diff options
| author | Sachin Prabhu <sprabhu@redhat.com> | 2012-07-11 12:28:05 +0100 |
|---|---|---|
| committer | Steve French <smfrench@gmail.com> | 2012-07-16 23:57:02 -0500 |
| commit | ffc61ccbb96809df8d97ed609ac86b509eaf9056 (patch) | |
| tree | 6f97d985c640d7881aeb6ae888359e1c73213a1a /fs/cifs | |
| parent | 055c9fa8874fa7261eec7a268366565db84af474 (diff) | |
| download | linux-ffc61ccbb96809df8d97ed609ac86b509eaf9056.tar.bz2 | |
Initialise mid_q_entry before putting it on the pending queue
A user reported a crash in cifs_demultiplex_thread() caused by an
incorrectly set mid_q_entry->callback() function. It appears that the
callback assignment made in cifs_call_async() was not flushed back to
memory suggesting that a memory barrier was required here. Changing the
code to make sure that the mid_q_entry structure was completely
initialised before it was added to the pending queue fixes the problem.
Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Diffstat (limited to 'fs/cifs')
| -rw-r--r-- | fs/cifs/transport.c | 26 |
1 files changed, 14 insertions, 12 deletions
diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c index 3097ee58fd7d..f25d4ea14be4 100644 --- a/fs/cifs/transport.c +++ b/fs/cifs/transport.c @@ -365,16 +365,14 @@ cifs_setup_async_request(struct TCP_Server_Info *server, struct kvec *iov, if (mid == NULL) return -ENOMEM; - /* put it on the pending_mid_q */ - spin_lock(&GlobalMid_Lock); - list_add_tail(&mid->qhead, &server->pending_mid_q); - spin_unlock(&GlobalMid_Lock); - rc = cifs_sign_smb2(iov, nvec, server, &mid->sequence_number); - if (rc) - delete_mid(mid); + if (rc) { + DeleteMidQEntry(mid); + return rc; + } + *ret_mid = mid; - return rc; + return 0; } /* @@ -407,17 +405,21 @@ cifs_call_async(struct TCP_Server_Info *server, struct kvec *iov, mid->callback_data = cbdata; mid->mid_state = MID_REQUEST_SUBMITTED; + /* put it on the pending_mid_q */ + spin_lock(&GlobalMid_Lock); + list_add_tail(&mid->qhead, &server->pending_mid_q); + spin_unlock(&GlobalMid_Lock); + + cifs_in_send_inc(server); rc = smb_sendv(server, iov, nvec); cifs_in_send_dec(server); cifs_save_when_sent(mid); mutex_unlock(&server->srv_mutex); - if (rc) - goto out_err; + if (rc == 0) + return 0; - return rc; -out_err: delete_mid(mid); add_credits(server, 1); wake_up(&server->request_q); |