
555 err:
556 _unlock_pcol_pages(pcol, ret, WRITE);
557 pcol_free(pcol);
558 kfree(pcol_copy);
559
560 return ret;
561 }
562
563 /* writepage_strip is called either directly from writepage() or by the VFS from
564 * within write_cache_pages(), to add one more page to be written to storage.
565 * It will try to collect as many contiguous pages as possible. If a
566 * discontinuity is encountered or it runs out of resources it will submit the
567 * previous segment and will start a new collection.
568 * Eventually caller must submit the last segment if present.
569 */
570 static int writepage_strip(struct page *page,
571 struct writeback_control *wbc_unused, void *data)
572 {
573 struct page_collect *pcol = data;
574 struct inode *inode = pcol->inode;
575 struct exofs_i_info *oi = exofs_i(inode);
576 loff_t i_size = i_size_read(inode);
577 pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
578 size_t len;
579 int ret;
580
581 BUG_ON(!PageLocked(page));
582
583 ret = wait_obj_created(oi);
584 if (unlikely(ret))
585 goto fail;
586
587 if (page->index < end_index)
588 /* in this case, the page is within the limits of the file */
589 len = PAGE_CACHE_SIZE;
590 else {
591 len = i_size & ~PAGE_CACHE_MASK;
592
593 if (page->index > end_index || !len) {
594 /* in this case, the page is outside the limits
595 * (truncate in progress)
596 */
597 ret = write_exec(pcol);
598 if (unlikely(ret))
599 goto fail;
600 if (PageError(page))
601 ClearPageError(page);
602 unlock_page(page);
603 EXOFS_DBGMSG("writepage_strip(0x%lx, 0x%lx) "
604 "outside the limits\n",
605 inode->i_ino, page->index);
606 return 0;
607 }
608 }
609
610 try_again:
611
612 if (unlikely(pcol->pg_first == -1)) {
613 pcol->pg_first = page->index;
614 } else if (unlikely((pcol->pg_first + pcol->nr_pages) !=
615 page->index)) {
616 /* Discontinuity detected, split the request */
617 ret = write_exec(pcol);
618 if (unlikely(ret))
619 goto fail;
620
621 EXOFS_DBGMSG("writepage_strip(0x%lx, 0x%lx) Discontinuity\n",
622 inode->i_ino, page->index);
623 goto try_again;
624 }
625
626 if (!pcol->pages) {
627 ret = pcol_try_alloc(pcol);
628 if (unlikely(ret))
629 goto fail;
630 }
631
632 EXOFS_DBGMSG2(" writepage_strip(0x%lx, 0x%lx) len=0x%zx\n",
633 inode->i_ino, page->index, len);
634
635 ret = pcol_add_page(pcol, page, len);
636 if (unlikely(ret)) {
637 EXOFS_DBGMSG2("Failed pcol_add_page "
638 "nr_pages=%u total_length=0x%lx\n",
639 pcol->nr_pages, pcol->length);
640
641 /* split the request, next loop will start again */
642 ret = write_exec(pcol);
643 if (unlikely(ret)) {
644 EXOFS_DBGMSG("write_exec failed => %d", ret);
645 goto fail;
646 }
647
648 goto try_again;
649 }
650
651 BUG_ON(PageWriteback(page));
652 set_page_writeback(page);
653
654 return 0;
655
656 fail:
657 EXOFS_DBGMSG("Error: writepage_strip(0x%lx, 0x%lx)=>%d\n",
658 inode->i_ino, page->index, ret);
659 set_bit(AS_EIO, &page->mapping->flags);
660 unlock_page(page);
661 return ret;
662 }
663
664 static int exofs_writepages(struct address_space *mapping,
665 struct writeback_control *wbc)
666 {
667 struct page_collect pcol;
668 long start, end, expected_pages;
669 int ret;
670
671 start = wbc->range_start >> PAGE_CACHE_SHIFT;
672 end = (wbc->range_end == LLONG_MAX) ?
