reuse-path-object-in-ext4_ext_shift_extents

   1 ext4: reuse path object in ext4_ext_shift_extents()
   2
   3 Now that the semantics of ext4_ext_find_extent() are much cleaner,
   4 it's safe and more efficient to reuse the path object across the
   5 multiple calls to ext4_ext_find_extent() in ext4_ext_shift_extents().
   6
   7 Signed-off-by: Theodore Ts'o <tytso@mit.edu>
   8 ---
   9  fs/ext4/extents.c | 25 ++++++++-----------------
  10  1 file changed, 8 insertions(+), 17 deletions(-)
  11
  12 diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
  13 index ecd86e0..ad76d41 100644
  14 --- a/fs/ext4/extents.c
  15 +++ b/fs/ext4/extents.c
  16 @@ -5305,26 +5305,21 @@ ext4_ext_shift_extents(struct inode *inode, handle_t *handle,
  17
  18         depth = path->p_depth;
  19         extent = path[depth].p_ext;
  20 -       if (!extent) {
  21 -               ext4_ext_drop_refs(path);
  22 -               kfree(path);
  23 -               return ret;
  24 -       }
  25 +       if (!extent)
  26 +               goto out;
  27
  28         stop_block = le32_to_cpu(extent->ee_block) +
  29                         ext4_ext_get_actual_len(extent);
  30 -       ext4_ext_drop_refs(path);
  31 -       kfree(path);
  32
  33         /* Nothing to shift, if hole is at the end of file */
  34         if (start >= stop_block)
  35 -               return ret;
  36 +               goto out;
  37
  38         /*
  39          * Don't start shifting extents until we make sure the hole is big
  40          * enough to accomodate the shift.
  41          */
  42 -       path = ext4_ext_find_extent(inode, start - 1, NULL, 0);
  43 +       path = ext4_ext_find_extent(inode, start - 1, &path, 0);
  44         if (IS_ERR(path))
  45                 return PTR_ERR(path);
  46         depth = path->p_depth;
  47 @@ -5337,8 +5332,6 @@ ext4_ext_shift_extents(struct inode *inode, handle_t *handle,
  48                 ex_start = 0;
  49                 ex_end = 0;
  50         }
  51 -       ext4_ext_drop_refs(path);
  52 -       kfree(path);
  53
  54         if ((start == ex_start && shift > ex_start) ||
  55             (shift > start - ex_end))
  56 @@ -5346,7 +5339,7 @@ ext4_ext_shift_extents(struct inode *inode, handle_t *handle,
  57
  58         /* Its safe to start updating extents */
  59         while (start < stop_block) {
  60 -               path = ext4_ext_find_extent(inode, start, NULL, 0);
  61 +               path = ext4_ext_find_extent(inode, start, &path, 0);
  62                 if (IS_ERR(path))
  63                         return PTR_ERR(path);
  64                 depth = path->p_depth;
  65 @@ -5362,19 +5355,17 @@ ext4_ext_shift_extents(struct inode *inode, handle_t *handle,
  66                                 path[depth].p_ext++;
  67                         } else {
  68                                 start = ext4_ext_next_allocated_block(path);
  69 -                               ext4_ext_drop_refs(path);
  70 -                               kfree(path);
  71                                 continue;
  72                         }
  73                 }
  74                 ret = ext4_ext_shift_path_extents(path, shift, inode,
  75                                 handle, &start);
  76 -               ext4_ext_drop_refs(path);
  77 -               kfree(path);
  78                 if (ret)
  79                         break;
  80         }
  81 -
  82 +out:
  83 +       ext4_ext_drop_refs(path);
  84 +       kfree(path);
  85         return ret;
  86  }
  87