From cab8cbcb923a89cb583c9088fa50431eb2feded5 Mon Sep 17 00:00:00 2001 From: Baokun Li Date: Fri, 21 Nov 2025 17:06:54 +0800 Subject: [PATCH] ext4: enable block size larger than page size Since block device (See commit 3c20917120ce ("block/bdev: enable large folio support for large logical block sizes")) and page cache (See commit ab95d23bab220ef8 ("filemap: allocate mapping_min_order folios in the page cache")) has the ability to have a minimum order when allocating folio, and ext4 has supported large folio in commit 7ac67301e82f ("ext4: enable large folio for regular file"), now add support for block_size > PAGE_SIZE in ext4. set_blocksize() -> bdev_validate_blocksize() already validates the block size, so ext4_load_super() does not need to perform additional checks. Here we only need to add the FS_LBS bit to fs_flags. In addition, block sizes larger than the page size are currently supported only when CONFIG_TRANSPARENT_HUGEPAGE is enabled. To make this explicit, a blocksize_gt_pagesize entry has been added under /sys/fs/ext4/feature/, indicating whether bs > ps is supported. This allows mke2fs to check the interface and determine whether a warning should be issued when formatting a filesystem with block size larger than the page size. Suggested-by: Theodore Ts'o Signed-off-by: Baokun Li Reviewed-by: Zhang Yi Reviewed-by: Jan Kara Reviewed-by: Pankaj Raghav Reviewed-by: Ojaswin Mujoo Message-ID: <20251121090654.631996-25-libaokun@huaweicloud.com> Signed-off-by: Theodore Ts'o --- fs/ext4/super.c | 3 ++- fs/ext4/sysfs.c | 6 ++++++ 2 files changed, 8 insertions(+), 1 deletion(-) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 3d03a6eb0ea0..87205660c5d0 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -7453,7 +7453,8 @@ static struct file_system_type ext4_fs_type = { .init_fs_context = ext4_init_fs_context, .parameters = ext4_param_specs, .kill_sb = ext4_kill_sb, - .fs_flags = FS_REQUIRES_DEV | FS_ALLOW_IDMAP | FS_MGTIME, + .fs_flags = FS_REQUIRES_DEV | FS_ALLOW_IDMAP | FS_MGTIME | + FS_LBS, }; MODULE_ALIAS_FS("ext4"); diff --git a/fs/ext4/sysfs.c b/fs/ext4/sysfs.c index 987bd00f916a..0018e09b867e 100644 --- a/fs/ext4/sysfs.c +++ b/fs/ext4/sysfs.c @@ -332,6 +332,9 @@ EXT4_ATTR_FEATURE(fast_commit); #if IS_ENABLED(CONFIG_UNICODE) && defined(CONFIG_FS_ENCRYPTION) EXT4_ATTR_FEATURE(encrypted_casefold); #endif +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +EXT4_ATTR_FEATURE(blocksize_gt_pagesize); +#endif static struct attribute *ext4_feat_attrs[] = { ATTR_LIST(lazy_itable_init), @@ -351,6 +354,9 @@ static struct attribute *ext4_feat_attrs[] = { ATTR_LIST(fast_commit), #if IS_ENABLED(CONFIG_UNICODE) && defined(CONFIG_FS_ENCRYPTION) ATTR_LIST(encrypted_casefold), +#endif +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + ATTR_LIST(blocksize_gt_pagesize), #endif NULL, };