Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | * |
Francois Cami | e1f8e87 | 2008-10-15 22:01:59 -0700 | [diff] [blame] | 11 | * 10Apr2002 Andrew Morton |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 12 | * Split out of fs/inode.c |
| 13 | * Additions for address_space-based writeback |
| 14 | */ |
| 15 | |
| 16 | #include <linux/kernel.h> |
Jens Axboe | f5ff842 | 2007-09-21 09:19:54 +0200 | [diff] [blame] | 17 | #include <linux/module.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 18 | #include <linux/spinlock.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 19 | #include <linux/slab.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 20 | #include <linux/sched.h> |
| 21 | #include <linux/fs.h> |
| 22 | #include <linux/mm.h> |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 23 | #include <linux/kthread.h> |
| 24 | #include <linux/freezer.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 25 | #include <linux/writeback.h> |
| 26 | #include <linux/blkdev.h> |
| 27 | #include <linux/backing-dev.h> |
| 28 | #include <linux/buffer_head.h> |
Dave Chinner | 455b286 | 2010-07-07 13:24:06 +1000 | [diff] [blame] | 29 | #include <linux/tracepoint.h> |
David Howells | 07f3f05 | 2006-09-30 20:52:18 +0200 | [diff] [blame] | 30 | #include "internal.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 31 | |
Jens Axboe | d0bceac | 2009-05-18 08:20:32 +0200 | [diff] [blame] | 32 | /* |
Jens Axboe | c4a77a6 | 2009-09-16 15:18:25 +0200 | [diff] [blame] | 33 | * Passed into wb_writeback(), essentially a subset of writeback_control |
| 34 | */ |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 35 | struct wb_writeback_work { |
Jens Axboe | c4a77a6 | 2009-09-16 15:18:25 +0200 | [diff] [blame] | 36 | long nr_pages; |
| 37 | struct super_block *sb; |
| 38 | enum writeback_sync_modes sync_mode; |
H Hartley Sweeten | 52957fe | 2010-04-01 20:36:30 -0500 | [diff] [blame] | 39 | unsigned int for_kupdate:1; |
| 40 | unsigned int range_cyclic:1; |
| 41 | unsigned int for_background:1; |
Jens Axboe | c4a77a6 | 2009-09-16 15:18:25 +0200 | [diff] [blame] | 42 | |
Jens Axboe | 8010c3b | 2009-09-15 20:04:57 +0200 | [diff] [blame] | 43 | struct list_head list; /* pending work list */ |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 44 | struct completion *done; /* set if the caller waits */ |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 45 | }; |
| 46 | |
Dave Chinner | 455b286 | 2010-07-07 13:24:06 +1000 | [diff] [blame] | 47 | /* |
| 48 | * Include the creation of the trace points after defining the |
| 49 | * wb_writeback_work structure so that the definition remains local to this |
| 50 | * file. |
| 51 | */ |
| 52 | #define CREATE_TRACE_POINTS |
| 53 | #include <trace/events/writeback.h> |
| 54 | |
Dave Chinner | 455b286 | 2010-07-07 13:24:06 +1000 | [diff] [blame] | 55 | /* |
| 56 | * We don't actually have pdflush, but this one is exported though /proc... |
| 57 | */ |
| 58 | int nr_pdflush_threads; |
| 59 | |
Adrian Bunk | f11b00f | 2008-04-29 00:58:56 -0700 | [diff] [blame] | 60 | /** |
| 61 | * writeback_in_progress - determine whether there is writeback in progress |
| 62 | * @bdi: the device's backing_dev_info structure. |
| 63 | * |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 64 | * Determine whether there is writeback waiting to be handled against a |
| 65 | * backing device. |
Adrian Bunk | f11b00f | 2008-04-29 00:58:56 -0700 | [diff] [blame] | 66 | */ |
| 67 | int writeback_in_progress(struct backing_dev_info *bdi) |
| 68 | { |
Jan Kara | 81d73a3 | 2010-08-11 14:17:44 -0700 | [diff] [blame] | 69 | return test_bit(BDI_writeback_running, &bdi->state); |
Adrian Bunk | f11b00f | 2008-04-29 00:58:56 -0700 | [diff] [blame] | 70 | } |
| 71 | |
Jan Kara | 692ebd1 | 2010-09-21 11:51:01 +0200 | [diff] [blame] | 72 | static inline struct backing_dev_info *inode_to_bdi(struct inode *inode) |
| 73 | { |
| 74 | struct super_block *sb = inode->i_sb; |
Jan Kara | 692ebd1 | 2010-09-21 11:51:01 +0200 | [diff] [blame] | 75 | |
Christoph Hellwig | aaead25 | 2010-10-04 14:25:33 +0200 | [diff] [blame] | 76 | if (strcmp(sb->s_type->name, "bdev") == 0) |
| 77 | return inode->i_mapping->backing_dev_info; |
| 78 | |
| 79 | return sb->s_bdi; |
Jan Kara | 692ebd1 | 2010-09-21 11:51:01 +0200 | [diff] [blame] | 80 | } |
| 81 | |
Nick Piggin | 7ccf19a | 2010-10-21 11:49:30 +1100 | [diff] [blame] | 82 | static inline struct inode *wb_inode(struct list_head *head) |
| 83 | { |
| 84 | return list_entry(head, struct inode, i_wb_list); |
| 85 | } |
| 86 | |
Jan Kara | 6585027 | 2011-01-13 15:45:44 -0800 | [diff] [blame] | 87 | /* Wakeup flusher thread or forker thread to fork it. Requires bdi->wb_lock. */ |
| 88 | static void bdi_wakeup_flusher(struct backing_dev_info *bdi) |
Nick Piggin | 4195f73 | 2009-05-28 09:01:15 +0200 | [diff] [blame] | 89 | { |
Artem Bityutskiy | fff5b85 | 2010-07-25 14:29:20 +0300 | [diff] [blame] | 90 | if (bdi->wb.task) { |
| 91 | wake_up_process(bdi->wb.task); |
| 92 | } else { |
| 93 | /* |
| 94 | * The bdi thread isn't there, wake up the forker thread which |
| 95 | * will create and run it. |
| 96 | */ |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 97 | wake_up_process(default_backing_dev_info.wb.task); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 98 | } |
Jan Kara | 6585027 | 2011-01-13 15:45:44 -0800 | [diff] [blame] | 99 | } |
| 100 | |
| 101 | static void bdi_queue_work(struct backing_dev_info *bdi, |
| 102 | struct wb_writeback_work *work) |
| 103 | { |
| 104 | trace_writeback_queue(bdi, work); |
| 105 | |
| 106 | spin_lock_bh(&bdi->wb_lock); |
| 107 | list_add_tail(&work->list, &bdi->work_list); |
| 108 | if (!bdi->wb.task) |
| 109 | trace_writeback_nothread(bdi, work); |
| 110 | bdi_wakeup_flusher(bdi); |
Artem Bityutskiy | 6467716 | 2010-07-25 14:29:22 +0300 | [diff] [blame] | 111 | spin_unlock_bh(&bdi->wb_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 112 | } |
| 113 | |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 114 | static void |
| 115 | __bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages, |
Jan Kara | 6585027 | 2011-01-13 15:45:44 -0800 | [diff] [blame] | 116 | bool range_cyclic) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 117 | { |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 118 | struct wb_writeback_work *work; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 119 | |
Jens Axboe | bcddc3f | 2009-09-13 20:07:36 +0200 | [diff] [blame] | 120 | /* |
| 121 | * This is WB_SYNC_NONE writeback, so if allocation fails just |
| 122 | * wakeup the thread for old dirty data writeback |
| 123 | */ |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 124 | work = kzalloc(sizeof(*work), GFP_ATOMIC); |
| 125 | if (!work) { |
Dave Chinner | 455b286 | 2010-07-07 13:24:06 +1000 | [diff] [blame] | 126 | if (bdi->wb.task) { |
| 127 | trace_writeback_nowork(bdi); |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 128 | wake_up_process(bdi->wb.task); |
Dave Chinner | 455b286 | 2010-07-07 13:24:06 +1000 | [diff] [blame] | 129 | } |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 130 | return; |
Jens Axboe | bcddc3f | 2009-09-13 20:07:36 +0200 | [diff] [blame] | 131 | } |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 132 | |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 133 | work->sync_mode = WB_SYNC_NONE; |
| 134 | work->nr_pages = nr_pages; |
| 135 | work->range_cyclic = range_cyclic; |
Christoph Hellwig | f0fad8a | 2009-09-11 09:47:56 +0200 | [diff] [blame] | 136 | |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 137 | bdi_queue_work(bdi, work); |
Jens Axboe | b6e5131 | 2009-09-16 15:13:54 +0200 | [diff] [blame] | 138 | } |
| 139 | |
| 140 | /** |
| 141 | * bdi_start_writeback - start writeback |
| 142 | * @bdi: the backing device to write from |
| 143 | * @nr_pages: the number of pages to write |
| 144 | * |
| 145 | * Description: |
| 146 | * This does WB_SYNC_NONE opportunistic writeback. The IO is only |
| 147 | * started when this function returns, we make no guarentees on |
Jens Axboe | 0e3c9a2 | 2010-06-01 11:08:43 +0200 | [diff] [blame] | 148 | * completion. Caller need not hold sb s_umount semaphore. |
Jens Axboe | b6e5131 | 2009-09-16 15:13:54 +0200 | [diff] [blame] | 149 | * |
| 150 | */ |
Christoph Hellwig | c544419 | 2010-06-08 18:15:15 +0200 | [diff] [blame] | 151 | void bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages) |
Jens Axboe | b6e5131 | 2009-09-16 15:13:54 +0200 | [diff] [blame] | 152 | { |
Jan Kara | 6585027 | 2011-01-13 15:45:44 -0800 | [diff] [blame] | 153 | __bdi_start_writeback(bdi, nr_pages, true); |
Christoph Hellwig | c544419 | 2010-06-08 18:15:15 +0200 | [diff] [blame] | 154 | } |
Wu Fengguang | d3ddec7 | 2009-09-23 20:33:40 +0800 | [diff] [blame] | 155 | |
Christoph Hellwig | c544419 | 2010-06-08 18:15:15 +0200 | [diff] [blame] | 156 | /** |
| 157 | * bdi_start_background_writeback - start background writeback |
| 158 | * @bdi: the backing device to write from |
| 159 | * |
| 160 | * Description: |
Jan Kara | 6585027 | 2011-01-13 15:45:44 -0800 | [diff] [blame] | 161 | * This makes sure WB_SYNC_NONE background writeback happens. When |
| 162 | * this function returns, it is only guaranteed that for given BDI |
| 163 | * some IO is happening if we are over background dirty threshold. |
| 164 | * Caller need not hold sb s_umount semaphore. |
Christoph Hellwig | c544419 | 2010-06-08 18:15:15 +0200 | [diff] [blame] | 165 | */ |
| 166 | void bdi_start_background_writeback(struct backing_dev_info *bdi) |
| 167 | { |
Jan Kara | 6585027 | 2011-01-13 15:45:44 -0800 | [diff] [blame] | 168 | /* |
| 169 | * We just wake up the flusher thread. It will perform background |
| 170 | * writeback as soon as there is no other work to do. |
| 171 | */ |
Wu Fengguang | 71927e8 | 2011-01-13 15:45:46 -0800 | [diff] [blame] | 172 | trace_writeback_wake_background(bdi); |
Jan Kara | 6585027 | 2011-01-13 15:45:44 -0800 | [diff] [blame] | 173 | spin_lock_bh(&bdi->wb_lock); |
| 174 | bdi_wakeup_flusher(bdi); |
| 175 | spin_unlock_bh(&bdi->wb_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 176 | } |
| 177 | |
| 178 | /* |
Andrew Morton | 6610a0b | 2007-10-16 23:30:32 -0700 | [diff] [blame] | 179 | * Redirty an inode: set its when-it-was dirtied timestamp and move it to the |
| 180 | * furthest end of its superblock's dirty-inode list. |
| 181 | * |
| 182 | * Before stamping the inode's ->dirtied_when, we check to see whether it is |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 183 | * already the most-recently-dirtied inode on the b_dirty list. If that is |
Andrew Morton | 6610a0b | 2007-10-16 23:30:32 -0700 | [diff] [blame] | 184 | * the case then the inode must have been redirtied while it was being written |
| 185 | * out and we don't reset its dirtied_when. |
| 186 | */ |
| 187 | static void redirty_tail(struct inode *inode) |
| 188 | { |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 189 | struct bdi_writeback *wb = &inode_to_bdi(inode)->wb; |
Andrew Morton | 6610a0b | 2007-10-16 23:30:32 -0700 | [diff] [blame] | 190 | |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 191 | if (!list_empty(&wb->b_dirty)) { |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 192 | struct inode *tail; |
Andrew Morton | 6610a0b | 2007-10-16 23:30:32 -0700 | [diff] [blame] | 193 | |
Nick Piggin | 7ccf19a | 2010-10-21 11:49:30 +1100 | [diff] [blame] | 194 | tail = wb_inode(wb->b_dirty.next); |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 195 | if (time_before(inode->dirtied_when, tail->dirtied_when)) |
Andrew Morton | 6610a0b | 2007-10-16 23:30:32 -0700 | [diff] [blame] | 196 | inode->dirtied_when = jiffies; |
| 197 | } |
Nick Piggin | 7ccf19a | 2010-10-21 11:49:30 +1100 | [diff] [blame] | 198 | list_move(&inode->i_wb_list, &wb->b_dirty); |
Andrew Morton | 6610a0b | 2007-10-16 23:30:32 -0700 | [diff] [blame] | 199 | } |
| 200 | |
| 201 | /* |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 202 | * requeue inode for re-scanning after bdi->b_io list is exhausted. |
Andrew Morton | c986d1e | 2007-10-16 23:30:34 -0700 | [diff] [blame] | 203 | */ |
Ken Chen | 0e0f4fc | 2007-10-16 23:30:38 -0700 | [diff] [blame] | 204 | static void requeue_io(struct inode *inode) |
Andrew Morton | c986d1e | 2007-10-16 23:30:34 -0700 | [diff] [blame] | 205 | { |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 206 | struct bdi_writeback *wb = &inode_to_bdi(inode)->wb; |
| 207 | |
Nick Piggin | 7ccf19a | 2010-10-21 11:49:30 +1100 | [diff] [blame] | 208 | list_move(&inode->i_wb_list, &wb->b_more_io); |
Andrew Morton | c986d1e | 2007-10-16 23:30:34 -0700 | [diff] [blame] | 209 | } |
| 210 | |
Joern Engel | 1c0eeaf | 2007-10-16 23:30:44 -0700 | [diff] [blame] | 211 | static void inode_sync_complete(struct inode *inode) |
| 212 | { |
| 213 | /* |
| 214 | * Prevent speculative execution through spin_unlock(&inode_lock); |
| 215 | */ |
| 216 | smp_mb(); |
| 217 | wake_up_bit(&inode->i_state, __I_SYNC); |
| 218 | } |
| 219 | |
Jeff Layton | d2caa3c5 | 2009-04-02 16:56:37 -0700 | [diff] [blame] | 220 | static bool inode_dirtied_after(struct inode *inode, unsigned long t) |
| 221 | { |
| 222 | bool ret = time_after(inode->dirtied_when, t); |
| 223 | #ifndef CONFIG_64BIT |
| 224 | /* |
| 225 | * For inodes being constantly redirtied, dirtied_when can get stuck. |
| 226 | * It _appears_ to be in the future, but is actually in distant past. |
| 227 | * This test is necessary to prevent such wrapped-around relative times |
Jens Axboe | 5b0830c | 2009-09-23 19:37:09 +0200 | [diff] [blame] | 228 | * from permanently stopping the whole bdi writeback. |
Jeff Layton | d2caa3c5 | 2009-04-02 16:56:37 -0700 | [diff] [blame] | 229 | */ |
| 230 | ret = ret && time_before_eq(inode->dirtied_when, jiffies); |
| 231 | #endif |
| 232 | return ret; |
| 233 | } |
| 234 | |
Andrew Morton | c986d1e | 2007-10-16 23:30:34 -0700 | [diff] [blame] | 235 | /* |
Fengguang Wu | 2c13657 | 2007-10-16 23:30:39 -0700 | [diff] [blame] | 236 | * Move expired dirty inodes from @delaying_queue to @dispatch_queue. |
| 237 | */ |
| 238 | static void move_expired_inodes(struct list_head *delaying_queue, |
| 239 | struct list_head *dispatch_queue, |
| 240 | unsigned long *older_than_this) |
| 241 | { |
Shaohua Li | 5c03449 | 2009-09-24 14:42:33 +0200 | [diff] [blame] | 242 | LIST_HEAD(tmp); |
| 243 | struct list_head *pos, *node; |
Jens Axboe | cf13730 | 2009-09-24 15:12:57 +0200 | [diff] [blame] | 244 | struct super_block *sb = NULL; |
Shaohua Li | 5c03449 | 2009-09-24 14:42:33 +0200 | [diff] [blame] | 245 | struct inode *inode; |
Jens Axboe | cf13730 | 2009-09-24 15:12:57 +0200 | [diff] [blame] | 246 | int do_sb_sort = 0; |
Shaohua Li | 5c03449 | 2009-09-24 14:42:33 +0200 | [diff] [blame] | 247 | |
Fengguang Wu | 2c13657 | 2007-10-16 23:30:39 -0700 | [diff] [blame] | 248 | while (!list_empty(delaying_queue)) { |
Nick Piggin | 7ccf19a | 2010-10-21 11:49:30 +1100 | [diff] [blame] | 249 | inode = wb_inode(delaying_queue->prev); |
Fengguang Wu | 2c13657 | 2007-10-16 23:30:39 -0700 | [diff] [blame] | 250 | if (older_than_this && |
Jeff Layton | d2caa3c5 | 2009-04-02 16:56:37 -0700 | [diff] [blame] | 251 | inode_dirtied_after(inode, *older_than_this)) |
Fengguang Wu | 2c13657 | 2007-10-16 23:30:39 -0700 | [diff] [blame] | 252 | break; |
Jens Axboe | cf13730 | 2009-09-24 15:12:57 +0200 | [diff] [blame] | 253 | if (sb && sb != inode->i_sb) |
| 254 | do_sb_sort = 1; |
| 255 | sb = inode->i_sb; |
Nick Piggin | 7ccf19a | 2010-10-21 11:49:30 +1100 | [diff] [blame] | 256 | list_move(&inode->i_wb_list, &tmp); |
Shaohua Li | 5c03449 | 2009-09-24 14:42:33 +0200 | [diff] [blame] | 257 | } |
| 258 | |
Jens Axboe | cf13730 | 2009-09-24 15:12:57 +0200 | [diff] [blame] | 259 | /* just one sb in list, splice to dispatch_queue and we're done */ |
| 260 | if (!do_sb_sort) { |
| 261 | list_splice(&tmp, dispatch_queue); |
| 262 | return; |
| 263 | } |
| 264 | |
Shaohua Li | 5c03449 | 2009-09-24 14:42:33 +0200 | [diff] [blame] | 265 | /* Move inodes from one superblock together */ |
| 266 | while (!list_empty(&tmp)) { |
Nick Piggin | 7ccf19a | 2010-10-21 11:49:30 +1100 | [diff] [blame] | 267 | sb = wb_inode(tmp.prev)->i_sb; |
Shaohua Li | 5c03449 | 2009-09-24 14:42:33 +0200 | [diff] [blame] | 268 | list_for_each_prev_safe(pos, node, &tmp) { |
Nick Piggin | 7ccf19a | 2010-10-21 11:49:30 +1100 | [diff] [blame] | 269 | inode = wb_inode(pos); |
Shaohua Li | 5c03449 | 2009-09-24 14:42:33 +0200 | [diff] [blame] | 270 | if (inode->i_sb == sb) |
Nick Piggin | 7ccf19a | 2010-10-21 11:49:30 +1100 | [diff] [blame] | 271 | list_move(&inode->i_wb_list, dispatch_queue); |
Shaohua Li | 5c03449 | 2009-09-24 14:42:33 +0200 | [diff] [blame] | 272 | } |
Fengguang Wu | 2c13657 | 2007-10-16 23:30:39 -0700 | [diff] [blame] | 273 | } |
| 274 | } |
| 275 | |
| 276 | /* |
| 277 | * Queue all expired dirty inodes for io, eldest first. |
Wu Fengguang | 4ea879b | 2010-08-11 14:17:42 -0700 | [diff] [blame] | 278 | * Before |
| 279 | * newly dirtied b_dirty b_io b_more_io |
| 280 | * =============> gf edc BA |
| 281 | * After |
| 282 | * newly dirtied b_dirty b_io b_more_io |
| 283 | * =============> g fBAedc |
| 284 | * | |
| 285 | * +--> dequeue for IO |
Fengguang Wu | 2c13657 | 2007-10-16 23:30:39 -0700 | [diff] [blame] | 286 | */ |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 287 | static void queue_io(struct bdi_writeback *wb, unsigned long *older_than_this) |
Fengguang Wu | 2c13657 | 2007-10-16 23:30:39 -0700 | [diff] [blame] | 288 | { |
Wu Fengguang | 4ea879b | 2010-08-11 14:17:42 -0700 | [diff] [blame] | 289 | list_splice_init(&wb->b_more_io, &wb->b_io); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 290 | move_expired_inodes(&wb->b_dirty, &wb->b_io, older_than_this); |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 291 | } |
| 292 | |
Christoph Hellwig | a9185b4 | 2010-03-05 09:21:37 +0100 | [diff] [blame] | 293 | static int write_inode(struct inode *inode, struct writeback_control *wbc) |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 294 | { |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 295 | if (inode->i_sb->s_op->write_inode && !is_bad_inode(inode)) |
Christoph Hellwig | a9185b4 | 2010-03-05 09:21:37 +0100 | [diff] [blame] | 296 | return inode->i_sb->s_op->write_inode(inode, wbc); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 297 | return 0; |
Fengguang Wu | 2c13657 | 2007-10-16 23:30:39 -0700 | [diff] [blame] | 298 | } |
| 299 | |
| 300 | /* |
Christoph Hellwig | 01c0319 | 2009-06-08 13:35:40 +0200 | [diff] [blame] | 301 | * Wait for writeback on an inode to complete. |
| 302 | */ |
| 303 | static void inode_wait_for_writeback(struct inode *inode) |
