When background gc is off, the only way to trigger gc is executing
a force gc in some operations who wants to grab space in disk.

The executing condition is limited: to execute force gc, we should
wait for the time when there is almost no more free section for LFS
allocation. This seems not reasonable for our user who wants to
control triggering gc by himself.

This patch introduces F2FS_IOC_GARBAGE_COLLECT interface for
triggering garbage collection by using ioctl. It provides our users
one more option to trigger gc.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch moves extent cache related code from data.c into extent_cache.c
since extent cache is independent feature, and its codes are not relate to
others in data.c, it's better for us to maintain them in separated place.

There is no functionality change, but several small coding style fixes
including:
* rename __drop_largest_extent to f2fs_drop_largest_extent for exporting;
* rename misspelled word 'untill' to 'until';
* remove unneeded 'return' in the end of f2fs_destroy_extent_tree().
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Since only parts of extents longer than F2FS_MIN_EXTENT_LEN will
be kept in extent cache after split, extents already shorter than
F2FS_MIN_EXTENT_LEN don't need to try split at all.
Signed-off-by: Fan Li <fanofcode.li@samsung.com>
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch fixes to update page flag (e.g. Uptodate/cold flag) in
->write_begin.

Otherwise, page will be non-uptodate when we try to write entire
page, and cold data flag in page will not be clean when gced page
is being rewritten.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

If an extent_tree entry has a zero reference count, we can drop it from the
cache in higher priority rather than currently referencing entries.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

In ->writepages, we use writepages mutex lock to serialize all block
address allocation and page submitting pairs from different inodes.
This method makes our delayed dirty pages of one inode being written
continously as many as possible.

But there is one problem that we did not submit current cached bio in
protection region of writepages mutex lock, so there is a small chance
that we submit the one of other thread's as below, resulting in
splitting more bios.

thread 1			thread 2
->writepages
  lock(writepages)
  ->write_cache_pages
  unlock(writepages)
				  lock(writepages)
				  ->write_cache_pages
  ->f2fs_submit_merged_bio
				    ->writepage
				  unlock(writepages)

fs_mark-6535  [002] ....  2242.270230: f2fs_submit_write_bio: dev = (1,0), WRITE_SYNC, DATA, sector = 5766152, size = 524288
fs_mark-6536  [000] ....  2242.270361: f2fs_submit_write_bio: dev = (1,0), WRITE_SYNC, DATA, sector = 5767176, size = 4096
fs_mark-6536  [000] ....  2242.270370: f2fs_submit_write_bio: dev = (1,0), WRITE_SYNC, NODE, sector = 8138112, size = 4096
fs_mark-6535  [002] ....  2242.270776: f2fs_submit_write_bio: dev = (1,0), WRITE_SYNC, DATA, sector = 5767184, size = 516096

This may really increase time of block layer works, and may cause
larger IO lantency.

This patch moves the submitting operation into region of writepages
mutex lock to avoid bio splits when concurrently writebacking is
intensive.

my test environment: virtual machine,
intel cpu i5 2500, 8GB size memory, 4GB size ramdisk

time fs_mark  -t  16  -L  1  -s  524288  -S  1  -d  /mnt/f2fs/

before:
real	0m4.244s
user	0m0.088s
sys	0m12.336s

after:
real	0m3.822s
user	0m0.072s
sys	0m10.760s
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

When testing with fs_mark, some blocks were written out as cold
data which were mixed with warm data, resulting in splitting more
bios.

This is because fs_mark will create file with random filename as
below:

559551ee~~~~~~~~15Z29OCC05JCKQP60JQ42MKV
559551ee~~~~~~~~NZAZ6X8OA8LHIIP6XD0L58RM
559551ef~~~~~~~~B15YDSWAK789HPSDZKYTW6WM
559551f1~~~~~~~~2DAE5DPS79785BUNTFWBEMP3
559551f1~~~~~~~~1MYDY0BKSQCJPI32Q8C514RM
559551f1~~~~~~~~YQOTMAOMN5CVRFOUNI026MP4
559551f3~~~~~~~~1WF42LPRTQJNPPGR3EINKMPE
559551f3~~~~~~~~8Y2NRK7CEPPAA02LY936PJPG

They are regarded as cold file since their filename are ended with
multimedia files' extension, but this should be wrong as we only
match the extension of filename, not the whole one.

In this patch, we try to fix the format of multimedia filename to:
"filename + '.' + extension", then we set cold file only its
filename matches the format.

So after this change, it will reduce the probability we set the
wrong cold file, also it helps a little for fs_mark's performance
on f2fs.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch adds missed trace file in maintainer-ship of f2fs,
so it completes the description of files maintained in f2fs,
and also it allows people to find correct mailing list by using
get_maintainer.pl when only patching the trace file of f2fs.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This makes the function check_dnode have a return type of bool
due to this particular function only ever returning either one
or zero as its return value and changes the name of the function
to is_alive in order to better explain this function's intended
work of checking if a dnode is still in use by the filesystem.
Signed-off-by: Nicholas Krause <xerofoify@gmail.com>
[Jaegeuk Kim: change the return value check for the renamed function]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Because of the extent shrinker or other -ENOMEM scenarios, it cannot guarantee
that the largest extent would be cached in the tree all the time.

Instead of relying on extent_tree, we can simply check the cached one in extent
tree accordingly.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

We don't need to handle the duplicate extent information.

The integrated rule is:
 - update on-disk extent with largest one tracked by in-memory extent_cache
 - destroy extent_tree for the truncation case
 - drop per-inode extent_cache by shrinker
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch adds noextent_cache mount option.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch registers shrinking extent_caches.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch registers shrinking nat_cache entries.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch introduces a shrinker targeting to reduce memory footprint consumed
by a number of in-memory f2fs data structures.

In addition, it newly adds:
 - sbi->umount_mutex to avoid data races on shrinker and put_super
 - sbi->shruinker_run_no to not revisit objects

Note that the basic implementation was copied from fs/ubifs/shrinker.c
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch relocates cached_en not only to be covered by spin_lock, but also
to set once after checking out completely.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Previously, f2fs_update_extent_cache() updates in-memory extent_cache all the
time, and then finally preserves its up-to-date extent into on-disk one during
f2fs_evict_inode.

But, in the following scenario:

1. mount
2. open & write an extent X
3. f2fs_evict_inode; on-disk extent is X
4. open & update the extent X with Y
5. sync; trigger checkpoint
6. power-cut

after power-on, f2fs should serve extent Y, but we have an on-disk extent X.

This causes a failure on xfstests/311.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch fixes wrong calculation on block address field when an extent is
split.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

For newly added fallocate types, it should convert inline_data before handling
block swapping.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Before iput is called, the inode number used by a bad inode can be reassigned
to other new inode, resulting in any abnormal behaviors on the new inode.
This should not happen for the new inode.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

The write_checkpoint can update stat information, so we should destroy the stat
structure after it.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Dirty page can be exist in mapping of newly created symlink, but previously
we did not maintain the counting of dirty page for symlink like we maintained
for regular/directory, so the counting we lookuped should be wrong.

This patch adds missed dirty page counting for symlink to fix this issue.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

The key_put() function 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>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Pull PCI fix from Bjorn Helgaas:
 "This is a trivial fix for a change that broke user program compilation
  (QEMU in this case)"

* tag 'pci-v4.2-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  PCI: Restore PCI_MSIX_FLAGS_BIRMASK definition

Pull drm mst fixes from Daniel Vetter:
 "Special pull request for mst fixes since most of the patches touch
  code outside of i915 proper.  DRM parts have also been reviewed by
  Thierry (nvidia) since Dave's enjoying vacations"

* tag 'topic/mst-fixes-2015-08-04' of git://anongit.freedesktop.org/drm-intel:
  drm/atomic-helpers: Make encoder picking more robust
  drm/dp-mst: Remove debug WARN_ON
  drm/i915: Fixup dp mst encoder selection
  drm/atomic-helper: Add an atomice best_encoder callback

Pull xen bug fixes from David Vrabel:

 - don't lose interrupts when offlining CPUs

 - fix gntdev oops during unmap

 - drop the balloon lock occasionally to allow domain create/destroy

* tag 'for-linus-4.2-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/events/fifo: Handle linked events when closing a port
  xen: release lock occasionally during ballooning
  xen/gntdevt: Fix race condition in gntdev_release()

An event channel bound to a CPU that was offlined may still be linked
on that CPU's queue.  If this event channel is closed and reused,
subsequent events will be lost because the event channel is never
unlinked and thus cannot be linked onto the correct queue.

When a channel is closed and the event is still linked into a queue,
ensure that it is unlinked before completing.

If the CPU to which the event channel bound is online, spin until the
event is handled by that CPU. If that CPU is offline, it can't handle
the event, so clear the event queue during the close, dropping the
events.

This fixes the missing interrupts (and subsequent disk stalls etc.)
when offlining a CPU.
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

Pull kbuild fixes from Michal Marek:
 "Two fixes for kbuild:

   - The new ARCH_{CPP,A,C}FLAGS variables are reset before including
     the arch Makefile

   - Fix calling make modules_install twice when module compression is
     enabled"

* 'rc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  Makefile: Force gzip and xz on module install
  kbuild: Do not pick up ARCH_{CPP,A,C}FLAGS from the environment

We've had a few issues with atomic where subtle bugs in the encoder
picking logic lead to accidental self-stealing of the encoder,
resulting in a NULL connector_state->crtc in update_connector_routing
and subsequent.

Linus applied some duct-tape for an mst regression in

commit 27667f47
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date:   Wed Jul 29 22:18:16 2015 -0700

    i915: temporary fix for DP MST docking station NULL pointer dereference

But that was incomplete (the code will still oops when debuggin is
enabled) and mangled the state even further. So instead WARN and bail
out as the more future-proof option.

Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Ander Conselvan de Oliveira <conselvan2@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>

Apparently been in there since forever and fairly easy to hit when
hotplugging really fast. I can do that since my mst hub has a manual
button to flick the hpd line for reprobing. The resulting WARNING spam
isn't pretty.

Cc: Dave Airlie <airlied@gmail.com>
Cc: stable@vger.kernel.org
Reviewed-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Ander Conselvan de Oliveira <conselvan2@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>

In

commit 8c7b5ccb
Author: Ander Conselvan de Oliveira <ander.conselvan.de.oliveira@intel.com>
Date:   Tue Apr 21 17:13:19 2015 +0300

    drm/i915: Use atomic helpers for computing changed flags

we've switched over to the atomic version to compute the
crtc->encoder->connector routing from the i915 variant. That one
relies upon the ->best_encoder callback, but the i915-private version
relied upon intel_find_encoder. Which didn't matter except for dp mst,
where the encoder depends upon the selected crtc.

Fix this functional bug by implemented a correct atomic-state based
encoder selector for dp mst.

Note that we can't get rid of the legacy best_encoder callback since
the fbdev emulation uses that still. That means it's incorrect there
still, but that's been the case ever since i915 dp mst support was
merged so not a regression. Best to fix that by converting fbdev over
to atomic too.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Ander Conselvan de Oliveira <conselvan2@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>

With legacy helpers all the routing was already set up when calling
best_encoder and so could be inspected. But with atomic it's staged,
hence we need a new atomic compliant callback for drivers which need
to inspect the requested state and can't just decided the best encoder
statically.

This is needed to fix up i915 dp mst where we need to pick the right
encoder depending upon the requested CRTC for the connector.

v2: Don't forget to amend the kerneldoc

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Acked-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Ander Conselvan de Oliveira <conselvan2@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>

Pull i2c fixes from Wolfram Sang:
 "A refcounting bugfix for the i2c-core, bugfixes for the generic bus
  recovery algorithm and for its omap-user, making binary file
  attributes for EEPROMs behave POSIX compliant, and a small typo fix
  while we are here"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: fix leaked device refcount on of_find_i2c_* error path
  i2c: Fix typo in i2c-bfin-twi.c
  i2c: omap: fix bus recovery setup
  i2c: core: only use set_scl for bus recovery after calling prepare_recovery
  misc: eeprom: at24: clean up at24_bin_write()
  i2c: slave eeprom: clean up sysfs bin attribute read()/write()

Pull Ceph fixes from Sage Weil:
 "There are two critical regression fixes for CephFS from Zheng, and an
  RBD completion fix for layered images from Ilya"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  rbd: fix copyup completion race
  ceph: always re-send cap flushes when MDS recovers
  ceph: fix ceph_encode_locks_to_buffer()

Pull security layer fix from James Morris:
 "Yama initialization fix"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  Adding YAMA hooks also when YAMA is not stacked.

Pull crypto fixes from Herbert Xu:
 "This fixes the following issues:

   - a bogus BUG_ON in ixp4xx that can be triggered by a dst buffer that
     is an SG list.

   - the error handling in hwrngd may cause a crash in case of an error.

   - fix a race condition in qat registration when multiple devices are
     present"

* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  hwrng: core - correct error check of kthread_run call
  crypto: ixp4xx - Remove bogus BUG_ON on scattered dst buffer
  crypto: qat - Fix invalid synchronization between register/unregister sym algs

Pull module fix from Rusty Russell:
 "Single overzealous locking assertion fix"

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  module: weaken locking assertion for oops path.

Without this patch YAMA will not work at all if it is chosen
as the primary LSM instead of being "stacked".
Signed-off-by: Salvatore Mesoraca <s.mesoraca16@gmail.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <james.l.morris@oracle.com>

Pull powerpc fixes from Michael Ellerman:
 - TCE table memory calculation fix from Alexey
 - Build fix for ans-lcd from Luis
 - Unbalanced IRQ warning fix from Alistair

* tag 'powerpc-4.2-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/eeh-powernv: Fix unbalanced IRQ warning
  macintosh/ans-lcd: fix build failure after module_init/exit relocation
  powerpc/powernv/ioda2: Fix calculation for memory allocated for TCE table