linux-ext4 - Re: [PATCHv1 8/9] ext4: Add strict range checks while freeing blocks

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Date:   Mon, 7 Feb 2022 17:44:30 +0100
From:   Jan Kara <jack@...e.cz>
To:     Ritesh Harjani <riteshh@...ux.ibm.com>
Cc:     linux-ext4@...r.kernel.org, linux-fsdevel@...r.kernel.org,
        Theodore Ts'o <tytso@....edu>, Jan Kara <jack@...e.cz>,
        Harshad Shirwadkar <harshadshirwadkar@...il.com>
Subject: Re: [PATCHv1 8/9] ext4: Add strict range checks while freeing blocks

On Sat 05-02-22 19:39:57, Ritesh Harjani wrote:
> Currently ext4_mb_clear_bb() & ext4_group_add_blocks() only checks
> whether the given block ranges (which is to be freed) belongs to any FS
> metadata blocks or not, of the block's respective block group.
> But to detect any FS error early, it is better to add more strict
> checkings in those functions which checks whether the given blocks
> belongs to any critical FS metadata or not within system-zone.
> 
> Suggested-by: Jan Kara <jack@...e.cz>
> Signed-off-by: Ritesh Harjani <riteshh@...ux.ibm.com>

Looks good. Feel free to add:

Reviewed-by: Jan Kara <jack@...e.cz>

								Honza

> ---
>  fs/ext4/mballoc.c | 16 +++-------------
>  1 file changed, 3 insertions(+), 13 deletions(-)
> 
> diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
> index 23313963bb56..9f2b3a057918 100644
> --- a/fs/ext4/mballoc.c
> +++ b/fs/ext4/mballoc.c
> @@ -5930,13 +5930,7 @@ static void ext4_mb_clear_bb(handle_t *handle, struct inode *inode,
>  		goto error_return;
>  	}
>  
> -	if (in_range(ext4_block_bitmap(sb, gdp), block, count) ||
> -	    in_range(ext4_inode_bitmap(sb, gdp), block, count) ||
> -	    in_range(block, ext4_inode_table(sb, gdp),
> -		     sbi->s_itb_per_group) ||
> -	    in_range(block + count - 1, ext4_inode_table(sb, gdp),
> -		     sbi->s_itb_per_group)) {
> -
> +	if (!ext4_inode_block_valid(inode, block, count)) {
>  		ext4_error(sb, "Freeing blocks in system zone - "
>  			   "Block = %llu, count = %lu", block, count);
>  		/* err = 0. ext4_std_error should be a no op */
> @@ -6007,7 +6001,7 @@ static void ext4_mb_clear_bb(handle_t *handle, struct inode *inode,
>  						 NULL);
>  			if (err && err != -EOPNOTSUPP)
>  				ext4_msg(sb, KERN_WARNING, "discard request in"
> -					 " group:%d block:%d count:%lu failed"
> +					 " group:%u block:%d count:%lu failed"
>  					 " with %d", block_group, bit, count,
>  					 err);
>  		} else
> @@ -6220,11 +6214,7 @@ int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
>  		goto error_return;
>  	}
>  
> -	if (in_range(ext4_block_bitmap(sb, desc), block, count) ||
> -	    in_range(ext4_inode_bitmap(sb, desc), block, count) ||
> -	    in_range(block, ext4_inode_table(sb, desc), sbi->s_itb_per_group) ||
> -	    in_range(block + count - 1, ext4_inode_table(sb, desc),
> -		     sbi->s_itb_per_group)) {
> +	if (!ext4_sb_block_valid(sb, NULL, block, count)) {
>  		ext4_error(sb, "Adding blocks in system zones - "
>  			   "Block = %llu, count = %lu",
>  			   block, count);
> -- 
> 2.31.1
> 
-- 
Jan Kara <jack@...e.com>
SUSE Labs, CR