[PATCH v2 02/31] ocfs2: abstract the zero nlink or mode dinode check

[Joseph Qi]

ocfs2_validate_inode_block() open-codes the test for a dinode that has
no links or no mode.  Fold the condition into a predicate so it reads
like the neighbouring ocfs2_dinode_has_*() helpers, and so the filecheck
variant can share it.

Reuse ocfs2_read_links_count() rather than testing i_links_count and
i_links_count_hi separately.  OCFS2_LINKS_HI_SHIFT is 16 and both fields
are 16 bits wide, so the combined count is zero exactly when both raw
fields are zero.

The OCFS2_ORPHANED_FL carve-out moves into the predicate along with the
rest of the condition, in the same early-return style as
ocfs2_dinode_has_size_without_clusters().

The return code and the log message stay at the call site: filecheck
reports the same conditions with a different code and must not call
ocfs2_error().

No functional change intended.

Signed-off-by: Joseph Qi <joseph.qi@xxxxxxxxxxxxxxxxx>
---
 fs/ocfs2/inode.c | 25 ++++++++++++++++---------
 1 file changed, 16 insertions(+), 9 deletions(-)

diff --git a/fs/ocfs2/inode.c b/fs/ocfs2/inode.c
index 371857673712..209066321932 100644
--- a/fs/ocfs2/inode.c
+++ b/fs/ocfs2/inode.c
@@ -67,6 +67,21 @@ static int ocfs2_filecheck_validate_inode_block(struct super_block *sb,
 static int ocfs2_filecheck_repair_inode_block(struct super_block *sb,
 						      struct buffer_head *bh);
 
+static bool ocfs2_dinode_has_zero_nlink_or_mode(struct ocfs2_dinode *di)
+{
+	/*
+	 * An open-unlinked inode legitimately has a zero link count on disk:
+	 * ocfs2_unlink() drops the last link and ocfs2_orphan_add() sets
+	 * OCFS2_ORPHANED_FL, while OCFS2_VALID_FL is only cleared later by
+	 * ocfs2_remove_inode().  DIO orphans keep their link count, so they
+	 * need no exemption here.
+	 */
+	if (le32_to_cpu(di->i_flags) & OCFS2_ORPHANED_FL)
+		return false;
+
+	return !ocfs2_read_links_count(di) || !di->i_mode;
+}
+
 static bool ocfs2_valid_inode_mode(umode_t mode)
 {
 	return fs_umode_to_ftype(mode) != FT_UNKNOWN;
@@ -1482,15 +1497,7 @@ int ocfs2_validate_inode_block(struct super_block *sb,
 		goto bail;
 	}
 
-	/*
-	 * An open-unlinked inode legitimately has a zero link count on disk:
-	 * ocfs2_unlink() drops the last link and ocfs2_orphan_add() sets
-	 * OCFS2_ORPHANED_FL, while OCFS2_VALID_FL is only cleared later by
-	 * ocfs2_remove_inode().  DIO orphans keep their link count, so they
-	 * need no exemption here.
-	 */
-	if (!(le32_to_cpu(di->i_flags) & OCFS2_ORPHANED_FL) &&
-	    ((!di->i_links_count && !di->i_links_count_hi) || !di->i_mode)) {
+	if (ocfs2_dinode_has_zero_nlink_or_mode(di)) {
 		mlog(ML_ERROR, "Invalid dinode #%llu: "
 			"Corrupt state (nlink = %u or mode = %u) detected!\n",
 		        (unsigned long long)bh->b_blocknr,
-- 
2.39.3