Re: [PATCH 02/12] fs/ceph/super: make field `i_truncate_pagecache_size` optional

[Viacheslav Dubeyko]

On Fri, 2026-06-12 at 18:51 +0200, Max Kellermann wrote:
> This field is only used with CONFIG_FS_ENCRYPTION; without it, it
> always equals `i_truncate_size`.
> 
> This reduces the size of `struct ceph_inode_info` by 8 bytes on
> kernels that have filesystem encryption disabled.
> 
> Signed-off-by: Max Kellermann <max.kellermann@xxxxxxxxx>
> ---
>  fs/ceph/inode.c |  8 ++++++--
>  fs/ceph/super.h | 11 +++++++++++
>  2 files changed, 17 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
> index 22c7da1ea61c..1504b889622c 100644
> --- a/fs/ceph/inode.c
> +++ b/fs/ceph/inode.c
> @@ -680,7 +680,9 @@ struct inode *ceph_alloc_inode(struct super_block
> *sb)
>  	ci->i_truncate_seq = 0;
>  	ci->i_truncate_size = 0;
>  	ci->i_truncate_pending = 0;
> +#ifdef CONFIG_FS_ENCRYPTION
>  	ci->i_truncate_pagecache_size = 0;
> +#endif
>  
>  	ci->i_max_size = 0;
>  	ci->i_reported_size = 0;
> @@ -865,6 +867,7 @@ int ceph_fill_file_size(struct inode *inode, int
> issued,
>  
>  		ci->i_truncate_size = truncate_size;
>  
> +#ifdef CONFIG_FS_ENCRYPTION
>  		if (IS_ENCRYPTED(inode)) {
>  			doutc(cl, "truncate_pagecache_size %lld ->
> %llu\n",
>  			      ci->i_truncate_pagecache_size, size);
> @@ -872,6 +875,7 @@ int ceph_fill_file_size(struct inode *inode, int
> issued,
>  		} else {
>  			ci->i_truncate_pagecache_size =
> truncate_size;
>  		}
> +#endif
>  	}
>  	return queue_trunc;
>  }
> @@ -2331,7 +2335,7 @@ void __ceph_do_pending_vmtruncate(struct inode
> *inode)
>  	/* there should be no reader or writer */
>  	WARN_ON_ONCE(ci->i_rd_ref || ci->i_wr_ref);
>  
> -	to = ci->i_truncate_pagecache_size;
> +	to = ceph_get_truncate_pagecache_size(ci);
>  	wrbuffer_refs = ci->i_wrbuffer_ref;
>  	doutc(cl, "%p %llx.%llx (%d) to %lld\n", inode,
> ceph_vinop(inode),
>  	      ci->i_truncate_pending, to);
> @@ -2341,7 +2345,7 @@ void __ceph_do_pending_vmtruncate(struct inode
> *inode)
>  	truncate_pagecache(inode, to);
>  
>  	spin_lock(&ci->i_ceph_lock);
> -	if (to == ci->i_truncate_pagecache_size) {
> +	if (to == ceph_get_truncate_pagecache_size(ci)) {
>  		ci->i_truncate_pending = 0;
>  		finish = 1;
>  	}
> diff --git a/fs/ceph/super.h b/fs/ceph/super.h
> index 6aec40955387..f0f03aeb5b19 100644
> --- a/fs/ceph/super.h
> +++ b/fs/ceph/super.h
> @@ -461,11 +461,14 @@ struct ceph_inode_info {
>  	u32 i_truncate_seq;        /* last truncate to smaller size
> */
>  	u64 i_truncate_size;       /*  and the size we last
> truncated down to */
>  	int i_truncate_pending;    /*  still need to call vmtruncate
> */
> +
> +#ifdef CONFIG_FS_ENCRYPTION
>  	/*
>  	 * For none fscrypt case it equals to i_truncate_size or it
> will
>  	 * equals to fscrypt_file_size
>  	 */
>  	u64 i_truncate_pagecache_size;
> +#endif
>  
>  	u64 i_max_size;            /* max file size authorized by
> mds */
>  	u64 i_reported_size; /* (max_)size reported to or requested
> of mds */
> @@ -660,6 +663,14 @@ static inline struct inode
> *ceph_find_inode(struct super_block *sb,
>  	return ilookup5(sb, (unsigned long)vino.ino,
> ceph_ino_compare, &vino);
>  }
>  
> +static inline u64 ceph_get_truncate_pagecache_size(const struct
> ceph_inode_info *ci)
> +{
> +#ifdef CONFIG_CEPH_FS_SNAPSHOTS

Maybe, I am missing something. But where CONFIG_CEPH_FS_SNAPSHOTS is
defined? Currently, we don't have it in the fs/ceph/Kconfig and the
patch has no declaration of this compilation option.

Thanks,
Slava.

> +	return ci->i_truncate_pagecache_size;
> +#else
> +	return ci->i_truncate_size;
> +#endif
> +}
>  
>  /*
>   * Ceph inode.