Commit Graph

1446 Commits

Author SHA1 Message Date
Linus Torvalds 18bce371ae Merge branch 'for-2.6.38' of git://linux-nfs.org/~bfields/linux
* 'for-2.6.38' of git://linux-nfs.org/~bfields/linux: (62 commits)
  nfsd4: fix callback restarting
  nfsd: break lease on unlink, link, and rename
  nfsd4: break lease on nfsd setattr
  nfsd: don't support msnfs export option
  nfsd4: initialize cb_per_client
  nfsd4: allow restarting callbacks
  nfsd4: simplify nfsd4_cb_prepare
  nfsd4: give out delegations more quickly in 4.1 case
  nfsd4: add helper function to run callbacks
  nfsd4: make sure sequence flags are set after destroy_session
  nfsd4: re-probe callback on connection loss
  nfsd4: set sequence flag when backchannel is down
  nfsd4: keep finer-grained callback status
  rpc: allow xprt_class->setup to return a preexisting xprt
  rpc: keep backchannel xprt as long as server connection
  rpc: move sk_bc_xprt to svc_xprt
  nfsd4: allow backchannel recovery
  nfsd4: support BIND_CONN_TO_SESSION
  nfsd4: modify session list under cl_lock
  Documentation: fl_mylease no longer exists
  ...

Fix up conflicts in fs/nfsd/vfs.c with the vfs-scale work.  The
vfs-scale work touched some msnfs cases, and this merge removes support
for that entirely, so the conflict was trivial to resolve.
2011-01-14 13:17:26 -08:00
Linus Torvalds b9d919a4ac Merge branch 'nfs-for-2.6.38' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6
* 'nfs-for-2.6.38' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6: (89 commits)
  NFS fix the setting of exchange id flag
  NFS: Don't use vm_map_ram() in readdir
  NFSv4: Ensure continued open and lockowner name uniqueness
  NFS: Move cl_delegations to the nfs_server struct
  NFS: Introduce nfs_detach_delegations()
  NFS: Move cl_state_owners and related fields to the nfs_server struct
  NFS: Allow walking nfs_client.cl_superblocks list outside client.c
  pnfs: layout roc code
  pnfs: update nfs4_callback_recallany to handle layouts
  pnfs: add CB_LAYOUTRECALL handling
  pnfs: CB_LAYOUTRECALL xdr code
  pnfs: change lo refcounting to atomic_t
  pnfs: check that partial LAYOUTGET return is ignored
  pnfs: add layout to client list before sending rpc
  pnfs: serialize LAYOUTGET(openstateid)
  pnfs: layoutget rpc code cleanup
  pnfs: change how lsegs are removed from layout list
  pnfs: change layout state seqlock to a spinlock
  pnfs: add prefix to struct pnfs_layout_hdr fields
  pnfs: add prefix to struct pnfs_layout_segment fields
  ...
2011-01-11 15:11:56 -08:00
J. Bruce Fields f0418aa4b1 rpc: allow xprt_class->setup to return a preexisting xprt
This allows us to reuse the xprt associated with a server connection if
one has already been set up.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-01-11 15:04:10 -05:00
J. Bruce Fields 99de8ea962 rpc: keep backchannel xprt as long as server connection
Multiple backchannels can share the same tcp connection; from rfc 5661 section
2.10.3.1:

	A connection's association with a session is not exclusive.  A
	connection associated with the channel(s) of one session may be
	simultaneously associated with the channel(s) of other sessions
	including sessions associated with other client IDs.

However, multiple backchannels share a connection, they must all share
the same xid stream (hence the same rpc_xprt); the only way we have to
match replies with calls at the rpc layer is using the xid.

So, keep the rpc_xprt around as long as the connection lasts, in case
we're asked to use the connection as a backchannel again.

Requests to create new backchannel clients over a given server
connection should results in creating new clients that reuse the
existing rpc_xprt.

But to start, just reject attempts to associate multiple rpc_xprt's with
the same underlying bc_xprt.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-01-11 15:04:10 -05:00
J. Bruce Fields d75faea330 rpc: move sk_bc_xprt to svc_xprt
This seems obviously transport-level information even if it's currently
used only by the server socket code.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-01-11 15:04:10 -05:00
Trond Myklebust 68c404b18f Merge branch 'bugfixes' into nfs-for-2.6.38
Conflicts:
	fs/nfs/nfs2xdr.c
	fs/nfs/nfs3xdr.c
	fs/nfs/nfs4xdr.c
2011-01-10 14:48:02 -05:00
Trond Myklebust 6650239a4b NFS: Don't use vm_map_ram() in readdir
vm_map_ram() is not available on NOMMU platforms, and causes trouble
on incoherrent architectures such as ARM when we access the page data
through both the direct and the virtual mapping.

The alternative is to use the direct mapping to access page data
for the case when we are not crossing a page boundary, but to copy
the data into a linear scratch buffer when we are accessing data
that spans page boundaries.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Tested-by: Marc Kleine-Budde <mkl@pengutronix.de>
Cc: stable@kernel.org  [2.6.37]
2011-01-10 14:45:01 -05:00
Linus Torvalds 23d69b09b7 Merge branch 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
* 'for-2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (33 commits)
  usb: don't use flush_scheduled_work()
  speedtch: don't abuse struct delayed_work
  media/video: don't use flush_scheduled_work()
  media/video: explicitly flush request_module work
  ioc4: use static work_struct for ioc4_load_modules()
  init: don't call flush_scheduled_work() from do_initcalls()
  s390: don't use flush_scheduled_work()
  rtc: don't use flush_scheduled_work()
  mmc: update workqueue usages
  mfd: update workqueue usages
  dvb: don't use flush_scheduled_work()
  leds-wm8350: don't use flush_scheduled_work()
  mISDN: don't use flush_scheduled_work()
  macintosh/ams: don't use flush_scheduled_work()
  vmwgfx: don't use flush_scheduled_work()
  tpm: don't use flush_scheduled_work()
  sonypi: don't use flush_scheduled_work()
  hvsi: don't use flush_scheduled_work()
  xen: don't use flush_scheduled_work()
  gdrom: don't use flush_scheduled_work()
  ...

Fixed up trivial conflict in drivers/media/video/bt8xx/bttv-input.c
as per Tejun.
2011-01-07 16:58:04 -08:00
Linus Torvalds b4a45f5fe8 Merge branch 'vfs-scale-working' of git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin
* 'vfs-scale-working' of git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin: (57 commits)
  fs: scale mntget/mntput
  fs: rename vfsmount counter helpers
  fs: implement faster dentry memcmp
  fs: prefetch inode data in dcache lookup
  fs: improve scalability of pseudo filesystems
  fs: dcache per-inode inode alias locking
  fs: dcache per-bucket dcache hash locking
  bit_spinlock: add required includes
  kernel: add bl_list
  xfs: provide simple rcu-walk ACL implementation
  btrfs: provide simple rcu-walk ACL implementation
  ext2,3,4: provide simple rcu-walk ACL implementation
  fs: provide simple rcu-walk generic_check_acl implementation
  fs: provide rcu-walk aware permission i_ops
  fs: rcu-walk aware d_revalidate method
  fs: cache optimise dentry and inode for rcu-walk
  fs: dcache reduce branches in lookup path
  fs: dcache remove d_mounted
  fs: fs_struct use seqlock
  fs: rcu-walk for path lookup
  ...
2011-01-07 08:56:33 -08:00
Nick Piggin fb045adb99 fs: dcache reduce branches in lookup path
Reduce some branches and memory accesses in dcache lookup by adding dentry
flags to indicate common d_ops are set, rather than having to check them.
This saves a pointer memory access (dentry->d_op) in common path lookup
situations, and saves another pointer load and branch in cases where we
have d_op but not the particular operation.

Patched with:

git grep -E '[.>]([[:space:]])*d_op([[:space:]])*=' | xargs sed -e 's/\([^\t ]*\)->d_op = \(.*\);/d_set_d_op(\1, \2);/' -e 's/\([^\t ]*\)\.d_op = \(.*\);/d_set_d_op(\&\1, \2);/' -i

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:28 +11:00
Nick Piggin fa0d7e3de6 fs: icache RCU free inodes
RCU free the struct inode. This will allow:

- Subsequent store-free path walking patch. The inode must be consulted for
  permissions when walking, so an RCU inode reference is a must.
- sb_inode_list_lock to be moved inside i_lock because sb list walkers who want
  to take i_lock no longer need to take sb_inode_list_lock to walk the list in
  the first place. This will simplify and optimize locking.
- Could remove some nested trylock loops in dcache code
- Could potentially simplify things a bit in VM land. Do not need to take the
  page lock to follow page->mapping.

The downsides of this is the performance cost of using RCU. In a simple
creat/unlink microbenchmark, performance drops by about 10% due to inability to
reuse cache-hot slab objects. As iterations increase and RCU freeing starts
kicking over, this increases to about 20%.

In cases where inode lifetimes are longer (ie. many inodes may be allocated
during the average life span of a single inode), a lot of this cache reuse is
not applicable, so the regression caused by this patch is smaller.

The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU,
however this adds some complexity to list walking and store-free path walking,
so I prefer to implement this at a later date, if it is shown to be a win in
real situations. I haven't found a regression in any non-micro benchmark so I
doubt it will be a problem.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:26 +11:00
Nick Piggin fe15ce446b fs: change d_delete semantics
Change d_delete from a dentry deletion notification to a dentry caching
advise, more like ->drop_inode. Require it to be constant and idempotent,
and not take d_lock. This is how all existing filesystems use the callback
anyway.

This makes fine grained dentry locking of dput and dentry lru scanning
much simpler.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:18 +11:00
Andy Adamson 4a19de0f4b NFS rename client back channel transport field
Differentiate from server backchannel

Signed-off-by: Andy Adamson <andros@netapp.com>
Acked-by: Bruce Fields <bfields@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-01-06 14:46:25 -05:00
Andy Adamson 2c2618c6f2 NFS associate sessionid with callback connection
The sessions based callback service is started prior to the CREATE_SESSION call
so that it can handle CB_NULL requests which can be sent before the
CREATE_SESSION call returns and the session ID is known.

Set the callback sessionid after a sucessful CREATE_SESSION.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-01-06 14:46:24 -05:00
Andy Adamson 16b2d1e1d1 SUNRPC register and unregister the back channel transport
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-01-06 14:46:23 -05:00
Andy Adamson 1f11a034cd SUNRPC new transport for the NFSv4.1 shared back channel
Move the current sock create and destroy routines into the new transport ops.
Back channel socket will be destroyed by the svc_closs_all call in svc_destroy.

Added check: only TCP supported on shared back channel.

Signed-off-by: Andy Adamson <andros@netapp.com>
Acked-by: Bruce Fields <bfields@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-01-06 14:46:23 -05:00
Andy Adamson 71e161a6a9 SUNRPC fix bc_send print
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-01-06 14:46:23 -05:00
Andy Adamson 4b5b3ba16b SUNRPC move svc_drop to caller of svc_process_common
The NFSv4.1 shared back channel does not need to call svc_drop because the
callback service never outlives the single connection it services, and it
reuses it's buffers and keeps the trasport.

Signed-off-by: Andy Adamson <andros@netapp.com>
Acked-by: Bruce Fields <bfields@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-01-06 14:46:23 -05:00
J. Bruce Fields fdef7aa5d4 svcrpc: ensure cache_check caller sees updated entry
Supposes cache_check runs simultaneously with an update on a different
CPU:

	cache_check			task doing update
	^^^^^^^^^^^			^^^^^^^^^^^^^^^^^

	1. test for CACHE_VALID		1'. set entry->data
	   & !CACHE_NEGATIVE

	2. use entry->data		2'. set CACHE_VALID

If the two memory writes performed in step 1' and 2' appear misordered
with respect to the reads in step 1 and 2, then the caller could get
stale data at step 2 even though it saw CACHE_VALID set on the cache
entry.

Add memory barriers to prevent this.

Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-01-04 16:49:25 -05:00
J. Bruce Fields 6bab93f87e svcrpc: take lock on turning entry NEGATIVE in cache_check
We attempt to turn a cache entry negative in place.  But that entry may
already have been filled in by some other task since we last checked
whether it was valid, so we could be modifying an already-valid entry.
If nothing else there's a likely leak in such a case when the entry is
eventually put() and contents are not freed because it has
CACHE_NEGATIVE set.

So, take the cache_lock just as sunrpc_cache_update() does.

Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-01-04 16:49:24 -05:00
J. Bruce Fields 9e701c6109 svcrpc: simpler request dropping
Currently we use -EAGAIN returns to determine when to drop a deferred
request.  On its own, that is error-prone, as it makes us treat -EAGAIN
returns from other functions specially to prevent inadvertent dropping.

So, use a flag on the request instead.

Returning an error on request deferral is still required, to prevent
further processing, but we no longer need worry that an error return on
its own could result in a drop.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-01-04 16:49:22 -05:00
J. Bruce Fields d76d1815f3 svcrpc: avoid double reply caused by deferral race
Commit d29068c431 "sunrpc: Simplify cache_defer_req and related
functions." asserted that cache_check() could determine success or
failure of cache_defer_req() by checking the CACHE_PENDING bit.

This isn't quite right.

We need to know whether cache_defer_req() created a deferred request,
in which case sending an rpc reply has become the responsibility of the
deferred request, and it is important that we not send our own reply,
resulting in two different replies to the same request.

And the CACHE_PENDING bit doesn't tell us that; we could have
succesfully created a deferred request at the same time as another
thread cleared the CACHE_PENDING bit.

So, partially revert that commit, to ensure that cache_check() returns
-EAGAIN if and only if a deferred request has been created.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Acked-by: NeilBrown <neilb@suse.de>
2011-01-04 16:49:21 -05:00
J. Bruce Fields bdd5f05d91 SUNRPC: Remove more code when NFSD_DEPRECATED is not configured
Signed-off-by: NeilBrown <neilb@suse.de>
[bfields@redhat.com: moved svcauth_unix_purge outside ifdef's.]
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-01-04 16:48:02 -05:00
J. Bruce Fields 31f7aa65f5 svcrpc: modifying valid sunrpc cache entries is racy
Once a sunrpc cache entry is VALID, we should be replacing it (and
allowing any concurrent users to destroy it on last put) instead of
trying to update it in place.

Otherwise someone referencing the ip_map we're modifying here could try
to use the m_client just as we're putting the last reference.

The bug should only be seen by users of the legacy nfsd interfaces.

(Thanks to Neil for suggestion to use sunrpc_invalidate.)

Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-01-04 16:47:29 -05:00
Trond Myklebust beb0f0a9fb kernel panic when mount NFSv4
On Tue, 2010-12-14 at 16:58 +0800, Mi Jinlong wrote:
> Hi,
>
> When testing NFSv4 at RHEL6 with kernel 2.6.32, I got a kernel panic
> at NFS client's __rpc_create_common function.
>
> The panic place is:
>   rpc_mkpipe
>     __rpc_lookup_create()          <=== find pipefile *idmap*
>     __rpc_mkpipe()                 <=== pipefile is *idmap*
>       __rpc_create_common()
>        ******  BUG_ON(!d_unhashed(dentry)); ******    *panic*
>
> It means that the dentry's d_flags have be set DCACHE_UNHASHED,
> but it should not be set here.
>
> Is someone known this bug? or give me some idea?
>
> A reproduce program is append, but it can't reproduce the bug every time.
> the export is: "/nfsroot       *(rw,no_root_squash,fsid=0,insecure)"
>
> And the panic message is append.
>
> ============================================================================
> #!/bin/sh
>
> LOOPTOTAL=768
> LOOPCOUNT=0
> ret=0
>
> while [ $LOOPCOUNT -ne $LOOPTOTAL ]
> do
> 	((LOOPCOUNT += 1))
> 	service nfs restart
> 	/usr/sbin/rpc.idmapd
> 	mount -t nfs4 127.0.0.1:/ /mnt|| return 1;
> 	ls -l /var/lib/nfs/rpc_pipefs/nfs/*/
> 	umount /mnt
> 	echo $LOOPCOUNT
> done
>
> ===============================================================================
> Code: af 60 01 00 00 89 fa 89 f0 e8 64 cf 89 f0 e8 5c 7c 64 cf 31 c0 8b 5c 24 10 8b
> 74 24 14 8b 7c 24 18 8b 6c 24 1c 83 c4 20 c3 <0f> 0b eb fc 8b 46 28 c7 44 24 08 20
> de ee f0 c7 44 24 04 56 ea
> EIP:[<f0ee92ea>] __rpc_create_common+0x8a/0xc0 [sunrpc] SS:ESP 0068:eccb5d28
> ---[ end trace 8f5606cd08928ed2]---
> Kernel panic - not syncing: Fatal exception
> Pid:7131, comm: mount.nfs4 Tainted: G     D   -------------------2.6.32 #1
> Call Trace:
>  [<c080ad18>] ? panic+0x42/0xed
>  [<c080e42c>] ? oops_end+0xbc/0xd0
>  [<c040b090>] ? do_invalid_op+0x0/0x90
>  [<c040b10f>] ? do_invalid_op+0x7f/0x90
>  [<f0ee92ea>] ? __rpc_create_common+0x8a/0xc0[sunrpc]
>  [<f0edc433>] ? rpc_free_task+0x33/0x70[sunrpc]
>  [<f0ed6508>] ? prc_call_sync+0x48/0x60[sunrpc]
>  [<f0ed656e>] ? rpc_ping+0x4e/0x60[sunrpc]
>  [<f0ed6eaf>] ? rpc_create+0x38f/0x4f0[sunrpc]
>  [<c080d80b>] ? error_code+0x73/0x78
>  [<f0ee92ea>] ? __rpc_create_common+0x8a/0xc0[sunrpc]
>  [<c0532bda>] ? d_lookup+0x2a/0x40
>  [<f0ee94b1>] ? rpc_mkpipe+0x111/0x1b0[sunrpc]
>  [<f10a59f4>] ? nfs_create_rpc_client+0xb4/0xf0[nfs]
>  [<f10d6c6d>] ? nfs_fscache_get_client_cookie+0x1d/0x50[nfs]
>  [<f10d3fcb>] ? nfs_idmap_new+0x7b/0x140[nfs]
>  [<c05e76aa>] ? strlcpy+0x3a/0x60
>  [<f10a60ca>] ? nfs4_set_client+0xea/0x2b0[nfs]
>  [<f10a6d0c>] ? nfs4_create_server+0xac/0x1b0[nfs]
>  [<c04f1400>] ? krealloc+0x40/0x50
>  [<f10b0e8b>] ? nfs4_remote_get_sb+0x6b/0x250[nfs]
>  [<c04f14ec>] ? kstrdup+0x3c/0x60
>  [<c0520739>] ? vfs_kern_mount+0x69/0x170
>  [<f10b1a3c>] ? nfs_do_root_mount+0x6c/0xa0[nfs]
>  [<f10b1b47>] ? nfs4_try_mount+0x37/0xa0[nfs]
>  [<f10afe6d>] ? nfs4_validate_text_mount_data+-x7d/0xf0[nfs]
>  [<f10b1c42>] ? nfs4_get_sb+0x92/0x2f0
>  [<c0520739>] ? vfs_kern_mount+0x69/0x170
>  [<c05366d2>] ? get_fs_type+0x32/0xb0
>  [<c052089f>] ? do_kern_mount+0x3f/0xe0
>  [<c053954f>] ? do_mount+0x2ef/0x740
>  [<c0537740>] ? copy_mount_options+0xb0/0x120
>  [<c0539a0e>] ? sys_mount+0x6e/0xa0

Hi,

Does the following patch fix the problem?

Cheers
  Trond

--------------------------
SUNRPC: Fix a BUG in __rpc_create_common

From: Trond Myklebust <Trond.Myklebust@netapp.com>

Mi Jinlong reports:

When testing NFSv4 at RHEL6 with kernel 2.6.32, I got a kernel panic
at NFS client's __rpc_create_common function.

The panic place is:
  rpc_mkpipe
      __rpc_lookup_create()          <=== find pipefile *idmap*
      __rpc_mkpipe()                 <=== pipefile is *idmap*
        __rpc_create_common()
         ******  BUG_ON(!d_unhashed(dentry)); ****** *panic*

The test is wrong: we can find ourselves with a hashed negative dentry here
if the idmapper tried to look up the file before we got round to creating
it.

Just replace the BUG_ON() with a d_drop(dentry).

Reported-by: Mi Jinlong <mijinlong@cn.fujitsu.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2011-01-04 13:10:38 -05:00
David S. Miller 17f7f4d9fc Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	net/ipv4/fib_frontend.c
2010-12-26 22:37:05 -08:00
Joe Perches b3bcedadf2 net/sunrpc/clnt.c: Convert sprintf_symbol to %ps
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-12-21 11:51:26 -05:00
Joe Perches f3c0ceea83 net/sunrpc/auth_gss/gss_krb5_crypto.c: Use normal negative error value return
And remove unnecessary double semicolon too.

No effect to code, as test is != 0.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2010-12-17 15:48:22 -05:00
Shan Wei 66c941f4aa net: sunrpc: kill unused macros
These macros never be used for several years.

Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2010-12-17 15:48:21 -05:00
NeilBrown 3942302ea9 sunrpc: svc_sock_names should hold ref to socket being closed.
Currently svc_sock_names calls svc_close_xprt on a svc_sock to
which it does not own a reference.
As soon as svc_close_xprt sets XPT_CLOSE, the socket could be
freed by a separate thread (though this is a very unlikely race).

It is safer to hold a reference while calling svc_close_xprt.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2010-12-17 15:48:19 -05:00
NeilBrown 7c96aef759 sunrpc: remove xpt_pool
The xpt_pool field is only used for reporting BUGs.
And it isn't used correctly.

In particular, when it is cleared in svc_xprt_received before
XPT_BUSY is cleared, there is no guarantee that either the
compiler or the CPU might not re-order to two assignments, just
setting xpt_pool to NULL after XPT_BUSY is cleared.

If a different cpu were running svc_xprt_enqueue at this moment,
it might see XPT_BUSY clear and then xpt_pool non-NULL, and
so BUG.

This could be fixed by calling
  smp_mb__before_clear_bit()
before the clear_bit.  However as xpt_pool isn't really used,
it seems safest to simply remove xpt_pool.

Another alternate would be to change the clear_bit to
clear_bit_unlock, and the test_and_set_bit to test_and_set_bit_lock.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2010-12-17 15:48:18 -05:00
J. Bruce Fields ec66ee3797 Merge commit 'v2.6.37-rc6' into for-2.6.38 2010-12-17 13:29:07 -05:00
Chuck Lever bf2695516d SUNRPC: New xdr_streams XDR decoder API
Now that all client-side XDR decoder routines use xdr_streams, there
should be no need to support the legacy calling sequence [rpc_rqst *,
__be32 *, RPC res *] anywhere.  We can construct an xdr_stream in the
generic RPC code, instead of in each decoder function.

This is a refactoring change.  It should not cause different behavior.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-12-16 12:37:25 -05:00
Chuck Lever 9f06c719f4 SUNRPC: New xdr_streams XDR encoder API
Now that all client-side XDR encoder routines use xdr_streams, there
should be no need to support the legacy calling sequence [rpc_rqst *,
__be32 *, RPC arg *] anywhere.  We can construct an xdr_stream in the
generic RPC code, instead of in each encoder function.

Also, all the client-side encoder functions return 0 now, making a
return value superfluous.  Take this opportunity to convert them to
return void instead.

This is a refactoring change.  It should not cause different behavior.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-12-16 12:37:25 -05:00
Chuck Lever 1ac7c23e4a SUNRPC: Determine value of "nrprocs" automatically
Clean up.

Just fixed a panic where the nrprocs field in a different upper layer
client was set by hand incorrectly.  Use the compiler-generated method
used by the other upper layer protocols.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-12-16 12:37:25 -05:00
Chuck Lever 4129ccf303 SUNRPC: Avoid return code checking in rpcbind XDR encoder functions
Clean up.

The trend in the other XDR encoder functions is to BUG() when encoding
problems occur, since a problem here is always due to a local coding
error.  Then, instead of a status, zero is unconditionally returned.

Update the rpcbind XDR encoders to behave this way.

