Andrew Morton | 3fcfab1 | 2006-10-19 23:28:16 -0700 | [diff] [blame] | 1 | |
| 2 | #include <linux/wait.h> |
| 3 | #include <linux/backing-dev.h> |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 4 | #include <linux/kthread.h> |
| 5 | #include <linux/freezer.h> |
Andrew Morton | 3fcfab1 | 2006-10-19 23:28:16 -0700 | [diff] [blame] | 6 | #include <linux/fs.h> |
Jens Axboe | 2616015 | 2009-03-17 09:35:06 +0100 | [diff] [blame] | 7 | #include <linux/pagemap.h> |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 8 | #include <linux/mm.h> |
Andrew Morton | 3fcfab1 | 2006-10-19 23:28:16 -0700 | [diff] [blame] | 9 | #include <linux/sched.h> |
| 10 | #include <linux/module.h> |
Peter Zijlstra | cf0ca9f | 2008-04-30 00:54:32 -0700 | [diff] [blame] | 11 | #include <linux/writeback.h> |
| 12 | #include <linux/device.h> |
Dave Chinner | 455b286 | 2010-07-07 13:24:06 +1000 | [diff] [blame] | 13 | #include <trace/events/writeback.h> |
Peter Zijlstra | cf0ca9f | 2008-04-30 00:54:32 -0700 | [diff] [blame] | 14 | |
Jörn Engel | 5129a46 | 2010-04-25 08:54:42 +0200 | [diff] [blame] | 15 | struct backing_dev_info noop_backing_dev_info = { |
| 16 | .name = "noop", |
Jan Kara | 976e48f | 2010-09-21 11:48:55 +0200 | [diff] [blame] | 17 | .capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK, |
Jörn Engel | 5129a46 | 2010-04-25 08:54:42 +0200 | [diff] [blame] | 18 | }; |
Tejun Heo | a212b10 | 2015-05-22 17:13:33 -0400 | [diff] [blame] | 19 | EXPORT_SYMBOL_GPL(noop_backing_dev_info); |
Jörn Engel | 5129a46 | 2010-04-25 08:54:42 +0200 | [diff] [blame] | 20 | |
Peter Zijlstra | cf0ca9f | 2008-04-30 00:54:32 -0700 | [diff] [blame] | 21 | static struct class *bdi_class; |
Jens Axboe | cfc4ba5 | 2009-09-14 13:12:40 +0200 | [diff] [blame] | 22 | |
| 23 | /* |
Tejun Heo | 181387d | 2013-04-01 19:08:06 -0700 | [diff] [blame] | 24 | * bdi_lock protects updates to bdi_list. bdi_list has RCU reader side |
Jens Axboe | cfc4ba5 | 2009-09-14 13:12:40 +0200 | [diff] [blame] | 25 | * locking. |
| 26 | */ |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 27 | DEFINE_SPINLOCK(bdi_lock); |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 28 | LIST_HEAD(bdi_list); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 29 | |
Tejun Heo | 839a8e8 | 2013-04-01 19:08:06 -0700 | [diff] [blame] | 30 | /* bdi_wq serves all asynchronous writeback tasks */ |
| 31 | struct workqueue_struct *bdi_wq; |
| 32 | |
Miklos Szeredi | 76f1418 | 2008-04-30 00:54:36 -0700 | [diff] [blame] | 33 | #ifdef CONFIG_DEBUG_FS |
| 34 | #include <linux/debugfs.h> |
| 35 | #include <linux/seq_file.h> |
| 36 | |
| 37 | static struct dentry *bdi_debug_root; |
| 38 | |
| 39 | static void bdi_debug_init(void) |
| 40 | { |
| 41 | bdi_debug_root = debugfs_create_dir("bdi", NULL); |
| 42 | } |
| 43 | |
| 44 | static int bdi_debug_stats_show(struct seq_file *m, void *v) |
| 45 | { |
| 46 | struct backing_dev_info *bdi = m->private; |
Christoph Hellwig | c1955ce | 2010-06-19 23:08:06 +0200 | [diff] [blame] | 47 | struct bdi_writeback *wb = &bdi->wb; |
David Rientjes | 364aeb2 | 2009-01-06 14:39:29 -0800 | [diff] [blame] | 48 | unsigned long background_thresh; |
| 49 | unsigned long dirty_thresh; |
Tejun Heo | 0d960a3 | 2015-05-22 18:23:19 -0400 | [diff] [blame] | 50 | unsigned long wb_thresh; |
Theodore Ts'o | 0ae45f6 | 2015-02-02 00:37:00 -0500 | [diff] [blame] | 51 | unsigned long nr_dirty, nr_io, nr_more_io, nr_dirty_time; |
Jens Axboe | f09b00d | 2009-05-25 09:08:21 +0200 | [diff] [blame] | 52 | struct inode *inode; |
| 53 | |
Theodore Ts'o | 0ae45f6 | 2015-02-02 00:37:00 -0500 | [diff] [blame] | 54 | nr_dirty = nr_io = nr_more_io = nr_dirty_time = 0; |
Christoph Hellwig | f758eea | 2011-04-21 18:19:44 -0600 | [diff] [blame] | 55 | spin_lock(&wb->list_lock); |
Dave Chinner | c7f5408 | 2015-03-04 14:07:22 -0500 | [diff] [blame] | 56 | list_for_each_entry(inode, &wb->b_dirty, i_io_list) |
Christoph Hellwig | c1955ce | 2010-06-19 23:08:06 +0200 | [diff] [blame] | 57 | nr_dirty++; |
Dave Chinner | c7f5408 | 2015-03-04 14:07:22 -0500 | [diff] [blame] | 58 | list_for_each_entry(inode, &wb->b_io, i_io_list) |
Christoph Hellwig | c1955ce | 2010-06-19 23:08:06 +0200 | [diff] [blame] | 59 | nr_io++; |
Dave Chinner | c7f5408 | 2015-03-04 14:07:22 -0500 | [diff] [blame] | 60 | list_for_each_entry(inode, &wb->b_more_io, i_io_list) |
Christoph Hellwig | c1955ce | 2010-06-19 23:08:06 +0200 | [diff] [blame] | 61 | nr_more_io++; |
Dave Chinner | c7f5408 | 2015-03-04 14:07:22 -0500 | [diff] [blame] | 62 | list_for_each_entry(inode, &wb->b_dirty_time, i_io_list) |
Theodore Ts'o | 0ae45f6 | 2015-02-02 00:37:00 -0500 | [diff] [blame] | 63 | if (inode->i_state & I_DIRTY_TIME) |
| 64 | nr_dirty_time++; |
Christoph Hellwig | f758eea | 2011-04-21 18:19:44 -0600 | [diff] [blame] | 65 | spin_unlock(&wb->list_lock); |
Miklos Szeredi | 76f1418 | 2008-04-30 00:54:36 -0700 | [diff] [blame] | 66 | |
Wu Fengguang | 16c4042 | 2010-08-11 14:17:39 -0700 | [diff] [blame] | 67 | global_dirty_limits(&background_thresh, &dirty_thresh); |
Tejun Heo | 0d960a3 | 2015-05-22 18:23:19 -0400 | [diff] [blame] | 68 | wb_thresh = wb_calc_thresh(wb, dirty_thresh); |
Miklos Szeredi | 76f1418 | 2008-04-30 00:54:36 -0700 | [diff] [blame] | 69 | |
| 70 | #define K(x) ((x) << (PAGE_SHIFT - 10)) |
| 71 | seq_printf(m, |
Wu Fengguang | 00821b0 | 2010-08-29 11:28:45 -0600 | [diff] [blame] | 72 | "BdiWriteback: %10lu kB\n" |
| 73 | "BdiReclaimable: %10lu kB\n" |
| 74 | "BdiDirtyThresh: %10lu kB\n" |
| 75 | "DirtyThresh: %10lu kB\n" |
| 76 | "BackgroundThresh: %10lu kB\n" |
Wu Fengguang | c8e28ce | 2011-01-23 10:07:47 -0600 | [diff] [blame] | 77 | "BdiDirtied: %10lu kB\n" |
Wu Fengguang | 00821b0 | 2010-08-29 11:28:45 -0600 | [diff] [blame] | 78 | "BdiWritten: %10lu kB\n" |
| 79 | "BdiWriteBandwidth: %10lu kBps\n" |
| 80 | "b_dirty: %10lu\n" |
| 81 | "b_io: %10lu\n" |
| 82 | "b_more_io: %10lu\n" |
Theodore Ts'o | 0ae45f6 | 2015-02-02 00:37:00 -0500 | [diff] [blame] | 83 | "b_dirty_time: %10lu\n" |
Wu Fengguang | 00821b0 | 2010-08-29 11:28:45 -0600 | [diff] [blame] | 84 | "bdi_list: %10u\n" |
| 85 | "state: %10lx\n", |
Tejun Heo | 93f78d8 | 2015-05-22 17:13:27 -0400 | [diff] [blame] | 86 | (unsigned long) K(wb_stat(wb, WB_WRITEBACK)), |
| 87 | (unsigned long) K(wb_stat(wb, WB_RECLAIMABLE)), |
Tejun Heo | 0d960a3 | 2015-05-22 18:23:19 -0400 | [diff] [blame] | 88 | K(wb_thresh), |
Jan Kara | f7d2b1e | 2010-12-08 22:44:24 -0600 | [diff] [blame] | 89 | K(dirty_thresh), |
| 90 | K(background_thresh), |
Tejun Heo | 93f78d8 | 2015-05-22 17:13:27 -0400 | [diff] [blame] | 91 | (unsigned long) K(wb_stat(wb, WB_DIRTIED)), |
| 92 | (unsigned long) K(wb_stat(wb, WB_WRITTEN)), |
Tejun Heo | a88a341 | 2015-05-22 17:13:28 -0400 | [diff] [blame] | 93 | (unsigned long) K(wb->write_bandwidth), |
Jan Kara | f7d2b1e | 2010-12-08 22:44:24 -0600 | [diff] [blame] | 94 | nr_dirty, |
| 95 | nr_io, |
| 96 | nr_more_io, |
Theodore Ts'o | 0ae45f6 | 2015-02-02 00:37:00 -0500 | [diff] [blame] | 97 | nr_dirty_time, |
Tejun Heo | 4452226 | 2015-05-22 17:13:26 -0400 | [diff] [blame] | 98 | !list_empty(&bdi->bdi_list), bdi->wb.state); |
Miklos Szeredi | 76f1418 | 2008-04-30 00:54:36 -0700 | [diff] [blame] | 99 | #undef K |
| 100 | |
| 101 | return 0; |
| 102 | } |
Andy Shevchenko | 5ad3509 | 2018-04-05 16:23:16 -0700 | [diff] [blame] | 103 | DEFINE_SHOW_ATTRIBUTE(bdi_debug_stats); |
Miklos Szeredi | 76f1418 | 2008-04-30 00:54:36 -0700 | [diff] [blame] | 104 | |
weiping zhang | 97f0769 | 2017-10-31 18:37:54 +0800 | [diff] [blame] | 105 | static int bdi_debug_register(struct backing_dev_info *bdi, const char *name) |
Miklos Szeredi | 76f1418 | 2008-04-30 00:54:36 -0700 | [diff] [blame] | 106 | { |
weiping zhang | 97f0769 | 2017-10-31 18:37:54 +0800 | [diff] [blame] | 107 | if (!bdi_debug_root) |
| 108 | return -ENOMEM; |
| 109 | |
Miklos Szeredi | 76f1418 | 2008-04-30 00:54:36 -0700 | [diff] [blame] | 110 | bdi->debug_dir = debugfs_create_dir(name, bdi_debug_root); |
weiping zhang | 97f0769 | 2017-10-31 18:37:54 +0800 | [diff] [blame] | 111 | if (!bdi->debug_dir) |
| 112 | return -ENOMEM; |
| 113 | |
Miklos Szeredi | 76f1418 | 2008-04-30 00:54:36 -0700 | [diff] [blame] | 114 | bdi->debug_stats = debugfs_create_file("stats", 0444, bdi->debug_dir, |
| 115 | bdi, &bdi_debug_stats_fops); |
weiping zhang | 97f0769 | 2017-10-31 18:37:54 +0800 | [diff] [blame] | 116 | if (!bdi->debug_stats) { |
| 117 | debugfs_remove(bdi->debug_dir); |
Tetsuo Handa | f53823c | 2018-04-23 11:21:03 +0900 | [diff] [blame] | 118 | bdi->debug_dir = NULL; |
weiping zhang | 97f0769 | 2017-10-31 18:37:54 +0800 | [diff] [blame] | 119 | return -ENOMEM; |
| 120 | } |
| 121 | |
| 122 | return 0; |
Miklos Szeredi | 76f1418 | 2008-04-30 00:54:36 -0700 | [diff] [blame] | 123 | } |
| 124 | |
| 125 | static void bdi_debug_unregister(struct backing_dev_info *bdi) |
| 126 | { |
| 127 | debugfs_remove(bdi->debug_stats); |
| 128 | debugfs_remove(bdi->debug_dir); |
| 129 | } |
| 130 | #else |
| 131 | static inline void bdi_debug_init(void) |
| 132 | { |
| 133 | } |
weiping zhang | 97f0769 | 2017-10-31 18:37:54 +0800 | [diff] [blame] | 134 | static inline int bdi_debug_register(struct backing_dev_info *bdi, |
Miklos Szeredi | 76f1418 | 2008-04-30 00:54:36 -0700 | [diff] [blame] | 135 | const char *name) |
| 136 | { |
weiping zhang | 97f0769 | 2017-10-31 18:37:54 +0800 | [diff] [blame] | 137 | return 0; |
Miklos Szeredi | 76f1418 | 2008-04-30 00:54:36 -0700 | [diff] [blame] | 138 | } |
| 139 | static inline void bdi_debug_unregister(struct backing_dev_info *bdi) |
| 140 | { |
| 141 | } |
| 142 | #endif |
| 143 | |
Peter Zijlstra | cf0ca9f | 2008-04-30 00:54:32 -0700 | [diff] [blame] | 144 | static ssize_t read_ahead_kb_store(struct device *dev, |
| 145 | struct device_attribute *attr, |
| 146 | const char *buf, size_t count) |
| 147 | { |
| 148 | struct backing_dev_info *bdi = dev_get_drvdata(dev); |
Peter Zijlstra | cf0ca9f | 2008-04-30 00:54:32 -0700 | [diff] [blame] | 149 | unsigned long read_ahead_kb; |
Namjae Jeon | 7034ed1 | 2012-08-25 16:57:27 +0800 | [diff] [blame] | 150 | ssize_t ret; |
Peter Zijlstra | cf0ca9f | 2008-04-30 00:54:32 -0700 | [diff] [blame] | 151 | |
Namjae Jeon | 7034ed1 | 2012-08-25 16:57:27 +0800 | [diff] [blame] | 152 | ret = kstrtoul(buf, 10, &read_ahead_kb); |
| 153 | if (ret < 0) |
| 154 | return ret; |
| 155 | |
| 156 | bdi->ra_pages = read_ahead_kb >> (PAGE_SHIFT - 10); |
| 157 | |
| 158 | return count; |
Peter Zijlstra | cf0ca9f | 2008-04-30 00:54:32 -0700 | [diff] [blame] | 159 | } |
| 160 | |
| 161 | #define K(pages) ((pages) << (PAGE_SHIFT - 10)) |
| 162 | |
| 163 | #define BDI_SHOW(name, expr) \ |
| 164 | static ssize_t name##_show(struct device *dev, \ |
| 165 | struct device_attribute *attr, char *page) \ |
| 166 | { \ |
| 167 | struct backing_dev_info *bdi = dev_get_drvdata(dev); \ |
| 168 | \ |
| 169 | return snprintf(page, PAGE_SIZE-1, "%lld\n", (long long)expr); \ |
Greg Kroah-Hartman | d9e1241 | 2013-07-24 15:05:26 -0700 | [diff] [blame] | 170 | } \ |
| 171 | static DEVICE_ATTR_RW(name); |
Peter Zijlstra | cf0ca9f | 2008-04-30 00:54:32 -0700 | [diff] [blame] | 172 | |
| 173 | BDI_SHOW(read_ahead_kb, K(bdi->ra_pages)) |
| 174 | |
Peter Zijlstra | 189d3c4 | 2008-04-30 00:54:35 -0700 | [diff] [blame] | 175 | static ssize_t min_ratio_store(struct device *dev, |
| 176 | struct device_attribute *attr, const char *buf, size_t count) |
| 177 | { |
| 178 | struct backing_dev_info *bdi = dev_get_drvdata(dev); |
Peter Zijlstra | 189d3c4 | 2008-04-30 00:54:35 -0700 | [diff] [blame] | 179 | unsigned int ratio; |
Namjae Jeon | 7034ed1 | 2012-08-25 16:57:27 +0800 | [diff] [blame] | 180 | ssize_t ret; |
Peter Zijlstra | 189d3c4 | 2008-04-30 00:54:35 -0700 | [diff] [blame] | 181 | |
Namjae Jeon | 7034ed1 | 2012-08-25 16:57:27 +0800 | [diff] [blame] | 182 | ret = kstrtouint(buf, 10, &ratio); |
| 183 | if (ret < 0) |
| 184 | return ret; |
| 185 | |
| 186 | ret = bdi_set_min_ratio(bdi, ratio); |
| 187 | if (!ret) |
| 188 | ret = count; |
| 189 | |
Peter Zijlstra | 189d3c4 | 2008-04-30 00:54:35 -0700 | [diff] [blame] | 190 | return ret; |
| 191 | } |
| 192 | BDI_SHOW(min_ratio, bdi->min_ratio) |
| 193 | |
Peter Zijlstra | a42dde0 | 2008-04-30 00:54:36 -0700 | [diff] [blame] | 194 | static ssize_t max_ratio_store(struct device *dev, |
| 195 | struct device_attribute *attr, const char *buf, size_t count) |
| 196 | { |
| 197 | struct backing_dev_info *bdi = dev_get_drvdata(dev); |
Peter Zijlstra | a42dde0 | 2008-04-30 00:54:36 -0700 | [diff] [blame] | 198 | unsigned int ratio; |
Namjae Jeon | 7034ed1 | 2012-08-25 16:57:27 +0800 | [diff] [blame] | 199 | ssize_t ret; |
Peter Zijlstra | a42dde0 | 2008-04-30 00:54:36 -0700 | [diff] [blame] | 200 | |
Namjae Jeon | 7034ed1 | 2012-08-25 16:57:27 +0800 | [diff] [blame] | 201 | ret = kstrtouint(buf, 10, &ratio); |
| 202 | if (ret < 0) |
| 203 | return ret; |
| 204 | |
| 205 | ret = bdi_set_max_ratio(bdi, ratio); |
| 206 | if (!ret) |
| 207 | ret = count; |
| 208 | |
Peter Zijlstra | a42dde0 | 2008-04-30 00:54:36 -0700 | [diff] [blame] | 209 | return ret; |
| 210 | } |
| 211 | BDI_SHOW(max_ratio, bdi->max_ratio) |
| 212 | |
Darrick J. Wong | 7d311cd | 2013-02-21 16:42:48 -0800 | [diff] [blame] | 213 | static ssize_t stable_pages_required_show(struct device *dev, |
| 214 | struct device_attribute *attr, |
| 215 | char *page) |
| 216 | { |
| 217 | struct backing_dev_info *bdi = dev_get_drvdata(dev); |
| 218 | |
| 219 | return snprintf(page, PAGE_SIZE-1, "%d\n", |
| 220 | bdi_cap_stable_pages_required(bdi) ? 1 : 0); |
| 221 | } |
Greg Kroah-Hartman | d9e1241 | 2013-07-24 15:05:26 -0700 | [diff] [blame] | 222 | static DEVICE_ATTR_RO(stable_pages_required); |
Darrick J. Wong | 7d311cd | 2013-02-21 16:42:48 -0800 | [diff] [blame] | 223 | |
Greg Kroah-Hartman | d9e1241 | 2013-07-24 15:05:26 -0700 | [diff] [blame] | 224 | static struct attribute *bdi_dev_attrs[] = { |
| 225 | &dev_attr_read_ahead_kb.attr, |
| 226 | &dev_attr_min_ratio.attr, |
| 227 | &dev_attr_max_ratio.attr, |
| 228 | &dev_attr_stable_pages_required.attr, |
| 229 | NULL, |
Peter Zijlstra | cf0ca9f | 2008-04-30 00:54:32 -0700 | [diff] [blame] | 230 | }; |
Greg Kroah-Hartman | d9e1241 | 2013-07-24 15:05:26 -0700 | [diff] [blame] | 231 | ATTRIBUTE_GROUPS(bdi_dev); |
Peter Zijlstra | cf0ca9f | 2008-04-30 00:54:32 -0700 | [diff] [blame] | 232 | |
| 233 | static __init int bdi_class_init(void) |
| 234 | { |
| 235 | bdi_class = class_create(THIS_MODULE, "bdi"); |
Anton Blanchard | 1442145 | 2010-04-02 09:46:55 +0200 | [diff] [blame] | 236 | if (IS_ERR(bdi_class)) |
| 237 | return PTR_ERR(bdi_class); |
| 238 | |
Greg Kroah-Hartman | d9e1241 | 2013-07-24 15:05:26 -0700 | [diff] [blame] | 239 | bdi_class->dev_groups = bdi_dev_groups; |
Miklos Szeredi | 76f1418 | 2008-04-30 00:54:36 -0700 | [diff] [blame] | 240 | bdi_debug_init(); |
Jan Kara | d03f6cd | 2017-02-02 15:56:51 +0100 | [diff] [blame] | 241 | |
Peter Zijlstra | cf0ca9f | 2008-04-30 00:54:32 -0700 | [diff] [blame] | 242 | return 0; |
| 243 | } |
Miklos Szeredi | 76f1418 | 2008-04-30 00:54:36 -0700 | [diff] [blame] | 244 | postcore_initcall(bdi_class_init); |
Peter Zijlstra | cf0ca9f | 2008-04-30 00:54:32 -0700 | [diff] [blame] | 245 | |
Jan Kara | 2e82b84 | 2017-04-12 12:24:48 +0200 | [diff] [blame] | 246 | static int bdi_init(struct backing_dev_info *bdi); |
| 247 | |
Jens Axboe | 2616015 | 2009-03-17 09:35:06 +0100 | [diff] [blame] | 248 | static int __init default_bdi_init(void) |
| 249 | { |
| 250 | int err; |
| 251 | |
Tejun Heo | 839a8e8 | 2013-04-01 19:08:06 -0700 | [diff] [blame] | 252 | bdi_wq = alloc_workqueue("writeback", WQ_MEM_RECLAIM | WQ_FREEZABLE | |
Tejun Heo | b5c872d | 2013-04-01 19:08:06 -0700 | [diff] [blame] | 253 | WQ_UNBOUND | WQ_SYSFS, 0); |
Tejun Heo | 839a8e8 | 2013-04-01 19:08:06 -0700 | [diff] [blame] | 254 | if (!bdi_wq) |
| 255 | return -ENOMEM; |
| 256 | |
Jan Kara | 976e48f | 2010-09-21 11:48:55 +0200 | [diff] [blame] | 257 | err = bdi_init(&noop_backing_dev_info); |
Jens Axboe | 2616015 | 2009-03-17 09:35:06 +0100 | [diff] [blame] | 258 | |
| 259 | return err; |
| 260 | } |
| 261 | subsys_initcall(default_bdi_init); |
| 262 | |
Artem Bityutskiy | 6467716 | 2010-07-25 14:29:22 +0300 | [diff] [blame] | 263 | /* |
Tejun Heo | f0054bb | 2015-05-22 17:13:30 -0400 | [diff] [blame] | 264 | * This function is used when the first inode for this wb is marked dirty. It |
Artem Bityutskiy | 6467716 | 2010-07-25 14:29:22 +0300 | [diff] [blame] | 265 | * wakes-up the corresponding bdi thread which should then take care of the |
| 266 | * periodic background write-out of dirty inodes. Since the write-out would |
| 267 | * starts only 'dirty_writeback_interval' centisecs from now anyway, we just |
| 268 | * set up a timer which wakes the bdi thread up later. |
| 269 | * |
| 270 | * Note, we wouldn't bother setting up the timer, but this function is on the |
| 271 | * fast-path (used by '__mark_inode_dirty()'), so we save few context switches |
| 272 | * by delaying the wake-up. |
Derek Basehore | 6ca738d | 2014-04-03 14:46:22 -0700 | [diff] [blame] | 273 | * |
| 274 | * We have to be careful not to postpone flush work if it is scheduled for |
| 275 | * earlier. Thus we use queue_delayed_work(). |
Artem Bityutskiy | 6467716 | 2010-07-25 14:29:22 +0300 | [diff] [blame] | 276 | */ |
Tejun Heo | f0054bb | 2015-05-22 17:13:30 -0400 | [diff] [blame] | 277 | void wb_wakeup_delayed(struct bdi_writeback *wb) |
Artem Bityutskiy | 6467716 | 2010-07-25 14:29:22 +0300 | [diff] [blame] | 278 | { |
| 279 | unsigned long timeout; |
| 280 | |
| 281 | timeout = msecs_to_jiffies(dirty_writeback_interval * 10); |
Tejun Heo | f0054bb | 2015-05-22 17:13:30 -0400 | [diff] [blame] | 282 | spin_lock_bh(&wb->work_lock); |
| 283 | if (test_bit(WB_registered, &wb->state)) |
| 284 | queue_delayed_work(bdi_wq, &wb->dwork, timeout); |
| 285 | spin_unlock_bh(&wb->work_lock); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 286 | } |
| 287 | |
Jens Axboe | cfc4ba5 | 2009-09-14 13:12:40 +0200 | [diff] [blame] | 288 | /* |
Tejun Heo | a88a341 | 2015-05-22 17:13:28 -0400 | [diff] [blame] | 289 | * Initial write bandwidth: 100 MB/s |
Jens Axboe | cfc4ba5 | 2009-09-14 13:12:40 +0200 | [diff] [blame] | 290 | */ |
Tejun Heo | a88a341 | 2015-05-22 17:13:28 -0400 | [diff] [blame] | 291 | #define INIT_BW (100 << (20 - PAGE_SHIFT)) |
Jens Axboe | cfc4ba5 | 2009-09-14 13:12:40 +0200 | [diff] [blame] | 292 | |
Tejun Heo | 8395cd9 | 2015-05-22 17:13:34 -0400 | [diff] [blame] | 293 | static int wb_init(struct bdi_writeback *wb, struct backing_dev_info *bdi, |
Tejun Heo | a13f35e | 2015-07-02 08:44:34 -0600 | [diff] [blame] | 294 | int blkcg_id, gfp_t gfp) |
Artem Bityutskiy | 6467716 | 2010-07-25 14:29:22 +0300 | [diff] [blame] | 295 | { |
Tejun Heo | 93f78d8 | 2015-05-22 17:13:27 -0400 | [diff] [blame] | 296 | int i, err; |
| 297 | |
Artem Bityutskiy | 6467716 | 2010-07-25 14:29:22 +0300 | [diff] [blame] | 298 | memset(wb, 0, sizeof(*wb)); |
| 299 | |
Jan Kara | 810df54 | 2017-03-23 01:36:55 +0100 | [diff] [blame] | 300 | if (wb != &bdi->wb) |
| 301 | bdi_get(bdi); |
Artem Bityutskiy | 6467716 | 2010-07-25 14:29:22 +0300 | [diff] [blame] | 302 | wb->bdi = bdi; |
| 303 | wb->last_old_flush = jiffies; |
| 304 | INIT_LIST_HEAD(&wb->b_dirty); |
| 305 | INIT_LIST_HEAD(&wb->b_io); |
| 306 | INIT_LIST_HEAD(&wb->b_more_io); |
Theodore Ts'o | 0ae45f6 | 2015-02-02 00:37:00 -0500 | [diff] [blame] | 307 | INIT_LIST_HEAD(&wb->b_dirty_time); |
Christoph Hellwig | f758eea | 2011-04-21 18:19:44 -0600 | [diff] [blame] | 308 | spin_lock_init(&wb->list_lock); |
Tejun Heo | 93f78d8 | 2015-05-22 17:13:27 -0400 | [diff] [blame] | 309 | |
Tejun Heo | a88a341 | 2015-05-22 17:13:28 -0400 | [diff] [blame] | 310 | wb->bw_time_stamp = jiffies; |
| 311 | wb->balanced_dirty_ratelimit = INIT_BW; |
| 312 | wb->dirty_ratelimit = INIT_BW; |
| 313 | wb->write_bandwidth = INIT_BW; |
| 314 | wb->avg_write_bandwidth = INIT_BW; |
| 315 | |
Tejun Heo | f0054bb | 2015-05-22 17:13:30 -0400 | [diff] [blame] | 316 | spin_lock_init(&wb->work_lock); |
| 317 | INIT_LIST_HEAD(&wb->work_list); |
| 318 | INIT_DELAYED_WORK(&wb->dwork, wb_workfn); |
Jens Axboe | b57d74a | 2016-09-01 10:20:33 -0600 | [diff] [blame] | 319 | wb->dirty_sleep = jiffies; |
Tejun Heo | f0054bb | 2015-05-22 17:13:30 -0400 | [diff] [blame] | 320 | |
Tejun Heo | a13f35e | 2015-07-02 08:44:34 -0600 | [diff] [blame] | 321 | wb->congested = wb_congested_get_create(bdi, blkcg_id, gfp); |
Jan Kara | 810df54 | 2017-03-23 01:36:55 +0100 | [diff] [blame] | 322 | if (!wb->congested) { |
| 323 | err = -ENOMEM; |
| 324 | goto out_put_bdi; |
| 325 | } |
Tejun Heo | a13f35e | 2015-07-02 08:44:34 -0600 | [diff] [blame] | 326 | |
Tejun Heo | 8395cd9 | 2015-05-22 17:13:34 -0400 | [diff] [blame] | 327 | err = fprop_local_init_percpu(&wb->completions, gfp); |
Tejun Heo | a88a341 | 2015-05-22 17:13:28 -0400 | [diff] [blame] | 328 | if (err) |
Tejun Heo | a13f35e | 2015-07-02 08:44:34 -0600 | [diff] [blame] | 329 | goto out_put_cong; |
Tejun Heo | a88a341 | 2015-05-22 17:13:28 -0400 | [diff] [blame] | 330 | |
Tejun Heo | 93f78d8 | 2015-05-22 17:13:27 -0400 | [diff] [blame] | 331 | for (i = 0; i < NR_WB_STAT_ITEMS; i++) { |
Tejun Heo | 8395cd9 | 2015-05-22 17:13:34 -0400 | [diff] [blame] | 332 | err = percpu_counter_init(&wb->stat[i], 0, gfp); |
Tejun Heo | a13f35e | 2015-07-02 08:44:34 -0600 | [diff] [blame] | 333 | if (err) |
| 334 | goto out_destroy_stat; |
Tejun Heo | 93f78d8 | 2015-05-22 17:13:27 -0400 | [diff] [blame] | 335 | } |
| 336 | |
| 337 | return 0; |
Tejun Heo | a13f35e | 2015-07-02 08:44:34 -0600 | [diff] [blame] | 338 | |
| 339 | out_destroy_stat: |
Rasmus Villemoes | 078c6c3 | 2016-02-11 16:13:06 -0800 | [diff] [blame] | 340 | while (i--) |
Tejun Heo | a13f35e | 2015-07-02 08:44:34 -0600 | [diff] [blame] | 341 | percpu_counter_destroy(&wb->stat[i]); |
| 342 | fprop_local_destroy_percpu(&wb->completions); |
| 343 | out_put_cong: |
| 344 | wb_congested_put(wb->congested); |
Jan Kara | 810df54 | 2017-03-23 01:36:55 +0100 | [diff] [blame] | 345 | out_put_bdi: |
| 346 | if (wb != &bdi->wb) |
| 347 | bdi_put(bdi); |
Tejun Heo | a13f35e | 2015-07-02 08:44:34 -0600 | [diff] [blame] | 348 | return err; |
Peter Zijlstra | cf0ca9f | 2008-04-30 00:54:32 -0700 | [diff] [blame] | 349 | } |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 350 | |
Jan Kara | e8cb72b | 2017-03-23 01:36:56 +0100 | [diff] [blame] | 351 | static void cgwb_remove_from_bdi_list(struct bdi_writeback *wb); |
| 352 | |
Tejun Heo | 4610007 | 2015-05-22 17:13:31 -0400 | [diff] [blame] | 353 | /* |
| 354 | * Remove bdi from the global list and shutdown any threads we have running |
| 355 | */ |
| 356 | static void wb_shutdown(struct bdi_writeback *wb) |
| 357 | { |
| 358 | /* Make sure nobody queues further work */ |
| 359 | spin_lock_bh(&wb->work_lock); |
| 360 | if (!test_and_clear_bit(WB_registered, &wb->state)) { |
| 361 | spin_unlock_bh(&wb->work_lock); |
Jan Kara | 5318ce7 | 2017-03-23 01:36:57 +0100 | [diff] [blame] | 362 | /* |
