2 files changed, 49 insertions, 1 deletions

diff --git a/Documentation/scsi/st.txt b/Documentation/scsi/st.txt
index 38f81188def0..40752602c050 100644
--- a/Documentation/scsi/st.txt
+++ b/Documentation/scsi/st.txt
@@ -2,7 +2,7 @@ This file contains brief information about the SCSI tape driver.
 The driver is currently maintained by Kai Mäkisara (email
 Kai.Makisara@kolumbus.fi)
 
-Last modified: Thu Feb 21 21:54:16 2008 by kai.makisara
+Last modified: Sun Feb 24 21:59:07 2008 by kai.makisara
 
 
 BASICS
@@ -133,6 +133,11 @@ the defaults set by the user. The value -1 means the default is not set. The
 file 'dev' contains the device numbers corresponding to this device. The links
 'device' and 'driver' point to the SCSI device and driver entries.
 
+Each directory also contains the entry 'options' which shows the currently
+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.
+
 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/st.c b/drivers/scsi/st.c
index a4361a8c6ac6..d204aad2e683 100644
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -4365,6 +4365,46 @@ static ssize_t st_defcompression_show(struct class_device *class_dev, char *buf)
 
 CLASS_DEVICE_ATTR(default_compression, S_IRUGO, st_defcompression_show, NULL);
 
+static ssize_t st_options_show(struct class_device *class_dev, char *buf)
+{
+        struct st_modedef *STm = (struct st_modedef *)class_get_devdata(class_dev);
+        struct scsi_tape *STp;
+        int i, j, options;
+        ssize_t l = 0;
+
+        for (i=0; i < st_dev_max; i++) {
+                for (j=0; j < ST_NBR_MODES; j++)
+                        if (&scsi_tapes[i]->modes[j] == STm)
+                                break;
+                if (j < ST_NBR_MODES)
+                        break;
+        }
+        if (i == st_dev_max)
+                return 0;  /* should never happen */
+
+        STp = scsi_tapes[i];
+
+        options = STm->do_buffer_writes ? MT_ST_BUFFER_WRITES : 0;
+        options |= STm->do_async_writes ? MT_ST_ASYNC_WRITES : 0;
+        options |= STm->do_read_ahead ? MT_ST_READ_AHEAD : 0;
+        DEB( options |= debugging ? MT_ST_DEBUGGING : 0 );
+        options |= STp->two_fm ? MT_ST_TWO_FM : 0;
+        options |= STp->fast_mteom ? MT_ST_FAST_MTEOM : 0;
+        options |= STm->defaults_for_writes ? MT_ST_DEF_WRITES : 0;
+        options |= STp->can_bsr ? MT_ST_CAN_BSR : 0;
+        options |= STp->omit_blklims ? MT_ST_NO_BLKLIMS : 0;
+        options |= STp->can_partitions ? MT_ST_CAN_PARTITIONS : 0;
+        options |= STp->scsi2_logical ? MT_ST_SCSI2LOGICAL : 0;
+        options |= STm->sysv ? MT_ST_SYSV : 0;
+        options |= STp->immediate ? MT_ST_NOWAIT : 0;
+        options |= STp->sili ? MT_ST_SILI : 0;
+
+        l = snprintf(buf, PAGE_SIZE, "0x%08x\n", options);
+        return l;
+}
+
+CLASS_DEVICE_ATTR(options, S_IRUGO, st_options_show, NULL);
+
 static int do_create_class_files(struct scsi_tape *STp, int dev_num, int mode)
 {
         int i, rew, error;
@@ -4402,6 +4442,9 @@ static int do_create_class_files(struct scsi_tape *STp, int dev_num, int mode)
                 error = class_device_create_file(st_class_member,
                                         &class_device_attr_default_compression);
                 if (error) goto out;
+                error = class_device_create_file(st_class_member,
+                                        &class_device_attr_options);
+                if (error) goto out;
 
                 if (mode == 0 && rew == 0) {
                         error = sysfs_create_link(&STp->device->sdev_gendev.kobj,