a268abfe60acd53d034b89d53139064ecaa687ac
[muen/linux.git] / fs / ceph / addr.c
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 "cache.h"
15 #include <linux/ceph/osd_client.h>
16
17 /*
18  * Ceph address space ops.
19  *
20  * There are a few funny things going on here.
21  *
22  * The page->private field is used to reference a struct
23  * ceph_snap_context for _every_ dirty page.  This indicates which
24  * snapshot the page was logically dirtied in, and thus which snap
25  * context needs to be associated with the osd write during writeback.
26  *
27  * Similarly, struct ceph_inode_info maintains a set of counters to
28  * count dirty pages on the inode.  In the absence of snapshots,
29  * i_wrbuffer_ref == i_wrbuffer_ref_head == the dirty page count.
30  *
31  * When a snapshot is taken (that is, when the client receives
32  * notification that a snapshot was taken), each inode with caps and
33  * with dirty pages (dirty pages implies there is a cap) gets a new
34  * ceph_cap_snap in the i_cap_snaps list (which is sorted in ascending
35  * order, new snaps go to the tail).  The i_wrbuffer_ref_head count is
36  * moved to capsnap->dirty. (Unless a sync write is currently in
37  * progress.  In that case, the capsnap is said to be "pending", new
38  * writes cannot start, and the capsnap isn't "finalized" until the
39  * write completes (or fails) and a final size/mtime for the inode for
40  * that snap can be settled upon.)  i_wrbuffer_ref_head is reset to 0.
41  *
42  * On writeback, we must submit writes to the osd IN SNAP ORDER.  So,
43  * we look for the first capsnap in i_cap_snaps and write out pages in
44  * that snap context _only_.  Then we move on to the next capsnap,
45  * eventually reaching the "live" or "head" context (i.e., pages that
46  * are not yet snapped) and are writing the most recently dirtied
47  * pages.
48  *
49  * Invalidate and so forth must take care to ensure the dirty page
50  * accounting is preserved.
51  */
52
53 #define CONGESTION_ON_THRESH(congestion_kb) (congestion_kb >> (PAGE_SHIFT-10))
54 #define CONGESTION_OFF_THRESH(congestion_kb)                            \
55         (CONGESTION_ON_THRESH(congestion_kb) -                          \
56          (CONGESTION_ON_THRESH(congestion_kb) >> 2))
57
58 static inline struct ceph_snap_context *page_snap_context(struct page *page)
59 {
60         if (PagePrivate(page))
61                 return (void *)page->private;
62         return NULL;
63 }
64
65 /*
66  * Dirty a page.  Optimistically adjust accounting, on the assumption
67  * that we won't race with invalidate.  If we do, readjust.
68  */
69 static int ceph_set_page_dirty(struct page *page)
70 {
71         struct address_space *mapping = page->mapping;
72         struct inode *inode;
73         struct ceph_inode_info *ci;
74         struct ceph_snap_context *snapc;
75         int ret;
76
77         if (unlikely(!mapping))
78                 return !TestSetPageDirty(page);
79
80         if (PageDirty(page)) {
81                 dout("%p set_page_dirty %p idx %lu -- already dirty\n",
82                      mapping->host, page, page->index);
83                 BUG_ON(!PagePrivate(page));
84                 return 0;
85         }
86
87         inode = mapping->host;
88         ci = ceph_inode(inode);
89
90         /* dirty the head */
91         spin_lock(&ci->i_ceph_lock);
92         BUG_ON(ci->i_wr_ref == 0); // caller should hold Fw reference
93         if (__ceph_have_pending_cap_snap(ci)) {
94                 struct ceph_cap_snap *capsnap =
95                                 list_last_entry(&ci->i_cap_snaps,
96                                                 struct ceph_cap_snap,
97                                                 ci_item);
98                 snapc = ceph_get_snap_context(capsnap->context);
99                 capsnap->dirty_pages++;
100         } else {
101                 BUG_ON(!ci->i_head_snapc);
102                 snapc = ceph_get_snap_context(ci->i_head_snapc);
103                 ++ci->i_wrbuffer_ref_head;
104         }
105         if (ci->i_wrbuffer_ref == 0)
106                 ihold(inode);
107         ++ci->i_wrbuffer_ref;
108         dout("%p set_page_dirty %p idx %lu head %d/%d -> %d/%d "
109              "snapc %p seq %lld (%d snaps)\n",
110              mapping->host, page, page->index,
111              ci->i_wrbuffer_ref-1, ci->i_wrbuffer_ref_head-1,
112              ci->i_wrbuffer_ref, ci->i_wrbuffer_ref_head,
113              snapc, snapc->seq, snapc->num_snaps);
114         spin_unlock(&ci->i_ceph_lock);
115
116         /*
117          * Reference snap context in page->private.  Also set
118          * PagePrivate so that we get invalidatepage callback.
119          */
120         BUG_ON(PagePrivate(page));
121         page->private = (unsigned long)snapc;
122         SetPagePrivate(page);
123
124         ret = __set_page_dirty_nobuffers(page);
125         WARN_ON(!PageLocked(page));
126         WARN_ON(!page->mapping);
127
128         return ret;
129 }
130
131 /*
132  * If we are truncating the full page (i.e. offset == 0), adjust the
133  * dirty page counters appropriately.  Only called if there is private
134  * data on the page.
135  */
136 static void ceph_invalidatepage(struct page *page, unsigned int offset,
137                                 unsigned int length)
138 {
139         struct inode *inode;
140         struct ceph_inode_info *ci;
141         struct ceph_snap_context *snapc = page_snap_context(page);
142
143         inode = page->mapping->host;
144         ci = ceph_inode(inode);
145
146         if (offset != 0 || length != PAGE_CACHE_SIZE) {
147                 dout("%p invalidatepage %p idx %lu partial dirty page %u~%u\n",
148                      inode, page, page->index, offset, length);
149                 return;
150         }
151
152         ceph_invalidate_fscache_page(inode, page);
153
154         if (!PagePrivate(page))
155                 return;
156
157         /*
158          * We can get non-dirty pages here due to races between
159          * set_page_dirty and truncate_complete_page; just spit out a
160          * warning, in case we end up with accounting problems later.
161          */
162         if (!PageDirty(page))
163                 pr_err("%p invalidatepage %p page not dirty\n", inode, page);
164
165         ClearPageChecked(page);
166
167         dout("%p invalidatepage %p idx %lu full dirty page\n",
168              inode, page, page->index);
169
170         ceph_put_wrbuffer_cap_refs(ci, 1, snapc);
171         ceph_put_snap_context(snapc);
172         page->private = 0;
173         ClearPagePrivate(page);
174 }
175
176 static int ceph_releasepage(struct page *page, gfp_t g)
177 {
178         struct inode *inode = page->mapping ? page->mapping->host : NULL;
179         dout("%p releasepage %p idx %lu\n", inode, page, page->index);
180         WARN_ON(PageDirty(page));
181
182         /* Can we release the page from the cache? */
183         if (!ceph_release_fscache_page(page, g))
184                 return 0;
185
186         return !PagePrivate(page);
187 }
188
189 /*
190  * read a single page, without unlocking it.
191  */
192 static int readpage_nounlock(struct file *filp, struct page *page)
193 {
194         struct inode *inode = file_inode(filp);
195         struct ceph_inode_info *ci = ceph_inode(inode);
196         struct ceph_osd_client *osdc =
197                 &ceph_inode_to_client(inode)->client->osdc;
198         int err = 0;
199         u64 off = page_offset(page);
200         u64 len = PAGE_CACHE_SIZE;
201
202         if (off >= i_size_read(inode)) {
203                 zero_user_segment(page, 0, PAGE_CACHE_SIZE);
204                 SetPageUptodate(page);
205                 return 0;
206         }
207
208         if (ci->i_inline_version != CEPH_INLINE_NONE) {
209                 /*
210                  * Uptodate inline data should have been added
211                  * into page cache while getting Fcr caps.
212                  */
213                 if (off == 0)
214                         return -EINVAL;
215                 zero_user_segment(page, 0, PAGE_CACHE_SIZE);
216                 SetPageUptodate(page);
217                 return 0;
218         }
219
220         err = ceph_readpage_from_fscache(inode, page);
221         if (err == 0)
222                 goto out;
223
224         dout("readpage inode %p file %p page %p index %lu\n",
225              inode, filp, page, page->index);
226         err = ceph_osdc_readpages(osdc, ceph_vino(inode), &ci->i_layout,
227                                   off, &len,
228                                   ci->i_truncate_seq, ci->i_truncate_size,
229                                   &page, 1, 0);
230         if (err == -ENOENT)
231                 err = 0;
232         if (err < 0) {
233                 SetPageError(page);
234                 ceph_fscache_readpage_cancel(inode, page);
235                 goto out;
236         }
237         if (err < PAGE_CACHE_SIZE)
238                 /* zero fill remainder of page */
239                 zero_user_segment(page, err, PAGE_CACHE_SIZE);
240         else
241                 flush_dcache_page(page);
242
243         SetPageUptodate(page);
244         ceph_readpage_to_fscache(inode, page);
245
246 out:
247         return err < 0 ? err : 0;
248 }
249
250 static int ceph_readpage(struct file *filp, struct page *page)
251 {
252         int r = readpage_nounlock(filp, page);
253         unlock_page(page);
254         return r;
255 }
256
257 /*
258  * Finish an async read(ahead) op.
