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-rw-r--r--drivers/scsi/scsi_lib.c262
1 files changed, 223 insertions, 39 deletions
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index dc249cb970ea..a7f3f0c84db7 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -63,39 +63,6 @@ static struct scsi_host_sg_pool scsi_sg_pools[] = {
};
#undef SP
-
-/*
- * Function: scsi_insert_special_req()
- *
- * Purpose: Insert pre-formed request into request queue.
- *
- * Arguments: sreq - request that is ready to be queued.
- * at_head - boolean. True if we should insert at head
- * of queue, false if we should insert at tail.
- *
- * Lock status: Assumed that lock is not held upon entry.
- *
- * Returns: Nothing
- *
- * Notes: This function is called from character device and from
- * ioctl types of functions where the caller knows exactly
- * what SCSI command needs to be issued. The idea is that
- * we merely inject the command into the queue (at the head
- * for now), and then call the queue request function to actually
- * process it.
- */
-int scsi_insert_special_req(struct scsi_request *sreq, int at_head)
-{
- /*
- * Because users of this function are apt to reuse requests with no
- * modification, we have to sanitise the request flags here
- */
- sreq->sr_request->flags &= ~REQ_DONTPREP;
- blk_insert_request(sreq->sr_device->request_queue, sreq->sr_request,
- at_head, sreq);
- return 0;
-}
-
static void scsi_run_queue(struct request_queue *q);
/*
@@ -249,8 +216,13 @@ void scsi_do_req(struct scsi_request *sreq, const void *cmnd,
/*
* head injection *required* here otherwise quiesce won't work
+ *
+ * Because users of this function are apt to reuse requests with no
+ * modification, we have to sanitise the request flags here
*/
- scsi_insert_special_req(sreq, 1);
+ sreq->sr_request->flags &= ~REQ_DONTPREP;
+ blk_insert_request(sreq->sr_device->request_queue, sreq->sr_request,
+ 1, sreq);
}
EXPORT_SYMBOL(scsi_do_req);
@@ -287,6 +259,7 @@ int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,
memcpy(req->cmd, cmd, req->cmd_len);
req->sense = sense;
req->sense_len = 0;
+ req->retries = retries;
req->timeout = timeout;
req->flags |= flags | REQ_BLOCK_PC | REQ_SPECIAL | REQ_QUIET;
@@ -327,6 +300,200 @@ int scsi_execute_req(struct scsi_device *sdev, const unsigned char *cmd,
}
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 kmem_cache_t *scsi_io_context_cache;
+
+static void scsi_end_async(struct request *req)
+{
+ 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);
+
+ if (!rq->bio)
+ blk_rq_bio_prep(q, rq, bio);
+ else if (!q->back_merge_fn(q, rq, bio))
+ return -EINVAL;
+ else {
+ rq->biotail->bi_next = bio;
+ rq->biotail = bio;
+ rq->hard_nr_sectors += bio_sectors(bio);
+ rq->nr_sectors = rq->hard_nr_sectors;
+ }
+
+ return 0;
+}
+
+static int scsi_bi_endio(struct bio *bio, unsigned int bytes_done, 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
+ * @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 + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ unsigned int data_len = 0, len, bytes, off;
+ 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;
+
+ while (len > 0) {
+ bytes = min_t(unsigned int, len, PAGE_SIZE - off);
+
+ 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, bio->bi_size, 0);
+ goto free_bios;
+ }
+ bio = NULL;
+ }
+
+ page++;
+ len -= bytes;
+ off = 0;
+ }
+ }
+
+ rq->buffer = rq->data = NULL;
+ rq->data_len = data_len;
+ 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, bio->bi_size, 0);
+ }
+
+ return err;
+}
+
+/**
+ * scsi_execute_async - insert request
+ * @sdev: scsi device
+ * @cmd: scsi command
+ * @data_direction: data direction
+ * @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
+ **/
+int scsi_execute_async(struct scsi_device *sdev, const unsigned char *cmd,
+ 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_alloc(scsi_io_context_cache, gfp);
+ if (!sioc)
+ return DRIVER_ERROR << 24;
+ memset(sioc, 0, sizeof(*sioc));
+
+ req = blk_get_request(sdev->request_queue, write, gfp);
+ if (!req)
+ goto free_sense;
+ req->flags |= REQ_BLOCK_PC | 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 = COMMAND_SIZE(cmd[0]);
+ 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:
+ kfree(sioc);
+ return DRIVER_ERROR << 24;
+}
+EXPORT_SYMBOL_GPL(scsi_execute_async);
+
/*
* Function: scsi_init_cmd_errh()
*
@@ -884,7 +1051,8 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes,
* system where READ CAPACITY failed, we may have read
* past the end of the disk.
*/
- if (cmd->device->use_10_for_rw &&
+ if ((cmd->device->use_10_for_rw &&
+ sshdr.asc == 0x20 && sshdr.ascq == 0x00) &&
(cmd->cmnd[0] == READ_10 ||
cmd->cmnd[0] == WRITE_10)) {
cmd->device->use_10_for_rw = 0;
@@ -1082,10 +1250,16 @@ static int scsi_issue_flush_fn(request_queue_t *q, struct gendisk *disk,
static void scsi_generic_done(struct scsi_cmnd *cmd)
{
BUG_ON(!blk_pc_request(cmd->request));
- scsi_io_completion(cmd, cmd->result == 0 ? cmd->bufflen : 0, 0);
+ /*
+ * 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->bufflen, 0);
}
-void scsi_setup_blk_pc_cmnd(struct scsi_cmnd *cmd, int retries)
+void scsi_setup_blk_pc_cmnd(struct scsi_cmnd *cmd)
{
struct request *req = cmd->request;
@@ -1100,7 +1274,7 @@ void scsi_setup_blk_pc_cmnd(struct scsi_cmnd *cmd, int retries)
cmd->sc_data_direction = DMA_FROM_DEVICE;
cmd->transfersize = req->data_len;
- cmd->allowed = retries;
+ cmd->allowed = req->retries;
cmd->timeout_per_command = req->timeout;
}
EXPORT_SYMBOL_GPL(scsi_setup_blk_pc_cmnd);
@@ -1240,7 +1414,7 @@ static int scsi_prep_fn(struct request_queue *q, struct request *req)
goto kill;
}
} else {
- scsi_setup_blk_pc_cmnd(cmd, 3);
+ scsi_setup_blk_pc_cmnd(cmd);
cmd->done = scsi_generic_done;
}
}
@@ -1603,6 +1777,14 @@ int __init scsi_init_queue(void)
{
int i;
+ scsi_io_context_cache = kmem_cache_create("scsi_io_context",
+ sizeof(struct scsi_io_context),
+ 0, 0, NULL, NULL);
+ if (!scsi_io_context_cache) {
+ printk(KERN_ERR "SCSI: can't init scsi io context cache\n");
+ return -ENOMEM;
+ }
+
for (i = 0; i < SG_MEMPOOL_NR; i++) {
struct scsi_host_sg_pool *sgp = scsi_sg_pools + i;
int size = sgp->size * sizeof(struct scatterlist);
@@ -1630,6 +1812,8 @@ void scsi_exit_queue(void)
{
int i;
+ kmem_cache_destroy(scsi_io_context_cache);
+
for (i = 0; i < SG_MEMPOOL_NR; i++) {
struct scsi_host_sg_pool *sgp = scsi_sg_pools + i;
mempool_destroy(sgp->pool);
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