nfs4: queue free_lock_state job submission to nfsiod
We got a report of the following warning in Fedora:
BUG: sleeping function called from invalid context at mm/slub.c:969
in_atomic(): 1, irqs_disabled(): 0, pid: 533, name: bash
3 locks held by bash/533:
#0: (&sp->so_delegreturn_mutex){+.+...}, at: [<
ffffffffa033da62>] nfs4_proc_lock+0x262/0x910 [nfsv4]
#1: (&nfsi->rwsem){.+.+.+}, at: [<
ffffffffa033da6a>] nfs4_proc_lock+0x26a/0x910 [nfsv4]
#2: (&sb->s_type->i_lock_key#23){+.+...}, at: [<
ffffffff812998dc>] flock_lock_file_wait+0x8c/0x3a0
CPU: 0 PID: 533 Comm: bash Not tainted 3.15.0-0.rc1.git1.1.fc21.x86_64 #1
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
0000000000000000 00000000d664ff3c ffff880078b69a70 ffffffff817e82e0
0000000000000000 ffff880078b69a98 ffffffff810cf1a4 0000000000000050
0000000000000050 ffff88007cc01a00 ffff880078b69ad8 ffffffff8121449e
Call Trace:
[<
ffffffff817e82e0>] dump_stack+0x4d/0x66
[<
ffffffff810cf1a4>] __might_sleep+0x184/0x240
[<
ffffffff8121449e>] kmem_cache_alloc_trace+0x4e/0x330
[<
ffffffffa0331124>] ? nfs4_release_lockowner+0x74/0x110 [nfsv4]
[<
ffffffffa0331124>] nfs4_release_lockowner+0x74/0x110 [nfsv4]
[<
ffffffffa0352340>] nfs4_put_lock_state+0x90/0xb0 [nfsv4]
[<
ffffffffa0352375>] nfs4_fl_release_lock+0x15/0x20 [nfsv4]
[<
ffffffff81297515>] locks_free_lock+0x45/0x90
[<
ffffffff8129996c>] flock_lock_file_wait+0x11c/0x3a0
[<
ffffffffa033da6a>] ? nfs4_proc_lock+0x26a/0x910 [nfsv4]
[<
ffffffffa033301e>] do_vfs_lock+0x1e/0x30 [nfsv4]
[<
ffffffffa033da79>] nfs4_proc_lock+0x279/0x910 [nfsv4]
[<
ffffffff810dbb26>] ? local_clock+0x16/0x30
[<
ffffffff810f5a3f>] ? lock_release_holdtime.part.28+0xf/0x200
[<
ffffffffa02f820c>] do_unlk+0x8c/0xc0 [nfs]
[<
ffffffffa02f85c5>] nfs_flock+0xa5/0xf0 [nfs]
[<
ffffffff8129a6f6>] locks_remove_file+0xb6/0x1e0
[<
ffffffff812159d8>] ? kfree+0xd8/0x2d0
[<
ffffffff8123bc63>] __fput+0xd3/0x210
[<
ffffffff8123bdee>] ____fput+0xe/0x10
[<
ffffffff810bfb6d>] task_work_run+0xcd/0xf0
[<
ffffffff81019cd1>] do_notify_resume+0x61/0x90
[<
ffffffff817fbea2>] int_signal+0x12/0x17
The problem is that NFSv4 is trying to do an allocation from
fl_release_private (in order to send a RELEASE_LOCKOWNER call). That
function can be called while holding the inode->i_lock, and it's
currently set up to do __GFP_WAIT allocations. v4.1 code has a
similar problem.
This patch adds a work_struct to the nfs4_lock_state and has the code
queue the free_lock_state operation to nfsiod.
Reported-by: Josh Stone <jistone@redhat.com>
Signed-off-by: Jeff Layton <jlayton@poochiereds.net>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>