blkcg_css_offline(9)

💖 NAME 💖

okay so bestie, this is blkcg_css_offline(9) from the Kernel API Manual — the cgroup css_offline callback, and she’s lowkey iconic 🫶✨

blkcg_css_offline — cgroup css_offline callback. That’s the whole vibe: it’s the callback for the offline moment of a cgroup css 💅

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🦋 SYNOPSIS 🦋

she takes exactly one argument, and here’s the signature in all its exact glory:

void blkcg_css_offline (struct cgroup_subsys_state *css );

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🌸 ARGUMENTS 🌸

• css — the css of interest, aka the one we’re checking on here 💖

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✨ DESCRIPTION ✨

okay so this function gets called when css is about to go away 😭. first up, the cgwbs get offlined, and it’s literally only once the writeback associated with the blkcg has finished that we start step 2 (see above) ✨. no skipping ahead, bestie.

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🎀 SEE ALSO 🎀

kernel file: ./block/blk-cgroup.c — and the whole friend group is right here, no cap:

• blkcg_css(9)
• blkg_free(9)
• bio_blkcg_css(9)
• blkcg_parent(9)
• blkg_alloc(9)
• blkg_lookup_create(9)
• blkcg_print_blkgs(9)
• __blkg_prfill_u64(9)
• blkg_conf_init(9)
• blkg_conf_open_bdev(9)
• blkg_conf_prep(9)
• blkg_conf_unprep(9)
• blkg_conf_close_bdev(9)
• blkcg_destroy_blkgs(9)
• blkcg_pin_online(9)
• blkcg_unpin_online(9)
• blkcg_activate_policy(9)
• blkcg_deactivate_policy(9)
• blkcg_policy_register(9)
• blkcg_policy_unregister(9)
• blkcg_maybe_throttle_current(9)
• blkcg_schedule_throttle(9)
• blkcg_add_delay(9)
• blkg_tryget_closest(9)
• bio_associate_blkg_from_css(9)
• bio_associate_blkg(9)
• bio_clone_blkg_association(9)

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mwah 💋 — source/version: ./block, date: October 2026, page: blkcg_css_offline(9). bye bestie, go read the kernel 🧚‍♀️💜