Re: [PATCH] f2fs: add a max block count for f2fs_map_blocks

[Chao Yu <chao2.yu@samsung.com>]

Hi,

> -----Original Message-----
> From: Yunlei He [mailto:heyunlei@huawei.com]
> Sent: Friday, December 25, 2015 4:48 PM
> To: linux-f2fs-devel@lists.sourceforge.net; jaegeuk@kernel.org; chao2.yu@samsung.com
> Cc: bintian.wang@huawei.com; Yunlei He; Xue Liu
> Subject: [PATCH] f2fs: add a max block count for f2fs_map_blocks
> 
> This patch adds a max block count for f2fs_map_blocks

Maximum file size should be limited by sb->s_maxbytes which was inited
in max_file_size(), so logical block index should not exceed the value
calculated with maxbytes, why would we limit logical block index with
another value?

Thanks,

> 
> Signed-off-by: Yunlei He <heyunlei@huawei.com>
> Signed-off-by: Xue Liu <liuxueliu.liu@huawei.com>
> ---
>  fs/f2fs/data.c | 4 ++++
>  fs/f2fs/f2fs.h | 3 +++
>  2 files changed, 7 insertions(+)
> 
> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> index e34b1bd..2a16c867 100644
> --- a/fs/f2fs/data.c
> +++ b/fs/f2fs/data.c
> @@ -578,6 +578,10 @@ int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map,
>  	map->m_len = 0;
>  	map->m_flags = 0;
> 
> +	/* We can handle the block number less than F2FS_MAX_BLOCKS */
> +	if (unlikely(map->m_lblk >= F2FS_MAX_BLOCKS))
> +		return -EUCLEAN;
> +
>  	/* it only supports block size == page size */
>  	pgofs =	(pgoff_t)map->m_lblk;
> 
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index 19beabe..911c99b 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -331,6 +331,9 @@ enum {
> 
>  #define F2FS_LINK_MAX	0xffffffff	/* maximum link count per file */
> 
> +
> +#define F2FS_MAX_BLOCKS 0x3F015AFF      /* maximum block count per file */
> +
>  #define MAX_DIR_RA_PAGES	4	/* maximum ra pages of dir */
> 
>  /* vector size for gang look-up from extent cache that consists of radix tree */
> --
> 1.9.1



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