gfs2: Give up the iopen glock on contention

When there's contention on the iopen glock, it means that the link count
of the corresponding inode has dropped to zero on a remote node which is
now trying to delete the inode.  In that case, try to evict the inode so
that the iopen glock will be released, which will allow the remote node
to do its job.

When the inode is still open locally, the inode's reference count won't
drop to zero and so we'll keep holding the inode and its iopen glock.
The remote node will time out its request to grab the iopen glock, and
when the inode is finally closed locally, we'll try to delete it
ourself.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

1 files changed, 5 insertions, 2 deletions

diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c
index 71218a6fd9b4..7d8caf169efd 100644
--- a/fs/gfs2/super.c
+++ b/fs/gfs2/super.c
@@ -1299,9 +1299,12 @@ static void gfs2_evict_inode(struct inode *inode)
 	if (test_bit(GIF_ALLOC_FAILED, &ip->i_flags)) {
 		BUG_ON(!gfs2_glock_is_locked_by_me(ip->i_gl));
 		gfs2_holder_mark_uninitialized(&gh);
-		goto alloc_failed;
+		goto out_delete;
 	}
 
+	if (test_bit(GIF_DEFERRED_DELETE, &ip->i_flags))
+		goto out;
+
 	/* Deletes should never happen under memory pressure anymore.  */
 	if (WARN_ON_ONCE(current->flags & PF_MEMALLOC))
 		goto out;
@@ -1333,7 +1336,7 @@ static void gfs2_evict_inode(struct inode *inode)
 	if (inode->i_nlink)
 		goto out_truncate;
 
-alloc_failed:
+out_delete:
 	if (gfs2_holder_initialized(&ip->i_iopen_gh) &&
 	    test_bit(HIF_HOLDER, &ip->i_iopen_gh.gh_iflags)) {
 		ip->i_iopen_gh.gh_flags |= GL_NOCACHE;