]> pilppa.org Git - linux-2.6-omap-h63xx.git/blobdiff - drivers/scsi/scsi_lib.c
[SCSI] Fix st oops with new scsi_execute infrastructure
[linux-2.6-omap-h63xx.git] / drivers / scsi / scsi_lib.c
index ce9d73a292e2a0f273992efd56e7cb7370f2bbc0..14ad2a785a34d142d5585336bcdd58c54136697e 100644 (file)
@@ -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;
@@ -1082,7 +1250,13 @@ 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);
 }
 
 static int scsi_prep_fn(struct request_queue *q, struct request *req)
@@ -1230,7 +1404,7 @@ static int scsi_prep_fn(struct request_queue *q, struct request *req)
                                cmd->sc_data_direction = DMA_NONE;
                        
                        cmd->transfersize = req->data_len;
-                       cmd->allowed = 3;
+                       cmd->allowed = req->retries;
                        cmd->timeout_per_command = req->timeout;
                        cmd->done = scsi_generic_done;
                }
@@ -1594,6 +1768,14 @@ 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);
@@ -1621,6 +1803,8 @@ 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);