xfs: cleanup xfs_bmse_shift_one goto mess

xfs_bmse_shift_one() jumps around determining whether to shift or
merge, making the code flow difficult to follow. Clean it up and
use direct error returns (including XFS_WANT_CORRUPTED_RETURN) to
make the code flow better and be easier to read.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

1 files changed, 17 insertions, 26 deletions

diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index 20d2e96aef6a..0628a678de12 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -5544,35 +5544,29 @@ xfs_bmse_shift_one(
         startoff = got.br_startoff - offset_shift_fsb;
 
         /* delalloc extents should be prevented by caller */
-        XFS_WANT_CORRUPTED_GOTO(!isnullstartblock(got.br_startblock),
-                                out_error);
+        XFS_WANT_CORRUPTED_RETURN(!isnullstartblock(got.br_startblock));
 
         /*
-         * If this is the first extent in the file, make sure there's enough
-         * room at the start of the file and jump right to the shift as there's
-         * no left extent to merge.
+         * Check for merge if we've got an extent to the left, otherwise make
+         * sure there's enough room at the start of the file for the shift.
          */
-        if (*current_ext == 0) {
-                if (got.br_startoff < offset_shift_fsb)
-                        return -EINVAL;
-                goto shift_extent;
-        }
+        if (*current_ext) {
+                /* grab the left extent and check for a large enough hole */
+                leftp = xfs_iext_get_ext(ifp, *current_ext - 1);
+                xfs_bmbt_get_all(leftp, &left);
 
-        /* grab the left extent and check for a large enough hole */
-        leftp = xfs_iext_get_ext(ifp, *current_ext - 1);
-        xfs_bmbt_get_all(leftp, &left);
+                if (startoff < left.br_startoff + left.br_blockcount)
+                        return -EINVAL;
 
-        if (startoff < left.br_startoff + left.br_blockcount)
+                /* check whether to merge the extent or shift it down */
+                if (xfs_bmse_can_merge(&left, &got, offset_shift_fsb)) {
+                        return xfs_bmse_merge(ip, whichfork, offset_shift_fsb,
+                                              *current_ext, gotp, leftp, cur,
+                                              logflags);
+                }
+        } else if (got.br_startoff < offset_shift_fsb)
                 return -EINVAL;
 
-        /* check whether to merge the extent or shift it down */
-        if (!xfs_bmse_can_merge(&left, &got, offset_shift_fsb))
-                goto shift_extent;
-
-        return xfs_bmse_merge(ip, whichfork, offset_shift_fsb, *current_ext,
-                              gotp, leftp, cur, logflags);
-
-shift_extent:
         /*
          * Increment the extent index for the next iteration, update the start
          * offset of the in-core extent and update the btree if applicable.
@@ -5589,14 +5583,11 @@ shift_extent:
                                    got.br_blockcount, &i);
         if (error)
                 return error;
-        XFS_WANT_CORRUPTED_GOTO(i == 1, out_error);
+        XFS_WANT_CORRUPTED_RETURN(i == 1);
 
         got.br_startoff = startoff;
         return xfs_bmbt_update(cur, got.br_startoff, got.br_startblock,
                                 got.br_blockcount, got.br_state);
-
-out_error:
-        return error;
 }
 
 /*