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7 years agoMerge branch 'jani-rest' into docs-next
Jonathan Corbet [Sat, 14 May 2016 16:21:57 +0000 (10:21 -0600)]
Merge branch 'jani-rest' into docs-next

Patch series from Jani Nikula:

> Jon, I was hoping we could consider nudging things forward a bit in the
> kernel-doc and docproc reStructuredText front already in 4.7. I know
> it's a bit close to the merge window, but this should not interfere with
> anything else, and some of it are just trivial cleanups that I've been
> carrying around locally.
>
> Obviously this doesn't actually add anything that uses them yet, but I
> think it would be helpful to have some common base in to ease
> collaboration.

7 years agoserial: doc: Use port->state instead of info
Geert Uytterhoeven [Wed, 11 May 2016 11:56:05 +0000 (13:56 +0200)]
serial: doc: Use port->state instead of info

As of commit ebd2c8f6d2ec4012 ("serial: kill off uart_info"), the
circular transmission buffer is part of struct uart_state instead of
struct uart_info. Make it clear this structure is pointed to from struct
uart_port.

Change 'circ' to 'circ_buf' to match the structure name while we're at
it.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
7 years agoserial: doc: Always refer to tty_port->mutex
Geert Uytterhoeven [Wed, 11 May 2016 11:56:04 +0000 (13:56 +0200)]
serial: doc: Always refer to tty_port->mutex

Stop referring to the mutex member of the tty_port struct as
'port->mutex', as 'port' is ambiguous, and usually refers to the
uart_port struct in this document.  Use 'tty_port->mutex' instead,
following the single existing use.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
7 years agoDocumentation: vm: Spelling s/paltform/platform/g
Geert Uytterhoeven [Tue, 10 May 2016 18:59:56 +0000 (20:59 +0200)]
Documentation: vm: Spelling s/paltform/platform/g

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
7 years agoDocumentation/memcg: update kmem limit doc as codes behavior
Qiang Huang [Wed, 11 May 2016 06:07:31 +0000 (14:07 +0800)]
Documentation/memcg: update kmem limit doc as codes behavior

The restriction of kmem setting is not there anymore because the
accounting is enabled by default even in the cgroup v1 - see
b313aeee2509 ("mm: memcontrol: enable kmem accounting for all
cgroups in the legacy hierarchy").

Update docs accordingly.

Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
7 years agodocproc: print a comment about autogeneration for rst output
Jani Nikula [Thu, 12 May 2016 13:15:44 +0000 (16:15 +0300)]
docproc: print a comment about autogeneration for rst output

Leave a hint to folks which file to edit instead.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
7 years agodocproc: add support for reStructuredText format via --rst option
Jani Nikula [Thu, 12 May 2016 13:15:43 +0000 (16:15 +0300)]
docproc: add support for reStructuredText format via --rst option

Expect reStructuredText input and have kernel-doc produce
reStructuredText output with the new --rst option. Also add --docbook
option for completeness. If no option is given, default to
reStructuredText if the input file has ".rst" extension, DocBook
otherwise.

Directives for reStructuredText use .. ! instead of just !, to make them
reStructuredText comments.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
7 years agodocproc: abstract terminating lines at first space
Jani Nikula [Thu, 12 May 2016 13:15:42 +0000 (16:15 +0300)]
docproc: abstract terminating lines at first space

Cleaner code. Also fixes a bug when F or P directives didn't in fact
have space.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
7 years agodocproc: abstract docproc directive detection
Jani Nikula [Thu, 12 May 2016 13:15:41 +0000 (16:15 +0300)]
docproc: abstract docproc directive detection

Helps follow-up work. No functional changes.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
7 years agodocproc: reduce unnecessary indentation
Jani Nikula [Thu, 12 May 2016 13:15:40 +0000 (16:15 +0300)]
docproc: reduce unnecessary indentation

Improves clarity. No functional changes.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
7 years agodocproc: add variables for subcommand and filename
Jani Nikula [Thu, 12 May 2016 13:15:39 +0000 (16:15 +0300)]
docproc: add variables for subcommand and filename

Improves clarity. No functional changes.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
7 years agokernel-doc: use rst C domain directives and references for types
Jani Nikula [Thu, 12 May 2016 13:15:38 +0000 (16:15 +0300)]
kernel-doc: use rst C domain directives and references for types

First, the headings for structs, enums and typedefs will be similar to
functions. Second, this provides a kind of namespace for cross
references. Third, and most importantly, the return and parameter types
from .. c:function:: definitions will automagically become cross
references to the documented types.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
7 years agokernel-doc: produce RestructuredText output
Jonathan Corbet [Thu, 12 May 2016 13:15:37 +0000 (16:15 +0300)]
kernel-doc: produce RestructuredText output

If given the -rst flag, output will now be in RestructuredText.  Various
glitches to be worked out yet.

In the end I decided not to use RST section headings within the kerneldoc
comments.  gpu.tmpl already has headings five levels deep; adding more is
not going to bring clarity.

This is really just Jani Nikula's asciidoc change with the serial numbers
filed off.  It's a hack job that doubtless needs a lot of cleaning up.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
7 years agokernel-doc: rewrite usage description, remove duplicated comments
Jani Nikula [Thu, 12 May 2016 13:15:36 +0000 (16:15 +0300)]
kernel-doc: rewrite usage description, remove duplicated comments

Instead of having the kernel-doc usage in both comments and in output to
the user, merge them all to one here document. While at it, imrove the
text and make it pretty. Give shoemaker's children some shoes.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agoDoc: correct the location of sysrq.c
René Nyffenegger [Thu, 28 Apr 2016 08:15:24 +0000 (10:15 +0200)]
Doc: correct the location of sysrq.c

sysrq.c moved to drivers/tty in 2010; update the documentation to match.

Signed-off-by: René Nyffenegger <mail@renenyffenegger.ch>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agoDocumentation: fix common spelling mistakes
Kees Cook [Tue, 26 Apr 2016 23:41:21 +0000 (16:41 -0700)]
Documentation: fix common spelling mistakes

This fixes several spelling mistakes in the Documentation/ tree, which
are caught by checkpatch.pl's spell checking.

Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agosamples: v4l: from Documentation to samples directory
Arnd Bergmann [Mon, 25 Apr 2016 16:03:09 +0000 (18:03 +0200)]
samples: v4l: from Documentation to samples directory

A small bug with the new autoksyms support showed that there are
two kernel modules in the Documentation directory that qualify
as samples, while all other samples are in the samples/ directory.

This patch was originally meant as a workaround for that bug, but
it has now been solved in a different way. However, I still think
it makes sense as a cleanup to consolidate all sample code in
one place.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agosamples: connector: from Documentation to samples directory
Arnd Bergmann [Mon, 25 Apr 2016 16:03:08 +0000 (18:03 +0200)]
samples: connector: from Documentation to samples directory

A small bug with the new autoksyms support showed that there are
two kernel modules in the Documentation directory that qualify
as samples, while all other samples are in the samples/ directory.

