In-core acls are copy-on-write, so the reference taken by set_cached_acl() will
do just fine.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

new helper: posix_acl_chmod(&acl, gfp, mode).  Replaces acl with modified
clone or with NULL if that has failed; returns 0 or -ve on error.  All
callers of posix_acl_chmod_masq() switched to that - they'd been doing
exactly the same thing.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Always set up a negative ACL cache entry if the inode can't have ACLs.
That behaves much better than doing this check inside ->check_acl.

Also remove the left over MAY_NOT_BLOCK check.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Always set up a negative ACL cache entry if the inode doesn't have an
attribute fork.  That behaves much better than doing this check inside
->check_acl.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

If we do not want to use ACLs we at least need to perform normal Unix
permission checks.  From the comment I'm not quite sure that's what
is intended, but if 0p wants to do permission checks entirely on the
server it needs to do so in ->permission, not in ->check_acl.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

This moves logic for checking the cached ACL values from low-level
filesystems into generic code.  The end result is a streamlined ACL
check that doesn't need to load the inode->i_op->check_acl pointer at
all for the common cached case.

The filesystems also don't need to check for a non-blocking RCU walk
case in their acl_check() functions, because that is all handled at a
VFS layer.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

commit fec11dd9 caused
a regression when we have already mounted //server/share/a
and want to mount //server/share/a/b.

The problem is that lookup_one_len calls __lookup_hash
with nd pointer as NULL. Then __lookup_hash calls
do_revalidate in the case when dentry exists and we end
up with NULL pointer deference in cifs_d_revalidate:

if (nd->flags & LOOKUP_RCU)
	return -ECHILD;

Fix this by checking nd for NULL.
Signed-off-by: Pavel Shilovsky <piastryyy@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

The fsync prototype change commit 02c24a82 accidentally overwrote
the ssize_t return value of xfs_file_aio_write with 0 for SYNC type
writes. Fix this by checking if an error occured when calling
xfs_file_fsync and only change the return value in this case.
In addition xfs_file_fsync actually returns a normal negative error, so
fix this, too.
Signed-off-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

After we's done complete(&req->done), there's nothing to prevent the
scope containing *req from being gone and *req overwritten by any
kind of junk.  So we must read req->next before that...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

it will be replaced with S_IFREG anyway
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

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

It's mode_t; return 0 (no access) on error.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

casting int * to mode_t * is not a good thing - on a *lot* of big-endian
architectures mode_t happens to be smaller than int and there it breaks
quite spectaculary...

Fucked-up-by: commit cfc8dc6fSigned-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>

For a number of file systems that don't have a mount point (e.g. sockfs
and pipefs), they are not marked as long term. Therefore in
mntput_no_expire, all locks in vfs_mount lock are taken instead of just
local cpu's lock to aggregate reference counts when we release
reference to file objects.  In fact, only local lock need to have been
taken to update ref counts as these file systems are in no danger of
going away until we are ready to unregister them.

The attached patch marks file systems using kern_mount without
mount point as long term.  The contentions of vfs_mount lock
is now eliminated.  Before un-registering such file system,
kern_unmount should be called to remove the long term flag and
make the mount point ready to be freed.
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (107 commits)
  vfs: use ERR_CAST for err-ptr tossing in lookup_instantiate_filp
  isofs: Remove global fs lock
  jffs2: fix IN_DELETE_SELF on overwriting rename() killing a directory
  fix IN_DELETE_SELF on overwriting rename() on ramfs et.al.
  mm/truncate.c: fix build for CONFIG_BLOCK not enabled
  fs:update the NOTE of the file_operations structure
  Remove dead code in dget_parent()
  AFS: Fix silly characters in a comment
  switch d_add_ci() to d_splice_alias() in "found negative" case as well
  simplify gfs2_lookup()
  jfs_lookup(): don't bother with . or ..
  get rid of useless dget_parent() in btrfs rename() and link()
  get rid of useless dget_parent() in fs/btrfs/ioctl.c
  fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlers
  drivers: fix up various ->llseek() implementations
  fs: handle SEEK_HOLE/SEEK_DATA properly in all fs's that define their own llseek
  Ext4: handle SEEK_HOLE/SEEK_DATA generically
  Btrfs: implement our own ->llseek
  fs: add SEEK_HOLE and SEEK_DATA flags
  reiserfs: make reiserfs default to barrier=flush
  ...

Fix up trivial conflicts in fs/xfs/linux-2.6/xfs_super.c due to the new
shrinker callout for the inode cache, that clashed with the xfs code to
start the periodic workers later.

Merge branch 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86-64, vdso: Do not allocate memory for the vDSO
  clocksource: Change __ARCH_HAS_CLOCKSOURCE_DATA to a CONFIG option
  x86, vdso: Drop now wrong comment
  Document the vDSO and add a reference parser
  ia64: Replace clocksource.fsys_mmio with generic arch data
  x86-64: Move vread_tsc and vread_hpet into the vDSO
  clocksource: Replace vread with generic arch data
  x86-64: Add --no-undefined to vDSO build
  x86-64: Allow alternative patching in the vDSO
  x86: Make alternative instruction pointers relative
  x86-64: Improve vsyscall emulation CS and RIP handling
  x86-64: Emulate legacy vsyscalls
  x86-64: Fill unused parts of the vsyscall page with 0xcc
  x86-64: Remove vsyscall number 3 (venosys)
  x86-64: Map the HPET NX
  x86-64: Remove kernel.vsyscall64 sysctl
  x86-64: Give vvars their own page
  x86-64: Document some of entry_64.S
  x86-64: Fix alignment of jiffies variable

* 'x86-uv-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, UV: Correct UV2 BAU destination timeout
  x86, UV: Correct failed topology memory leak
  x86, UV: Remove cpumask_t from the stack
  x86, UV: Rename hubmask to pnmask
  x86, UV: Correct reset_with_ipi()
  x86, UV: Allow for non-consecutive sockets
  x86, UV: Inline header file functions
  x86, UV: Fix smp_processor_id() use in a preemptable region
  x66, UV: Enable 64-bit ACPI MFCG support for SGI UV2 platform
  x86, UV: Clean up uv_mmrs.h

Merge branch 'x86-signal-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-signal-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: Kill handle_signal()->set_fs()
  x86, do_signal: Simplify the TS_RESTORE_SIGMASK logic
  x86, signals: Convert the X86_32 code to use set_current_blocked()
  x86, signals: Convert the IA32_EMULATION code to use set_current_blocked()

Merge branch 'x86-numa-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-numa-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, numa: Implement pfn -> nid mapping granularity check
  x86, mm: s/PAGES_PER_ELEMENT/PAGES_PER_SECTION/

Merge branch 'x86-mtrr-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-mtrr-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, mtrr: Use pci_dev->revision
  x86, mtrr: use stop_machine APIs for doing MTRR rendezvous
  stop_machine: implement stop_machine_from_inactive_cpu()
  stop_machine: reorganize stop_cpus() implementation
  x86, mtrr: lock stop machine during MTRR rendezvous sequence

Merge branch 'x86-microcode-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-microcode-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, microcode, AMD: Fix section header size check
  x86, microcode, AMD: Correct buf references

* 'x86-mce-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, mce: Use mce_sysdev_ prefix to group functions
  x86, mce: Use mce_chrdev_ prefix to group functions
  x86, mce: Cleanup mce_read()
  x86, mce: Cleanup mce_create()/remove_device()
  x86, mce: Check the result of ancient_init()
  x86, mce: Introduce mce_gather_info()
  x86, mce: Replace MCM_ with MCI_MISC_
  x86, mce: Replace MCE_SELF_VECTOR by irq_work
  x86, mce, severity: Clean up trivial coding style problems
  x86, mce, severity: Cleanup severity table
  x86, mce, severity: Make formatting a bit more readable
  x86, mce, severity: Fix two severities table signatures

* 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, efi: Properly pre-initialize table pointers
  x86, efi: Add infrastructure for UEFI 2.0 runtime services
  x86, efi: Fix argument types for SetVariable()

* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, intel, power: Correct the MSR_IA32_ENERGY_PERF_BIAS message
  x86, msr: Fix typo in ENERGY_PERF_BIAS_POWERSAVE
  x86, intel, power: Initialize MSR_IA32_ENERGY_PERF_BIAS

Merge branch 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, smpboot: Mark the names[] array in __inquire_remote_apic() as const
  x86: Convert vmalloc()+memset() to vzalloc()

* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: Fix write lock scalability 64-bit issue
  x86: Unify rwsem assembly implementation
  x86: Unify rwlock assembly implementation
  x86, asm: Fix binutils 2.16 issue with __USER32_CS
  x86, asm: Cleanup thunk_64.S
  x86, asm: Flip RESTORE_ARGS arguments logic
  x86, asm: Flip SAVE_ARGS arguments logic
  x86, asm: Thin down SAVE/RESTORE_* asm macros

Merge branch 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86, ioapic: Print IR_IO_APIC_route_entry when IR is enabled
  x86, ioapic: Print IRTE when IR is enabled
  x86, x2apic: Preserve high 32-bits of IA32_APIC_BASE MSR
  x86, ioapic: Also print Dest field
  x86, ioapic: Format clean up for IOAPIC output
  x86: print APIC data a little later during boot

Merge branch 'timers-rtc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'timers-rtc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: Serialize EFI time accesses on rtc_lock
  x86: Serialize SMP bootup CMOS accesses on rtc_lock
  rtc: stmp3xxx: Remove UIE handlers
  rtc: stmp3xxx: Get rid of mach-specific accessors
  rtc: stmp3xxx: Initialize drvdata before registering device
  rtc: stmp3xxx: Port stmp-functions to mxs-equivalents
  rtc: stmp3xxx: Restore register definitions
  rtc: vt8500: Use define instead of hardcoded value for status bit

Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  time: Fix stupid KERN_WARN compile issue
  rtc: Avoid accumulating time drift in suspend/resume
  time: Avoid accumulating time drift in suspend/resume
  time: Catch invalid timespec sleep values in __timekeeping_inject_sleeptime

Merge branch 'timers-cleanup-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'timers-cleanup-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  mips: Fix i8253 clockevent fallout
  i8253: Cleanup outb/inb magic
  arm: Footbridge: Use common i8253 clockevent
  mips: Use common i8253 clockevent
  x86: Use common i8253 clockevent
  i8253: Create common clockevent implementation
  i8253: Export i8253_lock unconditionally
  pcpskr: MIPS: Make config dependencies finer grained
  pcspkr: Cleanup Kconfig dependencies
  i8253: Move remaining content and delete asm/i8253.h
  i8253: Consolidate definitions of PIT_LATCH
  x86: i8253: Consolidate definitions of global_clock_event
  i8253: Alpha, PowerPC: Remove unused asm/8253pit.h
  alpha: i8253: Cleanup remaining users of i8253pit.h
  i8253: Remove I8253_LOCK config
  i8253: Make pcsp sound driver use the shared i8253_lock
  i8253: Make pcspkr input driver use the shared i8253_lock
  i8253: Consolidate all kernel definitions of i8253_lock
  i8253: Unify all kernel declarations of i8253_lock
  i8253: Create linux/i8253.h and use it in all 8253 related files

Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (24 commits)
  sched: Cleanup duplicate local variable in [enqueue|dequeue]_task_fair
  sched: Replace use of entity_key()
  sched: Separate group-scheduling code more clearly
  sched: Reorder root_domain to remove 64 bit alignment padding
  sched: Do not attempt to destroy uninitialized rt_bandwidth
  sched: Remove unused function cpu_cfs_rq()
  sched: Fix (harmless) typo 'CONFG_FAIR_GROUP_SCHED'
  sched, cgroup: Optimize load_balance_fair()
  sched: Don't update shares twice on on_rq parent
  sched: update correct entity's runtime in check_preempt_wakeup()
  xtensa: Use generic config PREEMPT definition
  h8300: Use generic config PREEMPT definition
  m32r: Use generic PREEMPT config
  sched: Skip autogroup when looking for all rt sched groups
  sched: Simplify mutex_spin_on_owner()
  sched: Remove rcu_read_lock() from wake_affine()
  sched: Generalize sleep inside spinlock detection
  sched: Make sleeping inside spinlock detection working in !CONFIG_PREEMPT
  sched: Isolate preempt counting in its own config option
  sched: Remove pointless in_atomic() definition check
  ...

Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (123 commits)
  perf: Remove the nmi parameter from the oprofile_perf backend
  x86, perf: Make copy_from_user_nmi() a library function
  perf: Remove perf_event_attr::type check
  x86, perf: P4 PMU - Fix typos in comments and style cleanup
  perf tools: Make test use the preset debugfs path
  perf tools: Add automated tests for events parsing
  perf tools: De-opt the parse_events function
  perf script: Fix display of IP address for non-callchain path
  perf tools: Fix endian conversion reading event attr from file header
  perf tools: Add missing 'node' alias to the hw_cache[] array
  perf probe: Support adding probes on offline kernel modules
  perf probe: Add probed module in front of function
  perf probe: Introduce debuginfo to encapsulate dwarf information
  perf-probe: Move dwarf library routines to dwarf-aux.{c, h}
  perf probe: Remove redundant dwarf functions
  perf probe: Move strtailcmp to string.c
  perf probe: Rename DIE_FIND_CB_FOUND to DIE_FIND_CB_END
  tracing/kprobe: Update symbol reference when loading module
  tracing/kprobes: Support module init function probing
  kprobes: Return -ENOENT if probe point doesn't exist
  ...

Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  rcu: Fix wrong check in list_splice_init_rcu()
  net,rcu: Convert call_rcu(xt_rateest_free_rcu) to kfree_rcu()
  sysctl,rcu: Convert call_rcu(free_head) to kfree
  vmalloc,rcu: Convert call_rcu(rcu_free_vb) to kfree_rcu()
  vmalloc,rcu: Convert call_rcu(rcu_free_va) to kfree_rcu()
  ipc,rcu: Convert call_rcu(ipc_immediate_free) to kfree_rcu()
  ipc,rcu: Convert call_rcu(free_un) to kfree_rcu()
  security,rcu: Convert call_rcu(sel_netport_free) to kfree_rcu()
  security,rcu: Convert call_rcu(sel_netnode_free) to kfree_rcu()
  ia64,rcu: Convert call_rcu(sn_irq_info_free) to kfree_rcu()
  block,rcu: Convert call_rcu(disk_free_ptbl_rcu_cb) to kfree_rcu()
  scsi,rcu: Convert call_rcu(fc_rport_free_rcu) to kfree_rcu()
  audit_tree,rcu: Convert call_rcu(__put_tree) to kfree_rcu()
  security,rcu: Convert call_rcu(whitelist_item_free) to kfree_rcu()
  md,rcu: Convert call_rcu(free_conf) to kfree_rcu()

Merge branch 'core-printk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'core-printk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  lockdep: Fix trace_[soft,hard]irqs_[on,off]() recursion
  printk: Fix console_sem vs logbuf_lock unlock race
  printk: Release console_sem after logbuf_lock

Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  lockdep: Fix lockdep_no_validate against IRQ states
  mutex: Make mutex_destroy() an inline function
  plist: Remove the need to supply locks to plist heads
  lockup detector: Fix reference to the non-existent CONFIG_DETECT_SOFTLOCKUP option

Replace unclear (struct dentry *) to (struct file *) typecast with ERR_CAST() macro.
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

sbi->s_mutex isn't needed for isofs at all so we can just remove it. Generally,
since isofs is always mounted read-only, filesystem structure cannot change
under us.  So buffer_head contents stays constant after it's filled in. That
leaves us with possible changes of global data structures. Superblock changes
only during filesystem mount (even remount does not change it), inodes are only
filled in during reading from disk. So there are no changes of these structures
to bother about.

Arguments why sbi->s_mutex can be removed at each place:
isofs_readdir: Accesses sb, inode, filp, local variables => s_mutex not needed
isofs_lookup: Protected by directory's i_mutex. Accesses sb, inode, dentry,
  local variables => s_mutex not needed
rock_ridge_symlink_readpage: Protected by page lock. Accesses sb, inode,
  local variables => s_mutex not needed.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

We don't generate IN_DELETE_SELF on victim of overwriting rename() if
it happens to be a directory.  Trivially fixed by doing to ->i_nlink
what we do ->pino_nlink a couple of lines later in jffs2_rename().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>