From a8ac900b8163703340a2fdad11c32f96b8fe686d Mon Sep 17 00:00:00 2001
From: Gioh Kim <gioh.kim@lge.com>
Date: Thu, 4 Sep 2014 22:36:15 -0400
Subject: ext4: use non-movable memory for the ext4 superblock

Since the ext4 superblock is not released until the file system is
unmounted, allocate the buffer cache entry for the ext4 superblock out
of the non-moveable are to allow page migrations and thus CMA
allocations to more easily succeed if the CMA area is limited.

Signed-off-by: Gioh Kim <gioh.kim@lge.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 487c65b..4b81747 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3436,7 +3436,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 		logical_sb_block = sb_block;
 	}
 
-	if (!(bh = sb_bread(sb, logical_sb_block))) {
+	if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
 		ext4_msg(sb, KERN_ERR, "unable to read superblock");
 		goto out_fail;
 	}
@@ -3646,7 +3646,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 		brelse(bh);
 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
 		offset = do_div(logical_sb_block, blocksize);
-		bh = sb_bread(sb, logical_sb_block);
+		bh = sb_bread_unmovable(sb, logical_sb_block);
 		if (!bh) {
 			ext4_msg(sb, KERN_ERR,
 			       "Can't read superblock on 2nd try");
@@ -3868,7 +3868,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 
 	for (i = 0; i < db_count; i++) {
 		block = descriptor_loc(sb, logical_sb_block, i);
-		sbi->s_group_desc[i] = sb_bread(sb, block);
+		sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
 		if (!sbi->s_group_desc[i]) {
 			ext4_msg(sb, KERN_ERR,
 			       "can't read group descriptor %d", i);
-- 
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