[v5] smb: move duplicate definitions to common header file

[PATCH v5 12/14] smb: move FILE_SYSTEM_ATTRIBUTE_INFO to common/fscc.h

Posted by chenxiaosong.chenxiaosong@linux.dev 3 months, 1 week ago

From: ChenXiaoSong <chenxiaosong@kylinos.cn>

Rename "struct filesystem_attribute_info" to "FILE_SYSTEM_ATTRIBUTE_INFO",
then move them to common header file.

Calculate the minimum size of FileFsAttributeInformation using offsetof().

On the server, replace original "sizeof(struct filesystem_attribute_info)"
with "MIN_FS_ATTR_INFO_SIZE".

Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
---
 fs/smb/client/cifspdu.h    | 10 ----------
 fs/smb/common/fscc.h       | 14 ++++++++++++++
 fs/smb/server/smb2pdu.c    |  6 +++---
 fs/smb/server/smb_common.h |  7 -------
 4 files changed, 17 insertions(+), 20 deletions(-)

diff --git a/fs/smb/client/cifspdu.h b/fs/smb/client/cifspdu.h
index a9a853b9011f..2c454e450dfa 100644
--- a/fs/smb/client/cifspdu.h
+++ b/fs/smb/client/cifspdu.h
@@ -2063,16 +2063,6 @@ typedef struct {
 #define FILE_PORTABLE_DEVICE			0x00004000
 #define FILE_DEVICE_ALLOW_APPCONTAINER_TRAVERSAL 0x00020000
 
-/* minimum includes first three fields, and empty FS Name */
-#define MIN_FS_ATTR_INFO_SIZE 12
-
-typedef struct {
-	__le32 Attributes;
-	__le32 MaxPathNameComponentLength;
-	__le32 FileSystemNameLen;
-	char FileSystemName[52]; /* do not have to save this - get subset? */
-} __attribute__((packed)) FILE_SYSTEM_ATTRIBUTE_INFO;
-
 /******************************************************************************/
 /* QueryFileInfo/QueryPathinfo (also for SetPath/SetFile) data buffer formats */
 /******************************************************************************/
diff --git a/fs/smb/common/fscc.h b/fs/smb/common/fscc.h
index a0580a772a41..9d3ac9903357 100644
--- a/fs/smb/common/fscc.h
+++ b/fs/smb/common/fscc.h
@@ -94,6 +94,20 @@ struct smb2_file_network_open_info {
 	__le32 Reserved;
 } __packed; /* level 34 Query also similar returned in close rsp and open rsp */
 
+/* See FS-FSCC 2.5.1 */
+typedef struct {
+	__le32 Attributes;
+	__le32 MaxPathNameComponentLength;
+	__le32 FileSystemNameLen;
+	__le16 FileSystemName[52]; /* do not have to save this - get subset? */
+} __packed FILE_SYSTEM_ATTRIBUTE_INFO;
+
+/*
+ * minimum size of FileFsAttributeInformation
+ * includes first three fields, and empty FS Name
+ */
+#define MIN_FS_ATTR_INFO_SIZE	offsetof(FILE_SYSTEM_ATTRIBUTE_INFO, FileSystemName)
+
 /* List of FileSystemAttributes - see MS-FSCC 2.5.1 */
 #define FILE_SUPPORTS_SPARSE_VDL	0x10000000 /* faster nonsparse extend */
 #define FILE_SUPPORTS_BLOCK_REFCOUNTING	0x08000000 /* allow ioctl dup extents */
diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c
index ae778ad99d30..221e979adcef 100644
--- a/fs/smb/server/smb2pdu.c
+++ b/fs/smb/server/smb2pdu.c
@@ -5492,10 +5492,10 @@ static int smb2_get_info_filesystem(struct ksmbd_work *work,
 	}
 	case FS_ATTRIBUTE_INFORMATION:
 	{
-		struct filesystem_attribute_info *info;
+		FILE_SYSTEM_ATTRIBUTE_INFO *info;
 		size_t sz;
 
-		info = (struct filesystem_attribute_info *)rsp->Buffer;
+		info = (FILE_SYSTEM_ATTRIBUTE_INFO *)rsp->Buffer;
 		info->Attributes = cpu_to_le32(FILE_SUPPORTS_OBJECT_IDS |
 					       FILE_PERSISTENT_ACLS |
 					       FILE_UNICODE_ON_DISK |
@@ -5514,7 +5514,7 @@ static int smb2_get_info_filesystem(struct ksmbd_work *work,
 					"NTFS", PATH_MAX, conn->local_nls, 0);
 		len = len * 2;
 		info->FileSystemNameLen = cpu_to_le32(len);
-		sz = sizeof(struct filesystem_attribute_info) + len;
+		sz = MIN_FS_ATTR_INFO_SIZE + len;
 		rsp->OutputBufferLength = cpu_to_le32(sz);
 		break;
 	}
diff --git a/fs/smb/server/smb_common.h b/fs/smb/server/smb_common.h
index e7298faa3c6a..afeba063cc27 100644
--- a/fs/smb/server/smb_common.h
+++ b/fs/smb/server/smb_common.h
@@ -97,13 +97,6 @@ struct smb_negotiate_rsp {
 	__le16 ByteCount;
 } __packed;
 
-struct filesystem_attribute_info {
-	__le32 Attributes;
-	__le32 MaxPathNameComponentLength;
-	__le32 FileSystemNameLen;
-	__le16 FileSystemName[]; /* do not have to save this - get subset? */
-} __packed;
-
 struct filesystem_vol_info {
 	__le64 VolumeCreationTime;
 	__le32 SerialNumber;
-- 
2.43.0

Re: [PATCH v5 12/14] smb: move FILE_SYSTEM_ATTRIBUTE_INFO to common/fscc.h

Posted by Namjae Jeon 2 months, 3 weeks ago

On Sun, Nov 2, 2025 at 4:32 PM <chenxiaosong.chenxiaosong@linux.dev> wrote:
>
> From: ChenXiaoSong <chenxiaosong@kylinos.cn>
>
> Rename "struct filesystem_attribute_info" to "FILE_SYSTEM_ATTRIBUTE_INFO",
> then move them to common header file.
>
> Calculate the minimum size of FileFsAttributeInformation using offsetof().
>
> On the server, replace original "sizeof(struct filesystem_attribute_info)"
> with "MIN_FS_ATTR_INFO_SIZE".
>
> Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
> ---
>  fs/smb/client/cifspdu.h    | 10 ----------
>  fs/smb/common/fscc.h       | 14 ++++++++++++++
>  fs/smb/server/smb2pdu.c    |  6 +++---
>  fs/smb/server/smb_common.h |  7 -------
>  4 files changed, 17 insertions(+), 20 deletions(-)
>
> diff --git a/fs/smb/client/cifspdu.h b/fs/smb/client/cifspdu.h
> index a9a853b9011f..2c454e450dfa 100644
> --- a/fs/smb/client/cifspdu.h
> +++ b/fs/smb/client/cifspdu.h
> @@ -2063,16 +2063,6 @@ typedef struct {
>  #define FILE_PORTABLE_DEVICE                   0x00004000
>  #define FILE_DEVICE_ALLOW_APPCONTAINER_TRAVERSAL 0x00020000
>
> -/* minimum includes first three fields, and empty FS Name */
> -#define MIN_FS_ATTR_INFO_SIZE 12
> -
> -typedef struct {
> -       __le32 Attributes;
> -       __le32 MaxPathNameComponentLength;
> -       __le32 FileSystemNameLen;
> -       char FileSystemName[52]; /* do not have to save this - get subset? */
> -} __attribute__((packed)) FILE_SYSTEM_ATTRIBUTE_INFO;
> -
>  /******************************************************************************/
>  /* QueryFileInfo/QueryPathinfo (also for SetPath/SetFile) data buffer formats */
>  /******************************************************************************/
> diff --git a/fs/smb/common/fscc.h b/fs/smb/common/fscc.h
> index a0580a772a41..9d3ac9903357 100644
> --- a/fs/smb/common/fscc.h
> +++ b/fs/smb/common/fscc.h
> @@ -94,6 +94,20 @@ struct smb2_file_network_open_info {
>         __le32 Reserved;
>  } __packed; /* level 34 Query also similar returned in close rsp and open rsp */
>
> +/* See FS-FSCC 2.5.1 */
> +typedef struct {
> +       __le32 Attributes;
> +       __le32 MaxPathNameComponentLength;
> +       __le32 FileSystemNameLen;
> +       __le16 FileSystemName[52]; /* do not have to save this - get subset? */
Is there any reason why we can not use flex-array ?
Thanks.

Re: [PATCH v5 12/14] smb: move FILE_SYSTEM_ATTRIBUTE_INFO to common/fscc.h

Posted by ChenXiaoSong 2 months, 3 weeks ago

In the client-side code, SMB2_QFS_attr() needs to get the maximum and 
minimum lengths of the FileFsAttributeInformation. Using a flexible 
array would require more extensive changes.

Thanks,
ChenXiaoSong.

On 11/13/25 9:23 AM, Namjae Jeon wrote:
> Is there any reason why we can not use flex-array ?
> Thanks.

Re: [PATCH v5 12/14] smb: move FILE_SYSTEM_ATTRIBUTE_INFO to common/fscc.h

Posted by ChenXiaoSong 2 months, 3 weeks ago

It seems that the client side does not use FileSystemName[52], so I will 
try modifying it to use a flexible array.

Thanks,
ChenXiaoSong.

On 11/13/25 9:56 AM, ChenXiaoSong wrote:
> In the client-side code, SMB2_QFS_attr() needs to get the maximum and 
> minimum lengths of the FileFsAttributeInformation. Using a flexible 
> array would require more extensive changes.
> 
> Thanks,
> ChenXiaoSong.
> 
> On 11/13/25 9:23 AM, Namjae Jeon wrote:
>> Is there any reason why we can not use flex-array ?
>> Thanks.
>