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;
* 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
return 0;
}
+/*
+ * 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.
+ */
+int scsi_queue_insert(struct scsi_cmnd *cmd, int reason)
+{
+ return __scsi_queue_insert(cmd, reason, 1);
+}
/**
* 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 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);
* is invalid. Prevent the garbage from being misinterpreted
* and prevent security leaks by zeroing out the excess data.
*/
- if (unlikely(req->data_len > 0 && req->data_len <= bufflen))
- memset(buffer + (bufflen - req->data_len), 0, req->data_len);
+ 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;
return DRIVER_ERROR << 24;
}
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);
}
EXPORT_SYMBOL(scsi_execute_req);
-struct scsi_io_context {
- void *data;
- void (*done)(void *data, char *sense, int result, int resid);
- char sense[SCSI_SENSE_BUFFERSIZE];
-};
-
-static struct kmem_cache *scsi_io_context_cache;
-
-static void scsi_end_async(struct request *req, int uptodate)
-{
- struct scsi_io_context *sioc = req->end_io_data;
-
- if (sioc->done)
- sioc->done(sioc->data, sioc->sense, req->errors, req->data_len);
-
- kmem_cache_free(scsi_io_context_cache, sioc);
- __blk_put_request(req->q, req);
-}
-
-static int scsi_merge_bio(struct request *rq, struct bio *bio)
-{
- struct request_queue *q = rq->q;
-
- bio->bi_flags &= ~(1 << BIO_SEG_VALID);
- if (rq_data_dir(rq) == WRITE)
- bio->bi_rw |= (1 << BIO_RW);
- blk_queue_bounce(q, &bio);
-
- return blk_rq_append_bio(q, rq, bio);
-}
-
-static void scsi_bi_endio(struct bio *bio, int error)
-{
- bio_put(bio);
-}
-
-/**
- * scsi_req_map_sg - map a scatterlist into a request
- * @rq: request to fill
- * @sgl: scatterlist
- * @nsegs: number of elements
- * @bufflen: len of buffer
- * @gfp: memory allocation flags
- *
- * scsi_req_map_sg maps a scatterlist into a request so that the
- * request can be sent to the block layer. We do not trust the scatterlist
- * sent to use, as some ULDs use that struct to only organize the pages.
- */
-static int scsi_req_map_sg(struct request *rq, struct scatterlist *sgl,
- int nsegs, unsigned bufflen, gfp_t gfp)
-{
- struct request_queue *q = rq->q;
- int nr_pages = (bufflen + sgl[0].offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
- unsigned int data_len = bufflen, len, bytes, off;
- struct scatterlist *sg;
- struct page *page;
- struct bio *bio = NULL;
- int i, err, nr_vecs = 0;
-
- for_each_sg(sgl, sg, nsegs, i) {
- page = sg_page(sg);
- off = sg->offset;
- len = sg->length;
-
- while (len > 0 && data_len > 0) {
- /*
- * sg sends a scatterlist that is larger than
- * the data_len it wants transferred for certain
- * IO sizes
- */
- bytes = min_t(unsigned int, len, PAGE_SIZE - off);
- bytes = min(bytes, data_len);
-
- if (!bio) {
- nr_vecs = min_t(int, BIO_MAX_PAGES, nr_pages);
- nr_pages -= nr_vecs;
-
- bio = bio_alloc(gfp, nr_vecs);
- if (!bio) {
- err = -ENOMEM;
- goto free_bios;
- }
- bio->bi_end_io = scsi_bi_endio;
- }
-
- if (bio_add_pc_page(q, bio, page, bytes, off) !=
- bytes) {
- bio_put(bio);
- err = -EINVAL;
- goto free_bios;
- }
-
- if (bio->bi_vcnt >= nr_vecs) {
- err = scsi_merge_bio(rq, bio);
- if (err) {
- bio_endio(bio, 0);
- goto free_bios;
- }
- bio = NULL;
- }
-
- page++;
- len -= bytes;
- data_len -=bytes;
- off = 0;
- }
- }
-
- rq->buffer = rq->data = NULL;
- rq->data_len = bufflen;
- return 0;
-
-free_bios:
- while ((bio = rq->bio) != NULL) {
- rq->bio = bio->bi_next;
- /*
- * call endio instead of bio_put incase it was bounced
- */
- bio_endio(bio, 0);
- }
-
- return err;
-}
-
-/**
- * scsi_execute_async - insert request
- * @sdev: scsi device
- * @cmd: scsi command
- * @cmd_len: length of scsi cdb
- * @data_direction: DMA_TO_DEVICE, DMA_FROM_DEVICE, or DMA_NONE
- * @buffer: data buffer (this can be a kernel buffer or scatterlist)
- * @bufflen: len of buffer
- * @use_sg: if buffer is a scatterlist this is the number of elements
- * @timeout: request timeout in seconds
- * @retries: number of times to retry request
- * @privdata: data passed to done()
- * @done: callback function when done
- * @gfp: memory allocation flags
- */
-int scsi_execute_async(struct scsi_device *sdev, const unsigned char *cmd,
- int cmd_len, int data_direction, void *buffer, unsigned bufflen,
- int use_sg, int timeout, int retries, void *privdata,
- void (*done)(void *, char *, int, int), gfp_t gfp)
-{
- struct request *req;
- struct scsi_io_context *sioc;
- int err = 0;
- int write = (data_direction == DMA_TO_DEVICE);
-
- sioc = kmem_cache_zalloc(scsi_io_context_cache, gfp);
- if (!sioc)
- return DRIVER_ERROR << 24;
-
- req = blk_get_request(sdev->request_queue, write, gfp);
- if (!req)
- goto free_sense;
- req->cmd_type = REQ_TYPE_BLOCK_PC;
- req->cmd_flags |= REQ_QUIET;
-
- if (use_sg)
- err = scsi_req_map_sg(req, buffer, use_sg, bufflen, gfp);
- else if (bufflen)
- err = blk_rq_map_kern(req->q, req, buffer, bufflen, gfp);
-
- if (err)
- goto free_req;
-
- req->cmd_len = cmd_len;
- memset(req->cmd, 0, BLK_MAX_CDB); /* ATAPI hates garbage after CDB */
- memcpy(req->cmd, cmd, req->cmd_len);
- req->sense = sioc->sense;
- req->sense_len = 0;
- req->timeout = timeout;
- req->retries = retries;
- req->end_io_data = sioc;
-
- sioc->data = privdata;
- sioc->done = done;
-
- blk_execute_rq_nowait(req->q, NULL, req, 1, scsi_end_async);
- return 0;
-
-free_req:
- blk_put_request(req);
-free_sense:
- kmem_cache_free(scsi_io_context_cache, sioc);
- return DRIVER_ERROR << 24;
-}
-EXPORT_SYMBOL_GPL(scsi_execute_async);
-
/*
* Function: scsi_init_cmd_errh()
*
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_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()
*
*/
static void scsi_run_queue(struct request_queue *q)
{
- struct scsi_device *starved_head = NULL, *sdev = q->queuedata;
+ struct scsi_device *sdev = q->queuedata;
struct Scsi_Host *shost = sdev->host;
+ LIST_HEAD(starved_list);
unsigned long flags;
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;
/*
* 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);
- /*
- * The *queue_ready functions can add a device back onto the
- * starved list's tail, so we must check for a infinite loop.
- */
- if (sdev == starved_head)
+ if (scsi_host_is_busy(shost))
break;
- if (!starved_head)
- starved_head = sdev;
+ 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;
}
- list_del_init(&sdev->starved_entry);
spin_unlock(shost->host_lock);
spin_lock(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);
scsi_run_queue(sdev->request_queue);
}
+static void __scsi_release_buffers(struct scsi_cmnd *, int);
+
/*
* Function: scsi_end_request()
*
* to queue the remainder of them.
*/
if (blk_end_request(req, error, bytes)) {
- int leftover = (req->hard_nr_sectors << 9);
-
- if (blk_pc_request(req))
- leftover = req->data_len;
-
/* kill remainder if no retrys */
- if (error && blk_noretry_request(req))
- blk_end_request(req, error, 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;
}
* 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;
}
__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.
- *
- * Arguments: cmd - command that we are bailing.
- *
- * Lock status: Assumed that no lock is held upon entry.
- *
- * Returns: Nothing
- *
- * 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.
- */
-void scsi_release_buffers(struct scsi_cmnd *cmd)
+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 (scsi_bidi_cmnd(cmd)) {
+ if (do_bidi_check && scsi_bidi_cmnd(cmd)) {
struct scsi_data_buffer *bidi_sdb =
cmd->request->next_rq->special;
scsi_free_sgtable(bidi_sdb);
if (scsi_prot_sg_count(cmd))
scsi_free_sgtable(cmd->prot_sdb);
}
-EXPORT_SYMBOL(scsi_release_buffers);
/*
- * Bidi commands Must be complete as a whole, both sides at once.
- * If part of the bytes were written and lld returned
- * scsi_in()->resid and/or scsi_out()->resid this information will be left
- * in req->data_len and req->next_rq->data_len. The upper-layer driver can
- * decide what to do with this information.
+ * Function: scsi_release_buffers()
+ *
+ * Purpose: Completion processing for block device I/O requests.
+ *
+ * Arguments: cmd - command that we are bailing.
+ *
+ * Lock status: Assumed that no lock is held upon entry.
+ *
+ * Returns: Nothing
+ *
+ * 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.
*/
-static void scsi_end_bidi_request(struct scsi_cmnd *cmd)
+void scsi_release_buffers(struct scsi_cmnd *cmd)
{
- struct request *req = cmd->request;
- unsigned int dlen = req->data_len;
- unsigned int next_dlen = req->next_rq->data_len;
-
- req->data_len = scsi_out(cmd)->resid;
- req->next_rq->data_len = scsi_in(cmd)->resid;
-
- /* The req and req->next_rq have not been completed */
- BUG_ON(blk_end_bidi_request(req, 0, dlen, next_dlen));
-
- scsi_release_buffers(cmd);
-
- /*
- * 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);
+ __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) 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.
+ * 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.
*
- * b) We can just use scsi_requeue_command() here. This would
- * be used if we just wanted to retry, for example.
+ * 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.
+ *
+ * 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)
{
int result = cmd->result;
- int this_count;
struct request_queue *q = cmd->device->request_queue;
struct request *req = cmd->request;
int error = 0;
struct scsi_sense_hdr sshdr;
int sense_valid = 0;
int sense_deferred = 0;
+ 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_deferred)
error = -EIO;
}
+
+ req->resid_len = scsi_get_resid(cmd);
+
if (scsi_bidi_cmnd(cmd)) {
- /* will also release_buffers */
- scsi_end_bidi_request(cmd);
+ /*
+ * Bidi commands Must be complete as a whole,
+ * both sides at once.
+ */
+ req->next_rq->resid_len = scsi_in(cmd)->resid;
+
+ blk_end_request_all(req, 0);
+
+ scsi_release_buffers(cmd);
+ scsi_next_command(cmd);
return;
}
- req->data_len = scsi_get_resid(cmd);
}
BUG_ON(blk_bidi_rq(req)); /* bidi not support for !blk_pc_request yet */
- scsi_release_buffers(cmd);
/*
* Next deal with any sectors which we were able to correctly
* handle.
*/
- SCSI_LOG_HLCOMPLETE(1, printk("%ld sectors total, "
+ SCSI_LOG_HLCOMPLETE(1, printk("%u sectors total, "
"%d bytes done.\n",
- req->nr_sectors, good_bytes));
+ blk_rq_sectors(req), good_bytes));
- /* A number of bytes were successfully read. If there
+ /*
+ * 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;
+ }
+
+ /*
+ * A number of bytes were successfully read. If there
* are leftovers and there is some kind of error
* (result != 0), retry the rest.
*/
if (scsi_end_request(cmd, error, good_bytes, result == 0) == NULL)
return;
- this_count = blk_rq_bytes(req);
- /* good_bytes = 0, or (inclusive) there were leftovers and
- * result = 0, so scsi_end_request couldn't retry.
- */
- if (sense_valid && !sense_deferred) {
+ 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) {
* and quietly refuse further access.
*/
cmd->device->changed = 1;
- scsi_end_request(cmd, -EIO, 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.
+ * command and see what happens.
*/
- scsi_requeue_command(q, cmd);
- return;
+ action = ACTION_RETRY;
}
break;
case ILLEGAL_REQUEST:
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);
- } else if (sshdr.asc == 0x10) /* DIX */
- scsi_end_request(cmd, -EIO, this_count, 0);
- else
- scsi_end_request(cmd, -EIO, 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 */
- scsi_end_request(cmd, -EIO, this_count, 0);
- return;
+ description = "Target Data Integrity Failure";
+ error = -EILSEQ;
}
break;
case NOT_READY:
case 0x07: /* operation in progress */
case 0x08: /* Long write in progress */
case 0x09: /* self test in progress */
- scsi_requeue_command(q, cmd);
- return;
+ action = ACTION_DELAYED_RETRY;
+ break;
default:
+ description = "Device not ready";
+ action = ACTION_FAIL;
break;
}
+ } else {
+ description = "Device not ready";
+ action = ACTION_FAIL;
}
- if (!(req->cmd_flags & REQ_QUIET))
- scsi_cmd_print_sense_hdr(cmd,
- "Device not ready",
- &sshdr);
-
- scsi_end_request(cmd, -EIO, this_count, 1);
- return;
+ break;
case VOLUME_OVERFLOW:
- if (!(req->cmd_flags & REQ_QUIET)) {
- scmd_printk(KERN_INFO, cmd,
- "Volume overflow, CDB: ");
- __scsi_print_command(cmd->cmnd);
- scsi_print_sense("", cmd);
- }
/* See SSC3rXX or current. */
- scsi_end_request(cmd, -EIO, this_count, 1);
- return;
+ action = ACTION_FAIL;
+ break;
default:
+ description = "Unhandled sense code";
+ action = ACTION_FAIL;
break;
}
+ } else {
+ description = "Unhandled error code";
+ action = ACTION_FAIL;
}
- 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;
- }
- if (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);
}
+ if (blk_end_request_err(req, -EIO))
+ 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.
+ */
+ 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;
}
- scsi_end_request(cmd, -EIO, this_count, !result);
}
static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb,
count = blk_rq_map_sg(req->q, req, sdb->table.sgl);
BUG_ON(count > sdb->table.nents);
sdb->table.nents = count;
- if (blk_pc_request(req))
- sdb->length = req->data_len;
- else
- sdb->length = req->nr_sectors << 9;
+ sdb->length = blk_rq_bytes(req);
return BLKPREP_OK;
}
if (unlikely(ret))
return ret;
} else {
- BUG_ON(req->data_len);
- BUG_ON(req->data);
+ BUG_ON(blk_rq_bytes(req));
memset(&cmd->sdb, 0, sizeof(cmd->sdb));
req->buffer = NULL;
}
cmd->cmd_len = req->cmd_len;
- if (!req->data_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 = req->data_len;
+ cmd->transfersize = blk_rq_bytes(req);
cmd->allowed = req->retries;
return BLKPREP_OK;
}
break;
case BLKPREP_DEFER:
/*
- * If we defer, the elv_next_request() returns NULL, but the
+ * 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.
*/
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
return 0;
}
}
- if (sdev->device_blocked)
+ if (scsi_device_is_busy(sdev))
return 0;
return 1;
if (--starget->target_blocked == 0) {
SCSI_LOG_MLQUEUE(3, starget_printk(KERN_INFO, starget,
"unblocking target at zero depth\n"));
- } else {
- blk_plug_device(sdev->request_queue);
+ } else
return 0;
- }
}
if (scsi_target_is_busy(starget)) {
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, struct request_queue *q)
struct scsi_target *starget = scsi_target(sdev);
struct Scsi_Host *shost = sdev->host;
- blkdev_dequeue_request(req);
+ blk_start_request(req);
if (unlikely(cmd == NULL)) {
printk(KERN_CRIT "impossible request in %s.\n",
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;
* 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);
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_io_context_cache = kmem_cache_create("scsi_io_context",
- sizeof(struct scsi_io_context),
- 0, 0, NULL);
- if (!scsi_io_context_cache) {
- printk(KERN_ERR "SCSI: can't init scsi io context cache\n");
- return -ENOMEM;
- }
-
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");
- goto cleanup_io_context;
+ return -ENOMEM;
}
for (i = 0; i < SG_MEMPOOL_NR; i++) {
kmem_cache_destroy(sgp->slab);
}
kmem_cache_destroy(scsi_sdb_cache);
-cleanup_io_context:
- kmem_cache_destroy(scsi_io_context_cache);
return -ENOMEM;
}
{
int i;
- kmem_cache_destroy(scsi_io_context_cache);
kmem_cache_destroy(scsi_sdb_cache);
for (i = 0; i < SG_MEMPOOL_NR; i++) {
}
ret = scsi_execute_req(sdev, cmd, DMA_TO_DEVICE, real_buffer, len,
- sshdr, timeout, retries);
+ sshdr, timeout, retries, NULL);
kfree(real_buffer);
return ret;
}
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
/* 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);
- } while ((driver_byte(result) & DRIVER_SENSE) &&
- sshdr && sshdr->sense_key == UNIT_ATTENTION &&
- --retries);
+ timeout, retries, NULL);
+ if (sdev->removable && scsi_sense_valid(sshdr) &&
+ sshdr->sense_key == UNIT_ATTENTION)
+ sdev->changed = 1;
+ } 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 ((driver_byte(result) & DRIVER_SENSE) && sdev->removable) {
-
- if ((scsi_sense_valid(sshdr)) &&
- ((sshdr->sense_key == UNIT_ATTENTION) ||
- (sshdr->sense_key == NOT_READY))) {
- sdev->changed = 1;
- result = 0;
- }
+ 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);
scsi_internal_device_unblock(struct scsi_device *sdev)
{
struct request_queue *q = sdev->request_queue;
- int err;
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) {
- err = scsi_device_set_state(sdev, SDEV_CREATED);
-
- 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);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff