xfs: remove the if_ext_max field in struct xfs_ifork

We spent a lot of effort to maintain this field, but it always equals to the
fork size divided by the constant size of an extent.  The prime use of it is
to assert that the two stay in sync.  Just divide the fork size by the extent
size in the few places that we actually use it and remove the overhead
of maintaining it.  Also introduce a few helpers to consolidate the places
where we actually care about the value.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

1 files changed, 10 insertions, 20 deletions

diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index ccd619a993f6..96b29e3286db 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -299,11 +299,8 @@ xfs_iformat(
 {
 	xfs_attr_shortform_t	*atp;
 	int			size;
-	int			error;
+	int			error = 0;
 	xfs_fsize_t             di_size;
-	ip->i_df.if_ext_max =
-		XFS_IFORK_DSIZE(ip) / (uint)sizeof(xfs_bmbt_rec_t);
-	error = 0;
 
 	if (unlikely(be32_to_cpu(dip->di_nextents) +
 		     be16_to_cpu(dip->di_anextents) >
@@ -409,10 +406,10 @@ xfs_iformat(
 	}
 	if (!XFS_DFORK_Q(dip))
 		return 0;
+
 	ASSERT(ip->i_afp == NULL);
 	ip->i_afp = kmem_zone_zalloc(xfs_ifork_zone, KM_SLEEP | KM_NOFS);
-	ip->i_afp->if_ext_max =
-		XFS_IFORK_ASIZE(ip) / (uint)sizeof(xfs_bmbt_rec_t);
+
 	switch (dip->di_aformat) {
 	case XFS_DINODE_FMT_LOCAL:
 		atp = (xfs_attr_shortform_t *)XFS_DFORK_APTR(dip);
@@ -604,10 +601,11 @@ xfs_iformat_btree(
 	 * or the number of extents is greater than the number of
 	 * blocks.
 	 */
-	if (unlikely(XFS_IFORK_NEXTENTS(ip, whichfork) <= ifp->if_ext_max
-	    || XFS_BMDR_SPACE_CALC(nrecs) >
-			XFS_DFORK_SIZE(dip, ip->i_mount, whichfork)
-	    || XFS_IFORK_NEXTENTS(ip, whichfork) > ip->i_d.di_nblocks)) {
+	if (unlikely(XFS_IFORK_NEXTENTS(ip, whichfork) <=
+			XFS_IFORK_MAXEXT(ip, whichfork) ||
+		     XFS_BMDR_SPACE_CALC(nrecs) >
+			XFS_DFORK_SIZE(dip, ip->i_mount, whichfork) ||
+		     XFS_IFORK_NEXTENTS(ip, whichfork) > ip->i_d.di_nblocks)) {
 		xfs_warn(ip->i_mount, "corrupt inode %Lu (btree).",
 			(unsigned long long) ip->i_ino);
 		XFS_CORRUPTION_ERROR("xfs_iformat_btree", XFS_ERRLEVEL_LOW,
@@ -835,12 +833,6 @@ xfs_iread(
 		 * with the uninitialized part of it.
 		 */
 		ip->i_d.di_mode = 0;
-		/*
-		 * Initialize the per-fork minima and maxima for a new
-		 * inode here.  xfs_iformat will do it for old inodes.
-		 */
-		ip->i_df.if_ext_max =
-			XFS_IFORK_DSIZE(ip) / (uint)sizeof(xfs_bmbt_rec_t);
 	}
 
 	/*
@@ -1740,8 +1732,6 @@ xfs_ifree(
 	ip->i_d.di_flags = 0;
 	ip->i_d.di_dmevmask = 0;
 	ip->i_d.di_forkoff = 0;		/* mark the attr fork not in use */
-	ip->i_df.if_ext_max =
-		XFS_IFORK_DSIZE(ip) / (uint)sizeof(xfs_bmbt_rec_t);
 	ip->i_d.di_format = XFS_DINODE_FMT_EXTENTS;
 	ip->i_d.di_aformat = XFS_DINODE_FMT_EXTENTS;
 	/*
@@ -2408,7 +2398,7 @@ xfs_iflush(
 	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_ILOCK_SHARED));
 	ASSERT(!completion_done(&ip->i_flush));
 	ASSERT(ip->i_d.di_format != XFS_DINODE_FMT_BTREE ||
-	       ip->i_d.di_nextents > ip->i_df.if_ext_max);
+	       ip->i_d.di_nextents > XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK));
 
 	iip = ip->i_itemp;
 	mp = ip->i_mount;
@@ -2524,7 +2514,7 @@ xfs_iflush_int(
 	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_ILOCK_SHARED));
 	ASSERT(!completion_done(&ip->i_flush));
 	ASSERT(ip->i_d.di_format != XFS_DINODE_FMT_BTREE ||
-	       ip->i_d.di_nextents > ip->i_df.if_ext_max);
+	       ip->i_d.di_nextents > XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK));
 
 	iip = ip->i_itemp;
 	mp = ip->i_mount;