cifs: return ENOENT for DFS lookup_cache_entry()

EEXIST didn't make sense to use when dfs_cache_find() couldn't find a
cache entry nor retrieve a referral target.

It also doesn't make sense cifs_dfs_query_info_nonascii_quirk() to
emulate ENOENT anymore.
Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/cifs/connect.c

@@ -3420,8 +3420,9 @@ cifs_are_all_path_components_accessible(struct TCP_Server_Info *server,
 }
 
 /*
- * Check if path is remote (e.g. a DFS share). Return -EREMOTE if it is,
- * otherwise 0.
+ * Check if path is remote (i.e. a DFS share).
+ *
+ * Return -EREMOTE if it is, otherwise 0 or -errno.
  */
 static int is_path_remote(struct mount_ctx *mnt_ctx)
 {
@@ -3711,6 +3712,7 @@ int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
 	if (!isdfs)
 		goto out;
 
+	/* proceed as DFS mount */
 	uuid_gen(&mnt_ctx.mount_id);
 	rc = connect_dfs_root(&mnt_ctx, &tl);
 	dfs_cache_free_tgts(&tl);

fs/cifs/dfs_cache.c

@@ -654,7 +654,7 @@ static struct cache_entry *__lookup_cache_entry(const char *path, unsigned int h
 			return ce;
 		}
 	}
-	return ERR_PTR(-EEXIST);
+	return ERR_PTR(-ENOENT);
 }
 
 /*
@@ -662,7 +662,7 @@ static struct cache_entry *__lookup_cache_entry(const char *path, unsigned int h
  *
  * Use whole path components in the match.  Must be called with htable_rw_lock held.
  *
- * Return ERR_PTR(-EEXIST) if the entry is not found.
+ * Return ERR_PTR(-ENOENT) if the entry is not found.
  */
 static struct cache_entry *lookup_cache_entry(const char *path)
 {
@@ -710,7 +710,7 @@ static struct cache_entry *lookup_cache_entry(const char *path)
 		while (e > s && *e != sep)
 			e--;
 	}
-	return ERR_PTR(-EEXIST);
+	return ERR_PTR(-ENOENT);
 }
 
 /**

fs/cifs/misc.c

@@ -1309,7 +1309,7 @@ int cifs_update_super_prepath(struct cifs_sb_info *cifs_sb, char *prefix)
  * for "\<server>\<dfsname>\<linkpath>" DFS reference,
  * where <dfsname> contains non-ASCII unicode symbols.
  *
- * Check such DFS reference and emulate -ENOENT if it is actual.
+ * Check such DFS reference.
  */
 int cifs_dfs_query_info_nonascii_quirk(const unsigned int xid,
 				       struct cifs_tcon *tcon,
@@ -1341,10 +1341,6 @@ int cifs_dfs_query_info_nonascii_quirk(const unsigned int xid,
 		cifs_dbg(FYI, "DFS ref '%s' is found, emulate -EREMOTE\n",
 			 dfspath);
 		rc = -EREMOTE;
-	} else if (rc == -EEXIST) {
-		cifs_dbg(FYI, "DFS ref '%s' is not found, emulate -ENOENT\n",
-			 dfspath);
-		rc = -ENOENT;
 	} else {
 		cifs_dbg(FYI, "%s: dfs_cache_find returned %d\n", __func__, rc);
 	}