Commit Graph

185 Commits

Author SHA1 Message Date
Trond Myklebust 78ea323be6 NFSv4: Don't use cred->cr_ops->cr_name in nfs4_proc_setclientid()
With the recent change to generic creds, we can no longer use
cred->cr_ops->cr_name to distinguish between RPCSEC_GSS principals and
AUTH_SYS/AUTH_NULL identities. Replace it with the rpc_authops->au_name
instead...

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-04-19 16:54:53 -04:00
Trond Myklebust 536ff0f809 NFSv4: Ensure we don't corrupt fl->fl_flags in nfs4_proc_unlck
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-04-19 16:53:33 -04:00
Trond Myklebust c1d519312d NFSv4: Only increment the sequence id if the server saw it
It is quite possible that the OPEN, CLOSE, LOCK, LOCKU,... compounds fail
before the actual stateful operation has been executed (for instance in the
PUTFH call). There is no way to tell from the overall status result which
operations were executed from the COMPOUND.

The fix is to move incrementing of the sequence id into the XDR layer,
so that we do it as we process the results from the stateful operation.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-04-19 16:53:15 -04:00
Trond Myklebust 35d05778e2 NFSv4: Remove bogus call to nfs4_drop_state_owner() in _nfs4_open_expired()
There should be no need to invalidate a perfectly good state owner just
because of a stale filehandle. Doing so can cause the state recovery code
to break, since nfs4_get_renew_cred() and nfs4_get_setclientid_cred() rely
on finding active state owners.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-04-19 16:53:12 -04:00
Trond Myklebust 98a8e32394 SUNRPC: Add a helper rpcauth_lookup_generic_cred()
The NFSv4 protocol allows clients to negotiate security protocols on the
fly in the case where an administrator on the server changes the export
settings and/or in the case where we may have a filesystem migration event.

Instead of having the NFS client code cache credentials that are tied to a
particular AUTH method it is therefore preferable to have a generic credential
that can be converted into whatever AUTH is in use by the RPC client when
the read/write/sillyrename/... is put on the wire.

We do this by means of the new "generic" credential, which basically just
caches the minimal information that is needed to look up an RPCSEC_GSS,
AUTH_SYS, or AUTH_NULL credential.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-03-14 13:42:49 -04:00
Trond Myklebust 5d00837b90 SUNRPC: Run rpc timeout functions as callbacks instead of in softirqs
An audit of the current RPC timeout functions shows that they don't really
ever need to run in the softirq context. As long as the softirq is
able to signal that the wakeup is due to a timeout (which it can do by
setting task->tk_status to -ETIMEDOUT) then the callback functions can just
run as standard task->tk_callback functions (in the rpciod/process
context).

The only possible border-line case would be xprt_timer() for the case of
UDP, when the callback is used to reduce the size of the transport
congestion window. In testing, however, the effect of moving that update
to a callback would appear to be minor.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-02-25 21:40:44 -08:00
Trond Myklebust fda1393938 SUNRPC: Convert users of rpc_wake_up_task to use rpc_wake_up_queued_task
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-02-25 21:40:42 -08:00
Trond Myklebust 101070ca2f NFS: Ensure that the asynchronous RPC calls complete on nfsiod.
We want to ensure that rpc_call_ops that involve mntput() are run on nfsiod
rather than on rpciod, so that they don't deadlock when the resulting
umount calls rpc_shutdown_client(). Hence we specify that read, write and
commit calls must complete on nfsiod.
Ditto for NFSv4 open, lock, locku and close asynchronous calls.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-02-25 21:40:37 -08:00
Jan Blunck 4ac9137858 Embed a struct path into struct nameidata instead of nd->{dentry,mnt}
This is the central patch of a cleanup series. In most cases there is no good
reason why someone would want to use a dentry for itself. This series reflects
that fact and embeds a struct path into nameidata.

Together with the other patches of this series
- it enforced the correct order of getting/releasing the reference count on
  <dentry,vfsmount> pairs
- it prepares the VFS for stacking support since it is essential to have a
  struct path in every place where the stack can be traversed
- it reduces the overall code size:

without patch series:
   text    data     bss     dec     hex filename
5321639  858418  715768 6895825  6938d1 vmlinux

with patch series:
   text    data     bss     dec     hex filename
5320026  858418  715768 6894212  693284 vmlinux

This patch:

Switch from nd->{dentry,mnt} to nd->path.{dentry,mnt} everywhere.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix cifs]
[akpm@linux-foundation.org: fix smack]
Signed-off-by: Jan Blunck <jblunck@suse.de>
Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-14 21:13:33 -08:00
Linus Torvalds 75659ca0c1 Merge branch 'task_killable' of git://git.kernel.org/pub/scm/linux/kernel/git/willy/misc
* 'task_killable' of git://git.kernel.org/pub/scm/linux/kernel/git/willy/misc: (22 commits)
  Remove commented-out code copied from NFS
  NFS: Switch from intr mount option to TASK_KILLABLE
  Add wait_for_completion_killable
  Add wait_event_killable
  Add schedule_timeout_killable
  Use mutex_lock_killable in vfs_readdir
  Add mutex_lock_killable
  Use lock_page_killable
  Add lock_page_killable
  Add fatal_signal_pending
  Add TASK_WAKEKILL
  exit: Use task_is_*
  signal: Use task_is_*
  sched: Use task_contributes_to_load, TASK_ALL and TASK_NORMAL
  ptrace: Use task_is_*
  power: Use task_is_*
  wait: Use TASK_NORMAL
  proc/base.c: Use task_is_*
  proc/array.c: Use TASK_REPORT
  perfmon: Use task_is_*
  ...

Fixed up conflicts in NFS/sunrpc manually..
2008-02-01 11:45:47 +11:00
Trond Myklebust e6f8107595 NFS: Add an asynchronous delegreturn operation for use in nfs_clear_inode
Otherwise, there is a potential deadlock if the last dput() from an NFSv4
close() or other asynchronous operation leads to nfs_clear_inode calling
the synchronous delegreturn.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-01-30 02:06:12 -05:00
J. Bruce Fields 3d1c550874 nfs4: allow nfsv4 acls on non-regular-files
The rfc doesn't give any reason it shouldn't be possible to set an
attribute on a non-regular file.  And if the server supports it, then it
shouldn't be up to us to prevent it.

Thanks to Erez for the report and Trond for further analysis.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Tested-by: Erez Zadok <ezk@cs.sunysb.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-01-30 02:06:10 -05:00
Trond Myklebust 69dd716c5f NFSv4: Add socket proto argument to setclientid
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-01-30 02:05:58 -05:00
Chuck Lever d4d3c50749 NFS: Enable NFS client to generate CLIENTID strings with IPv6 addresses
We recently added methods to RPC transports that provide string versions of
the remote peer address information.  Convert the NFSv4 SETCLIENTID
procedure to use those methods instead of building the client ID out of
whole cloth.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-01-30 02:05:51 -05:00
Trond Myklebust bfc69a4566 NFS: define a function to update nfsi->cache_change_attribute
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-01-30 02:05:47 -05:00
Trond Myklebust 5138fde011 NFS/SUNRPC: Convert all users of rpc_call_setup()
Replace use of rpc_call_setup() with rpc_init_task(), and in cases where we
need to initialise task->tk_action, with rpc_call_start().

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-01-30 02:05:32 -05:00
Trond Myklebust bdc7f021f3 NFS: Clean up the (commit|read|write)_setup() callback routines
Move the common code for setting up the nfs_write_data and nfs_read_data
structures into fs/nfs/read.c, fs/nfs/write.c and fs/nfs/direct.c.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-01-30 02:05:32 -05:00
Trond Myklebust c970aa85e7 SUNRPC: Clean up rpc_run_task
Make it use the new task initialiser structure instead of acting as a
wrapper.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-01-30 02:05:30 -05:00
Trond Myklebust 2f74c0a056 NFSv4: Clean up the OPEN/CLOSE serialisation code
Reduce the time spent locking the rpc_sequence structure by queuing the
nfs_seqid only when we are ready to take the lock (when calling
nfs_wait_on_sequence).

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-01-30 02:05:24 -05:00
Trond Myklebust e6e21970ba NFSv4: Fix open_to_lock_owner sequenceid allocation...
NFSv4 file locking is currently completely broken since it doesn't respect
the OPEN sequencing when it is given an unconfirmed lock_owner and needs to
do an open_to_lock_owner. Worse: it breaks the sunrpc rules by doing a
GFP_KERNEL allocation inside an rpciod callback.

Fix is to preallocate the open seqid structure in nfs4_alloc_lockdata if we
see that the lock_owner is unconfirmed.
Then, in nfs4_lock_prepare() we wait for either the open_seqid, if
the lock_owner is still unconfirmed, or else fall back to waiting on the
standard lock_seqid.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-01-03 09:37:17 -05:00
Trond Myklebust bb22629ee8 NFSv4: nfs4_open_confirm must not set the open_owner as confirmed on error
RFC3530 states that the open_owner is confirmed if and only if the client
sends an OPEN_CONFIRM request with the appropriate sequence id and stateid
within the lease period.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-01-03 09:37:17 -05:00
Matthew Wilcox 150030b78a NFS: Switch from intr mount option to TASK_KILLABLE
By using the TASK_KILLABLE infrastructure, we can get rid of the 'intr'
mount option.  We have to use _killable everywhere instead of _interruptible
as we get rid of rpc_clnt_sigmask/sigunmask.

Signed-off-by: Liam R. Howlett <howlett@gmail.com>
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
2007-12-06 17:40:25 -05:00
Trond Myklebust a49c3c7736 NFSv4: Ensure that we wait for the CLOSE request to complete
Otherwise, we do end up breaking close-to-open semantics. We also end up
breaking some of the silly-rename tests in Connectathon on some setups.

Please refer to the bug-report at
	http://bugzilla.linux-nfs.org/show_bug.cgi?id=150

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-10-19 17:19:25 -04:00
Trond Myklebust 565277f63c NFS: Fix a race in sillyrename
lookup() and sillyrename() can race one another because the sillyrename()
completion cannot take the parent directory's inode->i_mutex since the
latter may be held by whoever is calling dput().

We therefore have little option but to add extra locking to ensure that
nfs_lookup() and nfs_atomic_open() do not race with the sillyrename
completion.
If somebody has looked up the sillyrenamed file in the meantime, we just
transfer the sillydelete information to the new dentry.

Please refer to the bug-report at
	http://bugzilla.linux-nfs.org/show_bug.cgi?id=150

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-10-19 17:19:16 -04:00
Trond Myklebust 40d2470409 NFS: Fix a connectathon regression in NFSv3 and NFSv4
We're failing basic test6 against Linux servers because they lack a correct
change attribute. The fix is to assume that we always want to invalidate
the readdir caches when we call update_changeattr and/or
nfs_post_op_update_inode on a directory.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-10-09 17:20:47 -04:00
Trond Myklebust 9e08a3c5ae NFS: Use nfs_refresh_inode() in ops that aren't expected to change the inode
nfs_post_op_update_inode() is really only meant to be used if we expect the
inode and its attributes to have changed in some way.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-10-09 17:20:45 -04:00
Trond Myklebust d75340cc4d NFSv4: Fix nfs_atomic_open() to set the verifier on negative dentries too
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-10-09 17:20:06 -04:00
Trond Myklebust d4d9cdcb47 NFS: Don't hash the negative dentry when optimising for an O_EXCL open
We don't want to leave an unverified hashed negative dentry if the
exclusive create fails to complete.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-10-09 17:19:27 -04:00
Trond Myklebust 70ca88521f NFS: Fake up 'wcc' attributes to prevent cache invalidation after write
NFSv2 and v4 don't offer weak cache consistency attributes on WRITE calls.
In NFSv3, returning wcc data is optional. In all cases, we want to prevent
the client from invalidating our cached data whenever ->write_done()
attempts to update the inode attributes.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-10-09 17:19:15 -04:00
Trond Myklebust 8850df999c NFS: Fix atime revalidation in read()
NFSv3 will correctly update atime on a read() call, so there is no need to
set the NFS_INO_INVALID_ATIME flag unless the call to nfs_refresh_inode()
fails.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-10-09 17:19:06 -04:00
Trond Myklebust c481299839 NFS: Fix atime revalidation in readdir()
NFSv3 will correctly update atime on a readdir call, so there is no need to
set the NFS_INO_INVALID_ATIME flag unless the call to nfs_refresh_inode()
fails.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-10-09 17:19:03 -04:00
Trond Myklebust 17cadc9537 NFS: Don't force a dcache revalidation if nfs_wcc_update_inode succeeds
The reason is that if the weak cache consistency update was successful,
then we know that our client must be the only one that changed the
directory, and we've already updated the dcache to reflect the change.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-10-09 17:18:55 -04:00
Trond Myklebust 76b32999df NFSv4: Make NFSv4 ACCESS calls return attributes too...
It doesn't really make sense to cache an access call without also
revalidating the attributes.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-10-09 17:18:38 -04:00
Trond Myklebust af22f94ae0 NFSv4: Simplify _nfs4_do_access()
Currently, _nfs4_do_access() is just a copy of nfs_do_access() with added
conversion of the open flags into an access mask. This patch merges the
duplicate functionality.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-10-09 17:18:34 -04:00
Trond Myklebust cd3758e37d NFS: Replace file->private_data with calls to nfs_file_open_context()
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-10-09 17:18:31 -04:00
Peter Staubach 4e769b934e 64 bit ino support for NFS client
Hi.

Attached is a patch to modify the NFS client code to support
64 bit ino's, as appropriate for the system and the NFS
protocol version.

The code basically just expand the NFS interfaces for routines
which handle ino's from using ino_t to u64 and then uses the
fileid in the nfs_inode instead of i_ino in the inode.  The
code paths that were updated are in the getattr method and
the readdir methods.

This should be no real change on 64 bit platforms.  Since
the ino_t is an unsigned long, it would already be 64 bits
wide.

    Thanx...

           ps

Signed-off-by: Peter Staubach <staubach@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-10-09 17:15:29 -04:00
Trond Myklebust deee9369b9 NFSv4: Ensure that we pass the correct dentry to nfs4_intent_set_file
This patch fixes an Oops that was reported by Gabriel Barazer.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-09-01 10:14:38 -04:00
Trond Myklebust 65bbf6bdbb NFSv4: Fix a typo in _nfs4_do_open_reclaim
This should fix the following Oops reported by Jeff Garzik:

kernel BUG at fs/nfs/nfs4xdr.c:1040!
invalid opcode: 0000 [1] SMP 
CPU 0 
Modules linked in: nfs lockd sunrpc af_packet
ipv6 cpufreq_ondemand acpi_cpufreq battery floppy nvram sg snd_hda_intel
ata_generic snd_pcm_oss snd_mixer_oss snd_pcm i2c_i801 snd_page_alloc e1000
firewire_ohci ata_piix i2c_core sr_mod cdrom sata_sil ahci libata sd_mod
scsi_mod ext3 jbd ehci_hcd uhci_hcd
Pid: 16353, comm: 10.10.10.1-recl Not tainted 2.6.23-rc3 #1
RIP: 0010:[<ffffffff88240980>] [<ffffffff88240980>] :nfs:encode_open+0x1c0/0x330
RSP: 0018:ffff8100467c5c60  EFLAGS: 00010202
RAX: ffff81000f89b8b8 RBX: 00000000697a6f6d RCX: ffff81000f89b8b8
RDX: 0000000000000004 RSI: 0000000000000004 RDI: ffff8100467c5c80
RBP: ffff8100467c5c80 R08: ffff81000f89bc30 R09: ffff81000f89b83f
R10: 0000000000000001 R11: ffffffff881e79e0 R12: ffff81003cbd1808
R13: ffff81000f89b860 R14: ffff81005fc984e0 R15: ffffffff88240af0
FS:  0000000000000000(0000) GS:ffffffff8052a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
CR2: 00002adb9e51a030 CR3: 000000007ea7e000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process 10.10.10.1-recl (pid: 16353, threadinfo ffff8100467c4000, task ffff8100038ce780)
Stack:  ffff81004aeb6a40 ffff81003cbd1808 ffff81003cbd1808 ffffffff88240b5d
 ffff81000f89b8bc ffff81005fc984e8 ffff81000f89bc30 ffff81005fc984e8
 0000000300000000 0000000000000000 0000000000000000 ffff81003cbd1800
Call Trace:
 [<ffffffff88240b5d>] :nfs:nfs4_xdr_enc_open_noattr+0x6d/0x90
 [<ffffffff881e74b7>] :sunrpc:rpcauth_wrap_req+0x97/0xf0
 [<ffffffff88240af0>] :nfs:nfs4_xdr_enc_open_noattr+0x0/0x90
 [<ffffffff881df57a>] :sunrpc:call_transmit+0x18a/0x290
 [<ffffffff881e5e7b>] :sunrpc:__rpc_execute+0x6b/0x290
 [<ffffffff881dff76>] :sunrpc:rpc_do_run_task+0x76/0xd0
 [<ffffffff882373f6>] :nfs:_nfs4_proc_open+0x76/0x230
 [<ffffffff88237a2e>] :nfs:nfs4_open_recover_helper+0x5e/0xc0
 [<ffffffff88237b74>] :nfs:nfs4_open_recover+0xe4/0x120
 [<ffffffff88238e14>] :nfs:nfs4_open_reclaim+0xa4/0xf0
 [<ffffffff882413c5>] :nfs:nfs4_reclaim_open_state+0x55/0x1b0
 [<ffffffff882417ea>] :nfs:reclaimer+0x2ca/0x390
 [<ffffffff88241520>] :nfs:reclaimer+0x0/0x390
 [<ffffffff8024e59b>] kthread+0x4b/0x80
 [<ffffffff8020cad8>] child_rip+0xa/0x12
 [<ffffffff8024e550>] kthread+0x0/0x80
 [<ffffffff8020cace>] child_rip+0x0/0x12


Code: 0f 0b eb fe 48 89 ef c7 00 00 00 00 02 be 08 00 00 00 e8 79 
RIP  [<ffffffff88240980>] :nfs:encode_open+0x1c0/0x330
 RSP <ffff8100467c5c60>

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-09-01 10:14:37 -04:00
Trond Myklebust 45328c354e NFS: Fix NFSv4 open stateid regressions
Do not allow cached open for O_RDONLY or O_WRONLY unless the file has been
previously opened in these modes.

Also Fix the calculation of the mode in nfs4_close_prepare. We should only
issue an OPEN_DOWNGRADE if we're sure that we will still be holding the
correct open modes. This may not be the case if we've been doing delegated
opens.

Finally, there is no need to adjust the open mode bit flags in
nfs4_close_done(): that has already been done in nfs4_close_prepare().

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-08-07 15:13:19 -04:00
Trond Myklebust e4eff1a622 SUNRPC: Clean up the sillyrename code
Fix a couple of bugs:
 - Don't rely on the parent dentry still being valid when the call completes.
   Fixes a race with shrink_dcache_for_umount_subtree()

 - Don't remove the file if the filehandle has been labelled as stale.

Fix a couple of inefficiencies
 - Remove the global list of sillyrenamed files. Instead we can cache the
   sillyrename information in the dentry->d_fsdata
 - Move common code from unlink_setup/unlink_done into fs/nfs/unlink.c

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-07-19 15:21:39 -04:00
Trond Myklebust 4fdc17b2a7 NFS: Introduce struct nfs_removeargs+nfs_removeres
We need a common structure for setting up an unlink() rpc call in order to
fix the asynchronous unlink code.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-07-19 15:21:39 -04:00
Trond Myklebust 9936781d01 NFSv4: Try to recover from getfh failures in nfs4_xdr_dec_open
Try harder to recover the open state if the server failed to return a
filehandle.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-07-19 15:09:03 -04:00
Trond Myklebust 56659e9926 NFSv4: 'constify' lookup arguments.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-07-19 15:09:03 -04:00
Trond Myklebust 6f220ed5a8 NFSv4: Fix open state recovery
Ensure that opendata->state is always initialised when we do state
recovery.

Ensure that we set the filehandle in the case where we're doing an
"OPEN_CLAIM_PREVIOUS" call due to a server reboot.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-07-19 15:09:03 -04:00
Frank Filz 137d6acaa6 NFSv4: Make sure unlock is really an unlock when cancelling a lock
I ran into a curious issue when a lock is being canceled. The
cancellation results in a lock request to the vfs layer instead of an
unlock request. This is particularly insidious when the process that
owns the lock is exiting. In that case, sometimes the erroneous lock is
applied AFTER the process has entered zombie state, preventing the lock
from ever being released. Eventually other processes block on the lock
causing a slow degredation of the system. In the 2.6.16 kernel this was
investigated on, the problem is compounded by the fact that the cl_sem
is held while blocking on the vfs lock, which results in most processes
accessing the nfs file system in question hanging.

In more detail, here is how the situation occurs:

first _nfs4_do_setlk():

static int _nfs4_do_setlk(struct nfs4_state *state, int cmd, struct file_lock *fl, int reclaim)
...
        ret = nfs4_wait_for_completion_rpc_task(task);
        if (ret == 0) {
...
        } else
                data->cancelled = 1;

then nfs4_lock_release():

static void nfs4_lock_release(void *calldata)
...
        if (data->cancelled != 0) {
                struct rpc_task *task;
                task = nfs4_do_unlck(&data->fl, data->ctx, data->lsp,
                                data->arg.lock_seqid);

The problem is the same file_lock that was passed in to _nfs4_do_setlk()
gets passed to nfs4_do_unlck() from nfs4_lock_release(). So the type is
still F_RDLCK or FWRLCK, not F_UNLCK. At some point, when cancelling the
lock, the type needs to be changed to F_UNLCK. It seemed easiest to do
that in nfs4_do_unlck(), but it could be done in nfs4_lock_release().
The concern I had with doing it there was if something still needed the
original file_lock, though it turns out the original file_lock still
needs to be modified by nfs4_do_unlck() because nfs4_do_unlck() uses the
original file_lock to pass to the vfs layer, and a copy of the original
file_lock for the RPC request.

It seems like the simplest solution is to force all situations where
nfs4_do_unlck() is being used to result in an unlock, so with that in
mind, I made the following change:

Signed-off-by: Frank Filz <ffilzlnx@us.ibm.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-07-10 23:40:49 -04:00
Trond Myklebust 8bda4e4c98 NFSv4: Fix up stateid locking...
We really don't need to grab both the state->so_owner and the
inode->i_lock.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-07-10 23:40:43 -04:00
Trond Myklebust 1ac7e2fd35 NFSv4: Clean up the callers of nfs4_open_recover_helper()
Rely on nfs4_try_open_cached() when appropriate.

Also fix an RCU violation in _nfs4_do_open_reclaim()

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-07-10 23:40:43 -04:00
Trond Myklebust 6ee4126890 NFSv4: Don't call OPEN if we already have an open stateid for a file
If we already have a stateid with the correct open mode for a given file,
then we can reuse that stateid instead of re-issuing an OPEN call without
violating the close-to-open caching semantics.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-07-10 23:40:43 -04:00
Trond Myklebust aac00a8d0a NFSv4: Check for the existence of a delegation in nfs4_open_prepare()
We should not be calling open() on an inode that has a delegation unless
we're doing a reclaim.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-07-10 23:40:43 -04:00
Trond Myklebust 3e309914a1 NFSv4: Clean up _nfs4_proc_open()
Use a flag instead of the 'data->rpc_status = -ENOMEM hack.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-07-10 23:40:42 -04:00