From a3fbe5d447bf1f63efa7f4d8c222002ef136cf4b Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Tue, 30 Apr 2013 00:44:32 -0500 Subject: [PATCH] rbd: don't revalidate so much Whenever a header object event causes a mapped rbd image to refresh its header information, revalidate_disk() is being called. This was done in rbd_dev_refresh() outside the control mutex in order to avoid a lock inversion. Although a an event like this *might* indicate the image has changed size, most of the time it does not. Record the image size before and after the refresh, and only call revalidate_disk() if it changes. This resolves: http://tracker.ceph.com/issues/4867 Signed-off-by: Alex Elder Reviewed-by: Josh Durgin --- drivers/block/rbd.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 71e2de2cff22..ab2c788a22ad 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -3065,19 +3065,22 @@ static int rbd_dev_v1_refresh(struct rbd_device *rbd_dev, u64 *hver) static int rbd_dev_refresh(struct rbd_device *rbd_dev, u64 *hver) { + u64 image_size; int ret; rbd_assert(rbd_image_format_valid(rbd_dev->image_format)); + image_size = rbd_dev->header.image_size; mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING); if (rbd_dev->image_format == 1) ret = rbd_dev_v1_refresh(rbd_dev, hver); else ret = rbd_dev_v2_refresh(rbd_dev, hver); mutex_unlock(&ctl_mutex); - revalidate_disk(rbd_dev->disk); if (ret) rbd_warn(rbd_dev, "got notification but failed to " " update snaps: %d\n", ret); + if (image_size != rbd_dev->header.image_size) + revalidate_disk(rbd_dev->disk); return ret; }