fs/fcntl.c:kill_fasync_rcu() fa_lock must be IRQ-safe
fs/fcntl.c:kill_fasync_rcu() fa_lock must be IRQ-safe

Fix a lockdep-splat-causing regression introduced by commit 989a2979205d
("fasync: RCU and fine grained locking").

kill_fasync() can be called from both process and hard-irq context, so
fa_lock must be taken with IRQs disabled.

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=16230

Reported-by: Sergey Senozhatsky <d9c384f6b6e27869ff3b53bd225c29030ac4166b@gmail.com>
Reported-by: Dominik Brodowski <ba324ca7b1c77fc20bb970d5aff6eea9377918a5@dominikbrodowski.net>
Tested-by: Dominik Brodowski <ba324ca7b1c77fc20bb970d5aff6eea9377918a5@dominikbrodowski.net>
Cc: Maciej Rutecki <b9fc5ee32e9bcd79c24fe827a77b4d80fdc0a8e2@gmail.com>
Acked-by: Eric Dumazet <a0baddf32b28d2f9429941ed4af2fe636e210591@gmail.com>
Cc: Paul E. McKenney <1e0ce936bb9b355d257bf5790d2513c3f28be22b@linux.vnet.ibm.com>
Cc: Lai Jiangshan <4c9eb49378914b743bdd32292c04df29b820d73e@cn.fujitsu.com>
Cc: "David S. Miller" <fe08d3c717adf2ae63592e4c9aec6e3e404d8e3e@davemloft.net>
Acked-by: Peter Zijlstra <645ca7d3a8d3d4f60557176cd361ea8351edc32b@chello.nl>
Signed-off-by: Andrew Morton <5c1e68b099950c134891f0b6e179498a8ebe9cf9@linux-foundation.org>
Signed-off-by: Linus Torvalds <69652caca27c8b940640ad396ab71f93cacec34f@linux-foundation.org>

TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas