Attachment 1284124 Details for Bug 1394862 – rpm lock check patch v3

[patch] rpm lock check patch v3

db-5.3.28-rpm-lock-check.patch (text/plain), 2.28 KB, created by Petr Kubat on 2017-06-01 10:55:52 UTC

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Creator: Petr Kubat

Created: 2017-06-01 10:55:52 UTC

Size: 2.28 KB

patch

obsolete

>diff -up db-5.3.28/src/env/env_region.c.rpmchk db-5.3.28/src/env/env_region.c
>--- db-5.3.28/src/env/env_region.c.rpmchk	2017-06-01 12:09:49.191891965 +0200
>+++ db-5.3.28/src/env/env_region.c	2017-06-01 12:09:49.193891929 +0200
>@@ -289,7 +289,8 @@ user_map_functions:
> 
> 	if (create_ok &&
> 	    __env_check_recreate(env, renv, signature) == DB_OLD_VERSION &&
>-	    (ret = ENV_PRIMARY_LOCK(env, DB_LOCK_WRITE, 1)) == 0) {
>+	    (ret = ENV_PRIMARY_LOCK(env, DB_LOCK_WRITE, 1)) == 0 &&
>+        (ret = __rpm_lock_check(env)) == 0 ) {
> 		if (FLD_ISSET(dbenv->verbose, DB_VERB_RECOVERY))
> 			__db_msg(env, "Recreating idle environment");
> 		F_SET(infop, REGION_CREATE_OK);
>diff -up db-5.3.28/src/os/os_flock.c.rpmchk db-5.3.28/src/os/os_flock.c
>--- db-5.3.28/src/os/os_flock.c.rpmchk	2017-06-01 12:09:49.191891965 +0200
>+++ db-5.3.28/src/os/os_flock.c	2017-06-01 12:16:28.309175645 +0200
>@@ -15,6 +15,53 @@ static int __os_filelocking_notsup __P((
> #endif
> 
> /*
>+ * __rpm_lock_check --
>+ *	Try to acquire and release a lock used by rpm to see
>+ *	if libdb is being updated and it is safe to access
>+ *	its environment files.
>+ *
>+ *	FIXME: This function leaks the file descriptor on purpose
>+ *	so that rpm's transaction lock is not dropped due to
>+ *	how fcntl locks interact with close(2).
>+ */
>+
>+#define RPM_PATH SHAREDSTATEDIR "/rpm"
>+#define RPMLOCK_PATH RPM_PATH "/.rpm.lock"
>+
>+int __rpm_lock_check(env)
>+    ENV *env;
>+{
>+#ifdef HAVE_FCNTL
>+    struct flock info;
>+    int fd;
>+    int ret;
>+
>+    if (strstr(env->db_home, RPM_PATH) == NULL)
>+        /* No need to check the transaction lock if not in rpm */
>+        return 0;
>+
>+    fd = open(RPMLOCK_PATH, O_RDWR);
>+    if (fd == -1)
>+        return 1;
>+    /* Try to get an exclusive lock on rpm's lock file */
>+    info.l_type = F_WRLCK;
>+    info.l_whence = SEEK_SET;
>+    info.l_start = 0;
>+    info.l_len = 0;
>+    info.l_pid = 0;
>+    /* We do not want to hold so just check if we can get it */
>+    if ((ret = fcntl(fd, F_GETLK, &info)) != -1 && info.l_type == F_UNLCK)
>+        /* Lock is not taken, the environment can be rebuilt */
>+        return 0;
>+    else
>+        return 1;
>+#else
>+    /* fcntl not supported, fail with error message */
>+    return __os_filelocking_notsup(env);
>+#endif
>+}
>+
>+/*
>  * __os_fdlock --
>  *	Acquire/release a lock on a byte in a file.
>  *

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Attachments on bug 1394862: 1279226 | 1283384 | 1284053 | 1284124 | 1287101 | 1289098 | 1289099