| 363 | * Wait for wb shutdown to finish if someone else is just |
| 364 | * running wb_shutdown(). Otherwise we could proceed to wb / |
| 365 | * bdi destruction before wb_shutdown() is finished. |
| 366 | */ |
| 367 | wait_on_bit(&wb->state, WB_shutting_down, TASK_UNINTERRUPTIBLE); |
Tejun Heo | 4610007 | 2015-05-22 17:13:31 -0400 | [diff] [blame] | 368 | return; |
| 369 | } |
Jan Kara | 5318ce7 | 2017-03-23 01:36:57 +0100 | [diff] [blame] | 370 | set_bit(WB_shutting_down, &wb->state); |
Tejun Heo | 4610007 | 2015-05-22 17:13:31 -0400 | [diff] [blame] | 371 | spin_unlock_bh(&wb->work_lock); |
| 372 | |
Jan Kara | e8cb72b | 2017-03-23 01:36:56 +0100 | [diff] [blame] | 373 | cgwb_remove_from_bdi_list(wb); |
Tejun Heo | 4610007 | 2015-05-22 17:13:31 -0400 | [diff] [blame] | 374 | /* |
| 375 | * Drain work list and shutdown the delayed_work. !WB_registered |
| 376 | * tells wb_workfn() that @wb is dying and its work_list needs to |
| 377 | * be drained no matter what. |
| 378 | */ |
| 379 | mod_delayed_work(bdi_wq, &wb->dwork, 0); |
| 380 | flush_delayed_work(&wb->dwork); |
| 381 | WARN_ON(!list_empty(&wb->work_list)); |
Jan Kara | 5318ce7 | 2017-03-23 01:36:57 +0100 | [diff] [blame] | 382 | /* |
| 383 | * Make sure bit gets cleared after shutdown is finished. Matches with |
| 384 | * the barrier provided by test_and_clear_bit() above. |
| 385 | */ |
| 386 | smp_wmb(); |
Tetsuo Handa | 8236b0a | 2018-05-02 07:07:55 +0900 | [diff] [blame] | 387 | clear_and_wake_up_bit(WB_shutting_down, &wb->state); |
Tejun Heo | 4610007 | 2015-05-22 17:13:31 -0400 | [diff] [blame] | 388 | } |
| 389 | |
Tejun Heo | f0054bb | 2015-05-22 17:13:30 -0400 | [diff] [blame] | 390 | static void wb_exit(struct bdi_writeback *wb) |
Tejun Heo | 93f78d8 | 2015-05-22 17:13:27 -0400 | [diff] [blame] | 391 | { |
| 392 | int i; |
| 393 | |
| 394 | WARN_ON(delayed_work_pending(&wb->dwork)); |
| 395 | |
| 396 | for (i = 0; i < NR_WB_STAT_ITEMS; i++) |
| 397 | percpu_counter_destroy(&wb->stat[i]); |
Artem Bityutskiy | 6467716 | 2010-07-25 14:29:22 +0300 | [diff] [blame] | 398 | |
Tejun Heo | a88a341 | 2015-05-22 17:13:28 -0400 | [diff] [blame] | 399 | fprop_local_destroy_percpu(&wb->completions); |
Tejun Heo | a13f35e | 2015-07-02 08:44:34 -0600 | [diff] [blame] | 400 | wb_congested_put(wb->congested); |
Jan Kara | 810df54 | 2017-03-23 01:36:55 +0100 | [diff] [blame] | 401 | if (wb != &wb->bdi->wb) |
| 402 | bdi_put(wb->bdi); |
Tejun Heo | a88a341 | 2015-05-22 17:13:28 -0400 | [diff] [blame] | 403 | } |
Wu Fengguang | e98be2d | 2010-08-29 11:22:30 -0600 | [diff] [blame] | 404 | |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 405 | #ifdef CONFIG_CGROUP_WRITEBACK |
| 406 | |
| 407 | #include <linux/memcontrol.h> |
| 408 | |
| 409 | /* |
| 410 | * cgwb_lock protects bdi->cgwb_tree, bdi->cgwb_congested_tree, |
| 411 | * blkcg->cgwb_list, and memcg->cgwb_list. bdi->cgwb_tree is also RCU |
Jan Kara | 4514451 | 2017-03-23 01:36:58 +0100 | [diff] [blame] | 412 | * protected. |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 413 | */ |
| 414 | static DEFINE_SPINLOCK(cgwb_lock); |
Tejun Heo | f183464 | 2018-05-23 10:56:32 -0700 | [diff] [blame] | 415 | static struct workqueue_struct *cgwb_release_wq; |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 416 | |
| 417 | /** |
| 418 | * wb_congested_get_create - get or create a wb_congested |
| 419 | * @bdi: associated bdi |
| 420 | * @blkcg_id: ID of the associated blkcg |
| 421 | * @gfp: allocation mask |
| 422 | * |
| 423 | * Look up the wb_congested for @blkcg_id on @bdi. If missing, create one. |
| 424 | * The returned wb_congested has its reference count incremented. Returns |
| 425 | * NULL on failure. |
| 426 | */ |
| 427 | struct bdi_writeback_congested * |
| 428 | wb_congested_get_create(struct backing_dev_info *bdi, int blkcg_id, gfp_t gfp) |
| 429 | { |
| 430 | struct bdi_writeback_congested *new_congested = NULL, *congested; |
| 431 | struct rb_node **node, *parent; |
| 432 | unsigned long flags; |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 433 | retry: |
| 434 | spin_lock_irqsave(&cgwb_lock, flags); |
| 435 | |
| 436 | node = &bdi->cgwb_congested_tree.rb_node; |
| 437 | parent = NULL; |
| 438 | |
| 439 | while (*node != NULL) { |
| 440 | parent = *node; |
Geliang Tang | bc71226 | 2017-02-22 15:45:52 -0800 | [diff] [blame] | 441 | congested = rb_entry(parent, struct bdi_writeback_congested, |
| 442 | rb_node); |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 443 | if (congested->blkcg_id < blkcg_id) |
| 444 | node = &parent->rb_left; |
| 445 | else if (congested->blkcg_id > blkcg_id) |
| 446 | node = &parent->rb_right; |
| 447 | else |
| 448 | goto found; |
| 449 | } |
| 450 | |
| 451 | if (new_congested) { |
| 452 | /* !found and storage for new one already allocated, insert */ |
| 453 | congested = new_congested; |
| 454 | new_congested = NULL; |
| 455 | rb_link_node(&congested->rb_node, parent, node); |
| 456 | rb_insert_color(&congested->rb_node, &bdi->cgwb_congested_tree); |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 457 | goto found; |
| 458 | } |
| 459 | |
| 460 | spin_unlock_irqrestore(&cgwb_lock, flags); |
| 461 | |
| 462 | /* allocate storage for new one and retry */ |
| 463 | new_congested = kzalloc(sizeof(*new_congested), gfp); |
| 464 | if (!new_congested) |
| 465 | return NULL; |
| 466 | |
| 467 | atomic_set(&new_congested->refcnt, 0); |
Jan Kara | b7d680d | 2017-03-23 01:36:54 +0100 | [diff] [blame] | 468 | new_congested->__bdi = bdi; |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 469 | new_congested->blkcg_id = blkcg_id; |
| 470 | goto retry; |
| 471 | |
| 472 | found: |
| 473 | atomic_inc(&congested->refcnt); |
| 474 | spin_unlock_irqrestore(&cgwb_lock, flags); |
| 475 | kfree(new_congested); |
| 476 | return congested; |
| 477 | } |
| 478 | |
| 479 | /** |
| 480 | * wb_congested_put - put a wb_congested |
| 481 | * @congested: wb_congested to put |
| 482 | * |
| 483 | * Put @congested and destroy it if the refcnt reaches zero. |
| 484 | */ |
| 485 | void wb_congested_put(struct bdi_writeback_congested *congested) |
| 486 | { |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 487 | unsigned long flags; |
| 488 | |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 489 | local_irq_save(flags); |
| 490 | if (!atomic_dec_and_lock(&congested->refcnt, &cgwb_lock)) { |
| 491 | local_irq_restore(flags); |
| 492 | return; |
| 493 | } |
| 494 | |
Tejun Heo | a20135f | 2015-07-01 20:53:37 -0400 | [diff] [blame] | 495 | /* bdi might already have been destroyed leaving @congested unlinked */ |
Jan Kara | b7d680d | 2017-03-23 01:36:54 +0100 | [diff] [blame] | 496 | if (congested->__bdi) { |
Tejun Heo | a20135f | 2015-07-01 20:53:37 -0400 | [diff] [blame] | 497 | rb_erase(&congested->rb_node, |
Jan Kara | b7d680d | 2017-03-23 01:36:54 +0100 | [diff] [blame] | 498 | &congested->__bdi->cgwb_congested_tree); |
| 499 | congested->__bdi = NULL; |
Tejun Heo | a20135f | 2015-07-01 20:53:37 -0400 | [diff] [blame] | 500 | } |
| 501 | |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 502 | spin_unlock_irqrestore(&cgwb_lock, flags); |
| 503 | kfree(congested); |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 504 | } |
| 505 | |
| 506 | static void cgwb_release_workfn(struct work_struct *work) |
| 507 | { |
| 508 | struct bdi_writeback *wb = container_of(work, struct bdi_writeback, |
| 509 | release_work); |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 510 | |
| 511 | wb_shutdown(wb); |
| 512 | |
| 513 | css_put(wb->memcg_css); |
| 514 | css_put(wb->blkcg_css); |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 515 | |
Tejun Heo | 841710a | 2015-05-22 18:23:33 -0400 | [diff] [blame] | 516 | fprop_local_destroy_percpu(&wb->memcg_completions); |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 517 | percpu_ref_exit(&wb->refcnt); |
| 518 | wb_exit(wb); |
| 519 | kfree_rcu(wb, rcu); |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 520 | } |
| 521 | |
| 522 | static void cgwb_release(struct percpu_ref *refcnt) |
| 523 | { |
| 524 | struct bdi_writeback *wb = container_of(refcnt, struct bdi_writeback, |
| 525 | refcnt); |
Tejun Heo | f183464 | 2018-05-23 10:56:32 -0700 | [diff] [blame] | 526 | queue_work(cgwb_release_wq, &wb->release_work); |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 527 | } |
| 528 | |
| 529 | static void cgwb_kill(struct bdi_writeback *wb) |
| 530 | { |
| 531 | lockdep_assert_held(&cgwb_lock); |
| 532 | |
| 533 | WARN_ON(!radix_tree_delete(&wb->bdi->cgwb_tree, wb->memcg_css->id)); |
| 534 | list_del(&wb->memcg_node); |
| 535 | list_del(&wb->blkcg_node); |
| 536 | percpu_ref_kill(&wb->refcnt); |
| 537 | } |
| 538 | |
Jan Kara | e8cb72b | 2017-03-23 01:36:56 +0100 | [diff] [blame] | 539 | static void cgwb_remove_from_bdi_list(struct bdi_writeback *wb) |
| 540 | { |
| 541 | spin_lock_irq(&cgwb_lock); |
| 542 | list_del_rcu(&wb->bdi_node); |
| 543 | spin_unlock_irq(&cgwb_lock); |
| 544 | } |
| 545 | |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 546 | static int cgwb_create(struct backing_dev_info *bdi, |
| 547 | struct cgroup_subsys_state *memcg_css, gfp_t gfp) |
| 548 | { |
| 549 | struct mem_cgroup *memcg; |
| 550 | struct cgroup_subsys_state *blkcg_css; |
| 551 | struct blkcg *blkcg; |
| 552 | struct list_head *memcg_cgwb_list, *blkcg_cgwb_list; |
| 553 | struct bdi_writeback *wb; |
| 554 | unsigned long flags; |
| 555 | int ret = 0; |
| 556 | |
| 557 | memcg = mem_cgroup_from_css(memcg_css); |
Tejun Heo | c165b3e | 2015-08-18 14:55:29 -0700 | [diff] [blame] | 558 | blkcg_css = cgroup_get_e_css(memcg_css->cgroup, &io_cgrp_subsys); |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 559 | blkcg = css_to_blkcg(blkcg_css); |
Wang Long | 9ccc361 | 2018-06-07 17:07:19 -0700 | [diff] [blame^] | 560 | memcg_cgwb_list = &memcg->cgwb_list; |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 561 | blkcg_cgwb_list = &blkcg->cgwb_list; |
| 562 | |
| 563 | /* look up again under lock and discard on blkcg mismatch */ |
| 564 | spin_lock_irqsave(&cgwb_lock, flags); |
| 565 | wb = radix_tree_lookup(&bdi->cgwb_tree, memcg_css->id); |
| 566 | if (wb && wb->blkcg_css != blkcg_css) { |
| 567 | cgwb_kill(wb); |
| 568 | wb = NULL; |
| 569 | } |
| 570 | spin_unlock_irqrestore(&cgwb_lock, flags); |
| 571 | if (wb) |
| 572 | goto out_put; |
| 573 | |
| 574 | /* need to create a new one */ |
| 575 | wb = kmalloc(sizeof(*wb), gfp); |
Christophe JAILLET | 0b045bd | 2017-09-11 21:43:23 +0200 | [diff] [blame] | 576 | if (!wb) { |
| 577 | ret = -ENOMEM; |
| 578 | goto out_put; |
| 579 | } |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 580 | |
Tejun Heo | a13f35e | 2015-07-02 08:44:34 -0600 | [diff] [blame] | 581 | ret = wb_init(wb, bdi, blkcg_css->id, gfp); |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 582 | if (ret) |
| 583 | goto err_free; |
| 584 | |
| 585 | ret = percpu_ref_init(&wb->refcnt, cgwb_release, 0, gfp); |
| 586 | if (ret) |
| 587 | goto err_wb_exit; |
| 588 | |
Tejun Heo | 841710a | 2015-05-22 18:23:33 -0400 | [diff] [blame] | 589 | ret = fprop_local_init_percpu(&wb->memcg_completions, gfp); |
| 590 | if (ret) |
| 591 | goto err_ref_exit; |
| 592 | |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 593 | wb->memcg_css = memcg_css; |
| 594 | wb->blkcg_css = blkcg_css; |
| 595 | INIT_WORK(&wb->release_work, cgwb_release_workfn); |
| 596 | set_bit(WB_registered, &wb->state); |
| 597 | |
| 598 | /* |
| 599 | * The root wb determines the registered state of the whole bdi and |
| 600 | * memcg_cgwb_list and blkcg_cgwb_list's next pointers indicate |
| 601 | * whether they're still online. Don't link @wb if any is dead. |
| 602 | * See wb_memcg_offline() and wb_blkcg_offline(). |
| 603 | */ |
| 604 | ret = -ENODEV; |
| 605 | spin_lock_irqsave(&cgwb_lock, flags); |
| 606 | if (test_bit(WB_registered, &bdi->wb.state) && |
| 607 | blkcg_cgwb_list->next && memcg_cgwb_list->next) { |
| 608 | /* we might have raced another instance of this function */ |
| 609 | ret = radix_tree_insert(&bdi->cgwb_tree, memcg_css->id, wb); |
| 610 | if (!ret) { |
Tejun Heo | b817525 | 2015-10-02 14:47:05 -0400 | [diff] [blame] | 611 | list_add_tail_rcu(&wb->bdi_node, &bdi->wb_list); |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 612 | list_add(&wb->memcg_node, memcg_cgwb_list); |
| 613 | list_add(&wb->blkcg_node, blkcg_cgwb_list); |
| 614 | css_get(memcg_css); |
| 615 | css_get(blkcg_css); |
| 616 | } |
| 617 | } |
| 618 | spin_unlock_irqrestore(&cgwb_lock, flags); |
| 619 | if (ret) { |
| 620 | if (ret == -EEXIST) |
| 621 | ret = 0; |
Tejun Heo | a13f35e | 2015-07-02 08:44:34 -0600 | [diff] [blame] | 622 | goto err_fprop_exit; |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 623 | } |
| 624 | goto out_put; |
| 625 | |
Tejun Heo | 841710a | 2015-05-22 18:23:33 -0400 | [diff] [blame] | 626 | err_fprop_exit: |
| 627 | fprop_local_destroy_percpu(&wb->memcg_completions); |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 628 | err_ref_exit: |
| 629 | percpu_ref_exit(&wb->refcnt); |
| 630 | err_wb_exit: |
| 631 | wb_exit(wb); |
| 632 | err_free: |
| 633 | kfree(wb); |
| 634 | out_put: |
| 635 | css_put(blkcg_css); |
| 636 | return ret; |
| 637 | } |
| 638 | |
| 639 | /** |
| 640 | * wb_get_create - get wb for a given memcg, create if necessary |
| 641 | * @bdi: target bdi |
| 642 | * @memcg_css: cgroup_subsys_state of the target memcg (must have positive ref) |
| 643 | * @gfp: allocation mask to use |
| 644 | * |
| 645 | * Try to get the wb for @memcg_css on @bdi. If it doesn't exist, try to |
| 646 | * create one. The returned wb has its refcount incremented. |
| 647 | * |
| 648 | * This function uses css_get() on @memcg_css and thus expects its refcnt |
| 649 | * to be positive on invocation. IOW, rcu_read_lock() protection on |
| 650 | * @memcg_css isn't enough. try_get it before calling this function. |
| 651 | * |
| 652 | * A wb is keyed by its associated memcg. As blkcg implicitly enables |
| 653 | * memcg on the default hierarchy, memcg association is guaranteed to be |
| 654 | * more specific (equal or descendant to the associated blkcg) and thus can |
| 655 | * identify both the memcg and blkcg associations. |
| 656 | * |
| 657 | * Because the blkcg associated with a memcg may change as blkcg is enabled |
| 658 | * and disabled closer to root in the hierarchy, each wb keeps track of |
| 659 | * both the memcg and blkcg associated with it and verifies the blkcg on |
| 660 | * each lookup. On mismatch, the existing wb is discarded and a new one is |
| 661 | * created. |
| 662 | */ |
| 663 | struct bdi_writeback *wb_get_create(struct backing_dev_info *bdi, |
| 664 | struct cgroup_subsys_state *memcg_css, |
| 665 | gfp_t gfp) |
| 666 | { |
| 667 | struct bdi_writeback *wb; |
| 668 | |
Mel Gorman | d0164ad | 2015-11-06 16:28:21 -0800 | [diff] [blame] | 669 | might_sleep_if(gfpflags_allow_blocking(gfp)); |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 670 | |
| 671 | if (!memcg_css->parent) |
| 672 | return &bdi->wb; |
| 673 | |
| 674 | do { |
| 675 | rcu_read_lock(); |
| 676 | wb = radix_tree_lookup(&bdi->cgwb_tree, memcg_css->id); |
| 677 | if (wb) { |
| 678 | struct cgroup_subsys_state *blkcg_css; |
| 679 | |
| 680 | /* see whether the blkcg association has changed */ |
| 681 | blkcg_css = cgroup_get_e_css(memcg_css->cgroup, |
Tejun Heo | c165b3e | 2015-08-18 14:55:29 -0700 | [diff] [blame] | 682 | &io_cgrp_subsys); |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 683 | if (unlikely(wb->blkcg_css != blkcg_css || |
| 684 | !wb_tryget(wb))) |
| 685 | wb = NULL; |
| 686 | css_put(blkcg_css); |
| 687 | } |
| 688 | rcu_read_unlock(); |
| 689 | } while (!wb && !cgwb_create(bdi, memcg_css, gfp)); |
| 690 | |
| 691 | return wb; |
| 692 | } |
| 693 | |
Tejun Heo | a13f35e | 2015-07-02 08:44:34 -0600 | [diff] [blame] | 694 | static int cgwb_bdi_init(struct backing_dev_info *bdi) |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 695 | { |
Tejun Heo | a13f35e | 2015-07-02 08:44:34 -0600 | [diff] [blame] | 696 | int ret; |
| 697 | |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 698 | INIT_RADIX_TREE(&bdi->cgwb_tree, GFP_ATOMIC); |
| 699 | bdi->cgwb_congested_tree = RB_ROOT; |
Tejun Heo | a13f35e | 2015-07-02 08:44:34 -0600 | [diff] [blame] | 700 | |
| 701 | ret = wb_init(&bdi->wb, bdi, 1, GFP_KERNEL); |
| 702 | if (!ret) { |
Johannes Weiner | 7d82860 | 2016-01-14 15:20:56 -0800 | [diff] [blame] | 703 | bdi->wb.memcg_css = &root_mem_cgroup->css; |
Tejun Heo | a13f35e | 2015-07-02 08:44:34 -0600 | [diff] [blame] | 704 | bdi->wb.blkcg_css = blkcg_root_css; |
| 705 | } |
| 706 | return ret; |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 707 | } |
| 708 | |
Jan Kara | b1c51af | 2017-03-23 01:36:59 +0100 | [diff] [blame] | 709 | static void cgwb_bdi_unregister(struct backing_dev_info *bdi) |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 710 | { |
| 711 | struct radix_tree_iter iter; |
| 712 | void **slot; |
Jan Kara | 5318ce7 | 2017-03-23 01:36:57 +0100 | [diff] [blame] | 713 | struct bdi_writeback *wb; |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 714 | |
| 715 | WARN_ON(test_bit(WB_registered, &bdi->wb.state)); |
| 716 | |
| 717 | spin_lock_irq(&cgwb_lock); |
| 718 | radix_tree_for_each_slot(slot, &bdi->cgwb_tree, &iter, 0) |
| 719 | cgwb_kill(*slot); |
Jan Kara | 5318ce7 | 2017-03-23 01:36:57 +0100 | [diff] [blame] | 720 | |
| 721 | while (!list_empty(&bdi->wb_list)) { |
| 722 | wb = list_first_entry(&bdi->wb_list, struct bdi_writeback, |
| 723 | bdi_node); |
| 724 | spin_unlock_irq(&cgwb_lock); |
| 725 | wb_shutdown(wb); |
| 726 | spin_lock_irq(&cgwb_lock); |
| 727 | } |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 728 | spin_unlock_irq(&cgwb_lock); |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 729 | } |
| 730 | |
| 731 | /** |
| 732 | * wb_memcg_offline - kill all wb's associated with a memcg being offlined |
| 733 | * @memcg: memcg being offlined |
| 734 | * |
| 735 | * Also prevents creation of any new wb's associated with @memcg. |
| 736 | */ |
| 737 | void wb_memcg_offline(struct mem_cgroup *memcg) |
| 738 | { |
Wang Long | 9ccc361 | 2018-06-07 17:07:19 -0700 | [diff] [blame^] | 739 | struct list_head *memcg_cgwb_list = &memcg->cgwb_list; |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 740 | struct bdi_writeback *wb, *next; |
| 741 | |
| 742 | spin_lock_irq(&cgwb_lock); |
| 743 | list_for_each_entry_safe(wb, next, memcg_cgwb_list, memcg_node) |
| 744 | cgwb_kill(wb); |
| 745 | memcg_cgwb_list->next = NULL; /* prevent new wb's */ |
| 746 | spin_unlock_irq(&cgwb_lock); |
| 747 | } |
| 748 | |
| 749 | /** |
| 750 | * wb_blkcg_offline - kill all wb's associated with a blkcg being offlined |
| 751 | * @blkcg: blkcg being offlined |
| 752 | * |
| 753 | * Also prevents creation of any new wb's associated with @blkcg. |
| 754 | */ |
| 755 | void wb_blkcg_offline(struct blkcg *blkcg) |
| 756 | { |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 757 | struct bdi_writeback *wb, *next; |
| 758 | |
| 759 | spin_lock_irq(&cgwb_lock); |
| 760 | list_for_each_entry_safe(wb, next, &blkcg->cgwb_list, blkcg_node) |
| 761 | cgwb_kill(wb); |
| 762 | blkcg->cgwb_list.next = NULL; /* prevent new wb's */ |
| 763 | spin_unlock_irq(&cgwb_lock); |
| 764 | } |
| 765 | |
Jan Kara | df23de5 | 2017-03-08 17:48:32 +0100 | [diff] [blame] | 766 | static void cgwb_bdi_exit(struct backing_dev_info *bdi) |
| 767 | { |
| 768 | struct rb_node *rbn; |
| 769 | |
| 770 | spin_lock_irq(&cgwb_lock); |
| 771 | while ((rbn = rb_first(&bdi->cgwb_congested_tree))) { |
| 772 | struct bdi_writeback_congested *congested = |
| 773 | rb_entry(rbn, struct bdi_writeback_congested, rb_node); |
| 774 | |
| 775 | rb_erase(rbn, &bdi->cgwb_congested_tree); |
Jan Kara | b7d680d | 2017-03-23 01:36:54 +0100 | [diff] [blame] | 776 | congested->__bdi = NULL; /* mark @congested unlinked */ |
Jan Kara | df23de5 | 2017-03-08 17:48:32 +0100 | [diff] [blame] | 777 | } |
| 778 | spin_unlock_irq(&cgwb_lock); |
| 779 | } |
| 780 | |
Jan Kara | e8cb72b | 2017-03-23 01:36:56 +0100 | [diff] [blame] | 781 | static void cgwb_bdi_register(struct backing_dev_info *bdi) |
| 782 | { |
| 783 | spin_lock_irq(&cgwb_lock); |
| 784 | list_add_tail_rcu(&bdi->wb.bdi_node, &bdi->wb_list); |
| 785 | spin_unlock_irq(&cgwb_lock); |
| 786 | } |
| 787 | |
Tejun Heo | f183464 | 2018-05-23 10:56:32 -0700 | [diff] [blame] | 788 | static int __init cgwb_init(void) |
| 789 | { |
| 790 | /* |
| 791 | * There can be many concurrent release work items overwhelming |
| 792 | * system_wq. Put them in a separate wq and limit concurrency. |
| 793 | * There's no point in executing many of these in parallel. |
| 794 | */ |
| 795 | cgwb_release_wq = alloc_workqueue("cgwb_release", 0, 1); |
| 796 | if (!cgwb_release_wq) |
| 797 | return -ENOMEM; |
| 798 | |
| 799 | return 0; |
| 800 | } |
| 801 | subsys_initcall(cgwb_init); |
| 802 | |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 803 | #else /* CONFIG_CGROUP_WRITEBACK */ |
| 804 | |
Tejun Heo | a13f35e | 2015-07-02 08:44:34 -0600 | [diff] [blame] | 805 | static int cgwb_bdi_init(struct backing_dev_info *bdi) |
| 806 | { |
| 807 | int err; |
| 808 | |
| 809 | bdi->wb_congested = kzalloc(sizeof(*bdi->wb_congested), GFP_KERNEL); |
| 810 | if (!bdi->wb_congested) |
| 811 | return -ENOMEM; |
| 812 | |
Tejun Heo | 5f478e4 | 2017-02-08 15:19:07 -0500 | [diff] [blame] | 813 | atomic_set(&bdi->wb_congested->refcnt, 1); |
| 814 | |
Tejun Heo | a13f35e | 2015-07-02 08:44:34 -0600 | [diff] [blame] | 815 | err = wb_init(&bdi->wb, bdi, 1, GFP_KERNEL); |
| 816 | if (err) { |
Tejun Heo | 5f478e4 | 2017-02-08 15:19:07 -0500 | [diff] [blame] | 817 | wb_congested_put(bdi->wb_congested); |
Tejun Heo | a13f35e | 2015-07-02 08:44:34 -0600 | [diff] [blame] | 818 | return err; |
| 819 | } |
| 820 | return 0; |
| 821 | } |
| 822 | |
Jan Kara | b1c51af | 2017-03-23 01:36:59 +0100 | [diff] [blame] | 823 | static void cgwb_bdi_unregister(struct backing_dev_info *bdi) { } |
Jan Kara | df23de5 | 2017-03-08 17:48:32 +0100 | [diff] [blame] | 824 | |
| 825 | static void cgwb_bdi_exit(struct backing_dev_info *bdi) |
Tejun Heo | 5f478e4 | 2017-02-08 15:19:07 -0500 | [diff] [blame] | 826 | { |
| 827 | wb_congested_put(bdi->wb_congested); |
| 828 | } |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 829 | |
Jan Kara | e8cb72b | 2017-03-23 01:36:56 +0100 | [diff] [blame] | 830 | static void cgwb_bdi_register(struct backing_dev_info *bdi) |
| 831 | { |
| 832 | list_add_tail_rcu(&bdi->wb.bdi_node, &bdi->wb_list); |
| 833 | } |
| 834 | |
| 835 | static void cgwb_remove_from_bdi_list(struct bdi_writeback *wb) |
| 836 | { |
| 837 | list_del_rcu(&wb->bdi_node); |
| 838 | } |
| 839 | |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 840 | #endif /* CONFIG_CGROUP_WRITEBACK */ |
| 841 | |
Jan Kara | 2e82b84 | 2017-04-12 12:24:48 +0200 | [diff] [blame] | 842 | static int bdi_init(struct backing_dev_info *bdi) |
