2022-09-30 23:31:18

by Jaegeuk Kim

Subject: [PATCH] f2fs: allow direct read for zoned device

This reverts dbf8e63f48af ("f2fs: remove device type check for direct IO"),
and apply the below first version, since it contributed out-of-order DIO writes.

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

Cc: [email protected]
Fixes: dbf8e63f48af ("f2fs: remove device type check for direct IO")
Signed-off-by: Eunhee Rho <[email protected]>
Signed-off-by: Jaegeuk Kim <[email protected]>
---
fs/f2fs/f2fs.h | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 2ed00111a399..a0b2c8626a75 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -4535,7 +4535,12 @@ static inline bool f2fs_force_buffered_io(struct inode *inode,
/* disallow direct IO if any of devices has unaligned blksize */
if (f2fs_is_multi_device(sbi) && !sbi->aligned_blksize)
return true;
-
+ /*
+ * 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) && (rw == WRITE))
+ return true;
if (f2fs_lfs_mode(sbi) && (rw == WRITE)) {
if (block_unaligned_IO(inode, iocb, iter))
return true;
--
2.38.0.rc1.362.ged0d419d3c-goog

2022-10-05 14:17:09

by Chao Yu

Subject: Re: [f2fs-dev] [PATCH] f2fs: allow direct read for zoned device

On 2022/10/1 6:53, Jaegeuk Kim wrote:
> This reverts dbf8e63f48af ("f2fs: remove device type check for direct IO"),
> and apply the below first version, since it contributed out-of-order DIO writes.
>
> For zoned devices, f2fs forbids direct IO and forces buffered IO
> to serialize write IOs. However, the constraint does not apply to
> read IOs.
>
> Cc: [email protected]
> Fixes: dbf8e63f48af ("f2fs: remove device type check for direct IO")
> Signed-off-by: Eunhee Rho <[email protected]>
> Signed-off-by: Jaegeuk Kim <[email protected]>

Reviewed-by: Chao Yu <[email protected]>

Thanks,