Re: [PATCH] btrfs: Move some super block check to btrfs_check_super_valid

[Qu Wenruo <quwenruo@cn.fujitsu.com>]

I am very sorry that branch btrfs-next seems changed all the printk,
so I'll rebase this to btrfs-next branch.

Qu

On tue, 24 Dec 2013 11:49:56 +0800, Qu Wenruo wrote:
> Move some early check to btrfs_check_super_valid:
> - sectorsize check
> - leafsize == nodesize check
> - leafsize > BTRFS_MAX_METADATA_BLOCKSIZE check
> - incompat_flags check
>
> and remove the duplicant magic check of btrfs_super_block,
> since btrfs_read_dev_super already checked the magic number.
>
> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
> ---
>  fs/btrfs/disk-io.c | 76 ++++++++++++++++++++++++------------------------------
>  1 file changed, 34 insertions(+), 42 deletions(-)
>
> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
> index 8072cfa..04ad1d3 100644
> --- a/fs/btrfs/disk-io.c
> +++ b/fs/btrfs/disk-io.c
> @@ -2388,33 +2388,6 @@ int open_ctree(struct super_block *sb,
>  		goto fail_alloc;
>  	}
>  
> -	features = btrfs_super_incompat_flags(disk_super) &
> -		~BTRFS_FEATURE_INCOMPAT_SUPP;
> -	if (features) {
> -		printk(KERN_ERR "BTRFS: couldn't mount because of "
> -		       "unsupported optional features (%Lx).\n",
> -		       features);
> -		err = -EINVAL;
> -		goto fail_alloc;
> -	}
> -
> -	if (btrfs_super_leafsize(disk_super) !=
> -	    btrfs_super_nodesize(disk_super)) {
> -		printk(KERN_ERR "BTRFS: couldn't mount because metadata "
> -		       "blocksizes don't match.  node %d leaf %d\n",
> -		       btrfs_super_nodesize(disk_super),
> -		       btrfs_super_leafsize(disk_super));
> -		err = -EINVAL;
> -		goto fail_alloc;
> -	}
> -	if (btrfs_super_leafsize(disk_super) > BTRFS_MAX_METADATA_BLOCKSIZE) {
> -		printk(KERN_ERR "BTRFS: couldn't mount because metadata "
> -		       "blocksize (%d) was too large\n",
> -		       btrfs_super_leafsize(disk_super));
> -		err = -EINVAL;
> -		goto fail_alloc;
> -	}
> -
>  	features = btrfs_super_incompat_flags(disk_super);
>  	features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
>  	if (tree_root->fs_info->compress_type == BTRFS_COMPRESS_LZO)
> @@ -2582,17 +2555,6 @@ int open_ctree(struct super_block *sb,
>  	sb->s_blocksize = sectorsize;
>  	sb->s_blocksize_bits = blksize_bits(sectorsize);
>  
> -	if (btrfs_super_magic(disk_super) != BTRFS_MAGIC) {
> -		printk(KERN_INFO "btrfs: valid FS not found on %s\n", sb->s_id);
> -		goto fail_sb_buffer;
> -	}
> -
> -	if (sectorsize != PAGE_SIZE) {
> -		printk(KERN_WARNING "btrfs: Incompatible sector size(%lu) "
> -		       "found on %s\n", (unsigned long)sectorsize, sb->s_id);
> -		goto fail_sb_buffer;
> -	}
> -
>  	mutex_lock(&fs_info->chunk_mutex);
>  	ret = btrfs_read_sys_array(tree_root);
>  	mutex_unlock(&fs_info->chunk_mutex);
> @@ -3706,11 +3668,41 @@ int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
>  }
>  
>  static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
> -			      int read_only)
> +				   int read_only)
>  {
> -	/*
> -	 * Placeholder for checks
> -	 */
> +	struct btrfs_super_block *disk_super = fs_info->super_copy;
> +	u32 sectorsize = btrfs_super_sectorsize(disk_super);
> +	u64 features;
> +
> +	if (sectorsize != PAGE_SIZE) {
> +		printk(KERN_WARNING "btrfs: Incompatible sector size(%lu) "
> +		       "found on %s\n", (unsigned long)sectorsize,
> +		       fs_info->sb->s_id);
> +		return -EINVAL;
> +	}
> +	if (btrfs_super_leafsize(disk_super) !=
> +	    btrfs_super_nodesize(disk_super)) {
> +		printk(KERN_ERR "BTRFS: couldn't mount because metadata "
> +		       "blocksizes don't match.  node %d leaf %d\n",
> +		       btrfs_super_nodesize(disk_super),
> +		       btrfs_super_leafsize(disk_super));
> +		return -EINVAL;
> +	}
> +	if (btrfs_super_leafsize(disk_super) > BTRFS_MAX_METADATA_BLOCKSIZE) {
> +		printk(KERN_ERR "BTRFS: couldn't mount because metadata "
> +		       "blocksize (%d) was too large\n",
> +		       btrfs_super_leafsize(disk_super));
> +		return -EINVAL;
> +	}
> +
> +	features = btrfs_super_incompat_flags(disk_super) &
> +		~BTRFS_FEATURE_INCOMPAT_SUPP;
> +	if (features) {
> +		printk(KERN_ERR "BTRFS: couldn't mount because of "
> +		       "unsupported optional features (%Lx).\n",
> +		       features);
> +		return -EINVAL;
> +	}
>  	return 0;
>  }
>