diff options
Diffstat (limited to 'fs')
-rw-r--r-- | fs/buffer.c | 2 | ||||
-rw-r--r-- | fs/fs-writeback.c | 999 | ||||
-rw-r--r-- | fs/super.c | 2 | ||||
-rw-r--r-- | fs/sync.c | 2 |
4 files changed, 713 insertions, 292 deletions
diff --git a/fs/buffer.c b/fs/buffer.c index 28f320fac4d4..90a98865b0cc 100644 --- a/fs/buffer.c +++ b/fs/buffer.c | |||
@@ -281,7 +281,7 @@ static void free_more_memory(void) | |||
281 | struct zone *zone; | 281 | struct zone *zone; |
282 | int nid; | 282 | int nid; |
283 | 283 | ||
284 | wakeup_pdflush(1024); | 284 | wakeup_flusher_threads(1024); |
285 | yield(); | 285 | yield(); |
286 | 286 | ||
287 | for_each_online_node(nid) { | 287 | for_each_online_node(nid) { |
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 45ad4bb700e6..7f6dae8aa47f 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c | |||
@@ -19,6 +19,8 @@ | |||
19 | #include <linux/sched.h> | 19 | #include <linux/sched.h> |
20 | #include <linux/fs.h> | 20 | #include <linux/fs.h> |
21 | #include <linux/mm.h> | 21 | #include <linux/mm.h> |
22 | #include <linux/kthread.h> | ||
23 | #include <linux/freezer.h> | ||
22 | #include <linux/writeback.h> | 24 | #include <linux/writeback.h> |
23 | #include <linux/blkdev.h> | 25 | #include <linux/blkdev.h> |
24 | #include <linux/backing-dev.h> | 26 | #include <linux/backing-dev.h> |
@@ -27,165 +29,208 @@ | |||
27 | 29 | ||
28 | #define inode_to_bdi(inode) ((inode)->i_mapping->backing_dev_info) | 30 | #define inode_to_bdi(inode) ((inode)->i_mapping->backing_dev_info) |
29 | 31 | ||
30 | /** | 32 | /* |
31 | * writeback_acquire - attempt to get exclusive writeback access to a device | 33 | * Work items for the bdi_writeback threads |
32 | * @bdi: the device's backing_dev_info structure | ||
33 | * | ||
34 | * It is a waste of resources to have more than one pdflush thread blocked on | ||
35 | * a single request queue. Exclusion at the request_queue level is obtained | ||
36 | * via a flag in the request_queue's backing_dev_info.state. | ||
37 | * | ||
38 | * Non-request_queue-backed address_spaces will share default_backing_dev_info, | ||
39 | * unless they implement their own. Which is somewhat inefficient, as this | ||
40 | * may prevent concurrent writeback against multiple devices. | ||
41 | */ | 34 | */ |
42 | static int writeback_acquire(struct backing_dev_info *bdi) | 35 | struct bdi_work { |
36 | struct list_head list; | ||
37 | struct list_head wait_list; | ||
38 | struct rcu_head rcu_head; | ||
39 | |||
40 | unsigned long seen; | ||
41 | atomic_t pending; | ||
42 | |||
43 | struct super_block *sb; | ||
44 | unsigned long nr_pages; | ||
45 | enum writeback_sync_modes sync_mode; | ||
46 | |||
47 | unsigned long state; | ||
48 | }; | ||
49 | |||
50 | enum { | ||
51 | WS_USED_B = 0, | ||
52 | WS_ONSTACK_B, | ||
53 | }; | ||
54 | |||
55 | #define WS_USED (1 << WS_USED_B) | ||
56 | #define WS_ONSTACK (1 << WS_ONSTACK_B) | ||
57 | |||
58 | static inline bool bdi_work_on_stack(struct bdi_work *work) | ||
59 | { | ||
60 | return test_bit(WS_ONSTACK_B, &work->state); | ||
61 | } | ||
62 | |||
63 | static inline void bdi_work_init(struct bdi_work *work, | ||
64 | struct writeback_control *wbc) | ||
65 | { | ||
66 | INIT_RCU_HEAD(&work->rcu_head); | ||
67 | work->sb = wbc->sb; | ||
68 | work->nr_pages = wbc->nr_to_write; | ||
69 | work->sync_mode = wbc->sync_mode; | ||
70 | work->state = WS_USED; | ||
71 | } | ||
72 | |||
73 | static inline void bdi_work_init_on_stack(struct bdi_work *work, | ||
74 | struct writeback_control *wbc) | ||
43 | { | 75 | { |
44 | return !test_and_set_bit(BDI_pdflush, &bdi->state); | 76 | bdi_work_init(work, wbc); |
77 | work->state |= WS_ONSTACK; | ||
45 | } | 78 | } |
46 | 79 | ||
47 | /** | 80 | /** |
48 | * writeback_in_progress - determine whether there is writeback in progress | 81 | * writeback_in_progress - determine whether there is writeback in progress |
49 | * @bdi: the device's backing_dev_info structure. | 82 | * @bdi: the device's backing_dev_info structure. |
50 | * | 83 | * |
51 | * Determine whether there is writeback in progress against a backing device. | 84 | * Determine whether there is writeback waiting to be handled against a |
85 | * backing device. | ||
52 | */ | 86 | */ |
53 | int writeback_in_progress(struct backing_dev_info *bdi) | 87 | int writeback_in_progress(struct backing_dev_info *bdi) |
54 | { | 88 | { |
55 | return test_bit(BDI_pdflush, &bdi->state); | 89 | return !list_empty(&bdi->work_list); |
56 | } | 90 | } |
57 | 91 | ||
58 | /** | 92 | static void bdi_work_clear(struct bdi_work *work) |
59 | * writeback_release - relinquish exclusive writeback access against a device. | ||
60 | * @bdi: the device's backing_dev_info structure | ||
61 | */ | ||
62 | static void writeback_release(struct backing_dev_info *bdi) | ||
63 | { | 93 | { |
64 | BUG_ON(!writeback_in_progress(bdi)); | 94 | clear_bit(WS_USED_B, &work->state); |
65 | clear_bit(BDI_pdflush, &bdi->state); | 95 | smp_mb__after_clear_bit(); |
96 | wake_up_bit(&work->state, WS_USED_B); | ||
66 | } | 97 | } |
67 | 98 | ||
68 | static noinline void block_dump___mark_inode_dirty(struct inode *inode) | 99 | static void bdi_work_free(struct rcu_head *head) |
69 | { | 100 | { |
70 | if (inode->i_ino || strcmp(inode->i_sb->s_id, "bdev")) { | 101 | struct bdi_work *work = container_of(head, struct bdi_work, rcu_head); |
71 | struct dentry *dentry; | ||
72 | const char *name = "?"; | ||
73 | 102 | ||
74 | dentry = d_find_alias(inode); | 103 | if (!bdi_work_on_stack(work)) |
75 | if (dentry) { | 104 | kfree(work); |
76 | spin_lock(&dentry->d_lock); | 105 | else |
77 | name = (const char *) dentry->d_name.name; | 106 | bdi_work_clear(work); |
78 | } | ||
79 | printk(KERN_DEBUG | ||
80 | "%s(%d): dirtied inode %lu (%s) on %s\n", | ||
81 | current->comm, task_pid_nr(current), inode->i_ino, | ||
82 | name, inode->i_sb->s_id); | ||
83 | if (dentry) { | ||
84 | spin_unlock(&dentry->d_lock); | ||
85 | dput(dentry); | ||
86 | } | ||
87 | } | ||
88 | } | 107 | } |
89 | 108 | ||
90 | /** | 109 | static void wb_work_complete(struct bdi_work *work) |
91 | * __mark_inode_dirty - internal function | ||
92 | * @inode: inode to mark | ||
93 | * @flags: what kind of dirty (i.e. I_DIRTY_SYNC) | ||
94 | * Mark an inode as dirty. Callers should use mark_inode_dirty or | ||
95 | * mark_inode_dirty_sync. | ||
