*/
#include <linux/bio.h>
+#include <linux/bitops.h>
#include <linux/blkdev.h>
#include <linux/completion.h>
#include <linux/kernel.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>
struct scsi_host_sg_pool {
size_t size;
- char *name;
+ char *name;
struct kmem_cache *slab;
mempool_t *pool;
};
-#if (SCSI_MAX_PHYS_SEGMENTS < 32)
-#error SCSI_MAX_PHYS_SEGMENTS is too small
+#define SP(x) { x, "sgpool-" __stringify(x) }
+#if (SCSI_MAX_SG_SEGMENTS < 32)
+#error SCSI_MAX_SG_SEGMENTS is too small (must be 32 or greater)
#endif
-
-#define SP(x) { x, "sgpool-" #x }
static struct scsi_host_sg_pool scsi_sg_pools[] = {
SP(8),
SP(16),
+#if (SCSI_MAX_SG_SEGMENTS > 32)
SP(32),
-#if (SCSI_MAX_PHYS_SEGMENTS > 32)
+#if (SCSI_MAX_SG_SEGMENTS > 64)
SP(64),
-#if (SCSI_MAX_PHYS_SEGMENTS > 64)
+#if (SCSI_MAX_SG_SEGMENTS > 128)
SP(128),
-#if (SCSI_MAX_PHYS_SEGMENTS > 128)
- SP(256),
-#if (SCSI_MAX_PHYS_SEGMENTS > 256)
-#error SCSI_MAX_PHYS_SEGMENTS is too large
+#if (SCSI_MAX_SG_SEGMENTS > 256)
+#error SCSI_MAX_SG_SEGMENTS is too large (256 MAX)
#endif
#endif
#endif
#endif
-};
+ SP(SCSI_MAX_SG_SEGMENTS)
+};
#undef SP
+struct kmem_cache *scsi_sdb_cache;
+
static void scsi_run_queue(struct request_queue *q);
/*
*
* 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)
*/
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->data_len > 0 && req->data_len <= bufflen))
+ memset(buffer + (bufflen - req->data_len), 0, req->data_len);
+
ret = req->errors;
out:
blk_put_request(req);
bio->bi_rw |= (1 << BIO_RW);
blk_queue_bounce(q, &bio);
- if (!rq->bio)
- blk_rq_bio_prep(q, rq, bio);
- else if (!ll_back_merge_fn(q, rq, bio))
- return -EINVAL;
- else {
- rq->biotail->bi_next = bio;
- rq->biotail = bio;
- }
-
- return 0;
+ return blk_rq_append_bio(q, rq, bio);
}
-static int scsi_bi_endio(struct bio *bio, unsigned int bytes_done, int error)
+static void scsi_bi_endio(struct bio *bio, int error)
{
- if (bio->bi_size)
- return 1;
-
bio_put(bio);
- return 0;
}
/**
* scsi_req_map_sg - map a scatterlist into a request
* @rq: request to fill
- * @sg: scatterlist
+ * @sgl: scatterlist
* @nsegs: number of elements
* @bufflen: len of buffer
* @gfp: memory allocation flags
{
struct request_queue *q = rq->q;
int nr_pages = (bufflen + sgl[0].offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
- unsigned int data_len = 0, len, bytes, off;
+ 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 (i = 0; i < nsegs; i++) {
- page = sgl[i].page;
- off = sgl[i].offset;
- len = sgl[i].length;
- data_len += len;
+ for_each_sg(sgl, sg, nsegs, i) {
+ page = sg_page(sg);
+ off = sg->offset;
+ len = sg->length;
- while (len > 0) {
+ 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);
if (bio->bi_vcnt >= nr_vecs) {
err = scsi_merge_bio(rq, bio);
if (err) {
- bio_endio(bio, bio->bi_size, 0);
+ 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 = data_len;
+ rq->data_len = bufflen;
return 0;
free_bios:
/*
* call endio instead of bio_put incase it was bounced
*/
- bio_endio(bio, bio->bi_size, 0);
+ bio_endio(bio, 0);
}
return err;
* @sdev: scsi device
* @cmd: scsi command
* @cmd_len: length of scsi cdb
- * @data_direction: data direction
+ * @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
- * @flags: or into request flags
- **/
+ * @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,
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]);
+ cmd->cmd_len = scsi_command_size(cmd->cmnd);
}
void scsi_device_unbusy(struct scsi_device *sdev)
struct Scsi_Host *shost = sdev->host;
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);
!shost->host_blocked && !shost->host_self_blocked &&
!((shost->can_queue > 0) &&
(shost->host_busy >= shost->can_queue))) {
+
+ int flagset;
+
/*
* As long as shost is accepting commands and we have
* starved queues, call blk_run_queue. scsi_request_fn
sdev = list_entry(shost->starved_list.next,
struct scsi_device, starved_entry);
list_del_init(&sdev->starved_entry);
- spin_unlock_irqrestore(shost->host_lock, flags);
-
-
- 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_unlock(shost->host_lock);
+
+ 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);
+ spin_lock(shost->host_lock);
if (unlikely(!list_empty(&sdev->starved_entry)))
/*
* sdev lost a race, and was put back on the
* 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)) {
+ 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 (!uptodate && blk_noretry_request(req))
- end_that_request_chunk(req, 0, leftover);
+ if (error && blk_noretry_request(req))
+ blk_end_request(req, error, leftover);
else {
if (requeue) {
/*
}
}
- 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.
