p71924506
/
linux_old1
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

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 <idryomov@gmail.com>
Reviewed-by: Jason Dillaman <dillaman@redhat.com>
This commit is contained in:
Ilya Dryomov 2017-04-13 12:17:39 +02:00
parent 14bb211d32
commit f9bebd5803
1 changed files with 3 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
drivers/block/rbd.c
View File

@ -478,13 +478,6 @@ static int minor_to_rbd_dev_id(int minor)
return minor >> RBD_SINGLE_MAJOR_PART_SHIFT; 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) static bool __rbd_is_lock_owner(struct rbd_device *rbd_dev)
{ {
return rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED || 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) { if (op_type != OBJ_OP_READ) {
snapc = rbd_dev->header.snapc; snapc = rbd_dev->header.snapc;
ceph_get_snap_context(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); up_read(&rbd_dev->header_rwsem);
@ -4066,6 +4055,9 @@ static void rbd_queue_workfn(struct work_struct *work)
goto err_rq; 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) { if (must_be_locked) {
down_read(&rbd_dev->lock_rwsem); down_read(&rbd_dev->lock_rwsem);
if (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED && if (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED &&