From 1640a0b6b05b8ae01abbe5939f86f17a61e7998f Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Tue, 4 Sep 2012 16:37:57 -0700 Subject: [PATCH] path-util: in path_is_mount_point() fall back to the classic stat() test if fs does not support name_to_handle_at() --- src/shared/path-util.c | 36 +++++++++++++++++++++++++++++++++++- 1 file changed, 35 insertions(+), 1 deletion(-) diff --git a/src/shared/path-util.c b/src/shared/path-util.c index 4cb0b03c5..2dddc8f2f 100644 --- a/src/shared/path-util.c +++ b/src/shared/path-util.c @@ -335,6 +335,7 @@ int path_is_mount_point(const char *t, bool allow_symlink) { int r; struct file_handle *h; int mount_id, mount_id_parent; + struct stat a, b; /* We are not actually interested in the file handles, but * name_to_handle_at() also passes us the mount ID, hence use @@ -348,6 +349,12 @@ int path_is_mount_point(const char *t, bool allow_symlink) { r = name_to_handle_at(AT_FDCWD, t, h, &mount_id, allow_symlink ? AT_SYMLINK_FOLLOW : 0); if (r < 0) { + if (errno == ENOTSUP) + /* This file system does not support + * name_to_handle_at(), hence fallback to the + * traditional stat() logic */ + goto fallback; + if (errno == ENOENT) return 0; @@ -362,11 +369,38 @@ int path_is_mount_point(const char *t, bool allow_symlink) { r = name_to_handle_at(AT_FDCWD, parent, h, &mount_id_parent, 0); free(parent); + 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 (errno == ENOTSUP) + return 1; + + return -errno; + } + + return mount_id != mount_id_parent; + +fallback: + if (allow_symlink) + r = stat(t, &a); + else + r = lstat(t, &b); + if (r < 0) return -errno; + r = path_get_parent(t, &parent); + if (r < 0) + return r; - return mount_id != mount_id_parent; + r = lstat(parent, &b); + free(parent); + + if (r < 0) + return -errno; + + return a.st_dev != b.st_dev; } int path_is_read_only_fs(const char *path) { -- 2.30.2