From c83b20d73bc839cbb9d08eec682d4970992a78b5 Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Thu, 23 Nov 2017 12:44:49 +0100 Subject: [PATCH] mount-util: EOVERFLOW might have other causes than buffer size issues When we get EOVERFLOW this might be caused by untriggered nfs4 mounts (see discussion at https://github.com/systemd/systemd/pull/7395#issuecomment-346164481 and further down). Handle this nicely by falling back to fdinfo-based mntid determination. Fixes: #7082 --- src/basic/mount-util.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/src/basic/mount-util.c b/src/basic/mount-util.c index ac072fa..d20da34 100644 --- a/src/basic/mount-util.c +++ b/src/basic/mount-util.c @@ -183,9 +183,10 @@ int fd_is_mount_point(int fd, const char *filename, int flags) { * real mounts of their own. */ r = name_to_handle_at_loop(fd, filename, &h, &mount_id, flags); - if (IN_SET(r, -ENOSYS, -EACCES, -EPERM)) - /* This kernel does not support name_to_handle_at() at all, or the syscall was blocked (maybe through - * seccomp, because we are running inside of a container?): fall back to simpler logic. */ + if (IN_SET(r, -ENOSYS, -EACCES, -EPERM, -EOVERFLOW)) + /* This kernel does not support name_to_handle_at() at all (ENOSYS), or the syscall was blocked + * (EACCES/EPERM; maybe through seccomp, because we are running inside of a container?), or the mount + * point is not triggered yet (EOVERFLOW, thinkg nfs4): fall back to simpler logic. */ goto fallback_fdinfo; else if (r == -EOPNOTSUPP) /* This kernel or file system does not support name_to_handle_at(), hence let's see if the upper fs @@ -307,7 +308,7 @@ int path_get_mnt_id(const char *path, int *ret) { int r; r = name_to_handle_at_loop(AT_FDCWD, path, NULL, ret, 0); - if (IN_SET(r, -EOPNOTSUPP, -ENOSYS, -EACCES, -EPERM)) /* kernel/fs don't support this, or seccomp blocks access */ + if (IN_SET(r, -EOPNOTSUPP, -ENOSYS, -EACCES, -EPERM, -EOVERFLOW)) /* kernel/fs don't support this, or seccomp blocks access, or untriggered mount */ return fd_fdinfo_mnt_id(AT_FDCWD, path, 0, ret); return r; -- 2.7.4