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![Amir Goldstein](/assets/img/avatar_default.png)
Push clamping timestamps into notify_change(), so in-kernel
callers like nfsd and overlayfs will get similar timestamp
set behavior as utimes.
AV: get rid of clamping in ->setattr() instances; we don't need
to bother with that there, with notify_change() doing normalization
in all cases now (it already did for implicit case, since current_time()
clamps).
Suggested-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: 42e729b9dd
("utimes: Clamp the timestamps before update")
Cc: stable@vger.kernel.org # v5.4
Cc: Deepa Dinamani <deepa.kernel@gmail.com>
Cc: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
251 lines
6.2 KiB
C
251 lines
6.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/* -*- mode: c; c-basic-offset: 8; -*-
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* vim: noexpandtab sw=8 ts=8 sts=0:
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*
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* inode.c - basic inode and dentry operations.
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*
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* Based on sysfs:
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* sysfs is Copyright (C) 2001, 2002, 2003 Patrick Mochel
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*
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* configfs Copyright (C) 2005 Oracle. All rights reserved.
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*
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* Please see Documentation/filesystems/configfs/configfs.txt for more
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* information.
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*/
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#undef DEBUG
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#include <linux/pagemap.h>
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#include <linux/namei.h>
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#include <linux/backing-dev.h>
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#include <linux/capability.h>
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#include <linux/sched.h>
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#include <linux/lockdep.h>
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#include <linux/slab.h>
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#include <linux/configfs.h>
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#include "configfs_internal.h"
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#ifdef CONFIG_LOCKDEP
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static struct lock_class_key default_group_class[MAX_LOCK_DEPTH];
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#endif
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static const struct address_space_operations configfs_aops = {
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.readpage = simple_readpage,
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.write_begin = simple_write_begin,
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.write_end = simple_write_end,
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};
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static const struct inode_operations configfs_inode_operations ={
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.setattr = configfs_setattr,
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};
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int configfs_setattr(struct dentry * dentry, struct iattr * iattr)
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{
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struct inode * inode = d_inode(dentry);
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struct configfs_dirent * sd = dentry->d_fsdata;
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struct iattr * sd_iattr;
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unsigned int ia_valid = iattr->ia_valid;
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int error;
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if (!sd)
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return -EINVAL;
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sd_iattr = sd->s_iattr;
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if (!sd_iattr) {
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/* setting attributes for the first time, allocate now */
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sd_iattr = kzalloc(sizeof(struct iattr), GFP_KERNEL);
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if (!sd_iattr)
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return -ENOMEM;
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/* assign default attributes */
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sd_iattr->ia_mode = sd->s_mode;
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sd_iattr->ia_uid = GLOBAL_ROOT_UID;
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sd_iattr->ia_gid = GLOBAL_ROOT_GID;
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sd_iattr->ia_atime = sd_iattr->ia_mtime =
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sd_iattr->ia_ctime = current_time(inode);
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sd->s_iattr = sd_iattr;
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}
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/* attributes were changed atleast once in past */
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error = simple_setattr(dentry, iattr);
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if (error)
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return error;
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if (ia_valid & ATTR_UID)
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sd_iattr->ia_uid = iattr->ia_uid;
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if (ia_valid & ATTR_GID)
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sd_iattr->ia_gid = iattr->ia_gid;
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if (ia_valid & ATTR_ATIME)
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sd_iattr->ia_atime = iattr->ia_atime;
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if (ia_valid & ATTR_MTIME)
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sd_iattr->ia_mtime = iattr->ia_mtime;
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if (ia_valid & ATTR_CTIME)
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sd_iattr->ia_ctime = iattr->ia_ctime;
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if (ia_valid & ATTR_MODE) {
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umode_t mode = iattr->ia_mode;
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if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
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mode &= ~S_ISGID;
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sd_iattr->ia_mode = sd->s_mode = mode;
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}
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return error;
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}
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static inline void set_default_inode_attr(struct inode * inode, umode_t mode)
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{
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inode->i_mode = mode;
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inode->i_atime = inode->i_mtime =
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inode->i_ctime = current_time(inode);
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}
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static inline void set_inode_attr(struct inode * inode, struct iattr * iattr)
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{
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inode->i_mode = iattr->ia_mode;
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inode->i_uid = iattr->ia_uid;
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inode->i_gid = iattr->ia_gid;
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inode->i_atime = iattr->ia_atime;
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inode->i_mtime = iattr->ia_mtime;
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inode->i_ctime = iattr->ia_ctime;
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}
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struct inode *configfs_new_inode(umode_t mode, struct configfs_dirent *sd,
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struct super_block *s)
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{
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struct inode * inode = new_inode(s);
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if (inode) {
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inode->i_ino = get_next_ino();
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inode->i_mapping->a_ops = &configfs_aops;
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inode->i_op = &configfs_inode_operations;
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if (sd->s_iattr) {
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/* sysfs_dirent has non-default attributes
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* get them for the new inode from persistent copy
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* in sysfs_dirent
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*/
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set_inode_attr(inode, sd->s_iattr);
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} else
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set_default_inode_attr(inode, mode);
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}
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return inode;
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}
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#ifdef CONFIG_LOCKDEP
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static void configfs_set_inode_lock_class(struct configfs_dirent *sd,
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struct inode *inode)
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{
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int depth = sd->s_depth;
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if (depth > 0) {
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if (depth <= ARRAY_SIZE(default_group_class)) {
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lockdep_set_class(&inode->i_rwsem,
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&default_group_class[depth - 1]);
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} else {
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/*
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* In practice the maximum level of locking depth is
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* already reached. Just inform about possible reasons.
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*/
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pr_info("Too many levels of inodes for the locking correctness validator.\n");
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pr_info("Spurious warnings may appear.\n");
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}
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}
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}
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#else /* CONFIG_LOCKDEP */
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static void configfs_set_inode_lock_class(struct configfs_dirent *sd,
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struct inode *inode)
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{
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}
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#endif /* CONFIG_LOCKDEP */
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struct inode *configfs_create(struct dentry *dentry, umode_t mode)
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{
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struct inode *inode = NULL;
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struct configfs_dirent *sd;
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struct inode *p_inode;
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if (!dentry)
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return ERR_PTR(-ENOENT);
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if (d_really_is_positive(dentry))
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return ERR_PTR(-EEXIST);
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sd = dentry->d_fsdata;
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inode = configfs_new_inode(mode, sd, dentry->d_sb);
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if (!inode)
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return ERR_PTR(-ENOMEM);
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p_inode = d_inode(dentry->d_parent);
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p_inode->i_mtime = p_inode->i_ctime = current_time(p_inode);
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configfs_set_inode_lock_class(sd, inode);
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return inode;
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}
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/*
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* Get the name for corresponding element represented by the given configfs_dirent
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*/
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const unsigned char * configfs_get_name(struct configfs_dirent *sd)
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{
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struct configfs_attribute *attr;
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BUG_ON(!sd || !sd->s_element);
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/* These always have a dentry, so use that */
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if (sd->s_type & (CONFIGFS_DIR | CONFIGFS_ITEM_LINK))
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return sd->s_dentry->d_name.name;
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if (sd->s_type & (CONFIGFS_ITEM_ATTR | CONFIGFS_ITEM_BIN_ATTR)) {
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attr = sd->s_element;
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return attr->ca_name;
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}
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return NULL;
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}
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/*
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* Unhashes the dentry corresponding to given configfs_dirent
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* Called with parent inode's i_mutex held.
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*/
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void configfs_drop_dentry(struct configfs_dirent * sd, struct dentry * parent)
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{
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struct dentry * dentry = sd->s_dentry;
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if (dentry) {
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spin_lock(&dentry->d_lock);
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if (simple_positive(dentry)) {
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dget_dlock(dentry);
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__d_drop(dentry);
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spin_unlock(&dentry->d_lock);
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simple_unlink(d_inode(parent), dentry);
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} else
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spin_unlock(&dentry->d_lock);
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}
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}
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void configfs_hash_and_remove(struct dentry * dir, const char * name)
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{
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struct configfs_dirent * sd;
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struct configfs_dirent * parent_sd = dir->d_fsdata;
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if (d_really_is_negative(dir))
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/* no inode means this hasn't been made visible yet */
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return;
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inode_lock(d_inode(dir));
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list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
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if (!sd->s_element)
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continue;
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if (!strcmp(configfs_get_name(sd), name)) {
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spin_lock(&configfs_dirent_lock);
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list_del_init(&sd->s_sibling);
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spin_unlock(&configfs_dirent_lock);
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configfs_drop_dentry(sd, dir);
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configfs_put(sd);
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break;
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}
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}
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inode_unlock(d_inode(dir));
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}
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