Add 'discard' request handling

[linux-2.6-omap-h63xx.git] / block / blk-core.c

diff --git a/block/blk-core.c b/block/blk-core.c
index a496727df7ef4b1b4016f961d6350e279677afc9..1e143c4f9d34eb02a6365dda4ed31773dd7a3c26 100644 (file)
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1079,6 +1079,10 @@ void init_request_from_bio(struct request *req, struct bio *bio)
         */
        if (unlikely(bio_barrier(bio)))
                req->cmd_flags |= (REQ_HARDBARRIER | REQ_NOMERGE);
+       if (unlikely(bio_discard(bio))) {
+               req->cmd_flags |= (REQ_SOFTBARRIER | REQ_DISCARD);
+               req->q->prepare_discard_fn(req->q, req);
+       }
 
        if (bio_sync(bio))
                req->cmd_flags |= REQ_RW_SYNC;
@@ -1095,7 +1099,7 @@ void init_request_from_bio(struct request *req, struct bio *bio)
 static int __make_request(struct request_queue *q, struct bio *bio)
 {
        struct request *req;
-       int el_ret, nr_sectors, barrier, err;
+       int el_ret, nr_sectors, barrier, discard, err;
        const unsigned short prio = bio_prio(bio);
        const int sync = bio_sync(bio);
        int rw_flags;
@@ -1115,6 +1119,12 @@ static int __make_request(struct request_queue *q, struct bio *bio)
                goto end_io;
        }
 
+       discard = bio_discard(bio);
+       if (unlikely(discard) && !q->prepare_discard_fn) {
+               err = -EOPNOTSUPP;
+               goto end_io;
+       }
+
        spin_lock_irq(q->queue_lock);
 
        if (unlikely(barrier) || elv_queue_empty(q))
@@ -1405,7 +1415,8 @@ end_io:
 
                if (bio_check_eod(bio, nr_sectors))
                        goto end_io;
-               if (bio_empty_barrier(bio) && !q->prepare_flush_fn) {
+               if ((bio_empty_barrier(bio) && !q->prepare_flush_fn) ||
+                   (bio_discard(bio) && !q->prepare_discard_fn)) {
                        err = -EOPNOTSUPP;
                        goto end_io;
                }
@@ -1487,7 +1498,6 @@ void submit_bio(int rw, struct bio *bio)
         * go through the normal accounting stuff before submission.
         */
        if (bio_has_data(bio)) {
-
                if (rw & WRITE) {
                        count_vm_events(PGPGOUT, count);
                } else {
@@ -1881,7 +1891,7 @@ static int blk_end_io(struct request *rq, int error, unsigned int nr_bytes,
        struct request_queue *q = rq->q;
        unsigned long flags = 0UL;
 
-       if (bio_has_data(rq->bio)) {
+       if (bio_has_data(rq->bio) || blk_discard_rq(rq)) {
                if (__end_that_request_first(rq, error, nr_bytes))
                        return 1;
 
@@ -1939,7 +1949,7 @@ EXPORT_SYMBOL_GPL(blk_end_request);
  **/
 int __blk_end_request(struct request *rq, int error, unsigned int nr_bytes)
 {
-       if (bio_has_data(rq->bio) &&
+       if ((bio_has_data(rq->bio) || blk_discard_rq(rq)) &&
            __end_that_request_first(rq, error, nr_bytes))
                return 1;
 
@@ -2012,12 +2022,14 @@ void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
           we want BIO_RW_AHEAD (bit 1) to imply REQ_FAILFAST (bit 1). */
        rq->cmd_flags |= (bio->bi_rw & 3);
 
-       rq->nr_phys_segments = bio_phys_segments(q, bio);
-       rq->nr_hw_segments = bio_hw_segments(q, bio);
+       if (bio_has_data(bio)) {
+               rq->nr_phys_segments = bio_phys_segments(q, bio);
+               rq->nr_hw_segments = bio_hw_segments(q, bio);
+               rq->buffer = bio_data(bio);
+       }
        rq->current_nr_sectors = bio_cur_sectors(bio);
        rq->hard_cur_sectors = rq->current_nr_sectors;
        rq->hard_nr_sectors = rq->nr_sectors = bio_sectors(bio);
-       rq->buffer = bio_data(bio);
        rq->data_len = bio->bi_size;
 
        rq->bio = rq->biotail = bio;