int rw = rq_data_dir(rq);
int cpu;
- if (!blk_fs_request(rq) || !blk_do_io_stat(rq))
+ if (!blk_do_io_stat(rq))
return;
cpu = part_stat_lock();
- part = disk_map_sector_rcu(rq->rq_disk, rq->sector);
+ part = disk_map_sector_rcu(rq->rq_disk, blk_rq_pos(rq));
if (!new_io)
part_stat_inc(cpu, part, merges[rw]);
rq->cmd_len = BLK_MAX_CDB;
rq->tag = -1;
rq->ref_count = 1;
+ rq->start_time = jiffies;
}
EXPORT_SYMBOL(blk_rq_init);
rq->rq_disk ? rq->rq_disk->disk_name : "?", rq->cmd_type,
rq->cmd_flags);
- printk(KERN_INFO " sector %llu, nr/cnr %lu/%u\n",
- (unsigned long long)rq->sector,
- rq->nr_sectors,
- rq->current_nr_sectors);
- printk(KERN_INFO " bio %p, biotail %p, buffer %p, data %p, len %u\n",
+ printk(KERN_INFO " sector %llu, nr/cnr %u/%u\n",
+ (unsigned long long)blk_rq_pos(rq),
+ blk_rq_sectors(rq), blk_rq_cur_sectors(rq));
+ printk(KERN_INFO " bio %p, biotail %p, buffer %p, len %u\n",
rq->bio, rq->biotail,
- rq->buffer, rq->data,
- rq->data_len);
+ rq->buffer, rq->data_len);
if (blk_pc_request(rq)) {
printk(KERN_INFO " cdb: ");
req->errors = 0;
req->hard_sector = req->sector = bio->bi_sector;
req->ioprio = bio_prio(bio);
- req->start_time = jiffies;
blk_rq_bio_prep(req->q, req, bio);
}
*/
int blk_rq_check_limits(struct request_queue *q, struct request *rq)
{
- if (rq->nr_sectors > q->max_sectors ||
+ if (blk_rq_sectors(rq) > q->max_sectors ||
rq->data_len > q->max_hw_sectors << 9) {
printk(KERN_ERR "%s: over max size limit.\n", __func__);
return -EIO;
static void blk_account_io_completion(struct request *req, unsigned int bytes)
{
- if (!blk_do_io_stat(req))
- return;
-
- if (blk_fs_request(req)) {
+ if (blk_do_io_stat(req)) {
const int rw = rq_data_dir(req);
struct hd_struct *part;
int cpu;
cpu = part_stat_lock();
- part = disk_map_sector_rcu(req->rq_disk, req->sector);
+ part = disk_map_sector_rcu(req->rq_disk, blk_rq_pos(req));
part_stat_add(cpu, part, sectors[rw], bytes >> 9);
part_stat_unlock();
}
static void blk_account_io_done(struct request *req)
{
- if (!blk_do_io_stat(req))
- return;
-
/*
* Account IO completion. bar_rq isn't accounted as a normal
* IO on queueing nor completion. Accounting the containing
* request is enough.
*/
- if (blk_fs_request(req) && req != &req->q->bar_rq) {
+ if (blk_do_io_stat(req) && req != &req->q->bar_rq) {
unsigned long duration = jiffies - req->start_time;
const int rw = rq_data_dir(req);
struct hd_struct *part;
int cpu;
cpu = part_stat_lock();
- part = disk_map_sector_rcu(req->rq_disk, req->sector);
+ part = disk_map_sector_rcu(req->rq_disk, blk_rq_pos(req));
part_stat_inc(cpu, part, ios[rw]);
part_stat_add(cpu, part, ticks[rw], duration);
unsigned int blk_rq_bytes(struct request *rq)
{
if (blk_fs_request(rq))
- return rq->hard_nr_sectors << 9;
+ return blk_rq_sectors(rq) << 9;
return rq->data_len;
}
}
EXPORT_SYMBOL_GPL(blk_rq_cur_bytes);
+struct request *elv_next_request(struct request_queue *q)
+{
+ struct request *rq;
+ int ret;
+
+ while ((rq = __elv_next_request(q)) != NULL) {
+ if (!(rq->cmd_flags & REQ_STARTED)) {
+ /*
+ * This is the first time the device driver
+ * sees this request (possibly after
+ * requeueing). Notify IO scheduler.
+ */
+ if (blk_sorted_rq(rq))
+ elv_activate_rq(q, rq);
+
+ /*
+ * just mark as started even if we don't start
+ * it, a request that has been delayed should
+ * not be passed by new incoming requests
+ */
+ rq->cmd_flags |= REQ_STARTED;
+ trace_block_rq_issue(q, rq);
+ }
+
+ if (!q->boundary_rq || q->boundary_rq == rq) {
+ q->end_sector = rq_end_sector(rq);
+ q->boundary_rq = NULL;
+ }
+
+ if (rq->cmd_flags & REQ_DONTPREP)
+ break;
+
+ if (q->dma_drain_size && rq->data_len) {
+ /*
+ * make sure space for the drain appears we
+ * know we can do this because max_hw_segments
+ * has been adjusted to be one fewer than the
+ * device can handle
+ */
+ rq->nr_phys_segments++;
+ }
+
+ if (!q->prep_rq_fn)
+ break;
+
+ ret = q->prep_rq_fn(q, rq);
+ if (ret == BLKPREP_OK) {
+ break;
+ } else if (ret == BLKPREP_DEFER) {
+ /*
+ * the request may have been (partially) prepped.
+ * we need to keep this request in the front to
+ * avoid resource deadlock. REQ_STARTED will
+ * prevent other fs requests from passing this one.
+ */
+ if (q->dma_drain_size && rq->data_len &&
+ !(rq->cmd_flags & REQ_DONTPREP)) {
+ /*
+ * remove the space for the drain we added
+ * so that we don't add it again
+ */
+ --rq->nr_phys_segments;
+ }
+
+ rq = NULL;
+ break;
+ } else if (ret == BLKPREP_KILL) {
+ rq->cmd_flags |= REQ_QUIET;
+ __blk_end_request_all(rq, -EIO);
+ } else {
+ printk(KERN_ERR "%s: bad return=%d\n", __func__, ret);
+ break;
+ }
+ }
+
+ return rq;
+}
+EXPORT_SYMBOL(elv_next_request);
+
+void elv_dequeue_request(struct request_queue *q, struct request *rq)
+{
+ BUG_ON(list_empty(&rq->queuelist));
+ BUG_ON(ELV_ON_HASH(rq));
+
+ list_del_init(&rq->queuelist);
+
+ /*
+ * the time frame between a request being removed from the lists
+ * and to it is freed is accounted as io that is in progress at
+ * the driver side.
+ */
+ if (blk_account_rq(rq))
+ q->in_flight++;
+}
+
/**
- * __end_that_request_first - end I/O on a request
- * @req: the request being processed
+ * blk_update_request - Special helper function for request stacking drivers
+ * @rq: the request being processed
* @error: %0 for success, < %0 for error
- * @nr_bytes: number of bytes to complete
+ * @nr_bytes: number of bytes to complete @rq
*
* Description:
- * Ends I/O on a number of bytes attached to @req, and sets it up
- * for the next range of segments (if any) in the cluster.
+ * Ends I/O on a number of bytes attached to @rq, but doesn't complete
+ * the request structure even if @rq doesn't have leftover.
+ * If @rq has leftover, sets it up for the next range of segments.
+ *
+ * This special helper function is only for request stacking drivers
+ * (e.g. request-based dm) so that they can handle partial completion.
+ * Actual device drivers should use blk_end_request instead.
+ *
+ * Passing the result of blk_rq_bytes() as @nr_bytes guarantees
+ * %false return from this function.
*
* Return:
- * %0 - we are done with this request, call end_that_request_last()
- * %1 - still buffers pending for this request
+ * %false - this request doesn't have any more data
+ * %true - this request has more data
**/
-static int __end_that_request_first(struct request *req, int error,
- int nr_bytes)
+bool blk_update_request(struct request *req, int error, unsigned int nr_bytes)
{
int total_bytes, bio_nbytes, next_idx = 0;
struct bio *bio;
+ if (!req->bio)
+ return false;
+
trace_block_rq_complete(req->q, req);
/*
if (error && (blk_fs_request(req) && !(req->cmd_flags & REQ_QUIET))) {
printk(KERN_ERR "end_request: I/O error, dev %s, sector %llu\n",
req->rq_disk ? req->rq_disk->disk_name : "?",
- (unsigned long long)req->sector);
+ (unsigned long long)blk_rq_pos(req));
}
blk_account_io_completion(req, nr_bytes);
/*
* completely done
*/
- if (!req->bio)
- return 0;
+ if (!req->bio) {
+ /*
+ * Reset counters so that the request stacking driver
+ * can find how many bytes remain in the request
+ * later.
+ */
+ req->nr_sectors = req->hard_nr_sectors = 0;
+ req->current_nr_sectors = req->hard_cur_sectors = 0;
+ return false;
+ }
/*
* if the request wasn't completed, update state
blk_recalc_rq_sectors(req, total_bytes >> 9);
blk_recalc_rq_segments(req);
- return 1;
+ return true;
}
+EXPORT_SYMBOL_GPL(blk_update_request);
-static int end_that_request_data(struct request *rq, int error,
- unsigned int nr_bytes, unsigned int bidi_bytes)
+static bool blk_update_bidi_request(struct request *rq, int error,
+ unsigned int nr_bytes,
+ unsigned int bidi_bytes)
{
- if (rq->bio) {
- if (__end_that_request_first(rq, error, nr_bytes))
- return 1;
+ if (blk_update_request(rq, error, nr_bytes))
+ return true;
- /* Bidi request must be completed as a whole */
- if (blk_bidi_rq(rq) &&
- __end_that_request_first(rq->next_rq, error, bidi_bytes))
- return 1;
- }
+ /* Bidi request must be completed as a whole */
+ if (unlikely(blk_bidi_rq(rq)) &&
+ blk_update_request(rq->next_rq, error, bidi_bytes))
+ return true;
- return 0;
+ add_disk_randomness(rq->rq_disk);
+
+ return false;
}
/*
* queue lock must be held
*/
-static void end_that_request_last(struct request *req, int error)
+static void blk_finish_request(struct request *req, int error)
{
if (blk_rq_tagged(req))
blk_queue_end_tag(req->q, req);
}
/**
- * blk_end_io - Generic end_io function to complete a request.
- * @rq: the request being processed
- * @error: %0 for success, < %0 for error
- * @nr_bytes: number of bytes to complete @rq
- * @bidi_bytes: number of bytes to complete @rq->next_rq
- * @drv_callback: function called between completion of bios in the request
- * and completion of the request.
- * If the callback returns non %0, this helper returns without
- * completion of the request.
+ * blk_end_bidi_request - Complete a bidi request
+ * @rq: the request to complete
+ * @error: %0 for success, < %0 for error
+ * @nr_bytes: number of bytes to complete @rq
+ * @bidi_bytes: number of bytes to complete @rq->next_rq
*
* Description:
* Ends I/O on a number of bytes attached to @rq and @rq->next_rq.
- * If @rq has leftover, sets it up for the next range of segments.
+ * Drivers that supports bidi can safely call this member for any
+ * type of request, bidi or uni. In the later case @bidi_bytes is
+ * just ignored.
*
* Return:
- * %0 - we are done with this request
- * %1 - this request is not freed yet, it still has pending buffers.
+ * %false - we are done with this request
+ * %true - still buffers pending for this request
**/
-static int blk_end_io(struct request *rq, int error, unsigned int nr_bytes,
- unsigned int bidi_bytes,
- int (drv_callback)(struct request *))
+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 = 0UL;
-
- if (end_that_request_data(rq, error, nr_bytes, bidi_bytes))
- return 1;
+ unsigned long flags;
- /* Special feature for tricky drivers */
- if (drv_callback && drv_callback(rq))
- return 1;
-
- add_disk_randomness(rq->rq_disk);
+ if (blk_update_bidi_request(rq, error, nr_bytes, bidi_bytes))
+ return true;
spin_lock_irqsave(q->queue_lock, flags);
- end_that_request_last(rq, error);
+ blk_finish_request(rq, error);
spin_unlock_irqrestore(q->queue_lock, flags);
- return 0;
+ 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:
- * %0 - we are done with this request
- * %1 - still buffers pending for this request
- **/
-int blk_end_request(struct request *rq, int error, unsigned int nr_bytes)
-{
- return blk_end_io(rq, error, nr_bytes, 0, NULL);
-}
-EXPORT_SYMBOL_GPL(blk_end_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:
- * Must be called with queue lock held unlike blk_end_request().
- *
- * Return:
- * %0 - we are done with this request
- * %1 - still buffers pending for this request
- **/
-int __blk_end_request(struct request *rq, int error, unsigned int nr_bytes)
-{
- if (rq->bio && __end_that_request_first(rq, error, nr_bytes))
- return 1;
-
- add_disk_randomness(rq->rq_disk);
-
- end_that_request_last(rq, error);
-
- return 0;
-}
-EXPORT_SYMBOL_GPL(__blk_end_request);
-
-/**
- * blk_end_bidi_request - Helper function for drivers to complete bidi request.
- * @rq: the bidi request being processed
+ * __blk_end_bidi_request - Complete a bidi request with queue lock held
+ * @rq: the request to complete
* @error: %0 for success, < %0 for error
* @nr_bytes: number of bytes to complete @rq
* @bidi_bytes: number of bytes to complete @rq->next_rq
*
* Description:
- * Ends I/O on a number of bytes attached to @rq and @rq->next_rq.
+ * Identical to blk_end_bidi_request() except that queue lock is
+ * assumed to be locked on entry and remains so on return.
*
* Return:
- * %0 - we are done with this request
- * %1 - still buffers pending for this request
+ * %false - we are done with this request
+ * %true - still buffers pending for this request
**/
-int blk_end_bidi_request(struct request *rq, int error, unsigned int nr_bytes,
- unsigned int bidi_bytes)
+bool __blk_end_bidi_request(struct request *rq, int error,
+ unsigned int nr_bytes, unsigned int bidi_bytes)
{
- return blk_end_io(rq, error, nr_bytes, bidi_bytes, NULL);
-}
-EXPORT_SYMBOL_GPL(blk_end_bidi_request);
+ if (blk_update_bidi_request(rq, error, nr_bytes, bidi_bytes))
+ return true;
-/**
- * end_request - end I/O on the current segment of the request
- * @req: the request being processed
- * @uptodate: error value or %0/%1 uptodate flag
- *
- * Description:
- * Ends I/O on the current segment of a request. If that is the only
- * remaining segment, the request is also completed and freed.
- *
- * This is a remnant of how older block drivers handled I/O completions.
- * Modern drivers typically end I/O on the full request in one go, unless
- * they have a residual value to account for. For that case this function
- * isn't really useful, unless the residual just happens to be the
- * full current segment. In other words, don't use this function in new
- * code. Use blk_end_request() or __blk_end_request() to end a request.
- **/
-void end_request(struct request *req, int uptodate)
-{
- int error = 0;
-
- if (uptodate <= 0)
- error = uptodate ? uptodate : -EIO;
-
- __blk_end_request(req, error, req->hard_cur_sectors << 9);
-}
-EXPORT_SYMBOL(end_request);
-
-/**
- * blk_update_request - Special helper function for request stacking drivers
- * @rq: the request being processed
- * @error: %0 for success, < %0 for error
- * @nr_bytes: number of bytes to complete @rq
- *
- * Description:
- * Ends I/O on a number of bytes attached to @rq, but doesn't complete
- * the request structure even if @rq doesn't have leftover.
- * If @rq has leftover, sets it up for the next range of segments.
- *
- * This special helper function is only for request stacking drivers
- * (e.g. request-based dm) so that they can handle partial completion.
- * Actual device drivers should use blk_end_request instead.
- */
-void blk_update_request(struct request *rq, int error, unsigned int nr_bytes)
-{
- if (!end_that_request_data(rq, error, nr_bytes, 0)) {
- /*
- * These members are not updated in end_that_request_data()
- * when all bios are completed.
- * Update them so that the request stacking driver can find
- * how many bytes remain in the request later.
- */
- rq->nr_sectors = rq->hard_nr_sectors = 0;
- rq->current_nr_sectors = rq->hard_cur_sectors = 0;
- }
-}
-EXPORT_SYMBOL_GPL(blk_update_request);
+ blk_finish_request(rq, error);
-/**
- * blk_end_request_callback - Special helper function for tricky drivers
- * @rq: the request being processed
- * @error: %0 for success, < %0 for error
- * @nr_bytes: number of bytes to complete
- * @drv_callback: function called between completion of bios in the request
- * and completion of the request.
- * If the callback returns non %0, this helper returns without
- * completion of the request.
- *
- * 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.
- *
- * This special helper function is used only for existing tricky drivers.
- * (e.g. cdrom_newpc_intr() of ide-cd)
- * This interface will be removed when such drivers are rewritten.
- * Don't use this interface in other places anymore.
- *
- * Return:
- * %0 - we are done with this request
- * %1 - this request is not freed yet.
- * this request still has pending buffers or
- * the driver doesn't want to finish this request yet.
- **/
-int blk_end_request_callback(struct request *rq, int error,
- unsigned int nr_bytes,
- int (drv_callback)(struct request *))
-{
- return blk_end_io(rq, error, nr_bytes, 0, drv_callback);
+ return false;
}
-EXPORT_SYMBOL_GPL(blk_end_request_callback);
+EXPORT_SYMBOL_GPL(__blk_end_bidi_request);
void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
struct bio *bio)
int __init blk_dev_init(void)
{
+ BUILD_BUG_ON(__REQ_NR_BITS > 8 *
+ sizeof(((struct request *)0)->cmd_flags));
+
kblockd_workqueue = create_workqueue("kblockd");
if (!kblockd_workqueue)
panic("Failed to create kblockd\n");
projects / linux-block.git / blobdiff