exofs: dbg-print less
[linux-2.6.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/writeback.h>
35 #include <linux/buffer_head.h>
36 #include <scsi/scsi_device.h>
37
38 #include "exofs.h"
39
40 #ifdef CONFIG_EXOFS_DEBUG
41 #  define EXOFS_DEBUG_OBJ_ISIZE 1
42 #endif
43
44 #define EXOFS_DBGMSG2(M...) do {} while (0)
45
46 struct page_collect {
47         struct exofs_sb_info *sbi;
48         struct request_queue *req_q;
49         struct inode *inode;
50         unsigned expected_pages;
51
52         struct bio *bio;
53         unsigned nr_pages;
54         unsigned long length;
55         loff_t pg_first; /* keep 64bit also in 32-arches */
56 };
57
58 static void _pcol_init(struct page_collect *pcol, unsigned expected_pages,
59                 struct inode *inode)
60 {
61         struct exofs_sb_info *sbi = inode->i_sb->s_fs_info;
62
63         pcol->sbi = sbi;
64         pcol->req_q = osd_request_queue(sbi->s_dev);
65         pcol->inode = inode;
66         pcol->expected_pages = expected_pages;
67
68         pcol->bio = NULL;
69         pcol->nr_pages = 0;
70         pcol->length = 0;
71         pcol->pg_first = -1;
72
73         EXOFS_DBGMSG("_pcol_init ino=0x%lx expected_pages=%u\n", inode->i_ino,
74                      expected_pages);
75 }
76
77 static void _pcol_reset(struct page_collect *pcol)
78 {
79         pcol->expected_pages -= min(pcol->nr_pages, pcol->expected_pages);
80
81         pcol->bio = NULL;
82         pcol->nr_pages = 0;
83         pcol->length = 0;
84         pcol->pg_first = -1;
85         EXOFS_DBGMSG("_pcol_reset ino=0x%lx expected_pages=%u\n",
86                      pcol->inode->i_ino, pcol->expected_pages);
87
88         /* this is probably the end of the loop but in writes
89          * it might not end here. don't be left with nothing
90          */
91         if (!pcol->expected_pages)
92                 pcol->expected_pages = 128;
93 }
94
95 static int pcol_try_alloc(struct page_collect *pcol)
96 {
97         int pages = min_t(unsigned, pcol->expected_pages, BIO_MAX_PAGES);
98
99         for (; pages; pages >>= 1) {
100                 pcol->bio = bio_alloc(GFP_KERNEL, pages);
101                 if (likely(pcol->bio))
102                         return 0;
103         }
104
105         EXOFS_ERR("Failed to kcalloc expected_pages=%u\n",
106                   pcol->expected_pages);
107         return -ENOMEM;
108 }
109
110 static void pcol_free(struct page_collect *pcol)
111 {
112         bio_put(pcol->bio);
113         pcol->bio = NULL;
114 }
115
116 static int pcol_add_page(struct page_collect *pcol, struct page *page,
117                          unsigned len)
118 {
119         int added_len = bio_add_pc_page(pcol->req_q, pcol->bio, page, len, 0);
120         if (unlikely(len != added_len))
121                 return -ENOMEM;
122
123         ++pcol->nr_pages;
124         pcol->length += len;
125         return 0;
126 }
127
128 static int update_read_page(struct page *page, int ret)
129 {
130         if (ret == 0) {
131                 /* Everything is OK */
132                 SetPageUptodate(page);
133                 if (PageError(page))
134                         ClearPageError(page);
135         } else if (ret == -EFAULT) {
136                 /* In this case we were trying to read something that wasn't on
137                  * disk yet - return a page full of zeroes.  This should be OK,
138                  * because the object should be empty (if there was a write
139                  * before this read, the read would be waiting with the page
140                  * locked */
141                 clear_highpage(page);
142
143                 SetPageUptodate(page);
144                 if (PageError(page))
145                         ClearPageError(page);
146                 ret = 0; /* recovered error */
147                 EXOFS_DBGMSG("recovered read error\n");
148         } else /* Error */
149                 SetPageError(page);
150
151         return ret;
152 }
153
154 static void update_write_page(struct page *page, int ret)
155 {
156         if (ret) {
157                 mapping_set_error(page->mapping, ret);
158                 SetPageError(page);
159         }
160         end_page_writeback(page);
161 }
162
163 /* Called at the end of reads, to optionally unlock pages and update their
164  * status.
165  */
166 static int __readpages_done(struct osd_request *or, struct page_collect *pcol,
167                             bool do_unlock)
168 {
169         struct bio_vec *bvec;
170         int i;
171         u64 resid;
172         u64 good_bytes;
173         u64 length = 0;
174         int ret = exofs_check_ok_resid(or, &resid, NULL);
175
176         osd_end_request(or);
177
178         if (likely(!ret))
179                 good_bytes = pcol->length;
180         else if (!resid)
181                 good_bytes = 0;
182         else
183                 good_bytes = pcol->length - resid;
184
185         EXOFS_DBGMSG("readpages_done(0x%lx) good_bytes=0x%llx"
186                      " length=0x%lx nr_pages=%u\n",
187                      pcol->inode->i_ino, _LLU(good_bytes), pcol->length,
188                      pcol->nr_pages);
189
190         __bio_for_each_segment(bvec, pcol->bio, i, 0) {
191                 struct page *page = bvec->bv_page;
192                 struct inode *inode = page->mapping->host;
193                 int page_stat;
194
195                 if (inode != pcol->inode)
196                         continue; /* osd might add more pages at end */
197
198                 if (likely(length < good_bytes))
199                         page_stat = 0;
200                 else
201                         page_stat = ret;
202
203                 EXOFS_DBGMSG2("    readpages_done(0x%lx, 0x%lx) %s\n",
204                           inode->i_ino, page->index,
205                           page_stat ? "bad_bytes" : "good_bytes");
206
207                 ret = update_read_page(page, page_stat);
208                 if (do_unlock)
209                         unlock_page(page);
210                 length += bvec->bv_len;
211         }
212
213         pcol_free(pcol);
214         EXOFS_DBGMSG("readpages_done END\n");
215         return ret;
216 }
217
218 /* callback of async reads */
219 static void readpages_done(struct osd_request *or, void *p)
220 {
221         struct page_collect *pcol = p;
222
223         __readpages_done(or, pcol, true);
224         atomic_dec(&pcol->sbi->s_curr_pending);
225         kfree(p);
226 }
227
228 static void _unlock_pcol_pages(struct page_collect *pcol, int ret, int rw)
229 {
230         struct bio_vec *bvec;
231         int i;
232
233         __bio_for_each_segment(bvec, pcol->bio, i, 0) {
234                 struct page *page = bvec->bv_page;
235
236                 if (rw == READ)
237                         update_read_page(page, ret);
238                 else
239                         update_write_page(page, ret);
240
241                 unlock_page(page);
242         }
243         pcol_free(pcol);
244 }
245
246 static int read_exec(struct page_collect *pcol, bool is_sync)
247 {
248         struct exofs_i_info *oi = exofs_i(pcol->inode);
249         struct osd_obj_id obj = {pcol->sbi->s_pid,
250                                         pcol->inode->i_ino + EXOFS_OBJ_OFF};
251         struct osd_request *or = NULL;
252         struct page_collect *pcol_copy = NULL;
253         loff_t i_start = pcol->pg_first << PAGE_CACHE_SHIFT;
254         int ret;
255
256         if (!pcol->bio)
257                 return 0;
258
259         /* see comment in _readpage() about sync reads */
260         WARN_ON(is_sync && (pcol->nr_pages != 1));
261
262         or = osd_start_request(pcol->sbi->s_dev, GFP_KERNEL);
263         if (unlikely(!or)) {
264                 ret = -ENOMEM;
265                 goto err;
266         }
267
268         osd_req_read(or, &obj, i_start, pcol->bio, pcol->length);
269
270         if (is_sync) {
271                 exofs_sync_op(or, pcol->sbi->s_timeout, oi->i_cred);
272                 return __readpages_done(or, pcol, false);
273         }
274
275         pcol_copy = kmalloc(sizeof(*pcol_copy), GFP_KERNEL);
276         if (!pcol_copy) {
277                 ret = -ENOMEM;
278                 goto err;
279         }
280
281         *pcol_copy = *pcol;
282         ret = exofs_async_op(or, readpages_done, pcol_copy, oi->i_cred);
283         if (unlikely(ret))
284                 goto err;
285
286         atomic_inc(&pcol->sbi->s_curr_pending);
287
288         EXOFS_DBGMSG("read_exec obj=0x%llx start=0x%llx length=0x%lx\n",
289                   obj.id, _LLU(i_start), pcol->length);
290
291         /* pages ownership was passed to pcol_copy */
292         _pcol_reset(pcol);
293         return 0;
294
295 err:
296         if (!is_sync)
297                 _unlock_pcol_pages(pcol, ret, READ);
298         else /* Pages unlocked by caller in sync mode only free bio */
299                 pcol_free(pcol);
300
301         kfree(pcol_copy);
302         if (or)
303                 osd_end_request(or);
304         return ret;
305 }
306
307 /* readpage_strip is called either directly from readpage() or by the VFS from
308  * within read_cache_pages(), to add one more page to be read. It will try to
309  * collect as many contiguous pages as posible. If a discontinuity is
310  * encountered, or it runs out of resources, it will submit the previous segment
311  * and will start a new collection. Eventually caller must submit the last
312  * segment if present.
313  */
314 static int readpage_strip(void *data, struct page *page)
315 {
316         struct page_collect *pcol = data;
317         struct inode *inode = pcol->inode;
318         struct exofs_i_info *oi = exofs_i(inode);
319         loff_t i_size = i_size_read(inode);
320         pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
321         size_t len;
322         int ret;
323
324         /* FIXME: Just for debugging, will be removed */
325         if (PageUptodate(page))
326                 EXOFS_ERR("PageUptodate(0x%lx, 0x%lx)\n", pcol->inode->i_ino,
327                           page->index);
328
329         if (page->index < end_index)
330                 len = PAGE_CACHE_SIZE;
331         else if (page->index == end_index)
332                 len = i_size & ~PAGE_CACHE_MASK;
333         else
334                 len = 0;
335
336         if (!len || !obj_created(oi)) {
337                 /* this will be out of bounds, or doesn't exist yet.
