From ea2b93a8ee8678b459a49d193333cec6e4a49e70 Mon Sep 17 00:00:00 2001 From: Patrick Ohly Date: Mon, 21 Dec 2015 14:56:00 +0100 Subject: mount-setup.c: fix handling of symlink Smack labelling in cgroup setup The code introduced in f8c1a81c51 (= systemd 227) failed for me with: Failed to copy smack label from net_cls to /sys/fs/cgroup/net_cls: No such file or directory There is no need for a symlink in this case because source and target are identical. The symlink() call is allowed to fail when the target already exists. When that happens, copying the Smack label must be skipped. But the code also failed when there is a symlink, like "cpu -> cpu,cpuacct", because mac_smack_copy() got called with src="cpu,cpuacct" which fails to find the entry because the current directory is not inside /sys/fs/cgroup. The absolute path to the existing entry must be used instead. --- src/core/mount-setup.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) (limited to 'src') diff --git a/src/core/mount-setup.c b/src/core/mount-setup.c index 2b8d590ed1..d73b319c5d 100644 --- a/src/core/mount-setup.c +++ b/src/core/mount-setup.c @@ -304,13 +304,18 @@ int mount_cgroup_controllers(char ***join_controllers) { return log_oom(); r = symlink(options, t); - if (r < 0 && errno != EEXIST) - return log_error_errno(errno, "Failed to create symlink %s: %m", t); + if (r >= 0) { #ifdef SMACK_RUN_LABEL - r = mac_smack_copy(t, options); - if (r < 0 && r != -EOPNOTSUPP) - return log_error_errno(r, "Failed to copy smack label from %s to %s: %m", options, t); + _cleanup_free_ char *src; + src = strappend("/sys/fs/cgroup/", options); + if (!src) + return log_oom(); + r = mac_smack_copy(t, src); + if (r < 0 && r != -EOPNOTSUPP) + return log_error_errno(r, "Failed to copy smack label from %s to %s: %m", src, t); #endif + } else if (errno != EEXIST) + return log_error_errno(errno, "Failed to create symlink %s: %m", t); } } } -- cgit v1.2.3-54-g00ecf