If a filesystem supports POSIX ACL's, the VFS layer expects the filesystem 
to do POSIX ACL checks on any files not owned by the caller, and it does 
this for every single pathname component that it looks up.

That obviously can be pretty expensive if the filesystem isn't careful 
about it, especially with locking. That's doubly sad, since the common 
case tends to be that there are no ACL's associated with the files in 
question.

ext3 already caches the ACL data so that it doesn't have to look it up 
over and over again, but it does so by taking the inode->i_lock spinlock 
on every lookup. Which is a noticeable overhead even if it's a private 
lock, especially on CPU's where the serialization is expensive (eg Intel 
Netburst aka 'P4').

For the special case of not actually having any ACL's, all that locking is 
unnecessary. Even if somebody else were to be changing the ACL's on 
another CPU, we simply don't care - if we've seen a NULL ACL, we might as 
well use it.

So just load the ACL speculatively without any locking, and if it was 
NULL, just use it. If it's non-NULL (either because we had a cached 
entry, or because the cache hasn't been filled in at all), it means that 
we'll need to get the lock and re-load it properly.

This is noticeable even on Nehalem, which does locking quite well (much 
better than P4). From lmbench:

	Processor, Processes - times in microseconds - smaller is better
	--------------------------------------------------------------------
	Host                 OS  Mhz null null      open slct fork exec sh  
	                             call  I/O stat clos TCP  proc proc proc
	--------- ------------- ---- ---- ---- ---- ---- ---- ---- ---- ----
 - before:
	nehalem.l Linux 2.6.30- 3193 0.04 0.09 0.95 1.45 2.18 69.1 273. 1141
	nehalem.l Linux 2.6.30- 3193 0.04 0.09 0.95 1.48 2.28 69.9 253. 1140
	nehalem.l Linux 2.6.30- 3193 0.04 0.10 0.95 1.42 2.19 68.6 284. 1141
 - after:
	nehalem.l Linux 2.6.30- 3193 0.04 0.09 0.92 1.44 2.12 68.3 282. 1094
	nehalem.l Linux 2.6.30- 3193 0.04 0.09 0.92 1.39 2.20 67.0 308. 1123
	nehalem.l Linux 2.6.30- 3193 0.04 0.09 0.92 1.39 2.36 67.4 293. 1148

where you can see what appears to be a roughly 3% improvement in stat
and open/close latencies from just the removal of the locking overhead. 

Of course, this only matters for files you don't own (the owner never 
needs to do the ACL checks), but that's the common case for libraries, 
header files, and executables. As well as for the base components of any 
absolute pathname, even if you are the owner of the final file.

[ At some point we probably want to move this ACL caching logic entirely
  into the VFS layer (and only call down to the filesystem when
  uncached), but in the meantime this improves ext3 a bit.

  A similar fix to btrfs makes a much bigger difference (15x improvement
  in lmbench) due to broken caching. ]
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Acked-by: NJan Kara <jack@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Authentication error abort codes should be translated to appropriate
Linux error codes, rather than all being translated to EREMOTEIO - which
indicates that the server had internal problems.

Additionally, a server shouldn't be marked unavailable and the next
server tried if an authentication error occurs.  This will quickly make
all the servers unavailable to the client.  Instead the error should be
returned straight to the user.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

CONFIG_FILE_LOCKING should not depend on CONFIG_BLOCK.

This makes it possible to run complete systems out of a CONFIG_BLOCK=n
initramfs on current kernels again (this last worked on 2.6.27.*).

Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

put_cpu_no_resched() is an optimization of put_cpu() which unfortunately
can cause high latencies.

The nfs iostats code uses put_cpu_no_resched() in a code sequence where a
reschedule request caused by an interrupt between the get_cpu() and the
put_cpu_no_resched() can delay the reschedule for at least HZ.

The other users of put_cpu_no_resched() optimize correctly in interrupt
code, but there is no real harm in using the put_cpu() function which is
an alias for preempt_enable().  The extra check of the preemmpt count is
not as critical as the potential source of missing a reschedule.

Debugged in the preempt-rt tree and verified in mainline.

Impact: remove a high latency source

[akpm@linux-foundation.org: build fix]
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NIngo Molnar <mingo@elte.hu>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

After introduction of keyed wakeups Davide Libenzi did on epoll, we are
able to avoid spurious wakeups in poll()/select() code too.

For example, typical use of poll()/select() is to wait for incoming
network frames on many sockets.  But TX completion for UDP/TCP frames call
sock_wfree() which in turn schedules thread.

When scheduled, thread does a full scan of all polled fds and can sleep
again, because nothing is really available.  If number of fds is large,
this cause significant load.

This patch makes select()/poll() aware of keyed wakeups and useless
wakeups are avoided.  This reduces number of context switches by about 50%
on some setups, and work performed by sofirq handlers.
Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Acked-by: NAndi Kleen <ak@linux.intel.com>
Acked-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NDavide Libenzi <davidel@xmailserver.org>
Cc: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NRobert P. J. Day <rpjday@crashcourse.ca>
Cc: Anton Altaparmakov <aia21@cantab.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

1) I_FREEING tests should be coupled with I_CLEAR

The two I_FREEING tests are racy because clear_inode() can set i_state to
I_CLEAR between the clear of I_SYNC and the test of I_FREEING.

2) skip I_WILL_FREE inodes in generic_sync_sb_inodes() to avoid possible
   races with generic_forget_inode()

generic_forget_inode() sets I_WILL_FREE call writeback on its own, so
generic_sync_sb_inodes() shall not try to step in and create possible races:

  generic_forget_inode
    inode->i_state |= I_WILL_FREE;
    spin_unlock(&inode_lock);
                                       generic_sync_sb_inodes()
                                         spin_lock(&inode_lock);
                                         __iget(inode);
                                         __writeback_single_inode
                                           // see non zero i_count
 may WARN here ==>                         WARN_ON(inode->i_state & I_WILL_FREE);
                                         spin_unlock(&inode_lock);
 may call generic_forget_inode again ==> iput(inode);

The above race and warning didn't turn up because writeback_inodes() holds
the s_umount lock, so generic_forget_inode() finds MS_ACTIVE and returns
early.  But we are not sure the UBIFS calls and future callers will
guarantee that.  So skip I_WILL_FREE inodes for the sake of safety.

Cc: Eric Sandeen <sandeen@sandeen.net>
Acked-by: NJeff Layton <jlayton@redhat.com>
Cc: Masayoshi MIZUMA <m.mizuma@jp.fujitsu.com>
Signed-off-by: NWu Fengguang <fengguang.wu@intel.com>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Acked-by: NJan Kara <jack@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove __invalidate_mapping_pages atomic variant now that its sole caller
can sleep (fixed in eccb95ce ("vfs: fix
lock inversion in drop_pagecache_sb()")).

This fixes softlockups that can occur while in the drop_caches path.
Signed-off-by: NMike Waychison <mikew@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Acked-by: NJan Kara <jack@suse.cz>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The per-task oom_adj value is a characteristic of its mm more than the
task itself since it's not possible to oom kill any thread that shares the
mm.  If a task were to be killed while attached to an mm that could not be
freed because another thread were set to OOM_DISABLE, it would have
needlessly been terminated since there is no potential for future memory
freeing.

This patch moves oomkilladj (now more appropriately named oom_adj) from
struct task_struct to struct mm_struct.  This requires task_lock() on a
task to check its oom_adj value to protect against exec, but it's already
necessary to take the lock when dereferencing the mm to find the total VM
size for the badness heuristic.

This fixes a livelock if the oom killer chooses a task and another thread
sharing the same memory has an oom_adj value of OOM_DISABLE.  This occurs
because oom_kill_task() repeatedly returns 1 and refuses to kill the
chosen task while select_bad_process() will repeatedly choose the same
task during the next retry.

Taking task_lock() in select_bad_process() to check for OOM_DISABLE and in
oom_kill_task() to check for threads sharing the same memory will be
removed in the next patch in this series where it will no longer be
necessary.

Writing to /proc/pid/oom_adj for a kthread will now return -EINVAL since
these threads are immune from oom killing already.  They simply report an
oom_adj value of OOM_DISABLE.

Cc: Nick Piggin <npiggin@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently, nobody wants to turn UNEVICTABLE_LRU off.  Thus this
configurability is unnecessary.
Signed-off-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Andi Kleen <andi@firstfloor.org>
Acked-by: NMinchan Kim <minchan.kim@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Export all page flags faithfully in /proc/kpageflags.

	11. KPF_MMAP		(pseudo flag) memory mapped page
	12. KPF_ANON		(pseudo flag) memory mapped page (anonymous)
	13. KPF_SWAPCACHE	page is in swap cache
	14. KPF_SWAPBACKED	page is swap/RAM backed
	15. KPF_COMPOUND_HEAD	(*)
	16. KPF_COMPOUND_TAIL	(*)
	17. KPF_HUGE		hugeTLB pages
	18. KPF_UNEVICTABLE	page is in the unevictable LRU list
	19. KPF_HWPOISON(TBD)	hardware detected corruption
	20. KPF_NOPAGE		(pseudo flag) no page frame at the address
	32-39.			more obscure flags for kernel developers

	(*) For compound pages, exporting _both_ head/tail info enables
	    users to tell where a compound page starts/ends, and its order.

The accompanying page-types tool will handle the details like decoupling
overloaded flags and hiding obscure flags to normal users.

Thanks to KOSAKI and Andi for their valuable recommendations!
Signed-off-by: NWu Fengguang <fengguang.wu@intel.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Move increments of pfn/out to bottom of the loop.
Signed-off-by: NWu Fengguang <fengguang.wu@intel.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Andi Kleen <andi@firstfloor.org>
Acked-by: NMatt Mackall <mpm@selenic.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

A series of patches to enhance the /proc/pagemap interface and to add a
userspace executable which can be used to present the pagemap data.

Export 10 more flags to end users (and more for kernel developers):

        11. KPF_MMAP            (pseudo flag) memory mapped page
        12. KPF_ANON            (pseudo flag) memory mapped page (anonymous)
        13. KPF_SWAPCACHE       page is in swap cache
        14. KPF_SWAPBACKED      page is swap/RAM backed
        15. KPF_COMPOUND_HEAD   (*)
        16. KPF_COMPOUND_TAIL   (*)
        17. KPF_HUGE		hugeTLB pages
        18. KPF_UNEVICTABLE     page is in the unevictable LRU list
        19. KPF_HWPOISON        hardware detected corruption
        20. KPF_NOPAGE          (pseudo flag) no page frame at the address

        (*) For compound pages, exporting _both_ head/tail info enables
            users to tell where a compound page starts/ends, and its order.

a simple demo of the page-types tool

# ./page-types -h
page-types [options]
            -r|--raw                  Raw mode, for kernel developers
            -a|--addr    addr-spec    Walk a range of pages
            -b|--bits    bits-spec    Walk pages with specified bits
            -l|--list                 Show page details in ranges
            -L|--list-each            Show page details one by one
            -N|--no-summary           Don't show summay info
            -h|--help                 Show this usage message
addr-spec:
            N                         one page at offset N (unit: pages)
            N+M                       pages range from N to N+M-1
            N,M                       pages range from N to M-1
            N,                        pages range from N to end
            ,M                        pages range from 0 to M
bits-spec:
            bit1,bit2                 (flags & (bit1|bit2)) != 0
            bit1,bit2=bit1            (flags & (bit1|bit2)) == bit1
            bit1,~bit2                (flags & (bit1|bit2)) == bit1
            =bit1,bit2                flags == (bit1|bit2)
bit-names:
          locked              error         referenced           uptodate
           dirty                lru             active               slab
       writeback            reclaim              buddy               mmap
       anonymous          swapcache         swapbacked      compound_head
   compound_tail               huge        unevictable           hwpoison
          nopage           reserved(r)         mlocked(r)    mappedtodisk(r)
         private(r)       private_2(r)   owner_private(r)            arch(r)
        uncached(r)       readahead(o)       slob_free(o)     slub_frozen(o)
      slub_debug(o)
                                   (r) raw mode bits  (o) overloaded bits

# ./page-types
             flags      page-count       MB  symbolic-flags                     long-symbolic-flags
0x0000000000000000          487369     1903  _________________________________
0x0000000000000014               5        0  __R_D____________________________  referenced,dirty
0x0000000000000020               1        0  _____l___________________________  lru
0x0000000000000024              34        0  __R__l___________________________  referenced,lru
0x0000000000000028            3838       14  ___U_l___________________________  uptodate,lru
0x0001000000000028              48        0  ___U_l_______________________I___  uptodate,lru,readahead
0x000000000000002c            6478       25  __RU_l___________________________  referenced,uptodate,lru
0x000100000000002c              47        0  __RU_l_______________________I___  referenced,uptodate,lru,readahead
0x0000000000000040            8344       32  ______A__________________________  active
0x0000000000000060               1        0  _____lA__________________________  lru,active
0x0000000000000068             348        1  ___U_lA__________________________  uptodate,lru,active
0x0001000000000068              12        0  ___U_lA______________________I___  uptodate,lru,active,readahead
0x000000000000006c             988        3  __RU_lA__________________________  referenced,uptodate,lru,active
0x000100000000006c              48        0  __RU_lA______________________I___  referenced,uptodate,lru,active,readahead
0x0000000000004078               1        0  ___UDlA_______b__________________  uptodate,dirty,lru,active,swapbacked
0x000000000000407c              34        0  __RUDlA_______b__________________  referenced,uptodate,dirty,lru,active,swapbacked
0x0000000000000400             503        1  __________B______________________  buddy
0x0000000000000804               1        0  __R________M_____________________  referenced,mmap
0x0000000000000828            1029        4  ___U_l_____M_____________________  uptodate,lru,mmap
0x0001000000000828              43        0  ___U_l_____M_________________I___  uptodate,lru,mmap,readahead
0x000000000000082c             382        1  __RU_l_____M_____________________  referenced,uptodate,lru,mmap
0x000100000000082c              12        0  __RU_l_____M_________________I___  referenced,uptodate,lru,mmap,readahead
0x0000000000000868             192        0  ___U_lA____M_____________________  uptodate,lru,active,mmap
0x0001000000000868              12        0  ___U_lA____M_________________I___  uptodate,lru,active,mmap,readahead
0x000000000000086c             800        3  __RU_lA____M_____________________  referenced,uptodate,lru,active,mmap
0x000100000000086c              31        0  __RU_lA____M_________________I___  referenced,uptodate,lru,active,mmap,readahead
0x0000000000004878               2        0  ___UDlA____M__b__________________  uptodate,dirty,lru,active,mmap,swapbacked
0x0000000000001000             492        1  ____________a____________________  anonymous
0x0000000000005808               4        0  ___U_______Ma_b__________________  uptodate,mmap,anonymous,swapbacked
0x0000000000005868            2839       11  ___U_lA____Ma_b__________________  uptodate,lru,active,mmap,anonymous,swapbacked
0x000000000000586c              30        0  __RU_lA____Ma_b__________________  referenced,uptodate,lru,active,mmap,anonymous,swapbacked
             total          513968     2007

# ./page-types -r
             flags      page-count       MB  symbolic-flags                     long-symbolic-flags
0x0000000000000000          468002     1828  _________________________________
0x0000000100000000           19102       74  _____________________r___________  reserved
0x0000000000008000              41        0  _______________H_________________  compound_head
0x0000000000010000             188        0  ________________T________________  compound_tail
0x0000000000008014               1        0  __R_D__________H_________________  referenced,dirty,compound_head
0x0000000000010014               4        0  __R_D___________T________________  referenced,dirty,compound_tail
0x0000000000000020               1        0  _____l___________________________  lru
0x0000000800000024              34        0  __R__l__________________P________  referenced,lru,private
0x0000000000000028            3794       14  ___U_l___________________________  uptodate,lru
0x0001000000000028              46        0  ___U_l_______________________I___  uptodate,lru,readahead
0x0000000400000028              44        0  ___U_l_________________d_________  uptodate,lru,mappedtodisk
0x0001000400000028               2        0  ___U_l_________________d_____I___  uptodate,lru,mappedtodisk,readahead
0x000000000000002c            6434       25  __RU_l___________________________  referenced,uptodate,lru
0x000100000000002c              47        0  __RU_l_______________________I___  referenced,uptodate,lru,readahead
0x000000040000002c              14        0  __RU_l_________________d_________  referenced,uptodate,lru,mappedtodisk
0x000000080000002c              30        0  __RU_l__________________P________  referenced,uptodate,lru,private
0x0000000800000040            8124       31  ______A_________________P________  active,private
0x0000000000000040             219        0  ______A__________________________  active
0x0000000800000060               1        0  _____lA_________________P________  lru,active,private
0x0000000000000068             322        1  ___U_lA__________________________  uptodate,lru,active
0x0001000000000068              12        0  ___U_lA______________________I___  uptodate,lru,active,readahead
0x0000000400000068              13        0  ___U_lA________________d_________  uptodate,lru,active,mappedtodisk
0x0000000800000068              12        0  ___U_lA_________________P________  uptodate,lru,active,private
0x000000000000006c             977        3  __RU_lA__________________________  referenced,uptodate,lru,active
0x000100000000006c              48        0  __RU_lA______________________I___  referenced,uptodate,lru,active,readahead
0x000000040000006c               5        0  __RU_lA________________d_________  referenced,uptodate,lru,active,mappedtodisk
0x000000080000006c               3        0  __RU_lA_________________P________  referenced,uptodate,lru,active,private
0x0000000c0000006c               3        0  __RU_lA________________dP________  referenced,uptodate,lru,active,mappedtodisk,private
0x0000000c00000068               1        0  ___U_lA________________dP________  uptodate,lru,active,mappedtodisk,private
0x0000000000004078               1        0  ___UDlA_______b__________________  uptodate,dirty,lru,active,swapbacked
0x000000000000407c              34        0  __RUDlA_______b__________________  referenced,uptodate,dirty,lru,active,swapbacked
0x0000000000000400             538        2  __________B______________________  buddy
0x0000000000000804               1        0  __R________M_____________________  referenced,mmap
0x0000000000000828            1029        4  ___U_l_____M_____________________  uptodate,lru,mmap
0x0001000000000828              43        0  ___U_l_____M_________________I___  uptodate,lru,mmap,readahead
0x000000000000082c             382        1  __RU_l_____M_____________________  referenced,uptodate,lru,mmap
0x000100000000082c              12        0  __RU_l_____M_________________I___  referenced,uptodate,lru,mmap,readahead
0x0000000000000868             192        0  ___U_lA____M_____________________  uptodate,lru,active,mmap
0x0001000000000868              12        0  ___U_lA____M_________________I___  uptodate,lru,active,mmap,readahead
0x000000000000086c             800        3  __RU_lA____M_____________________  referenced,uptodate,lru,active,mmap
0x000100000000086c              31        0  __RU_lA____M_________________I___  referenced,uptodate,lru,active,mmap,readahead
0x0000000000004878               2        0  ___UDlA____M__b__________________  uptodate,dirty,lru,active,mmap,swapbacked
0x0000000000001000             492        1  ____________a____________________  anonymous
0x0000000000005008               2        0  ___U________a_b__________________  uptodate,anonymous,swapbacked
0x0000000000005808               4        0  ___U_______Ma_b__________________  uptodate,mmap,anonymous,swapbacked
0x000000000000580c               1        0  __RU_______Ma_b__________________  referenced,uptodate,mmap,anonymous,swapbacked
0x0000000000005868            2839       11  ___U_lA____Ma_b__________________  uptodate,lru,active,mmap,anonymous,swapbacked
0x000000000000586c              29        0  __RU_lA____Ma_b__________________  referenced,uptodate,lru,active,mmap,anonymous,swapbacked
             total          513968     2007

# ./page-types --raw --list --no-summary --bits reserved
offset  count   flags
0       15      _____________________r___________
31      4       _____________________r___________
159     97      _____________________r___________
4096    2067    _____________________r___________
6752    2390    _____________________r___________
9355    3       _____________________r___________
9728    14526   _____________________r___________

This patch:

Introduce PageHuge(), which identifies huge/gigantic pages by their
dedicated compound destructor functions.

Also move prep_compound_gigantic_page() to hugetlb.c and make
__free_pages_ok() non-static.
Signed-off-by: NWu Fengguang <fengguang.wu@intel.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

send_sigio_to_task() reads fown->signum several times, we can race with
F_SETSIG which changes ->signum lockless.  In theory, this can fool
security checks or we can call group_send_sig_info() with the wrong
->si_signo which does not match "int sig".

Change the code to cache ->signum.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Shift current_cred() from __f_setown() to f_modown(). This reduces
the number of arguments and saves 48 bytes from fs/fcntl.o.

[ Note: this doesn't clear euid/uid when pid is set to NULL.  But if
  f_owner.pid == NULL we never use f_owner.uid/euid.  Otherwise we'd
  have a bug anyway: we must not send signals if pid was reset to NULL.  ]
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Acked-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit fec1878f caused a regression in
which contiguous blocks being allocated to the end of an extent were
getting a new extent created.  This typically results in files entirely
made up of 1-block extents even though the blocks are contiguous on
disk.

Apparently grub doesn't handle a jfs file being fragmented into too many
extents, since it refuses to boot a kernel from jfs that was created by
the 2.6.30 kernel.
Signed-off-by: NDave Kleikamp <shaggy@linux.vnet.ibm.com>
Reported-by: NAlex <alevkovich@tut.by>

When porting blktrace to tracepoints, we changed to trace/block.h
for trace prober declarations.
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

btrfs assigns this bdi to all inodes on that file system, so make
sure it's registered. This isn't really important now, but will be
when we put dirty inodes there. Even now, we miss the stats when the
bdi isn't visible.

Also fixes failure to check bdi_init() return value, and bad inherit of
->capabilities flags from the default bdi.
Acked-by: NChris Mason <chris.mason@oracle.com>
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

This patch (as1239) updates the kernel's treatment of Unicode.  The
character-set conversion routines are well behind the current state of
the Unicode specification: They don't recognize the existence of code
points beyond plane 0 or of surrogate pairs in the UTF-16 encoding.

The old wchar_t 16-bit type is retained because it's still used in
lots of places.  This shouldn't cause any new problems; if a
conversion now results in an invalid 16-bit code then before it must
have yielded an undefined code.

Difficult-to-read names like "utf_mbstowcs" are replaced with more
transparent names like "utf8s_to_utf16s" and the ordering of the
parameters is rationalized (buffer lengths come immediate after the
pointers they refer to, and the inputs precede the outputs).
Fortunately the low-level conversion routines are used in only a few
places; the interfaces to the higher-level uni2char and char2uni
methods have been left unchanged.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Acked-by: NClemens Ladisch <clemens@ladisch.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

utf8_wcstombs forgot to include one-byte UTF-8 characters when
calculating the output buffer size, i.e., theoretically, it was possible
to overflow the output buffer with an input string that contains enough
ASCII characters.

In practice, this was no problem because the only user so far (VFAT)
always uses a big enough output buffer.
Signed-off-by: NClemens Ladisch <clemens@ladisch.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

When utf8_wcstombs encounters a character that cannot be encoded, we
must not decrease the remaining output buffer size because nothing has
been written to the output buffer.
Signed-off-by: NClemens Ladisch <clemens@ladisch.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

In many SoC implementations there are hardware registers can be read or
write only.  This extends the debugfs to enforce the file permissions for
these types of registers by providing a set of fops which are read or
write only.  This assumes that the kernel developer knows more about the
hardware than the user (even root users) -- which is normally true.
Signed-off-by: NRobin Getz <rgetz@blackfin.uclinux.org>
Signed-off-by: NMike Frysinger <vapier@gentoo.org>
Signed-off-by: NBryan Wu <cooloney@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Fix an error in debugfs_create_blob's docbook description

It cannot actually be used to write a binary blob.
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

debugfs: dont stop on first failed recursive delete

While running a while loop of removing a module that removes a debugfs
directory with debugfs_remove_recursive, and at the same time doing a
while loop of cat of a file in that directory, I would hit a point where
somehow the cat of the file caused the remove to fail.

The result is that other files did not get removed when the module
was removed. I simple read of one of those file can oops the kernel
because the operations to the file no longer exist (removed by module).

The funny thing is that the file being cat'ed was removed. It was
the siblings that were not. I see in the code to debugfs_remove_recursive
there's a test that checks if the child fails to bail out of the loop
to prevent an infinite loop.

What this patch does is to still try any siblings in that directory.
If all the siblings fail, or there are no more siblings, then we exit
the loop.

This fixes the above symptom, but...

This is no full proof. It makes the debugfs_remove_recursive a bit more
robust, but it does not explain why the one file failed. There may
be some kind of delay deletion that makes the debugfs think it did
not succeed. So this patch is more of a fix for the symptom but not
the disease.

This patch still makes the debugfs_remove_recursive more robust and
until I can find out why the bug exists, this patch will keep
the kernel from oopsing in most cases.  Even after the cause is found
I think this change can stand on its own and should be kept.

[ Impact: prevent kernel oops on module unload and reading debugfs files ]
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

There is the possiblity of a memory leak if a page is allocated and if
sysfs_getlink() fails in the sysfs_follow_link.
Signed-off-by: NArmin Kuster <akuster@mvista.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

commit_fs_roots skips updating root items for fs trees that aren't modified.
This is unsafe now that relocation code modifies root item's last_snapshot
field without modifying corresponding fs tree.
Signed-off-by: NYan Zheng <zheng.yan@oracle.com>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

Replace wait_event_interruptible() with wait_event() in o2net_send_message_vec().
This is because this function is called by the dlm that expects signals to be
blocked.

Fixes oss bugzilla#1126
http://oss.oracle.com/bugzilla/show_bug.cgi?id=1126Signed-off-by: NSunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

In ocfs2_add_branch, we use the rightmost rec of the leaf extent block
to generate the e_cpos for the newly added branch. In the most case, it
is OK but if the parent extent block's rightmost rec covers more clusters
than the leaf does, it will cause kernel panic if we insert some clusters
in it. The message is something like:
(7445,1):ocfs2_insert_at_leaf:3775 ERROR: bug expression:
le16_to_cpu(el->l_next_free_rec) >= le16_to_cpu(el->l_count)
(7445,1):ocfs2_insert_at_leaf:3775 ERROR: inode 66053, depth 0, count 28,
next free 28, rec.cpos 270, rec.clusters 1, insert.cpos 275, insert.clusters 1
 [<fa7ad565>] ? ocfs2_do_insert_extent+0xb58/0xda0 [ocfs2]
 [<fa7b08f2>] ? ocfs2_insert_extent+0x5bd/0x6ba [ocfs2]
 [<fa7b1b8b>] ? ocfs2_add_clusters_in_btree+0x37f/0x564 [ocfs2]
...

The panic can be easily reproduced by the following small test case
(with bs=512, cs=4K, and I remove all the error handling so that it looks
clear enough for reading).

int main(int argc, char **argv)
{
	int fd, i;
	char buf[5] = "test";

	fd = open(argv[1], O_RDWR|O_CREAT);

	for (i = 0; i < 30; i++) {
		lseek(fd, 40960 * i, SEEK_SET);
		write(fd, buf, 5);
	}

	ftruncate(fd, 1146880);

	lseek(fd, 1126400, SEEK_SET);
	write(fd, buf, 5);

	close(fd);

	return 0;
}

The reason of the panic is that:
the 30 writes and the ftruncate makes the file's extent list looks like:

	Tree Depth: 1   Count: 19   Next Free Rec: 1
	## Offset        Clusters       Block#
	0  0             280            86183
	SubAlloc Bit: 7   SubAlloc Slot: 0
	Blknum: 86183   Next Leaf: 0
	CRC32: 00000000   ECC: 0000
	Tree Depth: 0   Count: 28   Next Free Rec: 28
	## Offset        Clusters       Block#          Flags
	0  0             1              143368          0x0
	1  10            1              143376          0x0
	...
	26 260           1              143576          0x0
	27 270           1              143584          0x0

Now another write at 1126400(275 cluster) whiich will write at the gap
between 271 and 280 will trigger ocfs2_add_branch, but the result after
the function looks like:
	Tree Depth: 1   Count: 19   Next Free Rec: 2
	## Offset        Clusters       Block#
	0  0             280            86183
	1  271           0             143592
So the extent record is intersected and make the following operation bug out.

This patch just try to remove the gap before we add the new branch, so that
the root(branch) rightmost rec will cover the same right position. So in the
above case, before adding branch the tree will be changed to
	Tree Depth: 1   Count: 19   Next Free Rec: 1
	## Offset        Clusters       Block#
	0  0             271            86183
	SubAlloc Bit: 7   SubAlloc Slot: 0
	Blknum: 86183   Next Leaf: 0
	CRC32: 00000000   ECC: 0000
	Tree Depth: 0   Count: 28   Next Free Rec: 28
	## Offset        Clusters       Block#          Flags
	0  0             1              143368          0x0
	1  10            1              143376          0x0
	...
	26 260           1              143576          0x0
	27 270           1              143584          0x0
And after branch add, the tree looks like
	Tree Depth: 1   Count: 19   Next Free Rec: 2
	## Offset        Clusters       Block#
	0  0             271            86183
	1  271           0             143592
Signed-off-by: NTao Ma <tao.ma@oracle.com>
Acked-by: NMark Fasheh <mfasheh@suse.com>
Signed-off-by: NJoel Becker <joel.becker@oracle.com>

On systems where CONFIG_SHMEM is disabled, mounting tmpfs filesystems can
fail when tmpfs options are used.  This is because tmpfs creates a small
wrapper around ramfs which rejects unknown options, and ramfs itself only
supports a tiny subset of what tmpfs supports.  This makes it pretty hard
to use the same userspace systems across different configuration systems.
As such, ramfs should ignore the tmpfs options when tmpfs is merely a
wrapper around ramfs.

This used to work before commit c3b1b1cb as previously, ramfs would
ignore all options.  But now, we get:
ramfs: bad mount option: size=10M
mount: mounting mdev on /dev failed: Invalid argument

Another option might be to restore the previous behavior, where ramfs
simply ignored all unknown mount options ... which is what Hugh prefers.
Signed-off-by: NMike Frysinger <vapier@gentoo.org>
Signed-off-by: NHugh Dickins <hugh.dickins@tiscali.co.uk>
Acked-by: NMatt Mackall <mpm@selenic.com>
Acked-by: NWu Fengguang <fengguang.wu@intel.com>
Cc: stable@kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Identation got messed up when merging the current_umask changes with
the generic ACL support.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NFelix Blyakher <felixb@sgi.com>
Signed-off-by: NFelix Blyakher <felixb@sgi.com>

Fix warnings about unitialized dquot variables by making sure
xfs_qm_vop_dqalloc touches it even when quotas are disabled.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NFelix Blyakher <felixb@sgi.com>
Signed-off-by: NFelix Blyakher <felixb@sgi.com>

Fix typo in bio_alloc kernel doc.
Signed-off-by: NNikanth Karthikesan <knikanth@suse.de>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Signed-off-by: NJiri Kosina <jkosina@suse.cz>

The advertised flag for not updating the time was wrong.
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Fix a typo in fs/compat.c
Signed-off-by: NNikanth Karthikesan <knikanth@suse.de>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Signed-off-by: NAli Gholami Rudi <ali@rudi.ir>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Regression from commit 28e21170.
Need to free temporary buffer allocated in xfs_getbmap().
Signed-off-by: NFelix Blyakher <felixb@sgi.com>
Signed-off-by: NHedi Berriche <hedi@sgi.com>
Reported-by: NJustin Piszcz <jpiszcz@lucidpixels.com>
Reviewed-by: NEric Sandeen <sandeen@sandeen.net>
Reviewed-by: NChristoph Hellwig <hch@lst.de>