[PATCH] pktcdvd: use BIO list management functions

From: Akinobu Mita
Date: Mon Feb 22 2010 - 08:35:17 EST


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@xxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
---
drivers/block/pktcdvd.c | 89 +++++++++++------------------------------------
include/linux/pktcdvd.h | 10 ++---
2 files changed, 25 insertions(+), 74 deletions(-)

diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index 68b5957..7cd2973 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 76e5053..721301b 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 */

--
1.6.0.6

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