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 | ||
61600ef8 YZ |
57 | static inline struct ceph_snap_context *page_snap_context(struct page *page) |
58 | { | |
59 | if (PagePrivate(page)) | |
60 | return (void *)page->private; | |
61 | return NULL; | |
62 | } | |
1d3576fd SW |
63 | |
64 | /* | |
65 | * Dirty a page. Optimistically adjust accounting, on the assumption | |
66 | * that we won't race with invalidate. If we do, readjust. | |
67 | */ | |
68 | static int ceph_set_page_dirty(struct page *page) | |
69 | { | |
70 | struct address_space *mapping = page->mapping; | |
71 | struct inode *inode; | |
72 | struct ceph_inode_info *ci; | |
73 | int undo = 0; | |
74 | struct ceph_snap_context *snapc; | |
75 | ||
76 | if (unlikely(!mapping)) | |
77 | return !TestSetPageDirty(page); | |
78 | ||
79 | if (TestSetPageDirty(page)) { | |
80 | dout("%p set_page_dirty %p idx %lu -- already dirty\n", | |
81 | mapping->host, page, page->index); | |
82 | return 0; | |
83 | } | |
84 | ||
85 | inode = mapping->host; | |
86 | ci = ceph_inode(inode); | |
87 | ||
88 | /* | |
89 | * Note that we're grabbing a snapc ref here without holding | |
90 | * any locks! | |
91 | */ | |
92 | snapc = ceph_get_snap_context(ci->i_snap_realm->cached_context); | |
93 | ||
94 | /* dirty the head */ | |
be655596 | 95 | spin_lock(&ci->i_ceph_lock); |
7d8cb26d | 96 | if (ci->i_head_snapc == NULL) |
1d3576fd SW |
97 | ci->i_head_snapc = ceph_get_snap_context(snapc); |
98 | ++ci->i_wrbuffer_ref_head; | |
99 | if (ci->i_wrbuffer_ref == 0) | |
0444d76a | 100 | ihold(inode); |
1d3576fd SW |
101 | ++ci->i_wrbuffer_ref; |
102 | dout("%p set_page_dirty %p idx %lu head %d/%d -> %d/%d " | |
103 | "snapc %p seq %lld (%d snaps)\n", | |
104 | mapping->host, page, page->index, | |
105 | ci->i_wrbuffer_ref-1, ci->i_wrbuffer_ref_head-1, | |
106 | ci->i_wrbuffer_ref, ci->i_wrbuffer_ref_head, | |
107 | snapc, snapc->seq, snapc->num_snaps); | |
be655596 | 108 | spin_unlock(&ci->i_ceph_lock); |
1d3576fd SW |
109 | |
110 | /* now adjust page */ | |
111 | spin_lock_irq(&mapping->tree_lock); | |
112 | if (page->mapping) { /* Race with truncate? */ | |
113 | WARN_ON_ONCE(!PageUptodate(page)); | |
679ceace | 114 | account_page_dirtied(page, page->mapping); |
1d3576fd SW |
115 | radix_tree_tag_set(&mapping->page_tree, |
116 | page_index(page), PAGECACHE_TAG_DIRTY); | |
117 | ||
118 | /* | |
119 | * Reference snap context in page->private. Also set | |
120 | * PagePrivate so that we get invalidatepage callback. | |
121 | */ | |
122 | page->private = (unsigned long)snapc; | |
123 | SetPagePrivate(page); | |
124 | } else { | |
125 | dout("ANON set_page_dirty %p (raced truncate?)\n", page); | |
126 | undo = 1; | |
127 | } | |
128 | ||
129 | spin_unlock_irq(&mapping->tree_lock); | |
130 | ||
131 | if (undo) | |
132 | /* whoops, we failed to dirty the page */ | |
133 | ceph_put_wrbuffer_cap_refs(ci, 1, snapc); | |
134 | ||
135 | __mark_inode_dirty(mapping->host, I_DIRTY_PAGES); | |
136 | ||
137 | BUG_ON(!PageDirty(page)); | |
138 | return 1; | |
139 | } | |
140 | ||
141 | /* | |
142 | * If we are truncating the full page (i.e. offset == 0), adjust the | |
143 | * dirty page counters appropriately. Only called if there is private | |
144 | * data on the page. | |
145 | */ | |
d47992f8 LC |
146 | static void ceph_invalidatepage(struct page *page, unsigned int offset, |
147 | unsigned int length) | |
1d3576fd | 148 | { |
4ce1e9ad | 149 | struct inode *inode; |
1d3576fd | 150 | struct ceph_inode_info *ci; |
61600ef8 | 151 | struct ceph_snap_context *snapc = page_snap_context(page); |
1d3576fd SW |
152 | |
153 | BUG_ON(!PageLocked(page)); | |
1d3576fd SW |
154 | BUG_ON(!PagePrivate(page)); |
155 | BUG_ON(!page->mapping); | |
156 | ||
4ce1e9ad AB |
157 | inode = page->mapping->host; |
158 | ||
1d3576fd SW |
159 | /* |
160 | * We can get non-dirty pages here due to races between | |
161 | * set_page_dirty and truncate_complete_page; just spit out a | |
162 | * warning, in case we end up with accounting problems later. | |
163 | */ | |
164 | if (!PageDirty(page)) | |
165 | pr_err("%p invalidatepage %p page not dirty\n", inode, page); | |
166 | ||
569d39fc | 167 | if (offset == 0 && length == PAGE_CACHE_SIZE) |
1d3576fd SW |
168 | ClearPageChecked(page); |
169 | ||
170 | ci = ceph_inode(inode); | |
569d39fc LC |
171 | if (offset == 0 && length == PAGE_CACHE_SIZE) { |
172 | dout("%p invalidatepage %p idx %lu full dirty page\n", | |
173 | inode, page, page->index); | |
1d3576fd SW |
174 | ceph_put_wrbuffer_cap_refs(ci, 1, snapc); |
175 | ceph_put_snap_context(snapc); | |
176 | page->private = 0; | |
177 | ClearPagePrivate(page); | |
178 | } else { | |
569d39fc LC |
179 | dout("%p invalidatepage %p idx %lu partial dirty page %u(%u)\n", |
180 | inode, page, page->index, offset, length); | |
1d3576fd SW |
181 | } |
182 | } | |
183 | ||
184 | /* just a sanity check */ | |
185 | static int ceph_releasepage(struct page *page, gfp_t g) | |
186 | { | |
187 | struct inode *inode = page->mapping ? page->mapping->host : NULL; | |
188 | dout("%p releasepage %p idx %lu\n", inode, page, page->index); | |
189 | WARN_ON(PageDirty(page)); | |
1d3576fd SW |
190 | WARN_ON(PagePrivate(page)); |
191 | return 0; | |
192 | } | |
193 | ||
194 | /* | |
195 | * read a single page, without unlocking it. | |
196 | */ | |
197 | static int readpage_nounlock(struct file *filp, struct page *page) | |
