[PATCH 4/6] xfs: xfs_inode_free_quota_blocks should scan project quota

["Darrick J. Wong" <djwong@kernel.org>]

From: Darrick J. Wong <djwong@kernel.org>

Buffered writers who have run out of quota reservation call
xfs_inode_free_quota_blocks to try to free any space reservations that
might reduce the quota usage.  Unfortunately, the buffered write path
treats "out of project quota" the same as "out of overall space" so this
function has never supported scanning for space that might ease an "out
of project quota" condition.

We're about to start using this function for cases where we actually
/can/ tell if we're out of project quota, so add in this functionality.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
 fs/xfs/xfs_icache.c |    9 +++++++++
 1 file changed, 9 insertions(+)


diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
index 4e226827b33d..703d26d04e0f 100644
--- a/fs/xfs/xfs_icache.c
+++ b/fs/xfs/xfs_icache.c
@@ -1453,6 +1453,15 @@ xfs_inode_free_quota_blocks(
 		}
 	}
 
+	if (XFS_IS_PQUOTA_ENFORCED(ip->i_mount)) {
+		dq = xfs_inode_dquot(ip, XFS_DQTYPE_PROJ);
+		if (dq && xfs_dquot_lowsp(dq)) {
+			eofb.eof_prid = ip->i_d.di_projid;
+			eofb.eof_flags |= XFS_EOF_FLAGS_PRID;
+			do_work = true;
+		}
+	}
+
 	if (!do_work)
 		return false;