/* * scsi.c Copyright (C) 1992 Drew Eckhardt * Copyright (C) 1993, 1994, 1995, 1999 Eric Youngdale * Copyright (C) 2002, 2003 Christoph Hellwig * * generic mid-level SCSI driver * Initial versions: Drew Eckhardt * Subsequent revisions: Eric Youngdale * * <drew@colorado.edu> * * Bug correction thanks go to : * Rik Faith <faith@cs.unc.edu> * Tommy Thorn <tthorn> * Thomas Wuensche <tw@fgb1.fgb.mw.tu-muenchen.de> * * Modified by Eric Youngdale eric@andante.org or ericy@gnu.ai.mit.edu to * add scatter-gather, multiple outstanding request, and other * enhancements. * * Native multichannel, wide scsi, /proc/scsi and hot plugging * support added by Michael Neuffer <mike@i-connect.net> * * Added request_module("scsi_hostadapter") for kerneld: * (Put an "alias scsi_hostadapter your_hostadapter" in /etc/modprobe.conf) * Bjorn Ekwall <bj0rn@blox.se> * (changed to kmod) * * Major improvements to the timeout, abort, and reset processing, * as well as performance modifications for large queue depths by * Leonard N. Zubkoff <lnz@dandelion.com> * * Converted cli() code to spinlocks, Ingo Molnar * * Jiffies wrap fixes (host->resetting), 3 Dec 1998 Andrea Arcangeli * * out_of_space hacks, D. Gilbert (dpg) 990608 */ #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/kernel.h> #include <linux/timer.h> #include <linux/string.h> #include <linux/slab.h> #include <linux/blkdev.h> #include <linux/delay.h> #include <linux/init.h> #include <linux/completion.h> #include <linux/unistd.h> #include <linux/spinlock.h> #include <linux/kmod.h> #include <linux/interrupt.h> #include <linux/notifier.h> #include <linux/cpu.h> #include <linux/mutex.h> #include <linux/async.h> #include <asm/unaligned.h> #include <scsi/scsi.h> #include <scsi/scsi_cmnd.h> #include <scsi/scsi_dbg.h> #include <scsi/scsi_device.h> #include <scsi/scsi_driver.h> #include <scsi/scsi_eh.h> #include <scsi/scsi_host.h> #include <scsi/scsi_tcq.h> #include "scsi_priv.h" #include "scsi_logging.h" #define CREATE_TRACE_POINTS #include <trace/events/scsi.h> /* * Definitions and constants. */ /* * Note - the initial logging level can be set here to log events at boot time. * After the system is up, you may enable logging via the /proc interface. */ unsigned int scsi_logging_level; #if defined(CONFIG_SCSI_LOGGING) EXPORT_SYMBOL(scsi_logging_level); #endif /* sd, scsi core and power management need to coordinate flushing async actions */ ASYNC_DOMAIN(scsi_sd_probe_domain); EXPORT_SYMBOL(scsi_sd_probe_domain); /* * Separate domain (from scsi_sd_probe_domain) to maximize the benefit of * asynchronous system resume operations. It is marked 'exclusive' to avoid * being included in the async_synchronize_full() that is invoked by * dpm_resume() */ ASYNC_DOMAIN_EXCLUSIVE(scsi_sd_pm_domain); EXPORT_SYMBOL(scsi_sd_pm_domain); /** * scsi_put_command - Free a scsi command block * @cmd: command block to free * * Returns: Nothing. * * Notes: The command must not belong to any lists. */ void scsi_put_command(struct scsi_cmnd *cmd) { unsigned long flags; /* serious error if the command hasn't come from a device list */ spin_lock_irqsave(&cmd->device->list_lock, flags); BUG_ON(list_empty(&cmd->list)); list_del_init(&cmd->list); spin_unlock_irqrestore(&cmd->device->list_lock, flags); BUG_ON(delayed_work_pending(&cmd->abort_work)); } #ifdef CONFIG_SCSI_LOGGING void scsi_log_send(struct scsi_cmnd *cmd) { unsigned int level; /* * If ML QUEUE log level is greater than or equal to: * * 1: nothing (match completion) * * 2: log opcode + command of all commands + cmd address * * 3: same as 2 * * 4: same as 3 */ if (unlikely(scsi_logging_level)) { level = SCSI_LOG_LEVEL(SCSI_LOG_MLQUEUE_SHIFT, SCSI_LOG_MLQUEUE_BITS); if (level > 1) { scmd_printk(KERN_INFO, cmd, "Send: scmd 0x%p\n", cmd); scsi_print_command(cmd); } } } void scsi_log_completion(struct scsi_cmnd *cmd, int disposition) { unsigned int level; /* * If ML COMPLETE log level is greater than or equal to: * * 1: log disposition, result, opcode + command, and conditionally * sense data for failures or non SUCCESS dispositions. * * 2: same as 1 but for all command completions. * * 3: same as 2 * * 4: same as 3 plus dump extra junk */ if (unlikely(scsi_logging_level)) { level = SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT, SCSI_LOG_MLCOMPLETE_BITS); if (((level > 0) && (cmd->result || disposition != SUCCESS)) || (level > 1)) { scsi_print_result(cmd, "Done", disposition); scsi_print_command(cmd); if (status_byte(cmd->result) & CHECK_CONDITION) scsi_print_sense(cmd); if (level > 3) scmd_printk(KERN_INFO, cmd, "scsi host busy %d failed %d\n", atomic_read(&cmd->device->host->host_busy), cmd->device->host->host_failed); } } } #endif /** * scsi_cmd_get_serial - Assign a serial number to a command * @host: the scsi host * @cmd: command to assign serial number to * * Description: a serial number identifies a request for error recovery * and debugging purposes. Protected by the Host_Lock of host. */ void scsi_cmd_get_serial(struct Scsi_Host *host, struct scsi_cmnd *cmd) { cmd->serial_number = host->cmd_serial_number++; if (cmd->serial_number == 0) cmd->serial_number = host->cmd_serial_number++; } EXPORT_SYMBOL(scsi_cmd_get_serial); /** * scsi_finish_command - cleanup and pass command back to upper layer * @cmd: the command * * Description: Pass command off to upper layer for finishing of I/O * request, waking processes that are waiting on results, * etc. */ void scsi_finish_command(struct scsi_cmnd *cmd) { struct scsi_device *sdev = cmd->device; struct scsi_target *starget = scsi_target(sdev); struct Scsi_Host *shost = sdev->host; struct scsi_driver *drv; unsigned int good_bytes; scsi_device_unbusy(sdev); /* * Clear the flags that say that the device/target/host is no longer * capable of accepting new commands. */ if (atomic_read(&shost->host_blocked)) atomic_set(&shost->host_blocked, 0); if (atomic_read(&starget->target_blocked)) atomic_set(&starget->target_blocked, 0); if (atomic_read(&sdev->device_blocked)) atomic_set(&sdev->device_blocked, 0); /* * If we have valid sense information, then some kind of recovery * must have taken place. Make a note of this. */ if (SCSI_SENSE_VALID(cmd)) cmd->result |= (DRIVER_SENSE << 24); SCSI_LOG_MLCOMPLETE(4, sdev_printk(KERN_INFO, sdev, "Notifying upper driver of completion " "(result %x)\n", cmd->result)); good_bytes = scsi_bufflen(cmd); if (!blk_rq_is_passthrough(cmd->request)) { int old_good_bytes = good_bytes; drv = scsi_cmd_to_driver(cmd); if (drv->done) good_bytes = drv->done(cmd); /* * USB may not give sense identifying bad sector and * simply return a residue instead, so subtract off the * residue if drv->done() error processing indicates no * change to the completion length. */ if (good_bytes == old_good_bytes) good_bytes -= scsi_get_resid(cmd); } scsi_io_completion(cmd, good_bytes); } /** * scsi_change_queue_depth - change a device's queue depth * @sdev: SCSI Device in question * @depth: number of commands allowed to be queued to the driver * * Sets the device queue depth and returns the new value. */ int scsi_change_queue_depth(struct scsi_device *sdev, int depth) { if (depth > 0) { sdev->queue_depth = depth; wmb(); } if (sdev->request_queue) blk_set_queue_depth(sdev->request_queue, depth); return sdev->queue_depth; } EXPORT_SYMBOL(scsi_change_queue_depth); /** * scsi_track_queue_full - track QUEUE_FULL events to adjust queue depth * @sdev: SCSI Device in question * @depth: Current number of outstanding SCSI commands on this device, * not counting the one returned as QUEUE_FULL. * * Description: This function will track successive QUEUE_FULL events on a * specific SCSI device to determine if and when there is a * need to adjust the queue depth on the device. * * Returns: 0 - No change needed, >0 - Adjust queue depth to this new depth, * -1 - Drop back to untagged operation using host->cmd_per_lun * as the untagged command depth * * Lock Status: None held on entry * * Notes: Low level drivers may call this at any time and we will do * "The Right Thing." We are interrupt context safe. */ int scsi_track_queue_full(struct scsi_device *sdev, int depth) { /* * Don't let QUEUE_FULLs on the same * jiffies count, they could all be from * same event. */ if ((jiffies >> 4) == (sdev->last_queue_full_time >> 4)) return 0; sdev->last_queue_full_time = jiffies; if (sdev->last_queue_full_depth != depth) { sdev->last_queue_full_count = 1; sdev->last_queue_full_depth = depth; } else { sdev->last_queue_full_count++; } if (sdev->last_queue_full_count <= 10) return 0; return scsi_change_queue_depth(sdev, depth); } EXPORT_SYMBOL(scsi_track_queue_full); /** * scsi_vpd_inquiry - Request a device provide us with a VPD page * @sdev: The device to ask * @buffer: Where to put the result * @page: Which Vital Product Data to return * @len: The length of the buffer * * This is an internal helper function. You probably want to use * scsi_get_vpd_page instead. * * Returns size of the vpd page on success or a negative error number. */ static int scsi_vpd_inquiry(struct scsi_device *sdev, unsigned char *buffer, u8 page, unsigned len) { int result; unsigned char cmd[16]; if (len < 4) return -EINVAL; cmd[0] = INQUIRY; cmd[1] = 1; /* EVPD */ cmd[2] = page; cmd[3] = len >> 8; cmd[4] = len & 0xff; cmd[5] = 0; /* Control byte */ /* * I'm not convinced we need to try quite this hard to get VPD, but * all the existing users tried this hard. */ result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len, NULL, 30 * HZ, 3, NULL); if (result) return -EIO; /* Sanity check that we got the page back that we asked for */ if (buffer[1] != page) return -EIO; return get_unaligned_be16(&buffer[2]) + 4; } /** * scsi_get_vpd_page - Get Vital Product Data from a SCSI device * @sdev: The device to ask * @page: Which Vital Product Data to return * @buf: where to store the VPD * @buf_len: number of bytes in the VPD buffer area * * SCSI devices may optionally supply Vital Product Data. Each 'page' * of VPD is defined in the appropriate SCSI document (eg SPC, SBC). * If the device supports this VPD page, this routine returns a pointer * to a buffer containing the data from that page. The caller is * responsible for calling kfree() on this pointer when it is no longer * needed. If we cannot retrieve the VPD page this routine returns %NULL. */ int scsi_get_vpd_page(struct scsi_device *sdev, u8 page, unsigned char *buf, int buf_len) { int i, result; if (sdev->skip_vpd_pages) goto fail; /* Ask for all the pages supported by this device */ result = scsi_vpd_inquiry(sdev, buf, 0, buf_len); if (result < 4) goto fail; /* If the user actually wanted this page, we can skip the rest */ if (page == 0) return 0; for (i = 4; i < min(result, buf_len); i++) if (buf[i] == page) goto found; if (i < result && i >= buf_len) /* ran off the end of the buffer, give us benefit of doubt */ goto found; /* The device claims it doesn't support the requested page */ goto fail; found: result = scsi_vpd_inquiry(sdev, buf, page, buf_len); if (result < 0) goto fail; return 0; fail: return -EINVAL; } EXPORT_SYMBOL_GPL(scsi_get_vpd_page); /** * scsi_attach_vpd - Attach Vital Product Data to a SCSI device structure * @sdev: The device to ask * * Attach the 'Device Identification' VPD page (0x83) and the * 'Unit Serial Number' VPD page (0x80) to a SCSI device * structure. This information can be used to identify the device * uniquely. */ void scsi_attach_vpd(struct scsi_device *sdev) { int result, i; int vpd_len = SCSI_VPD_PG_LEN; int pg80_supported = 0; int pg83_supported = 0; unsigned char __rcu *vpd_buf, *orig_vpd_buf = NULL; if (!scsi_device_supports_vpd(sdev)) return; retry_pg0: vpd_buf = kmalloc(vpd_len, GFP_KERNEL); if (!vpd_buf) return; /* Ask for all the pages supported by this device */ result = scsi_vpd_inquiry(sdev, vpd_buf, 0, vpd_len); if (result < 0) { kfree(vpd_buf); return; } if (result > vpd_len) { vpd_len = result; kfree(vpd_buf); goto retry_pg0; } for (i = 4; i < result; i++) { if (vpd_buf[i] == 0x80) pg80_supported = 1; if (vpd_buf[i] == 0x83) pg83_supported = 1; } kfree(vpd_buf); vpd_len = SCSI_VPD_PG_LEN; if (pg80_supported) { retry_pg80: vpd_buf = kmalloc(vpd_len, GFP_KERNEL); if (!vpd_buf) return; result = scsi_vpd_inquiry(sdev, vpd_buf, 0x80, vpd_len); if (result < 0) { kfree(vpd_buf); return; } if (result > vpd_len) { vpd_len = result; kfree(vpd_buf); goto retry_pg80; } mutex_lock(&sdev->inquiry_mutex); orig_vpd_buf = sdev->vpd_pg80; sdev->vpd_pg80_len = result; rcu_assign_pointer(sdev->vpd_pg80, vpd_buf); mutex_unlock(&sdev->inquiry_mutex); synchronize_rcu(); if (orig_vpd_buf) { kfree(orig_vpd_buf); orig_vpd_buf = NULL; } vpd_len = SCSI_VPD_PG_LEN; } if (pg83_supported) { retry_pg83: vpd_buf = kmalloc(vpd_len, GFP_KERNEL); if (!vpd_buf) return; result = scsi_vpd_inquiry(sdev, vpd_buf, 0x83, vpd_len); if (result < 0) { kfree(vpd_buf); return; } if (result > vpd_len) { vpd_len = result; kfree(vpd_buf); goto retry_pg83; } mutex_lock(&sdev->inquiry_mutex); orig_vpd_buf = sdev->vpd_pg83; sdev->vpd_pg83_len = result; rcu_assign_pointer(sdev->vpd_pg83, vpd_buf); mutex_unlock(&sdev->inquiry_mutex); synchronize_rcu(); if (orig_vpd_buf) kfree(orig_vpd_buf); } } /** * scsi_report_opcode - Find out if a given command opcode is supported * @sdev: scsi device to query * @buffer: scratch buffer (must be at least 20 bytes long) * @len: length of buffer * @opcode: opcode for command to look up * * Uses the REPORT SUPPORTED OPERATION CODES to look up the given * opcode. Returns -EINVAL if RSOC fails, 0 if the command opcode is * unsupported and 1 if the device claims to support the command. */ int scsi_report_opcode(struct scsi_device *sdev, unsigned char *buffer, unsigned int len, unsigned char opcode) { unsigned char cmd[16]; struct scsi_sense_hdr sshdr; int result; if (sdev->no_report_opcodes || sdev->scsi_level < SCSI_SPC_3) return -EINVAL; memset(cmd, 0, 16); cmd[0] = MAINTENANCE_IN; cmd[1] = MI_REPORT_SUPPORTED_OPERATION_CODES; cmd[2] = 1; /* One command format */ cmd[3] = opcode; put_unaligned_be32(len, &cmd[6]); memset(buffer, 0, len); result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len, &sshdr, 30 * HZ, 3, NULL); if (result && scsi_sense_valid(&sshdr) && sshdr.sense_key == ILLEGAL_REQUEST && (sshdr.asc == 0x20 || sshdr.asc == 0x24) && sshdr.ascq == 0x00) return -EINVAL; if ((buffer[1] & 3) == 3) /* Command supported */ return 1; return 0; } EXPORT_SYMBOL(scsi_report_opcode); /** * scsi_device_get - get an additional reference to a scsi_device * @sdev: device to get a reference to * * Description: Gets a reference to the scsi_device and increments the use count * of the underlying LLDD module. You must hold host_lock of the * parent Scsi_Host or already have a reference when calling this. * * This will fail if a device is deleted or cancelled, or when the LLD module * is in the process of being unloaded. */ int scsi_device_get(struct scsi_device *sdev) { if (sdev->sdev_state == SDEV_DEL || sdev->sdev_state == SDEV_CANCEL) goto fail; if (!get_device(&sdev->sdev_gendev)) goto fail; if (!try_module_get(sdev->host->hostt->module)) goto fail_put_device; return 0; fail_put_device: put_device(&sdev->sdev_gendev); fail: return -ENXIO; } EXPORT_SYMBOL(scsi_device_get); /** * scsi_device_put - release a reference to a scsi_device * @sdev: device to release a reference on. * * Description: Release a reference to the scsi_device and decrements the use * count of the underlying LLDD module. The device is freed once the last * user vanishes. */ void scsi_device_put(struct scsi_device *sdev) { module_put(sdev->host->hostt->module); put_device(&sdev->sdev_gendev); } EXPORT_SYMBOL(scsi_device_put); /* helper for shost_for_each_device, see that for documentation */ struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *shost, struct scsi_device *prev) { struct list_head *list = (prev ? &prev->siblings : &shost->__devices); struct scsi_device *next = NULL; unsigned long flags; spin_lock_irqsave(shost->host_lock, flags); while (list->next != &shost->__devices) { next = list_entry(list->next, struct scsi_device, siblings); /* skip devices that we can't get a reference to */ if (!scsi_device_get(next)) break; next = NULL; list = list->next; } spin_unlock_irqrestore(shost->host_lock, flags); if (prev) scsi_device_put(prev); return next; } EXPORT_SYMBOL(__scsi_iterate_devices); /** * starget_for_each_device - helper to walk all devices of a target * @starget: target whose devices we want to iterate over. * @data: Opaque passed to each function call. * @fn: Function to call on each device * * This traverses over each device of @starget. The devices have * a reference that must be released by scsi_host_put when breaking * out of the loop. */ void starget_for_each_device(struct scsi_target *starget, void *data, void (*fn)(struct scsi_device *, void *)) { struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); struct scsi_device *sdev; shost_for_each_device(sdev, shost) { if ((sdev->channel == starget->channel) && (sdev->id == starget->id)) fn(sdev, data); } } EXPORT_SYMBOL(starget_for_each_device); /** * __starget_for_each_device - helper to walk all devices of a target (UNLOCKED) * @starget: target whose devices we want to iterate over. * @data: parameter for callback @fn() * @fn: callback function that is invoked for each device * * This traverses over each device of @starget. It does _not_ * take a reference on the scsi_device, so the whole loop must be * protected by shost->host_lock. * * 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 starget_for_each_device instead. **/ void __starget_for_each_device(struct scsi_target *starget, void *data, void (*fn)(struct scsi_device *, void *)) { struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); struct scsi_device *sdev; __shost_for_each_device(sdev, shost) { if ((sdev->channel == starget->channel) && (sdev->id == starget->id)) fn(sdev, data); } } EXPORT_SYMBOL(__starget_for_each_device); /** * __scsi_device_lookup_by_target - find a device given the target (UNLOCKED) * @starget: SCSI target pointer * @lun: SCSI Logical Unit Number * * Description: Looks up the scsi_device with the specified @lun for a given * @starget. The returned scsi_device does not have an additional * reference. You must hold the host's host_lock over this call and * any access to the returned scsi_device. A scsi_device in state * SDEV_DEL is skipped. * * Note: The only reason why drivers should use this is because * they need to access the device list in irq context. Otherwise you * really want to use scsi_device_lookup_by_target instead. **/ struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *starget, u64 lun) { struct scsi_device *sdev; list_for_each_entry(sdev, &starget->devices, same_target_siblings) { if (sdev->sdev_state == SDEV_DEL) continue; if (sdev->lun ==lun) return sdev; } return NULL; } EXPORT_SYMBOL(__scsi_device_lookup_by_target); /** * scsi_device_lookup_by_target - find a device given the target * @starget: SCSI target pointer * @lun: SCSI Logical Unit Number * * Description: Looks up the scsi_device with the specified @lun for a given * @starget. The returned scsi_device has an additional reference that * needs to be released with scsi_device_put once you're done with it. **/ struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *starget, u64 lun) { struct scsi_device *sdev; struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); unsigned long flags; spin_lock_irqsave(shost->host_lock, flags); sdev = __scsi_device_lookup_by_target(starget, lun); if (sdev && scsi_device_get(sdev)) sdev = NULL; spin_unlock_irqrestore(shost->host_lock, flags); return sdev; } EXPORT_SYMBOL(scsi_device_lookup_by_target); /** * __scsi_device_lookup - find a device given the host (UNLOCKED) * @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. You must hold the host's host_lock over this call and any access * to the returned scsi_device. * * 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. **/ struct scsi_device *__scsi_device_lookup(struct Scsi_Host *shost, uint channel, uint id, u64 lun) { struct scsi_device *sdev; list_for_each_entry(sdev, &shost->__devices, siblings) { if (sdev->channel == channel && sdev->id == id && sdev->lun ==lun) return sdev; } return NULL; } EXPORT_SYMBOL(__scsi_device_lookup); /** * scsi_device_lookup - find a device given the host * @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 has an additional reference that * needs to be released with scsi_device_put once you're done with it. **/ struct scsi_device *scsi_device_lookup(struct Scsi_Host *shost, uint channel, uint id, u64 lun) { struct scsi_device *sdev; unsigned long flags; spin_lock_irqsave(shost->host_lock, flags); sdev = __scsi_device_lookup(shost, channel, id, lun); if (sdev && scsi_device_get(sdev)) sdev = NULL; spin_unlock_irqrestore(shost->host_lock, flags); return sdev; } EXPORT_SYMBOL(scsi_device_lookup); MODULE_DESCRIPTION("SCSI core"); MODULE_LICENSE("GPL"); module_param(scsi_logging_level, int, S_IRUGO|S_IWUSR); MODULE_PARM_DESC(scsi_logging_level, "a bit mask of logging levels"); #ifdef CONFIG_SCSI_MQ_DEFAULT bool scsi_use_blk_mq = true; #else bool scsi_use_blk_mq = false; #endif module_param_named(use_blk_mq, scsi_use_blk_mq, bool, S_IWUSR | S_IRUGO); static int __init init_scsi(void) { int error; error = scsi_init_queue(); if (error) return error; error = scsi_init_procfs(); if (error) goto cleanup_queue; error = scsi_init_devinfo(); if (error) goto cleanup_procfs; error = scsi_init_hosts(); if (error) goto cleanup_devlist; error = scsi_init_sysctl(); if (error) goto cleanup_hosts; error = scsi_sysfs_register(); if (error) goto cleanup_sysctl; scsi_netlink_init(); printk(KERN_NOTICE "SCSI subsystem initialized\n"); return 0; cleanup_sysctl: scsi_exit_sysctl(); cleanup_hosts: scsi_exit_hosts(); cleanup_devlist: scsi_exit_devinfo(); cleanup_procfs: scsi_exit_procfs(); cleanup_queue: scsi_exit_queue(); printk(KERN_ERR "SCSI subsystem failed to initialize, error = %d\n", -error); return error; } static void __exit exit_scsi(void) { scsi_netlink_exit(); scsi_sysfs_unregister(); scsi_exit_sysctl(); scsi_exit_hosts(); scsi_exit_devinfo(); scsi_exit_procfs(); scsi_exit_queue(); async_unregister_domain(&scsi_sd_probe_domain); } subsys_initcall(init_scsi); module_exit(exit_scsi);