Thomas Gleixner | 457c899 | 2019-05-19 13:08:55 +0100 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0-only |
Andrew Morton | 3fcfab1 | 2006-10-19 23:28:16 -0700 | [diff] [blame] | 2 | |
Christoph Hellwig | c97ab27 | 2022-04-20 06:27:19 +0200 | [diff] [blame] | 3 | #include <linux/blkdev.h> |
Andrew Morton | 3fcfab1 | 2006-10-19 23:28:16 -0700 | [diff] [blame] | 4 | #include <linux/wait.h> |
Tejun Heo | 34f8fe5 | 2019-08-26 09:06:53 -0700 | [diff] [blame] | 5 | #include <linux/rbtree.h> |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 6 | #include <linux/kthread.h> |
Christoph Hellwig | e41d12f | 2021-09-20 14:33:13 +0200 | [diff] [blame] | 7 | #include <linux/backing-dev.h> |
| 8 | #include <linux/blk-cgroup.h> |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 9 | #include <linux/freezer.h> |
Andrew Morton | 3fcfab1 | 2006-10-19 23:28:16 -0700 | [diff] [blame] | 10 | #include <linux/fs.h> |
Jens Axboe | 2616015 | 2009-03-17 09:35:06 +0100 | [diff] [blame] | 11 | #include <linux/pagemap.h> |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 12 | #include <linux/mm.h> |
Daniel Vetter | c1ca59a | 2021-02-25 17:18:45 -0800 | [diff] [blame] | 13 | #include <linux/sched/mm.h> |
Andrew Morton | 3fcfab1 | 2006-10-19 23:28:16 -0700 | [diff] [blame] | 14 | #include <linux/sched.h> |
| 15 | #include <linux/module.h> |
Peter Zijlstra | cf0ca9f | 2008-04-30 00:54:32 -0700 | [diff] [blame] | 16 | #include <linux/writeback.h> |
| 17 | #include <linux/device.h> |
Dave Chinner | 455b286 | 2010-07-07 13:24:06 +1000 | [diff] [blame] | 18 | #include <trace/events/writeback.h> |
Peter Zijlstra | cf0ca9f | 2008-04-30 00:54:32 -0700 | [diff] [blame] | 19 | |
Christoph Hellwig | f56753a | 2020-09-24 08:51:40 +0200 | [diff] [blame] | 20 | struct backing_dev_info noop_backing_dev_info; |
Tejun Heo | a212b10 | 2015-05-22 17:13:33 -0400 | [diff] [blame] | 21 | EXPORT_SYMBOL_GPL(noop_backing_dev_info); |
Jörn Engel | 5129a46 | 2010-04-25 08:54:42 +0200 | [diff] [blame] | 22 | |
Peter Zijlstra | cf0ca9f | 2008-04-30 00:54:32 -0700 | [diff] [blame] | 23 | static struct class *bdi_class; |
Christoph Hellwig | eb7ae5e | 2020-05-04 14:47:54 +0200 | [diff] [blame] | 24 | static const char *bdi_unknown_name = "(unknown)"; |
Jens Axboe | cfc4ba5 | 2009-09-14 13:12:40 +0200 | [diff] [blame] | 25 | |
| 26 | /* |
Tejun Heo | 34f8fe5 | 2019-08-26 09:06:53 -0700 | [diff] [blame] | 27 | * bdi_lock protects bdi_tree and updates to bdi_list. bdi_list has RCU |
| 28 | * reader side locking. |
Jens Axboe | cfc4ba5 | 2009-09-14 13:12:40 +0200 | [diff] [blame] | 29 | */ |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 30 | DEFINE_SPINLOCK(bdi_lock); |
Tejun Heo | 34f8fe5 | 2019-08-26 09:06:53 -0700 | [diff] [blame] | 31 | static u64 bdi_id_cursor; |
| 32 | static struct rb_root bdi_tree = RB_ROOT; |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 33 | LIST_HEAD(bdi_list); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 34 | |
Tejun Heo | 839a8e8 | 2013-04-01 19:08:06 -0700 | [diff] [blame] | 35 | /* bdi_wq serves all asynchronous writeback tasks */ |
| 36 | struct workqueue_struct *bdi_wq; |
| 37 | |
Baolin Wang | 6986c3e | 2021-02-24 12:02:52 -0800 | [diff] [blame] | 38 | #define K(x) ((x) << (PAGE_SHIFT - 10)) |
| 39 | |
Miklos Szeredi | 76f1418 | 2008-04-30 00:54:36 -0700 | [diff] [blame] | 40 | #ifdef CONFIG_DEBUG_FS |
| 41 | #include <linux/debugfs.h> |
| 42 | #include <linux/seq_file.h> |
| 43 | |
| 44 | static struct dentry *bdi_debug_root; |
| 45 | |
| 46 | static void bdi_debug_init(void) |
| 47 | { |
| 48 | bdi_debug_root = debugfs_create_dir("bdi", NULL); |
| 49 | } |
| 50 | |
| 51 | static int bdi_debug_stats_show(struct seq_file *m, void *v) |
| 52 | { |
| 53 | struct backing_dev_info *bdi = m->private; |
Christoph Hellwig | c1955ce | 2010-06-19 23:08:06 +0200 | [diff] [blame] | 54 | struct bdi_writeback *wb = &bdi->wb; |
David Rientjes | 364aeb2 | 2009-01-06 14:39:29 -0800 | [diff] [blame] | 55 | unsigned long background_thresh; |
| 56 | unsigned long dirty_thresh; |
Tejun Heo | 0d960a3 | 2015-05-22 18:23:19 -0400 | [diff] [blame] | 57 | unsigned long wb_thresh; |
Theodore Ts'o | 0ae45f6 | 2015-02-02 00:37:00 -0500 | [diff] [blame] | 58 | unsigned long nr_dirty, nr_io, nr_more_io, nr_dirty_time; |
Jens Axboe | f09b00d | 2009-05-25 09:08:21 +0200 | [diff] [blame] | 59 | struct inode *inode; |
| 60 | |
Theodore Ts'o | 0ae45f6 | 2015-02-02 00:37:00 -0500 | [diff] [blame] | 61 | nr_dirty = nr_io = nr_more_io = nr_dirty_time = 0; |
Christoph Hellwig | f758eea | 2011-04-21 18:19:44 -0600 | [diff] [blame] | 62 | spin_lock(&wb->list_lock); |
Dave Chinner | c7f5408 | 2015-03-04 14:07:22 -0500 | [diff] [blame] | 63 | list_for_each_entry(inode, &wb->b_dirty, i_io_list) |
Christoph Hellwig | c1955ce | 2010-06-19 23:08:06 +0200 | [diff] [blame] | 64 | nr_dirty++; |
Dave Chinner | c7f5408 | 2015-03-04 14:07:22 -0500 | [diff] [blame] | 65 | list_for_each_entry(inode, &wb->b_io, i_io_list) |
Christoph Hellwig | c1955ce | 2010-06-19 23:08:06 +0200 | [diff] [blame] | 66 | nr_io++; |
Dave Chinner | c7f5408 | 2015-03-04 14:07:22 -0500 | [diff] [blame] | 67 | list_for_each_entry(inode, &wb->b_more_io, i_io_list) |
Christoph Hellwig | c1955ce | 2010-06-19 23:08:06 +0200 | [diff] [blame] | 68 | nr_more_io++; |
Dave Chinner | c7f5408 | 2015-03-04 14:07:22 -0500 | [diff] [blame] | 69 | 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] | 70 | if (inode->i_state & I_DIRTY_TIME) |
| 71 | nr_dirty_time++; |
Christoph Hellwig | f758eea | 2011-04-21 18:19:44 -0600 | [diff] [blame] | 72 | spin_unlock(&wb->list_lock); |
Miklos Szeredi | 76f1418 | 2008-04-30 00:54:36 -0700 | [diff] [blame] | 73 | |
Wu Fengguang | 16c4042 | 2010-08-11 14:17:39 -0700 | [diff] [blame] | 74 | global_dirty_limits(&background_thresh, &dirty_thresh); |
Tejun Heo | 0d960a3 | 2015-05-22 18:23:19 -0400 | [diff] [blame] | 75 | wb_thresh = wb_calc_thresh(wb, dirty_thresh); |
Miklos Szeredi | 76f1418 | 2008-04-30 00:54:36 -0700 | [diff] [blame] | 76 | |
Miklos Szeredi | 76f1418 | 2008-04-30 00:54:36 -0700 | [diff] [blame] | 77 | seq_printf(m, |
Wu Fengguang | 00821b0 | 2010-08-29 11:28:45 -0600 | [diff] [blame] | 78 | "BdiWriteback: %10lu kB\n" |
| 79 | "BdiReclaimable: %10lu kB\n" |
| 80 | "BdiDirtyThresh: %10lu kB\n" |
| 81 | "DirtyThresh: %10lu kB\n" |
| 82 | "BackgroundThresh: %10lu kB\n" |
Wu Fengguang | c8e28ce | 2011-01-23 10:07:47 -0600 | [diff] [blame] | 83 | "BdiDirtied: %10lu kB\n" |
Wu Fengguang | 00821b0 | 2010-08-29 11:28:45 -0600 | [diff] [blame] | 84 | "BdiWritten: %10lu kB\n" |
| 85 | "BdiWriteBandwidth: %10lu kBps\n" |
| 86 | "b_dirty: %10lu\n" |
| 87 | "b_io: %10lu\n" |
| 88 | "b_more_io: %10lu\n" |
Theodore Ts'o | 0ae45f6 | 2015-02-02 00:37:00 -0500 | [diff] [blame] | 89 | "b_dirty_time: %10lu\n" |
Wu Fengguang | 00821b0 | 2010-08-29 11:28:45 -0600 | [diff] [blame] | 90 | "bdi_list: %10u\n" |
| 91 | "state: %10lx\n", |
Tejun Heo | 93f78d8 | 2015-05-22 17:13:27 -0400 | [diff] [blame] | 92 | (unsigned long) K(wb_stat(wb, WB_WRITEBACK)), |
| 93 | (unsigned long) K(wb_stat(wb, WB_RECLAIMABLE)), |
Tejun Heo | 0d960a3 | 2015-05-22 18:23:19 -0400 | [diff] [blame] | 94 | K(wb_thresh), |
Jan Kara | f7d2b1e | 2010-12-08 22:44:24 -0600 | [diff] [blame] | 95 | K(dirty_thresh), |
| 96 | K(background_thresh), |
Tejun Heo | 93f78d8 | 2015-05-22 17:13:27 -0400 | [diff] [blame] | 97 | (unsigned long) K(wb_stat(wb, WB_DIRTIED)), |
| 98 | (unsigned long) K(wb_stat(wb, WB_WRITTEN)), |
Tejun Heo | a88a341 | 2015-05-22 17:13:28 -0400 | [diff] [blame] | 99 | (unsigned long) K(wb->write_bandwidth), |
Jan Kara | f7d2b1e | 2010-12-08 22:44:24 -0600 | [diff] [blame] | 100 | nr_dirty, |
| 101 | nr_io, |
| 102 | nr_more_io, |
Theodore Ts'o | 0ae45f6 | 2015-02-02 00:37:00 -0500 | [diff] [blame] | 103 | nr_dirty_time, |
Tejun Heo | 4452226 | 2015-05-22 17:13:26 -0400 | [diff] [blame] | 104 | !list_empty(&bdi->bdi_list), bdi->wb.state); |
Miklos Szeredi | 76f1418 | 2008-04-30 00:54:36 -0700 | [diff] [blame] | 105 | |
| 106 | return 0; |
| 107 | } |
