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[CIFS] fix for incorrect session reconnects

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cifs reconnect could end up happening incorrectly due to
the small initial tcp recvmsg response. When the socket
was within three bytes of being full and the recvmsg
returned only 1 to 3 bytes of the initial 4 byte
read of the RFC1001 length field. Fortunately this
seems to be less common on more current kernels, but
this fixes it so cifs tries to retrieve all 4 bytes
of the initial tcp read.

Signed-off-by: Shirish Pargoankar <shirishp@us.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
This commit is contained in:
Steve French 2007-08-30 21:13:31 +00:00
parent 8594c15ad2
commit f01d5e14e7
1 changed files with 7 additions and 6 deletions
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13
fs/cifs/connect.c
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@ -400,9 +400,11 @@ cifs_demultiplex_thread(struct TCP_Server_Info *server)
iov.iov_len = 4; iov.iov_len = 4;
smb_msg.msg_control = NULL; smb_msg.msg_control = NULL;
smb_msg.msg_controllen = 0; smb_msg.msg_controllen = 0;
pdu_length = 4; /* enough to get RFC1001 header */
incomplete_rcv:
length = length =
kernel_recvmsg(csocket, &smb_msg, kernel_recvmsg(csocket, &smb_msg,
&iov, 1, 4, 0 /* BB see socket.h flags */); &iov, 1, pdu_length, 0 /* BB other flags? */);
if ( kthread_should_stop() ) { if ( kthread_should_stop() ) {
break; break;
@ -437,13 +439,12 @@ cifs_demultiplex_thread(struct TCP_Server_Info *server)
wake_up(&server->response_q); wake_up(&server->response_q);
continue; continue;
} else if (length < 4) { } else if (length < 4) {
cFYI(1, cFYI(1, ("less than four bytes received (%d bytes)",
("Frame under four bytes received (%d bytes long)",
length)); length));
pdu_length -= length;
cifs_reconnect(server); cifs_reconnect(server);
csocket = server->ssocket; msleep(1);
wake_up(&server->response_q); goto incomplete_rcv;
continue;
} }
/* The right amount was read from socket - 4 bytes */ /* The right amount was read from socket - 4 bytes */