Commit 91a48aaf authored by Kemeng Shi's avatar Kemeng Shi Committed by Theodore Ts'o
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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: default avatarKemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: default avatarRitesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230311170949.1047958-3-shikemeng@huaweicloud.com


Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent 1221b235

fs/ext4/mballoc.c

+3 −5
Original line number Diff line number Diff line
@@ -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);