2ef47eb1 (NFS: Fix use of nfs_attr_use_mounted_on_fileid()) was a good
start to fixing a circular directory structure warning for NFS v4
"junctioned" mountpoints.  Unfortunately, further testing continued to
generate this error.

My server is configured like this:

anna@nfsd ~ % df
Filesystem      Size  Used Avail Use% Mounted on
/dev/vda1       9.1G  2.0G  6.5G  24% /
/dev/vdc1      1014M   33M  982M   4% /exports
/dev/vdc2      1014M   33M  982M   4% /exports/vol1
/dev/vdc3      1014M   33M  982M   4% /exports/vol1/vol2

anna@nfsd ~ % cat /etc/exports
/exports/          *(rw,async,no_subtree_check,no_root_squash)
/exports/vol1/     *(rw,async,no_subtree_check,no_root_squash)
/exports/vol1/vol2 *(rw,async,no_subtree_check,no_root_squash)

I've been running chown across the entire mountpoint twice in a row to
hit this problem.  The first run succeeds, but the second one fails with
the circular directory warning along with:

anna@client ~ % dmesg
[Apr 3 14:28] NFS: server 192.168.100.204 error: fileid changed
              fsid 0:39: expected fileid 0x100080, got 0x80

WHere 0x80 is the mountpoint's fileid and 0x100080 is the mounted-on
fileid.

This patch fixes the issue by requesting an updated mounted-on fileid
from the server during nfs_update_inode(), and then checking that the
fileid stored in the nfs_inode matches either the fileid or mounted-on
fileid returned by the server.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

v2: gracefully handle the case where some dentry pointers end up NULL
    and be more dilligent about zeroing out dentry pointers

We currently have a problem that SELinux policy is being enforced when
creating debugfs files. If a debugfs file is created as a side effect of
doing some syscall, then that creation can fail if the SELinux policy
for that process prevents it.

This seems wrong. We don't do that for files under /proc, for instance,
so Bruce has proposed a patch to fix that.

While discussing that patch however, Greg K.H. stated:

    "No kernel code should care / fail if a debugfs function fails, so
     please fix up the sunrpc code first."

This patch converts all of the sunrpc debugfs setup code to be void
return functins, and the callers to not look for errors from those
functions.

This should allow rpc_clnt and rpc_xprt creation to work, even if the
kernel fails to create debugfs files for some reason.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

Chuck pointed out a problem that crept in with commit 6ffa30d3 (nfs:
don't call blocking operations while !TASK_RUNNING). Linux counts tasks
in uninterruptible sleep against the load average, so this caused the
system's load average to be pinned at at least 1 when there was a
NFSv4.1+ mount active.

Not a huge problem, but it's probably worth fixing before we get too
many complaints about it. This patch converts the code back to use
TASK_INTERRUPTIBLE sleep, simply has it flush any signals on each loop
iteration. In practice no one should really be signalling this thread at
all, so I think this is reasonably safe.

With this change, there's also no need to game the hung task watchdog so
we can also convert the schedule_timeout call back to a normal schedule.

Cc: <stable@vger.kernel.org>
Reported-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Tested-by: Chuck Lever <chuck.lever@oracle.com>
Fixes: commit 6ffa30d3 (“nfs: don't call blocking . . .”)
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

At the very least, we should not be taking the i_mutex until after
checking if the server even supports ALLOCATE or DEALLOCATE, allowing
v4.0 or v4.1 to exit without potentially waiting on a lock.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

This patch adds a GETATTR to the end of ALLOCATE and DEALLOCATE
operations so we can set the updated inode size and change attribute
directly.  DEALLOCATE will still need to release pagecache pages, so
nfs42_proc_deallocate() now calls truncate_pagecache_range() before
contacting the server.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

The LAYOUTCOMMIT operation means different things to different layout types.
For blocks and objects, it is both a data and metadata consistency operation.
For files and flexfiles, it is only a metadata consistency operation.

