expkey_parse() oopses when handling a 0 length export. This is easily
triggerable from usermode by writing 0 bytes into
'/proc/[proc id]/net/rpc/nfsd.fh/channel'.

Below is the log:

[ 1402.286893] BUG: unable to handle kernel paging request at ffff880077c49fff
[ 1402.287632] IP: [<ffffffff812b4b99>] expkey_parse+0x28/0x2e1
[ 1402.287632] PGD 2206063 PUD 1fdfd067 PMD 1ffbc067 PTE 8000000077c49160
[ 1402.287632] Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
[ 1402.287632] CPU 1
[ 1402.287632] Pid: 20198, comm: trinity Not tainted 3.2.0-rc2-sasha-00058-gc65cd37 #6
[ 1402.287632] RIP: 0010:[<ffffffff812b4b99>]  [<ffffffff812b4b99>] expkey_parse+0x28/0x2e1
[ 1402.287632] RSP: 0018:ffff880077f0fd68  EFLAGS: 00010292
[ 1402.287632] RAX: ffff880077c49fff RBX: 00000000ffffffea RCX: 0000000001043400
[ 1402.287632] RDX: 0000000000000000 RSI: ffff880077c4a000 RDI: ffffffff82283de0
[ 1402.287632] RBP: ffff880077f0fe18 R08: 0000000000000001 R09: ffff880000000000
[ 1402.287632] R10: 0000000000000000 R11: 0000000000000001 R12: ffff880077c4a000
[ 1402.287632] R13: ffffffff82283de0 R14: 0000000001043400 R15: ffffffff82283de0
[ 1402.287632] FS:  00007f25fec3f700(0000) GS:ffff88007d400000(0000) knlGS:0000000000000000
[ 1402.287632] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 1402.287632] CR2: ffff880077c49fff CR3: 0000000077e1d000 CR4: 00000000000406e0
[ 1402.287632] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 1402.287632] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[ 1402.287632] Process trinity (pid: 20198, threadinfo ffff880077f0e000, task ffff880077db17b0)
[ 1402.287632] Stack:
[ 1402.287632]  ffff880077db17b0 ffff880077c4a000 ffff880077f0fdb8 ffffffff810b411e
[ 1402.287632]  ffff880000000000 ffff880077db17b0 ffff880077c4a000 ffffffff82283de0
[ 1402.287632]  0000000001043400 ffffffff82283de0 ffff880077f0fde8 ffffffff81111f63
[ 1402.287632] Call Trace:
[ 1402.287632]  [<ffffffff810b411e>] ? lock_release+0x1af/0x1bc
[ 1402.287632]  [<ffffffff81111f63>] ? might_fault+0x97/0x9e
[ 1402.287632]  [<ffffffff81111f1a>] ? might_fault+0x4e/0x9e
[ 1402.287632]  [<ffffffff81a8bcf2>] cache_do_downcall+0x3e/0x4f
[ 1402.287632]  [<ffffffff81a8c950>] cache_write.clone.16+0xbb/0x130
[ 1402.287632]  [<ffffffff81a8c9df>] ? cache_write_pipefs+0x1a/0x1a
[ 1402.287632]  [<ffffffff81a8c9f8>] cache_write_procfs+0x19/0x1b
[ 1402.287632]  [<ffffffff8118dc54>] proc_reg_write+0x8e/0xad
[ 1402.287632]  [<ffffffff8113fe81>] vfs_write+0xaa/0xfd
[ 1402.287632]  [<ffffffff8114142d>] ? fget_light+0x35/0x9e
[ 1402.287632]  [<ffffffff8113ff8b>] sys_write+0x48/0x6f
[ 1402.287632]  [<ffffffff81bbdb92>] system_call_fastpath+0x16/0x1b
[ 1402.287632] Code: c0 c9 c3 55 48 63 d2 48 89 e5 48 8d 44 32 ff 41 57 41 56 41 55 41 54 53 bb ea ff ff ff 48 81 ec 88 00 00 00 48 89 b5 58 ff ff ff
[ 1402.287632]  38 0a 0f 85 89 02 00 00 c6 00 00 48 8b 3d 44 4a e5 01 48 85
[ 1402.287632] RIP  [<ffffffff812b4b99>] expkey_parse+0x28/0x2e1
[ 1402.287632]  RSP <ffff880077f0fd68>
[ 1402.287632] CR2: ffff880077c49fff
[ 1402.287632] ---[ end trace 368ef53ff773a5e3 ]---

Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Cc: linux-nfs@vger.kernel.org
Cc: stable@kernel.org
Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

The semantic patch that makes this change is available
in scripts/coccinelle/api/memdup.cocci.
Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Address the possible performance regression mentioned in "nfsd4: hash
lockowners to simplify RELEASE_LOCKOWNER" by providing a separate
(lockowner, inode) hash.

