On 1/30/20 7:33 AM, Christoph Hellwig wrote:
> Just dereference bp->b_addr directly and make the code a little
> simpler and more clear.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
...
> diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c
> index 2f60fc3c99a0..772649f4eed6 100644
> --- a/fs/xfs/libxfs/xfs_sb.c
> +++ b/fs/xfs/libxfs/xfs_sb.c
> @@ -220,7 +220,7 @@ xfs_validate_sb_common(
> struct xfs_buf *bp,
> struct xfs_sb *sbp)
> {
> - struct xfs_dsb *dsb = XFS_BUF_TO_SBP(bp);
> + struct xfs_dsb *dsb = bp->b_addr;
> uint32_t agcount = 0;
> uint32_t rem;
>
> @@ -681,7 +681,7 @@ xfs_sb_read_verify(
> {
> struct xfs_sb sb;
> struct xfs_mount *mp = bp->b_mount;
> - struct xfs_dsb *dsb = XFS_BUF_TO_SBP(bp);
> + struct xfs_dsb *dsb = bp->b_addr;
> int error;
>
> /*
> @@ -707,7 +707,7 @@ xfs_sb_read_verify(
> * Check all the superblock fields. Don't byteswap the xquota flags
> * because _verify_common checks the on-disk values.
> */
> - __xfs_sb_from_disk(&sb, XFS_BUF_TO_SBP(bp), false);
> + __xfs_sb_from_disk(&sb, bp->b_addr, false);
why not dsb here
> error = xfs_validate_sb_common(mp, bp, &sb);
> if (error)
> goto out_error;
> @@ -730,7 +730,7 @@ static void
> xfs_sb_quiet_read_verify(
> struct xfs_buf *bp)
> {
> - struct xfs_dsb *dsb = XFS_BUF_TO_SBP(bp);
> + struct xfs_dsb *dsb = bp->b_addr;
>
> if (dsb->sb_magicnum == cpu_to_be32(XFS_SB_MAGIC)) {
> /* XFS filesystem, verify noisily! */
> @@ -748,13 +748,14 @@ xfs_sb_write_verify(
> struct xfs_sb sb;
> struct xfs_mount *mp = bp->b_mount;
> struct xfs_buf_log_item *bip = bp->b_log_item;
> + struct xfs_dsb *dsb = bp->b_addr;
> int error;
>
> /*
> * Check all the superblock fields. Don't byteswap the xquota flags
> * because _verify_common checks the on-disk values.
> */
> - __xfs_sb_from_disk(&sb, XFS_BUF_TO_SBP(bp), false);
> + __xfs_sb_from_disk(&sb, dsb, false);
(as you did here)
> error = xfs_validate_sb_common(mp, bp, &sb);
> if (error)
> goto out_error;
> @@ -766,7 +767,7 @@ xfs_sb_write_verify(
> return;
>
> if (bip)
> - XFS_BUF_TO_SBP(bp)->sb_lsn = cpu_to_be64(bip->bli_item.li_lsn);
> + dsb->sb_lsn = cpu_to_be64(bip->bli_item.li_lsn);
>
> xfs_buf_update_cksum(bp, XFS_SB_CRC_OFF);
> return;
> @@ -927,7 +928,7 @@ xfs_log_sb(
> mp->m_sb.sb_ifree = percpu_counter_sum(&mp->m_ifree);
> mp->m_sb.sb_fdblocks = percpu_counter_sum(&mp->m_fdblocks);
>
> - xfs_sb_to_disk(XFS_BUF_TO_SBP(bp), &mp->m_sb);
> + xfs_sb_to_disk(bp->b_addr, &mp->m_sb);
hm no "dsb" in this case ...
In any case seems like if you already have a local xfs_dsb, use that vs. bp->b_addr?
-Eric