This patch was originally meant as a workaround for that bug, but
it has now been solved in a different way. However, I still think
it makes sense as a cleanup to consolidate all sample code in
one place.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agoDocumentation: xillybus: fix spelling mistake
Eric Engestrom [Mon, 25 Apr 2016 06:37:07 +0000 (07:37 +0100)]
Documentation: xillybus: fix spelling mistake

Signed-off-by: Eric Engestrom <eric@engestrom.ch>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agoDocumentation: x86: fix spelling mistakes
Eric Engestrom [Mon, 25 Apr 2016 06:37:06 +0000 (07:37 +0100)]
Documentation: x86: fix spelling mistakes

Signed-off-by: Eric Engestrom <eric@engestrom.ch>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agoDocumentation: scsi: fix spelling mistakes
Eric Engestrom [Mon, 25 Apr 2016 06:37:01 +0000 (07:37 +0100)]
Documentation: scsi: fix spelling mistakes

Signed-off-by: Eric Engestrom <eric@engestrom.ch>
[jc: fixed trailing whitespace errors]
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agoDocumentation: robust-futexes: fix spelling mistakes
Eric Engestrom [Mon, 25 Apr 2016 06:37:00 +0000 (07:37 +0100)]
Documentation: robust-futexes: fix spelling mistakes

Signed-off-by: Eric Engestrom <eric@engestrom.ch>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agoDocumentation: pps: fix spelling mistake
Eric Engestrom [Mon, 25 Apr 2016 06:36:58 +0000 (07:36 +0100)]
Documentation: pps: fix spelling mistake

Signed-off-by: Eric Engestrom <eric@engestrom.ch>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agoDocumentation: lzo: fix spelling mistakes
Eric Engestrom [Mon, 25 Apr 2016 06:36:55 +0000 (07:36 +0100)]
Documentation: lzo: fix spelling mistakes

Signed-off-by: Eric Engestrom <eric@engestrom.ch>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agoDocumentation: laptops: fix spelling mistake
Eric Engestrom [Mon, 25 Apr 2016 06:36:53 +0000 (07:36 +0100)]
Documentation: laptops: fix spelling mistake

Signed-off-by: Eric Engestrom <eric@engestrom.ch>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agoDocumentation: devres: Add missing INPUT function
Alexander Kurz [Thu, 21 Apr 2016 17:02:04 +0000 (19:02 +0200)]
Documentation: devres: Add missing INPUT function

devm_input_allocate_device() got introduced with commit 2be975c6d920
("Input: introduce managed input devices (add devres support)").
Add this function to the list of managed interfaces within the
devres documentation.

Signed-off-by: Alexander Kurz <akurz@blala.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agoDocumentation:Update Documentation/zh_CN/arm64/booting.txt
Fu Wei [Thu, 21 Apr 2016 13:45:40 +0000 (21:45 +0800)]
Documentation:Update Documentation/zh_CN/arm64/booting.txt

This is a update of Chinese documentation: Documentation/zh_CN/arm64/booting.txt

It is based on the modifications of Documentation/arm64/booting.txt in submission:
"a7f8de16".

Signed-off-by: Fu Wei <wefu@redhat.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agohrtimers: doc cleanup
Cao jin [Thu, 21 Apr 2016 13:39:15 +0000 (21:39 +0800)]
hrtimers: doc cleanup

It has:
a tense correction(led->leads);
a typo(unevitably->inevitably);

Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agodocumentation: trivial typo: adding-syscalls.txt: s/statat/fstatat/
Askar Safin [Mon, 18 Apr 2016 17:30:56 +0000 (20:30 +0300)]
documentation: trivial typo: adding-syscalls.txt: s/statat/fstatat/

Signed-off-by: Askar Safin <safinaskar@mail.ru>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agoDocumentation: HOWTO: update git home URL in translations
SeongJae Park [Sat, 16 Apr 2016 00:32:30 +0000 (09:32 +0900)]
Documentation: HOWTO: update git home URL in translations

Homepage url of git in HOWTO document was updated by commit
e234ebf7881c013b654113f0a208977ac3ce1d01 ("Documentation/HOWTO: update
git home URL") but not applied to several translations.  This commit
updates them.

Signed-off-by: SeongJae Park <sj38.park@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agoDocumentatio: HOWTO: remove regression postings info from translations
SeongJae Park [Sat, 16 Apr 2016 00:18:46 +0000 (09:18 +0900)]
Documentatio: HOWTO: remove regression postings info from translations

Obsolete info about regression postings were removed by commit
5645a717c6ee61e67d38aa9f15cb9db074e1e99d ("Documentation: HOWTO: remove
obsolete info about regression postings") but not applied to
translations.  This commit applies the change to translations.

Signed-off-by: SeongJae Park <sj38.park@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agoserial: doc: .break_ctl() may sleep
Geert Uytterhoeven [Thu, 14 Apr 2016 09:08:11 +0000 (11:08 +0200)]
serial: doc: .break_ctl() may sleep

break_ctl() is not called from any sort of atomic context, so there is no
problem with it sleeping.

Reported-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agoserial: doc: .(un)throttle() are serialized by the tty layer
Geert Uytterhoeven [Thu, 14 Apr 2016 09:08:10 +0000 (11:08 +0200)]
serial: doc: .(un)throttle() are serialized by the tty layer

Document that .(un)throttle() are serialized with each other, and with
termios modification by the tty layer.

Reported-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agoserial: doc: .(un)throttle() depends on hardware assisted flow control
Geert Uytterhoeven [Thu, 14 Apr 2016 09:08:09 +0000 (11:08 +0200)]
serial: doc: .(un)throttle() depends on hardware assisted flow control

Document that .throttle() and .unthrottle() are relevant only if
hardware assisted flow control is enabled.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agoserial: doc: Re-add paragraph documenting uart_console_write()
Geert Uytterhoeven [Thu, 14 Apr 2016 09:08:08 +0000 (11:08 +0200)]
serial: doc: Re-add paragraph documenting uart_console_write()

Commit 834392a7d92677ff ("serial: doc: Un-document non-existing
uart_write_console()") removed a paragraph about a helper function that
seemed to never exist.

Peter Hurley pointed out that the function does exist, but is called
differently. Re-add the paragraph, with the function name corrected.

Fixes: 834392a7d92677ff ("serial: doc: Un-document non-existing uart_write_console()")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agoDocumentation typo: wrong page flag bit for KPF_HUGE
Doug Hoyte [Wed, 13 Apr 2016 15:09:21 +0000 (11:09 -0400)]
Documentation typo: wrong page flag bit for KPF_HUGE

The correct value 17 can be found later in this document
and in the kernel-page-flags.h header (KPF_HUGE). I noticed
this while implementing vmprobe's kpageflags support.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agodoc: usb: Fix typo in gadget_multi documentation
Diego Herranz [Tue, 12 Apr 2016 17:13:27 +0000 (18:13 +0100)]
doc: usb: Fix typo in gadget_multi documentation

It tries to "match" drivers for each interface (not "much").

Signed-off-by: Diego Herranz <diegoherranz@diegoherranz.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agoREADME: remove trailing whitespace
Diego Viola [Sun, 3 Apr 2016 07:34:48 +0000 (04:34 -0300)]
README: remove trailing whitespace

Signed-off-by: Diego Viola <diego.viola@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agoDocumentation: update Michael K. Johnson's work
Luis de Bethencourt [Thu, 31 Mar 2016 11:10:30 +0000 (12:10 +0100)]
Documentation: update Michael K. Johnson's work

The URL for "Writing Linux Device Drivers" hasn't been available in some
time. Updating the entry to Michael K. Johnson's "Linux Kernel Hackers'
Guide"

Signed-off-by: Luis de Bethencourt <luisbg@osg.samsung.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agoserial: doc: Correct return type of mctrl_gpio_to_gpiod()
Geert Uytterhoeven [Mon, 14 Mar 2016 15:16:17 +0000 (16:16 +0100)]
serial: doc: Correct return type of mctrl_gpio_to_gpiod()

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agoserial: doc: Grammar s/function are/functions are/
Geert Uytterhoeven [Mon, 14 Mar 2016 15:16:16 +0000 (16:16 +0100)]
serial: doc: Grammar s/function are/functions are/

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agoserial: doc: Spelling s/divsor/divisor/
Geert Uytterhoeven [Mon, 14 Mar 2016 15:16:15 +0000 (16:16 +0100)]
serial: doc: Spelling s/divsor/divisor/

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agoserial: doc: .break_ctl() is called with port->mutex() held
Geert Uytterhoeven [Mon, 14 Mar 2016 15:16:14 +0000 (16:16 +0100)]
serial: doc: .break_ctl() is called with port->mutex() held

Note that mutex_lock() should not be called with interrupts disabled.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agoserial: doc: Document .set_ldisc()
Geert Uytterhoeven [Mon, 14 Mar 2016 15:16:13 +0000 (16:16 +0100)]
serial: doc: Document .set_ldisc()

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agoserial: doc: Document .unthrottle()
Geert Uytterhoeven [Mon, 14 Mar 2016 15:16:12 +0000 (16:16 +0100)]
serial: doc: Document .unthrottle()

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agoserial: doc: Document .throttle()
Geert Uytterhoeven [Mon, 14 Mar 2016 15:16:11 +0000 (16:16 +0100)]
serial: doc: Document .throttle()

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agoserial: doc: Un-document obsolete tmpbuf_sem
Geert Uytterhoeven [Mon, 14 Mar 2016 15:16:10 +0000 (16:16 +0100)]
serial: doc: Un-document obsolete tmpbuf_sem

uart_info.tmpbuf and uart_info.tmpbuf_sem were removed in v2.6.10, in
full-history-linux commit a797ad7e3ae9cad4 ("[SERIAL] Clean up
serial_core.c write functions.").

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agoserial: doc: Un-document non-existing uart_write_console()
Geert Uytterhoeven [Mon, 14 Mar 2016 15:16:09 +0000 (16:16 +0100)]
serial: doc: Un-document non-existing uart_write_console()

uart_write_console() never existed, not even when the "new
uart_write_console function" was documented.

Fixes: 67ab7f596b6adbae ("[SERIAL] Update serial driver documentation")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agoDocumentation: mmc: Add the introduction for mmc-utils
Baolin Wang [Wed, 16 Mar 2016 12:02:49 +0000 (20:02 +0800)]
Documentation: mmc: Add the introduction for mmc-utils

This patch introduces one mmc test tools called mmc-utils, which is convenient
if someone wants to exercise and test MMC/SD devices from userspace.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agoDocumentation: update URLs for Richard Gooch's articles
Luis de Bethencourt [Sat, 19 Mar 2016 12:51:23 +0000 (12:51 +0000)]
Documentation: update URLs for Richard Gooch's articles

Current URL for "Kernel API changes from 2.0 to 2.2" hasn't been available
for some time, updating. The second article about changes from 2.2 to 2.4
is missing a URL, adding it.

Signed-off-by: Luis de Bethencourt <luisbg@osg.samsung.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agoDocumentation: update URL of Analysis of the Ext2fs structure
Luis de Bethencourt [Sat, 19 Mar 2016 12:51:22 +0000 (12:51 +0000)]
Documentation: update URL of Analysis of the Ext2fs structure

The current URL has been down for some time, updating it to a working one.

Signed-off-by: Luis de Bethencourt <luisbg@osg.samsung.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agoDocumentation: add Linux Kernel Development book
Luis de Bethencourt [Sat, 19 Mar 2016 12:51:20 +0000 (12:51 +0000)]
Documentation: add Linux Kernel Development book

The Linux Kernel Development book by Robert Love has been recommended to me
by multiple kernel hackers. Worth having in the list of books in
kernel-docs.txt for newbies looking for good learning resources.

Signed-off-by: Luis de Bethencourt <luisbg@osg.samsung.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agoDocumentation: update missing index files in block/00-INDEX
Wei Fang [Mon, 21 Mar 2016 11:42:19 +0000 (19:42 +0800)]
Documentation: update missing index files in block/00-INDEX

Update missing index files in block/00-INDEX.

Signed-off-by: Wei Fang <fangwei1@huawei.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agoDocumentation/IRQ-domain.txt: Document irq_domain_create_{linear, tree}
Jianyu Zhan [Sun, 27 Mar 2016 03:51:20 +0000 (11:51 +0800)]
Documentation/IRQ-domain.txt: Document irq_domain_create_{linear, tree}

They have the same functionalities as irq_domain_add_{linear, tree},
except fro accepting different first argument.

Signed-off-by: Jianyu Zhan <nasa4836@gmail.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agobpf: doc: "neg" opcode has no operands
Dave Anderson [Mon, 28 Mar 2016 21:56:47 +0000 (14:56 -0700)]
bpf: doc: "neg" opcode has no operands

Fixes a copy-paste-o in the BPF opcode table: "neg" takes no arguments
and thus has no addressing modes.

Signed-off-by: Dave Anderson <danderson@google.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
8 years agoLinux 4.6-rc1 v4.6-rc1
Linus Torvalds [Sat, 26 Mar 2016 23:03:24 +0000 (16:03 -0700)]
Linux 4.6-rc1

8 years agoMerge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph...
Linus Torvalds [Sat, 26 Mar 2016 22:53:16 +0000 (15:53 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client

Pull Ceph updates from Sage Weil:
 "There is quite a bit here, including some overdue refactoring and
  cleanup on the mon_client and osd_client code from Ilya, scattered
  writeback support for CephFS and a pile of bug fixes from Zheng, and a
  few random cleanups and fixes from others"

[ I already decided not to pull this because of it having been rebased
  recently, but ended up changing my mind after all.  Next time I'll
  really hold people to it.  Oh well.   - Linus ]

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (34 commits)
  libceph: use KMEM_CACHE macro
  ceph: use kmem_cache_zalloc
  rbd: use KMEM_CACHE macro
  ceph: use lookup request to revalidate dentry
  ceph: kill ceph_get_dentry_parent_inode()
  ceph: fix security xattr deadlock
  ceph: don't request vxattrs from MDS
  ceph: fix mounting same fs multiple times
  ceph: remove unnecessary NULL check
  ceph: avoid updating directory inode's i_size accidentally
  ceph: fix race during filling readdir cache
  libceph: use sizeof_footer() more
  ceph: kill ceph_empty_snapc
  ceph: fix a wrong comparison
  ceph: replace CURRENT_TIME by current_fs_time()
  ceph: scattered page writeback
  libceph: add helper that duplicates last extent operation
  libceph: enable large, variable-sized OSD requests
  libceph: osdc->req_mempool should be backed by a slab pool
  libceph: make r_request msg_size calculation clearer
  ...

8 years agoMerge tag 'ofs-pull-tag-1' of git://git.kernel.org/pub/scm/linux/kernel/git/hubcap...
Linus Torvalds [Sat, 26 Mar 2016 19:59:04 +0000 (12:59 -0700)]
Merge tag 'ofs-pull-tag-1' of git://git.kernel.org/pub/scm/linux/kernel/git/hubcap/linux

Pull orangefs filesystem from Mike Marshall.

This finally merges the long-pending orangefs filesystem, which has been
much cleaned up with input from Al Viro over the last six months.  From
the documentation file:

 "OrangeFS is an LGPL userspace scale-out parallel storage system.  It
  is ideal for large storage problems faced by HPC, BigData, Streaming
  Video, Genomics, Bioinformatics.

  Orangefs, originally called PVFS, was first developed in 1993 by Walt
  Ligon and Eric Blumer as a parallel file system for Parallel Virtual
  Machine (PVM) as part of a NASA grant to study the I/O patterns of
  parallel programs.

  Orangefs features include:

    - Distributes file data among multiple file servers
    - Supports simultaneous access by multiple clients
    - Stores file data and metadata on servers using local file system
      and access methods
    - Userspace implementation is easy to install and maintain
    - Direct MPI support
    - Stateless"

see Documentation/filesystems/orangefs.txt for more in-depth details.

* tag 'ofs-pull-tag-1' of git://git.kernel.org/pub/scm/linux/kernel/git/hubcap/linux: (174 commits)
  orangefs: fix orangefs_superblock locking
  orangefs: fix do_readv_writev() handling of error halfway through
  orangefs: have ->kill_sb() evict the VFS side of things first
  orangefs: sanitize ->llseek()
  orangefs-bufmap.h: trim unused junk
  orangefs: saner calling conventions for getting a slot
  orangefs_copy_{to,from}_bufmap(): don't pass bufmap pointer
  orangefs: get rid of readdir_handle_s
  ornagefs: ensure that truncate has an up to date inode size
  orangefs: move code which sets i_link to orangefs_inode_getattr
  orangefs: remove needless wrapper around GFP_KERNEL
  orangefs: remove wrapper around mutex_lock(&inode->i_mutex)
  orangefs: refactor inode type or link_target change detection
  orangefs: use new getattr for revalidate and remove old getattr
  orangefs: use new getattr in inode getattr and permission
  orangefs: use new orangefs_inode_getattr to get size in write and llseek
  orangefs: use new orangefs_inode_getattr to create new inodes
  orangefs: rename orangefs_inode_getattr to orangefs_inode_old_getattr
  orangefs: remove inode->i_lock wrapper
  orangefs: put register_chrdev immediately before register_filesystem
  ...

