Commit | Line | Data |
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1d3576fd SW |
1 | #include "ceph_debug.h" |
2 | ||
3 | #include <linux/backing-dev.h> | |
4 | #include <linux/fs.h> | |
5 | #include <linux/mm.h> | |
6 | #include <linux/pagemap.h> | |
7 | #include <linux/writeback.h> /* generic_writepages */ | |
5a0e3ad6 | 8 | #include <linux/slab.h> |
1d3576fd SW |
9 | #include <linux/pagevec.h> |
10 | #include <linux/task_io_accounting_ops.h> | |
11 | ||
12 | #include "super.h" | |
13 | #include "osd_client.h" | |
14 | ||
15 | /* | |
16 | * Ceph address space ops. | |
17 | * | |
18 | * There are a few funny things going on here. | |
19 | * | |
20 | * The page->private field is used to reference a struct | |
21 | * ceph_snap_context for _every_ dirty page. This indicates which | |
22 | * snapshot the page was logically dirtied in, and thus which snap | |
23 | * context needs to be associated with the osd write during writeback. | |
24 | * | |
25 | * Similarly, struct ceph_inode_info maintains a set of counters to | |
26 | * count dirty pages on the inode. In the absense of snapshots, | |
27 | * i_wrbuffer_ref == i_wrbuffer_ref_head == the dirty page count. | |
28 | * | |
29 | * When a snapshot is taken (that is, when the client receives | |
30 | * notification that a snapshot was taken), each inode with caps and | |
31 | * with dirty pages (dirty pages implies there is a cap) gets a new | |
32 | * ceph_cap_snap in the i_cap_snaps list (which is sorted in ascending | |
33 | * order, new snaps go to the tail). The i_wrbuffer_ref_head count is | |
34 | * moved to capsnap->dirty. (Unless a sync write is currently in | |
35 | * progress. In that case, the capsnap is said to be "pending", new | |
36 | * writes cannot start, and the capsnap isn't "finalized" until the | |
37 | * write completes (or fails) and a final size/mtime for the inode for | |
38 | * that snap can be settled upon.) i_wrbuffer_ref_head is reset to 0. | |
39 | * | |
40 | * On writeback, we must submit writes to the osd IN SNAP ORDER. So, | |
41 | * we look for the first capsnap in i_cap_snaps and write out pages in | |
42 | * that snap context _only_. Then we move on to the next capsnap, | |
43 | * eventually reaching the "live" or "head" context (i.e., pages that | |
44 | * are not yet snapped) and are writing the most recently dirtied | |
45 | * pages. | |
46 | * | |
47 | * Invalidate and so forth must take care to ensure the dirty page | |
48 | * accounting is preserved. | |
49 | */ | |
50 | ||
2baba250 YS |
51 | #define CONGESTION_ON_THRESH(congestion_kb) (congestion_kb >> (PAGE_SHIFT-10)) |
52 | #define CONGESTION_OFF_THRESH(congestion_kb) \ | |
53 | (CONGESTION_ON_THRESH(congestion_kb) - \ | |
54 | (CONGESTION_ON_THRESH(congestion_kb) >> 2)) | |
55 | ||
56 | ||
1d3576fd SW |
57 | |
58 | /* | |
59 | * Dirty a page. Optimistically adjust accounting, on the assumption | |
60 | * that we won't race with invalidate. If we do, readjust. | |
61 | */ | |
62 | static int ceph_set_page_dirty(struct page *page) | |
63 | { | |
64 | struct address_space *mapping = page->mapping; | |
65 | struct inode *inode; | |
66 | struct ceph_inode_info *ci; | |
67 | int undo = 0; | |
68 | struct ceph_snap_context *snapc; | |
69 | ||
70 | if (unlikely(!mapping)) | |
71 | return !TestSetPageDirty(page); | |
72 | ||
73 | if (TestSetPageDirty(page)) { | |
74 | dout("%p set_page_dirty %p idx %lu -- already dirty\n", | |
75 | mapping->host, page, page->index); | |
76 | return 0; | |
77 | } | |
78 | ||
79 | inode = mapping->host; | |
80 | ci = ceph_inode(inode); | |
81 | ||
82 | /* | |
83 | * Note that we're grabbing a snapc ref here without holding | |
84 | * any locks! | |
85 | */ | |
86 | snapc = ceph_get_snap_context(ci->i_snap_realm->cached_context); | |
87 | ||
88 | /* dirty the head */ | |
89 | spin_lock(&inode->i_lock); | |
90 | if (ci->i_wrbuffer_ref_head == 0) | |
91 | ci->i_head_snapc = ceph_get_snap_context(snapc); | |
92 | ++ci->i_wrbuffer_ref_head; | |
93 | if (ci->i_wrbuffer_ref == 0) | |
94 | igrab(inode); | |
95 | ++ci->i_wrbuffer_ref; | |
96 | dout("%p set_page_dirty %p idx %lu head %d/%d -> %d/%d " | |
97 | "snapc %p seq %lld (%d snaps)\n", | |
98 | mapping->host, page, page->index, | |
99 | ci->i_wrbuffer_ref-1, ci->i_wrbuffer_ref_head-1, | |
100 | ci->i_wrbuffer_ref, ci->i_wrbuffer_ref_head, | |
101 | snapc, snapc->seq, snapc->num_snaps); | |
102 | spin_unlock(&inode->i_lock); | |
103 | ||
104 | /* now adjust page */ | |
105 | spin_lock_irq(&mapping->tree_lock); | |
106 | if (page->mapping) { /* Race with truncate? */ | |
107 | WARN_ON_ONCE(!PageUptodate(page)); | |
679ceace | 108 | account_page_dirtied(page, page->mapping); |
1d3576fd SW |
109 | radix_tree_tag_set(&mapping->page_tree, |
110 | page_index(page), PAGECACHE_TAG_DIRTY); | |
111 | ||
112 | /* | |
113 | * Reference snap context in page->private. Also set | |
114 | * PagePrivate so that we get invalidatepage callback. | |
115 | */ | |
116 | page->private = (unsigned long)snapc; | |
117 | SetPagePrivate(page); | |
118 | } else { | |
119 | dout("ANON set_page_dirty %p (raced truncate?)\n", page); | |
120 | undo = 1; | |
121 | } | |
122 | ||
123 | spin_unlock_irq(&mapping->tree_lock); | |
124 | ||
125 | if (undo) | |
126 | /* whoops, we failed to dirty the page */ | |
127 | ceph_put_wrbuffer_cap_refs(ci, 1, snapc); | |
128 | ||
129 | __mark_inode_dirty(mapping->host, I_DIRTY_PAGES); | |