259  */
260 static void finish_read(struct ceph_osd_request *req, struct ceph_msg *msg)
261 {
262         struct inode *inode = req->r_inode;
263         struct ceph_osd_data *osd_data;
264         int rc = req->r_result;
265         int bytes = le32_to_cpu(msg->hdr.data_len);
266         int num_pages;
267         int i;
268
269         dout("finish_read %p req %p rc %d bytes %d\n", inode, req, rc, bytes);
270
271         /* unlock all pages, zeroing any data we didn't read */
272         osd_data = osd_req_op_extent_osd_data(req, 0);
273         BUG_ON(osd_data->type != CEPH_OSD_DATA_TYPE_PAGES);
274         num_pages = calc_pages_for((u64)osd_data->alignment,
275                                         (u64)osd_data->length);
276         for (i = 0; i < num_pages; i++) {
277                 struct page *page = osd_data->pages[i];
278
279                 if (rc < 0)
280                         goto unlock;
281                 if (bytes < (int)PAGE_CACHE_SIZE) {
282                         /* zero (remainder of) page */
283                         int s = bytes < 0 ? 0 : bytes;
284                         zero_user_segment(page, s, PAGE_CACHE_SIZE);
285                 }
286                 dout("finish_read %p uptodate %p idx %lu\n", inode, page,
287                      page->index);
288                 flush_dcache_page(page);
289                 SetPageUptodate(page);
290                 ceph_readpage_to_fscache(inode, page);
291 unlock:
292                 unlock_page(page);
293                 page_cache_release(page);
294                 bytes -= PAGE_CACHE_SIZE;
295         }
296         kfree(osd_data->pages);
297 }
298
299 static void ceph_unlock_page_vector(struct page **pages, int num_pages)
300 {
301         int i;
302
303         for (i = 0; i < num_pages; i++)
304                 unlock_page(pages[i]);
305 }
306
307 /*
308  * start an async read(ahead) operation.  return nr_pages we submitted
309  * a read for on success, or negative error code.
310  */
311 static int start_read(struct inode *inode, struct list_head *page_list, int max)
312 {
313         struct ceph_osd_client *osdc =
314                 &ceph_inode_to_client(inode)->client->osdc;
315         struct ceph_inode_info *ci = ceph_inode(inode);
316         struct page *page = list_entry(page_list->prev, struct page, lru);
317         struct ceph_vino vino;
318         struct ceph_osd_request *req;
319         u64 off;
320         u64 len;
321         int i;
322         struct page **pages;
323         pgoff_t next_index;
324         int nr_pages = 0;
325         int ret;
326
327         off = (u64) page_offset(page);
328
329         /* count pages */
330         next_index = page->index;
331         list_for_each_entry_reverse(page, page_list, lru) {
332                 if (page->index != next_index)
333                         break;
334                 nr_pages++;
335                 next_index++;
336                 if (max && nr_pages == max)
337                         break;
338         }
339         len = nr_pages << PAGE_CACHE_SHIFT;
340         dout("start_read %p nr_pages %d is %lld~%lld\n", inode, nr_pages,
341              off, len);
342         vino = ceph_vino(inode);
343         req = ceph_osdc_new_request(osdc, &ci->i_layout, vino, off, &len,
344                                     0, 1, CEPH_OSD_OP_READ,
345                                     CEPH_OSD_FLAG_READ, NULL,
346                                     ci->i_truncate_seq, ci->i_truncate_size,
347                                     false);
348         if (IS_ERR(req))
349                 return PTR_ERR(req);
350
351         /* build page vector */
352         nr_pages = calc_pages_for(0, len);
353         pages = kmalloc(sizeof(*pages) * nr_pages, GFP_KERNEL);
354         ret = -ENOMEM;
355         if (!pages)
356                 goto out;
357         for (i = 0; i < nr_pages; ++i) {
358                 page = list_entry(page_list->prev, struct page, lru);
359                 BUG_ON(PageLocked(page));
360                 list_del(&page->lru);
361
362                 dout("start_read %p adding %p idx %lu\n", inode, page,
363                      page->index);
364                 if (add_to_page_cache_lru(page, &inode->i_data, page->index,
365                                           GFP_KERNEL)) {
366                         ceph_fscache_uncache_page(inode, page);
367                         page_cache_release(page);
368                         dout("start_read %p add_to_page_cache failed %p\n",
369                              inode, page);
370                         nr_pages = i;
371                         goto out_pages;
372                 }
373                 pages[i] = page;
374         }
375         osd_req_op_extent_osd_data_pages(req, 0, pages, len, 0, false, false);
376         req->r_callback = finish_read;
377         req->r_inode = inode;
378
379         ceph_osdc_build_request(req, off, NULL, vino.snap, NULL);
380
381         dout("start_read %p starting %p %lld~%lld\n", inode, req, off, len);
382         ret = ceph_osdc_start_request(osdc, req, false);
383         if (ret < 0)
384                 goto out_pages;
385         ceph_osdc_put_request(req);
386         return nr_pages;
387
388 out_pages:
389         ceph_unlock_page_vector(pages, nr_pages);
390         ceph_release_page_vector(pages, nr_pages);
391 out:
392         ceph_osdc_put_request(req);
393         return ret;
394 }
395
396
397 /*
398  * Read multiple pages.  Leave pages we don't read + unlock in page_list;
399  * the caller (VM) cleans them up.
400  */
401 static int ceph_readpages(struct file *file, struct address_space *mapping,
402                           struct list_head *page_list, unsigned nr_pages)
403 {
404         struct inode *inode = file_inode(file);
405         struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
406         int rc = 0;
407         int max = 0;
408
409         if (ceph_inode(inode)->i_inline_version != CEPH_INLINE_NONE)
410                 return -EINVAL;
411
412         rc = ceph_readpages_from_fscache(mapping->host, mapping, page_list,
413                                          &nr_pages);
414
415         if (rc == 0)
416                 goto out;
417
418         if (fsc->mount_options->rsize >= PAGE_CACHE_SIZE)
419                 max = (fsc->mount_options->rsize + PAGE_CACHE_SIZE - 1)
420                         >> PAGE_SHIFT;
421
422         dout("readpages %p file %p nr_pages %d max %d\n", inode,
423                 file, nr_pages,
424              max);
425         while (!list_empty(page_list)) {
426                 rc = start_read(inode, page_list, max);
427                 if (rc < 0)
428                         goto out;
429                 BUG_ON(rc == 0);
430         }
431 out:
432         ceph_fscache_readpages_cancel(inode, page_list);
433
434         dout("readpages %p file %p ret %d\n", inode, file, rc);
435         return rc;
436 }
437
438 /*
439  * Get ref for the oldest snapc for an inode with dirty data... that is, the
440  * only snap context we are allowed to write back.
441  */
442 static struct ceph_snap_context *get_oldest_context(struct inode *inode,
443                                                     loff_t *snap_size)
444 {
445         struct ceph_inode_info *ci = ceph_inode(inode);
446         struct ceph_snap_context *snapc = NULL;
447         struct ceph_cap_snap *capsnap = NULL;
448
449         spin_lock(&ci->i_ceph_lock);
450         list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) {
451                 dout(" cap_snap %p snapc %p has %d dirty pages\n", capsnap,
452                      capsnap->context, capsnap->dirty_pages);
453                 if (capsnap->dirty_pages) {
454                         snapc = ceph_get_snap_context(capsnap->context);
455                         if (snap_size)
456                                 *snap_size = capsnap->size;
457                         break;
458                 }
459         }
460         if (!snapc && ci->i_wrbuffer_ref_head) {
461                 snapc = ceph_get_snap_context(ci->i_head_snapc);
462                 dout(" head snapc %p has %d dirty pages\n",
463                      snapc, ci->i_wrbuffer_ref_head);
464         }
465         spin_unlock(&ci->i_ceph_lock);
466         return snapc;
467 }
468
469 /*
470  * Write a single page, but leave the page locked.
471  *
472  * If we get a write error, set the page error bit, but still adjust the
473  * dirty page accounting (i.e., page is no longer dirty).
474  */
475 static int writepage_nounlock(struct page *page, struct writeback_control *wbc)
476 {
477         struct inode *inode;
478         struct ceph_inode_info *ci;
479         struct ceph_fs_client *fsc;
480         struct ceph_osd_client *osdc;
481         struct ceph_snap_context *snapc, *oldest;
482         loff_t page_off = page_offset(page);
483         loff_t snap_size = -1;
484         long writeback_stat;
485         u64 truncate_size;
486         u32 truncate_seq;
487         int err = 0, len = PAGE_CACHE_SIZE;
488
489         dout("writepage %p idx %lu\n", page, page->index);
490
491         if (!page->mapping || !page->mapping->host) {
492                 dout("writepage %p - no mapping\n", page);
493                 return -EFAULT;
494         }
495         inode = page->mapping->host;
496         ci = ceph_inode(inode);
497         fsc = ceph_inode_to_client(inode);
498         osdc = &fsc->client->osdc;
499
500         /* verify this is a writeable snap context */
501         snapc = page_snap_context(page);
502         if (snapc == NULL) {
503                 dout("writepage %p page %p not dirty?\n", inode, page);
504                 goto out;
505         }
506         oldest = get_oldest_context(inode, &snap_size);
507         if (snapc->seq > oldest->seq) {
508                 dout("writepage %p page %p snapc %p not writeable - noop\n",
509                      inode, page, snapc);
510                 /* we should only noop if called by kswapd */
511                 WARN_ON((current->flags & PF_MEMALLOC) == 0);
512                 ceph_put_snap_context(oldest);
513                 goto out;
514         }
515         ceph_put_snap_context(oldest);
516
517         spin_lock(&ci->i_ceph_lock);
518         truncate_seq = ci->i_truncate_seq;
519         truncate_size = ci->i_truncate_size;
520         if (snap_size == -1)
521                 snap_size = i_size_read(inode);
522         spin_unlock(&ci->i_ceph_lock);
523
524         /* is this a partial page at end of file? */
525         if (page_off >= snap_size) {
526                 dout("%p page eof %llu\n", page, snap_size);
527                 goto out;
528         }
529         if (snap_size < page_off + len)
530                 len = snap_size - page_off;
531
532         dout("writepage %p page %p index %lu on %llu~%u snapc %p\n",
533              inode, page, page->index, page_off, len, snapc);
534
535         writeback_stat = atomic_long_inc_return(&fsc->writeback_count);
536         if (writeback_stat >
537             CONGESTION_ON_THRESH(fsc->mount_options->congestion_kb))
538                 set_bdi_congested(&fsc->backing_dev_info, BLK_RW_ASYNC);
539
540         ceph_readpage_to_fscache(inode, page);
541
542         set_page_writeback(page);
543         err = ceph_osdc_writepages(osdc, ceph_vino(inode),
544                                    &ci->i_layout, snapc,
545                                    page_off, len,
546                                    truncate_seq, truncate_size,
547                                    &inode->i_mtime, &page, 1);
548         if (err < 0) {
549                 dout("writepage setting page/mapping error %d %p\n", err, page);
550                 SetPageError(page);
551                 mapping_set_error(&inode->i_data, err);
552                 if (wbc)
553                         wbc->pages_skipped++;
554         } else {
555                 dout("writepage cleaned page %p\n", page);
556                 err = 0;  /* vfs expects us to return 0 */
557         }
558         page->private = 0;
559         ClearPagePrivate(page);
560         end_page_writeback(page);
561         ceph_put_wrbuffer_cap_refs(ci, 1, snapc);
562         ceph_put_snap_context(snapc);  /* page's reference */
563 out:
564         return err;
565 }
566
567 static int ceph_writepage(struct page *page, struct writeback_control *wbc)
568 {
569         int err;
570         struct inode *inode = page->mapping->host;
571         BUG_ON(!inode);
572         ihold(inode);
573         err = writepage_nounlock(page, wbc);
574         unlock_page(page);
575         iput(inode);
576         return err;
577 }
578
579
580 /*
581  * lame release_pages helper.  release_pages() isn't exported to
582  * modules.
583  */
584 static void ceph_release_pages(struct page **pages, int num)
585 {
586         struct pagevec pvec;
587         int i;
588
589         pagevec_init(&pvec, 0);
590         for (i = 0; i < num; i++) {
591                 if (pagevec_add(&pvec, pages[i]) == 0)
592                         pagevec_release(&pvec);
593         }
594         pagevec_release(&pvec);
595 }
596
597 /*
598  * async writeback completion handler.
599  *
600  * If we get an error, set the mapping error bit, but not the individual
601  * page error bits.
602  */
603 static void writepages_finish(struct ceph_osd_request *req,
604                               struct ceph_msg *msg)
605 {
606         struct inode *inode = req->r_inode;
607         struct ceph_inode_info *ci = ceph_inode(inode);
608         struct ceph_osd_data *osd_data;
609         unsigned wrote;
610         struct page *page;
611         int num_pages;
612         int i;
613         struct ceph_snap_context *snapc = req->r_snapc;
614         struct address_space *mapping = inode->i_mapping;
615         int rc = req->r_result;
616         u64 bytes = req->r_ops[0].extent.length;
617         struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
618         long writeback_stat;
619         unsigned issued = ceph_caps_issued(ci);
620
621         osd_data = osd_req_op_extent_osd_data(req, 0);
622         BUG_ON(osd_data->type != CEPH_OSD_DATA_TYPE_PAGES);
623         num_pages = calc_pages_for((u64)osd_data->alignment,
624                                         (u64)osd_data->length);
625         if (rc >= 0) {
626                 /*
627                  * Assume we wrote the pages we originally sent.  The
628                  * osd might reply with fewer pages if our writeback
629                  * raced with a truncation and was adjusted at the osd,
630                  * so don't believe the reply.
631                  */
632                 wrote = num_pages;
633         } else {
634                 wrote = 0;
635                 mapping_set_error(mapping, rc);
636         }
637         dout("writepages_finish %p rc %d bytes %llu wrote %d (pages)\n",
638              inode, rc, bytes, wrote);
639
640         /* clean all pages */
641         for (i = 0; i < num_pages; i++) {
642                 page = osd_data->pages[i];
643                 BUG_ON(!page);
644                 WARN_ON(!PageUptodate(page));
645
646                 writeback_stat =
647                         atomic_long_dec_return(&fsc->writeback_count);
648                 if (writeback_stat <
649                     CONGESTION_OFF_THRESH(fsc->mount_options->congestion_kb))
650                         clear_bdi_congested(&fsc->backing_dev_info,
651                                             BLK_RW_ASYNC);
652
653                 ceph_put_snap_context(page_snap_context(page));
654                 page->private = 0;
655                 ClearPagePrivate(page);
656                 dout("unlocking %d %p\n", i, page);
657                 end_page_writeback(page);
658
659                 /*
660                  * We lost the cache cap, need to truncate the page before
661                  * it is unlocked, otherwise we'd truncate it later in the
662                  * page truncation thread, possibly losing some data that
663                  * raced its way in
664                  */
665                 if ((issued & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) == 0)
666                         generic_error_remove_page(inode->i_mapping, page);
667
668                 unlock_page(page);
669         }
670         dout("%p wrote+cleaned %d pages\n", inode, wrote);
671         ceph_put_wrbuffer_cap_refs(ci, num_pages, snapc);
672
673         ceph_release_pages(osd_data->pages, num_pages);
674         if (osd_data->pages_from_pool)
675                 mempool_free(osd_data->pages,
676                              ceph_sb_to_client(inode->i_sb)->wb_pagevec_pool);
677         else
678                 kfree(osd_data->pages);
679         ceph_osdc_put_request(req);
680 }
681
682 /*
683  * initiate async writeback
684  */
685 static int ceph_writepages_start(struct address_space *mapping,
686                                  struct writeback_control *wbc)
687 {
688         struct inode *inode = mapping->host;
689         struct ceph_inode_info *ci = ceph_inode(inode);
690         struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
691         struct ceph_vino vino = ceph_vino(inode);
692         pgoff_t index, start, end;
693         int range_whole = 0;
694         int should_loop = 1;
695         pgoff_t max_pages = 0, max_pages_ever = 0;
696         struct ceph_snap_context *snapc = NULL, *last_snapc = NULL, *pgsnapc;
697         struct pagevec pvec;
698         int done = 0;
699         int rc = 0;
700         unsigned wsize = 1 << inode->i_blkbits;
701         struct ceph_osd_request *req = NULL;
702         int do_sync = 0;
703         loff_t snap_size, i_size;
704         u64 truncate_size;
705         u32 truncate_seq;
706
707         /*
708          * Include a 'sync' in the OSD request if this is a data
709          * integrity write (e.g., O_SYNC write or fsync()), or if our
710          * cap is being revoked.
711          */
712         if ((wbc->sync_mode == WB_SYNC_ALL) ||
713                 ceph_caps_revoking(ci, CEPH_CAP_FILE_BUFFER))
714                 do_sync = 1;
715         dout("writepages_start %p dosync=%d (mode=%s)\n",
716              inode, do_sync,
717              wbc->sync_mode == WB_SYNC_NONE ? "NONE" :
718              (wbc->sync_mode == WB_SYNC_ALL ? "ALL" : "HOLD"));
719
720         if (fsc->mount_state == CEPH_MOUNT_SHUTDOWN) {
721                 pr_warn("writepage_start %p on forced umount\n", inode);
722                 return -EIO; /* we're in a forced umount, don't write! */
723         }
724         if (fsc->mount_options->wsize && fsc->mount_options->wsize < wsize)
725                 wsize = fsc->mount_options->wsize;
726         if (wsize < PAGE_CACHE_SIZE)
727                 wsize = PAGE_CACHE_SIZE;
728         max_pages_ever = wsize >> PAGE_CACHE_SHIFT;
729
730         pagevec_init(&pvec, 0);
731
732         /* where to start/end? */
733         if (wbc->range_cyclic) {
734                 start = mapping->writeback_index; /* Start from prev offset */
735                 end = -1;
736                 dout(" cyclic, start at %lu\n", start);
737         } else {
738                 start = wbc->range_start >> PAGE_CACHE_SHIFT;
739                 end = wbc->range_end >> PAGE_CACHE_SHIFT;
740                 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
741                         range_whole = 1;
742                 should_loop = 0;
743                 dout(" not cyclic, %lu to %lu\n", start, end);
744         }
745         index = start;
746
747 retry:
748         /* find oldest snap context with dirty data */
749         ceph_put_snap_context(snapc);
750         snap_size = -1;
751         snapc = get_oldest_context(inode, &snap_size);
752         if (!snapc) {
753                 /* hmm, why does writepages get called when there
754                    is no dirty data? */
755                 dout(" no snap context with dirty data?\n");
756                 goto out;
757         }
758         dout(" oldest snapc is %p seq %lld (%d snaps)\n",
759              snapc, snapc->seq, snapc->num_snaps);
760
761         spin_lock(&ci->i_ceph_lock);
762         truncate_seq = ci->i_truncate_seq;
763         truncate_size = ci->i_truncate_size;
764         i_size = i_size_read(inode);
765         spin_unlock(&ci->i_ceph_lock);
766
767         if (last_snapc && snapc != last_snapc) {
768                 /* if we switched to a newer snapc, restart our scan at the
769                  * start of the original file range. */
770                 dout("  snapc differs from last pass, restarting at %lu\n",
771                      index);
772                 index = start;
773         }
774         last_snapc = snapc;
775
776         while (!done && index <= end) {
777                 unsigned i;
778                 int first;
779                 pgoff_t next;
780                 int pvec_pages, locked_pages;
781                 struct page **pages = NULL;
782                 mempool_t *pool = NULL; /* Becomes non-null if mempool used */
783                 struct page *page;
784                 int want;
785                 u64 offset, len;
786                 long writeback_stat;
787
788                 next = 0;
789                 locked_pages = 0;
790                 max_pages = max_pages_ever;
791
792 get_more_pages:
793                 first = -1;
794                 want = min(end - index,
795                            min((pgoff_t)PAGEVEC_SIZE,
796                                max_pages - (pgoff_t)locked_pages) - 1)
797                         + 1;
798                 pvec_pages = pagevec_lookup_tag(&pvec, mapping, &index,
799                                                 PAGECACHE_TAG_DIRTY,
800                                                 want);
801                 dout("pagevec_lookup_tag got %d\n", pvec_pages);
802                 if (!pvec_pages && !locked_pages)
803                         break;
804                 for (i = 0; i < pvec_pages && locked_pages < max_pages; i++) {
805                         page = pvec.pages[i];
806                         dout("? %p idx %lu\n", page, page->index);
807                         if (locked_pages == 0)
808                                 lock_page(page);  /* first page */
809                         else if (!trylock_page(page))
810                                 break;
811
812                         /* only dirty pages, or our accounting breaks */
813                         if (unlikely(!PageDirty(page)) ||
814                             unlikely(page->mapping != mapping)) {
815                                 dout("!dirty or !mapping %p\n", page);
816                                 unlock_page(page);
817                                 break;
818                         }
819                         if (!wbc->range_cyclic && page->index > end) {
820                                 dout("end of range %p\n", page);
821                                 done = 1;
822                                 unlock_page(page);
823                                 break;
824                         }
825                         if (next && (page->index != next)) {
826                                 dout("not consecutive %p\n", page);
827                                 unlock_page(page);
828                                 break;
829                         }
830                         if (wbc->sync_mode != WB_SYNC_NONE) {
831                                 dout("waiting on writeback %p\n", page);
832                                 wait_on_page_writeback(page);
833                         }
834                         if (page_offset(page) >=
835                             (snap_size == -1 ? i_size : snap_size)) {
836                                 dout("%p page eof %llu\n", page,
837                                      (snap_size == -1 ? i_size : snap_size));
838                                 done = 1;
839                                 unlock_page(page);
840                                 break;
841                         }
842                         if (PageWriteback(page)) {
843                                 dout("%p under writeback\n", page);
844                                 unlock_page(page);
845                                 break;
846                         }
847
848                         /* only if matching snap context */
849                         pgsnapc = page_snap_context(page);
850                         if (pgsnapc->seq > snapc->seq) {
851                                 dout("page snapc %p %lld > oldest %p %lld\n",
852                                      pgsnapc, pgsnapc->seq, snapc, snapc->seq);
853                                 unlock_page(page);
854                                 if (!locked_pages)
855                                         continue; /* keep looking for snap */
856                                 break;
857                         }
858
859                         if (!clear_page_dirty_for_io(page)) {
860                                 dout("%p !clear_page_dirty_for_io\n", page);
861                                 unlock_page(page);
862                                 break;
863                         }
864
865                         /*
866                          * We have something to write.  If this is
867                          * the first locked page this time through,
868                          * allocate an osd request and a page array
869                          * that it will use.
870                          */
871                         if (locked_pages == 0) {
872                                 BUG_ON(pages);
873                                 /* prepare async write request */
874                                 offset = (u64)page_offset(page);
875                                 len = wsize;
876                                 req = ceph_osdc_new_request(&fsc->client->osdc,
877                                                         &ci->i_layout, vino,
878                                                         offset, &len, 0,
879                                                         do_sync ? 2 : 1,
880                                                         CEPH_OSD_OP_WRITE,
881                                                         CEPH_OSD_FLAG_WRITE |
882                                                         CEPH_OSD_FLAG_ONDISK,
883                                                         snapc, truncate_seq,
884                                                         truncate_size, true);
885                                 if (IS_ERR(req)) {
886                                         rc = PTR_ERR(req);
887                                         unlock_page(page);
888                                         break;
889                                 }
890
891                                 if (do_sync)
892                                         osd_req_op_init(req, 1,
893                                                         CEPH_OSD_OP_STARTSYNC, 0);
894
895                                 req->r_callback = writepages_finish;
896                                 req->r_inode = inode;
897
898                                 max_pages = calc_pages_for(0, (u64)len);
899                                 pages = kmalloc(max_pages * sizeof (*pages),
900                                                 GFP_NOFS);
901                                 if (!pages) {
902                                         pool = fsc->wb_pagevec_pool;
903                                         pages = mempool_alloc(pool, GFP_NOFS);
904                                         BUG_ON(!pages);
905                                 }
906                         }
907
908                         /* note position of first page in pvec */
909                         if (first < 0)
910                                 first = i;
911                         dout("%p will write page %p idx %lu\n",
912                              inode, page, page->index);
913
914                         writeback_stat =
915                                atomic_long_inc_return(&fsc->writeback_count);
916                         if (writeback_stat > CONGESTION_ON_THRESH(
917                                     fsc->mount_options->congestion_kb)) {
918                                 set_bdi_congested(&fsc->backing_dev_info,
919                                                   BLK_RW_ASYNC);
920                         }
921
922                         set_page_writeback(page);
923                         pages[locked_pages] = page;
924                         locked_pages++;
925                         next = page->index + 1;
926                 }
927
928                 /* did we get anything? */
929                 if (!locked_pages)
930                         goto release_pvec_pages;
931                 if (i) {
932                         int j;
933                         BUG_ON(!locked_pages || first < 0);
934
935                         if (pvec_pages && i == pvec_pages &&
936                             locked_pages < max_pages) {
937                                 dout("reached end pvec, trying for more\n");
938                                 pagevec_reinit(&pvec);
939                                 goto get_more_pages;
940                         }
941
942                         /* shift unused pages over in the pvec...  we
943                          * will need to release them below. */
944                         for (j = i; j < pvec_pages; j++) {
945                                 dout(" pvec leftover page %p\n",
946                                      pvec.pages[j]);
947                                 pvec.pages[j-i+first] = pvec.pages[j];
948                         }
949                         pvec.nr -= i-first;
950                 }
951
952                 /* Format the osd request message and submit the write */
953                 offset = page_offset(pages[0]);
954                 len = (u64)locked_pages << PAGE_CACHE_SHIFT;
955                 if (snap_size == -1) {
956                         len = min(len, (u64)i_size_read(inode) - offset);
957                          /* writepages_finish() clears writeback pages
958                           * according to the data length, so make sure
959                           * data length covers all locked pages */
960                         len = max(len, 1 +
961                                 ((u64)(locked_pages - 1) << PAGE_CACHE_SHIFT));
962                 } else {
963                         len = min(len, snap_size - offset);
964                 }
965                 dout("writepages got %d pages at %llu~%llu\n",
966                      locked_pages, offset, len);
967
968                 osd_req_op_extent_osd_data_pages(req, 0, pages, len, 0,
969                                                         !!pool, false);
970
971                 pages = NULL;   /* request message now owns the pages array */
972                 pool = NULL;
973
974                 /* Update the write op length in case we changed it */
975
976                 osd_req_op_extent_update(req, 0, len);
977
978                 vino = ceph_vino(inode);
979                 ceph_osdc_build_request(req, offset, snapc, vino.snap,
980                                         &inode->i_mtime);
981
982                 rc = ceph_osdc_start_request(&fsc->client->osdc, req, true);
983                 BUG_ON(rc);
984                 req = NULL;
985
986                 /* continue? */
987                 index = next;
988                 wbc->nr_to_write -= locked_pages;
989                 if (wbc->nr_to_write <= 0)
990                         done = 1;
991
992 release_pvec_pages:
993                 dout("pagevec_release on %d pages (%p)\n", (int)pvec.nr,
994                      pvec.nr ? pvec.pages[0] : NULL);
995                 pagevec_release(&pvec);
996
997                 if (locked_pages && !done)
998                         goto retry;
999         }
1000
1001         if (should_loop && !done) {
1002                 /* more to do; loop back to beginning of file */
1003                 dout("writepages looping back to beginning of file\n");
1004                 should_loop = 0;
1005                 index = 0;
1006                 goto retry;
1007         }
1008
1009         if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
1010                 mapping->writeback_index = index;
1011
1012 out:
1013         if (req)
1014                 ceph_osdc_put_request(req);
1015         ceph_put_snap_context(snapc);
1016         dout("writepages done, rc = %d\n", rc);
1017         return rc;
1018 }
1019
1020
1021
1022 /*
1023  * See if a given @snapc is either writeable, or already written.
1024  */
1025 static int context_is_writeable_or_written(struct inode *inode,
1026                                            struct ceph_snap_context *snapc)
1027 {
1028         struct ceph_snap_context *oldest = get_oldest_context(inode, NULL);
1029         int ret = !oldest || snapc->seq <= oldest->seq;
1030
1031         ceph_put_snap_context(oldest);
1032         return ret;
1033 }
1034
1035 /*
1036  * We are only allowed to write into/dirty the page if the page is
1037  * clean, or already dirty within the same snap context.
1038  *
1039  * called with page locked.
1040  * return success with page locked,
1041  * or any failure (incl -EAGAIN) with page unlocked.
1042  */
1043 static int ceph_update_writeable_page(struct file *file,
1044                             loff_t pos, unsigned len,
1045                             struct page *page)
1046 {
1047         struct inode *inode = file_inode(file);
1048         struct ceph_inode_info *ci = ceph_inode(inode);
1049         loff_t page_off = pos & PAGE_CACHE_MASK;
1050         int pos_in_page = pos & ~PAGE_CACHE_MASK;
1051         int end_in_page = pos_in_page + len;
1052         loff_t i_size;
1053         int r;
1054         struct ceph_snap_context *snapc, *oldest;
1055
1056 retry_locked:
1057         /* writepages currently holds page lock, but if we change that later, */
1058         wait_on_page_writeback(page);
1059
1060         snapc = page_snap_context(page);
1061         if (snapc && snapc != ci->i_head_snapc) {
1062                 /*
1063                  * this page is already dirty in another (older) snap
1064                  * context!  is it writeable now?
1065                  */
1066                 oldest = get_oldest_context(inode, NULL);
1067
1068                 if (snapc->seq > oldest->seq) {
1069                         ceph_put_snap_context(oldest);
1070                         dout(" page %p snapc %p not current or oldest\n",
1071                              page, snapc);
1072                         /*
1073                          * queue for writeback, and wait for snapc to
1074                          * be writeable or written
1075                          */
1076                         snapc = ceph_get_snap_context(snapc);
1077                         unlock_page(page);
1078                         ceph_queue_writeback(inode);
1079                         r = wait_event_interruptible(ci->i_cap_wq,
1080                                context_is_writeable_or_written(inode, snapc));
1081                         ceph_put_snap_context(snapc);
1082                         if (r == -ERESTARTSYS)
1083                                 return r;
1084                         return -EAGAIN;
1085                 }
1086                 ceph_put_snap_context(oldest);
1087
1088                 /* yay, writeable, do it now (without dropping page lock) */
1089                 dout(" page %p snapc %p not current, but oldest\n",
1090                      page, snapc);
1091                 if (!clear_page_dirty_for_io(page))
1092                         goto retry_locked;
1093                 r = writepage_nounlock(page, NULL);
1094                 if (r < 0)
1095                         goto fail_nosnap;
1096                 goto retry_locked;
1097         }
1098
1099         if (PageUptodate(page)) {
1100                 dout(" page %p already uptodate\n", page);
1101                 return 0;
1102         }
1103
1104         /* full page? */
1105         if (pos_in_page == 0 && len == PAGE_CACHE_SIZE)
1106                 return 0;
1107
1108         /* past end of file? */
1109         i_size = inode->i_size;   /* caller holds i_mutex */
1110
1111         if (page_off >= i_size ||
1112             (pos_in_page == 0 && (pos+len) >= i_size &&
1113              end_in_page - pos_in_page != PAGE_CACHE_SIZE)) {
1114                 dout(" zeroing %p 0 - %d and %d - %d\n",
1115                      page, pos_in_page, end_in_page, (int)PAGE_CACHE_SIZE);
1116                 zero_user_segments(page,
1117                                    0, pos_in_page,
1118                                    end_in_page, PAGE_CACHE_SIZE);
1119                 return 0;
1120         }
1121
1122         /* we need to read it. */
1123         r = readpage_nounlock(file, page);
1124         if (r < 0)
1125                 goto fail_nosnap;
1126         goto retry_locked;
1127 fail_nosnap:
1128         unlock_page(page);
1129         return r;
1130 }
1131
1132 /*
1133  * We are only allowed to write into/dirty the page if the page is
1134  * clean, or already dirty within the same snap context.
1135  */
1136 static int ceph_write_begin(struct file *file, struct address_space *mapping,
1137                             loff_t pos, unsigned len, unsigned flags,
1138                             struct page **pagep, void **fsdata)
1139 {
1140         struct inode *inode = file_inode(file);
1141         struct page *page;
1142         pgoff_t index = pos >> PAGE_CACHE_SHIFT;
1143         int r;
1144
1145         do {
1146                 /* get a page */
1147                 page = grab_cache_page_write_begin(mapping, index, 0);
1148                 if (!page)
1149                         return -ENOMEM;
1150                 *pagep = page;
1151
1152                 dout("write_begin file %p inode %p page %p %d~%d\n", file,
1153                      inode, page, (int)pos, (int)len);
1154
1155                 r = ceph_update_writeable_page(file, pos, len, page);
1156                 if (r < 0)
1157                         page_cache_release(page);
1158                 else
1159                         *pagep = page;
1160         } while (r == -EAGAIN);
1161
1162         return r;
1163 }
1164
1165 /*
1166  * we don't do anything in here that simple_write_end doesn't do
1167  * except adjust dirty page accounting
1168  */
1169 static int ceph_write_end(struct file *file, struct address_space *mapping,
1170                           loff_t pos, unsigned len, unsigned copied,
1171                           struct page *page, void *fsdata)
1172 {
1173         struct inode *inode = file_inode(file);
1174         unsigned from = pos & (PAGE_CACHE_SIZE - 1);
1175         int check_cap = 0;
1176
1177         dout("write_end file %p inode %p page %p %d~%d (%d)\n", file,
1178              inode, page, (int)pos, (int)copied, (int)len);
1179
1180         /* zero the stale part of the page if we did a short copy */
1181         if (copied < len)
1182                 zero_user_segment(page, from+copied, len);
1183
1184         /* did file size increase? */
1185         /* (no need for i_size_read(); we caller holds i_mutex */
1186         if (pos+copied > inode->i_size)
1187                 check_cap = ceph_inode_set_size(inode, pos+copied);
1188
1189         if (!PageUptodate(page))
1190                 SetPageUptodate(page);
1191
1192         set_page_dirty(page);
1193
1194         unlock_page(page);
1195         page_cache_release(page);
1196
1197         if (check_cap)
1198                 ceph_check_caps(ceph_inode(inode), CHECK_CAPS_AUTHONLY, NULL);
1199
1200         return copied;
1201 }
1202
1203 /*
1204  * we set .direct_IO to indicate direct io is supported, but since we
1205  * intercept O_DIRECT reads and writes early, this function should
1206  * never get called.
1207  */
1208 static ssize_t ceph_direct_io(struct kiocb *iocb, struct iov_iter *iter,
1209                               loff_t pos)
1210 {
1211         WARN_ON(1);
1212         return -EINVAL;
1213 }
1214
1215 const struct address_space_operations ceph_aops = {
1216         .readpage = ceph_readpage,
1217         .readpages = ceph_readpages,
1218         .writepage = ceph_writepage,
1219         .writepages = ceph_writepages_start,
1220         .write_begin = ceph_write_begin,
1221         .write_end = ceph_write_end,
1222         .set_page_dirty = ceph_set_page_dirty,
1223         .invalidatepage = ceph_invalidatepage,
1224         .releasepage = ceph_releasepage,
1225         .direct_IO = ceph_direct_io,
1226 };
1227
1228
1229 /*
1230  * vm ops
1231  */
1232 static int ceph_filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1233 {
1234         struct inode *inode = file_inode(vma->vm_file);
1235         struct ceph_inode_info *ci = ceph_inode(inode);
1236         struct ceph_file_info *fi = vma->vm_file->private_data;
1237         struct page *pinned_page = NULL;
1238         loff_t off = vmf->pgoff << PAGE_CACHE_SHIFT;
1239         int want, got, ret;
1240
1241         dout("filemap_fault %p %llx.%llx %llu~%zd trying to get caps\n",
1242              inode, ceph_vinop(inode), off, (size_t)PAGE_CACHE_SIZE);
1243         if (fi->fmode & CEPH_FILE_MODE_LAZY)
1244                 want = CEPH_CAP_FILE_CACHE | CEPH_CAP_FILE_LAZYIO;
1245         else
1246                 want = CEPH_CAP_FILE_CACHE;
1247         while (1) {
1248                 got = 0;
1249                 ret = ceph_get_caps(ci, CEPH_CAP_FILE_RD, want,
1250                                     -1, &got, &pinned_page);
1251                 if (ret == 0)
1252                         break;
1253                 if (ret != -ERESTARTSYS) {
1254                         WARN_ON(1);
1255                         return VM_FAULT_SIGBUS;
1256                 }
1257         }
1258         dout("filemap_fault %p %llu~%zd got cap refs on %s\n",
1259              inode, off, (size_t)PAGE_CACHE_SIZE, ceph_cap_string(got));
1260
1261         if ((got & (CEPH_CAP_FILE_CACHE | CEPH_CAP_FILE_LAZYIO)) ||
1262             ci->i_inline_version == CEPH_INLINE_NONE)
1263                 ret = filemap_fault(vma, vmf);
1264         else
1265                 ret = -EAGAIN;
1266
1267         dout("filemap_fault %p %llu~%zd dropping cap refs on %s ret %d\n",
1268              inode, off, (size_t)PAGE_CACHE_SIZE, ceph_cap_string(got), ret);
1269         if (pinned_page)
1270                 page_cache_release(pinned_page);
1271         ceph_put_cap_refs(ci, got);
1272
1273         if (ret != -EAGAIN)
1274                 return ret;
1275
1276         /* read inline data */
1277         if (off >= PAGE_CACHE_SIZE) {
1278                 /* does not support inline data > PAGE_SIZE */
1279                 ret = VM_FAULT_SIGBUS;
1280         } else {
1281                 int ret1;
1282                 struct address_space *mapping = inode->i_mapping;
1283                 struct page *page = find_or_create_page(mapping, 0,
1284                                                 mapping_gfp_mask(mapping) &
1285                                                 ~__GFP_FS);
1286                 if (!page) {
1287                         ret = VM_FAULT_OOM;
1288                         goto out;
1289                 }
1290                 ret1 = __ceph_do_getattr(inode, page,
1291                                          CEPH_STAT_CAP_INLINE_DATA, true);
1292                 if (ret1 < 0 || off >= i_size_read(inode)) {
1293                         unlock_page(page);
1294                         page_cache_release(page);
1295                         ret = VM_FAULT_SIGBUS;
1296                         goto out;
1297                 }
1298                 if (ret1 < PAGE_CACHE_SIZE)
1299                         zero_user_segment(page, ret1, PAGE_CACHE_SIZE);
1300                 else
1301                         flush_dcache_page(page);
1302                 SetPageUptodate(page);
1303                 vmf->page = page;
1304                 ret = VM_FAULT_MAJOR | VM_FAULT_LOCKED;
1305         }
1306 out:
1307         dout("filemap_fault %p %llu~%zd read inline data ret %d\n",
1308              inode, off, (size_t)PAGE_CACHE_SIZE, ret);
1309         return ret;
1310 }
1311
1312 /*
1313  * Reuse write_begin here for simplicity.
1314  */
1315 static int ceph_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
1316 {
1317         struct inode *inode = file_inode(vma->vm_file);
1318         struct ceph_inode_info *ci = ceph_inode(inode);
1319         struct ceph_file_info *fi = vma->vm_file->private_data;
1320         struct ceph_cap_flush *prealloc_cf;
1321         struct page *page = vmf->page;
1322         loff_t off = page_offset(page);
1323         loff_t size = i_size_read(inode);
1324         size_t len;
1325         int want, got, ret;
1326
1327         prealloc_cf = ceph_alloc_cap_flush();
1328         if (!prealloc_cf)
1329                 return VM_FAULT_SIGBUS;
1330
1331         if (ci->i_inline_version != CEPH_INLINE_NONE) {
1332                 struct page *locked_page = NULL;
1333                 if (off == 0) {
1334                         lock_page(page);
1335                         locked_page = page;
1336                 }
1337                 ret = ceph_uninline_data(vma->vm_file, locked_page);
1338                 if (locked_page)
1339                         unlock_page(locked_page);
1340                 if (ret < 0) {
1341                         ret = VM_FAULT_SIGBUS;
1342                         goto out_free;
1343                 }
1344         }
1345
1346         if (off + PAGE_CACHE_SIZE <= size)
1347                 len = PAGE_CACHE_SIZE;
1348         else
1349                 len = size & ~PAGE_CACHE_MASK;
1350
1351         dout("page_mkwrite %p %llx.%llx %llu~%zd getting caps i_size %llu\n",
1352              inode, ceph_vinop(inode), off, len, size);
1353         if (fi->fmode & CEPH_FILE_MODE_LAZY)
1354                 want = CEPH_CAP_FILE_BUFFER | CEPH_CAP_FILE_LAZYIO;
1355         else
1356                 want = CEPH_CAP_FILE_BUFFER;
1357         while (1) {
1358                 got = 0;
1359                 ret = ceph_get_caps(ci, CEPH_CAP_FILE_WR, want, off + len,
1360                                     &got, NULL);
1361                 if (ret == 0)
1362                         break;
1363                 if (ret != -ERESTARTSYS) {
1364                         WARN_ON(1);
1365                         ret = VM_FAULT_SIGBUS;
1366                         goto out_free;
1367                 }
1368         }
1369         dout("page_mkwrite %p %llu~%zd got cap refs on %s\n",
1370              inode, off, len, ceph_cap_string(got));
1371
1372         /* Update time before taking page lock */
1373         file_update_time(vma->vm_file);
1374
1375         lock_page(page);
1376
1377         ret = VM_FAULT_NOPAGE;
1378         if ((off > size) ||
1379             (page->mapping != inode->i_mapping))
1380                 goto out;
1381
1382         ret = ceph_update_writeable_page(vma->vm_file, off, len, page);
1383         if (ret == 0) {
1384                 /* success.  we'll keep the page locked. */
1385                 set_page_dirty(page);
1386                 ret = VM_FAULT_LOCKED;
1387         } else {
1388                 if (ret == -ENOMEM)
1389                         ret = VM_FAULT_OOM;
1390                 else
1391                         ret = VM_FAULT_SIGBUS;
1392         }
1393 out:
1394         if (ret != VM_FAULT_LOCKED)
1395                 unlock_page(page);
1396         if (ret == VM_FAULT_LOCKED ||
1397             ci->i_inline_version != CEPH_INLINE_NONE) {
1398                 int dirty;
1399                 spin_lock(&ci->i_ceph_lock);
1400                 ci->i_inline_version = CEPH_INLINE_NONE;
1401                 dirty = __ceph_mark_dirty_caps(ci, CEPH_CAP_FILE_WR,
1402                                                &prealloc_cf);
1403                 spin_unlock(&ci->i_ceph_lock);
1404                 if (dirty)
1405                         __mark_inode_dirty(inode, dirty);
1406         }
1407
1408         dout("page_mkwrite %p %llu~%zd dropping cap refs on %s ret %d\n",
1409              inode, off, len, ceph_cap_string(got), ret);
1410         ceph_put_cap_refs(ci, got);
1411 out_free:
1412         ceph_free_cap_flush(prealloc_cf);
1413
1414         return ret;
1415 }
1416
1417 void ceph_fill_inline_data(struct inode *inode, struct page *locked_page,
1418                            char *data, size_t len)
1419 {
1420         struct address_space *mapping = inode->i_mapping;
1421         struct page *page;
1422
1423         if (locked_page) {
1424                 page = locked_page;
1425         } else {
1426                 if (i_size_read(inode) == 0)
1427                         return;
1428                 page = find_or_create_page(mapping, 0,
1429                                            mapping_gfp_mask(mapping) & ~__GFP_FS);
1430                 if (!page)
1431                         return;
1432                 if (PageUptodate(page)) {
1433                         unlock_page(page);
1434                         page_cache_release(page);
1435                         return;
1436                 }
1437         }
1438
1439         dout("fill_inline_data %p %llx.%llx len %zu locked_page %p\n",
1440              inode, ceph_vinop(inode), len, locked_page);
1441
1442         if (len > 0) {
1443                 void *kaddr = kmap_atomic(page);
1444                 memcpy(kaddr, data, len);
1445                 kunmap_atomic(kaddr);
1446         }
1447
1448         if (page != locked_page) {
1449                 if (len < PAGE_CACHE_SIZE)
1450                         zero_user_segment(page, len, PAGE_CACHE_SIZE);
1451                 else
1452                         flush_dcache_page(page);
1453
1454                 SetPageUptodate(page);
1455                 unlock_page(page);
1456                 page_cache_release(page);
1457         }
1458 }
1459
1460 int ceph_uninline_data(struct file *filp, struct page *locked_page)
1461 {
1462         struct inode *inode = file_inode(filp);
1463         struct ceph_inode_info *ci = ceph_inode(inode);
1464         struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
1465         struct ceph_osd_request *req;
1466         struct page *page = NULL;
1467         u64 len, inline_version;
1468         int err = 0;
1469         bool from_pagecache = false;
1470
1471         spin_lock(&ci->i_ceph_lock);
1472         inline_version = ci->i_inline_version;
1473         spin_unlock(&ci->i_ceph_lock);
1474
1475         dout("uninline_data %p %llx.%llx inline_version %llu\n",
1476              inode, ceph_vinop(inode), inline_version);
1477
1478         if (inline_version == 1 || /* initial version, no data */
1479             inline_version == CEPH_INLINE_NONE)
1480                 goto out;
1481
1482         if (locked_page) {
1483                 page = locked_page;
1484                 WARN_ON(!PageUptodate(page));
1485         } else if (ceph_caps_issued(ci) &
1486                    (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) {
1487                 page = find_get_page(inode->i_mapping, 0);
1488                 if (page) {
1489                         if (PageUptodate(page)) {
1490                                 from_pagecache = true;
1491                                 lock_page(page);
1492                         } else {
1493                                 page_cache_release(page);
1494                                 page = NULL;
1495                         }
1496                 }
1497         }
1498
1499         if (page) {
1500                 len = i_size_read(inode);
1501                 if (len > PAGE_CACHE_SIZE)
1502                         len = PAGE_CACHE_SIZE;
1503         } else {
1504                 page = __page_cache_alloc(GFP_NOFS);
1505                 if (!page) {
1506                         err = -ENOMEM;
1507                         goto out;
1508                 }
1509                 err = __ceph_do_getattr(inode, page,
1510                                         CEPH_STAT_CAP_INLINE_DATA, true);
1511                 if (err < 0) {
1512                         /* no inline data */
1513                         if (err == -ENODATA)
1514                                 err = 0;
1515                         goto out;
1516                 }
1517                 len = err;
1518         }
1519
1520         req = ceph_osdc_new_request(&fsc->client->osdc, &ci->i_layout,
1521                                     ceph_vino(inode), 0, &len, 0, 1,
1522                                     CEPH_OSD_OP_CREATE,
1523                                     CEPH_OSD_FLAG_ONDISK | CEPH_OSD_FLAG_WRITE,
1524                                     ceph_empty_snapc, 0, 0, false);
1525         if (IS_ERR(req)) {
1526                 err = PTR_ERR(req);
1527                 goto out;
1528         }
1529
1530         ceph_osdc_build_request(req, 0, NULL, CEPH_NOSNAP, &inode->i_mtime);
1531         err = ceph_osdc_start_request(&fsc->client->osdc, req, false);
1532         if (!err)
1533                 err = ceph_osdc_wait_request(&fsc->client->osdc, req);
1534         ceph_osdc_put_request(req);
1535         if (err < 0)
1536                 goto out;
1537
1538         req = ceph_osdc_new_request(&fsc->client->osdc, &ci->i_layout,
1539                                     ceph_vino(inode), 0, &len, 1, 3,
1540                                     CEPH_OSD_OP_WRITE,
1541                                     CEPH_OSD_FLAG_ONDISK | CEPH_OSD_FLAG_WRITE,
1542                                     ceph_empty_snapc,
1543                                     ci->i_truncate_seq, ci->i_truncate_size,
1544                                     false);
1545         if (IS_ERR(req)) {
1546                 err = PTR_ERR(req);
1547                 goto out;
1548         }
1549
1550         osd_req_op_extent_osd_data_pages(req, 1, &page, len, 0, false, false);
1551
1552         {
1553                 __le64 xattr_buf = cpu_to_le64(inline_version);
1554                 err = osd_req_op_xattr_init(req, 0, CEPH_OSD_OP_CMPXATTR,
1555                                             "inline_version", &xattr_buf,
1556                                             sizeof(xattr_buf),
1557                                             CEPH_OSD_CMPXATTR_OP_GT,
1558                                             CEPH_OSD_CMPXATTR_MODE_U64);
1559                 if (err)
1560                         goto out_put;
1561         }
1562
1563         {
1564                 char xattr_buf[32];
1565                 int xattr_len = snprintf(xattr_buf, sizeof(xattr_buf),
1566                                          "%llu", inline_version);
1567                 err = osd_req_op_xattr_init(req, 2, CEPH_OSD_OP_SETXATTR,
1568                                             "inline_version",
1569                                             xattr_buf, xattr_len, 0, 0);
1570                 if (err)
1571                         goto out_put;
1572         }
1573
1574         ceph_osdc_build_request(req, 0, NULL, CEPH_NOSNAP, &inode->i_mtime);
1575         err = ceph_osdc_start_request(&fsc->client->osdc, req, false);
1576         if (!err)
1577                 err = ceph_osdc_wait_request(&fsc->client->osdc, req);
1578 out_put:
1579         ceph_osdc_put_request(req);
1580         if (err == -ECANCELED)
1581                 err = 0;
1582 out:
1583         if (page && page != locked_page) {
1584                 if (from_pagecache) {
1585                         unlock_page(page);
1586                         page_cache_release(page);
1587                 } else
1588                         __free_pages(page, 0);
1589         }
1590
1591         dout("uninline_data %p %llx.%llx inline_version %llu = %d\n",
1592              inode, ceph_vinop(inode), inline_version, err);
1593         return err;
1594 }
1595
1596 static const struct vm_operations_struct ceph_vmops = {
1597         .fault          = ceph_filemap_fault,
1598         .page_mkwrite   = ceph_page_mkwrite,
1599 };
1600
1601 int ceph_mmap(struct file *file, struct vm_area_struct *vma)
1602 {
1603         struct address_space *mapping = file->f_mapping;
1604
1605         if (!mapping->a_ops->readpage)
1606                 return -ENOEXEC;
1607         file_accessed(file);
1608         vma->vm_ops = &ceph_vmops;
1609         return 0;
1610 }
1611
1612 enum {
1613         POOL_READ       = 1,
1614         POOL_WRITE      = 2,
1615 };
1616
1617 static int __ceph_pool_perm_get(struct ceph_inode_info *ci, u32 pool)
1618 {
1619         struct ceph_fs_client *fsc = ceph_inode_to_client(&ci->vfs_inode);
1620         struct ceph_mds_client *mdsc = fsc->mdsc;
1621         struct ceph_osd_request *rd_req = NULL, *wr_req = NULL;
1622         struct rb_node **p, *parent;
1623         struct ceph_pool_perm *perm;
1624         struct page **pages;
1625         int err = 0, err2 = 0, have = 0;
1626
1627         down_read(&mdsc->pool_perm_rwsem);
1628         p = &mdsc->pool_perm_tree.rb_node;
1629         while (*p) {
1630                 perm = rb_entry(*p, struct ceph_pool_perm, node);
1631                 if (pool < perm->pool)
1632                         p = &(*p)->rb_left;
1633                 else if (pool > perm->pool)
1634                         p = &(*p)->rb_right;
1635                 else {
1636                         have = perm->perm;
1637                         break;
1638                 }
1639         }
1640         up_read(&mdsc->pool_perm_rwsem);
1641         if (*p)
1642                 goto out;
1643
1644         dout("__ceph_pool_perm_get pool %u no perm cached\n", pool);
1645
1646         down_write(&mdsc->pool_perm_rwsem);
1647         parent = NULL;
1648         while (*p) {
1649                 parent = *p;
1650                 perm = rb_entry(parent, struct ceph_pool_perm, node);
1651                 if (pool < perm->pool)
1652                         p = &(*p)->rb_left;
1653                 else if (pool > perm->pool)
1654                         p = &(*p)->rb_right;
1655                 else {
1656                         have = perm->perm;
1657                         break;
1658                 }
1659         }
1660         if (*p) {
1661                 up_write(&mdsc->pool_perm_rwsem);
1662                 goto out;
1663         }
1664
1665         rd_req = ceph_osdc_alloc_request(&fsc->client->osdc,
1666                                          ceph_empty_snapc,
1667                                          1, false, GFP_NOFS);
1668         if (!rd_req) {
1669                 err = -ENOMEM;
1670                 goto out_unlock;
1671         }
1672
1673         rd_req->r_flags = CEPH_OSD_FLAG_READ;
1674         osd_req_op_init(rd_req, 0, CEPH_OSD_OP_STAT, 0);
1675         rd_req->r_base_oloc.pool = pool;
1676         snprintf(rd_req->r_base_oid.name, sizeof(rd_req->r_base_oid.name),
1677                  "%llx.00000000", ci->i_vino.ino);
1678         rd_req->r_base_oid.name_len = strlen(rd_req->r_base_oid.name);
1679
1680         wr_req = ceph_osdc_alloc_request(&fsc->client->osdc,
1681                                          ceph_empty_snapc,
1682                                          1, false, GFP_NOFS);
1683         if (!wr_req) {
1684                 err = -ENOMEM;
1685                 goto out_unlock;
1686         }
1687
1688         wr_req->r_flags = CEPH_OSD_FLAG_WRITE |
1689                           CEPH_OSD_FLAG_ACK | CEPH_OSD_FLAG_ONDISK;
1690         osd_req_op_init(wr_req, 0, CEPH_OSD_OP_CREATE, CEPH_OSD_OP_FLAG_EXCL);
1691         wr_req->r_base_oloc.pool = pool;
1692         wr_req->r_base_oid = rd_req->r_base_oid;
1693
1694         /* one page should be large enough for STAT data */
1695         pages = ceph_alloc_page_vector(1, GFP_KERNEL);
1696         if (IS_ERR(pages)) {
1697                 err = PTR_ERR(pages);
1698                 goto out_unlock;
1699         }
1700
1701         osd_req_op_raw_data_in_pages(rd_req, 0, pages, PAGE_SIZE,
1702                                      0, false, true);
1703         ceph_osdc_build_request(rd_req, 0, NULL, CEPH_NOSNAP,
1704                                 &ci->vfs_inode.i_mtime);
1705         err = ceph_osdc_start_request(&fsc->client->osdc, rd_req, false);
1706
1707         ceph_osdc_build_request(wr_req, 0, NULL, CEPH_NOSNAP,
1708                                 &ci->vfs_inode.i_mtime);
1709         err2 = ceph_osdc_start_request(&fsc->client->osdc, wr_req, false);
1710
1711         if (!err)
1712                 err = ceph_osdc_wait_request(&fsc->client->osdc, rd_req);
1713         if (!err2)
1714                 err2 = ceph_osdc_wait_request(&fsc->client->osdc, wr_req);
1715
1716         if (err >= 0 || err == -ENOENT)
1717                 have |= POOL_READ;
1718         else if (err != -EPERM)
1719                 goto out_unlock;
1720
1721         if (err2 == 0 || err2 == -EEXIST)
1722                 have |= POOL_WRITE;
1723         else if (err2 != -EPERM) {
1724                 err = err2;
1725                 goto out_unlock;
1726         }
1727
1728         perm = kmalloc(sizeof(*perm), GFP_NOFS);
1729         if (!perm) {
1730                 err = -ENOMEM;
1731                 goto out_unlock;
1732         }
1733
1734         perm->pool = pool;
1735         perm->perm = have;
1736         rb_link_node(&perm->node, parent, p);
1737         rb_insert_color(&perm->node, &mdsc->pool_perm_tree);
1738         err = 0;
1739 out_unlock:
1740         up_write(&mdsc->pool_perm_rwsem);
1741
1742         if (rd_req)
1743                 ceph_osdc_put_request(rd_req);
1744         if (wr_req)
1745                 ceph_osdc_put_request(wr_req);
1746 out:
1747         if (!err)
1748                 err = have;
1749         dout("__ceph_pool_perm_get pool %u result = %d\n", pool, err);
1750         return err;
1751 }
1752
1753 int ceph_pool_perm_check(struct ceph_inode_info *ci, int need)
1754 {
1755         u32 pool;
1756         int ret, flags;
1757
1758         if (ceph_test_mount_opt(ceph_inode_to_client(&ci->vfs_inode),
1759                                 NOPOOLPERM))
1760                 return 0;
1761
1762         spin_lock(&ci->i_ceph_lock);
1763         flags = ci->i_ceph_flags;
1764         pool = ceph_file_layout_pg_pool(ci->i_layout);
1765         spin_unlock(&ci->i_ceph_lock);
1766 check:
1767         if (flags & CEPH_I_POOL_PERM) {
1768                 if ((need & CEPH_CAP_FILE_RD) && !(flags & CEPH_I_POOL_RD)) {
1769                         dout("ceph_pool_perm_check pool %u no read perm\n",
1770                              pool);
1771                         return -EPERM;
1772                 }
1773                 if ((need & CEPH_CAP_FILE_WR) && !(flags & CEPH_I_POOL_WR)) {
1774                         dout("ceph_pool_perm_check pool %u no write perm\n",
1775                              pool);
1776                         return -EPERM;
1777                 }
1778                 return 0;
1779         }
1780
1781         ret = __ceph_pool_perm_get(ci, pool);
1782         if (ret < 0)
1783                 return ret;
1784
1785         flags = CEPH_I_POOL_PERM;
1786         if (ret & POOL_READ)
1787                 flags |= CEPH_I_POOL_RD;
1788         if (ret & POOL_WRITE)
1789                 flags |= CEPH_I_POOL_WR;
1790
1791         spin_lock(&ci->i_ceph_lock);
1792         if (pool == ceph_file_layout_pg_pool(ci->i_layout)) {
1793                 ci->i_ceph_flags = flags;
1794         } else {
1795                 pool = ceph_file_layout_pg_pool(ci->i_layout);
1796                 flags = ci->i_ceph_flags;
1797         }
1798         spin_unlock(&ci->i_ceph_lock);
1799         goto check;
1800 }
1801
1802 void ceph_pool_perm_destroy(struct ceph_mds_client *mdsc)
1803 {
1804         struct ceph_pool_perm *perm;
1805         struct rb_node *n;
1806
1807         while (!RB_EMPTY_ROOT(&mdsc->pool_perm_tree)) {
1808                 n = rb_first(&mdsc->pool_perm_tree);
1809                 perm = rb_entry(n, struct ceph_pool_perm, node);
1810                 rb_erase(n, &mdsc->pool_perm_tree);
1811                 kfree(perm);
1812         }
1813 }