xfs: format log items write directly into the linear CIL buffer

Instead of setting up pointers to memory locations in iop_format which then
get copied into the CIL linear buffer after return move the copy into
the individual inode items.  This avoids the need to always have a memory
block in the exact same layout that gets written into the log around, and
allow the log items to be much more flexible in their in-memory layouts.

The only caveat is that we need to properly align the data for each
iovec so that don't have structures misaligned in subsequent iovecs.

Note that all log item format routines now need to be careful to modify
the copy of the item that was placed into the CIL after calls to
xlog_copy_iovec instead of the in-memory copy.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

1 files changed, 45 insertions, 47 deletions

diff --git a/fs/xfs/xfs_inode_item.c b/fs/xfs/xfs_inode_item.c
index c75e14beff06..6ab318f80c96 100644
--- a/fs/xfs/xfs_inode_item.c
+++ b/fs/xfs/xfs_inode_item.c
@@ -163,6 +163,7 @@ xfs_inode_item_size(
 STATIC int
 xfs_inode_item_format_extents(
 	struct xfs_inode	*ip,
+	struct xfs_log_vec	*lv,
 	struct xfs_log_iovec	**vecp,
 	int			whichfork,
 	int			type)
@@ -177,7 +178,7 @@ xfs_inode_item_format_extents(
 		ip->i_itemp->ili_aextents_buf = ext_buffer;
 
 	len = xfs_iextents_copy(ip, ext_buffer, whichfork);
-	xlog_copy_iovec(vecp, type, ext_buffer, len);
+	xlog_copy_iovec(lv, vecp, type, ext_buffer, len);
 	return len;
 }
 
@@ -212,8 +213,9 @@ xfs_inode_item_format_v1_inode(
 STATIC void
 xfs_inode_item_format_data_fork(
 	struct xfs_inode_log_item *iip,
-	struct xfs_log_iovec	**vecp,
-	int			*nvecs)
+	struct xfs_inode_log_format *ilf,
+	struct xfs_log_vec	*lv,
+	struct xfs_log_iovec	**vecp)
 {
 	struct xfs_inode	*ip = iip->ili_inode;
 	size_t			data_bytes;
@@ -239,19 +241,19 @@ xfs_inode_item_format_data_fork(
 				 * extents, so just point to the
 				 * real extents array.
 				 */
-				xlog_copy_iovec(vecp, XLOG_REG_TYPE_IEXT,
+				xlog_copy_iovec(lv, vecp, XLOG_REG_TYPE_IEXT,
 						ip->i_df.if_u1.if_extents,
 						ip->i_df.if_bytes);
-				iip->ili_format.ilf_dsize = ip->i_df.if_bytes;
+				ilf->ilf_dsize = ip->i_df.if_bytes;
 			} else
 #endif
 			{
-				iip->ili_format.ilf_dsize =
-					xfs_inode_item_format_extents(ip, vecp,
+				ilf->ilf_dsize =
+					xfs_inode_item_format_extents(ip, lv, vecp,
 						XFS_DATA_FORK, XLOG_REG_TYPE_IEXT);
 				ASSERT(iip->ili_format.ilf_dsize <= ip->i_df.if_bytes);
 			}
-			(*nvecs)++;
+			ilf->ilf_size++;
 		} else {
 			iip->ili_fields &= ~XFS_ILOG_DEXT;
 		}
@@ -264,11 +266,11 @@ xfs_inode_item_format_data_fork(
 		if ((iip->ili_fields & XFS_ILOG_DBROOT) &&
 		    ip->i_df.if_broot_bytes > 0) {
 			ASSERT(ip->i_df.if_broot != NULL);
-			xlog_copy_iovec(vecp, XLOG_REG_TYPE_IBROOT,
+			xlog_copy_iovec(lv, vecp, XLOG_REG_TYPE_IBROOT,
 					ip->i_df.if_broot,
 					ip->i_df.if_broot_bytes);
-			(*nvecs)++;
-			iip->ili_format.ilf_dsize = ip->i_df.if_broot_bytes;
+			ilf->ilf_dsize = ip->i_df.if_broot_bytes;
+			ilf->ilf_size++;
 		} else {
 			ASSERT(!(iip->ili_fields &
 				 XFS_ILOG_DBROOT));
@@ -291,10 +293,10 @@ xfs_inode_item_format_data_fork(
 			       ip->i_df.if_real_bytes == data_bytes);
 			ASSERT(ip->i_df.if_u1.if_data != NULL);
 			ASSERT(ip->i_d.di_size > 0);
-			xlog_copy_iovec(vecp, XLOG_REG_TYPE_ILOCAL,
+			xlog_copy_iovec(lv, vecp, XLOG_REG_TYPE_ILOCAL,
 					ip->i_df.if_u1.if_data, data_bytes);
-			(*nvecs)++;
-			iip->ili_format.ilf_dsize = (unsigned)data_bytes;
+			ilf->ilf_dsize = (unsigned)data_bytes;
+			ilf->ilf_size++;
 		} else {
 			iip->ili_fields &= ~XFS_ILOG_DDATA;
 		}
@@ -303,19 +305,15 @@ xfs_inode_item_format_data_fork(
 		iip->ili_fields &=
 			~(XFS_ILOG_DDATA | XFS_ILOG_DBROOT |
 			  XFS_ILOG_DEXT | XFS_ILOG_UUID);
-		if (iip->ili_fields & XFS_ILOG_DEV) {
-			iip->ili_format.ilf_u.ilfu_rdev =
-				ip->i_df.if_u2.if_rdev;
-		}
+		if (iip->ili_fields & XFS_ILOG_DEV)
+			ilf->ilf_u.ilfu_rdev = ip->i_df.if_u2.if_rdev;
 		break;
 	case XFS_DINODE_FMT_UUID:
 		iip->ili_fields &=
 			~(XFS_ILOG_DDATA | XFS_ILOG_DBROOT |
 			  XFS_ILOG_DEXT | XFS_ILOG_DEV);
-		if (iip->ili_fields & XFS_ILOG_UUID) {
-			iip->ili_format.ilf_u.ilfu_uuid =
-				ip->i_df.if_u2.if_uuid;
-		}
+		if (iip->ili_fields & XFS_ILOG_UUID)
+			ilf->ilf_u.ilfu_uuid = ip->i_df.if_u2.if_uuid;
 		break;
 	default:
 		ASSERT(0);
@@ -326,8 +324,9 @@ xfs_inode_item_format_data_fork(
 STATIC void
 xfs_inode_item_format_attr_fork(
 	struct xfs_inode_log_item *iip,
-	struct xfs_log_iovec	**vecp,
-	int			*nvecs)
+	struct xfs_inode_log_format *ilf,
+	struct xfs_log_vec	*lv,
+	struct xfs_log_iovec	**vecp)
 {
 	struct xfs_inode	*ip = iip->ili_inode;
 	size_t			data_bytes;
@@ -348,17 +347,17 @@ xfs_inode_item_format_attr_fork(
 			 * There are not delayed allocation extents
 			 * for attributes, so just point at the array.
 			 */
-			xlog_copy_iovec(vecp, XLOG_REG_TYPE_IATTR_EXT,
+			xlog_copy_iovec(lv, vecp, XLOG_REG_TYPE_IATTR_EXT,
 					ip->i_afp->if_u1.if_extents,
 					ip->i_afp->if_bytes);
-			iip->ili_format.ilf_asize = ip->i_afp->if_bytes;
+			ilf->ilf_asize = ip->i_afp->if_bytes;
 #else
 			ASSERT(iip->ili_aextents_buf == NULL);
-			iip->ili_format.ilf_asize =
-				xfs_inode_item_format_extents(ip, vecp,
+			ilf->ilf_asize =
+				xfs_inode_item_format_extents(ip, lv, vecp,
 					XFS_ATTR_FORK, XLOG_REG_TYPE_IATTR_EXT);
 #endif
-			(*nvecs)++;
+			ilf->ilf_size++;
 		} else {
 			iip->ili_fields &= ~XFS_ILOG_AEXT;
 		}
@@ -371,11 +370,11 @@ xfs_inode_item_format_attr_fork(
 		    ip->i_afp->if_broot_bytes > 0) {
 			ASSERT(ip->i_afp->if_broot != NULL);
 
-			xlog_copy_iovec(vecp, XLOG_REG_TYPE_IATTR_BROOT,
+			xlog_copy_iovec(lv, vecp, XLOG_REG_TYPE_IATTR_BROOT,
 					ip->i_afp->if_broot,
 					ip->i_afp->if_broot_bytes);
-			(*nvecs)++;
-			iip->ili_format.ilf_asize = ip->i_afp->if_broot_bytes;
+			ilf->ilf_asize = ip->i_afp->if_broot_bytes;
+			ilf->ilf_size++;
 		} else {
 			iip->ili_fields &= ~XFS_ILOG_ABROOT;
 		}
@@ -395,11 +394,11 @@ xfs_inode_item_format_attr_fork(
 			ASSERT(ip->i_afp->if_real_bytes == 0 ||
 			       ip->i_afp->if_real_bytes == data_bytes);
 			ASSERT(ip->i_afp->if_u1.if_data != NULL);
-			xlog_copy_iovec(vecp, XLOG_REG_TYPE_IATTR_LOCAL,
+			xlog_copy_iovec(lv, vecp, XLOG_REG_TYPE_IATTR_LOCAL,
 					ip->i_afp->if_u1.if_data,
 					data_bytes);
-			(*nvecs)++;
-			iip->ili_format.ilf_asize = (unsigned)data_bytes;
+			ilf->ilf_asize = (unsigned)data_bytes;
+			ilf->ilf_size++;
 		} else {
 			iip->ili_fields &= ~XFS_ILOG_ADATA;
 		}
@@ -420,28 +419,28 @@ xfs_inode_item_format_attr_fork(
 STATIC void
 xfs_inode_item_format(
 	struct xfs_log_item	*lip,
-	struct xfs_log_iovec	*vecp)
+	struct xfs_log_vec	*lv)
 {
 	struct xfs_inode_log_item *iip = INODE_ITEM(lip);
 	struct xfs_inode	*ip = iip->ili_inode;
-	uint			nvecs;
+	struct xfs_inode_log_format *ilf;
+	struct xfs_log_iovec	*vecp = NULL;
 
-	xlog_copy_iovec(&vecp, XLOG_REG_TYPE_IFORMAT,
+	ilf = xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_IFORMAT,
 			&iip->ili_format,
 			sizeof(struct xfs_inode_log_format));
-	nvecs = 1;
-
-	xlog_copy_iovec(&vecp, XLOG_REG_TYPE_ICORE,
-			&ip->i_d,
-			xfs_icdinode_size(ip->i_d.di_version));
-	nvecs++;
+	ilf->ilf_size = 1;
 
 	if (ip->i_d.di_version == 1)
 		xfs_inode_item_format_v1_inode(ip);
+	xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_ICORE,
+			&ip->i_d,
+			xfs_icdinode_size(ip->i_d.di_version));
+	ilf->ilf_size++;
 
-	xfs_inode_item_format_data_fork(iip, &vecp, &nvecs);
+	xfs_inode_item_format_data_fork(iip, ilf, lv, &vecp);
 	if (XFS_IFORK_Q(ip)) {
-		xfs_inode_item_format_attr_fork(iip, &vecp, &nvecs);
+		xfs_inode_item_format_attr_fork(iip, ilf, lv, &vecp);
 	} else {
 		iip->ili_fields &=
 			~(XFS_ILOG_ADATA | XFS_ILOG_ABROOT | XFS_ILOG_AEXT);
@@ -455,7 +454,6 @@ xfs_inode_item_format(
 	 */
 	iip->ili_format.ilf_fields = XFS_ILOG_CORE |
 		(iip->ili_fields & ~XFS_ILOG_TIMESTAMP);
-	iip->ili_format.ilf_size = nvecs;
 }
 
 /*