On 5/6/23 15:13, Dan Carpenter wrote:
On Sat, May 06, 2023 at 09:32:30AM +0800, Xiubo Li wrote:
Hi Dan,
On 5/5/23 17:21, Dan Carpenter wrote:
Hello Xiubo Li,
The patch aaf67de78807: "ceph: fix potential use-after-free bug when
trimming caps" from Apr 19, 2023, leads to the following Smatch
static checker warning:
fs/ceph/mds_client.c:3968 reconnect_caps_cb()
warn: missing error code here? '__get_cap_for_mds()' failed. 'err' = '0'
fs/ceph/mds_client.c
3933 static int reconnect_caps_cb(struct inode *inode, int mds, void *arg)
3934 {
3935 union {
3936 struct ceph_mds_cap_reconnect v2;
3937 struct ceph_mds_cap_reconnect_v1 v1;
3938 } rec;
3939 struct ceph_inode_info *ci = ceph_inode(inode);
3940 struct ceph_reconnect_state *recon_state = arg;
3941 struct ceph_pagelist *pagelist = recon_state->pagelist;
3942 struct dentry *dentry;
3943 struct ceph_cap *cap;
3944 char *path;
3945 int pathlen = 0, err = 0;
3946 u64 pathbase;
3947 u64 snap_follows;
3948
3949 dentry = d_find_primary(inode);
3950 if (dentry) {
3951 /* set pathbase to parent dir when msg_version >= 2 */
3952 path = ceph_mdsc_build_path(dentry, &pathlen, &pathbase,
3953 recon_state->msg_version >= 2);
3954 dput(dentry);
3955 if (IS_ERR(path)) {
3956 err = PTR_ERR(path);
3957 goto out_err;
3958 }
3959 } else {
3960 path = NULL;
3961 pathbase = 0;
3962 }
3963
3964 spin_lock(&ci->i_ceph_lock);
3965 cap = __get_cap_for_mds(ci, mds);
3966 if (!cap) {
3967 spin_unlock(&ci->i_ceph_lock);
--> 3968 goto out_err;
Set an error code?
This was intended, the 'err' was initialized as '0' in line 3945.
It's no harm to skip this _cb() for current cap, so just succeeds it.
Smatch considers it intentional of the "ret = 0;" assignment is within
4 or 5 (I forget) lines of the goto. Otherwise adding a comment would
help reviewers.
Yeah, I will revise this to dismiss the warning.
Thanks
- Xiubo
regards,
dan carpenter
