Pull f2fs updates from Jaegeuk Kim:
 "This patch series contains several performance tuning patches
  regarding to the IO submission flow, in addition to supporting new
  features such as a ZBC-base drive and multiple devices.

  It also includes some major bug fixes such as:
   - checkpoint version control
   - fdatasync-related roll-forward recovery routine
   - memory boundary or null-pointer access in corner cases
   - missing error cases

  It has various minor clean-up patches as well"

* tag 'for-f2fs-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (66 commits)
  f2fs: fix a missing size change in f2fs_setattr
  f2fs: fix to access nullified flush_cmd_control pointer
  f2fs: free meta pages if sanity check for ckpt is failed
  f2fs: detect wrong layout
  f2fs: call sync_fs when f2fs is idle
  Revert "f2fs: use percpu_counter for # of dirty pages in inode"
  f2fs: return AOP_WRITEPAGE_ACTIVATE for writepage
  f2fs: do not activate auto_recovery for fallocated i_size
  f2fs: fix to determine start_cp_addr by sbi->cur_cp_pack
  f2fs: fix 32-bit build
  f2fs: set ->owner for debugfs status file's file_operations
  f2fs: fix incorrect free inode count in ->statfs
  f2fs: drop duplicate header timer.h
  f2fs: fix wrong AUTO_RECOVER condition
  f2fs: do not recover i_size if it's valid
  f2fs: fix fdatasync
  f2fs: fix to account total free nid correctly
  f2fs: fix an infinite loop when flush nodes in cp
  f2fs: don't wait writeback for datas during checkpoint
  f2fs: fix wrong written_valid_blocks counting
  ...

Thread A		Thread B		Thread C
- f2fs_create
 - f2fs_new_inode
  - f2fs_lock_op
   - alloc_nid
    alloc last nid
  - f2fs_unlock_op
			- f2fs_create
			 - f2fs_new_inode
			  - f2fs_lock_op
			   - alloc_nid
			    as node count still not
			    be increased, we will
			    loop in alloc_nid
						- f2fs_write_node_pages
						 - f2fs_balance_fs_bg
						  - f2fs_sync_fs
						   - write_checkpoint
						    - block_operations
						     - f2fs_lock_all
 - f2fs_lock_op

While creating new inode, we do not allocate and account nid atomically,
so that when there is almost no free nids left, we may encounter deadloop
like above stack.

In order to avoid that, reuse nm_i::available_nids for accounting free nids
and make nid allocation and counting being atomical during node creation.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Thread A			Thread B

- write_checkpoint
 - block_operations
   -blk_start_plug
    -sync_node_pages		- f2fs_do_sync_file
				 - fsync_node_pages
				  - f2fs_wait_on_page_writeback

Thread A wait for global F2FS_DIRTY_NODES decreased to zero,
it start a plug list, some requests have been added to this list.
Thread B lock one dirty node page, and wait this page write back.
But this page has been in plug list of thread A with PG_writeback flag.
Thread A keep on running and its plug list has no chance to finish,
so it seems a deadlock between cp and fsync path.

This patch add a wait on page write back before set node page dirty
to avoid this problem.

Signed-off-by: Yunlei He <heyunlei@huawei.com>
Signed-off-by: Pengyang Hou <houpengyang@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

We don't need to allocate bio partially in order to maximize sequential writes.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch avoids build warning.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Let build_free_nids support sync/async methods, in allocation flow of nids,
we use synchronuous method, so that we can avoid looping in alloc_nid when
free memory is low; in unblock_operations and f2fs_balance_fs_bg we use
asynchronuous method in where low memory condition can interrupt us.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch cleans up to use consistent free nid list ops.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

During free nid allocation, in order to do preallocation, we will tag free
nid entry as allocated one and still leave it in free nid list, for other
allocators who want to grab free nids, it needs to traverse the free nid
list for lookup. It becomes overhead in scenario of allocating free nid
intensively by multithreads.

This patch splits free nid list to two list: {free,alloc}_nid_list, to
keep free nids and preallocated free nids separately, after that, traverse
latency will be gone, besides split nid_cnt for separate statistic.

Additionally, introduce __insert_nid_to_list and __remove_nid_from_list for
cleanup.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
[Jaegeuk Kim: modify f2fs_bug_on to avoid needless branches]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs contained a number of endianness conversion bugs.

Also, one function should have been 'static'.

Found with sparse by running 'make C=2 CF=-D__CHECK_ENDIAN__ fs/f2fs/'

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

In fsync_node_pages, if f2fs was taged with CP_ERROR_FLAG, make sure bio
cache was flushed before return.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>