[PATCH v2 3/4] namei: move cross-device check to __traverse_mounts

This is preparation to RESOLVE_NO_XDEV fix in following commits.
Also this commit makes LOOKUP_NO_XDEV logic more clear: now we
immediately fail with EXDEV on first mount crossing
instead of waiting for very end.

No functional change intended

Signed-off-by: Askar Safin <[email protected]>
---
 fs/namei.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 00f79559e135..c23e5a076ab3 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1489,6 +1489,10 @@ static int __traverse_mounts(struct path *path, unsigned flags, bool *jumped,
 				// here we know it's positive
 				flags = path->dentry->d_flags;
 				need_mntput = true;
+				if (unlikely(lookup_flags & LOOKUP_NO_XDEV)) {
+					ret = -EXDEV;
+					break;
+				}
 				continue;
 			}
 		}
@@ -1518,7 +1522,6 @@ static inline int traverse_mounts(struct path *path, bool *jumped,
 				  int *count, unsigned lookup_flags)
 {
 	unsigned flags = smp_load_acquire(&path->dentry->d_flags);
-	int ret;
 
 	/* fastpath */
 	if (likely(!(flags & DCACHE_MANAGED_DENTRY))) {
@@ -1527,11 +1530,7 @@ static inline int traverse_mounts(struct path *path, bool *jumped,
 			return -ENOENT;
 		return 0;
 	}
-
-	ret = __traverse_mounts(path, flags, jumped, count, lookup_flags);
-	if (*jumped && unlikely(lookup_flags & LOOKUP_NO_XDEV))
-		return -EXDEV;
-	return ret;
+	return __traverse_mounts(path, flags, jumped, count, lookup_flags);
 }
 
 int follow_down_one(struct path *path)
-- 
2.47.2