to prevent the mutex being unlocked twice if we interrupt a blocked lock.
Signed-off-by: NPavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: NSteve French <smfrench@gmail.com>

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/hch/vfs-queue: (21 commits)
  leases: fix write-open/read-lease race
  nfs: drop unnecessary locking in llseek
  ext4: replace cut'n'pasted llseek code with generic_file_llseek_size
  vfs: add generic_file_llseek_size
  vfs: do (nearly) lockless generic_file_llseek
  direct-io: merge direct_io_walker into __blockdev_direct_IO
  direct-io: inline the complete submission path
  direct-io: separate map_bh from dio
  direct-io: use a slab cache for struct dio
  direct-io: rearrange fields in dio/dio_submit to avoid holes
  direct-io: fix a wrong comment
  direct-io: separate fields only used in the submission path from struct dio
  vfs: fix spinning prevention in prune_icache_sb
  vfs: add a comment to inode_permission()
  vfs: pass all mask flags check_acl and posix_acl_permission
  vfs: add hex format for MAY_* flag values
  vfs: indicate that the permission functions take all the MAY_* flags
  compat: sync compat_stats with statfs.
  vfs: add "device" tag to /proc/self/mountstats
  cleanup: vfs: small comment fix for block_invalidatepage
  ...

Fix up trivial conflict in fs/gfs2/file.c (llseek changes)

* http://sucs.org/~rohan/git/gfs2-3.0-nmw: (24 commits)
  GFS2: Move readahead of metadata during deallocation into its own function
  GFS2: Remove two unused variables
  GFS2: Misc fixes
  GFS2: rewrite fallocate code to write blocks directly
  GFS2: speed up delete/unlink performance for large files
  GFS2: Fix off-by-one in gfs2_blk2rgrpd
  GFS2: Clean up ->page_mkwrite
  GFS2: Correctly set goal block after allocation
  GFS2: Fix AIL flush issue during fsync
  GFS2: Use cached rgrp in gfs2_rlist_add()
  GFS2: Call do_strip() directly from recursive_scan()
  GFS2: Remove obsolete assert
  GFS2: Cache the most recently used resource group in the inode
  GFS2: Make resource groups "append only" during life of fs
  GFS2: Use rbtree for resource groups and clean up bitmap buffer ref count scheme
  GFS2: Fix lseek after SEEK_DATA, SEEK_HOLE have been added
  GFS2: Clean up gfs2_create
  GFS2: Use ->dirty_inode()
  GFS2: Fix bug trap and journaled data fsync
  GFS2: Fix inode allocation error path
  ...

* '3.2-without-smb2' of git://git.samba.org/sfrench/cifs-2.6: (52 commits)
  Fix build break when freezer not configured
  Add definition for share encryption
  CIFS: Make cifs_push_locks send as many locks at once as possible
  CIFS: Send as many mandatory unlock ranges at once as possible
  CIFS: Implement caching mechanism for posix brlocks
  CIFS: Implement caching mechanism for mandatory brlocks
  CIFS: Fix DFS handling in cifs_get_file_info
  CIFS: Fix error handling in cifs_readv_complete
  [CIFS] Fixup trivial checkpatch warning
  [CIFS] Show nostrictsync and noperm mount options in /proc/mounts
  cifs, freezer: add wait_event_freezekillable and have cifs use it
  cifs: allow cifs_max_pending to be readable under /sys/module/cifs/parameters
  cifs: tune bdi.ra_pages in accordance with the rsize
  cifs: allow for larger rsize= options and change defaults
  cifs: convert cifs_readpages to use async reads
  cifs: add cifs_async_readv
  cifs: fix protocol definition for READ_RSP
  cifs: add a callback function to receive the rest of the frame
  cifs: break out 3rd receive phase into separate function
  cifs: find mid earlier in receive codepath
  ...

* 'for-linus' of git://oss.sgi.com/xfs/xfs: (69 commits)
  xfs: add AIL pushing tracepoints
  xfs: put in missed fix for merge problem
  xfs: do not flush data workqueues in xfs_flush_buftarg
  xfs: remove XFS_bflush
  xfs: remove xfs_buf_target_name
  xfs: use xfs_ioerror_alert in xfs_buf_iodone_callbacks
  xfs: clean up xfs_ioerror_alert
  xfs: clean up buffer allocation
  xfs: remove buffers from the delwri list in xfs_buf_stale
  xfs: remove XFS_BUF_STALE and XFS_BUF_SUPER_STALE
  xfs: remove XFS_BUF_SET_VTYPE and XFS_BUF_SET_VTYPE_REF
  xfs: remove XFS_BUF_FINISH_IOWAIT
  xfs: remove xfs_get_buftarg_list
  xfs: fix buffer flushing during unmount
  xfs: optimize fsync on directories
  xfs: reduce the number of log forces from tail pushing
  xfs: Don't allocate new buffers on every call to _xfs_buf_find
  xfs: simplify xfs_trans_ijoin* again
  xfs: unlock the inode before log force in xfs_change_file_space
  xfs: unlock the inode before log force in xfs_fs_nfs_commit_metadata
  ...

In setlease, we use i_writecount to decide whether we can give out a
read lease.

In open, we break leases before incrementing i_writecount.

There is therefore a window between the break lease and the i_writecount
increment when setlease could add a new read lease.

This would leave us with a simultaneous write open and read lease, which
shouldn't happen.
Signed-off-by: NJ. Bruce Fields <bfields@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

This makes NFS follow the standard generic_file_llseek locking scheme.

Cc: Trond.Myklebust@netapp.com
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

This gives ext4 the benefits of unlocked llseek.

Cc: tytso@mit.edu
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Add a generic_file_llseek variant to the VFS that allows passing in
the maximum file size of the file system, instead of always
using maxbytes from the superblock.

This can be used to eliminate some cut'n'paste seek code in ext4.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

The i_mutex lock use of generic _file_llseek hurts.  Independent processes
accessing the same file synchronize over a single lock, even though
they have no need for synchronization at all.

Under high utilization this can cause llseek to scale very poorly on larger
systems.

This patch does some rethinking of the llseek locking model:

First the 64bit f_pos is not necessarily atomic without locks
on 32bit systems. This can already cause races with read() today.
This was discussed on linux-kernel in the past and deemed acceptable.
The patch does not change that.

Let's look at the different seek variants:

SEEK_SET: Doesn't really need any locking.
If there's a race one writer wins, the other loses.

For 32bit the non atomic update races against read()
stay the same. Without a lock they can also happen
against write() now.  The read() race was deemed
acceptable in past discussions, and I think if it's
ok for read it's ok for write too.

=> Don't need a lock.

SEEK_END: This behaves like SEEK_SET plus it reads
the maximum size too. Reading the maximum size would have the
32bit atomic problem. But luckily we already have a way to read
the maximum size without locking (i_size_read), so we
can just use that instead.

Without i_mutex there is no synchronization with write() anymore,
however since the write() update is atomic on 64bit it just behaves
like another racy SEEK_SET.  On non atomic 32bit it's the same
as SEEK_SET.

=> Don't need a lock, but need to use i_size_read()

SEEK_CUR: This has a read-modify-write race window
on the same file. One could argue that any application
doing unsynchronized seeks on the same file is already broken.
But for the sake of not adding a regression here I'm
using the file->f_lock to synchronize this. Using this
lock is much better than the inode mutex because it doesn't
synchronize between processes.

=> So still need a lock, but can use a f_lock.

This patch implements this new scheme in generic_file_llseek.
I dropped generic_file_llseek_unlocked and changed all callers.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

This doesn't change anything for the compiler, but hch thought it would
make the code clearer.

I moved the reference counting into its own little inline.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Acked-by: NJeff Moyer <jmoyer@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Add inlines to all the submission path functions. While this increases
code size it also gives gcc a lot of optimization opportunities
in this critical hotpath.

In particular -- together with some other changes -- this
allows gcc to get rid of the unnecessary clearing of
sdio at the beginning and optimize the messy parameter passing.
Any non inlining of a function which takes a sdio parameter
would break this optimization because they cannot be done if the
address of a structure is taken.

Note that benefits are only seen with CONFIG_OPTIMIZE_INLINING
and CONFIG_CC_OPTIMIZE_FOR_SIZE both set to off.

This gives about 2.2% improvement on a large database benchmark
with a high IOPS rate.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Only a single b_private field in the map_bh buffer head is needed after
the submission path. Move map_bh separately to avoid storing
this information in the long term slab.

This avoids the weird 104 byte hole in struct dio_submit which also needed
to be memseted early.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

A direct slab call is slightly faster than kmalloc and can be better cached
per CPU. It also avoids rounding to the next kmalloc slab.

In addition this enforces cache line alignment for struct dio to avoid
any false sharing.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Acked-by: NJeff Moyer <jmoyer@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Fix most problems reported by pahole.

There is still a weird 104 byte hole after map_bh. I'm not sure what
causes this.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Acked-by: NJeff Moyer <jmoyer@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

There's nothing on the stack, even before my changes.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Acked-by: NJeff Moyer <jmoyer@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

This large, but largely mechanic, patch moves all fields in struct dio
that are only used in the submission path into a separate on stack
data structure. This has the advantage that the memory is very likely
cache hot, which is not guaranteed for memory fresh out of kmalloc.

This also gives gcc more optimization potential because it can easier
determine that there are no external aliases for these variables.

The sdio initialization is a initialization now instead of memset.
This allows gcc to break sdio into individual fields and optimize
away unnecessary zeroing (after all the functions are inlined)
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Acked-by: NJeff Moyer <jmoyer@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

We need to move the inode to the end of the list to actually make the
spinning prevention explained in the comment above it work.  With a
plain list_move it will simply stay in place as we're always reclaiming
from the head of the list.
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Acked-by: NJ. Bruce Fields <bfields@redhat.com>
Acked-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAndreas Gruenbacher <agruen@kernel.org>
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Acked-by: NJ. Bruce Fields <bfields@redhat.com>
Acked-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAndreas Gruenbacher <agruen@kernel.org>
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

We are going to add more flags and having them in hex format
make it simpler
Acked-by: NJ. Bruce Fields <bfields@redhat.com>
Acked-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Acked-by: NJ. Bruce Fields <bfields@redhat.com>
Acked-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAndreas Gruenbacher <agruen@kernel.org>
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

This was found by inspection while tracking a similar
bug in compat_statfs64, that has been fixed in mainline
since decemeber.

- This fixes a bug where not all of the f_spare fields
  were cleared on mips and s390.
- Add the f_flags field to struct compat_statfs
- Copy f_flags to userspace in case someone cares.
- Use __clear_user to copy the f_spare field to userspace
  to ensure that all of the elements of f_spare are cleared.
  On some architectures f_spare is has 5 ints and on some
  architectures f_spare only has 4 ints.  Which makes
  the previous technique of clearing each int individually
  broken.

I don't expect anyone actually uses the old statfs system
call anymore but if they do let them benefit from having
the compat and the native version working the same.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

* 'drm-core-next' of git://people.freedesktop.org/~airlied/linux: (290 commits)
  Revert "drm/ttm: add a way to bo_wait for either the last read or last write"
  Revert "drm/radeon/kms: add a new gem_wait ioctl with read/write flags"
  vmwgfx: Don't pass unused arguments to do_dirty functions
  vmwgfx: Emulate depth 32 framebuffers
  drm/radeon: Lower the severity of the radeon lockup messages.
  drm/i915/dp: Fix eDP on PCH DP on CPT/PPT
  drm/i915/dp: Introduce is_cpu_edp()
  drm/i915: use correct SPD type value
  drm/i915: fix ILK+ infoframe support
  drm/i915: add DP test request handling
  drm/i915: read full receiver capability field during DP hot plug
  drm/i915/dp: Remove eDP special cases from bandwidth checks
  drm/i915/dp: Fix the math in intel_dp_link_required
  drm/i915/panel: Always record the backlight level again (but cleverly)
  i915: Move i915_read/write out of line
  drm/i915: remove transcoder PLL mashing from mode_set per specs
  drm/i915: if transcoder disable fails, say which
  drm/i915: set watermarks for third pipe on IVB
  drm/i915: export a CPT mode set verification function
  drm/i915: fix transcoder PLL select masking
  ...

* 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86-64, doc: Remove int 0xcc from entry_64.S documentation
  x86, vsyscall: Add missing <asm/fixmap.h> to arch/x86/mm/fault.c

Fix up trivial conflicts in arch/x86/mm/fault.c (asm/fixmap.h vs
asm/vsyscall.h: both work, which to use? Whatever..)

* 'x86-uv-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: uv2: Workaround for UV2 Hub bug (system global address format)

* 'x86-spinlocks-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, ticketlock: remove obsolete comment
  x86, cmpxchg: Use __compiletime_error() to make usage messages a bit nicer
  x86, ticketlock: Make __ticket_spin_trylock common
  x86, ticketlock: Convert __ticket_spin_lock to use xadd()
  x86, ticketlock: Convert spin loop to C
  x86, ticketlock: Clean up types and accessors
  x86: Use xadd helper more widely
  x86: Add xadd helper macro
  x86, cmpxchg: Unify cmpxchg into cmpxchg.h
  x86, cmpxchg: Move 64-bit set64_bit() to match 32-bit
  x86, cmpxchg: Move 32-bit __cmpxchg_wrong_size to match 64 bit.
  x86, cmpxchg: <linux/alternative.h> has LOCK_PREFIX

* 'x86-rdrand-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, random: Verify RDRAND functionality and allow it to be disabled
  x86, random: Architectural inlines to get random integers with RDRAND
  random: Add support for architectural random hooks

Fix up trivial conflicts in drivers/char/random.c: the architectural
random hooks touched "get_random_int()" that was simplified to use MD5
and not do the keyptr thing any more (see commit 6e5714ea: "net:
Compute protocol sequence numbers and fragment IDs using MD5").

* 'x86-microcode-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, microcode, AMD: Add microcode revision to /proc/cpuinfo
  x86, microcode: Correct microcode revision format
  coretemp: Get microcode revision from cpu_data
  x86, intel: Use c->microcode for Atom errata check
  x86, intel: Output microcode revision in /proc/cpuinfo
  x86, microcode: Don't request microcode from userspace unnecessarily

Fix up trivial conflicts in arch/x86/kernel/cpu/amd.c (conflict between
moving AMD BSP code to cpu_dev helper function and adding AMD microcode
revision to /proc/cpuinfo code)

* 'x86-hyperv-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Hyper-V: Integrate the clocksource with Hyper-V detection code

Fix up conflicts in drivers/staging/hv/Makefile manually (some of the hv
code has moved out of staging to drivers/hv/)

* 'x86-geode-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: geode: New PCEngines Alix system driver

* 'x86-cpufeature-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, cpu: Add cpufeature flag for PCIDs

* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, amd: Include linux/elf.h since we use stuff from asm/elf.h
  x86: cache_info: Update calculation of AMD L3 cache indices
  x86: cache_info: Kill the atomic allocation in amd_init_l3_cache()
  x86: cache_info: Kill the moronic shadow struct
  x86: cache_info: Remove bogus free of amd_l3_cache data
  x86, amd: Include elf.h explicitly, prepare the code for the module.h split
  x86-32, amd: Move va_align definition to unbreak 32-bit build
  x86, amd: Move BSP code to cpu_dev helper
  x86: Add a BSP cpu_dev helper
  x86, amd: Avoid cache aliasing penalties on AMD family 15h

nfsiostat was failing to find mounted filesystems on kernels after
2.6.38 because of changes to show_vfsstat() by commit
c7f404b4.  This patch adds back the
"device" tag before the nfs server entry so scripts can parse the
mountstats file correctly.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
CC: stable@kernel.org [>=2.6.39]
Signed-off-by: NChristoph Hellwig <hch@lst.de>

The patch is aganist 3.1-rc3.
Signed-off-by: NWang Sheng-Hui <shhuiw@gmail.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Currently, when you call iov_iter_advance, then the pointer to the iovec
array can be incremented, but it does not decrement the nr_segs value in
the iov_iter struct. The result is a iov_iter struct with a nr_segs
value that goes beyond the end of the array.

While I'm not aware of anything that's specifically broken by this, it
seems odd and a bit dangerous not to decrement that value. If someone
were to trust the nr_segs value to be correct, then they could end up
walking off the end of the array.

Changing this might also provide some micro-optimization when dealing
with the last iovec in an array. Many of the other routines that deal
with iov_iter have optimized codepaths when nr_segs == 1.

Cc: Nick Piggin <npiggin@suse.de>
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

fs/cifs/transport.c: In function 'wait_for_response':
fs/cifs/transport.c:328: error: implicit declaration of function 'wait_event_freezekillable'

Caused by commit f06ac72e ("cifs, freezer: add
wait_event_freezekillable and have cifs use it").  In this config,
CONFIG_FREEZER is not set.
Reviewed-by: NShirish Pargaonkar <shirishp@us.ibm.com>
CC: Jeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <smfrench@gmail.com>

Samba supports a setfs info level to negotiate encrypted
shares.  This patch adds the defines so we recognize
this info level.  Later patches will add the enablement
for it.
Acked-by: NJeremy Allison <jra@samba.org>
Signed-off-by: NSteve French <smfrench@gmail.com>

This reverts commit dfadbbdb.

Further upstream discussion between Marek and Thomas decided this wasn't
fully baked and needed further work, so revert it before it hits mainline.
Signed-off-by: NDave Airlie <airlied@redhat.com>

This reverts commit d3ed7402.

Further upstream discussion between Thomas and Marek decided this needed
more work and driver specifics. So revert before it goes upstream.
Signed-off-by: NDave Airlie <airlied@redhat.com>