[PATCH 15/33] xfs: plumb struct xfs_trans *tp into xfs_bmapi_convert_one_delalloc

[Dave Chinner <dgc@kernel.org>]

Add a struct xfs_trans *tp parameter to xfs_bmapi_convert_one_delalloc().
When a non-NULL transaction is provided, use it directly instead of
allocating one internally, and skip the ILOCK acquisition and
xfs_trans_ijoin() since the caller already holds the ILOCK with the
inode joined to the transaction.

On success with a caller-supplied transaction, the function returns
without committing or unlocking. On error, it returns the error
without cancelling or unlocking.

When tp is NULL, the existing behaviour is preserved.

All callers currently pass NULL, so there is no functional change.

Assisted-by: LLM
Signed-off-by: Dave Chinner <dgc@kernel.org>
---
 fs/xfs/libxfs/xfs_bmap.c | 43 ++++++++++++++++++++++++----------------
 1 file changed, 26 insertions(+), 17 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index 47c4d5c52b95..7f3a3a02a035 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -4351,6 +4351,7 @@ xfs_bmapi_write(
  */
 static int
 xfs_bmapi_convert_one_delalloc(
+	struct xfs_trans	*tp,
 	struct xfs_inode	*ip,
 	int			whichfork,
 	xfs_off_t		offset,
@@ -4362,23 +4363,27 @@ xfs_bmapi_convert_one_delalloc(
 	xfs_fileoff_t		offset_fsb = XFS_B_TO_FSBT(mp, offset);
 	struct xfs_bmalloca	bma = { NULL };
 	uint16_t		flags = 0;
-	struct xfs_trans	*tp;
+	struct xfs_trans	*local_tp = NULL;
 	int			error;
 
 	if (whichfork == XFS_COW_FORK)
 		flags |= IOMAP_F_SHARED;
 
-	/*
-	 * Space for the extent and indirect blocks was reserved when the
-	 * delalloc extent was created so there's no need to do so here.
-	 */
-	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, 0, 0,
-				XFS_TRANS_RESERVE, &tp);
-	if (error)
-		return error;
+	if (!tp) {
+		/*
+		 * Space for the extent and indirect blocks was reserved when
+		 * the delalloc extent was created so there's no need to do so
+		 * here.
+		 */
+		error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, 0, 0,
+					XFS_TRANS_RESERVE, &local_tp);
+		if (error)
+			return error;
 
-	xfs_ilock(ip, XFS_ILOCK_EXCL);
-	xfs_trans_ijoin(tp, ip, 0);
+		xfs_ilock(ip, XFS_ILOCK_EXCL);
+		xfs_trans_ijoin(local_tp, ip, 0);
+		tp = local_tp;
+	}
 
 	/*
 	 * Look up the extent before extending the extent count so that we
@@ -4470,15 +4475,19 @@ xfs_bmapi_convert_one_delalloc(
 		goto out_finish;
 
 	xfs_bmapi_finish(&bma, whichfork, 0);
-	error = xfs_trans_commit(tp);
-	xfs_iunlock(ip, XFS_ILOCK_EXCL);
+	if (local_tp) {
+		error = xfs_trans_commit(local_tp);
+		xfs_iunlock(ip, XFS_ILOCK_EXCL);
+	}
 	return error;
 
 out_finish:
 	xfs_bmapi_finish(&bma, whichfork, error);
 out_trans_cancel:
-	xfs_trans_cancel(tp);
-	xfs_iunlock(ip, XFS_ILOCK_EXCL);
+	if (local_tp) {
+		xfs_trans_cancel(local_tp);
+		xfs_iunlock(ip, XFS_ILOCK_EXCL);
+	}
 	return error;
 }
 
@@ -4503,8 +4512,8 @@ xfs_bmapi_convert_delalloc(
 	 * delalloc extent if free space is sufficiently fragmented.
 	 */
 	do {
-		error = xfs_bmapi_convert_one_delalloc(ip, whichfork, offset,
-					iomap, seq);
+		error = xfs_bmapi_convert_one_delalloc(NULL, ip, whichfork,
+					offset, iomap, seq);
 		if (error)
 			return error;
 	} while (iomap->offset + iomap->length <= offset);
-- 
2.55.0