xfs: remove if_real_bytes

The field is only used for asserts, and to track if we really need to do
realloc when growing the inode fork data.  But the krealloc function
already performs this check internally, so there is no need to keep track
of the real allocation size.

This will free space in the inode fork for keeping a sequence counter of
changes to the extent list.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

1 files changed, 4 insertions, 15 deletions

diff --git a/fs/xfs/libxfs/xfs_inode_fork.c b/fs/xfs/libxfs/xfs_inode_fork.c
index 183ec0cb8921..dee85b0f8846 100644
--- a/fs/xfs/libxfs/xfs_inode_fork.c
+++ b/fs/xfs/libxfs/xfs_inode_fork.c
@@ -158,7 +158,6 @@ xfs_init_local_fork(
 	}
 
 	ifp->if_bytes = size;
-	ifp->if_real_bytes = real_size;
 	ifp->if_flags &= ~(XFS_IFEXTENTS | XFS_IFBROOT);
 	ifp->if_flags |= XFS_IFINLINE;
 }
@@ -226,7 +225,6 @@ xfs_iformat_extents(
 		return -EFSCORRUPTED;
 	}
 
-	ifp->if_real_bytes = 0;
 	ifp->if_bytes = 0;
 	ifp->if_u1.if_root = NULL;
 	ifp->if_height = 0;
@@ -317,7 +315,6 @@ xfs_iformat_btree(
 	ifp->if_flags &= ~XFS_IFEXTENTS;
 	ifp->if_flags |= XFS_IFBROOT;
 
-	ifp->if_real_bytes = 0;
 	ifp->if_bytes = 0;
 	ifp->if_u1.if_root = NULL;
 	ifp->if_height = 0;
@@ -501,7 +498,6 @@ xfs_idata_realloc(
 		 */
 		real_size = roundup(new_size, 4);
 		if (ifp->if_u1.if_data == NULL) {
-			ASSERT(ifp->if_real_bytes == 0);
 			ifp->if_u1.if_data = kmem_alloc(real_size,
 							KM_SLEEP | KM_NOFS);
 		} else {
@@ -509,15 +505,12 @@ xfs_idata_realloc(
 			 * Only do the realloc if the underlying size
 			 * is really changing.
 			 */
-			if (ifp->if_real_bytes != real_size) {
-				ifp->if_u1.if_data =
-					kmem_realloc(ifp->if_u1.if_data,
-							real_size,
-							KM_SLEEP | KM_NOFS);
-			}
+			ifp->if_u1.if_data =
+				kmem_realloc(ifp->if_u1.if_data,
+						real_size,
+						KM_SLEEP | KM_NOFS);
 		}
 	}
-	ifp->if_real_bytes = real_size;
 	ifp->if_bytes = new_size;
 	ASSERT(ifp->if_bytes <= XFS_IFORK_SIZE(ip, whichfork));
 }
@@ -543,17 +536,13 @@ xfs_idestroy_fork(
 	 */
 	if (XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_LOCAL) {
 		if (ifp->if_u1.if_data != NULL) {
-			ASSERT(ifp->if_real_bytes != 0);
 			kmem_free(ifp->if_u1.if_data);
 			ifp->if_u1.if_data = NULL;
-			ifp->if_real_bytes = 0;
 		}
 	} else if ((ifp->if_flags & XFS_IFEXTENTS) && ifp->if_height) {
 		xfs_iext_destroy(ifp);
 	}
 
-	ASSERT(ifp->if_real_bytes == 0);
-
 	if (whichfork == XFS_ATTR_FORK) {
 		kmem_zone_free(xfs_ifork_zone, ip->i_afp);
 		ip->i_afp = NULL;