Commit Graph

352 Commits

Author SHA1 Message Date
Trond Myklebust 829e57d7c5 NFS: Fix a warning in nfs_setsecurity
Fix the following warning:

linux-nfs/fs/nfs/inode.c:315:1: warning: ‘inline’ is not at
beginning of declaration [-Wold-style-declaration]

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-11-19 16:20:41 -05:00
Trond Myklebust fab99ebe39 NFSv4.2: Remove redundant checks in nfs_setsecurity+nfs4_label_init_security
We already check for nfs_server_capable(inode, NFS_CAP_SECURITY_LABEL)
in nfs4_label_alloc()
We check the minor version in _nfs4_server_capabilities before setting
NFS_CAP_SECURITY_LABEL.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-11-04 16:42:52 -05:00
Jeff Layton 3da580aab9 nfs: set security label when revalidating inode
Currently, we fetch the security label when revalidating an inode's
attributes, but don't apply it. This is in contrast to the readdir()
codepath where we do apply label changes.

Cc: Dave Quigley <dpquigl@davequigley.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-11-04 16:42:38 -05:00
Trond Myklebust c698dbf9fe Merge branch 'fscache' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs into linux-next
Pull fs-cache fixes from David Howells:

Can you pull these commits to fix an issue with NFS whereby caching can be
enabled on a file that is open for writing by subsequently opening it for
reading.  This can be made to crash by opening it for writing again if you're
quick enough.

The gist of the patchset is that the cookie should be acquired at inode
creation only and subsequently enabled and disabled as appropriate (which
dispenses with the backing objects when they're not needed).

The extra synchronisation that NFS does can then be dispensed with as it is
thenceforth managed by FS-Cache.

Could you send these on to Linus?

This likely will need fixing also in CIFS and 9P also once the FS-Cache
changes are upstream.  AFS and Ceph are probably safe.

* 'fscache' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  NFS: Use i_writecount to control whether to get an fscache cookie in nfs_open()
  FS-Cache: Provide the ability to enable/disable cookies
  FS-Cache: Add use/unuse/wake cookie wrappers
2013-10-28 19:36:46 -04:00
Chuck Lever 9e6ee76dfb NFS: Export _nfs_display_fhandle()
Allow code in nfsv4.ko to use _nfs_display_fhandle().

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-10-28 15:23:35 -04:00
David Howells f1fe29b4a0 NFS: Use i_writecount to control whether to get an fscache cookie in nfs_open()
Use i_writecount to control whether to get an fscache cookie in nfs_open() as
NFS does not do write caching yet.  I *think* this is the cause of a problem
encountered by Mark Moseley whereby __fscache_uncache_page() gets a NULL
pointer dereference because cookie->def is NULL:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
IP: [<ffffffff812a1903>] __fscache_uncache_page+0x23/0x160
PGD 0
Thread overran stack, or stack corrupted
Oops: 0000 [#1] SMP
Modules linked in: ...
CPU: 7 PID: 18993 Comm: php Not tainted 3.11.1 #1
Hardware name: Dell Inc. PowerEdge R420/072XWF, BIOS 1.3.5 08/21/2012
task: ffff8804203460c0 ti: ffff880420346640
RIP: 0010:[<ffffffff812a1903>] __fscache_uncache_page+0x23/0x160
RSP: 0018:ffff8801053af878 EFLAGS: 00210286
RAX: 0000000000000000 RBX: ffff8800be2f8780 RCX: ffff88022ffae5e8
RDX: 0000000000004c66 RSI: ffffea00055ff440 RDI: ffff8800be2f8780
RBP: ffff8801053af898 R08: 0000000000000001 R09: 0000000000000003
R10: 0000000000000000 R11: 0000000000000000 R12: ffffea00055ff440
R13: 0000000000001000 R14: ffff8800c50be538 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88042fc60000(0063) knlGS:00000000e439c700
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000000000010 CR3: 0000000001d8f000 CR4: 00000000000607f0
Stack:
...
Call Trace:
[<ffffffff81365a72>] __nfs_fscache_invalidate_page+0x42/0x70
[<ffffffff813553d5>] nfs_invalidate_page+0x75/0x90
[<ffffffff811b8f5e>] truncate_inode_page+0x8e/0x90
[<ffffffff811b90ad>] truncate_inode_pages_range.part.12+0x14d/0x620
[<ffffffff81d6387d>] ? __mutex_lock_slowpath+0x1fd/0x2e0
[<ffffffff811b95d3>] truncate_inode_pages_range+0x53/0x70
[<ffffffff811b969d>] truncate_inode_pages+0x2d/0x40
[<ffffffff811b96ff>] truncate_pagecache+0x4f/0x70
[<ffffffff81356840>] nfs_setattr_update_inode+0xa0/0x120
[<ffffffff81368de4>] nfs3_proc_setattr+0xc4/0xe0
[<ffffffff81357f78>] nfs_setattr+0xc8/0x150
[<ffffffff8122d95b>] notify_change+0x1cb/0x390
[<ffffffff8120a55b>] do_truncate+0x7b/0xc0
[<ffffffff8121f96c>] do_last+0xa4c/0xfd0
[<ffffffff8121ffbc>] path_openat+0xcc/0x670
[<ffffffff81220a0e>] do_filp_open+0x4e/0xb0
[<ffffffff8120ba1f>] do_sys_open+0x13f/0x2b0
[<ffffffff8126aaf6>] compat_SyS_open+0x36/0x50
[<ffffffff81d7204c>] sysenter_dispatch+0x7/0x24

The code at the instruction pointer was disassembled:

> (gdb) disas __fscache_uncache_page
> Dump of assembler code for function __fscache_uncache_page:
> ...
> 0xffffffff812a18ff <+31>: mov 0x48(%rbx),%rax
> 0xffffffff812a1903 <+35>: cmpb $0x0,0x10(%rax)
> 0xffffffff812a1907 <+39>: je 0xffffffff812a19cd <__fscache_uncache_page+237>

These instructions make up:

	ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX);

That cmpb is the faulting instruction (%rax is 0).  So cookie->def is NULL -
which presumably means that the cookie has already been at least partway
through __fscache_relinquish_cookie().

What I think may be happening is something like a three-way race on the same
file:

	PROCESS 1	PROCESS 2	PROCESS 3
	===============	===============	===============
	open(O_TRUNC|O_WRONLY)
			open(O_RDONLY)
					open(O_WRONLY)
	-->nfs_open()
	-->nfs_fscache_set_inode_cookie()
	nfs_fscache_inode_lock()
	nfs_fscache_disable_inode_cookie()
	__fscache_relinquish_cookie()
	nfs_inode->fscache = NULL
	<--nfs_fscache_set_inode_cookie()

			-->nfs_open()
			-->nfs_fscache_set_inode_cookie()
			nfs_fscache_inode_lock()
			nfs_fscache_enable_inode_cookie()
			__fscache_acquire_cookie()
			nfs_inode->fscache = cookie
			<--nfs_fscache_set_inode_cookie()
	<--nfs_open()
	-->nfs_setattr()
	...
	...
	-->nfs_invalidate_page()
	-->__nfs_fscache_invalidate_page()
	cookie = nfsi->fscache
					-->nfs_open()
					-->nfs_fscache_set_inode_cookie()
					nfs_fscache_inode_lock()
					nfs_fscache_disable_inode_cookie()
					-->__fscache_relinquish_cookie()
	-->__fscache_uncache_page(cookie)
	<crash>
					<--__fscache_relinquish_cookie()
					nfs_inode->fscache = NULL
					<--nfs_fscache_set_inode_cookie()

What is needed is something to prevent process #2 from reacquiring the cookie
- and I think checking i_writecount should do the trick.

It's also possible to have a two-way race on this if the file is opened
O_TRUNC|O_RDONLY instead.

Reported-by: Mark Moseley <moseleymark@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
2013-09-27 18:40:25 +01:00
Kirill A. Shutemov 7caef26767 truncate: drop 'oldsize' truncate_pagecache() parameter
truncate_pagecache() doesn't care about old size since commit
cedabed49b ("vfs: Fix vmtruncate() regression").  Let's drop it.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-12 15:38:02 -07:00
Linus Torvalds bf97293eb8 Merge tag 'nfs-for-3.12-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
Pull NFS client updates from Trond Myklebust:
 "Highlights include:

   - Fix NFSv4 recovery so that it doesn't recover lost locks in cases
     such as lease loss due to a network partition, where doing so may
     result in data corruption.  Add a kernel parameter to control
     choice of legacy behaviour or not.
   - Performance improvements when 2 processes are writing to the same
     file.
   - Flush data to disk when an RPCSEC_GSS session timeout is imminent.
   - Implement NFSv4.1 SP4_MACH_CRED state protection to prevent other
     NFS clients from being able to manipulate our lease and file
     locking state.
   - Allow sharing of RPCSEC_GSS caches between different rpc clients.
   - Fix the broken NFSv4 security auto-negotiation between client and
     server.
   - Fix rmdir() to wait for outstanding sillyrename unlinks to complete
   - Add a tracepoint framework for debugging NFSv4 state recovery
     issues.
   - Add tracing to the generic NFS layer.
   - Add tracing for the SUNRPC socket connection state.
   - Clean up the rpc_pipefs mount/umount event management.
   - Merge more patches from Chuck in preparation for NFSv4 migration
     support"

* tag 'nfs-for-3.12-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (107 commits)
  NFSv4: use mach cred for SECINFO_NO_NAME w/ integrity
  NFS: nfs_compare_super shouldn't check the auth flavour unless 'sec=' was set
  NFSv4: Allow security autonegotiation for submounts
  NFSv4: Disallow security negotiation for lookups when 'sec=' is specified
  NFSv4: Fix security auto-negotiation
  NFS: Clean up nfs_parse_security_flavors()
  NFS: Clean up the auth flavour array mess
  NFSv4.1 Use MDS auth flavor for data server connection
  NFS: Don't check lock owner compatability unless file is locked (part 2)
  NFS: Don't check lock owner compatibility in writes unless file is locked
  nfs4: Map NFS4ERR_WRONG_CRED to EPERM
  nfs4.1: Add SP4_MACH_CRED write and commit support
  nfs4.1: Add SP4_MACH_CRED stateid support
  nfs4.1: Add SP4_MACH_CRED secinfo support
  nfs4.1: Add SP4_MACH_CRED cleanup support
  nfs4.1: Add state protection handler
  nfs4.1: Minimal SP4_MACH_CRED implementation
  SUNRPC: Replace pointer values with task->tk_pid and rpc_clnt->cl_clid
  SUNRPC: Add an identifier for struct rpc_clnt
  SUNRPC: Ensure rpc_task->tk_pid is available for tracepoints
  ...
2013-09-09 09:19:15 -07:00
Trond Myklebust f4ce1299b3 NFS: Add event tracing for generic NFS events
Add tracepoints for inode attribute updates, attribute revalidation,
writeback start/end fsync start/end, attribute change start/end,
permission check start/end.

The intention is to enable performance tracing using 'perf'as well as
improving debugging.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-08-22 08:58:17 -04:00
Trond Myklebust 1264a2f053 NFS: refactor code for calculating the crc32 hash of a filehandle
We want to be able to display the crc32 hash of the filehandle in
tracepoints.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-08-22 08:58:16 -04:00
Trond Myklebust eddffa4084 NFS: Remove unnecessary call to nfs_setsecurity in nfs_fhget()
We only need to call it on the creation of the inode.

Reported-by: Julia Lawall <Julia.Lawall@lip6.fr>
Cc: Steve Dickson <SteveD@redhat.com>
Cc: Dave Quigley <dpquigl@davequigley.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-08-07 17:07:41 -04:00
Trond Myklebust f8806c843f NFS: Fix writeback performance issue on cache invalidation
If a cache invalidation is triggered, and we happen to have a lot of
writebacks cached at the time, then the call to invalidate_inode_pages2()
will end up calling ->launder_page() on each and every dirty page in order
to sync its contents to disk, thus defeating write coalescing.
The following patch ensures that we try to sync the inode to disk before
calling invalidate_inode_pages2() so that we do the writeback as efficiently
as possible.

Reported-by: William Dauchy <william@gandi.net>
Reported-by: Pascal Bouchareine <pascal@gandi.net>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Tested-by: William Dauchy <william@gandi.net>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
2013-08-07 17:07:40 -04:00
Scott Mayhew 43f291cd07 NFS: Make nfs_attribute_cache_expired() non-static
NFS: Make nfs_attribute_cache_expired() non-static so we can call it from
nfs_readdir().

Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-07-09 17:17:07 -04:00
Linus Torvalds be0c5d8c0b Merge tag 'nfs-for-3.11-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
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
  ...
2013-07-09 12:09:43 -07:00
Trond Myklebust 959d921f5e Merge branch 'labeled-nfs' into linux-next
* labeled-nfs:
  NFS: Apply v4.1 capabilities to v4.2
  NFS: Add in v4.2 callback operation
  NFS: Make callbacks minor version generic
  Kconfig: Add Kconfig entry for Labeled NFS V4 client
  NFS: Extend NFS xattr handlers to accept the security namespace
  NFS: Client implementation of Labeled-NFS
  NFS: Add label lifecycle management
  NFS:Add labels to client function prototypes
  NFSv4: Extend fattr bitmaps to support all 3 words
  NFSv4: Introduce new label structure
  NFSv4: Add label recommended attribute and NFSv4 flags
  NFSv4.2: Added NFS v4.2 support to the NFS client
  SELinux: Add new labeling type native labels
  LSM: Add flags field to security_sb_set_mnt_opts for in kernel mount data.
  Security: Add Hook to test if the particular xattr is part of a MAC model.
  Security: Add hook to calculate context based on a negative dentry.
  NFS: Add NFSv4.2 protocol constants

Conflicts:
	fs/nfs/nfs4proc.c
2013-06-28 16:29:51 -04:00
Trond Myklebust c8d74d9b68 NFSv4: Move the DNS resolver into the NFSv4 module
The other protocols don't use it, so make it local to NFSv4, and
remove the EXPORT.
Also ensure that we only compile in cache_lib.o if we're using
the legacy DNS resolver.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Bryan Schumaker <bjschuma@netapp.com>
2013-06-18 13:47:18 -04:00
David Quigley aa9c266962 NFS: Client implementation of Labeled-NFS
This patch implements the client transport and handling support for labeled
NFS. The patch adds two functions to encode and decode the security label
recommended attribute which makes use of the LSM hooks added earlier. It also
adds code to grab the label from the file attribute structures and encode the
label to be sent back to the server.

Acked-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: Matthew N. Dodd <Matthew.Dodd@sparta.com>
Signed-off-by: Miguel Rodel Felipe <Rodel_FM@dsi.a-star.edu.sg>
Signed-off-by: Phua Eu Gene <PHUA_Eu_Gene@dsi.a-star.edu.sg>
Signed-off-by: Khin Mi Mi Aung <Mi_Mi_AUNG@dsi.a-star.edu.sg>
Signed-off-by: Steve Dickson <steved@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-06-08 16:20:16 -04:00
David Quigley 14c43f7678 NFS: Add label lifecycle management
This patch adds the lifecycle management for the security label structure
introduced in an earlier patch. The label is not used yet but allocations and
freeing of the structure is handled.

Signed-off-by: Matthew N. Dodd <Matthew.Dodd@sparta.com>
Signed-off-by: Miguel Rodel Felipe <Rodel_FM@dsi.a-star.edu.sg>
Signed-off-by: Phua Eu Gene <PHUA_Eu_Gene@dsi.a-star.edu.sg>
Signed-off-by: Khin Mi Mi Aung <Mi_Mi_AUNG@dsi.a-star.edu.sg>
Signed-off-by: Steve Dickson <steved@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-06-08 16:20:15 -04:00
David Quigley 1775fd3e80 NFS:Add labels to client function prototypes
After looking at all of the nfsv4 operations the label structure has been added
to the prototypes of the functions which can transmit label data.

Signed-off-by: Matthew N. Dodd <Matthew.Dodd@sparta.com>
Signed-off-by: Miguel Rodel Felipe <Rodel_FM@dsi.a-star.edu.sg>
Signed-off-by: Phua Eu Gene <PHUA_Eu_Gene@dsi.a-star.edu.sg>
Signed-off-by: Khin Mi Mi Aung <Mi_Mi_AUNG@dsi.a-star.edu.sg>
Signed-off-by: Steve Dickson <steved@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-06-08 16:20:15 -04:00
Steve Dickson e058f70b80 NFSv4: Introduce new label structure
In order to mimic the way that NFSv4 ACLs are implemented we have created a
structure to be used to pass label data up and down the call chain. This patch
adds the new structure and new members to the required NFSv4 call structures.

Signed-off-by: Matthew N. Dodd <Matthew.Dodd@sparta.com>
Signed-off-by: Miguel Rodel Felipe <Rodel_FM@dsi.a-star.edu.sg>
Signed-off-by: Phua Eu Gene <PHUA_Eu_Gene@dsi.a-star.edu.sg>
Signed-off-by: Khin Mi Mi Aung <Mi_Mi_AUNG@dsi.a-star.edu.sg>
Signed-off-by: Steve Dickson <steved@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-06-08 16:20:14 -04:00
Trond Myklebust c45ffdd269 NFSv4: Close another NFSv4 recovery race
State recovery currently relies on being able to find a valid
nfs_open_context in the inode->open_files list.
We therefore need to put the nfs_open_context on the list while
we're still protected by the sp->so_reclaim_seqcount in order
to avoid reboot races.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-06-06 16:24:44 -04:00
Colin Cross 416ad3c9c0 freezer: add unsafe versions of freezable helpers for NFS
NFS calls the freezable helpers with locks held, which is unsafe
and will cause lockdep warnings when 6aa9707 "lockdep: check
that no locks held at freeze time" is reapplied (it was reverted
in dbf520a).  NFS shouldn't be doing this, but it has
long-running syscalls that must hold a lock but also shouldn't
block suspend.  Until NFS freeze handling is rewritten to use a
signal to exit out of the critical section, add new *_unsafe
versions of the helpers that will not run the lockdep test when
6aa9707 is reapplied, and call them from NFS.

In practice the likley result of holding the lock while freezing
is that a second task blocked on the lock will never freeze,
aborting suspend, but it is possible to manufacture a case using
the cgroup freezer, the lock, and the suspend freezer to create
a deadlock.  Silencing the lockdep warning here will allow
problems to be found in other drivers that may have a more
serious deadlock risk, and prevent new problems from being added.

Signed-off-by: Colin Cross <ccross@android.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-05-12 14:16:21 +02:00
Trond Myklebust 577b42327d NFS: Add functionality to allow waiting on all outstanding reads to complete
This will later allow NFS locking code to wait for readahead to complete
before releasing byte range locks.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-04-08 22:12:33 -04:00
Trond Myklebust 8c86899f62 NFS: __nfs_find_lock_context needs to check ctx->lock_context for a match too
Currently, we're forcing an unnecessary duplication of the
initial nfs_lock_context in calls to nfs_get_lock_context, since
__nfs_find_lock_context ignores the ctx->lock_context.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-03-25 12:04:10 -04:00
Linus Torvalds 8d05b3771d Merge tag 'nfs-for-3.9-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
Pull NFS client bugfixes from Trond Myklebust:
 "We've just concluded another Connectathon interoperability testing
  week, and so here are the fixes for the bugs that were discovered:

   - Don't allow NFS silly-renamed files to be deleted
   - Don't start the retransmission timer when out of socket space
   - Fix a couple of pnfs-related Oopses.
   - Fix one more NFSv4 state recovery deadlock
   - Don't loop forever when LAYOUTGET returns NFS4ERR_LAYOUTTRYLATER"

* tag 'nfs-for-3.9-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  SUNRPC: One line comment fix
  NFSv4.1: LAYOUTGET EDELAY loops timeout to the MDS
  SUNRPC: add call to get configured timeout
  PNFS: set the default DS timeout to 60 seconds
  NFSv4: Fix another open/open_recovery deadlock
  nfs: don't allow nfs_find_actor to match inodes of the wrong type
  NFSv4.1: Hold reference to layout hdr in layoutget
  pnfs: fix resend_to_mds for directio
  SUNRPC: Don't start the retransmission timer when out of socket space
  NFS: Don't allow NFS silly-renamed files to be deleted, no signal
2013-03-02 16:46:07 -08:00