The patch titled
Control Groups: Fix refcount bug
has been removed from the -mm tree. Its filename was
task-containersv11-basic-task-container-framework-containers-fix-refcount-bug.patch
This patch was dropped because it was folded into task-containersv11-basic-task-container-framework.patch
------------------------------------------------------
Subject: Control Groups: Fix refcount bug
From: Paul Menage <menage@xxxxxxxxxx>
Fix a reference counting bug in cgroupfs
As part of the extraction of cpusetfs to cgroupfs, a call to
cpuset_get_dentry() was lost (justified by the fact that the dentry in
question was now being passed down by the caller). Since
cpuset_get_dentry() called lookup_one_len(), this resulted in a reference
count being missed from the directory dentry.
This patch removes cgroup_get_dentry() and replaces it with direct calls
to lookup_one_len(); the initialization of cgroupfs dentry ops is done
now in cgroup_create_file() at dentry creation time.
Signed-off-by: Paul Menage <menage@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/cgroup.c | 24 +++++++-----------------
1 file changed, 7 insertions(+), 17 deletions(-)
diff -puN kernel/cgroup.c~task-cgroupsv11-basic-task-cgroup-framework-cgroups-fix-refcount-bug kernel/cgroup.c
--- a/kernel/cgroup.c~task-cgroupsv11-basic-task-cgroup-framework-cgroups-fix-refcount-bug
+++ a/kernel/cgroup.c
@@ -250,19 +250,6 @@ static void cgroup_diput(struct dentr
iput(inode);
}
-static struct dentry *cgroup_get_dentry(struct dentry *parent,
- const char *name)
-{
- struct dentry *d = lookup_one_len(name, parent, strlen(name));
- static struct dentry_operations cgroup_dops = {
- .d_iput = cgroup_diput,
- };
-
- if (!IS_ERR(d))
- d->d_op = &cgroup_dops;
- return d;
-}
-
static void remove_dir(struct dentry *d)
{
struct dentry *parent = dget(d->d_parent);
@@ -824,6 +811,10 @@ static struct inode_operations cgroup
static int cgroup_create_file(struct dentry *dentry, int mode,
struct super_block *sb)
{
+ static struct dentry_operations cgroup_dops = {
+ .d_iput = cgroup_diput,
+ };
+
struct inode *inode;
if (!dentry)
@@ -849,7 +840,7 @@ static int cgroup_create_file(struct
inode->i_size = 0;
inode->i_fop = &cgroup_file_operations;
}
-
+ dentry->d_op = &cgroup_dops;
d_instantiate(dentry, inode);
dget(dentry); /* Extra count - pin the dentry in core */
return 0;
@@ -870,13 +861,12 @@ static int cgroup_create_dir(struct c
int error = 0;
parent = cont->parent->dentry;
- if (IS_ERR(dentry))
- return PTR_ERR(dentry);
error = cgroup_create_file(dentry, S_IFDIR | mode, cont->root->sb);
if (!error) {
dentry->d_fsdata = cont;
inc_nlink(parent->d_inode);
cont->dentry = dentry;
+ dget(dentry);
}
dput(dentry);
@@ -898,7 +888,7 @@ int cgroup_add_file(struct cgroup
}
strcat(name, cft->name);
BUG_ON(!mutex_is_locked(&dir->d_inode->i_mutex));
- dentry = cgroup_get_dentry(dir, name);
+ dentry = lookup_one_len(name, dir, strlen(name));
if (!IS_ERR(dentry)) {
error = cgroup_create_file(dentry, 0644 | S_IFREG,
cont->root->sb);
_
Patches currently in -mm which might be from menage@xxxxxxxxxx are
cpuset-zero-malloc-revert-the-old-cpuset-fix.patch
task-containersv11-basic-task-container-framework.patch
task-containersv11-basic-task-container-framework-containers-fix-refcount-bug.patch
task-containersv11-basic-task-container-framework-fix-cgroup_create_dir-comments.patch
task-containersv11-add-tasks-file-interface.patch
add-cgroup-write_uint-helper-method.patch
task-containersv11-add-fork-exit-hooks.patch
task-containersv11-add-container_clone-interface.patch
task-containersv11-add-container_clone-interface-containers-fix-refcount-bug.patch
task-containersv11-add-procfs-interface.patch
task-containersv11-shared-container-subsystem-group-arrays.patch
task-containersv11-shared-container-subsystem-group-arrays-simplify-proc-cgroups.patch
task-containersv11-shared-container-subsystem-group-arrays-simplify-proc-cgroups-fix.patch
task-containersv11-shared-container-subsystem-group-arrays-avoid-lockdep-warning.patch
task-containersv11-shared-container-subsystem-group-arrays-include-fix.patch
task-containersv11-automatic-userspace-notification-of-idle-containers.patch
task-containersv11-automatic-userspace-notification-of-idle-containers-fix.patch
task-containersv11-make-cpusets-a-client-of-containers.patch
task-containersv11-example-cpu-accounting-subsystem.patch
task-containersv11-simple-task-container-debug-info-subsystem.patch
task-containers-enable-containers-by-default-in-some-configs.patch
add-containerstats-v3.patch
add-containerstats-v3-fix.patch
containers-implement-namespace-tracking-subsystem.patch
containers-implement-namespace-tracking-subsystem-fix-order-of-container-subsystems-in-init-kconfig.patch
pid-namespaces-rework-forget_original_parent.patch
pid-namespaces-move-exit_task_namespaces.patch
pid-namespaces-introduce-ms_kernmount-flag.patch
pid-namespaces-prepare-proc_flust_task-to-flush-entries-from-multiple-proc-trees.patch
pid-namespaces-introduce-struct-upid.patch
pid-namespaces-add-support-for-pid-namespaces-hierarchy.patch
pid-namespaces-make-alloc_pid-free_pid-and-put_pid-work-with-struct-upid.patch
pid-namespaces-helpers-to-obtain-pid-numbers.patch
pid-namespaces-helpers-to-find-the-task-by-its-numerical-ids.patch
pid-namespaces-helpers-to-find-the-task-by-its-numerical-ids-fix.patch
pid-namespaces-move-alloc_pid-lower-in-copy_process.patch
pid-namespaces-make-proc-have-multiple-superblocks-one-for-each-namespace.patch
pid-namespaces-miscelaneous-preparations-for-pid-namespaces.patch
pid-namespaces-allow-cloning-of-new-namespace.patch
pid-namespaces-make-proc_flush_task-actually-from-entries-from-multiple-namespaces.patch
pid-namespaces-initialize-the-namespaces-proc_mnt.patch
pid-namespaces-create-a-slab-cache-for-struct-pid_namespace.patch
pid-namespaces-allow-signalling-container-init.patch
pid-namespaces-destroy-pid-namespace-on-inits-death.patch
pid-namespaces-changes-to-show-virtual-ids-to-user.patch
uninline-find_task_by_xxx-set-of-functions.patch
pid-namespaces-changes-to-show-virtual-ids-to-user-fix.patch
pid-namespaces-remove-the-struct-pid-unneeded-fields.patch
uninline-find_pid-etc-set-of-functions.patch
uninline-the-task_xid_nr_ns-calls.patch
cpusets-decrustify-cpuset-mask-update-code.patch
fix-cpusets-update_cpumask.patch
fix-cpusets-update_cpumask-checkpatch-fixes.patch
use-task_pid_nr-instead-of-pid_nrtask_pid.patch
control-groups-replace-cont-with-cgrp-and-other-misc.patch
hook-up-group-scheduler-with-control-groups.patch
hook-up-group-scheduler-with-control-groups-fix.patch
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