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android-kvm / linux / 8939a3af5c08daca7914c53d9f99c222569b6509 / . / drivers / block / pktcdvd.c
blob: 0b944ac96d6b26e4b3d07d732db977054d7f2ba6 [file] [log] [blame]
/*
* 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.
*
*************************************************************************/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/pktcdvd.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/compat.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 <linux/slab.h>
#include <linux/backing-dev.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_ioctl.h>
#include <scsi/scsi.h>
#include <linux/debugfs.h>
#include <linux/device.h>
#include <linux/nospec.h>
#include <linux/uaccess.h>
#define DRIVER_NAME "pktcdvd"
#define pkt_err(pd, fmt, ...) \
pr_err("%s: " fmt, pd->name, ##__VA_ARGS__)
#define pkt_notice(pd, fmt, ...) \
pr_notice("%s: " fmt, pd->name, ##__VA_ARGS__)
#define pkt_info(pd, fmt, ...) \
pr_info("%s: " fmt, pd->name, ##__VA_ARGS__)
#define pkt_dbg(level, pd, fmt, ...) \
do { \
if (level == 2 && PACKET_DEBUG >= 2) \
pr_notice("%s: %s():" fmt, \
pd->name, __func__, ##__VA_ARGS__); \
else if (level == 1 && PACKET_DEBUG >= 1) \
pr_notice("%s: " fmt, pd->name, ##__VA_ARGS__); \
} while (0)
#define MAX_SPEED 0xffff
static DEFINE_MUTEX(pktcdvd_mutex);
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 bio_set pkt_bio_set;
static struct class *class_pktcdvd = NULL; /* /sys/class/pktcdvd */
static struct dentry *pkt_debugfs_root = NULL; /* /sys/kernel/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);
static sector_t get_zone(sector_t sector, struct pktcdvd_device *pd)
{
return (sector + pd->offset) & ~(sector_t)(pd->settings.size - 1);
}
/*
* 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 const 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, MKDEV(0, 0), NULL,
"%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_unregister(pd->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 device_map_show(struct class *c, struct class_attribute *attr,
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 CLASS_ATTR_RO(device_map);
static ssize_t add_store(struct class *c, struct class_attribute *attr,
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 CLASS_ATTR_WO(add);
static ssize_t remove_store(struct class *c, struct class_attribute *attr,
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 CLASS_ATTR_WO(remove);
static struct attribute *class_pktcdvd_attrs[] = {
&class_attr_add.attr,
&class_attr_remove.attr,
&class_attr_device_map.attr,
NULL,
};
ATTRIBUTE_GROUPS(class_pktcdvd);
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_groups = class_pktcdvd_groups;
ret = class_register(class_pktcdvd);
if (ret) {
kfree(class_pktcdvd);
class_pktcdvd = NULL;
pr_err("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
/sys/kernel/debug/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_d_root = debugfs_create_dir(pd->name, pkt_debugfs_root);
if (!pd->dfs_d_root)
return;
pd->dfs_f_info = debugfs_create_file("info", 0444,
pd->dfs_d_root, pd, &debug_fops);
}
static void pkt_debugfs_dev_remove(struct pktcdvd_device *pd)
{
if (!pkt_debugfs_root)
return;
debugfs_remove(pd->dfs_f_info);
debugfs_remove(pd->dfs_d_root);
pd->dfs_f_info = NULL;
pd->dfs_d_root = NULL;
}
static void pkt_debugfs_init(void)
{
pkt_debugfs_root = debugfs_create_dir(DRIVER_NAME, NULL);
}
static void pkt_debugfs_cleanup(void)
{
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)) {
pkt_dbg(2, pd, "queue empty\n");
atomic_set(&pd->iosched.attention, 1);
wake_up(&pd->wqueue);
}
}
/*
* 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 = bio_kmalloc(GFP_KERNEL, 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);
bio_list_init(&pkt->orig_bios);
for (i = 0; i < frames; i++) {
struct bio *bio = bio_kmalloc(GFP_KERNEL, 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_iter.bi_sector)
next = n->rb_left;
else
next = n->rb_right;
if (!next)
break;
n = next;
}
if (s > tmp->bio->bi_iter.bi_sector) {
tmp = pkt_rbtree_next(tmp);
if (!tmp)
return NULL;
}
BUG_ON(s > tmp->bio->bi_iter.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_iter.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_iter.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++;
}
/*
* 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) ?
REQ_OP_SCSI_OUT : REQ_OP_SCSI_IN, 0);
if (IS_ERR(rq))
return PTR_ERR(rq);
if (cgc->buflen) {
ret = blk_rq_map_kern(q, rq, cgc->buffer, cgc->buflen,
GFP_NOIO);
if (ret)
goto out;
}
scsi_req(rq)->cmd_len = COMMAND_SIZE(cgc->cmd[0]);
memcpy(scsi_req(rq)->cmd, cgc->cmd, CDROM_PACKET_SIZE);
rq->timeout = 60*HZ;
if (cgc->quiet)
rq->rq_flags |= RQF_QUIET;
blk_execute_rq(rq->q, pd->bdev->bd_disk, rq, 0);
if (scsi_req(rq)->result)
ret = -EIO;
out:
blk_put_request(rq);
return ret;
}
static const char *sense_key_string(__u8 index)
{
static const char * const info[] = {
"No sense", "Recovered error", "Not ready",
"Medium error", "Hardware error", "Illegal request",
"Unit attention", "Data protect", "Blank check",
};
return index < ARRAY_SIZE(info) ? info[index] : "INVALID";
}
/*
* A generic sense dump / resolve mechanism should be implemented across
* all ATAPI + SCSI devices.
*/
static void pkt_dump_sense(struct pktcdvd_device *pd,
struct packet_command *cgc)
{
struct scsi_sense_hdr *sshdr = cgc->sshdr;
if (sshdr)
pkt_err(pd, "%*ph - sense %02x.%02x.%02x (%s)\n",
CDROM_PACKET_SIZE, cgc->cmd,
sshdr->sense_key, sshdr->asc, sshdr->ascq,
sense_key_string(sshdr->sense_key));
else
pkt_err(pd, "%*ph - no sense\n", CDROM_PACKET_SIZE, cgc->cmd);
}
/*
* 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 scsi_sense_hdr sshdr;
int ret;
init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
cgc.sshdr = &sshdr;
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;
ret = pkt_generic_packet(pd, &cgc);
if (ret)
pkt_dump_sense(pd, &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)
bio_list_add(&pd->iosched.read_queue, bio);
else
bio_list_add(&pd->iosched.write_queue, bio);
spin_unlock(&pd->iosched.lock);
atomic_set(&pd->iosched.attention, 1);
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 = !bio_list_empty(&pd->iosched.read_queue);
writes_queued = !bio_list_empty(&pd->iosched.write_queue);
spin_unlock(&pd->iosched.lock);
if (!reads_queued && !writes_queued)
break;
if (pd->iosched.writing) {
int need_write_seek = 1;
spin_lock(&pd->iosched.lock);
bio = bio_list_peek(&pd->iosched.write_queue);
spin_unlock(&pd->iosched.lock);
if (bio && (bio->bi_iter.bi_sector ==
pd->iosched.last_write))
need_write_seek = 0;
if (need_write_seek && reads_queued) {
if (atomic_read(&pd->cdrw.pending_bios) > 0) {
pkt_dbg(2, pd, "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) {
pkt_dbg(2, pd, "read, waiting\n");
break;
}
pd->iosched.writing = 1;
}
}
spin_lock(&pd->iosched.lock);
if (pd->iosched.writing)
bio = bio_list_pop(&pd->iosched.write_queue);
else
bio = bio_list_pop(&pd->iosched.read_queue);
spin_unlock(&pd->iosched.lock);
if (!bio)
continue;
if (bio_data_dir(bio) == READ)
pd->iosched.successive_reads +=
bio->bi_iter.bi_size >> 10;
else {
pd->iosched.successive_reads = 0;
pd->iosched.last_write = bio_end_sector(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
<= queue_max_segments(q)) {
/*
* 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
<= queue_max_segments(q)) {
/*
* 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 {
pkt_err(pd, "cdrom max_phys_segments too small\n");
return -EIO;
}
}
static void pkt_end_io_read(struct bio *bio)
{
struct packet_data *pkt = bio->bi_private;
struct pktcdvd_device *pd = pkt->pd;
BUG_ON(!pd);
pkt_dbg(2, pd, "bio=%p sec0=%llx sec=%llx err=%d\n",
bio, (unsigned long long)pkt->sector,
(unsigned long long)bio->bi_iter.bi_sector, bio->bi_status);
if (bio->bi_status)
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)
{
struct packet_data *pkt = bio->bi_private;
struct pktcdvd_device *pd = pkt->pd;
BUG_ON(!pd);
pkt_dbg(2, pd, "id=%d, err=%d\n", pkt->id, bio->bi_status);
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(bio_list_empty(&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);
bio_list_for_each(bio, &pkt->orig_bios) {
int first_frame = (bio->bi_iter.bi_sector - pkt->sector) /
(CD_FRAMESIZE >> 9);
int num_frames = bio->bi_iter.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) {
pkt_dbg(2, pd, "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++) {
int p, offset;
if (written[f])
continue;
bio = pkt->r_bios[f];
bio_reset(bio);
bio->bi_iter.bi_sector = pkt->sector + f * (CD_FRAMESIZE >> 9);
bio_set_dev(bio, pd->bdev);
bio->bi_end_io = pkt_end_io_read;
bio->bi_private = pkt;
p = (f * CD_FRAMESIZE) / PAGE_SIZE;
offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
pkt_dbg(2, pd, "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_set_op_attrs(bio, REQ_OP_READ, 0);
pkt_queue_bio(pd, bio);
frames_read++;
}
out_account:
pkt_dbg(2, pd, "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->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;
bio_reset(pkt->bio);
bio_set_dev(pkt->bio, pd->bdev);
bio_set_op_attrs(pkt->bio, REQ_OP_WRITE, 0);
pkt->bio->bi_iter.bi_sector = new_sector;
pkt->bio->bi_iter.bi_size = pkt->frames * CD_FRAMESIZE;
pkt->bio->bi_vcnt = pkt->frames;
pkt->bio->bi_end_io = pkt_end_io_packet_write;
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;
pkt_dbg(2, pd, "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;
atomic_set(&pd->scan_queue, 0);
if (list_empty(&pd->cdrw.pkt_free_list)) {
pkt_dbg(2, pd, "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 = get_zone(bio->bi_iter.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) {
pkt_dbg(2, pd, "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);
pkt_dbg(2, pd, "looking for zone %llx\n", (unsigned long long)zone);
while ((node = pkt_rbtree_find(pd, zone)) != NULL) {
bio = node->bio;
pkt_dbg(2, pd, "found zone=%llx\n", (unsigned long long)
get_zone(bio->bi_iter.bi_sector, pd));
if (get_zone(bio->bi_iter.bi_sector, pd) != zone)
break;
pkt_rbtree_erase(pd, node);
spin_lock(&pkt->lock);
bio_list_add(&pkt->orig_bios, bio);
pkt->write_size += bio->bi_iter.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,
BLK_RW_ASYNC);
}
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)
{
int f;
bio_reset(pkt->w_bio);
pkt->w_bio->bi_iter.bi_sector = pkt->sector;
bio_set_dev(pkt->w_bio, pd->bdev);
pkt->w_bio->bi_end_io = pkt_end_io_packet_write;
pkt->w_bio->bi_private = pkt;
/* XXX: locking? */
for (f = 0; f < pkt->frames; f++) {
struct page *page = pkt->pages[(f * CD_FRAMESIZE) / PAGE_SIZE];
unsigned offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
if (!bio_add_page(pkt->w_bio, page, CD_FRAMESIZE, offset))
BUG();
}
pkt_dbg(2, pd, "vcnt=%d\n", pkt->w_bio->bi_vcnt);
/*
* Fill-in bvec with data from orig_bios.
*/
spin_lock(&pkt->lock);
bio_list_copy_data(pkt->w_bio, pkt->orig_bios.head);
pkt_set_state(pkt, PACKET_WRITE_WAIT_STATE);
spin_unlock(&pkt->lock);
pkt_dbg(2, pd, "Writing %d frames for zone %llx\n",
pkt->write_size, (unsigned long long)pkt->sector);
if (test_bit(PACKET_MERGE_SEGS, &pd->flags) || (pkt->write_size < pkt->frames))
pkt->cache_valid = 1;
else
pkt->cache_valid = 0;
/* Start the write request */
atomic_set(&pkt->io_wait, 1);
bio_set_op_attrs(pkt->w_bio, REQ_OP_WRITE, 0);
pkt_queue_bio(pd, pkt->w_bio);
}
static void pkt_finish_packet(struct packet_data *pkt, blk_status_t status)
{
struct bio *bio;
if (status)
pkt->cache_valid = 0;
/* Finish all bios corresponding to this packet */
while ((bio = bio_list_pop(&pkt->orig_bios))) {
bio->bi_status = status;
bio_endio(bio);
}
}
static void pkt_run_state_machine(struct pktcdvd_device *pd, struct packet_data *pkt)
{
pkt_dbg(2, pd, "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 (!pkt->w_bio->bi_status) {
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 {
pkt_dbg(2, pd, "No recovery possible\n");
pkt_set_state(pkt, PACKET_FINISHED_STATE);
}
break;
case PACKET_FINISHED_STATE:
pkt_finish_packet(pkt, pkt->w_bio->bi_status);
return;
default:
BUG();
break;
}
}
}
static void pkt_handle_packets(struct pktcdvd_device *pd)
{
struct packet_data *pkt, *next;
/*
* 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, MIN_NICE);
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);
pkt_dbg(2, pd, "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;
}
pkt_dbg(2, pd, "sleeping\n");
residue = schedule_timeout(min_sleep_time);
pkt_dbg(2, pd, "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)
{
pkt_info(pd, "%s packets, %u blocks, Mode-%c disc\n",
pd->settings.fp ? "Fixed" : "Variable",
pd->settings.size >> 2,
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;
ret = pkt_generic_packet(pd, &cgc);
if (ret)
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;
ret = pkt_generic_packet(pd, &cgc);
if (ret)
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;
ret = pkt_get_disc_info(pd, &di);
if (ret)
return ret;
last_track = (di.last_track_msb << 8) | di.last_track_lsb;
ret = pkt_get_track_info(pd, last_track, 1, &ti);
if (ret)
return ret;
/* if this track is blank, try the previous. */
if (ti.blank) {
last_track--;
ret = pkt_get_track_info(pd, last_track, 1, &ti);
if (ret)
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 scsi_sense_hdr sshdr;
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.sshdr = &sshdr;
ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0);
if (ret) {
pkt_dump_sense(pd, &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.sshdr = &sshdr;
ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0);
if (ret) {
pkt_dump_sense(pd, &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
*/
pkt_err(pd, "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;
ret = pkt_mode_select(pd, &cgc);
if (ret) {
pkt_dump_sense(pd, &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;
pkt_err(pd, "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:
pkt_dbg(2, pd, "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) {
pkt_notice(pd, "unknown disc - no track?\n");
return 0;
}
if (di->disc_type != 0x20 && di->disc_type != 0) {
pkt_err(pd, "wrong disc type (%x)\n", di->disc_type);
return 0;
}
if (di->erasable == 0) {
pkt_notice(pd, "disc not erasable\n");
return 0;
}
if (di->border_status == PACKET_SESSION_RESERVED) {
pkt_err(pd, "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));
ret = pkt_get_disc_info(pd, &di);
if (ret) {
pkt_err(pd, "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; */
ret = pkt_get_track_info(pd, track, 1, &ti);
if (ret) {
pkt_err(pd, "failed get_track\n");
return ret;
}
if (!pkt_writable_track(pd, &ti)) {
pkt_err(pd, "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) {
pkt_notice(pd, "detected zero packet size!\n");
return -ENXIO;
}
if (pd->settings.size > PACKET_MAX_SECTORS) {
pkt_err(pd, "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:
pkt_err(pd, "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 scsi_sense_hdr sshdr;
unsigned char buf[64];
int ret;
init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
cgc.sshdr = &sshdr;
cgc.buflen = pd->mode_offset + 12;
/*
* caching mode page might not be there, so quiet this command
*/
cgc.quiet = 1;
ret = pkt_mode_sense(pd, &cgc, GPMODE_WCACHING_PAGE, 0);
if (ret)
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) {
pkt_err(pd, "write caching control failed\n");
pkt_dump_sense(pd, &cgc);
} else if (!ret && set)
pkt_notice(pd, "enabled write caching\n");
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 scsi_sense_hdr sshdr;
unsigned char buf[256+18];
unsigned char *cap_buf;
int ret, offset;
cap_buf = &buf[sizeof(struct mode_page_header) + pd->mode_offset];
init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_UNKNOWN);
cgc.sshdr = &sshdr;
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(pd, &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 scsi_sense_hdr sshdr;
unsigned char buf[64];
unsigned int size, st, sp;
int ret;
init_cdrom_command(&cgc, buf, 2, CGC_DATA_READ);
cgc.sshdr = &sshdr;
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(pd, &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.sshdr = &sshdr;
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(pd, &cgc);
return ret;
}
if (!(buf[6] & 0x40)) {
pkt_notice(pd, "disc type is not CD-RW\n");
return 1;
}
if (!(buf[6] & 0x4)) {
pkt_notice(pd, "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:
pkt_notice(pd, "unknown disc sub-type %d\n", st);
return 1;
}
if (*speed) {
pkt_info(pd, "maximum media speed: %d\n", *speed);
return 0;
} else {
pkt_notice(pd, "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 scsi_sense_hdr sshdr;
int ret;
pkt_dbg(2, pd, "Performing OPC\n");
init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
cgc.sshdr = &sshdr;
cgc.timeout = 60*HZ;
cgc.cmd[0] = GPCMD_SEND_OPC;
cgc.cmd[1] = 1;
ret = pkt_generic_packet(pd, &cgc);
if (ret)
pkt_dump_sense(pd, &cgc);
return ret;
}
static int pkt_open_write(struct pktcdvd_device *pd)
{
int ret;
unsigned int write_speed, media_write_speed, read_speed;
ret = pkt_probe_settings(pd);
if (ret) {
pkt_dbg(2, pd, "failed probe\n");
return ret;
}
ret = pkt_set_write_settings(pd);
if (ret) {
pkt_dbg(1, pd, "failed saving write settings\n");
return -EIO;
}
pkt_write_caching(pd, USE_WCACHING);
ret = pkt_get_max_speed(pd, &write_speed);
if (ret)
write_speed = 16 * 177;
switch (pd->mmc3_profile) {
case 0x13: /* DVD-RW */
case 0x1a: /* DVD+RW */
case 0x12: /* DVD-RAM */
pkt_dbg(1, pd, "write speed %ukB/s\n", write_speed);
break;
default:
ret = pkt_media_speed(pd, &media_write_speed);
if (ret)
media_write_speed = 16;
write_speed = min(write_speed, media_write_speed * 177);
pkt_dbg(1, pd, "write speed %ux\n", write_speed / 176);
break;
}
read_speed = write_speed;
ret = pkt_set_speed(pd, write_speed, read_speed);
if (ret) {
pkt_dbg(1, pd, "couldn't set write speed\n");
return -EIO;
}
pd->write_speed = write_speed;
pd->read_speed = read_speed;
ret = pkt_perform_opc(pd);
if (ret) {
pkt_dbg(1, pd, "Optimum Power Calibration failed\n");
}
return 0;
}
/*
* called at open time.
*/
static int pkt_open_dev(struct pktcdvd_device *pd, fmode_t 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);
ret = blkdev_get(pd->bdev, FMODE_READ | FMODE_EXCL, pd);
if (ret)
goto out;
ret = pkt_get_last_written(pd, &lba);
if (ret) {
pkt_err(pd, "pkt_get_last_written failed\n");
goto out_putdev;
}
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) {
ret = pkt_open_write(pd);
if (ret)
goto out_putdev;
/*
* Some CDRW drives can not handle writes larger than one packet,
* even if the size is a multiple of the packet size.
*/
blk_queue_max_hw_sectors(q, pd->settings.size);
set_bit(PACKET_WRITABLE, &pd->flags);
} else {
pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
clear_bit(PACKET_WRITABLE, &pd->flags);
}
ret = pkt_set_segment_merging(pd, q);
if (ret)
goto out_putdev;
if (write) {
if (!pkt_grow_pktlist(pd, CONFIG_CDROM_PKTCDVD_BUFFERS)) {
pkt_err(pd, "not enough memory for buffers\n");
ret = -ENOMEM;
goto out_putdev;
}
pkt_info(pd, "%lukB available on disc\n", lba << 1);
}
return 0;
out_putdev:
blkdev_put(pd->bdev, FMODE_READ | FMODE_EXCL);
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))
pkt_dbg(1, pd, "not flushing cache\n");
pkt_lock_door(pd, 0);
pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
blkdev_put(pd->bdev, FMODE_READ | FMODE_EXCL);
pkt_shrink_pktlist(pd);
}
static struct pktcdvd_device *pkt_find_dev_from_minor(unsigned int dev_minor)
{
if (dev_minor >= MAX_WRITERS)
return NULL;
dev_minor = array_index_nospec(dev_minor, MAX_WRITERS);
return pkt_devs[dev_minor];
}
static int pkt_open(struct block_device *bdev, fmode_t mode)
{
struct pktcdvd_device *pd = NULL;
int ret;
mutex_lock(&pktcdvd_mutex);
mutex_lock(&ctl_mutex);
pd = pkt_find_dev_from_minor(MINOR(bdev->bd_dev));
if (!pd) {
ret = -ENODEV;
goto out;
}
BUG_ON(pd->refcnt < 0);
pd->refcnt++;
if (pd->refcnt > 1) {
if ((mode & FMODE_WRITE) &&
!test_bit(PACKET_WRITABLE, &pd->flags)) {
ret = -EBUSY;
goto out_dec;
}
} else {
ret = pkt_open_dev(pd, 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(bdev, CD_FRAMESIZE);
}
mutex_unlock(&ctl_mutex);
mutex_unlock(&pktcdvd_mutex);
return 0;
out_dec:
pd->refcnt--;
out:
mutex_unlock(&ctl_mutex);
mutex_unlock(&pktcdvd_mutex);
return ret;
}
static void pkt_close(struct gendisk *disk, fmode_t mode)
{
struct pktcdvd_device *pd = disk->private_data;
mutex_lock(&pktcdvd_mutex);
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);
mutex_unlock(&pktcdvd_mutex);
}
static void pkt_end_io_read_cloned(struct bio *bio)
{
struct packet_stacked_data *psd = bio->bi_private;
struct pktcdvd_device *pd = psd->pd;
psd->bio->bi_status = bio->bi_status;
bio_put(bio);
bio_endio(psd->bio);
mempool_free(psd, &psd_pool);
pkt_bio_finished(pd);
}
static void pkt_make_request_read(struct pktcdvd_device *pd, struct bio *bio)
{
struct bio *cloned_bio = bio_clone_fast(bio, GFP_NOIO, &pkt_bio_set);
struct packet_stacked_data *psd = mempool_alloc(&psd_pool, GFP_NOIO);
psd->pd = pd;
psd->bio = bio;
bio_set_dev(cloned_bio, pd->bdev);
cloned_bio->bi_private = psd;
cloned_bio->bi_end_io = pkt_end_io_read_cloned;
pd->stats.secs_r += bio_sectors(bio);
pkt_queue_bio(pd, cloned_bio);
}
static void pkt_make_request_write(struct request_queue *q, struct bio *bio)
{
struct pktcdvd_device *pd = q->queuedata;
sector_t zone;
struct packet_data *pkt;
int was_empty, blocked_bio;
struct pkt_rb_node *node;
zone = get_zone(bio->bi_iter.bi_sector, pd);
/*
* 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)) {
bio_list_add(&pkt->orig_bios, bio);
pkt->write_size +=
bio->bi_iter.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;
} 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, BLK_RW_ASYNC);
do {
spin_unlock(&pd->lock);
congestion_wait(BLK_RW_ASYNC, 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);
}
}
static blk_qc_t pkt_make_request(struct request_queue *q, struct bio *bio)
{
struct pktcdvd_device *pd;
char b[BDEVNAME_SIZE];
struct bio *split;
blk_queue_split(q, &bio);
pd = q->queuedata;
if (!pd) {
pr_err("%s incorrect request queue\n", bio_devname(bio, b));
goto end_io;
}
pkt_dbg(2, pd, "start = %6llx stop = %6llx\n",
(unsigned long long)bio->bi_iter.bi_sector,
(unsigned long long)bio_end_sector(bio));
/*
* Clone READ bios so we can have our own bi_end_io callback.
*/
if (bio_data_dir(bio) == READ) {
pkt_make_request_read(pd, bio);
return BLK_QC_T_NONE;
}
if (!test_bit(PACKET_WRITABLE, &pd->flags)) {
pkt_notice(pd, "WRITE for ro device (%llu)\n",
(unsigned long long)bio->bi_iter.bi_sector);
goto end_io;
}
if (!bio->bi_iter.bi_size || (bio->bi_iter.bi_size % CD_FRAMESIZE)) {
pkt_err(pd, "wrong bio size\n");
goto end_io;
}
do {
sector_t zone = get_zone(bio->bi_iter.bi_sector, pd);
sector_t last_zone = get_zone(bio_end_sector(bio) - 1, pd);
if (last_zone != zone) {
BUG_ON(last_zone != zone + pd->settings.size);
split = bio_split(bio, last_zone -
bio->bi_iter.bi_sector,
GFP_NOIO, &pkt_bio_set);
bio_chain(split, bio);
} else {
split = bio;
}
pkt_make_request_write(q, split);
} while (split != bio);
return BLK_QC_T_NONE;
end_io:
bio_io_error(bio);
return BLK_QC_T_NONE;
}
static void pkt_init_queue(struct pktcdvd_device *pd)
{
struct request_queue *q = pd->disk->queue;
blk_queue_logical_block_size(q, CD_FRAMESIZE);
blk_queue_max_hw_sectors(q, PACKET_MAX_SECTORS);
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_new_dev(struct pktcdvd_device *pd, dev_t dev)
{
int i;
int ret = 0;
char b[BDEVNAME_SIZE];
struct block_device *bdev;
if (pd->pkt_dev == dev) {
pkt_err(pd, "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) {
pkt_err(pd, "%s already setup\n",
bdevname(pd2->bdev, b));
return -EBUSY;
}
if (pd2->pkt_dev == dev) {
pkt_err(pd, "can't chain pktcdvd devices\n");
return -EBUSY;
}
}
bdev = bdget(dev);
if (!bdev)
return -ENOMEM;
ret = blkdev_get(bdev, FMODE_READ | FMODE_NDELAY, NULL);
if (ret)
return ret;
if (!blk_queue_scsi_passthrough(bdev_get_queue(bdev))) {
blkdev_put(bdev, FMODE_READ | FMODE_NDELAY);
return -EINVAL;
}
/* 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)) {
pkt_err(pd, "can't start kernel thread\n");
ret = -ENOMEM;
goto out_mem;
}
proc_create_single_data(pd->name, 0, pkt_proc, pkt_seq_show, pd);
pkt_dbg(1, pd, "writer mapped to %s\n", bdevname(bdev, b));
return 0;
out_mem:
blkdev_put(bdev, FMODE_READ | FMODE_NDELAY);
/* This is safe: open() is still holding a reference. */
module_put(THIS_MODULE);
return ret;
}
static int pkt_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, unsigned long arg)
{
struct pktcdvd_device *pd = bdev->bd_disk->private_data;
int ret;
pkt_dbg(2, pd, "cmd %x, dev %d:%d\n",
cmd, MAJOR(bdev->bd_dev), MINOR(bdev->bd_dev));
mutex_lock(&pktcdvd_mutex);
switch (cmd) {
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);
/* fall through */
/*
* 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:
ret = __blkdev_driver_ioctl(pd->bdev, mode, cmd, arg);
break;
default:
pkt_dbg(2, pd, "Unknown ioctl (%x)\n", cmd);
ret = -ENOTTY;
}
mutex_unlock(&pktcdvd_mutex);
return ret;
}
static unsigned int pkt_check_events(struct gendisk *disk,
unsigned int clearing)
{
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 || !attached_disk->fops->check_events)
return 0;
return attached_disk->fops->check_events(attached_disk, clearing);
}
static char *pkt_devnode(struct gendisk *disk, umode_t *mode)
{
return kasprintf(GFP_KERNEL, "pktcdvd/%s", disk->disk_name);
}
static const struct block_device_operations pktcdvd_ops = {
.owner = THIS_MODULE,
.open = pkt_open,
.release = pkt_close,
.ioctl = pkt_ioctl,
.compat_ioctl = blkdev_compat_ptr_ioctl,
.check_events = pkt_check_events,
.devnode = pkt_devnode,
};
/*
* 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) {
pr_err("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;
ret = mempool_init_kmalloc_pool(&pd->rb_pool, PKT_RB_POOL_SIZE,
sizeof(struct pkt_rb_node));
if (ret)
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);
bio_list_init(&pd->iosched.read_queue);
bio_list_init(&pd->iosched.write_queue);
sprintf(pd->name, DRIVER_NAME"%d", idx);
init_waitqueue_head(&pd->wqueue);
pd->bio_queue = RB_ROOT;
pd->write_congestion_on = write_congestion_on;
pd->write_congestion_off = write_congestion_off;
ret = -ENOMEM;
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(pkt_make_request, NUMA_NO_NODE);
if (!disk->queue)
goto out_mem2;
pd->pkt_dev = MKDEV(pktdev_major, idx);
ret = pkt_new_dev(pd, dev);
if (ret)
goto out_mem2;
/* inherit events of the host device */
disk->events = pd->bdev->bd_disk->events;
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_mem2:
put_disk(disk);
out_mem:
mempool_exit(&pd->rb_pool);
kfree(pd);
out_mutex:
mutex_unlock(&ctl_mutex);
pr_err("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) {
pr_debug("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, FMODE_READ | FMODE_NDELAY);
remove_proc_entry(pd->name, pkt_proc);
pkt_dbg(1, pd, "writer unmapped\n");
del_gendisk(pd->disk);
blk_cleanup_queue(pd->disk->queue);
put_disk(pd->disk);
mempool_exit(&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 long pkt_ctl_ioctl(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;
}
#ifdef CONFIG_COMPAT
static long pkt_ctl_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
return pkt_ctl_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
}
#endif
static const struct file_operations pkt_ctl_fops = {
.open = nonseekable_open,
.unlocked_ioctl = pkt_ctl_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = pkt_ctl_compat_ioctl,
#endif
.owner = THIS_MODULE,
.llseek = no_llseek,
};
static struct miscdevice pkt_misc = {
.minor = MISC_DYNAMIC_MINOR,
.name = DRIVER_NAME,
.nodename = "pktcdvd/control",
.fops = &pkt_ctl_fops
};
static int __init pkt_init(void)
{
int ret;
mutex_init(&ctl_mutex);
ret = mempool_init_kmalloc_pool(&psd_pool, PSD_POOL_SIZE,
sizeof(struct packet_stacked_data));
if (ret)
return ret;
ret = bioset_init(&pkt_bio_set, BIO_POOL_SIZE, 0, 0);
if (ret) {
mempool_exit(&psd_pool);
return ret;
}
ret = register_blkdev(pktdev_major, DRIVER_NAME);
if (ret < 0) {
pr_err("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) {
pr_err("unable to register misc device\n");
goto out_misc;
}
pkt_proc = proc_mkdir("driver/"DRIVER_NAME, NULL);
return 0;
out_misc:
pkt_debugfs_cleanup();
pkt_sysfs_cleanup();
out:
unregister_blkdev(pktdev_major, DRIVER_NAME);
out2:
mempool_exit(&psd_pool);
bioset_exit(&pkt_bio_set);
return ret;
}
static void __exit pkt_exit(void)
{
remove_proc_entry("driver/"DRIVER_NAME, NULL);
misc_deregister(&pkt_misc);
pkt_debugfs_cleanup();
pkt_sysfs_cleanup();
unregister_blkdev(pktdev_major, DRIVER_NAME);
mempool_exit(&psd_pool);
bioset_exit(&pkt_bio_set);
}
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);