To finish the update, use the new-style be32_to_cpup() and
cpu_to_be32() macros, and compute the buffer sizes using raw integers
instead of sizeof().  This matches the conventions used in other XDR
functions.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Tested-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-12-16 12:37:25 -05:00
Tejun Heo afe2c511fb workqueue: convert cancel_rearming_delayed_work[queue]() users to cancel_delayed_work_sync()
cancel_rearming_delayed_work[queue]() has been superceded by
cancel_delayed_work_sync() quite some time ago.  Convert all the
in-kernel users.  The conversions are completely equivalent and
trivial.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: "David S. Miller" <davem@davemloft.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Cc: Jeff Garzik <jgarzik@pobox.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: netdev@vger.kernel.org
Cc: Anton Vorontsov <cbou@mail.ru>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Alex Elder <aelder@sgi.com>
Cc: xfs-masters@oss.sgi.com
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: netfilter-devel@vger.kernel.org
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: linux-nfs@vger.kernel.org
2010-12-15 10:56:11 +01:00
NeilBrown ed2849d3ec sunrpc: prevent use-after-free on clearing XPT_BUSY
When an xprt is created, it has a refcount of 1, and XPT_BUSY is set.
The refcount is *not* owned by the thread that created the xprt
(as is clear from the fact that creators never put the reference).
Rather, it is owned by the absence of XPT_DEAD.  Once XPT_DEAD is set,
(And XPT_BUSY is clear) that initial reference is dropped and the xprt
can be freed.

So when a creator clears XPT_BUSY it is dropping its only reference and
so must not touch the xprt again.

However svc_recv, after calling ->xpo_accept (and so getting an XPT_BUSY
reference on a new xprt), calls svc_xprt_recieved.  This clears
XPT_BUSY and then svc_xprt_enqueue - this last without owning a reference.
This is dangerous and has been seen to leave svc_xprt_enqueue working
with an xprt containing garbage.

So we need to hold an extra counted reference over that call to
svc_xprt_received.

For safety, any time we clear XPT_BUSY and then use the xprt again, we
first get a reference, and the put it again afterwards.

Note that svc_close_all does not need this extra protection as there are
no threads running, and the final free can only be called asynchronously
from such a thread.

Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2010-12-07 20:39:55 -05:00
Trond Myklebust 5fc43978a7 SUNRPC: Fix an infinite loop in call_refresh/call_refreshresult
If the rpcauth_refreshcred() call returns an error other than
EACCES, ENOMEM or ETIMEDOUT, we currently end up looping forever
between call_refresh and call_refreshresult.

The correct thing to do here is to exit on all errors except
EAGAIN and ETIMEDOUT, for which case we retry 3 times, then
return EACCES.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-11-22 13:22:39 -05:00
Tracey Dent fdb26195f4 Net: sunrpc: auth_gss: Makefile: Remove deprecated kbuild goal definitions
Changed Makefile to use <modules>-y instead of <modules>-objs
because -objs is deprecated and not mentioned in
Documentation/kbuild/makefiles.txt.

Signed-off-by: Tracey Dent <tdent48227@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-22 08:16:16 -08:00
J. Bruce Fields 9c335c0b8d svcrpc: fix wspace-checking race
We call svc_xprt_enqueue() after something happens which we think may
require handling from a server thread.  To avoid such events being lost,
svc_xprt_enqueue() must guarantee that there will be a svc_serv() call
from a server thread following any such event.  It does that by either
waking up a server thread itself, or checking that XPT_BUSY is set (in
which case somebody else is doing it).

But the check of XPT_BUSY could occur just as someone finishes
processing some other event, and just before they clear XPT_BUSY.

Therefore it's important not to clear XPT_BUSY without subsequently
doing another svc_export_enqueue() to check whether the xprt should be
requeued.

The xpo_wspace() check in svc_xprt_enqueue() breaks this rule, allowing
an event to be missed in situations like:

	data arrives
	call svc_tcp_data_ready():
	call svc_xprt_enqueue():
	set BUSY
	find no write space
				svc_reserve():
				free up write space
				call svc_enqueue():
				test BUSY
	clear BUSY

So, instead, check wspace in the same places that the state flags are
checked: before taking BUSY, and in svc_receive().

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2010-11-19 18:35:12 -05:00
J. Bruce Fields b176331627 svcrpc: svc_close_xprt comment
Neil Brown had to explain to me why we do this here; record the answer
for posterity.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2010-11-19 18:35:12 -05:00
J. Bruce Fields f8c0d226fe svcrpc: simplify svc_close_all
There's no need to be fooling with XPT_BUSY now that all the threads
are gone.

The list_del_init() here could execute at the same time as the
svc_xprt_enqueue()'s list_add_tail(), with undefined results.  We don't
really care at this point, but it might result in a spurious
list-corruption warning or something.

And svc_close() isn't adding any value; just call svc_delete_xprt()
directly.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2010-11-19 18:35:11 -05:00
J. Bruce Fields ca7896cd83 nfsd4: centralize more calls to svc_xprt_received
Follow up on b48fa6b991 by moving all the
svc_xprt_received() calls for the main xprt to one place.  The clearing
of XPT_BUSY here is critical to the correctness of the server, so I'd
prefer it to be obvious where we do it.

The only substantive result is moving svc_xprt_received() after
svc_receive_deferred().  Other than a (likely insignificant) delay
waking up the next thread, that should be harmless.

Also reshuffle the exit code a little to skip a few other steps that we
don't care about the in the svc_delete_xprt() case.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2010-11-19 18:35:11 -05:00
J. Bruce Fields 62bac4af3d svcrpc: don't set then immediately clear XPT_DEFERRED
There's no harm to doing this, since the only caller will immediately
call svc_enqueue() afterwards, ensuring we don't miss the remaining
deferred requests just because XPT_DEFERRED was briefly cleared.

But why not just do this the simple way?

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2010-11-19 18:35:11 -05:00
Arnd Bergmann 451a3c24b0 BKL: remove extraneous #include <smp_lock.h>
The big kernel lock has been removed from all these files at some point,
leaving only the #include.

Remove this too as a cleanup.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-17 08:59:32 -08:00
Jesper Juhl 94f58df8e5 SUNRPC: Simplify rpc_alloc_iostats by removing pointless local variable
Hi,

We can simplify net/sunrpc/stats.c::rpc_alloc_iostats() a bit by getting
rid of the unneeded local variable 'new'.

Please CC me on replies.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-11-16 11:58:51 -05:00
Al Viro fc14f2fef6 convert get_sb_single() users
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-29 04:16:28 -04:00
Linus Torvalds 426e1f5cec Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (52 commits)
  split invalidate_inodes()
  fs: skip I_FREEING inodes in writeback_sb_inodes
  fs: fold invalidate_list into invalidate_inodes
  fs: do not drop inode_lock in dispose_list
  fs: inode split IO and LRU lists
  fs: switch bdev inode bdi's correctly
  fs: fix buffer invalidation in invalidate_list
  fsnotify: use dget_parent
  smbfs: use dget_parent
  exportfs: use dget_parent
  fs: use RCU read side protection in d_validate
  fs: clean up dentry lru modification
  fs: split __shrink_dcache_sb
  fs: improve DCACHE_REFERENCED usage
  fs: use percpu counter for nr_dentry and nr_dentry_unused
  fs: simplify __d_free
  fs: take dcache_lock inside __d_path
  fs: do not assign default i_ino in new_inode
  fs: introduce a per-cpu last_ino allocator
  new helper: ihold()
  ...
2010-10-26 17:58:44 -07:00
Linus Torvalds 4390110fef Merge branch 'for-2.6.37' of git://linux-nfs.org/~bfields/linux
* 'for-2.6.37' of git://linux-nfs.org/~bfields/linux: (99 commits)
  svcrpc: svc_tcp_sendto XPT_DEAD check is redundant
  svcrpc: no need for XPT_DEAD check in svc_xprt_enqueue
  svcrpc: assume svc_delete_xprt() called only once
  svcrpc: never clear XPT_BUSY on dead xprt
  nfsd4: fix connection allocation in sequence()
  nfsd4: only require krb5 principal for NFSv4.0 callbacks
  nfsd4: move minorversion to client
  nfsd4: delay session removal till free_client
  nfsd4: separate callback change and callback probe
  nfsd4: callback program number is per-session
  nfsd4: track backchannel connections
  nfsd4: confirm only on succesful create_session
  nfsd4: make backchannel sequence number per-session
  nfsd4: use client pointer to backchannel session
  nfsd4: move callback setup into session init code
  nfsd4: don't cache seq_misordered replies
  SUNRPC: Properly initialize sock_xprt.srcaddr in all cases
  SUNRPC: Use conventional switch statement when reclassifying sockets
  sunrpc/xprtrdma: clean up workqueue usage
  sunrpc: Turn list_for_each-s into the ..._entry-s
  ...

Fix up trivial conflicts (two different deprecation notices added in
separate branches) in Documentation/feature-removal-schedule.txt
2010-10-26 09:55:25 -07:00