Cosmetic. This doesn't really matter because a) device->mutex is
the only user of __lockdep_no_validate__ and b) this class should
be never reported as the source of problem, but if something goes
wrong "&dev->mutex" looks better than "&__lockdep_no_validate__"
as the name of the lock.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140120182016.GA26512@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

The "int check" argument of lock_acquire() and held_lock->check are
misleading. This is actually a boolean: 2 means "true", everything
else is "false".

And there is no need to pass 1 or 0 to lock_acquire() depending on
CONFIG_PROVE_LOCKING, __lock_acquire() checks prove_locking at the
start and clears "check" if !CONFIG_PROVE_LOCKING.

Note: probably we can simply kill this member/arg. The only explicit
user of check => 0 is rcu_lock_acquire(), perhaps we can change it to
use lock_acquire(trylock =>, read => 2). __lockdep_no_validate means
check => 0 implicitly, but we can change validate_chain() to check
hlock->instance->key instead. Not to mention it would be nice to get
rid of lockdep_set_novalidate_class().
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140120182006.GA26495@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

This patch allows each architecture to add its specific assembly optimized
arch_mcs_spin_lock_contended and arch_mcs_spinlock_uncontended for
MCS lock and unlock functions.
Signed-off-by: NTim Chen <tim.c.chen@linux.intel.com>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: AswinChandramouleeswaran <aswin@hp.com>
Cc: George Spelvin <linux@horizon.com>
Cc: Rik vanRiel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: MichelLespinasse <walken@google.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Alex Shi <alex.shi@linaro.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Figo.zhang" <figo1802@gmail.com>
Cc: "Paul E.McKenney" <paulmck@linux.vnet.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Waiman Long <waiman.long@hp.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew R Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1390347382.3138.67.camel@schen9-DESKSigned-off-by: NIngo Molnar <mingo@kernel.org>

This warning seems to show up a lot now, since ___wait_event()
is (indirectly) used inside wait_event_timeout(), which also
has a variable called __ret. Rename the one in ___wait_event()
to ___ret (another leading underscore) to suppress the warning.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/1391704121.12789.20.camel@jlt4.sipsolutions.netSigned-off-by: NIngo Molnar <mingo@kernel.org>

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

Add my copyright to the zsmalloc source code which I maintain.
Signed-off-by: NMinchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch moves zsmalloc under mm directory.

Before that, description will explain why we have needed custom
allocator.

Zsmalloc is a new slab-based memory allocator for storing compressed
pages.  It is designed for low fragmentation and high allocation success
rate on large object, but <= PAGE_SIZE allocations.

zsmalloc differs from the kernel slab allocator in two primary ways to
achieve these design goals.

zsmalloc never requires high order page allocations to back slabs, or
"size classes" in zsmalloc terms.  Instead it allows multiple
single-order pages to be stitched together into a "zspage" which backs
the slab.  This allows for higher allocation success rate under memory
pressure.

Also, zsmalloc allows objects to span page boundaries within the zspage.
This allows for lower fragmentation than could be had with the kernel
slab allocator for objects between PAGE_SIZE/2 and PAGE_SIZE.  With the
kernel slab allocator, if a page compresses to 60% of it original size,
the memory savings gained through compression is lost in fragmentation
because another object of the same size can't be stored in the leftover
space.

This ability to span pages results in zsmalloc allocations not being
directly addressable by the user.  The user is given an
non-dereferencable handle in response to an allocation request.  That
handle must be mapped, using zs_map_object(), which returns a pointer to
the mapped region that can be used.  The mapping is necessary since the
object data may reside in two different noncontigious pages.

The zsmalloc fulfills the allocation needs for zram perfectly

[sjenning@linux.vnet.ibm.com: borrow Seth's quote]
Signed-off-by: NMinchan Kim <minchan@kernel.org>
Acked-by: NNitin Gupta <ngupta@vflare.org>
Reviewed-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Bob Liu <bob.liu@oracle.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Luigi Semenzato <semenzato@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Seth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Make smp_call_function_single and friends more efficient by using a
lockless list.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Now we have memblock_virt_alloc_low to replace original bootmem api in
swiotlb.

But we should not use BOOTMEM_LOW_LIMIT for arch that does not support
CONFIG_NOBOOTMEM, as old api take 0.

| #define alloc_bootmem_low(x) \
|        __alloc_bootmem_low(x, SMP_CACHE_BYTES, 0)
|#define alloc_bootmem_low_pages_nopanic(x) \
|        __alloc_bootmem_low_nopanic(x, PAGE_SIZE, 0)

and we have
 #define BOOTMEM_LOW_LIMIT __pa(MAX_DMA_ADDRESS)
for CONFIG_NOBOOTMEM.

Restore goal to 0 to fix ia64 crash, that Tony found.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Reported-by: NTony Luck <tony.luck@gmail.com>
Tested-by: NTony Luck <tony.luck@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit d5dc77bf ("consolidate compat lookup_dcookie()") coverted all
architectures to the new compat_sys_lookup_dcookie() syscall.

The "len" paramater of the new compat syscall must have the type
compat_size_t in order to enforce zero extension for architectures where
the ABI requires that the caller of a function performed zero and/or
sign extension to 64 bit of all parameters.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: <stable@vger.kernel.org>	[v3.10+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We got a report that the pwritev syscall does not work correctly in
compat mode on s390.

It turned out that with commit 72ec3516 ("switch compat readv/writev
variants to COMPAT_SYSCALL_DEFINE") we lost the zero extension of a
couple of syscall parameters because the some parameter types haven't
been converted from unsigned long to compat_ulong_t.

This is needed for architectures where the ABI requires that the caller
of a function performed zero and/or sign extension to 64 bit of all
parameters.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: <stable@vger.kernel.org>	[v3.10+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The VM is currently heavily tuned to avoid swapping.  Whether that is
good or bad is a separate discussion, but as long as the VM won't swap
to make room for dirty cache, we can not consider anonymous pages when
calculating the amount of dirtyable memory, the baseline to which
dirty_background_ratio and dirty_ratio are applied.

A simple workload that occupies a significant size (40+%, depending on
memory layout, storage speeds etc.) of memory with anon/tmpfs pages and
uses the remainder for a streaming writer demonstrates this problem.  In
that case, the actual cache pages are a small fraction of what is
considered dirtyable overall, which results in an relatively large
portion of the cache pages to be dirtied.  As kswapd starts rotating
these, random tasks enter direct reclaim and stall on IO.

Only consider free pages and file pages dirtyable.
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Reported-by: NTejun Heo <tj@kernel.org>
Tested-by: NTejun Heo <tj@kernel.org>
Reviewed-by: NRik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Reviewed-by: NMichal Hocko <mhocko@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NJean Delvare <khali@linux-fr.org>

The event returned from fsnotify_add_notify_event() cannot ever be used
safely as the event may be freed by the time the function returns (after
dropping notification_mutex). So change the prototype to just return
whether the event was added or merged into some existing event.
Reported-and-tested-by: NJiri Kosina <jkosina@suse.cz>
Reported-and-tested-by: NDave Jones <davej@fedoraproject.org>
Signed-off-by: NJan Kara <jack@suse.cz>

Btrfs needs a simple way to know if it needs to let go of it's read lock on a
rwsem.  Introduce rwsem_is_contended to check to see if there are any waiters on
this rwsem currently.  This is just a hueristic, it is meant to be light and not
100% accurate and called by somebody already holding on to the rwsem in either
read or write.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <clm@fb.com>
Acked-by: NIngo Molnar <mingo@kernel.org>

I observed that there are for_each macros that do an extra memory access
beyond the defined area.
Normally this does not cause problems.
But, this can cause exceptions. For example: if the area is allocated at
the end of a page and the next page is not accessible.

For correctness, I suggest changing the arguments of the 'for loop' like
others 'for_each' do in the kernel.
Signed-off-by: NJose Alonso <joalonsof@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

When contended, architectures may be able to reduce the polling overhead
in ways which aren't expressible using a simple relax() primitive.

This patch allows architectures to hook into the mcs_{lock,unlock}
functions for the contended cases only.
Reviewed-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NTim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/1390347370.3138.65.camel@schen9-DESKSigned-off-by: NIngo Molnar <mingo@kernel.org>

Remove unnecessary operation to assign locked status to 1 if lock is
acquired without contention. Lock status will not be checked by lock
holder again once it is acquired and any lock
contenders will not be looking at the lock holder's lock status.

Make the cmpxchg(lock, node, NULL) == node check in mcs_spin_unlock()
likely() as it is likely that a race did not occur most of the time.

Also add in more comments describing how the local node is used in MCS locks.
Reviewed-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: NTim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: NJason Low <jason.low2@hp.com>
Signed-off-by: NTim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/1390347365.3138.64.camel@schen9-DESKSigned-off-by: NIngo Molnar <mingo@kernel.org>

We will need the MCS lock code for doing optimistic spinning for rwsem
and queued rwlock.  Extracting the MCS code from mutex.c and put into
its own file allow us to reuse this code easily.

We also inline mcs_spin_lock and mcs_spin_unlock functions
for better efficiency.

Note that using the smp_load_acquire/smp_store_release pair used in
mcs_lock and mcs_unlock is not sufficient to form a full memory barrier
across cpus for many architectures (except x86).  For applications that
absolutely need a full barrier across multiple cpus with mcs_unlock and
mcs_lock pair, smp_mb__after_unlock_lock() should be used after mcs_lock.
Reviewed-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: NTim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: NDavidlohr Bueso <davidlohr@hp.com>
Signed-off-by: NPeter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1390347360.3138.63.camel@schen9-DESKSigned-off-by: NIngo Molnar <mingo@kernel.org>

Reduce data size a little.
Reduce checkpatch noise.

$ size kernel/softirq.o*
   text	   data	    bss	    dec	    hex	filename
  11554	   6013	   4008	  21575	   5447	kernel/softirq.o.new
  11474	   6093	   4008	  21575	   5447	kernel/softirq.o.old
Signed-off-by: NJoe Perches <joe@perches.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

@splice_desc.total_len is 32 bit(unsigned int) which is used to store the
size passed from userspace which is 64 bit(size_t) so that the size is
unexpectedly truncated

That means vmsplice can not work if the size passed from userspace is >=
4G, for example, we noticed in vmsplice, splice-reader does not do
anything and splice-writer is waiting for available buffer forever if the
size is 4G

Fix it by extending @splice_desc.total_len to 64 bits as well
Signed-off-by: NXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This field is only used to reset the ids seq number if it exceeds the
smaller of INT_MAX/SEQ_MULTIPLIER and USHRT_MAX, and can therefore be
moved out of the structure and into its own macro.  Since each
ipc_namespace contains a table of 3 pointers to struct ipc_ids we can
save space in instruction text:

   text    data     bss     dec     hex filename
  56232    2348      24   58604    e4ec ipc/built-in.o
  56216    2348      24   58588    e4dc ipc/built-in.o-after
Signed-off-by: NDavidlohr Bueso <davidlohr@hp.com>
Reviewed-by: NJonathan Gonzalez <jgonzalez@linets.cl>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Cc: Rik van Riel <riel@redhat.com>
Acked-by: NManfred Spraul <manfred@colorfullife.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The ipc code does not adhere the typical linux coding style.
This patch fixes lots of simple whitespace errors.

- mostly autogenerated by
  scripts/checkpatch.pl -f --fix \
	--types=pointer_location,spacing,space_before_tab
- one manual fixup (keep structure members tab-aligned)
- removal of additional space_before_tab that were not found by --fix

Tested with some of my msg and sem test apps.

Andrew: Could you include it in -mm and move it towards Linus' tree?
Signed-off-by: NManfred Spraul <manfred@colorfullife.com>
Suggested-by: NLi Bin <huawei.libin@huawei.com>
Cc: Joe Perches <joe@perches.com>
Acked-by: NRafael Aquini <aquini@redhat.com>
Cc: Davidlohr Bueso <davidlohr@hp.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

struct kern_ipc_perm.deleted is meant to be used as a boolean toggle, and
the changes introduced by this patch are just to make the case explicit.
Signed-off-by: NRafael Aquini <aquini@redhat.com>
Reviewed-by: NRik van Riel <riel@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Acked-by: NDavidlohr Bueso <davidlohr@hp.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The new memblock_virt APIs are used to replaced old bootmem API.

We need to allocate page below 4G for swiotlb.

That should fix regression on Andrew's system that is using swiotlb.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit c02cecb9 ("ARM: orion: move platform_data definitions")
moved the files to the current location but forgot to remove the pointer
to its previous location. Clean it up. While at it also change the header
file protection macros appropriately.
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: NBryan Wu <cooloney@gmail.com>

LED platform data are overwhelmed by excessive field "max_cur"
which just replicates few bits of "led_control" field.
This patch removes this field and adds a definition for the
current settings in the header.
Signed-off-by: NAlexander Shiyan <shc_work@mail.ru>
Signed-off-by: NBryan Wu <cooloney@gmail.com>

Announce our (limited, see previous commit) support for CACHEPOOL
feature.
Signed-off-by: NIlya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: NSage Weil <sage@inktank.com>

Follow redirect replies from osds, for details see ceph.git commit
fbbe3ad1220799b7bb00ea30fce581c5eadaf034.

v1 (current) version of redirect reply consists of oloc and oid, which
expands to pool, key, nspace, hash and oid.  However, server-side code
that would populate anything other than pool doesn't exist yet, and
hence this commit adds support for pool redirects only.  To make sure
that future server-side updates don't break us, we decode all fields
and, if any of key, nspace, hash or oid have a non-default value, error
out with "corrupt osd_op_reply ..." message.
Signed-off-by: NIlya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: NSage Weil <sage@inktank.com>

Rename ceph_osd_request::r_{oloc,oid} to r_base_{oloc,oid} before
introducing r_target_{oloc,oid} needed for redirects.
Signed-off-by: NIlya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: NSage Weil <sage@inktank.com>

Overwrite ceph_osd_request::r_oloc.pool with read_tier for read ops and
write_tier for write and read+write ops (aka basic tiering support).
{read,write}_tier are part of pg_pool_t since v9.  This commit bumps
our pg_pool_t decode compat version from v7 to v9, all new fields
except for {read,write}_tier are ignored.
Signed-off-by: NIlya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: NSage Weil <sage@inktank.com>

"Lookup pool info by ID" function is hidden in osdmap.c.  Expose it to
the rest of libceph.
Signed-off-by: NIlya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: NSage Weil <sage@inktank.com>

Update CEPH_OSD_FLAG_* enum.  (We need CEPH_OSD_FLAG_IGNORE_OVERLAY to
support tiering).
Signed-off-by: NIlya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: NSage Weil <sage@inktank.com>

Switch ceph_calc_ceph_pg() to new oloc and oid abstractions and rename
it to ceph_oloc_oid_to_pg() to make its purpose more clear.
Signed-off-by: NIlya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: NSage Weil <sage@inktank.com>

In preparation for tiering support, which would require having two
(base and target) object names for each osd request and also copying
those names around, introduce struct ceph_object_id (oid) and a couple
helpers to facilitate those copies and encapsulate the fact that object
name is not necessarily a NUL-terminated string.
Signed-off-by: NIlya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: NSage Weil <sage@inktank.com>

In preparation for adding oid abstraction, rename MAX_OBJ_NAME_SIZE to
CEPH_MAX_OID_NAME_LEN.
Signed-off-by: NIlya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: NSage Weil <sage@inktank.com>

Move ceph_file_layout helper macros and inline functions to ceph_fs.h.
Signed-off-by: NIlya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: NSage Weil <sage@inktank.com>

Instead of relying on pool fields in ceph_file_layout (for mapping) and
ceph_pg (for enconding), start using ceph_object_locator (oloc)
abstraction.  Note that userspace oloc currently consists of pool, key,
nspace and hash fields, while this one contains only a pool.  This is
OK, because at this point we only send (i.e. encode) olocs and never
have to receive (i.e. decode) them.

This makes keeping a copy of ceph_file_layout in every osd request
unnecessary, so ceph_osd_request::r_file_layout field is nuked.
Signed-off-by: NIlya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: NSage Weil <sage@inktank.com>

For some assemblers, they use another character as newline in a macro
(e.g. arc uses '`'), so for generic assembly code, need use ASM_NL (a
macro) instead of ';' for it.
Signed-off-by: NChen Gang <gang.chen.5i5j@gmail.com>
Acked-by: NVineet Gupta <vgupta@synopsys.com>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

There is a possible race in how the nfs_invalidate_mapping function is
handled.  Currently, we go and invalidate the pages in the file and then
clear NFS_INO_INVALID_DATA.

The problem is that it's possible for a stale page to creep into the
mapping after the page was invalidated (i.e., via readahead). If another
writer comes along and sets the flag after that happens but before
invalidate_inode_pages2 returns then we could clear the flag
without the cache having been properly invalidated.

So, we must clear the flag first and then invalidate the pages. Doing
this however, opens another race:

It's possible to have two concurrent read() calls that end up in
nfs_revalidate_mapping at the same time. The first one clears the
NFS_INO_INVALID_DATA flag and then goes to call nfs_invalidate_mapping.

Just before calling that though, the other task races in, checks the
flag and finds it cleared. At that point, it trusts that the mapping is
good and gets the lock on the page, allowing the read() to be satisfied
from the cache even though the data is no longer valid.

These effects are easily manifested by running diotest3 from the LTP
test suite on NFS. That program does a series of DIO writes and buffered
reads. The operations are serialized and page-aligned but the existing
code fails the test since it occasionally allows a read to come out of
the cache incorrectly. While mixing direct and buffered I/O isn't
recommended, I believe it's possible to hit this in other ways that just
use buffered I/O, though that situation is much harder to reproduce.

The problem is that the checking/clearing of that flag and the
invalidation of the mapping really need to be atomic. Fix this by
serializing concurrent invalidations with a bitlock.

At the same time, we also need to allow other places that check
NFS_INO_INVALID_DATA to check whether we might be in the middle of
invalidating the file, so fix up a couple of places that do that
to look for the new NFS_INO_INVALIDATING flag.

Doing this requires us to be careful not to set the bitlock
unnecessarily, so this code only does that if it believes it will
be doing an invalidation.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>