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-rw-r--r--fs/ocfs2/buffer_head_io.c61
1 files changed, 61 insertions, 0 deletions
diff --git a/fs/ocfs2/buffer_head_io.c b/fs/ocfs2/buffer_head_io.c
index c9037414f4f6..31aa61dc777b 100644
--- 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;
+}