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>

diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index 20d2e96aef6a29c4257454a53cafad4872f4bf7c..0628a678de121e28b5b918976c4fe4e3919fcd4c 100644 (file)
--- 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;
 }
 
 /*