QOTW II: patch review special

I'm scratching my head wondering about this `data_ptr' thing. Is it a disk offset? Is it really a pointer to kernel memory? According to this code it is indeed a kernel pointer, but it then gets stuffed into an unsigned long (wtf?) and then passed to the mysterious read_extent_buffer().

<reviewer throws in the towel on this part of the code>

...

<wonders what the -1 does>

<goes to the btrfs_lookup_xattr() definition site>

<towel goes flying again>

...

<gets interested in btrfs_path.reada>

<greps for a while>

It's snowing towels in here!

I had this strange dream that google airlines was bombing my house with towels....