diff options
Diffstat (limited to 'drivers/scsi/scsi_lib.c')
| -rw-r--r-- | drivers/scsi/scsi_lib.c | 2417 |
1 files changed, 1463 insertions, 954 deletions
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 3ff53880978..3f50dfcb322 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -8,141 +8,90 @@ */ #include <linux/bio.h> +#include <linux/bitops.h> #include <linux/blkdev.h> #include <linux/completion.h> #include <linux/kernel.h> +#include <linux/export.h> #include <linux/mempool.h> #include <linux/slab.h> #include <linux/init.h> #include <linux/pci.h> #include <linux/delay.h> +#include <linux/hardirq.h> +#include <linux/scatterlist.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_request.h> #include "scsi_priv.h" #include "scsi_logging.h" -#define SG_MEMPOOL_NR (sizeof(scsi_sg_pools)/sizeof(struct scsi_host_sg_pool)) -#define SG_MEMPOOL_SIZE 32 +#define SG_MEMPOOL_NR ARRAY_SIZE(scsi_sg_pools) +#define SG_MEMPOOL_SIZE 2 struct scsi_host_sg_pool { size_t size; - char *name; - kmem_cache_t *slab; + char *name; + struct kmem_cache *slab; mempool_t *pool; }; -#if (SCSI_MAX_PHYS_SEGMENTS < 32) -#error SCSI_MAX_PHYS_SEGMENTS is too small +#define SP(x) { x, "sgpool-" __stringify(x) } +#if (SCSI_MAX_SG_SEGMENTS < 32) +#error SCSI_MAX_SG_SEGMENTS is too small (must be 32 or greater) #endif - -#define SP(x) { x, "sgpool-" #x } static struct scsi_host_sg_pool scsi_sg_pools[] = { SP(8), SP(16), +#if (SCSI_MAX_SG_SEGMENTS > 32) SP(32), -#if (SCSI_MAX_PHYS_SEGMENTS > 32) +#if (SCSI_MAX_SG_SEGMENTS > 64) SP(64), -#if (SCSI_MAX_PHYS_SEGMENTS > 64) +#if (SCSI_MAX_SG_SEGMENTS > 128) SP(128), -#if (SCSI_MAX_PHYS_SEGMENTS > 128) - SP(256), -#if (SCSI_MAX_PHYS_SEGMENTS > 256) -#error SCSI_MAX_PHYS_SEGMENTS is too large +#if (SCSI_MAX_SG_SEGMENTS > 256) +#error SCSI_MAX_SG_SEGMENTS is too large (256 MAX) #endif #endif #endif #endif -}; + SP(SCSI_MAX_SG_SEGMENTS) +}; #undef SP +struct kmem_cache *scsi_sdb_cache; /* - * Function: scsi_insert_special_req() - * - * Purpose: Insert pre-formed request into request queue. - * - * Arguments: sreq - request that is ready to be queued. - * at_head - boolean. True if we should insert at head - * of queue, false if we should insert at tail. - * - * Lock status: Assumed that lock is not held upon entry. - * - * Returns: Nothing - * - * Notes: This function is called from character device and from - * ioctl types of functions where the caller knows exactly - * what SCSI command needs to be issued. The idea is that - * we merely inject the command into the queue (at the head - * for now), and then call the queue request function to actually - * process it. + * When to reinvoke queueing after a resource shortage. It's 3 msecs to + * not change behaviour from the previous unplug mechanism, experimentation + * may prove this needs changing. */ -int scsi_insert_special_req(struct scsi_request *sreq, int at_head) -{ - /* - * Because users of this function are apt to reuse requests with no - * modification, we have to sanitise the request flags here - */ - sreq->sr_request->flags &= ~REQ_DONTPREP; - blk_insert_request(sreq->sr_device->request_queue, sreq->sr_request, - at_head, sreq); - return 0; -} - -static void scsi_run_queue(struct request_queue *q); - -/* - * Function: scsi_unprep_request() - * - * Purpose: Remove all preparation done for a request, including its - * associated scsi_cmnd, so that it can be requeued. - * - * Arguments: req - request to unprepare - * - * Lock status: Assumed that no locks are held upon entry. - * - * Returns: Nothing. - */ -static void scsi_unprep_request(struct request *req) -{ - struct scsi_cmnd *cmd = req->special; - - req->flags &= ~REQ_DONTPREP; - req->special = (req->flags & REQ_SPECIAL) ? cmd->sc_request : NULL; +#define SCSI_QUEUE_DELAY 3 - scsi_put_command(cmd); -} - -/* - * Function: scsi_queue_insert() - * - * Purpose: Insert a command in the midlevel queue. - * - * Arguments: cmd - command that we are adding to queue. - * reason - why we are inserting command to queue. - * - * Lock status: Assumed that lock is not held upon entry. - * - * Returns: Nothing. - * - * Notes: We do this for one of two cases. Either the host is busy - * and it cannot accept any more commands for the time being, - * or the device returned QUEUE_FULL and can accept no more - * commands. - * Notes: This could be called either from an interrupt context or a - * normal process context. +/** + * __scsi_queue_insert - private queue insertion + * @cmd: The SCSI command being requeued + * @reason: The reason for the requeue + * @unbusy: Whether the queue should be unbusied + * + * This is a private queue insertion. The public interface + * scsi_queue_insert() always assumes the queue should be unbusied + * because it's always called before the completion. This function is + * for a requeue after completion, which should only occur in this + * file. */ -int scsi_queue_insert(struct scsi_cmnd *cmd, int reason) +static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, int unbusy) { struct Scsi_Host *host = cmd->device->host; struct scsi_device *device = cmd->device; + struct scsi_target *starget = scsi_target(device); struct request_queue *q = device->request_queue; unsigned long flags; @@ -162,147 +111,62 @@ int scsi_queue_insert(struct scsi_cmnd *cmd, int reason) * if a command is requeued with no other commands outstanding * either for the device or for the host. */ - if (reason == SCSI_MLQUEUE_HOST_BUSY) + switch (reason) { + case SCSI_MLQUEUE_HOST_BUSY: host->host_blocked = host->max_host_blocked; - else if (reason == SCSI_MLQUEUE_DEVICE_BUSY) + break; + case SCSI_MLQUEUE_DEVICE_BUSY: + case SCSI_MLQUEUE_EH_RETRY: device->device_blocked = device->max_device_blocked; + break; + case SCSI_MLQUEUE_TARGET_BUSY: + starget->target_blocked = starget->max_target_blocked; + break; + } /* * Decrement the counters, since these commands are no longer * active on the host/device. */ - scsi_device_unbusy(device); + if (unbusy) + scsi_device_unbusy(device); /* * Requeue this command. It will go before all other commands - * that are already in the queue. - * - * NOTE: there is magic here about the way the queue is plugged if - * we have no outstanding commands. - * - * Although we *don't* plug the queue, we call the request - * function. The SCSI request function detects the blocked condition - * and plugs the queue appropriately. - */ + * that are already in the queue. Schedule requeue work under + * lock such that the kblockd_schedule_work() call happens + * before blk_cleanup_queue() finishes. + */ + cmd->result = 0; spin_lock_irqsave(q->queue_lock, flags); blk_requeue_request(q, cmd->request); + kblockd_schedule_work(&device->requeue_work); spin_unlock_irqrestore(q->queue_lock, flags); - - scsi_run_queue(q); - - return 0; } /* - * Function: scsi_do_req + * Function: scsi_queue_insert() * - * Purpose: Queue a SCSI request + * Purpose: Insert a command in the midlevel queue. * - * Arguments: sreq - command descriptor. - * cmnd - actual SCSI command to be performed. - * buffer - data buffer. - * bufflen - size of data buffer. - * done - completion function to be run. - * timeout - how long to let it run before timeout. - * retries - number of retries we allow. + * Arguments: cmd - command that we are adding to queue. + * reason - why we are inserting command to queue. * - * Lock status: No locks held upon entry. + * Lock status: Assumed that lock is not held upon entry. * * Returns: Nothing. * - * Notes: This function is only used for queueing requests for things - * like ioctls and character device requests - this is because - * we essentially just inject a request into the queue for the - * device. - * - * In order to support the scsi_device_quiesce function, we - * now inject requests on the *head* of the device queue - * rather than the tail. + * Notes: We do this for one of two cases. Either the host is busy + * and it cannot accept any more commands for the time being, + * or the device returned QUEUE_FULL and can accept no more + * commands. + * Notes: This could be called either from an interrupt context or a + * normal process context. */ -void scsi_do_req(struct scsi_request *sreq, const void *cmnd, - void *buffer, unsigned bufflen, - void (*done)(struct scsi_cmnd *), - int timeout, int retries) -{ - /* - * If the upper level driver is reusing these things, then - * we should release the low-level block now. Another one will - * be allocated later when this request is getting queued. - */ - __scsi_release_request(sreq); - - /* - * Our own function scsi_done (which marks the host as not busy, - * disables the timeout counter, etc) will be called by us or by the - * scsi_hosts[host].queuecommand() function needs to also call - * the completion function for the high level driver. - */ - memcpy(sreq->sr_cmnd, cmnd, sizeof(sreq->sr_cmnd)); - sreq->sr_bufflen = bufflen; - sreq->sr_buffer = buffer; - sreq->sr_allowed = retries; - sreq->sr_done = done; - sreq->sr_timeout_per_command = timeout; - - if (sreq->sr_cmd_len == 0) - sreq->sr_cmd_len = COMMAND_SIZE(sreq->sr_cmnd[0]); - - /* - * head injection *required* here otherwise quiesce won't work - */ - scsi_insert_special_req(sreq, 1); -} -EXPORT_SYMBOL(scsi_do_req); - -/* This is the end routine we get to if a command was never attached - * to the request. Simply complete the request without changing - * rq_status; this will cause a DRIVER_ERROR. */ -static void scsi_wait_req_end_io(struct request *req) -{ - BUG_ON(!req->waiting); - - complete(req->waiting); -} - -void scsi_wait_req(struct scsi_request *sreq, const void *cmnd, void *buffer, - unsigned bufflen, int timeout, int retries) +void scsi_queue_insert(struct scsi_cmnd *cmd, int reason) { - DECLARE_COMPLETION(wait); - int write = (sreq->sr_data_direction == DMA_TO_DEVICE); - struct request *req; - - req = blk_get_request(sreq->sr_device->request_queue, write, - __GFP_WAIT); - if (bufflen && blk_rq_map_kern(sreq->sr_device->request_queue, req, - buffer, bufflen, __GFP_WAIT)) { - sreq->sr_result = DRIVER_ERROR << 24; - blk_put_request(req); - return; - } - - req->flags |= REQ_NOMERGE; - req->waiting = &wait; - req->end_io = scsi_wait_req_end_io; - req->cmd_len = COMMAND_SIZE(((u8 *)cmnd)[0]); - req->sense = sreq->sr_sense_buffer; - req->sense_len = 0; - memcpy(req->cmd, cmnd, req->cmd_len); - req->timeout = timeout; - req->flags |= REQ_BLOCK_PC; - req->rq_disk = NULL; - blk_insert_request(sreq->sr_device->request_queue, req, - sreq->sr_data_direction == DMA_TO_DEVICE, NULL); - wait_for_completion(&wait); - sreq->sr_request->waiting = NULL; - sreq->sr_result = req->errors; - if (req->errors) - sreq->sr_result |= (DRIVER_ERROR << 24); - - blk_put_request(req); + __scsi_queue_insert(cmd, reason, 1); } - -EXPORT_SYMBOL(scsi_wait_req); - /** * scsi_execute - insert request and wait for the result * @sdev: scsi device @@ -314,19 +178,24 @@ EXPORT_SYMBOL(scsi_wait_req); * @timeout: request timeout in seconds * @retries: number of times to retry request * @flags: or into request flags; + * @resid: optional residual length * - * returns the req->errors value which is the the scsi_cmnd result + * returns the req->errors value which is the scsi_cmnd result * field. - **/ + */ int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd, int data_direction, void *buffer, unsigned bufflen, - unsigned char *sense, int timeout, int retries, int flags) + unsigned char *sense, int timeout, int retries, u64 flags, + int *resid) { struct request *req; int write = (data_direction == DMA_TO_DEVICE); int ret = DRIVER_ERROR << 24; req = blk_get_request(sdev->request_queue, write, __GFP_WAIT); + if (!req) + return ret; + blk_rq_set_block_pc(req); if (bufflen && blk_rq_map_kern(sdev->request_queue, req, buffer, bufflen, __GFP_WAIT)) @@ -336,14 +205,26 @@ int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd, memcpy(req->cmd, cmd, req->cmd_len); req->sense = sense; req->sense_len = 0; + req->retries = retries; req->timeout = timeout; - req->flags |= flags | REQ_BLOCK_PC | REQ_SPECIAL | REQ_QUIET; + req->cmd_flags |= flags | REQ_QUIET | REQ_PREEMPT; /* * head injection *required* here otherwise quiesce won't work */ blk_execute_rq(req->q, NULL, req, 1); + /* + * Some devices (USB mass-storage in particular) may transfer + * garbage data together with a residue indicating that the data + * is invalid. Prevent the garbage from being misinterpreted + * and prevent security leaks by zeroing out the excess data. + */ + if (unlikely(req->resid_len > 0 && req->resid_len <= bufflen)) + memset(buffer + (bufflen - req->resid_len), 0, req->resid_len); + + if (resid) + *resid = req->resid_len; ret = req->errors; out: blk_put_request(req); @@ -352,29 +233,28 @@ int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd, } EXPORT_SYMBOL(scsi_execute); - -int scsi_execute_req(struct scsi_device *sdev, const unsigned char *cmd, +int scsi_execute_req_flags(struct scsi_device *sdev, const unsigned char *cmd, int data_direction, void *buffer, unsigned bufflen, - struct scsi_sense_hdr *sshdr, int timeout, int retries) + struct scsi_sense_hdr *sshdr, int timeout, int retries, + int *resid, u64 flags) { char *sense = NULL; int result; if (sshdr) { - sense = kmalloc(SCSI_SENSE_BUFFERSIZE, GFP_NOIO); + sense = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_NOIO); if (!sense) return DRIVER_ERROR << 24; - memset(sense, 0, SCSI_SENSE_BUFFERSIZE); } result = scsi_execute(sdev, cmd, data_direction, buffer, bufflen, - sense, timeout, retries, 0); + sense, timeout, retries, flags, resid); if (sshdr) scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, sshdr); kfree(sense); return result; } -EXPORT_SYMBOL(scsi_execute_req); +EXPORT_SYMBOL(scsi_execute_req_flags); /* * Function: scsi_init_cmd_errh() @@ -383,71 +263,30 @@ EXPORT_SYMBOL(scsi_execute_req); * * Arguments: cmd - command that is ready to be queued. * - * Returns: Nothing - * * Notes: This function has the job of initializing a number of * fields related to error handling. Typically this will * be called once for each command, as required. */ -static int scsi_init_cmd_errh(struct scsi_cmnd *cmd) +static void scsi_init_cmd_errh(struct scsi_cmnd *cmd) { cmd->serial_number = 0; - - memset(cmd->sense_buffer, 0, sizeof cmd->sense_buffer); - + scsi_set_resid(cmd, 0); + memset(cmd->sense_buffer, 0, SCSI_SENSE_BUFFERSIZE); if (cmd->cmd_len == 0) - cmd->cmd_len = COMMAND_SIZE(cmd->cmnd[0]); - - /* - * We need saved copies of a number of fields - this is because - * error handling may need to overwrite these with different values - * to run different commands, and once error handling is complete, - * we will need to restore these values prior to running the actual - * command. - */ - cmd->old_use_sg = cmd->use_sg; - cmd->old_cmd_len = cmd->cmd_len; - cmd->sc_old_data_direction = cmd->sc_data_direction; - cmd->old_underflow = cmd->underflow; - memcpy(cmd->data_cmnd, cmd->cmnd, sizeof(cmd->cmnd)); - cmd->buffer = cmd->request_buffer; - cmd->bufflen = cmd->request_bufflen; - - return 1; -} - -/* - * Function: scsi_setup_cmd_retry() - * - * Purpose: Restore the command state for a retry - * - * Arguments: cmd - command to be restored - * - * Returns: Nothing - * - * Notes: Immediately prior to retrying a command, we need - * to restore certain fields that we saved above. - */ -void scsi_setup_cmd_retry(struct scsi_cmnd *cmd) -{ - memcpy(cmd->cmnd, cmd->data_cmnd, sizeof(cmd->data_cmnd)); - cmd->request_buffer = cmd->buffer; - cmd->request_bufflen = cmd->bufflen; - cmd->use_sg = cmd->old_use_sg; - cmd->cmd_len = cmd->old_cmd_len; - cmd->sc_data_direction = cmd->sc_old_data_direction; - cmd->underflow = cmd->old_underflow; + cmd->cmd_len = scsi_command_size(cmd->cmnd); } void scsi_device_unbusy(struct scsi_device *sdev) { struct Scsi_Host *shost = sdev->host; + struct scsi_target *starget = scsi_target(sdev); unsigned long flags; spin_lock_irqsave(shost->host_lock, flags); shost->host_busy--; + starget->target_busy--; if (unlikely(scsi_host_in_recovery(shost) && - shost->host_failed)) + (shost->host_failed || shost->host_eh_scheduled))) scsi_eh_wakeup(shost); spin_unlock(shost->host_lock); spin_lock(sdev->request_queue->queue_lock); @@ -501,32 +340,42 @@ static void scsi_single_lun_run(struct scsi_device *current_sdev) spin_unlock_irqrestore(shost->host_lock, flags); } -/* - * Function: scsi_run_queue() - * - * Purpose: Select a proper request queue to serve next - * - * Arguments: q - last request's queue - * - * Returns: Nothing - * - * Notes: The previous command was completely finished, start - * a new one if possible. - */ -static void scsi_run_queue(struct request_queue *q) +static inline int scsi_device_is_busy(struct scsi_device *sdev) { - struct scsi_device *sdev = q->queuedata; - struct Scsi_Host *shost = sdev->host; - unsigned long flags; + if (sdev->device_busy >= sdev->queue_depth || sdev->device_blocked) + return 1; - if (sdev->single_lun) - scsi_single_lun_run(sdev); + return 0; +} + +static inline int scsi_target_is_busy(struct scsi_target *starget) +{ + return ((starget->can_queue > 0 && + starget->target_busy >= starget->can_queue) || + starget->target_blocked); +} + +static inline int scsi_host_is_busy(struct Scsi_Host *shost) +{ + if ((shost->can_queue > 0 && shost->host_busy >= shost->can_queue) || + shost->host_blocked || shost->host_self_blocked) + return 1; + + return 0; +} + +static void scsi_starved_list_run(struct Scsi_Host *shost) +{ + LIST_HEAD(starved_list); + struct scsi_device *sdev; + unsigned long flags; spin_lock_irqsave(shost->host_lock, flags); - while (!list_empty(&shost->starved_list) && - !shost->host_blocked && !shost->host_self_blocked && - !((shost->can_queue > 0) && - (shost->host_busy >= shost->can_queue))) { + list_splice_init(&shost->starved_list, &starved_list); + + while (!list_empty(&starved_list)) { + struct request_queue *slq; + /* * As long as shost is accepting commands and we have * starved queues, call blk_run_queue. scsi_request_fn @@ -537,27 +386,77 @@ static void scsi_run_queue(struct request_queue *q) * scsi_request_fn must get the host_lock before checking * or modifying starved_list or starved_entry. */ - sdev = list_entry(shost->starved_list.next, - struct scsi_device, starved_entry); + if (scsi_host_is_busy(shost)) + break; + + sdev = list_entry(starved_list.next, + struct scsi_device, starved_entry); list_del_init(&sdev->starved_entry); + if (scsi_target_is_busy(scsi_target(sdev))) { + list_move_tail(&sdev->starved_entry, + &shost->starved_list); + continue; + } + + /* + * Once we drop the host lock, a racing scsi_remove_device() + * call may remove the sdev from the starved list and destroy + * it and the queue. Mitigate by taking a reference to the + * queue and never touching the sdev again after we drop the + * host lock. Note: if __scsi_remove_device() invokes + * blk_cleanup_queue() before the queue is run from this + * function then blk_run_queue() will return immediately since + * blk_cleanup_queue() marks the queue with QUEUE_FLAG_DYING. + */ + slq = sdev->request_queue; + if (!blk_get_queue(slq)) + continue; spin_unlock_irqrestore(shost->host_lock, flags); - blk_run_queue(sdev->request_queue); + blk_run_queue(slq); + blk_put_queue(slq); spin_lock_irqsave(shost->host_lock, flags); - if (unlikely(!list_empty(&sdev->starved_entry))) - /* - * sdev lost a race, and was put back on the - * starved list. This is unlikely but without this - * in theory we could loop forever. - */ - break; } + /* put any unprocessed entries back */ + list_splice(&starved_list, &shost->starved_list); spin_unlock_irqrestore(shost->host_lock, flags); +} + +/* + * Function: scsi_run_queue() + * + * Purpose: Select a proper request queue to serve next + * + * Arguments: q - last request's queue + * + * Returns: Nothing + * + * Notes: The previous command was completely finished, start + * a new one if possible. + */ +static void scsi_run_queue(struct request_queue *q) +{ + struct scsi_device *sdev = q->queuedata; + + if (scsi_target(sdev)->single_lun) + scsi_single_lun_run(sdev); + if (!list_empty(&sdev->host->starved_list)) + scsi_starved_list_run(sdev->host); blk_run_queue(q); } +void scsi_requeue_run_queue(struct work_struct *work) +{ + struct scsi_device *sdev; + struct request_queue *q; + + sdev = container_of(work, struct scsi_device, requeue_work); + q = sdev->request_queue; + scsi_run_queue(q); +} + /* * Function: scsi_requeue_command() * @@ -578,23 +477,31 @@ static void scsi_run_queue(struct request_queue *q) */ static void scsi_requeue_command(struct request_queue *q, struct scsi_cmnd *cmd) { + struct scsi_device *sdev = cmd->device; struct request *req = cmd->request; unsigned long flags; - scsi_unprep_request(req); spin_lock_irqsave(q->queue_lock, flags); + blk_unprep_request(req); + req->special = NULL; + scsi_put_command(cmd); blk_requeue_request(q, req); spin_unlock_irqrestore(q->queue_lock, flags); scsi_run_queue(q); + + put_device(&sdev->sdev_gendev); } void scsi_next_command(struct scsi_cmnd *cmd) { - struct request_queue *q = cmd->device->request_queue; + struct scsi_device *sdev = cmd->device; + struct request_queue *q = sdev->request_queue; scsi_put_command(cmd); scsi_run_queue(q); + + put_device(&sdev->sdev_gendev); } void scsi_run_host_queues(struct Scsi_Host *shost) @@ -605,133 +512,61 @@ void scsi_run_host_queues(struct Scsi_Host *shost) scsi_run_queue(sdev->request_queue); } -/* - * Function: scsi_end_request() - * - * Purpose: Post-processing of completed commands (usually invoked at end - * of upper level post-processing and scsi_io_completion). - * - * Arguments: cmd - command that is complete. - * uptodate - 1 if I/O indicates success, <= 0 for I/O error. - * bytes - number of bytes of completed I/O - * requeue - indicates whether we should requeue leftovers. - * - * Lock status: Assumed that lock is not held upon entry. - * - * Returns: cmd if requeue required, NULL otherwise. - * - * Notes: This is called for block device requests in order to - * mark some number of sectors as complete. - * - * We are guaranteeing that the request queue will be goosed - * at some point during this call. - * Notes: If cmd was requeued, upon return it will be a stale pointer. - */ -static struct scsi_cmnd *scsi_end_request(struct scsi_cmnd *cmd, int uptodate, - int bytes, int requeue) +static inline unsigned int scsi_sgtable_index(unsigned short nents) { - request_queue_t *q = cmd->device->request_queue; - struct request *req = cmd->request; - unsigned long flags; + unsigned int index; - /* - * If there are blocks left over at the end, set up the command - * to queue the remainder of them. - */ - if (end_that_request_chunk(req, uptodate, bytes)) { - int leftover = (req->hard_nr_sectors << 9); + BUG_ON(nents > SCSI_MAX_SG_SEGMENTS); - if (blk_pc_request(req)) - leftover = req->data_len; - - /* kill remainder if no retrys */ - if (!uptodate && blk_noretry_request(req)) - end_that_request_chunk(req, 0, leftover); - else { - if (requeue) { - /* - * Bleah. Leftovers again. Stick the - * leftovers in the front of the - * queue, and goose the queue again. - */ - scsi_requeue_command(q, cmd); - cmd = NULL; - } - return cmd; - } - } - - add_disk_randomness(req->rq_disk); - - spin_lock_irqsave(q->queue_lock, flags); - if (blk_rq_tagged(req)) - blk_queue_end_tag(q, req); - end_that_request_last(req); - spin_unlock_irqrestore(q->queue_lock, flags); + if (nents <= 8) + index = 0; + else + index = get_count_order(nents) - 3; - /* - * This will goose the queue request function at the end, so we don't - * need to worry about launching another command. - */ - scsi_next_command(cmd); - return NULL; + return index; } -static struct scatterlist *scsi_alloc_sgtable(struct scsi_cmnd *cmd, gfp_t gfp_mask) +static void scsi_sg_free(struct scatterlist *sgl, unsigned int nents) { struct scsi_host_sg_pool *sgp; - struct scatterlist *sgl; - BUG_ON(!cmd->use_sg); + sgp = scsi_sg_pools + scsi_sgtable_index(nents); + mempool_free(sgl, sgp->pool); +} - switch (cmd->use_sg) { - case 1 ... 8: - cmd->sglist_len = 0; - break; - case 9 ... 16: - cmd->sglist_len = 1; - break; - case 17 ... 32: - cmd->sglist_len = 2; - break; -#if (SCSI_MAX_PHYS_SEGMENTS > 32) - case 33 ... 64: - cmd->sglist_len = 3; - break; -#if (SCSI_MAX_PHYS_SEGMENTS > 64) - case 65 ... 128: - cmd->sglist_len = 4; - break; -#if (SCSI_MAX_PHYS_SEGMENTS > 128) - case 129 ... 256: - cmd->sglist_len = 5; - break; -#endif -#endif -#endif - default: - return NULL; - } +static struct scatterlist *scsi_sg_alloc(unsigned int nents, gfp_t gfp_mask) +{ + struct scsi_host_sg_pool *sgp; - sgp = scsi_sg_pools + cmd->sglist_len; - sgl = mempool_alloc(sgp->pool, gfp_mask); - return sgl; + sgp = scsi_sg_pools + scsi_sgtable_index(nents); + return mempool_alloc(sgp->pool, gfp_mask); } -static void scsi_free_sgtable(struct scatterlist *sgl, int index) +static int scsi_alloc_sgtable(struct scsi_data_buffer *sdb, int nents, + gfp_t gfp_mask) { - struct scsi_host_sg_pool *sgp; + int ret; - BUG_ON(index >= SG_MEMPOOL_NR); + BUG_ON(!nents); - sgp = scsi_sg_pools + index; - mempool_free(sgl, sgp->pool); + ret = __sg_alloc_table(&sdb->table, nents, SCSI_MAX_SG_SEGMENTS, + gfp_mask, scsi_sg_alloc); + if (unlikely(ret)) + __sg_free_table(&sdb->table, SCSI_MAX_SG_SEGMENTS, + scsi_sg_free); + + return ret; +} + +static void scsi_free_sgtable(struct scsi_data_buffer *sdb) +{ + __sg_free_table(&sdb->table, SCSI_MAX_SG_SEGMENTS, scsi_sg_free); } /* * Function: scsi_release_buffers() * - * Purpose: Completion processing for block device I/O requests. + * Purpose: Free resources allocate for a scsi_command. * * Arguments: cmd - command that we are bailing. * @@ -742,29 +577,73 @@ static void scsi_free_sgtable(struct scatterlist *sgl, int index) * Notes: In the event that an upper level driver rejects a * command, we must release resources allocated during * the __init_io() function. Primarily this would involve - * the scatter-gather table, and potentially any bounce - * buffers. + * the scatter-gather table. */ -static void scsi_release_buffers(struct scsi_cmnd *cmd) +void scsi_release_buffers(struct scsi_cmnd *cmd) { - struct request *req = cmd->request; + if (cmd->sdb.table.nents) + scsi_free_sgtable(&cmd->sdb); - /* - * Free up any indirection buffers we allocated for DMA purposes. - */ - if (cmd->use_sg) - scsi_free_sgtable(cmd->request_buffer, cmd->sglist_len); - else if (cmd->request_buffer != req->buffer) - kfree(cmd->request_buffer); + memset(&cmd->sdb, 0, sizeof(cmd->sdb)); - /* - * Zero these out. They now point to freed memory, and it is - * dangerous to hang onto the pointers. - */ - cmd->buffer = NULL; - cmd->bufflen = 0; - cmd->request_buffer = NULL; - cmd->request_bufflen = 0; + if (scsi_prot_sg_count(cmd)) + scsi_free_sgtable(cmd->prot_sdb); +} +EXPORT_SYMBOL(scsi_release_buffers); + +static void scsi_release_bidi_buffers(struct scsi_cmnd *cmd) +{ + struct scsi_data_buffer *bidi_sdb = cmd->request->next_rq->special; + + scsi_free_sgtable(bidi_sdb); + kmem_cache_free(scsi_sdb_cache, bidi_sdb); + cmd->request->next_rq->special = NULL; +} + +/** + * __scsi_error_from_host_byte - translate SCSI error code into errno + * @cmd: SCSI command (unused) + * @result: scsi error code + * + * Translate SCSI error code into standard UNIX errno. + * Return values: + * -ENOLINK temporary transport failure + * -EREMOTEIO permanent target failure, do not retry + * -EBADE permanent nexus failure, retry on other path + * -ENOSPC No write space available + * -ENODATA Medium error + * -EIO unspecified I/O error + */ +static int __scsi_error_from_host_byte(struct scsi_cmnd *cmd, int result) +{ + int error = 0; + + switch(host_byte(result)) { + case DID_TRANSPORT_FAILFAST: + error = -ENOLINK; + break; + case DID_TARGET_FAILURE: + set_host_byte(cmd, DID_OK); + error = -EREMOTEIO; + break; + case DID_NEXUS_FAILURE: + set_host_byte(cmd, DID_OK); + error = -EBADE; + break; + case DID_ALLOC_FAILURE: + set_host_byte(cmd, DID_OK); + error = -ENOSPC; + break; + case DID_MEDIUM_ERROR: + set_host_byte(cmd, DID_OK); + error = -ENODATA; + break; + default: + error = -EIO; + break; + } + + return error; } /* @@ -778,64 +657,46 @@ static void scsi_release_buffers(struct scsi_cmnd *cmd) * * Returns: Nothing * - * Notes: This function is matched in terms of capabilities to - * the function that created the scatter-gather list. - * In other words, if there are no bounce buffers - * (the normal case for most drivers), we don't need - * the logic to deal with cleaning up afterwards. + * Notes: We will finish off the specified number of sectors. If we + * are done, the command block will be released and the queue + * function will be goosed. If we are not done then we have to + * figure out what to do next: * - * We must do one of several things here: + * a) We can call scsi_requeue_command(). The request + * will be unprepared and put back on the queue. Then + * a new command will be created for it. This should + * be used if we made forward progress, or if we want + * to switch from READ(10) to READ(6) for example. * - * a) Call scsi_end_request. This will finish off the - * specified number of sectors. If we are done, the - * command block will be released, and the queue - * function will be goosed. If we are not done, then - * scsi_end_request will directly goose the queue. + * b) We can call __scsi_queue_insert(). The request will + * be put back on the queue and retried using the same + * command as before, possibly after a delay. * - * b) We can just use scsi_requeue_command() here. This would - * be used if we just wanted to retry, for example. + * c) We can call blk_end_request() with -EIO to fail + * the remainder of the request. */ -void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes, - unsigned int block_bytes) +void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) { int result = cmd->result; - int this_count = cmd->bufflen; - request_queue_t *q = cmd->device->request_queue; + struct request_queue *q = cmd->device->request_queue; struct request *req = cmd->request; - int clear_errors = 1; + int error = 0; struct scsi_sense_hdr sshdr; int sense_valid = 0; int sense_deferred = 0; - - if (blk_complete_barrier_rq(q, req, good_bytes >> 9)) - return; - - /* - * Free up any indirection buffers we allocated for DMA purposes. - * For the case of a READ, we need to copy the data out of the - * bounce buffer and into the real buffer. - */ - if (cmd->use_sg) - scsi_free_sgtable(cmd->buffer, cmd->sglist_len); - else if (cmd->buffer != req->buffer) { - if (rq_data_dir(req) == READ) { - unsigned long flags; - char *to = bio_kmap_irq(req->bio, &flags); - memcpy(to, cmd->buffer, cmd->bufflen); - bio_kunmap_irq(to, &flags); - } - kfree(cmd->buffer); - } + enum {ACTION_FAIL, ACTION_REPREP, ACTION_RETRY, + ACTION_DELAYED_RETRY} action; + char *description = NULL; + unsigned long wait_for = (cmd->allowed + 1) * req->timeout; if (result) { sense_valid = scsi_command_normalize_sense(cmd, &sshdr); if (sense_valid) sense_deferred = scsi_sense_is_deferred(&sshdr); } - if (blk_pc_request(req)) { /* SG_IO ioctl from block level */ - req->errors = result; + + if (req->cmd_type == REQ_TYPE_BLOCK_PC) { /* SG_IO ioctl from block level */ if (result) { - clear_errors = 0; if (sense_valid && req->sense) { /* * SG_IO wants current and deferred errors @@ -847,158 +708,278 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes, memcpy(req->sense, cmd->sense_buffer, len); req->sense_len = len; } - } else - req->data_len = cmd->resid; + if (!sense_deferred) + error = __scsi_error_from_host_byte(cmd, result); + } + /* + * __scsi_error_from_host_byte may have reset the host_byte + */ + req->errors = cmd->result; + + req->resid_len = scsi_get_resid(cmd); + + if (scsi_bidi_cmnd(cmd)) { + /* + * Bidi commands Must be complete as a whole, + * both sides at once. + */ + req->next_rq->resid_len = scsi_in(cmd)->resid; + + scsi_release_buffers(cmd); + scsi_release_bidi_buffers(cmd); + + blk_end_request_all(req, 0); + + scsi_next_command(cmd); + return; + } + } else if (blk_rq_bytes(req) == 0 && result && !sense_deferred) { + /* + * Certain non BLOCK_PC requests are commands that don't + * actually transfer anything (FLUSH), so cannot use + * good_bytes != blk_rq_bytes(req) as the signal for an error. + * This sets the error explicitly for the problem case. + */ + error = __scsi_error_from_host_byte(cmd, result); } - /* - * Zero these out. They now point to freed memory, and it is - * dangerous to hang onto the pointers. - */ - cmd->buffer = NULL; - cmd->bufflen = 0; - cmd->request_buffer = NULL; - cmd->request_bufflen = 0; + /* no bidi support for !REQ_TYPE_BLOCK_PC yet */ + BUG_ON(blk_bidi_rq(req)); /* * Next deal with any sectors which we were able to correctly * handle. */ - if (good_bytes >= 0) { - SCSI_LOG_HLCOMPLETE(1, printk("%ld sectors total, %d bytes done.\n", - req->nr_sectors, good_bytes)); - SCSI_LOG_HLCOMPLETE(1, printk("use_sg is %d\n", cmd->use_sg)); + SCSI_LOG_HLCOMPLETE(1, printk("%u sectors total, " + "%d bytes done.\n", + blk_rq_sectors(req), good_bytes)); - if (clear_errors) - req->errors = 0; - /* - * If multiple sectors are requested in one buffer, then - * they will have been finished off by the first command. - * If not, then we have a multi-buffer command. - * - * If block_bytes != 0, it means we had a medium error - * of some sort, and that we want to mark some number of - * sectors as not uptodate. Thus we want to inhibit - * requeueing right here - we will requeue down below - * when we handle the bad sectors. + /* + * Recovered errors need reporting, but they're always treated + * as success, so fiddle the result code here. For BLOCK_PC + * we already took a copy of the original into rq->errors which + * is what gets returned to the user + */ + if (sense_valid && (sshdr.sense_key == RECOVERED_ERROR)) { + /* if ATA PASS-THROUGH INFORMATION AVAILABLE skip + * print since caller wants ATA registers. Only occurs on + * SCSI ATA PASS_THROUGH commands when CK_COND=1 */ + if ((sshdr.asc == 0x0) && (sshdr.ascq == 0x1d)) + ; + else if (!(req->cmd_flags & REQ_QUIET)) + scsi_print_sense("", cmd); + result = 0; + /* BLOCK_PC may have set error */ + error = 0; + } - /* - * If the command completed without error, then either - * finish off the rest of the command, or start a new one. - */ - if (scsi_end_request(cmd, 1, good_bytes, result == 0) == NULL) - return; + /* + * If we finished all bytes in the request we are done now. + */ + if (!blk_end_request(req, error, good_bytes)) + goto next_command; + + /* + * Kill remainder if no retrys. + */ + if (error && scsi_noretry_cmd(cmd)) { + blk_end_request_all(req, error); + goto next_command; } + /* - * Now, if we were good little boys and girls, Santa left us a request - * sense buffer. We can extract information from this, so we - * can choose a block to remap, etc. + * If there had been no error, but we have leftover bytes in the + * requeues just queue the command up again. */ - if (sense_valid && !sense_deferred) { + if (result == 0) + goto requeue; + + error = __scsi_error_from_host_byte(cmd, result); + + if (host_byte(result) == DID_RESET) { + /* Third party bus reset or reset for error recovery + * reasons. Just retry the command and see what + * happens. + */ + action = ACTION_RETRY; + } else if (sense_valid && !sense_deferred) { switch (sshdr.sense_key) { case UNIT_ATTENTION: if (cmd->device->removable) { - /* detected disc change. set a bit + /* Detected disc change. Set a bit * and quietly refuse further access. */ cmd->device->changed = 1; - scsi_end_request(cmd, 0, - this_count, 1); - return; + description = "Media Changed"; + action = ACTION_FAIL; } else { - /* - * Must have been a power glitch, or a - * bus reset. Could not have been a - * media change, so we just retry the - * request and see what happens. - */ - scsi_requeue_command(q, cmd); - return; + /* Must have been a power glitch, or a + * bus reset. Could not have been a + * media change, so we just retry the + * command and see what happens. + */ + action = ACTION_RETRY; } break; case ILLEGAL_REQUEST: - /* - * If we had an ILLEGAL REQUEST returned, then we may - * have performed an unsupported command. The only - * thing this should be would be a ten byte read where - * only a six byte read was supported. Also, on a - * system where READ CAPACITY failed, we may have read - * past the end of the disk. - */ - if (cmd->device->use_10_for_rw && + /* If we had an ILLEGAL REQUEST returned, then + * we may have performed an unsupported + * command. The only thing this should be + * would be a ten byte read where only a six + * byte read was supported. Also, on a system + * where READ CAPACITY failed, we may have + * read past the end of the disk. + */ + if ((cmd->device->use_10_for_rw && + sshdr.asc == 0x20 && sshdr.ascq == 0x00) && (cmd->cmnd[0] == READ_10 || cmd->cmnd[0] == WRITE_10)) { + /* This will issue a new 6-byte command. */ cmd->device->use_10_for_rw = 0; - /* - * This will cause a retry with a 6-byte - * command. - */ - scsi_requeue_command(q, cmd); - result = 0; - } else { - scsi_end_request(cmd, 0, this_count, 1); - return; + action = ACTION_REPREP; + } else if (sshdr.asc == 0x10) /* DIX */ { + description = "Host Data Integrity Failure"; + action = ACTION_FAIL; + error = -EILSEQ; + /* INVALID COMMAND OPCODE or INVALID FIELD IN CDB */ + } else if (sshdr.asc == 0x20 || sshdr.asc == 0x24) { + switch (cmd->cmnd[0]) { + case UNMAP: + description = "Discard failure"; + break; + case WRITE_SAME: + case WRITE_SAME_16: + if (cmd->cmnd[1] & 0x8) + description = "Discard failure"; + else + description = + "Write same failure"; + break; + default: + description = "Invalid command failure"; + break; + } + action = ACTION_FAIL; + error = -EREMOTEIO; + } else + action = ACTION_FAIL; + break; + case ABORTED_COMMAND: + action = ACTION_FAIL; + if (sshdr.asc == 0x10) { /* DIF */ + description = "Target Data Integrity Failure"; + error = -EILSEQ; } break; case NOT_READY: - /* - * If the device is in the process of becoming ready, - * retry. + /* If the device is in the process of becoming + * ready, or has a temporary blockage, retry. */ - if (sshdr.asc == 0x04 && sshdr.ascq == 0x01) { - scsi_requeue_command(q, cmd); - return; + if (sshdr.asc == 0x04) { + switch (sshdr.ascq) { + case 0x01: /* becoming ready */ + case 0x04: /* format in progress */ + case 0x05: /* rebuild in progress */ + case 0x06: /* recalculation in progress */ + case 0x07: /* operation in progress */ + case 0x08: /* Long write in progress */ + case 0x09: /* self test in progress */ + case 0x14: /* space allocation in progress */ + action = ACTION_DELAYED_RETRY; + break; + default: + description = "Device not ready"; + action = ACTION_FAIL; + break; + } + } else { + description = "Device not ready"; + action = ACTION_FAIL; } - if (!(req->flags & REQ_QUIET)) - dev_printk(KERN_INFO, - &cmd->device->sdev_gendev, - "Device not ready.\n"); - scsi_end_request(cmd, 0, this_count, 1); - return; + break; case VOLUME_OVERFLOW: - if (!(req->flags & REQ_QUIET)) { - dev_printk(KERN_INFO, - &cmd->device->sdev_gendev, - "Volume overflow, CDB: "); - __scsi_print_command(cmd->data_cmnd); - scsi_print_sense("", cmd); - } - scsi_end_request(cmd, 0, block_bytes, 1); - return; + /* See SSC3rXX or current. */ + action = ACTION_FAIL; + break; default: + description = "Unhandled sense code"; + action = ACTION_FAIL; break; } - } /* driver byte != 0 */ - if (host_byte(result) == DID_RESET) { - /* - * Third party bus reset or reset for error - * recovery reasons. Just retry the request - * and see what happens. - */ - scsi_requeue_command(q, cmd); - return; + } else { + description = "Unhandled error code"; + action = ACTION_FAIL; + } + + if (action != ACTION_FAIL && + time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) { + action = ACTION_FAIL; + description = "Command timed out"; } - if (result) { - if (!(req->flags & REQ_QUIET)) { - dev_printk(KERN_INFO, &cmd->device->sdev_gendev, - "SCSI error: return code = 0x%x\n", result); + switch (action) { + case ACTION_FAIL: + /* Give up and fail the remainder of the request */ + if (!(req->cmd_flags & REQ_QUIET)) { + if (description) + scmd_printk(KERN_INFO, cmd, "%s\n", + description); + scsi_print_result(cmd); if (driver_byte(result) & DRIVER_SENSE) scsi_print_sense("", cmd); + scsi_print_command(cmd); } - /* - * Mark a single buffer as not uptodate. Queue the remainder. - * We sometimes get this cruft in the event that a medium error - * isn't properly reported. + if (!blk_end_request_err(req, error)) + goto next_command; + /*FALLTHRU*/ + case ACTION_REPREP: + requeue: + /* Unprep the request and put it back at the head of the queue. + * A new command will be prepared and issued. */ - block_bytes = req->hard_cur_sectors << 9; - if (!block_bytes) - block_bytes = req->data_len; - scsi_end_request(cmd, 0, block_bytes, 1); + scsi_release_buffers(cmd); + scsi_requeue_command(q, cmd); + break; + case ACTION_RETRY: + /* Retry the same command immediately */ + __scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY, 0); + break; + case ACTION_DELAYED_RETRY: + /* Retry the same command after a delay */ + __scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY, 0); + break; } + return; + +next_command: + scsi_release_buffers(cmd); + scsi_next_command(cmd); +} + +static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb, + gfp_t gfp_mask) +{ + int count; + + /* + * If sg table allocation fails, requeue request later. + */ + if (unlikely(scsi_alloc_sgtable(sdb, req->nr_phys_segments, + gfp_mask))) { + return BLKPREP_DEFER; + } + + /* + * Next, walk the list, and fill in the addresses and sizes of + * each segment. + */ + count = blk_rq_map_sg(req->q, req, sdb->table.sgl); + BUG_ON(count > sdb->table.nents); + sdb->table.nents = count; + sdb->length = blk_rq_bytes(req); + return BLKPREP_OK; } -EXPORT_SYMBOL(scsi_io_completion); /* * Function: scsi_init_io() @@ -1011,291 +992,278 @@ EXPORT_SYMBOL(scsi_io_completion); * BLKPREP_DEFER if the failure is retryable * BLKPREP_KILL if the failure is fatal */ -static int scsi_init_io(struct scsi_cmnd *cmd) +int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask) { - struct request *req = cmd->request; - struct scatterlist *sgpnt; - int count; + struct scsi_device *sdev = cmd->device; + struct request *rq = cmd->request; + + int error = scsi_init_sgtable(rq, &cmd->sdb, gfp_mask); + if (error) + goto err_exit; + + if (blk_bidi_rq(rq)) { + struct scsi_data_buffer *bidi_sdb = kmem_cache_zalloc( + scsi_sdb_cache, GFP_ATOMIC); + if (!bidi_sdb) { + error = BLKPREP_DEFER; + goto err_exit; + } - /* - * if this is a rq->data based REQ_BLOCK_PC, setup for a non-sg xfer - */ - if ((req->flags & REQ_BLOCK_PC) && !req->bio) { - cmd->request_bufflen = req->data_len; - cmd->request_buffer = req->data; - req->buffer = req->data; - cmd->use_sg = 0; - return 0; + rq->next_rq->special = bidi_sdb; + error = scsi_init_sgtable(rq->next_rq, bidi_sdb, GFP_ATOMIC); + if (error) + goto err_exit; } - /* - * we used to not use scatter-gather for single segment request, - * but now we do (it makes highmem I/O easier to support without - * kmapping pages) - */ - cmd->use_sg = req->nr_phys_segments; + if (blk_integrity_rq(rq)) { + struct scsi_data_buffer *prot_sdb = cmd->prot_sdb; + int ivecs, count; - /* - * if sg table allocation fails, requeue request later. - */ - sgpnt = scsi_alloc_sgtable(cmd, GFP_ATOMIC); - if (unlikely(!sgpnt)) { - scsi_unprep_request(req); - return BLKPREP_DEFER; - } + BUG_ON(prot_sdb == NULL); + ivecs = blk_rq_count_integrity_sg(rq->q, rq->bio); - cmd->request_buffer = (char *) sgpnt; - cmd->request_bufflen = req->nr_sectors << 9; - if (blk_pc_request(req)) - cmd->request_bufflen = req->data_len; - req->buffer = NULL; + if (scsi_alloc_sgtable(prot_sdb, ivecs, gfp_mask)) { + error = BLKPREP_DEFER; + goto err_exit; + } - /* - * Next, walk the list, and fill in the addresses and sizes of - * each segment. - */ - count = blk_rq_map_sg(req->q, req, cmd->request_buffer); + count = blk_rq_map_integrity_sg(rq->q, rq->bio, + prot_sdb->table.sgl); + BUG_ON(unlikely(count > ivecs)); + BUG_ON(unlikely(count > queue_max_integrity_segments(rq->q))); - /* - * mapped well, send it off - */ - if (likely(count <= cmd->use_sg)) { - cmd->use_sg = count; - return 0; + cmd->prot_sdb = prot_sdb; + cmd->prot_sdb->table.nents = count; } - printk(KERN_ERR "Incorrect number of segments after building list\n"); - printk(KERN_ERR "counted %d, received %d\n", count, cmd->use_sg); - printk(KERN_ERR "req nr_sec %lu, cur_nr_sec %u\n", req->nr_sectors, - req->current_nr_sectors); + return BLKPREP_OK ; - /* release the command and kill it */ +err_exit: scsi_release_buffers(cmd); + cmd->request->special = NULL; scsi_put_command(cmd); - return BLKPREP_KILL; + put_device(&sdev->sdev_gendev); + return error; } +EXPORT_SYMBOL(scsi_init_io); -static int scsi_prepare_flush_fn(request_queue_t *q, struct request *rq) +static struct scsi_cmnd *scsi_get_cmd_from_req(struct scsi_device *sdev, + struct request *req) { - struct scsi_device *sdev = q->queuedata; - struct scsi_driver *drv; + struct scsi_cmnd *cmd; - if (sdev->sdev_state == SDEV_RUNNING) { - drv = *(struct scsi_driver **) rq->rq_disk->private_data; + if (!req->special) { + /* Bail if we can't get a reference to the device */ + if (!get_device(&sdev->sdev_gendev)) + return NULL; - if (drv->prepare_flush) - return drv->prepare_flush(q, rq); + cmd = scsi_get_command(sdev, GFP_ATOMIC); + if (unlikely(!cmd)) { + put_device(&sdev->sdev_gendev); + return NULL; + } + req->special = cmd; + } else { + cmd = req->special; } - return 0; + /* pull a tag out of the request if we have one */ + cmd->tag = req->tag; + cmd->request = req; + + cmd->cmnd = req->cmd; + cmd->prot_op = SCSI_PROT_NORMAL; + + return cmd; } -static void scsi_end_flush_fn(request_queue_t *q, struct request *rq) +int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req) { - struct scsi_device *sdev = q->queuedata; - struct request *flush_rq = rq->end_io_data; - struct scsi_driver *drv; + struct scsi_cmnd *cmd = req->special; - if (flush_rq->errors) { - printk("scsi: barrier error, disabling flush support\n"); - blk_queue_ordered(q, QUEUE_ORDERED_NONE); - } + /* + * BLOCK_PC requests may transfer data, in which case they must + * a bio attached to them. Or they might contain a SCSI command + * that does not transfer data, in which case they may optionally + * submit a request without an attached bio. + */ + if (req->bio) { + int ret; - if (sdev->sdev_state == SDEV_RUNNING) { - drv = *(struct scsi_driver **) rq->rq_disk->private_data; - drv->end_flush(q, rq); + BUG_ON(!req->nr_phys_segments); + + ret = scsi_init_io(cmd, GFP_ATOMIC); + if (unlikely(ret)) + return ret; + } else { + BUG_ON(blk_rq_bytes(req)); + + memset(&cmd->sdb, 0, sizeof(cmd->sdb)); } + + cmd->cmd_len = req->cmd_len; + if (!blk_rq_bytes(req)) + cmd->sc_data_direction = DMA_NONE; + else if (rq_data_dir(req) == WRITE) + cmd->sc_data_direction = DMA_TO_DEVICE; + else + cmd->sc_data_direction = DMA_FROM_DEVICE; + + cmd->transfersize = blk_rq_bytes(req); + cmd->allowed = req->retries; + return BLKPREP_OK; } +EXPORT_SYMBOL(scsi_setup_blk_pc_cmnd); -static int scsi_issue_flush_fn(request_queue_t *q, struct gendisk *disk, - sector_t *error_sector) +/* + * Setup a REQ_TYPE_FS command. These are simple read/write request + * from filesystems that still need to be translated to SCSI CDBs from + * the ULD. + */ +int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req) { - struct scsi_device *sdev = q->queuedata; - struct scsi_driver *drv; - - if (sdev->sdev_state != SDEV_RUNNING) - return -ENXIO; + struct scsi_cmnd *cmd = req->special; - drv = *(struct scsi_driver **) disk->private_data; - if (drv->issue_flush) - return drv->issue_flush(&sdev->sdev_gendev, error_sector); + if (unlikely(sdev->scsi_dh_data && sdev->scsi_dh_data->scsi_dh + && sdev->scsi_dh_data->scsi_dh->prep_fn)) { + int ret = sdev->scsi_dh_data->scsi_dh->prep_fn(sdev, req); + if (ret != BLKPREP_OK) + return ret; + } - return -EOPNOTSUPP; -} + /* + * Filesystem requests must transfer data. + */ + BUG_ON(!req->nr_phys_segments); -static void scsi_generic_done(struct scsi_cmnd *cmd) -{ - BUG_ON(!blk_pc_request(cmd->request)); - scsi_io_completion(cmd, cmd->result == 0 ? cmd->bufflen : 0, 0); + memset(cmd->cmnd, 0, BLK_MAX_CDB); + return scsi_init_io(cmd, GFP_ATOMIC); } +EXPORT_SYMBOL(scsi_setup_fs_cmnd); -static int scsi_prep_fn(struct request_queue *q, struct request *req) +static int +scsi_prep_state_check(struct scsi_device *sdev, struct request *req) { - struct scsi_device *sdev = q->queuedata; - struct scsi_cmnd *cmd; - int specials_only = 0; + int ret = BLKPREP_OK; /* - * Just check to see if the device is online. If it isn't, we - * refuse to process any commands. The device must be brought - * online before trying any recovery commands + * If the device is not in running state we will reject some + * or all commands. */ - if (unlikely(!scsi_device_online(sdev))) { - printk(KERN_ERR "scsi%d (%d:%d): rejecting I/O to offline device\n", - sdev->host->host_no, sdev->id, sdev->lun); - goto kill; - } if (unlikely(sdev->sdev_state != SDEV_RUNNING)) { - /* OK, we're not in a running state don't prep - * user commands */ - if (sdev->sdev_state == SDEV_DEL) { - /* Device is fully deleted, no commands - * at all allowed down */ - printk(KERN_ERR "scsi%d (%d:%d): rejecting I/O to dead device\n", - sdev->host->host_no, sdev->id, sdev->lun); - goto kill; + switch (sdev->sdev_state) { + case SDEV_OFFLINE: + case SDEV_TRANSPORT_OFFLINE: + /* + * If the device is offline we refuse to process any + * commands. The device must be brought online + * before trying any recovery commands. + */ + sdev_printk(KERN_ERR, sdev, + "rejecting I/O to offline device\n"); + ret = BLKPREP_KILL; + break; + case SDEV_DEL: + /* + * If the device is fully deleted, we refuse to + * process any commands as well. + */ + sdev_printk(KERN_ERR, sdev, + "rejecting I/O to dead device\n"); + ret = BLKPREP_KILL; + break; + case SDEV_QUIESCE: + case SDEV_BLOCK: + case SDEV_CREATED_BLOCK: + /* + * If the devices is blocked we defer normal commands. + */ + if (!(req->cmd_flags & REQ_PREEMPT)) + ret = BLKPREP_DEFER; + break; + default: + /* + * For any other not fully online state we only allow + * special commands. In particular any user initiated + * command is not allowed. + */ + if (!(req->cmd_flags & REQ_PREEMPT)) + ret = BLKPREP_KILL; + break; } - /* OK, we only allow special commands (i.e. not - * user initiated ones */ - specials_only = sdev->sdev_state; } + return ret; +} - /* - * Find the actual device driver associated with this command. - * The SPECIAL requests are things like character device or - * ioctls, which did not originate from ll_rw_blk. Note that - * the special field is also used to indicate the cmd for - * the remainder of a partially fulfilled request that can - * come up when there is a medium error. We have to treat - * these two cases differently. We differentiate by looking - * at request->cmd, as this tells us the real story. - */ - if (req->flags & REQ_SPECIAL && req->special) { - struct scsi_request *sreq = req->special; - - if (sreq->sr_magic == SCSI_REQ_MAGIC) { - cmd = scsi_get_command(sreq->sr_device, GFP_ATOMIC); - if (unlikely(!cmd)) - goto defer; - scsi_init_cmd_from_req(cmd, sreq); - } else - cmd = req->special; - } else if (req->flags & (REQ_CMD | REQ_BLOCK_PC)) { +static int +scsi_prep_return(struct request_queue *q, struct request *req, int ret) +{ + struct scsi_device *sdev = q->queuedata; - if(unlikely(specials_only) && !(req->flags & REQ_SPECIAL)) { - if(specials_only == SDEV_QUIESCE || - specials_only == SDEV_BLOCK) - goto defer; - - printk(KERN_ERR "scsi%d (%d:%d): rejecting I/O to device being removed\n", - sdev->host->host_no, sdev->id, sdev->lun); - goto kill; + switch (ret) { + case BLKPREP_KILL: + req->errors = DID_NO_CONNECT << 16; + /* release the command and kill it */ + if (req->special) { + struct scsi_cmnd *cmd = req->special; + scsi_release_buffers(cmd); + scsi_put_command(cmd); + put_device(&sdev->sdev_gendev); + req->special = NULL; } - - + break; + case BLKPREP_DEFER: /* - * Now try and find a command block that we can use. + * If we defer, the blk_peek_request() returns NULL, but the + * queue must be restarted, so we schedule a callback to happen + * shortly. */ - if (!req->special) { - cmd = scsi_get_command(sdev, GFP_ATOMIC); - if (unlikely(!cmd)) - goto defer; - } else - cmd = req->special; - - /* pull a tag out of the request if we have one */ - cmd->tag = req->tag; - } else { - blk_dump_rq_flags(req, "SCSI bad req"); - goto kill; + if (sdev->device_busy == 0) + blk_delay_queue(q, SCSI_QUEUE_DELAY); + break; + default: + req->cmd_flags |= REQ_DONTPREP; } - - /* note the overloading of req->special. When the tag - * is active it always means cmd. If the tag goes - * back for re-queueing, it may be reset */ - req->special = cmd; - cmd->request = req; - - /* - * FIXME: drop the lock here because the functions below - * expect to be called without the queue lock held. Also, - * previously, we dequeued the request before dropping the - * lock. We hope REQ_STARTED prevents anything untoward from - * happening now. - */ - if (req->flags & (REQ_CMD | REQ_BLOCK_PC)) { - struct scsi_driver *drv; - int ret; - /* - * This will do a couple of things: - * 1) Fill in the actual SCSI command. - * 2) Fill in any other upper-level specific fields - * (timeout). - * - * If this returns 0, it means that the request failed - * (reading past end of disk, reading offline device, - * etc). This won't actually talk to the device, but - * some kinds of consistency checking may cause the - * request to be rejected immediately. - */ + return ret; +} - /* - * This sets up the scatter-gather table (allocating if - * required). - */ - ret = scsi_init_io(cmd); - switch(ret) { - /* For BLKPREP_KILL/DEFER the cmd was released */ - case BLKPREP_KILL: - goto kill; - case BLKPREP_DEFER: - goto defer; - } - - /* - * Initialize the actual SCSI command for this request. - */ - if (req->rq_disk) { - drv = *(struct scsi_driver **)req->rq_disk->private_data; - if (unlikely(!drv->init_command(cmd))) { - scsi_release_buffers(cmd); - scsi_put_command(cmd); - goto kill; - } - } else { - memcpy(cmd->cmnd, req->cmd, sizeof(cmd->cmnd)); - cmd->cmd_len = req->cmd_len; - if (rq_data_dir(req) == WRITE) - cmd->sc_data_direction = DMA_TO_DEVICE; - else if (req->data_len) - cmd->sc_data_direction = DMA_FROM_DEVICE; - else - cmd->sc_data_direction = DMA_NONE; - - cmd->transfersize = req->data_len; - cmd->allowed = 3; - cmd->timeout_per_command = req->timeout; - cmd->done = scsi_generic_done; - } +static int scsi_prep_fn(struct request_queue *q, struct request *req) +{ + struct scsi_device *sdev = q->queuedata; + struct scsi_cmnd *cmd; + int ret; + + ret = scsi_prep_state_check(sdev, req); + if (ret != BLKPREP_OK) + goto out; + + cmd = scsi_get_cmd_from_req(sdev, req); + if (unlikely(!cmd)) { + ret = BLKPREP_DEFER; + goto out; } - /* - * The request is now prepped, no need to come back here - */ - req->flags |= REQ_DONTPREP; - return BLKPREP_OK; + if (req->cmd_type == REQ_TYPE_FS) + ret = scsi_cmd_to_driver(cmd)->init_command(cmd); + else if (req->cmd_type == REQ_TYPE_BLOCK_PC) + ret = scsi_setup_blk_pc_cmnd(sdev, req); + else + ret = BLKPREP_KILL; - defer: - /* If we defer, the elv_next_request() returns NULL, but the - * queue must be restarted, so we plug here if no returning - * command will automatically do that. */ - if (sdev->device_busy == 0) - blk_plug_device(q); - return BLKPREP_DEFER; - kill: - req->errors = DID_NO_CONNECT << 16; - return BLKPREP_KILL; +out: + return scsi_prep_return(q, req, ret); +} + +static void scsi_unprep_fn(struct request_queue *q, struct request *req) +{ + if (req->cmd_type == REQ_TYPE_FS) { + struct scsi_cmnd *cmd = req->special; + struct scsi_driver *drv = scsi_cmd_to_driver(cmd); + + if (drv->uninit_command) + drv->uninit_command(cmd); + } } /* @@ -1307,24 +1275,59 @@ static int scsi_prep_fn(struct request_queue *q, struct request *req) static inline int scsi_dev_queue_ready(struct request_queue *q, struct scsi_device *sdev) { - if (sdev->device_busy >= sdev->queue_depth) - return 0; if (sdev->device_busy == 0 && sdev->device_blocked) { /* * unblock after device_blocked iterates to zero */ if (--sdev->device_blocked == 0) { SCSI_LOG_MLQUEUE(3, - printk("scsi%d (%d:%d) unblocking device at" - " zero depth\n", sdev->host->host_no, - sdev->id, sdev->lun)); + sdev_printk(KERN_INFO, sdev, + "unblocking device at zero depth\n")); } else { - blk_plug_device(q); + blk_delay_queue(q, SCSI_QUEUE_DELAY); return 0; } } - if (sdev->device_blocked) + if (scsi_device_is_busy(sdev)) + return 0; + + return 1; +} + + +/* + * scsi_target_queue_ready: checks if there we can send commands to target + * @sdev: scsi device on starget to check. + * + * Called with the host lock held. + */ +static inline int scsi_target_queue_ready(struct Scsi_Host *shost, + struct scsi_device *sdev) +{ + struct scsi_target *starget = scsi_target(sdev); + + if (starget->single_lun) { + if (starget->starget_sdev_user && + starget->starget_sdev_user != sdev) + return 0; + starget->starget_sdev_user = sdev; + } + + if (starget->target_busy == 0 && starget->target_blocked) { + /* + * unblock after target_blocked iterates to zero + */ + if (--starget->target_blocked == 0) { + SCSI_LOG_MLQUEUE(3, starget_printk(KERN_INFO, starget, + "unblocking target at zero depth\n")); + } else + return 0; + } + + if (scsi_target_is_busy(starget)) { + list_move_tail(&sdev->starved_entry, &shost->starved_list); return 0; + } return 1; } @@ -1351,12 +1354,10 @@ static inline int scsi_host_queue_ready(struct request_queue *q, printk("scsi%d unblocking host at zero depth\n", shost->host_no)); } else { - blk_plug_device(q); return 0; } } - if ((shost->can_queue > 0 && shost->host_busy >= shost->can_queue) || - shost->host_blocked || shost->host_self_blocked) { + if (scsi_host_is_busy(shost)) { if (list_empty(&sdev->starved_entry)) list_add_tail(&sdev->starved_entry, &shost->starved_list); return 0; @@ -1370,24 +1371,113 @@ static inline int scsi_host_queue_ready(struct request_queue *q, } /* + * Busy state exporting function for request stacking drivers. + * + * For efficiency, no lock is taken to check the busy state of + * shost/starget/sdev, since the returned value is not guaranteed and + * may be changed after request stacking drivers call the function, + * regardless of taking lock or not. + * + * When scsi can't dispatch I/Os anymore and needs to kill I/Os scsi + * needs to return 'not busy'. Otherwise, request stacking drivers + * may hold requests forever. + */ +static int scsi_lld_busy(struct request_queue *q) +{ + struct scsi_device *sdev = q->queuedata; + struct Scsi_Host *shost; + + if (blk_queue_dying(q)) + return 0; + + shost = sdev->host; + + /* + * Ignore host/starget busy state. + * Since block layer does not have a concept of fairness across + * multiple queues, congestion of host/starget needs to be handled + * in SCSI layer. + */ + if (scsi_host_in_recovery(shost) || scsi_device_is_busy(sdev)) + return 1; + + return 0; +} + +/* * Kill a request for a dead device */ -static void scsi_kill_request(struct request *req, request_queue_t *q) +static void scsi_kill_request(struct request *req, struct request_queue *q) { struct scsi_cmnd *cmd = req->special; + struct scsi_device *sdev; + struct scsi_target *starget; + struct Scsi_Host *shost; - blkdev_dequeue_request(req); + blk_start_request(req); - if (unlikely(cmd == NULL)) { - printk(KERN_CRIT "impossible request in %s.\n", - __FUNCTION__); - BUG(); - } + scmd_printk(KERN_INFO, cmd, "killing request\n"); + sdev = cmd->device; + starget = scsi_target(sdev); + shost = sdev->host; scsi_init_cmd_errh(cmd); cmd->result = DID_NO_CONNECT << 16; atomic_inc(&cmd->device->iorequest_cnt); - __scsi_done(cmd); + + /* + * SCSI request completion path will do scsi_device_unbusy(), + * bump busy counts. To bump the counters, we need to dance + * with the locks as normal issue path does. + */ + sdev->device_busy++; + spin_unlock(sdev->request_queue->queue_lock); + spin_lock(shost->host_lock); + shost->host_busy++; + starget->target_busy++; + spin_unlock(shost->host_lock); + spin_lock(sdev->request_queue->queue_lock); + + blk_complete_request(req); +} + +static void scsi_softirq_done(struct request *rq) +{ + struct scsi_cmnd *cmd = rq->special; + unsigned long wait_for = (cmd->allowed + 1) * rq->timeout; + int disposition; + + INIT_LIST_HEAD(&cmd->eh_entry); + + atomic_inc(&cmd->device->iodone_cnt); + if (cmd->result) + atomic_inc(&cmd->device->ioerr_cnt); + + disposition = scsi_decide_disposition(cmd); + if (disposition != SUCCESS && + time_before(cmd->jiffies_at_alloc + wait_for, jiffies)) { + sdev_printk(KERN_ERR, cmd->device, + "timing out command, waited %lus\n", + wait_for/HZ); + disposition = SUCCESS; + } + + scsi_log_completion(cmd, disposition); + + switch (disposition) { + case SUCCESS: + scsi_finish_command(cmd); + break; + case NEEDS_RETRY: + scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY); + break; + case ADD_TO_MLQUEUE: + scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY); + break; + default: + if (!scsi_eh_scmd_add(cmd, 0)) + scsi_finish_command(cmd); + } } /* @@ -1402,42 +1492,33 @@ static void scsi_kill_request(struct request *req, request_queue_t *q) * Lock status: IO request lock assumed to be held when called. */ static void scsi_request_fn(struct request_queue *q) + __releases(q->queue_lock) + __acquires(q->queue_lock) { struct scsi_device *sdev = q->queuedata; struct Scsi_Host *shost; struct scsi_cmnd *cmd; struct request *req; - if (!sdev) { - printk("scsi: killing requests for dead queue\n"); - while ((req = elv_next_request(q)) != NULL) - scsi_kill_request(req, q); - return; - } - - if(!get_device(&sdev->sdev_gendev)) - /* We must be tearing the block queue down already */ - return; - /* * To start with, we keep looping until the queue is empty, or until * the host is no longer able to accept any more requests. */ shost = sdev->host; - while (!blk_queue_plugged(q)) { + for (;;) { int rtn; /* * get next queueable request. We do this early to make sure * that the request is fully prepared even if we cannot * accept it. */ - req = elv_next_request(q); + req = blk_peek_request(q); if (!req || !scsi_dev_queue_ready(q, sdev)) break; if (unlikely(!scsi_device_online(sdev))) { - printk(KERN_ERR "scsi%d (%d:%d): rejecting I/O to offline device\n", - sdev->host->host_no, sdev->id, sdev->lun); + sdev_printk(KERN_ERR, sdev, + "rejecting I/O to offline device\n"); scsi_kill_request(req, q); continue; } @@ -1447,7 +1528,7 @@ static void scsi_request_fn(struct request_queue *q) * Remove the request from the request list. */ if (!(blk_queue_tagged(q) && !blk_queue_start_tag(q, req))) - blkdev_dequeue_request(req); + blk_start_request(req); sdev->device_busy++; spin_unlock(q->queue_lock); @@ -1455,20 +1536,35 @@ static void scsi_request_fn(struct request_queue *q) if (unlikely(cmd == NULL)) { printk(KERN_CRIT "impossible request in %s.\n" "please mail a stack trace to " - "linux-scsi@vger.kernel.org", - __FUNCTION__); + "linux-scsi@vger.kernel.org\n", + __func__); + blk_dump_rq_flags(req, "foo"); BUG(); } spin_lock(shost->host_lock); - if (!scsi_host_queue_ready(q, shost, sdev)) + /* + * We hit this when the driver is using a host wide + * tag map. For device level tag maps the queue_depth check + * in the device ready fn would prevent us from trying + * to allocate a tag. Since the map is a shared host resource + * we add the dev to the starved list so it eventually gets + * a run when a tag is freed. + */ + if (blk_queue_tagged(q) && !blk_rq_tagged(req)) { + if (list_empty(&sdev->starved_entry)) + list_add_tail(&sdev->starved_entry, + &shost->starved_list); goto not_ready; - if (sdev->single_lun) { - if (scsi_target(sdev)->starget_sdev_user && - scsi_target(sdev)->starget_sdev_user != sdev) - goto not_ready; - scsi_target(sdev)->starget_sdev_user = sdev; } + + if (!scsi_target_queue_ready(shost, sdev)) + goto not_ready; + + if (!scsi_host_queue_ready(q, shost, sdev)) + goto not_ready; + + scsi_target(sdev)->target_busy++; shost->host_busy++; /* @@ -1488,18 +1584,11 @@ static void scsi_request_fn(struct request_queue *q) */ rtn = scsi_dispatch_cmd(cmd); spin_lock_irq(q->queue_lock); - if(rtn) { - /* we're refusing the command; because of - * the way locks get dropped, we need to - * check here if plugging is required */ - if(sdev->device_busy == 0) - blk_plug_device(q); - - break; - } + if (rtn) + goto out_delay; } - goto out; + return; not_ready: spin_unlock_irq(shost->host_lock); @@ -1515,14 +1604,9 @@ static void scsi_request_fn(struct request_queue *q) spin_lock_irq(q->queue_lock); blk_requeue_request(q, req); sdev->device_busy--; - if(sdev->device_busy == 0) - blk_plug_device(q); - out: - /* must be careful here...if we trigger the ->remove() function - * we cannot be holding the q lock */ - spin_unlock_irq(q->queue_lock); - put_device(&sdev->sdev_gendev); - spin_lock_irq(q->queue_lock); +out_delay: + if (sdev->device_busy == 0) + blk_delay_queue(q, SCSI_QUEUE_DELAY); } u64 scsi_calculate_bounce_limit(struct Scsi_Host *shost) @@ -1541,49 +1625,71 @@ u64 scsi_calculate_bounce_limit(struct Scsi_Host *shost) host_dev = scsi_get_device(shost); if (host_dev && host_dev->dma_mask) - bounce_limit = *host_dev->dma_mask; + bounce_limit = (u64)dma_max_pfn(host_dev) << PAGE_SHIFT; return bounce_limit; } EXPORT_SYMBOL(scsi_calculate_bounce_limit); -struct request_queue *scsi_alloc_queue(struct scsi_device *sdev) +struct request_queue *__scsi_alloc_queue(struct Scsi_Host *shost, + request_fn_proc *request_fn) { - struct Scsi_Host *shost = sdev->host; struct request_queue *q; + struct device *dev = shost->dma_dev; - q = blk_init_queue(scsi_request_fn, NULL); + q = blk_init_queue(request_fn, NULL); if (!q) return NULL; - blk_queue_prep_rq(q, scsi_prep_fn); + /* + * this limit is imposed by hardware restrictions + */ + blk_queue_max_segments(q, min_t(unsigned short, shost->sg_tablesize, + SCSI_MAX_SG_CHAIN_SEGMENTS)); + + if (scsi_host_prot_dma(shost)) { + shost->sg_prot_tablesize = + min_not_zero(shost->sg_prot_tablesize, + (unsigned short)SCSI_MAX_PROT_SG_SEGMENTS); + BUG_ON(shost->sg_prot_tablesize < shost->sg_tablesize); + blk_queue_max_integrity_segments(q, shost->sg_prot_tablesize); + } - blk_queue_max_hw_segments(q, shost->sg_tablesize); - blk_queue_max_phys_segments(q, SCSI_MAX_PHYS_SEGMENTS); - blk_queue_max_sectors(q, shost->max_sectors); + blk_queue_max_hw_sectors(q, shost->max_sectors); blk_queue_bounce_limit(q, scsi_calculate_bounce_limit(shost)); blk_queue_segment_boundary(q, shost->dma_boundary); - blk_queue_issue_flush_fn(q, scsi_issue_flush_fn); + dma_set_seg_boundary(dev, shost->dma_boundary); + + blk_queue_max_segment_size(q, dma_get_max_seg_size(dev)); + + if (!shost->use_clustering) + q->limits.cluster = 0; /* - * ordered tags are superior to flush ordering + * set a reasonable default alignment on word boundaries: the + * host and device may alter it using + * blk_queue_update_dma_alignment() later. */ - if (shost->ordered_tag) - blk_queue_ordered(q, QUEUE_ORDERED_TAG); - else if (shost->ordered_flush) { - blk_queue_ordered(q, QUEUE_ORDERED_FLUSH); - q->prepare_flush_fn = scsi_prepare_flush_fn; - q->end_flush_fn = scsi_end_flush_fn; - } + blk_queue_dma_alignment(q, 0x03); - if (!shost->use_clustering) - clear_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags); return q; } +EXPORT_SYMBOL(__scsi_alloc_queue); -void scsi_free_queue(struct request_queue *q) +struct request_queue *scsi_alloc_queue(struct scsi_device *sdev) { - blk_cleanup_queue(q); + struct request_queue *q; + + q = __scsi_alloc_queue(sdev->host, scsi_request_fn); + if (!q) + return NULL; + + blk_queue_prep_rq(q, scsi_prep_fn); + blk_queue_unprep_rq(q, scsi_unprep_fn); + blk_queue_softirq_done(q, scsi_softirq_done); + blk_queue_rq_timed_out(q, scsi_times_out); + blk_queue_lld_busy(q, scsi_lld_busy); + return q; } /* @@ -1639,42 +1745,142 @@ int __init scsi_init_queue(void) { int i; + scsi_sdb_cache = kmem_cache_create("scsi_data_buffer", + sizeof(struct scsi_data_buffer), + 0, 0, NULL); + if (!scsi_sdb_cache) { + printk(KERN_ERR "SCSI: can't init scsi sdb cache\n"); + return -ENOMEM; + } + for (i = 0; i < SG_MEMPOOL_NR; i++) { struct scsi_host_sg_pool *sgp = scsi_sg_pools + i; int size = sgp->size * sizeof(struct scatterlist); sgp->slab = kmem_cache_create(sgp->name, size, 0, - SLAB_HWCACHE_ALIGN, NULL, NULL); + SLAB_HWCACHE_ALIGN, NULL); if (!sgp->slab) { printk(KERN_ERR "SCSI: can't init sg slab %s\n", sgp->name); + goto cleanup_sdb; } - sgp->pool = mempool_create(SG_MEMPOOL_SIZE, - mempool_alloc_slab, mempool_free_slab, - sgp->slab); + sgp->pool = mempool_create_slab_pool(SG_MEMPOOL_SIZE, + sgp->slab); if (!sgp->pool) { printk(KERN_ERR "SCSI: can't init sg mempool %s\n", sgp->name); + goto cleanup_sdb; } } return 0; + +cleanup_sdb: + for (i = 0; i < SG_MEMPOOL_NR; i++) { + struct scsi_host_sg_pool *sgp = scsi_sg_pools + i; + if (sgp->pool) + mempool_destroy(sgp->pool); + if (sgp->slab) + kmem_cache_destroy(sgp->slab); + } + kmem_cache_destroy(scsi_sdb_cache); + + return -ENOMEM; } void scsi_exit_queue(void) { int i; + kmem_cache_destroy(scsi_sdb_cache); + for (i = 0; i < SG_MEMPOOL_NR; i++) { struct scsi_host_sg_pool *sgp = scsi_sg_pools + i; mempool_destroy(sgp->pool); kmem_cache_destroy(sgp->slab); } } + /** - * scsi_mode_sense - issue a mode sense, falling back from 10 to - * six bytes if necessary. + * scsi_mode_select - issue a mode select + * @sdev: SCSI device to be queried + * @pf: Page format bit (1 == standard, 0 == vendor specific) + * @sp: Save page bit (0 == don't save, 1 == save) + * @modepage: mode page being requested + * @buffer: request buffer (may not be smaller than eight bytes) + * @len: length of request buffer. + * @timeout: command timeout + * @retries: number of retries before failing + * @data: returns a structure abstracting the mode header data + * @sshdr: place to put sense data (or NULL if no sense to be collected). + * must be SCSI_SENSE_BUFFERSIZE big. + * + * Returns zero if successful; negative error number or scsi + * status on error + * + */ +int +scsi_mode_select(struct scsi_device *sdev, int pf, int sp, int modepage, + unsigned char *buffer, int len, int timeout, int retries, + struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) +{ + unsigned char cmd[10]; + unsigned char *real_buffer; + int ret; + + memset(cmd, 0, sizeof(cmd)); + cmd[1] = (pf ? 0x10 : 0) | (sp ? 0x01 : 0); + + if (sdev->use_10_for_ms) { + if (len > 65535) + return -EINVAL; + real_buffer = kmalloc(8 + len, GFP_KERNEL); + if (!real_buffer) + return -ENOMEM; + memcpy(real_buffer + 8, buffer, len); + len += 8; + real_buffer[0] = 0; + real_buffer[1] = 0; + real_buffer[2] = data->medium_type; + real_buffer[3] = data->device_specific; + real_buffer[4] = data->longlba ? 0x01 : 0; + real_buffer[5] = 0; + real_buffer[6] = data->block_descriptor_length >> 8; + real_buffer[7] = data->block_descriptor_length; + + cmd[0] = MODE_SELECT_10; + cmd[7] = len >> 8; + cmd[8] = len; + } else { + if (len > 255 || data->block_descriptor_length > 255 || + data->longlba) + return -EINVAL; + + real_buffer = kmalloc(4 + len, GFP_KERNEL); + if (!real_buffer) + return -ENOMEM; + memcpy(real_buffer + 4, buffer, len); + len += 4; + real_buffer[0] = 0; + real_buffer[1] = data->medium_type; + real_buffer[2] = data->device_specific; + real_buffer[3] = data->block_descriptor_length; + + + cmd[0] = MODE_SELECT; + cmd[4] = len; + } + + ret = scsi_execute_req(sdev, cmd, DMA_TO_DEVICE, real_buffer, len, + sshdr, timeout, retries, NULL); + kfree(real_buffer); + return ret; +} +EXPORT_SYMBOL_GPL(scsi_mode_select); + +/** + * scsi_mode_sense - issue a mode sense, falling back from 10 to six bytes if necessary. * @sdev: SCSI device to be queried * @dbd: set if mode sense will allow block descriptors to be returned * @modepage: mode page being requested @@ -1683,17 +1889,18 @@ void scsi_exit_queue(void) * @timeout: command timeout * @retries: number of retries before failing * @data: returns a structure abstracting the mode header data - * @sense: place to put sense data (or NULL if no sense to be collected). + * @sshdr: place to put sense data (or NULL if no sense to be collected). * must be SCSI_SENSE_BUFFERSIZE big. * * Returns zero if unsuccessful, or the header offset (either 4 * or 8 depending on whether a six or ten byte command was * issued) if successful. - **/ + */ int scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage, unsigned char *buffer, int len, int timeout, int retries, - struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) { + struct scsi_mode_data *data, struct scsi_sense_hdr *sshdr) +{ unsigned char cmd[12]; int use_10_for_ms; int header_length; @@ -1731,7 +1938,7 @@ scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage, memset(buffer, 0, len); result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buffer, len, - sshdr, timeout, retries); + sshdr, timeout, retries, NULL); /* This code looks awful: what it's doing is making sure an * ILLEGAL REQUEST sense return identifies the actual command @@ -1753,8 +1960,16 @@ scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage, } if(scsi_status_is_good(result)) { - data->header_length = header_length; - if(use_10_for_ms) { + if (unlikely(buffer[0] == 0x86 && buffer[1] == 0x0b && + (modepage == 6 || modepage == 8))) { + /* Initio breakage? */ + header_length = 0; + data->length = 13; + data->medium_type = 0; + data->device_specific = 0; + data->longlba = 0; + data->block_descriptor_length = 0; + } else if(use_10_for_ms) { data->length = buffer[0]*256 + buffer[1] + 2; data->medium_type = buffer[2]; data->device_specific = buffer[3]; @@ -1767,46 +1982,64 @@ scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage, data->device_specific = buffer[2]; data->block_descriptor_length = buffer[3]; } + data->header_length = header_length; } return result; } EXPORT_SYMBOL(scsi_mode_sense); +/** + * scsi_test_unit_ready - test if unit is ready + * @sdev: scsi device to change the state of. + * @timeout: command timeout + * @retries: number of retries before failing + * @sshdr_external: Optional pointer to struct scsi_sense_hdr for + * returning sense. Make sure that this is cleared before passing + * in. + * + * Returns zero if unsuccessful or an error if TUR failed. For + * removable media, UNIT_ATTENTION sets ->changed flag. + **/ int -scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries) +scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries, + struct scsi_sense_hdr *sshdr_external) { char cmd[] = { TEST_UNIT_READY, 0, 0, 0, 0, 0, }; - struct scsi_sense_hdr sshdr; + struct scsi_sense_hdr *sshdr; int result; - - result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, &sshdr, - timeout, retries); - - if ((driver_byte(result) & DRIVER_SENSE) && sdev->removable) { - if ((scsi_sense_valid(&sshdr)) && - ((sshdr.sense_key == UNIT_ATTENTION) || - (sshdr.sense_key == NOT_READY))) { + if (!sshdr_external) + sshdr = kzalloc(sizeof(*sshdr), GFP_KERNEL); + else + sshdr = sshdr_external; + + /* try to eat the UNIT_ATTENTION if there are enough retries */ + do { + result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL, 0, sshdr, + timeout, retries, NULL); + if (sdev->removable && scsi_sense_valid(sshdr) && + sshdr->sense_key == UNIT_ATTENTION) sdev->changed = 1; - result = 0; - } - } + } while (scsi_sense_valid(sshdr) && + sshdr->sense_key == UNIT_ATTENTION && --retries); + + if (!sshdr_external) + kfree(sshdr); return result; } EXPORT_SYMBOL(scsi_test_unit_ready); /** - * scsi_device_set_state - Take the given device through the device - * state model. + * scsi_device_set_state - Take the given device through the device state model. * @sdev: scsi device to change the state of. * @state: state to change to. * * Returns zero if unsuccessful or an error if the requested * transition is illegal. - **/ + */ int scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state) { @@ -1817,15 +2050,19 @@ scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state) switch (state) { case SDEV_CREATED: - /* There are no legal states that come back to - * created. This is the manually initialised start - * state */ - goto illegal; + switch (oldstate) { + case SDEV_CREATED_BLOCK: + break; + default: + goto illegal; + } + break; case SDEV_RUNNING: switch (oldstate) { case SDEV_CREATED: case SDEV_OFFLINE: + case SDEV_TRANSPORT_OFFLINE: case SDEV_QUIESCE: case SDEV_BLOCK: break; @@ -1838,6 +2075,7 @@ scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state) switch (oldstate) { case SDEV_RUNNING: case SDEV_OFFLINE: + case SDEV_TRANSPORT_OFFLINE: break; default: goto illegal; @@ -1845,6 +2083,7 @@ scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state) break; case SDEV_OFFLINE: + case SDEV_TRANSPORT_OFFLINE: switch (oldstate) { case SDEV_CREATED: case SDEV_RUNNING: @@ -1858,8 +2097,17 @@ scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state) case SDEV_BLOCK: switch (oldstate) { - case SDEV_CREATED: case SDEV_RUNNING: + case SDEV_CREATED_BLOCK: + break; + default: + goto illegal; + } + break; + + case SDEV_CREATED_BLOCK: + switch (oldstate) { + case SDEV_CREATED: break; default: goto illegal; @@ -1870,7 +2118,9 @@ scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state) switch (oldstate) { case SDEV_CREATED: case SDEV_RUNNING: + case SDEV_QUIESCE: case SDEV_OFFLINE: + case SDEV_TRANSPORT_OFFLINE: case SDEV_BLOCK: break; default: @@ -1880,7 +2130,12 @@ scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state) case SDEV_DEL: switch (oldstate) { + case SDEV_CREATED: + case SDEV_RUNNING: + case SDEV_OFFLINE: + case SDEV_TRANSPORT_OFFLINE: case SDEV_CANCEL: + case SDEV_CREATED_BLOCK: break; default: goto illegal; @@ -1893,16 +2148,181 @@ scsi_device_set_state(struct scsi_device *sdev, enum scsi_device_state state) illegal: SCSI_LOG_ERROR_RECOVERY(1, - dev_printk(KERN_ERR, &sdev->sdev_gendev, - "Illegal state transition %s->%s\n", - scsi_device_state_name(oldstate), - scsi_device_state_name(state)) + sdev_printk(KERN_ERR, sdev, + "Illegal state transition %s->%s\n", + scsi_device_state_name(oldstate), + scsi_device_state_name(state)) ); return -EINVAL; } EXPORT_SYMBOL(scsi_device_set_state); /** + * sdev_evt_emit - emit a single SCSI device uevent + * @sdev: associated SCSI device + * @evt: event to emit + * + * Send a single uevent (scsi_event) to the associated scsi_device. + */ +static void scsi_evt_emit(struct scsi_device *sdev, struct scsi_event *evt) +{ + int idx = 0; + char *envp[3]; + + switch (evt->evt_type) { + case SDEV_EVT_MEDIA_CHANGE: + envp[idx++] = "SDEV_MEDIA_CHANGE=1"; + break; + case SDEV_EVT_INQUIRY_CHANGE_REPORTED: + envp[idx++] = "SDEV_UA=INQUIRY_DATA_HAS_CHANGED"; + break; + case SDEV_EVT_CAPACITY_CHANGE_REPORTED: + envp[idx++] = "SDEV_UA=CAPACITY_DATA_HAS_CHANGED"; + break; + case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED: + envp[idx++] = "SDEV_UA=THIN_PROVISIONING_SOFT_THRESHOLD_REACHED"; + break; + case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED: + envp[idx++] = "SDEV_UA=MODE_PARAMETERS_CHANGED"; + break; + case SDEV_EVT_LUN_CHANGE_REPORTED: + envp[idx++] = "SDEV_UA=REPORTED_LUNS_DATA_HAS_CHANGED"; + break; + default: + /* do nothing */ + break; + } + + envp[idx++] = NULL; + + kobject_uevent_env(&sdev->sdev_gendev.kobj, KOBJ_CHANGE, envp); +} + +/** + * sdev_evt_thread - send a uevent for each scsi event + * @work: work struct for scsi_device + * + * Dispatch queued events to their associated scsi_device kobjects + * as uevents. + */ +void scsi_evt_thread(struct work_struct *work) +{ + struct scsi_device *sdev; + enum scsi_device_event evt_type; + LIST_HEAD(event_list); + + sdev = container_of(work, struct scsi_device, event_work); + + for (evt_type = SDEV_EVT_FIRST; evt_type <= SDEV_EVT_LAST; evt_type++) + if (test_and_clear_bit(evt_type, sdev->pending_events)) + sdev_evt_send_simple(sdev, evt_type, GFP_KERNEL); + + while (1) { + struct scsi_event *evt; + struct list_head *this, *tmp; + unsigned long flags; + + spin_lock_irqsave(&sdev->list_lock, flags); + list_splice_init(&sdev->event_list, &event_list); + spin_unlock_irqrestore(&sdev->list_lock, flags); + + if (list_empty(&event_list)) + break; + + list_for_each_safe(this, tmp, &event_list) { + evt = list_entry(this, struct scsi_event, node); + list_del(&evt->node); + scsi_evt_emit(sdev, evt); + kfree(evt); + } + } +} + +/** + * sdev_evt_send - send asserted event to uevent thread + * @sdev: scsi_device event occurred on + * @evt: event to send + * + * Assert scsi device event asynchronously. + */ +void sdev_evt_send(struct scsi_device *sdev, struct scsi_event *evt) +{ + unsigned long flags; + +#if 0 + /* FIXME: currently this check eliminates all media change events + * for polled devices. Need to update to discriminate between AN + * and polled events */ + if (!test_bit(evt->evt_type, sdev->supported_events)) { + kfree(evt); + return; + } +#endif + + spin_lock_irqsave(&sdev->list_lock, flags); + list_add_tail(&evt->node, &sdev->event_list); + schedule_work(&sdev->event_work); + spin_unlock_irqrestore(&sdev->list_lock, flags); +} +EXPORT_SYMBOL_GPL(sdev_evt_send); + +/** + * sdev_evt_alloc - allocate a new scsi event + * @evt_type: type of event to allocate + * @gfpflags: GFP flags for allocation + * + * Allocates and returns a new scsi_event. + */ +struct scsi_event *sdev_evt_alloc(enum scsi_device_event evt_type, + gfp_t gfpflags) +{ + struct scsi_event *evt = kzalloc(sizeof(struct scsi_event), gfpflags); + if (!evt) + return NULL; + + evt->evt_type = evt_type; + INIT_LIST_HEAD(&evt->node); + + /* evt_type-specific initialization, if any */ + switch (evt_type) { + case SDEV_EVT_MEDIA_CHANGE: + case SDEV_EVT_INQUIRY_CHANGE_REPORTED: + case SDEV_EVT_CAPACITY_CHANGE_REPORTED: + case SDEV_EVT_SOFT_THRESHOLD_REACHED_REPORTED: + case SDEV_EVT_MODE_PARAMETER_CHANGE_REPORTED: + case SDEV_EVT_LUN_CHANGE_REPORTED: + default: + /* do nothing */ + break; + } + + return evt; +} +EXPORT_SYMBOL_GPL(sdev_evt_alloc); + +/** + * sdev_evt_send_simple - send asserted event to uevent thread + * @sdev: scsi_device event occurred on + * @evt_type: type of event to send + * @gfpflags: GFP flags for allocation + * + * Assert scsi device event asynchronously, given an event type. + */ +void sdev_evt_send_simple(struct scsi_device *sdev, + enum scsi_device_event evt_type, gfp_t gfpflags) +{ + struct scsi_event *evt = sdev_evt_alloc(evt_type, gfpflags); + if (!evt) { + sdev_printk(KERN_ERR, sdev, "event %d eaten due to OOM\n", + evt_type); + return; + } + + sdev_evt_send(sdev, evt); +} +EXPORT_SYMBOL_GPL(sdev_evt_send_simple); + +/** * scsi_device_quiesce - Block user issued commands. * @sdev: scsi device to quiesce. * @@ -1916,7 +2336,7 @@ EXPORT_SYMBOL(scsi_device_set_state); * Must be called with user context, may sleep. * * Returns zero if unsuccessful or an error if not. - **/ + */ int scsi_device_quiesce(struct scsi_device *sdev) { @@ -1941,11 +2361,15 @@ EXPORT_SYMBOL(scsi_device_quiesce); * queues. * * Must be called with user context, may sleep. - **/ -void -scsi_device_resume(struct scsi_device *sdev) + */ +void scsi_device_resume(struct scsi_device *sdev) { - if(scsi_device_set_state(sdev, SDEV_RUNNING)) + /* check if the device state was mutated prior to resume, and if + * so assume the state is being managed elsewhere (for example + * device deleted during suspend) + */ + if (sdev->sdev_state != SDEV_QUIESCE || + scsi_device_set_state(sdev, SDEV_RUNNING)) return; scsi_run_queue(sdev->request_queue); } @@ -1978,8 +2402,7 @@ scsi_target_resume(struct scsi_target *starget) EXPORT_SYMBOL(scsi_target_resume); /** - * scsi_internal_device_block - internal function to put a device - * temporarily into the SDEV_BLOCK state + * scsi_internal_device_block - internal function to put a device temporarily into the SDEV_BLOCK state * @sdev: device to block * * Block request made by scsi lld's to temporarily stop all @@ -1993,18 +2416,21 @@ EXPORT_SYMBOL(scsi_target_resume); * (which must be a legal transition). When the device is in this * state, all commands are deferred until the scsi lld reenables * the device with scsi_device_unblock or device_block_tmo fires. - * This routine assumes the host_lock is held on entry. - **/ + */ int scsi_internal_device_block(struct scsi_device *sdev) { - request_queue_t *q = sdev->request_queue; + struct request_queue *q = sdev->request_queue; unsigned long flags; int err = 0; err = scsi_device_set_state(sdev, SDEV_BLOCK); - if (err) - return err; + if (err) { + err = scsi_device_set_state(sdev, SDEV_CREATED_BLOCK); + + if (err) + return err; + } /* * The device has transitioned to SDEV_BLOCK. Stop the @@ -2022,6 +2448,7 @@ EXPORT_SYMBOL_GPL(scsi_internal_device_block); /** * scsi_internal_device_unblock - resume a device after a block request * @sdev: device to resume + * @new_state: state to set devices to after unblocking * * Called by scsi lld's or the midlayer to restart the device queue * for the previously suspended scsi device. Called from interrupt or @@ -2031,24 +2458,32 @@ EXPORT_SYMBOL_GPL(scsi_internal_device_block); * * Notes: * This routine transitions the device to the SDEV_RUNNING state - * (which must be a legal transition) allowing the midlayer to - * goose the queue for this device. This routine assumes the - * host_lock is held upon entry. - **/ + * or to one of the offline states (which must be a legal transition) + * allowing the midlayer to goose the queue for this device. + */ int -scsi_internal_device_unblock(struct scsi_device *sdev) +scsi_internal_device_unblock(struct scsi_device *sdev, + enum scsi_device_state new_state) { - request_queue_t *q = sdev->request_queue; - int err; + struct request_queue *q = sdev->request_queue; unsigned long flags; - - /* - * Try to transition the scsi device to SDEV_RUNNING - * and goose the device queue if successful. + + /* + * Try to transition the scsi device to SDEV_RUNNING or one of the + * offlined states and goose the device queue if successful. */ - err = scsi_device_set_state(sdev, SDEV_RUNNING); - if (err) - return err; + if ((sdev->sdev_state == SDEV_BLOCK) || + (sdev->sdev_state == SDEV_TRANSPORT_OFFLINE)) + sdev->sdev_state = new_state; + else if (sdev->sdev_state == SDEV_CREATED_BLOCK) { + if (new_state == SDEV_TRANSPORT_OFFLINE || + new_state == SDEV_OFFLINE) + sdev->sdev_state = new_state; + else + sdev->sdev_state = SDEV_CREATED; + } else if (sdev->sdev_state != SDEV_CANCEL && + sdev->sdev_state != SDEV_OFFLINE) + return -EINVAL; spin_lock_irqsave(q->queue_lock, flags); blk_start_queue(q); @@ -2087,25 +2522,99 @@ EXPORT_SYMBOL_GPL(scsi_target_block); static void device_unblock(struct scsi_device *sdev, void *data) { - scsi_internal_device_unblock(sdev); + scsi_internal_device_unblock(sdev, *(enum scsi_device_state *)data); } static int target_unblock(struct device *dev, void *data) { if (scsi_is_target_device(dev)) - starget_for_each_device(to_scsi_target(dev), NULL, + starget_for_each_device(to_scsi_target(dev), data, device_unblock); return 0; } void -scsi_target_unblock(struct device *dev) +scsi_target_unblock(struct device *dev, enum scsi_device_state new_state) { if (scsi_is_target_device(dev)) - starget_for_each_device(to_scsi_target(dev), NULL, + starget_for_each_device(to_scsi_target(dev), &new_state, device_unblock); else - device_for_each_child(dev, NULL, target_unblock); + device_for_each_child(dev, &new_state, target_unblock); } EXPORT_SYMBOL_GPL(scsi_target_unblock); + +/** + * scsi_kmap_atomic_sg - find and atomically map an sg-elemnt + * @sgl: scatter-gather list + * @sg_count: number of segments in sg + * @offset: offset in bytes into sg, on return offset into the mapped area + * @len: bytes to map, on return number of bytes mapped + * + * Returns virtual address of the start of the mapped page + */ +void *scsi_kmap_atomic_sg(struct scatterlist *sgl, int sg_count, + size_t *offset, size_t *len) +{ + int i; + size_t sg_len = 0, len_complete = 0; + struct scatterlist *sg; + struct page *page; + + WARN_ON(!irqs_disabled()); + + for_each_sg(sgl, sg, sg_count, i) { + len_complete = sg_len; /* Complete sg-entries */ + sg_len += sg->length; + if (sg_len > *offset) + break; + } + + if (unlikely(i == sg_count)) { + printk(KERN_ERR "%s: Bytes in sg: %zu, requested offset %zu, " + "elements %d\n", + __func__, sg_len, *offset, sg_count); + WARN_ON(1); + return NULL; + } + + /* Offset starting from the beginning of first page in this sg-entry */ + *offset = *offset - len_complete + sg->offset; + + /* Assumption: contiguous pages can be accessed as "page + i" */ + page = nth_page(sg_page(sg), (*offset >> PAGE_SHIFT)); + *offset &= ~PAGE_MASK; + + /* Bytes in this sg-entry from *offset to the end of the page */ + sg_len = PAGE_SIZE - *offset; + if (*len > sg_len) + *len = sg_len; + + return kmap_atomic(page); +} +EXPORT_SYMBOL(scsi_kmap_atomic_sg); + +/** + * scsi_kunmap_atomic_sg - atomically unmap a virtual address, previously mapped with scsi_kmap_atomic_sg + * @virt: virtual address to be unmapped + */ +void scsi_kunmap_atomic_sg(void *virt) +{ + kunmap_atomic(virt); +} +EXPORT_SYMBOL(scsi_kunmap_atomic_sg); + +void sdev_disable_disk_events(struct scsi_device *sdev) +{ + atomic_inc(&sdev->disk_events_disable_depth); +} +EXPORT_SYMBOL(sdev_disable_disk_events); + +void sdev_enable_disk_events(struct scsi_device *sdev) +{ + if (WARN_ON_ONCE(atomic_read(&sdev->disk_events_disable_depth) <= 0)) + return; + atomic_dec(&sdev->disk_events_disable_depth); +} +EXPORT_SYMBOL(sdev_enable_disk_events); |