Merge branch 'for-5.17-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj...

[linux-2.6-microblaze.git] / kernel / cgroup / cgroup.c

diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 77702e0..a557eea 100644 (file)
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -3643,6 +3643,12 @@ static ssize_t cgroup_pressure_write(struct kernfs_open_file *of, char *buf,
        cgroup_get(cgrp);
        cgroup_kn_unlock(of->kn);
 
+       /* Allow only one trigger per file descriptor */
+       if (ctx->psi.trigger) {
+               cgroup_put(cgrp);
+               return -EBUSY;
+       }
+
        psi = cgroup_ino(cgrp) == 1 ? &psi_system : &cgrp->psi;
        new = psi_trigger_create(psi, buf, nbytes, res);
        if (IS_ERR(new)) {
@@ -3650,8 +3656,7 @@ static ssize_t cgroup_pressure_write(struct kernfs_open_file *of, char *buf,
                return PTR_ERR(new);
        }
 
-       psi_trigger_replace(&ctx->psi.trigger, new);
-
+       smp_store_release(&ctx->psi.trigger, new);
        cgroup_put(cgrp);
 
        return nbytes;
@@ -3690,7 +3695,7 @@ static void cgroup_pressure_release(struct kernfs_open_file *of)
 {
        struct cgroup_file_ctx *ctx = of->priv;
 
-       psi_trigger_replace(&ctx->psi.trigger, NULL);
+       psi_trigger_destroy(ctx->psi.trigger);
 }
 
 bool cgroup_psi_enabled(void)