Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>
Signed-Off-By: NKay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NPierre Ossman <drzeus@drzeus.cx>

fine-tune the HT sched-domains parameters as well.

On a HT capable box, this increases lat_ctx performance from 23.87
usecs to 1.49 usecs:

 # before

 $ ./lat_ctx -s 0 2

   "size=0k ovr=1.89
    2 23.87

 # after

 $ ./lat_ctx -s 0 2

   "size=0k ovr=1.84
     2 1.49
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Tune SD_MC_INIT the same way as SD_CPU_INIT:
unset SD_BALANCE_NEWIDLE, and set SD_WAKE_BALANCE.

This improves vmark by 5%:

vmark         132102 125968 125497 messages/sec    avg 127855.66    .984
vmark         139404 131719 131272 messages/sec    avg 134131.66   1.033
Signed-off-by: NMike Galbraith <efault@gmx.de>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

 # *DOCUMENTATION*

__scm_destroy() walks the list of file descriptors in the scm_fp_list
pointed to by the scm_cookie argument.

Those, in turn, can close sockets and invoke __scm_destroy() again.

There is nothing which limits how deeply this can occur.

The idea for how to fix this is from Linus.  Basically, we do all of
the fput()s at the top level by collecting all of the scm_fp_list
objects hit by an fput().  Inside of the initial __scm_destroy() we
keep running the list until it is empty.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix the hrtimer_add_expires_ns() function.  It should take a 'u64 ns' argument,
but rather takes an 'unsigned long ns' argument - which might only be 32-bits.

On FRV, this results in the kernel locking up because hrtimer_forward() passes
the result of a 64-bit multiplication to this function, for which the compiler
discards the top 32-bits - something that didn't happen when ktime_add_ns() was
called directly.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This adds three helpers:

fat_make_attrs() - makes FAT attributes from inode.
fat_make_mode()  - makes mode_t from FAT attributes.
fat_save_attrs() - saves FAT attributes to inode.

Then this replaces: MSDOS_MKMODE() by fat_make_mode(), fat_attr() by
fat_make_attrs(), ->i_attrs = attr & ATTR_UNUSED by fat_save_attrs().
And for root inode, those is used with ATTR_DIR instead of bogus
ATTR_NONE.
Signed-off-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This splits __KERNEL__ stuff in include/msdos_fs.h into fs/fat/fat.h.
Signed-off-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

__scm_destroy() walks the list of file descriptors in the scm_fp_list
pointed to by the scm_cookie argument.

Those, in turn, can close sockets and invoke __scm_destroy() again.

There is nothing which limits how deeply this can occur.

The idea for how to fix this is from Linus.  Basically, we do all of
the fput()s at the top level by collecting all of the scm_fp_list
objects hit by an fput().  Inside of the initial __scm_destroy() we
keep running the list until it is empty.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch (as1158b) adds round_jiffies_up() and friends.  These
routines work like the analogous round_jiffies() functions, except
that they will never round down.

The new routines will be useful for timeouts where we don't care
exactly when the timer expires, provided it doesn't expire too soon.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

Define __BIOVEC_PHYS_MERGEABLE as the default implementation of
BIOVEC_PHYS_MERGEABLE, so that its available for reuse within an
arch-specific definition of BIOVEC_PHYS_MERGEABLE.
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

Impact: improve wakeup affinity on NUMA systems, tweak SMP systems

Given the fixes+tweaks to the wakeup-buddy code, re-tweak the domain
balancing defaults on NUMA and SMP systems.

