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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 | 13 | #include "mds_client.h" |
99ccbd22 | 14 | #include "cache.h" |
3d14c5d2 | 15 | #include <linux/ceph/osd_client.h> |
1d3576fd SW |
16 | |
17 | /* | |
18 | * Ceph address space ops. | |
19 | * | |
20 | * There are a few funny things going on here. | |
21 | * | |
22 | * The page->private field is used to reference a struct | |
23 | * ceph_snap_context for _every_ dirty page. This indicates which | |
24 | * snapshot the page was logically dirtied in, and thus which snap | |
25 | * context needs to be associated with the osd write during writeback. | |
26 | * | |
27 | * Similarly, struct ceph_inode_info maintains a set of counters to | |
25985edc | 28 | * count dirty pages on the inode. In the absence of snapshots, |
1d3576fd SW |
29 | * i_wrbuffer_ref == i_wrbuffer_ref_head == the dirty page count. |
30 | * | |
31 | * When a snapshot is taken (that is, when the client receives | |
32 | * notification that a snapshot was taken), each inode with caps and | |
33 | * with dirty pages (dirty pages implies there is a cap) gets a new | |
34 | * ceph_cap_snap in the i_cap_snaps list (which is sorted in ascending | |
35 | * order, new snaps go to the tail). The i_wrbuffer_ref_head count is | |
36 | * moved to capsnap->dirty. (Unless a sync write is currently in | |
37 | * progress. In that case, the capsnap is said to be "pending", new | |
38 | * writes cannot start, and the capsnap isn't "finalized" until the | |
39 | * write completes (or fails) and a final size/mtime for the inode for | |
40 | * that snap can be settled upon.) i_wrbuffer_ref_head is reset to 0. | |
41 | * | |
42 | * On writeback, we must submit writes to the osd IN SNAP ORDER. So, | |
43 | * we look for the first capsnap in i_cap_snaps and write out pages in | |
44 | * that snap context _only_. Then we move on to the next capsnap, | |
45 | * eventually reaching the "live" or "head" context (i.e., pages that | |
46 | * are not yet snapped) and are writing the most recently dirtied | |
47 | * pages. | |
48 | * | |
49 | * Invalidate and so forth must take care to ensure the dirty page | |
50 | * accounting is preserved. | |
51 | */ | |
52 | ||
2baba250 YS |
53 | #define CONGESTION_ON_THRESH(congestion_kb) (congestion_kb >> (PAGE_SHIFT-10)) |
54 | #define CONGESTION_OFF_THRESH(congestion_kb) \ | |
55 | (CONGESTION_ON_THRESH(congestion_kb) - \ | |
56 | (CONGESTION_ON_THRESH(congestion_kb) >> 2)) | |
57 | ||
61600ef8 YZ |
58 | static inline struct ceph_snap_context *page_snap_context(struct page *page) |
59 | { | |
60 | if (PagePrivate(page)) | |
61 | return (void *)page->private; | |
62 | return NULL; | |
63 | } | |
1d3576fd SW |
64 | |
65 | /* | |
66 | * Dirty a page. Optimistically adjust accounting, on the assumption | |
67 | * that we won't race with invalidate. If we do, readjust. | |
68 | */ | |
69 | static int ceph_set_page_dirty(struct page *page) | |
70 | { | |
71 | struct address_space *mapping = page->mapping; | |
72 | struct inode *inode; | |
73 | struct ceph_inode_info *ci; | |
1d3576fd | 74 | struct ceph_snap_context *snapc; |
7d6e1f54 | 75 | int ret; |
1d3576fd SW |
76 | |
77 | if (unlikely(!mapping)) | |
78 | return !TestSetPageDirty(page); | |
79 | ||
7d6e1f54 | 80 | if (PageDirty(page)) { |
1d3576fd SW |
81 | dout("%p set_page_dirty %p idx %lu -- already dirty\n", |
82 | mapping->host, page, page->index); | |
7d6e1f54 | 83 | BUG_ON(!PagePrivate(page)); |
1d3576fd SW |
84 | return 0; |
85 | } | |
86 | ||
87 | inode = mapping->host; | |
88 | ci = ceph_inode(inode); | |
89 | ||
90 | /* | |
91 | * Note that we're grabbing a snapc ref here without holding | |
92 | * any locks! | |
93 | */ | |
94 | snapc = ceph_get_snap_context(ci->i_snap_realm->cached_context); | |
95 | ||
96 | /* dirty the head */ | |
be655596 | 97 | spin_lock(&ci->i_ceph_lock); |
7d8cb26d | 98 | if (ci->i_head_snapc == NULL) |
1d3576fd SW |
99 | ci->i_head_snapc = ceph_get_snap_context(snapc); |
100 | ++ci->i_wrbuffer_ref_head; | |
101 | if (ci->i_wrbuffer_ref == 0) | |
0444d76a | 102 | ihold(inode); |
1d3576fd SW |
103 | ++ci->i_wrbuffer_ref; |
104 | dout("%p set_page_dirty %p idx %lu head %d/%d -> %d/%d " | |
105 | "snapc %p seq %lld (%d snaps)\n", | |
106 | mapping->host, page, page->index, | |
107 | ci->i_wrbuffer_ref-1, ci->i_wrbuffer_ref_head-1, | |
108 | ci->i_wrbuffer_ref, ci->i_wrbuffer_ref_head, | |
109 | snapc, snapc->seq, snapc->num_snaps); | |
be655596 | 110 | spin_unlock(&ci->i_ceph_lock); |
1d3576fd | 111 | |
7d6e1f54 SZ |
112 | /* |
113 | * Reference snap context in page->private. Also set | |
114 | * PagePrivate so that we get invalidatepage callback. | |
115 | */ | |
116 | BUG_ON(PagePrivate(page)); | |
117 | page->private = (unsigned long)snapc; | |
118 | SetPagePrivate(page); | |
1d3576fd | 119 | |
7d6e1f54 SZ |
120 | ret = __set_page_dirty_nobuffers(page); |
121 | WARN_ON(!PageLocked(page)); | |
122 | WARN_ON(!page->mapping); | |
1d3576fd | 123 | |
7d6e1f54 | 124 | return ret; |
1d3576fd SW |
125 | } |
126 | ||
127 | /* | |
128 | * If we are truncating the full page (i.e. offset == 0), adjust the | |
129 | * dirty page counters appropriately. Only called if there is private | |
130 | * data on the page. | |
131 | */ | |
d47992f8 LC |
132 | static void ceph_invalidatepage(struct page *page, unsigned int offset, |
133 | unsigned int length) | |
1d3576fd | 134 | { |
4ce1e9ad | 135 | struct inode *inode; |
1d3576fd | 136 | struct ceph_inode_info *ci; |
61600ef8 | 137 | struct ceph_snap_context *snapc = page_snap_context(page); |
1d3576fd | 138 | |
4ce1e9ad | 139 | inode = page->mapping->host; |
b150f5c1 MT |
140 | ci = ceph_inode(inode); |
141 | ||
142 | if (offset != 0 || length != PAGE_CACHE_SIZE) { | |
143 | dout("%p invalidatepage %p idx %lu partial dirty page %u~%u\n", | |
144 | inode, page, page->index, offset, length); | |
145 | return; | |
146 | } | |
4ce1e9ad | 147 | |
99ccbd22 MT |
148 | ceph_invalidate_fscache_page(inode, page); |
149 | ||
150 | if (!PagePrivate(page)) | |
151 | return; | |
152 | ||
1d3576fd SW |
153 | /* |
154 | * We can get non-dirty pages here due to races between | |
155 | * set_page_dirty and truncate_complete_page; just spit out a | |
156 | * warning, in case we end up with accounting problems later. | |
157 | */ | |
158 | if (!PageDirty(page)) | |
159 | pr_err("%p invalidatepage %p page not dirty\n", inode, page); | |
160 | ||
b150f5c1 | 161 | ClearPageChecked(page); |
1d3576fd | 162 | |
b150f5c1 MT |
163 | dout("%p invalidatepage %p idx %lu full dirty page\n", |
164 | inode, page, page->index); | |
165 | ||
166 | ceph_put_wrbuffer_cap_refs(ci, 1, snapc); | |
167 | ceph_put_snap_context(snapc); | |
168 | page->private = 0; | |
169 | ClearPagePrivate(page); | |
1d3576fd SW |
170 | } |
171 | ||
1d3576fd SW |
172 | static int ceph_releasepage(struct page *page, gfp_t g) |
173 | { | |
174 | struct inode *inode = page->mapping ? page->mapping->host : NULL; | |
175 | dout("%p releasepage %p idx %lu\n", inode, page, page->index); | |
176 | WARN_ON(PageDirty(page)); | |
99ccbd22 MT |
177 | |
178 | /* Can we release the page from the cache? */ | |
179 | if (!ceph_release_fscache_page(page, g)) | |
180 | return 0; | |
181 | ||
182 | return !PagePrivate(page); | |
1d3576fd SW |
183 | } |
184 | ||
185 | /* | |
186 | * read a single page, without unlocking it. | |
187 | */ | |
188 | static int readpage_nounlock(struct file *filp, struct page *page) | |
189 | { | |
496ad9aa | 190 | struct inode *inode = file_inode(filp); |
1d3576fd | 191 | struct ceph_inode_info *ci = ceph_inode(inode); |
99ccbd22 | 192 | struct ceph_osd_client *osdc = |
3d14c5d2 | 193 | &ceph_inode_to_client(inode)->client->osdc; |
1d3576fd SW |
194 | int err = 0; |
195 | u64 len = PAGE_CACHE_SIZE; | |
196 | ||
99ccbd22 MT |
197 | err = ceph_readpage_from_fscache(inode, page); |
198 | ||
199 | if (err == 0) | |
200 | goto out; | |
201 | ||
1d3576fd SW |
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, | |
6285bc23 | 205 | (u64) page_offset(page), &len, |
1d3576fd | 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 | ||
99ccbd22 MT |
219 | if (err == 0) |
220 | ceph_readpage_to_fscache(inode, page); | |
221 | ||
1d3576fd SW |
222 | out: |
223 | return err < 0 ? err : 0; | |
224 | } | |
225 | ||
226 | static int ceph_readpage(struct file *filp, struct page *page) | |
227 | { | |
228 | int r = readpage_nounlock(filp, page); | |
229 | unlock_page(page); | |
230 | return r; | |
231 | } | |
232 | ||
233 | /* | |
7c272194 | 234 | * Finish an async read(ahead) op. |
1d3576fd | 235 | */ |
7c272194 | 236 | static void finish_read(struct ceph_osd_request *req, struct ceph_msg *msg) |
1d3576fd | 237 | { |
7c272194 | 238 | struct inode *inode = req->r_inode; |
87060c10 | 239 | struct ceph_osd_data *osd_data; |
1b83bef2 SW |
240 | int rc = req->r_result; |
241 | int bytes = le32_to_cpu(msg->hdr.data_len); | |
e0c59487 | 242 | int num_pages; |
7c272194 | 243 | int i; |
1d3576fd | 244 | |
7c272194 SW |
245 | dout("finish_read %p req %p rc %d bytes %d\n", inode, req, rc, bytes); |
246 | ||
247 | /* unlock all pages, zeroing any data we didn't read */ | |
406e2c9f | 248 | osd_data = osd_req_op_extent_osd_data(req, 0); |
87060c10 AE |
249 | BUG_ON(osd_data->type != CEPH_OSD_DATA_TYPE_PAGES); |
250 | num_pages = calc_pages_for((u64)osd_data->alignment, | |
251 | (u64)osd_data->length); | |
e0c59487 | 252 | for (i = 0; i < num_pages; i++) { |
87060c10 | 253 | struct page *page = osd_data->pages[i]; |
7c272194 SW |
254 | |
255 | if (bytes < (int)PAGE_CACHE_SIZE) { | |
256 | /* zero (remainder of) page */ | |
257 | int s = bytes < 0 ? 0 : bytes; | |
258 | zero_user_segment(page, s, PAGE_CACHE_SIZE); | |
1d3576fd | 259 | } |
7c272194 SW |
260 | dout("finish_read %p uptodate %p idx %lu\n", inode, page, |
261 | page->index); | |
262 | flush_dcache_page(page); | |
263 | SetPageUptodate(page); | |
99ccbd22 | 264 | ceph_readpage_to_fscache(inode, page); |
7c272194 SW |
265 | unlock_page(page); |
266 | page_cache_release(page); | |
0fff87ec | 267 | bytes -= PAGE_CACHE_SIZE; |
1d3576fd | 268 | } |
87060c10 | 269 | kfree(osd_data->pages); |
1d3576fd SW |
270 | } |
271 | ||
8884d53d DZ |
272 | static void ceph_unlock_page_vector(struct page **pages, int num_pages) |
273 | { | |
274 | int i; | |
275 | ||
276 | for (i = 0; i < num_pages; i++) | |
277 | unlock_page(pages[i]); | |
278 | } | |
279 | ||
1d3576fd | 280 | /* |
7c272194 SW |
281 | * start an async read(ahead) operation. return nr_pages we submitted |
282 | * a read for on success, or negative error code. | |
1d3576fd | 283 | */ |
0d66a487 | 284 | static int start_read(struct inode *inode, struct list_head *page_list, int max) |
1d3576fd | 285 | { |
3d14c5d2 YS |
286 | struct ceph_osd_client *osdc = |
287 | &ceph_inode_to_client(inode)->client->osdc; | |
7c272194 SW |
288 | struct ceph_inode_info *ci = ceph_inode(inode); |
289 | struct page *page = list_entry(page_list->prev, struct page, lru); | |
acead002 | 290 | struct ceph_vino vino; |
7c272194 SW |
291 | struct ceph_osd_request *req; |
292 | u64 off; | |
1d3576fd | 293 | u64 len; |
7c272194 SW |
294 | int i; |
295 | struct page **pages; | |
296 | pgoff_t next_index; | |
297 | int nr_pages = 0; | |
298 | int ret; | |
1d3576fd | 299 | |
6285bc23 | 300 | off = (u64) page_offset(page); |
1d3576fd | 301 | |
7c272194 SW |
302 | /* count pages */ |
303 | next_index = page->index; | |
304 | list_for_each_entry_reverse(page, page_list, lru) { | |
305 | if (page->index != next_index) | |
306 | break; | |
307 | nr_pages++; | |
308 | next_index++; | |
0d66a487 SW |
309 | if (max && nr_pages == max) |
310 | break; | |
7c272194 | 311 | } |
1d3576fd | 312 | len = nr_pages << PAGE_CACHE_SHIFT; |
7c272194 SW |
313 | dout("start_read %p nr_pages %d is %lld~%lld\n", inode, nr_pages, |
314 | off, len); | |
acead002 AE |
315 | vino = ceph_vino(inode); |
316 | req = ceph_osdc_new_request(osdc, &ci->i_layout, vino, off, &len, | |
79528734 | 317 | 1, CEPH_OSD_OP_READ, |
acead002 | 318 | CEPH_OSD_FLAG_READ, NULL, |
