Re: [PATCH 5/5] block: genhd: add an interface to set disk's poll interval
From: Betty Dall <hidden>
Date: 2012-07-23 18:43:42
Also in:
linux-scsi, lkml
Hi Aaron, On Mon, 2012-07-23 at 14:49 +0800, Aaron Lu wrote:
Set the ODD's in kernel poll interval to 2s for the user in case the user is using an old distro on which udev will not set the system wide block parameter events_dfl_poll_msecs.
Why did you pick 2 seconds?
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Signed-off-by: Aaron Lu <redacted> --- block/genhd.c | 23 +++++++++++++++++------ drivers/scsi/sr.c | 1 + include/linux/genhd.h | 1 + 3 files changed, 19 insertions(+), 6 deletions(-)diff --git a/block/genhd.c b/block/genhd.c index bdb3682..de9b9d9 100644 --- a/block/genhd.c +++ b/block/genhd.c@@ -1619,6 +1619,19 @@ static void disk_events_workfn(struct work_struct *work) kobject_uevent_env(&disk_to_dev(disk)->kobj, KOBJ_CHANGE, envp); } +int disk_events_set_poll_msecs(struct gendisk *disk, long intv) +{ + if (intv < 0 && intv != -1) + return -EINVAL; + + disk_block_events(disk); + disk->ev->poll_msecs = intv; + __disk_unblock_events(disk, true); + + return 0; +} +EXPORT_SYMBOL(disk_events_set_poll_msecs); + /* * A disk events enabled device has the following sysfs nodes under * its /sys/block/X/ directory.@@ -1675,16 +1688,14 @@ static ssize_t disk_events_poll_msecs_store(struct device *dev, { struct gendisk *disk = dev_to_disk(dev); long intv; + int ret; if (!count || !sscanf(buf, "%ld", &intv)) return -EINVAL; - if (intv < 0 && intv != -1) - return -EINVAL; - - disk_block_events(disk); - disk->ev->poll_msecs = intv; - __disk_unblock_events(disk, true); + ret = disk_events_set_poll_msecs(disk, intv); + if (ret) + return ret; return count; }diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c index 2f159aa..78c4226 100644 --- a/drivers/scsi/sr.c +++ b/drivers/scsi/sr.c@@ -869,6 +869,7 @@ static int sr_probe(struct device *dev) dev_set_drvdata(dev, cd); disk->flags |= GENHD_FL_REMOVABLE; add_disk(disk); + disk_events_set_poll_msecs(disk, 2000);
Could you check that disk event's poll_msecs is the default (-1) before setting it to 2s? I am thinking of a case when the probe happens after the call to disk_events_poll_msecs_store() and this code would overwrite the user specified value.
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sdev_printk(KERN_DEBUG, sdev, "Attached scsi CD-ROM %s\n", cd->cdi.name);diff --git a/include/linux/genhd.h b/include/linux/genhd.h index 017a7fb..7414fb5 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h@@ -418,6 +418,7 @@ extern void disk_block_events(struct gendisk *disk); extern void disk_unblock_events(struct gendisk *disk); extern void disk_flush_events(struct gendisk *disk, unsigned int mask); extern unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask); +extern int disk_events_set_poll_msecs(struct gendisk *disk, long intv); /* drivers/char/random.c */ extern void add_disk_randomness(struct gendisk *disk);
-Betty