From 610c25e8b123430377a9dd55c33ee09018135ea2 Mon Sep 17 00:00:00 2001
From: Alasdair Kergon <agk@redhat.com>
Date: Wed, 23 Jan 2002 18:55:01 +0000
Subject: [PATCH] o Remove redundant symlink-handling code. o When opening
 device, return error if its cached name is incorrect (eg if   it's changed
 since the cache was generated).  This prevents use until   the cache is
 rebuilt (eg with vgscan).  Doesn't catch every case.

---
 lib/device/dev-cache.c | 39 ---------------------------------------
 lib/device/dev-io.c    | 13 ++++++++++++-
 2 files changed, 12 insertions(+), 40 deletions(-)

diff --git a/lib/device/dev-cache.c b/lib/device/dev-cache.c
index a87042738..5a5daf112 100644
--- a/lib/device/dev-cache.c
+++ b/lib/device/dev-cache.c
@@ -120,28 +120,6 @@ static int _insert_dev(const char *path, dev_t d)
 	return 1;
 }
 
-/*
- * return a new path for the destination of the link.
- */
-static char *_follow_link(const char *path, struct stat *info)
-{
-	char buffer[PATH_MAX + 1];
-	int n;
-	n = readlink(path, buffer, sizeof(buffer) - 1);
-
-	if (n <= 0)
-		return NULL;
-
-	buffer[n] = '\0';
-
-	if (stat(buffer, info) < 0) {
-		log_sys_very_verbose("stat", buffer);
-		return NULL;
-	}
-
-	return pool_strdup(_cache.mem, buffer);
-}
-
 static char *_join(const char *dir, const char *name)
 {
 	int len = strlen(dir) + strlen(name) + 2;
@@ -208,7 +186,6 @@ static int _insert_dir(const char *dir)
 static int _insert(const char *path, int rec)
 {
 	struct stat info;
-	char *actual_path;
 	int r = 0;
 
 	if (stat(path, &info) < 0) {
@@ -216,22 +193,6 @@ static int _insert(const char *path, int rec)
 		return 0;
 	}
 
-	/* follow symlinks if neccessary. */
-	if (S_ISLNK(info.st_mode)) {
-		log_debug("%s: Following symbolic link", path);
-		if (!(actual_path = _follow_link(path, &info))) {
-			stack;
-			return 0;
-		}
-
-		if (stat(actual_path, &info) < 0) {
-			log_sys_very_verbose("stat", actual_path);
-			return 0;
-		}
-
-		dbg_free(actual_path);
-	}
-
 	if (S_ISDIR(info.st_mode)) { /* add a directory */
 		if (rec)
 			r = _insert_dir(path);
diff --git a/lib/device/dev-io.c b/lib/device/dev-io.c
index 5fac6d5ea..dece35c67 100644
--- a/lib/device/dev-io.c
+++ b/lib/device/dev-io.c
@@ -64,19 +64,30 @@ int dev_get_sectsize(struct device *dev, uint32_t *size)
 
 int dev_open(struct device *dev, int flags)
 {
+	struct stat buf;
 	const char *name = dev_name(dev);
 
-	/* FIXME Check flags (eg is write now reqd?) */
 	if (dev->fd >= 0) {
 		log_error("Device '%s' has already been opened", name);
 		return 0;
 	}
 
+	if ((stat(name, &buf) < 0) || (buf.st_rdev != dev->dev)) {
+		log_error("%s: stat failed: Has device name changed?", name);
+		return 0;
+	}
+
 	if ((dev->fd = open(name, flags)) < 0) {
 		log_sys_error("open", name);
 		return 0;
 	}
 
+	if ((fstat(dev->fd, &buf) < 0) || (buf.st_rdev != dev->dev)) {
+		log_error("%s: fstat failed: Has device name changed?", name);
+		dev_close(dev->fd);
+		return 0;
+	}
+
 	return 1;
 }
 
-- 
2.43.5