On Mon, Nov 22, 2010 at 2:31 PM, Jeff Layton <jlayton@xxxxxxxxxxxxxxx> wrote:
> The server->sequence_number is already protected by the srv_mutex. The
> GlobalMid_lock is unneeded here.
>
> Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
> ---
> fs/cifs/cifsencrypt.c | 6 ++----
> fs/cifs/cifsglob.h | 2 +-
> 2 files changed, 3 insertions(+), 5 deletions(-)
>
> diff --git a/fs/cifs/cifsencrypt.c b/fs/cifs/cifsencrypt.c
> index f856732..66f3d50 100644
> --- a/fs/cifs/cifsencrypt.c
> +++ b/fs/cifs/cifsencrypt.c
> @@ -72,6 +72,7 @@ static int cifs_calculate_signature(const struct smb_hdr *cifs_pdu,
> return 0;
> }
>
> +/* must be called with server->srv_mutex held */
> int cifs_sign_smb(struct smb_hdr *cifs_pdu, struct TCP_Server_Info *server,
> __u32 *pexpected_response_sequence_number)
> {
> @@ -84,14 +85,12 @@ int cifs_sign_smb(struct smb_hdr *cifs_pdu, struct TCP_Server_Info *server,
> if ((cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) == 0)
> return rc;
>
> - spin_lock(&GlobalMid_Lock);
> cifs_pdu->Signature.Sequence.SequenceNumber =
> cpu_to_le32(server->sequence_number);
> cifs_pdu->Signature.Sequence.Reserved = 0;
>
> *pexpected_response_sequence_number = server->sequence_number++;
> server->sequence_number++;
> - spin_unlock(&GlobalMid_Lock);
>
> rc = cifs_calculate_signature(cifs_pdu, server, smb_signature);
> if (rc)
> @@ -149,6 +148,7 @@ static int cifs_calc_signature2(const struct kvec *iov, int n_vec,
> return rc;
> }
>
> +/* must be called with server->srv_mutex held */
> int cifs_sign_smb2(struct kvec *iov, int n_vec, struct TCP_Server_Info *server,
> __u32 *pexpected_response_sequence_number)
> {
> @@ -162,14 +162,12 @@ int cifs_sign_smb2(struct kvec *iov, int n_vec, struct TCP_Server_Info *server,
> if ((cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) == 0)
> return rc;
>
> - spin_lock(&GlobalMid_Lock);
> cifs_pdu->Signature.Sequence.SequenceNumber =
> cpu_to_le32(server->sequence_number);
> cifs_pdu->Signature.Sequence.Reserved = 0;
>
> *pexpected_response_sequence_number = server->sequence_number++;
> server->sequence_number++;
> - spin_unlock(&GlobalMid_Lock);
>
> rc = cifs_calc_signature2(iov, n_vec, server, smb_signature);
> if (rc)
> diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
> index a8d9f32..bba731c 100644
> --- a/fs/cifs/cifsglob.h
> +++ b/fs/cifs/cifsglob.h
> @@ -200,7 +200,7 @@ struct TCP_Server_Info {
> char cryptkey[CIFS_CRYPTO_KEY_SIZE]; /* used by ntlm, ntlmv2 etc */
> /* 16th byte of RFC1001 workstation name is always null */
> char workstation_RFC1001_name[RFC1001_NAME_LEN_WITH_NULL];
> - __u32 sequence_number; /* needed for CIFS PDU signature */
> + __u32 sequence_number; /* for signing, protected by srv_mutex */
> struct session_key session_key;
> unsigned long lstrp; /* when we got last response from this server */
> u16 dialect; /* dialect index that server chose */
> --
> 1.7.3.2
>
> --
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>
Looks correct. Two less contenders for global mid lock.
Reviewed-by: Shirish Pargaonkar <shirishpargaonkar@xxxxxxxxx>
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