Allow setting per-file compression via CIFS protocol

An earlier patch allowed setting the per-file compression flag

"chattr +c filename"

on an smb2 or smb3 mount, and also allowed lsattr to return
whether a file on a cifs, or smb2/smb3 mount was compressed.

This patch extends the ability to set the per-file
compression flag to the cifs protocol, which uses a somewhat
different IOCTL mechanism than SMB2, although the payload
(the flags stored in the compression_state) are the same.

Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>

fs/cifs/cifspdu.h

@@ -1352,6 +1352,35 @@ typedef struct smb_com_transaction_ioctl_req {
 	__u8 Data[1];
 } __attribute__((packed)) TRANSACT_IOCTL_REQ;
 
+typedef struct smb_com_transaction_compr_ioctl_req {
+	struct smb_hdr hdr;	/* wct = 23 */
+	__u8 MaxSetupCount;
+	__u16 Reserved;
+	__le32 TotalParameterCount;
+	__le32 TotalDataCount;
+	__le32 MaxParameterCount;
+	__le32 MaxDataCount;
+	__le32 ParameterCount;
+	__le32 ParameterOffset;
+	__le32 DataCount;
+	__le32 DataOffset;
+	__u8 SetupCount; /* four setup words follow subcommand */
+	/* SNIA spec incorrectly included spurious pad here */
+	__le16 SubCommand; /* 2 = IOCTL/FSCTL */
+	__le32 FunctionCode;
+	__u16 Fid;
+	__u8 IsFsctl;  /* 1 = File System Control 0 = device control (IOCTL) */
+	__u8 IsRootFlag; /* 1 = apply command to root of share (must be DFS) */
+	__le16 ByteCount;
+	__u8 Pad[3];
+	__le16 compression_state;  /* See below for valid flags */
+} __attribute__((packed)) TRANSACT_COMPR_IOCTL_REQ;
+
+/* compression state flags */
+#define COMPRESSION_FORMAT_NONE		0x0000
+#define COMPRESSION_FORMAT_DEFAULT	0x0001
+#define COMPRESSION_FORMAT_LZNT1	0x0002
+
 typedef struct smb_com_transaction_ioctl_rsp {
 	struct smb_hdr hdr;	/* wct = 19 */
 	__u8 Reserved[3];

fs/cifs/cifsproto.h

@@ -360,6 +360,8 @@ extern int CIFSSMBUnixQuerySymLink(const unsigned int xid,
 extern int CIFSSMBQuerySymLink(const unsigned int xid, struct cifs_tcon *tcon,
 			       __u16 fid, char **symlinkinfo,
 			       const struct nls_table *nls_codepage);
+extern int CIFSSMB_set_compression(const unsigned int xid,
+				   struct cifs_tcon *tcon, __u16 fid);
 extern int CIFSSMBOpen(const unsigned int xid, struct cifs_tcon *tcon,
 			const char *fileName, const int disposition,
 			const int access_flags, const int omode,

fs/cifs/cifssmb.c

@@ -3199,6 +3199,60 @@ CIFSSMBQuerySymLink(const unsigned int xid, struct cifs_tcon *tcon,
 	return rc;
 }
 
+int
+CIFSSMB_set_compression(const unsigned int xid, struct cifs_tcon *tcon,
+		    __u16 fid)
+{
+	int rc = 0;
+	int bytes_returned;
+	struct smb_com_transaction_compr_ioctl_req *pSMB;
+	struct smb_com_transaction_ioctl_rsp *pSMBr;
+
+	cifs_dbg(FYI, "Set compression for %u\n", fid);
+	rc = smb_init(SMB_COM_NT_TRANSACT, 23, tcon, (void **) &pSMB,
+		      (void **) &pSMBr);
+	if (rc)
+		return rc;
+
+	pSMB->compression_state = cpu_to_le16(COMPRESSION_FORMAT_DEFAULT);
+
+	pSMB->TotalParameterCount = 0;
+	pSMB->TotalDataCount = __constant_cpu_to_le32(2);
+	pSMB->MaxParameterCount = 0;
+	pSMB->MaxDataCount = 0;
+	pSMB->MaxSetupCount = 4;
+	pSMB->Reserved = 0;
+	pSMB->ParameterOffset = 0;
+	pSMB->DataCount = __constant_cpu_to_le32(2);
+	pSMB->DataOffset =
+		cpu_to_le32(offsetof(struct smb_com_transaction_compr_ioctl_req,
+				compression_state) - 4);  /* 84 */
+	pSMB->SetupCount = 4;
+	pSMB->SubCommand = __constant_cpu_to_le16(NT_TRANSACT_IOCTL);
+	pSMB->ParameterCount = 0;
+	pSMB->FunctionCode = __constant_cpu_to_le32(FSCTL_SET_COMPRESSION);
+	pSMB->IsFsctl = 1; /* FSCTL */
+	pSMB->IsRootFlag = 0;
+	pSMB->Fid = fid; /* file handle always le */
+	/* 3 byte pad, followed by 2 byte compress state */
+	pSMB->ByteCount = __constant_cpu_to_le16(5);
+	inc_rfc1001_len(pSMB, 5);
+
+	rc = SendReceive(xid, tcon->ses, (struct smb_hdr *) pSMB,
+			 (struct smb_hdr *) pSMBr, &bytes_returned, 0);
+	if (rc)
+		cifs_dbg(FYI, "Send error in SetCompression = %d\n", rc);
+
+	cifs_buf_release(pSMB);
+
+	/*
+	 * Note: On -EAGAIN error only caller can retry on handle based calls
+	 * since file handle passed in no longer valid.
+	 */
+	return rc;
+}
+
+
 #ifdef CONFIG_CIFS_POSIX
 
 /*Convert an Access Control Entry from wire format to local POSIX xattr format*/

fs/cifs/smb1ops.c

@@ -806,6 +806,13 @@ smb_set_file_info(struct inode *inode, const char *full_path,
 	return rc;
 }
 
+static int
+cifs_set_compression(const unsigned int xid, struct cifs_tcon *tcon,
+		   struct cifsFileInfo *cfile)
+{
+	return CIFSSMB_set_compression(xid, tcon, cfile->fid.netfid);
+}
+
 static int
 cifs_query_dir_first(const unsigned int xid, struct cifs_tcon *tcon,
 		     const char *path, struct cifs_sb_info *cifs_sb,
@@ -956,6 +963,7 @@ struct smb_version_operations smb1_operations = {
 	.set_path_size = CIFSSMBSetEOF,
 	.set_file_size = CIFSSMBSetFileSize,
 	.set_file_info = smb_set_file_info,
+	.set_compression = cifs_set_compression,
 	.echo = CIFSSMBEcho,
 	.mkdir = CIFSSMBMkDir,
 	.mkdir_setinfo = cifs_mkdir_setinfo,

fs/cifs/smb2pdu.h

@@ -570,12 +570,9 @@ struct network_interface_info_ioctl_rsp {
 #define NO_FILE_ID 0xFFFFFFFFFFFFFFFFULL /* general ioctls to srv not to file */
 
 struct compress_ioctl {
-	__le16 CompressionState;
+	__le16 CompressionState; /* See cifspdu.h for possible flag values */
 } __packed;
 
-#define COMPRESSION_FORMAT_NONE		0x0000
-#define COMPRESSION_FORMAT_DEFAULT	0x0001
-#define COMPRESSION_FORMAT_LZNT1	0x0002
 struct smb2_ioctl_req {
 	struct smb2_hdr hdr;
 	__le16 StructureSize;	/* Must be 57 */