Allow mknod and mkfifo on SMB2/SMB3 mounts

The "sfu" mount option did not work on SMB2/SMB3 mounts.
With these changes when the "sfu" mount option is passed in
on an smb2/smb2.1/smb3 mount the client can emulate (and
recognize) fifo and device (character and device files).

In addition the "sfu" mount option should not conflict
with "mfsymlinks" (symlink emulation) as we will never
create "sfu" style symlinks, but using "sfu" mount option
will allow us to recognize existing symlinks, created with
Microsoft "Services for Unix" (SFU and SUA).

To enable the "sfu" mount option for SMB2/SMB3 the calling
syntax of the generic cifs/smb2/smb3 sync_read and sync_write
protocol dependent function needed to be changed (we
don't have a file struct in all cases), but this actually
ended up simplifying the code a little.

Signed-off-by: Steve French <smfrench@gmail.com>

1 files changed, 11 insertions, 4 deletions

diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 8fd4ee8..4ff36ea 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -412,7 +412,7 @@ cifs_sfu_type(struct cifs_fattr *fattr, const char *path,
 	      struct cifs_sb_info *cifs_sb, unsigned int xid)
 {
 	int rc;
-	int oplock = 0;
+	__u32 oplock;
 	struct tcon_link *tlink;
 	struct cifs_tcon *tcon;
 	struct cifs_fid fid;
@@ -451,8 +451,13 @@ cifs_sfu_type(struct cifs_fattr *fattr, const char *path,
 	oparms.fid = &fid;
 	oparms.reconnect = false;
 
-	rc = CIFS_open(xid, &oparms, &oplock, NULL);
+	if (tcon->ses->server->oplocks)
+		oplock = REQ_OPLOCK;
+	else
+		oplock = 0;
+	rc = tcon->ses->server->ops->open(xid, &oparms, &oplock, NULL);
 	if (rc) {
+		cifs_dbg(FYI, "check sfu type of %s, open rc = %d\n", path, rc);
 		cifs_put_tlink(tlink);
 		return rc;
 	}
@@ -464,7 +469,8 @@ cifs_sfu_type(struct cifs_fattr *fattr, const char *path,
 	io_parms.offset = 0;
 	io_parms.length = 24;
 
-	rc = CIFSSMBRead(xid, &io_parms, &bytes_read, &pbuf, &buf_type);
+	rc = tcon->ses->server->ops->sync_read(xid, &fid, &io_parms,
+					&bytes_read, &pbuf, &buf_type);
 	if ((rc == 0) && (bytes_read >= 8)) {
 		if (memcmp("IntxBLK", pbuf, 8) == 0) {
 			cifs_dbg(FYI, "Block device\n");
@@ -504,7 +510,8 @@ cifs_sfu_type(struct cifs_fattr *fattr, const char *path,
 		fattr->cf_dtype = DT_REG;
 		rc = -EOPNOTSUPP; /* or some unknown SFU type */
 	}
-	CIFSSMBClose(xid, tcon, fid.netfid);
+
+	tcon->ses->server->ops->close(xid, tcon, &fid);
 	cifs_put_tlink(tlink);
 	return rc;
 }