Re: [PATCH v2] ksmbd: remove unnecessary generic_fillattr in smb2_open

From: Namjae Jeon <linkinjeon@kernel.org>
To: Hyunchul Lee <hyc.lee@gmail.com>
Cc: linux-cifs <linux-cifs@vger.kernel.org>,
	Steve French <smfrench@gmail.com>,
	Sergey Senozhatsky <senozhatsky@chromium.org>
Subject: Re: [PATCH v2] ksmbd: remove unnecessary generic_fillattr in smb2_open
Date: Wed, 10 Aug 2022 16:58:09 +0900	[thread overview]
Message-ID: <CAKYAXd8vXKY2mp58zc3epFxS7Pp4AZ+ggKh0Rv-rXCLAaQAW1w@mail.gmail.com> (raw)
In-Reply-To: <20220810010446.9229-1-hyc.lee@gmail.com>

2022-08-10 10:04 GMT+09:00, Hyunchul Lee <hyc.lee@gmail.com>:
> Move the call of ksmbd_vfs_getattr above the place
> where stat is needed, and remove unnecessary
> the call of generic_fillattr.
>
> This patch fixes wrong AllocationSize of SMB2_CREATE
> response. Because ext4 updates inode->i_blocks only
> when disk space is allocated, generic_fillattr does
> not set stat.blocks properly for delayed allocation.
So what causes delay allocation between the lines you moved this code?

> But ext4 returns the blocks that include the delayed
> allocation blocks when getattr is called.
>
> Signed-off-by: Hyunchul Lee <hyc.lee@gmail.com>
> ---
> Changes from v1:
>  - Update the commit description.
>
>  fs/ksmbd/smb2pdu.c | 15 ++++++---------
>  1 file changed, 6 insertions(+), 9 deletions(-)
>
> diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c
> index e6f4ccc12f49..7b4bd0d81133 100644
> --- a/fs/ksmbd/smb2pdu.c
> +++ b/fs/ksmbd/smb2pdu.c
> @@ -3022,12 +3022,6 @@ int smb2_open(struct ksmbd_work *work)
>  	list_add(&fp->node, &fp->f_ci->m_fp_list);
>  	write_unlock(&fp->f_ci->m_lock);
>
> -	rc = ksmbd_vfs_getattr(&path, &stat);
> -	if (rc) {
> -		generic_fillattr(user_ns, d_inode(path.dentry), &stat);
> -		rc = 0;
> -	}
> -
>  	/* Check delete pending among previous fp before oplock break */
>  	if (ksmbd_inode_pending_delete(fp)) {
>  		rc = -EBUSY;
> @@ -3114,6 +3108,12 @@ int smb2_open(struct ksmbd_work *work)
>  		}
>  	}
>
> +	rc = ksmbd_vfs_getattr(&path, &stat);
> +	if (rc) {
> +		generic_fillattr(user_ns, d_inode(path.dentry), &stat);
> +		rc = 0;
> +	}
> +
>  	if (stat.result_mask & STATX_BTIME)
>  		fp->create_time = ksmbd_UnixTimeToNT(stat.btime);
>  	else
> @@ -3129,9 +3129,6 @@ int smb2_open(struct ksmbd_work *work)
>
>  	memcpy(fp->client_guid, conn->ClientGUID, SMB2_CLIENT_GUID_SIZE);
>
> -	generic_fillattr(user_ns, file_inode(fp->filp),
> -			 &stat);
> -
>  	rsp->StructureSize = cpu_to_le16(89);
>  	rcu_read_lock();
>  	opinfo = rcu_dereference(fp->f_opinfo);
> --
> 2.17.1
>
>