Commit | Line | Data |
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3d14c5d2 | 1 | #include <linux/ceph/ceph_debug.h> |
1d3576fd SW |
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" | |
3d14c5d2 YS |
13 | #include "mds_client.h" |
14 | #include <linux/ceph/osd_client.h> | |
1d3576fd SW |
15 | |
16 | /* | |
17 | * Ceph address space ops. | |
18 | * | |
19 | * There are a few funny things going on here. | |
20 | * | |
21 | * The page->private field is used to reference a struct | |
22 | * ceph_snap_context for _every_ dirty page. This indicates which | |
23 | * snapshot the page was logically dirtied in, and thus which snap | |
24 | * context needs to be associated with the osd write during writeback. | |
25 | * | |
26 | * Similarly, struct ceph_inode_info maintains a set of counters to | |
25985edc | 27 | * count dirty pages on the inode. In the absence of snapshots, |
1d3576fd SW |
28 | * i_wrbuffer_ref == i_wrbuffer_ref_head == the dirty page count. |
29 | * | |
30 | * When a snapshot is taken (that is, when the client receives | |
31 | * notification that a snapshot was taken), each inode with caps and | |
32 | * with dirty pages (dirty pages implies there is a cap) gets a new | |
33 | * ceph_cap_snap in the i_cap_snaps list (which is sorted in ascending | |
34 | * order, new snaps go to the tail). The i_wrbuffer_ref_head count is | |
35 | * moved to capsnap->dirty. (Unless a sync write is currently in | |
36 | * progress. In that case, the capsnap is said to be "pending", new | |
37 | * writes cannot start, and the capsnap isn't "finalized" until the | |
38 | * write completes (or fails) and a final size/mtime for the inode for | |
39 | * that snap can be settled upon.) i_wrbuffer_ref_head is reset to 0. | |
40 | * | |
41 | * On writeback, we must submit writes to the osd IN SNAP ORDER. So, | |
42 | * we look for the first capsnap in i_cap_snaps and write out pages in | |
43 | * that snap context _only_. Then we move on to the next capsnap, | |
44 | * eventually reaching the "live" or "head" context (i.e., pages that | |
45 | * are not yet snapped) and are writing the most recently dirtied | |
46 | * pages. | |
47 | * | |
48 | * Invalidate and so forth must take care to ensure the dirty page | |
49 | * accounting is preserved. | |
50 | */ | |
51 | ||
2baba250 YS |
52 | #define CONGESTION_ON_THRESH(congestion_kb) (congestion_kb >> (PAGE_SHIFT-10)) |
53 | #define CONGESTION_OFF_THRESH(congestion_kb) \ | |
54 | (CONGESTION_ON_THRESH(congestion_kb) - \ | |
55 | (CONGESTION_ON_THRESH(congestion_kb) >> 2)) | |
56 | ||
57 | ||
1d3576fd SW |
58 | |
59 | /* | |
60 | * Dirty a page. Optimistically adjust accounting, on the assumption | |
61 | * that we won't race with invalidate. If we do, readjust. | |
62 | */ | |
63 | static int ceph_set_page_dirty(struct page *page) | |
64 | { | |
65 | struct address_space *mapping = page->mapping; | |
66 | struct inode *inode; | |
67 | struct ceph_inode_info *ci; | |
68 | int undo = 0; | |
69 | struct ceph_snap_context *snapc; | |
70 | ||
71 | if (unlikely(!mapping)) | |
72 | return !TestSetPageDirty(page); | |
73 | ||
74 | if (TestSetPageDirty(page)) { | |
75 | dout("%p set_page_dirty %p idx %lu -- already dirty\n", | |
76 | mapping->host, page, page->index); | |
77 | return 0; | |
78 | } | |
79 | ||
80 | inode = mapping->host; | |
81 | ci = ceph_inode(inode); | |
82 | ||
83 | /* | |
84 | * Note that we're grabbing a snapc ref here without holding | |
85 | * any locks! | |
86 | */ | |
87 | snapc = ceph_get_snap_context(ci->i_snap_realm->cached_context); | |
88 | ||
89 | /* dirty the head */ | |
90 | spin_lock(&inode->i_lock); | |
7d8cb26d | 91 | if (ci->i_head_snapc == NULL) |
1d3576fd SW |
92 | ci->i_head_snapc = ceph_get_snap_context(snapc); |
93 | ++ci->i_wrbuffer_ref_head; | |
94 | if (ci->i_wrbuffer_ref == 0) | |
0444d76a | 95 | ihold(inode); |
1d3576fd SW |
96 | ++ci->i_wrbuffer_ref; |
97 | dout("%p set_page_dirty %p idx %lu head %d/%d -> %d/%d " | |
98 | "snapc %p seq %lld (%d snaps)\n", | |
99 | mapping->host, page, page->index, | |
100 | ci->i_wrbuffer_ref-1, ci->i_wrbuffer_ref_head-1, | |
101 | ci->i_wrbuffer_ref, ci->i_wrbuffer_ref_head, | |
102 | snapc, snapc->seq, snapc->num_snaps); | |
103 | spin_unlock(&inode->i_lock); | |
104 | ||
105 | /* now adjust page */ | |
106 | spin_lock_irq(&mapping->tree_lock); | |
107 | if (page->mapping) { /* Race with truncate? */ | |
108 | WARN_ON_ONCE(!PageUptodate(page)); | |
679ceace | 109 | account_page_dirtied(page, page->mapping); |
1d3576fd SW |
110 | radix_tree_tag_set(&mapping->page_tree, |
111 | page_index(page), PAGECACHE_TAG_DIRTY); | |
112 | ||
113 | /* | |
114 | * Reference snap context in page->private. Also set | |
115 | * PagePrivate so that we get invalidatepage callback. | |
116 | */ | |
117 | page->private = (unsigned long)snapc; | |
118 | SetPagePrivate(page); | |
119 | } else { | |
120 | dout("ANON set_page_dirty %p (raced truncate?)\n", page); | |
121 | undo = 1; | |
122 | } | |
123 | ||
124 | spin_unlock_irq(&mapping->tree_lock); | |
125 | ||
126 | if (undo) | |
127 | /* whoops, we failed to dirty the page */ | |
128 | ceph_put_wrbuffer_cap_refs(ci, 1, snapc); | |
129 | ||
130 | __mark_inode_dirty(mapping->host, I_DIRTY_PAGES); | |
131 | ||
132 | BUG_ON(!PageDirty(page)); | |
133 | return 1; | |
134 | } | |
135 | ||
136 | /* | |
137 | * If we are truncating the full page (i.e. offset == 0), adjust the | |
138 | * dirty page counters appropriately. Only called if there is private | |
139 | * data on the page. | |
140 | */ | |
141 | static void ceph_invalidatepage(struct page *page, unsigned long offset) | |
142 | { | |
4ce1e9ad | 143 | struct inode *inode; |
1d3576fd SW |
144 | struct ceph_inode_info *ci; |
