Package: devmapper Version: 2:1.02.20-2 Severity: wishlist Tags: patch Please apply our patch (also submitted upstream) to make the device node creation more atomic, and avoid races with udev which also attempts to create these devices.
-- System Information: Debian Release: lenny/sid APT prefers gutsy-updates APT policy: (500, 'gutsy-updates'), (500, 'gutsy-security'), (500, 'gutsy') Architecture: amd64 (x86_64) Kernel: Linux 2.6.22-14-generic (SMP w/2 CPU cores) Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8) Shell: /bin/sh linked to /bin/dash
--- devmapper-1.02.20.orig/lib/libdm-common.c
+++ devmapper-1.02.20/lib/libdm-common.c
@@ -252,12 +252,11 @@
static int _add_dev_node(const char *dev_name, uint32_t major, uint32_t minor,
uid_t uid, gid_t gid, mode_t mode)
{
- char path[PATH_MAX];
+ char path[PATH_MAX], tmppath[PATH_MAX + 7];
struct stat info;
dev_t dev = MKDEV(major, minor);
mode_t old_mask;
-
- _build_dev_path(path, sizeof(path), dev_name);
+ int retval;
if (stat(path, &info) >= 0) {
if (!S_ISBLK(info.st_mode)) {
@@ -269,31 +268,39 @@
/* If right inode already exists we don't touch uid etc. */
if (info.st_rdev == dev)
return 1;
-
- if (unlink(path) < 0) {
- log_error("Unable to unlink device node for '%s'",
- dev_name);
- return 0;
- }
}
+ _build_dev_path(path, sizeof(path), dev_name);
+ strcpy (tmppath, path);
+ strcat (tmppath, ".dm-tmp");
+
old_mask = umask(0);
- if (mknod(path, S_IFBLK | mode, dev) < 0) {
- log_error("Unable to make device node for '%s'", dev_name);
+ retval = mknod(tmppath, S_IFBLK | mode, dev);
+ umask(old_mask);
+ if (retval < 0) {
+ log_error("Unable to make temporary device node for '%s'", dev_name);
return 0;
}
- umask(old_mask);
- if (chown(path, uid, gid) < 0) {
+ if (chown(tmppath, uid, gid) < 0) {
log_error("%s: chown failed: %s", path, strerror(errno));
+ unlink(tmppath);
return 0;
}
#ifdef HAVE_SELINUX
- if (!dm_set_selinux_context(path, S_IFBLK))
+ if (!dm_set_selinux_context(tmppath, S_IFBLK)) {
+ unlink(tmppath);
return 0;
+ }
#endif
+ if (rename(tmppath, path) < 0) {
+ log_error("Unable to replace device node for '%s'", dev_name);
+ unlink(tmppath);
+ return 0;
+ }
+
return 1;
}
signature.asc
Description: This is a digitally signed message part
