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-rw-r--r--Documentation/scsi/st.rst5
-rw-r--r--drivers/scsi/scsi_error.c12
-rw-r--r--drivers/scsi/st.c73
-rw-r--r--drivers/scsi/st.h6
-rw-r--r--include/scsi/scsi_device.h9
5 files changed, 97 insertions, 8 deletions
diff --git a/Documentation/scsi/st.rst b/Documentation/scsi/st.rst
index d3b28c28d74c..b4a092faa9c8 100644
--- a/Documentation/scsi/st.rst
+++ b/Documentation/scsi/st.rst
@@ -157,6 +157,11 @@ enabled driver and mode options. The value in the file is a bit mask where the
bit definitions are the same as those used with MTSETDRVBUFFER in setting the
options.
+Each directory contains the entry 'position_lost_in_reset'. If this value is
+one, reading and writing to the device is blocked after device reset. Most
+devices rewind the tape after reset and the writes/read don't access the
+tape position the user expects.
+
A link named 'tape' is made from the SCSI device directory to the class
directory corresponding to the mode 0 auto-rewind device (e.g., st0).
diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 815e7d63f3e2..ec60e8a96b11 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -547,6 +547,18 @@ enum scsi_disposition scsi_check_sense(struct scsi_cmnd *scmd)
scsi_report_sense(sdev, &sshdr);
+ if (sshdr.sense_key == UNIT_ATTENTION) {
+ /*
+ * Increment the counters for Power on/Reset or New Media so
+ * that all ULDs interested in these can see that those have
+ * happened, even if someone else gets the sense data.
+ */
+ if (sshdr.asc == 0x28)
+ scmd->device->ua_new_media_ctr++;
+ else if (sshdr.asc == 0x29)
+ scmd->device->ua_por_ctr++;
+ }
+
if (scsi_sense_is_deferred(&sshdr))
return NEEDS_RETRY;
diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index ebbd50ec0cda..85867120c8a9 100644
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -163,9 +163,11 @@ static const char *st_formats[] = {
static int debugging = DEBUG;
+/* Setting these non-zero may risk recognizing resets */
#define MAX_RETRIES 0
#define MAX_WRITE_RETRIES 0
#define MAX_READY_RETRIES 0
+
#define NO_TAPE NOT_READY
#define ST_TIMEOUT (900 * HZ)
@@ -357,10 +359,18 @@ static int st_chk_result(struct scsi_tape *STp, struct st_request * SRpnt)
{
int result = SRpnt->result;
u8 scode;
+ unsigned int ctr;
DEB(const char *stp;)
char *name = STp->name;
struct st_cmdstatus *cmdstatp;
+ ctr = scsi_get_ua_por_ctr(STp->device);
+ if (ctr != STp->por_ctr) {
+ STp->por_ctr = ctr;
+ STp->pos_unknown = 1; /* ASC => power on / reset */
+ st_printk(KERN_WARNING, STp, "Power on/reset recognized.");
+ }
+
if (!result)
return 0;
@@ -413,10 +423,11 @@ static int st_chk_result(struct scsi_tape *STp, struct st_request * SRpnt)
if (cmdstatp->have_sense &&
cmdstatp->sense_hdr.asc == 0 && cmdstatp->sense_hdr.ascq == 0x17)
STp->cleaning_req = 1; /* ASC and ASCQ => cleaning requested */
- if (cmdstatp->have_sense && scode == UNIT_ATTENTION && cmdstatp->sense_hdr.asc == 0x29)
+ if (cmdstatp->have_sense && scode == UNIT_ATTENTION &&
+ cmdstatp->sense_hdr.asc == 0x29 && !STp->pos_unknown) {
STp->pos_unknown = 1; /* ASC => power on / reset */
-
- STp->pos_unknown |= STp->device->was_reset;
+ st_printk(KERN_WARNING, STp, "Power on/reset recognized.");
+ }
if (cmdstatp->have_sense &&
scode == RECOVERED_ERROR
@@ -952,7 +963,6 @@ 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;
}
}
@@ -969,6 +979,7 @@ static int test_ready(struct scsi_tape *STp, int do_wait)
{
int attentions, waits, max_wait, scode;
int retval = CHKRES_READY, new_session = 0;
+ unsigned int ctr;
unsigned char cmd[MAX_COMMAND_SIZE];
struct st_request *SRpnt = NULL;
struct st_cmdstatus *cmdstatp = &STp->buffer->cmdstat;
@@ -1025,6 +1036,13 @@ static int test_ready(struct scsi_tape *STp, int do_wait)
}
}
+ ctr = scsi_get_ua_new_media_ctr(STp->device);
+ if (ctr != STp->new_media_ctr) {
+ STp->new_media_ctr = ctr;
+ new_session = 1;
+ DEBC_printk(STp, "New tape session.");
+ }
+
retval = (STp->buffer)->syscall_result;
if (!retval)
retval = new_session ? CHKRES_NEW_SESSION : CHKRES_READY;
@@ -2930,14 +2948,17 @@ 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);
@@ -3636,9 +3657,23 @@ static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg)
retval = (-EIO);
goto out;
}
- reset_state(STp);
- /* remove this when the midlevel properly clears was_reset */
- STp->device->was_reset = 0;
+ reset_state(STp); /* Clears pos_unknown */
+
+ /* 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 &&
@@ -4384,6 +4419,9 @@ static int st_probe(struct device *dev)
goto out_idr_remove;
}
+ tpnt->new_media_ctr = scsi_get_ua_new_media_ctr(SDp);
+ tpnt->por_ctr = scsi_get_ua_por_ctr(SDp);
+
dev_set_drvdata(dev, tpnt);
@@ -4665,6 +4703,24 @@ options_show(struct device *dev, struct device_attribute *attr, char *buf)
}
static DEVICE_ATTR_RO(options);
+/**
+ * position_lost_in_reset_show - Value 1 indicates that reads, writes, etc.
+ * are blocked because a device reset has occurred and no operation positioning
+ * the tape has been issued.
+ * @dev: struct device
+ * @attr: attribute structure
+ * @buf: buffer to return formatted data in
+ */
+static ssize_t position_lost_in_reset_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct st_modedef *STm = dev_get_drvdata(dev);
+ struct scsi_tape *STp = STm->tape;
+
+ return sprintf(buf, "%d", STp->pos_unknown);
+}
+static DEVICE_ATTR_RO(position_lost_in_reset);
+
/* Support for tape stats */
/**
@@ -4849,6 +4905,7 @@ static struct attribute *st_dev_attrs[] = {
&dev_attr_default_density.attr,
&dev_attr_default_compression.attr,
&dev_attr_options.attr,
+ &dev_attr_position_lost_in_reset.attr,
NULL,
};
diff --git a/drivers/scsi/st.h b/drivers/scsi/st.h
index 1aaaf5369a40..0d7c4b8c2c8a 100644
--- a/drivers/scsi/st.h
+++ b/drivers/scsi/st.h
@@ -165,6 +165,7 @@ 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 */
@@ -172,11 +173,16 @@ struct scsi_tape {
unsigned char cleaning_req; /* cleaning requested? */
unsigned char first_tur; /* first TEST UNIT READY */
int block_size;
+ int changed_blksize;
int min_block;
int max_block;
int recover_count; /* From tape opening */
int recover_reg; /* From last status call */
+ /* The saved values of midlevel counters */
+ unsigned int new_media_ctr;
+ unsigned int por_ctr;
+
#if DEBUG
unsigned char write_pending;
int nbr_finished;
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index 7acd0ec82bb0..68dd49947d04 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -247,6 +247,9 @@ struct scsi_device {
unsigned int queue_stopped; /* request queue is quiesced */
bool offline_already; /* Device offline message logged */
+ unsigned int ua_new_media_ctr; /* Counter for New Media UNIT ATTENTIONs */
+ unsigned int ua_por_ctr; /* Counter for Power On / Reset UAs */
+
atomic_t disk_events_disable_depth; /* disable depth for disk events */
DECLARE_BITMAP(supported_events, SDEV_EVT_MAXBITS); /* supported events */
@@ -684,6 +687,12 @@ static inline int scsi_device_busy(struct scsi_device *sdev)
return sbitmap_weight(&sdev->budget_map);
}
+/* Macros to access the UNIT ATTENTION counters */
+#define scsi_get_ua_new_media_ctr(sdev) \
+ ((const unsigned int)(sdev->ua_new_media_ctr))
+#define scsi_get_ua_por_ctr(sdev) \
+ ((const unsigned int)(sdev->ua_por_ctr))
+
#define MODULE_ALIAS_SCSI_DEVICE(type) \
MODULE_ALIAS("scsi:t-" __stringify(type) "*")
#define SCSI_DEVICE_MODALIAS_FMT "scsi:t-0x%02x"
generated by cgit (git 2.34.1) at 2025-05-28 01:44:41 +0000