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author | Joe Hershberger <joe.hershberger@ni.com> | 2012-10-03 09:38:49 (GMT) |
---|---|---|
committer | Tom Rini <trini@ti.com> | 2012-10-15 18:54:05 (GMT) |
commit | e4a223f04de2e271682f26d7b981c0012f6a459f (patch) | |
tree | 61f1e3cdd6a2e1f92180c3708fc832bf10472610 | |
parent | d9acae1a880a52b3a6ad24af8c7f8312e59ea9b1 (diff) | |
download | u-boot-e4a223f04de2e271682f26d7b981c0012f6a459f.tar.xz |
tools/env: Serialize calls to fw_*env
Use a lock file at /var/lock/fw_printenv.lock.
Avoids seriously confusing the MTD driver.
Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
-rw-r--r-- | tools/env/fw_env_main.c | 59 |
1 files 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" #define CMD_PRINTENV "fw_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; } |