From febbc583319b567fe3d83e521cc2ace9be8d1501 Mon Sep 17 00:00:00 2001 From: Benjamin Lim Date: Fri, 29 Mar 2019 07:29:45 -0400 Subject: Fix ext4 block group descriptor sizing Ext4 allows for arbitrarily sized block group descriptors when 64-bit addressing is enabled, which was previously not properly supported. This patch dynamically allocates a chunk of memory of the correct size. Signed-off-by: Benjamin Lim --- fs/ext4/ext4_common.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) (limited to 'fs') diff --git a/fs/ext4/ext4_common.c b/fs/ext4/ext4_common.c index feffbfa9a9e..464c33d0d74 100644 --- a/fs/ext4/ext4_common.c +++ b/fs/ext4/ext4_common.c @@ -1587,7 +1587,7 @@ static int ext4fs_blockgroup int ext4fs_read_inode(struct ext2_data *data, int ino, struct ext2_inode *inode) { - struct ext2_block_group blkgrp; + struct ext2_block_group *blkgrp; struct ext2_sblock *sblock = &data->sblock; struct ext_filesystem *fs = get_fs(); int log2blksz = get_fs()->dev_desc->log2blksz; @@ -1595,17 +1595,28 @@ int ext4fs_read_inode(struct ext2_data *data, int ino, struct ext2_inode *inode) long int blkno; unsigned int blkoff; + /* Allocate blkgrp based on gdsize (for 64-bit support). */ + blkgrp = zalloc(get_fs()->gdsize); + if (!blkgrp) + return 0; + /* It is easier to calculate if the first inode is 0. */ ino--; status = ext4fs_blockgroup(data, ino / le32_to_cpu - (sblock->inodes_per_group), &blkgrp); - if (status == 0) + (sblock->inodes_per_group), blkgrp); + if (status == 0) { + free(blkgrp); return 0; + } inodes_per_block = EXT2_BLOCK_SIZE(data) / fs->inodesz; - blkno = ext4fs_bg_get_inode_table_id(&blkgrp, fs) + + blkno = ext4fs_bg_get_inode_table_id(blkgrp, fs) + (ino % le32_to_cpu(sblock->inodes_per_group)) / inodes_per_block; blkoff = (ino % inodes_per_block) * fs->inodesz; + + /* Free blkgrp as it is no longer required. */ + free(blkgrp); + /* Read the inode. */ status = ext4fs_devread((lbaint_t)blkno << (LOG2_BLOCK_SIZE(data) - log2blksz), blkoff, -- cgit v1.2.3