58 lines
1.4 KiB
C
58 lines
1.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
|
|
#include "blk-cgroup.h"
|
|
|
|
/**
|
|
* blkcg_set_fc_appid - set the fc_app_id field associted to blkcg
|
|
* @app_id: application identifier
|
|
* @cgrp_id: cgroup id
|
|
* @app_id_len: size of application identifier
|
|
*/
|
|
int blkcg_set_fc_appid(char *app_id, u64 cgrp_id, size_t app_id_len)
|
|
{
|
|
struct cgroup *cgrp;
|
|
struct cgroup_subsys_state *css;
|
|
struct blkcg *blkcg;
|
|
int ret = 0;
|
|
|
|
if (app_id_len > FC_APPID_LEN)
|
|
return -EINVAL;
|
|
|
|
cgrp = cgroup_get_from_id(cgrp_id);
|
|
if (IS_ERR(cgrp))
|
|
return PTR_ERR(cgrp);
|
|
css = cgroup_get_e_css(cgrp, &io_cgrp_subsys);
|
|
if (!css) {
|
|
ret = -ENOENT;
|
|
goto out_cgrp_put;
|
|
}
|
|
blkcg = css_to_blkcg(css);
|
|
/*
|
|
* There is a slight race condition on setting the appid.
|
|
* Worst case an I/O may not find the right id.
|
|
* This is no different from the I/O we let pass while obtaining
|
|
* the vmid from the fabric.
|
|
* Adding the overhead of a lock is not necessary.
|
|
*/
|
|
strscpy(blkcg->fc_app_id, app_id, app_id_len);
|
|
css_put(css);
|
|
out_cgrp_put:
|
|
cgroup_put(cgrp);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(blkcg_set_fc_appid);
|
|
|
|
/**
|
|
* blkcg_get_fc_appid - get the fc app identifier associated with a bio
|
|
* @bio: target bio
|
|
*
|
|
* On success return the fc_app_id, on failure return NULL
|
|
*/
|
|
char *blkcg_get_fc_appid(struct bio *bio)
|
|
{
|
|
if (!bio->bi_blkg || bio->bi_blkg->blkcg->fc_app_id[0] == '\0')
|
|
return NULL;
|
|
return bio->bi_blkg->blkcg->fc_app_id;
|
|
}
|
|
EXPORT_SYMBOL_GPL(blkcg_get_fc_appid);
|