Andy Shevchenko | 5ad3509 | 2018-04-05 16:23:16 -0700 | [diff] [blame] | 108 | DEFINE_SHOW_ATTRIBUTE(bdi_debug_stats); |
Miklos Szeredi | 76f1418 | 2008-04-30 00:54:36 -0700 | [diff] [blame] | 109 | |
Greg Kroah-Hartman | 2d146b9 | 2019-01-22 16:21:07 +0100 | [diff] [blame] | 110 | static void bdi_debug_register(struct backing_dev_info *bdi, const char *name) |
Miklos Szeredi | 76f1418 | 2008-04-30 00:54:36 -0700 | [diff] [blame] | 111 | { |
| 112 | bdi->debug_dir = debugfs_create_dir(name, bdi_debug_root); |
weiping zhang | 97f0769 | 2017-10-31 18:37:54 +0800 | [diff] [blame] | 113 | |
Greg Kroah-Hartman | 2d146b9 | 2019-01-22 16:21:07 +0100 | [diff] [blame] | 114 | debugfs_create_file("stats", 0444, bdi->debug_dir, bdi, |
| 115 | &bdi_debug_stats_fops); |
Miklos Szeredi | 76f1418 | 2008-04-30 00:54:36 -0700 | [diff] [blame] | 116 | } |
| 117 | |
| 118 | static void bdi_debug_unregister(struct backing_dev_info *bdi) |
| 119 | { |
Greg Kroah-Hartman | 2d146b9 | 2019-01-22 16:21:07 +0100 | [diff] [blame] | 120 | debugfs_remove_recursive(bdi->debug_dir); |
Miklos Szeredi | 76f1418 | 2008-04-30 00:54:36 -0700 | [diff] [blame] | 121 | } |
| 122 | #else |
| 123 | static inline void bdi_debug_init(void) |
| 124 | { |
| 125 | } |
Greg Kroah-Hartman | 2d146b9 | 2019-01-22 16:21:07 +0100 | [diff] [blame] | 126 | static inline void bdi_debug_register(struct backing_dev_info *bdi, |
Miklos Szeredi | 76f1418 | 2008-04-30 00:54:36 -0700 | [diff] [blame] | 127 | const char *name) |
| 128 | { |
| 129 | } |
| 130 | static inline void bdi_debug_unregister(struct backing_dev_info *bdi) |
| 131 | { |
| 132 | } |
| 133 | #endif |
| 134 | |
Peter Zijlstra | cf0ca9f | 2008-04-30 00:54:32 -0700 | [diff] [blame] | 135 | static ssize_t read_ahead_kb_store(struct device *dev, |
| 136 | struct device_attribute *attr, |
| 137 | const char *buf, size_t count) |
| 138 | { |
| 139 | struct backing_dev_info *bdi = dev_get_drvdata(dev); |
Peter Zijlstra | cf0ca9f | 2008-04-30 00:54:32 -0700 | [diff] [blame] | 140 | unsigned long read_ahead_kb; |
Namjae Jeon | 7034ed1 | 2012-08-25 16:57:27 +0800 | [diff] [blame] | 141 | ssize_t ret; |
Peter Zijlstra | cf0ca9f | 2008-04-30 00:54:32 -0700 | [diff] [blame] | 142 | |
Namjae Jeon | 7034ed1 | 2012-08-25 16:57:27 +0800 | [diff] [blame] | 143 | ret = kstrtoul(buf, 10, &read_ahead_kb); |
| 144 | if (ret < 0) |
| 145 | return ret; |
| 146 | |
| 147 | bdi->ra_pages = read_ahead_kb >> (PAGE_SHIFT - 10); |
| 148 | |
| 149 | return count; |
Peter Zijlstra | cf0ca9f | 2008-04-30 00:54:32 -0700 | [diff] [blame] | 150 | } |
| 151 | |
Peter Zijlstra | cf0ca9f | 2008-04-30 00:54:32 -0700 | [diff] [blame] | 152 | #define BDI_SHOW(name, expr) \ |
| 153 | static ssize_t name##_show(struct device *dev, \ |
Joe Perches | 5e4c0d8 | 2020-12-14 19:14:50 -0800 | [diff] [blame] | 154 | struct device_attribute *attr, char *buf) \ |
Peter Zijlstra | cf0ca9f | 2008-04-30 00:54:32 -0700 | [diff] [blame] | 155 | { \ |
| 156 | struct backing_dev_info *bdi = dev_get_drvdata(dev); \ |
| 157 | \ |
Joe Perches | 5e4c0d8 | 2020-12-14 19:14:50 -0800 | [diff] [blame] | 158 | return sysfs_emit(buf, "%lld\n", (long long)expr); \ |
Greg Kroah-Hartman | d9e1241 | 2013-07-24 15:05:26 -0700 | [diff] [blame] | 159 | } \ |
| 160 | static DEVICE_ATTR_RW(name); |
Peter Zijlstra | cf0ca9f | 2008-04-30 00:54:32 -0700 | [diff] [blame] | 161 | |
| 162 | BDI_SHOW(read_ahead_kb, K(bdi->ra_pages)) |
| 163 | |
Peter Zijlstra | 189d3c4 | 2008-04-30 00:54:35 -0700 | [diff] [blame] | 164 | static ssize_t min_ratio_store(struct device *dev, |
| 165 | struct device_attribute *attr, const char *buf, size_t count) |
| 166 | { |
| 167 | struct backing_dev_info *bdi = dev_get_drvdata(dev); |
Peter Zijlstra | 189d3c4 | 2008-04-30 00:54:35 -0700 | [diff] [blame] | 168 | unsigned int ratio; |
Namjae Jeon | 7034ed1 | 2012-08-25 16:57:27 +0800 | [diff] [blame] | 169 | ssize_t ret; |
Peter Zijlstra | 189d3c4 | 2008-04-30 00:54:35 -0700 | [diff] [blame] | 170 | |
Namjae Jeon | 7034ed1 | 2012-08-25 16:57:27 +0800 | [diff] [blame] | 171 | ret = kstrtouint(buf, 10, &ratio); |
| 172 | if (ret < 0) |
| 173 | return ret; |
| 174 | |
| 175 | ret = bdi_set_min_ratio(bdi, ratio); |
| 176 | if (!ret) |
| 177 | ret = count; |
| 178 | |
Peter Zijlstra | 189d3c4 | 2008-04-30 00:54:35 -0700 | [diff] [blame] | 179 | return ret; |
| 180 | } |
Stefan Roesch | ae82291 | 2022-11-18 16:51:59 -0800 | [diff] [blame] | 181 | BDI_SHOW(min_ratio, bdi->min_ratio / BDI_RATIO_SCALE) |
Peter Zijlstra | 189d3c4 | 2008-04-30 00:54:35 -0700 | [diff] [blame] | 182 | |
Stefan Roesch | ad3e6da | 2022-11-18 16:52:14 -0800 | [diff] [blame] | 183 | static ssize_t min_ratio_fine_store(struct device *dev, |
| 184 | struct device_attribute *attr, const char *buf, size_t count) |
| 185 | { |
| 186 | struct backing_dev_info *bdi = dev_get_drvdata(dev); |
| 187 | unsigned int ratio; |
| 188 | ssize_t ret; |
| 189 | |
| 190 | ret = kstrtouint(buf, 10, &ratio); |
| 191 | if (ret < 0) |
| 192 | return ret; |
| 193 | |
| 194 | ret = bdi_set_min_ratio_no_scale(bdi, ratio); |
| 195 | if (!ret) |
| 196 | ret = count; |
| 197 | |
| 198 | return ret; |
| 199 | } |
| 200 | BDI_SHOW(min_ratio_fine, bdi->min_ratio) |
| 201 | |
Peter Zijlstra | a42dde0 | 2008-04-30 00:54:36 -0700 | [diff] [blame] | 202 | static ssize_t max_ratio_store(struct device *dev, |
| 203 | struct device_attribute *attr, const char *buf, size_t count) |
| 204 | { |
| 205 | struct backing_dev_info *bdi = dev_get_drvdata(dev); |
Peter Zijlstra | a42dde0 | 2008-04-30 00:54:36 -0700 | [diff] [blame] | 206 | unsigned int ratio; |
Namjae Jeon | 7034ed1 | 2012-08-25 16:57:27 +0800 | [diff] [blame] | 207 | ssize_t ret; |
Peter Zijlstra | a42dde0 | 2008-04-30 00:54:36 -0700 | [diff] [blame] | 208 | |
Namjae Jeon | 7034ed1 | 2012-08-25 16:57:27 +0800 | [diff] [blame] | 209 | ret = kstrtouint(buf, 10, &ratio); |
| 210 | if (ret < 0) |
| 211 | return ret; |
| 212 | |
| 213 | ret = bdi_set_max_ratio(bdi, ratio); |
| 214 | if (!ret) |
| 215 | ret = count; |
| 216 | |
Peter Zijlstra | a42dde0 | 2008-04-30 00:54:36 -0700 | [diff] [blame] | 217 | return ret; |
| 218 | } |
Stefan Roesch | ae82291 | 2022-11-18 16:51:59 -0800 | [diff] [blame] | 219 | BDI_SHOW(max_ratio, bdi->max_ratio / BDI_RATIO_SCALE) |
Peter Zijlstra | a42dde0 | 2008-04-30 00:54:36 -0700 | [diff] [blame] | 220 | |
Stefan Roesch | bca52dc | 2022-11-18 16:52:11 -0800 | [diff] [blame] | 221 | static ssize_t max_ratio_fine_store(struct device *dev, |
| 222 | struct device_attribute *attr, const char *buf, size_t count) |
| 223 | { |
| 224 | struct backing_dev_info *bdi = dev_get_drvdata(dev); |
| 225 | unsigned int ratio; |
| 226 | ssize_t ret; |
| 227 | |
| 228 | ret = kstrtouint(buf, 10, &ratio); |
| 229 | if (ret < 0) |
| 230 | return ret; |
| 231 | |
| 232 | ret = bdi_set_max_ratio_no_scale(bdi, ratio); |
| 233 | if (!ret) |
| 234 | ret = count; |
| 235 | |
| 236 | return ret; |
| 237 | } |
| 238 | BDI_SHOW(max_ratio_fine, bdi->max_ratio) |
| 239 | |
Stefan Roesch | 9c84819 | 2022-11-18 16:52:08 -0800 | [diff] [blame] | 240 | static ssize_t min_bytes_show(struct device *dev, |
| 241 | struct device_attribute *attr, |
| 242 | char *buf) |
| 243 | { |
| 244 | struct backing_dev_info *bdi = dev_get_drvdata(dev); |
| 245 | |
| 246 | return sysfs_emit(buf, "%llu\n", bdi_get_min_bytes(bdi)); |
| 247 | } |
| 248 | |
| 249 | static ssize_t min_bytes_store(struct device *dev, |
| 250 | struct device_attribute *attr, const char *buf, size_t count) |
| 251 | { |
| 252 | struct backing_dev_info *bdi = dev_get_drvdata(dev); |
| 253 | u64 bytes; |
| 254 | ssize_t ret; |
| 255 | |
| 256 | ret = kstrtoull(buf, 10, &bytes); |
| 257 | if (ret < 0) |
| 258 | return ret; |
| 259 | |
| 260 | ret = bdi_set_min_bytes(bdi, bytes); |
| 261 | if (!ret) |
| 262 | ret = count; |
| 263 | |
| 264 | return ret; |
| 265 | } |
| 266 | DEVICE_ATTR_RW(min_bytes); |
| 267 | |
Stefan Roesch | c56e049 | 2022-11-18 16:52:03 -0800 | [diff] [blame] | 268 | static ssize_t max_bytes_show(struct device *dev, |
| 269 | struct device_attribute *attr, |
| 270 | char *buf) |
| 271 | { |
| 272 | struct backing_dev_info *bdi = dev_get_drvdata(dev); |
| 273 | |
| 274 | return sysfs_emit(buf, "%llu\n", bdi_get_max_bytes(bdi)); |
| 275 | } |
| 276 | |
| 277 | static ssize_t max_bytes_store(struct device *dev, |
| 278 | struct device_attribute *attr, const char *buf, size_t count) |
| 279 | { |
| 280 | struct backing_dev_info *bdi = dev_get_drvdata(dev); |
| 281 | u64 bytes; |
| 282 | ssize_t ret; |
| 283 | |
| 284 | ret = kstrtoull(buf, 10, &bytes); |
| 285 | if (ret < 0) |
| 286 | return ret; |
| 287 | |
| 288 | ret = bdi_set_max_bytes(bdi, bytes); |
| 289 | if (!ret) |
| 290 | ret = count; |
| 291 | |
| 292 | return ret; |
| 293 | } |
| 294 | DEVICE_ATTR_RW(max_bytes); |
| 295 | |
Darrick J. Wong | 7d311cd | 2013-02-21 16:42:48 -0800 | [diff] [blame] | 296 | static ssize_t stable_pages_required_show(struct device *dev, |
| 297 | struct device_attribute *attr, |
Joe Perches | 5e4c0d8 | 2020-12-14 19:14:50 -0800 | [diff] [blame] | 298 | char *buf) |
Darrick J. Wong | 7d311cd | 2013-02-21 16:42:48 -0800 | [diff] [blame] | 299 | { |
Christoph Hellwig | 1cb039f | 2020-09-24 08:51:38 +0200 | [diff] [blame] | 300 | dev_warn_once(dev, |
| 301 | "the stable_pages_required attribute has been removed. Use the stable_writes queue attribute instead.\n"); |
Joe Perches | 5e4c0d8 | 2020-12-14 19:14:50 -0800 | [diff] [blame] | 302 | return sysfs_emit(buf, "%d\n", 0); |
Darrick J. Wong | 7d311cd | 2013-02-21 16:42:48 -0800 | [diff] [blame] | 303 | } |
Greg Kroah-Hartman | d9e1241 | 2013-07-24 15:05:26 -0700 | [diff] [blame] | 304 | static DEVICE_ATTR_RO(stable_pages_required); |
Darrick J. Wong | 7d311cd | 2013-02-21 16:42:48 -0800 | [diff] [blame] | 305 | |
Stefan Roesch | 27bbe9d | 2022-11-18 16:51:57 -0800 | [diff] [blame] | 306 | static ssize_t strict_limit_store(struct device *dev, |
| 307 | struct device_attribute *attr, const char *buf, size_t count) |
| 308 | { |
| 309 | struct backing_dev_info *bdi = dev_get_drvdata(dev); |
| 310 | unsigned int strict_limit; |
| 311 | ssize_t ret; |
| 312 | |
| 313 | ret = kstrtouint(buf, 10, &strict_limit); |
| 314 | if (ret < 0) |
| 315 | return ret; |
| 316 | |
| 317 | ret = bdi_set_strict_limit(bdi, strict_limit); |
| 318 | if (!ret) |
| 319 | ret = count; |
| 320 | |
| 321 | return ret; |
| 322 | } |
| 323 | |
| 324 | static ssize_t strict_limit_show(struct device *dev, |
| 325 | struct device_attribute *attr, char *buf) |
| 326 | { |
| 327 | struct backing_dev_info *bdi = dev_get_drvdata(dev); |
| 328 | |
| 329 | return sysfs_emit(buf, "%d\n", |
| 330 | !!(bdi->capabilities & BDI_CAP_STRICTLIMIT)); |
| 331 | } |
| 332 | static DEVICE_ATTR_RW(strict_limit); |
| 333 | |
Greg Kroah-Hartman | d9e1241 | 2013-07-24 15:05:26 -0700 | [diff] [blame] | 334 | static struct attribute *bdi_dev_attrs[] = { |
| 335 | &dev_attr_read_ahead_kb.attr, |
| 336 | &dev_attr_min_ratio.attr, |
Stefan Roesch | ad3e6da | 2022-11-18 16:52:14 -0800 | [diff] [blame] | 337 | &dev_attr_min_ratio_fine.attr, |
Greg Kroah-Hartman | d9e1241 | 2013-07-24 15:05:26 -0700 | [diff] [blame] | 338 | &dev_attr_max_ratio.attr, |
Stefan Roesch | bca52dc | 2022-11-18 16:52:11 -0800 | [diff] [blame] | 339 | &dev_attr_max_ratio_fine.attr, |
Stefan Roesch | 9c84819 | 2022-11-18 16:52:08 -0800 | [diff] [blame] | 340 | &dev_attr_min_bytes.attr, |
Stefan Roesch | c56e049 | 2022-11-18 16:52:03 -0800 | [diff] [blame] | 341 | &dev_attr_max_bytes.attr, |
Greg Kroah-Hartman | d9e1241 | 2013-07-24 15:05:26 -0700 | [diff] [blame] | 342 | &dev_attr_stable_pages_required.attr, |
Stefan Roesch | 27bbe9d | 2022-11-18 16:51:57 -0800 | [diff] [blame] | 343 | &dev_attr_strict_limit.attr, |
Greg Kroah-Hartman | d9e1241 | 2013-07-24 15:05:26 -0700 | [diff] [blame] | 344 | NULL, |
Peter Zijlstra | cf0ca9f | 2008-04-30 00:54:32 -0700 | [diff] [blame] | 345 | }; |
Greg Kroah-Hartman | d9e1241 | 2013-07-24 15:05:26 -0700 | [diff] [blame] | 346 | ATTRIBUTE_GROUPS(bdi_dev); |
Peter Zijlstra | cf0ca9f | 2008-04-30 00:54:32 -0700 | [diff] [blame] | 347 | |
| 348 | static __init int bdi_class_init(void) |
| 349 | { |
| 350 | bdi_class = class_create(THIS_MODULE, "bdi"); |
Anton Blanchard | 1442145 | 2010-04-02 09:46:55 +0200 | [diff] [blame] | 351 | if (IS_ERR(bdi_class)) |
| 352 | return PTR_ERR(bdi_class); |
| 353 | |
Greg Kroah-Hartman | d9e1241 | 2013-07-24 15:05:26 -0700 | [diff] [blame] | 354 | bdi_class->dev_groups = bdi_dev_groups; |
Miklos Szeredi | 76f1418 | 2008-04-30 00:54:36 -0700 | [diff] [blame] | 355 | bdi_debug_init(); |
Jan Kara | d03f6cd | 2017-02-02 15:56:51 +0100 | [diff] [blame] | 356 | |
Peter Zijlstra | cf0ca9f | 2008-04-30 00:54:32 -0700 | [diff] [blame] | 357 | return 0; |
| 358 | } |
Miklos Szeredi | 76f1418 | 2008-04-30 00:54:36 -0700 | [diff] [blame] | 359 | postcore_initcall(bdi_class_init); |
Peter Zijlstra | cf0ca9f | 2008-04-30 00:54:32 -0700 | [diff] [blame] | 360 | |
Jens Axboe | 2616015 | 2009-03-17 09:35:06 +0100 | [diff] [blame] | 361 | static int __init default_bdi_init(void) |
| 362 | { |
Mika Westerberg | a2b90f1 | 2019-10-04 13:00:24 +0300 | [diff] [blame] | 363 | bdi_wq = alloc_workqueue("writeback", WQ_MEM_RECLAIM | WQ_UNBOUND | |
| 364 | WQ_SYSFS, 0); |
Tejun Heo | 839a8e8 | 2013-04-01 19:08:06 -0700 | [diff] [blame] | 365 | if (!bdi_wq) |
| 366 | return -ENOMEM; |
Jan Kara | 4bca7e8 | 2022-06-15 15:22:29 +0200 | [diff] [blame] | 367 | return 0; |
Jens Axboe | 2616015 | 2009-03-17 09:35:06 +0100 | [diff] [blame] | 368 | } |
| 369 | subsys_initcall(default_bdi_init); |
| 370 | |
Artem Bityutskiy | 6467716 | 2010-07-25 14:29:22 +0300 | [diff] [blame] | 371 | /* |
Tejun Heo | f0054bb | 2015-05-22 17:13:30 -0400 | [diff] [blame] | 372 | * 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] | 373 | * wakes-up the corresponding bdi thread which should then take care of the |
| 374 | * periodic background write-out of dirty inodes. Since the write-out would |
| 375 | * starts only 'dirty_writeback_interval' centisecs from now anyway, we just |
| 376 | * set up a timer which wakes the bdi thread up later. |
| 377 | * |
| 378 | * Note, we wouldn't bother setting up the timer, but this function is on the |
| 379 | * fast-path (used by '__mark_inode_dirty()'), so we save few context switches |
| 380 | * by delaying the wake-up. |
Derek Basehore | 6ca738d | 2014-04-03 14:46:22 -0700 | [diff] [blame] | 381 | * |
| 382 | * We have to be careful not to postpone flush work if it is scheduled for |
| 383 | * earlier. Thus we use queue_delayed_work(). |
Artem Bityutskiy | 6467716 | 2010-07-25 14:29:22 +0300 | [diff] [blame] | 384 | */ |
Tejun Heo | f0054bb | 2015-05-22 17:13:30 -0400 | [diff] [blame] | 385 | void wb_wakeup_delayed(struct bdi_writeback *wb) |
Artem Bityutskiy | 6467716 | 2010-07-25 14:29:22 +0300 | [diff] [blame] | 386 | { |
| 387 | unsigned long timeout; |
| 388 | |
| 389 | timeout = msecs_to_jiffies(dirty_writeback_interval * 10); |
Khazhismel Kumykov | f87904c | 2022-08-01 08:50:34 -0700 | [diff] [blame] | 390 | spin_lock_irq(&wb->work_lock); |
Tejun Heo | f0054bb | 2015-05-22 17:13:30 -0400 | [diff] [blame] | 391 | if (test_bit(WB_registered, &wb->state)) |
| 392 | queue_delayed_work(bdi_wq, &wb->dwork, timeout); |
Khazhismel Kumykov | f87904c | 2022-08-01 08:50:34 -0700 | [diff] [blame] | 393 | spin_unlock_irq(&wb->work_lock); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 394 | } |
| 395 | |
Jan Kara | 45a2966 | 2021-09-02 14:53:09 -0700 | [diff] [blame] | 396 | static void wb_update_bandwidth_workfn(struct work_struct *work) |
| 397 | { |
| 398 | struct bdi_writeback *wb = container_of(to_delayed_work(work), |
| 399 | struct bdi_writeback, bw_dwork); |
| 400 | |
| 401 | wb_update_bandwidth(wb); |
| 402 | } |
| 403 | |
Jens Axboe | cfc4ba5 | 2009-09-14 13:12:40 +0200 | [diff] [blame] | 404 | /* |
Tejun Heo | a88a341 | 2015-05-22 17:13:28 -0400 | [diff] [blame] | 405 | * Initial write bandwidth: 100 MB/s |
Jens Axboe | cfc4ba5 | 2009-09-14 13:12:40 +0200 | [diff] [blame] | 406 | */ |
Tejun Heo | a88a341 | 2015-05-22 17:13:28 -0400 | [diff] [blame] | 407 | #define INIT_BW (100 << (20 - PAGE_SHIFT)) |
Jens Axboe | cfc4ba5 | 2009-09-14 13:12:40 +0200 | [diff] [blame] | 408 | |
Tejun Heo | 8395cd9 | 2015-05-22 17:13:34 -0400 | [diff] [blame] | 409 | static int wb_init(struct bdi_writeback *wb, struct backing_dev_info *bdi, |
Christoph Hellwig | 8c911f3 | 2020-07-01 11:06:21 +0200 | [diff] [blame] | 410 | gfp_t gfp) |
Artem Bityutskiy | 6467716 | 2010-07-25 14:29:22 +0300 | [diff] [blame] | 411 | { |
Tejun Heo | 93f78d8 | 2015-05-22 17:13:27 -0400 | [diff] [blame] | 412 | int i, err; |
| 413 | |
Artem Bityutskiy | 6467716 | 2010-07-25 14:29:22 +0300 | [diff] [blame] | 414 | memset(wb, 0, sizeof(*wb)); |
| 415 | |
| 416 | wb->bdi = bdi; |
| 417 | wb->last_old_flush = jiffies; |
| 418 | INIT_LIST_HEAD(&wb->b_dirty); |
| 419 | INIT_LIST_HEAD(&wb->b_io); |
| 420 | INIT_LIST_HEAD(&wb->b_more_io); |
Theodore Ts'o | 0ae45f6 | 2015-02-02 00:37:00 -0500 | [diff] [blame] | 421 | INIT_LIST_HEAD(&wb->b_dirty_time); |
Christoph Hellwig | f758eea | 2011-04-21 18:19:44 -0600 | [diff] [blame] | 422 | spin_lock_init(&wb->list_lock); |
Tejun Heo | 93f78d8 | 2015-05-22 17:13:27 -0400 | [diff] [blame] | 423 | |
Jan Kara | 633a2ab | 2021-09-02 14:53:04 -0700 | [diff] [blame] | 424 | atomic_set(&wb->writeback_inodes, 0); |
Tejun Heo | a88a341 | 2015-05-22 17:13:28 -0400 | [diff] [blame] | 425 | wb->bw_time_stamp = jiffies; |
| 426 | wb->balanced_dirty_ratelimit = INIT_BW; |
| 427 | wb->dirty_ratelimit = INIT_BW; |
| 428 | wb->write_bandwidth = INIT_BW; |
| 429 | wb->avg_write_bandwidth = INIT_BW; |
| 430 | |
Tejun Heo | f0054bb | 2015-05-22 17:13:30 -0400 | [diff] [blame] | 431 | spin_lock_init(&wb->work_lock); |
| 432 | INIT_LIST_HEAD(&wb->work_list); |
| 433 | INIT_DELAYED_WORK(&wb->dwork, wb_workfn); |
Jan Kara | 45a2966 | 2021-09-02 14:53:09 -0700 | [diff] [blame] | 434 | INIT_DELAYED_WORK(&wb->bw_dwork, wb_update_bandwidth_workfn); |
Jens Axboe | b57d74a | 2016-09-01 10:20:33 -0600 | [diff] [blame] | 435 | wb->dirty_sleep = jiffies; |
Tejun Heo | f0054bb | 2015-05-22 17:13:30 -0400 | [diff] [blame] | 436 | |
Tejun Heo | 8395cd9 | 2015-05-22 17:13:34 -0400 | [diff] [blame] | 437 | err = fprop_local_init_percpu(&wb->completions, gfp); |
Tejun Heo | a88a341 | 2015-05-22 17:13:28 -0400 | [diff] [blame] | 438 | if (err) |
Christoph Hellwig | efee171 | 2021-11-05 13:37:04 -0700 | [diff] [blame] | 439 | return err; |
Tejun Heo | a88a341 | 2015-05-22 17:13:28 -0400 | [diff] [blame] | 440 | |
Tejun Heo | 93f78d8 | 2015-05-22 17:13:27 -0400 | [diff] [blame] | 441 | for (i = 0; i < NR_WB_STAT_ITEMS; i++) { |
Tejun Heo | 8395cd9 | 2015-05-22 17:13:34 -0400 | [diff] [blame] | 442 | err = percpu_counter_init(&wb->stat[i], 0, gfp); |
Tejun Heo | a13f35e | 2015-07-02 08:44:34 -0600 | [diff] [blame] | 443 | if (err) |
| 444 | goto out_destroy_stat; |
Tejun Heo | 93f78d8 | 2015-05-22 17:13:27 -0400 | [diff] [blame] | 445 | } |
| 446 | |
| 447 | return 0; |
Tejun Heo | a13f35e | 2015-07-02 08:44:34 -0600 | [diff] [blame] | 448 | |
| 449 | out_destroy_stat: |
Rasmus Villemoes | 078c6c3 | 2016-02-11 16:13:06 -0800 | [diff] [blame] | 450 | while (i--) |
Tejun Heo | a13f35e | 2015-07-02 08:44:34 -0600 | [diff] [blame] | 451 | percpu_counter_destroy(&wb->stat[i]); |
| 452 | fprop_local_destroy_percpu(&wb->completions); |
Tejun Heo | a13f35e | 2015-07-02 08:44:34 -0600 | [diff] [blame] | 453 | return err; |
Peter Zijlstra | cf0ca9f | 2008-04-30 00:54:32 -0700 | [diff] [blame] | 454 | } |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 455 | |
Jan Kara | e8cb72b | 2017-03-23 01:36:56 +0100 | [diff] [blame] | 456 | static void cgwb_remove_from_bdi_list(struct bdi_writeback *wb); |
| 457 | |
Tejun Heo | 4610007 | 2015-05-22 17:13:31 -0400 | [diff] [blame] | 458 | /* |
| 459 | * Remove bdi from the global list and shutdown any threads we have running |
| 460 | */ |
| 461 | static void wb_shutdown(struct bdi_writeback *wb) |
| 462 | { |
| 463 | /* Make sure nobody queues further work */ |
Khazhismel Kumykov | f87904c | 2022-08-01 08:50:34 -0700 | [diff] [blame] | 464 | spin_lock_irq(&wb->work_lock); |
Tejun Heo | 4610007 | 2015-05-22 17:13:31 -0400 | [diff] [blame] | 465 | if (!test_and_clear_bit(WB_registered, &wb->state)) { |
Khazhismel Kumykov | f87904c | 2022-08-01 08:50:34 -0700 | [diff] [blame] | 466 | spin_unlock_irq(&wb->work_lock); |
Tejun Heo | 4610007 | 2015-05-22 17:13:31 -0400 | [diff] [blame] | 467 | return; |
| 468 | } |
Khazhismel Kumykov | f87904c | 2022-08-01 08:50:34 -0700 | [diff] [blame] | 469 | spin_unlock_irq(&wb->work_lock); |
Tejun Heo | 4610007 | 2015-05-22 17:13:31 -0400 | [diff] [blame] | 470 | |
Jan Kara | e8cb72b | 2017-03-23 01:36:56 +0100 | [diff] [blame] | 471 | cgwb_remove_from_bdi_list(wb); |
Tejun Heo | 4610007 | 2015-05-22 17:13:31 -0400 | [diff] [blame] | 472 | /* |
| 473 | * Drain work list and shutdown the delayed_work. !WB_registered |
| 474 | * tells wb_workfn() that @wb is dying and its work_list needs to |
| 475 | * be drained no matter what. |
| 476 | */ |
| 477 | mod_delayed_work(bdi_wq, &wb->dwork, 0); |
| 478 | flush_delayed_work(&wb->dwork); |
| 479 | WARN_ON(!list_empty(&wb->work_list)); |
Jan Kara | 45a2966 | 2021-09-02 14:53:09 -0700 | [diff] [blame] | 480 | flush_delayed_work(&wb->bw_dwork); |
Tejun Heo | 4610007 | 2015-05-22 17:13:31 -0400 | [diff] [blame] | 481 | } |
| 482 | |
Tejun Heo | f0054bb | 2015-05-22 17:13:30 -0400 | [diff] [blame] | 483 | static void wb_exit(struct bdi_writeback *wb) |
Tejun Heo | 93f78d8 | 2015-05-22 17:13:27 -0400 | [diff] [blame] | 484 | { |
| 485 | int i; |
| 486 | |
| 487 | WARN_ON(delayed_work_pending(&wb->dwork)); |
| 488 | |
| 489 | for (i = 0; i < NR_WB_STAT_ITEMS; i++) |
| 490 | percpu_counter_destroy(&wb->stat[i]); |
Artem Bityutskiy | 6467716 | 2010-07-25 14:29:22 +0300 | [diff] [blame] | 491 | |
Tejun Heo | a88a341 | 2015-05-22 17:13:28 -0400 | [diff] [blame] | 492 | fprop_local_destroy_percpu(&wb->completions); |
| 493 | } |
Wu Fengguang | e98be2d | 2010-08-29 11:22:30 -0600 | [diff] [blame] | 494 | |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 495 | #ifdef CONFIG_CGROUP_WRITEBACK |
| 496 | |
| 497 | #include <linux/memcontrol.h> |
| 498 | |
| 499 | /* |
Roman Gushchin | c22d70a | 2021-06-28 19:36:03 -0700 | [diff] [blame] | 500 | * cgwb_lock protects bdi->cgwb_tree, blkcg->cgwb_list, offline_cgwbs and |
| 501 | * memcg->cgwb_list. bdi->cgwb_tree is also RCU protected. |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 502 | */ |
| 503 | static DEFINE_SPINLOCK(cgwb_lock); |
Tejun Heo | f183464 | 2018-05-23 10:56:32 -0700 | [diff] [blame] | 504 | static struct workqueue_struct *cgwb_release_wq; |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 505 | |
Roman Gushchin | c22d70a | 2021-06-28 19:36:03 -0700 | [diff] [blame] | 506 | static LIST_HEAD(offline_cgwbs); |
| 507 | static void cleanup_offline_cgwbs_workfn(struct work_struct *work); |
| 508 | static DECLARE_WORK(cleanup_offline_cgwbs_work, cleanup_offline_cgwbs_workfn); |
| 509 | |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 510 | static void cgwb_release_workfn(struct work_struct *work) |
| 511 | { |
| 512 | struct bdi_writeback *wb = container_of(work, struct bdi_writeback, |
| 513 | release_work); |
Christoph Hellwig | efee171 | 2021-11-05 13:37:04 -0700 | [diff] [blame] | 514 | struct backing_dev_info *bdi = wb->bdi; |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 515 | |
Jan Kara | 3ee7e86 | 2018-06-18 15:46:58 +0200 | [diff] [blame] | 516 | mutex_lock(&wb->bdi->cgwb_release_mutex); |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 517 | wb_shutdown(wb); |
| 518 | |
| 519 | css_put(wb->memcg_css); |
| 520 | css_put(wb->blkcg_css); |
Jan Kara | 3ee7e86 | 2018-06-18 15:46:58 +0200 | [diff] [blame] | 521 | mutex_unlock(&wb->bdi->cgwb_release_mutex); |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 522 | |
Tejun Heo | d866dbf | 2019-07-24 10:37:22 -0700 | [diff] [blame] | 523 | /* triggers blkg destruction if no online users left */ |
Christoph Hellwig | 397c9f4 | 2022-04-20 06:27:14 +0200 | [diff] [blame] | 524 | blkcg_unpin_online(wb->blkcg_css); |
Dennis Zhou (Facebook) | 59b5771 | 2018-08-31 16:22:43 -0400 | [diff] [blame] | 525 | |
Tejun Heo | 841710a | 2015-05-22 18:23:33 -0400 | [diff] [blame] | 526 | fprop_local_destroy_percpu(&wb->memcg_completions); |
Roman Gushchin | c22d70a | 2021-06-28 19:36:03 -0700 | [diff] [blame] | 527 | |
| 528 | spin_lock_irq(&cgwb_lock); |
| 529 | list_del(&wb->offline_node); |
| 530 | spin_unlock_irq(&cgwb_lock); |
| 531 | |
Roman Gushchin | b43a9e7 | 2021-07-23 15:50:29 -0700 | [diff] [blame] | 532 | percpu_ref_exit(&wb->refcnt); |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 533 | wb_exit(wb); |
Christoph Hellwig | efee171 | 2021-11-05 13:37:04 -0700 | [diff] [blame] | 534 | bdi_put(bdi); |
Roman Gushchin | f3b6a6d | 2021-06-28 19:35:53 -0700 | [diff] [blame] | 535 | WARN_ON_ONCE(!list_empty(&wb->b_attached)); |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 536 | kfree_rcu(wb, rcu); |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 537 | } |
| 538 | |
| 539 | static void cgwb_release(struct percpu_ref *refcnt) |
| 540 | { |
| 541 | struct bdi_writeback *wb = container_of(refcnt, struct bdi_writeback, |
| 542 | refcnt); |
Tejun Heo | f183464 | 2018-05-23 10:56:32 -0700 | [diff] [blame] | 543 | queue_work(cgwb_release_wq, &wb->release_work); |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 544 | } |
| 545 | |
| 546 | static void cgwb_kill(struct bdi_writeback *wb) |
| 547 | { |
| 548 | lockdep_assert_held(&cgwb_lock); |
| 549 | |
| 550 | WARN_ON(!radix_tree_delete(&wb->bdi->cgwb_tree, wb->memcg_css->id)); |
| 551 | list_del(&wb->memcg_node); |
| 552 | list_del(&wb->blkcg_node); |
Roman Gushchin | c22d70a | 2021-06-28 19:36:03 -0700 | [diff] [blame] | 553 | list_add(&wb->offline_node, &offline_cgwbs); |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 554 | percpu_ref_kill(&wb->refcnt); |
| 555 | } |
| 556 | |
Jan Kara | e8cb72b | 2017-03-23 01:36:56 +0100 | [diff] [blame] | 557 | static void cgwb_remove_from_bdi_list(struct bdi_writeback *wb) |
| 558 | { |
| 559 | spin_lock_irq(&cgwb_lock); |
| 560 | list_del_rcu(&wb->bdi_node); |
| 561 | spin_unlock_irq(&cgwb_lock); |
| 562 | } |
| 563 | |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 564 | static int cgwb_create(struct backing_dev_info *bdi, |
| 565 | struct cgroup_subsys_state *memcg_css, gfp_t gfp) |
| 566 | { |
| 567 | struct mem_cgroup *memcg; |
| 568 | struct cgroup_subsys_state *blkcg_css; |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 569 | struct list_head *memcg_cgwb_list, *blkcg_cgwb_list; |
| 570 | struct bdi_writeback *wb; |
| 571 | unsigned long flags; |
| 572 | int ret = 0; |
| 573 | |
| 574 | memcg = mem_cgroup_from_css(memcg_css); |
Tejun Heo | c165b3e | 2015-08-18 14:55:29 -0700 | [diff] [blame] | 575 | blkcg_css = cgroup_get_e_css(memcg_css->cgroup, &io_cgrp_subsys); |
Wang Long | 9ccc361 | 2018-06-07 17:07:19 -0700 | [diff] [blame] | 576 | memcg_cgwb_list = &memcg->cgwb_list; |
Christoph Hellwig | dec223c | 2022-04-20 06:27:15 +0200 | [diff] [blame] | 577 | blkcg_cgwb_list = blkcg_get_cgwb_list(blkcg_css); |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 578 | |
| 579 | /* look up again under lock and discard on blkcg mismatch */ |
| 580 | spin_lock_irqsave(&cgwb_lock, flags); |
| 581 | wb = radix_tree_lookup(&bdi->cgwb_tree, memcg_css->id); |
| 582 | if (wb && wb->blkcg_css != blkcg_css) { |
| 583 | cgwb_kill(wb); |
| 584 | wb = NULL; |
| 585 | } |
| 586 | spin_unlock_irqrestore(&cgwb_lock, flags); |
| 587 | if (wb) |
| 588 | goto out_put; |
| 589 | |
| 590 | /* need to create a new one */ |
| 591 | wb = kmalloc(sizeof(*wb), gfp); |
Christophe JAILLET | 0b045bd | 2017-09-11 21:43:23 +0200 | [diff] [blame] | 592 | if (!wb) { |
| 593 | ret = -ENOMEM; |
| 594 | goto out_put; |
| 595 | } |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 596 | |
Christoph Hellwig | 8c911f3 | 2020-07-01 11:06:21 +0200 | [diff] [blame] | 597 | ret = wb_init(wb, bdi, gfp); |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 598 | if (ret) |
| 599 | goto err_free; |
| 600 | |
| 601 | ret = percpu_ref_init(&wb->refcnt, cgwb_release, 0, gfp); |
| 602 | if (ret) |
| 603 | goto err_wb_exit; |
| 604 | |
Tejun Heo | 841710a | 2015-05-22 18:23:33 -0400 | [diff] [blame] | 605 | ret = fprop_local_init_percpu(&wb->memcg_completions, gfp); |
| 606 | if (ret) |
| 607 | goto err_ref_exit; |
| 608 | |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 609 | wb->memcg_css = memcg_css; |
| 610 | wb->blkcg_css = blkcg_css; |
Roman Gushchin | f3b6a6d | 2021-06-28 19:35:53 -0700 | [diff] [blame] | 611 | INIT_LIST_HEAD(&wb->b_attached); |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 612 | INIT_WORK(&wb->release_work, cgwb_release_workfn); |
| 613 | set_bit(WB_registered, &wb->state); |
Christoph Hellwig | efee171 | 2021-11-05 13:37:04 -0700 | [diff] [blame] | 614 | bdi_get(bdi); |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 615 | |
| 616 | /* |
| 617 | * The root wb determines the registered state of the whole bdi and |
| 618 | * memcg_cgwb_list and blkcg_cgwb_list's next pointers indicate |
| 619 | * whether they're still online. Don't link @wb if any is dead. |
| 620 | * See wb_memcg_offline() and wb_blkcg_offline(). |
| 621 | */ |
| 622 | ret = -ENODEV; |
| 623 | spin_lock_irqsave(&cgwb_lock, flags); |
| 624 | if (test_bit(WB_registered, &bdi->wb.state) && |
| 625 | blkcg_cgwb_list->next && memcg_cgwb_list->next) { |
| 626 | /* we might have raced another instance of this function */ |
| 627 | ret = radix_tree_insert(&bdi->cgwb_tree, memcg_css->id, wb); |
| 628 | if (!ret) { |
Tejun Heo | b817525 | 2015-10-02 14:47:05 -0400 | [diff] [blame] | 629 | list_add_tail_rcu(&wb->bdi_node, &bdi->wb_list); |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 630 | list_add(&wb->memcg_node, memcg_cgwb_list); |
| 631 | list_add(&wb->blkcg_node, blkcg_cgwb_list); |
Christoph Hellwig | 397c9f4 | 2022-04-20 06:27:14 +0200 | [diff] [blame] | 632 | blkcg_pin_online(blkcg_css); |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 633 | css_get(memcg_css); |
| 634 | css_get(blkcg_css); |
| 635 | } |
| 636 | } |
| 637 | spin_unlock_irqrestore(&cgwb_lock, flags); |
| 638 | if (ret) { |
| 639 | if (ret == -EEXIST) |
| 640 | ret = 0; |
Tejun Heo | a13f35e | 2015-07-02 08:44:34 -0600 | [diff] [blame] | 641 | goto err_fprop_exit; |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 642 | } |
| 643 | goto out_put; |
| 644 | |
Tejun Heo | 841710a | 2015-05-22 18:23:33 -0400 | [diff] [blame] | 645 | err_fprop_exit: |
Christoph Hellwig | efee171 | 2021-11-05 13:37:04 -0700 | [diff] [blame] | 646 | bdi_put(bdi); |
Tejun Heo | 841710a | 2015-05-22 18:23:33 -0400 | [diff] [blame] | 647 | fprop_local_destroy_percpu(&wb->memcg_completions); |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 648 | err_ref_exit: |
| 649 | percpu_ref_exit(&wb->refcnt); |
| 650 | err_wb_exit: |
| 651 | wb_exit(wb); |
| 652 | err_free: |
| 653 | kfree(wb); |
| 654 | out_put: |
| 655 | css_put(blkcg_css); |
| 656 | return ret; |
| 657 | } |
| 658 | |
| 659 | /** |
Tejun Heo | ed288dc | 2019-08-26 09:06:54 -0700 | [diff] [blame] | 660 | * wb_get_lookup - get wb for a given memcg |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 661 | * @bdi: target bdi |
| 662 | * @memcg_css: cgroup_subsys_state of the target memcg (must have positive ref) |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 663 | * |
Tejun Heo | ed288dc | 2019-08-26 09:06:54 -0700 | [diff] [blame] | 664 | * Try to get the wb for @memcg_css on @bdi. The returned wb has its |
| 665 | * refcount incremented. |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 666 | * |
| 667 | * This function uses css_get() on @memcg_css and thus expects its refcnt |
| 668 | * to be positive on invocation. IOW, rcu_read_lock() protection on |
| 669 | * @memcg_css isn't enough. try_get it before calling this function. |
| 670 | * |
| 671 | * A wb is keyed by its associated memcg. As blkcg implicitly enables |
| 672 | * memcg on the default hierarchy, memcg association is guaranteed to be |
| 673 | * more specific (equal or descendant to the associated blkcg) and thus can |
| 674 | * identify both the memcg and blkcg associations. |
| 675 | * |
| 676 | * Because the blkcg associated with a memcg may change as blkcg is enabled |
| 677 | * and disabled closer to root in the hierarchy, each wb keeps track of |
| 678 | * both the memcg and blkcg associated with it and verifies the blkcg on |
| 679 | * each lookup. On mismatch, the existing wb is discarded and a new one is |
| 680 | * created. |
| 681 | */ |
Tejun Heo | ed288dc | 2019-08-26 09:06:54 -0700 | [diff] [blame] | 682 | struct bdi_writeback *wb_get_lookup(struct backing_dev_info *bdi, |
| 683 | struct cgroup_subsys_state *memcg_css) |
| 684 | { |
| 685 | struct bdi_writeback *wb; |
| 686 | |
| 687 | if (!memcg_css->parent) |
| 688 | return &bdi->wb; |
| 689 | |
| 690 | rcu_read_lock(); |
| 691 | wb = radix_tree_lookup(&bdi->cgwb_tree, memcg_css->id); |
| 692 | if (wb) { |
| 693 | struct cgroup_subsys_state *blkcg_css; |
| 694 | |
| 695 | /* see whether the blkcg association has changed */ |
| 696 | blkcg_css = cgroup_get_e_css(memcg_css->cgroup, &io_cgrp_subsys); |
| 697 | if (unlikely(wb->blkcg_css != blkcg_css || !wb_tryget(wb))) |
| 698 | wb = NULL; |
| 699 | css_put(blkcg_css); |
| 700 | } |
| 701 | rcu_read_unlock(); |
| 702 | |
| 703 | return wb; |
| 704 | } |
| 705 | |
| 706 | /** |
| 707 | * wb_get_create - get wb for a given memcg, create if necessary |
| 708 | * @bdi: target bdi |
| 709 | * @memcg_css: cgroup_subsys_state of the target memcg (must have positive ref) |
| 710 | * @gfp: allocation mask to use |
| 711 | * |
| 712 | * Try to get the wb for @memcg_css on @bdi. If it doesn't exist, try to |
| 713 | * create one. See wb_get_lookup() for more details. |
| 714 | */ |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 715 | struct bdi_writeback *wb_get_create(struct backing_dev_info *bdi, |
| 716 | struct cgroup_subsys_state *memcg_css, |
| 717 | gfp_t gfp) |
| 718 | { |
| 719 | struct bdi_writeback *wb; |
| 720 | |
Daniel Vetter | c1ca59a | 2021-02-25 17:18:45 -0800 | [diff] [blame] | 721 | might_alloc(gfp); |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 722 | |
| 723 | if (!memcg_css->parent) |
| 724 | return &bdi->wb; |
| 725 | |
| 726 | do { |
Tejun Heo | ed288dc | 2019-08-26 09:06:54 -0700 | [diff] [blame] | 727 | wb = wb_get_lookup(bdi, memcg_css); |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 728 | } while (!wb && !cgwb_create(bdi, memcg_css, gfp)); |
| 729 | |
| 730 | return wb; |
| 731 | } |
| 732 | |
Tejun Heo | a13f35e | 2015-07-02 08:44:34 -0600 | [diff] [blame] | 733 | static int cgwb_bdi_init(struct backing_dev_info *bdi) |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 734 | { |
Tejun Heo | a13f35e | 2015-07-02 08:44:34 -0600 | [diff] [blame] | 735 | int ret; |
| 736 | |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 737 | INIT_RADIX_TREE(&bdi->cgwb_tree, GFP_ATOMIC); |
Jan Kara | 3ee7e86 | 2018-06-18 15:46:58 +0200 | [diff] [blame] | 738 | mutex_init(&bdi->cgwb_release_mutex); |
Tejun Heo | 7fc5854 | 2017-12-12 08:38:30 -0800 | [diff] [blame] | 739 | init_rwsem(&bdi->wb_switch_rwsem); |
Tejun Heo | a13f35e | 2015-07-02 08:44:34 -0600 | [diff] [blame] | 740 | |
Christoph Hellwig | 8c911f3 | 2020-07-01 11:06:21 +0200 | [diff] [blame] | 741 | ret = wb_init(&bdi->wb, bdi, GFP_KERNEL); |
Tejun Heo | a13f35e | 2015-07-02 08:44:34 -0600 | [diff] [blame] | 742 | if (!ret) { |
Johannes Weiner | 7d82860 | 2016-01-14 15:20:56 -0800 | [diff] [blame] | 743 | bdi->wb.memcg_css = &root_mem_cgroup->css; |
Tejun Heo | a13f35e | 2015-07-02 08:44:34 -0600 | [diff] [blame] | 744 | bdi->wb.blkcg_css = blkcg_root_css; |
| 745 | } |
| 746 | return ret; |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 747 | } |
| 748 | |
Jan Kara | b1c51af | 2017-03-23 01:36:59 +0100 | [diff] [blame] | 749 | static void cgwb_bdi_unregister(struct backing_dev_info *bdi) |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 750 | { |
| 751 | struct radix_tree_iter iter; |
| 752 | void **slot; |
Jan Kara | 5318ce7 | 2017-03-23 01:36:57 +0100 | [diff] [blame] | 753 | struct bdi_writeback *wb; |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 754 | |
| 755 | WARN_ON(test_bit(WB_registered, &bdi->wb.state)); |
| 756 | |
| 757 | spin_lock_irq(&cgwb_lock); |
| 758 | radix_tree_for_each_slot(slot, &bdi->cgwb_tree, &iter, 0) |
| 759 | cgwb_kill(*slot); |
Jan Kara | 3ee7e86 | 2018-06-18 15:46:58 +0200 | [diff] [blame] | 760 | spin_unlock_irq(&cgwb_lock); |
Jan Kara | 5318ce7 | 2017-03-23 01:36:57 +0100 | [diff] [blame] | 761 | |
Jan Kara | 3ee7e86 | 2018-06-18 15:46:58 +0200 | [diff] [blame] | 762 | mutex_lock(&bdi->cgwb_release_mutex); |
| 763 | spin_lock_irq(&cgwb_lock); |
Jan Kara | 5318ce7 | 2017-03-23 01:36:57 +0100 | [diff] [blame] | 764 | while (!list_empty(&bdi->wb_list)) { |
| 765 | wb = list_first_entry(&bdi->wb_list, struct bdi_writeback, |
| 766 | bdi_node); |
| 767 | spin_unlock_irq(&cgwb_lock); |
| 768 | wb_shutdown(wb); |
| 769 | spin_lock_irq(&cgwb_lock); |
| 770 | } |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 771 | spin_unlock_irq(&cgwb_lock); |
Jan Kara | 3ee7e86 | 2018-06-18 15:46:58 +0200 | [diff] [blame] | 772 | mutex_unlock(&bdi->cgwb_release_mutex); |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 773 | } |
| 774 | |
Roman Gushchin | c22d70a | 2021-06-28 19:36:03 -0700 | [diff] [blame] | 775 | /* |
| 776 | * cleanup_offline_cgwbs_workfn - try to release dying cgwbs |
| 777 | * |
| 778 | * Try to release dying cgwbs by switching attached inodes to the nearest |
| 779 | * living ancestor's writeback. Processed wbs are placed at the end |
| 780 | * of the list to guarantee the forward progress. |
| 781 | */ |
| 782 | static void cleanup_offline_cgwbs_workfn(struct work_struct *work) |
| 783 | { |
| 784 | struct bdi_writeback *wb; |
| 785 | LIST_HEAD(processed); |
| 786 | |
| 787 | spin_lock_irq(&cgwb_lock); |
| 788 | |
| 789 | while (!list_empty(&offline_cgwbs)) { |
| 790 | wb = list_first_entry(&offline_cgwbs, struct bdi_writeback, |
| 791 | offline_node); |
| 792 | list_move(&wb->offline_node, &processed); |
| 793 | |
| 794 | /* |
| 795 | * If wb is dirty, cleaning up the writeback by switching |
| 796 | * attached inodes will result in an effective removal of any |
| 797 | * bandwidth restrictions, which isn't the goal. Instead, |
| 798 | * it can be postponed until the next time, when all io |
| 799 | * will be likely completed. If in the meantime some inodes |
| 800 | * will get re-dirtied, they should be eventually switched to |
| 801 | * a new cgwb. |
| 802 | */ |
| 803 | if (wb_has_dirty_io(wb)) |
| 804 | continue; |
| 805 | |
| 806 | if (!wb_tryget(wb)) |
| 807 | continue; |
| 808 | |
| 809 | spin_unlock_irq(&cgwb_lock); |
| 810 | while (cleanup_offline_cgwb(wb)) |
| 811 | cond_resched(); |
| 812 | spin_lock_irq(&cgwb_lock); |
| 813 | |
| 814 | wb_put(wb); |
| 815 | } |
| 816 | |
| 817 | if (!list_empty(&processed)) |
| 818 | list_splice_tail(&processed, &offline_cgwbs); |
| 819 | |
| 820 | spin_unlock_irq(&cgwb_lock); |
| 821 | } |
| 822 | |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 823 | /** |
| 824 | * wb_memcg_offline - kill all wb's associated with a memcg being offlined |
| 825 | * @memcg: memcg being offlined |
| 826 | * |
| 827 | * Also prevents creation of any new wb's associated with @memcg. |
| 828 | */ |
| 829 | void wb_memcg_offline(struct mem_cgroup *memcg) |
| 830 | { |
Wang Long | 9ccc361 | 2018-06-07 17:07:19 -0700 | [diff] [blame] | 831 | struct list_head *memcg_cgwb_list = &memcg->cgwb_list; |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 832 | struct bdi_writeback *wb, *next; |
| 833 | |
| 834 | spin_lock_irq(&cgwb_lock); |
| 835 | list_for_each_entry_safe(wb, next, memcg_cgwb_list, memcg_node) |
| 836 | cgwb_kill(wb); |
| 837 | memcg_cgwb_list->next = NULL; /* prevent new wb's */ |
| 838 | spin_unlock_irq(&cgwb_lock); |
Roman Gushchin | c22d70a | 2021-06-28 19:36:03 -0700 | [diff] [blame] | 839 | |
| 840 | queue_work(system_unbound_wq, &cleanup_offline_cgwbs_work); |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 841 | } |
| 842 | |
| 843 | /** |
| 844 | * wb_blkcg_offline - kill all wb's associated with a blkcg being offlined |
Christoph Hellwig | dec223c | 2022-04-20 06:27:15 +0200 | [diff] [blame] | 845 | * @css: blkcg being offlined |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 846 | * |
| 847 | * Also prevents creation of any new wb's associated with @blkcg. |
| 848 | */ |
Christoph Hellwig | dec223c | 2022-04-20 06:27:15 +0200 | [diff] [blame] | 849 | void wb_blkcg_offline(struct cgroup_subsys_state *css) |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 850 | { |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 851 | struct bdi_writeback *wb, *next; |
Christoph Hellwig | dec223c | 2022-04-20 06:27:15 +0200 | [diff] [blame] | 852 | struct list_head *list = blkcg_get_cgwb_list(css); |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 853 | |
| 854 | spin_lock_irq(&cgwb_lock); |
Christoph Hellwig | dec223c | 2022-04-20 06:27:15 +0200 | [diff] [blame] | 855 | list_for_each_entry_safe(wb, next, list, blkcg_node) |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 856 | cgwb_kill(wb); |
Christoph Hellwig | dec223c | 2022-04-20 06:27:15 +0200 | [diff] [blame] | 857 | list->next = NULL; /* prevent new wb's */ |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 858 | spin_unlock_irq(&cgwb_lock); |
| 859 | } |
| 860 | |
Jan Kara | e8cb72b | 2017-03-23 01:36:56 +0100 | [diff] [blame] | 861 | static void cgwb_bdi_register(struct backing_dev_info *bdi) |
| 862 | { |
| 863 | spin_lock_irq(&cgwb_lock); |
| 864 | list_add_tail_rcu(&bdi->wb.bdi_node, &bdi->wb_list); |
| 865 | spin_unlock_irq(&cgwb_lock); |
| 866 | } |
| 867 | |
Tejun Heo | f183464 | 2018-05-23 10:56:32 -0700 | [diff] [blame] | 868 | static int __init cgwb_init(void) |
| 869 | { |
| 870 | /* |
| 871 | * There can be many concurrent release work items overwhelming |
| 872 | * system_wq. Put them in a separate wq and limit concurrency. |
| 873 | * There's no point in executing many of these in parallel. |
| 874 | */ |
| 875 | cgwb_release_wq = alloc_workqueue("cgwb_release", 0, 1); |
| 876 | if (!cgwb_release_wq) |
| 877 | return -ENOMEM; |
| 878 | |
| 879 | return 0; |
| 880 | } |
| 881 | subsys_initcall(cgwb_init); |
| 882 | |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 883 | #else /* CONFIG_CGROUP_WRITEBACK */ |
| 884 | |
Tejun Heo | a13f35e | 2015-07-02 08:44:34 -0600 | [diff] [blame] | 885 | static int cgwb_bdi_init(struct backing_dev_info *bdi) |
| 886 | { |
Christoph Hellwig | 8c911f3 | 2020-07-01 11:06:21 +0200 | [diff] [blame] | 887 | return wb_init(&bdi->wb, bdi, GFP_KERNEL); |
Tejun Heo | a13f35e | 2015-07-02 08:44:34 -0600 | [diff] [blame] | 888 | } |
| 889 | |
Jan Kara | b1c51af | 2017-03-23 01:36:59 +0100 | [diff] [blame] | 890 | static void cgwb_bdi_unregister(struct backing_dev_info *bdi) { } |
Jan Kara | df23de5 | 2017-03-08 17:48:32 +0100 | [diff] [blame] | 891 | |
Jan Kara | e8cb72b | 2017-03-23 01:36:56 +0100 | [diff] [blame] | 892 | static void cgwb_bdi_register(struct backing_dev_info *bdi) |
| 893 | { |
| 894 | list_add_tail_rcu(&bdi->wb.bdi_node, &bdi->wb_list); |
| 895 | } |
| 896 | |
| 897 | static void cgwb_remove_from_bdi_list(struct bdi_writeback *wb) |
| 898 | { |
| 899 | list_del_rcu(&wb->bdi_node); |
| 900 | } |
| 901 | |
Tejun Heo | 52ebea7 | 2015-05-22 17:13:37 -0400 | [diff] [blame] | 902 | #endif /* CONFIG_CGROUP_WRITEBACK */ |
| 903 | |
Jan Kara | 4bca7e8 | 2022-06-15 15:22:29 +0200 | [diff] [blame] | 904 | int bdi_init(struct backing_dev_info *bdi) |
Peter Zijlstra | b2e8fb6 | 2007-10-16 23:25:47 -0700 | [diff] [blame] | 905 | { |
Peter Zijlstra | cf0ca9f | 2008-04-30 00:54:32 -0700 | [diff] [blame] | 906 | bdi->dev = NULL; |
| 907 | |
Jan Kara | d03f6cd | 2017-02-02 15:56:51 +0100 | [diff] [blame] | 908 | kref_init(&bdi->refcnt); |
Peter Zijlstra | 189d3c4 | 2008-04-30 00:54:35 -0700 | [diff] [blame] | 909 | bdi->min_ratio = 0; |
Stefan Roesch | ae82291 | 2022-11-18 16:51:59 -0800 | [diff] [blame] | 910 | bdi->max_ratio = 100 * BDI_RATIO_SCALE; |
Jan Kara | eb608e3 | 2012-05-24 18:59:11 +0200 | [diff] [blame] | 911 | bdi->max_prop_frac = FPROP_FRAC_BASE; |
Jens Axboe | 66f3b8e | 2009-09-02 09:19:46 +0200 | [diff] [blame] | 912 | INIT_LIST_HEAD(&bdi->bdi_list); |
Tejun Heo | b817525 | 2015-10-02 14:47:05 -0400 | [diff] [blame] | 913 | INIT_LIST_HEAD(&bdi->wb_list); |
Tejun Heo | cc395d7 | 2015-05-22 17:13:58 -0400 | [diff] [blame] | 914 | init_waitqueue_head(&bdi->wb_waitq); |
Jens Axboe | 03ba378 | 2009-09-09 09:08:54 +0200 | [diff] [blame] | 915 | |
ye xingchen | 3083da7 | 2022-08-26 07:19:06 +0000 | [diff] [blame] | 916 | return cgwb_bdi_init(bdi); |
Peter Zijlstra | b2e8fb6 | 2007-10-16 23:25:47 -0700 | [diff] [blame] | 917 | } |
Peter Zijlstra | b2e8fb6 | 2007-10-16 23:25:47 -0700 | [diff] [blame] | 918 | |
Christoph Hellwig | aef33c2 | 2020-05-04 14:48:00 +0200 | [diff] [blame] | 919 | struct backing_dev_info *bdi_alloc(int node_id) |
Jan Kara | d03f6cd | 2017-02-02 15:56:51 +0100 | [diff] [blame] | 920 | { |
| 921 | struct backing_dev_info *bdi; |
| 922 | |
Christoph Hellwig | aef33c2 | 2020-05-04 14:48:00 +0200 | [diff] [blame] | 923 | bdi = kzalloc_node(sizeof(*bdi), GFP_KERNEL, node_id); |
Jan Kara | d03f6cd | 2017-02-02 15:56:51 +0100 | [diff] [blame] | 924 | if (!bdi) |
| 925 | return NULL; |
| 926 | |
| 927 | if (bdi_init(bdi)) { |
| 928 | kfree(bdi); |
| 929 | return NULL; |
| 930 | } |
Christoph Hellwig | f56753a | 2020-09-24 08:51:40 +0200 | [diff] [blame] | 931 | bdi->capabilities = BDI_CAP_WRITEBACK | BDI_CAP_WRITEBACK_ACCT; |
Christoph Hellwig | 55b2598 | 2020-09-24 08:51:32 +0200 | [diff] [blame] | 932 | bdi->ra_pages = VM_READAHEAD_PAGES; |
| 933 | bdi->io_pages = VM_READAHEAD_PAGES; |
Christoph Hellwig | 5ed964f | 2021-08-09 16:17:40 +0200 | [diff] [blame] | 934 | timer_setup(&bdi->laptop_mode_wb_timer, laptop_mode_timer_fn, 0); |
Jan Kara | d03f6cd | 2017-02-02 15:56:51 +0100 | [diff] [blame] | 935 | return bdi; |
| 936 | } |
Christoph Hellwig | aef33c2 | 2020-05-04 14:48:00 +0200 | [diff] [blame] | 937 | EXPORT_SYMBOL(bdi_alloc); |
Jan Kara | d03f6cd | 2017-02-02 15:56:51 +0100 | [diff] [blame] | 938 | |
Tejun Heo | 34f8fe5 | 2019-08-26 09:06:53 -0700 | [diff] [blame] | 939 | static struct rb_node **bdi_lookup_rb_node(u64 id, struct rb_node **parentp) |
| 940 | { |
| 941 | struct rb_node **p = &bdi_tree.rb_node; |
| 942 | struct rb_node *parent = NULL; |
| 943 | struct backing_dev_info *bdi; |
| 944 | |
| 945 | lockdep_assert_held(&bdi_lock); |
| 946 | |
| 947 | while (*p) { |
| 948 | parent = *p; |
| 949 | bdi = rb_entry(parent, struct backing_dev_info, rb_node); |
| 950 | |
| 951 | if (bdi->id > id) |
| 952 | p = &(*p)->rb_left; |
| 953 | else if (bdi->id < id) |
| 954 | p = &(*p)->rb_right; |
| 955 | else |
| 956 | break; |
| 957 | } |
| 958 | |
| 959 | if (parentp) |
| 960 | *parentp = parent; |
| 961 | return p; |
| 962 | } |
| 963 | |
| 964 | /** |
| 965 | * bdi_get_by_id - lookup and get bdi from its id |
| 966 | * @id: bdi id to lookup |
| 967 | * |
| 968 | * Find bdi matching @id and get it. Returns NULL if the matching bdi |
| 969 | * doesn't exist or is already unregistered. |
| 970 | */ |
| 971 | struct backing_dev_info *bdi_get_by_id(u64 id) |
| 972 | { |
| 973 | struct backing_dev_info *bdi = NULL; |
| 974 | struct rb_node **p; |
| 975 | |
| 976 | spin_lock_bh(&bdi_lock); |
| 977 | p = bdi_lookup_rb_node(id, NULL); |
| 978 | if (*p) { |
| 979 | bdi = rb_entry(*p, struct backing_dev_info, rb_node); |
| 980 | bdi_get(bdi); |
| 981 | } |
| 982 | spin_unlock_bh(&bdi_lock); |
| 983 | |
| 984 | return bdi; |
| 985 | } |
| 986 | |
Jan Kara | 7c4cc30 | 2017-04-12 12:24:49 +0200 | [diff] [blame] | 987 | 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] | 988 | { |
Peter Zijlstra | b2e8fb6 | 2007-10-16 23:25:47 -0700 | [diff] [blame] | 989 | struct device *dev; |
