gfs2: Don't call cancel_delayed_work_sync from within delete work function

Right now, we can end up calling cancel_delayed_work_sync from within
delete_work_func via gfs2_lookup_by_inum -> gfs2_inode_lookup ->
gfs2_cancel_delete_work.  When that happens, it will result in a
deadlock.  Instead, gfs2_inode_lookup should skip the call to
gfs2_cancel_delete_work when called from delete_work_func (blktype ==
GFS2_BLKST_UNLINKED).

Reported-by: Alexander Ahring Oder Aring <aahringo@redhat.com>
Fixes: a0e3cc65fa29 ("gfs2: Turn gl_delete into a delayed work")
Cc: stable@vger.kernel.org # v5.8+
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index 6774865f5b5b5c5f8b468d85abc9cd4cb912afa4..077ccb1b3ccc6ea59c4a4963c96e39af6a4cc07a 100644 (file)
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -180,7 +180,8 @@ struct inode *gfs2_inode_lookup(struct super_block *sb, unsigned int type,
                error = gfs2_glock_nq_init(io_gl, LM_ST_SHARED, GL_EXACT, &ip->i_iopen_gh);
                if (unlikely(error))
                        goto fail;
-               gfs2_cancel_delete_work(ip->i_iopen_gh.gh_gl);
+               if (blktype != GFS2_BLKST_UNLINKED)
+                       gfs2_cancel_delete_work(ip->i_iopen_gh.gh_gl);
                glock_set_object(ip->i_iopen_gh.gh_gl, ip);
                gfs2_glock_put(io_gl);
                io_gl = NULL;