198 | { | |
496ad9aa | 199 | struct inode *inode = file_inode(filp); |
1d3576fd | 200 | struct ceph_inode_info *ci = ceph_inode(inode); |
3d14c5d2 YS |
201 | struct ceph_osd_client *osdc = |
202 | &ceph_inode_to_client(inode)->client->osdc; | |
1d3576fd SW |
203 | int err = 0; |
204 | u64 len = PAGE_CACHE_SIZE; | |
205 | ||
206 | dout("readpage inode %p file %p page %p index %lu\n", | |
207 | inode, filp, page, page->index); | |
208 | err = ceph_osdc_readpages(osdc, ceph_vino(inode), &ci->i_layout, | |
6285bc23 | 209 | (u64) page_offset(page), &len, |
1d3576fd | 210 | ci->i_truncate_seq, ci->i_truncate_size, |
b7495fc2 | 211 | &page, 1, 0); |
1d3576fd SW |
212 | if (err == -ENOENT) |
213 | err = 0; | |
214 | if (err < 0) { | |
215 | SetPageError(page); | |
216 | goto out; | |
217 | } else if (err < PAGE_CACHE_SIZE) { | |
218 | /* zero fill remainder of page */ | |
219 | zero_user_segment(page, err, PAGE_CACHE_SIZE); | |
220 | } | |
221 | SetPageUptodate(page); | |
222 | ||
223 | out: | |
224 | return err < 0 ? err : 0; | |
225 | } | |
226 | ||
227 | static int ceph_readpage(struct file *filp, struct page *page) | |
228 | { | |
229 | int r = readpage_nounlock(filp, page); | |
230 | unlock_page(page); | |
231 | return r; | |
232 | } | |
233 | ||
234 | /* | |
7c272194 | 235 | * Finish an async read(ahead) op. |
1d3576fd | 236 | */ |
7c272194 | 237 | static void finish_read(struct ceph_osd_request *req, struct ceph_msg *msg) |
1d3576fd | 238 | { |
7c272194 | 239 | struct inode *inode = req->r_inode; |
87060c10 | 240 | struct ceph_osd_data *osd_data; |
1b83bef2 SW |
241 | int rc = req->r_result; |
242 | int bytes = le32_to_cpu(msg->hdr.data_len); | |
e0c59487 | 243 | int num_pages; |
7c272194 | 244 | int i; |
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 */ | |
406e2c9f | 249 | osd_data = osd_req_op_extent_osd_data(req, 0); |
87060c10 AE |
250 | BUG_ON(osd_data->type != CEPH_OSD_DATA_TYPE_PAGES); |
251 | num_pages = calc_pages_for((u64)osd_data->alignment, | |
252 | (u64)osd_data->length); | |
e0c59487 | 253 | for (i = 0; i < num_pages; i++) { |
87060c10 | 254 | struct page *page = osd_data->pages[i]; |
7c272194 SW |
255 | |
256 | if (bytes < (int)PAGE_CACHE_SIZE) { | |
257 | /* zero (remainder of) page */ | |
258 | int s = bytes < 0 ? 0 : bytes; | |
259 | zero_user_segment(page, s, PAGE_CACHE_SIZE); | |
1d3576fd | 260 | } |
7c272194 SW |
261 | dout("finish_read %p uptodate %p idx %lu\n", inode, page, |
262 | page->index); | |
263 | flush_dcache_page(page); | |
264 | SetPageUptodate(page); | |
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); |
7c272194 SW |
334 | |
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)) { |
1d3576fd | 339 | page_cache_release(page); |
7c272194 | 340 | dout("start_read %p add_to_page_cache failed %p\n", |
1d3576fd | 341 | inode, page); |
7c272194 SW |
342 | nr_pages = i; |
343 | goto out_pages; | |
1d3576fd | 344 | } |
7c272194 | 345 | pages[i] = page; |
1d3576fd | 346 | } |
406e2c9f | 347 | osd_req_op_extent_osd_data_pages(req, 0, pages, len, 0, false, false); |
7c272194 SW |
348 | req->r_callback = finish_read; |
349 | req->r_inode = inode; | |
350 | ||
79528734 | 351 | ceph_osdc_build_request(req, off, NULL, vino.snap, NULL); |
02ee07d3 | 352 | |
7c272194 SW |
353 | dout("start_read %p starting %p %lld~%lld\n", inode, req, off, len); |
354 | ret = ceph_osdc_start_request(osdc, req, false); | |
355 | if (ret < 0) | |
356 | goto out_pages; | |
357 | ceph_osdc_put_request(req); | |
358 | return nr_pages; | |
359 | ||
360 | out_pages: | |
8884d53d | 361 | ceph_unlock_page_vector(pages, nr_pages); |
7c272194 | 362 | ceph_release_page_vector(pages, nr_pages); |
7c272194 SW |
363 | out: |
364 | ceph_osdc_put_request(req); | |
365 | return ret; | |
366 | } | |
1d3576fd | 367 | |
7c272194 SW |
368 | |
369 | /* | |
370 | * Read multiple pages. Leave pages we don't read + unlock in page_list; | |
371 | * the caller (VM) cleans them up. | |
372 | */ | |
373 | static int ceph_readpages(struct file *file, struct address_space *mapping, | |
374 | struct list_head *page_list, unsigned nr_pages) | |
375 | { | |
496ad9aa | 376 | struct inode *inode = file_inode(file); |
0d66a487 | 377 | struct ceph_fs_client *fsc = ceph_inode_to_client(inode); |
7c272194 | 378 | int rc = 0; |
0d66a487 SW |
379 | int max = 0; |
380 | ||
381 | if (fsc->mount_options->rsize >= PAGE_CACHE_SIZE) | |
382 | max = (fsc->mount_options->rsize + PAGE_CACHE_SIZE - 1) | |
383 | >> PAGE_SHIFT; | |
7c272194 | 384 | |
2794a82a AE |
385 | dout("readpages %p file %p nr_pages %d max %d\n", inode, |
386 | file, nr_pages, | |
0d66a487 | 387 | max); |
7c272194 | 388 | while (!list_empty(page_list)) { |
0d66a487 | 389 | rc = start_read(inode, page_list, max); |
7c272194 SW |
390 | if (rc < 0) |
391 | goto out; | |
392 | BUG_ON(rc == 0); | |
393 | } | |
1d3576fd | 394 | out: |
7c272194 | 395 | dout("readpages %p file %p ret %d\n", inode, file, rc); |
1d3576fd SW |
396 | return rc; |
397 | } | |
398 | ||
399 | /* | |
400 | * Get ref for the oldest snapc for an inode with dirty data... that is, the | |
401 | * only snap context we are allowed to write back. | |
1d3576fd | 402 | */ |
6298a337 SW |
403 | static struct ceph_snap_context *get_oldest_context(struct inode *inode, |
404 | u64 *snap_size) | |
1d3576fd SW |
405 | { |
406 | struct ceph_inode_info *ci = ceph_inode(inode); | |
