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exofs: Optimize read_4_write
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / exofs / inode.c
blobc8f58a96e5978ed4d332cfa474948c8808180510
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) empty page len=%zx "
354 "read_4_write=%d index=0x%lx end_index=0x%lx "
355 "splitting\n", inode->i_ino, len,
356 pcol->read_4_write, page->index, end_index);
357
358 return read_exec(pcol);
359 }
360
361 try_again:
362
363 if (unlikely(pcol->pg_first == -1)) {
364 pcol->pg_first = page->index;
365 } else if (unlikely((pcol->pg_first + pcol->nr_pages) !=
366 page->index)) {
367 /* Discontinuity detected, split the request */
368 ret = read_exec(pcol);
369 if (unlikely(ret))
370 goto fail;
371 goto try_again;
372 }
373
374 if (!pcol->pages) {
375 ret = pcol_try_alloc(pcol);
376 if (unlikely(ret))
377 goto fail;
378 }
379
380 if (len != PAGE_CACHE_SIZE)
381 zero_user(page, len, PAGE_CACHE_SIZE - len);
382
383 EXOFS_DBGMSG2(" readpage_strip(0x%lx, 0x%lx) len=0x%zx\n",
384 inode->i_ino, page->index, len);
385
386 ret = pcol_add_page(pcol, page, len);
387 if (ret) {
388 EXOFS_DBGMSG2("Failed pcol_add_page pages[i]=%p "
389 "this_len=0x%zx nr_pages=%u length=0x%lx\n",
390 page, len, pcol->nr_pages, pcol->length);
391
392 /* split the request, and start again with current page */
393 ret = read_exec(pcol);
394 if (unlikely(ret))
395 goto fail;
396
397 goto try_again;
398 }
399
400 return 0;
401
402 fail:
403 /* SetPageError(page); ??? */
404 unlock_page(page);
405 return ret;
406 }
407
408 static int exofs_readpages(struct file *file, struct address_space *mapping,
409 struct list_head *pages, unsigned nr_pages)
410 {
411 struct page_collect pcol;
412 int ret;
413
414 _pcol_init(&pcol, nr_pages, mapping->host);
415
416 ret = read_cache_pages(mapping, pages, readpage_strip, &pcol);
417 if (ret) {
418 EXOFS_ERR("read_cache_pages => %d\n", ret);
419 return ret;
420 }
421
422 return read_exec(&pcol);
423 }
424
425 static int _readpage(struct page *page, bool read_4_write)
426 {
427 struct page_collect pcol;
428 int ret;
429
430 _pcol_init(&pcol, 1, page->mapping->host);
431
432 pcol.read_4_write = read_4_write;
433 ret = readpage_strip(&pcol, page);
434 if (ret) {
435 EXOFS_ERR("_readpage => %d\n", ret);
436 return ret;
437 }
438
439 return read_exec(&pcol);
440 }
441
442 /*
443 * We don't need the file
444 */
445 static int exofs_readpage(struct file *file, struct page *page)
446 {
447 return _readpage(page, false);
448 }
449
450 /* Callback for osd_write. All writes are asynchronous */
451 static void writepages_done(struct exofs_io_state *ios, void *p)
452 {
453 struct page_collect *pcol = p;
454 int i;
455 u64 resid;
456 u64 good_bytes;
457 u64 length = 0;
458 int ret = exofs_check_io(ios, &resid);
459
460 atomic_dec(&pcol->sbi->s_curr_pending);
461
462 if (likely(!ret))
463 good_bytes = pcol->length;
464 else
465 good_bytes = pcol->length - resid;
466
467 EXOFS_DBGMSG2("writepages_done(0x%lx) good_bytes=0x%llx"
468 " length=0x%lx nr_pages=%u\n",
469 pcol->inode->i_ino, _LLU(good_bytes), pcol->length,
470 pcol->nr_pages);
471
472 for (i = 0; i < pcol->nr_pages; i++) {
473 struct page *page = pcol->pages[i];
474 struct inode *inode = page->mapping->host;
475 int page_stat;
476
477 if (inode != pcol->inode)
478 continue; /* osd might add more pages to a bio */
479
480 if (likely(length < good_bytes))
481 page_stat = 0;
482 else
483 page_stat = ret;
484
485 update_write_page(page, page_stat);
486 unlock_page(page);
487 EXOFS_DBGMSG2(" writepages_done(0x%lx, 0x%lx) status=%d\n",
488 inode->i_ino, page->index, page_stat);
489
490 length += PAGE_SIZE;
491 }
492
493 pcol_free(pcol);
494 kfree(pcol);
495 EXOFS_DBGMSG2("writepages_done END\n");
496 }
497
498 static int write_exec(struct page_collect *pcol)
499 {
500 struct exofs_i_info *oi = exofs_i(pcol->inode);
501 struct exofs_io_state *ios = pcol->ios;
502 struct page_collect *pcol_copy = NULL;
503 int ret;
504
505 if (!pcol->pages)
506 return 0;
507
508 pcol_copy = kmalloc(sizeof(*pcol_copy), GFP_KERNEL);
509 if (!pcol_copy) {
510 EXOFS_ERR("write_exec: Failed to kmalloc(pcol)\n");
511 ret = -ENOMEM;
512 goto err;
513 }
514
515 *pcol_copy = *pcol;
516
517 ios->pages = pcol_copy->pages;
518 ios->nr_pages = pcol_copy->nr_pages;
519 ios->offset = pcol_copy->pg_first << PAGE_CACHE_SHIFT;
520 ios->length = pcol_copy->length;
521 ios->done = writepages_done;
522 ios->private = pcol_copy;
523
524 ret = exofs_oi_write(oi, ios);
525 if (unlikely(ret)) {
526 EXOFS_ERR("write_exec: exofs_oi_write() Failed\n");
527 goto err;
528 }
529
530 atomic_inc(&pcol->sbi->s_curr_pending);
531 EXOFS_DBGMSG2("write_exec(0x%lx, 0x%llx) start=0x%llx length=0x%lx\n",
532 pcol->inode->i_ino, pcol->pg_first, _LLU(ios->offset),
533 pcol->length);
534 /* pages ownership was passed to pcol_copy */
535 _pcol_reset(pcol);
536 return 0;
537
538 err:
539 _unlock_pcol_pages(pcol, ret, WRITE);
540 pcol_free(pcol);
541 kfree(pcol_copy);
542
543 return ret;
544 }
545
546 /* writepage_strip is called either directly from writepage() or by the VFS from
547 * within write_cache_pages(), to add one more page to be written to storage.
548 * It will try to collect as many contiguous pages as possible. If a
549 * discontinuity is encountered or it runs out of resources it will submit the
550 * previous segment and will start a new collection.
551 * Eventually caller must submit the last segment if present.
552 */
553 static int writepage_strip(struct page *page,
554 struct writeback_control *wbc_unused, void *data)
555 {
556 struct page_collect *pcol = data;
557 struct inode *inode = pcol->inode;
558 struct exofs_i_info *oi = exofs_i(inode);
559 loff_t i_size = i_size_read(inode);
560 pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
561 size_t len;
562 int ret;
563
564 BUG_ON(!PageLocked(page));
565
566 ret = wait_obj_created(oi);
567 if (unlikely(ret))
568 goto fail;
569
570 if (page->index < end_index)
571 /* in this case, the page is within the limits of the file */
572 len = PAGE_CACHE_SIZE;
573 else {
574 len = i_size & ~PAGE_CACHE_MASK;
575
576 if (page->index > end_index || !len) {
577 /* in this case, the page is outside the limits
578 * (truncate in progress)
579 */
580 ret = write_exec(pcol);
581 if (unlikely(ret))
582 goto fail;
583 if (PageError(page))
584 ClearPageError(page);
585 unlock_page(page);
586 EXOFS_DBGMSG("writepage_strip(0x%lx, 0x%lx) "
587 "outside the limits\n",
588 inode->i_ino, page->index);
589 return 0;
590 }
591 }
592
593 try_again:
594
595 if (unlikely(pcol->pg_first == -1)) {
596 pcol->pg_first = page->index;
597 } else if (unlikely((pcol->pg_first + pcol->nr_pages) !=
598 page->index)) {
599 /* Discontinuity detected, split the request */
600 ret = write_exec(pcol);
601 if (unlikely(ret))
602 goto fail;
603
604 EXOFS_DBGMSG("writepage_strip(0x%lx, 0x%lx) Discontinuity\n",
605 inode->i_ino, page->index);
606 goto try_again;
607 }
608
609 if (!pcol->pages) {
610 ret = pcol_try_alloc(pcol);
611 if (unlikely(ret))
612 goto fail;
613 }
614
615 EXOFS_DBGMSG2(" writepage_strip(0x%lx, 0x%lx) len=0x%zx\n",
616 inode->i_ino, page->index, len);
617
618 ret = pcol_add_page(pcol, page, len);
619 if (unlikely(ret)) {
620 EXOFS_DBGMSG2("Failed pcol_add_page "
621 "nr_pages=%u total_length=0x%lx\n",
622 pcol->nr_pages, pcol->length);
623
624 /* split the request, next loop will start again */
625 ret = write_exec(pcol);
626 if (unlikely(ret)) {
627 EXOFS_DBGMSG("write_exec failed => %d", ret);
628 goto fail;
629 }
630
631 goto try_again;
632 }
633
634 BUG_ON(PageWriteback(page));
635 set_page_writeback(page);
636
637 return 0;
638
639 fail:
640 EXOFS_DBGMSG("Error: writepage_strip(0x%lx, 0x%lx)=>%d\n",
641 inode->i_ino, page->index, ret);
642 set_bit(AS_EIO, &page->mapping->flags);
643 unlock_page(page);
644 return ret;
645 }
646
647 static int exofs_writepages(struct address_space *mapping,
648 struct writeback_control *wbc)
649 {
650 struct page_collect pcol;
651 long start, end, expected_pages;
652 int ret;
653
654 start = wbc->range_start >> PAGE_CACHE_SHIFT;
655 end = (wbc->range_end == LLONG_MAX) ?
656 start + mapping->nrpages :
657 wbc->range_end >> PAGE_CACHE_SHIFT;
658
659 if (start || end)
660 expected_pages = end - start + 1;
661 else
662 expected_pages = mapping->nrpages;
663
664 if (expected_pages < 32L)
665 expected_pages = 32L;
666
667 EXOFS_DBGMSG2("inode(0x%lx) wbc->start=0x%llx wbc->end=0x%llx "
668 "nrpages=%lu start=0x%lx end=0x%lx expected_pages=%ld\n",
669 mapping->host->i_ino, wbc->range_start, wbc->range_end,
670 mapping->nrpages, start, end, expected_pages);
671
672 _pcol_init(&pcol, expected_pages, mapping->host);
673
674 ret = write_cache_pages(mapping, wbc, writepage_strip, &pcol);
675 if (ret) {
676 EXOFS_ERR("write_cache_pages => %d\n", ret);
677 return ret;
678 }
679
680 return write_exec(&pcol);
681 }
682
683 static int exofs_writepage(struct page *page, struct writeback_control *wbc)
684 {
685 struct page_collect pcol;
686 int ret;
687
688 _pcol_init(&pcol, 1, page->mapping->host);
689
690 ret = writepage_strip(page, NULL, &pcol);
691 if (ret) {
692 EXOFS_ERR("exofs_writepage => %d\n", ret);
693 return ret;
694 }
695
696 return write_exec(&pcol);
697 }
698
699 /* i_mutex held using inode->i_size directly */
700 static void _write_failed(struct inode *inode, loff_t to)
701 {
702 if (to > inode->i_size)
703 truncate_pagecache(inode, to, inode->i_size);
704 }
705
706 int exofs_write_begin(struct file *file, struct address_space *mapping,
707 loff_t pos, unsigned len, unsigned flags,
708 struct page **pagep, void **fsdata)
709 {
710 int ret = 0;
711 struct page *page;
712
713 page = *pagep;
714 if (page == NULL) {
715 ret = simple_write_begin(file, mapping, pos, len, flags, pagep,
716 fsdata);
717 if (ret) {
718 EXOFS_DBGMSG("simple_write_begin failed\n");
719 goto out;
720 }
721
722 page = *pagep;
723 }
724
725 /* read modify write */
726 if (!PageUptodate(page) && (len != PAGE_CACHE_SIZE)) {
727 loff_t i_size = i_size_read(mapping->host);
728 pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
729 size_t rlen;
730
731 if (page->index < end_index)
732 rlen = PAGE_CACHE_SIZE;
733 else if (page->index == end_index)
734 rlen = i_size & ~PAGE_CACHE_MASK;
735 else
736 rlen = 0;
737
738 if (!rlen) {
739 clear_highpage(page);
740 SetPageUptodate(page);
741 goto out;
742 }
743
744 ret = _readpage(page, true);
745 if (ret) {
746 /*SetPageError was done by _readpage. Is it ok?*/
747 unlock_page(page);
748 EXOFS_DBGMSG("__readpage failed\n");
749 }
750 }
751 out:
752 if (unlikely(ret))
753 _write_failed(mapping->host, pos + len);
754
755 return ret;
756 }
757
758 static int exofs_write_begin_export(struct file *file,
759 struct address_space *mapping,
760 loff_t pos, unsigned len, unsigned flags,
761 struct page **pagep, void **fsdata)
762 {
763 *pagep = NULL;
764
765 return exofs_write_begin(file, mapping, pos, len, flags, pagep,
766 fsdata);
767 }
768
769 static int exofs_write_end(struct file *file, struct address_space *mapping,
770 loff_t pos, unsigned len, unsigned copied,
771 struct page *page, void *fsdata)
772 {
773 struct inode *inode = mapping->host;
774 /* According to comment in simple_write_end i_mutex is held */
775 loff_t i_size = inode->i_size;
776 int ret;
777
778 ret = simple_write_end(file, mapping,pos, len, copied, page, fsdata);
779 if (unlikely(ret))
780 _write_failed(inode, pos + len);
781
782 /* TODO: once simple_write_end marks inode dirty remove */
783 if (i_size != inode->i_size)
784 mark_inode_dirty(inode);
785 return ret;
786 }
787
788 static int exofs_releasepage(struct page *page, gfp_t gfp)
789 {
790 EXOFS_DBGMSG("page 0x%lx\n", page->index);
791 WARN_ON(1);
792 return 0;
793 }
794
795 static void exofs_invalidatepage(struct page *page, unsigned long offset)
796 {
797 EXOFS_DBGMSG("page 0x%lx offset 0x%lx\n", page->index, offset);
798 WARN_ON(1);
799 }
800
801 const struct address_space_operations exofs_aops = {
802 .readpage = exofs_readpage,
803 .readpages = exofs_readpages,
804 .writepage = exofs_writepage,
805 .writepages = exofs_writepages,
806 .write_begin = exofs_write_begin_export,
807 .write_end = exofs_write_end,
808 .releasepage = exofs_releasepage,
809 .set_page_dirty = __set_page_dirty_nobuffers,
810 .invalidatepage = exofs_invalidatepage,
811
812 /* Not implemented Yet */
813 .bmap = NULL, /* TODO: use osd's OSD_ACT_READ_MAP */
814 .direct_IO = NULL, /* TODO: Should be trivial to do */
815
816 /* With these NULL has special meaning or default is not exported */
817 .sync_page = NULL,
818 .get_xip_mem = NULL,
819 .migratepage = NULL,
820 .launder_page = NULL,
821 .is_partially_uptodate = NULL,
822 .error_remove_page = NULL,
823 };
824
825 /******************************************************************************
826 * INODE OPERATIONS
827 *****************************************************************************/
828
829 /*
830 * Test whether an inode is a fast symlink.
831 */
832 static inline int exofs_inode_is_fast_symlink(struct inode *inode)
833 {
834 struct exofs_i_info *oi = exofs_i(inode);
835
836 return S_ISLNK(inode->i_mode) && (oi->i_data[0] != 0);
837 }
838
839 const struct osd_attr g_attr_logical_length = ATTR_DEF(
840 OSD_APAGE_OBJECT_INFORMATION, OSD_ATTR_OI_LOGICAL_LENGTH, 8);
841
842 static int _do_truncate(struct inode *inode, loff_t newsize)
843 {
844 struct exofs_i_info *oi = exofs_i(inode);
845 int ret;
846
847 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
848
849 ret = exofs_oi_truncate(oi, (u64)newsize);
850 if (likely(!ret))
851 truncate_setsize(inode, newsize);
852
853 EXOFS_DBGMSG("(0x%lx) size=0x%llx ret=>%d\n",
854 inode->i_ino, newsize, ret);
855 return ret;
856 }
857
858 /*
859 * Set inode attributes - update size attribute on OSD if needed,
860 * otherwise just call generic functions.
861 */
862 int exofs_setattr(struct dentry *dentry, struct iattr *iattr)
863 {
864 struct inode *inode = dentry->d_inode;
865 int error;
866
867 /* if we are about to modify an object, and it hasn't been
868 * created yet, wait
869 */
870 error = wait_obj_created(exofs_i(inode));
871 if (unlikely(error))
872 return error;
873
874 error = inode_change_ok(inode, iattr);
875 if (unlikely(error))
876 return error;
877
878 if ((iattr->ia_valid & ATTR_SIZE) &&
879 iattr->ia_size != i_size_read(inode)) {
880 error = _do_truncate(inode, iattr->ia_size);
881 if (unlikely(error))
882 return error;
883 }
884
885 setattr_copy(inode, iattr);
886 mark_inode_dirty(inode);
887 return 0;
888 }
889
890 static const struct osd_attr g_attr_inode_file_layout = ATTR_DEF(
891 EXOFS_APAGE_FS_DATA,
892 EXOFS_ATTR_INODE_FILE_LAYOUT,
893 0);
894 static const struct osd_attr g_attr_inode_dir_layout = ATTR_DEF(
895 EXOFS_APAGE_FS_DATA,
896 EXOFS_ATTR_INODE_DIR_LAYOUT,
897 0);
898
899 /*
900 * Read the Linux inode info from the OSD, and return it as is. In exofs the
901 * inode info is in an application specific page/attribute of the osd-object.
902 */
903 static int exofs_get_inode(struct super_block *sb, struct exofs_i_info *oi,
904 struct exofs_fcb *inode)
905 {
906 struct exofs_sb_info *sbi = sb->s_fs_info;
907 struct osd_attr attrs[] = {
908 [0] = g_attr_inode_data,
909 [1] = g_attr_inode_file_layout,
910 [2] = g_attr_inode_dir_layout,
911 };
912 struct exofs_io_state *ios;
913 struct exofs_on_disk_inode_layout *layout;
914 int ret;
915
916 ret = exofs_get_io_state(&sbi->layout, &ios);
917 if (unlikely(ret)) {
918 EXOFS_ERR("%s: exofs_get_io_state failed.\n", __func__);
919 return ret;
920 }
921
922 ios->obj.id = exofs_oi_objno(oi);
923 exofs_make_credential(oi->i_cred, &ios->obj);
924 ios->cred = oi->i_cred;
925
926 attrs[1].len = exofs_on_disk_inode_layout_size(sbi->layout.s_numdevs);
927 attrs[2].len = exofs_on_disk_inode_layout_size(sbi->layout.s_numdevs);
928
929 ios->in_attr = attrs;
930 ios->in_attr_len = ARRAY_SIZE(attrs);
931
932 ret = exofs_sbi_read(ios);
933 if (unlikely(ret)) {
934 EXOFS_ERR("object(0x%llx) corrupted, return empty file=>%d\n",
935 _LLU(ios->obj.id), ret);
936 memset(inode, 0, sizeof(*inode));
937 inode->i_mode = 0040000 | (0777 & ~022);
938 /* If object is lost on target we might as well enable it's
939 * delete.
940 */
941 if ((ret == -ENOENT) || (ret == -EINVAL))
942 ret = 0;
943 goto out;
944 }
945
946 ret = extract_attr_from_ios(ios, &attrs[0]);
947 if (ret) {
948 EXOFS_ERR("%s: extract_attr of inode_data failed\n", __func__);
949 goto out;
950 }
951 WARN_ON(attrs[0].len != EXOFS_INO_ATTR_SIZE);
952 memcpy(inode, attrs[0].val_ptr, EXOFS_INO_ATTR_SIZE);
953
954 ret = extract_attr_from_ios(ios, &attrs[1]);
955 if (ret) {
956 EXOFS_ERR("%s: extract_attr of inode_data failed\n", __func__);
957 goto out;
958 }
959 if (attrs[1].len) {
960 layout = attrs[1].val_ptr;
961 if (layout->gen_func != cpu_to_le16(LAYOUT_MOVING_WINDOW)) {
962 EXOFS_ERR("%s: unsupported files layout %d\n",
963 __func__, layout->gen_func);
964 ret = -ENOTSUPP;
965 goto out;
966 }
967 }
968
969 ret = extract_attr_from_ios(ios, &attrs[2]);
970 if (ret) {
971 EXOFS_ERR("%s: extract_attr of inode_data failed\n", __func__);
972 goto out;
973 }
974 if (attrs[2].len) {
975 layout = attrs[2].val_ptr;
976 if (layout->gen_func != cpu_to_le16(LAYOUT_MOVING_WINDOW)) {
977 EXOFS_ERR("%s: unsupported meta-data layout %d\n",
978 __func__, layout->gen_func);
979 ret = -ENOTSUPP;
980 goto out;
981 }
982 }
983
984 out:
985 exofs_put_io_state(ios);
986 return ret;
987 }
988
989 static void __oi_init(struct exofs_i_info *oi)
990 {
991 init_waitqueue_head(&oi->i_wq);
992 oi->i_flags = 0;
993 }
994 /*
995 * Fill in an inode read from the OSD and set it up for use
996 */
997 struct inode *exofs_iget(struct super_block *sb, unsigned long ino)
998 {
999 struct exofs_i_info *oi;
1000 struct exofs_fcb fcb;
1001 struct inode *inode;
1002 int ret;
1003
1004 inode = iget_locked(sb, ino);
1005 if (!inode)
1006 return ERR_PTR(-ENOMEM);
1007 if (!(inode->i_state & I_NEW))
1008 return inode;
