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Merge branch 'for-2.6.38/event-handling' into for-2.6.38/core

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This commit is contained in:
Jens Axboe 2011-01-13 14:47:54 +01:00
commit 81c5e2ae33
14 changed files with 735 additions and 231 deletions
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544
block/genhd.c
View File

@ -18,6 +18,7 @@
#include <linux/buffer_head.h>
#include <linux/mutex.h>
#include <linux/idr.h>
#include <linux/log2.h>
#include "blk.h"
@ -35,6 +36,10 @@ static DEFINE_IDR(ext_devt_idr);
static struct device_type disk_type;
static void disk_add_events(struct gendisk *disk);
static void disk_del_events(struct gendisk *disk);
static void disk_release_events(struct gendisk *disk);
/**
* disk_get_part - get partition
* @disk: disk to look partition from
@ -502,6 +507,64 @@ static int exact_lock(dev_t devt, void *data)
return 0;
}
void register_disk(struct gendisk *disk)
{
struct device *ddev = disk_to_dev(disk);
struct block_device *bdev;
struct disk_part_iter piter;
struct hd_struct *part;
int err;
ddev->parent = disk->driverfs_dev;
dev_set_name(ddev, disk->disk_name);
/* delay uevents, until we scanned partition table */
dev_set_uevent_suppress(ddev, 1);
if (device_add(ddev))
return;
if (!sysfs_deprecated) {
err = sysfs_create_link(block_depr, &ddev->kobj,
kobject_name(&ddev->kobj));
if (err) {
device_del(ddev);
return;
}
}
disk->part0.holder_dir = kobject_create_and_add("holders", &ddev->kobj);
disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj);
/* No minors to use for partitions */
if (!disk_partitionable(disk))
goto exit;
/* No such device (e.g., media were just removed) */
if (!get_capacity(disk))
goto exit;
bdev = bdget_disk(disk, 0);
if (!bdev)
goto exit;
bdev->bd_invalidated = 1;
err = blkdev_get(bdev, FMODE_READ, NULL);
if (err < 0)
goto exit;
blkdev_put(bdev, FMODE_READ);
exit:
/* announce disk after possible partitions are created */
dev_set_uevent_suppress(ddev, 0);
kobject_uevent(&ddev->kobj, KOBJ_ADD);
/* announce possible partitions */
disk_part_iter_init(&piter, disk, 0);
while ((part = disk_part_iter_next(&piter)))
kobject_uevent(&part_to_dev(part)->kobj, KOBJ_ADD);
disk_part_iter_exit(&piter);
}
/**
* add_disk - add partitioning information to kernel list
* @disk: per-device partitioning information
@ -551,18 +614,48 @@ void add_disk(struct gendisk *disk)
retval = sysfs_create_link(&disk_to_dev(disk)->kobj, &bdi->dev->kobj,
"bdi");
WARN_ON(retval);
disk_add_events(disk);
}
EXPORT_SYMBOL(add_disk);
EXPORT_SYMBOL(del_gendisk); /* in partitions/check.c */
void unlink_gendisk(struct gendisk *disk)
void del_gendisk(struct gendisk *disk)
{
struct disk_part_iter piter;
struct hd_struct *part;
disk_del_events(disk);
/* invalidate stuff */
disk_part_iter_init(&piter, disk,
DISK_PITER_INCL_EMPTY | DISK_PITER_REVERSE);
while ((part = disk_part_iter_next(&piter))) {
invalidate_partition(disk, part->partno);
delete_partition(disk, part->partno);
}
disk_part_iter_exit(&piter);
invalidate_partition(disk, 0);
blk_free_devt(disk_to_dev(disk)->devt);
set_capacity(disk, 0);
disk->flags &= ~GENHD_FL_UP;
sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi");
bdi_unregister(&disk->queue->backing_dev_info);
blk_unregister_queue(disk);
blk_unregister_region(disk_devt(disk), disk->minors);
part_stat_set_all(&disk->part0, 0);
disk->part0.stamp = 0;
kobject_put(disk->part0.holder_dir);
kobject_put(disk->slave_dir);
disk->driverfs_dev = NULL;
if (!sysfs_deprecated)
sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk)));
device_del(disk_to_dev(disk));
}
EXPORT_SYMBOL(del_gendisk);
/**
* get_gendisk - get partitioning information for a given device
@ -1005,6 +1098,7 @@ static void disk_release(struct device *dev)
{
struct gendisk *disk = dev_to_disk(dev);
disk_release_events(disk);
kfree(disk->random);
disk_replace_part_tbl(disk, NULL);
free_part_stats(&disk->part0);
@ -1110,29 +1204,6 @@ static int __init proc_genhd_init(void)
module_init(proc_genhd_init);
#endif /* CONFIG_PROC_FS */
static void media_change_notify_thread(struct work_struct *work)
{
struct gendisk *gd = container_of(work, struct gendisk, async_notify);
char event[] = "MEDIA_CHANGE=1";
char *envp[] = { event, NULL };
/*
* set enviroment vars to indicate which event this is for
* so that user space will know to go check the media status.
*/
kobject_uevent_env(&disk_to_dev(gd)->kobj, KOBJ_CHANGE, envp);
put_device(gd->driverfs_dev);
}
#if 0
void genhd_media_change_notify(struct gendisk *disk)
{
get_device(disk->driverfs_dev);
schedule_work(&disk->async_notify);
}
EXPORT_SYMBOL_GPL(genhd_media_change_notify);
#endif /* 0 */
dev_t blk_lookup_devt(const char *name, int partno)
{
dev_t devt = MKDEV(0, 0);
@ -1200,8 +1271,6 @@ struct gendisk *alloc_disk_node(int minors, int node_id)
disk_to_dev(disk)->class = &block_class;
disk_to_dev(disk)->type = &disk_type;
device_initialize(disk_to_dev(disk));
INIT_WORK(&disk->async_notify,
media_change_notify_thread);
}
return disk;
}
@ -1293,3 +1362,422 @@ int invalidate_partition(struct gendisk *disk, int partno)
}
EXPORT_SYMBOL(invalidate_partition);
/*
* Disk events - monitor disk events like media change and eject request.
*/
struct disk_events {
struct list_head node; /* all disk_event's */
struct gendisk *disk; /* the associated disk */
spinlock_t lock;
int block; /* event blocking depth */
unsigned int pending; /* events already sent out */
unsigned int clearing; /* events being cleared */
long poll_msecs; /* interval, -1 for default */
struct delayed_work dwork;
};
static const char *disk_events_strs[] = {
[ilog2(DISK_EVENT_MEDIA_CHANGE)] = "media_change",
[ilog2(DISK_EVENT_EJECT_REQUEST)] = "eject_request",
};
static char *disk_uevents[] = {
[ilog2(DISK_EVENT_MEDIA_CHANGE)] = "DISK_MEDIA_CHANGE=1",
[ilog2(DISK_EVENT_EJECT_REQUEST)] = "DISK_EJECT_REQUEST=1",
};
/* list of all disk_events */
static DEFINE_MUTEX(disk_events_mutex);
static LIST_HEAD(disk_events);
/* disable in-kernel polling by default */
static unsigned long disk_events_dfl_poll_msecs = 0;
static unsigned long disk_events_poll_jiffies(struct gendisk *disk)
{
struct disk_events *ev = disk->ev;
long intv_msecs = 0;
/*
* If device-specific poll interval is set, always use it. If
* the default is being used, poll iff there are events which
* can't be monitored asynchronously.
*/
if (ev->poll_msecs >= 0)
intv_msecs = ev->poll_msecs;
else if (disk->events & ~disk->async_events)
intv_msecs = disk_events_dfl_poll_msecs;
return msecs_to_jiffies(intv_msecs);
}
static void __disk_block_events(struct gendisk *disk, bool sync)
{
struct disk_events *ev = disk->ev;
unsigned long flags;
bool cancel;
spin_lock_irqsave(&ev->lock, flags);
cancel = !ev->block++;
spin_unlock_irqrestore(&ev->lock, flags);
if (cancel) {
if (sync)
cancel_delayed_work_sync(&disk->ev->dwork);
else
cancel_delayed_work(&disk->ev->dwork);
}
}
static void __disk_unblock_events(struct gendisk *disk, bool check_now)
{
struct disk_events *ev = disk->ev;
unsigned long intv;
unsigned long flags;
spin_lock_irqsave(&ev->lock, flags);
if (WARN_ON_ONCE(ev->block <= 0))
goto out_unlock;
if (--ev->block)
goto out_unlock;
/*
* Not exactly a latency critical operation, set poll timer
* slack to 25% and kick event check.
*/
intv = disk_events_poll_jiffies(disk);
set_timer_slack(&ev->dwork.timer, intv / 4);
if (check_now)
queue_delayed_work(system_nrt_wq, &ev->dwork, 0);
else if (intv)
queue_delayed_work(system_nrt_wq, &ev->dwork, intv);
out_unlock:
spin_unlock_irqrestore(&ev->lock, flags);
}
/**
* disk_block_events - block and flush disk event checking
* @disk: disk to block events for
*
* On return from this function, it is guaranteed that event checking
* isn't in progress and won't happen until unblocked by
* disk_unblock_events(). Events blocking is counted and the actual
* unblocking happens after the matching number of unblocks are done.
*
* Note that this intentionally does not block event checking from
* disk_clear_events().
*
* CONTEXT:
* Might sleep.
*/
void disk_block_events(struct gendisk *disk)
{
if (disk->ev)
__disk_block_events(disk, true);
}
/**
* disk_unblock_events - unblock disk event checking
* @disk: disk to unblock events for
*
* Undo disk_block_events(). When the block count reaches zero, it
* starts events polling if configured.
*
* CONTEXT:
* Don't care. Safe to call from irq context.
*/
void disk_unblock_events(struct gendisk *disk)
{
if (disk->ev)
__disk_unblock_events(disk, true);
}
/**
* disk_check_events - schedule immediate event checking
* @disk: disk to check events for
*
* Schedule immediate event checking on @disk if not blocked.
*
* CONTEXT:
* Don't care. Safe to call from irq context.
*/
void disk_check_events(struct gendisk *disk)
{
if (disk->ev) {
__disk_block_events(disk, false);
__disk_unblock_events(disk, true);
}
}
EXPORT_SYMBOL_GPL(disk_check_events);
/**
* disk_clear_events - synchronously check, clear and return pending events
* @disk: disk to fetch and clear events from
* @mask: mask of events to be fetched and clearted
*
* Disk events are synchronously checked and pending events in @mask
* are cleared and returned. This ignores the block count.
*
* CONTEXT:
* Might sleep.
*/
unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask)
{
const struct block_device_operations *bdops = disk->fops;
struct disk_events *ev = disk->ev;
unsigned int pending;
if (!ev) {
/* for drivers still using the old ->media_changed method */
if ((mask & DISK_EVENT_MEDIA_CHANGE) &&
bdops->media_changed && bdops->media_changed(disk))
return DISK_EVENT_MEDIA_CHANGE;
return 0;
}
/* tell the workfn about the events being cleared */
spin_lock_irq(&ev->lock);
ev->clearing |= mask;
spin_unlock_irq(&ev->lock);
/* uncondtionally schedule event check and wait for it to finish */
__disk_block_events(disk, true);
queue_delayed_work(system_nrt_wq, &ev->dwork, 0);
flush_delayed_work(&ev->dwork);
__disk_unblock_events(disk, false);
/* then, fetch and clear pending events */
spin_lock_irq(&ev->lock);
WARN_ON_ONCE(ev->clearing & mask); /* cleared by workfn */
pending = ev->pending & mask;
ev->pending &= ~mask;
spin_unlock_irq(&ev->lock);
return pending;
}
static void disk_events_workfn(struct work_struct *work)
{
struct delayed_work *dwork = to_delayed_work(work);
struct disk_events *ev = container_of(dwork, struct disk_events, dwork);
struct gendisk *disk = ev->disk;
char *envp[ARRAY_SIZE(disk_uevents) + 1] = { };
unsigned int clearing = ev->clearing;
unsigned int events;
unsigned long intv;
int nr_events = 0, i;
/* check events */
events = disk->fops->check_events(disk, clearing);
/* accumulate pending events and schedule next poll if necessary */
spin_lock_irq(&ev->lock);
events &= ~ev->pending;
ev->pending |= events;
ev->clearing &= ~clearing;
intv = disk_events_poll_jiffies(disk);
if (!ev->block && intv)
queue_delayed_work(system_nrt_wq, &ev->dwork, intv);
spin_unlock_irq(&ev->lock);
/* tell userland about new events */
for (i = 0; i < ARRAY_SIZE(disk_uevents); i++)
if (events & (1 << i))
envp[nr_events++] = disk_uevents[i];
if (nr_events)
kobject_uevent_env(&disk_to_dev(disk)->kobj, KOBJ_CHANGE, envp);
}
/*
* A disk events enabled device has the following sysfs nodes under
* its /sys/block/X/ directory.
*
* events : list of all supported events
* events_async : list of events which can be detected w/o polling
* events_poll_msecs : polling interval, 0: disable, -1: system default
*/
static ssize_t __disk_events_show(unsigned int events, char *buf)
{
const char *delim = "";
ssize_t pos = 0;
int i;
for (i = 0; i < ARRAY_SIZE(disk_events_strs); i++)
if (events & (1 << i)) {
pos += sprintf(buf + pos, "%s%s",
delim, disk_events_strs[i]);
delim = " ";
}
if (pos)
pos += sprintf(buf + pos, "\n");
return pos;
}
static ssize_t disk_events_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct gendisk *disk = dev_to_disk(dev);
return __disk_events_show(disk->events, buf);
}
static ssize_t disk_events_async_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct gendisk *disk = dev_to_disk(dev);
return __disk_events_show(disk->async_events, buf);
}
static ssize_t disk_events_poll_msecs_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct gendisk *disk = dev_to_disk(dev);
return sprintf(buf, "%ld\n", disk->ev->poll_msecs);
}
static ssize_t disk_events_poll_msecs_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct gendisk *disk = dev_to_disk(dev);
long intv;
if (!count || !sscanf(buf, "%ld", &intv))
return -EINVAL;
if (intv < 0 && intv != -1)
return -EINVAL;
__disk_block_events(disk, true);
disk->ev->poll_msecs = intv;
__disk_unblock_events(disk, true);
return count;
}
static const DEVICE_ATTR(events, S_IRUGO, disk_events_show, NULL);
static const DEVICE_ATTR(events_async, S_IRUGO, disk_events_async_show, NULL);
static const DEVICE_ATTR(events_poll_msecs, S_IRUGO|S_IWUSR,
disk_events_poll_msecs_show,
disk_events_poll_msecs_store);
static const struct attribute *disk_events_attrs[] = {
&dev_attr_events.attr,
&dev_attr_events_async.attr,
&dev_attr_events_poll_msecs.attr,
NULL,
};
/*
* The default polling interval can be specified by the kernel
* parameter block.events_dfl_poll_msecs which defaults to 0
* (disable). This can also be modified runtime by writing to
* /sys/module/block/events_dfl_poll_msecs.
*/
static int disk_events_set_dfl_poll_msecs(const char *val,
const struct kernel_param *kp)
{
struct disk_events *ev;
int ret;
ret = param_set_ulong(val, kp);
if (ret < 0)
return ret;
mutex_lock(&disk_events_mutex);
list_for_each_entry(ev, &disk_events, node)
disk_check_events(ev->disk);
mutex_unlock(&disk_events_mutex);
return 0;
}
static const struct kernel_param_ops disk_events_dfl_poll_msecs_param_ops = {
.set = disk_events_set_dfl_poll_msecs,
.get = param_get_ulong,
};
#undef MODULE_PARAM_PREFIX
#define MODULE_PARAM_PREFIX "block."
module_param_cb(events_dfl_poll_msecs, &disk_events_dfl_poll_msecs_param_ops,
&disk_events_dfl_poll_msecs, 0644);
/*
* disk_{add|del|release}_events - initialize and destroy disk_events.
*/
static void disk_add_events(struct gendisk *disk)
{
struct disk_events *ev;
if (!disk->fops->check_events || !(disk->events | disk->async_events))
return;
ev = kzalloc(sizeof(*ev), GFP_KERNEL);
if (!ev) {
pr_warn("%s: failed to initialize events\n", disk->disk_name);
return;
}
if (sysfs_create_files(&disk_to_dev(disk)->kobj,
disk_events_attrs) < 0) {
pr_warn("%s: failed to create sysfs files for events\n",
disk->disk_name);
kfree(ev);
return;
}
disk->ev = ev;
INIT_LIST_HEAD(&ev->node);
ev->disk = disk;
spin_lock_init(&ev->lock);
ev->block = 1;
ev->poll_msecs = -1;
INIT_DELAYED_WORK(&ev->dwork, disk_events_workfn);
mutex_lock(&disk_events_mutex);
list_add_tail(&ev->node, &disk_events);
mutex_unlock(&disk_events_mutex);
/*
* Block count is initialized to 1 and the following initial
* unblock kicks it into action.
*/
__disk_unblock_events(disk, true);
}
static void disk_del_events(struct gendisk *disk)
{
if (!disk->ev)
return;
__disk_block_events(disk, true);
mutex_lock(&disk_events_mutex);
list_del_init(&disk->ev->node);
mutex_unlock(&disk_events_mutex);
sysfs_remove_files(&disk_to_dev(disk)->kobj, disk_events_attrs);
}
static void disk_release_events(struct gendisk *disk)
{
/* the block count should be 1 from disk_del_events() */
WARN_ON_ONCE(disk->ev && disk->ev->block != 1);
kfree(disk->ev);
}

56
drivers/cdrom/cdrom.c
View File

@ -1348,7 +1348,10 @@ static int cdrom_select_disc(struct cdrom_device_info *cdi, int slot)
if (!CDROM_CAN(CDC_SELECT_DISC))
return -EDRIVE_CANT_DO_THIS;
(void) cdi->ops->media_changed(cdi, slot);
if (cdi->ops->check_events)
cdi->ops->check_events(cdi, 0, slot);
else
cdi->ops->media_changed(cdi, slot);
if (slot == CDSL_NONE) {
/* set media changed bits, on both queues */
@ -1392,6 +1395,42 @@ static int cdrom_select_disc(struct cdrom_device_info *cdi, int slot)
return slot;
}
/*
* As cdrom implements an extra ioctl consumer for media changed
* event, it needs to buffer ->check_events() output, such that event
* is not lost for both the usual VFS and ioctl paths.
* cdi->{vfs|ioctl}_events are used to buffer pending events for each
* path.
*
* XXX: Locking is non-existent. cdi->ops->check_events() can be
* called in parallel and buffering fields are accessed without any
* exclusion. The original media_changed code had the same problem.
* It might be better to simply deprecate CDROM_MEDIA_CHANGED ioctl
* and remove this cruft altogether. It doesn't have much usefulness
* at this point.
*/
static void cdrom_update_events(struct cdrom_device_info *cdi,
unsigned int clearing)
{
unsigned int events;
events = cdi->ops->check_events(cdi, clearing, CDSL_CURRENT);
cdi->vfs_events |= events;
cdi->ioctl_events |= events;
}
unsigned int cdrom_check_events(struct cdrom_device_info *cdi,
unsigned int clearing)
{
unsigned int events;
cdrom_update_events(cdi, clearing);
events = cdi->vfs_events;
cdi->vfs_events = 0;
return events;
}
EXPORT_SYMBOL(cdrom_check_events);
/* We want to make media_changed accessible to the user through an
* ioctl. The main problem now is that we must double-buffer the
* low-level implementation, to assure that the VFS and the user both
@ -1403,15 +1442,26 @@ int media_changed(struct cdrom_device_info *cdi, int queue)
{
unsigned int mask = (1 << (queue & 1));
int ret = !!(cdi->mc_flags & mask);
bool changed;
if (!CDROM_CAN(CDC_MEDIA_CHANGED))
return ret;
return ret;
/* changed since last call? */
if (cdi->ops->media_changed(cdi, CDSL_CURRENT)) {
if (cdi->ops->check_events) {
BUG_ON(!queue); /* shouldn't be called from VFS path */
cdrom_update_events(cdi, DISK_EVENT_MEDIA_CHANGE);
changed = cdi->ioctl_events & DISK_EVENT_MEDIA_CHANGE;
cdi->ioctl_events = 0;
} else
changed = cdi->ops->media_changed(cdi, CDSL_CURRENT);
if (changed) {
cdi->mc_flags = 0x3; /* set bit on both queues */
ret |= 1;
cdi->media_written = 0;
}
cdi->mc_flags &= ~mask; /* clear bit */
return ret;
}

13
drivers/scsi/scsi_lib.c
View File

@ -1984,8 +1984,7 @@ EXPORT_SYMBOL(scsi_mode_sense);
* in.
*
* Returns zero if unsuccessful or an error if TUR failed. For
* removable media, a return of NOT_READY or UNIT_ATTENTION is
* translated to success, with the ->changed flag updated.
* removable media, UNIT_ATTENTION sets ->changed flag.
**/
int
scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries,
@ -2012,16 +2011,6 @@ scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries,
} while (scsi_sense_valid(sshdr) &&
sshdr->sense_key == UNIT_ATTENTION && --retries);
if (!sshdr)
/* could not allocate sense buffer, so can't process it */
return result;
if (sdev->removable && scsi_sense_valid(sshdr) &&
(sshdr->sense_key == UNIT_ATTENTION ||
sshdr->sense_key == NOT_READY)) {
sdev->changed = 1;
result = 0;
}
if (!sshdr_external)
kfree(sshdr);
return result;

10
drivers/scsi/sd.c
View File

@ -1045,15 +1045,7 @@ static int sd_media_changed(struct gendisk *disk)
sshdr);
}
/*
* Unable to test, unit probably not ready. This usually
* means there is no disc in the drive. Mark as changed,
* and we will figure it out later once the drive is
* available again.
*/
if (retval || (scsi_sense_valid(sshdr) &&
/* 0x3a is medium not present */
sshdr->asc == 0x3a)) {
if (retval) {
set_media_not_present(sdkp);
retval = 1;
goto out;

176
drivers/scsi/sr.c
View File

@ -104,14 +104,15 @@ static void sr_release(struct cdrom_device_info *);
static void get_sectorsize(struct scsi_cd *);
static void get_capabilities(struct scsi_cd *);
static int sr_media_change(struct cdrom_device_info *, int);
static unsigned int sr_check_events(struct cdrom_device_info *cdi,
unsigned int clearing, int slot);
static int sr_packet(struct cdrom_device_info *, struct packet_command *);
static struct cdrom_device_ops sr_dops = {
.open = sr_open,
.release = sr_release,
.drive_status = sr_drive_status,
.media_changed = sr_media_change,
.check_events = sr_check_events,
.tray_move = sr_tray_move,
.lock_door = sr_lock_door,
.select_speed = sr_select_speed,
@ -165,90 +166,96 @@ static void scsi_cd_put(struct scsi_cd *cd)
mutex_unlock(&sr_ref_mutex);
}
/* identical to scsi_test_unit_ready except that it doesn't
* eat the NOT_READY returns for removable media */
int sr_test_unit_ready(struct scsi_device *sdev, struct scsi_sense_hdr *sshdr)
static unsigned int sr_get_events(struct scsi_device *sdev)
{
int retries = MAX_RETRIES;
int the_result;
u8 cmd[] = {TEST_UNIT_READY, 0, 0, 0, 0, 0 };
u8 buf[8];
u8 cmd[] = { GET_EVENT_STATUS_NOTIFICATION,
1, /* polled */
0, 0, /* reserved */
1 << 4, /* notification class: media */
0, 0, /* reserved */
0, sizeof(buf), /* allocation length */
0, /* control */
};
struct event_header *eh = (void *)buf;
struct media_event_desc *med = (void *)(buf + 4);
struct scsi_sense_hdr sshdr;
int result;
/* issue TEST_UNIT_READY until the initial startup UNIT_ATTENTION
* conditions are gone, or a timeout happens
*/
do {
the_result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL,
0, sshdr, SR_TIMEOUT,
retries--, NULL);
if (scsi_sense_valid(sshdr) &&
sshdr->sense_key == UNIT_ATTENTION)
sdev->changed = 1;
result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buf, sizeof(buf),
&sshdr, SR_TIMEOUT, MAX_RETRIES, NULL);
if (scsi_sense_valid(&sshdr) && sshdr.sense_key == UNIT_ATTENTION)
return DISK_EVENT_MEDIA_CHANGE;
} while (retries > 0 &&
(!scsi_status_is_good(the_result) ||
(scsi_sense_valid(sshdr) &&
sshdr->sense_key == UNIT_ATTENTION)));
return the_result;
if (result || be16_to_cpu(eh->data_len) < sizeof(*med))
return 0;
if (eh->nea || eh->notification_class != 0x4)
return 0;
if (med->media_event_code == 1)
return DISK_EVENT_EJECT_REQUEST;
else if (med->media_event_code == 2)
return DISK_EVENT_MEDIA_CHANGE;
return 0;
}
/*
* This function checks to see if the media has been changed in the
* CDROM drive. It is possible that we have already sensed a change,
* or the drive may have sensed one and not yet reported it. We must
* be ready for either case. This function always reports the current
* value of the changed bit. If flag is 0, then the changed bit is reset.
* This function could be done as an ioctl, but we would need to have
* an inode for that to work, and we do not always have one.
* This function checks to see if the media has been changed or eject
* button has been pressed. It is possible that we have already
* sensed a change, or the drive may have sensed one and not yet
* reported it. The past events are accumulated in sdev->changed and
* returned together with the current state.
*/
static int sr_media_change(struct cdrom_device_info *cdi, int slot)
static unsigned int sr_check_events(struct cdrom_device_info *cdi,
unsigned int clearing, int slot)
{
struct scsi_cd *cd = cdi->handle;
int retval;
struct scsi_sense_hdr *sshdr;
bool last_present;
struct scsi_sense_hdr sshdr;
unsigned int events;
int ret;
if (CDSL_CURRENT != slot) {
/* no changer support */
return -EINVAL;
/* no changer support */
if (CDSL_CURRENT != slot)
return 0;
events = sr_get_events(cd->device);
/*
* GET_EVENT_STATUS_NOTIFICATION is enough unless MEDIA_CHANGE
* is being cleared. Note that there are devices which hang
* if asked to execute TUR repeatedly.
*/
if (!(clearing & DISK_EVENT_MEDIA_CHANGE))
goto skip_tur;
/* let's see whether the media is there with TUR */
last_present = cd->media_present;
ret = scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
/*
* Media is considered to be present if TUR succeeds or fails with
* sense data indicating something other than media-not-present
* (ASC 0x3a).
*/
cd->media_present = scsi_status_is_good(ret) ||
(scsi_sense_valid(&sshdr) && sshdr.asc != 0x3a);
if (last_present != cd->media_present)
events |= DISK_EVENT_MEDIA_CHANGE;
skip_tur:
if (cd->device->changed) {
events |= DISK_EVENT_MEDIA_CHANGE;
cd->device->changed = 0;
}
sshdr = kzalloc(sizeof(*sshdr), GFP_KERNEL);
retval = sr_test_unit_ready(cd->device, sshdr);
if (retval || (scsi_sense_valid(sshdr) &&
/* 0x3a is medium not present */
sshdr->asc == 0x3a)) {
/* Media not present or unable to test, unit probably not
* ready. This usually means there is no disc in the drive.
* Mark as changed, and we will figure it out later once
* the drive is available again.
*/
cd->device->changed = 1;
/* This will force a flush, if called from check_disk_change */
retval = 1;
goto out;
};
retval = cd->device->changed;
cd->device->changed = 0;
/* If the disk changed, the capacity will now be different,
* so we force a re-read of this information */
if (retval) {
/* check multisession offset etc */
sr_cd_check(cdi);
get_sectorsize(cd);
}
out:
/* Notify userspace, that media has changed. */
if (retval != cd->previous_state)
/* for backward compatibility */
if (events & DISK_EVENT_MEDIA_CHANGE)
sdev_evt_send_simple(cd->device, SDEV_EVT_MEDIA_CHANGE,
GFP_KERNEL);
cd->previous_state = retval;
kfree(sshdr);
return retval;
return events;
}
/*
* sr_done is the interrupt routine for the device driver.
*
@ -533,10 +540,25 @@ out:
return ret;
}
static int sr_block_media_changed(struct gendisk *disk)
static unsigned int sr_block_check_events(struct gendisk *disk,
unsigned int clearing)
{
struct scsi_cd *cd = scsi_cd(disk);
return cdrom_media_changed(&cd->cdi);
return cdrom_check_events(&cd->cdi, clearing);
}
static int sr_block_revalidate_disk(struct gendisk *disk)
{
struct scsi_cd *cd = scsi_cd(disk);
struct scsi_sense_hdr sshdr;
/* if the unit is not ready, nothing more to do */
if (scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr))
return 0;
sr_cd_check(&cd->cdi);
get_sectorsize(cd);
return 0;
}
static const struct block_device_operations sr_bdops =
@ -545,7 +567,8 @@ static const struct block_device_operations sr_bdops =
.open = sr_block_open,
.release = sr_block_release,
.ioctl = sr_block_ioctl,
.media_changed = sr_block_media_changed,
.check_events = sr_block_check_events,
.revalidate_disk = sr_block_revalidate_disk,
/*
* No compat_ioctl for now because sr_block_ioctl never
* seems to pass arbitary ioctls down to host drivers.
@ -618,6 +641,7 @@ static int sr_probe(struct device *dev)
sprintf(disk->disk_name, "sr%d", minor);
disk->fops = &sr_bdops;
disk->flags = GENHD_FL_CD;
disk->events = DISK_EVENT_MEDIA_CHANGE | DISK_EVENT_EJECT_REQUEST;
blk_queue_rq_timeout(sdev->request_queue, SR_TIMEOUT);
@ -627,7 +651,7 @@ static int sr_probe(struct device *dev)
cd->disk = disk;
cd->capacity = 0x1fffff;
cd->device->changed = 1; /* force recheck CD type */
cd->previous_state = 1;
cd->media_present = 1;
cd->use = 1;
cd->readcd_known = 0;
cd->readcd_cdda = 0;
@ -780,7 +804,7 @@ static void get_capabilities(struct scsi_cd *cd)
}
/* eat unit attentions */
sr_test_unit_ready(cd->device, &sshdr);
scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
/* ask for mode page 0x2a */
rc = scsi_mode_sense(cd->device, 0, 0x2a, buffer, 128,

3
drivers/scsi/sr.h
View File

@ -40,7 +40,7 @@ typedef struct scsi_cd {
unsigned xa_flag:1; /* CD has XA sectors ? */
unsigned readcd_known:1; /* drive supports READ_CD (0xbe) */
unsigned readcd_cdda:1; /* reading audio data using READ_CD */
unsigned previous_state:1; /* media has changed */
unsigned media_present:1; /* media is present */
struct cdrom_device_info cdi;
/* We hold gendisk and scsi_device references on probe and use
* the refs on this kref to decide when to release them */
@ -61,7 +61,6 @@ int sr_select_speed(struct cdrom_device_info *cdi, int speed);
int sr_audio_ioctl(struct cdrom_device_info *, unsigned int, void *);
int sr_is_xa(Scsi_CD *);
int sr_test_unit_ready(struct scsi_device *sdev, struct scsi_sense_hdr *sshdr);
/* sr_vendor.c */
void sr_vendor_init(Scsi_CD *);

2
drivers/scsi/sr_ioctl.c
View File

@ -307,7 +307,7 @@ int sr_drive_status(struct cdrom_device_info *cdi, int slot)
/* we have no changer support */
return -EINVAL;
}
if (0 == sr_test_unit_ready(cd->device, &sshdr))
if (!scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr))
return CDS_DISC_OK;
/* SK/ASC/ASCQ of 2/4/1 means "unit is becoming ready" */

41
fs/block_dev.c
View File

@ -948,10 +948,11 @@ int check_disk_change(struct block_device *bdev)
{
struct gendisk *disk = bdev->bd_disk;
const struct block_device_operations *bdops = disk->fops;
unsigned int events;
if (!bdops->media_changed)
return 0;
if (!bdops->media_changed(bdev->bd_disk))
events = disk_clear_events(disk, DISK_EVENT_MEDIA_CHANGE |
DISK_EVENT_EJECT_REQUEST);
if (!(events & DISK_EVENT_MEDIA_CHANGE))
return 0;
flush_disk(bdev);
@ -1158,9 +1159,10 @@ int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder)
if (whole) {
/* finish claiming */
mutex_lock(&bdev->bd_mutex);
spin_lock(&bdev_lock);
if (res == 0) {
if (!res) {
BUG_ON(!bd_may_claim(bdev, whole, holder));
/*
* Note that for a whole device bd_holders
@ -1180,6 +1182,20 @@ int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder)
wake_up_bit(&whole->bd_claiming, 0);
spin_unlock(&bdev_lock);
/*
* Block event polling for write claims. Any write
* holder makes the write_holder state stick until all
* are released. This is good enough and tracking
* individual writeable reference is too fragile given
* the way @mode is used in blkdev_get/put().
*/
if (!res && (mode & FMODE_WRITE) && !bdev->bd_write_holder) {
bdev->bd_write_holder = true;
disk_block_events(bdev->bd_disk);
}
mutex_unlock(&bdev->bd_mutex);
bdput(whole);
}
@ -1353,12 +1369,23 @@ int blkdev_put(struct block_device *bdev, fmode_t mode)
spin_unlock(&bdev_lock);
/* if this was the last claim, holder link should go too */
if (bdev_free)
/*
* If this was the last claim, remove holder link and
* unblock evpoll if it was a write holder.
*/
if (bdev_free) {
bd_unlink_disk_holder(bdev);
if (bdev->bd_write_holder) {
disk_unblock_events(bdev->bd_disk);
bdev->bd_write_holder = false;
} else
disk_check_events(bdev->bd_disk);
}
mutex_unlock(&bdev->bd_mutex);
}
} else
disk_check_events(bdev->bd_disk);
return __blkdev_put(bdev, mode, 0);
}
EXPORT_SYMBOL(blkdev_put);

89
fs/partitions/check.c
View File

@ -522,65 +522,6 @@ out_put:
return ERR_PTR(err);
}
/* Not exported, helper to add_disk(). */
void register_disk(struct gendisk *disk)
{
struct device *ddev = disk_to_dev(disk);
struct block_device *bdev;
struct disk_part_iter piter;
struct hd_struct *part;
int err;
ddev->parent = disk->driverfs_dev;
dev_set_name(ddev, disk->disk_name);
/* delay uevents, until we scanned partition table */
dev_set_uevent_suppress(ddev, 1);
if (device_add(ddev))
return;
if (!sysfs_deprecated) {
err = sysfs_create_link(block_depr, &ddev->kobj,
kobject_name(&ddev->kobj));
if (err) {
device_del(ddev);
return;
}
}
disk->part0.holder_dir = kobject_create_and_add("holders", &ddev->kobj);
disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj);
/* No minors to use for partitions */
if (!disk_partitionable(disk))
goto exit;
/* No such device (e.g., media were just removed) */
if (!get_capacity(disk))
goto exit;
bdev = bdget_disk(disk, 0);
if (!bdev)
goto exit;
bdev->bd_invalidated = 1;
err = blkdev_get(bdev, FMODE_READ, NULL);
if (err < 0)
goto exit;
blkdev_put(bdev, FMODE_READ);
exit:
/* announce disk after possible partitions are created */
dev_set_uevent_suppress(ddev, 0);
kobject_uevent(&ddev->kobj, KOBJ_ADD);
/* announce possible partitions */
disk_part_iter_init(&piter, disk, 0);
while ((part = disk_part_iter_next(&piter)))
kobject_uevent(&part_to_dev(part)->kobj, KOBJ_ADD);
disk_part_iter_exit(&piter);
}
static bool disk_unlock_native_capacity(struct gendisk *disk)
{
const struct block_device_operations *bdops = disk->fops;
@ -743,33 +684,3 @@ fail:
}
EXPORT_SYMBOL(read_dev_sector);
void del_gendisk(struct gendisk *disk)
{
struct disk_part_iter piter;
struct hd_struct *part;
/* invalidate stuff */
disk_part_iter_init(&piter, disk,
DISK_PITER_INCL_EMPTY | DISK_PITER_REVERSE);
while ((part = disk_part_iter_next(&piter))) {
invalidate_partition(disk, part->partno);
delete_partition(disk, part->partno);
}
disk_part_iter_exit(&piter);
invalidate_partition(disk, 0);
blk_free_devt(disk_to_dev(disk)->devt);
set_capacity(disk, 0);
disk->flags &= ~GENHD_FL_UP;
unlink_gendisk(disk);
part_stat_set_all(&disk->part0, 0);
disk->part0.stamp = 0;
kobject_put(disk->part0.holder_dir);
kobject_put(disk->slave_dir);
disk->driverfs_dev = NULL;
if (!sysfs_deprecated)
sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk)));
device_del(disk_to_dev(disk));
}

4
include/linux/blkdev.h
View File

@ -644,7 +644,6 @@ static inline void rq_flush_dcache_pages(struct request *rq)
extern int blk_register_queue(struct gendisk *disk);
extern void blk_unregister_queue(struct gendisk *disk);
extern void register_disk(struct gendisk *dev);
extern void generic_make_request(struct bio *bio);
extern void blk_rq_init(struct request_queue *q, struct request *rq);
extern void blk_put_request(struct request *);
@ -1253,6 +1252,9 @@ struct block_device_operations {
int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long);
int (*direct_access) (struct block_device *, sector_t,
void **, unsigned long *);
unsigned int (*check_events) (struct gendisk *disk,
unsigned int clearing);
/* ->media_changed() is DEPRECATED, use ->check_events() instead */
int (*media_changed) (struct gendisk *);
void (*unlock_native_capacity) (struct gendisk *);
int (*revalidate_disk) (struct gendisk *);

6
include/linux/cdrom.h
View File

@ -946,6 +946,8 @@ struct cdrom_device_info {
/* device-related storage */
unsigned int options : 30; /* options flags */
unsigned mc_flags : 2; /* media change buffer flags */
unsigned int vfs_events; /* cached events for vfs path */
unsigned int ioctl_events; /* cached events for ioctl path */
int use_count; /* number of times device opened */
char name[20]; /* name of the device type */
/* per-device flags */
@ -965,6 +967,8 @@ struct cdrom_device_ops {
int (*open) (struct cdrom_device_info *, int);
void (*release) (struct cdrom_device_info *);
int (*drive_status) (struct cdrom_device_info *, int);
unsigned int (*check_events) (struct cdrom_device_info *cdi,
unsigned int clearing, int slot);
int (*media_changed) (struct cdrom_device_info *, int);
int (*tray_move) (struct cdrom_device_info *, int);
int (*lock_door) (struct cdrom_device_info *, int);
@ -993,6 +997,8 @@ extern int cdrom_open(struct cdrom_device_info *cdi, struct block_device *bdev,
extern void cdrom_release(struct cdrom_device_info *cdi, fmode_t mode);
extern int cdrom_ioctl(struct cdrom_device_info *cdi, struct block_device *bdev,
fmode_t mode, unsigned int cmd, unsigned long arg);
extern unsigned int cdrom_check_events(struct cdrom_device_info *cdi,
unsigned int clearing);
extern int cdrom_media_changed(struct cdrom_device_info *);
extern int register_cdrom(struct cdrom_device_info *cdi);

1
include/linux/fs.h
View File

@ -662,6 +662,7 @@ struct block_device {
void * bd_claiming;
void * bd_holder;
int bd_holders;
bool bd_write_holder;
#ifdef CONFIG_SYSFS
struct gendisk * bd_holder_disk; /* for sysfs slave linkng */
#endif

20
include/linux/genhd.h
View File

@ -128,6 +128,11 @@ struct hd_struct {
#define GENHD_FL_EXT_DEVT 64 /* allow extended devt */
#define GENHD_FL_NATIVE_CAPACITY 128
enum {
DISK_EVENT_MEDIA_CHANGE = 1 << 0, /* media changed */
DISK_EVENT_EJECT_REQUEST = 1 << 1, /* eject requested */
};
#define BLK_SCSI_MAX_CMDS (256)
#define BLK_SCSI_CMD_PER_LONG (BLK_SCSI_MAX_CMDS / (sizeof(long) * 8))
@ -144,6 +149,8 @@ struct disk_part_tbl {
struct hd_struct __rcu *part[];
};
struct disk_events;
struct gendisk {
/* major, first_minor and minors are input parameters only,
* don't use directly. Use disk_devt() and disk_max_parts().
@ -155,6 +162,10 @@ struct gendisk {
char disk_name[DISK_NAME_LEN]; /* name of major driver */
char *(*devnode)(struct gendisk *gd, mode_t *mode);
unsigned int events; /* supported events */
unsigned int async_events; /* async events, subset of all */
/* Array of pointers to partitions indexed by partno.
* Protected with matching bdev lock but stat and other
* non-critical accesses use RCU. Always access through
@ -172,9 +183,8 @@ struct gendisk {
struct kobject *slave_dir;
struct timer_rand_state *random;
atomic_t sync_io; /* RAID */
struct work_struct async_notify;
struct disk_events *ev;
#ifdef CONFIG_BLK_DEV_INTEGRITY
struct blk_integrity *integrity;
#endif
@ -396,7 +406,6 @@ extern void part_round_stats(int cpu, struct hd_struct *part);
/* block/genhd.c */
extern void add_disk(struct gendisk *disk);
extern void del_gendisk(struct gendisk *gp);
extern void unlink_gendisk(struct gendisk *gp);
extern struct gendisk *get_gendisk(dev_t dev, int *partno);
extern struct block_device *bdget_disk(struct gendisk *disk, int partno);
@ -408,6 +417,11 @@ static inline int get_disk_ro(struct gendisk *disk)
return disk->part0.policy;
}
extern void disk_block_events(struct gendisk *disk);
extern void disk_unblock_events(struct gendisk *disk);
extern void disk_check_events(struct gendisk *disk);
extern unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask);
/* drivers/char/random.c */
extern void add_disk_randomness(struct gendisk *disk);
extern void rand_initialize_disk(struct gendisk *disk);

1
include/scsi/scsi.h
View File

@ -104,6 +104,7 @@ struct scsi_cmnd;
#define UNMAP 0x42
#define READ_TOC 0x43
#define READ_HEADER 0x44
#define GET_EVENT_STATUS_NOTIFICATION 0x4a
#define LOG_SELECT 0x4c
#define LOG_SENSE 0x4d
#define XDWRITEREAD_10 0x53