*/
#include <linux/bio.h>
+#include <linux/bitops.h>
#include <linux/blkdev.h>
#include <linux/completion.h>
#include <linux/kernel.h>
#define SG_MEMPOOL_NR ARRAY_SIZE(scsi_sg_pools)
#define SG_MEMPOOL_SIZE 2
-/*
- * The maximum number of SG segments that we will put inside a scatterlist
- * (unless chaining is used). Should ideally fit inside a single page, to
- * avoid a higher order allocation.
- */
-#define SCSI_MAX_SG_SEGMENTS 128
-
struct scsi_host_sg_pool {
size_t size;
char *name;
mempool_t *pool;
};
-#define SP(x) { x, "sgpool-" #x }
+#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
static struct scsi_host_sg_pool scsi_sg_pools[] = {
SP(8),
SP(16),
-#if (SCSI_MAX_SG_SEGMENTS > 16)
- SP(32),
#if (SCSI_MAX_SG_SEGMENTS > 32)
- SP(64),
+ SP(32),
#if (SCSI_MAX_SG_SEGMENTS > 64)
+ SP(64),
+#if (SCSI_MAX_SG_SEGMENTS > 128)
SP(128),
+#if (SCSI_MAX_SG_SEGMENTS > 256)
+#error SCSI_MAX_SG_SEGMENTS is too large (256 MAX)
#endif
#endif
#endif
+#endif
+ SP(SCSI_MAX_SG_SEGMENTS)
};
#undef SP
+struct kmem_cache *scsi_sdb_cache;
+
static void scsi_run_queue(struct request_queue *q);
/*
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
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);
*/
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;
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;
- data_len += len;
-
- 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()
*
static void scsi_init_cmd_errh(struct scsi_cmnd *cmd)
{
cmd->serial_number = 0;
- cmd->resid = 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]);
+ 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_eh_scheduled)))
scsi_eh_wakeup(shost);
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 (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;
+ }
+ spin_unlock(shost->host_lock);
- if (test_bit(QUEUE_FLAG_REENTER, &q->queue_flags) &&
- !test_and_set_bit(QUEUE_FLAG_REENTER,
- &sdev->request_queue->queue_flags)) {
- blk_run_queue(sdev->request_queue);
- clear_bit(QUEUE_FLAG_REENTER,
- &sdev->request_queue->queue_flags);
- } else
- blk_run_queue(sdev->request_queue);
+ 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_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(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()
*
* 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)
{
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)) {
+ if (blk_end_request(req, error, bytes)) {
int leftover = (req->hard_nr_sectors << 9);
if (blk_pc_request(req))
- leftover = req->data_len;
+ leftover = req->resid_len;
/* 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(req, error, leftover);
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, uptodate);
- 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;
}
-/*
- * Like SCSI_MAX_SG_SEGMENTS, but for archs that have sg chaining. This limit
- * is totally arbitrary, a setting of 2048 will get you at least 8mb ios.
- */
-#define SCSI_MAX_SG_CHAIN_SEGMENTS 2048
-
static inline unsigned int scsi_sgtable_index(unsigned short nents)
{
unsigned int index;
- switch (nents) {
- case 1 ... 8:
+ BUG_ON(nents > SCSI_MAX_SG_SEGMENTS);
+
+ if (nents <= 8)
index = 0;
- break;
- case 9 ... 16:
- index = 1;
- break;
-#if (SCSI_MAX_SG_SEGMENTS > 16)
- case 17 ... 32:
- index = 2;
- break;
-#if (SCSI_MAX_SG_SEGMENTS > 32)
- case 33 ... 64:
- index = 3;
- break;
-#if (SCSI_MAX_SG_SEGMENTS > 64)
- case 65 ... 128:
- index = 4;
- break;
-#endif
-#endif
-#endif
- default:
- printk(KERN_ERR "scsi: bad segment count=%d\n", nents);
- BUG();
- }
+ else
+ index = get_count_order(nents) - 3;
return index;
}
-struct scatterlist *scsi_alloc_sgtable(struct scsi_cmnd *cmd, gfp_t gfp_mask)
+static void scsi_sg_free(struct scatterlist *sgl, unsigned int nents)
{
struct scsi_host_sg_pool *sgp;
- struct scatterlist *sgl, *prev, *ret;
- unsigned int index;
- int this, left;
-
- BUG_ON(!cmd->use_sg);
- left = cmd->use_sg;
- ret = prev = NULL;
- do {
- this = left;
- if (this > SCSI_MAX_SG_SEGMENTS) {
- this = SCSI_MAX_SG_SEGMENTS - 1;
- index = SG_MEMPOOL_NR - 1;
- } else
- index = scsi_sgtable_index(this);
-
- left -= this;
-
- sgp = scsi_sg_pools + index;
-
- sgl = mempool_alloc(sgp->pool, gfp_mask);
- if (unlikely(!sgl))
- goto enomem;
+ sgp = scsi_sg_pools + scsi_sgtable_index(nents);
+ mempool_free(sgl, sgp->pool);
+}
- sg_init_table(sgl, sgp->size);
+static struct scatterlist *scsi_sg_alloc(unsigned int nents, gfp_t gfp_mask)
+{
+ struct scsi_host_sg_pool *sgp;
- /*
- * first loop through, set initial index and return value
- */
- if (!ret)
- ret = sgl;
+ sgp = scsi_sg_pools + scsi_sgtable_index(nents);
+ return mempool_alloc(sgp->pool, gfp_mask);
+}
- /*
- * chain previous sglist, if any. we know the previous
- * sglist must be the biggest one, or we would not have
- * ended up doing another loop.
- */
- if (prev)
- sg_chain(prev, SCSI_MAX_SG_SEGMENTS, sgl);
+static int scsi_alloc_sgtable(struct scsi_data_buffer *sdb, int nents,
+ gfp_t gfp_mask)
+{
+ int ret;
- /*
- * if we have nothing left, mark the last segment as
- * end-of-list
- */
- if (!left)
- sg_mark_end(&sgl[this - 1]);
+ BUG_ON(!nents);
- /*
- * don't allow subsequent mempool allocs to sleep, it would
- * violate the mempool principle.
- */
- gfp_mask &= ~__GFP_WAIT;
- gfp_mask |= __GFP_HIGH;
- prev = sgl;
- } while (left);
+ 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);
- /*
- * ->use_sg may get modified after dma mapping has potentially
- * shrunk the number of segments, so keep a copy of it for free.
- */
- cmd->__use_sg = cmd->use_sg;
return ret;
-enomem:
- if (ret) {
- /*
- * Free entries chained off ret. Since we were trying to
- * allocate another sglist, we know that all entries are of
- * the max size.
- */
- sgp = scsi_sg_pools + SG_MEMPOOL_NR - 1;
- prev = ret;
- ret = &ret[SCSI_MAX_SG_SEGMENTS - 1];
-
- while ((sgl = sg_chain_ptr(ret)) != NULL) {
- ret = &sgl[SCSI_MAX_SG_SEGMENTS - 1];
- mempool_free(sgl, sgp->pool);
- }
-
- mempool_free(prev, sgp->pool);
- }
- return NULL;
}
-EXPORT_SYMBOL(scsi_alloc_sgtable);
-
-void scsi_free_sgtable(struct scsi_cmnd *cmd)
+static void scsi_free_sgtable(struct scsi_data_buffer *sdb)
{
- struct scatterlist *sgl = cmd->request_buffer;
- struct scsi_host_sg_pool *sgp;
-
- /*
- * if this is the biggest size sglist, check if we have
- * chained parts we need to free
- */
- if (cmd->__use_sg > SCSI_MAX_SG_SEGMENTS) {
- unsigned short this, left;
- struct scatterlist *next;
- unsigned int index;
-
- left = cmd->__use_sg - (SCSI_MAX_SG_SEGMENTS - 1);
- next = sg_chain_ptr(&sgl[SCSI_MAX_SG_SEGMENTS - 1]);
- while (left && next) {
- sgl = next;
- this = left;
- if (this > SCSI_MAX_SG_SEGMENTS) {
- this = SCSI_MAX_SG_SEGMENTS - 1;
- index = SG_MEMPOOL_NR - 1;
- } else
- index = scsi_sgtable_index(this);
-
- left -= this;
+ __sg_free_table(&sdb->table, SCSI_MAX_SG_SEGMENTS, scsi_sg_free);
+}
- sgp = scsi_sg_pools + index;
+static void __scsi_release_buffers(struct scsi_cmnd *cmd, int do_bidi_check)
+{
- if (left)
- next = sg_chain_ptr(&sgl[sgp->size - 1]);
+ if (cmd->sdb.table.nents)
+ scsi_free_sgtable(&cmd->sdb);
- mempool_free(sgl, sgp->pool);
- }
+ memset(&cmd->sdb, 0, sizeof(cmd->sdb));
- /*
- * Restore original, will be freed below
- */
- sgl = cmd->request_buffer;
- sgp = scsi_sg_pools + SG_MEMPOOL_NR - 1;
- } else
- sgp = scsi_sg_pools + scsi_sgtable_index(cmd->__use_sg);
+ 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;
+ }
- mempool_free(sgl, sgp->pool);
+ if (scsi_prot_sg_count(cmd))
+ scsi_free_sgtable(cmd->prot_sdb);
}
-EXPORT_SYMBOL(scsi_free_sgtable);
-
/*
* 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)
{
- if (cmd->use_sg)
- scsi_free_sgtable(cmd);
+ __scsi_release_buffers(cmd, 1);
+}
+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->resid_len and req->next_rq->resid_len. The upper-layer driver
+ * can decide what to do with this information.
+ */
+static void scsi_end_bidi_request(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->resid_len = scsi_out(cmd)->resid;
+ req->next_rq->resid_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);
/*
- * Zero these out. They now point to freed memory, and it is
- * dangerous to hang onto the pointers.
+ * This will goose the queue request function at the end, so we don't
+ * need to worry about launching another command.
*/
- cmd->request_buffer = NULL;
- cmd->request_bufflen = 0;
+ scsi_next_command(cmd);
}
/*
* (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)
{
int result = cmd->result;
- int this_count = cmd->request_bufflen;
+ int this_count;
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;
-
- scsi_release_buffers(cmd);
+ 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 (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;
}
+ if (!sense_deferred)
+ error = -EIO;
+ }
+ if (scsi_bidi_cmnd(cmd)) {
+ /* will also release_buffers */
+ scsi_end_bidi_request(cmd);
+ return;
}
- req->data_len = cmd->resid;
+ req->resid_len = scsi_get_resid(cmd);
}
+ 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.
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;
+ /*
+ * 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
+ /*
+ * 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, 1, good_bytes, result == 0) == NULL)
+ 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, 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.
+ * 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);
- return;
- } 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:
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, 0, 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, 0, 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);
}
+ blk_end_request_all(req, -EIO);
+ 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, 0, this_count, !result);
}
-/*
- * Function: scsi_init_io()
- *
- * Purpose: SCSI I/O initialize function.
- *
- * Arguments: cmd - Command descriptor we wish to initialize
- *
- * Returns: 0 on success
- * BLKPREP_DEFER if the failure is retryable
- */
-static int scsi_init_io(struct scsi_cmnd *cmd)
+static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb,
+ gfp_t gfp_mask)
{
- struct request *req = cmd->request;
- int count;
-
- /*
- * 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;
+ int count;
/*
* If sg table allocation fails, requeue request later.
*/
- cmd->request_buffer = scsi_alloc_sgtable(cmd, GFP_ATOMIC);
- if (unlikely(!cmd->request_buffer)) {
- scsi_unprep_request(req);
+ if (unlikely(scsi_alloc_sgtable(sdb, req->nr_phys_segments,
+ gfp_mask))) {
return BLKPREP_DEFER;
}
req->buffer = NULL;
- if (blk_pc_request(req))
- cmd->request_bufflen = req->data_len;
- else
- cmd->request_bufflen = req->nr_sectors << 9;
/*
* 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);
- BUG_ON(count > cmd->use_sg);
- cmd->use_sg = count;
+ 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;
return BLKPREP_OK;
}
+/*
+ * Function: scsi_init_io()
+ *
+ * Purpose: SCSI I/O initialize function.
+ *
+ * Arguments: cmd - Command descriptor we wish to initialize
+ *
+ * Returns: 0 on success
+ * BLKPREP_DEFER if the failure is retryable
+ * BLKPREP_KILL if the failure is fatal
+ */
+int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask)
+{
+ 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;
+ }
+
+ cmd->request->next_rq->special = bidi_sdb;
+ error = scsi_init_sgtable(cmd->request->next_rq, bidi_sdb,
+ GFP_ATOMIC);
+ if (error)
+ goto err_exit;
+ }
+
+ if (blk_integrity_rq(cmd->request)) {
+ struct scsi_data_buffer *prot_sdb = cmd->prot_sdb;
+ int ivecs, count;
+
+ BUG_ON(prot_sdb == NULL);
+ ivecs = blk_rq_count_integrity_sg(cmd->request);
+
+ if (scsi_alloc_sgtable(prot_sdb, ivecs, gfp_mask)) {
+ error = BLKPREP_DEFER;
+ goto err_exit;
+ }
+
+ count = blk_rq_map_integrity_sg(cmd->request,
+ prot_sdb->table.sgl);
+ BUG_ON(unlikely(count > ivecs));
+
+ cmd->prot_sdb = prot_sdb;
+ cmd->prot_sdb->table.nents = count;
+ }
+
+ return BLKPREP_OK ;
+
+err_exit:
+ scsi_release_buffers(cmd);
+ if (error == BLKPREP_KILL)
+ scsi_put_command(cmd);
+ else /* BLKPREP_DEFER */
+ scsi_unprep_request(cmd->request);
+
+ return error;
+}
+EXPORT_SYMBOL(scsi_init_io);
+
static struct scsi_cmnd *scsi_get_cmd_from_req(struct scsi_device *sdev,
struct request *req)
{
cmd->tag = req->tag;
cmd->request = req;
+ cmd->cmnd = req->cmd;
+
return cmd;
}
BUG_ON(!req->nr_phys_segments);
- ret = scsi_init_io(cmd);
+ ret = scsi_init_io(cmd, GFP_ATOMIC);
if (unlikely(ret))
return ret;
} else {
BUG_ON(req->data_len);
- BUG_ON(req->data);
- cmd->request_bufflen = 0;
- cmd->request_buffer = NULL;
- cmd->use_sg = 0;
+ memset(&cmd->sdb, 0, sizeof(cmd->sdb));
req->buffer = NULL;
}
- BUILD_BUG_ON(sizeof(req->cmd) > sizeof(cmd->cmnd));
- memcpy(cmd->cmnd, req->cmd, sizeof(cmd->cmnd));
cmd->cmd_len = req->cmd_len;
if (!req->data_len)
cmd->sc_data_direction = DMA_NONE;
cmd->transfersize = req->data_len;
cmd->allowed = req->retries;
- cmd->timeout_per_command = req->timeout;
return BLKPREP_OK;
}
EXPORT_SYMBOL(scsi_setup_blk_pc_cmnd);
if (ret != BLKPREP_OK)
return ret;
+
+ 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;
+ }
+
/*
* Filesystem requests must transfer data.
*/
if (unlikely(!cmd))
return BLKPREP_DEFER;
- return scsi_init_io(cmd);
+ memset(cmd->cmnd, 0, BLK_MAX_CDB);
+ return scsi_init_io(cmd, GFP_ATOMIC);
}
EXPORT_SYMBOL(scsi_setup_fs_cmnd);
break;
case SDEV_QUIESCE:
case SDEV_BLOCK:
+ case SDEV_CREATED_BLOCK:
/*
* If the devices is blocked we defer normal commands.
*/
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;
}
+
+/*
+ * 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 {
+ blk_plug_device(sdev->request_queue);
+ 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;
+}
+
/*
* scsi_host_queue_ready: if we can send requests to shost, return 1 else
* return 0. We must end up running the queue again whenever 0 is
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, struct request_queue *q)
{
struct scsi_cmnd *cmd = req->special;
struct scsi_device *sdev = cmd->device;
+ struct scsi_target *starget = scsi_target(sdev);
struct Scsi_Host *shost = sdev->host;
blkdev_dequeue_request(req);
if (unlikely(cmd == NULL)) {
printk(KERN_CRIT "impossible request in %s.\n",
- __FUNCTION__);
+ __func__);
BUG();
}
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);
- __scsi_done(cmd);
+ blk_complete_request(req);
}
static void scsi_softirq_done(struct request *rq)
{
- struct scsi_cmnd *cmd = rq->completion_data;
- unsigned long wait_for = (cmd->allowed + 1) * cmd->timeout_per_command;
+ 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)) {
printk(KERN_CRIT "impossible request in %s.\n"
"please mail a stack trace to "
"linux-scsi@vger.kernel.org\n",
- __FUNCTION__);
+ __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 (scsi_target(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++;
/*
request_fn_proc *request_fn)
{
struct request_queue *q;
+ struct device *dev = shost->shost_gendev.parent;
q = blk_init_queue(request_fn, NULL);
if (!q)
* this limit is imposed by hardware restrictions
*/
blk_queue_max_hw_segments(q, shost->sg_tablesize);
-
- /*
- * In the future, sg chaining support will be mandatory and this
- * ifdef can then go away. Right now we don't have all archs
- * converted, so better keep it safe.
- */
-#ifdef ARCH_HAS_SG_CHAIN
- if (shost->use_sg_chaining)
- blk_queue_max_phys_segments(q, SCSI_MAX_SG_CHAIN_SEGMENTS);
- else
- blk_queue_max_phys_segments(q, SCSI_MAX_SG_SEGMENTS);
-#else
- blk_queue_max_phys_segments(q, SCSI_MAX_SG_SEGMENTS);
-#endif
+ 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);
+ 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)
- clear_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags);
+ queue_flag_clear_unlocked(QUEUE_FLAG_CLUSTER, q);
+
+ /*
+ * set a reasonable default alignment on word boundaries: the
+ * host and device may alter it using
+ * blk_queue_update_dma_alignment() later.
+ */
+ blk_queue_dma_alignment(q, 0x03);
+
return q;
}
EXPORT_SYMBOL(__scsi_alloc_queue);
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");
+ 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;
}
if (!sgp->slab) {
printk(KERN_ERR "SCSI: can't init sg slab %s\n",
sgp->name);
+ goto cleanup_sdb;
}
sgp->pool = mempool_create_slab_pool(SG_MEMPOOL_SIZE,
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_io_context_cache);
+ kmem_cache_destroy(scsi_sdb_cache);
for (i = 0; i < SG_MEMPOOL_NR; i++) {
struct scsi_host_sg_pool *sgp = scsi_sg_pools + 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
}
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 (!sshdr_external)
+ sshdr = kzalloc(sizeof(*sshdr), GFP_KERNEL);
+ else
+ sshdr = sshdr_external;
- if ((scsi_sense_valid(&sshdr)) &&
- ((sshdr.sense_key == UNIT_ATTENTION) ||
- (sshdr.sense_key == NOT_READY))) {
+ /* 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);
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;
{
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);
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
* and goose the device queue if successful.
*/
err = scsi_device_set_state(sdev, SDEV_RUNNING);
- if (err)
- return err;
+ if (err) {
+ err = scsi_device_set_state(sdev, SDEV_CREATED);
+
+ if (err)
+ return err;
+ }
spin_lock_irqsave(q->queue_lock, flags);
blk_start_queue(q);
if (unlikely(i == sg_count)) {
printk(KERN_ERR "%s: Bytes in sg: %zu, requested offset %zu, "
"elements %d\n",
- __FUNCTION__, sg_len, *offset, sg_count);
+ __func__, sg_len, *offset, sg_count);
WARN_ON(1);
return NULL;
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff