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"
15 #include <linux/ceph/osd_client.h>
18 * Ceph address space ops.
20 * There are a few funny things going on here.
22 * The page->private field is used to reference a struct
23 * ceph_snap_context for _every_ dirty page. This indicates which
24 * snapshot the page was logically dirtied in, and thus which snap
25 * context needs to be associated with the osd write during writeback.
27 * Similarly, struct ceph_inode_info maintains a set of counters to
28 * count dirty pages on the inode. In the absence of snapshots,
29 * i_wrbuffer_ref == i_wrbuffer_ref_head == the dirty page count.
31 * When a snapshot is taken (that is, when the client receives
32 * notification that a snapshot was taken), each inode with caps and
33 * with dirty pages (dirty pages implies there is a cap) gets a new
34 * ceph_cap_snap in the i_cap_snaps list (which is sorted in ascending
35 * order, new snaps go to the tail). The i_wrbuffer_ref_head count is
36 * moved to capsnap->dirty. (Unless a sync write is currently in
37 * progress. In that case, the capsnap is said to be "pending", new
38 * writes cannot start, and the capsnap isn't "finalized" until the
39 * write completes (or fails) and a final size/mtime for the inode for
40 * that snap can be settled upon.) i_wrbuffer_ref_head is reset to 0.
42 * On writeback, we must submit writes to the osd IN SNAP ORDER. So,
43 * we look for the first capsnap in i_cap_snaps and write out pages in
44 * that snap context _only_. Then we move on to the next capsnap,
45 * eventually reaching the "live" or "head" context (i.e., pages that
46 * are not yet snapped) and are writing the most recently dirtied
49 * Invalidate and so forth must take care to ensure the dirty page
50 * accounting is preserved.
53 #define CONGESTION_ON_THRESH(congestion_kb) (congestion_kb >> (PAGE_SHIFT-10))
54 #define CONGESTION_OFF_THRESH(congestion_kb) \
55 (CONGESTION_ON_THRESH(congestion_kb) - \
56 (CONGESTION_ON_THRESH(congestion_kb) >> 2))
58 static inline struct ceph_snap_context *page_snap_context(struct page *page)
60 if (PagePrivate(page))
61 return (void *)page->private;
66 * Dirty a page. Optimistically adjust accounting, on the assumption
67 * that we won't race with invalidate. If we do, readjust.
69 static int ceph_set_page_dirty(struct page *page)
71 struct address_space *mapping = page->mapping;
73 struct ceph_inode_info *ci;
74 struct ceph_snap_context *snapc;
77 if (unlikely(!mapping))
78 return !TestSetPageDirty(page);
80 if (PageDirty(page)) {
81 dout("%p set_page_dirty %p idx %lu -- already dirty\n",
82 mapping->host, page, page->index);
83 BUG_ON(!PagePrivate(page));
87 inode = mapping->host;
88 ci = ceph_inode(inode);
91 * Note that we're grabbing a snapc ref here without holding
94 snapc = ceph_get_snap_context(ci->i_snap_realm->cached_context);
97 spin_lock(&ci->i_ceph_lock);
98 if (ci->i_head_snapc == NULL)
99 ci->i_head_snapc = ceph_get_snap_context(snapc);
100 ++ci->i_wrbuffer_ref_head;
101 if (ci->i_wrbuffer_ref == 0)
103 ++ci->i_wrbuffer_ref;
104 dout("%p set_page_dirty %p idx %lu head %d/%d -> %d/%d "
105 "snapc %p seq %lld (%d snaps)\n",
106 mapping->host, page, page->index,
107 ci->i_wrbuffer_ref-1, ci->i_wrbuffer_ref_head-1,
108 ci->i_wrbuffer_ref, ci->i_wrbuffer_ref_head,
109 snapc, snapc->seq, snapc->num_snaps);
110 spin_unlock(&ci->i_ceph_lock);
113 * Reference snap context in page->private. Also set
114 * PagePrivate so that we get invalidatepage callback.
116 BUG_ON(PagePrivate(page));
117 page->private = (unsigned long)snapc;
118 SetPagePrivate(page);
120 ret = __set_page_dirty_nobuffers(page);
121 WARN_ON(!PageLocked(page));
122 WARN_ON(!page->mapping);
128 * If we are truncating the full page (i.e. offset == 0), adjust the
129 * dirty page counters appropriately. Only called if there is private
132 static void ceph_invalidatepage(struct page *page, unsigned int offset,
136 struct ceph_inode_info *ci;
137 struct ceph_snap_context *snapc = page_snap_context(page);
139 inode = page->mapping->host;
140 ci = ceph_inode(inode);
142 if (offset != 0 || length != PAGE_CACHE_SIZE) {
143 dout("%p invalidatepage %p idx %lu partial dirty page %u~%u\n",
144 inode, page, page->index, offset, length);
148 ceph_invalidate_fscache_page(inode, page);
150 if (!PagePrivate(page))
154 * We can get non-dirty pages here due to races between
155 * set_page_dirty and truncate_complete_page; just spit out a
156 * warning, in case we end up with accounting problems later.
158 if (!PageDirty(page))
159 pr_err("%p invalidatepage %p page not dirty\n", inode, page);
161 ClearPageChecked(page);
163 dout("%p invalidatepage %p idx %lu full dirty page\n",
164 inode, page, page->index);
166 ceph_put_wrbuffer_cap_refs(ci, 1, snapc);
167 ceph_put_snap_context(snapc);
169 ClearPagePrivate(page);
172 static int ceph_releasepage(struct page *page, gfp_t g)
174 struct inode *inode = page->mapping ? page->mapping->host : NULL;
175 dout("%p releasepage %p idx %lu\n", inode, page, page->index);
176 WARN_ON(PageDirty(page));
178 /* Can we release the page from the cache? */
179 if (!ceph_release_fscache_page(page, g))
182 return !PagePrivate(page);
186 * read a single page, without unlocking it.