This patch separates out the 2 cases, allowing the files/flexfiles layout
drivers to optimise away the data consistency calls to layoutcommit.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

We must not send a close or delegreturn that would result in a
return-on-close of the layout without ensuring that we've also
sent the necessary layoutcommit.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

If the caller does not specify the O_SYNC flag, then it is legitimate
to return from O_DIRECT without doing a pNFS layoutcommit operation.
However if the file is opened O_DIRECT|O_SYNC then we'd better get it
right.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

We don't just want to sync out buffered writes, but also O_DIRECT ones.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

File unlock needs to update both data and metadata on the NFS server
in order to act as a synchronisation point for other clients.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

Then apply it to nfs_setattr() and nfs_getattr().
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

pnfs_set_layoutcommit() and pnfs_commit_set_layoutcommit() are 100% identical
except for the function arguments. Refactor to eliminate the difference.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

If the NFS_INO_LAYOUTCOMMIT flag was unset, then we _must_ ensure that
we also reset the last write byte (lwb) for that layout. The current
code depends on us clearing the lwb when we clear NFS_INO_LAYOUTCOMMIT,
which is not the case when we call pnfs_clear_layoutcommit().
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

Minor optimisation for the case where the layout has return-on-close
enabled.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

I appear to have missed this when adding the ftrace probes.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

Make it easier to grep for these functions by name.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

The spec says that once all layouts that reference a given deviceid
have been returned, then we are only allowed to continue to cache
the deviceid if the metadata server supports notifications.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

We are only allowed to cache deviceinfo if the server supports notifications
and actually promises to call us back when changes occur. Right now, we
request those notifications, but then we don't check the server's reply.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

There really is no reason to do so.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

Use of synchronize_rcu() when unmounting and potentially freeing a lot
of deviceids is problematic. There really is no reason why we can't just
use kfree_rcu() here.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

This follows up "nfs: fix dio deadlock when O_DIRECT flag is flipped"
and removes the unnecessary CONFIG_NFS_SWAP switch.
Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

fix build-warning introduced by commit: f0eede10 ("SUNRPC: use
jiffies_to_msecs for converting jiffies") which did not fixup
the format properly (my bad).
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

Do so on the assumption that for most use cases, that list will turn into
a more or less LRU-ordered list, and so the list traversals in
nfs_client_return_marked_delegations() are likely to be shorter before
hitting a candidate to return.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

Use jiffies_to_msecs for converting jiffies as it handles all of the corner
cases reliably and also helps readability.
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

POLL_OUT isn't what callers of ->poll() are expecting to see; it's
actually __SI_POLL | 2 and it's a siginfo code, not a poll bitmap
bit...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: stable@vger.kernel.org
Cc: Bruce Fields <bfields@fieldses.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull USB fixes from Greg KH:
 "Here's a round of USB fixes for 4.0-rc3.

  Nothing major, the usual gadget, xhci and usb-serial fixes and a few
  new device ids as well.

  All have been in linux-next successfully"

* tag 'usb-4.0-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (36 commits)
  xhci: Workaround for PME stuck issues in Intel xhci
  xhci: fix reporting of 0-sized URBs in control endpoint
  usb: ftdi_sio: Add jtag quirk support for Cyber Cortex AV boards
  USB: ch341: set tty baud speed according to tty struct
  USB: serial: cp210x: Adding Seletek device id's
  USB: pl2303: disable break on shutdown
  USB: mxuport: fix null deref when used as a console
  USB: serial: clean up bus probe error handling
  USB: serial: fix port attribute-creation race
  USB: serial: fix tty-device error handling at probe
  USB: serial: fix potential use-after-free after failed probe
  USB: console: add dummy __module_get
  USB: ftdi_sio: add PIDs for Actisense USB devices
  Revert "USB: serial: make bulk_out_size a lower limit"
  cdc-acm: Add support for Denso cradle CU-321
  usb-storage: support for more than 8 LUNs
  uas: Add US_FL_NO_REPORT_OPCODES for JMicron JMS539
  USB: usbfs: don't leak kernel data in siginfo
  xhci: Clear the host side toggle manually when endpoint is 'soft reset'
  xhci: Allocate correct amount of scratchpad buffers
  ...

Pull tty/serial fixes from Greg KH:
 "Here are some tty and serial driver fixes for 4.0-rc3.

  Along with the atime fix that you know about, here are some other
  serial driver bugfixes as well.  Most notable is a wait_until_sent
  bugfix that was traced back to being around since before 2.6.12 that
  Johan has fixed up.

  All have been in linux-next successfully"

* tag 'tty-4.0-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  TTY: fix tty_wait_until_sent maximum timeout
  TTY: fix tty_wait_until_sent on 64-bit machines
  USB: serial: fix infinite wait_until_sent timeout
  TTY: bfin_jtag_comm: remove incorrect wait_until_sent operation
  net: irda: fix wait_until_sent poll timeout
  serial: uapi: Declare all userspace-visible io types
  serial: core: Fix iotype userspace breakage
  serial: sprd: Fix missing spin_unlock in sprd_handle_irq()
  console: Fix console name size mismatch
  tty: fix up atime/mtime mess, take four
  serial: 8250_dw: Fix get_mctrl behaviour
  serial:8250:8250_pci: delete unneeded quirk entries
  serial:8250:8250_pci: fix redundant entry report for WCH_CH352_2S
  Change email address for 8250_pci
  serial: 8250: Revert "tty: serial: 8250_core: read only RX if there is something in the FIFO"
  Revert "tty/serial: of_serial: add DT alias ID handling"

Pull staging driver fixes from Greg KH:
 "Here are some IIO and staging driver fixes for 4.0-rc3.

  Details are in the shortlog, nothing major, mostly IIO fixes for
  reported issues.

  All have been in linux-next successfully"

* tag 'staging-4.0-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (23 commits)
  staging: comedi: adv_pci1710: fix AI INSN_READ for non-zero channel
  staging: comedi: vmk80xx: remove "firmware version" kernel messages
  staging: comedi: comedi_isadma: fix "stalled" detect in comedi_isadma_disable_on_sample()
  iio: ak8975: fix AK09911 dependencies
  iio: common: ssp_sensors: Protect PM-only functions to kill warning
  IIO: si7020: Allocate correct amount of memory in devm_iio_device_alloc
  Revert "iio:humidity:si7020: fix pointer to i2c client"
  iio: light: gp2ap020a00f: Select REGMAP_I2C
  iio: light: jsa1212: Select REGMAP_I2C
  iio: ad5686: fix optional reference voltage declaration
  iio:adc:mcp3422 Fix incorrect scales table
  iio: mxs-lradc: fix iio channel map regression
  iio: imu: adis16400: Fix sign extension
  staging: iio: ad2s1200: Fix sign extension
  iio: mxs-lradc: only update the buffer when its conversions have finished
  iio: mxs-lradc: make ADC reads not unschedule touchscreen conversions
  iio: mxs-lradc: make ADC reads not disable touchscreen interrupts
  iio: mxs-lradc: separate touchscreen and buffer virtual channels
  iio: imu: inv_mpu6050: Prevent dereferencing NULL
  iio: iadc: wait_for_completion_timeout time in jiffies
  ...

Pull char/misc driver fixes from Greg KH:
 "Here are two char/misc fixes for 4.0-rc3.

  One is a reported binder driver fix needed due to a change in the mm
  core that happened in 4.0-rc1.  Another is a mei driver fix that
  resolves a reported issue in that driver.

  Both have been in linux-next for a while"

* tag 'char-misc-4.0-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  mei: make device disabled on stop unconditionally
  android: binder: fix binder mmap failures

Pull "code of conflict" from Greg KH:
 "This file tries to set the rational basis for our code reviews, gives
  some advice on how to conduct them, and provides an excalation channel
  for any kernel developers if they so desire it"

[ Let's see how this works ]

* tag 'cc-4.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  Code of Conflict

Pull i2c fixes from Wolfram Sang:
 "A set of updates and bugfixes for the new designware-baytrail driver.

