On 8/19/21 2:33 PM, Gao Xiang wrote:
> Add runtime support for chunk-based uncompressed files
> described in the previous patch.
>
> Reviewed-by: Liu Bo <[email protected]>
> Signed-off-by: Gao Xiang <[email protected]>
> ---
> 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);
Better to add braces for if/else.
Thanks,
Joseph
> 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;
>
