From 5bb2d6179d1a8039236237e1e94cfbda3be1ed9e Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Kai=20M=C3=A4kisara?= Date: Wed, 6 Nov 2024 11:57:21 +0200 Subject: [PATCH 1/3] scsi: st: Don't modify unknown block number in MTIOCGET MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Struct mtget field mt_blkno -1 means it is unknown. Don't add anything to it. Signed-off-by: Kai Mäkisara Link: https://bugzilla.kernel.org/show_bug.cgi?id=219419#c14 Link: https://lore.kernel.org/r/20241106095723.63254-2-Kai.Makisara@kolumbus.fi Reviewed-by: John Meneghini Tested-by: John Meneghini Signed-off-by: Martin K. Petersen --- drivers/scsi/st.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c index d50bad3a2ce92..9f480a1b4a81a 100644 --- a/drivers/scsi/st.c +++ b/drivers/scsi/st.c @@ -3756,7 +3756,7 @@ static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg) ((STp->density << MT_ST_DENSITY_SHIFT) & MT_ST_DENSITY_MASK); mt_status.mt_blkno = STps->drv_block; mt_status.mt_fileno = STps->drv_file; - if (STp->block_size != 0) { + if (STp->block_size != 0 && mt_status.mt_blkno >= 0) { if (STps->rw == ST_WRITING) mt_status.mt_blkno += (STp->buffer)->buffer_bytes / STp->block_size; From 0b120edb37dc9dd8ca82893d386922eb6b16f860 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Kai=20M=C3=A4kisara?= Date: Wed, 6 Nov 2024 11:57:22 +0200 Subject: [PATCH 2/3] scsi: st: Add MTIOCGET and MTLOAD to ioctls allowed after device reset MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Most drives rewind the tape when the device is reset. Reading and writing are not allowed until something is done to make the tape position match the user's expectation (e.g., rewind the tape). Add MTIOCGET and MTLOAD to operations allowed after reset. MTIOCGET is modified to not touch the tape if pos_unknown is non-zero. The tape location is known after MTLOAD. Signed-off-by: Kai Mäkisara Link: https://bugzilla.kernel.org/show_bug.cgi?id=219419#c14 Link: https://lore.kernel.org/r/20241106095723.63254-3-Kai.Makisara@kolumbus.fi Reviewed-by: John Meneghini Tested-by: John Meneghini Signed-off-by: Martin K. Petersen --- drivers/scsi/st.c | 29 +++++++++++++++++++++-------- 1 file changed, 21 insertions(+), 8 deletions(-) diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c index 9f480a1b4a81a..4863802371a70 100644 --- a/drivers/scsi/st.c +++ b/drivers/scsi/st.c @@ -3506,6 +3506,7 @@ static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg) int i, cmd_nr, cmd_type, bt; int retval = 0; unsigned int blk; + bool cmd_mtiocget; struct scsi_tape *STp = file->private_data; struct st_modedef *STm; struct st_partstat *STps; @@ -3619,6 +3620,7 @@ static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg) */ if (mtc.mt_op != MTREW && mtc.mt_op != MTOFFL && + mtc.mt_op != MTLOAD && mtc.mt_op != MTRETEN && mtc.mt_op != MTERASE && mtc.mt_op != MTSEEK && @@ -3732,17 +3734,28 @@ static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg) goto out; } + cmd_mtiocget = cmd_type == _IOC_TYPE(MTIOCGET) && cmd_nr == _IOC_NR(MTIOCGET); + if ((i = flush_buffer(STp, 0)) < 0) { - retval = i; - goto out; - } - if (STp->can_partitions && - (i = switch_partition(STp)) < 0) { - retval = i; - goto out; + if (cmd_mtiocget && STp->pos_unknown) { + /* flush fails -> modify status accordingly */ + reset_state(STp); + STp->pos_unknown = 1; + } else { /* return error */ + retval = i; + goto out; + } + } else { /* flush_buffer succeeds */ + if (STp->can_partitions) { + i = switch_partition(STp); + if (i < 0) { + retval = i; + goto out; + } + } } - if (cmd_type == _IOC_TYPE(MTIOCGET) && cmd_nr == _IOC_NR(MTIOCGET)) { + if (cmd_mtiocget) { struct mtget mt_status; if (_IOC_SIZE(cmd_in) != sizeof(struct mtget)) { From a4550b28c8c853e7241ecf30b4f1d9c6bc631fda Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Kai=20M=C3=A4kisara?= Date: Wed, 6 Nov 2024 11:57:23 +0200 Subject: [PATCH 3/3] scsi: st: New session only when Unit Attention for new tape MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Currently the code starts new tape session when any Unit Attention (UA) is seen when opening the device. This leads to incorrectly clearing pos_unknown when the UA is for reset. Set new session only when the UA is for a new tape. Signed-off-by: Kai Mäkisara Link: https://lore.kernel.org/r/20241106095723.63254-4-Kai.Makisara@kolumbus.fi Reviewed-by: John Meneghini Tested-by: John Meneghini Signed-off-by: Martin K. Petersen --- drivers/scsi/st.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c index 4863802371a70..fe0618ac9769f 100644 --- a/drivers/scsi/st.c +++ b/drivers/scsi/st.c @@ -991,7 +991,10 @@ static int test_ready(struct scsi_tape *STp, int do_wait) scode = cmdstatp->sense_hdr.sense_key; if (scode == UNIT_ATTENTION) { /* New media? */ - new_session = 1; + if (cmdstatp->sense_hdr.asc == 0x28) { /* New media */ + new_session = 1; + DEBC_printk(STp, "New tape session."); + } if (attentions < MAX_ATTENTIONS) { attentions++; continue;