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 | 152 | |
4ce1e9ad AB |
153 | inode = page->mapping->host; |
154 | ||
1d3576fd SW |
155 | /* |
156 | * We can get non-dirty pages here due to races between | |
157 | * set_page_dirty and truncate_complete_page; just spit out a | |
158 | * warning, in case we end up with accounting problems later. | |
159 | */ | |
160 | if (!PageDirty(page)) | |
161 | pr_err("%p invalidatepage %p page not dirty\n", inode, page); | |
162 | ||
569d39fc | 163 | if (offset == 0 && length == PAGE_CACHE_SIZE) |
1d3576fd SW |
164 | ClearPageChecked(page); |
165 | ||
166 | ci = ceph_inode(inode); | |
569d39fc LC |
167 | if (offset == 0 && length == PAGE_CACHE_SIZE) { |
168 | dout("%p invalidatepage %p idx %lu full dirty page\n", | |
169 | inode, page, page->index); | |
1d3576fd SW |
170 | ceph_put_wrbuffer_cap_refs(ci, 1, snapc); |
171 | ceph_put_snap_context(snapc); | |
172 | page->private = 0; | |
173 | ClearPagePrivate(page); | |
174 | } else { | |
569d39fc LC |
175 | dout("%p invalidatepage %p idx %lu partial dirty page %u(%u)\n", |
176 | inode, page, page->index, offset, length); | |
1d3576fd SW |
177 | } |
178 | } | |
179 | ||
180 | /* just a sanity check */ | |
181 | static int ceph_releasepage(struct page *page, gfp_t g) | |
182 | { | |
183 | struct inode *inode = page->mapping ? page->mapping->host : NULL; | |
184 | dout("%p releasepage %p idx %lu\n", inode, page, page->index); | |
185 | WARN_ON(PageDirty(page)); | |
1d3576fd SW |
186 | WARN_ON(PagePrivate(page)); |
187 | return 0; | |
188 | } | |
189 | ||
190 | /* | |
191 | * read a single page, without unlocking it. | |
192 | */ | |
193 | static int readpage_nounlock(struct file *filp, struct page *page) | |
194 | { | |
496ad9aa | 195 | struct inode *inode = file_inode(filp); |
1d3576fd | 196 | struct ceph_inode_info *ci = ceph_inode(inode); |
3d14c5d2 YS |
197 | struct ceph_osd_client *osdc = |
198 | &ceph_inode_to_client(inode)->client->osdc; | |
1d3576fd SW |
199 | int err = 0; |
200 | u64 len = PAGE_CACHE_SIZE; | |
201 | ||
202 | dout("readpage inode %p file %p page %p index %lu\n", | |
203 | inode, filp, page, page->index); | |
204 | err = ceph_osdc_readpages(osdc, ceph_vino(inode), &ci->i_layout, | |
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 | ||
219 | out: | |
220 | return err < 0 ? err : 0; | |
221 | } | |
222 | ||
223 | static int ceph_readpage(struct file *filp, struct page *page) | |
224 | { | |
225 | int r = readpage_nounlock(filp, page); | |
226 | unlock_page(page); | |
227 | return r; | |
228 | } | |
229 | ||
230 | /* | |
7c272194 | 231 | * Finish an async read(ahead) op. |
1d3576fd | 232 | */ |
7c272194 | 233 | static void finish_read(struct ceph_osd_request *req, struct ceph_msg *msg) |
1d3576fd | 234 | { |
7c272194 | 235 | struct inode *inode = req->r_inode; |
87060c10 | 236 | struct ceph_osd_data *osd_data; |
1b83bef2 SW |
237 | int rc = req->r_result; |
238 | int bytes = le32_to_cpu(msg->hdr.data_len); | |
e0c59487 | 239 | int num_pages; |
7c272194 | 240 | int i; |
1d3576fd | 241 | |
7c272194 SW |
242 | dout("finish_read %p req %p rc %d bytes %d\n", inode, req, rc, bytes); |
243 | ||
244 | /* unlock all pages, zeroing any data we didn't read */ | |
406e2c9f | 245 | osd_data = osd_req_op_extent_osd_data(req, 0); |
87060c10 AE |
246 | BUG_ON(osd_data->type != CEPH_OSD_DATA_TYPE_PAGES); |
247 | num_pages = calc_pages_for((u64)osd_data->alignment, | |
248 | (u64)osd_data->length); | |
e0c59487 | 249 | for (i = 0; i < num_pages; i++) { |
87060c10 | 250 | struct page *page = osd_data->pages[i]; |
7c272194 SW |
251 | |
252 | if (bytes < (int)PAGE_CACHE_SIZE) { | |
253 | /* zero (remainder of) page */ | |
254 | int s = bytes < 0 ? 0 : bytes; | |
255 | zero_user_segment(page, s, PAGE_CACHE_SIZE); | |
1d3576fd | 256 | } |
7c272194 SW |
257 | dout("finish_read %p uptodate %p idx %lu\n", inode, page, |
258 | page->index); | |
259 | flush_dcache_page(page); | |
260 | SetPageUptodate(page); | |
261 | unlock_page(page); | |
262 | page_cache_release(page); | |
0fff87ec | 263 | bytes -= PAGE_CACHE_SIZE; |
1d3576fd | 264 | } |
87060c10 | 265 | kfree(osd_data->pages); |
1d3576fd SW |
266 | } |
267 | ||
8884d53d DZ |
268 | static void ceph_unlock_page_vector(struct page **pages, int num_pages) |
269 | { | |
270 | int i; | |
271 | ||
272 | for (i = 0; i < num_pages; i++) | |
273 | unlock_page(pages[i]); | |
274 | } | |
275 | ||
1d3576fd | 276 | /* |
7c272194 SW |
277 | * start an async read(ahead) operation. return nr_pages we submitted |
278 | * a read for on success, or negative error code. | |
1d3576fd | 279 | */ |
0d66a487 | 280 | static int start_read(struct inode *inode, struct list_head *page_list, int max) |
1d3576fd | 281 | { |
3d14c5d2 YS |
282 | struct ceph_osd_client *osdc = |
283 | &ceph_inode_to_client(inode)->client->osdc; | |
7c272194 SW |
284 | struct ceph_inode_info *ci = ceph_inode(inode); |
285 | struct page *page = list_entry(page_list->prev, struct page, lru); | |
acead002 | 286 | struct ceph_vino vino; |
7c272194 SW |
287 | struct ceph_osd_request *req; |
288 | u64 off; | |
1d3576fd | 289 | u64 len; |
7c272194 SW |
290 | int i; |
291 | struct page **pages; | |
292 | pgoff_t next_index; | |
