Re: [PATCH 11/13] smb: introduce struct create_posix_ctxt_rsp

ChenXiaoSong
2025-12-10T00:13:09Z

Hi Namjae,

The `create_posix_rsp` structures on the client and server sides differ,
but they share a common part, and only this common part is defined in
POSIX‑SMB2 2.2.14.2.16.

/*
* [POSIX-SMB2] SMB3 POSIX Extensions
* Link:
https://gitlab.com/samba-team/smb3-posix-spec/-/blob/master/smb3_posix_extensions.md
*/

Thanks,
ChenXiaoSong.

On 12/10/25 7:45 AM, Namjae Jeon wrote:
> On Tue, Dec 9, 2025 at 10:12 AM <chenxiaosong.chenxiaosong@linux.dev> wrote:
>>
>> From: ZhangGuoDong <zhangguodong@kylinos.cn>
>>
>> Modify the following places:
>>
>> - introduce new struct create_posix_ctxt_rsp
>> - some fields in "struct create_posix_rsp" -> "struct create_posix_ctxt_rsp"
>> - create_posix_rsp_buf(): offsetof(..., nlink) -> offsetof(..., ctxt_rsp)
> I don't know why we need to add a new create_posix_ctxt_rsp struct.
>>
>> Co-developed-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
>> Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
>> Signed-off-by: ZhangGuoDong <zhangguodong@kylinos.cn>
>> ---
>> fs/smb/client/smb2pdu.c | 9 +++++----
>> fs/smb/client/smb2pdu.h | 6 ++----
>> fs/smb/common/smb2pdu.h | 18 ++++++++++++++++++
>> fs/smb/server/oplock.c | 8 ++++----
>> fs/smb/server/smb2pdu.h | 6 ++----
>> 5 files changed, 31 insertions(+), 16 deletions(-)
>>
>> diff --git a/fs/smb/client/smb2pdu.c b/fs/smb/client/smb2pdu.c
>> index ef2c6ac500f7..ec0f83db5591 100644
>> --- a/fs/smb/client/smb2pdu.c
>> +++ b/fs/smb/client/smb2pdu.c
>> @@ -2298,9 +2298,9 @@ parse_posix_ctxt(struct create_context *cc, struct smb2_file_all_info *info,
>>
>> memset(posix, 0, sizeof(*posix));
>>
>> - posix->nlink = le32_to_cpu(*(__le32 *)(beg + 0));
>> - posix->reparse_tag = le32_to_cpu(*(__le32 *)(beg + 4));
>> - posix->mode = le32_to_cpu(*(__le32 *)(beg + 8));
>> + posix->ctxt_rsp.nlink = le32_to_cpu(*(__le32 *)(beg + 0));
>> + posix->ctxt_rsp.reparse_tag = le32_to_cpu(*(__le32 *)(beg + 4));
>> + posix->ctxt_rsp.mode = le32_to_cpu(*(__le32 *)(beg + 8));
>>
>> sid = beg + 12;
>> sid_len = posix_info_sid_size(sid, end);
>> @@ -2319,7 +2319,8 @@ parse_posix_ctxt(struct create_context *cc, struct smb2_file_all_info *info,
>> memcpy(&posix->group, sid, sid_len);
>>
>> cifs_dbg(FYI, "nlink=%d mode=%o reparse_tag=%x\n",
>> - posix->nlink, posix->mode, posix->reparse_tag);
>> + posix->ctxt_rsp.nlink, posix->ctxt_rsp.mode,
>> + posix->ctxt_rsp.reparse_tag);
>> }
>>
>> int smb2_parse_contexts(struct TCP_Server_Info *server,
>> diff --git a/fs/smb/client/smb2pdu.h b/fs/smb/client/smb2pdu.h
>> index 78bb99f29d38..4928fb620233 100644
>> --- a/fs/smb/client/smb2pdu.h
>> +++ b/fs/smb/client/smb2pdu.h
>> @@ -251,11 +251,9 @@ struct smb2_file_id_extd_directory_info {
>>
>> extern char smb2_padding[7];
>>
>> -/* equivalent of the contents of SMB3.1.1 POSIX open context response */
>> +/* See POSIX-SMB2 2.2.14.2.16 */
>> struct create_posix_rsp {
>> - u32 nlink;
>> - u32 reparse_tag;
>> - u32 mode;
>> + struct create_posix_ctxt_rsp ctxt_rsp;
>> struct smb_sid owner; /* var-sized on the wire */
>> struct smb_sid group; /* var-sized on the wire */
>> } __packed;
>> diff --git a/fs/smb/common/smb2pdu.h b/fs/smb/common/smb2pdu.h
>> index 72f2cfc47da8..698ab9d7d16b 100644
>> --- a/fs/smb/common/smb2pdu.h
>> +++ b/fs/smb/common/smb2pdu.h
>> @@ -1814,4 +1814,22 @@ typedef struct smb_negotiate_req {
>> unsigned char DialectsArray[];
>> } __packed SMB_NEGOTIATE_REQ;
>>
>> +
>> +/*
>> + * [POSIX-SMB2] SMB3 POSIX Extensions
>> + * Link: https://gitlab.com/samba-team/smb3-posix-spec/-/blob/master/smb3_posix_extensions.md
>> + */
>> +
>> +/*
>> + * SMB2_CREATE_POSIX_CONTEXT Response
>> + * See POSIX-SMB2 2.2.14.2.16
>> + */
>> +struct create_posix_ctxt_rsp {
>> + __le32 nlink;
>> + __le32 reparse_tag;
>> + __le32 mode;
>> + // var sized owner SID
>> + // var sized group SID
>> +} __packed;
>> +
>> #endif /* _COMMON_SMB2PDU_H */
>> diff --git a/fs/smb/server/oplock.c b/fs/smb/server/oplock.c
>> index 1f07ebf431d7..8658402ff893 100644
>> --- a/fs/smb/server/oplock.c
>> +++ b/fs/smb/server/oplock.c
>> @@ -1703,7 +1703,7 @@ void create_posix_rsp_buf(char *cc, struct ksmbd_file *fp)
>> buf = (struct create_posix_rsp *)cc;
>> memset(buf, 0, sizeof(struct create_posix_rsp));
>> buf->ccontext.DataOffset = cpu_to_le16(offsetof
>> - (struct create_posix_rsp, nlink));
>> + (struct create_posix_rsp, ctxt_rsp));
>> /*
>> * DataLength = nlink(4) + reparse_tag(4) + mode(4) +
>> * domain sid(28) + unix group sid(16).
>> @@ -1730,9 +1730,9 @@ void create_posix_rsp_buf(char *cc, struct ksmbd_file *fp)
>> buf->Name[14] = 0xCD;
>> buf->Name[15] = 0x7C;
>>
>> - buf->nlink = cpu_to_le32(inode->i_nlink);
>> - buf->reparse_tag = cpu_to_le32(fp->volatile_id);
>> - buf->mode = cpu_to_le32(inode->i_mode & 0777);
>> + buf->ctxt_rsp.nlink = cpu_to_le32(inode->i_nlink);
>> + buf->ctxt_rsp.reparse_tag = cpu_to_le32(fp->volatile_id);
>> + buf->ctxt_rsp.mode = cpu_to_le32(inode->i_mode & 0777);
>> /*
>> * SidBuffer(44) contain two sids(Domain sid(28), UNIX group sid(16)).
>> * Domain sid(28) = revision(1) + num_subauth(1) + authority(6) +
>> diff --git a/fs/smb/server/smb2pdu.h b/fs/smb/server/smb2pdu.h
>> index 66cdc8e4a648..09311a9eb1de 100644
>> --- a/fs/smb/server/smb2pdu.h
>> +++ b/fs/smb/server/smb2pdu.h
>> @@ -83,13 +83,11 @@ struct create_durable_rsp {
>> } Data;
>> } __packed;
>>
>> -/* equivalent of the contents of SMB3.1.1 POSIX open context response */
>> +/* See POSIX-SMB2 2.2.14.2.16 */
>> struct create_posix_rsp {
>> struct create_context_hdr ccontext;
>> __u8 Name[16];
>> - __le32 nlink;
>> - __le32 reparse_tag;
>> - __le32 mode;
>> + struct create_posix_ctxt_rsp ctxt_rsp;
>> /* SidBuffer contain two sids(Domain sid(28), UNIX group sid(16)) */
>> u8 SidBuffer[44];
>> } __packed;
>> --
>> 2.43.0
>>