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-rw-r--r--fs/ceph/addr.c1195
1 files changed, 1195 insertions, 0 deletions
diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
new file mode 100644
index 000000000000..aa3cd7cc3e40
--- /dev/null
+++ b/fs/ceph/addr.c
@@ -0,0 +1,1195 @@
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/slab.h>
9#include <linux/pagevec.h>
10#include <linux/task_io_accounting_ops.h>
11
12#include "super.h"
13#include "osd_client.h"
14
15/*
16 * Ceph address space ops.
17 *
18 * There are a few funny things going on here.
19 *
20 * The page->private field is used to reference a struct
21 * ceph_snap_context for _every_ dirty page. This indicates which
22 * snapshot the page was logically dirtied in, and thus which snap
23 * context needs to be associated with the osd write during writeback.
24 *
25 * Similarly, struct ceph_inode_info maintains a set of counters to
26 * count dirty pages on the inode. In the absense of snapshots,
27 * i_wrbuffer_ref == i_wrbuffer_ref_head == the dirty page count.
28 *
29 * When a snapshot is taken (that is, when the client receives
30 * notification that a snapshot was taken), each inode with caps and
31 * with dirty pages (dirty pages implies there is a cap) gets a new
32 * ceph_cap_snap in the i_cap_snaps list (which is sorted in ascending
33 * order, new snaps go to the tail). The i_wrbuffer_ref_head count is
34 * moved to capsnap->dirty. (Unless a sync write is currently in
35 * progress. In that case, the capsnap is said to be "pending", new
36 * writes cannot start, and the capsnap isn't "finalized" until the
37 * write completes (or fails) and a final size/mtime for the inode for
38 * that snap can be settled upon.) i_wrbuffer_ref_head is reset to 0.
39 *
40 * On writeback, we must submit writes to the osd IN SNAP ORDER. So,
41 * we look for the first capsnap in i_cap_snaps and write out pages in
42 * that snap context _only_. Then we move on to the next capsnap,
43 * eventually reaching the "live" or "head" context (i.e., pages that
44 * are not yet snapped) and are writing the most recently dirtied
45 * pages.
46 *
47 * Invalidate and so forth must take care to ensure the dirty page
48 * accounting is preserved.
49 */
50
51#define CONGESTION_ON_THRESH(congestion_kb) (congestion_kb >> (PAGE_SHIFT-10))
52#define CONGESTION_OFF_THRESH(congestion_kb) \
53 (CONGESTION_ON_THRESH(congestion_kb) - \
54 (CONGESTION_ON_THRESH(congestion_kb) >> 2))
55
56
57
58/*
59 * Dirty a page. Optimistically adjust accounting, on the assumption
60 * that we won't race with invalidate. If we do, readjust.
61 */
62static int ceph_set_page_dirty(struct page *page)
63{
64 struct address_space *mapping = page->mapping;
65 struct inode *inode;
66 struct ceph_inode_info *ci;
67 int undo = 0;
68 struct ceph_snap_context *snapc;
69
70 if (unlikely(!mapping))
71 return !TestSetPageDirty(page);
72
73 if (TestSetPageDirty(page)) {
74 dout("%p set_page_dirty %p idx %lu -- already dirty\n",
75 mapping->host, page, page->index);
76 return 0;
77 }
78
79 inode = mapping->host;
80 ci = ceph_inode(inode);
81
82 /*
83 * Note that we're grabbing a snapc ref here without holding
84 * any locks!
85 */
86 snapc = ceph_get_snap_context(ci->i_snap_realm->cached_context);
87
88 /* dirty the head */
89 spin_lock(&inode->i_lock);
90 if (ci->i_wrbuffer_ref_head == 0)
91 ci->i_head_snapc = ceph_get_snap_context(snapc);
92 ++ci->i_wrbuffer_ref_head;
93 if (ci->i_wrbuffer_ref == 0)
94 igrab(inode);
95 ++ci->i_wrbuffer_ref;
96 dout("%p set_page_dirty %p idx %lu head %d/%d -> %d/%d "
97 "snapc %p seq %lld (%d snaps)\n",
98 mapping->host, page, page->index,
99 ci->i_wrbuffer_ref-1, ci->i_wrbuffer_ref_head-1,
100 ci->i_wrbuffer_ref, ci->i_wrbuffer_ref_head,
101 snapc, snapc->seq, snapc->num_snaps);
102 spin_unlock(&inode->i_lock);
103
104 /* now adjust page */
105 spin_lock_irq(&mapping->tree_lock);
106 if (page->mapping) { /* Race with truncate? */
107 WARN_ON_ONCE(!PageUptodate(page));
108
109 if (mapping_cap_account_dirty(mapping)) {
110 __inc_zone_page_state(page, NR_FILE_DIRTY);
111 __inc_bdi_stat(mapping->backing_dev_info,
112 BDI_RECLAIMABLE);
113 task_io_account_write(PAGE_CACHE_SIZE);
114 }
115 radix_tree_tag_set(&mapping->page_tree,
116 page_index(page), PAGECACHE_TAG_DIRTY);
117
118 /*
119 * Reference snap context in page->private. Also set
120 * PagePrivate so that we get invalidatepage callback.
121 */
122 page->private = (unsigned long)snapc;
123 SetPagePrivate(page);
124 } else {
125 dout("ANON set_page_dirty %p (raced truncate?)\n", page);
126 undo = 1;
127 }
128
129 spin_unlock_irq(&mapping->tree_lock);
130
131 if (undo)
132 /* whoops, we failed to dirty the page */
133 ceph_put_wrbuffer_cap_refs(ci, 1, snapc);
134
135 __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
136
137 BUG_ON(!PageDirty(page));
138 return 1;
139}
140
141/*
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
144 * data on the page.
145 */
146static void ceph_invalidatepage(struct page *page, unsigned long offset)
147{
148 struct inode *inode;
149 struct ceph_inode_info *ci;
150 struct ceph_snap_context *snapc = (void *)page->private;
151
152 BUG_ON(!PageLocked(page));
153 BUG_ON(!page->private);
154 BUG_ON(!PagePrivate(page));
155 BUG_ON(!page->mapping);
156
157 inode = page->mapping->host;
158
159 /*
160 * We can get non-dirty pages here due to races between
161 * set_page_dirty and truncate_complete_page; just spit out a
162 * warning, in case we end up with accounting problems later.
163 */
164 if (!PageDirty(page))
165 pr_err("%p invalidatepage %p page not dirty\n", inode, page);
166
167 if (offset == 0)
168 ClearPageChecked(page);
169
170 ci = ceph_inode(inode);
171 if (offset == 0) {
172 dout("%p invalidatepage %p idx %lu full dirty page %lu\n",
173 inode, page, page->index, offset);
174 ceph_put_wrbuffer_cap_refs(ci, 1, snapc);
175 ceph_put_snap_context(snapc);
176 page->private = 0;
177 ClearPagePrivate(page);
178 } else {
179 dout("%p invalidatepage %p idx %lu partial dirty page\n",
180 inode, page, page->index);
181 }
182}
183
184/* just a sanity check */
185static int ceph_releasepage(struct page *page, gfp_t g)
186{
187 struct inode *inode = page->mapping ? page->mapping->host : NULL;
188 dout("%p releasepage %p idx %lu\n", inode, page, page->index);
189 WARN_ON(PageDirty(page));
190 WARN_ON(page->private);
191 WARN_ON(PagePrivate(page));
192 return 0;
193}
194
195/*
196 * read a single page, without unlocking it.
197 */
198static int readpage_nounlock(struct file *filp, struct page *page)
199{
200 struct inode *inode = filp->f_dentry->d_inode;
201 struct ceph_inode_info *ci = ceph_inode(inode);
202 struct ceph_osd_client *osdc = &ceph_inode_to_client(inode)->osdc;
203 int err = 0;
204 u64 len = PAGE_CACHE_SIZE;
205
206 dout("readpage inode %p file %p page %p index %lu\n",
207 inode, filp, page, page->index);
208 err = ceph_osdc_readpages(osdc, ceph_vino(inode), &ci->i_layout,
209 page->index << PAGE_CACHE_SHIFT, &len,
210 ci->i_truncate_seq, ci->i_truncate_size,
211 &page, 1);
212 if (err == -ENOENT)
213 err = 0;
214 if (err < 0) {
215 SetPageError(page);
216 goto out;
217 } else if (err < PAGE_CACHE_SIZE) {
218 /* zero fill remainder of page */
219 zero_user_segment(page, err, PAGE_CACHE_SIZE);
220 }
221 SetPageUptodate(page);
222
223out:
224 return err < 0 ? err : 0;
225}
226
227static int ceph_readpage(struct file *filp, struct page *page)
228{
229 int r = readpage_nounlock(filp, page);
230 unlock_page(page);
231 return r;
232}
233
234/*
235 * Build a vector of contiguous pages from the provided page list.
236 */
237static struct page **page_vector_from_list(struct list_head *page_list,
238 unsigned *nr_pages)
239{
240 struct page **pages;
241 struct page *page;
242 int next_index, contig_pages = 0;
243
244 /* build page vector */
245 pages = kmalloc(sizeof(*pages) * *nr_pages, GFP_NOFS);
246 if (!pages)
247 return ERR_PTR(-ENOMEM);
248
249 BUG_ON(list_empty(page_list));
250 next_index = list_entry(page_list->prev, struct page, lru)->index;
251 list_for_each_entry_reverse(page, page_list, lru) {
252 if (page->index == next_index) {
253 dout("readpages page %d %p\n", contig_pages, page);
254 pages[contig_pages] = page;
255 contig_pages++;
256 next_index++;
257 } else {
258 break;
259 }
260 }
261 *nr_pages = contig_pages;
262 return pages;
263}
264
265/*
266 * Read multiple pages. Leave pages we don't read + unlock in page_list;
267 * the caller (VM) cleans them up.
268 */
269static int ceph_readpages(struct file *file, struct address_space *mapping,
270 struct list_head *page_list, unsigned nr_pages)
271{
272 struct inode *inode = file->f_dentry->d_inode;
273 struct ceph_inode_info *ci = ceph_inode(inode);
274 struct ceph_osd_client *osdc = &ceph_inode_to_client(inode)->osdc;
275 int rc = 0;
276 struct page **pages;
277 struct pagevec pvec;
278 loff_t offset;
279 u64 len;
280
281 dout("readpages %p file %p nr_pages %d\n",
282 inode, file, nr_pages);
283
284 pages = page_vector_from_list(page_list, &nr_pages);
285 if (IS_ERR(pages))
286 return PTR_ERR(pages);
287
288 /* guess read extent */
289 offset = pages[0]->index << PAGE_CACHE_SHIFT;
290 len = nr_pages << PAGE_CACHE_SHIFT;
291 rc = ceph_osdc_readpages(osdc, ceph_vino(inode), &ci->i_layout,
292 offset, &len,
293 ci->i_truncate_seq, ci->i_truncate_size,
294 pages, nr_pages);
295 if (rc == -ENOENT)
296 rc = 0;
297 if (rc < 0)
298 goto out;
299
300 /* set uptodate and add to lru in pagevec-sized chunks */
301 pagevec_init(&pvec, 0);
302 for (; !list_empty(page_list) && len > 0;
303 rc -= PAGE_CACHE_SIZE, len -= PAGE_CACHE_SIZE) {
304 struct page *page =
305 list_entry(page_list->prev, struct page, lru);
306
307 list_del(&page->lru);
308
309 if (rc < (int)PAGE_CACHE_SIZE) {
310 /* zero (remainder of) page */
311 int s = rc < 0 ? 0 : rc;
312 zero_user_segment(page, s, PAGE_CACHE_SIZE);
313 }
314
315 if (add_to_page_cache(page, mapping, page->index, GFP_NOFS)) {
316 page_cache_release(page);
317 dout("readpages %p add_to_page_cache failed %p\n",
318 inode, page);
319 continue;
320 }
321 dout("readpages %p adding %p idx %lu\n", inode, page,
322 page->index);
323 flush_dcache_page(page);
324 SetPageUptodate(page);
325 unlock_page(page);
326 if (pagevec_add(&pvec, page) == 0)
327 pagevec_lru_add_file(&pvec); /* add to lru */
328 }
329 pagevec_lru_add_file(&pvec);
330 rc = 0;
331
332out:
333 kfree(pages);
334 return rc;
335}
336
337/*
338 * Get ref for the oldest snapc for an inode with dirty data... that is, the
339 * only snap context we are allowed to write back.
340 *
341 * Caller holds i_lock.
342 */
343static struct ceph_snap_context *__get_oldest_context(struct inode *inode,
344 u64 *snap_size)
345{
346 struct ceph_inode_info *ci = ceph_inode(inode);
347 struct ceph_snap_context *snapc = NULL;
348 struct ceph_cap_snap *capsnap = NULL;
349
350 list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) {
351 dout(" cap_snap %p snapc %p has %d dirty pages\n", capsnap,
352 capsnap->context, capsnap->dirty_pages);
353 if (capsnap->dirty_pages) {
354 snapc = ceph_get_snap_context(capsnap->context);
355 if (snap_size)
356 *snap_size = capsnap->size;
357 break;
358 }
359 }
360 if (!snapc && ci->i_snap_realm) {
361 snapc = ceph_get_snap_context(ci->i_snap_realm->cached_context);
362 dout(" head snapc %p has %d dirty pages\n",
363 snapc, ci->i_wrbuffer_ref_head);
364 }
365 return snapc;
366}
367
368static struct ceph_snap_context *get_oldest_context(struct inode *inode,
369 u64 *snap_size)
370{
371 struct ceph_snap_context *snapc = NULL;
372
373 spin_lock(&inode->i_lock);
374 snapc = __get_oldest_context(inode, snap_size);
375 spin_unlock(&inode->i_lock);
376 return snapc;
377}
378
379/*
380 * Write a single page, but leave the page locked.
381 *
382 * If we get a write error, set the page error bit, but still adjust the
383 * dirty page accounting (i.e., page is no longer dirty).
384 */
385static int writepage_nounlock(struct page *page, struct writeback_control *wbc)
386{
387 struct inode *inode;
388 struct ceph_inode_info *ci;
389 struct ceph_client *client;
390 struct ceph_osd_client *osdc;
391 loff_t page_off = page->index << PAGE_CACHE_SHIFT;
392 int len = PAGE_CACHE_SIZE;
393 loff_t i_size;
394 int err = 0;
395 struct ceph_snap_context *snapc;
396 u64 snap_size = 0;
397 long writeback_stat;
398
399 dout("writepage %p idx %lu\n", page, page->index);
400
401 if (!page->mapping || !page->mapping->host) {
402 dout("writepage %p - no mapping\n", page);
403 return -EFAULT;
404 }
405 inode = page->mapping->host;
406 ci = ceph_inode(inode);
407 client = ceph_inode_to_client(inode);
408 osdc = &client->osdc;
409
410 /* verify this is a writeable snap context */
411 snapc = (void *)page->private;
412 if (snapc == NULL) {
413 dout("writepage %p page %p not dirty?\n", inode, page);
414 goto out;
415 }
416 if (snapc != get_oldest_context(inode, &snap_size)) {
417 dout("writepage %p page %p snapc %p not writeable - noop\n",
418 inode, page, (void *)page->private);
419 /* we should only noop if called by kswapd */
420 WARN_ON((current->flags & PF_MEMALLOC) == 0);
421 goto out;
422 }
423
424 /* is this a partial page at end of file? */
425 if (snap_size)
426 i_size = snap_size;
427 else
428 i_size = i_size_read(inode);
429 if (i_size < page_off + len)
430 len = i_size - page_off;
431
432 dout("writepage %p page %p index %lu on %llu~%u\n",
433 inode, page, page->index, page_off, len);
434
435 writeback_stat = atomic_long_inc_return(&client->writeback_count);
436 if (writeback_stat >
437 CONGESTION_ON_THRESH(client->mount_args->congestion_kb))
438 set_bdi_congested(&client->backing_dev_info, BLK_RW_ASYNC);
439
440 set_page_writeback(page);
441 err = ceph_osdc_writepages(osdc, ceph_vino(inode),
442 &ci->i_layout, snapc,
443 page_off, len,
444 ci->i_truncate_seq, ci->i_truncate_size,
445 &inode->i_mtime,
446 &page, 1, 0, 0, true);
447 if (err < 0) {
448 dout("writepage setting page/mapping error %d %p\n", err, page);
449 SetPageError(page);
450 mapping_set_error(&inode->i_data, err);
451 if (wbc)
452 wbc->pages_skipped++;
453 } else {
454 dout("writepage cleaned page %p\n", page);
455 err = 0; /* vfs expects us to return 0 */
456 }
457 page->private = 0;
458 ClearPagePrivate(page);
459 end_page_writeback(page);
460 ceph_put_wrbuffer_cap_refs(ci, 1, snapc);
461 ceph_put_snap_context(snapc);
462out:
463 return err;
464}
465
466static int ceph_writepage(struct page *page, struct writeback_control *wbc)
467{
468 int err;
469 struct inode *inode = page->mapping->host;
470 BUG_ON(!inode);
471 igrab(inode);
472 err = writepage_nounlock(page, wbc);
473 unlock_page(page);
474 iput(inode);
475 return err;
476}
477
478
479/*
480 * lame release_pages helper. release_pages() isn't exported to
481 * modules.
482 */
483static void ceph_release_pages(struct page **pages, int num)
484{
485 struct pagevec pvec;
486 int i;
487
488 pagevec_init(&pvec, 0);
489 for (i = 0; i < num; i++) {
490 if (pagevec_add(&pvec, pages[i]) == 0)
491 pagevec_release(&pvec);
492 }
493 pagevec_release(&pvec);
494}
495
496
497/*
498 * async writeback completion handler.
499 *
500 * If we get an error, set the mapping error bit, but not the individual
501 * page error bits.
502 */
503static void writepages_finish(struct ceph_osd_request *req,
504 struct ceph_msg *msg)
505{
506 struct inode *inode = req->r_inode;
507 struct ceph_osd_reply_head *replyhead;
508 struct ceph_osd_op *op;
509 struct ceph_inode_info *ci = ceph_inode(inode);
510 unsigned wrote;
511 struct page *page;
512 int i;
513 struct ceph_snap_context *snapc = req->r_snapc;
514 struct address_space *mapping = inode->i_mapping;
515 struct writeback_control *wbc = req->r_wbc;
516 __s32 rc = -EIO;
517 u64 bytes = 0;
518 struct ceph_client *client = ceph_inode_to_client(inode);
519 long writeback_stat;
520 unsigned issued = __ceph_caps_issued(ci, NULL);
521
522 /* parse reply */
523 replyhead = msg->front.iov_base;
524 WARN_ON(le32_to_cpu(replyhead->num_ops) == 0);
525 op = (void *)(replyhead + 1);
526 rc = le32_to_cpu(replyhead->result);
527 bytes = le64_to_cpu(op->extent.length);
528
529 if (rc >= 0) {
530 /*
531 * Assume we wrote the pages we originally sent. The
532 * osd might reply with fewer pages if our writeback
533 * raced with a truncation and was adjusted at the osd,
534 * so don't believe the reply.
535 */
536 wrote = req->r_num_pages;
537 } else {
538 wrote = 0;
539 mapping_set_error(mapping, rc);
540 }
541 dout("writepages_finish %p rc %d bytes %llu wrote %d (pages)\n",
542 inode, rc, bytes, wrote);
543
544 /* clean all pages */
545 for (i = 0; i < req->r_num_pages; i++) {
546 page = req->r_pages[i];
547 BUG_ON(!page);
548 WARN_ON(!PageUptodate(page));
549
550 writeback_stat =
551 atomic_long_dec_return(&client->writeback_count);
552 if (writeback_stat <
553 CONGESTION_OFF_THRESH(client->mount_args->congestion_kb))
554 clear_bdi_congested(&client->backing_dev_info,
555 BLK_RW_ASYNC);
556
557 if (i >= wrote) {
558 dout("inode %p skipping page %p\n", inode, page);
559 wbc->pages_skipped++;
560 }
561 page->private = 0;
562 ClearPagePrivate(page);
563 ceph_put_snap_context(snapc);
564 dout("unlocking %d %p\n", i, page);
565 end_page_writeback(page);
566
567 /*
568 * We lost the cache cap, need to truncate the page before
569 * it is unlocked, otherwise we'd truncate it later in the
570 * page truncation thread, possibly losing some data that
571 * raced its way in
572 */
573 if ((issued & CEPH_CAP_FILE_CACHE) == 0)
574 generic_error_remove_page(inode->i_mapping, page);
575
576 unlock_page(page);
577 }
578 dout("%p wrote+cleaned %d pages\n", inode, wrote);
579 ceph_put_wrbuffer_cap_refs(ci, req->r_num_pages, snapc);
580
581 ceph_release_pages(req->r_pages, req->r_num_pages);
582 if (req->r_pages_from_pool)
583 mempool_free(req->r_pages,
584 ceph_client(inode->i_sb)->wb_pagevec_pool);
585 else
586 kfree(req->r_pages);
587 ceph_osdc_put_request(req);
588}
589
590/*
591 * allocate a page vec, either directly, or if necessary, via a the
592 * mempool. we avoid the mempool if we can because req->r_num_pages
593 * may be less than the maximum write size.
594 */
595static void alloc_page_vec(struct ceph_client *client,
596 struct ceph_osd_request *req)
597{
598 req->r_pages = kmalloc(sizeof(struct page *) * req->r_num_pages,
599 GFP_NOFS);
600 if (!req->r_pages) {
601 req->r_pages = mempool_alloc(client->wb_pagevec_pool, GFP_NOFS);
602 req->r_pages_from_pool = 1;
603 WARN_ON(!req->r_pages);
604 }
605}
606
607/*
608 * initiate async writeback
609 */
610static int ceph_writepages_start(struct address_space *mapping,
611 struct writeback_control *wbc)
612{
613 struct inode *inode = mapping->host;
614 struct backing_dev_info *bdi = mapping->backing_dev_info;
615 struct ceph_inode_info *ci = ceph_inode(inode);
616 struct ceph_client *client;
617 pgoff_t index, start, end;
618 int range_whole = 0;
619 int should_loop = 1;
620 pgoff_t max_pages = 0, max_pages_ever = 0;
621 struct ceph_snap_context *snapc = NULL, *last_snapc = NULL;
622 struct pagevec pvec;
623 int done = 0;
624 int rc = 0;
625 unsigned wsize = 1 << inode->i_blkbits;
626 struct ceph_osd_request *req = NULL;
627 int do_sync;
628 u64 snap_size = 0;
629
630 /*
631 * Include a 'sync' in the OSD request if this is a data
632 * integrity write (e.g., O_SYNC write or fsync()), or if our
633 * cap is being revoked.
634 */
635 do_sync = wbc->sync_mode == WB_SYNC_ALL;
636 if (ceph_caps_revoking(ci, CEPH_CAP_FILE_BUFFER))
637 do_sync = 1;
638 dout("writepages_start %p dosync=%d (mode=%s)\n",
639 inode, do_sync,
640 wbc->sync_mode == WB_SYNC_NONE ? "NONE" :
641 (wbc->sync_mode == WB_SYNC_ALL ? "ALL" : "HOLD"));
642
643 client = ceph_inode_to_client(inode);
644 if (client->mount_state == CEPH_MOUNT_SHUTDOWN) {
645 pr_warning("writepage_start %p on forced umount\n", inode);
646 return -EIO; /* we're in a forced umount, don't write! */
647 }
648 if (client->mount_args->wsize && client->mount_args->wsize < wsize)
649 wsize = client->mount_args->wsize;
650 if (wsize < PAGE_CACHE_SIZE)
651 wsize = PAGE_CACHE_SIZE;
652 max_pages_ever = wsize >> PAGE_CACHE_SHIFT;
653
654 pagevec_init(&pvec, 0);
655
656 /* ?? */
657 if (wbc->nonblocking && bdi_write_congested(bdi)) {
658 dout(" writepages congested\n");
659 wbc->encountered_congestion = 1;
660 goto out_final;
661 }
662
663 /* where to start/end? */
664 if (wbc->range_cyclic) {
665 start = mapping->writeback_index; /* Start from prev offset */
666 end = -1;
667 dout(" cyclic, start at %lu\n", start);
668 } else {
669 start = wbc->range_start >> PAGE_CACHE_SHIFT;
670 end = wbc->range_end >> PAGE_CACHE_SHIFT;
671 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
672 range_whole = 1;
673 should_loop = 0;
674 dout(" not cyclic, %lu to %lu\n", start, end);
675 }
676 index = start;
677
678retry:
679 /* find oldest snap context with dirty data */
680 ceph_put_snap_context(snapc);
681 snapc = get_oldest_context(inode, &snap_size);
682 if (!snapc) {
683 /* hmm, why does writepages get called when there
684 is no dirty data? */
685 dout(" no snap context with dirty data?\n");
686 goto out;
687 }
688 dout(" oldest snapc is %p seq %lld (%d snaps)\n",
689 snapc, snapc->seq, snapc->num_snaps);
690 if (last_snapc && snapc != last_snapc) {
691 /* if we switched to a newer snapc, restart our scan at the
692 * start of the original file range. */
693 dout(" snapc differs from last pass, restarting at %lu\n",
694 index);
695 index = start;
696 }
697 last_snapc = snapc;
698
699 while (!done && index <= end) {
700 unsigned i;
701 int first;
702 pgoff_t next;
703 int pvec_pages, locked_pages;
704 struct page *page;
705 int want;
706 u64 offset, len;
707 struct ceph_osd_request_head *reqhead;
708 struct ceph_osd_op *op;
709 long writeback_stat;
710
711 next = 0;
712 locked_pages = 0;
713 max_pages = max_pages_ever;
714
715get_more_pages:
716 first = -1;
717 want = min(end - index,
718 min((pgoff_t)PAGEVEC_SIZE,
719 max_pages - (pgoff_t)locked_pages) - 1)
720 + 1;
721 pvec_pages = pagevec_lookup_tag(&pvec, mapping, &index,
722 PAGECACHE_TAG_DIRTY,
723 want);
724 dout("pagevec_lookup_tag got %d\n", pvec_pages);
725 if (!pvec_pages && !locked_pages)
726 break;
727 for (i = 0; i < pvec_pages && locked_pages < max_pages; i++) {
728 page = pvec.pages[i];
729 dout("? %p idx %lu\n", page, page->index);
730 if (locked_pages == 0)
731 lock_page(page); /* first page */
732 else if (!trylock_page(page))
733 break;
734
735 /* only dirty pages, or our accounting breaks */
736 if (unlikely(!PageDirty(page)) ||
737 unlikely(page->mapping != mapping)) {
738 dout("!dirty or !mapping %p\n", page);
739 unlock_page(page);
740 break;
741 }
742 if (!wbc->range_cyclic && page->index > end) {
743 dout("end of range %p\n", page);
744 done = 1;
745 unlock_page(page);
746 break;
747 }
748 if (next && (page->index != next)) {
749 dout("not consecutive %p\n", page);
750 unlock_page(page);
751 break;
752 }
753 if (wbc->sync_mode != WB_SYNC_NONE) {
754 dout("waiting on writeback %p\n", page);
755 wait_on_page_writeback(page);
756 }
757 if ((snap_size && page_offset(page) > snap_size) ||
758 (!snap_size &&
759 page_offset(page) > i_size_read(inode))) {
760 dout("%p page eof %llu\n", page, snap_size ?
761 snap_size : i_size_read(inode));
762 done = 1;
763 unlock_page(page);
764 break;
765 }
766 if (PageWriteback(page)) {
767 dout("%p under writeback\n", page);
768 unlock_page(page);
769 break;
770 }
771
772 /* only if matching snap context */
773 if (snapc != (void *)page->private) {
774 dout("page snapc %p != oldest %p\n",
775 (void *)page->private, snapc);
776 unlock_page(page);
777 if (!locked_pages)
778 continue; /* keep looking for snap */
779 break;
780 }
781
782 if (!clear_page_dirty_for_io(page)) {
783 dout("%p !clear_page_dirty_for_io\n", page);
784 unlock_page(page);
785 break;
786 }
787
788 /* ok */
789 if (locked_pages == 0) {
790 /* prepare async write request */
791 offset = page->index << PAGE_CACHE_SHIFT;
792 len = wsize;
793 req = ceph_osdc_new_request(&client->osdc,
794 &ci->i_layout,
795 ceph_vino(inode),
796 offset, &len,
797 CEPH_OSD_OP_WRITE,
798 CEPH_OSD_FLAG_WRITE |
799 CEPH_OSD_FLAG_ONDISK,
800 snapc, do_sync,
801 ci->i_truncate_seq,
802 ci->i_truncate_size,
803 &inode->i_mtime, true, 1);
804 max_pages = req->r_num_pages;
805
806 alloc_page_vec(client, req);
807 req->r_callback = writepages_finish;
808 req->r_inode = inode;
809 req->r_wbc = wbc;
810 }
811
812 /* note position of first page in pvec */
813 if (first < 0)
814 first = i;
815 dout("%p will write page %p idx %lu\n",
816 inode, page, page->index);
817
818 writeback_stat = atomic_long_inc_return(&client->writeback_count);
819 if (writeback_stat > CONGESTION_ON_THRESH(client->mount_args->congestion_kb)) {
820 set_bdi_congested(&client->backing_dev_info, BLK_RW_ASYNC);
821 }
822
823 set_page_writeback(page);
824 req->r_pages[locked_pages] = page;
825 locked_pages++;
826 next = page->index + 1;
827 }
828
829 /* did we get anything? */
830 if (!locked_pages)
831 goto release_pvec_pages;
832 if (i) {
833 int j;
834 BUG_ON(!locked_pages || first < 0);
835
836 if (pvec_pages && i == pvec_pages &&
837 locked_pages < max_pages) {
838 dout("reached end pvec, trying for more\n");
839 pagevec_reinit(&pvec);
840 goto get_more_pages;
841 }
842
843 /* shift unused pages over in the pvec... we
844 * will need to release them below. */
845 for (j = i; j < pvec_pages; j++) {
846 dout(" pvec leftover page %p\n",
847 pvec.pages[j]);
848 pvec.pages[j-i+first] = pvec.pages[j];
849 }
850 pvec.nr -= i-first;
851 }
852
853 /* submit the write */
854 offset = req->r_pages[0]->index << PAGE_CACHE_SHIFT;
855 len = min((snap_size ? snap_size : i_size_read(inode)) - offset,
856 (u64)locked_pages << PAGE_CACHE_SHIFT);
857 dout("writepages got %d pages at %llu~%llu\n",
858 locked_pages, offset, len);
859
860 /* revise final length, page count */
861 req->r_num_pages = locked_pages;
862 reqhead = req->r_request->front.iov_base;
863 op = (void *)(reqhead + 1);
864 op->extent.length = cpu_to_le64(len);
865 op->payload_len = cpu_to_le32(len);
866 req->r_request->hdr.data_len = cpu_to_le32(len);
867
868 ceph_osdc_start_request(&client->osdc, req, true);
869 req = NULL;
870
871 /* continue? */
872 index = next;
873 wbc->nr_to_write -= locked_pages;
874 if (wbc->nr_to_write <= 0)
875 done = 1;
876
877release_pvec_pages:
878 dout("pagevec_release on %d pages (%p)\n", (int)pvec.nr,
879 pvec.nr ? pvec.pages[0] : NULL);
880 pagevec_release(&pvec);
881
882 if (locked_pages && !done)
883 goto retry;
884 }
885
886 if (should_loop && !done) {
887 /* more to do; loop back to beginning of file */
888 dout("writepages looping back to beginning of file\n");
889 should_loop = 0;
890 index = 0;
891 goto retry;
892 }
893
894 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
895 mapping->writeback_index = index;
896
897out:
898 if (req)
899 ceph_osdc_put_request(req);
900 if (rc > 0)
901 rc = 0; /* vfs expects us to return 0 */
902 ceph_put_snap_context(snapc);
903 dout("writepages done, rc = %d\n", rc);
904out_final:
905 return rc;
906}
907
908
909
910/*
911 * See if a given @snapc is either writeable, or already written.
912 */
913static int context_is_writeable_or_written(struct inode *inode,
914 struct ceph_snap_context *snapc)
915{
916 struct ceph_snap_context *oldest = get_oldest_context(inode, NULL);
917 return !oldest || snapc->seq <= oldest->seq;
918}
919
920/*
921 * We are only allowed to write into/dirty the page if the page is
922 * clean, or already dirty within the same snap context.
923 *
924 * called with page locked.
925 * return success with page locked,
926 * or any failure (incl -EAGAIN) with page unlocked.
927 */
928static int ceph_update_writeable_page(struct file *file,
929 loff_t pos, unsigned len,
930 struct page *page)
931{
932 struct inode *inode = file->f_dentry->d_inode;
933 struct ceph_inode_info *ci = ceph_inode(inode);
934 struct ceph_mds_client *mdsc = &ceph_inode_to_client(inode)->mdsc;
935 loff_t page_off = pos & PAGE_CACHE_MASK;
936 int pos_in_page = pos & ~PAGE_CACHE_MASK;
937 int end_in_page = pos_in_page + len;
938 loff_t i_size;
939 struct ceph_snap_context *snapc;
940 int r;
941
942retry_locked:
943 /* writepages currently holds page lock, but if we change that later, */
944 wait_on_page_writeback(page);
945
946 /* check snap context */
947 BUG_ON(!ci->i_snap_realm);
948 down_read(&mdsc->snap_rwsem);
949 BUG_ON(!ci->i_snap_realm->cached_context);
950 if (page->private &&
951 (void *)page->private != ci->i_snap_realm->cached_context) {
952 /*
953 * this page is already dirty in another (older) snap
954 * context! is it writeable now?
955 */
956 snapc = get_oldest_context(inode, NULL);
957 up_read(&mdsc->snap_rwsem);
958
959 if (snapc != (void *)page->private) {
960 dout(" page %p snapc %p not current or oldest\n",
961 page, (void *)page->private);
962 /*
963 * queue for writeback, and wait for snapc to
964 * be writeable or written
965 */
966 snapc = ceph_get_snap_context((void *)page->private);
967 unlock_page(page);
968 ceph_queue_writeback(inode);
969 r = wait_event_interruptible(ci->i_cap_wq,
970 context_is_writeable_or_written(inode, snapc));
971 ceph_put_snap_context(snapc);
972 if (r == -ERESTARTSYS)
973 return r;
974 return -EAGAIN;
975 }
976
977 /* yay, writeable, do it now (without dropping page lock) */
978 dout(" page %p snapc %p not current, but oldest\n",
979 page, snapc);
980 if (!clear_page_dirty_for_io(page))
981 goto retry_locked;
982 r = writepage_nounlock(page, NULL);
983 if (r < 0)
984 goto fail_nosnap;
985 goto retry_locked;
986 }
987
988 if (PageUptodate(page)) {
989 dout(" page %p already uptodate\n", page);
990 return 0;
991 }
992
993 /* full page? */
994 if (pos_in_page == 0 && len == PAGE_CACHE_SIZE)
995 return 0;
996
997 /* past end of file? */
998 i_size = inode->i_size; /* caller holds i_mutex */
999
1000 if (i_size + len > inode->i_sb->s_maxbytes) {
1001 /* file is too big */
1002 r = -EINVAL;
1003 goto fail;
1004 }
1005
1006 if (page_off >= i_size ||
1007 (pos_in_page == 0 && (pos+len) >= i_size &&
1008 end_in_page - pos_in_page != PAGE_CACHE_SIZE)) {
1009 dout(" zeroing %p 0 - %d and %d - %d\n",
1010 page, pos_in_page, end_in_page, (int)PAGE_CACHE_SIZE);
1011 zero_user_segments(page,
1012 0, pos_in_page,
1013 end_in_page, PAGE_CACHE_SIZE);
1014 return 0;
1015 }
1016
1017 /* we need to read it. */
1018 up_read(&mdsc->snap_rwsem);
1019 r = readpage_nounlock(file, page);
1020 if (r < 0)
1021 goto fail_nosnap;
1022 goto retry_locked;
1023
1024fail:
1025 up_read(&mdsc->snap_rwsem);
1026fail_nosnap:
1027 unlock_page(page);
1028 return r;
1029}
1030
1031/*
1032 * We are only allowed to write into/dirty the page if the page is
1033 * clean, or already dirty within the same snap context.
1034 */
1035static int ceph_write_begin(struct file *file, struct address_space *mapping,
1036 loff_t pos, unsigned len, unsigned flags,
1037 struct page **pagep, void **fsdata)
1038{
1039 struct inode *inode = file->f_dentry->d_inode;
1040 struct page *page;
1041 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
1042 int r;
1043
1044 do {
1045 /* get a page */
1046 page = grab_cache_page_write_begin(mapping, index, 0);
1047 if (!page)
1048 return -ENOMEM;
1049 *pagep = page;
1050
1051 dout("write_begin file %p inode %p page %p %d~%d\n", file,
1052 inode, page, (int)pos, (int)len);
1053
1054 r = ceph_update_writeable_page(file, pos, len, page);
1055 } while (r == -EAGAIN);
1056
1057 return r;
1058}
1059
1060/*
1061 * we don't do anything in here that simple_write_end doesn't do
1062 * except adjust dirty page accounting and drop read lock on
1063 * mdsc->snap_rwsem.
1064 */
1065static int ceph_write_end(struct file *file, struct address_space *mapping,
1066 loff_t pos, unsigned len, unsigned copied,
1067 struct page *page, void *fsdata)
1068{
1069 struct inode *inode = file->f_dentry->d_inode;
1070 struct ceph_client *client = ceph_inode_to_client(inode);
1071 struct ceph_mds_client *mdsc = &client->mdsc;
1072 unsigned from = pos & (PAGE_CACHE_SIZE - 1);
1073 int check_cap = 0;
1074
1075 dout("write_end file %p inode %p page %p %d~%d (%d)\n", file,
1076 inode, page, (int)pos, (int)copied, (int)len);
1077
1078 /* zero the stale part of the page if we did a short copy */
1079 if (copied < len)
1080 zero_user_segment(page, from+copied, len);
1081
1082 /* did file size increase? */
1083 /* (no need for i_size_read(); we caller holds i_mutex */
1084 if (pos+copied > inode->i_size)
1085 check_cap = ceph_inode_set_size(inode, pos+copied);
1086
1087 if (!PageUptodate(page))
1088 SetPageUptodate(page);
1089
1090 set_page_dirty(page);
1091
1092 unlock_page(page);
1093 up_read(&mdsc->snap_rwsem);
1094 page_cache_release(page);
1095
1096 if (check_cap)
1097 ceph_check_caps(ceph_inode(inode), CHECK_CAPS_AUTHONLY, NULL);
1098
1099 return copied;
1100}
1101
1102/*
1103 * we set .direct_IO to indicate direct io is supported, but since we
1104 * intercept O_DIRECT reads and writes early, this function should
1105 * never get called.
1106 */
1107static ssize_t ceph_direct_io(int rw, struct kiocb *iocb,
1108 const struct iovec *iov,
1109 loff_t pos, unsigned long nr_segs)
1110{
1111 WARN_ON(1);
1112 return -EINVAL;
1113}
1114
1115const struct address_space_operations ceph_aops = {
1116 .readpage = ceph_readpage,
1117 .readpages = ceph_readpages,
1118 .writepage = ceph_writepage,
1119 .writepages = ceph_writepages_start,
1120 .write_begin = ceph_write_begin,
1121 .write_end = ceph_write_end,
1122 .set_page_dirty = ceph_set_page_dirty,
1123 .invalidatepage = ceph_invalidatepage,
1124 .releasepage = ceph_releasepage,
1125 .direct_IO = ceph_direct_io,
1126};
1127
1128
1129/*
1130 * vm ops
1131 */
1132
1133/*
1134 * Reuse write_begin here for simplicity.
1135 */
1136static int ceph_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
1137{
1138 struct inode *inode = vma->vm_file->f_dentry->d_inode;
1139 struct page *page = vmf->page;
1140 struct ceph_mds_client *mdsc = &ceph_inode_to_client(inode)->mdsc;
1141 loff_t off = page->index << PAGE_CACHE_SHIFT;
1142 loff_t size, len;
1143 int ret;
1144
1145 size = i_size_read(inode);
1146 if (off + PAGE_CACHE_SIZE <= size)
1147 len = PAGE_CACHE_SIZE;
1148 else
1149 len = size & ~PAGE_CACHE_MASK;
1150
1151 dout("page_mkwrite %p %llu~%llu page %p idx %lu\n", inode,
1152 off, len, page, page->index);
1153
1154 lock_page(page);
1155
1156 ret = VM_FAULT_NOPAGE;
1157 if ((off > size) ||
1158 (page->mapping != inode->i_mapping))
1159 goto out;
1160
1161 ret = ceph_update_writeable_page(vma->vm_file, off, len, page);
1162 if (ret == 0) {
1163 /* success. we'll keep the page locked. */
1164 set_page_dirty(page);
1165 up_read(&mdsc->snap_rwsem);
1166 ret = VM_FAULT_LOCKED;
1167 } else {
1168 if (ret == -ENOMEM)
1169 ret = VM_FAULT_OOM;
1170 else
1171 ret = VM_FAULT_SIGBUS;
1172 }
1173out:
1174 dout("page_mkwrite %p %llu~%llu = %d\n", inode, off, len, ret);
1175 if (ret != VM_FAULT_LOCKED)
1176 unlock_page(page);
1177 return ret;
1178}
1179
1180static struct vm_operations_struct ceph_vmops = {
1181 .fault = filemap_fault,
1182 .page_mkwrite = ceph_page_mkwrite,
1183};
1184
1185int ceph_mmap(struct file *file, struct vm_area_struct *vma)
1186{
1187 struct address_space *mapping = file->f_mapping;
1188
1189 if (!mapping->a_ops->readpage)
1190 return -ENOEXEC;
1191 file_accessed(file);
1192 vma->vm_ops = &ceph_vmops;
1193 vma->vm_flags |= VM_CAN_NONLINEAR;
1194 return 0;
1195}
generated by cgit v1.2.2 (git 2.25.0) at 2025-10-31 21:19:38 -0400