pktcdvd: use BIO list management functions

Now that the bio list management stuff is generic, convert pktcdvd to
use bio lists instead of its own private bio list implementation.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Acked-by: Peter Osterlund <petero2@telia.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

2 files changed, 25 insertions, 74 deletions

diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index 68b5957f107c..7cd2973ebb7b 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -569,6 +569,7 @@ static struct packet_data *pkt_alloc_packet_data(int frames)
         }
 
         spin_lock_init(&pkt->lock);
+        bio_list_init(&pkt->orig_bios);
 
         for (i = 0; i < frames; i++) {
                 struct bio *bio = pkt_bio_alloc(1);
@@ -721,43 +722,6 @@ static void pkt_rbtree_insert(struct pktcdvd_device *pd, struct pkt_rb_node *nod
 }
 
 /*
- * Add a bio to a single linked list defined by its head and tail pointers.
- */
-static void pkt_add_list_last(struct bio *bio, struct bio **list_head, struct bio **list_tail)
-{
-        bio->bi_next = NULL;
-        if (*list_tail) {
-                BUG_ON((*list_head) == NULL);
-                (*list_tail)->bi_next = bio;
-                (*list_tail) = bio;
-        } else {
-                BUG_ON((*list_head) != NULL);
-                (*list_head) = bio;
-                (*list_tail) = bio;
-        }
-}
-
-/*
- * Remove and return the first bio from a single linked list defined by its
- * head and tail pointers.
- */
-static inline struct bio *pkt_get_list_first(struct bio **list_head, struct bio **list_tail)
-{
-        struct bio *bio;
-
-        if (*list_head == NULL)
-                return NULL;
-
-        bio = *list_head;
-        *list_head = bio->bi_next;
-        if (*list_head == NULL)
-                *list_tail = NULL;
-
-        bio->bi_next = NULL;
-        return bio;
-}
-
-/*
  * Send a packet_command to the underlying block device and
  * wait for completion.
  */
@@ -876,13 +840,10 @@ static noinline_for_stack int pkt_set_speed(struct pktcdvd_device *pd,
 static void pkt_queue_bio(struct pktcdvd_device *pd, struct bio *bio)
 {
         spin_lock(&pd->iosched.lock);
-        if (bio_data_dir(bio) == READ) {
-                pkt_add_list_last(bio, &pd->iosched.read_queue,
-                                  &pd->iosched.read_queue_tail);
-        } else {
-                pkt_add_list_last(bio, &pd->iosched.write_queue,
-                                  &pd->iosched.write_queue_tail);
-        }
+        if (bio_data_dir(bio) == READ)
+                bio_list_add(&pd->iosched.read_queue, bio);
+        else
+                bio_list_add(&pd->iosched.write_queue, bio);
         spin_unlock(&pd->iosched.lock);
 
         atomic_set(&pd->iosched.attention, 1);
@@ -917,8 +878,8 @@ static void pkt_iosched_process_queue(struct pktcdvd_device *pd)
                 int reads_queued, writes_queued;
 
                 spin_lock(&pd->iosched.lock);
-                reads_queued = (pd->iosched.read_queue != NULL);
-                writes_queued = (pd->iosched.write_queue != NULL);
+                reads_queued = !bio_list_empty(&pd->iosched.read_queue);
+                writes_queued = !bio_list_empty(&pd->iosched.write_queue);
                 spin_unlock(&pd->iosched.lock);
 
                 if (!reads_queued && !writes_queued)
@@ -927,7 +888,7 @@ static void pkt_iosched_process_queue(struct pktcdvd_device *pd)
                 if (pd->iosched.writing) {
                         int need_write_seek = 1;
                         spin_lock(&pd->iosched.lock);
-                        bio = pd->iosched.write_queue;
+                        bio = bio_list_peek(&pd->iosched.write_queue);
                         spin_unlock(&pd->iosched.lock);
                         if (bio && (bio->bi_sector == pd->iosched.last_write))
                                 need_write_seek = 0;
@@ -950,13 +911,10 @@ static void pkt_iosched_process_queue(struct pktcdvd_device *pd)
                 }
 
                 spin_lock(&pd->iosched.lock);
-                if (pd->iosched.writing) {
-                        bio = pkt_get_list_first(&pd->iosched.write_queue,
-                                                 &pd->iosched.write_queue_tail);
-                } else {
-                        bio = pkt_get_list_first(&pd->iosched.read_queue,
-                                                 &pd->iosched.read_queue_tail);
-                }
+                if (pd->iosched.writing)
+                        bio = bio_list_pop(&pd->iosched.write_queue);
+                else
+                        bio = bio_list_pop(&pd->iosched.read_queue);
                 spin_unlock(&pd->iosched.lock);
 
                 if (!bio)
@@ -1114,7 +1072,7 @@ static void pkt_gather_data(struct pktcdvd_device *pd, struct packet_data *pkt)
         int f;
         char written[PACKET_MAX_SIZE];
 
-        BUG_ON(!pkt->orig_bios);
+        BUG_ON(bio_list_empty(&pkt->orig_bios));
 
         atomic_set(&pkt->io_wait, 0);
         atomic_set(&pkt->io_errors, 0);
@@ -1124,7 +1082,7 @@ static void pkt_gather_data(struct pktcdvd_device *pd, struct packet_data *pkt)
          */
         memset(written, 0, sizeof(written));
         spin_lock(&pkt->lock);
-        for (bio = pkt->orig_bios; bio; bio = bio->bi_next) {
+        bio_list_for_each(bio, &pkt->orig_bios) {
                 int first_frame = (bio->bi_sector - pkt->sector) / (CD_FRAMESIZE >> 9);
                 int num_frames = bio->bi_size / CD_FRAMESIZE;
                 pd->stats.secs_w += num_frames * (CD_FRAMESIZE >> 9);
@@ -1363,7 +1321,7 @@ try_next_bio:
                         break;
                 pkt_rbtree_erase(pd, node);
                 spin_lock(&pkt->lock);
-                pkt_add_list_last(bio, &pkt->orig_bios, &pkt->orig_bios_tail);
+                bio_list_add(&pkt->orig_bios, bio);
                 pkt->write_size += bio->bi_size / CD_FRAMESIZE;
                 spin_unlock(&pkt->lock);
         }
@@ -1409,7 +1367,7 @@ static void pkt_start_write(struct pktcdvd_device *pd, struct packet_data *pkt)
          */
         frames_write = 0;
         spin_lock(&pkt->lock);
-        for (bio = pkt->orig_bios; bio; bio = bio->bi_next) {
+        bio_list_for_each(bio, &pkt->orig_bios) {
                 int segment = bio->bi_idx;
                 int src_offs = 0;
                 int first_frame = (bio->bi_sector - pkt->sector) / (CD_FRAMESIZE >> 9);
@@ -1472,20 +1430,14 @@ static void pkt_start_write(struct pktcdvd_device *pd, struct packet_data *pkt)
 
 static void pkt_finish_packet(struct packet_data *pkt, int uptodate)
 {
-        struct bio *bio, *next;
+        struct bio *bio;
 
         if (!uptodate)
                 pkt->cache_valid = 0;
 
         /* Finish all bios corresponding to this packet */
-        bio = pkt->orig_bios;
-        while (bio) {
-                next = bio->bi_next;
-                bio->bi_next = NULL;
+        while ((bio = bio_list_pop(&pkt->orig_bios)))
                 bio_endio(bio, uptodate ? 0 : -EIO);
-                bio = next;
-        }
-        pkt->orig_bios = pkt->orig_bios_tail = NULL;
 }
 
 static void pkt_run_state_machine(struct pktcdvd_device *pd, struct packet_data *pkt)
@@ -2567,8 +2519,7 @@ static int pkt_make_request(struct request_queue *q, struct bio *bio)
                         spin_lock(&pkt->lock);
                         if ((pkt->state == PACKET_WAITING_STATE) ||
                             (pkt->state == PACKET_READ_WAIT_STATE)) {
-                                pkt_add_list_last(bio, &pkt->orig_bios,
-                                                  &pkt->orig_bios_tail);
+                                bio_list_add(&pkt->orig_bios, bio);
                                 pkt->write_size += bio->bi_size / CD_FRAMESIZE;
                                 if ((pkt->write_size >= pkt->frames) &&
                                     (pkt->state == PACKET_WAITING_STATE)) {
@@ -2898,6 +2849,8 @@ static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev)
 
         spin_lock_init(&pd->lock);
         spin_lock_init(&pd->iosched.lock);
+        bio_list_init(&pd->iosched.read_queue);
+        bio_list_init(&pd->iosched.write_queue);
         sprintf(pd->name, DRIVER_NAME"%d", idx);
         init_waitqueue_head(&pd->wqueue);
         pd->bio_queue = RB_ROOT;
diff --git a/include/linux/pktcdvd.h b/include/linux/pktcdvd.h
index 76e5053e1fac..721301b0a908 100644
--- a/include/linux/pktcdvd.h
+++ b/include/linux/pktcdvd.h
@@ -163,10 +163,8 @@ struct packet_iosched
         atomic_t                attention;      /* Set to non-zero when queue processing is needed */
         int                     writing;        /* Non-zero when writing, zero when reading */
         spinlock_t              lock;           /* Protecting read/write queue manipulations */
-        struct bio              *read_queue;
-        struct bio              *read_queue_tail;
-        struct bio              *write_queue;
-        struct bio              *write_queue_tail;
+        struct bio_list         read_queue;
+        struct bio_list         write_queue;
         sector_t                last_write;     /* The sector where the last write ended */
         int                     successive_reads;
 };
@@ -206,8 +204,8 @@ struct packet_data
         spinlock_t              lock;           /* Lock protecting state transitions and */
                                                 /* orig_bios list */
 
-        struct bio              *orig_bios;     /* Original bios passed to pkt_make_request */
-        struct bio              *orig_bios_tail;/* that will be handled by this packet */
+        struct bio_list         orig_bios;      /* Original bios passed to pkt_make_request */
+                                                /* that will be handled by this packet */
         int                     write_size;     /* Total size of all bios in the orig_bios */
                                                 /* list, measured in number of frames */