From: J. Bruce Fields <bfields@citi.umich.edu>
Date: Wed, 12 Sep 2007 22:56:12 +0000 (-0400)
Subject: knfsd: let nfsd manage timing out its own leases
X-Git-Tag: v2.6.24-rc1~1293^2~3
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0272e1fd9f4fa8a43357c168e081744f99e67195;p=pandora-kernel.git

knfsd: let nfsd manage timing out its own leases

Currently there's a race that can cause an oops in generic_setlease.

(In detail: nfsd, when it removes a lease, does so by calling
vfs_setlease() with F_UNLCK and a pointer to the fl_flock field, which
in turn points to nfsd's existing lease; but the first thing the
setlease code does is call time_out_leases().  If the lease happens to
already be beyond the lease break time, that will free the lease and (in
nfsd's release_private callback) set fl_flock to NULL, leading to a NULL
deference soon after in vfs_setlease().)

There are probably other things to fix here too, but it seems inherently
racy to allow either locks.c or nfsd to time out this lease.  Instead
just set the fl_break_time to 0 (preventing locks.c from ever timing out
this lock) and leave it up to nfsd's laundromat thread to deal with it.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
---

Reading git-diff-tree failed