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cifs: mangle existing header for SMB_COM_NT_CANCEL

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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 <piastryyy@gmail.com>
Reviewed-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
This commit is contained in:
Jeff Layton 2011-01-11 07:24:24 -05:00 committed by Steve French
parent 7749981ec3
commit 76dcc26f1d
1 changed files with 38 additions and 25 deletions
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63
fs/cifs/transport.c
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@ -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 @@ out:
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;