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-rw-r--r--fs/ceph/addr.c1194
1 files changed, 1194 insertions, 0 deletions
diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
new file mode 100644
index 000000000000..ce8ef6107727
--- /dev/null
+++ b/fs/ceph/addr.c
@@ -0,0 +1,1194 @@
1#include "ceph_debug.h"
2
3#include <linux/backing-dev.h>
4#include <linux/fs.h>
5#include <linux/mm.h>
6#include <linux/pagemap.h>
7#include <linux/writeback.h> /* generic_writepages */
8#include <linux/pagevec.h>
9#include <linux/task_io_accounting_ops.h>
10
11#include "super.h"
12#include "osd_client.h"
13
14/*
15 * Ceph address space ops.
16 *
17 * There are a few funny things going on here.
18 *
19 * The page->private field is used to reference a struct
20 * ceph_snap_context for _every_ dirty page. This indicates which
21 * snapshot the page was logically dirtied in, and thus which snap
22 * context needs to be associated with the osd write during writeback.
23 *
24 * Similarly, struct ceph_inode_info maintains a set of counters to
25 * count dirty pages on the inode. In the absense of snapshots,
26 * i_wrbuffer_ref == i_wrbuffer_ref_head == the dirty page count.
27 *
28 * When a snapshot is taken (that is, when the client receives
29 * notification that a snapshot was taken), each inode with caps and
30 * with dirty pages (dirty pages implies there is a cap) gets a new
31 * ceph_cap_snap in the i_cap_snaps list (which is sorted in ascending
32 * order, new snaps go to the tail). The i_wrbuffer_ref_head count is
33 * moved to capsnap->dirty. (Unless a sync write is currently in
34 * progress. In that case, the capsnap is said to be "pending", new
35 * writes cannot start, and the capsnap isn't "finalized" until the
36 * write completes (or fails) and a final size/mtime for the inode for
37 * that snap can be settled upon.) i_wrbuffer_ref_head is reset to 0.
38 *
39 * On writeback, we must submit writes to the osd IN SNAP ORDER. So,
40 * we look for the first capsnap in i_cap_snaps and write out pages in
41 * that snap context _only_. Then we move on to the next capsnap,
42 * eventually reaching the "live" or "head" context (i.e., pages that
43 * are not yet snapped) and are writing the most recently dirtied
44 * pages.
45 *
46 * Invalidate and so forth must take care to ensure the dirty page
47 * accounting is preserved.
48 */
49
50#define CONGESTION_ON_THRESH(congestion_kb) (congestion_kb >> (PAGE_SHIFT-10))
51#define CONGESTION_OFF_THRESH(congestion_kb) \
52 (CONGESTION_ON_THRESH(congestion_kb) - \
53 (CONGESTION_ON_THRESH(congestion_kb) >> 2))
54
55
56
57/*
58 * Dirty a page. Optimistically adjust accounting, on the assumption
59 * that we won't race with invalidate. If we do, readjust.
60 */
61static int ceph_set_page_dirty(struct page *page)
62{
63 struct address_space *mapping = page->mapping;
64 struct inode *inode;
65 struct ceph_inode_info *ci;
66 int undo = 0;
67 struct ceph_snap_context *snapc;
68
69 if (unlikely(!mapping))
70 return !TestSetPageDirty(page);
71
72 if (TestSetPageDirty(page)) {
73 dout("%p set_page_dirty %p idx %lu -- already dirty\n",
74 mapping->host, page, page->index);
75 return 0;
76 }
77
78 inode = mapping->host;
79 ci = ceph_inode(inode);
80
81 /*
82 * Note that we're grabbing a snapc ref here without holding
83 * any locks!
84 */
85 snapc = ceph_get_snap_context(ci->i_snap_realm->cached_context);
86
87 /* dirty the head */
88 spin_lock(&inode->i_lock);
89 if (ci->i_wrbuffer_ref_head == 0)
90 ci->i_head_snapc = ceph_get_snap_context(snapc);
91 ++ci->i_wrbuffer_ref_head;
92 if (ci->i_wrbuffer_ref == 0)
93 igrab(inode);
94 ++ci->i_wrbuffer_ref;
95 dout("%p set_page_dirty %p idx %lu head %d/%d -> %d/%d "
96 "snapc %p seq %lld (%d snaps)\n",
97 mapping->host, page, page->index,
98 ci->i_wrbuffer_ref-1, ci->i_wrbuffer_ref_head-1,
99 ci->i_wrbuffer_ref, ci->i_wrbuffer_ref_head,
100 snapc, snapc->seq, snapc->num_snaps);
101 spin_unlock(&inode->i_lock);
102
103 /* now adjust page */
104 spin_lock_irq(&mapping->tree_lock);
105 if (page->mapping) { /* Race with truncate? */
106 WARN_ON_ONCE(!PageUptodate(page));
107
108 if (mapping_cap_account_dirty(mapping)) {
109 __inc_zone_page_state(page, NR_FILE_DIRTY);
110 __inc_bdi_stat(mapping->backing_dev_info,
111 BDI_RECLAIMABLE);
112 task_io_account_write(PAGE_CACHE_SIZE);
113 }
114 radix_tree_tag_set(&mapping->page_tree,
115 page_index(page), PAGECACHE_TAG_DIRTY);
116
117 /*
118 * Reference snap context in page->private. Also set
119 * PagePrivate so that we get invalidatepage callback.
120 */
121 page->private = (unsigned long)snapc;
122 SetPagePrivate(page);
123 } else {
124 dout("ANON set_page_dirty %p (raced truncate?)\n", page);
125 undo = 1;
126 }
127
128 spin_unlock_irq(&mapping->tree_lock);
129
130 if (undo)
131 /* whoops, we failed to dirty the page */
132 ceph_put_wrbuffer_cap_refs(ci, 1, snapc);
133
134 __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
135
136 BUG_ON(!PageDirty(page));
137 return 1;
138}
139
140/*
141 * If we are truncating the full page (i.e. offset == 0), adjust the
142 * dirty page counters appropriately. Only called if there is private
143 * data on the page.
144 */
145static void ceph_invalidatepage(struct page *page, unsigned long offset)
146{
147 struct inode *inode;
148 struct ceph_inode_info *ci;
149 struct ceph_snap_context *snapc = (void *)page->private;
150
151 BUG_ON(!PageLocked(page));
152 BUG_ON(!page->private);
153 BUG_ON(!PagePrivate(page));
154 BUG_ON(!page->mapping);
155
156 inode = page->mapping->host;
157
158 /*
159 * We can get non-dirty pages here due to races between
160 * set_page_dirty and truncate_complete_page; just spit out a
161 * warning, in case we end up with accounting problems later.
162 */
163 if (!PageDirty(page))
164 pr_err("%p invalidatepage %p page not dirty\n", inode, page);
165
166 if (offset == 0)
167 ClearPageChecked(page);
168
169 ci = ceph_inode(inode);
170 if (offset == 0) {
171 dout("%p invalidatepage %p idx %lu full dirty page %lu\n",
172 inode, page, page->index, offset);
173 ceph_put_wrbuffer_cap_refs(ci, 1, snapc);
174 ceph_put_snap_context(snapc);
175 page->private = 0;
176 ClearPagePrivate(page);
177 } else {
178 dout("%p invalidatepage %p idx %lu partial dirty page\n",
179 inode, page, page->index);
180 }
181}
182
183/* just a sanity check */
184static int ceph_releasepage(struct page *page, gfp_t g)
185{
186 struct inode *inode = page->mapping ? page->mapping->host : NULL;
187 dout("%p releasepage %p idx %lu\n", inode, page, page->index);
188 WARN_ON(PageDirty(page));
189 WARN_ON(page->private);
190 WARN_ON(PagePrivate(page));
191 return 0;
192}
193
194/*
195 * read a single page, without unlocking it.
196 */
197static int readpage_nounlock(struct file *filp, struct page *page)
198{
199 struct inode *inode = filp->f_dentry->d_inode;
200 struct ceph_inode_info *ci = ceph_inode(inode);
201 struct ceph_osd_client *osdc = &ceph_inode_to_client(inode)->osdc;
202 int err = 0;
203 u64 len = PAGE_CACHE_SIZE;
204
205 dout("readpage inode %p file %p page %p index %lu\n",
206 inode, filp, page, page->index);
207 err = ceph_osdc_readpages(osdc, ceph_vino(inode), &ci->i_layout,
208 page->index << PAGE_CACHE_SHIFT, &len,
209 ci->i_truncate_seq, ci->i_truncate_size,
210 &page, 1);
211 if (err == -ENOENT)
212 err = 0;
213 if (err < 0) {
214 SetPageError(page);
215 goto out;
216 } else if (err < PAGE_CACHE_SIZE) {
217 /* zero fill remainder of page */
218 zero_user_segment(page, err, PAGE_CACHE_SIZE);
219 }
220 SetPageUptodate(page);
221
222out:
223 return err < 0 ? err : 0;
224}
225
226static int ceph_readpage(struct file *filp, struct page *page)
227{
228 int r = readpage_nounlock(filp, page);
229 unlock_page(page);
230 return r;
231}
232
233/*
234 * Build a vector of contiguous pages from the provided page list.
235 */
236static struct page **page_vector_from_list(struct list_head *page_list,
237 unsigned *nr_pages)
238{
239 struct page **pages;
240 struct page *page;
241 int next_index, contig_pages = 0;
242
243 /* build page vector */
244 pages = kmalloc(sizeof(*pages) * *nr_pages, GFP_NOFS);
245 if (!pages)
246 return ERR_PTR(-ENOMEM);
247
248 BUG_ON(list_empty(page_list));
249 next_index = list_entry(page_list->prev, struct page, lru)->index;
250 list_for_each_entry_reverse(page, page_list, lru) {
251 if (page->index == next_index) {
252 dout("readpages page %d %p\n", contig_pages, page);
253 pages[contig_pages] = page;
254 contig_pages++;
255 next_index++;
256 } else {
257 break;
258 }
259 }
260 *nr_pages = contig_pages;
261 return pages;
262}
263
264/*
265 * Read multiple pages. Leave pages we don't read + unlock in page_list;
266 * the caller (VM) cleans them up.
267 */
268static int ceph_readpages(struct file *file, struct address_space *mapping,
269 struct list_head *page_list, unsigned nr_pages)
270{
271 struct inode *inode = file->f_dentry->d_inode;
272 struct ceph_inode_info *ci = ceph_inode(inode);
273 struct ceph_osd_client *osdc = &ceph_inode_to_client(inode)->osdc;
274 int rc = 0;
275 struct page **pages;
276 struct pagevec pvec;
277 loff_t offset;
278 u64 len;
279
280 dout("readpages %p file %p nr_pages %d\n",
281 inode, file, nr_pages);
282
283 pages = page_vector_from_list(page_list, &nr_pages);
284 if (IS_ERR(pages))
285 return PTR_ERR(pages);
286
287 /* guess read extent */
288 offset = pages[0]->index << PAGE_CACHE_SHIFT;
289 len = nr_pages << PAGE_CACHE_SHIFT;
290 rc = ceph_osdc_readpages(osdc, ceph_vino(inode), &ci->i_layout,
291 offset, &len,
292 ci->i_truncate_seq, ci->i_truncate_size,
293 pages, nr_pages);
294 if (rc == -ENOENT)
295 rc = 0;
296 if (rc < 0)
297 goto out;
298
299 /* set uptodate and add to lru in pagevec-sized chunks */
300 pagevec_init(&pvec, 0);
301 for (; !list_empty(page_list) && len > 0;
302 rc -= PAGE_CACHE_SIZE, len -= PAGE_CACHE_SIZE) {
303 struct page *page =
304 list_entry(page_list->prev, struct page, lru);
305
306 list_del(&page->lru);
307
308 if (rc < (int)PAGE_CACHE_SIZE) {
309 /* zero (remainder of) page */
310 int s = rc < 0 ? 0 : rc;
311 zero_user_segment(page, s, PAGE_CACHE_SIZE);
312 }
313
314 if (add_to_page_cache(page, mapping, page->index, GFP_NOFS)) {
315 page_cache_release(page);
316 dout("readpages %p add_to_page_cache failed %p\n",
317 inode, page);
318 continue;
319 }
320 dout("readpages %p adding %p idx %lu\n", inode, page,
321 page->index);
322 flush_dcache_page(page);
323 SetPageUptodate(page);
324 unlock_page(page);
325 if (pagevec_add(&pvec, page) == 0)
326 pagevec_lru_add_file(&pvec); /* add to lru */
327 }
328 pagevec_lru_add_file(&pvec);
329 rc = 0;
330
331out:
332 kfree(pages);
333 return rc;
334}
335
336/*
337 * Get ref for the oldest snapc for an inode with dirty data... that is, the
338 * only snap context we are allowed to write back.
339 *
340 * Caller holds i_lock.
341 */
342static struct ceph_snap_context *__get_oldest_context(struct inode *inode,
343 u64 *snap_size)
344{
345 struct ceph_inode_info *ci = ceph_inode(inode);
346 struct ceph_snap_context *snapc = NULL;
347 struct ceph_cap_snap *capsnap = NULL;
348
349 list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) {
350 dout(" cap_snap %p snapc %p has %d dirty pages\n", capsnap,
351 capsnap->context, capsnap->dirty_pages);
352 if (capsnap->dirty_pages) {
353 snapc = ceph_get_snap_context(capsnap->context);
354 if (snap_size)
355 *snap_size = capsnap->size;
356 break;
357 }
358 }
359 if (!snapc && ci->i_snap_realm) {
360 snapc = ceph_get_snap_context(ci->i_snap_realm->cached_context);
361 dout(" head snapc %p has %d dirty pages\n",
362 snapc, ci->i_wrbuffer_ref_head);
363 }
364 return snapc;
365}
366
367static struct ceph_snap_context *get_oldest_context(struct inode *inode,
368 u64 *snap_size)
369{
370 struct ceph_snap_context *snapc = NULL;
371
372 spin_lock(&inode->i_lock);
373 snapc = __get_oldest_context(inode, snap_size);
374 spin_unlock(&inode->i_lock);
375 return snapc;
376}
377
378/*
379 * Write a single page, but leave the page locked.
380 *
381 * If we get a write error, set the page error bit, but still adjust the
382 * dirty page accounting (i.e., page is no longer dirty).
383 */
384static int writepage_nounlock(struct page *page, struct writeback_control *wbc)
385{
386 struct inode *inode;
387 struct ceph_inode_info *ci;
388 struct ceph_client *client;
389 struct ceph_osd_client *osdc;
390 loff_t page_off = page->index << PAGE_CACHE_SHIFT;
391 int len = PAGE_CACHE_SIZE;
392 loff_t i_size;
393 int err = 0;
394 struct ceph_snap_context *snapc;
395 u64 snap_size = 0;
396 long writeback_stat;
397
398 dout("writepage %p idx %lu\n", page, page->index);
399
400 if (!page->mapping || !page->mapping->host) {
401 dout("writepage %p - no mapping\n", page);
402 return -EFAULT;
403 }
404 inode = page->mapping->host;
405 ci = ceph_inode(inode);
406 client = ceph_inode_to_client(inode);
407 osdc = &client->osdc;
408
409 /* verify this is a writeable snap context */
410 snapc = (void *)page->private;
411 if (snapc == NULL) {
412 dout("writepage %p page %p not dirty?\n", inode, page);
413 goto out;
414 }
415 if (snapc != get_oldest_context(inode, &snap_size)) {
416 dout("writepage %p page %p snapc %p not writeable - noop\n",
417 inode, page, (void *)page->private);
418 /* we should only noop if called by kswapd */
419 WARN_ON((current->flags & PF_MEMALLOC) == 0);
420 goto out;
421 }
422
423 /* is this a partial page at end of file? */
424 if (snap_size)
425 i_size = snap_size;
426 else
427 i_size = i_size_read(inode);
428 if (i_size < page_off + len)
429 len = i_size - page_off;
430
431 dout("writepage %p page %p index %lu on %llu~%u\n",
432 inode, page, page->index, page_off, len);
433
434 writeback_stat = atomic_long_inc_return(&client->writeback_count);
435 if (writeback_stat >
436 CONGESTION_ON_THRESH(client->mount_args->congestion_kb))
437 set_bdi_congested(&client->backing_dev_info, BLK_RW_ASYNC);
438
439 set_page_writeback(page);
440 err = ceph_osdc_writepages(osdc, ceph_vino(inode),
441 &ci->i_layout, snapc,
442 page_off, len,
443 ci->i_truncate_seq, ci->i_truncate_size,
444 &inode->i_mtime,
445 &page, 1, 0, 0, true);
446 if (err < 0) {
447 dout("writepage setting page/mapping error %d %p\n", err, page);
448 SetPageError(page);
449 mapping_set_error(&inode->i_data, err);
450 if (wbc)
451 wbc->pages_skipped++;
452 } else {
453 dout("writepage cleaned page %p\n", page);
454 err = 0; /* vfs expects us to return 0 */
455 }
456 page->private = 0;
457 ClearPagePrivate(page);
458 end_page_writeback(page);
459 ceph_put_wrbuffer_cap_refs(ci, 1, snapc);
460 ceph_put_snap_context(snapc);
461out:
462 return err;
463}
464
465static int ceph_writepage(struct page *page, struct writeback_control *wbc)
466{
467 int err;
468 struct inode *inode = page->mapping->host;
469 BUG_ON(!inode);
470 igrab(inode);
471 err = writepage_nounlock(page, wbc);
472 unlock_page(page);
473 iput(inode);
474 return err;
475}
476
477
478/*
479 * lame release_pages helper. release_pages() isn't exported to
480 * modules.
481 */
482static void ceph_release_pages(struct page **pages, int num)
483{
484 struct pagevec pvec;
485 int i;
486
487 pagevec_init(&pvec, 0);
488 for (i = 0; i < num; i++) {
489 if (pagevec_add(&pvec, pages[i]) == 0)
490 pagevec_release(&pvec);
491 }
492 pagevec_release(&pvec);
493}
494
495
496/*
497 * async writeback completion handler.
498 *
499 * If we get an error, set the mapping error bit, but not the individual
500 * page error bits.
501 */
502static void writepages_finish(struct ceph_osd_request *req,
503 struct ceph_msg *msg)
504{
505 struct inode *inode = req->r_inode;
506 struct ceph_osd_reply_head *replyhead;
507 struct ceph_osd_op *op;
508 struct ceph_inode_info *ci = ceph_inode(inode);
509 unsigned wrote;
510 struct page *page;
511 int i;
512 struct ceph_snap_context *snapc = req->r_snapc;
513 struct address_space *mapping = inode->i_mapping;
514 struct writeback_control *wbc = req->r_wbc;
515 __s32 rc = -EIO;
516 u64 bytes = 0;
517 struct ceph_client *client = ceph_inode_to_client(inode);
518 long writeback_stat;
519 unsigned issued = __ceph_caps_issued(ci, NULL);
520
521 /* parse reply */
522 replyhead = msg->front.iov_base;
523 WARN_ON(le32_to_cpu(replyhead->num_ops) == 0);
524 op = (void *)(replyhead + 1);
525 rc = le32_to_cpu(replyhead->result);
526 bytes = le64_to_cpu(op->extent.length);
527
528 if (rc >= 0) {
529 /*
530 * Assume we wrote the pages we originally sent. The
531 * osd might reply with fewer pages if our writeback
532 * raced with a truncation and was adjusted at the osd,
533 * so don't believe the reply.
534 */
535 wrote = req->r_num_pages;
536 } else {
537 wrote = 0;
538 mapping_set_error(mapping, rc);
539 }
540 dout("writepages_finish %p rc %d bytes %llu wrote %d (pages)\n",
541 inode, rc, bytes, wrote);
542
543 /* clean all pages */
544 for (i = 0; i < req->r_num_pages; i++) {
545 page = req->r_pages[i];
546 BUG_ON(!page);
547 WARN_ON(!PageUptodate(page));
548
549 writeback_stat =
550 atomic_long_dec_return(&client->writeback_count);
551 if (writeback_stat <
552 CONGESTION_OFF_THRESH(client->mount_args->congestion_kb))
553 clear_bdi_congested(&client->backing_dev_info,
554 BLK_RW_ASYNC);
555
556 if (i >= wrote) {
557 dout("inode %p skipping page %p\n", inode, page);
558 wbc->pages_skipped++;
559 }
560 page->private = 0;
561 ClearPagePrivate(page);
562 ceph_put_snap_context(snapc);
563 dout("unlocking %d %p\n", i, page);
564 end_page_writeback(page);
565
566 /*
567 * We lost the cache cap, need to truncate the page before
568 * it is unlocked, otherwise we'd truncate it later in the
569 * page truncation thread, possibly losing some data that
570 * raced its way in
571 */
572 if ((issued & CEPH_CAP_FILE_CACHE) == 0)
573 generic_error_remove_page(inode->i_mapping, page);
574
575 unlock_page(page);
576 }
577 dout("%p wrote+cleaned %d pages\n", inode, wrote);
578 ceph_put_wrbuffer_cap_refs(ci, req->r_num_pages, snapc);
579
580 ceph_release_pages(req->r_pages, req->r_num_pages);
581 if (req->r_pages_from_pool)
582 mempool_free(req->r_pages,
583 ceph_client(inode->i_sb)->wb_pagevec_pool);
584 else
585 kfree(req->r_pages);
586 ceph_osdc_put_request(req);
587}
588
589/*
590 * allocate a page vec, either directly, or if necessary, via a the
591 * mempool. we avoid the mempool if we can because req->r_num_pages
592 * may be less than the maximum write size.
593 */
594static void alloc_page_vec(struct ceph_client *client,
595 struct ceph_osd_request *req)
596{
597 req->r_pages = kmalloc(sizeof(struct page *) * req->r_num_pages,
598 GFP_NOFS);
599 if (!req->r_pages) {
600 req->r_pages = mempool_alloc(client->wb_pagevec_pool, GFP_NOFS);
601 req->r_pages_from_pool = 1;
602 WARN_ON(!req->r_pages);
603 }
604}
605
606/*
607 * initiate async writeback
608 */
609static int ceph_writepages_start(struct address_space *mapping,
610 struct writeback_control *wbc)
611{
612 struct inode *inode = mapping->host;
613 struct backing_dev_info *bdi = mapping->backing_dev_info;
614 struct ceph_inode_info *ci = ceph_inode(inode);
615 struct ceph_client *client;
616 pgoff_t index, start, end;
617 int range_whole = 0;
618 int should_loop = 1;
619 pgoff_t max_pages = 0, max_pages_ever = 0;
620 struct ceph_snap_context *snapc = NULL, *last_snapc = NULL;
621 struct pagevec pvec;
622 int done = 0;
623 int rc = 0;
624 unsigned wsize = 1 << inode->i_blkbits;
625 struct ceph_osd_request *req = NULL;
626 int do_sync;
627 u64 snap_size = 0;
628
629 /*
630 * Include a 'sync' in the OSD request if this is a data
631 * integrity write (e.g., O_SYNC write or fsync()), or if our
632 * cap is being revoked.
633 */
634 do_sync = wbc->sync_mode == WB_SYNC_ALL;
635 if (ceph_caps_revoking(ci, CEPH_CAP_FILE_BUFFER))
636 do_sync = 1;
637 dout("writepages_start %p dosync=%d (mode=%s)\n",
638 inode, do_sync,
639 wbc->sync_mode == WB_SYNC_NONE ? "NONE" :
640 (wbc->sync_mode == WB_SYNC_ALL ? "ALL" : "HOLD"));
641
642 client = ceph_inode_to_client(inode);
643 if (client->mount_state == CEPH_MOUNT_SHUTDOWN) {
644 pr_warning("writepage_start %p on forced umount\n", inode);
645 return -EIO; /* we're in a forced umount, don't write! */
646 }
647 if (client->mount_args->wsize && client->mount_args->wsize < wsize)
648 wsize = client->mount_args->wsize;
649 if (wsize < PAGE_CACHE_SIZE)
650 wsize = PAGE_CACHE_SIZE;
651 max_pages_ever = wsize >> PAGE_CACHE_SHIFT;
652
653 pagevec_init(&pvec, 0);
654
655 /* ?? */
656 if (wbc->nonblocking && bdi_write_congested(bdi)) {
657 dout(" writepages congested\n");
658 wbc->encountered_congestion = 1;
659 goto out_final;
660 }
661
662 /* where to start/end? */
663 if (wbc->range_cyclic) {
664 start = mapping->writeback_index; /* Start from prev offset */
665 end = -1;
666 dout(" cyclic, start at %lu\n", start);
667 } else {
668 start = wbc->range_start >> PAGE_CACHE_SHIFT;
669 end = wbc->range_end >> PAGE_CACHE_SHIFT;
670 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
671 range_whole = 1;
672 should_loop = 0;
673 dout(" not cyclic, %lu to %lu\n", start, end);
674 }
675 index = start;
676
677retry:
678 /* find oldest snap context with dirty data */
679 ceph_put_snap_context(snapc);
680 snapc = get_oldest_context(inode, &snap_size);
681 if (!snapc) {
682 /* hmm, why does writepages get called when there
683 is no dirty data? */
684 dout(" no snap context with dirty data?\n");
685 goto out;
686 }
687 dout(" oldest snapc is %p seq %lld (%d snaps)\n",
688 snapc, snapc->seq, snapc->num_snaps);
689 if (last_snapc && snapc != last_snapc) {
690 /* if we switched to a newer snapc, restart our scan at the
691 * start of the original file range. */
692 dout(" snapc differs from last pass, restarting at %lu\n",
693 index);
694 index = start;
695 }
696 last_snapc = snapc;
697
698 while (!done && index <= end) {
699 unsigned i;
700 int first;
701 pgoff_t next;
702 int pvec_pages, locked_pages;
703 struct page *page;
704 int want;
705 u64 offset, len;
706 struct ceph_osd_request_head *reqhead;
707 struct ceph_osd_op *op;
708 long writeback_stat;
709
710 next = 0;
711 locked_pages = 0;
712 max_pages = max_pages_ever;
713
714get_more_pages:
715 first = -1;
716 want = min(end - index,
717 min((pgoff_t)PAGEVEC_SIZE,
718 max_pages - (pgoff_t)locked_pages) - 1)
719 + 1;
720 pvec_pages = pagevec_lookup_tag(&pvec, mapping, &index,
721 PAGECACHE_TAG_DIRTY,
722 want);
723 dout("pagevec_lookup_tag got %d\n", pvec_pages);
724 if (!pvec_pages && !locked_pages)
725 break;
726 for (i = 0; i < pvec_pages && locked_pages < max_pages; i++) {
727 page = pvec.pages[i];
728 dout("? %p idx %lu\n", page, page->index);
729 if (locked_pages == 0)
730 lock_page(page); /* first page */
731 else if (!trylock_page(page))
732 break;
733
734 /* only dirty pages, or our accounting breaks */
735 if (unlikely(!PageDirty(page)) ||
736 unlikely(page->mapping != mapping)) {
737 dout("!dirty or !mapping %p\n", page);
738 unlock_page(page);
739 break;
740 }
741 if (!wbc->range_cyclic && page->index > end) {
742 dout("end of range %p\n", page);
743 done = 1;
744 unlock_page(page);
745 break;
746 }
747 if (next && (page->index != next)) {
748 dout("not consecutive %p\n", page);
749 unlock_page(page);
750 break;
751 }
752 if (wbc->sync_mode != WB_SYNC_NONE) {
753 dout("waiting on writeback %p\n", page);
754 wait_on_page_writeback(page);
755 }
756 if ((snap_size && page_offset(page) > snap_size) ||
757 (!snap_size &&
758 page_offset(page) > i_size_read(inode))) {
759 dout("%p page eof %llu\n", page, snap_size ?
760 snap_size : i_size_read(inode));
761 done = 1;
762 unlock_page(page);
763 break;
764 }
765 if (PageWriteback(page)) {
766 dout("%p under writeback\n", page);
767 unlock_page(page);
768 break;
769 }
770
771 /* only if matching snap context */
772 if (snapc != (void *)page->private) {
773 dout("page snapc %p != oldest %p\n",
774 (void *)page->private, snapc);
775 unlock_page(page);
776 if (!locked_pages)
777 continue; /* keep looking for snap */
778 break;
779 }
780
781 if (!clear_page_dirty_for_io(page)) {
782 dout("%p !clear_page_dirty_for_io\n", page);
783 unlock_page(page);
784 break;
785 }
786
787 /* ok */
788 if (locked_pages == 0) {
789 /* prepare async write request */
790 offset = page->index << PAGE_CACHE_SHIFT;
791 len = wsize;
792 req = ceph_osdc_new_request(&client->osdc,
793 &ci->i_layout,
794 ceph_vino(inode),
795 offset, &len,
796 CEPH_OSD_OP_WRITE,
797 CEPH_OSD_FLAG_WRITE |
798 CEPH_OSD_FLAG_ONDISK,
799 snapc, do_sync,
800 ci->i_truncate_seq,
801 ci->i_truncate_size,
802 &inode->i_mtime, true, 1);
803 max_pages = req->r_num_pages;
804
805 alloc_page_vec(client, req);
806 req->r_callback = writepages_finish;
807 req->r_inode = inode;
808 req->r_wbc = wbc;
809 }
810
811 /* note position of first page in pvec */
812 if (first < 0)
813 first = i;
814 dout("%p will write page %p idx %lu\n",
815 inode, page, page->index);
816
817 writeback_stat = atomic_long_inc_return(&client->writeback_count);
818 if (writeback_stat > CONGESTION_ON_THRESH(client->mount_args->congestion_kb)) {
819 set_bdi_congested(&client->backing_dev_info, BLK_RW_ASYNC);
820 }
821
822 set_page_writeback(page);
823 req->r_pages[locked_pages] = page;
824 locked_pages++;
825 next = page->index + 1;
826 }
827
828 /* did we get anything? */
829 if (!locked_pages)
830 goto release_pvec_pages;
831 if (i) {
832 int j;
833 BUG_ON(!locked_pages || first < 0);
834
835 if (pvec_pages && i == pvec_pages &&
836 locked_pages < max_pages) {
837 dout("reached end pvec, trying for more\n");
838 pagevec_reinit(&pvec);
839 goto get_more_pages;
840 }
841
842 /* shift unused pages over in the pvec... we
843 * will need to release them below. */
844 for (j = i; j < pvec_pages; j++) {
845 dout(" pvec leftover page %p\n",
846 pvec.pages[j]);
847 pvec.pages[j-i+first] = pvec.pages[j];
848 }
849 pvec.nr -= i-first;
850 }
851
852 /* submit the write */
853 offset = req->r_pages[0]->index << PAGE_CACHE_SHIFT;
854 len = min((snap_size ? snap_size : i_size_read(inode)) - offset,
855 (u64)locked_pages << PAGE_CACHE_SHIFT);
856 dout("writepages got %d pages at %llu~%llu\n",
857 locked_pages, offset, len);
858
859 /* revise final length, page count */
860 req->r_num_pages = locked_pages;
861 reqhead = req->r_request->front.iov_base;
862 op = (void *)(reqhead + 1);
863 op->extent.length = cpu_to_le64(len);
864 op->payload_len = cpu_to_le32(len);
865 req->r_request->hdr.data_len = cpu_to_le32(len);
866
867 ceph_osdc_start_request(&client->osdc, req, true);
868 req = NULL;
869
870 /* continue? */
871 index = next;
872 wbc->nr_to_write -= locked_pages;
873 if (wbc->nr_to_write <= 0)
874 done = 1;
875
876release_pvec_pages:
877 dout("pagevec_release on %d pages (%p)\n", (int)pvec.nr,
878 pvec.nr ? pvec.pages[0] : NULL);
879 pagevec_release(&pvec);
880
881 if (locked_pages && !done)
882 goto retry;
883 }
884
885 if (should_loop && !done) {
886 /* more to do; loop back to beginning of file */
887 dout("writepages looping back to beginning of file\n");
888 should_loop = 0;
889 index = 0;
890 goto retry;
891 }
892
893 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
894 mapping->writeback_index = index;
895
896out:
897 if (req)
898 ceph_osdc_put_request(req);
899 if (rc > 0)
900 rc = 0; /* vfs expects us to return 0 */
901 ceph_put_snap_context(snapc);
902 dout("writepages done, rc = %d\n", rc);
903out_final:
904 return rc;
905}
906
907
908
909/*
910 * See if a given @snapc is either writeable, or already written.
