cifs: Add support for creating reparse points over SMB1

SMB1 already supports querying reparse points and detecting types of
symlink, fifo, socket, block and char.

This change implements the missing part - ability to create a new reparse
points over SMB1. This includes everything which SMB2+ already supports:
- native SMB symlinks and sockets
- NFS style of special files (symlinks, fifos, sockets, char/block devs)
- WSL style of special files (symlinks, fifos, sockets, char/block devs)

Attaching a reparse point to an existing file or directory is done via
SMB1 SMB_COM_NT_TRANSACT/NT_TRANSACT_IOCTL/FSCTL_SET_REPARSE_POINT command
and implemented in a new cifs_create_reparse_inode() function.

This change introduce a new callback ->create_reparse_inode() which creates
a new reperse point file or directory and returns inode. For SMB1 it is
provided via that new cifs_create_reparse_inode() function.

Existing reparse.c code was only slightly updated to call new protocol
callback ->create_reparse_inode() instead of hardcoded SMB2+ function.
This make the whole reparse.c code to work with every SMB dialect.

The original callback ->create_reparse_symlink() is not needed anymore as
the implementation of new create_reparse_symlink() function is dialect
agnostic too. So the link.c code was updated to call that function directly
(and not via callback).

Signed-off-by: Pali Rohár <[email protected]>
Signed-off-by: Steve French <[email protected]>

Author: pali

fs/smb/client/cifsglob.h

@@ -627,12 +627,14 @@ struct smb_version_operations {
 	bool (*is_network_name_deleted)(char *buf, struct TCP_Server_Info *srv);
 	struct reparse_data_buffer * (*get_reparse_point_buffer)(const struct kvec *rsp_iov,
 								 u32 *plen);
-	int (*create_reparse_symlink)(const unsigned int xid,
-				      struct inode *inode,
-				      struct dentry *dentry,
-				      struct cifs_tcon *tcon,
-				      const char *full_path,
-				      const char *symname);
+	struct inode * (*create_reparse_inode)(struct cifs_open_info_data *data,
+					       struct super_block *sb,
+					       const unsigned int xid,
+					       struct cifs_tcon *tcon,
+					       const char *full_path,
+					       bool directory,
+					       struct kvec *reparse_iov,
+					       struct kvec *xattr_iov);
 };
 
 struct smb_version_values {

fs/smb/client/cifsproto.h

@@ -483,6 +483,14 @@ extern int cifs_query_reparse_point(const unsigned int xid,
 				    const char *full_path,
 				    u32 *tag, struct kvec *rsp,
 				    int *rsp_buftype);
+extern struct inode *cifs_create_reparse_inode(struct cifs_open_info_data *data,
+					       struct super_block *sb,
+					       const unsigned int xid,
+					       struct cifs_tcon *tcon,
+					       const char *full_path,
+					       bool directory,
+					       struct kvec *reparse_iov,
+					       struct kvec *xattr_iov);
 extern int CIFSSMB_set_compression(const unsigned int xid,
 				   struct cifs_tcon *tcon, __u16 fid);
 extern int CIFS_open(const unsigned int xid, struct cifs_open_parms *oparms,

fs/smb/client/cifssmb.c

@@ -2851,6 +2851,134 @@ int cifs_query_reparse_point(const unsigned int xid,
 	return rc;
 }
 
+struct inode *cifs_create_reparse_inode(struct cifs_open_info_data *data,
+					struct super_block *sb,
+					const unsigned int xid,
+					struct cifs_tcon *tcon,
+					const char *full_path,
+					bool directory,
+					struct kvec *reparse_iov,
+					struct kvec *xattr_iov)
+{
+	struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
+	struct cifs_open_parms oparms;
+	TRANSACT_IOCTL_REQ *io_req;
+	struct inode *new = NULL;
+	struct kvec in_iov[2];
+	struct kvec out_iov;
+	struct cifs_fid fid;
+	int io_req_len;
+	int oplock = 0;
+	int buf_type = 0;
+	int rc;
+
+	cifs_tcon_dbg(FYI, "%s: path=%s\n", __func__, full_path);
+
+	/*
+	 * If server filesystem does not support reparse points then do not
+	 * attempt to create reparse point. This will prevent creating unusable
+	 * empty object on the server.
+	 */
+	if (!(le32_to_cpu(tcon->fsAttrInfo.Attributes) & FILE_SUPPORTS_REPARSE_POINTS))
+		return ERR_PTR(-EOPNOTSUPP);
+
+#ifndef CONFIG_CIFS_XATTR
+	if (xattr_iov)
+		return ERR_PTR(-EOPNOTSUPP);
+#endif
+
+	oparms = CIFS_OPARMS(cifs_sb, tcon, full_path,
+			     FILE_READ_ATTRIBUTES | FILE_WRITE_DATA | FILE_WRITE_EA,
+			     FILE_CREATE,
+			     (directory ? CREATE_NOT_FILE : CREATE_NOT_DIR) | OPEN_REPARSE_POINT,
+			     ACL_NO_MODE);
+	oparms.fid = &fid;
+
+	rc = CIFS_open(xid, &oparms, &oplock, NULL);
+	if (rc)
+		return ERR_PTR(rc);
+
+#ifdef CONFIG_CIFS_XATTR
+	if (xattr_iov) {
+		struct smb2_file_full_ea_info *ea;
+
+		ea = &((struct smb2_create_ea_ctx *)xattr_iov->iov_base)->ea;
+		while (1) {
+			rc = CIFSSMBSetEA(xid,
+					  tcon,
+					  full_path,
+					  &ea->ea_data[0],
+					  &ea->ea_data[ea->ea_name_length+1],
+					  le16_to_cpu(ea->ea_value_length),
+					  cifs_sb->local_nls,
+					  cifs_sb);
+			if (rc)
+				goto out_close;
+			if (le32_to_cpu(ea->next_entry_offset) == 0)
+				break;
+			ea = (struct smb2_file_full_ea_info *)((u8 *)ea +
+				le32_to_cpu(ea->next_entry_offset));
+		}
+	}
+#endif
+
+	rc = smb_init(SMB_COM_NT_TRANSACT, 23, tcon, (void **)&io_req, NULL);
+	if (rc)
+		goto out_close;
+
+	inc_rfc1001_len(io_req, sizeof(io_req->Pad));
+
+	io_req_len = be32_to_cpu(io_req->hdr.smb_buf_length) + sizeof(io_req->hdr.smb_buf_length);
+
+	/* NT IOCTL response contains one-word long output setup buffer with size of output data. */
+	io_req->MaxSetupCount = 1;
+	/* NT IOCTL response does not contain output parameters. */
+	io_req->MaxParameterCount = cpu_to_le32(0);
+	/* FSCTL_SET_REPARSE_POINT response contains empty output data. */
+	io_req->MaxDataCount = cpu_to_le32(0);
+
+	io_req->TotalParameterCount = cpu_to_le32(0);
+	io_req->TotalDataCount = cpu_to_le32(reparse_iov->iov_len);
+	io_req->ParameterCount = io_req->TotalParameterCount;
+	io_req->ParameterOffset = cpu_to_le32(0);
+	io_req->DataCount = io_req->TotalDataCount;
+	io_req->DataOffset = cpu_to_le32(offsetof(typeof(*io_req), Data) -
+					 sizeof(io_req->hdr.smb_buf_length));
+	io_req->SetupCount = 4;
+	io_req->SubCommand = cpu_to_le16(NT_TRANSACT_IOCTL);
+	io_req->FunctionCode = cpu_to_le32(FSCTL_SET_REPARSE_POINT);
+	io_req->Fid = fid.netfid;
+	io_req->IsFsctl = 1;
+	io_req->IsRootFlag = 0;
+	io_req->ByteCount = cpu_to_le16(le32_to_cpu(io_req->DataCount) + sizeof(io_req->Pad));
+
+	inc_rfc1001_len(io_req, reparse_iov->iov_len);
+
+	in_iov[0].iov_base = (char *)io_req;
+	in_iov[0].iov_len = io_req_len;
+	in_iov[1] = *reparse_iov;
+	rc = SendReceive2(xid, tcon->ses, in_iov, ARRAY_SIZE(in_iov), &buf_type,
+			  CIFS_NO_RSP_BUF, &out_iov);
+
+	cifs_buf_release(io_req);
+
+	if (!rc)
+		rc = cifs_get_inode_info(&new, full_path, data, sb, xid, NULL);
+
+out_close:
+	CIFSSMBClose(xid, tcon, fid.netfid);
+
+	/*
+	 * If CREATE was successful but FSCTL_SET_REPARSE_POINT failed then
+	 * remove the intermediate object created by CREATE. Otherwise
+	 * empty object stay on the server when reparse call failed.
+	 */
+	if (rc)
+		CIFSSMBDelFile(xid, tcon, full_path, cifs_sb, NULL);
+
+	return rc ? ERR_PTR(rc) : new;
+}
+
 int
 CIFSSMB_set_compression(const unsigned int xid, struct cifs_tcon *tcon,
 		    __u16 fid)

fs/smb/client/link.c

@@ -19,6 +19,7 @@
 #include "smb2proto.h"
 #include "cifs_ioctl.h"
 #include "fs_context.h"
+#include "reparse.h"
 
 /*
  * M-F Symlink Functions - Begin
@@ -570,7 +571,6 @@ cifs_symlink(struct mnt_idmap *idmap, struct inode *inode,
 	int rc = -EOPNOTSUPP;
 	unsigned int xid;
 	struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
-	struct TCP_Server_Info *server;
 	struct tcon_link *tlink;
 	struct cifs_tcon *pTcon;
 	const char *full_path;
@@ -593,7 +593,6 @@ cifs_symlink(struct mnt_idmap *idmap, struct inode *inode,
 		goto symlink_exit;
 	}
 	pTcon = tlink_tcon(tlink);
-	server = cifs_pick_channel(pTcon->ses);
 
 	full_path = build_path_from_dentry(direntry, page);
 	if (IS_ERR(full_path)) {
@@ -643,13 +642,9 @@ cifs_symlink(struct mnt_idmap *idmap, struct inode *inode,
 	case CIFS_SYMLINK_TYPE_NATIVE:
 	case CIFS_SYMLINK_TYPE_NFS:
 	case CIFS_SYMLINK_TYPE_WSL:
-		if (server->ops->create_reparse_symlink &&
-		    (le32_to_cpu(pTcon->fsAttrInfo.Attributes) & FILE_SUPPORTS_REPARSE_POINTS)) {
-			rc = server->ops->create_reparse_symlink(xid, inode,
-								 direntry,
-								 pTcon,
-								 full_path,
-								 symname);
+		if (le32_to_cpu(pTcon->fsAttrInfo.Attributes) & FILE_SUPPORTS_REPARSE_POINTS) {
+			rc = create_reparse_symlink(xid, inode, direntry, pTcon,
+						    full_path, symname);
 			goto symlink_exit;
 		}
 		break;

fs/smb/client/reparse.c

@@ -34,7 +34,7 @@ static int detect_directory_symlink_target(struct cifs_sb_info *cifs_sb,
 					   const char *symname,
 					   bool *directory);
 
-int smb2_create_reparse_symlink(const unsigned int xid, struct inode *inode,
+int create_reparse_symlink(const unsigned int xid, struct inode *inode,
 				struct dentry *dentry, struct cifs_tcon *tcon,
 				const char *full_path, const char *symname)
 {
@@ -227,7 +227,8 @@ static int create_native_symlink(const unsigned int xid, struct inode *inode,
 
 	iov.iov_base = buf;
 	iov.iov_len = len;
-	new = smb2_get_reparse_inode(&data, inode->i_sb, xid,
+	new = tcon->ses->server->ops->create_reparse_inode(
+				     &data, inode->i_sb, xid,
 				     tcon, full_path, directory,
 				     &iov, NULL);
 	if (!IS_ERR(new))
@@ -399,7 +400,8 @@ static int create_native_socket(const unsigned int xid, struct inode *inode,
 	struct inode *new;
 	int rc = 0;
 
