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] 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)) {