ceph: queue_cap_snap should always queue dirty context
This simplifies the calling convention, and fixes a bug where we queue a
capsnap with a context other than i_head_snapc (the one that matches the
dirty pages). The result was a BUG at fs/ceph/caps.c:2178 on writeback
completion when a capsnap matching the writeback snapc could not be found.
Signed-off-by: Sage Weil <sage@newdream.net>
diff --git a/fs/ceph/snap.c b/fs/ceph/snap.c
index 7e3e5f9..d1974315 100644
--- a/fs/ceph/snap.c
+++ b/fs/ceph/snap.c
@@ -430,8 +430,7 @@
* Caller must hold snap_rwsem for read (i.e., the realm topology won't
* change).
*/
-void ceph_queue_cap_snap(struct ceph_inode_info *ci,
- struct ceph_snap_context *snapc)
+void ceph_queue_cap_snap(struct ceph_inode_info *ci)
{
struct inode *inode = &ci->vfs_inode;
struct ceph_cap_snap *capsnap;
@@ -450,10 +449,11 @@
as no new writes are allowed to start when pending, so any
writes in progress now were started before the previous
cap_snap. lucky us. */
- dout("queue_cap_snap %p snapc %p seq %llu used %d"
- " already pending\n", inode, snapc, snapc->seq, used);
+ dout("queue_cap_snap %p already pending\n", inode);
kfree(capsnap);
} else if (ci->i_wrbuffer_ref_head || (used & CEPH_CAP_FILE_WR)) {
+ struct ceph_snap_context *snapc = ci->i_head_snapc;
+
igrab(inode);
atomic_set(&capsnap->nref, 1);
@@ -462,7 +462,6 @@
INIT_LIST_HEAD(&capsnap->flushing_item);
capsnap->follows = snapc->seq - 1;
- capsnap->context = ceph_get_snap_context(snapc);
capsnap->issued = __ceph_caps_issued(ci, NULL);
capsnap->dirty = __ceph_caps_dirty(ci);
@@ -479,7 +478,7 @@
snapshot. */
capsnap->dirty_pages = ci->i_wrbuffer_ref_head;
ci->i_wrbuffer_ref_head = 0;
- ceph_put_snap_context(ci->i_head_snapc);
+ capsnap->context = snapc;
ci->i_head_snapc = NULL;
list_add_tail(&capsnap->ci_item, &ci->i_cap_snaps);
@@ -603,7 +602,7 @@
if (lastinode)
iput(lastinode);
lastinode = inode;
- ceph_queue_cap_snap(ci, realm->cached_context);
+ ceph_queue_cap_snap(ci);
spin_lock(&realm->inodes_with_caps_lock);
}
spin_unlock(&realm->inodes_with_caps_lock);
@@ -825,8 +824,7 @@
spin_unlock(&realm->inodes_with_caps_lock);
spin_unlock(&inode->i_lock);
- ceph_queue_cap_snap(ci,
- ci->i_snap_realm->cached_context);
+ ceph_queue_cap_snap(ci);
iput(inode);
continue;