^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0-or-later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /* -*- mode: c; c-basic-offset: 8; -*-
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * vim: noexpandtab sw=8 ts=8 sts=0:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * dir.c - Operations for configfs directories.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * Based on sysfs:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) * sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) * configfs Copyright (C) 2005 Oracle. All rights reserved.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #undef DEBUG
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/fs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <linux/fsnotify.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <linux/mount.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #include <linux/err.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) #include <linux/configfs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) #include "configfs_internal.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) * Protects mutations of configfs_dirent linkage together with proper i_mutex
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) * Also protects mutations of symlinks linkage to target configfs_dirent
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) * Mutators of configfs_dirent linkage must *both* have the proper inode locked
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) * and configfs_dirent_lock locked, in that order.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) * This allows one to safely traverse configfs_dirent trees and symlinks without
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) * having to lock inodes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) * Protects setting of CONFIGFS_USET_DROPPING: checking the flag
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) * unlocked is not reliable unless in detach_groups() called from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) * rmdir()/unregister() and from configfs_attach_group()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) DEFINE_SPINLOCK(configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) * All of link_obj/unlink_obj/link_group/unlink_group require that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) * subsys->su_mutex is held.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) * But parent configfs_subsystem is NULL when config_item is root.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) * Use this mutex when config_item is root.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) static DEFINE_MUTEX(configfs_subsystem_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) static void configfs_d_iput(struct dentry * dentry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) struct inode * inode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) struct configfs_dirent *sd = dentry->d_fsdata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) if (sd) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) /* Coordinate with configfs_readdir */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) spin_lock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) * Set sd->s_dentry to null only when this dentry is the one
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) * that is going to be killed. Otherwise configfs_d_iput may
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) * run just after configfs_attach_attr and set sd->s_dentry to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) * NULL even it's still in use.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) if (sd->s_dentry == dentry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) sd->s_dentry = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) spin_unlock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) configfs_put(sd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) iput(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) const struct dentry_operations configfs_dentry_ops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) .d_iput = configfs_d_iput,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) .d_delete = always_delete_dentry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) #ifdef CONFIG_LOCKDEP
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) * Helpers to make lockdep happy with our recursive locking of default groups'
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) * inodes (see configfs_attach_group() and configfs_detach_group()).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) * We put default groups i_mutexes in separate classes according to their depth
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) * from the youngest non-default group ancestor.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) * For a non-default group A having default groups A/B, A/C, and A/C/D, default
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) * groups A/B and A/C will have their inode's mutex in class
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) * default_group_class[0], and default group A/C/D will be in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) * default_group_class[1].
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) * The lock classes are declared and assigned in inode.c, according to the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) * s_depth value.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) * The s_depth value is initialized to -1, adjusted to >= 0 when attaching
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) * default groups, and reset to -1 when all default groups are attached. During
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) * attachment, if configfs_create() sees s_depth > 0, the lock class of the new
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) * inode's mutex is set to default_group_class[s_depth - 1].
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) static void configfs_init_dirent_depth(struct configfs_dirent *sd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) sd->s_depth = -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) static void configfs_set_dir_dirent_depth(struct configfs_dirent *parent_sd,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) struct configfs_dirent *sd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) int parent_depth = parent_sd->s_depth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) if (parent_depth >= 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) sd->s_depth = parent_depth + 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) static void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) configfs_adjust_dir_dirent_depth_before_populate(struct configfs_dirent *sd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) * item's i_mutex class is already setup, so s_depth is now only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) * used to set new sub-directories s_depth, which is always done
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) * with item's i_mutex locked.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) * sd->s_depth == -1 iff we are a non default group.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) * else (we are a default group) sd->s_depth > 0 (see
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) * create_dir()).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) if (sd->s_depth == -1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) * We are a non default group and we are going to create
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) * default groups.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) sd->s_depth = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) static void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) configfs_adjust_dir_dirent_depth_after_populate(struct configfs_dirent *sd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) /* We will not create default groups anymore. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) sd->s_depth = -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) #else /* CONFIG_LOCKDEP */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) static void configfs_init_dirent_depth(struct configfs_dirent *sd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) static void configfs_set_dir_dirent_depth(struct configfs_dirent *parent_sd,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) struct configfs_dirent *sd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) static void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) configfs_adjust_dir_dirent_depth_before_populate(struct configfs_dirent *sd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) static void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) configfs_adjust_dir_dirent_depth_after_populate(struct configfs_dirent *sd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) #endif /* CONFIG_LOCKDEP */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) static struct configfs_fragment *new_fragment(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) struct configfs_fragment *p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) p = kmalloc(sizeof(struct configfs_fragment), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) if (p) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) atomic_set(&p->frag_count, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) init_rwsem(&p->frag_sem);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) p->frag_dead = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) return p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) void put_fragment(struct configfs_fragment *frag)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) if (frag && atomic_dec_and_test(&frag->frag_count))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) kfree(frag);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) struct configfs_fragment *get_fragment(struct configfs_fragment *frag)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) if (likely(frag))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) atomic_inc(&frag->frag_count);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) return frag;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) * Allocates a new configfs_dirent and links it to the parent configfs_dirent
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) static struct configfs_dirent *configfs_new_dirent(struct configfs_dirent *parent_sd,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) void *element, int type,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) struct configfs_fragment *frag)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) struct configfs_dirent * sd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) sd = kmem_cache_zalloc(configfs_dir_cachep, GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) if (!sd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) return ERR_PTR(-ENOMEM);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) atomic_set(&sd->s_count, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) INIT_LIST_HEAD(&sd->s_children);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) sd->s_element = element;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) sd->s_type = type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) configfs_init_dirent_depth(sd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) spin_lock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) if (parent_sd->s_type & CONFIGFS_USET_DROPPING) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) spin_unlock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) kmem_cache_free(configfs_dir_cachep, sd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) return ERR_PTR(-ENOENT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) sd->s_frag = get_fragment(frag);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) list_add(&sd->s_sibling, &parent_sd->s_children);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) spin_unlock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) return sd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) * Return -EEXIST if there is already a configfs element with the same
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) * name for the same parent.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) * called with parent inode's i_mutex held
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) static int configfs_dirent_exists(struct configfs_dirent *parent_sd,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) const unsigned char *new)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) struct configfs_dirent * sd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) if (sd->s_element) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) const unsigned char *existing = configfs_get_name(sd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) if (strcmp(existing, new))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) return -EEXIST;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) int configfs_make_dirent(struct configfs_dirent * parent_sd,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) struct dentry * dentry, void * element,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) umode_t mode, int type, struct configfs_fragment *frag)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) struct configfs_dirent * sd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) sd = configfs_new_dirent(parent_sd, element, type, frag);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) if (IS_ERR(sd))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) return PTR_ERR(sd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) sd->s_mode = mode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) sd->s_dentry = dentry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) if (dentry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) dentry->d_fsdata = configfs_get(sd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) static void configfs_remove_dirent(struct dentry *dentry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) struct configfs_dirent *sd = dentry->d_fsdata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) if (!sd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) spin_lock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) list_del_init(&sd->s_sibling);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) spin_unlock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) configfs_put(sd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) * configfs_create_dir - create a directory for an config_item.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) * @item: config_itemwe're creating directory for.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) * @dentry: config_item's dentry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) * Note: user-created entries won't be allowed under this new directory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) * until it is validated by configfs_dir_set_ready()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) static int configfs_create_dir(struct config_item *item, struct dentry *dentry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) struct configfs_fragment *frag)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) int error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) struct dentry *p = dentry->d_parent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) struct inode *inode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) BUG_ON(!item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) error = configfs_dirent_exists(p->d_fsdata, dentry->d_name.name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) if (unlikely(error))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) return error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) error = configfs_make_dirent(p->d_fsdata, dentry, item, mode,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) CONFIGFS_DIR | CONFIGFS_USET_CREATING,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) frag);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) if (unlikely(error))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) return error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) configfs_set_dir_dirent_depth(p->d_fsdata, dentry->d_fsdata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) inode = configfs_create(dentry, mode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) if (IS_ERR(inode))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) goto out_remove;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) inode->i_op = &configfs_dir_inode_operations;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) inode->i_fop = &configfs_dir_operations;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) /* directory inodes start off with i_nlink == 2 (for "." entry) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) inc_nlink(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) d_instantiate(dentry, inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) /* already hashed */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) dget(dentry); /* pin directory dentries in core */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) inc_nlink(d_inode(p));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) item->ci_dentry = dentry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) out_remove:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) configfs_remove_dirent(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) return PTR_ERR(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) * Allow userspace to create new entries under a new directory created with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) * configfs_create_dir(), and under all of its chidlren directories recursively.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) * @sd configfs_dirent of the new directory to validate
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) * Caller must hold configfs_dirent_lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) static void configfs_dir_set_ready(struct configfs_dirent *sd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) struct configfs_dirent *child_sd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) sd->s_type &= ~CONFIGFS_USET_CREATING;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) list_for_each_entry(child_sd, &sd->s_children, s_sibling)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) if (child_sd->s_type & CONFIGFS_USET_CREATING)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) configfs_dir_set_ready(child_sd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) * Check that a directory does not belong to a directory hierarchy being
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) * attached and not validated yet.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) * @sd configfs_dirent of the directory to check
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) * @return non-zero iff the directory was validated
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) * Note: takes configfs_dirent_lock, so the result may change from false to true
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) * in two consecutive calls, but never from true to false.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) int configfs_dirent_is_ready(struct configfs_dirent *sd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) spin_lock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) ret = !(sd->s_type & CONFIGFS_USET_CREATING);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) spin_unlock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) int configfs_create_link(struct configfs_dirent *target, struct dentry *parent,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) struct dentry *dentry, char *body)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) int err = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) umode_t mode = S_IFLNK | S_IRWXUGO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) struct configfs_dirent *p = parent->d_fsdata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) struct inode *inode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) err = configfs_make_dirent(p, dentry, target, mode, CONFIGFS_ITEM_LINK,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) p->s_frag);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) inode = configfs_create(dentry, mode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) if (IS_ERR(inode))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) goto out_remove;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) inode->i_link = body;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) inode->i_op = &configfs_symlink_inode_operations;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) d_instantiate(dentry, inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) dget(dentry); /* pin link dentries in core */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) out_remove:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) configfs_remove_dirent(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) return PTR_ERR(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) static void remove_dir(struct dentry * d)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) struct dentry * parent = dget(d->d_parent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) configfs_remove_dirent(d);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) if (d_really_is_positive(d))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) simple_rmdir(d_inode(parent),d);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) pr_debug(" o %pd removing done (%d)\n", d, d_count(d));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) dput(parent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) * configfs_remove_dir - remove an config_item's directory.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) * @item: config_item we're removing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) * The only thing special about this is that we remove any files in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) * the directory before we remove the directory, and we've inlined
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) * what used to be configfs_rmdir() below, instead of calling separately.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) * Caller holds the mutex of the item's inode
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) static void configfs_remove_dir(struct config_item * item)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) struct dentry * dentry = dget(item->ci_dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) if (!dentry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) remove_dir(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) * Drop reference from dget() on entrance.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) dput(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) /* attaches attribute's configfs_dirent to the dentry corresponding to the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) * attribute file
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) static int configfs_attach_attr(struct configfs_dirent * sd, struct dentry * dentry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435) struct configfs_attribute * attr = sd->s_element;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) struct inode *inode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) spin_lock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) dentry->d_fsdata = configfs_get(sd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) sd->s_dentry = dentry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) spin_unlock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) inode = configfs_create(dentry, (attr->ca_mode & S_IALLUGO) | S_IFREG);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) if (IS_ERR(inode)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) configfs_put(sd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) return PTR_ERR(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) if (sd->s_type & CONFIGFS_ITEM_BIN_ATTR) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449) inode->i_size = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) inode->i_fop = &configfs_bin_file_operations;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) inode->i_size = PAGE_SIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) inode->i_fop = &configfs_file_operations;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) d_add(dentry, inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) static struct dentry * configfs_lookup(struct inode *dir,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) struct dentry *dentry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461) unsigned int flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) struct configfs_dirent * parent_sd = dentry->d_parent->d_fsdata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) struct configfs_dirent * sd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) int found = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466) int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469) * Fake invisibility if dir belongs to a group/default groups hierarchy
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470) * being attached
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472) * This forbids userspace to read/write attributes of items which may
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473) * not complete their initialization, since the dentries of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474) * attributes won't be instantiated.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476) err = -ENOENT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477) if (!configfs_dirent_is_ready(parent_sd))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480) list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481) if (sd->s_type & CONFIGFS_NOT_PINNED) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482) const unsigned char * name = configfs_get_name(sd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 484) if (strcmp(name, dentry->d_name.name))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 485) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 487) found = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 488) err = configfs_attach_attr(sd, dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 489) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 490) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 491) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 492)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 493) if (!found) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 494) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 495) * If it doesn't exist and it isn't a NOT_PINNED item,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 496) * it must be negative.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 497) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 498) if (dentry->d_name.len > NAME_MAX)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 499) return ERR_PTR(-ENAMETOOLONG);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 500) d_add(dentry, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 501) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 502) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 503)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 504) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 505) return ERR_PTR(err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 506) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 507)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 508) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 509) * Only subdirectories count here. Files (CONFIGFS_NOT_PINNED) are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 510) * attributes and are removed by rmdir(). We recurse, setting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 511) * CONFIGFS_USET_DROPPING on all children that are candidates for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 512) * default detach.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 513) * If there is an error, the caller will reset the flags via
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 514) * configfs_detach_rollback().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 515) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 516) static int configfs_detach_prep(struct dentry *dentry, struct dentry **wait)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 517) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 518) struct configfs_dirent *parent_sd = dentry->d_fsdata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 519) struct configfs_dirent *sd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 520) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 521)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 522) /* Mark that we're trying to drop the group */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 523) parent_sd->s_type |= CONFIGFS_USET_DROPPING;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 524)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 525) ret = -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 526) if (parent_sd->s_links)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 527) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 528)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 529) ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 530) list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 531) if (!sd->s_element ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 532) (sd->s_type & CONFIGFS_NOT_PINNED))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 533) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 534) if (sd->s_type & CONFIGFS_USET_DEFAULT) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 535) /* Abort if racing with mkdir() */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 536) if (sd->s_type & CONFIGFS_USET_IN_MKDIR) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 537) if (wait)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 538) *wait= dget(sd->s_dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 539) return -EAGAIN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 540) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 541)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 542) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 543) * Yup, recursive. If there's a problem, blame
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 544) * deep nesting of default_groups
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 545) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 546) ret = configfs_detach_prep(sd->s_dentry, wait);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 547) if (!ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 548) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 549) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 550) ret = -ENOTEMPTY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 551)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 552) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 553) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 554)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 555) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 556) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 557) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 558)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 559) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 560) * Walk the tree, resetting CONFIGFS_USET_DROPPING wherever it was
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 561) * set.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 562) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 563) static void configfs_detach_rollback(struct dentry *dentry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 564) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 565) struct configfs_dirent *parent_sd = dentry->d_fsdata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 566) struct configfs_dirent *sd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 567)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 568) parent_sd->s_type &= ~CONFIGFS_USET_DROPPING;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 569)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 570) list_for_each_entry(sd, &parent_sd->s_children, s_sibling)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 571) if (sd->s_type & CONFIGFS_USET_DEFAULT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 572) configfs_detach_rollback(sd->s_dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 573) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 574)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 575) static void detach_attrs(struct config_item * item)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 576) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 577) struct dentry * dentry = dget(item->ci_dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 578) struct configfs_dirent * parent_sd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 579) struct configfs_dirent * sd, * tmp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 580)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 581) if (!dentry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 582) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 583)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 584) pr_debug("configfs %s: dropping attrs for dir\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 585) dentry->d_name.name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 586)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 587) parent_sd = dentry->d_fsdata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 588) list_for_each_entry_safe(sd, tmp, &parent_sd->s_children, s_sibling) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 589) if (!sd->s_element || !(sd->s_type & CONFIGFS_NOT_PINNED))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 590) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 591) spin_lock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 592) list_del_init(&sd->s_sibling);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 593) spin_unlock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 594) configfs_drop_dentry(sd, dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 595) configfs_put(sd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 596) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 597)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 598) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 599) * Drop reference from dget() on entrance.