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 inode
= page
->mapping
->host
;
156 * We can get non-dirty pages here due to races between
157 * set_page_dirty and truncate_complete_page; just spit out a
158 * warning, in case we end up with accounting problems later.
160 if (!PageDirty(page
))
161 pr_err("%p invalidatepage %p page not dirty\n", inode
, page
);
163 if (offset
== 0 && length
== PAGE_CACHE_SIZE
)
164 ClearPageChecked(page
);
166 ci
= ceph_inode(inode
);
167 if (offset
== 0 && length
== PAGE_CACHE_SIZE
) {
168 dout("%p invalidatepage %p idx %lu full dirty page\n",
169 inode
, page
, page
->index
);
170 ceph_put_wrbuffer_cap_refs(ci
, 1, snapc
);
171 ceph_put_snap_context(snapc
);
173 ClearPagePrivate(page
);
175 dout("%p invalidatepage %p idx %lu partial dirty page %u(%u)\n",
176 inode
, page
, page
->index
, offset
, length
);
180 /* just a sanity check */
181 static int ceph_releasepage(struct page
*page
, gfp_t g
)
183 struct inode
*inode
= page
->mapping
? page
->mapping
->host
: NULL
;
184 dout("%p releasepage %p idx %lu\n", inode
, page
, page
->index
);
185 WARN_ON(PageDirty(page
));
186 WARN_ON(PagePrivate(page
));
191 * read a single page, without unlocking it.
193 static int readpage_nounlock(struct file
*filp
, struct page
*page
)
195 struct inode
*inode
= file_inode(filp
);
196 struct ceph_inode_info
*ci
= ceph_inode(inode
);
197 struct ceph_osd_client
*osdc
=
198 &ceph_inode_to_client(inode
)->client
->osdc
;
200 u64 len
= PAGE_CACHE_SIZE
;
202 dout("readpage inode %p file %p page %p index %lu\n",
203 inode
, filp
, page
, page
->index
);
204 err
= ceph_osdc_readpages(osdc
, ceph_vino(inode
), &ci
->i_layout
,
205 (u64
) page_offset(page
), &len
,
206 ci
->i_truncate_seq
, ci
->i_truncate_size
,
213 } else if (err
< PAGE_CACHE_SIZE
) {
214 /* zero fill remainder of page */
215 zero_user_segment(page
, err
, PAGE_CACHE_SIZE
);
217 SetPageUptodate(page
);
220 return err
< 0 ? err
: 0;
223 static int ceph_readpage(struct file
*filp
, struct page
*page
)
225 int r
= readpage_nounlock(filp
, page
);
231 * Finish an async read(ahead) op.
233 static void finish_read(struct ceph_osd_request
*req
, struct ceph_msg
*msg
)
235 struct inode
*inode
= req
->r_inode
;
236 struct ceph_osd_data
*osd_data
;
237 int rc
= req
->r_result
;
238 int bytes
= le32_to_cpu(msg
->hdr
.data_len
);
242 dout("finish_read %p req %p rc %d bytes %d\n", inode
, req
, rc
, bytes
);
244 /* unlock all pages, zeroing any data we didn't read */
245 osd_data
= osd_req_op_extent_osd_data(req
, 0);
246 BUG_ON(osd_data
->type
!= CEPH_OSD_DATA_TYPE_PAGES
);
247 num_pages
= calc_pages_for((u64
)osd_data
->alignment
,
248 (u64
)osd_data
->length
);
249 for (i
= 0; i
< num_pages
; i
++) {
250 struct page
*page
= osd_data
->pages
[i
];
252 if (bytes
< (int)PAGE_CACHE_SIZE
) {
253 /* zero (remainder of) page */
254 int s
= bytes
< 0 ? 0 : bytes
;
255 zero_user_segment(page
, s
, PAGE_CACHE_SIZE
);
257 dout("finish_read %p uptodate %p idx %lu\n", inode
, page
,
259 flush_dcache_page(page
);
260 SetPageUptodate(page
);
262 page_cache_release(page
);
263 bytes
-= PAGE_CACHE_SIZE
;
265 kfree(osd_data
->pages
);
268 static void ceph_unlock_page_vector(struct page
**pages
, int num_pages
)
272 for (i
= 0; i
< num_pages
; i
++)
273 unlock_page(pages
[i
]);
277 * start an async read(ahead) operation. return nr_pages we submitted
278 * a read for on success, or negative error code.
280 static int start_read(struct inode
*inode
, struct list_head
*page_list
, int max
)
282 struct ceph_osd_client
*osdc
=
283 &ceph_inode_to_client(inode
)->client
->osdc
;
284 struct ceph_inode_info
*ci
= ceph_inode(inode
);
285 struct page
*page
= list_entry(page_list
->prev
, struct page
, lru
);
286 struct ceph_vino vino
;
287 struct ceph_osd_request
*req
;
296 off
= (u64
) page_offset(page
);
299 next_index
= page
->index
;
300 list_for_each_entry_reverse(page
, page_list
, lru
) {
301 if (page
->index
!= next_index
)
305 if (max
&& nr_pages
== max
)
308 len
= nr_pages
<< PAGE_CACHE_SHIFT
;
309 dout("start_read %p nr_pages %d is %lld~%lld\n", inode
, nr_pages
,
311 vino
= ceph_vino(inode
);
312 req
= ceph_osdc_new_request(osdc
, &ci
->i_layout
, vino
, off
, &len
,
314 CEPH_OSD_FLAG_READ
, NULL
,
315 ci
->i_truncate_seq
, ci
->i_truncate_size
,
320 /* build page vector */
321 nr_pages
= calc_pages_for(0, len
);
322 pages
= kmalloc(sizeof(*pages
) * nr_pages
, GFP_NOFS
);
326 for (i
= 0; i
< nr_pages
; ++i
) {
327 page
= list_entry(page_list
->prev
, struct page
, lru
);
328 BUG_ON(PageLocked(page
));
329 list_del(&page
->lru
);
331 dout("start_read %p adding %p idx %lu\n", inode
, page
,
333 if (add_to_page_cache_lru(page
, &inode
->i_data
, page
->index
,
335 page_cache_release(page
);
336 dout("start_read %p add_to_page_cache failed %p\n",
343 osd_req_op_extent_osd_data_pages(req
, 0, pages
, len
, 0, false, false);
344 req
->r_callback
= finish_read
;
345 req
->r_inode
= inode
;
347 ceph_osdc_build_request(req
, off
, NULL
, vino
.snap
, NULL
);
349 dout("start_read %p starting %p %lld~%lld\n", inode
, req
, off
, len
);
350 ret
= ceph_osdc_start_request(osdc
, req
, false);
353 ceph_osdc_put_request(req
);
357 ceph_unlock_page_vector(pages
, nr_pages
);
358 ceph_release_page_vector(pages
, nr_pages
);
360 ceph_osdc_put_request(req
);
366 * Read multiple pages. Leave pages we don't read + unlock in page_list;
367 * the caller (VM) cleans them up.
369 static int ceph_readpages(struct file
*file
, struct address_space
*mapping
,
370 struct list_head
*page_list
, unsigned nr_pages
)
372 struct inode
*inode
= file_inode(file
);
373 struct ceph_fs_client
*fsc
= ceph_inode_to_client(inode
);
377 if (fsc
->mount_options
->rsize
>= PAGE_CACHE_SIZE
)
378 max
= (fsc
->mount_options
->rsize
+ PAGE_CACHE_SIZE
- 1)
381 dout("readpages %p file %p nr_pages %d max %d\n", inode
,
384 while (!list_empty(page_list
)) {
385 rc
= start_read(inode
, page_list
, max
);
391 dout("readpages %p file %p ret %d\n", inode
, file
, rc
);
396 * Get ref for the oldest snapc for an inode with dirty data... that is, the
397 * only snap context we are allowed to write back.
399 static struct ceph_snap_context
*get_oldest_context(struct inode
*inode
,
402 struct ceph_inode_info
*ci
= ceph_inode(inode
);
403 struct ceph_snap_context
*snapc
= NULL
;
404 struct ceph_cap_snap
*capsnap
= NULL
;
406 spin_lock(&ci
->i_ceph_lock
);
407 list_for_each_entry(capsnap
, &ci
->i_cap_snaps
, ci_item
) {
408 dout(" cap_snap %p snapc %p has %d dirty pages\n", capsnap
,
409 capsnap
->context
, capsnap
->dirty_pages
);
410 if (capsnap
->dirty_pages
) {
411 snapc
= ceph_get_snap_context(capsnap
->context
);
413 *snap_size
= capsnap
->size
;
417 if (!snapc
&& ci
->i_wrbuffer_ref_head
) {
418 snapc
= ceph_get_snap_context(ci
->i_head_snapc
);
419 dout(" head snapc %p has %d dirty pages\n",
420 snapc
, ci
->i_wrbuffer_ref_head
);
422 spin_unlock(&ci
->i_ceph_lock
);
427 * Write a single page, but leave the page locked.
429 * If we get a write error, set the page error bit, but still adjust the
430 * dirty page accounting (i.e., page is no longer dirty).
432 static int writepage_nounlock(struct page
*page
, struct writeback_control
*wbc
)
435 struct ceph_inode_info
*ci
;
436 struct ceph_fs_client
*fsc
;
437 struct ceph_osd_client
*osdc
;
438 struct ceph_snap_context
*snapc
, *oldest
;
439 loff_t page_off
= page_offset(page
);
441 u64 truncate_size
, snap_size
= 0;
443 int err
= 0, len
= PAGE_CACHE_SIZE
;
445 dout("writepage %p idx %lu\n", page
, page
->index
);
447 if (!page
->mapping
|| !page
->mapping
->host
) {
448 dout("writepage %p - no mapping\n", page
);
451 inode
= page
->mapping
->host
;
452 ci
= ceph_inode(inode
);
453 fsc
= ceph_inode_to_client(inode
);
454 osdc
= &fsc
->client
->osdc
;
456 /* verify this is a writeable snap context */
457 snapc
= page_snap_context(page
);
459 dout("writepage %p page %p not dirty?\n", inode
, page
);
462 oldest
= get_oldest_context(inode
, &snap_size
);
463 if (snapc
->seq
> oldest
->seq
) {
464 dout("writepage %p page %p snapc %p not writeable - noop\n",
466 /* we should only noop if called by kswapd */
467 WARN_ON((current
->flags
& PF_MEMALLOC
) == 0);
468 ceph_put_snap_context(oldest
);
471 ceph_put_snap_context(oldest
);
473 spin_lock(&ci
->i_ceph_lock
);
474 truncate_seq
= ci
->i_truncate_seq
;
475 truncate_size
= ci
->i_truncate_size
;
477 snap_size
= i_size_read(inode
);
478 spin_unlock(&ci
->i_ceph_lock
);
480 /* is this a partial page at end of file? */
481 if (page_off
>= snap_size
) {
482 dout("%p page eof %llu\n", page
, snap_size
);
485 if (snap_size
< page_off
+ len
)
486 len
= snap_size
- page_off
;
488 dout("writepage %p page %p index %lu on %llu~%u snapc %p\n",
489 inode
, page
, page
->index
, page_off
, len
, snapc
);
491 writeback_stat
= atomic_long_inc_return(&fsc
->writeback_count
);
493 CONGESTION_ON_THRESH(fsc
->mount_options
->congestion_kb
))
494 set_bdi_congested(&fsc
->backing_dev_info
, BLK_RW_ASYNC
);
496 set_page_writeback(page
);
497 err
= ceph_osdc_writepages(osdc
, ceph_vino(inode
),
498 &ci
->i_layout
, snapc
,
500 truncate_seq
, truncate_size
,
501 &inode
->i_mtime
, &page
, 1);
503 dout("writepage setting page/mapping error %d %p\n", err
, page
);
505 mapping_set_error(&inode
->i_data
, err
);
507 wbc
->pages_skipped
++;
509 dout("writepage cleaned page %p\n", page
);
510 err
= 0; /* vfs expects us to return 0 */
513 ClearPagePrivate(page
);
514 end_page_writeback(page
);
515 ceph_put_wrbuffer_cap_refs(ci
, 1, snapc
);
516 ceph_put_snap_context(snapc
); /* page's reference */
521 static int ceph_writepage(struct page
*page
, struct writeback_control
*wbc
)
524 struct inode
*inode
= page
->mapping
->host
;
527 err
= writepage_nounlock(page
, wbc
);
535 * lame release_pages helper. release_pages() isn't exported to
538 static void ceph_release_pages(struct page
**pages
, int num
)
543 pagevec_init(&pvec
, 0);
544 for (i
= 0; i
< num
; i
++) {
545 if (pagevec_add(&pvec
, pages
[i
]) == 0)
546 pagevec_release(&pvec
);
548 pagevec_release(&pvec
);
553 * async writeback completion handler.
555 * If we get an error, set the mapping error bit, but not the individual
558 static void writepages_finish(struct ceph_osd_request
*req
,
559 struct ceph_msg
*msg
)
561 struct inode
*inode
= req
->r_inode
;
562 struct ceph_inode_info
*ci
= ceph_inode(inode
);
563 struct ceph_osd_data
*osd_data
;
568 struct ceph_snap_context
*snapc
= req
->r_snapc
;
569 struct address_space
*mapping
= inode
->i_mapping
;
570 int rc
= req
->r_result
;
571 u64 bytes
= req
->r_ops
[0].extent
.length
;
572 struct ceph_fs_client
*fsc
= ceph_inode_to_client(inode
);
574 unsigned issued
= ceph_caps_issued(ci
);
576 osd_data
= osd_req_op_extent_osd_data(req
, 0);
577 BUG_ON(osd_data
->type
!= CEPH_OSD_DATA_TYPE_PAGES
);
578 num_pages
= calc_pages_for((u64
)osd_data
->alignment
,
579 (u64
)osd_data
->length
);
582 * Assume we wrote the pages we originally sent. The
583 * osd might reply with fewer pages if our writeback
584 * raced with a truncation and was adjusted at the osd,
585 * so don't believe the reply.
590 mapping_set_error(mapping
, rc
);
592 dout("writepages_finish %p rc %d bytes %llu wrote %d (pages)\n",
593 inode
, rc
, bytes
, wrote
);
595 /* clean all pages */
596 for (i
= 0; i
< num_pages
; i
++) {
597 page
= osd_data
->pages
[i
];
599 WARN_ON(!PageUptodate(page
));
602 atomic_long_dec_return(&fsc
->writeback_count
);
604 CONGESTION_OFF_THRESH(fsc
->mount_options
->congestion_kb
))
605 clear_bdi_congested(&fsc
->backing_dev_info
,
608 ceph_put_snap_context(page_snap_context(page
));
610 ClearPagePrivate(page
);
611 dout("unlocking %d %p\n", i
, page
);
612 end_page_writeback(page
);
615 * We lost the cache cap, need to truncate the page before
616 * it is unlocked, otherwise we'd truncate it later in the
617 * page truncation thread, possibly losing some data that
620 if ((issued
& (CEPH_CAP_FILE_CACHE
|CEPH_CAP_FILE_LAZYIO
)) == 0)
621 generic_error_remove_page(inode
->i_mapping
, page
);
625 dout("%p wrote+cleaned %d pages\n", inode
, wrote
);
626 ceph_put_wrbuffer_cap_refs(ci
, num_pages
, snapc
);
628 ceph_release_pages(osd_data
->pages
, num_pages
);
629 if (osd_data
->pages_from_pool
)
630 mempool_free(osd_data
->pages
,
631 ceph_sb_to_client(inode
->i_sb
)->wb_pagevec_pool
);
633 kfree(osd_data
->pages
);
634 ceph_osdc_put_request(req
);
638 * initiate async writeback
640 static int ceph_writepages_start(struct address_space
*mapping
,
641 struct writeback_control
*wbc
)
643 struct inode
*inode
= mapping
->host
;
644 struct ceph_inode_info
*ci
= ceph_inode(inode
);
645 struct ceph_fs_client
*fsc
= ceph_inode_to_client(inode
);
646 struct ceph_vino vino
= ceph_vino(inode
);
647 pgoff_t index
, start
, end
;
650 pgoff_t max_pages
= 0, max_pages_ever
= 0;
651 struct ceph_snap_context
*snapc
= NULL
, *last_snapc
= NULL
, *pgsnapc
;
655 unsigned wsize
= 1 << inode
->i_blkbits
;
656 struct ceph_osd_request
*req
= NULL
;
658 u64 truncate_size
, snap_size
;
662 * Include a 'sync' in the OSD request if this is a data
663 * integrity write (e.g., O_SYNC write or fsync()), or if our
664 * cap is being revoked.
666 if ((wbc
->sync_mode
== WB_SYNC_ALL
) ||
667 ceph_caps_revoking(ci
, CEPH_CAP_FILE_BUFFER
))
669 dout("writepages_start %p dosync=%d (mode=%s)\n",
671 wbc
->sync_mode
== WB_SYNC_NONE
? "NONE" :
672 (wbc
->sync_mode
== WB_SYNC_ALL
? "ALL" : "HOLD"));
674 if (fsc
->mount_state
== CEPH_MOUNT_SHUTDOWN
) {
675 pr_warning("writepage_start %p on forced umount\n", inode
);
676 return -EIO
; /* we're in a forced umount, don't write! */
678 if (fsc
->mount_options
->wsize
&& fsc
->mount_options
->wsize
< wsize
)
679 wsize
= fsc
->mount_options
->wsize
;
680 if (wsize
< PAGE_CACHE_SIZE
)
681 wsize
= PAGE_CACHE_SIZE
;
682 max_pages_ever
= wsize
>> PAGE_CACHE_SHIFT
;
684 pagevec_init(&pvec
, 0);
686 /* where to start/end? */
687 if (wbc
->range_cyclic
) {
688 start
= mapping
->writeback_index
; /* Start from prev offset */
690 dout(" cyclic, start at %lu\n", start
);
692 start
= wbc
->range_start
>> PAGE_CACHE_SHIFT
;
693 end
= wbc
->range_end
>> PAGE_CACHE_SHIFT
;
694 if (wbc
->range_start
== 0 && wbc
->range_end
== LLONG_MAX
)
697 dout(" not cyclic, %lu to %lu\n", start
, end
);
702 /* find oldest snap context with dirty data */
703 ceph_put_snap_context(snapc
);
705 snapc
= get_oldest_context(inode
, &snap_size
);
707 /* hmm, why does writepages get called when there
709 dout(" no snap context with dirty data?\n");
713 snap_size
= i_size_read(inode
);
714 dout(" oldest snapc is %p seq %lld (%d snaps)\n",
715 snapc
, snapc
->seq
, snapc
->num_snaps
);
717 spin_lock(&ci
->i_ceph_lock
);
718 truncate_seq
= ci
->i_truncate_seq
;
719 truncate_size
= ci
->i_truncate_size
;
721 snap_size
= i_size_read(inode
);
722 spin_unlock(&ci
->i_ceph_lock
);
724 if (last_snapc
&& snapc
!= last_snapc
) {
725 /* if we switched to a newer snapc, restart our scan at the
726 * start of the original file range. */
727 dout(" snapc differs from last pass, restarting at %lu\n",
733 while (!done
&& index
<= end
) {
734 int num_ops
= do_sync
? 2 : 1;
738 int pvec_pages
, locked_pages
;
739 struct page
**pages
= NULL
;
740 mempool_t
*pool
= NULL
; /* Becomes non-null if mempool used */
748 max_pages
= max_pages_ever
;
752 want
= min(end
- index
,
753 min((pgoff_t
)PAGEVEC_SIZE
,
754 max_pages
- (pgoff_t
)locked_pages
) - 1)
756 pvec_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
,
759 dout("pagevec_lookup_tag got %d\n", pvec_pages
);
760 if (!pvec_pages
&& !locked_pages
)
762 for (i
= 0; i
< pvec_pages
&& locked_pages
< max_pages
; i
++) {
763 page
= pvec
.pages
[i
];
764 dout("? %p idx %lu\n", page
, page
->index
);
765 if (locked_pages
== 0)
766 lock_page(page
); /* first page */
767 else if (!trylock_page(page
))
770 /* only dirty pages, or our accounting breaks */
771 if (unlikely(!PageDirty(page
)) ||
772 unlikely(page
->mapping
!= mapping
)) {
773 dout("!dirty or !mapping %p\n", page
);
777 if (!wbc
->range_cyclic
&& page
->index
> end
) {
778 dout("end of range %p\n", page
);
783 if (next
&& (page
->index
!= next
)) {
784 dout("not consecutive %p\n", page
);
788 if (wbc
->sync_mode
!= WB_SYNC_NONE
) {
789 dout("waiting on writeback %p\n", page
);
790 wait_on_page_writeback(page
);
792 if (page_offset(page
) >= snap_size
) {
793 dout("%p page eof %llu\n", page
, snap_size
);
798 if (PageWriteback(page
)) {
799 dout("%p under writeback\n", page
);
804 /* only if matching snap context */
805 pgsnapc
= page_snap_context(page
);
806 if (pgsnapc
->seq
> snapc
->seq
) {
807 dout("page snapc %p %lld > oldest %p %lld\n",
808 pgsnapc
, pgsnapc
->seq
, snapc
, snapc
->seq
);
811 continue; /* keep looking for snap */
815 if (!clear_page_dirty_for_io(page
)) {
816 dout("%p !clear_page_dirty_for_io\n", page
);
822 * We have something to write. If this is
823 * the first locked page this time through,
824 * allocate an osd request and a page array
827 if (locked_pages
== 0) {
829 /* prepare async write request */
830 offset
= (u64
)page_offset(page
);
832 req
= ceph_osdc_new_request(&fsc
->client
->osdc
,
834 offset
, &len
, num_ops
,
836 CEPH_OSD_FLAG_WRITE
|
837 CEPH_OSD_FLAG_ONDISK
,
839 truncate_size
, true);
846 req
->r_callback
= writepages_finish
;
847 req
->r_inode
= inode
;
849 max_pages
= calc_pages_for(0, (u64
)len
);
850 pages
= kmalloc(max_pages
* sizeof (*pages
),
853 pool
= fsc
->wb_pagevec_pool
;
854 pages
= mempool_alloc(pool
, GFP_NOFS
);
859 /* note position of first page in pvec */
862 dout("%p will write page %p idx %lu\n",
863 inode
, page
, page
->index
);
866 atomic_long_inc_return(&fsc
->writeback_count
);
867 if (writeback_stat
> CONGESTION_ON_THRESH(
868 fsc
->mount_options
->congestion_kb
)) {
869 set_bdi_congested(&fsc
->backing_dev_info
,
873 set_page_writeback(page
);
874 pages
[locked_pages
] = page
;
876 next
= page
->index
+ 1;
879 /* did we get anything? */
881 goto release_pvec_pages
;
884 BUG_ON(!locked_pages
|| first
< 0);
886 if (pvec_pages
&& i
== pvec_pages
&&
887 locked_pages
< max_pages
) {
888 dout("reached end pvec, trying for more\n");
889 pagevec_reinit(&pvec
);
893 /* shift unused pages over in the pvec... we
894 * will need to release them below. */
895 for (j
= i
; j
< pvec_pages
; j
++) {
896 dout(" pvec leftover page %p\n",
898 pvec
.pages
[j
-i
+first
] = pvec
.pages
[j
];
903 /* Format the osd request message and submit the write */
905 offset
= page_offset(pages
[0]);
906 len
= min(snap_size
- offset
,
907 (u64
)locked_pages
<< PAGE_CACHE_SHIFT
);
908 dout("writepages got %d pages at %llu~%llu\n",
909 locked_pages
, offset
, len
);
911 osd_req_op_extent_osd_data_pages(req
, 0, pages
, len
, 0,
914 pages
= NULL
; /* request message now owns the pages array */
917 /* Update the write op length in case we changed it */
919 osd_req_op_extent_update(req
, 0, len
);
921 vino
= ceph_vino(inode
);
922 ceph_osdc_build_request(req
, offset
, snapc
, vino
.snap
,
925 rc
= ceph_osdc_start_request(&fsc
->client
->osdc
, req
, true);
931 wbc
->nr_to_write
-= locked_pages
;
932 if (wbc
->nr_to_write
<= 0)
936 dout("pagevec_release on %d pages (%p)\n", (int)pvec
.nr
,
937 pvec
.nr
? pvec
.pages
[0] : NULL
);
938 pagevec_release(&pvec
);
940 if (locked_pages
&& !done
)
944 if (should_loop
&& !done
) {
945 /* more to do; loop back to beginning of file */
946 dout("writepages looping back to beginning of file\n");
952 if (wbc
->range_cyclic
|| (range_whole
&& wbc
->nr_to_write
> 0))
953 mapping
->writeback_index
= index
;
957 ceph_osdc_put_request(req
);
958 ceph_put_snap_context(snapc
);
959 dout("writepages done, rc = %d\n", rc
);
966 * See if a given @snapc is either writeable, or already written.
968 static int context_is_writeable_or_written(struct inode
*inode
,
969 struct ceph_snap_context
*snapc
)
971 struct ceph_snap_context
*oldest
= get_oldest_context(inode
, NULL
);
972 int ret
= !oldest
|| snapc
->seq
<= oldest
->seq
;
974 ceph_put_snap_context(oldest
);
979 * We are only allowed to write into/dirty the page if the page is
980 * clean, or already dirty within the same snap context.
982 * called with page locked.
983 * return success with page locked,
984 * or any failure (incl -EAGAIN) with page unlocked.
986 static int ceph_update_writeable_page(struct file
*file
,
987 loff_t pos
, unsigned len
,
990 struct inode
*inode
= file_inode(file
);
991 struct ceph_inode_info
*ci
= ceph_inode(inode
);
992 struct ceph_mds_client
*mdsc
= ceph_inode_to_client(inode
)->mdsc
;
993 loff_t page_off
= pos
& PAGE_CACHE_MASK
;
994 int pos_in_page
= pos
& ~PAGE_CACHE_MASK
;
995 int end_in_page
= pos_in_page
+ len
;
998 struct ceph_snap_context
*snapc
, *oldest
;
1001 /* writepages currently holds page lock, but if we change that later, */
1002 wait_on_page_writeback(page
);
1004 /* check snap context */
1005 BUG_ON(!ci
->i_snap_realm
);
1006 down_read(&mdsc
->snap_rwsem
);
1007 BUG_ON(!ci
->i_snap_realm
->cached_context
);
1008 snapc
= page_snap_context(page
);
1009 if (snapc
&& snapc
!= ci
->i_head_snapc
) {
1011 * this page is already dirty in another (older) snap
1012 * context! is it writeable now?
1014 oldest
= get_oldest_context(inode
, NULL
);
1015 up_read(&mdsc
->snap_rwsem
);
1017 if (snapc
->seq
> oldest
->seq
) {
1018 ceph_put_snap_context(oldest
);
1019 dout(" page %p snapc %p not current or oldest\n",
1022 * queue for writeback, and wait for snapc to
1023 * be writeable or written
1025 snapc
= ceph_get_snap_context(snapc
);
1027 ceph_queue_writeback(inode
);
1028 r
= wait_event_interruptible(ci
->i_cap_wq
,
1029 context_is_writeable_or_written(inode
, snapc
));
1030 ceph_put_snap_context(snapc
);
1031 if (r
== -ERESTARTSYS
)
1035 ceph_put_snap_context(oldest
);
1037 /* yay, writeable, do it now (without dropping page lock) */
1038 dout(" page %p snapc %p not current, but oldest\n",
1040 if (!clear_page_dirty_for_io(page
))
1042 r
= writepage_nounlock(page
, NULL
);
1048 if (PageUptodate(page
)) {
1049 dout(" page %p already uptodate\n", page
);
1054 if (pos_in_page
== 0 && len
== PAGE_CACHE_SIZE
)
1057 /* past end of file? */
1058 i_size
= inode
->i_size
; /* caller holds i_mutex */
1060 if (i_size
+ len
> inode
->i_sb
->s_maxbytes
) {
1061 /* file is too big */
1066 if (page_off
>= i_size
||
1067 (pos_in_page
== 0 && (pos
+len
) >= i_size
&&
1068 end_in_page
- pos_in_page
!= PAGE_CACHE_SIZE
)) {
1069 dout(" zeroing %p 0 - %d and %d - %d\n",
1070 page
, pos_in_page
, end_in_page
, (int)PAGE_CACHE_SIZE
);
1071 zero_user_segments(page
,
1073 end_in_page
, PAGE_CACHE_SIZE
);
1077 /* we need to read it. */
1078 up_read(&mdsc
->snap_rwsem
);
1079 r
= readpage_nounlock(file
, page
);
1085 up_read(&mdsc
->snap_rwsem
);
1092 * We are only allowed to write into/dirty the page if the page is
1093 * clean, or already dirty within the same snap context.
1095 static int ceph_write_begin(struct file
*file
, struct address_space
*mapping
,
1096 loff_t pos
, unsigned len
, unsigned flags
,
1097 struct page
**pagep
, void **fsdata
)
1099 struct inode
*inode
= file_inode(file
);
1101 pgoff_t index
= pos
>> PAGE_CACHE_SHIFT
;
1106 page
= grab_cache_page_write_begin(mapping
, index
, 0);
1111 dout("write_begin file %p inode %p page %p %d~%d\n", file
,
1112 inode
, page
, (int)pos
, (int)len
);
1114 r
= ceph_update_writeable_page(file
, pos
, len
, page
);
1115 } while (r
== -EAGAIN
);
1121 * we don't do anything in here that simple_write_end doesn't do
1122 * except adjust dirty page accounting and drop read lock on
1125 static int ceph_write_end(struct file
*file
, struct address_space
*mapping
,
1126 loff_t pos
, unsigned len
, unsigned copied
,
1127 struct page
*page
, void *fsdata
)
1129 struct inode
*inode
= file_inode(file
);
1130 struct ceph_fs_client
*fsc
= ceph_inode_to_client(inode
);
1131 struct ceph_mds_client
*mdsc
= fsc
->mdsc
;
1132 unsigned from
= pos
& (PAGE_CACHE_SIZE
- 1);
1135 dout("write_end file %p inode %p page %p %d~%d (%d)\n", file
,
1136 inode
, page
, (int)pos
, (int)copied
, (int)len
);
1138 /* zero the stale part of the page if we did a short copy */
1140 zero_user_segment(page
, from
+copied
, len
);
1142 /* did file size increase? */
1143 /* (no need for i_size_read(); we caller holds i_mutex */
1144 if (pos
+copied
> inode
->i_size
)
1145 check_cap
= ceph_inode_set_size(inode
, pos
+copied
);
1147 if (!PageUptodate(page
))
1148 SetPageUptodate(page
);
1150 set_page_dirty(page
);
1153 up_read(&mdsc
->snap_rwsem
);
1154 page_cache_release(page
);
1157 ceph_check_caps(ceph_inode(inode
), CHECK_CAPS_AUTHONLY
, NULL
);
1163 * we set .direct_IO to indicate direct io is supported, but since we
1164 * intercept O_DIRECT reads and writes early, this function should
1167 static ssize_t
ceph_direct_io(int rw
, struct kiocb
*iocb
,
1168 const struct iovec
*iov
,
1169 loff_t pos
, unsigned long nr_segs
)
1175 const struct address_space_operations ceph_aops
= {
1176 .readpage
= ceph_readpage
,
1177 .readpages
= ceph_readpages
,
1178 .writepage
= ceph_writepage
,
1179 .writepages
= ceph_writepages_start
,
1180 .write_begin
= ceph_write_begin
,
1181 .write_end
= ceph_write_end
,
1182 .set_page_dirty
= ceph_set_page_dirty
,
1183 .invalidatepage
= ceph_invalidatepage
,
1184 .releasepage
= ceph_releasepage
,
1185 .direct_IO
= ceph_direct_io
,
1194 * Reuse write_begin here for simplicity.
1196 static int ceph_page_mkwrite(struct vm_area_struct
*vma
, struct vm_fault
*vmf
)
1198 struct inode
*inode
= file_inode(vma
->vm_file
);
1199 struct page
*page
= vmf
->page
;
1200 struct ceph_mds_client
*mdsc
= ceph_inode_to_client(inode
)->mdsc
;
1201 loff_t off
= page_offset(page
);
1205 /* Update time before taking page lock */
1206 file_update_time(vma
->vm_file
);
1208 size
= i_size_read(inode
);
1209 if (off
+ PAGE_CACHE_SIZE
<= size
)
1210 len
= PAGE_CACHE_SIZE
;
1212 len
= size
& ~PAGE_CACHE_MASK
;
1214 dout("page_mkwrite %p %llu~%llu page %p idx %lu\n", inode
,
1215 off
, len
, page
, page
->index
);
1219 ret
= VM_FAULT_NOPAGE
;
1221 (page
->mapping
!= inode
->i_mapping
))
1224 ret
= ceph_update_writeable_page(vma
->vm_file
, off
, len
, page
);
1226 /* success. we'll keep the page locked. */
1227 set_page_dirty(page
);
1228 up_read(&mdsc
->snap_rwsem
);
1229 ret
= VM_FAULT_LOCKED
;
1234 ret
= VM_FAULT_SIGBUS
;
1237 dout("page_mkwrite %p %llu~%llu = %d\n", inode
, off
, len
, ret
);
1238 if (ret
!= VM_FAULT_LOCKED
)
1243 static struct vm_operations_struct ceph_vmops
= {
1244 .fault
= filemap_fault
,
1245 .page_mkwrite
= ceph_page_mkwrite
,
1246 .remap_pages
= generic_file_remap_pages
,
1249 int ceph_mmap(struct file
*file
, struct vm_area_struct
*vma
)
1251 struct address_space
*mapping
= file
->f_mapping
;
1253 if (!mapping
->a_ops
->readpage
)
1255 file_accessed(file
);
1256 vma
->vm_ops
= &ceph_vmops
;