7c272194 | 319 | ci->i_truncate_seq, ci->i_truncate_size, |
acead002 | 320 | false); |
6816282d SW |
321 | if (IS_ERR(req)) |
322 | return PTR_ERR(req); | |
1d3576fd | 323 | |
7c272194 | 324 | /* build page vector */ |
cf7b7e14 | 325 | nr_pages = calc_pages_for(0, len); |
7c272194 SW |
326 | pages = kmalloc(sizeof(*pages) * nr_pages, GFP_NOFS); |
327 | ret = -ENOMEM; | |
328 | if (!pages) | |
329 | goto out; | |
330 | for (i = 0; i < nr_pages; ++i) { | |
331 | page = list_entry(page_list->prev, struct page, lru); | |
332 | BUG_ON(PageLocked(page)); | |
1d3576fd | 333 | list_del(&page->lru); |
99ccbd22 | 334 | |
7c272194 SW |
335 | dout("start_read %p adding %p idx %lu\n", inode, page, |
336 | page->index); | |
337 | if (add_to_page_cache_lru(page, &inode->i_data, page->index, | |
213c99ee | 338 | GFP_NOFS)) { |
d4d3aa38 | 339 | ceph_fscache_uncache_page(inode, page); |
1d3576fd | 340 | page_cache_release(page); |
7c272194 | 341 | dout("start_read %p add_to_page_cache failed %p\n", |
1d3576fd | 342 | inode, page); |
7c272194 SW |
343 | nr_pages = i; |
344 | goto out_pages; | |
1d3576fd | 345 | } |
7c272194 | 346 | pages[i] = page; |
1d3576fd | 347 | } |
406e2c9f | 348 | osd_req_op_extent_osd_data_pages(req, 0, pages, len, 0, false, false); |
7c272194 SW |
349 | req->r_callback = finish_read; |
350 | req->r_inode = inode; | |
351 | ||
79528734 | 352 | ceph_osdc_build_request(req, off, NULL, vino.snap, NULL); |
02ee07d3 | 353 | |
7c272194 SW |
354 | dout("start_read %p starting %p %lld~%lld\n", inode, req, off, len); |
355 | ret = ceph_osdc_start_request(osdc, req, false); | |
356 | if (ret < 0) | |
357 | goto out_pages; | |
358 | ceph_osdc_put_request(req); | |
359 | return nr_pages; | |
360 | ||
361 | out_pages: | |
8884d53d | 362 | ceph_unlock_page_vector(pages, nr_pages); |
7c272194 | 363 | ceph_release_page_vector(pages, nr_pages); |
7c272194 SW |
364 | out: |
365 | ceph_osdc_put_request(req); | |
366 | return ret; | |
367 | } | |
1d3576fd | 368 | |
7c272194 SW |
369 | |
370 | /* | |
371 | * Read multiple pages. Leave pages we don't read + unlock in page_list; | |
372 | * the caller (VM) cleans them up. | |
373 | */ | |
374 | static int ceph_readpages(struct file *file, struct address_space *mapping, | |
375 | struct list_head *page_list, unsigned nr_pages) | |
376 | { | |
496ad9aa | 377 | struct inode *inode = file_inode(file); |
0d66a487 | 378 | struct ceph_fs_client *fsc = ceph_inode_to_client(inode); |
7c272194 | 379 | int rc = 0; |
0d66a487 SW |
380 | int max = 0; |
381 | ||
99ccbd22 MT |
382 | rc = ceph_readpages_from_fscache(mapping->host, mapping, page_list, |
383 | &nr_pages); | |
384 | ||
385 | if (rc == 0) | |
386 | goto out; | |
387 | ||
0d66a487 SW |
388 | if (fsc->mount_options->rsize >= PAGE_CACHE_SIZE) |
389 | max = (fsc->mount_options->rsize + PAGE_CACHE_SIZE - 1) | |
390 | >> PAGE_SHIFT; | |
7c272194 | 391 | |
2794a82a AE |
392 | dout("readpages %p file %p nr_pages %d max %d\n", inode, |
393 | file, nr_pages, | |
0d66a487 | 394 | max); |
7c272194 | 395 | while (!list_empty(page_list)) { |
0d66a487 | 396 | rc = start_read(inode, page_list, max); |
7c272194 SW |
397 | if (rc < 0) |
398 | goto out; | |
399 | BUG_ON(rc == 0); | |
400 | } | |
1d3576fd | 401 | out: |
76be778b MT |
402 | ceph_fscache_readpages_cancel(inode, page_list); |
403 | ||
7c272194 | 404 | dout("readpages %p file %p ret %d\n", inode, file, rc); |
1d3576fd SW |
405 | return rc; |
406 | } | |
407 | ||
408 | /* | |
409 | * Get ref for the oldest snapc for an inode with dirty data... that is, the | |
410 | * only snap context we are allowed to write back. | |
1d3576fd | 411 | */ |
6298a337 SW |
412 | static struct ceph_snap_context *get_oldest_context(struct inode *inode, |
413 | u64 *snap_size) | |
1d3576fd SW |
414 | { |
415 | struct ceph_inode_info *ci = ceph_inode(inode); | |
416 | struct ceph_snap_context *snapc = NULL; | |
417 | struct ceph_cap_snap *capsnap = NULL; | |
418 | ||
be655596 | 419 | spin_lock(&ci->i_ceph_lock); |
1d3576fd SW |
420 | list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) { |
421 | dout(" cap_snap %p snapc %p has %d dirty pages\n", capsnap, | |
422 | capsnap->context, capsnap->dirty_pages); | |
423 | if (capsnap->dirty_pages) { | |
424 | snapc = ceph_get_snap_context(capsnap->context); | |
425 | if (snap_size) | |
426 | *snap_size = capsnap->size; | |
427 | break; | |
428 | } | |
429 | } | |
7d8cb26d | 430 | if (!snapc && ci->i_wrbuffer_ref_head) { |
80e755fe | 431 | snapc = ceph_get_snap_context(ci->i_head_snapc); |
1d3576fd SW |
432 | dout(" head snapc %p has %d dirty pages\n", |
433 | snapc, ci->i_wrbuffer_ref_head); | |
434 | } | |
be655596 | 435 | spin_unlock(&ci->i_ceph_lock); |
1d3576fd SW |
436 | return snapc; |
437 | } | |
438 | ||
439 | /* | |
440 | * Write a single page, but leave the page locked. | |
441 | * | |
442 | * If we get a write error, set the page error bit, but still adjust the | |
443 | * dirty page accounting (i.e., page is no longer dirty). | |
444 | */ | |
445 | static int writepage_nounlock(struct page *page, struct writeback_control *wbc) | |
446 | { | |
447 | struct inode *inode; | |
448 | struct ceph_inode_info *ci; | |
3d14c5d2 | 449 | struct ceph_fs_client *fsc; |
1d3576fd | 450 | struct ceph_osd_client *osdc; |
6298a337 | 451 | struct ceph_snap_context *snapc, *oldest; |
fc2744aa | 452 | loff_t page_off = page_offset(page); |
2baba250 | 453 | long writeback_stat; |
fc2744aa YZ |
454 | u64 truncate_size, snap_size = 0; |
455 | u32 truncate_seq; | |
456 | int err = 0, len = PAGE_CACHE_SIZE; | |
1d3576fd SW |
457 | |
458 | dout("writepage %p idx %lu\n", page, page->index); | |
459 | ||
460 | if (!page->mapping || !page->mapping->host) { | |
461 | dout("writepage %p - no mapping\n", page); | |
462 | return -EFAULT; | |
463 | } | |
464 | inode = page->mapping->host; | |
465 | ci = ceph_inode(inode); | |
3d14c5d2 YS |
466 | fsc = ceph_inode_to_client(inode); |
467 | osdc = &fsc->client->osdc; | |
1d3576fd SW |
468 | |
469 | /* verify this is a writeable snap context */ | |
61600ef8 | 470 | snapc = page_snap_context(page); |
1d3576fd SW |
471 | if (snapc == NULL) { |
472 | dout("writepage %p page %p not dirty?\n", inode, page); | |
473 | goto out; | |
474 | } | |
6298a337 SW |
475 | oldest = get_oldest_context(inode, &snap_size); |
476 | if (snapc->seq > oldest->seq) { | |
1d3576fd | 477 | dout("writepage %p page %p snapc %p not writeable - noop\n", |
61600ef8 | 478 | inode, page, snapc); |
1d3576fd SW |
479 | /* we should only noop if called by kswapd */ |
480 | WARN_ON((current->flags & PF_MEMALLOC) == 0); | |
6298a337 | 481 | ceph_put_snap_context(oldest); |
1d3576fd SW |
482 | goto out; |
483 | } | |
6298a337 | 484 | ceph_put_snap_context(oldest); |
1d3576fd | 485 | |
fc2744aa YZ |
486 | spin_lock(&ci->i_ceph_lock); |
487 | truncate_seq = ci->i_truncate_seq; | |
488 | truncate_size = ci->i_truncate_size; | |
489 | if (!snap_size) | |
490 | snap_size = i_size_read(inode); | |
491 | spin_unlock(&ci->i_ceph_lock); | |
492 | ||
1d3576fd | 493 | /* is this a partial page at end of file? */ |
fc2744aa YZ |
494 | if (page_off >= snap_size) { |
495 | dout("%p page eof %llu\n", page, snap_size); | |
496 | goto out; | |
497 | } | |
498 | if (snap_size < page_off + len) | |
499 | len = snap_size - page_off; | |
1d3576fd | 500 | |
ae00d4f3 SW |
501 | dout("writepage %p page %p index %lu on %llu~%u snapc %p\n", |
502 | inode, page, page->index, page_off, len, snapc); | |
1d3576fd | 503 | |
3d14c5d2 | 504 | writeback_stat = atomic_long_inc_return(&fsc->writeback_count); |
2baba250 | 505 | if (writeback_stat > |
3d14c5d2 YS |
506 | CONGESTION_ON_THRESH(fsc->mount_options->congestion_kb)) |
507 | set_bdi_congested(&fsc->backing_dev_info, BLK_RW_ASYNC); | |
2baba250 | 508 | |
99ccbd22 MT |
509 | ceph_readpage_to_fscache(inode, page); |
510 | ||
1d3576fd SW |
511 | set_page_writeback(page); |
512 | err = ceph_osdc_writepages(osdc, ceph_vino(inode), | |
513 | &ci->i_layout, snapc, | |
514 | page_off, len, | |
fc2744aa | 515 | truncate_seq, truncate_size, |
24808826 | 516 | &inode->i_mtime, &page, 1); |
1d3576fd SW |
517 | if (err < 0) { |
518 | dout("writepage setting page/mapping error %d %p\n", err, page); | |
519 | SetPageError(page); | |
520 | mapping_set_error(&inode->i_data, err); | |
521 | if (wbc) | |
522 | wbc->pages_skipped++; | |
523 | } else { | |
524 | dout("writepage cleaned page %p\n", page); | |
525 | err = 0; /* vfs expects us to return 0 */ | |
526 | } | |
527 | page->private = 0; | |
528 | ClearPagePrivate(page); | |
529 | end_page_writeback(page); | |
530 | ceph_put_wrbuffer_cap_refs(ci, 1, snapc); | |
6298a337 | 531 | ceph_put_snap_context(snapc); /* page's reference */ |
1d3576fd SW |
532 | out: |
533 | return err; | |
534 | } | |
535 | ||
536 | static int ceph_writepage(struct page *page, struct writeback_control *wbc) | |
537 | { | |
dbd646a8 YS |
538 | int err; |
539 | struct inode *inode = page->mapping->host; | |
540 | BUG_ON(!inode); | |
70b666c3 | 541 | ihold(inode); |
dbd646a8 | 542 | err = writepage_nounlock(page, wbc); |
1d3576fd | 543 | unlock_page(page); |
dbd646a8 | 544 | iput(inode); |
1d3576fd SW |
545 | return err; |
546 | } | |
547 | ||
548 | ||
549 | /* | |
550 | * lame release_pages helper. release_pages() isn't exported to | |
551 | * modules. | |
552 | */ | |
553 | static void ceph_release_pages(struct page **pages, int num) | |
554 | { | |
555 | struct pagevec pvec; | |
556 | int i; | |
557 | ||
558 | pagevec_init(&pvec, 0); | |
559 | for (i = 0; i < num; i++) { | |
560 | if (pagevec_add(&pvec, pages[i]) == 0) | |
561 | pagevec_release(&pvec); | |
562 | } | |
563 | pagevec_release(&pvec); | |
564 | } | |
565 | ||
1d3576fd SW |
566 | /* |
567 | * async writeback completion handler. | |
568 | * | |
569 | * If we get an error, set the mapping error bit, but not the individual | |
570 | * page error bits. | |
571 | */ | |
572 | static void writepages_finish(struct ceph_osd_request *req, | |
573 | struct ceph_msg *msg) | |
574 | { | |
575 | struct inode *inode = req->r_inode; | |
1d3576fd | 576 | struct ceph_inode_info *ci = ceph_inode(inode); |
87060c10 | 577 | struct ceph_osd_data *osd_data; |
1d3576fd | 578 | unsigned wrote; |
1d3576fd | 579 | struct page *page; |
e0c59487 | 580 | int num_pages; |
1d3576fd SW |
581 | int i; |
582 | struct ceph_snap_context *snapc = req->r_snapc; | |
583 | struct address_space *mapping = inode->i_mapping; | |
1b83bef2 | 584 | int rc = req->r_result; |
79528734 | 585 | u64 bytes = req->r_ops[0].extent.length; |
3d14c5d2 | 586 | struct ceph_fs_client *fsc = ceph_inode_to_client(inode); |
2baba250 | 587 | long writeback_stat; |
7ff899da | 588 | unsigned issued = ceph_caps_issued(ci); |
1d3576fd | 589 | |
406e2c9f | 590 | osd_data = osd_req_op_extent_osd_data(req, 0); |
87060c10 AE |
591 | BUG_ON(osd_data->type != CEPH_OSD_DATA_TYPE_PAGES); |
592 | num_pages = calc_pages_for((u64)osd_data->alignment, | |
593 | (u64)osd_data->length); | |
1d3576fd | 594 | if (rc >= 0) { |
79788c69 SW |
595 | /* |
596 | * Assume we wrote the pages we originally sent. The | |
597 | * osd might reply with fewer pages if our writeback | |
598 | * raced with a truncation and was adjusted at the osd, | |
599 | * so don't believe the reply. | |
600 | */ | |
e0c59487 | 601 | wrote = num_pages; |
1d3576fd SW |
602 | } else { |
603 | wrote = 0; | |
604 | mapping_set_error(mapping, rc); | |
605 | } | |
606 | dout("writepages_finish %p rc %d bytes %llu wrote %d (pages)\n", | |
607 | inode, rc, bytes, wrote); | |
608 | ||
609 | /* clean all pages */ | |
e0c59487 | 610 | for (i = 0; i < num_pages; i++) { |
87060c10 | 611 | page = osd_data->pages[i]; |
1d3576fd SW |
612 | BUG_ON(!page); |
613 | WARN_ON(!PageUptodate(page)); | |
614 | ||
2baba250 | 615 | writeback_stat = |
3d14c5d2 | 616 | atomic_long_dec_return(&fsc->writeback_count); |
2baba250 | 617 | if (writeback_stat < |
3d14c5d2 YS |
618 | CONGESTION_OFF_THRESH(fsc->mount_options->congestion_kb)) |
619 | clear_bdi_congested(&fsc->backing_dev_info, | |
2baba250 YS |
620 | BLK_RW_ASYNC); |
