Commit Graph

494086 Commits

Author SHA1 Message Date
Pavel Emelyanov
e4a0d3e720 aio: Make it possible to remap aio ring
There are actually two issues this patch addresses. Let me start with
the one I tried to solve in the beginning.

So, in the checkpoint-restore project (criu) we try to dump tasks'
state and restore one back exactly as it was. One of the tasks' state
bits is rings set up with io_setup() call. There's (almost) no problems
in dumping them, there's a problem restoring them -- if I dump a task
with aio ring originally mapped at address A, I want to restore one
back at exactly the same address A. Unfortunately, the io_setup() does
not allow for that -- it mmaps the ring at whatever place mm finds
appropriate (it calls do_mmap_pgoff() with zero address and without
the MAP_FIXED flag).

To make restore possible I'm going to mremap() the freshly created ring
into the address A (under which it was seen before dump). The problem is
that the ring's virtual address is passed back to the user-space as the
context ID and this ID is then used as search key by all the other io_foo()
calls. Reworking this ID to be just some integer doesn't seem to work, as
this value is already used by libaio as a pointer using which this library
accesses memory for aio meta-data.

So, to make restore work we need to make sure that

a) ring is mapped at desired virtual address
b) kioctx->user_id matches this value

Having said that, the patch makes mremap() on aio region update the
kioctx's user_id and mmap_base values.

Here appears the 2nd issue I mentioned in the beginning of this mail.
If (regardless of the C/R dances I do) someone creates an io context
with io_setup(), then mremap()-s the ring and then destroys the context,
the kill_ioctx() routine will call munmap() on wrong (old) address.
This will result in a) aio ring remaining in memory and b) some other
vma get unexpectedly unmapped.

What do you think?

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
2014-12-13 17:49:50 -05:00
Linus Torvalds
9ea18f8cab Merge branch 'for-3.19/drivers' of git://git.kernel.dk/linux-block
Pull block layer driver updates from Jens Axboe:

 - NVMe updates:
        - The blk-mq conversion from Matias (and others)

        - A stack of NVMe bug fixes from the nvme tree, mostly from Keith.

        - Various bug fixes from me, fixing issues in both the blk-mq
          conversion and generic bugs.

        - Abort and CPU online fix from Sam.

        - Hot add/remove fix from Indraneel.

 - A couple of drbd fixes from the drbd team (Andreas, Lars, Philipp)

 - With the generic IO stat accounting from 3.19/core, converting md,
   bcache, and rsxx to use those.  From Gu Zheng.

 - Boundary check for queue/irq mode for null_blk from Matias.  Fixes
   cases where invalid values could be given, causing the device to hang.

 - The xen blkfront pull request, with two bug fixes from Vitaly.

* 'for-3.19/drivers' of git://git.kernel.dk/linux-block: (56 commits)
  NVMe: fix race condition in nvme_submit_sync_cmd()
  NVMe: fix retry/error logic in nvme_queue_rq()
  NVMe: Fix FS mount issue (hot-remove followed by hot-add)
  NVMe: fix error return checking from blk_mq_alloc_request()
  NVMe: fix freeing of wrong request in abort path
  xen/blkfront: remove redundant flush_op
  xen/blkfront: improve protection against issuing unsupported REQ_FUA
  NVMe: Fix command setup on IO retry
  null_blk: boundary check queue_mode and irqmode
  block/rsxx: use generic io stats accounting functions to simplify io stat accounting
  md: use generic io stats accounting functions to simplify io stat accounting
  drbd: use generic io stats accounting functions to simplify io stat accounting
  md/bcache: use generic io stats accounting functions to simplify io stat accounting
  NVMe: Update module version major number
  NVMe: fail pci initialization if the device doesn't have any BARs
  NVMe: add ->exit_hctx() hook
  NVMe: make setup work for devices that don't do INTx
  NVMe: enable IO stats by default
  NVMe: nvme_submit_async_admin_req() must use atomic rq allocation
  NVMe: replace blk_put_request() with blk_mq_free_request()
  ...
2014-12-13 14:22:26 -08:00
Linus Torvalds
caf292ae5b Merge branch 'for-3.19/core' of git://git.kernel.dk/linux-block
Pull block driver core update from Jens Axboe:
 "This is the pull request for the core block IO changes for 3.19.  Not
  a huge round this time, mostly lots of little good fixes:

   - Fix a bug in sysfs blktrace interface causing a NULL pointer
     dereference, when enabled/disabled through that API.  From Arianna
     Avanzini.

   - Various updates/fixes/improvements for blk-mq:

        - A set of updates from Bart, mostly fixing buts in the tag
          handling.

        - Cleanup/code consolidation from Christoph.

        - Extend queue_rq API to be able to handle batching issues of IO
          requests. NVMe will utilize this shortly. From me.

        - A few tag and request handling updates from me.

        - Cleanup of the preempt handling for running queues from Paolo.

        - Prevent running of unmapped hardware queues from Ming Lei.

        - Move the kdump memory limiting check to be in the correct
          location, from Shaohua.

        - Initialize all software queues at init time from Takashi. This
          prevents a kobject warning when CPUs are brought online that
          weren't online when a queue was registered.

