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| author | Muneendra Kumar <muneendra.kumar@broadcom.com> | 2021-06-08 06:35:44 +0200 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2021-06-10 16:01:31 +0200 |
| commit | 6b658c4863c15936872a93c9ee879043bf6393c9 (patch) | |
| tree | b53389d6f04f38d41813f520995cff3180815d53 /kernel/cgroup | |
| parent | scsi: fc: FDMI enhancement (diff) | |
| download | linux-6b658c4863c15936872a93c9ee879043bf6393c9.tar.xz linux-6b658c4863c15936872a93c9ee879043bf6393c9.zip | |
scsi: cgroup: Add cgroup_get_from_id()
Add a new function, cgroup_get_from_id(), to retrieve the cgroup associated
with a cgroup id. Also export the function cgroup_get_e_css() as this is
needed in blk-cgroup.h.
Link: https://lore.kernel.org/r/20210608043556.274139-2-muneendra.kumar@broadcom.com
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Muneendra Kumar <muneendra.kumar@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'kernel/cgroup')
| -rw-r--r-- | kernel/cgroup/cgroup.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index e049edd66776..692779d3cdfa 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -577,6 +577,7 @@ out_unlock: rcu_read_unlock(); return css; } +EXPORT_SYMBOL_GPL(cgroup_get_e_css); static void cgroup_get_live(struct cgroup *cgrp) { @@ -5777,6 +5778,31 @@ void cgroup_path_from_kernfs_id(u64 id, char *buf, size_t buflen) } /* + * cgroup_get_from_id : get the cgroup associated with cgroup id + * @id: cgroup id + * On success return the cgrp, on failure return NULL + */ +struct cgroup *cgroup_get_from_id(u64 id) +{ + struct kernfs_node *kn; + struct cgroup *cgrp = NULL; + + mutex_lock(&cgroup_mutex); + kn = kernfs_find_and_get_node_by_id(cgrp_dfl_root.kf_root, id); + if (!kn) + goto out_unlock; + + cgrp = kn->priv; + if (cgroup_is_dead(cgrp) || !cgroup_tryget(cgrp)) + cgrp = NULL; + kernfs_put(kn); +out_unlock: + mutex_unlock(&cgroup_mutex); + return cgrp; +} +EXPORT_SYMBOL_GPL(cgroup_get_from_id); + +/* * proc_cgroup_show() * - Print task's cgroup paths into seq_file, one line for each hierarchy * - Used for /proc/<pid>/cgroup. |