linux-ext4 - Re: [PATCH] ext2: Mark the buffer as unmapped before reading the next quota block

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Date:	Mon, 2 Feb 2009 11:34:29 +0100
From:	Jan Kara <jack@...e.cz>
To:	Manish Katiyar <mkatiyar@...il.com>
Cc:	Theodore Ts'o <tytso@....edu>, ext4 <linux-ext4@...r.kernel.org>,
	cmm@...ibm.com
Subject: Re: [PATCH] ext2: Mark the buffer as unmapped before reading the
	next quota block

On Mon 02-02-09 15:34:27, Manish Katiyar wrote:
> Hi Jan,
> 
> This is in continuation with the previous patch
> (http://patchwork.ozlabs.org/patch/20275/) . We also need to set the
> buffer as unmapped before reading the next block. I don't think quota
> files can have holes, but atleast for correctness, otherwise once we
> have read a block, tmp_bh is always mapped even for holes.
> 
> 
> Signed-off-by: Manish Katiyar <mkatiyar@...il.com>
> ---
>  fs/ext2/super.c |    1 +
>  1 files changed, 1 insertions(+), 0 deletions(-)
> 
> diff --git a/fs/ext2/super.c b/fs/ext2/super.c
> index da8bdea..b4e7633 100644
> --- a/fs/ext2/super.c
> +++ b/fs/ext2/super.c
> @@ -1328,6 +1328,7 @@ static ssize_t ext2_quota_read(struct
> super_block *sb, int type, char *data,
>  				sb->s_blocksize - offset : toread;
> 
>  		tmp_bh.b_state = 0;
> +		clear_buffer_mapped(&tmp_bh);
  I don't get this. When b_state is 0, then in particuler the buffer is not
mapped. So why clear the mapped bit explicitely?

>  		err = ext2_get_block(inode, blk, &tmp_bh, 0);
>  		if (err < 0)
>  			return err;

									Honza
-- 
Jan Kara <jack@...e.cz>
SUSE Labs, CR
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