tests: add regression tests for group descriptors with bad checksums

Add tests to examine how e2fsck deals with (a) the block bitmap being
corrupt; (b) the inode bitmap being corrupt; (c) the bitmap checksums
being incorrect (but the bitmaps are fine); and (d) the group
descriptor checksum itself is incorrect.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

tests/f_bad_bbitmap/expect.1

@@ -0,0 +1,15 @@
+One or more block group descriptor checksums are invalid.  Fix? yes
+
+Group descriptor 0 checksum is 0x49ff, should be 0x4972.  FIXED.
+Pass 1: Checking inodes, blocks, and sizes
+Pass 2: Checking directory structure
+Pass 3: Checking directory connectivity
+Pass 4: Checking reference counts
+Pass 5: Checking group summary information
+Block bitmap differences:  -(8--10) -(12--17) -(19--31)
+Fix? yes
+
+
+test_filesys: ***** FILE SYSTEM WAS MODIFIED *****
+test_filesys: 11/128 files (0.0% non-contiguous), 18/512 blocks
+Exit status is 1

tests/f_bad_bbitmap/expect.2

@@ -0,0 +1,7 @@
+Pass 1: Checking inodes, blocks, and sizes
+Pass 2: Checking directory structure
+Pass 3: Checking directory connectivity
+Pass 4: Checking reference counts
+Pass 5: Checking group summary information
+test_filesys: 11/128 files (0.0% non-contiguous), 18/512 blocks
+Exit status is 0

tests/f_bad_bbitmap/name

@@ -0,0 +1 @@
+corrupt block bitmap (metadata_csum)

tests/f_bad_bmap_csum/expect.1

@@ -0,0 +1,16 @@
+One or more block group descriptor checksums are invalid.  Fix? yes
+
+Group descriptor 0 checksum is 0x4972, should be 0x7074.  FIXED.
+Pass 1: Checking inodes, blocks, and sizes
+Pass 2: Checking directory structure
+Pass 3: Checking directory connectivity
+Pass 4: Checking reference counts
+Pass 5: Checking group summary information
+Inode bitmap differences: Group 0 inode bitmap does not match checksum.
+FIXED.
+Block bitmap differences: Group 0 block bitmap does not match checksum.
+FIXED.
+
+test_filesys: ***** FILE SYSTEM WAS MODIFIED *****
+test_filesys: 11/128 files (0.0% non-contiguous), 18/512 blocks
+Exit status is 1

tests/f_bad_bmap_csum/expect.2

@@ -0,0 +1,7 @@
+Pass 1: Checking inodes, blocks, and sizes
+Pass 2: Checking directory structure
+Pass 3: Checking directory connectivity
+Pass 4: Checking reference counts
+Pass 5: Checking group summary information
+test_filesys: 11/128 files (0.0% non-contiguous), 18/512 blocks
+Exit status is 0

tests/f_bad_bmap_csum/name

@@ -0,0 +1 @@
+bad block/inode bitmap csum (metadata_csum)

tests/f_bad_gdt_csum/expect.1

@@ -0,0 +1,10 @@
+One or more block group descriptor checksums are invalid.  Fix? yes
+
+Group descriptor 0 checksum is 0xffff, should be 0x4972.  FIXED.
+Pass 1: Checking inodes, blocks, and sizes
+Pass 2: Checking directory structure
+Pass 3: Checking directory connectivity
+Pass 4: Checking reference counts
+Pass 5: Checking group summary information
+test_filesys: 11/128 files (0.0% non-contiguous), 18/512 blocks
+Exit status is 0

tests/f_bad_gdt_csum/expect.2

@@ -0,0 +1,7 @@
+Pass 1: Checking inodes, blocks, and sizes
+Pass 2: Checking directory structure
+Pass 3: Checking directory connectivity
+Pass 4: Checking reference counts
+Pass 5: Checking group summary information
+test_filesys: 11/128 files (0.0% non-contiguous), 18/512 blocks
+Exit status is 0

tests/f_bad_gdt_csum/name

@@ -0,0 +1 @@
+bad group descriptor csum (metadata_csum)

tests/f_bad_ibitmap/expect.1

@@ -0,0 +1,15 @@
+One or more block group descriptor checksums are invalid.  Fix? yes
+
+Group descriptor 0 checksum is 0xffff, should be 0x4972.  FIXED.
+Pass 1: Checking inodes, blocks, and sizes
+Pass 2: Checking directory structure
+Pass 3: Checking directory connectivity
+Pass 4: Checking reference counts
+Pass 5: Checking group summary information
+Inode bitmap differences:  -(12--32)
+Fix? yes
+
+
+test_filesys: ***** FILE SYSTEM WAS MODIFIED *****
+test_filesys: 11/128 files (0.0% non-contiguous), 18/512 blocks
+Exit status is 1

tests/f_bad_ibitmap/expect.2

@@ -0,0 +1,7 @@
+Pass 1: Checking inodes, blocks, and sizes
+Pass 2: Checking directory structure
+Pass 3: Checking directory connectivity
+Pass 4: Checking reference counts
+Pass 5: Checking group summary information
+test_filesys: 11/128 files (0.0% non-contiguous), 18/512 blocks
+Exit status is 0

tests/f_bad_ibitmap/name

@@ -0,0 +1 @@
+corrupt inode bitmap (metadata_csum)