Before replacing the inode hash locking with a more scalable
mechanism, factor the removal of the inode from the hashes rather
than open coding it in several places.

Based on a patch originally from Nick Piggin.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Convert the inode LRU to use lazy updates to reduce lock and
cacheline traffic.  We avoid moving inodes around in the LRU list
during iget/iput operations so these frequent operations don't need
to access the LRUs. Instead, we defer the refcount checks to
reclaim-time and use a per-inode state flag, I_REFERENCED, to tell
reclaim that iget has touched the inode in the past. This means that
only reclaim should be touching the LRU with any frequency, hence
significantly reducing lock acquisitions and the amount contention
on LRU updates.

This also removes the inode_in_use list, which means we now only
have one list for tracking the inode LRU status. This makes it much
simpler to split out the LRU list operations under it's own lock.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

The number of inodes allocated does not need to be tied to the
addition or removal of an inode to/from a list. If we are not tied
to a list lock, we could update the counters when inodes are
initialised or destroyed, but to do that we need to convert the
counters to be per-cpu (i.e. independent of a lock). This means that
we have the freedom to change the list/locking implementation
without needing to care about the counters.

Based on a patch originally from Eric Dumazet.

[AV: cleaned up a bit, fixed build breakage on weird configs
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

If clone_mnt() happens while mnt_make_readonly() is running, the
cloned mount might have MNT_WRITE_HOLD flag set, which results in
mnt_want_write() spinning forever on this mount.

Needs CAP_SYS_ADMIN to trigger deliberately and unlikely to happen
accidentally.  But if it does happen it can hang the machine.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Make node look as if it was on hlist, with hlist_del()
working correctly.  Usable without any locking...

Convert a couple of places where we want to do that to
inode->i_hash.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

note: for race-free uses you inode_lock held
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

We are in fill_super(); again, no inodes with zero i_count could
be around until we set MS_ACTIVE.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

In fill_super() we hadn't MS_ACTIVE set yet, so there won't
be any inodes with zero i_count sitting around.

In put_super() we already have MS_ACTIVE removed *and* we
had called invalidate_inodes() since then.  So again there
won't be any inodes with zero i_count...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

It's pointless - we *do* have busy inodes (root directory,
for one), so that call will fail and attempt to change
XIP flag will be ignored.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

If we have the appropriate page already, call __block_write_begin()
directly instead of releasing and regrabbing it inside of
block_write_begin().
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Since inode->i_mode shares its bits for S_IFMT, S_ISDIR should be
used to distinguish whether it is a dir or not.
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

The aio batching code is using igrab to get an extra reference on the
inode so it can safely batch.  igrab will go ahead and take the global
inode spinlock, which can be a bottleneck on large machines doing lots
of AIO.

In this case, igrab isn't required because we already have a reference
on the file handle.  It is safe to just bump the i_count directly
on the inode.

Benchmarking shows this patch brings IOP/s on tons of flash up by about
2.5X.
Signed-off-by: Chris Mason <chris.mason@oracle.com>

Updated Documentation/filesystems/Locking to match the code.
Signed-off-by: Christoph Hellwig <hch@lst.de>

bh->b_private is initialized within init_buffer(), thus the
assignment should be redundant. Remove it.
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Move the EXPORTFS kconfig symbol out of the NETWORK_FILESYSTEMS block
since it provides a library function that can be (and is) used by other
(non-network) filesystems.

This also eliminates a kconfig dependency warning:

warning: (XFS_FS && BLOCK || NFSD && NETWORK_FILESYSTEMS && INET && FILE_LOCKING && BKL) selects EXPORTFS which has unmet direct dependencies (NETWORK_FILESYSTEMS)
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Alex Elder <aelder@sgi.com>
Cc: xfs-masters@oss.sgi.com
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Use sync_dirty_buffer instead of the incorrect opencoding it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Now, rw_verify_area() checsk f_pos is negative or not.  And if negative,
returns -EINVAL.

But, some special files as /dev/(k)mem and /proc/<pid>/mem etc..  has
negative offsets.  And we can't do any access via read/write to the
file(device).

So introduce FMODE_UNSIGNED_OFFSET to allow negative file offsets.
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

365b1818 ("add f_flags to struct statfs(64)") resized f_spare within
struct statfs which caused a UML crash.  There is no need to copy f_spare.
Signed-off-by: Richard Weinberger <richard@nod.at>
Reported-by: Toralf Förster <toralf.foerster@gmx.de>
Tested-by: Toralf Förster <toralf.foerster@gmx.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Documentation: Fix trivial typo in filesystems/sharedsubtree.txt

This typo is easy to ignore unless you have spent a great deal of time
thinking about how to eliminate duplicate dentries in unions.
Signed-off-by: Valerie Aurora <vaurora@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

The intent was to verify that bh = affs_bread_ino(...) returned a valid
pointer.  We checked "ext_bh" earlier in the function and it's valid
here.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Andrew,

Could you please review this patch, you probably are the right guy to
take it, because it crosses fs and net trees.

Note : /proc/sys/fs/file-nr is a read-only file, so this patch doesnt
depend on previous patch (sysctl: fix min/max handling in
__do_proc_doulongvec_minmax())

Thanks !

[PATCH V4] fs: allow for more than 2^31 files

Robin Holt tried to boot a 16TB system and found af_unix was overflowing
a 32bit value :

<quote>

We were seeing a failure which prevented boot.  The kernel was incapable
of creating either a named pipe or unix domain socket.  This comes down
to a common kernel function called unix_create1() which does:

        atomic_inc(&unix_nr_socks);
        if (atomic_read(&unix_nr_socks) > 2 * get_max_files())
                goto out;

The function get_max_files() is a simple return of files_stat.max_files.
files_stat.max_files is a signed integer and is computed in
fs/file_table.c's files_init().

        n = (mempages * (PAGE_SIZE / 1024)) / 10;
        files_stat.max_files = n;

In our case, mempages (total_ram_pages) is approx 3,758,096,384
(0xe0000000).  That leaves max_files at approximately 1,503,238,553.
This causes 2 * get_max_files() to integer overflow.

</quote>

Fix is to let /proc/sys/fs/file-nr & /proc/sys/fs/file-max use long
integers, and change af_unix to use an atomic_long_t instead of
atomic_t.

get_max_files() is changed to return an unsigned long.
get_nr_files() is changed to return a long.

unix_nr_socks is changed from atomic_t to atomic_long_t, while not
strictly needed to address Robin problem.

Before patch (on a 64bit kernel) :
# echo 2147483648 >/proc/sys/fs/file-max
# cat /proc/sys/fs/file-max
-18446744071562067968

After patch:
# echo 2147483648 >/proc/sys/fs/file-max
# cat /proc/sys/fs/file-max
2147483648
# cat /proc/sys/fs/file-nr
704     0       2147483648
Reported-by: Robin Holt <holt@sgi.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: David Miller <davem@davemloft.net>
Reviewed-by: Robin Holt <holt@sgi.com>
Tested-by: Robin Holt <holt@sgi.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Currently isofs_get_blocks() was limited to handle only 4TB files on 32-bit
architectures because of unnecessary use of iblock variable which was signed
long. Just remove the variable. The error messages that were using this
variable should have rather used b_off anyway because that is the block we
are currently mapping.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

__block_write_begin and block_prepare_write are identical except for slightly
different calling conventions.  Convert all callers to the __block_write_begin
calling conventions and drop block_prepare_write.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Hugetlbfs used to need it, but after the destroy_inode and evict_inode
changes it's not required anymore.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Add a new helper to write out the inode using the writeback code,
that is including the correct dirty bit and list manipulation.  A few
of filesystems already opencode this, and a lot of others should be
using it instead of using write_inode_now which also writes out the
data.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

The caller that didn't need it is gone.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Merge branch 'davinci-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/khilman/linux-davinci

* 'davinci-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/khilman/linux-davinci: (50 commits)
  davinci: fix remaining board support after io_pgoffst removal
  davinci: mityomapl138: make file local data static
  arm/davinci: remove duplicated include
  davinci: Initial support for Omapl138-Hawkboard
  davinci: MityDSP-L138/MityARM-1808 read MAC address from I2C Prom
  davinci: add tnetv107x touchscreen platform device
  input: add driver for tnetv107x touchscreen controller
  davinci: add keypad config for tnetv107x evm board
  davinci: add tnetv107x keypad platform device
  input: add driver for tnetv107x on-chip keypad controller
  net: davinci_emac: cleanup unused cpdma code
  net: davinci_emac: switch to new cpdma layer
  net: davinci_emac: separate out cpdma code
  net: davinci_emac: cleanup unused mdio emac code
  omap: cleanup unused davinci mdio arch code
  davinci: cleanup mdio arch code and switch to phy_id
  net: davinci_emac: switch to new mdio
  omap: add mdio platform devices
  davinci: add mdio platform devices
  net: davinci_emac: separate out davinci mdio
  ...

Fix up trivial conflict in drivers/input/keyboard/Kconfig (two entries
added next to each other - one from the davinci merge, one from the
input merge)

* 'for-linus' of git://git.open-osd.org/linux-open-osd:
  exofs: Remove inode->i_count manipulation in exofs_new_inode
  fs/exofs: typo fix of faild to failed
  exofs: Set i_mapping->backing_dev_info anyway
  exofs: Cleaup read path in regard with read_for_write

Commit b40827fa ("x86-32, mm: Add an initial page table for core
bootstrapping") added an include directive which is needless and is
taken care of by a previous one.  Remove it.
Caught-by: Jaswinder Singh Rajput <jaswinderlinux@gmail.com>
Signed-off-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

exofs_new_inode() was incrementing the inode->i_count and
decrementing it in create_done(), in a bad attempt to make sure
the inode will still be there when the asynchronous create_done()
finally arrives. This was very stupid because iput() was not called,
and if it was actually needed, it would leak the inode.

However all this is not needed, because at exofs_evict_inode()
we already wait for create_done() by waiting for the
object_created event. Therefore remove the superfluous ref counting
and just Thicken the comment at exofs_evict_inode() a bit.

While at it change places that open coded wait_obj_created()
to call the already available wrapper.

CC: Dave Chinner <dchinner@redhat.com>
CC: Christoph Hellwig <hch@lst.de>
CC: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>

* 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6: (48 commits)
  [S390] topology: export cpu topology via proc/sysinfo
  [S390] topology: move topology sysinfo code
  [S390] topology: clean up facility detection
  [S390] cleanup facility list handling
  [S390] enable ARCH_DMA_ADDR_T_64BIT with 64BIT
  [S390] dasd: ignore unsolicited interrupts for DIAG
  [S390] kvm: Enable z196 instruction facilities
  [S390] dasd: fix unsolicited interrupt recognition
  [S390] dasd: fix use after free in dbf
  [S390] kvm: Fix badness at include/asm/mmu_context.h:83
  [S390] cio: fix I/O cancel function
  [S390] topology: change default
  [S390] smp: use correct cpu address in print_cpu_info()
  [S390] remove ieee_instruction_pointer from thread_struct
  [S390] cleanup system call parameter setup
  [S390] correct alignment of cpuid structure
  [S390] cleanup lowcore access from external interrupts
  [S390] cleanup lowcore access from program checks
  [S390] pgtable: move pte_mkhuge() from hugetlb.h to pgtable.h
  [S390] fix SIGBUS handling
  ...

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6: (365 commits)
  ALSA: hda - Disable sticky PCM stream assignment for AD codecs
  ALSA: usb - Creative USB X-Fi volume knob support
  ALSA: ca0106: Use card specific dac id for mute controls.
  ALSA: ca0106: Allow different sound cards to use different SPI channel mappings.
  ALSA: ca0106: Create a nice spot for mapping channels to dacs.
  ALSA: ca0106: Move enabling of front dac out of hardcoded setup sequence.
  ALSA: ca0106: Pull out dac powering routine into separate function.
  ALSA: ca0106 - add Sound Blaster 5.1vx info.
  ASoC: tlv320dac33: Use usleep_range for delays
  ALSA: usb-audio: add Novation Launchpad support
  ALSA: hda - Add workarounds for CT-IBG controllers
  ALSA: hda - Fix wrong TLV mute bit for STAC/IDT codecs
  ASoC: tpa6130a2: Error handling for broken chip
  ASoC: max98088: Staticise m98088_eq_band
  ASoC: soc-core: Fix codec->name memory leak
  ALSA: hda - Apply ideapad quirk to Acer laptops with Cxt5066
  ALSA: hda - Add some workarounds for Creative IBG
  ALSA: hda - Fix wrong SPDIF NID assignment for CA0110
  ALSA: hda - Fix codec rename rules for ALC662-compatible codecs
  ALSA: hda - Add alc_init_jacks() call to other codecs
  ...

* 'for-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/dvrabel/uwb:
  uwb: Orphan the UWB and WUSB subsystems
  uwb: Remove the WLP subsystem and drivers

Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mjg59/platform-drivers-x86

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mjg59/platform-drivers-x86: (44 commits)
  eeepc-wmi: Add cpufv sysfs interface
  eeepc-wmi: add additional hotkeys
  panasonic-laptop: Simplify calls to acpi_pcc_retrieve_biosdata
  panasonic-laptop: Handle errors properly if they happen
  intel_pmic_gpio: fix off-by-one value range checking
  IBM Real-Time "SMI Free" mode driver -v7
  Add OLPC XO-1 rfkill driver
  Move hdaps driver to platform/x86
  ideapad-laptop: Fix Makefile
  intel_pmic_gpio: swap the bits and mask args for intel_scu_ipc_update_register
  ideapad: Add param: no_bt_rfkill
  ideapad: Change the driver name to ideapad-laptop
  ideapad: rewrite the sw rfkill set
  ideapad: rewrite the hw rfkill notify
  ideapad: use EC command to control camera
  ideapad: use return value of _CFG to tell if device exist or not
  ideapad: make sure we bind on the correct device
  ideapad: check VPC bit before sync rfkill hw status
  ideapad: add ACPI helpers
  dell-laptop: Add debugfs support
  ...

* 'next-devicetree' of git://git.secretlab.ca/git/linux-2.6:
  mtd/m25p80: add support to parse the partitions by OF node
  of/irq: of_irq.c needs to include linux/irq.h
  of/mips: Cleanup some include directives/files.
  of/mips: Add device tree support to MIPS
  of/flattree: Eliminate need to provide early_init_dt_scan_chosen_arch
  of/device: Rework to use common platform_device_alloc() for allocating devices
  of/xsysace: Fix OF probing on little-endian systems
  of: use __be32 types for big-endian device tree data
  of/irq: remove references to NO_IRQ in drivers/of/platform.c
  of/promtree: add package-to-path support to pdt
  of/promtree: add of_pdt namespace to pdt code
  of/promtree: no longer call prom_ functions directly; use an ops structure
  of/promtree: make drivers/of/pdt.c no longer sparc-only
  sparc: break out some PROM device-tree building code out into drivers/of
  of/sparc: convert various prom_* functions to use phandle
  sparc: stop exporting openprom.h header
  powerpc, of_serial: Endianness issues setting up the serial ports
  of: MTD: Fix OF probing on little-endian systems
  of: GPIO: Fix OF probing on little-endian systems

Commit b0ae1981 ("security: remove unused parameter from
security_task_setscheduler()") broke the build of
arch/mips/kernel/mips-mt-fpaff.c.  The function arguments were
unnecessary, not the semicolon ...
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>