Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

All we really want is the ability to retrieve the root file handle. We no
longer need the ability to walk down the path, since that is now done in
nfs_follow_remote_path().
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

NFS Filehandles and struct fattr are really too large to be allocated on
the stack. This patch adds in a couple of helper functions to allocate them
dynamically instead.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Fix a number of RCU issues in the NFSv4 delegation code.

 (1) delegation->cred doesn't need to be RCU protected as it's essentially an
     invariant refcounted structure.

     By the time we get to nfs_free_delegation(), the delegation is being
     released, so no one else should be attempting to use the saved
     credentials, and they can be cleared.

     However, since the list of delegations could still be under traversal at
     this point by such as nfs_client_return_marked_delegations(), the cred
     should be released in nfs_do_free_delegation() rather than in
     nfs_free_delegation().  Simply using rcu_assign_pointer() to clear it is
     insufficient as that doesn't stop the cred from being destroyed, and nor
     does calling put_rpccred() after call_rcu(), given that the latter is
     asynchronous.

 (2) nfs_detach_delegation_locked() and nfs_inode_set_delegation() should use
     rcu_derefence_protected() because they can only be called if
     nfs_client::cl_lock is held, and that guards against anyone changing
     nfsi->delegation under it.  Furthermore, the barrier imposed by
     rcu_dereference() is superfluous, given that the spin_lock() is also a
     barrier.

 (3) nfs_detach_delegation_locked() is now passed a pointer to the nfs_client
     struct so that it can issue lockdep advice based on clp->cl_lock for (2).

 (4) nfs_inode_return_delegation_noreclaim() and nfs_inode_return_delegation()
     should use rcu_access_pointer() outside the spinlocked region as they
     merely examine the pointer and don't follow it, thus rendering unnecessary
     the need to impose a partial ordering over the one item of interest.

     These result in an RCU warning like the following:

[ INFO: suspicious rcu_dereference_check() usage. ]
---------------------------------------------------
fs/nfs/delegation.c:332 invoked rcu_dereference_check() without protection!

other info that might help us debug this:

rcu_scheduler_active = 1, debug_locks = 0
2 locks held by mount.nfs4/2281:
 #0:  (&type->s_umount_key#34){+.+...}, at: [<ffffffff810b25b4>] deactivate_super+0x60/0x80
 #1:  (iprune_sem){+.+...}, at: [<ffffffff810c332a>] invalidate_inodes+0x39/0x13a

stack backtrace:
Pid: 2281, comm: mount.nfs4 Not tainted 2.6.34-rc1-cachefs #110
Call Trace:
 [<ffffffff8105149f>] lockdep_rcu_dereference+0xaa/0xb2
 [<ffffffffa00b4591>] nfs_inode_return_delegation_noreclaim+0x5b/0xa0 [nfs]
 [<ffffffffa0095d63>] nfs4_clear_inode+0x11/0x1e [nfs]
 [<ffffffff810c2d92>] clear_inode+0x9e/0xf8
 [<ffffffff810c3028>] dispose_list+0x67/0x10e
 [<ffffffff810c340d>] invalidate_inodes+0x11c/0x13a
 [<ffffffff810b1dc1>] generic_shutdown_super+0x42/0xf4
 [<ffffffff810b1ebe>] kill_anon_super+0x11/0x4f
 [<ffffffffa009893c>] nfs4_kill_super+0x3f/0x72 [nfs]
 [<ffffffff810b25bc>] deactivate_super+0x68/0x80
 [<ffffffff810c6744>] mntput_no_expire+0xbb/0xf8
 [<ffffffff810c681b>] release_mounts+0x9a/0xb0
 [<ffffffff810c689b>] put_mnt_ns+0x6a/0x79
 [<ffffffffa00983a1>] nfs_follow_remote_path+0x5a/0x146 [nfs]
 [<ffffffffa0098334>] ? nfs_do_root_mount+0x82/0x95 [nfs]
 [<ffffffffa00985a9>] nfs4_try_mount+0x75/0xaf [nfs]
 [<ffffffffa0098874>] nfs4_get_sb+0x291/0x31a [nfs]
 [<ffffffff810b2059>] vfs_kern_mount+0xb8/0x177
 [<ffffffff810b2176>] do_kern_mount+0x48/0xe8
 [<ffffffff810c810b>] do_mount+0x782/0x7f9
 [<ffffffff810c8205>] sys_mount+0x83/0xbe
 [<ffffffff81001eeb>] system_call_fastpath+0x16/0x1b

Also on:

fs/nfs/delegation.c:215 invoked rcu_dereference_check() without protection!
 [<ffffffff8105149f>] lockdep_rcu_dereference+0xaa/0xb2
 [<ffffffffa00b4223>] nfs_inode_set_delegation+0xfe/0x219 [nfs]
 [<ffffffffa00a9c6f>] nfs4_opendata_to_nfs4_state+0x2c2/0x30d [nfs]
 [<ffffffffa00aa15d>] nfs4_do_open+0x2a6/0x3a6 [nfs]
 ...

And:

fs/nfs/delegation.c:40 invoked rcu_dereference_check() without protection!
 [<ffffffff8105149f>] lockdep_rcu_dereference+0xaa/0xb2
 [<ffffffffa00b3bef>] nfs_free_delegation+0x3d/0x6e [nfs]
 [<ffffffffa00b3e71>] nfs_do_return_delegation+0x26/0x30 [nfs]
 [<ffffffffa00b406a>] __nfs_inode_return_delegation+0x1ef/0x1fe [nfs]
 [<ffffffffa00b448a>] nfs_client_return_marked_delegations+0xc9/0x124 [nfs]
 ...
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Ensure that we correctly rcu-dereference the delegation itself, and that we
protect against removal while we're changing the contents.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>

If dentry found stale happens to be a root of disconnected tree, we
can't d_drop() it; its d_hash is actually part of s_anon and d_drop()
would simply hide it from shrink_dcache_for_umount(), leading to
all sorts of fun, including busy inodes on umount and oopsen after
that.

Bug had been there since at least 2006 (commit c636eb already has it),
so it's definitely -stable fodder.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Cc: stable@kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

With CONFIG_NFS_V4 and data version 4, nfs_get_sb will allocate memory for
export_path in nfs4_validate_text_mount_data, so we need to free it then.
This is addressed in following kmemleak report:

unreferenced object 0xffff88016bf48a50 (size 16):
  comm "mount.nfs", pid 22567, jiffies 4651574704 (age 175471.200s)
  hex dump (first 16 bytes):
    2f 6f 70 74 2f 77 6f 72 6b 00 6b 6b 6b 6b 6b a5  /opt/work.kkkkk.
  backtrace:
    [<ffffffff814b34f9>] kmemleak_alloc+0x60/0xa7
    [<ffffffff81102c76>] kmemleak_alloc_recursive.clone.5+0x1b/0x1d
    [<ffffffff811046b3>] __kmalloc_track_caller+0x18f/0x1b7
    [<ffffffff810e1b08>] kstrndup+0x37/0x54
    [<ffffffffa0336971>] nfs_parse_devname+0x152/0x204 [nfs]
    [<ffffffffa0336af3>] nfs4_validate_text_mount_data+0xd0/0xdc [nfs]
    [<ffffffffa0338deb>] nfs_get_sb+0x325/0x736 [nfs]
    [<ffffffff81113671>] vfs_kern_mount+0xbd/0x17c
    [<ffffffff81113798>] do_kern_mount+0x4d/0xed
    [<ffffffff81129a87>] do_mount+0x787/0x7fe
    [<ffffffff81129b86>] sys_mount+0x88/0xc2
    [<ffffffff81009b42>] system_call_fastpath+0x16/0x1b
Signed-off-by: NXiaotian Feng <dfeng@redhat.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Benny Halevy <bhalevy@panasas.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Andy Adamson <andros@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The original code passed an ERR_PTR() to rpc_put_task() and instead of
returning zero on success it returned -ENOMEM.
Signed-off-by: NDan Carpenter <error27@gmail.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Neil Brown reports that he is seeing the BUG_ON(ret == 0) trigger in
nfs_page_async_flush. According to the trace in
     https://bugzilla.novell.com/show_bug.cgi?id=599628
the problem appears to be due to nfs_wb_page() not waiting for the
PG_writeback flag to clear.

There is a ditto problem in nfs_wb_page_cancel()
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Commit 2c61be0a (NFS: Ensure that the WRITE
and COMMIT RPC calls are always uninterruptible) exposed a race on file
close. In order to ensure correct close-to-open behaviour, we want to wait
for all outstanding background commit operations to complete.

This patch adds an inode flag that indicates if a commit operation is under
way, and provides a mechanism to allow ->write_inode() to wait for its
completion if this is a data integrity flush.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

nfs_path() returns an ERR_PTR(), it doesn't return null.
Signed-off-by: NDan Carpenter <error27@gmail.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

NFSv4 mounts ignore the rsize and wsize mount options, and always use
the default transfer size for both.  This seems to be because all
NFSv4 mounts are now cloned, and the cloning logic doesn't copy the
rsize and wsize settings from the parent nfs_server.

I tested Fedora's 2.6.32.11-99 and it seems to have this problem as
well, so I'm guessing that .33, .32, and perhaps older kernels have
this issue as well.
Signed-off-by: NChuck Lever <chuck.lever@oracle.com>
Cc: Stable <stable@kernel.org>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Fix https://bugzilla.kernel.org/show_bug.cgi?id=15789Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Arnaud Giersch reports that NFSv4 locking is broken when we hold a
delegation since commit 8e469ebd (NFSv4:
Don't allow posix locking against servers that don't support it).

According to Arnaud, the lock succeeds the first time he opens the file
(since we cannot do a delegated open) but then fails after we start using
delegated opens.

The following patch fixes it by ensuring that locking behaviour is
governed by a per-filesystem capability flag that is initially set, but
gets cleared if the server ever returns an OPEN without the
NFS4_OPEN_RESULT_LOCKTYPE_POSIX flag being set.
Reported-by: NArnaud Giersch <arnaud.giersch@iut-bm.univ-fcomte.fr>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org

We always want to ensure that WRITE and COMMIT completes, whether or not
the user presses ^C. Do this by making the call asynchronous, and allowing
the user to do an interruptible wait for rpc_task completion.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This patch fixes a race which occurs due to the fact that we release the
PG_writeback flag while still holding the nfs_page locked.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Since writeback_single_inode() checks the inode->i_state flags _before_ it
flushes out the data, we need to ensure that the I_DIRTY_DATASYNC flag is
already set. Otherwise we risk not seeing a call to write_inode(), which
again means that we break fsync() et al...
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org

	If nfs atomic open implementation ends up doing open request from
->d_revalidate() codepath and gets an error from server, return that error
to caller explicitly and don't bother with lookup_instantiate_filp() at all.
->d_revalidate() can return an error itself just fine...

See
	http://bugzilla.kernel.org/show_bug.cgi?id=15674
	http://marc.info/?l=linux-kernel&m=126988782722711&w=2

for original report.
Reported-by: NDaniel J Blueman <daniel.blueman@gmail.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: NTejun Heo <tj@kernel.org>
Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

The reply parsing code attempts to decode the GETATTR response even if
the DELEGRETURN portion of the compound returned an error. The GETATTR
response won't actually exist if that's the case and we're asking the
parser to read past the end of the response.

This bug is fairly benign. The parser catches this without reading past
the end of the response and decode_getfattr returns -EIO. Earlier
kernels however had decode_op_hdr using the READ_BUF macro, and this
bug would make this printk pop any time the client got an error from
a delegreturn:

kernel: decode_op_hdr: reply buffer overflowed in line XXXX

More recent kernels seem to have replaced this printk with a dprintk.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We should not attempt to free the page if __GFP_FS is not set. Otherwise we
can deadlock as per

  http://bugzilla.kernel.org/show_bug.cgi?id=15578Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org

bdi_unregister is called by nfs_put_super which is only called by
generic_shutdown_super if ->s_root is not NULL.  So if we error out
in a circumstance where we called nfs_bdi_register (i.e. server !=
NULL) but have not set s_root, then we need to call bdi_unregister
explicitly in nfs_get_sb and various other *_get_sb() functions.
Signed-off-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

J.R. Okajima reports the following deadlock:

