在 2023/9/5 15:44, Damien Le Moal 写道:
On 9/5/23 12:48, linan666@xxxxxxxxxxxxxxx wrote:
From: Li Nan <linan122@xxxxxxxxxx>
Please change the patch title to something like:
ata: libata-eh: Honor all EH scheduling requests
Because the issue could happen I think with other ata drivers than AHCI.
If a disk is removed and quickly inserted when an I/O error is processing,
the disk may not be able to be re-added. The function call timeline is as
follows:
interrupt scsi_eh
ahci_error_intr
ata_port_freeze
__ata_port_freeze
=>ahci_freeze (turn IRQ off)
ata_port_abort
ata_do_link_abort
ata_port_schedule_eh
=>ata_std_sched_eh
ata_eh_set_pending
set EH_PENDING
scsi_schedule_eh
shost->host_eh_scheduled++ (=1)
scsi_error_handler
=>ata_scsi_error
ata_scsi_port_error_handler
clear EH_PENDING
=>ahci_error_handler
. sata_pmp_error_handler
. ata_eh_reset
. ata_eh_thaw_port
. . =>ahci_thaw (turn IRQ on)
ahci_error_intr . .
ata_port_freeze . .
__ata_port_freeze . .
=>ahci_freeze (turn IRQ off) . .
... . .
ata_eh_set_pending . .
set EH_PENDING . .
scsi_schedule_eh . .
shost->host_eh_scheduled++ (=2) . .
. clear EH_PENDING
check EH_PENDING
=>ata_std_end_eh
host->host_eh_scheduled = 0;
'host_eh_scheduled' is 0 and scsi eh thread will not be scheduled again.
The ata port remain freeze and will never be enabled.
s/remain freeze/remains frozen
Decrease ’host_eh_scheduled‘ instead of set it to 0 roughly and move
WARN_ON of nr_active_links to ata_scsi_port_error_handler().
To fix this issue, decrease ’host_eh_scheduled‘ instead of setting it to 0 so
that EH is scheduled again to re-enable the port. Also move the update of
nr_active_links to 0 when host_eh_scheduled is 0 to ata_scsi_port_error_handler().
Thanks for your review. I will improve the commmit message.
Reported-by: luojian <luojian5@xxxxxxxxxx>
Signed-off-by: Li Nan <linan122@xxxxxxxxxx>
---
Changes in v2:
- fix the bug by decrease 'host_eh_scheduled’
- improve commit message.
drivers/ata/libata-eh.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 159ba6ba19eb..b9454756ecde 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -735,6 +735,12 @@ void ata_scsi_port_error_handler(struct Scsi_Host *host, struct ata_port *ap)
*/
ap->ops->end_eh(ap);
+ if (!ap->scsi_host->host_eh_scheduled) {
+ /* make sure nr_active_links is zero after EH */
+ WARN_ON(ap->nr_active_links);
+ ap->nr_active_links = 0;> + }
+
spin_unlock_irqrestore(ap->lock, flags);
ata_eh_release(ap);
@@ -948,7 +954,7 @@ void ata_std_end_eh(struct ata_port *ap)
{
struct Scsi_Host *host = ap->scsi_host;
- host->host_eh_scheduled = 0;
+ host->host_eh_scheduled--;
While at it, please drop the host variable:
ap->scsi_host->host_eh_scheduled--;
is just fine.
I agree. I will change it in next version.
}
EXPORT_SYMBOL(ata_std_end_eh);
@@ -3922,10 +3928,6 @@ void ata_eh_finish(struct ata_port *ap)
}
}
}
-
- /* make sure nr_active_links is zero after EH */
- WARN_ON(ap->nr_active_links);
- ap->nr_active_links = 0;
}
/**
--
Thanks,
Nan
