xfs: refactor log recovery item sorting into a generic dispatch structure

Create a generic dispatch structure to delegate recovery of different
log item types into various code modules.  This will enable us to move
code specific to a particular log item type out of xfs_log_recover.c and
into the log item source.

The first operation we virtualize is the log item sorting.
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>

fs/xfs/Makefile

@@ -99,9 +99,12 @@ xfs-y				+= xfs_log.o \
 				   xfs_log_cil.o \
 				   xfs_bmap_item.o \
 				   xfs_buf_item.o \
+				   xfs_buf_item_recover.o \
+				   xfs_dquot_item_recover.o \
 				   xfs_extfree_item.o \
 				   xfs_icreate_item.o \
 				   xfs_inode_item.o \
+				   xfs_inode_item_recover.o \
 				   xfs_refcount_item.o \
 				   xfs_rmap_item.o \
 				   xfs_log_recover.o \

fs/xfs/libxfs/xfs_log_recover.h

@@ -6,6 +6,47 @@
 #ifndef	__XFS_LOG_RECOVER_H__
 #define __XFS_LOG_RECOVER_H__
 
+/*
+ * Each log item type (XFS_LI_*) gets its own xlog_recover_item_ops to
+ * define how recovery should work for that type of log item.
+ */
+struct xlog_recover_item;
+
+/* Sorting hat for log items as they're read in. */
+enum xlog_recover_reorder {
+	XLOG_REORDER_BUFFER_LIST,
+	XLOG_REORDER_ITEM_LIST,
+	XLOG_REORDER_INODE_BUFFER_LIST,
+	XLOG_REORDER_CANCEL_LIST,
+};
+
+struct xlog_recover_item_ops {
+	uint16_t	item_type;	/* XFS_LI_* type code. */
+
+	/*
+	 * Help sort recovered log items into the order required to replay them
+	 * correctly.  Log item types that always use XLOG_REORDER_ITEM_LIST do
+	 * not have to supply a function here.  See the comment preceding
+	 * xlog_recover_reorder_trans for more details about what the return
+	 * values mean.
+	 */
+	enum xlog_recover_reorder (*reorder)(struct xlog_recover_item *item);
+};
+
+extern const struct xlog_recover_item_ops xlog_icreate_item_ops;
+extern const struct xlog_recover_item_ops xlog_buf_item_ops;
+extern const struct xlog_recover_item_ops xlog_inode_item_ops;
+extern const struct xlog_recover_item_ops xlog_dquot_item_ops;
+extern const struct xlog_recover_item_ops xlog_quotaoff_item_ops;
+extern const struct xlog_recover_item_ops xlog_bui_item_ops;
+extern const struct xlog_recover_item_ops xlog_bud_item_ops;
+extern const struct xlog_recover_item_ops xlog_efi_item_ops;
+extern const struct xlog_recover_item_ops xlog_efd_item_ops;
+extern const struct xlog_recover_item_ops xlog_rui_item_ops;
+extern const struct xlog_recover_item_ops xlog_rud_item_ops;
+extern const struct xlog_recover_item_ops xlog_cui_item_ops;
+extern const struct xlog_recover_item_ops xlog_cud_item_ops;
+
 /*
  * Macros, structures, prototypes for internal log manager use.
  */
@@ -24,10 +65,10 @@
  */
 struct xlog_recover_item {
 	struct list_head	ri_list;
-	int			ri_type;
 	int			ri_cnt;	/* count of regions found */
 	int			ri_total;	/* total regions */
-	xfs_log_iovec_t		*ri_buf;	/* ptr to regions buffer */
+	struct xfs_log_iovec	*ri_buf;	/* ptr to regions buffer */
+	const struct xlog_recover_item_ops *ri_ops;
 };
 
 struct xlog_recover {

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_recover.h"
 
 kmem_zone_t	*xfs_bui_zone;
 kmem_zone_t	*xfs_bud_zone;
@@ -557,3 +558,11 @@ xfs_bui_recover(
 	}
 	return error;
 }
+
+const struct xlog_recover_item_ops xlog_bui_item_ops = {
+	.item_type		= XFS_LI_BUI,
+};
+
+const struct xlog_recover_item_ops xlog_bud_item_ops = {
+	.item_type		= XFS_LI_BUD,
+};

fs/xfs/xfs_buf_item_recover.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2000-2006 Silicon Graphics, Inc.
+ * All Rights Reserved.
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_log_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_bit.h"
+#include "xfs_mount.h"
+#include "xfs_trans.h"
+#include "xfs_buf_item.h"
+#include "xfs_trans_priv.h"
+#include "xfs_trace.h"
+#include "xfs_log.h"
+#include "xfs_log_priv.h"
+#include "xfs_log_recover.h"
+
+/*
+ * Sort buffer items for log recovery.  Most buffer items should end up on the
+ * buffer list and are recovered first, with the following exceptions:
+ *
+ * 1. XFS_BLF_CANCEL buffers must be processed last because some log items
+ *    might depend on the incor ecancellation record, and replaying a cancelled
+ *    buffer item can remove the incore record.
+ *
+ * 2. XFS_BLF_INODE_BUF buffers are handled after most regular items so that
+ *    we replay di_next_unlinked only after flushing the inode 'free' state
+ *    to the inode buffer.
+ *
+ * See xlog_recover_reorder_trans for more details.
+ */
+STATIC enum xlog_recover_reorder
+xlog_recover_buf_reorder(
+	struct xlog_recover_item	*item)
+{
+	struct xfs_buf_log_format	*buf_f = item->ri_buf[0].i_addr;
+
+	if (buf_f->blf_flags & XFS_BLF_CANCEL)
+		return XLOG_REORDER_CANCEL_LIST;
+	if (buf_f->blf_flags & XFS_BLF_INODE_BUF)
+		return XLOG_REORDER_INODE_BUFFER_LIST;
+	return XLOG_REORDER_BUFFER_LIST;
+}
+
+const struct xlog_recover_item_ops xlog_buf_item_ops = {
+	.item_type		= XFS_LI_BUF,
+	.reorder		= xlog_recover_buf_reorder,
+};

fs/xfs/xfs_dquot_item_recover.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2000-2006 Silicon Graphics, Inc.
+ * All Rights Reserved.
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_log_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_inode.h"
+#include "xfs_quota.h"
+#include "xfs_trans.h"
+#include "xfs_buf_item.h"
+#include "xfs_trans_priv.h"
+#include "xfs_qm.h"
+#include "xfs_log.h"
+#include "xfs_log_priv.h"
+#include "xfs_log_recover.h"
+
+const struct xlog_recover_item_ops xlog_dquot_item_ops = {
+	.item_type		= XFS_LI_DQUOT,
+};
+
+const struct xlog_recover_item_ops xlog_quotaoff_item_ops = {
+	.item_type		= XFS_LI_QUOTAOFF,
+};

fs/xfs/xfs_extfree_item.c

@@ -22,6 +22,7 @@
 #include "xfs_bmap.h"
 #include "xfs_trace.h"
 #include "xfs_error.h"
+#include "xfs_log_recover.h"
 
 kmem_zone_t	*xfs_efi_zone;
 kmem_zone_t	*xfs_efd_zone;
@@ -644,3 +645,11 @@ xfs_efi_recover(
 	xfs_trans_cancel(tp);
 	return error;
 }
+
+const struct xlog_recover_item_ops xlog_efi_item_ops = {
+	.item_type		= XFS_LI_EFI,
+};
+
+const struct xlog_recover_item_ops xlog_efd_item_ops = {
+	.item_type		= XFS_LI_EFD,
+};

fs/xfs/xfs_icreate_item.c

@@ -11,6 +11,8 @@
 #include "xfs_trans_priv.h"
 #include "xfs_icreate_item.h"
 #include "xfs_log.h"
+#include "xfs_log_priv.h"
+#include "xfs_log_recover.h"
 
 kmem_zone_t	*xfs_icreate_zone;		/* inode create item zone */
 
@@ -107,3 +109,21 @@ xfs_icreate_log(
 	tp->t_flags |= XFS_TRANS_DIRTY;
 	set_bit(XFS_LI_DIRTY, &icp->ic_item.li_flags);
 }
+
+static enum xlog_recover_reorder
+xlog_recover_icreate_reorder(
+		struct xlog_recover_item *item)
+{
+	/*
+	 * Inode allocation buffers must be replayed before subsequent inode
+	 * items try to modify those buffers.  ICREATE items are the logical
+	 * equivalent of logging a newly initialized inode buffer, so recover
+	 * these at the same time that we recover logged buffers.
+	 */
+	return XLOG_REORDER_BUFFER_LIST;
+}
+
+const struct xlog_recover_item_ops xlog_icreate_item_ops = {
+	.item_type		= XFS_LI_ICREATE,
+	.reorder		= xlog_recover_icreate_reorder,
+};

fs/xfs/xfs_inode_item_recover.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2000-2006 Silicon Graphics, Inc.
+ * All Rights Reserved.
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_log_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_inode.h"
+#include "xfs_trans.h"
+#include "xfs_inode_item.h"
+#include "xfs_trace.h"
+#include "xfs_trans_priv.h"
+#include "xfs_buf_item.h"
+#include "xfs_log.h"
+#include "xfs_error.h"
+#include "xfs_log_priv.h"
+#include "xfs_log_recover.h"
+
+const struct xlog_recover_item_ops xlog_inode_item_ops = {
+	.item_type		= XFS_LI_INODE,
+};

fs/xfs/xfs_log_recover.c

@@ -1785,6 +1785,34 @@ xlog_clear_stale_blocks(
  *
  ******************************************************************************
  */
+static const struct xlog_recover_item_ops *xlog_recover_item_ops[] = {
+	&xlog_buf_item_ops,
+	&xlog_inode_item_ops,
+	&xlog_dquot_item_ops,
+	&xlog_quotaoff_item_ops,
+	&xlog_icreate_item_ops,
+	&xlog_efi_item_ops,
+	&xlog_efd_item_ops,
+	&xlog_rui_item_ops,
+	&xlog_rud_item_ops,
+	&xlog_cui_item_ops,
+	&xlog_cud_item_ops,
+	&xlog_bui_item_ops,
+	&xlog_bud_item_ops,
+};
+
+static const struct xlog_recover_item_ops *
+xlog_find_item_ops(
+	struct xlog_recover_item		*item)
+{
+	unsigned int				i;
+
+	for (i = 0; i < ARRAY_SIZE(xlog_recover_item_ops); i++)
+		if (ITEM_TYPE(item) == xlog_recover_item_ops[i]->item_type)
+			return xlog_recover_item_ops[i];
+
+	return NULL;
+}
 
 /*
  * Sort the log items in the transaction.
@@ -1851,41 +1879,10 @@ xlog_recover_reorder_trans(
 
 	list_splice_init(&trans->r_itemq, &sort_list);
 	list_for_each_entry_safe(item, n, &sort_list, ri_list) {
-		xfs_buf_log_format_t	*buf_f = item->ri_buf[0].i_addr;
+		enum xlog_recover_reorder	fate = XLOG_REORDER_ITEM_LIST;
 
-		switch (ITEM_TYPE(item)) {
-		case XFS_LI_ICREATE:
-			list_move_tail(&item->ri_list, &buffer_list);
-			break;
-		case XFS_LI_BUF:
-			if (buf_f->blf_flags & XFS_BLF_CANCEL) {
-				trace_xfs_log_recover_item_reorder_head(log,
-							trans, item, pass);
-				list_move(&item->ri_list, &cancel_list);
-				break;
-			}
-			if (buf_f->blf_flags & XFS_BLF_INODE_BUF) {
-				list_move(&item->ri_list, &inode_buffer_list);
-				break;
-			}
-			list_move_tail(&item->ri_list, &buffer_list);
-			break;
-		case XFS_LI_INODE:
-		case XFS_LI_DQUOT:
-		case XFS_LI_QUOTAOFF:
-		case XFS_LI_EFD:
-		case XFS_LI_EFI:
-		case XFS_LI_RUI:
-		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, &item_list);
-			break;
-		default:
+		item->ri_ops = xlog_find_item_ops(item);
+		if (!item->ri_ops) {
 			xfs_warn(log->l_mp,
 				"%s: unrecognized type of log operation (%d)",
 				__func__, ITEM_TYPE(item));
@@ -1896,11 +1893,33 @@ xlog_recover_reorder_trans(
 			 */
 			if (!list_empty(&sort_list))
 				list_splice_init(&sort_list, &trans->r_itemq);
-			error = -EIO;
-			goto out;
+			error = -EFSCORRUPTED;
+			break;
+		}
+
+		if (item->ri_ops->reorder)
+			fate = item->ri_ops->reorder(item);
+
+		switch (fate) {
+		case XLOG_REORDER_BUFFER_LIST:
+			list_move_tail(&item->ri_list, &buffer_list);
+			break;
+		case XLOG_REORDER_CANCEL_LIST:
+			trace_xfs_log_recover_item_reorder_head(log,
+					trans, item, pass);
+			list_move(&item->ri_list, &cancel_list);
+			break;
+		case XLOG_REORDER_INODE_BUFFER_LIST:
+			list_move(&item->ri_list, &inode_buffer_list);
+			break;
+		case XLOG_REORDER_ITEM_LIST:
+			trace_xfs_log_recover_item_reorder_tail(log,
+							trans, item, pass);
+			list_move_tail(&item->ri_list, &item_list);
+			break;
 		}
 	}
-out:
+
 	ASSERT(list_empty(&sort_list));
 	if (!list_empty(&buffer_list))
 		list_splice(&buffer_list, &trans->r_itemq);

fs/xfs/xfs_refcount_item.c

@@ -18,6 +18,7 @@
 #include "xfs_log.h"
 #include "xfs_refcount.h"
 #include "xfs_error.h"
+#include "xfs_log_recover.h"
 
 kmem_zone_t	*xfs_cui_zone;
 kmem_zone_t	*xfs_cud_zone;
@@ -570,3 +571,11 @@ xfs_cui_recover(
 	xfs_trans_cancel(tp);
 	return error;
 }
+
+const struct xlog_recover_item_ops xlog_cui_item_ops = {
+	.item_type		= XFS_LI_CUI,
+};
+
+const struct xlog_recover_item_ops xlog_cud_item_ops = {
+	.item_type		= XFS_LI_CUD,
+};

fs/xfs/xfs_rmap_item.c

@@ -18,6 +18,7 @@
 #include "xfs_log.h"
 #include "xfs_rmap.h"
 #include "xfs_error.h"
+#include "xfs_log_recover.h"
 
 kmem_zone_t	*xfs_rui_zone;
 kmem_zone_t	*xfs_rud_zone;
@@ -585,3 +586,11 @@ xfs_rui_recover(
 	xfs_trans_cancel(tp);
 	return error;
 }
+
+const struct xlog_recover_item_ops xlog_rui_item_ops = {
+	.item_type		= XFS_LI_RUI,
+};
+
+const struct xlog_recover_item_ops xlog_rud_item_ops = {
+	.item_type		= XFS_LI_RUD,
+};