use-non-moveable-memory-for-the-ext4-superblock

   1 ext4: use non-movable memory for the ext4 superblock
   2
   3 From: Gioh Kim <gioh.kim@lge.com>
   4
   5 Since the ext4 superblock is not released until the file system is
   6 unmounted, allocate the buffer cache entry for the ext4 superblock out
   7 of the non-moveable are to allow page migrations and thus CMA
   8 allocations to more easily succeed if the CMA area is limited.
   9
  10 Signed-off-by: Gioh Kim <gioh.kim@lge.com>
  11 Signed-off-by: Theodore Ts'o <tytso@mit.edu>
  12 Reviewed-by: Jan Kara <jack@suse.cz>
  13 ---
  14  fs/ext4/super.c | 6 +++---
  15  1 file changed, 3 insertions(+), 3 deletions(-)
  16
  17 diff --git a/fs/ext4/super.c b/fs/ext4/super.c
  18 index 487c65b..4b81747 100644
  19 --- a/fs/ext4/super.c
  20 +++ b/fs/ext4/super.c
  21 @@ -3436,7 +3436,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
  22                 logical_sb_block = sb_block;
  23         }
  24
  25 -       if (!(bh = sb_bread(sb, logical_sb_block))) {
  26 +       if (!(bh = sb_bread_unmovable(sb, logical_sb_block))) {
  27                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
  28                 goto out_fail;
  29         }
  30 @@ -3646,7 +3646,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
  31                 brelse(bh);
  32                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
  33                 offset = do_div(logical_sb_block, blocksize);
  34 -               bh = sb_bread(sb, logical_sb_block);
  35 +               bh = sb_bread_unmovable(sb, logical_sb_block);
  36                 if (!bh) {
  37                         ext4_msg(sb, KERN_ERR,
  38                                "Can't read superblock on 2nd try");
  39 @@ -3868,7 +3868,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
  40
  41         for (i = 0; i < db_count; i++) {
  42                 block = descriptor_loc(sb, logical_sb_block, i);
  43 -               sbi->s_group_desc[i] = sb_bread(sb, block);
  44 +               sbi->s_group_desc[i] = sb_bread_unmovable(sb, block);
  45                 if (!sbi->s_group_desc[i]) {
  46                         ext4_msg(sb, KERN_ERR,
  47                                "can't read group descriptor %d", i);