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![Gao Xiang](/assets/img/avatar_default.png)
There is no need to '#if CONFIG_EROFS_FS_XATTR' in xattr.c, let's remove it. Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Gao Xiang <gaoxiang25@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
577 lines
13 KiB
C
577 lines
13 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* linux/drivers/staging/erofs/xattr.c
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*
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* Copyright (C) 2017-2018 HUAWEI, Inc.
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* http://www.huawei.com/
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* Created by Gao Xiang <gaoxiang25@huawei.com>
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file COPYING in the main directory of the Linux
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* distribution for more details.
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*/
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#include <linux/security.h>
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#include "xattr.h"
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struct xattr_iter {
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struct super_block *sb;
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struct page *page;
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void *kaddr;
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erofs_blk_t blkaddr;
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unsigned ofs;
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};
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static inline void xattr_iter_end(struct xattr_iter *it, bool atomic)
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{
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/* only init_inode_xattrs use non-atomic once */
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if (unlikely(!atomic))
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kunmap(it->page);
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else
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kunmap_atomic(it->kaddr);
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unlock_page(it->page);
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put_page(it->page);
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}
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static void init_inode_xattrs(struct inode *inode)
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{
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struct xattr_iter it;
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unsigned i;
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struct erofs_xattr_ibody_header *ih;
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struct erofs_sb_info *sbi;
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struct erofs_vnode *vi;
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bool atomic_map;
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if (likely(inode_has_inited_xattr(inode)))
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return;
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vi = EROFS_V(inode);
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BUG_ON(!vi->xattr_isize);
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sbi = EROFS_I_SB(inode);
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it.blkaddr = erofs_blknr(iloc(sbi, vi->nid) + vi->inode_isize);
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it.ofs = erofs_blkoff(iloc(sbi, vi->nid) + vi->inode_isize);
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it.page = erofs_get_inline_page(inode, it.blkaddr);
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BUG_ON(IS_ERR(it.page));
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/* read in shared xattr array (non-atomic, see kmalloc below) */
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it.kaddr = kmap(it.page);
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atomic_map = false;
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ih = (struct erofs_xattr_ibody_header *)(it.kaddr + it.ofs);
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vi->xattr_shared_count = ih->h_shared_count;
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vi->xattr_shared_xattrs = (unsigned *)kmalloc_array(
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vi->xattr_shared_count, sizeof(unsigned),
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GFP_KERNEL | __GFP_NOFAIL);
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/* let's skip ibody header */
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it.ofs += sizeof(struct erofs_xattr_ibody_header);
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for (i = 0; i < vi->xattr_shared_count; ++i) {
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if (unlikely(it.ofs >= EROFS_BLKSIZ)) {
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/* cannot be unaligned */
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BUG_ON(it.ofs != EROFS_BLKSIZ);
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xattr_iter_end(&it, atomic_map);
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it.page = erofs_get_meta_page(inode->i_sb,
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++it.blkaddr, S_ISDIR(inode->i_mode));
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BUG_ON(IS_ERR(it.page));
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it.kaddr = kmap_atomic(it.page);
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atomic_map = true;
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it.ofs = 0;
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}
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vi->xattr_shared_xattrs[i] =
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le32_to_cpu(*(__le32 *)(it.kaddr + it.ofs));
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it.ofs += sizeof(__le32);
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}
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xattr_iter_end(&it, atomic_map);
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inode_set_inited_xattr(inode);
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}
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struct xattr_iter_handlers {
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int (*entry)(struct xattr_iter *, struct erofs_xattr_entry *);
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int (*name)(struct xattr_iter *, unsigned, char *, unsigned);
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int (*alloc_buffer)(struct xattr_iter *, unsigned);
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void (*value)(struct xattr_iter *, unsigned, char *, unsigned);
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};
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static void xattr_iter_fixup(struct xattr_iter *it)
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{
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if (unlikely(it->ofs >= EROFS_BLKSIZ)) {
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xattr_iter_end(it, true);
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it->blkaddr += erofs_blknr(it->ofs);
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it->page = erofs_get_meta_page(it->sb, it->blkaddr, false);
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BUG_ON(IS_ERR(it->page));
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it->kaddr = kmap_atomic(it->page);
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it->ofs = erofs_blkoff(it->ofs);
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}
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}
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static int inline_xattr_iter_begin(struct xattr_iter *it,
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struct inode *inode)
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{
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struct erofs_vnode *const vi = EROFS_V(inode);
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struct erofs_sb_info *const sbi = EROFS_SB(inode->i_sb);
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unsigned xattr_header_sz, inline_xattr_ofs;
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xattr_header_sz = inlinexattr_header_size(inode);
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if (unlikely(xattr_header_sz >= vi->xattr_isize)) {
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BUG_ON(xattr_header_sz > vi->xattr_isize);
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return -ENOATTR;
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}
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inline_xattr_ofs = vi->inode_isize + xattr_header_sz;
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it->blkaddr = erofs_blknr(iloc(sbi, vi->nid) + inline_xattr_ofs);
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it->ofs = erofs_blkoff(iloc(sbi, vi->nid) + inline_xattr_ofs);
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it->page = erofs_get_inline_page(inode, it->blkaddr);
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BUG_ON(IS_ERR(it->page));
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it->kaddr = kmap_atomic(it->page);
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return vi->xattr_isize - xattr_header_sz;
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}
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static int xattr_foreach(struct xattr_iter *it,
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struct xattr_iter_handlers *op, unsigned *tlimit)
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{
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struct erofs_xattr_entry entry;
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unsigned value_sz, processed, slice;
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int err;
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/* 0. fixup blkaddr, ofs, ipage */
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xattr_iter_fixup(it);
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/*
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* 1. read xattr entry to the memory,
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* since we do EROFS_XATTR_ALIGN
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* therefore entry should be in the page
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*/
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entry = *(struct erofs_xattr_entry *)(it->kaddr + it->ofs);
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if (tlimit != NULL) {
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unsigned entry_sz = EROFS_XATTR_ENTRY_SIZE(&entry);
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BUG_ON(*tlimit < entry_sz);
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*tlimit -= entry_sz;
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}
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it->ofs += sizeof(struct erofs_xattr_entry);
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value_sz = le16_to_cpu(entry.e_value_size);
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/* handle entry */
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err = op->entry(it, &entry);
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if (err) {
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it->ofs += entry.e_name_len + value_sz;
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goto out;
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}
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/* 2. handle xattr name (ofs will finally be at the end of name) */
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processed = 0;
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while (processed < entry.e_name_len) {
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if (it->ofs >= EROFS_BLKSIZ) {
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BUG_ON(it->ofs > EROFS_BLKSIZ);
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xattr_iter_fixup(it);
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it->ofs = 0;
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}
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slice = min_t(unsigned, PAGE_SIZE - it->ofs,
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entry.e_name_len - processed);
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/* handle name */
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err = op->name(it, processed, it->kaddr + it->ofs, slice);
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if (err) {
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it->ofs += entry.e_name_len - processed + value_sz;
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goto out;
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}
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it->ofs += slice;
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processed += slice;
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}
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/* 3. handle xattr value */
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processed = 0;
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if (op->alloc_buffer != NULL) {
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err = op->alloc_buffer(it, value_sz);
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if (err) {
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it->ofs += value_sz;
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goto out;
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}
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}
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while (processed < value_sz) {
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if (it->ofs >= EROFS_BLKSIZ) {
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BUG_ON(it->ofs > EROFS_BLKSIZ);
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xattr_iter_fixup(it);
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it->ofs = 0;
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}
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slice = min_t(unsigned, PAGE_SIZE - it->ofs,
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value_sz - processed);
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op->value(it, processed, it->kaddr + it->ofs, slice);
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it->ofs += slice;
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processed += slice;
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}
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out:
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/* we assume that ofs is aligned with 4 bytes */
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it->ofs = EROFS_XATTR_ALIGN(it->ofs);
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return err;
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}
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struct getxattr_iter {
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struct xattr_iter it;
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char *buffer;
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int buffer_size, index;
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struct qstr name;
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};
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static int xattr_entrymatch(struct xattr_iter *_it,
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struct erofs_xattr_entry *entry)
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{
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struct getxattr_iter *it = container_of(_it, struct getxattr_iter, it);
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return (it->index != entry->e_name_index ||
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it->name.len != entry->e_name_len) ? -ENOATTR : 0;
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}
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static int xattr_namematch(struct xattr_iter *_it,
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unsigned processed, char *buf, unsigned len)
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{
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struct getxattr_iter *it = container_of(_it, struct getxattr_iter, it);
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return memcmp(buf, it->name.name + processed, len) ? -ENOATTR : 0;
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}
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static int xattr_checkbuffer(struct xattr_iter *_it,
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unsigned value_sz)
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{
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struct getxattr_iter *it = container_of(_it, struct getxattr_iter, it);
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int err = it->buffer_size < value_sz ? -ERANGE : 0;
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it->buffer_size = value_sz;
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return it->buffer == NULL ? 1 : err;
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}
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static void xattr_copyvalue(struct xattr_iter *_it,
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unsigned processed, char *buf, unsigned len)
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{
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struct getxattr_iter *it = container_of(_it, struct getxattr_iter, it);
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memcpy(it->buffer + processed, buf, len);
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}
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static struct xattr_iter_handlers find_xattr_handlers = {
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.entry = xattr_entrymatch,
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.name = xattr_namematch,
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.alloc_buffer = xattr_checkbuffer,
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.value = xattr_copyvalue
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};
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static int inline_getxattr(struct inode *inode, struct getxattr_iter *it)
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{
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int ret;
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unsigned remaining;
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ret = inline_xattr_iter_begin(&it->it, inode);
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if (ret < 0)
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return ret;
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remaining = ret;
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while (remaining) {
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if ((ret = xattr_foreach(&it->it,
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&find_xattr_handlers, &remaining)) >= 0)
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break;
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}
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xattr_iter_end(&it->it, true);
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return ret < 0 ? ret : it->buffer_size;
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}
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static int shared_getxattr(struct inode *inode, struct getxattr_iter *it)
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{
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struct erofs_vnode *const vi = EROFS_V(inode);
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struct erofs_sb_info *const sbi = EROFS_SB(inode->i_sb);
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unsigned i;
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int ret = -ENOATTR;
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for (i = 0; i < vi->xattr_shared_count; ++i) {
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erofs_blk_t blkaddr =
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xattrblock_addr(sbi, vi->xattr_shared_xattrs[i]);
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it->it.ofs = xattrblock_offset(sbi, vi->xattr_shared_xattrs[i]);
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if (!i || blkaddr != it->it.blkaddr) {
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if (i)
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xattr_iter_end(&it->it, true);
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it->it.page = erofs_get_meta_page(inode->i_sb,
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blkaddr, false);
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BUG_ON(IS_ERR(it->it.page));
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it->it.kaddr = kmap_atomic(it->it.page);
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it->it.blkaddr = blkaddr;
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}
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if ((ret = xattr_foreach(&it->it,
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&find_xattr_handlers, NULL)) >= 0)
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break;
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}
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if (vi->xattr_shared_count)
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xattr_iter_end(&it->it, true);
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return ret < 0 ? ret : it->buffer_size;
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}
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static bool erofs_xattr_user_list(struct dentry *dentry)
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{
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return test_opt(EROFS_SB(dentry->d_sb), XATTR_USER);
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}
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static bool erofs_xattr_trusted_list(struct dentry *dentry)
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{
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return capable(CAP_SYS_ADMIN);
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}
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int erofs_getxattr(struct inode *inode, int index,
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const char *name,
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void *buffer, size_t buffer_size)
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{
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int ret;
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struct getxattr_iter it;
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if (unlikely(name == NULL))
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return -EINVAL;
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init_inode_xattrs(inode);
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it.index = index;
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it.name.len = strlen(name);
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if (it.name.len > EROFS_NAME_LEN)
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return -ERANGE;
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it.name.name = name;
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it.buffer = buffer;
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it.buffer_size = buffer_size;
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it.it.sb = inode->i_sb;
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ret = inline_getxattr(inode, &it);
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if (ret == -ENOATTR)
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ret = shared_getxattr(inode, &it);
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return ret;
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}
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static int erofs_xattr_generic_get(const struct xattr_handler *handler,
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struct dentry *unused, struct inode *inode,
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const char *name, void *buffer, size_t size)
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{
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struct erofs_vnode *const vi = EROFS_V(inode);
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struct erofs_sb_info *const sbi = EROFS_I_SB(inode);
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switch (handler->flags) {
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case EROFS_XATTR_INDEX_USER:
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if (!test_opt(sbi, XATTR_USER))
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return -EOPNOTSUPP;
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break;
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case EROFS_XATTR_INDEX_TRUSTED:
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if (!capable(CAP_SYS_ADMIN))
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return -EPERM;
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break;
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case EROFS_XATTR_INDEX_SECURITY:
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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 (!vi->xattr_isize)
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return -ENOATTR;
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return erofs_getxattr(inode, handler->flags, name, buffer, size);
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}
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const struct xattr_handler erofs_xattr_user_handler = {
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.prefix = XATTR_USER_PREFIX,
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.flags = EROFS_XATTR_INDEX_USER,
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.list = erofs_xattr_user_list,
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.get = erofs_xattr_generic_get,
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};
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const struct xattr_handler erofs_xattr_trusted_handler = {
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.prefix = XATTR_TRUSTED_PREFIX,
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.flags = EROFS_XATTR_INDEX_TRUSTED,
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.list = erofs_xattr_trusted_list,
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.get = erofs_xattr_generic_get,
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};
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#ifdef CONFIG_EROFS_FS_SECURITY
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const struct xattr_handler __maybe_unused erofs_xattr_security_handler = {
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.prefix = XATTR_SECURITY_PREFIX,
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.flags = EROFS_XATTR_INDEX_SECURITY,
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.get = erofs_xattr_generic_get,
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};
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#endif
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const struct xattr_handler *erofs_xattr_handlers[] = {
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&erofs_xattr_user_handler,
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#ifdef CONFIG_EROFS_FS_POSIX_ACL
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&posix_acl_access_xattr_handler,
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&posix_acl_default_xattr_handler,
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#endif
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&erofs_xattr_trusted_handler,
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#ifdef CONFIG_EROFS_FS_SECURITY
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&erofs_xattr_security_handler,
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#endif
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NULL,
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};
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struct listxattr_iter {
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struct xattr_iter it;
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struct dentry *dentry;
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char *buffer;
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int buffer_size, buffer_ofs;
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};
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static int xattr_entrylist(struct xattr_iter *_it,
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struct erofs_xattr_entry *entry)
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{
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struct listxattr_iter *it =
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container_of(_it, struct listxattr_iter, it);
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unsigned prefix_len;
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const char *prefix;
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const struct xattr_handler *h =
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erofs_xattr_handler(entry->e_name_index);
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if (h == NULL || (h->list != NULL && !h->list(it->dentry)))
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return 1;
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/* Note that at least one of 'prefix' and 'name' should be non-NULL */
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prefix = h->prefix != NULL ? h->prefix : h->name;
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prefix_len = strlen(prefix);
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if (it->buffer == NULL) {
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it->buffer_ofs += prefix_len + entry->e_name_len + 1;
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return 1;
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}
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if (it->buffer_ofs + prefix_len
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+ entry->e_name_len + 1 > it->buffer_size)
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return -ERANGE;
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memcpy(it->buffer + it->buffer_ofs, prefix, prefix_len);
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it->buffer_ofs += prefix_len;
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return 0;
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}
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static int xattr_namelist(struct xattr_iter *_it,
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unsigned processed, char *buf, unsigned len)
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{
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struct listxattr_iter *it =
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container_of(_it, struct listxattr_iter, it);
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memcpy(it->buffer + it->buffer_ofs, buf, len);
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it->buffer_ofs += len;
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return 0;
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}
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static int xattr_skipvalue(struct xattr_iter *_it,
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unsigned value_sz)
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{
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struct listxattr_iter *it =
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container_of(_it, struct listxattr_iter, it);
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it->buffer[it->buffer_ofs++] = '\0';
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return 1;
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}
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static struct xattr_iter_handlers list_xattr_handlers = {
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.entry = xattr_entrylist,
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.name = xattr_namelist,
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.alloc_buffer = xattr_skipvalue,
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.value = NULL
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};
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static int inline_listxattr(struct listxattr_iter *it)
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{
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int ret;
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unsigned remaining;
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ret = inline_xattr_iter_begin(&it->it, d_inode(it->dentry));
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
remaining = ret;
|
|
while (remaining) {
|
|
if ((ret = xattr_foreach(&it->it,
|
|
&list_xattr_handlers, &remaining)) < 0)
|
|
break;
|
|
}
|
|
xattr_iter_end(&it->it, true);
|
|
return ret < 0 ? ret : it->buffer_ofs;
|
|
}
|
|
|
|
static int shared_listxattr(struct listxattr_iter *it)
|
|
{
|
|
struct inode *const inode = d_inode(it->dentry);
|
|
struct erofs_vnode *const vi = EROFS_V(inode);
|
|
struct erofs_sb_info *const sbi = EROFS_I_SB(inode);
|
|
unsigned i;
|
|
int ret = 0;
|
|
|
|
for (i = 0; i < vi->xattr_shared_count; ++i) {
|
|
erofs_blk_t blkaddr =
|
|
xattrblock_addr(sbi, vi->xattr_shared_xattrs[i]);
|
|
|
|
it->it.ofs = xattrblock_offset(sbi, vi->xattr_shared_xattrs[i]);
|
|
if (!i || blkaddr != it->it.blkaddr) {
|
|
if (i)
|
|
xattr_iter_end(&it->it, true);
|
|
|
|
it->it.page = erofs_get_meta_page(inode->i_sb,
|
|
blkaddr, false);
|
|
BUG_ON(IS_ERR(it->it.page));
|
|
it->it.kaddr = kmap_atomic(it->it.page);
|
|
it->it.blkaddr = blkaddr;
|
|
}
|
|
|
|
if ((ret = xattr_foreach(&it->it,
|
|
&list_xattr_handlers, NULL)) < 0)
|
|
break;
|
|
}
|
|
if (vi->xattr_shared_count)
|
|
xattr_iter_end(&it->it, true);
|
|
|
|
return ret < 0 ? ret : it->buffer_ofs;
|
|
}
|
|
|
|
ssize_t erofs_listxattr(struct dentry *dentry,
|
|
char *buffer, size_t buffer_size)
|
|
{
|
|
int ret;
|
|
struct listxattr_iter it;
|
|
|
|
init_inode_xattrs(d_inode(dentry));
|
|
|
|
it.dentry = dentry;
|
|
it.buffer = buffer;
|
|
it.buffer_size = buffer_size;
|
|
it.buffer_ofs = 0;
|
|
|
|
it.it.sb = dentry->d_sb;
|
|
|
|
ret = inline_listxattr(&it);
|
|
if (ret < 0 && ret != -ENOATTR)
|
|
return ret;
|
|
return shared_listxattr(&it);
|
|
}
|
|
|