Re: [PATCH 6/9] fat: Fix possibly missing inode write on fsync(2)

[OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>]

Jan Kara <jack@suse.cz> writes:

> Use mmb inode buffer writeout infrastructure to reliably write out
> inode's buffer on fsync(2).

> Signed-off-by: Jan Kara <jack@suse.cz>
> ---
>  fs/fat/inode.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/fs/fat/inode.c b/fs/fat/inode.c
> index 28f78df086ef..4ca00b7a618b 100644
> --- a/fs/fat/inode.c
> +++ b/fs/fat/inode.c
> @@ -907,6 +907,7 @@ static int __fat_write_inode(struct inode *inode, int wait)
>  	}
>  	spin_unlock(&sbi->inode_hash_lock);
>  	mark_buffer_dirty(bh);
> +	MSDOS_I(inode)->i_metadata_bhs.inode_blk = bh->b_blocknr;

When inode position was changed/removed, this will point the wrong
block. And maybe sync a unrelated block and wait.

>  	err = 0;
>  	if (wait)
>  		err = sync_dirty_buffer(bh);
> @@ -925,7 +926,7 @@ static int fat_write_inode(struct inode *inode, struct writeback_control *wbc)
>  		err = fat_clusters_flush(sb);
>  		mutex_unlock(&MSDOS_SB(sb)->s_lock);
>  	} else
> -		err = __fat_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
> +		err = __fat_write_inode(inode, 0);
>  
>  	return err;
>  }

-- 
OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>