   - Single writeback fix for I_DIRTY clearing from Tejun.  Queued with
     the core IO changes, since it's just a single fix.

   - Version X of the __bio_add_page() segment addition retry from
     Maurizio.  Hope the Xth time is the charm.

   - Documentation fixup for IO scheduler merging from Jan.

   - Introduce (and use) generic IO stat accounting helpers for non-rq
     drivers, from Gu Zheng.

   - Kill off artificial limiting of max sectors in a request from
     Christoph"

* 'for-3.19/core' of git://git.kernel.dk/linux-block: (26 commits)
  bio: modify __bio_add_page() to accept pages that don't start a new segment
  blk-mq: Fix uninitialized kobject at CPU hotplugging
  blktrace: don't let the sysfs interface remove trace from running list
  blk-mq: Use all available hardware queues
  blk-mq: Micro-optimize bt_get()
  blk-mq: Fix a race between bt_clear_tag() and bt_get()
  blk-mq: Avoid that __bt_get_word() wraps multiple times
  blk-mq: Fix a use-after-free
  blk-mq: prevent unmapped hw queue from being scheduled
  blk-mq: re-check for available tags after running the hardware queue
  blk-mq: fix hang in bt_get()
  blk-mq: move the kdump check to blk_mq_alloc_tag_set
  blk-mq: cleanup tag free handling
  blk-mq: use 'nr_cpu_ids' as highest CPU ID count for hwq <-> cpu map
  blk: introduce generic io stat accounting help function
  blk-mq: handle the single queue case in blk_mq_hctx_next_cpu
  genhd: check for int overflow in disk_expand_part_tbl()
  blk-mq: add blk_mq_free_hctx_request()
  blk-mq: export blk_mq_free_request()
  blk-mq: use get_cpu/put_cpu instead of preempt_disable/preempt_enable
  ...
2014-12-13 14:14:23 -08:00
Linus Torvalds
8f4385d590 This code is a fork from the trace-3.19 pull as it needed the trace_seq
clean ups from that branch.
 
 This code solves the issue of performing stack dumps from NMI context.
 The issue is that printk() is not safe from NMI context as if the NMI
 were to trigger when a printk() was being performed, the NMI could
 deadlock from the printk() internal locks. This has been seen in practice.
 
 With lots of review from Petr Mladek, this code went through several
 iterations, and we feel that it is now at a point of quality to be
 accepted into mainline.
 
 Here's what is contained in this patch set:
 
  o Creates a "seq_buf" generic buffer utility that allows a descriptor
    to be passed around where functions can write their own "printk()"
    formatted strings into it. The generic version was pulled out of
    the trace_seq() code that was made specifically for tracing.
 
  o The seq_buf code was change to model the seq_file code. I have
    a patch (not included for 3.19) that converts the seq_file.c code
    over to use seq_buf.c like the trace_seq.c code does. This was done
    to make sure that seq_buf.c is compatible with seq_file.c. I may
    try to get that patch in for 3.20.
 
  o The seq_buf.c file was moved to lib/ to remove it from being dependent
    on CONFIG_TRACING.
 
  o The printk() was updated to allow for a per_cpu "override" of
    the internal calls. That is, instead of writing to the console, a call
    to printk() may do something else. This made it easier to allow the
    NMI to change what printk() does in order to call dump_stack() without
    needing to update that code as well.
 
  o Finally, the dump_stack from all CPUs via NMI code was converted to
    use the seq_buf code. The caller to trigger the NMI code would wait
    till all the NMIs finished, and then it would print the seq_buf
    data to the console safely from a non NMI context.
 
 [ Updated to remove unnecessary preempt_disable in printk() ]
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Merge tag 'trace-seq-buf-3.19-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixlet from Steven Rostedt:
 "Remove unnecessary preempt_disable in printk()"

* tag 'trace-seq-buf-3.19-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  printk: Do not disable preemption for accessing printk_func
2014-12-13 14:04:41 -08:00
Linus Torvalds
52bb452558 Here's two fixes:
1) Discovered by Fengguang Wu's tests. I changed the parameters to
    the function graph x86 prepare_ftrace_return call but forgot
    to update the call from entry_32 (i386 version). This patch corrects
    that.
 
 2) I was tracing some code and found that the sched_switch tracepoint
    was showing tasks in the INTERRUPTIBLE state as RUNNING. This was
    due to the updates to convert preempt_count into a per_cpu variable.
    The tracepoint logic was made to use the tasks saved_preempt_count
    which could hold a stale "PREEMPT_ACTIVE", instead of using the
    current preempt_count() call.
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Merge tag 'trace-fixes-v3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Here's two fixes:

  1) Discovered by Fengguang Wu's tests.  I changed the parameters to
     the function graph x86 prepare_ftrace_return call but forgot to
     update the call from entry_32 (i386 version).  This patch corrects
     that.

  2) I was tracing some code and found that the sched_switch tracepoint
     was showing tasks in the INTERRUPTIBLE state as RUNNING.  This was
     due to the updates to convert preempt_count into a per_cpu
     variable.  The tracepoint logic was made to use the tasks
     saved_preempt_count which could hold a stale "PREEMPT_ACTIVE",
     instead of using the current preempt_count() call"

* tag 'trace-fixes-v3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing/sched: Check preempt_count() for current when reading task->state
  ftrace/x86: Update i386 call to prepare_ftrace_return()
2014-12-13 14:01:11 -08:00
Linus Torvalds
a99abce2d9 Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit
Pull audit updates from Paul Moore:
 "Two small patches from the audit next branch; only one of which has
  any real significant code changes, the other is simply a MAINTAINERS
  update for audit.

  The single code patch is pretty small and rather straightforward, it
  changes the audit "version" number reported to userspace from an
  integer to a bitmap which is used to indicate the functionality of the
  running kernel.  This really doesn't have much impact on the kernel,
  but it will make life easier for the audit userspace folks.

  Thankfully we were still on a version number which allowed us to do
  this without breaking userspace"

* 'upstream' of git://git.infradead.org/users/pcmoore/audit:
  audit: convert status version to a feature bitmap
  audit: add Paul Moore to the MAINTAINERS entry
2014-12-13 13:41:28 -08:00
Linus Torvalds
e3aa91a7cb Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto update from Herbert Xu:
 - The crypto API is now documented :)
 - Disallow arbitrary module loading through crypto API.
 - Allow get request with empty driver name through crypto_user.
 - Allow speed testing of arbitrary hash functions.
 - Add caam support for ctr(aes), gcm(aes) and their derivatives.
 - nx now supports concurrent hashing properly.
 - Add sahara support for SHA1/256.
 - Add ARM64 version of CRC32.
 - Misc fixes.

* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (77 commits)
  crypto: tcrypt - Allow speed testing of arbitrary hash functions
  crypto: af_alg - add user space interface for AEAD
  crypto: qat - fix problem with coalescing enable logic
  crypto: sahara - add support for SHA1/256
  crypto: sahara - replace tasklets with kthread
  crypto: sahara - add support for i.MX53
  crypto: sahara - fix spinlock initialization
  crypto: arm - replace memset by memzero_explicit
  crypto: powerpc - replace memset by memzero_explicit
  crypto: sha - replace memset by memzero_explicit
  crypto: sparc - replace memset by memzero_explicit
  crypto: algif_skcipher - initialize upon init request
  crypto: algif_skcipher - removed unneeded code
  crypto: algif_skcipher - Fixed blocking recvmsg
  crypto: drbg - use memzero_explicit() for clearing sensitive data
  crypto: drbg - use MODULE_ALIAS_CRYPTO
  crypto: include crypto- module prefix in template
  crypto: user - add MODULE_ALIAS
  crypto: sha-mb - remove a bogus NULL check
  crytpo: qat - Fix 64 bytes requests
  ...
2014-12-13 13:33:26 -08:00
Linus Torvalds
78a45c6f06 Merge branch 'akpm' (second patch-bomb from Andrew)
Merge second patchbomb from Andrew Morton:
 - the rest of MM
 - misc fs fixes
 - add execveat() syscall
 - new ratelimit feature for fault-injection
 - decompressor updates
 - ipc/ updates
 - fallocate feature creep
 - fsnotify cleanups
 - a few other misc things

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (99 commits)
  cgroups: Documentation: fix trivial typos and wrong paragraph numberings
  parisc: percpu: update comments referring to __get_cpu_var
  percpu: update local_ops.txt to reflect this_cpu operations
  percpu: remove __get_cpu_var and __raw_get_cpu_var macros
  fsnotify: remove destroy_list from fsnotify_mark
  fsnotify: unify inode and mount marks handling
  fallocate: create FAN_MODIFY and IN_MODIFY events
  mm/cma: make kmemleak ignore CMA regions
  slub: fix cpuset check in get_any_partial
  slab: fix cpuset check in fallback_alloc
  shmdt: use i_size_read() instead of ->i_size
  ipc/shm.c: fix overly aggressive shmdt() when calls span multiple segments
  ipc/msg: increase MSGMNI, remove scaling
  ipc/sem.c: increase SEMMSL, SEMMNI, SEMOPM
  ipc/sem.c: change memory barrier in sem_lock() to smp_rmb()
  lib/decompress.c: consistency of compress formats for kernel image
  decompress_bunzip2: off by one in get_next_block()
  usr/Kconfig: make initrd compression algorithm selection not expert
  fault-inject: add ratelimit option
  ratelimit: add initialization macro
  ...
2014-12-13 13:00:36 -08:00
SeongJae Park
29d293b600 cgroups: Documentation: fix trivial typos and wrong paragraph numberings
Signed-off-by: SeongJae Park <sj38.park@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:53 -08:00
Christoph Lameter
6ddb798f02 parisc: percpu: update comments referring to __get_cpu_var
__get_cpu_var was removed. Update comments to refer to
this_cpu_ptr() instead.

Signed-off-by: Christoph Lameter <cl@linux.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:53 -08:00
Christoph Lameter
7d94a82e45 percpu: update local_ops.txt to reflect this_cpu operations
Update the documentation to reflect changes due to the availability of
this_cpu operations.

Signed-off-by: Christoph Lameter <cl@linux.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:53 -08:00
Christoph Lameter
6c51ec4d18 percpu: remove __get_cpu_var and __raw_get_cpu_var macros
No user is left in the kernel source tree.  Therefore we can drop the
definitions.

This is the final merge of the transition away from __get_cpu_var.  After
this patch the kernel will not build if anyone uses __get_cpu_var.

Signed-off-by: Christoph Lameter <cl@linux.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:53 -08:00
Jan Kara
37d469e767 fsnotify: remove destroy_list from fsnotify_mark
destroy_list is used to track marks which still need waiting for srcu
period end before they can be freed.  However by the time mark is added to
destroy_list it isn't in group's list of marks anymore and thus we can
reuse fsnotify_mark->g_list for queueing into destroy_list.  This saves
two pointers for each fsnotify_mark.

Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Eric Paris <eparis@redhat.com>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:53 -08:00
Jan Kara
0809ab69a2 fsnotify: unify inode and mount marks handling
There's a lot of common code in inode and mount marks handling.  Factor it
out to a common helper function.

Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Eric Paris <eparis@redhat.com>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:53 -08:00
Heinrich Schuchardt
820c12d5d6 fallocate: create FAN_MODIFY and IN_MODIFY events
The fanotify and the inotify API can be used to monitor changes of the
file system.  System call fallocate() modifies files.  Hence it should
trigger the corresponding fanotify (FAN_MODIFY) and inotify (IN_MODIFY)
events.  The most interesting case is FALLOC_FL_COLLAPSE_RANGE because
this value allows to create arbitrary file content from random data.

This patch adds the missing call to fsnotify_modify().

The FAN_MODIFY and IN_MODIFY event will be created when fallocate()
succeeds.  It will even be created if the file length remains unchanged,
e.g.  when calling fanotify with flag FALLOC_FL_KEEP_SIZE.

This logic was primarily chosen to keep the coding simple.

It resembles the logic of the write() system call.

When we call write() we always create a FAN_MODIFY event, even in the case
of overwriting with identical data.

Events FAN_MODIFY and IN_MODIFY do not provide any guarantee that data was
actually changed.

Furthermore even if if the filesize remains unchanged, fallocate() may
influence whether a subsequent write() will succeed and hence the
fallocate() call may be considered a modification.

The fallocate(2) man page teaches: After a successful call, subsequent
writes into the range specified by offset and len are guaranteed not to
fail because of lack of disk space.

So calling fallocate(fd, FALLOC_FL_KEEP_SIZE, offset, len) may result in
different outcomes of a subsequent write depending on the values of offset
and len.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@parisplace.org>
Cc: John McCutchan <john@johnmccutchan.com>
Cc: Robert Love <rlove@rlove.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:53 -08:00
Thierry Reding
620951e274 mm/cma: make kmemleak ignore CMA regions
kmemleak will add allocations as objects to a pool.  The memory allocated
for each object in this pool is periodically searched for pointers to
other allocated objects.  This only works for memory that is mapped into
the kernel's virtual address space, which happens not to be the case for
most CMA regions.

Furthermore, CMA regions are typically used to store data transferred to
or from a device and therefore don't contain pointers to other objects.

Without this, the kernel crashes on the first execution of the
scan_gray_list() because it tries to access highmem.  Perhaps a more
appropriate fix would be to reject any object that can't map to a kernel
virtual address?

[akpm@linux-foundation.org: add comment]
[akpm@linux-foundation.org: fix comment, per Catalin]
[sfr@canb.auug.org.au: include linux/io.h for phys_to_virt()]
Signed-off-by: Thierry Reding <treding@nvidia.com>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:53 -08:00
Vladimir Davydov
dee2f8aaab slub: fix cpuset check in get_any_partial
If we fail to allocate from the current node's stock, we look for free
objects on other nodes before calling the page allocator (see
get_any_partial).  While checking other nodes we respect cpuset
constraints by calling cpuset_zone_allowed.  We enforce hardwall check.
As a result, we will fallback to the page allocator even if there are some
pages cached on other nodes, but the current cpuset doesn't have them set.
 However, the page allocator uses softwall check for kernel allocations,
so it may allocate from one of the other nodes in this case.

Therefore we should use softwall cpuset check in get_any_partial to
conform with the cpuset check in the page allocator.

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Acked-by: Zefan Li <lizefan@huawei.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:53 -08:00
Vladimir Davydov
061d7074e1 slab: fix cpuset check in fallback_alloc
fallback_alloc is called on kmalloc if the preferred node doesn't have
free or partial slabs and there's no pages on the node's free list
(GFP_THISNODE allocations fail).  Before invoking the reclaimer it tries
to locate a free or partial slab on other allowed nodes' lists.  While
iterating over the preferred node's zonelist it skips those zones which
hardwall cpuset check returns false for.  That means that for a task bound
to a specific node using cpusets fallback_alloc will always ignore free
slabs on other nodes and go directly to the reclaimer, which, however, may
allocate from other nodes if cpuset.mem_hardwall is unset (default).  As a
result, we may get lists of free slabs grow without bounds on other nodes,
which is bad, because inactive slabs are only evicted by cache_reap at a
very slow rate and cannot be dropped forcefully.

To reproduce the issue, run a process that will walk over a directory tree
with lots of files inside a cpuset bound to a node that constantly
experiences memory pressure.  Look at num_slabs vs active_slabs growth as
reported by /proc/slabinfo.

