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> |
Paul Gortmaker | 630d9c4 | 2011-11-16 23:57:37 -0500 | [diff] [blame] | 17 | #include <linux/export.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> |
Wu Fengguang | bc31b86 | 2012-01-07 20:41:55 -0600 | [diff] [blame] | 23 | #include <linux/pagemap.h> |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 24 | #include <linux/kthread.h> |
| 25 | #include <linux/freezer.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 26 | #include <linux/writeback.h> |
| 27 | #include <linux/blkdev.h> |
| 28 | #include <linux/backing-dev.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 | /* |
Wu Fengguang | bc31b86 | 2012-01-07 20:41:55 -0600 | [diff] [blame] | 33 | * 4MB minimal write chunk size |
| 34 | */ |
| 35 | #define MIN_WRITEBACK_PAGES (4096UL >> (PAGE_CACHE_SHIFT - 10)) |
| 36 | |
| 37 | /* |
Jens Axboe | c4a77a6 | 2009-09-16 15:18:25 +0200 | [diff] [blame] | 38 | * Passed into wb_writeback(), essentially a subset of writeback_control |
| 39 | */ |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 40 | struct wb_writeback_work { |
Jens Axboe | c4a77a6 | 2009-09-16 15:18:25 +0200 | [diff] [blame] | 41 | long nr_pages; |
| 42 | struct super_block *sb; |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 43 | unsigned long *older_than_this; |
Jens Axboe | c4a77a6 | 2009-09-16 15:18:25 +0200 | [diff] [blame] | 44 | enum writeback_sync_modes sync_mode; |
Wu Fengguang | 6e6938b | 2010-06-06 10:38:15 -0600 | [diff] [blame] | 45 | unsigned int tagged_writepages:1; |
H Hartley Sweeten | 52957fe | 2010-04-01 20:36:30 -0500 | [diff] [blame] | 46 | unsigned int for_kupdate:1; |
| 47 | unsigned int range_cyclic:1; |
| 48 | unsigned int for_background:1; |
Curt Wohlgemuth | 0e175a1 | 2011-10-07 21:54:10 -0600 | [diff] [blame] | 49 | enum wb_reason reason; /* why was writeback initiated? */ |
Jens Axboe | c4a77a6 | 2009-09-16 15:18:25 +0200 | [diff] [blame] | 50 | |
Jens Axboe | 8010c3b | 2009-09-15 20:04:57 +0200 | [diff] [blame] | 51 | struct list_head list; /* pending work list */ |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 52 | struct completion *done; /* set if the caller waits */ |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 53 | }; |
| 54 | |
Adrian Bunk | f11b00f | 2008-04-29 00:58:56 -0700 | [diff] [blame] | 55 | /** |
| 56 | * writeback_in_progress - determine whether there is writeback in progress |
| 57 | * @bdi: the device's backing_dev_info structure. |
| 58 | * |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 59 | * Determine whether there is writeback waiting to be handled against a |
| 60 | * backing device. |
Adrian Bunk | f11b00f | 2008-04-29 00:58:56 -0700 | [diff] [blame] | 61 | */ |
| 62 | int writeback_in_progress(struct backing_dev_info *bdi) |
| 63 | { |
Jan Kara | 81d73a3 | 2010-08-11 14:17:44 -0700 | [diff] [blame] | 64 | return test_bit(BDI_writeback_running, &bdi->state); |
Adrian Bunk | f11b00f | 2008-04-29 00:58:56 -0700 | [diff] [blame] | 65 | } |
Theodore Ts'o | 00d4e73 | 2012-09-19 22:42:36 -0400 | [diff] [blame] | 66 | EXPORT_SYMBOL(writeback_in_progress); |
Adrian Bunk | f11b00f | 2008-04-29 00:58:56 -0700 | [diff] [blame] | 67 | |
Jan Kara | 692ebd1 | 2010-09-21 11:51:01 +0200 | [diff] [blame] | 68 | static inline struct backing_dev_info *inode_to_bdi(struct inode *inode) |
| 69 | { |
| 70 | struct super_block *sb = inode->i_sb; |
Jan Kara | 692ebd1 | 2010-09-21 11:51:01 +0200 | [diff] [blame] | 71 | |
Christoph Hellwig | aaead25 | 2010-10-04 14:25:33 +0200 | [diff] [blame] | 72 | if (strcmp(sb->s_type->name, "bdev") == 0) |
| 73 | return inode->i_mapping->backing_dev_info; |
| 74 | |
| 75 | return sb->s_bdi; |
Jan Kara | 692ebd1 | 2010-09-21 11:51:01 +0200 | [diff] [blame] | 76 | } |
| 77 | |
Nick Piggin | 7ccf19a | 2010-10-21 11:49:30 +1100 | [diff] [blame] | 78 | static inline struct inode *wb_inode(struct list_head *head) |
| 79 | { |
| 80 | return list_entry(head, struct inode, i_wb_list); |
| 81 | } |
| 82 | |
Wu Fengguang | 15eb77a | 2012-01-17 11:18:56 -0600 | [diff] [blame] | 83 | /* |
| 84 | * Include the creation of the trace points after defining the |
| 85 | * wb_writeback_work structure and inline functions so that the definition |
| 86 | * remains local to this file. |
| 87 | */ |
| 88 | #define CREATE_TRACE_POINTS |
| 89 | #include <trace/events/writeback.h> |
| 90 | |
Jan Kara | 6585027 | 2011-01-13 15:45:44 -0800 | [diff] [blame] | 91 | /* Wakeup flusher thread or forker thread to fork it. Requires bdi->wb_lock. */ |
| 92 | static void bdi_wakeup_flusher(struct backing_dev_info *bdi) |
Nick Piggin | 4195f73 | 2009-05-28 09:01:15 +0200 | [diff] [blame] | 93 | { |
Artem Bityutskiy | fff5b85 | 2010-07-25 14:29:20 +0300 | [diff] [blame] | 94 | if (bdi->wb.task) { |
| 95 | wake_up_process(bdi->wb.task); |
| 96 | } else { |
| 97 | /* |
| 98 | * The bdi thread isn't there, wake up the forker thread which |
| 99 | * will create and run it. |
| 100 | */ |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 101 | wake_up_process(default_backing_dev_info.wb.task); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 102 | } |
Jan Kara | 6585027 | 2011-01-13 15:45:44 -0800 | [diff] [blame] | 103 | } |
| 104 | |
| 105 | static void bdi_queue_work(struct backing_dev_info *bdi, |
| 106 | struct wb_writeback_work *work) |
| 107 | { |
| 108 | trace_writeback_queue(bdi, work); |
| 109 | |
| 110 | spin_lock_bh(&bdi->wb_lock); |
| 111 | list_add_tail(&work->list, &bdi->work_list); |
| 112 | if (!bdi->wb.task) |
| 113 | trace_writeback_nothread(bdi, work); |
| 114 | bdi_wakeup_flusher(bdi); |
Artem Bityutskiy | 6467716 | 2010-07-25 14:29:22 +0300 | [diff] [blame] | 115 | spin_unlock_bh(&bdi->wb_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 116 | } |
| 117 | |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 118 | static void |
| 119 | __bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages, |
Curt Wohlgemuth | 0e175a1 | 2011-10-07 21:54:10 -0600 | [diff] [blame] | 120 | bool range_cyclic, enum wb_reason reason) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 121 | { |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 122 | struct wb_writeback_work *work; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 123 | |
Jens Axboe | bcddc3f | 2009-09-13 20:07:36 +0200 | [diff] [blame] | 124 | /* |
| 125 | * This is WB_SYNC_NONE writeback, so if allocation fails just |
| 126 | * wakeup the thread for old dirty data writeback |
| 127 | */ |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 128 | work = kzalloc(sizeof(*work), GFP_ATOMIC); |
| 129 | if (!work) { |
Dave Chinner | 455b286 | 2010-07-07 13:24:06 +1000 | [diff] [blame] | 130 | if (bdi->wb.task) { |
| 131 | trace_writeback_nowork(bdi); |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 132 | wake_up_process(bdi->wb.task); |
Dave Chinner | 455b286 | 2010-07-07 13:24:06 +1000 | [diff] [blame] | 133 | } |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 134 | return; |
Jens Axboe | bcddc3f | 2009-09-13 20:07:36 +0200 | [diff] [blame] | 135 | } |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 136 | |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 137 | work->sync_mode = WB_SYNC_NONE; |
| 138 | work->nr_pages = nr_pages; |
| 139 | work->range_cyclic = range_cyclic; |
Curt Wohlgemuth | 0e175a1 | 2011-10-07 21:54:10 -0600 | [diff] [blame] | 140 | work->reason = reason; |
Christoph Hellwig | f0fad8a | 2009-09-11 09:47:56 +0200 | [diff] [blame] | 141 | |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 142 | bdi_queue_work(bdi, work); |
Jens Axboe | b6e5131 | 2009-09-16 15:13:54 +0200 | [diff] [blame] | 143 | } |
| 144 | |
| 145 | /** |
| 146 | * bdi_start_writeback - start writeback |
| 147 | * @bdi: the backing device to write from |
| 148 | * @nr_pages: the number of pages to write |
Marcos Paulo de Souza | 786228a | 2011-11-23 20:56:45 +0800 | [diff] [blame] | 149 | * @reason: reason why some writeback work was initiated |
Jens Axboe | b6e5131 | 2009-09-16 15:13:54 +0200 | [diff] [blame] | 150 | * |
| 151 | * Description: |
| 152 | * This does WB_SYNC_NONE opportunistic writeback. The IO is only |
Lucas De Marchi | 25985ed | 2011-03-30 22:57:33 -0300 | [diff] [blame] | 153 | * started when this function returns, we make no guarantees on |
Jens Axboe | 0e3c9a2 | 2010-06-01 11:08:43 +0200 | [diff] [blame] | 154 | * completion. Caller need not hold sb s_umount semaphore. |
Jens Axboe | b6e5131 | 2009-09-16 15:13:54 +0200 | [diff] [blame] | 155 | * |
| 156 | */ |
Curt Wohlgemuth | 0e175a1 | 2011-10-07 21:54:10 -0600 | [diff] [blame] | 157 | void bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages, |
| 158 | enum wb_reason reason) |
Jens Axboe | b6e5131 | 2009-09-16 15:13:54 +0200 | [diff] [blame] | 159 | { |
Curt Wohlgemuth | 0e175a1 | 2011-10-07 21:54:10 -0600 | [diff] [blame] | 160 | __bdi_start_writeback(bdi, nr_pages, true, reason); |
Christoph Hellwig | c544419 | 2010-06-08 18:15:15 +0200 | [diff] [blame] | 161 | } |
Wu Fengguang | d3ddec7 | 2009-09-23 20:33:40 +0800 | [diff] [blame] | 162 | |
Christoph Hellwig | c544419 | 2010-06-08 18:15:15 +0200 | [diff] [blame] | 163 | /** |
| 164 | * bdi_start_background_writeback - start background writeback |
| 165 | * @bdi: the backing device to write from |
| 166 | * |
| 167 | * Description: |
Jan Kara | 6585027 | 2011-01-13 15:45:44 -0800 | [diff] [blame] | 168 | * This makes sure WB_SYNC_NONE background writeback happens. When |
| 169 | * this function returns, it is only guaranteed that for given BDI |
| 170 | * some IO is happening if we are over background dirty threshold. |
| 171 | * Caller need not hold sb s_umount semaphore. |
Christoph Hellwig | c544419 | 2010-06-08 18:15:15 +0200 | [diff] [blame] | 172 | */ |
| 173 | void bdi_start_background_writeback(struct backing_dev_info *bdi) |
| 174 | { |
Jan Kara | 6585027 | 2011-01-13 15:45:44 -0800 | [diff] [blame] | 175 | /* |
| 176 | * We just wake up the flusher thread. It will perform background |
| 177 | * writeback as soon as there is no other work to do. |
| 178 | */ |
Wu Fengguang | 71927e8 | 2011-01-13 15:45:46 -0800 | [diff] [blame] | 179 | trace_writeback_wake_background(bdi); |
Jan Kara | 6585027 | 2011-01-13 15:45:44 -0800 | [diff] [blame] | 180 | spin_lock_bh(&bdi->wb_lock); |
| 181 | bdi_wakeup_flusher(bdi); |
| 182 | spin_unlock_bh(&bdi->wb_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 183 | } |
| 184 | |
| 185 | /* |
Dave Chinner | a66979a | 2011-03-22 22:23:41 +1100 | [diff] [blame] | 186 | * Remove the inode from the writeback list it is on. |
| 187 | */ |
| 188 | void inode_wb_list_del(struct inode *inode) |
| 189 | { |
Christoph Hellwig | f758eea | 2011-04-21 18:19:44 -0600 | [diff] [blame] | 190 | struct backing_dev_info *bdi = inode_to_bdi(inode); |
Dave Chinner | a66979a | 2011-03-22 22:23:41 +1100 | [diff] [blame] | 191 | |
Christoph Hellwig | f758eea | 2011-04-21 18:19:44 -0600 | [diff] [blame] | 192 | spin_lock(&bdi->wb.list_lock); |
| 193 | list_del_init(&inode->i_wb_list); |
| 194 | spin_unlock(&bdi->wb.list_lock); |
| 195 | } |
Dave Chinner | a66979a | 2011-03-22 22:23:41 +1100 | [diff] [blame] | 196 | |
| 197 | /* |
Andrew Morton | 6610a0b | 2007-10-16 23:30:32 -0700 | [diff] [blame] | 198 | * Redirty an inode: set its when-it-was dirtied timestamp and move it to the |
| 199 | * furthest end of its superblock's dirty-inode list. |
| 200 | * |
| 201 | * 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] | 202 | * 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] | 203 | * the case then the inode must have been redirtied while it was being written |
| 204 | * out and we don't reset its dirtied_when. |
| 205 | */ |
Christoph Hellwig | f758eea | 2011-04-21 18:19:44 -0600 | [diff] [blame] | 206 | static void redirty_tail(struct inode *inode, struct bdi_writeback *wb) |
Andrew Morton | 6610a0b | 2007-10-16 23:30:32 -0700 | [diff] [blame] | 207 | { |
Christoph Hellwig | f758eea | 2011-04-21 18:19:44 -0600 | [diff] [blame] | 208 | assert_spin_locked(&wb->list_lock); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 209 | if (!list_empty(&wb->b_dirty)) { |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 210 | struct inode *tail; |
Andrew Morton | 6610a0b | 2007-10-16 23:30:32 -0700 | [diff] [blame] | 211 | |
Nick Piggin | 7ccf19a | 2010-10-21 11:49:30 +1100 | [diff] [blame] | 212 | tail = wb_inode(wb->b_dirty.next); |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 213 | if (time_before(inode->dirtied_when, tail->dirtied_when)) |
Andrew Morton | 6610a0b | 2007-10-16 23:30:32 -0700 | [diff] [blame] | 214 | inode->dirtied_when = jiffies; |
| 215 | } |
Nick Piggin | 7ccf19a | 2010-10-21 11:49:30 +1100 | [diff] [blame] | 216 | list_move(&inode->i_wb_list, &wb->b_dirty); |
Andrew Morton | 6610a0b | 2007-10-16 23:30:32 -0700 | [diff] [blame] | 217 | } |
| 218 | |
| 219 | /* |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 220 | * requeue inode for re-scanning after bdi->b_io list is exhausted. |
Andrew Morton | c986d1e | 2007-10-16 23:30:34 -0700 | [diff] [blame] | 221 | */ |
Christoph Hellwig | f758eea | 2011-04-21 18:19:44 -0600 | [diff] [blame] | 222 | static void requeue_io(struct inode *inode, struct bdi_writeback *wb) |
Andrew Morton | c986d1e | 2007-10-16 23:30:34 -0700 | [diff] [blame] | 223 | { |
Christoph Hellwig | f758eea | 2011-04-21 18:19:44 -0600 | [diff] [blame] | 224 | assert_spin_locked(&wb->list_lock); |
Nick Piggin | 7ccf19a | 2010-10-21 11:49:30 +1100 | [diff] [blame] | 225 | list_move(&inode->i_wb_list, &wb->b_more_io); |
Andrew Morton | c986d1e | 2007-10-16 23:30:34 -0700 | [diff] [blame] | 226 | } |
| 227 | |
Joern Engel | 1c0eeaf | 2007-10-16 23:30:44 -0700 | [diff] [blame] | 228 | static void inode_sync_complete(struct inode *inode) |
| 229 | { |
Jan Kara | 365b94ae | 2012-05-03 14:47:55 +0200 | [diff] [blame] | 230 | inode->i_state &= ~I_SYNC; |
Jan Kara | 4eff96d | 2012-11-26 16:29:51 -0800 | [diff] [blame] | 231 | /* If inode is clean an unused, put it into LRU now... */ |
| 232 | inode_add_lru(inode); |
Jan Kara | 365b94ae | 2012-05-03 14:47:55 +0200 | [diff] [blame] | 233 | /* Waiters must see I_SYNC cleared before being woken up */ |
Joern Engel | 1c0eeaf | 2007-10-16 23:30:44 -0700 | [diff] [blame] | 234 | smp_mb(); |
| 235 | wake_up_bit(&inode->i_state, __I_SYNC); |
| 236 | } |
| 237 | |
Jeff Layton | d2caa3c5 | 2009-04-02 16:56:37 -0700 | [diff] [blame] | 238 | static bool inode_dirtied_after(struct inode *inode, unsigned long t) |
| 239 | { |
| 240 | bool ret = time_after(inode->dirtied_when, t); |
| 241 | #ifndef CONFIG_64BIT |
| 242 | /* |
| 243 | * For inodes being constantly redirtied, dirtied_when can get stuck. |
| 244 | * It _appears_ to be in the future, but is actually in distant past. |
| 245 | * This test is necessary to prevent such wrapped-around relative times |
Jens Axboe | 5b0830c | 2009-09-23 19:37:09 +0200 | [diff] [blame] | 246 | * from permanently stopping the whole bdi writeback. |
Jeff Layton | d2caa3c5 | 2009-04-02 16:56:37 -0700 | [diff] [blame] | 247 | */ |
| 248 | ret = ret && time_before_eq(inode->dirtied_when, jiffies); |
| 249 | #endif |
| 250 | return ret; |
| 251 | } |
| 252 | |
Andrew Morton | c986d1e | 2007-10-16 23:30:34 -0700 | [diff] [blame] | 253 | /* |
Wang Sheng-Hui | 0e2f2b2 | 2012-09-11 08:28:18 +0800 | [diff] [blame] | 254 | * Move expired (dirtied before work->older_than_this) dirty inodes from |
Jan Kara | 697e6fe | 2012-03-09 07:26:22 -0800 | [diff] [blame] | 255 | * @delaying_queue to @dispatch_queue. |
Fengguang Wu | 2c13657 | 2007-10-16 23:30:39 -0700 | [diff] [blame] | 256 | */ |
Wu Fengguang | e84d0a4 | 2011-04-23 12:27:27 -0600 | [diff] [blame] | 257 | static int move_expired_inodes(struct list_head *delaying_queue, |
Fengguang Wu | 2c13657 | 2007-10-16 23:30:39 -0700 | [diff] [blame] | 258 | struct list_head *dispatch_queue, |
Curt Wohlgemuth | ad4e38d | 2011-10-07 21:51:56 -0600 | [diff] [blame] | 259 | struct wb_writeback_work *work) |
Fengguang Wu | 2c13657 | 2007-10-16 23:30:39 -0700 | [diff] [blame] | 260 | { |
Shaohua Li | 5c03449 | 2009-09-24 14:42:33 +0200 | [diff] [blame] | 261 | LIST_HEAD(tmp); |
| 262 | struct list_head *pos, *node; |
Jens Axboe | cf13730 | 2009-09-24 15:12:57 +0200 | [diff] [blame] | 263 | struct super_block *sb = NULL; |
Shaohua Li | 5c03449 | 2009-09-24 14:42:33 +0200 | [diff] [blame] | 264 | struct inode *inode; |
Jens Axboe | cf13730 | 2009-09-24 15:12:57 +0200 | [diff] [blame] | 265 | int do_sb_sort = 0; |
Wu Fengguang | e84d0a4 | 2011-04-23 12:27:27 -0600 | [diff] [blame] | 266 | int moved = 0; |
Shaohua Li | 5c03449 | 2009-09-24 14:42:33 +0200 | [diff] [blame] | 267 | |
Fengguang Wu | 2c13657 | 2007-10-16 23:30:39 -0700 | [diff] [blame] | 268 | while (!list_empty(delaying_queue)) { |
Nick Piggin | 7ccf19a | 2010-10-21 11:49:30 +1100 | [diff] [blame] | 269 | inode = wb_inode(delaying_queue->prev); |
Curt Wohlgemuth | ad4e38d | 2011-10-07 21:51:56 -0600 | [diff] [blame] | 270 | if (work->older_than_this && |
| 271 | inode_dirtied_after(inode, *work->older_than_this)) |
Fengguang Wu | 2c13657 | 2007-10-16 23:30:39 -0700 | [diff] [blame] | 272 | break; |
Jens Axboe | cf13730 | 2009-09-24 15:12:57 +0200 | [diff] [blame] | 273 | if (sb && sb != inode->i_sb) |
| 274 | do_sb_sort = 1; |
| 275 | sb = inode->i_sb; |
Nick Piggin | 7ccf19a | 2010-10-21 11:49:30 +1100 | [diff] [blame] | 276 | list_move(&inode->i_wb_list, &tmp); |
Wu Fengguang | e84d0a4 | 2011-04-23 12:27:27 -0600 | [diff] [blame] | 277 | moved++; |
Shaohua Li | 5c03449 | 2009-09-24 14:42:33 +0200 | [diff] [blame] | 278 | } |
| 279 | |
Jens Axboe | cf13730 | 2009-09-24 15:12:57 +0200 | [diff] [blame] | 280 | /* just one sb in list, splice to dispatch_queue and we're done */ |
| 281 | if (!do_sb_sort) { |
| 282 | list_splice(&tmp, dispatch_queue); |
Wu Fengguang | e84d0a4 | 2011-04-23 12:27:27 -0600 | [diff] [blame] | 283 | goto out; |
Jens Axboe | cf13730 | 2009-09-24 15:12:57 +0200 | [diff] [blame] | 284 | } |
| 285 | |
Shaohua Li | 5c03449 | 2009-09-24 14:42:33 +0200 | [diff] [blame] | 286 | /* Move inodes from one superblock together */ |
| 287 | while (!list_empty(&tmp)) { |
Nick Piggin | 7ccf19a | 2010-10-21 11:49:30 +1100 | [diff] [blame] | 288 | sb = wb_inode(tmp.prev)->i_sb; |
Shaohua Li | 5c03449 | 2009-09-24 14:42:33 +0200 | [diff] [blame] | 289 | list_for_each_prev_safe(pos, node, &tmp) { |
Nick Piggin | 7ccf19a | 2010-10-21 11:49:30 +1100 | [diff] [blame] | 290 | inode = wb_inode(pos); |
Shaohua Li | 5c03449 | 2009-09-24 14:42:33 +0200 | [diff] [blame] | 291 | if (inode->i_sb == sb) |
Nick Piggin | 7ccf19a | 2010-10-21 11:49:30 +1100 | [diff] [blame] | 292 | list_move(&inode->i_wb_list, dispatch_queue); |
Shaohua Li | 5c03449 | 2009-09-24 14:42:33 +0200 | [diff] [blame] | 293 | } |
Fengguang Wu | 2c13657 | 2007-10-16 23:30:39 -0700 | [diff] [blame] | 294 | } |
Wu Fengguang | e84d0a4 | 2011-04-23 12:27:27 -0600 | [diff] [blame] | 295 | out: |
| 296 | return moved; |
Fengguang Wu | 2c13657 | 2007-10-16 23:30:39 -0700 | [diff] [blame] | 297 | } |
| 298 | |
| 299 | /* |
| 300 | * Queue all expired dirty inodes for io, eldest first. |
Wu Fengguang | 4ea879b | 2010-08-11 14:17:42 -0700 | [diff] [blame] | 301 | * Before |
| 302 | * newly dirtied b_dirty b_io b_more_io |
| 303 | * =============> gf edc BA |
| 304 | * After |
| 305 | * newly dirtied b_dirty b_io b_more_io |
| 306 | * =============> g fBAedc |
| 307 | * | |
| 308 | * +--> dequeue for IO |
Fengguang Wu | 2c13657 | 2007-10-16 23:30:39 -0700 | [diff] [blame] | 309 | */ |
Curt Wohlgemuth | ad4e38d | 2011-10-07 21:51:56 -0600 | [diff] [blame] | 310 | static void queue_io(struct bdi_writeback *wb, struct wb_writeback_work *work) |
Fengguang Wu | 2c13657 | 2007-10-16 23:30:39 -0700 | [diff] [blame] | 311 | { |
Wu Fengguang | e84d0a4 | 2011-04-23 12:27:27 -0600 | [diff] [blame] | 312 | int moved; |
Christoph Hellwig | f758eea | 2011-04-21 18:19:44 -0600 | [diff] [blame] | 313 | assert_spin_locked(&wb->list_lock); |
Wu Fengguang | 4ea879b | 2010-08-11 14:17:42 -0700 | [diff] [blame] | 314 | list_splice_init(&wb->b_more_io, &wb->b_io); |
Curt Wohlgemuth | ad4e38d | 2011-10-07 21:51:56 -0600 | [diff] [blame] | 315 | moved = move_expired_inodes(&wb->b_dirty, &wb->b_io, work); |
| 316 | trace_writeback_queue_io(wb, work, moved); |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 317 | } |
| 318 | |
Christoph Hellwig | a9185b4 | 2010-03-05 09:21:37 +0100 | [diff] [blame] | 319 | static int write_inode(struct inode *inode, struct writeback_control *wbc) |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 320 | { |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 321 | if (inode->i_sb->s_op->write_inode && !is_bad_inode(inode)) |
Christoph Hellwig | a9185b4 | 2010-03-05 09:21:37 +0100 | [diff] [blame] | 322 | return inode->i_sb->s_op->write_inode(inode, wbc); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 323 | return 0; |
Fengguang Wu | 2c13657 | 2007-10-16 23:30:39 -0700 | [diff] [blame] | 324 | } |
| 325 | |
| 326 | /* |
Jan Kara | 169ebd9 | 2012-05-03 14:48:03 +0200 | [diff] [blame] | 327 | * Wait for writeback on an inode to complete. Called with i_lock held. |
| 328 | * Caller must make sure inode cannot go away when we drop i_lock. |
Christoph Hellwig | 01c0319 | 2009-06-08 13:35:40 +0200 | [diff] [blame] | 329 | */ |
Jan Kara | 169ebd9 | 2012-05-03 14:48:03 +0200 | [diff] [blame] | 330 | static void __inode_wait_for_writeback(struct inode *inode) |
| 331 | __releases(inode->i_lock) |
| 332 | __acquires(inode->i_lock) |
Christoph Hellwig | 01c0319 | 2009-06-08 13:35:40 +0200 | [diff] [blame] | 333 | { |
| 334 | DEFINE_WAIT_BIT(wq, &inode->i_state, __I_SYNC); |
| 335 | wait_queue_head_t *wqh; |
| 336 | |
| 337 | wqh = bit_waitqueue(&inode->i_state, __I_SYNC); |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 338 | while (inode->i_state & I_SYNC) { |
| 339 | spin_unlock(&inode->i_lock); |
Christoph Hellwig | 01c0319 | 2009-06-08 13:35:40 +0200 | [diff] [blame] | 340 | __wait_on_bit(wqh, &wq, inode_wait, TASK_UNINTERRUPTIBLE); |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 341 | spin_lock(&inode->i_lock); |
Richard Kennedy | 58a9d3d8 | 2010-05-24 14:32:38 -0700 | [diff] [blame] | 342 | } |
Christoph Hellwig | 01c0319 | 2009-06-08 13:35:40 +0200 | [diff] [blame] | 343 | } |
| 344 | |
| 345 | /* |
Jan Kara | 169ebd9 | 2012-05-03 14:48:03 +0200 | [diff] [blame] | 346 | * Wait for writeback on an inode to complete. Caller must have inode pinned. |
| 347 | */ |
| 348 | void inode_wait_for_writeback(struct inode *inode) |
| 349 | { |
| 350 | spin_lock(&inode->i_lock); |
| 351 | __inode_wait_for_writeback(inode); |
| 352 | spin_unlock(&inode->i_lock); |
| 353 | } |
| 354 | |
| 355 | /* |
| 356 | * Sleep until I_SYNC is cleared. This function must be called with i_lock |
| 357 | * held and drops it. It is aimed for callers not holding any inode reference |
| 358 | * so once i_lock is dropped, inode can go away. |
| 359 | */ |
| 360 | static void inode_sleep_on_writeback(struct inode *inode) |
| 361 | __releases(inode->i_lock) |
| 362 | { |
| 363 | DEFINE_WAIT(wait); |
| 364 | wait_queue_head_t *wqh = bit_waitqueue(&inode->i_state, __I_SYNC); |
| 365 | int sleep; |
| 366 | |
| 367 | prepare_to_wait(wqh, &wait, TASK_UNINTERRUPTIBLE); |
| 368 | sleep = inode->i_state & I_SYNC; |
| 369 | spin_unlock(&inode->i_lock); |
| 370 | if (sleep) |
| 371 | schedule(); |
| 372 | finish_wait(wqh, &wait); |
| 373 | } |
| 374 | |
| 375 | /* |
Jan Kara | ccb26b5 | 2012-05-03 14:47:58 +0200 | [diff] [blame] | 376 | * Find proper writeback list for the inode depending on its current state and |
| 377 | * possibly also change of its state while we were doing writeback. Here we |
| 378 | * handle things such as livelock prevention or fairness of writeback among |
| 379 | * inodes. This function can be called only by flusher thread - noone else |
| 380 | * processes all inodes in writeback lists and requeueing inodes behind flusher |
| 381 | * thread's back can have unexpected consequences. |
| 382 | */ |
| 383 | static void requeue_inode(struct inode *inode, struct bdi_writeback *wb, |
| 384 | struct writeback_control *wbc) |
| 385 | { |
| 386 | if (inode->i_state & I_FREEING) |
| 387 | return; |
| 388 | |
| 389 | /* |
| 390 | * Sync livelock prevention. Each inode is tagged and synced in one |
| 391 | * shot. If still dirty, it will be redirty_tail()'ed below. Update |
| 392 | * the dirty time to prevent enqueue and sync it again. |
| 393 | */ |
| 394 | if ((inode->i_state & I_DIRTY) && |
| 395 | (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)) |
| 396 | inode->dirtied_when = jiffies; |
| 397 | |
Jan Kara | 4f8ad65 | 2012-05-03 14:48:00 +0200 | [diff] [blame] | 398 | if (wbc->pages_skipped) { |
| 399 | /* |
| 400 | * writeback is not making progress due to locked |
| 401 | * buffers. Skip this inode for now. |
| 402 | */ |
| 403 | redirty_tail(inode, wb); |
| 404 | return; |
| 405 | } |
| 406 | |
Jan Kara | ccb26b5 | 2012-05-03 14:47:58 +0200 | [diff] [blame] | 407 | if (mapping_tagged(inode->i_mapping, PAGECACHE_TAG_DIRTY)) { |
| 408 | /* |
| 409 | * We didn't write back all the pages. nfs_writepages() |
| 410 | * sometimes bales out without doing anything. |
| 411 | */ |
| 412 | if (wbc->nr_to_write <= 0) { |
| 413 | /* Slice used up. Queue for next turn. */ |
| 414 | requeue_io(inode, wb); |
| 415 | } else { |
| 416 | /* |
| 417 | * Writeback blocked by something other than |
| 418 | * congestion. Delay the inode for some time to |
| 419 | * avoid spinning on the CPU (100% iowait) |
| 420 | * retrying writeback of the dirty page/inode |
| 421 | * that cannot be performed immediately. |
| 422 | */ |
| 423 | redirty_tail(inode, wb); |
| 424 | } |
| 425 | } else if (inode->i_state & I_DIRTY) { |
| 426 | /* |
| 427 | * Filesystems can dirty the inode during writeback operations, |
| 428 | * such as delayed allocation during submission or metadata |
| 429 | * updates after data IO completion. |
| 430 | */ |
| 431 | redirty_tail(inode, wb); |
| 432 | } else { |
| 433 | /* The inode is clean. Remove from writeback lists. */ |
| 434 | list_del_init(&inode->i_wb_list); |
| 435 | } |
| 436 | } |
| 437 | |
| 438 | /* |
Jan Kara | 4f8ad65 | 2012-05-03 14:48:00 +0200 | [diff] [blame] | 439 | * Write out an inode and its dirty pages. Do not update the writeback list |
| 440 | * linkage. That is left to the caller. The caller is also responsible for |
| 441 | * setting I_SYNC flag and calling inode_sync_complete() to clear it. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 442 | */ |
| 443 | static int |
Yan Hong | cd8ed2a | 2012-10-08 16:33:45 -0700 | [diff] [blame] | 444 | __writeback_single_inode(struct inode *inode, struct writeback_control *wbc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 445 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 446 | struct address_space *mapping = inode->i_mapping; |
Wu Fengguang | 251d6a4 | 2010-12-01 17:33:37 -0600 | [diff] [blame] | 447 | long nr_to_write = wbc->nr_to_write; |
Christoph Hellwig | 01c0319 | 2009-06-08 13:35:40 +0200 | [diff] [blame] | 448 | unsigned dirty; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 449 | int ret; |
| 450 | |
Jan Kara | 4f8ad65 | 2012-05-03 14:48:00 +0200 | [diff] [blame] | 451 | WARN_ON(!(inode->i_state & I_SYNC)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 452 | |
| 453 | ret = do_writepages(mapping, wbc); |
| 454 | |
Christoph Hellwig | 26821ed | 2010-03-05 09:21:21 +0100 | [diff] [blame] | 455 | /* |
| 456 | * Make sure to wait on the data before writing out the metadata. |
| 457 | * This is important for filesystems that modify metadata on data |
| 458 | * I/O completion. |
| 459 | */ |
Christoph Hellwig | a9185b4 | 2010-03-05 09:21:37 +0100 | [diff] [blame] | 460 | if (wbc->sync_mode == WB_SYNC_ALL) { |
Christoph Hellwig | 26821ed | 2010-03-05 09:21:21 +0100 | [diff] [blame] | 461 | int err = filemap_fdatawait(mapping); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 462 | if (ret == 0) |
| 463 | ret = err; |
| 464 | } |
| 465 | |
Dmitry Monakhov | 5547e8a | 2010-05-07 13:35:44 +0400 | [diff] [blame] | 466 | /* |
| 467 | * Some filesystems may redirty the inode during the writeback |
| 468 | * due to delalloc, clear dirty metadata flags right before |
| 469 | * write_inode() |
| 470 | */ |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 471 | spin_lock(&inode->i_lock); |
Jan Kara | 6290be1 | 2012-05-03 14:47:57 +0200 | [diff] [blame] | 472 | /* Clear I_DIRTY_PAGES if we've written out all dirty pages */ |
| 473 | if (!mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) |
| 474 | inode->i_state &= ~I_DIRTY_PAGES; |
Dmitry Monakhov | 5547e8a | 2010-05-07 13:35:44 +0400 | [diff] [blame] | 475 | dirty = inode->i_state & I_DIRTY; |
| 476 | inode->i_state &= ~(I_DIRTY_SYNC | I_DIRTY_DATASYNC); |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 477 | spin_unlock(&inode->i_lock); |
Christoph Hellwig | 26821ed | 2010-03-05 09:21:21 +0100 | [diff] [blame] | 478 | /* Don't write the inode if only I_DIRTY_PAGES was set */ |
| 479 | if (dirty & (I_DIRTY_SYNC | I_DIRTY_DATASYNC)) { |
Christoph Hellwig | a9185b4 | 2010-03-05 09:21:37 +0100 | [diff] [blame] | 480 | int err = write_inode(inode, wbc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 481 | if (ret == 0) |
| 482 | ret = err; |
| 483 | } |
Jan Kara | 4f8ad65 | 2012-05-03 14:48:00 +0200 | [diff] [blame] | 484 | trace_writeback_single_inode(inode, wbc, nr_to_write); |
| 485 | return ret; |
| 486 | } |
| 487 | |
| 488 | /* |
| 489 | * Write out an inode's dirty pages. Either the caller has an active reference |
| 490 | * on the inode or the inode has I_WILL_FREE set. |
| 491 | * |
| 492 | * This function is designed to be called for writing back one inode which |
| 493 | * we go e.g. from filesystem. Flusher thread uses __writeback_single_inode() |
| 494 | * and does more profound writeback list handling in writeback_sb_inodes(). |
| 495 | */ |
| 496 | static int |
| 497 | writeback_single_inode(struct inode *inode, struct bdi_writeback *wb, |
| 498 | struct writeback_control *wbc) |
| 499 | { |
| 500 | int ret = 0; |
| 501 | |
| 502 | spin_lock(&inode->i_lock); |
| 503 | if (!atomic_read(&inode->i_count)) |
| 504 | WARN_ON(!(inode->i_state & (I_WILL_FREE|I_FREEING))); |
| 505 | else |
| 506 | WARN_ON(inode->i_state & I_WILL_FREE); |
| 507 | |
| 508 | if (inode->i_state & I_SYNC) { |
| 509 | if (wbc->sync_mode != WB_SYNC_ALL) |
| 510 | goto out; |
| 511 | /* |
Jan Kara | 169ebd9 | 2012-05-03 14:48:03 +0200 | [diff] [blame] | 512 | * It's a data-integrity sync. We must wait. Since callers hold |
| 513 | * inode reference or inode has I_WILL_FREE set, it cannot go |
| 514 | * away under us. |
Jan Kara | 4f8ad65 | 2012-05-03 14:48:00 +0200 | [diff] [blame] | 515 | */ |
Jan Kara | 169ebd9 | 2012-05-03 14:48:03 +0200 | [diff] [blame] | 516 | __inode_wait_for_writeback(inode); |
Jan Kara | 4f8ad65 | 2012-05-03 14:48:00 +0200 | [diff] [blame] | 517 | } |
| 518 | WARN_ON(inode->i_state & I_SYNC); |
| 519 | /* |
| 520 | * Skip inode if it is clean. We don't want to mess with writeback |
| 521 | * lists in this function since flusher thread may be doing for example |
| 522 | * sync in parallel and if we move the inode, it could get skipped. So |
| 523 | * here we make sure inode is on some writeback list and leave it there |
| 524 | * unless we have completely cleaned the inode. |
| 525 | */ |
| 526 | if (!(inode->i_state & I_DIRTY)) |
| 527 | goto out; |
| 528 | inode->i_state |= I_SYNC; |
| 529 | spin_unlock(&inode->i_lock); |
| 530 | |
Yan Hong | cd8ed2a | 2012-10-08 16:33:45 -0700 | [diff] [blame] | 531 | ret = __writeback_single_inode(inode, wbc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 532 | |
Christoph Hellwig | f758eea | 2011-04-21 18:19:44 -0600 | [diff] [blame] | 533 | spin_lock(&wb->list_lock); |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 534 | spin_lock(&inode->i_lock); |
Jan Kara | 4f8ad65 | 2012-05-03 14:48:00 +0200 | [diff] [blame] | 535 | /* |
| 536 | * If inode is clean, remove it from writeback lists. Otherwise don't |
| 537 | * touch it. See comment above for explanation. |
| 538 | */ |
| 539 | if (!(inode->i_state & I_DIRTY)) |
| 540 | list_del_init(&inode->i_wb_list); |
| 541 | spin_unlock(&wb->list_lock); |
Joern Engel | 1c0eeaf | 2007-10-16 23:30:44 -0700 | [diff] [blame] | 542 | inode_sync_complete(inode); |
Jan Kara | 4f8ad65 | 2012-05-03 14:48:00 +0200 | [diff] [blame] | 543 | out: |
| 544 | spin_unlock(&inode->i_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 545 | return ret; |
| 546 | } |
| 547 | |
Wu Fengguang | 1a12d8b | 2010-08-29 13:28:09 -0600 | [diff] [blame] | 548 | static long writeback_chunk_size(struct backing_dev_info *bdi, |
| 549 | struct wb_writeback_work *work) |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 550 | { |
| 551 | long pages; |
| 552 | |
| 553 | /* |
| 554 | * WB_SYNC_ALL mode does livelock avoidance by syncing dirty |
| 555 | * inodes/pages in one big loop. Setting wbc.nr_to_write=LONG_MAX |
| 556 | * here avoids calling into writeback_inodes_wb() more than once. |
| 557 | * |
| 558 | * The intended call sequence for WB_SYNC_ALL writeback is: |
| 559 | * |
| 560 | * wb_writeback() |
| 561 | * writeback_sb_inodes() <== called only once |
| 562 | * write_cache_pages() <== called once for each inode |
