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Commit | Line | Data |
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0a8165d7 | 1 | /* |
eb47b800 JK |
2 | * fs/f2fs/data.c |
3 | * | |
4 | * Copyright (c) 2012 Samsung Electronics Co., Ltd. | |
5 | * http://www.samsung.com/ | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | */ | |
11 | #include <linux/fs.h> | |
12 | #include <linux/f2fs_fs.h> | |
13 | #include <linux/buffer_head.h> | |
14 | #include <linux/mpage.h> | |
15 | #include <linux/writeback.h> | |
16 | #include <linux/backing-dev.h> | |
17 | #include <linux/blkdev.h> | |
18 | #include <linux/bio.h> | |
19 | ||
20 | #include "f2fs.h" | |
21 | #include "node.h" | |
22 | #include "segment.h" | |
23 | ||
0a8165d7 | 24 | /* |
eb47b800 JK |
25 | * Lock ordering for the change of data block address: |
26 | * ->data_page | |
27 | * ->node_page | |
28 | * update block addresses in the node page | |
29 | */ | |
30 | static void __set_data_blkaddr(struct dnode_of_data *dn, block_t new_addr) | |
31 | { | |
32 | struct f2fs_node *rn; | |
33 | __le32 *addr_array; | |
34 | struct page *node_page = dn->node_page; | |
35 | unsigned int ofs_in_node = dn->ofs_in_node; | |
36 | ||
37 | wait_on_page_writeback(node_page); | |
38 | ||
39 | rn = (struct f2fs_node *)page_address(node_page); | |
40 | ||
41 | /* Get physical address of data block */ | |
42 | addr_array = blkaddr_in_node(rn); | |
43 | addr_array[ofs_in_node] = cpu_to_le32(new_addr); | |
44 | set_page_dirty(node_page); | |
45 | } | |
46 | ||
47 | int reserve_new_block(struct dnode_of_data *dn) | |
48 | { | |
49 | struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb); | |
50 | ||
51 | if (is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC)) | |
52 | return -EPERM; | |
53 | if (!inc_valid_block_count(sbi, dn->inode, 1)) | |
54 | return -ENOSPC; | |
55 | ||
56 | __set_data_blkaddr(dn, NEW_ADDR); | |
57 | dn->data_blkaddr = NEW_ADDR; | |
58 | sync_inode_page(dn); | |
59 | return 0; | |
60 | } | |
61 | ||
62 | static int check_extent_cache(struct inode *inode, pgoff_t pgofs, | |
63 | struct buffer_head *bh_result) | |
64 | { | |
65 | struct f2fs_inode_info *fi = F2FS_I(inode); | |
66 | struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb); | |
67 | pgoff_t start_fofs, end_fofs; | |
68 | block_t start_blkaddr; | |
69 | ||
70 | read_lock(&fi->ext.ext_lock); | |
71 | if (fi->ext.len == 0) { | |
72 | read_unlock(&fi->ext.ext_lock); | |
73 | return 0; | |
74 | } | |
75 | ||
76 | sbi->total_hit_ext++; | |
77 | start_fofs = fi->ext.fofs; | |
78 | end_fofs = fi->ext.fofs + fi->ext.len - 1; | |
79 | start_blkaddr = fi->ext.blk_addr; | |
80 | ||
81 | if (pgofs >= start_fofs && pgofs <= end_fofs) { | |
82 | unsigned int blkbits = inode->i_sb->s_blocksize_bits; | |
83 | size_t count; | |
84 | ||
85 | clear_buffer_new(bh_result); | |
86 | map_bh(bh_result, inode->i_sb, | |
87 | start_blkaddr + pgofs - start_fofs); | |
88 | count = end_fofs - pgofs + 1; | |
89 | if (count < (UINT_MAX >> blkbits)) | |
90 | bh_result->b_size = (count << blkbits); | |
91 | else | |
92 | bh_result->b_size = UINT_MAX; | |
93 | ||
94 | sbi->read_hit_ext++; | |
95 | read_unlock(&fi->ext.ext_lock); | |
96 | return 1; | |
97 | } | |
98 | read_unlock(&fi->ext.ext_lock); | |
99 | return 0; | |
100 | } | |
101 | ||
102 | void update_extent_cache(block_t blk_addr, struct dnode_of_data *dn) | |
103 | { | |
104 | struct f2fs_inode_info *fi = F2FS_I(dn->inode); | |
105 | pgoff_t fofs, start_fofs, end_fofs; | |
106 | block_t start_blkaddr, end_blkaddr; | |
107 | ||
108 | BUG_ON(blk_addr == NEW_ADDR); | |
109 | fofs = start_bidx_of_node(ofs_of_node(dn->node_page)) + dn->ofs_in_node; | |
110 | ||
111 | /* Update the page address in the parent node */ | |
112 | __set_data_blkaddr(dn, blk_addr); | |
113 | ||
114 | write_lock(&fi->ext.ext_lock); | |
115 | ||
116 | start_fofs = fi->ext.fofs; | |
117 | end_fofs = fi->ext.fofs + fi->ext.len - 1; | |
118 | start_blkaddr = fi->ext.blk_addr; | |
119 | end_blkaddr = fi->ext.blk_addr + fi->ext.len - 1; | |
120 | ||
121 | /* Drop and initialize the matched extent */ | |
122 | if (fi->ext.len == 1 && fofs == start_fofs) | |
123 | fi->ext.len = 0; | |
124 | ||
125 | /* Initial extent */ | |
126 | if (fi->ext.len == 0) { | |
127 | if (blk_addr != NULL_ADDR) { | |
128 | fi->ext.fofs = fofs; | |
129 | fi->ext.blk_addr = blk_addr; | |
130 | fi->ext.len = 1; | |
131 | } | |
132 | goto end_update; | |
133 | } | |
134 | ||
135 | /* Frone merge */ | |
136 | if (fofs == start_fofs - 1 && blk_addr == start_blkaddr - 1) { | |
137 | fi->ext.fofs--; | |
138 | fi->ext.blk_addr--; | |
139 | fi->ext.len++; | |
140 | goto end_update; | |
141 | } | |
142 | ||
143 | /* Back merge */ | |
144 | if (fofs == end_fofs + 1 && blk_addr == end_blkaddr + 1) { | |
145 | fi->ext.len++; | |
146 | goto end_update; | |
147 | } | |
148 | ||
149 | /* Split the existing extent */ | |
150 | if (fi->ext.len > 1 && | |
151 | fofs >= start_fofs && fofs <= end_fofs) { | |
152 | if ((end_fofs - fofs) < (fi->ext.len >> 1)) { | |
153 | fi->ext.len = fofs - start_fofs; | |
154 | } else { | |
155 | fi->ext.fofs = fofs + 1; | |
156 | fi->ext.blk_addr = start_blkaddr + | |
157 | fofs - start_fofs + 1; | |
158 | fi->ext.len -= fofs - start_fofs + 1; | |
159 | } | |
160 | goto end_update; | |
161 | } | |
162 | write_unlock(&fi->ext.ext_lock); | |
163 | return; | |
164 | ||
165 | end_update: | |
166 | write_unlock(&fi->ext.ext_lock); | |
167 | sync_inode_page(dn); | |
168 | return; | |
169 | } | |
170 | ||
171 | struct page *find_data_page(struct inode *inode, pgoff_t index) | |
172 | { | |
173 | struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb); | |
174 | struct address_space *mapping = inode->i_mapping; | |
175 | struct dnode_of_data dn; | |
176 | struct page *page; | |
177 | int err; | |
178 | ||
179 | page = find_get_page(mapping, index); | |
180 | if (page && PageUptodate(page)) | |
181 | return page; | |
182 | f2fs_put_page(page, 0); | |
183 | ||
184 | set_new_dnode(&dn, inode, NULL, NULL, 0); | |
185 | err = get_dnode_of_data(&dn, index, RDONLY_NODE); | |
186 | if (err) | |
187 | return ERR_PTR(err); | |
188 | f2fs_put_dnode(&dn); | |
189 | ||
190 | if (dn.data_blkaddr == NULL_ADDR) | |
191 | return ERR_PTR(-ENOENT); | |
192 | ||
193 | /* By fallocate(), there is no cached page, but with NEW_ADDR */ | |
194 | if (dn.data_blkaddr == NEW_ADDR) | |
195 | return ERR_PTR(-EINVAL); | |
196 | ||
197 | page = grab_cache_page(mapping, index); | |
198 | if (!page) | |
199 | return ERR_PTR(-ENOMEM); | |
200 | ||
201 | err = f2fs_readpage(sbi, page, dn.data_blkaddr, READ_SYNC); | |
202 | if (err) { | |
203 | f2fs_put_page(page, 1); | |
204 | return ERR_PTR(err); | |
205 | } | |
206 | unlock_page(page); | |
207 | return page; | |
208 | } | |
209 | ||
0a8165d7 | 210 | /* |
eb47b800 JK |
211 | * If it tries to access a hole, return an error. |
212 | * Because, the callers, functions in dir.c and GC, should be able to know | |
213 | * whether this page exists or not. | |
214 | */ | |
215 | struct page *get_lock_data_page(struct inode *inode, pgoff_t index) | |
216 | { | |
217 | struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb); | |
218 | struct address_space *mapping = inode->i_mapping; | |
219 | struct dnode_of_data dn; | |
220 | struct page *page; | |
221 | int err; | |
222 | ||
223 | set_new_dnode(&dn, inode, NULL, NULL, 0); | |
224 | err = get_dnode_of_data(&dn, index, RDONLY_NODE); | |
225 | if (err) | |
226 | return ERR_PTR(err); | |
227 | f2fs_put_dnode(&dn); | |
228 | ||
229 | if (dn.data_blkaddr == NULL_ADDR) | |
230 | return ERR_PTR(-ENOENT); | |
231 | ||
232 | page = grab_cache_page(mapping, index); | |
233 | if (!page) | |
234 | return ERR_PTR(-ENOMEM); | |
235 | ||
236 | if (PageUptodate(page)) | |
237 | return page; | |
238 | ||
239 | BUG_ON(dn.data_blkaddr == NEW_ADDR); | |
240 | BUG_ON(dn.data_blkaddr == NULL_ADDR); | |
241 | ||
242 | err = f2fs_readpage(sbi, page, dn.data_blkaddr, READ_SYNC); | |
243 | if (err) { | |
244 | f2fs_put_page(page, 1); | |
245 | return ERR_PTR(err); | |
246 | } | |
247 | return page; | |
248 | } | |
249 | ||
0a8165d7 | 250 | /* |
eb47b800 JK |
251 | * Caller ensures that this data page is never allocated. |
252 | * A new zero-filled data page is allocated in the page cache. | |
253 | */ | |
254 | struct page *get_new_data_page(struct inode *inode, pgoff_t index, | |
255 | bool new_i_size) | |
256 | { | |
257 | struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb); | |
258 | struct address_space *mapping = inode->i_mapping; | |
259 | struct page *page; | |
260 | struct dnode_of_data dn; | |
261 | int err; | |
262 | ||
263 | set_new_dnode(&dn, inode, NULL, NULL, 0); | |
264 | err = get_dnode_of_data(&dn, index, 0); | |
265 | if (err) | |
266 | return ERR_PTR(err); | |
267 | ||
268 | if (dn.data_blkaddr == NULL_ADDR) { | |
269 | if (reserve_new_block(&dn)) { | |
270 | f2fs_put_dnode(&dn); | |
271 | return ERR_PTR(-ENOSPC); | |
272 | } | |
273 | } | |
274 | f2fs_put_dnode(&dn); | |
275 | ||
276 | page = grab_cache_page(mapping, index); | |
277 | if (!page) | |
278 | return ERR_PTR(-ENOMEM); | |
279 | ||
280 | if (PageUptodate(page)) | |
281 | return page; | |
282 | ||
283 | if (dn.data_blkaddr == NEW_ADDR) { | |
284 | zero_user_segment(page, 0, PAGE_CACHE_SIZE); | |
285 | } else { | |
286 | err = f2fs_readpage(sbi, page, dn.data_blkaddr, READ_SYNC); | |
287 | if (err) { | |
288 | f2fs_put_page(page, 1); | |
289 | return ERR_PTR(err); | |
290 | } | |
291 | } | |
292 | SetPageUptodate(page); | |
293 | ||
294 | if (new_i_size && | |
295 | i_size_read(inode) < ((index + 1) << PAGE_CACHE_SHIFT)) { | |
296 | i_size_write(inode, ((index + 1) << PAGE_CACHE_SHIFT)); | |
297 | mark_inode_dirty_sync(inode); | |
298 | } | |
299 | return page; | |
300 | } | |
301 | ||
302 | static void read_end_io(struct bio *bio, int err) | |
303 | { | |
304 | const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); | |
305 | struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1; | |
306 | ||
307 | do { | |
308 | struct page *page = bvec->bv_page; | |
309 | ||
310 | if (--bvec >= bio->bi_io_vec) | |
311 | prefetchw(&bvec->bv_page->flags); | |
312 | ||
313 | if (uptodate) { | |
314 | SetPageUptodate(page); | |
315 | } else { | |
316 | ClearPageUptodate(page); | |
317 | SetPageError(page); | |
318 | } | |
319 | unlock_page(page); | |
320 | } while (bvec >= bio->bi_io_vec); | |
321 | kfree(bio->bi_private); | |
322 | bio_put(bio); | |
323 | } | |
324 | ||
0a8165d7 | 325 | /* |
eb47b800 JK |
326 | * Fill the locked page with data located in the block address. |
327 | * Read operation is synchronous, and caller must unlock the page. | |
328 | */ | |
329 | int f2fs_readpage(struct f2fs_sb_info *sbi, struct page *page, | |
330 | block_t blk_addr, int type) | |
331 | { | |
332 | struct block_device *bdev = sbi->sb->s_bdev; | |
333 | bool sync = (type == READ_SYNC); | |
334 | struct bio *bio; | |
335 | ||
336 | /* This page can be already read by other threads */ | |
337 | if (PageUptodate(page)) { | |
338 | if (!sync) | |
339 | unlock_page(page); | |
340 | return 0; | |
341 | } | |
342 | ||
343 | down_read(&sbi->bio_sem); | |
344 | ||
345 | /* Allocate a new bio */ | |
3cd8a239 | 346 | bio = f2fs_bio_alloc(bdev, 1); |
eb47b800 JK |
347 | |
348 | /* Initialize the bio */ | |
3cd8a239 | 349 | bio->bi_sector = SECTOR_FROM_BLOCK(sbi, blk_addr); |
eb47b800 | 350 | bio->bi_end_io = read_end_io; |
3cd8a239 | 351 | |
eb47b800 JK |
352 | if (bio_add_page(bio, page, PAGE_CACHE_SIZE, 0) < PAGE_CACHE_SIZE) { |
353 | kfree(bio->bi_private); | |
354 | bio_put(bio); | |
355 | up_read(&sbi->bio_sem); | |
356 | return -EFAULT; | |
357 | } | |
358 | ||
359 | submit_bio(type, bio); | |
360 | up_read(&sbi->bio_sem); | |
361 | ||
362 | /* wait for read completion if sync */ | |
363 | if (sync) { | |
364 | lock_page(page); | |
365 | if (PageError(page)) | |
366 | return -EIO; | |
367 | } | |
368 | return 0; | |
369 | } | |
370 | ||
0a8165d7 | 371 | /* |
eb47b800 JK |
372 | * This function should be used by the data read flow only where it |
373 | * does not check the "create" flag that indicates block allocation. | |
374 | * The reason for this special functionality is to exploit VFS readahead | |
375 | * mechanism. | |
376 | */ | |
377 | static int get_data_block_ro(struct inode *inode, sector_t iblock, | |
378 | struct buffer_head *bh_result, int create) | |
379 | { | |
380 | unsigned int blkbits = inode->i_sb->s_blocksize_bits; | |
381 | unsigned maxblocks = bh_result->b_size >> blkbits; | |
382 | struct dnode_of_data dn; | |
383 | pgoff_t pgofs; | |
384 | int err; | |
385 | ||
386 | /* Get the page offset from the block offset(iblock) */ | |
387 | pgofs = (pgoff_t)(iblock >> (PAGE_CACHE_SHIFT - blkbits)); | |
388 | ||
389 | if (check_extent_cache(inode, pgofs, bh_result)) | |
390 | return 0; | |
391 | ||
392 | /* When reading holes, we need its node page */ | |
393 | set_new_dnode(&dn, inode, NULL, NULL, 0); | |
394 | err = get_dnode_of_data(&dn, pgofs, RDONLY_NODE); | |
395 | if (err) | |
396 | return (err == -ENOENT) ? 0 : err; | |
397 | ||
398 | /* It does not support data allocation */ | |
399 | BUG_ON(create); | |
400 | ||
401 | if (dn.data_blkaddr != NEW_ADDR && dn.data_blkaddr != NULL_ADDR) { | |
402 | int i; | |
403 | unsigned int end_offset; | |
404 | ||
405 | end_offset = IS_INODE(dn.node_page) ? | |
406 | ADDRS_PER_INODE : | |
407 | ADDRS_PER_BLOCK; | |
408 | ||
409 | clear_buffer_new(bh_result); | |
410 | ||
411 | /* Give more consecutive addresses for the read ahead */ | |
412 | for (i = 0; i < end_offset - dn.ofs_in_node; i++) | |
413 | if (((datablock_addr(dn.node_page, | |
414 | dn.ofs_in_node + i)) | |
415 | != (dn.data_blkaddr + i)) || maxblocks == i) | |
416 | break; | |
417 | map_bh(bh_result, inode->i_sb, dn.data_blkaddr); | |
418 | bh_result->b_size = (i << blkbits); | |
419 | } | |
420 | f2fs_put_dnode(&dn); | |
421 | return 0; | |
422 | } | |
423 | ||
424 | static int f2fs_read_data_page(struct file *file, struct page *page) | |
425 | { | |
426 | return mpage_readpage(page, get_data_block_ro); | |
427 | } | |
428 | ||
429 | static int f2fs_read_data_pages(struct file *file, | |
430 | struct address_space *mapping, | |
431 | struct list_head *pages, unsigned nr_pages) | |
432 | { | |
433 | return mpage_readpages(mapping, pages, nr_pages, get_data_block_ro); | |
434 | } | |
435 | ||
436 | int do_write_data_page(struct page *page) | |
437 | { | |
438 | struct inode *inode = page->mapping->host; | |
439 | struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb); | |
440 | block_t old_blk_addr, new_blk_addr; | |
441 | struct dnode_of_data dn; | |
442 | int err = 0; | |
443 | ||
444 | set_new_dnode(&dn, inode, NULL, NULL, 0); | |
445 | err = get_dnode_of_data(&dn, page->index, RDONLY_NODE); | |
446 | if (err) | |
447 | return err; | |
448 | ||
449 | old_blk_addr = dn.data_blkaddr; | |
450 | ||
451 | /* This page is already truncated */ | |
452 | if (old_blk_addr == NULL_ADDR) | |
453 | goto out_writepage; | |
454 | ||
455 | set_page_writeback(page); | |
456 | ||
457 | /* | |
458 | * If current allocation needs SSR, | |
459 | * it had better in-place writes for updated data. | |
460 | */ | |
461 | if (old_blk_addr != NEW_ADDR && !is_cold_data(page) && | |
462 | need_inplace_update(inode)) { | |
463 | rewrite_data_page(F2FS_SB(inode->i_sb), page, | |
464 | old_blk_addr); | |
465 | } else { | |
466 | write_data_page(inode, page, &dn, | |
467 | old_blk_addr, &new_blk_addr); | |
468 | update_extent_cache(new_blk_addr, &dn); | |
469 | F2FS_I(inode)->data_version = | |
470 | le64_to_cpu(F2FS_CKPT(sbi)->checkpoint_ver); | |
471 | } | |
472 | out_writepage: | |
473 | f2fs_put_dnode(&dn); | |
474 | return err; | |
475 | } | |
476 | ||
477 | static int f2fs_write_data_page(struct page *page, | |
478 | struct writeback_control *wbc) | |
479 | { | |
480 | struct inode *inode = page->mapping->host; | |
481 | struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb); | |
482 | loff_t i_size = i_size_read(inode); | |
483 | const pgoff_t end_index = ((unsigned long long) i_size) | |
484 | >> PAGE_CACHE_SHIFT; | |
485 | unsigned offset; | |
486 | int err = 0; | |
487 | ||
488 | if (page->index < end_index) | |
489 | goto out; | |
490 | ||
491 | /* | |
492 | * If the offset is out-of-range of file size, | |
493 | * this page does not have to be written to disk. | |
494 | */ | |
495 | offset = i_size & (PAGE_CACHE_SIZE - 1); | |
496 | if ((page->index >= end_index + 1) || !offset) { | |
497 | if (S_ISDIR(inode->i_mode)) { | |
498 | dec_page_count(sbi, F2FS_DIRTY_DENTS); | |