407 | struct ceph_snap_context *snapc = NULL; | |
408 | struct ceph_cap_snap *capsnap = NULL; | |
409 | ||
be655596 | 410 | spin_lock(&ci->i_ceph_lock); |
1d3576fd SW |
411 | list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) { |
412 | dout(" cap_snap %p snapc %p has %d dirty pages\n", capsnap, | |
413 | capsnap->context, capsnap->dirty_pages); | |
414 | if (capsnap->dirty_pages) { | |
415 | snapc = ceph_get_snap_context(capsnap->context); | |
416 | if (snap_size) | |
417 | *snap_size = capsnap->size; | |
418 | break; | |
419 | } | |
420 | } | |
7d8cb26d | 421 | if (!snapc && ci->i_wrbuffer_ref_head) { |
80e755fe | 422 | snapc = ceph_get_snap_context(ci->i_head_snapc); |
1d3576fd SW |
423 | dout(" head snapc %p has %d dirty pages\n", |
424 | snapc, ci->i_wrbuffer_ref_head); | |
425 | } | |
be655596 | 426 | spin_unlock(&ci->i_ceph_lock); |
1d3576fd SW |
427 | return snapc; |
428 | } | |
429 | ||
430 | /* | |
431 | * Write a single page, but leave the page locked. | |
432 | * | |
433 | * If we get a write error, set the page error bit, but still adjust the | |
434 | * dirty page accounting (i.e., page is no longer dirty). | |
435 | */ | |
436 | static int writepage_nounlock(struct page *page, struct writeback_control *wbc) | |
437 | { | |
438 | struct inode *inode; | |
439 | struct ceph_inode_info *ci; | |
3d14c5d2 | 440 | struct ceph_fs_client *fsc; |
1d3576fd | 441 | struct ceph_osd_client *osdc; |
6298a337 | 442 | struct ceph_snap_context *snapc, *oldest; |
fc2744aa | 443 | loff_t page_off = page_offset(page); |
2baba250 | 444 | long writeback_stat; |
fc2744aa YZ |
445 | u64 truncate_size, snap_size = 0; |
446 | u32 truncate_seq; | |
447 | int err = 0, len = PAGE_CACHE_SIZE; | |
1d3576fd SW |
448 | |
449 | dout("writepage %p idx %lu\n", page, page->index); | |
450 | ||
451 | if (!page->mapping || !page->mapping->host) { | |
452 | dout("writepage %p - no mapping\n", page); | |
453 | return -EFAULT; | |
454 | } | |
455 | inode = page->mapping->host; | |
456 | ci = ceph_inode(inode); | |
3d14c5d2 YS |
457 | fsc = ceph_inode_to_client(inode); |
458 | osdc = &fsc->client->osdc; | |
1d3576fd SW |
459 | |
460 | /* verify this is a writeable snap context */ | |
61600ef8 | 461 | snapc = page_snap_context(page); |
1d3576fd SW |
462 | if (snapc == NULL) { |
463 | dout("writepage %p page %p not dirty?\n", inode, page); | |
464 | goto out; | |
465 | } | |
6298a337 SW |
466 | oldest = get_oldest_context(inode, &snap_size); |
467 | if (snapc->seq > oldest->seq) { | |
1d3576fd | 468 | dout("writepage %p page %p snapc %p not writeable - noop\n", |
61600ef8 | 469 | inode, page, snapc); |
1d3576fd SW |
470 | /* we should only noop if called by kswapd */ |
471 | WARN_ON((current->flags & PF_MEMALLOC) == 0); | |
6298a337 | 472 | ceph_put_snap_context(oldest); |
1d3576fd SW |
473 | goto out; |
474 | } | |
6298a337 | 475 | ceph_put_snap_context(oldest); |
1d3576fd | 476 | |
fc2744aa YZ |
477 | spin_lock(&ci->i_ceph_lock); |
478 | truncate_seq = ci->i_truncate_seq; | |
479 | truncate_size = ci->i_truncate_size; | |
480 | if (!snap_size) | |
481 | snap_size = i_size_read(inode); | |
482 | spin_unlock(&ci->i_ceph_lock); | |
483 | ||
1d3576fd | 484 | /* is this a partial page at end of file? */ |
fc2744aa YZ |
485 | if (page_off >= snap_size) { |
486 | dout("%p page eof %llu\n", page, snap_size); | |
487 | goto out; | |
488 | } | |
489 | if (snap_size < page_off + len) | |
490 | len = snap_size - page_off; | |
1d3576fd | 491 | |
ae00d4f3 SW |
492 | dout("writepage %p page %p index %lu on %llu~%u snapc %p\n", |
493 | inode, page, page->index, page_off, len, snapc); | |
1d3576fd | 494 | |
3d14c5d2 | 495 | writeback_stat = atomic_long_inc_return(&fsc->writeback_count); |
2baba250 | 496 | if (writeback_stat > |
3d14c5d2 YS |
497 | CONGESTION_ON_THRESH(fsc->mount_options->congestion_kb)) |
498 | set_bdi_congested(&fsc->backing_dev_info, BLK_RW_ASYNC); | |
2baba250 | 499 | |
1d3576fd SW |
500 | set_page_writeback(page); |
501 | err = ceph_osdc_writepages(osdc, ceph_vino(inode), | |
502 | &ci->i_layout, snapc, | |
503 | page_off, len, | |
fc2744aa | 504 | truncate_seq, truncate_size, |
24808826 | 505 | &inode->i_mtime, &page, 1); |
1d3576fd SW |
506 | if (err < 0) { |
507 | dout("writepage setting page/mapping error %d %p\n", err, page); | |
508 | SetPageError(page); | |
509 | mapping_set_error(&inode->i_data, err); | |
510 | if (wbc) | |
511 | wbc->pages_skipped++; | |
512 | } else { | |
513 | dout("writepage cleaned page %p\n", page); | |
514 | err = 0; /* vfs expects us to return 0 */ | |
515 | } | |
516 | page->private = 0; | |
517 | ClearPagePrivate(page); | |
518 | end_page_writeback(page); | |
519 | ceph_put_wrbuffer_cap_refs(ci, 1, snapc); | |
6298a337 | 520 | ceph_put_snap_context(snapc); /* page's reference */ |
1d3576fd SW |
521 | out: |
522 | return err; | |
523 | } | |
524 | ||
525 | static int ceph_writepage(struct page *page, struct writeback_control *wbc) | |
526 | { | |
dbd646a8 YS |
527 | int err; |
528 | struct inode *inode = page->mapping->host; | |
529 | BUG_ON(!inode); | |
70b666c3 | 530 | ihold(inode); |
dbd646a8 | 531 | err = writepage_nounlock(page, wbc); |
1d3576fd | 532 | unlock_page(page); |
dbd646a8 | 533 | iput(inode); |
1d3576fd SW |
534 | return err; |
535 | } | |
536 | ||
537 | ||
538 | /* | |
539 | * lame release_pages helper. release_pages() isn't exported to | |