8 years agoMerge tag 'ntb-4.6' of git://github.com/jonmason/ntb
Linus Torvalds [Sat, 26 Mar 2016 18:37:42 +0000 (11:37 -0700)]
Merge tag 'ntb-4.6' of git://github.com/jonmason/ntb

Pull NTB bug fixes from Jon Mason:
 "NTB bug fixes for tasklet from spinning forever, link errors,
  translation window setup, NULL ptr dereference, and ntb-perf errors.

  Also, a modification to the driver API that makes _addr functions
  optional"

* tag 'ntb-4.6' of git://github.com/jonmason/ntb:
  NTB: Remove _addr functions from ntb_hw_amd
  NTB: Make _addr functions optional in the API
  NTB: Fix incorrect clean up routine in ntb_perf
  NTB: Fix incorrect return check in ntb_perf
  ntb: fix possible NULL dereference
  ntb: add missing setup of translation window
  ntb: stop link work when we do not have memory
  ntb: stop tasklet from spinning forever during shutdown.
  ntb: perf test: fix address space confusion

8 years agoMerge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Linus Torvalds [Sat, 26 Mar 2016 18:31:01 +0000 (11:31 -0700)]
Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

Pull more SCSI updates from James Bottomley:
 "The only new stuff which missed the first pull request is an update to
  the UFS driver.

  The rest is an assortment of bug fixes and minor tweaks which appeared
  recently (some are fixes for recent code and some are stuff spotted
  recently by the checkers or the new gcc-6 compiler [most of Arnd's
  stuff])"

* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (32 commits)
  scsi_common: do not clobber fixed sense information
  scsi: ufs: select CONFIG_NLS
  scsi: fc: use get/put_unaligned64 for wwn access
  fnic: move printk()s outside of the critical code section.
  qla2xxx: avoid maybe_uninitialized warning
  megaraid_sas: add missing curly braces in ioctl handler
  lpfc: fix misleading indentation
  scsi_transport_sas: add 'scsi_target_id' sysfs attribute
  scsi_dh_alua: uninitialized variable in alua_check_vpd()
  scsi: ufs-qcom: add printouts of testbus debug registers
  scsi: ufs-qcom: enable/disable the device ref clock
  scsi: ufs-qcom: set PA_Local_TX_LCC_Enable before link startup
  scsi: ufs: add device quirk delay before putting UFS rails in LPM
  scsi: ufs: fix leakage during link off state
  scsi: ufs: tune UniPro parameters to optimize hibern8 exit time
  scsi: ufs: handle non spec compliant bkops behaviour by device
  scsi: ufs: add retry for query descriptors
  scsi: ufs: add error recovery after DL NAC error
  scsi: ufs: make error handling bit faster
  scsi: ufs: disable vccq if it's not needed by UFS device
  ...

8 years agof2fs/crypto: fix xts_tweak initialization
Linus Torvalds [Sat, 26 Mar 2016 17:13:05 +0000 (10:13 -0700)]
f2fs/crypto: fix xts_tweak initialization

Commit 0b81d07790726 ("fs crypto: move per-file encryption from f2fs
tree to fs/crypto") moved the f2fs crypto files to fs/crypto/ and
renamed the symbol prefixes from "f2fs_" to "fscrypt_" (and from "F2FS_"
to just "FS" for preprocessor symbols).

Because of the symbol renaming, it's a bit hard to see it as a file
move: use

    git show -M30 0b81d07790726

to lower the rename detection to just 30% similarity and make git show
the files as renamed (the header file won't be shown as a rename even
then - since all it contains is symbol definitions, it looks almost
completely different).

Even with the renames showing as renames, the diffs are not all that
easy to read, since so much is just the renames.  But Eric Biggers
noticed that it's not just all renames: the initialization of the
xts_tweak had been broken too, using the inode number rather than the
page offset.

That's not right - it makes the xfs_tweak the same for all pages of each
inode.  It _might_ make sense to make the xfs_tweak contain both the
offset _and_ the inode number, but not just the inode number.

Reported-by: Eric Biggers <ebiggers3@gmail.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoNTB: Remove _addr functions from ntb_hw_amd
Allen Hubbe [Mon, 21 Mar 2016 08:53:14 +0000 (04:53 -0400)]
NTB: Remove _addr functions from ntb_hw_amd

Kernel zero day testing warned about address space confusion.  A virtual
iomem address was used where a physical address is expected.  The
offending functions implement an optional part of the api, so they are
removed.  They can be added later, after testing.

Fixes: a1b3695820aa490e58915d720a1438069813008b
Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com>
Acked-by: Xiangliang Yu <Xiangliang.Yu@amd.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
8 years agoorangefs: fix orangefs_superblock locking
Al Viro [Fri, 25 Mar 2016 23:56:34 +0000 (19:56 -0400)]
orangefs: fix orangefs_superblock locking

* switch orangefs_remount() to taking ORANGEFS_SB(sb) instead of sb
* remove from the list _before_ orangefs_unmount() - request_mutex
in the latter will make sure that nothing observed in the loop in
ORANGEFS_DEV_REMOUNT_ALL handling will get freed until the end
of loop
* on removal, keep the forward pointer and zero the back one.  That
way we can drop and regain the spinlock in the loop body (again,
ORANGEFS_DEV_REMOUNT_ALL one) and still be able to get to the
rest of the list.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
8 years agoorangefs: fix do_readv_writev() handling of error halfway through
Al Viro [Wed, 17 Feb 2016 01:15:43 +0000 (20:15 -0500)]
orangefs: fix do_readv_writev() handling of error halfway through

Error should only be returned if nothing had been read/written.
Otherwise we need to report a short read/write instead.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
8 years agoorangefs: have ->kill_sb() evict the VFS side of things first
Al Viro [Wed, 17 Feb 2016 02:08:29 +0000 (21:08 -0500)]
orangefs: have ->kill_sb() evict the VFS side of things first

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
8 years agoorangefs: sanitize ->llseek()
Al Viro [Wed, 17 Feb 2016 01:25:19 +0000 (20:25 -0500)]
orangefs: sanitize ->llseek()

a) open files can't have NULL inodes
b) it's SEEK_END, not ORANGEFS_SEEK_END; no need to get cute.
c) make_bad_inode() on lseek()?

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
8 years agoorangefs-bufmap.h: trim unused junk
Al Viro [Wed, 17 Feb 2016 01:12:04 +0000 (20:12 -0500)]
orangefs-bufmap.h: trim unused junk

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
8 years agoorangefs: saner calling conventions for getting a slot
Al Viro [Wed, 17 Feb 2016 01:10:26 +0000 (20:10 -0500)]
orangefs: saner calling conventions for getting a slot

just have it return the slot number or -E... - the caller checks
the sign anyway

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
8 years agoorangefs_copy_{to,from}_bufmap(): don't pass bufmap pointer
Al Viro [Wed, 17 Feb 2016 01:06:19 +0000 (20:06 -0500)]
orangefs_copy_{to,from}_bufmap(): don't pass bufmap pointer

it's always __orangefs_bufmap

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
8 years agoorangefs: get rid of readdir_handle_s
Al Viro [Wed, 17 Feb 2016 00:54:13 +0000 (19:54 -0500)]
orangefs: get rid of readdir_handle_s

no point, really - we couldn't keep those across the calls of
getdents(); it would be too easy to DoS, having all slots exhausted.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
8 years agoMerge branch 'akpm' (patches from Andrew)
Linus Torvalds [Fri, 25 Mar 2016 23:59:11 +0000 (16:59 -0700)]
Merge branch 'akpm' (patches from Andrew)

Merge fourth patch-bomb from Andrew Morton:
 "A lot more stuff than expected, sorry.  A bunch of ocfs2 reviewing was
  finished off.

   - mhocko's oom-reaper out-of-memory-handler changes

   - ocfs2 fixes and features

   - KASAN feature work

   - various fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (42 commits)
  thp: fix typo in khugepaged_scan_pmd()
  MAINTAINERS: fill entries for KASAN
  mm/filemap: generic_file_read_iter(): check for zero reads unconditionally
  kasan: test fix: warn if the UAF could not be detected in kmalloc_uaf2
  mm, kasan: stackdepot implementation. Enable stackdepot for SLAB
  arch, ftrace: for KASAN put hard/soft IRQ entries into separate sections
  mm, kasan: add GFP flags to KASAN API
  mm, kasan: SLAB support
  kasan: modify kmalloc_large_oob_right(), add kmalloc_pagealloc_oob_right()
  include/linux/oom.h: remove undefined oom_kills_count()/note_oom_kill()
  mm/page_alloc: prevent merging between isolated and other pageblocks
  drivers/memstick/host/r592.c: avoid gcc-6 warning
  ocfs2: extend enough credits for freeing one truncate record while replaying truncate records
  ocfs2: extend transaction for ocfs2_remove_rightmost_path() and ocfs2_update_edge_lengths() before to avoid inconsistency between inode and et
  ocfs2/dlm: move lock to the tail of grant queue while doing in-place convert
  ocfs2: solve a problem of crossing the boundary in updating backups
  ocfs2: fix occurring deadlock by changing ocfs2_wq from global to local
  ocfs2/dlm: fix BUG in dlm_move_lockres_to_recovery_list
  ocfs2/dlm: fix race between convert and recovery
  ocfs2: fix a deadlock issue in ocfs2_dio_end_io_write()
  ...

8 years agoMerge tag 'pm+acpi-4.6-rc1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael...
Linus Torvalds [Fri, 25 Mar 2016 23:55:37 +0000 (16:55 -0700)]
Merge tag 'pm+acpi-4.6-rc1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fixlet from Rafael Wysocki:
 "One of commits in my previous pull request changed the permissions of
  drivers/power/avs/rockchip-io-domain.c to executable by mistake"

* tag 'pm+acpi-4.6-rc1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  Fix permissions of drivers/power/avs/rockchip-io-domain.c

8 years agoMerge tag 'please-pull-preadv2' of git://git.kernel.org/pub/scm/linux/kernel/git...
Linus Torvalds [Fri, 25 Mar 2016 23:48:45 +0000 (16:48 -0700)]
Merge tag 'please-pull-preadv2' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux

Pull ia64 update from Tony Luck:
 "Wire up new system calls p{read,write}v2 for ia64"

* tag 'please-pull-preadv2' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux:
  [IA64] Enable preadv2 and pwritev2 syscalls for ia64

8 years agoMerge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
Linus Torvalds [Fri, 25 Mar 2016 23:39:05 +0000 (16:39 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input

Pull more input updates from Dmitry Torokhov:
 "Second round of updates for the input subsystem.

  The BYD PS/2 protocol driver now uses absolute reporting mode and
  should behave more like other touchpads; Synaptics driver needed to
  extend one of its quirks to a newer firmware version, and a few USB
  drivers got tightened up checks for the contents of their descriptors"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: sur40 - fix DMA on stack
  Input: ati_remote2 - fix crashes on detecting device with invalid descriptor
  Input: synaptics - handle spurious release of trackstick buttons, again
  Input: synaptics-rmi4 - remove check of Non-NULL array
  Input: byd - enable absolute mode
  Input: ims-pcu - sanity check against missing interfaces
  Input: melfas_mip4 - add hw_version sysfs attribute

8 years agothp: fix typo in khugepaged_scan_pmd()
Kirill A. Shutemov [Fri, 25 Mar 2016 21:22:20 +0000 (14:22 -0700)]
thp: fix typo in khugepaged_scan_pmd()

!PageLRU should lead to SCAN_PAGE_LRU, not SCAN_SCAN_ABORT result.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Ebru Akagunduz <ebru.akagunduz@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoMAINTAINERS: fill entries for KASAN
Andrey Ryabinin [Fri, 25 Mar 2016 21:22:17 +0000 (14:22 -0700)]
MAINTAINERS: fill entries for KASAN

Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm/filemap: generic_file_read_iter(): check for zero reads unconditionally
Nicolai Stange [Fri, 25 Mar 2016 21:22:14 +0000 (14:22 -0700)]
mm/filemap: generic_file_read_iter(): check for zero reads unconditionally

If
 - generic_file_read_iter() gets called with a zero read length,
 - the read offset is at a page boundary,
 - IOCB_DIRECT is not set
-  and the page in question hasn't made it into the page cache yet,
then do_generic_file_read() will trigger a readahead with a req_size hint
of zero.

Since roundup_pow_of_two(0) is undefined, UBSAN reports

  UBSAN: Undefined behaviour in include/linux/log2.h:63:13
  shift exponent 64 is too large for 64-bit type 'long unsigned int'
  CPU: 3 PID: 1017 Comm: sa1 Tainted: G L 4.5.0-next-20160318+ #14
  [...]
  Call Trace:
   [...]
   [<ffffffff813ef61a>] ondemand_readahead+0x3aa/0x3d0
   [<ffffffff813ef61a>] ? ondemand_readahead+0x3aa/0x3d0
   [<ffffffff813c73bd>] ? find_get_entry+0x2d/0x210
   [<ffffffff813ef9c3>] page_cache_sync_readahead+0x63/0xa0
   [<ffffffff813cc04d>] do_generic_file_read+0x80d/0xf90
   [<ffffffff813cc955>] generic_file_read_iter+0x185/0x420
   [...]
   [<ffffffff81510b06>] __vfs_read+0x256/0x3d0
   [...]

when get_init_ra_size() gets called from ondemand_readahead().

The net effect is that the initial readahead size is arch dependent for
requested read lengths of zero: for example, since

  1UL << (sizeof(unsigned long) * 8)

evaluates to 1 on x86 while its result is 0 on ARMv7, the initial readahead
size becomes 4 on the former and 0 on the latter.

What's more, whether or not the file access timestamp is updated for zero
length reads is decided differently for the two cases of IOCB_DIRECT
being set or cleared: in the first case, generic_file_read_iter()
explicitly skips updating that timestamp while in the latter case, it is
always updated through the call to do_generic_file_read().

According to POSIX, zero length reads "do not modify the last data access
timestamp" and thus, the IOCB_DIRECT behaviour is POSIXly correct.

Let generic_file_read_iter() unconditionally check the requested read
length at its entry and return immediately with success if it is zero.

Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agokasan: test fix: warn if the UAF could not be detected in kmalloc_uaf2
Alexander Potapenko [Fri, 25 Mar 2016 21:22:11 +0000 (14:22 -0700)]
kasan: test fix: warn if the UAF could not be detected in kmalloc_uaf2

Signed-off-by: Alexander Potapenko <glider@google.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: 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: Andrey Konovalov <adech.fo@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm, kasan: stackdepot implementation. Enable stackdepot for SLAB
Alexander Potapenko [Fri, 25 Mar 2016 21:22:08 +0000 (14:22 -0700)]
mm, kasan: stackdepot implementation. Enable stackdepot for SLAB

Implement the stack depot and provide CONFIG_STACKDEPOT.  Stack depot
will allow KASAN store allocation/deallocation stack traces for memory
chunks.  The stack traces are stored in a hash table and referenced by
handles which reside in the kasan_alloc_meta and kasan_free_meta
structures in the allocated memory chunks.

IRQ stack traces are cut below the IRQ entry point to avoid unnecessary
duplication.

Right now stackdepot support is only enabled in SLAB allocator.  Once
KASAN features in SLAB are on par with those in SLUB we can switch SLUB
to stackdepot as well, thus removing the dependency on SLUB stack
bookkeeping, which wastes a lot of memory.

This patch is based on the "mm: kasan: stack depots" patch originally
prepared by Dmitry Chernenkov.

Joonsoo has said that he plans to reuse the stackdepot code for the
mm/page_owner.c debugging facility.

[akpm@linux-foundation.org: s/depot_stack_handle/depot_stack_handle_t]
[aryabinin@virtuozzo.com: comment style fixes]
Signed-off-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: 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: Andrey Konovalov <adech.fo@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoarch, ftrace: for KASAN put hard/soft IRQ entries into separate sections
Alexander Potapenko [Fri, 25 Mar 2016 21:22:05 +0000 (14:22 -0700)]
arch, ftrace: for KASAN put hard/soft IRQ entries into separate sections

KASAN needs to know whether the allocation happens in an IRQ handler.
This lets us strip everything below the IRQ entry point to reduce the
number of unique stack traces needed to be stored.

Move the definition of __irq_entry to <linux/interrupt.h> so that the
users don't need to pull in <linux/ftrace.h>.  Also introduce the
__softirq_entry macro which is similar to __irq_entry, but puts the
corresponding functions to the .softirqentry.text section.

Signed-off-by: Alexander Potapenko <glider@google.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: 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: Andrey Konovalov <adech.fo@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm, kasan: add GFP flags to KASAN API
Alexander Potapenko [Fri, 25 Mar 2016 21:22:02 +0000 (14:22 -0700)]
mm, kasan: add GFP flags to KASAN API

Add GFP flags to KASAN hooks for future patches to use.

This patch is based on the "mm: kasan: unified support for SLUB and SLAB
allocators" patch originally prepared by Dmitry Chernenkov.

Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: 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: Andrey Konovalov <adech.fo@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm, kasan: SLAB support
Alexander Potapenko [Fri, 25 Mar 2016 21:21:59 +0000 (14:21 -0700)]
mm, kasan: SLAB support

Add KASAN hooks to SLAB allocator.

This patch is based on the "mm: kasan: unified support for SLUB and SLAB
allocators" patch originally prepared by Dmitry Chernenkov.

Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: 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: Andrey Konovalov <adech.fo@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agokasan: modify kmalloc_large_oob_right(), add kmalloc_pagealloc_oob_right()
Alexander Potapenko [Fri, 25 Mar 2016 21:21:56 +0000 (14:21 -0700)]
kasan: modify kmalloc_large_oob_right(), add kmalloc_pagealloc_oob_right()

This patchset implements SLAB support for KASAN

Unlike SLUB, SLAB doesn't store allocation/deallocation stacks for heap
objects, therefore we reimplement this feature in mm/kasan/stackdepot.c.
The intention is to ultimately switch SLUB to use this implementation as
well, which will save a lot of memory (right now SLUB bloats each object
by 256 bytes to store the allocation/deallocation stacks).

Also neither SLUB nor SLAB delay the reuse of freed memory chunks, which
is necessary for better detection of use-after-free errors.  We
introduce memory quarantine (mm/kasan/quarantine.c), which allows
delayed reuse of deallocated memory.

This patch (of 7):

Rename kmalloc_large_oob_right() to kmalloc_pagealloc_oob_right(), as
the test only checks the page allocator functionality.  Also reimplement
kmalloc_large_oob_right() so that the test allocates a large enough
chunk of memory that still does not trigger the page allocator fallback.

Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: 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: Andrey Konovalov <adech.fo@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoinclude/linux/oom.h: remove undefined oom_kills_count()/note_oom_kill()
Tetsuo Handa [Fri, 25 Mar 2016 21:21:53 +0000 (14:21 -0700)]
include/linux/oom.h: remove undefined oom_kills_count()/note_oom_kill()

A leftover from commit c32b3cbe0d06 ("oom, PM: make OOM detection in the
freezer path raceless").

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agomm/page_alloc: prevent merging between isolated and other pageblocks
Vlastimil Babka [Fri, 25 Mar 2016 21:21:50 +0000 (14:21 -0700)]
mm/page_alloc: prevent merging between isolated and other pageblocks

Hanjun Guo has reported that a CMA stress test causes broken accounting of
CMA and free pages:

> Before the test, I got:
> -bash-4.3# cat /proc/meminfo | grep Cma
> CmaTotal:         204800 kB
> CmaFree:          195044 kB
>
>
> After running the test:
> -bash-4.3# cat /proc/meminfo | grep Cma
> CmaTotal:         204800 kB
> CmaFree:         6602584 kB
>
> So the freed CMA memory is more than total..
>
> Also the the MemFree is more than mem total:
>
> -bash-4.3# cat /proc/meminfo
> MemTotal:       16342016 kB
> MemFree:        22367268 kB
> MemAvailable:   22370528 kB

Laura Abbott has confirmed the issue and suspected the freepage accounting
rewrite around 3.18/4.0 by Joonsoo Kim.  Joonsoo had a theory that this is
caused by unexpected merging between MIGRATE_ISOLATE and MIGRATE_CMA
pageblocks:

> CMA isolates MAX_ORDER aligned blocks, but, during the process,
> partialy isolated block exists. If MAX_ORDER is 11 and
> pageblock_order is 9, two pageblocks make up MAX_ORDER
> aligned block and I can think following scenario because pageblock
> (un)isolation would be done one by one.
>
> (each character means one pageblock. 'C', 'I' means MIGRATE_CMA,
> MIGRATE_ISOLATE, respectively.
>
> CC -> IC -> II (Isolation)
> II -> CI -> CC (Un-isolation)
>
> If some pages are freed at this intermediate state such as IC or CI,
> that page could be merged to the other page that is resident on
> different type of pageblock and it will cause wrong freepage count.

This was supposed to be prevented by CMA operating on MAX_ORDER blocks,
but since it doesn't hold the zone->lock between pageblocks, a race
window does exist.

It's also likely that unexpected merging can occur between
MIGRATE_ISOLATE and non-CMA pageblocks.  This should be prevented in
__free_one_page() since commit 3c605096d315 ("mm/page_alloc: restrict
max order of merging on isolated pageblock").  However, we only check
the migratetype of the pageblock where buddy merging has been initiated,
not the migratetype of the buddy pageblock (or group of pageblocks)
which can be MIGRATE_ISOLATE.

Joonsoo has suggested checking for buddy migratetype as part of
page_is_buddy(), but that would add extra checks in allocator hotpath
and bloat-o-meter has shown significant code bloat (the function is
inline).

This patch reduces the bloat at some expense of more complicated code.
The buddy-merging while-loop in __free_one_page() is initially bounded
to pageblock_border and without any migratetype checks.  The checks are
placed outside, bumping the max_order if merging is allowed, and
returning to the while-loop with a statement which can't be possibly
considered harmful.

This fixes the accounting bug and also removes the arguably weird state
in the original commit 3c605096d315 where buddies could be left
unmerged.

Fixes: 3c605096d315 ("mm/page_alloc: restrict max order of merging on isolated pageblock")
Link: https://lkml.org/lkml/2016/3/2/280
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reported-by: Hanjun Guo <guohanjun@huawei.com>
Tested-by: Hanjun Guo <guohanjun@huawei.com>
Acked-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Debugged-by: Laura Abbott <labbott@redhat.com>
Debugged-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: <stable@vger.kernel.org> [3.18+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agodrivers/memstick/host/r592.c: avoid gcc-6 warning
Arnd Bergmann [Fri, 25 Mar 2016 21:21:47 +0000 (14:21 -0700)]
drivers/memstick/host/r592.c: avoid gcc-6 warning

The r592 driver relies on behavior of the DMA mapping API that is
normally observed but not guaranteed by the API.  Instead it uses a
runtime check to fail transfers if the API ever behaves

When CONFIG_NEED_SG_DMA_LENGTH is not set, one of the checks turns into a
comparison of a variable with itself, which gcc-6.0 now warns about:

drivers/memstick/host/r592.c: In function 'r592_transfer_fifo_dma':
drivers/memstick/host/r592.c:302:31: error: self-comparison always evaluates to false [-Werror=tautological-compare]
    (sg_dma_len(&dev->req->sg) < dev->req->sg.length)) {
                               ^

The check itself is not a problem, so this patch just rephrases the
condition in a way that gcc does not consider an indication of a mistake.
We already know that dev->req->sg.length was initially R592_LFIFO_SIZE, so
we can compare it to that constant again.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Maxim Levitsky <maximlevitsky@gmail.com>
Cc: Quentin Lambert <lambert.quentin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoocfs2: extend enough credits for freeing one truncate record while replaying truncate...
Xue jiufei [Fri, 25 Mar 2016 21:21:44 +0000 (14:21 -0700)]
ocfs2: extend enough credits for freeing one truncate record while replaying truncate records

Now function ocfs2_replay_truncate_records() first modifies tl_used,
then calls ocfs2_extend_trans() to extend transactions for gd and alloc
inode used for freeing clusters.  jbd2_journal_restart() may be called
and it may happen that tl_used in truncate log is decreased but the
clusters are not freed, which means these clusters are lost.  So we
should avoid extending transactions in these two operations.

Signed-off-by: joyce.xue <xuejiufei@huawei.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Acked-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoocfs2: extend transaction for ocfs2_remove_rightmost_path() and ocfs2_update_edge_len...
Xue jiufei [Fri, 25 Mar 2016 21:21:41 +0000 (14:21 -0700)]
ocfs2: extend transaction for ocfs2_remove_rightmost_path() and ocfs2_update_edge_lengths() before to avoid inconsistency between inode and et

I found that jbd2_journal_restart() is called in some places without
keeping things consistently before.  However, jbd2_journal_restart() may
commit the handle's transaction and restart another one.  If the first
transaction is committed successfully while another not, it may cause
filesystem inconsistency or read only.  This is an effort to fix this
kind of problems.

This patch (of 3):

The following functions will be called while truncating an extent:
ocfs2_remove_btree_range
  -> ocfs2_start_trans
  -> ocfs2_remove_extent
     -> ocfs2_truncate_rec
       -> ocfs2_extend_rotate_transaction
         -> jbd2_journal_restart if jbd2_journal_extend fail
       -> ocfs2_rotate_tree_left
         -> ocfs2_remove_rightmost_path
             -> ocfs2_extend_rotate_transaction
               -> ocfs2_unlink_subtree
                -> ocfs2_update_edge_lengths
                  -> ocfs2_extend_trans
                    -> jbd2_journal_restart if jbd2_journal_extend fail
  -> ocfs2_et_update_clusters
  -> ocfs2_commit_trans

jbd2_journal_restart() may be called and it may happened that the buffers
dirtied in ocfs2_truncate_rec() are committed while buffers dirtied in
ocfs2_et_update_clusters() are not, the total clusters on extent tree and
i_clusters in ocfs2_dinode is inconsistency.  So the clusters got from
ocfs2_dinode is incorrect, and it also cause read-only problem when call
ocfs2_commit_truncate() with the error message: "Inode %llu has empty
extent block at %llu".

We should extend enough credits for function ocfs2_remove_rightmost_path
and ocfs2_update_edge_lengths to avoid this inconsistency.

Signed-off-by: joyce.xue <xuejiufei@huawei.com>
Acked-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoocfs2/dlm: move lock to the tail of grant queue while doing in-place convert
xuejiufei [Fri, 25 Mar 2016 21:21:38 +0000 (14:21 -0700)]
ocfs2/dlm: move lock to the tail of grant queue while doing in-place convert

We have found a bug when two nodes doing umount one after another.

1) Node 1 migrate a lockres that has 3 locks in grant queue such as
   N2(PR)<->N3(NL)<->N4(PR) to N2.  After migration, lvb of the lock
   N3(NL) and N4(PR) are empty on node 2 because migration target do not
   copy lvb to these two lock.

2) Node 3 want to convert to PR, it can be granted in
   __dlmconvert_master(), and the order of these locks is unchanged.  The
   lvb of the lock N3(PR) on node 2 is copyed from lockres in function
   dlm_update_lvb() while the lvb of lock N4(PR) is still empty.

3) Node 2 want to leave domain, it will migrate this lockres to node 3.
   Then node 2 will trigger the BUG in dlm_prepare_lvb_for_migration()
   when adding the lock N4(PR) to mres with the following message because
   the lvb of mres is already copied from lock N3(PR), but the lvb of lock
   N4(PR) is empty.

"Mismatched lvb in lock cookie=%u:%llu, name=%.*s, node=%u"

[akpm@linux-foundation.org: tweak comment]
Signed-off-by: xuejiufei <xuejiufei@huawei.com>
Acked-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoocfs2: solve a problem of crossing the boundary in updating backups
jiangyiwen [Fri, 25 Mar 2016 21:21:35 +0000 (14:21 -0700)]
ocfs2: solve a problem of crossing the boundary in updating backups

In update_backups() there exists a problem of crossing the boundary as
follows:

we assume that lun will be resized to 1TB(cluster_size is 32kb), it will
include 0~33554431 cluster, in update_backups func, it will backup super
block in location of 1TB which is the 33554432th cluster, so the
phenomenon of crossing the boundary happens.

Signed-off-by: Yiwen Jiang <jiangyiwen@huawei.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Xue jiufei <xuejiufei@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoocfs2: fix occurring deadlock by changing ocfs2_wq from global to local
jiangyiwen [Fri, 25 Mar 2016 21:21:32 +0000 (14:21 -0700)]
ocfs2: fix occurring deadlock by changing ocfs2_wq from global to local

This patch fixes a deadlock, as follows:

  Node 1                Node 2                  Node 3
1)volume a and b are    only mount vol a        only mount vol b
  mounted

2)                      start to mount b        start to mount a

3)                      check hb of Node 3      check hb of Node 2
                        in vol a, qs_holds++    in vol b, qs_holds++

4) -------------------- all nodes' network down --------------------

5)                      progress of mount b     the same situation as
                        failed, and then call   Node 2
                        ocfs2_dismount_volume.
                        but the process is hung,
                        since there is a work
                        in ocfs2_wq cannot beo
                        completed. This work is
                        about vol a, because
                        ocfs2_wq is global wq.
                        BTW, this work which is
                        scheduled in ocfs2_wq is
                        ocfs2_orphan_scan_work,
                        and the context in this work
                        needs to take inode lock
                        of orphan_dir, because
                        lockres owner are Node 1 and
                        all nodes' nework has been down
                        at the same time, so it can't
                        get the inode lock.

6)                      Why can't this node be fenced
                        when network disconnected?
                        Because the process of
                        mount is hung what caused qs_holds
                        is not equal 0.

Because all works in the ocfs2_wq are relative to the super block.

The solution is to change the ocfs2_wq from global to local.  In other
words, move it into struct ocfs2_super.

Signed-off-by: Yiwen Jiang <jiangyiwen@huawei.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Xue jiufei <xuejiufei@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoocfs2/dlm: fix BUG in dlm_move_lockres_to_recovery_list
Joseph Qi [Fri, 25 Mar 2016 21:21:29 +0000 (14:21 -0700)]
ocfs2/dlm: fix BUG in dlm_move_lockres_to_recovery_list

When master handles convert request, it queues ast first and then
returns status.  This may happen that the ast is sent before the request
status because the above two messages are sent by two threads.  And
right after the ast is sent, if master down, it may trigger BUG in
dlm_move_lockres_to_recovery_list in the requested node because ast
handler moves it to grant list without clear lock->convert_pending.  So
remove BUG_ON statement and check if the ast is processed in
dlmconvert_remote.

Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Reported-by: Yiwen Jiang <jiangyiwen@huawei.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Tariq Saeed <tariq.x.saeed@oracle.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoocfs2/dlm: fix race between convert and recovery
Joseph Qi [Fri, 25 Mar 2016 21:21:26 +0000 (14:21 -0700)]
ocfs2/dlm: fix race between convert and recovery

There is a race window between dlmconvert_remote and
dlm_move_lockres_to_recovery_list, which will cause a lock with
OCFS2_LOCK_BUSY in grant list, thus system hangs.

dlmconvert_remote
{
        spin_lock(&res->spinlock);
        list_move_tail(&lock->list, &res->converting);
        lock->convert_pending = 1;
        spin_unlock(&res->spinlock);

        status = dlm_send_remote_convert_request();
        >>>>>> race window, master has queued ast and return DLM_NORMAL,
               and then down before sending ast.
               this node detects master down and calls
               dlm_move_lockres_to_recovery_list, which will revert the
               lock to grant list.
               Then OCFS2_LOCK_BUSY won't be cleared as new master won't
               send ast any more because it thinks already be authorized.

        spin_lock(&res->spinlock);
        lock->convert_pending = 0;
        if (status != DLM_NORMAL)
                dlm_revert_pending_convert(res, lock);
        spin_unlock(&res->spinlock);
}

In this case, check if res->state has DLM_LOCK_RES_RECOVERING bit set
(res is still in recovering) or res master changed (new master has
finished recovery), reset the status to DLM_RECOVERING, then it will
retry convert.

Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Reported-by: Yiwen Jiang <jiangyiwen@huawei.com>
Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Tariq Saeed <tariq.x.saeed@oracle.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoocfs2: fix a deadlock issue in ocfs2_dio_end_io_write()
Ryan Ding [Fri, 25 Mar 2016 21:21:23 +0000 (14:21 -0700)]
ocfs2: fix a deadlock issue in ocfs2_dio_end_io_write()

The code should call ocfs2_free_alloc_context() to free meta_ac &
data_ac before calling ocfs2_run_deallocs().  Because
ocfs2_run_deallocs() will acquire the system inode's i_mutex hold by
meta_ac.  So try to release the lock before ocfs2_run_deallocs().

Fixes: af1310367f41 ("ocfs2: fix sparse file & data ordering issue in direct io.")
Signed-off-by: Ryan Ding <ryan.ding@oracle.com>
Acked-by: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoocfs2: fix disk file size and memory file size mismatch
Ryan Ding [Fri, 25 Mar 2016 21:21:20 +0000 (14:21 -0700)]
ocfs2: fix disk file size and memory file size mismatch

When doing append direct write in an already allocated cluster, and fast
path in ocfs2_dio_get_block() is triggered, function
ocfs2_dio_end_io_write() will be skipped as there is no context
allocated.

As a result, the disk file size will not be changed as it should be.
The solution is to skip fast path when we are about to change file size.

Fixes: af1310367f41 ("ocfs2: fix sparse file & data ordering issue in direct io.")
Signed-off-by: Ryan Ding <ryan.ding@oracle.com>
Acked-by: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoocfs2: take ip_alloc_sem in ocfs2_dio_get_block & ocfs2_dio_end_io_write
Ryan Ding [Fri, 25 Mar 2016 21:21:18 +0000 (14:21 -0700)]
ocfs2: take ip_alloc_sem in ocfs2_dio_get_block & ocfs2_dio_end_io_write

Take ip_alloc_sem to prevent concurrent access to extent tree, which may
cause the extent tree in an unstable state.

Signed-off-by: Ryan Ding <ryan.ding@oracle.com>
Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoocfs2: fix ip_unaligned_aio deadlock with dio work queue
Ryan Ding [Fri, 25 Mar 2016 21:21:15 +0000 (14:21 -0700)]
ocfs2: fix ip_unaligned_aio deadlock with dio work queue

In the current implementation of unaligned aio+dio, lock order behave as
follow:

in user process context:
  -> call io_submit()
    -> get i_mutex
<== window1
      -> get ip_unaligned_aio
        -> submit direct io to block device
    -> release i_mutex
  -> io_submit() return

in dio work queue context(the work queue is created in __blockdev_direct_IO):
  -> release ip_unaligned_aio
<== window2
    -> get i_mutex
      -> clear unwritten flag & change i_size
    -> release i_mutex

There is a limitation to the thread number of dio work queue.  256 at
default.  If all 256 thread are in the above 'window2' stage, and there
is a user process in the 'window1' stage, the system will became
deadlock.  Since the user process hold i_mutex to wait ip_unaligned_aio
lock, while there is a direct bio hold ip_unaligned_aio mutex who is
waiting for a dio work queue thread to be schedule.  But all the dio
work queue thread is waiting for i_mutex lock in 'window2'.

This case only happened in a test which send a large number(more than
256) of aio at one io_submit() call.

My design is to remove ip_unaligned_aio lock.  Change it to a sync io
instead.  Just like ip_unaligned_aio lock, serialize the unaligned aio
dio.

[akpm@linux-foundation.org: remove OCFS2_IOCB_UNALIGNED_IO, per Junxiao Bi]
Signed-off-by: Ryan Ding <ryan.ding@oracle.com>
Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoocfs2: code clean up for direct io
Ryan Ding [Fri, 25 Mar 2016 21:21:12 +0000 (14:21 -0700)]
ocfs2: code clean up for direct io

Clean up ocfs2_file_write_iter & ocfs2_prepare_inode_for_write:
 * remove append dio check: it will be checked in ocfs2_direct_IO()
 * remove file hole check: file hole is supported for now
 * remove inline data check: it will be checked in ocfs2_direct_IO()
 * remove the full_coherence check when append dio: we will get the
   inode_lock in ocfs2_dio_get_block, there is no need to fall back to
   buffer io to ensure the coherence semantics.

Now the drop dio procedure is gone.  :)

[akpm@linux-foundation.org: remove unused label]
Signed-off-by: Ryan Ding <ryan.ding@oracle.com>
Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoocfs2: fix sparse file & data ordering issue in direct io
Ryan Ding [Fri, 25 Mar 2016 21:21:09 +0000 (14:21 -0700)]
ocfs2: fix sparse file & data ordering issue in direct io

There are mainly three issues in the direct io code path after commit
24c40b329e03 ("ocfs2: implement ocfs2_direct_IO_write"):

  * Does not support sparse file.
  * Does not support data ordering.  eg: when write to a file hole, it
    will alloc extent first.  If system crashed before io finished, data
    will corrupt.
  * Potential risk when doing aio+dio.  The -EIOCBQUEUED return value is
    likely to be ignored by ocfs2_direct_IO_write().

To resolve above problems, re-design direct io code with following ideas:
  * Use buffer io to fill in holes.  And this will make better
    performance also.
  * Clear unwritten after direct write finished.  So we can make sure
    meta data changes after data write to disk.  (Unwritten extent is
    invisible to user, from user's view, meta data is not changed when
    allocate an unwritten extent.)
  * Clear ocfs2_direct_IO_write().  Do all ending work in end_io.

This patch has passed fs,dio,ltp-aiodio.part1,ltp-aiodio.part2,ltp-aiodio.part4
test cases of ltp.

For performance improvement, see following test result:
ocfs2 cluster size 1MB, ocfs2 volume is mounted on /mnt/.
The original way:
  + rm /mnt/test.img -f
  + dd if=/dev/zero of=/mnt/test.img bs=4K count=1048576 oflag=direct
  1048576+0 records in
  1048576+0 records out
  4294967296 bytes (4.3 GB) copied, 1707.83 s, 2.5 MB/s
  + rm /mnt/test.img -f
  + dd if=/dev/zero of=/mnt/test.img bs=256K count=16384 oflag=direct
  16384+0 records in
  16384+0 records out
  4294967296 bytes (4.3 GB) copied, 582.705 s, 7.4 MB/s

After this patch:
  + rm /mnt/test.img -f
  + dd if=/dev/zero of=/mnt/test.img bs=4K count=1048576 oflag=direct
  1048576+0 records in
  1048576+0 records out
  4294967296 bytes (4.3 GB) copied, 64.6412 s, 66.4 MB/s
  + rm /mnt/test.img -f
  + dd if=/dev/zero of=/mnt/test.img bs=256K count=16384 oflag=direct
  16384+0 records in
  16384+0 records out
  4294967296 bytes (4.3 GB) copied, 34.7611 s, 124 MB/s

Signed-off-by: Ryan Ding <ryan.ding@oracle.com>
Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
8 years agoocfs2: record UNWRITTEN extents when populate write desc
Ryan Ding [Fri, 25 Mar 2016 21:21:06 +0000 (14:21 -0700)]
ocfs2: record UNWRITTEN extents when populate write desc

To support direct io in ocfs2_write_begin_nolock & ocfs2_write_end_nolock.

There is still one issue in the direct write procedure.

phase 1: alloc extent with UNWRITTEN flag
phase 2: submit direct data to disk, add zero page to page cache
phase 3: clear UNWRITTEN flag when data has been written to disk

When there are 2 direct write A(0~3KB),B(4~7KB) writing to the same
cluster 0~7KB (cluster size 8KB).  Write request A arrive phase 2 first,
it will zero the region (4~7KB).  Before request A enter to phase 3,
request B arrive phase 2, it will zero region (0~3KB).  This is just like
request B steps request A.

To resolve this issue, we should let request B knows this cluster is already
under zero, to prevent it from steps the previous write request.

This patch will add function ocfs2_unwritten_check() to do this job.  It
will record all clusters that are under direct write(it will be recorded
in the 'ip_unwritten_list' member of inode info), and prevent the later
direct write writing to the same cluster to do the zero work again.

Signed-off-by: Ryan Ding <ryan.ding@oracle.com>
Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>