Don't allow two images to be split and tracked from a RAID LV at one time

Also, don't allow a splitmirror operation on a RAID LV that is already tracking
a split, unless the operation is to stop the tracking and complete the split.
Example:
~> lvconvert --splitmirrors 1 --trackchanges vg/lv /dev/sdc1
# Now tracking changes - image can be merged back or split-off for good
~> lvconvert --splitmirrors 1 -n new_name vg/lv /dev/sdc1
# ^ Completes split ^

If a split is performed on a RAID that is tracking an already split image and
PVs are provided, we must ensure that
 1) the already split LV is represented in the PVs
 2) we are careful to split only the tracked image

diff --git a/WHATS_NEW b/WHATS_NEW
index ed652f7dc24212d721275176aec3ad06b300d3fd..f2b6efe1ceec0be1da64c3f2f5e7d138470b979a 100644 (file)
--- a/WHATS_NEW
+++ b/WHATS_NEW
@@ -1,5 +1,6 @@
 Version 2.02.89 - 
 ==================================
+  Don't allow two images to be split and tracked from a RAID LV at one time
   Don't allow size change of RAID LV that is tracking changes for a split image
   Don't allow size change of RAID sub-LVs independently
   Don't allow name change of RAID LV that is tracking changes for a split image

diff --git a/lib/metadata/raid_manip.c b/lib/metadata/raid_manip.c
index 57611e101379f97e1587ad9cdc11abc02369f925..24d07f646d5c70c1df0947d92d41dea65e7294ee 100644 (file)
--- a/lib/metadata/raid_manip.c
+++ b/lib/metadata/raid_manip.c
@@ -26,20 +26,32 @@
 
 #define RAID_REGION_SIZE 1024
 
-int lv_is_raid_with_tracking(const struct logical_volume *lv)
+static int _lv_is_raid_with_tracking(const struct logical_volume *lv,
+                                    struct logical_volume **tracking)
 {
        uint32_t s;
        struct lv_segment *seg;
 
-       if (lv->status & RAID) {
-               seg = first_seg(lv);
+       *tracking = NULL;
+       seg = first_seg(lv);
 
-               for (s = 0; s < seg->area_count; s++)
-                       if (lv_is_visible(seg_lv(seg, s)) &&
-                           !(seg_lv(seg, s)->status & LVM_WRITE))
-                               return 1;
-       }
-       return 0;
+       if (!(lv->status & RAID))
+               return 0;
+
+       for (s = 0; s < seg->area_count; s++)
+               if (lv_is_visible(seg_lv(seg, s)) &&
+                   !(seg_lv(seg, s)->status & LVM_WRITE))
+                       *tracking = seg_lv(seg, s);
+
+
+       return *tracking ? 1 : 0;
+}
+
+int lv_is_raid_with_tracking(const struct logical_volume *lv)
+{
+       struct logical_volume *tracking;
+
+       return _lv_is_raid_with_tracking(lv, &tracking);
 }
 
 uint32_t lv_raid_image_count(const struct logical_volume *lv)
@@ -1051,6 +1063,8 @@ int lv_raid_split(struct logical_volume *lv, const char *split_name,
        struct dm_list removal_list, data_list;
        struct cmd_context *cmd = lv->vg->cmd;
        uint32_t old_count = lv_raid_image_count(lv);
+       struct logical_volume *tracking;
+       struct dm_list tracking_pvs;
 
        dm_list_init(&removal_list);
        dm_list_init(&data_list);
@@ -1079,6 +1093,25 @@ int lv_raid_split(struct logical_volume *lv, const char *split_name,
                return 0;
        }
 
+       /*
+        * We only allow a split while there is tracking if it is to
+        * complete the split of the tracking sub-LV
+        */
+       if (_lv_is_raid_with_tracking(lv, &tracking)) {
+               if (!_lv_is_on_pvs(tracking, splittable_pvs)) {
+                       log_error("Unable to split additional image from %s "
+                                 "while tracking changes for %s",
+                                 lv->name, tracking->name);
+                       return 0;
+               } else {
+                       /* Ensure we only split the tracking image */
+                       dm_list_init(&tracking_pvs);
+                       splittable_pvs = &tracking_pvs;
+                       if (!_get_pv_list_for_lv(tracking, splittable_pvs))
+                               return_0;
+               }
+       }
+
        if (!_raid_extract_images(lv, new_count, splittable_pvs, 1,
                                 &removal_list, &data_list)) {
                log_error("Failed to extract images from %s/%s",
@@ -1181,6 +1214,12 @@ int lv_raid_split_and_track(struct logical_volume *lv,
                return 0;
        }
 
+       /* Cannot track two split images at once */
+       if (lv_is_raid_with_tracking(lv)) {
+               log_error("Cannot track more than one split image at a time");
+               return 0;
+       }
+
        for (s = seg->area_count - 1; s >= 0; s--) {
                if (!_lv_is_on_pvs(seg_lv(seg, s), splittable_pvs))
                        continue;