188 static int readpage_nounlock(struct file *filp, struct page *page)
190 struct inode *inode = file_inode(filp);
191 struct ceph_inode_info *ci = ceph_inode(inode);
192 struct ceph_osd_client *osdc =
193 &ceph_inode_to_client(inode)->client->osdc;
195 u64 off = page_offset(page);
196 u64 len = PAGE_CACHE_SIZE;
198 if (off >= i_size_read(inode)) {
199 zero_user_segment(page, err, PAGE_CACHE_SIZE);
200 SetPageUptodate(page);
205 * Uptodate inline data should have been added into page cache
206 * while getting Fcr caps.
208 if (ci->i_inline_version != CEPH_INLINE_NONE)
211 err = ceph_readpage_from_fscache(inode, page);
215 dout("readpage inode %p file %p page %p index %lu\n",
216 inode, filp, page, page->index);
217 err = ceph_osdc_readpages(osdc, ceph_vino(inode), &ci->i_layout,
219 ci->i_truncate_seq, ci->i_truncate_size,
225 ceph_fscache_readpage_cancel(inode, page);
228 if (err < PAGE_CACHE_SIZE)
229 /* zero fill remainder of page */
230 zero_user_segment(page, err, PAGE_CACHE_SIZE);
232 flush_dcache_page(page);
234 SetPageUptodate(page);
235 ceph_readpage_to_fscache(inode, page);
238 return err < 0 ? err : 0;
241 static int ceph_readpage(struct file *filp, struct page *page)
243 int r = readpage_nounlock(filp, page);
249 * Finish an async read(ahead) op.
251 static void finish_read(struct ceph_osd_request *req, struct ceph_msg *msg)
253 struct inode *inode = req->r_inode;
254 struct ceph_osd_data *osd_data;
255 int rc = req->r_result;
256 int bytes = le32_to_cpu(msg->hdr.data_len);
260 dout("finish_read %p req %p rc %d bytes %d\n", inode, req, rc, bytes);
262 /* unlock all pages, zeroing any data we didn't read */
263 osd_data = osd_req_op_extent_osd_data(req, 0);
264 BUG_ON(osd_data->type != CEPH_OSD_DATA_TYPE_PAGES);
265 num_pages = calc_pages_for((u64)osd_data->alignment,
266 (u64)osd_data->length);
267 for (i = 0; i < num_pages; i++) {
268 struct page *page = osd_data->pages[i];
272 if (bytes < (int)PAGE_CACHE_SIZE) {
273 /* zero (remainder of) page */
274 int s = bytes < 0 ? 0 : bytes;
275 zero_user_segment(page, s, PAGE_CACHE_SIZE);
277 dout("finish_read %p uptodate %p idx %lu\n", inode, page,
279 flush_dcache_page(page);
280 SetPageUptodate(page);
281 ceph_readpage_to_fscache(inode, page);
284 page_cache_release(page);
285 bytes -= PAGE_CACHE_SIZE;
287 kfree(osd_data->pages);
290 static void ceph_unlock_page_vector(struct page **pages, int num_pages)
294 for (i = 0; i < num_pages; i++)
295 unlock_page(pages[i]);
299 * start an async read(ahead) operation. return nr_pages we submitted
300 * a read for on success, or negative error code.
302 static int start_read(struct inode *inode, struct list_head *page_list, int max)
304 struct ceph_osd_client *osdc =
305 &ceph_inode_to_client(inode)->client->osdc;
306 struct ceph_inode_info *ci = ceph_inode(inode);
307 struct page *page = list_entry(page_list->prev, struct page, lru);
308 struct ceph_vino vino;
309 struct ceph_osd_request *req;
318 off = (u64) page_offset(page);
321 next_index = page->index;
322 list_for_each_entry_reverse(page, page_list, lru) {
323 if (page->index != next_index)
327 if (max && nr_pages == max)
330 len = nr_pages << PAGE_CACHE_SHIFT;
331 dout("start_read %p nr_pages %d is %lld~%lld\n", inode, nr_pages,
333 vino = ceph_vino(inode);
334 req = ceph_osdc_new_request(osdc, &ci->i_layout, vino, off, &len,
335 0, 1, CEPH_OSD_OP_READ,
336 CEPH_OSD_FLAG_READ, NULL,
337 ci->i_truncate_seq, ci->i_truncate_size,
342 /* build page vector */
343 nr_pages = calc_pages_for(0, len);
344 pages = kmalloc(sizeof(*pages) * nr_pages, GFP_NOFS);
348 for (i = 0; i < nr_pages; ++i) {
349 page = list_entry(page_list->prev, struct page, lru);
350 BUG_ON(PageLocked(page));
351 list_del(&page->lru);
353 dout("start_read %p adding %p idx %lu\n", inode, page,
355 if (add_to_page_cache_lru(page, &inode->i_data, page->index,
357 ceph_fscache_uncache_page(inode, page);
358 page_cache_release(page);
359 dout("start_read %p add_to_page_cache failed %p\n",
366 osd_req_op_extent_osd_data_pages(req, 0, pages, len, 0, false, false);
367 req->r_callback = finish_read;
368 req->r_inode = inode;
370 ceph_osdc_build_request(req, off, NULL, vino.snap, NULL);
372 dout("start_read %p starting %p %lld~%lld\n", inode, req, off, len);
373 ret = ceph_osdc_start_request(osdc, req, false);
376 ceph_osdc_put_request(req);
380 ceph_unlock_page_vector(pages, nr_pages);
381 ceph_release_page_vector(pages, nr_pages);
383 ceph_osdc_put_request(req);
389 * Read multiple pages. Leave pages we don't read + unlock in page_list;
390 * the caller (VM) cleans them up.
392 static int ceph_readpages(struct file *file, struct address_space *mapping,
393 struct list_head *page_list, unsigned nr_pages)
395 struct inode *inode = file_inode(file);
396 struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
400 if (ceph_inode(inode)->i_inline_version != CEPH_INLINE_NONE)
403 rc = ceph_readpages_from_fscache(mapping->host, mapping, page_list,
409 if (fsc->mount_options->rsize >= PAGE_CACHE_SIZE)
410 max = (fsc->mount_options->rsize + PAGE_CACHE_SIZE - 1)
413 dout("readpages %p file %p nr_pages %d max %d\n", inode,
416 while (!list_empty(page_list)) {
417 rc = start_read(inode, page_list, max);
423 ceph_fscache_readpages_cancel(inode, page_list);
425 dout("readpages %p file %p ret %d\n", inode, file, rc);
430 * Get ref for the oldest snapc for an inode with dirty data... that is, the
431 * only snap context we are allowed to write back.
433 static struct ceph_snap_context *get_oldest_context(struct inode *inode,
436 struct ceph_inode_info *ci = ceph_inode(inode);
437 struct ceph_snap_context *snapc = NULL;
438 struct ceph_cap_snap *capsnap = NULL;
440 spin_lock(&ci->i_ceph_lock);
441 list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) {
442 dout(" cap_snap %p snapc %p has %d dirty pages\n", capsnap,
443 capsnap->context, capsnap->dirty_pages);
444 if (capsnap->dirty_pages) {
445 snapc = ceph_get_snap_context(capsnap->context);
447 *snap_size = capsnap->size;
451 if (!snapc && ci->i_wrbuffer_ref_head) {
452 snapc = ceph_get_snap_context(ci->i_head_snapc);
453 dout(" head snapc %p has %d dirty pages\n",
454 snapc, ci->i_wrbuffer_ref_head);
456 spin_unlock(&ci->i_ceph_lock);
461 * Write a single page, but leave the page locked.
463 * If we get a write error, set the page error bit, but still adjust the
464 * dirty page accounting (i.e., page is no longer dirty).
466 static int writepage_nounlock(struct page *page, struct writeback_control *wbc)
469 struct ceph_inode_info *ci;
470 struct ceph_fs_client *fsc;
471 struct ceph_osd_client *osdc;
472 struct ceph_snap_context *snapc, *oldest;
473 loff_t page_off = page_offset(page);
475 u64 truncate_size, snap_size = 0;
477 int err = 0, len = PAGE_CACHE_SIZE;
479 dout("writepage %p idx %lu\n", page, page->index);
481 if (!page->mapping || !page->mapping->host) {
482 dout("writepage %p - no mapping\n", page);
485 inode = page->mapping->host;
486 ci = ceph_inode(inode);
487 fsc = ceph_inode_to_client(inode);
488 osdc = &fsc->client->osdc;
490 /* verify this is a writeable snap context */
491 snapc = page_snap_context(page);
493 dout("writepage %p page %p not dirty?\n", inode, page);
496 oldest = get_oldest_context(inode, &snap_size);
497 if (snapc->seq > oldest->seq) {
498 dout("writepage %p page %p snapc %p not writeable - noop\n",
500 /* we should only noop if called by kswapd */
501 WARN_ON((current->flags & PF_MEMALLOC) == 0);
502 ceph_put_snap_context(oldest);
505 ceph_put_snap_context(oldest);
507 spin_lock(&ci->i_ceph_lock);
508 truncate_seq = ci->i_truncate_seq;
509 truncate_size = ci->i_truncate_size;
511 snap_size = i_size_read(inode);
512 spin_unlock(&ci->i_ceph_lock);
514 /* is this a partial page at end of file? */
515 if (page_off >= snap_size) {
516 dout("%p page eof %llu\n", page, snap_size);
519 if (snap_size < page_off + len)
520 len = snap_size - page_off;
522 dout("writepage %p page %p index %lu on %llu~%u snapc %p\n",
523 inode, page, page->index, page_off, len, snapc);
525 writeback_stat = atomic_long_inc_return(&fsc->writeback_count);
527 CONGESTION_ON_THRESH(fsc->mount_options->congestion_kb))
528 set_bdi_congested(&fsc->backing_dev_info, BLK_RW_ASYNC);
530 ceph_readpage_to_fscache(inode, page);
532 set_page_writeback(page);
533 err = ceph_osdc_writepages(osdc, ceph_vino(inode),
534 &ci->i_layout, snapc,
536 truncate_seq, truncate_size,
537 &inode->i_mtime, &page, 1);
539 dout("writepage setting page/mapping error %d %p\n", err, page);
541 mapping_set_error(&inode->i_data, err);
543 wbc->pages_skipped++;
545 dout("writepage cleaned page %p\n", page);
546 err = 0; /* vfs expects us to return 0 */
549 ClearPagePrivate(page);
550 end_page_writeback(page);
551 ceph_put_wrbuffer_cap_refs(ci, 1, snapc);
552 ceph_put_snap_context(snapc); /* page's reference */
557 static int ceph_writepage(struct page *page, struct writeback_control *wbc)
560 struct inode *inode = page->mapping->host;
563 err = writepage_nounlock(page, wbc);
571 * lame release_pages helper. release_pages() isn't exported to
574 static void ceph_release_pages(struct page **pages, int num)
579 pagevec_init(&pvec, 0);
580 for (i = 0; i < num; i++) {
581 if (pagevec_add(&pvec, pages[i]) == 0)
582 pagevec_release(&pvec);
584 pagevec_release(&pvec);
588 * async writeback completion handler.