Peter Zijlstra | b2e8fb6 | 2007-10-16 23:25:47 -0700 | [diff] [blame] | 843 | { |
Tejun Heo | b817525 | 2015-10-02 14:47:05 -0400 | [diff] [blame] | 844 | int ret; |
| 845 | |
Peter Zijlstra | cf0ca9f | 2008-04-30 00:54:32 -0700 | [diff] [blame] | 846 | bdi->dev = NULL; |
| 847 | |
Jan Kara | d03f6cd | 2017-02-02 15:56:51 +0100 | [diff] [blame] | 848 | kref_init(&bdi->refcnt); |
Peter Zijlstra | 189d3c4 | 2008-04-30 00:54:35 -0700 | [diff] [blame] | 849 | bdi->min_ratio = 0; |
Peter Zijlstra | a42dde0 | 2008-04-30 00:54:36 -0700 | [diff] [blame] | 850 | bdi->max_ratio = 100; |
Jan Kara | eb608e3 | 2012-05-24 18:59:11 +0200 | [diff] [blame] | 851 | bdi->max_prop_frac = FPROP_FRAC_BASE; |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 852 | INIT_LIST_HEAD(&bdi->bdi_list); |
Tejun Heo | b817525 | 2015-10-02 14:47:05 -0400 | [diff] [blame] | 853 | INIT_LIST_HEAD(&bdi->wb_list); |
Tejun Heo | cc395d7 | 2015-05-22 17:13:58 -0400 | [diff] [blame] | 854 | init_waitqueue_head(&bdi->wb_waitq); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 855 | |
Tejun Heo | b817525 | 2015-10-02 14:47:05 -0400 | [diff] [blame] | 856 | ret = cgwb_bdi_init(bdi); |
| 857 | |
Tejun Heo | b817525 | 2015-10-02 14:47:05 -0400 | [diff] [blame] | 858 | return ret; |
Peter Zijlstra | b2e8fb6 | 2007-10-16 23:25:47 -0700 | [diff] [blame] | 859 | } |
Peter Zijlstra | b2e8fb6 | 2007-10-16 23:25:47 -0700 | [diff] [blame] | 860 | |
Jan Kara | d03f6cd | 2017-02-02 15:56:51 +0100 | [diff] [blame] | 861 | struct backing_dev_info *bdi_alloc_node(gfp_t gfp_mask, int node_id) |
| 862 | { |
| 863 | struct backing_dev_info *bdi; |
| 864 | |
| 865 | bdi = kmalloc_node(sizeof(struct backing_dev_info), |
| 866 | gfp_mask | __GFP_ZERO, node_id); |
| 867 | if (!bdi) |
| 868 | return NULL; |
| 869 | |
| 870 | if (bdi_init(bdi)) { |
| 871 | kfree(bdi); |
| 872 | return NULL; |
| 873 | } |
| 874 | return bdi; |
| 875 | } |
Jan Kara | 62bf42a | 2017-04-12 12:24:27 +0200 | [diff] [blame] | 876 | EXPORT_SYMBOL(bdi_alloc_node); |
Jan Kara | d03f6cd | 2017-02-02 15:56:51 +0100 | [diff] [blame] | 877 | |
Jan Kara | 7c4cc30 | 2017-04-12 12:24:49 +0200 | [diff] [blame] | 878 | int bdi_register_va(struct backing_dev_info *bdi, const char *fmt, va_list args) |
Peter Zijlstra | b2e8fb6 | 2007-10-16 23:25:47 -0700 | [diff] [blame] | 879 | { |
Peter Zijlstra | b2e8fb6 | 2007-10-16 23:25:47 -0700 | [diff] [blame] | 880 | struct device *dev; |
| 881 | |
| 882 | if (bdi->dev) /* The driver needs to use separate queues per device */ |
| 883 | return 0; |
| 884 | |
Jan Kara | 7c4cc30 | 2017-04-12 12:24:49 +0200 | [diff] [blame] | 885 | dev = device_create_vargs(bdi_class, NULL, MKDEV(0, 0), bdi, fmt, args); |
Peter Zijlstra | b2e8fb6 | 2007-10-16 23:25:47 -0700 | [diff] [blame] | 886 | if (IS_ERR(dev)) |
| 887 | return PTR_ERR(dev); |
| 888 | |
Jan Kara | e8cb72b | 2017-03-23 01:36:56 +0100 | [diff] [blame] | 889 | cgwb_bdi_register(bdi); |
Peter Zijlstra | b2e8fb6 | 2007-10-16 23:25:47 -0700 | [diff] [blame] | 890 | bdi->dev = dev; |
| 891 | |
Jens Axboe | 6d0e482 | 2017-12-21 10:01:30 -0700 | [diff] [blame] | 892 | bdi_debug_register(bdi, dev_name(dev)); |
Tejun Heo | 4610007 | 2015-05-22 17:13:31 -0400 | [diff] [blame] | 893 | set_bit(WB_registered, &bdi->wb.state); |
Peter Zijlstra | b2e8fb6 | 2007-10-16 23:25:47 -0700 | [diff] [blame] | 894 | |
| 895 | spin_lock_bh(&bdi_lock); |
| 896 | list_add_tail_rcu(&bdi->bdi_list, &bdi_list); |
| 897 | spin_unlock_bh(&bdi_lock); |
| 898 | |
| 899 | trace_writeback_bdi_register(bdi); |
| 900 | return 0; |
| 901 | } |
Jan Kara | baf7a61 | 2017-04-12 12:24:25 +0200 | [diff] [blame] | 902 | EXPORT_SYMBOL(bdi_register_va); |
| 903 | |
Jan Kara | 7c4cc30 | 2017-04-12 12:24:49 +0200 | [diff] [blame] | 904 | int bdi_register(struct backing_dev_info *bdi, const char *fmt, ...) |
Jan Kara | baf7a61 | 2017-04-12 12:24:25 +0200 | [diff] [blame] | 905 | { |
| 906 | va_list args; |
| 907 | int ret; |
| 908 | |
| 909 | va_start(args, fmt); |
Jan Kara | 7c4cc30 | 2017-04-12 12:24:49 +0200 | [diff] [blame] | 910 | ret = bdi_register_va(bdi, fmt, args); |
Jan Kara | baf7a61 | 2017-04-12 12:24:25 +0200 | [diff] [blame] | 911 | va_end(args); |
| 912 | return ret; |
| 913 | } |
Peter Zijlstra | b2e8fb6 | 2007-10-16 23:25:47 -0700 | [diff] [blame] | 914 | EXPORT_SYMBOL(bdi_register); |
| 915 | |
Dan Williams | df08c32 | 2016-07-31 11:15:13 -0700 | [diff] [blame] | 916 | int bdi_register_owner(struct backing_dev_info *bdi, struct device *owner) |
| 917 | { |
| 918 | int rc; |
| 919 | |
Jan Kara | 7c4cc30 | 2017-04-12 12:24:49 +0200 | [diff] [blame] | 920 | rc = bdi_register(bdi, "%u:%u", MAJOR(owner->devt), MINOR(owner->devt)); |
Dan Williams | df08c32 | 2016-07-31 11:15:13 -0700 | [diff] [blame] | 921 | if (rc) |
| 922 | return rc; |
Jan Kara | b6f8fec | 2017-03-08 17:48:31 +0100 | [diff] [blame] | 923 | /* Leaking owner reference... */ |
| 924 | WARN_ON(bdi->owner); |
Dan Williams | df08c32 | 2016-07-31 11:15:13 -0700 | [diff] [blame] | 925 | bdi->owner = owner; |
| 926 | get_device(owner); |
| 927 | return 0; |
| 928 | } |
| 929 | EXPORT_SYMBOL(bdi_register_owner); |
| 930 | |
Peter Zijlstra | b2e8fb6 | 2007-10-16 23:25:47 -0700 | [diff] [blame] | 931 | /* |
Tejun Heo | 4610007 | 2015-05-22 17:13:31 -0400 | [diff] [blame] | 932 | * Remove bdi from bdi_list, and ensure that it is no longer visible |
Peter Zijlstra | b2e8fb6 | 2007-10-16 23:25:47 -0700 | [diff] [blame] | 933 | */ |
Tejun Heo | 4610007 | 2015-05-22 17:13:31 -0400 | [diff] [blame] | 934 | static void bdi_remove_from_list(struct backing_dev_info *bdi) |
Peter Zijlstra | 04fbfdc | 2007-10-16 23:25:50 -0700 | [diff] [blame] | 935 | { |
Tejun Heo | 4610007 | 2015-05-22 17:13:31 -0400 | [diff] [blame] | 936 | spin_lock_bh(&bdi_lock); |
| 937 | list_del_rcu(&bdi->bdi_list); |
| 938 | spin_unlock_bh(&bdi_lock); |
Andrew Morton | 3fcfab1 | 2006-10-19 23:28:16 -0700 | [diff] [blame] | 939 | |
Tejun Heo | 4610007 | 2015-05-22 17:13:31 -0400 | [diff] [blame] | 940 | synchronize_rcu_expedited(); |
Andrew Morton | 3fcfab1 | 2006-10-19 23:28:16 -0700 | [diff] [blame] | 941 | } |
| 942 | |
Tejun Heo | b02176f | 2015-09-08 12:20:22 -0400 | [diff] [blame] | 943 | void bdi_unregister(struct backing_dev_info *bdi) |
Andrew Morton | 3fcfab1 | 2006-10-19 23:28:16 -0700 | [diff] [blame] | 944 | { |
Tejun Heo | f0054bb | 2015-05-22 17:13:30 -0400 | [diff] [blame] | 945 | /* make sure nobody finds us on the bdi_list anymore */ |
| 946 | bdi_remove_from_list(bdi); |
| 947 | wb_shutdown(&bdi->wb); |
Jan Kara | b1c51af | 2017-03-23 01:36:59 +0100 | [diff] [blame] | 948 | cgwb_bdi_unregister(bdi); |
Rabin Vincent | 7a401a9 | 2011-11-11 13:29:04 +0100 | [diff] [blame] | 949 | |
Christoph Hellwig | c4db59d | 2015-01-20 14:05:00 -0700 | [diff] [blame] | 950 | if (bdi->dev) { |
| 951 | bdi_debug_unregister(bdi); |
| 952 | device_unregister(bdi->dev); |
| 953 | bdi->dev = NULL; |
| 954 | } |
Dan Williams | df08c32 | 2016-07-31 11:15:13 -0700 | [diff] [blame] | 955 | |
| 956 | if (bdi->owner) { |
| 957 | put_device(bdi->owner); |
| 958 | bdi->owner = NULL; |
| 959 | } |
Tejun Heo | b02176f | 2015-09-08 12:20:22 -0400 | [diff] [blame] | 960 | } |
Christoph Hellwig | c4db59d | 2015-01-20 14:05:00 -0700 | [diff] [blame] | 961 | |
Jan Kara | d03f6cd | 2017-02-02 15:56:51 +0100 | [diff] [blame] | 962 | static void release_bdi(struct kref *ref) |
| 963 | { |
| 964 | struct backing_dev_info *bdi = |
| 965 | container_of(ref, struct backing_dev_info, refcnt); |
| 966 | |
Jan Kara | 5af110b | 2017-04-12 12:24:26 +0200 | [diff] [blame] | 967 | if (test_bit(WB_registered, &bdi->wb.state)) |
| 968 | bdi_unregister(bdi); |