| 563 | * (quickly) tag currently dirty pages |
| 564 | * (maybe slowly) sync all tagged pages |
| 565 | */ |
| 566 | if (work->sync_mode == WB_SYNC_ALL || work->tagged_writepages) |
| 567 | pages = LONG_MAX; |
Wu Fengguang | 1a12d8b | 2010-08-29 13:28:09 -0600 | [diff] [blame] | 568 | else { |
| 569 | pages = min(bdi->avg_write_bandwidth / 2, |
| 570 | global_dirty_limit / DIRTY_SCOPE); |
| 571 | pages = min(pages, work->nr_pages); |
| 572 | pages = round_down(pages + MIN_WRITEBACK_PAGES, |
| 573 | MIN_WRITEBACK_PAGES); |
| 574 | } |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 575 | |
| 576 | return pages; |
| 577 | } |
| 578 | |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 579 | /* |
Edward Shishkin | f11c9c5 | 2010-03-11 14:09:47 -0800 | [diff] [blame] | 580 | * Write a portion of b_io inodes which belong to @sb. |
Christoph Hellwig | edadfb1 | 2010-06-10 12:07:54 +0200 | [diff] [blame] | 581 | * |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 582 | * Return the number of pages and/or inodes written. |
Edward Shishkin | f11c9c5 | 2010-03-11 14:09:47 -0800 | [diff] [blame] | 583 | */ |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 584 | static long writeback_sb_inodes(struct super_block *sb, |
| 585 | struct bdi_writeback *wb, |
| 586 | struct wb_writeback_work *work) |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 587 | { |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 588 | struct writeback_control wbc = { |
| 589 | .sync_mode = work->sync_mode, |
| 590 | .tagged_writepages = work->tagged_writepages, |
| 591 | .for_kupdate = work->for_kupdate, |
| 592 | .for_background = work->for_background, |
| 593 | .range_cyclic = work->range_cyclic, |
| 594 | .range_start = 0, |
| 595 | .range_end = LLONG_MAX, |
| 596 | }; |
| 597 | unsigned long start_time = jiffies; |
| 598 | long write_chunk; |
| 599 | long wrote = 0; /* count both pages and inodes */ |
| 600 | |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 601 | while (!list_empty(&wb->b_io)) { |
Nick Piggin | 7ccf19a | 2010-10-21 11:49:30 +1100 | [diff] [blame] | 602 | struct inode *inode = wb_inode(wb->b_io.prev); |
Christoph Hellwig | edadfb1 | 2010-06-10 12:07:54 +0200 | [diff] [blame] | 603 | |
| 604 | if (inode->i_sb != sb) { |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 605 | if (work->sb) { |
Christoph Hellwig | edadfb1 | 2010-06-10 12:07:54 +0200 | [diff] [blame] | 606 | /* |
| 607 | * We only want to write back data for this |
| 608 | * superblock, move all inodes not belonging |
| 609 | * to it back onto the dirty list. |
| 610 | */ |
Christoph Hellwig | f758eea | 2011-04-21 18:19:44 -0600 | [diff] [blame] | 611 | redirty_tail(inode, wb); |
Christoph Hellwig | edadfb1 | 2010-06-10 12:07:54 +0200 | [diff] [blame] | 612 | continue; |
| 613 | } |
| 614 | |
| 615 | /* |
| 616 | * The inode belongs to a different superblock. |
| 617 | * Bounce back to the caller to unpin this and |
| 618 | * pin the next superblock. |
| 619 | */ |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 620 | break; |
Christoph Hellwig | edadfb1 | 2010-06-10 12:07:54 +0200 | [diff] [blame] | 621 | } |
| 622 | |
Christoph Hellwig | 9843b76a | 2010-10-24 19:40:46 +0200 | [diff] [blame] | 623 | /* |
Wanpeng Li | 331cbde | 2012-06-09 11:10:55 +0800 | [diff] [blame] | 624 | * Don't bother with new inodes or inodes being freed, first |
| 625 | * kind does not need periodic writeout yet, and for the latter |
Christoph Hellwig | 9843b76a | 2010-10-24 19:40:46 +0200 | [diff] [blame] | 626 | * kind writeout is handled by the freer. |
| 627 | */ |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 628 | spin_lock(&inode->i_lock); |
Christoph Hellwig | 9843b76a | 2010-10-24 19:40:46 +0200 | [diff] [blame] | 629 | if (inode->i_state & (I_NEW | I_FREEING | I_WILL_FREE)) { |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 630 | spin_unlock(&inode->i_lock); |
Wu Fengguang | fcc5c22 | 2011-07-11 23:08:50 -0700 | [diff] [blame] | 631 | redirty_tail(inode, wb); |
Nick Piggin | 7ef0d73 | 2009-03-12 14:31:38 -0700 | [diff] [blame] | 632 | continue; |
| 633 | } |
Jan Kara | cc1676d | 2012-05-03 14:47:56 +0200 | [diff] [blame] | 634 | if ((inode->i_state & I_SYNC) && wbc.sync_mode != WB_SYNC_ALL) { |
| 635 | /* |
| 636 | * If this inode is locked for writeback and we are not |
| 637 | * doing writeback-for-data-integrity, move it to |
| 638 | * b_more_io so that writeback can proceed with the |
| 639 | * other inodes on s_io. |
| 640 | * |
| 641 | * We'll have another go at writing back this inode |
| 642 | * when we completed a full scan of b_io. |
| 643 | */ |
| 644 | spin_unlock(&inode->i_lock); |
| 645 | requeue_io(inode, wb); |
| 646 | trace_writeback_sb_inodes_requeue(inode); |
| 647 | continue; |
| 648 | } |
Jan Kara | f0d07b7 | 2012-05-03 14:47:59 +0200 | [diff] [blame] | 649 | spin_unlock(&wb->list_lock); |
| 650 | |
Jan Kara | 4f8ad65 | 2012-05-03 14:48:00 +0200 | [diff] [blame] | 651 | /* |
| 652 | * We already requeued the inode if it had I_SYNC set and we |
| 653 | * are doing WB_SYNC_NONE writeback. So this catches only the |
| 654 | * WB_SYNC_ALL case. |
| 655 | */ |
Jan Kara | 169ebd9 | 2012-05-03 14:48:03 +0200 | [diff] [blame] | 656 | if (inode->i_state & I_SYNC) { |
| 657 | /* Wait for I_SYNC. This function drops i_lock... */ |
| 658 | inode_sleep_on_writeback(inode); |
| 659 | /* Inode may be gone, start again */ |
Jan Kara | ead188f9 | 2012-06-08 17:07:36 +0200 | [diff] [blame] | 660 | spin_lock(&wb->list_lock); |
Jan Kara | 169ebd9 | 2012-05-03 14:48:03 +0200 | [diff] [blame] | 661 | continue; |
| 662 | } |
Jan Kara | 4f8ad65 | 2012-05-03 14:48:00 +0200 | [diff] [blame] | 663 | inode->i_state |= I_SYNC; |
| 664 | spin_unlock(&inode->i_lock); |
Jan Kara | 169ebd9 | 2012-05-03 14:48:03 +0200 | [diff] [blame] | 665 | |
Wu Fengguang | 1a12d8b | 2010-08-29 13:28:09 -0600 | [diff] [blame] | 666 | write_chunk = writeback_chunk_size(wb->bdi, work); |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 667 | wbc.nr_to_write = write_chunk; |
| 668 | wbc.pages_skipped = 0; |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 669 | |
Jan Kara | 169ebd9 | 2012-05-03 14:48:03 +0200 | [diff] [blame] | 670 | /* |
| 671 | * We use I_SYNC to pin the inode in memory. While it is set |
| 672 | * evict_inode() will wait so the inode cannot be freed. |
| 673 | */ |
Yan Hong | cd8ed2a | 2012-10-08 16:33:45 -0700 | [diff] [blame] | 674 | __writeback_single_inode(inode, &wbc); |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 675 | |
| 676 | work->nr_pages -= write_chunk - wbc.nr_to_write; |
| 677 | wrote += write_chunk - wbc.nr_to_write; |
Jan Kara | 4f8ad65 | 2012-05-03 14:48:00 +0200 | [diff] [blame] | 678 | spin_lock(&wb->list_lock); |
| 679 | spin_lock(&inode->i_lock); |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 680 | if (!(inode->i_state & I_DIRTY)) |
| 681 | wrote++; |
Jan Kara | 4f8ad65 | 2012-05-03 14:48:00 +0200 | [diff] [blame] | 682 | requeue_inode(inode, wb, &wbc); |
| 683 | inode_sync_complete(inode); |
Dave Chinner | 0f1b1fd | 2011-03-22 22:23:43 +1100 | [diff] [blame] | 684 | spin_unlock(&inode->i_lock); |
Jan Kara | 169ebd9 | 2012-05-03 14:48:03 +0200 | [diff] [blame] | 685 | cond_resched_lock(&wb->list_lock); |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 686 | /* |
| 687 | * bail out to wb_writeback() often enough to check |
| 688 | * background threshold and other termination conditions. |
| 689 | */ |
| 690 | if (wrote) { |
| 691 | if (time_is_before_jiffies(start_time + HZ / 10UL)) |
| 692 | break; |
| 693 | if (work->nr_pages <= 0) |
| 694 | break; |
Fengguang Wu | 8bc3be2 | 2008-02-04 22:29:36 -0800 | [diff] [blame] | 695 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 696 | } |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 697 | return wrote; |
Edward Shishkin | f11c9c5 | 2010-03-11 14:09:47 -0800 | [diff] [blame] | 698 | } |
Nick Piggin | 38f2197 | 2009-01-06 14:40:25 -0800 | [diff] [blame] | 699 | |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 700 | static long __writeback_inodes_wb(struct bdi_writeback *wb, |
| 701 | struct wb_writeback_work *work) |
Edward Shishkin | f11c9c5 | 2010-03-11 14:09:47 -0800 | [diff] [blame] | 702 | { |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 703 | unsigned long start_time = jiffies; |
| 704 | long wrote = 0; |
Edward Shishkin | f11c9c5 | 2010-03-11 14:09:47 -0800 | [diff] [blame] | 705 | |
| 706 | while (!list_empty(&wb->b_io)) { |
Nick Piggin | 7ccf19a | 2010-10-21 11:49:30 +1100 | [diff] [blame] | 707 | struct inode *inode = wb_inode(wb->b_io.prev); |
Edward Shishkin | f11c9c5 | 2010-03-11 14:09:47 -0800 | [diff] [blame] | 708 | struct super_block *sb = inode->i_sb; |
Edward Shishkin | f11c9c5 | 2010-03-11 14:09:47 -0800 | [diff] [blame] | 709 | |
Dave Chinner | 12ad3ab | 2011-07-08 14:14:41 +1000 | [diff] [blame] | 710 | if (!grab_super_passive(sb)) { |
Wu Fengguang | 0e99581 | 2011-07-29 22:14:35 -0600 | [diff] [blame] | 711 | /* |
| 712 | * grab_super_passive() may fail consistently due to |
| 713 | * s_umount being grabbed by someone else. Don't use |
| 714 | * requeue_io() to avoid busy retrying the inode/sb. |
| 715 | */ |
| 716 | redirty_tail(inode, wb); |
Christoph Hellwig | edadfb1 | 2010-06-10 12:07:54 +0200 | [diff] [blame] | 717 | continue; |
Edward Shishkin | f11c9c5 | 2010-03-11 14:09:47 -0800 | [diff] [blame] | 718 | } |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 719 | wrote += writeback_sb_inodes(sb, wb, work); |
Christoph Hellwig | edadfb1 | 2010-06-10 12:07:54 +0200 | [diff] [blame] | 720 | drop_super(sb); |
Edward Shishkin | f11c9c5 | 2010-03-11 14:09:47 -0800 | [diff] [blame] | 721 | |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 722 | /* refer to the same tests at the end of writeback_sb_inodes */ |
| 723 | if (wrote) { |
| 724 | if (time_is_before_jiffies(start_time + HZ / 10UL)) |
| 725 | break; |
| 726 | if (work->nr_pages <= 0) |
| 727 | break; |
| 728 | } |
Edward Shishkin | f11c9c5 | 2010-03-11 14:09:47 -0800 | [diff] [blame] | 729 | } |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 730 | /* Leave any unwritten inodes on b_io */ |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 731 | return wrote; |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 732 | } |
| 733 | |
Curt Wohlgemuth | 0e175a1 | 2011-10-07 21:54:10 -0600 | [diff] [blame] | 734 | long writeback_inodes_wb(struct bdi_writeback *wb, long nr_pages, |
| 735 | enum wb_reason reason) |
Christoph Hellwig | edadfb1 | 2010-06-10 12:07:54 +0200 | [diff] [blame] | 736 | { |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 737 | struct wb_writeback_work work = { |
| 738 | .nr_pages = nr_pages, |
| 739 | .sync_mode = WB_SYNC_NONE, |
| 740 | .range_cyclic = 1, |
Curt Wohlgemuth | 0e175a1 | 2011-10-07 21:54:10 -0600 | [diff] [blame] | 741 | .reason = reason, |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 742 | }; |
Christoph Hellwig | edadfb1 | 2010-06-10 12:07:54 +0200 | [diff] [blame] | 743 | |
Christoph Hellwig | f758eea | 2011-04-21 18:19:44 -0600 | [diff] [blame] | 744 | spin_lock(&wb->list_lock); |
