libceph: fix socket read error handling
If we get EAGAIN when trying to read from the socket, it is not an error.
Return 0 from the helper in this case to simplify the error handling cases
in the caller (indirectly, try_read).
Fix try_read to pass any error to it's caller (con_work) instead of almost
always returning 0. This let's us respond to things like socket
disconnects.
Signed-off-by: Sage Weil <sage@newdream.net>
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index dff633d..d95576d 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -252,8 +252,12 @@
{
struct kvec iov = {buf, len};
struct msghdr msg = { .msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL };
+ int r;
- return kernel_recvmsg(sock, &msg, &iov, 1, len, msg.msg_flags);
+ r = kernel_recvmsg(sock, &msg, &iov, 1, len, msg.msg_flags);
+ if (r == -EAGAIN)
+ r = 0;
+ return r;
}
/*
@@ -1821,19 +1825,17 @@
dout("try_read connecting\n");
ret = read_partial_banner(con);
if (ret <= 0)
- goto done;
- if (process_banner(con) < 0) {
- ret = -1;
goto out;
- }
+ ret = process_banner(con);
+ if (ret < 0)
+ goto out;
}
ret = read_partial_connect(con);
if (ret <= 0)
- goto done;
- if (process_connect(con) < 0) {
- ret = -1;
goto out;
- }
+ ret = process_connect(con);
+ if (ret < 0)
+ goto out;
goto more;
}
@@ -1848,7 +1850,7 @@
dout("skipping %d / %d bytes\n", skip, -con->in_base_pos);
ret = ceph_tcp_recvmsg(con->sock, buf, skip);
if (ret <= 0)
- goto done;
+ goto out;
con->in_base_pos += ret;
if (con->in_base_pos)
goto more;
@@ -1859,7 +1861,7 @@
*/
ret = ceph_tcp_recvmsg(con->sock, &con->in_tag, 1);
if (ret <= 0)
- goto done;
+ goto out;
dout("try_read got tag %d\n", (int)con->in_tag);
switch (con->in_tag) {
case CEPH_MSGR_TAG_MSG:
@@ -1870,7 +1872,7 @@
break;
case CEPH_MSGR_TAG_CLOSE:
set_bit(CLOSED, &con->state); /* fixme */
- goto done;
+ goto out;
default:
goto bad_tag;
}
@@ -1882,13 +1884,12 @@
case -EBADMSG:
con->error_msg = "bad crc";
ret = -EIO;
- goto out;
+ break;
case -EIO:
con->error_msg = "io error";
- goto out;
- default:
- goto done;
+ break;
}
+ goto out;
}
if (con->in_tag == CEPH_MSGR_TAG_READY)
goto more;
@@ -1898,15 +1899,13 @@
if (con->in_tag == CEPH_MSGR_TAG_ACK) {
ret = read_partial_ack(con);
if (ret <= 0)
- goto done;
+ goto out;
process_ack(con);
goto more;
}
-done:
- ret = 0;
out:
- dout("try_read done on %p\n", con);
+ dout("try_read done on %p ret %d\n", con, ret);
return ret;
bad_tag: