Re: [RFC v2 14/14] xfs: enable block size larger than page size support

Darrick J. Wong
2024-02-13T16:20:08Z

On Tue, Feb 13, 2024 at 10:37:13AM +0100, Pankaj Raghav (Samsung) wrote:
> From: Pankaj Raghav <p.raghav@samsung.com>
>
> Page cache now has the ability to have a minimum order when allocating
> a folio which is a prerequisite to add support for block size > page
> size. Enable it in XFS under CONFIG_XFS_LBS.
>
> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
> Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
> ---
> fs/xfs/xfs_icache.c | 8 ++++++--
> fs/xfs/xfs_super.c | 8 +++-----
> 2 files changed, 9 insertions(+), 7 deletions(-)
>
> diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
> index dba514a2c84d..9de81caf7ad4 100644
> --- a/fs/xfs/xfs_icache.c
> +++ b/fs/xfs/xfs_icache.c
> @@ -73,6 +73,7 @@ xfs_inode_alloc(
> xfs_ino_t ino)
> {
> struct xfs_inode *ip;
> + int min_order = 0;
>
> /*
> * XXX: If this didn't occur in transactions, we could drop GFP_NOFAIL
> @@ -88,7 +89,8 @@ xfs_inode_alloc(
> /* VFS doesn't initialise i_mode or i_state! */
> VFS_I(ip)->i_mode = 0;
> VFS_I(ip)->i_state = 0;
> - mapping_set_large_folios(VFS_I(ip)->i_mapping);
> + min_order = max(min_order, ilog2(mp->m_sb.sb_blocksize) - PAGE_SHIFT);
> + mapping_set_folio_orders(VFS_I(ip)->i_mapping, min_order, MAX_PAGECACHE_ORDER);
>
> XFS_STATS_INC(mp, vn_active);
> ASSERT(atomic_read(&ip->i_pincount) == 0);
> @@ -313,6 +315,7 @@ xfs_reinit_inode(
> dev_t dev = inode->i_rdev;
> kuid_t uid = inode->i_uid;
> kgid_t gid = inode->i_gid;
> + int min_order = 0;
>
> error = inode_init_always(mp->m_super, inode);
>
> @@ -323,7 +326,8 @@ xfs_reinit_inode(
> inode->i_rdev = dev;
> inode->i_uid = uid;
> inode->i_gid = gid;
> - mapping_set_large_folios(inode->i_mapping);
> + min_order = max(min_order, ilog2(mp->m_sb.sb_blocksize) - PAGE_SHIFT);
> + mapping_set_folio_orders(inode->i_mapping, min_order, MAX_PAGECACHE_ORDER);

Twice now I've seen this, which makes me think "refactor this into a
single function."

But then, this is really just:

mapping_set_folio_orders(inode->i_mapping,
max(0, inode->i_sb->s_blocksize_bits - PAGE_SHIFT),
MAX_PAGECACHE_ORDER);

Can we make that a generic inode_set_pagecache_orders helper?

> return error;
> }
>
> diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
> index 5a2512d20bd0..6a3f0f6727eb 100644
> --- a/fs/xfs/xfs_super.c
> +++ b/fs/xfs/xfs_super.c
> @@ -1625,13 +1625,11 @@ xfs_fs_fill_super(
> goto out_free_sb;
> }
>
> - /*
> - * Until this is fixed only page-sized or smaller data blocks work.
> - */
> - if (mp->m_sb.sb_blocksize > PAGE_SIZE) {
> + if (!IS_ENABLED(CONFIG_XFS_LBS) && mp->m_sb.sb_blocksize > PAGE_SIZE) {
> xfs_warn(mp,
> "File system with blocksize %d bytes. "
> - "Only pagesize (%ld) or less will currently work.",
> + "Only pagesize (%ld) or less will currently work. "
> + "Enable Experimental CONFIG_XFS_LBS for this support",
> mp->m_sb.sb_blocksize, PAGE_SIZE);

Please log a warning about the EXPERIMENTAL bs>ps feature being used
on this mount for the CONFIG_XFS_LBS=y case.

--D

> error = -ENOSYS;
> goto out_free_sb;
> --
> 2.43.0
>
>