[PATCH 2/2 v2] LVM Cachevol and Integrity volumes break entire LVM VG

From: Patrick Plenefisch <simonpatp@gmail.com>
To: The development of GNU GRUB <grub-devel@gnu.org>
Subject: [PATCH 2/2 v2] LVM Cachevol and Integrity volumes break entire LVM VG
Date: Fri, 26 Apr 2024 21:00:08 -0400	[thread overview]
Message-ID: <CAOCpoWcobwPuYQJyRAAunncTOXb0b-VW2zaxtBnCn4aWKXLSRg@mail.gmail.com> (raw)

From 8cfb6dbb011d3773b90a3cbb8561616a2fb5955f Mon Sep 17 00:00:00 2001
From: Patrick Plenefisch <simonpatp@gmail.com>
Date: Sun, 18 Feb 2024 18:36:05 -0500
Subject: [PATCH 2/2] lvm: Add support for cachevol and integrity lv

lv matching must be done after processing, as integrity
volumes may have several levels that the segments must be
shifted through

pv matching must be completely finished before validating a
volume, otherwise referenced raid stripes may not have pv
data applied yet

Signed-off-by: Patrick Plenefisch <simonpatp@gmail.com>
---
 grub-core/disk/diskfilter.c |  6 ++-
 grub-core/disk/lvm.c        | 83 +++++++++++++++++++++++--------------
 2 files changed, 56 insertions(+), 33 deletions(-)

diff --git a/grub-core/disk/diskfilter.c b/grub-core/disk/diskfilter.c
index 21e239511..dc3bd943b 100644
--- a/grub-core/disk/diskfilter.c
+++ b/grub-core/disk/diskfilter.c
@@ -966,8 +966,6 @@ grub_diskfilter_vg_register (struct grub_diskfilter_vg *vg)

   for (lv = vg->lvs; lv; lv = lv->next)
     {
-      grub_err_t err;
-
       /* RAID 1 and single-disk RAID 0 don't use a chunksize but code
          assumes one so set one. */
       for (i = 0; i < lv->segment_count; i++)
@@ -979,6 +977,10 @@ grub_diskfilter_vg_register (struct grub_diskfilter_vg *vg)
       && lv->segments[i].stripe_size == 0)
     lv->segments[i].stripe_size = 64;
  }
+    }
+  for (lv = vg->lvs; lv; lv = lv->next)
+    {
+      grub_err_t err;

       err = validate_lv(lv);
       if (err)
diff --git a/grub-core/disk/lvm.c b/grub-core/disk/lvm.c
index 10bc965a4..7615a507a 100644
--- a/grub-core/disk/lvm.c
+++ b/grub-core/disk/lvm.c
@@ -805,13 +805,27 @@ grub_lvm_detect (grub_disk_t disk,
   seg->nodes[seg->node_count - 1].name = tmp;
  }
     }
+  /* Cache and integrity LVs have extra parts that
+     we can ignore for our read-only access */
   else if (grub_memcmp (p, "cache\"",
-   sizeof ("cache\"") - 1) == 0)
+   sizeof ("cache\"") - 1) == 0
+   || grub_memcmp (p, "cache+CACHE_USES_CACHEVOL\"",
+   sizeof ("cache+CACHE_USES_CACHEVOL\"") - 1) == 0
+   || grub_memcmp (p, "integrity\"",
+   sizeof ("integrity\"") - 1) == 0)
     {
       struct ignored_feature_lv *ignored_feature = NULL;

       char *p2, *p3;
       grub_size_t sz;
+#ifdef GRUB_UTIL
+      p2 = grub_strchr (p, '"');
+      if (p2)
+ *p2 = 0;
+      grub_util_info ("Ignoring extra metadata type '%s' for %s", p, lv->name);
+      if (p2)
+ *p2 ='"';
+#endif

       ignored_feature = grub_zalloc (sizeof (*ignored_feature));
       if (!ignored_feature)
@@ -936,36 +950,6 @@ grub_lvm_detect (grub_disk_t disk,
     }
  }

-      /* Match lvs.  */
-      {
- struct grub_diskfilter_lv *lv1;
- struct grub_diskfilter_lv *lv2;
- for (lv1 = vg->lvs; lv1; lv1 = lv1->next)
-  for (i = 0; i < lv1->segment_count; i++)
-    for (j = 0; j < lv1->segments[i].node_count; j++)
-      {
- if (vg->pvs)
-  for (pv = vg->pvs; pv; pv = pv->next)
-    {
-      if (! grub_strcmp (pv->name,
- lv1->segments[i].nodes[j].name))
- {
-  lv1->segments[i].nodes[j].pv = pv;
-  break;
- }
-    }
- if (lv1->segments[i].nodes[j].pv == NULL)
-  for (lv2 = vg->lvs; lv2; lv2 = lv2->next)
-    {
-      if (lv1 == lv2)
-        continue;
-      if (grub_strcmp (lv2->name,
-       lv1->segments[i].nodes[j].name) == 0)
- lv1->segments[i].nodes[j].lv = lv2;
-    }
-      }
-
-      }

       {
  struct ignored_feature_lv *ignored_feature;
@@ -1014,9 +998,46 @@ grub_lvm_detect (grub_disk_t disk,
     ignored_feature->lv = NULL;
   }
       }
+  else
+  {
+
+#ifdef GRUB_UTIL
+      grub_util_info ("Couldn't find LVM part of ignored feature on
%s", ignored_feature->origin);
+#endif
+  }
   }
       }

+      /* Match lvs. Must be done after cache and integrity are found  */
+      {
+ struct grub_diskfilter_lv *lv1;
+ struct grub_diskfilter_lv *lv2;
+ for (lv1 = vg->lvs; lv1; lv1 = lv1->next)
+  for (i = 0; i < lv1->segment_count; i++)
+    for (j = 0; j < lv1->segments[i].node_count; j++)
+      {
+ if (vg->pvs)
+  for (pv = vg->pvs; pv; pv = pv->next)
+    {
+      if (! grub_strcmp (pv->name,
+ lv1->segments[i].nodes[j].name))
+ {
+  lv1->segments[i].nodes[j].pv = pv;
+  break;
+ }
+    }
+ if (lv1->segments[i].nodes[j].pv == NULL)
+  for (lv2 = vg->lvs; lv2; lv2 = lv2->next)
+    {
+      if (lv1 == lv2)
+        continue;
+      if (grub_strcmp (lv2->name,
+       lv1->segments[i].nodes[j].name) == 0)
+ lv1->segments[i].nodes[j].lv = lv2;
+    }
+      }
+      }
+
   grub_lvm_free_ignored_feature_lvs (ignored_feature_lvs);
       if (grub_diskfilter_vg_register (vg))
  goto fail4;
-- 
2.39.2

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