6471e28e0586b443513fb5261d951d521464359b
[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 && rc != ENOENT)
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 (ACCESS_ONCE(fsc->mount_state) == CEPH_MOUNT_SHUTDOWN) {
721                 pr_warn("writepage_start %p on forced umount\n", inode);
722                 truncate_pagecache(inode, 0);
723                 mapping_set_error(mapping, -EIO);
724                 return -EIO; /* we're in a forced umount, don't write! */
725         }
726         if (fsc->mount_options->wsize && fsc->mount_options->wsize < wsize)
727                 wsize = fsc->mount_options->wsize;
728         if (wsize < PAGE_CACHE_SIZE)
729                 wsize = PAGE_CACHE_SIZE;
730         max_pages_ever = wsize >> PAGE_CACHE_SHIFT;
731
732         pagevec_init(&pvec, 0);
733
734         /* where to start/end? */
735         if (wbc->range_cyclic) {
736                 start = mapping->writeback_index; /* Start from prev offset */
737                 end = -1;
738                 dout(" cyclic, start at %lu\n", start);
739         } else {
740                 start = wbc->range_start >> PAGE_CACHE_SHIFT;
741                 end = wbc->range_end >> PAGE_CACHE_SHIFT;
742                 if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
743                         range_whole = 1;
744                 should_loop = 0;
745                 dout(" not cyclic, %lu to %lu\n", start, end);
746         }
747         index = start;
748
749 retry:
750         /* find oldest snap context with dirty data */
751         ceph_put_snap_context(snapc);
752         snap_size = -1;
753         snapc = get_oldest_context(inode, &snap_size);
754         if (!snapc) {
755                 /* hmm, why does writepages get called when there
756                    is no dirty data? */
757                 dout(" no snap context with dirty data?\n");
758                 goto out;
759         }
760         dout(" oldest snapc is %p seq %lld (%d snaps)\n",
761              snapc, snapc->seq, snapc->num_snaps);
762
763         spin_lock(&ci->i_ceph_lock);
764         truncate_seq = ci->i_truncate_seq;
765         truncate_size = ci->i_truncate_size;
766         i_size = i_size_read(inode);
767         spin_unlock(&ci->i_ceph_lock);
768
769         if (last_snapc && snapc != last_snapc) {
770                 /* if we switched to a newer snapc, restart our scan at the
771                  * start of the original file range. */
772                 dout("  snapc differs from last pass, restarting at %lu\n",
773                      index);
774                 index = start;
775         }
776         last_snapc = snapc;
777
778         while (!done && index <= end) {
779                 unsigned i;
780                 int first;
781                 pgoff_t next;
782                 int pvec_pages, locked_pages;
783                 struct page **pages = NULL;
784                 mempool_t *pool = NULL; /* Becomes non-null if mempool used */
785                 struct page *page;
786                 int want;
787                 u64 offset, len;
788                 long writeback_stat;
789
790                 next = 0;
791                 locked_pages = 0;
792                 max_pages = max_pages_ever;
793
794 get_more_pages:
795                 first = -1;
796                 want = min(end - index,
797                            min((pgoff_t)PAGEVEC_SIZE,
798                                max_pages - (pgoff_t)locked_pages) - 1)
799                         + 1;
800                 pvec_pages = pagevec_lookup_tag(&pvec, mapping, &index,
801                                                 PAGECACHE_TAG_DIRTY,
802                                                 want);
803                 dout("pagevec_lookup_tag got %d\n", pvec_pages);
804                 if (!pvec_pages && !locked_pages)
805                         break;
806                 for (i = 0; i < pvec_pages && locked_pages < max_pages; i++) {
807                         page = pvec.pages[i];
808                         dout("? %p idx %lu\n", page, page->index);
809                         if (locked_pages == 0)
810                                 lock_page(page);  /* first page */
811                         else if (!trylock_page(page))
812                                 break;
813
814                         /* only dirty pages, or our accounting breaks */
815                         if (unlikely(!PageDirty(page)) ||
816                             unlikely(page->mapping != mapping)) {
817                                 dout("!dirty or !mapping %p\n", page);
818                                 unlock_page(page);
819                                 break;
820                         }
821                         if (!wbc->range_cyclic && page->index > end) {
822                                 dout("end of range %p\n", page);
823                                 done = 1;
824                                 unlock_page(page);
825                                 break;
826                         }
827                         if (next && (page->index != next)) {
828                                 dout("not consecutive %p\n", page);
829                                 unlock_page(page);
830                                 break;
831                         }
832                         if (wbc->sync_mode != WB_SYNC_NONE) {
833                                 dout("waiting on writeback %p\n", page);
834                                 wait_on_page_writeback(page);
835                         }
836                         if (page_offset(page) >=
837                             (snap_size == -1 ? i_size : snap_size)) {
838                                 dout("%p page eof %llu\n", page,
839                                      (snap_size == -1 ? i_size : snap_size));
840                                 done = 1;
841                                 unlock_page(page);
842                                 break;
843                         }
844                         if (PageWriteback(page)) {
845                                 dout("%p under writeback\n", page);
846                                 unlock_page(page);
847                                 break;
848                         }
849
850                         /* only if matching snap context */
851                         pgsnapc = page_snap_context(page);
852                         if (pgsnapc->seq > snapc->seq) {
853                                 dout("page snapc %p %lld > oldest %p %lld\n",
854                                      pgsnapc, pgsnapc->seq, snapc, snapc->seq);
855                                 unlock_page(page);
856                                 if (!locked_pages)
857                                         continue; /* keep looking for snap */
858                                 break;
859                         }
860
861                         if (!clear_page_dirty_for_io(page)) {
862                                 dout("%p !clear_page_dirty_for_io\n", page);
863                                 unlock_page(page);
864                                 break;
865                         }
866
867                         /*
868                          * We have something to write.  If this is
869                          * the first locked page this time through,
870                          * allocate an osd request and a page array
871                          * that it will use.