911 */
912static int context_is_writeable_or_written(struct inode *inode,
913 struct ceph_snap_context *snapc)
914{
915 struct ceph_snap_context *oldest = get_oldest_context(inode, NULL);
916 return !oldest || snapc->seq <= oldest->seq;
917}
918
919/*
920 * We are only allowed to write into/dirty the page if the page is
921 * clean, or already dirty within the same snap context.
922 *
923 * called with page locked.
924 * return success with page locked,
925 * or any failure (incl -EAGAIN) with page unlocked.
926 */
927static int ceph_update_writeable_page(struct file *file,
928 loff_t pos, unsigned len,
929 struct page *page)
930{
931 struct inode *inode = file->f_dentry->d_inode;
932 struct ceph_inode_info *ci = ceph_inode(inode);
933 struct ceph_mds_client *mdsc = &ceph_inode_to_client(inode)->mdsc;
934 loff_t page_off = pos & PAGE_CACHE_MASK;
935 int pos_in_page = pos & ~PAGE_CACHE_MASK;
936 int end_in_page = pos_in_page + len;
937 loff_t i_size;
938 struct ceph_snap_context *snapc;
939 int r;
940
941retry_locked:
942 /* writepages currently holds page lock, but if we change that later, */
943 wait_on_page_writeback(page);
944
945 /* check snap context */
946 BUG_ON(!ci->i_snap_realm);
947 down_read(&mdsc->snap_rwsem);
948 BUG_ON(!ci->i_snap_realm->cached_context);
949 if (page->private &&
950 (void *)page->private != ci->i_snap_realm->cached_context) {
951 /*
952 * this page is already dirty in another (older) snap
953 * context! is it writeable now?
954 */
955 snapc = get_oldest_context(inode, NULL);
956 up_read(&mdsc->snap_rwsem);
957
958 if (snapc != (void *)page->private) {
959 dout(" page %p snapc %p not current or oldest\n",
960 page, (void *)page->private);
961 /*
962 * queue for writeback, and wait for snapc to
963 * be writeable or written
964 */
965 snapc = ceph_get_snap_context((void *)page->private);
966 unlock_page(page);
967 ceph_queue_writeback(inode);
968 r = wait_event_interruptible(ci->i_cap_wq,
969 context_is_writeable_or_written(inode, snapc));
970 ceph_put_snap_context(snapc);
971 if (r == -ERESTARTSYS)
972 return r;
973 return -EAGAIN;
974 }
975
976 /* yay, writeable, do it now (without dropping page lock) */
977 dout(" page %p snapc %p not current, but oldest\n",
978 page, snapc);
979 if (!clear_page_dirty_for_io(page))
980 goto retry_locked;
981 r = writepage_nounlock(page, NULL);
982 if (r < 0)
983 goto fail_nosnap;
984 goto retry_locked;
985 }
986
987 if (PageUptodate(page)) {
988 dout(" page %p already uptodate\n", page);
989 return 0;
990 }
991
992 /* full page? */
993 if (pos_in_page == 0 && len == PAGE_CACHE_SIZE)
994 return 0;
995
996 /* past end of file? */
997 i_size = inode->i_size; /* caller holds i_mutex */
998
999 if (i_size + len > inode->i_sb->s_maxbytes) {
1000 /* file is too big */
1001 r = -EINVAL;
1002 goto fail;
1003 }
1004
1005 if (page_off >= i_size ||
1006 (pos_in_page == 0 && (pos+len) >= i_size &&
1007 end_in_page - pos_in_page != PAGE_CACHE_SIZE)) {
1008 dout(" zeroing %p 0 - %d and %d - %d\n",
1009 page, pos_in_page, end_in_page, (int)PAGE_CACHE_SIZE);
1010 zero_user_segments(page,
1011 0, pos_in_page,
1012 end_in_page, PAGE_CACHE_SIZE);
1013 return 0;
1014 }
1015
1016 /* we need to read it. */
1017 up_read(&mdsc->snap_rwsem);
1018 r = readpage_nounlock(file, page);
1019 if (r < 0)
1020 goto fail_nosnap;
1021 goto retry_locked;
1022
1023fail:
1024 up_read(&mdsc->snap_rwsem);
1025fail_nosnap:
1026 unlock_page(page);
1027 return r;
1028}
1029
1030/*
1031 * We are only allowed to write into/dirty the page if the page is
1032 * clean, or already dirty within the same snap context.
1033 */
1034static int ceph_write_begin(struct file *file, struct address_space *mapping,
1035 loff_t pos, unsigned len, unsigned flags,
1036 struct page **pagep, void **fsdata)
1037{
1038 struct inode *inode = file->f_dentry->d_inode;
1039 struct page *page;
1040 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
1041 int r;
1042
1043 do {
1044 /* get a page */
1045 page = grab_cache_page_write_begin(mapping, index, 0);
1046 if (!page)
1047 return -ENOMEM;
1048 *pagep = page;
1049
1050 dout("write_begin file %p inode %p page %p %d~%d\n", file,
1051 inode, page, (int)pos, (int)len);
1052
1053 r = ceph_update_writeable_page(file, pos, len, page);
1054 } while (r == -EAGAIN);
1055
1056 return r;
1057}
1058
1059/*
1060 * we don't do anything in here that simple_write_end doesn't do
1061 * except adjust dirty page accounting and drop read lock on
1062 * mdsc->snap_rwsem.