293 | int nr_pages = 0; | |
294 | int ret; | |
1d3576fd | 295 | |
6285bc23 | 296 | off = (u64) page_offset(page); |
1d3576fd | 297 | |
7c272194 SW |
298 | /* count pages */ |
299 | next_index = page->index; | |
300 | list_for_each_entry_reverse(page, page_list, lru) { | |
301 | if (page->index != next_index) | |
302 | break; | |
303 | nr_pages++; | |
304 | next_index++; | |
0d66a487 SW |
305 | if (max && nr_pages == max) |
306 | break; | |
7c272194 | 307 | } |
1d3576fd | 308 | len = nr_pages << PAGE_CACHE_SHIFT; |
7c272194 SW |
309 | dout("start_read %p nr_pages %d is %lld~%lld\n", inode, nr_pages, |
310 | off, len); | |
acead002 AE |
311 | vino = ceph_vino(inode); |
312 | req = ceph_osdc_new_request(osdc, &ci->i_layout, vino, off, &len, | |
79528734 | 313 | 1, CEPH_OSD_OP_READ, |
acead002 | 314 | CEPH_OSD_FLAG_READ, NULL, |
7c272194 | 315 | ci->i_truncate_seq, ci->i_truncate_size, |
acead002 | 316 | false); |
6816282d SW |
317 | if (IS_ERR(req)) |
318 | return PTR_ERR(req); | |
1d3576fd | 319 | |
7c272194 | 320 | /* build page vector */ |
cf7b7e14 | 321 | nr_pages = calc_pages_for(0, len); |
7c272194 SW |
322 | pages = kmalloc(sizeof(*pages) * nr_pages, GFP_NOFS); |
323 | ret = -ENOMEM; | |
324 | if (!pages) | |
325 | goto out; | |
326 | for (i = 0; i < nr_pages; ++i) { | |
327 | page = list_entry(page_list->prev, struct page, lru); | |
328 | BUG_ON(PageLocked(page)); | |
1d3576fd | 329 | list_del(&page->lru); |
7c272194 SW |
330 | |
331 | dout("start_read %p adding %p idx %lu\n", inode, page, | |
332 | page->index); | |
333 | if (add_to_page_cache_lru(page, &inode->i_data, page->index, | |
213c99ee | 334 | GFP_NOFS)) { |
1d3576fd | 335 | page_cache_release(page); |
7c272194 | 336 | dout("start_read %p add_to_page_cache failed %p\n", |
1d3576fd | 337 | inode, page); |
7c272194 SW |
338 | nr_pages = i; |
339 | goto out_pages; | |
1d3576fd | 340 | } |
7c272194 | 341 | pages[i] = page; |
1d3576fd | 342 | } |
406e2c9f | 343 | osd_req_op_extent_osd_data_pages(req, 0, pages, len, 0, false, false); |
7c272194 SW |
344 | req->r_callback = finish_read; |
345 | req->r_inode = inode; | |
346 | ||
79528734 | 347 | ceph_osdc_build_request(req, off, NULL, vino.snap, NULL); |
02ee07d3 | 348 | |
7c272194 SW |
349 | dout("start_read %p starting %p %lld~%lld\n", inode, req, off, len); |
350 | ret = ceph_osdc_start_request(osdc, req, false); | |
351 | if (ret < 0) | |
352 | goto out_pages; | |
353 | ceph_osdc_put_request(req); | |
354 | return nr_pages; | |
355 | ||
356 | out_pages: | |
8884d53d | 357 | ceph_unlock_page_vector(pages, nr_pages); |
7c272194 | 358 | ceph_release_page_vector(pages, nr_pages); |
7c272194 SW |
359 | out: |
360 | ceph_osdc_put_request(req); | |
361 | return ret; | |
362 | } | |
1d3576fd | 363 | |
7c272194 SW |
364 | |
365 | /* | |
366 | * Read multiple pages. Leave pages we don't read + unlock in page_list; | |
367 | * the caller (VM) cleans them up. | |
368 | */ | |
369 | static int ceph_readpages(struct file *file, struct address_space *mapping, | |
370 | struct list_head *page_list, unsigned nr_pages) | |
371 | { | |
496ad9aa | 372 | struct inode *inode = file_inode(file); |
0d66a487 | 373 | struct ceph_fs_client *fsc = ceph_inode_to_client(inode); |
7c272194 | 374 | int rc = 0; |
0d66a487 SW |
375 | int max = 0; |
376 | ||
377 | if (fsc->mount_options->rsize >= PAGE_CACHE_SIZE) | |
378 | max = (fsc->mount_options->rsize + PAGE_CACHE_SIZE - 1) | |
379 | >> PAGE_SHIFT; | |
7c272194 | 380 | |
2794a82a AE |
381 | dout("readpages %p file %p nr_pages %d max %d\n", inode, |
382 | file, nr_pages, | |
0d66a487 | 383 | max); |
7c272194 | 384 | while (!list_empty(page_list)) { |
0d66a487 | 385 | rc = start_read(inode, page_list, max); |
7c272194 SW |
386 | if (rc < 0) |
387 | goto out; | |
388 | BUG_ON(rc == 0); | |
389 | } | |
1d3576fd | 390 | out: |
7c272194 | 391 | dout("readpages %p file %p ret %d\n", inode, file, rc); |
1d3576fd SW |
392 | return rc; |
393 | } | |
394 | ||
395 | /* | |
396 | * Get ref for the oldest snapc for an inode with dirty data... that is, the | |
397 | * only snap context we are allowed to write back. | |
1d3576fd | 398 | */ |
6298a337 SW |
399 | static struct ceph_snap_context *get_oldest_context(struct inode *inode, |
400 | u64 *snap_size) | |
1d3576fd SW |
401 | { |
402 | struct ceph_inode_info *ci = ceph_inode(inode); | |
403 | struct ceph_snap_context *snapc = NULL; | |
404 | struct ceph_cap_snap *capsnap = NULL; | |
405 | ||
be655596 | 406 | spin_lock(&ci->i_ceph_lock); |
1d3576fd SW |
407 | list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) { |
408 | dout(" cap_snap %p snapc %p has %d dirty pages\n", capsnap, | |
409 | capsnap->context, capsnap->dirty_pages); | |
410 | if (capsnap->dirty_pages) { | |
411 | snapc = ceph_get_snap_context(capsnap->context); | |
412 | if (snap_size) | |
413 | *snap_size = capsnap->size; | |
414 | break; | |
415 | } | |
416 | } | |
7d8cb26d | 417 | if (!snapc && ci->i_wrbuffer_ref_head) { |
80e755fe | 418 | snapc = ceph_get_snap_context(ci->i_head_snapc); |
1d3576fd SW |
419 | dout(" head snapc %p has %d dirty pages\n", |
420 | snapc, ci->i_wrbuffer_ref_head); | |
421 | } | |
be655596 | 422 | spin_unlock(&ci->i_ceph_lock); |
1d3576fd SW |
423 | return snapc; |
424 | } | |
425 | ||
426 | /* | |
427 | * Write a single page, but leave the page locked. | |
428 | * | |
429 | * If we get a write error, set the page error bit, but still adjust the | |
430 | * dirty page accounting (i.e., page is no longer dirty). | |
431 | */ | |
432 | static int writepage_nounlock(struct page *page, struct writeback_control *wbc) | |
433 | { | |
434 | struct inode *inode; | |
435 | struct ceph_inode_info *ci; | |
3d14c5d2 | 436 | struct ceph_fs_client *fsc; |
1d3576fd | 437 | struct ceph_osd_client *osdc; |
6298a337 | 438 | struct ceph_snap_context *snapc, *oldest; |
fc2744aa | 439 | loff_t page_off = page_offset(page); |
2baba250 | 440 | long writeback_stat; |
fc2744aa YZ |
441 | u64 truncate_size, snap_size = 0; |
442 | u32 truncate_seq; | |
443 | int err = 0, len = PAGE_CACHE_SIZE; | |
1d3576fd SW |
444 | |
445 | dout("writepage %p idx %lu\n", page, page->index); | |
446 | ||
447 | if (!page->mapping || !page->mapping->host) { | |
448 | dout("writepage %p - no mapping\n", page); | |
449 | return -EFAULT; | |
450 | } | |
451 | inode = page->mapping->host; | |
452 | ci = ceph_inode(inode); | |
3d14c5d2 YS |
453 | fsc = ceph_inode_to_client(inode); |
454 | osdc = &fsc->client->osdc; | |
1d3576fd SW |
455 | |
456 | /* verify this is a writeable snap context */ | |
61600ef8 | 457 | snapc = page_snap_context(page); |
1d3576fd SW |
458 | if (snapc == NULL) { |
459 | dout("writepage %p page %p not dirty?\n", inode, page); | |
460 | goto out; | |
461 | } | |
6298a337 SW |
462 | oldest = get_oldest_context(inode, &snap_size); |
463 | if (snapc->seq > oldest->seq) { | |
1d3576fd | 464 | dout("writepage %p page %p snapc %p not writeable - noop\n", |
61600ef8 | 465 | inode, page, snapc); |
1d3576fd SW |
466 | /* we should only noop if called by kswapd */ |
467 | WARN_ON((current->flags & PF_MEMALLOC) == 0); | |
6298a337 | 468 | ceph_put_snap_context(oldest); |
1d3576fd SW |
469 | goto out; |
470 | } | |
6298a337 | 471 | ceph_put_snap_context(oldest); |
1d3576fd | 472 | |
fc2744aa YZ |
473 | spin_lock(&ci->i_ceph_lock); |
474 | truncate_seq = ci->i_truncate_seq; | |
475 | truncate_size = ci->i_truncate_size; | |
476 | if (!snap_size) | |
477 | snap_size = i_size_read(inode); | |
478 | spin_unlock(&ci->i_ceph_lock); | |
479 | ||
1d3576fd | 480 | /* is this a partial page at end of file? */ |
fc2744aa YZ |
481 | if (page_off >= snap_size) { |
482 | dout("%p page eof %llu\n", page, snap_size); | |
483 | goto out; | |
484 | } | |
485 | if (snap_size < page_off + len) | |
486 | len = snap_size - page_off; | |
1d3576fd | 487 | |
ae00d4f3 SW |
488 | dout("writepage %p page %p index %lu on %llu~%u snapc %p\n", |
489 | inode, page, page->index, page_off, len, snapc); | |
1d3576fd | 490 | |
3d14c5d2 | 491 | writeback_stat = atomic_long_inc_return(&fsc->writeback_count); |
2baba250 | 492 | if (writeback_stat > |
3d14c5d2 YS |
493 | CONGESTION_ON_THRESH(fsc->mount_options->congestion_kb)) |
494 | set_bdi_congested(&fsc->backing_dev_info, BLK_RW_ASYNC); | |
2baba250 | 495 | |
1d3576fd SW |
496 | set_page_writeback(page); |
497 | err = ceph_osdc_writepages(osdc, ceph_vino(inode), | |
498 | &ci->i_layout, snapc, | |
499 | page_off, len, | |
fc2744aa | 500 | truncate_seq, truncate_size, |
24808826 | 501 | &inode->i_mtime, &page, 1); |
1d3576fd SW |
502 | if (err < 0) { |
503 | dout("writepage setting page/mapping error %d %p\n", err, page); | |
504 | SetPageError(page); | |
505 | mapping_set_error(&inode->i_data, err); | |
506 | if (wbc) | |
507 | wbc->pages_skipped++; | |
508 | } else { | |
509 | dout("writepage cleaned page %p\n", page); | |
510 | err = 0; /* vfs expects us to return 0 */ | |
511 | } | |
512 | page->private = 0; | |
513 | ClearPagePrivate(page); | |
514 | end_page_writeback(page); | |
515 | ceph_put_wrbuffer_cap_refs(ci, 1, snapc); | |
6298a337 | 516 | ceph_put_snap_context(snapc); /* page's reference */ |
1d3576fd SW |
517 | out: |
518 | return err; | |
519 | } | |
520 | ||
521 | static int ceph_writepage(struct page *page, struct writeback_control *wbc) | |
522 | { | |
dbd646a8 YS |
523 | int err; |
524 | struct inode *inode = page->mapping->host; | |
525 | BUG_ON(!inode); | |
70b666c3 | 526 | ihold(inode); |
dbd646a8 | 527 | err = writepage_nounlock(page, wbc); |
1d3576fd | 528 | unlock_page(page); |
dbd646a8 | 529 | iput(inode); |
1d3576fd SW |
530 | return err; |
531 | } | |
532 | ||
533 | ||
534 | /* | |
535 | * lame release_pages helper. release_pages() isn't exported to | |
536 | * modules. | |
537 | */ | |
538 | static void ceph_release_pages(struct page **pages, int num) | |
539 | { | |
540 | struct pagevec pvec; | |
541 | int i; | |
542 | ||
543 | pagevec_init(&pvec, 0); | |
544 | for (i = 0; i < num; i++) { | |
545 | if (pagevec_add(&pvec, pages[i]) == 0) | |
546 | pagevec_release(&pvec); | |
547 | } | |
548 | pagevec_release(&pvec); | |
549 | } | |
550 | ||
551 | ||
552 | /* | |
553 | * async writeback completion handler. | |
554 | * | |
555 | * If we get an error, set the mapping error bit, but not the individual | |
556 | * page error bits. | |
557 | */ | |
558 | static void writepages_finish(struct ceph_osd_request *req, | |
559 | struct ceph_msg *msg) | |
560 | { | |
561 | struct inode *inode = req->r_inode; | |
1d3576fd | 562 | struct ceph_inode_info *ci = ceph_inode(inode); |
87060c10 | 563 | struct ceph_osd_data *osd_data; |
1d3576fd | 564 | unsigned wrote; |
1d3576fd | 565 | struct page *page; |
e0c59487 | 566 | int num_pages; |
1d3576fd SW |
567 | int i; |
568 | struct ceph_snap_context *snapc = req->r_snapc; | |
569 | struct address_space *mapping = inode->i_mapping; | |
1b83bef2 | 570 | int rc = req->r_result; |
79528734 | 571 | u64 bytes = req->r_ops[0].extent.length; |
3d14c5d2 | 572 | struct ceph_fs_client *fsc = ceph_inode_to_client(inode); |
2baba250 | 573 | long writeback_stat; |
7ff899da | 574 | unsigned issued = ceph_caps_issued(ci); |
1d3576fd | 575 | |
406e2c9f | 576 | osd_data = osd_req_op_extent_osd_data(req, 0); |
87060c10 AE |
577 | BUG_ON(osd_data->type != CEPH_OSD_DATA_TYPE_PAGES); |
578 | num_pages = calc_pages_for((u64)osd_data->alignment, | |
579 | (u64)osd_data->length); | |
1d3576fd | 580 | if (rc >= 0) { |
79788c69 SW |
581 | /* |
582 | * Assume we wrote the pages we originally sent. The | |
583 | * osd might reply with fewer pages if our writeback | |
584 | * raced with a truncation and was adjusted at the osd, | |
585 | * so don't believe the reply. | |
586 | */ | |
e0c59487 | 587 | wrote = num_pages; |
1d3576fd SW |
588 | } else { |
589 | wrote = 0; | |
590 | mapping_set_error(mapping, rc); | |
591 | } | |
592 | dout("writepages_finish %p rc %d bytes %llu wrote %d (pages)\n", | |
593 | inode, rc, bytes, wrote); | |
594 | ||
595 | /* clean all pages */ | |
e0c59487 | 596 | for (i = 0; i < num_pages; i++) { |
87060c10 | 597 | page = osd_data->pages[i]; |
1d3576fd SW |
598 | BUG_ON(!page); |
599 | WARN_ON(!PageUptodate(page)); | |
600 | ||
2baba250 | 601 | writeback_stat = |
3d14c5d2 | 602 | atomic_long_dec_return(&fsc->writeback_count); |
2baba250 | 603 | if (writeback_stat < |
3d14c5d2 YS |
604 | CONGESTION_OFF_THRESH(fsc->mount_options->congestion_kb)) |
605 | clear_bdi_congested(&fsc->backing_dev_info, | |
2baba250 YS |
606 | BLK_RW_ASYNC); |
607 | ||
61600ef8 | 608 | ceph_put_snap_context(page_snap_context(page)); |
1d3576fd SW |
609 | page->private = 0; |
610 | ClearPagePrivate(page); | |
1d3576fd SW |
611 | dout("unlocking %d %p\n", i, page); |
612 | end_page_writeback(page); | |
e63dc5c7 YS |
613 | |
614 | /* | |
615 | * We lost the cache cap, need to truncate the page before | |
616 | * it is unlocked, otherwise we'd truncate it later in the | |
617 | * page truncation thread, possibly losing some data that | |
618 | * raced its way in | |
619 | */ | |
2962507c | 620 | if ((issued & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) == 0) |
e63dc5c7 YS |
621 | generic_error_remove_page(inode->i_mapping, page); |
622 | ||
1d3576fd SW |
623 | unlock_page(page); |
624 | } | |
625 | dout("%p wrote+cleaned %d pages\n", inode, wrote); | |
e0c59487 | 626 | ceph_put_wrbuffer_cap_refs(ci, num_pages, snapc); |
1d3576fd | 627 | |
87060c10 AE |
628 | ceph_release_pages(osd_data->pages, num_pages); |
629 | if (osd_data->pages_from_pool) | |
630 | mempool_free(osd_data->pages, | |
640ef79d | 631 | ceph_sb_to_client(inode->i_sb)->wb_pagevec_pool); |
1d3576fd | 632 | else |
87060c10 | 633 | kfree(osd_data->pages); |
1d3576fd SW |
634 | ceph_osdc_put_request(req); |
635 | } | |
636 | ||
1d3576fd SW |
637 | /* |
638 | * initiate async writeback | |
639 | */ | |
640 | static int ceph_writepages_start(struct address_space *mapping, | |
641 | struct writeback_control *wbc) | |
642 | { | |
643 | struct inode *inode = mapping->host; | |
1d3576fd | 644 | struct ceph_inode_info *ci = ceph_inode(inode); |
fc2744aa YZ |
645 | struct ceph_fs_client *fsc = ceph_inode_to_client(inode); |
646 | struct ceph_vino vino = ceph_vino(inode); | |
1d3576fd SW |
647 | pgoff_t index, start, end; |
648 | int range_whole = 0; | |
649 | int should_loop = 1; | |
650 | pgoff_t max_pages = 0, max_pages_ever = 0; | |
80e755fe | 651 | struct ceph_snap_context *snapc = NULL, *last_snapc = NULL, *pgsnapc; |
1d3576fd SW |
652 | struct pagevec pvec; |
653 | int done = 0; | |
654 | int rc = 0; | |
655 | unsigned wsize = 1 << inode->i_blkbits; | |
656 | struct ceph_osd_request *req = NULL; | |
657 | int do_sync; | |
fc2744aa YZ |
658 | u64 truncate_size, snap_size; |
659 | u32 truncate_seq; | |
1d3576fd SW |
660 | |
661 | /* | |
662 | * Include a 'sync' in the OSD request if this is a data | |
663 | * integrity write (e.g., O_SYNC write or fsync()), or if our | |
664 | * cap is being revoked. | |
665 | */ | |
c62988ec | 666 | if ((wbc->sync_mode == WB_SYNC_ALL) || |
667 | ceph_caps_revoking(ci, CEPH_CAP_FILE_BUFFER)) | |
1d3576fd SW |
668 | do_sync = 1; |
669 | dout("writepages_start %p dosync=%d (mode=%s)\n", | |
670 | inode, do_sync, | |
671 | wbc->sync_mode == WB_SYNC_NONE ? "NONE" : | |
672 | (wbc->sync_mode == WB_SYNC_ALL ? "ALL" : "HOLD")); | |
673 | ||
3d14c5d2 | 674 | if (fsc->mount_state == CEPH_MOUNT_SHUTDOWN) { |
1d3576fd SW |
675 | pr_warning("writepage_start %p on forced umount\n", inode); |
676 | return -EIO; /* we're in a forced umount, don't write! */ | |
677 | } | |
3d14c5d2 YS |
678 | if (fsc->mount_options->wsize && fsc->mount_options->wsize < wsize) |
679 | wsize = fsc->mount_options->wsize; | |
1d3576fd SW |
680 | if (wsize < PAGE_CACHE_SIZE) |
681 | wsize = PAGE_CACHE_SIZE; | |
682 | max_pages_ever = wsize >> PAGE_CACHE_SHIFT; | |
683 | ||
684 | pagevec_init(&pvec, 0); | |
685 | ||
1d3576fd SW |
686 | /* where to start/end? */ |
687 | if (wbc->range_cyclic) { | |
688 | start = mapping->writeback_index; /* Start from prev offset */ | |
689 | end = -1; | |
690 | dout(" cyclic, start at %lu\n", start); | |
691 | } else { | |
692 | start = wbc->range_start >> PAGE_CACHE_SHIFT; | |
693 | end = wbc->range_end >> PAGE_CACHE_SHIFT; | |
694 | if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) | |
695 | range_whole = 1; | |
696 | should_loop = 0; | |
697 | dout(" not cyclic, %lu to %lu\n", start, end); | |
698 | } | |
699 | index = start; | |
700 | ||
701 | retry: | |
702 | /* find oldest snap context with dirty data */ | |
703 | ceph_put_snap_context(snapc); | |
1ac0fc8a | 704 | snap_size = 0; |
1d3576fd SW |
705 | snapc = get_oldest_context(inode, &snap_size); |
706 | if (!snapc) { | |
707 | /* hmm, why does writepages get called when there | |
708 | is no dirty data? */ | |
709 | dout(" no snap context with dirty data?\n"); | |
710 | goto out; | |
711 | } | |
1ac0fc8a YZ |
712 | if (snap_size == 0) |
713 | snap_size = i_size_read(inode); | |
1d3576fd SW |
714 | dout(" oldest snapc is %p seq %lld (%d snaps)\n", |
715 | snapc, snapc->seq, snapc->num_snaps); | |
fc2744aa YZ |
716 | |
717 | spin_lock(&ci->i_ceph_lock); | |
718 | truncate_seq = ci->i_truncate_seq; | |
719 | truncate_size = ci->i_truncate_size; | |
720 | if (!snap_size) | |
721 | snap_size = i_size_read(inode); | |
722 | spin_unlock(&ci->i_ceph_lock); | |
723 | ||
1d3576fd SW |
724 | if (last_snapc && snapc != last_snapc) { |
725 | /* if we switched to a newer snapc, restart our scan at the | |
726 | * start of the original file range. */ | |
727 | dout(" snapc differs from last pass, restarting at %lu\n", | |
728 | index); | |
729 | index = start; | |
730 | } | |
731 | last_snapc = snapc; | |
732 | ||
733 | while (!done && index <= end) { | |
e5975c7c | 734 | int num_ops = do_sync ? 2 : 1; |
1d3576fd SW |
735 | unsigned i; |
736 | int first; | |
737 | pgoff_t next; | |
738 | int pvec_pages, locked_pages; | |
e5975c7c AE |
739 | struct page **pages = NULL; |
740 | mempool_t *pool = NULL; /* Becomes non-null if mempool used */ | |
1d3576fd SW |
741 | struct page *page; |
742 | int want; | |
743 | u64 offset, len; | |
2baba250 | 744 | long writeback_stat; |
1d3576fd SW |
745 | |
746 | next = 0; | |
747 | locked_pages = 0; | |
748 | max_pages = max_pages_ever; | |
749 | ||
750 | get_more_pages: | |
751 | first = -1; | |
752 | want = min(end - index, | |
753 | min((pgoff_t)PAGEVEC_SIZE, | |
754 | max_pages - (pgoff_t)locked_pages) - 1) | |
755 | + 1; | |
756 | pvec_pages = pagevec_lookup_tag(&pvec, mapping, &index, | |
757 | PAGECACHE_TAG_DIRTY, | |
758 | want); | |
759 | dout("pagevec_lookup_tag got %d\n", pvec_pages); | |
760 | if (!pvec_pages && !locked_pages) | |
761 | break; | |
762 | for (i = 0; i < pvec_pages && locked_pages < max_pages; i++) { | |
763 | page = pvec.pages[i]; | |
764 | dout("? %p idx %lu\n", page, page->index); | |
765 | if (locked_pages == 0) | |
766 | lock_page(page); /* first page */ | |
767 | else if (!trylock_page(page)) | |
768 | break; | |
769 | ||
770 | /* only dirty pages, or our accounting breaks */ | |
771 | if (unlikely(!PageDirty(page)) || | |
772 | unlikely(page->mapping != mapping)) { | |
773 | dout("!dirty or !mapping %p\n", page); | |
774 | unlock_page(page); | |
775 | break; | |
776 | } | |
777 | if (!wbc->range_cyclic && page->index > end) { | |
778 | dout("end of range %p\n", page); | |
779 | done = 1; | |
780 | unlock_page(page); | |
781 | break; | |
782 | } | |
783 | if (next && (page->index != next)) { | |
784 | dout("not consecutive %p\n", page); | |
785 | unlock_page(page); | |
786 | break; | |
787 | } | |
788 | if (wbc->sync_mode != WB_SYNC_NONE) { | |
789 | dout("waiting on writeback %p\n", page); | |
790 | wait_on_page_writeback(page); | |
791 | } | |
1ac0fc8a YZ |
792 | if (page_offset(page) >= snap_size) { |
793 | dout("%p page eof %llu\n", page, snap_size); | |
1d3576fd SW |
794 | done = 1; |
795 | unlock_page(page); | |
796 | break; | |
797 | } | |
798 | if (PageWriteback(page)) { | |
799 | dout("%p under writeback\n", page); | |
800 | unlock_page(page); | |
801 | break; | |
802 | } | |
803 | ||
804 | /* only if matching snap context */ | |
61600ef8 | 805 | pgsnapc = page_snap_context(page); |
80e755fe SW |
806 | if (pgsnapc->seq > snapc->seq) { |
807 | dout("page snapc %p %lld > oldest %p %lld\n", | |
808 | pgsnapc, pgsnapc->seq, snapc, snapc->seq); | |
1d3576fd SW |
809 | unlock_page(page); |
810 | if (!locked_pages) | |
811 | continue; /* keep looking for snap */ | |
812 | break; | |
813 | } | |
814 | ||
815 | if (!clear_page_dirty_for_io(page)) { | |
816 | dout("%p !clear_page_dirty_for_io\n", page); | |
817 | unlock_page(page); | |
818 | break; | |
819 | } | |
820 | ||
e5975c7c AE |
821 | /* |
822 | * We have something to write. If this is | |
823 | * the first locked page this time through, | |
824 | * allocate an osd request and a page array | |
825 | * that it will use. | |
826 | */ | |
1d3576fd | 827 | if (locked_pages == 0) { |
e5975c7c | 828 | BUG_ON(pages); |
1d3576fd | 829 | /* prepare async write request */ |
e5975c7c | 830 | offset = (u64)page_offset(page); |
1d3576fd | 831 | len = wsize; |
fc2744aa YZ |
832 | req = ceph_osdc_new_request(&fsc->client->osdc, |
833 | &ci->i_layout, vino, | |
834 | offset, &len, num_ops, | |
835 | CEPH_OSD_OP_WRITE, | |
836 | CEPH_OSD_FLAG_WRITE | | |
837 | CEPH_OSD_FLAG_ONDISK, | |
838 | snapc, truncate_seq, | |
839 | truncate_size, true); | |
6816282d SW |
840 | if (IS_ERR(req)) { |
841 | rc = PTR_ERR(req); | |
8c71897b HC |
842 | unlock_page(page); |
843 | break; | |
844 | } | |
845 | ||
88486957 AE |
846 | req->r_callback = writepages_finish; |
847 | req->r_inode = inode; | |
848 | ||
849 | max_pages = calc_pages_for(0, (u64)len); | |
fc2744aa YZ |
850 | pages = kmalloc(max_pages * sizeof (*pages), |
851 | GFP_NOFS); | |
88486957 AE |
852 | if (!pages) { |
853 | pool = fsc->wb_pagevec_pool; | |
88486957 | 854 | pages = mempool_alloc(pool, GFP_NOFS); |
e5975c7c | 855 | BUG_ON(!pages); |
88486957 | 856 | } |
1d3576fd SW |
857 | } |
858 | ||
859 | /* note position of first page in pvec */ | |
860 | if (first < 0) | |
861 | first = i; | |
862 | dout("%p will write page %p idx %lu\n", | |
863 | inode, page, page->index); | |
2baba250 | 864 | |
213c99ee | 865 | writeback_stat = |
3d14c5d2 | 866 | atomic_long_inc_return(&fsc->writeback_count); |
213c99ee | 867 | if (writeback_stat > CONGESTION_ON_THRESH( |
3d14c5d2 YS |
868 | fsc->mount_options->congestion_kb)) { |
869 | set_bdi_congested(&fsc->backing_dev_info, | |
213c99ee | 870 | BLK_RW_ASYNC); |
2baba250 YS |
871 | } |
872 | ||
1d3576fd | 873 | set_page_writeback(page); |
e5975c7c | 874 | pages[locked_pages] = page; |
1d3576fd SW |
875 | locked_pages++; |
876 | next = page->index + 1; | |
877 | } | |
878 | ||
879 | /* did we get anything? */ | |
880 | if (!locked_pages) | |
881 | goto release_pvec_pages; | |
882 | if (i) { | |
883 | int j; | |
884 | BUG_ON(!locked_pages || first < 0); | |
885 | ||
886 | if (pvec_pages && i == pvec_pages && | |
887 | locked_pages < max_pages) { | |
888 | dout("reached end pvec, trying for more\n"); | |
889 | pagevec_reinit(&pvec); | |
890 | goto get_more_pages; | |
891 | } | |
892 | ||
893 | /* shift unused pages over in the pvec... we | |
894 | * will need to release them below. */ | |
895 | for (j = i; j < pvec_pages; j++) { | |
896 | dout(" pvec leftover page %p\n", | |
897 | pvec.pages[j]); | |
898 | pvec.pages[j-i+first] = pvec.pages[j]; | |
899 | } | |
900 | pvec.nr -= i-first; | |
901 | } | |
902 | ||
e5975c7c AE |
903 | /* Format the osd request message and submit the write */ |
904 | ||
905 | offset = page_offset(pages[0]); | |
1ac0fc8a | 906 | len = min(snap_size - offset, |
1d3576fd SW |
907 | (u64)locked_pages << PAGE_CACHE_SHIFT); |
908 | dout("writepages got %d pages at %llu~%llu\n", | |
909 | locked_pages, offset, len); | |
910 | ||
406e2c9f | 911 | osd_req_op_extent_osd_data_pages(req, 0, pages, len, 0, |
a4ce40a9 | 912 | !!pool, false); |
e5975c7c AE |
913 | |
914 | pages = NULL; /* request message now owns the pages array */ | |
915 | pool = NULL; | |
916 | ||
917 | /* Update the write op length in case we changed it */ | |
918 | ||
c99d2d4a | 919 | osd_req_op_extent_update(req, 0, len); |
e5975c7c AE |
920 | |
921 | vino = ceph_vino(inode); | |
79528734 AE |
922 | ceph_osdc_build_request(req, offset, snapc, vino.snap, |
923 | &inode->i_mtime); | |
1d3576fd | 924 | |
9d6fcb08 SW |
925 | rc = ceph_osdc_start_request(&fsc->client->osdc, req, true); |
926 | BUG_ON(rc); | |
1d3576fd SW |
927 | req = NULL; |
928 | ||
929 | /* continue? */ | |
930 | index = next; | |
931 | wbc->nr_to_write -= locked_pages; | |
932 | if (wbc->nr_to_write <= 0) | |
933 | done = 1; | |
934 | ||
935 | release_pvec_pages: | |
936 | dout("pagevec_release on %d pages (%p)\n", (int)pvec.nr, | |
937 | pvec.nr ? pvec.pages[0] : NULL); | |
938 | pagevec_release(&pvec); | |
939 | ||
940 | if (locked_pages && !done) | |
941 | goto retry; | |
942 | } | |
943 | ||
944 | if (should_loop && !done) { | |
945 | /* more to do; loop back to beginning of file */ | |
946 | dout("writepages looping back to beginning of file\n"); | |
947 | should_loop = 0; | |
948 | index = 0; | |
949 | goto retry; | |
950 | } | |
951 | ||
952 | if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0)) | |
953 | mapping->writeback_index = index; | |
954 | ||
955 | out: | |
956 | if (req) | |
957 | ceph_osdc_put_request(req); | |
1d3576fd SW |
958 | ceph_put_snap_context(snapc); |
959 | dout("writepages done, rc = %d\n", rc); | |
1d3576fd SW |
960 | return rc; |
961 | } | |
962 | ||
963 | ||
964 | ||
965 | /* | |
966 | * See if a given @snapc is either writeable, or already written. | |
967 | */ | |
968 | static int context_is_writeable_or_written(struct inode *inode, | |
969 | struct ceph_snap_context *snapc) | |
970 | { | |
971 | struct ceph_snap_context *oldest = get_oldest_context(inode, NULL); | |
6298a337 SW |
972 | int ret = !oldest || snapc->seq <= oldest->seq; |
973 | ||
974 | ceph_put_snap_context(oldest); | |
975 | return ret; | |
1d3576fd SW |
976 | } |
977 | ||
978 | /* | |
979 | * We are only allowed to write into/dirty the page if the page is | |