96 | * | ||
97 | * Put the inode on the super block's dirty list. | ||
98 | * | ||
99 | * CAREFUL! We mark it dirty unconditionally, but move it onto the | ||
100 | * dirty list only if it is hashed or if it refers to a blockdev. | ||
101 | * If it was not hashed, it will never be added to the dirty list | ||
102 | * even if it is later hashed, as it will have been marked dirty already. | ||
103 | * | ||
104 | * In short, make sure you hash any inodes _before_ you start marking | ||
105 | * them dirty. | ||
106 | * | ||
107 | * This function *must* be atomic for the I_DIRTY_PAGES case - | ||
108 | * set_page_dirty() is called under spinlock in several places. | ||
109 | * | ||
110 | * Note that for blockdevs, inode->dirtied_when represents the dirtying time of | ||
111 | * the block-special inode (/dev/hda1) itself. And the ->dirtied_when field of | ||
112 | * the kernel-internal blockdev inode represents the dirtying time of the | ||
113 | * blockdev's pages. This is why for I_DIRTY_PAGES we always use | ||
114 | * page->mapping->host, so the page-dirtying time is recorded in the internal | ||
115 | * blockdev inode. | ||
116 | */ | ||
117 | void __mark_inode_dirty(struct inode *inode, int flags) | ||
118 | { | 110 | { |
119 | struct super_block *sb = inode->i_sb; | 111 | const enum writeback_sync_modes sync_mode = work->sync_mode; |
120 | 112 | ||
121 | /* | 113 | /* |
122 | * Don't do this for I_DIRTY_PAGES - that doesn't actually | 114 | * For allocated work, we can clear the done/seen bit right here. |
123 | * dirty the inode itself | 115 | * For on-stack work, we need to postpone both the clear and free |
116 | * to after the RCU grace period, since the stack could be invalidated | ||
117 | * as soon as bdi_work_clear() has done the wakeup. | ||
124 | */ | 118 | */ |
125 | if (flags & (I_DIRTY_SYNC | I_DIRTY_DATASYNC)) { | 119 | if (!bdi_work_on_stack(work)) |
126 | if (sb->s_op->dirty_inode) | 120 | bdi_work_clear(work); |
127 | sb->s_op->dirty_inode(inode); | 121 | if (sync_mode == WB_SYNC_NONE || bdi_work_on_stack(work)) |
128 | } | 122 | call_rcu(&work->rcu_head, bdi_work_free); |
123 | } | ||
129 | 124 | ||
125 | static void wb_clear_pending(struct bdi_writeback *wb, struct bdi_work *work) | ||
126 | { | ||
130 | /* | 127 | /* |
131 | * make sure that changes are seen by all cpus before we test i_state | 128 | * The caller has retrieved the work arguments from this work, |
132 | * -- mikulas | 129 | * drop our reference. If this is the last ref, delete and free it |
133 | */ | 130 | */ |
134 | smp_mb(); | 131 | if (atomic_dec_and_test(&work->pending)) { |
132 | struct backing_dev_info *bdi = wb->bdi; | ||
135 | 133 | ||
136 | /* avoid the locking if we can */ | 134 | spin_lock(&bdi->wb_lock); |
137 | if ((inode->i_state & flags) == flags) | 135 | list_del_rcu(&work->list); |
138 | return; | 136 | spin_unlock(&bdi->wb_lock); |
139 | |||
140 | if (unlikely(block_dump)) | ||
141 | block_dump___mark_inode_dirty(inode); | ||
142 | 137 | ||
143 | spin_lock(&inode_lock); | 138 | wb_work_complete(work); |
144 | if ((inode->i_state & flags) != flags) { | 139 | } |
145 | const int was_dirty = inode->i_state & I_DIRTY; | 140 | } |
146 | 141 | ||
147 | inode->i_state |= flags; | 142 | static void bdi_queue_work(struct backing_dev_info *bdi, struct bdi_work *work) |
143 | { | ||
144 | if (work) { | ||
145 | work->seen = bdi->wb_mask; | ||
146 | BUG_ON(!work->seen); | ||
147 | atomic_set(&work->pending, bdi->wb_cnt); | ||
148 | BUG_ON(!bdi->wb_cnt); | ||
148 | 149 | ||
149 | /* | 150 | /* |
150 | * If the inode is being synced, just update its dirty state. | 151 | * Make sure stores are seen before it appears on the list |
151 | * The unlocker will place the inode on the appropriate | ||
152 | * superblock list, based upon its state. | ||
153 | */ | 152 | */ |
154 | if (inode->i_state & I_SYNC) | 153 | smp_mb(); |
155 | goto out; | ||
156 | 154 | ||
157 | /* | 155 | spin_lock(&bdi->wb_lock); |
158 | * Only add valid (hashed) inodes to the superblock's | 156 | list_add_tail_rcu(&work->list, &bdi->work_list); |
159 | * dirty list. Add blockdev inodes as well. | 157 | spin_unlock(&bdi->wb_lock); |
160 | */ | 158 | } |
161 | if (!S_ISBLK(inode->i_mode)) { | 159 | |
162 | if (hlist_unhashed(&inode->i_hash)) | 160 | /* |
163 | goto out; | 161 | * If the default thread isn't there, make sure we add it. When |
164 | } | 162 | * it gets created and wakes up, we'll run this work. |
165 | if (inode->i_state & (I_FREEING|I_CLEAR)) | 163 | */ |
166 | goto out; | 164 | if (unlikely(list_empty_careful(&bdi->wb_list))) |
165 | wake_up_process(default_backing_dev_info.wb.task); | ||
166 | else { | ||
167 | struct bdi_writeback *wb = &bdi->wb; | ||
167 | 168 | ||
168 | /* | 169 | /* |
169 | * If the inode was already on b_dirty/b_io/b_more_io, don't | 170 | * If we failed allocating the bdi work item, wake up the wb |
170 | * reposition it (that would break b_dirty time-ordering). | 171 | * thread always. As a safety precaution, it'll flush out |
172 | * everything | ||
171 | */ | 173 | */ |
172 | if (!was_dirty) { | 174 | if (!wb_has_dirty_io(wb)) { |
173 | inode->dirtied_when = jiffies; | 175 | if (work) |
174 | list_move(&inode->i_list, | 176 | wb_clear_pending(wb, work); |
175 | &inode_to_bdi(inode)->b_dirty); | 177 | } else if (wb->task) |
176 | } | 178 | wake_up_process(wb->task); |
177 | } | 179 | } |
178 | out: | ||
179 | spin_unlock(&inode_lock); | ||
180 | } | 180 | } |
181 | 181 | ||
182 | EXPORT_SYMBOL(__mark_inode_dirty); | 182 | /* |
183 | * Used for on-stack allocated work items. The caller needs to wait until | ||
184 | * the wb threads have acked the work before it's safe to continue. | ||
185 | */ | ||
186 | static void bdi_wait_on_work_clear(struct bdi_work *work) | ||
187 | { | ||
188 | wait_on_bit(&work->state, WS_USED_B, bdi_sched_wait, | ||
189 | TASK_UNINTERRUPTIBLE); | ||
190 | } | ||
183 | 191 | ||
184 | static int write_inode(struct inode *inode, int sync) | 192 | static struct bdi_work *bdi_alloc_work(struct writeback_control *wbc) |
185 | { | 193 | { |
186 | if (inode->i_sb->s_op->write_inode && !is_bad_inode(inode)) | 194 | struct bdi_work *work; |
187 | return inode->i_sb->s_op->write_inode(inode, sync); | 195 | |
188 | return 0; | 196 | work = kmalloc(sizeof(*work), GFP_ATOMIC); |
197 | if (work) | ||
198 | bdi_work_init(work, wbc); | ||
199 | |||
200 | return work; | ||
201 | } | ||
202 | |||
203 | void bdi_start_writeback(struct writeback_control *wbc) | ||
204 | { | ||
205 | const bool must_wait = wbc->sync_mode == WB_SYNC_ALL; | ||
206 | struct bdi_work work_stack, *work = NULL; | ||
207 | |||
208 | if (!must_wait) | ||
209 | work = bdi_alloc_work(wbc); | ||
210 | |||
211 | if (!work) { | ||
212 | work = &work_stack; | ||
213 | bdi_work_init_on_stack(work, wbc); | ||
214 | } | ||
215 | |||
216 | bdi_queue_work(wbc->bdi, work); | ||
217 | |||
218 | /* | ||
219 | * If the sync mode is WB_SYNC_ALL, block waiting for the work to | ||
220 | * complete. If not, we only need to wait for the work to be started, | ||
221 | * if we allocated it on-stack. We use the same mechanism, if the | ||
222 | * wait bit is set in the bdi_work struct, then threads will not | ||
223 | * clear pending until after they are done. | ||
224 | * | ||
225 | * Note that work == &work_stack if must_wait is true, so we don't | ||
226 | * need to do call_rcu() here ever, since the completion path will | ||
227 | * have done that for us. | ||
228 | */ | ||
229 | if (must_wait || work == &work_stack) { | ||
230 | bdi_wait_on_work_clear(work); | ||
231 | if (work != &work_stack) | ||
232 | call_rcu(&work->rcu_head, bdi_work_free); | ||
233 | } | ||
189 | } | 234 | } |
190 | 235 | ||
191 | /* | 236 | /* |
@@ -199,16 +244,16 @@ static int write_inode(struct inode *inode, int sync) | |||
199 | */ | 244 | */ |
200 | static void redirty_tail(struct inode *inode) | 245 | static void redirty_tail(struct inode *inode) |
201 | { | 246 | { |
202 | struct backing_dev_info *bdi = inode_to_bdi(inode); | 247 | struct bdi_writeback *wb = &inode_to_bdi(inode)->wb; |
203 | 248 | ||
204 | if (!list_empty(&bdi->b_dirty)) { | 249 | if (!list_empty(&wb->b_dirty)) { |
205 | struct inode *tail; | 250 | struct inode *tail; |
206 | 251 | ||
207 | tail = list_entry(bdi->b_dirty.next, struct inode, i_list); | 252 | tail = list_entry(wb->b_dirty.next, struct inode, i_list); |
208 | if (time_before(inode->dirtied_when, tail->dirtied_when)) | 253 | if (time_before(inode->dirtied_when, tail->dirtied_when)) |
209 | inode->dirtied_when = jiffies; | 254 | inode->dirtied_when = jiffies; |
210 | } | 255 | } |
211 | list_move(&inode->i_list, &bdi->b_dirty); | 256 | list_move(&inode->i_list, &wb->b_dirty); |
212 | } | 257 | } |
213 | 258 | ||
214 | /* | 259 | /* |
@@ -216,7 +261,9 @@ static void redirty_tail(struct inode *inode) | |||
216 | */ | 261 | */ |
217 | static void requeue_io(struct inode *inode) | 262 | static void requeue_io(struct inode *inode) |
218 | { | 263 | { |
219 | list_move(&inode->i_list, &inode_to_bdi(inode)->b_more_io); | 264 | struct bdi_writeback *wb = &inode_to_bdi(inode)->wb; |
265 | |||
266 | list_move(&inode->i_list, &wb->b_more_io); | ||
220 | } | 267 | } |
221 | 268 | ||
222 | static void inode_sync_complete(struct inode *inode) | 269 | static void inode_sync_complete(struct inode *inode) |
@@ -263,52 +310,18 @@ static void move_expired_inodes(struct list_head *delaying_queue, | |||
263 | /* | 310 | /* |
264 | * Queue all expired dirty inodes for io, eldest first. | 311 | * Queue all expired dirty inodes for io, eldest first. |
265 | */ | 312 | */ |
266 | static void queue_io(struct backing_dev_info *bdi, | 313 | static void queue_io(struct bdi_writeback *wb, unsigned long *older_than_this) |
267 | unsigned long *older_than_this) | ||
268 | { | 314 | { |
269 | list_splice_init(&bdi->b_more_io, bdi->b_io.prev); | 315 | list_splice_init(&wb->b_more_io, wb->b_io.prev); |
270 | move_expired_inodes(&bdi->b_dirty, &bdi->b_io, older_than_this); | 316 | move_expired_inodes(&wb->b_dirty, &wb->b_io, older_than_this); |
271 | } | 317 | } |
272 | 318 | ||
273 | static int sb_on_inode_list(struct super_block *sb, struct list_head *list) | 319 | static int write_inode(struct inode *inode, int sync) |
274 | { | ||
275 | struct inode *inode; | ||
276 | int ret = 0; | ||
277 | |||
278 | spin_lock(&inode_lock); | ||
279 | list_for_each_entry(inode, list, i_list) { | ||
280 | if (inode->i_sb == sb) { | ||
281 | ret = 1; | ||
282 | break; | ||
283 | } | ||
284 | } | ||
285 | spin_unlock(&inode_lock); | ||
286 | return ret; | ||
287 | } | ||
288 | |||
289 | int sb_has_dirty_inodes(struct super_block *sb) | ||
290 | { | 320 | { |
291 | struct backing_dev_info *bdi; | 321 | if (inode->i_sb->s_op->write_inode && !is_bad_inode(inode)) |
292 | int ret = 0; | 322 | return inode->i_sb->s_op->write_inode(inode, sync); |
293 | 323 | return 0; | |
294 | /* | ||
295 | * This is REALLY expensive right now, but it'll go away | ||
296 | * when the bdi writeback is introduced | ||
297 | */ | ||
298 | mutex_lock(&bdi_lock); | ||
299 | list_for_each_entry(bdi, &bdi_list, bdi_list) { | ||
300 | if (sb_on_inode_list(sb, &bdi->b_dirty) || | ||
301 | sb_on_inode_list(sb, &bdi->b_io) || | ||
302 | sb_on_inode_list(sb, &bdi->b_more_io)) { | ||
303 | ret = 1; | ||
304 | break; | ||
305 | } | ||
306 | } | ||
307 | mutex_unlock(&bdi_lock); | ||
308 | |||
309 | return ret; | ||
310 | } | 324 | } |
311 | EXPORT_SYMBOL(sb_has_dirty_inodes); | ||
312 | 325 | ||
313 | /* | 326 | /* |
314 | * Wait for writeback on an inode to complete. | 327 | * Wait for writeback on an inode to complete. |
@@ -466,20 +479,71 @@ writeback_single_inode(struct inode *inode, struct writeback_control *wbc) | |||
466 | return ret; | 479 | return ret; |
467 | } | 480 | } |
468 | 481 | ||
469 | static void generic_sync_bdi_inodes(struct backing_dev_info *bdi, | 482 | /* |
470 | struct writeback_control *wbc, | 483 | * For WB_SYNC_NONE writeback, the caller does not have the sb pinned |
471 | struct super_block *sb) | 484 | * before calling writeback. So make sure that we do pin it, so it doesn't |
485 | * go away while we are writing inodes from it. | ||
486 | * | ||
487 | * Returns 0 if the super was successfully pinned (or pinning wasn't needed), | ||
488 | * 1 if we failed. | ||
489 | */ | ||
490 | static int pin_sb_for_writeback(struct writeback_control *wbc, | ||
491 | struct inode *inode) | ||
492 | { | ||
493 | struct super_block *sb = inode->i_sb; | ||
494 | |||
495 | /* | ||
496 | * Caller must already hold the ref for this | ||
497 | */ | ||
498 | if (wbc->sync_mode == WB_SYNC_ALL) { | ||
499 | WARN_ON(!rwsem_is_locked(&sb->s_umount)); | ||
500 | return 0; | ||
501 | } | ||
502 | |||
503 | spin_lock(&sb_lock); | ||
504 | sb->s_count++; | ||
505 | if (down_read_trylock(&sb->s_umount)) { | ||
506 | if (sb->s_root) { | ||
507 | spin_unlock(&sb_lock); | ||
508 | return 0; | ||
509 | } | ||
510 | /* | ||
511 | * umounted, drop rwsem again and fall through to failure | ||
512 | */ | ||
513 | up_read(&sb->s_umount); | ||
514 | } | ||
515 | |||
516 | sb->s_count--; | ||
517 | spin_unlock(&sb_lock); | ||
518 | return 1; | ||
519 | } | ||
520 | |||
521 | static void unpin_sb_for_writeback(struct writeback_control *wbc, | ||
522 | struct inode *inode) | ||
523 | { | ||
524 | struct super_block *sb = inode->i_sb; | ||
525 | |||
526 | if (wbc->sync_mode == WB_SYNC_ALL) | ||
527 | return; | ||
528 | |||
529 | up_read(&sb->s_umount); | ||
530 | put_super(sb); | ||
531 | } | ||
532 | |||
533 | static void writeback_inodes_wb(struct bdi_writeback *wb, | ||
534 | struct writeback_control *wbc) | ||
472 | { | 535 | { |
536 | struct super_block *sb = wbc->sb; | ||
473 | const int is_blkdev_sb = sb_is_blkdev_sb(sb); | 537 | const int is_blkdev_sb = sb_is_blkdev_sb(sb); |
474 | const unsigned long start = jiffies; /* livelock avoidance */ | 538 | const unsigned long start = jiffies; /* livelock avoidance */ |
475 | 539 | ||
476 | spin_lock(&inode_lock); | 540 | spin_lock(&inode_lock); |
477 | 541 | ||
478 | if (!wbc->for_kupdate || list_empty(&bdi->b_io)) | 542 | if (!wbc->for_kupdate || list_empty(&wb->b_io)) |
479 | queue_io(bdi, wbc->older_than_this); | 543 | queue_io(wb, wbc->older_than_this); |
480 | 544 | ||
481 | while (!list_empty(&bdi->b_io)) { | 545 | while (!list_empty(&wb->b_io)) { |
482 | struct inode *inode = list_entry(bdi->b_io.prev, | 546 | struct inode *inode = list_entry(wb->b_io.prev, |
483 | struct inode, i_list); | 547 | struct inode, i_list); |
484 | long pages_skipped; | 548 | long pages_skipped; |
485 | 549 | ||
@@ -491,7 +555,7 @@ static void generic_sync_bdi_inodes(struct backing_dev_info *bdi, | |||
491 | continue; | 555 | continue; |
492 | } | 556 | } |
493 | 557 | ||
494 | if (!bdi_cap_writeback_dirty(bdi)) { | 558 | if (!bdi_cap_writeback_dirty(wb->bdi)) { |
495 | redirty_tail(inode); | 559 | redirty_tail(inode); |
496 | if (is_blkdev_sb) { | 560 | if (is_blkdev_sb) { |
497 | /* | 561 | /* |
@@ -513,7 +577,7 @@ static void generic_sync_bdi_inodes(struct backing_dev_info *bdi, | |||
513 | continue; | 577 | continue; |
514 | } | 578 | } |
515 | 579 | ||
516 | if (wbc->nonblocking && bdi_write_congested(bdi)) { | 580 | if (wbc->nonblocking && bdi_write_congested(wb->bdi)) { |
517 | wbc->encountered_congestion = 1; | 581 | wbc->encountered_congestion = 1; |
518 | if (!is_blkdev_sb) | 582 | if (!is_blkdev_sb) |
519 | break; /* Skip a congested fs */ | 583 | break; /* Skip a congested fs */ |
@@ -521,13 +585,6 @@ static void generic_sync_bdi_inodes(struct backing_dev_info *bdi, | |||
521 | continue; /* Skip a congested blockdev */ | 585 | continue; /* Skip a congested blockdev */ |
522 | } | 586 | } |
523 | 587 | ||
524 | if (wbc->bdi && bdi != wbc->bdi) { | ||
525 | if (!is_blkdev_sb) | ||
526 | break; /* fs has the wrong queue */ | ||
527 | requeue_io(inode); | ||
528 | continue; /* blockdev has wrong queue */ | ||
529 | } | ||
530 | |||
531 | /* | 588 | /* |
532 | * Was this inode dirtied after sync_sb_inodes was called? | 589 | * Was this inode dirtied after sync_sb_inodes was called? |
533 | * This keeps sync from extra jobs and livelock. | 590 | * This keeps sync from extra jobs and livelock. |
@@ -535,16 +592,16 @@ static void generic_sync_bdi_inodes(struct backing_dev_info *bdi, | |||
535 | if (inode_dirtied_after(inode, start)) | 592 | if (inode_dirtied_after(inode, start)) |
536 | break; | 593 | break; |
537 | 594 | ||
538 | /* Is another pdflush already flushing this queue? */ | 595 | if (pin_sb_for_writeback(wbc, inode)) { |
539 | if (current_is_pdflush() && !writeback_acquire(bdi)) | 596 | requeue_io(inode); |
540 | break; | 597 | continue; |
598 | } | ||
541 | 599 | ||
542 | BUG_ON(inode->i_state & (I_FREEING | I_CLEAR)); | 600 | BUG_ON(inode->i_state & (I_FREEING | I_CLEAR)); |
543 | __iget(inode); | 601 | __iget(inode); |
544 | pages_skipped = wbc->pages_skipped; | 602 | pages_skipped = wbc->pages_skipped; |
545 | writeback_single_inode(inode, wbc); | 603 | writeback_single_inode(inode, wbc); |
546 | if (current_is_pdflush()) | 604 | unpin_sb_for_writeback(wbc, inode); |
547 | writeback_release(bdi); | ||
548 | if (wbc->pages_skipped != pages_skipped) { | 605 | if (wbc->pages_skipped != pages_skipped) { |
549 | /* | 606 | /* |
550 | * writeback is not making progress due to locked | 607 | * writeback is not making progress due to locked |
@@ -560,7 +617,7 @@ static void generic_sync_bdi_inodes(struct backing_dev_info *bdi, | |||
560 | wbc->more_io = 1; | 617 | wbc->more_io = 1; |
561 | break; | 618 | break; |
562 | } | 619 | } |
563 | if (!list_empty(&bdi->b_more_io)) | 620 | if (!list_empty(&wb->b_more_io)) |
564 | wbc->more_io = 1; | 621 | wbc->more_io = 1; |
565 | } | 622 | } |
566 | 623 | ||
@@ -568,139 +625,500 @@ static void generic_sync_bdi_inodes(struct backing_dev_info *bdi, | |||
568 | /* Leave any unwritten inodes on b_io */ | 625 | /* Leave any unwritten inodes on b_io */ |
569 | } | 626 | } |
570 | 627 | ||
628 | void writeback_inodes_wbc(struct writeback_control *wbc) | ||
629 | { | ||
630 | struct backing_dev_info *bdi = wbc->bdi; | ||
631 | |||
632 | writeback_inodes_wb(&bdi->wb, wbc); | ||
633 | } | ||
634 | |||
571 | /* | 635 | /* |
572 | * Write out a superblock's list of dirty inodes. A wait will be performed | 636 | * The maximum number of pages to writeout in a single bdi flush/kupdate |
573 | * upon no inodes, all inodes or the final one, depending upon sync_mode. | 637 | * operation. We do this so we don't hold I_SYNC against an inode for |
574 | * | 638 | * enormous amounts of time, which would block a userspace task which has |
575 | * If older_than_this is non-NULL, then only write out inodes which | 639 | * been forced to throttle against that inode. Also, the code reevaluates |
576 | * had their first dirtying at a time earlier than *older_than_this. | 640 | * the dirty each time it has written this many pages. |
577 | * | 641 | */ |
578 | * If we're a pdlfush thread, then implement pdflush collision avoidance | 642 | #define MAX_WRITEBACK_PAGES 1024 |
579 | * against the entire list. | 643 | |
644 | static inline bool over_bground_thresh(void) | ||
645 | { | ||
646 | unsigned long background_thresh, dirty_thresh; | ||
647 | |||
648 | get_dirty_limits(&background_thresh, &dirty_thresh, NULL, NULL); | ||
649 | |||
650 | return (global_page_state(NR_FILE_DIRTY) + | ||
651 | global_page_state(NR_UNSTABLE_NFS) >= background_thresh); | ||
652 | } | ||
653 | |||
654 | /* | ||
655 | * Explicit flushing or periodic writeback of "old" data. | ||
580 | * | 656 | * |
581 | * If `bdi' is non-zero then we're being asked to writeback a specific queue. | 657 | * Define "old": the first time one of an inode's pages is dirtied, we mark the |
582 | * This function assumes that the blockdev superblock's inodes are backed by | 658 | * dirtying-time in the inode's address_space. So this periodic writeback code |
583 | * a variety of queues, so all inodes are searched. For other superblocks, | 659 | * just walks the superblock inode list, writing back any inodes which are |
584 | * assume that all inodes are backed by the same queue. | 660 | * older than a specific point in time. |
585 | * | 661 | * |
586 | * FIXME: this linear search could get expensive with many fileystems. But | 662 | * Try to run once per dirty_writeback_interval. But if a writeback event |
587 | * how to fix? We need to go from an address_space to all inodes which share | 663 | * takes longer than a dirty_writeback_interval interval, then leave a |
588 | * a queue with that address_space. (Easy: have a global "dirty superblocks" | 664 | * one-second gap. |
589 | * list). | ||
590 | * | 665 | * |
591 | * The inodes to be written are parked on bdi->b_io. They are moved back onto | 666 | * older_than_this takes precedence over nr_to_write. So we'll only write back |
592 | * bdi->b_dirty as they are selected for writing. This way, none can be missed | 667 | * all dirty pages if they are all attached to "old" mappings. |
593 | * on the writer throttling path, and we get decent balancing between many | ||
594 | * throttled threads: we don't want them all piling up on inode_sync_wait. | ||
595 | */ | 668 | */ |
596 | static void generic_sync_sb_inodes(struct super_block *sb, | 669 | static long wb_writeback(struct bdi_writeback *wb, long nr_pages, |
597 | struct writeback_control *wbc) | 670 | struct super_block *sb, |
671 | enum writeback_sync_modes sync_mode, int for_kupdate) | ||
598 | { | 672 | { |
599 | struct backing_dev_info *bdi; | 673 | struct writeback_control wbc = { |
600 | 674 | .bdi = wb->bdi, | |
601 | if (!wbc->bdi) { | 675 | .sb = sb, |
602 | mutex_lock(&bdi_lock); | 676 | .sync_mode = sync_mode, |
603 | list_for_each_entry(bdi, &bdi_list, bdi_list) | 677 | .older_than_this = NULL, |
604 | generic_sync_bdi_inodes(bdi, wbc, sb); | 678 | .for_kupdate = for_kupdate, |
605 | mutex_unlock(&bdi_lock); | 679 | .range_cyclic = 1, |
606 | } else | 680 | }; |
607 | generic_sync_bdi_inodes(wbc->bdi, wbc, sb); | 681 | unsigned long oldest_jif; |
682 | long wrote = 0; | ||
608 | 683 | ||
609 | if (wbc->sync_mode == WB_SYNC_ALL) { | 684 | if (wbc.for_kupdate) { |
610 | struct inode *inode, *old_inode = NULL; | 685 | wbc.older_than_this = &oldest_jif; |
686 | oldest_jif = jiffies - | ||
687 | msecs_to_jiffies(dirty_expire_interval * 10); | ||
688 | } | ||
611 | 689 | ||
612 | spin_lock(&inode_lock); | 690 | for (;;) { |
691 | /* | ||
692 | * Don't flush anything for non-integrity writeback where | ||
693 | * no nr_pages was given | ||
694 | */ | ||
695 | if (!for_kupdate && nr_pages <= 0 && sync_mode == WB_SYNC_NONE) | ||
696 | break; | ||
613 | 697 | ||
614 | /* | 698 | /* |
615 | * Data integrity sync. Must wait for all pages under writeback, | 699 | * If no specific pages were given and this is just a |
616 | * because there may have been pages dirtied before our sync | 700 | * periodic background writeout and we are below the |
617 | * call, but which had writeout started before we write it out. | 701 | * background dirty threshold, don't do anything |
618 | * In which case, the inode may not be on the dirty list, but | ||
619 | * we still have to wait for that writeout. | ||
620 | */ | 702 | */ |
621 | list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { | 703 | if (for_kupdate && nr_pages <= 0 && !over_bground_thresh()) |
622 | struct address_space *mapping; | 704 | break; |
623 | 705 | ||
624 | if (inode->i_state & | 706 | wbc.more_io = 0; |
625 | (I_FREEING|I_CLEAR|I_WILL_FREE|I_NEW)) | 707 | wbc.encountered_congestion = 0; |
626 | continue; | 708 | wbc.nr_to_write = MAX_WRITEBACK_PAGES; |
627 | mapping = inode->i_mapping; | 709 | wbc.pages_skipped = 0; |
628 | if (mapping->nrpages == 0) | 710 | writeback_inodes_wb(wb, &wbc); |
711 | nr_pages -= MAX_WRITEBACK_PAGES - wbc.nr_to_write; | ||
712 | wrote += MAX_WRITEBACK_PAGES - wbc.nr_to_write; | ||
713 | |||
714 | /* | ||
715 | * If we ran out of stuff to write, bail unless more_io got set | ||
716 | */ | ||
717 | if (wbc.nr_to_write > 0 || wbc.pages_skipped > 0) { | ||
718 | if (wbc.more_io && !wbc.for_kupdate) | ||
629 | continue; | 719 | continue; |
630 | __iget(inode); | 720 | break; |
631 | spin_unlock(&inode_lock); | 721 | } |
722 | } | ||
723 | |||
724 | return wrote; | ||
725 | } | ||
726 | |||
727 | /* | ||
728 | * Return the next bdi_work struct that hasn't been processed by this | ||
729 | * wb thread yet | ||
730 | */ | ||
731 | static struct bdi_work *get_next_work_item(struct backing_dev_info *bdi, | ||
732 | struct bdi_writeback *wb) | ||
733 | { | ||
734 | struct bdi_work *work, *ret = NULL; | ||
735 | |||
736 | rcu_read_lock(); | ||
737 | |||
738 | list_for_each_entry_rcu(work, &bdi->work_list, list) { | ||
739 | if (!test_and_clear_bit(wb->nr, &work->seen)) | ||
740 | continue; | ||
741 | |||
742 | ret = work; | ||
743 | break; | ||
744 | } | ||
745 | |||
746 | rcu_read_unlock(); | ||
747 | return ret; | ||
748 | } | ||
749 | |||
750 | static long wb_check_old_data_flush(struct bdi_writeback *wb) | ||
751 | { | ||
752 | unsigned long expired; | ||
753 | long nr_pages; | ||
754 | |||
755 | expired = wb->last_old_flush + | ||
756 | msecs_to_jiffies(dirty_writeback_interval * 10); | ||
757 | if (time_before(jiffies, expired)) | ||
758 | return 0; | ||
