ext4: validate s_reserved_gdt_blocks on mount

[mirror_ubuntu-artful-kernel.git] / fs / ext4 / balloc.c

diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index 3020fd70c392d1f2b55913e374ed11831b2aa967..799a92bdf57785389d57d8aae3e66dc473078039 100644 (file)
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -208,6 +208,9 @@ static int ext4_init_block_bitmap(struct super_block *sb,
        memset(bh->b_data, 0, sb->s_blocksize);
 
        bit_max = ext4_num_base_meta_clusters(sb, block_group);
+       if ((bit_max >> 3) >= bh->b_size)
+               return -EFSCORRUPTED;
+
        for (bit = 0; bit < bit_max; bit++)
                ext4_set_bit(bit, bh->b_data);
 
@@ -610,7 +613,9 @@ int ext4_should_retry_alloc(struct super_block *sb, int *retries)
 
        jbd_debug(1, "%s: retrying operation after ENOSPC\n", sb->s_id);
 
-       jbd2_journal_force_commit_nested(EXT4_SB(sb)->s_journal);
+       smp_mb();
+       if (EXT4_SB(sb)->s_mb_free_pending)
+               jbd2_journal_force_commit_nested(EXT4_SB(sb)->s_journal);
        return 1;
 }