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From:   Andrey Albershteyn <aalbersh@redhat.com>
To:     djwong@kernel.org, dchinner@redhat.com, ebiggers@kernel.org,
        hch@infradead.org, linux-xfs@vger.kernel.org,
        fsverity@lists.linux.dev
Cc:     rpeterso@redhat.com, agruenba@redhat.com, xiang@kernel.org,
        chao@kernel.org, damien.lemoal@opensource.wdc.com, jth@kernel.org,
        linux-erofs@lists.ozlabs.org, linux-btrfs@vger.kernel.org,
        linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net,
        cluster-devel@redhat.com, Andrey Albershteyn <aalbersh@redhat.com>
Subject: [PATCH v2 19/23] xfs: disable direct read path for fs-verity sealed files
Date:   Tue,  4 Apr 2023 16:53:15 +0200
Message-Id: <20230404145319.2057051-20-aalbersh@redhat.com>
In-Reply-To: <20230404145319.2057051-1-aalbersh@redhat.com>
References: <20230404145319.2057051-1-aalbersh@redhat.com>
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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 947b5c436172..9e072e82f6c1 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -244,7 +244,8 @@ 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);
@@ -297,10 +298,17 @@ 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);
-- 
2.38.4