From: Baokun Li <libaokun1@huawei.com>
Date: Fri, 21 Nov 2025 09:06:36 +0000 (+0800)
Subject: ext4: introduce s_min_folio_order for future BS > PS support
X-Git-Tag: v6.19-rc1~161^2~19
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8611e608a8fa01e8b82c9008b4dac9f24531ae0f;p=thirdparty%2Fkernel%2Flinux.git

ext4: introduce s_min_folio_order for future BS > PS support

This commit introduces the s_min_folio_order field to the ext4_sb_info
structure. This field will store the minimum folio order required by the
current filesystem, laying groundwork for future support of block sizes
greater than PAGE_SIZE.

Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Pankaj Raghav <p.raghav@samsung.com>
Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Message-ID: <20251121090654.631996-7-libaokun@huaweicloud.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
---

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 6c2540e94c78a..0502afa6f6e5b 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1697,6 +1697,9 @@ struct ext4_sb_info {
 	/* record the last minlen when FITRIM is called. */
 	unsigned long s_last_trim_minblks;
 
+	/* minimum folio order of a page cache allocation */
+	unsigned int s_min_folio_order;
+
 	/* Precomputed FS UUID checksum for seeding other checksums */
 	__u32 s_csum_seed;
 
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 5cf392142c8ca..ff697adab5f65 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -5183,7 +5183,8 @@ void ext4_set_inode_mapping_order(struct inode *inode)
 	if (!ext4_should_enable_large_folio(inode))
 		return;
 
-	mapping_set_folio_order_range(inode->i_mapping, 0,
+	mapping_set_folio_order_range(inode->i_mapping,
+				      EXT4_SB(inode->i_sb)->s_min_folio_order,
 				      EXT4_MAX_PAGECACHE_ORDER(inode));
 }
 
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index f39679892e713..2286cd1e3cb83 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -5109,11 +5109,8 @@ static int ext4_load_super(struct super_block *sb, ext4_fsblk_t *lsb,
 	 * If the default block size is not the same as the real block size,
 	 * we need to reload it.
 	 */
-	if (sb->s_blocksize == blocksize) {
-		*lsb = logical_sb_block;
-		sbi->s_sbh = bh;
-		return 0;
-	}
+	if (sb->s_blocksize == blocksize)
+		goto success;
 
 	/*
 	 * bh must be released before kill_bdev(), otherwise
@@ -5144,6 +5141,9 @@ static int ext4_load_super(struct super_block *sb, ext4_fsblk_t *lsb,
 		ext4_msg(sb, KERN_ERR, "Magic mismatch, very weird!");
 		goto out;
 	}
+
+success:
+	sbi->s_min_folio_order = get_order(blocksize);
 	*lsb = logical_sb_block;
 	sbi->s_sbh = bh;
 	return 0;