There is a scenario where a large number of discard commands are issued when the iscsi initiator connects to the target and then performs a session rescan operation. There is a time window, most of the commands are in UNMAP mode, and some discard commands become WRITE SAME with UNMAP. The discard mode has been negotiated during the SCSI probe. If the mode is temporarily changed from UNMAP to WRITE SAME with UNMAP, IO ERROR may occur because the target may not implement WRITE SAME with UNMAP. Keep the discard mode stable to fix this issue. Signed-off-by: Li Feng <fengli@xxxxxxxxxx> Reviewed-by: Christoph Hellwig <hch@xxxxxx> Reviewed-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx> --- drivers/scsi/sd.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 8bb3a3611851..c180427e2c98 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -2711,8 +2711,6 @@ static int read_capacity_16(struct scsi_disk *sdkp, struct scsi_device *sdp, if (buffer[14] & 0x40) /* LBPRZ */ sdkp->lbprz = 1; - - sd_config_discard(sdkp, lim, SD_LBP_WS16); } sdkp->capacity = lba + 1; @@ -3365,8 +3363,6 @@ static void sd_read_block_limits(struct scsi_disk *sdkp, sdkp->unmap_alignment = get_unaligned_be32(&vpd->data[32]) & ~(1 << 31); - sd_config_discard(sdkp, lim, sd_discard_mode(sdkp)); - config_atomic: sdkp->max_atomic = get_unaligned_be32(&vpd->data[44]); sdkp->atomic_alignment = get_unaligned_be32(&vpd->data[48]); @@ -3756,6 +3752,8 @@ static int sd_revalidate_disk(struct gendisk *disk) sd_read_cpr(sdkp); } + sd_config_discard(sdkp, &lim, sd_discard_mode(sdkp)); + sd_print_capacity(sdkp, old_capacity); sd_read_write_protect_flag(sdkp, buffer); -- 2.45.2
