Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * fs/fs-writeback.c | |
3 | * | |
4 | * Copyright (C) 2002, Linus Torvalds. | |
5 | * | |
6 | * Contains all the functions related to writing back and waiting | |
7 | * upon dirty inodes against superblocks, and writing back dirty | |
8 | * pages against inodes. ie: data writeback. Writeout of the | |
9 | * inode itself is not handled here. | |
10 | * | |
e1f8e874 | 11 | * 10Apr2002 Andrew Morton |
1da177e4 LT |
12 | * Split out of fs/inode.c |
13 | * Additions for address_space-based writeback | |
14 | */ | |
15 | ||
16 | #include <linux/kernel.h> | |
630d9c47 | 17 | #include <linux/export.h> |
1da177e4 | 18 | #include <linux/spinlock.h> |
5a0e3ad6 | 19 | #include <linux/slab.h> |
1da177e4 LT |
20 | #include <linux/sched.h> |
21 | #include <linux/fs.h> | |
22 | #include <linux/mm.h> | |
bc31b86a | 23 | #include <linux/pagemap.h> |
03ba3782 JA |
24 | #include <linux/kthread.h> |
25 | #include <linux/freezer.h> | |
1da177e4 LT |
26 | #include <linux/writeback.h> |
27 | #include <linux/blkdev.h> | |
28 | #include <linux/backing-dev.h> | |
455b2864 | 29 | #include <linux/tracepoint.h> |
07f3f05c | 30 | #include "internal.h" |
1da177e4 | 31 | |
bc31b86a WF |
32 | /* |
33 | * 4MB minimal write chunk size | |
34 | */ | |
35 | #define MIN_WRITEBACK_PAGES (4096UL >> (PAGE_CACHE_SHIFT - 10)) | |
36 | ||
c4a77a6c JA |
37 | /* |
38 | * Passed into wb_writeback(), essentially a subset of writeback_control | |
39 | */ | |
83ba7b07 | 40 | struct wb_writeback_work { |
c4a77a6c JA |
41 | long nr_pages; |
42 | struct super_block *sb; | |
d46db3d5 | 43 | unsigned long *older_than_this; |
c4a77a6c | 44 | enum writeback_sync_modes sync_mode; |
6e6938b6 | 45 | unsigned int tagged_writepages:1; |
52957fe1 HS |
46 | unsigned int for_kupdate:1; |
47 | unsigned int range_cyclic:1; | |
48 | unsigned int for_background:1; | |
0e175a18 | 49 | enum wb_reason reason; /* why was writeback initiated? */ |
c4a77a6c | 50 | |
8010c3b6 | 51 | struct list_head list; /* pending work list */ |
83ba7b07 | 52 | struct completion *done; /* set if the caller waits */ |
03ba3782 JA |
53 | }; |
54 | ||
f11b00f3 AB |
55 | /** |
56 | * writeback_in_progress - determine whether there is writeback in progress | |
57 | * @bdi: the device's backing_dev_info structure. | |
58 | * | |
03ba3782 JA |
59 | * Determine whether there is writeback waiting to be handled against a |
60 | * backing device. | |
f11b00f3 AB |
61 | */ |
62 | int writeback_in_progress(struct backing_dev_info *bdi) | |
63 | { | |
81d73a32 | 64 | return test_bit(BDI_writeback_running, &bdi->state); |
f11b00f3 AB |
65 | } |
66 | ||
692ebd17 JK |
67 | static inline struct backing_dev_info *inode_to_bdi(struct inode *inode) |
68 | { | |
69 | struct super_block *sb = inode->i_sb; | |
692ebd17 | 70 | |
aaead25b CH |
71 | if (strcmp(sb->s_type->name, "bdev") == 0) |
72 | return inode->i_mapping->backing_dev_info; | |
73 | ||
74 | return sb->s_bdi; | |
692ebd17 JK |
75 | } |
76 | ||
7ccf19a8 NP |
77 | static inline struct inode *wb_inode(struct list_head *head) |
78 | { | |
79 | return list_entry(head, struct inode, i_wb_list); | |
80 | } | |
81 | ||
15eb77a0 WF |
82 | /* |
83 | * Include the creation of the trace points after defining the | |
84 | * wb_writeback_work structure and inline functions so that the definition | |
85 | * remains local to this file. | |
86 | */ | |
87 | #define CREATE_TRACE_POINTS | |
88 | #include <trace/events/writeback.h> | |
89 | ||
6585027a JK |
90 | /* Wakeup flusher thread or forker thread to fork it. Requires bdi->wb_lock. */ |
91 | static void bdi_wakeup_flusher(struct backing_dev_info *bdi) | |
03ba3782 | 92 | { |
fff5b85a AB |
93 | if (bdi->wb.task) { |
94 | wake_up_process(bdi->wb.task); | |
95 | } else { | |
96 | /* | |
97 | * The bdi thread isn't there, wake up the forker thread which | |
98 | * will create and run it. | |
99 | */ | |
03ba3782 | 100 | wake_up_process(default_backing_dev_info.wb.task); |
1da177e4 | 101 | } |
6585027a JK |
102 | } |
103 | ||
104 | static void bdi_queue_work(struct backing_dev_info *bdi, | |
105 | struct wb_writeback_work *work) | |
106 | { | |
107 | trace_writeback_queue(bdi, work); | |
108 | ||
109 | spin_lock_bh(&bdi->wb_lock); | |
110 | list_add_tail(&work->list, &bdi->work_list); | |
111 | if (!bdi->wb.task) | |
112 | trace_writeback_nothread(bdi, work); | |
113 | bdi_wakeup_flusher(bdi); | |
6467716a | 114 | spin_unlock_bh(&bdi->wb_lock); |
1da177e4 LT |
115 | } |
116 | ||
83ba7b07 CH |
117 | static void |
118 | __bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages, | |
0e175a18 | 119 | bool range_cyclic, enum wb_reason reason) |
1da177e4 | 120 | { |
83ba7b07 | 121 | struct wb_writeback_work *work; |
03ba3782 | 122 | |
bcddc3f0 JA |
123 | /* |
124 | * This is WB_SYNC_NONE writeback, so if allocation fails just | |
125 | * wakeup the thread for old dirty data writeback | |
126 | */ | |
83ba7b07 CH |
127 | work = kzalloc(sizeof(*work), GFP_ATOMIC); |
128 | if (!work) { | |
455b2864 DC |
129 | if (bdi->wb.task) { |
130 | trace_writeback_nowork(bdi); | |
83ba7b07 | 131 | wake_up_process(bdi->wb.task); |
455b2864 | 132 | } |
83ba7b07 | 133 | return; |
bcddc3f0 | 134 | } |
03ba3782 | 135 | |
83ba7b07 CH |
136 | work->sync_mode = WB_SYNC_NONE; |
137 | work->nr_pages = nr_pages; | |
138 | work->range_cyclic = range_cyclic; | |
0e175a18 | 139 | work->reason = reason; |
03ba3782 | 140 | |
83ba7b07 | 141 | bdi_queue_work(bdi, work); |
b6e51316 JA |
142 | } |
143 | ||
144 | /** | |
145 | * bdi_start_writeback - start writeback | |
146 | * @bdi: the backing device to write from | |
147 | * @nr_pages: the number of pages to write | |
786228ab | 148 | * @reason: reason why some writeback work was initiated |
b6e51316 JA |
149 | * |
150 | * Description: | |
151 | * This does WB_SYNC_NONE opportunistic writeback. The IO is only | |
25985edc | 152 | * started when this function returns, we make no guarantees on |
0e3c9a22 | 153 | * completion. Caller need not hold sb s_umount semaphore. |
b6e51316 JA |
154 | * |
155 | */ | |
0e175a18 CW |
156 | void bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages, |
157 | enum wb_reason reason) | |
b6e51316 | 158 | { |
0e175a18 | 159 | __bdi_start_writeback(bdi, nr_pages, true, reason); |
c5444198 | 160 | } |
d3ddec76 | 161 | |
c5444198 CH |
162 | /** |
163 | * bdi_start_background_writeback - start background writeback | |
164 | * @bdi: the backing device to write from | |
165 | * | |
166 | * Description: | |
6585027a JK |
167 | * This makes sure WB_SYNC_NONE background writeback happens. When |
168 | * this function returns, it is only guaranteed that for given BDI | |
169 | * some IO is happening if we are over background dirty threshold. | |
170 | * Caller need not hold sb s_umount semaphore. | |
c5444198 CH |
171 | */ |
172 | void bdi_start_background_writeback(struct backing_dev_info *bdi) | |
173 | { | |
6585027a JK |
174 | /* |
175 | * We just wake up the flusher thread. It will perform background | |
176 | * writeback as soon as there is no other work to do. | |
177 | */ | |
71927e84 | 178 | trace_writeback_wake_background(bdi); |
6585027a JK |
179 | spin_lock_bh(&bdi->wb_lock); |
180 | bdi_wakeup_flusher(bdi); | |
181 | spin_unlock_bh(&bdi->wb_lock); | |
1da177e4 LT |
182 | } |
183 | ||
a66979ab DC |
184 | /* |
185 | * Remove the inode from the writeback list it is on. | |
186 | */ | |
187 | void inode_wb_list_del(struct inode *inode) | |
188 | { | |
f758eeab CH |
189 | struct backing_dev_info *bdi = inode_to_bdi(inode); |
190 | ||
191 | spin_lock(&bdi->wb.list_lock); | |
a66979ab | 192 | list_del_init(&inode->i_wb_list); |
f758eeab | 193 | spin_unlock(&bdi->wb.list_lock); |
a66979ab DC |
194 | } |
195 | ||
6610a0bc AM |
196 | /* |
197 | * Redirty an inode: set its when-it-was dirtied timestamp and move it to the | |
198 | * furthest end of its superblock's dirty-inode list. | |
199 | * | |
200 | * Before stamping the inode's ->dirtied_when, we check to see whether it is | |
66f3b8e2 | 201 | * already the most-recently-dirtied inode on the b_dirty list. If that is |
6610a0bc AM |
202 | * the case then the inode must have been redirtied while it was being written |
203 | * out and we don't reset its dirtied_when. | |
204 | */ | |
f758eeab | 205 | static void redirty_tail(struct inode *inode, struct bdi_writeback *wb) |
6610a0bc | 206 | { |
f758eeab | 207 | assert_spin_locked(&wb->list_lock); |
03ba3782 | 208 | if (!list_empty(&wb->b_dirty)) { |
66f3b8e2 | 209 | struct inode *tail; |
6610a0bc | 210 | |
7ccf19a8 | 211 | tail = wb_inode(wb->b_dirty.next); |
66f3b8e2 | 212 | if (time_before(inode->dirtied_when, tail->dirtied_when)) |
6610a0bc AM |
213 | inode->dirtied_when = jiffies; |
214 | } | |
7ccf19a8 | 215 | list_move(&inode->i_wb_list, &wb->b_dirty); |
6610a0bc AM |
216 | } |
217 | ||
c986d1e2 | 218 | /* |
66f3b8e2 | 219 | * requeue inode for re-scanning after bdi->b_io list is exhausted. |
c986d1e2 | 220 | */ |
f758eeab | 221 | static void requeue_io(struct inode *inode, struct bdi_writeback *wb) |
c986d1e2 | 222 | { |
f758eeab | 223 | assert_spin_locked(&wb->list_lock); |
7ccf19a8 | 224 | list_move(&inode->i_wb_list, &wb->b_more_io); |
c986d1e2 AM |
225 | } |
226 | ||
1c0eeaf5 JE |
227 | static void inode_sync_complete(struct inode *inode) |
228 | { | |
365b94ae JK |
229 | inode->i_state &= ~I_SYNC; |
230 | /* Waiters must see I_SYNC cleared before being woken up */ | |
1c0eeaf5 JE |
231 | smp_mb(); |
232 | wake_up_bit(&inode->i_state, __I_SYNC); | |
233 | } | |
234 | ||
d2caa3c5 JL |
235 | static bool inode_dirtied_after(struct inode *inode, unsigned long t) |
236 | { | |
237 | bool ret = time_after(inode->dirtied_when, t); | |
238 | #ifndef CONFIG_64BIT | |
239 | /* | |
240 | * For inodes being constantly redirtied, dirtied_when can get stuck. | |
241 | * It _appears_ to be in the future, but is actually in distant past. | |
242 | * This test is necessary to prevent such wrapped-around relative times | |
5b0830cb | 243 | * from permanently stopping the whole bdi writeback. |
d2caa3c5 JL |
244 | */ |
245 | ret = ret && time_before_eq(inode->dirtied_when, jiffies); | |
246 | #endif | |
247 | return ret; | |
248 | } | |
249 | ||
2c136579 | 250 | /* |
697e6fed JK |
251 | * Move expired (dirtied after work->older_than_this) dirty inodes from |
252 | * @delaying_queue to @dispatch_queue. | |
2c136579 | 253 | */ |
e84d0a4f | 254 | static int move_expired_inodes(struct list_head *delaying_queue, |
2c136579 | 255 | struct list_head *dispatch_queue, |
ad4e38dd | 256 | struct wb_writeback_work *work) |
2c136579 | 257 | { |
5c03449d SL |
258 | LIST_HEAD(tmp); |
259 | struct list_head *pos, *node; | |
cf137307 | 260 | struct super_block *sb = NULL; |
5c03449d | 261 | struct inode *inode; |
cf137307 | 262 | int do_sb_sort = 0; |
e84d0a4f | 263 | int moved = 0; |
5c03449d | 264 | |
2c136579 | 265 | while (!list_empty(delaying_queue)) { |
7ccf19a8 | 266 | inode = wb_inode(delaying_queue->prev); |
ad4e38dd CW |
267 | if (work->older_than_this && |
268 | inode_dirtied_after(inode, *work->older_than_this)) | |
2c136579 | 269 | break; |
cf137307 JA |
270 | if (sb && sb != inode->i_sb) |
271 | do_sb_sort = 1; | |
272 | sb = inode->i_sb; | |
7ccf19a8 | 273 | list_move(&inode->i_wb_list, &tmp); |
e84d0a4f | 274 | moved++; |
5c03449d SL |
275 | } |
276 | ||
cf137307 JA |
277 | /* just one sb in list, splice to dispatch_queue and we're done */ |
278 | if (!do_sb_sort) { | |
279 | list_splice(&tmp, dispatch_queue); | |
e84d0a4f | 280 | goto out; |
cf137307 JA |
281 | } |
282 | ||
5c03449d SL |
283 | /* Move inodes from one superblock together */ |
284 | while (!list_empty(&tmp)) { | |
7ccf19a8 | 285 | sb = wb_inode(tmp.prev)->i_sb; |
5c03449d | 286 | list_for_each_prev_safe(pos, node, &tmp) { |
7ccf19a8 | 287 | inode = wb_inode(pos); |
5c03449d | 288 | if (inode->i_sb == sb) |
7ccf19a8 | 289 | list_move(&inode->i_wb_list, dispatch_queue); |
5c03449d | 290 | } |
2c136579 | 291 | } |
e84d0a4f WF |
292 | out: |
293 | return moved; | |
2c136579 FW |
294 | } |
295 | ||
296 | /* | |
297 | * Queue all expired dirty inodes for io, eldest first. | |
4ea879b9 WF |
298 | * Before |
299 | * newly dirtied b_dirty b_io b_more_io | |
300 | * =============> gf edc BA | |
301 | * After | |
302 | * newly dirtied b_dirty b_io b_more_io | |
303 | * =============> g fBAedc | |
304 | * | | |
305 | * +--> dequeue for IO | |
2c136579 | 306 | */ |
ad4e38dd | 307 | static void queue_io(struct bdi_writeback *wb, struct wb_writeback_work *work) |
66f3b8e2 | 308 | { |
e84d0a4f | 309 | int moved; |
f758eeab | 310 | assert_spin_locked(&wb->list_lock); |
4ea879b9 | 311 | list_splice_init(&wb->b_more_io, &wb->b_io); |
ad4e38dd CW |
312 | moved = move_expired_inodes(&wb->b_dirty, &wb->b_io, work); |
313 | trace_writeback_queue_io(wb, work, moved); | |
66f3b8e2 JA |
314 | } |
315 | ||
a9185b41 | 316 | static int write_inode(struct inode *inode, struct writeback_control *wbc) |
08d8e974 | 317 | { |
03ba3782 | 318 | if (inode->i_sb->s_op->write_inode && !is_bad_inode(inode)) |
a9185b41 | 319 | return inode->i_sb->s_op->write_inode(inode, wbc); |
03ba3782 | 320 | return 0; |
08d8e974 | 321 | } |
08d8e974 | 322 | |
1da177e4 | 323 | /* |
169ebd90 JK |
324 | * Wait for writeback on an inode to complete. Called with i_lock held. |
325 | * Caller must make sure inode cannot go away when we drop i_lock. | |
01c03194 | 326 | */ |
169ebd90 JK |
327 | static void __inode_wait_for_writeback(struct inode *inode) |
328 | __releases(inode->i_lock) | |
329 | __acquires(inode->i_lock) | |
01c03194 CH |
330 | { |
331 | DEFINE_WAIT_BIT(wq, &inode->i_state, __I_SYNC); | |
332 | wait_queue_head_t *wqh; | |
333 | ||
334 | wqh = bit_waitqueue(&inode->i_state, __I_SYNC); | |
250df6ed DC |
335 | while (inode->i_state & I_SYNC) { |
336 | spin_unlock(&inode->i_lock); | |
01c03194 | 337 | __wait_on_bit(wqh, &wq, inode_wait, TASK_UNINTERRUPTIBLE); |
250df6ed | 338 | spin_lock(&inode->i_lock); |
58a9d3d8 | 339 | } |
01c03194 CH |
340 | } |
341 | ||
169ebd90 JK |
342 | /* |
343 | * Wait for writeback on an inode to complete. Caller must have inode pinned. | |
344 | */ | |
345 | void inode_wait_for_writeback(struct inode *inode) | |
346 | { | |
347 | spin_lock(&inode->i_lock); | |
348 | __inode_wait_for_writeback(inode); | |
349 | spin_unlock(&inode->i_lock); | |
350 | } | |
351 | ||
352 | /* | |
353 | * Sleep until I_SYNC is cleared. This function must be called with i_lock | |
354 | * held and drops it. It is aimed for callers not holding any inode reference | |
355 | * so once i_lock is dropped, inode can go away. | |
356 | */ | |
357 | static void inode_sleep_on_writeback(struct inode *inode) | |
358 | __releases(inode->i_lock) | |
359 | { | |
360 | DEFINE_WAIT(wait); | |
361 | wait_queue_head_t *wqh = bit_waitqueue(&inode->i_state, __I_SYNC); | |
362 | int sleep; | |
363 | ||
364 | prepare_to_wait(wqh, &wait, TASK_UNINTERRUPTIBLE); | |
365 | sleep = inode->i_state & I_SYNC; | |
366 | spin_unlock(&inode->i_lock); | |
367 | if (sleep) | |
368 | schedule(); | |
369 | finish_wait(wqh, &wait); | |
370 | } | |
371 | ||
ccb26b5a JK |
372 | /* |
373 | * Find proper writeback list for the inode depending on its current state and | |
374 | * possibly also change of its state while we were doing writeback. Here we | |
375 | * handle things such as livelock prevention or fairness of writeback among | |
376 | * inodes. This function can be called only by flusher thread - noone else | |
377 | * processes all inodes in writeback lists and requeueing inodes behind flusher | |
378 | * thread's back can have unexpected consequences. | |
379 | */ | |
380 | static void requeue_inode(struct inode *inode, struct bdi_writeback *wb, | |
381 | struct writeback_control *wbc) | |
382 | { | |
383 | if (inode->i_state & I_FREEING) | |
384 | return; | |
385 | ||
386 | /* | |
387 | * Sync livelock prevention. Each inode is tagged and synced in one | |
388 | * shot. If still dirty, it will be redirty_tail()'ed below. Update | |
389 | * the dirty time to prevent enqueue and sync it again. | |
390 | */ | |
391 | if ((inode->i_state & I_DIRTY) && | |
392 | (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)) | |
393 | inode->dirtied_when = jiffies; | |
394 | ||
4f8ad655 JK |
395 | if (wbc->pages_skipped) { |
396 | /* | |
397 | * writeback is not making progress due to locked | |
398 | * buffers. Skip this inode for now. | |
399 | */ | |
400 | redirty_tail(inode, wb); | |
401 | return; | |
402 | } | |
403 | ||
ccb26b5a JK |
404 | if (mapping_tagged(inode->i_mapping, PAGECACHE_TAG_DIRTY)) { |
405 | /* | |
406 | * We didn't write back all the pages. nfs_writepages() | |
407 | * sometimes bales out without doing anything. | |
408 | */ | |
409 | if (wbc->nr_to_write <= 0) { | |
410 | /* Slice used up. Queue for next turn. */ | |
411 | requeue_io(inode, wb); | |
412 | } else { | |
413 | /* | |
414 | * Writeback blocked by something other than | |
415 | * congestion. Delay the inode for some time to | |
416 | * avoid spinning on the CPU (100% iowait) | |
417 | * retrying writeback of the dirty page/inode | |
418 | * that cannot be performed immediately. | |
419 | */ | |
420 | redirty_tail(inode, wb); | |
421 | } | |
422 | } else if (inode->i_state & I_DIRTY) { | |
423 | /* | |
424 | * Filesystems can dirty the inode during writeback operations, | |
425 | * such as delayed allocation during submission or metadata | |
426 | * updates after data IO completion. | |
427 | */ | |
428 | redirty_tail(inode, wb); | |
429 | } else { | |
430 | /* The inode is clean. Remove from writeback lists. */ | |
431 | list_del_init(&inode->i_wb_list); | |
432 | } | |
433 | } | |
434 | ||
01c03194 | 435 | /* |
4f8ad655 JK |
436 | * Write out an inode and its dirty pages. Do not update the writeback list |
437 | * linkage. That is left to the caller. The caller is also responsible for | |
438 | * setting I_SYNC flag and calling inode_sync_complete() to clear it. | |
1da177e4 LT |
439 | */ |
440 | static int | |
4f8ad655 JK |
441 | __writeback_single_inode(struct inode *inode, struct bdi_writeback *wb, |
442 | struct writeback_control *wbc) | |
1da177e4 | 443 | { |
1da177e4 | 444 | struct address_space *mapping = inode->i_mapping; |
251d6a47 | 445 | long nr_to_write = wbc->nr_to_write; |
01c03194 | 446 | unsigned dirty; |
1da177e4 LT |
447 | int ret; |
448 | ||
4f8ad655 | 449 | WARN_ON(!(inode->i_state & I_SYNC)); |
1da177e4 LT |
450 | |
451 | ret = do_writepages(mapping, wbc); | |
452 | ||
26821ed4 CH |
453 | /* |
454 | * Make sure to wait on the data before writing out the metadata. | |
455 | * This is important for filesystems that modify metadata on data | |
456 | * I/O completion. | |
457 | */ | |
a9185b41 | 458 | if (wbc->sync_mode == WB_SYNC_ALL) { |
26821ed4 | 459 | int err = filemap_fdatawait(mapping); |
1da177e4 LT |
460 | if (ret == 0) |
461 | ret = err; | |
462 | } | |
463 | ||
5547e8aa DM |
464 | /* |
465 | * Some filesystems may redirty the inode during the writeback | |
466 | * due to delalloc, clear dirty metadata flags right before | |
467 | * write_inode() | |
468 | */ | |
250df6ed | 469 | spin_lock(&inode->i_lock); |
6290be1c JK |
470 | /* Clear I_DIRTY_PAGES if we've written out all dirty pages */ |
471 | if (!mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) | |
472 | inode->i_state &= ~I_DIRTY_PAGES; | |
5547e8aa DM |
473 | dirty = inode->i_state & I_DIRTY; |
474 | inode->i_state &= ~(I_DIRTY_SYNC | I_DIRTY_DATASYNC); | |
250df6ed | 475 | spin_unlock(&inode->i_lock); |
26821ed4 CH |
476 | /* Don't write the inode if only I_DIRTY_PAGES was set */ |
477 | if (dirty & (I_DIRTY_SYNC | I_DIRTY_DATASYNC)) { | |
a9185b41 | 478 | int err = write_inode(inode, wbc); |
1da177e4 LT |
479 | if (ret == 0) |
480 | ret = err; | |
481 | } | |
4f8ad655 JK |
482 | trace_writeback_single_inode(inode, wbc, nr_to_write); |
483 | return ret; | |
484 | } | |
485 | ||
486 | /* | |
487 | * Write out an inode's dirty pages. Either the caller has an active reference | |
488 | * on the inode or the inode has I_WILL_FREE set. | |
489 | * | |
490 | * This function is designed to be called for writing back one inode which | |
491 | * we go e.g. from filesystem. Flusher thread uses __writeback_single_inode() | |
492 | * and does more profound writeback list handling in writeback_sb_inodes(). | |
493 | */ | |
494 | static int | |
495 | writeback_single_inode(struct inode *inode, struct bdi_writeback *wb, | |
496 | struct writeback_control *wbc) | |
497 | { | |
498 | int ret = 0; | |
499 | ||
500 | spin_lock(&inode->i_lock); | |
501 | if (!atomic_read(&inode->i_count)) | |
502 | WARN_ON(!(inode->i_state & (I_WILL_FREE|I_FREEING))); | |
503 | else | |
504 | WARN_ON(inode->i_state & I_WILL_FREE); | |
505 | ||
506 | if (inode->i_state & I_SYNC) { | |
507 | if (wbc->sync_mode != WB_SYNC_ALL) | |
508 | goto out; | |
509 | /* | |
169ebd90 JK |
510 | * It's a data-integrity sync. We must wait. Since callers hold |
511 | * inode reference or inode has I_WILL_FREE set, it cannot go | |
512 | * away under us. | |
4f8ad655 | 513 | */ |
169ebd90 | 514 | __inode_wait_for_writeback(inode); |
4f8ad655 JK |
515 | } |
516 | WARN_ON(inode->i_state & I_SYNC); | |
517 | /* | |
518 | * Skip inode if it is clean. We don't want to mess with writeback | |
519 | * lists in this function since flusher thread may be doing for example | |
520 | * sync in parallel and if we move the inode, it could get skipped. So | |
521 | * here we make sure inode is on some writeback list and leave it there | |
522 | * unless we have completely cleaned the inode. | |
523 | */ | |
524 | if (!(inode->i_state & I_DIRTY)) | |
525 | goto out; | |
526 | inode->i_state |= I_SYNC; | |
527 | spin_unlock(&inode->i_lock); | |
528 | ||
529 | ret = __writeback_single_inode(inode, wb, wbc); | |
1da177e4 | 530 | |
f758eeab | 531 | spin_lock(&wb->list_lock); |
250df6ed | 532 | spin_lock(&inode->i_lock); |
4f8ad655 JK |
533 | /* |
534 | * If inode is clean, remove it from writeback lists. Otherwise don't | |
535 | * touch it. See comment above for explanation. | |
536 | */ | |
537 | if (!(inode->i_state & I_DIRTY)) | |
538 | list_del_init(&inode->i_wb_list); | |
539 | spin_unlock(&wb->list_lock); | |
1c0eeaf5 | 540 | inode_sync_complete(inode); |
4f8ad655 JK |
541 | out: |
542 | spin_unlock(&inode->i_lock); | |
1da177e4 LT |
543 | return ret; |
544 | } | |
545 | ||
1a12d8bd WF |
546 | static long writeback_chunk_size(struct backing_dev_info *bdi, |
547 | struct wb_writeback_work *work) | |
d46db3d5 WF |
548 | { |
549 | long pages; | |
550 | ||
551 | /* | |
552 | * WB_SYNC_ALL mode does livelock avoidance by syncing dirty | |
553 | * inodes/pages in one big loop. Setting wbc.nr_to_write=LONG_MAX | |
554 | * here avoids calling into writeback_inodes_wb() more than once. | |
555 | * | |
556 | * The intended call sequence for WB_SYNC_ALL writeback is: | |
557 | * | |
558 | * wb_writeback() | |
559 | * writeback_sb_inodes() <== called only once | |
560 | * write_cache_pages() <== called once for each inode | |
561 | * (quickly) tag currently dirty pages | |
562 | * (maybe slowly) sync all tagged pages | |
563 | */ | |
564 | if (work->sync_mode == WB_SYNC_ALL || work->tagged_writepages) | |
565 | pages = LONG_MAX; | |
1a12d8bd WF |
566 | else { |
567 | pages = min(bdi->avg_write_bandwidth / 2, | |
568 | global_dirty_limit / DIRTY_SCOPE); | |
569 | pages = min(pages, work->nr_pages); | |
570 | pages = round_down(pages + MIN_WRITEBACK_PAGES, | |
571 | MIN_WRITEBACK_PAGES); | |
572 | } | |
d46db3d5 WF |
573 | |
574 | return pages; | |
575 | } | |
576 | ||
f11c9c5c ES |
577 | /* |
578 | * Write a portion of b_io inodes which belong to @sb. | |
edadfb10 CH |
579 | * |
580 | * If @only_this_sb is true, then find and write all such | |
f11c9c5c ES |
581 | * inodes. Otherwise write only ones which go sequentially |
582 | * in reverse order. | |
edadfb10 | 583 | * |
d46db3d5 | 584 | * Return the number of pages and/or inodes written. |
f11c9c5c | 585 | */ |
d46db3d5 WF |
586 | static long writeback_sb_inodes(struct super_block *sb, |
587 | struct bdi_writeback *wb, | |
588 | struct wb_writeback_work *work) | |
1da177e4 | 589 | { |
d46db3d5 WF |
590 | struct writeback_control wbc = { |
591 | .sync_mode = work->sync_mode, | |
592 | .tagged_writepages = work->tagged_writepages, | |
593 | .for_kupdate = work->for_kupdate, | |
594 | .for_background = work->for_background, | |
595 | .range_cyclic = work->range_cyclic, | |
596 | .range_start = 0, | |
597 | .range_end = LLONG_MAX, | |
598 | }; | |
599 | unsigned long start_time = jiffies; | |
600 | long write_chunk; | |
601 | long wrote = 0; /* count both pages and inodes */ | |
602 | ||
03ba3782 | 603 | while (!list_empty(&wb->b_io)) { |
7ccf19a8 | 604 | struct inode *inode = wb_inode(wb->b_io.prev); |
edadfb10 CH |
605 | |
606 | if (inode->i_sb != sb) { | |
d46db3d5 | 607 | if (work->sb) { |
edadfb10 CH |
608 | /* |
609 | * We only want to write back data for this | |
610 | * superblock, move all inodes not belonging | |
611 | * to it back onto the dirty list. | |
612 | */ | |
f758eeab | 613 | redirty_tail(inode, wb); |
edadfb10 CH |
614 | continue; |
615 | } | |
616 | ||
617 | /* | |
618 | * The inode belongs to a different superblock. | |
619 | * Bounce back to the caller to unpin this and | |
620 | * pin the next superblock. | |
621 | */ | |
d46db3d5 | 622 | break; |
edadfb10 CH |
623 | } |
624 | ||
9843b76a | 625 | /* |
331cbdee WL |
626 | * Don't bother with new inodes or inodes being freed, first |
627 | * kind does not need periodic writeout yet, and for the latter | |
9843b76a CH |
628 | * kind writeout is handled by the freer. |
629 | */ | |
250df6ed | 630 | spin_lock(&inode->i_lock); |
9843b76a | 631 | if (inode->i_state & (I_NEW | I_FREEING | I_WILL_FREE)) { |
250df6ed | 632 | spin_unlock(&inode->i_lock); |
fcc5c222 | 633 | redirty_tail(inode, wb); |
7ef0d737 NP |
634 | continue; |
635 | } | |
cc1676d9 JK |
636 | if ((inode->i_state & I_SYNC) && wbc.sync_mode != WB_SYNC_ALL) { |
637 | /* | |
638 | * If this inode is locked for writeback and we are not | |
639 | * doing writeback-for-data-integrity, move it to | |
640 | * b_more_io so that writeback can proceed with the | |
641 | * other inodes on s_io. | |
642 | * | |
643 | * We'll have another go at writing back this inode | |
644 | * when we completed a full scan of b_io. | |
645 | */ | |
646 | spin_unlock(&inode->i_lock); | |
647 | requeue_io(inode, wb); | |
648 | trace_writeback_sb_inodes_requeue(inode); | |
649 | continue; | |
650 | } | |
f0d07b7f JK |
651 | spin_unlock(&wb->list_lock); |
652 | ||
4f8ad655 JK |
653 | /* |
654 | * We already requeued the inode if it had I_SYNC set and we | |
655 | * are doing WB_SYNC_NONE writeback. So this catches only the | |
656 | * WB_SYNC_ALL case. | |
657 | */ | |
169ebd90 JK |
658 | if (inode->i_state & I_SYNC) { |
659 | /* Wait for I_SYNC. This function drops i_lock... */ | |
660 | inode_sleep_on_writeback(inode); | |
661 | /* Inode may be gone, start again */ | |
ead188f9 | 662 | spin_lock(&wb->list_lock); |
169ebd90 JK |
663 | continue; |
664 | } | |
4f8ad655 JK |
665 | inode->i_state |= I_SYNC; |
666 | spin_unlock(&inode->i_lock); | |
169ebd90 | 667 | |
1a12d8bd | 668 | write_chunk = writeback_chunk_size(wb->bdi, work); |
d46db3d5 WF |
669 | wbc.nr_to_write = write_chunk; |
670 | wbc.pages_skipped = 0; | |
250df6ed | 671 | |
169ebd90 JK |
672 | /* |
673 | * We use I_SYNC to pin the inode in memory. While it is set | |
674 | * evict_inode() will wait so the inode cannot be freed. | |
675 | */ | |
4f8ad655 | 676 | __writeback_single_inode(inode, wb, &wbc); |
250df6ed | 677 | |
d46db3d5 WF |
678 | work->nr_pages -= write_chunk - wbc.nr_to_write; |
679 | wrote += write_chunk - wbc.nr_to_write; | |
4f8ad655 JK |
680 | spin_lock(&wb->list_lock); |
681 | spin_lock(&inode->i_lock); | |
d46db3d5 WF |
682 | if (!(inode->i_state & I_DIRTY)) |
683 | wrote++; | |
4f8ad655 JK |
684 | requeue_inode(inode, wb, &wbc); |
685 | inode_sync_complete(inode); | |
0f1b1fd8 | 686 | spin_unlock(&inode->i_lock); |
169ebd90 | 687 | cond_resched_lock(&wb->list_lock); |
d46db3d5 WF |
688 | /* |
689 | * bail out to wb_writeback() often enough to check | |
690 | * background threshold and other termination conditions. | |
691 | */ | |
692 | if (wrote) { | |
693 | if (time_is_before_jiffies(start_time + HZ / 10UL)) | |
694 | break; | |
695 | if (work->nr_pages <= 0) | |
696 | break; | |
8bc3be27 | 697 | } |
1da177e4 | 698 | } |
d46db3d5 | 699 | return wrote; |
f11c9c5c ES |
700 | } |
701 | ||
d46db3d5 WF |
702 | static long __writeback_inodes_wb(struct bdi_writeback *wb, |
703 | struct wb_writeback_work *work) | |
f11c9c5c | 704 | { |
d46db3d5 WF |
705 | unsigned long start_time = jiffies; |
706 | long wrote = 0; | |
38f21977 | 707 | |
f11c9c5c | 708 | while (!list_empty(&wb->b_io)) { |
7ccf19a8 | 709 | struct inode *inode = wb_inode(wb->b_io.prev); |
f11c9c5c | 710 | struct super_block *sb = inode->i_sb; |
9ecc2738 | 711 | |
12ad3ab6 | 712 | if (!grab_super_passive(sb)) { |
0e995816 WF |
713 | /* |
714 | * grab_super_passive() may fail consistently due to | |
715 | * s_umount being grabbed by someone else. Don't use | |
716 | * requeue_io() to avoid busy retrying the inode/sb. | |
717 | */ | |
718 | redirty_tail(inode, wb); | |
edadfb10 | 719 | continue; |
f11c9c5c | 720 | } |
d46db3d5 | 721 | wrote += writeback_sb_inodes(sb, wb, work); |
edadfb10 | 722 | drop_super(sb); |
f11c9c5c | 723 | |
d46db3d5 WF |
724 | /* refer to the same tests at the end of writeback_sb_inodes */ |
725 | if (wrote) { | |
726 | if (time_is_before_jiffies(start_time + HZ / 10UL)) | |
727 | break; | |
728 | if (work->nr_pages <= 0) | |
729 | break; | |
730 | } | |
f11c9c5c | 731 | } |
66f3b8e2 | 732 | /* Leave any unwritten inodes on b_io */ |
d46db3d5 | 733 | return wrote; |
66f3b8e2 JA |
734 | } |
735 | ||
0e175a18 CW |
736 | long writeback_inodes_wb(struct bdi_writeback *wb, long nr_pages, |
737 | enum wb_reason reason) | |
edadfb10 | 738 | { |
d46db3d5 WF |
739 | struct wb_writeback_work work = { |
740 | .nr_pages = nr_pages, | |
741 | .sync_mode = WB_SYNC_NONE, | |
742 | .range_cyclic = 1, | |
0e175a18 | 743 | .reason = reason, |
d46db3d5 | 744 | }; |
edadfb10 | 745 | |
f758eeab | 746 | spin_lock(&wb->list_lock); |
424b351f | 747 | if (list_empty(&wb->b_io)) |
ad4e38dd | 748 | queue_io(wb, &work); |
d46db3d5 | 749 | __writeback_inodes_wb(wb, &work); |
f758eeab | 750 | spin_unlock(&wb->list_lock); |
edadfb10 | 751 | |
d46db3d5 WF |
752 | return nr_pages - work.nr_pages; |
753 | } | |
03ba3782 | 754 | |
b00949aa | 755 | static bool over_bground_thresh(struct backing_dev_info *bdi) |
03ba3782 JA |
756 | { |
757 | unsigned long background_thresh, dirty_thresh; | |
758 | ||
16c4042f | 759 | global_dirty_limits(&background_thresh, &dirty_thresh); |
03ba3782 | 760 | |
b00949aa WF |
761 | if (global_page_state(NR_FILE_DIRTY) + |
762 | global_page_state(NR_UNSTABLE_NFS) > background_thresh) | |
763 | return true; | |
764 | ||
765 | if (bdi_stat(bdi, BDI_RECLAIMABLE) > | |
766 | bdi_dirty_limit(bdi, background_thresh)) | |
767 | return true; | |
768 | ||
769 | return false; | |
03ba3782 JA |
770 | } |
771 | ||
e98be2d5 WF |
772 | /* |
773 | * Called under wb->list_lock. If there are multiple wb per bdi, | |
774 | * only the flusher working on the first wb should do it. | |
775 | */ | |
776 | static void wb_update_bandwidth(struct bdi_writeback *wb, | |
777 | unsigned long start_time) | |
778 | { | |
af6a3113 | 779 | __bdi_update_bandwidth(wb->bdi, 0, 0, 0, 0, 0, start_time); |
e98be2d5 WF |
780 | } |
781 | ||
03ba3782 JA |
782 | /* |
783 | * Explicit flushing or periodic writeback of "old" data. | |
66f3b8e2 | 784 | * |
03ba3782 JA |
785 | * Define "old": the first time one of an inode's pages is dirtied, we mark the |
786 | * dirtying-time in the inode's address_space. So this periodic writeback code | |
787 | * just walks the superblock inode list, writing back any inodes which are | |
788 | * older than a specific point in time. | |
66f3b8e2 | 789 | * |
03ba3782 JA |
790 | * Try to run once per dirty_writeback_interval. But if a writeback event |
791 | * takes longer than a dirty_writeback_interval interval, then leave a | |
792 | * one-second gap. | |
66f3b8e2 | 793 | * |
03ba3782 JA |
794 | * older_than_this takes precedence over nr_to_write. So we'll only write back |
795 | * all dirty pages if they are all attached to "old" mappings. | |
66f3b8e2 | 796 | */ |
c4a77a6c | 797 | static long wb_writeback(struct bdi_writeback *wb, |
83ba7b07 | 798 | struct wb_writeback_work *work) |
66f3b8e2 | 799 | { |
e98be2d5 | 800 | unsigned long wb_start = jiffies; |
d46db3d5 | 801 | long nr_pages = work->nr_pages; |
03ba3782 | 802 | unsigned long oldest_jif; |
a5989bdc | 803 | struct inode *inode; |
d46db3d5 | 804 | long progress; |
66f3b8e2 | 805 | |
e185dda8 | 806 | oldest_jif = jiffies; |
d46db3d5 | 807 | work->older_than_this = &oldest_jif; |
38f21977 | 808 | |
e8dfc305 | 809 | spin_lock(&wb->list_lock); |
03ba3782 JA |
810 | for (;;) { |
811 | /* | |
d3ddec76 | 812 | * Stop writeback when nr_pages has been consumed |
03ba3782 | 813 | */ |
83ba7b07 | 814 | if (work->nr_pages <= 0) |
03ba3782 | 815 | break; |
66f3b8e2 | 816 | |
aa373cf5 JK |
817 | /* |
818 | * Background writeout and kupdate-style writeback may | |
819 | * run forever. Stop them if there is other work to do | |
820 | * so that e.g. sync can proceed. They'll be restarted | |
821 | * after the other works are all done. | |
822 | */ | |
823 | if ((work->for_background || work->for_kupdate) && | |
824 | !list_empty(&wb->bdi->work_list)) | |
825 | break; | |
826 | ||
38f21977 | 827 | /* |
d3ddec76 WF |
828 | * For background writeout, stop when we are below the |
829 | * background dirty threshold | |
38f21977 | 830 | */ |
b00949aa | 831 | if (work->for_background && !over_bground_thresh(wb->bdi)) |
03ba3782 | 832 | break; |
38f21977 | 833 | |
1bc36b64 JK |
834 | /* |
835 | * Kupdate and background works are special and we want to | |
836 | * include all inodes that need writing. Livelock avoidance is | |
837 | * handled by these works yielding to any other work so we are | |
838 | * safe. | |
839 | */ | |
ba9aa839 WF |
840 | if (work->for_kupdate) { |
841 | oldest_jif = jiffies - | |
842 | msecs_to_jiffies(dirty_expire_interval * 10); | |
1bc36b64 JK |
843 | } else if (work->for_background) |
844 | oldest_jif = jiffies; | |
028c2dd1 | 845 | |
d46db3d5 | 846 | trace_writeback_start(wb->bdi, work); |
e8dfc305 | 847 | if (list_empty(&wb->b_io)) |
ad4e38dd | 848 | queue_io(wb, work); |
83ba7b07 | 849 | if (work->sb) |
d46db3d5 | 850 | progress = writeback_sb_inodes(work->sb, wb, work); |
edadfb10 | 851 | else |
d46db3d5 WF |
852 | progress = __writeback_inodes_wb(wb, work); |
853 | trace_writeback_written(wb->bdi, work); | |
028c2dd1 | 854 | |
e98be2d5 | 855 | wb_update_bandwidth(wb, wb_start); |
03ba3782 JA |
856 | |
857 | /* | |
e6fb6da2 WF |
858 | * Did we write something? Try for more |
859 | * | |
860 | * Dirty inodes are moved to b_io for writeback in batches. | |
861 | * The completion of the current batch does not necessarily | |
862 | * mean the overall work is done. So we keep looping as long | |
863 | * as made some progress on cleaning pages or inodes. | |
03ba3782 | 864 | */ |
d46db3d5 | 865 | if (progress) |
71fd05a8 JA |
866 | continue; |
867 | /* | |
e6fb6da2 | 868 | * No more inodes for IO, bail |
71fd05a8 | 869 | */ |
b7a2441f | 870 | if (list_empty(&wb->b_more_io)) |
03ba3782 | 871 | break; |
71fd05a8 JA |
872 | /* |
873 | * Nothing written. Wait for some inode to | |
874 | * become available for writeback. Otherwise | |
875 | * we'll just busyloop. | |
876 | */ | |
71fd05a8 | 877 | if (!list_empty(&wb->b_more_io)) { |
d46db3d5 | 878 | trace_writeback_wait(wb->bdi, work); |
7ccf19a8 | 879 | inode = wb_inode(wb->b_more_io.prev); |
250df6ed | 880 | spin_lock(&inode->i_lock); |
f0d07b7f | 881 | spin_unlock(&wb->list_lock); |
169ebd90 JK |
882 | /* This function drops i_lock... */ |
883 | inode_sleep_on_writeback(inode); | |
f0d07b7f | 884 | spin_lock(&wb->list_lock); |
03ba3782 JA |
885 | } |
886 | } | |
e8dfc305 | 887 | spin_unlock(&wb->list_lock); |
03ba3782 | 888 | |
d46db3d5 | 889 | return nr_pages - work->nr_pages; |
03ba3782 JA |
890 | } |
891 | ||
892 | /* | |
83ba7b07 | 893 | * Return the next wb_writeback_work struct that hasn't been processed yet. |
03ba3782 | 894 | */ |
83ba7b07 | 895 | static struct wb_writeback_work * |
08852b6d | 896 | get_next_work_item(struct backing_dev_info *bdi) |
03ba3782 | 897 | { |
83ba7b07 | 898 | struct wb_writeback_work *work = NULL; |
03ba3782 | 899 | |
6467716a | 900 | spin_lock_bh(&bdi->wb_lock); |
83ba7b07 CH |
901 | if (!list_empty(&bdi->work_list)) { |
902 | work = list_entry(bdi->work_list.next, | |
903 | struct wb_writeback_work, list); | |
904 | list_del_init(&work->list); | |
03ba3782 | 905 | } |
6467716a | 906 | spin_unlock_bh(&bdi->wb_lock); |
83ba7b07 | 907 | return work; |
03ba3782 JA |
908 | } |
909 | ||
cdf01dd5 LT |
910 | /* |
911 | * Add in the number of potentially dirty inodes, because each inode | |
912 | * write can dirty pagecache in the underlying blockdev. | |
913 | */ | |
914 | static unsigned long get_nr_dirty_pages(void) | |
915 | { | |
916 | return global_page_state(NR_FILE_DIRTY) + | |
917 | global_page_state(NR_UNSTABLE_NFS) + | |
918 | get_nr_dirty_inodes(); | |
919 | } | |
920 | ||
6585027a JK |
921 | static long wb_check_background_flush(struct bdi_writeback *wb) |
922 | { | |
b00949aa | 923 | if (over_bground_thresh(wb->bdi)) { |
6585027a JK |
924 | |
925 | struct wb_writeback_work work = { | |
926 | .nr_pages = LONG_MAX, | |
927 | .sync_mode = WB_SYNC_NONE, | |
928 | .for_background = 1, | |
929 | .range_cyclic = 1, | |
0e175a18 | 930 | .reason = WB_REASON_BACKGROUND, |
6585027a JK |
931 | }; |
932 | ||
933 | return wb_writeback(wb, &work); | |
934 | } | |
935 | ||
936 | return 0; | |
937 | } | |
938 | ||
03ba3782 JA |
939 | static long wb_check_old_data_flush(struct bdi_writeback *wb) |
940 | { | |
941 | unsigned long expired; | |
942 | long nr_pages; | |
943 | ||
69b62d01 JA |
944 | /* |
945 | * When set to zero, disable periodic writeback | |
946 | */ | |
947 | if (!dirty_writeback_interval) | |
948 | return 0; | |
949 | ||
03ba3782 JA |
950 | expired = wb->last_old_flush + |
951 | msecs_to_jiffies(dirty_writeback_interval * 10); | |
952 | if (time_before(jiffies, expired)) | |
953 | return 0; | |
954 | ||
955 | wb->last_old_flush = jiffies; | |
cdf01dd5 | 956 | nr_pages = get_nr_dirty_pages(); |
03ba3782 | 957 | |
c4a77a6c | 958 | if (nr_pages) { |
83ba7b07 | 959 | struct wb_writeback_work work = { |
c4a77a6c JA |
960 | .nr_pages = nr_pages, |
961 | .sync_mode = WB_SYNC_NONE, | |
962 | .for_kupdate = 1, | |
963 | .range_cyclic = 1, | |
0e175a18 | 964 | .reason = WB_REASON_PERIODIC, |
c4a77a6c JA |
965 | }; |
966 | ||
83ba7b07 | 967 | return wb_writeback(wb, &work); |
c4a77a6c | 968 | } |
03ba3782 JA |
969 | |
970 | return 0; | |
971 | } | |
972 | ||
973 | /* | |
974 | * Retrieve work items and do the writeback they describe | |
975 | */ | |
976 | long wb_do_writeback(struct bdi_writeback *wb, int force_wait) | |
977 | { | |
978 | struct backing_dev_info *bdi = wb->bdi; | |
83ba7b07 | 979 | struct wb_writeback_work *work; |
c4a77a6c | 980 | long wrote = 0; |
03ba3782 | 981 | |
81d73a32 | 982 | set_bit(BDI_writeback_running, &wb->bdi->state); |
08852b6d | 983 | while ((work = get_next_work_item(bdi)) != NULL) { |
03ba3782 JA |
984 | /* |
985 | * Override sync mode, in case we must wait for completion | |
83ba7b07 | 986 | * because this thread is exiting now. |
03ba3782 JA |
987 | */ |
988 | if (force_wait) | |
83ba7b07 | 989 | work->sync_mode = WB_SYNC_ALL; |
03ba3782 | 990 | |
455b2864 DC |
991 | trace_writeback_exec(bdi, work); |
992 | ||
83ba7b07 | 993 | wrote += wb_writeback(wb, work); |
03ba3782 JA |
994 | |
995 | /* | |
83ba7b07 CH |
996 | * Notify the caller of completion if this is a synchronous |
997 | * work item, otherwise just free it. | |
03ba3782 | 998 | */ |
83ba7b07 CH |
999 | if (work->done) |
1000 | complete(work->done); | |
1001 | else | |
1002 | kfree(work); | |
03ba3782 JA |
1003 | } |
1004 | ||
1005 | /* | |
1006 | * Check for periodic writeback, kupdated() style | |
1007 | */ | |
1008 | wrote += wb_check_old_data_flush(wb); | |
6585027a | 1009 | wrote += wb_check_background_flush(wb); |
81d73a32 | 1010 | clear_bit(BDI_writeback_running, &wb->bdi->state); |
03ba3782 JA |
1011 | |
1012 | return wrote; | |
1013 | } | |
1014 | ||
1015 | /* | |
1016 | * Handle writeback of dirty data for the device backed by this bdi. Also | |
1017 | * wakes up periodically and does kupdated style flushing. | |
1018 | */ | |
08243900 | 1019 | int bdi_writeback_thread(void *data) |
03ba3782 | 1020 | { |
08243900 CH |
1021 | struct bdi_writeback *wb = data; |
1022 | struct backing_dev_info *bdi = wb->bdi; | |
03ba3782 JA |
1023 | long pages_written; |
1024 | ||
766f9164 | 1025 | current->flags |= PF_SWAPWRITE; |
08243900 | 1026 | set_freezable(); |
ecd58403 | 1027 | wb->last_active = jiffies; |
08243900 CH |
1028 | |
1029 | /* | |
1030 | * Our parent may run at a different priority, just set us to normal | |
1031 | */ | |
1032 | set_user_nice(current, 0); | |
1033 | ||
455b2864 DC |
1034 | trace_writeback_thread_start(bdi); |
1035 | ||
8a32c441 | 1036 | while (!kthread_freezable_should_stop(NULL)) { |
6467716a AB |
1037 | /* |
1038 | * Remove own delayed wake-up timer, since we are already awake | |
1039 | * and we'll take care of the preriodic write-back. | |
1040 | */ | |
1041 | del_timer(&wb->wakeup_timer); | |
1042 | ||
03ba3782 JA |
1043 | pages_written = wb_do_writeback(wb, 0); |
1044 | ||
455b2864 DC |
1045 | trace_writeback_pages_written(pages_written); |
1046 | ||
03ba3782 | 1047 | if (pages_written) |
ecd58403 | 1048 | wb->last_active = jiffies; |
03ba3782 | 1049 | |
297252c8 | 1050 | set_current_state(TASK_INTERRUPTIBLE); |
b76b4014 | 1051 | if (!list_empty(&bdi->work_list) || kthread_should_stop()) { |
f9eadbbd | 1052 | __set_current_state(TASK_RUNNING); |
297252c8 | 1053 | continue; |
03ba3782 JA |
1054 | } |
1055 | ||
253c34e9 | 1056 | if (wb_has_dirty_io(wb) && dirty_writeback_interval) |
fff5b85a | 1057 | schedule_timeout(msecs_to_jiffies(dirty_writeback_interval * 10)); |
253c34e9 AB |
1058 | else { |
1059 | /* | |
1060 | * We have nothing to do, so can go sleep without any | |
1061 | * timeout and save power. When a work is queued or | |
1062 | * something is made dirty - we will be woken up. | |
1063 | */ | |
297252c8 | 1064 | schedule(); |
f9eadbbd | 1065 | } |
03ba3782 JA |
1066 | } |
1067 | ||
fff5b85a | 1068 | /* Flush any work that raced with us exiting */ |
08243900 CH |
1069 | if (!list_empty(&bdi->work_list)) |
1070 | wb_do_writeback(wb, 1); | |
455b2864 DC |
1071 | |
1072 | trace_writeback_thread_stop(bdi); | |
03ba3782 JA |
1073 | return 0; |
1074 | } | |
1075 | ||
08243900 | 1076 | |
03ba3782 | 1077 | /* |
b8c2f347 CH |
1078 | * Start writeback of `nr_pages' pages. If `nr_pages' is zero, write back |
1079 | * the whole world. | |
03ba3782 | 1080 | */ |
0e175a18 | 1081 | void wakeup_flusher_threads(long nr_pages, enum wb_reason reason) |
03ba3782 | 1082 | { |
b8c2f347 | 1083 | struct backing_dev_info *bdi; |
03ba3782 | 1084 | |
83ba7b07 CH |
1085 | if (!nr_pages) { |
1086 | nr_pages = global_page_state(NR_FILE_DIRTY) + | |
b8c2f347 CH |
1087 | global_page_state(NR_UNSTABLE_NFS); |
1088 | } | |
03ba3782 | 1089 | |
b8c2f347 | 1090 | rcu_read_lock(); |
cfc4ba53 | 1091 | list_for_each_entry_rcu(bdi, &bdi_list, bdi_list) { |
03ba3782 JA |
1092 | if (!bdi_has_dirty_io(bdi)) |
1093 | continue; | |
0e175a18 | 1094 | __bdi_start_writeback(bdi, nr_pages, false, reason); |
03ba3782 | 1095 | } |
cfc4ba53 | 1096 | rcu_read_unlock(); |
1da177e4 LT |
1097 | } |
1098 | ||
03ba3782 JA |
1099 | static noinline void block_dump___mark_inode_dirty(struct inode *inode) |
1100 | { | |
1101 | if (inode->i_ino || strcmp(inode->i_sb->s_id, "bdev")) { | |
1102 | struct dentry *dentry; | |
1103 | const char *name = "?"; | |
1104 | ||
1105 | dentry = d_find_alias(inode); | |
1106 | if (dentry) { | |
1107 | spin_lock(&dentry->d_lock); | |
1108 | name = (const char *) dentry->d_name.name; | |
1109 | } | |
1110 | printk(KERN_DEBUG | |
1111 | "%s(%d): dirtied inode %lu (%s) on %s\n", | |
1112 | current->comm, task_pid_nr(current), inode->i_ino, | |
1113 | name, inode->i_sb->s_id); | |
1114 | if (dentry) { | |
1115 | spin_unlock(&dentry->d_lock); | |
1116 | dput(dentry); | |
1117 | } | |
1118 | } | |
1119 | } | |
1120 | ||
1121 | /** | |
1122 | * __mark_inode_dirty - internal function | |
1123 | * @inode: inode to mark | |
1124 | * @flags: what kind of dirty (i.e. I_DIRTY_SYNC) | |
1125 | * Mark an inode as dirty. Callers should use mark_inode_dirty or | |
1126 | * mark_inode_dirty_sync. | |
1da177e4 | 1127 | * |
03ba3782 JA |
1128 | * Put the inode on the super block's dirty list. |
1129 | * | |
1130 | * CAREFUL! We mark it dirty unconditionally, but move it onto the | |
1131 | * dirty list only if it is hashed or if it refers to a blockdev. | |
1132 | * If it was not hashed, it will never be added to the dirty list | |
1133 | * even if it is later hashed, as it will have been marked dirty already. | |
1134 | * | |
1135 | * In short, make sure you hash any inodes _before_ you start marking | |
1136 | * them dirty. | |
1da177e4 | 1137 | * |
03ba3782 JA |
1138 | * Note that for blockdevs, inode->dirtied_when represents the dirtying time of |
1139 | * the block-special inode (/dev/hda1) itself. And the ->dirtied_when field of | |
1140 | * the kernel-internal blockdev inode represents the dirtying time of the | |
1141 | * blockdev's pages. This is why for I_DIRTY_PAGES we always use | |
1142 | * page->mapping->host, so the page-dirtying time is recorded in the internal | |
1143 | * blockdev inode. | |
1da177e4 | 1144 | */ |
03ba3782 | 1145 | void __mark_inode_dirty(struct inode *inode, int flags) |
1da177e4 | 1146 | { |
03ba3782 | 1147 | struct super_block *sb = inode->i_sb; |
253c34e9 | 1148 | struct backing_dev_info *bdi = NULL; |
1da177e4 | 1149 | |
03ba3782 JA |
1150 | /* |
1151 | * Don't do this for I_DIRTY_PAGES - that doesn't actually | |
1152 | * dirty the inode itself | |
1153 | */ | |
1154 | if (flags & (I_DIRTY_SYNC | I_DIRTY_DATASYNC)) { | |
1155 | if (sb->s_op->dirty_inode) | |
aa385729 | 1156 | sb->s_op->dirty_inode(inode, flags); |
03ba3782 JA |
1157 | } |
1158 | ||
1159 | /* | |
1160 | * make sure that changes are seen by all cpus before we test i_state | |
1161 | * -- mikulas | |
1162 | */ | |
1163 | smp_mb(); | |
1164 | ||
1165 | /* avoid the locking if we can */ | |
1166 | if ((inode->i_state & flags) == flags) | |
1167 | return; | |
1168 | ||
1169 | if (unlikely(block_dump)) | |
1170 | block_dump___mark_inode_dirty(inode); | |
1171 | ||
250df6ed | 1172 | spin_lock(&inode->i_lock); |
03ba3782 JA |
1173 | if ((inode->i_state & flags) != flags) { |
1174 | const int was_dirty = inode->i_state & I_DIRTY; | |
1175 | ||
1176 | inode->i_state |= flags; | |
1177 | ||
1178 | /* | |
1179 | * If the inode is being synced, just update its dirty state. | |
1180 | * The unlocker will place the inode on the appropriate | |
1181 | * superblock list, based upon its state. | |
1182 | */ | |
1183 | if (inode->i_state & I_SYNC) | |
250df6ed | 1184 | goto out_unlock_inode; |
03ba3782 JA |
1185 | |
1186 | /* | |
1187 | * Only add valid (hashed) inodes to the superblock's | |
1188 | * dirty list. Add blockdev inodes as well. | |
1189 | */ | |
1190 | if (!S_ISBLK(inode->i_mode)) { | |
1d3382cb | 1191 | if (inode_unhashed(inode)) |
250df6ed | 1192 | goto out_unlock_inode; |
03ba3782 | 1193 | } |
a4ffdde6 | 1194 | if (inode->i_state & I_FREEING) |
250df6ed | 1195 | goto out_unlock_inode; |
03ba3782 JA |
1196 | |
1197 | /* | |
1198 | * If the inode was already on b_dirty/b_io/b_more_io, don't | |
1199 | * reposition it (that would break b_dirty time-ordering). | |
1200 | */ | |
1201 | if (!was_dirty) { | |
a66979ab | 1202 | bool wakeup_bdi = false; |
253c34e9 AB |
1203 | bdi = inode_to_bdi(inode); |
1204 | ||
1205 | if (bdi_cap_writeback_dirty(bdi)) { | |
1206 | WARN(!test_bit(BDI_registered, &bdi->state), | |
1207 | "bdi-%s not registered\n", bdi->name); | |
1208 | ||
1209 | /* | |
1210 | * If this is the first dirty inode for this | |
1211 | * bdi, we have to wake-up the corresponding | |
1212 | * bdi thread to make sure background | |
1213 | * write-back happens later. | |
1214 | */ | |
1215 | if (!wb_has_dirty_io(&bdi->wb)) | |
1216 | wakeup_bdi = true; | |
500b067c | 1217 | } |
03ba3782 | 1218 | |
a66979ab | 1219 | spin_unlock(&inode->i_lock); |
f758eeab | 1220 | spin_lock(&bdi->wb.list_lock); |
03ba3782 | 1221 | inode->dirtied_when = jiffies; |
7ccf19a8 | 1222 | list_move(&inode->i_wb_list, &bdi->wb.b_dirty); |
f758eeab | 1223 | spin_unlock(&bdi->wb.list_lock); |
a66979ab DC |
1224 | |
1225 | if (wakeup_bdi) | |
1226 | bdi_wakeup_thread_delayed(bdi); | |
1227 | return; | |
1da177e4 | 1228 | } |
1da177e4 | 1229 | } |
250df6ed DC |
1230 | out_unlock_inode: |
1231 | spin_unlock(&inode->i_lock); | |
253c34e9 | 1232 | |
03ba3782 JA |
1233 | } |
1234 | EXPORT_SYMBOL(__mark_inode_dirty); | |
1235 | ||
b6e51316 | 1236 | static void wait_sb_inodes(struct super_block *sb) |
03ba3782 JA |
1237 | { |
1238 | struct inode *inode, *old_inode = NULL; | |
1239 | ||
1240 | /* | |
1241 | * We need to be protected against the filesystem going from | |
1242 | * r/o to r/w or vice versa. | |
1243 | */ | |
b6e51316 | 1244 | WARN_ON(!rwsem_is_locked(&sb->s_umount)); |
03ba3782 | 1245 | |
55fa6091 | 1246 | spin_lock(&inode_sb_list_lock); |
03ba3782 JA |
1247 | |
1248 | /* | |
1249 | * Data integrity sync. Must wait for all pages under writeback, | |
1250 | * because there may have been pages dirtied before our sync | |
1251 | * call, but which had writeout started before we write it out. | |
1252 | * In which case, the inode may not be on the dirty list, but | |
1253 | * we still have to wait for that writeout. | |
1254 | */ | |
b6e51316 | 1255 | list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { |
250df6ed | 1256 | struct address_space *mapping = inode->i_mapping; |
03ba3782 | 1257 | |
250df6ed DC |
1258 | spin_lock(&inode->i_lock); |
1259 | if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) || | |
1260 | (mapping->nrpages == 0)) { | |
1261 | spin_unlock(&inode->i_lock); | |
03ba3782 | 1262 | continue; |
250df6ed | 1263 | } |
03ba3782 | 1264 | __iget(inode); |
250df6ed | 1265 | spin_unlock(&inode->i_lock); |
55fa6091 DC |
1266 | spin_unlock(&inode_sb_list_lock); |
1267 | ||
03ba3782 | 1268 | /* |
55fa6091 DC |
1269 | * We hold a reference to 'inode' so it couldn't have been |
1270 | * removed from s_inodes list while we dropped the | |
1271 | * inode_sb_list_lock. We cannot iput the inode now as we can | |
1272 | * be holding the last reference and we cannot iput it under | |
1273 | * inode_sb_list_lock. So we keep the reference and iput it | |
1274 | * later. | |
03ba3782 JA |
1275 | */ |
1276 | iput(old_inode); | |
1277 | old_inode = inode; | |
1278 | ||
1279 | filemap_fdatawait(mapping); | |
1280 | ||
1281 | cond_resched(); | |
1282 | ||
55fa6091 | 1283 | spin_lock(&inode_sb_list_lock); |
03ba3782 | 1284 | } |
55fa6091 | 1285 | spin_unlock(&inode_sb_list_lock); |
03ba3782 | 1286 | iput(old_inode); |
1da177e4 LT |
1287 | } |
1288 | ||
d8a8559c | 1289 | /** |
3259f8be | 1290 | * writeback_inodes_sb_nr - writeback dirty inodes from given super_block |
d8a8559c | 1291 | * @sb: the superblock |
3259f8be | 1292 | * @nr: the number of pages to write |
786228ab | 1293 | * @reason: reason why some writeback work initiated |
1da177e4 | 1294 | * |
d8a8559c JA |
1295 | * Start writeback on some inodes on this super_block. No guarantees are made |
1296 | * on how many (if any) will be written, and this function does not wait | |
3259f8be | 1297 | * for IO completion of submitted IO. |
1da177e4 | 1298 | */ |
0e175a18 CW |
1299 | void writeback_inodes_sb_nr(struct super_block *sb, |
1300 | unsigned long nr, | |
1301 | enum wb_reason reason) | |
1da177e4 | 1302 | { |
83ba7b07 CH |
1303 | DECLARE_COMPLETION_ONSTACK(done); |
1304 | struct wb_writeback_work work = { | |
6e6938b6 WF |
1305 | .sb = sb, |
1306 | .sync_mode = WB_SYNC_NONE, | |
1307 | .tagged_writepages = 1, | |
1308 | .done = &done, | |
1309 | .nr_pages = nr, | |
0e175a18 | 1310 | .reason = reason, |
3c4d7165 | 1311 | }; |
d8a8559c | 1312 | |
6eedc701 JK |
1313 | if (sb->s_bdi == &noop_backing_dev_info) |
1314 | return; | |
cf37e972 | 1315 | WARN_ON(!rwsem_is_locked(&sb->s_umount)); |
83ba7b07 CH |
1316 | bdi_queue_work(sb->s_bdi, &work); |
1317 | wait_for_completion(&done); | |
e913fc82 | 1318 | } |
3259f8be CM |
1319 | EXPORT_SYMBOL(writeback_inodes_sb_nr); |
1320 | ||
1321 | /** | |
1322 | * writeback_inodes_sb - writeback dirty inodes from given super_block | |
1323 | * @sb: the superblock | |
786228ab | 1324 | * @reason: reason why some writeback work was initiated |
3259f8be CM |
1325 | * |
1326 | * Start writeback on some inodes on this super_block. No guarantees are made | |
1327 | * on how many (if any) will be written, and this function does not wait | |
1328 | * for IO completion of submitted IO. | |
1329 | */ | |
0e175a18 | 1330 | void writeback_inodes_sb(struct super_block *sb, enum wb_reason reason) |
3259f8be | 1331 | { |
0e175a18 | 1332 | return writeback_inodes_sb_nr(sb, get_nr_dirty_pages(), reason); |
3259f8be | 1333 | } |
0e3c9a22 | 1334 | EXPORT_SYMBOL(writeback_inodes_sb); |
e913fc82 | 1335 | |
17bd55d0 ES |
1336 | /** |
1337 | * writeback_inodes_sb_if_idle - start writeback if none underway | |
1338 | * @sb: the superblock | |
786228ab | 1339 | * @reason: reason why some writeback work was initiated |
17bd55d0 ES |
1340 | * |
1341 | * Invoke writeback_inodes_sb if no writeback is currently underway. | |
1342 | * Returns 1 if writeback was started, 0 if not. | |
1343 | */ | |
0e175a18 | 1344 | int writeback_inodes_sb_if_idle(struct super_block *sb, enum wb_reason reason) |
17bd55d0 ES |
1345 | { |
1346 | if (!writeback_in_progress(sb->s_bdi)) { | |
cf37e972 | 1347 | down_read(&sb->s_umount); |
0e175a18 | 1348 | writeback_inodes_sb(sb, reason); |
cf37e972 | 1349 | up_read(&sb->s_umount); |
17bd55d0 ES |
1350 | return 1; |
1351 | } else | |
1352 | return 0; | |
1353 | } | |
1354 | EXPORT_SYMBOL(writeback_inodes_sb_if_idle); | |
1355 | ||
3259f8be | 1356 | /** |
c097b2ca | 1357 | * writeback_inodes_sb_nr_if_idle - start writeback if none underway |
3259f8be CM |
1358 | * @sb: the superblock |
1359 | * @nr: the number of pages to write | |
786228ab | 1360 | * @reason: reason why some writeback work was initiated |
3259f8be CM |
1361 | * |
1362 | * Invoke writeback_inodes_sb if no writeback is currently underway. | |
1363 | * Returns 1 if writeback was started, 0 if not. | |
1364 | */ | |
1365 | int writeback_inodes_sb_nr_if_idle(struct super_block *sb, | |
0e175a18 CW |
1366 | unsigned long nr, |
1367 | enum wb_reason reason) | |
3259f8be CM |
1368 | { |
1369 | if (!writeback_in_progress(sb->s_bdi)) { | |
1370 | down_read(&sb->s_umount); | |
0e175a18 | 1371 | writeback_inodes_sb_nr(sb, nr, reason); |
3259f8be CM |
1372 | up_read(&sb->s_umount); |
1373 | return 1; | |
1374 | } else | |
1375 | return 0; | |
1376 | } | |
1377 | EXPORT_SYMBOL(writeback_inodes_sb_nr_if_idle); | |
1378 | ||
d8a8559c JA |
1379 | /** |
1380 | * sync_inodes_sb - sync sb inode pages | |
1381 | * @sb: the superblock | |
1382 | * | |
1383 | * This function writes and waits on any dirty inode belonging to this | |
cb9ef8d5 | 1384 | * super_block. |
d8a8559c | 1385 | */ |
b6e51316 | 1386 | void sync_inodes_sb(struct super_block *sb) |
d8a8559c | 1387 | { |
83ba7b07 CH |
1388 | DECLARE_COMPLETION_ONSTACK(done); |
1389 | struct wb_writeback_work work = { | |
3c4d7165 CH |
1390 | .sb = sb, |
1391 | .sync_mode = WB_SYNC_ALL, | |
1392 | .nr_pages = LONG_MAX, | |
1393 | .range_cyclic = 0, | |
83ba7b07 | 1394 | .done = &done, |
0e175a18 | 1395 | .reason = WB_REASON_SYNC, |
3c4d7165 CH |
1396 | }; |
1397 | ||
6eedc701 JK |
1398 | /* Nothing to do? */ |
1399 | if (sb->s_bdi == &noop_backing_dev_info) | |
1400 | return; | |
cf37e972 CH |
1401 | WARN_ON(!rwsem_is_locked(&sb->s_umount)); |
1402 | ||
83ba7b07 CH |
1403 | bdi_queue_work(sb->s_bdi, &work); |
1404 | wait_for_completion(&done); | |
1405 | ||
b6e51316 | 1406 | wait_sb_inodes(sb); |
1da177e4 | 1407 | } |
d8a8559c | 1408 | EXPORT_SYMBOL(sync_inodes_sb); |
1da177e4 | 1409 | |
1da177e4 | 1410 | /** |
7f04c26d AA |
1411 | * write_inode_now - write an inode to disk |
1412 | * @inode: inode to write to disk | |
1413 | * @sync: whether the write should be synchronous or not | |
1414 | * | |
1415 | * This function commits an inode to disk immediately if it is dirty. This is | |
1416 | * primarily needed by knfsd. | |
1da177e4 | 1417 | * |
7f04c26d | 1418 | * The caller must either have a ref on the inode or must have set I_WILL_FREE. |
1da177e4 | 1419 | */ |
1da177e4 LT |
1420 | int write_inode_now(struct inode *inode, int sync) |
1421 | { | |
f758eeab | 1422 | struct bdi_writeback *wb = &inode_to_bdi(inode)->wb; |
1da177e4 LT |
1423 | struct writeback_control wbc = { |
1424 | .nr_to_write = LONG_MAX, | |
18914b18 | 1425 | .sync_mode = sync ? WB_SYNC_ALL : WB_SYNC_NONE, |
111ebb6e OH |
1426 | .range_start = 0, |
1427 | .range_end = LLONG_MAX, | |
1da177e4 LT |
1428 | }; |
1429 | ||
1430 | if (!mapping_cap_writeback_dirty(inode->i_mapping)) | |
49364ce2 | 1431 | wbc.nr_to_write = 0; |
1da177e4 LT |
1432 | |
1433 | might_sleep(); | |
4f8ad655 | 1434 | return writeback_single_inode(inode, wb, &wbc); |
1da177e4 LT |
1435 | } |
1436 | EXPORT_SYMBOL(write_inode_now); | |
1437 | ||
1438 | /** | |
1439 | * sync_inode - write an inode and its pages to disk. | |
1440 | * @inode: the inode to sync | |
1441 | * @wbc: controls the writeback mode | |
1442 | * | |
1443 | * sync_inode() will write an inode and its pages to disk. It will also | |
1444 | * correctly update the inode on its superblock's dirty inode lists and will | |
1445 | * update inode->i_state. | |
1446 | * | |
1447 | * The caller must have a ref on the inode. | |
1448 | */ | |
1449 | int sync_inode(struct inode *inode, struct writeback_control *wbc) | |
1450 | { | |
4f8ad655 | 1451 | return writeback_single_inode(inode, &inode_to_bdi(inode)->wb, wbc); |
1da177e4 LT |
1452 | } |
1453 | EXPORT_SYMBOL(sync_inode); | |
c3765016 CH |
1454 | |
1455 | /** | |
c691b9d9 | 1456 | * sync_inode_metadata - write an inode to disk |
c3765016 CH |
1457 | * @inode: the inode to sync |
1458 | * @wait: wait for I/O to complete. | |
1459 | * | |
c691b9d9 | 1460 | * Write an inode to disk and adjust its dirty state after completion. |
c3765016 CH |
1461 | * |
1462 | * Note: only writes the actual inode, no associated data or other metadata. | |
1463 | */ | |
1464 | int sync_inode_metadata(struct inode *inode, int wait) | |
1465 | { | |
1466 | struct writeback_control wbc = { | |
1467 | .sync_mode = wait ? WB_SYNC_ALL : WB_SYNC_NONE, | |
1468 | .nr_to_write = 0, /* metadata-only */ | |
1469 | }; | |
1470 | ||
1471 | return sync_inode(inode, &wbc); | |
1472 | } | |
1473 | EXPORT_SYMBOL(sync_inode_metadata); |