1 #include "ceph_debug.h"
3 #include <linux/backing-dev.h>
6 #include <linux/pagemap.h>
7 #include <linux/writeback.h> /* generic_writepages */
8 #include <linux/pagevec.h>
9 #include <linux/task_io_accounting_ops.h>
12 #include "osd_client.h"
15 * Ceph address space ops.
17 * There are a few funny things going on here.
19 * The page->private field is used to reference a struct
20 * ceph_snap_context for _every_ dirty page. This indicates which
21 * snapshot the page was logically dirtied in, and thus which snap
22 * context needs to be associated with the osd write during writeback.
24 * Similarly, struct ceph_inode_info maintains a set of counters to
25 * count dirty pages on the inode. In the absense of snapshots,
26 * i_wrbuffer_ref == i_wrbuffer_ref_head == the dirty page count.
28 * When a snapshot is taken (that is, when the client receives
29 * notification that a snapshot was taken), each inode with caps and
30 * with dirty pages (dirty pages implies there is a cap) gets a new
31 * ceph_cap_snap in the i_cap_snaps list (which is sorted in ascending
32 * order, new snaps go to the tail). The i_wrbuffer_ref_head count is
33 * moved to capsnap->dirty. (Unless a sync write is currently in
34 * progress. In that case, the capsnap is said to be "pending", new
35 * writes cannot start, and the capsnap isn't "finalized" until the
36 * write completes (or fails) and a final size/mtime for the inode for
37 * that snap can be settled upon.) i_wrbuffer_ref_head is reset to 0.
39 * On writeback, we must submit writes to the osd IN SNAP ORDER. So,
40 * we look for the first capsnap in i_cap_snaps and write out pages in
41 * that snap context _only_. Then we move on to the next capsnap,
42 * eventually reaching the "live" or "head" context (i.e., pages that
43 * are not yet snapped) and are writing the most recently dirtied
46 * Invalidate and so forth must take care to ensure the dirty page
47 * accounting is preserved.
50 #define CONGESTION_ON_THRESH(congestion_kb) (congestion_kb >> (PAGE_SHIFT-10))
51 #define CONGESTION_OFF_THRESH(congestion_kb) \
52 (CONGESTION_ON_THRESH(congestion_kb) - \
53 (CONGESTION_ON_THRESH(congestion_kb) >> 2))
58 * Dirty a page. Optimistically adjust accounting, on the assumption
59 * that we won't race with invalidate. If we do, readjust.
61 static int ceph_set_page_dirty(struct page
*page
)
63 struct address_space
*mapping
= page
->mapping
;
65 struct ceph_inode_info
*ci
;
67 struct ceph_snap_context
*snapc
;
69 if (unlikely(!mapping
))
70 return !TestSetPageDirty(page
);
72 if (TestSetPageDirty(page
)) {
73 dout("%p set_page_dirty %p idx %lu -- already dirty\n",
74 mapping
->host
, page
, page
->index
);
78 inode
= mapping
->host
;
79 ci
= ceph_inode(inode
);
82 * Note that we're grabbing a snapc ref here without holding
85 snapc
= ceph_get_snap_context(ci
->i_snap_realm
->cached_context
);
88 spin_lock(&inode
->i_lock
);
89 if (ci
->i_wrbuffer_ref_head
== 0)
90 ci
->i_head_snapc
= ceph_get_snap_context(snapc
);
91 ++ci
->i_wrbuffer_ref_head
;
92 if (ci
->i_wrbuffer_ref
== 0)
95 dout("%p set_page_dirty %p idx %lu head %d/%d -> %d/%d "
96 "snapc %p seq %lld (%d snaps)\n",
97 mapping
->host
, page
, page
->index
,
98 ci
->i_wrbuffer_ref
-1, ci
->i_wrbuffer_ref_head
-1,
99 ci
->i_wrbuffer_ref
, ci
->i_wrbuffer_ref_head
,
100 snapc
, snapc
->seq
, snapc
->num_snaps
);
101 spin_unlock(&inode
->i_lock
);
103 /* now adjust page */
104 spin_lock_irq(&mapping
->tree_lock
);
105 if (page
->mapping
) { /* Race with truncate? */
106 WARN_ON_ONCE(!PageUptodate(page
));
108 if (mapping_cap_account_dirty(mapping
)) {
109 __inc_zone_page_state(page
, NR_FILE_DIRTY
);
110 __inc_bdi_stat(mapping
->backing_dev_info
,
112 task_io_account_write(PAGE_CACHE_SIZE
);
114 radix_tree_tag_set(&mapping
->page_tree
,
115 page_index(page
), PAGECACHE_TAG_DIRTY
);
118 * Reference snap context in page->private. Also set
119 * PagePrivate so that we get invalidatepage callback.
121 page
->private = (unsigned long)snapc
;
122 SetPagePrivate(page
);
124 dout("ANON set_page_dirty %p (raced truncate?)\n", page
);
128 spin_unlock_irq(&mapping
->tree_lock
);
131 /* whoops, we failed to dirty the page */
132 ceph_put_wrbuffer_cap_refs(ci
, 1, snapc
);
134 __mark_inode_dirty(mapping
->host
, I_DIRTY_PAGES
);
136 BUG_ON(!PageDirty(page
));
141 * If we are truncating the full page (i.e. offset == 0), adjust the
142 * dirty page counters appropriately. Only called if there is private
145 static void ceph_invalidatepage(struct page
*page
, unsigned long offset
)
148 struct ceph_inode_info
*ci
;
149 struct ceph_snap_context
*snapc
= (void *)page
->private;
151 BUG_ON(!PageLocked(page
));
152 BUG_ON(!page
->private);
153 BUG_ON(!PagePrivate(page
));
154 BUG_ON(!page
->mapping
);
156 inode
= page
->mapping
->host
;
159 * We can get non-dirty pages here due to races between
160 * set_page_dirty and truncate_complete_page; just spit out a
161 * warning, in case we end up with accounting problems later.
163 if (!PageDirty(page
))
164 pr_err("%p invalidatepage %p page not dirty\n", inode
, page
);
167 ClearPageChecked(page
);
169 ci
= ceph_inode(inode
);
171 dout("%p invalidatepage %p idx %lu full dirty page %lu\n",
172 inode
, page
, page
->index
, offset
);
173 ceph_put_wrbuffer_cap_refs(ci
, 1, snapc
);
174 ceph_put_snap_context(snapc
);
176 ClearPagePrivate(page
);
178 dout("%p invalidatepage %p idx %lu partial dirty page\n",
179 inode
, page
, page
->index
);
183 /* just a sanity check */
184 static int ceph_releasepage(struct page
*page
, gfp_t g
)
186 struct inode
*inode
= page
->mapping
? page
->mapping
->host
: NULL
;
187 dout("%p releasepage %p idx %lu\n", inode
, page
, page
->index
);
188 WARN_ON(PageDirty(page
));
189 WARN_ON(page
->private);
190 WARN_ON(PagePrivate(page
));
195 * read a single page, without unlocking it.
197 static int readpage_nounlock(struct file
*filp
, struct page
*page
)
199 struct inode
*inode
= filp
->f_dentry
->d_inode
;
200 struct ceph_inode_info
*ci
= ceph_inode(inode
);
201 struct ceph_osd_client
*osdc
= &ceph_inode_to_client(inode
)->osdc
;
203 u64 len
= PAGE_CACHE_SIZE
;
205 dout("readpage inode %p file %p page %p index %lu\n",
206 inode
, filp
, page
, page
->index
);
207 err
= ceph_osdc_readpages(osdc
, ceph_vino(inode
), &ci
->i_layout
,
208 page
->index
<< PAGE_CACHE_SHIFT
, &len
,
209 ci
->i_truncate_seq
, ci
->i_truncate_size
,
216 } else if (err
< PAGE_CACHE_SIZE
) {
217 /* zero fill remainder of page */
218 zero_user_segment(page
, err
, PAGE_CACHE_SIZE
);
220 SetPageUptodate(page
);
223 return err
< 0 ? err
: 0;
226 static int ceph_readpage(struct file
*filp
, struct page
*page
)
228 int r
= readpage_nounlock(filp
, page
);
234 * Build a vector of contiguous pages from the provided page list.
236 static struct page
**page_vector_from_list(struct list_head
*page_list
,
241 int next_index
, contig_pages
= 0;
243 /* build page vector */
244 pages
= kmalloc(sizeof(*pages
) * *nr_pages
, GFP_NOFS
);
246 return ERR_PTR(-ENOMEM
);
248 BUG_ON(list_empty(page_list
));
249 next_index
= list_entry(page_list
->prev
, struct page
, lru
)->index
;
250 list_for_each_entry_reverse(page
, page_list
, lru
) {
251 if (page
->index
== next_index
) {
252 dout("readpages page %d %p\n", contig_pages
, page
);
253 pages
[contig_pages
] = page
;
260 *nr_pages
= contig_pages
;
265 * Read multiple pages. Leave pages we don't read + unlock in page_list;
266 * the caller (VM) cleans them up.
