Commit c9877b20 authored May 01, 2009 by Eric Sandeen Committed by Theodore Ts'o May 01, 2009

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: Eric Sandeen <sandeen@redhat.com>
Reported-by: Carl Henrik Lunde <chlunde@ping.uio.no>
Tested-by: Carl Henrik Lunde <chlunde@ping.uio.no>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

parent 19ba0559

fs/ext4/extents.c

+3 −3

Original line number	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)
		{
		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 physical;
		__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
		*/
		if (logical + length - 1 == EXT_MAX_BLOCK \|\|
		ext4_ext_next_allocated_block(path) == EXT_MAX_BLOCK)
		if (ext4_ext_next_allocated_block(path) == EXT_MAX_BLOCK \|\|
		newex->ec_block + newex->ec_len - 1 == EXT_MAX_BLOCK)
		flags \|= FIEMAP_EXTENT_LAST;

		error = fiemap_fill_next_extent(fieinfo, logical, physical,

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