return NULL;
}
-struct scatterlist *scsi_alloc_sgtable(struct scsi_cmnd *cmd, gfp_t 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;
}
-EXPORT_SYMBOL(scsi_alloc_sgtable);
+static void scsi_sg_free(struct scatterlist *sgl, unsigned int nents)
+{
+ struct scsi_host_sg_pool *sgp;
-void scsi_free_sgtable(struct scatterlist *sgl, int 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;
- BUG_ON(index >= SG_MEMPOOL_NR);
+ sgp = scsi_sg_pools + scsi_sgtable_index(nents);
+ return mempool_alloc(sgp->pool, gfp_mask);
+}
- sgp = scsi_sg_pools + index;
- mempool_free(sgl, sgp->pool);
+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;
}
-EXPORT_SYMBOL(scsi_free_sgtable);
+static void scsi_free_sgtable(struct scsi_data_buffer *sdb)
+{
+ __sg_free_table(&sdb->table, SCSI_MAX_SG_SEGMENTS, scsi_sg_free);
+}
/*
* Function: scsi_release_buffers()
* 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->sdb.table.nents)
+ scsi_free_sgtable(&cmd->sdb);
+
+ memset(&cmd->sdb, 0, sizeof(cmd->sdb));
+
+ if (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);
+}
+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.
+ */
+static void scsi_end_bidi_request(struct scsi_cmnd *cmd)
{
- if (cmd->use_sg)
- scsi_free_sgtable(cmd->request_buffer, cmd->sglist_len);
+ 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);
/*
- * 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);
}
/*
void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
{
int result = cmd->result;
- int this_count = cmd->request_bufflen;
- request_queue_t *q = cmd->device->request_queue;
+ 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);
-
if (result) {
sense_valid = scsi_command_normalize_sense(cmd, &sshdr);
if (sense_valid)
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;
}
- req->data_len = cmd->resid;
+ if (scsi_bidi_cmnd(cmd)) {
+ /* will also release_buffers */
+ scsi_end_bidi_request(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, "
"%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;
/* 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.
* and quietly refuse further access.
*/
cmd->device->changed = 1;
- scsi_end_request(cmd, 0, this_count, 1);
+ scsi_end_request(cmd, -EIO, this_count, 1);
return;
} else {
/* Must have been a power glitch, or a
* 6-byte command.
*/
scsi_requeue_command(q, cmd);
- return;
- } else {
- scsi_end_request(cmd, 0, this_count, 1);
+ } else if (sshdr.asc == 0x10) /* DIX */
+ scsi_end_request(cmd, -EIO, this_count, 0);
+ else
+ scsi_end_request(cmd, -EIO, this_count, 1);
+ return;
+ case ABORTED_COMMAND:
+ if (sshdr.asc == 0x10) { /* DIF */
+ scsi_end_request(cmd, -EIO, this_count, 0);
return;
}
break;
break;
}
}
- if (!(req->cmd_flags & REQ_QUIET)) {
- scmd_printk(KERN_INFO, cmd,
- "Device not ready: ");
- scsi_print_sense_hdr("", &sshdr);
- }
- scsi_end_request(cmd, 0, this_count, 1);
+ 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;
case VOLUME_OVERFLOW:
if (!(req->cmd_flags & REQ_QUIET)) {
scsi_print_sense("", cmd);
}
/* See SSC3rXX or current. */
- scsi_end_request(cmd, 0, this_count, 1);
+ scsi_end_request(cmd, -EIO, this_count, 1);
return;
default:
break;
scsi_print_sense("", cmd);
}
}
- scsi_end_request(cmd, 0, this_count, !result);
+ scsi_end_request(cmd, -EIO, this_count, !result);
+}
+
+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;
+ if (blk_pc_request(req))
+ sdb->length = req->data_len;
+ else
+ sdb->length = req->nr_sectors << 9;
+ return BLKPREP_OK;
}
-EXPORT_SYMBOL(scsi_io_completion);
/*
* 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;
-
- /*
- * 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 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 sg table allocation fails, requeue request later.
- */
- sgpnt = scsi_alloc_sgtable(cmd, GFP_ATOMIC);
- if (unlikely(!sgpnt)) {
- scsi_unprep_request(req);
- return BLKPREP_DEFER;
+ cmd->request->next_rq->special = bidi_sdb;
+ error = scsi_init_sgtable(cmd->request->next_rq, bidi_sdb,
+ GFP_ATOMIC);
+ if (error)
+ goto err_exit;
}
- req->buffer = NULL;
- cmd->request_buffer = (char *) sgpnt;
- if (blk_pc_request(req))
- cmd->request_bufflen = req->data_len;
- else
- cmd->request_bufflen = req->nr_sectors << 9;
+ if (blk_integrity_rq(cmd->request)) {
+ struct scsi_data_buffer *prot_sdb = cmd->prot_sdb;
+ int ivecs, count;
- /*
- * 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);
- if (likely(count <= cmd->use_sg)) {
- cmd->use_sg = count;
- return BLKPREP_OK;
- }
+ BUG_ON(prot_sdb == NULL);
+ ivecs = blk_rq_count_integrity_sg(cmd->request);
- 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);
+ if (scsi_alloc_sgtable(prot_sdb, ivecs, gfp_mask)) {
+ error = BLKPREP_DEFER;
+ goto err_exit;
+ }
- /* release the command and kill it */
- scsi_release_buffers(cmd);
- scsi_put_command(cmd);
- return BLKPREP_KILL;
-}
+ count = blk_rq_map_integrity_sg(cmd->request,
+ prot_sdb->table.sgl);
+ BUG_ON(unlikely(count > ivecs));
-static int scsi_issue_flush_fn(request_queue_t *q, struct gendisk *disk,
- sector_t *error_sector)
-{
- struct scsi_device *sdev = q->queuedata;
- struct scsi_driver *drv;
+ cmd->prot_sdb = prot_sdb;
+ cmd->prot_sdb->table.nents = count;
+ }
- if (sdev->sdev_state != SDEV_RUNNING)
- return -ENXIO;
+ return BLKPREP_OK ;
- drv = *(struct scsi_driver **) disk->private_data;
- if (drv->issue_flush)
- return drv->issue_flush(&sdev->sdev_gendev, error_sector);
+err_exit:
+ scsi_release_buffers(cmd);
+ if (error == BLKPREP_KILL)
+ scsi_put_command(cmd);
+ else /* BLKPREP_DEFER */
+ scsi_unprep_request(cmd->request);
- return -EOPNOTSUPP;
+ 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;
- return cmd;
-}
+ cmd->cmnd = req->cmd;
-static void scsi_blk_pc_done(struct scsi_cmnd *cmd)
-{
- BUG_ON(!blk_pc_request(cmd->request));
- /*
- * This will complete the whole command with uptodate=1 so
- * as far as the block layer is concerned the command completed
- * successfully. Since this is a REQ_BLOCK_PC command the
- * caller should check the request's errors value
- */
- scsi_io_completion(cmd, cmd->request_bufflen);
+ return cmd;
}
-static int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req)
+int scsi_setup_blk_pc_cmnd(struct scsi_device *sdev, struct request *req)
{
struct scsi_cmnd *cmd;
+ int ret = scsi_prep_state_check(sdev, req);
+
+ if (ret != BLKPREP_OK)
+ return ret;
cmd = scsi_get_cmd_from_req(sdev, req);
if (unlikely(!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;
- cmd->done = scsi_blk_pc_done;
return BLKPREP_OK;
}
+EXPORT_SYMBOL(scsi_setup_blk_pc_cmnd);
/*
* 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.
