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1// SPDX-License-Identifier: GPL-2.0
2#include <linux/ceph/ceph_debug.h>
3
4#include <linux/backing-dev.h>
5#include <linux/fs.h>
6#include <linux/mm.h>
7#include <linux/pagemap.h>
8#include <linux/writeback.h> /* generic_writepages */
9#include <linux/slab.h>
10#include <linux/pagevec.h>
11#include <linux/task_io_accounting_ops.h>
12#include <linux/signal.h>
13#include <linux/iversion.h>
14#include <linux/ktime.h>
15
16#include "super.h"
17#include "mds_client.h"
18#include "cache.h"
19#include "metric.h"
20#include <linux/ceph/osd_client.h>
21#include <linux/ceph/striper.h>
22
23/*
24 * Ceph address space ops.
25 *
26 * There are a few funny things going on here.
27 *
28 * The page->private field is used to reference a struct
29 * ceph_snap_context for _every_ dirty page. This indicates which
30 * snapshot the page was logically dirtied in, and thus which snap
31 * context needs to be associated with the osd write during writeback.
32 *
33 * Similarly, struct ceph_inode_info maintains a set of counters to
34 * count dirty pages on the inode. In the absence of snapshots,
35 * i_wrbuffer_ref == i_wrbuffer_ref_head == the dirty page count.
36 *
37 * When a snapshot is taken (that is, when the client receives
38 * notification that a snapshot was taken), each inode with caps and
39 * with dirty pages (dirty pages implies there is a cap) gets a new
40 * ceph_cap_snap in the i_cap_snaps list (which is sorted in ascending
41 * order, new snaps go to the tail). The i_wrbuffer_ref_head count is
42 * moved to capsnap->dirty. (Unless a sync write is currently in
43 * progress. In that case, the capsnap is said to be "pending", new
44 * writes cannot start, and the capsnap isn't "finalized" until the
45 * write completes (or fails) and a final size/mtime for the inode for
46 * that snap can be settled upon.) i_wrbuffer_ref_head is reset to 0.
47 *
48 * On writeback, we must submit writes to the osd IN SNAP ORDER. So,
49 * we look for the first capsnap in i_cap_snaps and write out pages in
50 * that snap context _only_. Then we move on to the next capsnap,
51 * eventually reaching the "live" or "head" context (i.e., pages that
52 * are not yet snapped) and are writing the most recently dirtied
53 * pages.
54 *
55 * Invalidate and so forth must take care to ensure the dirty page
56 * accounting is preserved.
57 */
58
59#define CONGESTION_ON_THRESH(congestion_kb) (congestion_kb >> (PAGE_SHIFT-10))
60#define CONGESTION_OFF_THRESH(congestion_kb) \
61 (CONGESTION_ON_THRESH(congestion_kb) - \
62 (CONGESTION_ON_THRESH(congestion_kb) >> 2))
63
64static inline struct ceph_snap_context *page_snap_context(struct page *page)
65{
66 if (PagePrivate(page))
67 return (void *)page->private;
68 return NULL;
69}
70
71/*
72 * Dirty a page. Optimistically adjust accounting, on the assumption
73 * that we won't race with invalidate. If we do, readjust.
74 */
75static int ceph_set_page_dirty(struct page *page)
76{
77 struct address_space *mapping = page->mapping;
78 struct inode *inode;
79 struct ceph_inode_info *ci;
80 struct ceph_snap_context *snapc;
81 int ret;
82
83 if (unlikely(!mapping))
84 return !TestSetPageDirty(page);
85
86 if (PageDirty(page)) {
87 dout("%p set_page_dirty %p idx %lu -- already dirty\n",
88 mapping->host, page, page->index);
89 BUG_ON(!PagePrivate(page));
90 return 0;
91 }
92
93 inode = mapping->host;
94 ci = ceph_inode(inode);
95
96 /* dirty the head */
97 spin_lock(&ci->i_ceph_lock);
98 BUG_ON(ci->i_wr_ref == 0); // caller should hold Fw reference
99 if (__ceph_have_pending_cap_snap(ci)) {
100 struct ceph_cap_snap *capsnap =
101 list_last_entry(&ci->i_cap_snaps,
102 struct ceph_cap_snap,
103 ci_item);
104 snapc = ceph_get_snap_context(capsnap->context);
105 capsnap->dirty_pages++;
106 } else {
107 BUG_ON(!ci->i_head_snapc);
108 snapc = ceph_get_snap_context(ci->i_head_snapc);
109 ++ci->i_wrbuffer_ref_head;
110 }
111 if (ci->i_wrbuffer_ref == 0)
112 ihold(inode);
113 ++ci->i_wrbuffer_ref;
114 dout("%p set_page_dirty %p idx %lu head %d/%d -> %d/%d "
115 "snapc %p seq %lld (%d snaps)\n",
116 mapping->host, page, page->index,
117 ci->i_wrbuffer_ref-1, ci->i_wrbuffer_ref_head-1,
118 ci->i_wrbuffer_ref, ci->i_wrbuffer_ref_head,
119 snapc, snapc->seq, snapc->num_snaps);
120 spin_unlock(&ci->i_ceph_lock);
121
122 /*
123 * Reference snap context in page->private. Also set
124 * PagePrivate so that we get invalidatepage callback.
125 */
126 BUG_ON(PagePrivate(page));
127 page->private = (unsigned long)snapc;
128 SetPagePrivate(page);
129
130 ret = __set_page_dirty_nobuffers(page);
131 WARN_ON(!PageLocked(page));
132 WARN_ON(!page->mapping);
133
134 return ret;
135}
136
137/*
138 * If we are truncating the full page (i.e. offset == 0), adjust the
139 * dirty page counters appropriately. Only called if there is private
140 * data on the page.
141 */
142static void ceph_invalidatepage(struct page *page, unsigned int offset,
143 unsigned int length)
144{
145 struct inode *inode;
146 struct ceph_inode_info *ci;
147 struct ceph_snap_context *snapc = page_snap_context(page);
148
149 inode = page->mapping->host;
150 ci = ceph_inode(inode);
151
152 if (offset != 0 || length != PAGE_SIZE) {
153 dout("%p invalidatepage %p idx %lu partial dirty page %u~%u\n",
154 inode, page, page->index, offset, length);
155 return;
156 }
157
158 ceph_invalidate_fscache_page(inode, page);
159
160 WARN_ON(!PageLocked(page));
161 if (!PagePrivate(page))
162 return;
163
164 dout("%p invalidatepage %p idx %lu full dirty page\n",
165 inode, page, page->index);
166
167 ceph_put_wrbuffer_cap_refs(ci, 1, snapc);
168 ceph_put_snap_context(snapc);
169 page->private = 0;
170 ClearPagePrivate(page);
171}
172
173static int ceph_releasepage(struct page *page, gfp_t g)
174{
175 dout("%p releasepage %p idx %lu (%sdirty)\n", page->mapping->host,
176 page, page->index, PageDirty(page) ? "" : "not ");
177
178 /* Can we release the page from the cache? */
179 if (!ceph_release_fscache_page(page, g))
180 return 0;
181
182 return !PagePrivate(page);
183}
184
185/*
186 * Read some contiguous pages. If we cross a stripe boundary, shorten
187 * *plen. Return number of bytes read, or error.
188 */
189static int ceph_sync_readpages(struct ceph_fs_client *fsc,
190 struct ceph_vino vino,
191 struct ceph_file_layout *layout,
192 u64 off, u64 *plen,
193 u32 truncate_seq, u64 truncate_size,
194 struct page **pages, int num_pages,
195 int page_align)
196{
197 struct ceph_osd_client *osdc = &fsc->client->osdc;
198 struct ceph_osd_request *req;
199 int rc = 0;
200
201 dout("readpages on ino %llx.%llx on %llu~%llu\n", vino.ino,
202 vino.snap, off, *plen);
203 req = ceph_osdc_new_request(osdc, layout, vino, off, plen, 0, 1,
204 CEPH_OSD_OP_READ, CEPH_OSD_FLAG_READ,
205 NULL, truncate_seq, truncate_size,
206 false);
207 if (IS_ERR(req))
208 return PTR_ERR(req);
209
210 /* it may be a short read due to an object boundary */
211 osd_req_op_extent_osd_data_pages(req, 0,
212 pages, *plen, page_align, false, false);
213
214 dout("readpages final extent is %llu~%llu (%llu bytes align %d)\n",
215 off, *plen, *plen, page_align);
216
217 rc = ceph_osdc_start_request(osdc, req, false);
218 if (!rc)
219 rc = ceph_osdc_wait_request(osdc, req);
220
221 ceph_update_read_latency(&fsc->mdsc->metric, req->r_start_latency,
222 req->r_end_latency, rc);
223
224 ceph_osdc_put_request(req);
225 dout("readpages result %d\n", rc);
226 return rc;
227}
228
229/*
230 * read a single page, without unlocking it.
231 */
232static int ceph_do_readpage(struct file *filp, struct page *page)
233{
234 struct inode *inode = file_inode(filp);
235 struct ceph_inode_info *ci = ceph_inode(inode);
236 struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
237 int err = 0;
238 u64 off = page_offset(page);
239 u64 len = PAGE_SIZE;
240
241 if (off >= i_size_read(inode)) {
242 zero_user_segment(page, 0, PAGE_SIZE);
243 SetPageUptodate(page);
244 return 0;
245 }
246
247 if (ci->i_inline_version != CEPH_INLINE_NONE) {
248 /*
249 * Uptodate inline data should have been added
250 * into page cache while getting Fcr caps.
251 */
252 if (off == 0)
253 return -EINVAL;
254 zero_user_segment(page, 0, PAGE_SIZE);
255 SetPageUptodate(page);
256 return 0;
257 }
258
259 err = ceph_readpage_from_fscache(inode, page);
260 if (err == 0)
261 return -EINPROGRESS;
262
263 dout("readpage inode %p file %p page %p index %lu\n",
264 inode, filp, page, page->index);
265 err = ceph_sync_readpages(fsc, ceph_vino(inode),
266 &ci->i_layout, off, &len,
267 ci->i_truncate_seq, ci->i_truncate_size,
268 &page, 1, 0);
269 if (err == -ENOENT)
270 err = 0;
271 if (err < 0) {
272 SetPageError(page);
273 ceph_fscache_readpage_cancel(inode, page);
274 if (err == -EBLACKLISTED)
275 fsc->blacklisted = true;
276 goto out;
277 }
278 if (err < PAGE_SIZE)
279 /* zero fill remainder of page */
280 zero_user_segment(page, err, PAGE_SIZE);
281 else
282 flush_dcache_page(page);
283
284 SetPageUptodate(page);
285 ceph_readpage_to_fscache(inode, page);
286
287out:
288 return err < 0 ? err : 0;
289}
290
291static int ceph_readpage(struct file *filp, struct page *page)
292{
293 int r = ceph_do_readpage(filp, page);
294 if (r != -EINPROGRESS)
295 unlock_page(page);
296 else
297 r = 0;
298 return r;
299}
300
301/*
302 * Finish an async read(ahead) op.
303 */
304static void finish_read(struct ceph_osd_request *req)
305{
306 struct inode *inode = req->r_inode;
307 struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
308 struct ceph_osd_data *osd_data;
309 int rc = req->r_result <= 0 ? req->r_result : 0;
310 int bytes = req->r_result >= 0 ? req->r_result : 0;
311 int num_pages;
312 int i;
313
314 dout("finish_read %p req %p rc %d bytes %d\n", inode, req, rc, bytes);
315 if (rc == -EBLACKLISTED)
316 ceph_inode_to_client(inode)->blacklisted = true;
317
318 /* unlock all pages, zeroing any data we didn't read */
319 osd_data = osd_req_op_extent_osd_data(req, 0);
320 BUG_ON(osd_data->type != CEPH_OSD_DATA_TYPE_PAGES);
321 num_pages = calc_pages_for((u64)osd_data->alignment,
322 (u64)osd_data->length);
323 for (i = 0; i < num_pages; i++) {
324 struct page *page = osd_data->pages[i];
325
326 if (rc < 0 && rc != -ENOENT) {
327 ceph_fscache_readpage_cancel(inode, page);
328 goto unlock;
329 }
330 if (bytes < (int)PAGE_SIZE) {
331 /* zero (remainder of) page */
332 int s = bytes < 0 ? 0 : bytes;
333 zero_user_segment(page, s, PAGE_SIZE);
334 }
335 dout("finish_read %p uptodate %p idx %lu\n", inode, page,
336 page->index);
337 flush_dcache_page(page);
338 SetPageUptodate(page);
339 ceph_readpage_to_fscache(inode, page);
340unlock:
341 unlock_page(page);
342 put_page(page);
343 bytes -= PAGE_SIZE;
344 }
345
346 ceph_update_read_latency(&fsc->mdsc->metric, req->r_start_latency,
347 req->r_end_latency, rc);
348
349 kfree(osd_data->pages);
350}
351
352/*
353 * start an async read(ahead) operation. return nr_pages we submitted
354 * a read for on success, or negative error code.
355 */
356static int start_read(struct inode *inode, struct ceph_rw_context *rw_ctx,
357 struct list_head *page_list, int max)
358{
359 struct ceph_osd_client *osdc =
360 &ceph_inode_to_client(inode)->client->osdc;
361 struct ceph_inode_info *ci = ceph_inode(inode);
362 struct page *page = lru_to_page(page_list);
363 struct ceph_vino vino;
364 struct ceph_osd_request *req;
365 u64 off;
366 u64 len;
367 int i;
368 struct page **pages;
369 pgoff_t next_index;
370 int nr_pages = 0;
371 int got = 0;
372 int ret = 0;
373
374 if (!rw_ctx) {
375 /* caller of readpages does not hold buffer and read caps
376 * (fadvise, madvise and readahead cases) */
377 int want = CEPH_CAP_FILE_CACHE;
378 ret = ceph_try_get_caps(inode, CEPH_CAP_FILE_RD, want,
379 true, &got);
380 if (ret < 0) {
381 dout("start_read %p, error getting cap\n", inode);
382 } else if (!(got & want)) {
383 dout("start_read %p, no cache cap\n", inode);
384 ret = 0;
385 }
386 if (ret <= 0) {
387 if (got)
388 ceph_put_cap_refs(ci, got);
389 while (!list_empty(page_list)) {
390 page = lru_to_page(page_list);
391 list_del(&page->lru);
392 put_page(page);
393 }
394 return ret;
395 }
396 }
397
398 off = (u64) page_offset(page);
399
400 /* count pages */
401 next_index = page->index;
402 list_for_each_entry_reverse(page, page_list, lru) {
403 if (page->index != next_index)
404 break;
405 nr_pages++;
406 next_index++;
407 if (max && nr_pages == max)
408 break;
409 }
410 len = nr_pages << PAGE_SHIFT;
411 dout("start_read %p nr_pages %d is %lld~%lld\n", inode, nr_pages,
412 off, len);
413 vino = ceph_vino(inode);
414 req = ceph_osdc_new_request(osdc, &ci->i_layout, vino, off, &len,
415 0, 1, CEPH_OSD_OP_READ,
416 CEPH_OSD_FLAG_READ, NULL,
417 ci->i_truncate_seq, ci->i_truncate_size,
418 false);
419 if (IS_ERR(req)) {
420 ret = PTR_ERR(req);
421 goto out;
422 }
423
424 /* build page vector */
425 nr_pages = calc_pages_for(0, len);
426 pages = kmalloc_array(nr_pages, sizeof(*pages), GFP_KERNEL);
427 if (!pages) {
428 ret = -ENOMEM;
429 goto out_put;
430 }
431 for (i = 0; i < nr_pages; ++i) {
432 page = list_entry(page_list->prev, struct page, lru);
433 BUG_ON(PageLocked(page));
434 list_del(&page->lru);
435
436 dout("start_read %p adding %p idx %lu\n", inode, page,
437 page->index);
438 if (add_to_page_cache_lru(page, &inode->i_data, page->index,
439 GFP_KERNEL)) {
440 ceph_fscache_uncache_page(inode, page);
441 put_page(page);
442 dout("start_read %p add_to_page_cache failed %p\n",
443 inode, page);
444 nr_pages = i;
445 if (nr_pages > 0) {
446 len = nr_pages << PAGE_SHIFT;
447 osd_req_op_extent_update(req, 0, len);
448 break;
449 }
450 goto out_pages;
451 }
452 pages[i] = page;
453 }
454 osd_req_op_extent_osd_data_pages(req, 0, pages, len, 0, false, false);
455 req->r_callback = finish_read;
456 req->r_inode = inode;
457
458 dout("start_read %p starting %p %lld~%lld\n", inode, req, off, len);
459 ret = ceph_osdc_start_request(osdc, req, false);
460 if (ret < 0)
461 goto out_pages;
462 ceph_osdc_put_request(req);
463
464 /* After adding locked pages to page cache, the inode holds cache cap.
465 * So we can drop our cap refs. */
466 if (got)
467 ceph_put_cap_refs(ci, got);
468
469 return nr_pages;
470
471out_pages:
472 for (i = 0; i < nr_pages; ++i) {
473 ceph_fscache_readpage_cancel(inode, pages[i]);
474 unlock_page(pages[i]);
475 }
476 ceph_put_page_vector(pages, nr_pages, false);
477out_put:
478 ceph_osdc_put_request(req);
479out:
480 if (got)
481 ceph_put_cap_refs(ci, got);
482 return ret;
483}
484
485
486/*
487 * Read multiple pages. Leave pages we don't read + unlock in page_list;
488 * the caller (VM) cleans them up.
489 */
490static int ceph_readpages(struct file *file, struct address_space *mapping,
491 struct list_head *page_list, unsigned nr_pages)
492{
493 struct inode *inode = file_inode(file);
494 struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
495 struct ceph_file_info *fi = file->private_data;
496 struct ceph_rw_context *rw_ctx;
497 int rc = 0;
498 int max = 0;
499
500 if (ceph_inode(inode)->i_inline_version != CEPH_INLINE_NONE)
501 return -EINVAL;
502
503 rc = ceph_readpages_from_fscache(mapping->host, mapping, page_list,
504 &nr_pages);
505
506 if (rc == 0)
507 goto out;
508
509 rw_ctx = ceph_find_rw_context(fi);
510 max = fsc->mount_options->rsize >> PAGE_SHIFT;
511 dout("readpages %p file %p ctx %p nr_pages %d max %d\n",
512 inode, file, rw_ctx, nr_pages, max);
513 while (!list_empty(page_list)) {
514 rc = start_read(inode, rw_ctx, page_list, max);
515 if (rc < 0)
516 goto out;
517 }
518out:
519 ceph_fscache_readpages_cancel(inode, page_list);
520
521 dout("readpages %p file %p ret %d\n", inode, file, rc);
522 return rc;
523}
524
525struct ceph_writeback_ctl
526{
527 loff_t i_size;
528 u64 truncate_size;
529 u32 truncate_seq;
530 bool size_stable;
531 bool head_snapc;
532};
533
534/*
535 * Get ref for the oldest snapc for an inode with dirty data... that is, the
536 * only snap context we are allowed to write back.
537 */
538static struct ceph_snap_context *
539get_oldest_context(struct inode *inode, struct ceph_writeback_ctl *ctl,
540 struct ceph_snap_context *page_snapc)
541{
542 struct ceph_inode_info *ci = ceph_inode(inode);
543 struct ceph_snap_context *snapc = NULL;
544 struct ceph_cap_snap *capsnap = NULL;
545
546 spin_lock(&ci->i_ceph_lock);
547 list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) {
548 dout(" cap_snap %p snapc %p has %d dirty pages\n", capsnap,
549 capsnap->context, capsnap->dirty_pages);
550 if (!capsnap->dirty_pages)
551 continue;
552
553 /* get i_size, truncate_{seq,size} for page_snapc? */
554 if (snapc && capsnap->context != page_snapc)
555 continue;
556
557 if (ctl) {
558 if (capsnap->writing) {
559 ctl->i_size = i_size_read(inode);
560 ctl->size_stable = false;
561 } else {
562 ctl->i_size = capsnap->size;
563 ctl->size_stable = true;
564 }
565 ctl->truncate_size = capsnap->truncate_size;
566 ctl->truncate_seq = capsnap->truncate_seq;
567 ctl->head_snapc = false;
568 }
569
570 if (snapc)
571 break;
572
573 snapc = ceph_get_snap_context(capsnap->context);
574 if (!page_snapc ||
575 page_snapc == snapc ||
576 page_snapc->seq > snapc->seq)
577 break;
578 }
579 if (!snapc && ci->i_wrbuffer_ref_head) {
580 snapc = ceph_get_snap_context(ci->i_head_snapc);
581 dout(" head snapc %p has %d dirty pages\n",
582 snapc, ci->i_wrbuffer_ref_head);
583 if (ctl) {
584 ctl->i_size = i_size_read(inode);
585 ctl->truncate_size = ci->i_truncate_size;
586 ctl->truncate_seq = ci->i_truncate_seq;
587 ctl->size_stable = false;
588 ctl->head_snapc = true;
589 }
590 }
591 spin_unlock(&ci->i_ceph_lock);
592 return snapc;
593}
594
595static u64 get_writepages_data_length(struct inode *inode,
596 struct page *page, u64 start)
597{
598 struct ceph_inode_info *ci = ceph_inode(inode);
599 struct ceph_snap_context *snapc = page_snap_context(page);
600 struct ceph_cap_snap *capsnap = NULL;
601 u64 end = i_size_read(inode);
602
603 if (snapc != ci->i_head_snapc) {
604 bool found = false;
605 spin_lock(&ci->i_ceph_lock);
606 list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) {
607 if (capsnap->context == snapc) {
608 if (!capsnap->writing)
609 end = capsnap->size;
610 found = true;
611 break;
612 }
613 }
614 spin_unlock(&ci->i_ceph_lock);
615 WARN_ON(!found);
616 }
617 if (end > page_offset(page) + PAGE_SIZE)
618 end = page_offset(page) + PAGE_SIZE;
619 return end > start ? end - start : 0;
620}
621
622/*
623 * do a synchronous write on N pages
624 */
625static int ceph_sync_writepages(struct ceph_fs_client *fsc,
626 struct ceph_vino vino,
627 struct ceph_file_layout *layout,
628 struct ceph_snap_context *snapc,
629 u64 off, u64 len,
630 u32 truncate_seq, u64 truncate_size,
631 struct timespec64 *mtime,
632 struct page **pages, int num_pages)
633{
634 struct ceph_osd_client *osdc = &fsc->client->osdc;
635 struct ceph_osd_request *req;
636 int rc = 0;
637 int page_align = off & ~PAGE_MASK;
638
639 req = ceph_osdc_new_request(osdc, layout, vino, off, &len, 0, 1,
640 CEPH_OSD_OP_WRITE, CEPH_OSD_FLAG_WRITE,
641 snapc, truncate_seq, truncate_size,
642 true);
643 if (IS_ERR(req))
644 return PTR_ERR(req);
645
646 /* it may be a short write due to an object boundary */
647 osd_req_op_extent_osd_data_pages(req, 0, pages, len, page_align,
648 false, false);
649 dout("writepages %llu~%llu (%llu bytes)\n", off, len, len);
650
651 req->r_mtime = *mtime;
652 rc = ceph_osdc_start_request(osdc, req, true);
653 if (!rc)
654 rc = ceph_osdc_wait_request(osdc, req);
655
656 ceph_update_write_latency(&fsc->mdsc->metric, req->r_start_latency,
657 req->r_end_latency, rc);
658
659 ceph_osdc_put_request(req);
660 if (rc == 0)
661 rc = len;
662 dout("writepages result %d\n", rc);
663 return rc;
664}
665
666/*
667 * Write a single page, but leave the page locked.
668 *
669 * If we get a write error, mark the mapping for error, but still adjust the
670 * dirty page accounting (i.e., page is no longer dirty).
671 */
672static int writepage_nounlock(struct page *page, struct writeback_control *wbc)
673{
674 struct inode *inode;
675 struct ceph_inode_info *ci;
676 struct ceph_fs_client *fsc;
677 struct ceph_snap_context *snapc, *oldest;
678 loff_t page_off = page_offset(page);
679 int err, len = PAGE_SIZE;
680 struct ceph_writeback_ctl ceph_wbc;
681
682 dout("writepage %p idx %lu\n", page, page->index);
683
684 inode = page->mapping->host;
685 ci = ceph_inode(inode);
686 fsc = ceph_inode_to_client(inode);
687
688 /* verify this is a writeable snap context */
689 snapc = page_snap_context(page);
690 if (!snapc) {
691 dout("writepage %p page %p not dirty?\n", inode, page);
692 return 0;
693 }
694 oldest = get_oldest_context(inode, &ceph_wbc, snapc);
695 if (snapc->seq > oldest->seq) {
696 dout("writepage %p page %p snapc %p not writeable - noop\n",
697 inode, page, snapc);
698 /* we should only noop if called by kswapd */
699 WARN_ON(!(current->flags & PF_MEMALLOC));
700 ceph_put_snap_context(oldest);
701 redirty_page_for_writepage(wbc, page);
702 return 0;
703 }
704 ceph_put_snap_context(oldest);
705
706 /* is this a partial page at end of file? */
707 if (page_off >= ceph_wbc.i_size) {
708 dout("%p page eof %llu\n", page, ceph_wbc.i_size);
709 page->mapping->a_ops->invalidatepage(page, 0, PAGE_SIZE);
710 return 0;
711 }
712
713 if (ceph_wbc.i_size < page_off + len)
714 len = ceph_wbc.i_size - page_off;
715
716 dout("writepage %p page %p index %lu on %llu~%u snapc %p seq %lld\n",
717 inode, page, page->index, page_off, len, snapc, snapc->seq);
718
719 if (atomic_long_inc_return(&fsc->writeback_count) >
720 CONGESTION_ON_THRESH(fsc->mount_options->congestion_kb))
721 set_bdi_congested(inode_to_bdi(inode), BLK_RW_ASYNC);
722
723 set_page_writeback(page);
724 err = ceph_sync_writepages(fsc, ceph_vino(inode),
725 &ci->i_layout, snapc, page_off, len,
726 ceph_wbc.truncate_seq,
727 ceph_wbc.truncate_size,
728 &inode->i_mtime, &page, 1);
729 if (err < 0) {
730 struct writeback_control tmp_wbc;
731 if (!wbc)
732 wbc = &tmp_wbc;
733 if (err == -ERESTARTSYS) {
734 /* killed by SIGKILL */
735 dout("writepage interrupted page %p\n", page);
736 redirty_page_for_writepage(wbc, page);
737 end_page_writeback(page);
738 return err;
739 }
740 if (err == -EBLACKLISTED)
741 fsc->blacklisted = true;
742 dout("writepage setting page/mapping error %d %p\n",
743 err, page);
744 mapping_set_error(&inode->i_data, err);
745 wbc->pages_skipped++;
746 } else {
747 dout("writepage cleaned page %p\n", page);
748 err = 0; /* vfs expects us to return 0 */
749 }
750 page->private = 0;
751 ClearPagePrivate(page);
752 end_page_writeback(page);
753 ceph_put_wrbuffer_cap_refs(ci, 1, snapc);
754 ceph_put_snap_context(snapc); /* page's reference */
755
756 if (atomic_long_dec_return(&fsc->writeback_count) <
757 CONGESTION_OFF_THRESH(fsc->mount_options->congestion_kb))
758 clear_bdi_congested(inode_to_bdi(inode), BLK_RW_ASYNC);
759
760 return err;
761}
762
763static int ceph_writepage(struct page *page, struct writeback_control *wbc)
764{
765 int err;
766 struct inode *inode = page->mapping->host;
767 BUG_ON(!inode);
768 ihold(inode);
769 err = writepage_nounlock(page, wbc);
770 if (err == -ERESTARTSYS) {
771 /* direct memory reclaimer was killed by SIGKILL. return 0
772 * to prevent caller from setting mapping/page error */
773 err = 0;
774 }
775 unlock_page(page);
776 iput(inode);
777 return err;
778}
779
780/*
781 * async writeback completion handler.
782 *
783 * If we get an error, set the mapping error bit, but not the individual
784 * page error bits.
785 */
786static void writepages_finish(struct ceph_osd_request *req)
787{
788 struct inode *inode = req->r_inode;
789 struct ceph_inode_info *ci = ceph_inode(inode);
790 struct ceph_osd_data *osd_data;
791 struct page *page;
792 int num_pages, total_pages = 0;
793 int i, j;
794 int rc = req->r_result;
795 struct ceph_snap_context *snapc = req->r_snapc;
796 struct address_space *mapping = inode->i_mapping;
797 struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
798 bool remove_page;
799
800 dout("writepages_finish %p rc %d\n", inode, rc);
801 if (rc < 0) {
802 mapping_set_error(mapping, rc);
803 ceph_set_error_write(ci);
804 if (rc == -EBLACKLISTED)
805 fsc->blacklisted = true;
806 } else {
807 ceph_clear_error_write(ci);
808 }
809
810 ceph_update_write_latency(&fsc->mdsc->metric, req->r_start_latency,
811 req->r_end_latency, rc);
812
813 /*
814 * We lost the cache cap, need to truncate the page before
815 * it is unlocked, otherwise we'd truncate it later in the
816 * page truncation thread, possibly losing some data that
817 * raced its way in
818 */
819 remove_page = !(ceph_caps_issued(ci) &
820 (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO));
821
822 /* clean all pages */
823 for (i = 0; i < req->r_num_ops; i++) {
824 if (req->r_ops[i].op != CEPH_OSD_OP_WRITE)
825 break;
826
827 osd_data = osd_req_op_extent_osd_data(req, i);
828 BUG_ON(osd_data->type != CEPH_OSD_DATA_TYPE_PAGES);
829 num_pages = calc_pages_for((u64)osd_data->alignment,
830 (u64)osd_data->length);
831 total_pages += num_pages;
832 for (j = 0; j < num_pages; j++) {
833 page = osd_data->pages[j];
834 BUG_ON(!page);
835 WARN_ON(!PageUptodate(page));
836
837 if (atomic_long_dec_return(&fsc->writeback_count) <
838 CONGESTION_OFF_THRESH(
839 fsc->mount_options->congestion_kb))
840 clear_bdi_congested(inode_to_bdi(inode),
841 BLK_RW_ASYNC);
842
843 ceph_put_snap_context(page_snap_context(page));
844 page->private = 0;
845 ClearPagePrivate(page);
846 dout("unlocking %p\n", page);
847 end_page_writeback(page);
848
849 if (remove_page)
850 generic_error_remove_page(inode->i_mapping,
851 page);
852
853 unlock_page(page);
854 }
855 dout("writepages_finish %p wrote %llu bytes cleaned %d pages\n",
856 inode, osd_data->length, rc >= 0 ? num_pages : 0);
857
858 release_pages(osd_data->pages, num_pages);
859 }
860
861 ceph_put_wrbuffer_cap_refs(ci, total_pages, snapc);
862
863 osd_data = osd_req_op_extent_osd_data(req, 0);
864 if (osd_data->pages_from_pool)
865 mempool_free(osd_data->pages, ceph_wb_pagevec_pool);
866 else
867 kfree(osd_data->pages);
868 ceph_osdc_put_request(req);
869}
870
871/*
872 * initiate async writeback
873 */
874static int ceph_writepages_start(struct address_space *mapping,
875 struct writeback_control *wbc)
876{
877 struct inode *inode = mapping->host;
878 struct ceph_inode_info *ci = ceph_inode(inode);
879 struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
880 struct ceph_vino vino = ceph_vino(inode);
881 pgoff_t index, start_index, end = -1;
882 struct ceph_snap_context *snapc = NULL, *last_snapc = NULL, *pgsnapc;
883 struct pagevec pvec;
884 int rc = 0;
885 unsigned int wsize = i_blocksize(inode);
886 struct ceph_osd_request *req = NULL;
887 struct ceph_writeback_ctl ceph_wbc;
888 bool should_loop, range_whole = false;
889 bool done = false;
890
891 dout("writepages_start %p (mode=%s)\n", inode,
892 wbc->sync_mode == WB_SYNC_NONE ? "NONE" :
893 (wbc->sync_mode == WB_SYNC_ALL ? "ALL" : "HOLD"));
894
895 if (READ_ONCE(fsc->mount_state) == CEPH_MOUNT_SHUTDOWN) {
896 if (ci->i_wrbuffer_ref > 0) {
897 pr_warn_ratelimited(
898 "writepage_start %p %lld forced umount\n",
899 inode, ceph_ino(inode));
900 }
901 mapping_set_error(mapping, -EIO);
902 return -EIO; /* we're in a forced umount, don't write! */
903 }
904 if (fsc->mount_options->wsize < wsize)
905 wsize = fsc->mount_options->wsize;
906
907 pagevec_init(&pvec);
908
909 start_index = wbc->range_cyclic ? mapping->writeback_index : 0;
910 index = start_index;
911
912retry:
913 /* find oldest snap context with dirty data */
914 snapc = get_oldest_context(inode, &ceph_wbc, NULL);
915 if (!snapc) {
916 /* hmm, why does writepages get called when there
917 is no dirty data? */
918 dout(" no snap context with dirty data?\n");
919 goto out;
920 }
921 dout(" oldest snapc is %p seq %lld (%d snaps)\n",
922 snapc, snapc->seq, snapc->num_snaps);
923
924 should_loop = false;
925 if (ceph_wbc.head_snapc && snapc != last_snapc) {
926 /* where to start/end? */
927 if (wbc->range_cyclic) {
928 index = start_index;
929 end = -1;
930 if (index > 0)
931 should_loop = true;
932 dout(" cyclic, start at %lu\n", index);
933 } else {
934 index = wbc->range_start >> PAGE_SHIFT;
935 end = wbc->range_end >> PAGE_SHIFT;
936 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
937 range_whole = true;
938 dout(" not cyclic, %lu to %lu\n", index, end);
939 }
940 } else if (!ceph_wbc.head_snapc) {
941 /* Do not respect wbc->range_{start,end}. Dirty pages
942 * in that range can be associated with newer snapc.
943 * They are not writeable until we write all dirty pages
944 * associated with 'snapc' get written */
945 if (index > 0)
946 should_loop = true;
947 dout(" non-head snapc, range whole\n");
948 }
949
950 ceph_put_snap_context(last_snapc);
951 last_snapc = snapc;
952
953 while (!done && index <= end) {
954 int num_ops = 0, op_idx;
955 unsigned i, pvec_pages, max_pages, locked_pages = 0;
956 struct page **pages = NULL, **data_pages;
957 struct page *page;
958 pgoff_t strip_unit_end = 0;
959 u64 offset = 0, len = 0;
960 bool from_pool = false;
961
962 max_pages = wsize >> PAGE_SHIFT;
963
964get_more_pages:
965 pvec_pages = pagevec_lookup_range_nr_tag(&pvec, mapping, &index,
966 end, PAGECACHE_TAG_DIRTY,
967 max_pages - locked_pages);
968 dout("pagevec_lookup_range_tag got %d\n", pvec_pages);
969 if (!pvec_pages && !locked_pages)
970 break;
971 for (i = 0; i < pvec_pages && locked_pages < max_pages; i++) {
972 page = pvec.pages[i];
973 dout("? %p idx %lu\n", page, page->index);
974 if (locked_pages == 0)
975 lock_page(page); /* first page */
976 else if (!trylock_page(page))
977 break;
978
979 /* only dirty pages, or our accounting breaks */
980 if (unlikely(!PageDirty(page)) ||
981 unlikely(page->mapping != mapping)) {
982 dout("!dirty or !mapping %p\n", page);
983 unlock_page(page);
984 continue;
985 }
986 /* only if matching snap context */
987 pgsnapc = page_snap_context(page);
988 if (pgsnapc != snapc) {
989 dout("page snapc %p %lld != oldest %p %lld\n",
990 pgsnapc, pgsnapc->seq, snapc, snapc->seq);
991 if (!should_loop &&
992 !ceph_wbc.head_snapc &&
993 wbc->sync_mode != WB_SYNC_NONE)
994 should_loop = true;
995 unlock_page(page);
996 continue;
997 }
998 if (page_offset(page) >= ceph_wbc.i_size) {
999 dout("%p page eof %llu\n",
1000 page, ceph_wbc.i_size);
1001 if ((ceph_wbc.size_stable ||
1002 page_offset(page) >= i_size_read(inode)) &&
1003 clear_page_dirty_for_io(page))
1004 mapping->a_ops->invalidatepage(page,
1005 0, PAGE_SIZE);
1006 unlock_page(page);
1007 continue;
1008 }
1009 if (strip_unit_end && (page->index > strip_unit_end)) {
1010 dout("end of strip unit %p\n", page);
1011 unlock_page(page);
1012 break;
1013 }
1014 if (PageWriteback(page)) {
1015 if (wbc->sync_mode == WB_SYNC_NONE) {
1016 dout("%p under writeback\n", page);
1017 unlock_page(page);
1018 continue;
1019 }
1020 dout("waiting on writeback %p\n", page);
1021 wait_on_page_writeback(page);
1022 }
1023
1024 if (!clear_page_dirty_for_io(page)) {
1025 dout("%p !clear_page_dirty_for_io\n", page);
1026 unlock_page(page);
1027 continue;
1028 }
1029
1030 /*
1031 * We have something to write. If this is
1032 * the first locked page this time through,
1033 * calculate max possinle write size and
1034 * allocate a page array
1035 */
1036 if (locked_pages == 0) {
1037 u64 objnum;
1038 u64 objoff;
1039 u32 xlen;
1040
1041 /* prepare async write request */
1042 offset = (u64)page_offset(page);
1043 ceph_calc_file_object_mapping(&ci->i_layout,
1044 offset, wsize,
1045 &objnum, &objoff,
1046 &xlen);
1047 len = xlen;
1048
1049 num_ops = 1;
1050 strip_unit_end = page->index +
1051 ((len - 1) >> PAGE_SHIFT);
1052
1053 BUG_ON(pages);
1054 max_pages = calc_pages_for(0, (u64)len);
1055 pages = kmalloc_array(max_pages,
1056 sizeof(*pages),
1057 GFP_NOFS);
1058 if (!pages) {
1059 from_pool = true;
1060 pages = mempool_alloc(ceph_wb_pagevec_pool, GFP_NOFS);
1061 BUG_ON(!pages);
1062 }
1063
1064 len = 0;
1065 } else if (page->index !=
1066 (offset + len) >> PAGE_SHIFT) {
1067 if (num_ops >= (from_pool ? CEPH_OSD_SLAB_OPS :
1068 CEPH_OSD_MAX_OPS)) {
1069 redirty_page_for_writepage(wbc, page);
1070 unlock_page(page);
1071 break;
1072 }
1073
1074 num_ops++;
1075 offset = (u64)page_offset(page);
1076 len = 0;
1077 }
1078
1079 /* note position of first page in pvec */
1080 dout("%p will write page %p idx %lu\n",
1081 inode, page, page->index);
1082
1083 if (atomic_long_inc_return(&fsc->writeback_count) >
1084 CONGESTION_ON_THRESH(
1085 fsc->mount_options->congestion_kb)) {
1086 set_bdi_congested(inode_to_bdi(inode),
1087 BLK_RW_ASYNC);
1088 }
1089
1090
1091 pages[locked_pages++] = page;
1092 pvec.pages[i] = NULL;
1093
1094 len += PAGE_SIZE;
1095 }
1096
1097 /* did we get anything? */
1098 if (!locked_pages)
1099 goto release_pvec_pages;
1100 if (i) {
1101 unsigned j, n = 0;
1102 /* shift unused page to beginning of pvec */
1103 for (j = 0; j < pvec_pages; j++) {
1104 if (!pvec.pages[j])
1105 continue;
1106 if (n < j)
1107 pvec.pages[n] = pvec.pages[j];
1108 n++;
1109 }
1110 pvec.nr = n;
1111
1112 if (pvec_pages && i == pvec_pages &&
1113 locked_pages < max_pages) {
1114 dout("reached end pvec, trying for more\n");
1115 pagevec_release(&pvec);
1116 goto get_more_pages;
1117 }
1118 }
1119
1120new_request:
1121 offset = page_offset(pages[0]);
1122 len = wsize;
1123
1124 req = ceph_osdc_new_request(&fsc->client->osdc,
1125 &ci->i_layout, vino,
1126 offset, &len, 0, num_ops,
1127 CEPH_OSD_OP_WRITE, CEPH_OSD_FLAG_WRITE,
1128 snapc, ceph_wbc.truncate_seq,
1129 ceph_wbc.truncate_size, false);
1130 if (IS_ERR(req)) {
1131 req = ceph_osdc_new_request(&fsc->client->osdc,
1132 &ci->i_layout, vino,
1133 offset, &len, 0,
1134 min(num_ops,
1135 CEPH_OSD_SLAB_OPS),
1136 CEPH_OSD_OP_WRITE,
1137 CEPH_OSD_FLAG_WRITE,
1138 snapc, ceph_wbc.truncate_seq,
1139 ceph_wbc.truncate_size, true);
1140 BUG_ON(IS_ERR(req));
1141 }
1142 BUG_ON(len < page_offset(pages[locked_pages - 1]) +
1143 PAGE_SIZE - offset);
1144
1145 req->r_callback = writepages_finish;
1146 req->r_inode = inode;
1147
1148 /* Format the osd request message and submit the write */
1149 len = 0;
1150 data_pages = pages;
1151 op_idx = 0;
1152 for (i = 0; i < locked_pages; i++) {
1153 u64 cur_offset = page_offset(pages[i]);
1154 if (offset + len != cur_offset) {
1155 if (op_idx + 1 == req->r_num_ops)
1156 break;
1157 osd_req_op_extent_dup_last(req, op_idx,
1158 cur_offset - offset);
1159 dout("writepages got pages at %llu~%llu\n",
1160 offset, len);
1161 osd_req_op_extent_osd_data_pages(req, op_idx,
1162 data_pages, len, 0,
1163 from_pool, false);
1164 osd_req_op_extent_update(req, op_idx, len);
1165
1166 len = 0;
1167 offset = cur_offset;
1168 data_pages = pages + i;
1169 op_idx++;
1170 }
1171
1172 set_page_writeback(pages[i]);
1173 len += PAGE_SIZE;
1174 }
1175
1176 if (ceph_wbc.size_stable) {
1177 len = min(len, ceph_wbc.i_size - offset);
1178 } else if (i == locked_pages) {
1179 /* writepages_finish() clears writeback pages
1180 * according to the data length, so make sure
1181 * data length covers all locked pages */
1182 u64 min_len = len + 1 - PAGE_SIZE;
1183 len = get_writepages_data_length(inode, pages[i - 1],
1184 offset);
1185 len = max(len, min_len);
1186 }
1187 dout("writepages got pages at %llu~%llu\n", offset, len);
1188
1189 osd_req_op_extent_osd_data_pages(req, op_idx, data_pages, len,
1190 0, from_pool, false);
1191 osd_req_op_extent_update(req, op_idx, len);
1192
1193 BUG_ON(op_idx + 1 != req->r_num_ops);
1194
1195 from_pool = false;
1196 if (i < locked_pages) {
1197 BUG_ON(num_ops <= req->r_num_ops);
1198 num_ops -= req->r_num_ops;
1199 locked_pages -= i;
1200
1201 /* allocate new pages array for next request */
1202 data_pages = pages;
1203 pages = kmalloc_array(locked_pages, sizeof(*pages),
1204 GFP_NOFS);
1205 if (!pages) {
1206 from_pool = true;
1207 pages = mempool_alloc(ceph_wb_pagevec_pool, GFP_NOFS);
1208 BUG_ON(!pages);
1209 }
1210 memcpy(pages, data_pages + i,
1211 locked_pages * sizeof(*pages));
1212 memset(data_pages + i, 0,
1213 locked_pages * sizeof(*pages));
1214 } else {
1215 BUG_ON(num_ops != req->r_num_ops);
1216 index = pages[i - 1]->index + 1;
1217 /* request message now owns the pages array */
1218 pages = NULL;
1219 }
1220
1221 req->r_mtime = inode->i_mtime;
1222 rc = ceph_osdc_start_request(&fsc->client->osdc, req, true);
1223 BUG_ON(rc);
1224 req = NULL;
1225
1226 wbc->nr_to_write -= i;
1227 if (pages)
1228 goto new_request;
1229
1230 /*
1231 * We stop writing back only if we are not doing
1232 * integrity sync. In case of integrity sync we have to
1233 * keep going until we have written all the pages
1234 * we tagged for writeback prior to entering this loop.
1235 */
1236 if (wbc->nr_to_write <= 0 && wbc->sync_mode == WB_SYNC_NONE)
1237 done = true;
1238
1239release_pvec_pages:
1240 dout("pagevec_release on %d pages (%p)\n", (int)pvec.nr,
1241 pvec.nr ? pvec.pages[0] : NULL);
1242 pagevec_release(&pvec);
1243 }
1244
1245 if (should_loop && !done) {
1246 /* more to do; loop back to beginning of file */
1247 dout("writepages looping back to beginning of file\n");
1248 end = start_index - 1; /* OK even when start_index == 0 */
1249
1250 /* to write dirty pages associated with next snapc,
1251 * we need to wait until current writes complete */
1252 if (wbc->sync_mode != WB_SYNC_NONE &&
1253 start_index == 0 && /* all dirty pages were checked */
1254 !ceph_wbc.head_snapc) {
1255 struct page *page;
1256 unsigned i, nr;
1257 index = 0;
1258 while ((index <= end) &&
1259 (nr = pagevec_lookup_tag(&pvec, mapping, &index,
1260 PAGECACHE_TAG_WRITEBACK))) {
1261 for (i = 0; i < nr; i++) {
1262 page = pvec.pages[i];
1263 if (page_snap_context(page) != snapc)
1264 continue;
1265 wait_on_page_writeback(page);
1266 }
1267 pagevec_release(&pvec);
1268 cond_resched();
1269 }
1270 }
1271
1272 start_index = 0;
1273 index = 0;
1274 goto retry;
1275 }
1276
1277 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
1278 mapping->writeback_index = index;
1279
1280out:
1281 ceph_osdc_put_request(req);
1282 ceph_put_snap_context(last_snapc);
1283 dout("writepages dend - startone, rc = %d\n", rc);
1284 return rc;
1285}
1286
1287
1288
1289/*
1290 * See if a given @snapc is either writeable, or already written.
1291 */
1292static int context_is_writeable_or_written(struct inode *inode,
1293 struct ceph_snap_context *snapc)
1294{
1295 struct ceph_snap_context *oldest = get_oldest_context(inode, NULL, NULL);
1296 int ret = !oldest || snapc->seq <= oldest->seq;
1297
1298 ceph_put_snap_context(oldest);
1299 return ret;
1300}
1301
1302/*
1303 * We are only allowed to write into/dirty the page if the page is
1304 * clean, or already dirty within the same snap context.
1305 *
1306 * called with page locked.
1307 * return success with page locked,
1308 * or any failure (incl -EAGAIN) with page unlocked.
1309 */
1310static int ceph_update_writeable_page(struct file *file,
1311 loff_t pos, unsigned len,
1312 struct page *page)
1313{
1314 struct inode *inode = file_inode(file);
1315 struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
1316 struct ceph_inode_info *ci = ceph_inode(inode);
1317 loff_t page_off = pos & PAGE_MASK;
1318 int pos_in_page = pos & ~PAGE_MASK;
1319 int end_in_page = pos_in_page + len;
1320 loff_t i_size;
1321 int r;
1322 struct ceph_snap_context *snapc, *oldest;
1323
1324 if (READ_ONCE(fsc->mount_state) == CEPH_MOUNT_SHUTDOWN) {
1325 dout(" page %p forced umount\n", page);
1326 unlock_page(page);
1327 return -EIO;
1328 }
1329
1330retry_locked:
1331 /* writepages currently holds page lock, but if we change that later, */
1332 wait_on_page_writeback(page);
1333
1334 snapc = page_snap_context(page);
1335 if (snapc && snapc != ci->i_head_snapc) {
1336 /*
1337 * this page is already dirty in another (older) snap
1338 * context! is it writeable now?
1339 */
1340 oldest = get_oldest_context(inode, NULL, NULL);
1341 if (snapc->seq > oldest->seq) {
1342 ceph_put_snap_context(oldest);
1343 dout(" page %p snapc %p not current or oldest\n",
1344 page, snapc);
1345 /*
1346 * queue for writeback, and wait for snapc to
1347 * be writeable or written
1348 */
1349 snapc = ceph_get_snap_context(snapc);
1350 unlock_page(page);
1351 ceph_queue_writeback(inode);
1352 r = wait_event_killable(ci->i_cap_wq,
1353 context_is_writeable_or_written(inode, snapc));
1354 ceph_put_snap_context(snapc);
1355 if (r == -ERESTARTSYS)
1356 return r;
1357 return -EAGAIN;
1358 }
1359 ceph_put_snap_context(oldest);
1360
1361 /* yay, writeable, do it now (without dropping page lock) */
1362 dout(" page %p snapc %p not current, but oldest\n",
1363 page, snapc);
1364 if (!clear_page_dirty_for_io(page))
1365 goto retry_locked;
1366 r = writepage_nounlock(page, NULL);
1367 if (r < 0)
1368 goto fail_unlock;
1369 goto retry_locked;
1370 }
1371
1372 if (PageUptodate(page)) {
1373 dout(" page %p already uptodate\n", page);
1374 return 0;
1375 }
1376
1377 /* full page? */
1378 if (pos_in_page == 0 && len == PAGE_SIZE)
1379 return 0;
1380
1381 /* past end of file? */
1382 i_size = i_size_read(inode);
1383
1384 if (page_off >= i_size ||
1385 (pos_in_page == 0 && (pos+len) >= i_size &&
1386 end_in_page - pos_in_page != PAGE_SIZE)) {
1387 dout(" zeroing %p 0 - %d and %d - %d\n",
1388 page, pos_in_page, end_in_page, (int)PAGE_SIZE);
1389 zero_user_segments(page,
1390 0, pos_in_page,
1391 end_in_page, PAGE_SIZE);
1392 return 0;
1393 }
1394
1395 /* we need to read it. */
1396 r = ceph_do_readpage(file, page);
1397 if (r < 0) {
1398 if (r == -EINPROGRESS)
1399 return -EAGAIN;
1400 goto fail_unlock;
1401 }
1402 goto retry_locked;
1403fail_unlock:
1404 unlock_page(page);
1405 return r;
1406}
1407
1408/*
1409 * We are only allowed to write into/dirty the page if the page is
1410 * clean, or already dirty within the same snap context.
1411 */
1412static int ceph_write_begin(struct file *file, struct address_space *mapping,
1413 loff_t pos, unsigned len, unsigned flags,
1414 struct page **pagep, void **fsdata)
1415{
1416 struct inode *inode = file_inode(file);
1417 struct page *page;
1418 pgoff_t index = pos >> PAGE_SHIFT;
1419 int r;
1420
1421 do {
1422 /* get a page */
1423 page = grab_cache_page_write_begin(mapping, index, 0);
1424 if (!page)
1425 return -ENOMEM;
1426
1427 dout("write_begin file %p inode %p page %p %d~%d\n", file,
1428 inode, page, (int)pos, (int)len);
1429
1430 r = ceph_update_writeable_page(file, pos, len, page);
1431 if (r < 0)
1432 put_page(page);
1433 else
1434 *pagep = page;
1435 } while (r == -EAGAIN);
1436
1437 return r;
1438}
1439
1440/*
1441 * we don't do anything in here that simple_write_end doesn't do
1442 * except adjust dirty page accounting
1443 */
1444static int ceph_write_end(struct file *file, struct address_space *mapping,
1445 loff_t pos, unsigned len, unsigned copied,
1446 struct page *page, void *fsdata)
1447{
1448 struct inode *inode = file_inode(file);
1449 bool check_cap = false;
1450
1451 dout("write_end file %p inode %p page %p %d~%d (%d)\n", file,
1452 inode, page, (int)pos, (int)copied, (int)len);
1453
1454 /* zero the stale part of the page if we did a short copy */
1455 if (!PageUptodate(page)) {
1456 if (copied < len) {
1457 copied = 0;
1458 goto out;
1459 }
1460 SetPageUptodate(page);
1461 }
1462
1463 /* did file size increase? */
1464 if (pos+copied > i_size_read(inode))
1465 check_cap = ceph_inode_set_size(inode, pos+copied);
1466
1467 set_page_dirty(page);
1468
1469out:
1470 unlock_page(page);
1471 put_page(page);
1472
1473 if (check_cap)
1474 ceph_check_caps(ceph_inode(inode), CHECK_CAPS_AUTHONLY, NULL);
1475
1476 return copied;
1477}
1478
1479/*
1480 * we set .direct_IO to indicate direct io is supported, but since we
1481 * intercept O_DIRECT reads and writes early, this function should
1482 * never get called.
1483 */
1484static ssize_t ceph_direct_io(struct kiocb *iocb, struct iov_iter *iter)
1485{
1486 WARN_ON(1);
1487 return -EINVAL;
1488}
1489
1490const struct address_space_operations ceph_aops = {
1491 .readpage = ceph_readpage,
1492 .readpages = ceph_readpages,
1493 .writepage = ceph_writepage,
1494 .writepages = ceph_writepages_start,
1495 .write_begin = ceph_write_begin,
1496 .write_end = ceph_write_end,
1497 .set_page_dirty = ceph_set_page_dirty,
1498 .invalidatepage = ceph_invalidatepage,
1499 .releasepage = ceph_releasepage,
1500 .direct_IO = ceph_direct_io,
1501};
1502
1503static void ceph_block_sigs(sigset_t *oldset)
1504{
1505 sigset_t mask;
1506 siginitsetinv(&mask, sigmask(SIGKILL));
1507 sigprocmask(SIG_BLOCK, &mask, oldset);
1508}
1509
1510static void ceph_restore_sigs(sigset_t *oldset)
1511{
1512 sigprocmask(SIG_SETMASK, oldset, NULL);
1513}
1514
1515/*
1516 * vm ops
1517 */
1518static vm_fault_t ceph_filemap_fault(struct vm_fault *vmf)
1519{
1520 struct vm_area_struct *vma = vmf->vma;
1521 struct inode *inode = file_inode(vma->vm_file);
1522 struct ceph_inode_info *ci = ceph_inode(inode);
1523 struct ceph_file_info *fi = vma->vm_file->private_data;
1524 struct page *pinned_page = NULL;
1525 loff_t off = vmf->pgoff << PAGE_SHIFT;
1526 int want, got, err;
1527 sigset_t oldset;
1528 vm_fault_t ret = VM_FAULT_SIGBUS;
1529
1530 ceph_block_sigs(&oldset);
1531
1532 dout("filemap_fault %p %llx.%llx %llu~%zd trying to get caps\n",
1533 inode, ceph_vinop(inode), off, (size_t)PAGE_SIZE);
1534 if (fi->fmode & CEPH_FILE_MODE_LAZY)
1535 want = CEPH_CAP_FILE_CACHE | CEPH_CAP_FILE_LAZYIO;
1536 else
1537 want = CEPH_CAP_FILE_CACHE;
1538
1539 got = 0;
1540 err = ceph_get_caps(vma->vm_file, CEPH_CAP_FILE_RD, want, -1,
1541 &got, &pinned_page);
1542 if (err < 0)
1543 goto out_restore;
1544
1545 dout("filemap_fault %p %llu~%zd got cap refs on %s\n",
1546 inode, off, (size_t)PAGE_SIZE, ceph_cap_string(got));
1547
1548 if ((got & (CEPH_CAP_FILE_CACHE | CEPH_CAP_FILE_LAZYIO)) ||
1549 ci->i_inline_version == CEPH_INLINE_NONE) {
1550 CEPH_DEFINE_RW_CONTEXT(rw_ctx, got);
1551 ceph_add_rw_context(fi, &rw_ctx);
1552 ret = filemap_fault(vmf);
1553 ceph_del_rw_context(fi, &rw_ctx);
1554 dout("filemap_fault %p %llu~%zd drop cap refs %s ret %x\n",
1555 inode, off, (size_t)PAGE_SIZE,
1556 ceph_cap_string(got), ret);
1557 } else
1558 err = -EAGAIN;
1559
1560 if (pinned_page)
1561 put_page(pinned_page);
1562 ceph_put_cap_refs(ci, got);
1563
1564 if (err != -EAGAIN)
1565 goto out_restore;
1566
1567 /* read inline data */
1568 if (off >= PAGE_SIZE) {
1569 /* does not support inline data > PAGE_SIZE */
1570 ret = VM_FAULT_SIGBUS;
1571 } else {
1572 struct address_space *mapping = inode->i_mapping;
1573 struct page *page = find_or_create_page(mapping, 0,
1574 mapping_gfp_constraint(mapping,
1575 ~__GFP_FS));
1576 if (!page) {
1577 ret = VM_FAULT_OOM;
1578 goto out_inline;
1579 }
1580 err = __ceph_do_getattr(inode, page,
1581 CEPH_STAT_CAP_INLINE_DATA, true);
1582 if (err < 0 || off >= i_size_read(inode)) {
1583 unlock_page(page);
1584 put_page(page);
1585 ret = vmf_error(err);
1586 goto out_inline;
1587 }
1588 if (err < PAGE_SIZE)
1589 zero_user_segment(page, err, PAGE_SIZE);
1590 else
1591 flush_dcache_page(page);
1592 SetPageUptodate(page);
1593 vmf->page = page;
1594 ret = VM_FAULT_MAJOR | VM_FAULT_LOCKED;
1595out_inline:
1596 dout("filemap_fault %p %llu~%zd read inline data ret %x\n",
1597 inode, off, (size_t)PAGE_SIZE, ret);
1598 }
1599out_restore:
1600 ceph_restore_sigs(&oldset);
1601 if (err < 0)
1602 ret = vmf_error(err);
1603
1604 return ret;
1605}
1606
1607/*
1608 * Reuse write_begin here for simplicity.
1609 */
1610static vm_fault_t ceph_page_mkwrite(struct vm_fault *vmf)
1611{
1612 struct vm_area_struct *vma = vmf->vma;
1613 struct inode *inode = file_inode(vma->vm_file);
1614 struct ceph_inode_info *ci = ceph_inode(inode);
1615 struct ceph_file_info *fi = vma->vm_file->private_data;
1616 struct ceph_cap_flush *prealloc_cf;
1617 struct page *page = vmf->page;
1618 loff_t off = page_offset(page);
1619 loff_t size = i_size_read(inode);
1620 size_t len;
1621 int want, got, err;
1622 sigset_t oldset;
1623 vm_fault_t ret = VM_FAULT_SIGBUS;
1624
1625 prealloc_cf = ceph_alloc_cap_flush();
1626 if (!prealloc_cf)
1627 return VM_FAULT_OOM;
1628
1629 sb_start_pagefault(inode->i_sb);
1630 ceph_block_sigs(&oldset);
1631
1632 if (ci->i_inline_version != CEPH_INLINE_NONE) {
1633 struct page *locked_page = NULL;
1634 if (off == 0) {
1635 lock_page(page);
1636 locked_page = page;
1637 }
1638 err = ceph_uninline_data(vma->vm_file, locked_page);
1639 if (locked_page)
1640 unlock_page(locked_page);
1641 if (err < 0)
1642 goto out_free;
1643 }
1644
1645 if (off + PAGE_SIZE <= size)
1646 len = PAGE_SIZE;
1647 else
1648 len = size & ~PAGE_MASK;
1649
1650 dout("page_mkwrite %p %llx.%llx %llu~%zd getting caps i_size %llu\n",
1651 inode, ceph_vinop(inode), off, len, size);
1652 if (fi->fmode & CEPH_FILE_MODE_LAZY)
1653 want = CEPH_CAP_FILE_BUFFER | CEPH_CAP_FILE_LAZYIO;
1654 else
1655 want = CEPH_CAP_FILE_BUFFER;
1656
1657 got = 0;
1658 err = ceph_get_caps(vma->vm_file, CEPH_CAP_FILE_WR, want, off + len,
1659 &got, NULL);
1660 if (err < 0)
1661 goto out_free;
1662
1663 dout("page_mkwrite %p %llu~%zd got cap refs on %s\n",
1664 inode, off, len, ceph_cap_string(got));
1665
1666 /* Update time before taking page lock */
1667 file_update_time(vma->vm_file);
1668 inode_inc_iversion_raw(inode);
1669
1670 do {
1671 lock_page(page);
1672
1673 if (page_mkwrite_check_truncate(page, inode) < 0) {
1674 unlock_page(page);
1675 ret = VM_FAULT_NOPAGE;
1676 break;
1677 }
1678
1679 err = ceph_update_writeable_page(vma->vm_file, off, len, page);
1680 if (err >= 0) {
1681 /* success. we'll keep the page locked. */
1682 set_page_dirty(page);
1683 ret = VM_FAULT_LOCKED;
1684 }
1685 } while (err == -EAGAIN);
1686
1687 if (ret == VM_FAULT_LOCKED ||
1688 ci->i_inline_version != CEPH_INLINE_NONE) {
1689 int dirty;
1690 spin_lock(&ci->i_ceph_lock);
1691 ci->i_inline_version = CEPH_INLINE_NONE;
1692 dirty = __ceph_mark_dirty_caps(ci, CEPH_CAP_FILE_WR,
1693 &prealloc_cf);
1694 spin_unlock(&ci->i_ceph_lock);
1695 if (dirty)
1696 __mark_inode_dirty(inode, dirty);
1697 }
1698
1699 dout("page_mkwrite %p %llu~%zd dropping cap refs on %s ret %x\n",
1700 inode, off, len, ceph_cap_string(got), ret);
1701 ceph_put_cap_refs(ci, got);
1702out_free:
1703 ceph_restore_sigs(&oldset);
1704 sb_end_pagefault(inode->i_sb);
1705 ceph_free_cap_flush(prealloc_cf);
1706 if (err < 0)
1707 ret = vmf_error(err);
1708 return ret;
1709}
1710
1711void ceph_fill_inline_data(struct inode *inode, struct page *locked_page,
1712 char *data, size_t len)
1713{
1714 struct address_space *mapping = inode->i_mapping;
1715 struct page *page;
1716
1717 if (locked_page) {
1718 page = locked_page;
1719 } else {
1720 if (i_size_read(inode) == 0)
1721 return;
1722 page = find_or_create_page(mapping, 0,
1723 mapping_gfp_constraint(mapping,
1724 ~__GFP_FS));
1725 if (!page)
1726 return;
1727 if (PageUptodate(page)) {
1728 unlock_page(page);
1729 put_page(page);
1730 return;
1731 }
1732 }
1733
1734 dout("fill_inline_data %p %llx.%llx len %zu locked_page %p\n",
1735 inode, ceph_vinop(inode), len, locked_page);
1736
1737 if (len > 0) {
1738 void *kaddr = kmap_atomic(page);
1739 memcpy(kaddr, data, len);
1740 kunmap_atomic(kaddr);
1741 }
1742
1743 if (page != locked_page) {
1744 if (len < PAGE_SIZE)
1745 zero_user_segment(page, len, PAGE_SIZE);
1746 else
1747 flush_dcache_page(page);
1748
1749 SetPageUptodate(page);
1750 unlock_page(page);
1751 put_page(page);
1752 }
1753}
1754
1755int ceph_uninline_data(struct file *filp, struct page *locked_page)
1756{
1757 struct inode *inode = file_inode(filp);
1758 struct ceph_inode_info *ci = ceph_inode(inode);
1759 struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
1760 struct ceph_osd_request *req;
1761 struct page *page = NULL;
1762 u64 len, inline_version;
1763 int err = 0;
1764 bool from_pagecache = false;
1765
1766 spin_lock(&ci->i_ceph_lock);
1767 inline_version = ci->i_inline_version;
1768 spin_unlock(&ci->i_ceph_lock);
1769
1770 dout("uninline_data %p %llx.%llx inline_version %llu\n",
1771 inode, ceph_vinop(inode), inline_version);
1772
1773 if (inline_version == 1 || /* initial version, no data */
1774 inline_version == CEPH_INLINE_NONE)
1775 goto out;
1776
1777 if (locked_page) {
1778 page = locked_page;
1779 WARN_ON(!PageUptodate(page));
1780 } else if (ceph_caps_issued(ci) &
1781 (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) {
1782 page = find_get_page(inode->i_mapping, 0);
1783 if (page) {
1784 if (PageUptodate(page)) {
1785 from_pagecache = true;
1786 lock_page(page);
1787 } else {
1788 put_page(page);
1789 page = NULL;
1790 }
1791 }
1792 }
1793
1794 if (page) {
1795 len = i_size_read(inode);
1796 if (len > PAGE_SIZE)
1797 len = PAGE_SIZE;
1798 } else {
1799 page = __page_cache_alloc(GFP_NOFS);
1800 if (!page) {
1801 err = -ENOMEM;
1802 goto out;
1803 }
1804 err = __ceph_do_getattr(inode, page,
1805 CEPH_STAT_CAP_INLINE_DATA, true);
1806 if (err < 0) {
1807 /* no inline data */
1808 if (err == -ENODATA)
1809 err = 0;
1810 goto out;
1811 }
1812 len = err;
1813 }
1814
1815 req = ceph_osdc_new_request(&fsc->client->osdc, &ci->i_layout,
1816 ceph_vino(inode), 0, &len, 0, 1,
1817 CEPH_OSD_OP_CREATE, CEPH_OSD_FLAG_WRITE,
1818 NULL, 0, 0, false);
1819 if (IS_ERR(req)) {
1820 err = PTR_ERR(req);
1821 goto out;
1822 }
1823
1824 req->r_mtime = inode->i_mtime;
1825 err = ceph_osdc_start_request(&fsc->client->osdc, req, false);
1826 if (!err)
1827 err = ceph_osdc_wait_request(&fsc->client->osdc, req);
1828 ceph_osdc_put_request(req);
1829 if (err < 0)
1830 goto out;
1831
1832 req = ceph_osdc_new_request(&fsc->client->osdc, &ci->i_layout,
1833 ceph_vino(inode), 0, &len, 1, 3,
1834 CEPH_OSD_OP_WRITE, CEPH_OSD_FLAG_WRITE,
1835 NULL, ci->i_truncate_seq,
1836 ci->i_truncate_size, false);
1837 if (IS_ERR(req)) {
1838 err = PTR_ERR(req);
1839 goto out;
1840 }
1841
1842 osd_req_op_extent_osd_data_pages(req, 1, &page, len, 0, false, false);
1843
1844 {
1845 __le64 xattr_buf = cpu_to_le64(inline_version);
1846 err = osd_req_op_xattr_init(req, 0, CEPH_OSD_OP_CMPXATTR,
1847 "inline_version", &xattr_buf,
1848 sizeof(xattr_buf),
1849 CEPH_OSD_CMPXATTR_OP_GT,
1850 CEPH_OSD_CMPXATTR_MODE_U64);
1851 if (err)
1852 goto out_put;
1853 }
1854
1855 {
1856 char xattr_buf[32];
1857 int xattr_len = snprintf(xattr_buf, sizeof(xattr_buf),
1858 "%llu", inline_version);
1859 err = osd_req_op_xattr_init(req, 2, CEPH_OSD_OP_SETXATTR,
1860 "inline_version",
1861 xattr_buf, xattr_len, 0, 0);
1862 if (err)
1863 goto out_put;
1864 }
1865
1866 req->r_mtime = inode->i_mtime;
1867 err = ceph_osdc_start_request(&fsc->client->osdc, req, false);
1868 if (!err)
1869 err = ceph_osdc_wait_request(&fsc->client->osdc, req);
1870
1871 ceph_update_write_latency(&fsc->mdsc->metric, req->r_start_latency,
1872 req->r_end_latency, err);
1873
1874out_put:
1875 ceph_osdc_put_request(req);
1876 if (err == -ECANCELED)
1877 err = 0;
1878out:
1879 if (page && page != locked_page) {
1880 if (from_pagecache) {
1881 unlock_page(page);
1882 put_page(page);
1883 } else
1884 __free_pages(page, 0);
1885 }
1886
1887 dout("uninline_data %p %llx.%llx inline_version %llu = %d\n",
1888 inode, ceph_vinop(inode), inline_version, err);
1889 return err;
1890}
1891
1892static const struct vm_operations_struct ceph_vmops = {
1893 .fault = ceph_filemap_fault,
1894 .page_mkwrite = ceph_page_mkwrite,
1895};
1896
1897int ceph_mmap(struct file *file, struct vm_area_struct *vma)
1898{
1899 struct address_space *mapping = file->f_mapping;
1900
1901 if (!mapping->a_ops->readpage)
1902 return -ENOEXEC;
1903 file_accessed(file);
1904 vma->vm_ops = &ceph_vmops;
1905 return 0;
1906}
1907
1908enum {
1909 POOL_READ = 1,
1910 POOL_WRITE = 2,
1911};
1912
1913static int __ceph_pool_perm_get(struct ceph_inode_info *ci,
1914 s64 pool, struct ceph_string *pool_ns)
1915{
1916 struct ceph_fs_client *fsc = ceph_inode_to_client(&ci->vfs_inode);
1917 struct ceph_mds_client *mdsc = fsc->mdsc;
1918 struct ceph_osd_request *rd_req = NULL, *wr_req = NULL;
1919 struct rb_node **p, *parent;
1920 struct ceph_pool_perm *perm;
1921 struct page **pages;
1922 size_t pool_ns_len;
1923 int err = 0, err2 = 0, have = 0;
1924
1925 down_read(&mdsc->pool_perm_rwsem);
1926 p = &mdsc->pool_perm_tree.rb_node;
1927 while (*p) {
1928 perm = rb_entry(*p, struct ceph_pool_perm, node);
1929 if (pool < perm->pool)
1930 p = &(*p)->rb_left;
1931 else if (pool > perm->pool)
1932 p = &(*p)->rb_right;
1933 else {
1934 int ret = ceph_compare_string(pool_ns,
1935 perm->pool_ns,
1936 perm->pool_ns_len);
1937 if (ret < 0)
1938 p = &(*p)->rb_left;
1939 else if (ret > 0)
1940 p = &(*p)->rb_right;
1941 else {
1942 have = perm->perm;
1943 break;
1944 }
1945 }
1946 }
1947 up_read(&mdsc->pool_perm_rwsem);
1948 if (*p)
1949 goto out;
1950
1951 if (pool_ns)
1952 dout("__ceph_pool_perm_get pool %lld ns %.*s no perm cached\n",
1953 pool, (int)pool_ns->len, pool_ns->str);
1954 else
1955 dout("__ceph_pool_perm_get pool %lld no perm cached\n", pool);
1956
1957 down_write(&mdsc->pool_perm_rwsem);
1958 p = &mdsc->pool_perm_tree.rb_node;
1959 parent = NULL;
1960 while (*p) {
1961 parent = *p;
1962 perm = rb_entry(parent, struct ceph_pool_perm, node);
1963 if (pool < perm->pool)
1964 p = &(*p)->rb_left;
1965 else if (pool > perm->pool)
1966 p = &(*p)->rb_right;
1967 else {
1968 int ret = ceph_compare_string(pool_ns,
1969 perm->pool_ns,
1970 perm->pool_ns_len);
1971 if (ret < 0)
1972 p = &(*p)->rb_left;
1973 else if (ret > 0)
1974 p = &(*p)->rb_right;
1975 else {
1976 have = perm->perm;
1977 break;
1978 }
1979 }
1980 }
1981 if (*p) {
1982 up_write(&mdsc->pool_perm_rwsem);
1983 goto out;
1984 }
1985
1986 rd_req = ceph_osdc_alloc_request(&fsc->client->osdc, NULL,
1987 1, false, GFP_NOFS);
1988 if (!rd_req) {
1989 err = -ENOMEM;
1990 goto out_unlock;
1991 }
1992
1993 rd_req->r_flags = CEPH_OSD_FLAG_READ;
1994 osd_req_op_init(rd_req, 0, CEPH_OSD_OP_STAT, 0);
1995 rd_req->r_base_oloc.pool = pool;
1996 if (pool_ns)
1997 rd_req->r_base_oloc.pool_ns = ceph_get_string(pool_ns);
1998 ceph_oid_printf(&rd_req->r_base_oid, "%llx.00000000", ci->i_vino.ino);
1999
2000 err = ceph_osdc_alloc_messages(rd_req, GFP_NOFS);
2001 if (err)
2002 goto out_unlock;
2003
2004 wr_req = ceph_osdc_alloc_request(&fsc->client->osdc, NULL,
2005 1, false, GFP_NOFS);
2006 if (!wr_req) {
2007 err = -ENOMEM;
2008 goto out_unlock;
2009 }
2010
2011 wr_req->r_flags = CEPH_OSD_FLAG_WRITE;
2012 osd_req_op_init(wr_req, 0, CEPH_OSD_OP_CREATE, CEPH_OSD_OP_FLAG_EXCL);
2013 ceph_oloc_copy(&wr_req->r_base_oloc, &rd_req->r_base_oloc);
2014 ceph_oid_copy(&wr_req->r_base_oid, &rd_req->r_base_oid);
2015
2016 err = ceph_osdc_alloc_messages(wr_req, GFP_NOFS);
2017 if (err)
2018 goto out_unlock;
2019
2020 /* one page should be large enough for STAT data */
2021 pages = ceph_alloc_page_vector(1, GFP_KERNEL);
2022 if (IS_ERR(pages)) {
2023 err = PTR_ERR(pages);
2024 goto out_unlock;
2025 }
2026
2027 osd_req_op_raw_data_in_pages(rd_req, 0, pages, PAGE_SIZE,
2028 0, false, true);
2029 err = ceph_osdc_start_request(&fsc->client->osdc, rd_req, false);
2030
2031 wr_req->r_mtime = ci->vfs_inode.i_mtime;
2032 err2 = ceph_osdc_start_request(&fsc->client->osdc, wr_req, false);
2033
2034 if (!err)
2035 err = ceph_osdc_wait_request(&fsc->client->osdc, rd_req);
2036 if (!err2)
2037 err2 = ceph_osdc_wait_request(&fsc->client->osdc, wr_req);
2038
2039 if (err >= 0 || err == -ENOENT)
2040 have |= POOL_READ;
2041 else if (err != -EPERM) {
2042 if (err == -EBLACKLISTED)
2043 fsc->blacklisted = true;
2044 goto out_unlock;
2045 }
2046
2047 if (err2 == 0 || err2 == -EEXIST)
2048 have |= POOL_WRITE;
2049 else if (err2 != -EPERM) {
2050 if (err2 == -EBLACKLISTED)
2051 fsc->blacklisted = true;
2052 err = err2;
2053 goto out_unlock;
2054 }
2055
2056 pool_ns_len = pool_ns ? pool_ns->len : 0;
2057 perm = kmalloc(sizeof(*perm) + pool_ns_len + 1, GFP_NOFS);
2058 if (!perm) {
2059 err = -ENOMEM;
2060 goto out_unlock;
2061 }
2062
2063 perm->pool = pool;
2064 perm->perm = have;
2065 perm->pool_ns_len = pool_ns_len;
2066 if (pool_ns_len > 0)
2067 memcpy(perm->pool_ns, pool_ns->str, pool_ns_len);
2068 perm->pool_ns[pool_ns_len] = 0;
2069
2070 rb_link_node(&perm->node, parent, p);
2071 rb_insert_color(&perm->node, &mdsc->pool_perm_tree);
2072 err = 0;
2073out_unlock:
2074 up_write(&mdsc->pool_perm_rwsem);
2075
2076 ceph_osdc_put_request(rd_req);
2077 ceph_osdc_put_request(wr_req);
2078out:
2079 if (!err)
2080 err = have;
2081 if (pool_ns)
2082 dout("__ceph_pool_perm_get pool %lld ns %.*s result = %d\n",
2083 pool, (int)pool_ns->len, pool_ns->str, err);
2084 else
2085 dout("__ceph_pool_perm_get pool %lld result = %d\n", pool, err);
2086 return err;
2087}
2088
2089int ceph_pool_perm_check(struct inode *inode, int need)
2090{
2091 struct ceph_inode_info *ci = ceph_inode(inode);
2092 struct ceph_string *pool_ns;
2093 s64 pool;
2094 int ret, flags;
2095
2096 if (ci->i_vino.snap != CEPH_NOSNAP) {
2097 /*
2098 * Pool permission check needs to write to the first object.
2099 * But for snapshot, head of the first object may have alread
2100 * been deleted. Skip check to avoid creating orphan object.
2101 */
2102 return 0;
2103 }
2104
2105 if (ceph_test_mount_opt(ceph_inode_to_client(inode),
2106 NOPOOLPERM))
2107 return 0;
2108
2109 spin_lock(&ci->i_ceph_lock);
2110 flags = ci->i_ceph_flags;
2111 pool = ci->i_layout.pool_id;
2112 spin_unlock(&ci->i_ceph_lock);
2113check:
2114 if (flags & CEPH_I_POOL_PERM) {
2115 if ((need & CEPH_CAP_FILE_RD) && !(flags & CEPH_I_POOL_RD)) {
2116 dout("ceph_pool_perm_check pool %lld no read perm\n",
2117 pool);
2118 return -EPERM;
2119 }
2120 if ((need & CEPH_CAP_FILE_WR) && !(flags & CEPH_I_POOL_WR)) {
2121 dout("ceph_pool_perm_check pool %lld no write perm\n",
2122 pool);
2123 return -EPERM;
2124 }
2125 return 0;
2126 }
2127
2128 pool_ns = ceph_try_get_string(ci->i_layout.pool_ns);
2129 ret = __ceph_pool_perm_get(ci, pool, pool_ns);
2130 ceph_put_string(pool_ns);
2131 if (ret < 0)
2132 return ret;
2133
2134 flags = CEPH_I_POOL_PERM;
2135 if (ret & POOL_READ)
2136 flags |= CEPH_I_POOL_RD;
2137 if (ret & POOL_WRITE)
2138 flags |= CEPH_I_POOL_WR;
2139
2140 spin_lock(&ci->i_ceph_lock);
2141 if (pool == ci->i_layout.pool_id &&
2142 pool_ns == rcu_dereference_raw(ci->i_layout.pool_ns)) {
2143 ci->i_ceph_flags |= flags;
2144 } else {
2145 pool = ci->i_layout.pool_id;
2146 flags = ci->i_ceph_flags;
2147 }
2148 spin_unlock(&ci->i_ceph_lock);
2149 goto check;
2150}
2151
2152void ceph_pool_perm_destroy(struct ceph_mds_client *mdsc)
2153{
2154 struct ceph_pool_perm *perm;
2155 struct rb_node *n;
2156
2157 while (!RB_EMPTY_ROOT(&mdsc->pool_perm_tree)) {
2158 n = rb_first(&mdsc->pool_perm_tree);
2159 perm = rb_entry(n, struct ceph_pool_perm, node);
2160 rb_erase(n, &mdsc->pool_perm_tree);
2161 kfree(perm);
2162 }
2163}
1#include <linux/ceph/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 "mds_client.h"
14#include <linux/ceph/osd_client.h>
15
16/*
17 * Ceph address space ops.
18 *
19 * There are a few funny things going on here.
20 *
21 * The page->private field is used to reference a struct
22 * ceph_snap_context for _every_ dirty page. This indicates which
23 * snapshot the page was logically dirtied in, and thus which snap
24 * context needs to be associated with the osd write during writeback.
25 *
26 * Similarly, struct ceph_inode_info maintains a set of counters to
27 * count dirty pages on the inode. In the absence of snapshots,
28 * i_wrbuffer_ref == i_wrbuffer_ref_head == the dirty page count.
29 *
30 * When a snapshot is taken (that is, when the client receives
31 * notification that a snapshot was taken), each inode with caps and
32 * with dirty pages (dirty pages implies there is a cap) gets a new
33 * ceph_cap_snap in the i_cap_snaps list (which is sorted in ascending
34 * order, new snaps go to the tail). The i_wrbuffer_ref_head count is
35 * moved to capsnap->dirty. (Unless a sync write is currently in
36 * progress. In that case, the capsnap is said to be "pending", new
37 * writes cannot start, and the capsnap isn't "finalized" until the
38 * write completes (or fails) and a final size/mtime for the inode for
39 * that snap can be settled upon.) i_wrbuffer_ref_head is reset to 0.
40 *
41 * On writeback, we must submit writes to the osd IN SNAP ORDER. So,
42 * we look for the first capsnap in i_cap_snaps and write out pages in
43 * that snap context _only_. Then we move on to the next capsnap,
44 * eventually reaching the "live" or "head" context (i.e., pages that
45 * are not yet snapped) and are writing the most recently dirtied
46 * pages.
47 *
48 * Invalidate and so forth must take care to ensure the dirty page
49 * accounting is preserved.
50 */
51
52#define CONGESTION_ON_THRESH(congestion_kb) (congestion_kb >> (PAGE_SHIFT-10))
53#define CONGESTION_OFF_THRESH(congestion_kb) \
54 (CONGESTION_ON_THRESH(congestion_kb) - \
55 (CONGESTION_ON_THRESH(congestion_kb) >> 2))
56
57
58
59/*
60 * Dirty a page. Optimistically adjust accounting, on the assumption
61 * that we won't race with invalidate. If we do, readjust.
62 */
63static int ceph_set_page_dirty(struct page *page)
64{
65 struct address_space *mapping = page->mapping;
66 struct inode *inode;
67 struct ceph_inode_info *ci;
68 int undo = 0;
69 struct ceph_snap_context *snapc;
70
71 if (unlikely(!mapping))
72 return !TestSetPageDirty(page);
73
74 if (TestSetPageDirty(page)) {
75 dout("%p set_page_dirty %p idx %lu -- already dirty\n",
76 mapping->host, page, page->index);
77 return 0;
78 }
79
80 inode = mapping->host;
81 ci = ceph_inode(inode);
82
83 /*
84 * Note that we're grabbing a snapc ref here without holding
85 * any locks!
86 */
87 snapc = ceph_get_snap_context(ci->i_snap_realm->cached_context);
88
89 /* dirty the head */
90 spin_lock(&inode->i_lock);
91 if (ci->i_head_snapc == NULL)
92 ci->i_head_snapc = ceph_get_snap_context(snapc);
93 ++ci->i_wrbuffer_ref_head;
94 if (ci->i_wrbuffer_ref == 0)
95 ihold(inode);
96 ++ci->i_wrbuffer_ref;
97 dout("%p set_page_dirty %p idx %lu head %d/%d -> %d/%d "
98 "snapc %p seq %lld (%d snaps)\n",
99 mapping->host, page, page->index,
100 ci->i_wrbuffer_ref-1, ci->i_wrbuffer_ref_head-1,
101 ci->i_wrbuffer_ref, ci->i_wrbuffer_ref_head,
102 snapc, snapc->seq, snapc->num_snaps);
103 spin_unlock(&inode->i_lock);
104
105 /* now adjust page */
106 spin_lock_irq(&mapping->tree_lock);
107 if (page->mapping) { /* Race with truncate? */
108 WARN_ON_ONCE(!PageUptodate(page));
109 account_page_dirtied(page, page->mapping);
110 radix_tree_tag_set(&mapping->page_tree,
111 page_index(page), PAGECACHE_TAG_DIRTY);
112
113 /*
114 * Reference snap context in page->private. Also set
115 * PagePrivate so that we get invalidatepage callback.
116 */
117 page->private = (unsigned long)snapc;
118 SetPagePrivate(page);
119 } else {
120 dout("ANON set_page_dirty %p (raced truncate?)\n", page);
121 undo = 1;
122 }
123
124 spin_unlock_irq(&mapping->tree_lock);
125
126 if (undo)
127 /* whoops, we failed to dirty the page */
128 ceph_put_wrbuffer_cap_refs(ci, 1, snapc);
129
130 __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
131
132 BUG_ON(!PageDirty(page));
133 return 1;
134}
135
136/*
137 * If we are truncating the full page (i.e. offset == 0), adjust the
138 * dirty page counters appropriately. Only called if there is private
139 * data on the page.
140 */
141static void ceph_invalidatepage(struct page *page, unsigned long offset)
142{
143 struct inode *inode;
144 struct ceph_inode_info *ci;
145 struct ceph_snap_context *snapc = (void *)page->private;
146
147 BUG_ON(!PageLocked(page));
148 BUG_ON(!page->private);
149 BUG_ON(!PagePrivate(page));
150 BUG_ON(!page->mapping);
151
152 inode = page->mapping->host;
153
154 /*
155 * We can get non-dirty pages here due to races between
156 * set_page_dirty and truncate_complete_page; just spit out a
157 * warning, in case we end up with accounting problems later.
158 */
159 if (!PageDirty(page))
160 pr_err("%p invalidatepage %p page not dirty\n", inode, page);
161
162 if (offset == 0)
163 ClearPageChecked(page);
164
165 ci = ceph_inode(inode);
166 if (offset == 0) {
167 dout("%p invalidatepage %p idx %lu full dirty page %lu\n",
168 inode, page, page->index, offset);
169 ceph_put_wrbuffer_cap_refs(ci, 1, snapc);
170 ceph_put_snap_context(snapc);
171 page->private = 0;
172 ClearPagePrivate(page);
173 } else {
174 dout("%p invalidatepage %p idx %lu partial dirty page\n",
175 inode, page, page->index);
176 }
177}
178
179/* just a sanity check */
180static int ceph_releasepage(struct page *page, gfp_t g)
181{
182 struct inode *inode = page->mapping ? page->mapping->host : NULL;
183 dout("%p releasepage %p idx %lu\n", inode, page, page->index);
184 WARN_ON(PageDirty(page));
185 WARN_ON(page->private);
186 WARN_ON(PagePrivate(page));
187 return 0;
188}
189
190/*
191 * read a single page, without unlocking it.
192 */
193static int readpage_nounlock(struct file *filp, struct page *page)
194{
195 struct inode *inode = filp->f_dentry->d_inode;
196 struct ceph_inode_info *ci = ceph_inode(inode);
197 struct ceph_osd_client *osdc =
198 &ceph_inode_to_client(inode)->client->osdc;
199 int err = 0;
200 u64 len = PAGE_CACHE_SIZE;
201
202 dout("readpage inode %p file %p page %p index %lu\n",
203 inode, filp, page, page->index);
204 err = ceph_osdc_readpages(osdc, ceph_vino(inode), &ci->i_layout,
205 page->index << PAGE_CACHE_SHIFT, &len,
206 ci->i_truncate_seq, ci->i_truncate_size,
207 &page, 1, 0);
208 if (err == -ENOENT)
209 err = 0;
210 if (err < 0) {
211 SetPageError(page);
212 goto out;
213 } else if (err < PAGE_CACHE_SIZE) {
214 /* zero fill remainder of page */
215 zero_user_segment(page, err, PAGE_CACHE_SIZE);
216 }
217 SetPageUptodate(page);
218
219out:
220 return err < 0 ? err : 0;
221}
222
223static int ceph_readpage(struct file *filp, struct page *page)
224{
225 int r = readpage_nounlock(filp, page);
226 unlock_page(page);
227 return r;
228}
229
230/*
231 * Build a vector of contiguous pages from the provided page list.
232 */
233static struct page **page_vector_from_list(struct list_head *page_list,
234 unsigned *nr_pages)
235{
236 struct page **pages;
237 struct page *page;
238 int next_index, contig_pages = 0;
239
240 /* build page vector */
241 pages = kmalloc(sizeof(*pages) * *nr_pages, GFP_NOFS);
242 if (!pages)
243 return ERR_PTR(-ENOMEM);
244
245 BUG_ON(list_empty(page_list));
246 next_index = list_entry(page_list->prev, struct page, lru)->index;
247 list_for_each_entry_reverse(page, page_list, lru) {
248 if (page->index == next_index) {
249 dout("readpages page %d %p\n", contig_pages, page);
250 pages[contig_pages] = page;
251 contig_pages++;
252 next_index++;
253 } else {
254 break;
255 }
256 }
257 *nr_pages = contig_pages;
258 return pages;
259}
260
261/*
262 * Read multiple pages. Leave pages we don't read + unlock in page_list;
263 * the caller (VM) cleans them up.
264 */
265static int ceph_readpages(struct file *file, struct address_space *mapping,
266 struct list_head *page_list, unsigned nr_pages)
267{
268 struct inode *inode = file->f_dentry->d_inode;
269 struct ceph_inode_info *ci = ceph_inode(inode);
270 struct ceph_osd_client *osdc =
271 &ceph_inode_to_client(inode)->client->osdc;
272 int rc = 0;
273 struct page **pages;
274 loff_t offset;
275 u64 len;
276
277 dout("readpages %p file %p nr_pages %d\n",
278 inode, file, nr_pages);
279
280 pages = page_vector_from_list(page_list, &nr_pages);
281 if (IS_ERR(pages))
282 return PTR_ERR(pages);
283
284 /* guess read extent */
285 offset = pages[0]->index << PAGE_CACHE_SHIFT;
286 len = nr_pages << PAGE_CACHE_SHIFT;
287 rc = ceph_osdc_readpages(osdc, ceph_vino(inode), &ci->i_layout,
288 offset, &len,
289 ci->i_truncate_seq, ci->i_truncate_size,
290 pages, nr_pages, 0);
291 if (rc == -ENOENT)
292 rc = 0;
293 if (rc < 0)
294 goto out;
295
296 for (; !list_empty(page_list) && len > 0;
297 rc -= PAGE_CACHE_SIZE, len -= PAGE_CACHE_SIZE) {
298 struct page *page =
299 list_entry(page_list->prev, struct page, lru);
300
301 list_del(&page->lru);
302
303 if (rc < (int)PAGE_CACHE_SIZE) {
304 /* zero (remainder of) page */
305 int s = rc < 0 ? 0 : rc;
306 zero_user_segment(page, s, PAGE_CACHE_SIZE);
307 }
308
309 if (add_to_page_cache_lru(page, mapping, page->index,
310 GFP_NOFS)) {
311 page_cache_release(page);
312 dout("readpages %p add_to_page_cache failed %p\n",
313 inode, page);
314 continue;
315 }
316 dout("readpages %p adding %p idx %lu\n", inode, page,
317 page->index);
318 flush_dcache_page(page);
319 SetPageUptodate(page);
320 unlock_page(page);
321 page_cache_release(page);
322 }
323 rc = 0;
324
325out:
326 kfree(pages);
327 return rc;
328}
329
330/*
331 * Get ref for the oldest snapc for an inode with dirty data... that is, the
332 * only snap context we are allowed to write back.
333 */
334static struct ceph_snap_context *get_oldest_context(struct inode *inode,
335 u64 *snap_size)
336{
337 struct ceph_inode_info *ci = ceph_inode(inode);
338 struct ceph_snap_context *snapc = NULL;
339 struct ceph_cap_snap *capsnap = NULL;
340
341 spin_lock(&inode->i_lock);
342 list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) {
343 dout(" cap_snap %p snapc %p has %d dirty pages\n", capsnap,
344 capsnap->context, capsnap->dirty_pages);
345 if (capsnap->dirty_pages) {
346 snapc = ceph_get_snap_context(capsnap->context);
347 if (snap_size)
348 *snap_size = capsnap->size;
349 break;
350 }
351 }
352 if (!snapc && ci->i_wrbuffer_ref_head) {
353 snapc = ceph_get_snap_context(ci->i_head_snapc);
354 dout(" head snapc %p has %d dirty pages\n",
355 snapc, ci->i_wrbuffer_ref_head);
356 }
357 spin_unlock(&inode->i_lock);
358 return snapc;
359}
360
361/*
362 * Write a single page, but leave the page locked.
363 *
364 * If we get a write error, set the page error bit, but still adjust the
365 * dirty page accounting (i.e., page is no longer dirty).
366 */
367static int writepage_nounlock(struct page *page, struct writeback_control *wbc)
368{
369 struct inode *inode;
370 struct ceph_inode_info *ci;
371 struct ceph_fs_client *fsc;
372 struct ceph_osd_client *osdc;
373 loff_t page_off = page->index << PAGE_CACHE_SHIFT;
374 int len = PAGE_CACHE_SIZE;
375 loff_t i_size;
376 int err = 0;
377 struct ceph_snap_context *snapc, *oldest;
378 u64 snap_size = 0;
379 long writeback_stat;
380
381 dout("writepage %p idx %lu\n", page, page->index);
382
383 if (!page->mapping || !page->mapping->host) {
384 dout("writepage %p - no mapping\n", page);
385 return -EFAULT;
386 }
387 inode = page->mapping->host;
388 ci = ceph_inode(inode);
389 fsc = ceph_inode_to_client(inode);
390 osdc = &fsc->client->osdc;
391
392 /* verify this is a writeable snap context */
393 snapc = (void *)page->private;
394 if (snapc == NULL) {
395 dout("writepage %p page %p not dirty?\n", inode, page);
396 goto out;
397 }
398 oldest = get_oldest_context(inode, &snap_size);
399 if (snapc->seq > oldest->seq) {
400 dout("writepage %p page %p snapc %p not writeable - noop\n",
401 inode, page, (void *)page->private);
402 /* we should only noop if called by kswapd */
403 WARN_ON((current->flags & PF_MEMALLOC) == 0);
404 ceph_put_snap_context(oldest);
405 goto out;
406 }
407 ceph_put_snap_context(oldest);
408
409 /* is this a partial page at end of file? */
410 if (snap_size)
411 i_size = snap_size;
412 else
413 i_size = i_size_read(inode);
414 if (i_size < page_off + len)
415 len = i_size - page_off;
416
417 dout("writepage %p page %p index %lu on %llu~%u snapc %p\n",
418 inode, page, page->index, page_off, len, snapc);
419
420 writeback_stat = atomic_long_inc_return(&fsc->writeback_count);
421 if (writeback_stat >
422 CONGESTION_ON_THRESH(fsc->mount_options->congestion_kb))
423 set_bdi_congested(&fsc->backing_dev_info, BLK_RW_ASYNC);
424
425 set_page_writeback(page);
426 err = ceph_osdc_writepages(osdc, ceph_vino(inode),
427 &ci->i_layout, snapc,
428 page_off, len,
429 ci->i_truncate_seq, ci->i_truncate_size,
430 &inode->i_mtime,
431 &page, 1, 0, 0, true);
432 if (err < 0) {
433 dout("writepage setting page/mapping error %d %p\n", err, page);
434 SetPageError(page);
435 mapping_set_error(&inode->i_data, err);
436 if (wbc)
437 wbc->pages_skipped++;
438 } else {
439 dout("writepage cleaned page %p\n", page);
440 err = 0; /* vfs expects us to return 0 */
441 }
442 page->private = 0;
443 ClearPagePrivate(page);
444 end_page_writeback(page);
445 ceph_put_wrbuffer_cap_refs(ci, 1, snapc);
446 ceph_put_snap_context(snapc); /* page's reference */
447out:
448 return err;
449}
450
451static int ceph_writepage(struct page *page, struct writeback_control *wbc)
452{
453 int err;
454 struct inode *inode = page->mapping->host;
455 BUG_ON(!inode);
456 ihold(inode);
457 err = writepage_nounlock(page, wbc);
458 unlock_page(page);
459 iput(inode);
460 return err;
461}
462
463
464/*
465 * lame release_pages helper. release_pages() isn't exported to
466 * modules.
467 */
468static void ceph_release_pages(struct page **pages, int num)
469{
470 struct pagevec pvec;
471 int i;
472
473 pagevec_init(&pvec, 0);
474 for (i = 0; i < num; i++) {
475 if (pagevec_add(&pvec, pages[i]) == 0)
476 pagevec_release(&pvec);
477 }
478 pagevec_release(&pvec);
479}
480
481
482/*
483 * async writeback completion handler.
484 *
485 * If we get an error, set the mapping error bit, but not the individual
486 * page error bits.
487 */
488static void writepages_finish(struct ceph_osd_request *req,
489 struct ceph_msg *msg)
490{
491 struct inode *inode = req->r_inode;
492 struct ceph_osd_reply_head *replyhead;
493 struct ceph_osd_op *op;
494 struct ceph_inode_info *ci = ceph_inode(inode);
495 unsigned wrote;
496 struct page *page;
497 int i;
498 struct ceph_snap_context *snapc = req->r_snapc;
499 struct address_space *mapping = inode->i_mapping;
500 __s32 rc = -EIO;
501 u64 bytes = 0;
502 struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
503 long writeback_stat;
504 unsigned issued = ceph_caps_issued(ci);
505
506 /* parse reply */
507 replyhead = msg->front.iov_base;
508 WARN_ON(le32_to_cpu(replyhead->num_ops) == 0);
509 op = (void *)(replyhead + 1);
510 rc = le32_to_cpu(replyhead->result);
511 bytes = le64_to_cpu(op->extent.length);
512
513 if (rc >= 0) {
514 /*
515 * Assume we wrote the pages we originally sent. The
516 * osd might reply with fewer pages if our writeback
517 * raced with a truncation and was adjusted at the osd,
518 * so don't believe the reply.
519 */
520 wrote = req->r_num_pages;
521 } else {
522 wrote = 0;
523 mapping_set_error(mapping, rc);
524 }
525 dout("writepages_finish %p rc %d bytes %llu wrote %d (pages)\n",
526 inode, rc, bytes, wrote);
527
528 /* clean all pages */
529 for (i = 0; i < req->r_num_pages; i++) {
530 page = req->r_pages[i];
531 BUG_ON(!page);
532 WARN_ON(!PageUptodate(page));
533
534 writeback_stat =
535 atomic_long_dec_return(&fsc->writeback_count);
536 if (writeback_stat <
537 CONGESTION_OFF_THRESH(fsc->mount_options->congestion_kb))
538 clear_bdi_congested(&fsc->backing_dev_info,
539 BLK_RW_ASYNC);
540
541 ceph_put_snap_context((void *)page->private);
542 page->private = 0;
543 ClearPagePrivate(page);
544 dout("unlocking %d %p\n", i, page);
545 end_page_writeback(page);
546
547 /*
548 * We lost the cache cap, need to truncate the page before
549 * it is unlocked, otherwise we'd truncate it later in the
550 * page truncation thread, possibly losing some data that
551 * raced its way in
552 */
553 if ((issued & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) == 0)
554 generic_error_remove_page(inode->i_mapping, page);
555
556 unlock_page(page);
557 }
558 dout("%p wrote+cleaned %d pages\n", inode, wrote);
559 ceph_put_wrbuffer_cap_refs(ci, req->r_num_pages, snapc);
560
561 ceph_release_pages(req->r_pages, req->r_num_pages);
562 if (req->r_pages_from_pool)
563 mempool_free(req->r_pages,
564 ceph_sb_to_client(inode->i_sb)->wb_pagevec_pool);
565 else
566 kfree(req->r_pages);
567 ceph_osdc_put_request(req);
568}
569
570/*
571 * allocate a page vec, either directly, or if necessary, via a the
572 * mempool. we avoid the mempool if we can because req->r_num_pages
573 * may be less than the maximum write size.
574 */
575static void alloc_page_vec(struct ceph_fs_client *fsc,
576 struct ceph_osd_request *req)
577{
578 req->r_pages = kmalloc(sizeof(struct page *) * req->r_num_pages,
579 GFP_NOFS);
580 if (!req->r_pages) {
581 req->r_pages = mempool_alloc(fsc->wb_pagevec_pool, GFP_NOFS);
582 req->r_pages_from_pool = 1;
583 WARN_ON(!req->r_pages);
584 }
585}
586
587/*
588 * initiate async writeback
589 */
590static int ceph_writepages_start(struct address_space *mapping,
591 struct writeback_control *wbc)
592{
593 struct inode *inode = mapping->host;
594 struct ceph_inode_info *ci = ceph_inode(inode);
595 struct ceph_fs_client *fsc;
596 pgoff_t index, start, end;
597 int range_whole = 0;
598 int should_loop = 1;
599 pgoff_t max_pages = 0, max_pages_ever = 0;
600 struct ceph_snap_context *snapc = NULL, *last_snapc = NULL, *pgsnapc;
601 struct pagevec pvec;
602 int done = 0;
603 int rc = 0;
604 unsigned wsize = 1 << inode->i_blkbits;
605 struct ceph_osd_request *req = NULL;
606 int do_sync;
607 u64 snap_size = 0;
608
609 /*
610 * Include a 'sync' in the OSD request if this is a data
611 * integrity write (e.g., O_SYNC write or fsync()), or if our
612 * cap is being revoked.
613 */
614 do_sync = wbc->sync_mode == WB_SYNC_ALL;
615 if (ceph_caps_revoking(ci, CEPH_CAP_FILE_BUFFER))
616 do_sync = 1;
617 dout("writepages_start %p dosync=%d (mode=%s)\n",
618 inode, do_sync,
619 wbc->sync_mode == WB_SYNC_NONE ? "NONE" :
620 (wbc->sync_mode == WB_SYNC_ALL ? "ALL" : "HOLD"));
621
622 fsc = ceph_inode_to_client(inode);
623 if (fsc->mount_state == CEPH_MOUNT_SHUTDOWN) {
624 pr_warning("writepage_start %p on forced umount\n", inode);
625 return -EIO; /* we're in a forced umount, don't write! */
626 }
627 if (fsc->mount_options->wsize && fsc->mount_options->wsize < wsize)
628 wsize = fsc->mount_options->wsize;
629 if (wsize < PAGE_CACHE_SIZE)
630 wsize = PAGE_CACHE_SIZE;
631 max_pages_ever = wsize >> PAGE_CACHE_SHIFT;
632
633 pagevec_init(&pvec, 0);
634
635 /* where to start/end? */
636 if (wbc->range_cyclic) {
637 start = mapping->writeback_index; /* Start from prev offset */
638 end = -1;
639 dout(" cyclic, start at %lu\n", start);
640 } else {
641 start = wbc->range_start >> PAGE_CACHE_SHIFT;
642 end = wbc->range_end >> PAGE_CACHE_SHIFT;
643 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
644 range_whole = 1;
645 should_loop = 0;
646 dout(" not cyclic, %lu to %lu\n", start, end);
647 }
648 index = start;
649
650retry:
651 /* find oldest snap context with dirty data */
652 ceph_put_snap_context(snapc);
653 snapc = get_oldest_context(inode, &snap_size);
654 if (!snapc) {
655 /* hmm, why does writepages get called when there
656 is no dirty data? */
657 dout(" no snap context with dirty data?\n");
658 goto out;
659 }
660 dout(" oldest snapc is %p seq %lld (%d snaps)\n",
661 snapc, snapc->seq, snapc->num_snaps);
662 if (last_snapc && snapc != last_snapc) {
663 /* if we switched to a newer snapc, restart our scan at the
664 * start of the original file range. */
665 dout(" snapc differs from last pass, restarting at %lu\n",
666 index);
667 index = start;
668 }
669 last_snapc = snapc;
670
671 while (!done && index <= end) {
672 unsigned i;
673 int first;
674 pgoff_t next;
675 int pvec_pages, locked_pages;
676 struct page *page;
677 int want;
678 u64 offset, len;
679 struct ceph_osd_request_head *reqhead;
680 struct ceph_osd_op *op;
681 long writeback_stat;
682
683 next = 0;
684 locked_pages = 0;
685 max_pages = max_pages_ever;
686
687get_more_pages:
688 first = -1;
689 want = min(end - index,
690 min((pgoff_t)PAGEVEC_SIZE,
691 max_pages - (pgoff_t)locked_pages) - 1)
692 + 1;
693 pvec_pages = pagevec_lookup_tag(&pvec, mapping, &index,
694 PAGECACHE_TAG_DIRTY,
695 want);
696 dout("pagevec_lookup_tag got %d\n", pvec_pages);
697 if (!pvec_pages && !locked_pages)
698 break;
699 for (i = 0; i < pvec_pages && locked_pages < max_pages; i++) {
700 page = pvec.pages[i];
701 dout("? %p idx %lu\n", page, page->index);
702 if (locked_pages == 0)
703 lock_page(page); /* first page */
704 else if (!trylock_page(page))
705 break;
706
707 /* only dirty pages, or our accounting breaks */
708 if (unlikely(!PageDirty(page)) ||
709 unlikely(page->mapping != mapping)) {
710 dout("!dirty or !mapping %p\n", page);
711 unlock_page(page);
712 break;
713 }
714 if (!wbc->range_cyclic && page->index > end) {
715 dout("end of range %p\n", page);
716 done = 1;
717 unlock_page(page);
718 break;
719 }
720 if (next && (page->index != next)) {
721 dout("not consecutive %p\n", page);
722 unlock_page(page);
723 break;
724 }
725 if (wbc->sync_mode != WB_SYNC_NONE) {
726 dout("waiting on writeback %p\n", page);
727 wait_on_page_writeback(page);
728 }
729 if ((snap_size && page_offset(page) > snap_size) ||
730 (!snap_size &&
731 page_offset(page) > i_size_read(inode))) {
732 dout("%p page eof %llu\n", page, snap_size ?
733 snap_size : i_size_read(inode));
734 done = 1;
735 unlock_page(page);
736 break;
737 }
738 if (PageWriteback(page)) {
739 dout("%p under writeback\n", page);
740 unlock_page(page);
741 break;
742 }
743
744 /* only if matching snap context */
745 pgsnapc = (void *)page->private;
746 if (pgsnapc->seq > snapc->seq) {
747 dout("page snapc %p %lld > oldest %p %lld\n",
748 pgsnapc, pgsnapc->seq, snapc, snapc->seq);
749 unlock_page(page);
750 if (!locked_pages)
751 continue; /* keep looking for snap */
752 break;
753 }
754
755 if (!clear_page_dirty_for_io(page)) {
756 dout("%p !clear_page_dirty_for_io\n", page);
757 unlock_page(page);
758 break;
759 }
760
761 /* ok */
762 if (locked_pages == 0) {
763 /* prepare async write request */
764 offset = (unsigned long long)page->index
765 << PAGE_CACHE_SHIFT;
766 len = wsize;
767 req = ceph_osdc_new_request(&fsc->client->osdc,
768 &ci->i_layout,
769 ceph_vino(inode),
770 offset, &len,
771 CEPH_OSD_OP_WRITE,
772 CEPH_OSD_FLAG_WRITE |
773 CEPH_OSD_FLAG_ONDISK,
774 snapc, do_sync,
775 ci->i_truncate_seq,
776 ci->i_truncate_size,
777 &inode->i_mtime, true, 1, 0);
778
779 if (!req) {
780 rc = -ENOMEM;
781 unlock_page(page);
782 break;
783 }
784
785 max_pages = req->r_num_pages;
786
787 alloc_page_vec(fsc, req);
788 req->r_callback = writepages_finish;
789 req->r_inode = inode;
790 }
791
792 /* note position of first page in pvec */
793 if (first < 0)
794 first = i;
795 dout("%p will write page %p idx %lu\n",
796 inode, page, page->index);
797
798 writeback_stat =
799 atomic_long_inc_return(&fsc->writeback_count);
800 if (writeback_stat > CONGESTION_ON_THRESH(
801 fsc->mount_options->congestion_kb)) {
802 set_bdi_congested(&fsc->backing_dev_info,
803 BLK_RW_ASYNC);
804 }
805
806 set_page_writeback(page);
807 req->r_pages[locked_pages] = page;
808 locked_pages++;
809 next = page->index + 1;
810 }
811
812 /* did we get anything? */
813 if (!locked_pages)
814 goto release_pvec_pages;
815 if (i) {
816 int j;
817 BUG_ON(!locked_pages || first < 0);
818
819 if (pvec_pages && i == pvec_pages &&
820 locked_pages < max_pages) {
821 dout("reached end pvec, trying for more\n");
822 pagevec_reinit(&pvec);
823 goto get_more_pages;
824 }
825
826 /* shift unused pages over in the pvec... we
827 * will need to release them below. */
828 for (j = i; j < pvec_pages; j++) {
829 dout(" pvec leftover page %p\n",
830 pvec.pages[j]);
831 pvec.pages[j-i+first] = pvec.pages[j];
832 }
833 pvec.nr -= i-first;
834 }
835
836 /* submit the write */
837 offset = req->r_pages[0]->index << PAGE_CACHE_SHIFT;
838 len = min((snap_size ? snap_size : i_size_read(inode)) - offset,
839 (u64)locked_pages << PAGE_CACHE_SHIFT);
840 dout("writepages got %d pages at %llu~%llu\n",
841 locked_pages, offset, len);
842
843 /* revise final length, page count */
844 req->r_num_pages = locked_pages;
845 reqhead = req->r_request->front.iov_base;
846 op = (void *)(reqhead + 1);
847 op->extent.length = cpu_to_le64(len);
848 op->payload_len = cpu_to_le32(len);
849 req->r_request->hdr.data_len = cpu_to_le32(len);
850
851 rc = ceph_osdc_start_request(&fsc->client->osdc, req, true);
852 BUG_ON(rc);
853 req = NULL;
854
855 /* continue? */
856 index = next;
857 wbc->nr_to_write -= locked_pages;
858 if (wbc->nr_to_write <= 0)
859 done = 1;
860
861release_pvec_pages:
862 dout("pagevec_release on %d pages (%p)\n", (int)pvec.nr,
863 pvec.nr ? pvec.pages[0] : NULL);
864 pagevec_release(&pvec);
865
866 if (locked_pages && !done)
867 goto retry;
868 }
869
870 if (should_loop && !done) {
871 /* more to do; loop back to beginning of file */
872 dout("writepages looping back to beginning of file\n");
873 should_loop = 0;
874 index = 0;
875 goto retry;
876 }
877
878 if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
879 mapping->writeback_index = index;
880
881out:
882 if (req)
883 ceph_osdc_put_request(req);
884 ceph_put_snap_context(snapc);
885 dout("writepages done, rc = %d\n", rc);
886 return rc;
887}
888
889
890
891/*
892 * See if a given @snapc is either writeable, or already written.
893 */
894static int context_is_writeable_or_written(struct inode *inode,
895 struct ceph_snap_context *snapc)
896{
897 struct ceph_snap_context *oldest = get_oldest_context(inode, NULL);
898 int ret = !oldest || snapc->seq <= oldest->seq;
899
900 ceph_put_snap_context(oldest);
901 return ret;
902}
903
904/*
905 * We are only allowed to write into/dirty the page if the page is
906 * clean, or already dirty within the same snap context.
907 *
908 * called with page locked.
909 * return success with page locked,
910 * or any failure (incl -EAGAIN) with page unlocked.
911 */
912static int ceph_update_writeable_page(struct file *file,
913 loff_t pos, unsigned len,
914 struct page *page)
915{
916 struct inode *inode = file->f_dentry->d_inode;
917 struct ceph_inode_info *ci = ceph_inode(inode);
918 struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc;
919 loff_t page_off = pos & PAGE_CACHE_MASK;
920 int pos_in_page = pos & ~PAGE_CACHE_MASK;
921 int end_in_page = pos_in_page + len;
922 loff_t i_size;
923 int r;
924 struct ceph_snap_context *snapc, *oldest;
925
926retry_locked:
927 /* writepages currently holds page lock, but if we change that later, */
928 wait_on_page_writeback(page);
929
930 /* check snap context */
931 BUG_ON(!ci->i_snap_realm);
932 down_read(&mdsc->snap_rwsem);
933 BUG_ON(!ci->i_snap_realm->cached_context);
934 snapc = (void *)page->private;
935 if (snapc && snapc != ci->i_head_snapc) {
936 /*
937 * this page is already dirty in another (older) snap
938 * context! is it writeable now?
939 */
940 oldest = get_oldest_context(inode, NULL);
941 up_read(&mdsc->snap_rwsem);
942
943 if (snapc->seq > oldest->seq) {
944 ceph_put_snap_context(oldest);
945 dout(" page %p snapc %p not current or oldest\n",
946 page, snapc);
947 /*
948 * queue for writeback, and wait for snapc to
949 * be writeable or written
950 */
951 snapc = ceph_get_snap_context(snapc);
952 unlock_page(page);
953 ceph_queue_writeback(inode);
954 r = wait_event_interruptible(ci->i_cap_wq,
955 context_is_writeable_or_written(inode, snapc));
956 ceph_put_snap_context(snapc);
957 if (r == -ERESTARTSYS)
958 return r;
959 return -EAGAIN;
960 }
961 ceph_put_snap_context(oldest);
962
963 /* yay, writeable, do it now (without dropping page lock) */
964 dout(" page %p snapc %p not current, but oldest\n",
965 page, snapc);
966 if (!clear_page_dirty_for_io(page))
967 goto retry_locked;
968 r = writepage_nounlock(page, NULL);
969 if (r < 0)
970 goto fail_nosnap;
971 goto retry_locked;
972 }
973
974 if (PageUptodate(page)) {
975 dout(" page %p already uptodate\n", page);
976 return 0;
977 }
978
979 /* full page? */
980 if (pos_in_page == 0 && len == PAGE_CACHE_SIZE)
981 return 0;
982
983 /* past end of file? */
984 i_size = inode->i_size; /* caller holds i_mutex */
985
986 if (i_size + len > inode->i_sb->s_maxbytes) {
987 /* file is too big */
988 r = -EINVAL;
989 goto fail;
990 }
991
992 if (page_off >= i_size ||
993 (pos_in_page == 0 && (pos+len) >= i_size &&
994 end_in_page - pos_in_page != PAGE_CACHE_SIZE)) {
995 dout(" zeroing %p 0 - %d and %d - %d\n",
996 page, pos_in_page, end_in_page, (int)PAGE_CACHE_SIZE);
997 zero_user_segments(page,
998 0, pos_in_page,
999 end_in_page, PAGE_CACHE_SIZE);
1000 return 0;
1001 }
1002
1003 /* we need to read it. */
1004 up_read(&mdsc->snap_rwsem);
1005 r = readpage_nounlock(file, page);
1006 if (r < 0)
1007 goto fail_nosnap;
1008 goto retry_locked;
1009
1010fail:
1011 up_read(&mdsc->snap_rwsem);
1012fail_nosnap:
1013 unlock_page(page);
1014 return r;
1015}
1016
1017/*
1018 * We are only allowed to write into/dirty the page if the page is
1019 * clean, or already dirty within the same snap context.
1020 */
1021static int ceph_write_begin(struct file *file, struct address_space *mapping,
1022 loff_t pos, unsigned len, unsigned flags,
1023 struct page **pagep, void **fsdata)
1024{
1025 struct inode *inode = file->f_dentry->d_inode;
1026 struct page *page;
1027 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
1028 int r;
1029
1030 do {
1031 /* get a page */
1032 page = grab_cache_page_write_begin(mapping, index, 0);
1033 if (!page)
1034 return -ENOMEM;
1035 *pagep = page;
1036
1037 dout("write_begin file %p inode %p page %p %d~%d\n", file,
1038 inode, page, (int)pos, (int)len);
1039
1040 r = ceph_update_writeable_page(file, pos, len, page);
1041 } while (r == -EAGAIN);
1042
1043 return r;
1044}
1045
1046/*
1047 * we don't do anything in here that simple_write_end doesn't do
1048 * except adjust dirty page accounting and drop read lock on
1049 * mdsc->snap_rwsem.
1050 */
1051static int ceph_write_end(struct file *file, struct address_space *mapping,
1052 loff_t pos, unsigned len, unsigned copied,
1053 struct page *page, void *fsdata)
1054{
1055 struct inode *inode = file->f_dentry->d_inode;
1056 struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
1057 struct ceph_mds_client *mdsc = fsc->mdsc;
1058 unsigned from = pos & (PAGE_CACHE_SIZE - 1);
1059 int check_cap = 0;
1060
1061 dout("write_end file %p inode %p page %p %d~%d (%d)\n", file,
1062 inode, page, (int)pos, (int)copied, (int)len);
1063
1064 /* zero the stale part of the page if we did a short copy */
1065 if (copied < len)
1066 zero_user_segment(page, from+copied, len);
1067
1068 /* did file size increase? */
1069 /* (no need for i_size_read(); we caller holds i_mutex */
1070 if (pos+copied > inode->i_size)
1071 check_cap = ceph_inode_set_size(inode, pos+copied);
1072
1073 if (!PageUptodate(page))
1074 SetPageUptodate(page);
1075
1076 set_page_dirty(page);
1077
1078 unlock_page(page);
1079 up_read(&mdsc->snap_rwsem);
1080 page_cache_release(page);
1081
1082 if (check_cap)
1083 ceph_check_caps(ceph_inode(inode), CHECK_CAPS_AUTHONLY, NULL);
1084
1085 return copied;
1086}
1087
1088/*
1089 * we set .direct_IO to indicate direct io is supported, but since we
1090 * intercept O_DIRECT reads and writes early, this function should
1091 * never get called.
1092 */
1093static ssize_t ceph_direct_io(int rw, struct kiocb *iocb,
1094 const struct iovec *iov,
1095 loff_t pos, unsigned long nr_segs)
1096{
1097 WARN_ON(1);
1098 return -EINVAL;
1099}
1100
1101const struct address_space_operations ceph_aops = {
1102 .readpage = ceph_readpage,
1103 .readpages = ceph_readpages,
1104 .writepage = ceph_writepage,
1105 .writepages = ceph_writepages_start,
1106 .write_begin = ceph_write_begin,
1107 .write_end = ceph_write_end,
1108 .set_page_dirty = ceph_set_page_dirty,
1109 .invalidatepage = ceph_invalidatepage,
1110 .releasepage = ceph_releasepage,
1111 .direct_IO = ceph_direct_io,
1112};
1113
1114
1115/*
1116 * vm ops
1117 */
1118
1119/*
1120 * Reuse write_begin here for simplicity.
1121 */
1122static int ceph_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
1123{
1124 struct inode *inode = vma->vm_file->f_dentry->d_inode;
1125 struct page *page = vmf->page;
1126 struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc;
1127 loff_t off = page->index << PAGE_CACHE_SHIFT;
1128 loff_t size, len;
1129 int ret;
1130
1131 size = i_size_read(inode);
1132 if (off + PAGE_CACHE_SIZE <= size)
1133 len = PAGE_CACHE_SIZE;
1134 else
1135 len = size & ~PAGE_CACHE_MASK;
1136
1137 dout("page_mkwrite %p %llu~%llu page %p idx %lu\n", inode,
1138 off, len, page, page->index);
1139
1140 lock_page(page);
1141
1142 ret = VM_FAULT_NOPAGE;
1143 if ((off > size) ||
1144 (page->mapping != inode->i_mapping))
1145 goto out;
1146
1147 ret = ceph_update_writeable_page(vma->vm_file, off, len, page);
1148 if (ret == 0) {
1149 /* success. we'll keep the page locked. */
1150 set_page_dirty(page);
1151 up_read(&mdsc->snap_rwsem);
1152 ret = VM_FAULT_LOCKED;
1153 } else {
1154 if (ret == -ENOMEM)
1155 ret = VM_FAULT_OOM;
1156 else
1157 ret = VM_FAULT_SIGBUS;
1158 }
1159out:
1160 dout("page_mkwrite %p %llu~%llu = %d\n", inode, off, len, ret);
1161 if (ret != VM_FAULT_LOCKED)
1162 unlock_page(page);
1163 return ret;
1164}
1165
1166static struct vm_operations_struct ceph_vmops = {
1167 .fault = filemap_fault,
1168 .page_mkwrite = ceph_page_mkwrite,
1169};
1170
1171int ceph_mmap(struct file *file, struct vm_area_struct *vma)
1172{
1173 struct address_space *mapping = file->f_mapping;
1174
1175 if (!mapping->a_ops->readpage)
1176 return -ENOEXEC;
1177 file_accessed(file);
1178 vma->vm_ops = &ceph_vmops;
1179 vma->vm_flags |= VM_CAN_NONLINEAR;
1180 return 0;
1181}