diff options
Diffstat (limited to 'block')
-rw-r--r-- | block/Makefile | 1 | ||||
-rw-r--r-- | block/blk-cgroup-fc-appid.c | 57 |
2 files changed, 58 insertions, 0 deletions
diff --git a/block/Makefile b/block/Makefile index 3950ecbc5c26..4e01bb71ad6e 100644 --- a/block/Makefile +++ b/block/Makefile @@ -16,6 +16,7 @@ obj-$(CONFIG_BLK_DEV_BSG_COMMON) += bsg.o obj-$(CONFIG_BLK_DEV_BSGLIB) += bsg-lib.o obj-$(CONFIG_BLK_CGROUP) += blk-cgroup.o obj-$(CONFIG_BLK_CGROUP_RWSTAT) += blk-cgroup-rwstat.o +obj-$(CONFIG_BLK_CGROUP_FC_APPID) += blk-cgroup-fc-appid.o obj-$(CONFIG_BLK_DEV_THROTTLING) += blk-throttle.o obj-$(CONFIG_BLK_CGROUP_IOPRIO) += blk-ioprio.o obj-$(CONFIG_BLK_CGROUP_IOLATENCY) += blk-iolatency.o diff --git a/block/blk-cgroup-fc-appid.c b/block/blk-cgroup-fc-appid.c new file mode 100644 index 000000000000..760a2e1878dd --- /dev/null +++ b/block/blk-cgroup-fc-appid.c @@ -0,0 +1,57 @@ +// 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 (!cgrp) + return -ENOENT; + 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. + */ + strlcpy(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); |