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linux/drivers/block/pktcdvd.c
Peter Osterlund 05680d86d2 pktcdvd: reduce stack consumption 
On my system, pkt_open() consumes 584 bytes because the compiler decides to
inline lots of functions that would not normally be part of long call chains.
The following patch fixes that problem on my system.

Signed-off-by: Peter Osterlund <petero2@telia.com>
Cc: Nix <nix@esperi.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-03-04 16:35:12 -08:00

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/*
* Copyright (C) 2000 Jens Axboe <axboe@suse.de>
* Copyright (C) 2001-2004 Peter Osterlund <petero2@telia.com>
* Copyright (C) 2006 Thomas Maier <balagi@justmail.de>
*
* May be copied or modified under the terms of the GNU General Public
* License. See linux/COPYING for more information.
*
* Packet writing layer for ATAPI and SCSI CD-RW, DVD+RW, DVD-RW and
* DVD-RAM devices.
*
* Theory of operation:
*
* At the lowest level, there is the standard driver for the CD/DVD device,
* typically ide-cd.c or sr.c. This driver can handle read and write requests,
* but it doesn't know anything about the special restrictions that apply to
* packet writing. One restriction is that write requests must be aligned to
* packet boundaries on the physical media, and the size of a write request
* must be equal to the packet size. Another restriction is that a
* GPCMD_FLUSH_CACHE command has to be issued to the drive before a read
* command, if the previous command was a write.
*
* The purpose of the packet writing driver is to hide these restrictions from
* higher layers, such as file systems, and present a block device that can be
* randomly read and written using 2kB-sized blocks.
*
* The lowest layer in the packet writing driver is the packet I/O scheduler.
* Its data is defined by the struct packet_iosched and includes two bio
* queues with pending read and write requests. These queues are processed
* by the pkt_iosched_process_queue() function. The write requests in this
* queue are already properly aligned and sized. This layer is responsible for
* issuing the flush cache commands and scheduling the I/O in a good order.
*
* The next layer transforms unaligned write requests to aligned writes. This
* transformation requires reading missing pieces of data from the underlying
* block device, assembling the pieces to full packets and queuing them to the
* packet I/O scheduler.
*
* At the top layer there is a custom make_request_fn function that forwards
* read requests directly to the iosched queue and puts write requests in the
* unaligned write queue. A kernel thread performs the necessary read
* gathering to convert the unaligned writes to aligned writes and then feeds
* them to the packet I/O scheduler.
*
*************************************************************************/
#include <linux/pktcdvd.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/kthread.h>
#include <linux/errno.h>
#include <linux/spinlock.h>
#include <linux/file.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/miscdevice.h>
#include <linux/freezer.h>
#include <linux/mutex.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_ioctl.h>
#include <scsi/scsi.h>
#include <linux/debugfs.h>
#include <linux/device.h>
#include <asm/uaccess.h>
#define DRIVER_NAME "pktcdvd"
#if PACKET_DEBUG
#define DPRINTK(fmt, args...) printk(KERN_NOTICE fmt, ##args)
#else
#define DPRINTK(fmt, args...)
#endif
#if PACKET_DEBUG > 1
#define VPRINTK(fmt, args...) printk(KERN_NOTICE fmt, ##args)
#else
#define VPRINTK(fmt, args...)
#endif
#define MAX_SPEED 0xffff
#define ZONE(sector, pd) (((sector) + (pd)->offset) & ~((pd)->settings.size - 1))
static struct pktcdvd_device *pkt_devs[MAX_WRITERS];
static struct proc_dir_entry *pkt_proc;
static int pktdev_major;
static int write_congestion_on = PKT_WRITE_CONGESTION_ON;
static int write_congestion_off = PKT_WRITE_CONGESTION_OFF;
static struct mutex ctl_mutex; /* Serialize open/close/setup/teardown */
static mempool_t *psd_pool;
static struct class *class_pktcdvd = NULL; /* /sys/class/pktcdvd */
static struct dentry *pkt_debugfs_root = NULL; /* /debug/pktcdvd */
/* forward declaration */
static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev);
static int pkt_remove_dev(dev_t pkt_dev);
static int pkt_seq_show(struct seq_file *m, void *p);
/*
* create and register a pktcdvd kernel object.
*/
static struct pktcdvd_kobj* pkt_kobj_create(struct pktcdvd_device *pd,
const char* name,
struct kobject* parent,
struct kobj_type* ktype)
{
struct pktcdvd_kobj *p;
int error;
p = kzalloc(sizeof(*p), GFP_KERNEL);
if (!p)
return NULL;
p->pd = pd;
error = kobject_init_and_add(&p->kobj, ktype, parent, "%s", name);
if (error) {
kobject_put(&p->kobj);
return NULL;
}
kobject_uevent(&p->kobj, KOBJ_ADD);
return p;
}
/*
* remove a pktcdvd kernel object.
*/
static void pkt_kobj_remove(struct pktcdvd_kobj *p)
{
if (p)
kobject_put(&p->kobj);
}
/*
* default release function for pktcdvd kernel objects.
*/
static void pkt_kobj_release(struct kobject *kobj)
{
kfree(to_pktcdvdkobj(kobj));
}
/**********************************************************
*
* sysfs interface for pktcdvd
* by (C) 2006 Thomas Maier <balagi@justmail.de>
*
**********************************************************/
#define DEF_ATTR(_obj,_name,_mode) \
static struct attribute _obj = { .name = _name, .mode = _mode }
/**********************************************************
/sys/class/pktcdvd/pktcdvd[0-7]/
stat/reset
stat/packets_started
stat/packets_finished
stat/kb_written
stat/kb_read
stat/kb_read_gather
write_queue/size
write_queue/congestion_off
write_queue/congestion_on
**********************************************************/
DEF_ATTR(kobj_pkt_attr_st1, "reset", 0200);
DEF_ATTR(kobj_pkt_attr_st2, "packets_started", 0444);
DEF_ATTR(kobj_pkt_attr_st3, "packets_finished", 0444);
DEF_ATTR(kobj_pkt_attr_st4, "kb_written", 0444);
DEF_ATTR(kobj_pkt_attr_st5, "kb_read", 0444);
DEF_ATTR(kobj_pkt_attr_st6, "kb_read_gather", 0444);
static struct attribute *kobj_pkt_attrs_stat[] = {
&kobj_pkt_attr_st1,
&kobj_pkt_attr_st2,
&kobj_pkt_attr_st3,
&kobj_pkt_attr_st4,
&kobj_pkt_attr_st5,
&kobj_pkt_attr_st6,
NULL
};
DEF_ATTR(kobj_pkt_attr_wq1, "size", 0444);
DEF_ATTR(kobj_pkt_attr_wq2, "congestion_off", 0644);
DEF_ATTR(kobj_pkt_attr_wq3, "congestion_on", 0644);
static struct attribute *kobj_pkt_attrs_wqueue[] = {
&kobj_pkt_attr_wq1,
&kobj_pkt_attr_wq2,
&kobj_pkt_attr_wq3,
NULL
};
static ssize_t kobj_pkt_show(struct kobject *kobj,
struct attribute *attr, char *data)
{
struct pktcdvd_device *pd = to_pktcdvdkobj(kobj)->pd;
int n = 0;
int v;
if (strcmp(attr->name, "packets_started") == 0) {
n = sprintf(data, "%lu\n", pd->stats.pkt_started);
} else if (strcmp(attr->name, "packets_finished") == 0) {
n = sprintf(data, "%lu\n", pd->stats.pkt_ended);
} else if (strcmp(attr->name, "kb_written") == 0) {
n = sprintf(data, "%lu\n", pd->stats.secs_w >> 1);
} else if (strcmp(attr->name, "kb_read") == 0) {
n = sprintf(data, "%lu\n", pd->stats.secs_r >> 1);
} else if (strcmp(attr->name, "kb_read_gather") == 0) {
n = sprintf(data, "%lu\n", pd->stats.secs_rg >> 1);
} else if (strcmp(attr->name, "size") == 0) {
spin_lock(&pd->lock);
v = pd->bio_queue_size;
spin_unlock(&pd->lock);
n = sprintf(data, "%d\n", v);
} else if (strcmp(attr->name, "congestion_off") == 0) {
spin_lock(&pd->lock);
v = pd->write_congestion_off;
spin_unlock(&pd->lock);
n = sprintf(data, "%d\n", v);
} else if (strcmp(attr->name, "congestion_on") == 0) {
spin_lock(&pd->lock);
v = pd->write_congestion_on;
spin_unlock(&pd->lock);
n = sprintf(data, "%d\n", v);
}
return n;
}
static void init_write_congestion_marks(int* lo, int* hi)
{
if (*hi > 0) {
*hi = max(*hi, 500);
*hi = min(*hi, 1000000);
if (*lo <= 0)
*lo = *hi - 100;
else {
*lo = min(*lo, *hi - 100);
*lo = max(*lo, 100);
}
} else {
*hi = -1;
*lo = -1;
}
}
static ssize_t kobj_pkt_store(struct kobject *kobj,
struct attribute *attr,
const char *data, size_t len)
{
struct pktcdvd_device *pd = to_pktcdvdkobj(kobj)->pd;
int val;
if (strcmp(attr->name, "reset") == 0 && len > 0) {
pd->stats.pkt_started = 0;
pd->stats.pkt_ended = 0;
pd->stats.secs_w = 0;
pd->stats.secs_rg = 0;
pd->stats.secs_r = 0;
} else if (strcmp(attr->name, "congestion_off") == 0
&& sscanf(data, "%d", &val) == 1) {
spin_lock(&pd->lock);
pd->write_congestion_off = val;
init_write_congestion_marks(&pd->write_congestion_off,
&pd->write_congestion_on);
spin_unlock(&pd->lock);
} else if (strcmp(attr->name, "congestion_on") == 0
&& sscanf(data, "%d", &val) == 1) {
spin_lock(&pd->lock);
pd->write_congestion_on = val;
init_write_congestion_marks(&pd->write_congestion_off,
&pd->write_congestion_on);
spin_unlock(&pd->lock);
}
return len;
}
static struct sysfs_ops kobj_pkt_ops = {
.show = kobj_pkt_show,
.store = kobj_pkt_store
};
static struct kobj_type kobj_pkt_type_stat = {
.release = pkt_kobj_release,
.sysfs_ops = &kobj_pkt_ops,
.default_attrs = kobj_pkt_attrs_stat
};
static struct kobj_type kobj_pkt_type_wqueue = {
.release = pkt_kobj_release,
.sysfs_ops = &kobj_pkt_ops,
.default_attrs = kobj_pkt_attrs_wqueue
};
static void pkt_sysfs_dev_new(struct pktcdvd_device *pd)
{
if (class_pktcdvd) {
pd->dev = device_create(class_pktcdvd, NULL, pd->pkt_dev, "%s", pd->name);
if (IS_ERR(pd->dev))
pd->dev = NULL;
}
if (pd->dev) {
pd->kobj_stat = pkt_kobj_create(pd, "stat",
&pd->dev->kobj,
&kobj_pkt_type_stat);
pd->kobj_wqueue = pkt_kobj_create(pd, "write_queue",
&pd->dev->kobj,
&kobj_pkt_type_wqueue);
}
}
static void pkt_sysfs_dev_remove(struct pktcdvd_device *pd)
{
pkt_kobj_remove(pd->kobj_stat);
pkt_kobj_remove(pd->kobj_wqueue);
if (class_pktcdvd)
device_destroy(class_pktcdvd, pd->pkt_dev);
}
/********************************************************************
/sys/class/pktcdvd/
add map block device
remove unmap packet dev
device_map show mappings
*******************************************************************/
static void class_pktcdvd_release(struct class *cls)
{
kfree(cls);
}
static ssize_t class_pktcdvd_show_map(struct class *c, char *data)
{
int n = 0;
int idx;
mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
for (idx = 0; idx < MAX_WRITERS; idx++) {
struct pktcdvd_device *pd = pkt_devs[idx];
if (!pd)
continue;
n += sprintf(data+n, "%s %u:%u %u:%u\n",
pd->name,
MAJOR(pd->pkt_dev), MINOR(pd->pkt_dev),
MAJOR(pd->bdev->bd_dev),
MINOR(pd->bdev->bd_dev));
}
mutex_unlock(&ctl_mutex);
return n;
}
static ssize_t class_pktcdvd_store_add(struct class *c, const char *buf,
size_t count)
{
unsigned int major, minor;
if (sscanf(buf, "%u:%u", &major, &minor) == 2) {
/* pkt_setup_dev() expects caller to hold reference to self */
if (!try_module_get(THIS_MODULE))
return -ENODEV;
pkt_setup_dev(MKDEV(major, minor), NULL);
module_put(THIS_MODULE);
return count;
}
return -EINVAL;
}
static ssize_t class_pktcdvd_store_remove(struct class *c, const char *buf,
size_t count)
{
unsigned int major, minor;
if (sscanf(buf, "%u:%u", &major, &minor) == 2) {
pkt_remove_dev(MKDEV(major, minor));
return count;
}
return -EINVAL;
}
static struct class_attribute class_pktcdvd_attrs[] = {
__ATTR(add, 0200, NULL, class_pktcdvd_store_add),
__ATTR(remove, 0200, NULL, class_pktcdvd_store_remove),
__ATTR(device_map, 0444, class_pktcdvd_show_map, NULL),
__ATTR_NULL
};
static int pkt_sysfs_init(void)
{
int ret = 0;
/*
* create control files in sysfs
* /sys/class/pktcdvd/...
*/
class_pktcdvd = kzalloc(sizeof(*class_pktcdvd), GFP_KERNEL);
if (!class_pktcdvd)
return -ENOMEM;
class_pktcdvd->name = DRIVER_NAME;
class_pktcdvd->owner = THIS_MODULE;
class_pktcdvd->class_release = class_pktcdvd_release;
class_pktcdvd->class_attrs = class_pktcdvd_attrs;
ret = class_register(class_pktcdvd);
if (ret) {
kfree(class_pktcdvd);
class_pktcdvd = NULL;
printk(DRIVER_NAME": failed to create class pktcdvd\n");
return ret;
}
return 0;
}
static void pkt_sysfs_cleanup(void)
{
if (class_pktcdvd)
class_destroy(class_pktcdvd);
class_pktcdvd = NULL;
}
/********************************************************************
entries in debugfs
/debugfs/pktcdvd[0-7]/
info
*******************************************************************/
static int pkt_debugfs_seq_show(struct seq_file *m, void *p)
{
return pkt_seq_show(m, p);
}
static int pkt_debugfs_fops_open(struct inode *inode, struct file *file)
{
return single_open(file, pkt_debugfs_seq_show, inode->i_private);
}
static const struct file_operations debug_fops = {
.open = pkt_debugfs_fops_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
.owner = THIS_MODULE,
};
static void pkt_debugfs_dev_new(struct pktcdvd_device *pd)
{
if (!pkt_debugfs_root)
return;
pd->dfs_f_info = NULL;
pd->dfs_d_root = debugfs_create_dir(pd->name, pkt_debugfs_root);
if (IS_ERR(pd->dfs_d_root)) {
pd->dfs_d_root = NULL;
return;
}
pd->dfs_f_info = debugfs_create_file("info", S_IRUGO,
pd->dfs_d_root, pd, &debug_fops);
if (IS_ERR(pd->dfs_f_info)) {
pd->dfs_f_info = NULL;
return;
}
}
static void pkt_debugfs_dev_remove(struct pktcdvd_device *pd)
{
if (!pkt_debugfs_root)
return;
if (pd->dfs_f_info)
debugfs_remove(pd->dfs_f_info);
pd->dfs_f_info = NULL;
if (pd->dfs_d_root)
debugfs_remove(pd->dfs_d_root);
pd->dfs_d_root = NULL;
}
static void pkt_debugfs_init(void)
{
pkt_debugfs_root = debugfs_create_dir(DRIVER_NAME, NULL);
if (IS_ERR(pkt_debugfs_root)) {
pkt_debugfs_root = NULL;
return;
}
}
static void pkt_debugfs_cleanup(void)
{
if (!pkt_debugfs_root)
return;
debugfs_remove(pkt_debugfs_root);
pkt_debugfs_root = NULL;
}
/* ----------------------------------------------------------*/
static void pkt_bio_finished(struct pktcdvd_device *pd)
{
BUG_ON(atomic_read(&pd->cdrw.pending_bios) <= 0);
if (atomic_dec_and_test(&pd->cdrw.pending_bios)) {
VPRINTK(DRIVER_NAME": queue empty\n");
atomic_set(&pd->iosched.attention, 1);
wake_up(&pd->wqueue);
}
}
static void pkt_bio_destructor(struct bio *bio)
{
kfree(bio->bi_io_vec);
kfree(bio);
}
static struct bio *pkt_bio_alloc(int nr_iovecs)
{
struct bio_vec *bvl = NULL;
struct bio *bio;
bio = kmalloc(sizeof(struct bio), GFP_KERNEL);
if (!bio)
goto no_bio;
bio_init(bio);
bvl = kcalloc(nr_iovecs, sizeof(struct bio_vec), GFP_KERNEL);
if (!bvl)
goto no_bvl;
bio->bi_max_vecs = nr_iovecs;
bio->bi_io_vec = bvl;
bio->bi_destructor = pkt_bio_destructor;
return bio;
no_bvl:
kfree(bio);
no_bio:
return NULL;
}
/*
* Allocate a packet_data struct
*/
static struct packet_data *pkt_alloc_packet_data(int frames)
{
int i;
struct packet_data *pkt;
pkt = kzalloc(sizeof(struct packet_data), GFP_KERNEL);
if (!pkt)
goto no_pkt;
pkt->frames = frames;
pkt->w_bio = pkt_bio_alloc(frames);
if (!pkt->w_bio)
goto no_bio;
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;
}
spin_lock_init(&pkt->lock);
for (i = 0; i < frames; i++) {
struct bio *bio = pkt_bio_alloc(1);
if (!bio)
goto no_rd_bio;
pkt->r_bios[i] = bio;
}
return pkt;
no_rd_bio:
for (i = 0; i < frames; i++) {
struct bio *bio = pkt->r_bios[i];
if (bio)
bio_put(bio);
}
no_page:
for (i = 0; i < frames / FRAMES_PER_PAGE; i++)
if (pkt->pages[i])
__free_page(pkt->pages[i]);
bio_put(pkt->w_bio);
no_bio:
kfree(pkt);
no_pkt:
return NULL;
}
/*
* Free a packet_data struct
*/
static void pkt_free_packet_data(struct packet_data *pkt)
{
int i;
for (i = 0; i < pkt->frames; i++) {
struct bio *bio = pkt->r_bios[i];
if (bio)
bio_put(bio);
}
for (i = 0; i < pkt->frames / FRAMES_PER_PAGE; i++)
__free_page(pkt->pages[i]);
bio_put(pkt->w_bio);
kfree(pkt);
}
static void pkt_shrink_pktlist(struct pktcdvd_device *pd)
{
struct packet_data *pkt, *next;
BUG_ON(!list_empty(&pd->cdrw.pkt_active_list));
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;
BUG_ON(!list_empty(&pd->cdrw.pkt_free_list));
while (nr_packets > 0) {
pkt = pkt_alloc_packet_data(pd->settings.size >> 2);
if (!pkt) {
pkt_shrink_pktlist(pd);
return 0;
}
pkt->id = nr_packets;
pkt->pd = pd;
list_add(&pkt->list, &pd->cdrw.pkt_free_list);
nr_packets--;
}
return 1;
}
static inline struct pkt_rb_node *pkt_rbtree_next(struct pkt_rb_node *node)
{
struct rb_node *n = rb_next(&node->rb_node);
if (!n)
return NULL;
return rb_entry(n, struct pkt_rb_node, rb_node);
}
static void pkt_rbtree_erase(struct pktcdvd_device *pd, struct pkt_rb_node *node)
{
rb_erase(&node->rb_node, &pd->bio_queue);
mempool_free(node, pd->rb_pool);
pd->bio_queue_size--;
BUG_ON(pd->bio_queue_size < 0);
}
/*
* Find the first node in the pd->bio_queue rb tree with a starting sector >= s.
*/
static struct pkt_rb_node *pkt_rbtree_find(struct pktcdvd_device *pd, sector_t s)
{
struct rb_node *n = pd->bio_queue.rb_node;
struct rb_node *next;
struct pkt_rb_node *tmp;
if (!n) {
BUG_ON(pd->bio_queue_size > 0);
return NULL;
}
for (;;) {
tmp = rb_entry(n, struct pkt_rb_node, rb_node);
if (s <= tmp->bio->bi_sector)
next = n->rb_left;
else
next = n->rb_right;
if (!next)
break;
n = next;
}
if (s > tmp->bio->bi_sector) {
tmp = pkt_rbtree_next(tmp);
if (!tmp)
return NULL;
}
BUG_ON(s > tmp->bio->bi_sector);
return tmp;
}
/*
* Insert a node into the pd->bio_queue rb tree.
*/
static void pkt_rbtree_insert(struct pktcdvd_device *pd, struct pkt_rb_node *node)
{
struct rb_node **p = &pd->bio_queue.rb_node;
struct rb_node *parent = NULL;
sector_t s = node->bio->bi_sector;
struct pkt_rb_node *tmp;
while (*p) {
parent = *p;
tmp = rb_entry(parent, struct pkt_rb_node, rb_node);
if (s < tmp->bio->bi_sector)
p = &(*p)->rb_left;
else
p = &(*p)->rb_right;
}
rb_link_node(&node->rb_node, parent, p);
rb_insert_color(&node->rb_node, &pd->bio_queue);
pd->bio_queue_size++;
}
/*
* 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.
*/
static int pkt_generic_packet(struct pktcdvd_device *pd, struct packet_command *cgc)
{
struct request_queue *q = bdev_get_queue(pd->bdev);
struct request *rq;
int ret = 0;
rq = blk_get_request(q, (cgc->data_direction == CGC_DATA_WRITE) ?
WRITE : READ, __GFP_WAIT);
if (cgc->buflen) {
if (blk_rq_map_kern(q, rq, cgc->buffer, cgc->buflen, __GFP_WAIT))
goto out;
}
rq->cmd_len = COMMAND_SIZE(cgc->cmd[0]);
memcpy(rq->cmd, cgc->cmd, CDROM_PACKET_SIZE);
if (sizeof(rq->cmd) > CDROM_PACKET_SIZE)
memset(rq->cmd + CDROM_PACKET_SIZE, 0, sizeof(rq->cmd) - CDROM_PACKET_SIZE);
rq->timeout = 60*HZ;
rq->cmd_type = REQ_TYPE_BLOCK_PC;
rq->cmd_flags |= REQ_HARDBARRIER;
if (cgc->quiet)
rq->cmd_flags |= REQ_QUIET;
blk_execute_rq(rq->q, pd->bdev->bd_disk, rq, 0);
if (rq->errors)
ret = -EIO;
out:
blk_put_request(rq);
return ret;
}
/*
* A generic sense dump / resolve mechanism should be implemented across
* all ATAPI + SCSI devices.
*/
static void pkt_dump_sense(struct packet_command *cgc)
{
static char *info[9] = { "No sense", "Recovered error", "Not ready",
"Medium error", "Hardware error", "Illegal request",
"Unit attention", "Data protect", "Blank check" };
int i;
struct request_sense *sense = cgc->sense;
printk(DRIVER_NAME":");
for (i = 0; i < CDROM_PACKET_SIZE; i++)
printk(" %02x", cgc->cmd[i]);
printk(" - ");
if (sense == NULL) {
printk("no sense\n");
return;
}
printk("sense %02x.%02x.%02x", sense->sense_key, sense->asc, sense->ascq);
if (sense->sense_key > 8) {
printk(" (INVALID)\n");
return;
}
printk(" (%s)\n", info[sense->sense_key]);
}
/*
* flush the drive cache to media
*/
static int pkt_flush_cache(struct pktcdvd_device *pd)
{
struct packet_command cgc;
init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
cgc.cmd[0] = GPCMD_FLUSH_CACHE;
cgc.quiet = 1;
/*
* the IMMED bit -- we default to not setting it, although that
* would allow a much faster close, this is safer
*/
#if 0
cgc.cmd[1] = 1 << 1;
#endif
return pkt_generic_packet(pd, &cgc);
}
/*
* speed is given as the normal factor, e.g. 4 for 4x
*/
static noinline_for_stack int pkt_set_speed(struct pktcdvd_device *pd,
unsigned write_speed, unsigned read_speed)
{
struct packet_command cgc;
struct request_sense sense;
int ret;
init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
cgc.sense = &sense;
cgc.cmd[0] = GPCMD_SET_SPEED;
cgc.cmd[2] = (read_speed >> 8) & 0xff;
cgc.cmd[3] = read_speed & 0xff;
cgc.cmd[4] = (write_speed >> 8) & 0xff;
cgc.cmd[5] = write_speed & 0xff;
if ((ret = pkt_generic_packet(pd, &cgc)))
pkt_dump_sense(&cgc);
return ret;
}
/*
* 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)
{
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);
}
spin_unlock(&pd->iosched.lock);
atomic_set(&pd->iosched.attention, 1);
wake_up(&pd->wqueue);
}
/*
* Process the queued read/write requests. This function handles special
* 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 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.
*/
static void pkt_iosched_process_queue(struct pktcdvd_device *pd)
{
if (atomic_read(&pd->iosched.attention) == 0)
return;
atomic_set(&pd->iosched.attention, 0);
for (;;) {
struct bio *bio;
int reads_queued, writes_queued;
spin_lock(&pd->iosched.lock);
reads_queued = (pd->iosched.read_queue != NULL);
writes_queued = (pd->iosched.write_queue != NULL);
spin_unlock(&pd->iosched.lock);
if (!reads_queued && !writes_queued)
break;
if (pd->iosched.writing) {
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(DRIVER_NAME": write, waiting\n");
break;
}
pkt_flush_cache(pd);
pd->iosched.writing = 0;
}
} else {
if (!reads_queued && writes_queued) {
if (atomic_read(&pd->cdrw.pending_bios) > 0) {
VPRINTK(DRIVER_NAME": read, waiting\n");
break;
}
pd->iosched.writing = 1;
}
}
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);
}
spin_unlock(&pd->iosched.lock);
if (!bio)
continue;
if (bio_data_dir(bio) == READ)
pd->iosched.successive_reads += bio->bi_size >> 10;
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;
pkt_set_speed(pd, pd->write_speed, pd->read_speed);
}
} else {
if (pd->read_speed != pd->write_speed) {
pd->read_speed = pd->write_speed;
pkt_set_speed(pd, pd->write_speed, pd->read_speed);
}
}
atomic_inc(&pd->cdrw.pending_bios);
generic_make_request(bio);
}
}
/*
* Special care is needed if the underlying block device has a small
* max_phys_segments value.
*/
static int pkt_set_segment_merging(struct pktcdvd_device *pd, struct request_queue *q)
{
if ((pd->settings.size << 9) / CD_FRAMESIZE <= q->max_phys_segments) {
/*
* The cdrom device can handle one segment/frame
*/
clear_bit(PACKET_MERGE_SEGS, &pd->flags);
return 0;
} else if ((pd->settings.size << 9) / PAGE_SIZE <= q->max_phys_segments) {
/*
* We can handle this case at the expense of some extra memory
* copies during write operations
*/
set_bit(PACKET_MERGE_SEGS, &pd->flags);
return 0;
} else {
printk(DRIVER_NAME": cdrom max_phys_segments too small\n");
return -EIO;
}
}
/*
* Copy CD_FRAMESIZE bytes from src_bio into a destination page
*/
static void pkt_copy_bio_data(struct bio *src_bio, int seg, int offs, struct page *dst_page, int dst_offs)
{
unsigned int copy_size = CD_FRAMESIZE;
while (copy_size > 0) {
struct bio_vec *src_bvl = bio_iovec_idx(src_bio, seg);
void *vfrom = kmap_atomic(src_bvl->bv_page, KM_USER0) +
src_bvl->bv_offset + offs;
void *vto = page_address(dst_page) + dst_offs;
int len = min_t(int, copy_size, src_bvl->bv_len - offs);
BUG_ON(len < 0);
memcpy(vto, vfrom, len);
kunmap_atomic(vfrom, KM_USER0);
seg++;
offs = 0;
dst_offs += len;
copy_size -= len;
}
}
/*
* Copy all data for this packet to pkt->pages[], so that
* a) The number of required segments for the write bio is minimized, which
* is necessary for some scsi controllers.
* b) The data can be used as cache to avoid read requests if we receive a
* new write request for the same zone.
*/
static void pkt_make_local_copy(struct packet_data *pkt, struct bio_vec *bvec)
{
int f, p, offs;
/* Copy all data to pkt->pages[] */
p = 0;
offs = 0;
for (f = 0; f < pkt->frames; f++) {
if (bvec[f].bv_page != pkt->pages[p]) {
void *vfrom = kmap_atomic(bvec[f].bv_page, KM_USER0) + bvec[f].bv_offset;
void *vto = page_address(pkt->pages[p]) + offs;
memcpy(vto, vfrom, CD_FRAMESIZE);
kunmap_atomic(vfrom, KM_USER0);
bvec[f].bv_page = pkt->pages[p];
bvec[f].bv_offset = offs;
} else {
BUG_ON(bvec[f].bv_offset != offs);
}
offs += CD_FRAMESIZE;
if (offs >= PAGE_SIZE) {
offs = 0;
p++;
}
}
}
static void pkt_end_io_read(struct bio *bio, int err)
{
struct packet_data *pkt = bio->bi_private;
struct pktcdvd_device *pd = pkt->pd;
BUG_ON(!pd);
VPRINTK("pkt_end_io_read: bio=%p sec0=%llx sec=%llx err=%d\n", bio,
(unsigned long long)pkt->sector, (unsigned long long)bio->bi_sector, err);
if (err)
atomic_inc(&pkt->io_errors);
if (atomic_dec_and_test(&pkt->io_wait)) {
atomic_inc(&pkt->run_sm);
wake_up(&pd->wqueue);
}
pkt_bio_finished(pd);
}
static void pkt_end_io_packet_write(struct bio *bio, int err)
{
struct packet_data *pkt = bio->bi_private;
struct pktcdvd_device *pd = pkt->pd;
BUG_ON(!pd);
VPRINTK("pkt_end_io_packet_write: id=%d, err=%d\n", pkt->id, err);
pd->stats.pkt_ended++;
pkt_bio_finished(pd);
atomic_dec(&pkt->io_wait);
atomic_inc(&pkt->run_sm);
wake_up(&pd->wqueue);
}
/*
* Schedule reads for the holes in a packet
*/
static void pkt_gather_data(struct pktcdvd_device *pd, struct packet_data *pkt)
{
int frames_read = 0;
struct bio *bio;
int f;
char written[PACKET_MAX_SIZE];
BUG_ON(!pkt->orig_bios);
atomic_set(&pkt->io_wait, 0);
atomic_set(&pkt->io_errors, 0);
/*
* Figure out which frames we need to read before we can write.
*/
memset(written, 0, sizeof(written));
spin_lock(&pkt->lock);
for (bio = pkt->orig_bios; bio; bio = bio->bi_next) {
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);
BUG_ON(first_frame < 0);
BUG_ON(first_frame + num_frames > pkt->frames);
for (f = first_frame; f < first_frame + num_frames; f++)
written[f] = 1;
}
spin_unlock(&pkt->lock);
if (pkt->cache_valid) {
VPRINTK("pkt_gather_data: zone %llx cached\n",
(unsigned long long)pkt->sector);
goto out_account;
}
/*
* Schedule reads for missing parts of the packet.
*/
for (f = 0; f < pkt->frames; f++) {
struct bio_vec *vec;
int p, offset;
if (written[f])
continue;
bio = pkt->r_bios[f];
vec = bio->bi_io_vec;
bio_init(bio);
bio->bi_max_vecs = 1;
bio->bi_sector = pkt->sector + f * (CD_FRAMESIZE >> 9);
bio->bi_bdev = pd->bdev;
bio->bi_end_io = pkt_end_io_read;
bio->bi_private = pkt;
bio->bi_io_vec = vec;
bio->bi_destructor = pkt_bio_destructor;
p = (f * CD_FRAMESIZE) / PAGE_SIZE;
offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
VPRINTK("pkt_gather_data: Adding frame %d, page:%p offs:%d\n",
f, pkt->pages[p], offset);
if (!bio_add_page(bio, pkt->pages[p], CD_FRAMESIZE, offset))
BUG();
atomic_inc(&pkt->io_wait);
bio->bi_rw = READ;
pkt_queue_bio(pd, bio);
frames_read++;
}
out_account:
VPRINTK("pkt_gather_data: need %d frames for zone %llx\n",
frames_read, (unsigned long long)pkt->sector);
pd->stats.pkt_started++;
pd->stats.secs_rg += frames_read * (CD_FRAMESIZE >> 9);
}
/*
* Find a packet matching zone, or the least recently used packet if
* there is no match.
*/
static struct packet_data *pkt_get_packet_data(struct pktcdvd_device *pd, int zone)
{
struct packet_data *pkt;
list_for_each_entry(pkt, &pd->cdrw.pkt_free_list, list) {
if (pkt->sector == zone || pkt->list.next == &pd->cdrw.pkt_free_list) {
list_del_init(&pkt->list);
if (pkt->sector != zone)
pkt->cache_valid = 0;
return pkt;
}
}
BUG();
return NULL;
}
static void pkt_put_packet_data(struct pktcdvd_device *pd, struct packet_data *pkt)
{
if (pkt->cache_valid) {
list_add(&pkt->list, &pd->cdrw.pkt_free_list);
} else {
list_add_tail(&pkt->list, &pd->cdrw.pkt_free_list);
}
}
/*
* recover a failed write, query for relocation if possible
*
* returns 1 if recovery is possible, or 0 if not
*
*/
static int pkt_start_recovery(struct packet_data *pkt)
{
/*
* FIXME. We need help from the file system to implement
* recovery handling.
*/
return 0;
#if 0
struct request *rq = pkt->rq;
struct pktcdvd_device *pd = rq->rq_disk->private_data;
struct block_device *pkt_bdev;
struct super_block *sb = NULL;
unsigned long old_block, new_block;
sector_t new_sector;
pkt_bdev = bdget(kdev_t_to_nr(pd->pkt_dev));
if (pkt_bdev) {
sb = get_super(pkt_bdev);
bdput(pkt_bdev);
}
if (!sb)
return 0;
if (!sb->s_op || !sb->s_op->relocate_blocks)
goto out;
old_block = pkt->sector / (CD_FRAMESIZE >> 9);
if (sb->s_op->relocate_blocks(sb, old_block, &new_block))
goto out;
new_sector = new_block * (CD_FRAMESIZE >> 9);
pkt->sector = new_sector;
pkt->bio->bi_sector = new_sector;
pkt->bio->bi_next = NULL;
pkt->bio->bi_flags = 1 << BIO_UPTODATE;
pkt->bio->bi_idx = 0;
BUG_ON(pkt->bio->bi_rw != (1 << BIO_RW));
BUG_ON(pkt->bio->bi_vcnt != pkt->frames);
BUG_ON(pkt->bio->bi_size != pkt->frames * CD_FRAMESIZE);
BUG_ON(pkt->bio->bi_end_io != pkt_end_io_packet_write);
BUG_ON(pkt->bio->bi_private != pkt);
drop_super(sb);
return 1;
out:
drop_super(sb);
return 0;
#endif
}
static inline void pkt_set_state(struct packet_data *pkt, enum packet_data_state state)
{
#if PACKET_DEBUG > 1
static const char *state_name[] = {
"IDLE", "WAITING", "READ_WAIT", "WRITE_WAIT", "RECOVERY", "FINISHED"
};
enum packet_data_state old_state = pkt->state;
VPRINTK("pkt %2d : s=%6llx %s -> %s\n", pkt->id, (unsigned long long)pkt->sector,
state_name[old_state], state_name[state]);
#endif
pkt->state = state;
}
/*
* Scan the work queue to see if we can start a new packet.
* returns non-zero if any work was done.
*/
static int pkt_handle_queue(struct pktcdvd_device *pd)
{
struct packet_data *pkt, *p;
struct bio *bio = NULL;
sector_t zone = 0; /* Suppress gcc warning */
struct pkt_rb_node *node, *first_node;
struct rb_node *n;
int wakeup;
VPRINTK("handle_queue\n");
atomic_set(&pd->scan_queue, 0);
if (list_empty(&pd->cdrw.pkt_free_list)) {
VPRINTK("handle_queue: no pkt\n");
return 0;
}
/*
* Try to find a zone we are not already working on.
*/
spin_lock(&pd->lock);
first_node = pkt_rbtree_find(pd, pd->current_sector);
if (!first_node) {
n = rb_first(&pd->bio_queue);
if (n)
first_node = rb_entry(n, struct pkt_rb_node, rb_node);
}
node = first_node;
while (node) {
bio = node->bio;
zone = ZONE(bio->bi_sector, pd);
list_for_each_entry(p, &pd->cdrw.pkt_active_list, list) {
if (p->sector == zone) {
bio = NULL;
goto try_next_bio;
}
}
break;
try_next_bio:
node = pkt_rbtree_next(node);
if (!node) {
n = rb_first(&pd->bio_queue);
if (n)
node = rb_entry(n, struct pkt_rb_node, rb_node);
}
if (node == first_node)
node = NULL;
}
spin_unlock(&pd->lock);
if (!bio) {
VPRINTK("handle_queue: no bio\n");
return 0;
}
pkt = pkt_get_packet_data(pd, zone);
pd->current_sector = zone + pd->settings.size;
pkt->sector = zone;
BUG_ON(pkt->frames != pd->settings.size >> 2);
pkt->write_size = 0;
/*
* Scan work queue for bios in the same zone and link them
* to this packet.
*/
spin_lock(&pd->lock);
VPRINTK("pkt_handle_queue: looking for zone %llx\n", (unsigned long long)zone);
while ((node = pkt_rbtree_find(pd, zone)) != NULL) {
bio = node->bio;
VPRINTK("pkt_handle_queue: found zone=%llx\n",
(unsigned long long)ZONE(bio->bi_sector, pd));
if (ZONE(bio->bi_sector, pd) != zone)
break;
pkt_rbtree_erase(pd, node);
spin_lock(&pkt->lock);
pkt_add_list_last(bio, &pkt->orig_bios, &pkt->orig_bios_tail);
pkt->write_size += bio->bi_size / CD_FRAMESIZE;
spin_unlock(&pkt->lock);
}
/* check write congestion marks, and if bio_queue_size is
below, wake up any waiters */
wakeup = (pd->write_congestion_on > 0
&& pd->bio_queue_size <= pd->write_congestion_off);
spin_unlock(&pd->lock);
if (wakeup)
clear_bdi_congested(&pd->disk->queue->backing_dev_info, WRITE);
pkt->sleep_time = max(PACKET_WAIT_TIME, 1);
pkt_set_state(pkt, PACKET_WAITING_STATE);
atomic_set(&pkt->run_sm, 1);
spin_lock(&pd->cdrw.active_list_lock);
list_add(&pkt->list, &pd->cdrw.pkt_active_list);
spin_unlock(&pd->cdrw.active_list_lock);
return 1;
}
/*
* Assemble a bio to write one packet and queue the bio for processing
* by the underlying block device.
*/
static void pkt_start_write(struct pktcdvd_device *pd, struct packet_data *pkt)
{
struct bio *bio;
int f;
int frames_write;
struct bio_vec *bvec = pkt->w_bio->bi_io_vec;
for (f = 0; f < pkt->frames; f++) {
bvec[f].bv_page = pkt->pages[(f * CD_FRAMESIZE) / PAGE_SIZE];
bvec[f].bv_offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
}
/*
* Fill-in bvec with data from orig_bios.
*/
frames_write = 0;
spin_lock(&pkt->lock);
for (bio = pkt->orig_bios; bio; bio = bio->bi_next) {
int segment = bio->bi_idx;
int src_offs = 0;
int first_frame = (bio->bi_sector - pkt->sector) / (CD_FRAMESIZE >> 9);
int num_frames = bio->bi_size / CD_FRAMESIZE;
BUG_ON(first_frame < 0);
BUG_ON(first_frame + num_frames > pkt->frames);
for (f = first_frame; f < first_frame + num_frames; f++) {
struct bio_vec *src_bvl = bio_iovec_idx(bio, segment);
while (src_offs >= src_bvl->bv_len) {
src_offs -= src_bvl->bv_len;
segment++;
BUG_ON(segment >= bio->bi_vcnt);
src_bvl = bio_iovec_idx(bio, segment);
}
if (src_bvl->bv_len - src_offs >= CD_FRAMESIZE) {
bvec[f].bv_page = src_bvl->bv_page;
bvec[f].bv_offset = src_bvl->bv_offset + src_offs;
} else {
pkt_copy_bio_data(bio, segment, src_offs,
bvec[f].bv_page, bvec[f].bv_offset);
}
src_offs += CD_FRAMESIZE;
frames_write++;
}
}
pkt_set_state(pkt, PACKET_WRITE_WAIT_STATE);
spin_unlock(&pkt->lock);
VPRINTK("pkt_start_write: Writing %d frames for zone %llx\n",
frames_write, (unsigned long long)pkt->sector);
BUG_ON(frames_write != pkt->write_size);
if (test_bit(PACKET_MERGE_SEGS, &pd->flags) || (pkt->write_size < pkt->frames)) {
pkt_make_local_copy(pkt, bvec);
pkt->cache_valid = 1;
} else {
pkt->cache_valid = 0;
}
/* Start the write request */
bio_init(pkt->w_bio);
pkt->w_bio->bi_max_vecs = PACKET_MAX_SIZE;
pkt->w_bio->bi_sector = pkt->sector;
pkt->w_bio->bi_bdev = pd->bdev;
pkt->w_bio->bi_end_io = pkt_end_io_packet_write;
pkt->w_bio->bi_private = pkt;
pkt->w_bio->bi_io_vec = bvec;
pkt->w_bio->bi_destructor = pkt_bio_destructor;
for (f = 0; f < pkt->frames; f++)
if (!bio_add_page(pkt->w_bio, bvec[f].bv_page, CD_FRAMESIZE, bvec[f].bv_offset))
BUG();
VPRINTK(DRIVER_NAME": vcnt=%d\n", pkt->w_bio->bi_vcnt);
atomic_set(&pkt->io_wait, 1);
pkt->w_bio->bi_rw = WRITE;
pkt_queue_bio(pd, pkt->w_bio);
}
static void pkt_finish_packet(struct packet_data *pkt, int uptodate)
{
struct bio *bio, *next;
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;
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)
{
int uptodate;
VPRINTK("run_state_machine: pkt %d\n", pkt->id);
for (;;) {
switch (pkt->state) {
case PACKET_WAITING_STATE:
if ((pkt->write_size < pkt->frames) && (pkt->sleep_time > 0))
return;
pkt->sleep_time = 0;
pkt_gather_data(pd, pkt);
pkt_set_state(pkt, PACKET_READ_WAIT_STATE);
break;
case PACKET_READ_WAIT_STATE:
if (atomic_read(&pkt->io_wait) > 0)
return;
if (atomic_read(&pkt->io_errors) > 0) {
pkt_set_state(pkt, PACKET_RECOVERY_STATE);
} else {
pkt_start_write(pd, pkt);
}
break;
case PACKET_WRITE_WAIT_STATE:
if (atomic_read(&pkt->io_wait) > 0)
return;
if (test_bit(BIO_UPTODATE, &pkt->w_bio->bi_flags)) {
pkt_set_state(pkt, PACKET_FINISHED_STATE);
} else {
pkt_set_state(pkt, PACKET_RECOVERY_STATE);
}
break;
case PACKET_RECOVERY_STATE:
if (pkt_start_recovery(pkt)) {
pkt_start_write(pd, pkt);
} else {
VPRINTK("No recovery possible\n");
pkt_set_state(pkt, PACKET_FINISHED_STATE);
}
break;
case PACKET_FINISHED_STATE:
uptodate = test_bit(BIO_UPTODATE, &pkt->w_bio->bi_flags);
pkt_finish_packet(pkt, uptodate);
return;
default:
BUG();
break;
}
}
}
static void pkt_handle_packets(struct pktcdvd_device *pd)
{
struct packet_data *pkt, *next;
VPRINTK("pkt_handle_packets\n");
/*
* Run state machine for active packets
*/
list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
if (atomic_read(&pkt->run_sm) > 0) {
atomic_set(&pkt->run_sm, 0);
pkt_run_state_machine(pd, pkt);
}
}
/*
* Move no longer active packets to the free list
*/
spin_lock(&pd->cdrw.active_list_lock);
list_for_each_entry_safe(pkt, next, &pd->cdrw.pkt_active_list, list) {
if (pkt->state == PACKET_FINISHED_STATE) {
list_del(&pkt->list);
pkt_put_packet_data(pd, pkt);
pkt_set_state(pkt, PACKET_IDLE_STATE);
atomic_set(&pd->scan_queue, 1);
}
}
spin_unlock(&pd->cdrw.active_list_lock);
}
static void pkt_count_states(struct pktcdvd_device *pd, int *states)
{
struct packet_data *pkt;
int i;
for (i = 0; i < PACKET_NUM_STATES; i++)
states[i] = 0;
spin_lock(&pd->cdrw.active_list_lock);
list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
states[pkt->state]++;
}
spin_unlock(&pd->cdrw.active_list_lock);
}
/*
* kcdrwd is woken up when writes have been queued for one of our
* registered devices
*/
static int kcdrwd(void *foobar)
{
struct pktcdvd_device *pd = foobar;
struct packet_data *pkt;
long min_sleep_time, residue;
set_user_nice(current, -20);
set_freezable();
for (;;) {
DECLARE_WAITQUEUE(wait, current);
/*
* Wait until there is something to do
*/
add_wait_queue(&pd->wqueue, &wait);
for (;;) {
set_current_state(TASK_INTERRUPTIBLE);
/* Check if we need to run pkt_handle_queue */
if (atomic_read(&pd->scan_queue) > 0)
goto work_to_do;
/* Check if we need to run the state machine for some packet */
list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
if (atomic_read(&pkt->run_sm) > 0)
goto work_to_do;
}
/* Check if we need to process the iosched queues */
if (atomic_read(&pd->iosched.attention) != 0)
goto work_to_do;
/* Otherwise, go to sleep */
if (PACKET_DEBUG > 1) {
int states[PACKET_NUM_STATES];
pkt_count_states(pd, states);
VPRINTK("kcdrwd: i:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
states[0], states[1], states[2], states[3],
states[4], states[5]);
}
min_sleep_time = MAX_SCHEDULE_TIMEOUT;
list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
if (pkt->sleep_time && pkt->sleep_time < min_sleep_time)
min_sleep_time = pkt->sleep_time;
}
generic_unplug_device(bdev_get_queue(pd->bdev));
VPRINTK("kcdrwd: sleeping\n");
residue = schedule_timeout(min_sleep_time);
VPRINTK("kcdrwd: wake up\n");
/* make swsusp happy with our thread */
try_to_freeze();
list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
if (!pkt->sleep_time)
continue;
pkt->sleep_time -= min_sleep_time - residue;
if (pkt->sleep_time <= 0) {
pkt->sleep_time = 0;
atomic_inc(&pkt->run_sm);
}
}
if (kthread_should_stop())
break;
}
work_to_do:
set_current_state(TASK_RUNNING);
remove_wait_queue(&pd->wqueue, &wait);
if (kthread_should_stop())
break;
/*
* if pkt_handle_queue returns true, we can queue
* another request.
*/
while (pkt_handle_queue(pd))
;
/*
* Handle packet state machine
*/
pkt_handle_packets(pd);
/*
* Handle iosched queues
*/
pkt_iosched_process_queue(pd);
}
return 0;
}
static void pkt_print_settings(struct pktcdvd_device *pd)
{
printk(DRIVER_NAME": %s packets, ", pd->settings.fp ? "Fixed" : "Variable");
printk("%u blocks, ", pd->settings.size >> 2);
printk("Mode-%c disc\n", pd->settings.block_mode == 8 ? '1' : '2');
}
static int pkt_mode_sense(struct pktcdvd_device *pd, struct packet_command *cgc, int page_code, int page_control)
{
memset(cgc->cmd, 0, sizeof(cgc->cmd));
cgc->cmd[0] = GPCMD_MODE_SENSE_10;
cgc->cmd[2] = page_code | (page_control << 6);
cgc->cmd[7] = cgc->buflen >> 8;
cgc->cmd[8] = cgc->buflen & 0xff;
cgc->data_direction = CGC_DATA_READ;
return pkt_generic_packet(pd, cgc);
}
static int pkt_mode_select(struct pktcdvd_device *pd, struct packet_command *cgc)
{
memset(cgc->cmd, 0, sizeof(cgc->cmd));
memset(cgc->buffer, 0, 2);
cgc->cmd[0] = GPCMD_MODE_SELECT_10;
cgc->cmd[1] = 0x10; /* PF */
cgc->cmd[7] = cgc->buflen >> 8;
cgc->cmd[8] = cgc->buflen & 0xff;
cgc->data_direction = CGC_DATA_WRITE;
return pkt_generic_packet(pd, cgc);
}
static int pkt_get_disc_info(struct pktcdvd_device *pd, disc_information *di)
{
struct packet_command cgc;
int ret;
/* set up command and get the disc info */
init_cdrom_command(&cgc, di, sizeof(*di), CGC_DATA_READ);
cgc.cmd[0] = GPCMD_READ_DISC_INFO;
cgc.cmd[8] = cgc.buflen = 2;
cgc.quiet = 1;
if ((ret = pkt_generic_packet(pd, &cgc)))
return ret;
/* not all drives have the same disc_info length, so requeue
* packet with the length the drive tells us it can supply
*/
cgc.buflen = be16_to_cpu(di->disc_information_length) +
sizeof(di->disc_information_length);
if (cgc.buflen > sizeof(disc_information))
cgc.buflen = sizeof(disc_information);
cgc.cmd[8] = cgc.buflen;
return pkt_generic_packet(pd, &cgc);
}
static int pkt_get_track_info(struct pktcdvd_device *pd, __u16 track, __u8 type, track_information *ti)
{
struct packet_command cgc;
int ret;
init_cdrom_command(&cgc, ti, 8, CGC_DATA_READ);
cgc.cmd[0] = GPCMD_READ_TRACK_RZONE_INFO;
cgc.cmd[1] = type & 3;
cgc.cmd[4] = (track & 0xff00) >> 8;
cgc.cmd[5] = track & 0xff;
cgc.cmd[8] = 8;
cgc.quiet = 1;
if ((ret = pkt_generic_packet(pd, &cgc)))
return ret;
cgc.buflen = be16_to_cpu(ti->track_information_length) +
sizeof(ti->track_information_length);
if (cgc.buflen > sizeof(track_information))
cgc.buflen = sizeof(track_information);
cgc.cmd[8] = cgc.buflen;
return pkt_generic_packet(pd, &cgc);
}
static noinline_for_stack int pkt_get_last_written(struct pktcdvd_device *pd,
long *last_written)
{
disc_information di;
track_information ti;
__u32 last_track;
int ret = -1;
if ((ret = pkt_get_disc_info(pd, &di)))
return ret;
last_track = (di.last_track_msb << 8) | di.last_track_lsb;
if ((ret = pkt_get_track_info(pd, last_track, 1, &ti)))
return ret;
/* if this track is blank, try the previous. */
if (ti.blank) {
last_track--;
if ((ret = pkt_get_track_info(pd, last_track, 1, &ti)))
return ret;
}
/* if last recorded field is valid, return it. */
if (ti.lra_v) {
*last_written = be32_to_cpu(ti.last_rec_address);
} else {
/* make it up instead */
*last_written = be32_to_cpu(ti.track_start) +
be32_to_cpu(ti.track_size);
if (ti.free_blocks)
*last_written -= (be32_to_cpu(ti.free_blocks) + 7);
}
return 0;
}
/*
* write mode select package based on pd->settings
*/
static noinline_for_stack int pkt_set_write_settings(struct pktcdvd_device *pd)
{
struct packet_command cgc;
struct request_sense sense;
write_param_page *wp;
char buffer[128];
int ret, size;
/* doesn't apply to DVD+RW or DVD-RAM */
if ((pd->mmc3_profile == 0x1a) || (pd->mmc3_profile == 0x12))
return 0;
memset(buffer, 0, sizeof(buffer));
init_cdrom_command(&cgc, buffer, sizeof(*wp), CGC_DATA_READ);
cgc.sense = &sense;
if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0))) {
pkt_dump_sense(&cgc);
return ret;
}
size = 2 + ((buffer[0] << 8) | (buffer[1] & 0xff));
pd->mode_offset = (buffer[6] << 8) | (buffer[7] & 0xff);
if (size > sizeof(buffer))
size = sizeof(buffer);
/*
* now get it all
*/
init_cdrom_command(&cgc, buffer, size, CGC_DATA_READ);
cgc.sense = &sense;
if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0))) {
pkt_dump_sense(&cgc);
return ret;
}
/*
* write page is offset header + block descriptor length
*/
wp = (write_param_page *) &buffer[sizeof(struct mode_page_header) + pd->mode_offset];
wp->fp = pd->settings.fp;
wp->track_mode = pd->settings.track_mode;
wp->write_type = pd->settings.write_type;
wp->data_block_type = pd->settings.block_mode;
wp->multi_session = 0;
#ifdef PACKET_USE_LS
wp->link_size = 7;
wp->ls_v = 1;
#endif
if (wp->data_block_type == PACKET_BLOCK_MODE1) {
wp->session_format = 0;
wp->subhdr2 = 0x20;
} else if (wp->data_block_type == PACKET_BLOCK_MODE2) {
wp->session_format = 0x20;
wp->subhdr2 = 8;
#if 0
wp->mcn[0] = 0x80;
memcpy(&wp->mcn[1], PACKET_MCN, sizeof(wp->mcn) - 1);
#endif
} else {
/*
* paranoia
*/
printk(DRIVER_NAME": write mode wrong %d\n", wp->data_block_type);
return 1;
}
wp->packet_size = cpu_to_be32(pd->settings.size >> 2);
cgc.buflen = cgc.cmd[8] = size;
if ((ret = pkt_mode_select(pd, &cgc))) {
pkt_dump_sense(&cgc);
return ret;
}
pkt_print_settings(pd);
return 0;
}
/*
* 1 -- we can write to this track, 0 -- we can't
*/
static int pkt_writable_track(struct pktcdvd_device *pd, track_information *ti)
{
switch (pd->mmc3_profile) {
case 0x1a: /* DVD+RW */
case 0x12: /* DVD-RAM */
/* The track is always writable on DVD+RW/DVD-RAM */
return 1;
default:
break;
}
if (!ti->packet || !ti->fp)
return 0;
/*
* "good" settings as per Mt Fuji.
*/
if (ti->rt == 0 && ti->blank == 0)
return 1;
if (ti->rt == 0 && ti->blank == 1)
return 1;
if (ti->rt == 1 && ti->blank == 0)
return 1;
printk(DRIVER_NAME": bad state %d-%d-%d\n", ti->rt, ti->blank, ti->packet);
return 0;
}
/*
* 1 -- we can write to this disc, 0 -- we can't
*/
static int pkt_writable_disc(struct pktcdvd_device *pd, disc_information *di)
{
switch (pd->mmc3_profile) {
case 0x0a: /* CD-RW */
case 0xffff: /* MMC3 not supported */
break;
case 0x1a: /* DVD+RW */
case 0x13: /* DVD-RW */
case 0x12: /* DVD-RAM */
return 1;
default:
VPRINTK(DRIVER_NAME": Wrong disc profile (%x)\n", pd->mmc3_profile);
return 0;
}
/*
* for disc type 0xff we should probably reserve a new track.
* but i'm not sure, should we leave this to user apps? probably.
*/
if (di->disc_type == 0xff) {
printk(DRIVER_NAME": Unknown disc. No track?\n");
return 0;
}
if (di->disc_type != 0x20 && di->disc_type != 0) {
printk(DRIVER_NAME": Wrong disc type (%x)\n", di->disc_type);
return 0;
}
if (di->erasable == 0) {
printk(DRIVER_NAME": Disc not erasable\n");
return 0;
}
if (di->border_status == PACKET_SESSION_RESERVED) {
printk(DRIVER_NAME": Can't write to last track (reserved)\n");
return 0;
}
return 1;
}
static noinline_for_stack int pkt_probe_settings(struct pktcdvd_device *pd)
{
struct packet_command cgc;
unsigned char buf[12];
disc_information di;
track_information ti;
int ret, track;
init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
cgc.cmd[0] = GPCMD_GET_CONFIGURATION;
cgc.cmd[8] = 8;
ret = pkt_generic_packet(pd, &cgc);
pd->mmc3_profile = ret ? 0xffff : buf[6] << 8 | buf[7];
memset(&di, 0, sizeof(disc_information));
memset(&ti, 0, sizeof(track_information));
if ((ret = pkt_get_disc_info(pd, &di))) {
printk("failed get_disc\n");
return ret;
}
if (!pkt_writable_disc(pd, &di))
return -EROFS;
pd->type = di.erasable ? PACKET_CDRW : PACKET_CDR;
track = 1; /* (di.last_track_msb << 8) | di.last_track_lsb; */
if ((ret = pkt_get_track_info(pd, track, 1, &ti))) {
printk(DRIVER_NAME": failed get_track\n");
return ret;
}
if (!pkt_writable_track(pd, &ti)) {
printk(DRIVER_NAME": can't write to this track\n");
return -EROFS;
}
/*
* we keep packet size in 512 byte units, makes it easier to
* deal with request calculations.
*/
pd->settings.size = be32_to_cpu(ti.fixed_packet_size) << 2;
if (pd->settings.size == 0) {
printk(DRIVER_NAME": detected zero packet size!\n");
return -ENXIO;
}
if (pd->settings.size > PACKET_MAX_SECTORS) {
printk(DRIVER_NAME": packet size is too big\n");
return -EROFS;
}
pd->settings.fp = ti.fp;
pd->offset = (be32_to_cpu(ti.track_start) << 2) & (pd->settings.size - 1);
if (ti.nwa_v) {
pd->nwa = be32_to_cpu(ti.next_writable);
set_bit(PACKET_NWA_VALID, &pd->flags);
}
/*
* in theory we could use lra on -RW media as well and just zero
* blocks that haven't been written yet, but in practice that
* is just a no-go. we'll use that for -R, naturally.
*/
if (ti.lra_v) {
pd->lra = be32_to_cpu(ti.last_rec_address);
set_bit(PACKET_LRA_VALID, &pd->flags);
} else {
pd->lra = 0xffffffff;
set_bit(PACKET_LRA_VALID, &pd->flags);
}
/*
* fine for now
*/
pd->settings.link_loss = 7;
pd->settings.write_type = 0; /* packet */
pd->settings.track_mode = ti.track_mode;
/*
* mode1 or mode2 disc
*/
switch (ti.data_mode) {
case PACKET_MODE1:
pd->settings.block_mode = PACKET_BLOCK_MODE1;
break;
case PACKET_MODE2:
pd->settings.block_mode = PACKET_BLOCK_MODE2;
break;
default:
printk(DRIVER_NAME": unknown data mode\n");
return -EROFS;
}
return 0;
}
/*
* enable/disable write caching on drive
*/
static noinline_for_stack int pkt_write_caching(struct pktcdvd_device *pd,
int set)
{
struct packet_command cgc;
struct request_sense sense;
unsigned char buf[64];
int ret;
memset(buf, 0, sizeof(buf));
init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
cgc.sense = &sense;
cgc.buflen = pd->mode_offset + 12;
/*
* caching mode page might not be there, so quiet this command
*/
cgc.quiet = 1;
if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WCACHING_PAGE, 0)))
return ret;
buf[pd->mode_offset + 10] |= (!!set << 2);
cgc.buflen = cgc.cmd[8] = 2 + ((buf[0] << 8) | (buf[1] & 0xff));
ret = pkt_mode_select(pd, &cgc);
if (ret) {
printk(DRIVER_NAME": write caching control failed\n");
pkt_dump_sense(&cgc);
} else if (!ret && set)
printk(DRIVER_NAME": enabled write caching on %s\n", pd->name);
return ret;
}
static int pkt_lock_door(struct pktcdvd_device *pd, int lockflag)
{
struct packet_command cgc;
init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
cgc.cmd[0] = GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL;
cgc.cmd[4] = lockflag ? 1 : 0;
return pkt_generic_packet(pd, &cgc);
}
/*
* Returns drive maximum write speed
*/
static noinline_for_stack int pkt_get_max_speed(struct pktcdvd_device *pd,
unsigned *write_speed)
{
struct packet_command cgc;
struct request_sense sense;
unsigned char buf[256+18];
unsigned char *cap_buf;
int ret, offset;
memset(buf, 0, sizeof(buf));
cap_buf = &buf[sizeof(struct mode_page_header) + pd->mode_offset];
init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_UNKNOWN);
cgc.sense = &sense;
ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
if (ret) {
cgc.buflen = pd->mode_offset + cap_buf[1] + 2 +
sizeof(struct mode_page_header);
ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
if (ret) {
pkt_dump_sense(&cgc);
return ret;
}
}
offset = 20; /* Obsoleted field, used by older drives */
if (cap_buf[1] >= 28)
offset = 28; /* Current write speed selected */
if (cap_buf[1] >= 30) {
/* If the drive reports at least one "Logical Unit Write
* Speed Performance Descriptor Block", use the information
* in the first block. (contains the highest speed)
*/
int num_spdb = (cap_buf[30] << 8) + cap_buf[31];
if (num_spdb > 0)
offset = 34;
}
*write_speed = (cap_buf[offset] << 8) | cap_buf[offset + 1];
return 0;
}
/* These tables from cdrecord - I don't have orange book */
/* standard speed CD-RW (1-4x) */
static char clv_to_speed[16] = {
/* 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 */
0, 2, 4, 6, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
/* high speed CD-RW (-10x) */
static char hs_clv_to_speed[16] = {
/* 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 */
0, 2, 4, 6, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
/* ultra high speed CD-RW */
static char us_clv_to_speed[16] = {
/* 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 */
0, 2, 4, 8, 0, 0,16, 0,24,32,40,48, 0, 0, 0, 0
};
/*
* reads the maximum media speed from ATIP
*/
static noinline_for_stack int pkt_media_speed(struct pktcdvd_device *pd,
unsigned *speed)
{
struct packet_command cgc;
struct request_sense sense;
unsigned char buf[64];
unsigned int size, st, sp;
int ret;
init_cdrom_command(&cgc, buf, 2, CGC_DATA_READ);
cgc.sense = &sense;
cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
cgc.cmd[1] = 2;
cgc.cmd[2] = 4; /* READ ATIP */
cgc.cmd[8] = 2;
ret = pkt_generic_packet(pd, &cgc);
if (ret) {
pkt_dump_sense(&cgc);
return ret;
}
size = ((unsigned int) buf[0]<<8) + buf[1] + 2;
if (size > sizeof(buf))
size = sizeof(buf);
init_cdrom_command(&cgc, buf, size, CGC_DATA_READ);
cgc.sense = &sense;
cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
cgc.cmd[1] = 2;
cgc.cmd[2] = 4;
cgc.cmd[8] = size;
ret = pkt_generic_packet(pd, &cgc);
if (ret) {
pkt_dump_sense(&cgc);
return ret;
}
if (!(buf[6] & 0x40)) {
printk(DRIVER_NAME": Disc type is not CD-RW\n");
return 1;
}
if (!(buf[6] & 0x4)) {
printk(DRIVER_NAME": A1 values on media are not valid, maybe not CDRW?\n");
return 1;
}
st = (buf[6] >> 3) & 0x7; /* disc sub-type */
sp = buf[16] & 0xf; /* max speed from ATIP A1 field */
/* Info from cdrecord */
switch (st) {
case 0: /* standard speed */
*speed = clv_to_speed[sp];
break;
case 1: /* high speed */
*speed = hs_clv_to_speed[sp];
break;
case 2: /* ultra high speed */
*speed = us_clv_to_speed[sp];
break;
default:
printk(DRIVER_NAME": Unknown disc sub-type %d\n",st);
return 1;
}
if (*speed) {
printk(DRIVER_NAME": Max. media speed: %d\n",*speed);
return 0;
} else {
printk(DRIVER_NAME": Unknown speed %d for sub-type %d\n",sp,st);
return 1;
}
}
static noinline_for_stack int pkt_perform_opc(struct pktcdvd_device *pd)
{
struct packet_command cgc;
struct request_sense sense;
int ret;
VPRINTK(DRIVER_NAME": Performing OPC\n");
init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
cgc.sense = &sense;
cgc.timeout = 60*HZ;
cgc.cmd[0] = GPCMD_SEND_OPC;
cgc.cmd[1] = 1;
if ((ret = pkt_generic_packet(pd, &cgc)))
pkt_dump_sense(&cgc);
return ret;
}
static int pkt_open_write(struct pktcdvd_device *pd)
{
int ret;
unsigned int write_speed, media_write_speed, read_speed;
if ((ret = pkt_probe_settings(pd))) {
VPRINTK(DRIVER_NAME": %s failed probe\n", pd->name);
return ret;
}
if ((ret = pkt_set_write_settings(pd))) {
DPRINTK(DRIVER_NAME": %s failed saving write settings\n", pd->name);
return -EIO;
}
pkt_write_caching(pd, USE_WCACHING);
if ((ret = pkt_get_max_speed(pd, &write_speed)))
write_speed = 16 * 177;
switch (pd->mmc3_profile) {
case 0x13: /* DVD-RW */
case 0x1a: /* DVD+RW */
case 0x12: /* DVD-RAM */
DPRINTK(DRIVER_NAME": write speed %ukB/s\n", write_speed);
break;
default:
if ((ret = pkt_media_speed(pd, &media_write_speed)))
media_write_speed = 16;
write_speed = min(write_speed, media_write_speed * 177);
DPRINTK(DRIVER_NAME": write speed %ux\n", write_speed / 176);
break;
}
read_speed = write_speed;
if ((ret = pkt_set_speed(pd, write_speed, read_speed))) {
DPRINTK(DRIVER_NAME": %s couldn't set write speed\n", pd->name);
return -EIO;
}
pd->write_speed = write_speed;
pd->read_speed = read_speed;
if ((ret = pkt_perform_opc(pd))) {
DPRINTK(DRIVER_NAME": %s Optimum Power Calibration failed\n", pd->name);
}
return 0;
}
/*
* called at open time.
*/
static int pkt_open_dev(struct pktcdvd_device *pd, int write)
{
int ret;
long lba;
struct request_queue *q;
/*
* We need to re-open the cdrom device without O_NONBLOCK to be able
* to read/write from/to it. It is already opened in O_NONBLOCK mode
* so bdget() can't fail.
*/
bdget(pd->bdev->bd_dev);
if ((ret = blkdev_get(pd->bdev, FMODE_READ, O_RDONLY)))
goto out;
if ((ret = bd_claim(pd->bdev, pd)))
goto out_putdev;
if ((ret = pkt_get_last_written(pd, &lba))) {
printk(DRIVER_NAME": pkt_get_last_written failed\n");
goto out_unclaim;
}
set_capacity(pd->disk, lba << 2);
set_capacity(pd->bdev->bd_disk, lba << 2);
bd_set_size(pd->bdev, (loff_t)lba << 11);
q = bdev_get_queue(pd->bdev);
if (write) {
if ((ret = pkt_open_write(pd)))
goto out_unclaim;
/*
* Some CDRW drives can not handle writes larger than one packet,
* even if the size is a multiple of the packet size.
*/
spin_lock_irq(q->queue_lock);
blk_queue_max_sectors(q, pd->settings.size);
spin_unlock_irq(q->queue_lock);
set_bit(PACKET_WRITABLE, &pd->flags);
} else {
pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
clear_bit(PACKET_WRITABLE, &pd->flags);
}
if ((ret = pkt_set_segment_merging(pd, q)))
goto out_unclaim;
if (write) {
if (!pkt_grow_pktlist(pd, CONFIG_CDROM_PKTCDVD_BUFFERS)) {
printk(DRIVER_NAME": not enough memory for buffers\n");
ret = -ENOMEM;
goto out_unclaim;
}
printk(DRIVER_NAME": %lukB available on disc\n", lba << 1);
}
return 0;
out_unclaim:
bd_release(pd->bdev);
out_putdev:
blkdev_put(pd->bdev);
out:
return ret;
}
/*
* called when the device is closed. makes sure that the device flushes
* the internal cache before we close.
*/
static void pkt_release_dev(struct pktcdvd_device *pd, int flush)
{
if (flush && pkt_flush_cache(pd))
DPRINTK(DRIVER_NAME": %s not flushing cache\n", pd->name);
pkt_lock_door(pd, 0);
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)
{
if (dev_minor >= MAX_WRITERS)
return NULL;
return pkt_devs[dev_minor];
}
static int pkt_open(struct inode *inode, struct file *file)
{
struct pktcdvd_device *pd = NULL;
int ret;
VPRINTK(DRIVER_NAME": entering open\n");
mutex_lock(&ctl_mutex);
pd = pkt_find_dev_from_minor(iminor(inode));
if (!pd) {
ret = -ENODEV;
goto out;
}
BUG_ON(pd->refcnt < 0);
pd->refcnt++;
if (pd->refcnt > 1) {
if ((file->f_mode & FMODE_WRITE) &&
!test_bit(PACKET_WRITABLE, &pd->flags)) {
ret = -EBUSY;
goto out_dec;
}
} else {
ret = pkt_open_dev(pd, file->f_mode & FMODE_WRITE);
if (ret)
goto out_dec;
/*
* needed here as well, since ext2 (among others) may change
* the blocksize at mount time
*/
set_blocksize(inode->i_bdev, CD_FRAMESIZE);
}
mutex_unlock(&ctl_mutex);
return 0;
out_dec:
pd->refcnt--;
out:
VPRINTK(DRIVER_NAME": failed open (%d)\n", ret);
mutex_unlock(&ctl_mutex);
return ret;
}
static int pkt_close(struct inode *inode, struct file *file)
{
struct pktcdvd_device *pd = inode->i_bdev->bd_disk->private_data;
int ret = 0;
mutex_lock(&ctl_mutex);
pd->refcnt--;
BUG_ON(pd->refcnt < 0);
if (pd->refcnt == 0) {
int flush = test_bit(PACKET_WRITABLE, &pd->flags);
pkt_release_dev(pd, flush);
}
mutex_unlock(&ctl_mutex);
return ret;
}
static void pkt_end_io_read_cloned(struct bio *bio, int err)
{
struct packet_stacked_data *psd = bio->bi_private;
struct pktcdvd_device *pd = psd->pd;
bio_put(bio);
bio_endio(psd->bio, err);
mempool_free(psd, psd_pool);
pkt_bio_finished(pd);
}
static int pkt_make_request(struct request_queue *q, struct bio *bio)
{
struct pktcdvd_device *pd;
char b[BDEVNAME_SIZE];
sector_t zone;
struct packet_data *pkt;
int was_empty, blocked_bio;
struct pkt_rb_node *node;
pd = q->queuedata;
if (!pd) {
printk(DRIVER_NAME": %s incorrect request queue\n", bdevname(bio->bi_bdev, b));
goto end_io;
}
/*
* Clone READ bios so we can have our own bi_end_io callback.
*/
if (bio_data_dir(bio) == READ) {
struct bio *cloned_bio = bio_clone(bio, GFP_NOIO);
struct packet_stacked_data *psd = mempool_alloc(psd_pool, GFP_NOIO);
psd->pd = pd;
psd->bio = bio;
cloned_bio->bi_bdev = pd->bdev;
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);
return 0;
}
if (!test_bit(PACKET_WRITABLE, &pd->flags)) {
printk(DRIVER_NAME": WRITE for ro device %s (%llu)\n",
pd->name, (unsigned long long)bio->bi_sector);
goto end_io;
}
if (!bio->bi_size || (bio->bi_size % CD_FRAMESIZE)) {
printk(DRIVER_NAME": wrong bio size\n");
goto end_io;
}
blk_queue_bounce(q, &bio);
zone = ZONE(bio->bi_sector, pd);
VPRINTK("pkt_make_request: start = %6llx stop = %6llx\n",
(unsigned long long)bio->bi_sector,
(unsigned long long)(bio->bi_sector + bio_sectors(bio)));
/* Check if we have to split the bio */
{
struct bio_pair *bp;
sector_t last_zone;
int first_sectors;
last_zone = ZONE(bio->bi_sector + bio_sectors(bio) - 1, pd);
if (last_zone != zone) {
BUG_ON(last_zone != zone + pd->settings.size);
first_sectors = last_zone - bio->bi_sector;
bp = bio_split(bio, bio_split_pool, first_sectors);
BUG_ON(!bp);
pkt_make_request(q, &bp->bio1);
pkt_make_request(q, &bp->bio2);
bio_pair_release(bp);
return 0;
}
}
/*
* If we find a matching packet in state WAITING or READ_WAIT, we can
* just append this bio to that packet.
*/
spin_lock(&pd->cdrw.active_list_lock);
blocked_bio = 0;
list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
if (pkt->sector == zone) {
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);
pkt->write_size += bio->bi_size / CD_FRAMESIZE;
if ((pkt->write_size >= pkt->frames) &&
(pkt->state == PACKET_WAITING_STATE)) {
atomic_inc(&pkt->run_sm);
wake_up(&pd->wqueue);
}
spin_unlock(&pkt->lock);
spin_unlock(&pd->cdrw.active_list_lock);
return 0;
} else {
blocked_bio = 1;
}
spin_unlock(&pkt->lock);
}
}
spin_unlock(&pd->cdrw.active_list_lock);
/*
* Test if there is enough room left in the bio work queue
* (queue size >= congestion on mark).
* If not, wait till the work queue size is below the congestion off mark.
*/
spin_lock(&pd->lock);
if (pd->write_congestion_on > 0
&& pd->bio_queue_size >= pd->write_congestion_on) {
set_bdi_congested(&q->backing_dev_info, WRITE);
do {
spin_unlock(&pd->lock);
congestion_wait(WRITE, HZ);
spin_lock(&pd->lock);
} while(pd->bio_queue_size > pd->write_congestion_off);
}
spin_unlock(&pd->lock);
/*
* No matching packet found. Store the bio in the work queue.
*/
node = mempool_alloc(pd->rb_pool, GFP_NOIO);
node->bio = bio;
spin_lock(&pd->lock);
BUG_ON(pd->bio_queue_size < 0);
was_empty = (pd->bio_queue_size == 0);
pkt_rbtree_insert(pd, node);
spin_unlock(&pd->lock);
/*
* Wake up the worker thread.
*/
atomic_set(&pd->scan_queue, 1);
if (was_empty) {
/* This wake_up is required for correct operation */
wake_up(&pd->wqueue);
} else if (!list_empty(&pd->cdrw.pkt_free_list) && !blocked_bio) {
/*
* This wake up is not required for correct operation,
* but improves performance in some cases.
*/
wake_up(&pd->wqueue);
}
return 0;
end_io:
bio_io_error(bio);
return 0;
}
static int pkt_merge_bvec(struct request_queue *q, struct bio *bio, struct bio_vec *bvec)
{
struct pktcdvd_device *pd = q->queuedata;
sector_t zone = ZONE(bio->bi_sector, pd);
int used = ((bio->bi_sector - zone) << 9) + bio->bi_size;
int remaining = (pd->settings.size << 9) - used;
int remaining2;
/*
* A bio <= PAGE_SIZE must be allowed. If it crosses a packet
* boundary, pkt_make_request() will split the bio.
*/
remaining2 = PAGE_SIZE - bio->bi_size;
remaining = max(remaining, remaining2);
BUG_ON(remaining < 0);
return remaining;
}
static void pkt_init_queue(struct pktcdvd_device *pd)
{
struct request_queue *q = pd->disk->queue;
blk_queue_make_request(q, pkt_make_request);
blk_queue_hardsect_size(q, CD_FRAMESIZE);
blk_queue_max_sectors(q, PACKET_MAX_SECTORS);
blk_queue_merge_bvec(q, pkt_merge_bvec);
q->queuedata = pd;
}
static int pkt_seq_show(struct seq_file *m, void *p)
{
struct pktcdvd_device *pd = m->private;
char *msg;
char bdev_buf[BDEVNAME_SIZE];
int states[PACKET_NUM_STATES];
seq_printf(m, "Writer %s mapped to %s:\n", pd->name,
bdevname(pd->bdev, bdev_buf));
seq_printf(m, "\nSettings:\n");
seq_printf(m, "\tpacket size:\t\t%dkB\n", pd->settings.size / 2);
if (pd->settings.write_type == 0)
msg = "Packet";
else
msg = "Unknown";
seq_printf(m, "\twrite type:\t\t%s\n", msg);
seq_printf(m, "\tpacket type:\t\t%s\n", pd->settings.fp ? "Fixed" : "Variable");
seq_printf(m, "\tlink loss:\t\t%d\n", pd->settings.link_loss);
seq_printf(m, "\ttrack mode:\t\t%d\n", pd->settings.track_mode);
if (pd->settings.block_mode == PACKET_BLOCK_MODE1)
msg = "Mode 1";
else if (pd->settings.block_mode == PACKET_BLOCK_MODE2)
msg = "Mode 2";
else
msg = "Unknown";
seq_printf(m, "\tblock mode:\t\t%s\n", msg);
seq_printf(m, "\nStatistics:\n");
seq_printf(m, "\tpackets started:\t%lu\n", pd->stats.pkt_started);
seq_printf(m, "\tpackets ended:\t\t%lu\n", pd->stats.pkt_ended);
seq_printf(m, "\twritten:\t\t%lukB\n", pd->stats.secs_w >> 1);
seq_printf(m, "\tread gather:\t\t%lukB\n", pd->stats.secs_rg >> 1);
seq_printf(m, "\tread:\t\t\t%lukB\n", pd->stats.secs_r >> 1);
seq_printf(m, "\nMisc:\n");
seq_printf(m, "\treference count:\t%d\n", pd->refcnt);
seq_printf(m, "\tflags:\t\t\t0x%lx\n", pd->flags);
seq_printf(m, "\tread speed:\t\t%ukB/s\n", pd->read_speed);
seq_printf(m, "\twrite speed:\t\t%ukB/s\n", pd->write_speed);
seq_printf(m, "\tstart offset:\t\t%lu\n", pd->offset);
seq_printf(m, "\tmode page offset:\t%u\n", pd->mode_offset);
seq_printf(m, "\nQueue state:\n");
seq_printf(m, "\tbios queued:\t\t%d\n", pd->bio_queue_size);
seq_printf(m, "\tbios pending:\t\t%d\n", atomic_read(&pd->cdrw.pending_bios));
seq_printf(m, "\tcurrent sector:\t\t0x%llx\n", (unsigned long long)pd->current_sector);
pkt_count_states(pd, states);
seq_printf(m, "\tstate:\t\t\ti:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
states[0], states[1], states[2], states[3], states[4], states[5]);
seq_printf(m, "\twrite congestion marks:\toff=%d on=%d\n",
pd->write_congestion_off,
pd->write_congestion_on);
return 0;
}
static int pkt_seq_open(struct inode *inode, struct file *file)
{
return single_open(file, pkt_seq_show, PDE(inode)->data);
}
static const struct file_operations pkt_proc_fops = {
.open = pkt_seq_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release
};
static int pkt_new_dev(struct pktcdvd_device *pd, dev_t dev)
{
int i;
int ret = 0;
char b[BDEVNAME_SIZE];
struct proc_dir_entry *proc;
struct block_device *bdev;
if (pd->pkt_dev == dev) {
printk(DRIVER_NAME": Recursive setup not allowed\n");
return -EBUSY;
}
for (i = 0; i < MAX_WRITERS; i++) {
struct pktcdvd_device *pd2 = pkt_devs[i];
if (!pd2)
continue;
if (pd2->bdev->bd_dev == dev) {
printk(DRIVER_NAME": %s already setup\n", bdevname(pd2->bdev, b));
return -EBUSY;
}
if (pd2->pkt_dev == dev) {
printk(DRIVER_NAME": Can't chain pktcdvd devices\n");
return -EBUSY;
}
}
bdev = bdget(dev);
if (!bdev)
return -ENOMEM;
ret = blkdev_get(bdev, FMODE_READ, O_RDONLY | O_NONBLOCK);
if (ret)
return ret;
/* This is safe, since we have a reference from open(). */
__module_get(THIS_MODULE);
pd->bdev = bdev;
set_blocksize(bdev, CD_FRAMESIZE);
pkt_init_queue(pd);
atomic_set(&pd->cdrw.pending_bios, 0);
pd->cdrw.thread = kthread_run(kcdrwd, pd, "%s", pd->name);
if (IS_ERR(pd->cdrw.thread)) {
printk(DRIVER_NAME": can't start kernel thread\n");
ret = -ENOMEM;
goto out_mem;
}
proc = create_proc_entry(pd->name, 0, pkt_proc);
if (proc) {
proc->data = pd;
proc->proc_fops = &pkt_proc_fops;
}
DPRINTK(DRIVER_NAME": writer %s mapped to %s\n", pd->name, bdevname(bdev, b));
return 0;
out_mem:
blkdev_put(bdev);
/* This is safe: open() is still holding a reference. */
module_put(THIS_MODULE);
return ret;
}
static int pkt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
{
struct pktcdvd_device *pd = inode->i_bdev->bd_disk->private_data;
VPRINTK("pkt_ioctl: cmd %x, dev %d:%d\n", cmd, imajor(inode), iminor(inode));
switch (cmd) {
/*
* forward selected CDROM ioctls to CD-ROM, for UDF
*/
case CDROMMULTISESSION:
case CDROMREADTOCENTRY:
case CDROM_LAST_WRITTEN:
case CDROM_SEND_PACKET:
case SCSI_IOCTL_SEND_COMMAND:
return blkdev_ioctl(pd->bdev->bd_inode, file, cmd, arg);
case CDROMEJECT:
/*
* The door gets locked when the device is opened, so we
* have to unlock it or else the eject command fails.
*/
if (pd->refcnt == 1)
pkt_lock_door(pd, 0);
return blkdev_ioctl(pd->bdev->bd_inode, file, cmd, arg);
default:
VPRINTK(DRIVER_NAME": Unknown ioctl for %s (%x)\n", pd->name, cmd);
return -ENOTTY;
}
return 0;
}
static int pkt_media_changed(struct gendisk *disk)
{
struct pktcdvd_device *pd = disk->private_data;
struct gendisk *attached_disk;
if (!pd)
return 0;
if (!pd->bdev)
return 0;
attached_disk = pd->bdev->bd_disk;
if (!attached_disk)
return 0;
return attached_disk->fops->media_changed(attached_disk);
}
static struct block_device_operations pktcdvd_ops = {
.owner = THIS_MODULE,
.open = pkt_open,
.release = pkt_close,
.ioctl = pkt_ioctl,
.media_changed = pkt_media_changed,
};
/*
* Set up mapping from pktcdvd device to CD-ROM device.
*/
static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev)
{
int idx;
int ret = -ENOMEM;
struct pktcdvd_device *pd;
struct gendisk *disk;
mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
for (idx = 0; idx < MAX_WRITERS; idx++)
if (!pkt_devs[idx])
break;
if (idx == MAX_WRITERS) {
printk(DRIVER_NAME": max %d writers supported\n", MAX_WRITERS);
ret = -EBUSY;
goto out_mutex;
}
pd = kzalloc(sizeof(struct pktcdvd_device), GFP_KERNEL);
if (!pd)
goto out_mutex;
pd->rb_pool = mempool_create_kmalloc_pool(PKT_RB_POOL_SIZE,
sizeof(struct pkt_rb_node));
if (!pd->rb_pool)
goto out_mem;
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, DRIVER_NAME"%d", idx);
init_waitqueue_head(&pd->wqueue);
pd->bio_queue = RB_ROOT;
pd->write_congestion_on = write_congestion_on;
pd->write_congestion_off = write_congestion_off;
disk = alloc_disk(1);
if (!disk)
goto out_mem;
pd->disk = disk;
disk->major = pktdev_major;
disk->first_minor = idx;
disk->fops = &pktcdvd_ops;
disk->flags = GENHD_FL_REMOVABLE;
strcpy(disk->disk_name, pd->name);
disk->private_data = pd;
disk->queue = blk_alloc_queue(GFP_KERNEL);
if (!disk->queue)
goto out_mem2;
pd->pkt_dev = MKDEV(disk->major, disk->first_minor);
ret = pkt_new_dev(pd, dev);
if (ret)
goto out_new_dev;
add_disk(disk);
pkt_sysfs_dev_new(pd);
pkt_debugfs_dev_new(pd);
pkt_devs[idx] = pd;
if (pkt_dev)
*pkt_dev = pd->pkt_dev;
mutex_unlock(&ctl_mutex);
return 0;
out_new_dev:
blk_cleanup_queue(disk->queue);
out_mem2:
put_disk(disk);
out_mem:
if (pd->rb_pool)
mempool_destroy(pd->rb_pool);
kfree(pd);
out_mutex:
mutex_unlock(&ctl_mutex);
printk(DRIVER_NAME": setup of pktcdvd device failed\n");
return ret;
}
/*
* Tear down mapping from pktcdvd device to CD-ROM device.
*/
static int pkt_remove_dev(dev_t pkt_dev)
{
struct pktcdvd_device *pd;
int idx;
int ret = 0;
mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
for (idx = 0; idx < MAX_WRITERS; idx++) {
pd = pkt_devs[idx];
if (pd && (pd->pkt_dev == pkt_dev))
break;
}
if (idx == MAX_WRITERS) {
DPRINTK(DRIVER_NAME": dev not setup\n");
ret = -ENXIO;
goto out;
}
if (pd->refcnt > 0) {
ret = -EBUSY;
goto out;
}
if (!IS_ERR(pd->cdrw.thread))
kthread_stop(pd->cdrw.thread);
pkt_devs[idx] = NULL;
pkt_debugfs_dev_remove(pd);
pkt_sysfs_dev_remove(pd);
blkdev_put(pd->bdev);
remove_proc_entry(pd->name, pkt_proc);
DPRINTK(DRIVER_NAME": writer %s unmapped\n", pd->name);
del_gendisk(pd->disk);
blk_cleanup_queue(pd->disk->queue);
put_disk(pd->disk);
mempool_destroy(pd->rb_pool);
kfree(pd);
/* This is safe: open() is still holding a reference. */
module_put(THIS_MODULE);
out:
mutex_unlock(&ctl_mutex);
return ret;
}
static void pkt_get_status(struct pkt_ctrl_command *ctrl_cmd)
{
struct pktcdvd_device *pd;
mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
pd = pkt_find_dev_from_minor(ctrl_cmd->dev_index);
if (pd) {
ctrl_cmd->dev = new_encode_dev(pd->bdev->bd_dev);
ctrl_cmd->pkt_dev = new_encode_dev(pd->pkt_dev);
} else {
ctrl_cmd->dev = 0;
ctrl_cmd->pkt_dev = 0;
}
ctrl_cmd->num_devices = MAX_WRITERS;
mutex_unlock(&ctl_mutex);
}
static int pkt_ctl_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
{
void __user *argp = (void __user *)arg;
struct pkt_ctrl_command ctrl_cmd;
int ret = 0;
dev_t pkt_dev = 0;
if (cmd != PACKET_CTRL_CMD)
return -ENOTTY;
if (copy_from_user(&ctrl_cmd, argp, sizeof(struct pkt_ctrl_command)))
return -EFAULT;
switch (ctrl_cmd.command) {
case PKT_CTRL_CMD_SETUP:
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
ret = pkt_setup_dev(new_decode_dev(ctrl_cmd.dev), &pkt_dev);
ctrl_cmd.pkt_dev = new_encode_dev(pkt_dev);
break;
case PKT_CTRL_CMD_TEARDOWN:
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
ret = pkt_remove_dev(new_decode_dev(ctrl_cmd.pkt_dev));
break;
case PKT_CTRL_CMD_STATUS:
pkt_get_status(&ctrl_cmd);
break;
default:
return -ENOTTY;
}
if (copy_to_user(argp, &ctrl_cmd, sizeof(struct pkt_ctrl_command)))
return -EFAULT;
return ret;
}
static const struct file_operations pkt_ctl_fops = {
.ioctl = pkt_ctl_ioctl,
.owner = THIS_MODULE,
};
static struct miscdevice pkt_misc = {
.minor = MISC_DYNAMIC_MINOR,
.name = DRIVER_NAME,
.fops = &pkt_ctl_fops
};
static int __init pkt_init(void)
{
int ret;
mutex_init(&ctl_mutex);
psd_pool = mempool_create_kmalloc_pool(PSD_POOL_SIZE,
sizeof(struct packet_stacked_data));
if (!psd_pool)
return -ENOMEM;
ret = register_blkdev(pktdev_major, DRIVER_NAME);
if (ret < 0) {
printk(DRIVER_NAME": Unable to register block device\n");
goto out2;
}
if (!pktdev_major)
pktdev_major = ret;
ret = pkt_sysfs_init();
if (ret)
goto out;
pkt_debugfs_init();
ret = misc_register(&pkt_misc);
if (ret) {
printk(DRIVER_NAME": Unable to register misc device\n");
goto out_misc;
}
pkt_proc = proc_mkdir(DRIVER_NAME, proc_root_driver);
return 0;
out_misc:
pkt_debugfs_cleanup();
pkt_sysfs_cleanup();
out:
unregister_blkdev(pktdev_major, DRIVER_NAME);
out2:
mempool_destroy(psd_pool);
return ret;
}
static void __exit pkt_exit(void)
{
remove_proc_entry(DRIVER_NAME, proc_root_driver);
misc_deregister(&pkt_misc);
pkt_debugfs_cleanup();
pkt_sysfs_cleanup();
unregister_blkdev(pktdev_major, DRIVER_NAME);
mempool_destroy(psd_pool);
}
MODULE_DESCRIPTION("Packet writing layer for CD/DVD drives");
MODULE_AUTHOR("Jens Axboe <axboe@suse.de>");
MODULE_LICENSE("GPL");
module_init(pkt_init);
module_exit(pkt_exit);
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