xfs: provide helper for counting extents from if_bytes

commit 5d829300bee000980a09ac2ccb761cb25867b67c upstream.

The open-coded pattern:

ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t)

is all over the xfs code; provide a new helper
xfs_iext_count(ifp) to count the number of inline extents
in an inode fork.

[dchinner: pick up several missed conversions]

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/fs/xfs/libxfs/xfs_inode_fork.c b/fs/xfs/libxfs/xfs_inode_fork.c
index 5dd56d3..5fbe24c 100644
--- a/fs/xfs/libxfs/xfs_inode_fork.c
+++ b/fs/xfs/libxfs/xfs_inode_fork.c
@@ -775,6 +775,13 @@
 	}
 }
 
+/* Count number of incore extents based on if_bytes */
+xfs_extnum_t
+xfs_iext_count(struct xfs_ifork *ifp)
+{
+	return ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t);
+}
+
 /*
  * Convert in-core extents to on-disk form
  *
@@ -803,7 +810,7 @@
 	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_ILOCK_SHARED));
 	ASSERT(ifp->if_bytes > 0);
 
-	nrecs = ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t);
+	nrecs = xfs_iext_count(ifp);
 	XFS_BMAP_TRACE_EXLIST(ip, nrecs, whichfork);
 	ASSERT(nrecs > 0);
 
@@ -941,7 +948,7 @@
 	xfs_extnum_t	idx)		/* index of target extent */
 {
 	ASSERT(idx >= 0);
-	ASSERT(idx < ifp->if_bytes / sizeof(xfs_bmbt_rec_t));
+	ASSERT(idx < xfs_iext_count(ifp));
 
 	if ((ifp->if_flags & XFS_IFEXTIREC) && (idx == 0)) {
 		return ifp->if_u1.if_ext_irec->er_extbuf;
@@ -1017,7 +1024,7 @@
 	int		new_size;	/* size of extents after adding */
 	xfs_extnum_t	nextents;	/* number of extents in file */
 
-	nextents = ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t);
+	nextents = xfs_iext_count(ifp);
 	ASSERT((idx >= 0) && (idx <= nextents));
 	byte_diff = ext_diff * sizeof(xfs_bmbt_rec_t);
 	new_size = ifp->if_bytes + byte_diff;
@@ -1241,7 +1248,7 @@
 	trace_xfs_iext_remove(ip, idx, state, _RET_IP_);
 
 	ASSERT(ext_diff > 0);
-	nextents = ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t);
+	nextents = xfs_iext_count(ifp);
 	new_size = (nextents - ext_diff) * sizeof(xfs_bmbt_rec_t);
 
 	if (new_size == 0) {
@@ -1270,7 +1277,7 @@
 
 	ASSERT(!(ifp->if_flags & XFS_IFEXTIREC));
 	ASSERT(idx < XFS_INLINE_EXTS);
-	nextents = ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t);
+	nextents = xfs_iext_count(ifp);
 	ASSERT(((nextents - ext_diff) > 0) &&
 		(nextents - ext_diff) < XFS_INLINE_EXTS);
 
@@ -1309,7 +1316,7 @@
 	ASSERT(!(ifp->if_flags & XFS_IFEXTIREC));
 	new_size = ifp->if_bytes -
 		(ext_diff * sizeof(xfs_bmbt_rec_t));
-	nextents = ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t);
+	nextents = xfs_iext_count(ifp);
 
 	if (new_size == 0) {
 		xfs_iext_destroy(ifp);
@@ -1546,7 +1553,7 @@
 	int		size;		/* size of file extents */
 
 	ASSERT(ifp->if_flags & XFS_IFEXTIREC);
-	nextents = ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t);
+	nextents = xfs_iext_count(ifp);
 	ASSERT(nextents <= XFS_LINEAR_EXTS);
 	size = nextents * sizeof(xfs_bmbt_rec_t);
 
@@ -1620,7 +1627,7 @@
 	xfs_extnum_t	nextents;	/* number of file extents */
 	xfs_fileoff_t	startoff = 0;	/* start offset of extent */
 
-	nextents = ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t);
+	nextents = xfs_iext_count(ifp);
 	if (nextents == 0) {
 		*idxp = 0;
 		return NULL;
@@ -1733,8 +1740,8 @@
 
 	ASSERT(ifp->if_flags & XFS_IFEXTIREC);
 	ASSERT(page_idx >= 0);
-	ASSERT(page_idx <= ifp->if_bytes / sizeof(xfs_bmbt_rec_t));
-	ASSERT(page_idx < ifp->if_bytes / sizeof(xfs_bmbt_rec_t) || realloc);
+	ASSERT(page_idx <= xfs_iext_count(ifp));
+	ASSERT(page_idx < xfs_iext_count(ifp) || realloc);
 
 	nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ;
 	erp_idx = 0;
@@ -1782,7 +1789,7 @@
 	xfs_extnum_t	nextents;	/* number of extents in file */
 
 	ASSERT(!(ifp->if_flags & XFS_IFEXTIREC));
-	nextents = ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t);
+	nextents = xfs_iext_count(ifp);
 	ASSERT(nextents <= XFS_LINEAR_EXTS);
 
 	erp = kmem_alloc(sizeof(xfs_ext_irec_t), KM_NOFS);
@@ -1906,7 +1913,7 @@
 
 	ASSERT(ifp->if_flags & XFS_IFEXTIREC);
 	nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ;
-	nextents = ifp->if_bytes / (uint)sizeof(xfs_bmbt_rec_t);
+	nextents = xfs_iext_count(ifp);
 
 	if (nextents == 0) {
 		xfs_iext_destroy(ifp);