From b493ad718b1f0357394d2cdecbf00a44a36fa085 Mon Sep 17 00:00:00 2001 From: Xiubo Li Date: Fri, 17 Nov 2023 13:26:18 +0800 Subject: [PATCH] ceph: fix deadlock or deadcode of misusing dget() The lock order is incorrect between denty and its parent, we should always make sure that the parent get the lock first. But since this deadcode is never used and the parent dir will always be set from the callers, let's just remove it. Link: https://lore.kernel.org/r/20231116081919.GZ1957730@ZenIV Reported-by: Al Viro Signed-off-by: Xiubo Li Reviewed-by: Jeff Layton Signed-off-by: Ilya Dryomov --- fs/ceph/caps.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c index 2c0b8dc3dd0d80..9c02f328c966cb 100644 --- a/fs/ceph/caps.c +++ b/fs/ceph/caps.c @@ -4887,13 +4887,15 @@ int ceph_encode_dentry_release(void **p, struct dentry *dentry, struct inode *dir, int mds, int drop, int unless) { - struct dentry *parent = NULL; struct ceph_mds_request_release *rel = *p; struct ceph_dentry_info *di = ceph_dentry(dentry); struct ceph_client *cl; int force = 0; int ret; + /* This shouldn't happen */ + BUG_ON(!dir); + /* * force an record for the directory caps if we have a dentry lease. * this is racy (can't take i_ceph_lock and d_lock together), but it @@ -4903,14 +4905,9 @@ int ceph_encode_dentry_release(void **p, struct dentry *dentry, spin_lock(&dentry->d_lock); if (di->lease_session && di->lease_session->s_mds == mds) force = 1; - if (!dir) { - parent = dget(dentry->d_parent); - dir = d_inode(parent); - } spin_unlock(&dentry->d_lock); ret = ceph_encode_inode_release(p, dir, mds, drop, unless, force); - dput(parent); cl = ceph_inode_to_client(dir); spin_lock(&dentry->d_lock);