INIT_LIST_HEAD(&rq->timeout_list);
rq->cpu = -1;
rq->q = q;
- rq->sector = (sector_t) -1;
+ rq->__sector = (sector_t) -1;
INIT_HLIST_NODE(&rq->hash);
RB_CLEAR_NODE(&rq->rb_node);
rq->cmd = rq->__cmd;
EXPORT_SYMBOL(blk_get_request);
/**
+ * blk_make_request - given a bio, allocate a corresponding struct request.
+ *
+ * @bio: The bio describing the memory mappings that will be submitted for IO.
+ * It may be a chained-bio properly constructed by block/bio layer.
+ *
+ * blk_make_request is the parallel of generic_make_request for BLOCK_PC
+ * type commands. Where the struct request needs to be farther initialized by
+ * the caller. It is passed a &struct bio, which describes the memory info of
+ * the I/O transfer.
+ *
+ * The caller of blk_make_request must make sure that bi_io_vec
+ * are set to describe the memory buffers. That bio_data_dir() will return
+ * the needed direction of the request. (And all bio's in the passed bio-chain
+ * are properly set accordingly)
+ *
+ * If called under none-sleepable conditions, mapped bio buffers must not
+ * need bouncing, by calling the appropriate masked or flagged allocator,
+ * suitable for the target device. Otherwise the call to blk_queue_bounce will
+ * BUG.
+ *
+ * WARNING: When allocating/cloning a bio-chain, careful consideration should be
+ * given to how you allocate bios. In particular, you cannot use __GFP_WAIT for
+ * anything but the first bio in the chain. Otherwise you risk waiting for IO
+ * completion of a bio that hasn't been submitted yet, thus resulting in a
+ * deadlock. Alternatively bios should be allocated using bio_kmalloc() instead
+ * of bio_alloc(), as that avoids the mempool deadlock.
+ * If possible a big IO should be split into smaller parts when allocation
+ * fails. Partial allocation should not be an error, or you risk a live-lock.
+ */
+struct request *blk_make_request(struct request_queue *q, struct bio *bio,
+ gfp_t gfp_mask)
+{
+ struct request *rq = blk_get_request(q, bio_data_dir(bio), gfp_mask);
+
+ if (unlikely(!rq))
+ return ERR_PTR(-ENOMEM);
+
+ for_each_bio(bio) {
+ struct bio *bounce_bio = bio;
+ int ret;
+
+ blk_queue_bounce(q, &bounce_bio);
+ ret = blk_rq_append_bio(q, rq, bounce_bio);
+ if (unlikely(ret)) {
+ blk_put_request(rq);
+ return ERR_PTR(ret);
+ }
+ }
+
+ return rq;
+}
+EXPORT_SYMBOL(blk_make_request);
+
+/**
* blk_requeue_request - put a request back on queue
* @q: request queue where request should be inserted
* @rq: request to be inserted
if (blk_rq_tagged(rq))
blk_queue_end_tag(q, rq);
+ BUG_ON(blk_queued_rq(rq));
+
elv_requeue_request(q, rq);
}
EXPORT_SYMBOL(blk_requeue_request);
req->cmd_flags |= REQ_NOIDLE;
req->errors = 0;
- req->sector = bio->bi_sector;
+ req->__sector = bio->bi_sector;
req->ioprio = bio_prio(bio);
blk_rq_bio_prep(req->q, req, bio);
}
req->biotail->bi_next = bio;
req->biotail = bio;
- req->data_len += bytes;
+ req->__data_len += bytes;
req->ioprio = ioprio_best(req->ioprio, prio);
if (!blk_rq_cpu_valid(req))
req->cpu = bio->bi_comp_cpu;
* not touch req->buffer either...
