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> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 25 | #include <linux/writeback.h> |
| 26 | #include <linux/blkdev.h> |
| 27 | #include <linux/backing-dev.h> |
Dave Chinner | 455b286 | 2010-07-07 13:24:06 +1000 | [diff] [blame] | 28 | #include <linux/tracepoint.h> |
Al Viro | 719ea2f | 2013-09-29 11:24:49 -0400 | [diff] [blame] | 29 | #include <linux/device.h> |
Tejun Heo | 21c6321 | 2015-05-28 14:50:49 -0400 | [diff] [blame^] | 30 | #include <linux/memcontrol.h> |
David Howells | 07f3f05c | 2006-09-30 20:52:18 +0200 | [diff] [blame] | 31 | #include "internal.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | |
Jens Axboe | d0bceac | 2009-05-18 08:20:32 +0200 | [diff] [blame] | 33 | /* |
Wu Fengguang | bc31b86 | 2012-01-07 20:41:55 -0600 | [diff] [blame] | 34 | * 4MB minimal write chunk size |
| 35 | */ |
| 36 | #define MIN_WRITEBACK_PAGES (4096UL >> (PAGE_CACHE_SHIFT - 10)) |
| 37 | |
Tejun Heo | cc395d7 | 2015-05-22 17:13:58 -0400 | [diff] [blame] | 38 | struct wb_completion { |
| 39 | atomic_t cnt; |
| 40 | }; |
| 41 | |
Wu Fengguang | bc31b86 | 2012-01-07 20:41:55 -0600 | [diff] [blame] | 42 | /* |
Jens Axboe | c4a77a6 | 2009-09-16 15:18:25 +0200 | [diff] [blame] | 43 | * Passed into wb_writeback(), essentially a subset of writeback_control |
| 44 | */ |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 45 | struct wb_writeback_work { |
Jens Axboe | c4a77a6 | 2009-09-16 15:18:25 +0200 | [diff] [blame] | 46 | long nr_pages; |
| 47 | struct super_block *sb; |
Jan Kara | 0dc83bd | 2014-02-21 11:19:04 +0100 | [diff] [blame] | 48 | unsigned long *older_than_this; |
Jens Axboe | c4a77a6 | 2009-09-16 15:18:25 +0200 | [diff] [blame] | 49 | enum writeback_sync_modes sync_mode; |
Wu Fengguang | 6e6938b | 2010-06-06 10:38:15 -0600 | [diff] [blame] | 50 | unsigned int tagged_writepages:1; |
H Hartley Sweeten | 52957fe | 2010-04-01 20:36:30 -0500 | [diff] [blame] | 51 | unsigned int for_kupdate:1; |
| 52 | unsigned int range_cyclic:1; |
| 53 | unsigned int for_background:1; |
Dave Chinner | 7747bd4 | 2013-07-02 22:38:35 +1000 | [diff] [blame] | 54 | unsigned int for_sync:1; /* sync(2) WB_SYNC_ALL writeback */ |
Tejun Heo | ac7b19a | 2015-05-22 17:13:57 -0400 | [diff] [blame] | 55 | unsigned int auto_free:1; /* free on completion */ |
Tejun Heo | 98754bf | 2015-05-22 17:13:59 -0400 | [diff] [blame] | 56 | unsigned int single_wait:1; |
| 57 | unsigned int single_done:1; |
Curt Wohlgemuth | 0e175a1 | 2011-10-07 21:54:10 -0600 | [diff] [blame] | 58 | enum wb_reason reason; /* why was writeback initiated? */ |
Jens Axboe | c4a77a6 | 2009-09-16 15:18:25 +0200 | [diff] [blame] | 59 | |
Jens Axboe | 8010c3b | 2009-09-15 20:04:57 +0200 | [diff] [blame] | 60 | struct list_head list; /* pending work list */ |
Tejun Heo | cc395d7 | 2015-05-22 17:13:58 -0400 | [diff] [blame] | 61 | struct wb_completion *done; /* set if the caller waits */ |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 62 | }; |
| 63 | |
Theodore Ts'o | a2f4870 | 2015-03-17 12:23:19 -0400 | [diff] [blame] | 64 | /* |
Tejun Heo | cc395d7 | 2015-05-22 17:13:58 -0400 | [diff] [blame] | 65 | * If one wants to wait for one or more wb_writeback_works, each work's |
| 66 | * ->done should be set to a wb_completion defined using the following |
| 67 | * macro. Once all work items are issued with wb_queue_work(), the caller |
| 68 | * can wait for the completion of all using wb_wait_for_completion(). Work |
| 69 | * items which are waited upon aren't freed automatically on completion. |
| 70 | */ |
| 71 | #define DEFINE_WB_COMPLETION_ONSTACK(cmpl) \ |
| 72 | struct wb_completion cmpl = { \ |
| 73 | .cnt = ATOMIC_INIT(1), \ |
| 74 | } |
| 75 | |
| 76 | |
| 77 | /* |
Theodore Ts'o | a2f4870 | 2015-03-17 12:23:19 -0400 | [diff] [blame] | 78 | * If an inode is constantly having its pages dirtied, but then the |
| 79 | * updates stop dirtytime_expire_interval seconds in the past, it's |
| 80 | * possible for the worst case time between when an inode has its |
| 81 | * timestamps updated and when they finally get written out to be two |
| 82 | * dirtytime_expire_intervals. We set the default to 12 hours (in |
| 83 | * seconds), which means most of the time inodes will have their |
| 84 | * timestamps written to disk after 12 hours, but in the worst case a |
| 85 | * few inodes might not their timestamps updated for 24 hours. |
| 86 | */ |
| 87 | unsigned int dirtytime_expire_interval = 12 * 60 * 60; |
| 88 | |
Nick Piggin | 7ccf19a | 2010-10-21 11:49:30 +1100 | [diff] [blame] | 89 | static inline struct inode *wb_inode(struct list_head *head) |
| 90 | { |
| 91 | return list_entry(head, struct inode, i_wb_list); |
| 92 | } |
| 93 | |
Wu Fengguang | 15eb77a | 2012-01-17 11:18:56 -0600 | [diff] [blame] | 94 | /* |
| 95 | * Include the creation of the trace points after defining the |
| 96 | * wb_writeback_work structure and inline functions so that the definition |
| 97 | * remains local to this file. |
| 98 | */ |
| 99 | #define CREATE_TRACE_POINTS |
| 100 | #include <trace/events/writeback.h> |
| 101 | |
Steven Whitehouse | 774016b | 2014-02-06 15:47:47 +0000 | [diff] [blame] | 102 | EXPORT_TRACEPOINT_SYMBOL_GPL(wbc_writepage); |
| 103 | |
Tejun Heo | d6c10f1 | 2015-05-22 17:13:45 -0400 | [diff] [blame] | 104 | static bool wb_io_lists_populated(struct bdi_writeback *wb) |
| 105 | { |
| 106 | if (wb_has_dirty_io(wb)) { |
| 107 | return false; |
| 108 | } else { |
| 109 | set_bit(WB_has_dirty_io, &wb->state); |
Tejun Heo | 95a46c6 | 2015-05-22 17:13:47 -0400 | [diff] [blame] | 110 | WARN_ON_ONCE(!wb->avg_write_bandwidth); |
Tejun Heo | 766a9d6 | 2015-05-22 17:13:46 -0400 | [diff] [blame] | 111 | atomic_long_add(wb->avg_write_bandwidth, |
| 112 | &wb->bdi->tot_write_bandwidth); |
Tejun Heo | d6c10f1 | 2015-05-22 17:13:45 -0400 | [diff] [blame] | 113 | return true; |
| 114 | } |
| 115 | } |
| 116 | |
| 117 | static void wb_io_lists_depopulated(struct bdi_writeback *wb) |
| 118 | { |
| 119 | if (wb_has_dirty_io(wb) && list_empty(&wb->b_dirty) && |
Tejun Heo | 766a9d6 | 2015-05-22 17:13:46 -0400 | [diff] [blame] | 120 | list_empty(&wb->b_io) && list_empty(&wb->b_more_io)) { |
Tejun Heo | d6c10f1 | 2015-05-22 17:13:45 -0400 | [diff] [blame] | 121 | clear_bit(WB_has_dirty_io, &wb->state); |
Tejun Heo | 95a46c6 | 2015-05-22 17:13:47 -0400 | [diff] [blame] | 122 | WARN_ON_ONCE(atomic_long_sub_return(wb->avg_write_bandwidth, |
| 123 | &wb->bdi->tot_write_bandwidth) < 0); |
Tejun Heo | 766a9d6 | 2015-05-22 17:13:46 -0400 | [diff] [blame] | 124 | } |
Tejun Heo | d6c10f1 | 2015-05-22 17:13:45 -0400 | [diff] [blame] | 125 | } |
| 126 | |
| 127 | /** |
| 128 | * inode_wb_list_move_locked - move an inode onto a bdi_writeback IO list |
| 129 | * @inode: inode to be moved |
| 130 | * @wb: target bdi_writeback |
| 131 | * @head: one of @wb->b_{dirty|io|more_io} |
| 132 | * |
| 133 | * Move @inode->i_wb_list to @list of @wb and set %WB_has_dirty_io. |
| 134 | * Returns %true if @inode is the first occupant of the !dirty_time IO |
| 135 | * lists; otherwise, %false. |
| 136 | */ |
| 137 | static bool inode_wb_list_move_locked(struct inode *inode, |
| 138 | struct bdi_writeback *wb, |
| 139 | struct list_head *head) |
| 140 | { |
| 141 | assert_spin_locked(&wb->list_lock); |
| 142 | |
| 143 | list_move(&inode->i_wb_list, head); |
| 144 | |
| 145 | /* dirty_time doesn't count as dirty_io until expiration */ |
| 146 | if (head != &wb->b_dirty_time) |
| 147 | return wb_io_lists_populated(wb); |
| 148 | |
| 149 | wb_io_lists_depopulated(wb); |
| 150 | return false; |
| 151 | } |
| 152 | |
| 153 | /** |
| 154 | * inode_wb_list_del_locked - remove an inode from its bdi_writeback IO list |
| 155 | * @inode: inode to be removed |
| 156 | * @wb: bdi_writeback @inode is being removed from |
| 157 | * |
| 158 | * Remove @inode which may be on one of @wb->b_{dirty|io|more_io} lists and |
| 159 | * clear %WB_has_dirty_io if all are empty afterwards. |
| 160 | */ |
| 161 | static void inode_wb_list_del_locked(struct inode *inode, |
| 162 | struct bdi_writeback *wb) |
| 163 | { |
| 164 | assert_spin_locked(&wb->list_lock); |
| 165 | |
| 166 | list_del_init(&inode->i_wb_list); |
| 167 | wb_io_lists_depopulated(wb); |
| 168 | } |
| 169 | |
Tejun Heo | f0054bb | 2015-05-22 17:13:30 -0400 | [diff] [blame] | 170 | static void wb_wakeup(struct bdi_writeback *wb) |
Jan Kara | 5acda9d | 2014-04-03 14:46:23 -0700 | [diff] [blame] | 171 | { |
Tejun Heo | f0054bb | 2015-05-22 17:13:30 -0400 | [diff] [blame] | 172 | spin_lock_bh(&wb->work_lock); |
| 173 | if (test_bit(WB_registered, &wb->state)) |
| 174 | mod_delayed_work(bdi_wq, &wb->dwork, 0); |
| 175 | spin_unlock_bh(&wb->work_lock); |
Jan Kara | 5acda9d | 2014-04-03 14:46:23 -0700 | [diff] [blame] | 176 | } |
| 177 | |
Tejun Heo | f0054bb | 2015-05-22 17:13:30 -0400 | [diff] [blame] | 178 | static void wb_queue_work(struct bdi_writeback *wb, |
| 179 | struct wb_writeback_work *work) |
Jan Kara | 6585027 | 2011-01-13 15:45:44 -0800 | [diff] [blame] | 180 | { |
Tejun Heo | f0054bb | 2015-05-22 17:13:30 -0400 | [diff] [blame] | 181 | trace_writeback_queue(wb->bdi, work); |
Jan Kara | 6585027 | 2011-01-13 15:45:44 -0800 | [diff] [blame] | 182 | |
Tejun Heo | f0054bb | 2015-05-22 17:13:30 -0400 | [diff] [blame] | 183 | spin_lock_bh(&wb->work_lock); |
Tejun Heo | 98754bf | 2015-05-22 17:13:59 -0400 | [diff] [blame] | 184 | if (!test_bit(WB_registered, &wb->state)) { |
| 185 | if (work->single_wait) |
| 186 | work->single_done = 1; |
Jan Kara | 5acda9d | 2014-04-03 14:46:23 -0700 | [diff] [blame] | 187 | goto out_unlock; |
Tejun Heo | 98754bf | 2015-05-22 17:13:59 -0400 | [diff] [blame] | 188 | } |
Tejun Heo | cc395d7 | 2015-05-22 17:13:58 -0400 | [diff] [blame] | 189 | if (work->done) |
| 190 | atomic_inc(&work->done->cnt); |
Tejun Heo | f0054bb | 2015-05-22 17:13:30 -0400 | [diff] [blame] | 191 | list_add_tail(&work->list, &wb->work_list); |
| 192 | mod_delayed_work(bdi_wq, &wb->dwork, 0); |
Jan Kara | 5acda9d | 2014-04-03 14:46:23 -0700 | [diff] [blame] | 193 | out_unlock: |
Tejun Heo | f0054bb | 2015-05-22 17:13:30 -0400 | [diff] [blame] | 194 | spin_unlock_bh(&wb->work_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 195 | } |
| 196 | |
Tejun Heo | cc395d7 | 2015-05-22 17:13:58 -0400 | [diff] [blame] | 197 | /** |
| 198 | * wb_wait_for_completion - wait for completion of bdi_writeback_works |
| 199 | * @bdi: bdi work items were issued to |
| 200 | * @done: target wb_completion |
| 201 | * |
| 202 | * Wait for one or more work items issued to @bdi with their ->done field |
| 203 | * set to @done, which should have been defined with |
| 204 | * DEFINE_WB_COMPLETION_ONSTACK(). This function returns after all such |
| 205 | * work items are completed. Work items which are waited upon aren't freed |
| 206 | * automatically on completion. |
| 207 | */ |
| 208 | static void wb_wait_for_completion(struct backing_dev_info *bdi, |
| 209 | struct wb_completion *done) |
| 210 | { |
| 211 | atomic_dec(&done->cnt); /* put down the initial count */ |
| 212 | wait_event(bdi->wb_waitq, !atomic_read(&done->cnt)); |
| 213 | } |
| 214 | |
Tejun Heo | 703c270 | 2015-05-22 17:13:44 -0400 | [diff] [blame] | 215 | #ifdef CONFIG_CGROUP_WRITEBACK |
| 216 | |
Tejun Heo | 21c6321 | 2015-05-28 14:50:49 -0400 | [diff] [blame^] | 217 | void __inode_attach_wb(struct inode *inode, struct page *page) |
| 218 | { |
| 219 | struct backing_dev_info *bdi = inode_to_bdi(inode); |
| 220 | struct bdi_writeback *wb = NULL; |
| 221 | |
| 222 | if (inode_cgwb_enabled(inode)) { |
| 223 | struct cgroup_subsys_state *memcg_css; |
| 224 | |
| 225 | if (page) { |
| 226 | memcg_css = mem_cgroup_css_from_page(page); |
| 227 | wb = wb_get_create(bdi, memcg_css, GFP_ATOMIC); |
| 228 | } else { |
| 229 | /* must pin memcg_css, see wb_get_create() */ |
| 230 | memcg_css = task_get_css(current, memory_cgrp_id); |
| 231 | wb = wb_get_create(bdi, memcg_css, GFP_ATOMIC); |
| 232 | css_put(memcg_css); |
| 233 | } |
| 234 | } |
| 235 | |
| 236 | if (!wb) |
| 237 | wb = &bdi->wb; |
| 238 | |
| 239 | /* |
| 240 | * There may be multiple instances of this function racing to |
| 241 | * update the same inode. Use cmpxchg() to tell the winner. |
| 242 | */ |
| 243 | if (unlikely(cmpxchg(&inode->i_wb, NULL, wb))) |
| 244 | wb_put(wb); |
| 245 | } |
| 246 | |
Tejun Heo | 703c270 | 2015-05-22 17:13:44 -0400 | [diff] [blame] | 247 | /** |
| 248 | * inode_congested - test whether an inode is congested |
| 249 | * @inode: inode to test for congestion |
| 250 | * @cong_bits: mask of WB_[a]sync_congested bits to test |
| 251 | * |
| 252 | * Tests whether @inode is congested. @cong_bits is the mask of congestion |
| 253 | * bits to test and the return value is the mask of set bits. |
| 254 | * |
| 255 | * If cgroup writeback is enabled for @inode, the congestion state is |
| 256 | * determined by whether the cgwb (cgroup bdi_writeback) for the blkcg |
| 257 | * associated with @inode is congested; otherwise, the root wb's congestion |
| 258 | * state is used. |
| 259 | */ |
| 260 | int inode_congested(struct inode *inode, int cong_bits) |
| 261 | { |
| 262 | if (inode) { |
| 263 | struct bdi_writeback *wb = inode_to_wb(inode); |
| 264 | if (wb) |
| 265 | return wb_congested(wb, cong_bits); |
| 266 | } |
| 267 | |
| 268 | return wb_congested(&inode_to_bdi(inode)->wb, cong_bits); |
| 269 | } |
| 270 | EXPORT_SYMBOL_GPL(inode_congested); |
| 271 | |
Tejun Heo | f2b6512 | 2015-05-22 17:13:55 -0400 | [diff] [blame] | 272 | /** |
Tejun Heo | 98754bf | 2015-05-22 17:13:59 -0400 | [diff] [blame] | 273 | * wb_wait_for_single_work - wait for completion of a single bdi_writeback_work |
| 274 | * @bdi: bdi the work item was issued to |
| 275 | * @work: work item to wait for |
| 276 | * |
| 277 | * Wait for the completion of @work which was issued to one of @bdi's |
| 278 | * bdi_writeback's. The caller must have set @work->single_wait before |
| 279 | * issuing it. This wait operates independently fo |
| 280 | * wb_wait_for_completion() and also disables automatic freeing of @work. |
| 281 | */ |
| 282 | static void wb_wait_for_single_work(struct backing_dev_info *bdi, |
| 283 | struct wb_writeback_work *work) |
| 284 | { |
| 285 | if (WARN_ON_ONCE(!work->single_wait)) |
| 286 | return; |
| 287 | |
| 288 | wait_event(bdi->wb_waitq, work->single_done); |
| 289 | |
| 290 | /* |
| 291 | * Paired with smp_wmb() in wb_do_writeback() and ensures that all |
| 292 | * modifications to @work prior to assertion of ->single_done is |
| 293 | * visible to the caller once this function returns. |
| 294 | */ |
| 295 | smp_rmb(); |
| 296 | } |
| 297 | |
| 298 | /** |
Tejun Heo | f2b6512 | 2015-05-22 17:13:55 -0400 | [diff] [blame] | 299 | * wb_split_bdi_pages - split nr_pages to write according to bandwidth |
| 300 | * @wb: target bdi_writeback to split @nr_pages to |
| 301 | * @nr_pages: number of pages to write for the whole bdi |
| 302 | * |
| 303 | * Split @wb's portion of @nr_pages according to @wb's write bandwidth in |
| 304 | * relation to the total write bandwidth of all wb's w/ dirty inodes on |
| 305 | * @wb->bdi. |
| 306 | */ |
| 307 | static long wb_split_bdi_pages(struct bdi_writeback *wb, long nr_pages) |
| 308 | { |
| 309 | unsigned long this_bw = wb->avg_write_bandwidth; |
| 310 | unsigned long tot_bw = atomic_long_read(&wb->bdi->tot_write_bandwidth); |
| 311 | |
| 312 | if (nr_pages == LONG_MAX) |
| 313 | return LONG_MAX; |
| 314 | |
| 315 | /* |
| 316 | * This may be called on clean wb's and proportional distribution |
| 317 | * may not make sense, just use the original @nr_pages in those |
| 318 | * cases. In general, we wanna err on the side of writing more. |
| 319 | */ |
| 320 | if (!tot_bw || this_bw >= tot_bw) |
| 321 | return nr_pages; |
| 322 | else |
| 323 | return DIV_ROUND_UP_ULL((u64)nr_pages * this_bw, tot_bw); |
| 324 | } |
| 325 | |
Tejun Heo | db12536 | 2015-05-22 17:14:01 -0400 | [diff] [blame] | 326 | /** |
| 327 | * wb_clone_and_queue_work - clone a wb_writeback_work and issue it to a wb |
| 328 | * @wb: target bdi_writeback |
| 329 | * @base_work: source wb_writeback_work |
| 330 | * |
| 331 | * Try to make a clone of @base_work and issue it to @wb. If cloning |
| 332 | * succeeds, %true is returned; otherwise, @base_work is issued directly |
| 333 | * and %false is returned. In the latter case, the caller is required to |
| 334 | * wait for @base_work's completion using wb_wait_for_single_work(). |
| 335 | * |
| 336 | * A clone is auto-freed on completion. @base_work never is. |
| 337 | */ |
| 338 | static bool wb_clone_and_queue_work(struct bdi_writeback *wb, |
| 339 | struct wb_writeback_work *base_work) |
| 340 | { |
| 341 | struct wb_writeback_work *work; |
| 342 | |
| 343 | work = kmalloc(sizeof(*work), GFP_ATOMIC); |
| 344 | if (work) { |
| 345 | *work = *base_work; |
| 346 | work->auto_free = 1; |
| 347 | work->single_wait = 0; |
| 348 | } else { |
| 349 | work = base_work; |
| 350 | work->auto_free = 0; |
| 351 | work->single_wait = 1; |
| 352 | } |
| 353 | work->single_done = 0; |
| 354 | wb_queue_work(wb, work); |
| 355 | return work != base_work; |
| 356 | } |
| 357 | |
| 358 | /** |
| 359 | * bdi_split_work_to_wbs - split a wb_writeback_work to all wb's of a bdi |
| 360 | * @bdi: target backing_dev_info |
| 361 | * @base_work: wb_writeback_work to issue |
| 362 | * @skip_if_busy: skip wb's which already have writeback in progress |
| 363 | * |
| 364 | * Split and issue @base_work to all wb's (bdi_writeback's) of @bdi which |
| 365 | * have dirty inodes. If @base_work->nr_page isn't %LONG_MAX, it's |
| 366 | * distributed to the busy wbs according to each wb's proportion in the |
| 367 | * total active write bandwidth of @bdi. |
| 368 | */ |
| 369 | static void bdi_split_work_to_wbs(struct backing_dev_info *bdi, |
| 370 | struct wb_writeback_work *base_work, |
| 371 | bool skip_if_busy) |
| 372 | { |
| 373 | long nr_pages = base_work->nr_pages; |
| 374 | int next_blkcg_id = 0; |
| 375 | struct bdi_writeback *wb; |
| 376 | struct wb_iter iter; |
| 377 | |
| 378 | might_sleep(); |
| 379 | |
| 380 | if (!bdi_has_dirty_io(bdi)) |
| 381 | return; |
| 382 | restart: |
| 383 | rcu_read_lock(); |
| 384 | bdi_for_each_wb(wb, bdi, &iter, next_blkcg_id) { |
| 385 | if (!wb_has_dirty_io(wb) || |
| 386 | (skip_if_busy && writeback_in_progress(wb))) |
| 387 | continue; |
| 388 | |
| 389 | base_work->nr_pages = wb_split_bdi_pages(wb, nr_pages); |
| 390 | if (!wb_clone_and_queue_work(wb, base_work)) { |
| 391 | next_blkcg_id = wb->blkcg_css->id + 1; |
| 392 | rcu_read_unlock(); |
| 393 | wb_wait_for_single_work(bdi, base_work); |
| 394 | goto restart; |
| 395 | } |
| 396 | } |
| 397 | rcu_read_unlock(); |
| 398 | } |
| 399 | |
Tejun Heo | f2b6512 | 2015-05-22 17:13:55 -0400 | [diff] [blame] | 400 | #else /* CONFIG_CGROUP_WRITEBACK */ |
| 401 | |
| 402 | static long wb_split_bdi_pages(struct bdi_writeback *wb, long nr_pages) |
| 403 | { |
| 404 | return nr_pages; |
| 405 | } |
| 406 | |
Tejun Heo | db12536 | 2015-05-22 17:14:01 -0400 | [diff] [blame] | 407 | static void bdi_split_work_to_wbs(struct backing_dev_info *bdi, |
| 408 | struct wb_writeback_work *base_work, |
| 409 | bool skip_if_busy) |
| 410 | { |
| 411 | might_sleep(); |
| 412 | |
| 413 | if (bdi_has_dirty_io(bdi) && |
| 414 | (!skip_if_busy || !writeback_in_progress(&bdi->wb))) { |
| 415 | base_work->auto_free = 0; |
| 416 | base_work->single_wait = 0; |
| 417 | base_work->single_done = 0; |
| 418 | wb_queue_work(&bdi->wb, base_work); |
| 419 | } |
| 420 | } |
| 421 | |
Tejun Heo | 703c270 | 2015-05-22 17:13:44 -0400 | [diff] [blame] | 422 | #endif /* CONFIG_CGROUP_WRITEBACK */ |
| 423 | |
Tejun Heo | c00ddad | 2015-05-22 17:13:51 -0400 | [diff] [blame] | 424 | void wb_start_writeback(struct bdi_writeback *wb, long nr_pages, |
| 425 | bool range_cyclic, enum wb_reason reason) |
Jens Axboe | b6e5131 | 2009-09-16 15:13:54 +0200 | [diff] [blame] | 426 | { |
Tejun Heo | c00ddad | 2015-05-22 17:13:51 -0400 | [diff] [blame] | 427 | struct wb_writeback_work *work; |
| 428 | |
| 429 | if (!wb_has_dirty_io(wb)) |
| 430 | return; |
| 431 | |
| 432 | /* |
| 433 | * This is WB_SYNC_NONE writeback, so if allocation fails just |
| 434 | * wakeup the thread for old dirty data writeback |
| 435 | */ |
| 436 | work = kzalloc(sizeof(*work), GFP_ATOMIC); |
| 437 | if (!work) { |
| 438 | trace_writeback_nowork(wb->bdi); |
| 439 | wb_wakeup(wb); |
| 440 | return; |
| 441 | } |
| 442 | |
| 443 | work->sync_mode = WB_SYNC_NONE; |
| 444 | work->nr_pages = nr_pages; |
| 445 | work->range_cyclic = range_cyclic; |
| 446 | work->reason = reason; |
Tejun Heo | ac7b19a | 2015-05-22 17:13:57 -0400 | [diff] [blame] | 447 | work->auto_free = 1; |
Tejun Heo | c00ddad | 2015-05-22 17:13:51 -0400 | [diff] [blame] | 448 | |
| 449 | wb_queue_work(wb, work); |
Christoph Hellwig | c544419 | 2010-06-08 18:15:15 +0200 | [diff] [blame] | 450 | } |
Wu Fengguang | d3ddec7 | 2009-09-23 20:33:40 +0800 | [diff] [blame] | 451 | |
Christoph Hellwig | c544419 | 2010-06-08 18:15:15 +0200 | [diff] [blame] | 452 | /** |
Tejun Heo | 9ecf4866 | 2015-05-22 17:13:54 -0400 | [diff] [blame] | 453 | * wb_start_background_writeback - start background writeback |
| 454 | * @wb: bdi_writback to write from |
Christoph Hellwig | c544419 | 2010-06-08 18:15:15 +0200 | [diff] [blame] | 455 | * |
| 456 | * Description: |
Jan Kara | 6585027 | 2011-01-13 15:45:44 -0800 | [diff] [blame] | 457 | * This makes sure WB_SYNC_NONE background writeback happens. When |
Tejun Heo | 9ecf4866 | 2015-05-22 17:13:54 -0400 | [diff] [blame] | 458 | * this function returns, it is only guaranteed that for given wb |
Jan Kara | 6585027 | 2011-01-13 15:45:44 -0800 | [diff] [blame] | 459 | * some IO is happening if we are over background dirty threshold. |
| 460 | * Caller need not hold sb s_umount semaphore. |
Christoph Hellwig | c544419 | 2010-06-08 18:15:15 +0200 | [diff] [blame] | 461 | */ |
Tejun Heo | 9ecf4866 | 2015-05-22 17:13:54 -0400 | [diff] [blame] | 462 | void wb_start_background_writeback(struct bdi_writeback *wb) |
Christoph Hellwig | c544419 | 2010-06-08 18:15:15 +0200 | [diff] [blame] | 463 | { |
Jan Kara | 6585027 | 2011-01-13 15:45:44 -0800 | [diff] [blame] | 464 | /* |
| 465 | * We just wake up the flusher thread. It will perform background |
| 466 | * writeback as soon as there is no other work to do. |
| 467 | */ |
Tejun Heo | 9ecf4866 | 2015-05-22 17:13:54 -0400 | [diff] [blame] | 468 | trace_writeback_wake_background(wb->bdi); |
| 469 | wb_wakeup(wb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 470 | } |
| 471 | |
| 472 | /* |
Dave Chinner | a66979a | 2011-03-22 22:23:41 +1100 | [diff] [blame] | 473 | * Remove the inode from the writeback list it is on. |
| 474 | */ |
| 475 | void inode_wb_list_del(struct inode *inode) |
| 476 | { |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 477 | struct bdi_writeback *wb = inode_to_wb(inode); |
Dave Chinner | a66979a | 2011-03-22 22:23:41 +1100 | [diff] [blame] | 478 | |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 479 | spin_lock(&wb->list_lock); |
Tejun Heo | d6c10f1 | 2015-05-22 17:13:45 -0400 | [diff] [blame] | 480 | inode_wb_list_del_locked(inode, wb); |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 481 | spin_unlock(&wb->list_lock); |
Christoph Hellwig | f758eea | 2011-04-21 18:19:44 -0600 | [diff] [blame] | 482 | } |
Dave Chinner | a66979a | 2011-03-22 22:23:41 +1100 | [diff] [blame] | 483 | |
| 484 | /* |
Andrew Morton | 6610a0b | 2007-10-16 23:30:32 -0700 | [diff] [blame] | 485 | * Redirty an inode: set its when-it-was dirtied timestamp and move it to the |
| 486 | * furthest end of its superblock's dirty-inode list. |
| 487 | * |
| 488 | * 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] | 489 | * 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] | 490 | * the case then the inode must have been redirtied while it was being written |
| 491 | * out and we don't reset its dirtied_when. |
| 492 | */ |
Christoph Hellwig | f758eea | 2011-04-21 18:19:44 -0600 | [diff] [blame] | 493 | static void redirty_tail(struct inode *inode, struct bdi_writeback *wb) |
Andrew Morton | 6610a0b | 2007-10-16 23:30:32 -0700 | [diff] [blame] | 494 | { |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 495 | if (!list_empty(&wb->b_dirty)) { |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 496 | struct inode *tail; |
Andrew Morton | 6610a0b | 2007-10-16 23:30:32 -0700 | [diff] [blame] | 497 | |
Nick Piggin | 7ccf19a | 2010-10-21 11:49:30 +1100 | [diff] [blame] | 498 | tail = wb_inode(wb->b_dirty.next); |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 499 | if (time_before(inode->dirtied_when, tail->dirtied_when)) |
Andrew Morton | 6610a0b | 2007-10-16 23:30:32 -0700 | [diff] [blame] | 500 | inode->dirtied_when = jiffies; |
| 501 | } |
Tejun Heo | d6c10f1 | 2015-05-22 17:13:45 -0400 | [diff] [blame] | 502 | inode_wb_list_move_locked(inode, wb, &wb->b_dirty); |
Andrew Morton | 6610a0b | 2007-10-16 23:30:32 -0700 | [diff] [blame] | 503 | } |
| 504 | |
| 505 | /* |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 506 | * requeue inode for re-scanning after bdi->b_io list is exhausted. |
Andrew Morton | c986d1e | 2007-10-16 23:30:34 -0700 | [diff] [blame] | 507 | */ |
Christoph Hellwig | f758eea | 2011-04-21 18:19:44 -0600 | [diff] [blame] | 508 | static void requeue_io(struct inode *inode, struct bdi_writeback *wb) |
Andrew Morton | c986d1e | 2007-10-16 23:30:34 -0700 | [diff] [blame] | 509 | { |
Tejun Heo | d6c10f1 | 2015-05-22 17:13:45 -0400 | [diff] [blame] | 510 | inode_wb_list_move_locked(inode, wb, &wb->b_more_io); |
Andrew Morton | c986d1e | 2007-10-16 23:30:34 -0700 | [diff] [blame] | 511 | } |
| 512 | |
Joern Engel | 1c0eeaf | 2007-10-16 23:30:44 -0700 | [diff] [blame] | 513 | static void inode_sync_complete(struct inode *inode) |
| 514 | { |
Jan Kara | 365b94ae | 2012-05-03 14:47:55 +0200 | [diff] [blame] | 515 | inode->i_state &= ~I_SYNC; |
Jan Kara | 4eff96d | 2012-11-26 16:29:51 -0800 | [diff] [blame] | 516 | /* If inode is clean an unused, put it into LRU now... */ |
| 517 | inode_add_lru(inode); |
Jan Kara | 365b94ae | 2012-05-03 14:47:55 +0200 | [diff] [blame] | 518 | /* Waiters must see I_SYNC cleared before being woken up */ |
Joern Engel | 1c0eeaf | 2007-10-16 23:30:44 -0700 | [diff] [blame] | 519 | smp_mb(); |
| 520 | wake_up_bit(&inode->i_state, __I_SYNC); |
| 521 | } |
| 522 | |
Jeff Layton | d2caa3c5 | 2009-04-02 16:56:37 -0700 | [diff] [blame] | 523 | static bool inode_dirtied_after(struct inode *inode, unsigned long t) |
| 524 | { |
| 525 | bool ret = time_after(inode->dirtied_when, t); |
| 526 | #ifndef CONFIG_64BIT |
| 527 | /* |
| 528 | * For inodes being constantly redirtied, dirtied_when can get stuck. |
| 529 | * It _appears_ to be in the future, but is actually in distant past. |
| 530 | * This test is necessary to prevent such wrapped-around relative times |
Jens Axboe | 5b0830c | 2009-09-23 19:37:09 +0200 | [diff] [blame] | 531 | * from permanently stopping the whole bdi writeback. |
Jeff Layton | d2caa3c5 | 2009-04-02 16:56:37 -0700 | [diff] [blame] | 532 | */ |
| 533 | ret = ret && time_before_eq(inode->dirtied_when, jiffies); |
| 534 | #endif |
| 535 | return ret; |
| 536 | } |
| 537 | |
Theodore Ts'o | 0ae45f6 | 2015-02-02 00:37:00 -0500 | [diff] [blame] | 538 | #define EXPIRE_DIRTY_ATIME 0x0001 |
| 539 | |
Andrew Morton | c986d1e | 2007-10-16 23:30:34 -0700 | [diff] [blame] | 540 | /* |
Wang Sheng-Hui | 0e2f2b2 | 2012-09-11 08:28:18 +0800 | [diff] [blame] | 541 | * Move expired (dirtied before work->older_than_this) dirty inodes from |
Jan Kara | 697e6fe | 2012-03-09 07:26:22 -0800 | [diff] [blame] | 542 | * @delaying_queue to @dispatch_queue. |
Fengguang Wu | 2c13657 | 2007-10-16 23:30:39 -0700 | [diff] [blame] | 543 | */ |
Wu Fengguang | e84d0a4 | 2011-04-23 12:27:27 -0600 | [diff] [blame] | 544 | static int move_expired_inodes(struct list_head *delaying_queue, |
Fengguang Wu | 2c13657 | 2007-10-16 23:30:39 -0700 | [diff] [blame] | 545 | struct list_head *dispatch_queue, |
Theodore Ts'o | 0ae45f6 | 2015-02-02 00:37:00 -0500 | [diff] [blame] | 546 | int flags, |
Curt Wohlgemuth | ad4e38d | 2011-10-07 21:51:56 -0600 | [diff] [blame] | 547 | struct wb_writeback_work *work) |
Fengguang Wu | 2c13657 | 2007-10-16 23:30:39 -0700 | [diff] [blame] | 548 | { |
Theodore Ts'o | 0ae45f6 | 2015-02-02 00:37:00 -0500 | [diff] [blame] | 549 | unsigned long *older_than_this = NULL; |
| 550 | unsigned long expire_time; |
Shaohua Li | 5c03449 | 2009-09-24 14:42:33 +0200 | [diff] [blame] | 551 | LIST_HEAD(tmp); |
| 552 | struct list_head *pos, *node; |
Jens Axboe | cf13730 | 2009-09-24 15:12:57 +0200 | [diff] [blame] | 553 | struct super_block *sb = NULL; |
Shaohua Li | 5c03449 | 2009-09-24 14:42:33 +0200 | [diff] [blame] | 554 | struct inode *inode; |
Jens Axboe | cf13730 | 2009-09-24 15:12:57 +0200 | [diff] [blame] | 555 | int do_sb_sort = 0; |
Wu Fengguang | e84d0a4 | 2011-04-23 12:27:27 -0600 | [diff] [blame] | 556 | int moved = 0; |
Shaohua Li | 5c03449 | 2009-09-24 14:42:33 +0200 | [diff] [blame] | 557 | |
Theodore Ts'o | 0ae45f6 | 2015-02-02 00:37:00 -0500 | [diff] [blame] | 558 | if ((flags & EXPIRE_DIRTY_ATIME) == 0) |
| 559 | older_than_this = work->older_than_this; |
Theodore Ts'o | a2f4870 | 2015-03-17 12:23:19 -0400 | [diff] [blame] | 560 | else if (!work->for_sync) { |
| 561 | expire_time = jiffies - (dirtytime_expire_interval * HZ); |
Theodore Ts'o | 0ae45f6 | 2015-02-02 00:37:00 -0500 | [diff] [blame] | 562 | older_than_this = &expire_time; |
| 563 | } |
Fengguang Wu | 2c13657 | 2007-10-16 23:30:39 -0700 | [diff] [blame] | 564 | while (!list_empty(delaying_queue)) { |
Nick Piggin | 7ccf19a | 2010-10-21 11:49:30 +1100 | [diff] [blame] | 565 | inode = wb_inode(delaying_queue->prev); |
Theodore Ts'o | 0ae45f6 | 2015-02-02 00:37:00 -0500 | [diff] [blame] | 566 | if (older_than_this && |
| 567 | inode_dirtied_after(inode, *older_than_this)) |
Fengguang Wu | 2c13657 | 2007-10-16 23:30:39 -0700 | [diff] [blame] | 568 | break; |
Jan Kara | a885599 | 2013-07-09 22:36:45 +0800 | [diff] [blame] | 569 | list_move(&inode->i_wb_list, &tmp); |
| 570 | moved++; |
Theodore Ts'o | 0ae45f6 | 2015-02-02 00:37:00 -0500 | [diff] [blame] | 571 | if (flags & EXPIRE_DIRTY_ATIME) |
| 572 | set_bit(__I_DIRTY_TIME_EXPIRED, &inode->i_state); |
Jan Kara | a885599 | 2013-07-09 22:36:45 +0800 | [diff] [blame] | 573 | if (sb_is_blkdev_sb(inode->i_sb)) |
| 574 | continue; |
Jens Axboe | cf13730 | 2009-09-24 15:12:57 +0200 | [diff] [blame] | 575 | if (sb && sb != inode->i_sb) |
| 576 | do_sb_sort = 1; |
| 577 | sb = inode->i_sb; |
Shaohua Li | 5c03449 | 2009-09-24 14:42:33 +0200 | [diff] [blame] | 578 | } |
| 579 | |
Jens Axboe | cf13730 | 2009-09-24 15:12:57 +0200 | [diff] [blame] | 580 | /* just one sb in list, splice to dispatch_queue and we're done */ |
| 581 | if (!do_sb_sort) { |
| 582 | list_splice(&tmp, dispatch_queue); |
Wu Fengguang | e84d0a4 | 2011-04-23 12:27:27 -0600 | [diff] [blame] | 583 | goto out; |
Jens Axboe | cf13730 | 2009-09-24 15:12:57 +0200 | [diff] [blame] | 584 | } |
| 585 | |
Shaohua Li | 5c03449 | 2009-09-24 14:42:33 +0200 | [diff] [blame] | 586 | /* Move inodes from one superblock together */ |
| 587 | while (!list_empty(&tmp)) { |
Nick Piggin | 7ccf19a | 2010-10-21 11:49:30 +1100 | [diff] [blame] | 588 | sb = wb_inode(tmp.prev)->i_sb; |
Shaohua Li | 5c03449 | 2009-09-24 14:42:33 +0200 | [diff] [blame] | 589 | list_for_each_prev_safe(pos, node, &tmp) { |
Nick Piggin | 7ccf19a | 2010-10-21 11:49:30 +1100 | [diff] [blame] | 590 | inode = wb_inode(pos); |
Shaohua Li | 5c03449 | 2009-09-24 14:42:33 +0200 | [diff] [blame] | 591 | if (inode->i_sb == sb) |
Nick Piggin | 7ccf19a | 2010-10-21 11:49:30 +1100 | [diff] [blame] | 592 | list_move(&inode->i_wb_list, dispatch_queue); |
Shaohua Li | 5c03449 | 2009-09-24 14:42:33 +0200 | [diff] [blame] | 593 | } |
Fengguang Wu | 2c13657 | 2007-10-16 23:30:39 -0700 | [diff] [blame] | 594 | } |
Wu Fengguang | e84d0a4 | 2011-04-23 12:27:27 -0600 | [diff] [blame] | 595 | out: |
| 596 | return moved; |
Fengguang Wu | 2c13657 | 2007-10-16 23:30:39 -0700 | [diff] [blame] | 597 | } |
| 598 | |
| 599 | /* |
| 600 | * Queue all expired dirty inodes for io, eldest first. |
Wu Fengguang | 4ea879b | 2010-08-11 14:17:42 -0700 | [diff] [blame] | 601 | * Before |
| 602 | * newly dirtied b_dirty b_io b_more_io |
| 603 | * =============> gf edc BA |
| 604 | * After |
| 605 | * newly dirtied b_dirty b_io b_more_io |
| 606 | * =============> g fBAedc |
| 607 | * | |
| 608 | * +--> dequeue for IO |
Fengguang Wu | 2c13657 | 2007-10-16 23:30:39 -0700 | [diff] [blame] | 609 | */ |
Curt Wohlgemuth | ad4e38d | 2011-10-07 21:51:56 -0600 | [diff] [blame] | 610 | 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] | 611 | { |
Wu Fengguang | e84d0a4 | 2011-04-23 12:27:27 -0600 | [diff] [blame] | 612 | int moved; |
Theodore Ts'o | 0ae45f6 | 2015-02-02 00:37:00 -0500 | [diff] [blame] | 613 | |
Christoph Hellwig | f758eea | 2011-04-21 18:19:44 -0600 | [diff] [blame] | 614 | assert_spin_locked(&wb->list_lock); |
Wu Fengguang | 4ea879b | 2010-08-11 14:17:42 -0700 | [diff] [blame] | 615 | list_splice_init(&wb->b_more_io, &wb->b_io); |
Theodore Ts'o | 0ae45f6 | 2015-02-02 00:37:00 -0500 | [diff] [blame] | 616 | moved = move_expired_inodes(&wb->b_dirty, &wb->b_io, 0, work); |
| 617 | moved += move_expired_inodes(&wb->b_dirty_time, &wb->b_io, |
| 618 | EXPIRE_DIRTY_ATIME, work); |
Tejun Heo | d6c10f1 | 2015-05-22 17:13:45 -0400 | [diff] [blame] | 619 | if (moved) |
| 620 | wb_io_lists_populated(wb); |
Curt Wohlgemuth | ad4e38d | 2011-10-07 21:51:56 -0600 | [diff] [blame] | 621 | trace_writeback_queue_io(wb, work, moved); |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 622 | } |
| 623 | |
Christoph Hellwig | a9185b4 | 2010-03-05 09:21:37 +0100 | [diff] [blame] | 624 | static int write_inode(struct inode *inode, struct writeback_control *wbc) |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 625 | { |
Tejun Heo | 9fb0a7d | 2013-01-11 13:06:37 -0800 | [diff] [blame] | 626 | int ret; |
| 627 | |
| 628 | if (inode->i_sb->s_op->write_inode && !is_bad_inode(inode)) { |
| 629 | trace_writeback_write_inode_start(inode, wbc); |
| 630 | ret = inode->i_sb->s_op->write_inode(inode, wbc); |
| 631 | trace_writeback_write_inode(inode, wbc); |
| 632 | return ret; |
| 633 | } |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 634 | return 0; |
Fengguang Wu | 2c13657 | 2007-10-16 23:30:39 -0700 | [diff] [blame] | 635 | } |
| 636 | |
| 637 | /* |
Jan Kara | 169ebd9 | 2012-05-03 14:48:03 +0200 | [diff] [blame] | 638 | * Wait for writeback on an inode to complete. Called with i_lock held. |
| 639 | * 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] | 640 | */ |
Jan Kara | 169ebd9 | 2012-05-03 14:48:03 +0200 | [diff] [blame] | 641 | static void __inode_wait_for_writeback(struct inode *inode) |
| 642 | __releases(inode->i_lock) |
| 643 | __acquires(inode->i_lock) |
Christoph Hellwig | 01c0319 | 2009-06-08 13:35:40 +0200 | [diff] [blame] | 644 | { |
| 645 | DEFINE_WAIT_BIT(wq, &inode->i_state, __I_SYNC); |
| 646 | wait_queue_head_t *wqh; |
| 647 | |
| 648 | wqh = bit_waitqueue(&inode->i_state, __I_SYNC); |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 649 | while (inode->i_state & I_SYNC) { |
| 650 | spin_unlock(&inode->i_lock); |
NeilBrown | 7431620 | 2014-07-07 15:16:04 +1000 | [diff] [blame] | 651 | __wait_on_bit(wqh, &wq, bit_wait, |
| 652 | TASK_UNINTERRUPTIBLE); |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 653 | spin_lock(&inode->i_lock); |
Richard Kennedy | 58a9d3d8 | 2010-05-24 14:32:38 -0700 | [diff] [blame] | 654 | } |
Christoph Hellwig | 01c0319 | 2009-06-08 13:35:40 +0200 | [diff] [blame] | 655 | } |
| 656 | |
| 657 | /* |
Jan Kara | 169ebd9 | 2012-05-03 14:48:03 +0200 | [diff] [blame] | 658 | * Wait for writeback on an inode to complete. Caller must have inode pinned. |
| 659 | */ |
| 660 | void inode_wait_for_writeback(struct inode *inode) |
| 661 | { |
| 662 | spin_lock(&inode->i_lock); |
| 663 | __inode_wait_for_writeback(inode); |
| 664 | spin_unlock(&inode->i_lock); |
| 665 | } |
| 666 | |
| 667 | /* |
| 668 | * Sleep until I_SYNC is cleared. This function must be called with i_lock |
| 669 | * held and drops it. It is aimed for callers not holding any inode reference |
| 670 | * so once i_lock is dropped, inode can go away. |
| 671 | */ |
| 672 | static void inode_sleep_on_writeback(struct inode *inode) |
| 673 | __releases(inode->i_lock) |
| 674 | { |
| 675 | DEFINE_WAIT(wait); |
| 676 | wait_queue_head_t *wqh = bit_waitqueue(&inode->i_state, __I_SYNC); |
| 677 | int sleep; |
| 678 | |
| 679 | prepare_to_wait(wqh, &wait, TASK_UNINTERRUPTIBLE); |
| 680 | sleep = inode->i_state & I_SYNC; |
| 681 | spin_unlock(&inode->i_lock); |
| 682 | if (sleep) |
| 683 | schedule(); |
| 684 | finish_wait(wqh, &wait); |
| 685 | } |
| 686 | |
| 687 | /* |
Jan Kara | ccb26b5 | 2012-05-03 14:47:58 +0200 | [diff] [blame] | 688 | * Find proper writeback list for the inode depending on its current state and |
| 689 | * possibly also change of its state while we were doing writeback. Here we |
| 690 | * handle things such as livelock prevention or fairness of writeback among |
| 691 | * inodes. This function can be called only by flusher thread - noone else |
| 692 | * processes all inodes in writeback lists and requeueing inodes behind flusher |
| 693 | * thread's back can have unexpected consequences. |
| 694 | */ |
| 695 | static void requeue_inode(struct inode *inode, struct bdi_writeback *wb, |
| 696 | struct writeback_control *wbc) |
| 697 | { |
| 698 | if (inode->i_state & I_FREEING) |
| 699 | return; |
| 700 | |
| 701 | /* |
| 702 | * Sync livelock prevention. Each inode is tagged and synced in one |
| 703 | * shot. If still dirty, it will be redirty_tail()'ed below. Update |
| 704 | * the dirty time to prevent enqueue and sync it again. |
| 705 | */ |
| 706 | if ((inode->i_state & I_DIRTY) && |
| 707 | (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)) |
| 708 | inode->dirtied_when = jiffies; |
| 709 | |
Jan Kara | 4f8ad65 | 2012-05-03 14:48:00 +0200 | [diff] [blame] | 710 | if (wbc->pages_skipped) { |
| 711 | /* |
| 712 | * writeback is not making progress due to locked |
| 713 | * buffers. Skip this inode for now. |
| 714 | */ |
| 715 | redirty_tail(inode, wb); |
| 716 | return; |
| 717 | } |
| 718 | |
Jan Kara | ccb26b5 | 2012-05-03 14:47:58 +0200 | [diff] [blame] | 719 | if (mapping_tagged(inode->i_mapping, PAGECACHE_TAG_DIRTY)) { |
| 720 | /* |
| 721 | * We didn't write back all the pages. nfs_writepages() |
| 722 | * sometimes bales out without doing anything. |
| 723 | */ |
| 724 | if (wbc->nr_to_write <= 0) { |
| 725 | /* Slice used up. Queue for next turn. */ |
| 726 | requeue_io(inode, wb); |
| 727 | } else { |
| 728 | /* |
| 729 | * Writeback blocked by something other than |
| 730 | * congestion. Delay the inode for some time to |
| 731 | * avoid spinning on the CPU (100% iowait) |
| 732 | * retrying writeback of the dirty page/inode |
| 733 | * that cannot be performed immediately. |
| 734 | */ |
| 735 | redirty_tail(inode, wb); |
| 736 | } |
| 737 | } else if (inode->i_state & I_DIRTY) { |
| 738 | /* |
| 739 | * Filesystems can dirty the inode during writeback operations, |
| 740 | * such as delayed allocation during submission or metadata |
| 741 | * updates after data IO completion. |
| 742 | */ |
| 743 | redirty_tail(inode, wb); |
Theodore Ts'o | 0ae45f6 | 2015-02-02 00:37:00 -0500 | [diff] [blame] | 744 | } else if (inode->i_state & I_DIRTY_TIME) { |
Theodore Ts'o | a2f4870 | 2015-03-17 12:23:19 -0400 | [diff] [blame] | 745 | inode->dirtied_when = jiffies; |
Tejun Heo | d6c10f1 | 2015-05-22 17:13:45 -0400 | [diff] [blame] | 746 | inode_wb_list_move_locked(inode, wb, &wb->b_dirty_time); |
Jan Kara | ccb26b5 | 2012-05-03 14:47:58 +0200 | [diff] [blame] | 747 | } else { |
| 748 | /* The inode is clean. Remove from writeback lists. */ |
Tejun Heo | d6c10f1 | 2015-05-22 17:13:45 -0400 | [diff] [blame] | 749 | inode_wb_list_del_locked(inode, wb); |
Jan Kara | ccb26b5 | 2012-05-03 14:47:58 +0200 | [diff] [blame] | 750 | } |
| 751 | } |
| 752 | |
| 753 | /* |
Jan Kara | 4f8ad65 | 2012-05-03 14:48:00 +0200 | [diff] [blame] | 754 | * Write out an inode and its dirty pages. Do not update the writeback list |
| 755 | * linkage. That is left to the caller. The caller is also responsible for |
| 756 | * setting I_SYNC flag and calling inode_sync_complete() to clear it. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 757 | */ |
| 758 | static int |
Yan Hong | cd8ed2a | 2012-10-08 16:33:45 -0700 | [diff] [blame] | 759 | __writeback_single_inode(struct inode *inode, struct writeback_control *wbc) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 760 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 761 | struct address_space *mapping = inode->i_mapping; |
Wu Fengguang | 251d6a4 | 2010-12-01 17:33:37 -0600 | [diff] [blame] | 762 | long nr_to_write = wbc->nr_to_write; |
Christoph Hellwig | 01c0319 | 2009-06-08 13:35:40 +0200 | [diff] [blame] | 763 | unsigned dirty; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 764 | int ret; |
| 765 | |
Jan Kara | 4f8ad65 | 2012-05-03 14:48:00 +0200 | [diff] [blame] | 766 | WARN_ON(!(inode->i_state & I_SYNC)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 767 | |
Tejun Heo | 9fb0a7d | 2013-01-11 13:06:37 -0800 | [diff] [blame] | 768 | trace_writeback_single_inode_start(inode, wbc, nr_to_write); |
| 769 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 770 | ret = do_writepages(mapping, wbc); |
| 771 | |
Christoph Hellwig | 26821ed | 2010-03-05 09:21:21 +0100 | [diff] [blame] | 772 | /* |
| 773 | * Make sure to wait on the data before writing out the metadata. |
| 774 | * This is important for filesystems that modify metadata on data |
