Re: [PATCH v5 7/8] f2fs: support STATX_DIOALIGN

Jaegeuk Kim
2022-08-29T17:43:11Z

On 08/26, Eric Biggers wrote:
> From: Eric Biggers <ebiggers@google.com>
>
> Add support for STATX_DIOALIGN to f2fs, so that direct I/O alignment
> restrictions are exposed to userspace in a generic way.
>
> Signed-off-by: Eric Biggers <ebiggers@google.com>

Acked-by: Jaegeuk Kim <jaegeuk@kernel.org>

> ---
> fs/f2fs/file.c | 18 ++++++++++++++++++
> 1 file changed, 18 insertions(+)
>
> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> index 8e11311db21060..79177050732803 100644
> --- a/fs/f2fs/file.c
> +++ b/fs/f2fs/file.c
> @@ -847,6 +847,24 @@ int f2fs_getattr(struct user_namespace *mnt_userns, const struct path *path,
> stat->btime.tv_nsec = fi->i_crtime.tv_nsec;
> }
>
> + /*
> + * Return the DIO alignment restrictions if requested. We only return
> + * this information when requested, since on encrypted files it might
> + * take a fair bit of work to get if the file wasn't opened recently.
> + *
> + * f2fs sometimes supports DIO reads but not DIO writes. STATX_DIOALIGN
> + * cannot represent that, so in that case we report no DIO support.
> + */
> + if ((request_mask & STATX_DIOALIGN) && S_ISREG(inode->i_mode)) {
> + unsigned int bsize = i_blocksize(inode);
> +
> + stat->result_mask |= STATX_DIOALIGN;
> + if (!f2fs_force_buffered_io(inode, WRITE)) {
> + stat->dio_mem_align = bsize;
> + stat->dio_offset_align = bsize;
> + }
> + }
> +
> flags = fi->i_flags;
> if (flags & F2FS_COMPR_FL)
> stat->attributes |= STATX_ATTR_COMPRESSED;
> --
> 2.37.2