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: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Curt Wohlgemuth <curtw@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This commit is contained in:
Aneesh Kumar K.V 2009-12-29 23:39:06 -05:00 committed by Theodore Ts'o
parent 2faf2e19dd
commit 515f41c33a

View File

@ -3023,6 +3023,14 @@ out:
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 @@ out:
} 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: