Now new interface ->rename2() is added to VFS, here are related description:
https://lkml.org/lkml/2014/2/7/873
https://lkml.org/lkml/2014/2/7/758

This patch adds function f2fs_rename2() to support ->rename2() including
handling both RENAME_EXCHANGE and RENAME_NOREPLACE flag.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Otherwise, if a large amount of direct IO writes were done, the
segment allocation may be failed because no enough segments are gced.

Changes:

v2: add f2fs_balance_fs into __get_data_block instead of f2fs_direct_IO.
Signed-off-by: Huang, Ying <ying.huang@intel.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

In __set_test_and_free we will check whether all segment are free in one section
When free one segment, in order to set section to free status.
But the searching region of segmap is from start segno to last segno of f2fs,
it's not necessary. So let's just only check all segment bitmap of target
section.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

We assume that modification of some special application could result in zeroed
name_len, or it is consciously made by somebody. We will deadloop in
find_in_block when name_len of dir entry is zero.

This patch is added for preventing deadloop in above scenario.

change log from v1:
 o use f2fs_bug_on rather than break out from searching dir entry suggested by
Jaegeuk Kim.

Jaegeuk describe:
"Well, IMO, it would be good to add f2fs_bug_on() here with a specific comment.
In the current phase of f2fs, it is more important to investigate the file
system bugs, rather than workarounds for any corrupted images.
And, definitely it needs to stop the kernel if any corrupted image was mounted,
so that we can figure out where the bugs are occurred."
Suggested-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

In this patch we use below inner macro and function to clean up codes.
1. ADDRS_PER_PAGE
2. SM_I
3. f2fs_readonly
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

When we fail in ->write_begin()/->direct_IO(), our allocated node block in disk
and page cache are still kept, despite these may not be used again.

This patch introduce f2fs_write_failed() to handle the error case of these two
interfaces, it will truncate page cache and blocks of this file according to
i_size.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

kernel side(xx_init_acl), the acl is get/cloned from the parent dir's,
which is credible. So remove the redundant validation check of acl
here.
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

In our rename process, region of f2fs_lock_op covered is too big as some of the
code like f2fs_empty_dir/f2fs_find_entry are not needed to protect by this lock.

So in the extreme case like doing checkpoint when we rename old inode to exist
inode in a large directory could cause lower concurrency.

Let's reduce the region of f2fs_lock_op to fix this.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

kcalloc manages count*sizeof overflow.

Cc: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Cc: linux-f2fs-devel@lists.sourceforge.net
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Although building NAT journal in cursum reduce the read/write work for NAT
block, but previous design leave us lower performance when write checkpoint
frequently for these cases:
1. if journal in cursum has already full, it's a bit of waste that we flush all
   nat entries to page for persistence, but not to cache any entries.
2. if journal in cursum is not full, we fill nat entries to journal util
   journal is full, then flush the left dirty entries to disk without merge
   journaled entries, so these journaled entries may be flushed to disk at next
   checkpoint but lost chance to flushed last time.

In this patch we merge dirty entries located in same NAT block to nat entry set,
and linked all set to list, sorted ascending order by entries' count of set.
Later we flush entries in sparse set into journal as many as we can, and then
flush merged entries to disk. In this way we can not only gain in performance,
but also save lifetime of flash device.

In my testing environment, it shows this patch can help to reduce NAT block
writes obviously. In hard disk test case: cost time of fsstress is stablely
reduced by about 5%.

1. virtual machine + hard disk:
fsstress -p 20 -n 200 -l 5
		node num	cp count	nodes/cp
based		4599.6		1803.0		2.551
patched		2714.6		1829.6		1.483

2. virtual machine + 32g micro SD card:
fsstress -p 20 -n 200 -l 1 -w -f chown=0 -f creat=4 -f dwrite=0
-f fdatasync=4 -f fsync=4 -f link=0 -f mkdir=4 -f mknod=4 -f rename=5
-f rmdir=5 -f symlink=0 -f truncate=4 -f unlink=5 -f write=0 -S

		node num	cp count	nodes/cp
based		84.5		43.7		1.933
patched		49.2		40.0		1.23

Our latency of merging op shows not bad when handling extreme case like:
merging a great number of dirty nats:
latency(ns)	dirty nat count
3089219		24922
5129423		27422
4000250		24523

change log from v1:
 o fix wrong logic in add_nat_entry when grab a new nat entry set.
 o swith to create slab cache in create_node_manager_caches.
 o use GFP_ATOMIC instead of GFP_NOFS to avoid potential long latency.

change log from v2:
 o make comment position more appropriate suggested by Jaegeuk Kim.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch cleans up simple unnecessary codes.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch adds f2fs_do_tmpfile to eliminate the redundant init_inode_metadata
flow.
Throught this, we can provide the consistent lock usage, e.g., fi->i_sem,  and
this will enable better debugging stuffs.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Add function f2fs_tmpfile() to support O_TMPFILE file creation, and modify logic
of init_inode_metadata to enable linkat temp file.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

After we call find_data_page in truncate_partial_data_page, we could not
guarantee this page is updated or not as error may occurred in lower layer.

We'd better check status of the page to avoid this no updated page be
writebacked to device.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

We have already set page update in ->write_begin, so we should remove redundant
SetPageUptodate in ->write_end.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Pull f2fs bugfixes from Jaegeuk Kim:
 "This includes a couple of bug fixes found by xfstests.  In addition,
  one critical bug was reported by Brian Chadwick, which is falling into
  the infinite loop in balance_dirty_pages.  And it turned out due to
  the IO merging policy in f2fs, which was newly merged in 3.16.

   - fix normal and recovery path for fallocated regions
   - fix error case mishandling
   - recover renamed fsync inodes correctly
   - fix to get out of infinite loops in balance_dirty_pages
   - fix kernel NULL pointer error"

* tag 'f2fs-fixes-3.16' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs:
  f2fs: avoid to access NULL pointer in issue_flush_thread
  f2fs: check bdi->dirty_exceeded when trying to skip data writes
  f2fs: do checkpoint for the renamed inode
  f2fs: release new entry page correctly in error path of f2fs_rename
  f2fs: fix error path in init_inode_metadata
  f2fs: check lower bound nid value in check_nid_range
  f2fs: remove unused variables in f2fs_sm_info
  f2fs: fix not to allocate unnecessary blocks during fallocate
  f2fs: recover fallocated data and its i_size together
  f2fs: fix to report newly allocate region as extent

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=75861

Denis 2014-05-10 11:28:59 UTC reported:
"F2FS-fs (mmcblk0p28): mounting..
 Unable to handle kernel NULL pointer dereference at virtual address 00000018
 ...
 [<c0a2f678>] (_raw_spin_lock+0x3c/0x70) from [<c03a0330>] (issue_flush_thread+0x50/0x17c)
 [<c03a0330>] (issue_flush_thread+0x50/0x17c) from [<c01b4064>] (kthread+0x98/0xa4)
 [<c01b4064>] (kthread+0x98/0xa4) from [<c0108060>] (kernel_thread_exit+0x0/0x8)"

This patch assign cmd_control_info in sm_info before issue_flush_thread is being
created, so this make sure that issue flush thread will have no chance to access
invalid info in fcc.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Reviewed-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

If we don't check the current backing device status, balance_dirty_pages can
fall into infinite pausing routine.

This can be occurred when a lot of directories make a small number of dirty
dentry pages including files.
Reported-by: Brian Chadwick <brianchad@westnet.com.au>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

If an inode is renamed, it should be registered as file_lost_pino to conduct
checkpoint at f2fs_sync_file.
Otherwise, the inode cannot be recovered due to no dent_mark in the following
scenario.

Note that, this scenario is from xfstests/322.

1. create "a"
2. fsync "a"
3. rename "a" to "b"
4. fsync "b"
5. Sudden power-cut

After recovery is done, "b" should be seen.
However, the result shows "a", since the recovery procedure does not enter
recover_dentry due to no dent_mark.

The reason is like below.
- The nid of "a" is checkpointed during #2, f2fs_sync_file.
- The inode page for "b" produced by #3 is written without dent_mark by
sync_node_pages.

So, this patch fixes this bug by assinging file_lost_pino to the "a"'s inode.
If the pino is lost, f2fs_sync_file conducts checkpoint, and then recovers
the latest pino and its dentry information for further recovery.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch correct releasing code of new_page to avoid BUG_ON in error patch of
f2fs_rename.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

If we fail in this path:
->init_inode_metadata
  ->make_empty_dir
    ->get_new_data_page
      ->grab_cache_page return -ENOMEM

We will bug on in error path of init_inode_metadata when call remove_inode_page
because i_block = 2 (one inode block will be released later & one dentry block).

We should release the dentry block in init_inode_metadata to avoid this BUG_ON,
and avoid leak of dentry block resource, because we never have second chance to
release that block in ->evict_inode as in upper error path we make this inode
'bad'.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch add lower bound verification for nid in check_nid_range, so nids
reserved like 0, node, meta passed by caller could be checked there.

And then check_nid_range could be used in f2fs_nfs_get_inode for simplifying
code.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Remove unused variables in struct f2fs_sm_info.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Pull hwmon fixes from Guenter Roeck:
 "Fix a number of zero-day bugs, mostly found with module test scripts.
  Nothing major, but potentially annoying and worthwhile to fix"

* tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: (adc128d818) Drop write support on inX_input attributes
  hwmon: (emc2103) Clamp limits instead of bailing out
  hwmon: (adm1031) Fix writes to limit registers
  hwmon: (adm1021) Fix cache problem when writing temperature limits
  hwmon: (adm1029) Ensure the fan_div cache is updated in set_fan_div
  hwmon: (amc6821) Fix permissions for temp2_input
  hwmon: (ntc_thermistor) Correct information printed during probe

Pull thermal fixes from Zhang Rui:
 "Specifics:

   - update Email address of Thermal subsystem maintainer Eduardo
     Valentin.

   - fix a problem that unloading thermal module results in kernel crash
     because a non-exist device file is removed on thermal unload.

   - fix a problem that critical trip point is set wrongly on latest
     i.MX6 SOC and results in system critical shutdown.

   - a couple of fixes to Tmon tool, of-thermal code and ti thermal
     driver"

* 'for-rc' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux:
  tmon: set umask to a reasonable value
  tmon: Check log file for common secuirty issues
  tools/thermal: tmon: fix compilation errors when building statically
  thermal: ti-soc-thermal: ti-bandgap.c: Cleaning up wrong address is checked
  Thermal: imx: correct critical trip temperature setting
  thermal: Bind cooling devices with the correct arguments
  thermal: Add braces around suspect code
  thermal: hwmon: Make the check for critical temp valid consistent
  MAINTAINERS: Update Eduardo Valentin's email address

Pull HID fixes from Jiri Kosina:
 "A few tiny HID subsystem fixes for 3.16"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
  HID: use multi input quirk for 22b9:2968
  HID: sensor-hub: fix potential memory leak
  HID: usbhid: quirk for PM1610 and PM1640 Touchscreen.
  HID: rmi: Protect PM-only functions by #ifdef CONFIG_PM
  HID: sensor-hub: introduce Kconfig dependency on IOMEM
  HID: sensor-hub: make dyn_callback_lock IRQ-safe

Pull pin control fixes from Linus Walleij:
 "Two fixes for the pin control subsystem, both relating to the error
  path in probe()

  I'm a bit snowed under by mail but these have boiled in linux-next and
  should propagate to you"

* tag 'pinctrl-v3.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl:
  pinctrl: berlin: fix an error code in berlin_pinctrl_probe()
  pinctrl: sunxi: Fix potential null pointer dereference

Writes into input registers doesn't make sense, even more so since
the writes actually ended up writing into the maximum limit registers.
Drop it.

Cc: stable@vger.kernel.org
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

It is customary to clamp limits instead of bailing out with an error
if a configured limit is out of the range supported by the driver.
This simplifies limit configuration, since the user will not typically
know chip and/or driver specific limits.
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Cc: stable@vger.kernel.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

This device generates ABS_Z and ABS_RX events instead of ABS_X and
ABS_Y.
Signed-off-by: Wen-chien Jesse Sung <jesse.sung@canonical.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

Upper limit for write operations to temperature limit registers
was clamped to a fractional value. However, limit registers do
not support fractional values. As a result, upper limits of 127.5
degrees C or higher resulted in a rounded limit of 128 degrees C.
Since limit registers are signed, this was stored as -128 degrees C.
Clamp limits to (-55, +127) degrees C to solve the problem.

Value on writes to auto_temp[12]_min and auto_temp[12]_max were not
clamped at all, but masked. As a result, out-of-range writes resulted
in a more or less arbitrary limit. Clamp those attributes to (0, 127)
degrees C for more predictable results.

Cc: Axel Lin <axel.lin@ingics.com>
Cc: stable@vger.kernel.org
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Pull devicetree bugfix from Grant Likely:
 "Important bug fix for parsing 64-bit addresses on 32-bit platforms.
  Without this patch the kernel will try to use memory ranges that
  cannot be reached"

* tag 'dt-for-linus' of git://git.secretlab.ca/git/linux:
  of: Check for phys_addr_t overflows in early_init_dt_add_memory_arch

Pull SCSI fixes from James Bottomley:
 "This is a set of 13 fixes, a MAINTAINERS update and a sparse update.
  The fixes are mostly correct value initialisations, avoiding NULL
  derefs and some uninitialised pointer avoidance.

  All the patches have been incubated in -next for a few days.  The
  final patch (use the scsi data buffer length to extract transfer size)
  has been rebased to add a cc to stable, but only the commit message
  has changed"

* tag 'scsi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  [SCSI] use the scsi data buffer length to extract transfer size
  virtio-scsi: fix various bad behavior on aborted requests
  virtio-scsi: avoid cancelling uninitialized work items
  ibmvscsi: Add memory barriers for send / receive
  ibmvscsi: Abort init sequence during error recovery
  qla2xxx: Fix sparse warning in qla_target.c.
  bnx2fc: Improve stats update mechanism
  bnx2fc: do not scan uninitialized lists in case of error.
  fc: ensure scan_work isn't active when freeing fc_rport
  pm8001: Fix potential null pointer dereference and memory leak.
  MAINTAINERS: Update LSILOGIC MPT FUSION DRIVERS (FC/SAS/SPI) maintainers Email IDs
  be2iscsi: remove potential junk pointer free
  be2iscsi: add an missing goto in error path
  scsi_error: set DID_TIME_OUT correctly
  scsi_error: fix invalid setting of host byte

Pull drm fixes from Dave Airlie:
 "i915, tda998x and vmwgfx fixes,

  The main one is i915 fix for missing VGA connectors, along with some
  fixes for the tda998x from Russell fixing some modesetting problems.

  (still on holidays, but got a spare moment to find these)"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
  drm/vmwgfx: Fix incorrect write to read-only register v2:
  drm/i915: Drop early VLV WA to fix Voltage not getting dropped to Vmin
  drm/i915: only apply crt_present check on VLV
  drm/i915: Wait for vblank after enabling the primary plane on BDW
  drm/i2c: tda998x: add some basic mode validation
  drm/i2c: tda998x: faster polling for edid
  drm/i2c: tda998x: move drm_i2c_encoder_destroy call

Pull ARM SoC fixes from Olof Johansson:
 "This week's arm-soc fixes:

   - A set of of OMAP patches that we had missed Tony's pull request of:
     * Reset fix for am43xx
     * Proper OPP table for omap5
     * Fix for SoC detection of one of the DRA7 SoCs
     * hwmod updates to get SATA and OCP to work on omap5 (drivers
       merged in 3.16)
     * ... plus a handful of smaller fixes
   - sunxi needed to re-add machine specific restart code that was
     removed in anticipation of a watchdog driver being merged for 3.16,
     and it didn't make it in.
   - Marvell fixes for PCIe on SMP and a big-endian fix.
   - A trivial defconfig update to make my capri test board boot with
     bcm_defconfig again.

  ... and a couple of MAINTAINERS updates, one to claim new Keystone
  drivers that have been merged, and one to merge MXS and i.MX (both
  Freescale platforms).

  The largest diffs come from the hwmod code for omap5 and the re-add of
  the restart code on sunxi.  The hwmod stuff is quite late at this
  point but it slipped through cracks repeatedly while coming up the
  maintainer chain and only affects the one SoC so risk is low"

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  MAINTAINERS: Add few more Keystone drivers
  MAINTAINERS: merge MXS entry into IMX one
  ARM: sunxi: Reintroduce the restart code for A10/A20 SoCs
  ARM: mvebu: fix cpuidle implementation to work on big-endian systems
  ARM: mvebu: update L2/PCIe deadlock workaround after L2CC cleanup
  ARM: mvebu: move Armada 375 external abort logic as a quirk
  ARM: bcm: Fix bcm and multi_v7 defconfigs
  ARM: dts: dra7-evm: remove interrupt binding
  ARM: OMAP2+: Fix parser-bug in platform muxing code
  ARM: DTS: dra7/dra7xx-clocks: ATL related changes
  ARM: OMAP2+: drop unused function
  ARM: dts: am43x-epos-evm: Add Missing cpsw-phy-sel for am43x-epos-evm
  ARM: dts: omap5: Update CPU OPP table as per final production Manual
  ARM: DRA722: add detection of SoC information
  ARM: dts: Enable twl4030 off-idle configuration for selected omaps
  ARM: OMAP5: hwmod: Add ocp2scp3 and sata hwmods
  ARM: OMAP2+: hwmod: Change hardreset soc_ops for AM43XX