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 | */ |
7c272194 | 271 | static int start_read(struct inode *inode, struct list_head *page_list) |
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++; | |
295 | } | |
1d3576fd | 296 | len = nr_pages << PAGE_CACHE_SHIFT; |
7c272194 SW |
297 | dout("start_read %p nr_pages %d is %lld~%lld\n", inode, nr_pages, |
298 | off, len); | |
299 | ||
300 | req = ceph_osdc_new_request(osdc, &ci->i_layout, ceph_vino(inode), | |
301 | off, &len, | |
302 | CEPH_OSD_OP_READ, CEPH_OSD_FLAG_READ, | |
303 | NULL, 0, | |
304 | ci->i_truncate_seq, ci->i_truncate_size, | |
305 | NULL, false, 1, 0); | |
306 | if (!req) | |
307 | return -ENOMEM; | |
1d3576fd | 308 | |
7c272194 SW |
309 | /* build page vector */ |
310 | nr_pages = len >> PAGE_CACHE_SHIFT; | |
311 | pages = kmalloc(sizeof(*pages) * nr_pages, GFP_NOFS); | |
312 | ret = -ENOMEM; | |
313 | if (!pages) | |
314 | goto out; | |
315 | for (i = 0; i < nr_pages; ++i) { | |
316 | page = list_entry(page_list->prev, struct page, lru); | |
317 | BUG_ON(PageLocked(page)); | |
1d3576fd | 318 | list_del(&page->lru); |
7c272194 SW |
319 | |
320 | dout("start_read %p adding %p idx %lu\n", inode, page, | |
321 | page->index); | |
322 | if (add_to_page_cache_lru(page, &inode->i_data, page->index, | |
213c99ee | 323 | GFP_NOFS)) { |
1d3576fd | 324 | page_cache_release(page); |
7c272194 | 325 | dout("start_read %p add_to_page_cache failed %p\n", |
1d3576fd | 326 | inode, page); |
7c272194 SW |
327 | nr_pages = i; |
328 | goto out_pages; | |
1d3576fd | 329 | } |
7c272194 | 330 | pages[i] = page; |
1d3576fd | 331 | } |
7c272194 SW |
332 | req->r_pages = pages; |
333 | req->r_num_pages = nr_pages; | |
334 | req->r_callback = finish_read; | |
335 | req->r_inode = inode; | |
336 | ||
337 | dout("start_read %p starting %p %lld~%lld\n", inode, req, off, len); | |
338 | ret = ceph_osdc_start_request(osdc, req, false); | |
339 | if (ret < 0) | |
340 | goto out_pages; | |
341 | ceph_osdc_put_request(req); | |
342 | return nr_pages; | |
343 | ||
344 | out_pages: | |
345 | ceph_release_page_vector(pages, nr_pages); | |
346 | kfree(pages); | |
347 | out: | |
348 | ceph_osdc_put_request(req); | |
349 | return ret; | |
350 | } | |
1d3576fd | 351 | |
7c272194 SW |
352 | |
353 | /* | |
354 | * Read multiple pages. Leave pages we don't read + unlock in page_list; | |
355 | * the caller (VM) cleans them up. | |
356 | */ | |
357 | static int ceph_readpages(struct file *file, struct address_space *mapping, | |
358 | struct list_head *page_list, unsigned nr_pages) | |
359 | { | |
360 | struct inode *inode = file->f_dentry->d_inode; | |
361 | int rc = 0; | |
362 | ||
363 | dout("readpages %p file %p nr_pages %d\n", inode, file, nr_pages); | |
364 | while (!list_empty(page_list)) { | |
365 | rc = start_read(inode, page_list); | |
366 | if (rc < 0) | |
367 | goto out; | |
368 | BUG_ON(rc == 0); | |
369 | } | |
1d3576fd | 370 | out: |
7c272194 | 371 | dout("readpages %p file %p ret %d\n", inode, file, rc); |
1d3576fd SW |
372 | return rc; |
373 | } | |
374 | ||
375 | /* | |
376 | * Get ref for the oldest snapc for an inode with dirty data... that is, the | |
377 | * only snap context we are allowed to write back. | |
1d3576fd | 378 | */ |
6298a337 SW |
379 | static struct ceph_snap_context *get_oldest_context(struct inode *inode, |
380 | u64 *snap_size) | |
1d3576fd SW |
381 | { |
382 | struct ceph_inode_info *ci = ceph_inode(inode); | |
383 | struct ceph_snap_context *snapc = NULL; | |
384 | struct ceph_cap_snap *capsnap = NULL; | |
385 | ||
6298a337 | 386 | spin_lock(&inode->i_lock); |
1d3576fd SW |
387 | list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) { |
388 | dout(" cap_snap %p snapc %p has %d dirty pages\n", capsnap, | |
389 | capsnap->context, capsnap->dirty_pages); | |
390 | if (capsnap->dirty_pages) { | |
391 | snapc = ceph_get_snap_context(capsnap->context); | |
392 | if (snap_size) | |
393 | *snap_size = capsnap->size; | |
394 | break; | |
395 | } | |
396 | } | |
7d8cb26d | 397 | if (!snapc && ci->i_wrbuffer_ref_head) { |
80e755fe | 398 | snapc = ceph_get_snap_context(ci->i_head_snapc); |
1d3576fd SW |
399 | dout(" head snapc %p has %d dirty pages\n", |
400 | snapc, ci->i_wrbuffer_ref_head); | |
401 | } | |
1d3576fd SW |
402 | spin_unlock(&inode->i_lock); |
