Messages in this thread | | | Date | Fri, 4 Sep 2009 10:23:16 -0700 | From | Chaitanya Lala <> | Subject | Disk failure behavior |
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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
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