From: Matthew Dillon <dillon@apollo.backplane.com>
Date: Sun, 21 Jun 2009 02:25:26 +0000 (-0700)
Subject: cpdup - Do not create a .tmp file and rename if the target does not exist.
X-Git-Tag: v2.3.2~126
X-Git-Url: http://gitweb.dragonflybsd.org/dragonfly.git/commitdiff_plain/0e9fad5e47425d0753278b41e5169f5b8c50799d

cpdup - Do not create a .tmp file and rename if the target does not exist.

* When copying if the target does not exist use the target's actual name
  instead of the name of a temporary file.

  This helps filesystems (aka HAMMER) which use hashed directories.  Inode
  numbers can be selected by the FS on the basis of the file-name in
  order to maintain directory-order linearity.  If the copy program creates
  the target file with one name and then renames it to the real name,
  however, the feature is lost and we get one big scramble again.
---

diff --git a/bin/cpdup/cpdup.c b/bin/cpdup/cpdup.c
index 99e02db..2f5a5d9 100644
--- a/bin/cpdup/cpdup.c
+++ b/bin/cpdup/cpdup.c
@@ -1114,7 +1114,10 @@ relink:
 	int fd1;
 	int fd2;
 
-	path = mprintf("%s.tmp%d", dpath, (int)getpid());
+	if (st2Valid)
+		path = mprintf("%s.tmp%d", dpath, (int)getpid());
+	else
+		path = mprintf("%s", dpath);
 
 	/*
 	 * Handle check failure message.
@@ -1198,7 +1201,7 @@ relink:
 #else
 		    hc_utimes(&DstHost, path, tv);
 #endif
-		    if (xrename(path, dpath, st2_flags) != 0) {
+		    if (st2Valid && xrename(path, dpath, st2_flags) != 0) {
 			logerr("%-32s rename-after-copy failed: %s\n",
 			    (dpath ? dpath : spath), strerror(errno)
 			);
@@ -1257,13 +1260,18 @@ skip_copy:
     } else if (S_ISLNK(st1.st_mode)) {
 	char *link1 = malloc(GETLINKSIZE);
 	char *link2 = malloc(GETLINKSIZE);
-	char *path = malloc(GETPATHSIZE);
+	char *path;
 	int n1;
 	int n2;
 
-	snprintf(path, GETPATHSIZE, "%s.tmp%d", dpath, (int)getpid());
 	n1 = hc_readlink(&SrcHost, spath, link1, GETLINKSIZE - 1);
-	n2 = hc_readlink(&DstHost, dpath, link2, GETLINKSIZE - 1);
+	if (st2Valid) {
+		path = mprintf("%s.tmp%d", dpath, (int)getpid());
+		n2 = hc_readlink(&DstHost, dpath, link2, GETLINKSIZE - 1);
+	} else {
+		path = mprintf("%s", dpath);
+		n2 = -1;
+	}
 	if (n1 >= 0) {
 	    if (ForceOpt || n1 != n2 || bcmp(link1, link2, n1) != 0) {
 		hc_umask(&DstHost, ~st1.st_mode);
@@ -1281,7 +1289,7 @@ skip_copy:
 		     * there is no lchmod() or lchflags(), we 
 		     * cannot chmod or chflags a softlink.
 		     */
-		    if (xrename(path, dpath, st2_flags) != 0) {
+		    if (st2Valid && xrename(path, dpath, st2_flags) != 0) {
 			logerr("%-32s rename softlink (%s->%s) failed: %s\n",
 			    (dpath ? dpath : spath),
 			    path, dpath, strerror(errno));
@@ -1309,7 +1317,7 @@ skip_copy:
 	free(link2);
 	free(path);
     } else if ((S_ISCHR(st1.st_mode) || S_ISBLK(st1.st_mode)) && DeviceOpt) {
-	char *path = malloc(GETPATHSIZE);
+	char *path = NULL;
 
 	if (ForceOpt ||
 	    st2Valid == 0 || 
@@ -1318,14 +1326,19 @@ skip_copy:
 	    st1.st_uid != st2.st_uid ||
 	    st1.st_gid != st2.st_gid
 	) {
-	    snprintf(path, GETPATHSIZE, "%s.tmp%d", dpath, (int)getpid());
+	    if (st2Valid) {
+		path = mprintf("%s.tmp%d", dpath, (int)getpid());
+		xremove(&DstHost, path);
+	    } else {
+		path = mprintf("%s", dpath);
+	    }
 
-	    xremove(&DstHost, path);
 	    if (hc_mknod(&DstHost, path, st1.st_mode, st1.st_rdev) == 0) {
 		hc_chmod(&DstHost, path, st1.st_mode);
 		hc_chown(&DstHost, path, st1.st_uid, st1.st_gid);
-		xremove(&DstHost, dpath);
-		if (xrename(path, dpath, st2_flags) != 0) {
+		if (st2Valid)
+			xremove(&DstHost, dpath);
+		if (st2Valid && xrename(path, dpath, st2_flags) != 0) {
 		    logerr("%-32s dev-rename-after-create failed: %s\n",
 			(dpath ? dpath : spath),
 			strerror(errno)
@@ -1344,7 +1357,8 @@ skip_copy:
 	    if (VerboseOpt >= 3)
 		logstd("%-32s nochange\n", (dpath ? dpath : spath));
 	}
-	free(path);
+	if (path)
+		free(path);
 	CountSourceItems++;
     }
 done: