[PATCH v2 10/13] xfs: Unmap blocks according to forcealign

[John Garry <john.g.garry@xxxxxxxxxx>]

For when forcealign is enabled, blocks in an inode need to be unmapped
according to extent alignment, like what is already done for rtvol.

Signed-off-by: John Garry <john.g.garry@xxxxxxxxxx>
---
 fs/xfs/libxfs/xfs_bmap.c | 46 ++++++++++++++++++++++++++++++++--------
 1 file changed, 37 insertions(+), 9 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index db12f006646a..07478c88a51b 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -5403,6 +5403,25 @@ xfs_bmap_del_extent_real(
 	return 0;
 }
 
+static xfs_extlen_t
+xfs_bunmapi_align(
+	struct xfs_inode	*ip,
+	xfs_fsblock_t		bno)
+{
+	struct xfs_mount	*mp = ip->i_mount;
+	xfs_agblock_t		agbno;
+
+	if (xfs_inode_has_forcealign(ip)) {
+		if (is_power_of_2(ip->i_extsize))
+			return bno & (ip->i_extsize - 1);
+
+		agbno = XFS_FSB_TO_AGBNO(mp, bno);
+		return agbno % ip->i_extsize;
+	}
+	ASSERT(XFS_IS_REALTIME_INODE(ip));
+	return xfs_rtb_to_rtxoff(ip->i_mount, bno);
+}
+
 /*
  * Unmap (remove) blocks from a file.
  * If nexts is nonzero then the number of extents to remove is limited to
@@ -5425,6 +5444,7 @@ __xfs_bunmapi(
 	struct xfs_bmbt_irec	got;		/* current extent record */
 	struct xfs_ifork	*ifp;		/* inode fork pointer */
 	int			isrt;		/* freeing in rt area */
+	int			isforcealign;	/* freeing for inode with forcealign */
 	int			logflags;	/* transaction logging flags */
 	xfs_extlen_t		mod;		/* rt extent offset */
 	struct xfs_mount	*mp = ip->i_mount;
@@ -5462,6 +5482,8 @@ __xfs_bunmapi(
 	}
 	XFS_STATS_INC(mp, xs_blk_unmap);
 	isrt = xfs_ifork_is_realtime(ip, whichfork);
+	isforcealign = (whichfork != XFS_ATTR_FORK) &&
+			xfs_inode_has_forcealign(ip);
 	end = start + len;
 
 	if (!xfs_iext_lookup_extent_before(ip, ifp, &end, &icur, &got)) {
@@ -5513,14 +5535,13 @@ __xfs_bunmapi(
 		if (del.br_startoff + del.br_blockcount > end + 1)
 			del.br_blockcount = end + 1 - del.br_startoff;
 
-		if (!isrt || (flags & XFS_BMAPI_REMAP))
+		if ((!isrt && !isforcealign) || (flags & XFS_BMAPI_REMAP))
 			goto delete;
 
-		mod = xfs_rtb_to_rtxoff(mp,
-				del.br_startblock + del.br_blockcount);
+		mod = xfs_bunmapi_align(ip, del.br_startblock + del.br_blockcount);
 		if (mod) {
 			/*
-			 * Realtime extent not lined up at the end.
+			 * Not aligned to allocation unit on the end.
 			 * The extent could have been split into written
 			 * and unwritten pieces, or we could just be
 			 * unmapping part of it.  But we can't really
@@ -5565,14 +5586,21 @@ __xfs_bunmapi(
 			goto nodelete;
 		}
 
-		mod = xfs_rtb_to_rtxoff(mp, del.br_startblock);
+		mod = xfs_bunmapi_align(ip, del.br_startblock);
 		if (mod) {
-			xfs_extlen_t off = mp->m_sb.sb_rextsize - mod;
+			xfs_extlen_t off;
+
+			if (isforcealign) {
+				off = ip->i_extsize - mod;
+			} else {
+				ASSERT(isrt);
+				off = mp->m_sb.sb_rextsize - mod;
+			}
 
 			/*
-			 * Realtime extent is lined up at the end but not
-			 * at the front.  We'll get rid of full extents if
-			 * we can.
+			 * Extent is lined up to the allocation unit at the
+			 * end but not at the front.  We'll get rid of full
+			 * extents if we can.
 			 */
 			if (del.br_blockcount > off) {
 				del.br_blockcount -= off;
-- 
2.31.1