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To:     adilger.kernel@dilger.ca, tytso@mit.edu, linux-ext4@vger.kernel.org
From:   brookxu <brookxu.cn@gmail.com>
Subject: [PATCH v2] ext4: delete invalid ac_b_extent backup inside
 ext4_mb_use_best_found()
Message-ID: <0c77de22-c0d0-4c1b-645a-865bcd2edc0a@gmail.com>
Date:   Fri, 7 Aug 2020 19:32:20 +0800
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Sender: linux-ext4-owner@vger.kernel.org
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Delete invalid ac_b_extent backup inside ext4_mb_use_best_found(),
we have done this operation in ext4_mb_new_group_pa() and
ext4_mb_new_inode_pa().

Signed-off-by: Chunguang Xu <brookxu@tencent.com>

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 9b1c3ad..fb63e9f 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -1704,10 +1704,6 @@ static void ext4_mb_use_best_found(struct ext4_allocation_context *ac,
 	ac->ac_b_ex.fe_logical = ac->ac_g_ex.fe_logical;
 	ret = mb_mark_used(e4b, &ac->ac_b_ex);
 
-	/* preallocation can change ac_b_ex, thus we store actually
-	 * allocated blocks for history */
-	ac->ac_f_ex = ac->ac_b_ex;
-
 	ac->ac_status = AC_STATUS_FOUND;
 	ac->ac_tail = ret & 0xffff;
 	ac->ac_buddy = ret >> 16;
@@ -1726,8 +1722,8 @@ static void ext4_mb_use_best_found(struct ext4_allocation_context *ac,
 	/* store last allocated for subsequent stream allocation */
 	if (ac->ac_flags & EXT4_MB_STREAM_ALLOC) {
 		spin_lock(&sbi->s_md_lock);
-		sbi->s_mb_last_group = ac->ac_f_ex.fe_group;
-		sbi->s_mb_last_start = ac->ac_f_ex.fe_start;
+		sbi->s_mb_last_group = ac->ac_b_ex.fe_group;
+		sbi->s_mb_last_start = ac->ac_b_ex.fe_start;
 		spin_unlock(&sbi->s_md_lock);
 	}
 	/*
-- 
1.8.3.1