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LU-1693 obdfilter: Set bi_rw before calling bio_add_page()
[fs/lustre-release.git] / lustre / osd-ldiskfs / osd_io.c
1 /*
2  * GPL HEADER START
3  *
4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 only,
8  * as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful, but
11  * WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  * General Public License version 2 for more details (a copy is included
14  * in the LICENSE file that accompanied this code).
15  *
16  * You should have received a copy of the GNU General Public License
17  * version 2 along with this program; If not, see
18  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
19  *
20  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
21  * CA 95054 USA or visit www.sun.com if you need additional information or
22  * have any questions.
23  *
24  * GPL HEADER END
25  */
26 /*
27  * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
28  * Use is subject to license terms.
29  *
30  * Copyright (c) 2011, 2012, Whamcloud, Inc.
31  */
32 /*
33  * This file is part of Lustre, http://www.lustre.org/
34  * Lustre is a trademark of Sun Microsystems, Inc.
35  *
36  * lustre/osd/osd_io.c
37  *
38  * body operations
39  *
40  * Author: Nikita Danilov <nikita@clusterfs.com>
41  * Author: Alex Zhuravlev <bzzz@whamcloud.com>
42  *
43  */
44
45 /* LUSTRE_VERSION_CODE */
46 #include <lustre_ver.h>
47 /* prerequisite for linux/xattr.h */
48 #include <linux/types.h>
49 /* prerequisite for linux/xattr.h */
50 #include <linux/fs.h>
51
52 /* ext_depth() */
53 #include <ldiskfs/ldiskfs.h>
54 #include <ldiskfs/ldiskfs_jbd2.h>
55 #include <ldiskfs/ldiskfs_extents.h>
56
57 /*
58  * struct OBD_{ALLOC,FREE}*()
59  * OBD_FAIL_CHECK
60  */
61 #include <obd_support.h>
62
63 #include "osd_internal.h"
64
65 #ifndef HAVE_PAGE_CONSTANT
66 #define mapping_cap_page_constant_write(mapping) 0
67 #define SetPageConstant(page) do {} while (0)
68 #define ClearPageConstant(page) do {} while (0)
69 #endif
70
71 #ifndef HAS_GENERIC_ERROR_REMOVE_PAGE
72 int generic_error_remove_page(struct address_space *mapping, struct page *page)
73 {
74         if (mapping == NULL)
75                 return -EINVAL;
76
77         if (mapping != page->mapping)
78                 return -EIO;
79         /*
80          * Only punch for normal data pages for now.
81          * Handling other types like directories would need more auditing.
82          */
83         if (!S_ISREG(mapping->host->i_mode))
84                 return -EIO;
85
86         if (page_mapped(page)) {
87                 unmap_mapping_range(mapping,
88                                     (loff_t)page->index << PAGE_CACHE_SHIFT,
89                                     PAGE_CACHE_SIZE, 0);
90         }
91         truncate_complete_page(mapping, page);
92         return 0;
93 }
94 #endif
95
96 static void osd_init_iobuf(struct osd_device *d, struct osd_iobuf *iobuf,int rw)
97 {
98         cfs_waitq_init(&iobuf->dr_wait);
99         cfs_atomic_set(&iobuf->dr_numreqs, 0);
100         iobuf->dr_max_pages = PTLRPC_MAX_BRW_PAGES;
101         iobuf->dr_npages = 0;
102         iobuf->dr_error = 0;
103         iobuf->dr_dev = d;
104         iobuf->dr_frags = 0;
105         iobuf->dr_elapsed = 0;
106         /* must be counted before, so assert */
107         LASSERT(iobuf->dr_elapsed_valid == 0);
108         iobuf->dr_rw = rw;
109 }
110
111 static void osd_iobuf_add_page(struct osd_iobuf *iobuf, struct page *page)
112 {
113         LASSERT(iobuf->dr_npages < iobuf->dr_max_pages);
114         iobuf->dr_pages[iobuf->dr_npages++] = page;
115 }
116
117 void osd_fini_iobuf(struct osd_device *d, struct osd_iobuf *iobuf)
118 {
119         int rw = iobuf->dr_rw;
120
121         if (iobuf->dr_elapsed_valid) {
122                 iobuf->dr_elapsed_valid = 0;
123                 LASSERT(iobuf->dr_dev == d);
124                 LASSERT(iobuf->dr_frags > 0);
125                 lprocfs_oh_tally(&d->od_brw_stats.
126                                  hist[BRW_R_DIO_FRAGS+rw],
127                                  iobuf->dr_frags);
128                 lprocfs_oh_tally_log2(&d->od_brw_stats.hist[BRW_R_IO_TIME+rw],
129                                       iobuf->dr_elapsed);
130         }
131 }
132
133 #ifdef HAVE_BIO_ENDIO_2ARG
134 #define DIO_RETURN(a)
135 static void dio_complete_routine(struct bio *bio, int error)
136 #else
137 #define DIO_RETURN(a)   return(a)
138 static int dio_complete_routine(struct bio *bio, unsigned int done, int error)
139 #endif
140 {
141         struct osd_iobuf *iobuf = bio->bi_private;
142         struct bio_vec *bvl;
143         int i;
144
145         /* CAVEAT EMPTOR: possibly in IRQ context
146          * DO NOT record procfs stats here!!! */
147
148         if (unlikely(iobuf == NULL)) {
149                 CERROR("***** bio->bi_private is NULL!  This should never "
150                        "happen.  Normally, I would crash here, but instead I "
151                        "will dump the bio contents to the console.  Please "
152                        "report this to <http://jira.whamcloud.com/> , along "
153                        "with any interesting messages leading up to this point "
154                        "(like SCSI errors, perhaps).  Because bi_private is "
155                        "NULL, I can't wake up the thread that initiated this "
156                        "IO - you will probably have to reboot this node.\n");
157                 CERROR("bi_next: %p, bi_flags: %lx, bi_rw: %lu, bi_vcnt: %d, "
158                        "bi_idx: %d, bi->size: %d, bi_end_io: %p, bi_cnt: %d, "
159                        "bi_private: %p\n", bio->bi_next, bio->bi_flags,
160                        bio->bi_rw, bio->bi_vcnt, bio->bi_idx, bio->bi_size,
161                        bio->bi_end_io, cfs_atomic_read(&bio->bi_cnt),
162                        bio->bi_private);
163                 DIO_RETURN(0);
164         }
165
166         /* the check is outside of the cycle for performance reason -bzzz */
167         if (!cfs_test_bit(BIO_RW, &bio->bi_rw)) {
168                 bio_for_each_segment(bvl, bio, i) {
169                         if (likely(error == 0))
170                                 SetPageUptodate(bvl->bv_page);
171                         LASSERT(PageLocked(bvl->bv_page));
172                         ClearPageConstant(bvl->bv_page);
173                 }
174                 cfs_atomic_dec(&iobuf->dr_dev->od_r_in_flight);
175         } else {
176                 struct page *p = iobuf->dr_pages[0];
177                 if (p->mapping) {
178                         if (mapping_cap_page_constant_write(p->mapping)) {
179                                 bio_for_each_segment(bvl, bio, i) {
180                                         ClearPageConstant(bvl->bv_page);
181                                 }
182                         }
183                 }
184                 cfs_atomic_dec(&iobuf->dr_dev->od_w_in_flight);
185         }
186
187         /* any real error is good enough -bzzz */
188         if (error != 0 && iobuf->dr_error == 0)
189                 iobuf->dr_error = error;
190
191         if (cfs_atomic_dec_and_test(&iobuf->dr_numreqs)) {
192                 iobuf->dr_elapsed = jiffies - iobuf->dr_start_time;
193                 iobuf->dr_elapsed_valid = 1;
194                 cfs_waitq_signal(&iobuf->dr_wait);
195         }
196
197         /* Completed bios used to be chained off iobuf->dr_bios and freed in
198          * filter_clear_dreq().  It was then possible to exhaust the biovec-256
199          * mempool when serious on-disk fragmentation was encountered,
200          * deadlocking the OST.  The bios are now released as soon as complete
201          * so the pool cannot be exhausted while IOs are competing. bug 10076 */
202         bio_put(bio);
203         DIO_RETURN(0);
204 }
205
206 static void record_start_io(struct osd_iobuf *iobuf, int size)
207 {
208         struct osd_device    *osd = iobuf->dr_dev;
209         struct obd_histogram *h = osd->od_brw_stats.hist;
210
211         iobuf->dr_frags++;
212         cfs_atomic_inc(&iobuf->dr_numreqs);
213
214         if (iobuf->dr_rw == 0) {
215                 cfs_atomic_inc(&osd->od_r_in_flight);
216                 lprocfs_oh_tally(&h[BRW_R_RPC_HIST],
217                                  cfs_atomic_read(&osd->od_r_in_flight));
218                 lprocfs_oh_tally_log2(&h[BRW_R_DISK_IOSIZE], size);
219         } else if (iobuf->dr_rw == 1) {
220                 cfs_atomic_inc(&osd->od_w_in_flight);
221                 lprocfs_oh_tally(&h[BRW_W_RPC_HIST],
222                                  cfs_atomic_read(&osd->od_w_in_flight));
223                 lprocfs_oh_tally_log2(&h[BRW_W_DISK_IOSIZE], size);
224         } else {
225                 LBUG();
226         }
227 }
228
229 static void osd_submit_bio(int rw, struct bio *bio)
230 {
231         LASSERTF(rw == 0 || rw == 1, "%x\n", rw);
232         if (rw == 0)
233                 submit_bio(READ, bio);
234         else
235                 submit_bio(WRITE, bio);
236 }
237
238 static int can_be_merged(struct bio *bio, sector_t sector)
239 {
240         unsigned int size;
241
242         if (!bio)
243                 return 0;
244
245         size = bio->bi_size >> 9;
246         return bio->bi_sector + size == sector ? 1 : 0;
247 }
248
249 static int osd_do_bio(struct osd_device *osd, struct inode *inode,
250                       struct osd_iobuf *iobuf)
251 {
252         int            blocks_per_page = CFS_PAGE_SIZE >> inode->i_blkbits;
253         struct page  **pages = iobuf->dr_pages;
254         int            npages = iobuf->dr_npages;
255         unsigned long *blocks = iobuf->dr_blocks;
256         int            total_blocks = npages * blocks_per_page;
257         int            sector_bits = inode->i_sb->s_blocksize_bits - 9;
258         unsigned int   blocksize = inode->i_sb->s_blocksize;
259         struct bio    *bio = NULL;
260         struct page   *page;
261         unsigned int   page_offset;
262         sector_t       sector;
263         int            nblocks;
264         int            block_idx;
265         int            page_idx;
266         int            i;
267         int            rc = 0;
268         ENTRY;
269
270         LASSERT(iobuf->dr_npages == npages);
271
272         osd_brw_stats_update(osd, iobuf);
273         iobuf->dr_start_time = cfs_time_current();
274
275         for (page_idx = 0, block_idx = 0;
276              page_idx < npages;
277              page_idx++, block_idx += blocks_per_page) {
278
279                 page = pages[page_idx];
280                 LASSERT(block_idx + blocks_per_page <= total_blocks);
281
282                 for (i = 0, page_offset = 0;
283                      i < blocks_per_page;
284                      i += nblocks, page_offset += blocksize * nblocks) {
285
286                         nblocks = 1;
287
288                         if (blocks[block_idx + i] == 0) {  /* hole */
289                                 LASSERTF(iobuf->dr_rw == 0,
290                                          "page_idx %u, block_idx %u, i %u\n",
291                                          page_idx, block_idx, i);
292                                 memset(kmap(page) + page_offset, 0, blocksize);
293                                 kunmap(page);
294                                 continue;
295                         }
296
297                         sector = (sector_t)blocks[block_idx + i] << sector_bits;
298
299                         /* Additional contiguous file blocks? */
300                         while (i + nblocks < blocks_per_page &&
301                                (sector + (nblocks << sector_bits)) ==
302                                ((sector_t)blocks[block_idx + i + nblocks] <<
303                                 sector_bits))
304                                 nblocks++;
305
306                         /* I only set the page to be constant only if it
307                          * is mapped to a contiguous underlying disk block(s).
308                          * It will then make sure the corresponding device
309                          * cache of raid5 will be overwritten by this page.
310                          * - jay */
311                         if (iobuf->dr_rw && (nblocks == blocks_per_page) &&
312                             mapping_cap_page_constant_write(inode->i_mapping))
313                                 SetPageConstant(page);
314
315                         if (bio != NULL &&
316                             can_be_merged(bio, sector) &&
317                             bio_add_page(bio, page,
318                                          blocksize * nblocks, page_offset) != 0)
319                                 continue;       /* added this frag OK */
320
321                         if (bio != NULL) {
322                                 struct request_queue *q =
323                                         bdev_get_queue(bio->bi_bdev);
324
325                                 /* Dang! I have to fragment this I/O */
326                                 CDEBUG(D_INODE, "bio++ sz %d vcnt %d(%d) "
327                                        "sectors %d(%d) psg %d(%d) hsg %d(%d)\n",
328                                        bio->bi_size,
329                                        bio->bi_vcnt, bio->bi_max_vecs,
330                                        bio->bi_size >> 9, queue_max_sectors(q),
331                                        bio_phys_segments(q, bio),
332                                        queue_max_phys_segments(q),
333                                        bio_hw_segments(q, bio),
334                                        queue_max_hw_segments(q));
335
336                                 record_start_io(iobuf, bio->bi_size);
337                                 osd_submit_bio(iobuf->dr_rw, bio);
338                         }
339
340                         /* allocate new bio, limited by max BIO size, b=9945 */
341                         bio = bio_alloc(GFP_NOIO, max(BIO_MAX_PAGES,
342                                                       (npages - page_idx) *
343                                                       blocks_per_page));
344                         if (bio == NULL) {
345                                 CERROR("Can't allocate bio %u*%u = %u pages\n",
346                                        (npages - page_idx), blocks_per_page,
347                                        (npages - page_idx) * blocks_per_page);
348                                 rc = -ENOMEM;
349                                 goto out;
350                         }
351
352                         bio->bi_bdev = inode->i_sb->s_bdev;
353                         bio->bi_sector = sector;
354                         bio->bi_rw = (iobuf->dr_rw == 0) ? READ : WRITE;
355                         bio->bi_end_io = dio_complete_routine;
356                         bio->bi_private = iobuf;
357
358                         rc = bio_add_page(bio, page,
359                                           blocksize * nblocks, page_offset);
360                         LASSERT(rc != 0);
361                 }
362         }
363
364         if (bio != NULL) {
365                 record_start_io(iobuf, bio->bi_size);
366                 osd_submit_bio(iobuf->dr_rw, bio);
367                 rc = 0;
368         }
369
370  out:
371         /* in order to achieve better IO throughput, we don't wait for writes
372          * completion here. instead we proceed with transaction commit in
373          * parallel and wait for IO completion once transaction is stopped
374          * see osd_trans_stop() for more details -bzzz */
375         if (iobuf->dr_rw == 0) {
376                 cfs_wait_event(iobuf->dr_wait,
377                                cfs_atomic_read(&iobuf->dr_numreqs) == 0);
378         }
379
380         if (rc == 0)
381                 rc = iobuf->dr_error;
382         RETURN(rc);
383 }
384
385 static int osd_map_remote_to_local(loff_t offset, ssize_t len, int *nrpages,
386                                    struct niobuf_local *lnb)
387 {
388         ENTRY;
389
390         *nrpages = 0;
391
392         while (len > 0) {
393                 int poff = offset & (CFS_PAGE_SIZE - 1);
394                 int plen = CFS_PAGE_SIZE - poff;
395
396                 if (plen > len)
397                         plen = len;
398                 lnb->offset = offset;
399                 /* lnb->lnb_page_offset = poff; */
400                 lnb->len = plen;
401                 /* lb->flags = rnb->flags; */
402                 lnb->flags = 0;
403                 lnb->page = NULL;
404                 lnb->rc = 0;
405
406                 LASSERTF(plen <= len, "plen %u, len %lld\n", plen,
407                          (long long) len);
408                 offset += plen;
409                 len -= plen;
410                 lnb++;
411                 (*nrpages)++;
412         }
413
414         RETURN(0);
415 }
416
417 struct page *osd_get_page(struct dt_object *dt, loff_t offset, int rw)
418 {
419         struct inode      *inode = osd_dt_obj(dt)->oo_inode;
420         struct osd_device *d = osd_obj2dev(osd_dt_obj(dt));
421         struct page       *page;
422
423         LASSERT(inode);
424
425         page = find_or_create_page(inode->i_mapping, offset >> CFS_PAGE_SHIFT,
426                                    GFP_NOFS | __GFP_HIGHMEM);
427         if (unlikely(page == NULL))
428                 lprocfs_counter_add(d->od_stats, LPROC_OSD_NO_PAGE, 1);
429
430         return page;
431 }
432
433 /*
434  * there are following "locks":
435  * journal_start
436  * i_alloc_sem
437  * i_mutex
438  * page lock
439
440  * osd write path
441     * lock page(s)
442     * journal_start
443     * truncate_sem
444
445  * ext4 vmtruncate:
446     * lock pages, unlock
447     * journal_start
448     * lock partial page
449     * i_data_sem
450
451 */
452 int osd_bufs_get(const struct lu_env *env, struct dt_object *d, loff_t pos,
453                  ssize_t len, struct niobuf_local *lnb, int rw,
454                  struct lustre_capa *capa)
455 {
456         struct osd_object   *obj    = osd_dt_obj(d);
457         int npages, i, rc = 0;
458
459         LASSERT(obj->oo_inode);
460
461         osd_map_remote_to_local(pos, len, &npages, lnb);
462
463         for (i = 0; i < npages; i++, lnb++) {
464
465                 /* We still set up for ungranted pages so that granted pages
466                  * can be written to disk as they were promised, and portals
467                  * needs to keep the pages all aligned properly. */
468                 lnb->dentry = (void *) obj;
469
470                 lnb->page = osd_get_page(d, lnb->offset, rw);
471                 if (lnb->page == NULL)
472                         GOTO(cleanup, rc = -ENOMEM);
473
474                 /* DLM locking protects us from write and truncate competing
475                  * for same region, but truncate can leave dirty page in the
476                  * cache. it's possible the writeout on a such a page is in
477                  * progress when we access it. it's also possible that during
478                  * this writeout we put new (partial) data, but then won't
479                  * be able to proceed in filter_commitrw_write(). thus let's
480                  * just wait for writeout completion, should be rare enough.
481                  * -bzzz */
482                 wait_on_page_writeback(lnb->page);
483                 BUG_ON(PageWriteback(lnb->page));
484
485                 lu_object_get(&d->do_lu);
486         }
487         rc = i;
488
489 cleanup:
490         RETURN(rc);
491 }
492
493 static int osd_bufs_put(const struct lu_env *env, struct dt_object *dt,
494                         struct niobuf_local *lnb, int npages)
495 {
496         struct osd_thread_info *oti = osd_oti_get(env);
497         struct osd_iobuf       *iobuf = &oti->oti_iobuf;
498         struct osd_device      *d = osd_obj2dev(osd_dt_obj(dt));
499         int                     i;
500
501         /* to do IO stats, notice we do this here because
502          * osd_do_bio() doesn't wait for write to complete */
503         osd_fini_iobuf(d, iobuf);
504
505         for (i = 0; i < npages; i++) {
506                 if (lnb[i].page == NULL)
507                         continue;
508                 LASSERT(PageLocked(lnb[i].page));
509                 unlock_page(lnb[i].page);
510                 page_cache_release(lnb[i].page);
511                 lu_object_put(env, &dt->do_lu);
512                 lnb[i].page = NULL;
513         }
514         RETURN(0);
515 }
516
517 static int osd_write_prep(const struct lu_env *env, struct dt_object *dt,
518                           struct niobuf_local *lnb, int npages)
519 {
520         struct osd_thread_info *oti   = osd_oti_get(env);
521         struct osd_iobuf       *iobuf = &oti->oti_iobuf;
522         struct inode           *inode = osd_dt_obj(dt)->oo_inode;
523         struct osd_device      *osd   = osd_obj2dev(osd_dt_obj(dt));
524         struct timeval          start;
525         struct timeval          end;
526         unsigned long           timediff;
527         ssize_t                 isize;
528         __s64                   maxidx;
529         int                     rc = 0;
530         int                     i;
531         int                     cache = 0;
532
533         LASSERT(inode);
534
535         osd_init_iobuf(osd, iobuf, 0);
536
537         isize = i_size_read(inode);
538         maxidx = ((isize + CFS_PAGE_SIZE - 1) >> CFS_PAGE_SHIFT) - 1;
539
540         if (osd->od_writethrough_cache)
541                 cache = 1;
542         if (isize > osd->od_readcache_max_filesize)
543                 cache = 0;
544
545         cfs_gettimeofday(&start);
546         for (i = 0; i < npages; i++) {
547
548                 if (cache == 0)
549                         generic_error_remove_page(inode->i_mapping,
550                                                   lnb[i].page);
551
552                 /*
553                  * till commit the content of the page is undefined
554                  * we'll set it uptodate once bulk is done. otherwise
555                  * subsequent reads can access non-stable data
556                  */
557                 ClearPageUptodate(lnb[i].page);
558
559                 if (lnb[i].len == CFS_PAGE_SIZE)
560                         continue;
561
562                 if (maxidx >= lnb[i].page->index) {
563                         osd_iobuf_add_page(iobuf, lnb[i].page);
564                 } else {
565                         long off;
566                         char *p = kmap(lnb[i].page);
567
568                         off = lnb[i].offset;
569                         if (off)
570                                 memset(p, 0, off);
571                         off = lnb[i].offset + lnb[i].len;
572                         off &= ~CFS_PAGE_MASK;
573                         if (off)
574                                 memset(p + off, 0, CFS_PAGE_SIZE - off);
575                         kunmap(lnb[i].page);
576                 }
577         }
578         cfs_gettimeofday(&end);
579         timediff = cfs_timeval_sub(&end, &start, NULL);
580         lprocfs_counter_add(osd->od_stats, LPROC_OSD_GET_PAGE, timediff);
581
582         if (iobuf->dr_npages) {
583                 rc = osd->od_fsops->fs_map_inode_pages(inode, iobuf->dr_pages,
584                                                        iobuf->dr_npages,
585                                                        iobuf->dr_blocks,
586                                                        oti->oti_created,
587                                                        0, NULL);
588                 if (likely(rc == 0)) {
589                         rc = osd_do_bio(osd, inode, iobuf);
590                         /* do IO stats for preparation reads */
591                         osd_fini_iobuf(osd, iobuf);
592                 }
593         }
594         RETURN(rc);
595 }
596
597 static int osd_declare_write_commit(const struct lu_env *env,
598                                     struct dt_object *dt,
599                                     struct niobuf_local *lnb, int npages,
600                                     struct thandle *handle)
601 {
602         const struct osd_device *osd = osd_obj2dev(osd_dt_obj(dt));
603         struct inode            *inode = osd_dt_obj(dt)->oo_inode;
604         struct osd_thandle      *oh;
605         int                      extents = 1;
606         int                      depth;
607         int                      i;
608         int                      newblocks;
609         int                      old;
610
611         LASSERT(handle != NULL);
612         oh = container_of0(handle, struct osd_thandle, ot_super);
613         LASSERT(oh->ot_handle == NULL);
614
615         old = oh->ot_credits;
616         newblocks = npages;
617
618         /* calculate number of extents (probably better to pass nb) */
619         for (i = 1; i < npages; i++)
620                 if (lnb[i].offset !=
621                     lnb[i - 1].offset + lnb[i - 1].len)
622                         extents++;
623
624         /*
625          * each extent can go into new leaf causing a split
626          * 5 is max tree depth: inode + 4 index blocks
627          * with blockmaps, depth is 3 at most
628          */
629         if (LDISKFS_I(inode)->i_flags & LDISKFS_EXTENTS_FL) {
630                 /*
631                  * many concurrent threads may grow tree by the time
632                  * our transaction starts. so, consider 2 is a min depth
633                  */
634                 depth = ext_depth(inode);
635                 depth = max(depth, 1) + 1;
636                 newblocks += depth;
637                 oh->ot_credits++; /* inode */
638                 oh->ot_credits += depth * 2 * extents;
639         } else {
640                 depth = 3;
641                 newblocks += depth;
642                 oh->ot_credits++; /* inode */
643                 oh->ot_credits += depth * extents;
644         }
645
646         /* each new block can go in different group (bitmap + gd) */
647
648         /* we can't dirty more bitmap blocks than exist */
649         if (newblocks > LDISKFS_SB(osd_sb(osd))->s_groups_count)
650                 oh->ot_credits += LDISKFS_SB(osd_sb(osd))->s_groups_count;
651         else
652                 oh->ot_credits += newblocks;
653
654         /* we can't dirty more gd blocks than exist */
655         if (newblocks > LDISKFS_SB(osd_sb(osd))->s_gdb_count)
656                 oh->ot_credits += LDISKFS_SB(osd_sb(osd))->s_gdb_count;
657         else
658                 oh->ot_credits += newblocks;
659
660         RETURN(0);
661 }
662
663 /* Check if a block is allocated or not */
664 static int osd_is_mapped(struct inode *inode, obd_size offset)
665 {
666         sector_t (*fs_bmap)(struct address_space *, sector_t);
667
668         fs_bmap = inode->i_mapping->a_ops->bmap;
669
670         /* We can't know if we are overwriting or not */
671         if (fs_bmap == NULL)
672                 return 0;
673
674         if (fs_bmap(inode->i_mapping, offset >> inode->i_blkbits) == 0)
675                 return 0;
676
677         return 1;
678 }
679
680 static int osd_write_commit(const struct lu_env *env, struct dt_object *dt,
681                             struct niobuf_local *lnb, int npages,
682                             struct thandle *thandle)
683 {
684         struct osd_thread_info *oti = osd_oti_get(env);
685         struct osd_iobuf *iobuf = &oti->oti_iobuf;
686         struct inode *inode = osd_dt_obj(dt)->oo_inode;
687         struct osd_device  *osd = osd_obj2dev(osd_dt_obj(dt));
688         loff_t isize;
689         int rc = 0, i;
690
691         LASSERT(inode);
692
693         osd_init_iobuf(osd, iobuf, 1);
694         isize = i_size_read(inode);
695
696         for (i = 0; i < npages; i++) {
697                 if (lnb[i].rc == -ENOSPC &&
698                     osd_is_mapped(inode, lnb[i].offset)) {
699                         /* Allow the write to proceed if overwriting an
700                          * existing block */
701                         lnb[i].rc = 0;
702                 }
703
704                 if (lnb[i].rc) { /* ENOSPC, network RPC error, etc. */
705                         CDEBUG(D_INODE, "Skipping [%d] == %d\n", i,
706                                lnb[i].rc);
707                         LASSERT(lnb[i].page);
708                         generic_error_remove_page(inode->i_mapping,lnb[i].page);
709                         continue;
710                 }
711
712                 LASSERT(PageLocked(lnb[i].page));
713                 LASSERT(!PageWriteback(lnb[i].page));
714
715                 if (lnb[i].offset + lnb[i].len > isize)
716                         isize = lnb[i].offset + lnb[i].len;
717
718                 /*
719                  * Since write and truncate are serialized by oo_sem, even
720                  * partial-page truncate should not leave dirty pages in the
721                  * page cache.
722                  */
723                 LASSERT(!PageDirty(lnb[i].page));
724
725                 SetPageUptodate(lnb[i].page);
726
727                 osd_iobuf_add_page(iobuf, lnb[i].page);
728         }
729
730         if (OBD_FAIL_CHECK(OBD_FAIL_OST_MAPBLK_ENOSPC)) {
731                 rc = -ENOSPC;
732         } else if (iobuf->dr_npages > 0) {
733                 rc = osd->od_fsops->fs_map_inode_pages(inode, iobuf->dr_pages,
734                                                        iobuf->dr_npages,
735                                                        iobuf->dr_blocks,
736                                                        oti->oti_created,
737                                                        1, NULL);
738         } else {
739                 /* no pages to write, no transno is needed */
740                 thandle->th_local = 1;
741         }
742
743         if (likely(rc == 0)) {
744                 if (isize > i_size_read(inode)) {
745                         i_size_write(inode, isize);
746                         LDISKFS_I(inode)->i_disksize = isize;
747                         inode->i_sb->s_op->dirty_inode(inode);
748                 }
749
750                 rc = osd_do_bio(osd, inode, iobuf);
751                 /* we don't do stats here as in read path because
752                  * write is async: we'll do this in osd_put_bufs() */
753         }
754
755         if (unlikely(rc != 0)) {
756                 /* if write fails, we should drop pages from the cache */
757                 for (i = 0; i < npages; i++) {
758                         if (lnb[i].page == NULL)
759                                 continue;
760                         LASSERT(PageLocked(lnb[i].page));
761                         generic_error_remove_page(inode->i_mapping,lnb[i].page);
762                 }
763         }
764
765         RETURN(rc);
766 }
767
768 static int osd_read_prep(const struct lu_env *env, struct dt_object *dt,
769                          struct niobuf_local *lnb, int npages)
770 {
771         struct osd_thread_info *oti = osd_oti_get(env);
772         struct osd_iobuf *iobuf = &oti->oti_iobuf;
773         struct inode *inode = osd_dt_obj(dt)->oo_inode;
774         struct osd_device *osd = osd_obj2dev(osd_dt_obj(dt));
775         struct timeval start, end;
776         unsigned long timediff;
777         int rc = 0, i, m = 0, cache = 0;
778
779         LASSERT(inode);
780
781         osd_init_iobuf(osd, iobuf, 0);
782
783         if (osd->od_read_cache)
784                 cache = 1;
785         if (i_size_read(inode) > osd->od_readcache_max_filesize)
786                 cache = 0;
787
788         cfs_gettimeofday(&start);
789         for (i = 0; i < npages; i++) {
790
791                 if (i_size_read(inode) <= lnb[i].offset)
792                         /* If there's no more data, abort early.
793                          * lnb->rc == 0, so it's easy to detect later. */
794                         break;
795
796                 if (i_size_read(inode) <
797                     lnb[i].offset + lnb[i].len - 1)
798                         lnb[i].rc = i_size_read(inode) - lnb[i].offset;
799                 else
800                         lnb[i].rc = lnb[i].len;
801                 m += lnb[i].len;
802
803                 lprocfs_counter_add(osd->od_stats, LPROC_OSD_CACHE_ACCESS, 1);
804                 if (PageUptodate(lnb[i].page)) {
805                         lprocfs_counter_add(osd->od_stats,
806                                             LPROC_OSD_CACHE_HIT, 1);
807                 } else {
808                         lprocfs_counter_add(osd->od_stats,
809                                             LPROC_OSD_CACHE_MISS, 1);
810                         osd_iobuf_add_page(iobuf, lnb[i].page);
811                 }
812                 if (cache == 0)
813                         generic_error_remove_page(inode->i_mapping,lnb[i].page);
814         }
815         cfs_gettimeofday(&end);
816         timediff = cfs_timeval_sub(&end, &start, NULL);
817         lprocfs_counter_add(osd->od_stats, LPROC_OSD_GET_PAGE, timediff);
818
819         if (iobuf->dr_npages) {
820                 rc = osd->od_fsops->fs_map_inode_pages(inode, iobuf->dr_pages,
821                                                        iobuf->dr_npages,
822                                                        iobuf->dr_blocks,
823                                                        oti->oti_created,
824                                                        0, NULL);
825                 rc = osd_do_bio(osd, inode, iobuf);
826
827                 /* IO stats will be done in osd_bufs_put() */
828         }
829
830         RETURN(rc);
831 }
832
833 /*
834  * XXX: Another layering violation for now.
835  *
836  * We don't want to use ->f_op->read methods, because generic file write
837  *
838  *         - serializes on ->i_sem, and
839  *
840  *         - does a lot of extra work like balance_dirty_pages(),
841  *
842  * which doesn't work for globally shared files like /last_rcvd.
843  */
844 static int osd_ldiskfs_readlink(struct inode *inode, char *buffer, int buflen)
845 {
846         struct ldiskfs_inode_info *ei = LDISKFS_I(inode);
847
848         memcpy(buffer, (char *)ei->i_data, buflen);
849
850         return  buflen;
851 }
852
853 int osd_ldiskfs_read(struct inode *inode, void *buf, int size, loff_t *offs)
854 {
855         struct buffer_head *bh;
856         unsigned long block;
857         int osize;
858         int blocksize;
859         int csize;
860         int boffs;
861         int err;
862
863         /* prevent reading after eof */
864         cfs_spin_lock(&inode->i_lock);
865         if (i_size_read(inode) < *offs + size) {
866                 size = i_size_read(inode) - *offs;
867                 cfs_spin_unlock(&inode->i_lock);
868                 if (size < 0) {
869                         CDEBUG(D_EXT2, "size %llu is too short to read @%llu\n",
870                                i_size_read(inode), *offs);
871                         return -EBADR;
872                 } else if (size == 0) {
873                         return 0;
874                 }
875         } else {
876                 cfs_spin_unlock(&inode->i_lock);
877         }
878
879         blocksize = 1 << inode->i_blkbits;
880         osize = size;
881         while (size > 0) {
882                 block = *offs >> inode->i_blkbits;
883                 boffs = *offs & (blocksize - 1);
884                 csize = min(blocksize - boffs, size);
885                 bh = ldiskfs_bread(NULL, inode, block, 0, &err);
886                 if (!bh) {
887                         CERROR("%s: can't read %u@%llu on ino %lu: rc = %d\n",
888                                LDISKFS_SB(inode->i_sb)->s_es->s_volume_name,
889                                csize, *offs, inode->i_ino, err);
890                         return err;
891                 }
892
893                 memcpy(buf, bh->b_data + boffs, csize);
894                 brelse(bh);
895
896                 *offs += csize;
897                 buf += csize;
898                 size -= csize;
899         }
900         return osize;
901 }
902
903 static ssize_t osd_read(const struct lu_env *env, struct dt_object *dt,
904                         struct lu_buf *buf, loff_t *pos,
905                         struct lustre_capa *capa)
906 {
907         struct inode *inode = osd_dt_obj(dt)->oo_inode;
908         int           rc;
909
910         if (osd_object_auth(env, dt, capa, CAPA_OPC_BODY_READ))
911                 RETURN(-EACCES);
912
913         /* Read small symlink from inode body as we need to maintain correct
914          * on-disk symlinks for ldiskfs.
915          */
916         if (S_ISLNK(dt->do_lu.lo_header->loh_attr) &&
917             (buf->lb_len <= sizeof(LDISKFS_I(inode)->i_data)))
918                 rc = osd_ldiskfs_readlink(inode, buf->lb_buf, buf->lb_len);
919         else
920                 rc = osd_ldiskfs_read(inode, buf->lb_buf, buf->lb_len, pos);
921
922         return rc;
923 }
924
925 static ssize_t osd_declare_write(const struct lu_env *env, struct dt_object *dt,
926                                  const loff_t size, loff_t pos,
927                                  struct thandle *handle)
928 {
929         struct osd_thandle *oh;
930         int                 credits;
931
932         LASSERT(handle != NULL);
933
934         oh = container_of0(handle, struct osd_thandle, ot_super);
935         LASSERT(oh->ot_handle == NULL);
936
937         /* XXX: size == 0 or INT_MAX indicating a catalog header update or
938          *      llog write, see comment in mdd_declare_llog_record().
939          *
940          *      This hack will be removed with llog over OSD landing
941          */
942         if (size == DECLARE_LLOG_REWRITE)
943                 credits = 2;
944         else if (size == DECLARE_LLOG_WRITE)
945                 credits = 6;
946         else
947                 credits = osd_dto_credits_noquota[DTO_WRITE_BLOCK];
948
949         OSD_DECLARE_OP(oh, write);
950         oh->ot_credits += credits;
951
952         if (osd_dt_obj(dt)->oo_inode == NULL)
953                 return 0;
954
955         osd_declare_qid(dt, oh, USRQUOTA, osd_dt_obj(dt)->oo_inode->i_uid,
956                         osd_dt_obj(dt)->oo_inode);
957         osd_declare_qid(dt, oh, GRPQUOTA, osd_dt_obj(dt)->oo_inode->i_gid,
958                         osd_dt_obj(dt)->oo_inode);
959         return 0;
960 }
961
962 static int osd_ldiskfs_writelink(struct inode *inode, char *buffer, int buflen)
963 {
964
965         memcpy((char *)&LDISKFS_I(inode)->i_data, (char *)buffer, buflen);
966         LDISKFS_I(inode)->i_disksize = buflen;
967         i_size_write(inode, buflen);
968         inode->i_sb->s_op->dirty_inode(inode);
969
970         return 0;
971 }
972
973 int osd_ldiskfs_write_record(struct inode *inode, void *buf, int bufsize,
974                              int write_NUL, loff_t *offs, handle_t *handle)
975 {
976         struct buffer_head *bh        = NULL;
977         loff_t              offset    = *offs;
978         loff_t              new_size  = i_size_read(inode);
979         unsigned long       block;
980         int                 blocksize = 1 << inode->i_blkbits;
981         int                 err = 0;
982         int                 size;
983         int                 boffs;
984         int                 dirty_inode = 0;
985
986         if (write_NUL) {
987                 /*
988                  * long symlink write does not count the NUL terminator in
989                  * bufsize, we write it, and the inode's file size does not
990                  * count the NUL terminator as well.
991                  */
992                 ((char *)buf)[bufsize] = '\0';
993                 ++bufsize;
994         }
995         while (bufsize > 0) {
996                 if (bh != NULL)
997                         brelse(bh);
998
999                 block = offset >> inode->i_blkbits;
1000                 boffs = offset & (blocksize - 1);
1001                 size = min(blocksize - boffs, bufsize);
1002                 bh = ldiskfs_bread(handle, inode, block, 1, &err);
1003                 if (!bh) {
1004                         CERROR("%s: error reading offset %llu (block %lu): "
1005                                "rc = %d\n",
1006                                inode->i_sb->s_id, offset, block, err);
1007                         break;
1008                 }
1009
1010                 err = ldiskfs_journal_get_write_access(handle, bh);
1011                 if (err) {
1012                         CERROR("journal_get_write_access() returned error %d\n",
1013                                err);
1014                         break;
1015                 }
1016                 LASSERTF(boffs + size <= bh->b_size,
1017                          "boffs %d size %d bh->b_size %lu",
1018                          boffs, size, (unsigned long)bh->b_size);
1019                 memcpy(bh->b_data + boffs, buf, size);
1020                 err = ldiskfs_journal_dirty_metadata(handle, bh);
1021                 if (err)
1022                         break;
1023
1024                 if (offset + size > new_size)
1025                         new_size = offset + size;
1026                 offset += size;
1027                 bufsize -= size;
1028                 buf += size;
1029         }
1030         if (bh)
1031                 brelse(bh);
1032
1033         if (write_NUL)
1034                 --new_size;
1035         /* correct in-core and on-disk sizes */
1036         if (new_size > i_size_read(inode)) {
1037                 cfs_spin_lock(&inode->i_lock);
1038                 if (new_size > i_size_read(inode))
1039                         i_size_write(inode, new_size);
1040                 if (i_size_read(inode) > LDISKFS_I(inode)->i_disksize) {
1041                         LDISKFS_I(inode)->i_disksize = i_size_read(inode);
1042                         dirty_inode = 1;
1043                 }
1044                 cfs_spin_unlock(&inode->i_lock);
1045                 if (dirty_inode)
1046                         inode->i_sb->s_op->dirty_inode(inode);
1047         }
1048
1049         if (err == 0)
1050                 *offs = offset;
1051         return err;
1052 }
1053
1054 static ssize_t osd_write(const struct lu_env *env, struct dt_object *dt,
1055                          const struct lu_buf *buf, loff_t *pos,
1056                          struct thandle *handle, struct lustre_capa *capa,
1057                          int ignore_quota)
1058 {
1059         struct inode            *inode = osd_dt_obj(dt)->oo_inode;
1060         struct osd_thandle      *oh;
1061         ssize_t                 result;
1062 #ifdef HAVE_QUOTA_SUPPORT
1063         cfs_cap_t               save = cfs_curproc_cap_pack();
1064 #endif
1065         int                     is_link;
1066
1067         LASSERT(dt_object_exists(dt));
1068
1069         if (osd_object_auth(env, dt, capa, CAPA_OPC_BODY_WRITE))
1070                 return -EACCES;
1071
1072         LASSERT(handle != NULL);
1073
1074         /* XXX: don't check: one declared chunk can be used many times */
1075         /* OSD_EXEC_OP(handle, write); */
1076
1077         oh = container_of(handle, struct osd_thandle, ot_super);
1078         LASSERT(oh->ot_handle->h_transaction != NULL);
1079 #ifdef HAVE_QUOTA_SUPPORT
1080         if (ignore_quota)
1081                 cfs_cap_raise(CFS_CAP_SYS_RESOURCE);
1082         else
1083                 cfs_cap_lower(CFS_CAP_SYS_RESOURCE);
1084 #endif
1085         /* Write small symlink to inode body as we need to maintain correct
1086          * on-disk symlinks for ldiskfs.
1087          * Note: the buf->lb_buf contains a NUL terminator while buf->lb_len
1088          * does not count it in.
1089          */
1090         is_link = S_ISLNK(dt->do_lu.lo_header->loh_attr);
1091         if (is_link && (buf->lb_len < sizeof(LDISKFS_I(inode)->i_data)))
1092                 result = osd_ldiskfs_writelink(inode, buf->lb_buf, buf->lb_len);
1093         else
1094                 result = osd_ldiskfs_write_record(inode, buf->lb_buf,
1095                                                   buf->lb_len, is_link, pos,
1096                                                   oh->ot_handle);
1097 #ifdef HAVE_QUOTA_SUPPORT
1098         cfs_curproc_cap_unpack(save);
1099 #endif
1100         if (result == 0)
1101                 result = buf->lb_len;
1102         return result;
1103 }
1104
1105 static int osd_declare_punch(const struct lu_env *env, struct dt_object *dt,
1106                              __u64 start, __u64 end, struct thandle *th)
1107 {
1108         struct osd_thandle *oh;
1109         ENTRY;
1110
1111         LASSERT(th);
1112         oh = container_of(th, struct osd_thandle, ot_super);
1113
1114         OSD_DECLARE_OP(oh, punch);
1115
1116         /*
1117          * we don't need to reserve credits for whole truncate
1118          * it's not possible as truncate may need to free too many
1119          * blocks and that won't fit a single transaction. instead
1120          * we reserve credits to change i_size and put inode onto
1121          * orphan list. if needed truncate will extend or restart
1122          * transaction
1123          */
1124         oh->ot_credits += osd_dto_credits_noquota[DTO_ATTR_SET_BASE];
1125         oh->ot_credits += 3;
1126
1127         RETURN(0);
1128 }
1129
1130 static int osd_punch(const struct lu_env *env, struct dt_object *dt,
1131                      __u64 start, __u64 end, struct thandle *th,
1132                      struct lustre_capa *capa)
1133 {
1134         struct osd_thandle *oh;
1135         struct osd_object  *obj = osd_dt_obj(dt);
1136         struct inode       *inode = obj->oo_inode;
1137         handle_t           *h;
1138         tid_t               tid;
1139         int                 rc, rc2 = 0;
1140         ENTRY;
1141
1142         LASSERT(end == OBD_OBJECT_EOF);
1143         LASSERT(dt_object_exists(dt));
1144         LASSERT(osd_invariant(obj));
1145
1146         LASSERT(th);
1147         oh = container_of(th, struct osd_thandle, ot_super);
1148         LASSERT(oh->ot_handle->h_transaction != NULL);
1149
1150         OSD_EXEC_OP(th, punch);
1151
1152         tid = oh->ot_handle->h_transaction->t_tid;
1153
1154         rc = vmtruncate(inode, start);
1155
1156         /*
1157          * For a partial-page truncate, flush the page to disk immediately to
1158          * avoid data corruption during direct disk write.  b=17397
1159          */
1160         if (rc == 0 && (start & ~CFS_PAGE_MASK) != 0)
1161                 rc = filemap_fdatawrite_range(inode->i_mapping, start, start+1);
1162
1163         h = journal_current_handle();
1164         LASSERT(h != NULL);
1165         LASSERT(h == oh->ot_handle);
1166
1167         if (tid != h->h_transaction->t_tid) {
1168                 int credits = oh->ot_credits;
1169                 /*
1170                  * transaction has changed during truncate
1171                  * we need to restart the handle with our credits
1172                  */
1173                 if (h->h_buffer_credits < credits) {
1174                         if (ldiskfs_journal_extend(h, credits))
1175                                 rc2 = ldiskfs_journal_restart(h, credits);
1176                 }
1177         }
1178
1179         RETURN(rc == 0 ? rc2 : rc);
1180 }
1181
1182 static int osd_fiemap_get(const struct lu_env *env, struct dt_object *dt,
1183                           struct ll_user_fiemap *fm)
1184 {
1185         struct inode *inode = osd_dt_obj(dt)->oo_inode;
1186         struct osd_thread_info *info   = osd_oti_get(env);
1187         struct dentry          *dentry = &info->oti_obj_dentry;
1188         struct file            *file   = &info->oti_file;
1189         mm_segment_t            saved_fs;
1190         int rc;
1191
1192         LASSERT(inode);
1193         dentry->d_inode = inode;
1194         file->f_dentry = dentry;
1195         file->f_mapping = inode->i_mapping;
1196         file->f_op = inode->i_fop;
1197
1198         saved_fs = get_fs();
1199         set_fs(get_ds());
1200         /* ldiskfs_ioctl does not have a inode argument */
1201         if (inode->i_fop->unlocked_ioctl)
1202                 rc = inode->i_fop->unlocked_ioctl(file, FSFILT_IOC_FIEMAP,
1203                                                   (long)fm);
1204         else
1205                 rc = -ENOTTY;
1206         set_fs(saved_fs);
1207         return rc;
1208 }
1209
1210 /*
1211  * in some cases we may need declare methods for objects being created
1212  * e.g., when we create symlink
1213  */
1214 const struct dt_body_operations osd_body_ops_new = {
1215         .dbo_declare_write = osd_declare_write,
1216 };
1217
1218 const struct dt_body_operations osd_body_ops = {
1219         .dbo_read                 = osd_read,
1220         .dbo_declare_write        = osd_declare_write,
1221         .dbo_write                = osd_write,
1222         .dbo_bufs_get             = osd_bufs_get,
1223         .dbo_bufs_put             = osd_bufs_put,
1224         .dbo_write_prep           = osd_write_prep,
1225         .dbo_declare_write_commit = osd_declare_write_commit,
1226         .dbo_write_commit         = osd_write_commit,
1227         .dbo_read_prep            = osd_read_prep,
1228         .do_declare_punch         = osd_declare_punch,
1229         .do_punch                 = osd_punch,
1230         .dbo_fiemap_get           = osd_fiemap_get,
1231 };
1232