xfs: log bmap intent items

Provide a mechanism for higher levels to create BUI/BUD items, submit
them to the log, and a stub function to deal with recovered BUI items.
These parts will be connected to the rmapbt in a later patch.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
index 622881a..9697e94 100644
--- a/fs/xfs/xfs_log_recover.c
+++ b/fs/xfs/xfs_log_recover.c
@@ -46,6 +46,7 @@
 #include "xfs_rmap_item.h"
 #include "xfs_buf_item.h"
 #include "xfs_refcount_item.h"
+#include "xfs_bmap_item.h"
 
 #define BLK_AVG(blk1, blk2)	((blk1+blk2) >> 1)
 
@@ -1927,6 +1928,8 @@
 		case XFS_LI_RUD:
 		case XFS_LI_CUI:
 		case XFS_LI_CUD:
+		case XFS_LI_BUI:
+		case XFS_LI_BUD:
 			trace_xfs_log_recover_item_reorder_tail(log,
 							trans, item, pass);
 			list_move_tail(&item->ri_list, &inode_list);
@@ -3671,6 +3674,125 @@
 }
 
 /*
+ * Copy an BUI format buffer from the given buf, and into the destination
+ * BUI format structure.  The BUI/BUD items were designed not to need any
+ * special alignment handling.
+ */
+static int
+xfs_bui_copy_format(
+	struct xfs_log_iovec		*buf,
+	struct xfs_bui_log_format	*dst_bui_fmt)
+{
+	struct xfs_bui_log_format	*src_bui_fmt;
+	uint				len;
+
+	src_bui_fmt = buf->i_addr;
+	len = xfs_bui_log_format_sizeof(src_bui_fmt->bui_nextents);
+
+	if (buf->i_len == len) {
+		memcpy(dst_bui_fmt, src_bui_fmt, len);
+		return 0;
+	}
+	return -EFSCORRUPTED;
+}
+
+/*
+ * This routine is called to create an in-core extent bmap update
+ * item from the bui format structure which was logged on disk.
+ * It allocates an in-core bui, copies the extents from the format
+ * structure into it, and adds the bui to the AIL with the given
+ * LSN.
+ */
+STATIC int
+xlog_recover_bui_pass2(
+	struct xlog			*log,
+	struct xlog_recover_item	*item,
+	xfs_lsn_t			lsn)
+{
+	int				error;
+	struct xfs_mount		*mp = log->l_mp;
+	struct xfs_bui_log_item		*buip;
+	struct xfs_bui_log_format	*bui_formatp;
+
+	bui_formatp = item->ri_buf[0].i_addr;
+
+	if (bui_formatp->bui_nextents != XFS_BUI_MAX_FAST_EXTENTS)
+		return -EFSCORRUPTED;
+	buip = xfs_bui_init(mp);
+	error = xfs_bui_copy_format(&item->ri_buf[0], &buip->bui_format);
+	if (error) {
+		xfs_bui_item_free(buip);
+		return error;
+	}
+	atomic_set(&buip->bui_next_extent, bui_formatp->bui_nextents);
+
+	spin_lock(&log->l_ailp->xa_lock);
+	/*
+	 * The RUI has two references. One for the RUD and one for RUI to ensure
+	 * it makes it into the AIL. Insert the RUI into the AIL directly and
+	 * drop the RUI reference. Note that xfs_trans_ail_update() drops the
+	 * AIL lock.
+	 */
+	xfs_trans_ail_update(log->l_ailp, &buip->bui_item, lsn);
+	xfs_bui_release(buip);
+	return 0;
+}
+
+
+/*
+ * This routine is called when an BUD format structure is found in a committed
+ * transaction in the log. Its purpose is to cancel the corresponding BUI if it
+ * was still in the log. To do this it searches the AIL for the BUI with an id
+ * equal to that in the BUD format structure. If we find it we drop the BUD
+ * reference, which removes the BUI from the AIL and frees it.
+ */
+STATIC int
+xlog_recover_bud_pass2(
+	struct xlog			*log,
+	struct xlog_recover_item	*item)
+{
+	struct xfs_bud_log_format	*bud_formatp;
+	struct xfs_bui_log_item		*buip = NULL;
+	struct xfs_log_item		*lip;
+	__uint64_t			bui_id;
+	struct xfs_ail_cursor		cur;
+	struct xfs_ail			*ailp = log->l_ailp;
+
+	bud_formatp = item->ri_buf[0].i_addr;
+	if (item->ri_buf[0].i_len != sizeof(struct xfs_bud_log_format))
+		return -EFSCORRUPTED;
+	bui_id = bud_formatp->bud_bui_id;
+
+	/*
+	 * Search for the BUI with the id in the BUD format structure in the
+	 * AIL.
+	 */
+	spin_lock(&ailp->xa_lock);
+	lip = xfs_trans_ail_cursor_first(ailp, &cur, 0);
+	while (lip != NULL) {
+		if (lip->li_type == XFS_LI_BUI) {
+			buip = (struct xfs_bui_log_item *)lip;
+			if (buip->bui_format.bui_id == bui_id) {
+				/*
+				 * Drop the BUD reference to the BUI. This
+				 * removes the BUI from the AIL and frees it.
+				 */
+				spin_unlock(&ailp->xa_lock);
+				xfs_bui_release(buip);
+				spin_lock(&ailp->xa_lock);
+				break;
+			}
+		}
+		lip = xfs_trans_ail_cursor_next(ailp, &cur);
+	}
+
+	xfs_trans_ail_cursor_done(&cur);
+	spin_unlock(&ailp->xa_lock);
+
+	return 0;
+}
+
+/*
  * This routine is called when an inode create format structure is found in a
  * committed transaction in the log.  It's purpose is to initialise the inodes
  * being allocated on disk. This requires us to get inode cluster buffers that
@@ -3899,6 +4021,8 @@
 	case XFS_LI_RUD:
 	case XFS_LI_CUI:
 	case XFS_LI_CUD:
+	case XFS_LI_BUI:
+	case XFS_LI_BUD:
 	default:
 		break;
 	}
@@ -3926,6 +4050,8 @@
 	case XFS_LI_RUD:
 	case XFS_LI_CUI:
 	case XFS_LI_CUD:
+	case XFS_LI_BUI:
+	case XFS_LI_BUD:
 		/* nothing to do in pass 1 */
 		return 0;
 	default:
@@ -3964,6 +4090,10 @@
 		return xlog_recover_cui_pass2(log, item, trans->r_lsn);
 	case XFS_LI_CUD:
 		return xlog_recover_cud_pass2(log, item);
+	case XFS_LI_BUI:
+		return xlog_recover_bui_pass2(log, item, trans->r_lsn);
+	case XFS_LI_BUD:
+		return xlog_recover_bud_pass2(log, item);
 	case XFS_LI_DQUOT:
 		return xlog_recover_dquot_pass2(log, buffer_list, item,
 						trans->r_lsn);
@@ -4591,6 +4721,46 @@
 	spin_lock(&ailp->xa_lock);
 }
 
+/* Recover the BUI if necessary. */
+STATIC int
+xlog_recover_process_bui(
+	struct xfs_mount		*mp,
+	struct xfs_ail			*ailp,
+	struct xfs_log_item		*lip)
+{
+	struct xfs_bui_log_item		*buip;
+	int				error;
+
+	/*
+	 * Skip BUIs that we've already processed.
+	 */
+	buip = container_of(lip, struct xfs_bui_log_item, bui_item);
+	if (test_bit(XFS_BUI_RECOVERED, &buip->bui_flags))
+		return 0;
+
+	spin_unlock(&ailp->xa_lock);
+	error = xfs_bui_recover(mp, buip);
+	spin_lock(&ailp->xa_lock);
+
+	return error;
+}
+
+/* Release the BUI since we're cancelling everything. */
+STATIC void
+xlog_recover_cancel_bui(
+	struct xfs_mount		*mp,
+	struct xfs_ail			*ailp,
+	struct xfs_log_item		*lip)
+{
+	struct xfs_bui_log_item		*buip;
+
+	buip = container_of(lip, struct xfs_bui_log_item, bui_item);
+
+	spin_unlock(&ailp->xa_lock);
+	xfs_bui_release(buip);
+	spin_lock(&ailp->xa_lock);
+}
+
 /* Is this log item a deferred action intent? */
 static inline bool xlog_item_is_intent(struct xfs_log_item *lip)
 {
@@ -4598,6 +4768,7 @@
 	case XFS_LI_EFI:
 	case XFS_LI_RUI:
 	case XFS_LI_CUI:
+	case XFS_LI_BUI:
 		return true;
 	default:
 		return false;
@@ -4664,6 +4835,9 @@
 		case XFS_LI_CUI:
 			error = xlog_recover_process_cui(log->l_mp, ailp, lip);
 			break;
+		case XFS_LI_BUI:
+			error = xlog_recover_process_bui(log->l_mp, ailp, lip);
+			break;
 		}
 		if (error)
 			goto out;
@@ -4714,6 +4888,9 @@
 		case XFS_LI_CUI:
 			xlog_recover_cancel_cui(log->l_mp, ailp, lip);
 			break;
+		case XFS_LI_BUI:
+			xlog_recover_cancel_bui(log->l_mp, ailp, lip);
+			break;
 		}
 
 		lip = xfs_trans_ail_cursor_next(ailp, &cur);