xfs: create a predicate to determine if two xfs_names are the same

Create a simple predicate to determine if two xfs_names are the same
objects or have the exact same name.  The comparison is always case
sensitive.

Signed-off-by: Darrick J. Wong <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>

2 files changed, 14 insertions, 2 deletions

diff --git a/fs/xfs/libxfs/xfs_dir2.h b/fs/xfs/libxfs/xfs_dir2.h
index 7d7cd8d808e4..8497d041f316 100644
--- a/fs/xfs/libxfs/xfs_dir2.h
+++ b/fs/xfs/libxfs/xfs_dir2.h
@@ -24,6 +24,18 @@ struct xfs_dir3_icleaf_hdr;
 extern const struct xfs_name	xfs_name_dotdot;
 extern const struct xfs_name	xfs_name_dot;
 
+static inline bool
+xfs_dir2_samename(
+	const struct xfs_name	*n1,
+	const struct xfs_name	*n2)
+{
+	if (n1 == n2)
+		return true;
+	if (n1->len != n2->len)
+		return false;
+	return !memcmp(n1->name, n2->name, n1->len);
+}
+
 /*
  * Convert inode mode to directory entry filetype
  */
diff --git a/fs/xfs/scrub/dir.c b/fs/xfs/scrub/dir.c
index d86ab51af928..076a310b8eb0 100644
--- a/fs/xfs/scrub/dir.c
+++ b/fs/xfs/scrub/dir.c
@@ -93,11 +93,11 @@ xchk_dir_actor(
 		return -ECANCELED;
 	}
 
-	if (!strncmp(".", name->name, name->len)) {
+	if (xfs_dir2_samename(name, &xfs_name_dot)) {
 		/* If this is "." then check that the inum matches the dir. */
 		if (ino != dp->i_ino)
 			xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
-	} else if (!strncmp("..", name->name, name->len)) {
+	} else if (xfs_dir2_samename(name, &xfs_name_dotdot)) {
 		/*
 		 * If this is ".." in the root inode, check that the inum
 		 * matches this dir.