cifs_delete_mid() is called once we are finished handling a mid and we
expect no more work done on this mid.
Add a warning if someone tries to dequeue a mid that has already been
flagged to be deleted.
Signed-off-by: Ronnie Sahlberg <lsahlber@xxxxxxxxxx>
---
fs/cifs/cifsglob.h | 1 +
fs/cifs/connect.c | 10 +++++++++-
fs/cifs/transport.c | 1 +
3 files changed, 11 insertions(+), 1 deletion(-)
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 0c9ab62c3df4..9dcaed031843 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -1553,6 +1553,7 @@ static inline void free_dfs_info_array(struct dfs_info3_param *param,
/* Flags */
#define MID_WAIT_CANCELLED 1 /* Cancelled while waiting for response */
+#define MID_DELETED 2 /* Mid has been dequeued/deleted */
/* Types of response buffer returned from SendReceive2 */
#define CIFS_NO_BUFFER 0 /* Response buffer not returned */
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index c832a8a1970a..c67ff7d2b201 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -659,7 +659,15 @@ dequeue_mid(struct mid_q_entry *mid, bool malformed)
mid->mid_state = MID_RESPONSE_RECEIVED;
else
mid->mid_state = MID_RESPONSE_MALFORMED;
- list_del_init(&mid->qhead);
+ /*
+ * Trying to handle/dequeue a mid after the send_recv()
+ * function has finished processing it is a bug.
+ */
+ if (mid->mid_flags & MID_DELETED)
+ printk_once(KERN_WARNING
+ "trying to dequeue a deleted mid\n");
+ else
+ list_del_init(&mid->qhead);
spin_unlock(&GlobalMid_Lock);
}
diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index 78f96fa3d7d9..9e3a1e87ae1c 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -143,6 +143,7 @@ cifs_delete_mid(struct mid_q_entry *mid)
{
spin_lock(&GlobalMid_Lock);
list_del(&mid->qhead);
+ mid->mid_flags |= MID_DELETED;
spin_unlock(&GlobalMid_Lock);
DeleteMidQEntry(mid);
--
2.13.3