540 | * modules. | |
541 | */ | |
542 | static void ceph_release_pages(struct page **pages, int num) | |
543 | { | |
544 | struct pagevec pvec; | |
545 | int i; | |
546 | ||
547 | pagevec_init(&pvec, 0); | |
548 | for (i = 0; i < num; i++) { | |
549 | if (pagevec_add(&pvec, pages[i]) == 0) | |
550 | pagevec_release(&pvec); | |
551 | } | |
552 | pagevec_release(&pvec); | |
553 | } | |
554 | ||
555 | ||
556 | /* | |
557 | * async writeback completion handler. | |
558 | * | |
559 | * If we get an error, set the mapping error bit, but not the individual | |
560 | * page error bits. | |
561 | */ | |
562 | static void writepages_finish(struct ceph_osd_request *req, | |
563 | struct ceph_msg *msg) | |
564 | { | |
565 | struct inode *inode = req->r_inode; | |
1d3576fd | 566 | struct ceph_inode_info *ci = ceph_inode(inode); |
87060c10 | 567 | struct ceph_osd_data *osd_data; |
1d3576fd | 568 | unsigned wrote; |
1d3576fd | 569 | struct page *page; |
e0c59487 | 570 | int num_pages; |
1d3576fd SW |
571 | int i; |
572 | struct ceph_snap_context *snapc = req->r_snapc; | |
573 | struct address_space *mapping = inode->i_mapping; | |
1b83bef2 | 574 | int rc = req->r_result; |
79528734 | 575 | u64 bytes = req->r_ops[0].extent.length; |
3d14c5d2 | 576 | struct ceph_fs_client *fsc = ceph_inode_to_client(inode); |
2baba250 | 577 | long writeback_stat; |
7ff899da | 578 | unsigned issued = ceph_caps_issued(ci); |
1d3576fd | 579 | |
406e2c9f | 580 | osd_data = osd_req_op_extent_osd_data(req, 0); |
87060c10 AE |
581 | BUG_ON(osd_data->type != CEPH_OSD_DATA_TYPE_PAGES); |
582 | num_pages = calc_pages_for((u64)osd_data->alignment, | |
583 | (u64)osd_data->length); | |
1d3576fd | 584 | if (rc >= 0) { |
79788c69 SW |
585 | /* |
586 | * Assume we wrote the pages we originally sent. The | |
587 | * osd might reply with fewer pages if our writeback | |
588 | * raced with a truncation and was adjusted at the osd, | |
589 | * so don't believe the reply. | |
590 | */ | |
e0c59487 | 591 | wrote = num_pages; |
1d3576fd SW |
592 | } else { |
593 | wrote = 0; | |
594 | mapping_set_error(mapping, rc); | |
595 | } | |
596 | dout("writepages_finish %p rc %d bytes %llu wrote %d (pages)\n", | |
597 | inode, rc, bytes, wrote); | |
598 | ||
599 | /* clean all pages */ | |
e0c59487 | 600 | for (i = 0; i < num_pages; i++) { |
87060c10 | 601 | page = osd_data->pages[i]; |
1d3576fd SW |
602 | BUG_ON(!page); |
603 | WARN_ON(!PageUptodate(page)); | |
604 | ||
2baba250 | 605 | writeback_stat = |
3d14c5d2 | 606 | atomic_long_dec_return(&fsc->writeback_count); |
2baba250 | 607 | if (writeback_stat < |
3d14c5d2 YS |
608 | CONGESTION_OFF_THRESH(fsc->mount_options->congestion_kb)) |
609 | clear_bdi_congested(&fsc->backing_dev_info, | |
2baba250 YS |
610 | BLK_RW_ASYNC); |
611 | ||
61600ef8 | 612 | ceph_put_snap_context(page_snap_context(page)); |
1d3576fd SW |
613 | page->private = 0; |
614 | ClearPagePrivate(page); | |
1d3576fd SW |
615 | dout("unlocking %d %p\n", i, page); |
616 | end_page_writeback(page); | |
e63dc5c7 YS |
617 | |
618 | /* | |
619 | * We lost the cache cap, need to truncate the page before | |
620 | * it is unlocked, otherwise we'd truncate it later in the | |
621 | * page truncation thread, possibly losing some data that | |
622 | * raced its way in | |
623 | */ | |
2962507c | 624 | if ((issued & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) == 0) |
e63dc5c7 YS |
625 | generic_error_remove_page(inode->i_mapping, page); |
626 | ||
1d3576fd SW |
627 | unlock_page(page); |
628 | } | |
629 | dout("%p wrote+cleaned %d pages\n", inode, wrote); | |
e0c59487 | 630 | ceph_put_wrbuffer_cap_refs(ci, num_pages, snapc); |
1d3576fd | 631 | |
87060c10 AE |
632 | ceph_release_pages(osd_data->pages, num_pages); |
633 | if (osd_data->pages_from_pool) | |
634 | mempool_free(osd_data->pages, | |
640ef79d | 635 | ceph_sb_to_client(inode->i_sb)->wb_pagevec_pool); |
1d3576fd | 636 | else |
87060c10 | 637 | kfree(osd_data->pages); |
1d3576fd SW |
638 | ceph_osdc_put_request(req); |
639 | } | |
640 | ||
1d3576fd SW |
641 | /* |
642 | * initiate async writeback | |
643 | */ | |
644 | static int ceph_writepages_start(struct address_space *mapping, | |
645 | struct writeback_control *wbc) | |
646 | { | |
647 | struct inode *inode = mapping->host; | |
1d3576fd | 648 | struct ceph_inode_info *ci = ceph_inode(inode); |
fc2744aa YZ |
649 | struct ceph_fs_client *fsc = ceph_inode_to_client(inode); |
650 | struct ceph_vino vino = ceph_vino(inode); | |
1d3576fd SW |
651 | pgoff_t index, start, end; |
652 | int range_whole = 0; | |
653 | int should_loop = 1; | |
654 | pgoff_t max_pages = 0, max_pages_ever = 0; | |
80e755fe | 655 | struct ceph_snap_context *snapc = NULL, *last_snapc = NULL, *pgsnapc; |
1d3576fd SW |
656 | struct pagevec pvec; |
657 | int done = 0; | |
658 | int rc = 0; | |
659 | unsigned wsize = 1 << inode->i_blkbits; | |
660 | struct ceph_osd_request *req = NULL; | |
661 | int do_sync; | |
fc2744aa YZ |
662 | u64 truncate_size, snap_size; |
663 | u32 truncate_seq; | |
1d3576fd SW |
664 | |
665 | /* | |
666 | * Include a 'sync' in the OSD request if this is a data | |
667 | * integrity write (e.g., O_SYNC write or fsync()), or if our | |
668 | * cap is being revoked. | |
669 | */ | |
c62988ec | 670 | if ((wbc->sync_mode == WB_SYNC_ALL) || |
671 | ceph_caps_revoking(ci, CEPH_CAP_FILE_BUFFER)) | |
1d3576fd SW |
672 | do_sync = 1; |
673 | dout("writepages_start %p dosync=%d (mode=%s)\n", | |
674 | inode, do_sync, | |
675 | wbc->sync_mode == WB_SYNC_NONE ? "NONE" : | |
676 | (wbc->sync_mode == WB_SYNC_ALL ? "ALL" : "HOLD")); | |
677 | ||
3d14c5d2 | 678 | if (fsc->mount_state == CEPH_MOUNT_SHUTDOWN) { |
1d3576fd SW |
679 | pr_warning("writepage_start %p on forced umount\n", inode); |
680 | return -EIO; /* we're in a forced umount, don't write! */ | |
681 | } | |
3d14c5d2 YS |
682 | if (fsc->mount_options->wsize && fsc->mount_options->wsize < wsize) |
683 | wsize = fsc->mount_options->wsize; | |
1d3576fd SW |
684 | if (wsize < PAGE_CACHE_SIZE) |
685 | wsize = PAGE_CACHE_SIZE; | |
686 | max_pages_ever = wsize >> PAGE_CACHE_SHIFT; | |
687 | ||
688 | pagevec_init(&pvec, 0); | |
689 | ||
1d3576fd SW |
690 | /* where to start/end? */ |
691 | if (wbc->range_cyclic) { | |
692 | start = mapping->writeback_index; /* Start from prev offset */ | |
693 | end = -1; | |
694 | dout(" cyclic, start at %lu\n", start); | |
695 | } else { | |
696 | start = wbc->range_start >> PAGE_CACHE_SHIFT; | |
697 | end = wbc->range_end >> PAGE_CACHE_SHIFT; | |
698 | if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) | |
699 | range_whole = 1; | |
700 | should_loop = 0; | |
701 | dout(" not cyclic, %lu to %lu\n", start, end); | |
702 | } | |
703 | index = start; | |
704 | ||
705 | retry: | |
706 | /* find oldest snap context with dirty data */ | |
707 | ceph_put_snap_context(snapc); | |
1ac0fc8a | 708 | snap_size = 0; |
1d3576fd SW |
709 | snapc = get_oldest_context(inode, &snap_size); |
710 | if (!snapc) { | |
711 | /* hmm, why does writepages get called when there | |
712 | is no dirty data? */ | |
713 | dout(" no snap context with dirty data?\n"); | |
714 | goto out; | |
715 | } | |
1ac0fc8a YZ |
716 | if (snap_size == 0) |
717 | snap_size = i_size_read(inode); | |
1d3576fd SW |
718 | dout(" oldest snapc is %p seq %lld (%d snaps)\n", |
719 | snapc, snapc->seq, snapc->num_snaps); | |
fc2744aa YZ |
720 | |
721 | spin_lock(&ci->i_ceph_lock); | |
722 | truncate_seq = ci->i_truncate_seq; | |
723 | truncate_size = ci->i_truncate_size; | |
724 | if (!snap_size) | |
725 | snap_size = i_size_read(inode); | |
726 | spin_unlock(&ci->i_ceph_lock); | |
727 | ||
1d3576fd SW |
728 | if (last_snapc && snapc != last_snapc) { |
729 | /* if we switched to a newer snapc, restart our scan at the | |
730 | * start of the original file range. */ | |
731 | dout(" snapc differs from last pass, restarting at %lu\n", | |
732 | index); | |
733 | index = start; | |
734 | } | |
735 | last_snapc = snapc; | |
736 | ||
737 | while (!done && index <= end) { | |
e5975c7c | 738 | int num_ops = do_sync ? 2 : 1; |
1d3576fd SW |
739 | unsigned i; |
740 | int first; | |
741 | pgoff_t next; | |
742 | int pvec_pages, locked_pages; | |
e5975c7c AE |
743 | struct page **pages = NULL; |
744 | mempool_t *pool = NULL; /* Becomes non-null if mempool used */ | |
1d3576fd SW |
745 | struct page *page; |
746 | int want; | |
747 | u64 offset, len; | |
2baba250 | 748 | long writeback_stat; |
1d3576fd SW |
749 | |
750 | next = 0; | |
751 | locked_pages = 0; | |
752 | max_pages = max_pages_ever; | |
753 | ||
754 | get_more_pages: | |
755 | first = -1; | |
756 | want = min(end - index, | |
757 | min((pgoff_t)PAGEVEC_SIZE, | |
758 | max_pages - (pgoff_t)locked_pages) - 1) | |
759 | + 1; | |
760 | pvec_pages = pagevec_lookup_tag(&pvec, mapping, &index, | |
761 | PAGECACHE_TAG_DIRTY, | |
762 | want); | |
763 | dout("pagevec_lookup_tag got %d\n", pvec_pages); | |
764 | if (!pvec_pages && !locked_pages) | |
765 | break; | |
766 | for (i = 0; i < pvec_pages && locked_pages < max_pages; i++) { | |
767 | page = pvec.pages[i]; | |
768 | dout("? %p idx %lu\n", page, page->index); | |
769 | if (locked_pages == 0) | |
770 | lock_page(page); /* first page */ | |
771 | else if (!trylock_page(page)) | |
772 | break; | |
773 | ||
774 | /* only dirty pages, or our accounting breaks */ | |
775 | if (unlikely(!PageDirty(page)) || | |
776 | unlikely(page->mapping != mapping)) { | |
777 | dout("!dirty or !mapping %p\n", page); | |
778 | unlock_page(page); | |
779 | break; | |
780 | } | |
781 | if (!wbc->range_cyclic && page->index > end) { | |
782 | dout("end of range %p\n", page); | |
783 | done = 1; | |
784 | unlock_page(page); | |
785 | break; | |
786 | } | |
787 | if (next && (page->index != next)) { | |
788 | dout("not consecutive %p\n", page); | |
789 | unlock_page(page); | |
790 | break; | |
791 | } | |
792 | if (wbc->sync_mode != WB_SYNC_NONE) { | |
793 | dout("waiting on writeback %p\n", page); | |
794 | wait_on_page_writeback(page); | |
795 | } | |
1ac0fc8a YZ |
796 | if (page_offset(page) >= snap_size) { |
797 | dout("%p page eof %llu\n", page, snap_size); | |
1d3576fd SW |
798 | done = 1; |
799 | unlock_page(page); | |
800 | break; | |
801 | } | |
802 | if (PageWriteback(page)) { | |
803 | dout("%p under writeback\n", page); | |
804 | unlock_page(page); | |
805 | break; | |
806 | } | |
807 | ||
808 | /* only if matching snap context */ | |
61600ef8 | 809 | pgsnapc = page_snap_context(page); |
80e755fe SW |
810 | if (pgsnapc->seq > snapc->seq) { |
811 | dout("page snapc %p %lld > oldest %p %lld\n", | |
812 | pgsnapc, pgsnapc->seq, snapc, snapc->seq); | |
1d3576fd SW |
813 | unlock_page(page); |
814 | if (!locked_pages) | |
815 | continue; /* keep looking for snap */ | |
816 | break; | |
817 | } | |
818 | ||
819 | if (!clear_page_dirty_for_io(page)) { | |
820 | dout("%p !clear_page_dirty_for_io\n", page); | |
821 | unlock_page(page); | |
822 | break; | |
823 | } | |
824 | ||
e5975c7c AE |
825 | /* |
826 | * We have something to write. If this is | |
827 | * the first locked page this time through, | |
828 | * allocate an osd request and a page array | |
829 | * that it will use. | |
830 | */ | |
1d3576fd | 831 | if (locked_pages == 0) { |
e5975c7c | 832 | BUG_ON(pages); |
1d3576fd | 833 | /* prepare async write request */ |
e5975c7c | 834 | offset = (u64)page_offset(page); |
1d3576fd | 835 | len = wsize; |
fc2744aa YZ |
836 | req = ceph_osdc_new_request(&fsc->client->osdc, |
837 | &ci->i_layout, vino, | |
838 | offset, &len, num_ops, | |
839 | CEPH_OSD_OP_WRITE, | |
840 | CEPH_OSD_FLAG_WRITE | | |
841 | CEPH_OSD_FLAG_ONDISK, | |
842 | snapc, truncate_seq, | |
843 | truncate_size, true); | |
6816282d SW |
844 | if (IS_ERR(req)) { |
845 | rc = PTR_ERR(req); | |
8c71897b HC |
846 | unlock_page(page); |
847 | break; | |
848 | } | |
849 | ||
88486957 AE |
850 | req->r_callback = writepages_finish; |
851 | req->r_inode = inode; | |
852 | ||
853 | max_pages = calc_pages_for(0, (u64)len); | |
fc2744aa YZ |
854 | pages = kmalloc(max_pages * sizeof (*pages), |
855 | GFP_NOFS); | |
88486957 AE |
856 | if (!pages) { |
857 | pool = fsc->wb_pagevec_pool; | |
88486957 | 858 | pages = mempool_alloc(pool, GFP_NOFS); |
e5975c7c | 859 | BUG_ON(!pages); |
88486957 | 860 | } |
1d3576fd SW |
861 | } |
862 | ||
863 | /* note position of first page in pvec */ | |
864 | if (first < 0) | |
865 | first = i; | |
866 | dout("%p will write page %p idx %lu\n", | |
867 | inode, page, page->index); | |
2baba250 | 868 | |
213c99ee | 869 | writeback_stat = |
3d14c5d2 | 870 | atomic_long_inc_return(&fsc->writeback_count); |
213c99ee | 871 | if (writeback_stat > CONGESTION_ON_THRESH( |
3d14c5d2 YS |
872 | fsc->mount_options->congestion_kb)) { |
873 | set_bdi_congested(&fsc->backing_dev_info, | |
213c99ee | 874 | BLK_RW_ASYNC); |
2baba250 YS |
875 | } |
876 | ||
1d3576fd | 877 | set_page_writeback(page); |
e5975c7c | 878 | pages[locked_pages] = page; |
1d3576fd SW |
879 | locked_pages++; |
880 | next = page->index + 1; | |
881 | } | |
882 | ||
883 | /* did we get anything? */ | |
884 | if (!locked_pages) | |
885 | goto release_pvec_pages; | |
886 | if (i) { | |
887 | int j; | |
888 | BUG_ON(!locked_pages || first < 0); | |
889 | ||
890 | if (pvec_pages && i == pvec_pages && | |
891 | locked_pages < max_pages) { | |
892 | dout("reached end pvec, trying for more\n"); | |
893 | pagevec_reinit(&pvec); | |
894 | goto get_more_pages; | |
895 | } | |
896 | ||
897 | /* shift unused pages over in the pvec... we | |
898 | * will need to release them below. */ | |
899 | for (j = i; j < pvec_pages; j++) { | |
900 | dout(" pvec leftover page %p\n", | |
901 | pvec.pages[j]); | |
902 | pvec.pages[j-i+first] = pvec.pages[j]; | |
903 | } | |
904 | pvec.nr -= i-first; | |
905 | } | |
906 | ||
e5975c7c AE |
907 | /* Format the osd request message and submit the write */ |
908 | ||
909 | offset = page_offset(pages[0]); | |
1ac0fc8a | 910 | len = min(snap_size - offset, |
1d3576fd SW |
911 | (u64)locked_pages << PAGE_CACHE_SHIFT); |
912 | dout("writepages got %d pages at %llu~%llu\n", | |
913 | locked_pages, offset, len); | |
914 | ||
406e2c9f | 915 | osd_req_op_extent_osd_data_pages(req, 0, pages, len, 0, |
a4ce40a9 | 916 | !!pool, false); |
e5975c7c AE |
917 | |
918 | pages = NULL; /* request message now owns the pages array */ | |
919 | pool = NULL; | |
920 | ||
921 | /* Update the write op length in case we changed it */ | |
922 | ||
c99d2d4a | 923 | osd_req_op_extent_update(req, 0, len); |
e5975c7c AE |
924 | |
925 | vino = ceph_vino(inode); | |
79528734 AE |
926 | ceph_osdc_build_request(req, offset, snapc, vino.snap, |
927 | &inode->i_mtime); | |
1d3576fd | 928 | |
9d6fcb08 SW |
929 | rc = ceph_osdc_start_request(&fsc->client->osdc, req, true); |
930 | BUG_ON(rc); | |
1d3576fd SW |
931 | req = NULL; |
932 | ||
933 | /* continue? */ | |
934 | index = next; | |
935 | wbc->nr_to_write -= locked_pages; | |
936 | if (wbc->nr_to_write <= 0) | |
937 | done = 1; | |
938 | ||
939 | release_pvec_pages: | |
940 | dout("pagevec_release on %d pages (%p)\n", (int)pvec.nr, | |
941 | pvec.nr ? pvec.pages[0] : NULL); | |
942 | pagevec_release(&pvec); | |
943 | ||
944 | if (locked_pages && !done) | |
945 | goto retry; | |
946 | } | |
947 | ||
948 | if (should_loop && !done) { | |
949 | /* more to do; loop back to beginning of file */ | |
950 | dout("writepages looping back to beginning of file\n"); | |
951 | should_loop = 0; | |
952 | index = 0; | |
953 | goto retry; | |
954 | } | |
955 | ||
956 | if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0)) | |
957 | mapping->writeback_index = index; | |
958 | ||
959 | out: | |
960 | if (req) | |
961 | ceph_osdc_put_request(req); | |
1d3576fd SW |
962 | ceph_put_snap_context(snapc); |
963 | dout("writepages done, rc = %d\n", rc); | |
1d3576fd SW |
964 | return rc; |
965 | } | |
966 | ||
967 | ||
968 | ||
969 | /* | |
970 | * See if a given @snapc is either writeable, or already written. | |
971 | */ | |
972 | static int context_is_writeable_or_written(struct inode *inode, | |
973 | struct ceph_snap_context *snapc) | |
974 | { | |
975 | struct ceph_snap_context *oldest = get_oldest_context(inode, NULL); | |
6298a337 SW |
976 | int ret = !oldest || snapc->seq <= oldest->seq; |
977 | ||
978 | ceph_put_snap_context(oldest); | |
979 | return ret; | |
1d3576fd SW |
980 | } |
981 | ||
982 | /* | |
983 | * We are only allowed to write into/dirty the page if the page is | |
984 | * clean, or already dirty within the same snap context. | |
8f883c24 SW |
985 | * |
986 | * called with page locked. | |
987 | * return success with page locked, | |
988 | * or any failure (incl -EAGAIN) with page unlocked. | |
1d3576fd | 989 | */ |
4af6b225 YS |
990 | static int ceph_update_writeable_page(struct file *file, |
991 | loff_t pos, unsigned len, | |
992 | struct page *page) | |
1d3576fd | 993 | { |
496ad9aa | 994 | struct inode *inode = file_inode(file); |
1d3576fd | 995 | struct ceph_inode_info *ci = ceph_inode(inode); |
3d14c5d2 | 996 | struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc; |
1d3576fd SW |
997 | loff_t page_off = pos & PAGE_CACHE_MASK; |
998 | int pos_in_page = pos & ~PAGE_CACHE_MASK; | |
999 | int end_in_page = pos_in_page + len; | |
1000 | loff_t i_size; | |
1d3576fd | 1001 | int r; |
80e755fe | 1002 | struct ceph_snap_context *snapc, *oldest; |
1d3576fd | 1003 | |
1d3576fd SW |
1004 | retry_locked: |
1005 | /* writepages currently holds page lock, but if we change that later, */ | |
1006 | wait_on_page_writeback(page); | |
1007 | ||
1008 | /* check snap context */ | |
1009 | BUG_ON(!ci->i_snap_realm); | |
1010 | down_read(&mdsc->snap_rwsem); | |
1011 | BUG_ON(!ci->i_snap_realm->cached_context); | |
61600ef8 | 1012 | snapc = page_snap_context(page); |
80e755fe | 1013 | if (snapc && snapc != ci->i_head_snapc) { |
1d3576fd SW |
1014 | /* |
1015 | * this page is already dirty in another (older) snap | |
1016 | * context! is it writeable now? | |
1017 | */ | |
80e755fe | 1018 | oldest = get_oldest_context(inode, NULL); |
1d3576fd SW |
1019 | up_read(&mdsc->snap_rwsem); |
1020 | ||
80e755fe | 1021 | if (snapc->seq > oldest->seq) { |
6298a337 | 1022 | ceph_put_snap_context(oldest); |
1d3576fd | 1023 | dout(" page %p snapc %p not current or oldest\n", |
6298a337 | 1024 | page, snapc); |
1d3576fd SW |
1025 | /* |
1026 | * queue for writeback, and wait for snapc to | |
1027 | * be writeable or written | |
1028 | */ | |
6298a337 | 1029 | snapc = ceph_get_snap_context(snapc); |
1d3576fd | 1030 | unlock_page(page); |
3c6f6b79 | 1031 | ceph_queue_writeback(inode); |
8f883c24 | 1032 | r = wait_event_interruptible(ci->i_cap_wq, |
1d3576fd SW |
1033 | context_is_writeable_or_written(inode, snapc)); |
1034 | ceph_put_snap_context(snapc); | |
8f883c24 SW |
1035 | if (r == -ERESTARTSYS) |
1036 | return r; | |
4af6b225 | 1037 | return -EAGAIN; |
1d3576fd | 1038 | } |
6298a337 | 1039 | ceph_put_snap_context(oldest); |
1d3576fd SW |
1040 | |
1041 | /* yay, writeable, do it now (without dropping page lock) */ | |
1042 | dout(" page %p snapc %p not current, but oldest\n", | |
1043 | page, snapc); | |
1044 | if (!clear_page_dirty_for_io(page)) | |
1045 | goto retry_locked; | |
1046 | r = writepage_nounlock(page, NULL); | |
1047 | if (r < 0) | |
1048 | goto fail_nosnap; | |
1049 | goto retry_locked; | |
1050 | } | |
1051 | ||
1052 | if (PageUptodate(page)) { | |
1053 | dout(" page %p already uptodate\n", page); | |
1054 | return 0; | |
1055 | } | |
1056 | ||
1057 | /* full page? */ | |
1058 | if (pos_in_page == 0 && len == PAGE_CACHE_SIZE) | |
1059 | return 0; | |
1060 | ||
1061 | /* past end of file? */ | |
1062 | i_size = inode->i_size; /* caller holds i_mutex */ | |
1063 | ||
1064 | if (i_size + len > inode->i_sb->s_maxbytes) { | |
1065 | /* file is too big */ | |
1066 | r = -EINVAL; | |
1067 | goto fail; | |
1068 | } | |
1069 | ||
1070 | if (page_off >= i_size || | |
1071 | (pos_in_page == 0 && (pos+len) >= i_size && | |
1072 | end_in_page - pos_in_page != PAGE_CACHE_SIZE)) { | |
1073 | dout(" zeroing %p 0 - %d and %d - %d\n", | |
1074 | page, pos_in_page, end_in_page, (int)PAGE_CACHE_SIZE); | |
1075 | zero_user_segments(page, | |
1076 | 0, pos_in_page, | |
1077 | end_in_page, PAGE_CACHE_SIZE); | |
1078 | return 0; | |
1079 | } | |
1080 | ||
1081 | /* we need to read it. */ | |
1082 | up_read(&mdsc->snap_rwsem); | |
1083 | r = readpage_nounlock(file, page); | |
1084 | if (r < 0) | |
1085 | goto fail_nosnap; | |
1086 | goto retry_locked; | |
1087 | ||
1088 | fail: | |
1089 | up_read(&mdsc->snap_rwsem); | |
1090 | fail_nosnap: | |
1091 | unlock_page(page); | |
1092 | return r; | |
1093 | } | |
1094 | ||
4af6b225 YS |
1095 | /* |
1096 | * We are only allowed to write into/dirty the page if the page is | |
1097 | * clean, or already dirty within the same snap context. | |
1098 | */ | |
1099 | static int ceph_write_begin(struct file *file, struct address_space *mapping, | |
1100 | loff_t pos, unsigned len, unsigned flags, | |
1101 | struct page **pagep, void **fsdata) | |
1102 | { | |
496ad9aa | 1103 | struct inode *inode = file_inode(file); |
4af6b225 YS |
1104 | struct page *page; |
1105 | pgoff_t index = pos >> PAGE_CACHE_SHIFT; | |
7971bd92 | 1106 | int r; |
4af6b225 YS |
1107 | |
1108 | do { | |
8f883c24 | 1109 | /* get a page */ |
4af6b225 | 1110 | page = grab_cache_page_write_begin(mapping, index, 0); |
7971bd92 SW |
1111 | if (!page) |
1112 | return -ENOMEM; | |
1113 | *pagep = page; | |
4af6b225 YS |
1114 | |
