From f9bebd580360c141b5fdbede9cc13a4caf23cd1a Mon Sep 17 00:00:00 2001 From: Ilya Dryomov Date: Thu, 13 Apr 2017 12:17:39 +0200 Subject: [PATCH] rbd: kill rbd_is_lock_supported() Currently the exclusive lock is acquired only if the mapping is writable, i.e. an image HEAD mapped in rw mode. This means that we don't acquire the lock for executing a read from a snapshot or an image HEAD mapped in ro mode, even if lock_on_read is set. This is somewhat weird and inconsistent with "no automatic exclusive lock transfers" mode, where the lock is acquired unconditionally. Signed-off-by: Ilya Dryomov Reviewed-by: Jason Dillaman --- drivers/block/rbd.c | 14 +++----------- 1 file changed, 3 insertions(+), 11 deletions(-) diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 063c8f0..e3fafaf 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -478,13 +478,6 @@ static int minor_to_rbd_dev_id(int minor) return minor >> RBD_SINGLE_MAJOR_PART_SHIFT; } -static bool rbd_is_lock_supported(struct rbd_device *rbd_dev) -{ - return (rbd_dev->header.features & RBD_FEATURE_EXCLUSIVE_LOCK) && - rbd_dev->spec->snap_id == CEPH_NOSNAP && - !rbd_dev->mapping.read_only; -} - static bool __rbd_is_lock_owner(struct rbd_device *rbd_dev) { return rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED || @@ -4052,10 +4045,6 @@ static void rbd_queue_workfn(struct work_struct *work) if (op_type != OBJ_OP_READ) { snapc = rbd_dev->header.snapc; ceph_get_snap_context(snapc); - must_be_locked = rbd_is_lock_supported(rbd_dev); - } else { - must_be_locked = rbd_dev->opts->lock_on_read && - rbd_is_lock_supported(rbd_dev); } up_read(&rbd_dev->header_rwsem); @@ -4066,6 +4055,9 @@ static void rbd_queue_workfn(struct work_struct *work) goto err_rq; } + must_be_locked = + (rbd_dev->header.features & RBD_FEATURE_EXCLUSIVE_LOCK) && + (op_type != OBJ_OP_READ || rbd_dev->opts->lock_on_read); if (must_be_locked) { down_read(&rbd_dev->lock_rwsem); if (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED && -- 2.7.4