From: Christian Brauner <christian.brauner@ubuntu.com> To: linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com>, Christian Brauner <christian.brauner@ubuntu.com>, Johannes Weiner <hannes@cmpxchg.org>, Li Zefan <lizefan@huawei.com>, cgroups@vger.kernel.org Subject: [PATCH v4 4/6] cgroup: add cgroup_may_write() helper Date: Fri, 17 Jan 2020 19:12:17 +0100 [thread overview] Message-ID: <20200117181219.14542-5-christian.brauner@ubuntu.com> (raw) In-Reply-To: <20200117181219.14542-1-christian.brauner@ubuntu.com> Add a cgroup_may_write() helper which we can use in the CLONE_INTO_CGROUP patch series to verify that we can write to the destination cgroup. Cc: Tejun Heo <tj@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Li Zefan <lizefan@huawei.com> Cc: cgroups@vger.kernel.org Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> --- /* v1 */ patch not present /* v2 */ patch not present /* v3 */ patch not present /* v4 */ patch introduced --- kernel/cgroup/cgroup.c | 24 +++++++++++++++++------- 1 file changed, 17 insertions(+), 7 deletions(-) diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 49d8cf087e10..b110b435ae49 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -4649,13 +4649,28 @@ static int cgroup_procs_show(struct seq_file *s, void *v) return 0; } +static int cgroup_may_write(const struct cgroup *cgrp, struct super_block *sb) +{ + int ret; + struct inode *inode; + + lockdep_assert_held(&cgroup_mutex); + + inode = kernfs_get_inode(sb, cgrp->procs_file.kn); + if (!inode) + return -ENOMEM; + + ret = inode_permission(inode, MAY_WRITE); + iput(inode); + return ret; +} + static int cgroup_procs_write_permission(struct cgroup *src_cgrp, struct cgroup *dst_cgrp, struct super_block *sb) { struct cgroup_namespace *ns = current->nsproxy->cgroup_ns; struct cgroup *com_cgrp = src_cgrp; - struct inode *inode; int ret; lockdep_assert_held(&cgroup_mutex); @@ -4665,12 +4680,7 @@ static int cgroup_procs_write_permission(struct cgroup *src_cgrp, com_cgrp = cgroup_parent(com_cgrp); /* %current should be authorized to migrate to the common ancestor */ - inode = kernfs_get_inode(sb, com_cgrp->procs_file.kn); - if (!inode) - return -ENOMEM; - - ret = inode_permission(inode, MAY_WRITE); - iput(inode); + ret = cgroup_may_write(com_cgrp, sb); if (ret) return ret; -- 2.25.0
WARNING: multiple messages have this Message-ID (diff)
From: Christian Brauner <christian.brauner-GeWIH/nMZzLQT0dZR+AlfA@public.gmane.org> To: linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> Cc: Oleg Nesterov <oleg-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>, Christian Brauner <christian.brauner-GeWIH/nMZzLQT0dZR+AlfA@public.gmane.org>, Johannes Weiner <hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org>, Li Zefan <lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Subject: [PATCH v4 4/6] cgroup: add cgroup_may_write() helper Date: Fri, 17 Jan 2020 19:12:17 +0100 [thread overview] Message-ID: <20200117181219.14542-5-christian.brauner@ubuntu.com> (raw) In-Reply-To: <20200117181219.14542-1-christian.brauner-GeWIH/nMZzLQT0dZR+AlfA@public.gmane.org> Add a cgroup_may_write() helper which we can use in the CLONE_INTO_CGROUP patch series to verify that we can write to the destination cgroup. Cc: Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> Cc: Johannes Weiner <hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org> Cc: Li Zefan <lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org> Cc: cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Signed-off-by: Christian Brauner <christian.brauner-GeWIH/nMZzLQT0dZR+AlfA@public.gmane.org> --- /* v1 */ patch not present /* v2 */ patch not present /* v3 */ patch not present /* v4 */ patch introduced --- kernel/cgroup/cgroup.c | 24 +++++++++++++++++------- 1 file changed, 17 insertions(+), 7 deletions(-) diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 49d8cf087e10..b110b435ae49 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -4649,13 +4649,28 @@ static int cgroup_procs_show(struct seq_file *s, void *v) return 0; } +static int cgroup_may_write(const struct cgroup *cgrp, struct super_block *sb) +{ + int ret; + struct inode *inode; + + lockdep_assert_held(&cgroup_mutex); + + inode = kernfs_get_inode(sb, cgrp->procs_file.kn); + if (!inode) + return -ENOMEM; + + ret = inode_permission(inode, MAY_WRITE); + iput(inode); + return ret; +} + static int cgroup_procs_write_permission(struct cgroup *src_cgrp, struct cgroup *dst_cgrp, struct super_block *sb) { struct cgroup_namespace *ns = current->nsproxy->cgroup_ns; struct cgroup *com_cgrp = src_cgrp; - struct inode *inode; int ret; lockdep_assert_held(&cgroup_mutex); @@ -4665,12 +4680,7 @@ static int cgroup_procs_write_permission(struct cgroup *src_cgrp, com_cgrp = cgroup_parent(com_cgrp); /* %current should be authorized to migrate to the common ancestor */ - inode = kernfs_get_inode(sb, com_cgrp->procs_file.kn); - if (!inode) - return -ENOMEM; - - ret = inode_permission(inode, MAY_WRITE); - iput(inode); + ret = cgroup_may_write(com_cgrp, sb); if (ret) return ret; -- 2.25.0
next prev parent reply other threads:[~2020-01-17 18:12 UTC|newest] Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-01-17 18:12 [PATCH v4 0/6] clone3 & cgroups: allow spawning processes into cgroups Christian Brauner 2020-01-17 18:12 ` Christian Brauner 2020-01-17 18:12 ` [PATCH v4 1/6] cgroup: unify attach permission checking Christian Brauner 2020-01-17 18:12 ` Christian Brauner 2020-01-20 14:42 ` Oleg Nesterov 2020-01-20 14:42 ` Oleg Nesterov 2020-01-20 14:46 ` Christian Brauner 2020-01-20 14:46 ` Christian Brauner 2020-01-17 18:12 ` [PATCH v4 2/6] cgroup: add cgroup_get_from_file() helper Christian Brauner 2020-01-17 18:12 ` Christian Brauner 2020-01-17 18:12 ` [PATCH v4 3/6] cgroup: refactor fork helpers Christian Brauner 2020-01-17 18:12 ` Christian Brauner 2020-01-20 14:00 ` Oleg Nesterov 2020-01-20 14:04 ` Christian Brauner 2020-01-20 14:22 ` Oleg Nesterov 2020-01-20 14:33 ` Christian Brauner 2020-01-20 14:33 ` Christian Brauner 2020-01-17 18:12 ` Christian Brauner [this message] 2020-01-17 18:12 ` [PATCH v4 4/6] cgroup: add cgroup_may_write() helper Christian Brauner 2020-01-17 18:12 ` [PATCH v4 5/6] clone3: allow spawning processes into cgroups Christian Brauner 2020-01-17 18:12 ` Christian Brauner 2020-01-17 18:12 ` Christian Brauner 2020-01-20 15:39 ` Oleg Nesterov 2020-01-20 15:39 ` Oleg Nesterov 2020-01-20 21:38 ` Christian Brauner 2020-01-17 18:12 ` [PATCH v4 6/6] selftests/cgroup: add tests for cloning " Christian Brauner 2020-01-17 20:24 ` Roman Gushchin
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