linux-ext4 - [PATCH] ext4: Add correct group descriptors and reserved GDT blocks to system zone

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Message-ID: <tencent_4A474CC049B9E77D0F172468991EED5B9105@qq.com>
Date:   Sun,  4 Jun 2023 00:33:50 +0800
From:   Wang Jianjian <wangjianjian0@...mail.com>
To:     linux-ext4@...r.kernel.org, tytso@....edu
Cc:     wangjianjian0@...mail.com
Subject: [PATCH] ext4: Add correct group descriptors and reserved GDT blocks to system zone

When setup_system_zone, flex_bg is not initialzied so it is always 1.
and when meta_bg enabled, group descriptors are located in the first,
second, and the last group of meta group.
And this patch also adds reserved GDT blocks to system zone.

Signed-off-by: Wang Jianjian <wangjianjian0@...mail.com>
---
 fs/ext4/block_validity.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/fs/ext4/block_validity.c b/fs/ext4/block_validity.c
index 5504f72bbbbe..5df357763975 100644
--- a/fs/ext4/block_validity.c
+++ b/fs/ext4/block_validity.c
@@ -215,7 +215,6 @@ int ext4_setup_system_zone(struct super_block *sb)
 	struct ext4_system_blocks *system_blks;
 	struct ext4_group_desc *gdp;
 	ext4_group_t i;
-	int flex_size = ext4_flex_bg_size(sbi);
 	int ret;
 
 	system_blks = kzalloc(sizeof(*system_blks), GFP_KERNEL);
@@ -224,11 +223,14 @@ int ext4_setup_system_zone(struct super_block *sb)
 
 	for (i=0; i < ngroups; i++) {
 		cond_resched();
-		if (ext4_bg_has_super(sb, i) &&
-		    ((i < 5) || ((i % flex_size) == 0))) {
+		unsigned int sb_num = ext4_bg_has_super(sb, i);
+		unsigned long gdb_num = ext4_bg_num_gdb(sb, i);
+		unsigned int rsvd_gdt = le16_to_cpu(sbi->es->s_reserved_gdt_blocks);
+
+		if (sb_num != 0 || gdb_num != 0) {
 			ret = add_system_zone(system_blks,
 					ext4_group_first_block_no(sb, i),
-					ext4_bg_num_gdb(sb, i) + 1, 0);
+					sb_num + gdb_num + rsvd_gdt, 0);
 			if (ret)
 				goto err;
 		}
-- 
2.34.3