Detect partition table signature.

WHATS_NEW

@@ -1,5 +1,6 @@
 Version 2.00.26 - 
 =====================================
+  Detect partition table signature.
   pvcreate wipes md superblocks. (With --uuid or --restorefile it prompts.)
   Separate out md superblock detection code.
   Prevent snapshot origin resizing.

lib/device/device.c

@@ -13,6 +13,54 @@
  * Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
+#include "lib.h"
+#include "lvm-types.h"
+#include "device.h"
+#include "metadata.h"
+#include "filter.h"
+
+#define PART_MAGIC 0xAA55
+
+static int _is_whole_disk(struct device *dev)
+{
+	int parts = max_partitions(MINOR(dev->dev));
+
+	if (!parts || !(MINOR(dev->dev) % parts))
+		return 1;
+
+	return 0;
+}
+
+static int _has_partition_table(struct device *dev)
+{
+	int ret = 0;
+	uint32_t part_magic;
+	uint64_t part_offset;
+
+	if (!dev_open(dev)) {
+		stack;
+		return -1;
+	}
+
+	part_offset = sizeof(unsigned short) * 255;
+	if (dev_read(dev, part_offset, sizeof(part_magic), &part_magic) &&
+	    (part_magic == PART_MAGIC))
+		ret = 1;
+
+	if (!dev_close(dev))
+		stack;
+
+	return ret;
+}
+
+int is_partitioned_dev(struct device *dev)
+{
+	if (_is_whole_disk(dev))
+		return 0;
+
+	return _has_partition_table(dev);
+}
+
 #if 0
 #include <sys/stat.h>
 #include <sys/mman.h>
@@ -27,24 +75,13 @@
 #include <linux/major.h>
 #include <linux/genhd.h>
 
-#include "dbg_malloc.h"
-#include "log.h"
-#include "dev-cache.h"
-#include "metadata.h"
-#include "device.h"
-
 int _get_partition_type(struct dev_filter *filter, struct device *d);
 
-#define MINOR_PART(dm, d) (MINOR((d)->dev) % dev_max_partitions(dm, (d)->dev))
+#define MINOR_PART(dev) (MINOR((dev)->dev) % max_partitions(MINOR((dev)->dev)))
 
-int is_whole_disk(struct dev_filter *filter, struct device *d)
+int is_extended_partition(struct device *d)
 {
-	return (MINOR_PART(dm, d)) ? 0 : 1;
-}
-
-int is_extended_partition(struct dev_mgr *dm, struct device *d)
-{
-	return (MINOR_PART(dm, d) > 4) ? 1 : 0;
+	return (MINOR_PART(d) > 4) ? 1 : 0;
 }
 
 struct device *dev_primary(struct dev_mgr *dm, struct device *d)

lib/device/device.h

@@ -95,12 +95,8 @@ int dev_is_md(struct device *dev, uint64_t *sb);
 /* FIXME Check partition type if appropriate */
 
 #define is_lvm_partition(a) 1
+/* int is_lvm_partition(const char *name); */
 
-/*
-static inline int is_lvm_partition(const char *name)
-{
-	return 1;
-}
-*/
+int is_partitioned_dev(struct device *dev);
 
 #endif

lib/filters/filter.c

@@ -27,6 +27,9 @@
 
 #define NUMBER_OF_MAJORS 4096
 
+/* FIXME Make this sparse */
+static int _max_partitions_by_major[NUMBER_OF_MAJORS];
+
 typedef struct {
 	const char *name;
 	const int max_partitions;
@@ -62,29 +65,34 @@ static const device_info_t device_info[] = {
 static int _passes_lvm_type_device_filter(struct dev_filter *f,
 					  struct device *dev)
 {
-	int fd;
 	const char *name = dev_name(dev);
+	int ret = 1;
 
 	/* Is this a recognised device type? */
-	if (!(((int *) f->private)[MAJOR(dev->dev)])) {
+	if (!_max_partitions_by_major[MAJOR(dev->dev)]) {
 		log_debug("%s: Skipping: Unrecognised LVM device type %"
 			  PRIu64, name, (uint64_t) MAJOR(dev->dev));
 		return 0;
 	}
 
 	/* Check it's accessible */
-	if ((fd = open(name, O_RDONLY)) < 0) {
-		log_debug("%s: Skipping: open failed: %s", name,
-			  strerror(errno));
+	if (!dev_open_flags(dev, O_RDONLY, 0, 0)) {
+		log_debug("%s: Skipping: open failed", name);
 		return 0;
 	}
+	
+	if (is_partitioned_dev(dev)) {
+		log_debug("%s: Skipping: partition table signature found",
+			  name);
+		ret = 0;
+	}
 
-	close(fd);
+	dev_close(dev);
 
-	return 1;
+	return ret;
 }
 
-static int *_scan_proc_dev(const char *proc, const struct config_node *cn)
+static int _scan_proc_dev(const char *proc, const struct config_node *cn)
 {
 	char line[80];
 	char proc_devices[PATH_MAX];
@@ -94,36 +102,29 @@ static int *_scan_proc_dev(const char *proc, const struct config_node *cn)
 	int blocksection = 0;
 	size_t dev_len = 0;
 	struct config_value *cv;
-	int *max_partitions_by_major;
 	char *name;
 
-	/* FIXME Make this sparse */
-	if (!(max_partitions_by_major =
-	      dbg_malloc(sizeof(int) * NUMBER_OF_MAJORS))) {
-		log_error("Filter failed to allocate max_partitions_by_major");
-		return NULL;
-	}
-
 	if (!*proc) {
 		log_verbose("No proc filesystem found: using all block device "
 			    "types");
 		for (i = 0; i < NUMBER_OF_MAJORS; i++)
-			max_partitions_by_major[i] = 1;
-		return max_partitions_by_major;
+			_max_partitions_by_major[i] = 1;
+		return 1;
 	}
 
+	memset(_max_partitions_by_major, 0, sizeof(int) * NUMBER_OF_MAJORS);
+
 	if (lvm_snprintf(proc_devices, sizeof(proc_devices),
 			 "%s/devices", proc) < 0) {
 		log_error("Failed to create /proc/devices string");
-		return NULL;
+		return 0;
 	}
 
 	if (!(pd = fopen(proc_devices, "r"))) {
 		log_sys_error("fopen", proc_devices);
-		return NULL;
+		return 0;
 	}
 
-	memset(max_partitions_by_major, 0, sizeof(int) * NUMBER_OF_MAJORS);
 	while (fgets(line, 80, pd) != NULL) {
 		i = 0;
 		while (line[i] == ' ' && line[i] != '\0')
@@ -158,13 +159,13 @@ static int *_scan_proc_dev(const char *proc, const struct config_node *cn)
 			if (dev_len <= strlen(line + i) &&
 			    !strncmp(device_info[j].name, line + i, dev_len) &&
 			    (line_maj < NUMBER_OF_MAJORS)) {
-				max_partitions_by_major[line_maj] =
+				_max_partitions_by_major[line_maj] =
 				    device_info[j].max_partitions;
 				break;
 			}
 		}
 
-		if (max_partitions_by_major[line_maj] || !cn)
+		if (_max_partitions_by_major[line_maj] || !cn)
 			continue;
 
 		/* Check devices/types for local variations */
@@ -172,7 +173,7 @@ static int *_scan_proc_dev(const char *proc, const struct config_node *cn)
 			if (cv->type != CFG_STRING) {
 				log_error("Expecting string in devices/types "
 					  "in config file");
-				return NULL;
+				return 0;
 			}
 			dev_len = strlen(cv->v.str);
 			name = cv->v.str;
@@ -181,24 +182,29 @@ static int *_scan_proc_dev(const char *proc, const struct config_node *cn)
 				log_error("Max partition count missing for %s "
 					  "in devices/types in config file",
 					  name);
-				return NULL;
+				return 0;
 			}
 			if (!cv->v.i) {
 				log_error("Zero partition count invalid for "
 					  "%s in devices/types in config file",
 					  name);
-				return NULL;
+				return 0;
 			}
 			if (dev_len <= strlen(line + i) &&
 			    !strncmp(name, line + i, dev_len) &&
 			    (line_maj < NUMBER_OF_MAJORS)) {
-				max_partitions_by_major[line_maj] = cv->v.i;
+				_max_partitions_by_major[line_maj] = cv->v.i;
 				break;
 			}
 		}
 	}
 	fclose(pd);
-	return max_partitions_by_major;
+	return 1;
+}
+
+int max_partitions(int major)
+{
+	return _max_partitions_by_major[major];
 }
 
 struct dev_filter *lvm_type_filter_create(const char *proc,
@@ -213,8 +219,9 @@ struct dev_filter *lvm_type_filter_create(const char *proc,
 
 	f->passes_filter = _passes_lvm_type_device_filter;
 	f->destroy = lvm_type_filter_destroy;
+	f->private = NULL;
 
-	if (!(f->private = _scan_proc_dev(proc, cn))) {
+	if (!_scan_proc_dev(proc, cn)) {
 		stack;
 		return NULL;
 	}
@@ -224,7 +231,6 @@ struct dev_filter *lvm_type_filter_create(const char *proc,
 
 void lvm_type_filter_destroy(struct dev_filter *f)
 {
-	dbg_free(f->private);
 	dbg_free(f);
 	return;
 }

lib/filters/filter.h

@@ -37,4 +37,6 @@ void lvm_type_filter_destroy(struct dev_filter *f);
 
 int md_major(void);
 
+int max_partitions(int major);
+
 #endif