590 * If we get an error, set the mapping error bit, but not the individual
593 static void writepages_finish(struct ceph_osd_request *req,
594 struct ceph_msg *msg)
596 struct inode *inode = req->r_inode;
597 struct ceph_inode_info *ci = ceph_inode(inode);
598 struct ceph_osd_data *osd_data;
603 struct ceph_snap_context *snapc = req->r_snapc;
604 struct address_space *mapping = inode->i_mapping;
605 int rc = req->r_result;
606 u64 bytes = req->r_ops[0].extent.length;
607 struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
609 unsigned issued = ceph_caps_issued(ci);
611 osd_data = osd_req_op_extent_osd_data(req, 0);
612 BUG_ON(osd_data->type != CEPH_OSD_DATA_TYPE_PAGES);
613 num_pages = calc_pages_for((u64)osd_data->alignment,
614 (u64)osd_data->length);
617 * Assume we wrote the pages we originally sent. The
618 * osd might reply with fewer pages if our writeback
619 * raced with a truncation and was adjusted at the osd,
620 * so don't believe the reply.
625 mapping_set_error(mapping, rc);
627 dout("writepages_finish %p rc %d bytes %llu wrote %d (pages)\n",
628 inode, rc, bytes, wrote);
630 /* clean all pages */
631 for (i = 0; i < num_pages; i++) {
632 page = osd_data->pages[i];
634 WARN_ON(!PageUptodate(page));
637 atomic_long_dec_return(&fsc->writeback_count);
639 CONGESTION_OFF_THRESH(fsc->mount_options->congestion_kb))
640 clear_bdi_congested(&fsc->backing_dev_info,
643 ceph_put_snap_context(page_snap_context(page));
645 ClearPagePrivate(page);
646 dout("unlocking %d %p\n", i, page);
647 end_page_writeback(page);
650 * We lost the cache cap, need to truncate the page before
651 * it is unlocked, otherwise we'd truncate it later in the
652 * page truncation thread, possibly losing some data that
655 if ((issued & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) == 0)
656 generic_error_remove_page(inode->i_mapping, page);
660 dout("%p wrote+cleaned %d pages\n", inode, wrote);
661 ceph_put_wrbuffer_cap_refs(ci, num_pages, snapc);
663 ceph_release_pages(osd_data->pages, num_pages);
664 if (osd_data->pages_from_pool)
665 mempool_free(osd_data->pages,
666 ceph_sb_to_client(inode->i_sb)->wb_pagevec_pool);
668 kfree(osd_data->pages);
669 ceph_osdc_put_request(req);
673 * initiate async writeback
675 static int ceph_writepages_start(struct address_space *mapping,
676 struct writeback_control *wbc)
678 struct inode *inode = mapping->host;
679 struct ceph_inode_info *ci = ceph_inode(inode);
680 struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
681 struct ceph_vino vino = ceph_vino(inode);
682 pgoff_t index, start, end;
685 pgoff_t max_pages = 0, max_pages_ever = 0;
686 struct ceph_snap_context *snapc = NULL, *last_snapc = NULL, *pgsnapc;
690 unsigned wsize = 1 << inode->i_blkbits;
691 struct ceph_osd_request *req = NULL;
693 u64 truncate_size, snap_size;
697 * Include a 'sync' in the OSD request if this is a data
698 * integrity write (e.g., O_SYNC write or fsync()), or if our
699 * cap is being revoked.
701 if ((wbc->sync_mode == WB_SYNC_ALL) ||
702 ceph_caps_revoking(ci, CEPH_CAP_FILE_BUFFER))
704 dout("writepages_start %p dosync=%d (mode=%s)\n",
706 wbc->sync_mode == WB_SYNC_NONE ? "NONE" :
707 (wbc->sync_mode == WB_SYNC_ALL ? "ALL" : "HOLD"));
709 if (fsc->mount_state == CEPH_MOUNT_SHUTDOWN) {
710 pr_warn("writepage_start %p on forced umount\n", inode);
711 return -EIO; /* we're in a forced umount, don't write! */
713 if (fsc->mount_options->wsize && fsc->mount_options->wsize < wsize)
714 wsize = fsc->mount_options->wsize;
715 if (wsize < PAGE_CACHE_SIZE)
716 wsize = PAGE_CACHE_SIZE;
717 max_pages_ever = wsize >> PAGE_CACHE_SHIFT;
719 pagevec_init(&pvec, 0);
721 /* where to start/end? */
722 if (wbc->range_cyclic) {
723 start = mapping->writeback_index; /* Start from prev offset */
725 dout(" cyclic, start at %lu\n", start);
727 start = wbc->range_start >> PAGE_CACHE_SHIFT;
728 end = wbc->range_end >> PAGE_CACHE_SHIFT;
729 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
732 dout(" not cyclic, %lu to %lu\n", start, end);
737 /* find oldest snap context with dirty data */
738 ceph_put_snap_context(snapc);
740 snapc = get_oldest_context(inode, &snap_size);
742 /* hmm, why does writepages get called when there
744 dout(" no snap context with dirty data?\n");
748 snap_size = i_size_read(inode);
749 dout(" oldest snapc is %p seq %lld (%d snaps)\n",
750 snapc, snapc->seq, snapc->num_snaps);
752 spin_lock(&ci->i_ceph_lock);
753 truncate_seq = ci->i_truncate_seq;
754 truncate_size = ci->i_truncate_size;
756 snap_size = i_size_read(inode);
757 spin_unlock(&ci->i_ceph_lock);
759 if (last_snapc && snapc != last_snapc) {
760 /* if we switched to a newer snapc, restart our scan at the
761 * start of the original file range. */
762 dout(" snapc differs from last pass, restarting at %lu\n",
768 while (!done && index <= end) {
772 int pvec_pages, locked_pages;
773 struct page **pages = NULL;
774 mempool_t *pool = NULL; /* Becomes non-null if mempool used */
782 max_pages = max_pages_ever;
786 want = min(end - index,
787 min((pgoff_t)PAGEVEC_SIZE,
788 max_pages - (pgoff_t)locked_pages) - 1)
790 pvec_pages = pagevec_lookup_tag(&pvec, mapping, &index,
793 dout("pagevec_lookup_tag got %d\n", pvec_pages);
794 if (!pvec_pages && !locked_pages)
796 for (i = 0; i < pvec_pages && locked_pages < max_pages; i++) {
797 page = pvec.pages[i];
798 dout("? %p idx %lu\n", page, page->index);
799 if (locked_pages == 0)
800 lock_page(page); /* first page */
801 else if (!trylock_page(page))
804 /* only dirty pages, or our accounting breaks */
805 if (unlikely(!PageDirty(page)) ||
806 unlikely(page->mapping != mapping)) {
807 dout("!dirty or !mapping %p\n", page);
811 if (!wbc->range_cyclic && page->index > end) {
812 dout("end of range %p\n", page);
817 if (next && (page->index != next)) {
818 dout("not consecutive %p\n", page);
822 if (wbc->sync_mode != WB_SYNC_NONE) {
823 dout("waiting on writeback %p\n", page);
824 wait_on_page_writeback(page);
826 if (page_offset(page) >= snap_size) {
827 dout("%p page eof %llu\n", page, snap_size);
832 if (PageWriteback(page)) {
833 dout("%p under writeback\n", page);
838 /* only if matching snap context */
839 pgsnapc = page_snap_context(page);
840 if (pgsnapc->seq > snapc->seq) {
841 dout("page snapc %p %lld > oldest %p %lld\n",
842 pgsnapc, pgsnapc->seq, snapc, snapc->seq);
845 continue; /* keep looking for snap */
849 if (!clear_page_dirty_for_io(page)) {
850 dout("%p !clear_page_dirty_for_io\n", page);
856 * We have something to write. If this is
857 * the first locked page this time through,
858 * allocate an osd request and a page array
861 if (locked_pages == 0) {
863 /* prepare async write request */
864 offset = (u64)page_offset(page);
866 req = ceph_osdc_new_request(&fsc->client->osdc,
871 CEPH_OSD_FLAG_WRITE |
872 CEPH_OSD_FLAG_ONDISK,
874 truncate_size, true);
882 osd_req_op_init(req, 1, CEPH_OSD_OP_STARTSYNC);
884 req->r_callback = writepages_finish;
885 req->r_inode = inode;
887 max_pages = calc_pages_for(0, (u64)len);
888 pages = kmalloc(max_pages * sizeof (*pages),
891 pool = fsc->wb_pagevec_pool;
892 pages = mempool_alloc(pool, GFP_NOFS);
897 /* note position of first page in pvec */
900 dout("%p will write page %p idx %lu\n",
901 inode, page, page->index);
904 atomic_long_inc_return(&fsc->writeback_count);
905 if (writeback_stat > CONGESTION_ON_THRESH(
906 fsc->mount_options->congestion_kb)) {
907 set_bdi_congested(&fsc->backing_dev_info,
911 set_page_writeback(page);
912 pages[locked_pages] = page;
914 next = page->index + 1;
917 /* did we get anything? */
919 goto release_pvec_pages;
922 BUG_ON(!locked_pages || first < 0);
924 if (pvec_pages && i == pvec_pages &&
925 locked_pages < max_pages) {
926 dout("reached end pvec, trying for more\n");
927 pagevec_reinit(&pvec);
931 /* shift unused pages over in the pvec... we
932 * will need to release them below. */
933 for (j = i; j < pvec_pages; j++) {
934 dout(" pvec leftover page %p\n",
936 pvec.pages[j-i+first] = pvec.pages[j];
941 /* Format the osd request message and submit the write */
943 offset = page_offset(pages[0]);
944 len = min(snap_size - offset,
945 (u64)locked_pages << PAGE_CACHE_SHIFT);
946 dout("writepages got %d pages at %llu~%llu\n",
947 locked_pages, offset, len);
949 osd_req_op_extent_osd_data_pages(req, 0, pages, len, 0,
952 pages = NULL; /* request message now owns the pages array */
955 /* Update the write op length in case we changed it */
957 osd_req_op_extent_update(req, 0, len);
959 vino = ceph_vino(inode);
960 ceph_osdc_build_request(req, offset, snapc, vino.snap,
963 rc = ceph_osdc_start_request(&fsc->client->osdc, req, true);
969 wbc->nr_to_write -= locked_pages;
970 if (wbc->nr_to_write <= 0)
974 dout("pagevec_release on %d pages (%p)\n", (int)pvec.nr,
975 pvec.nr ? pvec.pages[0] : NULL);
976 pagevec_release(&pvec);
978 if (locked_pages && !done)
982 if (should_loop && !done) {
983 /* more to do; loop back to beginning of file */
984 dout("writepages looping back to beginning of file\n");
990 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
991 mapping->writeback_index = index;
995 ceph_osdc_put_request(req);
996 ceph_put_snap_context(snapc);
997 dout("writepages done, rc = %d\n", rc);
1004 * See if a given @snapc is either writeable, or already written.
1006 static int context_is_writeable_or_written(struct inode *inode,
1007 struct ceph_snap_context *snapc)
1009 struct ceph_snap_context *oldest = get_oldest_context(inode, NULL);
1010 int ret = !oldest || snapc->seq <= oldest->seq;
1012 ceph_put_snap_context(oldest);
1017 * We are only allowed to write into/dirty the page if the page is
1018 * clean, or already dirty within the same snap context.
1020 * called with page locked.
1021 * return success with page locked,
1022 * or any failure (incl -EAGAIN) with page unlocked.
1024 static int ceph_update_writeable_page(struct file *file,
1025 loff_t pos, unsigned len,
1028 struct inode *inode = file_inode(file);
1029 struct ceph_inode_info *ci = ceph_inode(inode);
1030 struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc;
1031 loff_t page_off = pos & PAGE_CACHE_MASK;
1032 int pos_in_page = pos & ~PAGE_CACHE_MASK;
1033 int end_in_page = pos_in_page + len;
1036 struct ceph_snap_context *snapc, *oldest;
1039 /* writepages currently holds page lock, but if we change that later, */
1040 wait_on_page_writeback(page);
1042 /* check snap context */
1043 BUG_ON(!ci->i_snap_realm);
1044 down_read(&mdsc->snap_rwsem);
1045 BUG_ON(!ci->i_snap_realm->cached_context);
1046 snapc = page_snap_context(page);
1047 if (snapc && snapc != ci->i_head_snapc) {
1049 * this page is already dirty in another (older) snap
1050 * context! is it writeable now?
1052 oldest = get_oldest_context(inode, NULL);
1053 up_read(&mdsc->snap_rwsem);
1055 if (snapc->seq > oldest->seq) {
1056 ceph_put_snap_context(oldest);
1057 dout(" page %p snapc %p not current or oldest\n",
1060 * queue for writeback, and wait for snapc to
1061 * be writeable or written
1063 snapc = ceph_get_snap_context(snapc);
1065 ceph_queue_writeback(inode);
1066 r = wait_event_interruptible(ci->i_cap_wq,
1067 context_is_writeable_or_written(inode, snapc));
1068 ceph_put_snap_context(snapc);
1069 if (r == -ERESTARTSYS)
1073 ceph_put_snap_context(oldest);
1075 /* yay, writeable, do it now (without dropping page lock) */
1076 dout(" page %p snapc %p not current, but oldest\n",
1078 if (!clear_page_dirty_for_io(page))
1080 r = writepage_nounlock(page, NULL);
1086 if (PageUptodate(page)) {
1087 dout(" page %p already uptodate\n", page);
1092 if (pos_in_page == 0 && len == PAGE_CACHE_SIZE)
1095 /* past end of file? */
1096 i_size = inode->i_size; /* caller holds i_mutex */
1098 if (page_off >= i_size ||
1099 (pos_in_page == 0 && (pos+len) >= i_size &&
1100 end_in_page - pos_in_page != PAGE_CACHE_SIZE)) {
1101 dout(" zeroing %p 0 - %d and %d - %d\n",
1102 page, pos_in_page, end_in_page, (int)PAGE_CACHE_SIZE);
1103 zero_user_segments(page,
1105 end_in_page, PAGE_CACHE_SIZE);
1109 /* we need to read it. */
1110 up_read(&mdsc->snap_rwsem);
1111 r = readpage_nounlock(file, page);
1121 * We are only allowed to write into/dirty the page if the page is
1122 * clean, or already dirty within the same snap context.
1124 static int ceph_write_begin(struct file *file, struct address_space *mapping,
1125 loff_t pos, unsigned len, unsigned flags,
1126 struct page **pagep, void **fsdata)
1128 struct inode *inode = file_inode(file);
1130 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
1135 page = grab_cache_page_write_begin(mapping, index, 0);
1140 dout("write_begin file %p inode %p page %p %d~%d\n", file,
1141 inode, page, (int)pos, (int)len);
1143 r = ceph_update_writeable_page(file, pos, len, page);
1144 } while (r == -EAGAIN);
1150 * we don't do anything in here that simple_write_end doesn't do
1151 * except adjust dirty page accounting and drop read lock on
1154 static int ceph_write_end(struct file *file, struct address_space *mapping,
1155 loff_t pos, unsigned len, unsigned copied,
1156 struct page *page, void *fsdata)
1158 struct inode *inode = file_inode(file);
1159 struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
1160 struct ceph_mds_client *mdsc = fsc->mdsc;
1161 unsigned from = pos & (PAGE_CACHE_SIZE - 1);
1164 dout("write_end file %p inode %p page %p %d~%d (%d)\n", file,
1165 inode, page, (int)pos, (int)copied, (int)len);
1167 /* zero the stale part of the page if we did a short copy */
1169 zero_user_segment(page, from+copied, len);
1171 /* did file size increase? */
1172 /* (no need for i_size_read(); we caller holds i_mutex */
1173 if (pos+copied > inode->i_size)
1174 check_cap = ceph_inode_set_size(inode, pos+copied);
1176 if (!PageUptodate(page))
1177 SetPageUptodate(page);
1179 set_page_dirty(page);
1182 up_read(&mdsc->snap_rwsem);
1183 page_cache_release(page);
1186 ceph_check_caps(ceph_inode(inode), CHECK_CAPS_AUTHONLY, NULL);
1192 * we set .direct_IO to indicate direct io is supported, but since we
1193 * intercept O_DIRECT reads and writes early, this function should
1196 static ssize_t ceph_direct_io(int rw, struct kiocb *iocb,
1197 struct iov_iter *iter,
1204 const struct address_space_operations ceph_aops = {
1205 .readpage = ceph_readpage,
1206 .readpages = ceph_readpages,
1207 .writepage = ceph_writepage,
1208 .writepages = ceph_writepages_start,
1209 .write_begin = ceph_write_begin,
1210 .write_end = ceph_write_end,
1211 .set_page_dirty = ceph_set_page_dirty,
1212 .invalidatepage = ceph_invalidatepage,
1213 .releasepage = ceph_releasepage,
1214 .direct_IO = ceph_direct_io,
1221 static int ceph_filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1223 struct inode *inode = file_inode(vma->vm_file);
1224 struct ceph_inode_info *ci = ceph_inode(inode);
1225 struct ceph_file_info *fi = vma->vm_file->private_data;
1226 struct page *pinned_page = NULL;
1227 loff_t off = vmf->pgoff << PAGE_CACHE_SHIFT;
1230 dout("filemap_fault %p %llx.%llx %llu~%zd trying to get caps\n",
1231 inode, ceph_vinop(inode), off, (size_t)PAGE_CACHE_SIZE);
1232 if (fi->fmode & CEPH_FILE_MODE_LAZY)
1233 want = CEPH_CAP_FILE_CACHE | CEPH_CAP_FILE_LAZYIO;
1235 want = CEPH_CAP_FILE_CACHE;
1238 ret = ceph_get_caps(ci, CEPH_CAP_FILE_RD, want,
1239 -1, &got, &pinned_page);
1242 if (ret != -ERESTARTSYS) {
1244 return VM_FAULT_SIGBUS;
1247 dout("filemap_fault %p %llu~%zd got cap refs on %s\n",
1248 inode, off, (size_t)PAGE_CACHE_SIZE, ceph_cap_string(got));
1250 if ((got & (CEPH_CAP_FILE_CACHE | CEPH_CAP_FILE_LAZYIO)) ||
1251 ci->i_inline_version == CEPH_INLINE_NONE)
1252 ret = filemap_fault(vma, vmf);
1256 dout("filemap_fault %p %llu~%zd dropping cap refs on %s ret %d\n",
1257 inode, off, (size_t)PAGE_CACHE_SIZE, ceph_cap_string(got), ret);
1259 page_cache_release(pinned_page);
1260 ceph_put_cap_refs(ci, got);
1265 /* read inline data */
1266 if (off >= PAGE_CACHE_SIZE) {
1267 /* does not support inline data > PAGE_SIZE */
1268 ret = VM_FAULT_SIGBUS;
1271 struct address_space *mapping = inode->i_mapping;
1272 struct page *page = find_or_create_page(mapping, 0,
1273 mapping_gfp_mask(mapping) &
1279 ret1 = __ceph_do_getattr(inode, page,
1280 CEPH_STAT_CAP_INLINE_DATA, true);
1281 if (ret1 < 0 || off >= i_size_read(inode)) {
1283 page_cache_release(page);
1284 ret = VM_FAULT_SIGBUS;
1287 if (ret1 < PAGE_CACHE_SIZE)
1288 zero_user_segment(page, ret1, PAGE_CACHE_SIZE);
1290 flush_dcache_page(page);
1291 SetPageUptodate(page);
1293 ret = VM_FAULT_MAJOR | VM_FAULT_LOCKED;
1296 dout("filemap_fault %p %llu~%zd read inline data ret %d\n",
1297 inode, off, (size_t)PAGE_CACHE_SIZE, ret);
1302 * Reuse write_begin here for simplicity.
1304 static int ceph_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
1306 struct inode *inode = file_inode(vma->vm_file);
1307 struct ceph_inode_info *ci = ceph_inode(inode);
1308 struct ceph_file_info *fi = vma->vm_file->private_data;
1309 struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc;
1310 struct page *page = vmf->page;
1311 loff_t off = page_offset(page);
1312 loff_t size = i_size_read(inode);
1316 if (ci->i_inline_version != CEPH_INLINE_NONE) {
1317 struct page *locked_page = NULL;
1322 ret = ceph_uninline_data(vma->vm_file, locked_page);
1324 unlock_page(locked_page);
1326 return VM_FAULT_SIGBUS;
1329 if (off + PAGE_CACHE_SIZE <= size)
1330 len = PAGE_CACHE_SIZE;
1332 len = size & ~PAGE_CACHE_MASK;
1334 dout("page_mkwrite %p %llx.%llx %llu~%zd getting caps i_size %llu\n",
1335 inode, ceph_vinop(inode), off, len, size);
1336 if (fi->fmode & CEPH_FILE_MODE_LAZY)
1337 want = CEPH_CAP_FILE_BUFFER | CEPH_CAP_FILE_LAZYIO;
1339 want = CEPH_CAP_FILE_BUFFER;
1342 ret = ceph_get_caps(ci, CEPH_CAP_FILE_WR, want, off + len,
1346 if (ret != -ERESTARTSYS) {
1348 return VM_FAULT_SIGBUS;
1351 dout("page_mkwrite %p %llu~%zd got cap refs on %s\n",
1352 inode, off, len, ceph_cap_string(got));
1354 /* Update time before taking page lock */
1355 file_update_time(vma->vm_file);
1359 ret = VM_FAULT_NOPAGE;
1361 (page->mapping != inode->i_mapping))
1364 ret = ceph_update_writeable_page(vma->vm_file, off, len, page);
1366 /* success. we'll keep the page locked. */
1367 set_page_dirty(page);
1368 up_read(&mdsc->snap_rwsem);
1369 ret = VM_FAULT_LOCKED;
1374 ret = VM_FAULT_SIGBUS;
1377 if (ret != VM_FAULT_LOCKED)
1379 if (ret == VM_FAULT_LOCKED ||
1380 ci->i_inline_version != CEPH_INLINE_NONE) {
1382 spin_lock(&ci->i_ceph_lock);
1383 ci->i_inline_version = CEPH_INLINE_NONE;
1384 dirty = __ceph_mark_dirty_caps(ci, CEPH_CAP_FILE_WR);
1385 spin_unlock(&ci->i_ceph_lock);
1387 __mark_inode_dirty(inode, dirty);
1390 dout("page_mkwrite %p %llu~%zd dropping cap refs on %s ret %d\n",
1391 inode, off, len, ceph_cap_string(got), ret);
1392 ceph_put_cap_refs(ci, got);
1397 void ceph_fill_inline_data(struct inode *inode, struct page *locked_page,
1398 char *data, size_t len)
1400 struct address_space *mapping = inode->i_mapping;
1406 if (i_size_read(inode) == 0)
1408 page = find_or_create_page(mapping, 0,
1409 mapping_gfp_mask(mapping) & ~__GFP_FS);
1412 if (PageUptodate(page)) {
1414 page_cache_release(page);
1419 dout("fill_inline_data %p %llx.%llx len %zu locked_page %p\n",
1420 inode, ceph_vinop(inode), len, locked_page);
1423 void *kaddr = kmap_atomic(page);
1424 memcpy(kaddr, data, len);
1425 kunmap_atomic(kaddr);
1428 if (page != locked_page) {
1429 if (len < PAGE_CACHE_SIZE)
1430 zero_user_segment(page, len, PAGE_CACHE_SIZE);
1432 flush_dcache_page(page);
1434 SetPageUptodate(page);
1436 page_cache_release(page);
1440 int ceph_uninline_data(struct file *filp, struct page *locked_page)
1442 struct inode *inode = file_inode(filp);
1443 struct ceph_inode_info *ci = ceph_inode(inode);
1444 struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
1445 struct ceph_osd_request *req;
1446 struct page *page = NULL;
1447 u64 len, inline_version;
1449 bool from_pagecache = false;
1451 spin_lock(&ci->i_ceph_lock);
1452 inline_version = ci->i_inline_version;
1453 spin_unlock(&ci->i_ceph_lock);
1455 dout("uninline_data %p %llx.%llx inline_version %llu\n",
1456 inode, ceph_vinop(inode), inline_version);
1458 if (inline_version == 1 || /* initial version, no data */
1459 inline_version == CEPH_INLINE_NONE)
1464 WARN_ON(!PageUptodate(page));
1465 } else if (ceph_caps_issued(ci) &
1466 (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) {
1467 page = find_get_page(inode->i_mapping, 0);
1469 if (PageUptodate(page)) {
1470 from_pagecache = true;
1473 page_cache_release(page);
1480 len = i_size_read(inode);
1481 if (len > PAGE_CACHE_SIZE)
1482 len = PAGE_CACHE_SIZE;
1484 page = __page_cache_alloc(GFP_NOFS);
1489 err = __ceph_do_getattr(inode, page,
1490 CEPH_STAT_CAP_INLINE_DATA, true);
1492 /* no inline data */
1493 if (err == -ENODATA)
1500 req = ceph_osdc_new_request(&fsc->client->osdc, &ci->i_layout,
1501 ceph_vino(inode), 0, &len, 0, 1,
1503 CEPH_OSD_FLAG_ONDISK | CEPH_OSD_FLAG_WRITE,
1504 ci->i_snap_realm->cached_context,
1511 ceph_osdc_build_request(req, 0, NULL, CEPH_NOSNAP, &inode->i_mtime);
1512 err = ceph_osdc_start_request(&fsc->client->osdc, req, false);
1514 err = ceph_osdc_wait_request(&fsc->client->osdc, req);
1515 ceph_osdc_put_request(req);
1519 req = ceph_osdc_new_request(&fsc->client->osdc, &ci->i_layout,
1520 ceph_vino(inode), 0, &len, 1, 3,
1522 CEPH_OSD_FLAG_ONDISK | CEPH_OSD_FLAG_WRITE,
1523 ci->i_snap_realm->cached_context,
1524 ci->i_truncate_seq, ci->i_truncate_size,
1531 osd_req_op_extent_osd_data_pages(req, 1, &page, len, 0, false, false);
1533 err = osd_req_op_xattr_init(req, 0, CEPH_OSD_OP_CMPXATTR,
1534 "inline_version", &inline_version,
1535 sizeof(inline_version),
1536 CEPH_OSD_CMPXATTR_OP_GT,
1537 CEPH_OSD_CMPXATTR_MODE_U64);
1541 err = osd_req_op_xattr_init(req, 2, CEPH_OSD_OP_SETXATTR,
1542 "inline_version", &inline_version,
1543 sizeof(inline_version), 0, 0);
1547 ceph_osdc_build_request(req, 0, NULL, CEPH_NOSNAP, &inode->i_mtime);
1548 err = ceph_osdc_start_request(&fsc->client->osdc, req, false);
1550 err = ceph_osdc_wait_request(&fsc->client->osdc, req);
1552 ceph_osdc_put_request(req);
1553 if (err == -ECANCELED)
1556 if (page && page != locked_page) {
1557 if (from_pagecache) {
1559 page_cache_release(page);
1561 __free_pages(page, 0);
1564 dout("uninline_data %p %llx.%llx inline_version %llu = %d\n",
1565 inode, ceph_vinop(inode), inline_version, err);
1569 static struct vm_operations_struct ceph_vmops = {
1570 .fault = ceph_filemap_fault,
1571 .page_mkwrite = ceph_page_mkwrite,
1572 .remap_pages = generic_file_remap_pages,
1575 int ceph_mmap(struct file *file, struct vm_area_struct *vma)
1577 struct address_space *mapping = file->f_mapping;
1579 if (!mapping->a_ops->readpage)
1581 file_accessed(file);
1582 vma->vm_ops = &ceph_vmops;