Jan Kara | 2e82b84 | 2017-04-12 12:24:48 +0200 | [diff] [blame] | 969 | WARN_ON_ONCE(bdi->dev); |
| 970 | wb_exit(&bdi->wb); |
| 971 | cgwb_bdi_exit(bdi); |
Jan Kara | d03f6cd | 2017-02-02 15:56:51 +0100 | [diff] [blame] | 972 | kfree(bdi); |
| 973 | } |
| 974 | |
| 975 | void bdi_put(struct backing_dev_info *bdi) |
| 976 | { |
| 977 | kref_put(&bdi->refcnt, release_bdi); |
| 978 | } |
Jan Kara | 62bf42a | 2017-04-12 12:24:27 +0200 | [diff] [blame] | 979 | EXPORT_SYMBOL(bdi_put); |
Jan Kara | d03f6cd | 2017-02-02 15:56:51 +0100 | [diff] [blame] | 980 | |
Andrew Morton | 3fcfab1 | 2006-10-19 23:28:16 -0700 | [diff] [blame] | 981 | static wait_queue_head_t congestion_wqh[2] = { |
| 982 | __WAIT_QUEUE_HEAD_INITIALIZER(congestion_wqh[0]), |
| 983 | __WAIT_QUEUE_HEAD_INITIALIZER(congestion_wqh[1]) |
| 984 | }; |
Tejun Heo | ec8a6f2 | 2015-05-22 17:13:41 -0400 | [diff] [blame] | 985 | static atomic_t nr_wb_congested[2]; |
Andrew Morton | 3fcfab1 | 2006-10-19 23:28:16 -0700 | [diff] [blame] | 986 | |
Tejun Heo | ec8a6f2 | 2015-05-22 17:13:41 -0400 | [diff] [blame] | 987 | void clear_wb_congested(struct bdi_writeback_congested *congested, int sync) |
Andrew Morton | 3fcfab1 | 2006-10-19 23:28:16 -0700 | [diff] [blame] | 988 | { |
Jens Axboe | 1faa16d | 2009-04-06 14:48:01 +0200 | [diff] [blame] | 989 | wait_queue_head_t *wqh = &congestion_wqh[sync]; |
Kaixu Xia | c877ef8 | 2016-03-31 13:19:41 +0000 | [diff] [blame] | 990 | enum wb_congested_state bit; |
Andrew Morton | 3fcfab1 | 2006-10-19 23:28:16 -0700 | [diff] [blame] | 991 | |
Tejun Heo | 4452226 | 2015-05-22 17:13:26 -0400 | [diff] [blame] | 992 | bit = sync ? WB_sync_congested : WB_async_congested; |
Tejun Heo | ec8a6f2 | 2015-05-22 17:13:41 -0400 | [diff] [blame] | 993 | if (test_and_clear_bit(bit, &congested->state)) |
| 994 | atomic_dec(&nr_wb_congested[sync]); |
Peter Zijlstra | 4e857c5 | 2014-03-17 18:06:10 +0100 | [diff] [blame] | 995 | smp_mb__after_atomic(); |
Andrew Morton | 3fcfab1 | 2006-10-19 23:28:16 -0700 | [diff] [blame] | 996 | if (waitqueue_active(wqh)) |
| 997 | wake_up(wqh); |
| 998 | } |
Tejun Heo | ec8a6f2 | 2015-05-22 17:13:41 -0400 | [diff] [blame] | 999 | EXPORT_SYMBOL(clear_wb_congested); |
Andrew Morton | 3fcfab1 | 2006-10-19 23:28:16 -0700 | [diff] [blame] | 1000 | |
Tejun Heo | ec8a6f2 | 2015-05-22 17:13:41 -0400 | [diff] [blame] | 1001 | void set_wb_congested(struct bdi_writeback_congested *congested, int sync) |
Andrew Morton | 3fcfab1 | 2006-10-19 23:28:16 -0700 | [diff] [blame] | 1002 | { |
Kaixu Xia | c877ef8 | 2016-03-31 13:19:41 +0000 | [diff] [blame] | 1003 | enum wb_congested_state bit; |
Andrew Morton | 3fcfab1 | 2006-10-19 23:28:16 -0700 | [diff] [blame] | 1004 | |
Tejun Heo | 4452226 | 2015-05-22 17:13:26 -0400 | [diff] [blame] | 1005 | bit = sync ? WB_sync_congested : WB_async_congested; |
Tejun Heo | ec8a6f2 | 2015-05-22 17:13:41 -0400 | [diff] [blame] | 1006 | if (!test_and_set_bit(bit, &congested->state)) |
| 1007 | atomic_inc(&nr_wb_congested[sync]); |
Andrew Morton | 3fcfab1 | 2006-10-19 23:28:16 -0700 | [diff] [blame] | 1008 | } |
Tejun Heo | ec8a6f2 | 2015-05-22 17:13:41 -0400 | [diff] [blame] | 1009 | EXPORT_SYMBOL(set_wb_congested); |
Andrew Morton | 3fcfab1 | 2006-10-19 23:28:16 -0700 | [diff] [blame] | 1010 | |
| 1011 | /** |
| 1012 | * congestion_wait - wait for a backing_dev to become uncongested |
Jens Axboe | 8aa7e84 | 2009-07-09 14:52:32 +0200 | [diff] [blame] | 1013 | * @sync: SYNC or ASYNC IO |
Andrew Morton | 3fcfab1 | 2006-10-19 23:28:16 -0700 | [diff] [blame] | 1014 | * @timeout: timeout in jiffies |
| 1015 | * |
| 1016 | * Waits for up to @timeout jiffies for a backing_dev (any backing_dev) to exit |
| 1017 | * write congestion. If no backing_devs are congested then just wait for the |
| 1018 | * next write to be completed. |
| 1019 | */ |
Jens Axboe | 8aa7e84 | 2009-07-09 14:52:32 +0200 | [diff] [blame] | 1020 | long congestion_wait(int sync, long timeout) |
Andrew Morton | 3fcfab1 | 2006-10-19 23:28:16 -0700 | [diff] [blame] | 1021 | { |
| 1022 | long ret; |
Mel Gorman | 52bb919 | 2010-10-26 14:21:41 -0700 | [diff] [blame] | 1023 | unsigned long start = jiffies; |
Andrew Morton | 3fcfab1 | 2006-10-19 23:28:16 -0700 | [diff] [blame] | 1024 | DEFINE_WAIT(wait); |
Jens Axboe | 8aa7e84 | 2009-07-09 14:52:32 +0200 | [diff] [blame] | 1025 | wait_queue_head_t *wqh = &congestion_wqh[sync]; |
Andrew Morton | 3fcfab1 | 2006-10-19 23:28:16 -0700 | [diff] [blame] | 1026 | |
| 1027 | prepare_to_wait(wqh, &wait, TASK_UNINTERRUPTIBLE); |
| 1028 | ret = io_schedule_timeout(timeout); |
| 1029 | finish_wait(wqh, &wait); |
Mel Gorman | 52bb919 | 2010-10-26 14:21:41 -0700 | [diff] [blame] | 1030 | |
| 1031 | trace_writeback_congestion_wait(jiffies_to_usecs(timeout), |
| 1032 | jiffies_to_usecs(jiffies - start)); |
| 1033 | |
Andrew Morton | 3fcfab1 | 2006-10-19 23:28:16 -0700 | [diff] [blame] | 1034 | return ret; |
| 1035 | } |
| 1036 | EXPORT_SYMBOL(congestion_wait); |
| 1037 | |
Mel Gorman | 0e093d99 | 2010-10-26 14:21:45 -0700 | [diff] [blame] | 1038 | /** |
Mel Gorman | 599d0c9 | 2016-07-28 15:45:31 -0700 | [diff] [blame] | 1039 | * wait_iff_congested - Conditionally wait for a backing_dev to become uncongested or a pgdat to complete writes |
Mel Gorman | 0e093d99 | 2010-10-26 14:21:45 -0700 | [diff] [blame] | 1040 | * @sync: SYNC or ASYNC IO |
| 1041 | * @timeout: timeout in jiffies |
| 1042 | * |
Andrey Ryabinin | e3c1ac5 | 2018-04-10 16:28:03 -0700 | [diff] [blame] | 1043 | * In the event of a congested backing_dev (any backing_dev) this waits |
| 1044 | * for up to @timeout jiffies for either a BDI to exit congestion of the |
| 1045 | * given @sync queue or a write to complete. |
Mel Gorman | 0e093d99 | 2010-10-26 14:21:45 -0700 | [diff] [blame] | 1046 | * |
| 1047 | * The return value is 0 if the sleep is for the full timeout. Otherwise, |
| 1048 | * it is the number of jiffies that were still remaining when the function |
| 1049 | * returned. return_value == timeout implies the function did not sleep. |
| 1050 | */ |
Andrey Ryabinin | e3c1ac5 | 2018-04-10 16:28:03 -0700 | [diff] [blame] | 1051 | long wait_iff_congested(int sync, long timeout) |
Mel Gorman | 0e093d99 | 2010-10-26 14:21:45 -0700 | [diff] [blame] | 1052 | { |
| 1053 | long ret; |
| 1054 | unsigned long start = jiffies; |
| 1055 | DEFINE_WAIT(wait); |
| 1056 | wait_queue_head_t *wqh = &congestion_wqh[sync]; |
| 1057 | |
| 1058 | /* |
Andrey Ryabinin | e3c1ac5 | 2018-04-10 16:28:03 -0700 | [diff] [blame] | 1059 | * If there is no congestion, yield if necessary instead |
Mel Gorman | 0e093d99 | 2010-10-26 14:21:45 -0700 | [diff] [blame] | 1060 | * of sleeping on the congestion queue |
| 1061 | */ |
Andrey Ryabinin | e3c1ac5 | 2018-04-10 16:28:03 -0700 | [diff] [blame] | 1062 | if (atomic_read(&nr_wb_congested[sync]) == 0) { |
Michal Hocko | ede3771 | 2016-05-20 16:57:03 -0700 | [diff] [blame] | 1063 | cond_resched(); |
Mel Gorman | 599d0c9 | 2016-07-28 15:45:31 -0700 | [diff] [blame] | 1064 | |
Mel Gorman | 0e093d99 | 2010-10-26 14:21:45 -0700 | [diff] [blame] | 1065 | /* In case we scheduled, work out time remaining */ |
| 1066 | ret = timeout - (jiffies - start); |
| 1067 | if (ret < 0) |
| 1068 | ret = 0; |
| 1069 | |
| 1070 | goto out; |
| 1071 | } |
| 1072 | |
| 1073 | /* Sleep until uncongested or a write happens */ |
| 1074 | prepare_to_wait(wqh, &wait, TASK_UNINTERRUPTIBLE); |
| 1075 | ret = io_schedule_timeout(timeout); |
| 1076 | finish_wait(wqh, &wait); |
| 1077 | |
| 1078 | out: |
| 1079 | trace_writeback_wait_iff_congested(jiffies_to_usecs(timeout), |
| 1080 | jiffies_to_usecs(jiffies - start)); |
| 1081 | |
| 1082 | return ret; |
| 1083 | } |
| 1084 | EXPORT_SYMBOL(wait_iff_congested); |