From b828b4bf29d10a3e505a76a39c4daea969e19dc9 Mon Sep 17 00:00:00 2001 From: Viacheslav Dubeyko Date: Mon, 2 Jun 2025 11:49:56 -0700 Subject: [PATCH] ceph: fix variable dereferenced before check in ceph_umount_begin() smatch warnings: fs/ceph/super.c:1042 ceph_umount_begin() warn: variable dereferenced before check 'fsc' (see line 1041) vim +/fsc +1042 fs/ceph/super.c void ceph_umount_begin(struct super_block *sb) { struct ceph_fs_client *fsc = ceph_sb_to_fs_client(sb); doutc(fsc->client, "starting forced umount\n"); ^^^^^^^^^^^ Dereferenced if (!fsc) ^^^^ Checked too late. return; fsc->mount_state = CEPH_MOUNT_SHUTDOWN; __ceph_umount_begin(fsc); } The VFS guarantees that the superblock is still alive when it calls into ceph via ->umount_begin(). Finally, we don't need to check the fsc and it should be valid. This patch simply removes the fsc check. Reported-by: kernel test robot Reported-by: Dan Carpenter Closes: https://lore.kernel.org/r/202503280852.YDB3pxUY-lkp@intel.com/ Signed-off-by: Viacheslav Dubeyko Reviewed by: Alex Markuze Signed-off-by: Ilya Dryomov --- fs/ceph/super.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/fs/ceph/super.c b/fs/ceph/super.c index fc4cab8b7b77..2b8438d8a324 100644 --- a/fs/ceph/super.c +++ b/fs/ceph/super.c @@ -1033,8 +1033,7 @@ void ceph_umount_begin(struct super_block *sb) struct ceph_fs_client *fsc = ceph_sb_to_fs_client(sb); doutc(fsc->client, "starting forced umount\n"); - if (!fsc) - return; + fsc->mount_state = CEPH_MOUNT_SHUTDOWN; __ceph_umount_begin(fsc); } -- 2.25.1