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Gao Xianggregkh
Gao Xiang
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gregkh
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staging: erofs: add inode operations
This adds core functions to get, read an inode. Signed-off-by: Miao Xie <miaoxie@huawei.com> Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Gao Xiang <gaoxiang25@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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‎drivers/staging/erofs/inode.c

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// SPDX-License-Identifier: GPL-2.0
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/*
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* linux/drivers/staging/erofs/inode.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 "internal.h"
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/* no locking */
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static int read_inode(struct inode *inode, void *data)
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{
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struct erofs_vnode *vi = EROFS_V(inode);
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struct erofs_inode_v1 *v1 = data;
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const unsigned advise = le16_to_cpu(v1->i_advise);
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vi->data_mapping_mode = __inode_data_mapping(advise);
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if (unlikely(vi->data_mapping_mode >= EROFS_INODE_LAYOUT_MAX)) {
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errln("unknown data mapping mode %u of nid %llu",
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vi->data_mapping_mode, vi->nid);
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DBG_BUGON(1);
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return -EIO;
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}
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if (__inode_version(advise) == EROFS_INODE_LAYOUT_V2) {
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struct erofs_inode_v2 *v2 = data;
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vi->inode_isize = sizeof(struct erofs_inode_v2);
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vi->xattr_isize = ondisk_xattr_ibody_size(v2->i_xattr_icount);
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vi->raw_blkaddr = le32_to_cpu(v2->i_u.raw_blkaddr);
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inode->i_mode = le16_to_cpu(v2->i_mode);
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i_uid_write(inode, le32_to_cpu(v2->i_uid));
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i_gid_write(inode, le32_to_cpu(v2->i_gid));
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set_nlink(inode, le32_to_cpu(v2->i_nlink));
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/* ns timestamp */
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inode->i_mtime.tv_sec = inode->i_ctime.tv_sec =
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le64_to_cpu(v2->i_ctime);
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inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec =
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le32_to_cpu(v2->i_ctime_nsec);
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inode->i_size = le64_to_cpu(v2->i_size);
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} else if (__inode_version(advise) == EROFS_INODE_LAYOUT_V1) {
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struct erofs_sb_info *sbi = EROFS_SB(inode->i_sb);
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vi->inode_isize = sizeof(struct erofs_inode_v1);
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vi->xattr_isize = ondisk_xattr_ibody_size(v1->i_xattr_icount);
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vi->raw_blkaddr = le32_to_cpu(v1->i_u.raw_blkaddr);
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inode->i_mode = le16_to_cpu(v1->i_mode);
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i_uid_write(inode, le16_to_cpu(v1->i_uid));
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i_gid_write(inode, le16_to_cpu(v1->i_gid));
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set_nlink(inode, le16_to_cpu(v1->i_nlink));
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/* use build time to derive all file time */
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inode->i_mtime.tv_sec = inode->i_ctime.tv_sec =
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sbi->build_time;
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inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec =
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sbi->build_time_nsec;
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inode->i_size = le32_to_cpu(v1->i_size);
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} else {
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errln("unsupported on-disk inode version %u of nid %llu",
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__inode_version(advise), vi->nid);
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DBG_BUGON(1);
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return -EIO;
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}
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/* measure inode.i_blocks as the generic filesystem */
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inode->i_blocks = ((inode->i_size - 1) >> 9) + 1;
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return 0;
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}
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/*
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* try_lock can be required since locking order is:
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* file data(fs_inode)
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* meta(bd_inode)
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* but the majority of the callers is "iget",
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* in that case we are pretty sure no deadlock since
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* no data operations exist. However I tend to
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* try_lock since it takes no much overhead and
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* will success immediately.
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*/
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static int fill_inline_data(struct inode *inode, void *data, unsigned m_pofs)
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{
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struct erofs_vnode *vi = EROFS_V(inode);
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int mode = vi->data_mapping_mode;
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DBG_BUGON(mode >= EROFS_INODE_LAYOUT_MAX);
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/* should be inode inline C */
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if (mode != EROFS_INODE_LAYOUT_INLINE)
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return 0;
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/* fast symlink (following ext4) */
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if (S_ISLNK(inode->i_mode) && inode->i_size < PAGE_SIZE) {
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char *lnk = kmalloc(inode->i_size + 1, GFP_KERNEL);
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if (unlikely(lnk == NULL))
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return -ENOMEM;
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m_pofs += vi->inode_isize + vi->xattr_isize;
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BUG_ON(m_pofs + inode->i_size > PAGE_SIZE);
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/* get in-page inline data */
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memcpy(lnk, data + m_pofs, inode->i_size);
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lnk[inode->i_size] = '\0';
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inode->i_link = lnk;
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set_inode_fast_symlink(inode);
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}
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return -EAGAIN;
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}
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static int fill_inode(struct inode *inode, int isdir)
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{
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struct erofs_sb_info *sbi = EROFS_SB(inode->i_sb);
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struct erofs_vnode *vi = EROFS_V(inode);
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struct page *page;
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void *data;
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int err;
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erofs_blk_t blkaddr;
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unsigned ofs;
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blkaddr = erofs_blknr(iloc(sbi, vi->nid));
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ofs = erofs_blkoff(iloc(sbi, vi->nid));
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debugln("%s, reading inode nid %llu at %u of blkaddr %u",
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__func__, vi->nid, ofs, blkaddr);
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page = erofs_get_meta_page(inode->i_sb, blkaddr, isdir);
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if (IS_ERR(page)) {
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errln("failed to get inode (nid: %llu) page, err %ld",
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vi->nid, PTR_ERR(page));
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return PTR_ERR(page);
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}
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BUG_ON(!PageUptodate(page));
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data = page_address(page);
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err = read_inode(inode, data + ofs);
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if (!err) {
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/* setup the new inode */
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if (S_ISREG(inode->i_mode)) {
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inode->i_fop = &generic_ro_fops;
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} else if (S_ISDIR(inode->i_mode)) {
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inode->i_op =
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&erofs_dir_iops;
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inode->i_fop = &erofs_dir_fops;
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} else if (S_ISLNK(inode->i_mode)) {
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/* by default, page_get_link is used for symlink */
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inode->i_op =
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&page_symlink_inode_operations;
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inode_nohighmem(inode);
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} else {
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err = -EIO;
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goto out_unlock;
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}
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if (is_inode_layout_compression(inode)) {
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err = -ENOTSUPP;
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goto out_unlock;
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}
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inode->i_mapping->a_ops = &erofs_raw_access_aops;
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/* fill last page if inline data is available */
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fill_inline_data(inode, data, ofs);
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}
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out_unlock:
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unlock_page(page);
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put_page(page);
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return err;
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}
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struct inode *erofs_iget(struct super_block *sb,
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erofs_nid_t nid, bool isdir)
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{
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struct inode *inode = iget_locked(sb, nid);
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if (unlikely(inode == NULL))
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return ERR_PTR(-ENOMEM);
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if (inode->i_state & I_NEW) {
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int err;
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struct erofs_vnode *vi = EROFS_V(inode);
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vi->nid = nid;
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err = fill_inode(inode, isdir);
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if (likely(!err))
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unlock_new_inode(inode);
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else {
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iget_failed(inode);
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inode = ERR_PTR(err);
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}
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}
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return inode;
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}
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