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16c8d569f5
The race between *set_acl and *get_acl will cause getting incomplete xattr data as below: processA processB ocfs2_set_acl ocfs2_xattr_set __ocfs2_xattr_set_handle ocfs2_get_acl_nolock ocfs2_xattr_get_nolock: processB may get incomplete xattr data if processA hasn't set_acl done. So we should use 'ip_xattr_sem' to protect getting extended attribute in ocfs2_get_acl_nolock(), as other processes could be changing it concurrently. Link: http://lkml.kernel.org/r/5A5DDCFF.7030001@huawei.com Signed-off-by: Jun Piao <piaojun@huawei.com> Reviewed-by: Alex Chen <alex.chen@huawei.com> Cc: Mark Fasheh <mfasheh@versity.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Joseph Qi <jiangqi903@gmail.com> Cc: Changwei Ge <ge.changwei@h3c.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
413 lines
9.5 KiB
C
413 lines
9.5 KiB
C
/* -*- 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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* acl.c
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*
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* Copyright (C) 2004, 2008 Oracle. All rights reserved.
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*
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* CREDITS:
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* Lots of code in this file is copy from linux/fs/ext3/acl.c.
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* Copyright (C) 2001-2003 Andreas Gruenbacher, <agruen@suse.de>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public
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* License version 2 as published by the Free Software Foundation.
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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 the GNU
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* General Public License for more details.
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*/
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <linux/string.h>
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#include <cluster/masklog.h>
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#include "ocfs2.h"
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#include "alloc.h"
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#include "dlmglue.h"
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#include "file.h"
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#include "inode.h"
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#include "journal.h"
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#include "ocfs2_fs.h"
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#include "xattr.h"
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#include "acl.h"
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/*
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* Convert from xattr value to acl struct.
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*/
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static struct posix_acl *ocfs2_acl_from_xattr(const void *value, size_t size)
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{
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int n, count;
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struct posix_acl *acl;
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if (!value)
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return NULL;
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if (size < sizeof(struct posix_acl_entry))
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return ERR_PTR(-EINVAL);
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count = size / sizeof(struct posix_acl_entry);
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acl = posix_acl_alloc(count, GFP_NOFS);
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if (!acl)
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return ERR_PTR(-ENOMEM);
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for (n = 0; n < count; n++) {
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struct ocfs2_acl_entry *entry =
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(struct ocfs2_acl_entry *)value;
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acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag);
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acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm);
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switch(acl->a_entries[n].e_tag) {
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case ACL_USER:
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acl->a_entries[n].e_uid =
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make_kuid(&init_user_ns,
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le32_to_cpu(entry->e_id));
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break;
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case ACL_GROUP:
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acl->a_entries[n].e_gid =
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make_kgid(&init_user_ns,
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le32_to_cpu(entry->e_id));
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break;
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default:
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break;
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}
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value += sizeof(struct posix_acl_entry);
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}
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return acl;
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}
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/*
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* Convert acl struct to xattr value.
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*/
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static void *ocfs2_acl_to_xattr(const struct posix_acl *acl, size_t *size)
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{
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struct ocfs2_acl_entry *entry = NULL;
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char *ocfs2_acl;
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size_t n;
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*size = acl->a_count * sizeof(struct posix_acl_entry);
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ocfs2_acl = kmalloc(*size, GFP_NOFS);
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if (!ocfs2_acl)
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return ERR_PTR(-ENOMEM);
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entry = (struct ocfs2_acl_entry *)ocfs2_acl;
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for (n = 0; n < acl->a_count; n++, entry++) {
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entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag);
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entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm);
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switch(acl->a_entries[n].e_tag) {
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case ACL_USER:
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entry->e_id = cpu_to_le32(
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from_kuid(&init_user_ns,
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acl->a_entries[n].e_uid));
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break;
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case ACL_GROUP:
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entry->e_id = cpu_to_le32(
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from_kgid(&init_user_ns,
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acl->a_entries[n].e_gid));
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break;
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default:
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entry->e_id = cpu_to_le32(ACL_UNDEFINED_ID);
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break;
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}
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}
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return ocfs2_acl;
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}
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static struct posix_acl *ocfs2_get_acl_nolock(struct inode *inode,
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int type,
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struct buffer_head *di_bh)
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{
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int name_index;
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char *value = NULL;
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struct posix_acl *acl;
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int retval;
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switch (type) {
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case ACL_TYPE_ACCESS:
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name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
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break;
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case ACL_TYPE_DEFAULT:
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name_index = OCFS2_XATTR_INDEX_POSIX_ACL_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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retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index, "", NULL, 0);
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if (retval > 0) {
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value = kmalloc(retval, GFP_NOFS);
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if (!value)
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return ERR_PTR(-ENOMEM);
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retval = ocfs2_xattr_get_nolock(inode, di_bh, name_index,
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"", value, retval);
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}
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if (retval > 0)
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acl = ocfs2_acl_from_xattr(value, retval);
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else if (retval == -ENODATA || retval == 0)
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acl = NULL;
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else
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acl = ERR_PTR(retval);
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kfree(value);
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return acl;
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}
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/*
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* Helper function to set i_mode in memory and disk. Some call paths
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* will not have di_bh or a journal handle to pass, in which case it
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* will create it's own.
