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
)
147 struct inode
*inode
= page
->mapping
->host
;
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
);
157 * We can get non-dirty pages here due to races between
158 * set_page_dirty and truncate_complete_page; just spit out a
159 * warning, in case we end up with accounting problems later.
161 if (!PageDirty(page
))
162 pr_err("%p invalidatepage %p page not dirty\n", inode
, page
);
165 ClearPageChecked(page
);
167 ci
= ceph_inode(inode
);
169 dout("%p invalidatepage %p idx %lu full dirty page %lu\n",
170 inode
, page
, page
->index
, offset
);
171 ceph_put_wrbuffer_cap_refs(ci
, 1, snapc
);
172 ceph_put_snap_context(snapc
);
174 ClearPagePrivate(page
);
176 dout("%p invalidatepage %p idx %lu partial dirty page\n",
177 inode
, page
, page
->index
);
181 /* just a sanity check */
182 static int ceph_releasepage(struct page
*page
, gfp_t g
)
184 struct inode
*inode
= page
->mapping
? page
->mapping
->host
: NULL
;
185 dout("%p releasepage %p idx %lu\n", inode
, page
, page
->index
);
186 WARN_ON(PageDirty(page
));
187 WARN_ON(page
->private);
188 WARN_ON(PagePrivate(page
));
193 * read a single page, without unlocking it.
195 static int readpage_nounlock(struct file
*filp
, struct page
*page
)
197 struct inode
*inode
= filp
->f_dentry
->d_inode
;
198 struct ceph_inode_info
*ci
= ceph_inode(inode
);
199 struct ceph_osd_client
*osdc
= &ceph_inode_to_client(inode
)->osdc
;
201 u64 len
= PAGE_CACHE_SIZE
;
203 dout("readpage inode %p file %p page %p index %lu\n",
204 inode
, filp
, page
, page
->index
);
205 err
= ceph_osdc_readpages(osdc
, ceph_vino(inode
), &ci
->i_layout
,
206 page
->index
<< PAGE_CACHE_SHIFT
, &len
,
207 ci
->i_truncate_seq
, ci
->i_truncate_size
,
214 } else if (err
< PAGE_CACHE_SIZE
) {
215 /* zero fill remainder of page */
216 zero_user_segment(page
, err
, PAGE_CACHE_SIZE
);
218 SetPageUptodate(page
);
221 return err
< 0 ? err
: 0;
224 static int ceph_readpage(struct file
*filp
, struct page
*page
)
226 int r
= readpage_nounlock(filp
, page
);
232 * Build a vector of contiguous pages from the provided page list.
234 static struct page
**page_vector_from_list(struct list_head
*page_list
,
239 int next_index
, contig_pages
= 0;
241 /* build page vector */
242 pages
= kmalloc(sizeof(*pages
) * *nr_pages
, GFP_NOFS
);
244 return ERR_PTR(-ENOMEM
);
246 BUG_ON(list_empty(page_list
));
247 next_index
= list_entry(page_list
->prev
, struct page
, lru
)->index
;
248 list_for_each_entry_reverse(page
, page_list
, lru
) {
249 if (page
->index
== next_index
) {
250 dout("readpages page %d %p\n", contig_pages
, page
);
251 pages
[contig_pages
] = page
;
258 *nr_pages
= contig_pages
;
263 * Read multiple pages. Leave pages we don't read + unlock in page_list;
264 * the caller (VM) cleans them up.
266 static int ceph_readpages(struct file
*file
, struct address_space
*mapping
,
267 struct list_head
*page_list
, unsigned nr_pages
)
269 struct inode
*inode
= file
->f_dentry
->d_inode
;
270 struct ceph_inode_info
*ci
= ceph_inode(inode
);
271 struct ceph_osd_client
*osdc
= &ceph_inode_to_client(inode
)->osdc
;
278 dout("readpages %p file %p nr_pages %d\n",
279 inode
, file
, nr_pages
);
281 pages
= page_vector_from_list(page_list
, &nr_pages
);
283 return PTR_ERR(pages
);
285 /* guess read extent */
286 offset
= pages
[0]->index
<< PAGE_CACHE_SHIFT
;
287 len
= nr_pages
<< PAGE_CACHE_SHIFT
;
288 rc
= ceph_osdc_readpages(osdc
, ceph_vino(inode
), &ci
->i_layout
,
290 ci
->i_truncate_seq
, ci
->i_truncate_size
,
297 /* set uptodate and add to lru in pagevec-sized chunks */
298 pagevec_init(&pvec
, 0);
299 for (; !list_empty(page_list
) && len
> 0;
300 rc
-= PAGE_CACHE_SIZE
, len
-= PAGE_CACHE_SIZE
) {
302 list_entry(page_list
->prev
, struct page
, lru
);
304 list_del(&page
->lru
);
306 if (rc
< (int)PAGE_CACHE_SIZE
) {
307 /* zero (remainder of) page */
308 int s
= rc
< 0 ? 0 : rc
;
309 zero_user_segment(page
, s
, PAGE_CACHE_SIZE
);
312 if (add_to_page_cache(page
, mapping
, page
->index
, GFP_NOFS
)) {
313 page_cache_release(page
);
314 dout("readpages %p add_to_page_cache failed %p\n",
318 dout("readpages %p adding %p idx %lu\n", inode
, page
,
320 flush_dcache_page(page
);
321 SetPageUptodate(page
);
323 if (pagevec_add(&pvec
, page
) == 0)
324 pagevec_lru_add_file(&pvec
); /* add to lru */
326 pagevec_lru_add_file(&pvec
);
335 * Get ref for the oldest snapc for an inode with dirty data... that is, the
336 * only snap context we are allowed to write back.
338 * Caller holds i_lock.
340 static struct ceph_snap_context
*__get_oldest_context(struct inode
*inode
,
343 struct ceph_inode_info
*ci
= ceph_inode(inode
);
344 struct ceph_snap_context
*snapc
= NULL
;
345 struct ceph_cap_snap
*capsnap
= NULL
;
347 list_for_each_entry(capsnap
, &ci
->i_cap_snaps
, ci_item
) {
348 dout(" cap_snap %p snapc %p has %d dirty pages\n", capsnap
,
349 capsnap
->context
, capsnap
->dirty_pages
);
350 if (capsnap
->dirty_pages
) {
351 snapc
= ceph_get_snap_context(capsnap
->context
);
353 *snap_size
= capsnap
->size
;
357 if (!snapc
&& ci
->i_snap_realm
) {
358 snapc
= ceph_get_snap_context(ci
->i_snap_realm
->cached_context
);
359 dout(" head snapc %p has %d dirty pages\n",
360 snapc
, ci
->i_wrbuffer_ref_head
);
365 static struct ceph_snap_context
*get_oldest_context(struct inode
*inode
,
368 struct ceph_snap_context
*snapc
= NULL
;
370 spin_lock(&inode
->i_lock
);
371 snapc
= __get_oldest_context(inode
, snap_size
);
372 spin_unlock(&inode
->i_lock
);
377 * Write a single page, but leave the page locked.
379 * If we get a write error, set the page error bit, but still adjust the
380 * dirty page accounting (i.e., page is no longer dirty).
382 static int writepage_nounlock(struct page
*page
, struct writeback_control
*wbc
)
385 struct ceph_inode_info
*ci
;
386 struct ceph_client
*client
;
387 struct ceph_osd_client
*osdc
;
388 loff_t page_off
= page
->index
<< PAGE_CACHE_SHIFT
;
389 int len
= PAGE_CACHE_SIZE
;
392 struct ceph_snap_context
*snapc
;
396 dout("writepage %p idx %lu\n", page
, page
->index
);
398 if (!page
->mapping
|| !page
->mapping
->host
) {
399 dout("writepage %p - no mapping\n", page
);
402 inode
= page
->mapping
->host
;
403 ci
= ceph_inode(inode
);
404 client
= ceph_inode_to_client(inode
);
405 osdc
= &client
->osdc
;
407 /* verify this is a writeable snap context */
408 snapc
= (void *)page
->private;
410 dout("writepage %p page %p not dirty?\n", inode
, page
);
413 if (snapc
!= get_oldest_context(inode
, &snap_size
)) {
414 dout("writepage %p page %p snapc %p not writeable - noop\n",
415 inode
, page
, (void *)page
->private);
416 /* we should only noop if called by kswapd */
417 WARN_ON((current
->flags
& PF_MEMALLOC
) == 0);
421 /* is this a partial page at end of file? */
425 i_size
= i_size_read(inode
);
426 if (i_size
< page_off
+ len
)
427 len
= i_size
- page_off
;
429 dout("writepage %p page %p index %lu on %llu~%u\n",
430 inode
, page
, page
->index
, page_off
, len
);
432 writeback_stat
= atomic_long_inc_return(&client
->writeback_count
);
434 CONGESTION_ON_THRESH(client
->mount_args
->congestion_kb
))
435 set_bdi_congested(&client
->backing_dev_info
, BLK_RW_ASYNC
);
437 set_page_writeback(page
);
438 err
= ceph_osdc_writepages(osdc
, ceph_vino(inode
),
439 &ci
->i_layout
, snapc
,
441 ci
->i_truncate_seq
, ci
->i_truncate_size
,
443 &page
, 1, 0, 0, true);
445 dout("writepage setting page/mapping error %d %p\n", err
, page
);
447 mapping_set_error(&inode
->i_data
, err
);
449 wbc
->pages_skipped
++;
451 dout("writepage cleaned page %p\n", page
);
452 err
= 0; /* vfs expects us to return 0 */
455 ClearPagePrivate(page
);
456 end_page_writeback(page
);
457 ceph_put_wrbuffer_cap_refs(ci
, 1, snapc
);
458 ceph_put_snap_context(snapc
);
463 static int ceph_writepage(struct page
*page
, struct writeback_control
*wbc
)
466 struct inode
*inode
= page
->mapping
->host
;
469 err
= writepage_nounlock(page
, wbc
);
477 * lame release_pages helper. release_pages() isn't exported to
480 static void ceph_release_pages(struct page
**pages
, int num
)
485 pagevec_init(&pvec
, 0);
486 for (i
= 0; i
< num
; i
++) {
487 if (pagevec_add(&pvec
, pages
[i
]) == 0)
488 pagevec_release(&pvec
);
490 pagevec_release(&pvec
);
495 * async writeback completion handler.
497 * If we get an error, set the mapping error bit, but not the individual
500 static void writepages_finish(struct ceph_osd_request
*req
,
501 struct ceph_msg
*msg
)
503 struct inode
*inode
= req
->r_inode
;
504 struct ceph_osd_reply_head
*replyhead
;
505 struct ceph_osd_op
*op
;
506 struct ceph_inode_info
*ci
= ceph_inode(inode
);
508 loff_t offset
= req
->r_pages
[0]->index
<< PAGE_CACHE_SHIFT
;
511 struct ceph_snap_context
*snapc
= req
->r_snapc
;
512 struct address_space
*mapping
= inode
->i_mapping
;
513 struct writeback_control
*wbc
= req
->r_wbc
;
516 struct ceph_client
*client
= ceph_inode_to_client(inode
);
520 replyhead
= msg
->front
.iov_base
;
521 WARN_ON(le32_to_cpu(replyhead
->num_ops
) == 0);
522 op
= (void *)(replyhead
+ 1);
523 rc
= le32_to_cpu(replyhead
->result
);
524 bytes
= le64_to_cpu(op
->extent
.length
);
527 wrote
= (bytes
+ (offset
& ~PAGE_CACHE_MASK
) + ~PAGE_CACHE_MASK
)
529 WARN_ON(wrote
!= req
->r_num_pages
);
532 mapping_set_error(mapping
, rc
);
534 dout("writepages_finish %p rc %d bytes %llu wrote %d (pages)\n",
535 inode
, rc
, bytes
, wrote
);
537 /* clean all pages */
538 for (i
= 0; i
< req
->r_num_pages
; i
++) {
539 page
= req
->r_pages
[i
];
541 WARN_ON(!PageUptodate(page
));
544 atomic_long_dec_return(&client
->writeback_count
);
546 CONGESTION_OFF_THRESH(client
->mount_args
->congestion_kb
))
547 clear_bdi_congested(&client
->backing_dev_info
,
551 dout("inode %p skipping page %p\n", inode
, page
);
552 wbc
->pages_skipped
++;
555 ClearPagePrivate(page
);
556 ceph_put_snap_context(snapc
);
557 dout("unlocking %d %p\n", i
, page
);
558 end_page_writeback(page
);
561 dout("%p wrote+cleaned %d pages\n", inode
, wrote
);
562 ceph_put_wrbuffer_cap_refs(ci
, req
->r_num_pages
, snapc
);
564 ceph_release_pages(req
->r_pages
, req
->r_num_pages
);
565 if (req
->r_pages_from_pool
)
566 mempool_free(req
->r_pages
,
567 ceph_client(inode
->i_sb
)->wb_pagevec_pool
);
570 ceph_osdc_put_request(req
);
574 * allocate a page vec, either directly, or if necessary, via a the
575 * mempool. we avoid the mempool if we can because req->r_num_pages
576 * may be less than the maximum write size.
578 static void alloc_page_vec(struct ceph_client
*client
,
579 struct ceph_osd_request
*req
)
581 req
->r_pages
= kmalloc(sizeof(struct page
*) * req
->r_num_pages
,
584 req
->r_pages
= mempool_alloc(client
->wb_pagevec_pool
, GFP_NOFS
);
585 req
->r_pages_from_pool
= 1;
586 WARN_ON(!req
->r_pages
);
591 * initiate async writeback
593 static int ceph_writepages_start(struct address_space
*mapping
,
594 struct writeback_control
*wbc
)
596 struct inode
*inode
= mapping
->host
;
597 struct backing_dev_info
*bdi
= mapping
->backing_dev_info
;
598 struct ceph_inode_info
*ci
= ceph_inode(inode
);
599 struct ceph_client
*client
;
600 pgoff_t index
, start
, end
;
603 pgoff_t max_pages
= 0, max_pages_ever
= 0;
604 struct ceph_snap_context
*snapc
= NULL
, *last_snapc
= NULL
;
608 unsigned wsize
= 1 << inode
->i_blkbits
;
609 struct ceph_osd_request
*req
= NULL
;
614 * Include a 'sync' in the OSD request if this is a data
615 * integrity write (e.g., O_SYNC write or fsync()), or if our
616 * cap is being revoked.
618 do_sync
= wbc
->sync_mode
== WB_SYNC_ALL
;
619 if (ceph_caps_revoking(ci
, CEPH_CAP_FILE_BUFFER
))
621 dout("writepages_start %p dosync=%d (mode=%s)\n",
623 wbc
->sync_mode
== WB_SYNC_NONE
? "NONE" :
624 (wbc
->sync_mode
== WB_SYNC_ALL
? "ALL" : "HOLD"));
626 client
= ceph_inode_to_client(inode
);
627 if (client
->mount_state
== CEPH_MOUNT_SHUTDOWN
) {
628 pr_warning("writepage_start %p on forced umount\n", inode
);
629 return -EIO
; /* we're in a forced umount, don't write! */
631 if (client
->mount_args
->wsize
&& client
->mount_args
->wsize
< wsize
)
632 wsize
= client
->mount_args
->wsize
;
633 if (wsize
< PAGE_CACHE_SIZE
)
634 wsize
= PAGE_CACHE_SIZE
;
635 max_pages_ever
= wsize
>> PAGE_CACHE_SHIFT
;
637 pagevec_init(&pvec
, 0);
640 if (wbc
->nonblocking
&& bdi_write_congested(bdi
)) {
641 dout(" writepages congested\n");
642 wbc
->encountered_congestion
= 1;
646 /* where to start/end? */
647 if (wbc
->range_cyclic
) {
648 start
= mapping
->writeback_index
; /* Start from prev offset */
650 dout(" cyclic, start at %lu\n", start
);
652 start
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
653 end
= wbc
->range_end
>> PAGE_CACHE_SHIFT
;
654 if (wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
)
657 dout(" not cyclic, %lu to %lu\n", start
, end
);
662 /* find oldest snap context with dirty data */
663 ceph_put_snap_context(snapc
);
664 snapc
= get_oldest_context(inode
, &snap_size
);
666 /* hmm, why does writepages get called when there
668 dout(" no snap context with dirty data?\n");
671 dout(" oldest snapc is %p seq %lld (%d snaps)\n",
672 snapc
, snapc
->seq
, snapc
->num_snaps
);
673 if (last_snapc
&& snapc
!= last_snapc
) {
674 /* if we switched to a newer snapc, restart our scan at the
675 * start of the original file range. */
676 dout(" snapc differs from last pass, restarting at %lu\n",
682 while (!done
&& index
<= end
) {
686 int pvec_pages
, locked_pages
;
690 struct ceph_osd_request_head
*reqhead
;
691 struct ceph_osd_op
*op
;
696 max_pages
= max_pages_ever
;
700 want
= min(end
- index
,
701 min((pgoff_t
)PAGEVEC_SIZE
,
702 max_pages
- (pgoff_t
)locked_pages
) - 1)
704 pvec_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
,
707 dout("pagevec_lookup_tag got %d\n", pvec_pages
);
708 if (!pvec_pages
&& !locked_pages
)
710 for (i
= 0; i
< pvec_pages
&& locked_pages
< max_pages
; i
++) {
711 page
= pvec
.pages
[i
];
712 dout("? %p idx %lu\n", page
, page
->index
);
713 if (locked_pages
== 0)
714 lock_page(page
); /* first page */
715 else if (!trylock_page(page
))
718 /* only dirty pages, or our accounting breaks */
719 if (unlikely(!PageDirty(page
)) ||
720 unlikely(page
->mapping
!= mapping
)) {
721 dout("!dirty or !mapping %p\n", page
);
725 if (!wbc
->range_cyclic
&& page
->index
> end
) {
726 dout("end of range %p\n", page
);
731 if (next
&& (page
->index
!= next
)) {
732 dout("not consecutive %p\n", page
);
736 if (wbc
->sync_mode
!= WB_SYNC_NONE
) {
737 dout("waiting on writeback %p\n", page
);
738 wait_on_page_writeback(page
);
740 if ((snap_size
&& page_offset(page
) > snap_size
) ||
742 page_offset(page
) > i_size_read(inode
))) {
743 dout("%p page eof %llu\n", page
, snap_size
?
744 snap_size
: i_size_read(inode
));
749 if (PageWriteback(page
)) {
750 dout("%p under writeback\n", page
);
755 /* only if matching snap context */
756 if (snapc
!= (void *)page
->private) {
757 dout("page snapc %p != oldest %p\n",
758 (void *)page
->private, snapc
);
761 continue; /* keep looking for snap */
765 if (!clear_page_dirty_for_io(page
)) {
766 dout("%p !clear_page_dirty_for_io\n", page
);
772 if (locked_pages
== 0) {
773 /* prepare async write request */
774 offset
= page
->index
<< PAGE_CACHE_SHIFT
;
776 req
= ceph_osdc_new_request(&client
->osdc
,
781 CEPH_OSD_FLAG_WRITE
|
782 CEPH_OSD_FLAG_ONDISK
,
786 &inode
->i_mtime
, true, 1);
787 max_pages
= req
->r_num_pages
;
789 alloc_page_vec(client
, req
);
790 req
->r_callback
= writepages_finish
;
791 req
->r_inode
= inode
;
795 /* note position of first page in pvec */
798 dout("%p will write page %p idx %lu\n",
799 inode
, page
, page
->index
);
801 writeback_stat
= atomic_long_inc_return(&client
->writeback_count
);
802 if (writeback_stat
> CONGESTION_ON_THRESH(client
->mount_args
->congestion_kb
)) {
803 set_bdi_congested(&client
->backing_dev_info
, BLK_RW_ASYNC
);
806 set_page_writeback(page
);
807 req
->r_pages
[locked_pages
] = page
;
809 next
= page
->index
+ 1;
812 /* did we get anything? */
814 goto release_pvec_pages
;
817 BUG_ON(!locked_pages
|| first
< 0);
819 if (pvec_pages
&& i
== pvec_pages
&&
820 locked_pages
< max_pages
) {
821 dout("reached end pvec, trying for more\n");
822 pagevec_reinit(&pvec
);
826 /* shift unused pages over in the pvec... we
827 * will need to release them below. */
828 for (j
= i
; j
< pvec_pages
; j
++) {
829 dout(" pvec leftover page %p\n",
831 pvec
.pages
[j
-i
+first
] = pvec
.pages
[j
];
836 /* submit the write */
837 offset
= req
->r_pages
[0]->index
<< PAGE_CACHE_SHIFT
;
838 len
= min((snap_size
? snap_size
: i_size_read(inode
)) - offset
,
839 (u64
)locked_pages
<< PAGE_CACHE_SHIFT
);
840 dout("writepages got %d pages at %llu~%llu\n",
841 locked_pages
, offset
, len
);
843 /* revise final length, page count */
844 req
->r_num_pages
= locked_pages
;
845 reqhead
= req
->r_request
->front
.iov_base
;
846 op
= (void *)(reqhead
+ 1);
847 op
->extent
.length
= cpu_to_le64(len
);
848 op
->payload_len
= cpu_to_le32(len
);
849 req
->r_request
->hdr
.data_len
= cpu_to_le32(len
);
851 ceph_osdc_start_request(&client
->osdc
, req
, true);
856 wbc
->nr_to_write
-= locked_pages
;
857 if (wbc
->nr_to_write
<= 0)
861 dout("pagevec_release on %d pages (%p)\n", (int)pvec
.nr
,
862 pvec
.nr
? pvec
.pages
[0] : NULL
);
863 pagevec_release(&pvec
);
865 if (locked_pages
&& !done
)
869 if (should_loop
&& !done
) {
870 /* more to do; loop back to beginning of file */
871 dout("writepages looping back to beginning of file\n");
877 if (wbc
->range_cyclic
|| (range_whole
&& wbc
->nr_to_write
> 0))
878 mapping
->writeback_index
= index
;
882 ceph_osdc_put_request(req
);
884 rc
= 0; /* vfs expects us to return 0 */
885 ceph_put_snap_context(snapc
);
886 dout("writepages done, rc = %d\n", rc
);
894 * See if a given @snapc is either writeable, or already written.
896 static int context_is_writeable_or_written(struct inode
*inode
,
897 struct ceph_snap_context
*snapc
)
899 struct ceph_snap_context
*oldest
= get_oldest_context(inode
, NULL
);
900 return !oldest
|| snapc
->seq
<= oldest
->seq
;
904 * We are only allowed to write into/dirty the page if the page is
905 * clean, or already dirty within the same snap context.
907 static int ceph_write_begin(struct file
*file
, struct address_space
*mapping
,
908 loff_t pos
, unsigned len
, unsigned flags
,
909 struct page
**pagep
, void **fsdata
)
911 struct inode
*inode
= file
->f_dentry
->d_inode
;
912 struct ceph_inode_info
*ci
= ceph_inode(inode
);
913 struct ceph_mds_client
*mdsc
= &ceph_inode_to_client(inode
)->mdsc
;
915 pgoff_t index
= pos
>> PAGE_CACHE_SHIFT
;
916 loff_t page_off
= pos
& PAGE_CACHE_MASK
;
917 int pos_in_page
= pos
& ~PAGE_CACHE_MASK
;
918 int end_in_page
= pos_in_page
+ len
;
920 struct ceph_snap_context
*snapc
;
925 page
= grab_cache_page_write_begin(mapping
, index
, 0);
930 dout("write_begin file %p inode %p page %p %d~%d\n", file
,
931 inode
, page
, (int)pos
, (int)len
);
934 /* writepages currently holds page lock, but if we change that later, */
935 wait_on_page_writeback(page
);
937 /* check snap context */
938 BUG_ON(!ci
->i_snap_realm
);
939 down_read(&mdsc
->snap_rwsem
);
940 BUG_ON(!ci
->i_snap_realm
->cached_context
);
942 (void *)page
->private != ci
->i_snap_realm
->cached_context
) {
944 * this page is already dirty in another (older) snap
945 * context! is it writeable now?
947 snapc
= get_oldest_context(inode
, NULL
);
948 up_read(&mdsc
->snap_rwsem
);
950 if (snapc
!= (void *)page
->private) {
951 dout(" page %p snapc %p not current or oldest\n",
952 page
, (void *)page
->private);
954 * queue for writeback, and wait for snapc to
955 * be writeable or written
957 snapc
= ceph_get_snap_context((void *)page
->private);
959 if (ceph_queue_writeback(inode
))
961 wait_event_interruptible(ci
->i_cap_wq
,
962 context_is_writeable_or_written(inode
, snapc
));
963 ceph_put_snap_context(snapc
);
967 /* yay, writeable, do it now (without dropping page lock) */
968 dout(" page %p snapc %p not current, but oldest\n",
970 if (!clear_page_dirty_for_io(page
))
972 r
= writepage_nounlock(page
, NULL
);
978 if (PageUptodate(page
)) {
979 dout(" page %p already uptodate\n", page
);
984 if (pos_in_page
== 0 && len
== PAGE_CACHE_SIZE
)
987 /* past end of file? */
988 i_size
= inode
->i_size
; /* caller holds i_mutex */
990 if (i_size
+ len
> inode
->i_sb
->s_maxbytes
) {
991 /* file is too big */
996 if (page_off
>= i_size
||
997 (pos_in_page
== 0 && (pos
+len
) >= i_size
&&
998 end_in_page
- pos_in_page
!= PAGE_CACHE_SIZE
)) {
999 dout(" zeroing %p 0 - %d and %d - %d\n",
1000 page
, pos_in_page
, end_in_page
, (int)PAGE_CACHE_SIZE
);
1001 zero_user_segments(page
,
1003 end_in_page
, PAGE_CACHE_SIZE
);
1007 /* we need to read it. */
1008 up_read(&mdsc
->snap_rwsem
);
1009 r
= readpage_nounlock(file
, page
);
1015 up_read(&mdsc
->snap_rwsem
);
1022 * we don't do anything in here that simple_write_end doesn't do
1023 * except adjust dirty page accounting and drop read lock on
1026 static int ceph_write_end(struct file
*file
, struct address_space
*mapping
,
1027 loff_t pos
, unsigned len
, unsigned copied
,
1028 struct page
*page
, void *fsdata
)
1030 struct inode
*inode
= file
->f_dentry
->d_inode
;
1031 struct ceph_client
*client
= ceph_inode_to_client(inode
);
1032 struct ceph_mds_client
*mdsc
= &client
->mdsc
;
1033 unsigned from
= pos
& (PAGE_CACHE_SIZE
- 1);
1036 dout("write_end file %p inode %p page %p %d~%d (%d)\n", file
,
1037 inode
, page
, (int)pos
, (int)copied
, (int)len
);
1039 /* zero the stale part of the page if we did a short copy */
1041 zero_user_segment(page
, from
+copied
, len
);
1043 /* did file size increase? */
1044 /* (no need for i_size_read(); we caller holds i_mutex */
1045 if (pos
+copied
> inode
->i_size
)
1046 check_cap
= ceph_inode_set_size(inode
, pos
+copied
);
1048 if (!PageUptodate(page
))
1049 SetPageUptodate(page
);
1051 set_page_dirty(page
);
1054 up_read(&mdsc
->snap_rwsem
);
1055 page_cache_release(page
);
1058 ceph_check_caps(ceph_inode(inode
), CHECK_CAPS_AUTHONLY
, NULL
);
1064 * we set .direct_IO to indicate direct io is supported, but since we
1065 * intercept O_DIRECT reads and writes early, this function should
1068 static ssize_t
ceph_direct_io(int rw
, struct kiocb
*iocb
,
1069 const struct iovec
*iov
,
1070 loff_t pos
, unsigned long nr_segs
)
1076 const struct address_space_operations ceph_aops
= {
1077 .readpage
= ceph_readpage
,
1078 .readpages
= ceph_readpages
,
1079 .writepage
= ceph_writepage
,
1080 .writepages
= ceph_writepages_start
,
1081 .write_begin
= ceph_write_begin
,
1082 .write_end
= ceph_write_end
,
1083 .set_page_dirty
= ceph_set_page_dirty
,
1084 .invalidatepage
= ceph_invalidatepage
,
1085 .releasepage
= ceph_releasepage
,
1086 .direct_IO
= ceph_direct_io
,
1095 * Reuse write_begin here for simplicity.
1097 static int ceph_page_mkwrite(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
1099 struct inode
*inode
= vma
->vm_file
->f_dentry
->d_inode
;
1100 struct page
*page
= vmf
->page
;
1101 struct ceph_mds_client
*mdsc
= &ceph_inode_to_client(inode
)->mdsc
;
1102 loff_t off
= page
->index
<< PAGE_CACHE_SHIFT
;
1104 struct page
*locked_page
= NULL
;
1105 void *fsdata
= NULL
;
1108 size
= i_size_read(inode
);
1109 if (off
+ PAGE_CACHE_SIZE
<= size
)
1110 len
= PAGE_CACHE_SIZE
;
1112 len
= size
& ~PAGE_CACHE_MASK
;
1114 dout("page_mkwrite %p %llu~%llu page %p idx %lu\n", inode
,
1115 off
, len
, page
, page
->index
);
1116 ret
= ceph_write_begin(vma
->vm_file
, inode
->i_mapping
, off
, len
, 0,
1117 &locked_page
, &fsdata
);
1118 WARN_ON(page
!= locked_page
);
1121 * doing the following, instead of calling
1122 * ceph_write_end. Note that we keep the
1125 set_page_dirty(page
);
1126 up_read(&mdsc
->snap_rwsem
);
1127 page_cache_release(page
);
1128 ret
= VM_FAULT_LOCKED
;
1130 ret
= VM_FAULT_SIGBUS
;
1132 dout("page_mkwrite %p %llu~%llu = %d\n", inode
, off
, len
, ret
);
1136 static struct vm_operations_struct ceph_vmops
= {
1137 .fault
= filemap_fault
,
1138 .page_mkwrite
= ceph_page_mkwrite
,
1141 int ceph_mmap(struct file
*file
, struct vm_area_struct
*vma
)
1143 struct address_space
*mapping
= file
->f_mapping
;
1145 if (!mapping
->a_ops
->readpage
)
1147 file_accessed(file
);
1148 vma
->vm_ops
= &ceph_vmops
;
1149 vma
->vm_flags
|= VM_CAN_NONLINEAR
;