Re: [f2fs-dev] [PATCH v2] f2fs: support zero sized file truncate for device aliasing files

[Chao Yu <chao@kernel.org>]

On 3/22/25 05:33, Daeho Jeong wrote:
> From: Daeho Jeong <daehojeong@google.com>
> 
> support a file truncation to zero size for device aliasing files.
> 
> Signed-off-by: Daeho Jeong <daehojeong@google.com>
> ---
> v2: make the extent length zero
> ---
>  fs/f2fs/file.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
> index f92a9fba9991..69952f208086 100644
> --- a/fs/f2fs/file.c
> +++ b/fs/f2fs/file.c
> @@ -775,6 +775,11 @@ int f2fs_do_truncate_blocks(struct inode *inode, u64 from, bool lock)
>  		f2fs_update_time(sbi, REQ_TIME);
>  
>  		f2fs_put_page(ipage, 1);
> +
> +		write_lock(&et->lock);
> +		et->largest.len = 0;
> +		write_unlock(&et->lock);

f2fs_mark_inode_dirty_sync(inode, true); ?

Thanks,

> +
>  		goto out;
>  	}
>  
> @@ -1036,7 +1041,7 @@ int f2fs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
>  
>  	if ((attr->ia_valid & ATTR_SIZE)) {
>  		if (!f2fs_is_compress_backend_ready(inode) ||
> -				IS_DEVICE_ALIASING(inode))
> +				(IS_DEVICE_ALIASING(inode) && attr->ia_size))
>  			return -EOPNOTSUPP;
>  		if (is_inode_flag_set(inode, FI_COMPRESS_RELEASED) &&
>  			!IS_ALIGNED(attr->ia_size,