268 static int ceph_readpages(struct file
*file
, struct address_space
*mapping
,
269 struct list_head
*page_list
, unsigned nr_pages
)
271 struct inode
*inode
= file
->f_dentry
->d_inode
;
272 struct ceph_inode_info
*ci
= ceph_inode(inode
);
273 struct ceph_osd_client
*osdc
= &ceph_inode_to_client(inode
)->osdc
;
280 dout("readpages %p file %p nr_pages %d\n",
281 inode
, file
, nr_pages
);
283 pages
= page_vector_from_list(page_list
, &nr_pages
);
285 return PTR_ERR(pages
);
287 /* guess read extent */
288 offset
= pages
[0]->index
<< PAGE_CACHE_SHIFT
;
289 len
= nr_pages
<< PAGE_CACHE_SHIFT
;
290 rc
= ceph_osdc_readpages(osdc
, ceph_vino(inode
), &ci
->i_layout
,
292 ci
->i_truncate_seq
, ci
->i_truncate_size
,
299 /* set uptodate and add to lru in pagevec-sized chunks */
300 pagevec_init(&pvec
, 0);
301 for (; !list_empty(page_list
) && len
> 0;
302 rc
-= PAGE_CACHE_SIZE
, len
-= PAGE_CACHE_SIZE
) {
304 list_entry(page_list
->prev
, struct page
, lru
);
306 list_del(&page
->lru
);
308 if (rc
< (int)PAGE_CACHE_SIZE
) {
309 /* zero (remainder of) page */
310 int s
= rc
< 0 ? 0 : rc
;
311 zero_user_segment(page
, s
, PAGE_CACHE_SIZE
);
314 if (add_to_page_cache(page
, mapping
, page
->index
, GFP_NOFS
)) {
315 page_cache_release(page
);
316 dout("readpages %p add_to_page_cache failed %p\n",
320 dout("readpages %p adding %p idx %lu\n", inode
, page
,
322 flush_dcache_page(page
);
323 SetPageUptodate(page
);
325 if (pagevec_add(&pvec
, page
) == 0)
326 pagevec_lru_add_file(&pvec
); /* add to lru */
328 pagevec_lru_add_file(&pvec
);
337 * Get ref for the oldest snapc for an inode with dirty data... that is, the
338 * only snap context we are allowed to write back.
340 * Caller holds i_lock.
342 static struct ceph_snap_context
*__get_oldest_context(struct inode
*inode
,
345 struct ceph_inode_info
*ci
= ceph_inode(inode
);
346 struct ceph_snap_context
*snapc
= NULL
;
347 struct ceph_cap_snap
*capsnap
= NULL
;
349 list_for_each_entry(capsnap
, &ci
->i_cap_snaps
, ci_item
) {
350 dout(" cap_snap %p snapc %p has %d dirty pages\n", capsnap
,
351 capsnap
->context
, capsnap
->dirty_pages
);
352 if (capsnap
->dirty_pages
) {
353 snapc
= ceph_get_snap_context(capsnap
->context
);
355 *snap_size
= capsnap
->size
;
359 if (!snapc
&& ci
->i_snap_realm
) {
360 snapc
= ceph_get_snap_context(ci
->i_snap_realm
->cached_context
);
361 dout(" head snapc %p has %d dirty pages\n",
362 snapc
, ci
->i_wrbuffer_ref_head
);
367 static struct ceph_snap_context
*get_oldest_context(struct inode
*inode
,
370 struct ceph_snap_context
*snapc
= NULL
;
372 spin_lock(&inode
->i_lock
);
373 snapc
= __get_oldest_context(inode
, snap_size
);
374 spin_unlock(&inode
->i_lock
);
379 * Write a single page, but leave the page locked.
381 * If we get a write error, set the page error bit, but still adjust the
382 * dirty page accounting (i.e., page is no longer dirty).
384 static int writepage_nounlock(struct page
*page
, struct writeback_control
*wbc
)
387 struct ceph_inode_info
*ci
;
388 struct ceph_client
*client
;
389 struct ceph_osd_client
*osdc
;
390 loff_t page_off
= page
->index
<< PAGE_CACHE_SHIFT
;
391 int len
= PAGE_CACHE_SIZE
;
394 struct ceph_snap_context
*snapc
;
398 dout("writepage %p idx %lu\n", page
, page
->index
);
400 if (!page
->mapping
|| !page
->mapping
->host
) {
401 dout("writepage %p - no mapping\n", page
);
404 inode
= page
->mapping
->host
;
405 ci
= ceph_inode(inode
);
406 client
= ceph_inode_to_client(inode
);
407 osdc
= &client
->osdc
;
409 /* verify this is a writeable snap context */
410 snapc
= (void *)page
->private;
412 dout("writepage %p page %p not dirty?\n", inode
, page
);
415 if (snapc
!= get_oldest_context(inode
, &snap_size
)) {
416 dout("writepage %p page %p snapc %p not writeable - noop\n",
417 inode
, page
, (void *)page
->private);
418 /* we should only noop if called by kswapd */
419 WARN_ON((current
->flags
& PF_MEMALLOC
) == 0);
423 /* is this a partial page at end of file? */
427 i_size
= i_size_read(inode
);
428 if (i_size
< page_off
+ len
)
429 len
= i_size
- page_off
;
431 dout("writepage %p page %p index %lu on %llu~%u\n",
432 inode
, page
, page
->index
, page_off
, len
);
434 writeback_stat
= atomic_long_inc_return(&client
->writeback_count
);
436 CONGESTION_ON_THRESH(client
->mount_args
->congestion_kb
))
437 set_bdi_congested(&client
->backing_dev_info
, BLK_RW_ASYNC
);
439 set_page_writeback(page
);
440 err
= ceph_osdc_writepages(osdc
, ceph_vino(inode
),
441 &ci
->i_layout
, snapc
,
443 ci
->i_truncate_seq
, ci
->i_truncate_size
,
445 &page
, 1, 0, 0, true);
447 dout("writepage setting page/mapping error %d %p\n", err
, page
);
449 mapping_set_error(&inode
->i_data
, err
);
451 wbc
->pages_skipped
++;
453 dout("writepage cleaned page %p\n", page
);
454 err
= 0; /* vfs expects us to return 0 */
457 ClearPagePrivate(page
);
458 end_page_writeback(page
);
459 ceph_put_wrbuffer_cap_refs(ci
, 1, snapc
);
460 ceph_put_snap_context(snapc
);
465 static int ceph_writepage(struct page
*page
, struct writeback_control
*wbc
)
468 struct inode
*inode
= page
->mapping
->host
;
471 err
= writepage_nounlock(page
, wbc
);
479 * lame release_pages helper. release_pages() isn't exported to
482 static void ceph_release_pages(struct page
**pages
, int num
)
487 pagevec_init(&pvec
, 0);
488 for (i
= 0; i
< num
; i
++) {
489 if (pagevec_add(&pvec
, pages
[i
]) == 0)
490 pagevec_release(&pvec
);
492 pagevec_release(&pvec
);
497 * async writeback completion handler.
499 * If we get an error, set the mapping error bit, but not the individual
502 static void writepages_finish(struct ceph_osd_request
*req
,
503 struct ceph_msg
*msg
)
505 struct inode
*inode
= req
->r_inode
;
506 struct ceph_osd_reply_head
*replyhead
;
507 struct ceph_osd_op
*op
;
508 struct ceph_inode_info
*ci
= ceph_inode(inode
);
512 struct ceph_snap_context
*snapc
= req
->r_snapc
;
513 struct address_space
*mapping
= inode
->i_mapping
;
514 struct writeback_control
*wbc
= req
->r_wbc
;
517 struct ceph_client
*client
= ceph_inode_to_client(inode
);
519 unsigned issued
= __ceph_caps_issued(ci
, NULL
);
522 replyhead
= msg
->front
.iov_base
;
523 WARN_ON(le32_to_cpu(replyhead
->num_ops
) == 0);
524 op
= (void *)(replyhead
+ 1);
525 rc
= le32_to_cpu(replyhead
->result
);
526 bytes
= le64_to_cpu(op
->extent
.length
);
530 * Assume we wrote the pages we originally sent. The
531 * osd might reply with fewer pages if our writeback
532 * raced with a truncation and was adjusted at the osd,
533 * so don't believe the reply.
535 wrote
= req
->r_num_pages
;
538 mapping_set_error(mapping
, rc
);
540 dout("writepages_finish %p rc %d bytes %llu wrote %d (pages)\n",
541 inode
, rc
, bytes
, wrote
);
543 /* clean all pages */
544 for (i
= 0; i
< req
->r_num_pages
; i
++) {
545 page
= req
->r_pages
[i
];
547 WARN_ON(!PageUptodate(page
));
550 atomic_long_dec_return(&client
->writeback_count
);
552 CONGESTION_OFF_THRESH(client
->mount_args
->congestion_kb
))
553 clear_bdi_congested(&client
->backing_dev_info
,
557 dout("inode %p skipping page %p\n", inode
, page
);
558 wbc
->pages_skipped
++;
561 ClearPagePrivate(page
);
562 ceph_put_snap_context(snapc
);
563 dout("unlocking %d %p\n", i
, page
);
564 end_page_writeback(page
);
567 * We lost the cache cap, need to truncate the page before
568 * it is unlocked, otherwise we'd truncate it later in the
569 * page truncation thread, possibly losing some data that
572 if ((issued
& CEPH_CAP_FILE_CACHE
) == 0)
573 generic_error_remove_page(inode
->i_mapping
, page
);
577 dout("%p wrote+cleaned %d pages\n", inode
, wrote
);
578 ceph_put_wrbuffer_cap_refs(ci
, req
->r_num_pages
, snapc
);
580 ceph_release_pages(req
->r_pages
, req
->r_num_pages
);
581 if (req
->r_pages_from_pool
)
582 mempool_free(req
->r_pages
,
583 ceph_client(inode
->i_sb
)->wb_pagevec_pool
);
586 ceph_osdc_put_request(req
);
590 * allocate a page vec, either directly, or if necessary, via a the
591 * mempool. we avoid the mempool if we can because req->r_num_pages
592 * may be less than the maximum write size.
594 static void alloc_page_vec(struct ceph_client
*client
,
595 struct ceph_osd_request
*req
)
597 req
->r_pages
= kmalloc(sizeof(struct page
*) * req
->r_num_pages
,
600 req
->r_pages
= mempool_alloc(client
->wb_pagevec_pool
, GFP_NOFS
);
601 req
->r_pages_from_pool
= 1;
602 WARN_ON(!req
->r_pages
);
607 * initiate async writeback
609 static int ceph_writepages_start(struct address_space
*mapping
,
610 struct writeback_control
*wbc
)
612 struct inode
*inode
= mapping
->host
;
613 struct backing_dev_info
*bdi
= mapping
->backing_dev_info
;
614 struct ceph_inode_info
*ci
= ceph_inode(inode
);
615 struct ceph_client
*client
;
616 pgoff_t index
, start
, end
;
619 pgoff_t max_pages
= 0, max_pages_ever
= 0;
620 struct ceph_snap_context
*snapc
= NULL
, *last_snapc
= NULL
;
624 unsigned wsize
= 1 << inode
->i_blkbits
;
625 struct ceph_osd_request
*req
= NULL
;
630 * Include a 'sync' in the OSD request if this is a data
631 * integrity write (e.g., O_SYNC write or fsync()), or if our
632 * cap is being revoked.
634 do_sync
= wbc
->sync_mode
== WB_SYNC_ALL
;
635 if (ceph_caps_revoking(ci
, CEPH_CAP_FILE_BUFFER
))
637 dout("writepages_start %p dosync=%d (mode=%s)\n",
639 wbc
->sync_mode
== WB_SYNC_NONE
? "NONE" :
640 (wbc
->sync_mode
== WB_SYNC_ALL
? "ALL" : "HOLD"));
642 client
= ceph_inode_to_client(inode
);
643 if (client
->mount_state
== CEPH_MOUNT_SHUTDOWN
) {
644 pr_warning("writepage_start %p on forced umount\n", inode
);
645 return -EIO
; /* we're in a forced umount, don't write! */
647 if (client
->mount_args
->wsize
&& client
->mount_args
->wsize
< wsize
)
648 wsize
= client
->mount_args
->wsize
;
649 if (wsize
< PAGE_CACHE_SIZE
)
650 wsize
= PAGE_CACHE_SIZE
;
651 max_pages_ever
= wsize
>> PAGE_CACHE_SHIFT
;
653 pagevec_init(&pvec
, 0);
656 if (wbc
->nonblocking
&& bdi_write_congested(bdi
)) {
657 dout(" writepages congested\n");
658 wbc
->encountered_congestion
= 1;
662 /* where to start/end? */
663 if (wbc
->range_cyclic
) {
664 start
= mapping
->writeback_index
; /* Start from prev offset */
666 dout(" cyclic, start at %lu\n", start
);
668 start
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
669 end
= wbc
->range_end
>> PAGE_CACHE_SHIFT
;
670 if (wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
)
673 dout(" not cyclic, %lu to %lu\n", start
, end
);
678 /* find oldest snap context with dirty data */
679 ceph_put_snap_context(snapc
);
680 snapc
= get_oldest_context(inode
, &snap_size
);
682 /* hmm, why does writepages get called when there
684 dout(" no snap context with dirty data?\n");
687 dout(" oldest snapc is %p seq %lld (%d snaps)\n",
688 snapc
, snapc
->seq
, snapc
->num_snaps
);
689 if (last_snapc
&& snapc
!= last_snapc
) {
690 /* if we switched to a newer snapc, restart our scan at the
691 * start of the original file range. */
692 dout(" snapc differs from last pass, restarting at %lu\n",
698 while (!done
&& index
<= end
) {
702 int pvec_pages
, locked_pages
;
706 struct ceph_osd_request_head
*reqhead
;
707 struct ceph_osd_op
*op
;
712 max_pages
= max_pages_ever
;
716 want
= min(end
- index
,
717 min((pgoff_t
)PAGEVEC_SIZE
,
718 max_pages
- (pgoff_t
)locked_pages
) - 1)
720 pvec_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
,
723 dout("pagevec_lookup_tag got %d\n", pvec_pages
);
724 if (!pvec_pages
&& !locked_pages
)
726 for (i
= 0; i
< pvec_pages
&& locked_pages
< max_pages
; i
++) {
727 page
= pvec
.pages
[i
];
728 dout("? %p idx %lu\n", page
, page
->index
);
729 if (locked_pages
== 0)
730 lock_page(page
); /* first page */
731 else if (!trylock_page(page
))
734 /* only dirty pages, or our accounting breaks */
735 if (unlikely(!PageDirty(page
)) ||
736 unlikely(page
->mapping
!= mapping
)) {
737 dout("!dirty or !mapping %p\n", page
);
741 if (!wbc
->range_cyclic
&& page
->index
> end
) {
742 dout("end of range %p\n", page
);
747 if (next
&& (page
->index
!= next
)) {
748 dout("not consecutive %p\n", page
);
752 if (wbc
->sync_mode
!= WB_SYNC_NONE
) {
753 dout("waiting on writeback %p\n", page
);
754 wait_on_page_writeback(page
);
756 if ((snap_size
&& page_offset(page
) > snap_size
) ||
758 page_offset(page
) > i_size_read(inode
))) {
759 dout("%p page eof %llu\n", page
, snap_size
?
