xfs: refactor log recovery BUI item dispatch for pass2 commit functions

Move the bmap update intent and intent-done pass2 commit code into the
per-item source code files and use dispatch functions to call them.  We
do these one at a time because there's a lot of code to move.  No
functional changes.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
diff --git a/fs/xfs/xfs_bmap_item.c b/fs/xfs/xfs_bmap_item.c
index 508b48c..1537759 100644
--- a/fs/xfs/xfs_bmap_item.c
+++ b/fs/xfs/xfs_bmap_item.c
@@ -22,6 +22,7 @@
 #include "xfs_bmap_btree.h"
 #include "xfs_trans_space.h"
 #include "xfs_error.h"
+#include "xfs_log_priv.h"
 #include "xfs_log_recover.h"
 
 kmem_zone_t	*xfs_bui_zone;
@@ -32,7 +33,7 @@ static inline struct xfs_bui_log_item *BUI_ITEM(struct xfs_log_item *lip)
 	return container_of(lip, struct xfs_bui_log_item, bui_item);
 }
 
-void
+STATIC void
 xfs_bui_item_free(
 	struct xfs_bui_log_item	*buip)
 {
@@ -135,7 +136,7 @@ static const struct xfs_item_ops xfs_bui_item_ops = {
 /*
  * Allocate and initialize an bui item with the given number of extents.
  */
-struct xfs_bui_log_item *
+STATIC struct xfs_bui_log_item *
 xfs_bui_init(
 	struct xfs_mount		*mp)
 
@@ -559,10 +560,138 @@ xfs_bui_recover(
 	return error;
 }
 
+/*
+ * 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;
+	}
+	XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, NULL);
+	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_commit_pass2(
+	struct xlog			*log,
+	struct list_head		*buffer_list,
+	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) {
+		XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, log->l_mp);
+		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->ail_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;
+}
+
 const struct xlog_recover_item_ops xlog_bui_item_ops = {
 	.item_type		= XFS_LI_BUI,
+	.commit_pass2		= xlog_recover_bui_commit_pass2,
 };
 
+/*
+ * 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_commit_pass2(
+	struct xlog			*log,
+	struct list_head		*buffer_list,
+	struct xlog_recover_item	*item,
+	xfs_lsn_t			lsn)
+{
+	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)) {
+		XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, log->l_mp);
+		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->ail_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->ail_lock);
+				xfs_bui_release(buip);
+				spin_lock(&ailp->ail_lock);
+				break;
+			}
+		}
+		lip = xfs_trans_ail_cursor_next(ailp, &cur);
+	}
+
+	xfs_trans_ail_cursor_done(&cur);
+	spin_unlock(&ailp->ail_lock);
+
+	return 0;
+}
+
 const struct xlog_recover_item_ops xlog_bud_item_ops = {
 	.item_type		= XFS_LI_BUD,
+	.commit_pass2		= xlog_recover_bud_commit_pass2,
 };