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path: root/drivers/block/pktcdvd.c
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Diffstat (limited to 'drivers/block/pktcdvd.c')
-rw-r--r--drivers/block/pktcdvd.c55
1 files changed, 33 insertions, 22 deletions
diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index 1a1fa3ccb91..7b838342f0a 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -467,14 +467,12 @@ static int pkt_set_speed(struct pktcdvd_device *pd, unsigned write_speed, unsign
* Queue a bio for processing by the low-level CD device. Must be called
* from process context.
*/
-static void pkt_queue_bio(struct pktcdvd_device *pd, struct bio *bio, int high_prio_read)
+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);
- if (high_prio_read)
- pd->iosched.high_prio_read = 1;
} else {
pkt_add_list_last(bio, &pd->iosched.write_queue,
&pd->iosched.write_queue_tail);
@@ -490,15 +488,16 @@ static void pkt_queue_bio(struct pktcdvd_device *pd, struct bio *bio, int high_p
* requirements for CDRW drives:
* - A cache flush command must be inserted before a read request if the
* previous request was a write.
- * - Switching between reading and writing is slow, so don't it more often
+ * - Switching between reading and writing is slow, so don't do it more often
* than necessary.
+ * - Optimize for throughput at the expense of latency. This means that streaming
+ * writes will never be interrupted by a read, but if the drive has to seek
+ * before the next write, switch to reading instead if there are any pending
+ * read requests.
* - Set the read speed according to current usage pattern. When only reading
* from the device, it's best to use the highest possible read speed, but
* when switching often between reading and writing, it's better to have the
* same read and write speeds.
- * - Reads originating from user space should have higher priority than reads
- * originating from pkt_gather_data, because some process is usually waiting
- * on reads of the first kind.
*/
static void pkt_iosched_process_queue(struct pktcdvd_device *pd)
{
@@ -512,21 +511,24 @@ static void pkt_iosched_process_queue(struct pktcdvd_device *pd)
for (;;) {
struct bio *bio;
- int reads_queued, writes_queued, high_prio_read;
+ int reads_queued, writes_queued;
spin_lock(&pd->iosched.lock);
reads_queued = (pd->iosched.read_queue != NULL);
writes_queued = (pd->iosched.write_queue != NULL);
- if (!reads_queued)
- pd->iosched.high_prio_read = 0;
- high_prio_read = pd->iosched.high_prio_read;
spin_unlock(&pd->iosched.lock);
if (!reads_queued && !writes_queued)
break;
if (pd->iosched.writing) {
- if (high_prio_read || (!writes_queued && reads_queued)) {
+ int need_write_seek = 1;
+ spin_lock(&pd->iosched.lock);
+ bio = pd->iosched.write_queue;
+ spin_unlock(&pd->iosched.lock);
+ if (bio && (bio->bi_sector == pd->iosched.last_write))
+ need_write_seek = 0;
+ if (need_write_seek && reads_queued) {
if (atomic_read(&pd->cdrw.pending_bios) > 0) {
VPRINTK("pktcdvd: write, waiting\n");
break;
@@ -559,8 +561,10 @@ static void pkt_iosched_process_queue(struct pktcdvd_device *pd)
if (bio_data_dir(bio) == READ)
pd->iosched.successive_reads += bio->bi_size >> 10;
- else
+ else {
pd->iosched.successive_reads = 0;
+ pd->iosched.last_write = bio->bi_sector + bio_sectors(bio);
+ }
if (pd->iosched.successive_reads >= HI_SPEED_SWITCH) {
if (pd->read_speed == pd->write_speed) {
pd->read_speed = MAX_SPEED;
@@ -765,7 +769,7 @@ static void pkt_gather_data(struct pktcdvd_device *pd, struct packet_data *pkt)
atomic_inc(&pkt->io_wait);
bio->bi_rw = READ;
- pkt_queue_bio(pd, bio, 0);
+ pkt_queue_bio(pd, bio);
frames_read++;
}
@@ -914,8 +918,10 @@ static int pkt_handle_queue(struct pktcdvd_device *pd)
bio = node->bio;
zone = ZONE(bio->bi_sector, pd);
list_for_each_entry(p, &pd->cdrw.pkt_active_list, list) {
- if (p->sector == zone)
+ if (p->sector == zone) {
+ bio = NULL;
goto try_next_bio;
+ }
}
break;
try_next_bio:
@@ -1060,7 +1066,7 @@ static void pkt_start_write(struct pktcdvd_device *pd, struct packet_data *pkt)
atomic_set(&pkt->io_wait, 1);
pkt->w_bio->bi_rw = WRITE;
- pkt_queue_bio(pd, pkt->w_bio, 0);
+ pkt_queue_bio(pd, pkt->w_bio);
}
static void pkt_finish_packet(struct packet_data *pkt, int uptodate)
@@ -1245,8 +1251,7 @@ static int kcdrwd(void *foobar)
VPRINTK("kcdrwd: wake up\n");
/* make swsusp happy with our thread */
- if (current->flags & PF_FREEZE)
- refrigerator(PF_FREEZE);
+ try_to_freeze();
list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
if (!pkt->sleep_time)
@@ -2019,7 +2024,13 @@ static int pkt_open(struct inode *inode, struct file *file)
BUG_ON(pd->refcnt < 0);
pd->refcnt++;
- if (pd->refcnt == 1) {
+ if (pd->refcnt > 1) {
+ if ((file->f_mode & FMODE_WRITE) &&
+ !test_bit(PACKET_WRITABLE, &pd->flags)) {
+ ret = -EBUSY;
+ goto out_dec;
+ }
+ } else {
if (pkt_open_dev(pd, file->f_mode & FMODE_WRITE)) {
ret = -EIO;
goto out_dec;
@@ -2112,7 +2123,7 @@ static int pkt_make_request(request_queue_t *q, struct bio *bio)
cloned_bio->bi_private = psd;
cloned_bio->bi_end_io = pkt_end_io_read_cloned;
pd->stats.secs_r += bio->bi_size >> 9;
- pkt_queue_bio(pd, cloned_bio, 1);
+ pkt_queue_bio(pd, cloned_bio);
return 0;
}
@@ -2406,7 +2417,7 @@ static int pkt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, u
case CDROM_LAST_WRITTEN:
case CDROM_SEND_PACKET:
case SCSI_IOCTL_SEND_COMMAND:
- return ioctl_by_bdev(pd->bdev, cmd, arg);
+ return blkdev_ioctl(pd->bdev->bd_inode, file, cmd, arg);
case CDROMEJECT:
/*
@@ -2414,7 +2425,7 @@ static int pkt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, u
* have to unlock it or else the eject command fails.
*/
pkt_lock_door(pd, 0);
- return ioctl_by_bdev(pd->bdev, cmd, arg);
+ return blkdev_ioctl(pd->bdev->bd_inode, file, cmd, arg);
default:
printk("pktcdvd: Unknown ioctl for %s (%x)\n", pd->name, cmd);
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-01-05 12:31:05 +0000