From: ChenXiaoSong <chenxiaosong@kylinos.cn>
Date: Mon, 8 Jun 2026 14:01:25 +0000 (+0000)
Subject: smb/server: implement FSCTL_GET_COMPRESSION ioctl handler
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c91f4543ddecc49c96c175a90f51c991957f72e3;p=thirdparty%2Fkernel%2Flinux.git

smb/server: implement FSCTL_GET_COMPRESSION ioctl handler

Example:

  1. server: chattr +c /export/file
  2. client: smbinfo getcompression /mnt/file
             Compression: 2 (LZNT1)

Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
---

diff --git a/fs/smb/common/smbfsctl.h b/fs/smb/common/smbfsctl.h
index 74e78bcb4618d..9debdd709d1c1 100644
--- a/fs/smb/common/smbfsctl.h
+++ b/fs/smb/common/smbfsctl.h
@@ -61,7 +61,7 @@
 #define FSCTL_LOCK_VOLUME            0x00090018
 #define FSCTL_UNLOCK_VOLUME          0x0009001C
 #define FSCTL_IS_PATHNAME_VALID      0x0009002C /* BB add struct */
-#define FSCTL_GET_COMPRESSION        0x0009003C /* BB add struct */
+#define FSCTL_GET_COMPRESSION        0x0009003C
 #define FSCTL_SET_COMPRESSION        0x0009C040 /* BB add struct */
 #define FSCTL_QUERY_FAT_BPB          0x00090058 /* BB add struct */
 /* Verify the next FSCTL number, we had it as 0x00090090 before */
diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c
index 4b8e1a4f9e6bf..975ca2ed84df6 100644
--- a/fs/smb/server/smb2pdu.c
+++ b/fs/smb/server/smb2pdu.c
@@ -8354,6 +8354,34 @@ int smb2_ioctl(struct ksmbd_work *work)
 		ret = -EOPNOTSUPP;
 		rsp->hdr.Status = STATUS_FS_DRIVER_REQUIRED;
 		goto out2;
+	case FSCTL_GET_COMPRESSION: {
+		struct compress_ioctl *cmpr_rsp;
+		struct ksmbd_file *fp;
+		u16 fmt;
+
+		if (out_buf_len < sizeof(struct compress_ioctl)) {
+			ret = -EINVAL;
+			goto out;
+		}
+
+		fp = ksmbd_lookup_fd_fast(work, id);
+		if (!fp) {
+			ret = -ENOENT;
+			goto out;
+		}
+
+		ret = ksmbd_vfs_get_compression(fp, &fmt);
+		ksmbd_fd_put(work, fp);
+		if (ret < 0)
+			goto out;
+
+		cmpr_rsp = (struct compress_ioctl *)&rsp->Buffer[0];
+		cmpr_rsp->CompressionState = cpu_to_le16(fmt);
+		nbytes = sizeof(struct compress_ioctl);
+		rsp->PersistentFileId = req->PersistentFileId;
+		rsp->VolatileFileId = req->VolatileFileId;
+		break;
+	}
 	case FSCTL_CREATE_OR_GET_OBJECT_ID:
 	{
 		struct file_object_buf_type1_ioctl_rsp *obj_buf;
diff --git a/fs/smb/server/vfs.c b/fs/smb/server/vfs.c
index b2403db135584..82cfd0b2a4cb7 100644
--- a/fs/smb/server/vfs.c
+++ b/fs/smb/server/vfs.c
@@ -1899,3 +1899,26 @@ void ksmbd_vfs_update_compressed_fattr(struct dentry *dentry, __le32 *fattr)
 	else
 		*fattr &= ~FILE_ATTRIBUTE_COMPRESSED_LE;
 }
+
+int ksmbd_vfs_get_compression(struct ksmbd_file *fp, u16 *fmt)
+{
+	struct file_kattr fa = { .flags_valid = true };
+	int rc;
+
+	rc = vfs_fileattr_get(fp->filp->f_path.dentry, &fa);
+	if (rc == -ENOIOCTLCMD) {
+		*fmt = COMPRESSION_FORMAT_NONE;
+		rc = 0;
+		goto out;
+	}
+	if (rc)
+		goto out;
+
+	if (fa.flags & FS_COMPR_FL)
+		*fmt = COMPRESSION_FORMAT_LZNT1;
+	else
+		*fmt = COMPRESSION_FORMAT_NONE;
+
+out:
+	return rc;
+}
diff --git a/fs/smb/server/vfs.h b/fs/smb/server/vfs.h
index ac6dda173b752..f6121207dbda4 100644
--- a/fs/smb/server/vfs.h
+++ b/fs/smb/server/vfs.h
@@ -169,4 +169,5 @@ int ksmbd_vfs_inherit_posix_acl(struct mnt_idmap *idmap,
 				const struct path *path,
 				struct inode *parent_inode);
 void ksmbd_vfs_update_compressed_fattr(struct dentry *dentry, __le32 *fattr);
+int ksmbd_vfs_get_compression(struct ksmbd_file *fp, u16 *fmt);
 #endif /* __KSMBD_VFS_H__ */