ext4: fix race when setting bitmap_uptodate flag

[mirror_ubuntu-bionic-kernel.git] / fs / ext4 / ialloc.c

diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index 84e6e9a3986b65ea0f7d65882ab9acced4c69613..b2685992fb2d2a54cdb8e8b6967a5fe604d7afa0 100644 (file)
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -92,6 +92,16 @@ static unsigned ext4_init_inode_bitmap(struct super_block *sb,
        return EXT4_INODES_PER_GROUP(sb);
 }
 
+void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate)
+{
+       if (uptodate) {
+               set_buffer_uptodate(bh);
+               set_bitmap_uptodate(bh);
+       }
+       unlock_buffer(bh);
+       put_bh(bh);
+}
+
 /*
  * Read the inode allocation bitmap for a given block_group, reading
  * into the specified slot in the superblock's bitmap cache.
@@ -147,18 +157,18 @@ ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
                return bh;
        }
        /*
-        * submit the buffer_head for read. We can
-        * safely mark the bitmap as uptodate now.
-        * We do it here so the bitmap uptodate bit
-        * get set with buffer lock held.
+        * submit the buffer_head for reading
         */
        trace_ext4_load_inode_bitmap(sb, block_group);
-       set_bitmap_uptodate(bh);
-       if (bh_submit_read(bh) < 0) {
+       bh->b_end_io = ext4_end_bitmap_read;
+       get_bh(bh);
+       submit_bh(READ, bh);
+       wait_on_buffer(bh);
+       if (!buffer_uptodate(bh)) {
                put_bh(bh);
                ext4_error(sb, "Cannot read inode bitmap - "
-                           "block_group = %u, inode_bitmap = %llu",
-                           block_group, bitmap_blk);
+                          "block_group = %u, inode_bitmap = %llu",
+                          block_group, bitmap_blk);
                return NULL;
        }
        return bh;