Dave Chinner | 7747bd4 | 2013-07-02 22:38:35 +1000 | [diff] [blame] | 775 | * I/O completion. We don't do it for sync(2) writeback because it has a |
| 776 | * separate, external IO completion path and ->sync_fs for guaranteeing |
| 777 | * inode metadata is written back correctly. |
Christoph Hellwig | 26821ed | 2010-03-05 09:21:21 +0100 | [diff] [blame] | 778 | */ |
Dave Chinner | 7747bd4 | 2013-07-02 22:38:35 +1000 | [diff] [blame] | 779 | if (wbc->sync_mode == WB_SYNC_ALL && !wbc->for_sync) { |
Christoph Hellwig | 26821ed | 2010-03-05 09:21:21 +0100 | [diff] [blame] | 780 | int err = filemap_fdatawait(mapping); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 781 | if (ret == 0) |
| 782 | ret = err; |
| 783 | } |
| 784 | |
Dmitry Monakhov | 5547e8a | 2010-05-07 13:35:44 +0400 | [diff] [blame] | 785 | /* |
| 786 | * Some filesystems may redirty the inode during the writeback |
| 787 | * due to delalloc, clear dirty metadata flags right before |
| 788 | * write_inode() |
| 789 | */ |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 790 | spin_lock(&inode->i_lock); |
Tejun Heo | 9c6ac78 | 2014-10-24 15:38:21 -0400 | [diff] [blame] | 791 | |
Dmitry Monakhov | 5547e8a | 2010-05-07 13:35:44 +0400 | [diff] [blame] | 792 | dirty = inode->i_state & I_DIRTY; |
Theodore Ts'o | a2f4870 | 2015-03-17 12:23:19 -0400 | [diff] [blame] | 793 | if (inode->i_state & I_DIRTY_TIME) { |
| 794 | if ((dirty & (I_DIRTY_SYNC | I_DIRTY_DATASYNC)) || |
| 795 | unlikely(inode->i_state & I_DIRTY_TIME_EXPIRED) || |
| 796 | unlikely(time_after(jiffies, |
| 797 | (inode->dirtied_time_when + |
| 798 | dirtytime_expire_interval * HZ)))) { |
| 799 | dirty |= I_DIRTY_TIME | I_DIRTY_TIME_EXPIRED; |
| 800 | trace_writeback_lazytime(inode); |
| 801 | } |
| 802 | } else |
| 803 | inode->i_state &= ~I_DIRTY_TIME_EXPIRED; |
Theodore Ts'o | 0ae45f6 | 2015-02-02 00:37:00 -0500 | [diff] [blame] | 804 | inode->i_state &= ~dirty; |
Tejun Heo | 9c6ac78 | 2014-10-24 15:38:21 -0400 | [diff] [blame] | 805 | |
| 806 | /* |
| 807 | * Paired with smp_mb() in __mark_inode_dirty(). This allows |
| 808 | * __mark_inode_dirty() to test i_state without grabbing i_lock - |
| 809 | * either they see the I_DIRTY bits cleared or we see the dirtied |
| 810 | * inode. |
| 811 | * |
| 812 | * I_DIRTY_PAGES is always cleared together above even if @mapping |
| 813 | * still has dirty pages. The flag is reinstated after smp_mb() if |
| 814 | * necessary. This guarantees that either __mark_inode_dirty() |
| 815 | * sees clear I_DIRTY_PAGES or we see PAGECACHE_TAG_DIRTY. |
| 816 | */ |
| 817 | smp_mb(); |
| 818 | |
| 819 | if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) |
| 820 | inode->i_state |= I_DIRTY_PAGES; |
| 821 | |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 822 | spin_unlock(&inode->i_lock); |
Tejun Heo | 9c6ac78 | 2014-10-24 15:38:21 -0400 | [diff] [blame] | 823 | |
Theodore Ts'o | 0ae45f6 | 2015-02-02 00:37:00 -0500 | [diff] [blame] | 824 | if (dirty & I_DIRTY_TIME) |
| 825 | mark_inode_dirty_sync(inode); |
Christoph Hellwig | 26821ed | 2010-03-05 09:21:21 +0100 | [diff] [blame] | 826 | /* Don't write the inode if only I_DIRTY_PAGES was set */ |
Theodore Ts'o | 0ae45f6 | 2015-02-02 00:37:00 -0500 | [diff] [blame] | 827 | if (dirty & ~I_DIRTY_PAGES) { |
Christoph Hellwig | a9185b4 | 2010-03-05 09:21:37 +0100 | [diff] [blame] | 828 | int err = write_inode(inode, wbc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 829 | if (ret == 0) |
| 830 | ret = err; |
| 831 | } |
Jan Kara | 4f8ad65 | 2012-05-03 14:48:00 +0200 | [diff] [blame] | 832 | trace_writeback_single_inode(inode, wbc, nr_to_write); |
| 833 | return ret; |
| 834 | } |
| 835 | |
| 836 | /* |
| 837 | * Write out an inode's dirty pages. Either the caller has an active reference |
| 838 | * on the inode or the inode has I_WILL_FREE set. |
| 839 | * |
| 840 | * This function is designed to be called for writing back one inode which |
| 841 | * we go e.g. from filesystem. Flusher thread uses __writeback_single_inode() |
| 842 | * and does more profound writeback list handling in writeback_sb_inodes(). |
| 843 | */ |
| 844 | static int |
| 845 | writeback_single_inode(struct inode *inode, struct bdi_writeback *wb, |
| 846 | struct writeback_control *wbc) |
| 847 | { |
| 848 | int ret = 0; |
| 849 | |
| 850 | spin_lock(&inode->i_lock); |
| 851 | if (!atomic_read(&inode->i_count)) |
| 852 | WARN_ON(!(inode->i_state & (I_WILL_FREE|I_FREEING))); |
| 853 | else |
| 854 | WARN_ON(inode->i_state & I_WILL_FREE); |
| 855 | |
| 856 | if (inode->i_state & I_SYNC) { |
| 857 | if (wbc->sync_mode != WB_SYNC_ALL) |
| 858 | goto out; |
| 859 | /* |
Jan Kara | 169ebd9 | 2012-05-03 14:48:03 +0200 | [diff] [blame] | 860 | * It's a data-integrity sync. We must wait. Since callers hold |
| 861 | * inode reference or inode has I_WILL_FREE set, it cannot go |
| 862 | * away under us. |
Jan Kara | 4f8ad65 | 2012-05-03 14:48:00 +0200 | [diff] [blame] | 863 | */ |
Jan Kara | 169ebd9 | 2012-05-03 14:48:03 +0200 | [diff] [blame] | 864 | __inode_wait_for_writeback(inode); |
Jan Kara | 4f8ad65 | 2012-05-03 14:48:00 +0200 | [diff] [blame] | 865 | } |
| 866 | WARN_ON(inode->i_state & I_SYNC); |
| 867 | /* |
Jan Kara | f9b0e05 | 2013-12-14 04:21:26 +0800 | [diff] [blame] | 868 | * Skip inode if it is clean and we have no outstanding writeback in |
| 869 | * WB_SYNC_ALL mode. We don't want to mess with writeback lists in this |
| 870 | * function since flusher thread may be doing for example sync in |
| 871 | * parallel and if we move the inode, it could get skipped. So here we |
| 872 | * make sure inode is on some writeback list and leave it there unless |
| 873 | * we have completely cleaned the inode. |
Jan Kara | 4f8ad65 | 2012-05-03 14:48:00 +0200 | [diff] [blame] | 874 | */ |
Theodore Ts'o | 0ae45f6 | 2015-02-02 00:37:00 -0500 | [diff] [blame] | 875 | if (!(inode->i_state & I_DIRTY_ALL) && |
Jan Kara | f9b0e05 | 2013-12-14 04:21:26 +0800 | [diff] [blame] | 876 | (wbc->sync_mode != WB_SYNC_ALL || |
| 877 | !mapping_tagged(inode->i_mapping, PAGECACHE_TAG_WRITEBACK))) |
Jan Kara | 4f8ad65 | 2012-05-03 14:48:00 +0200 | [diff] [blame] | 878 | goto out; |
| 879 | inode->i_state |= I_SYNC; |
| 880 | spin_unlock(&inode->i_lock); |
| 881 | |
Yan Hong | cd8ed2a | 2012-10-08 16:33:45 -0700 | [diff] [blame] | 882 | ret = __writeback_single_inode(inode, wbc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 883 | |
Christoph Hellwig | f758eea | 2011-04-21 18:19:44 -0600 | [diff] [blame] | 884 | spin_lock(&wb->list_lock); |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 885 | spin_lock(&inode->i_lock); |
Jan Kara | 4f8ad65 | 2012-05-03 14:48:00 +0200 | [diff] [blame] | 886 | /* |
| 887 | * If inode is clean, remove it from writeback lists. Otherwise don't |
| 888 | * touch it. See comment above for explanation. |
| 889 | */ |
Theodore Ts'o | 0ae45f6 | 2015-02-02 00:37:00 -0500 | [diff] [blame] | 890 | if (!(inode->i_state & I_DIRTY_ALL)) |
Tejun Heo | d6c10f1 | 2015-05-22 17:13:45 -0400 | [diff] [blame] | 891 | inode_wb_list_del_locked(inode, wb); |
Jan Kara | 4f8ad65 | 2012-05-03 14:48:00 +0200 | [diff] [blame] | 892 | spin_unlock(&wb->list_lock); |
Joern Engel | 1c0eeaf | 2007-10-16 23:30:44 -0700 | [diff] [blame] | 893 | inode_sync_complete(inode); |
Jan Kara | 4f8ad65 | 2012-05-03 14:48:00 +0200 | [diff] [blame] | 894 | out: |
| 895 | spin_unlock(&inode->i_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 896 | return ret; |
| 897 | } |
| 898 | |
Tejun Heo | a88a341 | 2015-05-22 17:13:28 -0400 | [diff] [blame] | 899 | static long writeback_chunk_size(struct bdi_writeback *wb, |
Wu Fengguang | 1a12d8b | 2010-08-29 13:28:09 -0600 | [diff] [blame] | 900 | struct wb_writeback_work *work) |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 901 | { |
| 902 | long pages; |
| 903 | |
| 904 | /* |
| 905 | * WB_SYNC_ALL mode does livelock avoidance by syncing dirty |
| 906 | * inodes/pages in one big loop. Setting wbc.nr_to_write=LONG_MAX |
| 907 | * here avoids calling into writeback_inodes_wb() more than once. |
| 908 | * |
| 909 | * The intended call sequence for WB_SYNC_ALL writeback is: |
| 910 | * |
| 911 | * wb_writeback() |
| 912 | * writeback_sb_inodes() <== called only once |
| 913 | * write_cache_pages() <== called once for each inode |
| 914 | * (quickly) tag currently dirty pages |
| 915 | * (maybe slowly) sync all tagged pages |
| 916 | */ |
| 917 | if (work->sync_mode == WB_SYNC_ALL || work->tagged_writepages) |
| 918 | pages = LONG_MAX; |
Wu Fengguang | 1a12d8b | 2010-08-29 13:28:09 -0600 | [diff] [blame] | 919 | else { |
Tejun Heo | a88a341 | 2015-05-22 17:13:28 -0400 | [diff] [blame] | 920 | pages = min(wb->avg_write_bandwidth / 2, |
Tejun Heo | dcc25ae | 2015-05-22 18:23:22 -0400 | [diff] [blame] | 921 | global_wb_domain.dirty_limit / DIRTY_SCOPE); |
Wu Fengguang | 1a12d8b | 2010-08-29 13:28:09 -0600 | [diff] [blame] | 922 | pages = min(pages, work->nr_pages); |
| 923 | pages = round_down(pages + MIN_WRITEBACK_PAGES, |
| 924 | MIN_WRITEBACK_PAGES); |
| 925 | } |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 926 | |
| 927 | return pages; |
| 928 | } |
| 929 | |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 930 | /* |
Edward Shishkin | f11c9c5 | 2010-03-11 14:09:47 -0800 | [diff] [blame] | 931 | * Write a portion of b_io inodes which belong to @sb. |
Christoph Hellwig | edadfb1 | 2010-06-10 12:07:54 +0200 | [diff] [blame] | 932 | * |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 933 | * Return the number of pages and/or inodes written. |
Edward Shishkin | f11c9c5 | 2010-03-11 14:09:47 -0800 | [diff] [blame] | 934 | */ |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 935 | static long writeback_sb_inodes(struct super_block *sb, |
| 936 | struct bdi_writeback *wb, |
| 937 | struct wb_writeback_work *work) |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 938 | { |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 939 | struct writeback_control wbc = { |
| 940 | .sync_mode = work->sync_mode, |
| 941 | .tagged_writepages = work->tagged_writepages, |
| 942 | .for_kupdate = work->for_kupdate, |
| 943 | .for_background = work->for_background, |
Dave Chinner | 7747bd4 | 2013-07-02 22:38:35 +1000 | [diff] [blame] | 944 | .for_sync = work->for_sync, |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 945 | .range_cyclic = work->range_cyclic, |
| 946 | .range_start = 0, |
| 947 | .range_end = LLONG_MAX, |
| 948 | }; |
| 949 | unsigned long start_time = jiffies; |
| 950 | long write_chunk; |
| 951 | long wrote = 0; /* count both pages and inodes */ |
| 952 | |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 953 | while (!list_empty(&wb->b_io)) { |
Nick Piggin | 7ccf19a | 2010-10-21 11:49:30 +1100 | [diff] [blame] | 954 | struct inode *inode = wb_inode(wb->b_io.prev); |
Christoph Hellwig | edadfb1 | 2010-06-10 12:07:54 +0200 | [diff] [blame] | 955 | |
| 956 | if (inode->i_sb != sb) { |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 957 | if (work->sb) { |
Christoph Hellwig | edadfb1 | 2010-06-10 12:07:54 +0200 | [diff] [blame] | 958 | /* |
| 959 | * We only want to write back data for this |
| 960 | * superblock, move all inodes not belonging |
| 961 | * to it back onto the dirty list. |
| 962 | */ |
Christoph Hellwig | f758eea | 2011-04-21 18:19:44 -0600 | [diff] [blame] | 963 | redirty_tail(inode, wb); |
Christoph Hellwig | edadfb1 | 2010-06-10 12:07:54 +0200 | [diff] [blame] | 964 | continue; |
| 965 | } |
| 966 | |
| 967 | /* |
| 968 | * The inode belongs to a different superblock. |
| 969 | * Bounce back to the caller to unpin this and |
| 970 | * pin the next superblock. |
| 971 | */ |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 972 | break; |
Christoph Hellwig | edadfb1 | 2010-06-10 12:07:54 +0200 | [diff] [blame] | 973 | } |
| 974 | |
Christoph Hellwig | 9843b76 | 2010-10-24 19:40:46 +0200 | [diff] [blame] | 975 | /* |
Wanpeng Li | 331cbde | 2012-06-09 11:10:55 +0800 | [diff] [blame] | 976 | * Don't bother with new inodes or inodes being freed, first |
| 977 | * kind does not need periodic writeout yet, and for the latter |
Christoph Hellwig | 9843b76 | 2010-10-24 19:40:46 +0200 | [diff] [blame] | 978 | * kind writeout is handled by the freer. |
| 979 | */ |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 980 | spin_lock(&inode->i_lock); |
Christoph Hellwig | 9843b76 | 2010-10-24 19:40:46 +0200 | [diff] [blame] | 981 | if (inode->i_state & (I_NEW | I_FREEING | I_WILL_FREE)) { |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 982 | spin_unlock(&inode->i_lock); |
Wu Fengguang | fcc5c22 | 2011-07-11 23:08:50 -0700 | [diff] [blame] | 983 | redirty_tail(inode, wb); |
Nick Piggin | 7ef0d73 | 2009-03-12 14:31:38 -0700 | [diff] [blame] | 984 | continue; |
| 985 | } |
Jan Kara | cc1676d | 2012-05-03 14:47:56 +0200 | [diff] [blame] | 986 | if ((inode->i_state & I_SYNC) && wbc.sync_mode != WB_SYNC_ALL) { |
| 987 | /* |
| 988 | * If this inode is locked for writeback and we are not |
| 989 | * doing writeback-for-data-integrity, move it to |
| 990 | * b_more_io so that writeback can proceed with the |
| 991 | * other inodes on s_io. |
| 992 | * |
| 993 | * We'll have another go at writing back this inode |
| 994 | * when we completed a full scan of b_io. |
| 995 | */ |
| 996 | spin_unlock(&inode->i_lock); |
| 997 | requeue_io(inode, wb); |
| 998 | trace_writeback_sb_inodes_requeue(inode); |
| 999 | continue; |
| 1000 | } |
Jan Kara | f0d07b7 | 2012-05-03 14:47:59 +0200 | [diff] [blame] | 1001 | spin_unlock(&wb->list_lock); |
| 1002 | |
Jan Kara | 4f8ad65 | 2012-05-03 14:48:00 +0200 | [diff] [blame] | 1003 | /* |
| 1004 | * We already requeued the inode if it had I_SYNC set and we |
| 1005 | * are doing WB_SYNC_NONE writeback. So this catches only the |
| 1006 | * WB_SYNC_ALL case. |
| 1007 | */ |
Jan Kara | 169ebd9 | 2012-05-03 14:48:03 +0200 | [diff] [blame] | 1008 | if (inode->i_state & I_SYNC) { |
| 1009 | /* Wait for I_SYNC. This function drops i_lock... */ |
| 1010 | inode_sleep_on_writeback(inode); |
| 1011 | /* Inode may be gone, start again */ |
Jan Kara | ead188f | 2012-06-08 17:07:36 +0200 | [diff] [blame] | 1012 | spin_lock(&wb->list_lock); |
Jan Kara | 169ebd9 | 2012-05-03 14:48:03 +0200 | [diff] [blame] | 1013 | continue; |
| 1014 | } |
Jan Kara | 4f8ad65 | 2012-05-03 14:48:00 +0200 | [diff] [blame] | 1015 | inode->i_state |= I_SYNC; |
| 1016 | spin_unlock(&inode->i_lock); |
Jan Kara | 169ebd9 | 2012-05-03 14:48:03 +0200 | [diff] [blame] | 1017 | |
Tejun Heo | a88a341 | 2015-05-22 17:13:28 -0400 | [diff] [blame] | 1018 | write_chunk = writeback_chunk_size(wb, work); |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 1019 | wbc.nr_to_write = write_chunk; |
| 1020 | wbc.pages_skipped = 0; |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 1021 | |
Jan Kara | 169ebd9 | 2012-05-03 14:48:03 +0200 | [diff] [blame] | 1022 | /* |
| 1023 | * We use I_SYNC to pin the inode in memory. While it is set |
| 1024 | * evict_inode() will wait so the inode cannot be freed. |
| 1025 | */ |
Yan Hong | cd8ed2a | 2012-10-08 16:33:45 -0700 | [diff] [blame] | 1026 | __writeback_single_inode(inode, &wbc); |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 1027 | |
| 1028 | work->nr_pages -= write_chunk - wbc.nr_to_write; |
| 1029 | wrote += write_chunk - wbc.nr_to_write; |
Jan Kara | 4f8ad65 | 2012-05-03 14:48:00 +0200 | [diff] [blame] | 1030 | spin_lock(&wb->list_lock); |
| 1031 | spin_lock(&inode->i_lock); |
Theodore Ts'o | 0ae45f6 | 2015-02-02 00:37:00 -0500 | [diff] [blame] | 1032 | if (!(inode->i_state & I_DIRTY_ALL)) |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 1033 | wrote++; |
Jan Kara | 4f8ad65 | 2012-05-03 14:48:00 +0200 | [diff] [blame] | 1034 | requeue_inode(inode, wb, &wbc); |
| 1035 | inode_sync_complete(inode); |
Dave Chinner | 0f1b1fd | 2011-03-22 22:23:43 +1100 | [diff] [blame] | 1036 | spin_unlock(&inode->i_lock); |
Jan Kara | 169ebd9 | 2012-05-03 14:48:03 +0200 | [diff] [blame] | 1037 | cond_resched_lock(&wb->list_lock); |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 1038 | /* |
| 1039 | * bail out to wb_writeback() often enough to check |
| 1040 | * background threshold and other termination conditions. |
| 1041 | */ |
| 1042 | if (wrote) { |
| 1043 | if (time_is_before_jiffies(start_time + HZ / 10UL)) |
| 1044 | break; |
| 1045 | if (work->nr_pages <= 0) |
| 1046 | break; |
Fengguang Wu | 8bc3be2 | 2008-02-04 22:29:36 -0800 | [diff] [blame] | 1047 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1048 | } |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 1049 | return wrote; |
Edward Shishkin | f11c9c5 | 2010-03-11 14:09:47 -0800 | [diff] [blame] | 1050 | } |
Nick Piggin | 38f2197 | 2009-01-06 14:40:25 -0800 | [diff] [blame] | 1051 | |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 1052 | static long __writeback_inodes_wb(struct bdi_writeback *wb, |
| 1053 | struct wb_writeback_work *work) |
Edward Shishkin | f11c9c5 | 2010-03-11 14:09:47 -0800 | [diff] [blame] | 1054 | { |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 1055 | unsigned long start_time = jiffies; |
| 1056 | long wrote = 0; |
Edward Shishkin | f11c9c5 | 2010-03-11 14:09:47 -0800 | [diff] [blame] | 1057 | |
| 1058 | while (!list_empty(&wb->b_io)) { |
Nick Piggin | 7ccf19a | 2010-10-21 11:49:30 +1100 | [diff] [blame] | 1059 | struct inode *inode = wb_inode(wb->b_io.prev); |
Edward Shishkin | f11c9c5 | 2010-03-11 14:09:47 -0800 | [diff] [blame] | 1060 | struct super_block *sb = inode->i_sb; |
Edward Shishkin | f11c9c5 | 2010-03-11 14:09:47 -0800 | [diff] [blame] | 1061 | |
Konstantin Khlebnikov | eb6ef3d | 2015-02-19 20:19:35 +0300 | [diff] [blame] | 1062 | if (!trylock_super(sb)) { |
Wu Fengguang | 0e99581 | 2011-07-29 22:14:35 -0600 | [diff] [blame] | 1063 | /* |
Konstantin Khlebnikov | eb6ef3d | 2015-02-19 20:19:35 +0300 | [diff] [blame] | 1064 | * trylock_super() may fail consistently due to |
Wu Fengguang | 0e99581 | 2011-07-29 22:14:35 -0600 | [diff] [blame] | 1065 | * s_umount being grabbed by someone else. Don't use |
| 1066 | * requeue_io() to avoid busy retrying the inode/sb. |
| 1067 | */ |
| 1068 | redirty_tail(inode, wb); |
Christoph Hellwig | edadfb1 | 2010-06-10 12:07:54 +0200 | [diff] [blame] | 1069 | continue; |
Edward Shishkin | f11c9c5 | 2010-03-11 14:09:47 -0800 | [diff] [blame] | 1070 | } |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 1071 | wrote += writeback_sb_inodes(sb, wb, work); |
Konstantin Khlebnikov | eb6ef3d | 2015-02-19 20:19:35 +0300 | [diff] [blame] | 1072 | up_read(&sb->s_umount); |
Edward Shishkin | f11c9c5 | 2010-03-11 14:09:47 -0800 | [diff] [blame] | 1073 | |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 1074 | /* refer to the same tests at the end of writeback_sb_inodes */ |
| 1075 | if (wrote) { |
| 1076 | if (time_is_before_jiffies(start_time + HZ / 10UL)) |
| 1077 | break; |
| 1078 | if (work->nr_pages <= 0) |
| 1079 | break; |
| 1080 | } |
Edward Shishkin | f11c9c5 | 2010-03-11 14:09:47 -0800 | [diff] [blame] | 1081 | } |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 1082 | /* Leave any unwritten inodes on b_io */ |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 1083 | return wrote; |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 1084 | } |
| 1085 | |
Wanpeng Li | 7d9f073 | 2013-09-11 14:22:40 -0700 | [diff] [blame] | 1086 | static long writeback_inodes_wb(struct bdi_writeback *wb, long nr_pages, |
Curt Wohlgemuth | 0e175a1 | 2011-10-07 21:54:10 -0600 | [diff] [blame] | 1087 | enum wb_reason reason) |
Christoph Hellwig | edadfb1 | 2010-06-10 12:07:54 +0200 | [diff] [blame] | 1088 | { |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 1089 | struct wb_writeback_work work = { |
| 1090 | .nr_pages = nr_pages, |
| 1091 | .sync_mode = WB_SYNC_NONE, |
| 1092 | .range_cyclic = 1, |
Curt Wohlgemuth | 0e175a1 | 2011-10-07 21:54:10 -0600 | [diff] [blame] | 1093 | .reason = reason, |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 1094 | }; |
Christoph Hellwig | edadfb1 | 2010-06-10 12:07:54 +0200 | [diff] [blame] | 1095 | |
Christoph Hellwig | f758eea | 2011-04-21 18:19:44 -0600 | [diff] [blame] | 1096 | spin_lock(&wb->list_lock); |
Wu Fengguang | 424b351 | 2010-07-21 20:11:53 -0600 | [diff] [blame] | 1097 | if (list_empty(&wb->b_io)) |
Curt Wohlgemuth | ad4e38d | 2011-10-07 21:51:56 -0600 | [diff] [blame] | 1098 | queue_io(wb, &work); |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 1099 | __writeback_inodes_wb(wb, &work); |
Christoph Hellwig | f758eea | 2011-04-21 18:19:44 -0600 | [diff] [blame] | 1100 | spin_unlock(&wb->list_lock); |
Christoph Hellwig | edadfb1 | 2010-06-10 12:07:54 +0200 | [diff] [blame] | 1101 | |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 1102 | return nr_pages - work.nr_pages; |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 1103 | } |
| 1104 | |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1105 | /* |
| 1106 | * Explicit flushing or periodic writeback of "old" data. |
| 1107 | * |
| 1108 | * Define "old": the first time one of an inode's pages is dirtied, we mark the |
| 1109 | * dirtying-time in the inode's address_space. So this periodic writeback code |
| 1110 | * just walks the superblock inode list, writing back any inodes which are |
| 1111 | * older than a specific point in time. |
| 1112 | * |
| 1113 | * Try to run once per dirty_writeback_interval. But if a writeback event |
| 1114 | * takes longer than a dirty_writeback_interval interval, then leave a |
| 1115 | * one-second gap. |
| 1116 | * |
| 1117 | * older_than_this takes precedence over nr_to_write. So we'll only write back |
| 1118 | * all dirty pages if they are all attached to "old" mappings. |
| 1119 | */ |
Jens Axboe | c4a77a6 | 2009-09-16 15:18:25 +0200 | [diff] [blame] | 1120 | static long wb_writeback(struct bdi_writeback *wb, |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 1121 | struct wb_writeback_work *work) |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1122 | { |
Wu Fengguang | e98be2d | 2010-08-29 11:22:30 -0600 | [diff] [blame] | 1123 | unsigned long wb_start = jiffies; |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 1124 | long nr_pages = work->nr_pages; |
Jan Kara | 0dc83bd | 2014-02-21 11:19:04 +0100 | [diff] [blame] | 1125 | unsigned long oldest_jif; |
Jan Kara | a5989bd | 2009-09-16 19:22:48 +0200 | [diff] [blame] | 1126 | struct inode *inode; |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 1127 | long progress; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1128 | |
Jan Kara | 0dc83bd | 2014-02-21 11:19:04 +0100 | [diff] [blame] | 1129 | oldest_jif = jiffies; |
| 1130 | work->older_than_this = &oldest_jif; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1131 | |
Wu Fengguang | e8dfc30 | 2011-04-21 12:06:32 -0600 | [diff] [blame] | 1132 | spin_lock(&wb->list_lock); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1133 | for (;;) { |
| 1134 | /* |
Wu Fengguang | d3ddec7 | 2009-09-23 20:33:40 +0800 | [diff] [blame] | 1135 | * Stop writeback when nr_pages has been consumed |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1136 | */ |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 1137 | if (work->nr_pages <= 0) |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1138 | break; |
| 1139 | |
| 1140 | /* |
Jan Kara | aa373cf | 2011-01-13 15:45:47 -0800 | [diff] [blame] | 1141 | * Background writeout and kupdate-style writeback may |
| 1142 | * run forever. Stop them if there is other work to do |
| 1143 | * so that e.g. sync can proceed. They'll be restarted |
| 1144 | * after the other works are all done. |
| 1145 | */ |
| 1146 | if ((work->for_background || work->for_kupdate) && |
Tejun Heo | f0054bb | 2015-05-22 17:13:30 -0400 | [diff] [blame] | 1147 | !list_empty(&wb->work_list)) |
Jan Kara | aa373cf | 2011-01-13 15:45:47 -0800 | [diff] [blame] | 1148 | break; |
| 1149 | |
| 1150 | /* |
Wu Fengguang | d3ddec7 | 2009-09-23 20:33:40 +0800 | [diff] [blame] | 1151 | * For background writeout, stop when we are below the |
| 1152 | * background dirty threshold |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1153 | */ |
Tejun Heo | aa661bb | 2015-05-22 18:23:31 -0400 | [diff] [blame] | 1154 | if (work->for_background && !wb_over_bg_thresh(wb)) |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1155 | break; |
| 1156 | |
Jan Kara | 1bc36b6 | 2011-10-19 11:44:41 +0200 | [diff] [blame] | 1157 | /* |
| 1158 | * Kupdate and background works are special and we want to |
| 1159 | * include all inodes that need writing. Livelock avoidance is |
| 1160 | * handled by these works yielding to any other work so we are |
| 1161 | * safe. |
| 1162 | */ |
Wu Fengguang | ba9aa83 | 2010-07-21 20:32:30 -0600 | [diff] [blame] | 1163 | if (work->for_kupdate) { |
Jan Kara | 0dc83bd | 2014-02-21 11:19:04 +0100 | [diff] [blame] | 1164 | oldest_jif = jiffies - |
Wu Fengguang | ba9aa83 | 2010-07-21 20:32:30 -0600 | [diff] [blame] | 1165 | msecs_to_jiffies(dirty_expire_interval * 10); |
Jan Kara | 1bc36b6 | 2011-10-19 11:44:41 +0200 | [diff] [blame] | 1166 | } else if (work->for_background) |
Jan Kara | 0dc83bd | 2014-02-21 11:19:04 +0100 | [diff] [blame] | 1167 | oldest_jif = jiffies; |
Dave Chinner | 028c2dd | 2010-07-07 13:24:07 +1000 | [diff] [blame] | 1168 | |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 1169 | trace_writeback_start(wb->bdi, work); |
Wu Fengguang | e8dfc30 | 2011-04-21 12:06:32 -0600 | [diff] [blame] | 1170 | if (list_empty(&wb->b_io)) |
Curt Wohlgemuth | ad4e38d | 2011-10-07 21:51:56 -0600 | [diff] [blame] | 1171 | queue_io(wb, work); |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 1172 | if (work->sb) |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 1173 | progress = writeback_sb_inodes(work->sb, wb, work); |
Christoph Hellwig | edadfb1 | 2010-06-10 12:07:54 +0200 | [diff] [blame] | 1174 | else |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 1175 | progress = __writeback_inodes_wb(wb, work); |
| 1176 | trace_writeback_written(wb->bdi, work); |
Dave Chinner | 028c2dd | 2010-07-07 13:24:07 +1000 | [diff] [blame] | 1177 | |
Wu Fengguang | e98be2d | 2010-08-29 11:22:30 -0600 | [diff] [blame] | 1178 | wb_update_bandwidth(wb, wb_start); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1179 | |
| 1180 | /* |
Jens Axboe | 71fd05a | 2009-09-23 19:32:26 +0200 | [diff] [blame] | 1181 | * Did we write something? Try for more |
Wu Fengguang | e6fb6da | 2010-07-22 10:23:44 -0600 | [diff] [blame] | 1182 | * |
| 1183 | * Dirty inodes are moved to b_io for writeback in batches. |
| 1184 | * The completion of the current batch does not necessarily |
| 1185 | * mean the overall work is done. So we keep looping as long |
| 1186 | * as made some progress on cleaning pages or inodes. |
Jens Axboe | 71fd05a | 2009-09-23 19:32:26 +0200 | [diff] [blame] | 1187 | */ |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 1188 | if (progress) |
Jens Axboe | 71fd05a | 2009-09-23 19:32:26 +0200 | [diff] [blame] | 1189 | continue; |
| 1190 | /* |
Wu Fengguang | e6fb6da | 2010-07-22 10:23:44 -0600 | [diff] [blame] | 1191 | * No more inodes for IO, bail |
Jens Axboe | 71fd05a | 2009-09-23 19:32:26 +0200 | [diff] [blame] | 1192 | */ |
Wu Fengguang | b7a2441 | 2010-07-21 22:19:51 -0600 | [diff] [blame] | 1193 | if (list_empty(&wb->b_more_io)) |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1194 | break; |
| 1195 | /* |
Jens Axboe | 8010c3b | 2009-09-15 20:04:57 +0200 | [diff] [blame] | 1196 | * Nothing written. Wait for some inode to |
| 1197 | * become available for writeback. Otherwise |
| 1198 | * we'll just busyloop. |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1199 | */ |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1200 | if (!list_empty(&wb->b_more_io)) { |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 1201 | trace_writeback_wait(wb->bdi, work); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1202 | inode = wb_inode(wb->b_more_io.prev); |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 1203 | spin_lock(&inode->i_lock); |
