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Yehuda Sadeh3d14c5d2010-04-06 15:14:15 -07001#include <linux/ceph/ceph_debug.h>
Sage Weil1d3576f2009-10-06 11:31:09 -07002
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 */
Tejun Heo5a0e3ad2010-03-24 17:04:11 +09008#include <linux/slab.h>
Sage Weil1d3576f2009-10-06 11:31:09 -07009#include <linux/pagevec.h>
10#include <linux/task_io_accounting_ops.h>
11
12#include "super.h"
Yehuda Sadeh3d14c5d2010-04-06 15:14:15 -070013#include "mds_client.h"
14#include <linux/ceph/osd_client.h>
Sage Weil1d3576f2009-10-06 11:31:09 -070015
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
Lucas De Marchi25985ed2011-03-30 22:57:33 -030027 * count dirty pages on the inode. In the absence of snapshots,
Sage Weil1d3576f2009-10-06 11:31:09 -070028 * 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
Yehuda Sadeh2baba252009-12-18 13:51:57 -080052#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
Yan, Zheng61600ef2012-05-28 14:44:30 +080057static 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}
Sage Weil1d3576f2009-10-06 11:31:09 -070063
64/*
65 * Dirty a page. Optimistically adjust accounting, on the assumption
66 * that we won't race with invalidate. If we do, readjust.
67 */
68static 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 */
Sage Weilbe655592011-11-30 09:47:09 -080095 spin_lock(&ci->i_ceph_lock);
Sage Weil7d8cb262010-08-24 08:44:16 -070096 if (ci->i_head_snapc == NULL)
Sage Weil1d3576f2009-10-06 11:31:09 -070097 ci->i_head_snapc = ceph_get_snap_context(snapc);
98 ++ci->i_wrbuffer_ref_head;
99 if (ci->i_wrbuffer_ref == 0)
Dave Chinner0444d762011-03-29 18:08:50 +1100100 ihold(inode);
Sage Weil1d3576f2009-10-06 11:31:09 -0700101 ++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);
Sage Weilbe655592011-11-30 09:47:09 -0800108 spin_unlock(&ci->i_ceph_lock);
Sage Weil1d3576f2009-10-06 11:31:09 -0700109
110 /* now adjust page */
111 spin_lock_irq(&mapping->tree_lock);
112 if (page->mapping) { /* Race with truncate? */
113 WARN_ON_ONCE(!PageUptodate(page));
Michael Rubin679ceac2010-08-20 02:31:26 -0700114 account_page_dirtied(page, page->mapping);
Sage Weil1d3576f2009-10-06 11:31:09 -0700115 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 */
Lukas Czernerd47992f2013-05-21 23:17:23 -0400146static void ceph_invalidatepage(struct page *page, unsigned int offset,
147 unsigned int length)
Sage Weil1d3576f2009-10-06 11:31:09 -0700148{
Alexander Beregalov4ce1e9a2010-02-22 17:17:44 +0300149 struct inode *inode;
Sage Weil1d3576f2009-10-06 11:31:09 -0700150 struct ceph_inode_info *ci;
Yan, Zheng61600ef2012-05-28 14:44:30 +0800151 struct ceph_snap_context *snapc = page_snap_context(page);
Sage Weil1d3576f2009-10-06 11:31:09 -0700152
153 BUG_ON(!PageLocked(page));
Sage Weil1d3576f2009-10-06 11:31:09 -0700154 BUG_ON(!PagePrivate(page));
155 BUG_ON(!page->mapping);
156
Alexander Beregalov4ce1e9a2010-02-22 17:17:44 +0300157 inode = page->mapping->host;
158
Sage Weil1d3576f2009-10-06 11:31:09 -0700159 /*
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
Lukas Czerner569d39f2013-05-21 23:58:48 -0400167 if (offset == 0 && length == PAGE_CACHE_SIZE)
Sage Weil1d3576f2009-10-06 11:31:09 -0700168 ClearPageChecked(page);
169
170 ci = ceph_inode(inode);
Lukas Czerner569d39f2013-05-21 23:58:48 -0400171 if (offset == 0 && length == PAGE_CACHE_SIZE) {
172 dout("%p invalidatepage %p idx %lu full dirty page\n",
173 inode, page, page->index);
Sage Weil1d3576f2009-10-06 11:31:09 -0700174 ceph_put_wrbuffer_cap_refs(ci, 1, snapc);
175 ceph_put_snap_context(snapc);
176 page->private = 0;
177 ClearPagePrivate(page);
178 } else {
Lukas Czerner569d39f2013-05-21 23:58:48 -0400179 dout("%p invalidatepage %p idx %lu partial dirty page %u(%u)\n",
180 inode, page, page->index, offset, length);
Sage Weil1d3576f2009-10-06 11:31:09 -0700181 }
182}
183
184/* just a sanity check */
185static 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));
Sage Weil1d3576f2009-10-06 11:31:09 -0700190 WARN_ON(PagePrivate(page));
191 return 0;
192}
193
194/*
195 * read a single page, without unlocking it.