403 | return snapc; | |
404 | } | |
405 | ||
406 | /* | |
407 | * Write a single page, but leave the page locked. | |
408 | * | |
409 | * If we get a write error, set the page error bit, but still adjust the | |
410 | * dirty page accounting (i.e., page is no longer dirty). | |
411 | */ | |
412 | static int writepage_nounlock(struct page *page, struct writeback_control *wbc) | |
413 | { | |
414 | struct inode *inode; | |
415 | struct ceph_inode_info *ci; | |
3d14c5d2 | 416 | struct ceph_fs_client *fsc; |
1d3576fd SW |
417 | struct ceph_osd_client *osdc; |
418 | loff_t page_off = page->index << PAGE_CACHE_SHIFT; | |
419 | int len = PAGE_CACHE_SIZE; | |
420 | loff_t i_size; | |
421 | int err = 0; | |
6298a337 | 422 | struct ceph_snap_context *snapc, *oldest; |
1d3576fd | 423 | u64 snap_size = 0; |
2baba250 | 424 | long writeback_stat; |
1d3576fd SW |
425 | |
426 | dout("writepage %p idx %lu\n", page, page->index); | |
427 | ||
428 | if (!page->mapping || !page->mapping->host) { | |
429 | dout("writepage %p - no mapping\n", page); | |
430 | return -EFAULT; | |
431 | } | |
432 | inode = page->mapping->host; | |
433 | ci = ceph_inode(inode); | |
3d14c5d2 YS |
434 | fsc = ceph_inode_to_client(inode); |
435 | osdc = &fsc->client->osdc; | |
1d3576fd SW |
436 | |
437 | /* verify this is a writeable snap context */ | |
438 | snapc = (void *)page->private; | |
439 | if (snapc == NULL) { | |
440 | dout("writepage %p page %p not dirty?\n", inode, page); | |
441 | goto out; | |
442 | } | |
6298a337 SW |
443 | oldest = get_oldest_context(inode, &snap_size); |
444 | if (snapc->seq > oldest->seq) { | |
1d3576fd SW |
445 | dout("writepage %p page %p snapc %p not writeable - noop\n", |
446 | inode, page, (void *)page->private); | |
447 | /* we should only noop if called by kswapd */ | |
448 | WARN_ON((current->flags & PF_MEMALLOC) == 0); | |
6298a337 | 449 | ceph_put_snap_context(oldest); |
1d3576fd SW |
450 | goto out; |
451 | } | |
6298a337 | 452 | ceph_put_snap_context(oldest); |
1d3576fd SW |
453 | |
454 | /* is this a partial page at end of file? */ | |
455 | if (snap_size) | |
456 | i_size = snap_size; | |
457 | else | |
458 | i_size = i_size_read(inode); | |
459 | if (i_size < page_off + len) | |
460 | len = i_size - page_off; | |
461 | ||
ae00d4f3 SW |
462 | dout("writepage %p page %p index %lu on %llu~%u snapc %p\n", |
463 | inode, page, page->index, page_off, len, snapc); | |
1d3576fd | 464 | |
3d14c5d2 | 465 | writeback_stat = atomic_long_inc_return(&fsc->writeback_count); |
2baba250 | 466 | if (writeback_stat > |
3d14c5d2 YS |
467 | CONGESTION_ON_THRESH(fsc->mount_options->congestion_kb)) |
468 | set_bdi_congested(&fsc->backing_dev_info, BLK_RW_ASYNC); | |
2baba250 | 469 | |
1d3576fd SW |
470 | set_page_writeback(page); |
471 | err = ceph_osdc_writepages(osdc, ceph_vino(inode), | |
472 | &ci->i_layout, snapc, | |
473 | page_off, len, | |
474 | ci->i_truncate_seq, ci->i_truncate_size, | |
475 | &inode->i_mtime, | |
476 | &page, 1, 0, 0, true); | |
477 | if (err < 0) { | |
478 | dout("writepage setting page/mapping error %d %p\n", err, page); | |
479 | SetPageError(page); | |
480 | mapping_set_error(&inode->i_data, err); | |
481 | if (wbc) | |
482 | wbc->pages_skipped++; | |
483 | } else { | |
484 | dout("writepage cleaned page %p\n", page); | |
485 | err = 0; /* vfs expects us to return 0 */ | |
486 | } | |
487 | page->private = 0; | |
488 | ClearPagePrivate(page); | |
489 | end_page_writeback(page); | |
490 | ceph_put_wrbuffer_cap_refs(ci, 1, snapc); | |
6298a337 | 491 | ceph_put_snap_context(snapc); /* page's reference */ |
1d3576fd SW |
492 | out: |
493 | return err; | |
494 | } | |
495 | ||
496 | static int ceph_writepage(struct page *page, struct writeback_control *wbc) | |
497 | { | |
dbd646a8 YS |
498 | int err; |
499 | struct inode *inode = page->mapping->host; | |
500 | BUG_ON(!inode); | |
70b666c3 | 501 | ihold(inode); |
dbd646a8 | 502 | err = writepage_nounlock(page, wbc); |
1d3576fd | 503 | unlock_page(page); |
dbd646a8 | 504 | iput(inode); |
1d3576fd SW |
505 | return err; |
506 | } | |
507 | ||
508 | ||
509 | /* | |
510 | * lame release_pages helper. release_pages() isn't exported to | |
511 | * modules. | |
512 | */ | |
513 | static void ceph_release_pages(struct page **pages, int num) | |
514 | { | |
515 | struct pagevec pvec; | |
516 | int i; | |
517 | ||
518 | pagevec_init(&pvec, 0); | |
519 | for (i = 0; i < num; i++) { | |
520 | if (pagevec_add(&pvec, pages[i]) == 0) | |
521 | pagevec_release(&pvec); | |
522 | } | |
523 | pagevec_release(&pvec); | |
524 | } | |
525 | ||
526 | ||
527 | /* | |
528 | * async writeback completion handler. | |
529 | * | |
530 | * If we get an error, set the mapping error bit, but not the individual | |
531 | * page error bits. | |
532 | */ | |
533 | static void writepages_finish(struct ceph_osd_request *req, | |
534 | struct ceph_msg *msg) | |
535 | { | |
536 | struct inode *inode = req->r_inode; | |
537 | struct ceph_osd_reply_head *replyhead; | |
538 | struct ceph_osd_op *op; | |
539 | struct ceph_inode_info *ci = ceph_inode(inode); | |
540 | unsigned wrote; | |
1d3576fd SW |
541 | struct page *page; |
542 | int i; | |
543 | struct ceph_snap_context *snapc = req->r_snapc; | |
544 | struct address_space *mapping = inode->i_mapping; | |
1d3576fd SW |
545 | __s32 rc = -EIO; |
546 | u64 bytes = 0; | |
3d14c5d2 | 547 | struct ceph_fs_client *fsc = ceph_inode_to_client(inode); |
2baba250 | 548 | long writeback_stat; |
7ff899da | 549 | unsigned issued = ceph_caps_issued(ci); |
1d3576fd SW |
550 | |
551 | /* parse reply */ | |
552 | replyhead = msg->front.iov_base; | |
553 | WARN_ON(le32_to_cpu(replyhead->num_ops) == 0); | |
554 | op = (void *)(replyhead + 1); | |
555 | rc = le32_to_cpu(replyhead->result); | |
556 | bytes = le64_to_cpu(op->extent.length); | |
557 | ||
558 | if (rc >= 0) { | |
79788c69 SW |
559 | /* |
560 | * Assume we wrote the pages we originally sent. The | |
561 | * osd might reply with fewer pages if our writeback | |
562 | * raced with a truncation and was adjusted at the osd, | |
563 | * so don't believe the reply. | |
564 | */ | |
565 | wrote = req->r_num_pages; | |
1d3576fd SW |
566 | } else { |
567 | wrote = 0; | |
568 | mapping_set_error(mapping, rc); | |
569 | } | |
570 | dout("writepages_finish %p rc %d bytes %llu wrote %d (pages)\n", | |
571 | inode, rc, bytes, wrote); | |
572 | ||
573 | /* clean all pages */ | |
574 | for (i = 0; i < req->r_num_pages; i++) { | |
575 | page = req->r_pages[i]; | |
576 | BUG_ON(!page); | |
577 | WARN_ON(!PageUptodate(page)); | |
578 | ||
2baba250 | 579 | writeback_stat = |
3d14c5d2 | 580 | atomic_long_dec_return(&fsc->writeback_count); |
2baba250 | 581 | if (writeback_stat < |
3d14c5d2 YS |
582 | CONGESTION_OFF_THRESH(fsc->mount_options->congestion_kb)) |
583 | clear_bdi_congested(&fsc->backing_dev_info, | |
2baba250 YS |
584 | BLK_RW_ASYNC); |
585 | ||
80e755fe | 586 | ceph_put_snap_context((void *)page->private); |
1d3576fd SW |
587 | page->private = 0; |
588 | ClearPagePrivate(page); | |
1d3576fd SW |
589 | dout("unlocking %d %p\n", i, page); |
590 | end_page_writeback(page); | |
e63dc5c7 YS |
591 | |
592 | /* | |
593 | * We lost the cache cap, need to truncate the page before | |
594 | * it is unlocked, otherwise we'd truncate it later in the | |
595 | * page truncation thread, possibly losing some data that | |
596 | * raced its way in | |
597 | */ | |
2962507c | 598 | if ((issued & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) == 0) |
e63dc5c7 YS |
599 | generic_error_remove_page(inode->i_mapping, page); |
600 | ||
1d3576fd SW |
601 | unlock_page(page); |
602 | } | |
603 | dout("%p wrote+cleaned %d pages\n", inode, wrote); | |
604 | ceph_put_wrbuffer_cap_refs(ci, req->r_num_pages, snapc); | |
605 | ||
606 | ceph_release_pages(req->r_pages, req->r_num_pages); | |
607 | if (req->r_pages_from_pool) | |
608 | mempool_free(req->r_pages, | |
640ef79d | 609 | ceph_sb_to_client(inode->i_sb)->wb_pagevec_pool); |
1d3576fd SW |
610 | else |
611 | kfree(req->r_pages); | |
612 | ceph_osdc_put_request(req); | |
613 | } | |
614 | ||
615 | /* | |
616 | * allocate a page vec, either directly, or if necessary, via a the | |
617 | * mempool. we avoid the mempool if we can because req->r_num_pages | |
618 | * may be less than the maximum write size. | |
619 | */ | |
3d14c5d2 | 620 | static void alloc_page_vec(struct ceph_fs_client *fsc, |
1d3576fd SW |
621 | struct ceph_osd_request *req) |
622 | { | |
623 | req->r_pages = kmalloc(sizeof(struct page *) * req->r_num_pages, | |
624 | GFP_NOFS); | |
625 | if (!req->r_pages) { | |
3d14c5d2 | 626 | req->r_pages = mempool_alloc(fsc->wb_pagevec_pool, GFP_NOFS); |
1d3576fd SW |
627 | req->r_pages_from_pool = 1; |
628 | WARN_ON(!req->r_pages); | |
629 | } | |
630 | } | |
631 | ||
632 | /* | |
633 | * initiate async writeback | |
634 | */ | |
635 | static int ceph_writepages_start(struct address_space *mapping, | |
636 | struct writeback_control *wbc) | |
637 | { | |
638 | struct inode *inode = mapping->host; | |
1d3576fd | 639 | struct ceph_inode_info *ci = ceph_inode(inode); |
3d14c5d2 | 640 | struct ceph_fs_client *fsc; |
1d3576fd SW |
641 | pgoff_t index, start, end; |
642 | int range_whole = 0; | |
643 | int should_loop = 1; | |
644 | pgoff_t max_pages = 0, max_pages_ever = 0; | |
80e755fe | 645 | struct ceph_snap_context *snapc = NULL, *last_snapc = NULL, *pgsnapc; |
1d3576fd SW |
646 | struct pagevec pvec; |
647 | int done = 0; | |
648 | int rc = 0; | |
649 | unsigned wsize = 1 << inode->i_blkbits; | |
650 | struct ceph_osd_request *req = NULL; | |
651 | int do_sync; | |
652 | u64 snap_size = 0; | |
653 | ||
654 | /* | |
655 | * Include a 'sync' in the OSD request if this is a data | |
656 | * integrity write (e.g., O_SYNC write or fsync()), or if our | |
657 | * cap is being revoked. | |
658 | */ | |
659 | do_sync = wbc->sync_mode == WB_SYNC_ALL; | |
660 | if (ceph_caps_revoking(ci, CEPH_CAP_FILE_BUFFER)) | |
661 | do_sync = 1; | |
662 | dout("writepages_start %p dosync=%d (mode=%s)\n", | |
663 | inode, do_sync, | |
664 | wbc->sync_mode == WB_SYNC_NONE ? "NONE" : | |
665 | (wbc->sync_mode == WB_SYNC_ALL ? "ALL" : "HOLD")); | |
666 | ||
3d14c5d2 YS |
667 | fsc = ceph_inode_to_client(inode); |
668 | if (fsc->mount_state == CEPH_MOUNT_SHUTDOWN) { | |
1d3576fd SW |
669 | pr_warning("writepage_start %p on forced umount\n", inode); |
670 | return -EIO; /* we're in a forced umount, don't write! */ | |
671 | } | |
3d14c5d2 YS |
672 | if (fsc->mount_options->wsize && fsc->mount_options->wsize < wsize) |
673 | wsize = fsc->mount_options->wsize; | |
1d3576fd SW |
674 | if (wsize < PAGE_CACHE_SIZE) |
675 | wsize = PAGE_CACHE_SIZE; | |
676 | max_pages_ever = wsize >> PAGE_CACHE_SHIFT; | |
677 | ||
678 | pagevec_init(&pvec, 0); | |
679 | ||
1d3576fd SW |
680 | /* where to start/end? */ |
681 | if (wbc->range_cyclic) { | |
682 | start = mapping->writeback_index; /* Start from prev offset */ | |
683 | end = -1; | |
684 | dout(" cyclic, start at %lu\n", start); | |
685 | } else { | |
686 | start = wbc->range_start >> PAGE_CACHE_SHIFT; | |
687 | end = wbc->range_end >> PAGE_CACHE_SHIFT; | |
688 | if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) | |
689 | range_whole = 1; | |
690 | should_loop = 0; | |
691 | dout(" not cyclic, %lu to %lu\n", start, end); | |
692 | } | |
693 | index = start; | |
694 | ||
695 | retry: | |
696 | /* find oldest snap context with dirty data */ | |
697 | ceph_put_snap_context(snapc); | |
698 | snapc = get_oldest_context(inode, &snap_size); | |
699 | if (!snapc) { | |
700 | /* hmm, why does writepages get called when there | |
701 | is no dirty data? */ | |
702 | dout(" no snap context with dirty data?\n"); | |
703 | goto out; | |
704 | } | |
705 | dout(" oldest snapc is %p seq %lld (%d snaps)\n", | |
706 | snapc, snapc->seq, snapc->num_snaps); | |
707 | if (last_snapc && snapc != last_snapc) { | |
708 | /* if we switched to a newer snapc, restart our scan at the | |
709 | * start of the original file range. */ | |
710 | dout(" snapc differs from last pass, restarting at %lu\n", | |
711 | index); | |
712 | index = start; | |
713 | } | |
714 | last_snapc = snapc; | |
715 | ||
716 | while (!done && index <= end) { | |
717 | unsigned i; | |
718 | int first; | |
719 | pgoff_t next; | |
720 | int pvec_pages, locked_pages; | |
721 | struct page *page; | |
722 | int want; | |
723 | u64 offset, len; | |
724 | struct ceph_osd_request_head *reqhead; | |
725 | struct ceph_osd_op *op; | |
2baba250 | 726 | long writeback_stat; |
1d3576fd SW |
727 | |
728 | next = 0; | |
729 | locked_pages = 0; | |
730 | max_pages = max_pages_ever; | |
731 | ||
732 | get_more_pages: | |
733 | first = -1; | |
734 | want = min(end - index, | |
735 | min((pgoff_t)PAGEVEC_SIZE, | |
736 | max_pages - (pgoff_t)locked_pages) - 1) | |
737 | + 1; | |
738 | pvec_pages = pagevec_lookup_tag(&pvec, mapping, &index, | |
739 | PAGECACHE_TAG_DIRTY, | |
740 | want); | |