Jan Kara | f0d07b7 | 2012-05-03 14:47:59 +0200 | [diff] [blame] | 1204 | spin_unlock(&wb->list_lock); |
Jan Kara | 169ebd9 | 2012-05-03 14:48:03 +0200 | [diff] [blame] | 1205 | /* This function drops i_lock... */ |
| 1206 | inode_sleep_on_writeback(inode); |
Jan Kara | f0d07b7 | 2012-05-03 14:47:59 +0200 | [diff] [blame] | 1207 | spin_lock(&wb->list_lock); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1208 | } |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1209 | } |
Wu Fengguang | e8dfc30 | 2011-04-21 12:06:32 -0600 | [diff] [blame] | 1210 | spin_unlock(&wb->list_lock); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1211 | |
Wu Fengguang | d46db3d | 2011-05-04 19:54:37 -0600 | [diff] [blame] | 1212 | return nr_pages - work->nr_pages; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1213 | } |
| 1214 | |
| 1215 | /* |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 1216 | * 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] | 1217 | */ |
Tejun Heo | f0054bb | 2015-05-22 17:13:30 -0400 | [diff] [blame] | 1218 | static struct wb_writeback_work *get_next_work_item(struct bdi_writeback *wb) |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1219 | { |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 1220 | struct wb_writeback_work *work = NULL; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1221 | |
Tejun Heo | f0054bb | 2015-05-22 17:13:30 -0400 | [diff] [blame] | 1222 | spin_lock_bh(&wb->work_lock); |
| 1223 | if (!list_empty(&wb->work_list)) { |
| 1224 | work = list_entry(wb->work_list.next, |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 1225 | struct wb_writeback_work, list); |
| 1226 | list_del_init(&work->list); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1227 | } |
Tejun Heo | f0054bb | 2015-05-22 17:13:30 -0400 | [diff] [blame] | 1228 | spin_unlock_bh(&wb->work_lock); |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 1229 | return work; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1230 | } |
| 1231 | |
Linus Torvalds | cdf01dd | 2010-10-30 08:55:52 -0700 | [diff] [blame] | 1232 | /* |
| 1233 | * Add in the number of potentially dirty inodes, because each inode |
| 1234 | * write can dirty pagecache in the underlying blockdev. |
| 1235 | */ |
| 1236 | static unsigned long get_nr_dirty_pages(void) |
| 1237 | { |
| 1238 | return global_page_state(NR_FILE_DIRTY) + |
| 1239 | global_page_state(NR_UNSTABLE_NFS) + |
| 1240 | get_nr_dirty_inodes(); |
| 1241 | } |
| 1242 | |
Jan Kara | 6585027 | 2011-01-13 15:45:44 -0800 | [diff] [blame] | 1243 | static long wb_check_background_flush(struct bdi_writeback *wb) |
| 1244 | { |
Tejun Heo | aa661bb | 2015-05-22 18:23:31 -0400 | [diff] [blame] | 1245 | if (wb_over_bg_thresh(wb)) { |
Jan Kara | 6585027 | 2011-01-13 15:45:44 -0800 | [diff] [blame] | 1246 | |
| 1247 | struct wb_writeback_work work = { |
| 1248 | .nr_pages = LONG_MAX, |
| 1249 | .sync_mode = WB_SYNC_NONE, |
| 1250 | .for_background = 1, |
| 1251 | .range_cyclic = 1, |
Curt Wohlgemuth | 0e175a1 | 2011-10-07 21:54:10 -0600 | [diff] [blame] | 1252 | .reason = WB_REASON_BACKGROUND, |
Jan Kara | 6585027 | 2011-01-13 15:45:44 -0800 | [diff] [blame] | 1253 | }; |
| 1254 | |
| 1255 | return wb_writeback(wb, &work); |
| 1256 | } |
| 1257 | |
| 1258 | return 0; |
| 1259 | } |
| 1260 | |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1261 | static long wb_check_old_data_flush(struct bdi_writeback *wb) |
| 1262 | { |
| 1263 | unsigned long expired; |
| 1264 | long nr_pages; |
| 1265 | |
Jens Axboe | 69b62d0 | 2010-05-17 12:51:03 +0200 | [diff] [blame] | 1266 | /* |
| 1267 | * When set to zero, disable periodic writeback |
| 1268 | */ |
| 1269 | if (!dirty_writeback_interval) |
| 1270 | return 0; |
| 1271 | |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1272 | expired = wb->last_old_flush + |
| 1273 | msecs_to_jiffies(dirty_writeback_interval * 10); |
| 1274 | if (time_before(jiffies, expired)) |
| 1275 | return 0; |
| 1276 | |
| 1277 | wb->last_old_flush = jiffies; |
Linus Torvalds | cdf01dd | 2010-10-30 08:55:52 -0700 | [diff] [blame] | 1278 | nr_pages = get_nr_dirty_pages(); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1279 | |
Jens Axboe | c4a77a6 | 2009-09-16 15:18:25 +0200 | [diff] [blame] | 1280 | if (nr_pages) { |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 1281 | struct wb_writeback_work work = { |
Jens Axboe | c4a77a6 | 2009-09-16 15:18:25 +0200 | [diff] [blame] | 1282 | .nr_pages = nr_pages, |
| 1283 | .sync_mode = WB_SYNC_NONE, |
| 1284 | .for_kupdate = 1, |
| 1285 | .range_cyclic = 1, |
Curt Wohlgemuth | 0e175a1 | 2011-10-07 21:54:10 -0600 | [diff] [blame] | 1286 | .reason = WB_REASON_PERIODIC, |
Jens Axboe | c4a77a6 | 2009-09-16 15:18:25 +0200 | [diff] [blame] | 1287 | }; |
| 1288 | |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 1289 | return wb_writeback(wb, &work); |
Jens Axboe | c4a77a6 | 2009-09-16 15:18:25 +0200 | [diff] [blame] | 1290 | } |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1291 | |
| 1292 | return 0; |
| 1293 | } |
| 1294 | |
| 1295 | /* |
| 1296 | * Retrieve work items and do the writeback they describe |
| 1297 | */ |
Wanpeng Li | 25d130b | 2013-07-08 16:00:14 -0700 | [diff] [blame] | 1298 | static long wb_do_writeback(struct bdi_writeback *wb) |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1299 | { |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 1300 | struct wb_writeback_work *work; |
Jens Axboe | c4a77a6 | 2009-09-16 15:18:25 +0200 | [diff] [blame] | 1301 | long wrote = 0; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1302 | |
Tejun Heo | 4452226 | 2015-05-22 17:13:26 -0400 | [diff] [blame] | 1303 | set_bit(WB_writeback_running, &wb->state); |
Tejun Heo | f0054bb | 2015-05-22 17:13:30 -0400 | [diff] [blame] | 1304 | while ((work = get_next_work_item(wb)) != NULL) { |
Tejun Heo | cc395d7 | 2015-05-22 17:13:58 -0400 | [diff] [blame] | 1305 | struct wb_completion *done = work->done; |
Tejun Heo | 98754bf | 2015-05-22 17:13:59 -0400 | [diff] [blame] | 1306 | bool need_wake_up = false; |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 1307 | |
Tejun Heo | f0054bb | 2015-05-22 17:13:30 -0400 | [diff] [blame] | 1308 | trace_writeback_exec(wb->bdi, work); |
Dave Chinner | 455b286 | 2010-07-07 13:24:06 +1000 | [diff] [blame] | 1309 | |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 1310 | wrote += wb_writeback(wb, work); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1311 | |
Tejun Heo | 98754bf | 2015-05-22 17:13:59 -0400 | [diff] [blame] | 1312 | if (work->single_wait) { |
| 1313 | WARN_ON_ONCE(work->auto_free); |
| 1314 | /* paired w/ rmb in wb_wait_for_single_work() */ |
| 1315 | smp_wmb(); |
| 1316 | work->single_done = 1; |
| 1317 | need_wake_up = true; |
| 1318 | } else if (work->auto_free) { |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 1319 | kfree(work); |
Tejun Heo | 98754bf | 2015-05-22 17:13:59 -0400 | [diff] [blame] | 1320 | } |
| 1321 | |
Tejun Heo | cc395d7 | 2015-05-22 17:13:58 -0400 | [diff] [blame] | 1322 | if (done && atomic_dec_and_test(&done->cnt)) |
Tejun Heo | 98754bf | 2015-05-22 17:13:59 -0400 | [diff] [blame] | 1323 | need_wake_up = true; |
| 1324 | |
| 1325 | if (need_wake_up) |
Tejun Heo | cc395d7 | 2015-05-22 17:13:58 -0400 | [diff] [blame] | 1326 | wake_up_all(&wb->bdi->wb_waitq); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1327 | } |
| 1328 | |
| 1329 | /* |
| 1330 | * Check for periodic writeback, kupdated() style |
| 1331 | */ |
| 1332 | wrote += wb_check_old_data_flush(wb); |
Jan Kara | 6585027 | 2011-01-13 15:45:44 -0800 | [diff] [blame] | 1333 | wrote += wb_check_background_flush(wb); |
Tejun Heo | 4452226 | 2015-05-22 17:13:26 -0400 | [diff] [blame] | 1334 | clear_bit(WB_writeback_running, &wb->state); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1335 | |
| 1336 | return wrote; |
| 1337 | } |
| 1338 | |
| 1339 | /* |
| 1340 | * Handle writeback of dirty data for the device backed by this bdi. Also |
Tejun Heo | 839a8e8 | 2013-04-01 19:08:06 -0700 | [diff] [blame] | 1341 | * reschedules periodically and does kupdated style flushing. |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1342 | */ |
Tejun Heo | f0054bb | 2015-05-22 17:13:30 -0400 | [diff] [blame] | 1343 | void wb_workfn(struct work_struct *work) |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1344 | { |
Tejun Heo | 839a8e8 | 2013-04-01 19:08:06 -0700 | [diff] [blame] | 1345 | struct bdi_writeback *wb = container_of(to_delayed_work(work), |
| 1346 | struct bdi_writeback, dwork); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1347 | long pages_written; |
| 1348 | |
Tejun Heo | f0054bb | 2015-05-22 17:13:30 -0400 | [diff] [blame] | 1349 | set_worker_desc("flush-%s", dev_name(wb->bdi->dev)); |
Peter Zijlstra | 766f916 | 2010-10-26 14:22:45 -0700 | [diff] [blame] | 1350 | current->flags |= PF_SWAPWRITE; |
Christoph Hellwig | 0824390 | 2010-06-19 23:08:22 +0200 | [diff] [blame] | 1351 | |
Tejun Heo | 839a8e8 | 2013-04-01 19:08:06 -0700 | [diff] [blame] | 1352 | if (likely(!current_is_workqueue_rescuer() || |
Tejun Heo | 4452226 | 2015-05-22 17:13:26 -0400 | [diff] [blame] | 1353 | !test_bit(WB_registered, &wb->state))) { |
Artem Bityutskiy | 6467716 | 2010-07-25 14:29:22 +0300 | [diff] [blame] | 1354 | /* |
Tejun Heo | f0054bb | 2015-05-22 17:13:30 -0400 | [diff] [blame] | 1355 | * The normal path. Keep writing back @wb until its |
Tejun Heo | 839a8e8 | 2013-04-01 19:08:06 -0700 | [diff] [blame] | 1356 | * work_list is empty. Note that this path is also taken |
Tejun Heo | f0054bb | 2015-05-22 17:13:30 -0400 | [diff] [blame] | 1357 | * if @wb is shutting down even when we're running off the |
Tejun Heo | 839a8e8 | 2013-04-01 19:08:06 -0700 | [diff] [blame] | 1358 | * rescuer as work_list needs to be drained. |
Artem Bityutskiy | 6467716 | 2010-07-25 14:29:22 +0300 | [diff] [blame] | 1359 | */ |
Tejun Heo | 839a8e8 | 2013-04-01 19:08:06 -0700 | [diff] [blame] | 1360 | do { |
Wanpeng Li | 25d130b | 2013-07-08 16:00:14 -0700 | [diff] [blame] | 1361 | pages_written = wb_do_writeback(wb); |
Tejun Heo | 839a8e8 | 2013-04-01 19:08:06 -0700 | [diff] [blame] | 1362 | trace_writeback_pages_written(pages_written); |
Tejun Heo | f0054bb | 2015-05-22 17:13:30 -0400 | [diff] [blame] | 1363 | } while (!list_empty(&wb->work_list)); |
Tejun Heo | 839a8e8 | 2013-04-01 19:08:06 -0700 | [diff] [blame] | 1364 | } else { |
| 1365 | /* |
| 1366 | * bdi_wq can't get enough workers and we're running off |
| 1367 | * the emergency worker. Don't hog it. Hopefully, 1024 is |
| 1368 | * enough for efficient IO. |
| 1369 | */ |
Tejun Heo | f0054bb | 2015-05-22 17:13:30 -0400 | [diff] [blame] | 1370 | pages_written = writeback_inodes_wb(wb, 1024, |
Tejun Heo | 839a8e8 | 2013-04-01 19:08:06 -0700 | [diff] [blame] | 1371 | WB_REASON_FORKER_THREAD); |
Dave Chinner | 455b286 | 2010-07-07 13:24:06 +1000 | [diff] [blame] | 1372 | trace_writeback_pages_written(pages_written); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1373 | } |
| 1374 | |
Tejun Heo | f0054bb | 2015-05-22 17:13:30 -0400 | [diff] [blame] | 1375 | if (!list_empty(&wb->work_list)) |
Derek Basehore | 6ca738d | 2014-04-03 14:46:22 -0700 | [diff] [blame] | 1376 | mod_delayed_work(bdi_wq, &wb->dwork, 0); |
| 1377 | else if (wb_has_dirty_io(wb) && dirty_writeback_interval) |
Tejun Heo | f0054bb | 2015-05-22 17:13:30 -0400 | [diff] [blame] | 1378 | wb_wakeup_delayed(wb); |
Dave Chinner | 455b286 | 2010-07-07 13:24:06 +1000 | [diff] [blame] | 1379 | |
Tejun Heo | 839a8e8 | 2013-04-01 19:08:06 -0700 | [diff] [blame] | 1380 | current->flags &= ~PF_SWAPWRITE; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1381 | } |
| 1382 | |
| 1383 | /* |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1384 | * Start writeback of `nr_pages' pages. If `nr_pages' is zero, write back |
| 1385 | * the whole world. |
| 1386 | */ |
Curt Wohlgemuth | 0e175a1 | 2011-10-07 21:54:10 -0600 | [diff] [blame] | 1387 | void wakeup_flusher_threads(long nr_pages, enum wb_reason reason) |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1388 | { |
Christoph Hellwig | b8c2f34 | 2010-06-08 18:15:07 +0200 | [diff] [blame] | 1389 | struct backing_dev_info *bdi; |
Christoph Hellwig | b8c2f34 | 2010-06-08 18:15:07 +0200 | [diff] [blame] | 1390 | |
Jan Kara | 47df3dd | 2013-09-11 14:22:22 -0700 | [diff] [blame] | 1391 | if (!nr_pages) |
| 1392 | nr_pages = get_nr_dirty_pages(); |
Christoph Hellwig | b8c2f34 | 2010-06-08 18:15:07 +0200 | [diff] [blame] | 1393 | |
| 1394 | rcu_read_lock(); |
Tejun Heo | f2b6512 | 2015-05-22 17:13:55 -0400 | [diff] [blame] | 1395 | list_for_each_entry_rcu(bdi, &bdi_list, bdi_list) { |
| 1396 | struct bdi_writeback *wb; |
| 1397 | struct wb_iter iter; |
| 1398 | |
| 1399 | if (!bdi_has_dirty_io(bdi)) |
| 1400 | continue; |
| 1401 | |
| 1402 | bdi_for_each_wb(wb, bdi, &iter, 0) |
| 1403 | wb_start_writeback(wb, wb_split_bdi_pages(wb, nr_pages), |
| 1404 | false, reason); |
| 1405 | } |
Christoph Hellwig | b8c2f34 | 2010-06-08 18:15:07 +0200 | [diff] [blame] | 1406 | rcu_read_unlock(); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1407 | } |
| 1408 | |
Theodore Ts'o | a2f4870 | 2015-03-17 12:23:19 -0400 | [diff] [blame] | 1409 | /* |
| 1410 | * Wake up bdi's periodically to make sure dirtytime inodes gets |
| 1411 | * written back periodically. We deliberately do *not* check the |
| 1412 | * b_dirtytime list in wb_has_dirty_io(), since this would cause the |
| 1413 | * kernel to be constantly waking up once there are any dirtytime |
| 1414 | * inodes on the system. So instead we define a separate delayed work |
| 1415 | * function which gets called much more rarely. (By default, only |
| 1416 | * once every 12 hours.) |
| 1417 | * |
| 1418 | * If there is any other write activity going on in the file system, |
| 1419 | * this function won't be necessary. But if the only thing that has |
| 1420 | * happened on the file system is a dirtytime inode caused by an atime |
| 1421 | * update, we need this infrastructure below to make sure that inode |
| 1422 | * eventually gets pushed out to disk. |
| 1423 | */ |
| 1424 | static void wakeup_dirtytime_writeback(struct work_struct *w); |
| 1425 | static DECLARE_DELAYED_WORK(dirtytime_work, wakeup_dirtytime_writeback); |
| 1426 | |
| 1427 | static void wakeup_dirtytime_writeback(struct work_struct *w) |
| 1428 | { |
| 1429 | struct backing_dev_info *bdi; |
| 1430 | |
| 1431 | rcu_read_lock(); |
| 1432 | list_for_each_entry_rcu(bdi, &bdi_list, bdi_list) { |
Tejun Heo | 001fe6f | 2015-05-22 17:13:56 -0400 | [diff] [blame] | 1433 | struct bdi_writeback *wb; |
| 1434 | struct wb_iter iter; |
| 1435 | |
| 1436 | bdi_for_each_wb(wb, bdi, &iter, 0) |
| 1437 | if (!list_empty(&bdi->wb.b_dirty_time)) |
| 1438 | wb_wakeup(&bdi->wb); |
Theodore Ts'o | a2f4870 | 2015-03-17 12:23:19 -0400 | [diff] [blame] | 1439 | } |
| 1440 | rcu_read_unlock(); |
| 1441 | schedule_delayed_work(&dirtytime_work, dirtytime_expire_interval * HZ); |
| 1442 | } |
| 1443 | |
| 1444 | static int __init start_dirtytime_writeback(void) |
| 1445 | { |
| 1446 | schedule_delayed_work(&dirtytime_work, dirtytime_expire_interval * HZ); |
| 1447 | return 0; |
| 1448 | } |
| 1449 | __initcall(start_dirtytime_writeback); |
| 1450 | |
Theodore Ts'o | 1efff91 | 2015-03-17 12:23:32 -0400 | [diff] [blame] | 1451 | int dirtytime_interval_handler(struct ctl_table *table, int write, |
| 1452 | void __user *buffer, size_t *lenp, loff_t *ppos) |
| 1453 | { |
| 1454 | int ret; |
| 1455 | |
| 1456 | ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); |
| 1457 | if (ret == 0 && write) |
| 1458 | mod_delayed_work(system_wq, &dirtytime_work, 0); |
| 1459 | return ret; |
| 1460 | } |
| 1461 | |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1462 | static noinline void block_dump___mark_inode_dirty(struct inode *inode) |
| 1463 | { |
| 1464 | if (inode->i_ino || strcmp(inode->i_sb->s_id, "bdev")) { |
| 1465 | struct dentry *dentry; |
| 1466 | const char *name = "?"; |
| 1467 | |
| 1468 | dentry = d_find_alias(inode); |
| 1469 | if (dentry) { |
| 1470 | spin_lock(&dentry->d_lock); |
| 1471 | name = (const char *) dentry->d_name.name; |
| 1472 | } |
| 1473 | printk(KERN_DEBUG |
| 1474 | "%s(%d): dirtied inode %lu (%s) on %s\n", |
| 1475 | current->comm, task_pid_nr(current), inode->i_ino, |
| 1476 | name, inode->i_sb->s_id); |
| 1477 | if (dentry) { |
| 1478 | spin_unlock(&dentry->d_lock); |
| 1479 | dput(dentry); |
| 1480 | } |
| 1481 | } |
| 1482 | } |
| 1483 | |
| 1484 | /** |
| 1485 | * __mark_inode_dirty - internal function |
| 1486 | * @inode: inode to mark |
| 1487 | * @flags: what kind of dirty (i.e. I_DIRTY_SYNC) |
| 1488 | * Mark an inode as dirty. Callers should use mark_inode_dirty or |
| 1489 | * mark_inode_dirty_sync. |
| 1490 | * |
| 1491 | * Put the inode on the super block's dirty list. |
| 1492 | * |
| 1493 | * CAREFUL! We mark it dirty unconditionally, but move it onto the |
| 1494 | * dirty list only if it is hashed or if it refers to a blockdev. |
| 1495 | * If it was not hashed, it will never be added to the dirty list |
| 1496 | * even if it is later hashed, as it will have been marked dirty already. |
| 1497 | * |
| 1498 | * In short, make sure you hash any inodes _before_ you start marking |
| 1499 | * them dirty. |
| 1500 | * |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1501 | * Note that for blockdevs, inode->dirtied_when represents the dirtying time of |
| 1502 | * the block-special inode (/dev/hda1) itself. And the ->dirtied_when field of |
| 1503 | * the kernel-internal blockdev inode represents the dirtying time of the |
| 1504 | * blockdev's pages. This is why for I_DIRTY_PAGES we always use |
| 1505 | * page->mapping->host, so the page-dirtying time is recorded in the internal |
| 1506 | * blockdev inode. |
| 1507 | */ |
Theodore Ts'o | 0ae45f6 | 2015-02-02 00:37:00 -0500 | [diff] [blame] | 1508 | #define I_DIRTY_INODE (I_DIRTY_SYNC | I_DIRTY_DATASYNC) |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1509 | void __mark_inode_dirty(struct inode *inode, int flags) |
| 1510 | { |
| 1511 | struct super_block *sb = inode->i_sb; |
Theodore Ts'o | 0ae45f6 | 2015-02-02 00:37:00 -0500 | [diff] [blame] | 1512 | int dirtytime; |
| 1513 | |
| 1514 | trace_writeback_mark_inode_dirty(inode, flags); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1515 | |
| 1516 | /* |
| 1517 | * Don't do this for I_DIRTY_PAGES - that doesn't actually |
| 1518 | * dirty the inode itself |
| 1519 | */ |
Theodore Ts'o | 0ae45f6 | 2015-02-02 00:37:00 -0500 | [diff] [blame] | 1520 | if (flags & (I_DIRTY_SYNC | I_DIRTY_DATASYNC | I_DIRTY_TIME)) { |
Tejun Heo | 9fb0a7d | 2013-01-11 13:06:37 -0800 | [diff] [blame] | 1521 | trace_writeback_dirty_inode_start(inode, flags); |
| 1522 | |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1523 | if (sb->s_op->dirty_inode) |
Christoph Hellwig | aa38572 | 2011-05-27 06:53:02 -0400 | [diff] [blame] | 1524 | sb->s_op->dirty_inode(inode, flags); |
Tejun Heo | 9fb0a7d | 2013-01-11 13:06:37 -0800 | [diff] [blame] | 1525 | |
| 1526 | trace_writeback_dirty_inode(inode, flags); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1527 | } |
Theodore Ts'o | 0ae45f6 | 2015-02-02 00:37:00 -0500 | [diff] [blame] | 1528 | if (flags & I_DIRTY_INODE) |
| 1529 | flags &= ~I_DIRTY_TIME; |
| 1530 | dirtytime = flags & I_DIRTY_TIME; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1531 | |
| 1532 | /* |
Tejun Heo | 9c6ac78 | 2014-10-24 15:38:21 -0400 | [diff] [blame] | 1533 | * Paired with smp_mb() in __writeback_single_inode() for the |
| 1534 | * following lockless i_state test. See there for details. |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1535 | */ |
| 1536 | smp_mb(); |
| 1537 | |
Theodore Ts'o | 0ae45f6 | 2015-02-02 00:37:00 -0500 | [diff] [blame] | 1538 | if (((inode->i_state & flags) == flags) || |
| 1539 | (dirtytime && (inode->i_state & I_DIRTY_INODE))) |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1540 | return; |
| 1541 | |
| 1542 | if (unlikely(block_dump)) |
| 1543 | block_dump___mark_inode_dirty(inode); |
| 1544 | |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 1545 | spin_lock(&inode->i_lock); |
Theodore Ts'o | 0ae45f6 | 2015-02-02 00:37:00 -0500 | [diff] [blame] | 1546 | if (dirtytime && (inode->i_state & I_DIRTY_INODE)) |
| 1547 | goto out_unlock_inode; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1548 | if ((inode->i_state & flags) != flags) { |
| 1549 | const int was_dirty = inode->i_state & I_DIRTY; |
| 1550 | |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 1551 | inode_attach_wb(inode, NULL); |
| 1552 | |
Theodore Ts'o | 0ae45f6 | 2015-02-02 00:37:00 -0500 | [diff] [blame] | 1553 | if (flags & I_DIRTY_INODE) |
| 1554 | inode->i_state &= ~I_DIRTY_TIME; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1555 | inode->i_state |= flags; |
| 1556 | |
| 1557 | /* |
| 1558 | * If the inode is being synced, just update its dirty state. |
| 1559 | * The unlocker will place the inode on the appropriate |
| 1560 | * superblock list, based upon its state. |
| 1561 | */ |
| 1562 | if (inode->i_state & I_SYNC) |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 1563 | goto out_unlock_inode; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1564 | |
| 1565 | /* |
| 1566 | * Only add valid (hashed) inodes to the superblock's |
| 1567 | * dirty list. Add blockdev inodes as well. |
| 1568 | */ |
| 1569 | if (!S_ISBLK(inode->i_mode)) { |
Al Viro | 1d3382cb | 2010-10-23 15:19:20 -0400 | [diff] [blame] | 1570 | if (inode_unhashed(inode)) |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 1571 | goto out_unlock_inode; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1572 | } |
Al Viro | a4ffdde | 2010-06-02 17:38:30 -0400 | [diff] [blame] | 1573 | if (inode->i_state & I_FREEING) |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 1574 | goto out_unlock_inode; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1575 | |
| 1576 | /* |
| 1577 | * If the inode was already on b_dirty/b_io/b_more_io, don't |
| 1578 | * reposition it (that would break b_dirty time-ordering). |
| 1579 | */ |
| 1580 | if (!was_dirty) { |
Tejun Heo | 0747259 | 2015-05-22 17:14:02 -0400 | [diff] [blame] | 1581 | struct bdi_writeback *wb = inode_to_wb(inode); |
Tejun Heo | d6c10f1 | 2015-05-22 17:13:45 -0400 | [diff] [blame] | 1582 | struct list_head *dirty_list; |
Dave Chinner | a66979a | 2011-03-22 22:23:41 +1100 | [diff] [blame] | 1583 | bool wakeup_bdi = false; |
Jens Axboe | 500b067 | 2009-09-09 09:10:25 +0200 | [diff] [blame] | 1584 | |
Junxiao Bi | 146d700 | 2013-09-11 14:23:04 -0700 | [diff] [blame] | 1585 | spin_unlock(&inode->i_lock); |
Tejun Heo | 0747259 | 2015-05-22 17:14:02 -0400 | [diff] [blame] | 1586 | spin_lock(&wb->list_lock); |
Artem Bityutskiy | 253c34e | 2010-07-25 14:29:21 +0300 | [diff] [blame] | 1587 | |
Tejun Heo | 0747259 | 2015-05-22 17:14:02 -0400 | [diff] [blame] | 1588 | WARN(bdi_cap_writeback_dirty(wb->bdi) && |
| 1589 | !test_bit(WB_registered, &wb->state), |
| 1590 | "bdi-%s not registered\n", wb->bdi->name); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1591 | |
| 1592 | inode->dirtied_when = jiffies; |
Theodore Ts'o | a2f4870 | 2015-03-17 12:23:19 -0400 | [diff] [blame] | 1593 | if (dirtytime) |
| 1594 | inode->dirtied_time_when = jiffies; |
Tejun Heo | d6c10f1 | 2015-05-22 17:13:45 -0400 | [diff] [blame] | 1595 | |
Theodore Ts'o | a2f4870 | 2015-03-17 12:23:19 -0400 | [diff] [blame] | 1596 | if (inode->i_state & (I_DIRTY_INODE | I_DIRTY_PAGES)) |
Tejun Heo | 0747259 | 2015-05-22 17:14:02 -0400 | [diff] [blame] | 1597 | dirty_list = &wb->b_dirty; |
Theodore Ts'o | a2f4870 | 2015-03-17 12:23:19 -0400 | [diff] [blame] | 1598 | else |
Tejun Heo | 0747259 | 2015-05-22 17:14:02 -0400 | [diff] [blame] | 1599 | dirty_list = &wb->b_dirty_time; |
Tejun Heo | d6c10f1 | 2015-05-22 17:13:45 -0400 | [diff] [blame] | 1600 | |
Tejun Heo | 0747259 | 2015-05-22 17:14:02 -0400 | [diff] [blame] | 1601 | wakeup_bdi = inode_wb_list_move_locked(inode, wb, |
Tejun Heo | d6c10f1 | 2015-05-22 17:13:45 -0400 | [diff] [blame] | 1602 | dirty_list); |
| 1603 | |
Tejun Heo | 0747259 | 2015-05-22 17:14:02 -0400 | [diff] [blame] | 1604 | spin_unlock(&wb->list_lock); |
Theodore Ts'o | 0ae45f6 | 2015-02-02 00:37:00 -0500 | [diff] [blame] | 1605 | trace_writeback_dirty_inode_enqueue(inode); |
Dave Chinner | a66979a | 2011-03-22 22:23:41 +1100 | [diff] [blame] | 1606 | |
Tejun Heo | d6c10f1 | 2015-05-22 17:13:45 -0400 | [diff] [blame] | 1607 | /* |
| 1608 | * If this is the first dirty inode for this bdi, |
| 1609 | * we have to wake-up the corresponding bdi thread |
| 1610 | * to make sure background write-back happens |
| 1611 | * later. |
| 1612 | */ |
Tejun Heo | 0747259 | 2015-05-22 17:14:02 -0400 | [diff] [blame] | 1613 | if (bdi_cap_writeback_dirty(wb->bdi) && wakeup_bdi) |
| 1614 | wb_wakeup_delayed(wb); |
Dave Chinner | a66979a | 2011-03-22 22:23:41 +1100 | [diff] [blame] | 1615 | return; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1616 | } |
| 1617 | } |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 1618 | out_unlock_inode: |
| 1619 | spin_unlock(&inode->i_lock); |
Artem Bityutskiy | 253c34e | 2010-07-25 14:29:21 +0300 | [diff] [blame] | 1620 | |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1621 | } |
| 1622 | EXPORT_SYMBOL(__mark_inode_dirty); |
| 1623 | |
Jens Axboe | b6e5131 | 2009-09-16 15:13:54 +0200 | [diff] [blame] | 1624 | static void wait_sb_inodes(struct super_block *sb) |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 1625 | { |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1626 | struct inode *inode, *old_inode = NULL; |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 1627 | |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1628 | /* |
| 1629 | * We need to be protected against the filesystem going from |
| 1630 | * r/o to r/w or vice versa. |
| 1631 | */ |
Jens Axboe | b6e5131 | 2009-09-16 15:13:54 +0200 | [diff] [blame] | 1632 | WARN_ON(!rwsem_is_locked(&sb->s_umount)); |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 1633 | |
Dave Chinner | 55fa609 | 2011-03-22 22:23:40 +1100 | [diff] [blame] | 1634 | spin_lock(&inode_sb_list_lock); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1635 | |
| 1636 | /* |
| 1637 | * Data integrity sync. Must wait for all pages under writeback, |
| 1638 | * because there may have been pages dirtied before our sync |
| 1639 | * call, but which had writeout started before we write it out. |
| 1640 | * In which case, the inode may not be on the dirty list, but |
| 1641 | * we still have to wait for that writeout. |
| 1642 | */ |
Jens Axboe | b6e5131 | 2009-09-16 15:13:54 +0200 | [diff] [blame] | 1643 | list_for_each_entry(inode, &sb->s_inodes, i_sb_list) { |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 1644 | struct address_space *mapping = inode->i_mapping; |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1645 | |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 1646 | spin_lock(&inode->i_lock); |
| 1647 | if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) || |
| 1648 | (mapping->nrpages == 0)) { |
| 1649 | spin_unlock(&inode->i_lock); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1650 | continue; |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 1651 | } |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1652 | __iget(inode); |
Dave Chinner | 250df6e | 2011-03-22 22:23:36 +1100 | [diff] [blame] | 1653 | spin_unlock(&inode->i_lock); |
Dave Chinner | 55fa609 | 2011-03-22 22:23:40 +1100 | [diff] [blame] | 1654 | spin_unlock(&inode_sb_list_lock); |
| 1655 | |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1656 | /* |
Dave Chinner | 55fa609 | 2011-03-22 22:23:40 +1100 | [diff] [blame] | 1657 | * We hold a reference to 'inode' so it couldn't have been |
| 1658 | * removed from s_inodes list while we dropped the |
| 1659 | * inode_sb_list_lock. We cannot iput the inode now as we can |
| 1660 | * be holding the last reference and we cannot iput it under |
| 1661 | * inode_sb_list_lock. So we keep the reference and iput it |
| 1662 | * later. |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1663 | */ |
| 1664 | iput(old_inode); |
| 1665 | old_inode = inode; |
| 1666 | |
| 1667 | filemap_fdatawait(mapping); |
| 1668 | |
| 1669 | cond_resched(); |
Nick Piggin | 38f2197 | 2009-01-06 14:40:25 -0800 | [diff] [blame] | 1670 | |
Dave Chinner | 55fa609 | 2011-03-22 22:23:40 +1100 | [diff] [blame] | 1671 | spin_lock(&inode_sb_list_lock); |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 1672 | } |
Dave Chinner | 55fa609 | 2011-03-22 22:23:40 +1100 | [diff] [blame] | 1673 | spin_unlock(&inode_sb_list_lock); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 1674 | iput(old_inode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1675 | } |
| 1676 | |
Tejun Heo | f30a7d0 | 2015-05-22 17:14:00 -0400 | [diff] [blame] | 1677 | static void __writeback_inodes_sb_nr(struct super_block *sb, unsigned long nr, |
| 1678 | enum wb_reason reason, bool skip_if_busy) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1679 | { |
Tejun Heo | cc395d7 | 2015-05-22 17:13:58 -0400 | [diff] [blame] | 1680 | DEFINE_WB_COMPLETION_ONSTACK(done); |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 1681 | struct wb_writeback_work work = { |
Wu Fengguang | 6e6938b | 2010-06-06 10:38:15 -0600 | [diff] [blame] | 1682 | .sb = sb, |
| 1683 | .sync_mode = WB_SYNC_NONE, |
| 1684 | .tagged_writepages = 1, |
| 1685 | .done = &done, |
| 1686 | .nr_pages = nr, |
Curt Wohlgemuth | 0e175a1 | 2011-10-07 21:54:10 -0600 | [diff] [blame] | 1687 | .reason = reason, |
Christoph Hellwig | 3c4d716 | 2010-06-08 18:14:43 +0200 | [diff] [blame] | 1688 | }; |
Tejun Heo | e797291 | 2015-05-22 17:13:48 -0400 | [diff] [blame] | 1689 | struct backing_dev_info *bdi = sb->s_bdi; |
Jens Axboe | 0e3c9a2 | 2010-06-01 11:08:43 +0200 | [diff] [blame] | 1690 | |
Tejun Heo | e797291 | 2015-05-22 17:13:48 -0400 | [diff] [blame] | 1691 | if (!bdi_has_dirty_io(bdi) || bdi == &noop_backing_dev_info) |
Jan Kara | 6eedc70 | 2012-07-03 16:45:27 +0200 | [diff] [blame] | 1692 | return; |
Christoph Hellwig | cf37e97 | 2010-06-08 18:14:51 +0200 | [diff] [blame] | 1693 | WARN_ON(!rwsem_is_locked(&sb->s_umount)); |
Tejun Heo | f30a7d0 | 2015-05-22 17:14:00 -0400 | [diff] [blame] | 1694 | |
Tejun Heo | db12536 | 2015-05-22 17:14:01 -0400 | [diff] [blame] | 1695 | bdi_split_work_to_wbs(sb->s_bdi, &work, skip_if_busy); |
Tejun Heo | cc395d7 | 2015-05-22 17:13:58 -0400 | [diff] [blame] | 1696 | wb_wait_for_completion(bdi, &done); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1697 | } |
Tejun Heo | f30a7d0 | 2015-05-22 17:14:00 -0400 | [diff] [blame] | 1698 | |
| 1699 | /** |
| 1700 | * writeback_inodes_sb_nr - writeback dirty inodes from given super_block |
| 1701 | * @sb: the superblock |
| 1702 | * @nr: the number of pages to write |
| 1703 | * @reason: reason why some writeback work initiated |
| 1704 | * |
| 1705 | * Start writeback on some inodes on this super_block. No guarantees are made |
| 1706 | * on how many (if any) will be written, and this function does not wait |
| 1707 | * for IO completion of submitted IO. |
| 1708 | */ |
| 1709 | void writeback_inodes_sb_nr(struct super_block *sb, |
| 1710 | unsigned long nr, |
| 1711 | enum wb_reason reason) |
| 1712 | { |
| 1713 | __writeback_inodes_sb_nr(sb, nr, reason, false); |
| 1714 | } |
Chris Mason | 3259f8b | 2010-10-29 11:16:17 -0400 | [diff] [blame] | 1715 | EXPORT_SYMBOL(writeback_inodes_sb_nr); |
| 1716 | |
| 1717 | /** |
| 1718 | * writeback_inodes_sb - writeback dirty inodes from given super_block |
| 1719 | * @sb: the superblock |
Marcos Paulo de Souza | 786228a | 2011-11-23 20:56:45 +0800 | [diff] [blame] | 1720 | * @reason: reason why some writeback work was initiated |
Chris Mason | 3259f8b | 2010-10-29 11:16:17 -0400 | [diff] [blame] | 1721 | * |
| 1722 | * Start writeback on some inodes on this super_block. No guarantees are made |
| 1723 | * on how many (if any) will be written, and this function does not wait |
| 1724 | * for IO completion of submitted IO. |
| 1725 | */ |
Curt Wohlgemuth | 0e175a1 | 2011-10-07 21:54:10 -0600 | [diff] [blame] | 1726 | void writeback_inodes_sb(struct super_block *sb, enum wb_reason reason) |
Chris Mason | 3259f8b | 2010-10-29 11:16:17 -0400 | [diff] [blame] | 1727 | { |
Curt Wohlgemuth | 0e175a1 | 2011-10-07 21:54:10 -0600 | [diff] [blame] | 1728 | return writeback_inodes_sb_nr(sb, get_nr_dirty_pages(), reason); |
Chris Mason | 3259f8b | 2010-10-29 11:16:17 -0400 | [diff] [blame] | 1729 | } |
Jens Axboe | d8a8559 | 2009-09-02 12:34:32 +0200 | [diff] [blame] | 1730 | EXPORT_SYMBOL(writeback_inodes_sb); |
| 1731 | |
| 1732 | /** |
Miao Xie | 10ee27a | 2013-01-10 13:47:57 +0800 | [diff] [blame] | 1733 | * try_to_writeback_inodes_sb_nr - try to start writeback if none underway |
Chris Mason | 3259f8b | 2010-10-29 11:16:17 -0400 | [diff] [blame] | 1734 | * @sb: the superblock |
| 1735 | * @nr: the number of pages to write |
Miao Xie | 10ee27a | 2013-01-10 13:47:57 +0800 | [diff] [blame] | 1736 | * @reason: the reason of writeback |
Chris Mason | 3259f8b | 2010-10-29 11:16:17 -0400 | [diff] [blame] | 1737 | * |
Miao Xie | 10ee27a | 2013-01-10 13:47:57 +0800 | [diff] [blame] | 1738 | * Invoke writeback_inodes_sb_nr if no writeback is currently underway. |
Chris Mason | 3259f8b | 2010-10-29 11:16:17 -0400 | [diff] [blame] | 1739 | * Returns 1 if writeback was started, 0 if not. |
| 1740 | */ |
Tejun Heo | f30a7d0 | 2015-05-22 17:14:00 -0400 | [diff] [blame] | 1741 | bool try_to_writeback_inodes_sb_nr(struct super_block *sb, unsigned long nr, |
| 1742 | enum wb_reason reason) |
Chris Mason | 3259f8b | 2010-10-29 11:16:17 -0400 | [diff] [blame] | 1743 | { |
Miao Xie | 10ee27a | 2013-01-10 13:47:57 +0800 | [diff] [blame] | 1744 | if (!down_read_trylock(&sb->s_umount)) |
Tejun Heo | f30a7d0 | 2015-05-22 17:14:00 -0400 | [diff] [blame] | 1745 | return false; |
Miao Xie | 10ee27a | 2013-01-10 13:47:57 +0800 | [diff] [blame] | 1746 | |
Tejun Heo | f30a7d0 | 2015-05-22 17:14:00 -0400 | [diff] [blame] | 1747 | __writeback_inodes_sb_nr(sb, nr, reason, true); |
Miao Xie | 10ee27a | 2013-01-10 13:47:57 +0800 | [diff] [blame] | 1748 | up_read(&sb->s_umount); |
Tejun Heo | f30a7d0 | 2015-05-22 17:14:00 -0400 | [diff] [blame] | 1749 | return true; |
Chris Mason | 3259f8b | 2010-10-29 11:16:17 -0400 | [diff] [blame] | 1750 | } |
Miao Xie | 10ee27a | 2013-01-10 13:47:57 +0800 | [diff] [blame] | 1751 | EXPORT_SYMBOL(try_to_writeback_inodes_sb_nr); |
| 1752 | |
| 1753 | /** |
| 1754 | * try_to_writeback_inodes_sb - try to start writeback if none underway |
| 1755 | * @sb: the superblock |
| 1756 | * @reason: reason why some writeback work was initiated |
| 1757 | * |
| 1758 | * Implement by try_to_writeback_inodes_sb_nr() |
| 1759 | * Returns 1 if writeback was started, 0 if not. |
| 1760 | */ |
Tejun Heo | f30a7d0 | 2015-05-22 17:14:00 -0400 | [diff] [blame] | 1761 | bool try_to_writeback_inodes_sb(struct super_block *sb, enum wb_reason reason) |
Miao Xie | 10ee27a | 2013-01-10 13:47:57 +0800 | [diff] [blame] | 1762 | { |
| 1763 | return try_to_writeback_inodes_sb_nr(sb, get_nr_dirty_pages(), reason); |
| 1764 | } |
| 1765 | EXPORT_SYMBOL(try_to_writeback_inodes_sb); |
Chris Mason | 3259f8b | 2010-10-29 11:16:17 -0400 | [diff] [blame] | 1766 | |
| 1767 | /** |
Jens Axboe | d8a8559 | 2009-09-02 12:34:32 +0200 | [diff] [blame] | 1768 | * sync_inodes_sb - sync sb inode pages |
Jan Kara | 0dc83bd | 2014-02-21 11:19:04 +0100 | [diff] [blame] | 1769 | * @sb: the superblock |
Jens Axboe | d8a8559 | 2009-09-02 12:34:32 +0200 | [diff] [blame] | 1770 | * |
| 1771 | * This function writes and waits on any dirty inode belonging to this |
Jan Kara | 0dc83bd | 2014-02-21 11:19:04 +0100 | [diff] [blame] | 1772 | * super_block. |
Jens Axboe | d8a8559 | 2009-09-02 12:34:32 +0200 | [diff] [blame] | 1773 | */ |
Jan Kara | 0dc83bd | 2014-02-21 11:19:04 +0100 | [diff] [blame] | 1774 | void sync_inodes_sb(struct super_block *sb) |
Jens Axboe | d8a8559 | 2009-09-02 12:34:32 +0200 | [diff] [blame] | 1775 | { |
Tejun Heo | cc395d7 | 2015-05-22 17:13:58 -0400 | [diff] [blame] | 1776 | DEFINE_WB_COMPLETION_ONSTACK(done); |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 1777 | struct wb_writeback_work work = { |
Christoph Hellwig | 3c4d716 | 2010-06-08 18:14:43 +0200 | [diff] [blame] | 1778 | .sb = sb, |
| 1779 | .sync_mode = WB_SYNC_ALL, |
| 1780 | .nr_pages = LONG_MAX, |
| 1781 | .range_cyclic = 0, |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 1782 | .done = &done, |
Curt Wohlgemuth | 0e175a1 | 2011-10-07 21:54:10 -0600 | [diff] [blame] | 1783 | .reason = WB_REASON_SYNC, |
Dave Chinner | 7747bd4 | 2013-07-02 22:38:35 +1000 | [diff] [blame] | 1784 | .for_sync = 1, |
Christoph Hellwig | 3c4d716 | 2010-06-08 18:14:43 +0200 | [diff] [blame] | 1785 | }; |
Tejun Heo | e797291 | 2015-05-22 17:13:48 -0400 | [diff] [blame] | 1786 | struct backing_dev_info *bdi = sb->s_bdi; |
Christoph Hellwig | 3c4d716 | 2010-06-08 18:14:43 +0200 | [diff] [blame] | 1787 | |
Jan Kara | 6eedc70 | 2012-07-03 16:45:27 +0200 | [diff] [blame] | 1788 | /* Nothing to do? */ |
Tejun Heo | e797291 | 2015-05-22 17:13:48 -0400 | [diff] [blame] | 1789 | if (!bdi_has_dirty_io(bdi) || bdi == &noop_backing_dev_info) |
Jan Kara | 6eedc70 | 2012-07-03 16:45:27 +0200 | [diff] [blame] | 1790 | return; |
Christoph Hellwig | cf37e97 | 2010-06-08 18:14:51 +0200 | [diff] [blame] | 1791 | WARN_ON(!rwsem_is_locked(&sb->s_umount)); |
| 1792 | |
Tejun Heo | db12536 | 2015-05-22 17:14:01 -0400 | [diff] [blame] | 1793 | bdi_split_work_to_wbs(bdi, &work, false); |
Tejun Heo | cc395d7 | 2015-05-22 17:13:58 -0400 | [diff] [blame] | 1794 | wb_wait_for_completion(bdi, &done); |
Christoph Hellwig | 83ba7b0 | 2010-07-06 08:59:53 +0200 | [diff] [blame] | 1795 | |
Jens Axboe | b6e5131 | 2009-09-16 15:13:54 +0200 | [diff] [blame] | 1796 | wait_sb_inodes(sb); |
Jens Axboe | d8a8559 | 2009-09-02 12:34:32 +0200 | [diff] [blame] | 1797 | } |
| 1798 | EXPORT_SYMBOL(sync_inodes_sb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1799 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1800 | /** |
Andrea Arcangeli | 7f04c26 | 2005-10-30 15:03:05 -0800 | [diff] [blame] | 1801 | * write_inode_now - write an inode to disk |
| 1802 | * @inode: inode to write to disk |
| 1803 | * @sync: whether the write should be synchronous or not |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1804 | * |
Andrea Arcangeli | 7f04c26 | 2005-10-30 15:03:05 -0800 | [diff] [blame] | 1805 | * This function commits an inode to disk immediately if it is dirty. This is |
| 1806 | * primarily needed by knfsd. |
| 1807 | * |
| 1808 | * 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] | 1809 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1810 | int write_inode_now(struct inode *inode, int sync) |
| 1811 | { |
Christoph Hellwig | f758eea | 2011-04-21 18:19:44 -0600 | [diff] [blame] | 1812 | struct bdi_writeback *wb = &inode_to_bdi(inode)->wb; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1813 | struct writeback_control wbc = { |
| 1814 | .nr_to_write = LONG_MAX, |
Mike Galbraith | 18914b1 | 2008-02-08 04:20:23 -0800 | [diff] [blame] | 1815 | .sync_mode = sync ? WB_SYNC_ALL : WB_SYNC_NONE, |
OGAWA Hirofumi | 111ebb6 | 2006-06-23 02:03:26 -0700 | [diff] [blame] | 1816 | .range_start = 0, |
| 1817 | .range_end = LLONG_MAX, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1818 | }; |
| 1819 | |
| 1820 | if (!mapping_cap_writeback_dirty(inode->i_mapping)) |
Andrew Morton | 49364ce | 2005-11-07 00:59:15 -0800 | [diff] [blame] | 1821 | wbc.nr_to_write = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1822 | |
| 1823 | might_sleep(); |
Jan Kara | 4f8ad65 | 2012-05-03 14:48:00 +0200 | [diff] [blame] | 1824 | return writeback_single_inode(inode, wb, &wbc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1825 | } |
| 1826 | EXPORT_SYMBOL(write_inode_now); |
| 1827 | |
| 1828 | /** |
| 1829 | * sync_inode - write an inode and its pages to disk. |
| 1830 | * @inode: the inode to sync |
| 1831 | * @wbc: controls the writeback mode |
| 1832 | * |
| 1833 | * sync_inode() will write an inode and its pages to disk. It will also |
| 1834 | * correctly update the inode on its superblock's dirty inode lists and will |
| 1835 | * update inode->i_state. |
| 1836 | * |
| 1837 | * The caller must have a ref on the inode. |
| 1838 | */ |
| 1839 | int sync_inode(struct inode *inode, struct writeback_control *wbc) |
| 1840 | { |
Jan Kara | 4f8ad65 | 2012-05-03 14:48:00 +0200 | [diff] [blame] | 1841 | return writeback_single_inode(inode, &inode_to_bdi(inode)->wb, wbc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1842 | } |
| 1843 | EXPORT_SYMBOL(sync_inode); |
Christoph Hellwig | c3765016 | 2010-10-06 10:48:20 +0200 | [diff] [blame] | 1844 | |
| 1845 | /** |
Andrew Morton | c691b9d | 2011-01-13 15:45:48 -0800 | [diff] [blame] | 1846 | * sync_inode_metadata - write an inode to disk |
Christoph Hellwig | c3765016 | 2010-10-06 10:48:20 +0200 | [diff] [blame] | 1847 | * @inode: the inode to sync |
| 1848 | * @wait: wait for I/O to complete. |
| 1849 | * |
Andrew Morton | c691b9d | 2011-01-13 15:45:48 -0800 | [diff] [blame] | 1850 | * Write an inode to disk and adjust its dirty state after completion. |
Christoph Hellwig | c3765016 | 2010-10-06 10:48:20 +0200 | [diff] [blame] | 1851 | * |
| 1852 | * Note: only writes the actual inode, no associated data or other metadata. |
| 1853 | */ |
| 1854 | int sync_inode_metadata(struct inode *inode, int wait) |
| 1855 | { |
| 1856 | struct writeback_control wbc = { |
| 1857 | .sync_mode = wait ? WB_SYNC_ALL : WB_SYNC_NONE, |
| 1858 | .nr_to_write = 0, /* metadata-only */ |
| 1859 | }; |
| 1860 | |
| 1861 | return sync_inode(inode, &wbc); |
| 1862 | } |
| 1863 | EXPORT_SYMBOL(sync_inode_metadata); |