__scsi_device_lookup(9)

💖 __scsi_device_lookup(9) 💖

okay so bestie, welcome to the Kernel API Manual ✨ — this is the page for __scsi_device_lookup(9), and the whole vibe is “find a device given the host, but make it UNLOCKED.” The (UNLOCKED) is literally right there in the name, so bestie please keep that in mind 🫶

🎀 NAME 🎀

__scsi_device_lookup — find a device given the host (UNLOCKED).

✨ SYNOPSIS ✨

struct scsi_device * __scsi_device_lookup (struct Scsi_Host *shost , uint channel , uint id , u64 lun );

🌸 ARGUMENTS 🌸

• shost — SCSI host pointer
• channel — SCSI channel (zero if only one channel)
• id — SCSI target number (physical unit number)
• lun — SCSI Logical Unit Number

🦋 DESCRIPTION 🦋

Looks up the scsi_device with the specified channel, id, lun for a given host. The returned scsi_device does not have an additional reference.

🚨 lock warning, bestie: you must hold the host's host_lock over this call and any access to the returned scsi_device. No cap, that part is not optional 💅

💀 NOTE 💀

The only reason why drivers would want to use this is because they need to access the device list in irq context. Otherwise you really want to use scsi_device_lookup instead. It's giving “special-case energy,” iykyk 🙈

🔥 SEE ALSO 🔥

Kernel file ./drivers/scsi/scsi.c — plus the whole friend group:

• scsi_finish_command(9)
• scsi_change_queue_depth(9)
• scsi_track_queue_full(9)
• scsi_vpd_inquiry(9)
• scsi_get_vpd_page(9)
• scsi_get_vpd_buf(9)
• scsi_attach_vpd(9)
• scsi_report_opcode(9)
• scsi_cdl_check(9)
• scsi_cdl_enable(9)
• scsi_device_get(9)
• scsi_device_put(9)
• starget_for_each_device(9)
• __starget_for_each_device(9)
• __scsi_device_lookup_by_target(9)
• scsi_device_lookup_by_target(9)
• scsi_device_lookup(9)

that's the whole page, bestie 💅 — source/version is ./drivers/scsi, date is October 2026, and the star of the show is __scsi_device_lookup(9). slay and bye 🎀✨