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https://github.com/torvalds/linux
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272e083f7a
Our f2fs_acl_create is copied from posix_acl_create in ./fs/posix_acl.c and
modified to avoid deadlock bug when inline_dentry feature is enabled.
Dan Carpenter rewrites posix_acl_create in commit 2799563b281f
("fs/posix_acl.c: make posix_acl_create() safer and cleaner") to make this
function more safer, so that we can avoid potential bug in its caller,
especially for ocfs2.
Let's back port the patch to f2fs.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
404 lines
8.8 KiB
C
404 lines
8.8 KiB
C
/*
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* fs/f2fs/acl.c
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*
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* Copyright (c) 2012 Samsung Electronics Co., Ltd.
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* http://www.samsung.com/
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*
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* Portions of this code from linux/fs/ext2/acl.c
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*
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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 modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/f2fs_fs.h>
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#include "f2fs.h"
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#include "xattr.h"
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#include "acl.h"
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static inline size_t f2fs_acl_size(int count)
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{
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if (count <= 4) {
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return sizeof(struct f2fs_acl_header) +
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count * sizeof(struct f2fs_acl_entry_short);
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} else {
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return sizeof(struct f2fs_acl_header) +
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4 * sizeof(struct f2fs_acl_entry_short) +
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(count - 4) * sizeof(struct f2fs_acl_entry);
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}
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}
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static inline int f2fs_acl_count(size_t size)
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{
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ssize_t s;
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size -= sizeof(struct f2fs_acl_header);
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s = size - 4 * sizeof(struct f2fs_acl_entry_short);
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if (s < 0) {
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if (size % sizeof(struct f2fs_acl_entry_short))
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return -1;
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return size / sizeof(struct f2fs_acl_entry_short);
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} else {
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if (s % sizeof(struct f2fs_acl_entry))
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return -1;
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return s / sizeof(struct f2fs_acl_entry) + 4;
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}
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}
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static struct posix_acl *f2fs_acl_from_disk(const char *value, size_t size)
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{
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int i, count;
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struct posix_acl *acl;
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struct f2fs_acl_header *hdr = (struct f2fs_acl_header *)value;
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struct f2fs_acl_entry *entry = (struct f2fs_acl_entry *)(hdr + 1);
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const char *end = value + size;
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if (hdr->a_version != cpu_to_le32(F2FS_ACL_VERSION))
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return ERR_PTR(-EINVAL);
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count = f2fs_acl_count(size);
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if (count < 0)
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return ERR_PTR(-EINVAL);
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if (count == 0)
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return NULL;
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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 (i = 0; i < count; i++) {
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if ((char *)entry > end)
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goto fail;
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acl->a_entries[i].e_tag = le16_to_cpu(entry->e_tag);
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acl->a_entries[i].e_perm = le16_to_cpu(entry->e_perm);
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switch (acl->a_entries[i].e_tag) {
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case ACL_USER_OBJ:
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case ACL_GROUP_OBJ:
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case ACL_MASK:
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case ACL_OTHER:
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entry = (struct f2fs_acl_entry *)((char *)entry +
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sizeof(struct f2fs_acl_entry_short));
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break;
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case ACL_USER:
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acl->a_entries[i].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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entry = (struct f2fs_acl_entry *)((char *)entry +
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sizeof(struct f2fs_acl_entry));
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break;
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case ACL_GROUP:
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acl->a_entries[i].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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entry = (struct f2fs_acl_entry *)((char *)entry +
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sizeof(struct f2fs_acl_entry));
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break;
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default:
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goto fail;
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}
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}
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if ((char *)entry != end)
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goto fail;
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return acl;
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fail:
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posix_acl_release(acl);
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return ERR_PTR(-EINVAL);
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}
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static void *f2fs_acl_to_disk(const struct posix_acl *acl, size_t *size)
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{
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struct f2fs_acl_header *f2fs_acl;
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struct f2fs_acl_entry *entry;
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int i;
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f2fs_acl = kmalloc(sizeof(struct f2fs_acl_header) + acl->a_count *
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sizeof(struct f2fs_acl_entry), GFP_NOFS);
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if (!f2fs_acl)
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return ERR_PTR(-ENOMEM);
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f2fs_acl->a_version = cpu_to_le32(F2FS_ACL_VERSION);
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entry = (struct f2fs_acl_entry *)(f2fs_acl + 1);
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for (i = 0; i < acl->a_count; i++) {
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entry->e_tag = cpu_to_le16(acl->a_entries[i].e_tag);
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entry->e_perm = cpu_to_le16(acl->a_entries[i].e_perm);
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switch (acl->a_entries[i].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[i].e_uid));
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entry = (struct f2fs_acl_entry *)((char *)entry +
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sizeof(struct f2fs_acl_entry));
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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[i].e_gid));
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entry = (struct f2fs_acl_entry *)((char *)entry +
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sizeof(struct f2fs_acl_entry));
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break;
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case ACL_USER_OBJ:
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case ACL_GROUP_OBJ:
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case ACL_MASK:
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case ACL_OTHER:
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entry = (struct f2fs_acl_entry *)((char *)entry +
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sizeof(struct f2fs_acl_entry_short));
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break;
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default:
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goto fail;
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}
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}
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*size = f2fs_acl_size(acl->a_count);
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return (void *)f2fs_acl;
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fail:
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kfree(f2fs_acl);
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return ERR_PTR(-EINVAL);
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}
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static struct posix_acl *__f2fs_get_acl(struct inode *inode, int type,
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struct page *dpage)
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{
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int name_index = F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT;
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void *value = NULL;
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struct posix_acl *acl;
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int retval;
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if (type == ACL_TYPE_ACCESS)
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name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;
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retval = f2fs_getxattr(inode, name_index, "", NULL, 0, dpage);
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if (retval > 0) {
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value = kmalloc(retval, GFP_F2FS_ZERO);
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if (!value)
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return ERR_PTR(-ENOMEM);
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retval = f2fs_getxattr(inode, name_index, "", value,
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retval, dpage);
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}
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if (retval > 0)
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acl = f2fs_acl_from_disk(value, retval);
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else if (retval == -ENODATA)
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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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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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struct posix_acl *f2fs_get_acl(struct inode *inode, int type)
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{
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return __f2fs_get_acl(inode, type, NULL);
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}
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static int __f2fs_set_acl(struct inode *inode, int type,
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struct posix_acl *acl, struct page *ipage)
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{
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struct f2fs_inode_info *fi = F2FS_I(inode);
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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 error;
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switch (type) {
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case ACL_TYPE_ACCESS:
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name_index = F2FS_XATTR_INDEX_POSIX_ACL_ACCESS;
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if (acl) {
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error = posix_acl_equiv_mode(acl, &inode->i_mode);
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if (error < 0)
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return error;
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set_acl_inode(fi, inode->i_mode);
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if (error == 0)
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acl = NULL;
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}
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break;
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case ACL_TYPE_DEFAULT:
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name_index = F2FS_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 = f2fs_acl_to_disk(acl, &size);
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if (IS_ERR(value)) {
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clear_inode_flag(fi, FI_ACL_MODE);
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return (int)PTR_ERR(value);
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}
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}
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error = f2fs_setxattr(inode, name_index, "", value, size, ipage, 0);
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kfree(value);
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if (!error)
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set_cached_acl(inode, type, acl);
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clear_inode_flag(fi, FI_ACL_MODE);
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return error;
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}
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int f2fs_set_acl(struct inode *inode, struct posix_acl *acl, int type)
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{
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return __f2fs_set_acl(inode, type, acl, NULL);
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}
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/*
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* Most part of f2fs_acl_clone, f2fs_acl_create_masq, f2fs_acl_create
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* are copied from posix_acl.c
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*/
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static struct posix_acl *f2fs_acl_clone(const struct posix_acl *acl,
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gfp_t flags)
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{
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struct posix_acl *clone = NULL;
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if (acl) {
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int size = sizeof(struct posix_acl) + acl->a_count *
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sizeof(struct posix_acl_entry);
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clone = kmemdup(acl, size, flags);
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if (clone)
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atomic_set(&clone->a_refcount, 1);
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}
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return clone;
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}
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static int f2fs_acl_create_masq(struct posix_acl *acl, umode_t *mode_p)
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{
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struct posix_acl_entry *pa, *pe;
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struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL;
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umode_t mode = *mode_p;
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int not_equiv = 0;
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/* assert(atomic_read(acl->a_refcount) == 1); */
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FOREACH_ACL_ENTRY(pa, acl, pe) {
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switch(pa->e_tag) {
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case ACL_USER_OBJ:
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pa->e_perm &= (mode >> 6) | ~S_IRWXO;
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mode &= (pa->e_perm << 6) | ~S_IRWXU;
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break;
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case ACL_USER:
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case ACL_GROUP:
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not_equiv = 1;
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break;
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case ACL_GROUP_OBJ:
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group_obj = pa;
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break;
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case ACL_OTHER:
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pa->e_perm &= mode | ~S_IRWXO;
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mode &= pa->e_perm | ~S_IRWXO;
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break;
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case ACL_MASK:
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mask_obj = pa;
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not_equiv = 1;
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break;
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default:
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return -EIO;
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}
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}
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if (mask_obj) {
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mask_obj->e_perm &= (mode >> 3) | ~S_IRWXO;
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mode &= (mask_obj->e_perm << 3) | ~S_IRWXG;
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} else {
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if (!group_obj)
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return -EIO;
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group_obj->e_perm &= (mode >> 3) | ~S_IRWXO;
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mode &= (group_obj->e_perm << 3) | ~S_IRWXG;
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}
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*mode_p = (*mode_p & ~S_IRWXUGO) | mode;
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return not_equiv;
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}
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static int f2fs_acl_create(struct inode *dir, umode_t *mode,
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struct posix_acl **default_acl, struct posix_acl **acl,
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struct page *dpage)
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{
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struct posix_acl *p;
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struct posix_acl *clone;
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int ret;
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*acl = NULL;
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*default_acl = NULL;
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if (S_ISLNK(*mode) || !IS_POSIXACL(dir))
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return 0;
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p = __f2fs_get_acl(dir, ACL_TYPE_DEFAULT, dpage);
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if (!p || p == ERR_PTR(-EOPNOTSUPP)) {
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*mode &= ~current_umask();
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return 0;
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}
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if (IS_ERR(p))
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return PTR_ERR(p);
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clone = f2fs_acl_clone(p, GFP_NOFS);
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if (!clone)
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goto no_mem;
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ret = f2fs_acl_create_masq(clone, mode);
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if (ret < 0)
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goto no_mem_clone;
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if (ret == 0)
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posix_acl_release(clone);
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else
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*acl = clone;
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if (!S_ISDIR(*mode))
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posix_acl_release(p);
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else
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*default_acl = p;
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return 0;
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no_mem_clone:
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posix_acl_release(clone);
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no_mem:
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posix_acl_release(p);
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return -ENOMEM;
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}
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int f2fs_init_acl(struct inode *inode, struct inode *dir, struct page *ipage,
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struct page *dpage)
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{
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struct posix_acl *default_acl = NULL, *acl = NULL;
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int error = 0;
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error = f2fs_acl_create(dir, &inode->i_mode, &default_acl, &acl, dpage);
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if (error)
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return error;
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if (default_acl) {
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error = __f2fs_set_acl(inode, ACL_TYPE_DEFAULT, default_acl,
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ipage);
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posix_acl_release(default_acl);
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}
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if (acl) {
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if (!error)
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error = __f2fs_set_acl(inode, ACL_TYPE_ACCESS, acl,
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ipage);
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posix_acl_release(acl);
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}
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return error;
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}
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