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| author |   Coly Li <colyli@suse.de> | 2019-02-09 12:52:56 +0800 |
|---|---|---|
| committer |   Jens Axboe <axboe@kernel.dk> | 2019-02-09 07:18:31 -0700 |
| commit | d4610456cfa412811b749f6215b9adae976ab4c3 (patch) | |
| tree | aed9005a0d5c2bfb10c9c4d19814e1cad54cb76d /drivers/md/bcache | |
| parent | bcache: export backing_dev_name via sysfs (diff) | |
| download | linux-dev-d4610456cfa412811b749f6215b9adae976ab4c3.tar.xz linux-dev-d4610456cfa412811b749f6215b9adae976ab4c3.zip | |
bcache: export backing_dev_uuid via sysfs
When there are multiple bcache devices, after a reboot the name of
bcache devices may change (e.g. current /dev/bcache1 was /dev/bcache0
before reboot). Therefore we need the backing device UUID (sb.uuid) to
identify each bcache device.
Backing device uuid can be found by program bcache-super-show, but
directly exporting backing_dev_uuid by sysfs file
/sys/block/bcache<?>/bcache/backing_dev_uuid is a much simpler method.
With backing_dev_uuid, and partition uuids from /dev/disk/by-partuuid/,
now we can identify each bcache device and its partitions conveniently.
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 | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c index b9166ee027fa..9be27b26d300 100644 --- a/drivers/md/bcache/sysfs.c +++ b/drivers/md/bcache/sysfs.c @@ -68,6 +68,7 @@ read_attribute(btree_written); read_attribute(metadata_written); read_attribute(active_journal_entries); read_attribute(backing_dev_name); +read_attribute(backing_dev_uuid); sysfs_time_stats_attribute(btree_gc, sec, ms); sysfs_time_stats_attribute(btree_split, sec, us); @@ -250,6 +251,13 @@ SHOW(__bch_cached_dev) return strlen(buf); } + if (attr == &sysfs_backing_dev_uuid) { + /* convert binary uuid into 36-byte string plus '\0' */ + snprintf(buf, 36+1, "%pU", dc->sb.uuid); + strcat(buf, "\n"); + return strlen(buf); + } + #undef var return 0; } @@ -460,6 +468,7 @@ static struct attribute *bch_cached_dev_files[] = { &sysfs_bypass_torture_test, #endif &sysfs_backing_dev_name, + &sysfs_backing_dev_uuid, NULL }; KTYPE(bch_cached_dev); |