*/
#include <linux/bio.h>
+#include <linux/bitops.h>
#include <linux/blkdev.h>
#include <linux/completion.h>
#include <linux/kernel.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
-
-/*
- * 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.
- */
-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;
-}
+struct kmem_cache *scsi_sdb_cache;
static void scsi_run_queue(struct request_queue *q);
-static void scsi_release_buffers(struct scsi_cmnd *cmd);
/*
* Function: scsi_unprep_request()
{
struct scsi_cmnd *cmd = req->special;
- req->flags &= ~REQ_DONTPREP;
- req->special = (req->flags & REQ_SPECIAL) ? cmd->sc_request : NULL;
+ req->cmd_flags &= ~REQ_DONTPREP;
+ req->special = NULL;
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 int __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;
* 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:
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
}
/*
- * 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)
+int 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);
+ return __scsi_queue_insert(cmd, reason, 1);
}
-
-EXPORT_SYMBOL(scsi_wait_req);
-
/**
* scsi_execute - insert request and wait for the result
* @sdev: scsi device
* @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, int flags,
+ int *resid)
{
struct request *req;
int write = (data_direction == DMA_TO_DEVICE);
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_type = REQ_TYPE_BLOCK_PC;
+ 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);
int scsi_execute_req(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)
{
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, 0, resid);
if (sshdr)
scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, sshdr);
*
* 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);
spin_unlock_irqrestore(shost->host_lock, flags);
}
+static inline int scsi_device_is_busy(struct scsi_device *sdev)
+{
+ if (sdev->device_busy >= sdev->queue_depth || sdev->device_blocked)
+ return 1;
+
+ 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;
+}
+
/*
* Function: scsi_run_queue()
*
{
struct scsi_device *sdev = q->queuedata;
struct Scsi_Host *shost = sdev->host;
+ LIST_HEAD(starved_list);
unsigned long flags;
- if (sdev->single_lun)
+ if (scsi_target(sdev)->single_lun)
scsi_single_lun_run(sdev);
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)) {
+ int flagset;
+
/*
* As long as shost is accepting commands and we have
* starved queues, call blk_run_queue. scsi_request_fn
* 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);
- spin_unlock_irqrestore(shost->host_lock, flags);
+ if (scsi_target_is_busy(scsi_target(sdev))) {
+ list_move_tail(&sdev->starved_entry,
+ &shost->starved_list);
+ continue;
+ }
- blk_run_queue(sdev->request_queue);
+ spin_unlock(shost->host_lock);
- 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;
+ spin_lock(sdev->request_queue->queue_lock);
+ flagset = test_bit(QUEUE_FLAG_REENTER, &q->queue_flags) &&
+ !test_bit(QUEUE_FLAG_REENTER,
+ &sdev->request_queue->queue_flags);
+ if (flagset)
+ queue_flag_set(QUEUE_FLAG_REENTER, sdev->request_queue);
+ __blk_run_queue(sdev->request_queue);
+ if (flagset)
+ queue_flag_clear(QUEUE_FLAG_REENTER, sdev->request_queue);
+ spin_unlock(sdev->request_queue->queue_lock);
+
+ spin_lock(shost->host_lock);
}
+ /* put any unprocessed entries back */
+ list_splice(&starved_list, &shost->starved_list);
spin_unlock_irqrestore(shost->host_lock, flags);
blk_run_queue(q);
struct request *req = cmd->request;
unsigned long flags;
- scsi_unprep_request(req);
spin_lock_irqsave(q->queue_lock, flags);
+ scsi_unprep_request(req);
blk_requeue_request(q, req);
spin_unlock_irqrestore(q->queue_lock, flags);
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;
+
+ /* need to hold a reference on the device before we let go of the cmd */
+ get_device(&sdev->sdev_gendev);
scsi_put_command(cmd);
scsi_run_queue(q);
+
+ /* ok to remove device now */
+ put_device(&sdev->sdev_gendev);
}
void scsi_run_host_queues(struct Scsi_Host *shost)
scsi_run_queue(sdev->request_queue);
}
+static void __scsi_release_buffers(struct scsi_cmnd *, int);
+
/*
* Function: scsi_end_request()
*
* 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.
+ * error - 0 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.
