From 695a0d0da09e75c4475bbb303def159023ef72ca Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Fri, 4 Mar 2011 15:46:53 -0500 Subject: [PATCH] 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: Josef Bacik --- fs/btrfs/inode.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 64d57e032b4e..888dbdb3b128 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -3557,6 +3557,12 @@ out: 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; -- 2.30.2