xfs: better xfs_trans_alloc interface

Merge xfs_trans_reserve and xfs_trans_alloc into a single function call
that returns a transaction with all the required log and block reservations,
and which allows passing transaction flags directly to avoid the cumbersome
_xfs_trans_alloc interface.

While we're at it we also get rid of the transaction type argument that has
been superflous since we stopped supporting the non-CIL logging mode.  The
guts of it will be removed in another patch.

[dchinner: fixed transaction leak in error path in xfs_setattr_nonsize]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

diff --git a/fs/xfs/xfs_symlink.c b/fs/xfs/xfs_symlink.c
index b44284c..c3aeaa8 100644
--- a/fs/xfs/xfs_symlink.c
+++ b/fs/xfs/xfs_symlink.c
@@ -221,7 +221,6 @@
 	if (error)
 		return error;
 
-	tp = xfs_trans_alloc(mp, XFS_TRANS_SYMLINK);
 	/*
 	 * The symlink will fit into the inode data fork?
 	 * There can't be any attributes so we get the whole variable part.
@@ -231,13 +230,15 @@
 	else
 		fs_blocks = xfs_symlink_blocks(mp, pathlen);
 	resblks = XFS_SYMLINK_SPACE_RES(mp, link_name->len, fs_blocks);
-	error = xfs_trans_reserve(tp, &M_RES(mp)->tr_symlink, resblks, 0);
+
+	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_symlink, resblks, 0, 0, &tp);
 	if (error == -ENOSPC && fs_blocks == 0) {
 		resblks = 0;
-		error = xfs_trans_reserve(tp, &M_RES(mp)->tr_symlink, 0, 0);
+		error = xfs_trans_alloc(mp, &M_RES(mp)->tr_symlink, 0, 0, 0,
+				&tp);
 	}
 	if (error)
-		goto out_trans_cancel;
+		goto out_release_inode;
 
 	xfs_ilock(dp, XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL |
 		      XFS_IOLOCK_PARENT | XFS_ILOCK_PARENT);
@@ -455,12 +456,9 @@
 	 */
 	ASSERT(ip->i_d.di_nextents > 0 && ip->i_d.di_nextents <= 2);
 
-	tp = xfs_trans_alloc(mp, XFS_TRANS_INACTIVE);
-	error = xfs_trans_reserve(tp, &M_RES(mp)->tr_itruncate, 0, 0);
-	if (error) {
-		xfs_trans_cancel(tp);
+	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0, &tp);
+	if (error)
 		return error;
-	}
 
 	xfs_ilock(ip, XFS_ILOCK_EXCL);
 	xfs_trans_ijoin(tp, ip, 0);