To avoid this we should use softwall cpuset check in fallback_alloc.

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Acked-by: Zefan Li <lizefan@huawei.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:53 -08:00
Dave Hansen
07a46ed27d shmdt: use i_size_read() instead of ->i_size
Andrew Morton noted

	http://lkml.kernel.org/r/20141104142027.a7a0d010772d84560b445f59@linux-foundation.org

that the shmdt uses inode->i_size outside of i_mutex being held.
There is one more case in shm.c in shm_destroy().  This converts
both users over to use i_size_read().

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:52 -08:00
Dave Hansen
d3c97900b4 ipc/shm.c: fix overly aggressive shmdt() when calls span multiple segments
This is a highly-contrived scenario.  But, a single shmdt() call can be
induced in to unmapping memory from mulitple shm segments.  Example code
is here:

	http://www.sr71.net/~dave/intel/shmfun.c

The fix is pretty simple: Record the 'struct file' for the first VMA we
encounter and then stick to it.  Decline to unmap anything not from the
same file and thus the same segment.

I found this by inspection and the odds of anyone hitting this in practice
are pretty darn small.

Lightly tested, but it's a pretty small patch.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:52 -08:00
Manfred Spraul
0050ee059f ipc/msg: increase MSGMNI, remove scaling
SysV can be abused to allocate locked kernel memory.  For most systems, a
small limit doesn't make sense, see the discussion with regards to SHMMAX.

Therefore: increase MSGMNI to the maximum supported.

And: If we ignore the risk of locking too much memory, then an automatic
scaling of MSGMNI doesn't make sense.  Therefore the logic can be removed.

The code preserves auto_msgmni to avoid breaking any user space applications
that expect that the value exists.

Notes:
1) If an administrator must limit the memory allocations, then he can set
MSGMNI as necessary.

Or he can disable sysv entirely (as e.g. done by Android).

2) MSGMAX and MSGMNB are intentionally not increased, as these values are used
to control latency vs. throughput:
If MSGMNB is large, then msgsnd() just returns and more messages can be queued
before a task switch to a task that calls msgrcv() is forced.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Rafael Aquini <aquini@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:52 -08:00
Manfred Spraul
e843e7d2c8 ipc/sem.c: increase SEMMSL, SEMMNI, SEMOPM
a)

SysV can be abused to allocate locked kernel memory.  For most systems, a
small limit doesn't make sense, see the discussion with regards to SHMMAX.

Therefore: Increase the sysv sem limits so that all known applications
will work with these defaults.

b)

With regards to the maximum supported:
Some of the specified hard limits are not correct anymore, therefore the
patch updates the documentation.

- SEMMNI must stay below IPCMNI, which is 32768.
  As for SHMMAX: Stay a bit below this limit.

- SEMMSL was limited to 8k, to ensure that the kmalloc for the kernel array
  was limited to 16 kB (order=2)

  This doesn't apply anymore:
   - the allocation size isn't sizeof(short)*nsems anymore.
   - ipc_alloc falls back to vmalloc

- SEMOPM should stay below 1000, to limit the kmalloc in semtimedop() to an
  order=1 allocation.
  Therefore: Leave it at 500 (order=0 allocation).

Note:
If an administrator must limit the memory allocations, then he can set the
values as necessary.

Or he can disable sysv entirely (as e.g. done by Android).

Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Acked-by: Rafael Aquini <aquini@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:52 -08:00
Manfred Spraul
2e094abfd1 ipc/sem.c: change memory barrier in sem_lock() to smp_rmb()
When I fixed bugs in the sem_lock() logic, I was more conservative than
necessary.  Therefore it is safe to replace the smp_mb() with smp_rmb().
And: With smp_rmb(), semop() syscalls are up to 10% faster.

The race we must protect against is:

	sem->lock is free
	sma->complex_count = 0
	sma->sem_perm.lock held by thread B

thread A:

A: spin_lock(&sem->lock)

			B: sma->complex_count++; (now 1)
			B: spin_unlock(&sma->sem_perm.lock);

A: spin_is_locked(&sma->sem_perm.lock);
A: XXXXX memory barrier
A: if (sma->complex_count == 0)

Thread A must read the increased complex_count value, i.e. the read must
not be reordered with the read of sem_perm.lock done by spin_is_locked().

Since it's about ordering of reads, smp_rmb() is sufficient.

[akpm@linux-foundation.org: update sem_lock() comment, from Davidlohr]
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Acked-by: Rafael Aquini <aquini@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:52 -08:00
Haesung Kim
a060bfe032 lib/decompress.c: consistency of compress formats for kernel image
Magic number of compress formats for kernel image is defined by two bytes.
 These numbers are written in hexadecimal number, nevertheless magic
number for only gunzip is written in octal number.  The formats should be
consistent for readability.  Therefore, magic numbers for gunzip are also
defined by hexadecimal number.

Signed-off-by: Haesung Kim <matia.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:52 -08:00
Dan Carpenter
b5c8afe5be decompress_bunzip2: off by one in get_next_block()
"origPtr" is used as an offset into the bd->dbuf[] array.  That array is
allocated in start_bunzip() and has "bd->dbufSize" number of elements so
the test here should be >= instead of >.