673 start + mapping->nrpages :
674 wbc->range_end >> PAGE_CACHE_SHIFT;
675
676 if (start || end)
677 expected_pages = end - start + 1;
678 else
679 expected_pages = mapping->nrpages;
680
681 if (expected_pages < 32L)
682 expected_pages = 32L;
683
684 EXOFS_DBGMSG2("inode(0x%lx) wbc->start=0x%llx wbc->end=0x%llx "
685 "nrpages=%lu start=0x%lx end=0x%lx expected_pages=%ld\n",
686 mapping->host->i_ino, wbc->range_start, wbc->range_end,
687 mapping->nrpages, start, end, expected_pages);
688
689 _pcol_init(&pcol, expected_pages, mapping->host);
690
691 ret = write_cache_pages(mapping, wbc, writepage_strip, &pcol);
692 if (ret) {
693 EXOFS_ERR("write_cache_pages => %d\n", ret);
694 return ret;
695 }
696
697 return write_exec(&pcol);
698 }
699
700 static int exofs_writepage(struct page *page, struct writeback_control *wbc)
701 {
702 struct page_collect pcol;
703 int ret;
704
705 _pcol_init(&pcol, 1, page->mapping->host);
706
707 ret = writepage_strip(page, NULL, &pcol);
708 if (ret) {
709 EXOFS_ERR("exofs_writepage => %d\n", ret);
710 return ret;
711 }
712
713 return write_exec(&pcol);
714 }
715
716 /* i_mutex held using inode->i_size directly */
717 static void _write_failed(struct inode *inode, loff_t to)
718 {
719 if (to > inode->i_size)
720 truncate_pagecache(inode, to, inode->i_size);
721 }
722
723 int exofs_write_begin(struct file *file, struct address_space *mapping,
724 loff_t pos, unsigned len, unsigned flags,
725 struct page **pagep, void **fsdata)
726 {
727 int ret = 0;
728 struct page *page;
729
730 page = *pagep;
731 if (page == NULL) {
732 ret = simple_write_begin(file, mapping, pos, len, flags, pagep,
733 fsdata);
734 if (ret) {
735 EXOFS_DBGMSG("simple_write_begin failed\n");
736 goto out;
737 }
738
739 page = *pagep;
740 }
741
742 /* read modify write */
743 if (!PageUptodate(page) && (len != PAGE_CACHE_SIZE)) {
744 loff_t i_size = i_size_read(mapping->host);
745 pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
746 size_t rlen;
747
748 if (page->index < end_index)
749 rlen = PAGE_CACHE_SIZE;
750 else if (page->index == end_index)
751 rlen = i_size & ~PAGE_CACHE_MASK;
752 else
753 rlen = 0;
754
755 if (!rlen) {
756 clear_highpage(page);
757 SetPageUptodate(page);
758 goto out;
759 }
760
761 ret = _readpage(page, true);
762 if (ret) {
763 /*SetPageError was done by _readpage. Is it ok?*/
764 unlock_page(page);
765 EXOFS_DBGMSG("__readpage failed\n");
766 }
767 }
768 out:
769 if (unlikely(ret))
770 _write_failed(mapping->host, pos + len);
771
772 return ret;
773 }
774
775 static int exofs_write_begin_export(struct file *file,
776 struct address_space *mapping,
777 loff_t pos, unsigned len, unsigned flags,
778 struct page **pagep, void **fsdata)
779 {
780 *pagep = NULL;
781
782 return exofs_write_begin(file, mapping, pos, len, flags, pagep,
783 fsdata);
784 }
785
786 static int exofs_write_end(struct file *file, struct address_space *mapping,
787 loff_t pos, unsigned len, unsigned copied,
788 struct page *page, void *fsdata)
789 {
790 struct inode *inode = mapping->host;
791 /* According to comment in simple_write_end i_mutex is held */
792 loff_t i_size = inode->i_size;
793 int ret;
794
795 ret = simple_write_end(file, mapping,pos, len, copied, page, fsdata);
796 if (unlikely(ret))
797 _write_failed(inode, pos + len);
798
799 /* TODO: once simple_write_end marks inode dirty remove */
800 if (i_size != inode->i_size)
801 mark_inode_dirty(inode);
802 return ret;
803 }
804
805 static int exofs_releasepage(struct page *page, gfp_t gfp)
806 {
807 EXOFS_DBGMSG("page 0x%lx\n", page->index);
808 WARN_ON(1);
809 return 0;
810 }
811
812 static void exofs_invalidatepage(struct page *page, unsigned long offset)
813 {
814 EXOFS_DBGMSG("page 0x%lx offset 0x%lx\n", page->index, offset);
815 WARN_ON(1);
816 }
817
818 const struct address_space_operations exofs_aops = {
819 .readpage = exofs_readpage,
820 .readpages = exofs_readpages,
821 .writepage = exofs_writepage,
822 .writepages = exofs_writepages,
823 .write_begin = exofs_write_begin_export,
824 .write_end = exofs_write_end,
825 .releasepage = exofs_releasepage,
826 .set_page_dirty = __set_page_dirty_nobuffers,
827 .invalidatepage = exofs_invalidatepage,
828
829 /* Not implemented Yet */
830 .bmap = NULL, /* TODO: use osd's OSD_ACT_READ_MAP */
831 .direct_IO = NULL, /* TODO: Should be trivial to do */
832
833 /* With these NULL has special meaning or default is not exported */
834 .get_xip_mem = NULL,
835 .migratepage = NULL,
836 .launder_page = NULL,
837 .is_partially_uptodate = NULL,
838 .error_remove_page = NULL,
839 };
840
841 /******************************************************************************
842 * INODE OPERATIONS
843 *****************************************************************************/
844
845 /*
846 * Test whether an inode is a fast symlink.
847 */
848 static inline int exofs_inode_is_fast_symlink(struct inode *inode)
849 {
850 struct exofs_i_info *oi = exofs_i(inode);
851
852 return S_ISLNK(inode->i_mode) && (oi->i_data[0] != 0);
853 }
854
855 const struct osd_attr g_attr_logical_length = ATTR_DEF(
856 OSD_APAGE_OBJECT_INFORMATION, OSD_ATTR_OI_LOGICAL_LENGTH, 8);
857
858 static int _do_truncate(struct inode *inode, loff_t newsize)
859 {
860 struct exofs_i_info *oi = exofs_i(inode);
861 int ret;
862
863 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
864
865 ret = exofs_oi_truncate(oi, (u64)newsize);
866 if (likely(!ret))
867 truncate_setsize(inode, newsize);
868
869 EXOFS_DBGMSG("(0x%lx) size=0x%llx ret=>%d\n",
870 inode->i_ino, newsize, ret);
871 return ret;
872 }
873
874 /*
875 * Set inode attributes - update size attribute on OSD if needed,
876 * otherwise just call generic functions.
877 */
878 int exofs_setattr(struct dentry *dentry, struct iattr *iattr)
879 {
880 struct inode *inode = dentry->d_inode;
881 int error;
882
883 /* if we are about to modify an object, and it hasn't been
884 * created yet, wait
885 */
886 error = wait_obj_created(exofs_i(inode));
887 if (unlikely(error))
888 return error;
889
890 error = inode_change_ok(inode, iattr);
891 if (unlikely(error))
892 return error;
893
894 if ((iattr->ia_valid & ATTR_SIZE) &&
895 iattr->ia_size != i_size_read(inode)) {
896 error = _do_truncate(inode, iattr->ia_size);
897 if (unlikely(error))
898 return error;
899 }
900
901 setattr_copy(inode, iattr);
902 mark_inode_dirty(inode);
903 return 0;
904 }
905
906 static const struct osd_attr g_attr_inode_file_layout = ATTR_DEF(
907 EXOFS_APAGE_FS_DATA,
908 EXOFS_ATTR_INODE_FILE_LAYOUT,
909 0);
910 static const struct osd_attr g_attr_inode_dir_layout = ATTR_DEF(
911 EXOFS_APAGE_FS_DATA,
912 EXOFS_ATTR_INODE_DIR_LAYOUT,
913 0);
914
915 /*
916 * Read the Linux inode info from the OSD, and return it as is. In exofs the
917 * inode info is in an application specific page/attribute of the osd-object.
918 */
919 static int exofs_get_inode(struct super_block *sb, struct exofs_i_info *oi,
920 struct exofs_fcb *inode)
921 {
922 struct exofs_sb_info *sbi = sb->s_fs_info;
923 struct osd_attr attrs[] = {
924 [0] = g_attr_inode_data,
925 [1] = g_attr_inode_file_layout,
926 [2] = g_attr_inode_dir_layout,
927 };
928 struct exofs_io_state *ios;
929 struct exofs_on_disk_inode_layout *layout;
930 int ret;
931
932 ret = exofs_get_io_state(&sbi->layout, &ios);
933 if (unlikely(ret)) {
934 EXOFS_ERR("%s: exofs_get_io_state failed.\n", __func__);
935 return ret;
936 }
937
938 ios->obj.id = exofs_oi_objno(oi);
939 exofs_make_credential(oi->i_cred, &ios->obj);
940 ios->cred = oi->i_cred;
941
942 attrs[1].len = exofs_on_disk_inode_layout_size(sbi->layout.s_numdevs);
943 attrs[2].len = exofs_on_disk_inode_layout_size(sbi->layout.s_numdevs);
944
945 ios->in_attr = attrs;
946 ios->in_attr_len = ARRAY_SIZE(attrs);
947
948 ret = exofs_sbi_read(ios);
949 if (unlikely(ret)) {
950 EXOFS_ERR("object(0x%llx) corrupted, return empty file=>%d\n",
951 _LLU(ios->obj.id), ret);
952 memset(inode, 0, sizeof(*inode));
953 inode->i_mode = 0040000 | (0777 & ~022);
954 /* If object is lost on target we might as well enable it's
955 * delete.
956 */
957 if ((ret == -ENOENT) || (ret == -EINVAL))
958 ret = 0;
959 goto out;
960 }
961
962 ret = extract_attr_from_ios(ios, &attrs[0]);
963 if (ret) {
964 EXOFS_ERR("%s: extract_attr of inode_data failed\n", __func__);
965 goto out;
966 }
967 WARN_ON(attrs[0].len != EXOFS_INO_ATTR_SIZE);
968 memcpy(inode, attrs[0].val_ptr, EXOFS_INO_ATTR_SIZE);
969
970 ret = extract_attr_from_ios(ios, &attrs[1]);
971 if (ret) {
972 EXOFS_ERR("%s: extract_attr of inode_data failed\n", __func__);
973 goto out;
974 }
975 if (attrs[1].len) {
976 layout = attrs[1].val_ptr;
977 if (layout->gen_func != cpu_to_le16(LAYOUT_MOVING_WINDOW)) {
978 EXOFS_ERR("%s: unsupported files layout %d\n",
979 __func__, layout->gen_func);
980 ret = -ENOTSUPP;
981 goto out;
982 }
983 }
984
985 ret = extract_attr_from_ios(ios, &attrs[2]);
986 if (ret) {
987 EXOFS_ERR("%s: extract_attr of inode_data failed\n", __func__);
988 goto out;
989 }
990 if (attrs[2].len) {
991 layout = attrs[2].val_ptr;
992 if (layout->gen_func != cpu_to_le16(LAYOUT_MOVING_WINDOW)) {
993 EXOFS_ERR("%s: unsupported meta-data layout %d\n",
994 __func__, layout->gen_func);
995 ret = -ENOTSUPP;
996 goto out;
997 }
998 }
999
1000 out:
1001 exofs_put_io_state(ios);
1002 return ret;
1003 }
1004
1005 static void __oi_init(struct exofs_i_info *oi)
1006 {
1007 init_waitqueue_head(&oi->i_wq);
1008 oi->i_flags = 0;
1009 }
1010 /*
1011 * Fill in an inode read from the OSD and set it up for use
1012 */
1013 struct inode *exofs_iget(struct super_block *sb, unsigned long ino)
1014 {
1015 struct exofs_i_info *oi;
1016 struct exofs_fcb fcb;
1017 struct inode *inode;
1018 int ret;
1019
1020 inode = iget_locked(sb, ino);
1021 if (!inode)
1022 return ERR_PTR(-ENOMEM);
1023 if (!(inode->i_state & I_NEW))
1024 return inode;
1025 oi = exofs_i(inode);
1026 __oi_init(oi);
1027
1028 /* read the inode from the osd */
1029 ret = exofs_get_inode(sb, oi, &fcb);
1030 if (ret)
1031 goto bad_inode;
1032
1033 set_obj_created(oi);
1034
1035 /* copy stuff from on-disk struct to in-memory struct */
1036 inode->i_mode = le16_to_cpu(fcb.i_mode);
1037 inode->i_uid = le32_to_cpu(fcb.i_uid);
1038 inode->i_gid = le32_to_cpu(fcb.i_gid);
1039 inode->i_nlink = le16_to_cpu(fcb.i_links_count);
1040 inode->i_ctime.tv_sec = (signed)le32_to_cpu(fcb.i_ctime);
1041 inode->i_atime.tv_sec = (signed)le32_to_cpu(fcb.i_atime);
1042 inode->i_mtime.tv_sec = (signed)le32_to_cpu(fcb.i_mtime);
1043 inode->i_ctime.tv_nsec =
1044 inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = 0;
1045 oi->i_commit_size = le64_to_cpu(fcb.i_size);
1046 i_size_write(inode, oi->i_commit_size);
1047 inode->i_blkbits = EXOFS_BLKSHIFT;
1048 inode->i_generation = le32_to_cpu(fcb.i_generation);
1049
1050 oi->i_dir_start_lookup = 0;
1051
1052 if ((inode->i_nlink == 0) && (inode->i_mode == 0)) {
1053 ret = -ESTALE;
1054 goto bad_inode;
1055 }
1056
1057 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
1058 if (fcb.i_data[0])
1059 inode->i_rdev =
1060 old_decode_dev(le32_to_cpu(fcb.i_data[0]));
1061 else
1062 inode->i_rdev =
1063 new_decode_dev(le32_to_cpu(fcb.i_data[1]));
1064 } else {
1065 memcpy(oi->i_data, fcb.i_data, sizeof(fcb.i_data));
1066 }
1067
1068 inode->i_mapping->backing_dev_info = sb->s_bdi;
1069 if (S_ISREG(inode->i_mode)) {
1070 inode->i_op = &exofs_file_inode_operations;
1071 inode->i_fop = &exofs_file_operations;
1072 inode->i_mapping->a_ops = &exofs_aops;
1073 } else if (S_ISDIR(inode->i_mode)) {
1074 inode->i_op = &exofs_dir_inode_operations;
1075 inode->i_fop = &exofs_dir_operations;
1076 inode->i_mapping->a_ops = &exofs_aops;
1077 } else if (S_ISLNK(inode->i_mode)) {
1078 if (exofs_inode_is_fast_symlink(inode))
1079 inode->i_op = &exofs_fast_symlink_inode_operations;
1080 else {
1081 inode->i_op = &exofs_symlink_inode_operations;
1082 inode->i_mapping->a_ops = &exofs_aops;
1083 }
1084 } else {
1085 inode->i_op = &exofs_special_inode_operations;
1086 if (fcb.i_data[0])
1087 init_special_inode(inode, inode->i_mode,
1088 old_decode_dev(le32_to_cpu(fcb.i_data[0])));
1089 else
1090 init_special_inode(inode, inode->i_mode,
1091 new_decode_dev(le32_to_cpu(fcb.i_data[1])));
1092 }
1093
1094 unlock_new_inode(inode);
1095 return inode;
1096
1097 bad_inode:
1098 iget_failed(inode);
1099 return ERR_PTR(ret);
1100 }
1101
1102 int __exofs_wait_obj_created(struct exofs_i_info *oi)
1103 {
1104 if (!obj_created(oi)) {
1105 EXOFS_DBGMSG("!obj_created\n");
1106 BUG_ON(!obj_2bcreated(oi));
1107 wait_event(oi->i_wq, obj_created(oi));
1108 EXOFS_DBGMSG("wait_event done\n");
1109 }
1110 return unlikely(is_bad_inode(&oi->vfs_inode)) ? -EIO : 0;
1111 }
1112
1113 /*
1114 * Callback function from exofs_new_inode(). The important thing is that we
1115 * set the obj_created flag so that other methods know that the object exists on
1116 * the OSD.
1117 */
1118 static void create_done(struct exofs_io_state *ios, void *p)
1119 {
1120 struct inode *inode = p;
1121 struct exofs_i_info *oi = exofs_i(inode);
1122 struct exofs_sb_info *sbi = inode->i_sb->s_fs_info;
1123 int ret;
1124
1125 ret = exofs_check_io(ios, NULL);
1126 exofs_put_io_state(ios);
1127
1128 atomic_dec(&sbi->s_curr_pending);
1129
1130 if (unlikely(ret)) {
1131 EXOFS_ERR("object=0x%llx creation failed in pid=0x%llx",
1132 _LLU(exofs_oi_objno(oi)), _LLU(sbi->layout.s_pid));
1133 /*TODO: When FS is corrupted creation can fail, object already
1134 * exist. Get rid of this asynchronous creation, if exist
1135 * increment the obj counter and try the next object. Until we
1136 * succeed. All these dangling objects will be made into lost
1137 * files by chkfs.exofs
1138 */
1139 }
1140
1141 set_obj_created(oi);
1142
1143 wake_up(&oi->i_wq);
1144 }
1145
1146 /*
1147 * Set up a new inode and create an object for it on the OSD
1148 */
1149 struct inode *exofs_new_inode(struct inode *dir, int mode)
1150 {
1151 struct super_block *sb;
1152 struct inode *inode;
1153 struct exofs_i_info *oi;
1154 struct exofs_sb_info *sbi;
1155 struct exofs_io_state *ios;
1156 int ret;
1157
1158 sb = dir->i_sb;
1159 inode = new_inode(sb);
1160 if (!inode)
1161 return ERR_PTR(-ENOMEM);
1162
1163 oi = exofs_i(inode);
1164 __oi_init(oi);
1165
1166 set_obj_2bcreated(oi);
1167
1168 sbi = sb->s_fs_info;
1169
1170 inode->i_mapping->backing_dev_info = sb->s_bdi;
1171 inode_init_owner(inode, dir, mode);
1172 inode->i_ino = sbi->s_nextid++;
1173 inode->i_blkbits = EXOFS_BLKSHIFT;
1174 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1175 oi->i_commit_size = inode->i_size = 0;
1176 spin_lock(&sbi->s_next_gen_lock);
1177 inode->i_generation = sbi->s_next_generation++;
1178 spin_unlock(&sbi->s_next_gen_lock);
1179 insert_inode_hash(inode);
1180
1181 exofs_sbi_write_stats(sbi); /* Make sure new sbi->s_nextid is on disk */
1182
1183 mark_inode_dirty(inode);
1184
1185 ret = exofs_get_io_state(&sbi->layout, &ios);
1186 if (unlikely(ret)) {
1187 EXOFS_ERR("exofs_new_inode: exofs_get_io_state failed\n");
1188 return ERR_PTR(ret);
1189 }
1190
1191 ios->obj.id = exofs_oi_objno(oi);
1192 exofs_make_credential(oi->i_cred, &ios->obj);
1193
1194 ios->done = create_done;
1195 ios->private = inode;
1196 ios->cred = oi->i_cred;
1197 ret = exofs_sbi_create(ios);
1198 if (ret) {
1199 exofs_put_io_state(ios);
1200 return ERR_PTR(ret);
1201 }
1202 atomic_inc(&sbi->s_curr_pending);
1203
1204 return inode;
1205 }
1206
1207 /*
1208 * struct to pass two arguments to update_inode's callback
1209 */
1210 struct updatei_args {
1211 struct exofs_sb_info *sbi;
1212 struct exofs_fcb fcb;
1213 };
1214
1215 /*
1216 * Callback function from exofs_update_inode().
1217 */
1218 static void updatei_done(struct exofs_io_state *ios, void *p)
1219 {
1220 struct updatei_args *args = p;
1221
1222 exofs_put_io_state(ios);
1223
1224 atomic_dec(&args->sbi->s_curr_pending);
1225
1226 kfree(args);
1227 }
1228
1229 /*
1230 * Write the inode to the OSD. Just fill up the struct, and set the attribute
1231 * synchronously or asynchronously depending on the do_sync flag.
1232 */
1233 static int exofs_update_inode(struct inode *inode, int do_sync)
1234 {
1235 struct exofs_i_info *oi = exofs_i(inode);
1236 struct super_block *sb = inode->i_sb;
1237 struct exofs_sb_info *sbi = sb->s_fs_info;
1238 struct exofs_io_state *ios;
1239 struct osd_attr attr;
1240 struct exofs_fcb *fcb;
1241 struct updatei_args *args;
1242 int ret;
1243
1244 args = kzalloc(sizeof(*args), GFP_KERNEL);
1245 if (!args) {
1246 EXOFS_DBGMSG("Failed kzalloc of args\n");
1247 return -ENOMEM;
1248 }
1249
1250 fcb = &args->fcb;
1251
1252 fcb->i_mode = cpu_to_le16(inode->i_mode);
1253 fcb->i_uid = cpu_to_le32(inode->i_uid);
1254 fcb->i_gid = cpu_to_le32(inode->i_gid);
1255 fcb->i_links_count = cpu_to_le16(inode->i_nlink);
1256 fcb->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
1257 fcb->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
1258 fcb->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
1259 oi->i_commit_size = i_size_read(inode);
1260 fcb->i_size = cpu_to_le64(oi->i_commit_size);
1261 fcb->i_generation = cpu_to_le32(inode->i_generation);
1262
1263 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
1264 if (old_valid_dev(inode->i_rdev)) {
1265 fcb->i_data[0] =
1266 cpu_to_le32(old_encode_dev(inode->i_rdev));
1267 fcb->i_data[1] = 0;
1268 } else {
1269 fcb->i_data[0] = 0;
1270 fcb->i_data[1] =
1271 cpu_to_le32(new_encode_dev(inode->i_rdev));
1272 fcb->i_data[2] = 0;
1273 }
1274 } else
1275 memcpy(fcb->i_data, oi->i_data, sizeof(fcb->i_data));
1276
1277 ret = exofs_get_io_state(&sbi->layout, &ios);
1278 if (unlikely(ret)) {
1279 EXOFS_ERR("%s: exofs_get_io_state failed.\n", __func__);
1280 goto free_args;
1281 }
1282
1283 attr = g_attr_inode_data;
1284 attr.val_ptr = fcb;
1285 ios->out_attr_len = 1;
1286 ios->out_attr = &attr;
1287
1288 wait_obj_created(oi);
1289
1290 if (!do_sync) {
1291 args->sbi = sbi;
1292 ios->done = updatei_done;
1293 ios->private = args;
1294 }
1295
1296 ret = exofs_oi_write(oi, ios);
1297 if (!do_sync && !ret) {
1298 atomic_inc(&sbi->s_curr_pending);
1299 goto out; /* deallocation in updatei_done */
1300 }
1301
1302 exofs_put_io_state(ios);
1303 free_args:
1304 kfree(args);
1305 out:
1306 EXOFS_DBGMSG("(0x%lx) do_sync=%d ret=>%d\n",
1307 inode->i_ino, do_sync, ret);
1308 return ret;
1309 }
1310
1311 int exofs_write_inode(struct inode *inode, struct writeback_control *wbc)
1312 {
1313 /* FIXME: fix fsync and use wbc->sync_mode == WB_SYNC_ALL */
1314 return exofs_update_inode(inode, 1);
1315 }
1316
1317 /*
1318 * Callback function from exofs_delete_inode() - don't have much cleaning up to
1319 * do.
1320 */
1321 static void delete_done(struct exofs_io_state *ios, void *p)
1322 {
1323 struct exofs_sb_info *sbi = p;
1324
1325 exofs_put_io_state(ios);
1326
1327 atomic_dec(&sbi->s_curr_pending);
1328 }
1329
1330 /*
1331 * Called when the refcount of an inode reaches zero. We remove the object
1332 * from the OSD here. We make sure the object was created before we try and
1333 * delete it.
1334 */
1335 void exofs_evict_inode(struct inode *inode)
1336 {
1337 struct exofs_i_info *oi = exofs_i(inode);
1338 struct super_block *sb = inode->i_sb;
1339 struct exofs_sb_info *sbi = sb->s_fs_info;
1340 struct exofs_io_state *ios;
1341 int ret;
1342
1343 truncate_inode_pages(&inode->i_data, 0);
1344
1345 /* TODO: should do better here */
1346 if (inode->i_nlink || is_bad_inode(inode))
1347 goto no_delete;
1348
1349 inode->i_size = 0;
1350 end_writeback(inode);
1351
1352 /* if we are deleting an obj that hasn't been created yet, wait.
1353 * This also makes sure that create_done cannot be called with an
1354 * already evicted inode.
1355 */
1356 wait_obj_created(oi);
1357 /* ignore the error, attempt a remove anyway */
1358
1359 /* Now Remove the OSD objects */
1360 ret = exofs_get_io_state(&sbi->layout, &ios);
1361 if (unlikely(ret)) {
1362 EXOFS_ERR("%s: exofs_get_io_state failed\n", __func__);
1363 return;
1364 }
1365
1366 ios->obj.id = exofs_oi_objno(oi);
1367 ios->done = delete_done;
1368 ios->private = sbi;
1369 ios->cred = oi->i_cred;
1370 ret = exofs_sbi_remove(ios);
1371 if (ret) {
1372 EXOFS_ERR("%s: exofs_sbi_remove failed\n", __func__);
1373 exofs_put_io_state(ios);
1374 return;
1375 }
1376 atomic_inc(&sbi->s_curr_pending);
1377
1378 return;
1379
1380 no_delete:
1381 end_writeback(inode);
1382 }
Linux kernel - Deliverables
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