When do block-attach/block-detach test with below steps, umount hangs
in the guest. Furthermore shutdown ends up being stuck when umounting file-systems.

1. start guest.
2. attach new block device by xm block-attach in Dom0.
3. mount new disk in guest.
4. execute xm block-detach to detach the block device in dom0 until timeout
5. Any request to the disk will hung.

Root cause:
This issue is caused when setting backend device's state to
'XenbusStateClosing', which sends to the frontend the XenbusStateClosing
notification. When frontend receives the notification it tries to release
the disk in blkfront_closing(), but at that moment the disk is still in use
by guest, so frontend refuses to close. Specifically it sets the disk state to
XenbusStateClosing and sends the notification to backend - when backend receives the
event, it disconnects the vbd from real device, and sets the vbd device state to
XenbusStateClosing. The backend disconnects the real device/file, and any IO
requests to the disk in guest will end up in ether, leaving disk DEAD and set to
XenbusStateClosing. When the guest wants to disconnect the disk, umount will
hang on blkif_release()->xlvbd_release_gendisk() as it is unable to send any IO
to the disk, which prevents clean system shutdown.

Solution:
Don't disconnect backend until frontend state switched to XenbusStateClosed.
Signed-off-by: Joe Jin <joe.jin@oracle.com>
Cc: Daniel Stodden <daniel.stodden@citrix.com>
Cc: Jens Axboe <jaxboe@fusionio.com>
Cc: Annie Li <annie.li@oracle.com>
Cc: Ian Campbell <Ian.Campbell@eu.citrix.com>
[v1: Modified description a bit]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

With the frontend having Xen but the backend not, it just looks odd:

  <*>   Xen virtual block device support
  <*>   Block-device backend driver

Fix it to have the 'Xen' in front of it.
Reported-by: Sander Eikelenboom <linux@eikelenboom.it>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Avoid telling users to use xvde and onwards when using xvde.
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

These were intended to avoid the namespace clash when representing
emulated IDE and SCSI devices. However that seems to confuse users
more than expected (a disk defined as sda becomes xvde).
So for now go back to the scheme which does no adjustments. This
will break when mixing IDE and SCSI names in the configuration of
guests but should be by now expected.
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Add xen-backend:vbd module alias to the xen-blkback module. This allows
automatic loading of the module.
Signed-off-by: Bastian Blank <waldi@debian.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Running RING_FINAL_CHECK_FOR_REQUESTS from make_response is a bad
idea. It means that in-flight I/O is essentially blocking continued
batches. This essentially kills throughput on frontends which unplug
(or even just notify) early and rightfully assume addtional requests
will be picked up on time, not synchronously.
Signed-off-by: Daniel Stodden <daniel.stodden@citrix.com>
[v1: Rebased and fixed compile problems]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

copy_from/to_user() and blk_rq_map_user() want __user pointer.
This patch fixes following warnings from sparse:

   CHECK   block/bsg.c
 block/bsg.c:185:38: warning: incorrect type in argument 2 (different address spaces)
 block/bsg.c:185:38:    expected void const [noderef] <asn:1>*from
 block/bsg.c:185:38:    got void *<noident>
 block/bsg.c:295:58: warning: incorrect type in argument 4 (different address spaces)
 block/bsg.c:295:58:    expected void [noderef] <asn:1>*<noident>
 block/bsg.c:295:58:    got void *[assigned] dxferp
 block/bsg.c:311:52: warning: incorrect type in argument 4 (different address spaces)
 block/bsg.c:311:52:    expected void [noderef] <asn:1>*<noident>
 block/bsg.c:311:52:    got void *[assigned] dxferp
 block/bsg.c:448:37: warning: incorrect type in argument 1 (different address spaces)
 block/bsg.c:448:37:    expected void [noderef] <asn:1>*dst
 block/bsg.c:448:37:    got void *<noident>
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

Second condition in OR always implies first condition is false
thus bytes_read in the second is not needed. The same goes to
bytes_written.
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

POLLOUT should be returned only if bd->queued_cmds < bd->max_queue
so that bsg_alloc_command() can proceed.
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6:
  SLAB: Record actual last user of freed objects.
  slub: always align cpu_slab to honor cmpxchg_double requirement

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  ceph: unwind canceled flock state
  ceph: fix ENOENT logic in striped_read
  ceph: fix short sync reads from the OSD
  ceph: fix sync vs canceled write
  ceph: use ihold when we already have an inode ref

Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  rtc: Staticize non-exported __rtc_set_alarm()
  rtc: Fix ioctl error path return
  ptp: Fix some locking bugs in ptp_read()
  ptp: Return -EFAULT on copy_to_user() errors

Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  ftrace: Revert 8ab2b7ef ftrace: Remove unnecessary disabling of irqs
  kprobes/trace: Fix kprobe selftest for gcc 4.6
  ftrace: Fix possible undefined return code
  oprofile, dcookies: Fix possible circular locking dependency
  oprofile: Fix locking dependency in sync_start()
  oprofile: Free potentially owned tasks in case of errors
  oprofile, x86: Add comments to IBS LVT offset initialization

Merge branches 'x86-urgent-for-linus' and 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: devicetree: Add missing early_init_dt_setup_initrd_arch stub
  x86: cpu-hotplug: Prevent softirq wakeup on wrong CPU

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  genirq: Prevent potential NULL dereference in irq_set_irq_wake()

* 'spi/merge' of git://git.secretlab.ca/git/linux-2.6:
  spi-pl022: Add missing return value update

Merge branch 's5p-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung

* 's5p-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung:
  ARM: S3C2410: remove the now empty mach-s3c2410/irq.c
  ARM: S3C24XX: Move s3c24xx_irq_syscore_ops to plat-s3c24xx/irq.c
  ARM: S3C24xx: Fix missing struct for s3c2410_dma_chan
  ARM: SAMSUNG: Remove unused onenand plat functions
  ARM: EXYNOS4: Remove compiler warning on exynos4_pwm4_resume
  ARM: S5P: Fix compilation error for exynos4_defconfig
  ARM: S5P: Should be S3C_VA_USB_HSPHY instead of S5P_VA_XX
  ARM: S5P64X0: Fix SPI platform device name
  ARM: S5PV210: Fix possible null pointer dereference

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2:
  nilfs2: fix problem in setting checkpoint interval
  nilfs2: fix missing block address termination in btree node shrinking
  nilfs2: fix incorrect block address termination in node concatenation

Return error on out of range cpsdvsr value.
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable:
  Btrfs: use join_transaction in btrfs_evict_inode()
  Btrfs - use %pU to print fsid
  Btrfs: fix extent state leak on failed nodatasum reads
  btrfs: fix unlocked access of delalloc_inodes
  Btrfs: avoid stack bloat in btrfs_ioctl_fs_info()
  btrfs: remove 64bit alignment padding to allow extent_buffer to fit into one fewer cacheline
  Btrfs: clear current->journal_info on async transaction commit
  Btrfs: make sure to recheck for bitmaps in clusters
  btrfs: remove unneeded includes from scrub.c
  btrfs: reinitialize scrub workers
  btrfs: scrub: errors in tree enumeration
  Btrfs: don't map extent buffer if path->skip_locking is set
  Btrfs: unlock the trans lock properly
  Btrfs: don't map extent buffer if path->skip_locking is set
  Btrfs: fix duplicate checking logic
  Btrfs: fix the allocator loop logic
  Btrfs: fix bitmap regression
  Btrfs: don't commit the transaction if we dont have enough pinned bytes
  Btrfs: noinline the cluster searching functions
  Btrfs: cache bitmaps when searching for a cluster

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
  ALSA: hda: Fix inaudible internal speakers on CyberpowerPC Gamer Xplorer N57001 laptop
  ALSA: Use %pV for snd_printk()
  ALSA: hda - Fix initialization of hp pins with master_mute in Realtek
  ALSA: hda - Fix invalid unsol tag for some alc262 model quirks
  ASoC: SAMSUNG: Fix the incorrect referencing of I2SCON register
  ASoC: snd_soc_new_{mixer,mux,pga} make sure to use right DAPM context
  ASoC: fsl: fix initialization of DMA buffers
  ASoC: WM8804 does not support sample rates below 32kHz
  ASoC: Fix WM8962 headphone volume update for use of advanced caches
  ASoC: Blackfin: bf5xx-ad1836: Fix codec device name
  ALSA: hda: Fix quirk for Dell Inspiron 910
  ASoC: AD1836: Fix setting the PCM format
  ASoC: Check for NULL register bank in snd_soc_get_cache_val()
  ASoC: Add missing break in WM8915 FLL source selection
  ASoC: Only update SYSCLK_ENA when pausing WM8915 SYSCLK
  ASoC: atmel_ssc: Don't try to free ssc if request failed

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide-2.6:
  ide-cd: signedness warning fix again

* 'gpio/merge' of git://git.secretlab.ca/git/linux-2.6:
  gpio/basic_mmio: add missing include of spinlock_types.h
  gpio/nomadik: fix sleepmode for elder Nomadik

