[PATCH] UBI: bugfix: allocate mandatory EBs first

[Artem Bityutskiy <dedekind@infradead.org>]

Linus,

please, apply the below UBI bugfix. The patch is quite trivial and fixes
an unpleasant UBI bug when it cannot attach an MTD device because it
first reserves the bad block handling pool (not mandatory), and then
tries to reserve a mandatory PEB. It should be vice versa.

From: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Subject: [PATCH] UBI: bugfix: allocate mandatory EBs first

First allocate the necessary eraseblocks, then the optional ones.
Otherwise it allocates all PEBs for bad EB handling, and fails
on then following EBA LEB allocation.

Reported-by: Adrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
---
 drivers/mtd/ubi/eba.c |   18 +++++++++---------
 1 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/mtd/ubi/eba.c b/drivers/mtd/ubi/eba.c
index 880fa36..85f50c8 100644
--- a/drivers/mtd/ubi/eba.c
+++ b/drivers/mtd/ubi/eba.c
@@ -1168,6 +1168,15 @@ int ubi_eba_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si)
 		}
 	}
 
+	if (ubi->avail_pebs < EBA_RESERVED_PEBS) {
+		ubi_err("no enough physical eraseblocks (%d, need %d)",
+			ubi->avail_pebs, EBA_RESERVED_PEBS);
+		err = -ENOSPC;
+		goto out_free;
+	}
+	ubi->avail_pebs -= EBA_RESERVED_PEBS;
+	ubi->rsvd_pebs += EBA_RESERVED_PEBS;
+
 	if (ubi->bad_allowed) {
 		ubi_calculate_reserved(ubi);
 
@@ -1184,15 +1193,6 @@ int ubi_eba_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si)
 		ubi->rsvd_pebs  += ubi->beb_rsvd_pebs;
 	}
 
-	if (ubi->avail_pebs < EBA_RESERVED_PEBS) {
-		ubi_err("no enough physical eraseblocks (%d, need %d)",
-			ubi->avail_pebs, EBA_RESERVED_PEBS);
-		err = -ENOSPC;
-		goto out_free;
-	}
-	ubi->avail_pebs -= EBA_RESERVED_PEBS;
-	ubi->rsvd_pebs += EBA_RESERVED_PEBS;
-
 	dbg_eba("EBA unit is initialized");
 	return 0;
 
-- 
1.5.2.4