ext4: enable block size larger than page size

Since block device (See commit 3c20917120 ("block/bdev: enable large
folio support for large logical block sizes")) and page cache (See commit
ab95d23bab ("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 7ac67301e8 ("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 <tytso@mit.edu>
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: <20251121090654.631996-25-libaokun@huaweicloud.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This commit is contained in:
Baokun Li 2025-11-21 17:06:54 +08:00 committed by Theodore Ts'o
parent 709f0f1f1b
commit cab8cbcb92
2 changed files with 8 additions and 1 deletions

View File

@ -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");

View File

@ -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,
};