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lvm2/lib/device/device_id.c
David Teigland 0eebd9d780 vgimportdevices: fix locking when creating devices file 
Take the devices file lock before creating a new devices file.
(Was missed by the change to preemptively create the devices
file prior to setup_devices(), which was done to improve the
error path.)
2022-08-30 14:52:00 -05:00

2578 lines
71 KiB
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/*
* Copyright (C) 2020 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/commands/toolcontext.h"
#include "lib/device/device.h"
#include "lib/device/device_id.h"
#include "lib/device/dev-type.h"
#include "lib/label/label.h"
#include "lib/metadata/metadata.h"
#include "lib/format_text/layout.h"
#include "lib/cache/lvmcache.h"
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <time.h>
#include <sys/types.h>
#include <sys/file.h>
#include <sys/sysmacros.h>
#define DEVICES_FILE_MAJOR 1
#define DEVICES_FILE_MINOR 1
#define VERSION_LINE_MAX 256
static int _devices_fd = -1;
static int _using_devices_file;
static int _devices_file_locked;
static char _devices_lockfile[PATH_MAX];
static char _devices_file_systemid[PATH_MAX];
static char _devices_file_version[VERSION_LINE_MAX];
static const char *_searched_file = DEFAULT_RUN_DIR "/searched_devnames";
char *devices_file_version(void)
{
return _devices_file_version;
}
/*
* cmd->devicesfile is set when using a non-system devices file,
* and at least for now, the searched_devnames optimization
* only applies to the system devices file.
*/
static void _touch_searched_devnames(struct cmd_context *cmd)
{
FILE *fp;
if (cmd->devicesfile)
return;
if (!(fp = fopen(_searched_file, "w")))
return;
if (fclose(fp))
stack;
}
void unlink_searched_devnames(struct cmd_context *cmd)
{
if (cmd->devicesfile)
return;
if (unlink(_searched_file))
log_debug("unlink %s errno %d", _searched_file, errno);
else
log_debug("unlink %s", _searched_file);
}
static int _searched_devnames_exists(struct cmd_context *cmd)
{
struct stat buf;
if (cmd->devicesfile)
return 0;
if (!stat(_searched_file, &buf))
return 1;
if (errno != ENOENT)
log_debug("stat %s errno %d", _searched_file, errno);
return 0;
}
/*
* How the devices file and device IDs are used by an ordinary command:
*
* 1. device_ids_read() reads the devices file, and adds a 'struct dev_use'
* to cmd->use_devices for each entry. These are the devices lvm
* can use, but we do not yet know which devnames they correspond to.
* 2. dev_cache_scan() gets a list of all devices (devnames) on the system,
* and adds a 'struct device' to dev-cache for each.
* 3. device_ids_match() matches du entries from the devices file
* with devices from dev-cache. With this complete, we know the
* devnames to use for each of the entries in the devices file.
* 4. label_scan (or equivalent) iterates through all devices in
* dev-cache, checks each one with filters, which excludes many,
* and reads lvm headers and metadata from the devs that pass the
* filters. lvmcache is populated with summary info about each PV
* during this phase.
* 5. device_ids_validate() checks if the PVIDs saved in the devices
* file are correct based on the PVIDs read from disk in the
* previous step. If not it updates the devices file.
*
* cmd->use_devices reflect the entries in the devices file.
* When reading the devices file, a 'du' struct is added to use_devices
* for each entry.
* When adding devices to the devices file, a new du struct is added
* to use_devices, and then a new file entry is written for each du.
*
* After reading the devices file, we want to match each du from
* the file to an actual device on the system. We look at struct device's
* in dev-cache to find one that matches each du, based on the device_id.
* When a match is made, du->dev is set, and DEV_MATCHED_USE_ID is set
* in the dev.
*
* After the use_devices entries are matched to system devices,
* label_scan can be called to filter and scan devices. After
* label_scan, device_ids_validate() is called to check if the
* PVID read from each device matches the PVID recorded in the
* devices file for the device.
*
* A device can have multiple device IDs, e.g. a dev could have
* both a wwid and a serial number, but only one of these IDs is
* used as the device ID in the devices file, e.g. the wwid is
* preferred so that would be used in the devices file.
* Each of the different types of device IDs can be saved in
* dev->ids list (struct dev_id). So, one dev may have multiple
* entries in dev->ids, e.g. one for wwid and one for serial.
* The dev_id struct that is actually being used for the device
* is set in dev->id.
* The reason for saving multiple IDs in dev->ids is because
* the process of matching devs to devices file entries can
* involve repeatedly checking other dev_id types for a given
* device, so we save each type as it is read to avoid rereading
* the same id type many times.
*/
void free_du(struct dev_use *du)
{
free(du->idname);
free(du->devname);
free(du->pvid);
free(du);
}
void free_dus(struct dm_list *dus)
{
struct dev_use *du, *safe;
dm_list_iterate_items_safe(du, safe, dus) {
dm_list_del(&du->list);
free_du(du);
}
}
void free_did(struct dev_id *id)
{
free(id->idname);
free(id);
}
void free_dids(struct dm_list *ids)
{
struct dev_id *id, *safe;
dm_list_iterate_items_safe(id, safe, ids) {
dm_list_del(&id->list);
free_did(id);
}
}
static int _read_sys_block(struct cmd_context *cmd, struct device *dev,
const char *suffix, char *sysbuf, int sysbufsize,
int binary, int *retlen)
{
char path[PATH_MAX];
dev_t devt = dev->dev;
dev_t prim = 0;
int ret;
retry:
if (dm_snprintf(path, sizeof(path), "%sdev/block/%d:%d/%s",
dm_sysfs_dir(), (int)MAJOR(devt), (int)MINOR(devt), suffix) < 0) {
log_error("Failed to create sysfs path for %s", dev_name(dev));
return 0;
}
if (binary) {
ret = get_sysfs_binary(path, sysbuf, sysbufsize, retlen);
if (ret && !*retlen)
ret = 0;
} else {
ret = get_sysfs_value(path, sysbuf, sysbufsize, 0);
if (ret && !sysbuf[0])
ret = 0;
}
if (ret) {
sysbuf[sysbufsize - 1] = '\0';
return 1;
}
if (prim)
goto fail;
/* in case it failed because dev is a partition... */
ret = dev_get_primary_dev(cmd->dev_types, dev, &prim);
if (ret == 2) {
devt = prim;
goto retry;
}
fail:
return 0;
}
int read_sys_block(struct cmd_context *cmd, struct device *dev,
const char *suffix, char *sysbuf, int sysbufsize)
{
return _read_sys_block(cmd, dev, suffix, sysbuf, sysbufsize, 0, NULL);
}
int read_sys_block_binary(struct cmd_context *cmd, struct device *dev,
const char *suffix, char *sysbuf, int sysbufsize,
int *retlen)
{
return _read_sys_block(cmd, dev, suffix, sysbuf, sysbufsize, 1, retlen);
}
static int _dm_uuid_has_prefix(char *sysbuf, const char *prefix)
{
if (!strncmp(sysbuf, prefix, strlen(prefix)))
return 1;
/*
* If it's a kpartx partitioned dm device the dm uuid will
* be part%d-<prefix>... e.g. part1-mpath-abc...
* Check for the prefix after the part%-
*/
if (!strncmp(sysbuf, "part", 4)) {
const char *dash = strchr(sysbuf, '-');
if (!dash)
return 0;
if (!strncmp(dash + 1, prefix, strlen(prefix)))
return 1;
}
return 0;
}
/* the dm uuid uses the wwid of the underlying dev */
int dev_has_mpath_uuid(struct cmd_context *cmd, struct device *dev, const char **idname_out)
{
char sysbuf[PATH_MAX] = { 0 };
const char *idname;
if (!read_sys_block(cmd, dev, "dm/uuid", sysbuf, sizeof(sysbuf)))
return 0;
if (!_dm_uuid_has_prefix(sysbuf, "mpath-"))
return 0;
if (!idname_out)
return 1;
if (!(idname = strdup(sysbuf)))
return_0;
*idname_out = idname;
return 1;
}
static int _dev_has_crypt_uuid(struct cmd_context *cmd, struct device *dev, const char **idname_out)
{
char sysbuf[PATH_MAX] = { 0 };
const char *idname;
if (!read_sys_block(cmd, dev, "dm/uuid", sysbuf, sizeof(sysbuf)))
return 0;
if (!_dm_uuid_has_prefix(sysbuf, "CRYPT-"))
return 0;
if (!idname_out)
return 1;
if (!(idname = strdup(sysbuf)))
return_0;
*idname_out = idname;
return 1;
}
static int _dev_has_lvmlv_uuid(struct cmd_context *cmd, struct device *dev, const char **idname_out)
{
char sysbuf[PATH_MAX] = { 0 };
const char *idname;
if (!read_sys_block(cmd, dev, "dm/uuid", sysbuf, sizeof(sysbuf)))
return 0;
if (!_dm_uuid_has_prefix(sysbuf, "LVM-"))
return 0;
if (!idname_out)
return 1;
if (!(idname = strdup(sysbuf)))
return_0;
*idname_out = idname;
return 1;
}
const char *device_id_system_read(struct cmd_context *cmd, struct device *dev, uint16_t idtype)
{
char sysbuf[PATH_MAX] = { 0 };
const char *idname = NULL;
int i;
if (idtype == DEV_ID_TYPE_SYS_WWID) {
read_sys_block(cmd, dev, "device/wwid", sysbuf, sizeof(sysbuf));
if (!sysbuf[0])
read_sys_block(cmd, dev, "wwid", sysbuf, sizeof(sysbuf));
/* qemu wwid begins "t10.ATA QEMU HARDDISK ..." */
if (strstr(sysbuf, "QEMU HARDDISK"))
sysbuf[0] = '\0';
}
else if (idtype == DEV_ID_TYPE_SYS_SERIAL)
read_sys_block(cmd, dev, "device/serial", sysbuf, sizeof(sysbuf));
else if (idtype == DEV_ID_TYPE_MPATH_UUID) {
read_sys_block(cmd, dev, "dm/uuid", sysbuf, sizeof(sysbuf));
/* if (strncmp(sysbuf, "mpath", 5)) sysbuf[0] = '\0'; */
}
else if (idtype == DEV_ID_TYPE_CRYPT_UUID) {
read_sys_block(cmd, dev, "dm/uuid", sysbuf, sizeof(sysbuf));
/* if (strncmp(sysbuf, "CRYPT", 5)) sysbuf[0] = '\0'; */
}
else if (idtype == DEV_ID_TYPE_LVMLV_UUID) {
read_sys_block(cmd, dev, "dm/uuid", sysbuf, sizeof(sysbuf));
/* if (strncmp(sysbuf, "LVM", 3)) sysbuf[0] = '\0'; */
}
else if (idtype == DEV_ID_TYPE_MD_UUID) {
read_sys_block(cmd, dev, "md/uuid", sysbuf, sizeof(sysbuf));
}
else if (idtype == DEV_ID_TYPE_LOOP_FILE) {
read_sys_block(cmd, dev, "loop/backing_file", sysbuf, sizeof(sysbuf));
/* if backing file is deleted, fall back to devname */
if (strstr(sysbuf, "(deleted)"))
sysbuf[0] = '\0';
}
else if (idtype == DEV_ID_TYPE_DEVNAME) {
if (dm_list_empty(&dev->aliases))
goto_bad;
if (!(idname = strdup(dev_name(dev))))
goto_bad;
return idname;
}
for (i = 0; i < strlen(sysbuf); i++) {
if (isblank(sysbuf[i]) || isspace(sysbuf[i]) || iscntrl(sysbuf[i]))
sysbuf[i] = '_';
}
if (!sysbuf[0])
goto_bad;
if (!(idname = strdup(sysbuf)))
goto_bad;
return idname;
bad:
return NULL;
}
/*
* Check if this dev would use a stable idtype or if it
* would use DEV_ID_TYPE_DEVNAME.
*/
static int _dev_has_stable_id(struct cmd_context *cmd, struct device *dev)
{
char sysbuf[PATH_MAX] = { 0 };
struct dev_id *id;
const char *idname;
/*
* An idtype other than DEVNAME is stable, i.e. it doesn't change after
* reboot or device reattach.
* An id on dev->ids with idtype set and !idname means that idtype does
* not exist for the dev. (Optimization to avoid repeated negative
* system_read.)
*/
dm_list_iterate_items(id, &dev->ids) {
if ((id->idtype != DEV_ID_TYPE_DEVNAME) && id->idname)
return 1;
}
/*
* Use device_id_system_read() instead of read_sys_block() when
* system_read ignores some values from sysfs.
*/
if ((idname = device_id_system_read(cmd, dev, DEV_ID_TYPE_SYS_WWID))) {
free((void*)idname);
return 1;
}
if ((idname = device_id_system_read(cmd, dev, DEV_ID_TYPE_SYS_SERIAL))) {
free((void*)idname);
return 1;
}
if ((MAJOR(dev->dev) == cmd->dev_types->loop_major) &&
(idname = device_id_system_read(cmd, dev, DEV_ID_TYPE_LOOP_FILE))) {
free((void*)idname);
return 1;
}
if ((MAJOR(dev->dev) == cmd->dev_types->device_mapper_major)) {
if (!read_sys_block(cmd, dev, "dm/uuid", sysbuf, sizeof(sysbuf)))
goto_out;
if (_dm_uuid_has_prefix(sysbuf, "mpath-"))
return 1;
if (_dm_uuid_has_prefix(sysbuf, "CRYPT-"))
return 1;
if (_dm_uuid_has_prefix(sysbuf, "LVM-"))
return 1;
}
if ((MAJOR(dev->dev) == cmd->dev_types->md_major) &&
read_sys_block(cmd, dev, "md/uuid", sysbuf, sizeof(sysbuf)))
return 1;
out:
/* DEV_ID_TYPE_DEVNAME would be used for this dev. */
return 0;
}
const char *idtype_to_str(uint16_t idtype)
{
if (idtype == DEV_ID_TYPE_SYS_WWID)
return "sys_wwid";
if (idtype == DEV_ID_TYPE_SYS_SERIAL)
return "sys_serial";
if (idtype == DEV_ID_TYPE_DEVNAME)
return "devname";
if (idtype == DEV_ID_TYPE_MPATH_UUID)
return "mpath_uuid";
if (idtype == DEV_ID_TYPE_CRYPT_UUID)
return "crypt_uuid";
if (idtype == DEV_ID_TYPE_LVMLV_UUID)
return "lvmlv_uuid";
if (idtype == DEV_ID_TYPE_MD_UUID)
return "md_uuid";
if (idtype == DEV_ID_TYPE_LOOP_FILE)
return "loop_file";
return "unknown";
}
uint16_t idtype_from_str(const char *str)
{
if (!strcmp(str, "sys_wwid"))
return DEV_ID_TYPE_SYS_WWID;
if (!strcmp(str, "sys_serial"))
return DEV_ID_TYPE_SYS_SERIAL;
if (!strcmp(str, "devname"))
return DEV_ID_TYPE_DEVNAME;
if (!strcmp(str, "mpath_uuid"))
return DEV_ID_TYPE_MPATH_UUID;
if (!strcmp(str, "crypt_uuid"))
return DEV_ID_TYPE_CRYPT_UUID;
if (!strcmp(str, "lvmlv_uuid"))
return DEV_ID_TYPE_LVMLV_UUID;
if (!strcmp(str, "md_uuid"))
return DEV_ID_TYPE_MD_UUID;
if (!strcmp(str, "loop_file"))
return DEV_ID_TYPE_LOOP_FILE;
return 0;
}
const char *dev_idtype_for_metadata(struct cmd_context *cmd, struct device *dev)
{
const char *str;
if (!cmd->enable_devices_file)
return NULL;
if (!dev || !dev->id || !dev->id->idtype || (dev->id->idtype == DEV_ID_TYPE_DEVNAME))
return NULL;
str = idtype_to_str(dev->id->idtype);
if (!strcmp(str, "unknown"))
return NULL;
return str;
}
const char *dev_idname_for_metadata(struct cmd_context *cmd, struct device *dev)
{
if (!cmd->enable_devices_file)
return NULL;
if (!dev || !dev->id || !dev->id->idtype || (dev->id->idtype == DEV_ID_TYPE_DEVNAME))
return NULL;
return dev->id->idname;
}
static void _copy_idline_str(char *src, char *dst, int len)
{
char *s, *d = dst;
memset(dst, 0, len);
if (!(s = strchr(src, '=')))
return;
s++;
while ((*s == ' ') && (s < src + len))
s++;
while ((*s != ' ') && (*s != '\0') && (*s != '\n') && (s < src + len)) {
*d = *s;
s++;
d++;
}
dst[len-1] = '\0';
}
int device_ids_read(struct cmd_context *cmd)
{
char line[PATH_MAX];
char buf[PATH_MAX];
char *idtype, *idname, *devname, *pvid, *part;
struct dev_use *du;
FILE *fp;
int line_error;
int ret = 1;
if (!cmd->enable_devices_file)
return 1;
/*
* The use_devices list should rarely if ever be non-empty at this
* point, it means device_ids_read has been called twice.
* If we wanted to redo reading the file, we'd need to
* free_dus(&cmd->use_devices) and clear the MATCHED_USE_ID flag in all
* dev->flags.
*/
if (!dm_list_empty(&cmd->use_devices)) {
log_debug("device_ids_read already done");
return 1;
}
log_debug("device_ids_read %s", cmd->devices_file_path);
if (!(fp = fopen(cmd->devices_file_path, "r"))) {
log_warn("Cannot open devices file to read.");
return 0;
}
while (fgets(line, sizeof(line), fp)) {
if (line[0] == '#')
continue;
if (!strncmp(line, "SYSTEMID", 8)) {
_copy_idline_str(line, _devices_file_systemid, sizeof(_devices_file_systemid));
log_debug("read devices file systemid %s", _devices_file_systemid);
if ((!cmd->system_id && _devices_file_systemid[0]) ||
(cmd->system_id && strcmp(cmd->system_id, _devices_file_systemid))) {
log_warn("WARNING: devices file has unmatching system id %s vs local %s.",
_devices_file_systemid[0] ? _devices_file_systemid : "none", cmd->system_id ?: "none");
}
continue;
}
if (!strncmp(line, "VERSION", 7)) {
_copy_idline_str(line, _devices_file_version, sizeof(_devices_file_version));
log_debug("read devices file version %s", _devices_file_version);
continue;
}
idtype = strstr(line, "IDTYPE");
idname = strstr(line, "IDNAME");
devname = strstr(line, "DEVNAME");
pvid = strstr(line, "PVID");
part = strstr(line, "PART");
line_error = 0;
/* These two are the minimum required. */
if (!idtype || !idname)
continue;
if (!(du = zalloc(sizeof(struct dev_use)))) {
log_warn("WARNING: failed to process devices file entry.");
continue;
}
_copy_idline_str(idtype, buf, PATH_MAX);
if (buf[0])
du->idtype = idtype_from_str(buf);
_copy_idline_str(idname, buf, PATH_MAX);
if (buf[0] && (buf[0] != '.')) {
if (!(du->idname = strdup(buf)))
line_error = 1;
}
if (devname) {
_copy_idline_str(devname, buf, PATH_MAX);
if (buf[0] && (buf[0] != '.')) {
if (!(du->devname = strdup(buf)))
line_error = 1;
}
}
if (pvid) {
_copy_idline_str(pvid, buf, PATH_MAX);
if (buf[0] && (buf[0] != '.')) {
if (!(du->pvid = strdup(buf)))
line_error = 1;
}
}
if (part) {
_copy_idline_str(part, buf, PATH_MAX);
if (buf[0] && (buf[0] != '.'))
du->part = atoi(buf);
}
if (line_error) {
log_warn("WARNING: failed to process devices file entry.");
free_du(du);
continue;
}
dm_list_add(&cmd->use_devices, &du->list);
}
if (fclose(fp))
stack;
return ret;
}
int device_ids_write(struct cmd_context *cmd)
{
char dirpath[PATH_MAX];
char tmppath[PATH_MAX];
char version_buf[VERSION_LINE_MAX] = {0};
FILE *fp;
int dir_fd;
time_t t;
struct dev_use *du;
const char *devname;
const char *pvid;
uint32_t df_major = 0, df_minor = 0, df_counter = 0;
int file_exists;
int ret = 1;
if (!cmd->enable_devices_file && !cmd->pending_devices_file)
return 1;
/*
* pending_devices_file: setup_devices found no system devices file
* exists and has not enabled the devices file, but may want to
* create a new devices file here and enable it.
*
* If this is pvcreate/vgcreate with the system devices file,
* and the devices file doesn't exist, then we may not want to
* create one for the new PVs created. This is because doing so
* would cause existing PVs on the system to be left out and not
* be visible. So, if the pvcreate/vgcreate have seen existing PVs
* during the label scan, then skip creating/writing a new system
* devices file. But, if they have not seen any other PVs, then
* create a new system devices file here with the newly created PVs.
* The idea is that pvcreate/vgcreate of the first PVs is probably
* system installation, and we'd like to have a devices file created
* automatically during installation. (The installer could also touch
* the devices file to create it, and that would cause
* pvcreate/vgcreate to always populate it.)
*/
file_exists = devices_file_exists(cmd);
log_debug("device_ids_write create %d edit %d pending %d exists %d version %s devicesfile %s",
cmd->create_edit_devices_file, cmd->edit_devices_file, cmd->pending_devices_file, file_exists,
_devices_file_version[0] ? _devices_file_version : ".", cmd->devicesfile ?: ".");
if (cmd->pending_devices_file && cmd->create_edit_devices_file && !cmd->devicesfile && !file_exists &&
(!strncmp(cmd->name, "pvcreate", 8) || !strncmp(cmd->name, "vgcreate", 8))) {
/* If any PVs were seen during scan then don't create a new devices file. */
if (lvmcache_vg_info_count()) {
log_warn("Not creating system devices file due to existing VGs.");
free_dus(&cmd->use_devices);
return 1;
}
log_warn("Creating devices file %s", cmd->devices_file_path);
cmd->enable_devices_file = 1;
}
if (test_mode())
return 1;
if (_devices_file_version[0]) {
if (sscanf(_devices_file_version, "%u.%u.%u", &df_major, &df_minor, &df_counter) != 3) {
/* don't update a file we can't parse */
log_warn("WARNING: not updating devices file with unparsed version.");
return 0;
}
if (df_major > DEVICES_FILE_MAJOR) {
/* don't update a file with a newer major version */
log_warn("WARNING: not updating devices file with larger major version.");
return 0;
}
}
if (dm_snprintf(dirpath, sizeof(dirpath), "%s/devices", cmd->system_dir) < 0) {
ret = 0;
goto out;
}
if (dm_snprintf(tmppath, sizeof(tmppath), "%s_new", cmd->devices_file_path) < 0) {
ret = 0;
goto out;
}
(void) unlink(tmppath); /* in case a previous file was left */
if (!(fp = fopen(tmppath, "w+"))) {
log_warn("Cannot open tmp devices_file to write.");
ret = 0;
goto out;
}
if ((dir_fd = open(dirpath, O_RDONLY)) < 0) {
if (fclose(fp))
log_sys_debug("fclose", tmppath);
ret = 0;
goto out;
}
t = time(NULL);
fprintf(fp, "# LVM uses devices listed in this file.\n");
fprintf(fp, "# Created by LVM command %s pid %d at %s", cmd->name, getpid(), ctime(&t));
/*
* It's useful to ensure that this devices file is associated to a
* single system because this file can be used to control access to
* shared devices. If this file is copied/cloned to another system,
* that new system should not automatically gain access to the devices
* that the original system is using.
*/
if (cmd->system_id)
fprintf(fp, "SYSTEMID=%s\n", cmd->system_id);
if (dm_snprintf(version_buf, VERSION_LINE_MAX, "VERSION=%u.%u.%u", DEVICES_FILE_MAJOR, DEVICES_FILE_MINOR, df_counter+1) < 0)
stack;
else
fprintf(fp, "%s\n", version_buf);
/* as if we had read this version in case we want to write again */
memset(_devices_file_version, 0, sizeof(_devices_file_version));
_copy_idline_str(version_buf, _devices_file_version, sizeof(_devices_file_version));
dm_list_iterate_items(du, &cmd->use_devices) {
devname = du->dev ? dev_name(du->dev) : du->devname;
if (!devname || devname[0] != '/')
devname = ".";
if (!du->pvid || !du->pvid[0] || (du->pvid[0] == '.'))
pvid = ".";
else
pvid = du->pvid;
if (du->part) {
fprintf(fp, "IDTYPE=%s IDNAME=%s DEVNAME=%s PVID=%s PART=%d\n",
idtype_to_str(du->idtype) ?: ".",
du->idname ?: ".", devname, pvid, du->part);
} else {
fprintf(fp, "IDTYPE=%s IDNAME=%s DEVNAME=%s PVID=%s\n",
idtype_to_str(du->idtype) ?: ".",
du->idname ?: ".", devname, pvid);
}
}
if (fflush(fp))
stack;
if (fclose(fp))
stack;
if (rename(tmppath, cmd->devices_file_path) < 0) {
log_error("Failed to replace devices file errno %d", errno);
ret = 0;
}
if (fsync(dir_fd) < 0)
stack;
if (close(dir_fd) < 0)
stack;
log_debug("Wrote devices file %s", version_buf);
out:
return ret;
}
static void _device_ids_update_try(struct cmd_context *cmd)
{
int held = 0;
if (cmd->expect_missing_vg_device) {
log_print("Devices file update skipped.");
return;
}
/*
* Use a non-blocking lock since it's not essential to
* make this update, the next cmd will make these changes
* if we skip it this update.
* If this command already holds an ex lock on the
* devices file, lock_devices_file ex succeeds and
* held is set.
* If we get the lock, only update the devices file if
* it's not been changed since we read it.
*/
if (!lock_devices_file_try(cmd, LOCK_EX, &held)) {
log_debug("Skip devices file update (busy).");
} else {
if (device_ids_version_unchanged(cmd)) {
if (!device_ids_write(cmd))
stack;
} else
log_debug("Skip devices file update (changed).");
}
if (!held)
unlock_devices_file(cmd);
}
int device_ids_version_unchanged(struct cmd_context *cmd)
{
char line[PATH_MAX];
char version_buf[VERSION_LINE_MAX];
FILE *fp;
if (!(fp = fopen(cmd->devices_file_path, "r"))) {
log_warn("WARNING: cannot open devices file to read.");
return 0;
}
while (fgets(line, sizeof(line), fp)) {
if (line[0] == '#')
continue;
if (!strncmp(line, "VERSION", 7)) {
if (fclose(fp))
stack;
_copy_idline_str(line, version_buf, sizeof(version_buf));
log_debug("check devices file version %s prev %s", version_buf, _devices_file_version);
if (!strcmp(version_buf, _devices_file_version))
return 1;
return 0;
}
}
if (fclose(fp))
stack;
return 0;
}
int device_ids_use_devname(struct cmd_context *cmd)
{
struct dev_use *du;
dm_list_iterate_items(du, &cmd->use_devices) {
if (du->idtype == DEV_ID_TYPE_DEVNAME)
return 1;
}
return 0;
}
static int _device_ids_use_lvmlv(struct cmd_context *cmd)
{
struct dev_use *du;
dm_list_iterate_items(du, &cmd->use_devices) {
if (du->idtype == DEV_ID_TYPE_LVMLV_UUID)
return 1;
}
return 0;
}
struct dev_use *get_du_for_devno(struct cmd_context *cmd, dev_t devno)
{
struct dev_use *du;
dm_list_iterate_items(du, &cmd->use_devices) {
if (du->dev && du->dev->dev == devno)
return du;
}
return NULL;
}
struct dev_use *get_du_for_dev(struct cmd_context *cmd, struct device *dev)
{
struct dev_use *du;
dm_list_iterate_items(du, &cmd->use_devices) {
if (du->dev == dev)
return du;
}
return NULL;
}
struct dev_use *get_du_for_pvid(struct cmd_context *cmd, const char *pvid)
{
struct dev_use *du;
dm_list_iterate_items(du, &cmd->use_devices) {
if (!du->pvid)
continue;
if (!memcmp(du->pvid, pvid, ID_LEN))
return du;
}
return NULL;
}
struct dev_use *get_du_for_devname(struct cmd_context *cmd, const char *devname)
{
struct dev_use *du;
dm_list_iterate_items(du, &cmd->use_devices) {
if (!du->devname)
continue;
if (!strcmp(du->devname, devname))
return du;
}
return NULL;
}
struct dev_use *get_du_for_device_id(struct cmd_context *cmd, uint16_t idtype, const char *idname)
{
struct dev_use *du;
dm_list_iterate_items(du, &cmd->use_devices) {
if (du->idname && (du->idtype == idtype) && !strcmp(du->idname, idname))
return du;
}
return NULL;
}
/*
* Add or update entry for this dev.
* . add an entry to dev->ids and point dev->id to it
* . add or update entry in cmd->use_devices
*/
int device_id_add(struct cmd_context *cmd, struct device *dev, const char *pvid_arg,
const char *idtype_arg, const char *id_arg)
{
char pvid[ID_LEN+1] = { 0 };
uint16_t idtype = 0;
const char *idname = NULL;
const char *check_idname = NULL;
const char *update_matching_kind = NULL;
const char *update_matching_name = NULL;
struct dev_use *du, *update_du = NULL, *du_dev, *du_pvid, *du_devname, *du_devid;
struct dev_id *id;
int found_id = 0;
int part = 0;
if (!dev_get_partition_number(dev, &part))
return_0;
/* Ensure valid dev_name(dev) below. */
if (dm_list_empty(&dev->aliases))
return_0;
/*
* When enable_devices_file=0 and pending_devices_file=1 we let
* pvcreate/vgcreate add new du's to cmd->use_devices. These du's may
* be written to a new system devices file in device_ids_write, or they
* may not, or devices_file_write may decide not to write a new system
* devices file and devices file may remain disabled.
*/
if (!cmd->enable_devices_file && !cmd->pending_devices_file)
return 1;
/*
* The pvid_arg may be passed from a 'struct id' (pv->id) which
* may not have a terminating \0.
* Make a terminated copy to use as a string.
*/
memcpy(&pvid, pvid_arg, ID_LEN);
/*
* Choose the device_id type for the device being added.
*
* 0. use an idtype specified by the user
* 1. use an idtype specific to a special/virtual device type
* e.g. loop, mpath, crypt, lvmlv, md, etc.
* 2. use an idtype specified by user option.
* 3. use sys_wwid, if it exists.
* 4. use sys_serial, if it exists.
* 5. use devname as the last resort.
*/
if (idtype_arg) {
if (!(idtype = idtype_from_str(idtype_arg)))
log_warn("WARNING: ignoring unknown device_id type %s.", idtype_arg);
else {
if (id_arg) {
if ((idname = strdup(id_arg)))
goto id_done;
log_warn("WARNING: ignoring device_id name %s.", id_arg);
}
if ((idname = device_id_system_read(cmd, dev, idtype)))
goto id_done;
log_warn("WARNING: ignoring deviceidtype %s which is not available for device.", idtype_arg);
idtype = 0;
}
}
if (MAJOR(dev->dev) == cmd->dev_types->device_mapper_major) {
if (dev_has_mpath_uuid(cmd, dev, &idname)) {
idtype = DEV_ID_TYPE_MPATH_UUID;
goto id_done;
}
if (_dev_has_crypt_uuid(cmd, dev, &idname)) {
idtype = DEV_ID_TYPE_CRYPT_UUID;
goto id_done;
}
if (_dev_has_lvmlv_uuid(cmd, dev, &idname)) {
idtype = DEV_ID_TYPE_LVMLV_UUID;
goto id_done;
}
}
/* TODO: kpartx partitions on loop devs. */
if (MAJOR(dev->dev) == cmd->dev_types->loop_major) {
idtype = DEV_ID_TYPE_LOOP_FILE;
goto id_name;
}
if (MAJOR(dev->dev) == cmd->dev_types->md_major) {
idtype = DEV_ID_TYPE_MD_UUID;
goto id_name;
}
if (MAJOR(dev->dev) == cmd->dev_types->drbd_major) {
/* TODO */
log_warn("Missing support for DRBD idtype");
}
/*
* No device-specific, existing, or user-specified idtypes,
* so use first available of sys_wwid / sys_serial / devname.
*/
idtype = DEV_ID_TYPE_SYS_WWID;
id_name:
if (!(idname = device_id_system_read(cmd, dev, idtype))) {
if (idtype == DEV_ID_TYPE_SYS_WWID) {
idtype = DEV_ID_TYPE_SYS_SERIAL;
goto id_name;
}
idtype = DEV_ID_TYPE_DEVNAME;
goto id_name;
}
id_done:
/*
* Create a dev_id struct for the new idtype on dev->ids.
*/
dm_list_iterate_items(id, &dev->ids) {
if (id->idtype == idtype) {
found_id = 1;
break;
}
}
if (found_id && idname && strcmp(id->idname, idname)) {
dm_list_del(&id->list);
free_did(id);
found_id = 0;
}
if (!found_id) {
if (!(id = zalloc(sizeof(struct dev_id)))) {
free((char *)idname);
return_0;
}
id->idtype = idtype;
id->idname = (char *)idname;
id->dev = dev;
dm_list_add(&dev->ids, &id->list);
} else
free((char*)idname);
dev->id = id;
dev->flags |= DEV_MATCHED_USE_ID;
idname = NULL;
idtype = 0;
/*
* "dev" is the device we are adding.
* "id" is the device_id it's using, set in dev->id.
*
* Update the cmd->use_devices list for the new device. The
* use_devices list will be used to update the devices file.
*
* The dev being added can potentially overlap existing entries
* in various ways. If one of the existing entries is truely for
* this device being added, then we want to update that entry.
* If some other existing entries are not for the same device, but
* have some overlapping values, then we want to try to update
* those other entries to fix any incorrect info.
*/
/* Is there already an entry matched to this device? */
du_dev = get_du_for_dev(cmd, dev);
/* Is there already an entry matched to this device's pvid? */
du_pvid = get_du_for_pvid(cmd, pvid);
/* Is there already an entry using this device's name? */
du_devname = get_du_for_devname(cmd, dev_name(dev));
/* Is there already an entry using the device_id for this device? */
du_devid = get_du_for_device_id(cmd, id->idtype, id->idname);
if (du_dev)
log_debug("device_id_add %s pvid %s matches entry %p dev %s",
dev_name(dev), pvid, du_dev, dev_name(du_dev->dev));
if (du_pvid)
log_debug("device_id_add %s pvid %s matches entry %p dev %s with same pvid %s",
dev_name(dev), pvid, du_pvid, du_pvid->dev ? dev_name(du_pvid->dev) : ".",
du_pvid->pvid);
if (du_devid)
log_debug("device_id_add %s pvid %s matches entry %p dev %s with same device_id %d %s",
dev_name(dev), pvid, du_devid, du_devid->dev ? dev_name(du_devid->dev) : ".",
du_devid->idtype, du_devid->idname);
if (du_devname)
log_debug("device_id_add %s pvid %s matches entry %p dev %s with same devname %s",
dev_name(dev), pvid, du_devname, du_devname->dev ? dev_name(du_devname->dev) : ".",
du_devname->devname);
if (du_pvid && (du_pvid->dev != dev))
log_warn("WARNING: adding device %s with PVID %s which is already used for %s device_id %s.",
dev_name(dev), pvid, du_pvid->dev ? dev_name(du_pvid->dev) : "missing device",
du_pvid->idname ?: "none");
if (du_devid && (du_devid->dev != dev)) {
if (!du_devid->dev) {
log_warn("WARNING: adding device %s with idname %s which is already used for missing device.",
dev_name(dev), id->idname);
} else {
int ret1, ret2;
dev_t devt1, devt2;
/* Check if both entries are partitions of the same device. */
ret1 = dev_get_primary_dev(cmd->dev_types, dev, &devt1);
ret2 = dev_get_primary_dev(cmd->dev_types, du_devid->dev, &devt2);
if ((ret1 == 2) && (ret2 == 2) && (devt1 == devt2)) {
log_debug("Using separate entries for partitions of same device %s part %d %s part %d.",
dev_name(dev), part, dev_name(du_devid->dev), du_devid->part);
} else {
log_warn("WARNING: adding device %s with idname %s which is already used for %s.",
dev_name(dev), id->idname, dev_name(du_devid->dev));
}
}
}
/*
* If one of the existing entries (du_dev, du_pvid, du_devid, du_devname)
* is truely for the same device that is being added, then set update_du to
* that existing entry to be updated.
*/
if (du_dev) {
update_du = du_dev;
dm_list_del(&update_du->list);
update_matching_kind = "device";
update_matching_name = dev_name(dev);
} else if (du_pvid) {
/*
* If the device_id of the existing entry for PVID is the same
* as the device_id of the device being added, then update the
* existing entry. If the device_ids differ, then the devices
* have duplicate PVIDs, and the new device gets a new entry
* (if we allow it to be added.)
*/
if (du_pvid->idtype == id->idtype)
check_idname = strdup(id->idname);
else
check_idname = device_id_system_read(cmd, dev, du_pvid->idtype);
if (!du_pvid->idname || (check_idname && !strcmp(check_idname, du_pvid->idname))) {
update_du = du_pvid;
dm_list_del(&update_du->list);
update_matching_kind = "PVID";
update_matching_name = pvid;
} else {
if (!cmd->current_settings.yes &&
yes_no_prompt("Add device with duplicate PV to devices file?") == 'n') {
log_print("Device not added.");
free((void *)check_idname);
return 1;
}
}
} else if (du_devid) {
/*
* Do we create a new du or update the existing du?
* If it's the same device, update the existing du,
* but if it's two devices with the same device_id, then
* create a new du.
*
* We know that 'dev' has device_id 'id'.
* Check if du_devid->dev is different from 'dev'
* and that du_devid->idname matches id.
* If so, then there are two different devices with
* the same device_id (create a new du for dev.)
* If not, then update the existing du_devid.
*/
if (du_devid->dev == dev) {
/* update the existing entry with matching devid */
update_du = du_devid;
dm_list_del(&update_du->list);
update_matching_kind = "device_id";
update_matching_name = id->idname;
}
}
free((void *)check_idname);
if (!update_du) {
log_debug("Adding new entry to devices file for %s PVID %s %s %s.",
dev_name(dev), pvid, idtype_to_str(id->idtype), id->idname);
if (!(du = zalloc(sizeof(struct dev_use))))
return_0;
} else {
du = update_du;
log_debug("Updating existing entry in devices file for %s that matches %s %s.",
dev_name(dev), update_matching_kind, update_matching_name);
}
free(du->idname);
free(du->devname);
free(du->pvid);
du->idtype = id->idtype;
du->idname = strdup(id->idname);
du->devname = strdup(dev_name(dev));
du->dev = dev;
du->pvid = strdup(pvid);
dev_get_partition_number(dev, &du->part);
if (!du->idname || !du->devname || !du->pvid) {
free_du(du);
return_0;
}
dm_list_add(&cmd->use_devices, &du->list);
return 1;
}
/*
* Update entry for this dev.
* Set PVID=.
* update entry in cmd->use_devices
*/
void device_id_pvremove(struct cmd_context *cmd, struct device *dev)
{
struct dev_use *du;
if (!cmd->enable_devices_file)
return;
if (!(du = get_du_for_dev(cmd, dev))) {
log_warn("WARNING: devices to use does not include %s", dev_name(dev));
return;
}
if (du->pvid) {
free(du->pvid);
du->pvid = NULL;
}
}
void device_id_update_vg_uuid(struct cmd_context *cmd, struct volume_group *vg, struct id *old_vg_id)
{
struct dev_use *du;
struct lv_list *lvl;
char old_vgid[ID_LEN+1] = { 0 };
char new_vgid[ID_LEN+1] = { 0 };
char old_idname[PATH_MAX];
int update = 0;
if (!cmd->enable_devices_file)
return;
/* Without this setting there is no stacking LVs on PVs. */
if (!cmd->scan_lvs)
return;
/* Check if any devices file entries are stacked on LVs. */
if (!_device_ids_use_lvmlv(cmd))
return;
memcpy(old_vgid, old_vg_id, ID_LEN);
memcpy(new_vgid, &vg->id, ID_LEN);
/*
* for each LV in VG, if there is a du for that LV (meaning a PV exists
* on the LV), then update the du idname, replacing the old vgid with
* the new vgid.
*/
dm_list_iterate_items(lvl, &vg->lvs) {
memset(old_idname, 0, sizeof(old_idname));
memcpy(old_idname, "LVM-", 4);
memcpy(old_idname+4, old_vgid, ID_LEN);
memcpy(old_idname+4+ID_LEN, &lvl->lv->lvid.id[1], ID_LEN);
if ((du = get_du_for_device_id(cmd, DEV_ID_TYPE_LVMLV_UUID, old_idname))) {
log_debug("device_id update %s pvid %s vgid %s to %s",
du->devname ?: ".", du->pvid ?: ".", old_vgid, new_vgid);
memcpy(du->idname+4, new_vgid, ID_LEN);
update = 1;
if (du->dev && du->dev->id && (du->dev->id->idtype == DEV_ID_TYPE_LVMLV_UUID))
memcpy(du->dev->id->idname+4, new_vgid, ID_LEN);
}
}
if (update &&
!device_ids_write(cmd))
stack;
unlock_devices_file(cmd);
}
static int _idtype_compatible_with_major_number(struct cmd_context *cmd, int idtype, int major)
{
/* devname can be used with any kind of device */
if (idtype == DEV_ID_TYPE_DEVNAME)
return 1;
if (idtype == DEV_ID_TYPE_MPATH_UUID ||
idtype == DEV_ID_TYPE_CRYPT_UUID ||
idtype == DEV_ID_TYPE_LVMLV_UUID)
return (major == cmd->dev_types->device_mapper_major);
if (idtype == DEV_ID_TYPE_MD_UUID)
return (major == cmd->dev_types->md_major);
if (idtype == DEV_ID_TYPE_LOOP_FILE)
return (major == cmd->dev_types->loop_major);
if (major == cmd->dev_types->device_mapper_major)
return (idtype == DEV_ID_TYPE_MPATH_UUID ||
idtype == DEV_ID_TYPE_CRYPT_UUID ||
idtype == DEV_ID_TYPE_LVMLV_UUID ||
idtype == DEV_ID_TYPE_DEVNAME);
if (major == cmd->dev_types->md_major)
return (idtype == DEV_ID_TYPE_MD_UUID ||
idtype == DEV_ID_TYPE_DEVNAME);
if (major == cmd->dev_types->loop_major)
return (idtype == DEV_ID_TYPE_LOOP_FILE ||
idtype == DEV_ID_TYPE_DEVNAME);
return 1;
}
static int _match_dm_devnames(struct cmd_context *cmd, struct device *dev,
struct dev_id *id, struct dev_use *du)
{
struct stat buf;
if (MAJOR(dev->dev) != cmd->dev_types->device_mapper_major)
return 0;
if (id->idname && du->idname && !strcmp(id->idname, du->idname))
return 1;
if (du->idname && !strcmp(du->idname, dev_name(dev))) {
log_debug("Match device_id %s %s to %s: ignoring idname %s",
idtype_to_str(du->idtype), du->idname, dev_name(dev), id->idname ?: ".");
return 1;
}
if (!du->idname)
return 0;
/* detect that a du entry is for a dm device */
if (!strncmp(du->idname, "/dev/dm-", 8) || !strncmp(du->idname, "/dev/mapper/", 12)) {
if (stat(du->idname, &buf))
return 0;
if ((MAJOR(buf.st_rdev) == cmd->dev_types->device_mapper_major) &&
(MINOR(buf.st_rdev) == MINOR(dev->dev))) {
log_debug("Match device_id %s %s to %s: using other dm name, ignoring %s",
idtype_to_str(du->idtype), du->idname, dev_name(dev), id->idname ?: ".");
return 1;
}
}
return 0;
}
/*
* check for dev->ids entry with du->idtype, if found compare it,
* if not, system_read of this type and add entry to dev->ids, compare it.
* When a match is found, set up links among du/id/dev.
*/
static int _match_du_to_dev(struct cmd_context *cmd, struct dev_use *du, struct device *dev)
{
struct dev_id *id;
const char *idname;
int part;
/*
* The idname will be removed from an entry with devname type when the
* devname is read and found to hold a different PVID than the PVID in
* the entry. At that point we only have the PVID and no known
* location for it.
*/
if (!du->idname || !du->idtype) {
/*
log_debug("Mismatch device_id %s %s %s to %s",
du->idtype ? idtype_to_str(du->idtype) : "idtype_missing",
du->idname ? du->idname : "idname_missing",
du->devname ? du->devname : "devname_missing",
dev_name(dev));
*/
return 0;
}
/*
* Some idtypes can only match devices with a specific major number,
* so we can skip trying to match certain du entries based simply on
* the major number of dev.
*/
if (!_idtype_compatible_with_major_number(cmd, du->idtype, (int)MAJOR(dev->dev))) {
/*
log_debug("Mismatch device_id %s %s to %s: wrong major",
idtype_to_str(du->idtype), du->idname ?: ".", dev_name(dev));
*/
return 0;
}
if (!dev_get_partition_number(dev, &part)) {
/*
log_debug("Mismatch device_id %s %s to %s: no partition",
idtype_to_str(du->idtype), du->idname ?: ".", dev_name(dev));
*/
return 0;
}
if (part != du->part) {
/*
log_debug("Mismatch device_id %s %s to %s: wrong partition %d vs %d",
idtype_to_str(du->idtype), du->idname ?: ".", dev_name(dev), du->part, part);
*/
return 0;
}
dm_list_iterate_items(id, &dev->ids) {
if (id->idtype == du->idtype) {
if ((id->idtype == DEV_ID_TYPE_DEVNAME) && _match_dm_devnames(cmd, dev, id, du)) {
/* dm devs can have differing names that we know still match */
du->dev = dev;
dev->id = id;
dev->flags |= DEV_MATCHED_USE_ID;
log_debug("Match device_id %s %s to %s: dm names",
idtype_to_str(du->idtype), du->idname, dev_name(dev));
return 1;
} else if (id->idname && !strcmp(id->idname, du->idname)) {
du->dev = dev;
dev->id = id;
dev->flags |= DEV_MATCHED_USE_ID;
log_debug("Match device_id %s %s to %s",
idtype_to_str(du->idtype), du->idname, dev_name(dev));
return 1;
} else {
/*
log_debug("Mismatch device_id %s %s to %s: idname %s",
idtype_to_str(du->idtype), du->idname ?: ".", dev_name(dev), id->idname ?: ":");
*/
return 0;
}
}
}
if (!(id = zalloc(sizeof(struct dev_id))))
return_0;
if (!(idname = device_id_system_read(cmd, dev, du->idtype))) {
/*
* Save a new id in dev->ids for this type to indicate no match
* to avoid repeated system_read, since this called many times.
* Setting idtype and NULL idname means no id of this type.
*/
id->idtype = du->idtype;
id->dev = dev;
dm_list_add(&dev->ids, &id->list);
/*
log_debug("Mismatch device_id %s %s to %s: no idtype",
idtype_to_str(du->idtype), du->idname ?: ".", dev_name(dev));
*/
return 0;
}
/*
* Save this id for the device (so it can be quickly checked again), even
* if it's not the idtype used to identify the dev in device_id_file.
*/
id->idtype = du->idtype;
id->idname = (char *)idname;
id->dev = dev;
dm_list_add(&dev->ids, &id->list);
if (!strcmp(idname, du->idname)) {
du->dev = dev;
dev->id = id;
dev->flags |= DEV_MATCHED_USE_ID;
log_debug("Match device_id %s %s to %s",
idtype_to_str(du->idtype), du->idname, dev_name(dev));
return 1;
}
/*
log_debug("Mismatch device_id %s %s to %s: idname %s",
idtype_to_str(du->idtype), du->idname ?: ".", dev_name(dev), idname);
*/
return 0;
}
int device_ids_match_dev(struct cmd_context *cmd, struct device *dev)
{
struct dev_use *du;
/* First check the du entry with matching devname since it's likely correct. */
if ((du = get_du_for_devname(cmd, dev_name(dev)))) {
if (_match_du_to_dev(cmd, du, dev))
return 1;
}
/* Check all du entries since the devname could have changed. */
dm_list_iterate_items(du, &cmd->use_devices) {
if (!_match_du_to_dev(cmd, du, dev))
continue;
return 1;
}
return 0;
}
/*
* For each entry on cmd->use_devices (entries in the devices file),
* find a struct device from dev-cache. They are paired based strictly
* on the device id.
*
* This must not open or read devices. This function cannot use filters.
* filters are applied after this, and the filters may open devs in the first
* nodata filtering. The second filtering, done after label_scan has read
* a device, is allowed to read a device to evaluate filters that need to see
* data from the dev.
*
* When a device id of a particular type is obtained for a dev, a id for that
* type is saved in dev->ids in case it needs to be checked again.
*
* When a device in dev-cache is matched to an entry in the devices file
* (a struct dev_use), then:
* . du->dev = dev;
* . dev->id = id;
* . dev->flags |= DEV_MATCHED_USE_ID;
*
* Later when filter-deviceid is run to exclude devices that are not
* included in the devices file, the filter checks if DEV_MATCHED_USE_ID
* is set which means that the dev matches a devices file entry and
* passes the filter.
*/
void device_ids_match_device_list(struct cmd_context *cmd)
{
struct dev_use *du;
dm_list_iterate_items(du, &cmd->use_devices) {
if (du->dev)
continue;
if (!(du->dev = dev_cache_get_existing(cmd, du->devname, NULL))) {
log_warn("Device not found for %s.", du->devname);
} else {
/* Should we set dev->id? Which idtype? Use --deviceidtype? */
du->dev->flags |= DEV_MATCHED_USE_ID;
}
}
}
void device_ids_match(struct cmd_context *cmd)
{
struct dev_iter *iter;
struct dev_use *du;
struct device *dev;
if (cmd->enable_devices_list) {
device_ids_match_device_list(cmd);
return;
}
if (!cmd->enable_devices_file)
return;
log_debug("compare devices file entries to devices");
/*
* We would set cmd->filter_deviceid_skip but we are disabling
* all filters (dev_cache_get NULL arg) so it's not necessary.
*/
dm_list_iterate_items(du, &cmd->use_devices) {
/* already matched */
if (du->dev) {
log_debug("devices idname %s previously matched %s",
du->idname, dev_name(du->dev));
continue;
}
/*
* du->devname from the devices file is the last known
* device name. It may be incorrect, but it's usually
* correct, so it's an efficient place to check for a
* match first.
*
* NULL filter is used because we are just setting up the
* the du/dev pairs in preparation for using the filters.
*/
if (du->devname &&
(dev = dev_cache_get_existing(cmd, du->devname, NULL))) {
/* On successful match, du, dev, and id are linked. */
if (_match_du_to_dev(cmd, du, dev))
continue;
else {
/*
* The device node may exist but the device is disconnected / zero size,
* and likely has no sysfs entry to check for wwid. Continue to look
* for the device id on other devs.
*/
log_debug("devices entry %s %s devname found but not matched", du->devname, du->pvid ?: ".");
}
}
/*
* Iterate through all devs and try to match du.
*
* If a match is made here it means the du->devname is wrong,
* so the device_id file should be updated with a new devname.
*
* NULL filter is used because we are just setting up the
* the du/dev pairs in preparation for using the filters.
*/
if (!(iter = dev_iter_create(NULL, 0)))
continue;
while ((dev = dev_iter_get(cmd, iter))) {
if (dev->flags & DEV_MATCHED_USE_ID)
continue;
if (_match_du_to_dev(cmd, du, dev))
break;
}
dev_iter_destroy(iter);
}
if (!cmd->print_device_id_not_found)
return;
/*
* Look for entries in devices file for which we found no device.
*/
dm_list_iterate_items(du, &cmd->use_devices) {
/* Found a device for this entry. */
if (du->dev && (du->dev->flags & DEV_MATCHED_USE_ID))
continue;
/* This shouldn't be possible. */
if (du->dev && !(du->dev->flags & DEV_MATCHED_USE_ID)) {
log_error("Device %s not matched to device_id", dev_name(du->dev));
continue;
}
/* A detached device would get here which isn't uncommon. */
if ((du->idtype == DEV_ID_TYPE_DEVNAME) && du->devname)
log_warn("Devices file PVID %s last seen on %s not found.",
du->pvid ?: "none",
du->devname ?: "none");
else if (du->idtype == DEV_ID_TYPE_DEVNAME)
log_warn("Devices file PVID %s not found.",
du->pvid ?: "none");
else if (du->devname)
log_warn("Devices file %s %s PVID %s last seen on %s not found.",
idtype_to_str(du->idtype),
du->idname ?: "none",
du->pvid ?: "none",
du->devname);
else
log_warn("Devices file %s %s PVID %s not found.",
idtype_to_str(du->idtype),
du->idname ?: "none",
du->pvid ?: "none");
}
}
/*
* This is called after devices are scanned to compare what was found on disks
* vs what's in the devices file. The devices file could be outdated and need
* correcting; the authoritative data is what's on disk. Now that we have read
* the device labels and know the PVID's from disk we can check the PVID's in
* use_devices entries from the devices file.
*/
void device_ids_validate(struct cmd_context *cmd, struct dm_list *scanned_devs,
int *device_ids_invalid, int noupdate)
{
struct dm_list wrong_devs;
struct device *dev;
struct device_list *devl;
struct dev_use *du;
char *tmpdup;
int checked = 0;
int update_file = 0;
dm_list_init(&wrong_devs);
if (!cmd->enable_devices_file)
return;
log_debug("validating devices file entries");
/*
* Validate entries with proper device id types.
* idname is the authority for pairing du and dev.
*/
dm_list_iterate_items(du, &cmd->use_devices) {
if (!du->dev)
continue;
/* For this idtype the idname match is unreliable. */
if (du->idtype == DEV_ID_TYPE_DEVNAME)
continue;
dev = du->dev;
/*
* scanned_devs are the devices that have been scanned,
* so they are the only devs we can verify PVID for.
*/
if (scanned_devs && !dev_in_device_list(dev, scanned_devs))
continue;
/*
* The matched device could not be read so we do not have
* the PVID from disk and cannot verify the devices file entry.
*/
if (dev->flags & DEV_SCAN_NOT_READ)
continue;
/*
* du and dev may have been matched, but the dev could still
* have been excluded by other filters during label scan.
* This shouldn't generally happen, but if it does the user
* probably wants to do something about it.
*/
if (!cmd->filter->passes_filter(cmd, cmd->filter, dev, "persistent")) {
log_warn("Devices file %s is excluded: %s.",
dev_name(dev), dev_filtered_reason(dev));
continue;
}
checked++;
/*
* If the du pvid from the devices file does not match the
* pvid read from disk, replace the du pvid with the pvid from
* disk and update the pvid in the devices file entry.
*/
if (dev->pvid[0]) {
if (!du->pvid || memcmp(dev->pvid, du->pvid, ID_LEN)) {
log_warn("Device %s has PVID %s (devices file %s)",
dev_name(dev), dev->pvid, du->pvid ?: "none");
if (!(tmpdup = strdup(dev->pvid)))
continue;
free(du->pvid);
du->pvid = tmpdup;
update_file = 1;
*device_ids_invalid = 1;
}
} else {
if (du->pvid && (du->pvid[0] != '.')) {
log_warn("Device %s has no PVID (devices file %s)",
dev_name(dev), du->pvid);
free(du->pvid);
du->pvid = NULL;
update_file = 1;
*device_ids_invalid = 1;
}
}
/*
* Avoid thrashing changes to the devices file during
* startup due to device names that are still being
* established. Commands that may run during startup
* should set this flag.
*/
if (cmd->ignore_device_name_mismatch)
continue;
if (!du->devname || strcmp(dev_name(du->dev), du->devname)) {
log_warn("Device %s has updated name (devices file %s)",
dev_name(du->dev), du->devname ?: "none");
if (!(tmpdup = strdup(dev_name(du->dev))))
continue;
free(du->devname);
du->devname = tmpdup;
update_file = 1;
*device_ids_invalid = 1;
}
}
/*
* Validate entries with unreliable devname id type.
* pvid match overrides devname id match.
*/
dm_list_iterate_items(du, &cmd->use_devices) {
if (!du->dev)
continue;
if (du->idtype != DEV_ID_TYPE_DEVNAME)
continue;
dev = du->dev;
/*
* scanned_devs are the devices that have been scanned,
* so they are the only devs we can verify PVID for.
*/
if (scanned_devs && !dev_in_device_list(dev, scanned_devs))
continue;
/*
* The matched device could not be read so we do not have
* the PVID from disk and cannot verify the devices file entry.
*/
if (dev->flags & DEV_SCAN_NOT_READ)
continue;
if (dm_list_empty(&dev->aliases))
continue;
if (!cmd->filter->passes_filter(cmd, cmd->filter, dev, "persistent")) {
log_warn("Devices file %s is excluded: %s.",
dev_name(dev), dev_filtered_reason(dev));
/* FIXME: what if this dev is wrongly matched and should be checked below? */
continue;
}
if (!du->pvid || du->pvid[0] == '.')
continue;
checked++;
/*
* A good match based on pvid.
*/
if (dev->pvid[0] && !memcmp(dev->pvid, du->pvid, ID_LEN)) {
const char *devname = dev_name(dev);
if (strcmp(devname, du->idname)) {
/* shouldn't happen since this was basis for match */
log_error("du for pvid %s unexpected idname %s mismatch dev %s",
du->pvid, du->idname, devname);
*device_ids_invalid = 1;
continue;
}
if (!du->devname || strcmp(devname, du->devname)) {
log_warn("Device %s has updated name (devices file %s)",
devname, du->devname ?: "none");
if (!(tmpdup = strdup(devname)))
continue;
free(du->devname);
du->devname = tmpdup;
update_file = 1;
*device_ids_invalid = 1;
}
continue;
}
/*
* An incorrect match, the pvid read from dev does not match
* du->pvid for the du dev was matched to.
* du->idname is wrong, du->devname is probably wrong.
* undo the incorrect match between du and dev
*/
if (dev->pvid[0])
log_warn("Devices file PVID %s not found on device %s (device PVID %s).",
du->pvid, dev_name(dev), dev->pvid[0] ? dev->pvid : "none");
else
log_warn("Devices file PVID %s not found on device %s.",
du->pvid, dev_name(dev));
if ((devl = dm_pool_zalloc(cmd->mem, sizeof(*devl)))) {
/* If this dev matches no du, drop it at the end. */
devl->dev = dev;
dm_list_add(&wrong_devs, &devl->list);
}
if (du->idname) {
free(du->idname);
du->idname = NULL;
}
/*
* Keep the old devname hint in place to preserve some clue about
* the previous location of the PV which may help the user understand
* what happened.
*/
/*
if (du->devname) {
free(du->devname);
du->devname = NULL;
}
*/
dev->flags &= ~DEV_MATCHED_USE_ID;
dev->id = NULL;
du->dev = NULL;
update_file = 1;
*device_ids_invalid = 1;
}
/*
* devs that were wrongly matched to a du and are not being
* used in another correct du should be dropped.
*/
dm_list_iterate_items(devl, &wrong_devs) {
if (!get_du_for_dev(cmd, devl->dev)) {
log_debug("Drop incorrectly matched %s", dev_name(devl->dev));
cmd->filter->wipe(cmd, cmd->filter, devl->dev, NULL);
lvmcache_del_dev(devl->dev);
}
}
/*
* Check for other problems for which we want to set *device_ids_invalid,
* even if we don't have a way to fix them right here. In particular,
* issues that may be fixed shortly by device_ids_find_renamed_devs.
*
* The device_ids_invalid flag is only used to tell the caller not
* to write hints, which could be based on invalid device info.
* (There may be a better way to deal with that then returning
* this flag.)
*/
dm_list_iterate_items(du, &cmd->use_devices) {
if (*device_ids_invalid)
break;
if (!du->idname || (du->idname[0] == '.'))
*device_ids_invalid = 1;
if ((du->idtype == DEV_ID_TYPE_DEVNAME) && !du->dev && du->pvid)
*device_ids_invalid = 1;
}
/*
* When a new devname/pvid mismatch is discovered, a new search for the
* pvid should be permitted (searched_devnames may exist to suppress
* searching for other pvids.)
*/
if (update_file)
unlink_searched_devnames(cmd);
/* FIXME: for wrong devname cases, wait to write new until device_ids_find_renamed_devs? */
/*
* try lock and device_ids_write(), the update is not required and will
* be done by a subsequent command if it's not done here.
*/
if (update_file && noupdate) {
log_debug("device ids validate checked %d update disabled.", checked);
} else if (update_file) {
log_debug("device ids validate checked %d trying to update devices file.", checked);
_device_ids_update_try(cmd);
} else {
log_debug("device ids validate checked %d found no update is needed.", checked);
}
}
/*
* Devices with IDNAME=devname that are mistakenly included by filter-deviceid
* due to a devname change are fully scanned and added to lvmcache.
* device_ids_validate() catches this by seeing that the pvid on the device
* doesn't match what's in the devices file, and then excludes the dev, and
* drops the lvmcache info for the dev. It would be nicer to catch the issue
* earlier, before the dev is fully scanned (and populated in lvmcache). This
* could be done by checking the devices file for the pvid right after the dev
* header is read and before scanning more metadata. label_scan could read the
* pvid from the pv_header and check it prior to calling _text_read().
* Currently it's _text_read() that first gets the pvid from the dev, and
* passes it to lvmcache_add() which sets it in dev->pvid.
*
* This function searches devs for missing PVIDs, and for those found
* updates the du structs (devices file entries) and writes an updated
* devices file.
*
* TODO: should we disable find_renamed_devs entirely when the command
* is using a non-system devices file?
*/
void device_ids_find_renamed_devs(struct cmd_context *cmd, struct dm_list *dev_list,
int *search_count, int noupdate)
{
struct device *dev;
struct dev_use *du;
struct dev_id *id;
struct dev_iter *iter;
struct device_list *devl; /* holds struct device */
struct device_id_list *dil, *dil2; /* holds struct device + pvid */
struct dm_list search_pvids; /* list of device_id_list */
struct dm_list search_devs ; /* list of device_list */
const char *devname;
int update_file = 0;
int other_idtype = 0;
int other_pvid = 0;
int no_pvid = 0;
int found = 0;
int not_found = 0;
int search_none;
int search_auto;
dm_list_init(&search_pvids);
dm_list_init(&search_devs);
if (!cmd->enable_devices_file)
return;
search_none = !strcmp(cmd->search_for_devnames, "none");
search_auto = !strcmp(cmd->search_for_devnames, "auto");
dm_list_iterate_items(du, &cmd->use_devices) {
if (!du->pvid)
continue;
if (du->idtype != DEV_ID_TYPE_DEVNAME)
continue;
/*
* if the old incorrect devname is now a device that's
* filtered and not scanned, e.g. an mpath component,
* then we want to look for the pvid on a new device.
*/
if (du->dev && !du->dev->filtered_flags)
continue;
if (!(dil = dm_pool_zalloc(cmd->mem, sizeof(*dil))))
continue;
if (!search_none) {
memcpy(dil->pvid, du->pvid, ID_LEN);
dm_list_add(&search_pvids, &dil->list);
}
log_debug("Search for PVID %s.", du->pvid);
if (search_count)
(*search_count)++;
}
if (dm_list_empty(&search_pvids))
return;
/*
* A previous command searched for devnames and found nothing, so it
* created the searched file to tell us not to bother. Without this, a
* device that's permanently detached (and identified by devname) would
* cause every command to search for it. If the detached device is
* later attached, it will generate a pvscan, and pvscan will unlink
* the searched file, so a subsequent lvm command will do the search
* again. In future perhaps we could add a policy to automatically
* remove a devices file entry that's not been found for some time.
*
* TODO: like the hint file, add a hash of all devnames to the searched
* file so it can be ignored and removed if the devs/hash change.
* If hints are enabled, the hints invalidation could also remove the
* searched file.
*/
if (_searched_devnames_exists(cmd)) {
log_debug("Search for PVIDs skipped for %s", _searched_file);
return;
}
/*
* Now we want to look at devs on the system that were previously
* rejected by filter-deviceid (based on a devname device id) to check
* if the missing PVID is on a device with a new name.
*/
log_debug("Search for PVIDs filtering.");
/*
* Initial list of devs to search, eliminating any that have already
* been matched, or don't pass filters that do not read dev. We do not
* want to modify the command's existing filter chain (the persistent
* filter), in the process of doing this search outside the deviceid
* filter.
*/
if (!(iter = dev_iter_create(NULL, 0)))
return;
while ((dev = dev_iter_get(cmd, iter))) {
if (dev->flags & DEV_MATCHED_USE_ID)
continue;
if (!cmd->filter->passes_filter(cmd, cmd->filter, dev, "sysfs"))
continue;
if (!cmd->filter->passes_filter(cmd, cmd->filter, dev, "type"))
continue;
if (!cmd->filter->passes_filter(cmd, cmd->filter, dev, "usable"))
continue;
if (!cmd->filter->passes_filter(cmd, cmd->filter, dev, "mpath"))
continue;
if (!(devl = dm_pool_zalloc(cmd->mem, sizeof(*devl))))
continue;
devl->dev = dev;
dm_list_add(&search_devs, &devl->list);
}
dev_iter_destroy(iter);
log_debug("Search for PVIDs reading labels on %d devs.", dm_list_size(&search_devs));
/*
* Read the dev to get the pvid, and run the filters that will use the
* data that has been read to get the pvid. Like above, we do not want
* to modify the command's existing filter chain or the persistent
* filter values.
*/
dm_list_iterate_items(devl, &search_devs) {
dev = devl->dev;
int has_pvid;
/*
* We only need to check devs that would use ID_TYPE_DEVNAME
* themselves as alternatives to the missing ID_TYPE_DEVNAME
* entry. i.e. a ID_TYPE_DEVNAME entry would not appear on a
* device that has a wwid and would use ID_TYPE_SYS_WWID. So,
* if a dev in the search_devs list has a proper/stable device
* id (e.g. wwid, serial, loop, mpath), then we don't need to
* read it to check for missing PVIDs.
*
* search_for_devnames="all" means we should search every
* device, so we skip this optimization.
*
* TODO: in auto mode should we look in other non-system
* devices files and skip any devs included in those?
*
* Note that a user can override a stable id type and use
* devname for a device's id, in which case this optimization
* can prevent a search from finding a renamed dev. So, if a
* user forces a devname id, then they should probably also
* set search_for_devnames=all.
*/
if (search_auto && _dev_has_stable_id(cmd, dev)) {
other_idtype++;
continue;
}
/*
* Reads 4K from the start of the disk.
* Returns 0 if the dev cannot be read.
* Looks for LVM header, and sets dev->pvid if the device is a PV.
* Sets has_pvid=1 if the dev has an lvm PVID.
* This loop may look at and skip many non-LVM devices.
*/
if (!label_read_pvid(dev, &has_pvid)) {
no_pvid++;
continue;
}
if (!has_pvid) {
no_pvid++;
continue;
}
/*
* These filters will use the block of data from bcache that
* was read label_read_pvid(), and may read other
* data blocks beyond that.
*/
if (!cmd->filter->passes_filter(cmd, cmd->filter, dev, "partitioned"))
goto next;
if (!cmd->filter->passes_filter(cmd, cmd->filter, dev, "signature"))
goto next;
if (!cmd->filter->passes_filter(cmd, cmd->filter, dev, "md"))
goto next;
if (!cmd->filter->passes_filter(cmd, cmd->filter, dev, "fwraid"))
goto next;
/*
* Check if the the PVID is one we are searching for.
* Loop below looks at search_pvid entries that have dil->dev set.
* This continues checking after all search_pvids entries have been
* matched in order to check if the PVID is on duplicate devs.
*/
dm_list_iterate_items_safe(dil, dil2, &search_pvids) {
if (!memcmp(dil->pvid, dev->pvid, ID_LEN)) {
if (dil->dev) {
log_warn("WARNING: found PVID %s on multiple devices %s %s.",
dil->pvid, dev_name(dil->dev), dev_name(dev));
log_warn("WARNING: duplicate PVIDs should be changed to be unique.");
log_warn("WARNING: use lvmdevices to select a device for PVID %s.", dil->pvid);
dm_list_del(&dil->list);
} else {
log_warn("Devices file PVID %s found on %s.", dil->pvid, dev_name(dev));
dil->dev = dev;
}
} else {
other_pvid++;
}
}
next:
label_scan_invalidate(dev);
}
log_debug("Search for PVIDs other_pvid %d no_pvid %d other_idtype %d.", other_pvid, no_pvid, other_idtype);
/*
* The use_devices entries (repesenting the devices file) are
* updated for the new devices on which the PVs reside. The new
* correct devs are set as dil->dev on search_pvids entries.
*
* The du/dev/id are set up and linked for the new devs.
*
* The command's full filter chain is updated for the new devs now that
* filter-deviceid will pass.
*/
dm_list_iterate_items(dil, &search_pvids) {
char *dup_devname1, *dup_devname2, *dup_devname3;
if (!dil->dev || dm_list_empty(&dil->dev->aliases)) {
not_found++;
continue;
}
dev = dil->dev;
devname = dev_name(dev);
found++;
if (!(du = get_du_for_pvid(cmd, dil->pvid))) {
/* shouldn't happen */
continue;
}
if (du->idtype != DEV_ID_TYPE_DEVNAME) {
/* shouldn't happen */
continue;
}
dup_devname1 = strdup(devname);
dup_devname2 = strdup(devname);
dup_devname3 = strdup(devname);
id = zalloc(sizeof(struct dev_id));
if (!dup_devname1 || !dup_devname2 || !dup_devname3 || !id) {
free(dup_devname1);
free(dup_devname2);
free(dup_devname3);
free(id);
stack;
continue;
}
if (!noupdate)
log_warn("Devices file PVID %s updating IDNAME to %s.", dev->pvid, devname);
free(du->idname);
free(du->devname);
free_dids(&dev->ids);
du->idname = dup_devname1;
du->devname = dup_devname2;
id->idtype = DEV_ID_TYPE_DEVNAME;
id->idname = dup_devname3;
id->dev = dev;
du->dev = dev;
dev->id = id;
dev->flags |= DEV_MATCHED_USE_ID;
dm_list_add(&dev->ids, &id->list);
dev_get_partition_number(dev, &du->part);
update_file = 1;
}
dm_list_iterate_items(dil, &search_pvids) {
if (!dil->dev)
continue;
dev = dil->dev;
cmd->filter->wipe(cmd, cmd->filter, dev, NULL);
if (!cmd->filter->passes_filter(cmd, cmd->filter, dev, NULL)) {
/* I don't think this would happen */
log_warn("WARNING: new device %s for PVID %s is excluded: %s.",
dev_name(dev), dil->pvid, dev_filtered_reason(dev));
if (du) /* Should not happen 'du' is NULL */
du->dev = NULL;
dev->flags &= ~DEV_MATCHED_USE_ID;
}
}
/*
* try lock and device_ids_write(), the update is not required and will
* be done by a subsequent command if it's not done here.
*
* This command could have already done an earlier device_ids_update_try
* (successfully or not) in device_ids_validate().
*/
if (update_file && noupdate) {
log_debug("Search for PVIDs update disabled");
} else if (update_file) {
log_debug("Search for PVIDs updating devices file");
_device_ids_update_try(cmd);
} else {
log_debug("Search for PVIDs found no updates");
}
/*
* The entries in search_pvids with a dev set are the new devs found
* for the PVIDs that we want to return to the caller in a device_list
* format.
*/
dm_list_iterate_items(dil, &search_pvids) {
if (!dil->dev)
continue;
dev = dil->dev;
if (!(devl = dm_pool_zalloc(cmd->mem, sizeof(*devl))))
continue;
devl->dev = dev;
dm_list_add(dev_list, &devl->list);
}
/*
* Prevent more devname searches by subsequent commands, in case the
* pvids not found were from devices that are permanently detached.
* If a new PV appears, pvscan will run and do unlink_searched_file.
*/
if (not_found && !found)
_touch_searched_devnames(cmd);
}
int devices_file_touch(struct cmd_context *cmd)
{
struct stat buf;
char dirpath[PATH_MAX];
int fd;
if (dm_snprintf(dirpath, sizeof(dirpath), "%s/devices", cmd->system_dir) < 0) {
log_error("Failed to copy devices dir path");
return 0;
}
if (stat(dirpath, &buf)) {
log_error("Cannot create devices file, missing devices directory %s.", dirpath);
return 0;
}
fd = open(cmd->devices_file_path, O_CREAT, S_IRUSR | S_IWUSR);
if (fd < 0) {
log_debug("Failed to create %s %d", cmd->devices_file_path, errno);
return 0;
}
if (close(fd))
stack;
return 1;
}
int devices_file_exists(struct cmd_context *cmd)
{
struct stat buf;
if (!cmd->devices_file_path[0])
return 0;
if (stat(cmd->devices_file_path, &buf))
return 0;
return 1;
}
/*
* If a command also uses the global lock, the global lock
* is acquired first, then the devices file is locked.
*
* There are three categories of commands in terms of
* reading/writing the devices file:
*
* 1. Commands that we know intend to modify the file,
* lvmdevices --add|--del, vgimportdevices,
* pvcreate/vgcreate/vgextend, pvchange --uuid,
* vgimportclone.
*
* 2. Most other commands that do not modify the file.
*
* 3. Commands from 2 that find something to correct in
* the devices file during device_ids_validate().
* These corrections are not essential and can be
* skipped, they will just be done by a subsequent
* command if they are not done.
*
* Locking for each case:
*
* 1. lock ex, read file, write file, unlock
*
* (In general, the command sets edit_devices_file or
* create_edit_devices_file, then setup_devices() is called,
* maybe directly, or by way of calling the traditional
* process_each->label_scan->setup_devices. setup_devices
* sees {create}_edit_devices_file which causes it to do
* lock_devices_file(EX) before creating/reading the file.)
*
* 2. lock sh, read file, unlock, (validate ok)
*
* 3. lock sh, read file, unlock, validate wants update,
* lock ex (nonblocking - skip update if fails),
* read file, check file is unchanged from prior read,
* write file, unlock
*/
static int _lock_devices_file(struct cmd_context *cmd, int mode, int nonblock, int *held)
{
const char *lock_dir;
const char *filename;
int fd;
int op = mode;
int ret;
if (!cmd->enable_devices_file || cmd->nolocking)
return 1;
_using_devices_file = 1;
if (_devices_file_locked == mode) {
/* can happen when a command holds an ex lock and does an update in device_ids_validate */
/* can happen when vgimportdevices calls this directly, followed later by setup_devices */
if (held)
*held = 1;
return 1;
}
if (_devices_file_locked) {
/* shouldn't happen */
log_warn("WARNING: devices file already locked %d", mode);
return 0;
}
if (!(lock_dir = find_config_tree_str(cmd, global_locking_dir_CFG, NULL)))
return_0;
if (!(filename = cmd->devicesfile ?: find_config_tree_str(cmd, devices_devicesfile_CFG, NULL)))
return_0;
if (dm_snprintf(_devices_lockfile, sizeof(_devices_lockfile), "%s/D_%s", lock_dir, filename) < 0)
return_0;
if (nonblock)
op |= LOCK_NB;
if (_devices_fd != -1) {
/* shouldn't happen */
log_warn("WARNING: devices file lock file already open %d", _devices_fd);
return 0;
}
fd = open(_devices_lockfile, O_CREAT|O_RDWR, S_IRUSR | S_IWUSR);
if (fd < 0) {
log_debug("lock_devices_file open errno %d", errno);
if (cmd->sysinit || cmd->ignorelockingfailure)
return 1;
return 0;
}
ret = flock(fd, op);
if (!ret) {
_devices_fd = fd;
_devices_file_locked = mode;
return 1;
}
log_debug("lock_devices_file flock errno %d", errno);
if (close(fd))
stack;
if (cmd->sysinit || cmd->ignorelockingfailure)
return 1;
return 0;
}
int lock_devices_file(struct cmd_context *cmd, int mode)
{
return _lock_devices_file(cmd, mode, 0, NULL);
}
int lock_devices_file_try(struct cmd_context *cmd, int mode, int *held)
{
return _lock_devices_file(cmd, mode, 1, held);
}
void unlock_devices_file(struct cmd_context *cmd)
{
int ret;
if (!cmd->enable_devices_file || cmd->nolocking || !_using_devices_file)
return;
if (!_devices_file_locked && cmd->sysinit)
return;
if (_devices_fd == -1) {
/* shouldn't happen */
log_warn("WARNING: devices file unlock no fd");
return;
}
if (!_devices_file_locked)
log_warn("WARNING: devices file unlock not locked");
ret = flock(_devices_fd, LOCK_UN);
if (ret)
log_warn("WARNING: devices file unlock errno %d", errno);
_devices_file_locked = 0;
if (close(_devices_fd))
stack;
_devices_fd = -1;
}
void devices_file_init(struct cmd_context *cmd)
{
dm_list_init(&cmd->use_devices);
}
void devices_file_exit(struct cmd_context *cmd)
{
if (!cmd->enable_devices_file)
return;
free_dus(&cmd->use_devices);
if (_devices_fd == -1)
return;
unlock_devices_file(cmd);
}
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