[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-ID: <20090904172316.GA6076@clala-laptop>
Date: Fri, 4 Sep 2009 10:23:16 -0700
From: Chaitanya Lala <clala@...erbed.com>
To: tj@...nel.org
Cc: clala@...erbed.com, rbecker@...erbed.com,
linux-kernel@...r.kernel.org
Subject: Disk failure behavior
Hi,
I am using a back-port of libata from ~ 2.6.20 on a 2.6.9
Red Hat kernel. I have SATA disks (using AHCI) in the
system which are hot-pluggable. The problem I am facing
is that, certain disk failures bring the system into a
weird state. The system tries to reset the disk but fails.
Finally it prints a message "reset failed, giving up."
At this point the port is left in a frozen state and
the interrupts from the port are masked. If now, this disk is
pulled out and a healthy disk is inserted, the new disk's
insertion does not raise any event/notification/interrupt.
In fact, the only way at this point to get the disk to work is
to reboot.
Below is a snippet of the code, I am referring to, from v2.6.20.
File - drivers/ata/libata-eh.c & function-name - ata_eh_recover
/* reset */
if (ehc->i.action & ATA_EH_RESET_MASK) {
ata_eh_freeze_port(ap);
rc = ata_eh_reset(ap, ata_port_nr_vacant(ap), prereset,
softreset, hardreset, postreset);
if (rc) {
ata_port_printk(ap, KERN_ERR,
"reset failed, giving up\n");
goto out;
}
ata_eh_thaw_port(ap);
}
A possible work-around is to thaw the port before going to "out".
That would enable the interrupts again before going to "out".
I understand that would enable future interrupts from the old disk as well,
but I am willing to live with that, if it helps to detect the new device.
/* reset */
if (ehc->i.action & ATA_EH_RESET_MASK) {
ata_eh_freeze_port(ap);
rc = ata_eh_reset(ap, ata_port_nr_vacant(ap), prereset,
softreset, hardreset, postreset);
if (rc) {
ata_port_printk(ap, KERN_ERR,
"reset failed, giving up\n");
+ ata_eh_thaw_port(ap);
goto out;
}
ata_eh_thaw_port(ap);
}
I have tested this successfully. But I would like to ask you if this would
possibly "break" some other functionality ? I am new to the kernel ata stuff
and want to be sure before I use this.
Thanks,
Chaitanya
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists