On Thu, Jun 06, 2019 at 04:52:18PM +0300, Nikolay Borisov wrote: > A (D)ouble (R)eader (W)riter lock is a locking primitive that allows > to have multiple readers or multiple writers but not multiple readers > and writers holding it concurrently. The code is factored out from > the existing open-coded locking scheme used to exclude pending > snapshots from nocow writers and vice-versa. Current implementation > actually favors Readers (that is snapshot creaters) to writers (nocow > writers of the filesystem). > > Signed-off-by: Nikolay Borisov <[email protected]> > --- > fs/btrfs/Makefile | 2 +- > fs/btrfs/drw_lock.c | 71 +++++++++++++++++++++++++++++++++++++++++++++ > fs/btrfs/drw_lock.h | 23 +++++++++++++++
In v2, please use locking.[ch] instead of new files.
