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/slab.h>
9 #include <linux/pagevec.h>
10 #include <linux/task_io_accounting_ops.h>
13 #include "osd_client.h"
16 * Ceph address space ops.
18 * There are a few funny things going on here.
20 * The page->private field is used to reference a struct
21 * ceph_snap_context for _every_ dirty page. This indicates which
22 * snapshot the page was logically dirtied in, and thus which snap
23 * context needs to be associated with the osd write during writeback.
25 * Similarly, struct ceph_inode_info maintains a set of counters to
26 * count dirty pages on the inode. In the absense of snapshots,
27 * i_wrbuffer_ref == i_wrbuffer_ref_head == the dirty page count.
29 * When a snapshot is taken (that is, when the client receives
30 * notification that a snapshot was taken), each inode with caps and
31 * with dirty pages (dirty pages implies there is a cap) gets a new
32 * ceph_cap_snap in the i_cap_snaps list (which is sorted in ascending
33 * order, new snaps go to the tail). The i_wrbuffer_ref_head count is
34 * moved to capsnap->dirty. (Unless a sync write is currently in
35 * progress. In that case, the capsnap is said to be "pending", new
36 * writes cannot start, and the capsnap isn't "finalized" until the
37 * write completes (or fails) and a final size/mtime for the inode for
38 * that snap can be settled upon.) i_wrbuffer_ref_head is reset to 0.
40 * On writeback, we must submit writes to the osd IN SNAP ORDER. So,
41 * we look for the first capsnap in i_cap_snaps and write out pages in
42 * that snap context _only_. Then we move on to the next capsnap,
43 * eventually reaching the "live" or "head" context (i.e., pages that
44 * are not yet snapped) and are writing the most recently dirtied
47 * Invalidate and so forth must take care to ensure the dirty page
48 * accounting is preserved.
51 #define CONGESTION_ON_THRESH(congestion_kb) (congestion_kb >> (PAGE_SHIFT-10))
52 #define CONGESTION_OFF_THRESH(congestion_kb) \
53 (CONGESTION_ON_THRESH(congestion_kb) - \
54 (CONGESTION_ON_THRESH(congestion_kb) >> 2))
59 * Dirty a page. Optimistically adjust accounting, on the assumption
60 * that we won't race with invalidate. If we do, readjust.
62 static int ceph_set_page_dirty(struct page
*page
)
64 struct address_space
*mapping
= page
->mapping
;
66 struct ceph_inode_info
*ci
;
68 struct ceph_snap_context
*snapc
;
70 if (unlikely(!mapping
))
71 return !TestSetPageDirty(page
);
73 if (TestSetPageDirty(page
)) {
74 dout("%p set_page_dirty %p idx %lu -- already dirty\n",
75 mapping
->host
, page
, page
->index
);
79 inode
= mapping
->host
;
80 ci
= ceph_inode(inode
);
83 * Note that we're grabbing a snapc ref here without holding
86 snapc
= ceph_get_snap_context(ci
->i_snap_realm
->cached_context
);
89 spin_lock(&inode
->i_lock
);
90 if (ci
->i_wrbuffer_ref_head
== 0)
91 ci
->i_head_snapc
= ceph_get_snap_context(snapc
);
92 ++ci
->i_wrbuffer_ref_head
;
93 if (ci
->i_wrbuffer_ref
== 0)
96 dout("%p set_page_dirty %p idx %lu head %d/%d -> %d/%d "
97 "snapc %p seq %lld (%d snaps)\n",
98 mapping
->host
, page
, page
->index
,
99 ci
->i_wrbuffer_ref
-1, ci
->i_wrbuffer_ref_head
-1,
100 ci
->i_wrbuffer_ref
, ci
->i_wrbuffer_ref_head
,
101 snapc
, snapc
->seq
, snapc
->num_snaps
);
102 spin_unlock(&inode
->i_lock
);
104 /* now adjust page */
105 spin_lock_irq(&mapping
->tree_lock
);
106 if (page
->mapping
) { /* Race with truncate? */
107 WARN_ON_ONCE(!PageUptodate(page
));
109 if (mapping_cap_account_dirty(mapping
)) {
110 __inc_zone_page_state(page
, NR_FILE_DIRTY
);
111 __inc_bdi_stat(mapping
->backing_dev_info
,
113 task_io_account_write(PAGE_CACHE_SIZE
);
115 radix_tree_tag_set(&mapping
->page_tree
,
116 page_index(page
), PAGECACHE_TAG_DIRTY
);
119 * Reference snap context in page->private. Also set
120 * PagePrivate so that we get invalidatepage callback.