760 snap_size
: i_size_read(inode
));
765 if (PageWriteback(page
)) {
766 dout("%p under writeback\n", page
);
771 /* only if matching snap context */
772 if (snapc
!= (void *)page
->private) {
773 dout("page snapc %p != oldest %p\n",
774 (void *)page
->private, snapc
);
777 continue; /* keep looking for snap */
781 if (!clear_page_dirty_for_io(page
)) {
782 dout("%p !clear_page_dirty_for_io\n", page
);
788 if (locked_pages
== 0) {
789 /* prepare async write request */
790 offset
= page
->index
<< PAGE_CACHE_SHIFT
;
792 req
= ceph_osdc_new_request(&client
->osdc
,
797 CEPH_OSD_FLAG_WRITE
|
798 CEPH_OSD_FLAG_ONDISK
,
802 &inode
->i_mtime
, true, 1);
803 max_pages
= req
->r_num_pages
;
805 alloc_page_vec(client
, req
);
806 req
->r_callback
= writepages_finish
;
807 req
->r_inode
= inode
;
811 /* note position of first page in pvec */
814 dout("%p will write page %p idx %lu\n",
815 inode
, page
, page
->index
);
817 writeback_stat
= atomic_long_inc_return(&client
->writeback_count
);
818 if (writeback_stat
> CONGESTION_ON_THRESH(client
->mount_args
->congestion_kb
)) {
819 set_bdi_congested(&client
->backing_dev_info
, BLK_RW_ASYNC
);
822 set_page_writeback(page
);
823 req
->r_pages
[locked_pages
] = page
;
825 next
= page
->index
+ 1;
828 /* did we get anything? */
830 goto release_pvec_pages
;
833 BUG_ON(!locked_pages
|| first
< 0);
835 if (pvec_pages
&& i
== pvec_pages
&&
836 locked_pages
< max_pages
) {
837 dout("reached end pvec, trying for more\n");
838 pagevec_reinit(&pvec
);
842 /* shift unused pages over in the pvec... we
843 * will need to release them below. */
844 for (j
= i
; j
< pvec_pages
; j
++) {
845 dout(" pvec leftover page %p\n",
847 pvec
.pages
[j
-i
+first
] = pvec
.pages
[j
];
852 /* submit the write */
853 offset
= req
->r_pages
[0]->index
<< PAGE_CACHE_SHIFT
;
854 len
= min((snap_size
? snap_size
: i_size_read(inode
)) - offset
,
855 (u64
)locked_pages
<< PAGE_CACHE_SHIFT
);
856 dout("writepages got %d pages at %llu~%llu\n",
857 locked_pages
, offset
, len
);
859 /* revise final length, page count */
860 req
->r_num_pages
= locked_pages
;
861 reqhead
= req
->r_request
->front
.iov_base
;
862 op
= (void *)(reqhead
+ 1);
863 op
->extent
.length
= cpu_to_le64(len
);
864 op
->payload_len
= cpu_to_le32(len
);
865 req
->r_request
->hdr
.data_len
= cpu_to_le32(len
);
867 ceph_osdc_start_request(&client
->osdc
, req
, true);
872 wbc
->nr_to_write
-= locked_pages
;
873 if (wbc
->nr_to_write
<= 0)
877 dout("pagevec_release on %d pages (%p)\n", (int)pvec
.nr
,
878 pvec
.nr
? pvec
.pages
[0] : NULL
);
879 pagevec_release(&pvec
);
881 if (locked_pages
&& !done
)
885 if (should_loop
&& !done
) {
886 /* more to do; loop back to beginning of file */
887 dout("writepages looping back to beginning of file\n");
893 if (wbc
->range_cyclic
|| (range_whole
&& wbc
->nr_to_write
> 0))
894 mapping
->writeback_index
= index
;
898 ceph_osdc_put_request(req
);
900 rc
= 0; /* vfs expects us to return 0 */
901 ceph_put_snap_context(snapc
);
902 dout("writepages done, rc = %d\n", rc
);
910 * See if a given @snapc is either writeable, or already written.
912 static int context_is_writeable_or_written(struct inode
*inode
,
913 struct ceph_snap_context
*snapc
)
915 struct ceph_snap_context
*oldest
= get_oldest_context(inode
, NULL
);
916 return !oldest
|| snapc
->seq
<= oldest
->seq
;
920 * We are only allowed to write into/dirty the page if the page is
921 * clean, or already dirty within the same snap context.
923 static int ceph_update_writeable_page(struct file
*file
,
924 loff_t pos
, unsigned len
,
927 struct inode
*inode
= file
->f_dentry
->d_inode
;
928 struct ceph_inode_info
*ci
= ceph_inode(inode
);
929 struct ceph_mds_client
*mdsc
= &ceph_inode_to_client(inode
)->mdsc
;
930 loff_t page_off
= pos
& PAGE_CACHE_MASK
;
931 int pos_in_page
= pos
& ~PAGE_CACHE_MASK
;
932 int end_in_page
= pos_in_page
+ len
;
934 struct ceph_snap_context
*snapc
;
938 /* writepages currently holds page lock, but if we change that later, */
939 wait_on_page_writeback(page
);
941 /* check snap context */
942 BUG_ON(!ci
->i_snap_realm
);
943 down_read(&mdsc
->snap_rwsem
);
944 BUG_ON(!ci
->i_snap_realm
->cached_context
);
946 (void *)page
->private != ci
->i_snap_realm
->cached_context
) {
948 * this page is already dirty in another (older) snap
949 * context! is it writeable now?
951 snapc
= get_oldest_context(inode
, NULL
);
952 up_read(&mdsc
->snap_rwsem
);
954 if (snapc
!= (void *)page
->private) {
955 dout(" page %p snapc %p not current or oldest\n",
956 page
, (void *)page
->private);
958 * queue for writeback, and wait for snapc to
959 * be writeable or written
961 snapc
= ceph_get_snap_context((void *)page
->private);
963 ceph_queue_writeback(inode
);
964 wait_event_interruptible(ci
->i_cap_wq
,
965 context_is_writeable_or_written(inode
, snapc
));
966 ceph_put_snap_context(snapc
);
970 /* yay, writeable, do it now (without dropping page lock) */
971 dout(" page %p snapc %p not current, but oldest\n",
973 if (!clear_page_dirty_for_io(page
))
975 r
= writepage_nounlock(page
, NULL
);
981 if (PageUptodate(page
)) {
982 dout(" page %p already uptodate\n", page
);
987 if (pos_in_page
== 0 && len
== PAGE_CACHE_SIZE
)
990 /* past end of file? */
991 i_size
= inode
->i_size
; /* caller holds i_mutex */
993 if (i_size
+ len
> inode
->i_sb
->s_maxbytes
) {
994 /* file is too big */
999 if (page_off
>= i_size
||
1000 (pos_in_page
== 0 && (pos
+len
) >= i_size
&&
1001 end_in_page
- pos_in_page
!= PAGE_CACHE_SIZE
)) {
1002 dout(" zeroing %p 0 - %d and %d - %d\n",
1003 page
, pos_in_page
, end_in_page
, (int)PAGE_CACHE_SIZE
);
1004 zero_user_segments(page
,
1006 end_in_page
, PAGE_CACHE_SIZE
);
1010 /* we need to read it. */
1011 up_read(&mdsc
->snap_rwsem
);
1012 r
= readpage_nounlock(file
, page
);
1018 up_read(&mdsc
->snap_rwsem
);
1025 * We are only allowed to write into/dirty the page if the page is
1026 * clean, or already dirty within the same snap context.
1028 static int ceph_write_begin(struct file
*file
, struct address_space
*mapping
,
1029 loff_t pos
, unsigned len
, unsigned flags
,
1030 struct page
**pagep
, void **fsdata
)
1032 struct inode
*inode
= file
->f_dentry
->d_inode
;
1034 pgoff_t index
= pos
>> PAGE_CACHE_SHIFT
;
1039 page
= grab_cache_page_write_begin(mapping
, index
, 0);
1044 dout("write_begin file %p inode %p page %p %d~%d\n", file
,
1045 inode
, page
, (int)pos
, (int)len
);
1047 r
= ceph_update_writeable_page(file
, pos
, len
, page
);
1048 } while (r
== -EAGAIN
);
1054 * we don't do anything in here that simple_write_end doesn't do
1055 * except adjust dirty page accounting and drop read lock on
1058 static int ceph_write_end(struct file
*file
, struct address_space
*mapping
,
1059 loff_t pos
, unsigned len
, unsigned copied
,
1060 struct page
*page
, void *fsdata
)
1062 struct inode
*inode
= file
->f_dentry
->d_inode
;
1063 struct ceph_client
*client
= ceph_inode_to_client(inode
);
1064 struct ceph_mds_client
*mdsc
= &client
->mdsc
;
1065 unsigned from
= pos
& (PAGE_CACHE_SIZE
- 1);
1068 dout("write_end file %p inode %p page %p %d~%d (%d)\n", file
,
1069 inode
, page
, (int)pos
, (int)copied
, (int)len
);
1071 /* zero the stale part of the page if we did a short copy */
1073 zero_user_segment(page
, from
+copied
, len
);
1075 /* did file size increase? */
1076 /* (no need for i_size_read(); we caller holds i_mutex */
1077 if (pos
+copied
> inode
->i_size
)
1078 check_cap
= ceph_inode_set_size(inode
, pos
+copied
);
1080 if (!PageUptodate(page
))
1081 SetPageUptodate(page
);
1083 set_page_dirty(page
);
1086 up_read(&mdsc
->snap_rwsem
);
1087 page_cache_release(page
);
1090 ceph_check_caps(ceph_inode(inode
), CHECK_CAPS_AUTHONLY
, NULL
);
1096 * we set .direct_IO to indicate direct io is supported, but since we
1097 * intercept O_DIRECT reads and writes early, this function should
1100 static ssize_t
ceph_direct_io(int rw
, struct kiocb
*iocb
,
1101 const struct iovec
*iov
,
1102 loff_t pos
, unsigned long nr_segs
)
1108 const struct address_space_operations ceph_aops
= {
1109 .readpage
= ceph_readpage
,
1110 .readpages
= ceph_readpages
,
1111 .writepage
= ceph_writepage
,
1112 .writepages
= ceph_writepages_start
,
1113 .write_begin
= ceph_write_begin
,
1114 .write_end
= ceph_write_end
,
1115 .set_page_dirty
= ceph_set_page_dirty
,
1116 .invalidatepage
= ceph_invalidatepage
,
1117 .releasepage
= ceph_releasepage
,
1118 .direct_IO
= ceph_direct_io
,
1127 * Reuse write_begin here for simplicity.
1129 static int ceph_page_mkwrite(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
1131 struct inode
*inode
= vma
->vm_file
->f_dentry
->d_inode
;
1132 struct page
*page
= vmf
->page
;
1133 struct ceph_mds_client
*mdsc
= &ceph_inode_to_client(inode
)->mdsc
;
1134 loff_t off
= page
->index
<< PAGE_CACHE_SHIFT
;
1138 size
= i_size_read(inode
);
1139 if (off
+ PAGE_CACHE_SIZE
<= size
)
1140 len
= PAGE_CACHE_SIZE
;
1142 len
= size
& ~PAGE_CACHE_MASK
;
1144 dout("page_mkwrite %p %llu~%llu page %p idx %lu\n", inode
,
1145 off
, len
, page
, page
->index
);
1149 ret
= VM_FAULT_NOPAGE
;
1151 (page
->mapping
!= inode
->i_mapping
))
1154 ret
= ceph_update_writeable_page(vma
->vm_file
, off
, len
, page
);
1156 /* success. we'll keep the page locked. */
1157 set_page_dirty(page
);
1158 up_read(&mdsc
->snap_rwsem
);
1159 ret
= VM_FAULT_LOCKED
;
1164 ret
= VM_FAULT_SIGBUS
;
1167 dout("page_mkwrite %p %llu~%llu = %d\n", inode
, off
, len
, ret
);
1168 if (ret
!= VM_FAULT_LOCKED
)
1173 static struct vm_operations_struct ceph_vmops
= {
1174 .fault
= filemap_fault
,
1175 .page_mkwrite
= ceph_page_mkwrite
,
1178 int ceph_mmap(struct file
*file
, struct vm_area_struct
*vma
)
1180 struct address_space
*mapping
= file
->f_mapping
;
1182 if (!mapping
->a_ops
->readpage
)
1184 file_accessed(file
);
1185 vma
->vm_ops
= &ceph_vmops
;
1186 vma
->vm_flags
|= VM_CAN_NONLINEAR
;