741 | dout("pagevec_lookup_tag got %d\n", pvec_pages); | |
742 | if (!pvec_pages && !locked_pages) | |
743 | break; | |
744 | for (i = 0; i < pvec_pages && locked_pages < max_pages; i++) { | |
745 | page = pvec.pages[i]; | |
746 | dout("? %p idx %lu\n", page, page->index); | |
747 | if (locked_pages == 0) | |
748 | lock_page(page); /* first page */ | |
749 | else if (!trylock_page(page)) | |
750 | break; | |
751 | ||
752 | /* only dirty pages, or our accounting breaks */ | |
753 | if (unlikely(!PageDirty(page)) || | |
754 | unlikely(page->mapping != mapping)) { | |
755 | dout("!dirty or !mapping %p\n", page); | |
756 | unlock_page(page); | |
757 | break; | |
758 | } | |
759 | if (!wbc->range_cyclic && page->index > end) { | |
760 | dout("end of range %p\n", page); | |
761 | done = 1; | |
762 | unlock_page(page); | |
763 | break; | |
764 | } | |
765 | if (next && (page->index != next)) { | |
766 | dout("not consecutive %p\n", page); | |
767 | unlock_page(page); | |
768 | break; | |
769 | } | |
770 | if (wbc->sync_mode != WB_SYNC_NONE) { | |
771 | dout("waiting on writeback %p\n", page); | |
772 | wait_on_page_writeback(page); | |
773 | } | |
774 | if ((snap_size && page_offset(page) > snap_size) || | |
775 | (!snap_size && | |
776 | page_offset(page) > i_size_read(inode))) { | |
777 | dout("%p page eof %llu\n", page, snap_size ? | |
778 | snap_size : i_size_read(inode)); | |
779 | done = 1; | |
780 | unlock_page(page); | |
781 | break; | |
782 | } | |
783 | if (PageWriteback(page)) { | |
784 | dout("%p under writeback\n", page); | |
785 | unlock_page(page); | |
786 | break; | |
787 | } | |
788 | ||
789 | /* only if matching snap context */ | |
80e755fe SW |
790 | pgsnapc = (void *)page->private; |
791 | if (pgsnapc->seq > snapc->seq) { | |
792 | dout("page snapc %p %lld > oldest %p %lld\n", | |
793 | pgsnapc, pgsnapc->seq, snapc, snapc->seq); | |
1d3576fd SW |
794 | unlock_page(page); |
795 | if (!locked_pages) | |
796 | continue; /* keep looking for snap */ | |
797 | break; | |
798 | } | |
799 | ||
800 | if (!clear_page_dirty_for_io(page)) { | |
801 | dout("%p !clear_page_dirty_for_io\n", page); | |
802 | unlock_page(page); | |
803 | break; | |
804 | } | |
805 | ||
806 | /* ok */ | |
807 | if (locked_pages == 0) { | |
808 | /* prepare async write request */ | |
a77d9f7d SW |
809 | offset = (unsigned long long)page->index |
810 | << PAGE_CACHE_SHIFT; | |
1d3576fd | 811 | len = wsize; |
3d14c5d2 | 812 | req = ceph_osdc_new_request(&fsc->client->osdc, |
1d3576fd SW |
813 | &ci->i_layout, |
814 | ceph_vino(inode), | |
815 | offset, &len, | |
816 | CEPH_OSD_OP_WRITE, | |
817 | CEPH_OSD_FLAG_WRITE | | |
818 | CEPH_OSD_FLAG_ONDISK, | |
819 | snapc, do_sync, | |
820 | ci->i_truncate_seq, | |
821 | ci->i_truncate_size, | |
b7495fc2 | 822 | &inode->i_mtime, true, 1, 0); |
8c71897b HC |
823 | |
824 | if (!req) { | |
825 | rc = -ENOMEM; | |
826 | unlock_page(page); | |
827 | break; | |
828 | } | |
829 | ||
1d3576fd SW |
830 | max_pages = req->r_num_pages; |
831 | ||
3d14c5d2 | 832 | alloc_page_vec(fsc, req); |
1d3576fd SW |
833 | req->r_callback = writepages_finish; |
834 | req->r_inode = inode; | |
1d3576fd SW |
835 | } |
836 | ||
837 | /* note position of first page in pvec */ | |
838 | if (first < 0) | |
839 | first = i; | |
840 | dout("%p will write page %p idx %lu\n", | |
841 | inode, page, page->index); | |
2baba250 | 842 | |
213c99ee | 843 | writeback_stat = |
3d14c5d2 | 844 | atomic_long_inc_return(&fsc->writeback_count); |
213c99ee | 845 | if (writeback_stat > CONGESTION_ON_THRESH( |
3d14c5d2 YS |
846 | fsc->mount_options->congestion_kb)) { |
847 | set_bdi_congested(&fsc->backing_dev_info, | |
213c99ee | 848 | BLK_RW_ASYNC); |
2baba250 YS |
849 | } |
850 | ||
1d3576fd SW |
851 | set_page_writeback(page); |
852 | req->r_pages[locked_pages] = page; | |
853 | locked_pages++; | |
854 | next = page->index + 1; | |
855 | } | |
856 | ||
857 | /* did we get anything? */ | |
858 | if (!locked_pages) | |
859 | goto release_pvec_pages; | |
860 | if (i) { | |
861 | int j; | |
862 | BUG_ON(!locked_pages || first < 0); | |
863 | ||
864 | if (pvec_pages && i == pvec_pages && | |
865 | locked_pages < max_pages) { | |
866 | dout("reached end pvec, trying for more\n"); | |
867 | pagevec_reinit(&pvec); | |
868 | goto get_more_pages; | |
869 | } | |
870 | ||
871 | /* shift unused pages over in the pvec... we | |
872 | * will need to release them below. */ | |
873 | for (j = i; j < pvec_pages; j++) { | |
874 | dout(" pvec leftover page %p\n", | |
875 | pvec.pages[j]); | |
876 | pvec.pages[j-i+first] = pvec.pages[j]; | |
877 | } | |
878 | pvec.nr -= i-first; | |
879 | } | |
880 | ||
881 | /* submit the write */ | |
882 | offset = req->r_pages[0]->index << PAGE_CACHE_SHIFT; | |
883 | len = min((snap_size ? snap_size : i_size_read(inode)) - offset, | |
884 | (u64)locked_pages << PAGE_CACHE_SHIFT); | |
885 | dout("writepages got %d pages at %llu~%llu\n", | |
886 | locked_pages, offset, len); | |
887 | ||
888 | /* revise final length, page count */ | |
889 | req->r_num_pages = locked_pages; | |
890 | reqhead = req->r_request->front.iov_base; | |
891 | op = (void *)(reqhead + 1); | |
892 | op->extent.length = cpu_to_le64(len); | |
893 | op->payload_len = cpu_to_le32(len); | |
894 | req->r_request->hdr.data_len = cpu_to_le32(len); | |
895 | ||
9d6fcb08 SW |
896 | rc = ceph_osdc_start_request(&fsc->client->osdc, req, true); |
897 | BUG_ON(rc); | |
1d3576fd SW |
898 | req = NULL; |
899 | ||
900 | /* continue? */ | |
901 | index = next; | |
902 | wbc->nr_to_write -= locked_pages; | |
903 | if (wbc->nr_to_write <= 0) | |
904 | done = 1; | |
905 | ||
906 | release_pvec_pages: | |
907 | dout("pagevec_release on %d pages (%p)\n", (int)pvec.nr, | |
908 | pvec.nr ? pvec.pages[0] : NULL); | |
909 | pagevec_release(&pvec); | |
910 | ||
911 | if (locked_pages && !done) | |
912 | goto retry; | |
913 | } | |
914 | ||
915 | if (should_loop && !done) { | |
916 | /* more to do; loop back to beginning of file */ | |
917 | dout("writepages looping back to beginning of file\n"); | |
918 | should_loop = 0; | |
919 | index = 0; | |
920 | goto retry; | |
921 | } | |
922 | ||
923 | if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0)) | |
924 | mapping->writeback_index = index; | |
925 | ||
926 | out: | |
927 | if (req) | |
928 | ceph_osdc_put_request(req); | |
1d3576fd SW |
929 | ceph_put_snap_context(snapc); |
930 | dout("writepages done, rc = %d\n", rc); | |
1d3576fd SW |
931 | return rc; |
932 | } | |
933 | ||
934 | ||
935 | ||
936 | /* | |
937 | * See if a given @snapc is either writeable, or already written. | |
938 | */ | |
939 | static int context_is_writeable_or_written(struct inode *inode, | |
940 | struct ceph_snap_context *snapc) | |
941 | { | |
942 | struct ceph_snap_context *oldest = get_oldest_context(inode, NULL); | |
6298a337 SW |
943 | int ret = !oldest || snapc->seq <= oldest->seq; |
944 | ||
945 | ceph_put_snap_context(oldest); | |
946 | return ret; | |
1d3576fd SW |
947 | } |
948 | ||
949 | /* | |
950 | * We are only allowed to write into/dirty the page if the page is | |
951 | * clean, or already dirty within the same snap context. | |
8f883c24 SW |
952 | * |
953 | * called with page locked. | |
954 | * return success with page locked, | |
955 | * or any failure (incl -EAGAIN) with page unlocked. | |
1d3576fd | 956 | */ |
4af6b225 YS |
957 | static int ceph_update_writeable_page(struct file *file, |
958 | loff_t pos, unsigned len, | |
959 | struct page *page) | |
1d3576fd SW |
960 | { |
961 | struct inode *inode = file->f_dentry->d_inode; | |
962 | struct ceph_inode_info *ci = ceph_inode(inode); | |
3d14c5d2 | 963 | struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc; |
1d3576fd SW |
964 | loff_t page_off = pos & PAGE_CACHE_MASK; |
965 | int pos_in_page = pos & ~PAGE_CACHE_MASK; | |
966 | int end_in_page = pos_in_page + len; | |
967 | loff_t i_size; | |
1d3576fd | 968 | int r; |
80e755fe | 969 | struct ceph_snap_context *snapc, *oldest; |
1d3576fd | 970 | |
1d3576fd SW |
971 | retry_locked: |
972 | /* writepages currently holds page lock, but if we change that later, */ | |
973 | wait_on_page_writeback(page); | |
974 | ||
975 | /* check snap context */ | |
976 | BUG_ON(!ci->i_snap_realm); | |
977 | down_read(&mdsc->snap_rwsem); | |
978 | BUG_ON(!ci->i_snap_realm->cached_context); | |
80e755fe SW |
979 | snapc = (void *)page->private; |
980 | if (snapc && snapc != ci->i_head_snapc) { | |
1d3576fd SW |
981 | /* |
982 | * this page is already dirty in another (older) snap | |
983 | * context! is it writeable now? | |
984 | */ | |
80e755fe | 985 | oldest = get_oldest_context(inode, NULL); |
1d3576fd SW |
986 | up_read(&mdsc->snap_rwsem); |
987 | ||
80e755fe | 988 | if (snapc->seq > oldest->seq) { |
6298a337 | 989 | ceph_put_snap_context(oldest); |
1d3576fd | 990 | dout(" page %p snapc %p not current or oldest\n", |
6298a337 | 991 | page, snapc); |
1d3576fd SW |
992 | /* |
993 | * queue for writeback, and wait for snapc to | |
994 | * be writeable or written | |
995 | */ | |
6298a337 | 996 | snapc = ceph_get_snap_context(snapc); |
1d3576fd | 997 | unlock_page(page); |
3c6f6b79 | 998 | ceph_queue_writeback(inode); |
8f883c24 | 999 | r = wait_event_interruptible(ci->i_cap_wq, |
1d3576fd SW |
1000 | context_is_writeable_or_written(inode, snapc)); |
1001 | ceph_put_snap_context(snapc); | |
8f883c24 SW |
1002 | if (r == -ERESTARTSYS) |
1003 | return r; | |
4af6b225 | 1004 | return -EAGAIN; |
1d3576fd | 1005 | } |
6298a337 | 1006 | ceph_put_snap_context(oldest); |
1d3576fd SW |
1007 | |
1008 | /* yay, writeable, do it now (without dropping page lock) */ | |
1009 | dout(" page %p snapc %p not current, but oldest\n", | |
1010 | page, snapc); | |
1011 | if (!clear_page_dirty_for_io(page)) | |
1012 | goto retry_locked; | |
1013 | r = writepage_nounlock(page, NULL); | |
1014 | if (r < 0) | |
1015 | goto fail_nosnap; | |
1016 | goto retry_locked; | |
1017 | } | |
1018 | ||
1019 | if (PageUptodate(page)) { | |
1020 | dout(" page %p already uptodate\n", page); | |
1021 | return 0; | |
1022 | } | |
1023 | ||
1024 | /* full page? */ | |
1025 | if (pos_in_page == 0 && len == PAGE_CACHE_SIZE) | |
1026 | return 0; | |
1027 | ||
1028 | /* past end of file? */ | |
1029 | i_size = inode->i_size; /* caller holds i_mutex */ | |
1030 | ||
1031 | if (i_size + len > inode->i_sb->s_maxbytes) { | |
1032 | /* file is too big */ | |
1033 | r = -EINVAL; | |
1034 | goto fail; | |
1035 | } | |
1036 | ||
1037 | if (page_off >= i_size || | |
1038 | (pos_in_page == 0 && (pos+len) >= i_size && | |
1039 | end_in_page - pos_in_page != PAGE_CACHE_SIZE)) { | |
1040 | dout(" zeroing %p 0 - %d and %d - %d\n", | |
1041 | page, pos_in_page, end_in_page, (int)PAGE_CACHE_SIZE); | |
1042 | zero_user_segments(page, | |
1043 | 0, pos_in_page, | |
1044 | end_in_page, PAGE_CACHE_SIZE); | |
1045 | return 0; | |
1046 | } | |
1047 | ||
1048 | /* we need to read it. */ | |
1049 | up_read(&mdsc->snap_rwsem); | |
1050 | r = readpage_nounlock(file, page); | |
1051 | if (r < 0) | |
1052 | goto fail_nosnap; | |
1053 | goto retry_locked; | |
1054 | ||
1055 | fail: | |
1056 | up_read(&mdsc->snap_rwsem); | |
1057 | fail_nosnap: | |
1058 | unlock_page(page); | |
1059 | return r; | |
1060 | } | |
1061 | ||
4af6b225 YS |
1062 | /* |
1063 | * We are only allowed to write into/dirty the page if the page is | |
1064 | * clean, or already dirty within the same snap context. | |
1065 | */ | |
1066 | static int ceph_write_begin(struct file *file, struct address_space *mapping, | |
1067 | loff_t pos, unsigned len, unsigned flags, | |
1068 | struct page **pagep, void **fsdata) | |
1069 | { | |
1070 | struct inode *inode = file->f_dentry->d_inode; | |
1071 | struct page *page; | |
1072 | pgoff_t index = pos >> PAGE_CACHE_SHIFT; | |
1073 | int r; | |
1074 | ||
1075 | do { | |
8f883c24 | 1076 | /* get a page */ |
4af6b225 YS |
1077 | page = grab_cache_page_write_begin(mapping, index, 0); |
1078 | if (!page) | |
1079 | return -ENOMEM; | |
1080 | *pagep = page; | |
1081 | ||
1082 | dout("write_begin file %p inode %p page %p %d~%d\n", file, | |
213c99ee | 1083 | inode, page, (int)pos, (int)len); |
4af6b225 YS |
1084 | |
1085 | r = ceph_update_writeable_page(file, pos, len, page); | |
1086 | } while (r == -EAGAIN); | |
1087 | ||
1088 | return r; | |
1089 | } | |
1090 | ||
1d3576fd SW |
1091 | /* |
1092 | * we don't do anything in here that simple_write_end doesn't do | |
1093 | * except adjust dirty page accounting and drop read lock on | |
1094 | * mdsc->snap_rwsem. | |
1095 | */ | |
1096 | static int ceph_write_end(struct file *file, struct address_space *mapping, | |
1097 | loff_t pos, unsigned len, unsigned copied, | |
1098 | struct page *page, void *fsdata) | |
1099 | { | |
1100 | struct inode *inode = file->f_dentry->d_inode; | |
3d14c5d2 YS |
1101 | struct ceph_fs_client *fsc = ceph_inode_to_client(inode); |
1102 | struct ceph_mds_client *mdsc = fsc->mdsc; | |
1d3576fd SW |
1103 | unsigned from = pos & (PAGE_CACHE_SIZE - 1); |
1104 | int check_cap = 0; | |
1105 | ||
1106 | dout("write_end file %p inode %p page %p %d~%d (%d)\n", file, | |
1107 | inode, page, (int)pos, (int)copied, (int)len); | |
1108 | ||
1109 | /* zero the stale part of the page if we did a short copy */ | |
1110 | if (copied < len) | |
1111 | zero_user_segment(page, from+copied, len); | |
1112 | ||
1113 | /* did file size increase? */ | |
1114 | /* (no need for i_size_read(); we caller holds i_mutex */ | |
1115 | if (pos+copied > inode->i_size) | |
1116 | check_cap = ceph_inode_set_size(inode, pos+copied); | |
1117 | ||
1118 | if (!PageUptodate(page)) | |
1119 | SetPageUptodate(page); | |
1120 | ||
1121 | set_page_dirty(page); | |
1122 | ||
1123 | unlock_page(page); | |
1124 | up_read(&mdsc->snap_rwsem); | |
1125 | page_cache_release(page); | |
1126 | ||
1127 | if (check_cap) | |
1128 | ceph_check_caps(ceph_inode(inode), CHECK_CAPS_AUTHONLY, NULL); | |
1129 | ||
1130 | return copied; | |
1131 | } | |
1132 | ||
1133 | /* | |
1134 | * we set .direct_IO to indicate direct io is supported, but since we | |
1135 | * intercept O_DIRECT reads and writes early, this function should | |
1136 | * never get called. | |
1137 | */ | |
1138 | static ssize_t ceph_direct_io(int rw, struct kiocb *iocb, | |
1139 | const struct iovec *iov, | |
1140 | loff_t pos, unsigned long nr_segs) | |
1141 | { | |
1142 | WARN_ON(1); | |
1143 | return -EINVAL; | |
1144 | } | |
1145 | ||
1146 | const struct address_space_operations ceph_aops = { | |
1147 | .readpage = ceph_readpage, | |
1148 | .readpages = ceph_readpages, | |
1149 | .writepage = ceph_writepage, | |
1150 | .writepages = ceph_writepages_start, | |
1151 | .write_begin = ceph_write_begin, | |
1152 | .write_end = ceph_write_end, | |
1153 | .set_page_dirty = ceph_set_page_dirty, | |
1154 | .invalidatepage = ceph_invalidatepage, | |
1155 | .releasepage = ceph_releasepage, | |
1156 | .direct_IO = ceph_direct_io, | |
1157 | }; | |
1158 | ||
1159 | ||
1160 | /* | |
1161 | * vm ops | |
1162 | */ | |
1163 | ||
1164 | /* | |
1165 | * Reuse write_begin here for simplicity. | |
1166 | */ | |
1167 | static int ceph_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) | |
1168 | { | |
1169 | struct inode *inode = vma->vm_file->f_dentry->d_inode; | |
1170 | struct page *page = vmf->page; | |
3d14c5d2 | 1171 | struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc; |
1d3576fd SW |
1172 | loff_t off = page->index << PAGE_CACHE_SHIFT; |
1173 | loff_t size, len; | |
1d3576fd SW |
1174 | int ret; |
1175 | ||
1176 | size = i_size_read(inode); | |
1177 | if (off + PAGE_CACHE_SIZE <= size) | |
1178 | len = PAGE_CACHE_SIZE; | |
1179 | else | |
1180 | len = size & ~PAGE_CACHE_MASK; | |
1181 | ||
1182 | dout("page_mkwrite %p %llu~%llu page %p idx %lu\n", inode, | |
1183 | off, len, page, page->index); | |
4af6b225 YS |
1184 | |
1185 | lock_page(page); | |
1186 | ||
1187 | ret = VM_FAULT_NOPAGE; | |
1188 | if ((off > size) || | |
1189 | (page->mapping != inode->i_mapping)) | |
1190 | goto out; | |
1191 | ||
1192 | ret = ceph_update_writeable_page(vma->vm_file, off, len, page); | |
1193 | if (ret == 0) { | |
1194 | /* success. we'll keep the page locked. */ | |
1d3576fd SW |
1195 | set_page_dirty(page); |
1196 | up_read(&mdsc->snap_rwsem); | |
1d3576fd SW |
1197 | ret = VM_FAULT_LOCKED; |
1198 | } else { | |
4af6b225 YS |
1199 | if (ret == -ENOMEM) |
1200 | ret = VM_FAULT_OOM; | |
1201 | else | |
1202 | ret = VM_FAULT_SIGBUS; | |
1d3576fd | 1203 | } |
4af6b225 | 1204 | out: |
1d3576fd | 1205 | dout("page_mkwrite %p %llu~%llu = %d\n", inode, off, len, ret); |
4af6b225 YS |
1206 | if (ret != VM_FAULT_LOCKED) |
1207 | unlock_page(page); | |
1d3576fd SW |
1208 | return ret; |
1209 | } | |
1210 | ||
1211 | static struct vm_operations_struct ceph_vmops = { | |
1212 | .fault = filemap_fault, | |
1213 | .page_mkwrite = ceph_page_mkwrite, | |
1214 | }; | |
1215 | ||
1216 | int ceph_mmap(struct file *file, struct vm_area_struct *vma) | |
1217 | { | |
1218 | struct address_space *mapping = file->f_mapping; | |
1219 | ||
1220 | if (!mapping->a_ops->readpage) | |
1221 | return -ENOEXEC; | |
1222 | file_accessed(file); | |
1223 | vma->vm_ops = &ceph_vmops; | |
1224 | vma->vm_flags |= VM_CAN_NONLINEAR; | |
1225 | return 0; | |
1226 | } |