ext4: avoid unnecessary pointer dereference in ext4_mb_normalize_request

Result of EXT4_SB(ac->ac_sb) is already stored in sbi at beginning of
ext4_mb_normalize_request. Use sbi instead of EXT4_SB(ac->ac_sb) to
remove unnecessary pointer dereference.

Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230311170949.1047958-3-shikemeng@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 0b03a3b90207120dbdf046022fbe89320adf4b4f..05a1f19c925bb0087359a7099c1abba53dd9e0d0 100644 (file)
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -4049,7 +4049,7 @@ ext4_mb_normalize_request(struct ext4_allocation_context *ac,
                size = 8 * 1024 * 1024;
        } else {
                start_off = (loff_t) ac->ac_o_ex.fe_logical << bsbits;
-               size      = (loff_t) EXT4_C2B(EXT4_SB(ac->ac_sb),
+               size      = (loff_t) EXT4_C2B(sbi,
                                              ac->ac_o_ex.fe_len) << bsbits;
        }
        size = size >> bsbits;
@@ -4094,8 +4094,7 @@ ext4_mb_normalize_request(struct ext4_allocation_context *ac,
                        continue;
                }
 
-               pa_end = pa->pa_lstart + EXT4_C2B(EXT4_SB(ac->ac_sb),
-                                                 pa->pa_len);
+               pa_end = pa->pa_lstart + EXT4_C2B(sbi, pa->pa_len);
 
                /* PA must not overlap original request */
                BUG_ON(!(ac->ac_o_ex.fe_logical >= pa_end ||
@@ -4128,8 +4127,7 @@ ext4_mb_normalize_request(struct ext4_allocation_context *ac,
 
                spin_lock(&pa->pa_lock);
                if (pa->pa_deleted == 0) {
-                       pa_end = pa->pa_lstart + EXT4_C2B(EXT4_SB(ac->ac_sb),
-                                                         pa->pa_len);
+                       pa_end = pa->pa_lstart + EXT4_C2B(sbi, pa->pa_len);
                        BUG_ON(!(start >= pa_end || end <= pa->pa_lstart));
                }
                spin_unlock(&pa->pa_lock);