* set defaults
*/
q->nr_requests = BLKDEV_MAX_RQ;
- q->max_phys_segments = MAX_PHYS_SEGMENTS;
- q->max_hw_segments = MAX_HW_SEGMENTS;
+ blk_queue_max_phys_segments(q, MAX_PHYS_SEGMENTS);
+ blk_queue_max_hw_segments(q, MAX_HW_SEGMENTS);
q->make_request_fn = mfn;
q->backing_dev_info.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
q->backing_dev_info.state = 0;
rq->special = NULL;
rq->data_len = 0;
rq->data = NULL;
+ rq->nr_phys_segments = 0;
rq->sense = NULL;
rq->end_io = NULL;
rq->end_io_data = NULL;
/**
* blk_rq_map_user - map user data to a request, for REQ_BLOCK_PC usage
* @q: request queue where request should be inserted
- * @rw: READ or WRITE data
+ * @rq: request structure to fill
* @ubuf: the user buffer
* @len: length of user data
*
* original bio must be passed back in to blk_rq_unmap_user() for proper
* unmapping.
*/
-struct request *blk_rq_map_user(request_queue_t *q, int rw, void __user *ubuf,
- unsigned int len)
+int blk_rq_map_user(request_queue_t *q, struct request *rq, void __user *ubuf,
+ unsigned int len)
{
unsigned long uaddr;
- struct request *rq;
struct bio *bio;
+ int reading;
if (len > (q->max_sectors << 9))
- return ERR_PTR(-EINVAL);
- if ((!len && ubuf) || (len && !ubuf))
- return ERR_PTR(-EINVAL);
+ return -EINVAL;
+ if (!len || !ubuf)
+ return -EINVAL;
- rq = blk_get_request(q, rw, __GFP_WAIT);
- if (!rq)
- return ERR_PTR(-ENOMEM);
+ reading = rq_data_dir(rq) == READ;
/*
* if alignment requirement is satisfied, map in user pages for
*/
uaddr = (unsigned long) ubuf;
if (!(uaddr & queue_dma_alignment(q)) && !(len & queue_dma_alignment(q)))
- bio = bio_map_user(q, NULL, uaddr, len, rw == READ);
+ bio = bio_map_user(q, NULL, uaddr, len, reading);
else
- bio = bio_copy_user(q, uaddr, len, rw == READ);
+ bio = bio_copy_user(q, uaddr, len, reading);
if (!IS_ERR(bio)) {
rq->bio = rq->biotail = bio;
rq->buffer = rq->data = NULL;
rq->data_len = len;
- return rq;
+ return 0;
}
/*
* bio is the err-ptr
*/
- blk_put_request(rq);
- return (struct request *) bio;
+ return PTR_ERR(bio);
}
EXPORT_SYMBOL(blk_rq_map_user);
+/**
+ * blk_rq_map_user_iov - map user data to a request, for REQ_BLOCK_PC usage
+ * @q: request queue where request should be inserted
+ * @rq: request to map data to
+ * @iov: pointer to the iovec
+ * @iov_count: number of elements in the iovec
+ *
+ * Description:
+ * Data will be mapped directly for zero copy io, if possible. Otherwise
+ * a kernel bounce buffer is used.
+ *
+ * A matching blk_rq_unmap_user() must be issued at the end of io, while
+ * still in process context.
+ *
+ * Note: The mapped bio may need to be bounced through blk_queue_bounce()
+ * before being submitted to the device, as pages mapped may be out of
+ * reach. It's the callers responsibility to make sure this happens. The
+ * original bio must be passed back in to blk_rq_unmap_user() for proper
+ * unmapping.
+ */
+int blk_rq_map_user_iov(request_queue_t *q, struct request *rq,
+ struct sg_iovec *iov, int iov_count)
+{
+ struct bio *bio;
+
+ if (!iov || iov_count <= 0)
+ return -EINVAL;
+
+ /* we don't allow misaligned data like bio_map_user() does. If the
+ * user is using sg, they're expected to know the alignment constraints
+ * and respect them accordingly */
+ bio = bio_map_user_iov(q, NULL, iov, iov_count, rq_data_dir(rq)== READ);
+ if (IS_ERR(bio))
+ return PTR_ERR(bio);
+
+ rq->bio = rq->biotail = bio;
+ blk_rq_bio_prep(q, rq, bio);
+ rq->buffer = rq->data = NULL;
+ rq->data_len = bio->bi_size;
+ return 0;
+}
+
+EXPORT_SYMBOL(blk_rq_map_user_iov);
+
/**
* blk_rq_unmap_user - unmap a request with user data
- * @rq: request to be unmapped
- * @bio: bio for the request
+ * @bio: bio to be unmapped
* @ulen: length of user buffer
*
* Description:
- * Unmap a request previously mapped by blk_rq_map_user().
+ * Unmap a bio previously mapped by blk_rq_map_user().
