A guest can cause the backend driver to leak a kernel thread. Such
leaked threads hold references to the device, whichmakes the device
impossible to tear down. If shut down, the guest remains a zombie
domain, the xenwatch process hangs, and most xm commands will stop
working.

This patch tries to do the following for blkback:
    - identify/extract idempotent teardown operations,
    - add/move the invocation of said teardown operation
      right before we're about to allocate new resources in the
      Connected states.

[ linux-2.6.18-xen.hg 59f097ef181b ]
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Keir Fraser <keir@xen.org>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

Signed-off-by: K. Y. Srinivasan <ksrinivasan@novell.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

First cut at flushing blkback data when first connecting
blkback.  This should avoid the pygrub issues we are experiencing
in (RedHat bugzilla) 466681.

[ 2.6.18-xen.hg commit 63b4d7f56688 ]
Signed-off-by: Chris Lalancette <clalance@redhat.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

Since backend_info is hidden away now.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

Support dynamic resizing of virtual block devices. This patch supports
both file backed block devices as well as physical devices that can be
dynamically resized on the host side.
Signed-off-by: K. Y. Srinivasan <ksrinivasan@novell.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

Direct driver_data access is obsolete and will disappear.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

blkbk is rather generic for a modular distro style kernel.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

We neglect to check the return value of xenbus_register_backend
and take actions when that fails. This patch fixes that and adds
code to deal with those type of failures.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

Remove unused local prototype; group headers.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

Impact: build fix

I'm not sure if blkback should be using these functions, but in the
meantime export them to allow blkback to be a module.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

It's a user-mode header for users of /dev/evtchn
Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org>

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Conflicts:

	drivers/xen/Makefile

* 'for-linus' of git://oss.sgi.com/xfs/xfs:
  xfs: use proper interfaces for on-stack plugging
  xfs: fix xfs_debug warnings
  xfs: fix variable set but not used warnings
  xfs: convert log tail checking to a warning
  xfs: catch bad block numbers freeing extents.
  xfs: push the AIL from memory reclaim and periodic sync
  xfs: clean up code layout in xfs_trans_ail.c
  xfs: convert the xfsaild threads to a workqueue
  xfs: introduce background inode reclaim work
  xfs: convert ENOSPC inode flushing to use new syncd workqueue
  xfs: introduce a xfssyncd workqueue
  xfs: fix extent format buffer allocation size
  xfs: fix unreferenced var error in xfs_buf.c

Also, applied patch from Tony Luck that fixes ia64:
  xfs_destroy_workqueues() should not be tagged with__exit
in the branch before merging.

ia64 throws away .exit sections for the built-in CONFIG case, so routines
that are used in other circumstances should not be tagged as __exit.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: fix data corruption regression by reverting commit 6de9843d
  ext4: Allow indirect-block file to grow the file size to max file size
  ext4: allow an active handle to be started when freezing
  ext4: sync the directory inode in ext4_sync_parent()
  ext4: init timer earlier to avoid a kernel panic in __save_error_info
  jbd2: fix potential memory leak on transaction commit
  ext4: fix a double free in ext4_register_li_request
  ext4: fix credits computing for indirect mapped files
  ext4: remove unnecessary [cm]time update of quota file
  jbd2: move bdget out of critical section

* 'for-2.6.39' of git://linux-nfs.org/~bfields/linux:
  nfsd4: fix oops on lock failure
  nfsd: fix auth_domain reference leak on nlm operations

* 'spi/merge' of git://git.secretlab.ca/git/linux-2.6:
  dt/fsldma: fix build warning caused by of_platform_device changes
  spi: Fix race condition in stop_queue()
  gpio/pch_gpio: Fix output value of pch_gpio_direction_output()
  gpio/ml_ioh_gpio: Fix output value of ioh_gpio_direction_output()
  gpio/pca953x: fix error handling path in probe() call

In commit 13583b16 ("PCI: refactor io size calculation code") Ram
had a thinko in the refactorization of the code: the end result used the
variable 'align' for the bus alignment, but the original code used
'min_align'.

Since then, another use of that 'align' variable got introduced by
commit c8adf9a3 ("PCI: pre-allocate additional resources to devices
only after successful allocation of essential resources.")

Fix both of those uses to use 'min_align' as they should.

Daniel Hellstrom <daniel@gaisler.com>
Acked-by: Ram Pai <linuxram@us.ibm.com>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (34 commits)
  net: Add support for SMSC LAN9530, LAN9730 and LAN89530
  mlx4_en: Restoring RX buffer pointer in case of failure
  mlx4: Sensing link type at device initialization
  ipv4: Fix "Set rt->rt_iif more sanely on output routes."
  MAINTAINERS: add entry for Xen network backend
  be2net: Fix suspend/resume operation
  be2net: Rename some struct members for clarity
  pppoe: drop PPPOX_ZOMBIEs in pppoe_flush_dev
  dsa/mv88e6131: add support for mv88e6085 switch
  ipv6: Enable RFS sk_rxhash tracking for ipv6 sockets (v2)
  be2net: Fix a potential crash during shutdown.
  bna: Fix for handling firmware heartbeat failure
  can: mcp251x: Allow pass IRQ flags through platform data.
  smsc911x: fix mac_lock acquision before calling smsc911x_mac_read
  iwlwifi: accept EEPROM version 0x423 for iwl6000
  rt2x00: fix cancelling uninitialized work
  rtlwifi: Fix some warnings/bugs
  p54usb: IDs for two new devices
  wl12xx: fix potential buffer overflow in testmode nvs push
  zd1211rw: reset rx idle timer from tasklet
  ...

Commit 00006124, "dt/powerpc:
Eliminate users of of_platform_{,un}register_driver" forgot to convert
the type of structure passed into platform_device_register() when it
was converted from of_platform_device_register. Fix it.
Signed-off-by: Ira W. Snyder <iws@ovro.caltech.edu>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

Revert commit 6de9843d, since it
caused a data corruption regression with BitTorrent downloads.  Thanks
to Damien for discovering and bisecting to find the problem commit.

https://bugzilla.kernel.org/show_bug.cgi?id=32972Reported-by: Damien Grassart <damien@grassart.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

We can create 4402345721856 byte file with indirect block mapping.
However, if we grow an indirect-block file to the size with ftruncate(),
we can see an ext4 warning. The following patch fixes this problem.

How to reproduce:
# dd if=/dev/zero of=/mnt/mp1/hoge bs=1 count=0 seek=4402345721856
0+0 records in
0+0 records out
0 bytes (0 B) copied, 0.000221428 s, 0.0 kB/s
# tail -n 1 /var/log/messages
Nov 25 15:10:27 test kernel: EXT4-fs warning (device sda8): ext4_block_to_path:345: block 1074791436 > max in inode 12
Signed-off-by: Kazuya Mio <k-mio@sx.jp.nec.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

ext4_journal_start_sb() should not prevent an active handle from being
started due to s_frozen.  Otherwise, deadlock is easy to happen, below
is a situation.

================================================
     freeze         |       truncate
================================================
                    |  ext4_ext_truncate()
    freeze_super()  |   starts a handle
    sets s_frozen   |
                    |  ext4_ext_truncate()
                    |  holds i_data_sem
  ext4_freeze()     |
  waits for updates |
                    |  ext4_free_blocks()
                    |  calls dquot_free_block()
                    |
                    |  dquot_free_blocks()
                    |  calls ext4_dirty_inode()
                    |
                    |  ext4_dirty_inode()
                    |  trys to start an active
                    |  handle
                    |
                    |  block due to s_frozen
================================================
Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reported-by: Amir Goldstein <amir73il@users.sf.net>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>

ext4 has taken the stance that, in the absence of a journal,
when an fsync/fdatasync of an inode is done, the parent
directory should be sync'ed if this inode entry is new.
ext4_sync_parent(), which implements this, does indeed sync
the dirent pages for parent directories, but it does not
sync the directory *inode*.  This patch fixes this.

Also now return error status from ext4_sync_parent().

I tested this using a power fail test, which panics a
machine running a file server getting requests from a
client.  Without this patch, on about every other test run,
the server is missing many, many files that had been synced.
With this patch, on > 6 runs, I see zero files being lost.

Google-Bug-Id: 4179519
Signed-off-by: Curt Wohlgemuth <curtw@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

This patch adds support for SMSC's LAN9530, LAN9730 and LAN89530 USB
ethernet controllers to the existing smsc95xx driver by adding
their new USB VID/PID pairs.
Signed-off-by: Steve Glendinning <steve.glendinning@smsc.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
  ALSA: hda - Don't query connections for widgets have no connections
  ALSA: HDA: Fix single internal mic on ALC275 (Sony Vaio VPCSB1C5E)
  ALSA: hda - HDMI: Fix MCP7x audio infoframe checksums
  ALSA: usb-audio: define another USB ID for a buggy USB MIDI cable
  ALSA: HDA: Fix dock mic for Lenovo X220-tablet
  ASoC: format_register_str: Don't clip register values
  ASoC: PXA: Fix oops in __pxa2xx_pcm_prepare
  ASoC: zylonite: set .codec_dai_name in initializer

Lock stateid's can have access_bmap 0 if they were only partially
initialized (due to a failed lock request); handle that case in
free_generic_stateid.

------------[ cut here ]------------
kernel BUG at fs/nfsd/nfs4state.c:380!
invalid opcode: 0000 [#1] SMP
last sysfs file: /sys/kernel/mm/ksm/run
Modules linked in: nfs fscache md4 nls_utf8 cifs ip6table_filter ip6_tables ebtable_nat ebtables ipt_MASQUERADE iptable_nat nf_nat bridge stp llc nfsd lockd nfs_acl auth_rpcgss sunrpc ipv6 ppdev parport_pc parport pcnet32 mii pcspkr microcode i2c_piix4 BusLogic floppy [last unloaded: mperf]

Pid: 1468, comm: nfsd Not tainted 2.6.38+ #120 VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform
EIP: 0060:[<e24f180d>] EFLAGS: 00010297 CPU: 0
EIP is at nfs4_access_to_omode+0x1c/0x29 [nfsd]
EAX: ffffffff EBX: dd758120 ECX: 00000000 EDX: 00000004
ESI: dd758120 EDI: ddfe657c EBP: dd54dde0 ESP: dd54dde0
 DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
Process nfsd (pid: 1468, ti=dd54c000 task=ddc92580 task.ti=dd54c000)
Stack:
 dd54ddf0 e24f19ca 00000000 ddfe6560 dd54de08 e24f1a5d dd758130 deee3a20
 ddfe6560 31270000 dd54df1c e24f52fd 0000000f dd758090 e2505dd0 0be304cf
 dbb51d68 0000000e ddfe657c ddcd8020 dd758130 dd758128 dd7580d8 dd54de68
Call Trace:
 [<e24f19ca>] free_generic_stateid+0x1c/0x3e [nfsd]
 [<e24f1a5d>] release_lockowner+0x71/0x8a [nfsd]
 [<e24f52fd>] nfsd4_lock+0x617/0x66c [nfsd]
 [<e24e57b6>] ? nfsd_setuser+0x199/0x1bb [nfsd]
 [<e24e056c>] ? nfsd_setuser_and_check_port+0x65/0x81 [nfsd]
 [<c07a0052>] ? _cond_resched+0x8/0x1c
 [<c04ca61f>] ? slab_pre_alloc_hook.clone.33+0x23/0x27
 [<c04cac01>] ? kmem_cache_alloc+0x1a/0xd2
 [<c04835a0>] ? __call_rcu+0xd7/0xdd
 [<e24e0dfb>] ? fh_verify+0x401/0x452 [nfsd]
 [<e24f0b61>] ? nfsd4_encode_operation+0x52/0x117 [nfsd]
 [<e24ea0d7>] ? nfsd4_putfh+0x33/0x3b [nfsd]
 [<e24f4ce6>] ? nfsd4_delegreturn+0xd4/0xd4 [nfsd]
 [<e24ea2c9>] nfsd4_proc_compound+0x1ea/0x33e [nfsd]
 [<e24de6ee>] nfsd_dispatch+0xd1/0x1a5 [nfsd]
 [<e1d6e1c7>] svc_process_common+0x282/0x46f [sunrpc]
 [<e1d6e578>] svc_process+0xdc/0xfa [sunrpc]
 [<e24de0fa>] nfsd+0xd6/0x115 [nfsd]
 [<e24de024>] ? nfsd_shutdown+0x24/0x24 [nfsd]
 [<c0454322>] kthread+0x62/0x67
 [<c04542c0>] ? kthread_worker_fn+0x114/0x114
 [<c07a6ebe>] kernel_thread_helper+0x6/0x10
Code: eb 05 b8 00 00 27 4f 8d 65 f4 5b 5e 5f 5d c3 83 e0 03 55 83 f8 02 89 e5 74 17 83 f8 03 74 05 48 75 09 eb 09 b8 02 00 00 00 eb 0b <0f> 0b 31 c0 eb 05 b8 01 00 00 00 5d c3 55 89 e5 57 56 89 d6 8d
EIP: [<e24f180d>] nfs4_access_to_omode+0x1c/0x29 [nfsd] SS:ESP 0068:dd54dde0
---[ end trace 2b0bf6c6557cb284 ]---

The trace route is:

 -> nfsd4_lock()
   -> if (lock->lk_is_new) {
     -> alloc_init_lock_stateid()

        3739: stp->st_access_bmap = 0;

   ->if (status && lock->lk_is_new && lock_sop)
     -> release_lockowner()
      -> free_generic_stateid()
       -> nfs4_access_bmap_to_omode()
          -> nfs4_access_to_omode()

        380: BUG();   *****

This problem was introduced by 0997b173.
Reported-by: Mi Jinlong <mijinlong@cn.fujitsu.com>
Tested-by: Mi Jinlong <mijinlong@cn.fujitsu.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

* git://git.infradead.org/mtd-2.6:
  mtd: atmel_nand: use CPU I/O when buffer is in vmalloc(ed) region
  mtd: atmel_nand: modify test case for using DMA operations
  mtd: atmel_nand: fix support for CPUs that do not support DMA access
  mtd: atmel_nand: trivial: change DMA usage information trace
  mtd: mtdswap: fix printk format warning

* 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6:
  NFS: Change initial mount authflavor only when server returns NFS4ERR_WRONGSEC
  NFS: Fix a signed vs. unsigned secinfo bug
  Revert "net/sunrpc: Use static const char arrays"

Fix erroneous syscall kernel-doc comments in kernel/signal.c.
Reported-by: Matt Fleming <matt@console-pimps.org>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

* 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6:
  [S390] compile fix for latest binutils
  [S390] cio: prevent purging of CCW devices in the online state
  [S390] qdio: fix init sequence
  [S390] Fix parameter passing for smp_switch_to_cpu()
  [S390] oprofile s390: prevent stack corruption

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6:
  quota: Don't write quota info in dquot_commit()
  ext3: Fix writepage credits computation for ordered mode

Add proper blk_start_plug/blk_finish_plug pairs for the two places where
we issue buffer I/O, and remove the blk_flush_plug in xfs_buf_lock and
xfs_buf_iowait, given that context switches already flush the per-process
plugging lists.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>