Turn on SD_WAKE_AFFINE which was off on x86 NUMA - there's no reason
why we would not want to have wakeup affinity across nodes as well.
(we already do this in the standard NUMA template.)

lat_ctx on a NUMA box is particularly happy about this change:

before:

 |   phoenix:~/l> ./lat_ctx -s 0 2
 |   "size=0k ovr=2.60
 |   2 5.70

after:

 |   phoenix:~/l> ./lat_ctx -s 0 2
 |   "size=0k ovr=2.65
 |   2 2.07

a 2.75x speedup.

pipe-test is similarly happy about it too:

 |  phoenix:~/sched-tests> ./pipe-test
 |   18.26 usecs/loop.
 |   14.70 usecs/loop.
 |   14.38 usecs/loop.
 |   10.55 usecs/loop.              # +WAKE_AFFINE on domain0+domain1
 |   8.63 usecs/loop.
 |   8.59 usecs/loop.
 |   9.03 usecs/loop.
 |   8.94 usecs/loop.
 |   8.96 usecs/loop.
 |   8.63 usecs/loop.

Also:

 - disable SD_BALANCE_NEWIDLE on NUMA and SMP domains (keep it for siblings)
 - enable SD_WAKE_BALANCE on SMP domains

Sysbench+postgresql improves all around the board, quite significantly:

           .28-rc3-11474e2c  .28-rc3-11474e2c-tune
-------------------------------------------------
    1:             571              688    +17.08%
    2:            1236             1206    -2.55%
    4:            2381             2642    +9.89%
    8:            4958             5164    +3.99%
   16:            9580             9574    -0.07%
   32:            7128             8118    +12.20%
   64:            7342             8266    +11.18%
  128:            7342             8064    +8.95%
  256:            7519             7884    +4.62%
  512:            7350             7731    +4.93%
-------------------------------------------------
  SUM:           55412            59341    +6.62%

So it's a win both for the runup portion, the peak area and the tail.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

For "unlock" cycles to 16bit devices in 8bit compatibility mode we need
to use the byte addresses 0xaaa and 0x555. These effectively match
the word address 0x555 and 0x2aa, except the latter has its low bit set.

Most chips don't care about the value of the 'A-1' pin in x8 mode,
but some -- like the ST M29W320D -- do. So we need to be careful to
set it where appropriate.

cfi_send_gen_cmd is only ever passed addresses where the low byte
is 0x00, 0x55 or 0xaa. Of those, only addresses ending 0xaa are
affected by this patch, by masking in the extra low bit when the device
is known to be in compatibility mode.

[dwmw2: Do it only when (cmd_ofs & 0xff) == 0xaa]
v4: Fix  stupid typo in cfi_build_cmd_addr that failed to compile
    I'm writing this patch way to late at night.
v3: Bring all of the work back into cfi_build_cmd_addr
    including calling of map_bankwidth(map) and cfi_interleave(cfi)
    So every caller doesn't need to.
v2: Only modified the address if we our device_type is larger than our
    bus width.

Cc: stable@kernel.org
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>

The changes to deliver hardware accelerated VLAN packets to packet
sockets (commit bc1d0411) caused a warning for non-NAPI drivers.
The __vlan_hwaccel_rx() function is called directly from the drivers
RX function, for non-NAPI drivers that means its still in RX IRQ
context:

[   27.779463] ------------[ cut here ]------------
[   27.779509] WARNING: at kernel/softirq.c:136 local_bh_enable+0x37/0x81()
...
[   27.782520]  [<c0264755>] netif_nit_deliver+0x5b/0x75
[   27.782590]  [<c02bba83>] __vlan_hwaccel_rx+0x79/0x162
[   27.782664]  [<f8851c1d>] atl1_intr+0x9a9/0xa7c [atl1]
[   27.782738]  [<c0155b17>] handle_IRQ_event+0x23/0x51
[   27.782808]  [<c015692e>] handle_edge_irq+0xc2/0x102
[   27.782878]  [<c0105fd5>] do_IRQ+0x4d/0x64

Split hardware accelerated VLAN reception into two parts to fix this:

- __vlan_hwaccel_rx just stores the VLAN TCI and performs the VLAN
  device lookup, then calls netif_receive_skb()/netif_rx()

- vlan_hwaccel_do_receive(), which is invoked by netif_receive_skb()
  in softirq context, performs the real reception and delivery to
  packet sockets.
Reported-and-tested-by: NRamon Casellas <ramon.casellas@cttc.es>
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

libata always uses PIO for ATAPI commands when the number of bytes to
transfer isn't multiple of 16 but quantum DAT72 chokes on odd bytes
PIO transfers.  Implement a horkage to skip the mod16 check and apply
it to the quantum device.

This is reported by John Clark in the following thread.

  http://thread.gmane.org/gmane.linux.ide/34748Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: John Clark <clarkjc@runbox.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Was missing from the initial patch.
Acked-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NHarvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Impact: cleanup

clean up ifdefs: change #ifdef CONFIG_X86_32/64 to
CONFIG_HAVE_ATOMIC_IOMAP.

flip around the #ifdef sections to clean up the structure.
Signed-off-by: NKeith Packard <keithp@keithp.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

s/user/used/
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Impact: add new generic io_map_*() APIs

Graphics devices have large PCI apertures which would consume a significant
fraction of a 32-bit address space if mapped during driver initialization.
Using ioremap at runtime is impractical as it is too slow.

This new set of interfaces uses atomic mappings on 32-bit processors and a
large static mapping on 64-bit processors to provide reasonable 32-bit
performance and optimal 64-bit performance.

The current implementation sits atop the io_map_atomic fixmap-based
mechanism for 32-bit processors.

This includes some editorial suggestions from Randy Dunlap for
Documentation/io-mapping.txt
Signed-off-by: NKeith Packard <keithp@keithp.com>
Signed-off-by: NEric Anholt <eric@anholt.net>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Remove excess kernel-doc function parameters from networking header
& driver files:

Warning(include/net/sock.h:946): Excess function parameter or struct member 'sk' description in 'sk_filter_release'
Warning(include/linux/netdevice.h:1545): Excess function parameter or struct member 'cpu' description in 'netif_tx_lock'
Warning(drivers/net/wan/z85230.c:712): Excess function parameter or struct member 'regs' description in 'z8530_interrupt'
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

libata currently imposes a UDMA5 max transfer rate and 200 sector max
transfer size for SATA devices that sit behind a pata-sata bridge. Lots
of devices have known good bridges that don't need this limit applied.
The MTRON SSD disks are such devices. Transfer rates are increased by
20-30% with the restriction removed.

So add a "blacklist" entry for the MTRON devices, with a flag indicating
that the bridge is known good.
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

The init_phy() function attaches to the PHY, then configures the
SerDes<->TBI link (in SGMII mode).  The TBI is on the MDIO bus with the PHY
(sort of) and is accessed via the gianfar's MDIO registers, using the
functions gfar_local_mdio_read/write(), which don't do any locking.

The previously attached PHY will start a work-queue on a timer, and
probably an irq handler as well, which will talk to the PHY and thus use
the MDIO bus.  This uses phy_read/write(), which have locking, but not
against the gfar_local_mdio versions.

The result is that PHY code will try to use the MDIO bus at the same time
as the SerDes setup code, corrupting the transfers.

Setting up the SerDes before attaching to the PHY will insure that there is
no race between the SerDes code and *our* PHY, but doesn't fix everything.
Typically the PHYs for all gianfar devices are on the same MDIO bus, which
is associated with the first gianfar device.  This means that the first
gianfar's SerDes code could corrupt the MDIO transfers for a different
gianfar's PHY.

The lock used by phy_read/write() is contained in the mii_bus structure,
which is pointed to by the PHY.  This is difficult to access from the
gianfar drivers, as there is no link between a gianfar device and the
mii_bus which shares the same MDIO registers.  As far as the device layer
and drivers are concerned they are two unrelated devices (which happen to
share registers).

Generally all gianfar devices' PHYs will be on the bus associated with the
first gianfar.  But this might not be the case, so simply locking the
gianfar's PHY's mii bus might not lock the mii bus that the SerDes setup
code is going to use.

We solve this by having the code that creates the gianfar platform device
look in the device tree for an mdio device that shares the gianfar's
registers.  If one is found the ID of its platform device is saved in the
gianfar's platform data.

A new function in the gianfar mii code, gfar_get_miibus(), can use the bus
ID to search through the platform devices for a gianfar_mdio device with
the right ID.  The platform device's driver data is the mii_bus structure,
which the SerDes setup code can use to lock the current bus.
Signed-off-by: NTrent Piepho <tpiepho@freescale.com>
CC: Andy Fleming <afleming@freescale.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

Fix compile error below:

     LD      drivers/spi/built-in.o
     CC [M]  drivers/spi/spi_gpio.o
   In file included from drivers/spi/spi_gpio.c:26:
   include/linux/spi/spi_bitbang.h:23: error: field `work' has incomplete type
   make[2]: *** [drivers/spi/spi_gpio.o] Error 1
   make[1]: *** [drivers/spi] Error 2
   make: *** [drivers] Error 2
Signed-off-by: NFernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Junjiro R.  Okajima reported a problem where knfsd crashes if you are
using it to export shmemfs objects and run strict overcommit.  In this
situation the current->mm based modifier to the overcommit goes through a
NULL pointer.

We could simply check for NULL and skip the modifier but we've caught
other real bugs in the past from mm being NULL here - cases where we did
need a valid mm set up (eg the exec bug about a year ago).

To preserve the checks and get the logic we want shuffle the checking
around and add a new helper to the vm_ security wrappers

Also fix a current->mm reference in nommu that should use the passed mm

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix build]
Reported-by: NJunjiro R. Okajima <hooanon05@yahoo.co.jp>
Acked-by: NJames Morris <jmorris@namei.org>
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Put the kernel-doc for might_sleep() _immediately_ before the macro
(no intervening lines).  Otherwise kernel-doc complains like so:

Warning(linux-2.6.27-rc3-git2//include/linux/kernel.h:129): No description found for parameter 'file'
Warning(linux-2.6.27-rc3-git2//include/linux/kernel.h:129): No description found for parameter 'line'

because kernel-doc is looking at the wrong function prototype (i.e.,
__might_sleep).  [Yes, I have a todo note to myself to check/warn for that
inconsistency in scripts/kernel-doc.]
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Cc: <Uwe.Kleine-Koenig@digi.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Nothing uses prepare_write or commit_write. Remove them from the tree
completely.

[akpm@linux-foundation.org: schedule simple_prepare_write() for unexporting]
Signed-off-by: NNick Piggin <npiggin@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

- remove 'private' field from struct subsys
- remove cgroup_init_smp()
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Acked-by: NPaul Menage <menage@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Don't duplicate the implementation of thaw_process().

[akpm@linux-foundation.org: make __thaw_process() static]
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Acked-by: NMatt Helsley <matthltc@us.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

By default, non-privileged tasks can only mlock() a small amount of
memory to avoid a DoS attack by ordinary users.  The Linux kernel
defaulted to 32k (on a 4k page size system) to accommodate the needs of
gpg.

However, newer gpg2 needs 64k in various circumstances and otherwise
fails miserably, see bnc#329675.

Change the default to 64k, and make it more agnostic to PAGE_SIZE.
Signed-off-by: NKurt Garloff <garloff@suse.de>
Signed-off-by: NNick Piggin <npiggin@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add rodata equivalents for assembly use, and fix the section attributes
used by __REFCONST.
Signed-off-by: NJan Beulich <jbeulich@novell.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

struct hid_device_id contains hidden padding which is bad for cross
compiling.  Make the padding explicit and consistent across
architectures.
Signed-off-by: NAndreas Schwab <schwab@suse.de>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Reserve some space so we can add more data.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

Every call of kvm_set_irq() should offer an irq_source_id, which is
allocated by kvm_request_irq_source_id(). Based on irq_source_id, we
identify the irq source and implement logical OR for shared level
interrupts.

The allocated irq_source_id can be freed by kvm_free_irq_source_id().

Currently, we support at most sizeof(unsigned long) different irq sources.

[Amit: - rebase to kvm.git HEAD
       - move definition of KVM_USERSPACE_IRQ_SOURCE_ID to common file
       - move kvm_request_irq_source_id to the update_irq ioctl]

[Xiantao: - Add kvm/ia64 stuff and make it work for kvm/ia64 guests]
Signed-off-by: NSheng Yang <sheng@linux.intel.com>
Signed-off-by: NAmit Shah <amit.shah@redhat.com>
Signed-off-by: NXiantao Zhang <xiantao.zhang@intel.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>

Usbhid structure is allocated on start invoked only from probe
of some driver. When there is no driver, the structure is null
and causes null-dereference oopses.

Fix it by allocating the structure on probe and disconnect of
the device itself. Also make sure we won't race between start
and resume or stop and suspend respectively.

References: http://bugzilla.kernel.org/show_bug.cgi?id=11827Signed-off-by: NJiri Slaby <jirislaby@gmail.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Andreas Schwab <schwab@suse.de>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

This fixes a potential error packet loop.
Signed-off-by: NRemi Denis-Courmont <remi.denis-courmont@nokia.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Based on input from Andi Kleen:
share the platform detection code with ioat_dma and disable the channel in
dma engine only for specific platforms.
Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

libata currently has a pretty dumb ATA_MAX_QUEUE loop for finding
a free tag to use. Instead of fixing that up, convert libata to
using block layer tagging - gets rid of code in libata, and is also
much faster.
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We're getting a lot of storage drivers blamed for interrupt misrouting
issues.  This patch provides a standard way of reporting the problem
... and, if possible, correcting it.
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>

Add support for the OxSemi 'Tornado' devices.

Reformatted and reworked a bit by Alan Cox
Signed-off-by: NLee Howard <lee.howard@mainpine.com>
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

page_cgroup_init() is called from mem_cgroup_init(). But at this
point, we cannot call alloc_bootmem().
(and this caused panic at boot.)

This patch moves page_cgroup_init() to init/main.c.

Time table is following:
==
  parse_args(). # we can trust mem_cgroup_subsys.disabled bit after this.
  ....
  cgroup_init_early()  # "early" init of cgroup.
  ....
  setup_arch()         # memmap is allocated.
  ...
  page_cgroup_init();
  mem_init();   # we cannot call alloc_bootmem after this.
  ....
  cgroup_init() # mem_cgroup is initialized.
==

Before page_cgroup_init(), mem_map must be initialized. So,
I added page_cgroup_init() to init/main.c directly.

(*) maybe this is not very clean but
    - cgroup_init_early() is too early
    - in cgroup_init(), we have to use vmalloc instead of alloc_bootmem().
    use of vmalloc area in x86-32 is important and we should avoid very large
    vmalloc() in x86-32. So, we want to use alloc_bootmem() and added page_cgroup_init()
    directly to init/main.c

[akpm@linux-foundation.org: remove unneeded/bad mem_cgroup_subsys declaration]
[akpm@linux-foundation.org: fix build]
Acked-by: NBalbir Singh <balbir@linux.vnet.ibm.com>
Tested-by: NBalbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When a checkpointing IO fails, current JBD code doesn't check the error
and continue journaling.  This means latest metadata can be lost from both
the journal and filesystem.

This patch leaves the failed metadata blocks in the journal space and
aborts journaling in the case of log_do_checkpoint().  To achieve this, we
need to do:

1. don't remove the failed buffer from the checkpoint list where in
   the case of __try_to_free_cp_buf() because it may be released or
   overwritten by a later transaction
2. log_do_checkpoint() is the last chance, remove the failed buffer
   from the checkpoint list and abort the journal
3. when checkpointing fails, don't update the journal super block to
   prevent the journaled contents from being cleaned.  For safety,
   don't update j_tail and j_tail_sequence either
4. when checkpointing fails, notify this error to the ext3 layer so
   that ext3 don't clear the needs_recovery flag, otherwise the
   journaled contents are ignored and cleaned in the recovery phase
5. if the recovery fails, keep the needs_recovery flag
6. prevent cleanup_journal_tail() from being called between
   __journal_drop_transaction() and journal_abort() (a race issue
   between journal_flush() and __log_wait_for_space()
Signed-off-by: NHidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Acked-by: NJan Kara <jack@suse.cz>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>