*/
-static int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req)
+int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req)
{
struct scsi_cmnd *cmd;
- struct scsi_driver *drv;
- int ret;
+ int ret = scsi_prep_state_check(sdev, req);
+
+ 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;
- ret = scsi_init_io(cmd);
- if (unlikely(ret))
- return ret;
-
- /*
- * Initialize the actual SCSI command for this request.
- */
- drv = *(struct scsi_driver **)req->rq_disk->private_data;
- if (unlikely(!drv->init_command(cmd))) {
- scsi_release_buffers(cmd);
- scsi_put_command(cmd);
- return BLKPREP_KILL;
- }
-
- return BLKPREP_OK;
+ 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;
int ret = BLKPREP_OK;
/*
ret = BLKPREP_KILL;
break;
}
-
- if (ret != BLKPREP_OK)
- goto out;
}
+ return ret;
+}
+EXPORT_SYMBOL(scsi_prep_state_check);
- switch (req->cmd_type) {
- case REQ_TYPE_BLOCK_PC:
- ret = scsi_setup_blk_pc_cmnd(sdev, req);
- break;
- case REQ_TYPE_FS:
- ret = scsi_setup_fs_cmnd(sdev, req);
- break;
- default:
- /*
- * All other command types are not supported.
- *
- * Note that these days the SCSI subsystem does not use
- * REQ_TYPE_SPECIAL requests anymore. These are only used
- * (directly or via blk_insert_request) by non-SCSI drivers.
- */
- blk_dump_rq_flags(req, "SCSI bad req");
- ret = BLKPREP_KILL;
- break;
- }
+int scsi_prep_return(struct request_queue *q, struct request *req, int ret)
+{
+ struct scsi_device *sdev = q->queuedata;
- out:
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:
/*
return ret;
}
+EXPORT_SYMBOL(scsi_prep_return);
+
+int scsi_prep_fn(struct request_queue *q, struct request *req)
+{
+ struct scsi_device *sdev = q->queuedata;
+ int ret = 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);
+}
/*
* scsi_dev_queue_ready: if we can send requests to sdev, return 1 else
printk("scsi%d unblocking host at zero depth\n",
shost->host_no));
} else {
- blk_plug_device(q);
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 = cmd->device;
if (unlikely(cmd == NULL)) {
printk(KERN_CRIT "impossible request in %s.\n",
- __FUNCTION__);
+ __func__);
BUG();
}
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);
+ /*
+ * 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_host_queue_ready(q, shost, sdev))
goto not_ready;
- if (sdev->single_lun) {
+ if (scsi_target(sdev)->single_lun) {
if (scsi_target(sdev)->starget_sdev_user &&
scsi_target(sdev)->starget_sdev_user != sdev)
goto not_ready;
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)
return NULL;
+ /*
+ * 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);
+ 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);
return NULL;
blk_queue_prep_rq(q, scsi_prep_fn);
- blk_queue_issue_flush_fn(q, scsi_issue_flush_fn);
blk_queue_softirq_done(q, scsi_softirq_done);
+ blk_queue_rq_timed_out(q, scsi_times_out);
return q;
}
scsi_io_context_cache = kmem_cache_create("scsi_io_context",
sizeof(struct scsi_io_context),
- 0, 0, NULL, NULL);
+ 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;
+ }
+
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_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);
+cleanup_io_context:
+ kmem_cache_destroy(scsi_io_context_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;
* @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 successful; negative error number or scsi
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,
}
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 (!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);
+ } while ((driver_byte(result) & DRIVER_SENSE) &&
+ 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))) {
+ if ((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)
{
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;
* (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;
+ struct request_queue *q = sdev->request_queue;
int err;
unsigned long flags;
/**
* scsi_kmap_atomic_sg - find and atomically map an sg-elemnt
- * @sg: scatter-gather list
+ * @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 *sg, int sg_count,
+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 (i = 0; i < sg_count; i++) {
+ for_each_sg(sgl, sg, sg_count, i) {
len_complete = sg_len; /* Complete sg-entries */
- sg_len += sg[i].length;
+ 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",
- __FUNCTION__, sg_len, *offset, sg_count);
+ __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[i].offset;
+ *offset = *offset - len_complete + sg->offset;
/* Assumption: contiguous pages can be accessed as "page + i" */
- page = nth_page(sg[i].page, (*offset >> PAGE_SHIFT));
+ 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 */
EXPORT_SYMBOL(scsi_kmap_atomic_sg);
/**
- * scsi_kunmap_atomic_sg - atomically unmap a virtual address, previously
- * mapped with 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)
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