Messages in this thread | | | From | Linus Torvalds <> | Date | Thu, 29 Nov 2012 09:19:30 -0800 | Subject | Re: [PATCH v2] Do a proper locking for mmap and block size change |
| |
On Wed, Nov 28, 2012 at 2:01 PM, Mikulas Patocka <mpatocka@redhat.com> wrote: > > This sounds sensible. I'm sending this patch.
This looks much better.
I think I'll apply this for 3.7 (since it's too late to do anything fancier), and then for 3.8 I will rip out all the locking entirely, because looking at the fs/buffer.c patch I wrote up, it's all totally unnecessary.
Adding a ACCESS_ONCE() to the read of the i_blkbits value (when creating new buffers) simply makes the whole locking thing pointless. Just make the page lock protect the block size, and make it per-page, and we're done.
No RCU grace period crap, no expedited mess, no nothing.
Linus
| |