Later we check "origPtr" again before using it as an offset so I don't
know if this bug can be triggered in real life.

Fixes: bc22c17e12 ('bzip2/lzma: library support for gzip, bzip2 and lzma decompression')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Alain Knaff <alain@knaff.lu>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:52 -08:00
Andi Kleen
ec72c666fb usr/Kconfig: make initrd compression algorithm selection not expert
The kernel has support for (nearly) every compression algorithm known to
man, each to handle some particular microscopic niche.

Unfortunately all of these always get compiled in if you want to support
INITRDs, and can be only disabled when CONFIG_EXPERT is set.

I don't see why I need to set EXPERT just to properly configure the initrd
compression algorithms, and not always include every possible algorithm

Usually the initrd is just compressed with gzip anyways, at least that's
true on all distributions I use.

Remove the dependencies for initrd compression on CONFIG_EXPERT.

Make the various options just default y, which should be good enough to
not break any previous configuration.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:52 -08:00
Dmitry Monakhov
6adc4a22f2 fault-inject: add ratelimit option
Current debug levels are not optimal.  Especially if one want to provoke
big numbers of faults(broken device simulator) then any verbose level will
produce giant numbers of identical logging messages.  Let's add ratelimit
parameter for that purpose.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Acked-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:52 -08:00
Dmitry Monakhov
89e3f90995 ratelimit: add initialization macro
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:52 -08:00
Fabian Frederick
92cab82b2c fs/affs/file.c: remove obsolete pagesize check
linux kernel doesn't manage page sizes below 4kb.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:52 -08:00
Fabian Frederick
9abb408307 fs/affs/file.c: add support to O_DIRECT
Based on ext2_direct_IO

Tested with O_DIRECT file open and sysbench/mariadb with 1% written
queries improvement (update_non_index test) on a volume created with
mkaffs.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:51 -08:00
Fabian Frederick
1ee54b099a fs/affs/amigaffs.c: use va_format instead of buffer/vnsprintf
-Remove ErrorBuffer and use %pV

-Add __printf to enable argument mistmatch warnings

Original patch by Joe Perches.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:51 -08:00
Fabian Frederick
7633978b43 fs/affs/file.c: forward declaration clean-up
-Move file_operations to avoid forward declarations.

-Remove unused declarations.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:51 -08:00
Riku Voipio
957e3facd1 gcov: enable GCOV_PROFILE_ALL from ARCH Kconfigs
Following the suggestions from Andrew Morton and Stephen Rothwell,
Dont expand the ARCH list in kernel/gcov/Kconfig. Instead,
define a ARCH_HAS_GCOV_PROFILE_ALL bool which architectures
can enable.

set ARCH_HAS_GCOV_PROFILE_ALL on Architectures where it was
previously allowed + ARM64 which I tested.

Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Cc: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:51 -08:00
Masanari Iida
d5393955c3 kexec: remove unnecessary KERN_ERR from kexec.c
Remove unnecessary KERN_ERR from pr_err() within kexec.c.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:51 -08:00
David Drysdale
38351a329d sparc: hook up execveat system call
Signed-off-by: David Drysdale <drysdale@google.com>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:51 -08:00
David Drysdale
c9b26b81af syscalls: add selftest for execveat(2)
Signed-off-by: David Drysdale <drysdale@google.com>
Cc: Meredydd Luff <meredydd@senatehouse.org>
Cc: Shuah Khan <shuah.kh@samsung.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rich Felker <dalias@aerifal.cx>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:51 -08:00
David Drysdale
27d6ec7ad6 x86: hook up execveat system call
Hook up x86-64, i386 and x32 ABIs.

Signed-off-by: David Drysdale <drysdale@google.com>
Cc: Meredydd Luff <meredydd@senatehouse.org>
Cc: Shuah Khan <shuah.kh@samsung.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rich Felker <dalias@aerifal.cx>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:51 -08:00
David Drysdale
51f39a1f0c syscalls: implement execveat() system call
This patchset adds execveat(2) for x86, and is derived from Meredydd
Luff's patch from Sept 2012 (https://lkml.org/lkml/2012/9/11/528).

The primary aim of adding an execveat syscall is to allow an
implementation of fexecve(3) that does not rely on the /proc filesystem,
at least for executables (rather than scripts).  The current glibc version
of fexecve(3) is implemented via /proc, which causes problems in sandboxed
or otherwise restricted environments.

Given the desire for a /proc-free fexecve() implementation, HPA suggested
(https://lkml.org/lkml/2006/7/11/556) that an execveat(2) syscall would be
an appropriate generalization.

Also, having a new syscall means that it can take a flags argument without
back-compatibility concerns.  The current implementation just defines the
AT_EMPTY_PATH and AT_SYMLINK_NOFOLLOW flags, but other flags could be
added in future -- for example, flags for new namespaces (as suggested at
https://lkml.org/lkml/2006/7/11/474).

Related history:
 - https://lkml.org/lkml/2006/12/27/123 is an example of someone
   realizing that fexecve() is likely to fail in a chroot environment.
 - http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=514043 covered
   documenting the /proc requirement of fexecve(3) in its manpage, to
   "prevent other people from wasting their time".
 - https://bugzilla.redhat.com/show_bug.cgi?id=241609 described a
   problem where a process that did setuid() could not fexecve()
   because it no longer had access to /proc/self/fd; this has since
   been fixed.

This patch (of 4):

Add a new execveat(2) system call.  execveat() is to execve() as openat()
is to open(): it takes a file descriptor that refers to a directory, and
resolves the filename relative to that.

In addition, if the filename is empty and AT_EMPTY_PATH is specified,
execveat() executes the file to which the file descriptor refers.  This
replicates the functionality of fexecve(), which is a system call in other
UNIXen, but in Linux glibc it depends on opening "/proc/self/fd/<fd>" (and
so relies on /proc being mounted).

The filename fed to the executed program as argv[0] (or the name of the
script fed to a script interpreter) will be of the form "/dev/fd/<fd>"
(for an empty filename) or "/dev/fd/<fd>/<filename>", effectively
reflecting how the executable was found.  This does however mean that
execution of a script in a /proc-less environment won't work; also, script
execution via an O_CLOEXEC file descriptor fails (as the file will not be
accessible after exec).

Based on patches by Meredydd Luff.

Signed-off-by: David Drysdale <drysdale@google.com>
Cc: Meredydd Luff <meredydd@senatehouse.org>
Cc: Shuah Khan <shuah.kh@samsung.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rich Felker <dalias@aerifal.cx>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:51 -08:00
Namjae Jeon
c0ef0cc9d2 fat: fix data past EOF resulting from fsx testsuite
When running FSX with direct I/O mode, fsx resulted in DATA past EOF issues.

  fsx ./file2 -Z -r 4096 -w 4096
  ...
  ..
  truncating to largest ever: 0x907c
  fallocating to largest ever: 0x11137
  truncating to largest ever: 0x2c6fe
  truncating to largest ever: 0x2cfdf
  fallocating to largest ever: 0x40000
  Mapped Read: non-zero data past EOF (0x18628) page offset 0x629 is 0x2a4e
  ...
  ..

The reason being, it is doing a truncate down, but the zeroing does not
happen on the last block boundary when offset is not aligned.  Even though
it calls truncate_setsize()->truncate_inode_pages()->
truncate_inode_pages_range() and considers the partial zeroout but it
retrieves the page using find_lock_page() - which only looks the page in
the cache.  So, zeroing out does not happen in case of direct IO.

Make a truncate page based around block_truncate_page for FAT filesystem
and invoke that helper to zerout in case the offset is not aligned with
the blocksize.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:51 -08:00
Jan Kara
f441ada004 befs: remove dead code
Coverity id: 1042674

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:51 -08:00
Heesub Shin
1dd61aa31c mm/zbud: init user ops only when it is needed
When zbud is initialized through the zpool wrapper, pool->ops which
points to user-defined operations is always set regardless of whether it
is specified from the upper layer. This causes zbud_reclaim_page() to
iterate its loop for evicting pool pages out without any gain.

This patch sets the user-defined ops only when it is needed, so that
zbud_reclaim_page() can bail out the reclamation loop earlier if there
is no user-defined operations specified.

Signed-off-by: Heesub Shin <heesub.shin@samsung.com>
Acked-by: Dan Streetman <ddstreet@ieee.org>
Cc: Seth Jennings <sjennings@variantweb.net>
Cc: Sunae Seo <sunae.seo@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:51 -08:00
Markus Elfring
442cc432e6 mm/zswap: delete unnecessary check before calling free_percpu()
free_percpu() tests whether its argument is NULL and then returns
immediately.  Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Cc: Seth Jennings <sjennings@variantweb.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:50 -08:00
Mahendran Ganesh
dd01d7d89a mm/zswap: add __init to some functions in zswap
zswap_cpu_init/zswap_comp_exit/zswap_entry_cache_create is only called by
__init init_zswap()

Signed-off-by: Mahendran Ganesh <opensource.ganesh@gmail.com>
Cc: Seth Jennings <sjennings@variantweb.net>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:50 -08:00
Ganesh Mahendran
083914eab9 zram: use DEVICE_ATTR_[RW|RO|WO] to define zram sys device attribute
In current zram, we use DEVICE_ATTR() to define sys device attributes.
SO, we need to set (S_IRUGO | S_IWUSR) permission and other arguments
manually.  Linux already provids the macro DEVICE_ATTR_[RW|RO|WO] to
define sys device attribute.  It is simple and readable.

This patch uses kernel defined macro DEVICE_ATTR_[RW|RO|WO] to define
zram device attribute.

Signed-off-by: Ganesh Mahendran <opensource.ganesh@gmail.com>
Acked-by: Jerome Marchand <jmarchan@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:50 -08:00
Ganesh Mahendran
181366561a mm/zsmalloc: allocate exactly size of struct zs_pool
In zs_create_pool(), we allocate memory more then sizeof(struct zs_pool)
  ovhd_size = roundup(sizeof(*pool), PAGE_SIZE);

This patch allocate memory of exactly needed size.

Signed-off-by: Ganesh Mahendran <opensource.ganesh@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:50 -08:00
Ganesh Mahendran
df8b5bb998 mm/zsmalloc: avoid duplicate assignment of prev_class
In zs_create_pool(), prev_class is assigned (ZS_SIZE_CLASSES - 1) times.
And the prev_class only references to the previous size_class.  So we do
not need unnecessary assignement.

This patch assigns *prev_class* when a new size_class structure is
allocated and uses prev_class to check whether the first class has been
allocated.

[akpm@linux-foundation.org: remove now-unused ZS_SIZE_CLASSES]
Signed-off-by: Ganesh Mahendran <opensource.ganesh@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Reviewed-by: Dan Streetman <ddstreet@ieee.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:50 -08:00
Mahendran Ganesh
d49b1c254c mm/zram: correct ZRAM_ZERO flag bit position
In struct zram_table_entry, the element *value* contains obj size and obj
zram flags.  Bit 0 to bit (ZRAM_FLAG_SHIFT - 1) represent obj size, and
bit ZRAM_FLAG_SHIFT to the highest bit of unsigned long represent obj
zram_flags.  So the first zram flag(ZRAM_ZERO) should be from
ZRAM_FLAG_SHIFT instead of (ZRAM_FLAG_SHIFT + 1).

This patch fixes this cosmetic issue.

Also fix a typo, "page in now accessed" -> "page is now accessed"

Signed-off-by: Mahendran Ganesh <opensource.ganesh@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: Weijie Yang <weijie.yang@samsung.com>
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:50 -08:00
Mahendran Ganesh
40f9fb8cff mm/zsmalloc: support allocating obj with size of ZS_MAX_ALLOC_SIZE
I sent a patch [1] for unnecessary check in zsmalloc.  And Minchan Kim
found zsmalloc even does not support allocating an obj with the size of
ZS_MAX_ALLOC_SIZE in some situations.

For example:
   In system with 64KB PAGE_SIZE and 32 bit of physical addr. Then:
   ZS_MIN_ALLOC_SIZE is 32 bytes which is calculated by:
      MAX(32, (ZS_MAX_PAGES_PER_ZSPAGE << PAGE_SHIFT >> OBJ_INDEX_BITS))
   ZS_MAX_ALLOC_SIZE is 64KB(in current code, is PAGE_SIZE)
   ZS_SIZE_CLASS_DELTA is 256 bytes
   So, ZS_SIZE_CLASSES = (ZS_MAX_ALLOC_SIZE - ZS_MIN_ALLOC_SIZE) /
                          ZS_SIZE_CLASS_DELTA + 1
                       = 256

   In zs_create_pool(), the max size obj which can be allocated will be:
      ZS_MIN_ALLOC_SIZE + i * ZS_SIZE_CLASS_DELTA = 32 + 255*256 = 65312

   We can see that 65312 < 65536 (ZS_MAX_ALLOC_SIZE). So we can NOT
   allocate objs with size ZS_MAX_ALLOC_SIZE(65536) which we promise upper
   users we can do.

 [1]  http://lkml.iu.edu/hypermail/linux/kernel/1411.2/03835.html
 [2]  http://lkml.iu.edu/hypermail/linux/kernel/1411.2/04534.html

This patch fixes this issue by dynamiclly calculating zs_size_classes when
module is loaded, allocates buffer with size ZS_MAX_ALLOC_SIZE.  Then the
max obj(size is ZS_MAX_ALLOC_SIZE) can be stored in it.

[akpm@linux-foundation.org: restore ZS_SIZE_CLASSES to fix bisectability]
Signed-off-by: Mahendran Ganesh <opensource.ganesh@gmail.com>
Suggested-by: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:50 -08:00
Minchan Kim
af4ee5e977 zsmalloc: correct fragile [kmap|kunmap]_atomic use
The kunmap_atomic should use virtual address getting by kmap_atomic.
However, some pieces of code in zsmalloc uses modified address, not the
one got by kmap_atomic for kunmap_atomic.

It's okay for working because zsmalloc modifies the address inner
PAGE_SIZE bounday so it works with current kmap_atomic's implementation.
But it's still fragile with potential changing of kmap_atomic so let's
correct it.

I got a subtle bug when I implemented a new feature of zsmalloc
(compaction) due to a link's mishandling (the link was over page
boundary).  Although it was totally my mistake, it took a while to find
the cause because an unpredictable kmapped address was unmapped causing an
almost random crash.

Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Seth Jennings <sjennings@variantweb.net>
Cc: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:50 -08:00
Sergey Senozhatsky
b1b00a5b8a zsmalloc: fix zs_init cpu notifier error handling
Mahendran Ganesh reported that zpool-enabled zsmalloc should not call
zpool_unregister_driver() from zs_init() if cpu notifier registration has
failed, because error handling is performed before we register the driver
via zpool_register_driver() call.

Factor out cpu notifier registration and unregistration code and fix
zs_init() error handling.

link: http://lkml.iu.edu//hypermail/linux/kernel/1411.1/04156.html
[akpm@linux-foundation.org: squash bogus gcc warning]
[akpm@linux-foundation.org: use __init and __exit]
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reported-by: Mahendran Ganesh <opensource.ganesh@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-12-13 12:42:50 -08:00