INFO: task kswapd0:305 blocked for more than 120 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kswapd0       D 0000000000000001     0   305      2 0x00000000
 ffff88001f21d4f0 0000000000000046 ffff88001fdea680 ffff88001f21c000
 ffff88001f21dfd8 ffff88001f21c000 ffff88001f21dfd8 ffff88001f21dfd8
 ffff88001fdea040 0000000000014c00 0000000000000001 ffff88001fdea040
Call Trace:
 [<ffffffff8146155d>] io_schedule+0x4d/0x70
 [<ffffffff810d2be5>] sync_page+0x65/0xa0
 [<ffffffff81461b12>] __wait_on_bit_lock+0x52/0xb0
 [<ffffffff810d2b80>] ? sync_page+0x0/0xa0
 [<ffffffff810d2b64>] __lock_page+0x64/0x70
 [<ffffffff81070ce0>] ? wake_bit_function+0x0/0x40
 [<ffffffff810df1d4>] truncate_inode_pages_range+0x344/0x4a0
 [<ffffffff810df340>] truncate_inode_pages+0x10/0x20
 [<ffffffff8112cbfe>] generic_delete_inode+0x15e/0x190
 [<ffffffff8112cc8d>] generic_drop_inode+0x5d/0x80
 [<ffffffff8112bb88>] iput+0x78/0x80
 [<ffffffff811bc908>] nfs_dentry_iput+0x38/0x50
 [<ffffffff811285f4>] dentry_iput+0x84/0x110
 [<ffffffff811286ae>] d_kill+0x2e/0x60
 [<ffffffff8112912a>] dput+0x7a/0x170
 [<ffffffff8111e925>] path_put+0x15/0x40
 [<ffffffff811c3a44>] __put_nfs_open_context+0xa4/0xb0
 [<ffffffff811cb5d0>] ? nfs_free_request+0x0/0x50
 [<ffffffff811c3b0b>] put_nfs_open_context+0xb/0x10
 [<ffffffff811cb5f9>] nfs_free_request+0x29/0x50
 [<ffffffff81234b7e>] kref_put+0x8e/0xe0
 [<ffffffff811cb594>] nfs_release_request+0x14/0x20
 [<ffffffff811cf769>] nfs_find_and_lock_request+0x89/0xa0
 [<ffffffff811d1180>] nfs_wb_page+0x80/0x110
 [<ffffffff811c0770>] nfs_release_page+0x70/0x90
 [<ffffffff810d18ee>] try_to_release_page+0x5e/0x80
 [<ffffffff810e1178>] shrink_page_list+0x638/0x860
 [<ffffffff810e19de>] shrink_zone+0x63e/0xc40

We can fix this by making the call to put_nfs_open_context() happen when we
actually remove the write request from the inode (which is done by the
nfsiod thread in this case).
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org

If the NFS_INO_REVAL_FORCED flag is set, that means that we don't yet have
an up to date attribute cache. Even if we hold a delegation, we must
put a GETATTR on the wire.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org

To avoid hangs in the svc_unregister(), on version 4 mounts
(and unmounts), when rpcbind is not running, make the nfs4 callback
program an 'hidden' service by setting the 'vs_hidden' flag in the
nfs4_callback_version structure.
Signed-off-by: NSteve Dickson <steved@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

I'll admit that it's unlikely for the first allocation to fail and
the second one to succeed.  I won't be offended if you ignore this
patch.
Signed-off-by: NDan Carpenter <error27@gmail.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Remove the redundant call to filemap_write_and_wait().
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Now that we have correct COMMIT semantics in writeback_single_inode, we can
reduce and simplify nfs_wb_all(). Also replace nfs_wb_nocommit() with a
call to filemap_write_and_wait(), which doesn't need to hold the
inode->i_mutex.

With that done, we can eliminate nfs_write_mapping() altogether.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

In all cases we should be able to just remove the request and call
cancel_dirty_page().
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Since nfs_scan_list() doesn't wait for locked pages, we have a race in
which it is possible to end up with an inode that needs to send a COMMIT,
but which does not have the I_DIRTY_DATASYNC flag set.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: NPeter Zijlstra <peterz@infradead.org>
Acked-by: NWu Fengguang <fengguang.wu@intel.com>

If the caller is doing a non-blocking flush, and there are still writebacks
pending on the wire, we can usually defer the COMMIT call until those
writes are done.

Also ensure that we honour the wbc->nonblocking flag.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

In order to know when we should do opportunistic commits of the unstable
writes, when the VM is doing a background flush, we add a field to count
the number of unstable writes.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The sole purpose of nfs_write_inode is to commit unstable writes, so
move it into fs/nfs/write.c, and make nfs_commit_inode static.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>