Re: [PATCH 1/3] xfs: move kernel-specific superblock validation out of libxfs

Brian Foster
2020-12-01T16:18:46Z

On Mon, Nov 30, 2020 at 07:37:25PM -0800, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@oracle.com>
>
> A couple of the superblock validation checks apply only to the kernel,
> so move them to xfs_mount.c before we start changing sb_inprogress.
> This also reduces the diff between kernel and userspace libxfs.
>
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
> ---

Reviewed-by: Brian Foster <bfoster@redhat.com>

> fs/xfs/libxfs/xfs_sb.c | 23 ++++-------------------
> fs/xfs/libxfs/xfs_sb.h | 3 +++
> fs/xfs/xfs_mount.c | 31 +++++++++++++++++++++++++++++++
> 3 files changed, 38 insertions(+), 19 deletions(-)
>
>
> diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c
> index 5aeafa59ed27..a2c43fe38f64 100644
> --- a/fs/xfs/libxfs/xfs_sb.c
> +++ b/fs/xfs/libxfs/xfs_sb.c
> @@ -223,6 +223,7 @@ xfs_validate_sb_common(
> struct xfs_dsb *dsb = bp->b_addr;
> uint32_t agcount = 0;
> uint32_t rem;
> + int error;
>
> if (!xfs_verify_magic(bp, dsb->sb_magicnum)) {
> xfs_warn(mp, "bad magic number");
> @@ -382,16 +383,9 @@ xfs_validate_sb_common(
> return -EFSCORRUPTED;
> }
>
> - /*
> - * Until this is fixed only page-sized or smaller data blocks work.
> - */
> - if (unlikely(sbp->sb_blocksize > PAGE_SIZE)) {
> - xfs_warn(mp,
> - "File system with blocksize %d bytes. "
> - "Only pagesize (%ld) or less will currently work.",
> - sbp->sb_blocksize, PAGE_SIZE);
> - return -ENOSYS;
> - }
> + error = xfs_sb_validate_mount(mp, bp, sbp);
> + if (error)
> + return error;
>
> /*
> * Currently only very few inode sizes are supported.
> @@ -415,15 +409,6 @@ xfs_validate_sb_common(
> return -EFBIG;
> }
>
> - /*
> - * Don't touch the filesystem if a user tool thinks it owns the primary
> - * superblock. mkfs doesn't clear the flag from secondary supers, so
> - * we don't check them at all.
> - */
> - if (XFS_BUF_ADDR(bp) == XFS_SB_DADDR && sbp->sb_inprogress) {
> - xfs_warn(mp, "Offline file system operation in progress!");
> - return -EFSCORRUPTED;
> - }
> return 0;
> }
>
> diff --git a/fs/xfs/libxfs/xfs_sb.h b/fs/xfs/libxfs/xfs_sb.h
> index 92465a9a5162..ee0a5858dd47 100644
> --- a/fs/xfs/libxfs/xfs_sb.h
> +++ b/fs/xfs/libxfs/xfs_sb.h
> @@ -42,4 +42,7 @@ extern int xfs_sb_get_secondary(struct xfs_mount *mp,
> struct xfs_trans *tp, xfs_agnumber_t agno,
> struct xfs_buf **bpp);
>
> +int xfs_sb_validate_mount(struct xfs_mount *mp, struct xfs_buf *bp,
> + struct xfs_sb *sbp);
> +
> #endif /* __XFS_SB_H__ */
> diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
> index 7110507a2b6b..7bc7901d648d 100644
> --- a/fs/xfs/xfs_mount.c
> +++ b/fs/xfs/xfs_mount.c
> @@ -259,6 +259,37 @@ xfs_initialize_perag(
> return error;
> }
>
> +/* Validate the superblock is compatible with this mount. */
> +int
> +xfs_sb_validate_mount(
> + struct xfs_mount *mp,
> + struct xfs_buf *bp,
> + struct xfs_sb *sbp)
> +{
> + /*
> + * Don't touch the filesystem if a user tool thinks it owns the primary
> + * superblock. mkfs doesn't clear the flag from secondary supers, so
> + * we don't check them at all.
> + */
> + if (XFS_BUF_ADDR(bp) == XFS_SB_DADDR && sbp->sb_inprogress) {
> + xfs_warn(mp, "Offline file system operation in progress!");
> + return -EFSCORRUPTED;
> + }
> +
> + /*
> + * Until this is fixed only page-sized or smaller data blocks work.
> + */
> + if (unlikely(sbp->sb_blocksize > PAGE_SIZE)) {
> + xfs_warn(mp,
> + "File system with blocksize %d bytes. "
> + "Only pagesize (%ld) or less will currently work.",
> + sbp->sb_blocksize, PAGE_SIZE);
> + return -ENOSYS;
> + }
> +
> + return 0;
> +}
> +
> /*
> * xfs_readsb
> *
>