Tejun Heo | 34f8fe5 | 2019-08-26 09:06:53 -0700 | [diff] [blame] | 990 | struct rb_node *parent, **p; |
Peter Zijlstra | b2e8fb6 | 2007-10-16 23:25:47 -0700 | [diff] [blame] | 991 | |
| 992 | if (bdi->dev) /* The driver needs to use separate queues per device */ |
| 993 | return 0; |
| 994 | |
Christoph Hellwig | 6bd87ee | 2020-05-04 14:47:56 +0200 | [diff] [blame] | 995 | vsnprintf(bdi->dev_name, sizeof(bdi->dev_name), fmt, args); |
| 996 | dev = device_create(bdi_class, NULL, MKDEV(0, 0), bdi, bdi->dev_name); |
Peter Zijlstra | b2e8fb6 | 2007-10-16 23:25:47 -0700 | [diff] [blame] | 997 | if (IS_ERR(dev)) |
| 998 | return PTR_ERR(dev); |
| 999 | |
Jan Kara | e8cb72b | 2017-03-23 01:36:56 +0100 | [diff] [blame] | 1000 | cgwb_bdi_register(bdi); |
Peter Zijlstra | b2e8fb6 | 2007-10-16 23:25:47 -0700 | [diff] [blame] | 1001 | bdi->dev = dev; |
| 1002 | |
Jens Axboe | 6d0e482 | 2017-12-21 10:01:30 -0700 | [diff] [blame] | 1003 | bdi_debug_register(bdi, dev_name(dev)); |
Tejun Heo | 4610007 | 2015-05-22 17:13:31 -0400 | [diff] [blame] | 1004 | set_bit(WB_registered, &bdi->wb.state); |
Peter Zijlstra | b2e8fb6 | 2007-10-16 23:25:47 -0700 | [diff] [blame] | 1005 | |
| 1006 | spin_lock_bh(&bdi_lock); |
Tejun Heo | 34f8fe5 | 2019-08-26 09:06:53 -0700 | [diff] [blame] | 1007 | |
| 1008 | bdi->id = ++bdi_id_cursor; |
| 1009 | |
| 1010 | p = bdi_lookup_rb_node(bdi->id, &parent); |
| 1011 | rb_link_node(&bdi->rb_node, parent, p); |
| 1012 | rb_insert_color(&bdi->rb_node, &bdi_tree); |
| 1013 | |
Peter Zijlstra | b2e8fb6 | 2007-10-16 23:25:47 -0700 | [diff] [blame] | 1014 | list_add_tail_rcu(&bdi->bdi_list, &bdi_list); |
Tejun Heo | 34f8fe5 | 2019-08-26 09:06:53 -0700 | [diff] [blame] | 1015 | |
Peter Zijlstra | b2e8fb6 | 2007-10-16 23:25:47 -0700 | [diff] [blame] | 1016 | spin_unlock_bh(&bdi_lock); |
| 1017 | |
| 1018 | trace_writeback_bdi_register(bdi); |
| 1019 | return 0; |
| 1020 | } |
Jan Kara | baf7a61 | 2017-04-12 12:24:25 +0200 | [diff] [blame] | 1021 | |
Jan Kara | 7c4cc30 | 2017-04-12 12:24:49 +0200 | [diff] [blame] | 1022 | int bdi_register(struct backing_dev_info *bdi, const char *fmt, ...) |
Jan Kara | baf7a61 | 2017-04-12 12:24:25 +0200 | [diff] [blame] | 1023 | { |
| 1024 | va_list args; |
| 1025 | int ret; |
| 1026 | |
| 1027 | va_start(args, fmt); |
Jan Kara | 7c4cc30 | 2017-04-12 12:24:49 +0200 | [diff] [blame] | 1028 | ret = bdi_register_va(bdi, fmt, args); |
Jan Kara | baf7a61 | 2017-04-12 12:24:25 +0200 | [diff] [blame] | 1029 | va_end(args); |
| 1030 | return ret; |
| 1031 | } |
Peter Zijlstra | b2e8fb6 | 2007-10-16 23:25:47 -0700 | [diff] [blame] | 1032 | EXPORT_SYMBOL(bdi_register); |
| 1033 | |
Christoph Hellwig | 3c5d202 | 2020-05-04 14:47:59 +0200 | [diff] [blame] | 1034 | void bdi_set_owner(struct backing_dev_info *bdi, struct device *owner) |
Dan Williams | df08c32 | 2016-07-31 11:15:13 -0700 | [diff] [blame] | 1035 | { |
Christoph Hellwig | 3c5d202 | 2020-05-04 14:47:59 +0200 | [diff] [blame] | 1036 | WARN_ON_ONCE(bdi->owner); |
Dan Williams | df08c32 | 2016-07-31 11:15:13 -0700 | [diff] [blame] | 1037 | bdi->owner = owner; |
| 1038 | get_device(owner); |
Dan Williams | df08c32 | 2016-07-31 11:15:13 -0700 | [diff] [blame] | 1039 | } |
Dan Williams | df08c32 | 2016-07-31 11:15:13 -0700 | [diff] [blame] | 1040 | |
Peter Zijlstra | b2e8fb6 | 2007-10-16 23:25:47 -0700 | [diff] [blame] | 1041 | /* |
Tejun Heo | 4610007 | 2015-05-22 17:13:31 -0400 | [diff] [blame] | 1042 | * 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] | 1043 | */ |
Tejun Heo | 4610007 | 2015-05-22 17:13:31 -0400 | [diff] [blame] | 1044 | static void bdi_remove_from_list(struct backing_dev_info *bdi) |
Peter Zijlstra | 04fbfdc | 2007-10-16 23:25:50 -0700 | [diff] [blame] | 1045 | { |
Tejun Heo | 4610007 | 2015-05-22 17:13:31 -0400 | [diff] [blame] | 1046 | spin_lock_bh(&bdi_lock); |
Tejun Heo | 34f8fe5 | 2019-08-26 09:06:53 -0700 | [diff] [blame] | 1047 | rb_erase(&bdi->rb_node, &bdi_tree); |
Tejun Heo | 4610007 | 2015-05-22 17:13:31 -0400 | [diff] [blame] | 1048 | list_del_rcu(&bdi->bdi_list); |
| 1049 | spin_unlock_bh(&bdi_lock); |
Andrew Morton | 3fcfab1 | 2006-10-19 23:28:16 -0700 | [diff] [blame] | 1050 | |
Tejun Heo | 4610007 | 2015-05-22 17:13:31 -0400 | [diff] [blame] | 1051 | synchronize_rcu_expedited(); |
Andrew Morton | 3fcfab1 | 2006-10-19 23:28:16 -0700 | [diff] [blame] | 1052 | } |
| 1053 | |
Tejun Heo | b02176f | 2015-09-08 12:20:22 -0400 | [diff] [blame] | 1054 | void bdi_unregister(struct backing_dev_info *bdi) |
Andrew Morton | 3fcfab1 | 2006-10-19 23:28:16 -0700 | [diff] [blame] | 1055 | { |
Christoph Hellwig | 5ed964f | 2021-08-09 16:17:40 +0200 | [diff] [blame] | 1056 | del_timer_sync(&bdi->laptop_mode_wb_timer); |
| 1057 | |
Tejun Heo | f0054bb | 2015-05-22 17:13:30 -0400 | [diff] [blame] | 1058 | /* make sure nobody finds us on the bdi_list anymore */ |
| 1059 | bdi_remove_from_list(bdi); |
| 1060 | wb_shutdown(&bdi->wb); |
Jan Kara | b1c51af | 2017-03-23 01:36:59 +0100 | [diff] [blame] | 1061 | cgwb_bdi_unregister(bdi); |
Rabin Vincent | 7a401a9 | 2011-11-11 13:29:04 +0100 | [diff] [blame] | 1062 | |
Manjong Lee | 3c376df | 2021-12-10 14:47:11 -0800 | [diff] [blame] | 1063 | /* |
| 1064 | * If this BDI's min ratio has been set, use bdi_set_min_ratio() to |
| 1065 | * update the global bdi_min_ratio. |
| 1066 | */ |
| 1067 | if (bdi->min_ratio) |
| 1068 | bdi_set_min_ratio(bdi, 0); |
| 1069 | |
Christoph Hellwig | c4db59d | 2015-01-20 14:05:00 -0700 | [diff] [blame] | 1070 | if (bdi->dev) { |
| 1071 | bdi_debug_unregister(bdi); |
| 1072 | device_unregister(bdi->dev); |
| 1073 | bdi->dev = NULL; |
| 1074 | } |
Dan Williams | df08c32 | 2016-07-31 11:15:13 -0700 | [diff] [blame] | 1075 | |
| 1076 | if (bdi->owner) { |
| 1077 | put_device(bdi->owner); |
| 1078 | bdi->owner = NULL; |
| 1079 | } |
Tejun Heo | b02176f | 2015-09-08 12:20:22 -0400 | [diff] [blame] | 1080 | } |
Christoph Hellwig | c6fd3ac | 2021-11-05 13:36:52 -0700 | [diff] [blame] | 1081 | EXPORT_SYMBOL(bdi_unregister); |
Christoph Hellwig | c4db59d | 2015-01-20 14:05:00 -0700 | [diff] [blame] | 1082 | |
Jan Kara | d03f6cd | 2017-02-02 15:56:51 +0100 | [diff] [blame] | 1083 | static void release_bdi(struct kref *ref) |
| 1084 | { |
| 1085 | struct backing_dev_info *bdi = |
| 1086 | container_of(ref, struct backing_dev_info, refcnt); |
| 1087 | |
Christoph Hellwig | 702f2d1 | 2021-11-05 13:37:01 -0700 | [diff] [blame] | 1088 | WARN_ON_ONCE(test_bit(WB_registered, &bdi->wb.state)); |
Jan Kara | 2e82b84 | 2017-04-12 12:24:48 +0200 | [diff] [blame] | 1089 | WARN_ON_ONCE(bdi->dev); |
| 1090 | wb_exit(&bdi->wb); |
Jan Kara | d03f6cd | 2017-02-02 15:56:51 +0100 | [diff] [blame] | 1091 | kfree(bdi); |
| 1092 | } |
| 1093 | |
| 1094 | void bdi_put(struct backing_dev_info *bdi) |
| 1095 | { |
| 1096 | kref_put(&bdi->refcnt, release_bdi); |
| 1097 | } |
Jan Kara | 62bf42a | 2017-04-12 12:24:27 +0200 | [diff] [blame] | 1098 | EXPORT_SYMBOL(bdi_put); |
Jan Kara | d03f6cd | 2017-02-02 15:56:51 +0100 | [diff] [blame] | 1099 | |
Christoph Hellwig | ccdf774 | 2021-09-20 14:33:14 +0200 | [diff] [blame] | 1100 | struct backing_dev_info *inode_to_bdi(struct inode *inode) |
| 1101 | { |
| 1102 | struct super_block *sb; |
| 1103 | |
| 1104 | if (!inode) |
| 1105 | return &noop_backing_dev_info; |
| 1106 | |
| 1107 | sb = inode->i_sb; |
| 1108 | #ifdef CONFIG_BLOCK |
| 1109 | if (sb_is_blkdev_sb(sb)) |
| 1110 | return I_BDEV(inode)->bd_disk->bdi; |
| 1111 | #endif |
| 1112 | return sb->s_bdi; |
| 1113 | } |
| 1114 | EXPORT_SYMBOL(inode_to_bdi); |
| 1115 | |
Christoph Hellwig | eb7ae5e | 2020-05-04 14:47:54 +0200 | [diff] [blame] | 1116 | const char *bdi_dev_name(struct backing_dev_info *bdi) |
| 1117 | { |
| 1118 | if (!bdi || !bdi->dev) |
| 1119 | return bdi_unknown_name; |
Christoph Hellwig | 6bd87ee | 2020-05-04 14:47:56 +0200 | [diff] [blame] | 1120 | return bdi->dev_name; |
Christoph Hellwig | eb7ae5e | 2020-05-04 14:47:54 +0200 | [diff] [blame] | 1121 | } |
| 1122 | EXPORT_SYMBOL_GPL(bdi_dev_name); |