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Commit 695a0d0d authored by Josef Bacik's avatar Josef Bacik
Browse files

Btrfs: add a comment explaining what btrfs_cont_expand does 



Everytime I have to deal with btrfs_cont_expand I stare at it for 20 minutes
trying to remember what exactly it does and why the hell we need it.  So add a
comment to save future-Josef some time.  Thanks,

Signed-off-by: default avatarJosef Bacik <josef@redhat.com>
parent 930f028a

fs/btrfs/inode.c

+6 −0
Original line number Diff line number Diff line
@@ -3557,6 +3557,12 @@ static int btrfs_truncate_page(struct address_space *mapping, loff_t from) 
	return ret;

}



/*

 * This function puts in dummy file extents for the area we're creating a hole

 * for.  So if we are truncating this file to a larger size we need to insert

 * these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for

 * the range between oldsize and size

 */

int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)

{

	struct btrfs_trans_handle *trans;