Messages in this thread Patch in this message | | | Date | Thu, 15 Mar 2012 09:56:55 -0700 | From | Tejun Heo <> | Subject | [PATCH] cgroup: deprecate remount option changes mount option |
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This patch marks the following features for deprecation.
* Rebinding subsys by remount: Never reached useful state - only works on empty hierarchies.
* release_agent update by remount: release_agent itself will be replaced with conventional fsnotify notification.
v2: Lennart pointed out that "name=" is necessary for mounts w/o any controller attached. Drop "name=" deprecation.
Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Lennart Poettering <mzxreary@0pointer.de> --- Documentation/feature-removal-schedule.txt | 10 ++++++++++ kernel/cgroup.c | 5 +++++ 2 files changed, 15 insertions(+)
Index: work/Documentation/feature-removal-schedule.txt =================================================================== --- work.orig/Documentation/feature-removal-schedule.txt +++ work/Documentation/feature-removal-schedule.txt @@ -510,3 +510,13 @@ Why: The pci_scan_bus_parented() interfa convert to using pci_scan_root_bus() so they can supply a list of bus resources when the bus is created. Who: Bjorn Helgaas <bhelgaas@google.com> + +---------------------------- + +What: cgroup option updates via remount +When: March 2013 +Why: Remount currently allows changing bound subsystems and + release_agent. Rebinding is hardly useful as it only works + when the hierarchy is empty and release_agent itself should be + replaced with conventional fsnotify. +Who: Tejun Heo <tj@kernel.org> Index: work/kernel/cgroup.c =================================================================== --- work.orig/kernel/cgroup.c +++ work/kernel/cgroup.c @@ -1294,6 +1294,11 @@ static int cgroup_remount(struct super_b if (ret) goto out_unlock; + /* See feature-removal-schedule.txt */ + if (opts.subsys_bits != root->actual_subsys_bits || opts.release_agent) + pr_warning("cgroup: option changes via remount are deprecated (pid=%d comm=%s)\n", + task_tgid_nr(current), current->comm); + /* Don't allow flags or name to change at remount */ if (opts.flags != root->flags || (opts.name && strcmp(opts.name, root->name))) {
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