[Cluster-devel] [PATCH 09/11] gfs2: Check inode generation number in delete_work_func

[Andreas Gruenbacher]

In delete_work_func, if the iopen glock still has an inode attached,
limit the inode lookup to that specific generation number: in the likely
case that the inode was deleted on the node on which the inode's link
count dropped to zero, we can skip verifying the on-disk block type and
reading in the inode.  The same applies if another node that had the
inode open as well managed to delete the inode before us.

Signed-off-by: Andreas Gruenbacher <agruenba at redhat.com>
---
 fs/gfs2/glock.c  | 4 +++-
 fs/gfs2/incore.h | 5 ++++-
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 58da551ecb5c..1f906a3281b0 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -717,6 +717,7 @@ static bool gfs2_try_evict(struct gfs2_glock *gl)
 		ip = NULL;
 	spin_unlock(&gl->gl_lockref.lock);
 	if (ip) {
+		gl->gl_no_formal_ino = ip->i_no_formal_ino;
 		set_bit(GIF_DEFERRED_DELETE, &ip->i_flags);
 		d_prune_aliases(&ip->i_inode);
 		iput(&ip->i_inode);
@@ -762,7 +763,8 @@ static void delete_work_func(struct work_struct *work)
 		}
 	}
 
-	inode = gfs2_lookup_by_inum(sdp, no_addr, 0, GFS2_BLKST_UNLINKED);
+	inode = gfs2_lookup_by_inum(sdp, no_addr, gl->gl_no_formal_ino,
+				    GFS2_BLKST_UNLINKED);
 	if (!IS_ERR_OR_NULL(inode)) {
 		d_prune_aliases(inode);
 		iput(inode);
diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index aecdde83c22c..f7a770a12107 100644
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -376,7 +376,10 @@ struct gfs2_glock {
 	struct delayed_work gl_work;
 	union {
 		/* For iopen glocks only */
-		struct delayed_work gl_delete;
+		struct {
+			struct delayed_work gl_delete;
+			u64 gl_no_formal_ino;
+		};
 		/* For rgrp glocks only */
 		struct {
 			loff_t start;
-- 
2.20.1