338                  * Current page is cleared and the request is split
339                  */
340                 clear_highpage(page);
341
342                 SetPageUptodate(page);
343                 if (PageError(page))
344                         ClearPageError(page);
345
346                 unlock_page(page);
347                 EXOFS_DBGMSG("readpage_strip(0x%lx, 0x%lx) empty page,"
348                              " splitting\n", inode->i_ino, page->index);
349
350                 return read_exec(pcol, false);
351         }
352
353 try_again:
354
355         if (unlikely(pcol->pg_first == -1)) {
356                 pcol->pg_first = page->index;
357         } else if (unlikely((pcol->pg_first + pcol->nr_pages) !=
358                    page->index)) {
359                 /* Discontinuity detected, split the request */
360                 ret = read_exec(pcol, false);
361                 if (unlikely(ret))
362                         goto fail;
363                 goto try_again;
364         }
365
366         if (!pcol->bio) {
367                 ret = pcol_try_alloc(pcol);
368                 if (unlikely(ret))
369                         goto fail;
370         }
371
372         if (len != PAGE_CACHE_SIZE)
373                 zero_user(page, len, PAGE_CACHE_SIZE - len);
374
375         EXOFS_DBGMSG2("    readpage_strip(0x%lx, 0x%lx) len=0x%zx\n",
376                      inode->i_ino, page->index, len);
377
378         ret = pcol_add_page(pcol, page, len);
379         if (ret) {
380                 EXOFS_DBGMSG2("Failed pcol_add_page pages[i]=%p "
381                           "this_len=0x%zx nr_pages=%u length=0x%lx\n",
382                           page, len, pcol->nr_pages, pcol->length);
383
384                 /* split the request, and start again with current page */
385                 ret = read_exec(pcol, false);
386                 if (unlikely(ret))
387                         goto fail;
388
389                 goto try_again;
390         }
391
392         return 0;
393
394 fail:
395         /* SetPageError(page); ??? */
396         unlock_page(page);
397         return ret;
398 }
399
400 static int exofs_readpages(struct file *file, struct address_space *mapping,
401                            struct list_head *pages, unsigned nr_pages)
402 {
403         struct page_collect pcol;
404         int ret;
405
406         _pcol_init(&pcol, nr_pages, mapping->host);
407
408         ret = read_cache_pages(mapping, pages, readpage_strip, &pcol);
409         if (ret) {
410                 EXOFS_ERR("read_cache_pages => %d\n", ret);
411                 return ret;
412         }
413
414         return read_exec(&pcol, false);
415 }
416
417 static int _readpage(struct page *page, bool is_sync)
418 {
419         struct page_collect pcol;
420         int ret;
421
422         _pcol_init(&pcol, 1, page->mapping->host);
423
424         /* readpage_strip might call read_exec(,async) inside at several places
425          * but this is safe for is_async=0 since read_exec will not do anything
426          * when we have a single page.
427          */
428         ret = readpage_strip(&pcol, page);
429         if (ret) {
430                 EXOFS_ERR("_readpage => %d\n", ret);
431                 return ret;
432         }
433
434         return read_exec(&pcol, is_sync);
435 }
436
437 /*
438  * We don't need the file
439  */
440 static int exofs_readpage(struct file *file, struct page *page)
441 {
442         return _readpage(page, false);
443 }
444
445 /* Callback for osd_write. All writes are asynchronouse */
446 static void writepages_done(struct osd_request *or, void *p)
447 {
448         struct page_collect *pcol = p;
449         struct bio_vec *bvec;
450         int i;
451         u64 resid;
452         u64  good_bytes;
453         u64  length = 0;
454
455         int ret = exofs_check_ok_resid(or, NULL, &resid);
456
457         osd_end_request(or);
458         atomic_dec(&pcol->sbi->s_curr_pending);
459
460         if (likely(!ret))
461                 good_bytes = pcol->length;
462         else if (!resid)
463                 good_bytes = 0;
464         else
465                 good_bytes = pcol->length - resid;
466
467         EXOFS_DBGMSG("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         __bio_for_each_segment(bvec, pcol->bio, i, 0) {
473                 struct page *page = bvec->bv_page;
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 += bvec->bv_len;
491         }
492
493         pcol_free(pcol);
494         kfree(pcol);
495         EXOFS_DBGMSG("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 osd_obj_id obj = {pcol->sbi->s_pid,
502                                         pcol->inode->i_ino + EXOFS_OBJ_OFF};
503         struct osd_request *or = NULL;
504         struct page_collect *pcol_copy = NULL;
505         loff_t i_start = pcol->pg_first << PAGE_CACHE_SHIFT;
506         int ret;
507
508         if (!pcol->bio)
509                 return 0;
510
511         or = osd_start_request(pcol->sbi->s_dev, GFP_KERNEL);
512         if (unlikely(!or)) {
513                 EXOFS_ERR("write_exec: Faild to osd_start_request()\n");
514                 ret = -ENOMEM;
515                 goto err;
516         }
517
518         pcol_copy = kmalloc(sizeof(*pcol_copy), GFP_KERNEL);
519         if (!pcol_copy) {
520                 EXOFS_ERR("write_exec: Faild to kmalloc(pcol)\n");
521                 ret = -ENOMEM;
522                 goto err;
523         }
524
525         *pcol_copy = *pcol;
526
527         pcol_copy->bio->bi_rw |= (1 << BIO_RW); /* FIXME: bio_set_dir() */
528         osd_req_write(or, &obj, i_start, pcol_copy->bio, pcol_copy->length);
529         ret = exofs_async_op(or, writepages_done, pcol_copy, oi->i_cred);
530         if (unlikely(ret)) {
531                 EXOFS_ERR("write_exec: exofs_async_op() Faild\n");
532                 goto err;
533         }
534
535         atomic_inc(&pcol->sbi->s_curr_pending);
536         EXOFS_DBGMSG("write_exec(0x%lx, 0x%llx) start=0x%llx length=0x%lx\n",
537                   pcol->inode->i_ino, pcol->pg_first, _LLU(i_start),
538                   pcol->length);
539         /* pages ownership was passed to pcol_copy */
540         _pcol_reset(pcol);
541         return 0;
542
543 err:
544         _unlock_pcol_pages(pcol, ret, WRITE);
545         kfree(pcol_copy);
546         if (or)
547                 osd_end_request(or);
548         return ret;
549 }
550
551 /* writepage_strip is called either directly from writepage() or by the VFS from
552  * within write_cache_pages(), to add one more page to be written to storage.
553  * It will try to collect as many contiguous pages as possible. If a
554  * discontinuity is encountered or it runs out of resources it will submit the
555  * previous segment and will start a new collection.
556  * Eventually caller must submit the last segment if present.
557  */
558 static int writepage_strip(struct page *page,
559                            struct writeback_control *wbc_unused, void *data)
560 {
561         struct page_collect *pcol = data;
562         struct inode *inode = pcol->inode;
563         struct exofs_i_info *oi = exofs_i(inode);
564         loff_t i_size = i_size_read(inode);
565         pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
566         size_t len;
567         int ret;
568
569         BUG_ON(!PageLocked(page));
570
571         ret = wait_obj_created(oi);
572         if (unlikely(ret))
573                 goto fail;
574
575         if (page->index < end_index)
576                 /* in this case, the page is within the limits of the file */
577                 len = PAGE_CACHE_SIZE;
578         else {
579                 len = i_size & ~PAGE_CACHE_MASK;
580
581                 if (page->index > end_index || !len) {
582                         /* in this case, the page is outside the limits
583                          * (truncate in progress)
584                          */
585                         ret = write_exec(pcol);
586                         if (unlikely(ret))
587                                 goto fail;
588                         if (PageError(page))
589                                 ClearPageError(page);
590                         unlock_page(page);
591                         return 0;
592                 }
593         }
594
595 try_again:
596
597         if (unlikely(pcol->pg_first == -1)) {
598                 pcol->pg_first = page->index;
599         } else if (unlikely((pcol->pg_first + pcol->nr_pages) !=
600                    page->index)) {
601                 /* Discontinuity detected, split the request */
602                 ret = write_exec(pcol);
603                 if (unlikely(ret))
604                         goto fail;
605                 goto try_again;
606         }
607
608         if (!pcol->bio) {
609                 ret = pcol_try_alloc(pcol);
610                 if (unlikely(ret))
611                         goto fail;
612         }
613
614         EXOFS_DBGMSG2("    writepage_strip(0x%lx, 0x%lx) len=0x%zx\n",
615                      inode->i_ino, page->index, len);
616
617         ret = pcol_add_page(pcol, page, len);
618         if (unlikely(ret)) {
619                 EXOFS_DBGMSG("Failed pcol_add_page "
620                              "nr_pages=%u total_length=0x%lx\n",
621                              pcol->nr_pages, pcol->length);
622
623                 /* split the request, next loop will start again */
624                 ret = write_exec(pcol);
625                 if (unlikely(ret)) {
626                         EXOFS_DBGMSG("write_exec faild => %d", ret);
627                         goto fail;
628                 }
629
630                 goto try_again;
631         }
632
633         BUG_ON(PageWriteback(page));
634         set_page_writeback(page);
635
636         return 0;
637
638 fail:
639         set_bit(AS_EIO, &page->mapping->flags);
640         unlock_page(page);
641         return ret;
642 }
643
644 static int exofs_writepages(struct address_space *mapping,
645                        struct writeback_control *wbc)
646 {
647         struct page_collect pcol;
648         long start, end, expected_pages;
649         int ret;
650
651         start = wbc->range_start >> PAGE_CACHE_SHIFT;
652         end = (wbc->range_end == LLONG_MAX) ?
653                         start + mapping->nrpages :
654                         wbc->range_end >> PAGE_CACHE_SHIFT;
655
656         if (start || end)
657                 expected_pages = min(end - start + 1, 32L);
658         else
659                 expected_pages = mapping->nrpages;
660
661         EXOFS_DBGMSG("inode(0x%lx) wbc->start=0x%llx wbc->end=0x%llx"
662                      " m->nrpages=%lu start=0x%lx end=0x%lx\n",
663                      mapping->host->i_ino, wbc->range_start, wbc->range_end,
664                      mapping->nrpages, start, end);
665
666         _pcol_init(&pcol, expected_pages, mapping->host);
667
668         ret = write_cache_pages(mapping, wbc, writepage_strip, &pcol);
669         if (ret) {
670                 EXOFS_ERR("write_cache_pages => %d\n", ret);
671                 return ret;
672         }
673
674         return write_exec(&pcol);
675 }
676
677 static int exofs_writepage(struct page *page, struct writeback_control *wbc)
678 {
679         struct page_collect pcol;
680         int ret;
681
682         _pcol_init(&pcol, 1, page->mapping->host);
683
684         ret = writepage_strip(page, NULL, &pcol);
685         if (ret) {
686                 EXOFS_ERR("exofs_writepage => %d\n", ret);
687                 return ret;
688         }
689
690         return write_exec(&pcol);
691 }
692
693 int exofs_write_begin(struct file *file, struct address_space *mapping,
694                 loff_t pos, unsigned len, unsigned flags,
695                 struct page **pagep, void **fsdata)
696 {
697         int ret = 0;
698         struct page *page;
699
700         page = *pagep;
701         if (page == NULL) {
702                 ret = simple_write_begin(file, mapping, pos, len, flags, pagep,
703                                          fsdata);
704                 if (ret) {
705                         EXOFS_DBGMSG("simple_write_begin faild\n");
706                         return ret;
707                 }
708
709                 page = *pagep;
710         }
711
712          /* read modify write */
713         if (!PageUptodate(page) && (len != PAGE_CACHE_SIZE)) {
714                 ret = _readpage(page, true);
715                 if (ret) {
716                         /*SetPageError was done by _readpage. Is it ok?*/
717                         unlock_page(page);
718                         EXOFS_DBGMSG("__readpage_filler faild\n");
719                 }
720         }
721
722         return ret;
723 }
724
725 static int exofs_write_begin_export(struct file *file,
726                 struct address_space *mapping,
727                 loff_t pos, unsigned len, unsigned flags,
728                 struct page **pagep, void **fsdata)
729 {
730         *pagep = NULL;
731
732         return exofs_write_begin(file, mapping, pos, len, flags, pagep,
733                                         fsdata);
734 }
735
736 const struct address_space_operations exofs_aops = {
737         .readpage       = exofs_readpage,
738         .readpages      = exofs_readpages,
739         .writepage      = exofs_writepage,
740         .writepages     = exofs_writepages,
741         .write_begin    = exofs_write_begin_export,
742         .write_end      = simple_write_end,
743 };
744
745 /******************************************************************************
746  * INODE OPERATIONS
747  *****************************************************************************/
748
749 /*
750  * Test whether an inode is a fast symlink.
751  */
752 static inline int exofs_inode_is_fast_symlink(struct inode *inode)
753 {
754         struct exofs_i_info *oi = exofs_i(inode);
755
756         return S_ISLNK(inode->i_mode) && (oi->i_data[0] != 0);
757 }
758
759 /*
760  * get_block_t - Fill in a buffer_head
761  * An OSD takes care of block allocation so we just fake an allocation by
762  * putting in the inode's sector_t in the buffer_head.
763  * TODO: What about the case of create==0 and @iblock does not exist in the
764  * object?
765  */
766 static int exofs_get_block(struct inode *inode, sector_t iblock,
767                     struct buffer_head *bh_result, int create)
768 {
769         map_bh(bh_result, inode->i_sb, iblock);
770         return 0;
771 }
772
773 const struct osd_attr g_attr_logical_length = ATTR_DEF(
774         OSD_APAGE_OBJECT_INFORMATION, OSD_ATTR_OI_LOGICAL_LENGTH, 8);
775
776 /*
777  * Truncate a file to the specified size - all we have to do is set the size
778  * attribute.  We make sure the object exists first.
779  */
780 void exofs_truncate(struct inode *inode)
781 {
782         struct exofs_sb_info *sbi = inode->i_sb->s_fs_info;
783         struct exofs_i_info *oi = exofs_i(inode);
784         struct osd_obj_id obj = {sbi->s_pid, inode->i_ino + EXOFS_OBJ_OFF};
785         struct osd_request *or;
786         struct osd_attr attr;
787         loff_t isize = i_size_read(inode);
788         __be64 newsize;
789         int ret;
790
791         if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)
792              || S_ISLNK(inode->i_mode)))
793                 return;
794         if (exofs_inode_is_fast_symlink(inode))
795                 return;
796         if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
797                 return;
798         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
799
800         nobh_truncate_page(inode->i_mapping, isize, exofs_get_block);
801
802         or = osd_start_request(sbi->s_dev, GFP_KERNEL);
803         if (unlikely(!or)) {
804                 EXOFS_ERR("ERROR: exofs_truncate: osd_start_request failed\n");
805                 goto fail;
806         }
807
808         osd_req_set_attributes(or, &obj);
809
810         newsize = cpu_to_be64((u64)isize);
811         attr = g_attr_logical_length;
812         attr.val_ptr = &newsize;
813         osd_req_add_set_attr_list(or, &attr, 1);
814
815         /* if we are about to truncate an object, and it hasn't been
816          * created yet, wait
817          */
818         if (unlikely(wait_obj_created(oi)))
819                 goto fail;
820
821         ret = exofs_sync_op(or, sbi->s_timeout, oi->i_cred);
822         osd_end_request(or);
823         if (ret)
824                 goto fail;
825
826 out:
827         mark_inode_dirty(inode);
828         return;
829 fail:
830         make_bad_inode(inode);
831         goto out;
832 }
833
834 /*
835  * Set inode attributes - just call generic functions.
836  */
837 int exofs_setattr(struct dentry *dentry, struct iattr *iattr)
838 {
839         struct inode *inode = dentry->d_inode;
840         int error;
841
842         error = inode_change_ok(inode, iattr);
843         if (error)
844                 return error;
845
846         error = inode_setattr(inode, iattr);
847         return error;
848 }
849
850 /*
851  * Read an inode from the OSD, and return it as is.  We also return the size
852  * attribute in the 'sanity' argument if we got compiled with debugging turned
853  * on.
