btrfs_search_slot sometimes needs write locks on high levels of
the tree.  It remembers the highest level that needs a write lock
and will use that for all future searches through the tree in a given
call.

But, very often we'll just cow the top level or the level below and we
won't really need write locks on the root again after that.  This patch
changes things to adjust the write lock requirement as it unlocks
levels.
Signed-off-by: Chris Mason <chris.mason@oracle.com>

lock_extent_buffer_for_io needs to loop around and make sure the
writeback bits are not set.
Signed-off-by: Chris Mason <chris.mason@oracle.com>

This cuts down on the CPU time used by map_private_extent_buffer
Signed-off-by: Chris Mason <chris.mason@oracle.com>

This patch simplifies how we track our extent buffers.  Previously we could exit
writepages with only having written half of an extent buffer, which meant we had
to track the state of the pages and the state of the extent buffers differently.
Now we only read in entire extent buffers and write out entire extent buffers,
this allows us to simply set bits in our bflags to indicate the state of the eb
and we no longer have to do things like track uptodate with our iotree.  Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

Because an eb can have multiple pages we need to make sure that all pages within
the eb are markes as accessed, since releasepage can be called against any page
in the eb.  This will keep us from possibly evicting hot eb's when we're doing
larger than pagesize eb's.  Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>

Because btrfs cow's we can end up with extent buffers that are no longer
necessary just sitting around in memory.  So instead of evicting these pages, we
could end up evicting things we actually care about.  Thus we have
free_extent_buffer_stale for use when we are freeing tree blocks.  This will
make it so that the ref for the eb being in the radix tree is dropped as soon as
possible and then is freed when the refcount hits 0 instead of waiting to be
released by releasepage.  Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>

We can run into a problem where we find an eb for our existing page already on
the radix tree but it has a ref count of 0.  It hasn't yet been removed by RCU
yet so this can cause issues where we will use the EB after free.  So do
atomic_inc_not_zero on the exists->refs and if it is zero just do
synchronize_rcu() and try again.  We won't have to worry about new allocators
coming in since they will block on the page lock at this point.  Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>

We spend a lot of time looking up extent buffers from pages when we could just
store the pointer to the eb the page is associated with in page->private.  This
patch does just that, and it makes things a little simpler and reduces a bit of
CPU overhead involved with doing metadata IO.  Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>

A few years ago the btrfs code to support blocks lager than
the page size was disabled to fix a few corner cases in the
page cache handling.  This fixes the code to properly support
large metadata blocks again.

Since current kernels will crash early and often with larger
metadata blocks, this adds an incompat bit so that older kernels
can't mount it.

This also does away with different blocksizes for nodes and leaves.
You get a single block size for all tree blocks.
Signed-off-by: Chris Mason <chris.mason@oracle.com>

We have been passing nothing but (u64)-1 to find_free_extent for search_end in
all of the callers, so it's completely useless, and we've always been passing 0
in as search_start, so just remove them as function arguments and move
search_start into find_free_extent.  Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>

This is a relic from before we had the disk space cache and it was to make
bootup times when you had btrfs as root not be so damned slow.  Now that we have
the disk space cache this isn't a problem anymore and really having this code
casues uneeded fragmentation and complexity, so just remove it.  Thanks,
Signed-off-by: Josef Bacik <josef@redhat.com>

Commit 28d82dc1 ("epoll: limit paths") that I did to limit the
number of possible wakeup paths in epoll is causing a few applications
to longer work (dovecot for one).

The original patch is really about limiting the amount of epoll nesting
(since epoll fds can be attached to other fds). Thus, we probably can
allow an unlimited number of paths of depth 1. My current patch limits
it at 1000. And enforce the limits on paths that have a greater depth.

This is captured in: https://bugzilla.redhat.com/show_bug.cgi?id=681578Signed-off-by: Jason Baron <jbaron@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull networking changes from David Miller:
 "1) icmp6_dst_alloc() returns NULL instead of ERR_PTR() leading to
     crashes, particularly during shutdown.  Reported by Dave Jones and
     fixed by Eric Dumazet.

  2) hyperv and wimax/i2400m return NETDEV_TX_BUSY when they have
     already freed the SKB, which causes crashes as to the caller this
     means requeue the packet.  Fixes from Eric Dumazet.

  3) usbnet driver doesn't allocate the right amount of headroom on
     fresh RX SKBs, fix from Eric Dumazet.

  4) Fix regression in ip6_mc_find_dev_rcu(), as an RCU lookup it
     abolutely should not take a reference to 'dev', this leads to
     leaks.  Fix from RonQing Li.

  5) Fix netfilter ctnetlink race between delete and timeout expiration.
     From Pablo Neira Ayuso.

