Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

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
  ...

1 files changed, 9 insertions, 1 deletions

diff --git a/fs/dax.c b/fs/dax.c
index 641192808bb6..897b51e41d8f 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -566,7 +566,8 @@ struct page *dax_layout_busy_page(struct address_space *mapping)
 			if (index >= end)
 				break;
 
-			if (!radix_tree_exceptional_entry(pvec_ent))
+			if (WARN_ON_ONCE(
+			     !radix_tree_exceptional_entry(pvec_ent)))
 				continue;
 
 			xa_lock_irq(&mapping->i_pages);
@@ -578,6 +579,13 @@ struct page *dax_layout_busy_page(struct address_space *mapping)
 			if (page)
 				break;
 		}
+
+		/*
+		 * We don't expect normal struct page entries to exist in our
+		 * tree, but we keep these pagevec calls so that this code is
+		 * consistent with the common pattern for handling pagevecs
+		 * throughout the kernel.
+		 */
 		pagevec_remove_exceptionals(&pvec);
 		pagevec_release(&pvec);
 		index++;