* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx:
  shdma: fix initialization error handling
  ioat3: fix pq completion versus channel deallocation race
  async_tx: build-time toggling of async_{syndrome,xor}_val dma support
  dmaengine: include xor/pq validate in device_has_all_tx_types()
  ioat2,3: report all uncorrectable errors
  ioat3: specify valid address for disabled-Q or disabled-P
  ioat2,3: disable asynchronous error notifications
  ioat3: dca and raid operations are incompatible
  ioat: silence "dca disabled" messages

* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus:
  Staging: octeon-ethernet: Assign proper MAC addresses.
  Staging: Octeon: Use symbolic values for irq numbers.
  MIPS: Octeon: Fix compile error in drivers/staging/octeon/ethernet-mdio.c

In 2.6.23 kernel, commit a32ea1e1
("Fix read/truncate race") fixed a race in the generic code, and as a
side effect, now do_generic_file_read() can ask us to readpage() past
the i_size. This seems to be correctly handled by the block routines
(e.g. block_read_full_page() fills the page with zeroes in case if
somebody is trying to read past the last inode's block).

JFFS2 doesn't handle this; it assumes that it won't be asked to read
pages which don't exist -- and thus that there will be at least _one_
valid 'frag' on the page it's being asked to read. It will fill any
holes with the following memset:

  memset(buf, 0, min(end, frag->ofs + frag->size) - offset);

When the 'closest smaller match' returned by jffs2_lookup_node_frag() is
actually on a previous page and ends before 'offset', that results in:

  memset(buf, 0, <huge unsigned negative>);

Hopefully, in most cases the corruption is fatal, and quickly causing
random oopses, like this:

  root@10.0.0.4:~/ltp-fs-20090531# ./testcases/kernel/fs/ftest/ftest01
  Unable to handle kernel paging request for data at address 0x00000008
  Faulting instruction address: 0xc01cd980
  Oops: Kernel access of bad area, sig: 11 [#1]
  [...]
  NIP [c01cd980] rb_insert_color+0x38/0x184
  LR [c0043978] enqueue_hrtimer+0x88/0xc4
  Call Trace:
  [c6c63b60] [c004f9a8] tick_sched_timer+0xa0/0xe4 (unreliable)
  [c6c63b80] [c0043978] enqueue_hrtimer+0x88/0xc4
  [c6c63b90] [c0043a48] __run_hrtimer+0x94/0xbc
  [c6c63bb0] [c0044628] hrtimer_interrupt+0x140/0x2b8
  [c6c63c10] [c000f8e8] timer_interrupt+0x13c/0x254
  [c6c63c30] [c001352c] ret_from_except+0x0/0x14
  --- Exception: 901 at memset+0x38/0x5c
      LR = jffs2_read_inode_range+0x144/0x17c
  [c6c63cf0] [00000000] (null) (unreliable)

This patch fixes the issue, plus fixes all LTP tests on NAND/UBI with
JFFS2 filesystem that were failing since 2.6.23 (seems like the bug
above also broke the truncation).
Reported-By: NAnton Vorontsov <avorontsov@ru.mvista.com>
Tested-By: NAnton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Cc: stable@kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The fbdev mailing lists at SourceForge have been migrated to a single
mailing list at kernel.org: linux-fbdev@vger.kernel.org.
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Acked-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-kconfig:
  kconfig: Fix make O=<dir> local{mod,yes}config

* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
  sata_fsl: Split hard and soft reset

* git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-2.6-fscache: (31 commits)
  FS-Cache: Provide nop fscache_stat_d() if CONFIG_FSCACHE_STATS=n
  SLOW_WORK: Fix GFS2 to #include <linux/module.h> before using THIS_MODULE
  SLOW_WORK: Fix CIFS to pass THIS_MODULE to slow_work_register_user()
  CacheFiles: Don't log lookup/create failing with ENOBUFS
  CacheFiles: Catch an overly long wait for an old active object
  CacheFiles: Better showing of debugging information in active object problems
  CacheFiles: Mark parent directory locks as I_MUTEX_PARENT to keep lockdep happy
  CacheFiles: Handle truncate unlocking the page we're reading
  CacheFiles: Don't write a full page if there's only a partial page to cache
  FS-Cache: Actually requeue an object when requested
  FS-Cache: Start processing an object's operations on that object's death
  FS-Cache: Make sure FSCACHE_COOKIE_LOOKING_UP cleared on lookup failure
  FS-Cache: Add a retirement stat counter
  FS-Cache: Handle pages pending storage that get evicted under OOM conditions
  FS-Cache: Handle read request vs lookup, creation or other cache failure
  FS-Cache: Don't delete pending pages from the page-store tracking tree
  FS-Cache: Fix lock misorder in fscache_write_op()
  FS-Cache: The object-available state can't rely on the cookie to be available
  FS-Cache: Permit cache retrieval ops to be interrupted in the initial wait phase
  FS-Cache: Use radix tree preload correctly in tracking of pages to be stored
  ...

We can have bzip2 compressed images nowadays.
Signed-off-by: NGertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

kernel unwinding is broken with gcc >= 4.x.  Part of the problem is that
binutils seems very sensitive to where the unwind information is stored.
Signed-off-by: NHelge Deller <deller@gmx.de>
Signed-off-by: NKyle McMartin <kyle@mcmartin.ca>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Allocate MAC addresses using the same method as the bootloader.  This
avoids changing the MAC between bootloader and kernel operation as
well as avoiding duplicates and use of addresses outside of the
assigned range.
Signed-off-by: NDavid Daney <ddaney@caviumnetworks.com>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

In addition to being magic numbers, the irq number passed to free_irq
is incorrect.  We need to use the correct symbolic value instead.
Signed-off-by: NDavid Daney <ddaney@caviumnetworks.com>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NDavid Daney <ddaney@caviumnetworks.com>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

1/ Error handling code following a kzalloc should free the allocated data.
2/ Report an error when no platform data is detected

Both problems fixed by moving the platform data check before the allocation,
and allows a goto to be killed.
Reported-by: NJulia Lawall <julia@diku.dk>
Acked-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Provide nop fscache_stat_d() macro if CONFIG_FSCACHE_STATS=n lest errors like
the following occur:

	fs/fscache/cache.c: In function 'fscache_withdraw_cache':
	fs/fscache/cache.c:386: error: implicit declaration of function 'fscache_stat_d'
	fs/fscache/cache.c:386: error: 'fscache_n_cop_sync_cache' undeclared (first use in this function)
	fs/fscache/cache.c:386: error: (Each undeclared identifier is reported only once
	fs/fscache/cache.c:386: error: for each function it appears in.)
	fs/fscache/cache.c:392: error: 'fscache_n_cop_dissociate_pages' undeclared (first use in this function)
Signed-off-by: NDavid Howells <dhowells@redhat.com>

GFS2 has been altered to pass THIS_MODULE to slow_work_register_user(), but
hasn't been altered to #include <linux/module.h> to provide it, resulting in
the following error:

	fs/gfs2/recovery.c:596: error: 'THIS_MODULE' undeclared here (not in a function)

Add the missing #include.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

As of the patch:

	SLOW_WORK: Wait for outstanding work items belonging to a module to clear

	Wait for outstanding slow work items belonging to a module to clear
	when unregistering that module as a user of the facility.  This
	prevents the put_ref code of a work item from being taken away before
	it returns.

slow_work_register_user() takes a module pointer as an argument.  CIFS must now
pass THIS_MODULE as that argument, lest the following error be observed:

	fs/cifs/cifsfs.c: In function 'init_cifs':
	fs/cifs/cifsfs.c:1040: error: too few arguments to function 'slow_work_register_user'
Signed-off-by: NDavid Howells <dhowells@redhat.com>

When the output directory is something other than the kernel source,
the streamline_config script gets confused. This patch passes in the
source directory to the script so that it can find the proper files.
Reported-by: NPeter Zijlstra <peterz@infradead.org>
Tested-by: NPeter Zijlstra <peterz@infradead.org>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

The completion of a pq operation is notified with a null descriptor
appended to the end of the chain.  This descriptor needs to be visible
to dma clients otherwise the client is precluded from ensuring all
operations are quiesced before freeing channel resources, i.e. due to
descriptor polling it may get the completion notification ahead of the
interrupt delivered by the null descriptor.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

ioat3.2 does not support asynchronous error notifications which makes
the driver experience latencies when non-zero pq validate results are
expected.  Provide a mechanism for turning off async_xor_val and
async_syndrome_val via Kconfig.  This approach is generally useful for
any driver that specifies ASYNC_TX_DISABLE_CHANNEL_SWITCH and would like
to force the async_tx api to fall back to the synchronous path for
certain operations.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

A channel must include these capabilities to satisfy
ASYNC_TX_DISABLE_CHANNEL_SWITCH.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Modify is_ioat_bug() to catch all errors that are uncorrectable, or not
currently handled.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

* 'i2c-pnx-fixes' of git://git.fluff.org/bjdooks/linux:
  i2c: i2c-pnx: Added missing mach/i2c.h and linux/io.h header file includes
  i2c: i2c-pnx: Made buf type unsigned to prevent sign extension
  i2c: i2c-pnx: Limit minimum jiffie timeout to 2

* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2:
  ocfs2: Trivial cleanup of jbd compatibility layer removal
  ocfs2: Refresh documentation
  ocfs2: return f_fsid info in ocfs2_statfs()
  ocfs2: duplicate inline data properly during reflink.
  ocfs2: Move ocfs2_complete_reflink to the right place.
  ocfs2: Return -EINVAL when a device is not ocfs2.

Added missing mach/i2c.h and linux/io.h header file includes
Signed-off-by: NKevin Wells <kevin.wells@nxp.com>
Signed-off-by: NBen Dooks <ben-linux@fluff.org>

Made buf type unsigned to prevent sign extension
Signed-off-by: NKevin Wells <kevin.wells@nxp.com>
Signed-off-by: NBen Dooks <ben-linux@fluff.org>

Limit minimum jiffie timeout to 2 to prevent early timeout on systems
with low tick rates
Signed-off-by: NKevin Wells <kevin.wells@nxp.com>
Signed-off-by: NBen Dooks <ben-linux@fluff.org>

Although disabled, hardware still checks address validity, so duplicate
the known address.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Error interrupts and error completions may cause channel hangs, so
poll the channel status register after a timeout.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

RAID operations cause a system hang on platforms with DCA
(Direct-Cache-Access) enabled.  So turn off RAID capabilities in this
case.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Split sata_fsl_softreset() into hard and soft resets to make
error-handling more efficient & device and PMP detection more
reliable.

Also includes fix for PMP support, driver tested with Sil3726,
Sil4726 & Exar PMP controllers.

[AV: Also fixes resuming from deep sleep on MPC8315 CPUs]
Signed-off-by: NJiang Yutang <b14898@freescale.com>
Signed-off-by: NAnton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

* 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6:
  SUNRPC: Address buffer overrun in rpc_uaddr2sockaddr()
  NFSv4: Fix a cache validation bug which causes getcwd() to return ENOENT

As this struct is exposed to user space and the API was added for this
release it's a bit of a pain for the C++ world and we still have time to
fix it. Rename the fields before we end up with that pain in an actual
release.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Reported-by: Olivier Goffart
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 86cf898e ("intel-iommu: Check for
'DMAR at zero' BIOS error earlier.") was supposed to work by pretending
not to detect an IOMMU if it was actually being reported by the BIOS at
physical address zero.

However, the intel_iommu_init() function is called unconditionally, as
are the corresponding functions for other IOMMU hardware.

So the patch only worked if you have RAM above the 4GiB boundary. It
caused swiotlb to be initialised when no IOMMU was detected during early
boot, and thus the later IOMMU init would refuse to run.

But if you have less RAM than that, swiotlb wouldn't get set up and the
IOMMU _would_ still end up being initialised, even though we never
claimed to detect it.

This patch also sets the dmar_disabled flag when the error is detected
during the initial detection phase -- so that the later call to
intel_iommu_init() will return without doing anything, regardless of
whether swiotlb is used or not.
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Don't log the CacheFiles lookup/create object routined failing with ENOBUFS as
under high memory load or high cache load they can do this quite a lot.  This
error simply means that the requested object cannot be created on disk due to
lack of space, or due to failure of the backing filesystem to find sufficient
resources.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Catch an overly long wait for an old, dying active object when we want to
replace it with a new one.  The probability is that all the slow-work threads
are hogged, and the delete can't get a look in.

What we do instead is:

 (1) if there's nothing in the slow work queue, we sleep until either the dying
     object has finished dying or there is something in the slow work queue
     behind which we can queue our object.

 (2) if there is something in the slow work queue, we return ETIMEDOUT to
     fscache_lookup_object(), which then puts us back on the slow work queue,
     presumably behind the deletion that we're blocked by.  We are then
     deferred for a while until we work our way back through the queue -
     without blocking a slow-work thread unnecessarily.

A backtrace similar to the following may appear in the log without this patch:

	INFO: task kslowd004:5711 blocked for more than 120 seconds.
	"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
	kslowd004     D 0000000000000000     0  5711      2 0x00000080
	 ffff88000340bb80 0000000000000046 ffff88002550d000 0000000000000000
	 ffff88002550d000 0000000000000007 ffff88000340bfd8 ffff88002550d2a8
	 000000000000ddf0 00000000000118c0 00000000000118c0 ffff88002550d2a8
	Call Trace:
	 [<ffffffff81058e21>] ? trace_hardirqs_on+0xd/0xf
	 [<ffffffffa011c4d8>] ? cachefiles_wait_bit+0x0/0xd [cachefiles]
	 [<ffffffffa011c4e1>] cachefiles_wait_bit+0x9/0xd [cachefiles]
	 [<ffffffff81353153>] __wait_on_bit+0x43/0x76
	 [<ffffffff8111ae39>] ? ext3_xattr_get+0x1ec/0x270
	 [<ffffffff813531ef>] out_of_line_wait_on_bit+0x69/0x74
	 [<ffffffffa011c4d8>] ? cachefiles_wait_bit+0x0/0xd [cachefiles]
	 [<ffffffff8104c125>] ? wake_bit_function+0x0/0x2e
	 [<ffffffffa011bc79>] cachefiles_mark_object_active+0x203/0x23b [cachefiles]
	 [<ffffffffa011c209>] cachefiles_walk_to_object+0x558/0x827 [cachefiles]
	 [<ffffffffa011a429>] cachefiles_lookup_object+0xac/0x12a [cachefiles]
	 [<ffffffffa00aa1e9>] fscache_lookup_object+0x1c7/0x214 [fscache]
	 [<ffffffffa00aafc5>] fscache_object_state_machine+0xa5/0x52d [fscache]
	 [<ffffffffa00ab4ac>] fscache_object_slow_work_execute+0x5f/0xa0 [fscache]
	 [<ffffffff81082093>] slow_work_execute+0x18f/0x2d1
	 [<ffffffff8108239a>] slow_work_thread+0x1c5/0x308
	 [<ffffffff8104c0f1>] ? autoremove_wake_function+0x0/0x34
	 [<ffffffff810821d5>] ? slow_work_thread+0x0/0x308
	 [<ffffffff8104be91>] kthread+0x7a/0x82
	 [<ffffffff8100beda>] child_rip+0xa/0x20
	 [<ffffffff8100b87c>] ? restore_args+0x0/0x30
	 [<ffffffff8104be17>] ? kthread+0x0/0x82
	 [<ffffffff8100bed0>] ? child_rip+0x0/0x20
	1 lock held by kslowd004/5711:
	 #0:  (&sb->s_type->i_mutex_key#7/1){+.+.+.}, at: [<ffffffffa011be64>] cachefiles_walk_to_object+0x1b3/0x827 [cachefiles]
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Show more debugging information if cachefiles_mark_object_active() is asked to
activate an active object.

This may happen, for instance, if the netfs tries to register an object with
the same key multiple times.

The code is changed to (a) get the appropriate object lock to protect the
cookie pointer whilst we dereference it, and (b) get and display the cookie key
if available.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Mark parent directory locks as I_MUTEX_PARENT in the callers of
cachefiles_bury_object() so that lockdep doesn't complain when that invokes
vfs_unlink():

=============================================
[ INFO: possible recursive locking detected ]
2.6.32-rc6-cachefs #47
---------------------------------------------
kslowd002/3089 is trying to acquire lock:
 (&sb->s_type->i_mutex_key#7){+.+.+.}, at: [<ffffffff810bbf72>] vfs_unlink+0x8b/0x128

but task is already holding lock:
 (&sb->s_type->i_mutex_key#7){+.+.+.}, at: [<ffffffffa00e4e61>] cachefiles_walk_to_object+0x1b0/0x831 [cachefiles]

other info that might help us debug this:
1 lock held by kslowd002/3089:
 #0:  (&sb->s_type->i_mutex_key#7){+.+.+.}, at: [<ffffffffa00e4e61>] cachefiles_walk_to_object+0x1b0/0x831 [cachefiles]

stack backtrace:
Pid: 3089, comm: kslowd002 Not tainted 2.6.32-rc6-cachefs #47
Call Trace:
 [<ffffffff8105ad7b>] __lock_acquire+0x1649/0x16e3
 [<ffffffff8118170e>] ? inode_has_perm+0x5f/0x61
 [<ffffffff8105ae6c>] lock_acquire+0x57/0x6d
 [<ffffffff810bbf72>] ? vfs_unlink+0x8b/0x128
 [<ffffffff81353ac3>] mutex_lock_nested+0x54/0x292
 [<ffffffff810bbf72>] ? vfs_unlink+0x8b/0x128
 [<ffffffff8118179e>] ? selinux_inode_permission+0x8e/0x90
 [<ffffffff8117e271>] ? security_inode_permission+0x1c/0x1e
 [<ffffffff810bb4fb>] ? inode_permission+0x99/0xa5
 [<ffffffff810bbf72>] vfs_unlink+0x8b/0x128
 [<ffffffff810adb19>] ? kfree+0xed/0xf9
 [<ffffffffa00e3f00>] cachefiles_bury_object+0xb6/0x420 [cachefiles]
 [<ffffffff81058e21>] ? trace_hardirqs_on+0xd/0xf
 [<ffffffffa00e7e24>] ? cachefiles_check_object_xattr+0x233/0x293 [cachefiles]
 [<ffffffffa00e51b0>] cachefiles_walk_to_object+0x4ff/0x831 [cachefiles]
 [<ffffffff81032238>] ? finish_task_switch+0x0/0xb2
 [<ffffffffa00e3429>] cachefiles_lookup_object+0xac/0x12a [cachefiles]
 [<ffffffffa00741e9>] fscache_lookup_object+0x1c7/0x214 [fscache]
 [<ffffffffa0074fc5>] fscache_object_state_machine+0xa5/0x52d [fscache]
 [<ffffffffa00754ac>] fscache_object_slow_work_execute+0x5f/0xa0 [fscache]
 [<ffffffff81082093>] slow_work_execute+0x18f/0x2d1
 [<ffffffff8108239a>] slow_work_thread+0x1c5/0x308
 [<ffffffff8104c0f1>] ? autoremove_wake_function+0x0/0x34
 [<ffffffff810821d5>] ? slow_work_thread+0x0/0x308
 [<ffffffff8104be91>] kthread+0x7a/0x82
 [<ffffffff8100beda>] child_rip+0xa/0x20
 [<ffffffff8100b87c>] ? restore_args+0x0/0x30
 [<ffffffff8104be17>] ? kthread+0x0/0x82
 [<ffffffff8100bed0>] ? child_rip+0x0/0x20
Signed-off-by: NDaivd Howells <dhowells@redhat.com>

Handle truncate unlocking the page we're attempting to read from the backing
device before the read has completed.

This was causing reports like the following to occur:

	Pid: 4765, comm: kslowd Not tainted 2.6.30.1 #1
	Call Trace:
	 [<ffffffffa0331d7a>] ? cachefiles_read_waiter+0xd9/0x147 [cachefiles]
	 [<ffffffff804b74bd>] ? __wait_on_bit+0x60/0x6f
	 [<ffffffff8022bbbb>] ? __wake_up_common+0x3f/0x71
	 [<ffffffff8022cc32>] ? __wake_up+0x30/0x44
	 [<ffffffff8024a41f>] ? __wake_up_bit+0x28/0x2d
	 [<ffffffffa003a793>] ? ext3_truncate+0x4d7/0x8ed [ext3]
	 [<ffffffff80281f90>] ? pagevec_lookup+0x17/0x1f
	 [<ffffffff8028c2ff>] ? unmap_mapping_range+0x59/0x1ff
	 [<ffffffff8022cc32>] ? __wake_up+0x30/0x44
	 [<ffffffff8028e286>] ? vmtruncate+0xc2/0xe2
	 [<ffffffff802b82cf>] ? inode_setattr+0x22/0x10a
	 [<ffffffffa003baa5>] ? ext3_setattr+0x17b/0x1e6 [ext3]
	 [<ffffffff802b853d>] ? notify_change+0x186/0x2c9
	 [<ffffffffa032d9de>] ? cachefiles_attr_changed+0x133/0x1cd [cachefiles]
	 [<ffffffffa032df7f>] ? cachefiles_lookup_object+0xcf/0x12a [cachefiles]
	 [<ffffffffa0318165>] ? fscache_lookup_object+0x110/0x122 [fscache]
	 [<ffffffffa03188c3>] ? fscache_object_slow_work_execute+0x590/0x6bc
	[fscache]
	 [<ffffffff80278f82>] ? slow_work_thread+0x285/0x43a
	 [<ffffffff8024a446>] ? autoremove_wake_function+0x0/0x2e
	 [<ffffffff80278cfd>] ? slow_work_thread+0x0/0x43a
	 [<ffffffff8024a317>] ? kthread+0x54/0x81
	 [<ffffffff8020c93a>] ? child_rip+0xa/0x20
	 [<ffffffff8024a2c3>] ? kthread+0x0/0x81
	 [<ffffffff8020c930>] ? child_rip+0x0/0x20
	CacheFiles: I/O Error: Readpage failed on backing file 200000000000810
	FS-Cache: Cache cachefiles stopped due to I/O error
Reported-by: NChristian Kujau <lists@nerdbynature.de>
Reported-by: NTakashi Iwai <tiwai@suse.de>
Reported-by: NDuc Le Minh <duclm.vn@gmail.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>

cachefiles_write_page() writes a full page to the backing file for the last
page of the netfs file, even if the netfs file's last page is only a partial
page.

This causes the EOF on the backing file to be extended beyond the EOF of the
netfs, and thus the backing file will be truncated by cachefiles_attr_changed()
called from cachefiles_lookup_object().

So we need to limit the write we make to the backing file on that last page
such that it doesn't push the EOF too far.

Also, if a backing file that has a partial page at the end is expanded, we
discard the partial page and refetch it on the basis that we then have a hole
in the file with invalid data, and should the power go out...  A better way to
deal with this could be to record a note that the partial page contains invalid
data until the correct data is written into it.

This isn't a problem for netfs's that discard the whole backing file if the
file size changes (such as NFS).
Signed-off-by: NDavid Howells <dhowells@redhat.com>