On Tue, Aug 13, 2019 at 12:03:06PM +0300, Nikolay Borisov wrote:
> This macro encodes a trivial struct initializations, just open code it.
>
> Signed-off-by: Nikolay Borisov <nborisov@xxxxxxxx>
> ---
Seems fine:
Reviewed-by: Brian Foster <bfoster@xxxxxxxxxx>
What might be more interesting is to audit the cases where nmap is
always 1 and see if we can start eliminating some of this code where it
isn't needed. For example, it looks xfs_buf_readahead_map() only ever
uses nmap == 1. Can we pass a block/len directly there and push the
map/nmap parameters further down the stack? FWIW, I also see several
functions on a quick glance (xfs_dabuf_map(), xfs_buf_map_from_irec())
that take map/nmaps params, assert that nmaps == 1 yet still have
iteration code for nmap > 1 cases.
> fs/xfs/xfs_buf.c | 4 ++--
> fs/xfs/xfs_buf.h | 9 +++------
> fs/xfs/xfs_trans.h | 6 ++++--
> 3 files changed, 9 insertions(+), 10 deletions(-)
>
> diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
> index 99c66f80d7cc..389c5b590f11 100644
> --- a/fs/xfs/xfs_buf.c
> +++ b/fs/xfs/xfs_buf.c
> @@ -658,7 +658,7 @@ xfs_buf_incore(
> {
> struct xfs_buf *bp;
> int error;
> - DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
> + struct xfs_buf_map map = { .bm_bn = blkno, .bm_len = numblks };
>
> error = xfs_buf_find(target, &map, 1, flags, NULL, &bp);
> if (error)
> @@ -905,7 +905,7 @@ xfs_buf_get_uncached(
> unsigned long page_count;
> int error, i;
> struct xfs_buf *bp;
> - DEFINE_SINGLE_BUF_MAP(map, XFS_BUF_DADDR_NULL, numblks);
> + struct xfs_buf_map map = { .bm_bn = XFS_BUF_DADDR_NULL, .bm_len = numblks };
>
> /* flags might contain irrelevant bits, pass only what we care about */
> bp = _xfs_buf_alloc(target, &map, 1, flags & XBF_NO_IOACCT);
> diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h
> index ec7037284d62..548dfb0c6e27 100644
> --- a/fs/xfs/xfs_buf.h
> +++ b/fs/xfs/xfs_buf.h
> @@ -104,9 +104,6 @@ struct xfs_buf_map {
> int bm_len; /* size of I/O */
> };
>
> -#define DEFINE_SINGLE_BUF_MAP(map, blkno, numblk) \
> - struct xfs_buf_map (map) = { .bm_bn = (blkno), .bm_len = (numblk) };
> -
> struct xfs_buf_ops {
> char *name;
> union {
> @@ -209,7 +206,7 @@ xfs_buf_get(
> xfs_daddr_t blkno,
> size_t numblks)
> {
> - DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
> + struct xfs_buf_map map = { .bm_bn = blkno, .bm_len = numblks };
> return xfs_buf_get_map(target, &map, 1, 0);
> }
>
> @@ -221,7 +218,7 @@ xfs_buf_read(
> xfs_buf_flags_t flags,
> const struct xfs_buf_ops *ops)
> {
> - DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
> + struct xfs_buf_map map = { .bm_bn = blkno, .bm_len = numblks };
> return xfs_buf_read_map(target, &map, 1, flags, ops);
> }
>
> @@ -232,7 +229,7 @@ xfs_buf_readahead(
> size_t numblks,
> const struct xfs_buf_ops *ops)
> {
> - DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
> + struct xfs_buf_map map = { .bm_bn = blkno, .bm_len = numblks };
> return xfs_buf_readahead_map(target, &map, 1, ops);
> }
>
> diff --git a/fs/xfs/xfs_trans.h b/fs/xfs/xfs_trans.h
> index 64d7f171ebd3..8d6fce5c0320 100644
> --- a/fs/xfs/xfs_trans.h
> +++ b/fs/xfs/xfs_trans.h
> @@ -182,7 +182,8 @@ xfs_trans_get_buf(
> int numblks,
> uint flags)
> {
> - DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
> + struct xfs_buf_map map = { .bm_bn = blkno, .bm_len = numblks };
> +
> return xfs_trans_get_buf_map(tp, target, &map, 1, flags);
> }
>
> @@ -205,7 +206,8 @@ xfs_trans_read_buf(
> struct xfs_buf **bpp,
> const struct xfs_buf_ops *ops)
> {
> - DEFINE_SINGLE_BUF_MAP(map, blkno, numblks);
> + struct xfs_buf_map map = { .bm_bn = blkno, .bm_len = numblks };
> +
> return xfs_trans_read_buf_map(mp, tp, target, &map, 1,
> flags, bpp, ops);
> }
> --
> 2.17.1
>
