Update Linux to v5.4.2
Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/fs/configfs/Kconfig b/fs/configfs/Kconfig
index 9febcde..272b644 100644
--- a/fs/configfs/Kconfig
+++ b/fs/configfs/Kconfig
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
config CONFIGFS_FS
tristate "Userspace-driven configuration filesystem"
select SYSFS
diff --git a/fs/configfs/Makefile b/fs/configfs/Makefile
index 00ffb27..0200498 100644
--- a/fs/configfs/Makefile
+++ b/fs/configfs/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
#
# Makefile for the configfs virtual filesystem
#
diff --git a/fs/configfs/configfs_internal.h b/fs/configfs/configfs_internal.h
index ccc31fa..22dce2d 100644
--- a/fs/configfs/configfs_internal.h
+++ b/fs/configfs/configfs_internal.h
@@ -1,23 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
/* -*- mode: c; c-basic-offset:8; -*-
* vim: noexpandtab sw=8 ts=8 sts=0:
*
* configfs_internal.h - Internal stuff for configfs
*
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public
- * License along with this program; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 021110-1307, USA.
- *
* Based on sysfs:
* sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
*
@@ -34,12 +20,21 @@
#include <linux/list.h>
#include <linux/spinlock.h>
+struct configfs_fragment {
+ atomic_t frag_count;
+ struct rw_semaphore frag_sem;
+ bool frag_dead;
+};
+
+void put_fragment(struct configfs_fragment *);
+struct configfs_fragment *get_fragment(struct configfs_fragment *);
+
struct configfs_dirent {
atomic_t s_count;
int s_dependent_count;
struct list_head s_sibling;
struct list_head s_children;
- struct list_head s_links;
+ int s_links;
void * s_element;
int s_type;
umode_t s_mode;
@@ -48,6 +43,7 @@
#ifdef CONFIG_LOCKDEP
int s_depth;
#endif
+ struct configfs_fragment *s_frag;
};
#define CONFIGFS_ROOT 0x0001
@@ -70,13 +66,13 @@
extern int configfs_is_root(struct config_item *item);
extern struct inode * configfs_new_inode(umode_t mode, struct configfs_dirent *, struct super_block *);
-extern int configfs_create(struct dentry *, umode_t mode, void (*init)(struct inode *));
+extern struct inode *configfs_create(struct dentry *, umode_t mode);
extern int configfs_create_file(struct config_item *, const struct configfs_attribute *);
extern int configfs_create_bin_file(struct config_item *,
const struct configfs_bin_attribute *);
-extern int configfs_make_dirent(struct configfs_dirent *,
- struct dentry *, void *, umode_t, int);
+extern int configfs_make_dirent(struct configfs_dirent *, struct dentry *,
+ void *, umode_t, int, struct configfs_fragment *);
extern int configfs_dirent_is_ready(struct configfs_dirent *);
extern void configfs_hash_and_remove(struct dentry * dir, const char * name);
@@ -88,7 +84,6 @@
extern struct dentry *configfs_pin_fs(void);
extern void configfs_release_fs(void);
-extern struct rw_semaphore configfs_rename_sem;
extern const struct file_operations configfs_dir_operations;
extern const struct file_operations configfs_file_operations;
extern const struct file_operations configfs_bin_file_operations;
@@ -101,14 +96,8 @@
const char *symname);
extern int configfs_unlink(struct inode *dir, struct dentry *dentry);
-struct configfs_symlink {
- struct list_head sl_list;
- struct config_item *sl_target;
-};
-
-extern int configfs_create_link(struct configfs_symlink *sl,
- struct dentry *parent,
- struct dentry *dentry);
+int configfs_create_link(struct configfs_dirent *target, struct dentry *parent,
+ struct dentry *dentry, char *body);
static inline struct config_item * to_item(struct dentry * dentry)
{
@@ -136,11 +125,7 @@
spin_lock(&dentry->d_lock);
if (!d_unhashed(dentry)) {
struct configfs_dirent * sd = dentry->d_fsdata;
- if (sd->s_type & CONFIGFS_ITEM_LINK) {
- struct configfs_symlink * sl = sd->s_element;
- item = config_item_get(sl->sl_target);
- } else
- item = config_item_get(sd->s_element);
+ item = config_item_get(sd->s_element);
}
spin_unlock(&dentry->d_lock);
@@ -151,6 +136,7 @@
{
if (!(sd->s_type & CONFIGFS_ROOT)) {
kfree(sd->s_iattr);
+ put_fragment(sd->s_frag);
kmem_cache_free(configfs_dir_cachep, sd);
}
}
diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c
index 39843fa..cf7b7e1 100644
--- a/fs/configfs/dir.c
+++ b/fs/configfs/dir.c
@@ -1,23 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/* -*- mode: c; c-basic-offset: 8; -*-
* vim: noexpandtab sw=8 ts=8 sts=0:
*
* dir.c - Operations for configfs directories.
*
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public
- * License along with this program; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 021110-1307, USA.
- *
* Based on sysfs:
* sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
*
@@ -27,6 +13,7 @@
#undef DEBUG
#include <linux/fs.h>
+#include <linux/fsnotify.h>
#include <linux/mount.h>
#include <linux/module.h>
#include <linux/slab.h>
@@ -35,7 +22,6 @@
#include <linux/configfs.h>
#include "configfs_internal.h"
-DECLARE_RWSEM(configfs_rename_sem);
/*
* Protects mutations of configfs_dirent linkage together with proper i_mutex
* Also protects mutations of symlinks linkage to target configfs_dirent
@@ -58,15 +44,13 @@
if (sd) {
/* Coordinate with configfs_readdir */
spin_lock(&configfs_dirent_lock);
- /* Coordinate with configfs_attach_attr where will increase
- * sd->s_count and update sd->s_dentry to new allocated one.
- * Only set sd->dentry to null when this dentry is the only
- * sd owner.
- * If not do so, configfs_d_iput may run just after
- * configfs_attach_attr and set sd->s_dentry to null
- * even it's still in use.
+ /*
+ * Set sd->s_dentry to null only when this dentry is the one
+ * that is going to be killed. Otherwise configfs_d_iput may
+ * run just after configfs_attach_attr and set sd->s_dentry to
+ * NULL even it's still in use.
*/
- if (atomic_read(&sd->s_count) <= 2)
+ if (sd->s_dentry == dentry)
sd->s_dentry = NULL;
spin_unlock(&configfs_dirent_lock);
@@ -166,11 +150,38 @@
#endif /* CONFIG_LOCKDEP */
+static struct configfs_fragment *new_fragment(void)
+{
+ struct configfs_fragment *p;
+
+ p = kmalloc(sizeof(struct configfs_fragment), GFP_KERNEL);
+ if (p) {
+ atomic_set(&p->frag_count, 1);
+ init_rwsem(&p->frag_sem);
+ p->frag_dead = false;
+ }
+ return p;
+}
+
+void put_fragment(struct configfs_fragment *frag)
+{
+ if (frag && atomic_dec_and_test(&frag->frag_count))
+ kfree(frag);
+}
+
+struct configfs_fragment *get_fragment(struct configfs_fragment *frag)
+{
+ if (likely(frag))
+ atomic_inc(&frag->frag_count);
+ return frag;
+}
+
/*
* Allocates a new configfs_dirent and links it to the parent configfs_dirent
*/
static struct configfs_dirent *configfs_new_dirent(struct configfs_dirent *parent_sd,
- void *element, int type)
+ void *element, int type,
+ struct configfs_fragment *frag)
{
struct configfs_dirent * sd;
@@ -179,7 +190,6 @@
return ERR_PTR(-ENOMEM);
atomic_set(&sd->s_count, 1);
- INIT_LIST_HEAD(&sd->s_links);
INIT_LIST_HEAD(&sd->s_children);
sd->s_element = element;
sd->s_type = type;
@@ -190,6 +200,7 @@
kmem_cache_free(configfs_dir_cachep, sd);
return ERR_PTR(-ENOENT);
}
+ sd->s_frag = get_fragment(frag);
list_add(&sd->s_sibling, &parent_sd->s_children);
spin_unlock(&configfs_dirent_lock);
@@ -224,11 +235,11 @@
int configfs_make_dirent(struct configfs_dirent * parent_sd,
struct dentry * dentry, void * element,
- umode_t mode, int type)
+ umode_t mode, int type, struct configfs_fragment *frag)
{
struct configfs_dirent * sd;
- sd = configfs_new_dirent(parent_sd, element, type);
+ sd = configfs_new_dirent(parent_sd, element, type, frag);
if (IS_ERR(sd))
return PTR_ERR(sd);
@@ -240,30 +251,16 @@
return 0;
}
-static void init_dir(struct inode * inode)
+static void configfs_remove_dirent(struct dentry *dentry)
{
- inode->i_op = &configfs_dir_inode_operations;
- inode->i_fop = &configfs_dir_operations;
+ struct configfs_dirent *sd = dentry->d_fsdata;
- /* directory inodes start off with i_nlink == 2 (for "." entry) */
- inc_nlink(inode);
-}
-
-static void configfs_init_file(struct inode * inode)
-{
- inode->i_size = PAGE_SIZE;
- inode->i_fop = &configfs_file_operations;
-}
-
-static void configfs_init_bin_file(struct inode *inode)
-{
- inode->i_size = 0;
- inode->i_fop = &configfs_bin_file_operations;
-}
-
-static void init_symlink(struct inode * inode)
-{
- inode->i_op = &configfs_symlink_inode_operations;
+ if (!sd)
+ return;
+ spin_lock(&configfs_dirent_lock);
+ list_del_init(&sd->s_sibling);
+ spin_unlock(&configfs_dirent_lock);
+ configfs_put(sd);
}
/**
@@ -275,11 +272,13 @@
* until it is validated by configfs_dir_set_ready()
*/
-static int configfs_create_dir(struct config_item *item, struct dentry *dentry)
+static int configfs_create_dir(struct config_item *item, struct dentry *dentry,
+ struct configfs_fragment *frag)
{
int error;
umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO;
struct dentry *p = dentry->d_parent;
+ struct inode *inode;
BUG_ON(!item);
@@ -288,25 +287,30 @@
return error;
error = configfs_make_dirent(p->d_fsdata, dentry, item, mode,
- CONFIGFS_DIR | CONFIGFS_USET_CREATING);
+ CONFIGFS_DIR | CONFIGFS_USET_CREATING,
+ frag);
if (unlikely(error))
return error;
configfs_set_dir_dirent_depth(p->d_fsdata, dentry->d_fsdata);
- error = configfs_create(dentry, mode, init_dir);
- if (!error) {
- inc_nlink(d_inode(p));
- item->ci_dentry = dentry;
- } else {
- struct configfs_dirent *sd = dentry->d_fsdata;
- if (sd) {
- spin_lock(&configfs_dirent_lock);
- list_del_init(&sd->s_sibling);
- spin_unlock(&configfs_dirent_lock);
- configfs_put(sd);
- }
- }
- return error;
+ inode = configfs_create(dentry, mode);
+ if (IS_ERR(inode))
+ goto out_remove;
+
+ inode->i_op = &configfs_dir_inode_operations;
+ inode->i_fop = &configfs_dir_operations;
+ /* directory inodes start off with i_nlink == 2 (for "." entry) */
+ inc_nlink(inode);
+ d_instantiate(dentry, inode);
+ /* already hashed */
+ dget(dentry); /* pin directory dentries in core */
+ inc_nlink(d_inode(p));
+ item->ci_dentry = dentry;
+ return 0;
+
+out_remove:
+ configfs_remove_dirent(dentry);
+ return PTR_ERR(inode);
}
/*
@@ -347,40 +351,40 @@
return ret;
}
-int configfs_create_link(struct configfs_symlink *sl,
- struct dentry *parent,
- struct dentry *dentry)
+int configfs_create_link(struct configfs_dirent *target, struct dentry *parent,
+ struct dentry *dentry, char *body)
{
int err = 0;
umode_t mode = S_IFLNK | S_IRWXUGO;
+ struct configfs_dirent *p = parent->d_fsdata;
+ struct inode *inode;
- err = configfs_make_dirent(parent->d_fsdata, dentry, sl, mode,
- CONFIGFS_ITEM_LINK);
- if (!err) {
- err = configfs_create(dentry, mode, init_symlink);
- if (err) {
- struct configfs_dirent *sd = dentry->d_fsdata;
- if (sd) {
- spin_lock(&configfs_dirent_lock);
- list_del_init(&sd->s_sibling);
- spin_unlock(&configfs_dirent_lock);
- configfs_put(sd);
- }
- }
- }
- return err;
+ err = configfs_make_dirent(p, dentry, target, mode, CONFIGFS_ITEM_LINK,
+ p->s_frag);
+ if (err)
+ return err;
+
+ inode = configfs_create(dentry, mode);
+ if (IS_ERR(inode))
+ goto out_remove;
+
+ inode->i_link = body;
+ inode->i_op = &configfs_symlink_inode_operations;
+ d_instantiate(dentry, inode);
+ dget(dentry); /* pin link dentries in core */
+ return 0;
+
+out_remove:
+ configfs_remove_dirent(dentry);
+ return PTR_ERR(inode);
}
static void remove_dir(struct dentry * d)
{
struct dentry * parent = dget(d->d_parent);
- struct configfs_dirent * sd;
- sd = d->d_fsdata;
- spin_lock(&configfs_dirent_lock);
- list_del_init(&sd->s_sibling);
- spin_unlock(&configfs_dirent_lock);
- configfs_put(sd);
+ configfs_remove_dirent(d);
+
if (d_really_is_positive(d))
simple_rmdir(d_inode(parent),d);
@@ -421,20 +425,27 @@
static int configfs_attach_attr(struct configfs_dirent * sd, struct dentry * dentry)
{
struct configfs_attribute * attr = sd->s_element;
- int error;
+ struct inode *inode;
spin_lock(&configfs_dirent_lock);
dentry->d_fsdata = configfs_get(sd);
sd->s_dentry = dentry;
spin_unlock(&configfs_dirent_lock);
- error = configfs_create(dentry, (attr->ca_mode & S_IALLUGO) | S_IFREG,
- (sd->s_type & CONFIGFS_ITEM_BIN_ATTR) ?
- configfs_init_bin_file :
- configfs_init_file);
- if (error)
+ inode = configfs_create(dentry, (attr->ca_mode & S_IALLUGO) | S_IFREG);
+ if (IS_ERR(inode)) {
configfs_put(sd);
- return error;
+ return PTR_ERR(inode);
+ }
+ if (sd->s_type & CONFIGFS_ITEM_BIN_ATTR) {
+ inode->i_size = 0;
+ inode->i_fop = &configfs_bin_file_operations;
+ } else {
+ inode->i_size = PAGE_SIZE;
+ inode->i_fop = &configfs_file_operations;
+ }
+ d_add(dentry, inode);
+ return 0;
}
static struct dentry * configfs_lookup(struct inode *dir,
@@ -504,7 +515,7 @@
parent_sd->s_type |= CONFIGFS_USET_DROPPING;
ret = -EBUSY;
- if (!list_empty(&parent_sd->s_links))
+ if (parent_sd->s_links)
goto out;
ret = 0;
@@ -614,7 +625,8 @@
static int configfs_attach_group(struct config_item *parent_item,
struct config_item *item,
- struct dentry *dentry);
+ struct dentry *dentry,
+ struct configfs_fragment *frag);
static void configfs_detach_group(struct config_item *item);
static void detach_groups(struct config_group *group)
@@ -662,7 +674,8 @@
* try using vfs_mkdir. Just a thought.
*/
static int create_default_group(struct config_group *parent_group,
- struct config_group *group)
+ struct config_group *group,
+ struct configfs_fragment *frag)
{
int ret;
struct configfs_dirent *sd;
@@ -678,7 +691,7 @@
d_add(child, NULL);
ret = configfs_attach_group(&parent_group->cg_item,
- &group->cg_item, child);
+ &group->cg_item, child, frag);
if (!ret) {
sd = child->d_fsdata;
sd->s_type |= CONFIGFS_USET_DEFAULT;
@@ -692,13 +705,14 @@
return ret;
}
-static int populate_groups(struct config_group *group)
+static int populate_groups(struct config_group *group,
+ struct configfs_fragment *frag)
{
struct config_group *new_group;
int ret = 0;
list_for_each_entry(new_group, &group->default_groups, group_entry) {
- ret = create_default_group(group, new_group);
+ ret = create_default_group(group, new_group, frag);
if (ret) {
detach_groups(group);
break;
@@ -812,11 +826,12 @@
*/
static int configfs_attach_item(struct config_item *parent_item,
struct config_item *item,
- struct dentry *dentry)
+ struct dentry *dentry,
+ struct configfs_fragment *frag)
{
int ret;
- ret = configfs_create_dir(item, dentry);
+ ret = configfs_create_dir(item, dentry, frag);
if (!ret) {
ret = populate_attrs(item);
if (ret) {
@@ -846,12 +861,13 @@
static int configfs_attach_group(struct config_item *parent_item,
struct config_item *item,
- struct dentry *dentry)
+ struct dentry *dentry,
+ struct configfs_fragment *frag)
{
int ret;
struct configfs_dirent *sd;
- ret = configfs_attach_item(parent_item, item, dentry);
+ ret = configfs_attach_item(parent_item, item, dentry, frag);
if (!ret) {
sd = dentry->d_fsdata;
sd->s_type |= CONFIGFS_USET_DIR;
@@ -867,7 +883,7 @@
*/
inode_lock_nested(d_inode(dentry), I_MUTEX_CHILD);
configfs_adjust_dir_dirent_depth_before_populate(sd);
- ret = populate_groups(to_config_group(item));
+ ret = populate_groups(to_config_group(item), frag);
if (ret) {
configfs_detach_item(item);
d_inode(dentry)->i_flags |= S_DEAD;
@@ -1262,6 +1278,7 @@
struct configfs_dirent *sd;
const struct config_item_type *type;
struct module *subsys_owner = NULL, *new_item_owner = NULL;
+ struct configfs_fragment *frag;
char *name;
sd = dentry->d_parent->d_fsdata;
@@ -1280,6 +1297,12 @@
goto out;
}
+ frag = new_fragment();
+ if (!frag) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
/* Get a working ref for the duration of this function */
parent_item = configfs_get_config_item(dentry->d_parent);
type = parent_item->ci_type;
@@ -1382,9 +1405,9 @@
spin_unlock(&configfs_dirent_lock);
if (group)
- ret = configfs_attach_group(parent_item, item, dentry);
+ ret = configfs_attach_group(parent_item, item, dentry, frag);
else
- ret = configfs_attach_item(parent_item, item, dentry);
+ ret = configfs_attach_item(parent_item, item, dentry, frag);
spin_lock(&configfs_dirent_lock);
sd->s_type &= ~CONFIGFS_USET_IN_MKDIR;
@@ -1421,6 +1444,7 @@
* reference.
*/
config_item_put(parent_item);
+ put_fragment(frag);
out:
return ret;
@@ -1432,6 +1456,7 @@
struct config_item *item;
struct configfs_subsystem *subsys;
struct configfs_dirent *sd;
+ struct configfs_fragment *frag;
struct module *subsys_owner = NULL, *dead_item_owner = NULL;
int ret;
@@ -1489,6 +1514,16 @@
}
} while (ret == -EAGAIN);
+ frag = sd->s_frag;
+ if (down_write_killable(&frag->frag_sem)) {
+ spin_lock(&configfs_dirent_lock);
+ configfs_detach_rollback(dentry);
+ spin_unlock(&configfs_dirent_lock);
+ return -EINTR;
+ }
+ frag->frag_dead = true;
+ up_write(&frag->frag_sem);
+
/* Get a working ref for the duration of this function */
item = configfs_get_config_item(dentry);
@@ -1538,44 +1573,6 @@
.setattr = configfs_setattr,
};
-#if 0
-int configfs_rename_dir(struct config_item * item, const char *new_name)
-{
- int error = 0;
- struct dentry * new_dentry, * parent;
-
- if (!strcmp(config_item_name(item), new_name))
- return -EINVAL;
-
- if (!item->parent)
- return -EINVAL;
-
- down_write(&configfs_rename_sem);
- parent = item->parent->dentry;
-
- inode_lock(d_inode(parent));
-
- new_dentry = lookup_one_len(new_name, parent, strlen(new_name));
- if (!IS_ERR(new_dentry)) {
- if (d_really_is_negative(new_dentry)) {
- error = config_item_set_name(item, "%s", new_name);
- if (!error) {
- d_add(new_dentry, NULL);
- d_move(item->dentry, new_dentry);
- }
- else
- d_delete(new_dentry);
- } else
- error = -EEXIST;
- dput(new_dentry);
- }
- inode_unlock(d_inode(parent));
- up_write(&configfs_rename_sem);
-
- return error;
-}
-#endif
-
static int configfs_dir_open(struct inode *inode, struct file *file)
{
struct dentry * dentry = file->f_path.dentry;
@@ -1589,7 +1586,7 @@
*/
err = -ENOENT;
if (configfs_dirent_is_ready(parent_sd)) {
- file->private_data = configfs_new_dirent(parent_sd, NULL, 0);
+ file->private_data = configfs_new_dirent(parent_sd, NULL, 0, NULL);
if (IS_ERR(file->private_data))
err = PTR_ERR(file->private_data);
else
@@ -1690,9 +1687,11 @@
switch (whence) {
case 1:
offset += file->f_pos;
+ /* fall through */
case 0:
if (offset >= 0)
break;
+ /* fall through */
default:
return -EINVAL;
}
@@ -1745,8 +1744,13 @@
{
struct configfs_subsystem *subsys = parent_group->cg_subsys;
struct dentry *parent;
+ struct configfs_fragment *frag;
int ret;
+ frag = new_fragment();
+ if (!frag)
+ return -ENOMEM;
+
mutex_lock(&subsys->su_mutex);
link_group(parent_group, group);
mutex_unlock(&subsys->su_mutex);
@@ -1754,13 +1758,22 @@
parent = parent_group->cg_item.ci_dentry;
inode_lock_nested(d_inode(parent), I_MUTEX_PARENT);
- ret = create_default_group(parent_group, group);
- if (!ret) {
- spin_lock(&configfs_dirent_lock);
- configfs_dir_set_ready(group->cg_item.ci_dentry->d_fsdata);
- spin_unlock(&configfs_dirent_lock);
- }
+ ret = create_default_group(parent_group, group, frag);
+ if (ret)
+ goto err_out;
+
+ spin_lock(&configfs_dirent_lock);
+ configfs_dir_set_ready(group->cg_item.ci_dentry->d_fsdata);
+ spin_unlock(&configfs_dirent_lock);
inode_unlock(d_inode(parent));
+ put_fragment(frag);
+ return 0;
+err_out:
+ inode_unlock(d_inode(parent));
+ mutex_lock(&subsys->su_mutex);
+ unlink_group(group);
+ mutex_unlock(&subsys->su_mutex);
+ put_fragment(frag);
return ret;
}
EXPORT_SYMBOL(configfs_register_group);
@@ -1776,16 +1789,12 @@
struct configfs_subsystem *subsys = group->cg_subsys;
struct dentry *dentry = group->cg_item.ci_dentry;
struct dentry *parent = group->cg_item.ci_parent->ci_dentry;
+ struct configfs_dirent *sd = dentry->d_fsdata;
+ struct configfs_fragment *frag = sd->s_frag;
- mutex_lock(&subsys->su_mutex);
- if (!group->cg_item.ci_parent->ci_group) {
- /*
- * The parent has already been unlinked and detached
- * due to a rmdir.
- */
- goto unlink_group;
- }
- mutex_unlock(&subsys->su_mutex);
+ down_write(&frag->frag_sem);
+ frag->frag_dead = true;
+ up_write(&frag->frag_sem);
inode_lock_nested(d_inode(parent), I_MUTEX_PARENT);
spin_lock(&configfs_dirent_lock);
@@ -1795,13 +1804,13 @@
configfs_detach_group(&group->cg_item);
d_inode(dentry)->i_flags |= S_DEAD;
dont_mount(dentry);
+ fsnotify_rmdir(d_inode(parent), dentry);
d_delete(dentry);
inode_unlock(d_inode(parent));
dput(dentry);
mutex_lock(&subsys->su_mutex);
-unlink_group:
unlink_group(group);
mutex_unlock(&subsys->su_mutex);
}
@@ -1858,10 +1867,17 @@
struct dentry *dentry;
struct dentry *root;
struct configfs_dirent *sd;
+ struct configfs_fragment *frag;
+
+ frag = new_fragment();
+ if (!frag)
+ return -ENOMEM;
root = configfs_pin_fs();
- if (IS_ERR(root))
+ if (IS_ERR(root)) {
+ put_fragment(frag);
return PTR_ERR(root);
+ }
if (!group->cg_item.ci_name)
group->cg_item.ci_name = group->cg_item.ci_namebuf;
@@ -1877,7 +1893,7 @@
d_add(dentry, NULL);
err = configfs_attach_group(sd->s_element, &group->cg_item,
- dentry);
+ dentry, frag);
if (err) {
BUG_ON(d_inode(dentry));
d_drop(dentry);
@@ -1895,6 +1911,7 @@
unlink_group(group);
configfs_release_fs();
}
+ put_fragment(frag);
return err;
}
@@ -1904,12 +1921,18 @@
struct config_group *group = &subsys->su_group;
struct dentry *dentry = group->cg_item.ci_dentry;
struct dentry *root = dentry->d_sb->s_root;
+ struct configfs_dirent *sd = dentry->d_fsdata;
+ struct configfs_fragment *frag = sd->s_frag;
if (dentry->d_parent != root) {
pr_err("Tried to unregister non-subsystem!\n");
return;
}
+ down_write(&frag->frag_sem);
+ frag->frag_dead = true;
+ up_write(&frag->frag_sem);
+
inode_lock_nested(d_inode(root),
I_MUTEX_PARENT);
inode_lock_nested(d_inode(dentry), I_MUTEX_CHILD);
@@ -1923,6 +1946,7 @@
configfs_detach_group(&group->cg_item);
d_inode(dentry)->i_flags |= S_DEAD;
dont_mount(dentry);
+ fsnotify_rmdir(d_inode(root), dentry);
inode_unlock(d_inode(dentry));
d_delete(dentry);
diff --git a/fs/configfs/file.c b/fs/configfs/file.c
index 62580db..fb65b70 100644
--- a/fs/configfs/file.c
+++ b/fs/configfs/file.c
@@ -1,23 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/* -*- mode: c; c-basic-offset: 8; -*-
* vim: noexpandtab sw=8 ts=8 sts=0:
*
* file.c - operations for regular (text) files.
*
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public
- * License along with this program; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 021110-1307, USA.
- *
* Based on sysfs:
* sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
*
@@ -53,40 +39,44 @@
bool write_in_progress;
char *bin_buffer;
int bin_buffer_size;
+ int cb_max_size;
+ struct config_item *item;
+ struct module *owner;
+ union {
+ struct configfs_attribute *attr;
+ struct configfs_bin_attribute *bin_attr;
+ };
};
-
-/**
- * fill_read_buffer - allocate and fill buffer from item.
- * @dentry: dentry pointer.
- * @buffer: data buffer for file.
- *
- * Allocate @buffer->page, if it hasn't been already, then call the
- * config_item's show() method to fill the buffer with this attribute's
- * data.
- * This is called only once, on the file's first read.
- */
-static int fill_read_buffer(struct dentry * dentry, struct configfs_buffer * buffer)
+static inline struct configfs_fragment *to_frag(struct file *file)
{
- struct configfs_attribute * attr = to_attr(dentry);
- struct config_item * item = to_item(dentry->d_parent);
- int ret = 0;
- ssize_t count;
+ struct configfs_dirent *sd = file->f_path.dentry->d_fsdata;
+
+ return sd->s_frag;
+}
+
+static int fill_read_buffer(struct file *file, struct configfs_buffer *buffer)
+{
+ struct configfs_fragment *frag = to_frag(file);
+ ssize_t count = -ENOENT;
if (!buffer->page)
buffer->page = (char *) get_zeroed_page(GFP_KERNEL);
if (!buffer->page)
return -ENOMEM;
- count = attr->show(item, buffer->page);
+ down_read(&frag->frag_sem);
+ if (!frag->frag_dead)
+ count = buffer->attr->show(buffer->item, buffer->page);
+ up_read(&frag->frag_sem);
- BUG_ON(count > (ssize_t)SIMPLE_ATTR_SIZE);
- if (count >= 0) {
- buffer->needs_read_fill = 0;
- buffer->count = count;
- } else
- ret = count;
- return ret;
+ if (count < 0)
+ return count;
+ if (WARN_ON_ONCE(count > (ssize_t)SIMPLE_ATTR_SIZE))
+ return -EIO;
+ buffer->needs_read_fill = 0;
+ buffer->count = count;
+ return 0;
}
/**
@@ -111,12 +101,13 @@
static ssize_t
configfs_read_file(struct file *file, char __user *buf, size_t count, loff_t *ppos)
{
- struct configfs_buffer * buffer = file->private_data;
+ struct configfs_buffer *buffer = file->private_data;
ssize_t retval = 0;
mutex_lock(&buffer->mutex);
if (buffer->needs_read_fill) {
- if ((retval = fill_read_buffer(file->f_path.dentry,buffer)))
+ retval = fill_read_buffer(file, buffer);
+ if (retval)
goto out;
}
pr_debug("%s: count = %zd, ppos = %lld, buf = %s\n",
@@ -152,10 +143,8 @@
configfs_read_bin_file(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
+ struct configfs_fragment *frag = to_frag(file);
struct configfs_buffer *buffer = file->private_data;
- struct dentry *dentry = file->f_path.dentry;
- struct config_item *item = to_item(dentry->d_parent);
- struct configfs_bin_attribute *bin_attr = to_bin_attr(dentry);
ssize_t retval = 0;
ssize_t len = min_t(size_t, count, PAGE_SIZE);
@@ -170,14 +159,19 @@
if (buffer->needs_read_fill) {
/* perform first read with buf == NULL to get extent */
- len = bin_attr->read(item, NULL, 0);
+ down_read(&frag->frag_sem);
+ if (!frag->frag_dead)
+ len = buffer->bin_attr->read(buffer->item, NULL, 0);
+ else
+ len = -ENOENT;
+ up_read(&frag->frag_sem);
if (len <= 0) {
retval = len;
goto out;
}
/* do not exceed the maximum value */
- if (bin_attr->cb_max_size && len > bin_attr->cb_max_size) {
+ if (buffer->cb_max_size && len > buffer->cb_max_size) {
retval = -EFBIG;
goto out;
}
@@ -190,7 +184,13 @@
buffer->bin_buffer_size = len;
/* perform second read to fill buffer */
- len = bin_attr->read(item, buffer->bin_buffer, len);
+ down_read(&frag->frag_sem);
+ if (!frag->frag_dead)
+ len = buffer->bin_attr->read(buffer->item,
+ buffer->bin_buffer, len);
+ else
+ len = -ENOENT;
+ up_read(&frag->frag_sem);
if (len < 0) {
retval = len;
vfree(buffer->bin_buffer);
@@ -240,25 +240,17 @@
return error ? -EFAULT : count;
}
-
-/**
- * flush_write_buffer - push buffer to config_item.
- * @dentry: dentry to the attribute
- * @buffer: data buffer for file.
- * @count: number of bytes
- *
- * Get the correct pointers for the config_item and the attribute we're
- * dealing with, then call the store() method for the attribute,
- * passing the buffer that we acquired in fill_write_buffer().
- */
-
static int
-flush_write_buffer(struct dentry * dentry, struct configfs_buffer * buffer, size_t count)
+flush_write_buffer(struct file *file, struct configfs_buffer *buffer, size_t count)
{
- struct configfs_attribute * attr = to_attr(dentry);
- struct config_item * item = to_item(dentry->d_parent);
+ struct configfs_fragment *frag = to_frag(file);
+ int res = -ENOENT;
- return attr->store(item, buffer->page, count);
+ down_read(&frag->frag_sem);
+ if (!frag->frag_dead)
+ res = buffer->attr->store(buffer->item, buffer->page, count);
+ up_read(&frag->frag_sem);
+ return res;
}
@@ -282,13 +274,13 @@
static ssize_t
configfs_write_file(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
{
- struct configfs_buffer * buffer = file->private_data;
+ struct configfs_buffer *buffer = file->private_data;
ssize_t len;
mutex_lock(&buffer->mutex);
len = fill_write_buffer(buffer, buf, count);
if (len > 0)
- len = flush_write_buffer(file->f_path.dentry, buffer, len);
+ len = flush_write_buffer(file, buffer, len);
if (len > 0)
*ppos += len;
mutex_unlock(&buffer->mutex);
@@ -313,8 +305,6 @@
size_t count, loff_t *ppos)
{
struct configfs_buffer *buffer = file->private_data;
- struct dentry *dentry = file->f_path.dentry;
- struct configfs_bin_attribute *bin_attr = to_bin_attr(dentry);
void *tbuf = NULL;
ssize_t len;
@@ -330,8 +320,8 @@
/* buffer grows? */
if (*ppos + count > buffer->bin_buffer_size) {
- if (bin_attr->cb_max_size &&
- *ppos + count > bin_attr->cb_max_size) {
+ if (buffer->cb_max_size &&
+ *ppos + count > buffer->cb_max_size) {
len = -EFBIG;
goto out;
}
@@ -363,31 +353,51 @@
return len;
}
-static int check_perm(struct inode * inode, struct file * file, int type)
+static int __configfs_open_file(struct inode *inode, struct file *file, int type)
{
- struct config_item *item = configfs_get_config_item(file->f_path.dentry->d_parent);
- struct configfs_attribute * attr = to_attr(file->f_path.dentry);
- struct configfs_bin_attribute *bin_attr = NULL;
- struct configfs_buffer * buffer;
- struct configfs_item_operations * ops = NULL;
- int error = 0;
+ struct dentry *dentry = file->f_path.dentry;
+ struct configfs_fragment *frag = to_frag(file);
+ struct configfs_attribute *attr;
+ struct configfs_buffer *buffer;
+ int error;
- if (!item || !attr)
- goto Einval;
+ error = -ENOMEM;
+ buffer = kzalloc(sizeof(struct configfs_buffer), GFP_KERNEL);
+ if (!buffer)
+ goto out;
- if (type & CONFIGFS_ITEM_BIN_ATTR)
- bin_attr = to_bin_attr(file->f_path.dentry);
+ error = -ENOENT;
+ down_read(&frag->frag_sem);
+ if (unlikely(frag->frag_dead))
+ goto out_free_buffer;
- /* Grab the module reference for this attribute if we have one */
- if (!try_module_get(attr->ca_owner)) {
- error = -ENODEV;
- goto Done;
+ error = -EINVAL;
+ buffer->item = to_item(dentry->d_parent);
+ if (!buffer->item)
+ goto out_free_buffer;
+
+ attr = to_attr(dentry);
+ if (!attr)
+ goto out_put_item;
+
+ if (type & CONFIGFS_ITEM_BIN_ATTR) {
+ buffer->bin_attr = to_bin_attr(dentry);
+ buffer->cb_max_size = buffer->bin_attr->cb_max_size;
+ } else {
+ buffer->attr = attr;
}
- if (item->ci_type)
- ops = item->ci_type->ct_item_ops;
- else
- goto Eaccess;
+ buffer->owner = attr->ca_owner;
+ /* Grab the module reference for this attribute if we have one */
+ error = -ENODEV;
+ if (!try_module_get(buffer->owner))
+ goto out_put_item;
+
+ error = -EACCES;
+ if (!buffer->item->ci_type)
+ goto out_put_module;
+
+ buffer->ops = buffer->item->ci_type->ct_item_ops;
/* File needs write support.