1009 oi = exofs_i(inode);
1010 __oi_init(oi);
1011
1012 /* read the inode from the osd */
1013 ret = exofs_get_inode(sb, oi, &fcb);
1014 if (ret)
1015 goto bad_inode;
1016
1017 set_obj_created(oi);
1018
1019 /* copy stuff from on-disk struct to in-memory struct */
1020 inode->i_mode = le16_to_cpu(fcb.i_mode);
1021 inode->i_uid = le32_to_cpu(fcb.i_uid);
1022 inode->i_gid = le32_to_cpu(fcb.i_gid);
1023 inode->i_nlink = le16_to_cpu(fcb.i_links_count);
1024 inode->i_ctime.tv_sec = (signed)le32_to_cpu(fcb.i_ctime);
1025 inode->i_atime.tv_sec = (signed)le32_to_cpu(fcb.i_atime);
1026 inode->i_mtime.tv_sec = (signed)le32_to_cpu(fcb.i_mtime);
1027 inode->i_ctime.tv_nsec =
1028 inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = 0;
1029 oi->i_commit_size = le64_to_cpu(fcb.i_size);
1030 i_size_write(inode, oi->i_commit_size);
1031 inode->i_blkbits = EXOFS_BLKSHIFT;
1032 inode->i_generation = le32_to_cpu(fcb.i_generation);
1033
1034 oi->i_dir_start_lookup = 0;
1035
1036 if ((inode->i_nlink == 0) && (inode->i_mode == 0)) {
1037 ret = -ESTALE;
1038 goto bad_inode;
1039 }
1040
1041 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
1042 if (fcb.i_data[0])
1043 inode->i_rdev =
1044 old_decode_dev(le32_to_cpu(fcb.i_data[0]));
1045 else
1046 inode->i_rdev =
1047 new_decode_dev(le32_to_cpu(fcb.i_data[1]));
1048 } else {
1049 memcpy(oi->i_data, fcb.i_data, sizeof(fcb.i_data));
1050 }
1051
1052 if (S_ISREG(inode->i_mode)) {
1053 inode->i_op = &exofs_file_inode_operations;
1054 inode->i_fop = &exofs_file_operations;
1055 inode->i_mapping->a_ops = &exofs_aops;
1056 } else if (S_ISDIR(inode->i_mode)) {
1057 inode->i_op = &exofs_dir_inode_operations;
1058 inode->i_fop = &exofs_dir_operations;
1059 inode->i_mapping->a_ops = &exofs_aops;
1060 } else if (S_ISLNK(inode->i_mode)) {
1061 if (exofs_inode_is_fast_symlink(inode))
1062 inode->i_op = &exofs_fast_symlink_inode_operations;
1063 else {
1064 inode->i_op = &exofs_symlink_inode_operations;
1065 inode->i_mapping->a_ops = &exofs_aops;
1066 }
1067 } else {
1068 inode->i_op = &exofs_special_inode_operations;
1069 if (fcb.i_data[0])
1070 init_special_inode(inode, inode->i_mode,
1071 old_decode_dev(le32_to_cpu(fcb.i_data[0])));
1072 else
1073 init_special_inode(inode, inode->i_mode,
1074 new_decode_dev(le32_to_cpu(fcb.i_data[1])));
1075 }
1076
1077 unlock_new_inode(inode);
1078 return inode;
1079
1080 bad_inode:
1081 iget_failed(inode);
1082 return ERR_PTR(ret);
1083 }
1084
1085 int __exofs_wait_obj_created(struct exofs_i_info *oi)
1086 {
1087 if (!obj_created(oi)) {
1088 EXOFS_DBGMSG("!obj_created\n");
1089 BUG_ON(!obj_2bcreated(oi));
1090 wait_event(oi->i_wq, obj_created(oi));
1091 EXOFS_DBGMSG("wait_event done\n");
1092 }
1093 return unlikely(is_bad_inode(&oi->vfs_inode)) ? -EIO : 0;
1094 }
1095 /*
1096 * Callback function from exofs_new_inode(). The important thing is that we
1097 * set the obj_created flag so that other methods know that the object exists on
1098 * the OSD.
1099 */
1100 static void create_done(struct exofs_io_state *ios, void *p)
1101 {
1102 struct inode *inode = p;
1103 struct exofs_i_info *oi = exofs_i(inode);
1104 struct exofs_sb_info *sbi = inode->i_sb->s_fs_info;
1105 int ret;
1106
1107 ret = exofs_check_io(ios, NULL);
1108 exofs_put_io_state(ios);
1109
1110 atomic_dec(&sbi->s_curr_pending);
1111
1112 if (unlikely(ret)) {
1113 EXOFS_ERR("object=0x%llx creation failed in pid=0x%llx",
1114 _LLU(exofs_oi_objno(oi)), _LLU(sbi->layout.s_pid));
1115 /*TODO: When FS is corrupted creation can fail, object already
1116 * exist. Get rid of this asynchronous creation, if exist
1117 * increment the obj counter and try the next object. Until we
1118 * succeed. All these dangling objects will be made into lost
1119 * files by chkfs.exofs
1120 */
1121 }
1122
1123 set_obj_created(oi);
1124
1125 wake_up(&oi->i_wq);
1126 }
1127
1128 /*
1129 * Set up a new inode and create an object for it on the OSD
1130 */
1131 struct inode *exofs_new_inode(struct inode *dir, int mode)
1132 {
1133 struct super_block *sb;
1134 struct inode *inode;
1135 struct exofs_i_info *oi;
1136 struct exofs_sb_info *sbi;
1137 struct exofs_io_state *ios;
1138 int ret;
1139
1140 sb = dir->i_sb;
1141 inode = new_inode(sb);
1142 if (!inode)
1143 return ERR_PTR(-ENOMEM);
1144
1145 oi = exofs_i(inode);
1146 __oi_init(oi);
1147
1148 set_obj_2bcreated(oi);
1149
1150 sbi = sb->s_fs_info;
1151
1152 sb->s_dirt = 1;
1153 inode_init_owner(inode, dir, mode);
1154 inode->i_ino = sbi->s_nextid++;
1155 inode->i_blkbits = EXOFS_BLKSHIFT;
1156 inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1157 oi->i_commit_size = inode->i_size = 0;
1158 spin_lock(&sbi->s_next_gen_lock);
1159 inode->i_generation = sbi->s_next_generation++;
1160 spin_unlock(&sbi->s_next_gen_lock);
1161 insert_inode_hash(inode);
1162
1163 mark_inode_dirty(inode);
1164
1165 ret = exofs_get_io_state(&sbi->layout, &ios);
1166 if (unlikely(ret)) {
1167 EXOFS_ERR("exofs_new_inode: exofs_get_io_state failed\n");
1168 return ERR_PTR(ret);
1169 }
1170
1171 ios->obj.id = exofs_oi_objno(oi);
1172 exofs_make_credential(oi->i_cred, &ios->obj);
1173
1174 ios->done = create_done;
1175 ios->private = inode;
1176 ios->cred = oi->i_cred;
1177 ret = exofs_sbi_create(ios);
1178 if (ret) {
1179 exofs_put_io_state(ios);
1180 return ERR_PTR(ret);
1181 }
1182 atomic_inc(&sbi->s_curr_pending);
1183
1184 return inode;
1185 }
1186
1187 /*
1188 * struct to pass two arguments to update_inode's callback
1189 */
1190 struct updatei_args {
1191 struct exofs_sb_info *sbi;
1192 struct exofs_fcb fcb;
1193 };
1194
1195 /*
1196 * Callback function from exofs_update_inode().
1197 */
1198 static void updatei_done(struct exofs_io_state *ios, void *p)
1199 {
1200 struct updatei_args *args = p;
1201
1202 exofs_put_io_state(ios);
1203
1204 atomic_dec(&args->sbi->s_curr_pending);
1205
1206 kfree(args);
1207 }
1208
1209 /*
1210 * Write the inode to the OSD. Just fill up the struct, and set the attribute
1211 * synchronously or asynchronously depending on the do_sync flag.
