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 static struct ceph_snap_context
*get_oldest_context(struct inode
*inode
,
344 struct ceph_inode_info
*ci
= ceph_inode(inode
);
345 struct ceph_snap_context
*snapc
= NULL
;
346 struct ceph_cap_snap
*capsnap
= NULL
;
348 spin_lock(&inode
->i_lock
);
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_head_snapc
) {
360 snapc
= ceph_get_snap_context(ci
->i_head_snapc
);
361 dout(" head snapc %p has %d dirty pages\n",
362 snapc
, ci
->i_wrbuffer_ref_head
);
364 spin_unlock(&inode
->i_lock
);
369 * Write a single page, but leave the page locked.
371 * If we get a write error, set the page error bit, but still adjust the
372 * dirty page accounting (i.e., page is no longer dirty).
374 static int writepage_nounlock(struct page
*page
, struct writeback_control
*wbc
)
377 struct ceph_inode_info
*ci
;
378 struct ceph_client
*client
;
379 struct ceph_osd_client
*osdc
;
380 loff_t page_off
= page
->index
<< PAGE_CACHE_SHIFT
;
381 int len
= PAGE_CACHE_SIZE
;
384 struct ceph_snap_context
*snapc
, *oldest
;
388 dout("writepage %p idx %lu\n", page
, page
->index
);
390 if (!page
->mapping
|| !page
->mapping
->host
) {
391 dout("writepage %p - no mapping\n", page
);
394 inode
= page
->mapping
->host
;
395 ci
= ceph_inode(inode
);
396 client
= ceph_inode_to_client(inode
);
397 osdc
= &client
->osdc
;
399 /* verify this is a writeable snap context */
400 snapc
= (void *)page
->private;
402 dout("writepage %p page %p not dirty?\n", inode
, page
);
405 oldest
= get_oldest_context(inode
, &snap_size
);
406 if (snapc
->seq
> oldest
->seq
) {
407 dout("writepage %p page %p snapc %p not writeable - noop\n",
408 inode
, page
, (void *)page
->private);
409 /* we should only noop if called by kswapd */
410 WARN_ON((current
->flags
& PF_MEMALLOC
) == 0);
411 ceph_put_snap_context(oldest
);
414 ceph_put_snap_context(oldest
);
416 /* is this a partial page at end of file? */
420 i_size
= i_size_read(inode
);
421 if (i_size
< page_off
+ len
)
422 len
= i_size
- page_off
;
424 dout("writepage %p page %p index %lu on %llu~%u\n",
425 inode
, page
, page
->index
, page_off
, len
);
427 writeback_stat
= atomic_long_inc_return(&client
->writeback_count
);
429 CONGESTION_ON_THRESH(client
->mount_args
->congestion_kb
))
430 set_bdi_congested(&client
->backing_dev_info
, BLK_RW_ASYNC
);
432 set_page_writeback(page
);
433 err
= ceph_osdc_writepages(osdc
, ceph_vino(inode
),
434 &ci
->i_layout
, snapc
,
436 ci
->i_truncate_seq
, ci
->i_truncate_size
,
438 &page
, 1, 0, 0, true);
440 dout("writepage setting page/mapping error %d %p\n", err
, page
);
442 mapping_set_error(&inode
->i_data
, err
);
444 wbc
->pages_skipped
++;
446 dout("writepage cleaned page %p\n", page
);
447 err
= 0; /* vfs expects us to return 0 */
450 ClearPagePrivate(page
);
451 end_page_writeback(page
);
452 ceph_put_wrbuffer_cap_refs(ci
, 1, snapc
);
453 ceph_put_snap_context(snapc
); /* page's reference */
458 static int ceph_writepage(struct page
*page
, struct writeback_control
*wbc
)
461 struct inode
*inode
= page
->mapping
->host
;
464 err
= writepage_nounlock(page
, wbc
);
472 * lame release_pages helper. release_pages() isn't exported to
475 static void ceph_release_pages(struct page
**pages
, int num
)
480 pagevec_init(&pvec
, 0);
481 for (i
= 0; i
< num
; i
++) {
482 if (pagevec_add(&pvec
, pages
[i
]) == 0)
483 pagevec_release(&pvec
);
485 pagevec_release(&pvec
);
490 * async writeback completion handler.
492 * If we get an error, set the mapping error bit, but not the individual
495 static void writepages_finish(struct ceph_osd_request
*req
,
496 struct ceph_msg
*msg
)
498 struct inode
*inode
= req
->r_inode
;
499 struct ceph_osd_reply_head
*replyhead
;
500 struct ceph_osd_op
*op
;
501 struct ceph_inode_info
*ci
= ceph_inode(inode
);
505 struct ceph_snap_context
*snapc
= req
->r_snapc
;
506 struct address_space
*mapping
= inode
->i_mapping
;
509 struct ceph_client
*client
= ceph_inode_to_client(inode
);
511 unsigned issued
= ceph_caps_issued(ci
);
514 replyhead
= msg
->front
.iov_base
;
515 WARN_ON(le32_to_cpu(replyhead
->num_ops
) == 0);
516 op
= (void *)(replyhead
+ 1);
517 rc
= le32_to_cpu(replyhead
->result
);
518 bytes
= le64_to_cpu(op
->extent
.length
);
522 * Assume we wrote the pages we originally sent. The
523 * osd might reply with fewer pages if our writeback
524 * raced with a truncation and was adjusted at the osd,
525 * so don't believe the reply.
527 wrote
= req
->r_num_pages
;
530 mapping_set_error(mapping
, rc
);
532 dout("writepages_finish %p rc %d bytes %llu wrote %d (pages)\n",
533 inode
, rc
, bytes
, wrote
);
535 /* clean all pages */
536 for (i
= 0; i
< req
->r_num_pages
; i
++) {
537 page
= req
->r_pages
[i
];
539 WARN_ON(!PageUptodate(page
));
542 atomic_long_dec_return(&client
->writeback_count
);
544 CONGESTION_OFF_THRESH(client
->mount_args
->congestion_kb
))
545 clear_bdi_congested(&client
->backing_dev_info
,
548 ceph_put_snap_context((void *)page
->private);
550 ClearPagePrivate(page
);
551 dout("unlocking %d %p\n", i
, page
);
552 end_page_writeback(page
);
555 * We lost the cache cap, need to truncate the page before
556 * it is unlocked, otherwise we'd truncate it later in the
557 * page truncation thread, possibly losing some data that
560 if ((issued
& CEPH_CAP_FILE_CACHE
) == 0)
561 generic_error_remove_page(inode
->i_mapping
, page
);
565 dout("%p wrote+cleaned %d pages\n", inode
, wrote
);
566 ceph_put_wrbuffer_cap_refs(ci
, req
->r_num_pages
, snapc
);
568 ceph_release_pages(req
->r_pages
, req
->r_num_pages
);
569 if (req
->r_pages_from_pool
)
570 mempool_free(req
->r_pages
,
571 ceph_client(inode
->i_sb
)->wb_pagevec_pool
);
574 ceph_osdc_put_request(req
);
578 * allocate a page vec, either directly, or if necessary, via a the
579 * mempool. we avoid the mempool if we can because req->r_num_pages
580 * may be less than the maximum write size.
582 static void alloc_page_vec(struct ceph_client
*client
,
583 struct ceph_osd_request
*req
)
585 req
->r_pages
= kmalloc(sizeof(struct page
*) * req
->r_num_pages
,
588 req
->r_pages
= mempool_alloc(client
->wb_pagevec_pool
, GFP_NOFS
);
589 req
->r_pages_from_pool
= 1;
590 WARN_ON(!req
->r_pages
);
595 * initiate async writeback
597 static int ceph_writepages_start(struct address_space
*mapping
,
598 struct writeback_control
*wbc
)
600 struct inode
*inode
= mapping
->host
;
601 struct backing_dev_info
*bdi
= mapping
->backing_dev_info
;
602 struct ceph_inode_info
*ci
= ceph_inode(inode
);
603 struct ceph_client
*client
;
604 pgoff_t index
, start
, end
;
607 pgoff_t max_pages
= 0, max_pages_ever
= 0;
608 struct ceph_snap_context
*snapc
= NULL
, *last_snapc
= NULL
, *pgsnapc
;
612 unsigned wsize
= 1 << inode
->i_blkbits
;
613 struct ceph_osd_request
*req
= NULL
;
618 * Include a 'sync' in the OSD request if this is a data
619 * integrity write (e.g., O_SYNC write or fsync()), or if our
620 * cap is being revoked.
622 do_sync
= wbc
->sync_mode
== WB_SYNC_ALL
;
623 if (ceph_caps_revoking(ci
, CEPH_CAP_FILE_BUFFER
))
625 dout("writepages_start %p dosync=%d (mode=%s)\n",
627 wbc
->sync_mode
== WB_SYNC_NONE
? "NONE" :
628 (wbc
->sync_mode
== WB_SYNC_ALL
? "ALL" : "HOLD"));
630 client
= ceph_inode_to_client(inode
);
631 if (client
->mount_state
== CEPH_MOUNT_SHUTDOWN
) {
632 pr_warning("writepage_start %p on forced umount\n", inode
);
633 return -EIO
; /* we're in a forced umount, don't write! */
635 if (client
->mount_args
->wsize
&& client
->mount_args
->wsize
< wsize
)
636 wsize
= client
->mount_args
->wsize
;
637 if (wsize
< PAGE_CACHE_SIZE
)
638 wsize
= PAGE_CACHE_SIZE
;
639 max_pages_ever
= wsize
>> PAGE_CACHE_SHIFT
;
641 pagevec_init(&pvec
, 0);
644 if (wbc
->nonblocking
&& bdi_write_congested(bdi
)) {
645 dout(" writepages congested\n");
646 wbc
->encountered_congestion
= 1;
650 /* where to start/end? */
651 if (wbc
->range_cyclic
) {
652 start
= mapping
->writeback_index
; /* Start from prev offset */
654 dout(" cyclic, start at %lu\n", start
);
656 start
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
657 end
= wbc
->range_end
>> PAGE_CACHE_SHIFT
;
658 if (wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
)
661 dout(" not cyclic, %lu to %lu\n", start
, end
);
666 /* find oldest snap context with dirty data */
667 ceph_put_snap_context(snapc
);
668 snapc
= get_oldest_context(inode
, &snap_size
);
670 /* hmm, why does writepages get called when there
672 dout(" no snap context with dirty data?\n");
675 dout(" oldest snapc is %p seq %lld (%d snaps)\n",
676 snapc
, snapc
->seq
, snapc
->num_snaps
);
677 if (last_snapc
&& snapc
!= last_snapc
) {
678 /* if we switched to a newer snapc, restart our scan at the
679 * start of the original file range. */
680 dout(" snapc differs from last pass, restarting at %lu\n",
686 while (!done
&& index
<= end
) {
690 int pvec_pages
, locked_pages
;
694 struct ceph_osd_request_head
*reqhead
;
695 struct ceph_osd_op
*op
;
700 max_pages
= max_pages_ever
;
704 want
= min(end
- index
,
705 min((pgoff_t
)PAGEVEC_SIZE
,
706 max_pages
- (pgoff_t
)locked_pages
) - 1)
708 pvec_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
,
711 dout("pagevec_lookup_tag got %d\n", pvec_pages
);
712 if (!pvec_pages
&& !locked_pages
)
714 for (i
= 0; i
< pvec_pages
&& locked_pages
< max_pages
; i
++) {
715 page
= pvec
.pages
[i
];
716 dout("? %p idx %lu\n", page
, page
->index
);
717 if (locked_pages
== 0)
718 lock_page(page
); /* first page */
719 else if (!trylock_page(page
))
722 /* only dirty pages, or our accounting breaks */
723 if (unlikely(!PageDirty(page
)) ||
724 unlikely(page
->mapping
!= mapping
)) {
725 dout("!dirty or !mapping %p\n", page
);
729 if (!wbc
->range_cyclic
&& page
->index
> end
) {
730 dout("end of range %p\n", page
);
735 if (next
&& (page
->index
!= next
)) {
736 dout("not consecutive %p\n", page
);
740 if (wbc
->sync_mode
!= WB_SYNC_NONE
) {
741 dout("waiting on writeback %p\n", page
);
742 wait_on_page_writeback(page
);
744 if ((snap_size
&& page_offset(page
) > snap_size
) ||
746 page_offset(page
) > i_size_read(inode
))) {
747 dout("%p page eof %llu\n", page
, snap_size
?
748 snap_size
: i_size_read(inode
));
753 if (PageWriteback(page
)) {
754 dout("%p under writeback\n", page
);
759 /* only if matching snap context */
760 pgsnapc
= (void *)page
->private;
761 if (pgsnapc
->seq
> snapc
->seq
) {
762 dout("page snapc %p %lld > oldest %p %lld\n",
763 pgsnapc
, pgsnapc
->seq
, snapc
, snapc
->seq
);
766 continue; /* keep looking for snap */
770 if (!clear_page_dirty_for_io(page
)) {
771 dout("%p !clear_page_dirty_for_io\n", page
);
777 if (locked_pages
== 0) {
778 /* prepare async write request */
779 offset
= page
->index
<< PAGE_CACHE_SHIFT
;
781 req
= ceph_osdc_new_request(&client
->osdc
,
786 CEPH_OSD_FLAG_WRITE
|
787 CEPH_OSD_FLAG_ONDISK
,
791 &inode
->i_mtime
, true, 1);
792 max_pages
= req
->r_num_pages
;
794 alloc_page_vec(client
, req
);
795 req
->r_callback
= writepages_finish
;
796 req
->r_inode
= inode
;
799 /* note position of first page in pvec */
802 dout("%p will write page %p idx %lu\n",
803 inode
, page
, page
->index
);
805 writeback_stat
= atomic_long_inc_return(&client
->writeback_count
);
806 if (writeback_stat
> CONGESTION_ON_THRESH(client
->mount_args
->congestion_kb
)) {
807 set_bdi_congested(&client
->backing_dev_info
, BLK_RW_ASYNC
);
810 set_page_writeback(page
);
811 req
->r_pages
[locked_pages
] = page
;
813 next
= page
->index
+ 1;
816 /* did we get anything? */
818 goto release_pvec_pages
;
821 BUG_ON(!locked_pages
|| first
< 0);
823 if (pvec_pages
&& i
== pvec_pages
&&
824 locked_pages
< max_pages
) {
825 dout("reached end pvec, trying for more\n");
826 pagevec_reinit(&pvec
);
830 /* shift unused pages over in the pvec... we
831 * will need to release them below. */
832 for (j
= i
; j
< pvec_pages
; j
++) {
833 dout(" pvec leftover page %p\n",
835 pvec
.pages
[j
-i
+first
] = pvec
.pages
[j
];
840 /* submit the write */
841 offset
= req
->r_pages
[0]->index
<< PAGE_CACHE_SHIFT
;
842 len
= min((snap_size
? snap_size
: i_size_read(inode
)) - offset
,
843 (u64
)locked_pages
<< PAGE_CACHE_SHIFT
);
844 dout("writepages got %d pages at %llu~%llu\n",
845 locked_pages
, offset
, len
);
847 /* revise final length, page count */
848 req
->r_num_pages
= locked_pages
;
849 reqhead
= req
->r_request
->front
.iov_base
;
850 op
= (void *)(reqhead
+ 1);
851 op
->extent
.length
= cpu_to_le64(len
);
852 op
->payload_len
= cpu_to_le32(len
);
853 req
->r_request
->hdr
.data_len
= cpu_to_le32(len
);
855 ceph_osdc_start_request(&client
->osdc
, req
, true);
860 wbc
->nr_to_write
-= locked_pages
;
861 if (wbc
->nr_to_write
<= 0)
865 dout("pagevec_release on %d pages (%p)\n", (int)pvec
.nr
,
866 pvec
.nr
? pvec
.pages
[0] : NULL
);
867 pagevec_release(&pvec
);
869 if (locked_pages
&& !done
)
873 if (should_loop
&& !done
) {
874 /* more to do; loop back to beginning of file */
875 dout("writepages looping back to beginning of file\n");
881 if (wbc
->range_cyclic
|| (range_whole
&& wbc
->nr_to_write
> 0))
882 mapping
->writeback_index
= index
;
886 ceph_osdc_put_request(req
);
888 rc
= 0; /* vfs expects us to return 0 */
889 ceph_put_snap_context(snapc
);
890 dout("writepages done, rc = %d\n", rc
);
898 * See if a given @snapc is either writeable, or already written.
900 static int context_is_writeable_or_written(struct inode
*inode
,
901 struct ceph_snap_context
*snapc
)
903 struct ceph_snap_context
*oldest
= get_oldest_context(inode
, NULL
);
904 int ret
= !oldest
|| snapc
->seq
<= oldest
->seq
;
906 ceph_put_snap_context(oldest
);
911 * We are only allowed to write into/dirty the page if the page is
912 * clean, or already dirty within the same snap context.
914 * called with page locked.
915 * return success with page locked,
916 * or any failure (incl -EAGAIN) with page unlocked.
918 static int ceph_update_writeable_page(struct file
*file
,
919 loff_t pos
, unsigned len
,
922 struct inode
*inode
= file
->f_dentry
->d_inode
;
923 struct ceph_inode_info
*ci
= ceph_inode(inode
);
924 struct ceph_mds_client
*mdsc
= &ceph_inode_to_client(inode
)->mdsc
;
925 loff_t page_off
= pos
& PAGE_CACHE_MASK
;
926 int pos_in_page
= pos
& ~PAGE_CACHE_MASK
;
927 int end_in_page
= pos_in_page
+ len
;
930 struct ceph_snap_context
*snapc
, *oldest
;
933 /* writepages currently holds page lock, but if we change that later, */
934 wait_on_page_writeback(page
);
936 /* check snap context */
937 BUG_ON(!ci
->i_snap_realm
);
938 down_read(&mdsc
->snap_rwsem
);
939 BUG_ON(!ci
->i_snap_realm
->cached_context
);
940 snapc
= (void *)page
->private;
941 if (snapc
&& snapc
!= ci
->i_head_snapc
) {
943 * this page is already dirty in another (older) snap
944 * context! is it writeable now?
946 oldest
= get_oldest_context(inode
, NULL
);
947 up_read(&mdsc
->snap_rwsem
);
949 if (snapc
->seq
> oldest
->seq
) {
950 ceph_put_snap_context(oldest
);
951 dout(" page %p snapc %p not current or oldest\n",
954 * queue for writeback, and wait for snapc to
955 * be writeable or written
957 snapc
= ceph_get_snap_context(snapc
);
959 ceph_queue_writeback(inode
);
960 r
= wait_event_interruptible(ci
->i_cap_wq
,
961 context_is_writeable_or_written(inode
, snapc
));
962 ceph_put_snap_context(snapc
);
963 if (r
== -ERESTARTSYS
)
967 ceph_put_snap_context(oldest
);
969 /* yay, writeable, do it now (without dropping page lock) */
970 dout(" page %p snapc %p not current, but oldest\n",
972 if (!clear_page_dirty_for_io(page
))
974 r
= writepage_nounlock(page
, NULL
);
980 if (PageUptodate(page
)) {
981 dout(" page %p already uptodate\n", page
);
986 if (pos_in_page
== 0 && len
== PAGE_CACHE_SIZE
)
989 /* past end of file? */
990 i_size
= inode
->i_size
; /* caller holds i_mutex */
992 if (i_size
+ len
> inode
->i_sb
->s_maxbytes
) {
993 /* file is too big */
998 if (page_off
>= i_size
||
999 (pos_in_page
== 0 && (pos
+len
) >= i_size
&&
1000 end_in_page
- pos_in_page
!= PAGE_CACHE_SIZE
)) {
1001 dout(" zeroing %p 0 - %d and %d - %d\n",
1002 page
, pos_in_page
, end_in_page
, (int)PAGE_CACHE_SIZE
);
1003 zero_user_segments(page
,
1005 end_in_page
, PAGE_CACHE_SIZE
);
1009 /* we need to read it. */
1010 up_read(&mdsc
->snap_rwsem
);
1011 r
= readpage_nounlock(file
, page
);
1017 up_read(&mdsc
->snap_rwsem
);
1024 * We are only allowed to write into/dirty the page if the page is
1025 * clean, or already dirty within the same snap context.
1027 static int ceph_write_begin(struct file
*file
, struct address_space
*mapping
,
1028 loff_t pos
, unsigned len
, unsigned flags
,
1029 struct page
**pagep
, void **fsdata
)
1031 struct inode
*inode
= file
->f_dentry
->d_inode
;
1033 pgoff_t index
= pos
>> PAGE_CACHE_SHIFT
;
1038 page
= grab_cache_page_write_begin(mapping
, index
, 0);
1043 dout("write_begin file %p inode %p page %p %d~%d\n", file
,
1044 inode
, page
, (int)pos
, (int)len
);
1046 r
= ceph_update_writeable_page(file
, pos
, len
, page
);
1047 } while (r
== -EAGAIN
);
1053 * we don't do anything in here that simple_write_end doesn't do
1054 * except adjust dirty page accounting and drop read lock on
1057 static int ceph_write_end(struct file
*file
, struct address_space
*mapping
,
1058 loff_t pos
, unsigned len
, unsigned copied
,
1059 struct page
*page
, void *fsdata
)
1061 struct inode
*inode
= file
->f_dentry
->d_inode
;
1062 struct ceph_client
*client
= ceph_inode_to_client(inode
);
1063 struct ceph_mds_client
*mdsc
= &client
->mdsc
;
1064 unsigned from
= pos
& (PAGE_CACHE_SIZE
- 1);
1067 dout("write_end file %p inode %p page %p %d~%d (%d)\n", file
,
1068 inode
, page
, (int)pos
, (int)copied
, (int)len
);
1070 /* zero the stale part of the page if we did a short copy */
1072 zero_user_segment(page
, from
+copied
, len
);
1074 /* did file size increase? */
1075 /* (no need for i_size_read(); we caller holds i_mutex */
1076 if (pos
+copied
> inode
->i_size
)
1077 check_cap
= ceph_inode_set_size(inode
, pos
+copied
);
1079 if (!PageUptodate(page
))
1080 SetPageUptodate(page
);
1082 set_page_dirty(page
);
1085 up_read(&mdsc
->snap_rwsem
);
1086 page_cache_release(page
);
1089 ceph_check_caps(ceph_inode(inode
), CHECK_CAPS_AUTHONLY
, NULL
);
1095 * we set .direct_IO to indicate direct io is supported, but since we
1096 * intercept O_DIRECT reads and writes early, this function should
1099 static ssize_t
ceph_direct_io(int rw
, struct kiocb
*iocb
,
1100 const struct iovec
*iov
,
1101 loff_t pos
, unsigned long nr_segs
)
1107 const struct address_space_operations ceph_aops
= {
1108 .readpage
= ceph_readpage
,
1109 .readpages
= ceph_readpages
,
1110 .writepage
= ceph_writepage
,
1111 .writepages
= ceph_writepages_start
,
1112 .write_begin
= ceph_write_begin
,
1113 .write_end
= ceph_write_end
,
1114 .set_page_dirty
= ceph_set_page_dirty
,
1115 .invalidatepage
= ceph_invalidatepage
,
1116 .releasepage
= ceph_releasepage
,
1117 .direct_IO
= ceph_direct_io
,
1126 * Reuse write_begin here for simplicity.
1128 static int ceph_page_mkwrite(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
1130 struct inode
*inode
= vma
->vm_file
->f_dentry
->d_inode
;
1131 struct page
*page
= vmf
->page
;
1132 struct ceph_mds_client
*mdsc
= &ceph_inode_to_client(inode
)->mdsc
;
1133 loff_t off
= page
->index
<< PAGE_CACHE_SHIFT
;
1137 size
= i_size_read(inode
);
1138 if (off
+ PAGE_CACHE_SIZE
<= size
)
1139 len
= PAGE_CACHE_SIZE
;
1141 len
= size
& ~PAGE_CACHE_MASK
;
1143 dout("page_mkwrite %p %llu~%llu page %p idx %lu\n", inode
,
1144 off
, len
, page
, page
->index
);
1148 ret
= VM_FAULT_NOPAGE
;
1150 (page
->mapping
!= inode
->i_mapping
))
1153 ret
= ceph_update_writeable_page(vma
->vm_file
, off
, len
, page
);
1155 /* success. we'll keep the page locked. */
1156 set_page_dirty(page
);
1157 up_read(&mdsc
->snap_rwsem
);
1158 ret
= VM_FAULT_LOCKED
;
1163 ret
= VM_FAULT_SIGBUS
;
1166 dout("page_mkwrite %p %llu~%llu = %d\n", inode
, off
, len
, ret
);
1167 if (ret
!= VM_FAULT_LOCKED
)
1172 static struct vm_operations_struct ceph_vmops
= {
1173 .fault
= filemap_fault
,
1174 .page_mkwrite
= ceph_page_mkwrite
,
1177 int ceph_mmap(struct file
*file
, struct vm_area_struct
*vma
)
1179 struct address_space
*mapping
= file
->f_mapping
;
1181 if (!mapping
->a_ops
->readpage
)
1183 file_accessed(file
);
1184 vma
->vm_ops
= &ceph_vmops
;
1185 vma
->vm_flags
|= VM_CAN_NONLINEAR
;