path: root/block/bfq-iosched.c
diff options
authorTang Junhui <>2018-02-07 11:41:46 -0800
committerJens Axboe <>2018-02-07 12:50:01 -0700
commit73ac105be390c1de42a2f21643c9778a5e002930 (patch)
tree9a9920614c0e4092f4479413d631912c58e5c952 /block/bfq-iosched.c
parent7f4fc93d4713394ee8f1cd44c238e046e11b4f15 (diff)
bcache: fix for data collapse after re-attaching an attached device
back-end device sdm has already attached a cache_set with ID f67ebe1f-f8bc-4d73-bfe5-9dc88607f119, then try to attach with another cache set, and it returns with an error: [root]# cd /sys/block/sdm/bcache [root]# echo 5ccd0a63-148e-48b8-afa2-aca9cbd6279f > attach -bash: echo: write error: Invalid argument After that, execute a command to modify the label of bcache device: [root]# echo data_disk1 > label Then we reboot the system, when the system power on, the back-end device can not attach to cache_set, a messages show in the log: Feb 5 12:05:52 ceph152 kernel: [922385.508498] bcache: bch_cached_dev_attach() couldn't find uuid for sdm in set In sysfs_attach(), dc->sb.set_uuid was assigned to the value which input through sysfs, no matter whether it is success or not in bch_cached_dev_attach(). For example, If the back-end device has already attached to an cache set, bch_cached_dev_attach() would fail, but dc->sb.set_uuid was changed. Then modify the label of bcache device, it will call bch_write_bdev_super(), which would write the dc->sb.set_uuid to the super block, so we record a wrong cache set ID in the super block, after the system reboot, the cache set couldn't find the uuid of the back-end device, so the bcache device couldn't exist and use any more. In this patch, we don't assigned cache set ID to dc->sb.set_uuid in sysfs_attach() directly, but input it into bch_cached_dev_attach(), and assigned dc->sb.set_uuid to the cache set ID after the back-end device attached to the cache set successful. Signed-off-by: Tang Junhui <> Reviewed-by: Michael Lyle <> Signed-off-by: Jens Axboe <>
Diffstat (limited to 'block/bfq-iosched.c')
0 files changed, 0 insertions, 0 deletions