[PATCH v2 2/2] erofs: support reading chunk-based uncompressed files
Gao Xiang
hsiangkao at linux.alibaba.com
Thu Aug 19 16:33:10 AEST 2021
Add runtime support for chunk-based uncompressed files
described in the previous patch.
Reviewed-by: Liu Bo <bo.liu at linux.alibaba.com>
Signed-off-by: Gao Xiang <hsiangkao at linux.alibaba.com>
---
changes since v1:
- use le16_to_cpu instead of __le16_to_cpu pointed out by Chao.
fs/erofs/data.c | 90 ++++++++++++++++++++++++++++++++++++++++-----
fs/erofs/inode.c | 18 ++++++++-
fs/erofs/internal.h | 5 +++
3 files changed, 102 insertions(+), 11 deletions(-)
diff --git a/fs/erofs/data.c b/fs/erofs/data.c
index 09c46fbdb9b2..ee9a33485313 100644
--- a/fs/erofs/data.c
+++ b/fs/erofs/data.c
@@ -2,6 +2,7 @@
/*
* Copyright (C) 2017-2018 HUAWEI, Inc.
* https://www.huawei.com/
+ * Copyright (C) 2021, Alibaba Cloud
*/
#include "internal.h"
#include <linux/prefetch.h>
@@ -36,13 +37,6 @@ static int erofs_map_blocks_flatmode(struct inode *inode,
nblocks = DIV_ROUND_UP(inode->i_size, PAGE_SIZE);
lastblk = nblocks - tailendpacking;
- if (offset >= inode->i_size) {
- /* leave out-of-bound access unmapped */
- map->m_flags = 0;
- map->m_plen = 0;
- goto out;
- }
-
/* there is no hole in flatmode */
map->m_flags = EROFS_MAP_MAPPED;
@@ -77,14 +71,90 @@ static int erofs_map_blocks_flatmode(struct inode *inode,
goto err_out;
}
-out:
map->m_llen = map->m_plen;
-
err_out:
trace_erofs_map_blocks_flatmode_exit(inode, map, flags, 0);
return err;
}
+static int erofs_map_blocks(struct inode *inode,
+ struct erofs_map_blocks *map, int flags)
+{
+ struct super_block *sb = inode->i_sb;
+ struct erofs_inode *vi = EROFS_I(inode);
+ struct erofs_inode_chunk_index *idx;
+ struct page *page;
+ u64 chunknr;
+ unsigned int unit;
+ erofs_off_t pos;
+ int err = 0;
+
+ if (map->m_la >= inode->i_size) {
+ /* leave out-of-bound access unmapped */
+ map->m_flags = 0;
+ map->m_plen = 0;
+ goto out;
+ }
+
+ if (vi->datalayout != EROFS_INODE_CHUNK_BASED)
+ return erofs_map_blocks_flatmode(inode, map, flags);
+
+ if (vi->chunkformat & EROFS_CHUNK_FORMAT_INDEXES)
+ unit = sizeof(*idx); /* chunk index */
+ else
+ unit = 4; /* block map */
+
+ chunknr = map->m_la >> vi->chunkbits;
+ pos = ALIGN(iloc(EROFS_SB(sb), vi->nid) + vi->inode_isize +
+ vi->xattr_isize, unit) + unit * chunknr;
+
+ page = erofs_get_meta_page(inode->i_sb, erofs_blknr(pos));
+ if (IS_ERR(page))
+ return PTR_ERR(page);
+
+ map->m_la = chunknr << vi->chunkbits;
+ map->m_plen = min_t(erofs_off_t, 1UL << vi->chunkbits,
+ roundup(inode->i_size - map->m_la, EROFS_BLKSIZ));
+
+ /* handle block map */
+ if (!(vi->chunkformat & EROFS_CHUNK_FORMAT_INDEXES)) {
+ __le32 *blkaddr = page_address(page) + erofs_blkoff(pos);
+
+ if (le32_to_cpu(*blkaddr) == EROFS_NULL_ADDR) {
+ map->m_flags = 0;
+ } else {
+ map->m_pa = blknr_to_addr(le32_to_cpu(*blkaddr));
+ map->m_flags = EROFS_MAP_MAPPED;
+ }
+ goto out_unlock;
+ }
+ /* parse chunk indexes */
+ idx = page_address(page) + erofs_blkoff(pos);
+ switch (le32_to_cpu(idx->blkaddr)) {
+ case EROFS_NULL_ADDR:
+ map->m_flags = 0;
+ break;
+ default:
+ /* only one device is supported for now */
+ if (idx->device_id) {
+ erofs_err(sb, "invalid device id %u @ %llu for nid %llu",
+ le32_to_cpu(idx->device_id),
+ chunknr, vi->nid);
+ err = -EFSCORRUPTED;
+ goto out_unlock;
+ }
+ map->m_pa = blknr_to_addr(le32_to_cpu(idx->blkaddr));
+ map->m_flags = EROFS_MAP_MAPPED;
+ break;
+ }
+out_unlock:
+ unlock_page(page);
+ put_page(page);
+out:
+ map->m_llen = map->m_plen;
+ return err;
+}
+
static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
unsigned int flags, struct iomap *iomap, struct iomap *srcmap)
{
@@ -94,7 +164,7 @@ static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
map.m_la = offset;
map.m_llen = length;
- ret = erofs_map_blocks_flatmode(inode, &map, EROFS_GET_BLOCKS_RAW);
+ ret = erofs_map_blocks(inode, &map, EROFS_GET_BLOCKS_RAW);
if (ret < 0)
return ret;
diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
index d13e0709599c..4408929bd6f5 100644
--- a/fs/erofs/inode.c
+++ b/fs/erofs/inode.c
@@ -2,6 +2,7 @@
/*
* Copyright (C) 2017-2018 HUAWEI, Inc.
* https://www.huawei.com/
+ * Copyright (C) 2021, Alibaba Cloud
*/
#include "xattr.h"
@@ -122,7 +123,9 @@ static struct page *erofs_read_inode(struct inode *inode,
/* total blocks for compressed files */
if (erofs_inode_is_data_compressed(vi->datalayout))
nblks = le32_to_cpu(die->i_u.compressed_blocks);
-
+ else if (vi->datalayout == EROFS_INODE_CHUNK_BASED)
+ /* fill chunked inode summary info */
+ vi->chunkformat = le16_to_cpu(die->i_u.c.format);
kfree(copied);
break;
case EROFS_INODE_LAYOUT_COMPACT:
@@ -160,6 +163,8 @@ static struct page *erofs_read_inode(struct inode *inode,
inode->i_size = le32_to_cpu(dic->i_size);
if (erofs_inode_is_data_compressed(vi->datalayout))
nblks = le32_to_cpu(dic->i_u.compressed_blocks);
+ else if (vi->datalayout == EROFS_INODE_CHUNK_BASED)
+ vi->chunkformat = le16_to_cpu(dic->i_u.c.format);
break;
default:
erofs_err(inode->i_sb,
@@ -169,6 +174,17 @@ static struct page *erofs_read_inode(struct inode *inode,
goto err_out;
}
+ if (vi->datalayout == EROFS_INODE_CHUNK_BASED) {
+ if (!(vi->chunkformat & EROFS_CHUNK_FORMAT_ALL)) {
+ erofs_err(inode->i_sb,
+ "unsupported chunk format %x of nid %llu",
+ vi->chunkformat, vi->nid);
+ err = -EOPNOTSUPP;
+ goto err_out;
+ }
+ vi->chunkbits = LOG_BLOCK_SIZE +
+ (vi->chunkformat & EROFS_CHUNK_FORMAT_BLKBITS_MASK);
+ }
inode->i_mtime.tv_sec = inode->i_ctime.tv_sec;
inode->i_atime.tv_sec = inode->i_ctime.tv_sec;
inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec;
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index 91089ab8a816..9524e155b38f 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -2,6 +2,7 @@
/*
* Copyright (C) 2017-2018 HUAWEI, Inc.
* https://www.huawei.com/
+ * Copyright (C) 2021, Alibaba Cloud
*/
#ifndef __EROFS_INTERNAL_H
#define __EROFS_INTERNAL_H
@@ -261,6 +262,10 @@ struct erofs_inode {
union {
erofs_blk_t raw_blkaddr;
+ struct {
+ unsigned short chunkformat;
+ unsigned char chunkbits;
+ };
#ifdef CONFIG_EROFS_FS_ZIP
struct {
unsigned short z_advise;
--
2.24.4
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