| 304 | { |
| 305 | DEFINE_WAIT_BIT(wq, &inode->i_state, __I_SYNC); |
| 306 | wait_queue_head_t *wqh; |
| 307 | |
| 308 | wqh = bit_waitqueue(&inode->i_state, __I_SYNC); |
Richard Kennedy | 58a9d3d8 | 2010-05-24 14:32:38 -0700 | [diff] [blame] | 309 | while (inode->i_state & I_SYNC) { |
Christoph Hellwig | 01c0319 | 2009-06-08 13:35:40 +0200 | [diff] [blame] | 310 | spin_unlock(&inode_lock); |
| 311 | __wait_on_bit(wqh, &wq, inode_wait, TASK_UNINTERRUPTIBLE); |
| 312 | spin_lock(&inode_lock); |
Richard Kennedy | 58a9d3d8 | 2010-05-24 14:32:38 -0700 | [diff] [blame] | 313 | } |
Christoph Hellwig | 01c0319 | 2009-06-08 13:35:40 +0200 | [diff] [blame] | 314 | } |
| 315 | |
| 316 | /* |
| 317 | * Write out an inode's dirty pages. Called under inode_lock. Either the |
| 318 | * caller has ref on the inode (either via __iget or via syscall against an fd) |
| 319 | * or the inode has I_WILL_FREE set (via generic_forget_inode) |
| 320 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 321 | * If `wait' is set, wait on the writeout. |
| 322 | * |
| 323 | * The whole writeout design is quite complex and fragile. We want to avoid |
| 324 | * starvation of particular inodes when others are being redirtied, prevent |
| 325 | * livelocks, etc. |
| 326 | * |
| 327 | * Called under inode_lock. |
| 328 | */ |
| 329 | static int |
Christoph Hellwig | 01c0319 | 2009-06-08 13:35:40 +0200 | [diff] [blame] | 330 | writeback_single_inode(struct inode *inode, struct writeback_control *wbc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 331 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 332 | struct address_space *mapping = inode->i_mapping; |
Christoph Hellwig | 01c0319 | 2009-06-08 13:35:40 +0200 | [diff] [blame] | 333 | unsigned dirty; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 334 | int ret; |
| 335 | |
Christoph Hellwig | 01c0319 | 2009-06-08 13:35:40 +0200 | [diff] [blame] | 336 | if (!atomic_read(&inode->i_count)) |
| 337 | WARN_ON(!(inode->i_state & (I_WILL_FREE|I_FREEING))); |
| 338 | else |
| 339 | WARN_ON(inode->i_state & I_WILL_FREE); |
| 340 | |
| 341 | if (inode->i_state & I_SYNC) { |
| 342 | /* |
| 343 | * If this inode is locked for writeback and we are not doing |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 344 | * writeback-for-data-integrity, move it to b_more_io so that |
Christoph Hellwig | 01c0319 | 2009-06-08 13:35:40 +0200 | [diff] [blame] | 345 | * writeback can proceed with the other inodes on s_io. |
| 346 | * |
| 347 | * We'll have another go at writing back this inode when we |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 348 | * completed a full scan of b_io. |
Christoph Hellwig | 01c0319 | 2009-06-08 13:35:40 +0200 | [diff] [blame] | 349 | */ |
Christoph Hellwig | a9185b4 | 2010-03-05 09:21:37 +0100 | [diff] [blame] | 350 | if (wbc->sync_mode != WB_SYNC_ALL) { |
Christoph Hellwig | 01c0319 | 2009-06-08 13:35:40 +0200 | [diff] [blame] | 351 | requeue_io(inode); |
| 352 | return 0; |
| 353 | } |
| 354 | |
| 355 | /* |
| 356 | * It's a data-integrity sync. We must wait. |
| 357 | */ |
| 358 | inode_wait_for_writeback(inode); |
| 359 | } |
| 360 | |
Joern Engel | 1c0eeaf | 2007-10-16 23:30:44 -0700 | [diff] [blame] | 361 | BUG_ON(inode->i_state & I_SYNC); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 362 | |
Dmitry Monakhov | 5547e8a | 2010-05-07 13:35:44 +0400 | [diff] [blame] | 363 | /* Set I_SYNC, reset I_DIRTY_PAGES */ |
Joern Engel | 1c0eeaf | 2007-10-16 23:30:44 -0700 | [diff] [blame] | 364 | inode->i_state |= I_SYNC; |
Dmitry Monakhov | 5547e8a | 2010-05-07 13:35:44 +0400 | [diff] [blame] | 365 | inode->i_state &= ~I_DIRTY_PAGES; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 366 | spin_unlock(&inode_lock); |
| 367 | |
| 368 | ret = do_writepages(mapping, wbc); |
| 369 | |
Christoph Hellwig | 26821ed | 2010-03-05 09:21:21 +0100 | [diff] [blame] | 370 | /* |
| 371 | * Make sure to wait on the data before writing out the metadata. |
| 372 | * This is important for filesystems that modify metadata on data |
| 373 | * I/O completion. |
| 374 | */ |
Christoph Hellwig | a9185b4 | 2010-03-05 09:21:37 +0100 | [diff] [blame] | 375 | if (wbc->sync_mode == WB_SYNC_ALL) { |
Christoph Hellwig | 26821ed | 2010-03-05 09:21:21 +0100 | [diff] [blame] | 376 | int err = filemap_fdatawait(mapping); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 377 | if (ret == 0) |
| 378 | ret = err; |
| 379 | } |
| 380 | |
Dmitry Monakhov | 5547e8a | 2010-05-07 13:35:44 +0400 | [diff] [blame] | 381 | /* |
| 382 | * Some filesystems may redirty the inode during the writeback |
| 383 | * due to delalloc, clear dirty metadata flags right before |
| 384 | * write_inode() |
| 385 | */ |
| 386 | spin_lock(&inode_lock); |
| 387 | dirty = inode->i_state & I_DIRTY; |
| 388 | inode->i_state &= ~(I_DIRTY_SYNC | I_DIRTY_DATASYNC); |
| 389 | spin_unlock(&inode_lock); |
Christoph Hellwig | 26821ed | 2010-03-05 09:21:21 +0100 | [diff] [blame] | 390 | /* Don't write the inode if only I_DIRTY_PAGES was set */ |
| 391 | if (dirty & (I_DIRTY_SYNC | I_DIRTY_DATASYNC)) { |
Christoph Hellwig | a9185b4 | 2010-03-05 09:21:37 +0100 | [diff] [blame] | 392 | int err = write_inode(inode, wbc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 393 | if (ret == 0) |
| 394 | ret = err; |
| 395 | } |
| 396 | |
| 397 | spin_lock(&inode_lock); |
Joern Engel | 1c0eeaf | 2007-10-16 23:30:44 -0700 | [diff] [blame] | 398 | inode->i_state &= ~I_SYNC; |
Al Viro | a4ffdde | 2010-06-02 17:38:30 -0400 | [diff] [blame] | 399 | if (!(inode->i_state & I_FREEING)) { |
Wu Fengguang | 23539af | 2010-08-11 14:17:41 -0700 | [diff] [blame] | 400 | if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 401 | /* |
| 402 | * We didn't write back all the pages. nfs_writepages() |
Wu Fengguang | a50aeb4 | 2010-08-11 14:17:43 -0700 | [diff] [blame] | 403 | * sometimes bales out without doing anything. |
Andrew Morton | 1b43ef9 | 2007-10-16 23:30:35 -0700 | [diff] [blame] | 404 | */ |
Wu Fengguang | a50aeb4 | 2010-08-11 14:17:43 -0700 | [diff] [blame] | 405 | inode->i_state |= I_DIRTY_PAGES; |
| 406 | if (wbc->nr_to_write <= 0) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 407 | /* |
Wu Fengguang | a50aeb4 | 2010-08-11 14:17:43 -0700 | [diff] [blame] | 408 | * slice used up: queue for next turn |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 409 | */ |
Wu Fengguang | a50aeb4 | 2010-08-11 14:17:43 -0700 | [diff] [blame] | 410 | requeue_io(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 411 | } else { |
| 412 | /* |
Wu Fengguang | a50aeb4 | 2010-08-11 14:17:43 -0700 | [diff] [blame] | 413 | * Writeback blocked by something other than |
| 414 | * congestion. Delay the inode for some time to |
| 415 | * avoid spinning on the CPU (100% iowait) |
| 416 | * retrying writeback of the dirty page/inode |
| 417 | * that cannot be performed immediately. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 418 | */ |
Andrew Morton | 1b43ef9 | 2007-10-16 23:30:35 -0700 | [diff] [blame] | 419 | redirty_tail(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 420 | } |
Wu Fengguang | 23539af | 2010-08-11 14:17:41 -0700 | [diff] [blame] | 421 | } else if (inode->i_state & I_DIRTY) { |
| 422 | /* |
| 423 | * Filesystems can dirty the inode during writeback |
| 424 | * operations, such as delayed allocation during |
| 425 | * submission or metadata updates after data IO |
| 426 | * completion. |
| 427 | */ |
| 428 | redirty_tail(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 429 | } else { |
| 430 | /* |
Nick Piggin | 9e38d86 | 2010-10-23 06:55:17 -0400 | [diff] [blame] | 431 | * The inode is clean. At this point we either have |
| 432 | * a reference to the inode or it's on it's way out. |
| 433 | * No need to add it back to the LRU. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 434 | */ |
Nick Piggin | 7ccf19a | 2010-10-21 11:49:30 +1100 | [diff] [blame] | 435 | list_del_init(&inode->i_wb_list); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 436 | } |
| 437 | } |
Joern Engel | 1c0eeaf | 2007-10-16 23:30:44 -0700 | [diff] [blame] | 438 | inode_sync_complete(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 439 | return ret; |
| 440 | } |
| 441 | |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 442 | /* |
Christoph Hellwig | d19de7e | 2010-06-08 18:14:58 +0200 | [diff] [blame] | 443 | * For background writeback the caller does not have the sb pinned |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 444 | * before calling writeback. So make sure that we do pin it, so it doesn't |
| 445 | * go away while we are writing inodes from it. |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 446 | */ |
Christoph Hellwig | d19de7e | 2010-06-08 18:14:58 +0200 | [diff] [blame] | 447 | static bool pin_sb_for_writeback(struct super_block *sb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 448 | { |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 449 | spin_lock(&sb_lock); |
Christoph Hellwig | 29cb4859 | 2010-06-09 15:31:01 +0200 | [diff] [blame] | 450 | if (list_empty(&sb->s_instances)) { |
| 451 | spin_unlock(&sb_lock); |
| 452 | return false; |
| 453 | } |
| 454 | |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 455 | sb->s_count++; |
Christoph Hellwig | 29cb4859 | 2010-06-09 15:31:01 +0200 | [diff] [blame] | 456 | spin_unlock(&sb_lock); |
| 457 | |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 458 | if (down_read_trylock(&sb->s_umount)) { |
Christoph Hellwig | 29cb4859 | 2010-06-09 15:31:01 +0200 | [diff] [blame] | 459 | if (sb->s_root) |
Christoph Hellwig | d19de7e | 2010-06-08 18:14:58 +0200 | [diff] [blame] | 460 | return true; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 461 | up_read(&sb->s_umount); |
| 462 | } |
Christoph Hellwig | 29cb4859 | 2010-06-09 15:31:01 +0200 | [diff] [blame] | 463 | |
| 464 | put_super(sb); |
Christoph Hellwig | d19de7e | 2010-06-08 18:14:58 +0200 | [diff] [blame] | 465 | return false; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 466 | } |
| 467 | |
Edward Shishkin | f11c9c5 | 2010-03-11 14:09:47 -0800 | [diff] [blame] | 468 | /* |
| 469 | * Write a portion of b_io inodes which belong to @sb. |
Christoph Hellwig | edadfb1 | 2010-06-10 12:07:54 +0200 | [diff] [blame] | 470 | * |
| 471 | * If @only_this_sb is true, then find and write all such |
Edward Shishkin | f11c9c5 | 2010-03-11 14:09:47 -0800 | [diff] [blame] | 472 | * inodes. Otherwise write only ones which go sequentially |
| 473 | * in reverse order. |
Christoph Hellwig | edadfb1 | 2010-06-10 12:07:54 +0200 | [diff] [blame] | 474 | * |
Edward Shishkin | f11c9c5 | 2010-03-11 14:09:47 -0800 | [diff] [blame] | 475 | * Return 1, if the caller writeback routine should be |
| 476 | * interrupted. Otherwise return 0. |
| 477 | */ |
Christoph Hellwig | edadfb1 | 2010-06-10 12:07:54 +0200 | [diff] [blame] | 478 | static int writeback_sb_inodes(struct super_block *sb, struct bdi_writeback *wb, |
| 479 | struct writeback_control *wbc, bool only_this_sb) |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 480 | { |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 481 | while (!list_empty(&wb->b_io)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 482 | long pages_skipped; |
Nick Piggin | 7ccf19a | 2010-10-21 11:49:30 +1100 | [diff] [blame] | 483 | struct inode *inode = wb_inode(wb->b_io.prev); |
Christoph Hellwig | edadfb1 | 2010-06-10 12:07:54 +0200 | [diff] [blame] | 484 | |
| 485 | if (inode->i_sb != sb) { |
| 486 | if (only_this_sb) { |
| 487 | /* |
| 488 | * We only want to write back data for this |
| 489 | * superblock, move all inodes not belonging |
| 490 | * to it back onto the dirty list. |
| 491 | */ |
| 492 | redirty_tail(inode); |
| 493 | continue; |
| 494 | } |
| 495 | |
| 496 | /* |
| 497 | * The inode belongs to a different superblock. |
| 498 | * Bounce back to the caller to unpin this and |
| 499 | * pin the next superblock. |
| 500 | */ |
Edward Shishkin | f11c9c5 | 2010-03-11 14:09:47 -0800 | [diff] [blame] | 501 | return 0; |
Christoph Hellwig | edadfb1 | 2010-06-10 12:07:54 +0200 | [diff] [blame] | 502 | } |
| 503 | |
Christoph Hellwig | 9843b76 | 2010-10-24 19:40:46 +0200 | [diff] [blame] | 504 | /* |
| 505 | * Don't bother with new inodes or inodes beeing freed, first |
| 506 | * kind does not need peridic writeout yet, and for the latter |
| 507 | * kind writeout is handled by the freer. |
| 508 | */ |
| 509 | if (inode->i_state & (I_NEW | I_FREEING | I_WILL_FREE)) { |
Nick Piggin | 7ef0d73 | 2009-03-12 14:31:38 -0700 | [diff] [blame] | 510 | requeue_io(inode); |
| 511 | continue; |
| 512 | } |
Christoph Hellwig | 9843b76 | 2010-10-24 19:40:46 +0200 | [diff] [blame] | 513 | |
Jeff Layton | d2caa3c5 | 2009-04-02 16:56:37 -0700 | [diff] [blame] | 514 | /* |
| 515 | * Was this inode dirtied after sync_sb_inodes was called? |
| 516 | * This keeps sync from extra jobs and livelock. |
| 517 | */ |
Edward Shishkin | f11c9c5 | 2010-03-11 14:09:47 -0800 | [diff] [blame] | 518 | if (inode_dirtied_after(inode, wbc->wb_start)) |
| 519 | return 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 520 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 521 | __iget(inode); |
| 522 | pages_skipped = wbc->pages_skipped; |
Christoph Hellwig | 01c0319 | 2009-06-08 13:35:40 +0200 | [diff] [blame] | 523 | writeback_single_inode(inode, wbc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 524 | if (wbc->pages_skipped != pages_skipped) { |
| 525 | /* |
| 526 | * writeback is not making progress due to locked |
| 527 | * buffers. Skip this inode for now. |
| 528 | */ |
Andrew Morton | f57b9b7 | 2007-10-16 23:30:34 -0700 | [diff] [blame] | 529 | redirty_tail(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 530 | } |
| 531 | spin_unlock(&inode_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 532 | iput(inode); |
OGAWA Hirofumi | 4ffc844 | 2006-03-25 03:07:44 -0800 | [diff] [blame] | 533 | cond_resched(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 534 | spin_lock(&inode_lock); |
Fengguang Wu | 8bc3be2 | 2008-02-04 22:29:36 -0800 | [diff] [blame] | 535 | if (wbc->nr_to_write <= 0) { |
| 536 | wbc->more_io = 1; |
Edward Shishkin | f11c9c5 | 2010-03-11 14:09:47 -0800 | [diff] [blame] | 537 | return 1; |
Fengguang Wu | 8bc3be2 | 2008-02-04 22:29:36 -0800 | [diff] [blame] | 538 | } |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 539 | if (!list_empty(&wb->b_more_io)) |
Fengguang Wu | 8bc3be2 | 2008-02-04 22:29:36 -0800 | [diff] [blame] | 540 | wbc->more_io = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 541 | } |
Edward Shishkin | f11c9c5 | 2010-03-11 14:09:47 -0800 | [diff] [blame] | 542 | /* b_io is empty */ |
| 543 | return 1; |
| 544 | } |
Nick Piggin | 38f2197 | 2009-01-06 14:40:25 -0800 | [diff] [blame] | 545 | |
Christoph Hellwig | 9c3a8ee | 2010-06-10 12:07:27 +0200 | [diff] [blame] | 546 | void writeback_inodes_wb(struct bdi_writeback *wb, |
| 547 | struct writeback_control *wbc) |
Edward Shishkin | f11c9c5 | 2010-03-11 14:09:47 -0800 | [diff] [blame] | 548 | { |
| 549 | int ret = 0; |
Jens Axboe | 9ecc273 | 2009-09-24 15:25:11 +0200 | [diff] [blame] | 550 | |
Jan Kara | 7624ee7 | 2010-08-09 17:20:03 -0700 | [diff] [blame] | 551 | if (!wbc->wb_start) |
| 552 | wbc->wb_start = jiffies; /* livelock avoidance */ |
Edward Shishkin | f11c9c5 | 2010-03-11 14:09:47 -0800 | [diff] [blame] | 553 | spin_lock(&inode_lock); |
| 554 | if (!wbc->for_kupdate || list_empty(&wb->b_io)) |
| 555 | queue_io(wb, wbc->older_than_this); |
| 556 | |
| 557 | while (!list_empty(&wb->b_io)) { |
Nick Piggin | 7ccf19a | 2010-10-21 11:49:30 +1100 | [diff] [blame] | 558 | struct inode *inode = wb_inode(wb->b_io.prev); |
Edward Shishkin | f11c9c5 | 2010-03-11 14:09:47 -0800 | [diff] [blame] | 559 | struct super_block *sb = inode->i_sb; |
Edward Shishkin | f11c9c5 | 2010-03-11 14:09:47 -0800 | [diff] [blame] | 560 | |
Christoph Hellwig | edadfb1 | 2010-06-10 12:07:54 +0200 | [diff] [blame] | 561 | if (!pin_sb_for_writeback(sb)) { |
| 562 | requeue_io(inode); |
| 563 | continue; |
Edward Shishkin | f11c9c5 | 2010-03-11 14:09:47 -0800 | [diff] [blame] | 564 | } |
Christoph Hellwig | edadfb1 | 2010-06-10 12:07:54 +0200 | [diff] [blame] | 565 | ret = writeback_sb_inodes(sb, wb, wbc, false); |
| 566 | drop_super(sb); |
Edward Shishkin | f11c9c5 | 2010-03-11 14:09:47 -0800 | [diff] [blame] | 567 | |
Edward Shishkin | f11c9c5 | 2010-03-11 14:09:47 -0800 | [diff] [blame] | 568 | if (ret) |
| 569 | break; |
| 570 | } |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 571 | spin_unlock(&inode_lock); |
| 572 | /* Leave any unwritten inodes on b_io */ |
| 573 | } |
| 574 | |
Christoph Hellwig | edadfb1 | 2010-06-10 12:07:54 +0200 | [diff] [blame] | 575 | static void __writeback_inodes_sb(struct super_block *sb, |
| 576 | struct bdi_writeback *wb, struct writeback_control *wbc) |
| 577 | { |
| 578 | WARN_ON(!rwsem_is_locked(&sb->s_umount)); |
| 579 | |
Christoph Hellwig | edadfb1 | 2010-06-10 12:07:54 +0200 | [diff] [blame] | 580 | spin_lock(&inode_lock); |
| 581 | if (!wbc->for_kupdate || list_empty(&wb->b_io)) |
| 582 | queue_io(wb, wbc->older_than_this); |
| 583 | writeback_sb_inodes(sb, wb, wbc, true); |
| 584 | spin_unlock(&inode_lock); |
| 585 | } |
| 586 | |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 587 | /* |
| 588 | * The maximum number of pages to writeout in a single bdi flush/kupdate |
| 589 | * operation. We do this so we don't hold I_SYNC against an inode for |
| 590 | * enormous amounts of time, which would block a userspace task which has |
| 591 | * been forced to throttle against that inode. Also, the code reevaluates |
| 592 | * the dirty each time it has written this many pages. |
| 593 | */ |
| 594 | #define MAX_WRITEBACK_PAGES 1024 |
| 595 | |
| 596 | static inline bool over_bground_thresh(void) |
| 597 | { |
| 598 | unsigned long background_thresh, dirty_thresh; |
| 599 | |
Wu Fengguang | 16c4042 | 2010-08-11 14:17:39 -0700 | [diff] [blame] | 600 | global_dirty_limits(&background_thresh, &dirty_thresh); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 601 | |
| 602 | return (global_page_state(NR_FILE_DIRTY) + |
Wu Fengguang | 4cbec4c | 2010-10-26 14:21:45 -0700 | [diff] [blame] | 603 | global_page_state(NR_UNSTABLE_NFS) > background_thresh); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 604 | } |
| 605 | |
| 606 | /* |
| 607 | * Explicit flushing or periodic writeback of "old" data. |
| 608 | * |
| 609 | * Define "old": the first time one of an inode's pages is dirtied, we mark the |
| 610 | * dirtying-time in the inode's address_space. So this periodic writeback code |