759 | |||
760 | wb->last_old_flush = jiffies; | ||
761 | nr_pages = global_page_state(NR_FILE_DIRTY) + | ||
762 | global_page_state(NR_UNSTABLE_NFS) + | ||
763 | (inodes_stat.nr_inodes - inodes_stat.nr_unused); | ||
764 | |||
765 | if (nr_pages) | ||
766 | return wb_writeback(wb, nr_pages, NULL, WB_SYNC_NONE, 1); | ||
767 | |||
768 | return 0; | ||
769 | } | ||
770 | |||
771 | /* | ||
772 | * Retrieve work items and do the writeback they describe | ||
773 | */ | ||
774 | long wb_do_writeback(struct bdi_writeback *wb, int force_wait) | ||
775 | { | ||
776 | struct backing_dev_info *bdi = wb->bdi; | ||
777 | struct bdi_work *work; | ||
778 | long nr_pages, wrote = 0; | ||
779 | |||
780 | while ((work = get_next_work_item(bdi, wb)) != NULL) { | ||
781 | enum writeback_sync_modes sync_mode; | ||
782 | |||
783 | nr_pages = work->nr_pages; | ||
784 | |||
785 | /* | ||
786 | * Override sync mode, in case we must wait for completion | ||
787 | */ | ||
788 | if (force_wait) | ||
789 | work->sync_mode = sync_mode = WB_SYNC_ALL; | ||
790 | else | ||
791 | sync_mode = work->sync_mode; | ||
792 | |||
793 | /* | ||
794 | * If this isn't a data integrity operation, just notify | ||
795 | * that we have seen this work and we are now starting it. | ||
796 | */ | ||
797 | if (sync_mode == WB_SYNC_NONE) | ||
798 | wb_clear_pending(wb, work); | ||
799 | |||
800 | wrote += wb_writeback(wb, nr_pages, work->sb, sync_mode, 0); | ||
801 | |||
802 | /* | ||
803 | * This is a data integrity writeback, so only do the | ||
804 | * notification when we have completed the work. | ||
805 | */ | ||
806 | if (sync_mode == WB_SYNC_ALL) | ||
807 | wb_clear_pending(wb, work); | ||
808 | } | ||
809 | |||
810 | /* | ||
811 | * Check for periodic writeback, kupdated() style | ||
812 | */ | ||
813 | wrote += wb_check_old_data_flush(wb); | ||
814 | |||
815 | return wrote; | ||
816 | } | ||
817 | |||
818 | /* | ||
819 | * Handle writeback of dirty data for the device backed by this bdi. Also | ||
820 | * wakes up periodically and does kupdated style flushing. | ||
821 | */ | ||
822 | int bdi_writeback_task(struct bdi_writeback *wb) | ||
823 | { | ||
824 | unsigned long last_active = jiffies; | ||
825 | unsigned long wait_jiffies = -1UL; | ||
826 | long pages_written; | ||
827 | |||
828 | while (!kthread_should_stop()) { | ||
829 | pages_written = wb_do_writeback(wb, 0); | ||
830 | |||
831 | if (pages_written) | ||
832 | last_active = jiffies; | ||
833 | else if (wait_jiffies != -1UL) { | ||
834 | unsigned long max_idle; | ||
835 | |||
632 | /* | 836 | /* |
633 | * We hold a reference to 'inode' so it couldn't have | 837 | * Longest period of inactivity that we tolerate. If we |
634 | * been removed from s_inodes list while we dropped the | 838 | * see dirty data again later, the task will get |
635 | * inode_lock. We cannot iput the inode now as we can | 839 | * recreated automatically. |
636 | * be holding the last reference and we cannot iput it | ||
637 | * under inode_lock. So we keep the reference and iput | ||
638 | * it later. | ||
639 | */ | 840 | */ |
640 | iput(old_inode); | 841 | max_idle = max(5UL * 60 * HZ, wait_jiffies); |
641 | old_inode = inode; | 842 | if (time_after(jiffies, max_idle + last_active)) |
843 | break; | ||
844 | } | ||
845 | |||
846 | wait_jiffies = msecs_to_jiffies(dirty_writeback_interval * 10); | ||
847 | set_current_state(TASK_INTERRUPTIBLE); | ||
848 | schedule_timeout(wait_jiffies); | ||
849 | try_to_freeze(); | ||
850 | } | ||
851 | |||
852 | return 0; | ||
853 | } | ||
854 | |||
855 | /* | ||
856 | * Schedule writeback for all backing devices. Expensive! If this is a data | ||
857 | * integrity operation, writeback will be complete when this returns. If | ||
858 | * we are simply called for WB_SYNC_NONE, then writeback will merely be | ||
859 | * scheduled to run. | ||
860 | */ | ||
861 | static void bdi_writeback_all(struct writeback_control *wbc) | ||
862 | { | ||
863 | const bool must_wait = wbc->sync_mode == WB_SYNC_ALL; | ||
864 | struct backing_dev_info *bdi; | ||
865 | struct bdi_work *work; | ||
866 | LIST_HEAD(list); | ||
867 | |||
868 | restart: | ||
869 | spin_lock(&bdi_lock); | ||
870 | |||
871 | list_for_each_entry(bdi, &bdi_list, bdi_list) { | ||
872 | struct bdi_work *work; | ||
873 | |||
874 | if (!bdi_has_dirty_io(bdi)) | ||
875 | continue; | ||
642 | 876 | ||
643 | filemap_fdatawait(mapping); | 877 | /* |
878 | * If work allocation fails, do the writes inline. We drop | ||
879 | * the lock and restart the list writeout. This should be OK, | ||
880 | * since this happens rarely and because the writeout should | ||
881 | * eventually make more free memory available. | ||
882 | */ | ||
883 | work = bdi_alloc_work(wbc); | ||
884 | if (!work) { | ||
885 | struct writeback_control __wbc; | ||
644 | 886 | ||
645 | cond_resched(); | 887 | /* |
888 | * Not a data integrity writeout, just continue | ||
889 | */ | ||
890 | if (!must_wait) | ||
891 | continue; | ||
646 | 892 | ||
647 | spin_lock(&inode_lock); | 893 | spin_unlock(&bdi_lock); |
894 | __wbc = *wbc; | ||
895 | __wbc.bdi = bdi; | ||
896 | writeback_inodes_wbc(&__wbc); | ||
897 | goto restart; | ||
648 | } | 898 | } |
649 | spin_unlock(&inode_lock); | 899 | if (must_wait) |
650 | iput(old_inode); | 900 | list_add_tail(&work->wait_list, &list); |
901 | |||
902 | bdi_queue_work(bdi, work); | ||
903 | } | ||
904 | |||
905 | spin_unlock(&bdi_lock); | ||
906 | |||
907 | /* | ||
908 | * If this is for WB_SYNC_ALL, wait for pending work to complete | ||
909 | * before returning. | ||
910 | */ | ||
911 | while (!list_empty(&list)) { | ||
912 | work = list_entry(list.next, struct bdi_work, wait_list); | ||
913 | list_del(&work->wait_list); | ||
914 | bdi_wait_on_work_clear(work); | ||
915 | call_rcu(&work->rcu_head, bdi_work_free); | ||
651 | } | 916 | } |
652 | } | 917 | } |
653 | 918 | ||
654 | /* | 919 | /* |
655 | * Start writeback of dirty pagecache data against all unlocked inodes. | 920 | * Start writeback of `nr_pages' pages. If `nr_pages' is zero, write back |
921 | * the whole world. | ||
922 | */ | ||
923 | void wakeup_flusher_threads(long nr_pages) | ||
924 | { | ||
925 | struct writeback_control wbc = { | ||
926 | .sync_mode = WB_SYNC_NONE, | ||
927 | .older_than_this = NULL, | ||
928 | .range_cyclic = 1, | ||
929 | }; | ||
930 | |||
931 | if (nr_pages == 0) | ||
932 | nr_pages = global_page_state(NR_FILE_DIRTY) + | ||
933 | global_page_state(NR_UNSTABLE_NFS); | ||
934 | wbc.nr_to_write = nr_pages; | ||
935 | bdi_writeback_all(&wbc); | ||
936 | } | ||
937 | |||
938 | static noinline void block_dump___mark_inode_dirty(struct inode *inode) | ||
939 | { | ||
940 | if (inode->i_ino || strcmp(inode->i_sb->s_id, "bdev")) { | ||
941 | struct dentry *dentry; | ||
942 | const char *name = "?"; | ||
943 | |||
944 | dentry = d_find_alias(inode); | ||
945 | if (dentry) { | ||
946 | spin_lock(&dentry->d_lock); | ||
947 | name = (const char *) dentry->d_name.name; | ||
948 | } | ||
949 | printk(KERN_DEBUG | ||
950 | "%s(%d): dirtied inode %lu (%s) on %s\n", | ||
951 | current->comm, task_pid_nr(current), inode->i_ino, | ||
952 | name, inode->i_sb->s_id); | ||
953 | if (dentry) { | ||
954 | spin_unlock(&dentry->d_lock); | ||
955 | dput(dentry); | ||
956 | } | ||
957 | } | ||
958 | } | ||
959 | |||
960 | /** | ||
961 | * __mark_inode_dirty - internal function | ||
962 | * @inode: inode to mark | ||
963 | * @flags: what kind of dirty (i.e. I_DIRTY_SYNC) | ||
964 | * Mark an inode as dirty. Callers should use mark_inode_dirty or | ||
965 | * mark_inode_dirty_sync. | ||
656 | * | 966 | * |
657 | * Note: | 967 | * Put the inode on the super block's dirty list. |
658 | * We don't need to grab a reference to superblock here. If it has non-empty | 968 | * |
659 | * ->b_dirty it's hadn't been killed yet and kill_super() won't proceed | 969 | * CAREFUL! We mark it dirty unconditionally, but move it onto the |
660 | * past sync_inodes_sb() until the ->b_dirty/b_io/b_more_io lists are all | 970 | * dirty list only if it is hashed or if it refers to a blockdev. |
661 | * empty. Since __sync_single_inode() regains inode_lock before it finally moves | 971 | * If it was not hashed, it will never be added to the dirty list |
662 | * inode from superblock lists we are OK. | 972 | * even if it is later hashed, as it will have been marked dirty already. |
973 | * | ||
974 | * In short, make sure you hash any inodes _before_ you start marking | ||
975 | * them dirty. | ||
663 | * | 976 | * |
664 | * If `older_than_this' is non-zero then only flush inodes which have a | 977 | * This function *must* be atomic for the I_DIRTY_PAGES case - |
665 | * flushtime older than *older_than_this. | 978 | * set_page_dirty() is called under spinlock in several places. |
666 | * | 979 | * |
667 | * If `bdi' is non-zero then we will scan the first inode against each | 980 | * Note that for blockdevs, inode->dirtied_when represents the dirtying time of |
668 | * superblock until we find the matching ones. One group will be the dirty | 981 | * the block-special inode (/dev/hda1) itself. And the ->dirtied_when field of |
669 | * inodes against a filesystem. Then when we hit the dummy blockdev superblock, | 982 | * the kernel-internal blockdev inode represents the dirtying time of the |
670 | * sync_sb_inodes will seekout the blockdev which matches `bdi'. Maybe not | 983 | * blockdev's pages. This is why for I_DIRTY_PAGES we always use |
671 | * super-efficient but we're about to do a ton of I/O... | 984 | * page->mapping->host, so the page-dirtying time is recorded in the internal |
985 | * blockdev inode. | ||
672 | */ | 986 | */ |
673 | void | 987 | void __mark_inode_dirty(struct inode *inode, int flags) |
674 | writeback_inodes(struct writeback_control *wbc) | ||
675 | { | 988 | { |
676 | struct super_block *sb; | 989 | struct super_block *sb = inode->i_sb; |
677 | 990 | ||
678 | might_sleep(); | 991 | /* |
679 | spin_lock(&sb_lock); | 992 | * Don't do this for I_DIRTY_PAGES - that doesn't actually |
680 | restart: | 993 | * dirty the inode itself |
681 | list_for_each_entry_reverse(sb, &super_blocks, s_list) { | 994 | */ |
682 | if (sb_has_dirty_inodes(sb)) { | 995 | if (flags & (I_DIRTY_SYNC | I_DIRTY_DATASYNC)) { |
683 | /* we're making our own get_super here */ | 996 | if (sb->s_op->dirty_inode) |
684 | sb->s_count++; | 997 | sb->s_op->dirty_inode(inode); |
685 | spin_unlock(&sb_lock); | 998 | } |
686 | /* | 999 | |
687 | * If we can't get the readlock, there's no sense in | 1000 | /* |
688 | * waiting around, most of the time the FS is going to | 1001 | * make sure that changes are seen by all cpus before we test i_state |
689 | * be unmounted by the time it is released. | 1002 | * -- mikulas |
690 | */ | 1003 | */ |
691 | if (down_read_trylock(&sb->s_umount)) { | 1004 | smp_mb(); |
692 | if (sb->s_root) | 1005 | |
693 | generic_sync_sb_inodes(sb, wbc); | 1006 | /* avoid the locking if we can */ |
694 | up_read(&sb->s_umount); | 1007 | if ((inode->i_state & flags) == flags) |
695 | } | 1008 | return; |
696 | spin_lock(&sb_lock); | 1009 | |
697 | if (__put_super_and_need_restart(sb)) | 1010 | if (unlikely(block_dump)) |
698 | goto restart; | 1011 | block_dump___mark_inode_dirty(inode); |
1012 | |||
1013 | spin_lock(&inode_lock); | ||
1014 | if ((inode->i_state & flags) != flags) { | ||
1015 | const int was_dirty = inode->i_state & I_DIRTY; | ||
1016 | |||
1017 | inode->i_state |= flags; | ||
1018 | |||
1019 | /* | ||
1020 | * If the inode is being synced, just update its dirty state. | ||
1021 | * The unlocker will place the inode on the appropriate | ||
1022 | * superblock list, based upon its state. | ||
1023 | */ | ||
1024 | if (inode->i_state & I_SYNC) | ||
1025 | goto out; | ||
1026 | |||
1027 | /* | ||
1028 | * Only add valid (hashed) inodes to the superblock's | ||
1029 | * dirty list. Add blockdev inodes as well. | ||
1030 | */ | ||
1031 | if (!S_ISBLK(inode->i_mode)) { | ||
1032 | if (hlist_unhashed(&inode->i_hash)) | ||
1033 | goto out; | ||
1034 | } | ||
1035 | if (inode->i_state & (I_FREEING|I_CLEAR)) | ||
1036 | goto out; | ||
1037 | |||
1038 | /* | ||
1039 | * If the inode was already on b_dirty/b_io/b_more_io, don't | ||
1040 | * reposition it (that would break b_dirty time-ordering). | ||
1041 | */ | ||
1042 | if (!was_dirty) { | ||
1043 | struct bdi_writeback *wb = &inode_to_bdi(inode)->wb; | ||
1044 | |||
1045 | inode->dirtied_when = jiffies; | ||
1046 | list_move(&inode->i_list, &wb->b_dirty); | ||
699 | } | 1047 | } |
700 | if (wbc->nr_to_write <= 0) | ||
701 | break; | ||
702 | } | 1048 | } |
703 | spin_unlock(&sb_lock); | 1049 | out: |
1050 | spin_unlock(&inode_lock); | ||
1051 | } | ||
1052 | EXPORT_SYMBOL(__mark_inode_dirty); | ||
1053 | |||
1054 | /* | ||
1055 | * Write out a superblock's list of dirty inodes. A wait will be performed | ||
1056 | * upon no inodes, all inodes or the final one, depending upon sync_mode. | ||
1057 | * | ||
1058 | * If older_than_this is non-NULL, then only write out inodes which | ||
1059 | * had their first dirtying at a time earlier than *older_than_this. | ||
1060 | * | ||
1061 | * If we're a pdlfush thread, then implement pdflush collision avoidance | ||
1062 | * against the entire list. | ||
1063 | * | ||
1064 | * If `bdi' is non-zero then we're being asked to writeback a specific queue. | ||
1065 | * This function assumes that the blockdev superblock's inodes are backed by | ||
1066 | * a variety of queues, so all inodes are searched. For other superblocks, | ||
1067 | * assume that all inodes are backed by the same queue. | ||
1068 | * | ||
1069 | * The inodes to be written are parked on bdi->b_io. They are moved back onto | ||
1070 | * bdi->b_dirty as they are selected for writing. This way, none can be missed | ||
1071 | * on the writer throttling path, and we get decent balancing between many | ||
1072 | * throttled threads: we don't want them all piling up on inode_sync_wait. | ||
1073 | */ | ||
1074 | static void wait_sb_inodes(struct writeback_control *wbc) | ||
1075 | { | ||
1076 | struct inode *inode, *old_inode = NULL; | ||
1077 | |||
1078 | /* | ||
1079 | * We need to be protected against the filesystem going from | ||
1080 | * r/o to r/w or vice versa. | ||
1081 | */ | ||
1082 | WARN_ON(!rwsem_is_locked(&wbc->sb->s_umount)); | ||
1083 | |||
1084 | spin_lock(&inode_lock); | ||
1085 | |||
1086 | /* | ||
1087 | * Data integrity sync. Must wait for all pages under writeback, | ||
1088 | * because there may have been pages dirtied before our sync | ||
1089 | * call, but which had writeout started before we write it out. | ||
1090 | * In which case, the inode may not be on the dirty list, but | ||
1091 | * we still have to wait for that writeout. | ||
1092 | */ | ||
1093 | list_for_each_entry(inode, &wbc->sb->s_inodes, i_sb_list) { | ||
1094 | struct address_space *mapping; | ||
1095 | |||
1096 | if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE|I_NEW)) | ||
1097 | continue; | ||
1098 | mapping = inode->i_mapping; | ||
1099 | if (mapping->nrpages == 0) | ||
1100 | continue; | ||
1101 | __iget(inode); | ||
1102 | spin_unlock(&inode_lock); | ||
1103 | /* | ||
1104 | * We hold a reference to 'inode' so it couldn't have | ||
1105 | * been removed from s_inodes list while we dropped the | ||
1106 | * inode_lock. We cannot iput the inode now as we can | ||
1107 | * be holding the last reference and we cannot iput it | ||
1108 | * under inode_lock. So we keep the reference and iput | ||
1109 | * it later. | ||
1110 | */ | ||
1111 | iput(old_inode); | ||
1112 | old_inode = inode; | ||
1113 | |||
1114 | filemap_fdatawait(mapping); | ||
1115 | |||
1116 | cond_resched(); | ||
1117 | |||
1118 | spin_lock(&inode_lock); | ||
1119 | } | ||
1120 | spin_unlock(&inode_lock); | ||
1121 | iput(old_inode); | ||
704 | } | 1122 | } |
705 | 1123 | ||
706 | /** | 1124 | /** |
@@ -715,6 +1133,7 @@ restart: | |||
715 | long writeback_inodes_sb(struct super_block *sb) | 1133 | long writeback_inodes_sb(struct super_block *sb) |
716 | { | 1134 | { |
717 | struct writeback_control wbc = { | 1135 | struct writeback_control wbc = { |
1136 | .sb = sb, | ||
718 | .sync_mode = WB_SYNC_NONE, | 1137 | .sync_mode = WB_SYNC_NONE, |
719 | .range_start = 0, | 1138 | .range_start = 0, |
720 | .range_end = LLONG_MAX, | 1139 | .range_end = LLONG_MAX, |
@@ -727,7 +1146,7 @@ long writeback_inodes_sb(struct super_block *sb) | |||
727 | (inodes_stat.nr_inodes - inodes_stat.nr_unused); | 1146 | (inodes_stat.nr_inodes - inodes_stat.nr_unused); |
728 | 1147 | ||
729 | wbc.nr_to_write = nr_to_write; | 1148 | wbc.nr_to_write = nr_to_write; |
730 | generic_sync_sb_inodes(sb, &wbc); | 1149 | bdi_writeback_all(&wbc); |
731 | return nr_to_write - wbc.nr_to_write; | 1150 | return nr_to_write - wbc.nr_to_write; |
732 | } | 1151 | } |
733 | EXPORT_SYMBOL(writeback_inodes_sb); | 1152 | EXPORT_SYMBOL(writeback_inodes_sb); |
@@ -742,6 +1161,7 @@ EXPORT_SYMBOL(writeback_inodes_sb); | |||
742 | long sync_inodes_sb(struct super_block *sb) | 1161 | long sync_inodes_sb(struct super_block *sb) |
743 | { | 1162 | { |
744 | struct writeback_control wbc = { | 1163 | struct writeback_control wbc = { |
1164 | .sb = sb, | ||
745 | .sync_mode = WB_SYNC_ALL, | 1165 | .sync_mode = WB_SYNC_ALL, |
746 | .range_start = 0, | 1166 | .range_start = 0, |
747 | .range_end = LLONG_MAX, | 1167 | .range_end = LLONG_MAX, |
@@ -749,7 +1169,8 @@ long sync_inodes_sb(struct super_block *sb) | |||
749 | long nr_to_write = LONG_MAX; /* doesn't actually matter */ | 1169 | long nr_to_write = LONG_MAX; /* doesn't actually matter */ |
750 | 1170 | ||
751 | wbc.nr_to_write = nr_to_write; | 1171 | wbc.nr_to_write = nr_to_write; |
752 | generic_sync_sb_inodes(sb, &wbc); | 1172 | bdi_writeback_all(&wbc); |
1173 | wait_sb_inodes(&wbc); | ||
753 | return nr_to_write - wbc.nr_to_write; | 1174 | return nr_to_write - wbc.nr_to_write; |
754 | } | 1175 | } |
755 | EXPORT_SYMBOL(sync_inodes_sb); | 1176 | EXPORT_SYMBOL(sync_inodes_sb); |
diff --git a/fs/super.c b/fs/super.c index 0d22ce3be4aa..9cda337ddae2 100644 --- a/fs/super.c +++ b/fs/super.c | |||
@@ -168,7 +168,7 @@ int __put_super_and_need_restart(struct super_block *sb) | |||
168 | * Drops a temporary reference, frees superblock if there's no | 168 | * Drops a temporary reference, frees superblock if there's no |
169 | * references left. | 169 | * references left. |
170 | */ | 170 | */ |
171 | static void put_super(struct super_block *sb) | 171 | void put_super(struct super_block *sb) |
172 | { | 172 | { |
173 | spin_lock(&sb_lock); | 173 | spin_lock(&sb_lock); |
174 | __put_super(sb); | 174 | __put_super(sb); |
@@ -120,7 +120,7 @@ restart: | |||
120 | */ | 120 | */ |
121 | SYSCALL_DEFINE0(sync) | 121 | SYSCALL_DEFINE0(sync) |
122 | { | 122 | { |
123 | wakeup_pdflush(0); | 123 | wakeup_flusher_threads(0); |
124 | sync_filesystems(0); | 124 | sync_filesystems(0); |
125 | sync_filesystems(1); | 125 | sync_filesystems(1); |
126 | if (unlikely(laptop_mode)) | 126 | if (unlikely(laptop_mode)) |