linux-toradex.git/net/sunrpc/sched.c, branch v3.19-rc1

sunrpc: eliminate RPC_TRACEPOINTS

2014-11-24T22:33:12+00:00

It's always set to the same value as CONFIG_TRACEPOINTS, so we can just
use that instead.

Signed-off-by: Jeff Layton 
Signed-off-by: Trond Myklebust

sunrpc: eliminate RPC_DEBUG

2014-11-24T22:31:46+00:00

It's always set to whatever CONFIG_SUNRPC_DEBUG is, so just use that.

Signed-off-by: Jeff Layton 
Signed-off-by: Trond Myklebust

NFS/SUNRPC: Remove other deadlock-avoidance mechanisms in nfs_release_page()

2014-09-25T12:25:47+00:00

Now that nfs_release_page() doesn't block indefinitely, other deadlock
avoidance mechanisms aren't needed.
 - it doesn't hurt for kswapd to block occasionally.  If it doesn't
   want to block it would clear __GFP_WAIT.  The current_is_kswapd()
   was only added to avoid deadlocks and we have a new approach for
   that.
 - memory allocation in the SUNRPC layer can very rarely try to
   ->releasepage() a page it is trying to handle.  The deadlock
   is removed as nfs_release_page() doesn't block indefinitely.

So we don't need to set PF_FSTRANS for sunrpc network operations any
more.

Signed-off-by: NeilBrown 
Acked-by: Jeff Layton 
Signed-off-by: Trond Myklebust

sched: Allow wait_on_bit_action() functions to support a timeout

2014-07-16T13:10:41+00:00

It is currently not possible for various wait_on_bit functions
to implement a timeout.

While the "action" function that is called to do the waiting
could certainly use schedule_timeout(), there is no way to carry
forward the remaining timeout after a false wake-up.
As false-wakeups a clearly possible at least due to possible
hash collisions in bit_waitqueue(), this is a real problem.

The 'action' function is currently passed a pointer to the word
containing the bit being waited on.  No current action functions
use this pointer.  So changing it to something else will be a
little noisy but will have no immediate effect.

This patch changes the 'action' function to take a pointer to
the "struct wait_bit_key", which contains a pointer to the word
containing the bit so nothing is really lost.

It also adds a 'private' field to "struct wait_bit_key", which
is initialized to zero.

An action function can now implement a timeout with something
like

static int timed_out_waiter(struct wait_bit_key *key)
{
	unsigned long waited;
	if (key->private == 0) {
		key->private = jiffies;
		if (key->private == 0)
			key->private -= 1;
	}
	waited = jiffies - key->private;
	if (waited > 10 * HZ)
		return -EAGAIN;
	schedule_timeout(waited - 10 * HZ);
	return 0;
}

If any other need for context in a waiter were found it would be
easy to use ->private for some other purpose, or even extend
"struct wait_bit_key".

My particular need is to support timeouts in nfs_release_page()
to avoid deadlocks with loopback mounted NFS.

While wait_on_bit_timeout() would be a cleaner interface, it
will not meet my need.  I need the timeout to be sensitive to
the state of the connection with the server, which could change.
 So I need to use an 'action' interface.

Signed-off-by: NeilBrown 
Acked-by: Peter Zijlstra 
Cc: Oleg Nesterov 
Cc: Steve French 
Cc: David Howells 
Cc: Steven Whitehouse 
Cc: Linus Torvalds 
Link: http://lkml.kernel.org/r/20140707051604.28027.41257.stgit@notabene.brown
Signed-off-by: Ingo Molnar

net, sunrpc: suppress allocation warning in rpc_malloc()

2014-05-29T15:11:51+00:00

rpc_malloc() allocates with GFP_NOWAIT without making any attempt at
reclaim so it easily fails when low on memory.  This ends up spamming the
kernel log:

SLAB: Unable to allocate memory on node 0 (gfp=0x4000)
  cache: kmalloc-8192, object size: 8192, order: 1
  node 0: slabs: 207/207, objs: 207/207, free: 0
rekonq: page allocation failure: order:1, mode:0x204000
CPU: 2 PID: 14321 Comm: rekonq Tainted: G           O  3.15.0-rc3-12.gfc9498b-desktop+ #6
Hardware name: System manufacturer System Product Name/M4A785TD-V EVO, BIOS 2105    07/23/2010
 0000000000000000 ffff880010ff17d0 ffffffff815e693c 0000000000204000
 ffff880010ff1858 ffffffff81137bd2 0000000000000000 0000001000000000
 ffff88011ffebc38 0000000000000001 0000000000204000 ffff88011ffea000
Call Trace:
 [] dump_stack+0x4d/0x6f
 [] warn_alloc_failed+0xd2/0x140
 [] __alloc_pages_nodemask+0x7e9/0xa30
 [] kmem_getpages+0x58/0x140
 [] fallback_alloc+0x1d6/0x210
 [] ____cache_alloc_node+0x123/0x150
 [] __kmalloc+0x203/0x490
 [] rpc_malloc+0x32/0xa0 [sunrpc]
 [] call_allocate+0xb9/0x170 [sunrpc]
 [] __rpc_execute+0x88/0x460 [sunrpc]
 [] rpc_execute+0x59/0xc0 [sunrpc]
 [] rpc_run_task+0x6b/0x90 [sunrpc]
 [] nfs4_call_sync_sequence+0x51/0x80 [nfsv4]
 [] _nfs4_do_setattr+0x1ed/0x280 [nfsv4]
 [] nfs4_do_setattr+0x72/0x180 [nfsv4]
 [] nfs4_proc_setattr+0xbc/0x140 [nfsv4]
 [] nfs_setattr+0xd8/0x240 [nfs]
 [] notify_change+0x231/0x380
 [] chmod_common+0xfc/0x120
 [] SyS_chmod+0x40/0x90
 [] system_call_fastpath+0x1a/0x1f
...

If the allocation fails, simply return NULL and avoid spamming the kernel
log.

Reported-by: Marc Dietrich 
Signed-off-by: David Rientjes 
Signed-off-by: Trond Myklebust

SUNRPC: Don't let rpc_delay() clobber non-timeout errors

2014-03-20T17:38:43+00:00

Signed-off-by: Trond Myklebust

SUNRPC: Ensure rpc_task->tk_pid is available for tracepoints

2013-09-04T18:45:13+00:00

Signed-off-by: Trond Myklebust

Merge tag 'nfs-for-3.11-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

2013-07-09T19:09:43+00:00

Pull NFS client updates from Trond Myklebust:
 "Feature highlights include:
   - Add basic client support for NFSv4.2
   - Add basic client support for Labeled NFS (selinux for NFSv4.2)
   - Fix the use of credentials in NFSv4.1 stateful operations, and add
     support for NFSv4.1 state protection.

  Bugfix highlights:
   - Fix another NFSv4 open state recovery race
   - Fix an NFSv4.1 back channel session regression
   - Various rpc_pipefs races
   - Fix another issue with NFSv3 auth negotiation

  Please note that Labeled NFS does require some additional support from
  the security subsystem.  The relevant changesets have all been
  reviewed and acked by James Morris."

* tag 'nfs-for-3.11-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (54 commits)
  NFS: Set NFS_CS_MIGRATION for NFSv4 mounts
  NFSv4.1 Refactor nfs4_init_session and nfs4_init_channel_attrs
  nfs: have NFSv3 try server-specified auth flavors in turn
  nfs: have nfs_mount fake up a auth_flavs list when the server didn't provide it
  nfs: move server_authlist into nfs_try_mount_request
  nfs: refactor "need_mount" code out of nfs_try_mount
  SUNRPC: PipeFS MOUNT notification optimization for dying clients
  SUNRPC: split client creation routine into setup and registration
  SUNRPC: fix races on PipeFS UMOUNT notifications
  SUNRPC: fix races on PipeFS MOUNT notifications
  NFSv4.1 use pnfs_device maxcount for the objectlayout gdia_maxcount
  NFSv4.1 use pnfs_device maxcount for the blocklayout gdia_maxcount
  NFSv4.1 Fix gdia_maxcount calculation to fit in ca_maxresponsesize
  NFS: Improve legacy idmapping fallback
  NFSv4.1 end back channel session draining
  NFS: Apply v4.1 capabilities to v4.2
  NFSv4.1: Clean up layout segment comparison helper names
  NFSv4.1: layout segment comparison helpers should take 'const' parameters
  NFSv4: Move the DNS resolver into the NFSv4 module
  rpc_pipefs: only set rpc_dentry_ops if d_op isn't already set
  ...

Merge branch 'freezer'

2013-06-28T11:00:53+00:00

* freezer:
  af_unix: use freezable blocking calls in read
  sigtimedwait: use freezable blocking call
  nanosleep: use freezable blocking call
  futex: use freezable blocking call
  select: use freezable blocking call
  epoll: use freezable blocking call
  binder: use freezable blocking calls
  freezer: add new freezable helpers using freezer_do_not_count()
  freezer: convert freezable helpers to static inline where possible
  freezer: convert freezable helpers to freezer_do_not_count()
  freezer: skip waking up tasks with PF_FREEZER_SKIP set
  freezer: shorten freezer sleep time using exponential backoff
  lockdep: check that no locks held at freeze time
  lockdep: remove task argument from debug_check_no_locks_held
  freezer: add unsafe versions of freezable helpers for CIFS
  freezer: add unsafe versions of freezable helpers for NFS

SUNRPC: Remove redundant call to rpc_set_running() in __rpc_execute()

2013-06-06T20:24:40+00:00

The RPC_TASK_RUNNING flag will always have been set in rpc_make_runnable()
once we get past the test for out_of_line_wait_on_bit() returning
ERESTARTSYS.

Signed-off-by: Trond Myklebust