*/
req->buffer = bio_data(bio);
- req->sector = bio->bi_sector;
- req->data_len += bytes;
+ req->__sector = bio->bi_sector;
+ req->__data_len += bytes;
req->ioprio = ioprio_best(req->ioprio, prio);
if (!blk_rq_cpu_valid(req))
req->cpu = bio->bi_comp_cpu;
goto end_io;
}
- if (unlikely(nr_sectors > q->max_hw_sectors)) {
+ if (unlikely(nr_sectors > queue_max_hw_sectors(q))) {
printk(KERN_ERR "bio too big device %s (%u > %u)\n",
- bdevname(bio->bi_bdev, b),
- bio_sectors(bio),
- q->max_hw_sectors);
+ bdevname(bio->bi_bdev, b),
+ bio_sectors(bio),
+ queue_max_hw_sectors(q));
goto end_io;
}
*/
int blk_rq_check_limits(struct request_queue *q, struct request *rq)
{
- if (blk_rq_sectors(rq) > q->max_sectors ||
- blk_rq_bytes(rq) > q->max_hw_sectors << 9) {
+ if (blk_rq_sectors(rq) > queue_max_sectors(q) ||
+ blk_rq_bytes(rq) > queue_max_hw_sectors(q) << 9) {
printk(KERN_ERR "%s: over max size limit.\n", __func__);
return -EIO;
}
* limitation.
*/
blk_recalc_rq_segments(rq);
- if (rq->nr_phys_segments > q->max_phys_segments ||
- rq->nr_phys_segments > q->max_hw_segments) {
+ if (rq->nr_phys_segments > queue_max_phys_segments(q) ||
+ rq->nr_phys_segments > queue_max_hw_segments(q)) {
printk(KERN_ERR "%s: over max segments limit.\n", __func__);
return -EIO;
}
}
EXPORT_SYMBOL_GPL(blk_insert_cloned_request);
-/**
- * blkdev_dequeue_request - dequeue request and start timeout timer
- * @req: request to dequeue
- *
- * Dequeue @req and start timeout timer on it. This hands off the
- * request to the driver.
- *
- * Block internal functions which don't want to start timer should
- * call elv_dequeue_request().
- */
-void blkdev_dequeue_request(struct request *req)
-{
- elv_dequeue_request(req->q, req);
-
- /*
- * We are now handing the request to the hardware, add the
- * timeout handler.
- */
- blk_add_timer(req);
-}
-EXPORT_SYMBOL(blkdev_dequeue_request);
-
static void blk_account_io_completion(struct request *req, unsigned int bytes)
{
if (blk_do_io_stat(req)) {
}
}
-struct request *elv_next_request(struct request_queue *q)
+/**
+ * blk_peek_request - peek at the top of a request queue
+ * @q: request queue to peek at
+ *
+ * Description:
+ * Return the request at the top of @q. The returned request
+ * should be started using blk_start_request() before LLD starts
+ * processing it.
+ *
+ * Return:
+ * Pointer to the request at the top of @q if available. Null
+ * otherwise.
+ *
+ * Context:
+ * queue_lock must be held.
+ */
+struct request *blk_peek_request(struct request_queue *q)
{
struct request *rq;
int ret;
return rq;
}
-EXPORT_SYMBOL(elv_next_request);
+EXPORT_SYMBOL(blk_peek_request);
-void elv_dequeue_request(struct request_queue *q, struct request *rq)
+void blk_dequeue_request(struct request *rq)
{
+ struct request_queue *q = rq->q;
+
BUG_ON(list_empty(&rq->queuelist));
BUG_ON(ELV_ON_HASH(rq));
* the driver side.
*/
if (blk_account_rq(rq))
- q->in_flight++;
+ q->in_flight[rq_is_sync(rq)]++;
}
/**
+ * blk_start_request - start request processing on the driver
+ * @req: request to dequeue
+ *
+ * Description:
+ * Dequeue @req and start timeout timer on it. This hands off the
+ * request to the driver.
+ *
+ * Block internal functions which don't want to start timer should
+ * call blk_dequeue_request().
+ *
+ * Context:
+ * queue_lock must be held.
+ */
+void blk_start_request(struct request *req)
+{
+ blk_dequeue_request(req);
+
+ /*
+ * We are now handing the request to the hardware, initialize
+ * resid_len to full count and add the timeout handler.
+ */
+ req->resid_len = blk_rq_bytes(req);
+ blk_add_timer(req);
+}
+EXPORT_SYMBOL(blk_start_request);
+
+/**
+ * blk_fetch_request - fetch a request from a request queue
+ * @q: request queue to fetch a request from
+ *
+ * Description:
+ * Return the request at the top of @q. The request is started on
+ * return and LLD can start processing it immediately.
+ *
+ * Return:
+ * Pointer to the request at the top of @q if available. Null
+ * otherwise.
+ *
+ * Context:
+ * queue_lock must be held.
+ */
+struct request *blk_fetch_request(struct request_queue *q)
+{
+ struct request *rq;
+
+ rq = blk_peek_request(q);
+ if (rq)
+ blk_start_request(rq);
+ return rq;
+}
+EXPORT_SYMBOL(blk_fetch_request);
+
+/**
* blk_update_request - Special helper function for request stacking drivers
* @rq: the request being processed
* @error: %0 for success, < %0 for error
} else {
int idx = bio->bi_idx + next_idx;
- if (unlikely(bio->bi_idx >= bio->bi_vcnt)) {
+ if (unlikely(idx >= bio->bi_vcnt)) {
blk_dump_rq_flags(req, "__end_that");
printk(KERN_ERR "%s: bio idx %d >= vcnt %d\n",
- __func__, bio->bi_idx, bio->bi_vcnt);
+ __func__, idx, bio->bi_vcnt);
break;
}
* can find how many bytes remain in the request
* later.
*/
- req->data_len = 0;
+ req->__data_len = 0;
return false;
}
bio_iovec(bio)->bv_len -= nr_bytes;
}
- req->data_len -= total_bytes;
+ req->__data_len -= total_bytes;
req->buffer = bio_data(req->bio);
/* update sector only for requests with clear definition of sector */
if (blk_fs_request(req) || blk_discard_rq(req))
- req->sector += total_bytes >> 9;
+ req->__sector += total_bytes >> 9;
/*
* If total number of sectors is less than the first segment
*/
if (blk_rq_bytes(req) < blk_rq_cur_bytes(req)) {
printk(KERN_ERR "blk: request botched\n");
- req->data_len = blk_rq_cur_bytes(req);
+ req->__data_len = blk_rq_cur_bytes(req);
}
/* recalculate the number of segments */
if (blk_rq_tagged(req))
blk_queue_end_tag(req->q, req);
- if (blk_queued_rq(req))
- elv_dequeue_request(req->q, req);
+ BUG_ON(blk_queued_rq(req));
if (unlikely(laptop_mode) && blk_fs_request(req))
laptop_io_completion();
* %false - we are done with this request
* %true - still buffers pending for this request
**/
-bool blk_end_bidi_request(struct request *rq, int error,
- unsigned int nr_bytes, unsigned int bidi_bytes)
+static bool blk_end_bidi_request(struct request *rq, int error,
+ unsigned int nr_bytes, unsigned int bidi_bytes)
{
struct request_queue *q = rq->q;
unsigned long flags;
return false;
}
-EXPORT_SYMBOL_GPL(blk_end_bidi_request);
/**
* __blk_end_bidi_request - Complete a bidi request with queue lock held
* %false - we are done with this request
* %true - still buffers pending for this request
**/
-bool __blk_end_bidi_request(struct request *rq, int error,
- unsigned int nr_bytes, unsigned int bidi_bytes)
+static bool __blk_end_bidi_request(struct request *rq, int error,
+ unsigned int nr_bytes, unsigned int bidi_bytes)
{
if (blk_update_bidi_request(rq, error, nr_bytes, bidi_bytes))
return true;
return false;
}
-EXPORT_SYMBOL_GPL(__blk_end_bidi_request);
+
+/**
+ * blk_end_request - Helper function for drivers to complete the request.
+ * @rq: the request being processed
+ * @error: %0 for success, < %0 for error
+ * @nr_bytes: number of bytes to complete
+ *
+ * Description:
+ * Ends I/O on a number of bytes attached to @rq.
+ * If @rq has leftover, sets it up for the next range of segments.
