Commit ddf83afb authored by Ronnie Sahlberg's avatar Ronnie Sahlberg Committed by Steve French
Browse files

cifs: add a warning if we try to to dequeue a deleted mid 



cifs_delete_mid() is called once we are finished handling a mid and we
expect no more work done on this mid.

Needed to fix recent commit:
commit 730928c8
("cifs: update smb2_queryfs() to use compounding")

Add a warning if someone tries to dequeue a mid that has already been
flagged to be deleted.
Also change list_del() to list_del_init() so that if we have similar bugs
resurface in the future we will not oops.

Signed-off-by: default avatarRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
Reviewed-by: default avatarPavel Shilovsky <pshilov@microsoft.com>
parent 0595751f

fs/cifs/cifsglob.h

+1 −0
Original line number Diff line number Diff line
@@ -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 */

fs/cifs/connect.c

+9 −1
Original line number Diff line number Diff line
@@ -659,6 +659,14 @@ dequeue_mid(struct mid_q_entry *mid, bool malformed) 
		mid->mid_state = MID_RESPONSE_RECEIVED;

	else

		mid->mid_state = MID_RESPONSE_MALFORMED;

	/*

	 * 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);

}

fs/cifs/transport.c

+2 −1
Original line number Diff line number Diff line
@@ -142,7 +142,8 @@ void 
cifs_delete_mid(struct mid_q_entry *mid)

{

	spin_lock(&GlobalMid_Lock);

	list_del(&mid->qhead);

	list_del_init(&mid->qhead);

	mid->mid_flags |= MID_DELETED;

	spin_unlock(&GlobalMid_Lock);



	DeleteMidQEntry(mid);

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