X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=udev%2Fudev-node.c;h=a70c147d3edb5a4d52db7d9a8504172a1fa739bc;hb=7b4038a96f6f581aea43ac97f47defdedc524e8b;hp=3685485eb1066a113226733e366aa5eeb0160f3c;hpb=676d294c23cf999ac7d192b058476f91242550c0;p=elogind.git

diff --git a/udev/udev-node.c b/udev/udev-node.c
index 3685485eb..a70c147d3 100644
--- a/udev/udev-node.c
+++ b/udev/udev-node.c
@@ -25,6 +25,7 @@
 #include <errno.h>
 #include <grp.h>
 #include <dirent.h>
+#include <sys/time.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 
@@ -55,6 +56,8 @@ int udev_node_mknod(struct udev_device *dev, const char *file, dev_t devnum, mod
 			info(udev, "preserve file '%s', because it has correct dev_t\n", file);
 			preserve = 1;
 			udev_selinux_lsetfilecon(udev, file, mode);
+			/* update time stamp when we re-use the node, like on media change events */
+			utimes(file, NULL);
 		} else {
 			char file_tmp[UTIL_PATH_SIZE + sizeof(TMP_FILE_EXT)];
 
@@ -77,10 +80,16 @@ int udev_node_mknod(struct udev_device *dev, const char *file, dev_t devnum, mod
 		}
 	} else {
 		info(udev, "mknod(%s, %#o, (%u,%u))\n", file, mode, major(devnum), minor(devnum));
-		util_create_path(udev, file);
-		udev_selinux_setfscreatecon(udev, file, mode);
-		err = mknod(file, mode, devnum);
-		udev_selinux_resetfscreatecon(udev);
+		do {
+			err = util_create_path(udev, file);
+			if (err != 0 && err != -ENOENT)
+				break;
+			udev_selinux_setfscreatecon(udev, file, mode);
+			err = mknod(file, mode, devnum);
+			if (err != 0)
+				err = -errno;
+			udev_selinux_resetfscreatecon(udev);
+		} while (err == -ENOENT);
 		if (err != 0) {
 			err(udev, "mknod(%s, %#o, (%u,%u) failed: %m\n", file, mode, major(devnum), minor(devnum));
 			goto exit;
@@ -169,16 +178,23 @@ static int node_symlink(struct udev *udev, const char *node, const char *slink)
 					info(udev, "preserve already existing symlink '%s' to '%s'\n",
 					     slink, target);
 					udev_selinux_lsetfilecon(udev, slink, S_IFLNK);
+					lutimes(slink, NULL);
 					goto exit;
 				}
 			}
 		}
 	} else {
 		info(udev, "creating symlink '%s' to '%s'\n", slink, target);
-		util_create_path(udev, slink);
-		udev_selinux_setfscreatecon(udev, slink, S_IFLNK);
-		err = symlink(target, slink);
-		udev_selinux_resetfscreatecon(udev);
+		do {
+			err = util_create_path(udev, slink);
+			if (err != 0 && err != -ENOENT)
+				break;
+			udev_selinux_setfscreatecon(udev, slink, S_IFLNK);
+			err = symlink(target, slink);
+			if (err != 0)
+				err = -errno;
+			udev_selinux_resetfscreatecon(udev);
+		} while (err == -ENOENT);
 		if (err == 0)
 			goto exit;
 	}
@@ -186,10 +202,16 @@ static int node_symlink(struct udev *udev, const char *node, const char *slink)
 	info(udev, "atomically replace '%s'\n", slink);
 	util_strscpyl(slink_tmp, sizeof(slink_tmp), slink, TMP_FILE_EXT, NULL);
 	unlink(slink_tmp);
-	util_create_path(udev, slink);
-	udev_selinux_setfscreatecon(udev, slink, S_IFLNK);
-	err = symlink(target, slink_tmp);
-	udev_selinux_resetfscreatecon(udev);
+	do {
+		err = util_create_path(udev, slink_tmp);
+		if (err != 0 && err != -ENOENT)
+			break;
+		udev_selinux_setfscreatecon(udev, slink_tmp, S_IFLNK);
+		err = symlink(target, slink_tmp);
+		if (err != 0)
+			err = -errno;
+		udev_selinux_resetfscreatecon(udev);
+	} while (err == -ENOENT);
 	if (err != 0) {
 		err(udev, "symlink(%s, %s) failed: %m\n", target, slink_tmp);
 		goto exit;
@@ -263,6 +285,7 @@ static const char *link_find_prioritized(struct udev_device *dev, bool add, cons
 			udev_device_unref(dev_db);
 		}
 	}
+	closedir(dir);
 	return target;
 }
 
@@ -301,9 +324,17 @@ static void link_update(struct udev_device *dev, const char *slink, bool add)
 	}
 
 	if (add) {
+		int err;
+
 		dbg(udev, "creating index: '%s'\n", filename);
-		util_create_path(udev, filename);
-		symlink(udev_device_get_devpath(dev), filename);
+		do {
+			err = util_create_path(udev, filename);
+			if (err != 0 && err != -ENOENT)
+				break;
+			err = symlink(udev_device_get_devpath(dev), filename);
+			if (err != 0)
+				err = -errno;
+		} while (err == -ENOENT);
 	}
 }
 
@@ -391,10 +422,11 @@ int udev_node_remove(struct udev_device *dev)
 	const char *devnode;
 	char partitionname[UTIL_PATH_SIZE];
 	struct stat stats;
+	struct udev_device *dev_check;
 	int err = 0;
 	int num;
 
-	/* remove,update symlinks, remove symlinks from name index */
+	/* remove/update symlinks, remove symlinks from name index */
 	udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev))
 		link_update(dev, udev_list_entry_get_name(list_entry), 0);
 
@@ -410,10 +442,15 @@ int udev_node_remove(struct udev_device *dev)
 		return -1;
 	}
 
-	info(udev, "removing device node '%s'\n", devnode);
-	err = util_unlink_secure(udev, devnode);
-	if (err)
-		return err;
+	dev_check = udev_device_new_from_syspath(udev, udev_device_get_syspath(dev));
+	if (dev_check != NULL && stats.st_rdev == udev_device_get_devnum(dev_check)) {
+		/* do not remove device node if the same sys-device is re-created in the meantime */
+		info(udev, "keeping device node of existing device'%s'\n", devnode);
+	} else {
+		info(udev, "removing device node '%s'\n", devnode);
+		err = util_unlink_secure(udev, devnode);
+	}
+	udev_device_unref(dev_check);
 
 	num = udev_device_get_num_fake_partitions(dev);
 	if (num > 0) {