On Wed, Apr 06, 2022 at 03:56:09PM +0800, Jeffle Xu wrote:
> Implement the data plane of reading data from data blobs over fscache
> for non-inline layout.
>
> Signed-off-by: Jeffle Xu <jeffl...@linux.alibaba.com>
> ---
> fs/erofs/fscache.c | 52 +++++++++++++++++++++++++++++++++++++++++++++
> fs/erofs/inode.c | 5 +++++
> fs/erofs/internal.h | 2 ++
> 3 files changed, 59 insertions(+)
>
> diff --git a/fs/erofs/fscache.c b/fs/erofs/fscache.c
> index 158cc273f8fb..65de1c754e80 100644
> --- a/fs/erofs/fscache.c
> +++ b/fs/erofs/fscache.c
> @@ -60,10 +60,62 @@ static int erofs_fscache_meta_readpage(struct file *data,
> struct page *page)
> return ret;
> }
>
> +static int erofs_fscache_readpage(struct file *file, struct page *page)
> +{
> + struct folio *folio = page_folio(page);
> + struct inode *inode = folio_file_mapping(folio)->host;
> + struct super_block *sb = inode->i_sb;
> + struct erofs_map_blocks map;
> + struct erofs_map_dev mdev;
> + erofs_off_t pos;
> + loff_t pstart;
> + int ret = 0;
> +
> + DBG_BUGON(folio_size(folio) != EROFS_BLKSIZ);
> +
> + pos = folio_pos(folio);
> + map.m_la = pos;
> +
> + ret = erofs_map_blocks(inode, &map, EROFS_GET_BLOCKS_RAW);
> + if (ret)
> + goto out_unlock;
> +
> + if (!(map.m_flags & EROFS_MAP_MAPPED)) {
> + folio_zero_range(folio, 0, folio_size(folio));
> + goto out_uptodate;
> + }
> +
> + /* no-inline readpage */
> + mdev = (struct erofs_map_dev) {
> + .m_deviceid = map.m_deviceid,
> + .m_pa = map.m_pa,
> + };
> +
> + ret = erofs_map_dev(sb, &mdev);
> + if (ret)
> + goto out_unlock;
> +
> + pstart = mdev.m_pa + (pos - map.m_la);
> + ret = erofs_fscache_read_folios(mdev.m_fscache->cookie,
> + folio_file_mapping(folio), folio_pos(folio),
> + folio_size(folio), pstart);
> +
> +out_uptodate:
> + if (!ret)
> + folio_mark_uptodate(folio);
> +out_unlock:
> + folio_unlock(folio);
> + return ret;
> +}
> +
> static const struct address_space_operations erofs_fscache_meta_aops = {
> .readpage = erofs_fscache_meta_readpage,
> };
>
> +const struct address_space_operations erofs_fscache_access_aops = {
> + .readpage = erofs_fscache_readpage,
> +};
> +
> /*
> * Get the page cache of data blob at the index offset.
> * Return: up to date page on success, ERR_PTR() on failure.
> diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
> index e8b37ba5e9ad..88b51b5fb53f 100644
> --- a/fs/erofs/inode.c
> +++ b/fs/erofs/inode.c
> @@ -296,7 +296,12 @@ static int erofs_fill_inode(struct inode *inode, int
> isdir)
> err = z_erofs_fill_inode(inode);
> goto out_unlock;
> }
> +
unnecessary modification.
Otherwise looks good:
Reviewed-by: Gao Xiang <hsiang...@linux.alibaba.com>
Thanks,
Gao Xiang
> inode->i_mapping->a_ops = &erofs_raw_access_aops;
> +#ifdef CONFIG_EROFS_FS_ONDEMAND
> + if (erofs_is_fscache_mode(inode->i_sb))
> + inode->i_mapping->a_ops = &erofs_fscache_access_aops;
> +#endif
>
> out_unlock:
> erofs_put_metabuf(&buf);
> diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
> index e186051f0640..336d19647c96 100644
> --- a/fs/erofs/internal.h
> +++ b/fs/erofs/internal.h
> @@ -642,6 +642,8 @@ int erofs_fscache_register_cookie(struct super_block *sb,
> void erofs_fscache_unregister_cookie(struct erofs_fscache **fscache);
>
> struct folio *erofs_fscache_get_folio(struct super_block *sb, pgoff_t index);
> +
> +extern const struct address_space_operations erofs_fscache_access_aops;
> #else
> static inline int erofs_fscache_register_fs(struct super_block *sb) { return
> 0; }
> static inline void erofs_fscache_unregister_fs(struct super_block *sb) {}
> --
> 2.27.0
>
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