Really, I doubt this matters much, but I think it's likely we'll change
these data structures here and I'd rather that the need for (owner,
inode) lookups be well-documented.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Now that they're used in the same way, it's a little simpler to put open
and lock owners in the same hash table, and I can't see a reason not to.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Hash lockowners on just the owner string rather than on (owner, inode).
This makes the owner-string lookup needed for RELEASE_LOCKOWNER simpler
(currently it's doing at a linear search through the entire hash
table!).  That may come at the expense of making (owner, inode) lookups
more expensive if a client reuses the same lockowner across multiple
files.  We might add a separate lookup for that.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

The close parenthesis was hard to find with it spaced so far over.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
[bfields@redhat.com: get all these lines under 80 chars while we're here]
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

init_nfsd() was calling free_slabs() during cleanup code, but the call
to init_slabs() was hidden in nfsd4_state_init().  This could be
confusing to people unfamiliar with the code.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

This script provides a convenient way to use the NFSD fault injection
framework.  Fault injection writes to dmesg using the KERN_INFO flag, so
this script will compare the before and after output of `dmesg` to show
the user what happened
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Fault injection on the NFS server makes it easier to test the client's
state manager and recovery threads.  Simulating errors on the server is
easier than finding the right conditions that cause them naturally.

This patch uses debugfs to add a simple framework for fault injection to
the server.  This framework is a config option, and can be enabled
through CONFIG_NFSD_FAULT_INJECTION.  Assuming you have debugfs mounted
to /sys/debug, a set of files will be created in /sys/debug/nfsd/.
Writing to any of these files will cause the corresponding action and
write a log entry to dmesg.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Instead of creating a new lockowner and stateid for every
open_to_lockowner call, reuse the existing lockowner if it exists.
Reported-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

I'd rather the "ignore clientid in sessions case" rule be enforced in
just one place.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Lockowners are looked up by file as well as by owner, but we were
forgetting to do a comparison on the file.  This could cause an
incorrect result from lockt.

(Note looking up the inode from the lockowner is pretty awkward here.
The data structures need fixing.)

Cc: stable@kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

Neil hasn't really been at all active as a maintainer for some years now.
So move his maintainership to CREDITS
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

.. with new name.  Because nothing says "really solid kernel release"
like naming it after an extinct animal that just happened to be in the
news lately.

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap: (31 commits)
  ARM: OMAP: Fix export.h or module.h includes
  ARM: OMAP: omap_device: Include linux/export.h
  ARM: OMAP2: Fix H4 matrix keyboard warning
  ARM: OMAP1: Remove unused omap-alsa.h
  ARM: OMAP1: Fix warnings about enabling 32 KiHz timer
  ARM: OMAP2+: timer: Remove omap_device_pm_latency
  ARM: OMAP2+: clock data: Remove redundant timer clkdev
  ARM: OMAP: Devkit8000: Remove double omap_mux_init_gpio
  ARM: OMAP: usb: musb: OMAP: Delete unused function
  MAINTAINERS: Update linux-omap git repository
  ARM: OMAP: change get_context_loss_count ret value to int
  ARM: OMAP4: hsmmc: configure SDMMC1_DR0 properly
  ARM: OMAP4: hsmmc: Fix Pbias configuration on regulator OFF
  ARM: OMAP3: hwmod: fix variant registration and remove SmartReflex from common list
  ARM: OMAP: I2C: Fix omap_register_i2c_bus() return value on success
  ARM: OMAP: dmtimer: Include linux/module.h
  ARM: OMAP2+: l3-noc: Include linux/module.h
  ARM: OMAP2+: devices: Fixes for McPDM
  ARM: OMAP: Fix errors and warnings when building for one board
  ARM: OMAP3: PM: restrict erratum i443 handling to OMAP3430 only
  ...

Mountpoint crossing is similar to following procfs symlinks - we do
not get ->d_revalidate() called for dentry we have arrived at, with
unpleasant consequences for NFS4.

Simple way to reproduce the problem in mainline:

    cat >/tmp/a.c <<'EOF'
    #include <unistd.h>
    #include <fcntl.h>
    #include <stdio.h>
    main()
    {
            struct flock fl = {.l_type = F_RDLCK, .l_whence = SEEK_SET, .l_len = 1};
            if (fcntl(0, F_SETLK, &fl))
                    perror("setlk");
    }
    EOF
    cc /tmp/a.c -o /tmp/test

then on nfs4:

    mount --bind file1 file2
    /tmp/test < file1		# ok
    /tmp/test < file2		# spews "setlk: No locks available"...

What happens is the missing call of ->d_revalidate() after mountpoint
crossing and that's where NFS4 would issue OPEN request to server.

The fix is simple - treat mountpoint crossing the same way we deal with
following procfs-style symlinks.  I.e.  set LOOKUP_JUMPED...

Cc: stable@kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf top: Fix live annotation in the --stdio interface
  perf top tui: Don't recalc column widths considering just the first page
  perf report: Add progress bar when processing time ordered events
  perf hists browser: Warn about lost events
  perf tools: Fix a typo of command name as trace-cmd
  perf hists: Fix recalculation of total_period when sorting entries
  perf header: Fix build on old systems
  perf ui browser: Handle K_RESIZE in dialog windows
  perf ui browser: No need to switch char sets that often
  perf hists browser: Use K_TIMER
  perf ui: Rename ui__warning_paranoid to ui__error_paranoid
  perf ui: Reimplement the popup windows using libslang
  perf ui: Reimplement ui__popup_menu using ui__browser
  perf ui: Reimplement ui_helpline using libslang
  perf ui: Improve handling sigwinch a bit
  perf ui progress: Reimplement using slang
  perf evlist: Fix grouping of multiple events

Commit 32aaeffb (Merge branch
'modsplit-Oct31_2011'...) caused some build errors. Fix these
and make sure we always have export.h or module.h included
for MODULE_ and EXPORT_SYMBOL users:

$ grep -rl ^MODULE_ arch/arm/*omap*/*.c | xargs \
  grep -L linux/module.h
  arch/arm/mach-omap2/dsp.c
  arch/arm/mach-omap2/mailbox.c
  arch/arm/mach-omap2/omap-iommu.c
  arch/arm/mach-omap2/smartreflex.c

Also check we either have export.h or module.h included
for the files exporting symbols:

$ grep -rl EXPORT_SYMBOL arch/arm/*omap*/*.c | xargs \
  grep -L linux/export.h | xargs grep -L linux/module.h

Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Tony Lindgren <tony@atomide.com>

Include linux/export.h to fix below build warning:

  CC      arch/arm/plat-omap/omap_device.o
arch/arm/plat-omap/omap_device.c:1055: warning: data definition has no type or storage class
arch/arm/plat-omap/omap_device.c:1055: warning: type defaults to 'int' in declaration of 'EXPORT_SYMBOL'
arch/arm/plat-omap/omap_device.c:1055: warning: parameter names (without types) in function declaration
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (47 commits)
  forcedeth: fix a few sparse warnings (variable shadowing)
  forcedeth: Improve stats counters
  forcedeth: remove unneeded stats updates
  forcedeth: Acknowledge only interrupts that are being processed
  forcedeth: fix race when unloading module
  MAINTAINERS/rds: update maintainer
  wanrouter: Remove kernel_lock annotations
  usbnet: fix oops in usbnet_start_xmit
  ixgbe: Fix compile for kernel without CONFIG_PCI_IOV defined
  etherh: Add MAINTAINERS entry for etherh
  bonding: comparing a u8 with -1 is always false
  sky2: fix regression on Yukon Optima
  netlink: clarify attribute length check documentation
  netlink: validate NLA_MSECS length
  i825xx:xscale:8390:freescale: Fix Kconfig dependancies
  macvlan: receive multicast with local address
  tg3: Update version to 3.121
  tg3: Eliminate timer race with reset_task
  tg3: Schedule at most one tg3_reset_task run
  tg3: Obtain PCI function number from device
  ...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This fixes the following sparse warnings:
drivers/net/ethernet/nvidia/forcedeth.c:2113:7: warning: symbol 'size' shadows an earlier one
drivers/net/ethernet/nvidia/forcedeth.c:2102:6: originally declared here
drivers/net/ethernet/nvidia/forcedeth.c:2155:7: warning: symbol 'size' shadows an earlier one
drivers/net/ethernet/nvidia/forcedeth.c:2102:6: originally declared here
drivers/net/ethernet/nvidia/forcedeth.c:2227:7: warning: symbol 'size' shadows an earlier one
drivers/net/ethernet/nvidia/forcedeth.c:2215:6: originally declared here
drivers/net/ethernet/nvidia/forcedeth.c:2271:7: warning: symbol 'size' shadows an earlier one
drivers/net/ethernet/nvidia/forcedeth.c:2215:6: originally declared here
drivers/net/ethernet/nvidia/forcedeth.c:2986:20: warning: symbol 'addr' shadows an earlier one
drivers/net/ethernet/nvidia/forcedeth.c:2963:6: originally declared here
Signed-off-by: David Decotigny <david.decotigny@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Rx byte count was off; instead use the hardware's count.  Tx packet
count was counting pre-TSO packets; instead count on-the-wire packets.
Report hardware dropped frame count as rx_fifo_errors.

- The count of transmitted packets reported by the forcedeth driver
  reports pre-TSO (TCP Segmentation Offload) packet counts and not the
  count of the number of packets sent on the wire. This change fixes
  the forcedeth driver to report the correct count. Fixed the code by
  copying the count stored in the NIC H/W to the value reported by the
  driver.

- Count rx_drop_frame errors as rx_fifo_errors:
  We see a lot of rx_drop_frame errors if we disable the rx bottom-halves
  for too long.  Normally, rx_fifo_errors would be counted in this case.
  The rx_drop_frame error count is private to forcedeth and is not
  reported by ifconfig or sysfs.  The rx_fifo_errors count is currently
  unused in the forcedeth driver.  It is reported by ifconfig as overruns.
  This change reports rx_drop_frame errors as rx_fifo_errors.
Signed-off-by: David Decotigny <david.decotigny@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Function ndo_get_stats() updates most of the stats from hardware
registers, making the manual updates un-needed. This change removes
these manual updates. Main exception is rx_missed_errors which needs
manual update.

Another exception is rx_packets, still updated manually in this commit
to make sure this patch doesn't change behavior of driver. This will
be addressed by a future patch.
Signed-off-by: David Decotigny <david.decotigny@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This is to avoid a race, accidentally acknowledging an interrupt that
we didn't notice and won't immediately process.  This is based solely
on code inspection; it is not known if there was an actual bug here.
Signed-off-by: David Decotigny <david.decotigny@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When forcedeth module is unloaded, there exists a path that can lead
to mod_timer() after del_timer_sync(), causing an oops. This patch
short-circuits this unneeded path, which originates in
nv_get_ethtool_stats().

Tested:
  x86_64 16-way + 3 ethtool -S infinite loops + 100Mbps incoming traffic
  + rmmod/modprobe/ifconfig in a loop

Initial-Author: Salman Qazi <sqazi@google.com>
Discussion: http://patchwork.ozlabs.org/patch/123548/Signed-off-by: David Decotigny <david.decotigny@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Reported-by: Witold Baryluk <baryluk@smp.if.uj.edu.pl>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

since it uses the module facilities.
Reported-by: Witold Baryluk <baryluk@smp.if.uj.edu.pl>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

For the files which are not themselves modular, we can change
them to include only the smaller export.h since all they are
doing is looking for EXPORT_SYMBOL.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

These files didn't exist at the time of the module.h split, and
so were not fixed by the commits on that baseline.  Since they use
the EXPORT_SYMBOL and/or THIS_MODULE macros, they will need the
new export.h file included that provides them.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

update for the actual maintainer
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The BKL is gone, these annotations are useless.
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch fixes the bug added in commit v3.1-rc7-1055-gf9b491ec
SKB can be NULL at this point, at least for cdc-ncm.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix compiler errors and warnings with CONFIG_PCI_IOV defined and not
defined.
Signed-off-by: Greg Rose <gregory.v.rose@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux:
  cpuidle: Single/Global registration of idle states
  cpuidle: Split cpuidle_state structure and move per-cpu statistics fields
  cpuidle: Remove CPUIDLE_FLAG_IGNORE and dev->prepare()
  cpuidle: Move dev->last_residency update to driver enter routine; remove dev->last_state
  ACPI: Fix CONFIG_ACPI_DOCK=n compiler warning
  ACPI: Export FADT pm_profile integer value to userspace
  thermal: Prevent polling from happening during system suspend
  ACPI: Drop ACPI_NO_HARDWARE_INIT
  ACPI atomicio: Convert width in bits to bytes in __acpi_ioremap_fast()
  PNPACPI: Simplify disabled resource registration
  ACPI: Fix possible recursive locking in hwregs.c
  ACPI: use kstrdup()
  mrst pmu: update comment
  tools/power turbostat: less verbose debugging

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: (40 commits)
  vmwgfx: Snoop DMA transfers with non-covering sizes
  vmwgfx: Move the prefered mode first in the list
  vmwgfx: Unreference surface on cursor error path
  vmwgfx: Free prefered mode on error path
  vmwgfx: Use pointer return error codes
  vmwgfx: Fix hw cursor position
  vmwgfx: Infrastructure for explicit placement
  vmwgfx: Make the preferred autofit mode have a 60Hz vrefresh
  vmwgfx: Remove screen object active list
  vmwgfx: Screen object cleanups
  drm/radeon/kms: consolidate GART code, fix segfault after GPU lockup V2
  drm/radeon/kms: don't poll forever if MC GDDR link training fails
  drm/radeon/kms: fix DP setup on TRAVIS bridges
  drm/radeon/kms: set HPD polarity in hpd_init()
  drm/radeon/kms: add MSI module parameter
  drm/radeon/kms: Add MSI quirk for Dell RS690
  drm/radeon/kms: Add MSI quirk for HP RS690
  drm/radeon/kms: split MSI check into a separate function
  vmwgfx: Reinstate the update_layout ioctl
  drm/radeon/kms: always do extended edid probe
  ...

* 'urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux:
  writeback: fix uninitialized task_ratelimit