From 76dcc26f1d7f1c98c3f595379dcd9562f01bf38d Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Tue, 11 Jan 2011 07:24:24 -0500 Subject: [PATCH] cifs: mangle existing header for SMB_COM_NT_CANCEL The NT_CANCEL command looks just like the original command, except for a few small differences. The send_nt_cancel function however currently takes a tcon, which we don't have in SendReceive and SendReceive2. Instead of "respinning" the entire header for an NT_CANCEL, just mangle the existing header by replacing just the fields we need. This means we don't need a tcon and allows us to call it from other places. Reviewed-by: Pavel Shilovsky Reviewed-by: Suresh Jayaraman Signed-off-by: Jeff Layton Signed-off-by: Steve French --- fs/cifs/transport.c | 63 +++++++++++++++++++++++++++------------------ 1 file changed, 38 insertions(+), 25 deletions(-) diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c index fe92c4cb75f5..c8e2808cd5e6 100644 --- a/fs/cifs/transport.c +++ b/fs/cifs/transport.c @@ -464,6 +464,43 @@ sync_mid_result(struct mid_q_entry *mid, struct TCP_Server_Info *server) return rc; } +/* + * An NT cancel request header looks just like the original request except: + * + * The Command is SMB_COM_NT_CANCEL + * The WordCount is zeroed out + * The ByteCount is zeroed out + * + * This function mangles an existing request buffer into a + * SMB_COM_NT_CANCEL request and then sends it. + */ +static int +send_nt_cancel(struct TCP_Server_Info *server, struct smb_hdr *in_buf, + struct mid_q_entry *mid) +{ + int rc = 0; + + /* -4 for RFC1001 length and +2 for BCC field */ + in_buf->smb_buf_length = sizeof(struct smb_hdr) - 4 + 2; + in_buf->Command = SMB_COM_NT_CANCEL; + in_buf->WordCount = 0; + BCC_LE(in_buf) = 0; + + mutex_lock(&server->srv_mutex); + rc = cifs_sign_smb(in_buf, server, &mid->sequence_number); + if (rc) { + mutex_unlock(&server->srv_mutex); + return rc; + } + rc = smb_send(server, in_buf, in_buf->smb_buf_length); + mutex_unlock(&server->srv_mutex); + + cFYI(1, "issued NT_CANCEL for mid %u, rc = %d", + in_buf->Mid, rc); + + return rc; +} + int SendReceive2(const unsigned int xid, struct cifsSesInfo *ses, struct kvec *iov, int n_vec, int *pRespBufType /* ret */, @@ -753,29 +790,6 @@ SendReceive(const unsigned int xid, struct cifsSesInfo *ses, return rc; } -/* Send an NT_CANCEL SMB to cause the POSIX blocking lock to return. */ - -static int -send_nt_cancel(struct cifsTconInfo *tcon, struct smb_hdr *in_buf, - struct mid_q_entry *midQ) -{ - int rc = 0; - struct cifsSesInfo *ses = tcon->ses; - __u16 mid = in_buf->Mid; - - header_assemble(in_buf, SMB_COM_NT_CANCEL, tcon, 0); - in_buf->Mid = mid; - mutex_lock(&ses->server->srv_mutex); - rc = cifs_sign_smb(in_buf, ses->server, &midQ->sequence_number); - if (rc) { - mutex_unlock(&ses->server->srv_mutex); - return rc; - } - rc = smb_send(ses->server, in_buf, in_buf->smb_buf_length); - mutex_unlock(&ses->server->srv_mutex); - return rc; -} - /* We send a LOCKINGX_CANCEL_LOCK to cause the Windows blocking lock to return. */ @@ -890,8 +904,7 @@ SendReceiveBlockingLock(const unsigned int xid, struct cifsTconInfo *tcon, if (in_buf->Command == SMB_COM_TRANSACTION2) { /* POSIX lock. We send a NT_CANCEL SMB to cause the blocking lock to return. */ - - rc = send_nt_cancel(tcon, in_buf, midQ); + rc = send_nt_cancel(ses->server, in_buf, midQ); if (rc) { delete_mid(midQ); return rc;