linux-ext4 - [PATCH v2 1/2] ext4: remove unused buddy_loaded in ext4_mb_seq_groups

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Message-Id: <20240118042557.380058-1-yangerkun@huawei.com>
Date: Thu, 18 Jan 2024 12:25:56 +0800
From: yangerkun <yangerkun@...wei.com>
To: tytso@....edu,
	adilger.kernel@...ger.ca,
	jack@...e.cz
Cc: linux-ext4@...r.kernel.org,
	yangerkun@...wei.com,
	yangerkun@...weicloud.com
Subject: [PATCH v2 1/2] ext4: remove unused buddy_loaded in ext4_mb_seq_groups_show

We can just first call ext4_mb_unload_buddy, then copy information from
ext4_group_info. So remove this unused value.

Signed-off-by: yangerkun <yangerkun@...wei.com>
Reviewed-by: Jan Kara <jack@...e.cz>
---
 fs/ext4/mballoc.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

v1->v2:
Add comments before memcpy, add review tag.

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index f44f668e407f..866f8f0922f1 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2990,8 +2990,7 @@ static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v)
 {
 	struct super_block *sb = pde_data(file_inode(seq->file));
 	ext4_group_t group = (ext4_group_t) ((unsigned long) v);
-	int i;
-	int err, buddy_loaded = 0;
+	int i, err;
 	struct ext4_buddy e4b;
 	struct ext4_group_info *grinfo;
 	unsigned char blocksize_bits = min_t(unsigned char,
@@ -3021,14 +3020,14 @@ static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v)
 			seq_printf(seq, "#%-5u: I/O error\n", group);
 			return 0;
 		}
-		buddy_loaded = 1;
+		ext4_mb_unload_buddy(&e4b);
 	}
 
+	/*
+	 * We care only about free space counters in the group info and
+	 * these are safe to access even after the buddy has been unloaded
+	 */
 	memcpy(&sg, grinfo, i);
-
-	if (buddy_loaded)
-		ext4_mb_unload_buddy(&e4b);
-
 	seq_printf(seq, "#%-5u: %-5u %-5u %-5u [", group, sg.info.bb_free,
 			sg.info.bb_fragments, sg.info.bb_first_free);
 	for (i = 0; i <= 13; i++)
-- 
2.39.2