122 page
->private = (unsigned long)snapc
;
123 SetPagePrivate(page
);
125 dout("ANON set_page_dirty %p (raced truncate?)\n", page
);
129 spin_unlock_irq(&mapping
->tree_lock
);
132 /* whoops, we failed to dirty the page */
133 ceph_put_wrbuffer_cap_refs(ci
, 1, snapc
);
135 __mark_inode_dirty(mapping
->host
, I_DIRTY_PAGES
);
137 BUG_ON(!PageDirty(page
));
142 * If we are truncating the full page (i.e. offset == 0), adjust the
143 * dirty page counters appropriately. Only called if there is private
146 static void ceph_invalidatepage(struct page
*page
, unsigned long offset
)
149 struct ceph_inode_info
*ci
;
150 struct ceph_snap_context
*snapc
= (void *)page
->private;
152 BUG_ON(!PageLocked(page
));
153 BUG_ON(!page
->private);
154 BUG_ON(!PagePrivate(page
));
155 BUG_ON(!page
->mapping
);
157 inode
= page
->mapping
->host
;
160 * We can get non-dirty pages here due to races between
161 * set_page_dirty and truncate_complete_page; just spit out a
162 * warning, in case we end up with accounting problems later.
164 if (!PageDirty(page
))
165 pr_err("%p invalidatepage %p page not dirty\n", inode
, page
);
168 ClearPageChecked(page
);
170 ci
= ceph_inode(inode
);
172 dout("%p invalidatepage %p idx %lu full dirty page %lu\n",
173 inode
, page
, page
->index
, offset
);
174 ceph_put_wrbuffer_cap_refs(ci
, 1, snapc
);
175 ceph_put_snap_context(snapc
);
177 ClearPagePrivate(page
);
179 dout("%p invalidatepage %p idx %lu partial dirty page\n",
180 inode
, page
, page
->index
);
184 /* just a sanity check */
185 static int ceph_releasepage(struct page
*page
, gfp_t g
)
187 struct inode
*inode
= page
->mapping
? page
->mapping
->host
: NULL
;
188 dout("%p releasepage %p idx %lu\n", inode
, page
, page
->index
);
189 WARN_ON(PageDirty(page
));
190 WARN_ON(page
->private);
191 WARN_ON(PagePrivate(page
));
196 * read a single page, without unlocking it.
198 static int readpage_nounlock(struct file
*filp
, struct page
*page
)
200 struct inode
*inode
= filp
->f_dentry
->d_inode
;
201 struct ceph_inode_info
*ci
= ceph_inode(inode
);
202 struct ceph_osd_client
*osdc
= &ceph_inode_to_client(inode
)->osdc
;
204 u64 len
= PAGE_CACHE_SIZE
;
206 dout("readpage inode %p file %p page %p index %lu\n",
207 inode
, filp
, page
, page
->index
);
208 err
= ceph_osdc_readpages(osdc
, ceph_vino(inode
), &ci
->i_layout
,
209 page
->index
<< PAGE_CACHE_SHIFT
, &len
,
210 ci
->i_truncate_seq
, ci
->i_truncate_size
,
217 } else if (err
< PAGE_CACHE_SIZE
) {
218 /* zero fill remainder of page */
219 zero_user_segment(page
, err
, PAGE_CACHE_SIZE
);
221 SetPageUptodate(page
);
224 return err
< 0 ? err
: 0;
227 static int ceph_readpage(struct file
*filp
, struct page
*page
)
229 int r
= readpage_nounlock(filp
, page
);
235 * Build a vector of contiguous pages from the provided page list.
237 static struct page
**page_vector_from_list(struct list_head
*page_list
,
242 int next_index
, contig_pages
= 0;
244 /* build page vector */
245 pages
= kmalloc(sizeof(*pages
) * *nr_pages
, GFP_NOFS
);
247 return ERR_PTR(-ENOMEM
);
249 BUG_ON(list_empty(page_list
));
250 next_index
= list_entry(page_list
->prev
, struct page
, lru
)->index
;
251 list_for_each_entry_reverse(page
, page_list
, lru
) {
252 if (page
->index
== next_index
) {
253 dout("readpages page %d %p\n", contig_pages
, page
);
254 pages
[contig_pages
] = page
;
261 *nr_pages
= contig_pages
;
266 * Read multiple pages. Leave pages we don't read + unlock in page_list;
267 * the caller (VM) cleans them up.
269 static int ceph_readpages(struct file
*file
, struct address_space
*mapping
,
270 struct list_head
*page_list
, unsigned nr_pages
)
272 struct inode
*inode
= file
->f_dentry
->d_inode
;
273 struct ceph_inode_info
*ci
= ceph_inode(inode
);
274 struct ceph_osd_client
*osdc
= &ceph_inode_to_client(inode
)->osdc
;
281 dout("readpages %p file %p nr_pages %d\n",
282 inode
, file
, nr_pages
);
284 pages
= page_vector_from_list(page_list
, &nr_pages
);
286 return PTR_ERR(pages
);
288 /* guess read extent */
289 offset
= pages
[0]->index
<< PAGE_CACHE_SHIFT
;
290 len
= nr_pages
<< PAGE_CACHE_SHIFT
;
291 rc
= ceph_osdc_readpages(osdc
, ceph_vino(inode
), &ci
->i_layout
,
293 ci
->i_truncate_seq
, ci
->i_truncate_size
,
300 /* set uptodate and add to lru in pagevec-sized chunks */
301 pagevec_init(&pvec
, 0);
302 for (; !list_empty(page_list
) && len
> 0;
303 rc
-= PAGE_CACHE_SIZE
, len
-= PAGE_CACHE_SIZE
) {
305 list_entry(page_list
->prev
, struct page
, lru
);
307 list_del(&page
->lru
);
309 if (rc
< (int)PAGE_CACHE_SIZE
) {
310 /* zero (remainder of) page */
311 int s
= rc
< 0 ? 0 : rc
;
312 zero_user_segment(page
, s
, PAGE_CACHE_SIZE
);
315 if (add_to_page_cache(page
, mapping
, page
->index
, GFP_NOFS
)) {
316 page_cache_release(page
);
317 dout("readpages %p add_to_page_cache failed %p\n",
321 dout("readpages %p adding %p idx %lu\n", inode
, page
,
323 flush_dcache_page(page
);
324 SetPageUptodate(page
);
326 if (pagevec_add(&pvec
, page
) == 0)
327 pagevec_lru_add_file(&pvec
); /* add to lru */
329 pagevec_lru_add_file(&pvec
);
338 * Get ref for the oldest snapc for an inode with dirty data... that is, the
339 * only snap context we are allowed to write back.
341 * Caller holds i_lock.
343 static struct ceph_snap_context
*__get_oldest_context(struct inode
*inode
,
346 struct ceph_inode_info
*ci
= ceph_inode(inode
);
347 struct ceph_snap_context
*snapc
= NULL
;
348 struct ceph_cap_snap
*capsnap
= NULL
;
350 list_for_each_entry(capsnap
, &ci
->i_cap_snaps
, ci_item
) {
351 dout(" cap_snap %p snapc %p has %d dirty pages\n", capsnap
,
352 capsnap
->context
, capsnap
->dirty_pages
);
353 if (capsnap
->dirty_pages
) {
354 snapc
= ceph_get_snap_context(capsnap
->context
);
356 *snap_size
= capsnap
->size
;
360 if (!snapc
&& ci
->i_snap_realm
) {
361 snapc
= ceph_get_snap_context(ci
->i_snap_realm
->cached_context
);
362 dout(" head snapc %p has %d dirty pages\n",
363 snapc
, ci
->i_wrbuffer_ref_head
);
368 static struct ceph_snap_context
*get_oldest_context(struct inode
*inode
,
371 struct ceph_snap_context
*snapc
= NULL
;
373 spin_lock(&inode
->i_lock
);
374 snapc
= __get_oldest_context(inode
, snap_size
);
375 spin_unlock(&inode
->i_lock
);
380 * Write a single page, but leave the page locked.
382 * If we get a write error, set the page error bit, but still adjust the
383 * dirty page accounting (i.e., page is no longer dirty).
385 static int writepage_nounlock(struct page
*page
, struct writeback_control
*wbc
)
388 struct ceph_inode_info
*ci
;
389 struct ceph_client
*client
;
390 struct ceph_osd_client
*osdc
;
391 loff_t page_off
= page
->index
<< PAGE_CACHE_SHIFT
;
392 int len
= PAGE_CACHE_SIZE
;
395 struct ceph_snap_context
*snapc
;
399 dout("writepage %p idx %lu\n", page
, page
->index
);
401 if (!page
->mapping
|| !page
->mapping
->host
) {
402 dout("writepage %p - no mapping\n", page
);
405 inode
= page
->mapping
->host
;
406 ci
= ceph_inode(inode
);
407 client
= ceph_inode_to_client(inode
);
408 osdc
= &client
->osdc
;
410 /* verify this is a writeable snap context */
411 snapc
= (void *)page
->private;
413 dout("writepage %p page %p not dirty?\n", inode
, page
);
416 if (snapc
!= get_oldest_context(inode
, &snap_size
)) {
417 dout("writepage %p page %p snapc %p not writeable - noop\n",
418 inode
, page
, (void *)page
->private);
419 /* we should only noop if called by kswapd */
420 WARN_ON((current
->flags
& PF_MEMALLOC
) == 0);
424 /* is this a partial page at end of file? */
428 i_size
= i_size_read(inode
);
429 if (i_size
< page_off
+ len
)
430 len
= i_size
- page_off
;
432 dout("writepage %p page %p index %lu on %llu~%u\n",
433 inode
, page
, page
->index
, page_off
, len
);
435 writeback_stat
= atomic_long_inc_return(&client
->writeback_count
);
437 CONGESTION_ON_THRESH(client
->mount_args
->congestion_kb
))
438 set_bdi_congested(&client
->backing_dev_info
, BLK_RW_ASYNC
);
440 set_page_writeback(page
);
441 err
= ceph_osdc_writepages(osdc
, ceph_vino(inode
),
442 &ci
->i_layout
, snapc
,
444 ci
->i_truncate_seq
, ci
->i_truncate_size
,
446 &page
, 1, 0, 0, true);
448 dout("writepage setting page/mapping error %d %p\n", err
, page
);
450 mapping_set_error(&inode
->i_data
, err
);
452 wbc
->pages_skipped
++;
454 dout("writepage cleaned page %p\n", page
);
455 err
= 0; /* vfs expects us to return 0 */
458 ClearPagePrivate(page
);
459 end_page_writeback(page
);
460 ceph_put_wrbuffer_cap_refs(ci
, 1, snapc
);
461 ceph_put_snap_context(snapc
);
466 static int ceph_writepage(struct page
*page
, struct writeback_control
*wbc
)
469 struct inode
*inode
= page
->mapping
->host
;
472 err
= writepage_nounlock(page
, wbc
);
480 * lame release_pages helper. release_pages() isn't exported to
483 static void ceph_release_pages(struct page
**pages
, int num
)
488 pagevec_init(&pvec
, 0);
489 for (i
= 0; i
< num
; i
++) {
490 if (pagevec_add(&pvec
, pages
[i
]) == 0)
491 pagevec_release(&pvec
);
493 pagevec_release(&pvec
);
498 * async writeback completion handler.
500 * If we get an error, set the mapping error bit, but not the individual
503 static void writepages_finish(struct ceph_osd_request
*req
,
504 struct ceph_msg
*msg
)
506 struct inode
*inode
= req
->r_inode
;
507 struct ceph_osd_reply_head
*replyhead
;
508 struct ceph_osd_op
*op
;
509 struct ceph_inode_info
*ci
= ceph_inode(inode
);
513 struct ceph_snap_context
*snapc
= req
->r_snapc
;
514 struct address_space
*mapping
= inode
->i_mapping
;
515 struct writeback_control
*wbc
= req
->r_wbc
;
518 struct ceph_client
*client
= ceph_inode_to_client(inode
);
520 unsigned issued
= __ceph_caps_issued(ci
, NULL
);
523 replyhead
= msg
->front
.iov_base
;
524 WARN_ON(le32_to_cpu(replyhead
->num_ops
) == 0);
525 op
= (void *)(replyhead
+ 1);
526 rc
= le32_to_cpu(replyhead
->result
);
527 bytes
= le64_to_cpu(op
->extent
.length
);
531 * Assume we wrote the pages we originally sent. The
532 * osd might reply with fewer pages if our writeback
533 * raced with a truncation and was adjusted at the osd,
534 * so don't believe the reply.
536 wrote
= req
->r_num_pages
;
539 mapping_set_error(mapping
, rc
);
541 dout("writepages_finish %p rc %d bytes %llu wrote %d (pages)\n",
542 inode
, rc
, bytes
, wrote
);
544 /* clean all pages */
545 for (i
= 0; i
< req
->r_num_pages
; i
++) {
546 page
= req
->r_pages
[i
];
548 WARN_ON(!PageUptodate(page
));
551 atomic_long_dec_return(&client
->writeback_count
);
553 CONGESTION_OFF_THRESH(client
->mount_args
->congestion_kb
))
554 clear_bdi_congested(&client
->backing_dev_info
,
558 dout("inode %p skipping page %p\n", inode
, page
);
559 wbc
->pages_skipped
++;
562 ClearPagePrivate(page
);
563 ceph_put_snap_context(snapc
);
564 dout("unlocking %d %p\n", i
, page
);
565 end_page_writeback(page
);
568 * We lost the cache cap, need to truncate the page before
569 * it is unlocked, otherwise we'd truncate it later in the
570 * page truncation thread, possibly losing some data that
573 if ((issued
& CEPH_CAP_FILE_CACHE
) == 0)
574 generic_error_remove_page(inode
->i_mapping
, page
);
578 dout("%p wrote+cleaned %d pages\n", inode
, wrote
);
579 ceph_put_wrbuffer_cap_refs(ci
, req
->r_num_pages
, snapc
);
581 ceph_release_pages(req
->r_pages
, req
->r_num_pages
);
582 if (req
->r_pages_from_pool
)
583 mempool_free(req
->r_pages
,
584 ceph_client(inode
->i_sb
)->wb_pagevec_pool
);
587 ceph_osdc_put_request(req
);
591 * allocate a page vec, either directly, or if necessary, via a the
592 * mempool. we avoid the mempool if we can because req->r_num_pages
593 * may be less than the maximum write size.
595 static void alloc_page_vec(struct ceph_client
*client
,
596 struct ceph_osd_request
*req
)
598 req
->r_pages
= kmalloc(sizeof(struct page
*) * req
->r_num_pages
,
601 req
->r_pages
= mempool_alloc(client
->wb_pagevec_pool
, GFP_NOFS
);
602 req
->r_pages_from_pool
= 1;
603 WARN_ON(!req
->r_pages
);
608 * initiate async writeback
610 static int ceph_writepages_start(struct address_space
*mapping
,
611 struct writeback_control
*wbc
)
613 struct inode
*inode
= mapping
->host
;
614 struct backing_dev_info
*bdi
= mapping
->backing_dev_info
;
615 struct ceph_inode_info
*ci
= ceph_inode(inode
);
616 struct ceph_client
*client
;
617 pgoff_t index
, start
, end
;
620 pgoff_t max_pages
= 0, max_pages_ever
= 0;
621 struct ceph_snap_context
*snapc
= NULL
, *last_snapc
= NULL
;
625 unsigned wsize
= 1 << inode
->i_blkbits
;
626 struct ceph_osd_request
*req
= NULL
;
631 * Include a 'sync' in the OSD request if this is a data
632 * integrity write (e.g., O_SYNC write or fsync()), or if our
633 * cap is being revoked.
635 do_sync
= wbc
->sync_mode
== WB_SYNC_ALL
;
636 if (ceph_caps_revoking(ci
, CEPH_CAP_FILE_BUFFER
))
638 dout("writepages_start %p dosync=%d (mode=%s)\n",
640 wbc
->sync_mode
== WB_SYNC_NONE
? "NONE" :
641 (wbc
->sync_mode
== WB_SYNC_ALL
? "ALL" : "HOLD"));
643 client
= ceph_inode_to_client(inode
);
644 if (client
->mount_state
== CEPH_MOUNT_SHUTDOWN
) {
645 pr_warning("writepage_start %p on forced umount\n", inode
);
646 return -EIO
; /* we're in a forced umount, don't write! */
648 if (client
->mount_args
->wsize
&& client
->mount_args
->wsize
< wsize
)
649 wsize
= client
->mount_args
->wsize
;
650 if (wsize
< PAGE_CACHE_SIZE
)
651 wsize
= PAGE_CACHE_SIZE
;
652 max_pages_ever
= wsize
>> PAGE_CACHE_SHIFT
;
654 pagevec_init(&pvec
, 0);
657 if (wbc
->nonblocking
&& bdi_write_congested(bdi
)) {
658 dout(" writepages congested\n");
659 wbc
->encountered_congestion
= 1;
663 /* where to start/end? */
664 if (wbc
->range_cyclic
) {
665 start
= mapping
->writeback_index
; /* Start from prev offset */
667 dout(" cyclic, start at %lu\n", start
);
669 start
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
670 end
= wbc
->range_end
>> PAGE_CACHE_SHIFT
;
671 if (wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
)
674 dout(" not cyclic, %lu to %lu\n", start
, end
);
679 /* find oldest snap context with dirty data */
680 ceph_put_snap_context(snapc
);
681 snapc
= get_oldest_context(inode
, &snap_size
);
683 /* hmm, why does writepages get called when there
685 dout(" no snap context with dirty data?\n");
688 dout(" oldest snapc is %p seq %lld (%d snaps)\n",
689 snapc
, snapc
->seq
, snapc
->num_snaps
);
690 if (last_snapc
&& snapc
!= last_snapc
) {
691 /* if we switched to a newer snapc, restart our scan at the
692 * start of the original file range. */
693 dout(" snapc differs from last pass, restarting at %lu\n",
699 while (!done
&& index
<= end
) {
703 int pvec_pages
, locked_pages
;
707 struct ceph_osd_request_head
*reqhead
;
708 struct ceph_osd_op
*op
;
713 max_pages
= max_pages_ever
;
717 want
= min(end
- index
,
718 min((pgoff_t
)PAGEVEC_SIZE
,
719 max_pages
- (pgoff_t
)locked_pages
) - 1)
721 pvec_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
,
724 dout("pagevec_lookup_tag got %d\n", pvec_pages
);
725 if (!pvec_pages
&& !locked_pages
)
727 for (i
= 0; i
< pvec_pages
&& locked_pages
< max_pages
; i
++) {
728 page
= pvec
.pages
[i
];
729 dout("? %p idx %lu\n", page
, page
->index
);
730 if (locked_pages
== 0)
731 lock_page(page
); /* first page */
732 else if (!trylock_page(page
))
735 /* only dirty pages, or our accounting breaks */
736 if (unlikely(!PageDirty(page
)) ||
737 unlikely(page
->mapping
!= mapping
)) {
738 dout("!dirty or !mapping %p\n", page
);
742 if (!wbc
->range_cyclic
&& page
->index
> end
) {
743 dout("end of range %p\n", page
);
748 if (next
&& (page
->index
!= next
)) {
749 dout("not consecutive %p\n", page
);
753 if (wbc
->sync_mode
!= WB_SYNC_NONE
) {
754 dout("waiting on writeback %p\n", page
);
755 wait_on_page_writeback(page
);
757 if ((snap_size
&& page_offset(page
) > snap_size
) ||
759 page_offset(page
) > i_size_read(inode
))) {
760 dout("%p page eof %llu\n", page
, snap_size
?
