This patch makes f2fs_map_blocks supporting returning next potential
page offset which skips hole region in indirect tree of inode, and
use it to speed up fiemap in handling big hole case.

Test method:
xfs_io -f /mnt/f2fs/file  -c "pwrite 1099511627776 4096"
time xfs_io -f /mnt/f2fs/file -c "fiemap -v"

Before:
time xfs_io -f /mnt/f2fs/file -c "fiemap -v"
/mnt/f2fs/file:
 EXT: FILE-OFFSET              BLOCK-RANGE      TOTAL FLAGS
   0: [0..2147483647]:         hole             2147483648
   1: [2147483648..2147483655]: 81920..81927         8   0x1

real    3m3.518s
user    0m0.000s
sys     3m3.456s

After:
time xfs_io -f /mnt/f2fs/file -c "fiemap -v"
/mnt/f2fs/file:
 EXT: FILE-OFFSET              BLOCK-RANGE      TOTAL FLAGS
   0: [0..2147483647]:         hole             2147483648
   1: [2147483648..2147483655]: 81920..81927         8   0x1

real    0m0.008s
user    0m0.000s
sys     0m0.008s
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

When seeking data in ->llseek, if we encounter a big hole which covers
several dnode pages, we will try to seek data from index of page which
is the first page of next dnode page, at most we could skip searching
(ADDRS_PER_BLOCK - 1) pages.

However it's still not efficient, because if our indirect/double-indirect
pointer are NULL, there are no dnode page locate in the tree indirect/
double-indirect pointer point to, it's not necessary to search the whole
region.

This patch introduces get_next_page_offset to calculate next page offset
based on current searching level and max searching level returned from
get_dnode_of_data, with this, we could skip searching the entire area
indirect or double-indirect node block is not exist.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

There are redundant pointer conversion in following call stack:
 - at position a, inode was been converted to f2fs_file_info.
 - at position b, f2fs_file_info was been converted to inode again.

 - truncate_blocks(inode,..)
  - fi = F2FS_I(inode)		---a
  - ADDRS_PER_PAGE(node_page, fi)
   - addrs_per_inode(fi)
    - inode = &fi->vfs_inode	---b
    - f2fs_has_inline_xattr(inode)
     - fi = F2FS_I(inode)
     - is_inode_flag_set(fi,..)

In order to avoid unneeded conversion, alter ADDRS_PER_PAGE and
addrs_per_inode to acept parameter with type of inode pointer.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch uses existing function f2fs_map_block to simplify implementation
of __allocate_data_blocks.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

In f2fs_map_blocks, we use duplicated codes to handle first block mapping
and the following blocks mapping, it's unnecessary. This patch simplifies
f2fs_map_blocks to avoid using copied codes.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch introduces lifetime IO write statistics exposed to the sysfs interface.
The write IO amount is obtained from block layer, accumulated in the file system and
stored in the hot node summary of checkpoint.
Signed-off-by: Shuoran Liu <liushuoran@huawei.com>
Signed-off-by: Pengyang Hou <houpengyang@huawei.com>
[Jaegeuk Kim: add sysfs documentation]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

It needs to give a chance to be rescheduled while shrinking slab entries.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

On the worst case, we need to scan the whole radix tree and every rb-tree to
free the victimed extent_nodes when shrinking.

Pengyang initially introduced a victim_list to record the victimed extent_nodes,
and free these extent_nodes by just scanning a list.

Later, Chao Yu enhances the original patch to improve memory footprint by
removing victim list.

The policy of lru list shrinking becomes:
1) lock lru list's lock
2) trylock extent tree's lock
3) remove extent node from lru list
4) unlock lru list's lock
5) do shrink
6) repeat 1) to 5)
Signed-off-by: Hou Pengyang <houpengyang@huawei.com>
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

If en has empty list pointer, it will be freed sooner, so we don't need to
set cached_en with it.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch moves extent_node list operations to be handled together with
its rbtree operations.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

There are three steps to free an extent node:
1) list_del_init, 2)__detach_extent_node, 3) kmem_cache_free

In path f2fs_destroy_extent_tree, 1->2->3 to free a node,
But in path f2fs_update_extent_tree_range, it is 2->1->3.

This patch makes all the order to be: 1->2->3
It makes sense, since in the next patch, we import a victim list in the
path shrink_extent_tree, we could check if the extent_node is in the victim
list by checking the list_empty(). So it is necessary to put 1) first.
Signed-off-by: Hou Pengyang <houpengyang@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

We need to use wq_has_sleeper including smp_mb to consider cp_wait concurrency.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

variable nsearched in get_victim_by_default() indicates the number of
dirty segments we already checked. There are 2 problems about the way
it updates:
1. When p.ofs_unit is greater than 1, the victim we find consists
   of multiple segments, possibly more than 1 dirty segment.
   But nsearched always increases by 1.
2. If segments have been found but not been chosen, nsearched won't
   increase. So even we have checked all dirty segments, nsearched
   may still less than p.max_search.
All these problems could cause unnecessary search after all dirty
segments have already been checked.
Signed-off-by: Fan li <fanofcode.li@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

no need to wait inline file page writeback for no one
use it, so this patch delete unnecessary wait.
Signed-off-by: Yunlei He <heyunlei@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

In write_begin, if storage supports stable_page, we don't need to wait for
writeback to update its contents.
This patch introduces to use wait_for_stable_page instead of
wait_on_page_writeback.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

If we configure section consist of multiple segments, foreground GC will
do the garbage collection with following approach:

	for each segment in victim section
		blk_start_plug
		for each valid block in segment
			write out by OPU method
		submit bio cache   <---
		blk_finish_plug   <---

There are two issue:
1) for most of the time, 'submit bio cache' will break the merging in
current bio buffer from writes of next segments, making a smaller bio
submitting.
2) block plug only cover IO submitting in one segment, which reduce
opportunity of merging IOs in plug with multiple segments.

So refactor the code as below structure to strive for biggest
opportunity of merging IOs:

	blk_start_plug
	for each segment in victim section
		for each valid block in segment
			write out by OPU method
	submit bio cache
	blk_finish_plug

Test method:
1. mkfs.f2fs -s 8 /dev/sdX
2. touch 32 files
3. write 2M data into each file
4. punch 1.5M data from offset 0 for each file
5. trigger foreground gc through ioctl

Before patch, there are totoally 40 bios submitted.
f2fs_submit_write_bio: dev = (8,32), WRITE_SYNC, DATA, sector = 65536, size = 122880
f2fs_submit_write_bio: dev = (8,32), WRITE_SYNC, DATA, sector = 65776, size = 122880
f2fs_submit_write_bio: dev = (8,32), WRITE_SYNC, DATA, sector = 66016, size = 122880
f2fs_submit_write_bio: dev = (8,32), WRITE_SYNC, DATA, sector = 66256, size = 122880
f2fs_submit_write_bio: dev = (8,32), WRITE_SYNC, DATA, sector = 66496, size = 32768
----repeat for 8 times

After patch, there are totally 35 bios submitted.
f2fs_submit_write_bio: dev = (8,32), WRITE_SYNC, DATA, sector = 65536, size = 122880
----repeat 34 times
f2fs_submit_write_bio: dev = (8,32), WRITE_SYNC, DATA, sector = 73696, size = 16384
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

If end_io gets an error, we don't need to set the page as dirty, since we
already set f2fs_stop_checkpoint which will not flush any data.

This will resolve the following warning.

======================================================
[ INFO: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected ]
4.4.0+ #9 Tainted: G           O
------------------------------------------------------
xfs_io/26773 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
 (&(&sbi->inode_lock[i])->rlock){+.+...}, at: [<ffffffffc025483f>] update_dirty_page+0x6f/0xd0 [f2fs]

and this task is already holding:
 (&(&q->__queue_lock)->rlock){-.-.-.}, at: [<ffffffff81396ea2>] blk_queue_bio+0x422/0x490
which would create a new lock dependency:
 (&(&q->__queue_lock)->rlock){-.-.-.} -> (&(&sbi->inode_lock[i])->rlock){+.+...}
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

In write_begin, if there is an inline_data, f2fs loads it into 0'th data page.
Since it's the read path, we don't need to sync its inode page.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

In write_end, we don't need to sync inode page at every time.
Instead, we can expect f2fs_write_inode will update later.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

The sceanrio is:
1. create fully node blocks
2. flush node blocks
3. write inline_data for all the node blocks again
4. flush node blocks redundantly

So, this patch tries to flush inline_data when flushing node blocks.
Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

We should consider data block allocation to trigger f2fs_balance_fs.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

The scenario is:
1. create lots of node blocks
2. sync
3. write lots of inline_data
-> got panic due to no free space

In that case, we should flush node blocks when writing inline_data in #3,
and trigger gc as well.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

If there are many writepages calls by multiple threads in background, we don't
need to serialize to merge all the bios, since it's background.
In such the case, it'd better to run writepages concurrently.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch removes needless condition variable.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

get_new_segment starts from current segment position, tries to search a
free segment among its right neighbors locate in same section.

But previously our search area was set as [current segment, max segment],
which means we have to search to more bits in free_segmap bitmap for some
worse cases. So here we correct the search area to [current segment, last
segment in section] to avoid unnecessary searching.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch exports a new sysfs entry 'dirty_nat_ratio' to control threshold
of dirty nat entries, if current ratio exceeds configured threshold,
checkpoint will be triggered in f2fs_balance_fs_bg for flushing dirty nats.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

When testing f2fs with xfstest, generic/251 is stuck for long time,
the case uses below serials to obtain fresh released space in device,
in order to prepare for following fstrim test.

1. rm -rf /mnt/dir
2. mkdir /mnt/dir/
3. cp -axT `pwd`/ /mnt/dir/
4. goto 1

During preparing step, all nat entries will be cached in nat cache,
most of them are dirty entries with invalid blkaddr, which means
nodes related to these entries have been truncated, and they could
be reused after the dirty entries been checkpointed.

However, there was no checkpoint been triggered, so nid allocators
(e.g. mkdir, creat) will run into long journey of iterating all NAT
pages, looking for free nids in alloc_nid->build_free_nids.

Here, in f2fs_balance_fs_bg we give another chance to do checkpoint
to flush nat entries for reusing them in free nid cache when dirty
entry count exceeds 10% of max count.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Operations in is_merged_page is related to inner bio cache, move it to
data.c.
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Merge tag 'trace-fixes-v4.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Two more small fixes.

  One is by Yang Shi who added a READ_ONCE_NOCHECK() to the scan of the
  stack made by the stack tracer.  As the stack tracer scans the entire
  kernel stack, KASAN triggers seeing it as a "stack out of bounds"
  error.  As the scan is looking at the contents of the stack from
  parent functions.  The NOCHECK() tells KASAN that this is done on
  purpose, and is not some kind of stack overflow.

  The second fix is to the ftrace selftests, to retrieve the PID of
  executed commands from the shell with '$!' and not by parsing 'jobs'"

* tag 'trace-fixes-v4.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing, kasan: Silence Kasan warning in check_stack of stack_tracer
  ftracetest: Fix instance test to use proper shell command for pids

Pull xen bug fixes from David Vrabel:

 - Two scsiback fixes (resource leak and spurious warning).

 - Fix DMA mapping of compound pages on arm/arm64.

 - Fix some pciback regressions in MSI-X handling.

 - Fix a pcifront crash due to some uninitialize state.

* tag 'for-linus-4.5-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/pcifront: Fix mysterious crashes when NUMA locality information was extracted.
  xen/pcifront: Report the errors better.
  xen/pciback: Save the number of MSI-X entries to be copied later.
  xen/pciback: Check PF instead of VF for PCI_COMMAND_MEMORY
  xen: fix potential integer overflow in queue_reply
  xen/arm: correctly handle DMA mapping of compound pages
  xen/scsiback: avoid warnings when adding multiple LUNs to a domain
  xen/scsiback: correct frontend counting

Pull networking fixes from David Miller:
 "Looks like a lot, but mostly driver fixes scattered all over as usual.

  Of note:

   1) Add conditional sched in nf conntrack in cleanup to avoid NMI
      watchdogs.  From Florian Westphal.

   2) Fix deadlock in nfnetlink cttimeout, also from Floarian.

   3) Fix handling of slaves in bonding ARP monitor validation, from Jay
      Vosburgh.

   4) Callers of ip_cmsg_send() are responsible for freeing IP options,
      some were not doing so.  Fix from Eric Dumazet.

   5) Fix per-cpu bugs in mvneta driver, from Gregory CLEMENT.

   6) Fix vlan handling in mv88e6xxx DSA driver, from Vivien Didelot.

   7) bcm7xxx PHY driver bug fixes from Florian Fainelli.

   8) Avoid unaligned accesses to protocol headers wrt.  GRE, from
      Alexander Duyck.

   9) SKB leaks and other problems in arc_emac driver, from Alexander
      Kochetkov.

  10) tcp_v4_inbound_md5_hash() releases listener socket instead of
      request socket on error path, oops.  Fix from Eric Dumazet.

  11) Missing socket release in pppoe_rcv_core() that seems to have
      existed basically forever.  From Guillaume Nault.

  12) Missing slave_dev unregister in dsa_slave_create() error path,
      from Florian Fainelli.

  13) crypto_alloc_hash() never returns NULL, fix return value check in
      __tcp_alloc_md5sig_pool.  From Insu Yun.

  14) Properly expire exception route entries in ipv4, from Xin Long.

  15) Fix races in tcp/dccp listener socket dismantle, from Eric
      Dumazet.

  16) Don't set IFF_TX_SKB_SHARING in vxlan, geneve, or GRE, it's not
      legal.  These drivers modify the SKB on transmit.  From Jiri Benc.

  17) Fix regression in the initialziation of netdev->tx_queue_len.
      From Phil Sutter.

  18) Missing unlock in tipc_nl_add_bc_link() error path, from Insu Yun.

  19) SCTP port hash sizing does not properly ensure that table is a
      power of two in size.  From Neil Horman.

  20) Fix initializing of software copy of MAC address in fmvj18x_cs
      driver, from Ken Kawasaki"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (129 commits)
  bnx2x: Fix 84833 phy command handler
  bnx2x: Fix led setting for 84858 phy.
  bnx2x: Correct 84858 PHY fw version
  bnx2x: Fix 84833 RX CRC
  bnx2x: Fix link-forcing for KR2
  net: ethernet: davicom: fix devicetree irq resource
  fmvj18x_cs: fix incorrect indexing of dev->dev_addr[] when copying the MAC address
  Driver: Vmxnet3: Update Rx ring 2 max size
  net: netcp: rework the code for get/set sw_data in dma desc
  soc: ti: knav_dma: rename pad in struct knav_dma_desc to sw_data
  net: ti: netcp: restore get/set_pad_info() functionality
  MAINTAINERS: Drop myself as xen netback maintainer
  sctp: Fix port hash table size computation
  can: ems_usb: Fix possible tx overflow
  Bluetooth: hci_core: Avoid mixing up req_complete and req_complete_skb
  net: bcmgenet: Fix internal PHY link state
  af_unix: Don't use continue to re-execute unix_stream_read_generic loop
  unix_diag: fix incorrect sign extension in unix_lookup_by_ino
  bnxt_en: Failure to update PHY is not fatal condition.
  bnxt_en: Remove unnecessary call to update PHY settings.
  ...

Merge tag 'hwmon-for-linus-v4.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging

Pull hwmon fixes from Guenter Roeck:
 "Two fixes headed for stable:

   - Remove an unnecessary speed_index lookup for thermal hook in the
     gpio-fan driver.  The unnecessary speed lookup can hog the system.

   - Handle negative conversion values correctly in the ads1015 driver"

* tag 'hwmon-for-linus-v4.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: (gpio-fan) Remove un-necessary speed_index lookup for thermal hook
  hwmon: (ads1015) Handle negative conversion values correctly

Pull rdma fixes from Doug Ledford:
 "One ocrdma fix:

   - The new CQ API support was added to ocrdma, but they got the arming
     logic wrong, so without this, transfers eventually fail when they
     fail to arm the interrupt properly under load

  Two related fixes for mlx4:

   - When we added the 64bit extended counters support to the core IB
     code, they forgot to update the RoCE side of the mlx4 driver (the
     IB side they properly updated).

     I debated whether or not to include these patches as they could be
     considered feature enablement patches, but the existing code will
     blindy copy the 32bit counters, whether any counters were requested
     at all (a bug).

     These two patches make it (a) check to see that counters were
     requested and (b) copy the right counters (the 64bit support is
     new, the 32bit is not).  For that reason I went ahead and took
     them"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma:
  IB/mlx4: Add support for the port info class for RoCE ports
  IB/mlx4: Add support for extended counters over RoCE ports
  RDMA/ocrdma: Fix arm logic to align with new cq API

Pull i2c fixes from Wolfram Sang:
 "Some bugfixes from I2C for you:

  A fix for a RuntimePM regression with OMAP, a fix to enable TCO for
  Lewisburg platforms, and a typo fix while we are here"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: i801: Adding Intel Lewisburg support for iTCO
  i2c: uniphier: fix typos in error messages
  i2c: omap: Fix PM regression with deferred probe for pm_runtime_reinit

Merge tag 'linux-can-fixes-for-4.5-20160221' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can

Marc Kleine-Budde says:

====================
pull-request: can 2016-02-21

this is a pull reqeust of one patch for net/master.

The patch is by Gerhard Uttenthaler and fixes a potential tx overflow in the
ems_usb driver.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Yuval Mintz says:

====================
bnx2x: Fix 848xx phys

This series contains link-related fixes, mostly for the 848xx phys
[2 patches are for 84833, and 2 patches are for 84858].
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Current initialization sequence is lacking, causing some configurations
to fail.
Signed-off-by: Yuval Mintz <Yuval.Mintz@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Yuval Mintz <Yuval.Mintz@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The phy's firmware version isn't being parsed properly as it's
currently parsed like the rest of the 848xx phys.
Signed-off-by: Yuval Mintz <Yuval.Mintz@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

There's a problem in current 84833 phy configuration -
in case 1Gb link is configured and jumbo-sized packets are being
used, device will experience RX crc errors.
Signed-off-by: Yuval Mintz <Yuval.Mintz@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>