196 */
197static int readpage_nounlock(struct file *filp, struct page *page)
198{
Al Viro496ad9a2013-01-23 17:07:38 -0500199 struct inode *inode = file_inode(filp);
Sage Weil1d3576f2009-10-06 11:31:09 -0700200 struct ceph_inode_info *ci = ceph_inode(inode);
Yehuda Sadeh3d14c5d2010-04-06 15:14:15 -0700201 struct ceph_osd_client *osdc =
202 &ceph_inode_to_client(inode)->client->osdc;
Sage Weil1d3576f2009-10-06 11:31:09 -0700203 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,
Alex Elder6285bc22012-10-02 10:25:51 -0500209 (u64) page_offset(page), &len,
Sage Weil1d3576f2009-10-06 11:31:09 -0700210 ci->i_truncate_seq, ci->i_truncate_size,
Sage Weilb7495fc2010-11-09 12:43:12 -0800211 &page, 1, 0);
Sage Weil1d3576f2009-10-06 11:31:09 -0700212 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
223out:
224 return err < 0 ? err : 0;
225}
226
227static 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/*
Sage Weil7c272192011-08-03 09:58:09 -0700235 * Finish an async read(ahead) op.
Sage Weil1d3576f2009-10-06 11:31:09 -0700236 */
Sage Weil7c272192011-08-03 09:58:09 -0700237static void finish_read(struct ceph_osd_request *req, struct ceph_msg *msg)
Sage Weil1d3576f2009-10-06 11:31:09 -0700238{
Sage Weil7c272192011-08-03 09:58:09 -0700239 struct inode *inode = req->r_inode;
Alex Elder87060c12013-04-03 01:28:58 -0500240 struct ceph_osd_data *osd_data;
Sage Weil1b83bef2013-02-25 16:11:12 -0800241 int rc = req->r_result;
242 int bytes = le32_to_cpu(msg->hdr.data_len);
Alex Eldere0c59482013-03-07 15:38:25 -0600243 int num_pages;
Sage Weil7c272192011-08-03 09:58:09 -0700244 int i;
245
Sage Weil7c272192011-08-03 09:58:09 -0700246 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 */
Alex Elder406e2c92013-04-15 14:50:36 -0500249 osd_data = osd_req_op_extent_osd_data(req, 0);
Alex Elder87060c12013-04-03 01:28:58 -0500250 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);
Alex Eldere0c59482013-03-07 15:38:25 -0600253 for (i = 0; i < num_pages; i++) {
Alex Elder87060c12013-04-03 01:28:58 -0500254 struct page *page = osd_data->pages[i];
Sage Weil7c272192011-08-03 09:58:09 -0700255
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);
260 }
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);
Alex Elder0fff87e2013-02-14 12:16:43 -0600267 bytes -= PAGE_CACHE_SIZE;
Sage Weil7c272192011-08-03 09:58:09 -0700268 }
Alex Elder87060c12013-04-03 01:28:58 -0500269 kfree(osd_data->pages);
Sage Weil7c272192011-08-03 09:58:09 -0700270}
271
David Zafman8884d532012-12-03 19:14:05 -0800272static 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
Sage Weil7c272192011-08-03 09:58:09 -0700280/*
281 * start an async read(ahead) operation. return nr_pages we submitted
282 * a read for on success, or negative error code.
283 */
Sage Weil0d66a482011-08-04 08:21:30 -0700284static int start_read(struct inode *inode, struct list_head *page_list, int max)
Sage Weil7c272192011-08-03 09:58:09 -0700285{
286 struct ceph_osd_client *osdc =
287 &ceph_inode_to_client(inode)->client->osdc;
288 struct ceph_inode_info *ci = ceph_inode(inode);
289 struct page *page = list_entry(page_list->prev, struct page, lru);
Alex Elderacead002013-03-14 14:09:05 -0500290 struct ceph_vino vino;
Sage Weil7c272192011-08-03 09:58:09 -0700291 struct ceph_osd_request *req;
292 u64 off;
293 u64 len;
294 int i;
Sage Weil1d3576f2009-10-06 11:31:09 -0700295 struct page **pages;
Sage Weil7c272192011-08-03 09:58:09 -0700296 pgoff_t next_index;
297 int nr_pages = 0;
298 int ret;
299
Alex Elder6285bc22012-10-02 10:25:51 -0500300 off = (u64) page_offset(page);
Sage Weil7c272192011-08-03 09:58:09 -0700301
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++;
Sage Weil0d66a482011-08-04 08:21:30 -0700309 if (max && nr_pages == max)
310 break;
Sage Weil7c272192011-08-03 09:58:09 -0700311 }
312 len = nr_pages << PAGE_CACHE_SHIFT;
313 dout("start_read %p nr_pages %d is %lld~%lld\n", inode, nr_pages,
314 off, len);
Alex Elderacead002013-03-14 14:09:05 -0500315 vino = ceph_vino(inode);
316 req = ceph_osdc_new_request(osdc, &ci->i_layout, vino, off, &len,
Alex Elder79528732013-04-03 21:32:51 -0500317 1, CEPH_OSD_OP_READ,
Alex Elderacead002013-03-14 14:09:05 -0500318 CEPH_OSD_FLAG_READ, NULL,
Sage Weil7c272192011-08-03 09:58:09 -0700319 ci->i_truncate_seq, ci->i_truncate_size,
Alex Elderacead002013-03-14 14:09:05 -0500320 false);
Sage Weil68162822012-09-24 21:01:02 -0700321 if (IS_ERR(req))
322 return PTR_ERR(req);
Sage Weil1d3576f2009-10-06 11:31:09 -0700323
324 /* build page vector */
Alex Eldercf7b7e12013-03-01 18:00:15 -0600325 nr_pages = calc_pages_for(0, len);
Sage Weil7c272192011-08-03 09:58:09 -0700326 pages = kmalloc(sizeof(*pages) * nr_pages, GFP_NOFS);
327 ret = -ENOMEM;
Sage Weil1d3576f2009-10-06 11:31:09 -0700328 if (!pages)
Sage Weil7c272192011-08-03 09:58:09 -0700329 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));
333 list_del(&page->lru);
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,
338 GFP_NOFS)) {
339 page_cache_release(page);
340 dout("start_read %p add_to_page_cache failed %p\n",
341 inode, page);
342 nr_pages = i;
343 goto out_pages;
Sage Weil1d3576f2009-10-06 11:31:09 -0700344 }
Sage Weil7c272192011-08-03 09:58:09 -0700345 pages[i] = page;
Sage Weil1d3576f2009-10-06 11:31:09 -0700346 }
Alex Elder406e2c92013-04-15 14:50:36 -0500347 osd_req_op_extent_osd_data_pages(req, 0, pages, len, 0, false, false);
Sage Weil7c272192011-08-03 09:58:09 -0700348 req->r_callback = finish_read;
349 req->r_inode = inode;
350
Alex Elder79528732013-04-03 21:32:51 -0500351 ceph_osdc_build_request(req, off, NULL, vino.snap, NULL);
Alex Elder02ee07d2013-03-14 14:09:06 -0500352
Sage Weil7c272192011-08-03 09:58:09 -0700353 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
360out_pages:
David Zafman8884d532012-12-03 19:14:05 -0800361 ceph_unlock_page_vector(pages, nr_pages);
Sage Weil7c272192011-08-03 09:58:09 -0700362 ceph_release_page_vector(pages, nr_pages);
Sage Weil7c272192011-08-03 09:58:09 -0700363out:
364 ceph_osdc_put_request(req);
365 return ret;
Sage Weil1d3576f2009-10-06 11:31:09 -0700366}
367
Sage Weil7c272192011-08-03 09:58:09 -0700368
Sage Weil1d3576f2009-10-06 11:31:09 -0700369/*
370 * Read multiple pages. Leave pages we don't read + unlock in page_list;
371 * the caller (VM) cleans them up.
372 */
373static int ceph_readpages(struct file *file, struct address_space *mapping,
374 struct list_head *page_list, unsigned nr_pages)
375{
Al Viro496ad9a2013-01-23 17:07:38 -0500376 struct inode *inode = file_inode(file);
Sage Weil0d66a482011-08-04 08:21:30 -0700377 struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
Sage Weil1d3576f2009-10-06 11:31:09 -0700378 int rc = 0;
Sage Weil0d66a482011-08-04 08:21:30 -0700379 int max = 0;
Sage Weil1d3576f2009-10-06 11:31:09 -0700380
Sage Weil0d66a482011-08-04 08:21:30 -0700381 if (fsc->mount_options->rsize >= PAGE_CACHE_SIZE)
382 max = (fsc->mount_options->rsize + PAGE_CACHE_SIZE - 1)
383 >> PAGE_SHIFT;
384
Alex Elder2794a822013-02-14 12:16:43 -0600385 dout("readpages %p file %p nr_pages %d max %d\n", inode,
386 file, nr_pages,
Sage Weil0d66a482011-08-04 08:21:30 -0700387 max);
Sage Weil7c272192011-08-03 09:58:09 -0700388 while (!list_empty(page_list)) {
Sage Weil0d66a482011-08-04 08:21:30 -0700389 rc = start_read(inode, page_list, max);
Sage Weil7c272192011-08-03 09:58:09 -0700390 if (rc < 0)
391 goto out;
392 BUG_ON(rc == 0);
Sage Weil1d3576f2009-10-06 11:31:09 -0700393 }
Sage Weil1d3576f2009-10-06 11:31:09 -0700394out:
Sage Weil7c272192011-08-03 09:58:09 -0700395 dout("readpages %p file %p ret %d\n", inode, file, rc);
Sage Weil1d3576f2009-10-06 11:31:09 -0700396 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.
Sage Weil1d3576f2009-10-06 11:31:09 -0700402 */
Sage Weil6298a332010-03-31 22:01:38 -0700403static struct ceph_snap_context *get_oldest_context(struct inode *inode,
404 u64 *snap_size)
Sage Weil1d3576f2009-10-06 11:31:09 -0700405{
406 struct ceph_inode_info *ci = ceph_inode(inode);
407 struct ceph_snap_context *snapc = NULL;
408 struct ceph_cap_snap *capsnap = NULL;
409
Sage Weilbe655592011-11-30 09:47:09 -0800410 spin_lock(&ci->i_ceph_lock);
Sage Weil1d3576f2009-10-06 11:31:09 -0700411 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 }
Sage Weil7d8cb262010-08-24 08:44:16 -0700421 if (!snapc && ci->i_wrbuffer_ref_head) {
Sage Weil80e755f2010-03-31 21:52:10 -0700422 snapc = ceph_get_snap_context(ci->i_head_snapc);
Sage Weil1d3576f2009-10-06 11:31:09 -0700423 dout(" head snapc %p has %d dirty pages\n",
424 snapc, ci->i_wrbuffer_ref_head);
