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![Stefan Bader](/assets/img/avatar_default.png)
BugLink: http://bugs.launchpad.net/ubuntu/+bug/396780
Commit 073aaa1b14
"helpers for acl
caching + switch to those" introduced new helper functions for
acl handling but seems to have introduced a regression for jfs as
the acl is released before returning it to the caller, instead of
leaving this for the caller to do.
This causes the acl object to be used after freeing it, leading
to kernel panics in completely different places.
Thanks to Christophe Dumez for reporting and bisecting into this.
Reported-by: Christophe Dumez <dchris@gmail.com>
Tested-by: Christophe Dumez <dchris@gmail.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
235 lines
5.2 KiB
C
235 lines
5.2 KiB
C
/*
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* Copyright (C) International Business Machines Corp., 2002-2004
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* Copyright (C) Andreas Gruenbacher, 2001
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* Copyright (C) Linus Torvalds, 1991, 1992
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
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* the GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <linux/sched.h>
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#include <linux/fs.h>
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#include <linux/quotaops.h>
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#include <linux/posix_acl_xattr.h>
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#include "jfs_incore.h"
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#include "jfs_txnmgr.h"
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#include "jfs_xattr.h"
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#include "jfs_acl.h"
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static struct posix_acl *jfs_get_acl(struct inode *inode, int type)
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{
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struct posix_acl *acl;
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char *ea_name;
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int size;
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char *value = NULL;
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acl = get_cached_acl(inode, type);
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if (acl != ACL_NOT_CACHED)
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return acl;
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switch(type) {
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case ACL_TYPE_ACCESS:
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ea_name = POSIX_ACL_XATTR_ACCESS;
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break;
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case ACL_TYPE_DEFAULT:
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ea_name = POSIX_ACL_XATTR_DEFAULT;
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break;
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default:
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return ERR_PTR(-EINVAL);
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}
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size = __jfs_getxattr(inode, ea_name, NULL, 0);
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if (size > 0) {
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value = kmalloc(size, GFP_KERNEL);
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if (!value)
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return ERR_PTR(-ENOMEM);
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size = __jfs_getxattr(inode, ea_name, value, size);
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}
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if (size < 0) {
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if (size == -ENODATA)
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acl = NULL;
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else
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acl = ERR_PTR(size);
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} else {
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acl = posix_acl_from_xattr(value, size);
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}
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kfree(value);
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if (!IS_ERR(acl))
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set_cached_acl(inode, type, acl);
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return acl;
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}
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static int jfs_set_acl(tid_t tid, struct inode *inode, int type,
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struct posix_acl *acl)
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{
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char *ea_name;
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int rc;
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int size = 0;
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char *value = NULL;
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if (S_ISLNK(inode->i_mode))
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return -EOPNOTSUPP;
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switch(type) {
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case ACL_TYPE_ACCESS:
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ea_name = POSIX_ACL_XATTR_ACCESS;
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break;
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case ACL_TYPE_DEFAULT:
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ea_name = POSIX_ACL_XATTR_DEFAULT;
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if (!S_ISDIR(inode->i_mode))
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return acl ? -EACCES : 0;
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break;
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default:
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return -EINVAL;
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}
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if (acl) {
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size = posix_acl_xattr_size(acl->a_count);
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value = kmalloc(size, GFP_KERNEL);
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if (!value)
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return -ENOMEM;
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rc = posix_acl_to_xattr(acl, value, size);
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if (rc < 0)
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goto out;
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}
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rc = __jfs_setxattr(tid, inode, ea_name, value, size, 0);
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out:
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kfree(value);
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if (!rc)
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set_cached_acl(inode, type, acl);
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return rc;
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}
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static int jfs_check_acl(struct inode *inode, int mask)
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{
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struct posix_acl *acl = jfs_get_acl(inode, ACL_TYPE_ACCESS);
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if (IS_ERR(acl))
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return PTR_ERR(acl);
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if (acl) {
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int error = posix_acl_permission(inode, acl, mask);
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posix_acl_release(acl);
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return error;
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}
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return -EAGAIN;
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}
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int jfs_permission(struct inode *inode, int mask)
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{
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return generic_permission(inode, mask, jfs_check_acl);
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}
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int jfs_init_acl(tid_t tid, struct inode *inode, struct inode *dir)
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{
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struct posix_acl *acl = NULL;
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struct posix_acl *clone;
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mode_t mode;
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int rc = 0;
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if (S_ISLNK(inode->i_mode))
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return 0;
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acl = jfs_get_acl(dir, ACL_TYPE_DEFAULT);
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if (IS_ERR(acl))
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return PTR_ERR(acl);
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if (acl) {
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if (S_ISDIR(inode->i_mode)) {
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rc = jfs_set_acl(tid, inode, ACL_TYPE_DEFAULT, acl);
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if (rc)
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goto cleanup;
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}
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clone = posix_acl_clone(acl, GFP_KERNEL);
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if (!clone) {
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rc = -ENOMEM;
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goto cleanup;
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}
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mode = inode->i_mode;
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rc = posix_acl_create_masq(clone, &mode);
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if (rc >= 0) {
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inode->i_mode = mode;
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if (rc > 0)
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rc = jfs_set_acl(tid, inode, ACL_TYPE_ACCESS,
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clone);
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}
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posix_acl_release(clone);
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cleanup:
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posix_acl_release(acl);
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} else
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inode->i_mode &= ~current_umask();
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JFS_IP(inode)->mode2 = (JFS_IP(inode)->mode2 & 0xffff0000) |
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inode->i_mode;
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return rc;
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}
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static int jfs_acl_chmod(struct inode *inode)
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{
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struct posix_acl *acl, *clone;
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int rc;
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if (S_ISLNK(inode->i_mode))
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return -EOPNOTSUPP;
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acl = jfs_get_acl(inode, ACL_TYPE_ACCESS);
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if (IS_ERR(acl) || !acl)
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return PTR_ERR(acl);
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clone = posix_acl_clone(acl, GFP_KERNEL);
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posix_acl_release(acl);
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if (!clone)
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return -ENOMEM;
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rc = posix_acl_chmod_masq(clone, inode->i_mode);
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if (!rc) {
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tid_t tid = txBegin(inode->i_sb, 0);
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mutex_lock(&JFS_IP(inode)->commit_mutex);
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rc = jfs_set_acl(tid, inode, ACL_TYPE_ACCESS, clone);
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if (!rc)
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rc = txCommit(tid, 1, &inode, 0);
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txEnd(tid);
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mutex_unlock(&JFS_IP(inode)->commit_mutex);
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}
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posix_acl_release(clone);
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return rc;
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}
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int jfs_setattr(struct dentry *dentry, struct iattr *iattr)
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{
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struct inode *inode = dentry->d_inode;
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int rc;
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rc = inode_change_ok(inode, iattr);
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if (rc)
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return rc;
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if ((iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid) ||
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(iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid)) {
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if (vfs_dq_transfer(inode, iattr))
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return -EDQUOT;
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}
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rc = inode_setattr(inode, iattr);
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if (!rc && (iattr->ia_valid & ATTR_MODE))
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rc = jfs_acl_chmod(inode);
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return rc;
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}
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