On Tue, Jun 06, 2017 at 06:26:46PM -0700, Darrick J. Wong wrote:
> Separate the "clear reflink flag" function into one function that checks
> if the flag is needed, and a second function that checks and clears the
> flag. The inode scrub code will want to check the necessity of the flag
> without clearing it.
>
> Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> ---
Reviewed-by: Brian Foster <bfoster@xxxxxxxxxx>
> fs/xfs/xfs_reflink.c | 88 ++++++++++++++++++++++++++++++--------------------
> fs/xfs/xfs_reflink.h | 2 +
> 2 files changed, 54 insertions(+), 36 deletions(-)
>
> diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
> index e25c995..ab2270a 100644
> --- a/fs/xfs/xfs_reflink.c
> +++ b/fs/xfs/xfs_reflink.c
> @@ -1406,57 +1406,73 @@ xfs_reflink_dirty_extents(
> return error;
> }
>
> -/* Clear the inode reflink flag if there are no shared extents. */
> +/* Does this inode need the reflink flag? */
> int
> -xfs_reflink_clear_inode_flag(
> - struct xfs_inode *ip,
> - struct xfs_trans **tpp)
> +xfs_reflink_inode_has_shared_extents(
> + struct xfs_trans *tp,
> + struct xfs_inode *ip,
> + bool *has_shared)
> {
> - struct xfs_mount *mp = ip->i_mount;
> - xfs_fileoff_t fbno;
> - xfs_filblks_t end;
> - xfs_agnumber_t agno;
> - xfs_agblock_t agbno;
> - xfs_extlen_t aglen;
> - xfs_agblock_t rbno;
> - xfs_extlen_t rlen;
> - struct xfs_bmbt_irec map;
> - int nmaps;
> - int error = 0;
> -
> - ASSERT(xfs_is_reflink_inode(ip));
> + struct xfs_bmbt_irec got;
> + struct xfs_mount *mp = ip->i_mount;
> + struct xfs_ifork *ifp;
> + xfs_agnumber_t agno;
> + xfs_agblock_t agbno;
> + xfs_extlen_t aglen;
> + xfs_agblock_t rbno;
> + xfs_extlen_t rlen;
> + xfs_extnum_t idx;
> + bool found;
> + int error;
>
> - fbno = 0;
> - end = XFS_B_TO_FSB(mp, i_size_read(VFS_I(ip)));
> - while (end - fbno > 0) {
> - nmaps = 1;
> - /*
> - * Look for extents in the file. Skip holes, delalloc, or
> - * unwritten extents; they can't be reflinked.
> - */
> - error = xfs_bmapi_read(ip, fbno, end - fbno, &map, &nmaps, 0);
> + ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
> + if (!(ifp->if_flags & XFS_IFEXTENTS)) {
> + error = xfs_iread_extents(tp, ip, XFS_DATA_FORK);
> if (error)
> return error;
> - if (nmaps == 0)
> - break;
> - if (!xfs_bmap_is_real_extent(&map))
> - goto next;
> + }
>
> - agno = XFS_FSB_TO_AGNO(mp, map.br_startblock);
> - agbno = XFS_FSB_TO_AGBNO(mp, map.br_startblock);
> - aglen = map.br_blockcount;
> + *has_shared = false;
> + found = xfs_iext_lookup_extent(ip, ifp, 0, &idx, &got);
> + while (found) {
> + if (isnullstartblock(got.br_startblock) ||
> + got.br_state != XFS_EXT_NORM)
> + goto next;
> + agno = XFS_FSB_TO_AGNO(mp, got.br_startblock);
> + agbno = XFS_FSB_TO_AGBNO(mp, got.br_startblock);
> + aglen = got.br_blockcount;
>
> - error = xfs_reflink_find_shared(mp, *tpp, agno, agbno, aglen,
> + error = xfs_reflink_find_shared(mp, tp, agno, agbno, aglen,
> &rbno, &rlen, false);
> if (error)
> return error;
> /* Is there still a shared block here? */
> - if (rbno != NULLAGBLOCK)
> + if (rbno != NULLAGBLOCK) {
> + *has_shared = true;
> return 0;
> + }
> next:
> - fbno = map.br_startoff + map.br_blockcount;
> + found = xfs_iext_get_extent(ifp, ++idx, &got);
> }
>
> + return 0;
> +}
> +
> +/* Clear the inode reflink flag if there are no shared extents. */
> +int
> +xfs_reflink_clear_inode_flag(
> + struct xfs_inode *ip,
> + struct xfs_trans **tpp)
> +{
> + bool needs_flag;
> + int error = 0;
> +
> + ASSERT(xfs_is_reflink_inode(ip));
> +
> + error = xfs_reflink_inode_has_shared_extents(*tpp, ip, &needs_flag);
> + if (error || needs_flag)
> + return error;
> +
> /*
> * We didn't find any shared blocks so turn off the reflink flag.
> * First, get rid of any leftover CoW mappings.
> diff --git a/fs/xfs/xfs_reflink.h b/fs/xfs/xfs_reflink.h
> index b8cc5c3..701487b 100644
> --- a/fs/xfs/xfs_reflink.h
> +++ b/fs/xfs/xfs_reflink.h
> @@ -47,6 +47,8 @@ extern int xfs_reflink_end_cow(struct xfs_inode *ip, xfs_off_t offset,
> extern int xfs_reflink_recover_cow(struct xfs_mount *mp);
> extern int xfs_reflink_remap_range(struct file *file_in, loff_t pos_in,
> struct file *file_out, loff_t pos_out, u64 len, bool is_dedupe);
> +extern int xfs_reflink_inode_has_shared_extents(struct xfs_trans *tp,
> + struct xfs_inode *ip, bool *has_shared);
> extern int xfs_reflink_clear_inode_flag(struct xfs_inode *ip,
> struct xfs_trans **tpp);
> extern int xfs_reflink_unshare(struct xfs_inode *ip, xfs_off_t offset,
> --
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