| Message ID | 1521541979-15995-2-git-send-email-dongsheng.yang@easystack.cn (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Mar 20, 2018 at 11:32 AM, Dongsheng Yang <dongsheng.yang@easystack.cn> wrote: > currently, the rbd_wait_state_locked() will wait forever if we > can't get our state locked. Example: > > rbd map --exclusive test1 --> /dev/rbd0 > rbd map test1 --> /dev/rbd1 > dd if=/dev/zero of=/dev/rbd1 bs=1M count=1 --> IO blocked > > To avoid this problem, this patch introduce a timeout design > in rbd_wait_state_locked(). Then rbd_wait_state_locked() will > return error when we reach a timeout. > > Signed-off-by: Dongsheng Yang <dongsheng.yang@easystack.cn> > --- > drivers/block/rbd.c | 23 +++++++++++++++++++---- > 1 file changed, 19 insertions(+), 4 deletions(-) > > diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c > index 96657ad..199819d 100644 > --- a/drivers/block/rbd.c > +++ b/drivers/block/rbd.c > @@ -761,6 +761,7 @@ struct rbd_options { > #define RBD_READ_ONLY_DEFAULT false > #define RBD_LOCK_ON_READ_DEFAULT false > #define RBD_EXCLUSIVE_DEFAULT false > +#define RBD_WAIT_LOCK_TIMEOUT_DEFAULT MAX_SCHEDULE_TIMEOUT #define RBD_LOCK_TIMEOUT_DEFAULT 0 /* no timeout */ Passing lock_timeout=0 on the command line for "no timeout" must be supported. 0 -> MAX_SCHEDULE_TIMEOUT will be handled by ceph_timeout_jiffies() in rbd_wait_state_locked(). > > static int parse_rbd_opts_token(char *c, void *private) > { > @@ -3494,8 +3495,9 @@ static int rbd_obj_method_sync(struct rbd_device *rbd_dev, > /* > * lock_rwsem must be held for read > */ > -static void rbd_wait_state_locked(struct rbd_device *rbd_dev) > +static int rbd_wait_state_locked(struct rbd_device *rbd_dev) > { > + long timeo = RBD_WAIT_LOCK_TIMEOUT_DEFAULT; > DEFINE_WAIT(wait); > > do { > @@ -3508,12 +3510,18 @@ static void rbd_wait_state_locked(struct rbd_device *rbd_dev) > prepare_to_wait_exclusive(&rbd_dev->lock_waitq, &wait, > TASK_UNINTERRUPTIBLE); > up_read(&rbd_dev->lock_rwsem); > - schedule(); > + timeo = schedule_timeout(timeo); > down_read(&rbd_dev->lock_rwsem); > + if (!timeo) { > + finish_wait(&rbd_dev->lock_waitq, &wait); > + rbd_warn(rbd_dev, "timed out in waiting state locked"); "timed out waiting for lock" > + return -ETIMEDOUT; > + } > } while (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED && > !test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags)); > > finish_wait(&rbd_dev->lock_waitq, &wait); > + return 0; > } > > static void rbd_queue_workfn(struct work_struct *work) > @@ -3606,7 +3614,9 @@ static void rbd_queue_workfn(struct work_struct *work) > result = -EROFS; > goto err_unlock; > } > - rbd_wait_state_locked(rbd_dev); > + result = rbd_wait_state_locked(rbd_dev); > + if (result) > + goto err_unlock; > } > if (test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags)) { > result = -EBLACKLISTED; > @@ -5261,6 +5271,8 @@ static void rbd_dev_image_unlock(struct rbd_device *rbd_dev) > > static int rbd_add_acquire_lock(struct rbd_device *rbd_dev) > { > + int ret = 0; > + > if (!(rbd_dev->header.features & RBD_FEATURE_EXCLUSIVE_LOCK)) { > rbd_warn(rbd_dev, "exclusive-lock feature is not enabled"); > return -EINVAL; > @@ -5268,8 +5280,11 @@ static int rbd_add_acquire_lock(struct rbd_device *rbd_dev) > > /* FIXME: "rbd map --exclusive" should be in interruptible */ > down_read(&rbd_dev->lock_rwsem); > - rbd_wait_state_locked(rbd_dev); > + ret = rbd_wait_state_locked(rbd_dev); > up_read(&rbd_dev->lock_rwsem); > + if (ret) { > + return ret; > + } Unneeded braces. Thanks, Ilya -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 96657ad..199819d 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -761,6 +761,7 @@ struct rbd_options { #define RBD_READ_ONLY_DEFAULT false #define RBD_LOCK_ON_READ_DEFAULT false #define RBD_EXCLUSIVE_DEFAULT false +#define RBD_WAIT_LOCK_TIMEOUT_DEFAULT MAX_SCHEDULE_TIMEOUT static int parse_rbd_opts_token(char *c, void *private) { @@ -3494,8 +3495,9 @@ static int rbd_obj_method_sync(struct rbd_device *rbd_dev, /* * lock_rwsem must be held for read */ -static void rbd_wait_state_locked(struct rbd_device *rbd_dev) +static int rbd_wait_state_locked(struct rbd_device *rbd_dev) { + long timeo = RBD_WAIT_LOCK_TIMEOUT_DEFAULT; DEFINE_WAIT(wait); do { @@ -3508,12 +3510,18 @@ static void rbd_wait_state_locked(struct rbd_device *rbd_dev) prepare_to_wait_exclusive(&rbd_dev->lock_waitq, &wait, TASK_UNINTERRUPTIBLE); up_read(&rbd_dev->lock_rwsem); - schedule(); + timeo = schedule_timeout(timeo); down_read(&rbd_dev->lock_rwsem); + if (!timeo) { + finish_wait(&rbd_dev->lock_waitq, &wait); + rbd_warn(rbd_dev, "timed out in waiting state locked"); + return -ETIMEDOUT; + } } while (rbd_dev->lock_state != RBD_LOCK_STATE_LOCKED && !test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags)); finish_wait(&rbd_dev->lock_waitq, &wait); + return 0; } static void rbd_queue_workfn(struct work_struct *work) @@ -3606,7 +3614,9 @@ static void rbd_queue_workfn(struct work_struct *work) result = -EROFS; goto err_unlock; } - rbd_wait_state_locked(rbd_dev); + result = rbd_wait_state_locked(rbd_dev); + if (result) + goto err_unlock; } if (test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags)) { result = -EBLACKLISTED; @@ -5261,6 +5271,8 @@ static void rbd_dev_image_unlock(struct rbd_device *rbd_dev) static int rbd_add_acquire_lock(struct rbd_device *rbd_dev) { + int ret = 0; + if (!(rbd_dev->header.features & RBD_FEATURE_EXCLUSIVE_LOCK)) { rbd_warn(rbd_dev, "exclusive-lock feature is not enabled"); return -EINVAL; @@ -5268,8 +5280,11 @@ static int rbd_add_acquire_lock(struct rbd_device *rbd_dev) /* FIXME: "rbd map --exclusive" should be in interruptible */ down_read(&rbd_dev->lock_rwsem); - rbd_wait_state_locked(rbd_dev); + ret = rbd_wait_state_locked(rbd_dev); up_read(&rbd_dev->lock_rwsem); + if (ret) { + return ret; + } if (test_bit(RBD_DEV_FLAG_BLACKLISTED, &rbd_dev->flags)) { rbd_warn(rbd_dev, "failed to acquire exclusive lock"); return -EROFS;
currently, the rbd_wait_state_locked() will wait forever if we can't get our state locked. Example: rbd map --exclusive test1 --> /dev/rbd0 rbd map test1 --> /dev/rbd1 dd if=/dev/zero of=/dev/rbd1 bs=1M count=1 --> IO blocked To avoid this problem, this patch introduce a timeout design in rbd_wait_state_locked(). Then rbd_wait_state_locked() will return error when we reach a timeout. Signed-off-by: Dongsheng Yang <dongsheng.yang@easystack.cn> --- drivers/block/rbd.c | 23 +++++++++++++++++++---- 1 file changed, 19 insertions(+), 4 deletions(-)