[U-Boot] [PATCH v2 4/5] tools/env: Serialize calls to fw_*env

2012-10-03 Thread Joe Hershberger
Use a lock file at /var/lock/fw_printenv.lock.
Avoids seriously confusing the MTD driver.

Signed-off-by: Joe Hershberger joe.hershber...@ni.com
---

 tools/env/fw_env_main.c | 59 +++--
 1 file changed, 37 insertions(+), 22 deletions(-)

diff --git a/tools/env/fw_env_main.c b/tools/env/fw_env_main.c
index c654057..c855f4c 100644
--- a/tools/env/fw_env_main.c
+++ b/tools/env/fw_env_main.c
@@ -39,10 +39,13 @@
  *   variable name
  */
 
+#include fcntl.h
+#include getopt.h
 #include stdio.h
 #include string.h
 #include stdlib.h
-#include getopt.h
+#include sys/file.h
+#include unistd.h
 #include fw_env.h
 
 #defineCMD_PRINTENVfw_printenv
@@ -81,13 +84,27 @@ void usage(void)
);
 }
 
-int
-main(int argc, char *argv[])
+int main(int argc, char *argv[])
 {
char *p;
char *cmdname = *argv;
char *script_file = NULL;
int c;
+   const char *lockname = /var/lock/ CMD_PRINTENV .lock;
+   int lockfd = -1;
+   int retval = EXIT_SUCCESS;
+
+   lockfd = open(lockname, O_WRONLY | O_CREAT | O_TRUNC);
+   if (-1 == lockfd) {
+   fprintf(stderr, Error opening lock file %s\n, lockname);
+   return EXIT_FAILURE;
+   }
+
+   if (-1 == flock(lockfd, LOCK_EX)) {
+   fprintf(stderr, Error locking file %s\n, lockname);
+   close(lockfd);
+   return EXIT_FAILURE;
+   }
 
if ((p = strrchr (cmdname, '/')) != NULL) {
cmdname = p + 1;
@@ -104,38 +121,36 @@ main(int argc, char *argv[])
break;
case 'h':
usage();
-   return EXIT_SUCCESS;
+   goto exit;
default: /* '?' */
fprintf(stderr, Try `%s --help' for more information.
\n, cmdname);
-   return EXIT_FAILURE;
+   retval = EXIT_FAILURE;
+   goto exit;
}
}
 
-
if (strcmp(cmdname, CMD_PRINTENV) == 0) {
-
-   if (fw_printenv (argc, argv) != 0)
-   return EXIT_FAILURE;
-
-   return EXIT_SUCCESS;
-
+   if (fw_printenv(argc, argv) != 0)
+   retval = EXIT_FAILURE;
} else if (strcmp(cmdname, CMD_SETENV) == 0) {
if (!script_file) {
if (fw_setenv(argc, argv) != 0)
-   return EXIT_FAILURE;
+   retval = EXIT_FAILURE;
} else {
if (fw_parse_script(script_file) != 0)
-   return EXIT_FAILURE;
+   retval = EXIT_FAILURE;
}
-
-   return EXIT_SUCCESS;
-
+   } else {
+   fprintf(stderr,
+   Identity crisis - may be called as ` CMD_PRINTENV
+   ' or as ` CMD_SETENV ' but not as `%s'\n,
+   cmdname);
+   retval = EXIT_FAILURE;
}
 
-   fprintf (stderr,
-   Identity crisis - may be called as ` CMD_PRINTENV
-   ' or as ` CMD_SETENV ' but not as `%s'\n,
-   cmdname);
-   return EXIT_FAILURE;
+exit:
+   flock(lockfd, LOCK_UN);
+   close(lockfd);
+   return retval;
 }
-- 
1.7.11.5

___
U-Boot mailing list
U-Boot@lists.denx.de
http://lists.denx.de/mailman/listinfo/u-boot


Re: [U-Boot] [PATCH v2 4/5] tools/env: Serialize calls to fw_*env

2012-10-03 Thread uboot
On Wed, Oct 03, 2012 at 02:38:49PM -0500, Joe Hershberger wrote:
 Use a lock file at /var/lock/fw_printenv.lock.
 Avoids seriously confusing the MTD driver.
 
 Signed-off-by: Joe Hershberger joe.hershber...@ni.com
 ---
 
  tools/env/fw_env_main.c | 59 
 +++--
  1 file changed, 37 insertions(+), 22 deletions(-)

I thing we should document usage and location of lock file in tools/env/README. 

Luka
___
U-Boot mailing list
U-Boot@lists.denx.de
http://lists.denx.de/mailman/listinfo/u-boot