diff options
| -rw-r--r-- | drivers/md/bcache/sysfs.c | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c index d2e5c9892d4d..9d5fe12f0c9c 100644 --- a/drivers/md/bcache/sysfs.c +++ b/drivers/md/bcache/sysfs.c @@ -384,8 +384,25 @@ STORE(bch_cached_dev) mutex_lock(&bch_register_lock); size = __cached_dev_store(kobj, attr, buf, size); - if (attr == &sysfs_writeback_running) - bch_writeback_queue(dc); + if (attr == &sysfs_writeback_running) { + /* dc->writeback_running changed in __cached_dev_store() */ + if (IS_ERR_OR_NULL(dc->writeback_thread)) { + /* + * reject setting it to 1 via sysfs if writeback + * kthread is not created yet. + */ + if (dc->writeback_running) { + dc->writeback_running = false; + pr_err("%s: failed to run non-existent writeback thread", + dc->disk.disk->disk_name); + } + } else + /* + * writeback kthread will check if dc->writeback_running + * is true or false. + */ + bch_writeback_queue(dc); + } if (attr == &sysfs_writeback_percent) if (!test_and_set_bit(BCACHE_DEV_WB_RUNNING, &dc->disk.flags)) |