145 | struct ceph_snap_context *snapc = (void *)page->private; | |
146 | ||
147 | BUG_ON(!PageLocked(page)); | |
148 | BUG_ON(!page->private); | |
149 | BUG_ON(!PagePrivate(page)); | |
150 | BUG_ON(!page->mapping); | |
151 | ||
4ce1e9ad AB |
152 | inode = page->mapping->host; |
153 | ||
1d3576fd SW |
154 | /* |
155 | * We can get non-dirty pages here due to races between | |
156 | * set_page_dirty and truncate_complete_page; just spit out a | |
157 | * warning, in case we end up with accounting problems later. | |
158 | */ | |
159 | if (!PageDirty(page)) | |
160 | pr_err("%p invalidatepage %p page not dirty\n", inode, page); | |
161 | ||
162 | if (offset == 0) | |
163 | ClearPageChecked(page); | |
164 | ||
165 | ci = ceph_inode(inode); | |
166 | if (offset == 0) { | |
167 | dout("%p invalidatepage %p idx %lu full dirty page %lu\n", | |
168 | inode, page, page->index, offset); | |
169 | ceph_put_wrbuffer_cap_refs(ci, 1, snapc); | |
170 | ceph_put_snap_context(snapc); | |
171 | page->private = 0; | |
172 | ClearPagePrivate(page); | |
173 | } else { | |
174 | dout("%p invalidatepage %p idx %lu partial dirty page\n", | |
175 | inode, page, page->index); | |
176 | } | |
177 | } | |
178 | ||
179 | /* just a sanity check */ | |
180 | static int ceph_releasepage(struct page *page, gfp_t g) | |
181 | { | |
182 | struct inode *inode = page->mapping ? page->mapping->host : NULL; | |
183 | dout("%p releasepage %p idx %lu\n", inode, page, page->index); | |
184 | WARN_ON(PageDirty(page)); | |
185 | WARN_ON(page->private); | |
186 | WARN_ON(PagePrivate(page)); | |
187 | return 0; | |
188 | } | |
189 | ||
190 | /* | |
191 | * read a single page, without unlocking it. | |
192 | */ | |
193 | static int readpage_nounlock(struct file *filp, struct page *page) | |
194 | { | |
195 | struct inode *inode = filp->f_dentry->d_inode; | |
196 | struct ceph_inode_info *ci = ceph_inode(inode); | |
3d14c5d2 YS |
197 | struct ceph_osd_client *osdc = |
198 | &ceph_inode_to_client(inode)->client->osdc; | |
1d3576fd SW |
199 | int err = 0; |
200 | u64 len = PAGE_CACHE_SIZE; | |
201 | ||
202 | dout("readpage inode %p file %p page %p index %lu\n", | |
203 | inode, filp, page, page->index); | |
204 | err = ceph_osdc_readpages(osdc, ceph_vino(inode), &ci->i_layout, | |
205 | page->index << PAGE_CACHE_SHIFT, &len, | |
206 | ci->i_truncate_seq, ci->i_truncate_size, | |
b7495fc2 | 207 | &page, 1, 0); |
1d3576fd SW |
208 | if (err == -ENOENT) |
209 | err = 0; | |
210 | if (err < 0) { | |
211 | SetPageError(page); | |
212 | goto out; | |
213 | } else if (err < PAGE_CACHE_SIZE) { | |
214 | /* zero fill remainder of page */ | |
215 | zero_user_segment(page, err, PAGE_CACHE_SIZE); | |
216 | } | |
217 | SetPageUptodate(page); | |
218 | ||
219 | out: | |
220 | return err < 0 ? err : 0; | |
221 | } | |
222 | ||
223 | static int ceph_readpage(struct file *filp, struct page *page) | |
224 | { | |
225 | int r = readpage_nounlock(filp, page); | |
226 | unlock_page(page); | |
227 | return r; | |
228 | } | |
229 | ||
230 | /* | |
7c272194 | 231 | * Finish an async read(ahead) op. |
1d3576fd | 232 | */ |
7c272194 | 233 | static void finish_read(struct ceph_osd_request *req, struct ceph_msg *msg) |
1d3576fd | 234 | { |
7c272194 SW |
235 | struct inode *inode = req->r_inode; |
236 | struct ceph_osd_reply_head *replyhead; | |
237 | int rc, bytes; | |
238 | int i; | |
1d3576fd | 239 | |
7c272194 SW |
240 | /* parse reply */ |
241 | replyhead = msg->front.iov_base; | |
242 | WARN_ON(le32_to_cpu(replyhead->num_ops) == 0); | |
243 | rc = le32_to_cpu(replyhead->result); | |
244 | bytes = le32_to_cpu(msg->hdr.data_len); | |
1d3576fd | 245 | |
7c272194 SW |
246 | dout("finish_read %p req %p rc %d bytes %d\n", inode, req, rc, bytes); |
247 | ||
248 | /* unlock all pages, zeroing any data we didn't read */ | |
249 | for (i = 0; i < req->r_num_pages; i++, bytes -= PAGE_CACHE_SIZE) { | |
250 | struct page *page = req->r_pages[i]; | |
251 | ||
252 | if (bytes < (int)PAGE_CACHE_SIZE) { | |
253 | /* zero (remainder of) page */ | |
254 | int s = bytes < 0 ? 0 : bytes; | |
255 | zero_user_segment(page, s, PAGE_CACHE_SIZE); | |
1d3576fd | 256 | } |
7c272194 SW |
257 | dout("finish_read %p uptodate %p idx %lu\n", inode, page, |
258 | page->index); | |
259 | flush_dcache_page(page); | |
260 | SetPageUptodate(page); | |
261 | unlock_page(page); | |
262 | page_cache_release(page); | |
1d3576fd | 263 | } |
7c272194 | 264 | kfree(req->r_pages); |
1d3576fd SW |
265 | } |
266 | ||
267 | /* | |
7c272194 SW |
268 | * start an async read(ahead) operation. return nr_pages we submitted |
269 | * a read for on success, or negative error code. | |
1d3576fd | 270 | */ |
0d66a487 | 271 | static int start_read(struct inode *inode, struct list_head *page_list, int max) |
1d3576fd | 272 | { |
3d14c5d2 YS |
273 | struct ceph_osd_client *osdc = |
274 | &ceph_inode_to_client(inode)->client->osdc; | |
7c272194 SW |
275 | struct ceph_inode_info *ci = ceph_inode(inode); |
276 | struct page *page = list_entry(page_list->prev, struct page, lru); | |
277 | struct ceph_osd_request *req; | |
278 | u64 off; | |
1d3576fd | 279 | u64 len; |
7c272194 SW |
280 | int i; |
281 | struct page **pages; | |
282 | pgoff_t next_index; | |
283 | int nr_pages = 0; | |
284 | int ret; | |
1d3576fd | 285 | |
7c272194 | 286 | off = page->index << PAGE_CACHE_SHIFT; |
1d3576fd | 287 | |
7c272194 SW |
288 | /* count pages */ |
289 | next_index = page->index; | |
290 | list_for_each_entry_reverse(page, page_list, lru) { | |
291 | if (page->index != next_index) | |
292 | break; | |
293 | nr_pages++; | |
294 | next_index++; | |
0d66a487 SW |
295 | if (max && nr_pages == max) |
296 | break; | |
7c272194 | 297 | } |
1d3576fd | 298 | len = nr_pages << PAGE_CACHE_SHIFT; |
7c272194 SW |
299 | dout("start_read %p nr_pages %d is %lld~%lld\n", inode, nr_pages, |
300 | off, len); | |
301 | ||
302 | req = ceph_osdc_new_request(osdc, &ci->i_layout, ceph_vino(inode), | |
303 | off, &len, | |
304 | CEPH_OSD_OP_READ, CEPH_OSD_FLAG_READ, | |
305 | NULL, 0, | |
306 | ci->i_truncate_seq, ci->i_truncate_size, | |
307 | NULL, false, 1, 0); | |
308 | if (!req) | |
309 | return -ENOMEM; | |
1d3576fd | 310 | |
7c272194 SW |
311 | /* build page vector */ |
312 | nr_pages = len >> PAGE_CACHE_SHIFT; | |
313 | pages = kmalloc(sizeof(*pages) * nr_pages, GFP_NOFS); | |
314 | ret = -ENOMEM; | |
315 | if (!pages) | |
316 | goto out; | |
317 | for (i = 0; i < nr_pages; ++i) { | |
318 | page = list_entry(page_list->prev, struct page, lru); | |
319 | BUG_ON(PageLocked(page)); | |
1d3576fd | 320 | list_del(&page->lru); |
7c272194 SW |
321 | |
322 | dout("start_read %p adding %p idx %lu\n", inode, page, | |
323 | page->index); | |
324 | if (add_to_page_cache_lru(page, &inode->i_data, page->index, | |
213c99ee | 325 | GFP_NOFS)) { |
1d3576fd | 326 | page_cache_release(page); |
7c272194 | 327 | dout("start_read %p add_to_page_cache failed %p\n", |
1d3576fd | 328 | inode, page); |
7c272194 SW |
329 | nr_pages = i; |
330 | goto out_pages; | |
1d3576fd | 331 | } |
7c272194 | 332 | pages[i] = page; |
1d3576fd | 333 | } |
7c272194 SW |
334 | req->r_pages = pages; |
335 | req->r_num_pages = nr_pages; | |
336 | req->r_callback = finish_read; | |
337 | req->r_inode = inode; | |
338 | ||
339 | dout("start_read %p starting %p %lld~%lld\n", inode, req, off, len); | |
340 | ret = ceph_osdc_start_request(osdc, req, false); | |
341 | if (ret < 0) | |
342 | goto out_pages; | |
343 | ceph_osdc_put_request(req); | |
344 | return nr_pages; | |
345 | ||
346 | out_pages: | |
347 | ceph_release_page_vector(pages, nr_pages); | |
7c272194 SW |
348 | out: |
349 | ceph_osdc_put_request(req); | |
350 | return ret; | |
351 | } | |
1d3576fd | 352 | |
7c272194 SW |
353 | |
354 | /* | |
355 | * Read multiple pages. Leave pages we don't read + unlock in page_list; | |
356 | * the caller (VM) cleans them up. | |
357 | */ | |
358 | static int ceph_readpages(struct file *file, struct address_space *mapping, | |
359 | struct list_head *page_list, unsigned nr_pages) | |
360 | { | |
361 | struct inode *inode = file->f_dentry->d_inode; | |
0d66a487 | 362 | struct ceph_fs_client *fsc = ceph_inode_to_client(inode); |
7c272194 | 363 | int rc = 0; |
0d66a487 SW |
364 | int max = 0; |
365 | ||
366 | if (fsc->mount_options->rsize >= PAGE_CACHE_SIZE) | |
367 | max = (fsc->mount_options->rsize + PAGE_CACHE_SIZE - 1) | |
368 | >> PAGE_SHIFT; | |
7c272194 | 369 | |
0d66a487 SW |
370 | dout("readpages %p file %p nr_pages %d max %d\n", inode, file, nr_pages, |
371 | max); | |
7c272194 | 372 | while (!list_empty(page_list)) { |
0d66a487 | 373 | rc = start_read(inode, page_list, max); |
7c272194 SW |
374 | if (rc < 0) |
375 | goto out; | |
376 | BUG_ON(rc == 0); | |
377 | } | |
1d3576fd | 378 | out: |
7c272194 | 379 | dout("readpages %p file %p ret %d\n", inode, file, rc); |
1d3576fd SW |
380 | return rc; |
381 | } | |
382 | ||
383 | /* | |
384 | * Get ref for the oldest snapc for an inode with dirty data... that is, the | |
385 | * only snap context we are allowed to write back. | |
1d3576fd | 386 | */ |
6298a337 SW |
387 | static struct ceph_snap_context *get_oldest_context(struct inode *inode, |
388 | u64 *snap_size) | |
1d3576fd SW |
389 | { |
390 | struct ceph_inode_info *ci = ceph_inode(inode); | |
391 | struct ceph_snap_context *snapc = NULL; | |
392 | struct ceph_cap_snap *capsnap = NULL; | |
393 | ||
6298a337 | 394 | spin_lock(&inode->i_lock); |
1d3576fd SW |
395 | list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) { |
396 | dout(" cap_snap %p snapc %p has %d dirty pages\n", capsnap, | |
397 | capsnap->context, capsnap->dirty_pages); | |
398 | if (capsnap->dirty_pages) { | |
399 | snapc = ceph_get_snap_context(capsnap->context); | |
400 | if (snap_size) | |
401 | *snap_size = capsnap->size; | |
402 | break; | |
403 | } | |
404 | } | |
7d8cb26d | 405 | if (!snapc && ci->i_wrbuffer_ref_head) { |
80e755fe | 406 | snapc = ceph_get_snap_context(ci->i_head_snapc); |
1d3576fd SW |
407 | dout(" head snapc %p has %d dirty pages\n", |
408 | snapc, ci->i_wrbuffer_ref_head); | |
409 | } | |
1d3576fd SW |
410 | spin_unlock(&inode->i_lock); |
411 | return snapc; | |
412 | } | |
413 | ||
414 | /* | |
415 | * Write a single page, but leave the page locked. | |
416 | * | |
417 | * If we get a write error, set the page error bit, but still adjust the | |
418 | * dirty page accounting (i.e., page is no longer dirty). | |
419 | */ | |
420 | static int writepage_nounlock(struct page *page, struct writeback_control *wbc) | |
421 | { | |
422 | struct inode *inode; | |
423 | struct ceph_inode_info *ci; | |
3d14c5d2 | 424 | struct ceph_fs_client *fsc; |
1d3576fd SW |
425 | struct ceph_osd_client *osdc; |
426 | loff_t page_off = page->index << PAGE_CACHE_SHIFT; | |
427 | int len = PAGE_CACHE_SIZE; | |
428 | loff_t i_size; | |
429 | int err = 0; | |
6298a337 | 430 | struct ceph_snap_context *snapc, *oldest; |
1d3576fd | 431 | u64 snap_size = 0; |
2baba250 | 432 | long writeback_stat; |
1d3576fd SW |
433 | |
434 | dout("writepage %p idx %lu\n", page, page->index); | |
435 | ||
436 | if (!page->mapping || !page->mapping->host) { | |
437 | dout("writepage %p - no mapping\n", page); | |
438 | return -EFAULT; | |
439 | } | |
440 | inode = page->mapping->host; | |
441 | ci = ceph_inode(inode); | |
3d14c5d2 YS |
442 | fsc = ceph_inode_to_client(inode); |
443 | osdc = &fsc->client->osdc; | |
1d3576fd SW |
444 | |
445 | /* verify this is a writeable snap context */ | |
446 | snapc = (void *)page->private; | |
447 | if (snapc == NULL) { | |
448 | dout("writepage %p page %p not dirty?\n", inode, page); | |
449 | goto out; | |
450 | } | |
6298a337 SW |
451 | oldest = get_oldest_context(inode, &snap_size); |
452 | if (snapc->seq > oldest->seq) { | |
1d3576fd SW |
453 | dout("writepage %p page %p snapc %p not writeable - noop\n", |
454 | inode, page, (void *)page->private); | |
455 | /* we should only noop if called by kswapd */ | |
456 | WARN_ON((current->flags & PF_MEMALLOC) == 0); | |
6298a337 | 457 | ceph_put_snap_context(oldest); |
1d3576fd SW |
458 | goto out; |
459 | } | |
6298a337 | 460 | ceph_put_snap_context(oldest); |
1d3576fd SW |
461 | |
462 | /* is this a partial page at end of file? */ | |
463 | if (snap_size) | |
464 | i_size = snap_size; | |
465 | else | |
466 | i_size = i_size_read(inode); | |
467 | if (i_size < page_off + len) | |
468 | len = i_size - page_off; | |
469 | ||
ae00d4f3 SW |
470 | dout("writepage %p page %p index %lu on %llu~%u snapc %p\n", |
471 | inode, page, page->index, page_off, len, snapc); | |
1d3576fd | 472 | |
3d14c5d2 | 473 | writeback_stat = atomic_long_inc_return(&fsc->writeback_count); |
2baba250 | 474 | if (writeback_stat > |
3d14c5d2 YS |
475 | CONGESTION_ON_THRESH(fsc->mount_options->congestion_kb)) |
476 | set_bdi_congested(&fsc->backing_dev_info, BLK_RW_ASYNC); | |
2baba250 | 477 | |
1d3576fd SW |
478 | set_page_writeback(page); |
479 | err = ceph_osdc_writepages(osdc, ceph_vino(inode), | |
480 | &ci->i_layout, snapc, | |
481 | page_off, len, | |
482 | ci->i_truncate_seq, ci->i_truncate_size, | |
483 | &inode->i_mtime, | |
484 | &page, 1, 0, 0, true); | |
485 | if (err < 0) { | |
486 | dout("writepage setting page/mapping error %d %p\n", err, page); | |
487 | SetPageError(page); | |
488 | mapping_set_error(&inode->i_data, err); | |
489 | if (wbc) | |
490 | wbc->pages_skipped++; | |
491 | } else { | |
492 | dout("writepage cleaned page %p\n", page); | |
493 | err = 0; /* vfs expects us to return 0 */ | |
494 | } | |
495 | page->private = 0; | |
496 | ClearPagePrivate(page); | |
497 | end_page_writeback(page); | |
498 | ceph_put_wrbuffer_cap_refs(ci, 1, snapc); | |
6298a337 | 499 | ceph_put_snap_context(snapc); /* page's reference */ |
1d3576fd SW |
500 | out: |
501 | return err; | |
502 | } | |
503 | ||
504 | static int ceph_writepage(struct page *page, struct writeback_control *wbc) | |
505 | { | |
dbd646a8 YS |
506 | int err; |
507 | struct inode *inode = page->mapping->host; | |
508 | BUG_ON(!inode); | |
70b666c3 | 509 | ihold(inode); |
dbd646a8 | 510 | err = writepage_nounlock(page, wbc); |
1d3576fd | 511 | unlock_page(page); |
dbd646a8 | 512 | iput(inode); |
1d3576fd SW |
513 | return err; |
514 | } | |
515 | ||
516 | ||
517 | /* | |
518 | * lame release_pages helper. release_pages() isn't exported to | |
519 | * modules. | |
520 | */ | |
521 | static void ceph_release_pages(struct page **pages, int num) | |
522 | { | |
523 | struct pagevec pvec; | |
524 | int i; | |
525 | ||
526 | pagevec_init(&pvec, 0); | |
527 | for (i = 0; i < num; i++) { | |
528 | if (pagevec_add(&pvec, pages[i]) == 0) | |
529 | pagevec_release(&pvec); | |
530 | } | |
531 | pagevec_release(&pvec); | |
532 | } | |
533 | ||
534 | ||
535 | /* | |
536 | * async writeback completion handler. | |
537 | * | |
538 | * If we get an error, set the mapping error bit, but not the individual | |
539 | * page error bits. | |
540 | */ | |
541 | static void writepages_finish(struct ceph_osd_request *req, | |
542 | struct ceph_msg *msg) | |
543 | { | |
544 | struct inode *inode = req->r_inode; | |
545 | struct ceph_osd_reply_head *replyhead; | |
546 | struct ceph_osd_op *op; | |
547 | struct ceph_inode_info *ci = ceph_inode(inode); | |
548 | unsigned wrote; | |
1d3576fd SW |
549 | struct page *page; |
550 | int i; | |
551 | struct ceph_snap_context *snapc = req->r_snapc; | |
552 | struct address_space *mapping = inode->i_mapping; | |
1d3576fd SW |
553 | __s32 rc = -EIO; |
554 | u64 bytes = 0; | |
3d14c5d2 | 555 | struct ceph_fs_client *fsc = ceph_inode_to_client(inode); |
2baba250 | 556 | long writeback_stat; |
7ff899da | 557 | unsigned issued = ceph_caps_issued(ci); |
1d3576fd SW |
558 | |
559 | /* parse reply */ | |
560 | replyhead = msg->front.iov_base; | |
561 | WARN_ON(le32_to_cpu(replyhead->num_ops) == 0); | |
562 | op = (void *)(replyhead + 1); | |
563 | rc = le32_to_cpu(replyhead->result); | |
564 | bytes = le64_to_cpu(op->extent.length); | |
565 | ||
566 | if (rc >= 0) { | |
79788c69 SW |
567 | /* |
568 | * Assume we wrote the pages we originally sent. The | |
569 | * osd might reply with fewer pages if our writeback | |
570 | * raced with a truncation and was adjusted at the osd, | |
571 | * so don't believe the reply. | |
572 | */ | |
573 | wrote = req->r_num_pages; | |
1d3576fd SW |
574 | } else { |
575 | wrote = 0; | |
576 | mapping_set_error(mapping, rc); | |
577 | } | |
578 | dout("writepages_finish %p rc %d bytes %llu wrote %d (pages)\n", | |
579 | inode, rc, bytes, wrote); | |
580 | ||
581 | /* clean all pages */ | |
582 | for (i = 0; i < req->r_num_pages; i++) { | |
583 | page = req->r_pages[i]; | |
584 | BUG_ON(!page); | |
585 | WARN_ON(!PageUptodate(page)); | |
586 | ||
2baba250 | 587 | writeback_stat = |
3d14c5d2 | 588 | atomic_long_dec_return(&fsc->writeback_count); |
2baba250 | 589 | if (writeback_stat < |
3d14c5d2 YS |
590 | CONGESTION_OFF_THRESH(fsc->mount_options->congestion_kb)) |
591 | clear_bdi_congested(&fsc->backing_dev_info, | |
2baba250 YS |
592 | BLK_RW_ASYNC); |
593 | ||
80e755fe | 594 | ceph_put_snap_context((void *)page->private); |
1d3576fd SW |
595 | page->private = 0; |
596 | ClearPagePrivate(page); | |
1d3576fd SW |
597 | dout("unlocking %d %p\n", i, page); |
598 | end_page_writeback(page); | |
e63dc5c7 YS |
599 | |
600 | /* | |
601 | * We lost the cache cap, need to truncate the page before | |
602 | * it is unlocked, otherwise we'd truncate it later in the | |
603 | * page truncation thread, possibly losing some data that | |
604 | * raced its way in | |
605 | */ | |
2962507c | 606 | if ((issued & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) == 0) |
e63dc5c7 YS |
607 | generic_error_remove_page(inode->i_mapping, page); |
608 | ||
1d3576fd SW |
609 | unlock_page(page); |
610 | } | |
611 | dout("%p wrote+cleaned %d pages\n", inode, wrote); | |
612 | ceph_put_wrbuffer_cap_refs(ci, req->r_num_pages, snapc); | |
613 | ||
614 | ceph_release_pages(req->r_pages, req->r_num_pages); | |
615 | if (req->r_pages_from_pool) | |
616 | mempool_free(req->r_pages, | |
640ef79d | 617 | ceph_sb_to_client(inode->i_sb)->wb_pagevec_pool); |
1d3576fd SW |
618 | else |
619 | kfree(req->r_pages); | |
620 | ceph_osdc_put_request(req); | |
621 | } | |
622 | ||
623 | /* | |
624 | * allocate a page vec, either directly, or if necessary, via a the | |
625 | * mempool. we avoid the mempool if we can because req->r_num_pages | |
626 | * may be less than the maximum write size. | |
627 | */ | |
3d14c5d2 | 628 | static void alloc_page_vec(struct ceph_fs_client *fsc, |
1d3576fd SW |
629 | struct ceph_osd_request *req) |
630 | { | |
631 | req->r_pages = kmalloc(sizeof(struct page *) * req->r_num_pages, | |
632 | GFP_NOFS); | |
633 | if (!req->r_pages) { | |
3d14c5d2 | 634 | req->r_pages = mempool_alloc(fsc->wb_pagevec_pool, GFP_NOFS); |
1d3576fd SW |
635 | req->r_pages_from_pool = 1; |
636 | WARN_ON(!req->r_pages); | |
637 | } | |
638 | } | |
639 | ||
640 | /* | |
641 | * initiate async writeback | |
642 | */ | |
643 | static int ceph_writepages_start(struct address_space *mapping, | |
644 | struct writeback_control *wbc) | |
645 | { | |
646 | struct inode *inode = mapping->host; | |
1d3576fd | 647 | struct ceph_inode_info *ci = ceph_inode(inode); |
3d14c5d2 | 648 | struct ceph_fs_client *fsc; |
1d3576fd SW |
649 | pgoff_t index, start, end; |
650 | int range_whole = 0; | |
651 | int should_loop = 1; | |
652 | pgoff_t max_pages = 0, max_pages_ever = 0; | |
80e755fe | 653 | struct ceph_snap_context *snapc = NULL, *last_snapc = NULL, *pgsnapc; |
1d3576fd SW |
654 | struct pagevec pvec; |
655 | int done = 0; | |
656 | int rc = 0; | |
657 | unsigned wsize = 1 << inode->i_blkbits; | |
658 | struct ceph_osd_request *req = NULL; | |
659 | int do_sync; | |
660 | u64 snap_size = 0; | |
661 | ||
662 | /* | |
663 | * Include a 'sync' in the OSD request if this is a data | |
664 | * integrity write (e.g., O_SYNC write or fsync()), or if our | |
665 | * cap is being revoked. | |
666 | */ | |
667 | do_sync = wbc->sync_mode == WB_SYNC_ALL; | |
668 | if (ceph_caps_revoking(ci, CEPH_CAP_FILE_BUFFER)) | |
669 | do_sync = 1; | |
670 | dout("writepages_start %p dosync=%d (mode=%s)\n", | |
671 | inode, do_sync, | |
672 | wbc->sync_mode == WB_SYNC_NONE ? "NONE" : | |
673 | (wbc->sync_mode == WB_SYNC_ALL ? "ALL" : "HOLD")); | |
674 | ||
3d14c5d2 YS |
675 | fsc = ceph_inode_to_client(inode); |
676 | if (fsc->mount_state == CEPH_MOUNT_SHUTDOWN) { | |
1d3576fd SW |
677 | pr_warning("writepage_start %p on forced umount\n", inode); |
678 | return -EIO; /* we're in a forced umount, don't write! */ | |
679 | } | |
3d14c5d2 YS |
680 | if (fsc->mount_options->wsize && fsc->mount_options->wsize < wsize) |
681 | wsize = fsc->mount_options->wsize; | |
1d3576fd SW |
682 | if (wsize < PAGE_CACHE_SIZE) |
683 | wsize = PAGE_CACHE_SIZE; | |
684 | max_pages_ever = wsize >> PAGE_CACHE_SHIFT; | |
685 | ||
686 | pagevec_init(&pvec, 0); | |
687 | ||
1d3576fd SW |
688 | /* where to start/end? */ |
689 | if (wbc->range_cyclic) { | |
690 | start = mapping->writeback_index; /* Start from prev offset */ | |
691 | end = -1; | |
692 | dout(" cyclic, start at %lu\n", start); | |
693 | } else { | |
694 | start = wbc->range_start >> PAGE_CACHE_SHIFT; | |
695 | end = wbc->range_end >> PAGE_CACHE_SHIFT; | |
696 | if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) | |
697 | range_whole = 1; | |
698 | should_loop = 0; | |
699 | dout(" not cyclic, %lu to %lu\n", start, end); | |
700 | } | |
701 | index = start; | |
702 | ||
703 | retry: | |
704 | /* find oldest snap context with dirty data */ | |
705 | ceph_put_snap_context(snapc); | |
706 | snapc = get_oldest_context(inode, &snap_size); | |
707 | if (!snapc) { | |
708 | /* hmm, why does writepages get called when there | |
709 | is no dirty data? */ | |
710 | dout(" no snap context with dirty data?\n"); | |
711 | goto out; | |
712 | } | |
713 | dout(" oldest snapc is %p seq %lld (%d snaps)\n", | |
714 | snapc, snapc->seq, snapc->num_snaps); | |
715 | if (last_snapc && snapc != last_snapc) { | |
716 | /* if we switched to a newer snapc, restart our scan at the | |
717 | * start of the original file range. */ | |
718 | dout(" snapc differs from last pass, restarting at %lu\n", | |
719 | index); | |
720 | index = start; | |
721 | } | |
722 | last_snapc = snapc; | |
723 | ||
724 | while (!done && index <= end) { | |
725 | unsigned i; | |
726 | int first; | |
727 | pgoff_t next; | |
728 | int pvec_pages, locked_pages; | |
729 | struct page *page; | |
730 | int want; | |
731 | u64 offset, len; | |
732 | struct ceph_osd_request_head *reqhead; | |
733 | struct ceph_osd_op *op; | |
2baba250 | 734 | long writeback_stat; |
1d3576fd SW |
735 | |
736 | next = 0; | |
737 | locked_pages = 0; | |
738 | max_pages = max_pages_ever; | |
739 | ||
740 | get_more_pages: | |
741 | first = -1; | |
742 | want = min(end - index, | |
743 | min((pgoff_t)PAGEVEC_SIZE, | |
744 | max_pages - (pgoff_t)locked_pages) - 1) | |
745 | + 1; | |
746 | pvec_pages = pagevec_lookup_tag(&pvec, mapping, &index, | |
747 | PAGECACHE_TAG_DIRTY, | |
748 | want); | |
749 | dout("pagevec_lookup_tag got %d\n", pvec_pages); | |
750 | if (!pvec_pages && !locked_pages) | |
751 | break; | |
752 | for (i = 0; i < pvec_pages && locked_pages < max_pages; i++) { | |
753 | page = pvec.pages[i]; | |
754 | dout("? %p idx %lu\n", page, page->index); | |
755 | if (locked_pages == 0) | |
756 | lock_page(page); /* first page */ | |
757 | else if (!trylock_page(page)) | |
758 | break; | |
759 | ||
760 | /* only dirty pages, or our accounting breaks */ | |
761 | if (unlikely(!PageDirty(page)) || | |
762 | unlikely(page->mapping != mapping)) { | |
763 | dout("!dirty or !mapping %p\n", page); | |
764 | unlock_page(page); | |
765 | break; | |
766 | } | |
767 | if (!wbc->range_cyclic && page->index > end) { | |
768 | dout("end of range %p\n", page); | |
769 | done = 1; | |
770 | unlock_page(page); | |
771 | break; | |
772 | } | |
773 | if (next && (page->index != next)) { | |
774 | dout("not consecutive %p\n", page); | |
775 | unlock_page(page); | |
776 | break; | |
777 | } | |
778 | if (wbc->sync_mode != WB_SYNC_NONE) { | |
779 | dout("waiting on writeback %p\n", page); | |
780 | wait_on_page_writeback(page); | |
781 | } | |
782 | if ((snap_size && page_offset(page) > snap_size) || | |
783 | (!snap_size && | |
784 | page_offset(page) > i_size_read(inode))) { | |
785 | dout("%p page eof %llu\n", page, snap_size ? | |
786 | snap_size : i_size_read(inode)); | |
787 | done = 1; | |
788 | unlock_page(page); | |
789 | break; | |
790 | } | |
791 | if (PageWriteback(page)) { | |
792 | dout("%p under writeback\n", page); | |
793 | unlock_page(page); | |
794 | break; | |
795 | } | |
796 | ||
797 | /* only if matching snap context */ | |
80e755fe SW |
798 | pgsnapc = (void *)page->private; |
799 | if (pgsnapc->seq > snapc->seq) { | |
800 | dout("page snapc %p %lld > oldest %p %lld\n", | |
801 | pgsnapc, pgsnapc->seq, snapc, snapc->seq); | |
1d3576fd SW |
802 | unlock_page(page); |
803 | if (!locked_pages) | |
804 | continue; /* keep looking for snap */ | |
805 | break; | |
806 | } | |
807 | ||
808 | if (!clear_page_dirty_for_io(page)) { | |
809 | dout("%p !clear_page_dirty_for_io\n", page); | |
810 | unlock_page(page); | |
811 | break; | |
812 | } | |
813 | ||
814 | /* ok */ | |
815 | if (locked_pages == 0) { | |
816 | /* prepare async write request */ | |
a77d9f7d SW |
817 | offset = (unsigned long long)page->index |
818 | << PAGE_CACHE_SHIFT; | |
1d3576fd | 819 | len = wsize; |
3d14c5d2 | 820 | req = ceph_osdc_new_request(&fsc->client->osdc, |
1d3576fd SW |
821 | &ci->i_layout, |
822 | ceph_vino(inode), | |
823 | offset, &len, | |
824 | CEPH_OSD_OP_WRITE, | |
825 | CEPH_OSD_FLAG_WRITE | | |
826 | CEPH_OSD_FLAG_ONDISK, | |
827 | snapc, do_sync, | |
828 | ci->i_truncate_seq, | |
829 | ci->i_truncate_size, | |
b7495fc2 | 830 | &inode->i_mtime, true, 1, 0); |
8c71897b HC |
831 | |
832 | if (!req) { | |
833 | rc = -ENOMEM; | |
834 | unlock_page(page); | |
835 | break; | |
836 | } | |
837 | ||
1d3576fd SW |
838 | max_pages = req->r_num_pages; |
839 | ||
3d14c5d2 | 840 | alloc_page_vec(fsc, req); |
1d3576fd SW |
841 | req->r_callback = writepages_finish; |
842 | req->r_inode = inode; | |
1d3576fd SW |
843 | } |
844 | ||
845 | /* note position of first page in pvec */ | |
846 | if (first < 0) | |
847 | first = i; | |
848 | dout("%p will write page %p idx %lu\n", | |
849 | inode, page, page->index); | |
2baba250 | 850 | |
213c99ee | 851 | writeback_stat = |
3d14c5d2 | 852 | atomic_long_inc_return(&fsc->writeback_count); |
213c99ee | 853 | if (writeback_stat > CONGESTION_ON_THRESH( |
3d14c5d2 YS |
854 | fsc->mount_options->congestion_kb)) { |
855 | set_bdi_congested(&fsc->backing_dev_info, | |
213c99ee | 856 | BLK_RW_ASYNC); |
2baba250 YS |
857 | } |
858 | ||
1d3576fd SW |
859 | set_page_writeback(page); |
860 | req->r_pages[locked_pages] = page; | |
861 | locked_pages++; | |
862 | next = page->index + 1; | |
863 | } | |
864 | ||
865 | /* did we get anything? */ | |
866 | if (!locked_pages) | |
867 | goto release_pvec_pages; | |
868 | if (i) { | |
869 | int j; | |
870 | BUG_ON(!locked_pages || first < 0); | |
871 | ||
872 | if (pvec_pages && i == pvec_pages && | |
873 | locked_pages < max_pages) { | |
874 | dout("reached end pvec, trying for more\n"); | |
875 | pagevec_reinit(&pvec); | |
876 | goto get_more_pages; | |
877 | } | |
878 | ||
879 | /* shift unused pages over in the pvec... we | |
880 | * will need to release them below. */ | |
881 | for (j = i; j < pvec_pages; j++) { | |
882 | dout(" pvec leftover page %p\n", | |
883 | pvec.pages[j]); | |
884 | pvec.pages[j-i+first] = pvec.pages[j]; | |
885 | } | |
886 | pvec.nr -= i-first; | |
887 | } | |
888 | ||
889 | /* submit the write */ | |
890 | offset = req->r_pages[0]->index << PAGE_CACHE_SHIFT; | |
891 | len = min((snap_size ? snap_size : i_size_read(inode)) - offset, | |
892 | (u64)locked_pages << PAGE_CACHE_SHIFT); | |
893 | dout("writepages got %d pages at %llu~%llu\n", | |
894 | locked_pages, offset, len); | |
895 | ||
896 | /* revise final length, page count */ | |
897 | req->r_num_pages = locked_pages; | |
898 | reqhead = req->r_request->front.iov_base; | |
899 | op = (void *)(reqhead + 1); | |
900 | op->extent.length = cpu_to_le64(len); | |
901 | op->payload_len = cpu_to_le32(len); | |
902 | req->r_request->hdr.data_len = cpu_to_le32(len); | |
903 | ||
9d6fcb08 SW |
904 | rc = ceph_osdc_start_request(&fsc->client->osdc, req, true); |
905 | BUG_ON(rc); | |
1d3576fd SW |
906 | req = NULL; |
907 | ||
908 | /* continue? */ | |
909 | index = next; | |
910 | wbc->nr_to_write -= locked_pages; | |
911 | if (wbc->nr_to_write <= 0) | |
912 | done = 1; | |
913 | ||
914 | release_pvec_pages: | |
915 | dout("pagevec_release on %d pages (%p)\n", (int)pvec.nr, | |
916 | pvec.nr ? pvec.pages[0] : NULL); | |
917 | pagevec_release(&pvec); | |
918 | ||
919 | if (locked_pages && !done) | |
920 | goto retry; | |
921 | } | |
922 | ||
923 | if (should_loop && !done) { | |
924 | /* more to do; loop back to beginning of file */ | |
925 | dout("writepages looping back to beginning of file\n"); | |
926 | should_loop = 0; | |
927 | index = 0; | |
928 | goto retry; | |
929 | } | |
930 | ||
931 | if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0)) | |
932 | mapping->writeback_index = index; | |
933 | ||
934 | out: | |
935 | if (req) | |
936 | ceph_osdc_put_request(req); | |
1d3576fd SW |
937 | ceph_put_snap_context(snapc); |
938 | dout("writepages done, rc = %d\n", rc); | |
1d3576fd SW |
939 | return rc; |
940 | } | |
941 | ||
942 | ||
943 | ||
944 | /* | |
945 | * See if a given @snapc is either writeable, or already written. | |
946 | */ | |
947 | static int context_is_writeable_or_written(struct inode *inode, | |
948 | struct ceph_snap_context *snapc) | |
949 | { | |
950 | struct ceph_snap_context *oldest = get_oldest_context(inode, NULL); | |
6298a337 SW |
951 | int ret = !oldest || snapc->seq <= oldest->seq; |
952 | ||
953 | ceph_put_snap_context(oldest); | |
954 | return ret; | |
1d3576fd SW |
955 | } |
956 | ||
957 | /* | |
958 | * We are only allowed to write into/dirty the page if the page is | |
959 | * clean, or already dirty within the same snap context. | |
8f883c24 SW |
960 | * |
961 | * called with page locked. | |
962 | * return success with page locked, | |
963 | * or any failure (incl -EAGAIN) with page unlocked. | |
1d3576fd | 964 | */ |
4af6b225 YS |
965 | static int ceph_update_writeable_page(struct file *file, |
966 | loff_t pos, unsigned len, | |
967 | struct page *page) | |
1d3576fd SW |
968 | { |
969 | struct inode *inode = file->f_dentry->d_inode; | |
970 | struct ceph_inode_info *ci = ceph_inode(inode); | |
3d14c5d2 | 971 | struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc; |
1d3576fd SW |
972 | loff_t page_off = pos & PAGE_CACHE_MASK; |
973 | int pos_in_page = pos & ~PAGE_CACHE_MASK; | |
974 | int end_in_page = pos_in_page + len; | |
975 | loff_t i_size; | |
1d3576fd | 976 | int r; |
80e755fe | 977 | struct ceph_snap_context *snapc, *oldest; |
1d3576fd | 978 | |
1d3576fd SW |
979 | retry_locked: |
980 | /* writepages currently holds page lock, but if we change that later, */ | |
981 | wait_on_page_writeback(page); | |
982 | ||
983 | /* check snap context */ | |
984 | BUG_ON(!ci->i_snap_realm); | |
985 | down_read(&mdsc->snap_rwsem); | |
986 | BUG_ON(!ci->i_snap_realm->cached_context); | |
80e755fe SW |
987 | snapc = (void *)page->private; |
988 | if (snapc && snapc != ci->i_head_snapc) { | |
1d3576fd SW |
989 | /* |
990 | * this page is already dirty in another (older) snap | |
991 | * context! is it writeable now? | |
992 | */ | |
80e755fe | 993 | oldest = get_oldest_context(inode, NULL); |
1d3576fd SW |
994 | up_read(&mdsc->snap_rwsem); |
995 | ||
80e755fe | 996 | if (snapc->seq > oldest->seq) { |
6298a337 | 997 | ceph_put_snap_context(oldest); |
1d3576fd | 998 | dout(" page %p snapc %p not current or oldest\n", |
6298a337 | 999 | page, snapc); |
1d3576fd SW |
1000 | /* |
1001 | * queue for writeback, and wait for snapc to | |
1002 | * be writeable or written | |
1003 | */ | |
6298a337 | 1004 | snapc = ceph_get_snap_context(snapc); |
1d3576fd | 1005 | unlock_page(page); |
3c6f6b79 | 1006 | ceph_queue_writeback(inode); |
8f883c24 | 1007 | r = wait_event_interruptible(ci->i_cap_wq, |
1d3576fd SW |
1008 | context_is_writeable_or_written(inode, snapc)); |
1009 | ceph_put_snap_context(snapc); | |
8f883c24 SW |
1010 | if (r == -ERESTARTSYS) |
1011 | return r; | |
4af6b225 | 1012 | return -EAGAIN; |
1d3576fd | 1013 | } |
6298a337 | 1014 | ceph_put_snap_context(oldest); |
1d3576fd SW |
1015 | |
1016 | /* yay, writeable, do it now (without dropping page lock) */ | |
1017 | dout(" page %p snapc %p not current, but oldest\n", | |
1018 | page, snapc); | |
1019 | if (!clear_page_dirty_for_io(page)) | |
1020 | goto retry_locked; | |
1021 | r = writepage_nounlock(page, NULL); | |
1022 | if (r < 0) | |
1023 | goto fail_nosnap; | |
1024 | goto retry_locked; | |
1025 | } | |
1026 | ||
1027 | if (PageUptodate(page)) { | |
1028 | dout(" page %p already uptodate\n", page); | |
1029 | return 0; | |
1030 | } | |
1031 | ||
1032 | /* full page? */ | |
1033 | if (pos_in_page == 0 && len == PAGE_CACHE_SIZE) | |
1034 | return 0; | |
1035 | ||
1036 | /* past end of file? */ | |
1037 | i_size = inode->i_size; /* caller holds i_mutex */ | |
1038 | ||
1039 | if (i_size + len > inode->i_sb->s_maxbytes) { | |
1040 | /* file is too big */ | |
1041 | r = -EINVAL; | |
1042 | goto fail; | |
1043 | } | |
1044 | ||
1045 | if (page_off >= i_size || | |
1046 | (pos_in_page == 0 && (pos+len) >= i_size && | |
1047 | end_in_page - pos_in_page != PAGE_CACHE_SIZE)) { | |
1048 | dout(" zeroing %p 0 - %d and %d - %d\n", | |
1049 | page, pos_in_page, end_in_page, (int)PAGE_CACHE_SIZE); | |
1050 | zero_user_segments(page, | |
1051 | 0, pos_in_page, | |
1052 | end_in_page, PAGE_CACHE_SIZE); | |
1053 | return 0; | |
1054 | } | |
1055 | ||
1056 | /* we need to read it. */ | |
1057 | up_read(&mdsc->snap_rwsem); | |
1058 | r = readpage_nounlock(file, page); | |
1059 | if (r < 0) | |
1060 | goto fail_nosnap; | |
1061 | goto retry_locked; | |
1062 | ||
1063 | fail: | |
1064 | up_read(&mdsc->snap_rwsem); | |
1065 | fail_nosnap: | |
1066 | unlock_page(page); | |
1067 | return r; | |
1068 | } | |
1069 | ||
4af6b225 YS |
1070 | /* |
1071 | * We are only allowed to write into/dirty the page if the page is | |
1072 | * clean, or already dirty within the same snap context. | |
1073 | */ | |
1074 | static int ceph_write_begin(struct file *file, struct address_space *mapping, | |
1075 | loff_t pos, unsigned len, unsigned flags, | |
1076 | struct page **pagep, void **fsdata) | |
1077 | { | |
1078 | struct inode *inode = file->f_dentry->d_inode; | |
1079 | struct page *page; | |
1080 | pgoff_t index = pos >> PAGE_CACHE_SHIFT; | |
1081 | int r; | |
1082 | ||
1083 | do { | |
8f883c24 | 1084 | /* get a page */ |
4af6b225 YS |
1085 | page = grab_cache_page_write_begin(mapping, index, 0); |
1086 | if (!page) | |
1087 | return -ENOMEM; | |
1088 | *pagep = page; | |
1089 | ||
1090 | dout("write_begin file %p inode %p page %p %d~%d\n", file, | |
213c99ee | 1091 | inode, page, (int)pos, (int)len); |
4af6b225 YS |
1092 | |
1093 | r = ceph_update_writeable_page(file, pos, len, page); | |
1094 | } while (r == -EAGAIN); | |
1095 | ||
1096 | return r; | |
1097 | } | |
1098 | ||
1d3576fd SW |
1099 | /* |
1100 | * we don't do anything in here that simple_write_end doesn't do | |
1101 | * except adjust dirty page accounting and drop read lock on | |
1102 | * mdsc->snap_rwsem. | |
1103 | */ | |
1104 | static int ceph_write_end(struct file *file, struct address_space *mapping, | |
1105 | loff_t pos, unsigned len, unsigned copied, | |
1106 | struct page *page, void *fsdata) | |
1107 | { | |
1108 | struct inode *inode = file->f_dentry->d_inode; | |
3d14c5d2 YS |
1109 | struct ceph_fs_client *fsc = ceph_inode_to_client(inode); |
1110 | struct ceph_mds_client *mdsc = fsc->mdsc; | |
1d3576fd SW |
1111 | unsigned from = pos & (PAGE_CACHE_SIZE - 1); |
1112 | int check_cap = 0; | |
1113 | ||
1114 | dout("write_end file %p inode %p page %p %d~%d (%d)\n", file, | |
1115 | inode, page, (int)pos, (int)copied, (int)len); | |
1116 | ||
1117 | /* zero the stale part of the page if we did a short copy */ | |
1118 | if (copied < len) | |
1119 | zero_user_segment(page, from+copied, len); | |
1120 | ||
1121 | /* did file size increase? */ | |
1122 | /* (no need for i_size_read(); we caller holds i_mutex */ | |
1123 | if (pos+copied > inode->i_size) | |
1124 | check_cap = ceph_inode_set_size(inode, pos+copied); | |
1125 | ||
1126 | if (!PageUptodate(page)) | |
1127 | SetPageUptodate(page); | |
1128 | ||
1129 | set_page_dirty(page); | |
1130 | ||
1131 | unlock_page(page); | |
1132 | up_read(&mdsc->snap_rwsem); | |
1133 | page_cache_release(page); | |
1134 | ||
1135 | if (check_cap) | |
1136 | ceph_check_caps(ceph_inode(inode), CHECK_CAPS_AUTHONLY, NULL); | |
1137 | ||
1138 | return copied; | |
1139 | } | |
1140 | ||
1141 | /* | |
1142 | * we set .direct_IO to indicate direct io is supported, but since we | |
1143 | * intercept O_DIRECT reads and writes early, this function should | |
1144 | * never get called. | |
1145 | */ | |
1146 | static ssize_t ceph_direct_io(int rw, struct kiocb *iocb, | |
1147 | const struct iovec *iov, | |
1148 | loff_t pos, unsigned long nr_segs) | |
1149 | { | |
1150 | WARN_ON(1); | |
1151 | return -EINVAL; | |
1152 | } | |
1153 | ||
1154 | const struct address_space_operations ceph_aops = { | |
1155 | .readpage = ceph_readpage, | |
1156 | .readpages = ceph_readpages, | |
1157 | .writepage = ceph_writepage, | |
1158 | .writepages = ceph_writepages_start, | |
1159 | .write_begin = ceph_write_begin, | |
1160 | .write_end = ceph_write_end, | |
1161 | .set_page_dirty = ceph_set_page_dirty, | |
1162 | .invalidatepage = ceph_invalidatepage, | |
1163 | .releasepage = ceph_releasepage, | |
1164 | .direct_IO = ceph_direct_io, | |
1165 | }; | |
1166 | ||
1167 | ||
1168 | /* | |
1169 | * vm ops | |
1170 | */ | |
1171 | ||
1172 | /* | |
1173 | * Reuse write_begin here for simplicity. | |
1174 | */ | |
1175 | static int ceph_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) | |
1176 | { | |
1177 | struct inode *inode = vma->vm_file->f_dentry->d_inode; | |
1178 | struct page *page = vmf->page; | |
3d14c5d2 | 1179 | struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc; |
1d3576fd SW |
1180 | loff_t off = page->index << PAGE_CACHE_SHIFT; |
1181 | loff_t size, len; | |
1d3576fd SW |
1182 | int ret; |
1183 | ||
1184 | size = i_size_read(inode); | |
1185 | if (off + PAGE_CACHE_SIZE <= size) | |
1186 | len = PAGE_CACHE_SIZE; | |
1187 | else | |
1188 | len = size & ~PAGE_CACHE_MASK; | |
1189 | ||
1190 | dout("page_mkwrite %p %llu~%llu page %p idx %lu\n", inode, | |
1191 | off, len, page, page->index); | |
4af6b225 YS |
1192 | |
1193 | lock_page(page); | |
1194 | ||
1195 | ret = VM_FAULT_NOPAGE; | |
1196 | if ((off > size) || | |
1197 | (page->mapping != inode->i_mapping)) | |
1198 | goto out; | |
1199 | ||
1200 | ret = ceph_update_writeable_page(vma->vm_file, off, len, page); | |
1201 | if (ret == 0) { | |
1202 | /* success. we'll keep the page locked. */ | |
1d3576fd SW |
1203 | set_page_dirty(page); |
1204 | up_read(&mdsc->snap_rwsem); | |
1d3576fd SW |
1205 | ret = VM_FAULT_LOCKED; |
1206 | } else { | |
4af6b225 YS |
1207 | if (ret == -ENOMEM) |
1208 | ret = VM_FAULT_OOM; | |
1209 | else | |
1210 | ret = VM_FAULT_SIGBUS; | |
1d3576fd | 1211 | } |
4af6b225 | 1212 | out: |
1d3576fd | 1213 | dout("page_mkwrite %p %llu~%llu = %d\n", inode, off, len, ret); |
4af6b225 YS |
1214 | if (ret != VM_FAULT_LOCKED) |
1215 | unlock_page(page); | |
1d3576fd SW |
1216 | return ret; |
1217 | } | |
1218 | ||
1219 | static struct vm_operations_struct ceph_vmops = { | |
1220 | .fault = filemap_fault, | |
1221 | .page_mkwrite = ceph_page_mkwrite, | |
1222 | }; | |
1223 | ||
1224 | int ceph_mmap(struct file *file, struct vm_area_struct *vma) | |
1225 | { | |
1226 | struct address_space *mapping = file->f_mapping; | |
1227 | ||
1228 | if (!mapping->a_ops->readpage) | |
1229 | return -ENOEXEC; | |
1230 | file_accessed(file); | |
1231 | vma->vm_ops = &ceph_vmops; | |
1232 | vma->vm_flags |= VM_CAN_NONLINEAR; | |
1233 | return 0; | |
1234 | } |