From 05b7c8ab2be71e6fef4615451e7af1bc79ffdf29 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 29 Aug 2017 15:44:12 -0700 Subject: xfs: move some code around inside xfs_bmap_shift_extents For the first right move we need to look up next_fsb. That means our last fsb that contains next_fsb must also be the current extent, so take advantage of that by moving the code around a bit. Signed-off-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/xfs/libxfs/xfs_bmap.c | 54 ++++++++++++++++++++++++++---------------------- 1 file changed, 29 insertions(+), 25 deletions(-) (limited to 'fs/xfs') diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c index 99b5fa5c4b8d..e529bed6be41 100644 --- a/fs/xfs/libxfs/xfs_bmap.c +++ b/fs/xfs/libxfs/xfs_bmap.c @@ -6127,7 +6127,6 @@ xfs_bmap_shift_extents( ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL)); ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL)); ASSERT(direction == SHIFT_LEFT || direction == SHIFT_RIGHT); - ASSERT(*next_fsb != NULLFSBLOCK || direction == SHIFT_RIGHT); ifp = XFS_IFORK_PTR(ip, whichfork); if (!(ifp->if_flags & XFS_IFEXTENTS)) { @@ -6159,43 +6158,48 @@ xfs_bmap_shift_extents( * In case of first right shift, we need to initialize next_fsb */ if (*next_fsb == NULLFSBLOCK) { - gotp = xfs_iext_get_ext(ifp, total_extents - 1); + ASSERT(direction == SHIFT_RIGHT); + + current_ext = total_extents - 1; + gotp = xfs_iext_get_ext(ifp, current_ext); xfs_bmbt_get_all(gotp, &got); *next_fsb = got.br_startoff; if (stop_fsb > *next_fsb) { *done = 1; goto del_cursor; } + } else { + /* + * Look up the extent index for the fsb where we start shifting. We can + * henceforth iterate with current_ext as extent list changes are locked + * out via ilock. + * + * gotp can be null in 2 cases: 1) if there are no extents or 2) + * *next_fsb lies in a hole beyond which there are no extents. Either + * way, we are done. + */ + gotp = xfs_iext_bno_to_ext(ifp, *next_fsb, ¤t_ext); + if (!gotp) { + *done = 1; + goto del_cursor; + } } /* Lookup the extent index at which we have to stop */ if (direction == SHIFT_RIGHT) { - gotp = xfs_iext_bno_to_ext(ifp, stop_fsb, &stop_extent); + xfs_iext_bno_to_ext(ifp, stop_fsb, &stop_extent); /* Make stop_extent exclusive of shift range */ stop_extent--; - } else + if (current_ext <= stop_extent) { + error = -EIO; + goto del_cursor; + } + } else { stop_extent = total_extents; - - /* - * Look up the extent index for the fsb where we start shifting. We can - * henceforth iterate with current_ext as extent list changes are locked - * out via ilock. - * - * gotp can be null in 2 cases: 1) if there are no extents or 2) - * *next_fsb lies in a hole beyond which there are no extents. Either - * way, we are done. - */ - gotp = xfs_iext_bno_to_ext(ifp, *next_fsb, ¤t_ext); - if (!gotp) { - *done = 1; - goto del_cursor; - } - - /* some sanity checking before we finally start shifting extents */ - if ((direction == SHIFT_LEFT && current_ext >= stop_extent) || - (direction == SHIFT_RIGHT && current_ext <= stop_extent)) { - error = -EIO; - goto del_cursor; + if (current_ext >= stop_extent) { + error = -EIO; + goto del_cursor; + } } while (nexts++ < num_exts) { -- cgit v1.2.3