761 snap_size
: i_size_read(inode
));
766 if (PageWriteback(page
)) {
767 dout("%p under writeback\n", page
);
772 /* only if matching snap context */
773 if (snapc
!= (void *)page
->private) {
774 dout("page snapc %p != oldest %p\n",
775 (void *)page
->private, snapc
);
778 continue; /* keep looking for snap */
782 if (!clear_page_dirty_for_io(page
)) {
783 dout("%p !clear_page_dirty_for_io\n", page
);
789 if (locked_pages
== 0) {
790 /* prepare async write request */
791 offset
= page
->index
<< PAGE_CACHE_SHIFT
;
793 req
= ceph_osdc_new_request(&client
->osdc
,
798 CEPH_OSD_FLAG_WRITE
|
799 CEPH_OSD_FLAG_ONDISK
,
803 &inode
->i_mtime
, true, 1);
804 max_pages
= req
->r_num_pages
;
806 alloc_page_vec(client
, req
);
807 req
->r_callback
= writepages_finish
;
808 req
->r_inode
= inode
;
812 /* note position of first page in pvec */
815 dout("%p will write page %p idx %lu\n",
816 inode
, page
, page
->index
);
818 writeback_stat
= atomic_long_inc_return(&client
->writeback_count
);
819 if (writeback_stat
> CONGESTION_ON_THRESH(client
->mount_args
->congestion_kb
)) {
820 set_bdi_congested(&client
->backing_dev_info
, BLK_RW_ASYNC
);
823 set_page_writeback(page
);
824 req
->r_pages
[locked_pages
] = page
;
826 next
= page
->index
+ 1;
829 /* did we get anything? */
831 goto release_pvec_pages
;
834 BUG_ON(!locked_pages
|| first
< 0);
836 if (pvec_pages
&& i
== pvec_pages
&&
837 locked_pages
< max_pages
) {
838 dout("reached end pvec, trying for more\n");
839 pagevec_reinit(&pvec
);
843 /* shift unused pages over in the pvec... we
844 * will need to release them below. */
845 for (j
= i
; j
< pvec_pages
; j
++) {
846 dout(" pvec leftover page %p\n",
848 pvec
.pages
[j
-i
+first
] = pvec
.pages
[j
];
853 /* submit the write */
854 offset
= req
->r_pages
[0]->index
<< PAGE_CACHE_SHIFT
;
855 len
= min((snap_size
? snap_size
: i_size_read(inode
)) - offset
,
856 (u64
)locked_pages
<< PAGE_CACHE_SHIFT
);
857 dout("writepages got %d pages at %llu~%llu\n",
858 locked_pages
, offset
, len
);
860 /* revise final length, page count */
861 req
->r_num_pages
= locked_pages
;
862 reqhead
= req
->r_request
->front
.iov_base
;
863 op
= (void *)(reqhead
+ 1);
864 op
->extent
.length
= cpu_to_le64(len
);
865 op
->payload_len
= cpu_to_le32(len
);
866 req
->r_request
->hdr
.data_len
= cpu_to_le32(len
);
868 ceph_osdc_start_request(&client
->osdc
, req
, true);
873 wbc
->nr_to_write
-= locked_pages
;
874 if (wbc
->nr_to_write
<= 0)
878 dout("pagevec_release on %d pages (%p)\n", (int)pvec
.nr
,
879 pvec
.nr
? pvec
.pages
[0] : NULL
);
880 pagevec_release(&pvec
);
882 if (locked_pages
&& !done
)
886 if (should_loop
&& !done
) {
887 /* more to do; loop back to beginning of file */
888 dout("writepages looping back to beginning of file\n");
894 if (wbc
->range_cyclic
|| (range_whole
&& wbc
->nr_to_write
> 0))
895 mapping
->writeback_index
= index
;
899 ceph_osdc_put_request(req
);
901 rc
= 0; /* vfs expects us to return 0 */
902 ceph_put_snap_context(snapc
);
903 dout("writepages done, rc = %d\n", rc
);
911 * See if a given @snapc is either writeable, or already written.
