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scsi: hisi_sas: Fix rescan after deleting a disk

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Removing an ATA device via sysfs means that the device may not be found
through re-scanning:

root@ubuntu:/home/john# lsscsi
[0:0:0:0] disk SanDisk LT0200MO P404 /dev/sda
[0:0:1:0] disk ATA HGST HUS724040AL A8B0 /dev/sdb
[0:0:8:0] enclosu 12G SAS Expander RevB -
root@ubuntu:/home/john# echo 1 > /sys/block/sdb/device/delete
root@ubuntu:/home/john# echo "- - -" > /sys/class/scsi_host/host0/scan
root@ubuntu:/home/john# lsscsi
[0:0:0:0] disk SanDisk LT0200MO P404 /dev/sda
[0:0:8:0] enclosu 12G SAS Expander RevB -
root@ubuntu:/home/john#

The problem is that the rescan of the device may conflict with the device
in being re-initialized, as follows:

 - In the rescan we call hisi_sas_slave_alloc() in store_scan() ->
   sas_user_scan() -> [__]scsi_scan_target() -> scsi_probe_and_add_lunc()
   -> scsi_alloc_sdev() -> hisi_sas_slave_alloc() -> hisi_sas_init_device()
   In hisi_sas_init_device() we issue an IT nexus reset for ATA devices

 - That IT nexus causes the remote PHY to go down and this triggers a bcast
   event

 - In parallel libsas processes the bcast event, finds that the phy is down
   and marks the device as gone

The hard reset issued in hisi_sas_init_device() is unncessary - as
described in the code comment - so remove it. Also set dev status as
HISI_SAS_DEV_NORMAL as the hisi_sas_init_device() call.

Link: https://lore.kernel.org/r/1652354134-171343-4-git-send-email-john.garry@huawei.com
Fixes: 36c6b7613e ("scsi: hisi_sas: Initialise devices in .slave_alloc callback")
Tested-by: Yihang Li <liyihang6@hisilicon.com>
Reviewed-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
John Garry 2022-05-12 19:15:34 +08:00 committed by Martin K. Petersen
parent 71453bd9d1
commit e9dedc13bb
1 changed files with 18 additions and 29 deletions
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47
drivers/scsi/hisi_sas/hisi_sas_main.c
View File

@ -709,8 +709,6 @@ static int hisi_sas_init_device(struct domain_device *device)
struct scsi_lun lun;
int retry = HISI_SAS_DISK_RECOVER_CNT;
struct hisi_hba *hisi_hba = dev_to_hisi_hba(device);
struct device *dev = hisi_hba->dev;
struct sas_phy *local_phy;
switch (device->dev_type) {
case SAS_END_DEVICE:
@ -729,30 +727,18 @@ static int hisi_sas_init_device(struct domain_device *device)
case SAS_SATA_PM_PORT:
case SAS_SATA_PENDING:
/*
* send HARD RESET to clear previous affiliation of
* STP target port
* If an expander is swapped when a SATA disk is attached then
* we should issue a hard reset to clear previous affiliation
* of STP target port, see SPL (chapter 6.19.4).
*
* However we don't need to issue a hard reset here for these
* reasons:
* a. When probing the device, libsas/libata already issues a
* hard reset in sas_probe_sata() -> ata_sas_async_probe().
* Note that in hisi_sas_debug_I_T_nexus_reset() we take care
* to issue a hard reset by checking the dev status (== INIT).
* b. When resetting the controller, this is simply unnecessary.
*/
local_phy = sas_get_local_phy(device);
if (!scsi_is_sas_phy_local(local_phy) &&
!test_bit(HISI_SAS_RESETTING_BIT, &hisi_hba->flags)) {
unsigned long deadline = ata_deadline(jiffies, 20000);
struct sata_device *sata_dev = &device->sata_dev;
struct ata_host *ata_host = sata_dev->ata_host;
struct ata_port_operations *ops = ata_host->ops;
struct ata_port *ap = sata_dev->ap;
struct ata_link *link;
unsigned int classes;
ata_for_each_link(link, ap, EDGE)
rc = ops->hardreset(link, &classes,
deadline);
}
sas_put_local_phy(local_phy);
if (rc) {
dev_warn(dev, "SATA disk hardreset fail: %d\n", rc);
return rc;
}
while (retry-- > 0) {
rc = hisi_sas_softreset_ata_disk(device);
if (!rc)
@ -768,15 +754,19 @@ static int hisi_sas_init_device(struct domain_device *device)
int hisi_sas_slave_alloc(struct scsi_device *sdev)
{
struct domain_device *ddev;
struct domain_device *ddev = sdev_to_domain_dev(sdev);
struct hisi_sas_device *sas_dev = ddev->lldd_dev;
int rc;
rc = sas_slave_alloc(sdev);
if (rc)
return rc;
ddev = sdev_to_domain_dev(sdev);
return hisi_sas_init_device(ddev);
rc = hisi_sas_init_device(ddev);
if (rc)
return rc;
sas_dev->dev_status = HISI_SAS_DEV_NORMAL;
return 0;
}
EXPORT_SYMBOL_GPL(hisi_sas_slave_alloc);
@ -826,7 +816,6 @@ static int hisi_sas_dev_found(struct domain_device *device)
dev_info(dev, "dev[%d:%x] found\n",
sas_dev->device_id, sas_dev->dev_type);
sas_dev->dev_status = HISI_SAS_DEV_NORMAL;
return 0;
err_out: