Commit 505cbb9b authored Jul 19, 2012 by Alex Elder Committed by Sage Weil Jul 30, 2012

rbd: set snapc->seq only when refreshing header



In rbd_header_add_snap() there is code to set snapc->seq to the
just-added snapshot id.  This is the only remnant left of the
use of that field for recording which snapshot an rbd_dev was
associated with.  That functionality is no longer supported,
so get rid of that final bit of code.

Doing so means we never actually set snapc->seq any more.  On the
server, the snapshot context's sequence value represents the highest
snapshot id ever issued for a particular rbd image.  So we'll make
it have that meaning here as well.  To do so, set this value
whenever the rbd header is (re-)read.  That way it will always be
consistent with the rest of the snapshot context we maintain.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

parent 78dc447d

drivers/block/rbd.c

+2 −8

Original line number	Original line	Diff line number	Diff line
	@@ -537,6 +537,7 @@ static int rbd_header_from_disk(struct rbd_image_header *header,

	atomic_set(&header->snapc->nref, 1);		atomic_set(&header->snapc->nref, 1);
	header->snap_seq = le64_to_cpu(ondisk->snap_seq);		header->snap_seq = le64_to_cpu(ondisk->snap_seq);
			header->snapc->seq = le64_to_cpu(ondisk->snap_seq);
	header->snapc->num_snaps = snap_count;		header->snapc->num_snaps = snap_count;
	header->total_snaps = snap_count;		header->total_snaps = snap_count;

	@@ -1685,14 +1686,7 @@ static int rbd_header_add_snap(struct rbd_device *rbd_dev,

	kfree(data);		kfree(data);

	if (ret < 0)		return ret < 0 ? ret : 0;
	return ret;

	down_write(&rbd_dev->header_rwsem);
	rbd_dev->header.snapc->seq = new_snapid;
	up_write(&rbd_dev->header_rwsem);

	return 0;
	bad:		bad:
	return -ERANGE;		return -ERANGE;
	}		}