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Commit c9877b20 authored by Eric Sandeen's avatar Eric Sandeen Committed by Theodore Ts'o
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ext4: fix for fiemap last-block test 



Carl Henrik Lunde reported and debugged this; the test for the
last allocated block was comparing bytes to blocks in this test:

	if (logical + length - 1 == EXT_MAX_BLOCK ||
	    ext4_ext_next_allocated_block(path) == EXT_MAX_BLOCK)
		flags |= FIEMAP_EXTENT_LAST;

so any extent which ended right at 4G was stopping the extent
walk.  Just replacing these values with the extent block &
length should fix it.

Also give blksize_bits a saner type, and reverse the order 
of the tests to make the more likely case tested first.

Signed-off-by: default avatarEric Sandeen <sandeen@redhat.com>
Reported-by: default avatarCarl Henrik Lunde <chlunde@ping.uio.no>
Tested-by: default avatarCarl Henrik Lunde <chlunde@ping.uio.no>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent 19ba0559

fs/ext4/extents.c

+3 −3
Original line number Original line Diff line number Diff line
@@ -3196,7 +3196,7 @@ static int ext4_ext_fiemap_cb(struct inode *inode, struct ext4_ext_path *path, 
		       void *data)

		       void *data)

{

{

	struct fiemap_extent_info *fieinfo = data;

	struct fiemap_extent_info *fieinfo = data;

	unsigned long blksize_bits = inode->i_sb->s_blocksize_bits;

	unsigned char blksize_bits = inode->i_sb->s_blocksize_bits;

	__u64	logical;

	__u64	logical;

	__u64	physical;

	__u64	physical;

	__u64	length;

	__u64	length;
@@ -3243,8 +3243,8 @@ static int ext4_ext_fiemap_cb(struct inode *inode, struct ext4_ext_path *path, 
	 *

	 *

	 * XXX this might miss a single-block extent at EXT_MAX_BLOCK

	 * XXX this might miss a single-block extent at EXT_MAX_BLOCK

	 */

	 */

	if (logical + length - 1 == EXT_MAX_BLOCK ||

	if (ext4_ext_next_allocated_block(path) == EXT_MAX_BLOCK ||

	    ext4_ext_next_allocated_block(path) == EXT_MAX_BLOCK)

	    newex->ec_block + newex->ec_len - 1 == EXT_MAX_BLOCK)

		flags |= FIEMAP_EXTENT_LAST;

		flags |= FIEMAP_EXTENT_LAST;





	error = fiemap_fill_next_extent(fieinfo, logical, physical,

	error = fiemap_fill_next_extent(fieinfo, logical, physical,