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authorPavel Shilovsky <piastryyy@gmail.com>2011-08-01 13:19:41 +0400
committerSteve French <sfrench@us.ibm.com>2011-08-01 12:49:34 +0000
commite7015fb1c508fe9b8c97707755ce08f5ace0afb9 (patch)
tree7c084839f5e163c9099c8c4f88422f97a048748e /fs
parent3d9c2472a53ee1d26de9803899037aeeb44ccef1 (diff)
CIFS: Simplify socket reading in demultiplex thread
Move reading to separate function and remove csocket variable. Also change semantic in a little: goto incomplete_rcv only when we get -EAGAIN (or a familiar error) while reading rfc1002 header. In this case we don't check for echo timeout when we don't get whole header at once, as it was before. Reviewed-and-Tested-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Pavel Shilovsky <piastryyy@gmail.com> Signed-off-by: Steve French <sfrench@us.ibm.com>
Diffstat (limited to 'fs')
-rw-r--r--fs/cifs/connect.c154
1 files changed, 71 insertions, 83 deletions
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 217d36587185..a2e9fcf4a996 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -359,6 +359,64 @@ allocate_buffers(char **bigbuf, char **smallbuf, unsigned int size,
}
static int
+read_from_socket(struct TCP_Server_Info *server, struct msghdr *smb_msg,
+ struct kvec *iov, unsigned int to_read,
+ unsigned int *ptotal_read, bool is_header_read)
+{
+ int length, rc = 0;
+ unsigned int total_read;
+ char *buf = iov->iov_base;
+
+ for (total_read = 0; total_read < to_read; total_read += length) {
+ length = kernel_recvmsg(server->ssocket, smb_msg, iov, 1,
+ to_read - total_read, 0);
+ if (server->tcpStatus == CifsExiting) {
+ /* then will exit */
+ rc = 2;
+ break;
+ } else if (server->tcpStatus == CifsNeedReconnect) {
+ cifs_reconnect(server);
+ /* Reconnect wakes up rspns q */
+ /* Now we will reread sock */
+ rc = 1;
+ break;
+ } else if (length == -ERESTARTSYS ||
+ length == -EAGAIN ||
+ length == -EINTR) {
+ /*
+ * Minimum sleep to prevent looping, allowing socket
+ * to clear and app threads to set tcpStatus
+ * CifsNeedReconnect if server hung.
+ */
+ usleep_range(1000, 2000);
+ length = 0;
+ if (!is_header_read)
+ continue;
+ /* Special handling for header read */
+ if (total_read) {
+ iov->iov_base = (to_read - total_read) +
+ buf;
+ iov->iov_len = to_read - total_read;
+ smb_msg->msg_control = NULL;
+ smb_msg->msg_controllen = 0;
+ rc = 3;
+ } else
+ rc = 1;
+ break;
+ } else if (length <= 0) {
+ cERROR(1, "Received no data, expecting %d",
+ to_read - total_read);
+ cifs_reconnect(server);
+ rc = 1;
+ break;
+ }
+ }
+
+ *ptotal_read = total_read;
+ return rc;
+}
+
+static int
cifs_demultiplex_thread(void *p)
{
int length;
@@ -368,14 +426,13 @@ cifs_demultiplex_thread(void *p)
struct smb_hdr *smb_buffer = NULL;
struct msghdr smb_msg;
struct kvec iov;
- struct socket *csocket = server->ssocket;
struct list_head *tmp, *tmp2;
struct task_struct *task_to_wake = NULL;
struct mid_q_entry *mid_entry;
char temp;
bool isLargeBuf = false;
bool isMultiRsp;
- int reconnect;
+ int rc;
current->flags |= PF_MEMALLOC;
cFYI(1, "Demultiplex PID: %d", task_pid_nr(current));
@@ -412,51 +469,18 @@ incomplete_rcv:
"Reconnecting...", server->hostname,
(echo_retries * SMB_ECHO_INTERVAL / HZ));
cifs_reconnect(server);
- csocket = server->ssocket;
wake_up(&server->response_q);
continue;
}
- length =
- kernel_recvmsg(csocket, &smb_msg,
- &iov, 1, pdu_length, 0 /* BB other flags? */);
-
- if (server->tcpStatus == CifsExiting) {
+ rc = read_from_socket(server, &smb_msg, &iov, pdu_length,
+ &total_read, true /* header read */);
+ if (rc == 3)
+ goto incomplete_rcv;
+ else if (rc == 2)
break;
- } else if (server->tcpStatus == CifsNeedReconnect) {
- cFYI(1, "Reconnect after server stopped responding");
- cifs_reconnect(server);
- cFYI(1, "call to reconnect done");
- csocket = server->ssocket;
- continue;
- } else if (length == -ERESTARTSYS ||
- length == -EAGAIN ||
- length == -EINTR) {
- msleep(1); /* minimum sleep to prevent looping
- allowing socket to clear and app threads to set
- tcpStatus CifsNeedReconnect if server hung */
- if (pdu_length < 4) {
- iov.iov_base = (4 - pdu_length) + buf;
- iov.iov_len = pdu_length;
- smb_msg.msg_control = NULL;
- smb_msg.msg_controllen = 0;
- goto incomplete_rcv;
- } else
- continue;
- } else if (length <= 0) {
- cFYI(1, "Reconnect after unexpected peek error %d",
- length);
- cifs_reconnect(server);
- csocket = server->ssocket;
- wake_up(&server->response_q);
+ else if (rc == 1)
continue;
- } else if (length < pdu_length) {
- cFYI(1, "requested %d bytes but only got %d bytes",
- pdu_length, length);
- pdu_length -= length;
- msleep(1);
- goto incomplete_rcv;
- }
/* The right amount was read from socket - 4 bytes */
/* so we can now interpret the length field */
@@ -493,14 +517,12 @@ incomplete_rcv:
cifs_set_port((struct sockaddr *)
&server->dstaddr, CIFS_PORT);
cifs_reconnect(server);
- csocket = server->ssocket;
wake_up(&server->response_q);
continue;
} else if (temp != (char) 0) {
cERROR(1, "Unknown RFC 1002 frame");
cifs_dump_mem(" Received Data: ", buf, length);
cifs_reconnect(server);
- csocket = server->ssocket;
continue;
}
@@ -510,59 +532,25 @@ incomplete_rcv:
cERROR(1, "Invalid size SMB length %d pdu_length %d",
length, pdu_length+4);
cifs_reconnect(server);
- csocket = server->ssocket;
wake_up(&server->response_q);
continue;
}
/* else length ok */
- reconnect = 0;
-
if (pdu_length > MAX_CIFS_SMALL_BUFFER_SIZE - 4) {
isLargeBuf = true;
memcpy(bigbuf, smallbuf, 4);
smb_buffer = (struct smb_hdr *)bigbuf;
buf = bigbuf;
}
- length = 0;
+
iov.iov_base = 4 + buf;
iov.iov_len = pdu_length;
- for (total_read = 0; total_read < pdu_length;
- total_read += length) {
- length = kernel_recvmsg(csocket, &smb_msg, &iov, 1,
- pdu_length - total_read, 0);
- if (server->tcpStatus == CifsExiting) {
- /* then will exit */
- reconnect = 2;
- break;
- } else if (server->tcpStatus == CifsNeedReconnect) {
- cifs_reconnect(server);
- csocket = server->ssocket;
- /* Reconnect wakes up rspns q */
- /* Now we will reread sock */
- reconnect = 1;
- break;
- } else if (length == -ERESTARTSYS ||
- length == -EAGAIN ||
- length == -EINTR) {
- msleep(1); /* minimum sleep to prevent looping,
- allowing socket to clear and app
- threads to set tcpStatus
- CifsNeedReconnect if server hung*/
- length = 0;
- continue;
- } else if (length <= 0) {
- cERROR(1, "Received no data, expecting %d",
- pdu_length - total_read);
- cifs_reconnect(server);
- csocket = server->ssocket;
- reconnect = 1;
- break;
- }
- }
- if (reconnect == 2)
+ rc = read_from_socket(server, &smb_msg, &iov, pdu_length,
+ &total_read, false);
+ if (rc == 2)
break;
- else if (reconnect == 1)
+ else if (rc == 1)
continue;
total_read += 4; /* account for rfc1002 hdr */
@@ -705,7 +693,7 @@ multi_t2_fnd:
msleep(125);
if (server->ssocket) {
- sock_release(csocket);
+ sock_release(server->ssocket);
server->ssocket = NULL;
}
/* buffer usually freed in free_mid - need to free it here on exit */