913 static int context_is_writeable_or_written(struct inode
*inode
,
914 struct ceph_snap_context
*snapc
)
916 struct ceph_snap_context
*oldest
= get_oldest_context(inode
, NULL
);
917 return !oldest
|| snapc
->seq
<= oldest
->seq
;
921 * We are only allowed to write into/dirty the page if the page is
922 * clean, or already dirty within the same snap context.
924 * called with page locked.
925 * return success with page locked,
926 * or any failure (incl -EAGAIN) with page unlocked.
928 static int ceph_update_writeable_page(struct file
*file
,
929 loff_t pos
, unsigned len
,
932 struct inode
*inode
= file
->f_dentry
->d_inode
;
933 struct ceph_inode_info
*ci
= ceph_inode(inode
);
934 struct ceph_mds_client
*mdsc
= &ceph_inode_to_client(inode
)->mdsc
;
935 loff_t page_off
= pos
& PAGE_CACHE_MASK
;
936 int pos_in_page
= pos
& ~PAGE_CACHE_MASK
;
937 int end_in_page
= pos_in_page
+ len
;
939 struct ceph_snap_context
*snapc
;
943 /* writepages currently holds page lock, but if we change that later, */
944 wait_on_page_writeback(page
);
946 /* check snap context */
947 BUG_ON(!ci
->i_snap_realm
);
948 down_read(&mdsc
->snap_rwsem
);
949 BUG_ON(!ci
->i_snap_realm
->cached_context
);
951 (void *)page
->private != ci
->i_snap_realm
->cached_context
) {
953 * this page is already dirty in another (older) snap
954 * context! is it writeable now?
956 snapc
= get_oldest_context(inode
, NULL
);
957 up_read(&mdsc
->snap_rwsem
);
959 if (snapc
!= (void *)page
->private) {
960 dout(" page %p snapc %p not current or oldest\n",
961 page
, (void *)page
->private);
963 * queue for writeback, and wait for snapc to
964 * be writeable or written
966 snapc
= ceph_get_snap_context((void *)page
->private);
968 ceph_queue_writeback(inode
);
969 r
= wait_event_interruptible(ci
->i_cap_wq
,
970 context_is_writeable_or_written(inode
, snapc
));
971 ceph_put_snap_context(snapc
);
972 if (r
== -ERESTARTSYS
)
977 /* yay, writeable, do it now (without dropping page lock) */
978 dout(" page %p snapc %p not current, but oldest\n",
980 if (!clear_page_dirty_for_io(page
))
982 r
= writepage_nounlock(page
, NULL
);
988 if (PageUptodate(page
)) {
989 dout(" page %p already uptodate\n", page
);
994 if (pos_in_page
== 0 && len
== PAGE_CACHE_SIZE
)
997 /* past end of file? */
998 i_size
= inode
->i_size
; /* caller holds i_mutex */
1000 if (i_size
+ len
> inode
->i_sb
->s_maxbytes
) {
1001 /* file is too big */
1006 if (page_off
>= i_size
||
1007 (pos_in_page
== 0 && (pos
+len
) >= i_size
&&
1008 end_in_page
- pos_in_page
!= PAGE_CACHE_SIZE
)) {
1009 dout(" zeroing %p 0 - %d and %d - %d\n",
1010 page
, pos_in_page
, end_in_page
, (int)PAGE_CACHE_SIZE
);
1011 zero_user_segments(page
,
1013 end_in_page
, PAGE_CACHE_SIZE
);
1017 /* we need to read it. */
1018 up_read(&mdsc
->snap_rwsem
);
1019 r
= readpage_nounlock(file
, page
);
1025 up_read(&mdsc
->snap_rwsem
);
1032 * We are only allowed to write into/dirty the page if the page is
1033 * clean, or already dirty within the same snap context.
1035 static int ceph_write_begin(struct file
*file
, struct address_space
*mapping
,
1036 loff_t pos
, unsigned len
, unsigned flags
,
1037 struct page
**pagep
, void **fsdata
)
1039 struct inode
*inode
= file
->f_dentry
->d_inode
;
1041 pgoff_t index
= pos
>> PAGE_CACHE_SHIFT
;
1046 page
= grab_cache_page_write_begin(mapping
, index
, 0);
1051 dout("write_begin file %p inode %p page %p %d~%d\n", file
,
1052 inode
, page
, (int)pos
, (int)len
);
1054 r
= ceph_update_writeable_page(file
, pos
, len
, page
);
1055 } while (r
== -EAGAIN
);
1061 * we don't do anything in here that simple_write_end doesn't do
1062 * except adjust dirty page accounting and drop read lock on
1065 static int ceph_write_end(struct file
*file
, struct address_space
*mapping
,
1066 loff_t pos
, unsigned len
, unsigned copied
,
1067 struct page
*page
, void *fsdata
)
1069 struct inode
*inode
= file
->f_dentry
->d_inode
;
1070 struct ceph_client
*client
= ceph_inode_to_client(inode
);
1071 struct ceph_mds_client
*mdsc
= &client
->mdsc
;
1072 unsigned from
= pos
& (PAGE_CACHE_SIZE
- 1);
1075 dout("write_end file %p inode %p page %p %d~%d (%d)\n", file
,
1076 inode
, page
, (int)pos
, (int)copied
, (int)len
);
1078 /* zero the stale part of the page if we did a short copy */
1080 zero_user_segment(page
, from
+copied
, len
);
1082 /* did file size increase? */
1083 /* (no need for i_size_read(); we caller holds i_mutex */
1084 if (pos
+copied
> inode
->i_size
)
1085 check_cap
= ceph_inode_set_size(inode
, pos
+copied
);
1087 if (!PageUptodate(page
))
1088 SetPageUptodate(page
);
1090 set_page_dirty(page
);
1093 up_read(&mdsc
->snap_rwsem
);
1094 page_cache_release(page
);
1097 ceph_check_caps(ceph_inode(inode
), CHECK_CAPS_AUTHONLY
, NULL
);
1103 * we set .direct_IO to indicate direct io is supported, but since we
1104 * intercept O_DIRECT reads and writes early, this function should
1107 static ssize_t
ceph_direct_io(int rw
, struct kiocb
*iocb
,
1108 const struct iovec
*iov
,
1109 loff_t pos
, unsigned long nr_segs
)
1115 const struct address_space_operations ceph_aops
= {
1116 .readpage
= ceph_readpage
,
1117 .readpages
= ceph_readpages
,
1118 .writepage
= ceph_writepage
,
1119 .writepages
= ceph_writepages_start
,
1120 .write_begin
= ceph_write_begin
,
1121 .write_end
= ceph_write_end
,
1122 .set_page_dirty
= ceph_set_page_dirty
,
1123 .invalidatepage
= ceph_invalidatepage
,
1124 .releasepage
= ceph_releasepage
,
1125 .direct_IO
= ceph_direct_io
,
1134 * Reuse write_begin here for simplicity.
1136 static int ceph_page_mkwrite(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
1138 struct inode
*inode
= vma
->vm_file
->f_dentry
->d_inode
;
1139 struct page
*page
= vmf
->page
;
1140 struct ceph_mds_client
*mdsc
= &ceph_inode_to_client(inode
)->mdsc
;
1141 loff_t off
= page
->index
<< PAGE_CACHE_SHIFT
;
1145 size
= i_size_read(inode
);
1146 if (off
+ PAGE_CACHE_SIZE
<= size
)
1147 len
= PAGE_CACHE_SIZE
;
1149 len
= size
& ~PAGE_CACHE_MASK
;
1151 dout("page_mkwrite %p %llu~%llu page %p idx %lu\n", inode
,
1152 off
, len
, page
, page
->index
);
1156 ret
= VM_FAULT_NOPAGE
;
1158 (page
->mapping
!= inode
->i_mapping
))
1161 ret
= ceph_update_writeable_page(vma
->vm_file
, off
, len
, page
);
1163 /* success. we'll keep the page locked. */
1164 set_page_dirty(page
);
1165 up_read(&mdsc
->snap_rwsem
);
1166 ret
= VM_FAULT_LOCKED
;
1171 ret
= VM_FAULT_SIGBUS
;
1174 dout("page_mkwrite %p %llu~%llu = %d\n", inode
, off
, len
, ret
);
1175 if (ret
!= VM_FAULT_LOCKED
)
1180 static struct vm_operations_struct ceph_vmops
= {
1181 .fault
= filemap_fault
,
1182 .page_mkwrite
= ceph_page_mkwrite
,
1185 int ceph_mmap(struct file
*file
, struct vm_area_struct
*vma
)
1187 struct address_space
*mapping
= file
->f_mapping
;
1189 if (!mapping
->a_ops
->readpage
)
1191 file_accessed(file
);
1192 vma
->vm_ops
= &ceph_vmops
;
1193 vma
->vm_flags
|= VM_CAN_NONLINEAR
;