425 }
Sage Weilbe655592011-11-30 09:47:09 -0800426 spin_unlock(&ci->i_ceph_lock);
Sage Weil1d3576f2009-10-06 11:31:09 -0700427 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 */
436static int writepage_nounlock(struct page *page, struct writeback_control *wbc)
437{
438 struct inode *inode;
439 struct ceph_inode_info *ci;
Yehuda Sadeh3d14c5d2010-04-06 15:14:15 -0700440 struct ceph_fs_client *fsc;
Sage Weil1d3576f2009-10-06 11:31:09 -0700441 struct ceph_osd_client *osdc;
Sage Weil6298a332010-03-31 22:01:38 -0700442 struct ceph_snap_context *snapc, *oldest;
Yan, Zhengfc2744a2013-05-31 16:48:29 +0800443 loff_t page_off = page_offset(page);
Yehuda Sadeh2baba252009-12-18 13:51:57 -0800444 long writeback_stat;
Yan, Zhengfc2744a2013-05-31 16:48:29 +0800445 u64 truncate_size, snap_size = 0;
446 u32 truncate_seq;
447 int err = 0, len = PAGE_CACHE_SIZE;
Sage Weil1d3576f2009-10-06 11:31:09 -0700448
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);
Yehuda Sadeh3d14c5d2010-04-06 15:14:15 -0700457 fsc = ceph_inode_to_client(inode);
458 osdc = &fsc->client->osdc;
Sage Weil1d3576f2009-10-06 11:31:09 -0700459
460 /* verify this is a writeable snap context */
Yan, Zheng61600ef2012-05-28 14:44:30 +0800461 snapc = page_snap_context(page);
Sage Weil1d3576f2009-10-06 11:31:09 -0700462 if (snapc == NULL) {
463 dout("writepage %p page %p not dirty?\n", inode, page);
464 goto out;
465 }
Sage Weil6298a332010-03-31 22:01:38 -0700466 oldest = get_oldest_context(inode, &snap_size);
467 if (snapc->seq > oldest->seq) {
Sage Weil1d3576f2009-10-06 11:31:09 -0700468 dout("writepage %p page %p snapc %p not writeable - noop\n",
Yan, Zheng61600ef2012-05-28 14:44:30 +0800469 inode, page, snapc);
Sage Weil1d3576f2009-10-06 11:31:09 -0700470 /* we should only noop if called by kswapd */
471 WARN_ON((current->flags & PF_MEMALLOC) == 0);
Sage Weil6298a332010-03-31 22:01:38 -0700472 ceph_put_snap_context(oldest);
Sage Weil1d3576f2009-10-06 11:31:09 -0700473 goto out;
474 }
Sage Weil6298a332010-03-31 22:01:38 -0700475 ceph_put_snap_context(oldest);
Sage Weil1d3576f2009-10-06 11:31:09 -0700476
Yan, Zhengfc2744a2013-05-31 16:48:29 +0800477 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
Sage Weil1d3576f2009-10-06 11:31:09 -0700484 /* is this a partial page at end of file? */
Yan, Zhengfc2744a2013-05-31 16:48:29 +0800485 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;
Sage Weil1d3576f2009-10-06 11:31:09 -0700491
Sage Weilae00d4f2010-09-16 16:26:51 -0700492 dout("writepage %p page %p index %lu on %llu~%u snapc %p\n",
493 inode, page, page->index, page_off, len, snapc);
Sage Weil1d3576f2009-10-06 11:31:09 -0700494
Yehuda Sadeh3d14c5d2010-04-06 15:14:15 -0700495 writeback_stat = atomic_long_inc_return(&fsc->writeback_count);
Yehuda Sadeh2baba252009-12-18 13:51:57 -0800496 if (writeback_stat >
Yehuda Sadeh3d14c5d2010-04-06 15:14:15 -0700497 CONGESTION_ON_THRESH(fsc->mount_options->congestion_kb))
498 set_bdi_congested(&fsc->backing_dev_info, BLK_RW_ASYNC);
Yehuda Sadeh2baba252009-12-18 13:51:57 -0800499
Sage Weil1d3576f2009-10-06 11:31:09 -0700500 set_page_writeback(page);
501 err = ceph_osdc_writepages(osdc, ceph_vino(inode),
502 &ci->i_layout, snapc,
503 page_off, len,
Yan, Zhengfc2744a2013-05-31 16:48:29 +0800504 truncate_seq, truncate_size,
Alex Elder24808822013-02-15 11:42:29 -0600505 &inode->i_mtime, &page, 1);
Sage Weil1d3576f2009-10-06 11:31:09 -0700506 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);
Sage Weil6298a332010-03-31 22:01:38 -0700520 ceph_put_snap_context(snapc); /* page's reference */
Sage Weil1d3576f2009-10-06 11:31:09 -0700521out:
522 return err;
523}
524
525static int ceph_writepage(struct page *page, struct writeback_control *wbc)
526{
Yehuda Sadehdbd646a2009-12-16 14:51:06 -0800527 int err;
528 struct inode *inode = page->mapping->host;
529 BUG_ON(!inode);
Sage Weil70b666c2011-05-27 09:24:26 -0700530 ihold(inode);
Yehuda Sadehdbd646a2009-12-16 14:51:06 -0800531 err = writepage_nounlock(page, wbc);
Sage Weil1d3576f2009-10-06 11:31:09 -0700532 unlock_page(page);
Yehuda Sadehdbd646a2009-12-16 14:51:06 -0800533 iput(inode);
Sage Weil1d3576f2009-10-06 11:31:09 -0700534 return err;
535}
536
537
538/*
539 * lame release_pages helper. release_pages() isn't exported to
540 * modules.
541 */
542static 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 */
562static void writepages_finish(struct ceph_osd_request *req,
563 struct ceph_msg *msg)
564{
565 struct inode *inode = req->r_inode;
Sage Weil1d3576f2009-10-06 11:31:09 -0700566 struct ceph_inode_info *ci = ceph_inode(inode);
Alex Elder87060c12013-04-03 01:28:58 -0500567 struct ceph_osd_data *osd_data;
Sage Weil1d3576f2009-10-06 11:31:09 -0700568 unsigned wrote;
Sage Weil1d3576f2009-10-06 11:31:09 -0700569 struct page *page;
Alex Eldere0c59482013-03-07 15:38:25 -0600570 int num_pages;
Sage Weil1d3576f2009-10-06 11:31:09 -0700571 int i;
572 struct ceph_snap_context *snapc = req->r_snapc;
573 struct address_space *mapping = inode->i_mapping;
Sage Weil1b83bef2013-02-25 16:11:12 -0800574 int rc = req->r_result;
Alex Elder79528732013-04-03 21:32:51 -0500575 u64 bytes = req->r_ops[0].extent.length;
Yehuda Sadeh3d14c5d2010-04-06 15:14:15 -0700576 struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
Yehuda Sadeh2baba252009-12-18 13:51:57 -0800577 long writeback_stat;
Sage Weil7ff899d2010-04-23 10:25:33 -0700578 unsigned issued = ceph_caps_issued(ci);
Sage Weil1d3576f2009-10-06 11:31:09 -0700579
Alex Elder406e2c92013-04-15 14:50:36 -0500580 osd_data = osd_req_op_extent_osd_data(req, 0);
Alex Elder87060c12013-04-03 01:28:58 -0500581 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);
Sage Weil1d3576f2009-10-06 11:31:09 -0700584 if (rc >= 0) {
Sage Weil79788c62010-02-02 16:34:04 -0800585 /*
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 */
Alex Eldere0c59482013-03-07 15:38:25 -0600591 wrote = num_pages;
Sage Weil1d3576f2009-10-06 11:31:09 -0700592 } 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 */
Alex Eldere0c59482013-03-07 15:38:25 -0600600 for (i = 0; i < num_pages; i++) {
Alex Elder87060c12013-04-03 01:28:58 -0500601 page = osd_data->pages[i];
Sage Weil1d3576f2009-10-06 11:31:09 -0700602 BUG_ON(!page);
603 WARN_ON(!PageUptodate(page));
604
Yehuda Sadeh2baba252009-12-18 13:51:57 -0800605 writeback_stat =
Yehuda Sadeh3d14c5d2010-04-06 15:14:15 -0700606 atomic_long_dec_return(&fsc->writeback_count);
Yehuda Sadeh2baba252009-12-18 13:51:57 -0800607 if (writeback_stat <
Yehuda Sadeh3d14c5d2010-04-06 15:14:15 -0700608 CONGESTION_OFF_THRESH(fsc->mount_options->congestion_kb))
609 clear_bdi_congested(&fsc->backing_dev_info,
Yehuda Sadeh2baba252009-12-18 13:51:57 -0800610 BLK_RW_ASYNC);
611
Yan, Zheng61600ef2012-05-28 14:44:30 +0800612 ceph_put_snap_context(page_snap_context(page));
Sage Weil1d3576f2009-10-06 11:31:09 -0700613 page->private = 0;
614 ClearPagePrivate(page);
Sage Weil1d3576f2009-10-06 11:31:09 -0700615 dout("unlocking %d %p\n", i, page);
616 end_page_writeback(page);
Yehuda Sadehe63dc5c2010-02-19 00:07:01 +0000617
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 */
Sage Weil29625072010-05-27 10:40:43 -0700624 if ((issued & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) == 0)
Yehuda Sadehe63dc5c2010-02-19 00:07:01 +0000625 generic_error_remove_page(inode->i_mapping, page);
626
Sage Weil1d3576f2009-10-06 11:31:09 -0700627 unlock_page(page);
628 }
629 dout("%p wrote+cleaned %d pages\n", inode, wrote);
Alex Eldere0c59482013-03-07 15:38:25 -0600630 ceph_put_wrbuffer_cap_refs(ci, num_pages, snapc);
Sage Weil1d3576f2009-10-06 11:31:09 -0700631
Alex Elder87060c12013-04-03 01:28:58 -0500632 ceph_release_pages(osd_data->pages, num_pages);
633 if (osd_data->pages_from_pool)
634 mempool_free(osd_data->pages,
Cheng Renquan640ef792010-03-26 17:40:33 +0800635 ceph_sb_to_client(inode->i_sb)->wb_pagevec_pool);
Sage Weil1d3576f2009-10-06 11:31:09 -0700636 else
Alex Elder87060c12013-04-03 01:28:58 -0500637 kfree(osd_data->pages);
Sage Weil1d3576f2009-10-06 11:31:09 -0700638 ceph_osdc_put_request(req);
639}
640
Sage Weil1d3576f2009-10-06 11:31:09 -0700641/*
642 * initiate async writeback
643 */
644static int ceph_writepages_start(struct address_space *mapping,
645 struct writeback_control *wbc)
646{
647 struct inode *inode = mapping->host;
Sage Weil1d3576f2009-10-06 11:31:09 -0700648 struct ceph_inode_info *ci = ceph_inode(inode);
Yan, Zhengfc2744a2013-05-31 16:48:29 +0800649 struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
650 struct ceph_vino vino = ceph_vino(inode);
Sage Weil1d3576f2009-10-06 11:31:09 -0700651 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;
Sage Weil80e755f2010-03-31 21:52:10 -0700655 struct ceph_snap_context *snapc = NULL, *last_snapc = NULL, *pgsnapc;
Sage Weil1d3576f2009-10-06 11:31:09 -0700656 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;
Yan, Zhengfc2744a2013-05-31 16:48:29 +0800662 u64 truncate_size, snap_size;
663 u32 truncate_seq;
Sage Weil1d3576f2009-10-06 11:31:09 -0700664
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 */
majianpengc62988e2013-06-19 15:12:06 +0800670 if ((wbc->sync_mode == WB_SYNC_ALL) ||
671 ceph_caps_revoking(ci, CEPH_CAP_FILE_BUFFER))
Sage Weil1d3576f2009-10-06 11:31:09 -0700672 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
Yehuda Sadeh3d14c5d2010-04-06 15:14:15 -0700678 if (fsc->mount_state == CEPH_MOUNT_SHUTDOWN) {
Sage Weil1d3576f2009-10-06 11:31:09 -0700679 pr_warning("writepage_start %p on forced umount\n", inode);
680 return -EIO; /* we're in a forced umount, don't write! */
681 }
Yehuda Sadeh3d14c5d2010-04-06 15:14:15 -0700682 if (fsc->mount_options->wsize && fsc->mount_options->wsize < wsize)
683 wsize = fsc->mount_options->wsize;
Sage Weil1d3576f2009-10-06 11:31:09 -0700684 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
Sage Weil1d3576f2009-10-06 11:31:09 -0700690 /* 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
705retry:
706 /* find oldest snap context with dirty data */
707 ceph_put_snap_context(snapc);
Yan, Zheng1ac0fc82013-04-12 21:45:42 +0800708 snap_size = 0;
Sage Weil1d3576f2009-10-06 11:31:09 -0700709 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 }
Yan, Zheng1ac0fc82013-04-12 21:45:42 +0800716 if (snap_size == 0)
717 snap_size = i_size_read(inode);
Sage Weil1d3576f2009-10-06 11:31:09 -0700718 dout(" oldest snapc is %p seq %lld (%d snaps)\n",
719 snapc, snapc->seq, snapc->num_snaps);
Yan, Zhengfc2744a2013-05-31 16:48:29 +0800720
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
Sage Weil1d3576f2009-10-06 11:31:09 -0700728 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) {
Alex Eldere5975c72013-03-14 14:09:05 -0500738 int num_ops = do_sync ? 2 : 1;
Sage Weil1d3576f2009-10-06 11:31:09 -0700739 unsigned i;
740 int first;
741 pgoff_t next;
742 int pvec_pages, locked_pages;
Alex Eldere5975c72013-03-14 14:09:05 -0500743 struct page **pages = NULL;
744 mempool_t *pool = NULL; /* Becomes non-null if mempool used */
Sage Weil1d3576f2009-10-06 11:31:09 -0700745 struct page *page;
746 int want;
747 u64 offset, len;
Yehuda Sadeh2baba252009-12-18 13:51:57 -0800748 long writeback_stat;
Sage Weil1d3576f2009-10-06 11:31:09 -0700749
750 next = 0;
751 locked_pages = 0;
752 max_pages = max_pages_ever;
753
754get_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 }
Yan, Zheng1ac0fc82013-04-12 21:45:42 +0800796 if (page_offset(page) >= snap_size) {
797 dout("%p page eof %llu\n", page, snap_size);
Sage Weil1d3576f2009-10-06 11:31:09 -0700798 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 */
Yan, Zheng61600ef2012-05-28 14:44:30 +0800809 pgsnapc = page_snap_context(page);
Sage Weil80e755f2010-03-31 21:52:10 -0700810 if (pgsnapc->seq > snapc->seq) {
811 dout("page snapc %p %lld > oldest %p %lld\n",
812 pgsnapc, pgsnapc->seq, snapc, snapc->seq);
Sage Weil1d3576f2009-10-06 11:31:09 -0700813 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
Alex Eldere5975c72013-03-14 14:09:05 -0500825 /*
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 */
Sage Weil1d3576f2009-10-06 11:31:09 -0700831 if (locked_pages == 0) {
Alex Eldere5975c72013-03-14 14:09:05 -0500832 BUG_ON(pages);
Sage Weil1d3576f2009-10-06 11:31:09 -0700833 /* prepare async write request */
Alex Eldere5975c72013-03-14 14:09:05 -0500834 offset = (u64)page_offset(page);
Sage Weil1d3576f2009-10-06 11:31:09 -0700835 len = wsize;
Yan, Zhengfc2744a2013-05-31 16:48:29 +0800836 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);
Sage Weil68162822012-09-24 21:01:02 -0700844 if (IS_ERR(req)) {
845 rc = PTR_ERR(req);
Henry C Chang8c718972011-05-03 09:45:16 +0000846 unlock_page(page);
847 break;
848 }
849
Alex Elder88486952013-03-14 14:09:05 -0500850 req->r_callback = writepages_finish;
851 req->r_inode = inode;
852
853 max_pages = calc_pages_for(0, (u64)len);
Yan, Zhengfc2744a2013-05-31 16:48:29 +0800854 pages = kmalloc(max_pages * sizeof (*pages),
855 GFP_NOFS);
Alex Elder88486952013-03-14 14:09:05 -0500856 if (!pages) {
857 pool = fsc->wb_pagevec_pool;
Alex Elder88486952013-03-14 14:09:05 -0500858 pages = mempool_alloc(pool, GFP_NOFS);
Alex Eldere5975c72013-03-14 14:09:05 -0500859 BUG_ON(!pages);
Alex Elder88486952013-03-14 14:09:05 -0500860 }
Sage Weil1d3576f2009-10-06 11:31:09 -0700861 }
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);
Yehuda Sadeh2baba252009-12-18 13:51:57 -0800868
Sage Weil213c99e2010-08-03 10:25:11 -0700869 writeback_stat =
Yehuda Sadeh3d14c5d2010-04-06 15:14:15 -0700870 atomic_long_inc_return(&fsc->writeback_count);
Sage Weil213c99e2010-08-03 10:25:11 -0700871 if (writeback_stat > CONGESTION_ON_THRESH(
Yehuda Sadeh3d14c5d2010-04-06 15:14:15 -0700872 fsc->mount_options->congestion_kb)) {
873 set_bdi_congested(&fsc->backing_dev_info,
Sage Weil213c99e2010-08-03 10:25:11 -0700874 BLK_RW_ASYNC);
Yehuda Sadeh2baba252009-12-18 13:51:57 -0800875 }
876
Sage Weil1d3576f2009-10-06 11:31:09 -0700877 set_page_writeback(page);
Alex Eldere5975c72013-03-14 14:09:05 -0500878 pages[locked_pages] = page;
Sage Weil1d3576f2009-10-06 11:31:09 -0700879 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
Alex Eldere5975c72013-03-14 14:09:05 -0500907 /* Format the osd request message and submit the write */
908
909 offset = page_offset(pages[0]);
Yan, Zheng1ac0fc82013-04-12 21:45:42 +0800910 len = min(snap_size - offset,
Sage Weil1d3576f2009-10-06 11:31:09 -0700911 (u64)locked_pages << PAGE_CACHE_SHIFT);
912 dout("writepages got %d pages at %llu~%llu\n",
913 locked_pages, offset, len);
914
Alex Elder406e2c92013-04-15 14:50:36 -0500915 osd_req_op_extent_osd_data_pages(req, 0, pages, len, 0,
Alex Eldera4ce40a2013-04-05 01:27:12 -0500916 !!pool, false);
Alex Eldere5975c72013-03-14 14:09:05 -0500917
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
Alex Elderc99d2d42013-04-05 01:27:11 -0500923 osd_req_op_extent_update(req, 0, len);
Alex Eldere5975c72013-03-14 14:09:05 -0500924
925 vino = ceph_vino(inode);
Alex Elder79528732013-04-03 21:32:51 -0500926 ceph_osdc_build_request(req, offset, snapc, vino.snap,
927 &inode->i_mtime);
Sage Weil1d3576f2009-10-06 11:31:09 -0700928
Sage Weil9d6fcb02011-05-12 15:48:16 -0700929 rc = ceph_osdc_start_request(&fsc->client->osdc, req, true);
930 BUG_ON(rc);
Sage Weil1d3576f2009-10-06 11:31:09 -0700931 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
939release_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
959out:
960 if (req)
961 ceph_osdc_put_request(req);
Sage Weil1d3576f2009-10-06 11:31:09 -0700962 ceph_put_snap_context(snapc);
963 dout("writepages done, rc = %d\n", rc);
Sage Weil1d3576f2009-10-06 11:31:09 -0700964 return rc;
965}
966
967
968
969/*
970 * See if a given @snapc is either writeable, or already written.
971 */
972static 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);
Sage Weil6298a332010-03-31 22:01:38 -0700976 int ret = !oldest || snapc->seq <= oldest->seq;
977
978 ceph_put_snap_context(oldest);
979 return ret;
Sage Weil1d3576f2009-10-06 11:31:09 -0700980}
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.
Sage Weil8f883c22010-03-19 13:27:53 -0700985 *
986 * called with page locked.
987 * return success with page locked,
988 * or any failure (incl -EAGAIN) with page unlocked.
Sage Weil1d3576f2009-10-06 11:31:09 -0700989 */
Yehuda Sadeh4af6b222010-02-09 11:02:51 -0800990static int ceph_update_writeable_page(struct file *file,
991 loff_t pos, unsigned len,
992 struct page *page)
Sage Weil1d3576f2009-10-06 11:31:09 -0700993{
Al Viro496ad9a2013-01-23 17:07:38 -0500994 struct inode *inode = file_inode(file);
Sage Weil1d3576f2009-10-06 11:31:09 -0700995 struct ceph_inode_info *ci = ceph_inode(inode);
Yehuda Sadeh3d14c5d2010-04-06 15:14:15 -0700996 struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc;
Sage Weil1d3576f2009-10-06 11:31:09 -0700997 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;
Sage Weil1d3576f2009-10-06 11:31:09 -07001001 int r;
Sage Weil80e755f2010-03-31 21:52:10 -07001002 struct ceph_snap_context *snapc, *oldest;
Sage Weil1d3576f2009-10-06 11:31:09 -07001003
Sage Weil1d3576f2009-10-06 11:31:09 -07001004retry_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);
Yan, Zheng61600ef2012-05-28 14:44:30 +08001012 snapc = page_snap_context(page);
Sage Weil80e755f2010-03-31 21:52:10 -07001013 if (snapc && snapc != ci->i_head_snapc) {
Sage Weil1d3576f2009-10-06 11:31:09 -07001014 /*
1015 * this page is already dirty in another (older) snap
1016 * context! is it writeable now?
1017 */
Sage Weil80e755f2010-03-31 21:52:10 -07001018 oldest = get_oldest_context(inode, NULL);
Sage Weil1d3576f2009-10-06 11:31:09 -07001019 up_read(&mdsc->snap_rwsem);
1020
Sage Weil80e755f2010-03-31 21:52:10 -07001021 if (snapc->seq > oldest->seq) {
Sage Weil6298a332010-03-31 22:01:38 -07001022 ceph_put_snap_context(oldest);
Sage Weil1d3576f2009-10-06 11:31:09 -07001023 dout(" page %p snapc %p not current or oldest\n",
Sage Weil6298a332010-03-31 22:01:38 -07001024 page, snapc);
Sage Weil1d3576f2009-10-06 11:31:09 -07001025 /*
1026 * queue for writeback, and wait for snapc to
1027 * be writeable or written
1028 */
Sage Weil6298a332010-03-31 22:01:38 -07001029 snapc = ceph_get_snap_context(snapc);
Sage Weil1d3576f2009-10-06 11:31:09 -07001030 unlock_page(page);
Sage Weil3c6f6b72010-02-09 15:24:44 -08001031 ceph_queue_writeback(inode);
Sage Weil8f883c22010-03-19 13:27:53 -07001032 r = wait_event_interruptible(ci->i_cap_wq,
Sage Weil1d3576f2009-10-06 11:31:09 -07001033 context_is_writeable_or_written(inode, snapc));
1034 ceph_put_snap_context(snapc);
Sage Weil8f883c22010-03-19 13:27:53 -07001035 if (r == -ERESTARTSYS)
1036 return r;
Yehuda Sadeh4af6b222010-02-09 11:02:51 -08001037 return -EAGAIN;
Sage Weil1d3576f2009-10-06 11:31:09 -07001038 }
Sage Weil6298a332010-03-31 22:01:38 -07001039 ceph_put_snap_context(oldest);
Sage Weil1d3576f2009-10-06 11:31:09 -07001040
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
1088fail:
1089 up_read(&mdsc->snap_rwsem);
1090fail_nosnap:
1091 unlock_page(page);
1092 return r;
1093}
1094
1095/*
Yehuda Sadeh4af6b222010-02-09 11:02:51 -08001096 * 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 */
1099static 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{
Al Viro496ad9a2013-01-23 17:07:38 -05001103 struct inode *inode = file_inode(file);
Yehuda Sadeh4af6b222010-02-09 11:02:51 -08001104 struct page *page;
1105 pgoff_t index = pos >> PAGE_CACHE_SHIFT;
Sage Weil7971bd92013-05-01 21:15:58 -07001106 int r;
Yehuda Sadeh4af6b222010-02-09 11:02:51 -08001107
1108 do {
Sage Weil8f883c22010-03-19 13:27:53 -07001109 /* get a page */
Yehuda Sadeh4af6b222010-02-09 11:02:51 -08001110 page = grab_cache_page_write_begin(mapping, index, 0);
Sage Weil7971bd92013-05-01 21:15:58 -07001111 if (!page)
1112 return -ENOMEM;
1113 *pagep = page;
Yehuda Sadeh4af6b222010-02-09 11:02:51 -08001114
1115 dout("write_begin file %p inode %p page %p %d~%d\n", file,
Sage Weil213c99e2010-08-03 10:25:11 -07001116 inode, page, (int)pos, (int)len);
Yehuda Sadeh4af6b222010-02-09 11:02:51 -08001117
1118 r = ceph_update_writeable_page(file, pos, len, page);
1119 } while (r == -EAGAIN);
1120
1121 return r;
1122}
1123
1124/*
Sage Weil1d3576f2009-10-06 11:31:09 -07001125 * 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 */
1129static 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{
Al Viro496ad9a2013-01-23 17:07:38 -05001133 struct inode *inode = file_inode(file);
Yehuda Sadeh3d14c5d2010-04-06 15:14:15 -07001134 struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
1135 struct ceph_mds_client *mdsc = fsc->mdsc;
Sage Weil1d3576f2009-10-06 11:31:09 -07001136 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 */
1171static 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
1179const 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 */
1200static int ceph_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
1201{
Al Viro496ad9a2013-01-23 17:07:38 -05001202 struct inode *inode = file_inode(vma->vm_file);
Sage Weil1d3576f2009-10-06 11:31:09 -07001203 struct page *page = vmf->page;
Yehuda Sadeh3d14c5d2010-04-06 15:14:15 -07001204 struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc;
Alex Elder6285bc22012-10-02 10:25:51 -05001205 loff_t off = page_offset(page);
Sage Weil1d3576f2009-10-06 11:31:09 -07001206 loff_t size, len;
Sage Weil1d3576f2009-10-06 11:31:09 -07001207 int ret;
1208
Jan Kara3ca9c3b2012-06-12 16:20:24 +02001209 /* Update time before taking page lock */
1210 file_update_time(vma->vm_file);
1211
Sage Weil1d3576f2009-10-06 11:31:09 -07001212 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);
Yehuda Sadeh4af6b222010-02-09 11:02:51 -08001220
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. */
Sage Weil1d3576f2009-10-06 11:31:09 -07001231 set_page_dirty(page);
1232 up_read(&mdsc->snap_rwsem);
Sage Weil1d3576f2009-10-06 11:31:09 -07001233 ret = VM_FAULT_LOCKED;
1234 } else {
Yehuda Sadeh4af6b222010-02-09 11:02:51 -08001235 if (ret == -ENOMEM)
1236 ret = VM_FAULT_OOM;
1237 else
1238 ret = VM_FAULT_SIGBUS;
Sage Weil1d3576f2009-10-06 11:31:09 -07001239 }
Yehuda Sadeh4af6b222010-02-09 11:02:51 -08001240out:
Sage Weil1d3576f2009-10-06 11:31:09 -07001241 dout("page_mkwrite %p %llu~%llu = %d\n", inode, off, len, ret);
Yehuda Sadeh4af6b222010-02-09 11:02:51 -08001242 if (ret != VM_FAULT_LOCKED)
1243 unlock_page(page);
Sage Weil1d3576f2009-10-06 11:31:09 -07001244 return ret;
1245}
1246
1247static struct vm_operations_struct ceph_vmops = {
1248 .fault = filemap_fault,
1249 .page_mkwrite = ceph_page_mkwrite,
Konstantin Khlebnikov0b173bc2012-10-08 16:28:46 -07001250 .remap_pages = generic_file_remap_pages,
Sage Weil1d3576f2009-10-06 11:31:09 -07001251};
1252
1253int 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;
Sage Weil1d3576f2009-10-06 11:31:09 -07001261 return 0;
1262}