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Commit 515f41c3 authored by Aneesh Kumar K.V's avatar Aneesh Kumar K.V Committed by Theodore Ts'o
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ext4: Ensure zeroout blocks have no dirty metadata 



This fixes a bug (found by Curt Wohlgemuth) in which new blocks
returned from an extent created with ext4_ext_zeroout() can have dirty
metadata still associated with them.

Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: default avatarCurt Wohlgemuth <curtw@google.com>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent 2faf2e19

fs/ext4/extents.c

+20 −0
Original line number Diff line number Diff line
@@ -3023,6 +3023,14 @@ static int ext4_convert_unwritten_extents_dio(handle_t *handle, 
	return err;

}



static void unmap_underlying_metadata_blocks(struct block_device *bdev,

			sector_t block, int count)

{

	int i;

	for (i = 0; i < count; i++)

                unmap_underlying_metadata(bdev, block + i);

}



static int

ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode,

			ext4_lblk_t iblock, unsigned int max_blocks,
@@ -3098,6 +3106,18 @@ ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode, 
	} else

		allocated = ret;

	set_buffer_new(bh_result);

	/*

	 * if we allocated more blocks than requested

	 * we need to make sure we unmap the extra block

	 * allocated. The actual needed block will get

	 * unmapped later when we find the buffer_head marked

	 * new.

	 */

	if (allocated > max_blocks) {

		unmap_underlying_metadata_blocks(inode->i_sb->s_bdev,

					newblock + max_blocks,

					allocated - max_blocks);

	}

map_out:

	set_buffer_mapped(bh_result);

out1: