struct delayed_work delay_work;
struct backing_dev_info *backing_dev_info;
- struct disk_devt *disk_devt;
/*
* The queue owner gets to use this for whatever they like.
#define QUEUE_FLAG_FLUSH_NQ 25 /* flush not queueuable */
#define QUEUE_FLAG_DAX 26 /* device supports DAX */
#define QUEUE_FLAG_STATS 27 /* track rq completion times */
-#define QUEUE_FLAG_RESTART 28 /* queue needs restart at completion */
#define QUEUE_FLAG_DEFAULT ((1 << QUEUE_FLAG_IO_STAT) | \
(1 << QUEUE_FLAG_STACKABLE) | \
return true;
}
-static inline bool bio_will_gap(struct request_queue *q, struct bio *prev,
- struct bio *next)
+static inline bool bio_will_gap(struct request_queue *q,
+ struct request *prev_rq,
+ struct bio *prev,
+ struct bio *next)
{
if (bio_has_data(prev) && queue_virt_boundary(q)) {
struct bio_vec pb, nb;
+ /*
+ * don't merge if the 1st bio starts with non-zero
+ * offset, otherwise it is quite difficult to respect
+ * sg gap limit. We work hard to merge a huge number of small
+ * single bios in case of mkfs.
+ */
+ if (prev_rq)
+ bio_get_first_bvec(prev_rq->bio, &pb);
+ else
+ bio_get_first_bvec(prev, &pb);
+ if (pb.bv_offset)
+ return true;
+
+ /*
+ * We don't need to worry about the situation that the
+ * merged segment ends in unaligned virt boundary:
+ *
+ * - if 'pb' ends aligned, the merged segment ends aligned
+ * - if 'pb' ends unaligned, the next bio must include
+ * one single bvec of 'nb', otherwise the 'nb' can't
+ * merge with 'pb'
+ */
bio_get_last_bvec(prev, &pb);
bio_get_first_bvec(next, &nb);
static inline bool req_gap_back_merge(struct request *req, struct bio *bio)
{
- return bio_will_gap(req->q, req->biotail, bio);
+ return bio_will_gap(req->q, req, req->biotail, bio);
}
static inline bool req_gap_front_merge(struct request *req, struct bio *bio)
{
- return bio_will_gap(req->q, bio, req->bio);
+ return bio_will_gap(req->q, NULL, bio, req->bio);
}
int kblockd_schedule_work(struct work_struct *work);