linux-stable.git/fs/nfs/callback.c, branch linux-3.4.y

nfs: fix high load average due to callback thread sleeping

2015-09-18T01:20:32+00:00

commit 5d05e54af3cdbb13cf19c557ff2184781b91a22c upstream.

Chuck pointed out a problem that crept in with commit 6ffa30d3f734 (nfs:
don't call blocking operations while !TASK_RUNNING). Linux counts tasks
in uninterruptible sleep against the load average, so this caused the
system's load average to be pinned at at least 1 when there was a
NFSv4.1+ mount active.

Not a huge problem, but it's probably worth fixing before we get too
many complaints about it. This patch converts the code back to use
TASK_INTERRUPTIBLE sleep, simply has it flush any signals on each loop
iteration. In practice no one should really be signalling this thread at
all, so I think this is reasonably safe.

With this change, there's also no need to game the hung task watchdog so
we can also convert the schedule_timeout call back to a normal schedule.

Reported-by: Chuck Lever 
Signed-off-by: Jeff Layton 
Tested-by: Chuck Lever 
Fixes: commit 6ffa30d3f734 (“nfs: don't call blocking . . .”)
Signed-off-by: Trond Myklebust 
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li

nfs: don't call blocking operations while !TASK_RUNNING

2015-09-18T01:20:31+00:00

commit 6ffa30d3f734d4f6b478081dfc09592021028f90 upstream.

Bruce reported seeing this warning pop when mounting using v4.1:

     ------------[ cut here ]------------
     WARNING: CPU: 1 PID: 1121 at kernel/sched/core.c:7300 __might_sleep+0xbd/0xd0()
    do not call blocking ops when !TASK_RUNNING; state=1 set at [] prepare_to_wait+0x2f/0x90
    Modules linked in: rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace sunrpc fscache ip6t_rpfilter ip6t_REJECT nf_reject_ipv6 xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw snd_hda_codec_generic snd_hda_intel snd_hda_controller snd_hda_codec snd_hwdep snd_pcm snd_timer ppdev joydev snd virtio_console virtio_balloon pcspkr serio_raw parport_pc parport pvpanic floppy soundcore i2c_piix4 virtio_blk virtio_net qxl drm_kms_helper ttm drm virtio_pci virtio_ring ata_generic virtio pata_acpi
    CPU: 1 PID: 1121 Comm: nfsv4.1-svc Not tainted 3.19.0-rc4+ #25
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140709_153950- 04/01/2014
     0000000000000000 000000004e5e3f73 ffff8800b998fb48 ffffffff8186ac78
     0000000000000000 ffff8800b998fba0 ffff8800b998fb88 ffffffff810ac9da
     ffff8800b998fb68 ffffffff81c923e7 00000000000004d9 0000000000000000
    Call Trace:
     [] dump_stack+0x4c/0x65
     [] warn_slowpath_common+0x8a/0xc0
     [] warn_slowpath_fmt+0x55/0x70
     [] ? prepare_to_wait+0x2f/0x90
     [] ? prepare_to_wait+0x2f/0x90
     [] __might_sleep+0xbd/0xd0
     [] kmem_cache_alloc_trace+0x243/0x430
     [] ? groups_alloc+0x3e/0x130
     [] groups_alloc+0x3e/0x130
     [] svcauth_unix_accept+0x16e/0x290 [sunrpc]
     [] svc_authenticate+0xe1/0xf0 [sunrpc]
     [] svc_process_common+0x244/0x6a0 [sunrpc]
     [] bc_svc_process+0x1c4/0x260 [sunrpc]
     [] nfs41_callback_svc+0x128/0x1f0 [nfsv4]
     [] ? wait_woken+0xc0/0xc0
     [] ? nfs4_callback_svc+0x60/0x60 [nfsv4]
     [] kthread+0x11f/0x140
     [] ? local_clock+0x15/0x30
     [] ? kthread_create_on_node+0x250/0x250
     [] ret_from_fork+0x7c/0xb0
     [] ? kthread_create_on_node+0x250/0x250
    ---[ end trace 675220a11e30f4f2 ]---

nfs41_callback_svc does most of its work while in TASK_INTERRUPTIBLE,
which is just wrong. Fix that by finishing the wait immediately if we've
found that the list has something on it.

Also, we don't expect this kthread to accept signals, so we should be
using a TASK_UNINTERRUPTIBLE sleep instead. That however, opens us up
hung task warnings from the watchdog, so have the schedule_timeout
wake up every 60s if there's no callback activity.

Reported-by: "J. Bruce Fields" 
Signed-off-by: Jeff Layton 
Signed-off-by: Trond Myklebust 
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li

NFS: hard-code init_net for NFS callback transports

2012-07-16T16:04:40+00:00

upstream commit 12918b10d59e975fd5241eef03ef9e6d5ea3dcfe.

In case of destroying mount namespace on child reaper exit, nsproxy is zeroed
to the point already. So, dereferencing of it is invalid.
This patch hard-code "init_net" for all network namespace references for NFS
callback services. This will be fixed with proper NFS callback
containerization.

Signed-off-by: Stanislav Kinsbursky 
Signed-off-by: J. Bruce Fields 
Signed-off-by: Greg Kroah-Hartman

SUNRPC: move per-net operations from svc_destroy()

2012-07-16T16:04:39+00:00

upstream commit 786185b5f8abefa6a8a16695bb4a59c164d5a071.

The idea is to separate service destruction and per-net operations,
because these are two different things and the mix looks ugly.

Notes:

1) For NFS server this patch looks ugly (sorry for that). But these
place will be rewritten soon during NFSd containerization.

2) LockD per-net counter increase int lockd_up() was moved prior to
make_socks() to make lockd_down_net() call safe in case of error.

Signed-off-by: Stanislav Kinsbursky 
Signed-off-by: J. Bruce Fields 
Signed-off-by: Greg Kroah-Hartman

SUNRPC: new svc_bind() routine introduced

2012-07-16T16:04:39+00:00

upstream commit 9793f7c88937e7ac07305ab1af1a519225836823.

This new routine is responsible for service registration in a specified
network context.

The idea is to separate service creation from per-net operations.

Note also: since registering service with svc_bind() can fail, the
service will be destroyed and during destruction it will try to
unregister itself from rpcbind. In this case unregistration has to be
skipped.

Signed-off-by: Stanislav Kinsbursky 
Signed-off-by: J. Bruce Fields 
Signed-off-by: Greg Kroah-Hartman

NFS: Fix a number of sparse warnings

2012-03-11T19:14:16+00:00

Fix a number of "warning: symbol 'foo' was not declared. Should it be
static?" conditions.

Fix 2 cases of "warning: Using plain integer as NULL pointer"

fs/nfs/delegation.c:263:31: warning: restricted fmode_t degrades to integer
  - We want to allow upgrades to a WRITE delegation, but should otherwise
    consider servers that hand out duplicate delegations to be borken.

Signed-off-by: Trond Myklebust

SUNRPC: Move clnt->cl_server into struct rpc_xprt

2012-03-02T20:36:41+00:00

When the cl_xprt field is updated, the cl_server field will also have
to change.  Since the contents of cl_server follow the remote endpoint
of cl_xprt, just move that field to the rpc_xprt.

Signed-off-by: Trond Myklebust 
[ cel: simplify check_gss_callback_principal(), whitespace changes ]
[ cel: forward ported to 3.4 ]
Signed-off-by: Chuck Lever 
Signed-off-by: Trond Myklebust

NFS: start printks w/ NFS: even if func shown

2012-02-06T23:48:00+00:00

This patch addresses printks that have some context to show that they are
from fs/nfs/, but for the sake of consistency now start with NFS:

Signed-off-by: Weston Andros Adamson 
Signed-off-by: Trond Myklebust

NFS: create callback transports in parent transport network namespace

2012-01-31T23:20:27+00:00

This patch replaces static "init_net" references with parent transport xprt_net
reference. Thus callback transports will be created in the same network
namespace as respective NFS mount point was created.

Signed-off-by: Stanislav Kinsbursky 
Signed-off-by: Trond Myklebust

sunrpc: use better NUMA affinities

2011-08-19T17:25:36+00:00

Use NUMA aware allocations to reduce latencies and increase throughput.

sunrpc kthreads can use kthread_create_on_node() if pool_mode is
"percpu" or "pernode", and svc_prepare_thread()/svc_init_buffer() can
also take into account NUMA node affinity for memory allocations.

Signed-off-by: Eric Dumazet 
CC: "J. Bruce Fields" 
CC: Neil Brown 
CC: David Miller 
Reviewed-by: Greg Banks 
[bfields@redhat.com: fix up caller nfs41_callback_up]
Signed-off-by: J. Bruce Fields