130 | ||
131 | BUG_ON(!PageDirty(page)); | |
132 | return 1; | |
133 | } | |
134 | ||
135 | /* | |
136 | * If we are truncating the full page (i.e. offset == 0), adjust the | |
137 | * dirty page counters appropriately. Only called if there is private | |
138 | * data on the page. | |
139 | */ | |
140 | static void ceph_invalidatepage(struct page *page, unsigned long offset) | |
141 | { | |
4ce1e9ad | 142 | struct inode *inode; |
1d3576fd SW |
143 | struct ceph_inode_info *ci; |
144 | struct ceph_snap_context *snapc = (void *)page->private; | |
145 | ||
146 | BUG_ON(!PageLocked(page)); | |
147 | BUG_ON(!page->private); | |
148 | BUG_ON(!PagePrivate(page)); | |
149 | BUG_ON(!page->mapping); | |
150 | ||
4ce1e9ad AB |
151 | inode = page->mapping->host; |
152 | ||
1d3576fd SW |
153 | /* |
154 | * We can get non-dirty pages here due to races between | |
155 | * set_page_dirty and truncate_complete_page; just spit out a | |
156 | * warning, in case we end up with accounting problems later. | |
157 | */ | |
158 | if (!PageDirty(page)) | |
159 | pr_err("%p invalidatepage %p page not dirty\n", inode, page); | |
160 | ||
161 | if (offset == 0) | |
162 | ClearPageChecked(page); | |
163 | ||
164 | ci = ceph_inode(inode); | |
165 | if (offset == 0) { | |
166 | dout("%p invalidatepage %p idx %lu full dirty page %lu\n", | |
167 | inode, page, page->index, offset); | |
168 | ceph_put_wrbuffer_cap_refs(ci, 1, snapc); | |
169 | ceph_put_snap_context(snapc); | |
170 | page->private = 0; | |
171 | ClearPagePrivate(page); | |
172 | } else { | |
173 | dout("%p invalidatepage %p idx %lu partial dirty page\n", | |
174 | inode, page, page->index); | |
175 | } | |
176 | } | |
177 | ||
178 | /* just a sanity check */ | |
179 | static int ceph_releasepage(struct page *page, gfp_t g) | |
180 | { | |
181 | struct inode *inode = page->mapping ? page->mapping->host : NULL; | |
182 | dout("%p releasepage %p idx %lu\n", inode, page, page->index); | |
183 | WARN_ON(PageDirty(page)); | |
184 | WARN_ON(page->private); | |
185 | WARN_ON(PagePrivate(page)); | |
186 | return 0; | |
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 = filp->f_dentry->d_inode; | |
195 | struct ceph_inode_info *ci = ceph_inode(inode); | |
196 | struct ceph_osd_client *osdc = &ceph_inode_to_client(inode)->osdc; | |
197 | int err = 0; | |
198 | u64 len = PAGE_CACHE_SIZE; | |
199 | ||
200 | dout("readpage inode %p file %p page %p index %lu\n", | |
201 | inode, filp, page, page->index); | |
202 | err = ceph_osdc_readpages(osdc, ceph_vino(inode), &ci->i_layout, | |
203 | page->index << PAGE_CACHE_SHIFT, &len, | |
204 | ci->i_truncate_seq, ci->i_truncate_size, | |
205 | &page, 1); | |
206 | if (err == -ENOENT) | |
207 | err = 0; | |
208 | if (err < 0) { | |
209 | SetPageError(page); | |
210 | goto out; | |
211 | } else if (err < PAGE_CACHE_SIZE) { | |
212 | /* zero fill remainder of page */ | |
213 | zero_user_segment(page, err, PAGE_CACHE_SIZE); | |
214 | } | |
215 | SetPageUptodate(page); | |
216 | ||
217 | out: | |
218 | return err < 0 ? err : 0; | |
219 | } | |
220 | ||
221 | static int ceph_readpage(struct file *filp, struct page *page) | |
222 | { | |
223 | int r = readpage_nounlock(filp, page); | |
224 | unlock_page(page); | |
225 | return r; | |
226 | } | |
227 | ||
228 | /* | |
229 | * Build a vector of contiguous pages from the provided page list. | |
230 | */ | |
231 | static struct page **page_vector_from_list(struct list_head *page_list, | |
232 | unsigned *nr_pages) | |
233 | { | |
234 | struct page **pages; | |
235 | struct page *page; | |
236 | int next_index, contig_pages = 0; | |
237 | ||
238 | /* build page vector */ | |
239 | pages = kmalloc(sizeof(*pages) * *nr_pages, GFP_NOFS); | |
240 | if (!pages) | |
241 | return ERR_PTR(-ENOMEM); | |
242 | ||
243 | BUG_ON(list_empty(page_list)); | |
244 | next_index = list_entry(page_list->prev, struct page, lru)->index; | |
245 | list_for_each_entry_reverse(page, page_list, lru) { | |
246 | if (page->index == next_index) { | |
247 | dout("readpages page %d %p\n", contig_pages, page); | |
248 | pages[contig_pages] = page; | |
249 | contig_pages++; | |
250 | next_index++; | |
251 | } else { | |
252 | break; | |
253 | } | |
254 | } | |
255 | *nr_pages = contig_pages; | |
256 | return pages; | |
257 | } | |
258 | ||
259 | /* | |
260 | * Read multiple pages. Leave pages we don't read + unlock in page_list; | |
261 | * the caller (VM) cleans them up. | |
262 | */ | |
263 | static int ceph_readpages(struct file *file, struct address_space *mapping, | |
264 | struct list_head *page_list, unsigned nr_pages) | |
265 | { | |
266 | struct inode *inode = file->f_dentry->d_inode; | |
267 | struct ceph_inode_info *ci = ceph_inode(inode); | |
268 | struct ceph_osd_client *osdc = &ceph_inode_to_client(inode)->osdc; | |
269 | int rc = 0; | |
270 | struct page **pages; | |
1d3576fd SW |
271 | loff_t offset; |
272 | u64 len; | |
273 | ||
274 | dout("readpages %p file %p nr_pages %d\n", | |
275 | inode, file, nr_pages); | |
276 | ||
277 | pages = page_vector_from_list(page_list, &nr_pages); | |
278 | if (IS_ERR(pages)) | |
279 | return PTR_ERR(pages); | |
280 | ||
281 | /* guess read extent */ | |
282 | offset = pages[0]->index << PAGE_CACHE_SHIFT; | |
283 | len = nr_pages << PAGE_CACHE_SHIFT; | |
284 | rc = ceph_osdc_readpages(osdc, ceph_vino(inode), &ci->i_layout, | |
285 | offset, &len, | |
286 | ci->i_truncate_seq, ci->i_truncate_size, | |
287 | pages, nr_pages); | |
288 | if (rc == -ENOENT) | |
289 | rc = 0; | |
290 | if (rc < 0) | |
291 | goto out; | |
292 | ||
1d3576fd SW |
293 | for (; !list_empty(page_list) && len > 0; |
294 | rc -= PAGE_CACHE_SIZE, len -= PAGE_CACHE_SIZE) { | |
295 | struct page *page = | |
296 | list_entry(page_list->prev, struct page, lru); | |
297 | ||
298 | list_del(&page->lru); | |
299 | ||
300 | if (rc < (int)PAGE_CACHE_SIZE) { | |
301 | /* zero (remainder of) page */ | |
302 | int s = rc < 0 ? 0 : rc; | |
303 | zero_user_segment(page, s, PAGE_CACHE_SIZE); | |
304 | } | |
305 | ||
213c99ee SW |
306 | if (add_to_page_cache_lru(page, mapping, page->index, |
307 | GFP_NOFS)) { | |
1d3576fd SW |
308 | page_cache_release(page); |
309 | dout("readpages %p add_to_page_cache failed %p\n", | |
310 | inode, page); | |
311 | continue; | |
312 | } | |
313 | dout("readpages %p adding %p idx %lu\n", inode, page, | |
314 | page->index); | |
315 | flush_dcache_page(page); | |
316 | SetPageUptodate(page); | |
317 | unlock_page(page); | |
31459fe4 | 318 | page_cache_release(page); |
1d3576fd | 319 | } |
1d3576fd SW |
320 | rc = 0; |
321 | ||
322 | out: | |
323 | kfree(pages); | |
324 | return rc; | |
325 | } | |
326 | ||
327 | /* | |
328 | * Get ref for the oldest snapc for an inode with dirty data... that is, the | |
329 | * only snap context we are allowed to write back. | |
1d3576fd | 330 | */ |
6298a337 SW |
331 | static struct ceph_snap_context *get_oldest_context(struct inode *inode, |
332 | u64 *snap_size) | |
1d3576fd SW |
333 | { |
334 | struct ceph_inode_info *ci = ceph_inode(inode); | |
335 | struct ceph_snap_context *snapc = NULL; | |
336 | struct ceph_cap_snap *capsnap = NULL; | |
337 | ||
6298a337 | 338 | spin_lock(&inode->i_lock); |
1d3576fd SW |
339 | list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) { |
340 | dout(" cap_snap %p snapc %p has %d dirty pages\n", capsnap, | |
341 | capsnap->context, capsnap->dirty_pages); | |
342 | if (capsnap->dirty_pages) { | |
343 | snapc = ceph_get_snap_context(capsnap->context); | |
344 | if (snap_size) | |
345 | *snap_size = capsnap->size; | |
346 | break; | |
347 | } | |
348 | } | |
80e755fe SW |
349 | if (!snapc && ci->i_head_snapc) { |
350 | snapc = ceph_get_snap_context(ci->i_head_snapc); | |
1d3576fd SW |
351 | dout(" head snapc %p has %d dirty pages\n", |
352 | snapc, ci->i_wrbuffer_ref_head); | |
353 | } | |
1d3576fd SW |
354 | spin_unlock(&inode->i_lock); |
355 | return snapc; | |
356 | } | |
357 | ||
358 | /* | |
359 | * Write a single page, but leave the page locked. | |
360 | * | |
361 | * If we get a write error, set the page error bit, but still adjust the | |
362 | * dirty page accounting (i.e., page is no longer dirty). | |
363 | */ | |
364 | static int writepage_nounlock(struct page *page, struct writeback_control *wbc) | |
365 | { | |
366 | struct inode *inode; | |
367 | struct ceph_inode_info *ci; | |
2baba250 | 368 | struct ceph_client *client; |
1d3576fd SW |
369 | struct ceph_osd_client *osdc; |
370 | loff_t page_off = page->index << PAGE_CACHE_SHIFT; | |
371 | int len = PAGE_CACHE_SIZE; | |
372 | loff_t i_size; | |
373 | int err = 0; | |
6298a337 | 374 | struct ceph_snap_context *snapc, *oldest; |
1d3576fd | 375 | u64 snap_size = 0; |
2baba250 | 376 | long writeback_stat; |
1d3576fd SW |
377 | |
378 | dout("writepage %p idx %lu\n", page, page->index); | |
379 | ||
380 | if (!page->mapping || !page->mapping->host) { | |
381 | dout("writepage %p - no mapping\n", page); | |
382 | return -EFAULT; | |
383 | } | |
384 | inode = page->mapping->host; | |
385 | ci = ceph_inode(inode); | |
2baba250 YS |
386 | client = ceph_inode_to_client(inode); |
387 | osdc = &client->osdc; | |
1d3576fd SW |
388 | |
389 | /* verify this is a writeable snap context */ | |
390 | snapc = (void *)page->private; | |
391 | if (snapc == NULL) { | |
392 | dout("writepage %p page %p not dirty?\n", inode, page); | |
393 | goto out; | |
394 | } | |
6298a337 SW |
395 | oldest = get_oldest_context(inode, &snap_size); |
396 | if (snapc->seq > oldest->seq) { | |
1d3576fd SW |
397 | dout("writepage %p page %p snapc %p not writeable - noop\n", |
398 | inode, page, (void *)page->private); | |
399 | /* we should only noop if called by kswapd */ | |
400 | WARN_ON((current->flags & PF_MEMALLOC) == 0); | |
6298a337 | 401 | ceph_put_snap_context(oldest); |
1d3576fd SW |
402 | goto out; |
403 | } | |
6298a337 | 404 | ceph_put_snap_context(oldest); |
1d3576fd SW |
405 | |
406 | /* is this a partial page at end of file? */ | |
407 | if (snap_size) | |
408 | i_size = snap_size; | |
409 | else | |
410 | i_size = i_size_read(inode); | |
411 | if (i_size < page_off + len) | |
412 | len = i_size - page_off; | |
413 | ||
414 | dout("writepage %p page %p index %lu on %llu~%u\n", | |
415 | inode, page, page->index, page_off, len); | |
416 | ||
2baba250 YS |
417 | writeback_stat = atomic_long_inc_return(&client->writeback_count); |
418 | if (writeback_stat > | |
419 | CONGESTION_ON_THRESH(client->mount_args->congestion_kb)) | |
420 | set_bdi_congested(&client->backing_dev_info, BLK_RW_ASYNC); | |
421 | ||
1d3576fd SW |
422 | set_page_writeback(page); |
423 | err = ceph_osdc_writepages(osdc, ceph_vino(inode), | |
424 | &ci->i_layout, snapc, | |
425 | page_off, len, | |
426 | ci->i_truncate_seq, ci->i_truncate_size, | |
427 | &inode->i_mtime, | |
428 | &page, 1, 0, 0, true); | |
429 | if (err < 0) { | |
430 | dout("writepage setting page/mapping error %d %p\n", err, page); | |
431 | SetPageError(page); | |
432 | mapping_set_error(&inode->i_data, err); | |
433 | if (wbc) | |
434 | wbc->pages_skipped++; | |
435 | } else { | |
436 | dout("writepage cleaned page %p\n", page); | |
437 | err = 0; /* vfs expects us to return 0 */ | |
438 | } | |
439 | page->private = 0; | |
440 | ClearPagePrivate(page); | |
441 | end_page_writeback(page); | |
442 | ceph_put_wrbuffer_cap_refs(ci, 1, snapc); | |
6298a337 | 443 | ceph_put_snap_context(snapc); /* page's reference */ |
1d3576fd SW |
444 | out: |
445 | return err; | |
446 | } | |
447 | ||
448 | static int ceph_writepage(struct page *page, struct writeback_control *wbc) | |
449 | { | |
dbd646a8 YS |
450 | int err; |
451 | struct inode *inode = page->mapping->host; | |
452 | BUG_ON(!inode); | |
453 | igrab(inode); | |
454 | err = writepage_nounlock(page, wbc); | |
1d3576fd | 455 | unlock_page(page); |
dbd646a8 | 456 | iput(inode); |
1d3576fd SW |
457 | return err; |
458 | } | |
459 | ||
460 | ||
461 | /* | |
462 | * lame release_pages helper. release_pages() isn't exported to | |
463 | * modules. | |
464 | */ | |
465 | static void ceph_release_pages(struct page **pages, int num) | |
466 | { | |
467 | struct pagevec pvec; | |
468 | int i; | |
469 | ||
470 | pagevec_init(&pvec, 0); | |
471 | for (i = 0; i < num; i++) { | |
472 | if (pagevec_add(&pvec, pages[i]) == 0) | |
473 | pagevec_release(&pvec); | |
474 | } | |
475 | pagevec_release(&pvec); | |
476 | } | |
477 | ||
478 | ||
479 | /* | |
480 | * async writeback completion handler. | |
481 | * | |
482 | * If we get an error, set the mapping error bit, but not the individual | |
483 | * page error bits. | |
484 | */ | |
485 | static void writepages_finish(struct ceph_osd_request *req, | |
486 | struct ceph_msg *msg) | |
487 | { | |
488 | struct inode *inode = req->r_inode; | |
489 | struct ceph_osd_reply_head *replyhead; | |
490 | struct ceph_osd_op *op; | |
491 | struct ceph_inode_info *ci = ceph_inode(inode); | |
492 | unsigned wrote; | |
1d3576fd SW |
493 | struct page *page; |
494 | int i; | |
495 | struct ceph_snap_context *snapc = req->r_snapc; | |
496 | struct address_space *mapping = inode->i_mapping; | |
1d3576fd SW |
497 | __s32 rc = -EIO; |
498 | u64 bytes = 0; | |
2baba250 YS |
499 | struct ceph_client *client = ceph_inode_to_client(inode); |
500 | long writeback_stat; | |
7ff899da | 501 | unsigned issued = ceph_caps_issued(ci); |
1d3576fd SW |
502 | |
503 | /* parse reply */ | |
504 | replyhead = msg->front.iov_base; | |
505 | WARN_ON(le32_to_cpu(replyhead->num_ops) == 0); | |
506 | op = (void *)(replyhead + 1); | |
507 | rc = le32_to_cpu(replyhead->result); | |
508 | bytes = le64_to_cpu(op->extent.length); | |
509 | ||
510 | if (rc >= 0) { | |
79788c69 SW |
511 | /* |
512 | * Assume we wrote the pages we originally sent. The | |
513 | * osd might reply with fewer pages if our writeback | |
514 | * raced with a truncation and was adjusted at the osd, | |
515 | * so don't believe the reply. | |
516 | */ | |
517 | wrote = req->r_num_pages; | |
1d3576fd SW |
518 | } else { |
519 | wrote = 0; | |
520 | mapping_set_error(mapping, rc); | |
521 | } | |
522 | dout("writepages_finish %p rc %d bytes %llu wrote %d (pages)\n", | |
523 | inode, rc, bytes, wrote); | |
524 | ||
525 | /* clean all pages */ | |
526 | for (i = 0; i < req->r_num_pages; i++) { | |
527 | page = req->r_pages[i]; | |
528 | BUG_ON(!page); | |
529 | WARN_ON(!PageUptodate(page)); | |
530 | ||
2baba250 YS |
531 | writeback_stat = |
532 | atomic_long_dec_return(&client->writeback_count); | |
533 | if (writeback_stat < | |
534 | CONGESTION_OFF_THRESH(client->mount_args->congestion_kb)) | |
535 | clear_bdi_congested(&client->backing_dev_info, | |
536 | BLK_RW_ASYNC); | |
537 | ||
80e755fe | 538 | ceph_put_snap_context((void *)page->private); |
1d3576fd SW |
539 | page->private = 0; |
540 | ClearPagePrivate(page); | |
1d3576fd SW |
541 | dout("unlocking %d %p\n", i, page); |
542 | end_page_writeback(page); | |
e63dc5c7 YS |
543 | |
544 | /* | |
545 | * We lost the cache cap, need to truncate the page before | |
546 | * it is unlocked, otherwise we'd truncate it later in the | |
547 | * page truncation thread, possibly losing some data that | |
548 | * raced its way in | |
549 | */ | |
2962507c | 550 | if ((issued & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) == 0) |
e63dc5c7 YS |
551 | generic_error_remove_page(inode->i_mapping, page); |
552 | ||
1d3576fd SW |
553 | unlock_page(page); |
554 | } | |
555 | dout("%p wrote+cleaned %d pages\n", inode, wrote); | |
556 | ceph_put_wrbuffer_cap_refs(ci, req->r_num_pages, snapc); | |
557 | ||
558 | ceph_release_pages(req->r_pages, req->r_num_pages); | |
559 | if (req->r_pages_from_pool) | |
560 | mempool_free(req->r_pages, | |
640ef79d | 561 | ceph_sb_to_client(inode->i_sb)->wb_pagevec_pool); |
1d3576fd SW |
562 | else |
563 | kfree(req->r_pages); | |
564 | ceph_osdc_put_request(req); | |
565 | } | |
566 | ||
567 | /* | |
568 | * allocate a page vec, either directly, or if necessary, via a the | |
569 | * mempool. we avoid the mempool if we can because req->r_num_pages | |
570 | * may be less than the maximum write size. | |
571 | */ | |
572 | static void alloc_page_vec(struct ceph_client *client, | |
573 | struct ceph_osd_request *req) | |
574 | { | |
575 | req->r_pages = kmalloc(sizeof(struct page *) * req->r_num_pages, | |
576 | GFP_NOFS); | |
577 | if (!req->r_pages) { | |
578 | req->r_pages = mempool_alloc(client->wb_pagevec_pool, GFP_NOFS); | |
579 | req->r_pages_from_pool = 1; | |
580 | WARN_ON(!req->r_pages); | |
581 | } | |
582 | } | |
583 | ||
584 | /* | |
585 | * initiate async writeback | |
586 | */ | |
587 | static int ceph_writepages_start(struct address_space *mapping, | |
588 | struct writeback_control *wbc) | |
589 | { | |
590 | struct inode *inode = mapping->host; | |
591 | struct backing_dev_info *bdi = mapping->backing_dev_info; | |
592 | struct ceph_inode_info *ci = ceph_inode(inode); | |
ec7384ec | 593 | struct ceph_client *client; |
1d3576fd SW |
594 | pgoff_t index, start, end; |
595 | int range_whole = 0; | |
596 | int should_loop = 1; | |
597 | pgoff_t max_pages = 0, max_pages_ever = 0; | |
80e755fe | 598 | struct ceph_snap_context *snapc = NULL, *last_snapc = NULL, *pgsnapc; |
1d3576fd SW |
599 | struct pagevec pvec; |
600 | int done = 0; | |
601 | int rc = 0; | |
602 | unsigned wsize = 1 << inode->i_blkbits; | |
603 | struct ceph_osd_request *req = NULL; | |
604 | int do_sync; | |
605 | u64 snap_size = 0; | |
606 | ||
607 | /* | |
608 | * Include a 'sync' in the OSD request if this is a data | |
609 | * integrity write (e.g., O_SYNC write or fsync()), or if our | |
610 | * cap is being revoked. | |
611 | */ | |
612 | do_sync = wbc->sync_mode == WB_SYNC_ALL; | |
613 | if (ceph_caps_revoking(ci, CEPH_CAP_FILE_BUFFER)) | |
614 | do_sync = 1; | |
615 | dout("writepages_start %p dosync=%d (mode=%s)\n", | |
616 | inode, do_sync, | |
617 | wbc->sync_mode == WB_SYNC_NONE ? "NONE" : | |
618 | (wbc->sync_mode == WB_SYNC_ALL ? "ALL" : "HOLD")); | |
619 | ||
620 | client = ceph_inode_to_client(inode); | |
621 | if (client->mount_state == CEPH_MOUNT_SHUTDOWN) { | |
622 | pr_warning("writepage_start %p on forced umount\n", inode); | |
623 | return -EIO; /* we're in a forced umount, don't write! */ | |
624 | } | |
6b805185 SW |
625 | if (client->mount_args->wsize && client->mount_args->wsize < wsize) |
626 | wsize = client->mount_args->wsize; | |
1d3576fd SW |
627 | if (wsize < PAGE_CACHE_SIZE) |
628 | wsize = PAGE_CACHE_SIZE; | |
629 | max_pages_ever = wsize >> PAGE_CACHE_SHIFT; | |
630 | ||
631 | pagevec_init(&pvec, 0); | |
632 | ||
633 | /* ?? */ | |
634 | if (wbc->nonblocking && bdi_write_congested(bdi)) { | |
635 | dout(" writepages congested\n"); | |
636 | wbc->encountered_congestion = 1; | |
637 | goto out_final; | |
638 | } | |
639 | ||
640 | /* where to start/end? */ | |
641 | if (wbc->range_cyclic) { | |
642 | start = mapping->writeback_index; /* Start from prev offset */ | |
643 | end = -1; | |
644 | dout(" cyclic, start at %lu\n", start); | |
645 | } else { | |
646 | start = wbc->range_start >> PAGE_CACHE_SHIFT; | |
647 | end = wbc->range_end >> PAGE_CACHE_SHIFT; | |
648 | if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) | |
649 | range_whole = 1; | |
650 | should_loop = 0; | |
651 | dout(" not cyclic, %lu to %lu\n", start, end); | |
652 | } | |
653 | index = start; | |
654 | ||
655 | retry: | |
656 | /* find oldest snap context with dirty data */ | |
657 | ceph_put_snap_context(snapc); | |
658 | snapc = get_oldest_context(inode, &snap_size); | |
659 | if (!snapc) { | |
660 | /* hmm, why does writepages get called when there | |
661 | is no dirty data? */ | |
662 | dout(" no snap context with dirty data?\n"); | |
663 | goto out; | |
664 | } | |
665 | dout(" oldest snapc is %p seq %lld (%d snaps)\n", | |
666 | snapc, snapc->seq, snapc->num_snaps); | |
667 | if (last_snapc && snapc != last_snapc) { | |
668 | /* if we switched to a newer snapc, restart our scan at the | |
669 | * start of the original file range. */ | |
670 | dout(" snapc differs from last pass, restarting at %lu\n", | |
671 | index); | |
672 | index = start; | |
673 | } | |
674 | last_snapc = snapc; | |
675 | ||
676 | while (!done && index <= end) { | |
677 | unsigned i; | |
678 | int first; | |
679 | pgoff_t next; | |
680 | int pvec_pages, locked_pages; | |
681 | struct page *page; | |
682 | int want; | |
683 | u64 offset, len; | |
684 | struct ceph_osd_request_head *reqhead; | |
685 | struct ceph_osd_op *op; | |
2baba250 | 686 | long writeback_stat; |
1d3576fd SW |
687 | |
688 | next = 0; | |
689 | locked_pages = 0; | |
690 | max_pages = max_pages_ever; | |
691 | ||
692 | get_more_pages: | |
693 | first = -1; | |
694 | want = min(end - index, | |
695 | min((pgoff_t)PAGEVEC_SIZE, | |
696 | max_pages - (pgoff_t)locked_pages) - 1) | |
697 | + 1; | |
698 | pvec_pages = pagevec_lookup_tag(&pvec, mapping, &index, | |
699 | PAGECACHE_TAG_DIRTY, | |
700 | want); | |
701 | dout("pagevec_lookup_tag got %d\n", pvec_pages); | |
702 | if (!pvec_pages && !locked_pages) | |
703 | break; | |
704 | for (i = 0; i < pvec_pages && locked_pages < max_pages; i++) { | |
705 | page = pvec.pages[i]; | |
706 | dout("? %p idx %lu\n", page, page->index); | |
707 | if (locked_pages == 0) | |
708 | lock_page(page); /* first page */ | |
709 | else if (!trylock_page(page)) | |
710 | break; | |
711 | ||
712 | /* only dirty pages, or our accounting breaks */ | |
713 | if (unlikely(!PageDirty(page)) || | |
714 | unlikely(page->mapping != mapping)) { | |
715 | dout("!dirty or !mapping %p\n", page); | |
716 | unlock_page(page); | |
717 | break; | |
718 | } | |
719 | if (!wbc->range_cyclic && page->index > end) { | |
720 | dout("end of range %p\n", page); | |
721 | done = 1; | |
722 | unlock_page(page); | |
723 | break; | |
724 | } | |
725 | if (next && (page->index != next)) { | |
726 | dout("not consecutive %p\n", page); | |
727 | unlock_page(page); | |
728 | break; | |
729 | } | |
730 | if (wbc->sync_mode != WB_SYNC_NONE) { | |
731 | dout("waiting on writeback %p\n", page); | |
732 | wait_on_page_writeback(page); | |
733 | } | |
734 | if ((snap_size && page_offset(page) > snap_size) || | |
735 | (!snap_size && | |
736 | page_offset(page) > i_size_read(inode))) { | |
737 | dout("%p page eof %llu\n", page, snap_size ? | |
738 | snap_size : i_size_read(inode)); | |
739 | done = 1; | |
740 | unlock_page(page); | |
741 | break; | |
742 | } | |
743 | if (PageWriteback(page)) { | |
744 | dout("%p under writeback\n", page); | |
745 | unlock_page(page); | |
746 | break; | |
747 | } | |
748 | ||
749 | /* only if matching snap context */ | |
80e755fe SW |
750 | pgsnapc = (void *)page->private; |
751 | if (pgsnapc->seq > snapc->seq) { | |
752 | dout("page snapc %p %lld > oldest %p %lld\n", | |
753 | pgsnapc, pgsnapc->seq, snapc, snapc->seq); | |
1d3576fd SW |
754 | unlock_page(page); |
755 | if (!locked_pages) | |
756 | continue; /* keep looking for snap */ | |
757 | break; | |
758 | } | |
759 | ||
760 | if (!clear_page_dirty_for_io(page)) { | |
761 | dout("%p !clear_page_dirty_for_io\n", page); | |
762 | unlock_page(page); | |
763 | break; | |
764 | } | |
765 | ||
766 | /* ok */ | |
767 | if (locked_pages == 0) { | |
768 | /* prepare async write request */ | |
769 | offset = page->index << PAGE_CACHE_SHIFT; | |
770 | len = wsize; | |
771 | req = ceph_osdc_new_request(&client->osdc, | |
772 | &ci->i_layout, | |
773 | ceph_vino(inode), | |
774 | offset, &len, | |
775 | CEPH_OSD_OP_WRITE, | |
776 | CEPH_OSD_FLAG_WRITE | | |
777 | CEPH_OSD_FLAG_ONDISK, | |
778 | snapc, do_sync, | |
779 | ci->i_truncate_seq, | |
780 | ci->i_truncate_size, | |
781 | &inode->i_mtime, true, 1); | |
782 | max_pages = req->r_num_pages; | |
783 | ||
784 | alloc_page_vec(client, req); | |
785 | req->r_callback = writepages_finish; | |
786 | req->r_inode = inode; | |
1d3576fd SW |
787 | } |
788 | ||
789 | /* note position of first page in pvec */ | |
790 | if (first < 0) | |
791 | first = i; | |
792 | dout("%p will write page %p idx %lu\n", | |
793 | inode, page, page->index); | |
2baba250 | 794 | |
213c99ee SW |
795 | writeback_stat = |
796 | atomic_long_inc_return(&client->writeback_count); | |
797 | if (writeback_stat > CONGESTION_ON_THRESH( | |
798 | client->mount_args->congestion_kb)) { | |
799 | set_bdi_congested(&client->backing_dev_info, | |
800 | BLK_RW_ASYNC); | |
2baba250 YS |
801 | } |
802 | ||
1d3576fd SW |
803 | set_page_writeback(page); |
804 | req->r_pages[locked_pages] = page; | |
805 | locked_pages++; | |
806 | next = page->index + 1; | |
807 | } | |
808 | ||
809 | /* did we get anything? */ | |
810 | if (!locked_pages) | |
811 | goto release_pvec_pages; | |
812 | if (i) { | |
813 | int j; | |
814 | BUG_ON(!locked_pages || first < 0); | |
815 | ||
816 | if (pvec_pages && i == pvec_pages && | |
817 | locked_pages < max_pages) { | |
818 | dout("reached end pvec, trying for more\n"); | |
819 | pagevec_reinit(&pvec); | |
820 | goto get_more_pages; | |
821 | } | |
822 | ||
823 | /* shift unused pages over in the pvec... we | |
824 | * will need to release them below. */ | |
825 | for (j = i; j < pvec_pages; j++) { | |
826 | dout(" pvec leftover page %p\n", | |
827 | pvec.pages[j]); | |
828 | pvec.pages[j-i+first] = pvec.pages[j]; | |
829 | } | |
830 | pvec.nr -= i-first; | |
831 | } | |
832 | ||
833 | /* submit the write */ | |
834 | offset = req->r_pages[0]->index << PAGE_CACHE_SHIFT; | |
835 | len = min((snap_size ? snap_size : i_size_read(inode)) - offset, | |
836 | (u64)locked_pages << PAGE_CACHE_SHIFT); | |
837 | dout("writepages got %d pages at %llu~%llu\n", | |
838 | locked_pages, offset, len); | |
839 | ||
840 | /* revise final length, page count */ | |
841 | req->r_num_pages = locked_pages; | |
842 | reqhead = req->r_request->front.iov_base; | |
843 | op = (void *)(reqhead + 1); | |
844 | op->extent.length = cpu_to_le64(len); | |
845 | op->payload_len = cpu_to_le32(len); | |
846 | req->r_request->hdr.data_len = cpu_to_le32(len); | |
847 | ||
848 | ceph_osdc_start_request(&client->osdc, req, true); | |
849 | req = NULL; | |
850 | ||
851 | /* continue? */ | |
852 | index = next; | |
853 | wbc->nr_to_write -= locked_pages; | |
854 | if (wbc->nr_to_write <= 0) | |
855 | done = 1; | |
856 | ||
857 | release_pvec_pages: | |
858 | dout("pagevec_release on %d pages (%p)\n", (int)pvec.nr, | |
859 | pvec.nr ? pvec.pages[0] : NULL); | |
860 | pagevec_release(&pvec); | |
861 | ||
862 | if (locked_pages && !done) | |
863 | goto retry; | |
864 | } | |
865 | ||
866 | if (should_loop && !done) { | |
867 | /* more to do; loop back to beginning of file */ | |
868 | dout("writepages looping back to beginning of file\n"); | |
869 | should_loop = 0; | |
870 | index = 0; | |
871 | goto retry; | |
872 | } | |
873 | ||
874 | if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0)) | |
875 | mapping->writeback_index = index; | |
876 | ||
877 | out: | |
878 | if (req) | |
879 | ceph_osdc_put_request(req); | |
880 | if (rc > 0) | |
881 | rc = 0; /* vfs expects us to return 0 */ | |
882 | ceph_put_snap_context(snapc); | |
883 | dout("writepages done, rc = %d\n", rc); | |
884 | out_final: | |
885 | return rc; | |
886 | } | |
887 | ||
888 | ||
889 | ||
890 | /* | |
891 | * See if a given @snapc is either writeable, or already written. | |
892 | */ | |
893 | static int context_is_writeable_or_written(struct inode *inode, | |
894 | struct ceph_snap_context *snapc) | |
895 | { | |
896 | struct ceph_snap_context *oldest = get_oldest_context(inode, NULL); | |
6298a337 SW |
897 | int ret = !oldest || snapc->seq <= oldest->seq; |
898 | ||
899 | ceph_put_snap_context(oldest); | |
900 | return ret; | |
1d3576fd SW |
901 | } |
902 | ||
903 | /* | |
904 | * We are only allowed to write into/dirty the page if the page is | |
905 | * clean, or already dirty within the same snap context. | |
8f883c24 SW |
906 | * |
907 | * called with page locked. | |
908 | * return success with page locked, | |
909 | * or any failure (incl -EAGAIN) with page unlocked. | |
1d3576fd | 910 | */ |
4af6b225 YS |
911 | static int ceph_update_writeable_page(struct file *file, |
912 | loff_t pos, unsigned len, | |
913 | struct page *page) | |
1d3576fd SW |
914 | { |
915 | struct inode *inode = file->f_dentry->d_inode; | |
916 | struct ceph_inode_info *ci = ceph_inode(inode); | |
917 | struct ceph_mds_client *mdsc = &ceph_inode_to_client(inode)->mdsc; | |
1d3576fd SW |
918 | loff_t page_off = pos & PAGE_CACHE_MASK; |
919 | int pos_in_page = pos & ~PAGE_CACHE_MASK; | |
920 | int end_in_page = pos_in_page + len; | |
921 | loff_t i_size; | |
1d3576fd | 922 | int r; |
80e755fe | 923 | struct ceph_snap_context *snapc, *oldest; |
1d3576fd | 924 | |
1d3576fd SW |
925 | retry_locked: |
926 | /* writepages currently holds page lock, but if we change that later, */ | |
927 | wait_on_page_writeback(page); | |
928 | ||
929 | /* check snap context */ | |
930 | BUG_ON(!ci->i_snap_realm); | |
931 | down_read(&mdsc->snap_rwsem); | |
932 | BUG_ON(!ci->i_snap_realm->cached_context); | |
80e755fe SW |
933 | snapc = (void *)page->private; |
934 | if (snapc && snapc != ci->i_head_snapc) { | |
1d3576fd SW |
935 | /* |
936 | * this page is already dirty in another (older) snap | |
937 | * context! is it writeable now? | |
938 | */ | |
80e755fe | 939 | oldest = get_oldest_context(inode, NULL); |
1d3576fd SW |
940 | up_read(&mdsc->snap_rwsem); |
941 | ||
80e755fe | 942 | if (snapc->seq > oldest->seq) { |
6298a337 | 943 | ceph_put_snap_context(oldest); |
1d3576fd | 944 | dout(" page %p snapc %p not current or oldest\n", |
6298a337 | 945 | page, snapc); |
1d3576fd SW |
946 | /* |
947 | * queue for writeback, and wait for snapc to | |
948 | * be writeable or written | |
949 | */ | |
6298a337 | 950 | snapc = ceph_get_snap_context(snapc); |
1d3576fd | 951 | unlock_page(page); |
3c6f6b79 | 952 | ceph_queue_writeback(inode); |
8f883c24 | 953 | r = wait_event_interruptible(ci->i_cap_wq, |
1d3576fd SW |
954 | context_is_writeable_or_written(inode, snapc)); |
955 | ceph_put_snap_context(snapc); | |
8f883c24 SW |
956 | if (r == -ERESTARTSYS) |
957 | return r; | |
4af6b225 | 958 | return -EAGAIN; |
1d3576fd | 959 | } |
6298a337 | 960 | ceph_put_snap_context(oldest); |
1d3576fd SW |
961 | |
962 | /* yay, writeable, do it now (without dropping page lock) */ | |
963 | dout(" page %p snapc %p not current, but oldest\n", | |
964 | page, snapc); | |
965 | if (!clear_page_dirty_for_io(page)) | |
966 | goto retry_locked; | |
967 | r = writepage_nounlock(page, NULL); | |
968 | if (r < 0) | |
969 | goto fail_nosnap; | |
970 | goto retry_locked; | |
971 | } | |
972 | ||
973 | if (PageUptodate(page)) { | |
974 | dout(" page %p already uptodate\n", page); | |
975 | return 0; | |
976 | } | |
977 | ||
978 | /* full page? */ | |
979 | if (pos_in_page == 0 && len == PAGE_CACHE_SIZE) | |
980 | return 0; | |
981 | ||
982 | /* past end of file? */ | |
983 | i_size = inode->i_size; /* caller holds i_mutex */ | |
984 | ||
985 | if (i_size + len > inode->i_sb->s_maxbytes) { | |
986 | /* file is too big */ | |
987 | r = -EINVAL; | |
988 | goto fail; | |
989 | } | |
990 | ||
991 | if (page_off >= i_size || | |
992 | (pos_in_page == 0 && (pos+len) >= i_size && | |
993 | end_in_page - pos_in_page != PAGE_CACHE_SIZE)) { | |
994 | dout(" zeroing %p 0 - %d and %d - %d\n", | |
995 | page, pos_in_page, end_in_page, (int)PAGE_CACHE_SIZE); | |
996 | zero_user_segments(page, | |
997 | 0, pos_in_page, | |
998 | end_in_page, PAGE_CACHE_SIZE); | |
999 | return 0; | |
1000 | } | |
1001 | ||
1002 | /* we need to read it. */ | |
1003 | up_read(&mdsc->snap_rwsem); | |
1004 | r = readpage_nounlock(file, page); | |
1005 | if (r < 0) | |
1006 | goto fail_nosnap; | |
1007 | goto retry_locked; | |
1008 | ||
1009 | fail: | |
1010 | up_read(&mdsc->snap_rwsem); | |
1011 | fail_nosnap: | |
1012 | unlock_page(page); | |
1013 | return r; | |
1014 | } | |
1015 | ||
4af6b225 YS |
1016 | /* |
1017 | * We are only allowed to write into/dirty the page if the page is | |
1018 | * clean, or already dirty within the same snap context. | |
1019 | */ | |
1020 | static int ceph_write_begin(struct file *file, struct address_space *mapping, | |
1021 | loff_t pos, unsigned len, unsigned flags, | |
1022 | struct page **pagep, void **fsdata) | |
1023 | { | |
1024 | struct inode *inode = file->f_dentry->d_inode; | |
1025 | struct page *page; | |
1026 | pgoff_t index = pos >> PAGE_CACHE_SHIFT; | |
1027 | int r; | |
1028 | ||
1029 | do { | |
8f883c24 | 1030 | /* get a page */ |