| 611 | * just walks the superblock inode list, writing back any inodes which are |
| 612 | * older than a specific point in time. |
| 613 | * |
| 614 | * Try to run once per dirty_writeback_interval. But if a writeback event |
| 615 | * takes longer than a dirty_writeback_interval interval, then leave a |
| 616 | * one-second gap. |
| 617 | * |
| 618 | * older_than_this takes precedence over nr_to_write. So we'll only write back |
| 619 | * all dirty pages if they are all attached to "old" mappings. |
| 620 | */ |
Jens Axboe | c4a77a6 | 2009-09-16 15:18:25 +0200 | [diff] [blame] | 621 | static long wb_writeback(struct bdi_writeback *wb, |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 622 | struct wb_writeback_work *work) |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 623 | { |
| 624 | struct writeback_control wbc = { |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 625 | .sync_mode = work->sync_mode, |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 626 | .older_than_this = NULL, |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 627 | .for_kupdate = work->for_kupdate, |
| 628 | .for_background = work->for_background, |
| 629 | .range_cyclic = work->range_cyclic, |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 630 | }; |
| 631 | unsigned long oldest_jif; |
| 632 | long wrote = 0; |
Jan Kara | a5989bd | 2009-09-16 19:22:48 +0200 | [diff] [blame] | 633 | struct inode *inode; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 634 | |
| 635 | if (wbc.for_kupdate) { |
| 636 | wbc.older_than_this = &oldest_jif; |
| 637 | oldest_jif = jiffies - |
| 638 | msecs_to_jiffies(dirty_expire_interval * 10); |
| 639 | } |
Jens Axboe | c4a77a6 | 2009-09-16 15:18:25 +0200 | [diff] [blame] | 640 | if (!wbc.range_cyclic) { |
| 641 | wbc.range_start = 0; |
| 642 | wbc.range_end = LLONG_MAX; |
| 643 | } |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 644 | |
Jan Kara | 7624ee7 | 2010-08-09 17:20:03 -0700 | [diff] [blame] | 645 | wbc.wb_start = jiffies; /* livelock avoidance */ |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 646 | for (;;) { |
| 647 | /* |
Wu Fengguang | d3ddec7 | 2009-09-23 20:33:40 +0800 | [diff] [blame] | 648 | * Stop writeback when nr_pages has been consumed |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 649 | */ |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 650 | if (work->nr_pages <= 0) |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 651 | break; |
| 652 | |
| 653 | /* |
Jan Kara | aa373cf | 2011-01-13 15:45:47 -0800 | [diff] [blame^] | 654 | * Background writeout and kupdate-style writeback may |
| 655 | * run forever. Stop them if there is other work to do |
| 656 | * so that e.g. sync can proceed. They'll be restarted |
| 657 | * after the other works are all done. |
| 658 | */ |
| 659 | if ((work->for_background || work->for_kupdate) && |
| 660 | !list_empty(&wb->bdi->work_list)) |
| 661 | break; |
| 662 | |
| 663 | /* |
Wu Fengguang | d3ddec7 | 2009-09-23 20:33:40 +0800 | [diff] [blame] | 664 | * For background writeout, stop when we are below the |
| 665 | * background dirty threshold |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 666 | */ |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 667 | if (work->for_background && !over_bground_thresh()) |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 668 | break; |
| 669 | |
| 670 | wbc.more_io = 0; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 671 | wbc.nr_to_write = MAX_WRITEBACK_PAGES; |
| 672 | wbc.pages_skipped = 0; |
Dave Chinner | 028c2dd | 2010-07-07 13:24:07 +1000 | [diff] [blame] | 673 | |
| 674 | trace_wbc_writeback_start(&wbc, wb->bdi); |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 675 | if (work->sb) |
| 676 | __writeback_inodes_sb(work->sb, wb, &wbc); |
Christoph Hellwig | edadfb1 | 2010-06-10 12:07:54 +0200 | [diff] [blame] | 677 | else |
| 678 | writeback_inodes_wb(wb, &wbc); |
Dave Chinner | 028c2dd | 2010-07-07 13:24:07 +1000 | [diff] [blame] | 679 | trace_wbc_writeback_written(&wbc, wb->bdi); |
| 680 | |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 681 | work->nr_pages -= MAX_WRITEBACK_PAGES - wbc.nr_to_write; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 682 | wrote += MAX_WRITEBACK_PAGES - wbc.nr_to_write; |
| 683 | |
| 684 | /* |
Jens Axboe | 71fd05a | 2009-09-23 19:32:26 +0200 | [diff] [blame] | 685 | * If we consumed everything, see if we have more |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 686 | */ |
Jens Axboe | 71fd05a | 2009-09-23 19:32:26 +0200 | [diff] [blame] | 687 | if (wbc.nr_to_write <= 0) |
| 688 | continue; |
| 689 | /* |
| 690 | * Didn't write everything and we don't have more IO, bail |
| 691 | */ |
| 692 | if (!wbc.more_io) |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 693 | break; |
Jens Axboe | 71fd05a | 2009-09-23 19:32:26 +0200 | [diff] [blame] | 694 | /* |
| 695 | * Did we write something? Try for more |
| 696 | */ |
| 697 | if (wbc.nr_to_write < MAX_WRITEBACK_PAGES) |
| 698 | continue; |
| 699 | /* |
| 700 | * Nothing written. Wait for some inode to |
| 701 | * become available for writeback. Otherwise |
| 702 | * we'll just busyloop. |
| 703 | */ |
| 704 | spin_lock(&inode_lock); |
| 705 | if (!list_empty(&wb->b_more_io)) { |
Nick Piggin | 7ccf19a | 2010-10-21 11:49:30 +1100 | [diff] [blame] | 706 | inode = wb_inode(wb->b_more_io.prev); |
Dave Chinner | 028c2dd | 2010-07-07 13:24:07 +1000 | [diff] [blame] | 707 | trace_wbc_writeback_wait(&wbc, wb->bdi); |
Jens Axboe | 71fd05a | 2009-09-23 19:32:26 +0200 | [diff] [blame] | 708 | inode_wait_for_writeback(inode); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 709 | } |
Jens Axboe | 71fd05a | 2009-09-23 19:32:26 +0200 | [diff] [blame] | 710 | spin_unlock(&inode_lock); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 711 | } |
| 712 | |
| 713 | return wrote; |
| 714 | } |
| 715 | |
| 716 | /* |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 717 | * Return the next wb_writeback_work struct that hasn't been processed yet. |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 718 | */ |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 719 | static struct wb_writeback_work * |
Minchan Kim | 08852b6 | 2010-08-03 12:51:16 +0200 | [diff] [blame] | 720 | get_next_work_item(struct backing_dev_info *bdi) |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 721 | { |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 722 | struct wb_writeback_work *work = NULL; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 723 | |
Artem Bityutskiy | 6467716 | 2010-07-25 14:29:22 +0300 | [diff] [blame] | 724 | spin_lock_bh(&bdi->wb_lock); |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 725 | if (!list_empty(&bdi->work_list)) { |
| 726 | work = list_entry(bdi->work_list.next, |
| 727 | struct wb_writeback_work, list); |
| 728 | list_del_init(&work->list); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 729 | } |
Artem Bityutskiy | 6467716 | 2010-07-25 14:29:22 +0300 | [diff] [blame] | 730 | spin_unlock_bh(&bdi->wb_lock); |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 731 | return work; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 732 | } |
| 733 | |
Linus Torvalds | cdf01dd | 2010-10-30 08:55:52 -0700 | [diff] [blame] | 734 | /* |
| 735 | * Add in the number of potentially dirty inodes, because each inode |
| 736 | * write can dirty pagecache in the underlying blockdev. |
| 737 | */ |
| 738 | static unsigned long get_nr_dirty_pages(void) |
| 739 | { |
| 740 | return global_page_state(NR_FILE_DIRTY) + |
| 741 | global_page_state(NR_UNSTABLE_NFS) + |
| 742 | get_nr_dirty_inodes(); |
| 743 | } |
| 744 | |
Jan Kara | 6585027 | 2011-01-13 15:45:44 -0800 | [diff] [blame] | 745 | static long wb_check_background_flush(struct bdi_writeback *wb) |
| 746 | { |
| 747 | if (over_bground_thresh()) { |
| 748 | |
| 749 | struct wb_writeback_work work = { |
| 750 | .nr_pages = LONG_MAX, |
| 751 | .sync_mode = WB_SYNC_NONE, |
| 752 | .for_background = 1, |
| 753 | .range_cyclic = 1, |
| 754 | }; |
| 755 | |
| 756 | return wb_writeback(wb, &work); |
| 757 | } |
| 758 | |
| 759 | return 0; |
| 760 | } |
| 761 | |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 762 | static long wb_check_old_data_flush(struct bdi_writeback *wb) |
| 763 | { |
| 764 | unsigned long expired; |
| 765 | long nr_pages; |
| 766 | |
Jens Axboe | 69b62d0 | 2010-05-17 12:51:03 +0200 | [diff] [blame] | 767 | /* |
| 768 | * When set to zero, disable periodic writeback |
| 769 | */ |
| 770 | if (!dirty_writeback_interval) |
| 771 | return 0; |
| 772 | |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 773 | expired = wb->last_old_flush + |
| 774 | msecs_to_jiffies(dirty_writeback_interval * 10); |
| 775 | if (time_before(jiffies, expired)) |
| 776 | return 0; |
| 777 | |
| 778 | wb->last_old_flush = jiffies; |
Linus Torvalds | cdf01dd | 2010-10-30 08:55:52 -0700 | [diff] [blame] | 779 | nr_pages = get_nr_dirty_pages(); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 780 | |
Jens Axboe | c4a77a6 | 2009-09-16 15:18:25 +0200 | [diff] [blame] | 781 | if (nr_pages) { |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 782 | struct wb_writeback_work work = { |
Jens Axboe | c4a77a6 | 2009-09-16 15:18:25 +0200 | [diff] [blame] | 783 | .nr_pages = nr_pages, |
| 784 | .sync_mode = WB_SYNC_NONE, |
| 785 | .for_kupdate = 1, |
| 786 | .range_cyclic = 1, |
| 787 | }; |
| 788 | |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 789 | return wb_writeback(wb, &work); |
Jens Axboe | c4a77a6 | 2009-09-16 15:18:25 +0200 | [diff] [blame] | 790 | } |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 791 | |
| 792 | return 0; |
| 793 | } |
| 794 | |
| 795 | /* |
| 796 | * Retrieve work items and do the writeback they describe |
| 797 | */ |
| 798 | long wb_do_writeback(struct bdi_writeback *wb, int force_wait) |
| 799 | { |
| 800 | struct backing_dev_info *bdi = wb->bdi; |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 801 | struct wb_writeback_work *work; |
Jens Axboe | c4a77a6 | 2009-09-16 15:18:25 +0200 | [diff] [blame] | 802 | long wrote = 0; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 803 | |
Jan Kara | 81d73a3 | 2010-08-11 14:17:44 -0700 | [diff] [blame] | 804 | set_bit(BDI_writeback_running, &wb->bdi->state); |
Minchan Kim | 08852b6 | 2010-08-03 12:51:16 +0200 | [diff] [blame] | 805 | while ((work = get_next_work_item(bdi)) != NULL) { |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 806 | /* |
| 807 | * Override sync mode, in case we must wait for completion |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 808 | * because this thread is exiting now. |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 809 | */ |
| 810 | if (force_wait) |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 811 | work->sync_mode = WB_SYNC_ALL; |
| 812 | |
Dave Chinner | 455b286 | 2010-07-07 13:24:06 +1000 | [diff] [blame] | 813 | trace_writeback_exec(bdi, work); |
| 814 | |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 815 | wrote += wb_writeback(wb, work); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 816 | |
| 817 | /* |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 818 | * Notify the caller of completion if this is a synchronous |
| 819 | * work item, otherwise just free it. |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 820 | */ |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 821 | if (work->done) |
| 822 | complete(work->done); |
| 823 | else |
| 824 | kfree(work); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 825 | } |
| 826 | |
| 827 | /* |
| 828 | * Check for periodic writeback, kupdated() style |
| 829 | */ |
| 830 | wrote += wb_check_old_data_flush(wb); |
Jan Kara | 6585027 | 2011-01-13 15:45:44 -0800 | [diff] [blame] | 831 | wrote += wb_check_background_flush(wb); |
Jan Kara | 81d73a3 | 2010-08-11 14:17:44 -0700 | [diff] [blame] | 832 | clear_bit(BDI_writeback_running, &wb->bdi->state); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 833 | |
| 834 | return wrote; |
| 835 | } |
| 836 | |
| 837 | /* |
| 838 | * Handle writeback of dirty data for the device backed by this bdi. Also |
| 839 | * wakes up periodically and does kupdated style flushing. |
| 840 | */ |
Christoph Hellwig | 0824390 | 2010-06-19 23:08:22 +0200 | [diff] [blame] | 841 | int bdi_writeback_thread(void *data) |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 842 | { |
Christoph Hellwig | 0824390 | 2010-06-19 23:08:22 +0200 | [diff] [blame] | 843 | struct bdi_writeback *wb = data; |
| 844 | struct backing_dev_info *bdi = wb->bdi; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 845 | long pages_written; |
| 846 | |
Peter Zijlstra | 766f916 | 2010-10-26 14:22:45 -0700 | [diff] [blame] | 847 | current->flags |= PF_SWAPWRITE; |
Christoph Hellwig | 0824390 | 2010-06-19 23:08:22 +0200 | [diff] [blame] | 848 | set_freezable(); |
Artem Bityutskiy | ecd5840 | 2010-07-25 14:29:18 +0300 | [diff] [blame] | 849 | wb->last_active = jiffies; |
Christoph Hellwig | 0824390 | 2010-06-19 23:08:22 +0200 | [diff] [blame] | 850 | |
| 851 | /* |
| 852 | * Our parent may run at a different priority, just set us to normal |
| 853 | */ |
| 854 | set_user_nice(current, 0); |
| 855 | |
Dave Chinner | 455b286 | 2010-07-07 13:24:06 +1000 | [diff] [blame] | 856 | trace_writeback_thread_start(bdi); |
| 857 | |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 858 | while (!kthread_should_stop()) { |
Artem Bityutskiy | 6467716 | 2010-07-25 14:29:22 +0300 | [diff] [blame] | 859 | /* |
| 860 | * Remove own delayed wake-up timer, since we are already awake |
| 861 | * and we'll take care of the preriodic write-back. |
| 862 | */ |
| 863 | del_timer(&wb->wakeup_timer); |
| 864 | |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 865 | pages_written = wb_do_writeback(wb, 0); |
| 866 | |
Dave Chinner | 455b286 | 2010-07-07 13:24:06 +1000 | [diff] [blame] | 867 | trace_writeback_pages_written(pages_written); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 868 | |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 869 | if (pages_written) |
Artem Bityutskiy | ecd5840 | 2010-07-25 14:29:18 +0300 | [diff] [blame] | 870 | wb->last_active = jiffies; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 871 | |
Artem Bityutskiy | 297252c | 2010-07-25 14:29:15 +0300 | [diff] [blame] | 872 | set_current_state(TASK_INTERRUPTIBLE); |
J. Bruce Fields | b76b401 | 2010-08-28 08:52:10 +0200 | [diff] [blame] | 873 | if (!list_empty(&bdi->work_list) || kthread_should_stop()) { |
Artem Bityutskiy | 297252c | 2010-07-25 14:29:15 +0300 | [diff] [blame] | 874 | __set_current_state(TASK_RUNNING); |
| 875 | continue; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 876 | } |
| 877 | |
Artem Bityutskiy | 253c34e | 2010-07-25 14:29:21 +0300 | [diff] [blame] | 878 | if (wb_has_dirty_io(wb) && dirty_writeback_interval) |
Artem Bityutskiy | fff5b85 | 2010-07-25 14:29:20 +0300 | [diff] [blame] | 879 | schedule_timeout(msecs_to_jiffies(dirty_writeback_interval * 10)); |
Artem Bityutskiy | 253c34e | 2010-07-25 14:29:21 +0300 | [diff] [blame] | 880 | else { |
| 881 | /* |
| 882 | * We have nothing to do, so can go sleep without any |
| 883 | * timeout and save power. When a work is queued or |
| 884 | * something is made dirty - we will be woken up. |
| 885 | */ |
Artem Bityutskiy | 297252c | 2010-07-25 14:29:15 +0300 | [diff] [blame] | 886 | schedule(); |
Jens Axboe | f9eadbb | 2010-05-18 14:31:45 +0200 | [diff] [blame] | 887 | } |
Jens Axboe | 69b62d0 | 2010-05-17 12:51:03 +0200 | [diff] [blame] | 888 | |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 889 | try_to_freeze(); |
| 890 | } |
| 891 | |
Artem Bityutskiy | fff5b85 | 2010-07-25 14:29:20 +0300 | [diff] [blame] | 892 | /* Flush any work that raced with us exiting */ |
Christoph Hellwig | 0824390 | 2010-06-19 23:08:22 +0200 | [diff] [blame] | 893 | if (!list_empty(&bdi->work_list)) |
| 894 | wb_do_writeback(wb, 1); |
Dave Chinner | 455b286 | 2010-07-07 13:24:06 +1000 | [diff] [blame] | 895 | |
| 896 | trace_writeback_thread_stop(bdi); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 897 | return 0; |
| 898 | } |
| 899 | |
Christoph Hellwig | 0824390 | 2010-06-19 23:08:22 +0200 | [diff] [blame] | 900 | |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 901 | /* |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 902 | * Start writeback of `nr_pages' pages. If `nr_pages' is zero, write back |
| 903 | * the whole world. |
| 904 | */ |
| 905 | void wakeup_flusher_threads(long nr_pages) |
| 906 | { |
Christoph Hellwig | b8c2f34 | 2010-06-08 18:15:07 +0200 | [diff] [blame] | 907 | struct backing_dev_info *bdi; |
Christoph Hellwig | b8c2f34 | 2010-06-08 18:15:07 +0200 | [diff] [blame] | 908 | |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 909 | if (!nr_pages) { |
| 910 | nr_pages = global_page_state(NR_FILE_DIRTY) + |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 911 | global_page_state(NR_UNSTABLE_NFS); |
Christoph Hellwig | b8c2f34 | 2010-06-08 18:15:07 +0200 | [diff] [blame] | 912 | } |
| 913 | |
| 914 | rcu_read_lock(); |
| 915 | list_for_each_entry_rcu(bdi, &bdi_list, bdi_list) { |
| 916 | if (!bdi_has_dirty_io(bdi)) |
| 917 | continue; |
Jan Kara | 6585027 | 2011-01-13 15:45:44 -0800 | [diff] [blame] | 918 | __bdi_start_writeback(bdi, nr_pages, false); |
Christoph Hellwig | b8c2f34 | 2010-06-08 18:15:07 +0200 | [diff] [blame] | 919 | } |
| 920 | rcu_read_unlock(); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 921 | } |
| 922 | |
| 923 | static noinline void block_dump___mark_inode_dirty(struct inode *inode) |
| 924 | { |
| 925 | if (inode->i_ino || strcmp(inode->i_sb->s_id, "bdev")) { |
| 926 | struct dentry *dentry; |
| 927 | const char *name = "?"; |
| 928 | |
| 929 | dentry = d_find_alias(inode); |
| 930 | if (dentry) { |
| 931 | spin_lock(&dentry->d_lock); |
| 932 | name = (const char *) dentry->d_name.name; |
| 933 | } |
| 934 | printk(KERN_DEBUG |
| 935 | "%s(%d): dirtied inode %lu (%s) on %s\n", |
| 936 | current->comm, task_pid_nr(current), inode->i_ino, |
| 937 | name, inode->i_sb->s_id); |
| 938 | if (dentry) { |
| 939 | spin_unlock(&dentry->d_lock); |
| 940 | dput(dentry); |
| 941 | } |
| 942 | } |
| 943 | } |
| 944 | |
| 945 | /** |
| 946 | * __mark_inode_dirty - internal function |
| 947 | * @inode: inode to mark |
| 948 | * @flags: what kind of dirty (i.e. I_DIRTY_SYNC) |
| 949 | * Mark an inode as dirty. Callers should use mark_inode_dirty or |
| 950 | * mark_inode_dirty_sync. |
| 951 | * |
| 952 | * Put the inode on the super block's dirty list. |
| 953 | * |
| 954 | * CAREFUL! We mark it dirty unconditionally, but move it onto the |
| 955 | * dirty list only if it is hashed or if it refers to a blockdev. |
