On Tue, Oct 08, 2019 at 09:15:17AM +0200, Christoph Hellwig wrote:
> Now that xfs_file_unshare is not completely dumb we can just call it
> directly without iterating the extent and reflink btrees ourselves.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Looks ok,
Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
--D
> ---
> fs/xfs/xfs_reflink.c | 103 +++----------------------------------------
> 1 file changed, 5 insertions(+), 98 deletions(-)
>
> diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
> index a9634110c783..7fc728a8852b 100644
> --- a/fs/xfs/xfs_reflink.c
> +++ b/fs/xfs/xfs_reflink.c
> @@ -1381,85 +1381,6 @@ xfs_reflink_remap_prep(
> return ret;
> }
>
> -/*
> - * The user wants to preemptively CoW all shared blocks in this file,
> - * which enables us to turn off the reflink flag. Iterate all
> - * extents which are not prealloc/delalloc to see which ranges are
> - * mentioned in the refcount tree, then read those blocks into the
> - * pagecache, dirty them, fsync them back out, and then we can update
> - * the inode flag. What happens if we run out of memory? :)
> - */
> -STATIC int
> -xfs_reflink_dirty_extents(
> - struct xfs_inode *ip,
> - xfs_fileoff_t fbno,
> - xfs_filblks_t end,
> - xfs_off_t isize)
> -{
> - struct xfs_mount *mp = ip->i_mount;
> - xfs_agnumber_t agno;
> - xfs_agblock_t agbno;
> - xfs_extlen_t aglen;
> - xfs_agblock_t rbno;
> - xfs_extlen_t rlen;
> - xfs_off_t fpos;
> - xfs_off_t flen;
> - struct xfs_bmbt_irec map[2];
> - int nmaps;
> - int error = 0;
> -
> - 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);
> - if (error)
> - goto out;
> - if (nmaps == 0)
> - break;
> - if (!xfs_bmap_is_real_extent(&map[0]))
> - goto next;
> -
> - map[1] = map[0];
> - while (map[1].br_blockcount) {
> - agno = XFS_FSB_TO_AGNO(mp, map[1].br_startblock);
> - agbno = XFS_FSB_TO_AGBNO(mp, map[1].br_startblock);
> - aglen = map[1].br_blockcount;
> -
> - error = xfs_reflink_find_shared(mp, NULL, agno, agbno,
> - aglen, &rbno, &rlen, true);
> - if (error)
> - goto out;
> - if (rbno == NULLAGBLOCK)
> - break;
> -
> - /* Dirty the pages */
> - xfs_iunlock(ip, XFS_ILOCK_EXCL);
> - fpos = XFS_FSB_TO_B(mp, map[1].br_startoff +
> - (rbno - agbno));
> - flen = XFS_FSB_TO_B(mp, rlen);
> - if (fpos + flen > isize)
> - flen = isize - fpos;
> - error = iomap_file_unshare(VFS_I(ip), fpos, flen,
> - &xfs_iomap_ops);
> - xfs_ilock(ip, XFS_ILOCK_EXCL);
> - if (error)
> - goto out;
> -
> - map[1].br_blockcount -= (rbno - agbno + rlen);
> - map[1].br_startoff += (rbno - agbno + rlen);
> - map[1].br_startblock += (rbno - agbno + rlen);
> - }
> -
> -next:
> - fbno = map[0].br_startoff + map[0].br_blockcount;
> - }
> -out:
> - return error;
> -}
> -
> /* Does this inode need the reflink flag? */
> int
> xfs_reflink_inode_has_shared_extents(
> @@ -1596,10 +1517,7 @@ xfs_reflink_unshare(
> xfs_off_t offset,
> xfs_off_t len)
> {
> - struct xfs_mount *mp = ip->i_mount;
> - xfs_fileoff_t fbno;
> - xfs_filblks_t end;
> - xfs_off_t isize;
> + struct inode *inode = VFS_I(ip);
> int error;
>
> if (!xfs_is_reflink_inode(ip))
> @@ -1607,20 +1525,12 @@ xfs_reflink_unshare(
>
> trace_xfs_reflink_unshare(ip, offset, len);
>
> - inode_dio_wait(VFS_I(ip));
> + inode_dio_wait(inode);
>
> - /* Try to CoW the selected ranges */
> - xfs_ilock(ip, XFS_ILOCK_EXCL);
> - fbno = XFS_B_TO_FSBT(mp, offset);
> - isize = i_size_read(VFS_I(ip));
> - end = XFS_B_TO_FSB(mp, offset + len);
> - error = xfs_reflink_dirty_extents(ip, fbno, end, isize);
> + error = iomap_file_unshare(inode, offset, len, &xfs_iomap_ops);
> if (error)
> - goto out_unlock;
> - xfs_iunlock(ip, XFS_ILOCK_EXCL);
> -
> - /* Wait for the IO to finish */
> - error = filemap_write_and_wait(VFS_I(ip)->i_mapping);
> + goto out;
> + error = filemap_write_and_wait(inode->i_mapping);
> if (error)
> goto out;
>
> @@ -1628,11 +1538,8 @@ xfs_reflink_unshare(
> error = xfs_reflink_try_clear_inode_flag(ip);
> if (error)
> goto out;
> -
> return 0;
>
> -out_unlock:
> - xfs_iunlock(ip, XFS_ILOCK_EXCL);
> out:
> trace_xfs_reflink_unshare_error(ip, error, _RET_IP_);
> return error;
> --
> 2.20.1
>
