[PATCH 2/2] Revert "xfs_reflink_allocate_cow_range"

[Christoph Hellwig <hch@lst.de>]

This reverts commit c0a40310dcfff22df821f4289f657aeac431a709.
---
 fs/xfs/xfs_reflink.c | 98 +++++++++++++++++++++-------------------------------
 fs/xfs/xfs_reflink.h |  4 +--
 fs/xfs/xfs_trace.h   |  1 +
 3 files changed, 42 insertions(+), 61 deletions(-)

diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index 82a7da3..09e0e27 100644
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -364,77 +364,57 @@ xfs_reflink_reserve_cow_range(
 int
 xfs_reflink_allocate_cow_range(
 	struct xfs_inode	*ip,
-	xfs_off_t		offset,
-	xfs_off_t		count)
+	xfs_off_t		pos,
+	xfs_off_t		len)
 {
-	struct xfs_mount	*mp = ip->i_mount;
-	xfs_fileoff_t		offset_fsb = XFS_B_TO_FSBT(mp, offset);
-	xfs_fileoff_t		end_fsb = XFS_B_TO_FSB(mp, offset + count);
-	int			error;
+	struct xfs_ifork	*ifp;
+	struct xfs_bmbt_rec_host	*gotp;
+	struct xfs_bmbt_irec	imap;
+	int			error = 0;
+	xfs_fileoff_t		start_lblk;
+	xfs_fileoff_t		end_lblk;
+	xfs_extnum_t		idx;
 
-	ASSERT(xfs_is_reflink_inode(ip));
+	if (!xfs_is_reflink_inode(ip))
+		return 0;
 
-//	trace_xfs_reflink_allocate_cow_range(ip, offset, count);
-//	trace_xfs_reflink_allocate_cow_range_error(ip, error, _RET_IP_);
+	trace_xfs_reflink_allocate_cow_range(ip, len, pos);
 
-	/*
-	 * Make sure that the dquots are there.
-	 */
-	error = xfs_qm_dqattach(ip, 0);
-	if (error)
-		return error;
+	start_lblk = XFS_B_TO_FSBT(ip->i_mount, pos);
+	end_lblk = XFS_B_TO_FSB(ip->i_mount, pos + len);
+	ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK);
+	xfs_ilock(ip, XFS_ILOCK_EXCL);
 
-	while (offset_fsb < end_fsb) {
-		struct xfs_bmbt_irec	imap;
-		struct xfs_defer_ops	dfops;
-		struct xfs_trans	*tp;
-		xfs_fsblock_t		first_block;
-		int			nimaps = 1, nres;
+	gotp = xfs_iext_bno_to_ext(ifp, start_lblk, &idx);
+	while (gotp) {
+		xfs_bmbt_get_all(gotp, &imap);
 
-		/*
-		 * We have already reserved space for the extent and any
-		 * indirect blocks when creating the delalloc extent,
-		 * there is no need to reserve space in this transaction
-		 * again.
-		 */
-		error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, 0,
-				0, XFS_TRANS_RESERVE, &tp);
-		if (error)
-			return error;
+		if (imap.br_startoff >= end_lblk)
+			break;
+		if (!isnullstartblock(imap.br_startblock))
+			goto advloop;
+		xfs_trim_extent(&imap, start_lblk, end_lblk - start_lblk);
+		trace_xfs_reflink_allocate_cow_extent(ip, &imap);
 
+		xfs_iunlock(ip, XFS_ILOCK_EXCL);
+		error = xfs_iomap_write_allocate(ip, XFS_COW_FORK,
+				XFS_FSB_TO_B(ip->i_mount, imap.br_startoff +
+						imap.br_blockcount - 1), &imap);
 		xfs_ilock(ip, XFS_ILOCK_EXCL);
-		xfs_trans_ijoin(tp, ip, 0);
-
-		xfs_defer_init(&dfops, &first_block);
-
-		// XXX: bmap_read
-
-		error = xfs_bmapi_write(tp, ip, offset_fsb,
-				end_fsb - offset_fsb, XFS_BMAPI_COWFORK,
-				&first_block,
-				XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK),
-				&imap, &nimaps, &dfops);
-		if (error)
-			goto trans_cancel;
-
-		error = xfs_defer_finish(&tp, &dfops, NULL);
-		if (error)
-			goto trans_cancel;
-
-		error = xfs_trans_commit(tp);
 		if (error)
-			goto error0;
-
-		xfs_iunlock(ip, XFS_ILOCK_EXCL);
-
-		offset_fsb = imap.br_startoff + imap.br_blockcount;
+			break;
+advloop:
+		/* Roll on... */
+		idx++;
+		if (idx >= ifp->if_bytes / sizeof(xfs_bmbt_rec_t))
+			break;
+		gotp = xfs_iext_get_ext(ifp, idx);
 	}
 
-trans_cancel:
-	xfs_defer_cancel(&dfops);
-	xfs_trans_cancel(tp);
-error0:
 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
+
+	if (error)
+		trace_xfs_reflink_allocate_cow_range_error(ip, error, _RET_IP_);
 	return error;
 }
 
diff --git a/fs/xfs/xfs_reflink.h b/fs/xfs/xfs_reflink.h
index 859ca50..0e19ec6 100644
--- a/fs/xfs/xfs_reflink.h
+++ b/fs/xfs/xfs_reflink.h
@@ -28,8 +28,8 @@ extern int xfs_reflink_trim_around_shared(struct xfs_inode *ip,
 
 extern int xfs_reflink_reserve_cow_range(struct xfs_inode *ip,
 		xfs_off_t offset, xfs_off_t count);
-extern int xfs_reflink_allocate_cow_range(struct xfs_inode *ip,
-		xfs_off_t offset, xfs_off_t count);
+extern int xfs_reflink_allocate_cow_range(struct xfs_inode *ip, xfs_off_t pos,
+		xfs_off_t len);
 extern bool xfs_reflink_find_cow_mapping(struct xfs_inode *ip, xfs_off_t offset,
 		struct xfs_bmbt_irec *imap, bool *need_alloc);
 extern int xfs_reflink_trim_irec_to_next_cow(struct xfs_inode *ip,
diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
index 26113b9..c8fb91c 100644
--- a/fs/xfs/xfs_trace.h
+++ b/fs/xfs/xfs_trace.h
@@ -3320,6 +3320,7 @@ DEFINE_INODE_IREC_EVENT(xfs_reflink_cow_enospc);
 
 DEFINE_RW_EVENT(xfs_reflink_reserve_cow_range);
 DEFINE_RW_EVENT(xfs_reflink_allocate_cow_range);
+DEFINE_INODE_IREC_EVENT(xfs_reflink_allocate_cow_extent);
 
 DEFINE_INODE_IREC_EVENT(xfs_reflink_bounce_dio_write);
 DEFINE_IOMAP_EVENT(xfs_reflink_find_cow_mapping);
-- 
2.1.4