Re: [PATCH 2/8] imsm: write bad block log on metadata sync

Pre-allocate memory for largest possible bad block sectionwhen monitor
is being opened to avoid a need for memory allocation on metadata sync.

If memory for a structure has been allocated in mpb buffer but it hasn't
been used yet, it will be taken by next buffer grow, leading to
insufficient memory on metadata flush. Start tracking such memory and
take it into calculation when growing a buffer. Also assert has been
added to debug mode to warn when more metadata has been written than
memory allocated.

Signed-off-by: Tomasz Majchrzak <redacted>
---
 super-intel.c | 49 +++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 45 insertions(+), 4 deletions(-)

diff --git a/super-intel.c b/super-intel.c
index 5d6d534..0591c55 100644
--- a/super-intel.c
+++ b/super-intel.c

@@ -8854,6 +8886,9 @@ static void imsm_process_update(struct supertype *st,
 		}
 		break;
 	}
+	case update_prealloc_badblocks_mem: {
+		break;
+	}
 	default:
 		pr_err("error: unsuported process update type:(type: %d)\n",	type);
 	}

@@ -9094,6 +9129,11 @@ static int imsm_prepare_update(struct supertype *st,
 	case update_add_remove_disk:
 		/* no update->len needed */
 		break;
+	case update_prealloc_badblocks_mem: {
+		super->extra_space += sizeof(struct bbm_log) -
+			get_imsm_bbm_log_size(super->bbm_log);
+		break;
+	}
 	default:
 		return 0;
 	}