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| author | Shenghui Wang <shhuiw@foxmail.com> | 2018-12-13 22:53:51 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2018-12-13 08:15:54 -0700 |
| commit | f383ae300c4b6466824fd5c8cbd0a6c4ed2b53d3 (patch) | |
| tree | 7e68c2e8cfd414d4c94f9493adb1335cfceeb925 /drivers/md/bcache | |
| parent | 79b791466e525c98f6aeee9acf5726e7b27f4231 (diff) | |
| download | linux-f383ae300c4b6466824fd5c8cbd0a6c4ed2b53d3.tar.gz | |
bcache: cannot set writeback_running via sysfs if no writeback kthread created
"echo 1 > writeback_running" marks writeback_running even if no writeback kthread created as "d_strtoul(writeback_running)" will simply set dc-> writeback_running without checking the existence of dc->writeback_thread. Add check for setting writeback_running via sysfs: if no writeback kthread available, reject setting to 1. v2 -> v3: * Make message on wrong assignment more clear. * Print name of bcache device instead of name of backing device. Signed-off-by: Shenghui Wang <shhuiw@foxmail.com> Signed-off-by: Coly Li <colyli@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/md/bcache')
| -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)) |