save-goal-location-struct-ext4_allocation_context.ac_g_ex

   1 ext4: save goal group and offset in struct ext4_allocation_context.ac_g_ex
   2
   3 From: Xiaoguang Wang <wangxg.fnst@cn.fujitsu.com>
   4
   5 In ext4_mb_normalize_request(), if ac_g_ex.fe_logical is adjacent to
   6 the closest logical allocated block to the left or if
   7 (ac_g_ex.fe_logical+len) adjacent to the closest logical allocated
   8 block to the right, we'll attach EXT4_MB_HINT_TRY_GOAL flag taking the
   9 physical block (ext4_allocation_request.lleft+1) or
  10 (ext4_allocation_request.pright-len) as a goal, and put this
  11 information in ext4_allocation_context.ac_f_ex.
  12
  13 But look at the ext4_mb_find_by_goal(), indeed it use ac_g_ex to look
  14 up, so this is wrong, we should save goal group and offset in struct
  15 ext4_allocation_context.ac_g_ex.
  16
  17 Signed-off-by: Xiaoguang Wang <wangxg.fnst@cn.fujitsu.com>
  18 Signed-off-by: Theodore Ts'o <tytso@mit.edu>
  19 ---
  20  fs/ext4/mballoc.c | 8 ++++----
  21  1 file changed, 4 insertions(+), 4 deletions(-)
  22
  23 diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
  24 index 2dcb936..6d939d79 100644
  25 --- a/fs/ext4/mballoc.c
  26 +++ b/fs/ext4/mballoc.c
  27 @@ -3168,15 +3168,15 @@ ext4_mb_normalize_request(struct ext4_allocation_context *ac,
  28         if (ar->pright && (ar->lright == (start + size))) {
  29                 /* merge to the right */
  30                 ext4_get_group_no_and_offset(ac->ac_sb, ar->pright - size,
  31 -                                               &ac->ac_f_ex.fe_group,
  32 -                                               &ac->ac_f_ex.fe_start);
  33 +                                               &ac->ac_g_ex.fe_group,
  34 +                                               &ac->ac_g_ex.fe_start);
  35                 ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL;
  36         }
  37         if (ar->pleft && (ar->lleft + 1 == start)) {
  38                 /* merge to the left */
  39                 ext4_get_group_no_and_offset(ac->ac_sb, ar->pleft + 1,
  40 -                                               &ac->ac_f_ex.fe_group,
  41 -                                               &ac->ac_f_ex.fe_start);
  42 +                                               &ac->ac_g_ex.fe_group,
  43 +                                               &ac->ac_g_ex.fe_start);
  44                 ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL;
  45         }
  46
  47 --
  48 1.8.2.1
  49
  50