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*/
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static int ocfs2_acl_set_mode(struct inode *inode, struct buffer_head *di_bh,
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handle_t *handle, umode_t new_mode)
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{
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int ret, commit_handle = 0;
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struct ocfs2_dinode *di;
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if (di_bh == NULL) {
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ret = ocfs2_read_inode_block(inode, &di_bh);
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if (ret) {
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mlog_errno(ret);
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goto out;
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}
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} else
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get_bh(di_bh);
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if (handle == NULL) {
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handle = ocfs2_start_trans(OCFS2_SB(inode->i_sb),
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OCFS2_INODE_UPDATE_CREDITS);
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if (IS_ERR(handle)) {
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ret = PTR_ERR(handle);
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mlog_errno(ret);
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goto out_brelse;
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}
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commit_handle = 1;
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}
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di = (struct ocfs2_dinode *)di_bh->b_data;
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ret = ocfs2_journal_access_di(handle, INODE_CACHE(inode), di_bh,
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OCFS2_JOURNAL_ACCESS_WRITE);
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if (ret) {
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mlog_errno(ret);
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goto out_commit;
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}
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inode->i_mode = new_mode;
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inode->i_ctime = current_time(inode);
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di->i_mode = cpu_to_le16(inode->i_mode);
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di->i_ctime = cpu_to_le64(inode->i_ctime.tv_sec);
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di->i_ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
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ocfs2_update_inode_fsync_trans(handle, inode, 0);
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ocfs2_journal_dirty(handle, di_bh);
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out_commit:
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if (commit_handle)
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ocfs2_commit_trans(OCFS2_SB(inode->i_sb), handle);
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out_brelse:
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brelse(di_bh);
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out:
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return ret;
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}
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/*
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* Set the access or default ACL of an inode.
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*/
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static int ocfs2_set_acl(handle_t *handle,
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struct inode *inode,
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struct buffer_head *di_bh,
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int type,
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struct posix_acl *acl,
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struct ocfs2_alloc_context *meta_ac,
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struct ocfs2_alloc_context *data_ac)
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{
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int name_index;
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void *value = NULL;
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size_t size = 0;
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int ret;
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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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name_index = OCFS2_XATTR_INDEX_POSIX_ACL_ACCESS;
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break;
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case ACL_TYPE_DEFAULT:
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name_index = OCFS2_XATTR_INDEX_POSIX_ACL_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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value = ocfs2_acl_to_xattr(acl, &size);
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if (IS_ERR(value))
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return (int)PTR_ERR(value);
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}
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if (handle)
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ret = ocfs2_xattr_set_handle(handle, inode, di_bh, name_index,
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"", value, size, 0,
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meta_ac, data_ac);
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else
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ret = ocfs2_xattr_set(inode, name_index, "", value, size, 0);
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kfree(value);
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return ret;
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}
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int ocfs2_iop_set_acl(struct inode *inode, struct posix_acl *acl, int type)
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{
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struct buffer_head *bh = NULL;
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int status, had_lock;
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struct ocfs2_lock_holder oh;
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had_lock = ocfs2_inode_lock_tracker(inode, &bh, 1, &oh);
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if (had_lock < 0)
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return had_lock;
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if (type == ACL_TYPE_ACCESS && acl) {
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umode_t mode;
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status = posix_acl_update_mode(inode, &mode, &acl);
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if (status)
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goto unlock;
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status = ocfs2_acl_set_mode(inode, bh, NULL, mode);
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if (status)
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goto unlock;
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}
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status = ocfs2_set_acl(NULL, inode, bh, type, acl, NULL, NULL);
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unlock:
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ocfs2_inode_unlock_tracker(inode, 1, &oh, had_lock);
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brelse(bh);
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return status;
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}
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struct posix_acl *ocfs2_iop_get_acl(struct inode *inode, int type)
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{
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struct ocfs2_super *osb;
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struct buffer_head *di_bh = NULL;
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struct posix_acl *acl;
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int had_lock;
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struct ocfs2_lock_holder oh;
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osb = OCFS2_SB(inode->i_sb);
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if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
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return NULL;
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had_lock = ocfs2_inode_lock_tracker(inode, &di_bh, 0, &oh);
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if (had_lock < 0)
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return ERR_PTR(had_lock);
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down_read(&OCFS2_I(inode)->ip_xattr_sem);
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acl = ocfs2_get_acl_nolock(inode, type, di_bh);
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up_read(&OCFS2_I(inode)->ip_xattr_sem);
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ocfs2_inode_unlock_tracker(inode, 0, &oh, had_lock);
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brelse(di_bh);
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return acl;
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}
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int ocfs2_acl_chmod(struct inode *inode, struct buffer_head *bh)
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{
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struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
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struct posix_acl *acl;
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int ret;
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if (S_ISLNK(inode->i_mode))
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return -EOPNOTSUPP;
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if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL))
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return 0;
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down_read(&OCFS2_I(inode)->ip_xattr_sem);
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acl = ocfs2_get_acl_nolock(inode, ACL_TYPE_ACCESS, bh);
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up_read(&OCFS2_I(inode)->ip_xattr_sem);
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if (IS_ERR(acl) || !acl)
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return PTR_ERR(acl);
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ret = __posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
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if (ret)
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return ret;
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ret = ocfs2_set_acl(NULL, inode, NULL, ACL_TYPE_ACCESS,
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acl, NULL, NULL);
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posix_acl_release(acl);
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return ret;
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}
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/*
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* Initialize the ACLs of a new inode. If parent directory has default ACL,
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* then clone to new inode. Called from ocfs2_mknod.
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*/
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int ocfs2_init_acl(handle_t *handle,
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struct inode *inode,
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struct inode *dir,
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struct buffer_head *di_bh,
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struct buffer_head *dir_bh,
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struct ocfs2_alloc_context *meta_ac,
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struct ocfs2_alloc_context *data_ac)
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{
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struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
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struct posix_acl *acl = NULL;
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int ret = 0, ret2;
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umode_t mode;
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if (!S_ISLNK(inode->i_mode)) {
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if (osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) {
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down_read(&OCFS2_I(dir)->ip_xattr_sem);
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acl = ocfs2_get_acl_nolock(dir, ACL_TYPE_DEFAULT,
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dir_bh);
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up_read(&OCFS2_I(dir)->ip_xattr_sem);
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if (IS_ERR(acl))
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return PTR_ERR(acl);
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}
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if (!acl) {
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mode = inode->i_mode & ~current_umask();
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ret = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
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if (ret) {
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mlog_errno(ret);
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goto cleanup;
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}
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}
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}
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if ((osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL) && acl) {
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if (S_ISDIR(inode->i_mode)) {
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ret = ocfs2_set_acl(handle, inode, di_bh,
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ACL_TYPE_DEFAULT, acl,
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meta_ac, data_ac);
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if (ret)
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goto cleanup;
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}
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mode = inode->i_mode;
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ret = __posix_acl_create(&acl, GFP_NOFS, &mode);
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if (ret < 0)
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return ret;
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ret2 = ocfs2_acl_set_mode(inode, di_bh, handle, mode);
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if (ret2) {
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mlog_errno(ret2);
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ret = ret2;
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goto cleanup;
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}
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if (ret > 0) {
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ret = ocfs2_set_acl(handle, inode,
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di_bh, ACL_TYPE_ACCESS,
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acl, meta_ac, data_ac);
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}
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}
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cleanup:
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posix_acl_release(acl);
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return ret;
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}
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