xfs: refactor redo intent item processing

Refactor the EFI intent item recovery (and cancellation) functions
into a general function that scans the AIL and an intent item type
specific handler.  Move the function that recovers a single EFI item
into the extent free item code.  We'll want the generalized function
when we start wiring up more redo item types.

Furthermore, ensure that log recovery only replays the redo items
that were in the AIL prior to recovery by checking the item LSN
against the largest LSN seen during log scanning.  As written this
should never happen, but we can be defensive anyway.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

1 files changed, 65 insertions, 0 deletions

diff --git a/fs/xfs/xfs_extfree_item.c b/fs/xfs/xfs_extfree_item.c
index ab779460ecbf..8c49f883934a 100644
--- a/fs/xfs/xfs_extfree_item.c
+++ b/fs/xfs/xfs_extfree_item.c
@@ -20,6 +20,7 @@
 #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_trans_priv.h"
@@ -486,3 +487,67 @@ xfs_efd_init(
 
 	return efdp;
 }
+
+/*
+ * Process an extent free intent item that was recovered from
+ * the log.  We need to free the extents that it describes.
+ */
+int
+xfs_efi_recover(
+	struct xfs_mount	*mp,
+	struct xfs_efi_log_item	*efip)
+{
+	struct xfs_efd_log_item	*efdp;
+	struct xfs_trans	*tp;
+	int			i;
+	int			error = 0;
+	xfs_extent_t		*extp;
+	xfs_fsblock_t		startblock_fsb;
+
+	ASSERT(!test_bit(XFS_EFI_RECOVERED, &efip->efi_flags));
+
+	/*
+	 * First check the validity of the extents described by the
+	 * EFI.  If any are bad, then assume that all are bad and
+	 * just toss the EFI.
+	 */
+	for (i = 0; i < efip->efi_format.efi_nextents; i++) {
+		extp = &(efip->efi_format.efi_extents[i]);
+		startblock_fsb = XFS_BB_TO_FSB(mp,
+				   XFS_FSB_TO_DADDR(mp, extp->ext_start));
+		if ((startblock_fsb == 0) ||
+		    (extp->ext_len == 0) ||
+		    (startblock_fsb >= mp->m_sb.sb_dblocks) ||
+		    (extp->ext_len >= mp->m_sb.sb_agblocks)) {
+			/*
+			 * This will pull the EFI from the AIL and
+			 * free the memory associated with it.
+			 */
+			set_bit(XFS_EFI_RECOVERED, &efip->efi_flags);
+			xfs_efi_release(efip);
+			return -EIO;
+		}
+	}
+
+	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0, &tp);
+	if (error)
+		return error;
+	efdp = xfs_trans_get_efd(tp, efip, efip->efi_format.efi_nextents);
+
+	for (i = 0; i < efip->efi_format.efi_nextents; i++) {
+		extp = &(efip->efi_format.efi_extents[i]);
+		error = xfs_trans_free_extent(tp, efdp, extp->ext_start,
+					      extp->ext_len);
+		if (error)
+			goto abort_error;
+
+	}
+
+	set_bit(XFS_EFI_RECOVERED, &efip->efi_flags);
+	error = xfs_trans_commit(tp);
+	return error;
+
+abort_error:
+	xfs_trans_cancel(tp);
+	return error;
+}