3.18-stable review patch. If anyone has any objections, please let me know.
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From: Tang Junhui tang.junhui@zte.com.cn
[ Upstream commit 73ac105be390c1de42a2f21643c9778a5e002930 ]
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 tang.junhui@zte.com.cn Reviewed-by: Michael Lyle mlyle@lyle.org Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/md/bcache/bcache.h | 2 +- drivers/md/bcache/super.c | 10 ++++++---- drivers/md/bcache/sysfs.c | 6 ++++-- 3 files changed, 11 insertions(+), 7 deletions(-)
--- a/drivers/md/bcache/bcache.h +++ b/drivers/md/bcache/bcache.h @@ -922,7 +922,7 @@ void bcache_write_super(struct cache_set
int bch_flash_dev_create(struct cache_set *c, uint64_t size);
-int bch_cached_dev_attach(struct cached_dev *, struct cache_set *); +int bch_cached_dev_attach(struct cached_dev *, struct cache_set *, uint8_t *); void bch_cached_dev_detach(struct cached_dev *); void bch_cached_dev_run(struct cached_dev *); void bcache_device_stop(struct bcache_device *); --- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -967,7 +967,8 @@ void bch_cached_dev_detach(struct cached cached_dev_put(dc); }
-int bch_cached_dev_attach(struct cached_dev *dc, struct cache_set *c) +int bch_cached_dev_attach(struct cached_dev *dc, struct cache_set *c, + uint8_t *set_uuid) { uint32_t rtime = cpu_to_le32(get_seconds()); struct uuid_entry *u; @@ -975,7 +976,8 @@ int bch_cached_dev_attach(struct cached_
bdevname(dc->bdev, buf);
- if (memcmp(dc->sb.set_uuid, c->sb.set_uuid, 16)) + if ((set_uuid && memcmp(set_uuid, c->sb.set_uuid, 16)) || + (!set_uuid && memcmp(dc->sb.set_uuid, c->sb.set_uuid, 16))) return -ENOENT;
if (dc->disk.c) { @@ -1209,7 +1211,7 @@ static void register_bdev(struct cache_s
list_add(&dc->list, &uncached_devices); list_for_each_entry(c, &bch_cache_sets, list) - bch_cached_dev_attach(dc, c); + bch_cached_dev_attach(dc, c, NULL);
if (BDEV_STATE(&dc->sb) == BDEV_STATE_NONE || BDEV_STATE(&dc->sb) == BDEV_STATE_STALE) @@ -1729,7 +1731,7 @@ static void run_cache_set(struct cache_s bcache_write_super(c);
list_for_each_entry_safe(dc, t, &uncached_devices, list) - bch_cached_dev_attach(dc, c); + bch_cached_dev_attach(dc, c, NULL);
flash_devs_run(c);
--- a/drivers/md/bcache/sysfs.c +++ b/drivers/md/bcache/sysfs.c @@ -263,11 +263,13 @@ STORE(__cached_dev) }
if (attr == &sysfs_attach) { - if (bch_parse_uuid(buf, dc->sb.set_uuid) < 16) + uint8_t set_uuid[16]; + + if (bch_parse_uuid(buf, set_uuid) < 16) return -EINVAL;
list_for_each_entry(c, &bch_cache_sets, list) { - v = bch_cached_dev_attach(dc, c); + v = bch_cached_dev_attach(dc, c, set_uuid); if (!v) return size; }