dm snapshot: use mutex instead of rw_semaphore
authorMikulas Patocka <mpatocka@redhat.com>
Thu, 23 Nov 2017 21:15:43 +0000 (16:15 -0500)
committerMike Snitzer <snitzer@redhat.com>
Wed, 17 Jan 2018 14:16:14 +0000 (09:16 -0500)
commitae1093be5a0ef997833e200a0dafb9ed0b1ff4fe
tree89fc4c9f1ff7226bb157c8ccf92b265186c02747
parent7690e25302dc7d0cd42b349e746fe44b44a94f2b
dm snapshot: use mutex instead of rw_semaphore

The rw_semaphore is acquired for read only in two places, neither is
performance-critical.  So replace it with a mutex -- which is more
efficient.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
drivers/md/dm-snap.c