Commit cd6bb35b authored by Theodore Ts'o's avatar Theodore Ts'o
Browse files

ext4: use more strict checks for inodes_per_block on mount 



Centralize the checks for inodes_per_block and be more strict to make
sure the inodes_per_block_group can't end up being zero.

Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
Reviewed-by: default avatarAndreas Dilger <adilger@dilger.ca>
Cc: stable@vger.kernel.org
parent 5aee0f8a

fs/ext4/super.c

+6 −9
Original line number Diff line number Diff line
@@ -3668,12 +3668,16 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) 


	sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);

	sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);

	if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)

		goto cantfind_ext4;



	sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);

	if (sbi->s_inodes_per_block == 0)

		goto cantfind_ext4;

	if (sbi->s_inodes_per_group < sbi->s_inodes_per_block ||

	    sbi->s_inodes_per_group > blocksize * 8) {

		ext4_msg(sb, KERN_ERR, "invalid inodes per group: %lu\n",

			 sbi->s_blocks_per_group);

		goto failed_mount;

	}

	sbi->s_itb_per_group = sbi->s_inodes_per_group /

					sbi->s_inodes_per_block;

	sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
@@ -3756,13 +3760,6 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) 
	}

	sbi->s_cluster_ratio = clustersize / blocksize;



	if (sbi->s_inodes_per_group > blocksize * 8) {

		ext4_msg(sb, KERN_ERR,

		       "#inodes per group too big: %lu",

		       sbi->s_inodes_per_group);

		goto failed_mount;

	}



	/* Do we have standard group size of clustersize * 8 blocks ? */

	if (sbi->s_blocks_per_group == clustersize << 3)

		set_opt2(sb, STD_GROUP_SIZE);