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Subject: [PATCH v0] f2fs: allow direct read for zoned device
Reply-To: eunhee83.rho@samsung.com
Sender: Eunhee Rho <eunhee83.rho@samsung.com>
From:   Eunhee Rho <eunhee83.rho@samsung.com>
To:     "jaegeuk@kernel.org" <jaegeuk@kernel.org>,
        "chao@kernel.org" <chao@kernel.org>,
        "linux-f2fs-devel@lists.sourceforge.net" 
        <linux-f2fs-devel@lists.sourceforge.net>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Eunhee Rho <eunhee83.rho@samsung.com>
Message-ID: <20220729002517epcms2p35eed262c3349287436c1848ab350c2d4@epcms2p3>
Date:   Fri, 29 Jul 2022 09:25:17 +0900
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References: <CGME20220729002517epcms2p35eed262c3349287436c1848ab350c2d4@epcms2p3>
Precedence: bulk

For zoned devices, f2fs forbids direct IO and forces buffered IO
to serialize write IOs. However, the constraint does not apply to
read IOs.

Signed-off-by: Eunhee Rho <eunhee83.rho@samsung.com>
---
 fs/f2fs/f2fs.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index d0f428aef34b..f69731f17402 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -4471,7 +4471,7 @@ static inline bool f2fs_force_buffered_io(struct inode *inode,
 	 * for blkzoned device, fallback direct IO to buffered IO, so
 	 * all IOs can be serialized by log-structured write.
 	 */
-	if (f2fs_sb_has_blkzoned(sbi))
+	if (f2fs_sb_has_blkzoned(sbi) && (rw == WRITE))
 		return true;
 	if (f2fs_lfs_mode(sbi) && (rw == WRITE)) {
 		if (block_unaligned_IO(inode, iocb, iter))
-- 
2.25.1