lib/filters/filter-mpath.c - manifest_repos/lvm2 - Git at Google

 /*
  * Copyright (C) 2011 Red Hat, Inc. All rights reserved.
  *
  * This file is part of LVM2.
  *
  * This copyrighted material is made available to anyone wishing to use,
  * modify, copy, or redistribute it subject to the terms and conditions
  * of the GNU Lesser General Public License v.2.1.
  *
  * You should have received a copy of the GNU Lesser General Public License
  * along with this program; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */

 #include "lib.h"
 #include "filter.h"
 #include "activate.h"
 #ifdef UDEV_SYNC_SUPPORT
 #include <libudev.h>
 #include "dev-ext-udev-constants.h"
 #endif

 #ifdef __linux__

 #include <dirent.h>

 #define MPATH_PREFIX "mpath-"

 static const char *_get_sysfs_name(struct device *dev)
 {
 	const char *name;

 	if (!(name = strrchr(dev_name(dev), '/'))) {
 		log_error("Cannot find '/' in device name.");
 		return NULL;
 	}
 	name++;

 	if (!*name) {
 		log_error("Device name is not valid.");
 		return NULL;
 	}

 	return name;
 }

 static const char *_get_sysfs_name_by_devt(const char *sysfs_dir, dev_t devno,
 					  char *buf, size_t buf_size)
 {
 	const char *name;
 	char path[PATH_MAX];
 	int size;

 	if (dm_snprintf(path, sizeof(path), "%s/dev/block/%d:%d", sysfs_dir,
 			(int) MAJOR(devno), (int) MINOR(devno)) < 0) {
 		log_error("Sysfs path string is too long.");
 		return NULL;
 	}

 	if ((size = readlink(path, buf, buf_size - 1)) < 0) {
 		log_sys_error("readlink", path);
 		return NULL;
 	}
 	buf[size] = '\0';

 	if (!(name = strrchr(buf, '/'))) {
 		log_error("Cannot find device name in sysfs path.");
 		return NULL;
 	}
 	name++;

 	return name;
 }

 static int _get_sysfs_string(const char *path, char *buffer, int max_size)
 {
 	FILE *fp;
 	int r = 0;

 	if (!(fp = fopen(path, "r"))) {
 		log_sys_error("fopen", path);
 		return 0;
 	}

 	if (!fgets(buffer, max_size, fp))
 		log_sys_error("fgets", path);
 	else
 		r = 1;

 	if (fclose(fp))
 		log_sys_error("fclose", path);

 	return r;
 }

 static int _get_sysfs_get_major_minor(const char *sysfs_dir, const char *kname, int *major, int *minor)
 {
 	char path[PATH_MAX], buffer[64];

 	if (dm_snprintf(path, sizeof(path), "%s/block/%s/dev", sysfs_dir, kname) < 0) {
 		log_error("Sysfs path string is too long.");
 		return 0;
 	}

 	if (!_get_sysfs_string(path, buffer, sizeof(buffer)))
 		return_0;

 	if (sscanf(buffer, "%d:%d", major, minor) != 2) {
 		log_error("Failed to parse major minor from %s", buffer);
 		return 0;
 	}

 	return 1;
 }

 static int _get_parent_mpath(const char *dir, char *name, int max_size)
 {
 	struct dirent *d;
 	DIR *dr;
 	int r = 0;

 	if (!(dr = opendir(dir))) {
 		log_sys_error("opendir", dir);
 		return 0;
 	}

 	*name = '\0';
 	while ((d = readdir(dr))) {
 		if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
 			continue;

 		/* There should be only one holder if it is multipath */
 		if (*name) {
 			r = 0;
 			break;
 		}

 		strncpy(name, d->d_name, max_size);
 		r = 1;
 	}

 	if (closedir(dr))
 		log_sys_error("closedir", dir);

 	return r;
 }

 #ifdef UDEV_SYNC_SUPPORT
 static int _udev_dev_is_mpath(struct device *dev)
 {
 	const char *value;
 	struct dev_ext *ext;

 	if (!(ext = dev_ext_get(dev)))
 		return_0;

 	value = udev_device_get_property_value((struct udev_device *)ext->handle, DEV_EXT_UDEV_BLKID_TYPE);
 	if (value && !strcmp(value, DEV_EXT_UDEV_BLKID_TYPE_MPATH))
 		return 1;

 	value = udev_device_get_property_value((struct udev_device *)ext->handle, DEV_EXT_UDEV_MPATH_DEVICE_PATH);
 	if (value && !strcmp(value, "1"))
 		return 1;

 	return 0;
 }
 #else
 static int _udev_dev_is_mpath(struct device *dev)
 {
 	return 0;
 }
 #endif

 static int _native_dev_is_mpath(struct dev_filter *f, struct device *dev)
 {
 	struct dev_types *dt = (struct dev_types *) f->private;
 	const char *part_name, *name;
 	struct stat info;
 	char path[PATH_MAX], parent_name[PATH_MAX];
 	const char *sysfs_dir = dm_sysfs_dir();
 	int major = MAJOR(dev->dev);
 	int minor = MINOR(dev->dev);
 	dev_t primary_dev;

 	/* Limit this filter only to SCSI devices */
 	if (!major_is_scsi_device(dt, MAJOR(dev->dev)))
 		return 0;

 	switch (dev_get_primary_dev(dt, dev, &primary_dev)) {
 	case 2: /* The dev is partition. */
 		part_name = dev_name(dev); /* name of original dev for log_debug msg */
 		if (!(name = _get_sysfs_name_by_devt(sysfs_dir, primary_dev, parent_name, sizeof(parent_name))))
 			return_0;
 		log_debug_devs("%s: Device is a partition, using primary "
 			       "device %s for mpath component detection",
 			       part_name, name);
 		break;
 	case 1: /* The dev is already a primary dev. Just continue with the dev. */
 		if (!(name = _get_sysfs_name(dev)))
 			return_0;
 		break;
 	default: /* 0, error. */
 		log_error("Failed to get primary device for %d:%d.", major, minor);
 		return 0;
 	}

 	if (dm_snprintf(path, sizeof(path), "%s/block/%s/holders", sysfs_dir, name) < 0) {
 		log_error("Sysfs path to check mpath is too long.");
 		return 0;
 	}

 	/* also will filter out partitions */
 	if (stat(path, &info))
 		return 0;

 	if (!S_ISDIR(info.st_mode)) {
 		log_error("Path %s is not a directory.", path);
 		return 0;
 	}

 	if (!_get_parent_mpath(path, parent_name, sizeof(parent_name)))
 		return 0;

 	if (!_get_sysfs_get_major_minor(sysfs_dir, parent_name, &major, &minor))
 		return_0;

 	if (major != dt->device_mapper_major)
 		return 0;

 	return lvm_dm_prefix_check(major, minor, MPATH_PREFIX);
 }

 static int _dev_is_mpath(struct dev_filter *f, struct device *dev)
 {
 	if (dev->ext.src == DEV_EXT_NONE)
 		return _native_dev_is_mpath(f, dev);

 	if (dev->ext.src == DEV_EXT_UDEV)
 		return _udev_dev_is_mpath(dev);

 	log_error(INTERNAL_ERROR "Missing hook for mpath recognition "
 		  "using external device info source %s", dev_ext_name(dev));

 	return 0;
 }

 #define MSG_SKIPPING "%s: Skipping mpath component device"

 static int _ignore_mpath(struct dev_filter *f, struct device *dev)
 {
 	if (_dev_is_mpath(f, dev) == 1) {
 		if (dev->ext.src == DEV_EXT_NONE)
 			log_debug_devs(MSG_SKIPPING, dev_name(dev));
 		else
 			log_debug_devs(MSG_SKIPPING " [%s:%p]", dev_name(dev),
 					dev_ext_name(dev), dev->ext.handle);
 		return 0;
 	}

 	return 1;
 }

 static void _destroy(struct dev_filter *f)
 {
 	if (f->use_count)
 		log_error(INTERNAL_ERROR "Destroying mpath filter while in use %u times.", f->use_count);

 	dm_free(f);
 }

 struct dev_filter *mpath_filter_create(struct dev_types *dt)
 {
 	const char *sysfs_dir = dm_sysfs_dir();
 	struct dev_filter *f;

 	if (!*sysfs_dir) {
 		log_verbose("No proc filesystem found: skipping multipath filter");
 		return NULL;
 	}

 	if (!(f = dm_zalloc(sizeof(*f)))) {
 		log_error("mpath filter allocation failed");
 		return NULL;
 	}

 	f->passes_filter = _ignore_mpath;
 	f->destroy = _destroy;
 	f->use_count = 0;
 	f->private = dt;

 	log_debug_devs("mpath filter initialised.");

 	return f;
 }

 #else

 struct dev_filter *mpath_filter_create(struct dev_types *dt)
 {
 	return NULL;
 }

 #endif
	/*
	* Copyright (C) 2011 Red Hat, Inc. All rights reserved.
	*
	* This file is part of LVM2.
	*
	* This copyrighted material is made available to anyone wishing to use,
	* modify, copy, or redistribute it subject to the terms and conditions
	* of the GNU Lesser General Public License v.2.1.
	*
	* You should have received a copy of the GNU Lesser General Public License
	* along with this program; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	*/

	#include "lib.h"
	#include "filter.h"
	#include "activate.h"
	#ifdef UDEV_SYNC_SUPPORT
	#include <libudev.h>
	#include "dev-ext-udev-constants.h"
	#endif

	#ifdef __linux__

	#include <dirent.h>

	#define MPATH_PREFIX "mpath-"

	static const char _get_sysfs_name(struct device dev)
	{
	const char *name;

	if (!(name = strrchr(dev_name(dev), '/'))) {
	log_error("Cannot find '/' in device name.");
	return NULL;
	}
	name++;

	if (!*name) {
	log_error("Device name is not valid.");
	return NULL;
	}

	return name;
	}

	static const char _get_sysfs_name_by_devt(const char sysfs_dir, dev_t devno,
	char *buf, size_t buf_size)
	{
	const char *name;
	char path[PATH_MAX];
	int size;

	if (dm_snprintf(path, sizeof(path), "%s/dev/block/%d:%d", sysfs_dir,
	(int) MAJOR(devno), (int) MINOR(devno)) < 0) {
	log_error("Sysfs path string is too long.");
	return NULL;
	}

	if ((size = readlink(path, buf, buf_size - 1)) < 0) {
	log_sys_error("readlink", path);
	return NULL;
	}
	buf[size] = '\0';

	if (!(name = strrchr(buf, '/'))) {
	log_error("Cannot find device name in sysfs path.");
	return NULL;
	}
	name++;

	return name;
	}

	static int _get_sysfs_string(const char path, char buffer, int max_size)
	{
	FILE *fp;
	int r = 0;

	if (!(fp = fopen(path, "r"))) {
	log_sys_error("fopen", path);
	return 0;
	}

	if (!fgets(buffer, max_size, fp))
	log_sys_error("fgets", path);
	else
	r = 1;

	if (fclose(fp))
	log_sys_error("fclose", path);

	return r;
	}

	static int _get_sysfs_get_major_minor(const char sysfs_dir, const char kname, int major, int minor)
	{
	char path[PATH_MAX], buffer[64];

	if (dm_snprintf(path, sizeof(path), "%s/block/%s/dev", sysfs_dir, kname) < 0) {
	log_error("Sysfs path string is too long.");
	return 0;
	}

	if (!_get_sysfs_string(path, buffer, sizeof(buffer)))
	return_0;

	if (sscanf(buffer, "%d:%d", major, minor) != 2) {
	log_error("Failed to parse major minor from %s", buffer);
	return 0;
	}

	return 1;
	}

	static int _get_parent_mpath(const char dir, char name, int max_size)
	{
	struct dirent *d;
	DIR *dr;
	int r = 0;

	if (!(dr = opendir(dir))) {
	log_sys_error("opendir", dir);
	return 0;
	}

	*name = '\0';
	while ((d = readdir(dr))) {
	if (!strcmp(d->d_name, ".") \|\| !strcmp(d->d_name, ".."))
	continue;

	/* There should be only one holder if it is multipath */
	if (*name) {
	r = 0;
	break;
	}

	strncpy(name, d->d_name, max_size);
	r = 1;
	}

	if (closedir(dr))
	log_sys_error("closedir", dir);

	return r;
	}

	#ifdef UDEV_SYNC_SUPPORT
	static int _udev_dev_is_mpath(struct device *dev)
	{
	const char *value;
	struct dev_ext *ext;

	if (!(ext = dev_ext_get(dev)))
	return_0;

	value = udev_device_get_property_value((struct udev_device *)ext->handle, DEV_EXT_UDEV_BLKID_TYPE);
	if (value && !strcmp(value, DEV_EXT_UDEV_BLKID_TYPE_MPATH))
	return 1;

	value = udev_device_get_property_value((struct udev_device *)ext->handle, DEV_EXT_UDEV_MPATH_DEVICE_PATH);
	if (value && !strcmp(value, "1"))
	return 1;

	return 0;
	}
	#else
	static int _udev_dev_is_mpath(struct device *dev)
	{
	return 0;
	}
	#endif

	static int _native_dev_is_mpath(struct dev_filter f, struct device dev)
	{
	struct dev_types dt = (struct dev_types ) f->private;
	const char part_name, name;
	struct stat info;
	char path[PATH_MAX], parent_name[PATH_MAX];
	const char *sysfs_dir = dm_sysfs_dir();
	int major = MAJOR(dev->dev);
	int minor = MINOR(dev->dev);
	dev_t primary_dev;

	/* Limit this filter only to SCSI devices */
	if (!major_is_scsi_device(dt, MAJOR(dev->dev)))
	return 0;

	switch (dev_get_primary_dev(dt, dev, &primary_dev)) {
	case 2: /* The dev is partition. */
	part_name = dev_name(dev); /* name of original dev for log_debug msg */
	if (!(name = _get_sysfs_name_by_devt(sysfs_dir, primary_dev, parent_name, sizeof(parent_name))))
	return_0;
	log_debug_devs("%s: Device is a partition, using primary "
	"device %s for mpath component detection",
	part_name, name);
	break;
	case 1: /* The dev is already a primary dev. Just continue with the dev. */
	if (!(name = _get_sysfs_name(dev)))
	return_0;
	break;
	default: /* 0, error. */
	log_error("Failed to get primary device for %d:%d.", major, minor);
	return 0;
	}

	if (dm_snprintf(path, sizeof(path), "%s/block/%s/holders", sysfs_dir, name) < 0) {
	log_error("Sysfs path to check mpath is too long.");
	return 0;
	}

	/* also will filter out partitions */
	if (stat(path, &info))
	return 0;

	if (!S_ISDIR(info.st_mode)) {
	log_error("Path %s is not a directory.", path);
	return 0;
	}

	if (!_get_parent_mpath(path, parent_name, sizeof(parent_name)))
	return 0;

	if (!_get_sysfs_get_major_minor(sysfs_dir, parent_name, &major, &minor))
	return_0;

	if (major != dt->device_mapper_major)
	return 0;

	return lvm_dm_prefix_check(major, minor, MPATH_PREFIX);
	}

	static int _dev_is_mpath(struct dev_filter f, struct device dev)
	{
	if (dev->ext.src == DEV_EXT_NONE)
	return _native_dev_is_mpath(f, dev);

	if (dev->ext.src == DEV_EXT_UDEV)
	return _udev_dev_is_mpath(dev);

	log_error(INTERNAL_ERROR "Missing hook for mpath recognition "
	"using external device info source %s", dev_ext_name(dev));

	return 0;
	}

	#define MSG_SKIPPING "%s: Skipping mpath component device"

	static int _ignore_mpath(struct dev_filter f, struct device dev)
	{
	if (_dev_is_mpath(f, dev) == 1) {
	if (dev->ext.src == DEV_EXT_NONE)
	log_debug_devs(MSG_SKIPPING, dev_name(dev));
	else
	log_debug_devs(MSG_SKIPPING " [%s:%p]", dev_name(dev),
	dev_ext_name(dev), dev->ext.handle);
	return 0;
	}

	return 1;
	}

	static void _destroy(struct dev_filter *f)
	{
	if (f->use_count)
	log_error(INTERNAL_ERROR "Destroying mpath filter while in use %u times.", f->use_count);

	dm_free(f);
	}

	struct dev_filter mpath_filter_create(struct dev_types dt)
	{
	const char *sysfs_dir = dm_sysfs_dir();
	struct dev_filter *f;

	if (!*sysfs_dir) {
	log_verbose("No proc filesystem found: skipping multipath filter");
	return NULL;
	}

	if (!(f = dm_zalloc(sizeof(*f)))) {
	log_error("mpath filter allocation failed");
	return NULL;
	}

	f->passes_filter = _ignore_mpath;
	f->destroy = _destroy;
	f->use_count = 0;
	f->private = dt;

	log_debug_devs("mpath filter initialised.");

	return f;
	}

	#else

	struct dev_filter mpath_filter_create(struct dev_types dt)
	{
	return NULL;
	}

	#endif