-	new = smb2_get_reparse_inode(&data, inode->i_sb, xid,
+	new = tcon->ses->server->ops->create_reparse_inode(
+				     &data, inode->i_sb, xid,
 				     tcon, full_path, false, &iov, NULL);
 	if (!IS_ERR(new))
 		d_instantiate(dentry, new);
@@ -492,7 +494,8 @@ static int mknod_nfs(unsigned int xid, struct inode *inode,
 		.symlink_target = kstrdup(symname, GFP_KERNEL),
 	};
 
-	new = smb2_get_reparse_inode(&data, inode->i_sb, xid,
+	new = tcon->ses->server->ops->create_reparse_inode(
+				     &data, inode->i_sb, xid,
 				     tcon, full_path, false, &iov, NULL);
 	if (!IS_ERR(new))
 		d_instantiate(dentry, new);
@@ -685,7 +688,8 @@ static int mknod_wsl(unsigned int xid, struct inode *inode,
 	memcpy(data.wsl.eas, &cc->ea, len);
 	data.wsl.eas_len = len;
 
-	new = smb2_get_reparse_inode(&data, inode->i_sb,
+	new = tcon->ses->server->ops->create_reparse_inode(
+				     &data, inode->i_sb,
 				     xid, tcon, full_path, false,
 				     &reparse_iov, &xattr_iov);
 	if (!IS_ERR(new))
@@ -698,7 +702,7 @@ static int mknod_wsl(unsigned int xid, struct inode *inode,
 	return rc;
 }
 
-int smb2_mknod_reparse(unsigned int xid, struct inode *inode,
+int mknod_reparse(unsigned int xid, struct inode *inode,
 		       struct dentry *dentry, struct cifs_tcon *tcon,
 		       const char *full_path, umode_t mode, dev_t dev)
 {

fs/smb/client/reparse.h

@@ -129,10 +129,10 @@ static inline bool cifs_open_data_reparse(struct cifs_open_info_data *data)
 bool cifs_reparse_point_to_fattr(struct cifs_sb_info *cifs_sb,
 				 struct cifs_fattr *fattr,
 				 struct cifs_open_info_data *data);
-int smb2_create_reparse_symlink(const unsigned int xid, struct inode *inode,
+int create_reparse_symlink(const unsigned int xid, struct inode *inode,
 				struct dentry *dentry, struct cifs_tcon *tcon,
 				const char *full_path, const char *symname);
-int smb2_mknod_reparse(unsigned int xid, struct inode *inode,
+int mknod_reparse(unsigned int xid, struct inode *inode,
 		       struct dentry *dentry, struct cifs_tcon *tcon,
 		       const char *full_path, umode_t mode, dev_t dev);
 struct reparse_data_buffer *smb2_get_reparse_point_buffer(const struct kvec *rsp_iov, u32 *len);

fs/smb/client/smb1ops.c

@@ -16,6 +16,7 @@
 #include "fs_context.h"
 #include "nterr.h"
 #include "smberr.h"
+#include "reparse.h"
 
 /*
  * An NT cancel request header looks just like the original request except:
@@ -1263,17 +1264,26 @@ cifs_make_node(unsigned int xid, struct inode *inode,
 		if (rc == 0)
 			d_instantiate(dentry, newinode);
 		return rc;
+	} else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL) {
+		/*
+		 * Check if mounted with mount parm 'sfu' mount parm.
+		 * SFU emulation should work with all servers
+		 * and was used by default in earlier versions of Windows.
+		 */
+		return cifs_sfu_make_node(xid, inode, dentry, tcon,
+					  full_path, mode, dev);
+	} else if (le32_to_cpu(tcon->fsAttrInfo.Attributes) & FILE_SUPPORTS_REPARSE_POINTS) {
+		/*
+		 * mknod via reparse points requires server support for
+		 * storing reparse points, which is available since
+		 * Windows 2000, but was not widely used until release
+		 * of Windows Server 2012 by the Windows NFS server.
+		 */
+		return mknod_reparse(xid, inode, dentry, tcon,
+				     full_path, mode, dev);
+	} else {
+		return -EOPNOTSUPP;
 	}
-	/*
-	 * Check if mounted with mount parm 'sfu' mount parm.
-	 * SFU emulation should work with all servers, but only
-	 * supports block and char device, socket & fifo,
-	 * and was used by default in earlier versions of Windows
-	 */
-	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL))
-		return -EPERM;
-	return cifs_sfu_make_node(xid, inode, dentry, tcon,
-				  full_path, mode, dev);
 }
 
 static bool
@@ -1370,6 +1380,7 @@ struct smb_version_operations smb1_operations = {
 	.create_hardlink = CIFSCreateHardLink,
 	.query_symlink = cifs_query_symlink,
 	.get_reparse_point_buffer = cifs_get_reparse_point_buffer,
+	.create_reparse_inode = cifs_create_reparse_inode,
 	.open = cifs_open_file,
 	.set_fid = cifs_set_fid,
 	.close = cifs_close_file,

fs/smb/client/smb2inode.c

@@ -1321,7 +1321,7 @@ smb2_set_file_info(struct inode *inode, const char *full_path,
 	return rc;
 }
 
-struct inode *smb2_get_reparse_inode(struct cifs_open_info_data *data,
+struct inode *smb2_create_reparse_inode(struct cifs_open_info_data *data,
 				     struct super_block *sb,
 				     const unsigned int xid,
 				     struct cifs_tcon *tcon,

fs/smb/client/smb2ops.c

@@ -5262,7 +5262,7 @@ static int smb2_make_node(unsigned int xid, struct inode *inode,
 					full_path, mode, dev);
 	} else if ((le32_to_cpu(tcon->fsAttrInfo.Attributes) & FILE_SUPPORTS_REPARSE_POINTS)
 		|| (tcon->posix_extensions)) {
-		rc = smb2_mknod_reparse(xid, inode, dentry, tcon,
+		rc = mknod_reparse(xid, inode, dentry, tcon,
 					full_path, mode, dev);
 	}
 	return rc;
@@ -5321,7 +5321,7 @@ struct smb_version_operations smb20_operations = {
 	.get_reparse_point_buffer = smb2_get_reparse_point_buffer,
 	.query_mf_symlink = smb3_query_mf_symlink,
 	.create_mf_symlink = smb3_create_mf_symlink,
-	.create_reparse_symlink = smb2_create_reparse_symlink,
+	.create_reparse_inode = smb2_create_reparse_inode,
 	.open = smb2_open_file,
 	.set_fid = smb2_set_fid,
 	.close = smb2_close_file,
@@ -5424,7 +5424,7 @@ struct smb_version_operations smb21_operations = {
 	.get_reparse_point_buffer = smb2_get_reparse_point_buffer,
 	.query_mf_symlink = smb3_query_mf_symlink,
 	.create_mf_symlink = smb3_create_mf_symlink,
-	.create_reparse_symlink = smb2_create_reparse_symlink,
+	.create_reparse_inode = smb2_create_reparse_inode,
 	.open = smb2_open_file,
 	.set_fid = smb2_set_fid,
 	.close = smb2_close_file,
@@ -5531,7 +5531,7 @@ struct smb_version_operations smb30_operations = {
 	.get_reparse_point_buffer = smb2_get_reparse_point_buffer,
 	.query_mf_symlink = smb3_query_mf_symlink,
 	.create_mf_symlink = smb3_create_mf_symlink,
-	.create_reparse_symlink = smb2_create_reparse_symlink,
+	.create_reparse_inode = smb2_create_reparse_inode,
 	.open = smb2_open_file,
 	.set_fid = smb2_set_fid,
 	.close = smb2_close_file,
@@ -5647,7 +5647,7 @@ struct smb_version_operations smb311_operations = {
 	.get_reparse_point_buffer = smb2_get_reparse_point_buffer,
 	.query_mf_symlink = smb3_query_mf_symlink,
 	.create_mf_symlink = smb3_create_mf_symlink,
-	.create_reparse_symlink = smb2_create_reparse_symlink,
+	.create_reparse_inode = smb2_create_reparse_inode,
 	.open = smb2_open_file,
 	.set_fid = smb2_set_fid,
 	.close = smb2_close_file,