On Sun, 15 Jun 2008 21:00:10 -0500 James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx> wrote: > On Sun, 2008-06-15 at 18:01 -0700, Andrew Morton wrote: > > On Sun, 15 Jun 2008 01:52:26 -0700 (PDT) bugme-daemon@xxxxxxxxxxxxxxxxxxx wrote: > > > > > http://bugzilla.kernel.org/show_bug.cgi?id=10915 > > > > > > Summary: echo min_power > /sys/class/scsi_host/host0/active_mode > > > causes problem > > > Product: File System > > > Version: 2.5 > > > KernelVersion: 2.6.25.6 > > > Platform: All > > > OS/Version: Linux > > > Tree: Mainline > > > Status: NEW > > > Severity: normal > > > Priority: P1 > > > Component: SysFS > > > AssignedTo: greg@xxxxxxxxx > > > ReportedBy: cijoml@xxxxxxxx > > > > > > > > > Latest working kernel version: unknown > > > Earliest failing kernel version: unknown > > > Distribution: Debian testing > > > Hardware Environment: HP Compaq 6910p > > > Software Environment: Debian testing, sysfs > > > Problem Description: > > > > > > In accident I proceed > > > echo min_power > /sys/class/scsi_host/host0/active_mode > > > > > > which causes HIGH cpu load, echo wasn't killable so reboot was only solution :( > > > > > > Steps to reproduce: > > > proceed command > > > > For reasons which escape me, there is no description text in bugzilla > > for this report, yet the reporter entered some. > > > > Anyway. Could someone please refile this under scsi? Or fix the bug ;) > > Um ... actually, maybe not. The active_mode file is read only (it has a > NULL store method). It's designed to show what mode the host is > activated in "initiator", "target" (or both or unknown). If echoing > something to a read only sysfs file with no actual store method is > causing this behaviour, the root cause has to be somewhere in sysfs. This bug doesn't happen with the latest git so I guess that the root cause was fixed, which can't handle the NULL store method properly. But I think that it would be better to set active_mode and support_mode files to read-only (though in the future, active_mode would be changeable for a dual-mode driver). > However, since the file has nothing to do with power saving ... unless > some driver I can't find is trying to duplicate it, so there's no reason > to try to echo "min_power" to it, so some of the details on this report > might bear further investigation ... I guess that he intended to echo "min_power" to link_power_management_policy file. = From: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx> Subject: [PATCH] set active_mode and support_mode sysfs files to read-only Signed-off-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx> --- drivers/scsi/scsi_sysfs.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c index 93d2b67..01191bb 100644 --- a/drivers/scsi/scsi_sysfs.c +++ b/drivers/scsi/scsi_sysfs.c @@ -227,7 +227,7 @@ show_shost_supported_mode(struct device *dev, struct device_attribute *attr, return show_shost_mode(supported_mode, buf); } -static DEVICE_ATTR(supported_mode, S_IRUGO | S_IWUSR, show_shost_supported_mode, NULL); +static DEVICE_ATTR(supported_mode, S_IRUGO, show_shost_supported_mode, NULL); static ssize_t show_shost_active_mode(struct device *dev, @@ -241,7 +241,7 @@ show_shost_active_mode(struct device *dev, return show_shost_mode(shost->active_mode, buf); } -static DEVICE_ATTR(active_mode, S_IRUGO | S_IWUSR, show_shost_active_mode, NULL); +static DEVICE_ATTR(active_mode, S_IRUGO, show_shost_active_mode, NULL); shost_rd_attr(unique_id, "%u\n"); shost_rd_attr(host_busy, "%hu\n"); -- 1.5.5.GIT -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