| 956 | * If it was not hashed, it will never be added to the dirty list |
| 957 | * even if it is later hashed, as it will have been marked dirty already. |
| 958 | * |
| 959 | * In short, make sure you hash any inodes _before_ you start marking |
| 960 | * them dirty. |
| 961 | * |
| 962 | * This function *must* be atomic for the I_DIRTY_PAGES case - |
| 963 | * set_page_dirty() is called under spinlock in several places. |
| 964 | * |
| 965 | * Note that for blockdevs, inode->dirtied_when represents the dirtying time of |
| 966 | * the block-special inode (/dev/hda1) itself. And the ->dirtied_when field of |
| 967 | * the kernel-internal blockdev inode represents the dirtying time of the |
| 968 | * blockdev's pages. This is why for I_DIRTY_PAGES we always use |
| 969 | * page->mapping->host, so the page-dirtying time is recorded in the internal |
| 970 | * blockdev inode. |
| 971 | */ |
| 972 | void __mark_inode_dirty(struct inode *inode, int flags) |
| 973 | { |
| 974 | struct super_block *sb = inode->i_sb; |
Artem Bityutskiy | 253c34e | 2010-07-25 14:29:21 +0300 | [diff] [blame] | 975 | struct backing_dev_info *bdi = NULL; |
| 976 | bool wakeup_bdi = false; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 977 | |
| 978 | /* |
| 979 | * Don't do this for I_DIRTY_PAGES - that doesn't actually |
| 980 | * dirty the inode itself |
| 981 | */ |
| 982 | if (flags & (I_DIRTY_SYNC | I_DIRTY_DATASYNC)) { |
| 983 | if (sb->s_op->dirty_inode) |
| 984 | sb->s_op->dirty_inode(inode); |
| 985 | } |
| 986 | |
| 987 | /* |
| 988 | * make sure that changes are seen by all cpus before we test i_state |
| 989 | * -- mikulas |
| 990 | */ |
| 991 | smp_mb(); |
| 992 | |
| 993 | /* avoid the locking if we can */ |
| 994 | if ((inode->i_state & flags) == flags) |
| 995 | return; |
| 996 | |
| 997 | if (unlikely(block_dump)) |
| 998 | block_dump___mark_inode_dirty(inode); |
| 999 | |
| 1000 | spin_lock(&inode_lock); |
| 1001 | if ((inode->i_state & flags) != flags) { |
| 1002 | const int was_dirty = inode->i_state & I_DIRTY; |
| 1003 | |
| 1004 | inode->i_state |= flags; |
| 1005 | |
| 1006 | /* |
| 1007 | * If the inode is being synced, just update its dirty state. |
| 1008 | * The unlocker will place the inode on the appropriate |
| 1009 | * superblock list, based upon its state. |
| 1010 | */ |
| 1011 | if (inode->i_state & I_SYNC) |
| 1012 | goto out; |
| 1013 | |
| 1014 | /* |
| 1015 | * Only add valid (hashed) inodes to the superblock's |
| 1016 | * dirty list. Add blockdev inodes as well. |
| 1017 | */ |
| 1018 | if (!S_ISBLK(inode->i_mode)) { |
Al Viro | 1d3382cb | 2010-10-23 15:19:20 -0400 | [diff] [blame] | 1019 | if (inode_unhashed(inode)) |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1020 | goto out; |
| 1021 | } |
Al Viro | a4ffdde | 2010-06-02 17:38:30 -0400 | [diff] [blame] | 1022 | if (inode->i_state & I_FREEING) |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1023 | goto out; |
| 1024 | |
| 1025 | /* |
| 1026 | * If the inode was already on b_dirty/b_io/b_more_io, don't |
| 1027 | * reposition it (that would break b_dirty time-ordering). |
| 1028 | */ |
| 1029 | if (!was_dirty) { |
Artem Bityutskiy | 253c34e | 2010-07-25 14:29:21 +0300 | [diff] [blame] | 1030 | bdi = inode_to_bdi(inode); |
Jens Axboe | 500b067 | 2009-09-09 09:10:25 +0200 | [diff] [blame] | 1031 | |
Artem Bityutskiy | 253c34e | 2010-07-25 14:29:21 +0300 | [diff] [blame] | 1032 | if (bdi_cap_writeback_dirty(bdi)) { |
| 1033 | WARN(!test_bit(BDI_registered, &bdi->state), |
| 1034 | "bdi-%s not registered\n", bdi->name); |
| 1035 | |
| 1036 | /* |
| 1037 | * If this is the first dirty inode for this |
| 1038 | * bdi, we have to wake-up the corresponding |
| 1039 | * bdi thread to make sure background |
| 1040 | * write-back happens later. |
| 1041 | */ |
| 1042 | if (!wb_has_dirty_io(&bdi->wb)) |
| 1043 | wakeup_bdi = true; |
Jens Axboe | 500b067 | 2009-09-09 09:10:25 +0200 | [diff] [blame] | 1044 | } |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1045 | |
| 1046 | inode->dirtied_when = jiffies; |
Nick Piggin | 7ccf19a | 2010-10-21 11:49:30 +1100 | [diff] [blame] | 1047 | list_move(&inode->i_wb_list, &bdi->wb.b_dirty); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1048 | } |
| 1049 | } |
| 1050 | out: |
| 1051 | spin_unlock(&inode_lock); |
Artem Bityutskiy | 253c34e | 2010-07-25 14:29:21 +0300 | [diff] [blame] | 1052 | |
| 1053 | if (wakeup_bdi) |
Artem Bityutskiy | 6467716 | 2010-07-25 14:29:22 +0300 | [diff] [blame] | 1054 | bdi_wakeup_thread_delayed(bdi); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1055 | } |
| 1056 | EXPORT_SYMBOL(__mark_inode_dirty); |
| 1057 | |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 1058 | /* |
| 1059 | * Write out a superblock's list of dirty inodes. A wait will be performed |
| 1060 | * upon no inodes, all inodes or the final one, depending upon sync_mode. |
| 1061 | * |
| 1062 | * If older_than_this is non-NULL, then only write out inodes which |
| 1063 | * had their first dirtying at a time earlier than *older_than_this. |
| 1064 | * |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 1065 | * If `bdi' is non-zero then we're being asked to writeback a specific queue. |
| 1066 | * This function assumes that the blockdev superblock's inodes are backed by |
| 1067 | * a variety of queues, so all inodes are searched. For other superblocks, |
| 1068 | * assume that all inodes are backed by the same queue. |
| 1069 | * |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 1070 | * The inodes to be written are parked on bdi->b_io. They are moved back onto |
| 1071 | * bdi->b_dirty as they are selected for writing. This way, none can be missed |
| 1072 | * on the writer throttling path, and we get decent balancing between many |
| 1073 | * throttled threads: we don't want them all piling up on inode_sync_wait. |
| 1074 | */ |
Jens Axboe | b6e5131 | 2009-09-16 15:13:54 +0200 | [diff] [blame] | 1075 | static void wait_sb_inodes(struct super_block *sb) |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 1076 | { |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1077 | struct inode *inode, *old_inode = NULL; |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 1078 | |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1079 | /* |
| 1080 | * We need to be protected against the filesystem going from |
| 1081 | * r/o to r/w or vice versa. |
| 1082 | */ |
Jens Axboe | b6e5131 | 2009-09-16 15:13:54 +0200 | [diff] [blame] | 1083 | WARN_ON(!rwsem_is_locked(&sb->s_umount)); |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 1084 | |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1085 | spin_lock(&inode_lock); |
| 1086 | |
| 1087 | /* |
| 1088 | * Data integrity sync. Must wait for all pages under writeback, |
| 1089 | * because there may have been pages dirtied before our sync |
| 1090 | * call, but which had writeout started before we write it out. |
| 1091 | * In which case, the inode may not be on the dirty list, but |
| 1092 | * we still have to wait for that writeout. |
| 1093 | */ |
Jens Axboe | b6e5131 | 2009-09-16 15:13:54 +0200 | [diff] [blame] | 1094 | list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1095 | struct address_space *mapping; |
| 1096 | |
Al Viro | a4ffdde | 2010-06-02 17:38:30 -0400 | [diff] [blame] | 1097 | if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1098 | continue; |
| 1099 | mapping = inode->i_mapping; |
| 1100 | if (mapping->nrpages == 0) |
| 1101 | continue; |
| 1102 | __iget(inode); |
| 1103 | spin_unlock(&inode_lock); |
| 1104 | /* |
| 1105 | * We hold a reference to 'inode' so it couldn't have |
| 1106 | * been removed from s_inodes list while we dropped the |
| 1107 | * inode_lock. We cannot iput the inode now as we can |
| 1108 | * be holding the last reference and we cannot iput it |
| 1109 | * under inode_lock. So we keep the reference and iput |
| 1110 | * it later. |
| 1111 | */ |
| 1112 | iput(old_inode); |
| 1113 | old_inode = inode; |
| 1114 | |
| 1115 | filemap_fdatawait(mapping); |
| 1116 | |
| 1117 | cond_resched(); |
Nick Piggin | 38f2197 | 2009-01-06 14:40:25 -0800 | [diff] [blame] | 1118 | |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 1119 | spin_lock(&inode_lock); |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 1120 | } |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1121 | spin_unlock(&inode_lock); |
| 1122 | iput(old_inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1123 | } |
| 1124 | |
Jens Axboe | d8a8559 | 2009-09-02 12:34:32 +0200 | [diff] [blame] | 1125 | /** |
Chris Mason | 3259f8b | 2010-10-29 11:16:17 -0400 | [diff] [blame] | 1126 | * writeback_inodes_sb_nr - writeback dirty inodes from given super_block |
Jens Axboe | d8a8559 | 2009-09-02 12:34:32 +0200 | [diff] [blame] | 1127 | * @sb: the superblock |
Chris Mason | 3259f8b | 2010-10-29 11:16:17 -0400 | [diff] [blame] | 1128 | * @nr: the number of pages to write |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1129 | * |
Jens Axboe | d8a8559 | 2009-09-02 12:34:32 +0200 | [diff] [blame] | 1130 | * Start writeback on some inodes on this super_block. No guarantees are made |
| 1131 | * on how many (if any) will be written, and this function does not wait |
Chris Mason | 3259f8b | 2010-10-29 11:16:17 -0400 | [diff] [blame] | 1132 | * for IO completion of submitted IO. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1133 | */ |
Chris Mason | 3259f8b | 2010-10-29 11:16:17 -0400 | [diff] [blame] | 1134 | void writeback_inodes_sb_nr(struct super_block *sb, unsigned long nr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1135 | { |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 1136 | DECLARE_COMPLETION_ONSTACK(done); |
| 1137 | struct wb_writeback_work work = { |
Christoph Hellwig | 3c4d716 | 2010-06-08 18:14:43 +0200 | [diff] [blame] | 1138 | .sb = sb, |
| 1139 | .sync_mode = WB_SYNC_NONE, |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 1140 | .done = &done, |
Chris Mason | 3259f8b | 2010-10-29 11:16:17 -0400 | [diff] [blame] | 1141 | .nr_pages = nr, |
Christoph Hellwig | 3c4d716 | 2010-06-08 18:14:43 +0200 | [diff] [blame] | 1142 | }; |
Jens Axboe | 0e3c9a2 | 2010-06-01 11:08:43 +0200 | [diff] [blame] | 1143 | |
Christoph Hellwig | cf37e97 | 2010-06-08 18:14:51 +0200 | [diff] [blame] | 1144 | WARN_ON(!rwsem_is_locked(&sb->s_umount)); |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 1145 | bdi_queue_work(sb->s_bdi, &work); |
| 1146 | wait_for_completion(&done); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1147 | } |
Chris Mason | 3259f8b | 2010-10-29 11:16:17 -0400 | [diff] [blame] | 1148 | EXPORT_SYMBOL(writeback_inodes_sb_nr); |
| 1149 | |
| 1150 | /** |
| 1151 | * writeback_inodes_sb - writeback dirty inodes from given super_block |
| 1152 | * @sb: the superblock |
| 1153 | * |
| 1154 | * Start writeback on some inodes on this super_block. No guarantees are made |
| 1155 | * on how many (if any) will be written, and this function does not wait |
| 1156 | * for IO completion of submitted IO. |
| 1157 | */ |
| 1158 | void writeback_inodes_sb(struct super_block *sb) |
| 1159 | { |
Linus Torvalds | 925d169 | 2010-10-30 09:05:48 -0700 | [diff] [blame] | 1160 | return writeback_inodes_sb_nr(sb, get_nr_dirty_pages()); |
Chris Mason | 3259f8b | 2010-10-29 11:16:17 -0400 | [diff] [blame] | 1161 | } |
Jens Axboe | d8a8559 | 2009-09-02 12:34:32 +0200 | [diff] [blame] | 1162 | EXPORT_SYMBOL(writeback_inodes_sb); |
| 1163 | |
| 1164 | /** |
Eric Sandeen | 17bd55d | 2009-12-23 07:57:07 -0500 | [diff] [blame] | 1165 | * writeback_inodes_sb_if_idle - start writeback if none underway |
| 1166 | * @sb: the superblock |
| 1167 | * |
| 1168 | * Invoke writeback_inodes_sb if no writeback is currently underway. |
| 1169 | * Returns 1 if writeback was started, 0 if not. |
| 1170 | */ |
| 1171 | int writeback_inodes_sb_if_idle(struct super_block *sb) |
| 1172 | { |
| 1173 | if (!writeback_in_progress(sb->s_bdi)) { |
Christoph Hellwig | cf37e97 | 2010-06-08 18:14:51 +0200 | [diff] [blame] | 1174 | down_read(&sb->s_umount); |
Eric Sandeen | 17bd55d | 2009-12-23 07:57:07 -0500 | [diff] [blame] | 1175 | writeback_inodes_sb(sb); |
Christoph Hellwig | cf37e97 | 2010-06-08 18:14:51 +0200 | [diff] [blame] | 1176 | up_read(&sb->s_umount); |
Eric Sandeen | 17bd55d | 2009-12-23 07:57:07 -0500 | [diff] [blame] | 1177 | return 1; |
| 1178 | } else |
| 1179 | return 0; |
| 1180 | } |
| 1181 | EXPORT_SYMBOL(writeback_inodes_sb_if_idle); |
| 1182 | |
| 1183 | /** |
Chris Mason | 3259f8b | 2010-10-29 11:16:17 -0400 | [diff] [blame] | 1184 | * writeback_inodes_sb_if_idle - start writeback if none underway |
| 1185 | * @sb: the superblock |
| 1186 | * @nr: the number of pages to write |
| 1187 | * |
| 1188 | * Invoke writeback_inodes_sb if no writeback is currently underway. |
| 1189 | * Returns 1 if writeback was started, 0 if not. |
| 1190 | */ |
| 1191 | int writeback_inodes_sb_nr_if_idle(struct super_block *sb, |
| 1192 | unsigned long nr) |
| 1193 | { |
| 1194 | if (!writeback_in_progress(sb->s_bdi)) { |
| 1195 | down_read(&sb->s_umount); |
| 1196 | writeback_inodes_sb_nr(sb, nr); |
| 1197 | up_read(&sb->s_umount); |
| 1198 | return 1; |
| 1199 | } else |
| 1200 | return 0; |
| 1201 | } |
| 1202 | EXPORT_SYMBOL(writeback_inodes_sb_nr_if_idle); |
| 1203 | |
| 1204 | /** |
Jens Axboe | d8a8559 | 2009-09-02 12:34:32 +0200 | [diff] [blame] | 1205 | * sync_inodes_sb - sync sb inode pages |
| 1206 | * @sb: the superblock |
| 1207 | * |
| 1208 | * This function writes and waits on any dirty inode belonging to this |
| 1209 | * super_block. The number of pages synced is returned. |
| 1210 | */ |
Jens Axboe | b6e5131 | 2009-09-16 15:13:54 +0200 | [diff] [blame] | 1211 | void sync_inodes_sb(struct super_block *sb) |
Jens Axboe | d8a8559 | 2009-09-02 12:34:32 +0200 | [diff] [blame] | 1212 | { |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 1213 | DECLARE_COMPLETION_ONSTACK(done); |
| 1214 | struct wb_writeback_work work = { |
Christoph Hellwig | 3c4d716 | 2010-06-08 18:14:43 +0200 | [diff] [blame] | 1215 | .sb = sb, |
| 1216 | .sync_mode = WB_SYNC_ALL, |
| 1217 | .nr_pages = LONG_MAX, |
| 1218 | .range_cyclic = 0, |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 1219 | .done = &done, |
Christoph Hellwig | 3c4d716 | 2010-06-08 18:14:43 +0200 | [diff] [blame] | 1220 | }; |
| 1221 | |
Christoph Hellwig | cf37e97 | 2010-06-08 18:14:51 +0200 | [diff] [blame] | 1222 | WARN_ON(!rwsem_is_locked(&sb->s_umount)); |
| 1223 | |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 1224 | bdi_queue_work(sb->s_bdi, &work); |
| 1225 | wait_for_completion(&done); |
| 1226 | |
Jens Axboe | b6e5131 | 2009-09-16 15:13:54 +0200 | [diff] [blame] | 1227 | wait_sb_inodes(sb); |
Jens Axboe | d8a8559 | 2009-09-02 12:34:32 +0200 | [diff] [blame] | 1228 | } |
| 1229 | EXPORT_SYMBOL(sync_inodes_sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1230 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1231 | /** |
Andrea Arcangeli | 7f04c26 | 2005-10-30 15:03:05 -0800 | [diff] [blame] | 1232 | * write_inode_now - write an inode to disk |
| 1233 | * @inode: inode to write to disk |
| 1234 | * @sync: whether the write should be synchronous or not |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1235 | * |
Andrea Arcangeli | 7f04c26 | 2005-10-30 15:03:05 -0800 | [diff] [blame] | 1236 | * This function commits an inode to disk immediately if it is dirty. This is |
| 1237 | * primarily needed by knfsd. |
| 1238 | * |
| 1239 | * The caller must either have a ref on the inode or must have set I_WILL_FREE. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1240 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1241 | int write_inode_now(struct inode *inode, int sync) |
| 1242 | { |
| 1243 | int ret; |
| 1244 | struct writeback_control wbc = { |
| 1245 | .nr_to_write = LONG_MAX, |
Mike Galbraith | 18914b1 | 2008-02-08 04:20:23 -0800 | [diff] [blame] | 1246 | .sync_mode = sync ? WB_SYNC_ALL : WB_SYNC_NONE, |
OGAWA Hirofumi | 111ebb6 | 2006-06-23 02:03:26 -0700 | [diff] [blame] | 1247 | .range_start = 0, |
| 1248 | .range_end = LLONG_MAX, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1249 | }; |
| 1250 | |
| 1251 | if (!mapping_cap_writeback_dirty(inode->i_mapping)) |
Andrew Morton | 49364ce | 2005-11-07 00:59:15 -0800 | [diff] [blame] | 1252 | wbc.nr_to_write = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1253 | |
| 1254 | might_sleep(); |
| 1255 | spin_lock(&inode_lock); |
Christoph Hellwig | 01c0319 | 2009-06-08 13:35:40 +0200 | [diff] [blame] | 1256 | ret = writeback_single_inode(inode, &wbc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1257 | spin_unlock(&inode_lock); |
| 1258 | if (sync) |
Joern Engel | 1c0eeaf | 2007-10-16 23:30:44 -0700 | [diff] [blame] | 1259 | inode_sync_wait(inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1260 | return ret; |
| 1261 | } |
| 1262 | EXPORT_SYMBOL(write_inode_now); |
| 1263 | |
| 1264 | /** |
| 1265 | * sync_inode - write an inode and its pages to disk. |
| 1266 | * @inode: the inode to sync |
| 1267 | * @wbc: controls the writeback mode |
| 1268 | * |
| 1269 | * sync_inode() will write an inode and its pages to disk. It will also |
| 1270 | * correctly update the inode on its superblock's dirty inode lists and will |
| 1271 | * update inode->i_state. |
| 1272 | * |
| 1273 | * The caller must have a ref on the inode. |
| 1274 | */ |
| 1275 | int sync_inode(struct inode *inode, struct writeback_control *wbc) |
| 1276 | { |
| 1277 | int ret; |
| 1278 | |
| 1279 | spin_lock(&inode_lock); |
Christoph Hellwig | 01c0319 | 2009-06-08 13:35:40 +0200 | [diff] [blame] | 1280 | ret = writeback_single_inode(inode, wbc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1281 | spin_unlock(&inode_lock); |
| 1282 | return ret; |
| 1283 | } |
| 1284 | EXPORT_SYMBOL(sync_inode); |
Christoph Hellwig | c3765016 | 2010-10-06 10:48:20 +0200 | [diff] [blame] | 1285 | |
| 1286 | /** |
| 1287 | * sync_inode - write an inode to disk |
| 1288 | * @inode: the inode to sync |
| 1289 | * @wait: wait for I/O to complete. |
| 1290 | * |
| 1291 | * Write an inode to disk and adjust it's dirty state after completion. |
| 1292 | * |
| 1293 | * Note: only writes the actual inode, no associated data or other metadata. |
| 1294 | */ |
| 1295 | int sync_inode_metadata(struct inode *inode, int wait) |
| 1296 | { |
| 1297 | struct writeback_control wbc = { |
| 1298 | .sync_mode = wait ? WB_SYNC_ALL : WB_SYNC_NONE, |
| 1299 | .nr_to_write = 0, /* metadata-only */ |
| 1300 | }; |
| 1301 | |
| 1302 | return sync_inode(inode, &wbc); |
| 1303 | } |
| 1304 | EXPORT_SYMBOL(sync_inode_metadata); |