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Merge pull request #20603 from yuwata/udev-node-cleanups

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udev: cleanups for creating/removing device node symlinks
This commit is contained in:
Yu Watanabe 2021-09-03 05:33:06 +09:00 committed by GitHub
commit b2cdc2c05e
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5 changed files with 358 additions and 236 deletions
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1
src/libsystemd/sd-device/device-private.h
View File

@ -32,6 +32,7 @@ void device_set_db_persist(sd_device *device);
void device_set_devlink_priority(sd_device *device, int priority);
int device_ensure_usec_initialized(sd_device *device, sd_device *device_old);
int device_add_devlink(sd_device *device, const char *devlink);
bool device_has_devlink(sd_device *device, const char *devlink);
int device_add_property(sd_device *device, const char *property, const char *value);
int device_add_tag(sd_device *device, const char *tag, bool both);
void device_remove_tag(sd_device *device, const char *tag);

7
src/libsystemd/sd-device/sd-device.c
View File

@ -1205,6 +1205,13 @@ int device_add_devlink(sd_device *device, const char *devlink) {
return 0;
}
bool device_has_devlink(sd_device *device, const char *devlink) {
assert(device);
assert(devlink);
return set_contains(device->devlinks, devlink);
}
static int device_add_property_internal_from_string(sd_device *device, const char *str) {
_cleanup_free_ char *key = NULL;
char *value;

14
src/udev/udev-event.c
View File

@ -893,9 +893,6 @@ static int update_devnode(UdevEvent *event) {
if (r < 0)
return log_device_error_errno(dev, r, "Failed to get devnum: %m");
/* remove/update possible left-over symlinks from old database entry */
(void) udev_node_update_old_links(dev, event->dev_db_clone);
if (!uid_is_valid(event->uid)) {
r = device_get_devnode_uid(dev, &event->uid);
if (r < 0 && r != -ENOENT)
@ -919,7 +916,11 @@ static int update_devnode(UdevEvent *event) {
bool apply_mac = device_for_action(dev, SD_DEVICE_ADD);
return udev_node_add(dev, apply_mac, event->mode, event->uid, event->gid, event->seclabel_list);
r = udev_node_apply_permissions(dev, apply_mac, event->mode, event->uid, event->gid, event->seclabel_list);
if (r < 0)
return log_device_error_errno(dev, r, "Failed to apply devnode permissions: %m");
return udev_node_update(dev, event->dev_db_clone);
}
static int event_execute_rules_on_remove(
@ -1057,10 +1058,7 @@ int udev_event_execute_rules(
device_set_is_initialized(dev);
/* Yes, we run update_devnode() twice, because in the first invocation, that is before update of udev database,
* it could happen that two contenders are replacing each other's symlink. Hence we run it again to make sure
* symlinks point to devices that claim them with the highest priority. */
return update_devnode(event);
return 0;
}
void udev_event_execute_run(UdevEvent *event, usec_t timeout_usec, int timeout_signal) {

560
src/udev/udev-node.c
View File

@ -18,19 +18,25 @@
#include "fs-util.h"
#include "hexdecoct.h"
#include "mkdir.h"
#include "parse-util.h"
#include "path-util.h"
#include "random-util.h"
#include "selinux-util.h"
#include "smack-util.h"
#include "stat-util.h"
#include "stdio-util.h"
#include "string-util.h"
#include "strxcpyx.h"
#include "time-util.h"
#include "udev-node.h"
#include "user-util.h"
#define CREATE_LINK_MAX_RETRIES 128
#define LINK_UPDATE_MAX_RETRIES 128
#define TOUCH_FILE_MAX_RETRIES 128
#define CREATE_LINK_MAX_RETRIES 128
#define LINK_UPDATE_MAX_RETRIES 128
#define CREATE_STACK_LINK_MAX_RETRIES 128
#define UPDATE_TIMESTAMP_MAX_RETRIES 128
#define MAX_RANDOM_DELAY (250 * USEC_PER_MSEC)
#define MIN_RANDOM_DELAY ( 50 * USEC_PER_MSEC)
#define UDEV_NODE_HASH_KEY SD_ID128_MAKE(b9,6a,f1,ce,40,31,44,1a,9e,19,ec,8b,ae,f3,e3,2f)
static int create_symlink(const char *target, const char *slink) {
@ -69,6 +75,13 @@ static int node_symlink(sd_device *dev, const char *node, const char *slink) {
assert(node);
assert(slink);
if (lstat(slink, &stats) >= 0) {
if (!S_ISLNK(stats.st_mode))
return log_device_debug_errno(dev, SYNTHETIC_ERRNO(EEXIST),
"Conflicting inode '%s' found, link to '%s' will not be created.", slink, node);
} else if (errno != ENOENT)
return log_device_debug_errno(dev, errno, "Failed to lstat() '%s': %m", slink);
r = path_extract_directory(slink, &slink_dirname);
if (r < 0)
return log_device_debug_errno(dev, r, "Failed to get parent directory of '%s': %m", slink);
@ -78,41 +91,11 @@ static int node_symlink(sd_device *dev, const char *node, const char *slink) {
if (r < 0)
return log_device_debug_errno(dev, r, "Failed to get relative path from '%s' to '%s': %m", slink, node);
if (lstat(slink, &stats) >= 0) {
_cleanup_free_ char *buf = NULL;
if (!S_ISLNK(stats.st_mode))
return log_device_debug_errno(dev, SYNTHETIC_ERRNO(EEXIST),
"Conflicting inode '%s' found, link to '%s' will not be created.", slink, node);
if (readlink_malloc(slink, &buf) >= 0 &&
path_equal(target, buf)) {
/* preserve link with correct target, do not replace node of other device */
log_device_debug(dev, "Preserve already existing symlink '%s' to '%s'", slink, target);
(void) label_fix(slink, LABEL_IGNORE_ENOENT);
(void) utimensat(AT_FDCWD, slink, NULL, AT_SYMLINK_NOFOLLOW);
return 0;
}
} else if (errno == ENOENT) {
log_device_debug(dev, "Creating symlink '%s' to '%s'", slink, target);
r = create_symlink(target, slink);
if (r >= 0)
return 0;
log_device_debug_errno(dev, r, "Failed to create symlink '%s' to '%s', trying to replace '%s': %m", slink, target, slink);
} else
return log_device_debug_errno(dev, errno, "Failed to lstat() '%s': %m", slink);
log_device_debug(dev, "Atomically replace '%s'", slink);
r = device_get_device_id(dev, &id);
if (r < 0)
return log_device_debug_errno(dev, r, "Failed to get device id: %m");
slink_tmp = strjoina(slink, ".tmp-", id);
slink_tmp = strjoina(slink, ".tmp-", id);
(void) unlink(slink_tmp);
r = create_symlink(target, slink_tmp);
@ -125,8 +108,7 @@ static int node_symlink(sd_device *dev, const char *node, const char *slink) {
return r;
}
/* Tell caller that we replaced already existing symlink. */
return 1;
return 0;
}
static int link_find_prioritized(sd_device *dev, bool add, const char *stackdir, char **ret) {
@ -161,12 +143,13 @@ static int link_find_prioritized(sd_device *dev, bool add, const char *stackdir,
dir = opendir(stackdir);
if (!dir) {
if (errno == ENOENT) {
*ret = TAKE_PTR(target);
return !!*ret;
}
if (add) /* The stack directory must exist. */
return -errno;
if (errno != ENOENT)
return -errno;
return -errno;
*ret = NULL;
return 0;
}
r = device_get_device_id(dev, &id);
@ -174,39 +157,67 @@ static int link_find_prioritized(sd_device *dev, bool add, const char *stackdir,
return r;
FOREACH_DIRENT_ALL(dent, dir, break) {
_cleanup_(sd_device_unrefp) sd_device *dev_db = NULL;
const char *devnode;
int db_prio = 0;
_cleanup_free_ char *path = NULL, *buf = NULL;
int tmp_prio;
if (dent->d_name[0] == '\0')
break;
if (dent->d_name[0] == '.')
continue;
log_device_debug(dev, "Found '%s' claiming '%s'", dent->d_name, stackdir);
/* did we find ourself? */
/* skip ourself */
if (streq(dent->d_name, id))
continue;
if (sd_device_new_from_device_id(&dev_db, dent->d_name) < 0)
continue;
path = path_join(stackdir, dent->d_name);
if (!path)
return -ENOMEM;
if (sd_device_get_devname(dev_db, &devnode) < 0)
continue;
if (readlink_malloc(path, &buf) >= 0) {
char *devnode;
if (device_get_devlink_priority(dev_db, &db_prio) < 0)
continue;
/* New format. The devnode and priority can be obtained from symlink. */
if (target && db_prio <= priority)
continue;
devnode = strchr(buf, ':');
if (!devnode || devnode == buf)
continue;
log_device_debug(dev_db, "Device claims priority %i for '%s'", db_prio, stackdir);
*(devnode++) = '\0';
if (!path_startswith(devnode, "/dev"))
continue;
r = free_and_strdup(&target, devnode);
if (r < 0)
return r;
priority = db_prio;
if (safe_atoi(buf, &tmp_prio) < 0)
continue;
if (target && tmp_prio <= priority)
continue;
r = free_and_strdup(&target, devnode);
if (r < 0)
return r;
} else {
_cleanup_(sd_device_unrefp) sd_device *tmp_dev = NULL;
const char *devnode;
/* Old format. The devnode and priority must be obtained from uevent and
* udev database files. */
if (sd_device_new_from_device_id(&tmp_dev, dent->d_name) < 0)
continue;
if (device_get_devlink_priority(tmp_dev, &tmp_prio) < 0)
continue;
if (target && tmp_prio <= priority)
continue;
if (sd_device_get_devname(tmp_dev, &devnode) < 0)
continue;
r = free_and_strdup(&target, devnode);
if (r < 0)
return r;
}
priority = tmp_prio;
}
*ret = TAKE_PTR(target);
@ -255,12 +266,157 @@ toolong:
return size - 1;
}
static int update_timestamp(sd_device *dev, const char *path, struct stat *prev) {
assert(path);
assert(prev);
/* Even if a symlink in the stack directory is created/removed, the mtime of the directory may
* not be changed. Why? Let's consider the following situation. For simplicity, let's assume
* there exist three udev workers (A, B, and C) and all of them calls link_update() for the
* same devlink simultaneously.
*
* 1. B creates/removes a symlink in the stack directory.
* 2. A calls the first stat() in the loop of link_update().
* 3. A calls link_find_prioritized().
* 4. C creates/removes another symlink in the stack directory, so the result of the step 3 is outdated.
* 5. B and C finish link_update().
* 6. A creates/removes devlink according to the outdated result in the step 3.
* 7. A calls the second stat() in the loop of link_update().
*
* If these 7 steps are processed in this order within a short time period that kernel's timer
* does not increase, then even if the contents in the stack directory is changed, the results
* of two stat() called by A shows the same timestamp, and A cannot detect the change.
*
* By calling this function after creating/removing symlinks in the stack directory, the
* timestamp of the stack directory is always increased at least in the above step 5, so A can
* detect the update. */
if ((prev->st_mode & S_IFMT) == 0)
return 0; /* Does not exist, or previous stat() failed. */
for (unsigned i = 0; i < UPDATE_TIMESTAMP_MAX_RETRIES; i++) {
struct stat st;
if (stat(path, &st) < 0)
return -errno;
if (!stat_inode_unmodified(prev, &st))
return 0;
log_device_debug(dev,
"%s is modified, but its timestamp is not changed, "
"updating timestamp after 10ms.",
path);
(void) usleep(10 * USEC_PER_MSEC);
if (utimensat(AT_FDCWD, path, NULL, 0) < 0)
return -errno;
}
return -ELOOP;
}
static int update_stack_directory(sd_device *dev, const char *dirname, bool add) {
_cleanup_free_ char *filename = NULL, *data = NULL, *buf = NULL;
const char *devname, *id;
struct stat st = {};
int priority, r;
assert(dev);
assert(dirname);
r = device_get_device_id(dev, &id);
if (r < 0)
return log_device_debug_errno(dev, r, "Failed to get device id: %m");
filename = path_join(dirname, id);
if (!filename)
return log_oom_debug();
if (!add) {
bool unlink_failed = false;
if (stat(dirname, &st) < 0) {
if (errno == ENOENT)
return 0; /* The stack directory is already removed. That's OK. */
log_device_debug_errno(dev, errno, "Failed to stat %s, ignoring: %m", dirname);
}
if (unlink(filename) < 0) {
unlink_failed = true;
if (errno != ENOENT)
log_device_debug_errno(dev, errno, "Failed to remove %s, ignoring: %m", filename);
}
if (rmdir(dirname) >= 0 || errno == ENOENT)
return 0;
if (unlink_failed)
return 0; /* If we failed to remove the symlink, there is almost nothing we can do. */
/* The symlink was removed. Check if the timestamp of directory is changed. */
r = update_timestamp(dev, dirname, &st);
if (r < 0 && r != -ENOENT)
return log_device_debug_errno(dev, r, "Failed to update timestamp of %s: %m", dirname);
return 0;
}
r = sd_device_get_devname(dev, &devname);
if (r < 0)
return log_device_debug_errno(dev, r, "Failed to get device node: %m");
r = device_get_devlink_priority(dev, &priority);
if (r < 0)
return log_device_debug_errno(dev, r, "Failed to get priority of device node symlink: %m");
if (asprintf(&data, "%i:%s", priority, devname) < 0)
return log_oom_debug();
if (readlink_malloc(filename, &buf) >= 0 && streq(buf, data))
return 0;
if (unlink(filename) < 0 && errno != ENOENT)
log_device_debug_errno(dev, errno, "Failed to remove %s, ignoring: %m", filename);
for (unsigned j = 0; j < CREATE_STACK_LINK_MAX_RETRIES; j++) {
/* This may fail with -ENOENT when the parent directory is removed during
* creating the file by another udevd worker. */
r = mkdir_p(dirname, 0755);
if (r == -ENOENT)
continue;
if (r < 0)
return log_device_debug_errno(dev, r, "Failed to create directory %s: %m", dirname);
if (stat(dirname, &st) < 0) {
if (errno == ENOENT)
continue;
return log_device_debug_errno(dev, errno, "Failed to stat %s: %m", dirname);
}
if (symlink(data, filename) < 0) {
if (errno == ENOENT)
continue;
return log_device_debug_errno(dev, errno, "Failed to create symbolic link %s: %m", filename);
}
/* The symlink was created. Check if the timestamp of directory is changed. */
r = update_timestamp(dev, dirname, &st);
if (r < 0)
return log_device_debug_errno(dev, r, "Failed to update timestamp of %s: %m", dirname);
return 0;
}
return log_device_debug_errno(dev, SYNTHETIC_ERRNO(ELOOP), "Failed to create symbolic link %s: %m", filename);
}
/* manage "stack of names" with possibly specified device priorities */
static int link_update(sd_device *dev, const char *slink_in, bool add) {
_cleanup_free_ char *slink = NULL, *filename = NULL, *dirname = NULL;
const char *slink_name, *id;
_cleanup_free_ char *slink = NULL, *dirname = NULL;
const char *slink_name;
char name_enc[NAME_MAX+1];
int i, r, retries;
int r;
assert(dev);
assert(slink_in);
@ -278,51 +434,33 @@ static int link_update(sd_device *dev, const char *slink_in, bool add) {
return log_device_debug_errno(dev, SYNTHETIC_ERRNO(EINVAL),
"Invalid symbolic link of device node: %s", slink);
r = device_get_device_id(dev, &id);
if (r < 0)
return log_device_debug_errno(dev, r, "Failed to get device id: %m");
(void) udev_node_escape_path(slink_name, name_enc, sizeof(name_enc));
dirname = path_join("/run/udev/links/", name_enc);
dirname = path_join("/run/udev/links", name_enc);
if (!dirname)
return log_oom_debug();
filename = path_join(dirname, id);
if (!filename)
return log_oom_debug();
r = update_stack_directory(dev, dirname, add);
if (r < 0)
return r;
if (!add) {
if (unlink(filename) < 0 && errno != ENOENT)
log_device_debug_errno(dev, errno, "Failed to remove %s, ignoring: %m", filename);
(void) rmdir(dirname);
} else {
for (unsigned j = 0; j < TOUCH_FILE_MAX_RETRIES; j++) {
/* This may fail with -ENOENT when the parent directory is removed during
* creating the file by another udevd worker. */
r = touch_file(filename, /* parents= */ true, USEC_INFINITY, UID_INVALID, GID_INVALID, 0444);
if (r != -ENOENT)
break;
}
if (r < 0)
return log_device_debug_errno(dev, r, "Failed to create %s: %m", filename);
}
/* If the database entry is not written yet we will just do one iteration and possibly wrong symlink
* will be fixed in the second invocation. */
retries = sd_device_get_is_initialized(dev) > 0 ? LINK_UPDATE_MAX_RETRIES : 1;
for (i = 0; i < retries; i++) {
for (unsigned i = 0; i < LINK_UPDATE_MAX_RETRIES; i++) {
_cleanup_free_ char *target = NULL;
struct stat st1 = {}, st2 = {};
r = stat(dirname, &st1);
if (r < 0 && errno != ENOENT)
if (i > 0) {
usec_t delay = MIN_RANDOM_DELAY + random_u64_range(MAX_RANDOM_DELAY - MIN_RANDOM_DELAY);
log_device_debug(dev, "Directory %s was updated, retrying to update devlink %s after %s.",
dirname, slink, FORMAT_TIMESPAN(delay, USEC_PER_MSEC));
(void) usleep(delay);
}
if (stat(dirname, &st1) < 0 && errno != ENOENT)
return log_device_debug_errno(dev, errno, "Failed to stat %s: %m", dirname);
r = link_find_prioritized(dev, add, dirname, &target);
if (r < 0)
return log_device_debug_errno(dev, r, "Failed to determine highest priority for symlink '%s': %m", slink);
return log_device_debug_errno(dev, r, "Failed to determine device node with the highest priority for '%s': %m", slink);
if (r == 0) {
log_device_debug(dev, "No reference left for '%s', removing", slink);
@ -330,71 +468,135 @@ static int link_update(sd_device *dev, const char *slink_in, bool add) {
log_device_debug_errno(dev, errno, "Failed to remove '%s', ignoring: %m", slink);
(void) rmdir_parents(slink, "/dev");
break;
return 0;
}
r = node_symlink(dev, target, slink);
if (r < 0)
return r;
if (r == 1)
/* We have replaced already existing symlink, possibly there is some other device trying
* to claim the same symlink. Let's do one more iteration to give us a chance to fix
* the error if other device actually claims the symlink with higher priority. */
continue;
/* Skip the second stat() if the first failed, stat_inode_unmodified() would return false regardless. */
if ((st1.st_mode & S_IFMT) != 0) {
r = stat(dirname, &st2);
if (r < 0 && errno != ENOENT)
return log_device_debug_errno(dev, errno, "Failed to stat %s: %m", dirname);
if (stat(dirname, &st2) < 0 && errno != ENOENT)
return log_device_debug_errno(dev, errno, "Failed to stat %s: %m", dirname);
if (stat_inode_unmodified(&st1, &st2))
break;
}
if (((st1.st_mode & S_IFMT) == 0 && (st2.st_mode & S_IFMT) == 0) ||
stat_inode_unmodified(&st1, &st2))
return 0;
}
return i < LINK_UPDATE_MAX_RETRIES ? 0 : -ELOOP;
return -ELOOP;
}
int udev_node_update_old_links(sd_device *dev, sd_device *dev_old) {
const char *name;
static int device_get_devpath_by_devnum(sd_device *dev, char **ret) {
const char *subsystem;
dev_t devnum;
int r;
assert(dev);
assert(ret);
r = sd_device_get_subsystem(dev, &subsystem);
if (r < 0)
return r;
r = sd_device_get_devnum(dev, &devnum);
if (r < 0)
return r;
return device_path_make_major_minor(streq(subsystem, "block") ? S_IFBLK : S_IFCHR, devnum, ret);
}
int udev_node_update(sd_device *dev, sd_device *dev_old) {
_cleanup_free_ char *filename = NULL;
const char *devnode, *devlink;
int r;
assert(dev);
assert(dev_old);
r = sd_device_get_devname(dev, &devnode);
if (r < 0)
return log_device_debug_errno(dev, r, "Failed to get devnode: %m");
if (DEBUG_LOGGING) {
const char *id = NULL;
(void) device_get_device_id(dev, &id);
log_device_debug(dev, "Handling device node '%s', devnum=%s", devnode, strna(id));
}
/* update possible left-over symlinks */
FOREACH_DEVICE_DEVLINK(dev_old, name) {
const char *name_current;
bool found = false;
FOREACH_DEVICE_DEVLINK(dev_old, devlink) {
/* check if old link name still belongs to this device */
FOREACH_DEVICE_DEVLINK(dev, name_current)
if (streq(name, name_current)) {
found = true;
break;
}
if (found)
if (device_has_devlink(dev, devlink))
continue;
log_device_debug(dev,
"Updating old device symlink '%s', which is no longer belonging to this device.",
name);
"Removing/updating old device symlink '%s', which is no longer belonging to this device.",
devlink);
r = link_update(dev, name, false);
r = link_update(dev, devlink, /* add = */ false);
if (r < 0)
log_device_warning_errno(dev, r,
"Failed to update device symlink '%s', ignoring: %m",
name);
"Failed to remove/update device symlink '%s', ignoring: %m",
devlink);
}
/* create/update symlinks, add symlinks to name index */
FOREACH_DEVICE_DEVLINK(dev, devlink) {
r = link_update(dev, devlink, /* add = */ true);
if (r < 0)
log_device_warning_errno(dev, r,
"Failed to create/update device symlink '%s', ignoring: %m",
devlink);
}
r = device_get_devpath_by_devnum(dev, &filename);
if (r < 0)
return log_device_debug_errno(dev, r, "Failed to get device path: %m");
/* always add /dev/{block,char}/$major:$minor */
r = node_symlink(dev, devnode, filename);
if (r < 0)
return log_device_warning_errno(dev, r, "Failed to create device symlink '%s': %m", filename);
return 0;
}
static int node_permissions_apply(sd_device *dev, bool apply_mac,
mode_t mode, uid_t uid, gid_t gid,
OrderedHashmap *seclabel_list) {
int udev_node_remove(sd_device *dev) {
_cleanup_free_ char *filename = NULL;
const char *devlink;
int r;
assert(dev);
/* remove/update symlinks, remove symlinks from name index */
FOREACH_DEVICE_DEVLINK(dev, devlink) {
r = link_update(dev, devlink, /* add = */ false);
if (r < 0)
log_device_warning_errno(dev, r,
"Failed to remove/update device symlink '%s', ignoring: %m",
devlink);
}
r = device_get_devpath_by_devnum(dev, &filename);
if (r < 0)
return log_device_debug_errno(dev, r, "Failed to get device path: %m");
/* remove /dev/{block,char}/$major:$minor */
if (unlink(filename) < 0 && errno != ENOENT)
return log_device_debug_errno(dev, errno, "Failed to remove '%s': %m", filename);
return 0;
}
int udev_node_apply_permissions(
sd_device *dev,
bool apply_mac,
mode_t mode,
uid_t uid,
gid_t gid,
OrderedHashmap *seclabel_list) {
const char *devnode, *subsystem, *id = NULL;
bool apply_mode, apply_uid, apply_gid;
_cleanup_close_ int node_fd = -1;
@ -511,95 +713,5 @@ static int node_permissions_apply(sd_device *dev, bool apply_mac,
if (r < 0)
log_device_debug_errno(dev, r, "Failed to adjust timestamp of node %s: %m", devnode);
return r;
}
static int xsprintf_dev_num_path_from_sd_device(sd_device *dev, char **ret) {
const char *subsystem;
dev_t devnum;
int r;
assert(ret);
r = sd_device_get_subsystem(dev, &subsystem);
if (r < 0)
return r;
r = sd_device_get_devnum(dev, &devnum);
if (r < 0)
return r;
return device_path_make_major_minor(streq(subsystem, "block") ? S_IFBLK : S_IFCHR, devnum, ret);
}
int udev_node_add(sd_device *dev, bool apply,
mode_t mode, uid_t uid, gid_t gid,
OrderedHashmap *seclabel_list) {
const char *devnode, *devlink;
_cleanup_free_ char *filename = NULL;
int r;
assert(dev);
r = sd_device_get_devname(dev, &devnode);
if (r < 0)
return log_device_debug_errno(dev, r, "Failed to get devnode: %m");
if (DEBUG_LOGGING) {
const char *id = NULL;
(void) device_get_device_id(dev, &id);
log_device_debug(dev, "Handling device node '%s', devnum=%s", devnode, strna(id));
}
r = node_permissions_apply(dev, apply, mode, uid, gid, seclabel_list);
if (r < 0)
return r;
/* create/update symlinks, add symlinks to name index */
FOREACH_DEVICE_DEVLINK(dev, devlink) {
r = link_update(dev, devlink, true);
if (r < 0)
log_device_warning_errno(dev, r,
"Failed to update device symlink '%s', ignoring: %m",
devlink);
}
r = xsprintf_dev_num_path_from_sd_device(dev, &filename);
if (r < 0)
return log_device_debug_errno(dev, r, "Failed to get device path: %m");
/* always add /dev/{block,char}/$major:$minor */
r = node_symlink(dev, devnode, filename);
if (r < 0)
return log_device_warning_errno(dev, r, "Failed to create device symlink '%s': %m", filename);
return 0;
}
int udev_node_remove(sd_device *dev) {
_cleanup_free_ char *filename = NULL;
const char *devlink;
int r;
assert(dev);
/* remove/update symlinks, remove symlinks from name index */
FOREACH_DEVICE_DEVLINK(dev, devlink) {
r = link_update(dev, devlink, false);
if (r < 0)
log_device_warning_errno(dev, r,
"Failed to update device symlink '%s', ignoring: %m",
devlink);
}
r = xsprintf_dev_num_path_from_sd_device(dev, &filename);
if (r < 0)
return log_device_debug_errno(dev, r, "Failed to get device path: %m");
/* remove /dev/{block,char}/$major:$minor */
if (unlink(filename) < 0 && errno != ENOENT)
return log_device_debug_errno(dev, errno, "Failed to remove '%s': %m", filename);
return 0;
}

12
src/udev/udev-node.h
View File

@ -8,10 +8,14 @@
#include "hashmap.h"
int udev_node_add(sd_device *dev, bool apply,
mode_t mode, uid_t uid, gid_t gid,
OrderedHashmap *seclabel_list);
int udev_node_apply_permissions(
sd_device *dev,
bool apply_mac,
mode_t mode,
uid_t uid,
gid_t gid,
OrderedHashmap *seclabel_list);
int udev_node_remove(sd_device *dev);
int udev_node_update_old_links(sd_device *dev, sd_device *dev_old);
int udev_node_update(sd_device *dev, sd_device *dev_old);
size_t udev_node_escape_path(const char *src, char *dest, size_t size);