[CIFS] Add compat with SFU (part 1)

This should help the case of creating fifos and other special files to
servers which do not support the Unix extensions.

Signed-off-by: Steve French (sfrench@us.ibm.com)

Thanks to Martin Koeppe for his suggestions and good analysis

fs/cifs/cifs_fs_sb.h

@@ -25,6 +25,7 @@
 #define CIFS_MOUNT_NO_XATTR  0x10 /* if set - disable xattr support */
 #define CIFS_MOUNT_MAP_SPECIAL_CHR 0x20 /* remap illegal chars in filenames */
 #define CIFS_MOUNT_POSIX_PATHS 0x40 /* Negotiate posix pathnames if possible. */
+#define CIFS_MOUNT_UNX_EMUL    0x80 /* Network compat with SFUnix emulation */
 
 struct cifs_sb_info {
 	struct cifsTconInfo *tcon;	/* primary mount */

fs/cifs/connect.c

@@ -75,6 +75,7 @@ struct smb_vol {
 	unsigned direct_io:1;
 	unsigned remap:1;   /* set to remap seven reserved chars in filenames */
 	unsigned posix_paths:1;   /* unset to not ask for posix pathnames. */
+	unsigned sfu_emul:1;
 	unsigned int rsize;
 	unsigned int wsize;
 	unsigned int sockopt;
@@ -1027,6 +1028,10 @@ cifs_parse_mount_options(char *options, const char *devname,struct smb_vol *vol)
 			vol->remap = 1;
 		} else if (strnicmp(data, "nomapchars", 10) == 0) {
 			vol->remap = 0;
+                } else if (strnicmp(data, "sfu", 3) == 0) {
+                        vol->sfu_emul = 1;
+                } else if (strnicmp(data, "nosfu", 5) == 0) {
+                        vol->sfu_emul = 0;
 		} else if (strnicmp(data, "posixpaths", 10) == 0) {
 			vol->posix_paths = 1;
 		} else if (strnicmp(data, "noposixpaths", 12) == 0) {
@@ -1687,6 +1692,8 @@ cifs_mount(struct super_block *sb, struct cifs_sb_info *cifs_sb,
 			cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_MAP_SPECIAL_CHR;
 		if(volume_info.no_xattr)
 			cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_NO_XATTR;
+		if(volume_info.sfu_emul)
+			cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_UNX_EMUL;
 
 		if(volume_info.direct_io) {
 			cERROR(1,("mounting share using direct i/o"));

fs/cifs/dir.c

@@ -209,7 +209,7 @@ cifs_create(struct inode *inode, struct dentry *direntry, int mode,
 						CIFS_MOUNT_MAP_SPECIAL_CHR);
 			}
 		else {
-			/* BB implement via Windows security descriptors */
+			/* BB implement mode setting via Windows security descriptors */
 			/* eg CIFSSMBWinSetPerms(xid,pTcon,full_path,mode,-1,-1,local_nls);*/
 			/* could set r/o dos attribute if mode & 0222 == 0 */
 		}
@@ -326,6 +326,16 @@ int cifs_mknod(struct inode *inode, struct dentry *direntry, int mode, dev_t dev
 			if(rc == 0)
 				d_instantiate(direntry, newinode);
 		}
+	} else {
+		if((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL) && 
+			(special_file(mode))) {
+
+			cFYI(1,("sfu compat create special file"));
+			/*	Attributes = cpu_to_le32(ATTR_SYSTEM); 
+				rc = CIFSSMBOpen(xid, pTcon, full_path, disposition, ...); */
+
+			/* add code here to set EAs */
+		}
 	}
 
 	kfree(full_path);