[PATCH 1/2] ocfs2: Add group extend for online resize

[pandora-kernel.git] / fs / ocfs2 / buffer_head_io.c

diff --git a/fs/ocfs2/buffer_head_io.c b/fs/ocfs2/buffer_head_io.c
index c903741..31aa61d 100644 (file)
--- a/fs/ocfs2/buffer_head_io.c
+++ b/fs/ocfs2/buffer_head_io.c
@@ -280,3 +280,64 @@ bail:
        mlog_exit(status);
        return status;
 }
+
+/* Check whether the blkno is the super block or one of the backups. */
+static void ocfs2_check_super_or_backup(struct super_block *sb,
+                                       sector_t blkno)
+{
+       int i;
+       u64 backup_blkno;
+
+       if (blkno == OCFS2_SUPER_BLOCK_BLKNO)
+               return;
+
+       for (i = 0; i < OCFS2_MAX_BACKUP_SUPERBLOCKS; i++) {
+               backup_blkno = ocfs2_backup_super_blkno(sb, i);
+               if (backup_blkno == blkno)
+                       return;
+       }
+
+       BUG();
+}
+
+/*
+ * Write super block and backups doesn't need to collaborate with journal,
+ * so we don't need to lock ip_io_mutex and inode doesn't need to bea passed
+ * into this function.
+ */
+int ocfs2_write_super_or_backup(struct ocfs2_super *osb,
+                               struct buffer_head *bh)
+{
+       int ret = 0;
+
+       mlog_entry_void();
+
+       BUG_ON(buffer_jbd(bh));
+       ocfs2_check_super_or_backup(osb->sb, bh->b_blocknr);
+
+       if (ocfs2_is_hard_readonly(osb) || ocfs2_is_soft_readonly(osb)) {
+               ret = -EROFS;
+               goto out;
+       }
+
+       lock_buffer(bh);
+       set_buffer_uptodate(bh);
+
+       /* remove from dirty list before I/O. */
+       clear_buffer_dirty(bh);
+
+       get_bh(bh); /* for end_buffer_write_sync() */
+       bh->b_end_io = end_buffer_write_sync;
+       submit_bh(WRITE, bh);
+
+       wait_on_buffer(bh);
+
+       if (!buffer_uptodate(bh)) {
+               ret = -EIO;
+               brelse(bh);
+       }
+
+out:
+       mlog_exit(ret);
+       return ret;
+}