980 | * clean, or already dirty within the same snap context. | |
8f883c24 SW |
981 | * |
982 | * called with page locked. | |
983 | * return success with page locked, | |
984 | * or any failure (incl -EAGAIN) with page unlocked. | |
1d3576fd | 985 | */ |
4af6b225 YS |
986 | static int ceph_update_writeable_page(struct file *file, |
987 | loff_t pos, unsigned len, | |
988 | struct page *page) | |
1d3576fd | 989 | { |
496ad9aa | 990 | struct inode *inode = file_inode(file); |
1d3576fd | 991 | struct ceph_inode_info *ci = ceph_inode(inode); |
3d14c5d2 | 992 | struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc; |
1d3576fd SW |
993 | loff_t page_off = pos & PAGE_CACHE_MASK; |
994 | int pos_in_page = pos & ~PAGE_CACHE_MASK; | |
995 | int end_in_page = pos_in_page + len; | |
996 | loff_t i_size; | |
1d3576fd | 997 | int r; |
80e755fe | 998 | struct ceph_snap_context *snapc, *oldest; |
1d3576fd | 999 | |
1d3576fd SW |
1000 | retry_locked: |
1001 | /* writepages currently holds page lock, but if we change that later, */ | |
1002 | wait_on_page_writeback(page); | |
1003 | ||
1004 | /* check snap context */ | |
1005 | BUG_ON(!ci->i_snap_realm); | |
1006 | down_read(&mdsc->snap_rwsem); | |
1007 | BUG_ON(!ci->i_snap_realm->cached_context); | |
61600ef8 | 1008 | snapc = page_snap_context(page); |
80e755fe | 1009 | if (snapc && snapc != ci->i_head_snapc) { |
1d3576fd SW |
1010 | /* |
1011 | * this page is already dirty in another (older) snap | |
1012 | * context! is it writeable now? | |
1013 | */ | |
80e755fe | 1014 | oldest = get_oldest_context(inode, NULL); |
1d3576fd SW |
1015 | up_read(&mdsc->snap_rwsem); |
1016 | ||
80e755fe | 1017 | if (snapc->seq > oldest->seq) { |
6298a337 | 1018 | ceph_put_snap_context(oldest); |
1d3576fd | 1019 | dout(" page %p snapc %p not current or oldest\n", |
6298a337 | 1020 | page, snapc); |
1d3576fd SW |
1021 | /* |
1022 | * queue for writeback, and wait for snapc to | |
1023 | * be writeable or written | |
1024 | */ | |
6298a337 | 1025 | snapc = ceph_get_snap_context(snapc); |
1d3576fd | 1026 | unlock_page(page); |
3c6f6b79 | 1027 | ceph_queue_writeback(inode); |
8f883c24 | 1028 | r = wait_event_interruptible(ci->i_cap_wq, |
1d3576fd SW |
1029 | context_is_writeable_or_written(inode, snapc)); |
1030 | ceph_put_snap_context(snapc); | |
8f883c24 SW |
1031 | if (r == -ERESTARTSYS) |
1032 | return r; | |
4af6b225 | 1033 | return -EAGAIN; |
1d3576fd | 1034 | } |
6298a337 | 1035 | ceph_put_snap_context(oldest); |
1d3576fd SW |
1036 | |
1037 | /* yay, writeable, do it now (without dropping page lock) */ | |
1038 | dout(" page %p snapc %p not current, but oldest\n", | |
1039 | page, snapc); | |
1040 | if (!clear_page_dirty_for_io(page)) | |
1041 | goto retry_locked; | |
1042 | r = writepage_nounlock(page, NULL); | |
1043 | if (r < 0) | |
1044 | goto fail_nosnap; | |
1045 | goto retry_locked; | |
1046 | } | |
1047 | ||
1048 | if (PageUptodate(page)) { | |
1049 | dout(" page %p already uptodate\n", page); | |
1050 | return 0; | |
1051 | } | |
1052 | ||
1053 | /* full page? */ | |
1054 | if (pos_in_page == 0 && len == PAGE_CACHE_SIZE) | |
1055 | return 0; | |
1056 | ||
1057 | /* past end of file? */ | |
1058 | i_size = inode->i_size; /* caller holds i_mutex */ | |
1059 | ||
1060 | if (i_size + len > inode->i_sb->s_maxbytes) { | |
1061 | /* file is too big */ | |
1062 | r = -EINVAL; | |
1063 | goto fail; | |
1064 | } | |
1065 | ||
1066 | if (page_off >= i_size || | |
1067 | (pos_in_page == 0 && (pos+len) >= i_size && | |
1068 | end_in_page - pos_in_page != PAGE_CACHE_SIZE)) { | |
1069 | dout(" zeroing %p 0 - %d and %d - %d\n", | |
1070 | page, pos_in_page, end_in_page, (int)PAGE_CACHE_SIZE); | |
1071 | zero_user_segments(page, | |
1072 | 0, pos_in_page, | |
1073 | end_in_page, PAGE_CACHE_SIZE); | |
1074 | return 0; | |
1075 | } | |
1076 | ||
1077 | /* we need to read it. */ | |
1078 | up_read(&mdsc->snap_rwsem); | |
1079 | r = readpage_nounlock(file, page); | |
1080 | if (r < 0) | |
1081 | goto fail_nosnap; | |
1082 | goto retry_locked; | |
1083 | ||
1084 | fail: | |
1085 | up_read(&mdsc->snap_rwsem); | |
1086 | fail_nosnap: | |
1087 | unlock_page(page); | |
1088 | return r; | |
1089 | } | |
1090 | ||
4af6b225 YS |
1091 | /* |
1092 | * We are only allowed to write into/dirty the page if the page is | |
1093 | * clean, or already dirty within the same snap context. | |
1094 | */ | |
1095 | static int ceph_write_begin(struct file *file, struct address_space *mapping, | |
1096 | loff_t pos, unsigned len, unsigned flags, | |
1097 | struct page **pagep, void **fsdata) | |
1098 | { | |
496ad9aa | 1099 | struct inode *inode = file_inode(file); |
4af6b225 YS |
1100 | struct page *page; |
1101 | pgoff_t index = pos >> PAGE_CACHE_SHIFT; | |
7971bd92 | 1102 | int r; |
4af6b225 YS |
1103 | |
1104 | do { | |
8f883c24 | 1105 | /* get a page */ |
4af6b225 | 1106 | page = grab_cache_page_write_begin(mapping, index, 0); |
7971bd92 SW |
1107 | if (!page) |
1108 | return -ENOMEM; | |
1109 | *pagep = page; | |
4af6b225 YS |
1110 | |
1111 | dout("write_begin file %p inode %p page %p %d~%d\n", file, | |
213c99ee | 1112 | inode, page, (int)pos, (int)len); |
4af6b225 YS |
1113 | |
1114 | r = ceph_update_writeable_page(file, pos, len, page); | |
1115 | } while (r == -EAGAIN); | |
1116 | ||
1117 | return r; | |
1118 | } | |
1119 | ||
1d3576fd SW |
1120 | /* |
1121 | * we don't do anything in here that simple_write_end doesn't do | |
1122 | * except adjust dirty page accounting and drop read lock on | |
1123 | * mdsc->snap_rwsem. | |
1124 | */ | |
1125 | static int ceph_write_end(struct file *file, struct address_space *mapping, | |
1126 | loff_t pos, unsigned len, unsigned copied, | |
1127 | struct page *page, void *fsdata) | |
1128 | { | |
496ad9aa | 1129 | struct inode *inode = file_inode(file); |
3d14c5d2 YS |
1130 | struct ceph_fs_client *fsc = ceph_inode_to_client(inode); |
1131 | struct ceph_mds_client *mdsc = fsc->mdsc; | |
1d3576fd SW |
1132 | unsigned from = pos & (PAGE_CACHE_SIZE - 1); |
1133 | int check_cap = 0; | |
1134 | ||
1135 | dout("write_end file %p inode %p page %p %d~%d (%d)\n", file, | |
1136 | inode, page, (int)pos, (int)copied, (int)len); | |
1137 | ||
1138 | /* zero the stale part of the page if we did a short copy */ | |
1139 | if (copied < len) | |
1140 | zero_user_segment(page, from+copied, len); | |
1141 | ||
1142 | /* did file size increase? */ | |
1143 | /* (no need for i_size_read(); we caller holds i_mutex */ | |
1144 | if (pos+copied > inode->i_size) | |
1145 | check_cap = ceph_inode_set_size(inode, pos+copied); | |
1146 | ||
1147 | if (!PageUptodate(page)) | |
1148 | SetPageUptodate(page); | |
1149 | ||
1150 | set_page_dirty(page); | |
1151 | ||
1152 | unlock_page(page); | |
1153 | up_read(&mdsc->snap_rwsem); | |
1154 | page_cache_release(page); | |
1155 | ||
1156 | if (check_cap) | |
1157 | ceph_check_caps(ceph_inode(inode), CHECK_CAPS_AUTHONLY, NULL); | |
1158 | ||
1159 | return copied; | |
1160 | } | |
1161 | ||
1162 | /* | |
1163 | * we set .direct_IO to indicate direct io is supported, but since we | |
1164 | * intercept O_DIRECT reads and writes early, this function should | |
1165 | * never get called. | |
1166 | */ | |
1167 | static ssize_t ceph_direct_io(int rw, struct kiocb *iocb, | |
1168 | const struct iovec *iov, | |
1169 | loff_t pos, unsigned long nr_segs) | |
1170 | { | |
1171 | WARN_ON(1); | |
1172 | return -EINVAL; | |
1173 | } | |
1174 | ||
1175 | const struct address_space_operations ceph_aops = { | |
1176 | .readpage = ceph_readpage, | |
1177 | .readpages = ceph_readpages, | |
1178 | .writepage = ceph_writepage, | |
1179 | .writepages = ceph_writepages_start, | |
1180 | .write_begin = ceph_write_begin, | |
1181 | .write_end = ceph_write_end, | |
1182 | .set_page_dirty = ceph_set_page_dirty, | |
1183 | .invalidatepage = ceph_invalidatepage, | |
1184 | .releasepage = ceph_releasepage, | |
1185 | .direct_IO = ceph_direct_io, | |
1186 | }; | |
1187 | ||
1188 | ||
1189 | /* | |
1190 | * vm ops | |
1191 | */ | |
1192 | ||
1193 | /* | |
1194 | * Reuse write_begin here for simplicity. | |
1195 | */ | |
1196 | static int ceph_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) | |
1197 | { | |
496ad9aa | 1198 | struct inode *inode = file_inode(vma->vm_file); |
1d3576fd | 1199 | struct page *page = vmf->page; |
3d14c5d2 | 1200 | struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc; |
6285bc23 | 1201 | loff_t off = page_offset(page); |
1d3576fd | 1202 | loff_t size, len; |
1d3576fd SW |
1203 | int ret; |
1204 | ||
3ca9c3bd JK |
1205 | /* Update time before taking page lock */ |
1206 | file_update_time(vma->vm_file); | |
1207 | ||
1d3576fd SW |
1208 | size = i_size_read(inode); |
1209 | if (off + PAGE_CACHE_SIZE <= size) | |
1210 | len = PAGE_CACHE_SIZE; | |
1211 | else | |
1212 | len = size & ~PAGE_CACHE_MASK; | |
1213 | ||
1214 | dout("page_mkwrite %p %llu~%llu page %p idx %lu\n", inode, | |
1215 | off, len, page, page->index); | |
4af6b225 YS |
1216 | |
1217 | lock_page(page); | |
1218 | ||
1219 | ret = VM_FAULT_NOPAGE; | |
1220 | if ((off > size) || | |
1221 | (page->mapping != inode->i_mapping)) | |
1222 | goto out; | |
1223 | ||
1224 | ret = ceph_update_writeable_page(vma->vm_file, off, len, page); | |
1225 | if (ret == 0) { | |
1226 | /* success. we'll keep the page locked. */ | |
1d3576fd SW |
1227 | set_page_dirty(page); |
1228 | up_read(&mdsc->snap_rwsem); | |
1d3576fd SW |
1229 | ret = VM_FAULT_LOCKED; |
1230 | } else { | |
4af6b225 YS |
1231 | if (ret == -ENOMEM) |
1232 | ret = VM_FAULT_OOM; | |
1233 | else | |
1234 | ret = VM_FAULT_SIGBUS; | |
1d3576fd | 1235 | } |
4af6b225 | 1236 | out: |
1d3576fd | 1237 | dout("page_mkwrite %p %llu~%llu = %d\n", inode, off, len, ret); |
4af6b225 YS |
1238 | if (ret != VM_FAULT_LOCKED) |
1239 | unlock_page(page); | |
1d3576fd SW |
1240 | return ret; |
1241 | } | |
1242 | ||
1243 | static struct vm_operations_struct ceph_vmops = { | |
1244 | .fault = filemap_fault, | |
1245 | .page_mkwrite = ceph_page_mkwrite, | |
0b173bc4 | 1246 | .remap_pages = generic_file_remap_pages, |
1d3576fd SW |
1247 | }; |
1248 | ||
1249 | int ceph_mmap(struct file *file, struct vm_area_struct *vma) | |
1250 | { | |
1251 | struct address_space *mapping = file->f_mapping; | |
1252 | ||
1253 | if (!mapping->a_ops->readpage) | |
1254 | return -ENOEXEC; | |
1255 | file_accessed(file); | |
1256 | vma->vm_ops = &ceph_vmops; | |
1d3576fd SW |
1257 | return 0; |
1258 | } |