On Mon, Sep 09, 2019 at 08:27:16PM +0200, Christoph Hellwig wrote:
> We have lots of places that want to calculate the final fsb for
> a offset + count in bytes and check that the result fits into
> s_maxbytes. Factor out a helper for that.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> ---
> fs/xfs/xfs_iomap.c | 40 ++++++++++++++++++++--------------------
> 1 file changed, 20 insertions(+), 20 deletions(-)
>
> diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
> index d12eacdc9bba..0ba67a8d8169 100644
> --- a/fs/xfs/xfs_iomap.c
> +++ b/fs/xfs/xfs_iomap.c
> @@ -102,6 +102,17 @@ xfs_hole_to_iomap(
> iomap->dax_dev = xfs_find_daxdev_for_inode(VFS_I(ip));
> }
>
> +static inline xfs_fileoff_t
> +xfs_iomap_end_fsb(
I wonder if this function ought to have a comment that it returns the
offset block number of offset + count clamped to the highest offset
supported by the page cache, but ... eh.
Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
--D
> + struct xfs_mount *mp,
> + loff_t offset,
> + loff_t count)
> +{
> + ASSERT(offset <= mp->m_super->s_maxbytes);
> + return min(XFS_B_TO_FSB(mp, offset + count),
> + XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes));
> +}
> +
> xfs_extlen_t
> xfs_eof_alignment(
> struct xfs_inode *ip,
> @@ -172,8 +183,8 @@ xfs_iomap_write_direct(
> int nmaps)
> {
> xfs_mount_t *mp = ip->i_mount;
> - xfs_fileoff_t offset_fsb;
> - xfs_fileoff_t last_fsb;
> + xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset);
> + xfs_fileoff_t last_fsb = xfs_iomap_end_fsb(mp, offset, count);
> xfs_filblks_t count_fsb, resaligned;
> xfs_extlen_t extsz;
> int nimaps;
> @@ -192,8 +203,6 @@ xfs_iomap_write_direct(
>
> ASSERT(xfs_isilocked(ip, lockmode));
>
> - offset_fsb = XFS_B_TO_FSBT(mp, offset);
> - last_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)(offset + count)));
> if ((offset + count) > XFS_ISIZE(ip)) {
> /*
> * Assert that the in-core extent list is present since this can
> @@ -533,9 +542,7 @@ xfs_file_iomap_begin_delay(
> struct xfs_inode *ip = XFS_I(inode);
> struct xfs_mount *mp = ip->i_mount;
> xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset);
> - xfs_fileoff_t maxbytes_fsb =
> - XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes);
> - xfs_fileoff_t end_fsb;
> + xfs_fileoff_t end_fsb = xfs_iomap_end_fsb(mp, offset, count);
> struct xfs_bmbt_irec imap, cmap;
> struct xfs_iext_cursor icur, ccur;
> xfs_fsblock_t prealloc_blocks = 0;
> @@ -565,8 +572,6 @@ xfs_file_iomap_begin_delay(
> goto out_unlock;
> }
>
> - end_fsb = min(XFS_B_TO_FSB(mp, offset + count), maxbytes_fsb);
> -
> /*
> * Search the data fork fork first to look up our source mapping. We
> * always need the data fork map, as we have to return it to the
> @@ -648,7 +653,7 @@ xfs_file_iomap_begin_delay(
> * the lower level functions are updated.
> */
> count = min_t(loff_t, count, 1024 * PAGE_SIZE);
> - end_fsb = min(XFS_B_TO_FSB(mp, offset + count), maxbytes_fsb);
> + end_fsb = xfs_iomap_end_fsb(mp, offset, count);
>
> if (xfs_is_always_cow_inode(ip))
> whichfork = XFS_COW_FORK;
> @@ -674,7 +679,8 @@ xfs_file_iomap_begin_delay(
> if (align)
> p_end_fsb = roundup_64(p_end_fsb, align);
>
> - p_end_fsb = min(p_end_fsb, maxbytes_fsb);
> + p_end_fsb = min(p_end_fsb,
> + XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes));
> ASSERT(p_end_fsb > offset_fsb);
> prealloc_blocks = p_end_fsb - end_fsb;
> }
> @@ -937,7 +943,8 @@ xfs_file_iomap_begin(
> struct xfs_inode *ip = XFS_I(inode);
> struct xfs_mount *mp = ip->i_mount;
> struct xfs_bmbt_irec imap, cmap;
> - xfs_fileoff_t offset_fsb, end_fsb;
> + xfs_fileoff_t offset_fsb = XFS_B_TO_FSBT(mp, offset);
> + xfs_fileoff_t end_fsb = xfs_iomap_end_fsb(mp, offset, length);
> int nimaps = 1, error = 0;
> bool shared = false;
> u16 iomap_flags = 0;
> @@ -963,12 +970,6 @@ xfs_file_iomap_begin(
> if (error)
> return error;
>
> - ASSERT(offset <= mp->m_super->s_maxbytes);
> - if (offset > mp->m_super->s_maxbytes - length)
> - length = mp->m_super->s_maxbytes - offset;
> - offset_fsb = XFS_B_TO_FSBT(mp, offset);
> - end_fsb = XFS_B_TO_FSB(mp, offset + length);
> -
> error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, &imap,
> &nimaps, 0);
> if (error)
> @@ -1189,8 +1190,7 @@ xfs_seek_iomap_begin(
> /*
> * Fake a hole until the end of the file.
> */
> - data_fsb = min(XFS_B_TO_FSB(mp, offset + length),
> - XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes));
> + data_fsb = xfs_iomap_end_fsb(mp, offset, length);
> }
>
> /*
> --
> 2.20.1
>
