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mirror of git://sourceware.org/git/lvm2.git synced 2024-12-22 17:35:59 +03:00
lvm2/lib/filters/filter-mpath.c
David Teigland 450f272b31 devices: support printing the filter that rejects a device
Use of this new message function needs to be added
to various commands to improve the output.
2020-10-01 12:00:09 -05:00

363 lines
8.2 KiB
C

/*
* 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 "base/memory/zalloc.h"
#include "lib/misc/lib.h"
#include "lib/filters/filter.h"
#include "lib/activate/activate.h"
#ifdef UDEV_SYNC_SUPPORT
#include <libudev.h>
#include "lib/device/dev-ext-udev-constants.h"
#endif
#ifdef __linux__
#include <dirent.h>
#define MPATH_PREFIX "mpath-"
struct mpath_priv {
struct dm_pool *mem;
struct dev_filter f;
struct dev_types *dt;
struct dm_hash_table *hash;
};
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 mpath_priv *mp = (struct mpath_priv *) f->private;
struct dev_types *dt = mp->dt;
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;
long look;
/* 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_warn("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_warn("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_warn("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;
/* Avoid repeated detection of multipath device and use first checked result */
look = (long) dm_hash_lookup_binary(mp->hash, &minor, sizeof(minor));
if (look > 0) {
log_debug_devs("%s(%u:%u): already checked as %sbeing mpath.",
parent_name, major, minor, (look > 1) ? "" : "not ");
return (look > 1) ? 1 : 0;
}
if (lvm_dm_prefix_check(major, minor, MPATH_PREFIX)) {
(void) dm_hash_insert_binary(mp->hash, &minor, sizeof(minor), (void*)2);
return 1;
}
(void) dm_hash_insert_binary(mp->hash, &minor, sizeof(minor), (void*)1);
return 0;
}
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 cmd_context *cmd, struct dev_filter *f, struct device *dev, const char *use_filter_name)
{
dev->filtered_flags &= ~DEV_FILTERED_MPATH_COMPONENT;
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);
dev->filtered_flags |= DEV_FILTERED_MPATH_COMPONENT;
return 0;
}
return 1;
}
static void _destroy(struct dev_filter *f)
{
struct mpath_priv *mp = (struct mpath_priv*) f->private;
if (f->use_count)
log_error(INTERNAL_ERROR "Destroying mpath filter while in use %u times.", f->use_count);
dm_hash_destroy(mp->hash);
dm_pool_destroy(mp->mem);
}
struct dev_filter *mpath_filter_create(struct dev_types *dt)
{
const char *sysfs_dir = dm_sysfs_dir();
struct dm_pool *mem;
struct mpath_priv *mp;
struct dm_hash_table *hash;
if (!*sysfs_dir) {
log_verbose("No proc filesystem found: skipping multipath filter");
return NULL;
}
if (!(hash = dm_hash_create(128))) {
log_error("mpath hash table creation failed.");
return NULL;
}
if (!(mem = dm_pool_create("mpath", 256))) {
log_error("mpath pool creation failed.");
dm_hash_destroy(hash);
return NULL;
}
if (!(mp = dm_pool_zalloc(mem, sizeof(*mp)))) {
log_error("mpath filter allocation failed.");
goto bad;
}
if (!(mp = dm_pool_zalloc(mem, sizeof(*mp)))) {
log_error("mpath filter allocation failed.");
goto bad;
}
mp->f.passes_filter = _ignore_mpath;
mp->f.destroy = _destroy;
mp->f.use_count = 0;
mp->f.private = mp;
mp->f.name = "mpath";
mp->mem = mem;
mp->dt = dt;
mp->hash = hash;
log_debug_devs("mpath filter initialised.");
return &mp->f;
bad:
dm_pool_destroy(mem);
dm_hash_destroy(hash);
return NULL;
}
#else
struct dev_filter *mpath_filter_create(struct dev_types *dt)
{
return NULL;
}
#endif