Re: [PATCH v4 6/9] f2fs: don't allow DIO reads but not DIO writes
From: Jaegeuk Kim <jaegeuk@kernel.org>
Date: 2022-07-24 02:02:08
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linux-block, linux-ext4, linux-f2fs-devel, linux-fscrypt, linux-fsdevel, linux-xfs, lkml
On 07/22, Eric Biggers wrote:
From: Eric Biggers <redacted> Currently, if an f2fs filesystem is mounted with the mode=lfs and io_bits mount options, DIO reads are allowed but DIO writes are not. Allowing DIO reads but not DIO writes is an unusual restriction, which is likely to be surprising to applications, namely any application that both reads and writes from a file (using O_DIRECT). This behavior is also incompatible with the proposed STATX_DIOALIGN extension to statx. Given this, let's drop the support for DIO reads in this configuration.
IIRC, we allowed DIO reads since applications complained a lower performance. So, I'm afraid this change will make another confusion to users. Could you please apply the new bahavior only for STATX_DIOALIGN?
quoted hunk ↗ jump to hunk
Signed-off-by: Eric Biggers <redacted> --- fs/f2fs/file.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 5e5c97fccfb4ee..ad0212848a1ab9 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c@@ -823,7 +823,6 @@ static inline bool f2fs_force_buffered_io(struct inode *inode, struct kiocb *iocb, struct iov_iter *iter) { struct f2fs_sb_info *sbi = F2FS_I_SB(inode); - int rw = iov_iter_rw(iter); if (!fscrypt_dio_supported(inode)) return true;@@ -841,7 +840,7 @@ static inline bool f2fs_force_buffered_io(struct inode *inode, */ if (f2fs_sb_has_blkzoned(sbi)) return true; - if (f2fs_lfs_mode(sbi) && (rw == WRITE)) { + if (f2fs_lfs_mode(sbi)) { if (block_unaligned_IO(inode, iocb, iter)) return true; if (F2FS_IO_ALIGNED(sbi))-- 2.37.0