linux/drivers/block/pktcdvd.c

3118 lines
76 KiB
C
Raw Normal View History

/*
* 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/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 cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
#include <linux/slab.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 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 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);
/*
* 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 class_pktcdvd_show_map(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 ssize_t class_pktcdvd_store_add(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 ssize_t class_pktcdvd_store_remove(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 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
/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_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);
bio_list_init(&pkt->orig_bios);
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++;
}
/*
* 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);
rq->timeout = 60*HZ;
rq->cmd_type = REQ_TYPE_BLOCK_PC;
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)
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_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 = 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_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
<= 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 {
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(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_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 != REQ_WRITE);
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);
bio_list_add(&pkt->orig_bios, bio);
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,
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)
{
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);
bio_list_for_each(bio, &pkt->orig_bios) {
int segment = bio->bi_idx;
int src_offs = 0;
int first_frame = (bio->bi_sector - pkt->sector) / (CD_FRAMESIZE >> 9);
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;
if (!uptodate)
pkt->cache_valid = 0;
/* Finish all bios corresponding to this packet */
while ((bio = bio_list_pop(&pkt->orig_bios)))
bio_endio(bio, uptodate ? 0 : -EIO);
}
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;
}
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;
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;
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, 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);
block: make blkdev_get/put() handle exclusive access Over time, block layer has accumulated a set of APIs dealing with bdev open, close, claim and release. * blkdev_get/put() are the primary open and close functions. * bd_claim/release() deal with exclusive open. * open/close_bdev_exclusive() are combination of open and claim and the other way around, respectively. * bd_link/unlink_disk_holder() to create and remove holder/slave symlinks. * open_by_devnum() wraps bdget() + blkdev_get(). The interface is a bit confusing and the decoupling of open and claim makes it impossible to properly guarantee exclusive access as in-kernel open + claim sequence can disturb the existing exclusive open even before the block layer knows the current open if for another exclusive access. Reorganize the interface such that, * blkdev_get() is extended to include exclusive access management. @holder argument is added and, if is @FMODE_EXCL specified, it will gain exclusive access atomically w.r.t. other exclusive accesses. * blkdev_put() is similarly extended. It now takes @mode argument and if @FMODE_EXCL is set, it releases an exclusive access. Also, when the last exclusive claim is released, the holder/slave symlinks are removed automatically. * bd_claim/release() and close_bdev_exclusive() are no longer necessary and either made static or removed. * bd_link_disk_holder() remains the same but bd_unlink_disk_holder() is no longer necessary and removed. * open_bdev_exclusive() becomes a simple wrapper around lookup_bdev() and blkdev_get(). It also has an unexpected extra bdev_read_only() test which probably should be moved into blkdev_get(). * open_by_devnum() is modified to take @holder argument and pass it to blkdev_get(). Most of bdev open/close operations are unified into blkdev_get/put() and most exclusive accesses are tested atomically at the open time (as it should). This cleans up code and removes some, both valid and invalid, but unnecessary all the same, corner cases. open_bdev_exclusive() and open_by_devnum() can use further cleanup - rename to blkdev_get_by_path() and blkdev_get_by_devt() and drop special features. Well, let's leave them for another day. Most conversions are straight-forward. drbd conversion is a bit more involved as there was some reordering, but the logic should stay the same. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Neil Brown <neilb@suse.de> Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Acked-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Philipp Reisner <philipp.reisner@linbit.com> Cc: Peter Osterlund <petero2@telia.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Jan Kara <jack@suse.cz> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <joel.becker@oracle.com> Cc: Alex Elder <aelder@sgi.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: dm-devel@redhat.com Cc: drbd-dev@lists.linbit.com Cc: Leo Chen <leochen@broadcom.com> Cc: Scott Branden <sbranden@broadcom.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Joern Engel <joern@logfs.org> Cc: reiserfs-devel@vger.kernel.org Cc: Alexander Viro <viro@zeniv.linux.org.uk>
2010-11-13 10:55:17 +00:00
if ((ret = blkdev_get(pd->bdev, FMODE_READ | FMODE_EXCL, pd)))
goto out;
if ((ret = pkt_get_last_written(pd, &lba))) {
printk(DRIVER_NAME": pkt_get_last_written failed\n");
block: make blkdev_get/put() handle exclusive access Over time, block layer has accumulated a set of APIs dealing with bdev open, close, claim and release. * blkdev_get/put() are the primary open and close functions. * bd_claim/release() deal with exclusive open. * open/close_bdev_exclusive() are combination of open and claim and the other way around, respectively. * bd_link/unlink_disk_holder() to create and remove holder/slave symlinks. * open_by_devnum() wraps bdget() + blkdev_get(). The interface is a bit confusing and the decoupling of open and claim makes it impossible to properly guarantee exclusive access as in-kernel open + claim sequence can disturb the existing exclusive open even before the block layer knows the current open if for another exclusive access. Reorganize the interface such that, * blkdev_get() is extended to include exclusive access management. @holder argument is added and, if is @FMODE_EXCL specified, it will gain exclusive access atomically w.r.t. other exclusive accesses. * blkdev_put() is similarly extended. It now takes @mode argument and if @FMODE_EXCL is set, it releases an exclusive access. Also, when the last exclusive claim is released, the holder/slave symlinks are removed automatically. * bd_claim/release() and close_bdev_exclusive() are no longer necessary and either made static or removed. * bd_link_disk_holder() remains the same but bd_unlink_disk_holder() is no longer necessary and removed. * open_bdev_exclusive() becomes a simple wrapper around lookup_bdev() and blkdev_get(). It also has an unexpected extra bdev_read_only() test which probably should be moved into blkdev_get(). * open_by_devnum() is modified to take @holder argument and pass it to blkdev_get(). Most of bdev open/close operations are unified into blkdev_get/put() and most exclusive accesses are tested atomically at the open time (as it should). This cleans up code and removes some, both valid and invalid, but unnecessary all the same, corner cases. open_bdev_exclusive() and open_by_devnum() can use further cleanup - rename to blkdev_get_by_path() and blkdev_get_by_devt() and drop special features. Well, let's leave them for another day. Most conversions are straight-forward. drbd conversion is a bit more involved as there was some reordering, but the logic should stay the same. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Neil Brown <neilb@suse.de> Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Acked-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Philipp Reisner <philipp.reisner@linbit.com> Cc: Peter Osterlund <petero2@telia.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Jan Kara <jack@suse.cz> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <joel.becker@oracle.com> Cc: Alex Elder <aelder@sgi.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: dm-devel@redhat.com Cc: drbd-dev@lists.linbit.com Cc: Leo Chen <leochen@broadcom.com> Cc: Scott Branden <sbranden@broadcom.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Joern Engel <joern@logfs.org> Cc: reiserfs-devel@vger.kernel.org Cc: Alexander Viro <viro@zeniv.linux.org.uk>
2010-11-13 10:55:17 +00:00
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) {
if ((ret = pkt_open_write(pd)))
block: make blkdev_get/put() handle exclusive access Over time, block layer has accumulated a set of APIs dealing with bdev open, close, claim and release. * blkdev_get/put() are the primary open and close functions. * bd_claim/release() deal with exclusive open. * open/close_bdev_exclusive() are combination of open and claim and the other way around, respectively. * bd_link/unlink_disk_holder() to create and remove holder/slave symlinks. * open_by_devnum() wraps bdget() + blkdev_get(). The interface is a bit confusing and the decoupling of open and claim makes it impossible to properly guarantee exclusive access as in-kernel open + claim sequence can disturb the existing exclusive open even before the block layer knows the current open if for another exclusive access. Reorganize the interface such that, * blkdev_get() is extended to include exclusive access management. @holder argument is added and, if is @FMODE_EXCL specified, it will gain exclusive access atomically w.r.t. other exclusive accesses. * blkdev_put() is similarly extended. It now takes @mode argument and if @FMODE_EXCL is set, it releases an exclusive access. Also, when the last exclusive claim is released, the holder/slave symlinks are removed automatically. * bd_claim/release() and close_bdev_exclusive() are no longer necessary and either made static or removed. * bd_link_disk_holder() remains the same but bd_unlink_disk_holder() is no longer necessary and removed. * open_bdev_exclusive() becomes a simple wrapper around lookup_bdev() and blkdev_get(). It also has an unexpected extra bdev_read_only() test which probably should be moved into blkdev_get(). * open_by_devnum() is modified to take @holder argument and pass it to blkdev_get(). Most of bdev open/close operations are unified into blkdev_get/put() and most exclusive accesses are tested atomically at the open time (as it should). This cleans up code and removes some, both valid and invalid, but unnecessary all the same, corner cases. open_bdev_exclusive() and open_by_devnum() can use further cleanup - rename to blkdev_get_by_path() and blkdev_get_by_devt() and drop special features. Well, let's leave them for another day. Most conversions are straight-forward. drbd conversion is a bit more involved as there was some reordering, but the logic should stay the same. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Neil Brown <neilb@suse.de> Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Acked-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Philipp Reisner <philipp.reisner@linbit.com> Cc: Peter Osterlund <petero2@telia.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Jan Kara <jack@suse.cz> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <joel.becker@oracle.com> Cc: Alex Elder <aelder@sgi.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: dm-devel@redhat.com Cc: drbd-dev@lists.linbit.com Cc: Leo Chen <leochen@broadcom.com> Cc: Scott Branden <sbranden@broadcom.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Joern Engel <joern@logfs.org> Cc: reiserfs-devel@vger.kernel.org Cc: Alexander Viro <viro@zeniv.linux.org.uk>
2010-11-13 10:55:17 +00:00
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.
*/
spin_lock_irq(q->queue_lock);
blk_queue_max_hw_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)))
block: make blkdev_get/put() handle exclusive access Over time, block layer has accumulated a set of APIs dealing with bdev open, close, claim and release. * blkdev_get/put() are the primary open and close functions. * bd_claim/release() deal with exclusive open. * open/close_bdev_exclusive() are combination of open and claim and the other way around, respectively. * bd_link/unlink_disk_holder() to create and remove holder/slave symlinks. * open_by_devnum() wraps bdget() + blkdev_get(). The interface is a bit confusing and the decoupling of open and claim makes it impossible to properly guarantee exclusive access as in-kernel open + claim sequence can disturb the existing exclusive open even before the block layer knows the current open if for another exclusive access. Reorganize the interface such that, * blkdev_get() is extended to include exclusive access management. @holder argument is added and, if is @FMODE_EXCL specified, it will gain exclusive access atomically w.r.t. other exclusive accesses. * blkdev_put() is similarly extended. It now takes @mode argument and if @FMODE_EXCL is set, it releases an exclusive access. Also, when the last exclusive claim is released, the holder/slave symlinks are removed automatically. * bd_claim/release() and close_bdev_exclusive() are no longer necessary and either made static or removed. * bd_link_disk_holder() remains the same but bd_unlink_disk_holder() is no longer necessary and removed. * open_bdev_exclusive() becomes a simple wrapper around lookup_bdev() and blkdev_get(). It also has an unexpected extra bdev_read_only() test which probably should be moved into blkdev_get(). * open_by_devnum() is modified to take @holder argument and pass it to blkdev_get(). Most of bdev open/close operations are unified into blkdev_get/put() and most exclusive accesses are tested atomically at the open time (as it should). This cleans up code and removes some, both valid and invalid, but unnecessary all the same, corner cases. open_bdev_exclusive() and open_by_devnum() can use further cleanup - rename to blkdev_get_by_path() and blkdev_get_by_devt() and drop special features. Well, let's leave them for another day. Most conversions are straight-forward. drbd conversion is a bit more involved as there was some reordering, but the logic should stay the same. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Neil Brown <neilb@suse.de> Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Acked-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Philipp Reisner <philipp.reisner@linbit.com> Cc: Peter Osterlund <petero2@telia.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Jan Kara <jack@suse.cz> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <joel.becker@oracle.com> Cc: Alex Elder <aelder@sgi.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: dm-devel@redhat.com Cc: drbd-dev@lists.linbit.com Cc: Leo Chen <leochen@broadcom.com> Cc: Scott Branden <sbranden@broadcom.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Joern Engel <joern@logfs.org> Cc: reiserfs-devel@vger.kernel.org Cc: Alexander Viro <viro@zeniv.linux.org.uk>
2010-11-13 10:55:17 +00:00
goto out_putdev;
if (write) {
if (!pkt_grow_pktlist(pd, CONFIG_CDROM_PKTCDVD_BUFFERS)) {
printk(DRIVER_NAME": not enough memory for buffers\n");
ret = -ENOMEM;
block: make blkdev_get/put() handle exclusive access Over time, block layer has accumulated a set of APIs dealing with bdev open, close, claim and release. * blkdev_get/put() are the primary open and close functions. * bd_claim/release() deal with exclusive open. * open/close_bdev_exclusive() are combination of open and claim and the other way around, respectively. * bd_link/unlink_disk_holder() to create and remove holder/slave symlinks. * open_by_devnum() wraps bdget() + blkdev_get(). The interface is a bit confusing and the decoupling of open and claim makes it impossible to properly guarantee exclusive access as in-kernel open + claim sequence can disturb the existing exclusive open even before the block layer knows the current open if for another exclusive access. Reorganize the interface such that, * blkdev_get() is extended to include exclusive access management. @holder argument is added and, if is @FMODE_EXCL specified, it will gain exclusive access atomically w.r.t. other exclusive accesses. * blkdev_put() is similarly extended. It now takes @mode argument and if @FMODE_EXCL is set, it releases an exclusive access. Also, when the last exclusive claim is released, the holder/slave symlinks are removed automatically. * bd_claim/release() and close_bdev_exclusive() are no longer necessary and either made static or removed. * bd_link_disk_holder() remains the same but bd_unlink_disk_holder() is no longer necessary and removed. * open_bdev_exclusive() becomes a simple wrapper around lookup_bdev() and blkdev_get(). It also has an unexpected extra bdev_read_only() test which probably should be moved into blkdev_get(). * open_by_devnum() is modified to take @holder argument and pass it to blkdev_get(). Most of bdev open/close operations are unified into blkdev_get/put() and most exclusive accesses are tested atomically at the open time (as it should). This cleans up code and removes some, both valid and invalid, but unnecessary all the same, corner cases. open_bdev_exclusive() and open_by_devnum() can use further cleanup - rename to blkdev_get_by_path() and blkdev_get_by_devt() and drop special features. Well, let's leave them for another day. Most conversions are straight-forward. drbd conversion is a bit more involved as there was some reordering, but the logic should stay the same. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Neil Brown <neilb@suse.de> Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Acked-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Philipp Reisner <philipp.reisner@linbit.com> Cc: Peter Osterlund <petero2@telia.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Jan Kara <jack@suse.cz> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <joel.becker@oracle.com> Cc: Alex Elder <aelder@sgi.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: dm-devel@redhat.com Cc: drbd-dev@lists.linbit.com Cc: Leo Chen <leochen@broadcom.com> Cc: Scott Branden <sbranden@broadcom.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Joern Engel <joern@logfs.org> Cc: reiserfs-devel@vger.kernel.org Cc: Alexander Viro <viro@zeniv.linux.org.uk>
2010-11-13 10:55:17 +00:00
goto out_putdev;
}
printk(DRIVER_NAME": %lukB available on disc\n", lba << 1);
}
return 0;
out_putdev:
block: make blkdev_get/put() handle exclusive access Over time, block layer has accumulated a set of APIs dealing with bdev open, close, claim and release. * blkdev_get/put() are the primary open and close functions. * bd_claim/release() deal with exclusive open. * open/close_bdev_exclusive() are combination of open and claim and the other way around, respectively. * bd_link/unlink_disk_holder() to create and remove holder/slave symlinks. * open_by_devnum() wraps bdget() + blkdev_get(). The interface is a bit confusing and the decoupling of open and claim makes it impossible to properly guarantee exclusive access as in-kernel open + claim sequence can disturb the existing exclusive open even before the block layer knows the current open if for another exclusive access. Reorganize the interface such that, * blkdev_get() is extended to include exclusive access management. @holder argument is added and, if is @FMODE_EXCL specified, it will gain exclusive access atomically w.r.t. other exclusive accesses. * blkdev_put() is similarly extended. It now takes @mode argument and if @FMODE_EXCL is set, it releases an exclusive access. Also, when the last exclusive claim is released, the holder/slave symlinks are removed automatically. * bd_claim/release() and close_bdev_exclusive() are no longer necessary and either made static or removed. * bd_link_disk_holder() remains the same but bd_unlink_disk_holder() is no longer necessary and removed. * open_bdev_exclusive() becomes a simple wrapper around lookup_bdev() and blkdev_get(). It also has an unexpected extra bdev_read_only() test which probably should be moved into blkdev_get(). * open_by_devnum() is modified to take @holder argument and pass it to blkdev_get(). Most of bdev open/close operations are unified into blkdev_get/put() and most exclusive accesses are tested atomically at the open time (as it should). This cleans up code and removes some, both valid and invalid, but unnecessary all the same, corner cases. open_bdev_exclusive() and open_by_devnum() can use further cleanup - rename to blkdev_get_by_path() and blkdev_get_by_devt() and drop special features. Well, let's leave them for another day. Most conversions are straight-forward. drbd conversion is a bit more involved as there was some reordering, but the logic should stay the same. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Neil Brown <neilb@suse.de> Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Acked-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Philipp Reisner <philipp.reisner@linbit.com> Cc: Peter Osterlund <petero2@telia.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Jan Kara <jack@suse.cz> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <joel.becker@oracle.com> Cc: Alex Elder <aelder@sgi.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: dm-devel@redhat.com Cc: drbd-dev@lists.linbit.com Cc: Leo Chen <leochen@broadcom.com> Cc: Scott Branden <sbranden@broadcom.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Joern Engel <joern@logfs.org> Cc: reiserfs-devel@vger.kernel.org Cc: Alexander Viro <viro@zeniv.linux.org.uk>
2010-11-13 10:55:17 +00:00
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))
DPRINTK(DRIVER_NAME": %s not flushing cache\n", pd->name);
pkt_lock_door(pd, 0);
pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
block: make blkdev_get/put() handle exclusive access Over time, block layer has accumulated a set of APIs dealing with bdev open, close, claim and release. * blkdev_get/put() are the primary open and close functions. * bd_claim/release() deal with exclusive open. * open/close_bdev_exclusive() are combination of open and claim and the other way around, respectively. * bd_link/unlink_disk_holder() to create and remove holder/slave symlinks. * open_by_devnum() wraps bdget() + blkdev_get(). The interface is a bit confusing and the decoupling of open and claim makes it impossible to properly guarantee exclusive access as in-kernel open + claim sequence can disturb the existing exclusive open even before the block layer knows the current open if for another exclusive access. Reorganize the interface such that, * blkdev_get() is extended to include exclusive access management. @holder argument is added and, if is @FMODE_EXCL specified, it will gain exclusive access atomically w.r.t. other exclusive accesses. * blkdev_put() is similarly extended. It now takes @mode argument and if @FMODE_EXCL is set, it releases an exclusive access. Also, when the last exclusive claim is released, the holder/slave symlinks are removed automatically. * bd_claim/release() and close_bdev_exclusive() are no longer necessary and either made static or removed. * bd_link_disk_holder() remains the same but bd_unlink_disk_holder() is no longer necessary and removed. * open_bdev_exclusive() becomes a simple wrapper around lookup_bdev() and blkdev_get(). It also has an unexpected extra bdev_read_only() test which probably should be moved into blkdev_get(). * open_by_devnum() is modified to take @holder argument and pass it to blkdev_get(). Most of bdev open/close operations are unified into blkdev_get/put() and most exclusive accesses are tested atomically at the open time (as it should). This cleans up code and removes some, both valid and invalid, but unnecessary all the same, corner cases. open_bdev_exclusive() and open_by_devnum() can use further cleanup - rename to blkdev_get_by_path() and blkdev_get_by_devt() and drop special features. Well, let's leave them for another day. Most conversions are straight-forward. drbd conversion is a bit more involved as there was some reordering, but the logic should stay the same. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Neil Brown <neilb@suse.de> Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Acked-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Philipp Reisner <philipp.reisner@linbit.com> Cc: Peter Osterlund <petero2@telia.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Jan Kara <jack@suse.cz> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <joel.becker@oracle.com> Cc: Alex Elder <aelder@sgi.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: dm-devel@redhat.com Cc: drbd-dev@lists.linbit.com Cc: Leo Chen <leochen@broadcom.com> Cc: Scott Branden <sbranden@broadcom.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Joern Engel <joern@logfs.org> Cc: reiserfs-devel@vger.kernel.org Cc: Alexander Viro <viro@zeniv.linux.org.uk>
2010-11-13 10:55:17 +00:00
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;
return pkt_devs[dev_minor];
}
static int pkt_open(struct block_device *bdev, fmode_t mode)
{
struct pktcdvd_device *pd = NULL;
int ret;
VPRINTK(DRIVER_NAME": entering open\n");
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:
VPRINTK(DRIVER_NAME": failed open (%d)\n", ret);
mutex_unlock(&ctl_mutex);
mutex_unlock(&pktcdvd_mutex);
return ret;
}
static int pkt_close(struct gendisk *disk, fmode_t mode)
{
struct pktcdvd_device *pd = disk->private_data;
int ret = 0;
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);
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, 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)) {
bio_list_add(&pkt->orig_bios, bio);
pkt->write_size += bio->bi_size / CD_FRAMESIZE;
if ((pkt->write_size >= pkt->frames) &&
(pkt->state == PACKET_WAITING_STATE)) {
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, 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);
}
return 0;
end_io:
bio_io_error(bio);
return 0;
}
static int pkt_merge_bvec(struct request_queue *q, struct bvec_merge_data *bmd,
struct bio_vec *bvec)
{
struct pktcdvd_device *pd = q->queuedata;
sector_t zone = ZONE(bmd->bi_sector, pd);
int used = ((bmd->bi_sector - zone) << 9) + bmd->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 - bmd->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_logical_block_size(q, CD_FRAMESIZE);
blk_queue_max_hw_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 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;
block: make blkdev_get/put() handle exclusive access Over time, block layer has accumulated a set of APIs dealing with bdev open, close, claim and release. * blkdev_get/put() are the primary open and close functions. * bd_claim/release() deal with exclusive open. * open/close_bdev_exclusive() are combination of open and claim and the other way around, respectively. * bd_link/unlink_disk_holder() to create and remove holder/slave symlinks. * open_by_devnum() wraps bdget() + blkdev_get(). The interface is a bit confusing and the decoupling of open and claim makes it impossible to properly guarantee exclusive access as in-kernel open + claim sequence can disturb the existing exclusive open even before the block layer knows the current open if for another exclusive access. Reorganize the interface such that, * blkdev_get() is extended to include exclusive access management. @holder argument is added and, if is @FMODE_EXCL specified, it will gain exclusive access atomically w.r.t. other exclusive accesses. * blkdev_put() is similarly extended. It now takes @mode argument and if @FMODE_EXCL is set, it releases an exclusive access. Also, when the last exclusive claim is released, the holder/slave symlinks are removed automatically. * bd_claim/release() and close_bdev_exclusive() are no longer necessary and either made static or removed. * bd_link_disk_holder() remains the same but bd_unlink_disk_holder() is no longer necessary and removed. * open_bdev_exclusive() becomes a simple wrapper around lookup_bdev() and blkdev_get(). It also has an unexpected extra bdev_read_only() test which probably should be moved into blkdev_get(). * open_by_devnum() is modified to take @holder argument and pass it to blkdev_get(). Most of bdev open/close operations are unified into blkdev_get/put() and most exclusive accesses are tested atomically at the open time (as it should). This cleans up code and removes some, both valid and invalid, but unnecessary all the same, corner cases. open_bdev_exclusive() and open_by_devnum() can use further cleanup - rename to blkdev_get_by_path() and blkdev_get_by_devt() and drop special features. Well, let's leave them for another day. Most conversions are straight-forward. drbd conversion is a bit more involved as there was some reordering, but the logic should stay the same. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Neil Brown <neilb@suse.de> Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Acked-by: Mike Snitzer <snitzer@redhat.com> Acked-by: Philipp Reisner <philipp.reisner@linbit.com> Cc: Peter Osterlund <petero2@telia.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Jan Kara <jack@suse.cz> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andreas Dilger <adilger.kernel@dilger.ca> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <joel.becker@oracle.com> Cc: Alex Elder <aelder@sgi.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: dm-devel@redhat.com Cc: drbd-dev@lists.linbit.com Cc: Leo Chen <leochen@broadcom.com> Cc: Scott Branden <sbranden@broadcom.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Dave Kleikamp <shaggy@linux.vnet.ibm.com> Cc: Joern Engel <joern@logfs.org> Cc: reiserfs-devel@vger.kernel.org Cc: Alexander Viro <viro@zeniv.linux.org.uk>
2010-11-13 10:55:17 +00:00
ret = blkdev_get(bdev, FMODE_READ | FMODE_NDELAY, NULL);
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_data(pd->name, 0, pkt_proc, &pkt_proc_fops, pd);
DPRINTK(DRIVER_NAME": writer %s mapped to %s\n", pd->name, 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;
VPRINTK("pkt_ioctl: 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);
/* fallthru */
/*
* 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:
VPRINTK(DRIVER_NAME": Unknown ioctl for %s (%x)\n", pd->name, 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 const struct block_device_operations pktcdvd_ops = {
.owner = THIS_MODULE,
.open = pkt_open,
.release = pkt_close,
.ioctl = pkt_ioctl,
.check_events = pkt_check_events,
};
static char *pktcdvd_devnode(struct gendisk *gd, mode_t *mode)
{
return kasprintf(GFP_KERNEL, "pktcdvd/%s", gd->disk_name);
}
/*
* 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);
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;
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->devnode = pktcdvd_devnode;
disk->private_data = pd;
disk->queue = blk_alloc_queue(GFP_KERNEL);
if (!disk->queue)
goto out_mem2;
pd->pkt_dev = MKDEV(pktdev_major, idx);
ret = pkt_new_dev(pd, dev);
if (ret)
goto out_new_dev;
/* inherit events of the host device */
disk->events = pd->bdev->bd_disk->events;
disk->async_events = pd->bdev->bd_disk->async_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_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, FMODE_READ | FMODE_NDELAY);
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 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: automatically add .llseek fop All file_operations should get a .llseek operation so we can make nonseekable_open the default for future file operations without a .llseek pointer. The three cases that we can automatically detect are no_llseek, seq_lseek and default_llseek. For cases where we can we can automatically prove that the file offset is always ignored, we use noop_llseek, which maintains the current behavior of not returning an error from a seek. New drivers should normally not use noop_llseek but instead use no_llseek and call nonseekable_open at open time. Existing drivers can be converted to do the same when the maintainer knows for certain that no user code relies on calling seek on the device file. The generated code is often incorrectly indented and right now contains comments that clarify for each added line why a specific variant was chosen. In the version that gets submitted upstream, the comments will be gone and I will manually fix the indentation, because there does not seem to be a way to do that using coccinelle. Some amount of new code is currently sitting in linux-next that should get the same modifications, which I will do at the end of the merge window. Many thanks to Julia Lawall for helping me learn to write a semantic patch that does all this. ===== begin semantic patch ===== // This adds an llseek= method to all file operations, // as a preparation for making no_llseek the default. // // The rules are // - use no_llseek explicitly if we do nonseekable_open // - use seq_lseek for sequential files // - use default_llseek if we know we access f_pos // - use noop_llseek if we know we don't access f_pos, // but we still want to allow users to call lseek // @ open1 exists @ identifier nested_open; @@ nested_open(...) { <+... nonseekable_open(...) ...+> } @ open exists@ identifier open_f; identifier i, f; identifier open1.nested_open; @@ int open_f(struct inode *i, struct file *f) { <+... ( nonseekable_open(...) | nested_open(...) ) ...+> } @ read disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ read_no_fpos disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { ... when != off } @ write @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ write_no_fpos @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { ... when != off } @ fops0 @ identifier fops; @@ struct file_operations fops = { ... }; @ has_llseek depends on fops0 @ identifier fops0.fops; identifier llseek_f; @@ struct file_operations fops = { ... .llseek = llseek_f, ... }; @ has_read depends on fops0 @ identifier fops0.fops; identifier read_f; @@ struct file_operations fops = { ... .read = read_f, ... }; @ has_write depends on fops0 @ identifier fops0.fops; identifier write_f; @@ struct file_operations fops = { ... .write = write_f, ... }; @ has_open depends on fops0 @ identifier fops0.fops; identifier open_f; @@ struct file_operations fops = { ... .open = open_f, ... }; // use no_llseek if we call nonseekable_open //////////////////////////////////////////// @ nonseekable1 depends on !has_llseek && has_open @ identifier fops0.fops; identifier nso ~= "nonseekable_open"; @@ struct file_operations fops = { ... .open = nso, ... +.llseek = no_llseek, /* nonseekable */ }; @ nonseekable2 depends on !has_llseek @ identifier fops0.fops; identifier open.open_f; @@ struct file_operations fops = { ... .open = open_f, ... +.llseek = no_llseek, /* open uses nonseekable */ }; // use seq_lseek for sequential files ///////////////////////////////////// @ seq depends on !has_llseek @ identifier fops0.fops; identifier sr ~= "seq_read"; @@ struct file_operations fops = { ... .read = sr, ... +.llseek = seq_lseek, /* we have seq_read */ }; // use default_llseek if there is a readdir /////////////////////////////////////////// @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier readdir_e; @@ // any other fop is used that changes pos struct file_operations fops = { ... .readdir = readdir_e, ... +.llseek = default_llseek, /* readdir is present */ }; // use default_llseek if at least one of read/write touches f_pos ///////////////////////////////////////////////////////////////// @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read.read_f; @@ // read fops use offset struct file_operations fops = { ... .read = read_f, ... +.llseek = default_llseek, /* read accesses f_pos */ }; @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, ... + .llseek = default_llseek, /* write accesses f_pos */ }; // Use noop_llseek if neither read nor write accesses f_pos /////////////////////////////////////////////////////////// @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; identifier write_no_fpos.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, .read = read_f, ... +.llseek = noop_llseek, /* read and write both use no f_pos */ }; @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write_no_fpos.write_f; @@ struct file_operations fops = { ... .write = write_f, ... +.llseek = noop_llseek, /* write uses no f_pos */ }; @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; @@ struct file_operations fops = { ... .read = read_f, ... +.llseek = noop_llseek, /* read uses no f_pos */ }; @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; @@ struct file_operations fops = { ... +.llseek = noop_llseek, /* no read or write fn */ }; ===== End semantic patch ===== Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Julia Lawall <julia@diku.dk> Cc: Christoph Hellwig <hch@infradead.org>
2010-08-15 16:52:59 +00:00
.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);
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/"DRIVER_NAME, NULL);
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/"DRIVER_NAME, NULL);
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);