872                          */
873                         if (locked_pages == 0) {
874                                 BUG_ON(pages);
875                                 /* prepare async write request */
876                                 offset = (u64)page_offset(page);
877                                 len = wsize;
878                                 req = ceph_osdc_new_request(&fsc->client->osdc,
879                                                         &ci->i_layout, vino,
880                                                         offset, &len, 0,
881                                                         do_sync ? 2 : 1,
882                                                         CEPH_OSD_OP_WRITE,
883                                                         CEPH_OSD_FLAG_WRITE |
884                                                         CEPH_OSD_FLAG_ONDISK,
885                                                         snapc, truncate_seq,
886                                                         truncate_size, true);
887                                 if (IS_ERR(req)) {
888                                         rc = PTR_ERR(req);
889                                         unlock_page(page);
890                                         break;
891                                 }
892
893                                 if (do_sync)
894                                         osd_req_op_init(req, 1,
895                                                         CEPH_OSD_OP_STARTSYNC, 0);
896
897                                 req->r_callback = writepages_finish;
898                                 req->r_inode = inode;
899
900                                 max_pages = calc_pages_for(0, (u64)len);
901                                 pages = kmalloc(max_pages * sizeof (*pages),
902                                                 GFP_NOFS);
903                                 if (!pages) {
904                                         pool = fsc->wb_pagevec_pool;
905                                         pages = mempool_alloc(pool, GFP_NOFS);
906                                         BUG_ON(!pages);
907                                 }
908                         }
909
910                         /* note position of first page in pvec */
911                         if (first < 0)
912                                 first = i;
913                         dout("%p will write page %p idx %lu\n",
914                              inode, page, page->index);
915
916                         writeback_stat =
917                                atomic_long_inc_return(&fsc->writeback_count);
918                         if (writeback_stat > CONGESTION_ON_THRESH(
919                                     fsc->mount_options->congestion_kb)) {
920                                 set_bdi_congested(&fsc->backing_dev_info,
921                                                   BLK_RW_ASYNC);
922                         }
923
924                         set_page_writeback(page);
925                         pages[locked_pages] = page;
926                         locked_pages++;
927                         next = page->index + 1;
928                 }
929
930                 /* did we get anything? */
931                 if (!locked_pages)
932                         goto release_pvec_pages;
933                 if (i) {
934                         int j;
935                         BUG_ON(!locked_pages || first < 0);
936
937                         if (pvec_pages && i == pvec_pages &&
938                             locked_pages < max_pages) {
939                                 dout("reached end pvec, trying for more\n");
940                                 pagevec_reinit(&pvec);
941                                 goto get_more_pages;
942                         }
943
944                         /* shift unused pages over in the pvec...  we
945                          * will need to release them below. */
946                         for (j = i; j < pvec_pages; j++) {
947                                 dout(" pvec leftover page %p\n",
948                                      pvec.pages[j]);
949                                 pvec.pages[j-i+first] = pvec.pages[j];
950                         }
951                         pvec.nr -= i-first;
952                 }
953
954                 /* Format the osd request message and submit the write */
955                 offset = page_offset(pages[0]);
956                 len = (u64)locked_pages << PAGE_CACHE_SHIFT;
957                 if (snap_size == -1) {
958                         len = min(len, (u64)i_size_read(inode) - offset);
959                          /* writepages_finish() clears writeback pages
960                           * according to the data length, so make sure
961                           * data length covers all locked pages */
962                         len = max(len, 1 +
963                                 ((u64)(locked_pages - 1) << PAGE_CACHE_SHIFT));
964                 } else {
965                         len = min(len, snap_size - offset);
966                 }
967                 dout("writepages got %d pages at %llu~%llu\n",
968                      locked_pages, offset, len);
969
970                 osd_req_op_extent_osd_data_pages(req, 0, pages, len, 0,
971                                                         !!pool, false);
972
973                 pages = NULL;   /* request message now owns the pages array */
974                 pool = NULL;
975
976                 /* Update the write op length in case we changed it */
977
978                 osd_req_op_extent_update(req, 0, len);
979
980                 vino = ceph_vino(inode);
981                 ceph_osdc_build_request(req, offset, snapc, vino.snap,
982                                         &inode->i_mtime);
983
984                 rc = ceph_osdc_start_request(&fsc->client->osdc, req, true);
985                 BUG_ON(rc);
986                 req = NULL;
987
988                 /* continue? */
989                 index = next;
990                 wbc->nr_to_write -= locked_pages;
991                 if (wbc->nr_to_write <= 0)
992                         done = 1;
993
994 release_pvec_pages:
995                 dout("pagevec_release on %d pages (%p)\n", (int)pvec.nr,
996                      pvec.nr ? pvec.pages[0] : NULL);
997                 pagevec_release(&pvec);
998
999                 if (locked_pages && !done)
1000                         goto retry;
1001         }
1002
1003         if (should_loop && !done) {
1004                 /* more to do; loop back to beginning of file */
1005                 dout("writepages looping back to beginning of file\n");
1006                 should_loop = 0;
1007                 index = 0;
1008                 goto retry;
1009         }
1010
1011         if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
1012                 mapping->writeback_index = index;
1013
1014 out:
1015         if (req)
1016                 ceph_osdc_put_request(req);
1017         ceph_put_snap_context(snapc);
1018         dout("writepages done, rc = %d\n", rc);
1019         return rc;
1020 }
1021
1022
1023
1024 /*
1025  * See if a given @snapc is either writeable, or already written.
1026  */
1027 static int context_is_writeable_or_written(struct inode *inode,
1028                                            struct ceph_snap_context *snapc)
1029 {
1030         struct ceph_snap_context *oldest = get_oldest_context(inode, NULL);
1031         int ret = !oldest || snapc->seq <= oldest->seq;
1032
1033         ceph_put_snap_context(oldest);
1034         return ret;
1035 }
1036
1037 /*
1038  * We are only allowed to write into/dirty the page if the page is
1039  * clean, or already dirty within the same snap context.
1040  *
1041  * called with page locked.
1042  * return success with page locked,
1043  * or any failure (incl -EAGAIN) with page unlocked.
1044  */
1045 static int ceph_update_writeable_page(struct file *file,
1046                             loff_t pos, unsigned len,
1047                             struct page *page)
1048 {
1049         struct inode *inode = file_inode(file);
1050         struct ceph_inode_info *ci = ceph_inode(inode);
1051         loff_t page_off = pos & PAGE_CACHE_MASK;
1052         int pos_in_page = pos & ~PAGE_CACHE_MASK;
1053         int end_in_page = pos_in_page + len;
1054         loff_t i_size;
1055         int r;
1056         struct ceph_snap_context *snapc, *oldest;
1057
1058 retry_locked:
1059         /* writepages currently holds page lock, but if we change that later, */
1060         wait_on_page_writeback(page);
1061
1062         snapc = page_snap_context(page);
1063         if (snapc && snapc != ci->i_head_snapc) {
1064                 /*
1065                  * this page is already dirty in another (older) snap
1066                  * context!  is it writeable now?
1067                  */
1068                 oldest = get_oldest_context(inode, NULL);
1069
1070                 if (snapc->seq > oldest->seq) {
1071                         ceph_put_snap_context(oldest);
1072                         dout(" page %p snapc %p not current or oldest\n",
1073                              page, snapc);
1074                         /*
1075                          * queue for writeback, and wait for snapc to
1076                          * be writeable or written
1077                          */
1078                         snapc = ceph_get_snap_context(snapc);
1079                         unlock_page(page);
1080                         ceph_queue_writeback(inode);
1081                         r = wait_event_interruptible(ci->i_cap_wq,
1082                                context_is_writeable_or_written(inode, snapc));
1083                         ceph_put_snap_context(snapc);
1084                         if (r == -ERESTARTSYS)
1085                                 return r;
1086                         return -EAGAIN;
1087                 }
1088                 ceph_put_snap_context(oldest);
1089
1090                 /* yay, writeable, do it now (without dropping page lock) */
1091                 dout(" page %p snapc %p not current, but oldest\n",
1092                      page, snapc);
1093                 if (!clear_page_dirty_for_io(page))
1094                         goto retry_locked;
1095                 r = writepage_nounlock(page, NULL);
1096                 if (r < 0)
1097                         goto fail_nosnap;
1098                 goto retry_locked;
1099         }
1100
1101         if (PageUptodate(page)) {
1102                 dout(" page %p already uptodate\n", page);
1103                 return 0;
1104         }
1105
1106         /* full page? */
1107         if (pos_in_page == 0 && len == PAGE_CACHE_SIZE)
1108                 return 0;
1109
1110         /* past end of file? */
1111         i_size = inode->i_size;   /* caller holds i_mutex */
1112
1113         if (page_off >= i_size ||
1114             (pos_in_page == 0 && (pos+len) >= i_size &&
1115              end_in_page - pos_in_page != PAGE_CACHE_SIZE)) {
1116                 dout(" zeroing %p 0 - %d and %d - %d\n",
1117                      page, pos_in_page, end_in_page, (int)PAGE_CACHE_SIZE);
1118                 zero_user_segments(page,
1119                                    0, pos_in_page,
1120                                    end_in_page, PAGE_CACHE_SIZE);
1121                 return 0;
1122         }
1123
1124         /* we need to read it. */
1125         r = readpage_nounlock(file, page);
1126         if (r < 0)
1127                 goto fail_nosnap;
1128         goto retry_locked;
1129 fail_nosnap:
1130         unlock_page(page);
1131         return r;
1132 }
1133
1134 /*
1135  * We are only allowed to write into/dirty the page if the page is
1136  * clean, or already dirty within the same snap context.
1137  */
1138 static int ceph_write_begin(struct file *file, struct address_space *mapping,
1139                             loff_t pos, unsigned len, unsigned flags,
1140                             struct page **pagep, void **fsdata)
1141 {
1142         struct inode *inode = file_inode(file);
1143         struct page *page;
1144         pgoff_t index = pos >> PAGE_CACHE_SHIFT;
1145         int r;
1146
1147         do {
1148                 /* get a page */
1149                 page = grab_cache_page_write_begin(mapping, index, 0);
1150                 if (!page)
1151                         return -ENOMEM;
1152                 *pagep = page;
1153
1154                 dout("write_begin file %p inode %p page %p %d~%d\n", file,
1155                      inode, page, (int)pos, (int)len);
1156
1157                 r = ceph_update_writeable_page(file, pos, len, page);
1158                 if (r < 0)
1159                         page_cache_release(page);
1160                 else
1161                         *pagep = page;
1162         } while (r == -EAGAIN);
1163
1164         return r;
1165 }
1166
1167 /*
1168  * we don't do anything in here that simple_write_end doesn't do
1169  * except adjust dirty page accounting
1170  */
1171 static int ceph_write_end(struct file *file, struct address_space *mapping,
1172                           loff_t pos, unsigned len, unsigned copied,
1173                           struct page *page, void *fsdata)
1174 {
1175         struct inode *inode = file_inode(file);
1176         unsigned from = pos & (PAGE_CACHE_SIZE - 1);
1177         int check_cap = 0;
1178
1179         dout("write_end file %p inode %p page %p %d~%d (%d)\n", file,
1180              inode, page, (int)pos, (int)copied, (int)len);
1181
1182         /* zero the stale part of the page if we did a short copy */
1183         if (copied < len)
1184                 zero_user_segment(page, from+copied, len);
1185
1186         /* did file size increase? */
1187         /* (no need for i_size_read(); we caller holds i_mutex */
1188         if (pos+copied > inode->i_size)
1189                 check_cap = ceph_inode_set_size(inode, pos+copied);
1190
1191         if (!PageUptodate(page))
1192                 SetPageUptodate(page);
1193
1194         set_page_dirty(page);
1195
1196         unlock_page(page);
1197         page_cache_release(page);
1198
1199         if (check_cap)
1200                 ceph_check_caps(ceph_inode(inode), CHECK_CAPS_AUTHONLY, NULL);
1201
1202         return copied;
1203 }
1204
1205 /*
1206  * we set .direct_IO to indicate direct io is supported, but since we
1207  * intercept O_DIRECT reads and writes early, this function should
1208  * never get called.
1209  */
1210 static ssize_t ceph_direct_io(struct kiocb *iocb, struct iov_iter *iter,
1211                               loff_t pos)
1212 {
1213         WARN_ON(1);
1214         return -EINVAL;
1215 }
1216
1217 const struct address_space_operations ceph_aops = {
1218         .readpage = ceph_readpage,
1219         .readpages = ceph_readpages,
1220         .writepage = ceph_writepage,
1221         .writepages = ceph_writepages_start,
1222         .write_begin = ceph_write_begin,
1223         .write_end = ceph_write_end,
1224         .set_page_dirty = ceph_set_page_dirty,
1225         .invalidatepage = ceph_invalidatepage,
1226         .releasepage = ceph_releasepage,
1227         .direct_IO = ceph_direct_io,
1228 };
1229
1230
1231 /*
1232  * vm ops
1233  */
1234 static int ceph_filemap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
1235 {
1236         struct inode *inode = file_inode(vma->vm_file);
1237         struct ceph_inode_info *ci = ceph_inode(inode);
1238         struct ceph_file_info *fi = vma->vm_file->private_data;
1239         struct page *pinned_page = NULL;
1240         loff_t off = vmf->pgoff << PAGE_CACHE_SHIFT;
1241         int want, got, ret;
1242
1243         dout("filemap_fault %p %llx.%llx %llu~%zd trying to get caps\n",
1244              inode, ceph_vinop(inode), off, (size_t)PAGE_CACHE_SIZE);
1245         if (fi->fmode & CEPH_FILE_MODE_LAZY)
1246                 want = CEPH_CAP_FILE_CACHE | CEPH_CAP_FILE_LAZYIO;
1247         else
1248                 want = CEPH_CAP_FILE_CACHE;
1249         while (1) {
1250                 got = 0;
1251                 ret = ceph_get_caps(ci, CEPH_CAP_FILE_RD, want,
1252                                     -1, &got, &pinned_page);
1253                 if (ret == 0)
1254                         break;
1255                 if (ret != -ERESTARTSYS) {
1256                         WARN_ON(1);
1257                         return VM_FAULT_SIGBUS;
1258                 }
1259         }
1260         dout("filemap_fault %p %llu~%zd got cap refs on %s\n",
1261              inode, off, (size_t)PAGE_CACHE_SIZE, ceph_cap_string(got));
1262
1263         if ((got & (CEPH_CAP_FILE_CACHE | CEPH_CAP_FILE_LAZYIO)) ||
1264             ci->i_inline_version == CEPH_INLINE_NONE)
1265                 ret = filemap_fault(vma, vmf);
1266         else
1267                 ret = -EAGAIN;
1268
1269         dout("filemap_fault %p %llu~%zd dropping cap refs on %s ret %d\n",
1270              inode, off, (size_t)PAGE_CACHE_SIZE, ceph_cap_string(got), ret);
1271         if (pinned_page)
1272                 page_cache_release(pinned_page);
1273         ceph_put_cap_refs(ci, got);
1274
1275         if (ret != -EAGAIN)
1276                 return ret;
1277
1278         /* read inline data */
1279         if (off >= PAGE_CACHE_SIZE) {
1280                 /* does not support inline data > PAGE_SIZE */
1281                 ret = VM_FAULT_SIGBUS;
1282         } else {
1283                 int ret1;
1284                 struct address_space *mapping = inode->i_mapping;
1285                 struct page *page = find_or_create_page(mapping, 0,
1286                                                 mapping_gfp_mask(mapping) &
1287                                                 ~__GFP_FS);
1288                 if (!page) {
1289                         ret = VM_FAULT_OOM;
1290                         goto out;
1291                 }
1292                 ret1 = __ceph_do_getattr(inode, page,
1293                                          CEPH_STAT_CAP_INLINE_DATA, true);
1294                 if (ret1 < 0 || off >= i_size_read(inode)) {
1295                         unlock_page(page);
1296                         page_cache_release(page);
1297                         ret = VM_FAULT_SIGBUS;
1298                         goto out;
1299                 }
1300                 if (ret1 < PAGE_CACHE_SIZE)
1301                         zero_user_segment(page, ret1, PAGE_CACHE_SIZE);
1302                 else
1303                         flush_dcache_page(page);
1304                 SetPageUptodate(page);
1305                 vmf->page = page;
1306                 ret = VM_FAULT_MAJOR | VM_FAULT_LOCKED;
1307         }
1308 out:
1309         dout("filemap_fault %p %llu~%zd read inline data ret %d\n",
1310              inode, off, (size_t)PAGE_CACHE_SIZE, ret);
1311         return ret;
1312 }
1313
1314 /*
1315  * Reuse write_begin here for simplicity.
1316  */
1317 static int ceph_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
1318 {
1319         struct inode *inode = file_inode(vma->vm_file);
1320         struct ceph_inode_info *ci = ceph_inode(inode);
1321         struct ceph_file_info *fi = vma->vm_file->private_data;
1322         struct ceph_cap_flush *prealloc_cf;
1323         struct page *page = vmf->page;
1324         loff_t off = page_offset(page);
1325         loff_t size = i_size_read(inode);
1326         size_t len;
1327         int want, got, ret;
1328
1329         prealloc_cf = ceph_alloc_cap_flush();
1330         if (!prealloc_cf)
1331                 return VM_FAULT_SIGBUS;
1332
1333         if (ci->i_inline_version != CEPH_INLINE_NONE) {
1334                 struct page *locked_page = NULL;
1335                 if (off == 0) {
1336                         lock_page(page);
1337                         locked_page = page;
1338                 }
1339                 ret = ceph_uninline_data(vma->vm_file, locked_page);
1340                 if (locked_page)
1341                         unlock_page(locked_page);
1342                 if (ret < 0) {
1343                         ret = VM_FAULT_SIGBUS;
1344                         goto out_free;
1345                 }
1346         }
1347
1348         if (off + PAGE_CACHE_SIZE <= size)
1349                 len = PAGE_CACHE_SIZE;
1350         else
1351                 len = size & ~PAGE_CACHE_MASK;
1352
1353         dout("page_mkwrite %p %llx.%llx %llu~%zd getting caps i_size %llu\n",
1354              inode, ceph_vinop(inode), off, len, size);
1355         if (fi->fmode & CEPH_FILE_MODE_LAZY)
1356                 want = CEPH_CAP_FILE_BUFFER | CEPH_CAP_FILE_LAZYIO;
1357         else
1358                 want = CEPH_CAP_FILE_BUFFER;
1359         while (1) {
1360                 got = 0;
1361                 ret = ceph_get_caps(ci, CEPH_CAP_FILE_WR, want, off + len,
1362                                     &got, NULL);
1363                 if (ret == 0)
1364                         break;
1365                 if (ret != -ERESTARTSYS) {
1366                         WARN_ON(1);
1367                         ret = VM_FAULT_SIGBUS;
1368                         goto out_free;
1369                 }
1370         }
1371         dout("page_mkwrite %p %llu~%zd got cap refs on %s\n",
1372              inode, off, len, ceph_cap_string(got));
1373
1374         /* Update time before taking page lock */
1375         file_update_time(vma->vm_file);
1376
1377         lock_page(page);
1378
1379         ret = VM_FAULT_NOPAGE;
1380         if ((off > size) ||
1381             (page->mapping != inode->i_mapping))
1382                 goto out;
1383
1384         ret = ceph_update_writeable_page(vma->vm_file, off, len, page);
1385         if (ret == 0) {
1386                 /* success.  we'll keep the page locked. */
1387                 set_page_dirty(page);
1388                 ret = VM_FAULT_LOCKED;
1389         } else {
1390                 if (ret == -ENOMEM)
1391                         ret = VM_FAULT_OOM;
1392                 else
1393                         ret = VM_FAULT_SIGBUS;
1394         }
1395 out:
1396         if (ret != VM_FAULT_LOCKED)
1397                 unlock_page(page);
1398         if (ret == VM_FAULT_LOCKED ||
1399             ci->i_inline_version != CEPH_INLINE_NONE) {
1400                 int dirty;
1401                 spin_lock(&ci->i_ceph_lock);
1402                 ci->i_inline_version = CEPH_INLINE_NONE;
1403                 dirty = __ceph_mark_dirty_caps(ci, CEPH_CAP_FILE_WR,
1404                                                &prealloc_cf);
1405                 spin_unlock(&ci->i_ceph_lock);
1406                 if (dirty)
1407                         __mark_inode_dirty(inode, dirty);
1408         }
1409
1410         dout("page_mkwrite %p %llu~%zd dropping cap refs on %s ret %d\n",
1411              inode, off, len, ceph_cap_string(got), ret);
1412         ceph_put_cap_refs(ci, got);
1413 out_free:
1414         ceph_free_cap_flush(prealloc_cf);
1415
1416         return ret;
1417 }
1418
1419 void ceph_fill_inline_data(struct inode *inode, struct page *locked_page,
1420                            char *data, size_t len)
1421 {
1422         struct address_space *mapping = inode->i_mapping;
1423         struct page *page;
1424
1425         if (locked_page) {
1426                 page = locked_page;
1427         } else {
1428                 if (i_size_read(inode) == 0)
1429                         return;
1430                 page = find_or_create_page(mapping, 0,
1431                                            mapping_gfp_mask(mapping) & ~__GFP_FS);
1432                 if (!page)
1433                         return;
1434                 if (PageUptodate(page)) {
1435                         unlock_page(page);
1436                         page_cache_release(page);
1437                         return;
1438                 }
1439         }
1440
1441         dout("fill_inline_data %p %llx.%llx len %zu locked_page %p\n",
1442              inode, ceph_vinop(inode), len, locked_page);
1443
1444         if (len > 0) {
1445                 void *kaddr = kmap_atomic(page);
1446                 memcpy(kaddr, data, len);
1447                 kunmap_atomic(kaddr);
1448         }
1449
1450         if (page != locked_page) {
1451                 if (len < PAGE_CACHE_SIZE)
1452                         zero_user_segment(page, len, PAGE_CACHE_SIZE);
1453                 else
1454                         flush_dcache_page(page);
1455
1456                 SetPageUptodate(page);
1457                 unlock_page(page);
1458                 page_cache_release(page);
1459         }
1460 }
1461
1462 int ceph_uninline_data(struct file *filp, struct page *locked_page)
1463 {
1464         struct inode *inode = file_inode(filp);
1465         struct ceph_inode_info *ci = ceph_inode(inode);
1466         struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
1467         struct ceph_osd_request *req;
1468         struct page *page = NULL;
1469         u64 len, inline_version;
1470         int err = 0;
1471         bool from_pagecache = false;
1472
1473         spin_lock(&ci->i_ceph_lock);
1474         inline_version = ci->i_inline_version;
1475         spin_unlock(&ci->i_ceph_lock);
1476
1477         dout("uninline_data %p %llx.%llx inline_version %llu\n",
1478              inode, ceph_vinop(inode), inline_version);
1479
1480         if (inline_version == 1 || /* initial version, no data */
1481             inline_version == CEPH_INLINE_NONE)
1482                 goto out;
1483
1484         if (locked_page) {
1485                 page = locked_page;
1486                 WARN_ON(!PageUptodate(page));
1487         } else if (ceph_caps_issued(ci) &
1488                    (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) {
1489                 page = find_get_page(inode->i_mapping, 0);
1490                 if (page) {
1491                         if (PageUptodate(page)) {
1492                                 from_pagecache = true;
1493                                 lock_page(page);
1494                         } else {
1495                                 page_cache_release(page);
1496                                 page = NULL;
1497                         }
1498                 }
1499         }
1500
1501         if (page) {
1502                 len = i_size_read(inode);
1503                 if (len > PAGE_CACHE_SIZE)
1504                         len = PAGE_CACHE_SIZE;
1505         } else {
1506                 page = __page_cache_alloc(GFP_NOFS);
1507                 if (!page) {
1508                         err = -ENOMEM;
1509                         goto out;
1510                 }
1511                 err = __ceph_do_getattr(inode, page,
1512                                         CEPH_STAT_CAP_INLINE_DATA, true);
1513                 if (err < 0) {
1514                         /* no inline data */
1515                         if (err == -ENODATA)
1516                                 err = 0;
1517                         goto out;
1518                 }
1519                 len = err;
1520         }
1521
1522         req = ceph_osdc_new_request(&fsc->client->osdc, &ci->i_layout,
1523                                     ceph_vino(inode), 0, &len, 0, 1,
1524                                     CEPH_OSD_OP_CREATE,
1525                                     CEPH_OSD_FLAG_ONDISK | CEPH_OSD_FLAG_WRITE,
1526                                     ceph_empty_snapc, 0, 0, false);
1527         if (IS_ERR(req)) {
1528                 err = PTR_ERR(req);
1529                 goto out;
1530         }
1531
1532         ceph_osdc_build_request(req, 0, NULL, CEPH_NOSNAP, &inode->i_mtime);
1533         err = ceph_osdc_start_request(&fsc->client->osdc, req, false);
1534         if (!err)
1535                 err = ceph_osdc_wait_request(&fsc->client->osdc, req);
1536         ceph_osdc_put_request(req);
1537         if (err < 0)
1538                 goto out;
1539
1540         req = ceph_osdc_new_request(&fsc->client->osdc, &ci->i_layout,
1541                                     ceph_vino(inode), 0, &len, 1, 3,
1542                                     CEPH_OSD_OP_WRITE,
1543                                     CEPH_OSD_FLAG_ONDISK | CEPH_OSD_FLAG_WRITE,
1544                                     ceph_empty_snapc,
1545                                     ci->i_truncate_seq, ci->i_truncate_size,
1546                                     false);
1547         if (IS_ERR(req)) {
1548                 err = PTR_ERR(req);
1549                 goto out;
1550         }
1551
1552         osd_req_op_extent_osd_data_pages(req, 1, &page, len, 0, false, false);
1553
1554         {
1555                 __le64 xattr_buf = cpu_to_le64(inline_version);
1556                 err = osd_req_op_xattr_init(req, 0, CEPH_OSD_OP_CMPXATTR,
1557                                             "inline_version", &xattr_buf,
1558                                             sizeof(xattr_buf),
1559                                             CEPH_OSD_CMPXATTR_OP_GT,
1560                                             CEPH_OSD_CMPXATTR_MODE_U64);
1561                 if (err)
1562                         goto out_put;
1563         }
1564
1565         {
1566                 char xattr_buf[32];
1567                 int xattr_len = snprintf(xattr_buf, sizeof(xattr_buf),
1568                                          "%llu", inline_version);
1569                 err = osd_req_op_xattr_init(req, 2, CEPH_OSD_OP_SETXATTR,
1570                                             "inline_version",
1571                                             xattr_buf, xattr_len, 0, 0);
1572                 if (err)
1573                         goto out_put;
1574         }
1575
1576         ceph_osdc_build_request(req, 0, NULL, CEPH_NOSNAP, &inode->i_mtime);
1577         err = ceph_osdc_start_request(&fsc->client->osdc, req, false);
1578         if (!err)
1579                 err = ceph_osdc_wait_request(&fsc->client->osdc, req);
1580 out_put:
1581         ceph_osdc_put_request(req);
1582         if (err == -ECANCELED)
1583                 err = 0;
1584 out:
1585         if (page && page != locked_page) {
1586                 if (from_pagecache) {
1587                         unlock_page(page);
1588                         page_cache_release(page);
1589                 } else
1590                         __free_pages(page, 0);
1591         }
1592
1593         dout("uninline_data %p %llx.%llx inline_version %llu = %d\n",
1594              inode, ceph_vinop(inode), inline_version, err);
1595         return err;
1596 }
1597
1598 static struct vm_operations_struct ceph_vmops = {
1599         .fault          = ceph_filemap_fault,
1600         .page_mkwrite   = ceph_page_mkwrite,
1601 };
1602
1603 int ceph_mmap(struct file *file, struct vm_area_struct *vma)
1604 {
1605         struct address_space *mapping = file->f_mapping;
1606
1607         if (!mapping->a_ops->readpage)
1608                 return -ENOEXEC;
1609         file_accessed(file);
1610         vma->vm_ops = &ceph_vmops;
1611         return 0;
1612 }
1613
1614 enum {
1615         POOL_READ       = 1,
1616         POOL_WRITE      = 2,
1617 };
1618
1619 static int __ceph_pool_perm_get(struct ceph_inode_info *ci, u32 pool)
1620 {
1621         struct ceph_fs_client *fsc = ceph_inode_to_client(&ci->vfs_inode);
1622         struct ceph_mds_client *mdsc = fsc->mdsc;
1623         struct ceph_osd_request *rd_req = NULL, *wr_req = NULL;
1624         struct rb_node **p, *parent;
1625         struct ceph_pool_perm *perm;
1626         struct page **pages;
1627         int err = 0, err2 = 0, have = 0;
1628
1629         down_read(&mdsc->pool_perm_rwsem);
1630         p = &mdsc->pool_perm_tree.rb_node;
1631         while (*p) {
1632                 perm = rb_entry(*p, struct ceph_pool_perm, node);
1633                 if (pool < perm->pool)
1634                         p = &(*p)->rb_left;
1635                 else if (pool > perm->pool)
1636                         p = &(*p)->rb_right;
1637                 else {
1638                         have = perm->perm;
1639                         break;
1640                 }
1641         }
1642         up_read(&mdsc->pool_perm_rwsem);
1643         if (*p)
1644                 goto out;
1645
1646         dout("__ceph_pool_perm_get pool %u no perm cached\n", pool);
1647
1648         down_write(&mdsc->pool_perm_rwsem);
1649         parent = NULL;
1650         while (*p) {
1651                 parent = *p;
1652                 perm = rb_entry(parent, struct ceph_pool_perm, node);
1653                 if (pool < perm->pool)
1654                         p = &(*p)->rb_left;
1655                 else if (pool > perm->pool)
1656                         p = &(*p)->rb_right;
1657                 else {
1658                         have = perm->perm;
1659                         break;
1660                 }
1661         }
1662         if (*p) {
1663                 up_write(&mdsc->pool_perm_rwsem);
1664                 goto out;
1665         }
1666
1667         rd_req = ceph_osdc_alloc_request(&fsc->client->osdc,
1668                                          ceph_empty_snapc,
1669                                          1, false, GFP_NOFS);
1670         if (!rd_req) {
1671                 err = -ENOMEM;
1672                 goto out_unlock;
1673         }
1674
1675         rd_req->r_flags = CEPH_OSD_FLAG_READ;
1676         osd_req_op_init(rd_req, 0, CEPH_OSD_OP_STAT, 0);
1677         rd_req->r_base_oloc.pool = pool;
1678         snprintf(rd_req->r_base_oid.name, sizeof(rd_req->r_base_oid.name),
1679                  "%llx.00000000", ci->i_vino.ino);
1680         rd_req->r_base_oid.name_len = strlen(rd_req->r_base_oid.name);
1681
1682         wr_req = ceph_osdc_alloc_request(&fsc->client->osdc,
1683                                          ceph_empty_snapc,
1684                                          1, false, GFP_NOFS);
1685         if (!wr_req) {
1686                 err = -ENOMEM;
1687                 goto out_unlock;
1688         }
1689
1690         wr_req->r_flags = CEPH_OSD_FLAG_WRITE |
1691                           CEPH_OSD_FLAG_ACK | CEPH_OSD_FLAG_ONDISK;
1692         osd_req_op_init(wr_req, 0, CEPH_OSD_OP_CREATE, CEPH_OSD_OP_FLAG_EXCL);
1693         wr_req->r_base_oloc.pool = pool;
1694         wr_req->r_base_oid = rd_req->r_base_oid;
1695
1696         /* one page should be large enough for STAT data */
1697         pages = ceph_alloc_page_vector(1, GFP_KERNEL);
1698         if (IS_ERR(pages)) {
1699                 err = PTR_ERR(pages);
1700                 goto out_unlock;
1701         }
1702
1703         osd_req_op_raw_data_in_pages(rd_req, 0, pages, PAGE_SIZE,
1704                                      0, false, true);
1705         ceph_osdc_build_request(rd_req, 0, NULL, CEPH_NOSNAP,
1706                                 &ci->vfs_inode.i_mtime);
1707         err = ceph_osdc_start_request(&fsc->client->osdc, rd_req, false);
1708
1709         ceph_osdc_build_request(wr_req, 0, NULL, CEPH_NOSNAP,
1710                                 &ci->vfs_inode.i_mtime);
1711         err2 = ceph_osdc_start_request(&fsc->client->osdc, wr_req, false);
1712
1713         if (!err)
1714                 err = ceph_osdc_wait_request(&fsc->client->osdc, rd_req);
1715         if (!err2)
1716                 err2 = ceph_osdc_wait_request(&fsc->client->osdc, wr_req);
1717
1718         if (err >= 0 || err == -ENOENT)
1719                 have |= POOL_READ;
1720         else if (err != -EPERM)
1721                 goto out_unlock;
1722
1723         if (err2 == 0 || err2 == -EEXIST)
1724                 have |= POOL_WRITE;
1725         else if (err2 != -EPERM) {
1726                 err = err2;
1727                 goto out_unlock;
1728         }
1729
1730         perm = kmalloc(sizeof(*perm), GFP_NOFS);
1731         if (!perm) {
1732                 err = -ENOMEM;
1733                 goto out_unlock;
1734         }
1735
1736         perm->pool = pool;
1737         perm->perm = have;
1738         rb_link_node(&perm->node, parent, p);
1739         rb_insert_color(&perm->node, &mdsc->pool_perm_tree);
1740         err = 0;
1741 out_unlock:
1742         up_write(&mdsc->pool_perm_rwsem);
1743
1744         if (rd_req)
1745                 ceph_osdc_put_request(rd_req);
1746         if (wr_req)
1747                 ceph_osdc_put_request(wr_req);
1748 out:
1749         if (!err)
1750                 err = have;
1751         dout("__ceph_pool_perm_get pool %u result = %d\n", pool, err);
1752         return err;
1753 }
1754
1755 int ceph_pool_perm_check(struct ceph_inode_info *ci, int need)
1756 {
1757         u32 pool;
1758         int ret, flags;
1759
1760         if (ceph_test_mount_opt(ceph_inode_to_client(&ci->vfs_inode),
1761                                 NOPOOLPERM))
1762                 return 0;
1763
1764         spin_lock(&ci->i_ceph_lock);
1765         flags = ci->i_ceph_flags;
1766         pool = ceph_file_layout_pg_pool(ci->i_layout);
1767         spin_unlock(&ci->i_ceph_lock);
1768 check:
1769         if (flags & CEPH_I_POOL_PERM) {
1770                 if ((need & CEPH_CAP_FILE_RD) && !(flags & CEPH_I_POOL_RD)) {
1771                         dout("ceph_pool_perm_check pool %u no read perm\n",
1772                              pool);
1773                         return -EPERM;
1774                 }
1775                 if ((need & CEPH_CAP_FILE_WR) && !(flags & CEPH_I_POOL_WR)) {
1776                         dout("ceph_pool_perm_check pool %u no write perm\n",
1777                              pool);
1778                         return -EPERM;
1779                 }
1780                 return 0;
1781         }
1782
1783         ret = __ceph_pool_perm_get(ci, pool);
1784         if (ret < 0)
1785                 return ret;
1786
1787         flags = CEPH_I_POOL_PERM;
1788         if (ret & POOL_READ)
1789                 flags |= CEPH_I_POOL_RD;
1790         if (ret & POOL_WRITE)
1791                 flags |= CEPH_I_POOL_WR;
1792
1793         spin_lock(&ci->i_ceph_lock);
1794         if (pool == ceph_file_layout_pg_pool(ci->i_layout)) {
1795                 ci->i_ceph_flags = flags;
1796         } else {
1797                 pool = ceph_file_layout_pg_pool(ci->i_layout);
1798                 flags = ci->i_ceph_flags;
1799         }
1800         spin_unlock(&ci->i_ceph_lock);
1801         goto check;
1802 }
1803
1804 void ceph_pool_perm_destroy(struct ceph_mds_client *mdsc)
1805 {
1806         struct ceph_pool_perm *perm;
1807         struct rb_node *n;
1808
1809         while (!RB_EMPTY_ROOT(&mdsc->pool_perm_tree)) {
1810                 n = rb_first(&mdsc->pool_perm_tree);
1811                 perm = rb_entry(n, struct ceph_pool_perm, node);
1812                 rb_erase(n, &mdsc->pool_perm_tree);
1813                 kfree(perm);
1814         }
1815 }