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (55 commits)
  ISDN, hfcsusb: Don't leak in hfcsusb_ph_info()
  netpoll: call dev_put() on error in netpoll_setup()
  net: ep93xx_eth: fix DMA API violations
  net: ep93xx_eth: drop GFP_DMA from call to dma_alloc_coherent()
  net: ep93xx_eth: allocate buffers using kmalloc()
  net: ep93xx_eth: pass struct device to DMA API functions
  ep93xx: set DMA masks for the ep93xx_eth
  vlan: Fix the ingress VLAN_FLAG_REORDER_HDR check
  dl2k: EEPROM CRC calculation wrong endianess on bigendian machine
  NET: am79c961: fix assembler warnings
  NET: am79c961: ensure multicast filter is correctly set at open
  NET: am79c961: ensure asm() statements are marked volatile
  ethtool.h: fix typos
  ep93xx_eth: Update MAINTAINERS
  ipv4: Fix packet size calculation for raw IPsec packets in __ip_append_data
  netpoll: prevent netpoll setup on slave devices
  net: pmtu_expires fixes
  gianfar:localized filer table
  iwlegacy: fix channel switch locking
  mac80211: fix IBSS teardown race
  ...

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6:
  AppArmor: Fix sleep in invalid context from task_setrlimit

We leak the memory allocated to 'phi' when the variable goes out of scope
in hfcsusb_ph_info().
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

There is a dev_put(ndev) missing on an error path.  This was
introduced in 0c1ad04a "netpoll: prevent netpoll setup on slave
devices".
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Russell King said:
>
> So, to summarize what its doing:
>
> 1. It allocates buffers for rx and tx.
> 2. It maps them with dma_map_single().
>       This transfers ownership of the buffer to the DMA device.
> 3. In ep93xx_xmit,
> 3a. It copies the data into the buffer with skb_copy_and_csum_dev()
>       This violates the DMA buffer ownership rules - the CPU should
>       not be writing to this buffer while it is (in principle) owned
>       by the DMA device.
> 3b. It then calls dma_sync_single_for_cpu() for the buffer.
>       This transfers ownership of the buffer to the CPU, which surely
>       is the wrong direction.
> 4. In ep93xx_rx,
> 4a. It calls dma_sync_single_for_cpu() for the buffer.
>       This at least transfers the DMA buffer ownership to the CPU
>       before the CPU reads the buffer
> 4b. It then uses skb_copy_to_linear_data() to copy the data out.
>       At no point does it transfer ownership back to the DMA device.
> 5. When the driver is removed, it dma_unmap_single()'s the buffer.
>       This transfers ownership of the buffer to the CPU.
> 6. It frees the buffer.
>
> While it may work on ep93xx, it's not respecting the DMA API rules,
> and with DMA debugging enabled it will probably encounter quite a few
> warnings.

This patch fixes these violations.
Signed-off-by: Mika Westerberg <mika.westerberg@iki.fi>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Tested-by: Petr Stetiar <ynezz@true.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit a197b59a (mm: fail GFP_DMA allocations when ZONE_DMA is not
configured) made page allocator to return NULL if GFP_DMA is set but
CONFIG_ZONE_DMA is disabled.

This causes ep93xx_eth to fail:

 WARNING: at mm/page_alloc.c:2251 __alloc_pages_nodemask+0x11c/0x638()
 Modules linked in:
 [<c0035498>] (unwind_backtrace+0x0/0xf4) from [<c0043da4>] (warn_slowpath_common+0x48/0x60)
 [<c0043da4>] (warn_slowpath_common+0x48/0x60) from [<c0043dd8>] (warn_slowpath_null+0x1c/0x24)
 [<c0043dd8>] (warn_slowpath_null+0x1c/0x24) from [<c0083b6c>] (__alloc_pages_nodemask+0x11c/0x638)
 [<c0083b6c>] (__alloc_pages_nodemask+0x11c/0x638) from [<c00366fc>] (__dma_alloc+0x8c/0x3ec)
 [<c00366fc>] (__dma_alloc+0x8c/0x3ec) from [<c0036adc>] (dma_alloc_coherent+0x54/0x60)
 [<c0036adc>] (dma_alloc_coherent+0x54/0x60) from [<c0227808>] (ep93xx_open+0x20/0x864)
 [<c0227808>] (ep93xx_open+0x20/0x864) from [<c0283144>] (__dev_open+0xb8/0x108)
 [<c0283144>] (__dev_open+0xb8/0x108) from [<c0280528>] (__dev_change_flags+0x70/0x128)
 [<c0280528>] (__dev_change_flags+0x70/0x128) from [<c0283054>] (dev_change_flags+0x10/0x48)
 [<c0283054>] (dev_change_flags+0x10/0x48) from [<c001a720>] (ip_auto_config+0x190/0xf68)
 [<c001a720>] (ip_auto_config+0x190/0xf68) from [<c00233b0>] (do_one_initcall+0x34/0x18c)
 [<c00233b0>] (do_one_initcall+0x34/0x18c) from [<c0008400>] (kernel_init+0x94/0x134)
 [<c0008400>] (kernel_init+0x94/0x134) from [<c0030858>] (kernel_thread_exit+0x0/0x8)

Since there is no restrictions for DMA on ep93xx, we can fix this by just
removing the GFP_DMA flag from the call.
Signed-off-by: Mika Westerberg <mika.westerberg@iki.fi>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Tested-by: Petr Stetiar <ynezz@true.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>

We can use simply kmalloc() to allocate the buffers. This also simplifies the
code and allows us to perform DMA sync operations more easily.

Memory is allocated with only GFP_KERNEL since there are no DMA allocation
restrictions on this platform.
Signed-off-by: Mika Westerberg <mika.westerberg@iki.fi>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Tested-by: Petr Stetiar <ynezz@true.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>

We shouldn't use NULL for any DMA API functions, unless we are dealing with
ISA or EISA device. So pass correct struct dev pointer to these functions.
Signed-off-by: Mika Westerberg <mika.westerberg@iki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since the driver uses the DMA API, we should pass it valid DMA masks.
Signed-off-by: Mika Westerberg <mika.westerberg@iki.fi>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Tested-by: Petr Stetiar <ynezz@true.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>

Testing of VLAN_FLAG_REORDER_HDR does not belong in vlan_untag
but rather in vlan_do_receive.  Otherwise the vlan header
will not be properly put on the packet in the case of
vlan header accelleration.

As we remove the check from vlan_check_reorder_header
rename it vlan_reorder_header to keep the naming clean.

Fix up the skb->pkt_type early so we don't look at the packet
after adding the vlan tag, which guarantees we don't goof
and look at the wrong field.

Use a simple if statement instead of a complicated switch
statement to decided that we need to increment rx_stats
for a multicast packet.

Hopefully at somepoint we will just declare the case where
VLAN_FLAG_REORDER_HDR is cleared as unsupported and remove
the code.  Until then this keeps it working correctly.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Acked-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Daniel Hellstrom <daniel@gaisler.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix:
/tmp/ccvoZ6h8.s: Assembler messages:
/tmp/ccvoZ6h8.s:284: Warning: register range not in ascending order
/tmp/ccvoZ6h8.s:881: Warning: register range not in ascending order
/tmp/ccvoZ6h8.s:1087: Warning: register range not in ascending order

by ensuring that we have temporary variables placed into specific
registers.  Reorder the code a bit to allow the resulting assembly
to be slightly more optimal.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

We were clearing out the multicast filter whenever the interface was
upped, and not setting the mode bits correctly.  This can cause
problems if there are any multicast addresses already set at this
point, or if ALLMULTI was set.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

Without this the compiler can (and does) optimize register reads away
from within loops, and other such optimizations.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

One of the legit warnings 'make W=3 drivers/ide/ide-cd.c'
generates is:
drivers/ide/ide-cd.c: In function ide_cd_do_request
drivers/ide/ide-cd.c:828:2: warning: conversion to int from \
unsigned int may change the sign of the result
drivers/ide/ide-cd.c:833:2: warning: conversion to int from \
unsigned int may change the sign of the result

nsectors is declared int, should be unsigned int.

blk_rq_sectors() returns unsigned int, and ide_complete_rq
expects unsigned int as well.  Fixes both warnings.
Signed-off-by: Connor Hansen <cmdkhh@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

It uses cpu_relax(), and so needs <asm/processor.h>

Without this patch, I see:

   CC      arch/mn10300/kernel/asm-offsets.s
  In file included from include/linux/time.h:8,
                   from include/linux/timex.h:56,
                   from include/linux/sched.h:57,
                   from arch/mn10300/kernel/asm-offsets.c:7:
  include/linux/seqlock.h: In function 'read_seqbegin':
  include/linux/seqlock.h:91: error: implicit declaration of function 'cpu_relax'

whilst building asb2364_defconfig on MN10300.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The WARN_ON() in start_transaction() was triggered while balancing.

The cause is btrfs_relocate_chunk() started a transaction and
then called iput() on the inode that stores free space cache,
and iput() called btrfs_start_transaction() again.
Reported-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Reviewed-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>