From 766fdbb57fdb1e53bc34c431103e95383d7f13ba Mon Sep 17 00:00:00 2001
From: Jeff Layton <jlayton@redhat.com>
Date: Tue, 11 Jan 2011 07:24:21 -0500
Subject: [PATCH] cifs: add ability to send an echo request
Reviewed-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
---
fs/cifs/cifspdu.h | 15 +++++++++++++++
fs/cifs/cifsproto.h | 2 ++
fs/cifs/cifssmb.c | 47 +++++++++++++++++++++++++++++++++++++++++++++
fs/cifs/transport.c | 2 +-
4 files changed, 65 insertions(+), 1 deletion(-)
diff --git a/fs/cifs/cifspdu.h b/fs/cifs/cifspdu.h
index de36b09763a84e..ea205b4fcad25e 100644
--- a/fs/cifs/cifspdu.h
+++ b/fs/cifs/cifspdu.h
@@ -50,6 +50,7 @@
#define SMB_COM_SETATTR 0x09 /* trivial response */
#define SMB_COM_LOCKING_ANDX 0x24 /* trivial response */
#define SMB_COM_COPY 0x29 /* trivial rsp, fail filename ignrd*/
+#define SMB_COM_ECHO 0x2B /* echo request */
#define SMB_COM_OPEN_ANDX 0x2D /* Legacy open for old servers */
#define SMB_COM_READ_ANDX 0x2E
#define SMB_COM_WRITE_ANDX 0x2F
@@ -760,6 +761,20 @@ typedef struct smb_com_tconx_rsp_ext {
*
*/
+typedef struct smb_com_echo_req {
+ struct smb_hdr hdr;
+ __le16 EchoCount;
+ __le16 ByteCount;
+ char Data[1];
+} __attribute__((packed)) ECHO_REQ;
+
+typedef struct smb_com_echo_rsp {
+ struct smb_hdr hdr;
+ __le16 SequenceNumber;
+ __le16 ByteCount;
+ char Data[1];
+} __attribute__((packed)) ECHO_RSP;
+
typedef struct smb_com_logoff_andx_req {
struct smb_hdr hdr; /* wct = 2 */
__u8 AndXCommand;
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index 7f2988bb892988..982895fa76152b 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -63,6 +63,7 @@ extern char *cifs_compose_mount_options(const char *sb_mountdata,
/* extern void renew_parental_timestamps(struct dentry *direntry);*/
extern struct mid_q_entry *AllocMidQEntry(const struct smb_hdr *smb_buffer,
struct TCP_Server_Info *server);
+extern void DeleteMidQEntry(struct mid_q_entry *midEntry);
extern int cifs_call_async(struct TCP_Server_Info *server,
struct smb_hdr *in_buf, mid_callback_t *callback,
void *cbdata);
@@ -358,6 +359,7 @@ extern int CIFSSMBPosixLock(const int xid, struct cifsTconInfo *tcon,
const __u64 len, struct file_lock *,
const __u16 lock_type, const bool waitFlag);
extern int CIFSSMBTDis(const int xid, struct cifsTconInfo *tcon);
+extern int CIFSSMBEcho(struct TCP_Server_Info *server);
extern int CIFSSMBLogoff(const int xid, struct cifsSesInfo *ses);
extern struct cifsSesInfo *sesInfoAlloc(void);
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index 3652cc60314cee..54b9f5d8d1dbf9 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -706,6 +706,53 @@ CIFSSMBTDis(const int xid, struct cifsTconInfo *tcon)
return rc;
}
+/*
+ * This is a no-op for now. We're not really interested in the reply, but
+ * rather in the fact that the server sent one and that server->lstrp
+ * gets updated.
+ *
+ * FIXME: maybe we should consider checking that the reply matches request?
+ */
+static void
+cifs_echo_callback(struct mid_q_entry *mid)
+{
+ struct TCP_Server_Info *server = mid->callback_data;
+
+ DeleteMidQEntry(mid);
+ atomic_dec(&server->inFlight);
+ wake_up(&server->request_q);
+}
+
+int
+CIFSSMBEcho(struct TCP_Server_Info *server)
+{
+ ECHO_REQ *smb;
+ int rc = 0;
+
+ cFYI(1, "In echo request");
+
+ rc = small_smb_init(SMB_COM_ECHO, 0, NULL, (void **)&smb);
+ if (rc)
+ return rc;
+
+ /* set up echo request */
+ smb->hdr.Tid = cpu_to_le16(0xffff);
+ smb->hdr.WordCount = cpu_to_le16(1);
+ smb->EchoCount = cpu_to_le16(1);
+ smb->ByteCount = cpu_to_le16(1);
+ smb->Data[0] = 'a';
+ smb->hdr.smb_buf_length += 3;
+
+ rc = cifs_call_async(server, (struct smb_hdr *)smb,
+ cifs_echo_callback, server);
+ if (rc)
+ cFYI(1, "Echo request failed: %d", rc);
+
+ cifs_small_buf_release(smb);
+
+ return rc;
+}
+
int
CIFSSMBLogoff(const int xid, struct cifsSesInfo *ses)
{
diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index 166b65a3763e50..a0cef496051682 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -78,7 +78,7 @@ AllocMidQEntry(const struct smb_hdr *smb_buffer, struct TCP_Server_Info *server)
return temp;
}
-static void
+void
DeleteMidQEntry(struct mid_q_entry *midEntry)
{
#ifdef CONFIG_CIFS_STATS2
--
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