On Wednesday 02 February 2011 3:24:16 pm Stefan Hajnoczi wrote:
On Tue, Feb 1, 2011 at 5:26 AM, M. Mohan Kumar mo...@in.ibm.com wrote:
+/* Receive file descriptor and error status from chroot process */
+static int v9fs_receivefd(int sockfd, int *error)
The return value and int *error overlap in functionality. Would it be
possible to have only one mechanism for returning errors?
v9fs_receivefd function returns 'fd' on success and returns EIO (and error as
EIO) if there was a socket error and -1 on other errors.
We need to return -EIO and error as EIO to differentiate between generic EIO
error and socket failure.
*error = 0 is never done so a caller that passes an uninitialized
local variable gets back junk when the function succeeds. It would be
safer to clear it at the start of this function.
I will update the patch.
Inconsistent use of errno constants and -1:
return -EIO;
return -1; /* == -EPERM, probably not what you wanted */
-1 denotes failure
How about getting rid of int *error and returning the -errno? If
if_error is set then return -fd_info.error.
Do you mean return fd on success and -errno on failure? In this case how to
differentiate between actual EIO and EIO because of socket read/write failure?
+/*
+ * V9fsFileObjectRequest is written into the socket by QEMU process.
+ * Then this request is read by chroot process using read_request
function + */
+static int v9fs_write_request(int sockfd, V9fsFileObjectRequest
*request) +{
+int retval, length;
+char *buff, *buffp;
+
+length = sizeof(request-data) + request-data.path_len +
+request-data.oldpath_len;
+
+buff = qemu_malloc(length);
+buffp = buff;
+memcpy(buffp, request-data, sizeof(request-data));
+buffp += sizeof(request-data);
+memcpy(buffp, request-path.path, request-data.path_len);
+buffp += request-data.path_len;
+memcpy(buffp, request-path.old_path, request-data.oldpath_len);
+
+retval = qemu_write_full(sockfd, buff, length);
qemu_free(buff);
Also, weren't you doing the malloc() + single write() to avoid
interleaved write()? Is that still necessary, I thought a mutex was
introduced? It's probably worth adding a comment to explain why
you're doing the malloc + write.
This is used to avoid multiple write system calls. Probably I can update with
comments.
M. Mohan Kumar
