OS-3894 want librename

Reviewed by: Jerry Jelinek <jerry.jelinek@joyent.com>

manifest

@@ -4892,6 +4892,7 @@ f usr/lib/amd64/libraidcfg.so.1 0755 root bin
 s usr/lib/amd64/libraidcfg.so=libraidcfg.so.1
 s usr/lib/amd64/librcm.so.1=../../../lib/amd64/librcm.so.1
 s usr/lib/amd64/librcm.so=../../../lib/amd64/librcm.so.1
+f usr/lib/amd64/librename.so.1 0755 root bin
 f usr/lib/amd64/libreparse.so.1 0755 root bin
 s usr/lib/amd64/libreparse.so=libreparse.so.1
 s usr/lib/amd64/libresolv.so.2=../../../lib/amd64/libresolv.so.2
@@ -6340,6 +6341,7 @@ s usr/lib/librcm.so.1=../../lib/librcm.so.1
 s usr/lib/librcm.so=../../lib/librcm.so.1
 f usr/lib/librdc.so.1 0755 root bin
 s usr/lib/librdc.so=librdc.so.1
+f usr/lib/librename.so.1 0755 root bin
 f usr/lib/libreparse.so.1 0755 root bin
 s usr/lib/libreparse.so=libreparse.so.1
 s usr/lib/libresolv.so.1=../../lib/libresolv.so.1

usr/src/lib/Makefile

@@ -137,6 +137,7 @@ SUBDIRS += \
 	libpp		\
 	libproc		\
 	libproject	\
+	librename	\
 	libsendfile	\
 	nametoaddr	\
 	ncad_addr	\
@@ -435,6 +436,7 @@ HDRSUBDIRS=		\
 	libraidcfg	\
 	librcm		\
 	librdc		\
+	librename	\
 	libscf		\
 	libsip		\
 	libsmbios	\

usr/src/lib/librename/Makefile

@@ -0,0 +1,44 @@
+#
+# This file and its contents are supplied under the terms of the
+# Common Development and Distribution License ("CDDL"), version 1.0.
+# You may only use this file in accordance with the terms of version
+# 1.0 of the CDDL.
+#
+# A full copy of the text of the CDDL should have accompanied this
+# source.  A copy of the CDDL is also available via the Internet at
+# http://www.illumos.org/license/CDDL.
+#
+
+#
+# Copyright (c) 2014 Joyent, Inc.  All rights reserved.
+#
+
+include		../Makefile.lib
+
+HDRS =		librename.h
+HDRDIR =	common
+SUBDIRS =	$(MACH)
+$(BUILD64)SUBDIRS +=	$(MACH64)
+
+all :=		TARGET = all
+clean :=	TARGET = clean
+clobber :=	TARGET = clobber
+install :=	TARGET = install
+lint :=		TARGET = lint
+
+.KEEP_STATE:
+
+all clean clobber lint: $(SUBDIRS)
+
+install: 	$(SUBDIRS) $(VARPD_MAPFILES) install_h
+
+install_h: 	$(ROOTHDRS)
+
+check:		$(CHECKHDRS)
+
+$(SUBDIRS):  FRC
+	@cd $@; pwd; $(MAKE) $(TARGET)
+
+FRC:
+
+include ../Makefile.targ

usr/src/lib/librename/Makefile.com

@@ -0,0 +1,34 @@
+#
+# This file and its contents are supplied under the terms of the
+# Common Development and Distribution License ("CDDL"), version 1.0.
+# You may only use this file in accordance with the terms of version
+# 1.0 of the CDDL.
+#
+# A full copy of the text of the CDDL should have accompanied this
+# source.  A copy of the CDDL is also available via the Internet at
+# http://www.illumos.org/license/CDDL.
+#
+
+#
+# Copyright (c) 2014 Joyent, Inc.  All rights reserved.
+#
+
+LIBRARY =	librename.a
+VERS =		.1
+OBJECTS =	librename.o \
+
+include ../../Makefile.lib
+
+LIBS =		$(DYNLIB) $(LINTLIB)
+LDLIBS +=	-lc
+CPPFLAGS +=	-I../common
+
+SRCDIR =	../common
+
+.KEEP_STATE:
+
+all:	$(LIBS)
+
+lint:	lintcheck
+
+include ../../Makefile.targ

usr/src/lib/librename/amd64/Makefile

@@ -0,0 +1,19 @@
+#
+# This file and its contents are supplied under the terms of the
+# Common Development and Distribution License ("CDDL"), version 1.0.
+# You may only use this file in accordance with the terms of version
+# 1.0 of the CDDL.
+#
+# A full copy of the text of the CDDL should have accompanied this
+# source.  A copy of the CDDL is also available via the Internet at
+# http://www.illumos.org/license/CDDL.
+#
+
+#
+# Copyright (c) 2014 Joyent, Inc.  All rights reserved.
+#
+
+include ../Makefile.com
+include ../../Makefile.lib.64
+
+install: all $(ROOTLIBS64) $(ROOTLINKS64) $(ROOTLINT64)

usr/src/lib/librename/common/librename.c

@@ -0,0 +1,229 @@
+/*
+ * This file and its contents are supplied under the terms of the
+ * Common Development and Distribution License ("CDDL"), version 1.0.
+ * You may only use this file in accordance with the terms of version
+ * 1.0 of the CDDL.
+ *
+ * A full copy of the text of the CDDL should have accompanied this
+ * source.  A copy of the CDDL is also available via the Internet at
+ * http://www.illumos.org/license/CDDL.
+ */
+
+/*
+ * Copyright (c) 2014 Joyent, Inc.  All rights reserved.
+ */
+
+/*
+ * Implementation of librename(3RENAME) interfaces.
+ */
+
+#include <librename.h>
+
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <synch.h>
+
+typedef enum librename_atomic_state {
+	LIBRENAME_ATOMIC_INITIAL = 0x0,
+	LIBRENAME_ATOMIC_FSYNC,
+	LIBRENAME_ATOMIC_RENAME,
+	LIBRENAME_ATOMIC_POSTSYNC,
+	LIBRENAME_ATOMIC_COMPLETED
+} librename_atomic_state_t;
+
+struct librename_atomic {
+	char *lra_fname;			/* RO */
+	char *lra_altname;			/* RO */
+	int lra_dirfd;				/* RO */
+	int lra_tmpfd;				/* RO */
+	mutex_t lra_lock;
+	librename_atomic_state_t lra_state;	/* lra_lock */
+};
+
+int
+librename_atomic_fdinit(int fd, const char *file, const char *prefix,
+    int mode, int flags, librename_atomic_t **outp)
+{
+	int ret;
+	int oflags;
+	librename_atomic_t *lrap;
+	struct stat st;
+
+	if (fd < 0 || file == NULL || outp == NULL)
+		return (EINVAL);
+
+	if (flags & ~(LIBRENAME_ATOMIC_NOUNLINK | LIBRENAME_ATOMIC_CLOEXEC))
+		return (EINVAL);
+
+	if (strchr(file, '/') != NULL)
+		return (EINVAL);
+
+	if (prefix != NULL && strchr(prefix, '/') != NULL)
+		return (EINVAL);
+
+	*outp = NULL;
+	lrap = malloc(sizeof (librename_atomic_t));
+	if (lrap == NULL)
+		return (errno);
+
+	if (fstat(fd, &st) != 0) {
+		ret = errno;
+		free(lrap);
+		return (ret);
+	}
+
+	if (!S_ISDIR(st.st_mode)) {
+		free(lrap);
+		return (ENOTDIR);
+	}
+
+	if ((lrap->lra_dirfd = dup(fd)) == -1) {
+		ret = errno;
+		free(lrap);
+		return (ret);
+	}
+
+
+	lrap->lra_fname = strdup(file);
+	if (lrap->lra_fname == NULL) {
+		ret = errno;
+		if (close(lrap->lra_dirfd) != 0)
+			abort();
+		free(lrap);
+		return (ret);
+	}
+
+	if (prefix == NULL) {
+		ret = asprintf(&lrap->lra_altname, ".%d.%s", (int)getpid(),
+		    file);
+	} else {
+		ret = asprintf(&lrap->lra_altname, "%s%s", prefix, file);
+	}
+	if (ret == -1) {
+		ret = errno;
+		free(lrap->lra_fname);
+		if (close(lrap->lra_dirfd) != 0)
+			abort();
+		free(lrap);
+		return (errno);
+	}
+
+	oflags = O_CREAT | O_TRUNC | O_RDWR | O_NOFOLLOW;
+	if (flags & LIBRENAME_ATOMIC_NOUNLINK)
+		oflags |= O_EXCL;
+
+	if (flags & LIBRENAME_ATOMIC_CLOEXEC)
+		oflags |= O_CLOEXEC;
+
+	lrap->lra_tmpfd = openat(lrap->lra_dirfd, lrap->lra_altname,
+	    oflags, mode);
+	if (lrap->lra_tmpfd < 0) {
+		ret = errno;
+		free(lrap->lra_altname);
+		free(lrap->lra_fname);
+		if (close(lrap->lra_dirfd) != 0)
+			abort();
+		free(lrap);
+		return (ret);
+	}
+
+	if (mutex_init(&lrap->lra_lock, USYNC_THREAD, NULL) != 0)
+		abort();
+
+	lrap->lra_state = LIBRENAME_ATOMIC_INITIAL;
+	*outp = lrap;
+	return (0);
+}
+
+int
+librename_atomic_init(const char *dir, const char *file, const char *prefix,
+    int mode, int flags, librename_atomic_t **outp)
+{
+	int fd, ret;
+
+	if ((fd = open(dir, O_RDONLY)) < 0)
+		return (errno);
+
+	ret = librename_atomic_fdinit(fd, file, prefix, mode, flags, outp);
+	if (close(fd) != 0)
+		abort();
+
+	return (ret);
+}
+
+int
+librename_atomic_fd(librename_atomic_t *lrap)
+{
+	return (lrap->lra_tmpfd);
+}
+
+/*
+ * To atomically commit a file, we need to go through and do the following:
+ *
+ *  o fsync the source
+ *  o run rename
+ *  o fsync the source again and the directory.
+ */
+int
+librename_atomic_commit(librename_atomic_t *lrap)
+{
+	int ret = 0;
+
+	if (mutex_lock(&lrap->lra_lock) != 0)
+		abort();
+	if (lrap->lra_state == LIBRENAME_ATOMIC_COMPLETED) {
+		ret = EINVAL;
+		goto out;
+	}
+
+	if (fsync(lrap->lra_tmpfd) != 0) {
+		ret = errno;
+		goto out;
+	}
+	lrap->lra_state = LIBRENAME_ATOMIC_FSYNC;
+
+	if (renameat(lrap->lra_dirfd, lrap->lra_altname, lrap->lra_dirfd,
+	    lrap->lra_fname) != 0) {
+		ret = errno;
+		goto out;
+	}
+	lrap->lra_state = LIBRENAME_ATOMIC_RENAME;
+
+	if (fsync(lrap->lra_tmpfd) != 0) {
+		ret = errno;
+		goto out;
+	}
+	lrap->lra_state = LIBRENAME_ATOMIC_POSTSYNC;
+
+	if (fsync(lrap->lra_dirfd) != 0) {
+		ret = errno;
+		goto out;
+	}
+	lrap->lra_state = LIBRENAME_ATOMIC_COMPLETED;
+
+out:
+	if (mutex_unlock(&lrap->lra_lock) != 0)
+		abort();
+	return (ret);
+}
+
+void
+librename_atomic_fini(librename_atomic_t *lrap)
+{
+
+	free(lrap->lra_altname);
+	free(lrap->lra_fname);
+	if (close(lrap->lra_tmpfd) != 0)
+		abort();
+	if (close(lrap->lra_dirfd) != 0)
+		abort();
+	if (mutex_destroy(&lrap->lra_lock) != 0)
+		abort();
+	free(lrap);
+}