CIFS: make mknod() an smb_version_op

This cleanup removes cifs specific code from SMB2/SMB3 code paths
which is cleaner and easier to maintain as the code to handle
special files is improved.  Below is an example creating special files
using 'sfu' mount option over SMB3 to Windows (with this patch)
(Note that to Samba server, support for saving dos attributes
has to be enabled for the SFU mount option to work).

In the future this will also make implementation of creating
special files as reparse points easier (as Windows NFS server does
for example).

   root@smf-Thinkpad-P51:~# stat -c "%F" /mnt2/char
   character special file

   root@smf-Thinkpad-P51:~# stat -c "%F" /mnt2/block
   block special file

Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>

1 files changed, 3 insertions, 104 deletions

diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index 907e85d65bb4..f26a48dd2e39 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -621,20 +621,10 @@ int cifs_mknod(struct inode *inode, struct dentry *direntry, umode_t mode,
 {
 	int rc = -EPERM;
 	unsigned int xid;
-	int create_options = CREATE_NOT_DIR | CREATE_OPTION_SPECIAL;
 	struct cifs_sb_info *cifs_sb;
 	struct tcon_link *tlink;
 	struct cifs_tcon *tcon;
-	struct cifs_io_parms io_parms;
 	char *full_path = NULL;
-	struct inode *newinode = NULL;
-	__u32 oplock = 0;
-	struct cifs_fid fid;
-	struct cifs_open_parms oparms;
-	FILE_ALL_INFO *buf = NULL;
-	unsigned int bytes_written;
-	struct win_dev *pdev;
-	struct kvec iov[2];
 
 	if (!old_valid_dev(device_number))
 		return -EINVAL;
@@ -654,103 +644,12 @@ int cifs_mknod(struct inode *inode, struct dentry *direntry, umode_t mode,
 		goto mknod_out;
 	}
 
-	if (tcon->unix_ext) {
-		struct cifs_unix_set_info_args args = {
-			.mode	= mode & ~current_umask(),
-			.ctime	= NO_CHANGE_64,
-			.atime	= NO_CHANGE_64,
-			.mtime	= NO_CHANGE_64,
-			.device	= device_number,
-		};
-		if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SET_UID) {
-			args.uid = current_fsuid();
-			args.gid = current_fsgid();
-		} else {
-			args.uid = INVALID_UID; /* no change */
-			args.gid = INVALID_GID; /* no change */
-		}
-		rc = CIFSSMBUnixSetPathInfo(xid, tcon, full_path, &args,
-					    cifs_sb->local_nls,
-					    cifs_remap(cifs_sb));
-		if (rc)
-			goto mknod_out;
-
-		rc = cifs_get_inode_info_unix(&newinode, full_path,
-						inode->i_sb, xid);
-
-		if (rc == 0)
-			d_instantiate(direntry, newinode);
-		goto mknod_out;
-	}
-
-	if (!S_ISCHR(mode) && !S_ISBLK(mode))
-		goto mknod_out;
-
-	if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL))
-		goto mknod_out;
-
-
-	cifs_dbg(FYI, "sfu compat create special file\n");
-
-	buf = kmalloc(sizeof(FILE_ALL_INFO), GFP_KERNEL);
-	if (buf == NULL) {
-		rc = -ENOMEM;
-		goto mknod_out;
-	}
-
-	if (backup_cred(cifs_sb))
-		create_options |= CREATE_OPEN_BACKUP_INTENT;
-
-	oparms.tcon = tcon;
-	oparms.cifs_sb = cifs_sb;
-	oparms.desired_access = GENERIC_WRITE;
-	oparms.create_options = create_options;
-	oparms.disposition = FILE_CREATE;
-	oparms.path = full_path;
-	oparms.fid = &fid;
-	oparms.reconnect = false;
-
-	if (tcon->ses->server->oplocks)
-		oplock = REQ_OPLOCK;
-	else
-		oplock = 0;
-	rc = tcon->ses->server->ops->open(xid, &oparms, &oplock, buf);
-	if (rc)
-		goto mknod_out;
-
-	/*
-	 * BB Do not bother to decode buf since no local inode yet to put
-	 * timestamps in, but we can reuse it safely.
-	 */
-
-	pdev = (struct win_dev *)buf;
-	io_parms.pid = current->tgid;
-	io_parms.tcon = tcon;
-	io_parms.offset = 0;
-	io_parms.length = sizeof(struct win_dev);
-	iov[1].iov_base = buf;
-	iov[1].iov_len = sizeof(struct win_dev);
-	if (S_ISCHR(mode)) {
-		memcpy(pdev->type, "IntxCHR", 8);
-		pdev->major = cpu_to_le64(MAJOR(device_number));
-		pdev->minor = cpu_to_le64(MINOR(device_number));
-		rc = tcon->ses->server->ops->sync_write(xid, &fid, &io_parms,
-							&bytes_written, iov, 1);
-	} else if (S_ISBLK(mode)) {
-		memcpy(pdev->type, "IntxBLK", 8);
-		pdev->major = cpu_to_le64(MAJOR(device_number));
-		pdev->minor = cpu_to_le64(MINOR(device_number));
-		rc = tcon->ses->server->ops->sync_write(xid, &fid, &io_parms,
-							&bytes_written, iov, 1);
-	}
-	tcon->ses->server->ops->close(xid, tcon, &fid);
-	d_drop(direntry);
-
-	/* FIXME: add code here to set EAs */
+	rc = tcon->ses->server->ops->make_node(xid, inode, direntry, tcon,
+					       full_path, mode,
+					       device_number);
 
 mknod_out:
 	kfree(full_path);
-	kfree(buf);
 	free_xid(xid);
 	cifs_put_tlink(tlink);
 	return rc;