+ *
+ * Return:
+ * %false - we are done with this request
+ * %true - still buffers pending for this request
+ **/
+bool blk_end_request(struct request *rq, int error, unsigned int nr_bytes)
+{
+ return blk_end_bidi_request(rq, error, nr_bytes, 0);
+}
+EXPORT_SYMBOL_GPL(blk_end_request);
+
+/**
+ * blk_end_request_all - Helper function for drives to finish the request.
+ * @rq: the request to finish
+ * @err: %0 for success, < %0 for error
+ *
+ * Description:
+ * Completely finish @rq.
+ */
+void blk_end_request_all(struct request *rq, int error)
+{
+ bool pending;
+ unsigned int bidi_bytes = 0;
+
+ if (unlikely(blk_bidi_rq(rq)))
+ bidi_bytes = blk_rq_bytes(rq->next_rq);
+
+ pending = blk_end_bidi_request(rq, error, blk_rq_bytes(rq), bidi_bytes);
+ BUG_ON(pending);
+}
+EXPORT_SYMBOL_GPL(blk_end_request_all);
+
+/**
+ * blk_end_request_cur - Helper function to finish the current request chunk.
+ * @rq: the request to finish the current chunk for
+ * @err: %0 for success, < %0 for error
+ *
+ * Description:
+ * Complete the current consecutively mapped chunk from @rq.
+ *
+ * Return:
+ * %false - we are done with this request
+ * %true - still buffers pending for this request
+ */
+bool blk_end_request_cur(struct request *rq, int error)
+{
+ return blk_end_request(rq, error, blk_rq_cur_bytes(rq));
+}
+EXPORT_SYMBOL_GPL(blk_end_request_cur);
+
+/**
+ * __blk_end_request - Helper function for drivers to complete the request.
+ * @rq: the request being processed
+ * @error: %0 for success, < %0 for error
+ * @nr_bytes: number of bytes to complete
+ *
+ * Description:
+ * Must be called with queue lock held unlike blk_end_request().
+ *
+ * Return:
+ * %false - we are done with this request
+ * %true - still buffers pending for this request
+ **/
+bool __blk_end_request(struct request *rq, int error, unsigned int nr_bytes)
+{
+ return __blk_end_bidi_request(rq, error, nr_bytes, 0);
+}
+EXPORT_SYMBOL_GPL(__blk_end_request);
+
+/**
+ * __blk_end_request_all - Helper function for drives to finish the request.
+ * @rq: the request to finish
+ * @err: %0 for success, < %0 for error
+ *
+ * Description:
+ * Completely finish @rq. Must be called with queue lock held.
+ */
+void __blk_end_request_all(struct request *rq, int error)
+{
+ bool pending;
+ unsigned int bidi_bytes = 0;
+
+ if (unlikely(blk_bidi_rq(rq)))
+ bidi_bytes = blk_rq_bytes(rq->next_rq);
+
+ pending = __blk_end_bidi_request(rq, error, blk_rq_bytes(rq), bidi_bytes);
+ BUG_ON(pending);
+}
+EXPORT_SYMBOL_GPL(__blk_end_request_all);
+
+/**
+ * __blk_end_request_cur - Helper function to finish the current request chunk.
+ * @rq: the request to finish the current chunk for
+ * @err: %0 for success, < %0 for error
+ *
+ * Description:
+ * Complete the current consecutively mapped chunk from @rq. Must
+ * be called with queue lock held.
+ *
+ * Return:
+ * %false - we are done with this request
+ * %true - still buffers pending for this request
+ */
+bool __blk_end_request_cur(struct request *rq, int error)
+{
+ return __blk_end_request(rq, error, blk_rq_cur_bytes(rq));
+}
+EXPORT_SYMBOL_GPL(__blk_end_request_cur);
void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
struct bio *bio)
rq->nr_phys_segments = bio_phys_segments(q, bio);
rq->buffer = bio_data(bio);
}
- rq->data_len = bio->bi_size;
+ rq->__data_len = bio->bi_size;
rq->bio = rq->biotail = bio;
if (bio->bi_bdev)
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff