[RFC PATCH 07/11] xfs: disable direct read path for fs-verity sealed files

[Andrey Albershteyn <aalbersh@redhat.com>]

The direct path is not supported on verity files. Attempts to use direct
I/O path on such files should fall back to buffered I/O path.

Signed-off-by: Andrey Albershteyn <aalbersh@redhat.com>
---
 fs/xfs/xfs_file.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 5eadd9a37c50e..fb4181e38a19d 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -245,7 +245,8 @@ xfs_file_dax_read(
 	struct kiocb		*iocb,
 	struct iov_iter		*to)
 {
-	struct xfs_inode	*ip = XFS_I(iocb->ki_filp->f_mapping->host);
+	struct inode		*inode = iocb->ki_filp->f_mapping->host;
+	struct xfs_inode	*ip = XFS_I(inode);
 	ssize_t			ret = 0;
 
 	trace_xfs_file_dax_read(iocb, to);
@@ -298,10 +299,17 @@ xfs_file_read_iter(
 
 	if (IS_DAX(inode))
 		ret = xfs_file_dax_read(iocb, to);
-	else if (iocb->ki_flags & IOCB_DIRECT)
+	else if (iocb->ki_flags & IOCB_DIRECT && !fsverity_active(inode))
 		ret = xfs_file_dio_read(iocb, to);
-	else
+	else {
+		/*
+		 * In case fs-verity is enabled, we also fallback to the
+		 * buffered read from the direct read path. Therefore,
+		 * IOCB_DIRECT is set and need to be cleared
+		 */
+		iocb->ki_flags &= ~IOCB_DIRECT;
 		ret = xfs_file_buffered_read(iocb, to);
+	}
 
 	if (ret > 0)
 		XFS_STATS_ADD(mp, xs_read_bytes, ret);
-- 
2.31.1