  6) Revert SFQ change which causes regressions, specifically queueing
     to tail can lead to unavoidable flow starvation.  From Eric
     Dumazet.

  7) Fix a memory leak and a crash on corrupt firmware files in bnx2x,
     from Michal Schmidt."

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  netfilter: ctnetlink: fix race between delete and timeout expiration
  ipv6: Don't dev_hold(dev) in ip6_mc_find_dev_rcu.
  wimax/i2400m: fix erroneous NETDEV_TX_BUSY use
  net/hyperv: fix erroneous NETDEV_TX_BUSY use
  net/usbnet: reserve headroom on rx skbs
  bnx2x: fix memory leak in bnx2x_init_firmware()
  bnx2x: fix a crash on corrupt firmware file
  sch_sfq: revert dont put new flow at the end of flows
  ipv6: fix icmp6_dst_alloc()

Pull perf fixes from Ingo Molnar.

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf tools, x86: Build perf on older user-space as well
  perf tools: Use scnprintf where applicable
  perf tools: Incorrect use of snprintf results in SEGV

Kerin Millar reported hardlockups while running `conntrackd -c'
in a busy firewall. That system (with several processors) was
acting as backup in a primary-backup setup.

After several tries, I found a race condition between the deletion
operation of ctnetlink and timeout expiration. This patch fixes
this problem.
Tested-by: Kerin Millar <kerframil@gmail.com>
Reported-by: Kerin Millar <kerframil@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

ip6_mc_find_dev_rcu() is called with rcu_read_lock(), so don't
need to dev_hold().
With dev_hold(), not corresponding dev_put(), will lead to leak.

[ bug introduced in 96b52e61 (ipv6: mcast: RCU conversions) ]
Signed-off-by: RongQing.Li <roy.qing.li@gmail.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge some more email patches from Andrew Morton:
 "A couple of nilfs fixes"

* emailed from Andrew Morton <akpm@linux-foundation.org>:
  nilfs2: fix NULL pointer dereference in nilfs_load_super_block()
  nilfs2: clamp ns_r_segments_percentage to [1, 99]

According to the report from Slicky Devil, nilfs caused kernel oops at
nilfs_load_super_block function during mount after he shrank the
partition without resizing the filesystem:

 BUG: unable to handle kernel NULL pointer dereference at 00000048
 IP: [<d0d7a08e>] nilfs_load_super_block+0x17e/0x280 [nilfs2]
 *pde = 00000000
 Oops: 0000 [#1] PREEMPT SMP
 ...
 Call Trace:
  [<d0d7a87b>] init_nilfs+0x4b/0x2e0 [nilfs2]
  [<d0d6f707>] nilfs_mount+0x447/0x5b0 [nilfs2]
  [<c0226636>] mount_fs+0x36/0x180
  [<c023d961>] vfs_kern_mount+0x51/0xa0
  [<c023ddae>] do_kern_mount+0x3e/0xe0
  [<c023f189>] do_mount+0x169/0x700
  [<c023fa9b>] sys_mount+0x6b/0xa0
  [<c04abd1f>] sysenter_do_call+0x12/0x28
 Code: 53 18 8b 43 20 89 4b 18 8b 4b 24 89 53 1c 89 43 24 89 4b 20 8b 43
 20 c7 43 2c 00 00 00 00 23 75 e8 8b 50 68 89 53 28 8b 54 b3 20 <8b> 72
 48 8b 7a 4c 8b 55 08 89 b3 84 00 00 00 89 bb 88 00 00 00
 EIP: [<d0d7a08e>] nilfs_load_super_block+0x17e/0x280 [nilfs2] SS:ESP 0068:ca9bbdcc
 CR2: 0000000000000048

This turned out due to a defect in an error path which runs if the
calculated location of the secondary super block was invalid.

This patch fixes it and eliminates the reported oops.
Reported-by: Slicky Devil <slicky.dvl@gmail.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Tested-by: Slicky Devil <slicky.dvl@gmail.com>
Cc: <stable@vger.kernel.org>	[2.6.30+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ns_r_segments_percentage is read from the disk.  Bogus or malicious
value could cause integer overflow and malfunction due to meaningless
disk usage calculation.  This patch reports error when mounting such
bogus volumes.
Signed-off-by: Haogang Chen <haogangchen@gmail.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull maintainer update from James Morris:
 "Please pull this patch which adds Serge as maintainer of the
  capabilities code, as discussed on lwn and the lsm list.

  New capabilities must be signed off by the maintainer, and new uses of
  any capabilities should at be cc'd to the maintainer."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  MAINTAINERS: Add Serge as maintainer of capabilities

Pull c6x bugfix from Mark Salter:
 "Remove dead code from entry.S which causes a build failure when using
  a newer assembler (v2.22 complains about it, v2.20 ignores it)."

