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lvm2/lib/device/dev-mpath.c
Zdenek Kabelac e59c84ca3a gcc: clean cast with -Wbad-function-cast
Makes gcc happier.
2024-05-14 17:59:26 +02:00

784 lines
19 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/activate/activate.h"
#include "lib/commands/toolcontext.h"
#include "lib/device/device_id.h"
#include "lib/datastruct/str_list.h"
#ifdef UDEV_SYNC_SUPPORT
#include <libudev.h>
#include "lib/device/dev-ext-udev-constants.h"
#endif
#include <dirent.h>
#include <ctype.h>
#define MPATH_PREFIX "mpath-"
/*
* This hash table keeps track of whether a given dm device
* is a mpath device or not.
*
* If dm-3 is an mpath device, then the constant "2" is stored in
* the hash table with the key of the dm minor number ("3" for dm-3).
* If dm-3 is not an mpath device, then the constant "1" is stored in
* the hash table with the key of the dm minor number.
*/
static struct dm_pool *_wwid_mem;
static struct dm_hash_table *_minor_hash_tab;
static struct dm_hash_table *_wwid_hash_tab;
static struct dm_list _ignored;
static struct dm_list _ignored_exceptions;
#define MAX_WWID_LINE 512
static void _read_blacklist_file(const char *path)
{
FILE *fp;
char line[MAX_WWID_LINE];
char wwid[MAX_WWID_LINE];
char *word;
int section_black = 0;
int section_exceptions = 0;
int found_quote;
int found_type;
int i, j;
if (!(fp = fopen(path, "r")))
return;
while (fgets(line, sizeof(line), fp)) {
word = NULL;
/* skip initial white space on the line */
for (i = 0; i < MAX_WWID_LINE; i++) {
if ((line[i] == '\n') || (line[i] == '\0'))
break;
if (isspace(line[i]))
continue;
word = &line[i];
break;
}
if (!word || word[0] == '#')
continue;
/* identify the start of the section we want to read */
if (strchr(word, '{')) {
if (!strncmp(word, "blacklist_exceptions", 20))
section_exceptions = 1;
else if (!strncmp(word, "blacklist", 9))
section_black = 1;
continue;
}
/* identify the end of the section we've been reading */
if (strchr(word, '}')) {
section_exceptions = 0;
section_black = 0;
continue;
}
/* skip lines that are not in a section we want */
if (!section_black && !section_exceptions)
continue;
/*
* read a wwid from the blacklist{_exceptions} section.
* does not recognize other non-wwid entries in the
* section, and skips those (should the entire mp
* config filtering be disabled if non-wwids are seen?
*/
if (!strstr(word, "wwid"))
continue;
i += 4; /* skip "wwid" */
/*
* copy wwid value from the line.
* the wwids copied here need to match the
* wwids read from /etc/multipath/wwids,
* which are matched to wwids from sysfs.
*/
memset(wwid, 0, sizeof(wwid));
found_quote = 0;
found_type = 0;
j = 0;
for (; i < MAX_WWID_LINE; i++) {
if ((line[i] == '\n') || (line[i] == '\0'))
break;
if (!j && isspace(line[i]))
continue;
if (isspace(line[i]))
break;
/* quotes around wwid are optional */
if ((line[i] == '"') && !found_quote) {
found_quote = 1;
continue;
}
/* second quote is end of wwid */
if ((line[i] == '"') && found_quote)
break;
/* exclude initial 3/2/1 for naa/eui/t10 */
if (!j && !found_type &&
((line[i] == '3') || (line[i] == '2') || (line[i] == '1'))) {
found_type = 1;
continue;
}
wwid[j] = line[i];
j++;
}
if (j < 8)
continue;
log_debug("multipath wwid %s in %s %s",
wwid, section_exceptions ? "blacklist_exceptions" : "blacklist", path);
if (section_exceptions) {
if (!str_list_add(_wwid_mem, &_ignored_exceptions, dm_pool_strdup(_wwid_mem, wwid)))
stack;
} else {
if (!str_list_add(_wwid_mem, &_ignored, dm_pool_strdup(_wwid_mem, wwid)))
stack;
}
}
if (fclose(fp))
stack;
}
static void _read_wwid_exclusions(void)
{
static const char _mpath_conf[] = "/etc/multipath/conf.d";
char path[PATH_MAX] = { 0 };
DIR *dir;
struct dirent *de;
struct dm_str_list *sl, *sl2;
int rem_count = 0;
_read_blacklist_file("/etc/multipath.conf");
if ((dir = opendir(_mpath_conf))) {
while ((de = readdir(dir))) {
if (de->d_name[0] == '.')
continue;
snprintf(path, sizeof(path), "%s/%s", _mpath_conf, de->d_name);
_read_blacklist_file(path);
}
if (closedir(dir))
log_sys_debug("closedir", _mpath_conf);
}
/* for each wwid in ignored_exceptions, remove it from ignored */
dm_list_iterate_items_safe(sl, sl2, &_ignored) {
if (str_list_match_item(&_ignored_exceptions, sl->str))
str_list_del(&_ignored, sl->str);
}
/* for each wwid in ignored, remove it from wwid_hash */
dm_list_iterate_items(sl, &_ignored) {
dm_hash_remove_binary(_wwid_hash_tab, sl->str, strlen(sl->str));
rem_count++;
}
if (rem_count)
log_debug("multipath config ignored %d wwids", rem_count);
}
static void _read_wwid_file(const char *config_wwids_file, int *entries)
{
FILE *fp;
char line[MAX_WWID_LINE];
char *wwid, *p;
char typestr[2] = { 0 };
int count = 0;
if (config_wwids_file[0] != '/') {
log_print_unless_silent("Ignoring unknown multipath_wwids_file.");
return;
}
if (!(fp = fopen(config_wwids_file, "r"))) {
log_debug("multipath wwids file not found");
return;
}
while (fgets(line, sizeof(line), fp)) {
if (line[0] == '#')
continue;
wwid = line;
if (line[0] == '/')
wwid++;
/*
* the initial character is the id type,
* 1 is t10, 2 is eui, 3 is naa, 8 is scsi name.
* wwids are stored in the hash table without the type charater.
* It seems that sometimes multipath does not include
* the type charater (seen with t10 scsi_debug devs).
*/
typestr[0] = *wwid;
if (typestr[0] == '1' || typestr[0] == '2' || typestr[0] == '3')
wwid++;
if ((p = strchr(wwid, '/')))
*p = '\0';
(void) dm_hash_insert_binary(_wwid_hash_tab, wwid, strlen(wwid), (void*)1);
count++;
}
if (fclose(fp))
stack;
log_debug("multipath wwids read %d from %s", count, config_wwids_file);
*entries = count;
}
int dev_mpath_init(const char *config_wwids_file)
{
struct dm_pool *mem;
struct dm_hash_table *minor_tab;
struct dm_hash_table *wwid_tab;
int entries = 0;
dm_list_init(&_ignored);
dm_list_init(&_ignored_exceptions);
if (!(mem = dm_pool_create("mpath", 256))) {
log_error("mpath pool creation failed.");
return 0;
}
if (!(minor_tab = dm_hash_create(110))) {
log_error("mpath hash table creation failed.");
dm_pool_destroy(mem);
return 0;
}
_wwid_mem = mem;
_minor_hash_tab = minor_tab;
/* multipath_wwids_file="" disables the use of the file */
if (config_wwids_file && !strlen(config_wwids_file)) {
log_debug("multipath wwids file disabled.");
return 1;
}
if (!(wwid_tab = dm_hash_create(110))) {
log_error("mpath hash table creation failed.");
dm_hash_destroy(_minor_hash_tab);
dm_pool_destroy(_wwid_mem);
_minor_hash_tab = NULL;
_wwid_mem = NULL;
return 0;
}
_wwid_hash_tab = wwid_tab;
if (config_wwids_file) {
_read_wwid_file(config_wwids_file, &entries);
_read_wwid_exclusions();
}
if (!entries) {
/* reading dev wwids is skipped with null wwid_hash_tab */
dm_hash_destroy(_wwid_hash_tab);
_wwid_hash_tab = NULL;
}
return 1;
}
void dev_mpath_exit(void)
{
if (_minor_hash_tab)
dm_hash_destroy(_minor_hash_tab);
if (_wwid_hash_tab)
dm_hash_destroy(_wwid_hash_tab);
if (_wwid_mem)
dm_pool_destroy(_wwid_mem);
_minor_hash_tab = NULL;
_wwid_hash_tab = NULL;
_wwid_mem = NULL;
}
/*
* given "/dev/foo" return "foo"
*/
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;
}
/*
* given major:minor
* readlink translates /sys/dev/block/major:minor to /sys/.../foo
* from /sys/.../foo return "foo"
*/
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), "%sdev/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_dm_mpath(struct dev_types *dt, const char *sysfs_dir, const char *holder_name)
{
char path[PATH_MAX];
char buffer[128];
if (dm_snprintf(path, sizeof(path), "%sblock/%s/dm/uuid", sysfs_dir, holder_name) < 0) {
log_error("Sysfs path string is too long.");
return 0;
}
buffer[0] = '\0';
if (!_get_sysfs_string(path, buffer, sizeof(buffer)))
return_0;
if (!strncmp(buffer, MPATH_PREFIX, 6))
return 1;
return 0;
}
#ifdef UDEV_SYNC_SUPPORT
static int _dev_is_mpath_component_udev(struct device *dev)
{
const char *value;
struct dev_ext *ext;
/*
* external_device_info_source="udev" enables these udev checks.
* external_device_info_source="none" disables them.
*/
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 _dev_is_mpath_component_udev(struct device *dev)
{
return 0;
}
#endif
/* mpath_devno is major:minor of the dm multipath device currently using the component dev. */
static int _dev_is_mpath_component_sysfs(struct cmd_context *cmd, struct device *dev,
int primary_result, dev_t primary_dev, dev_t *mpath_devno)
{
struct dev_types *dt = cmd->dev_types;
const char *name; /* e.g. "sda" for "/dev/sda" */
char link_path[PATH_MAX]; /* some obscure, unpredictable sysfs path */
char holders_path[PATH_MAX]; /* e.g. "/sys/block/sda/holders/" */
char dm_dev_path[PATH_MAX]; /* e.g. "/dev/dm-1" */
char *holder_name; /* e.g. "dm-1" */
const char *sysfs_dir = dm_sysfs_dir();
DIR *dr;
struct dirent *de;
int dev_major = MAJOR(dev->dev);
int dev_minor = MINOR(dev->dev);
unsigned dm_dev_major;
unsigned dm_dev_minor;
struct stat info;
int is_mpath_component = 0;
switch (primary_result) {
case 2: /* The dev is partition. */
/* gets "foo" for "/dev/foo" where "/dev/foo" comes from major:minor */
if (!(name = _get_sysfs_name_by_devt(sysfs_dir, primary_dev, link_path, sizeof(link_path))))
return_0;
break;
case 1: /* The dev is already a primary dev. Just continue with the dev. */
/* gets "foo" for "/dev/foo" */
if (!(name = _get_sysfs_name(dev)))
return_0;
break;
default: /* 0, error. */
log_warn("Failed to get primary device for %d:%d.", dev_major, dev_minor);
return 0;
}
if (dm_snprintf(holders_path, sizeof(holders_path), "%sblock/%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(holders_path, &info))
return 0;
if (!S_ISDIR(info.st_mode)) {
log_warn("Path %s is not a directory.", holders_path);
return 0;
}
/*
* If any holder is a dm mpath device, then return 1;
*/
if (!(dr = opendir(holders_path))) {
log_debug("Device %s has no holders dir", dev_name(dev));
return 0;
}
while ((de = readdir(dr))) {
if (!strcmp(de->d_name, ".") || !strcmp(de->d_name, ".."))
continue;
/*
* holder_name is e.g. "dm-1"
* dm_dev_path is then e.g. "/dev/dm-1"
*/
holder_name = de->d_name;
if (dm_snprintf(dm_dev_path, sizeof(dm_dev_path), "%s/%s", cmd->dev_dir, holder_name) < 0) {
log_warn("dm device path to check mpath is too long.");
continue;
}
/*
* stat "/dev/dm-1" which is the holder of the dev we're checking
* dm_dev_major:dm_dev_minor come from stat("/dev/dm-1")
*/
if (stat(dm_dev_path, &info)) {
log_debug_devs("dev_is_mpath_component %s holder %s stat result %d",
dev_name(dev), dm_dev_path, errno);
continue;
}
dm_dev_major = MAJOR(info.st_rdev);
dm_dev_minor = MINOR(info.st_rdev);
if (dm_dev_major != dt->device_mapper_major) {
log_debug_devs("dev_is_mpath_component %s holder %s %d:%d does not have dm major",
dev_name(dev), dm_dev_path, dm_dev_major, dm_dev_minor);
continue;
}
/*
* A previous call may have checked if dm_dev_minor is mpath and saved
* the result in the hash table. If there's a saved result just use that.
*
* The minor number of "/dev/dm-1" is added to the hash table with
* const value 2 meaning that dm minor 1 (for /dev/dm-1) is a multipath dev
* and const value 1 meaning that dm minor 1 is not a multipath dev.
*/
if (_minor_hash_tab) {
void *d = dm_hash_lookup_binary(_minor_hash_tab, &dm_dev_minor, sizeof(dm_dev_minor));
long look = (long) d;
if (look > 0) {
log_debug_devs("dev_is_mpath_component %s holder %s %u:%u already checked as %sbeing mpath.",
dev_name(dev), holder_name, dm_dev_major, dm_dev_minor, (look > 1) ? "" : "not ");
is_mpath_component = (look == 2);
goto out;
}
/* no saved result for dm_dev_minor, so check the uuid for it */
}
/*
* Returns 1 if /sys/block/<holder_name>/dm/uuid indicates that
* <holder_name> is a dm device with dm uuid prefix mpath-.
* When true, <holder_name> will be something like "dm-1".
*/
if (_get_sysfs_dm_mpath(dt, sysfs_dir, holder_name)) {
log_debug_devs("dev_is_mpath_component %s holder %s %u:%u ignore mpath component",
dev_name(dev), holder_name, dm_dev_major, dm_dev_minor);
/* For future checks, save that the dm minor refers to mpath ("2" == is mpath) */
if (_minor_hash_tab)
(void) dm_hash_insert_binary(_minor_hash_tab, &dm_dev_minor, sizeof(dm_dev_minor), (void*)2);
is_mpath_component = 1;
goto out;
}
/* For future checks, save that the dm minor does not refer to mpath ("1" == is not mpath) */
if (_minor_hash_tab)
(void) dm_hash_insert_binary(_minor_hash_tab, &dm_dev_minor, sizeof(dm_dev_minor), (void*)1);
}
out:
if (closedir(dr))
log_sys_debug("closedir", holders_path);
if (is_mpath_component)
*mpath_devno = MKDEV(dm_dev_major, dm_dev_minor);
return is_mpath_component;
}
static int _dev_in_wwid_file(struct cmd_context *cmd, struct device *dev,
int primary_result, dev_t primary_dev)
{
char idbuf[DEV_WWID_SIZE] = { 0 };
struct dev_wwid *dw;
char *wwid, *full_wwid;
if (!_wwid_hash_tab)
return 0;
/*
* Check the primary device, not the partition.
*/
if (primary_result == 2) {
if (!(dev = dev_cache_get_by_devt(cmd, primary_dev))) {
log_debug("dev_is_mpath_component %s no primary dev", dev_name(dev));
return 0;
}
}
/*
* sysfs wwid uses format: naa.<value>, eui.<value>, t10.<value>.
* multipath wwids file uses format: 3<value>, 2<value>, 1<value>.
*
* We omit the type prefix before looking up. The multipath/wwids
* values in the wwid_hash_tab have the initial character removed.
*
* There's no type prefix for "scsi name string" type 8 ids.
*
* First try looking up any wwids that have already been read.
*/
lookup:
dm_list_iterate_items(dw, &dev->wwids) {
if (dw->type == 1 || dw->type == 2 || dw->type == 3)
wwid = &dw->id[4];
else
wwid = dw->id;
if (dm_hash_lookup_binary(_wwid_hash_tab, wwid, strlen(wwid))) {
full_wwid = dw->id;
goto found;
}
}
/*
* The id from sysfs wwid may not be the id used by multipath,
* or a device may not have a vpd_pg83 file (e.g. nvme).
*/
if (!(dev->flags & DEV_ADDED_VPD_WWIDS) && dev_read_vpd_wwids(cmd, dev))
goto lookup;
if (!(dev->flags & DEV_ADDED_SYS_WWID) && dev_read_sys_wwid(cmd, dev, idbuf, sizeof(idbuf), &dw)) {
if (dw->type == 1 || dw->type == 2 || dw->type == 3)
wwid = &dw->id[4];
else
wwid = dw->id;
if (dm_hash_lookup_binary(_wwid_hash_tab, wwid, strlen(wwid))) {
full_wwid = dw->id;
goto found;
}
}
return 0;
found:
log_debug_devs("dev_is_mpath_component %s %s in wwids file", dev_name(dev), full_wwid);
return 1;
}
int dev_is_mpath_component(struct cmd_context *cmd, struct device *dev, dev_t *holder_devno)
{
struct dev_types *dt = cmd->dev_types;
int primary_result;
dev_t primary_dev;
/*
* multipath only uses SCSI or NVME devices
*/
if (!major_is_scsi_device(dt, MAJOR(dev->dev)) && !dev_is_nvme(dt, dev))
return 0;
/*
* primary_result 2: dev is a partition, primary_dev is the whole device
* primary_result 1: dev is a whole device
*/
if (!(primary_result = dev_get_primary_dev(dt, dev, &primary_dev)))
return_0;
if (_dev_is_mpath_component_sysfs(cmd, dev, primary_result, primary_dev, holder_devno) == 1)
goto found;
if (_dev_in_wwid_file(cmd, dev, primary_result, primary_dev))
goto found;
if (external_device_info_source() == DEV_EXT_UDEV) {
if (_dev_is_mpath_component_udev(dev) == 1)
goto found;
}
/*
* TODO: save the result of this function in dev->flags and use those
* flags on repeated calls to avoid repeating the work multiple times
* for the same device when there are partitions on the device.
*/
return 0;
found:
return 1;
}
const char *dev_mpath_component_wwid(struct cmd_context *cmd, struct device *dev)
{
char slaves_path[PATH_MAX];
char wwid_path[PATH_MAX];
char sysbuf[PATH_MAX] = { 0 };
char *slave_name;
const char *wwid = NULL;
DIR *dr;
struct dirent *de;
/* /sys/dev/block/253:7/slaves/sda/device/wwid */
if (dm_snprintf(slaves_path, sizeof(slaves_path), "%sdev/block/%d:%d/slaves",
dm_sysfs_dir(), (int)MAJOR(dev->dev), (int)MINOR(dev->dev)) < 0) {
log_warn("Sysfs path to check mpath components is too long.");
return NULL;
}
/* Get wwid from first component */
if (!(dr = opendir(slaves_path))) {
if (errno == ENOTDIR)
log_warn("WARNING: Path %s is not a directory.", slaves_path);
else if (errno != ENOENT)
log_sys_debug("opendir", slaves_path);
return NULL;
}
while ((de = readdir(dr))) {
if (!strcmp(de->d_name, ".") || !strcmp(de->d_name, ".."))
continue;
/* slave_name "sda" */
slave_name = de->d_name;
/* read /sys/block/sda/device/wwid */
if (dm_snprintf(wwid_path, sizeof(wwid_path), "%sblock/%s/device/wwid",
dm_sysfs_dir(), slave_name) < 0) {
log_warn("Failed to create sysfs wwid path for %s", slave_name);
continue;
}
if (!get_sysfs_value(wwid_path, sysbuf, sizeof(sysbuf), 0))
stack;
if (!sysbuf[0])
continue;
if (strstr(sysbuf, "scsi_debug")) {
unsigned i;
for (i = 0; i < strlen(sysbuf); i++) {
if (sysbuf[i] == ' ')
sysbuf[i] = '_';
}
}
if ((wwid = dm_pool_strdup(cmd->mem, sysbuf)))
break;
}
if (closedir(dr))
log_sys_debug("closedir", slaves_path);
return wwid;
}