diff options
Diffstat (limited to 'drivers/scsi/scsi_scan.c')
| -rw-r--r-- | drivers/scsi/scsi_scan.c | 521 |
1 files changed, 374 insertions, 147 deletions
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c index dd0d516f65e2..7acbfcfc2172 100644 --- a/drivers/scsi/scsi_scan.c +++ b/drivers/scsi/scsi_scan.c @@ -35,7 +35,7 @@ #include <linux/spinlock.h> #include <linux/async.h> #include <linux/slab.h> -#include <asm/unaligned.h> +#include <linux/unaligned.h> #include <scsi/scsi.h> #include <scsi/scsi_cmnd.h> @@ -97,7 +97,7 @@ MODULE_PARM_DESC(max_luns, #define SCSI_SCAN_TYPE_DEFAULT "sync" #endif -char scsi_scan_type[7] = SCSI_SCAN_TYPE_DEFAULT; +static char scsi_scan_type[7] = SCSI_SCAN_TYPE_DEFAULT; module_param_string(scan, scsi_scan_type, sizeof(scsi_scan_type), S_IRUGO|S_IWUSR); @@ -122,6 +122,22 @@ struct async_scan_data { struct completion prev_finished; }; +/* + * scsi_enable_async_suspend - Enable async suspend and resume + */ +void scsi_enable_async_suspend(struct device *dev) +{ + /* + * If a user has disabled async probing a likely reason is due to a + * storage enclosure that does not inject staggered spin-ups. For + * safety, make resume synchronous as well in that case. + */ + if (strncmp(scsi_scan_type, "async", 5) != 0) + return; + /* Enable asynchronous suspend and resume. */ + device_enable_async_suspend(dev); +} + /** * scsi_complete_async_scans - Wait for asynchronous scans to complete * @@ -135,8 +151,9 @@ int scsi_complete_async_scans(void) struct async_scan_data *data; do { - if (list_empty(&scanning_hosts)) - return 0; + scoped_guard(spinlock, &async_scan_lock) + if (list_empty(&scanning_hosts)) + return 0; /* If we can't get memory immediately, that's OK. Just * sleep a little. Even if we never get memory, the async * scans will finish eventually. @@ -194,15 +211,63 @@ static void scsi_unlock_floptical(struct scsi_device *sdev, scsi_cmd[3] = 0; scsi_cmd[4] = 0x2a; /* size */ scsi_cmd[5] = 0; - scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, result, 0x2a, NULL, + scsi_execute_cmd(sdev, scsi_cmd, REQ_OP_DRV_IN, result, 0x2a, SCSI_TIMEOUT, 3, NULL); } +static int scsi_realloc_sdev_budget_map(struct scsi_device *sdev, + unsigned int depth) +{ + int new_shift = sbitmap_calculate_shift(depth); + bool need_alloc = !sdev->budget_map.map; + bool need_free = false; + unsigned int memflags; + int ret; + struct sbitmap sb_backup; + + depth = min_t(unsigned int, depth, scsi_device_max_queue_depth(sdev)); + + /* + * realloc if new shift is calculated, which is caused by setting + * up one new default queue depth after calling ->sdev_configure + */ + if (!need_alloc && new_shift != sdev->budget_map.shift) + need_alloc = need_free = true; + + if (!need_alloc) + return 0; + + /* + * Request queue has to be frozen for reallocating budget map, + * and here disk isn't added yet, so freezing is pretty fast + */ + if (need_free) { + memflags = blk_mq_freeze_queue(sdev->request_queue); + sb_backup = sdev->budget_map; + } + ret = sbitmap_init_node(&sdev->budget_map, + scsi_device_max_queue_depth(sdev), + new_shift, GFP_NOIO, + sdev->request_queue->node, false, true); + if (!ret) + sbitmap_resize(&sdev->budget_map, depth); + + if (need_free) { + if (ret) + sdev->budget_map = sb_backup; + else + sbitmap_free(&sb_backup); + ret = 0; + blk_mq_unfreeze_queue(sdev->request_queue, memflags); + } + return ret; +} + /** * scsi_alloc_sdev - allocate and setup a scsi_Device * @starget: which target to allocate a &scsi_device for * @lun: which lun - * @hostdata: usually NULL and set by ->slave_alloc instead + * @hostdata: usually NULL and set by ->sdev_init instead * * Description: * Allocate, initialize for io, and return a pointer to a