* tag 'for-linus' of git://linux-c6x.org/git/projects/linux-c6x-upstreaming:
  C6X: remove dead code from entry.S

When writing files to afs I sometimes hit a BUG:

kernel BUG at fs/afs/rxrpc.c:179!

With a backtrace of:

	afs_free_call
	afs_make_call
	afs_fs_store_data
	afs_vnode_store_data
	afs_write_back_from_locked_page
	afs_writepages_region
	afs_writepages

The cause is:

	ASSERT(skb_queue_empty(&call->rx_queue));

Looking at a tcpdump of the session the abort happens because we
are exceeding our disk quota:

	rx abort fs reply store-data error diskquota exceeded (32)

So the abort error is valid. We hit the BUG because we haven't
freed all the resources for the call.

By freeing any skbs in call->rx_queue before calling afs_free_call
we avoid hitting leaking memory and avoid hitting the BUG.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

A read of a large file on an afs mount failed:

# cat junk.file > /dev/null
cat: junk.file: Bad message

Looking at the trace, call->offset wrapped since it is only an
unsigned short. In afs_extract_data:

        _enter("{%u},{%zu},%d,,%zu", call->offset, len, last, count);
...

        if (call->offset < count) {
                if (last) {
                        _leave(" = -EBADMSG [%d < %zu]", call->offset, count);
                        return -EBADMSG;
                }

Which matches the trace:

[cat   ] ==> afs_extract_data({65132},{524},1,,65536)
[cat   ] <== afs_extract_data() = -EBADMSG [0 < 65536]

call->offset went from 65132 to 0. Fix this by making call->offset an
unsigned int.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The ENDPROC() on sys_fadvise64_c6x() in arch/c6x/kernel/entry.S is
outside of the conditional block with the matching ENTRY() macro. This
leads a newer (v2.22 vs. v2.20) assembler to complain:

  /tmp/ccGZBaPT.s: Assembler messages:
  /tmp/ccGZBaPT.s: Error: .size expression for sys_fadvise64_c6x does not evaluate to a constant

The conditional block became dead code when c6x switched to generic
unistd.h and should be removed along with the offending ENDPROC().
Signed-off-by: Mark Salter <msalter@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>

A driver start_xmit() method cannot free skb and return NETDEV_TX_BUSY,
since caller is going to reuse freed skb.

In fact netif_tx_stop_queue() / netif_stop_queue() is needed before
returning NETDEV_TX_BUSY or you can trigger a ksoftirqd fatal loop.

In case of memory allocation error, only safe way is to drop the packet
and return NETDEV_TX_OK

Also increments tx_dropped counter
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

A driver start_xmit() method cannot free skb and return NETDEV_TX_BUSY,
since caller is going to reuse freed skb.

This is mostly a revert of commit bf769375 (staging: hv: fix the return
status of netvsc_start_xmit())

In fact netif_tx_stop_queue() / netif_stop_queue() is needed before
returning NETDEV_TX_BUSY or you can trigger a ksoftirqd fatal loop.

In case of memory allocation error, only safe way is to drop the packet
and return NETDEV_TX_OK
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

network drivers should reserve some headroom on incoming skbs so that we
dont need expensive reallocations, eg forwarding packets in tunnels.

This NET_SKB_PAD padding is done in various helpers, like
__netdev_alloc_skb_ip_align() in this patch, combining NET_SKB_PAD and
NET_IP_ALIGN magic.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Oliver Neukum <oneukum@suse.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

When cycling the interface down and up, bnx2x_init_firmware() knows that
the firmware is already loaded, but nevertheless it allocates certain
arrays anew (init_data, init_ops, init_ops_offsets, iro_arr). The old
arrays are leaked.

Fix the leaks by returning early if the firmware was already loaded.
Because if the firmware is loaded, so are the arrays.
Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
Acked-by: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

If the requested firmware is deemed corrupt and then released, reset the
pointer to NULL in order to avoid double-freeing it in
bnx2x_release_firmware() or dereferencing it in bnx2x_init_firmware().
Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
Acked-by: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This reverts commit d47a0ac7 (sch_sfq: dont put new flow at the end of
flows)

As Jesper found out, patch sounded great but has bad side effects.

In stress situation, pushing new flows in front of the queue can prevent
old flows doing any progress. Packets can stay in SFQ queue for
unlimited amount of time.

It's possible to add heuristics to limit this problem, but this would
add complexity outside of SFQ scope.

A more sensible answer to Dave Taht concerns (who reported the issued I
tried to solve in original commit) is probably to use a qdisc hierarchy
so that high prio packets dont enter a potentially crowded SFQ qdisc.
Reported-by: Jesper Dangaard Brouer <jdb@comx.dk>
Cc: Dave Taht <dave.taht@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

commit 87a11578 ( ipv6: Move xfrm_lookup() call down into
icmp6_dst_alloc().) forgot to convert one error path, leading
to crashes in mld_sendpack()

Many thanks to Dave Jones for providing a very complete bug report.
Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add Serge as maintainer of capabilities, per suggestion on LWN:
http://lwn.net/Articles/486306/Signed-off-by: James Morris <james.l.morris@oracle.com>

Merge patches from Andrew Morton:
 "Nine patches - some bug fixes and some MAINTAINERS fiddling."

* emailed from Andrew Morton <akpm@linux-foundation.org>:
  drivers/video/backlight/s6e63m0.c: fix corruption storing gamma mode
  MAINTAINERS: add entry for exynos mipi display drivers
  MAINTAINERS: fix link to Gustavo Padovans tree
  MAINTAINERS: add Johan to Bluetooth maintainers
  MAINTAINERS: Gustavo has moved
  prctl: use CAP_SYS_RESOURCE for PR_SET_MM option
  rapidio/tsi721: fix bug in register offset definitions
  MAINTAINERS: update ST's Mailing list for SPEAr
  memcg: free mem_cgroup by RCU to fix oops

Pull i2c subsystem fixes from Jean Delvare.

* 'i2c-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging:
  i2c-algo-bit: Fix spurious SCL timeouts under heavy load
  i2c-core: Comment says "transmitted" but means "received"

Pull hwmon fixes from Guenter Roeck.

* tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: (zl6100) Enable interval between chip accesses for all chips
  hwmon: (w83627ehf) Describe undocumented pwm attributes
  hwmon: (w83627ehf) Fix temp2 source for W83627UHG
  hwmon: (w83627ehf) Fix memory leak in probe function
  hwmon: (w83627ehf) Fix writing into fan_stop_time for NCT6775F/NCT6776F

Pull drm exynos/intel updates from Dave Airlie:
 "Two minor updates from Jesse for Intel SNB fixes, and a few fixes from
  Samsung for exynos.  The pull req has Alan's commit in it since Intel
  based their tree on my tree at that time, but it all seems fine wrt
  merging."

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  drm exynos: use drm_fb_helper_set_par directly
  drm/exynos: Fix fb_videomode <-> drm_mode_modeinfo conversion
  drm/exynos: fix runtime_pm fimd device state on probe
  drm/exynos: use correct 'exynos-drm' name for platform device
  drm/i915: support 32 bit BGR formats in sprite planes
  drm/i915: fix color order for BGR formats on SNB
  drm/gma500: Fix Cedarview boot failures in 3.3-rc

Pull media fixes from Mauro Carvalho Chehab:
 "For 4 fixes for 3.3 (all trivial):
       - uvc video driver: fixes a division by zero;
       - davinci: add module.h to fix compilation;
       - smsusb: fix the delivery system setting;
       - smsdvb: the get_frontend implementation there is broken.

  The smsdvb patch has 127 lines, but it is trivial: instead of
  returning a cache of the set_frontend (with is wrong, as it doesn't
  have the updated values for the data, and the implementation there is
  buggy), it copies the information of the detected DVB parameters from
  the smsdvb private structures into the corresponding DVBv5 struct
  fields."

* 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media:
  [media] smsdvb: fix get_frontend
  [media] smsusb: fix the default delivery system setting
  [media] media: davinci: added module.h to resolve unresolved macros
  [media] [FOR,v3.3] uvcvideo: Avoid division by 0 in timestamp calculation

Pull target fixes from Nicholas Bellinger:
 "This series addresses two recently reported regression bugs related to
  legacy SCSI reservation usage in target core, and iscsi-target
  reservation conflict handling.

  The second patch in particular addresses possible data-corruption with
  SCSI reservations that is specific to iscsi-target fabric LUNs with
  multiple client writers.  Both patches need to go into v3.2 stable
  ASAP, and the branch based on the last target-pending/3.3-rc-fixes
  HEAD.

  Again, thanks to Martin Svec for his help to identify and address this
  regression bug with iscsi-target."

* '3.3-urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending:
  iscsi-target: Fix reservation conflict -EBUSY response handling bug
  target: Fix compatible reservation handling (CRH=1) with legacy RESERVE/RELEASE

strict_strtoul() writes a long but ->gamma_mode only has space to store an
int, so on 64 bit systems we end up scribbling over ->gamma_table_count as
well.  I've changed it to use kstrtouint() instead.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>