f2fs/fscrypt: updates to v4.17-rc1

Pull f2fs update from Jaegeuk Kim:
 "In this round, we've mainly focused on performance tuning and critical
  bug fixes occurred in low-end devices. Sheng Yong introduced
  lost_found feature to keep missing files during recovery instead of
  thrashing them. We're preparing coming fsverity implementation. And,
  we've got more features to communicate with users for better
  performance. In low-end devices, some memory-related issues were
  fixed, and subtle race condtions and corner cases were addressed as
  well.

  Enhancements:
   - large nat bitmaps for more free node ids
   - add three block allocation policies to pass down write hints given by user
   - expose extension list to user and introduce hot file extension
   - tune small devices seamlessly for low-end devices
   - set readdir_ra by default
   - give more resources under gc_urgent mode regarding to discard and cleaning
   - introduce fsync_mode to enforce posix or not
   - nowait aio support
   - add lost_found feature to keep dangling inodes
   - reserve bits for future fsverity feature
   - add test_dummy_encryption for FBE

  Bug fixes:
   - don't use highmem for dentry pages
   - align memory boundary for bitops
   - truncate preallocated blocks in write errors
   - guarantee i_times on fsync call
   - clear CP_TRIMMED_FLAG correctly
   - prevent node chain loop during recovery
   - avoid data race between atomic write and background cleaning
   - avoid unnecessary selinux violation warnings on resgid option
   - GFP_NOFS to avoid deadlock in quota and read paths
   - fix f2fs_skip_inode_update to allow i_size recovery

  In addition to the above, there are several minor bug fixes and clean-ups"

Cherry-pick from origin/upstream-f2fs-stable-linux-4.4.y:

42bf67fc f2fs: remain written times to update inode during fsync
6cb5aa02 f2fs: make assignment of t->dentry_bitmap more readable
a8d07f1f f2fs: truncate preallocated blocks in error case
86444d60 f2fs: fix a wrong condition in f2fs_skip_inode_update
db2188a6 f2fs: reserve bits for fs-verity
ee2e74b3 f2fs: Add a segment type check in inplace write
0192e0a4 f2fs: no need to initialize zero value for GFP_F2FS_ZERO
49338842 f2fs: don't track new nat entry in nat set
d6a69d5e f2fs: clean up with F2FS_BLK_ALIGN
2c8834a7 f2fs: check blkaddr more accuratly before issue a bio
6ab573a9 f2fs: Set GF_NOFS in read_cache_page_gfp while doing f2fs_quota_read
7419dcb8 f2fs: introduce a new mount option test_dummy_encryption
9321e22c f2fs: introduce F2FS_FEATURE_LOST_FOUND feature
8a571961 f2fs: release locks before return in f2fs_ioc_gc_range()
739ace13 f2fs: align memory boundary for bitops
4c55abe4 f2fs: remove unneeded set_cold_node()
30654507 f2fs: add nowait aio support
d909e941 f2fs: wrap all options with f2fs_sb_info.mount_opt
5738be52 f2fs: Don't overwrite all types of node to keep node chain
0bdeb167 f2fs: introduce mount option for fsync mode
6bc490f0 f2fs: fix to restore old mount option in ->remount_fs
0c9c3e03 f2fs: wrap sb_rdonly with f2fs_readonly
6c661122 f2fs: avoid selinux denial on CAP_SYS_RESOURCE
076a6f32 f2fs: support hot file extension
58edcdbc f2fs: fix to avoid race in between atomic write and background GC
1e0aeb0a f2fs: do gc in greedy mode for whole range if gc_urgent mode is set
10b2d001 f2fs: issue discard aggressively in the gc_urgent mode
a5052f32 f2fs: set readdir_ra by default
1aa536a6 f2fs: add auto tuning for small devices
0ffdffc8 f2fs: add mount option for segment allocation policy
b7982989 f2fs: don't stop GC if GC is contended
766d2321 f2fs: expose extension_list sysfs entry
98b329de f2fs: fix to set KEEP_SIZE bit in f2fs_zero_range
4d409fa3 f2fs: introduce sb_lock to make encrypt pwsalt update exclusive
1f6bac14 f2fs: remove redundant initialization of pointer 'p'
946aefc7 f2fs: flush cp pack except cp pack 2 page at first
e5081a52 f2fs: clean up f2fs_sb_has_xxx functions
a2924771 f2fs: remove redundant check of page type when submit bio
190e64a8 f2fs: fix to handle looped node chain during recovery
889d9808 f2fs: handle quota for orphan inodes
92b12bb1 f2fs: support passing down write hints to block layer with F2FS policy
22fa74c2 f2fs: support passing down write hints given by users to block layer
18090037 f2fs: fix to clear CP_TRIMMED_FLAG
0671fae1 f2fs: support large nat bitmap
eceb943d f2fs: fix to check extent cache in f2fs_drop_extent_tree
2e2a339c f2fs: restrict inline_xattr_size configuration
41dda116 f2fs: fix heap mode to reset it back
39575737 f2fs: fix potential corruption in area before F2FS_SUPER_OFFSET
7e0e7995 fscrypt: fix build with pre-4.6 gcc versions
31d3279a fscrypt: fix up fscrypt_fname_encrypted_size() for internal use
82bec888 fscrypt: define fscrypt_fname_alloc_buffer() to be for presented names
168a9078 fscrypt: calculate NUL-padding length in one place only
042ae9f4 fscrypt: move fscrypt_symlink_data to fscrypt_private.h
f9550c24 fscrypt: remove fscrypt_fname_usr_to_disk()
7ac4756a f2fs: switch to fscrypt_get_symlink()
6b76f58e f2fs: switch to fscrypt ->symlink() helper functions
fd457d2c fscrypt: new helper function - fscrypt_get_symlink()
a1cdacb7 fscrypt: new helper functions for ->symlink()
7f43602f fscrypt: trim down fscrypt.h includes
d9cadc11 fscrypt: move fscrypt_is_dot_dotdot() to fs/crypto/fname.c
e6fe9305 fscrypt: move fscrypt_valid_enc_modes() to fscrypt_private.h
efefa434 fscrypt: move fscrypt_operations declaration to fscrypt_supp.h
7ed178bc fscrypt: split fscrypt_dummy_context_enabled() into supp/notsupp versions
3f16e09d fscrypt: move fscrypt_ctx declaration to fscrypt_supp.h
8216a0b5 fscrypt: move fscrypt_info_cachep declaration to fscrypt_private.h
dfe0b3b1 fscrypt: move fscrypt_control_page() to supp/notsupp headers
3a2c7917 fscrypt: move fscrypt_has_encryption_key() to supp/notsupp headers

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