854  */
855 static int exofs_get_inode(struct super_block *sb, struct exofs_i_info *oi,
856                     struct exofs_fcb *inode, uint64_t *sanity)
857 {
858         struct exofs_sb_info *sbi = sb->s_fs_info;
859         struct osd_request *or;
860         struct osd_attr attr;
861         struct osd_obj_id obj = {sbi->s_pid,
862                                  oi->vfs_inode.i_ino + EXOFS_OBJ_OFF};
863         int ret;
864
865         exofs_make_credential(oi->i_cred, &obj);
866
867         or = osd_start_request(sbi->s_dev, GFP_KERNEL);
868         if (unlikely(!or)) {
869                 EXOFS_ERR("exofs_get_inode: osd_start_request failed.\n");
870                 return -ENOMEM;
871         }
872         osd_req_get_attributes(or, &obj);
873
874         /* we need the inode attribute */
875         osd_req_add_get_attr_list(or, &g_attr_inode_data, 1);
876
877 #ifdef EXOFS_DEBUG_OBJ_ISIZE
878         /* we get the size attributes to do a sanity check */
879         osd_req_add_get_attr_list(or, &g_attr_logical_length, 1);
880 #endif
881
882         ret = exofs_sync_op(or, sbi->s_timeout, oi->i_cred);
883         if (ret)
884                 goto out;
885
886         attr = g_attr_inode_data;
887         ret = extract_attr_from_req(or, &attr);
888         if (ret) {
889                 EXOFS_ERR("exofs_get_inode: extract_attr_from_req failed\n");
890                 goto out;
891         }
892
893         WARN_ON(attr.len != EXOFS_INO_ATTR_SIZE);
894         memcpy(inode, attr.val_ptr, EXOFS_INO_ATTR_SIZE);
895
896 #ifdef EXOFS_DEBUG_OBJ_ISIZE
897         attr = g_attr_logical_length;
898         ret = extract_attr_from_req(or, &attr);
899         if (ret) {
900                 EXOFS_ERR("ERROR: extract attr from or failed\n");
901                 goto out;
902         }
903         *sanity = get_unaligned_be64(attr.val_ptr);
904 #endif
905
906 out:
907         osd_end_request(or);
908         return ret;
909 }
910
911 /*
912  * Fill in an inode read from the OSD and set it up for use
913  */
914 struct inode *exofs_iget(struct super_block *sb, unsigned long ino)
915 {
916         struct exofs_i_info *oi;
917         struct exofs_fcb fcb;
918         struct inode *inode;
919         uint64_t uninitialized_var(sanity);
920         int ret;
921
922         inode = iget_locked(sb, ino);
923         if (!inode)
924                 return ERR_PTR(-ENOMEM);
925         if (!(inode->i_state & I_NEW))
926                 return inode;
927         oi = exofs_i(inode);
928
929         /* read the inode from the osd */
930         ret = exofs_get_inode(sb, oi, &fcb, &sanity);
931         if (ret)
932                 goto bad_inode;
933
934         init_waitqueue_head(&oi->i_wq);
935         set_obj_created(oi);
936
937         /* copy stuff from on-disk struct to in-memory struct */
938         inode->i_mode = le16_to_cpu(fcb.i_mode);
939         inode->i_uid = le32_to_cpu(fcb.i_uid);
940         inode->i_gid = le32_to_cpu(fcb.i_gid);
941         inode->i_nlink = le16_to_cpu(fcb.i_links_count);
942         inode->i_ctime.tv_sec = (signed)le32_to_cpu(fcb.i_ctime);
943         inode->i_atime.tv_sec = (signed)le32_to_cpu(fcb.i_atime);
944         inode->i_mtime.tv_sec = (signed)le32_to_cpu(fcb.i_mtime);
945         inode->i_ctime.tv_nsec =
946                 inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = 0;
947         oi->i_commit_size = le64_to_cpu(fcb.i_size);
948         i_size_write(inode, oi->i_commit_size);
949         inode->i_blkbits = EXOFS_BLKSHIFT;
950         inode->i_generation = le32_to_cpu(fcb.i_generation);
951
952 #ifdef EXOFS_DEBUG_OBJ_ISIZE
953         if ((inode->i_size != sanity) &&
954                 (!exofs_inode_is_fast_symlink(inode))) {
955                 EXOFS_ERR("WARNING: Size of inode=%llu != object=%llu\n",
956                           inode->i_size, _LLU(sanity));
957         }
958 #endif
959
960         oi->i_dir_start_lookup = 0;
961
962         if ((inode->i_nlink == 0) && (inode->i_mode == 0)) {
963                 ret = -ESTALE;
964                 goto bad_inode;
965         }
966
967         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
968                 if (fcb.i_data[0])
969                         inode->i_rdev =
970                                 old_decode_dev(le32_to_cpu(fcb.i_data[0]));
971                 else
972                         inode->i_rdev =
973                                 new_decode_dev(le32_to_cpu(fcb.i_data[1]));
974         } else {
975                 memcpy(oi->i_data, fcb.i_data, sizeof(fcb.i_data));
976         }
977
978         if (S_ISREG(inode->i_mode)) {
979                 inode->i_op = &exofs_file_inode_operations;
980                 inode->i_fop = &exofs_file_operations;
981                 inode->i_mapping->a_ops = &exofs_aops;
982         } else if (S_ISDIR(inode->i_mode)) {
983                 inode->i_op = &exofs_dir_inode_operations;
984                 inode->i_fop = &exofs_dir_operations;
985                 inode->i_mapping->a_ops = &exofs_aops;
986         } else if (S_ISLNK(inode->i_mode)) {
987                 if (exofs_inode_is_fast_symlink(inode))
988                         inode->i_op = &exofs_fast_symlink_inode_operations;
989                 else {
990                         inode->i_op = &exofs_symlink_inode_operations;
991                         inode->i_mapping->a_ops = &exofs_aops;
992                 }
993         } else {
994                 inode->i_op = &exofs_special_inode_operations;
995                 if (fcb.i_data[0])
996                         init_special_inode(inode, inode->i_mode,
997                            old_decode_dev(le32_to_cpu(fcb.i_data[0])));
998                 else
999                         init_special_inode(inode, inode->i_mode,
1000                            new_decode_dev(le32_to_cpu(fcb.i_data[1])));
1001         }
1002
1003         unlock_new_inode(inode);
1004         return inode;
1005
1006 bad_inode:
1007         iget_failed(inode);
1008         return ERR_PTR(ret);
1009 }
1010
1011 int __exofs_wait_obj_created(struct exofs_i_info *oi)
1012 {
1013         if (!obj_created(oi)) {
1014                 BUG_ON(!obj_2bcreated(oi));
1015                 wait_event(oi->i_wq, obj_created(oi));
1016         }
1017         return unlikely(is_bad_inode(&oi->vfs_inode)) ? -EIO : 0;
1018 }
1019 /*
1020  * Callback function from exofs_new_inode().  The important thing is that we
1021  * set the obj_created flag so that other methods know that the object exists on
1022  * the OSD.
1023  */
1024 static void create_done(struct osd_request *or, void *p)
1025 {
1026         struct inode *inode = p;
1027         struct exofs_i_info *oi = exofs_i(inode);
1028         struct exofs_sb_info *sbi = inode->i_sb->s_fs_info;
1029         int ret;
1030
1031         ret = exofs_check_ok(or);
1032         osd_end_request(or);
1033         atomic_dec(&sbi->s_curr_pending);
1034
1035         if (unlikely(ret)) {
1036                 EXOFS_ERR("object=0x%llx creation faild in pid=0x%llx",
1037                           _LLU(sbi->s_pid), _LLU(inode->i_ino + EXOFS_OBJ_OFF));
1038                 make_bad_inode(inode);
1039         } else
1040                 set_obj_created(oi);
1041
1042         atomic_dec(&inode->i_count);
1043         wake_up(&oi->i_wq);
1044 }
1045
1046 /*
1047  * Set up a new inode and create an object for it on the OSD
1048  */
1049 struct inode *exofs_new_inode(struct inode *dir, int mode)
1050 {
1051         struct super_block *sb;
1052         struct inode *inode;
1053         struct exofs_i_info *oi;
1054         struct exofs_sb_info *sbi;
1055         struct osd_request *or;
1056         struct osd_obj_id obj;
1057         int ret;
1058
1059         sb = dir->i_sb;
1060         inode = new_inode(sb);
1061         if (!inode)
1062                 return ERR_PTR(-ENOMEM);
1063
1064         oi = exofs_i(inode);
1065
1066         init_waitqueue_head(&oi->i_wq);
1067         set_obj_2bcreated(oi);
1068
1069         sbi = sb->s_fs_info;
1070
1071         sb->s_dirt = 1;
1072         inode->i_uid = current->cred->fsuid;
1073         if (dir->i_mode & S_ISGID) {
1074                 inode->i_gid = dir->i_gid;
1075                 if (S_ISDIR(mode))
1076                         mode |= S_ISGID;
1077         } else {
1078                 inode->i_gid = current->cred->fsgid;
1079         }
1080         inode->i_mode = mode;
1081
1082         inode->i_ino = sbi->s_nextid++;
1083         inode->i_blkbits = EXOFS_BLKSHIFT;
1084         inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
1085         oi->i_commit_size = inode->i_size = 0;
1086         spin_lock(&sbi->s_next_gen_lock);
1087         inode->i_generation = sbi->s_next_generation++;
1088         spin_unlock(&sbi->s_next_gen_lock);
1089         insert_inode_hash(inode);
1090
1091         mark_inode_dirty(inode);
1092
1093         obj.partition = sbi->s_pid;
1094         obj.id = inode->i_ino + EXOFS_OBJ_OFF;
1095         exofs_make_credential(oi->i_cred, &obj);
1096
1097         or = osd_start_request(sbi->s_dev, GFP_KERNEL);
1098         if (unlikely(!or)) {
1099                 EXOFS_ERR("exofs_new_inode: osd_start_request failed\n");
1100                 return ERR_PTR(-ENOMEM);
1101         }
1102
1103         osd_req_create_object(or, &obj);
1104
1105         /* increment the refcount so that the inode will still be around when we
1106          * reach the callback
1107          */
1108         atomic_inc(&inode->i_count);
1109
1110         ret = exofs_async_op(or, create_done, inode, oi->i_cred);
1111         if (ret) {
1112                 atomic_dec(&inode->i_count);
1113                 osd_end_request(or);
1114                 return ERR_PTR(-EIO);
1115         }
1116         atomic_inc(&sbi->s_curr_pending);
1117
1118         return inode;
1119 }
1120
1121 /*
1122  * struct to pass two arguments to update_inode's callback
1123  */
1124 struct updatei_args {
1125         struct exofs_sb_info    *sbi;
1126         struct exofs_fcb        fcb;
1127 };
1128
1129 /*
1130  * Callback function from exofs_update_inode().
1131  */
1132 static void updatei_done(struct osd_request *or, void *p)
1133 {
1134         struct updatei_args *args = p;
1135
1136         osd_end_request(or);
1137
1138         atomic_dec(&args->sbi->s_curr_pending);
1139
1140         kfree(args);
1141 }
1142
1143 /*
1144  * Write the inode to the OSD.  Just fill up the struct, and set the attribute
1145  * synchronously or asynchronously depending on the do_sync flag.
1146  */
1147 static int exofs_update_inode(struct inode *inode, int do_sync)
1148 {
1149         struct exofs_i_info *oi = exofs_i(inode);
1150         struct super_block *sb = inode->i_sb;
1151         struct exofs_sb_info *sbi = sb->s_fs_info;
1152         struct osd_obj_id obj = {sbi->s_pid, inode->i_ino + EXOFS_OBJ_OFF};
1153         struct osd_request *or;
1154         struct osd_attr attr;
1155         struct exofs_fcb *fcb;
1156         struct updatei_args *args;
1157         int ret;
1158
1159         args = kzalloc(sizeof(*args), GFP_KERNEL);
1160         if (!args)
1161                 return -ENOMEM;
1162
1163         fcb = &args->fcb;
1164
1165         fcb->i_mode = cpu_to_le16(inode->i_mode);
1166         fcb->i_uid = cpu_to_le32(inode->i_uid);
1167         fcb->i_gid = cpu_to_le32(inode->i_gid);
1168         fcb->i_links_count = cpu_to_le16(inode->i_nlink);
1169         fcb->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
1170         fcb->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
1171         fcb->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
1172         oi->i_commit_size = i_size_read(inode);
1173         fcb->i_size = cpu_to_le64(oi->i_commit_size);
1174         fcb->i_generation = cpu_to_le32(inode->i_generation);
1175
1176         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
1177                 if (old_valid_dev(inode->i_rdev)) {
1178                         fcb->i_data[0] =
1179                                 cpu_to_le32(old_encode_dev(inode->i_rdev));
1180                         fcb->i_data[1] = 0;
1181                 } else {
1182                         fcb->i_data[0] = 0;
1183                         fcb->i_data[1] =
1184                                 cpu_to_le32(new_encode_dev(inode->i_rdev));
1185                         fcb->i_data[2] = 0;
1186                 }
1187         } else
1188                 memcpy(fcb->i_data, oi->i_data, sizeof(fcb->i_data));
1189
1190         or = osd_start_request(sbi->s_dev, GFP_KERNEL);
1191         if (unlikely(!or)) {
1192                 EXOFS_ERR("exofs_update_inode: osd_start_request failed.\n");
1193                 ret = -ENOMEM;
1194                 goto free_args;
1195         }
1196
1197         osd_req_set_attributes(or, &obj);
1198
1199         attr = g_attr_inode_data;
1200         attr.val_ptr = fcb;
1201         osd_req_add_set_attr_list(or, &attr, 1);
1202
1203         if (!obj_created(oi)) {
1204                 EXOFS_DBGMSG("!obj_created\n");
1205                 BUG_ON(!obj_2bcreated(oi));
1206                 wait_event(oi->i_wq, obj_created(oi));
1207                 EXOFS_DBGMSG("wait_event done\n");
1208         }
1209
1210         if (do_sync) {
1211                 ret = exofs_sync_op(or, sbi->s_timeout, oi->i_cred);
1212                 osd_end_request(or);
1213                 goto free_args;
1214         } else {
1215                 args->sbi = sbi;
1216
1217                 ret = exofs_async_op(or, updatei_done, args, oi->i_cred);
1218                 if (ret) {
1219                         osd_end_request(or);
1220                         goto free_args;
1221                 }
1222                 atomic_inc(&sbi->s_curr_pending);
1223                 goto out; /* deallocation in updatei_done */
1224         }
1225
1226 free_args:
1227         kfree(args);
1228 out:
1229         EXOFS_DBGMSG("ret=>%d\n", ret);
1230         return ret;
1231 }
1232
1233 int exofs_write_inode(struct inode *inode, int wait)
1234 {
1235         return exofs_update_inode(inode, wait);
1236 }
1237
1238 /*
1239  * Callback function from exofs_delete_inode() - don't have much cleaning up to
1240  * do.
1241  */
1242 static void delete_done(struct osd_request *or, void *p)
1243 {
1244         struct exofs_sb_info *sbi;
1245         osd_end_request(or);
1246         sbi = p;
1247         atomic_dec(&sbi->s_curr_pending);
1248 }
1249
1250 /*
1251  * Called when the refcount of an inode reaches zero.  We remove the object
1252  * from the OSD here.  We make sure the object was created before we try and
1253  * delete it.
1254  */
1255 void exofs_delete_inode(struct inode *inode)
1256 {
1257         struct exofs_i_info *oi = exofs_i(inode);
1258         struct super_block *sb = inode->i_sb;
1259         struct exofs_sb_info *sbi = sb->s_fs_info;
1260         struct osd_obj_id obj = {sbi->s_pid, inode->i_ino + EXOFS_OBJ_OFF};
1261         struct osd_request *or;
1262         int ret;
1263
1264         truncate_inode_pages(&inode->i_data, 0);
1265
1266         if (is_bad_inode(inode))
1267                 goto no_delete;
1268
1269         mark_inode_dirty(inode);
1270         exofs_update_inode(inode, inode_needs_sync(inode));
1271
1272         inode->i_size = 0;
1273         if (inode->i_blocks)
1274                 exofs_truncate(inode);
1275
1276         clear_inode(inode);
1277
1278         or = osd_start_request(sbi->s_dev, GFP_KERNEL);
1279         if (unlikely(!or)) {
1280                 EXOFS_ERR("exofs_delete_inode: osd_start_request failed\n");
1281                 return;
1282         }
1283
1284         osd_req_remove_object(or, &obj);
1285
1286         /* if we are deleting an obj that hasn't been created yet, wait */
1287         if (!obj_created(oi)) {
1288                 BUG_ON(!obj_2bcreated(oi));
1289                 wait_event(oi->i_wq, obj_created(oi));
1290         }
1291
1292         ret = exofs_async_op(or, delete_done, sbi, oi->i_cred);
1293         if (ret) {
1294                 EXOFS_ERR(
1295                        "ERROR: @exofs_delete_inode exofs_async_op failed\n");
1296                 osd_end_request(or);
1297                 return;
1298         }
1299         atomic_inc(&sbi->s_curr_pending);
1300
1301         return;
1302
1303 no_delete:
1304         clear_inode(inode);
1305 }