dm: move target request nr to dm_target_io

This patch moves target_request_nr from map_info to dm_target_io and
makes it accessible with dm_bio_get_target_request_nr.

This patch is a preparation for the next patch that removes map_info.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index 5e88bc437be0a1f36d5f4af712a17373dc176fb0..b7e179cdc5af906aed485c7f32b0a65e68533032 100644 (file)
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -1682,7 +1682,7 @@ static int snapshot_merge_map(struct dm_target *ti, struct bio *bio,
        chunk_t chunk;
 
        if (bio->bi_rw & REQ_FLUSH) {
-               if (!map_context->target_request_nr)
+               if (!dm_bio_get_target_request_nr(bio))
                        bio->bi_bdev = s->origin->bdev;
                else
                        bio->bi_bdev = s->cow->bdev;

diff --git a/drivers/md/dm-stripe.c b/drivers/md/dm-stripe.c
index e2f876539743feb800022f4b6da23fe776721fac..4e7ba82146c09aabe971a987b8ada71c39fdb40b 100644 (file)
--- a/drivers/md/dm-stripe.c
+++ b/drivers/md/dm-stripe.c
@@ -279,13 +279,13 @@ static int stripe_map(struct dm_target *ti, struct bio *bio,
        unsigned target_request_nr;
 
        if (bio->bi_rw & REQ_FLUSH) {
-               target_request_nr = map_context->target_request_nr;
+               target_request_nr = dm_bio_get_target_request_nr(bio);
                BUG_ON(target_request_nr >= sc->stripes);
                bio->bi_bdev = sc->stripe[target_request_nr].dev->bdev;
                return DM_MAPIO_REMAPPED;
        }
        if (unlikely(bio->bi_rw & REQ_DISCARD)) {
-               target_request_nr = map_context->target_request_nr;
+               target_request_nr = dm_bio_get_target_request_nr(bio);
                BUG_ON(target_request_nr >= sc->stripes);
                return stripe_map_discard(sc, bio, target_request_nr);
        }

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 2765cf2ba0ff1b4da44649948a967af8e1c22f03..5ee580b4f3309e325f78e6a8d5bebeb3aa1d718f 100644 (file)
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1099,6 +1099,7 @@ static struct dm_target_io *alloc_tio(struct clone_info *ci,
        tio->io = ci->io;
        tio->ti = ti;
        memset(&tio->info, 0, sizeof(tio->info));
+       tio->target_request_nr = 0;
 
        return tio;
 }
@@ -1109,7 +1110,7 @@ static void __issue_target_request(struct clone_info *ci, struct dm_target *ti,
        struct dm_target_io *tio = alloc_tio(ci, ti, ci->bio->bi_max_vecs);
        struct bio *clone = &tio->clone;
 
-       tio->info.target_request_nr = request_nr;
+       tio->target_request_nr = request_nr;
 
        /*
         * Discard requests require the bio's inline iovecs be initialized.

diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 6f0e73b4a80de30a92452c6a8b4a92f1eb722e2a..eb96ef6fd8b7a09b8dcaa4325b42da7102734254 100644 (file)
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -23,7 +23,6 @@ typedef enum { STATUSTYPE_INFO, STATUSTYPE_TABLE } status_type_t;
 union map_info {
        void *ptr;
        unsigned long long ll;
-       unsigned target_request_nr;
 };
 
 /*
@@ -193,20 +192,21 @@ struct dm_target {
         * A number of zero-length barrier requests that will be submitted
         * to the target for the purpose of flushing cache.
         *
-        * The request number will be placed in union map_info->target_request_nr.
+        * The request number can be accessed with dm_bio_get_target_request_nr.
         * It is a responsibility of the target driver to remap these requests
         * to the real underlying devices.
         */
        unsigned num_flush_requests;
 
        /*
-        * The number of discard requests that will be submitted to the
-        * target.  map_info->request_nr is used just like num_flush_requests.
+        * The number of discard requests that will be submitted to the target.
+        * The request number can be accessed with dm_bio_get_target_request_nr.
         */
        unsigned num_discard_requests;
 
        /*
         * The number of WRITE SAME requests that will be submitted to the target.
+        * The request number can be accessed with dm_bio_get_target_request_nr.
         */
        unsigned num_write_same_requests;
 
@@ -263,6 +263,7 @@ struct dm_target_io {
        struct dm_io *io;
        struct dm_target *ti;
        union map_info info;
+       unsigned target_request_nr;
        struct bio clone;
 };
 
@@ -276,6 +277,11 @@ static inline struct bio *dm_bio_from_per_bio_data(void *data, size_t data_size)
        return (struct bio *)((char *)data + data_size + offsetof(struct dm_target_io, clone));
 }
 
+static inline unsigned dm_bio_get_target_request_nr(const struct bio *bio)
+{
+       return container_of(bio, struct dm_target_io, clone)->target_request_nr;
+}
+
 int dm_register_target(struct target_type *t);
 void dm_unregister_target(struct target_type *t);