4af6b225 YS |
1031 | page = grab_cache_page_write_begin(mapping, index, 0); |
1032 | if (!page) | |
1033 | return -ENOMEM; | |
1034 | *pagep = page; | |
1035 | ||
1036 | dout("write_begin file %p inode %p page %p %d~%d\n", file, | |
213c99ee | 1037 | inode, page, (int)pos, (int)len); |
4af6b225 YS |
1038 | |
1039 | r = ceph_update_writeable_page(file, pos, len, page); | |
1040 | } while (r == -EAGAIN); | |
1041 | ||
1042 | return r; | |
1043 | } | |
1044 | ||
1d3576fd SW |
1045 | /* |
1046 | * we don't do anything in here that simple_write_end doesn't do | |
1047 | * except adjust dirty page accounting and drop read lock on | |
1048 | * mdsc->snap_rwsem. | |
1049 | */ | |
1050 | static int ceph_write_end(struct file *file, struct address_space *mapping, | |
1051 | loff_t pos, unsigned len, unsigned copied, | |
1052 | struct page *page, void *fsdata) | |
1053 | { | |
1054 | struct inode *inode = file->f_dentry->d_inode; | |
2baba250 YS |
1055 | struct ceph_client *client = ceph_inode_to_client(inode); |
1056 | struct ceph_mds_client *mdsc = &client->mdsc; | |
1d3576fd SW |
1057 | unsigned from = pos & (PAGE_CACHE_SIZE - 1); |
1058 | int check_cap = 0; | |
1059 | ||
1060 | dout("write_end file %p inode %p page %p %d~%d (%d)\n", file, | |
1061 | inode, page, (int)pos, (int)copied, (int)len); | |
1062 | ||
1063 | /* zero the stale part of the page if we did a short copy */ | |
1064 | if (copied < len) | |
1065 | zero_user_segment(page, from+copied, len); | |
1066 | ||
1067 | /* did file size increase? */ | |
1068 | /* (no need for i_size_read(); we caller holds i_mutex */ | |
1069 | if (pos+copied > inode->i_size) | |
1070 | check_cap = ceph_inode_set_size(inode, pos+copied); | |
1071 | ||
1072 | if (!PageUptodate(page)) | |
1073 | SetPageUptodate(page); | |
1074 | ||
1075 | set_page_dirty(page); | |
1076 | ||
1077 | unlock_page(page); | |
1078 | up_read(&mdsc->snap_rwsem); | |
1079 | page_cache_release(page); | |
1080 | ||
1081 | if (check_cap) | |
1082 | ceph_check_caps(ceph_inode(inode), CHECK_CAPS_AUTHONLY, NULL); | |
1083 | ||
1084 | return copied; | |
1085 | } | |
1086 | ||
1087 | /* | |
1088 | * we set .direct_IO to indicate direct io is supported, but since we | |
1089 | * intercept O_DIRECT reads and writes early, this function should | |
1090 | * never get called. | |
1091 | */ | |
1092 | static ssize_t ceph_direct_io(int rw, struct kiocb *iocb, | |
1093 | const struct iovec *iov, | |
1094 | loff_t pos, unsigned long nr_segs) | |
1095 | { | |
1096 | WARN_ON(1); | |
1097 | return -EINVAL; | |
1098 | } | |
1099 | ||
1100 | const struct address_space_operations ceph_aops = { | |
1101 | .readpage = ceph_readpage, | |
1102 | .readpages = ceph_readpages, | |
1103 | .writepage = ceph_writepage, | |
1104 | .writepages = ceph_writepages_start, | |
1105 | .write_begin = ceph_write_begin, | |
1106 | .write_end = ceph_write_end, | |
1107 | .set_page_dirty = ceph_set_page_dirty, | |
1108 | .invalidatepage = ceph_invalidatepage, | |
1109 | .releasepage = ceph_releasepage, | |
1110 | .direct_IO = ceph_direct_io, | |
1111 | }; | |
1112 | ||
1113 | ||
1114 | /* | |
1115 | * vm ops | |
1116 | */ | |
1117 | ||
1118 | /* | |
1119 | * Reuse write_begin here for simplicity. | |
1120 | */ | |
1121 | static int ceph_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) | |
1122 | { | |
1123 | struct inode *inode = vma->vm_file->f_dentry->d_inode; | |
1124 | struct page *page = vmf->page; | |
1125 | struct ceph_mds_client *mdsc = &ceph_inode_to_client(inode)->mdsc; | |
1126 | loff_t off = page->index << PAGE_CACHE_SHIFT; | |
1127 | loff_t size, len; | |
1d3576fd SW |
1128 | int ret; |
1129 | ||
1130 | size = i_size_read(inode); | |
1131 | if (off + PAGE_CACHE_SIZE <= size) | |
1132 | len = PAGE_CACHE_SIZE; | |
1133 | else | |
1134 | len = size & ~PAGE_CACHE_MASK; | |
1135 | ||
1136 | dout("page_mkwrite %p %llu~%llu page %p idx %lu\n", inode, | |
1137 | off, len, page, page->index); | |
4af6b225 YS |
1138 | |
1139 | lock_page(page); | |
1140 | ||
1141 | ret = VM_FAULT_NOPAGE; | |
1142 | if ((off > size) || | |
1143 | (page->mapping != inode->i_mapping)) | |
1144 | goto out; | |
1145 | ||
1146 | ret = ceph_update_writeable_page(vma->vm_file, off, len, page); | |
1147 | if (ret == 0) { | |
1148 | /* success. we'll keep the page locked. */ | |
1d3576fd SW |
1149 | set_page_dirty(page); |
1150 | up_read(&mdsc->snap_rwsem); | |
1d3576fd SW |
1151 | ret = VM_FAULT_LOCKED; |
1152 | } else { | |
4af6b225 YS |
1153 | if (ret == -ENOMEM) |
1154 | ret = VM_FAULT_OOM; | |
1155 | else | |
1156 | ret = VM_FAULT_SIGBUS; | |
1d3576fd | 1157 | } |
4af6b225 | 1158 | out: |
1d3576fd | 1159 | dout("page_mkwrite %p %llu~%llu = %d\n", inode, off, len, ret); |
4af6b225 YS |
1160 | if (ret != VM_FAULT_LOCKED) |
1161 | unlock_page(page); | |
1d3576fd SW |
1162 | return ret; |
1163 | } | |
1164 | ||
1165 | static struct vm_operations_struct ceph_vmops = { | |
1166 | .fault = filemap_fault, | |
1167 | .page_mkwrite = ceph_page_mkwrite, | |
1168 | }; | |
1169 | ||
1170 | int ceph_mmap(struct file *file, struct vm_area_struct *vma) | |
1171 | { | |
1172 | struct address_space *mapping = file->f_mapping; | |
1173 | ||
1174 | if (!mapping->a_ops->readpage) | |
1175 | return -ENOEXEC; | |
1176 | file_accessed(file); | |
1177 | vma->vm_ops = &ceph_vmops; | |
1178 | vma->vm_flags |= VM_CAN_NONLINEAR; | |
1179 | return 0; | |
1180 | } |