cgroup_file_mode(9)

💅 cgroup_file_mode(9) — the "what perms does this control file get" girlie

ok so this is a page from the Kernel API Manual, and it's about cgroup_file_mode. It's short, it's sweet, it's lowkey iconic. Let's get into it 🫶

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✨ NAME ✨

cgroup_file_mode — deduce file mode of a control file

Like, you hand it a control file and it tells you what mode that file should have. That's the whole vibe check. 🎀

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🌸 SYNOPSIS 🌸

umode_t cgroup_file_mode (const struct cftype *cft );

That's it. One argument. No cap. ✨

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🦋 ARGUMENTS 🦋

• cft — the control file in question. bestie, this is literally just the control file you're asking about 💖

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💅 DESCRIPTION 💅

So here's the tea: it's S_IRUGO for read, and S_IWUSR for write.

That's the whole description. Yes really. She's concise. She knows what she is. 👑

ngl the entire function is basically "read = yes for everyone, write = only for the owner," and honestly? periodt.

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🔥 SEE ALSO 🔥

ok there are like SO many siblings, buckle up. Also peep the kernel file ./kernel/cgroup/cgroup.c — that's where the main character lives:

• cgroup_ssid_enabled(9)
• cgroup_on_dfl(9)
• cgroup_e_css_by_mask(9)
• cgroup_e_css(9)
• cgroup_get_e_css(9)
• __cgroup_task_count(9)
• cgroup_task_count(9)
• for_each_css(9)
• do_each_subsys_mask(9)
• css_set_populated(9)
• css_update_populated(9)
• css_set_update_populated(9)
• css_set_move_task(9)
• compare_css_sets(9)
• find_existing_css_set(9)
• allocate_cgrp_cset_links(9)
• link_css_set(9)
• find_css_set(9)
• cgroup_calc_subtree_ss_mask(9)
• cgroup_kn_unlock(9)
• cgroup_kn_lock_live(9)
• css_clear_dir(9)
• css_populate_dir(9)
• cgroup_attach_lock(9)
• cgroup_attach_unlock(9)
• cgroup_migrate_add_task(9)
• cgroup_taskset_first(9)
• cgroup_taskset_next(9)
• cgroup_migrate_execute(9)
• cgroup_migrate_vet_dst(9)
• cgroup_migrate_finish(9)
• cgroup_migrate_add_src(9)
• cgroup_migrate_prepare_dst(9)
• cgroup_migrate(9)
• cgroup_attach_task(9)
• cgroup_update_dfl_csses(9)
• cgroup_lock_and_drain_offline(9)
• cgroup_save_control(9)
• cgroup_propagate_control(9)
• cgroup_restore_control(9)
• cgroup_apply_control_enable(9)
• cgroup_apply_control_disable(9)
• cgroup_apply_control(9)
• cgroup_finalize_control(9)
• cgroup_enable_threaded(9)
• cgroup_tryget_css(9)
• cgroup_addrm_files(9)
• cgroup_rm_cftypes(9)
• cgroup_add_cftypes(9)
• cgroup_add_dfl_cftypes(9)
• cgroup_add_legacy_cftypes(9)
• cgroup_file_notify(9)
• cgroup_file_show(9)
• css_next_child(9)
• css_next_descendant_pre(9)
• css_rightmost_descendant(9)
• css_next_descendant_post(9)
• css_has_online_children(9)
• css_task_iter_advance_css_set(9)
• css_task_iter_start(9)
• css_task_iter_next(9)
• css_task_iter_end(9)
• css_create(9)
• kill_css_sync(9)
• kill_css_finish(9)
• cgroup_destroy_locked(9)
• cgroup_init_early(9)
• cgroup_init(9)
• cgroup_fork(9)
• cgroup_v1v2_get_from_file(9)
• cgroup_get_from_file(9)
• cgroup_css_set_fork(9)
• cgroup_css_set_put_fork(9)
• cgroup_can_fork(9)
• cgroup_cancel_fork(9)
• cgroup_post_fork(9)
• cgroup_task_exit(9)
• css_tryget_online_from_dir(9)
• css_from_id(9)
• cgroup_get_from_path(9)
• cgroup_v1v2_get_from_fd(9)
• cgroup_get_from_fd(9)
• cgroup_parse_float(9)

like. that's the whole friend group. iykyk 💀🌺

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🌈 and that's the page!! this one came at you from the source spot ./kernel/cgroup, in the October 2026 release window, and it's literally titled cgroup_file_mode(9) in case you forgot already 💜🧚 bye bestie, go read your cgroup code 🎀💖