499 | inode_dec_dirty_dents(inode); | |
500 | } | |
501 | goto unlock_out; | |
502 | } | |
503 | ||
504 | zero_user_segment(page, offset, PAGE_CACHE_SIZE); | |
505 | out: | |
506 | if (sbi->por_doing) | |
507 | goto redirty_out; | |
508 | ||
509 | if (wbc->for_reclaim && !S_ISDIR(inode->i_mode) && !is_cold_data(page)) | |
510 | goto redirty_out; | |
511 | ||
512 | mutex_lock_op(sbi, DATA_WRITE); | |
513 | if (S_ISDIR(inode->i_mode)) { | |
514 | dec_page_count(sbi, F2FS_DIRTY_DENTS); | |
515 | inode_dec_dirty_dents(inode); | |
516 | } | |
517 | err = do_write_data_page(page); | |
518 | if (err && err != -ENOENT) { | |
519 | wbc->pages_skipped++; | |
520 | set_page_dirty(page); | |
521 | } | |
522 | mutex_unlock_op(sbi, DATA_WRITE); | |
523 | ||
524 | if (wbc->for_reclaim) | |
525 | f2fs_submit_bio(sbi, DATA, true); | |
526 | ||
527 | if (err == -ENOENT) | |
528 | goto unlock_out; | |
529 | ||
530 | clear_cold_data(page); | |
531 | unlock_page(page); | |
532 | ||
533 | if (!wbc->for_reclaim && !S_ISDIR(inode->i_mode)) | |
534 | f2fs_balance_fs(sbi); | |
535 | return 0; | |
536 | ||
537 | unlock_out: | |
538 | unlock_page(page); | |
539 | return (err == -ENOENT) ? 0 : err; | |
540 | ||
541 | redirty_out: | |
542 | wbc->pages_skipped++; | |
543 | set_page_dirty(page); | |
544 | return AOP_WRITEPAGE_ACTIVATE; | |
545 | } | |
546 | ||
547 | #define MAX_DESIRED_PAGES_WP 4096 | |
548 | ||
25ca923b | 549 | static int f2fs_write_data_pages(struct address_space *mapping, |
eb47b800 JK |
550 | struct writeback_control *wbc) |
551 | { | |
552 | struct inode *inode = mapping->host; | |
553 | struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb); | |
554 | int ret; | |
555 | long excess_nrtw = 0, desired_nrtw; | |
556 | ||
557 | if (wbc->nr_to_write < MAX_DESIRED_PAGES_WP) { | |
558 | desired_nrtw = MAX_DESIRED_PAGES_WP; | |
559 | excess_nrtw = desired_nrtw - wbc->nr_to_write; | |
560 | wbc->nr_to_write = desired_nrtw; | |
561 | } | |
562 | ||
563 | if (!S_ISDIR(inode->i_mode)) | |
564 | mutex_lock(&sbi->writepages); | |
565 | ret = generic_writepages(mapping, wbc); | |
566 | if (!S_ISDIR(inode->i_mode)) | |
567 | mutex_unlock(&sbi->writepages); | |
568 | f2fs_submit_bio(sbi, DATA, (wbc->sync_mode == WB_SYNC_ALL)); | |
569 | ||
570 | remove_dirty_dir_inode(inode); | |
571 | ||
572 | wbc->nr_to_write -= excess_nrtw; | |
573 | return ret; | |
574 | } | |
575 | ||
576 | static int f2fs_write_begin(struct file *file, struct address_space *mapping, | |
577 | loff_t pos, unsigned len, unsigned flags, | |
578 | struct page **pagep, void **fsdata) | |
579 | { | |
580 | struct inode *inode = mapping->host; | |
581 | struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb); | |
582 | struct page *page; | |
583 | pgoff_t index = ((unsigned long long) pos) >> PAGE_CACHE_SHIFT; | |
584 | struct dnode_of_data dn; | |
585 | int err = 0; | |
586 | ||
587 | /* for nobh_write_end */ | |
588 | *fsdata = NULL; | |
589 | ||
590 | f2fs_balance_fs(sbi); | |
591 | ||
592 | page = grab_cache_page_write_begin(mapping, index, flags); | |
593 | if (!page) | |
594 | return -ENOMEM; | |
595 | *pagep = page; | |
596 | ||
597 | mutex_lock_op(sbi, DATA_NEW); | |
598 | ||
599 | set_new_dnode(&dn, inode, NULL, NULL, 0); | |
600 | err = get_dnode_of_data(&dn, index, 0); | |
601 | if (err) { | |
602 | mutex_unlock_op(sbi, DATA_NEW); | |
603 | f2fs_put_page(page, 1); | |
604 | return err; | |
605 | } | |
606 | ||
607 | if (dn.data_blkaddr == NULL_ADDR) { | |
608 | err = reserve_new_block(&dn); | |
609 | if (err) { | |
610 | f2fs_put_dnode(&dn); | |
611 | mutex_unlock_op(sbi, DATA_NEW); | |
612 | f2fs_put_page(page, 1); | |
613 | return err; | |
614 | } | |
615 | } | |
616 | f2fs_put_dnode(&dn); | |
617 | ||
618 | mutex_unlock_op(sbi, DATA_NEW); | |
619 | ||
620 | if ((len == PAGE_CACHE_SIZE) || PageUptodate(page)) | |
621 | return 0; | |
622 | ||
623 | if ((pos & PAGE_CACHE_MASK) >= i_size_read(inode)) { | |
624 | unsigned start = pos & (PAGE_CACHE_SIZE - 1); | |
625 | unsigned end = start + len; | |
626 | ||
627 | /* Reading beyond i_size is simple: memset to zero */ | |
628 | zero_user_segments(page, 0, start, end, PAGE_CACHE_SIZE); | |
629 | return 0; | |
630 | } | |
631 | ||
632 | if (dn.data_blkaddr == NEW_ADDR) { | |
633 | zero_user_segment(page, 0, PAGE_CACHE_SIZE); | |
634 | } else { | |
635 | err = f2fs_readpage(sbi, page, dn.data_blkaddr, READ_SYNC); | |
636 | if (err) { | |
637 | f2fs_put_page(page, 1); | |
638 | return err; | |
639 | } | |
640 | } | |
641 | SetPageUptodate(page); | |
642 | clear_cold_data(page); | |
643 | return 0; | |
644 | } | |
645 | ||
646 | static ssize_t f2fs_direct_IO(int rw, struct kiocb *iocb, | |
647 | const struct iovec *iov, loff_t offset, unsigned long nr_segs) | |
648 | { | |
649 | struct file *file = iocb->ki_filp; | |
650 | struct inode *inode = file->f_mapping->host; | |
651 | ||
652 | if (rw == WRITE) | |
653 | return 0; | |
654 | ||
655 | /* Needs synchronization with the cleaner */ | |
656 | return blockdev_direct_IO(rw, iocb, inode, iov, offset, nr_segs, | |
657 | get_data_block_ro); | |
658 | } | |
659 | ||
660 | static void f2fs_invalidate_data_page(struct page *page, unsigned long offset) | |
661 | { | |
662 | struct inode *inode = page->mapping->host; | |
663 | struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb); | |
664 | if (S_ISDIR(inode->i_mode) && PageDirty(page)) { | |
665 | dec_page_count(sbi, F2FS_DIRTY_DENTS); | |
666 | inode_dec_dirty_dents(inode); | |
667 | } | |
668 | ClearPagePrivate(page); | |
669 | } | |
670 | ||
671 | static int f2fs_release_data_page(struct page *page, gfp_t wait) | |
672 | { | |
673 | ClearPagePrivate(page); | |
674 | return 0; | |
675 | } | |
676 | ||
677 | static int f2fs_set_data_page_dirty(struct page *page) | |
678 | { | |
679 | struct address_space *mapping = page->mapping; | |
680 | struct inode *inode = mapping->host; | |
681 | ||
682 | SetPageUptodate(page); | |
683 | if (!PageDirty(page)) { | |
684 | __set_page_dirty_nobuffers(page); | |
685 | set_dirty_dir_page(inode, page); | |
686 | return 1; | |
687 | } | |
688 | return 0; | |
689 | } | |
690 | ||
691 | const struct address_space_operations f2fs_dblock_aops = { | |
692 | .readpage = f2fs_read_data_page, | |
693 | .readpages = f2fs_read_data_pages, | |
694 | .writepage = f2fs_write_data_page, | |
695 | .writepages = f2fs_write_data_pages, | |
696 | .write_begin = f2fs_write_begin, | |
697 | .write_end = nobh_write_end, | |
698 | .set_page_dirty = f2fs_set_data_page_dirty, | |
699 | .invalidatepage = f2fs_invalidate_data_page, | |
700 | .releasepage = f2fs_release_data_page, | |
701 | .direct_IO = f2fs_direct_IO, | |
702 | }; |