btrfs: sysfs: protect reading label by lock
authorDavid Sterba <dsterba@suse.com>
Tue, 26 Apr 2016 14:22:06 +0000 (16:22 +0200)
committerDavid Sterba <dsterba@suse.com>
Fri, 6 May 2016 13:22:49 +0000 (15:22 +0200)
commitee17fc8005287d2d6ca7cab6e814e5043d773735
tree17d8f4c3a5bf27587fa7dadf730a2ef4f88798cd
parent66ac9fe7bacf9fa76c472efc7a7aaa590c7bce6a
btrfs: sysfs: protect reading label by lock

If the label setting ioctl races with sysfs label handler, we could get
mixed result in the output, part old part new. We should either get the
old or new label. The chances to hit this race are low.

Signed-off-by: David Sterba <dsterba@suse.com>
fs/btrfs/sysfs.c