From: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
To: Kemeng Shi <shikemeng@huaweicloud.com>,
tytso@mit.edu, adilger.kernel@dilger.ca
Cc: linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org,
shikemeng@huaweicloud.com
Subject: Re: [PATCH 2/2] ext4: avoid unnecessary pointer dereference in ext4_mb_normalize_request
Date: Mon, 13 Mar 2023 07:43:42 +0530 [thread overview]
Message-ID: <87pm9dflex.fsf@doe.com> (raw)
In-Reply-To: <20230311170949.1047958-3-shikemeng@huaweicloud.com>
Kemeng Shi <shikemeng@huaweicloud.com> writes:
> 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>
> ---
> fs/ext4/mballoc.c | 8 +++-----
> 1 file changed, 3 insertions(+), 5 deletions(-)
>
Looks good to me. Please feel free to add -
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
> diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
> index 13dce6f07fa4..d94eb52dda17 100644
> --- 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);
> --
> 2.30.0
next prev parent reply other threads:[~2023-03-13 2:13 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-11 17:09 [PATCH 0/2] two cleanups for mballoc Kemeng Shi
2023-03-11 17:09 ` [PATCH 1/2] ext4: fix typos in mballoc Kemeng Shi
2023-03-13 2:12 ` Ritesh Harjani
2023-03-11 17:09 ` [PATCH 2/2] ext4: avoid unnecessary pointer dereference in ext4_mb_normalize_request Kemeng Shi
2023-03-13 2:13 ` Ritesh Harjani [this message]
2023-03-17 1:52 ` [PATCH 0/2] two cleanups for mballoc Theodore Ts'o
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