Refuse to run pvcreate/pvremove on devices we can't open exclusively.

WHATS_NEW

@@ -1,5 +1,6 @@
 Version 2.01.15 - 
 =================================
+  Refuse to run pvcreate/pvremove on devices we can't open exclusively.
   Use ORPHAN lock definition throughout.
   Validate chunksize in lvcreate.
   Reduce chunksize limit to 512k.

lib/device/dev-io.c

@@ -320,15 +320,22 @@ int dev_open_flags(struct device *dev, int flags, int direct, int quiet)
 {
 	struct stat buf;
 	const char *name;
+	int need_excl = 0, need_rw = 0;
+
+	if ((flags & O_ACCMODE) == O_RDWR)
+		need_rw = 1;
+
+	if ((flags & O_EXCL))
+		need_excl = 1;
 
 	if (dev->fd >= 0) {
-		if ((dev->flags & DEV_OPENED_RW) ||
+		if (((dev->flags & DEV_OPENED_RW) || !need_rw) &&
-		    ((flags & O_ACCMODE) != O_RDWR)) {
+		    ((dev->flags & DEV_OPENED_EXCL) || !need_excl)) {
 			dev->open_count++;
 			return 1;
 		}
 
-		if (dev->open_count) {
+		if (dev->open_count && !need_excl) {
 			/* FIXME Ensure we never get here */
 			log_debug("WARNING: %s already opened read-only", 
 				  dev_name(dev));
@@ -397,11 +404,16 @@ int dev_open_flags(struct device *dev, int flags, int direct, int quiet)
 	dev->open_count++;
 	dev->flags &= ~DEV_ACCESSED_W;
 
-	if ((flags & O_ACCMODE) == O_RDWR)
+	if (need_rw)
 		dev->flags |= DEV_OPENED_RW;
 	else
 		dev->flags &= ~DEV_OPENED_RW;
 
+	if (need_excl)
+		dev->flags |= DEV_OPENED_EXCL;
+	else
+		dev->flags &= ~DEV_OPENED_EXCL;
+
 	if (!(dev->flags & DEV_REGULAR) &&
 	    ((fstat(dev->fd, &buf) < 0) || (buf.st_rdev != dev->dev))) {
 		log_error("%s: fstat failed: Has device name changed?", name);
@@ -420,8 +432,9 @@ int dev_open_flags(struct device *dev, int flags, int direct, int quiet)
 
 	list_add(&_open_devices, &dev->open_list);
 
-	log_debug("Opened %s %s%s", dev_name(dev),
+	log_debug("Opened %s %s%s%s", dev_name(dev),
 		  dev->flags & DEV_OPENED_RW ? "RW" : "RO",
+		  dev->flags & DEV_OPENED_EXCL ? " O_EXCL" : "",
 		  dev->flags & DEV_O_DIRECT ? " O_DIRECT" : "");
 
 	return 1;
@@ -445,6 +458,21 @@ int dev_open(struct device *dev)
 	return dev_open_flags(dev, flags, 1, 0);
 }
 
+int dev_test_excl(struct device *dev)
+{
+	int flags;
+	int r;
+
+	flags = vg_write_lock_held() ? O_RDWR : O_RDONLY;
+	flags |= O_EXCL;
+
+	r = dev_open_flags(dev, flags, 1, 1);
+	if (r)
+		dev_close_immediate(dev);
+
+	return r;
+}
+
 static void _close(struct device *dev)
 {
 	if (close(dev->fd))
@@ -479,6 +507,11 @@ static int _dev_close(struct device *dev, int immediate)
 	if (dev->open_count > 0)
 		dev->open_count--;
 
+	if (immediate && dev->open_count) {
+		log_debug("%s: Immediate close attempt while still referenced");
+		dev->open_count = 0;
+	}
+
 	/* FIXME lookup device in cache to get vgname and see if it's locked? */
 	if (immediate || (dev->open_count < 1 && !vgs_locked()))
 		_close(dev);

lib/device/device.h

@@ -23,8 +23,9 @@
 #define DEV_REGULAR		0x00000002	/* Regular file? */
 #define DEV_ALLOCED		0x00000004	/* dbg_malloc used */
 #define DEV_OPENED_RW		0x00000008	/* Opened RW */
-#define DEV_O_DIRECT		0x00000010	/* Use O_DIRECT */
+#define DEV_OPENED_EXCL		0x00000010	/* Opened EXCL */
-#define DEV_O_DIRECT_TESTED	0x00000020	/* DEV_O_DIRECT is reliable */
+#define DEV_O_DIRECT		0x00000020	/* Use O_DIRECT */
+#define DEV_O_DIRECT_TESTED	0x00000040	/* DEV_O_DIRECT is reliable */
 
 /*
  * All devices in LVM will be represented by one of these.
@@ -70,6 +71,7 @@ int dev_open_flags(struct device *dev, int flags, int direct, int quiet);
 int dev_close(struct device *dev);
 int dev_close_immediate(struct device *dev);
 void dev_close_all(void);
+int dev_test_excl(struct device *dev);
 
 static inline int dev_fd(struct device *dev)
 {

tools/pvcreate.c

@@ -82,6 +82,12 @@ static int pvcreate_check(struct cmd_context *cmd, const char *name)
 		return 0;
 	}
 
+	if (!dev_test_excl(dev)) {
+		log_error("Can't open %s exclusively.  Mounted filesystem?",
+			  name);
+		return 0;
+	}
+
 	/* Wipe superblock? */
 	if (dev_is_md(dev, &md_superblock) &&
 	    ((!arg_count(cmd, uuidstr_ARG) &&
@@ -219,7 +225,11 @@ static int pvcreate_single(struct cmd_context *cmd, const char *pv_name,
 			goto error;
 		}
 
-		dev_zero(dev, UINT64_C(0), (size_t) 2048);
+		if (!dev_zero(dev, UINT64_C(0), (size_t) 2048)) {
+			log_error("%s not wiped: aborting", pv_name);
+			dev_close(dev);
+			goto error;
+		}
 		dev_close(dev);
 	}
 

tools/pvremove.c

@@ -86,6 +86,12 @@ static int pvremove_single(struct cmd_context *cmd, const char *pv_name,
 		goto error;
 	}
 
+	if (!dev_test_excl(dev)) {
+		log_error("Can't open %s exclusively.  Mounted filesystem?",
+			  dev_name(dev));
+		return 0;
+	}
+
 	/* Wipe existing label(s) */
 	if (!label_remove(dev)) {
 		log_error("Failed to wipe existing label(s) on %s", pv_name);