Merge: st tape driver patches in RHEL 9 missing from RHEL 10

MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-10/-/merge_requests/1677

The following patches are present in RHEL 9, but not in RHEL 10:

JIRA: https://issues.redhat.com/browse/RHEL-124946

R9 C9 LT LS SF SQ SS 5bb2d61
scsi: st: Don't modify unknown block number in MTIOCGET
R8 R9 C9 LT LS SF SQ SS 0b120ed
scsi: st: Add MTIOCGET and MTLOAD to ioctls allowed after device reset
R8 R9 C9 LT LS SF SQ SS a4550b2
scsi: st: New session only when Unit Attention for new tape
R8 R9 C9 LT LS SF SQ SS 98b3788
scsi: st: Don't set pos_unknown just after device recognition

Signed-off-by: Ewan D. Milne <emilne@redhat.com>

Approved-by: Tomas Henzl <thenzl@redhat.com>
Approved-by: Chris Leech <cleech@redhat.com>
Approved-by: John Meneghini <jmeneghi@redhat.com>
Approved-by: Ming Lei <ming.lei@redhat.com>
Approved-by: CKI KWF Bot <cki-ci-bot+kwf-gitlab-com@redhat.com>

Merged-by: CKI GitLab Kmaint Pipeline Bot <26919896-cki-kmaint-pipeline-bot@users.noreply.gitlab.com>

Author: CKI KWF Bot

drivers/scsi/st.c

@@ -1002,7 +1002,10 @@ 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;
@@ -1045,6 +1048,11 @@ static int test_ready(struct scsi_tape *STp, int do_wait)
 			retval = new_session ? CHKRES_NEW_SESSION : CHKRES_READY;
 		break;
 	}
+	if (STp->first_tur) {
+		/* Don't set pos_unknown right after device recognition */
+		STp->pos_unknown = 0;
+		STp->first_tur = 0;
+	}
 
 	if (SRpnt != NULL)
 		st_release_request(SRpnt);
@@ -3528,6 +3536,7 @@ 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;
@@ -3641,6 +3650,7 @@ 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 &&
@@ -3768,17 +3778,28 @@ 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)) {
@@ -3792,7 +3813,7 @@ 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;
@@ -4348,6 +4369,7 @@ static int st_probe(struct device *dev)
 	blk_queue_rq_timeout(tpnt->device->request_queue, ST_TIMEOUT);
 	tpnt->long_timeout = ST_LONG_TIMEOUT;
 	tpnt->try_dio = try_direct_io;
+	tpnt->first_tur = 1;
 
 	for (i = 0; i < ST_NBR_MODES; i++) {
 		STm = &(tpnt->modes[i]);

drivers/scsi/st.h

@@ -171,6 +171,7 @@ struct scsi_tape {
 	unsigned char rew_at_close;  /* rewind necessary at close */
 	unsigned char inited;
 	unsigned char cleaning_req;  /* cleaning requested? */
+	unsigned char first_tur;     /* first TEST UNIT READY */
 	int block_size;
 	int changed_blksize;
 	int min_block;