From 80340fe3605c0e78cfe496c3b3878be828cfdbfe Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Thu, 14 May 2020 16:44:24 +0200 Subject: statx: add mount_root Determining whether a path or file descriptor refers to a mountpoint (or more precisely a mount root) is not trivial using current tools. Add a flag to statx that indicates whether the path or fd refers to the root of a mount or not. Cc: linux-api@vger.kernel.org Cc: linux-man@vger.kernel.org Reported-by: Lennart Poettering Reported-by: J. Bruce Fields Signed-off-by: Miklos Szeredi Reviewed-by: Christoph Hellwig --- fs/stat.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'fs/stat.c') diff --git a/fs/stat.c b/fs/stat.c index 3d88c99f7743..b9faa6cafafe 100644 --- a/fs/stat.c +++ b/fs/stat.c @@ -202,6 +202,9 @@ retry: error = vfs_getattr(&path, stat, request_mask, flags); stat->mnt_id = real_mount(path.mnt)->mnt_id; stat->result_mask |= STATX_MNT_ID; + if (path.mnt->mnt_root == path.dentry) + stat->attributes |= STATX_ATTR_MOUNT_ROOT; + stat->attributes_mask |= STATX_ATTR_MOUNT_ROOT; path_put(&path); if (retry_estale(error, lookup_flags)) { lookup_flags |= LOOKUP_REVAL; -- cgit