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 600) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 601) dput(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 602) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 603)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 604) static int populate_attrs(struct config_item *item)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 605) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 606) const struct config_item_type *t = item->ci_type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 607) struct configfs_attribute *attr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 608) struct configfs_bin_attribute *bin_attr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 609) int error = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 610) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 611)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 612) if (!t)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 613) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 614) if (t->ct_attrs) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 615) for (i = 0; (attr = t->ct_attrs[i]) != NULL; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 616) if ((error = configfs_create_file(item, attr)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 617) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 618) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 619) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 620) if (t->ct_bin_attrs) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 621) for (i = 0; (bin_attr = t->ct_bin_attrs[i]) != NULL; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 622) error = configfs_create_bin_file(item, bin_attr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 623) if (error)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 624) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 625) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 626) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 627)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 628) if (error)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 629) detach_attrs(item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 630)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 631) return error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 632) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 633)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 634) static int configfs_attach_group(struct config_item *parent_item,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 635) struct config_item *item,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 636) struct dentry *dentry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 637) struct configfs_fragment *frag);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 638) static void configfs_detach_group(struct config_item *item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 639)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 640) static void detach_groups(struct config_group *group)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 641) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 642) struct dentry * dentry = dget(group->cg_item.ci_dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 643) struct dentry *child;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 644) struct configfs_dirent *parent_sd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 645) struct configfs_dirent *sd, *tmp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 646)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 647) if (!dentry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 648) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 649)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 650) parent_sd = dentry->d_fsdata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 651) list_for_each_entry_safe(sd, tmp, &parent_sd->s_children, s_sibling) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 652) if (!sd->s_element ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 653) !(sd->s_type & CONFIGFS_USET_DEFAULT))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 654) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 655)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 656) child = sd->s_dentry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 657)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 658) inode_lock(d_inode(child));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 659)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 660) configfs_detach_group(sd->s_element);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 661) d_inode(child)->i_flags |= S_DEAD;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 662) dont_mount(child);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 663)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 664) inode_unlock(d_inode(child));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 665)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 666) d_delete(child);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 667) dput(child);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 668) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 669)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 670) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 671) * Drop reference from dget() on entrance.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 672) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 673) dput(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 674) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 675)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 676) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 677) * This fakes mkdir(2) on a default_groups[] entry. It
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 678) * creates a dentry, attachs it, and then does fixup
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 679) * on the sd->s_type.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 680) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 681) * We could, perhaps, tweak our parent's ->mkdir for a minute and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 682) * try using vfs_mkdir. Just a thought.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 683) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 684) static int create_default_group(struct config_group *parent_group,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 685) struct config_group *group,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 686) struct configfs_fragment *frag)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 687) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 688) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 689) struct configfs_dirent *sd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 690) /* We trust the caller holds a reference to parent */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 691) struct dentry *child, *parent = parent_group->cg_item.ci_dentry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 692)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 693) if (!group->cg_item.ci_name)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 694) group->cg_item.ci_name = group->cg_item.ci_namebuf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 695)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 696) ret = -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 697) child = d_alloc_name(parent, group->cg_item.ci_name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 698) if (child) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 699) d_add(child, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 700)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 701) ret = configfs_attach_group(&parent_group->cg_item,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 702) &group->cg_item, child, frag);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 703) if (!ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 704) sd = child->d_fsdata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 705) sd->s_type |= CONFIGFS_USET_DEFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 706) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 707) BUG_ON(d_inode(child));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 708) d_drop(child);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 709) dput(child);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 710) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 711) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 712)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 713) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 714) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 715)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 716) static int populate_groups(struct config_group *group,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 717) struct configfs_fragment *frag)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 718) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 719) struct config_group *new_group;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 720) int ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 721)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 722) list_for_each_entry(new_group, &group->default_groups, group_entry) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 723) ret = create_default_group(group, new_group, frag);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 724) if (ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 725) detach_groups(group);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 726) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 727) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 728) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 729)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 730) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 731) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 732)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 733) void configfs_remove_default_groups(struct config_group *group)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 734) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 735) struct config_group *g, *n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 736)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 737) list_for_each_entry_safe(g, n, &group->default_groups, group_entry) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 738) list_del(&g->group_entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 739) config_item_put(&g->cg_item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 740) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 741) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 742) EXPORT_SYMBOL(configfs_remove_default_groups);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 743)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 744) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 745) * All of link_obj/unlink_obj/link_group/unlink_group require that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 746) * subsys->su_mutex is held.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 747) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 748)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 749) static void unlink_obj(struct config_item *item)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 750) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 751) struct config_group *group;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 752)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 753) group = item->ci_group;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 754) if (group) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 755) list_del_init(&item->ci_entry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 756)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 757) item->ci_group = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 758) item->ci_parent = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 759)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 760) /* Drop the reference for ci_entry */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 761) config_item_put(item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 762)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 763) /* Drop the reference for ci_parent */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 764) config_group_put(group);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 765) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 766) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 767)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 768) static void link_obj(struct config_item *parent_item, struct config_item *item)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 769) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 770) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 771) * Parent seems redundant with group, but it makes certain
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 772) * traversals much nicer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 773) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 774) item->ci_parent = parent_item;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 775)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 776) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 777) * We hold a reference on the parent for the child's ci_parent
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 778) * link.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 779) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 780) item->ci_group = config_group_get(to_config_group(parent_item));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 781) list_add_tail(&item->ci_entry, &item->ci_group->cg_children);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 782)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 783) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 784) * We hold a reference on the child for ci_entry on the parent's
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 785) * cg_children
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 786) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 787) config_item_get(item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 788) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 789)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 790) static void unlink_group(struct config_group *group)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 791) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 792) struct config_group *new_group;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 793)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 794) list_for_each_entry(new_group, &group->default_groups, group_entry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 795) unlink_group(new_group);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 796)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 797) group->cg_subsys = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 798) unlink_obj(&group->cg_item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 799) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 800)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 801) static void link_group(struct config_group *parent_group, struct config_group *group)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 802) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 803) struct config_group *new_group;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 804) struct configfs_subsystem *subsys = NULL; /* gcc is a turd */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 805)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 806) link_obj(&parent_group->cg_item, &group->cg_item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 807)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 808) if (parent_group->cg_subsys)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 809) subsys = parent_group->cg_subsys;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 810) else if (configfs_is_root(&parent_group->cg_item))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 811) subsys = to_configfs_subsystem(group);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 812) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 813) BUG();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 814) group->cg_subsys = subsys;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 815)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 816) list_for_each_entry(new_group, &group->default_groups, group_entry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 817) link_group(group, new_group);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 818) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 819)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 820) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 821) * The goal is that configfs_attach_item() (and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 822) * configfs_attach_group()) can be called from either the VFS or this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 823) * module. That is, they assume that the items have been created,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 824) * the dentry allocated, and the dcache is all ready to go.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 825) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 826) * If they fail, they must clean up after themselves as if they
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 827) * had never been called. The caller (VFS or local function) will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 828) * handle cleaning up the dcache bits.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 829) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 830) * configfs_detach_group() and configfs_detach_item() behave similarly on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 831) * the way out. They assume that the proper semaphores are held, they
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 832) * clean up the configfs items, and they expect their callers will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 833) * handle the dcache bits.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 834) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 835) static int configfs_attach_item(struct config_item *parent_item,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 836) struct config_item *item,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 837) struct dentry *dentry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 838) struct configfs_fragment *frag)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 839) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 840) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 841)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 842) ret = configfs_create_dir(item, dentry, frag);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 843) if (!ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 844) ret = populate_attrs(item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 845) if (ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 846) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 847) * We are going to remove an inode and its dentry but
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 848) * the VFS may already have hit and used them. Thus,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 849) * we must lock them as rmdir() would.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 850) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 851) inode_lock(d_inode(dentry));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 852) configfs_remove_dir(item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 853) d_inode(dentry)->i_flags |= S_DEAD;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 854) dont_mount(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 855) inode_unlock(d_inode(dentry));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 856) d_delete(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 857) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 858) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 859)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 860) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 861) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 862)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 863) /* Caller holds the mutex of the item's inode */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 864) static void configfs_detach_item(struct config_item *item)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 865) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 866) detach_attrs(item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 867) configfs_remove_dir(item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 868) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 869)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 870) static int configfs_attach_group(struct config_item *parent_item,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 871) struct config_item *item,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 872) struct dentry *dentry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 873) struct configfs_fragment *frag)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 874) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 875) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 876) struct configfs_dirent *sd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 877)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 878) ret = configfs_attach_item(parent_item, item, dentry, frag);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 879) if (!ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 880) sd = dentry->d_fsdata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 881) sd->s_type |= CONFIGFS_USET_DIR;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 882)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 883) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 884) * FYI, we're faking mkdir in populate_groups()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 885) * We must lock the group's inode to avoid races with the VFS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 886) * which can already hit the inode and try to add/remove entries
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 887) * under it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 888) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 889) * We must also lock the inode to remove it safely in case of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 890) * error, as rmdir() would.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 891) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 892) inode_lock_nested(d_inode(dentry), I_MUTEX_CHILD);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 893) configfs_adjust_dir_dirent_depth_before_populate(sd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 894) ret = populate_groups(to_config_group(item), frag);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 895) if (ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 896) configfs_detach_item(item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 897) d_inode(dentry)->i_flags |= S_DEAD;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 898) dont_mount(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 899) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 900) configfs_adjust_dir_dirent_depth_after_populate(sd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 901) inode_unlock(d_inode(dentry));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 902) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 903) d_delete(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 904) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 905)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 906) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 907) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 908)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 909) /* Caller holds the mutex of the group's inode */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 910) static void configfs_detach_group(struct config_item *item)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 911) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 912) detach_groups(to_config_group(item));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 913) configfs_detach_item(item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 914) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 915)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 916) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 917) * After the item has been detached from the filesystem view, we are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 918) * ready to tear it out of the hierarchy. Notify the client before
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 919) * we do that so they can perform any cleanup that requires
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 920) * navigating the hierarchy. A client does not need to provide this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 921) * callback. The subsystem semaphore MUST be held by the caller, and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 922) * references must be valid for both items. It also assumes the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 923) * caller has validated ci_type.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 924) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 925) static void client_disconnect_notify(struct config_item *parent_item,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 926) struct config_item *item)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 927) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 928) const struct config_item_type *type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 929)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 930) type = parent_item->ci_type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 931) BUG_ON(!type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 932)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 933) if (type->ct_group_ops && type->ct_group_ops->disconnect_notify)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 934) type->ct_group_ops->disconnect_notify(to_config_group(parent_item),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 935) item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 936) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 937)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 938) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 939) * Drop the initial reference from make_item()/make_group()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 940) * This function assumes that reference is held on item
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 941) * and that item holds a valid reference to the parent. Also, it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 942) * assumes the caller has validated ci_type.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 943) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 944) static void client_drop_item(struct config_item *parent_item,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 945) struct config_item *item)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 946) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 947) const struct config_item_type *type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 948)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 949) type = parent_item->ci_type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 950) BUG_ON(!type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 951)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 952) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 953) * If ->drop_item() exists, it is responsible for the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 954) * config_item_put().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 955) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 956) if (type->ct_group_ops && type->ct_group_ops->drop_item)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 957) type->ct_group_ops->drop_item(to_config_group(parent_item),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 958) item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 959) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 960) config_item_put(item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 961) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 962)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 963) #ifdef DEBUG
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 964) static void configfs_dump_one(struct configfs_dirent *sd, int level)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 965) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 966) pr_info("%*s\"%s\":\n", level, " ", configfs_get_name(sd));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 967)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 968) #define type_print(_type) if (sd->s_type & _type) pr_info("%*s %s\n", level, " ", #_type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 969) type_print(CONFIGFS_ROOT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 970) type_print(CONFIGFS_DIR);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 971) type_print(CONFIGFS_ITEM_ATTR);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 972) type_print(CONFIGFS_ITEM_LINK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 973) type_print(CONFIGFS_USET_DIR);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 974) type_print(CONFIGFS_USET_DEFAULT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 975) type_print(CONFIGFS_USET_DROPPING);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 976) #undef type_print
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 977) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 978)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 979) static int configfs_dump(struct configfs_dirent *sd, int level)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 980) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 981) struct configfs_dirent *child_sd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 982) int ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 983)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 984) configfs_dump_one(sd, level);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 985)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 986) if (!(sd->s_type & (CONFIGFS_DIR|CONFIGFS_ROOT)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 987) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 988)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 989) list_for_each_entry(child_sd, &sd->s_children, s_sibling) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 990) ret = configfs_dump(child_sd, level + 2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 991) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 992) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 993) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 994)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 995) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 996) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 997) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 998)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 999)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1000) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1001) * configfs_depend_item() and configfs_undepend_item()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1002) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1003) * WARNING: Do not call these from a configfs callback!
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1004) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1005) * This describes these functions and their helpers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1006) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1007) * Allow another kernel system to depend on a config_item. If this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1008) * happens, the item cannot go away until the dependent can live without
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1009) * it. The idea is to give client modules as simple an interface as
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1010) * possible. When a system asks them to depend on an item, they just
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1011) * call configfs_depend_item(). If the item is live and the client
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1012) * driver is in good shape, we'll happily do the work for them.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1013) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1014) * Why is the locking complex? Because configfs uses the VFS to handle
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1015) * all locking, but this function is called outside the normal
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1016) * VFS->configfs path. So it must take VFS locks to prevent the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1017) * VFS->configfs stuff (configfs_mkdir(), configfs_rmdir(), etc). This is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1018) * why you can't call these functions underneath configfs callbacks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1019) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1020) * Note, btw, that this can be called at *any* time, even when a configfs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1021) * subsystem isn't registered, or when configfs is loading or unloading.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1022) * Just like configfs_register_subsystem(). So we take the same
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1023) * precautions. We pin the filesystem. We lock configfs_dirent_lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1024) * If we can find the target item in the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1025) * configfs tree, it must be part of the subsystem tree as well, so we
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1026) * do not need the subsystem semaphore. Holding configfs_dirent_lock helps
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1027) * locking out mkdir() and rmdir(), who might be racing us.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1028) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1029)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1030) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1031) * configfs_depend_prep()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1032) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1033) * Only subdirectories count here. Files (CONFIGFS_NOT_PINNED) are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1034) * attributes. This is similar but not the same to configfs_detach_prep().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1035) * Note that configfs_detach_prep() expects the parent to be locked when it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1036) * is called, but we lock the parent *inside* configfs_depend_prep(). We
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1037) * do that so we can unlock it if we find nothing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1038) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1039) * Here we do a depth-first search of the dentry hierarchy looking for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1040) * our object.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1041) * We deliberately ignore items tagged as dropping since they are virtually
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1042) * dead, as well as items in the middle of attachment since they virtually
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1043) * do not exist yet. This completes the locking out of racing mkdir() and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1044) * rmdir().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1045) * Note: subdirectories in the middle of attachment start with s_type =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1046) * CONFIGFS_DIR|CONFIGFS_USET_CREATING set by create_dir(). When
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1047) * CONFIGFS_USET_CREATING is set, we ignore the item. The actual set of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1048) * s_type is in configfs_new_dirent(), which has configfs_dirent_lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1049) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1050) * If the target is not found, -ENOENT is bubbled up.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1051) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1052) * This adds a requirement that all config_items be unique!
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1053) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1054) * This is recursive. There isn't
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1055) * much on the stack, though, so folks that need this function - be careful
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1056) * about your stack! Patches will be accepted to make it iterative.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1057) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1058) static int configfs_depend_prep(struct dentry *origin,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1059) struct config_item *target)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1060) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1061) struct configfs_dirent *child_sd, *sd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1062) int ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1063)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1064) BUG_ON(!origin || !origin->d_fsdata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1065) sd = origin->d_fsdata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1066)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1067) if (sd->s_element == target) /* Boo-yah */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1068) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1069)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1070) list_for_each_entry(child_sd, &sd->s_children, s_sibling) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1071) if ((child_sd->s_type & CONFIGFS_DIR) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1072) !(child_sd->s_type & CONFIGFS_USET_DROPPING) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1073) !(child_sd->s_type & CONFIGFS_USET_CREATING)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1074) ret = configfs_depend_prep(child_sd->s_dentry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1075) target);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1076) if (!ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1077) goto out; /* Child path boo-yah */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1078) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1079) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1080)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1081) /* We looped all our children and didn't find target */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1082) ret = -ENOENT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1083)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1084) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1085) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1086) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1087)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1088) static int configfs_do_depend_item(struct dentry *subsys_dentry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1089) struct config_item *target)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1090) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1091) struct configfs_dirent *p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1092) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1093)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1094) spin_lock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1095) /* Scan the tree, return 0 if found */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1096) ret = configfs_depend_prep(subsys_dentry, target);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1097) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1098) goto out_unlock_dirent_lock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1099)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1100) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1101) * We are sure that the item is not about to be removed by rmdir(), and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1102) * not in the middle of attachment by mkdir().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1103) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1104) p = target->ci_dentry->d_fsdata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1105) p->s_dependent_count += 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1106)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1107) out_unlock_dirent_lock:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1108) spin_unlock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1109)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1110) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1111) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1112)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1113) static inline struct configfs_dirent *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1114) configfs_find_subsys_dentry(struct configfs_dirent *root_sd,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1115) struct config_item *subsys_item)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1116) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1117) struct configfs_dirent *p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1118) struct configfs_dirent *ret = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1119)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1120) list_for_each_entry(p, &root_sd->s_children, s_sibling) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1121) if (p->s_type & CONFIGFS_DIR &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1122) p->s_element == subsys_item) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1123) ret = p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1124) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1125) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1126) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1127)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1128) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1129) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1130)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1131)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1132) int configfs_depend_item(struct configfs_subsystem *subsys,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1133) struct config_item *target)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1134) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1135) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1136) struct configfs_dirent *subsys_sd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1137) struct config_item *s_item = &subsys->su_group.cg_item;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1138) struct dentry *root;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1139)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1140) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1141) * Pin the configfs filesystem. This means we can safely access
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1142) * the root of the configfs filesystem.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1143) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1144) root = configfs_pin_fs();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1145) if (IS_ERR(root))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1146) return PTR_ERR(root);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1147)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1148) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1149) * Next, lock the root directory. We're going to check that the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1150) * subsystem is really registered, and so we need to lock out
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1151) * configfs_[un]register_subsystem().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1152) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1153) inode_lock(d_inode(root));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1154)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1155) subsys_sd = configfs_find_subsys_dentry(root->d_fsdata, s_item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1156) if (!subsys_sd) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1157) ret = -ENOENT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1158) goto out_unlock_fs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1159) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1160)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1161) /* Ok, now we can trust subsys/s_item */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1162) ret = configfs_do_depend_item(subsys_sd->s_dentry, target);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1163)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1164) out_unlock_fs:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1165) inode_unlock(d_inode(root));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1166)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1167) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1168) * If we succeeded, the fs is pinned via other methods. If not,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1169) * we're done with it anyway. So release_fs() is always right.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1170) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1171) configfs_release_fs();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1172)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1173) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1174) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1175) EXPORT_SYMBOL(configfs_depend_item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1176)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1177) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1178) * Release the dependent linkage. This is much simpler than
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1179) * configfs_depend_item() because we know that the client driver is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1180) * pinned, thus the subsystem is pinned, and therefore configfs is pinned.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1181) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1182) void configfs_undepend_item(struct config_item *target)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1183) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1184) struct configfs_dirent *sd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1185)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1186) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1187) * Since we can trust everything is pinned, we just need
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1188) * configfs_dirent_lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1189) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1190) spin_lock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1191)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1192) sd = target->ci_dentry->d_fsdata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1193) BUG_ON(sd->s_dependent_count < 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1194)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1195) sd->s_dependent_count -= 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1196)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1197) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1198) * After this unlock, we cannot trust the item to stay alive!
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1199) * DO NOT REFERENCE item after this unlock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1200) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1201) spin_unlock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1202) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1203) EXPORT_SYMBOL(configfs_undepend_item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1204)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1205) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1206) * caller_subsys is a caller's subsystem not target's. This is used to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1207) * determine if we should lock root and check subsys or not. When we are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1208) * in the same subsystem as our target there is no need to do locking as
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1209) * we know that subsys is valid and is not unregistered during this function
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1210) * as we are called from callback of one of his children and VFS holds a lock
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1211) * on some inode. Otherwise we have to lock our root to ensure that target's
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1212) * subsystem it is not unregistered during this function.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1213) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1214) int configfs_depend_item_unlocked(struct configfs_subsystem *caller_subsys,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1215) struct config_item *target)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1216) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1217) struct configfs_subsystem *target_subsys;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1218) struct config_group *root, *parent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1219) struct configfs_dirent *subsys_sd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1220) int ret = -ENOENT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1221)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1222) /* Disallow this function for configfs root */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1223) if (configfs_is_root(target))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1224) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1225)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1226) parent = target->ci_group;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1227) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1228) * This may happen when someone is trying to depend root
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1229) * directory of some subsystem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1230) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1231) if (configfs_is_root(&parent->cg_item)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1232) target_subsys = to_configfs_subsystem(to_config_group(target));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1233) root = parent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1234) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1235) target_subsys = parent->cg_subsys;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1236) /* Find a cofnigfs root as we may need it for locking */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1237) for (root = parent; !configfs_is_root(&root->cg_item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1238) root = root->cg_item.ci_group)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1239) ;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1240) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1241)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1242) if (target_subsys != caller_subsys) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1243) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1244) * We are in other configfs subsystem, so we have to do
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1245) * additional locking to prevent other subsystem from being
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1246) * unregistered
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1247) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1248) inode_lock(d_inode(root->cg_item.ci_dentry));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1249)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1250) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1251) * As we are trying to depend item from other subsystem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1252) * we have to check if this subsystem is still registered
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1253) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1254) subsys_sd = configfs_find_subsys_dentry(
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1255) root->cg_item.ci_dentry->d_fsdata,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1256) &target_subsys->su_group.cg_item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1257) if (!subsys_sd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1258) goto out_root_unlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1259) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1260) subsys_sd = target_subsys->su_group.cg_item.ci_dentry->d_fsdata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1261) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1262)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1263) /* Now we can execute core of depend item */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1264) ret = configfs_do_depend_item(subsys_sd->s_dentry, target);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1265)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1266) if (target_subsys != caller_subsys)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1267) out_root_unlock:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1268) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1269) * We were called from subsystem other than our target so we
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1270) * took some locks so now it's time to release them
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1271) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1272) inode_unlock(d_inode(root->cg_item.ci_dentry));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1273)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1274) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1275) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1276) EXPORT_SYMBOL(configfs_depend_item_unlocked);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1277)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1278) static int configfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1279) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1280) int ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1281) int module_got = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1282) struct config_group *group = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1283) struct config_item *item = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1284) struct config_item *parent_item;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1285) struct configfs_subsystem *subsys;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1286) struct configfs_dirent *sd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1287) const struct config_item_type *type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1288) struct module *subsys_owner = NULL, *new_item_owner = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1289) struct configfs_fragment *frag;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1290) char *name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1291)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1292) sd = dentry->d_parent->d_fsdata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1293)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1294) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1295) * Fake invisibility if dir belongs to a group/default groups hierarchy
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1296) * being attached
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1297) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1298) if (!configfs_dirent_is_ready(sd)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1299) ret = -ENOENT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1300) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1301) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1302)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1303) if (!(sd->s_type & CONFIGFS_USET_DIR)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1304) ret = -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1305) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1306) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1307)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1308) frag = new_fragment();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1309) if (!frag) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1310) ret = -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1311) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1312) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1313)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1314) /* Get a working ref for the duration of this function */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1315) parent_item = configfs_get_config_item(dentry->d_parent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1316) type = parent_item->ci_type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1317) subsys = to_config_group(parent_item)->cg_subsys;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1318) BUG_ON(!subsys);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1319)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1320) if (!type || !type->ct_group_ops ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1321) (!type->ct_group_ops->make_group &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1322) !type->ct_group_ops->make_item)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1323) ret = -EPERM; /* Lack-of-mkdir returns -EPERM */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1324) goto out_put;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1325) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1326)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1327) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1328) * The subsystem may belong to a different module than the item
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1329) * being created. We don't want to safely pin the new item but
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1330) * fail to pin the subsystem it sits under.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1331) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1332) if (!subsys->su_group.cg_item.ci_type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1333) ret = -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1334) goto out_put;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1335) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1336) subsys_owner = subsys->su_group.cg_item.ci_type->ct_owner;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1337) if (!try_module_get(subsys_owner)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1338) ret = -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1339) goto out_put;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1340) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1341)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1342) name = kmalloc(dentry->d_name.len + 1, GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1343) if (!name) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1344) ret = -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1345) goto out_subsys_put;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1346) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1347)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1348) snprintf(name, dentry->d_name.len + 1, "%s", dentry->d_name.name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1349)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1350) mutex_lock(&subsys->su_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1351) if (type->ct_group_ops->make_group) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1352) group = type->ct_group_ops->make_group(to_config_group(parent_item), name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1353) if (!group)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1354) group = ERR_PTR(-ENOMEM);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1355) if (!IS_ERR(group)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1356) link_group(to_config_group(parent_item), group);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1357) item = &group->cg_item;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1358) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1359) ret = PTR_ERR(group);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1360) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1361) item = type->ct_group_ops->make_item(to_config_group(parent_item), name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1362) if (!item)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1363) item = ERR_PTR(-ENOMEM);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1364) if (!IS_ERR(item))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1365) link_obj(parent_item, item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1366) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1367) ret = PTR_ERR(item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1368) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1369) mutex_unlock(&subsys->su_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1370)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1371) kfree(name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1372) if (ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1373) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1374) * If ret != 0, then link_obj() was never called.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1375) * There are no extra references to clean up.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1376) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1377) goto out_subsys_put;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1378) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1379)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1380) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1381) * link_obj() has been called (via link_group() for groups).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1382) * From here on out, errors must clean that up.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1383) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1384)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1385) type = item->ci_type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1386) if (!type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1387) ret = -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1388) goto out_unlink;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1389) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1390)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1391) new_item_owner = type->ct_owner;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1392) if (!try_module_get(new_item_owner)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1393) ret = -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1394) goto out_unlink;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1395) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1396)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1397) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1398) * I hate doing it this way, but if there is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1399) * an error, module_put() probably should
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1400) * happen after any cleanup.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1401) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1402) module_got = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1403)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1404) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1405) * Make racing rmdir() fail if it did not tag parent with
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1406) * CONFIGFS_USET_DROPPING
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1407) * Note: if CONFIGFS_USET_DROPPING is already set, attach_group() will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1408) * fail and let rmdir() terminate correctly
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1409) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1410) spin_lock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1411) /* This will make configfs_detach_prep() fail */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1412) sd->s_type |= CONFIGFS_USET_IN_MKDIR;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1413) spin_unlock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1414)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1415) if (group)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1416) ret = configfs_attach_group(parent_item, item, dentry, frag);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1417) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1418) ret = configfs_attach_item(parent_item, item, dentry, frag);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1419)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1420) /* inherit uid/gid from process creating the directory */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1421) if (!uid_eq(current_fsuid(), GLOBAL_ROOT_UID) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1422) !gid_eq(current_fsgid(), GLOBAL_ROOT_GID)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1423) struct iattr ia = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1424) .ia_uid = current_fsuid(),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1425) .ia_gid = current_fsgid(),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1426) .ia_valid = ATTR_UID | ATTR_GID,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1427) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1428) struct inode *inode = d_inode(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1429) inode->i_uid = ia.ia_uid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1430) inode->i_gid = ia.ia_gid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1431) /* the above manual assignments skip the permission checks */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1432) configfs_setattr(dentry, &ia);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1433) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1434)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1435) spin_lock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1436) sd->s_type &= ~CONFIGFS_USET_IN_MKDIR;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1437) if (!ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1438) configfs_dir_set_ready(dentry->d_fsdata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1439) spin_unlock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1440)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1441) out_unlink:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1442) if (ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1443) /* Tear down everything we built up */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1444) mutex_lock(&subsys->su_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1445)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1446) client_disconnect_notify(parent_item, item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1447) if (group)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1448) unlink_group(group);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1449) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1450) unlink_obj(item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1451) client_drop_item(parent_item, item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1452)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1453) mutex_unlock(&subsys->su_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1454)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1455) if (module_got)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1456) module_put(new_item_owner);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1457) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1458)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1459) out_subsys_put:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1460) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1461) module_put(subsys_owner);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1462)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1463) out_put:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1464) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1465) * link_obj()/link_group() took a reference from child->parent,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1466) * so the parent is safely pinned. We can drop our working
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1467) * reference.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1468) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1469) config_item_put(parent_item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1470) put_fragment(frag);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1471)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1472) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1473) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1474) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1475)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1476) static int configfs_rmdir(struct inode *dir, struct dentry *dentry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1477) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1478) struct config_item *parent_item;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1479) struct config_item *item;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1480) struct configfs_subsystem *subsys;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1481) struct configfs_dirent *sd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1482) struct configfs_fragment *frag;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1483) struct module *subsys_owner = NULL, *dead_item_owner = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1484) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1485)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1486) sd = dentry->d_fsdata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1487) if (sd->s_type & CONFIGFS_USET_DEFAULT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1488) return -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1489)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1490) /* Get a working ref until we have the child */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1491) parent_item = configfs_get_config_item(dentry->d_parent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1492) subsys = to_config_group(parent_item)->cg_subsys;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1493) BUG_ON(!subsys);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1494)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1495) if (!parent_item->ci_type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1496) config_item_put(parent_item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1497) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1498) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1499)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1500) /* configfs_mkdir() shouldn't have allowed this */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1501) BUG_ON(!subsys->su_group.cg_item.ci_type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1502) subsys_owner = subsys->su_group.cg_item.ci_type->ct_owner;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1503)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1504) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1505) * Ensure that no racing symlink() will make detach_prep() fail while
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1506) * the new link is temporarily attached
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1507) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1508) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1509) struct dentry *wait;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1510)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1511) mutex_lock(&configfs_symlink_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1512) spin_lock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1513) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1514) * Here's where we check for dependents. We're protected by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1515) * configfs_dirent_lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1516) * If no dependent, atomically tag the item as dropping.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1517) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1518) ret = sd->s_dependent_count ? -EBUSY : 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1519) if (!ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1520) ret = configfs_detach_prep(dentry, &wait);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1521) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1522) configfs_detach_rollback(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1523) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1524) spin_unlock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1525) mutex_unlock(&configfs_symlink_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1526)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1527) if (ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1528) if (ret != -EAGAIN) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1529) config_item_put(parent_item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1530) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1531) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1532)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1533) /* Wait until the racing operation terminates */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1534) inode_lock(d_inode(wait));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1535) inode_unlock(d_inode(wait));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1536) dput(wait);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1537) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1538) } while (ret == -EAGAIN);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1539)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1540) frag = sd->s_frag;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1541) if (down_write_killable(&frag->frag_sem)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1542) spin_lock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1543) configfs_detach_rollback(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1544) spin_unlock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1545) config_item_put(parent_item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1546) return -EINTR;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1547) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1548) frag->frag_dead = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1549) up_write(&frag->frag_sem);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1550)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1551) /* Get a working ref for the duration of this function */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1552) item = configfs_get_config_item(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1553)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1554) /* Drop reference from above, item already holds one. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1555) config_item_put(parent_item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1556)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1557) if (item->ci_type)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1558) dead_item_owner = item->ci_type->ct_owner;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1559)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1560) if (sd->s_type & CONFIGFS_USET_DIR) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1561) configfs_detach_group(item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1562)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1563) mutex_lock(&subsys->su_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1564) client_disconnect_notify(parent_item, item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1565) unlink_group(to_config_group(item));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1566) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1567) configfs_detach_item(item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1568)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1569) mutex_lock(&subsys->su_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1570) client_disconnect_notify(parent_item, item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1571) unlink_obj(item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1572) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1573)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1574) client_drop_item(parent_item, item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1575) mutex_unlock(&subsys->su_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1576)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1577) /* Drop our reference from above */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1578) config_item_put(item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1579)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1580) module_put(dead_item_owner);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1581) module_put(subsys_owner);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1582)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1583) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1584) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1585)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1586) const struct inode_operations configfs_dir_inode_operations = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1587) .mkdir = configfs_mkdir,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1588) .rmdir = configfs_rmdir,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1589) .symlink = configfs_symlink,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1590) .unlink = configfs_unlink,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1591) .lookup = configfs_lookup,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1592) .setattr = configfs_setattr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1593) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1594)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1595) const struct inode_operations configfs_root_inode_operations = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1596) .lookup = configfs_lookup,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1597) .setattr = configfs_setattr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1598) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1599)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1600) static int configfs_dir_open(struct inode *inode, struct file *file)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1601) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1602) struct dentry * dentry = file->f_path.dentry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1603) struct configfs_dirent * parent_sd = dentry->d_fsdata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1604) int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1605)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1606) inode_lock(d_inode(dentry));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1607) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1608) * Fake invisibility if dir belongs to a group/default groups hierarchy
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1609) * being attached
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1610) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1611) err = -ENOENT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1612) if (configfs_dirent_is_ready(parent_sd)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1613) file->private_data = configfs_new_dirent(parent_sd, NULL, 0, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1614) if (IS_ERR(file->private_data))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1615) err = PTR_ERR(file->private_data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1616) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1617) err = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1618) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1619) inode_unlock(d_inode(dentry));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1620)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1621) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1622) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1623)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1624) static int configfs_dir_close(struct inode *inode, struct file *file)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1625) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1626) struct dentry * dentry = file->f_path.dentry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1627) struct configfs_dirent * cursor = file->private_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1628)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1629) inode_lock(d_inode(dentry));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1630) spin_lock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1631) list_del_init(&cursor->s_sibling);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1632) spin_unlock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1633) inode_unlock(d_inode(dentry));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1634)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1635) release_configfs_dirent(cursor);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1636)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1637) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1638) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1639)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1640) /* Relationship between s_mode and the DT_xxx types */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1641) static inline unsigned char dt_type(struct configfs_dirent *sd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1642) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1643) return (sd->s_mode >> 12) & 15;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1644) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1645)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1646) static int configfs_readdir(struct file *file, struct dir_context *ctx)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1647) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1648) struct dentry *dentry = file->f_path.dentry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1649) struct super_block *sb = dentry->d_sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1650) struct configfs_dirent * parent_sd = dentry->d_fsdata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1651) struct configfs_dirent *cursor = file->private_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1652) struct list_head *p, *q = &cursor->s_sibling;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1653) ino_t ino = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1654)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1655) if (!dir_emit_dots(file, ctx))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1656) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1657) spin_lock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1658) if (ctx->pos == 2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1659) list_move(q, &parent_sd->s_children);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1660) for (p = q->next; p != &parent_sd->s_children; p = p->next) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1661) struct configfs_dirent *next;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1662) const char *name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1663) int len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1664) struct inode *inode = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1665)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1666) next = list_entry(p, struct configfs_dirent, s_sibling);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1667) if (!next->s_element)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1668) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1669)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1670) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1671) * We'll have a dentry and an inode for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1672) * PINNED items and for open attribute
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1673) * files. We lock here to prevent a race
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1674) * with configfs_d_iput() clearing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1675) * s_dentry before calling iput().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1676) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1677) * Why do we go to the trouble? If
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1678) * someone has an attribute file open,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1679) * the inode number should match until
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1680) * they close it. Beyond that, we don't
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1681) * care.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1682) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1683) dentry = next->s_dentry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1684) if (dentry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1685) inode = d_inode(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1686) if (inode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1687) ino = inode->i_ino;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1688) spin_unlock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1689) if (!inode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1690) ino = iunique(sb, 2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1691)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1692) name = configfs_get_name(next);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1693) len = strlen(name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1694)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1695) if (!dir_emit(ctx, name, len, ino, dt_type(next)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1696) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1697)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1698) spin_lock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1699) list_move(q, p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1700) p = q;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1701) ctx->pos++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1702) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1703) spin_unlock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1704) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1705) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1706)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1707) static loff_t configfs_dir_lseek(struct file *file, loff_t offset, int whence)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1708) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1709) struct dentry * dentry = file->f_path.dentry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1710)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1711) switch (whence) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1712) case 1:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1713) offset += file->f_pos;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1714) fallthrough;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1715) case 0:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1716) if (offset >= 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1717) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1718) fallthrough;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1719) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1720) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1721) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1722) if (offset != file->f_pos) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1723) file->f_pos = offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1724) if (file->f_pos >= 2) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1725) struct configfs_dirent *sd = dentry->d_fsdata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1726) struct configfs_dirent *cursor = file->private_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1727) struct list_head *p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1728) loff_t n = file->f_pos - 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1729)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1730) spin_lock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1731) list_del(&cursor->s_sibling);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1732) p = sd->s_children.next;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1733) while (n && p != &sd->s_children) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1734) struct configfs_dirent *next;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1735) next = list_entry(p, struct configfs_dirent,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1736) s_sibling);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1737) if (next->s_element)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1738) n--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1739) p = p->next;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1740) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1741) list_add_tail(&cursor->s_sibling, p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1742) spin_unlock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1743) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1744) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1745) return offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1746) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1747)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1748) const struct file_operations configfs_dir_operations = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1749) .open = configfs_dir_open,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1750) .release = configfs_dir_close,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1751) .llseek = configfs_dir_lseek,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1752) .read = generic_read_dir,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1753) .iterate_shared = configfs_readdir,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1754) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1755)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1756) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1757) * configfs_register_group - creates a parent-child relation between two groups
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1758) * @parent_group: parent group
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1759) * @group: child group
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1760) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1761) * link groups, creates dentry for the child and attaches it to the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1762) * parent dentry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1763) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1764) * Return: 0 on success, negative errno code on error
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1765) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1766) int configfs_register_group(struct config_group *parent_group,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1767) struct config_group *group)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1768) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1769) struct configfs_subsystem *subsys = parent_group->cg_subsys;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1770) struct dentry *parent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1771) struct configfs_fragment *frag;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1772) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1773)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1774) frag = new_fragment();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1775) if (!frag)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1776) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1777)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1778) mutex_lock(&subsys->su_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1779) link_group(parent_group, group);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1780) mutex_unlock(&subsys->su_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1781)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1782) parent = parent_group->cg_item.ci_dentry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1783)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1784) inode_lock_nested(d_inode(parent), I_MUTEX_PARENT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1785) ret = create_default_group(parent_group, group, frag);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1786) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1787) goto err_out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1788)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1789) spin_lock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1790) configfs_dir_set_ready(group->cg_item.ci_dentry->d_fsdata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1791) spin_unlock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1792) inode_unlock(d_inode(parent));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1793) put_fragment(frag);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1794) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1795) err_out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1796) inode_unlock(d_inode(parent));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1797) mutex_lock(&subsys->su_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1798) unlink_group(group);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1799) mutex_unlock(&subsys->su_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1800) put_fragment(frag);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1801) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1802) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1803) EXPORT_SYMBOL(configfs_register_group);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1804)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1805) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1806) * configfs_unregister_group() - unregisters a child group from its parent
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1807) * @group: parent group to be unregistered
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1808) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1809) * Undoes configfs_register_group()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1810) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1811) void configfs_unregister_group(struct config_group *group)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1812) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1813) struct configfs_subsystem *subsys = group->cg_subsys;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1814) struct dentry *dentry = group->cg_item.ci_dentry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1815) struct dentry *parent = group->cg_item.ci_parent->ci_dentry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1816) struct configfs_dirent *sd = dentry->d_fsdata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1817) struct configfs_fragment *frag = sd->s_frag;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1818)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1819) down_write(&frag->frag_sem);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1820) frag->frag_dead = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1821) up_write(&frag->frag_sem);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1822)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1823) inode_lock_nested(d_inode(parent), I_MUTEX_PARENT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1824) spin_lock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1825) configfs_detach_prep(dentry, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1826) spin_unlock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1827)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1828) configfs_detach_group(&group->cg_item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1829) d_inode(dentry)->i_flags |= S_DEAD;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1830) dont_mount(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1831) d_drop(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1832) fsnotify_rmdir(d_inode(parent), dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1833) inode_unlock(d_inode(parent));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1834)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1835) dput(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1836)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1837) mutex_lock(&subsys->su_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1838) unlink_group(group);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1839) mutex_unlock(&subsys->su_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1840) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1841) EXPORT_SYMBOL(configfs_unregister_group);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1842)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1843) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1844) * configfs_register_default_group() - allocates and registers a child group
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1845) * @parent_group: parent group
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1846) * @name: child group name
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1847) * @item_type: child item type description
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1848) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1849) * boilerplate to allocate and register a child group with its parent. We need
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1850) * kzalloc'ed memory because child's default_group is initially empty.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1851) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1852) * Return: allocated config group or ERR_PTR() on error
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1853) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1854) struct config_group *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1855) configfs_register_default_group(struct config_group *parent_group,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1856) const char *name,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1857) const struct config_item_type *item_type)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1858) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1859) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1860) struct config_group *group;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1861)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1862) group = kzalloc(sizeof(*group), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1863) if (!group)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1864) return ERR_PTR(-ENOMEM);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1865) config_group_init_type_name(group, name, item_type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1866)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1867) ret = configfs_register_group(parent_group, group);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1868) if (ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1869) kfree(group);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1870) return ERR_PTR(ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1871) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1872) return group;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1873) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1874) EXPORT_SYMBOL(configfs_register_default_group);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1875)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1876) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1877) * configfs_unregister_default_group() - unregisters and frees a child group
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1878) * @group: the group to act on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1879) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1880) void configfs_unregister_default_group(struct config_group *group)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1881) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1882) configfs_unregister_group(group);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1883) kfree(group);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1884) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1885) EXPORT_SYMBOL(configfs_unregister_default_group);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1886)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1887) int configfs_register_subsystem(struct configfs_subsystem *subsys)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1888) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1889) int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1890) struct config_group *group = &subsys->su_group;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1891) struct dentry *dentry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1892) struct dentry *root;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1893) struct configfs_dirent *sd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1894) struct configfs_fragment *frag;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1895)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1896) frag = new_fragment();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1897) if (!frag)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1898) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1899)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1900) root = configfs_pin_fs();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1901) if (IS_ERR(root)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1902) put_fragment(frag);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1903) return PTR_ERR(root);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1904) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1905)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1906) if (!group->cg_item.ci_name)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1907) group->cg_item.ci_name = group->cg_item.ci_namebuf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1908)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1909) sd = root->d_fsdata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1910) mutex_lock(&configfs_subsystem_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1911) link_group(to_config_group(sd->s_element), group);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1912) mutex_unlock(&configfs_subsystem_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1913)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1914) inode_lock_nested(d_inode(root), I_MUTEX_PARENT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1915)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1916) err = -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1917) dentry = d_alloc_name(root, group->cg_item.ci_name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1918) if (dentry) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1919) d_add(dentry, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1920)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1921) err = configfs_attach_group(sd->s_element, &group->cg_item,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1922) dentry, frag);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1923) if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1924) BUG_ON(d_inode(dentry));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1925) d_drop(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1926) dput(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1927) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1928) spin_lock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1929) configfs_dir_set_ready(dentry->d_fsdata);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1930) spin_unlock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1931) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1932) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1933)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1934) inode_unlock(d_inode(root));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1935)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1936) if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1937) mutex_lock(&configfs_subsystem_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1938) unlink_group(group);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1939) mutex_unlock(&configfs_subsystem_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1940) configfs_release_fs();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1941) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1942) put_fragment(frag);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1943)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1944) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1945) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1946)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1947) void configfs_unregister_subsystem(struct configfs_subsystem *subsys)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1948) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1949) struct config_group *group = &subsys->su_group;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1950) struct dentry *dentry = group->cg_item.ci_dentry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1951) struct dentry *root = dentry->d_sb->s_root;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1952) struct configfs_dirent *sd = dentry->d_fsdata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1953) struct configfs_fragment *frag = sd->s_frag;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1954)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1955) if (dentry->d_parent != root) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1956) pr_err("Tried to unregister non-subsystem!\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1957) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1958) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1959)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1960) down_write(&frag->frag_sem);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1961) frag->frag_dead = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1962) up_write(&frag->frag_sem);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1963)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1964) inode_lock_nested(d_inode(root),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1965) I_MUTEX_PARENT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1966) inode_lock_nested(d_inode(dentry), I_MUTEX_CHILD);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1967) mutex_lock(&configfs_symlink_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1968) spin_lock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1969) if (configfs_detach_prep(dentry, NULL)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1970) pr_err("Tried to unregister non-empty subsystem!\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1971) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1972) spin_unlock(&configfs_dirent_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1973) mutex_unlock(&configfs_symlink_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1974) configfs_detach_group(&group->cg_item);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1975) d_inode(dentry)->i_flags |= S_DEAD;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1976) dont_mount(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1977) inode_unlock(d_inode(dentry));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1978)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1979) d_drop(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1980) fsnotify_rmdir(d_inode(root), dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1981)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1982) inode_unlock(d_inode(root));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1983)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1984) dput(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1985)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1986) mutex_lock(&configfs_subsystem_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1987) unlink_group(group);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1988) mutex_unlock(&configfs_subsystem_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1989) configfs_release_fs();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1990) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1991)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1992) EXPORT_SYMBOL(configfs_register_subsystem);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1993) EXPORT_SYMBOL(configfs_unregister_subsystem);
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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