Wu Fengguang | 424b351 | 2010-07-21 20:11:53 -0600 | [diff] [blame] | 745 | if (list_empty(&wb->b_io)) |
Curt Wohlgemuth | ad4e38d | 2011-10-07 21:51:56 -0600 | [diff] [blame] | 746 | queue_io(wb, &work); |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 747 | __writeback_inodes_wb(wb, &work); |
Christoph Hellwig | f758eea | 2011-04-21 18:19:44 -0600 | [diff] [blame] | 748 | spin_unlock(&wb->list_lock); |
Christoph Hellwig | edadfb1 | 2010-06-10 12:07:54 +0200 | [diff] [blame] | 749 | |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 750 | return nr_pages - work.nr_pages; |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 751 | } |
| 752 | |
Wu Fengguang | b00949a | 2010-11-18 14:38:33 -0600 | [diff] [blame] | 753 | static bool over_bground_thresh(struct backing_dev_info *bdi) |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 754 | { |
| 755 | unsigned long background_thresh, dirty_thresh; |
| 756 | |
Wu Fengguang | 16c4042 | 2010-08-11 14:17:39 -0700 | [diff] [blame] | 757 | global_dirty_limits(&background_thresh, &dirty_thresh); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 758 | |
Wu Fengguang | b00949a | 2010-11-18 14:38:33 -0600 | [diff] [blame] | 759 | if (global_page_state(NR_FILE_DIRTY) + |
| 760 | global_page_state(NR_UNSTABLE_NFS) > background_thresh) |
| 761 | return true; |
| 762 | |
| 763 | if (bdi_stat(bdi, BDI_RECLAIMABLE) > |
| 764 | bdi_dirty_limit(bdi, background_thresh)) |
| 765 | return true; |
| 766 | |
| 767 | return false; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 768 | } |
| 769 | |
| 770 | /* |
Wu Fengguang | e98be2d | 2010-08-29 11:22:30 -0600 | [diff] [blame] | 771 | * Called under wb->list_lock. If there are multiple wb per bdi, |
| 772 | * only the flusher working on the first wb should do it. |
| 773 | */ |
| 774 | static void wb_update_bandwidth(struct bdi_writeback *wb, |
| 775 | unsigned long start_time) |
| 776 | { |
Wu Fengguang | af6a311 | 2011-10-03 20:46:17 -0600 | [diff] [blame] | 777 | __bdi_update_bandwidth(wb->bdi, 0, 0, 0, 0, 0, start_time); |
Wu Fengguang | e98be2d | 2010-08-29 11:22:30 -0600 | [diff] [blame] | 778 | } |
| 779 | |
| 780 | /* |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 781 | * Explicit flushing or periodic writeback of "old" data. |
| 782 | * |
| 783 | * Define "old": the first time one of an inode's pages is dirtied, we mark the |
| 784 | * dirtying-time in the inode's address_space. So this periodic writeback code |
| 785 | * just walks the superblock inode list, writing back any inodes which are |
| 786 | * older than a specific point in time. |
| 787 | * |
| 788 | * Try to run once per dirty_writeback_interval. But if a writeback event |
| 789 | * takes longer than a dirty_writeback_interval interval, then leave a |
| 790 | * one-second gap. |
| 791 | * |
| 792 | * older_than_this takes precedence over nr_to_write. So we'll only write back |
| 793 | * all dirty pages if they are all attached to "old" mappings. |
| 794 | */ |
Jens Axboe | c4a77a6 | 2009-09-16 15:18:25 +0200 | [diff] [blame] | 795 | static long wb_writeback(struct bdi_writeback *wb, |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 796 | struct wb_writeback_work *work) |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 797 | { |
Wu Fengguang | e98be2d | 2010-08-29 11:22:30 -0600 | [diff] [blame] | 798 | unsigned long wb_start = jiffies; |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 799 | long nr_pages = work->nr_pages; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 800 | unsigned long oldest_jif; |
Jan Kara | a5989bd | 2009-09-16 19:22:48 +0200 | [diff] [blame] | 801 | struct inode *inode; |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 802 | long progress; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 803 | |
Wu Fengguang | e185dda | 2011-04-23 11:26:07 -0600 | [diff] [blame] | 804 | oldest_jif = jiffies; |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 805 | work->older_than_this = &oldest_jif; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 806 | |
Wu Fengguang | e8dfc30 | 2011-04-21 12:06:32 -0600 | [diff] [blame] | 807 | spin_lock(&wb->list_lock); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 808 | for (;;) { |
| 809 | /* |
Wu Fengguang | d3ddec7 | 2009-09-23 20:33:40 +0800 | [diff] [blame] | 810 | * Stop writeback when nr_pages has been consumed |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 811 | */ |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 812 | if (work->nr_pages <= 0) |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 813 | break; |
| 814 | |
| 815 | /* |
Jan Kara | aa373cf | 2011-01-13 15:45:47 -0800 | [diff] [blame] | 816 | * Background writeout and kupdate-style writeback may |
| 817 | * run forever. Stop them if there is other work to do |
| 818 | * so that e.g. sync can proceed. They'll be restarted |
| 819 | * after the other works are all done. |
| 820 | */ |
| 821 | if ((work->for_background || work->for_kupdate) && |
| 822 | !list_empty(&wb->bdi->work_list)) |
| 823 | break; |
| 824 | |
| 825 | /* |
Wu Fengguang | d3ddec7 | 2009-09-23 20:33:40 +0800 | [diff] [blame] | 826 | * For background writeout, stop when we are below the |
| 827 | * background dirty threshold |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 828 | */ |
Wu Fengguang | b00949a | 2010-11-18 14:38:33 -0600 | [diff] [blame] | 829 | if (work->for_background && !over_bground_thresh(wb->bdi)) |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 830 | break; |
| 831 | |
Jan Kara | 1bc36b6 | 2011-10-19 11:44:41 +0200 | [diff] [blame] | 832 | /* |
| 833 | * Kupdate and background works are special and we want to |
| 834 | * include all inodes that need writing. Livelock avoidance is |
| 835 | * handled by these works yielding to any other work so we are |
| 836 | * safe. |
| 837 | */ |
Wu Fengguang | ba9aa839 | 2010-07-21 20:32:30 -0600 | [diff] [blame] | 838 | if (work->for_kupdate) { |
| 839 | oldest_jif = jiffies - |
| 840 | msecs_to_jiffies(dirty_expire_interval * 10); |
Jan Kara | 1bc36b6 | 2011-10-19 11:44:41 +0200 | [diff] [blame] | 841 | } else if (work->for_background) |
| 842 | oldest_jif = jiffies; |
Dave Chinner | 028c2dd | 2010-07-07 13:24:07 +1000 | [diff] [blame] | 843 | |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 844 | trace_writeback_start(wb->bdi, work); |
Wu Fengguang | e8dfc30 | 2011-04-21 12:06:32 -0600 | [diff] [blame] | 845 | if (list_empty(&wb->b_io)) |
Curt Wohlgemuth | ad4e38d | 2011-10-07 21:51:56 -0600 | [diff] [blame] | 846 | queue_io(wb, work); |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 847 | if (work->sb) |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 848 | progress = writeback_sb_inodes(work->sb, wb, work); |
Christoph Hellwig | edadfb1 | 2010-06-10 12:07:54 +0200 | [diff] [blame] | 849 | else |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 850 | progress = __writeback_inodes_wb(wb, work); |
| 851 | trace_writeback_written(wb->bdi, work); |
Dave Chinner | 028c2dd | 2010-07-07 13:24:07 +1000 | [diff] [blame] | 852 | |
Wu Fengguang | e98be2d | 2010-08-29 11:22:30 -0600 | [diff] [blame] | 853 | wb_update_bandwidth(wb, wb_start); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 854 | |
| 855 | /* |
Jens Axboe | 71fd05a | 2009-09-23 19:32:26 +0200 | [diff] [blame] | 856 | * Did we write something? Try for more |
Wu Fengguang | e6fb6da | 2010-07-22 10:23:44 -0600 | [diff] [blame] | 857 | * |
| 858 | * Dirty inodes are moved to b_io for writeback in batches. |
| 859 | * The completion of the current batch does not necessarily |
| 860 | * mean the overall work is done. So we keep looping as long |
| 861 | * as made some progress on cleaning pages or inodes. |
Jens Axboe | 71fd05a | 2009-09-23 19:32:26 +0200 | [diff] [blame] | 862 | */ |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 863 | if (progress) |
Jens Axboe | 71fd05a | 2009-09-23 19:32:26 +0200 | [diff] [blame] | 864 | continue; |
| 865 | /* |
Wu Fengguang | e6fb6da | 2010-07-22 10:23:44 -0600 | [diff] [blame] | 866 | * No more inodes for IO, bail |
Jens Axboe | 71fd05a | 2009-09-23 19:32:26 +0200 | [diff] [blame] | 867 | */ |
Wu Fengguang | b7a2441 | 2010-07-21 22:19:51 -0600 | [diff] [blame] | 868 | if (list_empty(&wb->b_more_io)) |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 869 | break; |
| 870 | /* |
Jens Axboe | 8010c3b | 2009-09-15 20:04:57 +0200 | [diff] [blame] | 871 | * Nothing written. Wait for some inode to |
| 872 | * become available for writeback. Otherwise |
| 873 | * we'll just busyloop. |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 874 | */ |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 875 | if (!list_empty(&wb->b_more_io)) { |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 876 | trace_writeback_wait(wb->bdi, work); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 877 | inode = wb_inode(wb->b_more_io.prev); |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 878 | spin_lock(&inode->i_lock); |
Jan Kara | f0d07b7 | 2012-05-03 14:47:59 +0200 | [diff] [blame] | 879 | spin_unlock(&wb->list_lock); |
Jan Kara | 169ebd9 | 2012-05-03 14:48:03 +0200 | [diff] [blame] | 880 | /* This function drops i_lock... */ |
| 881 | inode_sleep_on_writeback(inode); |
Jan Kara | f0d07b7 | 2012-05-03 14:47:59 +0200 | [diff] [blame] | 882 | spin_lock(&wb->list_lock); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 883 | } |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 884 | } |
Wu Fengguang | e8dfc30 | 2011-04-21 12:06:32 -0600 | [diff] [blame] | 885 | spin_unlock(&wb->list_lock); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 886 | |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 887 | return nr_pages - work->nr_pages; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 888 | } |
| 889 | |
| 890 | /* |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 891 | * 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] | 892 | */ |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 893 | static struct wb_writeback_work * |
Minchan Kim | 08852b6 | 2010-08-03 12:51:16 +0200 | [diff] [blame] | 894 | get_next_work_item(struct backing_dev_info *bdi) |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 895 | { |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 896 | struct wb_writeback_work *work = NULL; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 897 | |
Artem Bityutskiy | 6467716 | 2010-07-25 14:29:22 +0300 | [diff] [blame] | 898 | spin_lock_bh(&bdi->wb_lock); |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 899 | if (!list_empty(&bdi->work_list)) { |
| 900 | work = list_entry(bdi->work_list.next, |
| 901 | struct wb_writeback_work, list); |
| 902 | list_del_init(&work->list); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 903 | } |
Artem Bityutskiy | 6467716 | 2010-07-25 14:29:22 +0300 | [diff] [blame] | 904 | spin_unlock_bh(&bdi->wb_lock); |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 905 | return work; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 906 | } |
| 907 | |
Linus Torvalds | cdf01dd | 2010-10-30 08:55:52 -0700 | [diff] [blame] | 908 | /* |
| 909 | * Add in the number of potentially dirty inodes, because each inode |
| 910 | * write can dirty pagecache in the underlying blockdev. |
| 911 | */ |
| 912 | static unsigned long get_nr_dirty_pages(void) |
| 913 | { |
| 914 | return global_page_state(NR_FILE_DIRTY) + |
| 915 | global_page_state(NR_UNSTABLE_NFS) + |
| 916 | get_nr_dirty_inodes(); |
| 917 | } |
| 918 | |
Jan Kara | 6585027 | 2011-01-13 15:45:44 -0800 | [diff] [blame] | 919 | static long wb_check_background_flush(struct bdi_writeback *wb) |
| 920 | { |
Wu Fengguang | b00949a | 2010-11-18 14:38:33 -0600 | [diff] [blame] | 921 | if (over_bground_thresh(wb->bdi)) { |
Jan Kara | 6585027 | 2011-01-13 15:45:44 -0800 | [diff] [blame] | 922 | |
| 923 | struct wb_writeback_work work = { |
| 924 | .nr_pages = LONG_MAX, |
| 925 | .sync_mode = WB_SYNC_NONE, |
| 926 | .for_background = 1, |
| 927 | .range_cyclic = 1, |
Curt Wohlgemuth | 0e175a1 | 2011-10-07 21:54:10 -0600 | [diff] [blame] | 928 | .reason = WB_REASON_BACKGROUND, |
Jan Kara | 6585027 | 2011-01-13 15:45:44 -0800 | [diff] [blame] | 929 | }; |
| 930 | |
| 931 | return wb_writeback(wb, &work); |
| 932 | } |
| 933 | |
| 934 | return 0; |
| 935 | } |
| 936 | |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 937 | static long wb_check_old_data_flush(struct bdi_writeback *wb) |
| 938 | { |
| 939 | unsigned long expired; |
| 940 | long nr_pages; |
| 941 | |
Jens Axboe | 69b62d0 | 2010-05-17 12:51:03 +0200 | [diff] [blame] | 942 | /* |
| 943 | * When set to zero, disable periodic writeback |
| 944 | */ |
| 945 | if (!dirty_writeback_interval) |
| 946 | return 0; |
| 947 | |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 948 | expired = wb->last_old_flush + |
| 949 | msecs_to_jiffies(dirty_writeback_interval * 10); |
| 950 | if (time_before(jiffies, expired)) |
| 951 | return 0; |
| 952 | |
| 953 | wb->last_old_flush = jiffies; |
Linus Torvalds | cdf01dd | 2010-10-30 08:55:52 -0700 | [diff] [blame] | 954 | nr_pages = get_nr_dirty_pages(); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 955 | |
Jens Axboe | c4a77a6 | 2009-09-16 15:18:25 +0200 | [diff] [blame] | 956 | if (nr_pages) { |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 957 | struct wb_writeback_work work = { |
Jens Axboe | c4a77a6 | 2009-09-16 15:18:25 +0200 | [diff] [blame] | 958 | .nr_pages = nr_pages, |
| 959 | .sync_mode = WB_SYNC_NONE, |
| 960 | .for_kupdate = 1, |
| 961 | .range_cyclic = 1, |
Curt Wohlgemuth | 0e175a1 | 2011-10-07 21:54:10 -0600 | [diff] [blame] | 962 | .reason = WB_REASON_PERIODIC, |
Jens Axboe | c4a77a6 | 2009-09-16 15:18:25 +0200 | [diff] [blame] | 963 | }; |
| 964 | |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 965 | return wb_writeback(wb, &work); |
Jens Axboe | c4a77a6 | 2009-09-16 15:18:25 +0200 | [diff] [blame] | 966 | } |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 967 | |
| 968 | return 0; |
| 969 | } |
| 970 | |
| 971 | /* |
| 972 | * Retrieve work items and do the writeback they describe |
| 973 | */ |
| 974 | long wb_do_writeback(struct bdi_writeback *wb, int force_wait) |
| 975 | { |
| 976 | struct backing_dev_info *bdi = wb->bdi; |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 977 | struct wb_writeback_work *work; |
Jens Axboe | c4a77a6 | 2009-09-16 15:18:25 +0200 | [diff] [blame] | 978 | long wrote = 0; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 979 | |
Jan Kara | 81d73a3 | 2010-08-11 14:17:44 -0700 | [diff] [blame] | 980 | set_bit(BDI_writeback_running, &wb->bdi->state); |
Minchan Kim | 08852b6 | 2010-08-03 12:51:16 +0200 | [diff] [blame] | 981 | while ((work = get_next_work_item(bdi)) != NULL) { |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 982 | /* |
| 983 | * Override sync mode, in case we must wait for completion |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 984 | * because this thread is exiting now. |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 985 | */ |
| 986 | if (force_wait) |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 987 | work->sync_mode = WB_SYNC_ALL; |
| 988 | |
Dave Chinner | 455b286 | 2010-07-07 13:24:06 +1000 | [diff] [blame] | 989 | trace_writeback_exec(bdi, work); |
| 990 | |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 991 | wrote += wb_writeback(wb, work); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 992 | |
| 993 | /* |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 994 | * Notify the caller of completion if this is a synchronous |
| 995 | * work item, otherwise just free it. |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 996 | */ |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 997 | if (work->done) |
| 998 | complete(work->done); |
| 999 | else |
| 1000 | kfree(work); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1001 | } |
| 1002 | |
| 1003 | /* |
| 1004 | * Check for periodic writeback, kupdated() style |
| 1005 | */ |
| 1006 | wrote += wb_check_old_data_flush(wb); |
Jan Kara | 6585027 | 2011-01-13 15:45:44 -0800 | [diff] [blame] | 1007 | wrote += wb_check_background_flush(wb); |
Jan Kara | 81d73a3 | 2010-08-11 14:17:44 -0700 | [diff] [blame] | 1008 | clear_bit(BDI_writeback_running, &wb->bdi->state); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1009 | |
| 1010 | return wrote; |
| 1011 | } |
| 1012 | |
| 1013 | /* |
| 1014 | * Handle writeback of dirty data for the device backed by this bdi. Also |
| 1015 | * wakes up periodically and does kupdated style flushing. |
| 1016 | */ |
Christoph Hellwig | 0824390 | 2010-06-19 23:08:22 +0200 | [diff] [blame] | 1017 | int bdi_writeback_thread(void *data) |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1018 | { |
Christoph Hellwig | 0824390 | 2010-06-19 23:08:22 +0200 | [diff] [blame] | 1019 | struct bdi_writeback *wb = data; |
| 1020 | struct backing_dev_info *bdi = wb->bdi; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1021 | long pages_written; |
| 1022 | |
Peter Zijlstra | 766f916 | 2010-10-26 14:22:45 -0700 | [diff] [blame] | 1023 | current->flags |= PF_SWAPWRITE; |
Christoph Hellwig | 0824390 | 2010-06-19 23:08:22 +0200 | [diff] [blame] | 1024 | set_freezable(); |
Artem Bityutskiy | ecd5840 | 2010-07-25 14:29:18 +0300 | [diff] [blame] | 1025 | wb->last_active = jiffies; |
Christoph Hellwig | 0824390 | 2010-06-19 23:08:22 +0200 | [diff] [blame] | 1026 | |
| 1027 | /* |
| 1028 | * Our parent may run at a different priority, just set us to normal |
| 1029 | */ |
| 1030 | set_user_nice(current, 0); |
| 1031 | |
Dave Chinner | 455b286 | 2010-07-07 13:24:06 +1000 | [diff] [blame] | 1032 | trace_writeback_thread_start(bdi); |
| 1033 | |
Tejun Heo | 8a32c44 | 2011-11-21 12:32:23 -0800 | [diff] [blame] | 1034 | while (!kthread_freezable_should_stop(NULL)) { |
Artem Bityutskiy | 6467716 | 2010-07-25 14:29:22 +0300 | [diff] [blame] | 1035 | /* |
| 1036 | * Remove own delayed wake-up timer, since we are already awake |
Yan Hong | 5aaea51 | 2012-12-12 13:52:14 -0800 | [diff] [blame] | 1037 | * and we'll take care of the periodic write-back. |
Artem Bityutskiy | 6467716 | 2010-07-25 14:29:22 +0300 | [diff] [blame] | 1038 | */ |
| 1039 | del_timer(&wb->wakeup_timer); |
| 1040 | |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1041 | pages_written = wb_do_writeback(wb, 0); |
| 1042 | |
Dave Chinner | 455b286 | 2010-07-07 13:24:06 +1000 | [diff] [blame] | 1043 | trace_writeback_pages_written(pages_written); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1044 | |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1045 | if (pages_written) |
Artem Bityutskiy | ecd5840 | 2010-07-25 14:29:18 +0300 | [diff] [blame] | 1046 | wb->last_active = jiffies; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1047 | |
Artem Bityutskiy | 297252c | 2010-07-25 14:29:15 +0300 | [diff] [blame] | 1048 | set_current_state(TASK_INTERRUPTIBLE); |
J. Bruce Fields | b76b401 | 2010-08-28 08:52:10 +0200 | [diff] [blame] | 1049 | if (!list_empty(&bdi->work_list) || kthread_should_stop()) { |
Artem Bityutskiy | 297252c | 2010-07-25 14:29:15 +0300 | [diff] [blame] | 1050 | __set_current_state(TASK_RUNNING); |
| 1051 | continue; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1052 | } |
| 1053 | |
Artem Bityutskiy | 253c34e | 2010-07-25 14:29:21 +0300 | [diff] [blame] | 1054 | if (wb_has_dirty_io(wb) && dirty_writeback_interval) |
Artem Bityutskiy | fff5b85 | 2010-07-25 14:29:20 +0300 | [diff] [blame] | 1055 | schedule_timeout(msecs_to_jiffies(dirty_writeback_interval * 10)); |
Artem Bityutskiy | 253c34e | 2010-07-25 14:29:21 +0300 | [diff] [blame] | 1056 | else { |
| 1057 | /* |
| 1058 | * We have nothing to do, so can go sleep without any |
| 1059 | * timeout and save power. When a work is queued or |
| 1060 | * something is made dirty - we will be woken up. |
| 1061 | */ |
Artem Bityutskiy | 297252c | 2010-07-25 14:29:15 +0300 | [diff] [blame] | 1062 | schedule(); |
Jens Axboe | f9eadbb | 2010-05-18 14:31:45 +0200 | [diff] [blame] | 1063 | } |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1064 | } |
| 1065 | |
Artem Bityutskiy | fff5b85 | 2010-07-25 14:29:20 +0300 | [diff] [blame] | 1066 | /* Flush any work that raced with us exiting */ |
Christoph Hellwig | 0824390 | 2010-06-19 23:08:22 +0200 | [diff] [blame] | 1067 | if (!list_empty(&bdi->work_list)) |
| 1068 | wb_do_writeback(wb, 1); |
Dave Chinner | 455b286 | 2010-07-07 13:24:06 +1000 | [diff] [blame] | 1069 | |
| 1070 | trace_writeback_thread_stop(bdi); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1071 | return 0; |
| 1072 | } |
| 1073 | |
Christoph Hellwig | 0824390 | 2010-06-19 23:08:22 +0200 | [diff] [blame] | 1074 | |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1075 | /* |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1076 | * Start writeback of `nr_pages' pages. If `nr_pages' is zero, write back |
| 1077 | * the whole world. |
| 1078 | */ |
Curt Wohlgemuth | 0e175a1 | 2011-10-07 21:54:10 -0600 | [diff] [blame] | 1079 | void wakeup_flusher_threads(long nr_pages, enum wb_reason reason) |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1080 | { |
Christoph Hellwig | b8c2f34 | 2010-06-08 18:15:07 +0200 | [diff] [blame] | 1081 | struct backing_dev_info *bdi; |
Christoph Hellwig | b8c2f34 | 2010-06-08 18:15:07 +0200 | [diff] [blame] | 1082 | |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 1083 | if (!nr_pages) { |
| 1084 | nr_pages = global_page_state(NR_FILE_DIRTY) + |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1085 | global_page_state(NR_UNSTABLE_NFS); |
Christoph Hellwig | b8c2f34 | 2010-06-08 18:15:07 +0200 | [diff] [blame] | 1086 | } |
| 1087 | |
| 1088 | rcu_read_lock(); |
| 1089 | list_for_each_entry_rcu(bdi, &bdi_list, bdi_list) { |
| 1090 | if (!bdi_has_dirty_io(bdi)) |
| 1091 | continue; |
Curt Wohlgemuth | 0e175a1 | 2011-10-07 21:54:10 -0600 | [diff] [blame] | 1092 | __bdi_start_writeback(bdi, nr_pages, false, reason); |
Christoph Hellwig | b8c2f34 | 2010-06-08 18:15:07 +0200 | [diff] [blame] | 1093 | } |
| 1094 | rcu_read_unlock(); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1095 | } |
| 1096 | |
| 1097 | static noinline void block_dump___mark_inode_dirty(struct inode *inode) |
| 1098 | { |
| 1099 | if (inode->i_ino || strcmp(inode->i_sb->s_id, "bdev")) { |
| 1100 | struct dentry *dentry; |
| 1101 | const char *name = "?"; |
| 1102 | |
| 1103 | dentry = d_find_alias(inode); |
| 1104 | if (dentry) { |
| 1105 | spin_lock(&dentry->d_lock); |
| 1106 | name = (const char *) dentry->d_name.name; |
| 1107 | } |
| 1108 | printk(KERN_DEBUG |
| 1109 | "%s(%d): dirtied inode %lu (%s) on %s\n", |
| 1110 | current->comm, task_pid_nr(current), inode->i_ino, |
| 1111 | name, inode->i_sb->s_id); |
| 1112 | if (dentry) { |
| 1113 | spin_unlock(&dentry->d_lock); |
| 1114 | dput(dentry); |
| 1115 | } |
| 1116 | } |
| 1117 | } |
| 1118 | |
| 1119 | /** |
| 1120 | * __mark_inode_dirty - internal function |
| 1121 | * @inode: inode to mark |
| 1122 | * @flags: what kind of dirty (i.e. I_DIRTY_SYNC) |
| 1123 | * Mark an inode as dirty. Callers should use mark_inode_dirty or |
| 1124 | * mark_inode_dirty_sync. |
| 1125 | * |
| 1126 | * Put the inode on the super block's dirty list. |
| 1127 | * |
| 1128 | * CAREFUL! We mark it dirty unconditionally, but move it onto the |
| 1129 | * dirty list only if it is hashed or if it refers to a blockdev. |
| 1130 | * If it was not hashed, it will never be added to the dirty list |
| 1131 | * even if it is later hashed, as it will have been marked dirty already. |
| 1132 | * |
| 1133 | * In short, make sure you hash any inodes _before_ you start marking |
| 1134 | * them dirty. |
| 1135 | * |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1136 | * Note that for blockdevs, inode->dirtied_when represents the dirtying time of |
| 1137 | * the block-special inode (/dev/hda1) itself. And the ->dirtied_when field of |
| 1138 | * the kernel-internal blockdev inode represents the dirtying time of the |
| 1139 | * blockdev's pages. This is why for I_DIRTY_PAGES we always use |
| 1140 | * page->mapping->host, so the page-dirtying time is recorded in the internal |
| 1141 | * blockdev inode. |
| 1142 | */ |
| 1143 | void __mark_inode_dirty(struct inode *inode, int flags) |
| 1144 | { |
| 1145 | struct super_block *sb = inode->i_sb; |
Artem Bityutskiy | 253c34e | 2010-07-25 14:29:21 +0300 | [diff] [blame] | 1146 | struct backing_dev_info *bdi = NULL; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1147 | |
| 1148 | /* |
| 1149 | * Don't do this for I_DIRTY_PAGES - that doesn't actually |
| 1150 | * dirty the inode itself |
| 1151 | */ |
| 1152 | if (flags & (I_DIRTY_SYNC | I_DIRTY_DATASYNC)) { |
| 1153 | if (sb->s_op->dirty_inode) |
Christoph Hellwig | aa38572 | 2011-05-27 06:53:02 -0400 | [diff] [blame] | 1154 | sb->s_op->dirty_inode(inode, flags); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1155 | } |
| 1156 | |
| 1157 | /* |
| 1158 | * make sure that changes are seen by all cpus before we test i_state |
| 1159 | * -- mikulas |
| 1160 | */ |
| 1161 | smp_mb(); |
| 1162 | |
| 1163 | /* avoid the locking if we can */ |
| 1164 | if ((inode->i_state & flags) == flags) |
| 1165 | return; |
| 1166 | |
| 1167 | if (unlikely(block_dump)) |
| 1168 | block_dump___mark_inode_dirty(inode); |
| 1169 | |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 1170 | spin_lock(&inode->i_lock); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1171 | if ((inode->i_state & flags) != flags) { |
| 1172 | const int was_dirty = inode->i_state & I_DIRTY; |
| 1173 | |
| 1174 | inode->i_state |= flags; |
| 1175 | |
| 1176 | /* |
| 1177 | * If the inode is being synced, just update its dirty state. |
| 1178 | * The unlocker will place the inode on the appropriate |
| 1179 | * superblock list, based upon its state. |
| 1180 | */ |
| 1181 | if (inode->i_state & I_SYNC) |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 1182 | goto out_unlock_inode; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1183 | |
| 1184 | /* |
| 1185 | * Only add valid (hashed) inodes to the superblock's |
| 1186 | * dirty list. Add blockdev inodes as well. |
| 1187 | */ |
| 1188 | if (!S_ISBLK(inode->i_mode)) { |
Al Viro | 1d3382cb | 2010-10-23 15:19:20 -0400 | [diff] [blame] | 1189 | if (inode_unhashed(inode)) |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 1190 | goto out_unlock_inode; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1191 | } |
Al Viro | a4ffdde | 2010-06-02 17:38:30 -0400 | [diff] [blame] | 1192 | if (inode->i_state & I_FREEING) |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 1193 | goto out_unlock_inode; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1194 | |
| 1195 | /* |
| 1196 | * If the inode was already on b_dirty/b_io/b_more_io, don't |
| 1197 | * reposition it (that would break b_dirty time-ordering). |
| 1198 | */ |
| 1199 | if (!was_dirty) { |
Dave Chinner | a66979a | 2011-03-22 22:23:41 +1100 | [diff] [blame] | 1200 | bool wakeup_bdi = false; |
Artem Bityutskiy | 253c34e | 2010-07-25 14:29:21 +0300 | [diff] [blame] | 1201 | bdi = inode_to_bdi(inode); |
Jens Axboe | 500b067 | 2009-09-09 09:10:25 +0200 | [diff] [blame] | 1202 | |
Artem Bityutskiy | 253c34e | 2010-07-25 14:29:21 +0300 | [diff] [blame] | 1203 | if (bdi_cap_writeback_dirty(bdi)) { |
| 1204 | WARN(!test_bit(BDI_registered, &bdi->state), |
| 1205 | "bdi-%s not registered\n", bdi->name); |
| 1206 | |
| 1207 | /* |
| 1208 | * If this is the first dirty inode for this |
| 1209 | * bdi, we have to wake-up the corresponding |
| 1210 | * bdi thread to make sure background |
| 1211 | * write-back happens later. |
| 1212 | */ |
| 1213 | if (!wb_has_dirty_io(&bdi->wb)) |
| 1214 | wakeup_bdi = true; |
Jens Axboe | 500b067 | 2009-09-09 09:10:25 +0200 | [diff] [blame] | 1215 | } |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1216 | |
Dave Chinner | a66979a | 2011-03-22 22:23:41 +1100 | [diff] [blame] | 1217 | spin_unlock(&inode->i_lock); |
Christoph Hellwig | f758eea | 2011-04-21 18:19:44 -0600 | [diff] [blame] | 1218 | spin_lock(&bdi->wb.list_lock); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1219 | inode->dirtied_when = jiffies; |
Nick Piggin | 7ccf19a | 2010-10-21 11:49:30 +1100 | [diff] [blame] | 1220 | list_move(&inode->i_wb_list, &bdi->wb.b_dirty); |
Christoph Hellwig | f758eea | 2011-04-21 18:19:44 -0600 | [diff] [blame] | 1221 | spin_unlock(&bdi->wb.list_lock); |
Dave Chinner | a66979a | 2011-03-22 22:23:41 +1100 | [diff] [blame] | 1222 | |
| 1223 | if (wakeup_bdi) |
| 1224 | bdi_wakeup_thread_delayed(bdi); |
| 1225 | return; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1226 | } |
| 1227 | } |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 1228 | out_unlock_inode: |
| 1229 | spin_unlock(&inode->i_lock); |
Artem Bityutskiy | 253c34e | 2010-07-25 14:29:21 +0300 | [diff] [blame] | 1230 | |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1231 | } |
| 1232 | EXPORT_SYMBOL(__mark_inode_dirty); |
| 1233 | |
Jens Axboe | b6e5131 | 2009-09-16 15:13:54 +0200 | [diff] [blame] | 1234 | static void wait_sb_inodes(struct super_block *sb) |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 1235 | { |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1236 | struct inode *inode, *old_inode = NULL; |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 1237 | |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1238 | /* |
| 1239 | * We need to be protected against the filesystem going from |
| 1240 | * r/o to r/w or vice versa. |
| 1241 | */ |
Jens Axboe | b6e5131 | 2009-09-16 15:13:54 +0200 | [diff] [blame] | 1242 | WARN_ON(!rwsem_is_locked(&sb->s_umount)); |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 1243 | |
Dave Chinner | 55fa609 | 2011-03-22 22:23:40 +1100 | [diff] [blame] | 1244 | spin_lock(&inode_sb_list_lock); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1245 | |
| 1246 | /* |
| 1247 | * Data integrity sync. Must wait for all pages under writeback, |
| 1248 | * because there may have been pages dirtied before our sync |
| 1249 | * call, but which had writeout started before we write it out. |
| 1250 | * In which case, the inode may not be on the dirty list, but |
| 1251 | * we still have to wait for that writeout. |
| 1252 | */ |
Jens Axboe | b6e5131 | 2009-09-16 15:13:54 +0200 | [diff] [blame] | 1253 | list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 1254 | struct address_space *mapping = inode->i_mapping; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1255 | |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 1256 | spin_lock(&inode->i_lock); |
| 1257 | if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) || |
| 1258 | (mapping->nrpages == 0)) { |
| 1259 | spin_unlock(&inode->i_lock); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1260 | continue; |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 1261 | } |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1262 | __iget(inode); |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 1263 | spin_unlock(&inode->i_lock); |
Dave Chinner | 55fa609 | 2011-03-22 22:23:40 +1100 | [diff] [blame] | 1264 | spin_unlock(&inode_sb_list_lock); |
| 1265 | |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1266 | /* |
Dave Chinner | 55fa609 | 2011-03-22 22:23:40 +1100 | [diff] [blame] | 1267 | * We hold a reference to 'inode' so it couldn't have been |
| 1268 | * removed from s_inodes list while we dropped the |
| 1269 | * inode_sb_list_lock. We cannot iput the inode now as we can |
| 1270 | * be holding the last reference and we cannot iput it under |
| 1271 | * inode_sb_list_lock. So we keep the reference and iput it |
| 1272 | * later. |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1273 | */ |
| 1274 | iput(old_inode); |
| 1275 | old_inode = inode; |
| 1276 | |
| 1277 | filemap_fdatawait(mapping); |
| 1278 | |
| 1279 | cond_resched(); |
Nick Piggin | 38f2197 | 2009-01-06 14:40:25 -0800 | [diff] [blame] | 1280 | |
Dave Chinner | 55fa609 | 2011-03-22 22:23:40 +1100 | [diff] [blame] | 1281 | spin_lock(&inode_sb_list_lock); |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 1282 | } |
Dave Chinner | 55fa609 | 2011-03-22 22:23:40 +1100 | [diff] [blame] | 1283 | spin_unlock(&inode_sb_list_lock); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1284 | iput(old_inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1285 | } |
| 1286 | |
Jens Axboe | d8a8559 | 2009-09-02 12:34:32 +0200 | [diff] [blame] | 1287 | /** |
Chris Mason | 3259f8b | 2010-10-29 11:16:17 -0400 | [diff] [blame] | 1288 | * writeback_inodes_sb_nr - writeback dirty inodes from given super_block |
Jens Axboe | d8a8559 | 2009-09-02 12:34:32 +0200 | [diff] [blame] | 1289 | * @sb: the superblock |
Chris Mason | 3259f8b | 2010-10-29 11:16:17 -0400 | [diff] [blame] | 1290 | * @nr: the number of pages to write |
Marcos Paulo de Souza | 786228a | 2011-11-23 20:56:45 +0800 | [diff] [blame] | 1291 | * @reason: reason why some writeback work initiated |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1292 | * |
Jens Axboe | d8a8559 | 2009-09-02 12:34:32 +0200 | [diff] [blame] | 1293 | * Start writeback on some inodes on this super_block. No guarantees are made |
| 1294 | * 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] | 1295 | * for IO completion of submitted IO. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1296 | */ |