1212 */
1213 static int exofs_update_inode(struct inode *inode, int do_sync)
1214 {
1215 struct exofs_i_info *oi = exofs_i(inode);
1216 struct super_block *sb = inode->i_sb;
1217 struct exofs_sb_info *sbi = sb->s_fs_info;
1218 struct exofs_io_state *ios;
1219 struct osd_attr attr;
1220 struct exofs_fcb *fcb;
1221 struct updatei_args *args;
1222 int ret;
1223
1224 args = kzalloc(sizeof(*args), GFP_KERNEL);
1225 if (!args) {
1226 EXOFS_DBGMSG("Failed kzalloc of args\n");
1227 return -ENOMEM;
1228 }
1229
1230 fcb = &args->fcb;
1231
1232 fcb->i_mode = cpu_to_le16(inode->i_mode);
1233 fcb->i_uid = cpu_to_le32(inode->i_uid);
1234 fcb->i_gid = cpu_to_le32(inode->i_gid);
1235 fcb->i_links_count = cpu_to_le16(inode->i_nlink);
1236 fcb->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
1237 fcb->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
1238 fcb->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
1239 oi->i_commit_size = i_size_read(inode);
1240 fcb->i_size = cpu_to_le64(oi->i_commit_size);
1241 fcb->i_generation = cpu_to_le32(inode->i_generation);
1242
1243 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
1244 if (old_valid_dev(inode->i_rdev)) {
1245 fcb->i_data[0] =
1246 cpu_to_le32(old_encode_dev(inode->i_rdev));
1247 fcb->i_data[1] = 0;
1248 } else {
1249 fcb->i_data[0] = 0;
1250 fcb->i_data[1] =
1251 cpu_to_le32(new_encode_dev(inode->i_rdev));
1252 fcb->i_data[2] = 0;
1253 }
1254 } else
1255 memcpy(fcb->i_data, oi->i_data, sizeof(fcb->i_data));
1256
1257 ret = exofs_get_io_state(&sbi->layout, &ios);
1258 if (unlikely(ret)) {
1259 EXOFS_ERR("%s: exofs_get_io_state failed.\n", __func__);
1260 goto free_args;
1261 }
1262
1263 attr = g_attr_inode_data;
1264 attr.val_ptr = fcb;
1265 ios->out_attr_len = 1;
1266 ios->out_attr = &attr;
1267
1268 wait_obj_created(oi);
1269
1270 if (!do_sync) {
1271 args->sbi = sbi;
1272 ios->done = updatei_done;
1273 ios->private = args;
1274 }
1275
1276 ret = exofs_oi_write(oi, ios);
1277 if (!do_sync && !ret) {
1278 atomic_inc(&sbi->s_curr_pending);
1279 goto out; /* deallocation in updatei_done */
1280 }
1281
1282 exofs_put_io_state(ios);
1283 free_args:
1284 kfree(args);
1285 out:
1286 EXOFS_DBGMSG("(0x%lx) do_sync=%d ret=>%d\n",
1287 inode->i_ino, do_sync, ret);
1288 return ret;
1289 }
1290
1291 int exofs_write_inode(struct inode *inode, struct writeback_control *wbc)
1292 {
1293 return exofs_update_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
1294 }
1295
1296 /*
1297 * Callback function from exofs_delete_inode() - don't have much cleaning up to
1298 * do.
1299 */
1300 static void delete_done(struct exofs_io_state *ios, void *p)
1301 {
1302 struct exofs_sb_info *sbi = p;
1303
1304 exofs_put_io_state(ios);
1305
1306 atomic_dec(&sbi->s_curr_pending);
1307 }
1308
1309 /*
1310 * Called when the refcount of an inode reaches zero. We remove the object
1311 * from the OSD here. We make sure the object was created before we try and
1312 * delete it.
1313 */
1314 void exofs_evict_inode(struct inode *inode)
1315 {
1316 struct exofs_i_info *oi = exofs_i(inode);
1317 struct super_block *sb = inode->i_sb;
1318 struct exofs_sb_info *sbi = sb->s_fs_info;
1319 struct exofs_io_state *ios;
1320 int ret;
1321
1322 truncate_inode_pages(&inode->i_data, 0);
1323
1324 /* TODO: should do better here */
1325 if (inode->i_nlink || is_bad_inode(inode))
1326 goto no_delete;
1327
1328 inode->i_size = 0;
1329 end_writeback(inode);
1330
1331 /* if we are deleting an obj that hasn't been created yet, wait.
1332 * This also makes sure that create_done cannot be called with an
1333 * already evicted inode.
1334 */
1335 wait_obj_created(oi);
1336 /* ignore the error, attempt a remove anyway */
1337
1338 /* Now Remove the OSD objects */
1339 ret = exofs_get_io_state(&sbi->layout, &ios);
1340 if (unlikely(ret)) {
1341 EXOFS_ERR("%s: exofs_get_io_state failed\n", __func__);
1342 return;
1343 }
1344
1345 ios->obj.id = exofs_oi_objno(oi);
1346 ios->done = delete_done;
1347 ios->private = sbi;
1348 ios->cred = oi->i_cred;
1349 ret = exofs_sbi_remove(ios);
1350 if (ret) {
1351 EXOFS_ERR("%s: exofs_sbi_remove failed\n", __func__);
1352 exofs_put_io_state(ios);
1353 return;
1354 }
1355 atomic_inc(&sbi->s_curr_pending);
1356
1357 return;
1358
1359 no_delete:
1360 end_writeback(inode);
1361 }
Linux 2.6 ibm-acpi/thinkpad-acpi driver git tree