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don't remove symlinks if they are already there

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Consecutive "add" events will not remove and recreate the same symlinks
anymore. No longer valid links, like after changing a filesystem label,
will still be removed.
This commit is contained in:
Kay Sievers 2006-06-14 16:32:52 +02:00
parent afb66e3233
commit fa33d857e2
3 changed files with 61 additions and 14 deletions
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1
test/udev-test.pl
View File

@ -862,6 +862,7 @@ EOF
devpath => "/class/tty/tty0",
exp_name => "link",
exp_target => "link",
exp_add_error => "yes",
exp_rem_error => "yes",
option => "clean",
rules => <<EOF

35
udev_device.c
View File

@ -132,17 +132,38 @@ int udev_device_event(struct udev_rules *rules, struct udevice *udev)
/* read current database entry, we may want to cleanup symlinks */
udev_old = udev_device_init();
if (udev_old != NULL) {
if (udev_db_get_device(udev_old, udev->dev->devpath) == 0) {
info("device '%s' already known, remove possible symlinks", udev->dev->devpath);
udev_node_remove_symlinks(udev_old);
}
udev_device_cleanup(udev_old);
if (udev_db_get_device(udev_old, udev->dev->devpath) != 0) {
udev_device_cleanup(udev_old);
udev_old = NULL;
} else
info("device '%s' already in database, validate currently present symlinks",
udev->dev->devpath);
}
/* create node and symlinks, store record in database */
/* create node and symlinks */
retval = udev_node_add(udev, udev_old);
if (retval == 0)
if (retval == 0) {
/* store record in database */
udev_db_add_device(udev);
/* remove possibly left-over symlinks */
if (udev_old != NULL) {
struct name_entry *link_loop;
struct name_entry *link_old_loop;
struct name_entry *link_old_tmp_loop;
/* remove still valid symlinks from old list */
list_for_each_entry_safe(link_old_loop, link_old_tmp_loop, &udev_old->symlink_list, node)
list_for_each_entry(link_loop, &udev->symlink_list, node)
if (strcmp(link_old_loop->name, link_loop->name) == 0) {
dbg("symlink '%s' still valid, keep it", link_old_loop->name);
list_del(&link_old_loop->node);
free(link_old_loop);
}
udev_node_remove_symlinks(udev_old);
udev_device_cleanup(udev_old);
}
}
goto exit;
}

39
udev_node.c
View File

@ -90,6 +90,36 @@ exit:
return retval;
}
static int udev_node_symlink(struct udevice *udev, const char *linktarget, const char *filename)
{
char target[PATH_SIZE];
int len;
/* look if symlink already exists */
len = readlink(filename, target, sizeof(target));
if (len > 0) {
target[len] = '\0';
if (strcmp(linktarget, target) == 0) {
info("preserving symlink '%s' to '%s'", filename, linktarget);
selinux_setfilecon(filename, NULL, S_IFLNK);
goto exit;
} else {
info("link '%s' points to different target '%s', delete it", filename, target);
unlink(filename);
}
}
/* create link */
info("creating symlink '%s' to '%s'", filename, linktarget);
selinux_setfscreatecon(filename, NULL, S_IFLNK);
if (symlink(linktarget, filename) != 0)
err("symlink(%s, %s) failed: %s", linktarget, filename, strerror(errno));
selinux_resetfscreatecon();
exit:
return 0;
}
int udev_node_add(struct udevice *udev, struct udevice *udev_old)
{
char filename[PATH_SIZE];
@ -205,13 +235,8 @@ int udev_node_add(struct udevice *udev, struct udevice *udev_old)
strlcat(linktarget, &udev->name[tail], sizeof(linktarget));
info("creating symlink '%s' to '%s'", filename, linktarget);
if (!udev->test_run) {
unlink(filename);
selinux_setfscreatecon(filename, NULL, S_IFLNK);
if (symlink(linktarget, filename) != 0)
err("symlink(%s, %s) failed: %s", linktarget, filename, strerror(errno));
selinux_resetfscreatecon();
}
if (!udev->test_run)
udev_node_symlink(udev, linktarget, filename);
strlcat(symlinks, filename, sizeof(symlinks));
strlcat(symlinks, " ", sizeof(symlinks));