[PATCH 1/5] pktcdvd: Fix overflow for discs with large packets

[PATCH 1/5] pktcdvd: Fix overflow for discs with large packets

[Peter Osterlund]

From: Phillip Susi <psusi@cfl.rr.com>

The pktcdvd driver was using an 8 bit field to store the packet length
obtained from the disc track info.  This causes it to overflow packet
length values of 128KB or more.  I changed the field to 32 bits to fix
this.

The pktcdvd driver defaulted to its maximum allowed packet length
when it detected a 0 in the track info field.  I changed this to fail
the operation and refuse to access the media.  This seems more sane
than attempting to access it with a value that almost certainly will
not work.

Signed-off-by: Peter Osterlund <petero2@telia.com>
---

 drivers/block/pktcdvd.c |    2 +-
 include/linux/pktcdvd.h |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index 81ad466..f0a0ad4 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -1640,7 +1640,7 @@ static int pkt_probe_settings(struct pkt
 	pd->settings.size = be32_to_cpu(ti.fixed_packet_size) << 2;
 	if (pd->settings.size == 0) {
 		printk("pktcdvd: detected zero packet size!\n");
-		pd->settings.size = 128;
+		return -ENXIO;
 	}
 	if (pd->settings.size > PACKET_MAX_SECTORS) {
 		printk("pktcdvd: packet size is too big\n");
diff --git a/include/linux/pktcdvd.h b/include/linux/pktcdvd.h
index 2c177e4..d1c9c4a 100644
--- a/include/linux/pktcdvd.h
+++ b/include/linux/pktcdvd.h
@@ -114,7 +114,7 @@ struct pkt_ctrl_command {
 
 struct packet_settings
 {
-	__u8			size;		/* packet size in (512 byte) sectors */
+	__u32			size;		/* packet size in (512 byte) sectors */
 	__u8			fp;		/* fixed packets */
 	__u8			link_loss;	/* the rest is specified
 						 * as per Mt Fuji */
-- 
Peter Osterlund - petero2@telia.com
http://web.telia.com/~u89404340

[PATCH 2/5] pktcdvd: Remove version string

[Peter Osterlund]

The version information is not useful for a driver that is maintained
in Linus' kernel tree.

Signed-off-by: Peter Osterlund <petero2@telia.com>
---

 drivers/block/pktcdvd.c |    3 ---
 1 files changed, 0 insertions(+), 3 deletions(-)

diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index f0a0ad4..01f070a 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -43,8 +43,6 @@
  *
  *************************************************************************/
 
-#define VERSION_CODE	"v0.2.0a 2004-07-14 Jens Axboe (axboe@suse.de) and petero2@telia.com"
-
 #include <linux/pktcdvd.h>
 #include <linux/config.h>
 #include <linux/module.h>
@@ -2679,7 +2677,6 @@ static int __init pkt_init(void)
 
 	pkt_proc = proc_mkdir("pktcdvd", proc_root_driver);
 
-	DPRINTK("pktcdvd: %s\n", VERSION_CODE);
 	return 0;
 
 out:

-- 
Peter Osterlund - petero2@telia.com
http://web.telia.com/~u89404340

[PATCH 3/5] Let CDROM_PKTCDVD_WCACHE depend on EXPERIMENTAL

[Peter Osterlund]

From: Adrian Bunk <bunk@stusta.de>

Unless the help text is outdated, this seems to be logical.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Peter Osterlund <petero2@telia.com>
---

 drivers/block/Kconfig |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
index 139cbba..db6818f 100644
--- a/drivers/block/Kconfig
+++ b/drivers/block/Kconfig
@@ -437,8 +437,8 @@ config CDROM_PKTCDVD_BUFFERS
 	  pktsetup time.
 
 config CDROM_PKTCDVD_WCACHE
-	bool "Enable write caching"
-	depends on CDROM_PKTCDVD
+	bool "Enable write caching (EXPERIMENTAL)"
+	depends on CDROM_PKTCDVD && EXPERIMENTAL
 	help
 	  If enabled, write caching will be set for the CD-R/W device. For now
 	  this option is dangerous unless the CD-RW media is known good, as we

-- 
Peter Osterlund - petero2@telia.com
http://web.telia.com/~u89404340

[PATCH 4/5] pktcdvd: Don't waste kernel memory

[Peter Osterlund]

Allocate memory for read-gathering at open time, when it is known just
how much memory is needed.  This avoids wasting kernel memory when the
real packet size is smaller than the maximum packet size supported by
the driver.  This is always the case when using DVD discs.

Signed-off-by: Peter Osterlund <petero2@telia.com>
---

 drivers/block/Kconfig   |    4 ++--
 drivers/block/pktcdvd.c |   53 +++++++++++++++++++++++++----------------------
 include/linux/pktcdvd.h |    4 ++--
 3 files changed, 32 insertions(+), 29 deletions(-)

diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
index db6818f..8b13316 100644
--- a/drivers/block/Kconfig
+++ b/drivers/block/Kconfig
@@ -433,8 +433,8 @@ config CDROM_PKTCDVD_BUFFERS
 	  This controls the maximum number of active concurrent packets. More
 	  concurrent packets can increase write performance, but also require
 	  more memory. Each concurrent packet will require approximately 64Kb
-	  of non-swappable kernel memory, memory which will be allocated at
-	  pktsetup time.
+	  of non-swappable kernel memory, memory which will be allocated when
+	  a disc is opened for writing.
 
 config CDROM_PKTCDVD_WCACHE
 	bool "Enable write caching (EXPERIMENTAL)"
diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index 01f070a..18d5979 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -130,7 +130,7 @@ static struct bio *pkt_bio_alloc(int nr_
 /*
  * Allocate a packet_data struct
  */
-static struct packet_data *pkt_alloc_packet_data(void)
+static struct packet_data *pkt_alloc_packet_data(int frames)
 {
 	int i;
 	struct packet_data *pkt;
@@ -139,11 +139,12 @@ static struct packet_data *pkt_alloc_pac
 	if (!pkt)
 		goto no_pkt;
 
-	pkt->w_bio = pkt_bio_alloc(PACKET_MAX_SIZE);
+	pkt->frames = frames;
+	pkt->w_bio = pkt_bio_alloc(frames);
 	if (!pkt->w_bio)
 		goto no_bio;
 
-	for (i = 0; i < PAGES_PER_PACKET; i++) {
+	for (i = 0; i < frames / FRAMES_PER_PAGE; i++) {
 		pkt->pages[i] = alloc_page(GFP_KERNEL|__GFP_ZERO);
 		if (!pkt->pages[i])
 			goto no_page;
@@ -151,7 +152,7 @@ static struct packet_data *pkt_alloc_pac
 
 	spin_lock_init(&pkt->lock);
 
-	for (i = 0; i < PACKET_MAX_SIZE; i++) {
+	for (i = 0; i < frames; i++) {
 		struct bio *bio = pkt_bio_alloc(1);
 		if (!bio)
 			goto no_rd_bio;
@@ -161,14 +162,14 @@ static struct packet_data *pkt_alloc_pac
 	return pkt;
 
 no_rd_bio:
-	for (i = 0; i < PACKET_MAX_SIZE; i++) {
+	for (i = 0; i < frames; i++) {
 		struct bio *bio = pkt->r_bios[i];
 		if (bio)
 			bio_put(bio);
 	}
 
 no_page:
-	for (i = 0; i < PAGES_PER_PACKET; i++)
+	for (i = 0; i < frames / FRAMES_PER_PAGE; i++)
 		if (pkt->pages[i])
 			__free_page(pkt->pages[i]);
 	bio_put(pkt->w_bio);
@@ -185,12 +186,12 @@ static void pkt_free_packet_data(struct 
 {
 	int i;
 
-	for (i = 0; i < PACKET_MAX_SIZE; i++) {
+	for (i = 0; i < pkt->frames; i++) {
 		struct bio *bio = pkt->r_bios[i];
 		if (bio)
 			bio_put(bio);
 	}
-	for (i = 0; i < PAGES_PER_PACKET; i++)
+	for (i = 0; i < pkt->frames / FRAMES_PER_PAGE; i++)
 		__free_page(pkt->pages[i]);
 	bio_put(pkt->w_bio);
 	kfree(pkt);
@@ -205,17 +206,17 @@ static void pkt_shrink_pktlist(struct pk
 	list_for_each_entry_safe(pkt, next, &pd->cdrw.pkt_free_list, list) {
 		pkt_free_packet_data(pkt);
 	}
+	INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
 }
 
 static int pkt_grow_pktlist(struct pktcdvd_device *pd, int nr_packets)
 {
 	struct packet_data *pkt;
 
-	INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
-	INIT_LIST_HEAD(&pd->cdrw.pkt_active_list);
-	spin_lock_init(&pd->cdrw.active_list_lock);
+	BUG_ON(!list_empty(&pd->cdrw.pkt_free_list));
+
 	while (nr_packets > 0) {
-		pkt = pkt_alloc_packet_data();
+		pkt = pkt_alloc_packet_data(pd->settings.size >> 2);
 		if (!pkt) {
 			pkt_shrink_pktlist(pd);
 			return 0;
@@ -950,7 +951,7 @@ try_next_bio:
 
 	pd->current_sector = zone + pd->settings.size;
 	pkt->sector = zone;
-	pkt->frames = pd->settings.size >> 2;
+	BUG_ON(pkt->frames != pd->settings.size >> 2);
 	pkt->write_size = 0;
 
 	/*
@@ -1986,8 +1987,14 @@ static int pkt_open_dev(struct pktcdvd_d
 	if ((ret = pkt_set_segment_merging(pd, q)))
 		goto out_unclaim;
 
-	if (write)
+	if (write) {
+		if (!pkt_grow_pktlist(pd, CONFIG_CDROM_PKTCDVD_BUFFERS)) {
+			printk("pktcdvd: not enough memory for buffers\n");
+			ret = -ENOMEM;
+			goto out_unclaim;
+		}
 		printk("pktcdvd: %lukB available on disc\n", lba << 1);
+	}
 
 	return 0;
 
@@ -2013,6 +2020,8 @@ static void pkt_release_dev(struct pktcd
 	pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
 	bd_release(pd->bdev);
 	blkdev_put(pd->bdev);
+
+	pkt_shrink_pktlist(pd);
 }
 
 static struct pktcdvd_device *pkt_find_dev_from_minor(int dev_minor)
@@ -2378,12 +2387,6 @@ static int pkt_new_dev(struct pktcdvd_de
 	/* This is safe, since we have a reference from open(). */
 	__module_get(THIS_MODULE);
 
-	if (!pkt_grow_pktlist(pd, CONFIG_CDROM_PKTCDVD_BUFFERS)) {
-		printk("pktcdvd: not enough memory for buffers\n");
-		ret = -ENOMEM;
-		goto out_mem;
-	}
-
 	pd->bdev = bdev;
 	set_blocksize(bdev, CD_FRAMESIZE);
 
@@ -2394,7 +2397,7 @@ static int pkt_new_dev(struct pktcdvd_de
 	if (IS_ERR(pd->cdrw.thread)) {
 		printk("pktcdvd: can't start kernel thread\n");
 		ret = -ENOMEM;
-		goto out_thread;
+		goto out_mem;
 	}
 
 	proc = create_proc_entry(pd->name, 0, pkt_proc);
@@ -2405,8 +2408,6 @@ static int pkt_new_dev(struct pktcdvd_de
 	DPRINTK("pktcdvd: writer %s mapped to %s\n", pd->name, bdevname(bdev, b));
 	return 0;
 
-out_thread:
-	pkt_shrink_pktlist(pd);
 out_mem:
 	blkdev_put(bdev);
 	/* This is safe: open() is still holding a reference. */
@@ -2502,6 +2503,10 @@ static int pkt_setup_dev(struct pkt_ctrl
 		goto out_mem;
 	pd->disk = disk;
 
+	INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
+	INIT_LIST_HEAD(&pd->cdrw.pkt_active_list);
+	spin_lock_init(&pd->cdrw.active_list_lock);
+
 	spin_lock_init(&pd->lock);
 	spin_lock_init(&pd->iosched.lock);
 	sprintf(pd->name, "pktcdvd%d", idx);
@@ -2566,8 +2571,6 @@ static int pkt_remove_dev(struct pkt_ctr
 
 	blkdev_put(pd->bdev);
 
-	pkt_shrink_pktlist(pd);
-
 	remove_proc_entry(pd->name, pkt_proc);
 	DPRINTK("pktcdvd: writer %s unmapped\n", pd->name);
 
diff --git a/include/linux/pktcdvd.h b/include/linux/pktcdvd.h
index d1c9c4a..1623da8 100644
--- a/include/linux/pktcdvd.h
+++ b/include/linux/pktcdvd.h
@@ -170,7 +170,7 @@ struct packet_iosched
 #error "PAGE_SIZE must be a multiple of CD_FRAMESIZE"
 #endif
 #define PACKET_MAX_SIZE		32
-#define PAGES_PER_PACKET	(PACKET_MAX_SIZE * CD_FRAMESIZE / PAGE_SIZE)
+#define FRAMES_PER_PAGE		(PAGE_SIZE / CD_FRAMESIZE)
 #define PACKET_MAX_SECTORS	(PACKET_MAX_SIZE * CD_FRAMESIZE >> 9)
 
 enum packet_data_state {
@@ -219,7 +219,7 @@ struct packet_data
 	atomic_t		io_errors;	/* Number of read/write errors during IO */
 
 	struct bio		*r_bios[PACKET_MAX_SIZE]; /* bios to use during data gathering */
-	struct page		*pages[PAGES_PER_PACKET];
+	struct page		*pages[PACKET_MAX_SIZE / FRAMES_PER_PAGE];
 
 	int			cache_valid;	/* If non-zero, the data for the zone defined */
 						/* by the sector variable is completely cached */

-- 
Peter Osterlund - petero2@telia.com
http://web.telia.com/~u89404340

[PATCH 5/5] pktcdvd: Allow larger packets

[Peter Osterlund]

From: Phillip Susi <psusi@cfl.rr.com>

The pktcdvd driver uses a compile time macro constant to define the
maximum supported packet length.  I changed this from 32 sectors to
128 sectors because that allows over 100 MB of additional usable space
on a 700 MB cdrw, and increases throughput.

Note that you need a modified cdrwtool program that can format a CDRW
disc with larger packets to benefit from this change.

Signed-off-by: Peter Osterlund <petero2@telia.com>
---

 include/linux/pktcdvd.h |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/include/linux/pktcdvd.h b/include/linux/pktcdvd.h
index 1623da8..8a94c71 100644
--- a/include/linux/pktcdvd.h
+++ b/include/linux/pktcdvd.h
@@ -169,7 +169,7 @@ struct packet_iosched
 #if (PAGE_SIZE % CD_FRAMESIZE) != 0
 #error "PAGE_SIZE must be a multiple of CD_FRAMESIZE"
 #endif
-#define PACKET_MAX_SIZE		32
+#define PACKET_MAX_SIZE		128
 #define FRAMES_PER_PAGE		(PAGE_SIZE / CD_FRAMESIZE)
 #define PACKET_MAX_SECTORS	(PACKET_MAX_SIZE * CD_FRAMESIZE >> 9)
 

-- 
Peter Osterlund - petero2@telia.com
http://web.telia.com/~u89404340

Re: [PATCH 2/5] pktcdvd: Remove version string

[Ismail Donmez]

Cuma 3 Şubat 2006 22:18 tarihinde şunları yazmıştınız:
> The version information is not useful for a driver that is maintained
> in Linus' kernel tree.
>
> Signed-off-by: Peter Osterlund <petero2@telia.com>
> ---
>
>  drivers/block/pktcdvd.c |    3 ---
>  1 files changed, 0 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
> index f0a0ad4..01f070a 100644
> --- a/drivers/block/pktcdvd.c
> +++ b/drivers/block/pktcdvd.c
> @@ -43,8 +43,6 @@
>   *
>  
> *************************************************************************/
>
> -#define VERSION_CODE	"v0.2.0a 2004-07-14 Jens Axboe (axboe@suse.de) and
> petero2@telia.com" -
>  #include <linux/pktcdvd.h>
>  #include <linux/config.h>
>  #include <linux/module.h>
> @@ -2679,7 +2677,6 @@ static int __init pkt_init(void)
>
>  	pkt_proc = proc_mkdir("pktcdvd", proc_root_driver);
>
> -	DPRINTK("pktcdvd: %s\n", VERSION_CODE);
>  	return 0;
>
>  out:

Hmm this is useful to do dmesg|grep pktcdvd though when you compile it in the 
kernel. So I would like to keep it in.

Just my 2 cents.

Regards,
ismail

Re: [PATCH 2/5] pktcdvd: Remove version string

[Peter Osterlund]

Ismail Donmez <ismail@uludag.org.tr> writes:

> Cuma 3 Şubat 2006 22:18 tarihinde şunları yazmıştınız:
> > The version information is not useful for a driver that is maintained
> > in Linus' kernel tree.
> >
> > Signed-off-by: Peter Osterlund <petero2@telia.com>
...
> Hmm this is useful to do dmesg|grep pktcdvd though when you compile it in the 
> kernel. So I would like to keep it in.

Why is it useful? The actual version number can't be that useful since
it hasn't been updated since 2004. If you just want to know if the
driver is currently in the kernel, you can do:

        cat /proc/misc | grep pktcdvd

-- 
Peter Osterlund - petero2@telia.com
http://web.telia.com/~u89404340