Re: [PATCH 2/2] scsi: ufs: Return a bsg request immediatley if eh-in-progress

From: Bart Van Assche
Date: Mon Nov 08 2021 - 12:16:54 EST


On 11/8/21 4:08 AM, Avri Altman wrote:
ufs-bsg is attempting to access the device from user-space, and it is
unaware of the internal driver flows, specifically if error handling is
currently ongoing.

Fixes: 5e0a86eed846 (scsi: ufs: Add API to execute raw upiu commands)

Signed-off-by: Avri Altman <avri.altman@xxxxxxx>
---
drivers/scsi/ufs/ufshcd.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 3869bb57769b..828061c05909 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -6830,6 +6830,9 @@ int ufshcd_exec_raw_upiu_cmd(struct ufs_hba *hba,
enum utp_ocs ocs_value;
u8 tm_f = be32_to_cpu(req_upiu->header.dword_1) >> 16 & MASK_TM_FUNC;
+ if (!ufshcd_is_user_access_allowed(hba))
+ return -EBUSY;
+
switch (msgcode) {
case UPIU_TRANSACTION_NOP_OUT:
cmd_type = DEV_CMD_TYPE_NOP;

Making operations fail if error handling is in progress makes it harder than
necessary to write user space software that uses the BSG interface. Has it
been considered to wait inside ufshcd_exec_raw_upiu_cmd() until error handling
has finished?

Thanks,

Bart.