f2fs: updates on v4.16-rc1

Pull f2fs updates from Jaegeuk Kim:
 "In this round, we've followed up to support some generic features such
  as cgroup, block reservation, linking fscrypt_ops, delivering
  write_hints, and some ioctls. And, we could fix some corner cases in
  terms of power-cut recovery and subtle deadlocks.

  Enhancements:
   - bitmap operations to handle NAT blocks
   - readahead to improve readdir speed
   - switch to use fscrypt_*
   - apply write hints for direct IO
   - add reserve_root=%u,resuid=%u,resgid=%u to reserve blocks for root/uid/gid
   - modify b_avail and b_free to consider root reserved blocks
   - support cgroup writeback
   - support FIEMAP_FLAG_XATTR for fibmap
   - add F2FS_IOC_PRECACHE_EXTENTS to pre-cache extents
   - add F2FS_IOC_{GET/SET}_PIN_FILE to pin LBAs for data blocks
   - support inode creation time

  Bug fixs:
   - sysfile-based quota operations
   - memory footprint accounting
   - allow to write data on partial preallocation case
   - fix deadlock case on fallocate
   - fix to handle fill_super errors
   - fix missing inode updates of fsync'ed file
   - recover renamed file which was fsycn'ed before
   - drop inmemory pages in corner error case
   - keep last_disk_size correctly
   - recover missing i_inline flags during roll-forward

  Various clean-up patches were added as well"

Cherry-pick from origin/upstream-f2fs-stable-linux-4.9.y:

71f8f049 f2fs: support inode creation time
58dc6f6f f2fs: rebuild sit page from sit info in mem
6393cef3 f2fs: stop issuing discard if fs is readonly
742bc90e f2fs: clean up duplicated assignment in init_discard_policy
cfabb6ed f2fs: use GFP_F2FS_ZERO for cleanup
111e8456 f2fs: allow to recover node blocks given updated checkpoint
36e041a5 f2fs: recover some i_inline flags
3127a7b6 f2fs: correct removexattr behavior for null valued extended attribute
86f78c1e f2fs: drop page cache after fs shutdown
1a3b0047 f2fs: stop gc/discard thread after fs shutdown
62a91a5a f2fs: hanlde error case in f2fs_ioc_shutdown
66356ee5 f2fs: split need_inplace_update
5912fbae f2fs: fix to update last_disk_size correctly
3aa46e2c f2fs: kill F2FS_INLINE_XATTR_ADDRS for cleanup
acdaca27 f2fs: clean up error path of fill_super
cf882111 f2fs: avoid hungtask when GC encrypted block if io_bits is set
4be98c98 f2fs: allow quota to use reserved blocks
2a6489c8 f2fs: fix to drop all inmem pages correctly
fd214422 f2fs: speed up defragment on sparse file
6bce9632 f2fs: support F2FS_IOC_PRECACHE_EXTENTS
9ce3d6bb f2fs: add an ioctl to disable GC for specific file
9ef5e656 f2fs: prevent newly created inode from being dirtied incorrectly
08ddb191 f2fs: support FIEMAP_FLAG_XATTR
aa9c1c10 f2fs: fix to cover f2fs_inline_data_fiemap with inode_lock
92b8f9c7 f2fs: check node page again in write end io
4992a3ca f2fs: fix to caclulate required free section correctly
d1a6b4f6 f2fs: handle newly created page when revoking inmem pages
462d762b f2fs: add resgid and resuid to reserve root blocks
cbd5e5af f2fs: implement cgroup writeback support
5a584742 f2fs: remove unused pend_list_tag
37d4ca7c f2fs: avoid high cpu usage in discard thread
02cfdab8 f2fs: make local functions static
5fee5409 f2fs: add reserved blocks for root user
26597463 f2fs: check segment type in __f2fs_replace_block
4f76d6ac f2fs: update inode info to inode page for new file
52b45281 f2fs: show precise # of blocks that user/root can use
ae0e1fa5 f2fs: clean up unneeded declaration
8fc74466 f2fs: continue to do direct IO if we only preallocate partial blocks
162464df f2fs: enable quota at remount from r to w
e270976f f2fs: skip stop_checkpoint for user data writes
d0473692 f2fs: fix missing error number for xattr operation
211cb7bb f2fs: recover directory operations by fsync
2648e735 f2fs: return error during fill_super
e2a0518d f2fs: fix an error case of missing update inode page
bf1750ba f2fs: fix potential hangtask in f2fs_trace_pid
c804fcf3 f2fs: no need return value in restore summary process
fdd41a87 f2fs: use unlikely for release case
a74690b0 f2fs: don't return value in truncate_data_blocks_range
987892cc f2fs: clean up f2fs_map_blocks
d7714cb2 f2fs: clean up hash codes
e3d2a1e9 f2fs: fix error handling in fill_super
b02e72d2 f2fs: spread f2fs_k{m,z}alloc
ead5259d f2fs: inject fault to kvmalloc
e585ca29 f2fs: inject fault to kzalloc
8234ed56 f2fs: remove a redundant conditional expression
1a9d6a9c f2fs: apply write hints to select the type of segment for direct write
955e7f58 f2fs: switch to fscrypt_prepare_setattr()
268c7f60 f2fs: switch to fscrypt_prepare_lookup()
8dfa646f f2fs: switch to fscrypt_prepare_rename()
d5382ccb f2fs: switch to fscrypt_prepare_link()
3ccc177c f2fs: switch to fscrypt_file_open()
8b5674ef f2fs: remove repeated f2fs_bug_on
ba4556cd f2fs: remove an excess variable
46accc92 f2fs: fix lock dependency in between dio_rwsem & i_mmap_sem
8933908c f2fs: remove unused parameter
76b6e8ed f2fs: still write data if preallocate only partial blocks
1ed75339 f2fs: introduce sysfs readdir_ra to readahead inode block in readdir
4e68a15e f2fs: fix concurrent problem for updating free bitmap
9be6e759 f2fs: remove unneeded memory footprint accounting
923df752 f2fs: no need to read nat block if nat_block_bitmap is set
09234be2 f2fs: reserve nid resource for quota sysfile

Signed-off-by: Jaegeuk Kim <jaegeuk@google.com>