Add support to the core direct-io code to defer AIO completions to user
context using a workqueue.  This replaces opencoded and less efficient
code in XFS and ext4 (we save a memory allocation for each direct IO)
and will be needed to properly support O_(D)SYNC for AIO.

The communication between the filesystem and the direct I/O code requires
a new buffer head flag, which is a bit ugly but not avoidable until the
direct I/O code stops abusing the buffer_head structure for communicating
with the filesystems.

Currently this creates a per-superblock unbound workqueue for these
completions, which is taken from an earlier patch by Jan Kara.  I'm
not really convinced about this use and would prefer a "normal" global
workqueue with a high concurrency limit, but this needs further discussion.

JK: Fixed ext4 part, dynamic allocation of the workqueue.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

New formats: %p[dD][234]?.  The next pointer is interpreted as struct dentry *
or struct file * resp. ('d' => dentry, 'D' => file) and the last component(s)
of pathname are printed (%pd => just the last one, %pd2 => the last two, etc.)
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>

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>

Reviewed-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
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>

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>

same story as with oprofilefs_mkdir()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

it's always equal to ->d_sb of the second argument (parent dentry),
due to either being literally that, or ->d_sb of parent's parent.
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>

it's always root->d_sb
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

... and BTW, failing copy_to_user() means EFAULT, not EINVAL
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

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

Christopher reported a regression where he was unable to unmount a NFS
filesystem where the root had gone stale. The problem is that
d_revalidate handles the root of the filesystem differently from other
dentries, but d_weak_revalidate does not. We could simply fix this by
making d_weak_revalidate return success on IS_ROOT dentries, but there
are cases where we do want to revalidate the root of the fs.

A umount is really a special case. We generally aren't interested in
anything but the dentry and vfsmount that's attached at that point. If
the inode turns out to be stale we just don't care since the intent is
to stop using it anyway.

Try to handle this situation better by treating umount as a special
case in the lookup code. Have it resolve the parent using normal
means, and then do a lookup of the final dentry without revalidating
it. In most cases, the final lookup will come out of the dcache, but
the case where there's a trailing symlink or !LAST_NORM entry on the
end complicates things a bit.

Cc: Neil Brown <neilb@suse.de>
Reported-by: Christopher T Vogan <cvogan@us.ibm.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

The d_prune dentry operation is used to notify filesystem when VFS
about to prune a hashed dentry from the dcache. There are three
code paths that prune dentries: shrink_dcache_for_umount_subtree(),
prune_dcache_sb() and d_prune_aliases(). For the d_prune_aliases()
case, VFS unhashes the dentry first, then call the d_prune dentry
operation. This confuses ceph_d_prune() (ceph uses the d_prune
dentry operation to maintain a flag indicating whether the complete
contents of a directory are in the dcache, pruning unhashed dentry
does not affect dir's completeness)

This patch fixes the issue by calling the d_prune dentry operation
in d_prune_aliases(), before unhashing the dentry. Also make VFS
only call the d_prune dentry operation for hashed dentry, to avoid
calling the d_prune dentry operation twice when dentry is pruned
by d_prune_aliases().
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
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>

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

This should actually be returning an ERR_PTR on error instead of NULL.
That was how it was designed and all the callers expect it.

[AV: actually, that's what "VFS: Make clone_mnt()/copy_tree()/collect_mounts()
return errors" missed - originally collect_mounts() was expected to return
NULL on failure]

Cc: <stable@vger.kernel.org> # 3.10+
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

iget_locked() returns a NULL on error, it doesn't return an ERR_PTR.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

The iget_locked() function returns NULL on error and never an ERR_PTR.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

proc_readfd_common() does dir_emit_dots() twice in a row,
we need to do this only once.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

dynamic_dname() is both too much and too little for those - the
output may be well in excess of 64 bytes dynamic_dname() assumes
to be enough (thanks to ashmem feeding really long names to
shmem_file_setup()) and vsnprintf() is an overkill for those
guys.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Pull cgroup fix from Tejun Heo:
 "This contains one patch to fix the return value of cpuset's cgroups
  interface function, which used to always return -ENODEV for the writes
  on the 'memory_pressure_enabled' file"

* 'for-3.11-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cpuset: fix the return value of cpuset_write_u64()

Pull jbd2 bug fixes from Ted Ts'o:
 "Two jbd2 bug fixes, one of which is a regression fix"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  jbd2: Fix oops in jbd2_journal_file_inode()
  jbd2: Fix use after free after error in jbd2_journal_dirty_metadata()

Fix this build error:

  In file included from fs/exec.c:61:0:
  arch/s390/include/asm/tlb.h:35:23: error: expected identifier or '(' before 'unsigned'
  arch/s390/include/asm/tlb.h:36:1: warning: no semicolon at end of struct or union [enabled by default]
  arch/s390/include/asm/tlb.h: In function 'tlb_gather_mmu':
  arch/s390/include/asm/tlb.h:57:5: error: 'struct mmu_gather' has no member named 'end'

Broken due to commit 2b047252 ("Fix TLB gather virtual address range
invalidation corner cases").

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: stable@vger.kernel.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
[ Oh well. We had build testing for ppc amd um, but no s390  - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

I have taken a different job.  I am removing myself as maintainer of
GRU.  Dimitri will continue to maintain the SGI GRU driver, changing the
XP/XPC/XPNET maintainer to Cliff Whickman, but leaving behind my
personal email address to answer any questions about the design or
operation of the XP family of drivers.
Signed-off-by: Robin Holt <holt@sgi.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit 0713ed0c added
jbd2_journal_file_inode() call into ext4_block_zero_page_range().
However that function gets called from truncate path and thus inode
needn't have jinode attached - that happens in ext4_file_open() but
the file needn't be ever open since mount. Calling
jbd2_journal_file_inode() without jinode attached results in the oops.

We fix the problem by attaching jinode to inode also in ext4_truncate()
and ext4_punch_hole() when we are going to zero out partial blocks.
Reported-by: majianpeng <majianpeng@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

Pull ARM fixes from Russell King:
 "The usual collection of random fixes.  Also some further fixes to the
  last set of security fixes, and some more from Will (which you may
  already have in a slightly different form)"

* 'fixes' of git://git.linaro.org/people/rmk/linux-arm:
  ARM: 7807/1: kexec: validate CPU hotplug support
  ARM: 7812/1: rwlocks: retry trylock operation if strex fails on free lock
  ARM: 7811/1: locks: use early clobber in arch_spin_trylock
  ARM: 7810/1: perf: Fix array out of bounds access in armpmu_map_hw_event()
  ARM: 7809/1: perf: fix event validation for software group leaders
  ARM: Fix FIQ code on VIVT CPUs
  ARM: Fix !kuser helpers case
  ARM: Fix the world famous typo with is_gate_vma()

Pull m68k fixes from Geert Uytterhoeven:
 "These are two critical fixes, needed by distro kernels, and thus also
  destined for stable:

   - The do_div() commit fixes a crash in mounting btrfs volumes, which
     was a regression from 3.2,

   - The ARAnyM fix allows to have NatFeat drivers as loadable modules,
     which is needed for initrds"

* 'for-3.11' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k:
  m68k: Truncate base in do_div()
  m68k/atari: ARAnyM - Fix NatFeat module support

Pull clock controller fixes from Michael Turquette:
 "Two small fixes for the Zynq clock controller introduced in 3.11-rc1
  and another Exynos clock patch which fixes a regression that prevents
  the video pipeline from functioning on that platform"

* tag 'clk-fixes-for-linus' of git://git.linaro.org/people/mturquette/linux:
  clk: exynos4: Add CLK_GET_RATE_NOCACHE flag for the Exynos4x12 ISP clocks
  clk/zynq/clkc: Add CLK_SET_RATE_PARENT flag to ethernet muxes
  clk/zynq/clkc: Add dedicated spinlock for the SWDT

Pull power management fix from Rafael Wysocki:
 "The removal of delayed_work_pending() checks from kernel/power/qos.c
  done in 3.9 introduced a deadlock in pm_qos_work_fn().

  Fix from Stephen Boyd"

* tag 'pm-3.11-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PM / QoS: Fix workqueue deadlock when using pm_qos_update_request_timeout()