  And a documentation bugfix"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: imx: add required clocks property to binding
  i2c: designware-baytrail: baytrail_i2c_acquire() might sleep
  i2c: designware-baytrail: cross-check lock functions
  i2c: designware-baytrail: fix sparse warnings
  i2c: designware-baytrail: fix typo in error path
  i2c: designware-baytrail: describe magic numbers

Pull slave-dmaengine fixes from Vinod Koul:
 "This contains small fixes spread across the drivers"

* 'fixes' of git://git.infradead.org/users/vkoul/slave-dma:
  dmaengine: mmp_pdma: fix warning about slave caps
  dmaengine: qcom_bam_dma: fix wrong register offsets
  dmaengine: bam-dma: fix a warning about missing capabilities
  dmaengine: ioatdma: workaround for incorrect DMACAP register
  dmaengine: at_xdmac: fix for chan conf simplification
  dmaengine: dw: don't handle interrupt when dmaengine is not used
  dma: mmp-tdma: refine dma disable and dma-pos update
  dmaengine: shdma: Move DMA stop to (runtime) suspend callbacks
  dmaenegine: mmp-pdma: fix irq handler overwrite physical chan issue

Pull arm64 fixes from Catalin Marinas:
 "arm64 and generic kernel/module.c (acked by Rusty) fixes for
  CONFIG_DEBUG_SET_MODULE_RONX"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  kernel/module.c: Update debug alignment after symtable generation
  arm64: Don't use is_module_addr in setting page attributes

Currently tty_wait_until_sent may take up to twice as long as the
requested timeout while waiting for driver and hardware buffers to
drain.

Fix this by taking the remaining number of jiffies after waiting for
driver buffers to drain into account so that the timeout actually
becomes a maximum timeout as it is documented to be.

Note that this specifically implies tighter timings when closing a port
as a consequence of actually honouring the port closing-wait setting
for drivers relying on tty_wait_until_sent_from_close (e.g. via
tty_port_close_start).
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix overflow bug in tty_wait_until_sent on 64-bit machines, where an
infinite timeout (0) would be passed to the underlying tty-driver's
wait_until_sent-operation as a negative timeout (-1), causing it to
return immediately.

This manifests itself for example as tcdrain() returning immediately,
drivers not honouring the drain flags when setting terminal attributes,
or even dropped data on close as a requested infinite closing-wait
timeout would be ignored.

The first symptom  was reported by Asier LLANO who noted that tcdrain()
returned prematurely when using the ftdi_sio usb-serial driver.

Fix this by passing 0 rather than MAX_SCHEDULE_TIMEOUT (LONG_MAX) to the
underlying tty driver.

Note that the serial-core wait_until_sent-implementation is not affected
by this bug due to a lucky chance (comparison to an unsigned maximum
timeout), and neither is the cyclades one that had an explicit check for
negative timeouts, but all other tty drivers appear to be affected.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Cc: stable <stable@vger.kernel.org>	# v2.6.12
Reported-by: ZIV-Asier Llano Palacios <asier.llano@cgglobal.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Make sure to handle an infinite timeout (0).

Note that wait_until_sent is currently never called with a 0-timeout
argument due to a bug in tty_wait_until_sent.

Fixes: dcf01050 ("USB: serial: add generic wait_until_sent
implementation")
Cc: stable <stable@vger.kernel.org>	# v3.10
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Remove incorrect and redundant wait_until_sent operation, which waits
for the driver buffer rather than any hardware buffers to drain,
something which is already taken care of by the tty layer (and
chars_in_buffer).
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

In case an infinite timeout (0) is requested, the irda wait_until_sent
implementation would use a zero poll timeout rather than the default
200ms.

Note that wait_until_sent is currently never called with a 0-timeout
argument due to a bug in tty_wait_until_sent.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Cc: stable <stable@vger.kernel.org>	# v2.6.12
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>