Re: [PATCH] f2fs: introduce max_file_blocks in sbi

[Jaegeuk Kim <jaegeuk@kernel.org>]

Hi Chao,

On Thu, Dec 31, 2015 at 02:35:37PM +0800, Chao Yu wrote:
> Introduce max_file_blocks in sbi to store max block index of file in f2fs,
> it could be used to avoid unneeded calculation of max block index in
> runtime.
> 
> Signed-off-by: Chao Yu <chao2.yu@samsung.com>
> ---
>  fs/f2fs/data.c  | 2 +-
>  fs/f2fs/f2fs.h  | 2 +-
>  fs/f2fs/super.c | 7 ++++---
>  3 files changed, 6 insertions(+), 5 deletions(-)
> 
> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> index 5a71017..73b7a8f 100644
> --- a/fs/f2fs/data.c
> +++ b/fs/f2fs/data.c
> @@ -762,7 +762,7 @@ static int get_data_block_bmap(struct inode *inode, sector_t iblock,
>  			struct buffer_head *bh_result, int create)
>  {
>  	/* Block number less than F2FS MAX BLOCKS */
> -	if (unlikely(iblock >= max_file_size(0)))
> +	if (unlikely(iblock >= F2FS_I_SB(inode)->max_file_blocks))
>  		return -EFBIG;
>  
>  	return __get_data_block(inode, iblock, bh_result, create,
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index 9ba6a09..520d8f2 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -786,6 +786,7 @@ struct f2fs_sb_info {
>  	unsigned int total_node_count;		/* total node block count */
>  	unsigned int total_valid_node_count;	/* valid node block count */
>  	unsigned int total_valid_inode_count;	/* valid inode count */
> +	unsigned int max_file_blocks;		/* max block index of file */

I found a overflow bug here and fixed this in my git.
This should be loff_t, otherwise it goes about 300 MB.

Thanks,


>  	int active_logs;			/* # of active logs */
>  	int dir_level;				/* directory level */
>  	int serialized_dio_pages;		/* serialized direct IO pages */
> @@ -1731,7 +1732,6 @@ static inline int f2fs_add_link(struct dentry *dentry, struct inode *inode)
>   * super.c
>   */
>  int f2fs_commit_super(struct f2fs_sb_info *, bool);
> -loff_t max_file_size(unsigned bits);
>  int f2fs_sync_fs(struct super_block *, int);
>  extern __printf(3, 4)
>  void f2fs_msg(struct super_block *, const char *, const char *, ...);
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index f474355..4e5bbd4 100644
> --- a/fs/f2fs/super.c
> +++ b/fs/f2fs/super.c
> @@ -909,7 +909,7 @@ static const struct export_operations f2fs_export_ops = {
>  	.get_parent = f2fs_get_parent,
>  };
>  
> -loff_t max_file_size(unsigned bits)
> +static loff_t max_file_blocks(void)
>  {
>  	loff_t result = (DEF_ADDRS_PER_INODE - F2FS_INLINE_XATTR_ADDRS);
>  	loff_t leaf_count = ADDRS_PER_BLOCK;
> @@ -925,7 +925,6 @@ loff_t max_file_size(unsigned bits)
>  	leaf_count *= NIDS_PER_BLOCK;
>  	result += leaf_count;
>  
> -	result <<= bits;
>  	return result;
>  }
>  
> @@ -1281,7 +1280,9 @@ try_onemore:
>  	if (err)
>  		goto free_options;
>  
> -	sb->s_maxbytes = max_file_size(le32_to_cpu(raw_super->log_blocksize));
> +	sbi->max_file_blocks = max_file_blocks();
> +	sb->s_maxbytes = sbi->max_file_blocks <<
> +				le32_to_cpu(raw_super->log_blocksize);
>  	sb->s_max_links = F2FS_LINK_MAX;
>  	get_random_bytes(&sbi->s_next_generation, sizeof(u32));
>  
> -- 
> 2.6.3
>