*
* 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,
+static struct scsi_cmnd *scsi_end_request(struct scsi_cmnd *cmd, int error,
int bytes, int requeue)
{
- request_queue_t *q = cmd->device->request_queue;
+ struct request_queue *q = cmd->device->request_queue;
struct request *req = cmd->request;
- unsigned long flags;
/*
* 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);
-
- if (blk_pc_request(req))
- leftover = req->data_len;
-
+ if (blk_end_request(req, error, bytes)) {
/* kill remainder if no retrys */
- if (!uptodate && blk_noretry_request(req))
- end_that_request_chunk(req, 0, leftover);
+ if (error && scsi_noretry_cmd(cmd))
+ blk_end_request_all(req, error);
else {
if (requeue) {
/*
* leftovers in the front of the
* queue, and goose the queue again.
*/
+ scsi_release_buffers(cmd);
scsi_requeue_command(q, cmd);
cmd = NULL;
}
}
}
- 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);
-
/*
* This will goose the queue request function at the end, so we don't
* need to worry about launching another command.
*/
+ __scsi_release_buffers(cmd, 0);
scsi_next_command(cmd);
return NULL;
}
-static struct scatterlist *scsi_alloc_sgtable(struct scsi_cmnd *cmd, int gfp_mask)
+static inline unsigned int scsi_sgtable_index(unsigned short nents)
{
- struct scsi_host_sg_pool *sgp;
- struct scatterlist *sgl;
+ unsigned int index;
- BUG_ON(!cmd->use_sg);
+ BUG_ON(nents > SCSI_MAX_SG_SEGMENTS);
- 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;
- }
+ if (nents <= 8)
+ index = 0;
+ else
+ index = get_count_order(nents) - 3;
- sgp = scsi_sg_pools + cmd->sglist_len;
- sgl = mempool_alloc(sgp->pool, gfp_mask);
- return sgl;
+ return index;
}
-static void scsi_free_sgtable(struct scatterlist *sgl, int index)
+static void scsi_sg_free(struct scatterlist *sgl, unsigned int nents)
{
struct scsi_host_sg_pool *sgp;
- BUG_ON(index >= SG_MEMPOOL_NR);
-
- sgp = scsi_sg_pools + index;
+ sgp = scsi_sg_pools + scsi_sgtable_index(nents);
mempool_free(sgl, sgp->pool);
}
+static struct scatterlist *scsi_sg_alloc(unsigned int nents, gfp_t gfp_mask)
+{
+ struct scsi_host_sg_pool *sgp;
+
+ sgp = scsi_sg_pools + scsi_sgtable_index(nents);
+ return mempool_alloc(sgp->pool, gfp_mask);
+}
+
+static int scsi_alloc_sgtable(struct scsi_data_buffer *sdb, int nents,
+ gfp_t gfp_mask)
+{
+ int ret;
+
+ BUG_ON(!nents);
+
+ 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);
+}
+
+static void __scsi_release_buffers(struct scsi_cmnd *cmd, int do_bidi_check)
+{
+
+ if (cmd->sdb.table.nents)
+ scsi_free_sgtable(&cmd->sdb);
+
+ memset(&cmd->sdb, 0, sizeof(cmd->sdb));
+
+ if (do_bidi_check && scsi_bidi_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;
+ }
+
+ if (scsi_prot_sg_count(cmd))
+ scsi_free_sgtable(cmd->prot_sdb);
+}
+
/*
* Function: scsi_release_buffers()
*
* the scatter-gather table, and potentially any bounce
* buffers.
*/
-static void scsi_release_buffers(struct scsi_cmnd *cmd)
+void scsi_release_buffers(struct scsi_cmnd *cmd)
{
- struct request *req = cmd->request;
-
- /*
- * 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);
-
- /*
- * 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;
+ __scsi_release_buffers(cmd, 1);
}
+EXPORT_SYMBOL(scsi_release_buffers);
/*
* Function: scsi_io_completion()
* (the normal case for most drivers), we don't need
* the logic to deal with cleaning up afterwards.
*
- * We must do one of several things here:
+ * We must 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 we have to
+ * figure out what to do next:
+ *
+ * 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;
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 (result) {
- clear_errors = 0;
if (sense_valid && req->sense) {
/*
* SG_IO wants current and deferred errors
memcpy(req->sense, cmd->sense_buffer, len);
req->sense_len = len;
}
- } else
- req->data_len = cmd->resid;
+ if (!sense_deferred)
+ error = -EIO;
+ }
+
+ 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);
+ blk_end_request_all(req, 0);
+
+ scsi_next_command(cmd);
+ return;
+ }
}
- /*
- * 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;
+ BUG_ON(blk_bidi_rq(req)); /* bidi not support for !blk_pc_request yet */
/*
* 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));
-
- 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.
- */
+ SCSI_LOG_HLCOMPLETE(1, printk("%u sectors total, "
+ "%d bytes done.\n",
+ blk_rq_sectors(req), good_bytes));
- /*
- * 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;
+ /*
+ * 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 (!(req->cmd_flags & REQ_QUIET))
+ scsi_print_sense("", cmd);
+ result = 0;
+ /* BLOCK_PC may have set error */
+ error = 0;
}
+
/*
- * 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.
+ * A number of bytes were successfully read. If there
+ * are leftovers and there is some kind of error
+ * (result != 0), retry the rest.
*/
- if (sense_valid && !sense_deferred) {
+ if (scsi_end_request(cmd, error, good_bytes, result == 0) == NULL)
+ return;
+
+ error = -EIO;
+
+ 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;
+ } 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 (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 */
+ scsi_release_buffers(cmd);
+ 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))
+ scsi_requeue_command(q, cmd);
+ else
+ scsi_next_command(cmd);
+ break;
+ case ACTION_REPREP:
+ /* 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;
}
}
-EXPORT_SYMBOL(scsi_io_completion);
+
+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;
+ }
+
+ req->buffer = NULL;
+
+ /*
+ * 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;
+}
/*
* Function: scsi_init_io()
* 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;
+ int error = scsi_init_sgtable(cmd->request, &cmd->sdb, gfp_mask);
+ if (error)
+ goto err_exit;
+
+ if (blk_bidi_rq(cmd->request)) {
+ 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;
+ cmd->request->next_rq->special = bidi_sdb;
+ error = scsi_init_sgtable(cmd->request->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(cmd->request)) {
+ 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))
- return BLKPREP_DEFER;
+ BUG_ON(prot_sdb == NULL);
+ ivecs = blk_rq_count_integrity_sg(cmd->request);
- 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(cmd->request,
+ prot_sdb->table.sgl);
+ BUG_ON(unlikely(count > ivecs));
- /*
- * 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);
- scsi_put_command(cmd);
- return BLKPREP_KILL;
+ if (error == BLKPREP_KILL)
+ scsi_put_command(cmd);
+ else /* BLKPREP_DEFER */
+ scsi_unprep_request(cmd->request);
+
+ 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;
-
- if (sdev->sdev_state == SDEV_RUNNING) {
- drv = *(struct scsi_driver **) rq->rq_disk->private_data;
+ struct scsi_cmnd *cmd;
- if (drv->prepare_flush)
- return drv->prepare_flush(q, rq);
+ if (!req->special) {
+ cmd = scsi_get_command(sdev, GFP_ATOMIC);
+ if (unlikely(!cmd))
+ 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;
+
+ 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;
+ int ret = scsi_prep_state_check(sdev, req);
- if (flush_rq->errors) {
- printk("scsi: barrier error, disabling flush support\n");
- blk_queue_ordered(q, QUEUE_ORDERED_NONE);
- }
+ if (ret != BLKPREP_OK)
+ return ret;
+
+ cmd = scsi_get_cmd_from_req(sdev, req);
+ if (unlikely(!cmd))
+ return BLKPREP_DEFER;
+
+ /*
+ * 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;
+
+ 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));
- if (sdev->sdev_state == SDEV_RUNNING) {
- drv = *(struct scsi_driver **) rq->rq_disk->private_data;
- drv->end_flush(q, rq);
+ memset(&cmd->sdb, 0, sizeof(cmd->sdb));
+ req->buffer = NULL;
}
+
+ 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;
+ struct scsi_cmnd *cmd;
+ int ret = scsi_prep_state_check(sdev, req);
- if (sdev->sdev_state != SDEV_RUNNING)
- return -ENXIO;
+ if (ret != BLKPREP_OK)
+ return ret;
- 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)) {
+ 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);
+ cmd = scsi_get_cmd_from_req(sdev, req);
+ if (unlikely(!cmd))
+ return BLKPREP_DEFER;
+
+ 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)
+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:
+ /*
+ * 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;
+}
+EXPORT_SYMBOL(scsi_prep_state_check);
- /*
- * 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)) {
+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);
+ 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 plug here if no returning
+ * command will automatically do that.
*/
- 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_plug_device(q);
+ 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.
- */
- /*
- * This sets up the scatter-gather table (allocating if
- * required).
- */
- ret = scsi_init_io(cmd);
- switch(ret) {
- case BLKPREP_KILL:
- /* BLKPREP_KILL return also releases the command */
- 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;
- }
- }
+ return ret;
+}
+EXPORT_SYMBOL(scsi_prep_return);
- /*
- * The request is now prepped, no need to come back here
- */
- req->flags |= REQ_DONTPREP;
- return BLKPREP_OK;
+int scsi_prep_fn(struct request_queue *q, struct request *req)
+{
+ struct scsi_device *sdev = q->queuedata;
+ int 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;
+ if (req->cmd_type == REQ_TYPE_BLOCK_PC)
+ ret = scsi_setup_blk_pc_cmnd(sdev, req);
+ return scsi_prep_return(q, req, ret);
}
+EXPORT_SYMBOL(scsi_prep_fn);
/*
* scsi_dev_queue_ready: if we can send requests to sdev, return 1 else
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);
return 0;
}
}
- if (sdev->device_blocked)
- return 0;
+ 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)) {
+ if (list_empty(&sdev->starved_entry)) {
+ list_add_tail(&sdev->starved_entry,
+ &shost->starved_list);
+ return 0;
+ }
+ }
+ /* We're OK to process the command, so we can't be starved */
+ if (!list_empty(&sdev->starved_entry))
+ list_del_init(&sdev->starved_entry);
return 1;
}
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;
}
/*
+ * 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
+ * (e.g. !sdev), 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;
+ struct scsi_target *starget;
+
+ if (!sdev)
+ return 0;
+
+ shost = sdev->host;
+ starget = scsi_target(sdev);
+
+ if (scsi_host_in_recovery(shost) || scsi_host_is_busy(shost) ||
+ scsi_target_is_busy(starget) || 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__);
+ __func__);
BUG();
}
+ 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);
+
+ /*
+ * Set the serial numbers back to zero
+ */
+ cmd->serial_number = 0;
+
+ 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);
+ }
}
/*
if (!sdev) {
printk("scsi: killing requests for dead queue\n");
- while ((req = elv_next_request(q)) != NULL)
+ while ((req = blk_peek_request(q)) != NULL)
scsi_kill_request(req, q);
return;
}
* 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;
}
* 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);
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++;
/*
}
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->shost_gendev.parent;
- 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_hw_segments(q, shost->sg_tablesize);
- blk_queue_max_phys_segments(q, SCSI_MAX_PHYS_SEGMENTS);
+ blk_queue_max_phys_segments(q, SCSI_MAX_SG_CHAIN_SEGMENTS);
+
blk_queue_max_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));
+
+ /* New queue, no concurrency on queue_flags */
+ if (!shost->use_clustering)
+ queue_flag_clear_unlocked(QUEUE_FLAG_CLUSTER, q);
/*
- * 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);
+
+struct request_queue *scsi_alloc_queue(struct scsi_device *sdev)
+{
+ 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_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;
}
{
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_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.
+ * 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
* @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;
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
}
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];
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, a return of NOT_READY or UNIT_ATTENTION is
+ * translated to success, with the ->changed flag updated.
+ **/
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)
+ /* could not allocate sense buffer, so can't process it */
+ return result;
+
+ if (sdev->removable && scsi_sense_valid(sshdr) &&
+ (sshdr->sense_key == UNIT_ATTENTION ||
+ sshdr->sense_key == NOT_READY)) {
+ sdev->changed = 1;
+ result = 0;
}
+ 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)
{
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_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;
switch (oldstate) {
case SDEV_CREATED:
case SDEV_RUNNING:
+ case SDEV_QUIESCE:
case SDEV_OFFLINE:
case SDEV_BLOCK:
break;
case SDEV_DEL:
switch (oldstate) {
+ case SDEV_CREATED:
+ case SDEV_RUNNING:
+ case SDEV_OFFLINE:
case SDEV_CANCEL:
break;
default:
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;
+
+ 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;
+ LIST_HEAD(event_list);
+
+ sdev = container_of(work, struct scsi_device, event_work);
+
+ 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:
+ 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.
*
* 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)
{
* queues.
*
* Must be called with user context, may sleep.
- **/
+ */
void
scsi_device_resume(struct scsi_device *sdev)
{
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
* 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
* (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.
- **/
+ */
int
scsi_internal_device_unblock(struct scsi_device *sdev)
{
- 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.
*/
- err = scsi_device_set_state(sdev, SDEV_RUNNING);
- if (err)
- return err;
+ if (sdev->sdev_state == SDEV_BLOCK)
+ sdev->sdev_state = SDEV_RUNNING;
+ else if (sdev->sdev_state == SDEV_CREATED_BLOCK)
+ sdev->sdev_state = SDEV_CREATED;
+ else
+ return -EINVAL;
spin_lock_irqsave(q->queue_lock, flags);
blk_start_queue(q);
device_for_each_child(dev, NULL, 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, KM_BIO_SRC_IRQ);
+}
+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, KM_BIO_SRC_IRQ);
+}
+EXPORT_SYMBOL(scsi_kunmap_atomic_sg);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff