From 6feeeab0bc40b5a7f208adf79909fb85e2208e8e Mon Sep 17 00:00:00 2001 From: =?utf8?q?Zbigniew=20J=C4=99drzejewski-Szmek?= Date: Wed, 17 Dec 2014 21:05:58 -0500 Subject: [PATCH] path: make the check for unsupported name_to_handle_at symmetric If child supports, but the parent does not, or when the child does not support, but the parent does, assume the child is a mount point. Only if neither supports use the fallback. --- src/shared/path-util.c | 35 ++++++++++++++++++++--------------- 1 file changed, 20 insertions(+), 15 deletions(-) diff --git a/src/shared/path-util.c b/src/shared/path-util.c index fae5d20eb..8c43d060f 100644 --- a/src/shared/path-util.c +++ b/src/shared/path-util.c @@ -462,6 +462,7 @@ int path_is_mount_point(const char *t, bool allow_symlink) { _cleanup_free_ char *parent = NULL; struct stat a, b; int r; + bool nosupp = false; /* We are not actually interested in the file handles, but * name_to_handle_at() also passes us the mount ID, hence use @@ -476,12 +477,11 @@ int path_is_mount_point(const char *t, bool allow_symlink) { /* This kernel or file system does not support * name_to_handle_at(), hence fallback to the * traditional stat() logic */ - goto fallback; - - if (errno == ENOENT) + nosupp = true; + else if (errno == ENOENT) return 0; - - return -errno; + else + return -errno; } r = path_get_parent(t, &parent); @@ -490,17 +490,22 @@ int path_is_mount_point(const char *t, bool allow_symlink) { h.handle.handle_bytes = MAX_HANDLE_SZ; r = name_to_handle_at(AT_FDCWD, parent, &h.handle, &mount_id_parent, AT_SYMLINK_FOLLOW); - if (r < 0) { - /* The parent can't do name_to_handle_at() but the - * directory we are interested in can? If so, it must - * be a mount point */ + if (r < 0) if (errno == EOPNOTSUPP) - return 1; - - return -errno; - } - - return mount_id != mount_id_parent; + if (nosupp) + /* Neither parent nor child do name_to_handle_at()? + We have no choice but to fall back. */ + goto fallback; + else + /* The parent can't do name_to_handle_at() but + * the directory we are interested in can? + * Or the other way around? + * If so, it must be a mount point. */ + return 1; + else + return -errno; + else + return mount_id != mount_id_parent; fallback: if (allow_symlink) -- 2.30.2