Andreas Dilger 2bc3041754 debugfs, e2fsck: fix s_desc_size handling ... The s_desc_size in the superblock specifies the group descriptor size in bytes, but in various places the EXT4_FEATURE_INCOMPAT_64BIT flag implies that the descriptor size is EXT2_MIN_DESC_SIZE_64BIT (64 bytes) instead of checking the actual size. In other places, the s_desc_size field is used without checking for INCOMPAT_64BIT. In the case of ext2fs_group_desc() the s_desc_size was being ignored, and assumed to be sizeof(struct ext4_group_desc), which would result in garbage for any but the first group descriptor. Similarly, in ext2fs_group_desc_csum() and print_csum() they assumed that the maximum group descriptor size was sizeof(struct ext4_group_desc). Fix these functions to use the actual superblock s_desc_size if INCOMPAT_64BIT. Conversely, in ext2fs_swap_group_desc2() s_desc_size was used without checking for INCOMPAT_64BIT being set. The e2fsprogs behaviour is different than that of the kernel, which always checks INCOMPAT_64BIT, and only uses s_desc_size to determine the offset of group descriptors and what range of bytes to checksum. Allow specifying the s_desc_size field at mke2fs time with the "-E desc_size=NNN" option. Allow a power-of-two s_desc_size value up to s_blocksize if INCOMPAT_64BIT is specified. This is not expected to be used by regular users at this time, so it is not currently documented in the mke2fs usage or man page. Add m_desc_size_128, f_desc_size_128, and f_desc_bad test cases to verify mke2fs and e2fsck handling of larger group descriptor sizes. Signed-off-by: Andreas Dilger <adilger@dilger.ca> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>		2013-12-24 22:50:19 -05:00
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expect.1	debugfs, e2fsck: fix s_desc_size handling	2013-12-24 22:50:19 -05:00
expect.2	debugfs, e2fsck: fix s_desc_size handling	2013-12-24 22:50:19 -05:00
script	debugfs, e2fsck: fix s_desc_size handling	2013-12-24 22:50:19 -05:00