621 | ||
61600ef8 | 622 | ceph_put_snap_context(page_snap_context(page)); |
1d3576fd SW |
623 | page->private = 0; |
624 | ClearPagePrivate(page); | |
1d3576fd SW |
625 | dout("unlocking %d %p\n", i, page); |
626 | end_page_writeback(page); | |
e63dc5c7 YS |
627 | |
628 | /* | |
629 | * We lost the cache cap, need to truncate the page before | |
630 | * it is unlocked, otherwise we'd truncate it later in the | |
631 | * page truncation thread, possibly losing some data that | |
632 | * raced its way in | |
633 | */ | |
2962507c | 634 | if ((issued & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) == 0) |
e63dc5c7 YS |
635 | generic_error_remove_page(inode->i_mapping, page); |
636 | ||
1d3576fd SW |
637 | unlock_page(page); |
638 | } | |
639 | dout("%p wrote+cleaned %d pages\n", inode, wrote); | |
e0c59487 | 640 | ceph_put_wrbuffer_cap_refs(ci, num_pages, snapc); |
1d3576fd | 641 | |
87060c10 AE |
642 | ceph_release_pages(osd_data->pages, num_pages); |
643 | if (osd_data->pages_from_pool) | |
644 | mempool_free(osd_data->pages, | |
640ef79d | 645 | ceph_sb_to_client(inode->i_sb)->wb_pagevec_pool); |
1d3576fd | 646 | else |
87060c10 | 647 | kfree(osd_data->pages); |
1d3576fd SW |
648 | ceph_osdc_put_request(req); |
649 | } | |
650 | ||
1d3576fd SW |
651 | /* |
652 | * initiate async writeback | |
653 | */ | |
654 | static int ceph_writepages_start(struct address_space *mapping, | |
655 | struct writeback_control *wbc) | |
656 | { | |
657 | struct inode *inode = mapping->host; | |
1d3576fd | 658 | struct ceph_inode_info *ci = ceph_inode(inode); |
fc2744aa YZ |
659 | struct ceph_fs_client *fsc = ceph_inode_to_client(inode); |
660 | struct ceph_vino vino = ceph_vino(inode); | |
1d3576fd SW |
661 | pgoff_t index, start, end; |
662 | int range_whole = 0; | |
663 | int should_loop = 1; | |
664 | pgoff_t max_pages = 0, max_pages_ever = 0; | |
80e755fe | 665 | struct ceph_snap_context *snapc = NULL, *last_snapc = NULL, *pgsnapc; |
1d3576fd SW |
666 | struct pagevec pvec; |
667 | int done = 0; | |
668 | int rc = 0; | |
669 | unsigned wsize = 1 << inode->i_blkbits; | |
670 | struct ceph_osd_request *req = NULL; | |
671 | int do_sync; | |
fc2744aa YZ |
672 | u64 truncate_size, snap_size; |
673 | u32 truncate_seq; | |
1d3576fd SW |
674 | |
675 | /* | |
676 | * Include a 'sync' in the OSD request if this is a data | |
677 | * integrity write (e.g., O_SYNC write or fsync()), or if our | |
678 | * cap is being revoked. | |
679 | */ | |
c62988ec | 680 | if ((wbc->sync_mode == WB_SYNC_ALL) || |
681 | ceph_caps_revoking(ci, CEPH_CAP_FILE_BUFFER)) | |
1d3576fd SW |
682 | do_sync = 1; |
683 | dout("writepages_start %p dosync=%d (mode=%s)\n", | |
684 | inode, do_sync, | |
685 | wbc->sync_mode == WB_SYNC_NONE ? "NONE" : | |
686 | (wbc->sync_mode == WB_SYNC_ALL ? "ALL" : "HOLD")); | |
687 | ||
3d14c5d2 | 688 | if (fsc->mount_state == CEPH_MOUNT_SHUTDOWN) { |
1d3576fd SW |
689 | pr_warning("writepage_start %p on forced umount\n", inode); |
690 | return -EIO; /* we're in a forced umount, don't write! */ | |
691 | } | |
3d14c5d2 YS |
692 | if (fsc->mount_options->wsize && fsc->mount_options->wsize < wsize) |
693 | wsize = fsc->mount_options->wsize; | |
1d3576fd SW |
694 | if (wsize < PAGE_CACHE_SIZE) |
695 | wsize = PAGE_CACHE_SIZE; | |
696 | max_pages_ever = wsize >> PAGE_CACHE_SHIFT; | |
697 | ||
698 | pagevec_init(&pvec, 0); | |
699 | ||
1d3576fd SW |
700 | /* where to start/end? */ |
701 | if (wbc->range_cyclic) { | |
702 | start = mapping->writeback_index; /* Start from prev offset */ | |
703 | end = -1; | |
704 | dout(" cyclic, start at %lu\n", start); | |
705 | } else { | |
706 | start = wbc->range_start >> PAGE_CACHE_SHIFT; | |
707 | end = wbc->range_end >> PAGE_CACHE_SHIFT; | |
708 | if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) | |
709 | range_whole = 1; | |
710 | should_loop = 0; | |
711 | dout(" not cyclic, %lu to %lu\n", start, end); | |
712 | } | |
713 | index = start; | |
714 | ||
715 | retry: | |
716 | /* find oldest snap context with dirty data */ | |
717 | ceph_put_snap_context(snapc); | |
1ac0fc8a | 718 | snap_size = 0; |
1d3576fd SW |
719 | snapc = get_oldest_context(inode, &snap_size); |
720 | if (!snapc) { | |
721 | /* hmm, why does writepages get called when there | |
722 | is no dirty data? */ | |
723 | dout(" no snap context with dirty data?\n"); | |
724 | goto out; | |
725 | } | |
1ac0fc8a YZ |
726 | if (snap_size == 0) |
727 | snap_size = i_size_read(inode); | |
1d3576fd SW |
728 | dout(" oldest snapc is %p seq %lld (%d snaps)\n", |
729 | snapc, snapc->seq, snapc->num_snaps); | |
fc2744aa YZ |
730 | |
731 | spin_lock(&ci->i_ceph_lock); | |
732 | truncate_seq = ci->i_truncate_seq; | |
733 | truncate_size = ci->i_truncate_size; | |
734 | if (!snap_size) | |
735 | snap_size = i_size_read(inode); | |
736 | spin_unlock(&ci->i_ceph_lock); | |
737 | ||
1d3576fd SW |
738 | if (last_snapc && snapc != last_snapc) { |
739 | /* if we switched to a newer snapc, restart our scan at the | |
740 | * start of the original file range. */ | |
741 | dout(" snapc differs from last pass, restarting at %lu\n", | |
742 | index); | |
743 | index = start; | |
744 | } | |
745 | last_snapc = snapc; | |
746 | ||
747 | while (!done && index <= end) { | |
e5975c7c | 748 | int num_ops = do_sync ? 2 : 1; |
1d3576fd SW |
749 | unsigned i; |
750 | int first; | |
751 | pgoff_t next; | |
752 | int pvec_pages, locked_pages; | |
e5975c7c AE |
753 | struct page **pages = NULL; |
754 | mempool_t *pool = NULL; /* Becomes non-null if mempool used */ | |
1d3576fd SW |
755 | struct page *page; |
756 | int want; | |
757 | u64 offset, len; | |
2baba250 | 758 | long writeback_stat; |
1d3576fd SW |
759 | |
760 | next = 0; | |
761 | locked_pages = 0; | |
762 | max_pages = max_pages_ever; | |
763 | ||
764 | get_more_pages: | |
765 | first = -1; | |
766 | want = min(end - index, | |
767 | min((pgoff_t)PAGEVEC_SIZE, | |
768 | max_pages - (pgoff_t)locked_pages) - 1) | |
769 | + 1; | |
770 | pvec_pages = pagevec_lookup_tag(&pvec, mapping, &index, | |
771 | PAGECACHE_TAG_DIRTY, | |
772 | want); | |
773 | dout("pagevec_lookup_tag got %d\n", pvec_pages); | |
774 | if (!pvec_pages && !locked_pages) | |
775 | break; | |
776 | for (i = 0; i < pvec_pages && locked_pages < max_pages; i++) { | |
777 | page = pvec.pages[i]; | |
778 | dout("? %p idx %lu\n", page, page->index); | |
779 | if (locked_pages == 0) | |
780 | lock_page(page); /* first page */ | |
781 | else if (!trylock_page(page)) | |
782 | break; | |
783 | ||
784 | /* only dirty pages, or our accounting breaks */ | |
785 | if (unlikely(!PageDirty(page)) || | |
786 | unlikely(page->mapping != mapping)) { | |
787 | dout("!dirty or !mapping %p\n", page); | |
788 | unlock_page(page); | |
789 | break; | |
790 | } | |
791 | if (!wbc->range_cyclic && page->index > end) { | |
792 | dout("end of range %p\n", page); | |
793 | done = 1; | |
794 | unlock_page(page); | |
795 | break; | |
796 | } | |
797 | if (next && (page->index != next)) { | |
798 | dout("not consecutive %p\n", page); | |
799 | unlock_page(page); | |
800 | break; | |
801 | } | |
802 | if (wbc->sync_mode != WB_SYNC_NONE) { | |
803 | dout("waiting on writeback %p\n", page); | |
804 | wait_on_page_writeback(page); | |
805 | } | |
1ac0fc8a YZ |
806 | if (page_offset(page) >= snap_size) { |
807 | dout("%p page eof %llu\n", page, snap_size); | |
1d3576fd SW |
808 | done = 1; |
809 | unlock_page(page); | |
810 | break; | |
811 | } | |
812 | if (PageWriteback(page)) { | |
813 | dout("%p under writeback\n", page); | |
814 | unlock_page(page); | |
815 | break; | |
816 | } | |
817 | ||
818 | /* only if matching snap context */ | |
61600ef8 | 819 | pgsnapc = page_snap_context(page); |
80e755fe SW |
820 | if (pgsnapc->seq > snapc->seq) { |
821 | dout("page snapc %p %lld > oldest %p %lld\n", | |
822 | pgsnapc, pgsnapc->seq, snapc, snapc->seq); | |
1d3576fd SW |
823 | unlock_page(page); |
824 | if (!locked_pages) | |
825 | continue; /* keep looking for snap */ | |
826 | break; | |
827 | } | |
828 | ||
829 | if (!clear_page_dirty_for_io(page)) { | |
830 | dout("%p !clear_page_dirty_for_io\n", page); | |
831 | unlock_page(page); | |
832 | break; | |
833 | } | |
834 | ||
e5975c7c AE |
835 | /* |
836 | * We have something to write. If this is | |
837 | * the first locked page this time through, | |
838 | * allocate an osd request and a page array | |
839 | * that it will use. | |
840 | */ | |
1d3576fd | 841 | if (locked_pages == 0) { |
e5975c7c | 842 | BUG_ON(pages); |
1d3576fd | 843 | /* prepare async write request */ |
e5975c7c | 844 | offset = (u64)page_offset(page); |
1d3576fd | 845 | len = wsize; |
fc2744aa YZ |
846 | req = ceph_osdc_new_request(&fsc->client->osdc, |
847 | &ci->i_layout, vino, | |
848 | offset, &len, num_ops, | |
849 | CEPH_OSD_OP_WRITE, | |
850 | CEPH_OSD_FLAG_WRITE | | |
851 | CEPH_OSD_FLAG_ONDISK, | |
852 | snapc, truncate_seq, | |
853 | truncate_size, true); | |
6816282d SW |
854 | if (IS_ERR(req)) { |
855 | rc = PTR_ERR(req); | |
8c71897b HC |
856 | unlock_page(page); |
857 | break; | |
858 | } | |
859 | ||
88486957 AE |
860 | req->r_callback = writepages_finish; |
861 | req->r_inode = inode; | |
862 | ||
863 | max_pages = calc_pages_for(0, (u64)len); | |
fc2744aa YZ |
864 | pages = kmalloc(max_pages * sizeof (*pages), |
865 | GFP_NOFS); | |
88486957 AE |
866 | if (!pages) { |
867 | pool = fsc->wb_pagevec_pool; | |
88486957 | 868 | pages = mempool_alloc(pool, GFP_NOFS); |
e5975c7c | 869 | BUG_ON(!pages); |
88486957 | 870 | } |
1d3576fd SW |
871 | } |
872 | ||
873 | /* note position of first page in pvec */ | |
874 | if (first < 0) | |
875 | first = i; | |
876 | dout("%p will write page %p idx %lu\n", | |
877 | inode, page, page->index); | |
2baba250 | 878 | |
213c99ee | 879 | writeback_stat = |
3d14c5d2 | 880 | atomic_long_inc_return(&fsc->writeback_count); |
213c99ee | 881 | if (writeback_stat > CONGESTION_ON_THRESH( |
3d14c5d2 YS |
882 | fsc->mount_options->congestion_kb)) { |
883 | set_bdi_congested(&fsc->backing_dev_info, | |
213c99ee | 884 | BLK_RW_ASYNC); |
2baba250 YS |
885 | } |
886 | ||
1d3576fd | 887 | set_page_writeback(page); |
e5975c7c | 888 | pages[locked_pages] = page; |
1d3576fd SW |
889 | locked_pages++; |
890 | next = page->index + 1; | |
891 | } | |
892 | ||
893 | /* did we get anything? */ | |
894 | if (!locked_pages) | |
895 | goto release_pvec_pages; | |
896 | if (i) { | |
897 | int j; | |
898 | BUG_ON(!locked_pages || first < 0); | |
899 | ||
900 | if (pvec_pages && i == pvec_pages && | |
901 | locked_pages < max_pages) { | |
902 | dout("reached end pvec, trying for more\n"); | |
903 | pagevec_reinit(&pvec); | |
904 | goto get_more_pages; | |
905 | } | |
906 | ||
907 | /* shift unused pages over in the pvec... we | |
908 | * will need to release them below. */ | |
909 | for (j = i; j < pvec_pages; j++) { | |
910 | dout(" pvec leftover page %p\n", | |
911 | pvec.pages[j]); | |
912 | pvec.pages[j-i+first] = pvec.pages[j]; | |
913 | } | |
914 | pvec.nr -= i-first; | |
915 | } | |
916 | ||
e5975c7c AE |
917 | /* Format the osd request message and submit the write */ |
918 | ||
919 | offset = page_offset(pages[0]); | |
1ac0fc8a | 920 | len = min(snap_size - offset, |
1d3576fd SW |
921 | (u64)locked_pages << PAGE_CACHE_SHIFT); |
922 | dout("writepages got %d pages at %llu~%llu\n", | |
923 | locked_pages, offset, len); | |
924 | ||
406e2c9f | 925 | osd_req_op_extent_osd_data_pages(req, 0, pages, len, 0, |
a4ce40a9 | 926 | !!pool, false); |
e5975c7c AE |
927 | |
928 | pages = NULL; /* request message now owns the pages array */ | |
929 | pool = NULL; | |
930 | ||
931 | /* Update the write op length in case we changed it */ | |
932 | ||
c99d2d4a | 933 | osd_req_op_extent_update(req, 0, len); |
e5975c7c AE |
934 | |
935 | vino = ceph_vino(inode); | |
79528734 AE |
936 | ceph_osdc_build_request(req, offset, snapc, vino.snap, |
937 | &inode->i_mtime); | |
1d3576fd | 938 | |
9d6fcb08 SW |
939 | rc = ceph_osdc_start_request(&fsc->client->osdc, req, true); |
940 | BUG_ON(rc); | |
1d3576fd SW |
941 | req = NULL; |
942 | ||
943 | /* continue? */ | |
944 | index = next; | |
945 | wbc->nr_to_write -= locked_pages; | |
946 | if (wbc->nr_to_write <= 0) | |
947 | done = 1; | |
948 | ||
949 | release_pvec_pages: | |
950 | dout("pagevec_release on %d pages (%p)\n", (int)pvec.nr, | |
951 | pvec.nr ? pvec.pages[0] : NULL); | |
952 | pagevec_release(&pvec); | |
953 | ||
954 | if (locked_pages && !done) | |
955 | goto retry; | |
956 | } | |
957 | ||
958 | if (should_loop && !done) { | |
959 | /* more to do; loop back to beginning of file */ | |
960 | dout("writepages looping back to beginning of file\n"); | |
961 | should_loop = 0; | |
962 | index = 0; | |
963 | goto retry; | |
964 | } | |
965 | ||
966 | if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0)) | |
967 | mapping->writeback_index = index; | |
968 | ||
969 | out: | |
970 | if (req) | |
971 | ceph_osdc_put_request(req); | |
1d3576fd SW |
972 | ceph_put_snap_context(snapc); |
973 | dout("writepages done, rc = %d\n", rc); | |
1d3576fd SW |
974 | return rc; |
975 | } | |
976 | ||
977 | ||
978 | ||
979 | /* | |
980 | * See if a given @snapc is either writeable, or already written. | |
981 | */ | |
982 | static int context_is_writeable_or_written(struct inode *inode, | |
983 | struct ceph_snap_context *snapc) | |
984 | { | |
985 | struct ceph_snap_context *oldest = get_oldest_context(inode, NULL); | |
6298a337 SW |
986 | int ret = !oldest || snapc->seq <= oldest->seq; |
987 | ||
988 | ceph_put_snap_context(oldest); | |
989 | return ret; | |
1d3576fd SW |
990 | } |
991 | ||
992 | /* | |
993 | * We are only allowed to write into/dirty the page if the page is | |
994 | * clean, or already dirty within the same snap context. | |
8f883c24 SW |
995 | * |
996 | * called with page locked. | |
997 | * return success with page locked, | |
998 | * or any failure (incl -EAGAIN) with page unlocked. | |
1d3576fd | 999 | */ |
4af6b225 YS |
1000 | static int ceph_update_writeable_page(struct file *file, |
1001 | loff_t pos, unsigned len, | |
1002 | struct page *page) | |
1d3576fd | 1003 | { |
496ad9aa | 1004 | struct inode *inode = file_inode(file); |
1d3576fd | 1005 | struct ceph_inode_info *ci = ceph_inode(inode); |
3d14c5d2 | 1006 | struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc; |
1d3576fd SW |
1007 | loff_t page_off = pos & PAGE_CACHE_MASK; |
1008 | int pos_in_page = pos & ~PAGE_CACHE_MASK; | |
1009 | int end_in_page = pos_in_page + len; | |
1010 | loff_t i_size; | |
1d3576fd | 1011 | int r; |
80e755fe | 1012 | struct ceph_snap_context *snapc, *oldest; |
1d3576fd | 1013 | |
1d3576fd SW |
1014 | retry_locked: |
1015 | /* writepages currently holds page lock, but if we change that later, */ | |
1016 | wait_on_page_writeback(page); | |
1017 | ||
1018 | /* check snap context */ | |
1019 | BUG_ON(!ci->i_snap_realm); | |
1020 | down_read(&mdsc->snap_rwsem); | |
1021 | BUG_ON(!ci->i_snap_realm->cached_context); | |
61600ef8 | 1022 | snapc = page_snap_context(page); |
80e755fe | 1023 | if (snapc && snapc != ci->i_head_snapc) { |
1d3576fd SW |
1024 | /* |
1025 | * this page is already dirty in another (older) snap | |
1026 | * context! is it writeable now? | |
1027 | */ | |
80e755fe | 1028 | oldest = get_oldest_context(inode, NULL); |
1d3576fd SW |
1029 | up_read(&mdsc->snap_rwsem); |
1030 | ||
80e755fe | 1031 | if (snapc->seq > oldest->seq) { |
6298a337 | 1032 | ceph_put_snap_context(oldest); |
1d3576fd | 1033 | dout(" page %p snapc %p not current or oldest\n", |
6298a337 | 1034 | page, snapc); |
1d3576fd SW |
1035 | /* |
1036 | * queue for writeback, and wait for snapc to | |
1037 | * be writeable or written | |
1038 | */ | |
6298a337 | 1039 | snapc = ceph_get_snap_context(snapc); |
1d3576fd | 1040 | unlock_page(page); |
3c6f6b79 | 1041 | ceph_queue_writeback(inode); |
8f883c24 | 1042 | r = wait_event_interruptible(ci->i_cap_wq, |
1d3576fd SW |
1043 | context_is_writeable_or_written(inode, snapc)); |
1044 | ceph_put_snap_context(snapc); | |
8f883c24 SW |
1045 | if (r == -ERESTARTSYS) |
1046 | return r; | |
4af6b225 | 1047 | return -EAGAIN; |
1d3576fd | 1048 | } |
6298a337 | 1049 | ceph_put_snap_context(oldest); |
1d3576fd SW |
1050 | |
1051 | /* yay, writeable, do it now (without dropping page lock) */ | |
1052 | dout(" page %p snapc %p not current, but oldest\n", | |
1053 | page, snapc); | |
1054 | if (!clear_page_dirty_for_io(page)) | |
1055 | goto retry_locked; | |
1056 | r = writepage_nounlock(page, NULL); | |
1057 | if (r < 0) | |
1058 | goto fail_nosnap; | |
1059 | goto retry_locked; | |
1060 | } | |
1061 | ||
1062 | if (PageUptodate(page)) { | |
1063 | dout(" page %p already uptodate\n", page); | |
1064 | return 0; | |
1065 | } | |
1066 | ||
1067 | /* full page? */ | |
1068 | if (pos_in_page == 0 && len == PAGE_CACHE_SIZE) | |
1069 | return 0; | |
1070 | ||
1071 | /* past end of file? */ | |
1072 | i_size = inode->i_size; /* caller holds i_mutex */ | |
1073 | ||
1074 | if (i_size + len > inode->i_sb->s_maxbytes) { | |
1075 | /* file is too big */ | |
1076 | r = -EINVAL; | |
1077 | goto fail; | |
1078 | } | |
1079 | ||
1080 | if (page_off >= i_size || | |
1081 | (pos_in_page == 0 && (pos+len) >= i_size && | |
1082 | end_in_page - pos_in_page != PAGE_CACHE_SIZE)) { | |
1083 | dout(" zeroing %p 0 - %d and %d - %d\n", | |
1084 | page, pos_in_page, end_in_page, (int)PAGE_CACHE_SIZE); | |
1085 | zero_user_segments(page, | |
1086 | 0, pos_in_page, | |
1087 | end_in_page, PAGE_CACHE_SIZE); | |
1088 | return 0; | |
1089 | } | |
1090 | ||
1091 | /* we need to read it. */ | |
1092 | up_read(&mdsc->snap_rwsem); | |
1093 | r = readpage_nounlock(file, page); | |
1094 | if (r < 0) | |
1095 | goto fail_nosnap; | |
1096 | goto retry_locked; | |
1097 | ||
1098 | fail: | |
1099 | up_read(&mdsc->snap_rwsem); | |
1100 | fail_nosnap: | |
1101 | unlock_page(page); | |
1102 | return r; | |
1103 | } | |
1104 | ||
4af6b225 YS |
1105 | /* |
1106 | * We are only allowed to write into/dirty the page if the page is | |
1107 | * clean, or already dirty within the same snap context. | |
1108 | */ | |
1109 | static int ceph_write_begin(struct file *file, struct address_space *mapping, | |
1110 | loff_t pos, unsigned len, unsigned flags, | |
1111 | struct page **pagep, void **fsdata) | |
1112 | { | |
496ad9aa | 1113 | struct inode *inode = file_inode(file); |
4af6b225 YS |
1114 | struct page *page; |
1115 | pgoff_t index = pos >> PAGE_CACHE_SHIFT; | |
7971bd92 | 1116 | int r; |
4af6b225 YS |
1117 | |
1118 | do { | |
8f883c24 | 1119 | /* get a page */ |
4af6b225 | 1120 | page = grab_cache_page_write_begin(mapping, index, 0); |
7971bd92 SW |
1121 | if (!page) |
1122 | return -ENOMEM; | |
1123 | *pagep = page; | |
4af6b225 YS |
1124 | |
1125 | dout("write_begin file %p inode %p page %p %d~%d\n", file, | |
213c99ee | 1126 | inode, page, (int)pos, (int)len); |
4af6b225 YS |
1127 | |
1128 | r = ceph_update_writeable_page(file, pos, len, page); | |
1129 | } while (r == -EAGAIN); | |
1130 | ||
1131 | return r; | |
1132 | } | |
1133 | ||
1d3576fd SW |
1134 | /* |
1135 | * we don't do anything in here that simple_write_end doesn't do | |
1136 | * except adjust dirty page accounting and drop read lock on | |
1137 | * mdsc->snap_rwsem. | |
1138 | */ | |
1139 | static int ceph_write_end(struct file *file, struct address_space *mapping, | |
1140 | loff_t pos, unsigned len, unsigned copied, | |
1141 | struct page *page, void *fsdata) | |
1142 | { | |
496ad9aa | 1143 | struct inode *inode = file_inode(file); |
3d14c5d2 YS |
1144 | struct ceph_fs_client *fsc = ceph_inode_to_client(inode); |
1145 | struct ceph_mds_client *mdsc = fsc->mdsc; | |
1d3576fd SW |
1146 | unsigned from = pos & (PAGE_CACHE_SIZE - 1); |
1147 | int check_cap = 0; | |
1148 | ||
1149 | dout("write_end file %p inode %p page %p %d~%d (%d)\n", file, | |
1150 | inode, page, (int)pos, (int)copied, (int)len); | |
1151 | ||
1152 | /* zero the stale part of the page if we did a short copy */ | |
1153 | if (copied < len) | |
1154 | zero_user_segment(page, from+copied, len); | |
1155 | ||
1156 | /* did file size increase? */ | |
1157 | /* (no need for i_size_read(); we caller holds i_mutex */ | |
1158 | if (pos+copied > inode->i_size) | |
1159 | check_cap = ceph_inode_set_size(inode, pos+copied); | |
1160 | ||
1161 | if (!PageUptodate(page)) | |
1162 | SetPageUptodate(page); | |
1163 | ||
1164 | set_page_dirty(page); | |
1165 | ||
1166 | unlock_page(page); | |
1167 | up_read(&mdsc->snap_rwsem); | |
1168 | page_cache_release(page); | |
1169 | ||
1170 | if (check_cap) | |
1171 | ceph_check_caps(ceph_inode(inode), CHECK_CAPS_AUTHONLY, NULL); | |
1172 | ||
1173 | return copied; | |
1174 | } | |
1175 | ||
1176 | /* | |
1177 | * we set .direct_IO to indicate direct io is supported, but since we | |
1178 | * intercept O_DIRECT reads and writes early, this function should | |
1179 | * never get called. | |
1180 | */ | |
1181 | static ssize_t ceph_direct_io(int rw, struct kiocb *iocb, | |
1182 | const struct iovec *iov, | |
1183 | loff_t pos, unsigned long nr_segs) | |
1184 | { | |
1185 | WARN_ON(1); | |
1186 | return -EINVAL; | |
1187 | } | |
1188 | ||
1189 | const struct address_space_operations ceph_aops = { | |
1190 | .readpage = ceph_readpage, | |
1191 | .readpages = ceph_readpages, | |
1192 | .writepage = ceph_writepage, | |
1193 | .writepages = ceph_writepages_start, | |
1194 | .write_begin = ceph_write_begin, | |
1195 | .write_end = ceph_write_end, | |
1196 | .set_page_dirty = ceph_set_page_dirty, | |
1197 | .invalidatepage = ceph_invalidatepage, | |
1198 | .releasepage = ceph_releasepage, | |
1199 | .direct_IO = ceph_direct_io, | |
1200 | }; | |
1201 | ||
1202 | ||
1203 | /* | |
1204 | * vm ops | |
1205 | */ | |
1206 | ||
1207 | /* | |
1208 | * Reuse write_begin here for simplicity. | |
1209 | */ | |
1210 | static int ceph_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) | |
1211 | { | |
496ad9aa | 1212 | struct inode *inode = file_inode(vma->vm_file); |
1d3576fd | 1213 | struct page *page = vmf->page; |
3d14c5d2 | 1214 | struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc; |
6285bc23 | 1215 | loff_t off = page_offset(page); |
1d3576fd | 1216 | loff_t size, len; |
1d3576fd SW |
1217 | int ret; |
1218 | ||
3ca9c3bd JK |
1219 | /* Update time before taking page lock */ |
1220 | file_update_time(vma->vm_file); | |
1221 | ||
1d3576fd SW |
1222 | size = i_size_read(inode); |
1223 | if (off + PAGE_CACHE_SIZE <= size) | |
1224 | len = PAGE_CACHE_SIZE; | |
1225 | else | |
1226 | len = size & ~PAGE_CACHE_MASK; | |
1227 | ||
1228 | dout("page_mkwrite %p %llu~%llu page %p idx %lu\n", inode, | |
1229 | off, len, page, page->index); | |
4af6b225 YS |
1230 | |
1231 | lock_page(page); | |
1232 | ||
1233 | ret = VM_FAULT_NOPAGE; | |
1234 | if ((off > size) || | |
1235 | (page->mapping != inode->i_mapping)) | |
1236 | goto out; | |
1237 | ||
1238 | ret = ceph_update_writeable_page(vma->vm_file, off, len, page); | |
1239 | if (ret == 0) { | |
1240 | /* success. we'll keep the page locked. */ | |
1d3576fd SW |
1241 | set_page_dirty(page); |
1242 | up_read(&mdsc->snap_rwsem); | |
1d3576fd SW |
1243 | ret = VM_FAULT_LOCKED; |
1244 | } else { | |
4af6b225 YS |
1245 | if (ret == -ENOMEM) |
1246 | ret = VM_FAULT_OOM; | |
1247 | else | |
1248 | ret = VM_FAULT_SIGBUS; | |
1d3576fd | 1249 | } |
4af6b225 | 1250 | out: |
1d3576fd | 1251 | dout("page_mkwrite %p %llu~%llu = %d\n", inode, off, len, ret); |
4af6b225 YS |
1252 | if (ret != VM_FAULT_LOCKED) |
1253 | unlock_page(page); | |
1d3576fd SW |
1254 | return ret; |
1255 | } | |
1256 | ||
1257 | static struct vm_operations_struct ceph_vmops = { | |
1258 | .fault = filemap_fault, | |
1259 | .page_mkwrite = ceph_page_mkwrite, | |
0b173bc4 | 1260 | .remap_pages = generic_file_remap_pages, |
1d3576fd SW |
1261 | }; |
1262 | ||
1263 | int ceph_mmap(struct file *file, struct vm_area_struct *vma) | |
1264 | { | |
1265 | struct address_space *mapping = file->f_mapping; | |
1266 | ||
1267 | if (!mapping->a_ops->readpage) | |
1268 | return -ENOEXEC; | |
1269 | file_accessed(file); | |
1270 | vma->vm_ops = &ceph_vmops; | |
1d3576fd SW |
1271 | return 0; |
1272 | } |