dcssblk: issue warning when trying to save SN/EN type DCSS

The content of a DCSS of type SN or EN cannot be saved. Issue a warning when
trying to save such a DCSS. Depending on the setup, this may be a user error
or intended behaviour e.g. with a multi-DCSS device.

Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 13 insertions, 2 deletions

diff --git a/drivers/s390/block/dcssblk.c b/drivers/s390/block/dcssblk.c
index b550c8c8d010..7f900229404d 100644
--- a/drivers/s390/block/dcssblk.c
+++ b/drivers/s390/block/dcssblk.c
@@ -438,7 +438,13 @@ dcssblk_save_store(struct device *dev, struct device_attribute *attr, const char
                         pr_info("All DCSSs that map to device %s are "
                                 "saved\n", dev_info->segment_name);
                         list_for_each_entry(entry, &dev_info->seg_list, lh) {
-                                segment_save(entry->segment_name);
+                                if (entry->segment_type == SEG_TYPE_EN ||
+                                    entry->segment_type == SEG_TYPE_SN)
+                                        pr_warn("DCSS %s is of type SN or EN"
+                                                " and cannot be saved\n",
+                                                entry->segment_name);
+                                else
+                                        segment_save(entry->segment_name);
                         }
                 }  else {
                         // device is busy => we save it when it becomes
@@ -797,7 +803,12 @@ dcssblk_release(struct gendisk *disk, fmode_t mode)
                 pr_info("Device %s has become idle and is being saved "
                         "now\n", dev_info->segment_name);
                 list_for_each_entry(entry, &dev_info->seg_list, lh) {
-                        segment_save(entry->segment_name);
+                        if (entry->segment_type == SEG_TYPE_EN ||
+                            entry->segment_type == SEG_TYPE_SN)
+                                pr_warn("DCSS %s is of type SN or EN and cannot"
+                                        " be saved\n", entry->segment_name);
+                        else
+                                segment_save(entry->segment_name);
                 }
                 dev_info->save_pending = 0;
         }