* The inode's perms must say it's ok,
@@ -395,13 +405,11 @@
*/
if (file->f_mode & FMODE_WRITE) {
if (!(inode->i_mode & S_IWUGO))
- goto Eaccess;
-
+ goto out_put_module;
if ((type & CONFIGFS_ITEM_ATTR) && !attr->store)
- goto Eaccess;
-
- if ((type & CONFIGFS_ITEM_BIN_ATTR) && !bin_attr->write)
- goto Eaccess;
+ goto out_put_module;
+ if ((type & CONFIGFS_ITEM_BIN_ATTR) && !buffer->bin_attr->write)
+ goto out_put_module;
}
/* File needs read support.
@@ -410,92 +418,72 @@
*/
if (file->f_mode & FMODE_READ) {
if (!(inode->i_mode & S_IRUGO))
- goto Eaccess;
-
+ goto out_put_module;
if ((type & CONFIGFS_ITEM_ATTR) && !attr->show)
- goto Eaccess;
-
- if ((type & CONFIGFS_ITEM_BIN_ATTR) && !bin_attr->read)
- goto Eaccess;
+ goto out_put_module;
+ if ((type & CONFIGFS_ITEM_BIN_ATTR) && !buffer->bin_attr->read)
+ goto out_put_module;
}
- /* No error? Great, allocate a buffer for the file, and store it
- * it in file->private_data for easy access.
- */
- buffer = kzalloc(sizeof(struct configfs_buffer),GFP_KERNEL);
- if (!buffer) {
- error = -ENOMEM;
- goto Enomem;
- }
mutex_init(&buffer->mutex);
buffer->needs_read_fill = 1;
buffer->read_in_progress = false;
buffer->write_in_progress = false;
- buffer->ops = ops;
file->private_data = buffer;
- goto Done;
+ up_read(&frag->frag_sem);
+ return 0;
- Einval:
- error = -EINVAL;
- goto Done;
- Eaccess:
- error = -EACCES;
- Enomem:
- module_put(attr->ca_owner);
- Done:
- if (error && item)
- config_item_put(item);
+out_put_module:
+ module_put(buffer->owner);
+out_put_item:
+ config_item_put(buffer->item);
+out_free_buffer:
+ up_read(&frag->frag_sem);
+ kfree(buffer);
+out:
return error;
}
static int configfs_release(struct inode *inode, struct file *filp)
{
- struct config_item * item = to_item(filp->f_path.dentry->d_parent);
- struct configfs_attribute * attr = to_attr(filp->f_path.dentry);
- struct module * owner = attr->ca_owner;
- struct configfs_buffer * buffer = filp->private_data;
+ struct configfs_buffer *buffer = filp->private_data;
- if (item)
- config_item_put(item);
- /* After this point, attr should not be accessed. */
- module_put(owner);
-
- if (buffer) {
- if (buffer->page)
- free_page((unsigned long)buffer->page);
- mutex_destroy(&buffer->mutex);
- kfree(buffer);
- }
+ module_put(buffer->owner);
+ if (buffer->page)
+ free_page((unsigned long)buffer->page);
+ mutex_destroy(&buffer->mutex);
+ kfree(buffer);
return 0;
}
static int configfs_open_file(struct inode *inode, struct file *filp)
{
- return check_perm(inode, filp, CONFIGFS_ITEM_ATTR);
+ return __configfs_open_file(inode, filp, CONFIGFS_ITEM_ATTR);
}
static int configfs_open_bin_file(struct inode *inode, struct file *filp)
{
- return check_perm(inode, filp, CONFIGFS_ITEM_BIN_ATTR);
+ return __configfs_open_file(inode, filp, CONFIGFS_ITEM_BIN_ATTR);
}
-static int configfs_release_bin_file(struct inode *inode, struct file *filp)
+static int configfs_release_bin_file(struct inode *inode, struct file *file)
{
- struct configfs_buffer *buffer = filp->private_data;
- struct dentry *dentry = filp->f_path.dentry;
- struct config_item *item = to_item(dentry->d_parent);
- struct configfs_bin_attribute *bin_attr = to_bin_attr(dentry);
- ssize_t len = 0;
- int ret;
+ struct configfs_buffer *buffer = file->private_data;
buffer->read_in_progress = false;
if (buffer->write_in_progress) {
+ struct configfs_fragment *frag = to_frag(file);
buffer->write_in_progress = false;
- len = bin_attr->write(item, buffer->bin_buffer,
- buffer->bin_buffer_size);
-
+ down_read(&frag->frag_sem);
+ if (!frag->frag_dead) {
+ /* result of ->release() is ignored */
+ buffer->bin_attr->write(buffer->item,
+ buffer->bin_buffer,
+ buffer->bin_buffer_size);
+ }
+ up_read(&frag->frag_sem);
/* vfree on NULL is safe */
vfree(buffer->bin_buffer);
buffer->bin_buffer = NULL;
@@ -503,10 +491,8 @@
buffer->needs_read_fill = 1;
}
- ret = configfs_release(inode, filp);
- if (len < 0)
- return len;
- return ret;
+ configfs_release(inode, file);
+ return 0;
}
@@ -541,7 +527,7 @@
inode_lock_nested(d_inode(dir), I_MUTEX_NORMAL);
error = configfs_make_dirent(parent_sd, NULL, (void *) attr, mode,
- CONFIGFS_ITEM_ATTR);
+ CONFIGFS_ITEM_ATTR, parent_sd->s_frag);
inode_unlock(d_inode(dir));
return error;
@@ -563,7 +549,7 @@
inode_lock_nested(dir->d_inode, I_MUTEX_NORMAL);
error = configfs_make_dirent(parent_sd, NULL, (void *) bin_attr, mode,
- CONFIGFS_ITEM_BIN_ATTR);
+ CONFIGFS_ITEM_BIN_ATTR, parent_sd->s_frag);
inode_unlock(dir->d_inode);
return error;
diff --git a/fs/configfs/inode.c b/fs/configfs/inode.c
index 28ef9e5..680aba9 100644
--- a/fs/configfs/inode.c
+++ b/fs/configfs/inode.c
@@ -1,23 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/* -*- mode: c; c-basic-offset: 8; -*-
* vim: noexpandtab sw=8 ts=8 sts=0:
*
* inode.c - basic inode and dentry operations.
*
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public
- * License along with this program; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 021110-1307, USA.
- *
* Based on sysfs:
* sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
*
@@ -90,14 +76,14 @@
if (ia_valid & ATTR_GID)
sd_iattr->ia_gid = iattr->ia_gid;
if (ia_valid & ATTR_ATIME)
- sd_iattr->ia_atime = timespec64_trunc(iattr->ia_atime,
- inode->i_sb->s_time_gran);
+ sd_iattr->ia_atime = timestamp_truncate(iattr->ia_atime,
+ inode);
if (ia_valid & ATTR_MTIME)
- sd_iattr->ia_mtime = timespec64_trunc(iattr->ia_mtime,
- inode->i_sb->s_time_gran);
+ sd_iattr->ia_mtime = timestamp_truncate(iattr->ia_mtime,
+ inode);
if (ia_valid & ATTR_CTIME)
- sd_iattr->ia_ctime = timespec64_trunc(iattr->ia_ctime,
- inode->i_sb->s_time_gran);
+ sd_iattr->ia_ctime = timestamp_truncate(iattr->ia_ctime,
+ inode);
if (ia_valid & ATTR_MODE) {
umode_t mode = iattr->ia_mode;
@@ -178,41 +164,27 @@
#endif /* CONFIG_LOCKDEP */
-int configfs_create(struct dentry * dentry, umode_t mode, void (*init)(struct inode *))
+struct inode *configfs_create(struct dentry *dentry, umode_t mode)
{
- int error = 0;
struct inode *inode = NULL;
struct configfs_dirent *sd;
struct inode *p_inode;
if (!dentry)
- return -ENOENT;
+ return ERR_PTR(-ENOENT);
if (d_really_is_positive(dentry))
- return -EEXIST;
+ return ERR_PTR(-EEXIST);
sd = dentry->d_fsdata;
inode = configfs_new_inode(mode, sd, dentry->d_sb);
if (!inode)
- return -ENOMEM;
+ return ERR_PTR(-ENOMEM);
p_inode = d_inode(dentry->d_parent);
p_inode->i_mtime = p_inode->i_ctime = current_time(p_inode);
configfs_set_inode_lock_class(sd, inode);
-
- init(inode);
- if (S_ISDIR(mode) || S_ISLNK(mode)) {
- /*
- * ->symlink(), ->mkdir(), configfs_register_subsystem() or
- * create_default_group() - already hashed.
- */
- d_instantiate(dentry, inode);
- dget(dentry); /* pin link and directory dentries in core */
- } else {
- /* ->lookup() */
- d_add(dentry, inode);
- }
- return error;
+ return inode;
}
/*
diff --git a/fs/configfs/item.c b/fs/configfs/item.c
index 99d491c..6e0f1fc 100644
--- a/fs/configfs/item.c
+++ b/fs/configfs/item.c
@@ -1,23 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/* -*- mode: c; c-basic-offset: 8; -*-
* vim: noexpandtab sw=8 ts=8 sts=0:
*
* item.c - library routines for handling generic config items
*
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public
- * License along with this program; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 021110-1307, USA.
- *
* Based on kobject:
* kobject is Copyright (c) 2002-2003 Patrick Mochel
*
diff --git a/fs/configfs/mount.c b/fs/configfs/mount.c
index cfd9132..0c6e8cf 100644
--- a/fs/configfs/mount.c
+++ b/fs/configfs/mount.c
@@ -1,23 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/* -*- mode: c; c-basic-offset: 8; -*-
* vim: noexpandtab sw=8 ts=8 sts=0:
*
* mount.c - operations for initializing and mounting configfs.
*
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public
- * License along with this program; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 021110-1307, USA.
- *
* Based on sysfs:
* sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
*
@@ -27,6 +13,7 @@
#include <linux/fs.h>
#include <linux/module.h>
#include <linux/mount.h>
+#include <linux/fs_context.h>
#include <linux/pagemap.h>
#include <linux/init.h>
#include <linux/slab.h>
@@ -41,9 +28,18 @@
struct kmem_cache *configfs_dir_cachep;
static int configfs_mnt_count = 0;
+
+static void configfs_free_inode(struct inode *inode)
+{
+ if (S_ISLNK(inode->i_mode))
+ kfree(inode->i_link);
+ free_inode_nonrcu(inode);
+}
+
static const struct super_operations configfs_ops = {
.statfs = simple_statfs,
.drop_inode = generic_delete_inode,
+ .free_inode = configfs_free_inode,
};
static struct config_group configfs_root_group = {
@@ -66,7 +62,7 @@
.s_iattr = NULL,
};
-static int configfs_fill_super(struct super_block *sb, void *data, int silent)
+static int configfs_fill_super(struct super_block *sb, struct fs_context *fc)
{
struct inode *inode;
struct dentry *root;
@@ -102,16 +98,25 @@
return 0;
}
-static struct dentry *configfs_do_mount(struct file_system_type *fs_type,
- int flags, const char *dev_name, void *data)
+static int configfs_get_tree(struct fs_context *fc)
{
- return mount_single(fs_type, flags, data, configfs_fill_super);
+ return get_tree_single(fc, configfs_fill_super);
+}
+
+static const struct fs_context_operations configfs_context_ops = {
+ .get_tree = configfs_get_tree,
+};
+
+static int configfs_init_fs_context(struct fs_context *fc)
+{
+ fc->ops = &configfs_context_ops;
+ return 0;
}
static struct file_system_type configfs_fs_type = {
.owner = THIS_MODULE,
.name = "configfs",
- .mount = configfs_do_mount,
+ .init_fs_context = configfs_init_fs_context,
.kill_sb = kill_litter_super,
};
MODULE_ALIAS_FS("configfs");
diff --git a/fs/configfs/symlink.c b/fs/configfs/symlink.c
index a5c54af..cb61467 100644
--- a/fs/configfs/symlink.c
+++ b/fs/configfs/symlink.c
@@ -1,23 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/* -*- mode: c; c-basic-offset: 8; -*-
* vim: noexpandtab sw=8 ts=8 sts=0:
*
* symlink.c - operations for configfs symlinks.
*
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public
- * License along with this program; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 021110-1307, USA.
- *
* Based on sysfs:
* sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
*
@@ -69,41 +55,63 @@
}
}
+static int configfs_get_target_path(struct config_item *item,
+ struct config_item *target, char *path)
+{
+ int depth, size;
+ char *s;
+
+ depth = item_depth(item);
+ size = item_path_length(target) + depth * 3 - 1;
+ if (size > PATH_MAX)
+ return -ENAMETOOLONG;
+
+ pr_debug("%s: depth = %d, size = %d\n", __func__, depth, size);
+
+ for (s = path; depth--; s += 3)
+ strcpy(s,"../");
+
+ fill_item_path(target, path, size);
+ pr_debug("%s: path = '%s'\n", __func__, path);
+ return 0;
+}
+
static int create_link(struct config_item *parent_item,
struct config_item *item,
struct dentry *dentry)
{
struct configfs_dirent *target_sd = item->ci_dentry->d_fsdata;
- struct configfs_symlink *sl;
+ char *body;
int ret;
- ret = -ENOENT;
if (!configfs_dirent_is_ready(target_sd))
- goto out;
- ret = -ENOMEM;
- sl = kmalloc(sizeof(struct configfs_symlink), GFP_KERNEL);
- if (sl) {
- spin_lock(&configfs_dirent_lock);
- if (target_sd->s_type & CONFIGFS_USET_DROPPING) {
- spin_unlock(&configfs_dirent_lock);
- kfree(sl);
- return -ENOENT;
- }
- sl->sl_target = config_item_get(item);
- list_add(&sl->sl_list, &target_sd->s_links);
- spin_unlock(&configfs_dirent_lock);
- ret = configfs_create_link(sl, parent_item->ci_dentry,
- dentry);
- if (ret) {
- spin_lock(&configfs_dirent_lock);
- list_del_init(&sl->sl_list);
- spin_unlock(&configfs_dirent_lock);
- config_item_put(item);
- kfree(sl);
- }
- }
+ return -ENOENT;
-out:
+ body = kzalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!body)
+ return -ENOMEM;
+
+ configfs_get(target_sd);
+ spin_lock(&configfs_dirent_lock);
+ if (target_sd->s_type & CONFIGFS_USET_DROPPING) {
+ spin_unlock(&configfs_dirent_lock);
+ configfs_put(target_sd);
+ kfree(body);
+ return -ENOENT;
+ }
+ target_sd->s_links++;
+ spin_unlock(&configfs_dirent_lock);
+ ret = configfs_get_target_path(parent_item, item, body);
+ if (!ret)
+ ret = configfs_create_link(target_sd, parent_item->ci_dentry,
+ dentry, body);
+ if (ret) {
+ spin_lock(&configfs_dirent_lock);
+ target_sd->s_links--;
+ spin_unlock(&configfs_dirent_lock);
+ configfs_put(target_sd);
+ kfree(body);
+ }
return ret;
}
@@ -145,9 +153,8 @@
* Fake invisibility if dir belongs to a group/default groups hierarchy
* being attached
*/
- ret = -ENOENT;
if (!configfs_dirent_is_ready(sd))
- goto out;
+ return -ENOENT;
parent_item = configfs_get_config_item(dentry->d_parent);
type = parent_item->ci_type;
@@ -157,11 +164,42 @@
!type->ct_item_ops->allow_link)
goto out_put;
+ /*
+ * This is really sick. What they wanted was a hybrid of
+ * link(2) and symlink(2) - they wanted the target resolved
+ * at syscall time (as link(2) would've done), be a directory
+ * (which link(2) would've refused to do) *AND* be a deep
+ * fucking magic, making the target busy from rmdir POV.
+ * symlink(2) is nothing of that sort, and the locking it
+ * gets matches the normal symlink(2) semantics. Without
+ * attempts to resolve the target (which might very well
+ * not even exist yet) done prior to locking the parent
+ * directory. This perversion, OTOH, needs to resolve
+ * the target, which would lead to obvious deadlocks if
+ * attempted with any directories locked.
+ *
+ * Unfortunately, that garbage is userland ABI and we should've
+ * said "no" back in 2005. Too late now, so we get to
+ * play very ugly games with locking.
+ *
+ * Try *ANYTHING* of that sort in new code, and you will
+ * really regret it. Just ask yourself - what could a BOFH
+ * do to me and do I want to find it out first-hand?
+ *
+ * AV, a thoroughly annoyed bastard.
+ */
+ inode_unlock(dir);
ret = get_target(symname, &path, &target_item, dentry->d_sb);
+ inode_lock(dir);
if (ret)
goto out_put;
- ret = type->ct_item_ops->allow_link(parent_item, target_item);
+ if (dentry->d_inode || d_unhashed(dentry))
+ ret = -EEXIST;
+ else
+ ret = inode_permission(dir, MAY_WRITE | MAY_EXEC);
+ if (!ret)
+ ret = type->ct_item_ops->allow_link(parent_item, target_item);
if (!ret) {
mutex_lock(&configfs_symlink_mutex);
ret = create_link(parent_item, target_item, dentry);
@@ -176,15 +214,12 @@
out_put:
config_item_put(parent_item);
-
-out:
return ret;
}
int configfs_unlink(struct inode *dir, struct dentry *dentry)
{
- struct configfs_dirent *sd = dentry->d_fsdata;
- struct configfs_symlink *sl;
+ struct configfs_dirent *sd = dentry->d_fsdata, *target_sd;
struct config_item *parent_item;
const struct config_item_type *type;
int ret;
@@ -193,7 +228,7 @@
if (!(sd->s_type & CONFIGFS_ITEM_LINK))
goto out;
- sl = sd->s_element;
+ target_sd = sd->s_element;
parent_item = configfs_get_config_item(dentry->d_parent);
type = parent_item->ci_type;
@@ -207,21 +242,18 @@
/*
* drop_link() must be called before
- * list_del_init(&sl->sl_list), so that the order of
+ * decrementing target's ->s_links, so that the order of
* drop_link(this, target) and drop_item(target) is preserved.
*/
if (type && type->ct_item_ops &&
type->ct_item_ops->drop_link)
type->ct_item_ops->drop_link(parent_item,
- sl->sl_target);
+ target_sd->s_element);
spin_lock(&configfs_dirent_lock);
- list_del_init(&sl->sl_list);
+ target_sd->s_links--;
spin_unlock(&configfs_dirent_lock);
-
- /* Put reference from create_link() */
- config_item_put(sl->sl_target);
- kfree(sl);
+ configfs_put(target_sd);
config_item_put(parent_item);
@@ -231,79 +263,8 @@
return ret;
}
-static int configfs_get_target_path(struct config_item * item, struct config_item * target,
- char *path)
-{
- char * s;
- int depth, size;
-
- depth = item_depth(item);
- size = item_path_length(target) + depth * 3 - 1;
- if (size > PATH_MAX)
- return -ENAMETOOLONG;
-
- pr_debug("%s: depth = %d, size = %d\n", __func__, depth, size);
-
- for (s = path; depth--; s += 3)
- strcpy(s,"../");
-
- fill_item_path(target, path, size);
- pr_debug("%s: path = '%s'\n", __func__, path);
-
- return 0;
-}
-
-static int configfs_getlink(struct dentry *dentry, char * path)
-{
- struct config_item *item, *target_item;
- int error = 0;
-
- item = configfs_get_config_item(dentry->d_parent);
- if (!item)
- return -EINVAL;
-
- target_item = configfs_get_config_item(dentry);
- if (!target_item) {
- config_item_put(item);
- return -EINVAL;
- }
-
- down_read(&configfs_rename_sem);
- error = configfs_get_target_path(item, target_item, path);
- up_read(&configfs_rename_sem);
-
- config_item_put(item);
- config_item_put(target_item);
- return error;
-
-}
-
-static const char *configfs_get_link(struct dentry *dentry,
- struct inode *inode,
- struct delayed_call *done)
-{
- char *body;
- int error;
-
- if (!dentry)
- return ERR_PTR(-ECHILD);
-
- body = kzalloc(PAGE_SIZE, GFP_KERNEL);
- if (!body)
- return ERR_PTR(-ENOMEM);
-
- error = configfs_getlink(dentry, body);
- if (!error) {
- set_delayed_call(done, kfree_link, body);
- return body;
- }
-
- kfree(body);
- return ERR_PTR(error);
-}
-
const struct inode_operations configfs_symlink_inode_operations = {
- .get_link = configfs_get_link,
+ .get_link = simple_get_link,
.setattr = configfs_setattr,
};