initial import

lib9/create.c

@@ -0,0 +1,75 @@
+#define _GNU_SOURCE	/* for Linux O_DIRECT */
+#include <u.h>
+#define NOPLAN9DEFINES
+#include <sys/file.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <libc.h>
+#include <sys/stat.h>
+#ifndef O_DIRECT
+#define O_DIRECT 0
+#endif
+
+int
+p9create(char *path, int mode, ulong perm)
+{
+	int fd, cexec, umode, rclose, lock, rdwr;
+	struct flock fl;
+
+	rdwr = mode&3;
+	lock = mode&OLOCK;
+	cexec = mode&OCEXEC;
+	rclose = mode&ORCLOSE;
+	mode &= ~(ORCLOSE|OCEXEC|OLOCK);
+
+	/* XXX should get mode mask right? */
+	fd = -1;
+	if(perm&DMDIR){
+		if(mode != OREAD){
+			werrstr("bad mode in directory create");
+			goto out;
+		}
+		if(mkdir(path, perm&0777) < 0)
+			goto out;
+		fd = open(path, O_RDONLY);
+	}else{
+		umode = (mode&3)|O_CREAT|O_TRUNC;
+		mode &= ~(3|OTRUNC);
+		if(mode&ODIRECT){
+			umode |= O_DIRECT;
+			mode &= ~ODIRECT;
+		}
+		if(mode&OEXCL){
+			umode |= O_EXCL;
+			mode &= ~OEXCL;
+		}
+		if(mode&OAPPEND){
+			umode |= O_APPEND;
+			mode &= ~OAPPEND;
+		}
+		if(mode){
+			werrstr("unsupported mode in create");
+			goto out;
+		}
+		fd = open(path, umode, perm);
+	}
+out:
+	if(fd >= 0){
+		if(lock){
+			fl.l_type = (rdwr==OREAD) ? F_RDLCK : F_WRLCK;
+			fl.l_whence = SEEK_SET;
+			fl.l_start = 0;
+			fl.l_len = 0;
+			if(fcntl(fd, F_SETLK, &fl) < 0){
+				close(fd);
+				werrstr("lock: %r");
+				return -1;
+			}
+		}
+		if(cexec)
+			fcntl(fd, F_SETFL, FD_CLOEXEC);
+		if(rclose)
+			remove(path);
+	}
+	return fd;
+}