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authorShyam Prasad N <sprasad@microsoft.com>2021-07-14 23:00:00 -0500
committerSteve French <stfrench@microsoft.com>2021-07-15 19:07:00 -0500
commit16dd9b8c31aee7ae074fa3ee36a797e9ba9f7e4f (patch)
treed1d3f47648bd38eb5e40c13ccc9013dc32314703
parent63f94e946fafcfc5080b4a4aec9770158268e4ee (diff)
cifs: added WARN_ON for all the count decrements
We have a few ref counters srv_count, ses_count and tc_count which we use for ref counting. Added a WARN_ON during the decrement of each of these counters to make sure that they don't go below their minimum values. Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
-rw-r--r--fs/cifs/connect.c9
-rw-r--r--fs/cifs/smb2ops.c2
2 files changed, 11 insertions, 0 deletions
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index a1e870232114..6b6c3e341b42 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -1295,6 +1295,9 @@ cifs_put_tcp_session(struct TCP_Server_Info *server, int from_reconnect)
return;
}
+ /* srv_count can never go negative */
+ WARN_ON(server->srv_count < 0);
+
put_net(cifs_net_ns(server));
list_del_init(&server->tcp_ses_list);
@@ -1654,6 +1657,9 @@ void cifs_put_smb_ses(struct cifs_ses *ses)
}
spin_unlock(&cifs_tcp_ses_lock);
+ /* ses_count can never go negative */
+ WARN_ON(ses->ses_count < 0);
+
spin_lock(&GlobalMid_Lock);
if (ses->status == CifsGood)
ses->status = CifsExiting;
@@ -2021,6 +2027,9 @@ cifs_put_tcon(struct cifs_tcon *tcon)
return;
}
+ /* tc_count can never go negative */
+ WARN_ON(tcon->tc_count < 0);
+
if (tcon->use_witness) {
int rc;
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 232d528df230..ba3c58e1f725 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -2910,6 +2910,8 @@ smb2_get_dfs_refer(const unsigned int xid, struct cifs_ses *ses,
/* ipc tcons are not refcounted */
spin_lock(&cifs_tcp_ses_lock);
tcon->tc_count--;
+ /* tc_count can never go negative */
+ WARN_ON(tcon->tc_count < 0);
spin_unlock(&cifs_tcp_ses_lock);
}
kfree(utf16_path);