[PATCH v4 2/6] xfs: introduce xfs_dialloc_roll()

[Gao Xiang <hsiangkao@redhat.com>]

From: Dave Chinner <dchinner@redhat.com>

Introduce a helper to make the on-disk inode allocation rolling
logic clearer in preparation of the following cleanup.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
---
 fs/xfs/libxfs/xfs_ialloc.c | 43 ++++++++++++++++++++++++++++++++++++++
 fs/xfs/libxfs/xfs_ialloc.h |  5 +++++
 fs/xfs/xfs_inode.c         | 37 +-------------------------------
 3 files changed, 49 insertions(+), 36 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_ialloc.c b/fs/xfs/libxfs/xfs_ialloc.c
index 45cf7e55f5ee..23e94d43acb2 100644
--- a/fs/xfs/libxfs/xfs_ialloc.c
+++ b/fs/xfs/libxfs/xfs_ialloc.c
@@ -1682,6 +1682,49 @@ xfs_dialloc_ag(
 	return error;
 }
 
+int
+xfs_dialloc_roll(
+	struct xfs_trans	**tpp,
+	struct xfs_buf		*agibp)
+{
+	struct xfs_trans	*tp = *tpp;
+	struct xfs_dquot_acct	*dqinfo = NULL;
+	unsigned int		tflags = 0;
+	int			error;
+
+	/*
+	 * Hold to on to the agibp across the commit so no other allocation can
+	 * come in and take the free inodes we just allocated for our caller.
+	 */
+	xfs_trans_bhold(tp, agibp);
+
+	/*
+	 * We want the quota changes to be associated with the next transaction,
+	 * NOT this one. So, detach the dqinfo from this and attach it to the
+	 * next transaction.
+	 */
+	if (tp->t_dqinfo) {
+		dqinfo = tp->t_dqinfo;
+		tp->t_dqinfo = NULL;
+		tflags = tp->t_flags & XFS_TRANS_DQ_DIRTY;
+		tp->t_flags &= ~XFS_TRANS_DQ_DIRTY;
+	}
+
+	error = xfs_trans_roll(&tp);
+
+	/* Re-attach the quota info that we detached from prev trx. */
+	if (dqinfo) {
+		tp->t_dqinfo = dqinfo;
+		tp->t_flags |= tflags;
+	}
+
+	*tpp = tp;
+	if (error)
+		return error;
+	xfs_trans_bjoin(tp, agibp);
+	return 0;
+}
+
 /*
  * Allocate an inode on disk.
  *
diff --git a/fs/xfs/libxfs/xfs_ialloc.h b/fs/xfs/libxfs/xfs_ialloc.h
index 72b3468b97b1..bd6e0db9e23c 100644
--- a/fs/xfs/libxfs/xfs_ialloc.h
+++ b/fs/xfs/libxfs/xfs_ialloc.h
@@ -32,6 +32,11 @@ xfs_make_iptr(struct xfs_mount *mp, struct xfs_buf *b, int o)
 	return xfs_buf_offset(b, o << (mp)->m_sb.sb_inodelog);
 }
 
+int
+xfs_dialloc_roll(
+	struct xfs_trans	**tpp,
+	struct xfs_buf		*agibp);
+
 /*
  * Allocate an inode on disk.
  * Mode is used to tell whether the new inode will need space, and whether
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 2bfbcf28b1bd..76282da7a05c 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -958,8 +958,6 @@ xfs_dir_ialloc(
 	xfs_inode_t	*ip;
 	xfs_buf_t	*ialloc_context = NULL;
 	int		code;
-	void		*dqinfo;
-	uint		tflags;
 
 	tp = *tpp;
 	ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
@@ -1003,46 +1001,13 @@ xfs_dir_ialloc(
 	 * to succeed the second time.
 	 */
 	if (ialloc_context) {
-		/*
-		 * Normally, xfs_trans_commit releases all the locks.
-		 * We call bhold to hang on to the ialloc_context across
-		 * the commit.  Holding this buffer prevents any other
-		 * processes from doing any allocations in this
-		 * allocation group.
-		 */
-		xfs_trans_bhold(tp, ialloc_context);
-
-		/*
-		 * We want the quota changes to be associated with the next
-		 * transaction, NOT this one. So, detach the dqinfo from this
-		 * and attach it to the next transaction.
-		 */
-		dqinfo = NULL;
-		tflags = 0;
-		if (tp->t_dqinfo) {
-			dqinfo = (void *)tp->t_dqinfo;
-			tp->t_dqinfo = NULL;
-			tflags = tp->t_flags & XFS_TRANS_DQ_DIRTY;
-			tp->t_flags &= ~(XFS_TRANS_DQ_DIRTY);
-		}
-
-		code = xfs_trans_roll(&tp);
-
-		/*
-		 * Re-attach the quota info that we detached from prev trx.
-		 */
-		if (dqinfo) {
-			tp->t_dqinfo = dqinfo;
-			tp->t_flags |= tflags;
-		}
-
+		code = xfs_dialloc_roll(&tp, ialloc_context);
 		if (code) {
 			xfs_buf_relse(ialloc_context);
 			*tpp = tp;
 			*ipp = NULL;
 			return code;
 		}
-		xfs_trans_bjoin(tp, ialloc_context);
 
 		/*
 		 * Call ialloc again. Since we've locked out all
-- 
2.18.4