diff options
Diffstat (limited to 'block/blk-core.c')
| -rw-r--r-- | block/blk-core.c | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/block/blk-core.c b/block/blk-core.c index bb4fce694a60..96aaa3a419a3 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -2244,6 +2244,40 @@ out: EXPORT_SYMBOL(generic_make_request); /** + * direct_make_request - hand a buffer directly to its device driver for I/O + * @bio: The bio describing the location in memory and on the device. + * + * This function behaves like generic_make_request(), but does not protect + * against recursion. Must only be used if the called driver is known + * to not call generic_make_request (or direct_make_request) again from + * its make_request function. (Calling direct_make_request again from + * a workqueue is perfectly fine as that doesn't recurse). + */ +blk_qc_t direct_make_request(struct bio *bio) +{ + struct request_queue *q = bio->bi_disk->queue; + bool nowait = bio->bi_opf & REQ_NOWAIT; + blk_qc_t ret; + + if (!generic_make_request_checks(bio)) + return BLK_QC_T_NONE; + + if (unlikely(blk_queue_enter(q, nowait))) { + if (nowait && !blk_queue_dying(q)) + bio->bi_status = BLK_STS_AGAIN; + else + bio->bi_status = BLK_STS_IOERR; + bio_endio(bio); + return BLK_QC_T_NONE; + } + + ret = q->make_request_fn(q, bio); + blk_queue_exit(q); + return ret; +} +EXPORT_SYMBOL_GPL(direct_make_request); + +/** * submit_bio - submit a bio to the block device layer for I/O * @bio: The &struct bio which describes the I/O * |