Re: [patch 2/3] libata: expose AN support to user space via sysfs
Tejun Heo wrote: Jeff Garzik wrote: AN is a generic concept that I feel will propagate elsewhere. I think SCSI already has it or am I imagining things again? :-) Though perhaps it should be in a 'capability_flags' file rather than a 'media_change_event' file. IMHO, if it's genhd.capability_flags then the flag should be MEDIA_CHANGE_NOTIFY not ASYNC_NOTIFICATION because AN itself doesn't imply any specific event. It's just a notification mechanism, for ATAPI devices, it means media change, for PMP it has a different meaning, so I think we need to export the processed meaning not the specific mechanism to userland. Agreed, sounds good. Jeff - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [patch 2/3] libata: expose AN support to user space via sysfs
Tejun Heo wrote: Jeff Garzik wrote: AN is a generic concept that I feel will propagate elsewhere. I think SCSI already has it or am I imagining things again? :-) Though perhaps it should be in a 'capability_flags' file rather than a 'media_change_event' file. IMHO, if it's genhd.capability_flags then the flag should be MEDIA_CHANGE_NOTIFY not ASYNC_NOTIFICATION because AN itself doesn't imply any specific event. It's just a notification mechanism, for ATAPI devices, it means media change, for PMP it has a different meaning, so I think we need to export the processed meaning not the specific mechanism to userland. Agreed, sounds good. Jeff - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [patch 2/3] libata: expose AN support to user space via sysfs
Jeff Garzik wrote: AN is a generic concept that I feel will propagate elsewhere. I think SCSI already has it or am I imagining things again? :-) Though perhaps it should be in a 'capability_flags' file rather than a 'media_change_event' file. IMHO, if it's genhd.capability_flags then the flag should be MEDIA_CHANGE_NOTIFY not ASYNC_NOTIFICATION because AN itself doesn't imply any specific event. It's just a notification mechanism, for ATAPI devices, it means media change, for PMP it has a different meaning, so I think we need to export the processed meaning not the specific mechanism to userland. Thanks. -- tejun - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [patch 2/3] libata: expose AN support to user space via sysfs
Tejun Heo wrote: Jeff Garzik wrote: Kristen Carlson Accardi wrote: Allow user space to determine if an ATAPI device supports async notification (AN) of media changes. This is done by adding a new sysfs file "async_notification" to genhd. If the file reads 1, then the device supports async notification. If the file reads 0, it does not. A flag is set in the generic disk to indicate whether or not AN is supported. This flag is set by the SCSI subsystem when it registers with add_disk. The SCSI system gets information from libata on whether the device supports AN during dev_configure. Signed-off-by: Kristen Carlson Accardi <[EMAIL PROTECTED]> 3) I would make the contents of 'media_change_events' be a list of flags, rather than a boolean. Thus, when AN is present, media_change_events would return "AN\n". It would return "\n" (no flags) when AN is absent. This permits future expansion of this capabilities reporting variable. I'm not sure about this. AN is kind of specific term for ATA while media change event is generic. So, I think the original approach is okay. No matter how the actual thing is implemented, it's the same media change event and as long as event delivery interface is the same, upper layer shouldn't care about how it's done. AN is a generic concept that I feel will propagate elsewhere. Though perhaps it should be in a 'capability_flags' file rather than a 'media_change_event' file. Jeff - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [patch 2/3] libata: expose AN support to user space via sysfs
Jeff Garzik wrote: Kristen Carlson Accardi wrote: Allow user space to determine if an ATAPI device supports async notification (AN) of media changes. This is done by adding a new sysfs file "async_notification" to genhd. If the file reads 1, then the device supports async notification. If the file reads 0, it does not. A flag is set in the generic disk to indicate whether or not AN is supported. This flag is set by the SCSI subsystem when it registers with add_disk. The SCSI system gets information from libata on whether the device supports AN during dev_configure. Signed-off-by: Kristen Carlson Accardi <[EMAIL PROTECTED]> 3) I would make the contents of 'media_change_events' be a list of flags, rather than a boolean. Thus, when AN is present, media_change_events would return "AN\n". It would return "\n" (no flags) when AN is absent. This permits future expansion of this capabilities reporting variable. I'm not sure about this. AN is kind of specific term for ATA while media change event is generic. So, I think the original approach is okay. No matter how the actual thing is implemented, it's the same media change event and as long as event delivery interface is the same, upper layer shouldn't care about how it's done. Thanks. -- tejun - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [patch 2/3] libata: expose AN support to user space via sysfs
Kristen Carlson Accardi wrote: Allow user space to determine if an ATAPI device supports async notification (AN) of media changes. This is done by adding a new sysfs file "async_notification" to genhd. If the file reads 1, then the device supports async notification. If the file reads 0, it does not. A flag is set in the generic disk to indicate whether or not AN is supported. This flag is set by the SCSI subsystem when it registers with add_disk. The SCSI system gets information from libata on whether the device supports AN during dev_configure. I'm not sure whether this should be in generic block layer or in libata proper. libata sysfs hierarchy isn't there yet but is scheduled to be added soon. Async notification of media change is generic event for any block device with removable media, so I guess it can belong to generic layer. BTW, I think you also need to forward the flag in sd - disk device can be removable too. And please cc linux-scsi@vger.kernel.org to get SCSI part reviewed. Thanks. -- tejun - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [patch 2/3] libata: expose AN support to user space via sysfs
Kristen Carlson Accardi wrote:
Allow user space to determine if an ATAPI device supports
async notification (AN) of media changes. This is done by
adding a new sysfs file "async_notification" to genhd.
If the file reads 1, then the device supports async
notification. If the file reads 0, it does not.
A flag is set in the generic disk to indicate whether
or not AN is supported. This flag is set by the SCSI
subsystem when it registers with add_disk. The SCSI
system gets information from libata on whether the
device supports AN during dev_configure.
Signed-off-by: Kristen Carlson Accardi <[EMAIL PROTECTED]>
Index: 2.6-mm/block/genhd.c
===
--- 2.6-mm.orig/block/genhd.c
+++ 2.6-mm/block/genhd.c
@@ -372,6 +372,11 @@ static ssize_t disk_size_read(struct gen
{
return sprintf(page, "%llu\n", (unsigned long long)get_capacity(disk));
}
+static ssize_t disk_AN_read(struct gendisk * disk, char *page)
+{
+ return sprintf(page, "%d\n",
+ (disk->flags & GENHD_FL_ASYNC_NOTIFICATION ? 1 : 0));
+}
static ssize_t disk_stats_read(struct gendisk * disk, char *page)
{
@@ -419,6 +424,10 @@ static struct disk_attribute disk_attr_s
.attr = {.name = "stat", .mode = S_IRUGO },
.show = disk_stats_read
};
+static struct disk_attribute disk_attr_AN = {
+ .attr = {.name = "media_change_events", .mode = S_IRUGO },
+ .show = disk_AN_read
+};
#ifdef CONFIG_FAIL_MAKE_REQUEST
@@ -455,6 +464,7 @@ static struct attribute * default_attrs[
_attr_removable.attr,
_attr_size.attr,
_attr_stat.attr,
+ _attr_AN.attr,
#ifdef CONFIG_FAIL_MAKE_REQUEST
_attr_fail.attr,
#endif
Index: 2.6-mm/include/linux/genhd.h
===
--- 2.6-mm.orig/include/linux/genhd.h
+++ 2.6-mm/include/linux/genhd.h
@@ -94,6 +94,7 @@ struct hd_struct {
#define GENHD_FL_REMOVABLE 1
#define GENHD_FL_DRIVERFS 2
+#define GENHD_FL_ASYNC_NOTIFICATION4
#define GENHD_FL_CD8
#define GENHD_FL_UP16
#define GENHD_FL_SUPPRESS_PARTITION_INFO 32
Index: 2.6-mm/include/scsi/scsi_device.h
===
--- 2.6-mm.orig/include/scsi/scsi_device.h
+++ 2.6-mm/include/scsi/scsi_device.h
@@ -126,7 +126,7 @@ struct scsi_device {
unsigned fix_capacity:1;/* READ_CAPACITY is too high by 1 */
unsigned guess_capacity:1; /* READ_CAPACITY might be too high by 1
*/
unsigned retry_hwerror:1; /* Retry HARDWARE_ERROR */
-
+ unsigned async_notification:1; /* device supports async notification */
unsigned int device_blocked;/* Device returned QUEUE_FULL. */
unsigned int max_device_blocked; /* what device_blocked counts down from */
Index: 2.6-mm/drivers/ata/libata-scsi.c
===
--- 2.6-mm.orig/drivers/ata/libata-scsi.c
+++ 2.6-mm/drivers/ata/libata-scsi.c
@@ -899,6 +899,9 @@ static void ata_scsi_dev_config(struct s
blk_queue_max_hw_segments(q, q->max_hw_segments - 1);
}
+ if (dev->flags & ATA_DFLAG_AN)
+ sdev->async_notification = 1;
+
if (dev->flags & ATA_DFLAG_NCQ) {
int depth;
Index: 2.6-mm/drivers/scsi/sr.c
===
--- 2.6-mm.orig/drivers/scsi/sr.c
+++ 2.6-mm/drivers/scsi/sr.c
@@ -603,6 +603,8 @@ static int sr_probe(struct device *dev)
dev_set_drvdata(dev, cd);
disk->flags |= GENHD_FL_REMOVABLE;
+ if (sdev->async_notification)
+ disk->flags |= GENHD_FL_ASYNC_NOTIFICATION;
add_disk(disk);
(added linux-scsi to CC)
Comments:
1) From a procedural standpoint, you'll want to separate this patch into
three patches: generic block layer stuff, SCSI stuff, and libata stuff.
2) I don't claim to be a sysfs expert, but this seems like a reasonable
approach for reporting async-notification capabilities
3) I would make the contents of 'media_change_events' be a list of
flags, rather than a boolean. Thus, when AN is present,
media_change_events would return "AN\n". It would return "\n" (no
flags) when AN is absent. This permits future expansion of this
capabilities reporting variable.
4) Figure out some place to document 'media_change_events', in
Documentation/*
5) I think the method of delivery probably needs discussing, and some
work. Presumably the normal hotplug paths should be traversed for this
sort of thing.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[patch 2/3] libata: expose AN support to user space via sysfs
Allow user space to determine if an ATAPI device supports
async notification (AN) of media changes. This is done by
adding a new sysfs file "async_notification" to genhd.
If the file reads 1, then the device supports async
notification. If the file reads 0, it does not.
A flag is set in the generic disk to indicate whether
or not AN is supported. This flag is set by the SCSI
subsystem when it registers with add_disk. The SCSI
system gets information from libata on whether the
device supports AN during dev_configure.
Signed-off-by: Kristen Carlson Accardi <[EMAIL PROTECTED]>
Index: 2.6-mm/block/genhd.c
===
--- 2.6-mm.orig/block/genhd.c
+++ 2.6-mm/block/genhd.c
@@ -372,6 +372,11 @@ static ssize_t disk_size_read(struct gen
{
return sprintf(page, "%llu\n", (unsigned long long)get_capacity(disk));
}
+static ssize_t disk_AN_read(struct gendisk * disk, char *page)
+{
+ return sprintf(page, "%d\n",
+ (disk->flags & GENHD_FL_ASYNC_NOTIFICATION ? 1 : 0));
+}
static ssize_t disk_stats_read(struct gendisk * disk, char *page)
{
@@ -419,6 +424,10 @@ static struct disk_attribute disk_attr_s
.attr = {.name = "stat", .mode = S_IRUGO },
.show = disk_stats_read
};
+static struct disk_attribute disk_attr_AN = {
+ .attr = {.name = "media_change_events", .mode = S_IRUGO },
+ .show = disk_AN_read
+};
#ifdef CONFIG_FAIL_MAKE_REQUEST
@@ -455,6 +464,7 @@ static struct attribute * default_attrs[
_attr_removable.attr,
_attr_size.attr,
_attr_stat.attr,
+ _attr_AN.attr,
#ifdef CONFIG_FAIL_MAKE_REQUEST
_attr_fail.attr,
#endif
Index: 2.6-mm/include/linux/genhd.h
===
--- 2.6-mm.orig/include/linux/genhd.h
+++ 2.6-mm/include/linux/genhd.h
@@ -94,6 +94,7 @@ struct hd_struct {
#define GENHD_FL_REMOVABLE 1
#define GENHD_FL_DRIVERFS 2
+#define GENHD_FL_ASYNC_NOTIFICATION4
#define GENHD_FL_CD8
#define GENHD_FL_UP16
#define GENHD_FL_SUPPRESS_PARTITION_INFO 32
Index: 2.6-mm/include/scsi/scsi_device.h
===
--- 2.6-mm.orig/include/scsi/scsi_device.h
+++ 2.6-mm/include/scsi/scsi_device.h
@@ -126,7 +126,7 @@ struct scsi_device {
unsigned fix_capacity:1;/* READ_CAPACITY is too high by 1 */
unsigned guess_capacity:1; /* READ_CAPACITY might be too high by 1
*/
unsigned retry_hwerror:1; /* Retry HARDWARE_ERROR */
-
+ unsigned async_notification:1; /* device supports async notification */
unsigned int device_blocked;/* Device returned QUEUE_FULL. */
unsigned int max_device_blocked; /* what device_blocked counts down
from */
Index: 2.6-mm/drivers/ata/libata-scsi.c
===
--- 2.6-mm.orig/drivers/ata/libata-scsi.c
+++ 2.6-mm/drivers/ata/libata-scsi.c
@@ -899,6 +899,9 @@ static void ata_scsi_dev_config(struct s
blk_queue_max_hw_segments(q, q->max_hw_segments - 1);
}
+ if (dev->flags & ATA_DFLAG_AN)
+ sdev->async_notification = 1;
+
if (dev->flags & ATA_DFLAG_NCQ) {
int depth;
Index: 2.6-mm/drivers/scsi/sr.c
===
--- 2.6-mm.orig/drivers/scsi/sr.c
+++ 2.6-mm/drivers/scsi/sr.c
@@ -603,6 +603,8 @@ static int sr_probe(struct device *dev)
dev_set_drvdata(dev, cd);
disk->flags |= GENHD_FL_REMOVABLE;
+ if (sdev->async_notification)
+ disk->flags |= GENHD_FL_ASYNC_NOTIFICATION;
add_disk(disk);
sdev_printk(KERN_DEBUG, sdev,
--
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[patch 2/3] libata: expose AN support to user space via sysfs
Allow user space to determine if an ATAPI device supports
async notification (AN) of media changes. This is done by
adding a new sysfs file async_notification to genhd.
If the file reads 1, then the device supports async
notification. If the file reads 0, it does not.
A flag is set in the generic disk to indicate whether
or not AN is supported. This flag is set by the SCSI
subsystem when it registers with add_disk. The SCSI
system gets information from libata on whether the
device supports AN during dev_configure.
Signed-off-by: Kristen Carlson Accardi [EMAIL PROTECTED]
Index: 2.6-mm/block/genhd.c
===
--- 2.6-mm.orig/block/genhd.c
+++ 2.6-mm/block/genhd.c
@@ -372,6 +372,11 @@ static ssize_t disk_size_read(struct gen
{
return sprintf(page, %llu\n, (unsigned long long)get_capacity(disk));
}
+static ssize_t disk_AN_read(struct gendisk * disk, char *page)
+{
+ return sprintf(page, %d\n,
+ (disk-flags GENHD_FL_ASYNC_NOTIFICATION ? 1 : 0));
+}
static ssize_t disk_stats_read(struct gendisk * disk, char *page)
{
@@ -419,6 +424,10 @@ static struct disk_attribute disk_attr_s
.attr = {.name = stat, .mode = S_IRUGO },
.show = disk_stats_read
};
+static struct disk_attribute disk_attr_AN = {
+ .attr = {.name = media_change_events, .mode = S_IRUGO },
+ .show = disk_AN_read
+};
#ifdef CONFIG_FAIL_MAKE_REQUEST
@@ -455,6 +464,7 @@ static struct attribute * default_attrs[
disk_attr_removable.attr,
disk_attr_size.attr,
disk_attr_stat.attr,
+ disk_attr_AN.attr,
#ifdef CONFIG_FAIL_MAKE_REQUEST
disk_attr_fail.attr,
#endif
Index: 2.6-mm/include/linux/genhd.h
===
--- 2.6-mm.orig/include/linux/genhd.h
+++ 2.6-mm/include/linux/genhd.h
@@ -94,6 +94,7 @@ struct hd_struct {
#define GENHD_FL_REMOVABLE 1
#define GENHD_FL_DRIVERFS 2
+#define GENHD_FL_ASYNC_NOTIFICATION4
#define GENHD_FL_CD8
#define GENHD_FL_UP16
#define GENHD_FL_SUPPRESS_PARTITION_INFO 32
Index: 2.6-mm/include/scsi/scsi_device.h
===
--- 2.6-mm.orig/include/scsi/scsi_device.h
+++ 2.6-mm/include/scsi/scsi_device.h
@@ -126,7 +126,7 @@ struct scsi_device {
unsigned fix_capacity:1;/* READ_CAPACITY is too high by 1 */
unsigned guess_capacity:1; /* READ_CAPACITY might be too high by 1
*/
unsigned retry_hwerror:1; /* Retry HARDWARE_ERROR */
-
+ unsigned async_notification:1; /* device supports async notification */
unsigned int device_blocked;/* Device returned QUEUE_FULL. */
unsigned int max_device_blocked; /* what device_blocked counts down
from */
Index: 2.6-mm/drivers/ata/libata-scsi.c
===
--- 2.6-mm.orig/drivers/ata/libata-scsi.c
+++ 2.6-mm/drivers/ata/libata-scsi.c
@@ -899,6 +899,9 @@ static void ata_scsi_dev_config(struct s
blk_queue_max_hw_segments(q, q-max_hw_segments - 1);
}
+ if (dev-flags ATA_DFLAG_AN)
+ sdev-async_notification = 1;
+
if (dev-flags ATA_DFLAG_NCQ) {
int depth;
Index: 2.6-mm/drivers/scsi/sr.c
===
--- 2.6-mm.orig/drivers/scsi/sr.c
+++ 2.6-mm/drivers/scsi/sr.c
@@ -603,6 +603,8 @@ static int sr_probe(struct device *dev)
dev_set_drvdata(dev, cd);
disk-flags |= GENHD_FL_REMOVABLE;
+ if (sdev-async_notification)
+ disk-flags |= GENHD_FL_ASYNC_NOTIFICATION;
add_disk(disk);
sdev_printk(KERN_DEBUG, sdev,
--
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: [patch 2/3] libata: expose AN support to user space via sysfs
Kristen Carlson Accardi wrote:
Allow user space to determine if an ATAPI device supports
async notification (AN) of media changes. This is done by
adding a new sysfs file async_notification to genhd.
If the file reads 1, then the device supports async
notification. If the file reads 0, it does not.
A flag is set in the generic disk to indicate whether
or not AN is supported. This flag is set by the SCSI
subsystem when it registers with add_disk. The SCSI
system gets information from libata on whether the
device supports AN during dev_configure.
Signed-off-by: Kristen Carlson Accardi [EMAIL PROTECTED]
Index: 2.6-mm/block/genhd.c
===
--- 2.6-mm.orig/block/genhd.c
+++ 2.6-mm/block/genhd.c
@@ -372,6 +372,11 @@ static ssize_t disk_size_read(struct gen
{
return sprintf(page, %llu\n, (unsigned long long)get_capacity(disk));
}
+static ssize_t disk_AN_read(struct gendisk * disk, char *page)
+{
+ return sprintf(page, %d\n,
+ (disk-flags GENHD_FL_ASYNC_NOTIFICATION ? 1 : 0));
+}
static ssize_t disk_stats_read(struct gendisk * disk, char *page)
{
@@ -419,6 +424,10 @@ static struct disk_attribute disk_attr_s
.attr = {.name = stat, .mode = S_IRUGO },
.show = disk_stats_read
};
+static struct disk_attribute disk_attr_AN = {
+ .attr = {.name = media_change_events, .mode = S_IRUGO },
+ .show = disk_AN_read
+};
#ifdef CONFIG_FAIL_MAKE_REQUEST
@@ -455,6 +464,7 @@ static struct attribute * default_attrs[
disk_attr_removable.attr,
disk_attr_size.attr,
disk_attr_stat.attr,
+ disk_attr_AN.attr,
#ifdef CONFIG_FAIL_MAKE_REQUEST
disk_attr_fail.attr,
#endif
Index: 2.6-mm/include/linux/genhd.h
===
--- 2.6-mm.orig/include/linux/genhd.h
+++ 2.6-mm/include/linux/genhd.h
@@ -94,6 +94,7 @@ struct hd_struct {
#define GENHD_FL_REMOVABLE 1
#define GENHD_FL_DRIVERFS 2
+#define GENHD_FL_ASYNC_NOTIFICATION4
#define GENHD_FL_CD8
#define GENHD_FL_UP16
#define GENHD_FL_SUPPRESS_PARTITION_INFO 32
Index: 2.6-mm/include/scsi/scsi_device.h
===
--- 2.6-mm.orig/include/scsi/scsi_device.h
+++ 2.6-mm/include/scsi/scsi_device.h
@@ -126,7 +126,7 @@ struct scsi_device {
unsigned fix_capacity:1;/* READ_CAPACITY is too high by 1 */
unsigned guess_capacity:1; /* READ_CAPACITY might be too high by 1
*/
unsigned retry_hwerror:1; /* Retry HARDWARE_ERROR */
-
+ unsigned async_notification:1; /* device supports async notification */
unsigned int device_blocked;/* Device returned QUEUE_FULL. */
unsigned int max_device_blocked; /* what device_blocked counts down from */
Index: 2.6-mm/drivers/ata/libata-scsi.c
===
--- 2.6-mm.orig/drivers/ata/libata-scsi.c
+++ 2.6-mm/drivers/ata/libata-scsi.c
@@ -899,6 +899,9 @@ static void ata_scsi_dev_config(struct s
blk_queue_max_hw_segments(q, q-max_hw_segments - 1);
}
+ if (dev-flags ATA_DFLAG_AN)
+ sdev-async_notification = 1;
+
if (dev-flags ATA_DFLAG_NCQ) {
int depth;
Index: 2.6-mm/drivers/scsi/sr.c
===
--- 2.6-mm.orig/drivers/scsi/sr.c
+++ 2.6-mm/drivers/scsi/sr.c
@@ -603,6 +603,8 @@ static int sr_probe(struct device *dev)
dev_set_drvdata(dev, cd);
disk-flags |= GENHD_FL_REMOVABLE;
+ if (sdev-async_notification)
+ disk-flags |= GENHD_FL_ASYNC_NOTIFICATION;
add_disk(disk);
(added linux-scsi to CC)
Comments:
1) From a procedural standpoint, you'll want to separate this patch into
three patches: generic block layer stuff, SCSI stuff, and libata stuff.
2) I don't claim to be a sysfs expert, but this seems like a reasonable
approach for reporting async-notification capabilities
3) I would make the contents of 'media_change_events' be a list of
flags, rather than a boolean. Thus, when AN is present,
media_change_events would return AN\n. It would return \n (no
flags) when AN is absent. This permits future expansion of this
capabilities reporting variable.
4) Figure out some place to document 'media_change_events', in
Documentation/*
5) I think the method of delivery probably needs discussing, and some
work. Presumably the normal hotplug paths should be traversed for this
sort of thing.
-
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: [patch 2/3] libata: expose AN support to user space via sysfs
Kristen Carlson Accardi wrote: Allow user space to determine if an ATAPI device supports async notification (AN) of media changes. This is done by adding a new sysfs file async_notification to genhd. If the file reads 1, then the device supports async notification. If the file reads 0, it does not. A flag is set in the generic disk to indicate whether or not AN is supported. This flag is set by the SCSI subsystem when it registers with add_disk. The SCSI system gets information from libata on whether the device supports AN during dev_configure. I'm not sure whether this should be in generic block layer or in libata proper. libata sysfs hierarchy isn't there yet but is scheduled to be added soon. Async notification of media change is generic event for any block device with removable media, so I guess it can belong to generic layer. BTW, I think you also need to forward the flag in sd - disk device can be removable too. And please cc linux-scsi@vger.kernel.org to get SCSI part reviewed. Thanks. -- tejun - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [patch 2/3] libata: expose AN support to user space via sysfs
Jeff Garzik wrote: Kristen Carlson Accardi wrote: Allow user space to determine if an ATAPI device supports async notification (AN) of media changes. This is done by adding a new sysfs file async_notification to genhd. If the file reads 1, then the device supports async notification. If the file reads 0, it does not. A flag is set in the generic disk to indicate whether or not AN is supported. This flag is set by the SCSI subsystem when it registers with add_disk. The SCSI system gets information from libata on whether the device supports AN during dev_configure. Signed-off-by: Kristen Carlson Accardi [EMAIL PROTECTED] 3) I would make the contents of 'media_change_events' be a list of flags, rather than a boolean. Thus, when AN is present, media_change_events would return AN\n. It would return \n (no flags) when AN is absent. This permits future expansion of this capabilities reporting variable. I'm not sure about this. AN is kind of specific term for ATA while media change event is generic. So, I think the original approach is okay. No matter how the actual thing is implemented, it's the same media change event and as long as event delivery interface is the same, upper layer shouldn't care about how it's done. Thanks. -- tejun - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [patch 2/3] libata: expose AN support to user space via sysfs
Tejun Heo wrote: Jeff Garzik wrote: Kristen Carlson Accardi wrote: Allow user space to determine if an ATAPI device supports async notification (AN) of media changes. This is done by adding a new sysfs file async_notification to genhd. If the file reads 1, then the device supports async notification. If the file reads 0, it does not. A flag is set in the generic disk to indicate whether or not AN is supported. This flag is set by the SCSI subsystem when it registers with add_disk. The SCSI system gets information from libata on whether the device supports AN during dev_configure. Signed-off-by: Kristen Carlson Accardi [EMAIL PROTECTED] 3) I would make the contents of 'media_change_events' be a list of flags, rather than a boolean. Thus, when AN is present, media_change_events would return AN\n. It would return \n (no flags) when AN is absent. This permits future expansion of this capabilities reporting variable. I'm not sure about this. AN is kind of specific term for ATA while media change event is generic. So, I think the original approach is okay. No matter how the actual thing is implemented, it's the same media change event and as long as event delivery interface is the same, upper layer shouldn't care about how it's done. AN is a generic concept that I feel will propagate elsewhere. Though perhaps it should be in a 'capability_flags' file rather than a 'media_change_event' file. Jeff - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [patch 2/3] libata: expose AN support to user space via sysfs
Jeff Garzik wrote: AN is a generic concept that I feel will propagate elsewhere. I think SCSI already has it or am I imagining things again? :-) Though perhaps it should be in a 'capability_flags' file rather than a 'media_change_event' file. IMHO, if it's genhd.capability_flags then the flag should be MEDIA_CHANGE_NOTIFY not ASYNC_NOTIFICATION because AN itself doesn't imply any specific event. It's just a notification mechanism, for ATAPI devices, it means media change, for PMP it has a different meaning, so I think we need to export the processed meaning not the specific mechanism to userland. Thanks. -- tejun - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
