Re: [BUG ext4?] Working tree getting out of date "spontaneously"

On Fri, Jun 05, 2009 at 08:35:38PM +0200, Björn Steinbrink wrote:

quoted

So the next step is to create an ext3 filesystem with a git repository
on it, and then to gradually turn on various ext4 specific features
and see when the bug ends up getting replicated.  If I had to guess
it's the lack (or absense) of the extents feature, but I'll have to
run the test and find out for sure.

Yep, seems to be extents. Test script:

OK, I see what's going on.  When doing delayed allocation, and we're
not using extents, the call to ext4_get_blocks() which does the
allocation ultimately ends up calling ext4_slice_branch if the inode
is using direct/indirect blocks instead of extents.
ext4_splice_branch() sets ctime.  Taking out the this line in
fs/ext4/inode.c:ext4_splice_branch() should fix things:


	/* We are done with atomic stuff, now do the rest of housekeeping */

-	inode->i_ctime = ext4_current_time(inode);
	ext4_mark_inode_dirty(handle, inode);

	/* had we spliced it onto indirect block? */

I'm pretty sure we don't need to set i_ctime anywhere else, since we
don't have a similar line in the extents code and we
fs/inode.c:file_update_time() should take care updating i_ctime where
it needs it, but I want to take a closer look to be sure.

   	     	   	   	  	 - Ted