sysfs_mbox_write(9)

🎀 sysfs_mbox_write — a Kernel API Manual moment (section 9, bestie) 🎀

Okay so you found sysfs_mbox_write(9) in the Kernel API Manual and you're like "what is this?" — and honestly? Same. Let's get into it. 💅

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✨ NAME ✨

sysfs_mbox_write — the Write method for writing information via mbox. That's the whole vibe. It writes stuff. Through mbox. We move.

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🌸 SYNOPSIS 🌸

ssize_t sysfs_mbox_write (struct file *filp , struct kobject *kobj ,
const struct bin_attribute *bin_attr , char *buf , loff_t off , size_t
count );

Look at that signature. Six whole arguments. She's committed. 🔥

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🦋 ARGUMENTS 🦋

Every single one, no skipping, we're not doing that:

• filp — the open sysfs file, bestie. It's the file handle doing the opening.
• kobj — the kernel kobject that contains the kernel class device. She's got the whole class-device situation going on.
• bin_attr — the kernel attributes that got passed to us. Handed over. Given. Ours now.
• buf — contains the data to be written to sysfs mbox. This is the payload, the actual content, the material. 🫶
• off — offset into buffer to beginning of data. So like, where the data actually starts, not just "somewhere in there".
• count — bytes to transfer. Count them. Then transfer them.

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💖 DESCRIPTION 💖

🚨 Deprecated function. 🚨

No cap, she's deprecated. This is a legacy icon, and we respect her history while acknowledging she's not the moment anymore. 😭

All mailbox access from user space is performed via the bsg interface. That's the whole assignment. That's where the mailbox business lives now. Not here. Ivy League, don't be mad.

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⭐ RETURN ⭐

• -EPERM — operation not permitted. Yeah. That's the return value. That's it. That's the whole list. She said no. 🚫

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🌈 SEE ALSO 🌈

Okay bestie, sit down, hydrate, because this list is giving extended universe. The kernel file to look at is ./drivers/scsi/lpfc/lpfc_attr.c, and here's everybody invited to the group chat 💜:

• lpfc_jedec_to_ascii(9), lpfc_drvr_version_show(9), lpfc_enable_fip_show(9), lpfc_info_show(9), lpfc_serialnum_show(9), lpfc_temp_sensor_show(9), lpfc_modeldesc_show(9), lpfc_modelname_show(9), lpfc_programtype_show(9), lpfc_vportnum_show(9), lpfc_fwrev_show(9), lpfc_hdw_show(9)
• lpfc_option_rom_version_show(9), lpfc_link_state_show(9), lpfc_sli4_protocol_show(9), lpfc_oas_supported_show(9), lpfc_link_state_store(9), lpfc_num_discovered_ports_show(9), lpfc_issue_lip(9), lpfc_do_offline(9), lpfc_reset_pci_bus(9), lpfc_selective_reset(9), lpfc_issue_reset(9), lpfc_sli4_pdev_status_reg_wait(9)
• lpfc_sli4_pdev_reg_request(9), lpfc_nport_evt_cnt_show(9), lpfc_board_mode_show(9), lpfc_board_mode_store(9), lpfc_get_hba_info(9), lpfc_max_rpi_show(9), lpfc_used_rpi_show(9), lpfc_max_xri_show(9), lpfc_used_xri_show(9), lpfc_max_vpi_show(9), lpfc_used_vpi_show(9), lpfc_npiv_info_show(9)
• lpfc_poll_show(9), lpfc_poll_store(9), lpfc_sriov_hw_max_virtfn_show(9), lpfc_enable_bbcr_set(9), lpfc_wwn_set(9), lpfc_oas_tgt_show(9), lpfc_oas_tgt_store(9), lpfc_oas_priority_show(9), lpfc_oas_priority_store(9), lpfc_oas_vpt_show(9), lpfc_oas_vpt_store(9), lpfc_oas_lun_state_show(9)
• lpfc_oas_lun_state_store(9), lpfc_oas_lun_status_show(9), lpfc_oas_lun_state_set(9), lpfc_oas_lun_get_next(9), lpfc_oas_lun_state_change(9), lpfc_oas_lun_show(9), lpfc_oas_lun_store(9), lpfc_nodev_tmo_show(9), lpfc_nodev_tmo_init(9), lpfc_update_rport_devloss_tmo(9), lpfc_nodev_tmo_set(9), lpfc_devloss_tmo_set(9)
• lpfc_tgt_queue_depth_set(9), lpfc_restrict_login_init(9), lpfc_restrict_login_set(9), lpfc_topology_store(9), lpfc_static_vport_show(9), lpfc_link_speed_store(9), lpfc_link_speed_init(9), lpfc_aer_support_store(9), lpfc_aer_cleanup_state(9), lpfc_sriov_nr_virtfn_store(9), lpfc_request_firmware_upgrade_store(9), lpfc_request_firmware_upgrade_init(9)
• lpfc_force_rscn_store(9), lpfc_force_rscn_init(9), lpfc_fcp_imax_store(9), lpfc_fcp_imax_init(9), lpfc_cq_max_proc_limit_store(9), lpfc_cq_max_proc_limit_init(9), lpfc_fcp_cpu_map_show(9), lpfc_fcp_cpu_map_store(9), lpfc_fcp_cpu_map_init(9), lpfc_cpumask_irq_mode_init(9), lpfc_irq_chann_show(9), lpfc_sg_seg_cnt_show(9)
• lpfc_sg_seg_cnt_init(9), sysfs_ctlreg_write(9), sysfs_ctlreg_read(9), sysfs_mbox_read(9), lpfc_alloc_sysfs_attr(9), lpfc_free_sysfs_attr(9), lpfc_get_host_symbolic_name(9), lpfc_get_host_port_id(9), lpfc_get_host_port_type(9), lpfc_get_host_port_state(9), lpfc_get_host_speed(9), lpfc_get_host_fabric_name(9)
• lpfc_get_stats(9), lpfc_reset_stats(9), lpfc_get_enc_info(9), lpfc_get_node_by_target(9), lpfc_get_starget_port_id(9), lpfc_get_starget_node_name(9), lpfc_get_starget_port_name(9), lpfc_set_rport_loss_tmo(9), lpfc_set_vport_symbolic_name(9), lpfc_hba_log_verbose_init(9), lpfc_get_hba_function_mode(9), lpfc_get_cfgparam(9)
• lpfc_nvme_mod_param_dep(9), lpfc_get_vport_cfgparam(9)

That's a hundred and ten entries, bestie. We counted. She ate. 👑

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💀 Real talk though: deprecated means deprecated. If you're writing new userspace mailbox code, the description literally points you at the bsg interface. Go there. sysfs_mbox_write is a nostalgia post now. 🙈

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✨ That's the whole page, hope it slayed ✨ Signed off with love from ./drivers/scsi/lpfc, dated October 2026, straight out of the Kernel API Manual — see you in the next one, bestie 🎀🦋💜