*/
-int blk_rq_unmap_user(struct request *rq, struct bio *bio, unsigned int ulen)
+int blk_rq_unmap_user(struct bio *bio, unsigned int ulen)
{
int ret = 0;
ret = bio_uncopy_user(bio);
}
- blk_put_request(rq);
- return ret;
+ return 0;
}
EXPORT_SYMBOL(blk_rq_unmap_user);
+/**
+ * blk_rq_map_kern - map kernel data to a request, for REQ_BLOCK_PC usage
+ * @q: request queue where request should be inserted
+ * @rq: request to fill
+ * @kbuf: the kernel buffer
+ * @len: length of user data
+ * @gfp_mask: memory allocation flags
+ */
+int blk_rq_map_kern(request_queue_t *q, struct request *rq, void *kbuf,
+ unsigned int len, unsigned int gfp_mask)
+{
+ struct bio *bio;
+
+ if (len > (q->max_sectors << 9))
+ return -EINVAL;
+ if (!len || !kbuf)
+ return -EINVAL;
+
+ bio = bio_map_kern(q, kbuf, len, gfp_mask);
+ if (IS_ERR(bio))
+ return PTR_ERR(bio);
+
+ if (rq_data_dir(rq) == WRITE)
+ bio->bi_rw |= (1 << BIO_RW);
+
+ rq->bio = rq->biotail = bio;
+ blk_rq_bio_prep(q, rq, bio);
+
+ rq->buffer = rq->data = NULL;
+ rq->data_len = len;
+ return 0;
+}
+
+EXPORT_SYMBOL(blk_rq_map_kern);
+
+/**
+ * blk_execute_rq_nowait - insert a request into queue for execution
+ * @q: queue to insert the request in
+ * @bd_disk: matching gendisk
+ * @rq: request to insert
+ * @at_head: insert request at head or tail of queue
+ * @done: I/O completion handler
+ *
+ * Description:
+ * Insert a fully prepared request at the back of the io scheduler queue
+ * for execution. Don't wait for completion.
+ */
+void blk_execute_rq_nowait(request_queue_t *q, struct gendisk *bd_disk,
+ struct request *rq, int at_head,
+ void (*done)(struct request *))
+{
+ int where = at_head ? ELEVATOR_INSERT_FRONT : ELEVATOR_INSERT_BACK;
+
+ rq->rq_disk = bd_disk;
+ rq->flags |= REQ_NOMERGE;
+ rq->end_io = done;
+ elv_add_request(q, rq, where, 1);
+ generic_unplug_device(q);
+}
+
/**
* blk_execute_rq - insert a request into queue for execution
* @q: queue to insert the request in
* @bd_disk: matching gendisk
* @rq: request to insert
+ * @at_head: insert request at head or tail of queue
*
* Description:
* Insert a fully prepared request at the back of the io scheduler queue
- * for execution.
+ * for execution and wait for completion.
*/
int blk_execute_rq(request_queue_t *q, struct gendisk *bd_disk,
- struct request *rq)
+ struct request *rq, int at_head)
{
DECLARE_COMPLETION(wait);
char sense[SCSI_SENSE_BUFFERSIZE];
int err = 0;
- rq->rq_disk = bd_disk;
-
/*
* we need an extra reference to the request, so we can look at
* it after io completion
rq->sense_len = 0;
}
- rq->flags |= REQ_NOMERGE;
rq->waiting = &wait;
- rq->end_io = blk_end_sync_rq;
- elv_add_request(q, rq, ELEVATOR_INSERT_BACK, 1);
- generic_unplug_device(q);
+ blk_execute_rq_nowait(q, bd_disk, rq, at_head, blk_end_sync_rq);
wait_for_completion(&wait);
rq->waiting = NULL;
EXPORT_SYMBOL(blkdev_issue_flush);
+/**
+ * blkdev_scsi_issue_flush_fn - issue flush for SCSI devices
+ * @q: device queue
+ * @disk: gendisk
+ * @error_sector: error offset
+ *
+ * Description:
+ * Devices understanding the SCSI command set, can use this function as
+ * a helper for issuing a cache flush. Note: driver is required to store
+ * the error offset (in case of error flushing) in ->sector of struct
+ * request.
+ */
+int blkdev_scsi_issue_flush_fn(request_queue_t *q, struct gendisk *disk,
+ sector_t *error_sector)
+{
+ struct request *rq = blk_get_request(q, WRITE, __GFP_WAIT);
+ int ret;
+
+ rq->flags |= REQ_BLOCK_PC | REQ_SOFTBARRIER;
+ rq->sector = 0;
+ memset(rq->cmd, 0, sizeof(rq->cmd));
+ rq->cmd[0] = 0x35;
+ rq->cmd_len = 12;
+ rq->data = NULL;
+ rq->data_len = 0;
+ rq->timeout = 60 * HZ;
+
+ ret = blk_execute_rq(q, disk, rq, 0);
+
+ if (ret && error_sector)
+ *error_sector = rq->sector;
+
+ blk_put_request(rq);
+ return ret;
+}
+
+EXPORT_SYMBOL(blkdev_scsi_issue_flush_fn);
+
static void drive_stat_acct(struct request *rq, int nr_sectors, int new_io)
{
int rw = rq_data_dir(rq);
git.openpandora.org / pandora-kernel.git / blobdiff