Curt Wohlgemuth | 0e175a1 | 2011-10-07 21:54:10 -0600 | [diff] [blame] | 1297 | void writeback_inodes_sb_nr(struct super_block *sb, |
| 1298 | unsigned long nr, |
| 1299 | enum wb_reason reason) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1300 | { |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 1301 | DECLARE_COMPLETION_ONSTACK(done); |
| 1302 | struct wb_writeback_work work = { |
Wu Fengguang | 6e6938b | 2010-06-06 10:38:15 -0600 | [diff] [blame] | 1303 | .sb = sb, |
| 1304 | .sync_mode = WB_SYNC_NONE, |
| 1305 | .tagged_writepages = 1, |
| 1306 | .done = &done, |
| 1307 | .nr_pages = nr, |
Curt Wohlgemuth | 0e175a1 | 2011-10-07 21:54:10 -0600 | [diff] [blame] | 1308 | .reason = reason, |
Christoph Hellwig | 3c4d716 | 2010-06-08 18:14:43 +0200 | [diff] [blame] | 1309 | }; |
Jens Axboe | 0e3c9a2 | 2010-06-01 11:08:43 +0200 | [diff] [blame] | 1310 | |
Jan Kara | 6eedc70 | 2012-07-03 16:45:27 +0200 | [diff] [blame] | 1311 | if (sb->s_bdi == &noop_backing_dev_info) |
| 1312 | return; |
Christoph Hellwig | cf37e97 | 2010-06-08 18:14:51 +0200 | [diff] [blame] | 1313 | WARN_ON(!rwsem_is_locked(&sb->s_umount)); |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 1314 | bdi_queue_work(sb->s_bdi, &work); |
| 1315 | wait_for_completion(&done); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1316 | } |
Chris Mason | 3259f8b | 2010-10-29 11:16:17 -0400 | [diff] [blame] | 1317 | EXPORT_SYMBOL(writeback_inodes_sb_nr); |
| 1318 | |
| 1319 | /** |
| 1320 | * writeback_inodes_sb - writeback dirty inodes from given super_block |
| 1321 | * @sb: the superblock |
Marcos Paulo de Souza | 786228a | 2011-11-23 20:56:45 +0800 | [diff] [blame] | 1322 | * @reason: reason why some writeback work was initiated |
Chris Mason | 3259f8b | 2010-10-29 11:16:17 -0400 | [diff] [blame] | 1323 | * |
| 1324 | * Start writeback on some inodes on this super_block. No guarantees are made |
| 1325 | * on how many (if any) will be written, and this function does not wait |
| 1326 | * for IO completion of submitted IO. |
| 1327 | */ |
Curt Wohlgemuth | 0e175a1 | 2011-10-07 21:54:10 -0600 | [diff] [blame] | 1328 | void writeback_inodes_sb(struct super_block *sb, enum wb_reason reason) |
Chris Mason | 3259f8b | 2010-10-29 11:16:17 -0400 | [diff] [blame] | 1329 | { |
Curt Wohlgemuth | 0e175a1 | 2011-10-07 21:54:10 -0600 | [diff] [blame] | 1330 | return writeback_inodes_sb_nr(sb, get_nr_dirty_pages(), reason); |
Chris Mason | 3259f8b | 2010-10-29 11:16:17 -0400 | [diff] [blame] | 1331 | } |
Jens Axboe | d8a8559 | 2009-09-02 12:34:32 +0200 | [diff] [blame] | 1332 | EXPORT_SYMBOL(writeback_inodes_sb); |
| 1333 | |
| 1334 | /** |
Eric Sandeen | 17bd55d | 2009-12-23 07:57:07 -0500 | [diff] [blame] | 1335 | * writeback_inodes_sb_if_idle - start writeback if none underway |
| 1336 | * @sb: the superblock |
Marcos Paulo de Souza | 786228a | 2011-11-23 20:56:45 +0800 | [diff] [blame] | 1337 | * @reason: reason why some writeback work was initiated |
Eric Sandeen | 17bd55d | 2009-12-23 07:57:07 -0500 | [diff] [blame] | 1338 | * |
| 1339 | * Invoke writeback_inodes_sb if no writeback is currently underway. |
| 1340 | * Returns 1 if writeback was started, 0 if not. |
| 1341 | */ |
Curt Wohlgemuth | 0e175a1 | 2011-10-07 21:54:10 -0600 | [diff] [blame] | 1342 | int writeback_inodes_sb_if_idle(struct super_block *sb, enum wb_reason reason) |
Eric Sandeen | 17bd55d | 2009-12-23 07:57:07 -0500 | [diff] [blame] | 1343 | { |
| 1344 | if (!writeback_in_progress(sb->s_bdi)) { |
Christoph Hellwig | cf37e97 | 2010-06-08 18:14:51 +0200 | [diff] [blame] | 1345 | down_read(&sb->s_umount); |
Curt Wohlgemuth | 0e175a1 | 2011-10-07 21:54:10 -0600 | [diff] [blame] | 1346 | writeback_inodes_sb(sb, reason); |
Christoph Hellwig | cf37e97 | 2010-06-08 18:14:51 +0200 | [diff] [blame] | 1347 | up_read(&sb->s_umount); |
Eric Sandeen | 17bd55d | 2009-12-23 07:57:07 -0500 | [diff] [blame] | 1348 | return 1; |
| 1349 | } else |
| 1350 | return 0; |
| 1351 | } |
| 1352 | EXPORT_SYMBOL(writeback_inodes_sb_if_idle); |
| 1353 | |
| 1354 | /** |
Fengguang Wu | c097b2c | 2012-03-05 15:08:06 -0800 | [diff] [blame] | 1355 | * writeback_inodes_sb_nr_if_idle - start writeback if none underway |
Chris Mason | 3259f8b | 2010-10-29 11:16:17 -0400 | [diff] [blame] | 1356 | * @sb: the superblock |
| 1357 | * @nr: the number of pages to write |
Marcos Paulo de Souza | 786228a | 2011-11-23 20:56:45 +0800 | [diff] [blame] | 1358 | * @reason: reason why some writeback work was initiated |
Chris Mason | 3259f8b | 2010-10-29 11:16:17 -0400 | [diff] [blame] | 1359 | * |
| 1360 | * Invoke writeback_inodes_sb if no writeback is currently underway. |
| 1361 | * Returns 1 if writeback was started, 0 if not. |
| 1362 | */ |
| 1363 | int writeback_inodes_sb_nr_if_idle(struct super_block *sb, |
Curt Wohlgemuth | 0e175a1 | 2011-10-07 21:54:10 -0600 | [diff] [blame] | 1364 | unsigned long nr, |
| 1365 | enum wb_reason reason) |
Chris Mason | 3259f8b | 2010-10-29 11:16:17 -0400 | [diff] [blame] | 1366 | { |
| 1367 | if (!writeback_in_progress(sb->s_bdi)) { |
| 1368 | down_read(&sb->s_umount); |
Curt Wohlgemuth | 0e175a1 | 2011-10-07 21:54:10 -0600 | [diff] [blame] | 1369 | writeback_inodes_sb_nr(sb, nr, reason); |
Chris Mason | 3259f8b | 2010-10-29 11:16:17 -0400 | [diff] [blame] | 1370 | up_read(&sb->s_umount); |
| 1371 | return 1; |
| 1372 | } else |
| 1373 | return 0; |
| 1374 | } |
| 1375 | EXPORT_SYMBOL(writeback_inodes_sb_nr_if_idle); |
| 1376 | |
| 1377 | /** |
Jens Axboe | d8a8559 | 2009-09-02 12:34:32 +0200 | [diff] [blame] | 1378 | * sync_inodes_sb - sync sb inode pages |
| 1379 | * @sb: the superblock |
| 1380 | * |
| 1381 | * This function writes and waits on any dirty inode belonging to this |
Stefan Hajnoczi | cb9ef8d | 2011-01-13 15:47:26 -0800 | [diff] [blame] | 1382 | * super_block. |
Jens Axboe | d8a8559 | 2009-09-02 12:34:32 +0200 | [diff] [blame] | 1383 | */ |
Jens Axboe | b6e5131 | 2009-09-16 15:13:54 +0200 | [diff] [blame] | 1384 | void sync_inodes_sb(struct super_block *sb) |
Jens Axboe | d8a8559 | 2009-09-02 12:34:32 +0200 | [diff] [blame] | 1385 | { |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 1386 | DECLARE_COMPLETION_ONSTACK(done); |
| 1387 | struct wb_writeback_work work = { |
Christoph Hellwig | 3c4d716 | 2010-06-08 18:14:43 +0200 | [diff] [blame] | 1388 | .sb = sb, |
| 1389 | .sync_mode = WB_SYNC_ALL, |
| 1390 | .nr_pages = LONG_MAX, |
| 1391 | .range_cyclic = 0, |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 1392 | .done = &done, |
Curt Wohlgemuth | 0e175a1 | 2011-10-07 21:54:10 -0600 | [diff] [blame] | 1393 | .reason = WB_REASON_SYNC, |
Christoph Hellwig | 3c4d716 | 2010-06-08 18:14:43 +0200 | [diff] [blame] | 1394 | }; |
| 1395 | |
Jan Kara | 6eedc70 | 2012-07-03 16:45:27 +0200 | [diff] [blame] | 1396 | /* Nothing to do? */ |
| 1397 | if (sb->s_bdi == &noop_backing_dev_info) |
| 1398 | return; |
Christoph Hellwig | cf37e97 | 2010-06-08 18:14:51 +0200 | [diff] [blame] | 1399 | WARN_ON(!rwsem_is_locked(&sb->s_umount)); |
| 1400 | |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 1401 | bdi_queue_work(sb->s_bdi, &work); |
| 1402 | wait_for_completion(&done); |
| 1403 | |
Jens Axboe | b6e5131 | 2009-09-16 15:13:54 +0200 | [diff] [blame] | 1404 | wait_sb_inodes(sb); |
Jens Axboe | d8a8559 | 2009-09-02 12:34:32 +0200 | [diff] [blame] | 1405 | } |
| 1406 | EXPORT_SYMBOL(sync_inodes_sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1407 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1408 | /** |
Andrea Arcangeli | 7f04c26 | 2005-10-30 15:03:05 -0800 | [diff] [blame] | 1409 | * write_inode_now - write an inode to disk |
| 1410 | * @inode: inode to write to disk |
| 1411 | * @sync: whether the write should be synchronous or not |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1412 | * |
Andrea Arcangeli | 7f04c26 | 2005-10-30 15:03:05 -0800 | [diff] [blame] | 1413 | * This function commits an inode to disk immediately if it is dirty. This is |
| 1414 | * primarily needed by knfsd. |
| 1415 | * |
| 1416 | * 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] | 1417 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1418 | int write_inode_now(struct inode *inode, int sync) |
| 1419 | { |
Christoph Hellwig | f758eea | 2011-04-21 18:19:44 -0600 | [diff] [blame] | 1420 | struct bdi_writeback *wb = &inode_to_bdi(inode)->wb; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1421 | struct writeback_control wbc = { |
| 1422 | .nr_to_write = LONG_MAX, |
Mike Galbraith | 18914b1 | 2008-02-08 04:20:23 -0800 | [diff] [blame] | 1423 | .sync_mode = sync ? WB_SYNC_ALL : WB_SYNC_NONE, |
OGAWA Hirofumi | 111ebb6 | 2006-06-23 02:03:26 -0700 | [diff] [blame] | 1424 | .range_start = 0, |
| 1425 | .range_end = LLONG_MAX, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1426 | }; |
| 1427 | |
| 1428 | if (!mapping_cap_writeback_dirty(inode->i_mapping)) |
Andrew Morton | 49364ce | 2005-11-07 00:59:15 -0800 | [diff] [blame] | 1429 | wbc.nr_to_write = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1430 | |
| 1431 | might_sleep(); |
Jan Kara | 4f8ad65 | 2012-05-03 14:48:00 +0200 | [diff] [blame] | 1432 | return writeback_single_inode(inode, wb, &wbc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1433 | } |
| 1434 | EXPORT_SYMBOL(write_inode_now); |
| 1435 | |
| 1436 | /** |
| 1437 | * sync_inode - write an inode and its pages to disk. |
| 1438 | * @inode: the inode to sync |
| 1439 | * @wbc: controls the writeback mode |
| 1440 | * |
| 1441 | * sync_inode() will write an inode and its pages to disk. It will also |
| 1442 | * correctly update the inode on its superblock's dirty inode lists and will |
| 1443 | * update inode->i_state. |
| 1444 | * |
| 1445 | * The caller must have a ref on the inode. |
| 1446 | */ |
| 1447 | int sync_inode(struct inode *inode, struct writeback_control *wbc) |
| 1448 | { |
Jan Kara | 4f8ad65 | 2012-05-03 14:48:00 +0200 | [diff] [blame] | 1449 | return writeback_single_inode(inode, &inode_to_bdi(inode)->wb, wbc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1450 | } |
| 1451 | EXPORT_SYMBOL(sync_inode); |
Christoph Hellwig | c3765016 | 2010-10-06 10:48:20 +0200 | [diff] [blame] | 1452 | |
| 1453 | /** |
Andrew Morton | c691b9d | 2011-01-13 15:45:48 -0800 | [diff] [blame] | 1454 | * sync_inode_metadata - write an inode to disk |
Christoph Hellwig | c3765016 | 2010-10-06 10:48:20 +0200 | [diff] [blame] | 1455 | * @inode: the inode to sync |
| 1456 | * @wait: wait for I/O to complete. |
| 1457 | * |
Andrew Morton | c691b9d | 2011-01-13 15:45:48 -0800 | [diff] [blame] | 1458 | * Write an inode to disk and adjust its dirty state after completion. |
Christoph Hellwig | c3765016 | 2010-10-06 10:48:20 +0200 | [diff] [blame] | 1459 | * |
| 1460 | * Note: only writes the actual inode, no associated data or other metadata. |
| 1461 | */ |
| 1462 | int sync_inode_metadata(struct inode *inode, int wait) |
| 1463 | { |
| 1464 | struct writeback_control wbc = { |
| 1465 | .sync_mode = wait ? WB_SYNC_ALL : WB_SYNC_NONE, |
| 1466 | .nr_to_write = 0, /* metadata-only */ |
| 1467 | }; |
| 1468 | |
| 1469 | return sync_inode(inode, &wbc); |
| 1470 | } |
| 1471 | EXPORT_SYMBOL(sync_inode_metadata); |