If we stopped a bcache device when we were already detaching (or
something like that), bcache_device_unlink() would try to remove a
symlink from sysfs that was already gone because the bcache dev kobject
had already been removed from sysfs.

So keep track of whether we've removed stuff from sysfs.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10

Whoops - bcache's flush/FUA was mostly correct, but flushes get filtered
out unless we say we support them...
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10

There is a missing NULL check after the kzalloc().
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

In the far-too-complicated closure code - closures can have destructors,
for probably dubious reasons; they get run after the closure is no
longer waiting on anything but before dropping the parent ref, intended
just for freeing whatever memory the closure is embedded in.

Trouble is, when remaining goes to 0 and we've got nothing more to run -
we also have to unlock the closure, setting remaining to -1. If there's
a destructor, that unlock isn't doing anything - nobody could be trying
to lock it if we're about to free it - but if the unlock _is needed...
that check for a destructor was racy. Argh.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>
Cc: linux-stable <stable@vger.kernel.org> # >= v3.10

Some of bcache's utility code has made it into the rest of the kernel,
so drop the bcache versions.

Bcache used to have a workaround for allocating from a bio set under
generic_make_request() (if you allocated more than once, the bios you
already allocated would get stuck on current->bio_list when you
submitted, and you'd risk deadlock) - bcache would mask out __GFP_WAIT
when allocating bios under generic_make_request() so that allocation
could fail and it could retry from workqueue. But bio_alloc_bioset() has
a workaround now, so we can drop this hack and the associated error
handling.
Signed-off-by: Kent Overstreet <koverstreet@google.com>

Signed-off-by: Kent Overstreet <kmo@daterainc.com>

This code has rotted and it hasn't been used in ages anyways.
Signed-off-by: Kent Overstreet <kmo@daterainc.com>

Signed-off-by: Kent Overstreet <kmo@daterainc.com>

Journal writes need to be marked FUA, not just REQ_FLUSH. And btree node
writes have... weird ordering requirements.
Signed-off-by: Kent Overstreet <koverstreet@google.com>

Mention udev autoregistration, symlinks.  Write down some sysfs paths.
Signed-off-by: Gabriel de Perthuis <g2p.code@gmail.com>
Signed-off-by: Kent Overstreet <koverstreet@google.com>

Signed-off-by: Gabriel de Perthuis <g2p.code@gmail.com>
Signed-off-by: Kent Overstreet <koverstreet@google.com>

Signed-off-by: Gabriel de Perthuis <g2p.code@gmail.com>

Correct spelling typo in documentation/bcache.txt
Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Kent Overstreet <koverstreet@google.com>

Now that we're tracking dirty data per stripe, we can add two
optimizations for raid5/6:

 * If a stripe is already dirty, force writes to that stripe to
   writeback mode - to help build up full stripes of dirty data

 * When flushing dirty data, preferentially write out full stripes first
   if there are any.
Signed-off-by: Kent Overstreet <koverstreet@google.com>

To make background writeback aware of raid5/6 stripes, we first need to
track the amount of dirty data within each stripe - we do this by
breaking up the existing sectors_dirty into per stripe atomic_ts
Signed-off-by: Kent Overstreet <koverstreet@google.com>

Previously, dirty_data wouldn't get initialized until the first garbage
collection... which was a bit of a problem for background writeback (as
the PD controller keys off of it) and also confusing for users.

This is also prep work for making background writeback aware of raid5/6
stripes.
Signed-off-by: Kent Overstreet <koverstreet@google.com>

The old lazy sorting code was kind of hacky - rewrite in a way that
mathematically makes more sense; the idea is that the size of the sets
of keys in a btree node should increase by a more or less fixed ratio
from smallest to biggest.
Signed-off-by: Kent Overstreet <koverstreet@google.com>

Old gcc doesnt like the struct hack, and it is kind of ugly. So finish
off the work to convert pr_debug() statements to tracepoints, and delete
pkey()/pbtree().
Signed-off-by: Kent Overstreet <koverstreet@google.com>

The tracepoints were reworked to be more sensible, and fixed a null
pointer deref in one of the tracepoints.

Converted some of the pr_debug()s to tracepoints - this is partly a
performance optimization; it used to be that with DEBUG or
CONFIG_DYNAMIC_DEBUG pr_debug() was an empty macro; but at some point it
was changed to an empty inline function.

Some of the pr_debug() statements had rather expensive function calls as
part of the arguments, so this code was getting run unnecessarily even
on non debug kernels - in some fast paths, too.
Signed-off-by: Kent Overstreet <koverstreet@google.com>

The most significant change is that btree reads are now done
synchronously, instead of asynchronously and doing the post read stuff
from a workqueue.

This was originally done because we can't block on IO under
generic_make_request(). But - we already have a mechanism to punt cache
lookups to workqueue if needed, so if we just use that we don't have to
deal with the complexity of doing things asynchronously.

The main benefit is this makes the locking situation saner; we can hold
our write lock on the btree node until we're finished reading it, and we
don't need that btree_node_read_done() flag anymore.

Also, for writes, btree_write() was broken out into btree_node_write()
and btree_leaf_dirty() - the old code with the boolean argument was dumb
and confusing.

The prio_blocked mechanism was improved a bit too, now the only counter
is in struct btree_write, we don't mess with transfering a count from
struct btree anymore.

This required changing garbage collection to block prios at the start
and unblock when it finishes, which is cleaner than what it was doing
anyways (the old code had mostly the same effect, but was doing it in a
convoluted way)

And the btree iter btree_node_read_done() uses was converted to a real
mempool.
Signed-off-by: Kent Overstreet <koverstreet@google.com>

Using a workqueue when we just want a single thread is a bit silly.
Signed-off-by: Kent Overstreet <koverstreet@google.com>

Signed-off-by: Gabriel de Perthuis <g2p.code+bcache@gmail.com>
Signed-off-by: Kent Overstreet <koverstreet@google.com>

An old version of gcc was complaining about using a const int as the
size of a stack allocated array. Which should be fine - but using
ARRAY_SIZE() is better, anyways.

Also, refactor the code to use scnprintf().
Signed-off-by: Kent Overstreet <koverstreet@google.com>

bio_alloc_bioset returns NULL on failure. This fix adds a missing check
for potential NULL pointer dereferencing.
Signed-off-by: Kumar Amit Mehta <gmate.amit@gmail.com>
Signed-off-by: Kent Overstreet <koverstreet@google.com>

Pull ARM SoC fixes from Arnd Bergmann:
 "These are two fixes that came in this week, one for a regression we
  introduced in 3.10 in the GIC interrupt code, and the other one fixes
  a typo in newly introduced code"

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  irqchip: gic: call gic_cpu_init() as well in CPU_STARTING_FROZEN case
  ARM: dts: Correct the base address of pinctrl_3 on Exynos5250

Merge tag 'driver-core-3.10-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core fix from Greg Kroah-Hartman:
 "Here's a single patch for the firmware core that resolves a reported
  oops in the firmware core that people have been hitting."

* tag 'driver-core-3.10-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  firmware loader: fix use-after-free by double abort

Pull USB fixes from Greg Kroah-Hartman:
 "Here are two USB patches for 3.10.

  One updates the Kconfig wording for CONFIG_USB_PHY to make it,
  hopefully, more obvious what this option is (I know you complained
  about this when it hit the tree.) The other is a new device id for a
  driver"

* tag 'usb-3.10-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  USB: serial: ti_usb_3410_5052: new device id for Abbot strip port cable
  usb: phy: Improve Kconfig help for CONFIG_USB_PHY

Pul tty fixes from Greg Kroah-Hartman:
 "Here are two tty core fixes that resolve some regressions that have
  been reported recently.  Both tiny fixes, but needed"

* tag 'tty-3.10-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  tty: Fix transient pty write() EIO
  tty/vt: Return EBUSY if deallocating VT1 and it is busy

Pull SCSI target fixes from Nicholas Bellinger:
 "Included is the recent tcm_qla2xxx residual underrun length fix from
  Roland, along with Joern's iscsi-target patch for session_lock
  breakage within iscsit_stop_time2retain_timer() code.  Both are CC'ed
  to stable.

  The remaining two are specific to recent iscsi-target + iser
  conversion changes.  One drops some left-over debug noise, and Andy's
  patch fixes configfs attribute handling during an explicit network
  portal feature bit disable when iser-target is unsupported."

* git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending:
  iscsi-target: Remove left over v3.10-rc debug printks
  target/iscsi: Fix op=disable + error handling cases in np_store_iser
  tcm_qla2xxx: Fix residual for underrun commands that fail
  target/iscsi: don't corrupt bh_count in iscsit_stop_time2retain_timer()

Pull media fixes from Mauro Carvalho Chehab:
 "Another set of fixes for Kernel 3.10.

  This series contain:
   - two Kbuild fixes for randconfig
   - a buffer overflow when using rtl28xuu with r820t tuner
   - one clk fixup on exynos4-is driver"

* 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media:
  [media] Fix build when drivers are builtin and frontend modules
  [media] s5p makefiles: don't override other selections on obj-[ym]
  [media] exynos4-is: Fix FIMC-IS clocks initialization
  [media] rtl28xxu: fix buffer overflow when probing Rafael Micro r820t tuner

Pull vfs fixes from Al Viro:
 "Several fixes for bugs caught while looking through f_pos (ab)users"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  aout32 coredump compat fix
  splice: don't pass the address of ->f_pos to methods
  mconsole: we'd better initialize pos before passing it to vfs_read()...

dump_seek() does SEEK_CUR, not SEEK_SET; native binfmt_aout
handles it correctly (seeks by PAGE_SIZE - sizeof(struct user),
getting the current position to PAGE_SIZE), compat one seeks
by PAGE_SIZE and ends up at PAGE_SIZE + already written...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Pull x86 fixes from Peter Anvin:
 "This series fixes a couple of build failures, and fixes MTRR cleanup
  and memory setup on very specific memory maps.

  Finally, it fixes triggering backtraces on all CPUs, which was
  inadvertently disabled on x86."

* 'x86/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/efi: Fix dummy variable buffer allocation
  x86: Fix trigger_all_cpu_backtrace() implementation
  x86: Fix section mismatch on load_ucode_ap
  x86: fix build error and kconfig for ia32_emulation and binfmt
  range: Do not add new blank slot with add_range_with_merge
  x86, mtrr: Fix original mtrr range get for mtrr_cleanup

Pull drm radeon fixes from Dave Airlie:
 "One core fix, but mostly radeon fixes for s/r and big endian UVD
  support, and a fix to stop the GPU being reset for no good reason, and
  crashing people's machines."

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  drm/radeon: update lockup tracking when scheduling in empty ring
  drm/prime: Honor requested file flags when exporting a buffer
  drm/radeon: fix UVD on big endian
  drm/radeon: fix write back suspend regression with uvd v2
  drm/radeon: do not try to uselessly update virtual memory pagetable

Pull ACPI fixes from Rafael Wysocki:

 - Fix for a regression causing a failure to turn on some devices on
   some systems during initialization introduced by a recent revert of
   an ACPI PM change that broke something else.  Fortunately, we know
   exactly what devices are affected, so we can add a fix just for them
   leaving everyone else alone.

 - ACPI power resources initialization fix preventing a NULL pointer
   from being dereferenced in the acpi_add_power_resource() error code
   path.

 - ACPI dock station driver fix that adds missing locking to
   write_undock().

 - ACPI resources allocation fix changing the scope of an old workaround
   so that it doesn't affect systems that aren't actually buggy.  This
   was reported a couple of days ago to fix DMA problems on some new
   platforms so we need it in -stable.  From Mika Westerberg.

* tag 'acpi-3.10-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI / LPSS: Power up LPSS devices during enumeration
  ACPI / PM: Fix error code path for power resources initialization
  ACPI / dock: Take ACPI scan lock in write_undock()
  ACPI / resources: call acpi_get_override_irq() only for legacy IRQ resources

Pull KVM fixes from Paolo Bonzini:
 "Three one-line fixes for my first pull request; one for x86 host, one
  for x86 guest, one for PPC"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  x86: kvmclock: zero initialize pvclock shared memory area
  kvm/ppc/booke: Delay kvmppc_lazy_ee_enable
  KVM: x86: remove vcpu's CPL check in host-invoked XCR set

Pull crypto fix from Herbert Xu:
 "This fixes an unaligned crash in XTS mode when using aseni_intel"

* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: aesni_intel - fix accessing of unaligned memory

Pull Ceph fix from Sage Weil:
 "This fixes a problem preventing the kernel and userland librbd
  libraries from sharing data with the new format 2 images"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  rbd: use the correct length for format 2 object names

 * Don't leak random kernel memory to EFI variable NVRAM when attempting
   to initiate garbage collection. Also, free the kernel memory when
   we're done with it instead of leaking - Ben Hutchings
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>