From 95afb4afbbdc8e7fdf98afdea82e109d62d2f96d Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Kai=20M=C3=A4kisara?= Date: Mon, 20 Jan 2025 21:49:22 +0200 Subject: [PATCH] scsi: st: Restore some drive settings after reset MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit [ Upstream commit 7081dc75df79696d8322d01821c28e53416c932c ] Some of the allowed operations put the tape into a known position to continue operation assuming only the tape position has changed. But reset sets partition, density and block size to drive default values. These should be restored to the values before reset. Normally the current block size and density are stored by the drive. If the settings have been changed, the changed values have to be saved by the driver across reset. Signed-off-by: Kai Mäkisara Link: https://lore.kernel.org/r/20250120194925.44432-2-Kai.Makisara@kolumbus.fi Reviewed-by: John Meneghini Tested-by: John Meneghini Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin --- drivers/scsi/st.c | 24 +++++++++++++++++++++--- drivers/scsi/st.h | 2 ++ 2 files changed, 23 insertions(+), 3 deletions(-) diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c index 3f798f87e8d9..d4aef346bfee 100644 --- a/drivers/scsi/st.c +++ b/drivers/scsi/st.c @@ -949,7 +949,6 @@ static void reset_state(struct scsi_tape *STp) STp->partition = find_partition(STp); if (STp->partition < 0) STp->partition = 0; - STp->new_partition = STp->partition; } } @@ -2921,14 +2920,17 @@ static int st_int_ioctl(struct scsi_tape *STp, unsigned int cmd_in, unsigned lon if (cmd_in == MTSETDENSITY) { (STp->buffer)->b_data[4] = arg; STp->density_changed = 1; /* At least we tried ;-) */ + STp->changed_density = arg; } else if (cmd_in == SET_DENS_AND_BLK) (STp->buffer)->b_data[4] = arg >> 24; else (STp->buffer)->b_data[4] = STp->density; if (cmd_in == MTSETBLK || cmd_in == SET_DENS_AND_BLK) { ltmp = arg & MT_ST_BLKSIZE_MASK; - if (cmd_in == MTSETBLK) + if (cmd_in == MTSETBLK) { STp->blksize_changed = 1; /* At least we tried ;-) */ + STp->changed_blksize = arg; + } } else ltmp = STp->block_size; (STp->buffer)->b_data[9] = (ltmp >> 16); @@ -3629,9 +3631,25 @@ static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg) retval = (-EIO); goto out; } - reset_state(STp); + reset_state(STp); /* Clears pos_unknown */ /* remove this when the midlevel properly clears was_reset */ STp->device->was_reset = 0; + + /* Fix the device settings after reset, ignore errors */ + if (mtc.mt_op == MTREW || mtc.mt_op == MTSEEK || + mtc.mt_op == MTEOM) { + if (STp->can_partitions) { + /* STp->new_partition contains the + * latest partition set + */ + STp->partition = 0; + switch_partition(STp); + } + if (STp->density_changed) + st_int_ioctl(STp, MTSETDENSITY, STp->changed_density); + if (STp->blksize_changed) + st_int_ioctl(STp, MTSETBLK, STp->changed_blksize); + } } if (mtc.mt_op != MTNOP && mtc.mt_op != MTSETBLK && diff --git a/drivers/scsi/st.h b/drivers/scsi/st.h index 95d2e7a7988d..c9947abb0a45 100644 --- a/drivers/scsi/st.h +++ b/drivers/scsi/st.h @@ -168,12 +168,14 @@ struct scsi_tape { unsigned char compression_changed; unsigned char drv_buffer; unsigned char density; + unsigned char changed_density; unsigned char door_locked; unsigned char autorew_dev; /* auto-rewind device */ unsigned char rew_at_close; /* rewind necessary at close */ unsigned char inited; unsigned char cleaning_req; /* cleaning requested? */ int block_size; + int changed_blksize; int min_block; int max_block; int recover_count; /* From tape opening */