1 #include <linux/ceph/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 "mds_client.h"
14 #include <linux/ceph/osd_client.h>
17 * Ceph address space ops.
19 * There are a few funny things going on here.
21 * The page->private field is used to reference a struct
22 * ceph_snap_context for _every_ dirty page. This indicates which
23 * snapshot the page was logically dirtied in, and thus which snap
24 * context needs to be associated with the osd write during writeback.
26 * Similarly, struct ceph_inode_info maintains a set of counters to
27 * count dirty pages on the inode. In the absence of snapshots,
28 * i_wrbuffer_ref == i_wrbuffer_ref_head == the dirty page count.
30 * When a snapshot is taken (that is, when the client receives
31 * notification that a snapshot was taken), each inode with caps and
32 * with dirty pages (dirty pages implies there is a cap) gets a new
33 * ceph_cap_snap in the i_cap_snaps list (which is sorted in ascending
34 * order, new snaps go to the tail). The i_wrbuffer_ref_head count is
35 * moved to capsnap->dirty. (Unless a sync write is currently in
36 * progress. In that case, the capsnap is said to be "pending", new
37 * writes cannot start, and the capsnap isn't "finalized" until the
38 * write completes (or fails) and a final size/mtime for the inode for
39 * that snap can be settled upon.) i_wrbuffer_ref_head is reset to 0.
41 * On writeback, we must submit writes to the osd IN SNAP ORDER. So,
42 * we look for the first capsnap in i_cap_snaps and write out pages in
43 * that snap context _only_. Then we move on to the next capsnap,
44 * eventually reaching the "live" or "head" context (i.e., pages that
45 * are not yet snapped) and are writing the most recently dirtied
48 * Invalidate and so forth must take care to ensure the dirty page
49 * accounting is preserved.
52 #define CONGESTION_ON_THRESH(congestion_kb) (congestion_kb >> (PAGE_SHIFT-10))
53 #define CONGESTION_OFF_THRESH(congestion_kb) \
54 (CONGESTION_ON_THRESH(congestion_kb) - \
55 (CONGESTION_ON_THRESH(congestion_kb) >> 2))
57 static inline struct ceph_snap_context
*page_snap_context(struct page
*page
)
59 if (PagePrivate(page
))
60 return (void *)page
->private;
65 * Dirty a page. Optimistically adjust accounting, on the assumption
66 * that we won't race with invalidate. If we do, readjust.
68 static int ceph_set_page_dirty(struct page
*page
)
70 struct address_space
*mapping
= page
->mapping
;
72 struct ceph_inode_info
*ci
;
74 struct ceph_snap_context
*snapc
;
76 if (unlikely(!mapping
))
77 return !TestSetPageDirty(page
);
79 if (TestSetPageDirty(page
)) {
80 dout("%p set_page_dirty %p idx %lu -- already dirty\n",
81 mapping
->host
, page
, page
->index
);
85 inode
= mapping
->host
;
86 ci
= ceph_inode(inode
);
89 * Note that we're grabbing a snapc ref here without holding
92 snapc
= ceph_get_snap_context(ci
->i_snap_realm
->cached_context
);
95 spin_lock(&ci
->i_ceph_lock
);
96 if (ci
->i_head_snapc
== NULL
)
97 ci
->i_head_snapc
= ceph_get_snap_context(snapc
);
98 ++ci
->i_wrbuffer_ref_head
;
99 if (ci
->i_wrbuffer_ref
== 0)
101 ++ci
->i_wrbuffer_ref
;
102 dout("%p set_page_dirty %p idx %lu head %d/%d -> %d/%d "
103 "snapc %p seq %lld (%d snaps)\n",
104 mapping
->host
, page
, page
->index
,
105 ci
->i_wrbuffer_ref
-1, ci
->i_wrbuffer_ref_head
-1,
106 ci
->i_wrbuffer_ref
, ci
->i_wrbuffer_ref_head
,
107 snapc
, snapc
->seq
, snapc
->num_snaps
);
108 spin_unlock(&ci
->i_ceph_lock
);
110 /* now adjust page */
111 spin_lock_irq(&mapping
->tree_lock
);
112 if (page
->mapping
) { /* Race with truncate? */
113 WARN_ON_ONCE(!PageUptodate(page
));
114 account_page_dirtied(page
, page
->mapping
);
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 int offset
,
150 struct ceph_inode_info
*ci
;
151 struct ceph_snap_context
*snapc
= page_snap_context(page
);
153 BUG_ON(!PageLocked(page
));
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 %u\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(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
= file_inode(filp
);
200 struct ceph_inode_info
*ci
= ceph_inode(inode
);
201 struct ceph_osd_client
*osdc
=
202 &ceph_inode_to_client(inode
)->client
->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 (u64
) page_offset(page
), &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 * Finish an async read(ahead) op.
237 static void finish_read(struct ceph_osd_request
*req
, struct ceph_msg
*msg
)
239 struct inode
*inode
= req
->r_inode
;
240 struct ceph_osd_data
*osd_data
;
241 int rc
= req
->r_result
;
242 int bytes
= le32_to_cpu(msg
->hdr
.data_len
);
246 dout("finish_read %p req %p rc %d bytes %d\n", inode
, req
, rc
, bytes
);
248 /* unlock all pages, zeroing any data we didn't read */
249 osd_data
= osd_req_op_extent_osd_data(req
, 0);
250 BUG_ON(osd_data
->type
!= CEPH_OSD_DATA_TYPE_PAGES
);
251 num_pages
= calc_pages_for((u64
)osd_data
->alignment
,
252 (u64
)osd_data
->length
);
253 for (i
= 0; i
< num_pages
; i
++) {
254 struct page
*page
= osd_data
->pages
[i
];
256 if (bytes
< (int)PAGE_CACHE_SIZE
) {
257 /* zero (remainder of) page */
258 int s
= bytes
< 0 ? 0 : bytes
;
259 zero_user_segment(page
, s
, PAGE_CACHE_SIZE
);
261 dout("finish_read %p uptodate %p idx %lu\n", inode
, page
,
263 flush_dcache_page(page
);
264 SetPageUptodate(page
);
266 page_cache_release(page
);
267 bytes
-= PAGE_CACHE_SIZE
;
269 kfree(osd_data
->pages
);
272 static void ceph_unlock_page_vector(struct page
**pages
, int num_pages
)
276 for (i
= 0; i
< num_pages
; i
++)
277 unlock_page(pages
[i
]);
281 * start an async read(ahead) operation. return nr_pages we submitted
282 * a read for on success, or negative error code.
284 static int start_read(struct inode
*inode
, struct list_head
*page_list
, int max
)
286 struct ceph_osd_client
*osdc
=
287 &ceph_inode_to_client(inode
)->client
->osdc
;
288 struct ceph_inode_info
*ci
= ceph_inode(inode
);
289 struct page
*page
= list_entry(page_list
->prev
, struct page
, lru
);
290 struct ceph_vino vino
;
291 struct ceph_osd_request
*req
;
300 off
= (u64
) page_offset(page
);
303 next_index
= page
->index
;
304 list_for_each_entry_reverse(page
, page_list
, lru
) {
305 if (page
->index
!= next_index
)
309 if (max
&& nr_pages
== max
)
312 len
= nr_pages
<< PAGE_CACHE_SHIFT
;
313 dout("start_read %p nr_pages %d is %lld~%lld\n", inode
, nr_pages
,
315 vino
= ceph_vino(inode
);
316 req
= ceph_osdc_new_request(osdc
, &ci
->i_layout
, vino
, off
, &len
,
318 CEPH_OSD_FLAG_READ
, NULL
,
319 ci
->i_truncate_seq
, ci
->i_truncate_size
,
324 /* build page vector */
325 nr_pages
= calc_pages_for(0, len
);
326 pages
= kmalloc(sizeof(*pages
) * nr_pages
, GFP_NOFS
);
330 for (i
= 0; i
< nr_pages
; ++i
) {
331 page
= list_entry(page_list
->prev
, struct page
, lru
);
332 BUG_ON(PageLocked(page
));
333 list_del(&page
->lru
);
335 dout("start_read %p adding %p idx %lu\n", inode
, page
,
337 if (add_to_page_cache_lru(page
, &inode
->i_data
, page
->index
,
339 page_cache_release(page
);
340 dout("start_read %p add_to_page_cache failed %p\n",
347 osd_req_op_extent_osd_data_pages(req
, 0, pages
, len
, 0, false, false);
348 req
->r_callback
= finish_read
;
349 req
->r_inode
= inode
;
351 ceph_osdc_build_request(req
, off
, NULL
, vino
.snap
, NULL
);
353 dout("start_read %p starting %p %lld~%lld\n", inode
, req
, off
, len
);
354 ret
= ceph_osdc_start_request(osdc
, req
, false);
357 ceph_osdc_put_request(req
);
361 ceph_unlock_page_vector(pages
, nr_pages
);
362 ceph_release_page_vector(pages
, nr_pages
);
364 ceph_osdc_put_request(req
);
370 * Read multiple pages. Leave pages we don't read + unlock in page_list;
371 * the caller (VM) cleans them up.
373 static int ceph_readpages(struct file
*file
, struct address_space
*mapping
,
374 struct list_head
*page_list
, unsigned nr_pages
)
376 struct inode
*inode
= file_inode(file
);
377 struct ceph_fs_client
*fsc
= ceph_inode_to_client(inode
);
381 if (fsc
->mount_options
->rsize
>= PAGE_CACHE_SIZE
)
382 max
= (fsc
->mount_options
->rsize
+ PAGE_CACHE_SIZE
- 1)
385 dout("readpages %p file %p nr_pages %d max %d\n", inode
,
388 while (!list_empty(page_list
)) {
389 rc
= start_read(inode
, page_list
, max
);
395 dout("readpages %p file %p ret %d\n", inode
, file
, rc
);
400 * Get ref for the oldest snapc for an inode with dirty data... that is, the
401 * only snap context we are allowed to write back.
403 static struct ceph_snap_context
*get_oldest_context(struct inode
*inode
,
406 struct ceph_inode_info
*ci
= ceph_inode(inode
);
407 struct ceph_snap_context
*snapc
= NULL
;
408 struct ceph_cap_snap
*capsnap
= NULL
;
410 spin_lock(&ci
->i_ceph_lock
);
411 list_for_each_entry(capsnap
, &ci
->i_cap_snaps
, ci_item
) {
412 dout(" cap_snap %p snapc %p has %d dirty pages\n", capsnap
,
413 capsnap
->context
, capsnap
->dirty_pages
);
414 if (capsnap
->dirty_pages
) {
415 snapc
= ceph_get_snap_context(capsnap
->context
);
417 *snap_size
= capsnap
->size
;
421 if (!snapc
&& ci
->i_wrbuffer_ref_head
) {
422 snapc
= ceph_get_snap_context(ci
->i_head_snapc
);
423 dout(" head snapc %p has %d dirty pages\n",
424 snapc
, ci
->i_wrbuffer_ref_head
);
426 spin_unlock(&ci
->i_ceph_lock
);
431 * Write a single page, but leave the page locked.
433 * If we get a write error, set the page error bit, but still adjust the
434 * dirty page accounting (i.e., page is no longer dirty).
436 static int writepage_nounlock(struct page
*page
, struct writeback_control
*wbc
)
439 struct ceph_inode_info
*ci
;
440 struct ceph_fs_client
*fsc
;
441 struct ceph_osd_client
*osdc
;
442 loff_t page_off
= page_offset(page
);
443 int len
= PAGE_CACHE_SIZE
;
446 struct ceph_snap_context
*snapc
, *oldest
;
450 dout("writepage %p idx %lu\n", page
, page
->index
);
452 if (!page
->mapping
|| !page
->mapping
->host
) {
453 dout("writepage %p - no mapping\n", page
);
456 inode
= page
->mapping
->host
;
457 ci
= ceph_inode(inode
);
458 fsc
= ceph_inode_to_client(inode
);
459 osdc
= &fsc
->client
->osdc
;
461 /* verify this is a writeable snap context */
462 snapc
= page_snap_context(page
);
464 dout("writepage %p page %p not dirty?\n", inode
, page
);
467 oldest
= get_oldest_context(inode
, &snap_size
);
468 if (snapc
->seq
> oldest
->seq
) {
469 dout("writepage %p page %p snapc %p not writeable - noop\n",
471 /* we should only noop if called by kswapd */
472 WARN_ON((current
->flags
& PF_MEMALLOC
) == 0);
473 ceph_put_snap_context(oldest
);
476 ceph_put_snap_context(oldest
);
478 /* is this a partial page at end of file? */
482 i_size
= i_size_read(inode
);
483 if (i_size
< page_off
+ len
)
484 len
= i_size
- page_off
;
486 dout("writepage %p page %p index %lu on %llu~%u snapc %p\n",
487 inode
, page
, page
->index
, page_off
, len
, snapc
);
489 writeback_stat
= atomic_long_inc_return(&fsc
->writeback_count
);
491 CONGESTION_ON_THRESH(fsc
->mount_options
->congestion_kb
))
492 set_bdi_congested(&fsc
->backing_dev_info
, BLK_RW_ASYNC
);
494 set_page_writeback(page
);
495 err
= ceph_osdc_writepages(osdc
, ceph_vino(inode
),
496 &ci
->i_layout
, snapc
,
498 ci
->i_truncate_seq
, ci
->i_truncate_size
,
499 &inode
->i_mtime
, &page
, 1);
501 dout("writepage setting page/mapping error %d %p\n", err
, page
);
503 mapping_set_error(&inode
->i_data
, err
);
505 wbc
->pages_skipped
++;
507 dout("writepage cleaned page %p\n", page
);
508 err
= 0; /* vfs expects us to return 0 */
511 ClearPagePrivate(page
);
512 end_page_writeback(page
);
513 ceph_put_wrbuffer_cap_refs(ci
, 1, snapc
);
514 ceph_put_snap_context(snapc
); /* page's reference */
519 static int ceph_writepage(struct page
*page
, struct writeback_control
*wbc
)
522 struct inode
*inode
= page
->mapping
->host
;
525 err
= writepage_nounlock(page
, wbc
);
533 * lame release_pages helper. release_pages() isn't exported to
536 static void ceph_release_pages(struct page
**pages
, int num
)
541 pagevec_init(&pvec
, 0);
542 for (i
= 0; i
< num
; i
++) {
543 if (pagevec_add(&pvec
, pages
[i
]) == 0)
544 pagevec_release(&pvec
);
546 pagevec_release(&pvec
);
551 * async writeback completion handler.
553 * If we get an error, set the mapping error bit, but not the individual
556 static void writepages_finish(struct ceph_osd_request
*req
,
557 struct ceph_msg
*msg
)
559 struct inode
*inode
= req
->r_inode
;
560 struct ceph_inode_info
*ci
= ceph_inode(inode
);
561 struct ceph_osd_data
*osd_data
;
566 struct ceph_snap_context
*snapc
= req
->r_snapc
;
567 struct address_space
*mapping
= inode
->i_mapping
;
568 int rc
= req
->r_result
;
569 u64 bytes
= req
->r_ops
[0].extent
.length
;
570 struct ceph_fs_client
*fsc
= ceph_inode_to_client(inode
);
572 unsigned issued
= ceph_caps_issued(ci
);
574 osd_data
= osd_req_op_extent_osd_data(req
, 0);
575 BUG_ON(osd_data
->type
!= CEPH_OSD_DATA_TYPE_PAGES
);
576 num_pages
= calc_pages_for((u64
)osd_data
->alignment
,
577 (u64
)osd_data
->length
);
580 * Assume we wrote the pages we originally sent. The
581 * osd might reply with fewer pages if our writeback
582 * raced with a truncation and was adjusted at the osd,
583 * so don't believe the reply.
588 mapping_set_error(mapping
, rc
);
590 dout("writepages_finish %p rc %d bytes %llu wrote %d (pages)\n",
591 inode
, rc
, bytes
, wrote
);
593 /* clean all pages */
594 for (i
= 0; i
< num_pages
; i
++) {
595 page
= osd_data
->pages
[i
];
597 WARN_ON(!PageUptodate(page
));
600 atomic_long_dec_return(&fsc
->writeback_count
);
602 CONGESTION_OFF_THRESH(fsc
->mount_options
->congestion_kb
))
603 clear_bdi_congested(&fsc
->backing_dev_info
,
606 ceph_put_snap_context(page_snap_context(page
));
608 ClearPagePrivate(page
);
609 dout("unlocking %d %p\n", i
, page
);
610 end_page_writeback(page
);
613 * We lost the cache cap, need to truncate the page before
614 * it is unlocked, otherwise we'd truncate it later in the
615 * page truncation thread, possibly losing some data that
618 if ((issued
& (CEPH_CAP_FILE_CACHE
|CEPH_CAP_FILE_LAZYIO
)) == 0)
619 generic_error_remove_page(inode
->i_mapping
, page
);
623 dout("%p wrote+cleaned %d pages\n", inode
, wrote
);
624 ceph_put_wrbuffer_cap_refs(ci
, num_pages
, snapc
);
626 ceph_release_pages(osd_data
->pages
, num_pages
);
627 if (osd_data
->pages_from_pool
)
628 mempool_free(osd_data
->pages
,
629 ceph_sb_to_client(inode
->i_sb
)->wb_pagevec_pool
);
631 kfree(osd_data
->pages
);
632 ceph_osdc_put_request(req
);
635 static struct ceph_osd_request
*
636 ceph_writepages_osd_request(struct inode
*inode
, u64 offset
, u64
*len
,
637 struct ceph_snap_context
*snapc
, int num_ops
)
639 struct ceph_fs_client
*fsc
;
640 struct ceph_inode_info
*ci
;
641 struct ceph_vino vino
;
643 fsc
= ceph_inode_to_client(inode
);
644 ci
= ceph_inode(inode
);
645 vino
= ceph_vino(inode
);
646 /* BUG_ON(vino.snap != CEPH_NOSNAP); */
648 return ceph_osdc_new_request(&fsc
->client
->osdc
, &ci
->i_layout
,
649 vino
, offset
, len
, num_ops
, CEPH_OSD_OP_WRITE
,
650 CEPH_OSD_FLAG_WRITE
|CEPH_OSD_FLAG_ONDISK
,
651 snapc
, ci
->i_truncate_seq
, ci
->i_truncate_size
, true);
655 * initiate async writeback
657 static int ceph_writepages_start(struct address_space
*mapping
,
658 struct writeback_control
*wbc
)
660 struct inode
*inode
= mapping
->host
;
661 struct ceph_inode_info
*ci
= ceph_inode(inode
);
662 struct ceph_fs_client
*fsc
;
663 pgoff_t index
, start
, end
;
666 pgoff_t max_pages
= 0, max_pages_ever
= 0;
667 struct ceph_snap_context
*snapc
= NULL
, *last_snapc
= NULL
, *pgsnapc
;
671 unsigned wsize
= 1 << inode
->i_blkbits
;
672 struct ceph_osd_request
*req
= NULL
;
677 * Include a 'sync' in the OSD request if this is a data
678 * integrity write (e.g., O_SYNC write or fsync()), or if our
679 * cap is being revoked.
681 do_sync
= wbc
->sync_mode
== WB_SYNC_ALL
;
682 if (ceph_caps_revoking(ci
, CEPH_CAP_FILE_BUFFER
))
684 dout("writepages_start %p dosync=%d (mode=%s)\n",
686 wbc
->sync_mode
== WB_SYNC_NONE
? "NONE" :
687 (wbc
->sync_mode
== WB_SYNC_ALL
? "ALL" : "HOLD"));
689 fsc
= ceph_inode_to_client(inode
);
690 if (fsc
->mount_state
== CEPH_MOUNT_SHUTDOWN
) {
691 pr_warning("writepage_start %p on forced umount\n", inode
);
692 return -EIO
; /* we're in a forced umount, don't write! */
694 if (fsc
->mount_options
->wsize
&& fsc
->mount_options
->wsize
< wsize
)
695 wsize
= fsc
->mount_options
->wsize
;
696 if (wsize
< PAGE_CACHE_SIZE
)
697 wsize
= PAGE_CACHE_SIZE
;
698 max_pages_ever
= wsize
>> PAGE_CACHE_SHIFT
;
700 pagevec_init(&pvec
, 0);
702 /* where to start/end? */
703 if (wbc
->range_cyclic
) {
704 start
= mapping
->writeback_index
; /* Start from prev offset */
706 dout(" cyclic, start at %lu\n", start
);
708 start
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
709 end
= wbc
->range_end
>> PAGE_CACHE_SHIFT
;
710 if (wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
)
713 dout(" not cyclic, %lu to %lu\n", start
, end
);
718 /* find oldest snap context with dirty data */
719 ceph_put_snap_context(snapc
);
721 snapc
= get_oldest_context(inode
, &snap_size
);
723 /* hmm, why does writepages get called when there
725 dout(" no snap context with dirty data?\n");
729 snap_size
= i_size_read(inode
);
730 dout(" oldest snapc is %p seq %lld (%d snaps)\n",
731 snapc
, snapc
->seq
, snapc
->num_snaps
);
732 if (last_snapc
&& snapc
!= last_snapc
) {
733 /* if we switched to a newer snapc, restart our scan at the
734 * start of the original file range. */
735 dout(" snapc differs from last pass, restarting at %lu\n",
741 while (!done
&& index
<= end
) {
742 int num_ops
= do_sync
? 2 : 1;
743 struct ceph_vino vino
;
747 int pvec_pages
, locked_pages
;
748 struct page
**pages
= NULL
;
749 mempool_t
*pool
= NULL
; /* Becomes non-null if mempool used */
757 max_pages
= max_pages_ever
;
761 want
= min(end
- index
,
762 min((pgoff_t
)PAGEVEC_SIZE
,
763 max_pages
- (pgoff_t
)locked_pages
) - 1)
765 pvec_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
,
768 dout("pagevec_lookup_tag got %d\n", pvec_pages
);
769 if (!pvec_pages
&& !locked_pages
)
771 for (i
= 0; i
< pvec_pages
&& locked_pages
< max_pages
; i
++) {
772 page
= pvec
.pages
[i
];
773 dout("? %p idx %lu\n", page
, page
->index
);
774 if (locked_pages
== 0)
775 lock_page(page
); /* first page */
776 else if (!trylock_page(page
))
779 /* only dirty pages, or our accounting breaks */
780 if (unlikely(!PageDirty(page
)) ||
781 unlikely(page
->mapping
!= mapping
)) {
782 dout("!dirty or !mapping %p\n", page
);
786 if (!wbc
->range_cyclic
&& page
->index
> end
) {
787 dout("end of range %p\n", page
);
792 if (next
&& (page
->index
!= next
)) {
793 dout("not consecutive %p\n", page
);
797 if (wbc
->sync_mode
!= WB_SYNC_NONE
) {
798 dout("waiting on writeback %p\n", page
);
799 wait_on_page_writeback(page
);
801 if (page_offset(page
) >= snap_size
) {
802 dout("%p page eof %llu\n", page
, snap_size
);
807 if (PageWriteback(page
)) {
808 dout("%p under writeback\n", page
);
813 /* only if matching snap context */
814 pgsnapc
= page_snap_context(page
);
815 if (pgsnapc
->seq
> snapc
->seq
) {
816 dout("page snapc %p %lld > oldest %p %lld\n",
817 pgsnapc
, pgsnapc
->seq
, snapc
, snapc
->seq
);
820 continue; /* keep looking for snap */
824 if (!clear_page_dirty_for_io(page
)) {
825 dout("%p !clear_page_dirty_for_io\n", page
);
831 * We have something to write. If this is
832 * the first locked page this time through,
833 * allocate an osd request and a page array
836 if (locked_pages
== 0) {
841 /* prepare async write request */
842 offset
= (u64
)page_offset(page
);
844 req
= ceph_writepages_osd_request(inode
,
854 req
->r_callback
= writepages_finish
;
855 req
->r_inode
= inode
;
857 max_pages
= calc_pages_for(0, (u64
)len
);
858 size
= max_pages
* sizeof (*pages
);
859 pages
= kmalloc(size
, GFP_NOFS
);
861 pool
= fsc
->wb_pagevec_pool
;
862 pages
= mempool_alloc(pool
, GFP_NOFS
);
867 /* note position of first page in pvec */
870 dout("%p will write page %p idx %lu\n",
871 inode
, page
, page
->index
);
874 atomic_long_inc_return(&fsc
->writeback_count
);
875 if (writeback_stat
> CONGESTION_ON_THRESH(
876 fsc
->mount_options
->congestion_kb
)) {
877 set_bdi_congested(&fsc
->backing_dev_info
,
881 set_page_writeback(page
);
882 pages
[locked_pages
] = page
;
884 next
= page
->index
+ 1;
887 /* did we get anything? */
889 goto release_pvec_pages
;
892 BUG_ON(!locked_pages
|| first
< 0);
894 if (pvec_pages
&& i
== pvec_pages
&&
895 locked_pages
< max_pages
) {
896 dout("reached end pvec, trying for more\n");
897 pagevec_reinit(&pvec
);
901 /* shift unused pages over in the pvec... we
902 * will need to release them below. */
903 for (j
= i
; j
< pvec_pages
; j
++) {
904 dout(" pvec leftover page %p\n",
906 pvec
.pages
[j
-i
+first
] = pvec
.pages
[j
];
911 /* Format the osd request message and submit the write */
913 offset
= page_offset(pages
[0]);
914 len
= min(snap_size
- offset
,
915 (u64
)locked_pages
<< PAGE_CACHE_SHIFT
);
916 dout("writepages got %d pages at %llu~%llu\n",
917 locked_pages
, offset
, len
);
919 osd_req_op_extent_osd_data_pages(req
, 0, pages
, len
, 0,
922 pages
= NULL
; /* request message now owns the pages array */
925 /* Update the write op length in case we changed it */
927 osd_req_op_extent_update(req
, 0, len
);
929 vino
= ceph_vino(inode
);
930 ceph_osdc_build_request(req
, offset
, snapc
, vino
.snap
,
933 rc
= ceph_osdc_start_request(&fsc
->client
->osdc
, req
, true);
939 wbc
->nr_to_write
-= locked_pages
;
940 if (wbc
->nr_to_write
<= 0)
944 dout("pagevec_release on %d pages (%p)\n", (int)pvec
.nr
,
945 pvec
.nr
? pvec
.pages
[0] : NULL
);
946 pagevec_release(&pvec
);
948 if (locked_pages
&& !done
)
952 if (should_loop
&& !done
) {
953 /* more to do; loop back to beginning of file */
954 dout("writepages looping back to beginning of file\n");
960 if (wbc
->range_cyclic
|| (range_whole
&& wbc
->nr_to_write
> 0))
961 mapping
->writeback_index
= index
;
965 ceph_osdc_put_request(req
);
966 ceph_put_snap_context(snapc
);
967 dout("writepages done, rc = %d\n", rc
);
974 * See if a given @snapc is either writeable, or already written.
976 static int context_is_writeable_or_written(struct inode
*inode
,
977 struct ceph_snap_context
*snapc
)
979 struct ceph_snap_context
*oldest
= get_oldest_context(inode
, NULL
);
980 int ret
= !oldest
|| snapc
->seq
<= oldest
->seq
;
982 ceph_put_snap_context(oldest
);
987 * We are only allowed to write into/dirty the page if the page is
988 * clean, or already dirty within the same snap context.
990 * called with page locked.
991 * return success with page locked,
992 * or any failure (incl -EAGAIN) with page unlocked.
994 static int ceph_update_writeable_page(struct file
*file
,
995 loff_t pos
, unsigned len
,
998 struct inode
*inode
= file_inode(file
);
999 struct ceph_inode_info
*ci
= ceph_inode(inode
);
1000 struct ceph_mds_client
*mdsc
= ceph_inode_to_client(inode
)->mdsc
;
1001 loff_t page_off
= pos
& PAGE_CACHE_MASK
;
1002 int pos_in_page
= pos
& ~PAGE_CACHE_MASK
;
1003 int end_in_page
= pos_in_page
+ len
;
1006 struct ceph_snap_context
*snapc
, *oldest
;
1009 /* writepages currently holds page lock, but if we change that later, */
1010 wait_on_page_writeback(page
);
1012 /* check snap context */
1013 BUG_ON(!ci
->i_snap_realm
);
1014 down_read(&mdsc
->snap_rwsem
);
1015 BUG_ON(!ci
->i_snap_realm
->cached_context
);
1016 snapc
= page_snap_context(page
);
1017 if (snapc
&& snapc
!= ci
->i_head_snapc
) {
1019 * this page is already dirty in another (older) snap
1020 * context! is it writeable now?
1022 oldest
= get_oldest_context(inode
, NULL
);
1023 up_read(&mdsc
->snap_rwsem
);
1025 if (snapc
->seq
> oldest
->seq
) {
1026 ceph_put_snap_context(oldest
);
1027 dout(" page %p snapc %p not current or oldest\n",
1030 * queue for writeback, and wait for snapc to
1031 * be writeable or written
1033 snapc
= ceph_get_snap_context(snapc
);
1035 ceph_queue_writeback(inode
);
1036 r
= wait_event_interruptible(ci
->i_cap_wq
,
1037 context_is_writeable_or_written(inode
, snapc
));
1038 ceph_put_snap_context(snapc
);
1039 if (r
== -ERESTARTSYS
)
1043 ceph_put_snap_context(oldest
);
1045 /* yay, writeable, do it now (without dropping page lock) */
1046 dout(" page %p snapc %p not current, but oldest\n",
1048 if (!clear_page_dirty_for_io(page
))
1050 r
= writepage_nounlock(page
, NULL
);
1056 if (PageUptodate(page
)) {
1057 dout(" page %p already uptodate\n", page
);
1062 if (pos_in_page
== 0 && len
== PAGE_CACHE_SIZE
)
1065 /* past end of file? */
1066 i_size
= inode
->i_size
; /* caller holds i_mutex */
1068 if (i_size
+ len
> inode
->i_sb
->s_maxbytes
) {
1069 /* file is too big */
1074 if (page_off
>= i_size
||
1075 (pos_in_page
== 0 && (pos
+len
) >= i_size
&&
1076 end_in_page
- pos_in_page
!= PAGE_CACHE_SIZE
)) {
1077 dout(" zeroing %p 0 - %d and %d - %d\n",
1078 page
, pos_in_page
, end_in_page
, (int)PAGE_CACHE_SIZE
);
1079 zero_user_segments(page
,
1081 end_in_page
, PAGE_CACHE_SIZE
);
1085 /* we need to read it. */
1086 up_read(&mdsc
->snap_rwsem
);
1087 r
= readpage_nounlock(file
, page
);
1093 up_read(&mdsc
->snap_rwsem
);
1100 * We are only allowed to write into/dirty the page if the page is
1101 * clean, or already dirty within the same snap context.
1103 static int ceph_write_begin(struct file
*file
, struct address_space
*mapping
,
1104 loff_t pos
, unsigned len
, unsigned flags
,
1105 struct page
**pagep
, void **fsdata
)
1107 struct inode
*inode
= file_inode(file
);
1109 pgoff_t index
= pos
>> PAGE_CACHE_SHIFT
;
1114 page
= grab_cache_page_write_begin(mapping
, index
, 0);
1119 dout("write_begin file %p inode %p page %p %d~%d\n", file
,
1120 inode
, page
, (int)pos
, (int)len
);
1122 r
= ceph_update_writeable_page(file
, pos
, len
, page
);
1123 } while (r
== -EAGAIN
);
1129 * we don't do anything in here that simple_write_end doesn't do
1130 * except adjust dirty page accounting and drop read lock on
1133 static int ceph_write_end(struct file
*file
, struct address_space
*mapping
,
1134 loff_t pos
, unsigned len
, unsigned copied
,
1135 struct page
*page
, void *fsdata
)
1137 struct inode
*inode
= file_inode(file
);
1138 struct ceph_fs_client
*fsc
= ceph_inode_to_client(inode
);
1139 struct ceph_mds_client
*mdsc
= fsc
->mdsc
;
1140 unsigned from
= pos
& (PAGE_CACHE_SIZE
- 1);
1143 dout("write_end file %p inode %p page %p %d~%d (%d)\n", file
,
1144 inode
, page
, (int)pos
, (int)copied
, (int)len
);
1146 /* zero the stale part of the page if we did a short copy */
1148 zero_user_segment(page
, from
+copied
, len
);
1150 /* did file size increase? */
1151 /* (no need for i_size_read(); we caller holds i_mutex */
1152 if (pos
+copied
> inode
->i_size
)
1153 check_cap
= ceph_inode_set_size(inode
, pos
+copied
);
1155 if (!PageUptodate(page
))
1156 SetPageUptodate(page
);
1158 set_page_dirty(page
);
1161 up_read(&mdsc
->snap_rwsem
);
1162 page_cache_release(page
);
1165 ceph_check_caps(ceph_inode(inode
), CHECK_CAPS_AUTHONLY
, NULL
);
1171 * we set .direct_IO to indicate direct io is supported, but since we
1172 * intercept O_DIRECT reads and writes early, this function should
1175 static ssize_t
ceph_direct_io(int rw
, struct kiocb
*iocb
,
1176 const struct iovec
*iov
,
1177 loff_t pos
, unsigned long nr_segs
)
1183 const struct address_space_operations ceph_aops
= {
1184 .readpage
= ceph_readpage
,
1185 .readpages
= ceph_readpages
,
1186 .writepage
= ceph_writepage
,
1187 .writepages
= ceph_writepages_start
,
1188 .write_begin
= ceph_write_begin
,
1189 .write_end
= ceph_write_end
,
1190 .set_page_dirty
= ceph_set_page_dirty
,
1191 .invalidatepage
= ceph_invalidatepage
,
1192 .releasepage
= ceph_releasepage
,
1193 .direct_IO
= ceph_direct_io
,
1202 * Reuse write_begin here for simplicity.
1204 static int ceph_page_mkwrite(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
1206 struct inode
*inode
= file_inode(vma
->vm_file
);
1207 struct page
*page
= vmf
->page
;
1208 struct ceph_mds_client
*mdsc
= ceph_inode_to_client(inode
)->mdsc
;
1209 loff_t off
= page_offset(page
);
1213 /* Update time before taking page lock */
1214 file_update_time(vma
->vm_file
);
1216 size
= i_size_read(inode
);
1217 if (off
+ PAGE_CACHE_SIZE
<= size
)
1218 len
= PAGE_CACHE_SIZE
;
1220 len
= size
& ~PAGE_CACHE_MASK
;
1222 dout("page_mkwrite %p %llu~%llu page %p idx %lu\n", inode
,
1223 off
, len
, page
, page
->index
);
1227 ret
= VM_FAULT_NOPAGE
;
1229 (page
->mapping
!= inode
->i_mapping
))
1232 ret
= ceph_update_writeable_page(vma
->vm_file
, off
, len
, page
);
1234 /* success. we'll keep the page locked. */
1235 set_page_dirty(page
);
1236 up_read(&mdsc
->snap_rwsem
);
1237 ret
= VM_FAULT_LOCKED
;
1242 ret
= VM_FAULT_SIGBUS
;
1245 dout("page_mkwrite %p %llu~%llu = %d\n", inode
, off
, len
, ret
);
1246 if (ret
!= VM_FAULT_LOCKED
)
1251 static struct vm_operations_struct ceph_vmops
= {
1252 .fault
= filemap_fault
,
1253 .page_mkwrite
= ceph_page_mkwrite
,
1254 .remap_pages
= generic_file_remap_pages
,
1257 int ceph_mmap(struct file
*file
, struct vm_area_struct
*vma
)
1259 struct address_space
*mapping
= file
->f_mapping
;
1261 if (!mapping
->a_ops
->readpage
)
1263 file_accessed(file
);
1264 vma
->vm_ops
= &ceph_vmops
;