1063 */
1064static int ceph_write_end(struct file *file, struct address_space *mapping,
1065 loff_t pos, unsigned len, unsigned copied,
1066 struct page *page, void *fsdata)
1067{
1068 struct inode *inode = file->f_dentry->d_inode;
1069 struct ceph_client *client = ceph_inode_to_client(inode);
1070 struct ceph_mds_client *mdsc = &client->mdsc;
1071 unsigned from = pos & (PAGE_CACHE_SIZE - 1);
1072 int check_cap = 0;
1073
1074 dout("write_end file %p inode %p page %p %d~%d (%d)\n", file,
1075 inode, page, (int)pos, (int)copied, (int)len);
1076
1077 /* zero the stale part of the page if we did a short copy */
1078 if (copied < len)
1079 zero_user_segment(page, from+copied, len);
1080
1081 /* did file size increase? */
1082 /* (no need for i_size_read(); we caller holds i_mutex */
1083 if (pos+copied > inode->i_size)
1084 check_cap = ceph_inode_set_size(inode, pos+copied);
1085
1086 if (!PageUptodate(page))
1087 SetPageUptodate(page);
1088
1089 set_page_dirty(page);
1090
1091 unlock_page(page);
1092 up_read(&mdsc->snap_rwsem);
1093 page_cache_release(page);
1094
1095 if (check_cap)
1096 ceph_check_caps(ceph_inode(inode), CHECK_CAPS_AUTHONLY, NULL);
1097
1098 return copied;
1099}
1100
1101/*
1102 * we set .direct_IO to indicate direct io is supported, but since we
1103 * intercept O_DIRECT reads and writes early, this function should
1104 * never get called.
1105 */
1106static ssize_t ceph_direct_io(int rw, struct kiocb *iocb,
1107 const struct iovec *iov,
1108 loff_t pos, unsigned long nr_segs)
1109{
1110 WARN_ON(1);
1111 return -EINVAL;
1112}
1113
1114const struct address_space_operations ceph_aops = {
1115 .readpage = ceph_readpage,
1116 .readpages = ceph_readpages,
1117 .writepage = ceph_writepage,
1118 .writepages = ceph_writepages_start,
1119 .write_begin = ceph_write_begin,
1120 .write_end = ceph_write_end,
1121 .set_page_dirty = ceph_set_page_dirty,
1122 .invalidatepage = ceph_invalidatepage,
1123 .releasepage = ceph_releasepage,
1124 .direct_IO = ceph_direct_io,
1125};
1126
1127
1128/*
1129 * vm ops
1130 */
1131
1132/*
1133 * Reuse write_begin here for simplicity.
1134 */
1135static int ceph_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
1136{
1137 struct inode *inode = vma->vm_file->f_dentry->d_inode;
1138 struct page *page = vmf->page;
1139 struct ceph_mds_client *mdsc = &ceph_inode_to_client(inode)->mdsc;
1140 loff_t off = page->index << PAGE_CACHE_SHIFT;
1141 loff_t size, len;
1142 int ret;
1143
1144 size = i_size_read(inode);
1145 if (off + PAGE_CACHE_SIZE <= size)
1146 len = PAGE_CACHE_SIZE;
1147 else
1148 len = size & ~PAGE_CACHE_MASK;
1149
1150 dout("page_mkwrite %p %llu~%llu page %p idx %lu\n", inode,
1151 off, len, page, page->index);
1152
1153 lock_page(page);
1154
1155 ret = VM_FAULT_NOPAGE;
1156 if ((off > size) ||
1157 (page->mapping != inode->i_mapping))
1158 goto out;
1159
1160 ret = ceph_update_writeable_page(vma->vm_file, off, len, page);
1161 if (ret == 0) {
1162 /* success. we'll keep the page locked. */
1163 set_page_dirty(page);
1164 up_read(&mdsc->snap_rwsem);
1165 ret = VM_FAULT_LOCKED;
1166 } else {
1167 if (ret == -ENOMEM)
1168 ret = VM_FAULT_OOM;
1169 else
1170 ret = VM_FAULT_SIGBUS;
1171 }
1172out:
1173 dout("page_mkwrite %p %llu~%llu = %d\n", inode, off, len, ret);
1174 if (ret != VM_FAULT_LOCKED)
1175 unlock_page(page);
1176 return ret;
1177}
1178
1179static struct vm_operations_struct ceph_vmops = {
1180 .fault = filemap_fault,
1181 .page_mkwrite = ceph_page_mkwrite,
1182};
1183
1184int ceph_mmap(struct file *file, struct vm_area_struct *vma)
1185{
1186 struct address_space *mapping = file->f_mapping;
1187
1188 if (!mapping->a_ops->readpage)
1189 return -ENOEXEC;
1190 file_accessed(file);
1191 vma->vm_ops = &ceph_vmops;
1192 vma->vm_flags |= VM_CAN_NONLINEAR;
1193 return 0;
1194}
generated by cgit v1.2.2 (git 2.25.0) at 2025-10-31 14:51:56 -0400