scsi_Device. @@ -215,12 +280,15 @@ static void scsi_unlock_floptical(struct scsi_device *sdev, static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget, u64 lun, void *hostdata) { + unsigned int depth; struct scsi_device *sdev; + struct request_queue *q; int display_failure_msg = 1, ret; struct Scsi_Host *shost = dev_to_shost(starget->dev.parent); + struct queue_limits lim; sdev = kzalloc(sizeof(*sdev) + shost->transportt->device_size, - GFP_ATOMIC); + GFP_KERNEL); if (!sdev) goto out; @@ -236,7 +304,6 @@ static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget, sdev->sdev_state = SDEV_CREATED; INIT_LIST_HEAD(&sdev->siblings); INIT_LIST_HEAD(&sdev->same_target_siblings); - INIT_LIST_HEAD(&sdev->cmd_list); INIT_LIST_HEAD(&sdev->starved_entry); INIT_LIST_HEAD(&sdev->event_list); spin_lock_init(&sdev->list_lock); @@ -247,11 +314,11 @@ static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget, sdev->sdev_gendev.parent = get_device(&starget->dev); sdev->sdev_target = starget; - /* usually NULL and set by ->slave_alloc instead */ + /* usually NULL and set by ->sdev_init instead */ sdev->hostdata = hostdata; /* if the device needs this changing, it may do so in the - * slave_configure function */ + * sdev_configure function */ sdev->max_device_blocked = SCSI_DEFAULT_DEVICE_BLOCKED; /* @@ -266,24 +333,43 @@ static struct scsi_device *scsi_alloc_sdev(struct scsi_target *starget, */ sdev->borken = 1; - sdev->request_queue = scsi_mq_alloc_queue(sdev); - if (!sdev->request_queue) { + sdev->sg_reserved_size = INT_MAX; + + scsi_init_limits(shost, &lim); + q = blk_mq_alloc_queue(&sdev->host->tag_set, &lim, sdev); + if (IS_ERR(q)) { /* release fn is set up in scsi_sysfs_device_initialise, so * have to free and put manually here */ put_device(&starget->dev); kfree(sdev); goto out; } - WARN_ON_ONCE(!blk_get_queue(sdev->request_queue)); - sdev->request_queue->queuedata = sdev; - - scsi_change_queue_depth(sdev, sdev->host->cmd_per_lun ? - sdev->host->cmd_per_lun : 1); + kref_get(&sdev->host->tagset_refcnt); + sdev->request_queue = q; scsi_sysfs_device_initialize(sdev); - if (shost->hostt->slave_alloc) { - ret = shost->hostt->slave_alloc(sdev); + if (scsi_device_is_pseudo_dev(sdev)) + return sdev; + + depth = sdev->host->cmd_per_lun ?: 1; + + /* + * Use .can_queue as budget map's depth because we have to + * support adjusting queue depth from sysfs. Meantime use + * default device queue depth to figure out sbitmap shift + * since we use this queue depth most of times. + */ + if (scsi_realloc_sdev_budget_map(sdev, depth)) { + put_device(&starget->dev); + kfree(sdev); + goto out; + } + + scsi_change_queue_depth(sdev, depth); + + if (shost->hostt->sdev_init) { + ret = shost->hostt->sdev_init(sdev); if (ret) { /* * if LLDD reports slave not present, don't clutter @@ -331,7 +417,7 @@ static void scsi_target_dev_release(struct device *dev) put_device(parent); } -static struct device_type scsi_target_type = { +static const struct device_type scsi_target_type = { .name = "scsi_target", .release = scsi_target_dev_release, }; @@ -431,6 +517,7 @@ static struct scsi_target *scsi_alloc_target(struct device *parent, dev_set_name(dev, "target%d:%d:%d", shost->host_no, channel, id); dev->bus = &scsi_bus_type; dev->type = &scsi_target_type; + scsi_enable_async_suspend(dev); starget->id = id; starget->channel = channel; starget->can_queue = 0; @@ -454,7 +541,8 @@ static struct scsi_target *scsi_alloc_target(struct device *parent, error = shost->hostt->target_alloc(starget); if(error) { - dev_printk(KERN_ERR, dev, "target allocation failed, error %d\n", error); + if (error != -ENXIO) + dev_err(dev, "target allocation failed, error %d\n", error); /* don't want scsi_target_reap to do the final * put because it will be under the host lock */ scsi_target_destroy(starget); @@ -543,6 +631,7 @@ void scsi_sanitize_inquiry_string(unsigned char *s, int len) } EXPORT_SYMBOL(scsi_sanitize_inquiry_string); + /** * scsi_probe_lun - probe a single LUN using a SCSI INQUIRY * @sdev: scsi_device to probe @@ -563,8 +652,38 @@ static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result, unsigned char scsi_cmd[MAX_COMMAND_SIZE]; int first_inquiry_len, try_inquiry_len, next_inquiry_len; int response_len = 0; - int pass, count, result; - struct scsi_sense_hdr sshdr; + int pass, count, result, resid; + struct scsi_failure failure_defs[] = { + /* + * not-ready to ready transition [asc/ascq=0x28/0x0] or + * power-on, reset [asc/ascq=0x29/0x0], continue. INQUIRY + * should not yield UNIT_ATTENTION but many buggy devices do + * so anyway. + */ + { + .sense = UNIT_ATTENTION, + .asc = 0x28, + .result = SAM_STAT_CHECK_CONDITION, + }, + { + .sense = UNIT_ATTENTION, + .asc = 0x29, + .result = SAM_STAT_CHECK_CONDITION, + }, + { + .allowed = 1, + .result = DID_TIME_OUT << 16, + }, + {} + }; + struct scsi_failures failures = { + .total_allowed = 3, + .failure_definitions = failure_defs, + }; + const struct scsi_exec_args exec_args = { + .resid = &resid, + .failures = &failures, + }; *bflags = 0; @@ -581,40 +700,25 @@ static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result, pass, try_inquiry_len)); /* Each pass gets up to three chances to ignore Unit Attention */ - for (count = 0; count < 3; ++count) { - int resid; + scsi_failures_reset_retries(&failures); + for (count = 0; count < 3; ++count) { memset(scsi_cmd, 0, 6); scsi_cmd[0] = INQUIRY; scsi_cmd[4] = (unsigned char) try_inquiry_len; memset(inq_result, 0, try_inquiry_len); - result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, - inq_result, try_inquiry_len, &sshdr, + result = scsi_execute_cmd(sdev, scsi_cmd, REQ_OP_DRV_IN, + inq_result, try_inquiry_len, HZ / 2 + HZ * scsi_inq_timeout, 3, - &resid); + &exec_args); SCSI_LOG_SCAN_BUS(3, sdev_printk(KERN_INFO, sdev, "scsi scan: INQUIRY %s with code 0x%x\n", result ? "failed" : "successful", result)); - if (result) { - /* - * not-ready to ready transition [asc/ascq=0x28/0x0] - * or power-on, reset [asc/ascq=0x29/0x0], continue. - * INQUIRY should not yield UNIT_ATTENTION - * but many buggy devices do so anyway. - */ - if (driver_byte(result) == DRIVER_SENSE && - scsi_sense_valid(&sshdr)) { - if ((sshdr.sense_key == UNIT_ATTENTION) && - ((sshdr.asc == 0x28) || - (sshdr.asc == 0x29)) && - (sshdr.ascq == 0)) - continue; - } - } else { + if (result == 0) { /* * if nothing was transferred, we try * again. It's a workaround for some USB @@ -650,7 +754,17 @@ static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result, if (pass == 1) { if (BLIST_INQUIRY_36 & *bflags) next_inquiry_len = 36; - else if (sdev->inquiry_len) + /* + * LLD specified a maximum sdev->inquiry_len + * but device claims it has more data. Capping + * the length only makes sense for legacy + * devices. If a device supports SPC-4 (2014) + * or newer, assume that it is safe to ask for + * as much as the device says it supports. + */ + else if (sdev->inquiry_len && + response_len > sdev->inquiry_len && + (inq_result[2] & 0x7) < 6) /* SPC-4 */ next_inquiry_len = sdev->inquiry_len; else next_inquiry_len = response_len; @@ -727,7 +841,7 @@ static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result, * device is attached at LUN 0 (SCSI_SCAN_TARGET_PRESENT) so * non-zero LUNs can be scanned. */ - sdev->scsi_level = inq_result[2] & 0x07; + sdev->scsi_level = inq_result[2] & 0x0f; if (sdev->scsi_level >= 2 || (sdev->scsi_level == 1 && (inq_result[3] & 0x0f) == 1)) sdev->scsi_level++; @@ -764,6 +878,8 @@ static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result, static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result, blist_flags_t *bflags, int async) { + const struct scsi_host_template *hostt = sdev->host->hostt; + struct queue_limits lim; int ret; /* @@ -788,7 +904,7 @@ static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result, */ sdev->inquiry = kmemdup(inq_result, max_t(size_t, sdev->inquiry_len, 36), - GFP_ATOMIC); + GFP_KERNEL); if (sdev->inquiry == NULL) return SCSI_SCAN_NO_RESPONSE; @@ -796,7 +912,8 @@ static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result, sdev->model = (char *) (sdev->inquiry + 16); sdev->rev = (char *) (sdev->inquiry + 32); - if (strncmp(sdev->vendor, "ATA ", 8) == 0) { + sdev->is_ata = strncmp(sdev->vendor, "ATA ", 8) == 0; + if (sdev->is_ata) { /* * sata emulation layer device. This is a hack to work around * the SATL power management specifications which state that @@ -895,19 +1012,6 @@ static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result, sdev->select_no_atn = 1; /* - * Maximum 512 sector transfer length - * broken RA4x00 Compaq Disk Array - */ - if (*bflags & BLIST_MAX_512) - blk_queue_max_hw_sectors(sdev->request_queue, 512); - /* - * Max 1024 sector transfer length for targets that report incorrect - * max/optimal lengths and relied on the old block layer safe default - */ - else if (*bflags & BLIST_MAX_1024) - blk_queue_max_hw_sectors(sdev->request_queue, 1024); - - /* * Some devices may not want to have a start command automatically * issued when a device is added. */ @@ -952,6 +1056,9 @@ static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result, if (*bflags & BLIST_UNMAP_LIMIT_WS) sdev->unmap_limit_for_ws = 1; + if (*bflags & BLIST_IGN_MEDIA_CHANGE) + sdev->ignore_media_change = 1; + sdev->eh_timeout = SCSI_DEFAULT_EH_TIMEOUT; if (*bflags & BLIST_TRY_VPD_PAGES) @@ -959,28 +1066,61 @@ static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result, else if (*bflags & BLIST_SKIP_VPD_PAGES) sdev->skip_vpd_pages = 1; + if (*bflags & BLIST_NO_VPD_SIZE) + sdev->no_vpd_size = 1; + transport_configure_device(&sdev->sdev_gendev); - if (sdev->host->hostt->slave_configure) { - ret = sdev->host->hostt->slave_configure(sdev); - if (ret) { - /* - * if LLDD reports slave not present, don't clutter - * console with alloc failure messages - */ - if (ret != -ENXIO) { - sdev_printk(KERN_ERR, sdev, - "failed to configure device\n"); - } - return SCSI_SCAN_NO_RESPONSE; - } + sdev->sdev_bflags = *bflags; + + if (scsi_device_is_pseudo_dev(sdev)) + return SCSI_SCAN_LUN_PRESENT; + + /* + * No need to freeze the queue as it isn't reachable to anyone else yet. + */ + lim = queue_limits_start_update(sdev->request_queue); + if (*bflags & BLIST_MAX_512) + lim.max_hw_sectors = 512; + else if (*bflags & BLIST_MAX_1024) + lim.max_hw_sectors = 1024; + + if (hostt->sdev_configure) + ret = hostt->sdev_configure(sdev, &lim); + if (ret) { + queue_limits_cancel_update(sdev->request_queue); + /* + * If the LLDD reports device not present, don't clutter the + * console with failure messages. + */ + if (ret != -ENXIO) + sdev_printk(KERN_ERR, sdev, + "failed to configure device\n"); + return SCSI_SCAN_NO_RESPONSE; + } + + ret = queue_limits_commit_update(sdev->request_queue, &lim); + if (ret) { + sdev_printk(KERN_ERR, sdev, "failed to apply queue limits.\n"); + return SCSI_SCAN_NO_RESPONSE; } + /* + * The queue_depth is often changed in ->sdev_configure. + * + * Set up budget map again since memory consumption of the map depends + * on actual queue depth. + */ + if (hostt->sdev_configure) + scsi_realloc_sdev_budget_map(sdev, sdev->queue_depth); + if (sdev->scsi_level >= SCSI_3) scsi_attach_vpd(sdev); + scsi_cdl_check(sdev); + sdev->max_queue_depth = sdev->queue_depth; - sdev->sdev_bflags = *bflags; + WARN_ON_ONCE(sdev->max_queue_depth > sdev->budget_map.depth); /* * Ok, the device is now all set up, we can @@ -1079,8 +1219,13 @@ static int scsi_probe_and_add_lun(struct scsi_target *starget, if (!sdev) goto out; - result = kmalloc(result_len, GFP_ATOMIC | - ((shost->unchecked_isa_dma) ? __GFP_DMA : 0)); + if (scsi_device_is_pseudo_dev(sdev)) { + if (bflagsp) + *bflagsp = BLIST_NOLUN; + return SCSI_SCAN_LUN_PRESENT; + } + + result = kmalloc(result_len, GFP_KERNEL); if (!result) goto out_free_sdev; @@ -1292,12 +1437,35 @@ static int scsi_report_lun_scan(struct scsi_target *starget, blist_flags_t bflag unsigned int length; u64 lun; unsigned int num_luns; - unsigned int retries; int result; struct scsi_lun *lunp, *lun_data; - struct scsi_sense_hdr sshdr; struct scsi_device *sdev; struct Scsi_Host *shost = dev_to_shost(&starget->dev); + struct scsi_failure failure_defs[] = { + { + .sense = UNIT_ATTENTION, + .asc = SCMD_FAILURE_ASC_ANY, + .ascq = SCMD_FAILURE_ASCQ_ANY, + .result = SAM_STAT_CHECK_CONDITION, + }, + /* Fail all CCs except the UA above */ + { + .sense = SCMD_FAILURE_SENSE_ANY, + .result = SAM_STAT_CHECK_CONDITION, + }, + /* Retry any other errors not listed above */ + { + .result = SCMD_FAILURE_RESULT_ANY, + }, + {} + }; + struct scsi_failures failures = { + .total_allowed = 3, + .failure_definitions = failure_defs, + }; + const struct scsi_exec_args exec_args = { + .failures = &failures, + }; int ret = 0; /* @@ -1336,8 +1504,7 @@ static int scsi_report_lun_scan(struct scsi_target *starget, blist_flags_t bflag */ length = (511 + 1) * sizeof(struct scsi_lun); retry: - lun_data = kmalloc(length, GFP_KERNEL | - (sdev->host->unchecked_isa_dma ? __GFP_DMA : 0)); + lun_data = kmalloc(length, GFP_KERNEL); if (!lun_data) { printk(ALLOC_FAILURE_MSG, __func__); goto out; @@ -1368,28 +1535,18 @@ retry: * should come through as a check condition, and will not generate * a retry. */ - for (retries = 0; retries < 3; retries++) { - SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev, - "scsi scan: Sending REPORT LUNS to (try %d)\n", - retries)); - - result = scsi_execute_req(sdev, scsi_cmd, DMA_FROM_DEVICE, - lun_data, length, &sshdr, - SCSI_REPORT_LUNS_TIMEOUT, 3, NULL); - - SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev, - "scsi scan: REPORT LUNS" - " %s (try %d) result 0x%x\n", - result ? "failed" : "successful", - retries, result)); - if (result == 0) - break; - else if (scsi_sense_valid(&sshdr)) { - if (sshdr.sense_key != UNIT_ATTENTION) - break; - } - } + scsi_failures_reset_retries(&failures); + SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev, + "scsi scan: Sending REPORT LUNS\n")); + + result = scsi_execute_cmd(sdev, scsi_cmd, REQ_OP_DRV_IN, lun_data, + length, SCSI_REPORT_LUNS_TIMEOUT, 3, + &exec_args); + + SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev, + "scsi scan: REPORT LUNS %s result 0x%x\n", + result ? "failed" : "successful", result)); if (result) { /* * The device probably does not support a REPORT LUN command @@ -1476,7 +1633,8 @@ struct scsi_device *__scsi_add_device(struct Scsi_Host *shost, uint channel, scsi_complete_async_scans(); if (scsi_host_scan_allowed(shost) && scsi_autopm_get_host(shost) == 0) { - scsi_probe_and_add_lun(starget, lun, NULL, &sdev, 1, hostdata); + scsi_probe_and_add_lun(starget, lun, NULL, &sdev, + SCSI_SCAN_RESCAN, hostdata); scsi_autopm_put_host(shost); } mutex_unlock(&shost->scan_mutex); @@ -1492,6 +1650,24 @@ struct scsi_device *__scsi_add_device(struct Scsi_Host *shost, uint channel, } EXPORT_SYMBOL(__scsi_add_device); +/** + * scsi_add_device - creates a new SCSI (LU) instance + * @host: the &Scsi_Host instance where the device is located + * @channel: target channel number (rarely other than %0) + * @target: target id number + * @lun: LUN of target device + * + * Probe for a specific LUN and add it if found. + * + * Notes: This call is usually performed internally during a SCSI + * bus scan when an HBA is added (i.e. scsi_scan_host()). So it + * should only be called if the HBA becomes aware of a new SCSI + * device (LU) after scsi_scan_host() has completed. If successful + * this call can lead to sdev_init() and sdev_configure() callbacks + * into the LLD. + * + * Return: %0 on success or negative error code on failure + */ int scsi_add_device(struct Scsi_Host *host, uint channel, uint target, u64 lun) { @@ -1505,13 +1681,61 @@ int scsi_add_device(struct Scsi_Host *host, uint channel, } EXPORT_SYMBOL(scsi_add_device); -void scsi_rescan_device(struct device *dev) +int scsi_resume_device(struct scsi_device *sdev) +{ + struct device *dev = &sdev->sdev_gendev; + int ret = 0; + + device_lock(dev); + + /* + * Bail out if the device or its queue are not running. Otherwise, + * the rescan may block waiting for commands to be executed, with us + * holding the device lock. This can result in a potential deadlock + * in the power management core code when system resume is on-going. + */ + if (sdev->sdev_state != SDEV_RUNNING || + blk_queue_pm_only(sdev->request_queue)) { + ret = -EWOULDBLOCK; + goto unlock; + } + + if (dev->driver && try_module_get(dev->driver->owner)) { + struct scsi_driver *drv = to_scsi_driver(dev->driver); + + if (drv->resume) + ret = drv->resume(dev); + module_put(dev->driver->owner); + } + +unlock: + device_unlock(dev); + + return ret; +} +EXPORT_SYMBOL(scsi_resume_device); + +int scsi_rescan_device(struct scsi_device *sdev) { - struct scsi_device *sdev = to_scsi_device(dev); + struct device *dev = &sdev->sdev_gendev; + int ret = 0; device_lock(dev); + /* + * Bail out if the device or its queue are not running. Otherwise, + * the rescan may block waiting for commands to be executed, with us + * holding the device lock. This can result in a potential deadlock + * in the power management core code when system resume is on-going. + */ + if (sdev->sdev_state != SDEV_RUNNING || + blk_queue_pm_only(sdev->request_queue)) { + ret = -EWOULDBLOCK; + goto unlock; + } + scsi_attach_vpd(sdev); + scsi_cdl_check(sdev); if (sdev->handler && sdev->handler->rescan) sdev->handler->rescan(sdev); @@ -1523,7 +1747,11 @@ void scsi_rescan_device(struct device *dev) drv->rescan(dev); module_put(dev->driver->owner); } + +unlock: device_unlock(dev); + + return ret; } EXPORT_SYMBOL(scsi_rescan_device); @@ -1685,7 +1913,7 @@ int scsi_scan_host_selected(struct Scsi_Host *shost, unsigned int channel, return 0; } - +EXPORT_SYMBOL(scsi_scan_host_selected); static void scsi_sysfs_add_devices(struct Scsi_Host *shost) { struct scsi_device *sdev; @@ -1714,15 +1942,16 @@ static void scsi_sysfs_add_devices(struct Scsi_Host *shost) */ static struct async_scan_data *scsi_prep_async_scan(struct Scsi_Host *shost) { - struct async_scan_data *data; + struct async_scan_data *data = NULL; unsigned long flags; if (strncmp(scsi_scan_type, "sync", 4) == 0) return NULL; + mutex_lock(&shost->scan_mutex); if (shost->async_scan) { shost_printk(KERN_DEBUG, shost, "%s called twice\n", __func__); - return NULL; + goto err; } data = kmalloc(sizeof(*data), GFP_KERNEL); @@ -1733,7 +1962,6 @@ static struct async_scan_data *scsi_prep_async_scan(struct Scsi_Host *shost) goto err; init_completion(&data->prev_finished); - mutex_lock(&shost->scan_mutex); spin_lock_irqsave(shost->host_lock, flags); shost->async_scan = 1; spin_unlock_irqrestore(shost->host_lock, flags); @@ -1748,6 +1976,7 @@ static struct async_scan_data *scsi_prep_async_scan(struct Scsi_Host *shost) return data; err: + mutex_unlock(&shost->scan_mutex); kfree(data); return NULL; } @@ -1814,7 +2043,7 @@ static void do_scsi_scan_host(struct Scsi_Host *shost) msleep(10); } else { scsi_scan_host_selected(shost, SCAN_WILD_CARD, SCAN_WILD_CARD, - SCAN_WILD_CARD, 0); + SCAN_WILD_CARD, SCSI_SCAN_INITIAL); } } @@ -1830,6 +2059,8 @@ static void do_scan_async(void *_data, async_cookie_t c) /** * scsi_scan_host - scan the given adapter * @shost: adapter to scan + * + * Notes: Should be called after scsi_add_host() **/ void scsi_scan_host(struct Scsi_Host *shost) { @@ -1865,69 +2096,65 @@ void scsi_forget_host(struct Scsi_Host *shost) restart: spin_lock_irqsave(shost->host_lock, flags); list_for_each_entry(sdev, &shost->__devices, siblings) { - if (sdev->sdev_state == SDEV_DEL) + if (scsi_device_is_pseudo_dev(sdev) || + sdev->sdev_state == SDEV_DEL) continue; spin_unlock_irqrestore(shost->host_lock, flags); __scsi_remove_device(sdev); goto restart; } spin_unlock_irqrestore(shost->host_lock, flags); + + /* + * Remove the pseudo device last since it may be needed during removal + * of other SCSI devices. + */ + if (shost->pseudo_sdev) + __scsi_remove_device(shost->pseudo_sdev); } /** - * scsi_get_host_dev - Create a scsi_device that points to the host adapter itself - * @shost: Host that needs a scsi_device + * scsi_get_pseudo_sdev() - Attach a pseudo SCSI device to a SCSI host + * @shost: Host that needs a pseudo SCSI device * * Lock status: None assumed. * * Returns: The scsi_device or NULL * * Notes: - * Attach a single scsi_device to the Scsi_Host - this should - * be made to look like a "pseudo-device" that points to the - * HA itself. - * - * Note - this device is not accessible from any high-level - * drivers (including generics), which is probably not - * optimal. We can add hooks later to attach. + * Attach a single scsi_device to the Scsi_Host. The primary aim for this + * device is to serve as a container from which SCSI commands can be + * allocated. Each SCSI command will carry a command tag allocated by the + * block layer. These SCSI commands can be used by the LLDD to send + * internal or passthrough commands without having to manage tag allocation + * inside the LLDD. */ -struct scsi_device *scsi_get_host_dev(struct Scsi_Host *shost) +struct scsi_device *scsi_get_pseudo_sdev(struct Scsi_Host *shost) { struct scsi_device *sdev = NULL; struct scsi_target *starget; - mutex_lock(&shost->scan_mutex); + guard(mutex)(&shost->scan_mutex); + if (!scsi_host_scan_allowed(shost)) goto out; - starget = scsi_alloc_target(&shost->shost_gendev, 0, shost->this_id); + + starget = scsi_alloc_target(&shost->shost_gendev, 0, shost->max_id); if (!starget) goto out; - sdev = scsi_alloc_sdev(starget, 0, NULL); - if (sdev) - sdev->borken = 0; - else + sdev = scsi_alloc_sdev(starget, U64_MAX, NULL); + if (!sdev) { scsi_target_reap(starget); - put_device(&starget->dev); - out: - mutex_unlock(&shost->scan_mutex); - return sdev; -} -EXPORT_SYMBOL(scsi_get_host_dev); + goto put_target; + } -/** - * scsi_free_host_dev - Free a scsi_device that points to the host adapter itself - * @sdev: Host device to be freed - * - * Lock status: None assumed. - * - * Returns: Nothing - */ -void scsi_free_host_dev(struct scsi_device *sdev) -{ - BUG_ON(sdev->id != sdev->host->this_id); + sdev->borken = 0; - __scsi_remove_device(sdev); -} -EXPORT_SYMBOL(scsi_free_host_dev); +put_target: + /* See also the get_device(dev) call in scsi_alloc_target(). */ + put_device(&starget->dev); +out: + return sdev; +} |