ext4: reuse path object in ext4_ext_shift_extents()

Now that the semantics of ext4_ext_find_extent() are much cleaner,
it's safe and more efficient to reuse the path object across the
multiple calls to ext4_ext_find_extent() in ext4_ext_shift_extents().

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

1 files changed, 8 insertions, 17 deletions

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index c94c7480053e..22828e44a70d 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -5306,26 +5306,21 @@ ext4_ext_shift_extents(struct inode *inode, handle_t *handle,
 
         depth = path->p_depth;
         extent = path[depth].p_ext;
-        if (!extent) {
-                ext4_ext_drop_refs(path);
-                kfree(path);
-                return ret;
-        }
+        if (!extent)
+                goto out;
 
         stop_block = le32_to_cpu(extent->ee_block) +
                         ext4_ext_get_actual_len(extent);
-        ext4_ext_drop_refs(path);
-        kfree(path);
 
         /* Nothing to shift, if hole is at the end of file */
         if (start >= stop_block)
-                return ret;
+                goto out;
 
         /*
          * Don't start shifting extents until we make sure the hole is big
          * enough to accomodate the shift.
          */
-        path = ext4_ext_find_extent(inode, start - 1, NULL, 0);
+        path = ext4_ext_find_extent(inode, start - 1, &path, 0);
         if (IS_ERR(path))
                 return PTR_ERR(path);
         depth = path->p_depth;
@@ -5338,8 +5333,6 @@ ext4_ext_shift_extents(struct inode *inode, handle_t *handle,
                 ex_start = 0;
                 ex_end = 0;
         }
-        ext4_ext_drop_refs(path);
-        kfree(path);
 
         if ((start == ex_start && shift > ex_start) ||
             (shift > start - ex_end))
@@ -5347,7 +5340,7 @@ ext4_ext_shift_extents(struct inode *inode, handle_t *handle,
 
         /* Its safe to start updating extents */
         while (start < stop_block) {
-                path = ext4_ext_find_extent(inode, start, NULL, 0);
+                path = ext4_ext_find_extent(inode, start, &path, 0);
                 if (IS_ERR(path))
                         return PTR_ERR(path);
                 depth = path->p_depth;
@@ -5363,19 +5356,17 @@ ext4_ext_shift_extents(struct inode *inode, handle_t *handle,
                                 path[depth].p_ext++;
                         } else {
                                 start = ext4_ext_next_allocated_block(path);
-                                ext4_ext_drop_refs(path);
-                                kfree(path);
                                 continue;
                         }
                 }
                 ret = ext4_ext_shift_path_extents(path, shift, inode,
                                 handle, &start);
-                ext4_ext_drop_refs(path);
-                kfree(path);
                 if (ret)
                         break;
         }
-
+out:
+        ext4_ext_drop_refs(path);
+        kfree(path);
         return ret;
 }