1115 | dout("write_begin file %p inode %p page %p %d~%d\n", file, | |
213c99ee | 1116 | inode, page, (int)pos, (int)len); |
4af6b225 YS |
1117 | |
1118 | r = ceph_update_writeable_page(file, pos, len, page); | |
1119 | } while (r == -EAGAIN); | |
1120 | ||
1121 | return r; | |
1122 | } | |
1123 | ||
1d3576fd SW |
1124 | /* |
1125 | * we don't do anything in here that simple_write_end doesn't do | |
1126 | * except adjust dirty page accounting and drop read lock on | |
1127 | * mdsc->snap_rwsem. | |
1128 | */ | |
1129 | static int ceph_write_end(struct file *file, struct address_space *mapping, | |
1130 | loff_t pos, unsigned len, unsigned copied, | |
1131 | struct page *page, void *fsdata) | |
1132 | { | |
496ad9aa | 1133 | struct inode *inode = file_inode(file); |
3d14c5d2 YS |
1134 | struct ceph_fs_client *fsc = ceph_inode_to_client(inode); |
1135 | struct ceph_mds_client *mdsc = fsc->mdsc; | |
1d3576fd SW |
1136 | unsigned from = pos & (PAGE_CACHE_SIZE - 1); |
1137 | int check_cap = 0; | |
1138 | ||
1139 | dout("write_end file %p inode %p page %p %d~%d (%d)\n", file, | |
1140 | inode, page, (int)pos, (int)copied, (int)len); | |
1141 | ||
1142 | /* zero the stale part of the page if we did a short copy */ | |
1143 | if (copied < len) | |
1144 | zero_user_segment(page, from+copied, len); | |
1145 | ||
1146 | /* did file size increase? */ | |
1147 | /* (no need for i_size_read(); we caller holds i_mutex */ | |
1148 | if (pos+copied > inode->i_size) | |
1149 | check_cap = ceph_inode_set_size(inode, pos+copied); | |
1150 | ||
1151 | if (!PageUptodate(page)) | |
1152 | SetPageUptodate(page); | |
1153 | ||
1154 | set_page_dirty(page); | |
1155 | ||
1156 | unlock_page(page); | |
1157 | up_read(&mdsc->snap_rwsem); | |
1158 | page_cache_release(page); | |
1159 | ||
1160 | if (check_cap) | |
1161 | ceph_check_caps(ceph_inode(inode), CHECK_CAPS_AUTHONLY, NULL); | |
1162 | ||
1163 | return copied; | |
1164 | } | |
1165 | ||
1166 | /* | |
1167 | * we set .direct_IO to indicate direct io is supported, but since we | |
1168 | * intercept O_DIRECT reads and writes early, this function should | |
1169 | * never get called. | |
1170 | */ | |
1171 | static ssize_t ceph_direct_io(int rw, struct kiocb *iocb, | |
1172 | const struct iovec *iov, | |
1173 | loff_t pos, unsigned long nr_segs) | |
1174 | { | |
1175 | WARN_ON(1); | |
1176 | return -EINVAL; | |
1177 | } | |
1178 | ||
1179 | const struct address_space_operations ceph_aops = { | |
1180 | .readpage = ceph_readpage, | |
1181 | .readpages = ceph_readpages, | |
1182 | .writepage = ceph_writepage, | |
1183 | .writepages = ceph_writepages_start, | |
1184 | .write_begin = ceph_write_begin, | |
1185 | .write_end = ceph_write_end, | |
1186 | .set_page_dirty = ceph_set_page_dirty, | |
1187 | .invalidatepage = ceph_invalidatepage, | |
1188 | .releasepage = ceph_releasepage, | |
1189 | .direct_IO = ceph_direct_io, | |
1190 | }; | |
1191 | ||
1192 | ||
1193 | /* | |
1194 | * vm ops | |
1195 | */ | |
1196 | ||
1197 | /* | |
1198 | * Reuse write_begin here for simplicity. | |
1199 | */ | |
1200 | static int ceph_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) | |
1201 | { | |
496ad9aa | 1202 | struct inode *inode = file_inode(vma->vm_file); |
1d3576fd | 1203 | struct page *page = vmf->page; |
3d14c5d2 | 1204 | struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc; |
6285bc23 | 1205 | loff_t off = page_offset(page); |
1d3576fd | 1206 | loff_t size, len; |
1d3576fd SW |
1207 | int ret; |
1208 | ||
3ca9c3bd JK |
1209 | /* Update time before taking page lock */ |
1210 | file_update_time(vma->vm_file); | |
1211 | ||
1d3576fd SW |
1212 | size = i_size_read(inode); |
1213 | if (off + PAGE_CACHE_SIZE <= size) | |
1214 | len = PAGE_CACHE_SIZE; | |
1215 | else | |
1216 | len = size & ~PAGE_CACHE_MASK; | |
1217 | ||
1218 | dout("page_mkwrite %p %llu~%llu page %p idx %lu\n", inode, | |
1219 | off, len, page, page->index); | |
4af6b225 YS |
1220 | |
1221 | lock_page(page); | |
1222 | ||
1223 | ret = VM_FAULT_NOPAGE; | |
1224 | if ((off > size) || | |
1225 | (page->mapping != inode->i_mapping)) | |
1226 | goto out; | |
1227 | ||
1228 | ret = ceph_update_writeable_page(vma->vm_file, off, len, page); | |
1229 | if (ret == 0) { | |
1230 | /* success. we'll keep the page locked. */ | |
1d3576fd SW |
1231 | set_page_dirty(page); |
1232 | up_read(&mdsc->snap_rwsem); | |
1d3576fd SW |
1233 | ret = VM_FAULT_LOCKED; |
1234 | } else { | |
4af6b225 YS |
1235 | if (ret == -ENOMEM) |
1236 | ret = VM_FAULT_OOM; | |
1237 | else | |
1238 | ret = VM_FAULT_SIGBUS; | |
1d3576fd | 1239 | } |
4af6b225 | 1240 | out: |
1d3576fd | 1241 | dout("page_mkwrite %p %llu~%llu = %d\n", inode, off, len, ret); |
4af6b225 YS |
1242 | if (ret != VM_FAULT_LOCKED) |
1243 | unlock_page(page); | |
1d3576fd SW |
1244 | return ret; |
1245 | } | |
1246 | ||
1247 | static struct vm_operations_struct ceph_vmops = { | |
1248 | .fault = filemap_fault, | |
1249 | .page_mkwrite = ceph_page_mkwrite, | |
0b173bc4 | 1250 | .remap_pages = generic_file_remap_pages, |
1d3576fd SW |
1251 | }; |
1252 | ||
1253 | int ceph_mmap(struct file *file, struct vm_area_struct *vma) | |
1254 | { | |
1255 | struct address_space *mapping = file->f_mapping; | |
1256 | ||
1257 | if (!mapping->a_ops->readpage) | |
1258 | return -ENOEXEC; | |
1259 | file_accessed(file); | |
1260 | vma->vm_ops = &ceph_vmops; | |
1d3576fd SW |
1261 | return 0; |
1262 | } |