Re: [PATCH V2 1/1] Drivers: hv: Implement the file copy service

From: Olaf Hering
Date: Thu Jan 16 2014 - 05:48:49 EST


On Tue, Jan 14, K. Y. Srinivasan wrote:

> Implement the file copy service for Linux guests on Hyper-V. This permits the
> host to copy a file (over VMBUS) into the guest. This facility is part of
> "guest integration services" supported on the Windows platform.
> Here is a link that provides additional details on this functionality:

The change below fixes some warnings in the daemon code.
Compile tested only.
I also think the newlines in some of the syslog calls should be removed.

Olaf


hv_fcopy_daemon.c: In function 'hv_start_fcopy':
hv_fcopy_daemon.c:44:3: warning: format '%s' expects argument of type 'char *', but argument 3 has type '__u16 *' [-Wformat=]
smsg->file_name);
^
hv_fcopy_daemon.c:44:3: warning: format '%s' expects argument of type 'char *', but argument 5 has type '__u16 *' [-Wformat=]
hv_fcopy_daemon.c:57:6: warning: format '%s' expects argument of type 'char *', but argument 3 has type '__u16 *' [-Wformat=]
errno, strerror(errno));
^
hv_fcopy_daemon.c:61:4: warning: format '%s' expects argument of type 'char *', but argument 3 has type '__u16 *' [-Wformat=]
syslog(LOG_ERR, "Invalid path: %s\n", smsg->path_name);
^
hv_fcopy_daemon.c: In function 'main':
hv_fcopy_daemon.c:117:8: warning: ignoring return value of 'daemon', declared with attribute warn_unused_result [-Wunused-result]
daemon(1, 0);
^
hv_fcopy_daemon.c:132:7: warning: ignoring return value of 'write', declared with attribute warn_unused_result [-Wunused-result]
write(fcopy_fd, &version, sizeof(int));
^
hv_fcopy_daemon.c:171:9: warning: ignoring return value of 'pwrite', declared with attribute warn_unused_result [-Wunused-result]
pwrite(fcopy_fd, &error, sizeof(int), 0);
^

Signed-off-by: Olaf Hering <olaf@xxxxxxxxx>

diff --git a/tools/hv/hv_fcopy_daemon.c b/tools/hv/hv_fcopy_daemon.c
index c0e5c90..d1fadb7 100644
--- a/tools/hv/hv_fcopy_daemon.c
+++ b/tools/hv/hv_fcopy_daemon.c
@@ -35,14 +35,14 @@
#include <dirent.h>

static int target_fd;
-char target_fname[W_MAX_PATH];
+static char target_fname[W_MAX_PATH];

static int hv_start_fcopy(struct hv_start_fcopy *smsg)
{
int error = HV_E_FAIL;

- sprintf(target_fname, "%s%s%s", smsg->path_name, "/",
- smsg->file_name);
+ snprintf(target_fname, sizeof(target_fname), "%s/%s",
+ (char *)smsg->path_name, (char*)smsg->file_name);

syslog(LOG_INFO, "Target file name: %s\n", target_fname);
/*
@@ -54,12 +54,12 @@ static int hv_start_fcopy(struct hv_start_fcopy *smsg)
if (mkdir((char *)smsg->path_name, 0755)) {
syslog(LOG_ERR,
"Failed to create '%s'; error: %d %s\n",
- smsg->path_name,
+ (char *)smsg->path_name,
errno, strerror(errno));
goto done;
}
} else {
- syslog(LOG_ERR, "Invalid path: %s\n", smsg->path_name);
+ syslog(LOG_ERR, "Invalid path: %s", (char *)smsg->path_name);
goto done;
}
}
@@ -115,7 +115,8 @@ int main(void)
char *buffer[4096 * 2];
struct hv_fcopy_hdr *in_msg;

- daemon(1, 0);
+ if (daemon(1, 0))
+ return 1;
openlog("HV_FCOPY", 0, LOG_USER);
syslog(LOG_INFO, "HV_FCOPY starting; pid is:%d", getpid());

@@ -130,7 +131,10 @@ int main(void)
/*
* Register with the kernel.
*/
- write(fcopy_fd, &version, sizeof(int));
+ if (write(fcopy_fd, &version, sizeof(int)) != sizeof(int)) {
+ syslog(LOG_ERR, "write failed: %s",strerror(errno));
+ exit(EXIT_FAILURE);
+ }

while (1) {
/*
@@ -169,6 +173,9 @@ int main(void)

}

- pwrite(fcopy_fd, &error, sizeof(int), 0);
+ if (pwrite(fcopy_fd, &error, sizeof(int), 0) != sizeof(int)) {
+ syslog(LOG_ERR, "pwrite failed: %s",strerror(errno));
+ exit(EXIT_FAILURE);
+ }
}
}
--
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