Pull ext4 updates from Ted Ts'o:
- Convert content from the ext4 wiki to Documentation rst files so it
is more likely to be updated as we add new features to ext4.
- Add 64-bit timestamp support to ext4's superblock fields.
- ... and the usual bug fixes and cleanups, including a Spectre gadget
fixup and some hardening against maliciously corrupted file systems.
* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (34 commits)
ext4: remove unneeded variable "err" in ext4_mb_release_inode_pa()
ext4: improve code readability in ext4_iget()
ext4: fix spectre gadget in ext4_mb_regular_allocator()
ext4: check for NUL characters in extended attribute's name
ext4: use ext4_warning() for sb_getblk failure
ext4: fix race when setting the bitmap corrupted flag
ext4: reset error code in ext4_find_entry in fallback
ext4: handle layout changes to pinned DAX mappings
dax: dax_layout_busy_page() warn on !exceptional
docs: fix up the obviously obsolete bits in the new ext4 documentation
docs: add new ext4 superblock time extension fields
docs: create filesystem internal section
ext4: use swap macro in mext_page_double_lock
ext4: check allocation failure when duplicating "data" in ext4_remount()
ext4: fix warning message in ext4_enable_quotas()
ext4: super: extend timestamps to 40 bits
jbd2: replace current_kernel_time64 with ktime equivalent
ext4: use timespec64 for all inode times
ext4: use ktime_get_real_seconds for i_dtime
ext4: use 64-bit timestamps for mmp_time
...