Merge branch 'fsync-shadow-files-before-rename' of https://github.com/awelzel/zeek

* 'fsync-shadow-files-before-rename' of https://github.com/awelzel/zeek:
  logging/writers/ascii: shadow files: Add fsync() before rename()

CHANGES

@@ -1,3 +1,11 @@
+4.2.0-dev.260 | 2021-10-15 09:45:45 +0100
+
+  * logging/writers/ascii: shadow files: Add fsync() before rename(). This
+    prevents potential problems with leftover files after unclean shutdowns.
+    (Arne Welzel, Corelight)
+
+  * Fix typo in typedef changes that broke tests on 32-bit Debian 9 (Tim Wojtulewicz, Corelight)
+
 4.2.0-dev.255 | 2021-10-12 09:22:37 -0700
 
   * Replace most uses of typedef with using for type aliasing (Tim Wojtulewicz, Corelight)

VERSION

@@ -1 +1 @@
-4.2.0-dev.255
+4.2.0-dev.260

src/logging/writers/ascii/Ascii.cc

@@ -465,7 +465,7 @@ bool Ascii::DoInit(const WriterInfo& info, int num_fields, const threading::Fiel
 
 			if ( sfd < 0 )
 				{
-				Error(Fmt("cannot open %s: %s", sfname.data(), Strerror(errno)));
+				Error(Fmt("cannot open %s: %s", tmp_sfname.data(), Strerror(errno)));
 				return false;
 				}
 
@@ -478,7 +478,7 @@ bool Ascii::DoInit(const WriterInfo& info, int num_fields, const threading::Fiel
 				util::safe_write(sfd, ppf, strlen(ppf));
 
 			util::safe_write(sfd, "\n", 1);
-
+			util::safe_fsync(sfd);
 			util::safe_close(sfd);
 
 			if ( rename(tmp_sfname.data(), sfname.data()) == -1 )

src/util.cc

@@ -2162,6 +2162,36 @@ bool safe_pwrite(int fd, const unsigned char* data, size_t len, size_t offset)
 	return true;
 	}
 
+bool safe_fsync(int fd)
+	{
+	int r;
+
+	/*
+	 * Failure cases of fsync(2) are EABDF, EINTR, ENOSPC, EROFS, EINVAL, EDQUOT.
+	 *
+	 * For EINTR, one can just retry until it is not interrupted. For the others
+	 * we report an error.
+	 *
+	 * Note that we don't use the reporter here to allow use from different threads.
+	 */
+	do
+		{
+		r = fsync(fd);
+		} while ( r < 0 && errno == EINTR );
+
+	if ( r < 0 )
+		{
+		char buf[128];
+		zeek_strerror_r(errno, buf, sizeof(buf));
+		fprintf(stderr, "safe_fsync error %d: %s\n", errno, buf);
+		abort();
+
+		return false;
+		}
+
+	return true;
+	}
+
 void safe_close(int fd)
 	{
 	/*

src/util.h

@@ -461,6 +461,10 @@ extern bool safe_write(int fd, const char* data, int len);
 // Same as safe_write(), but for pwrite().
 extern bool safe_pwrite(int fd, const unsigned char* data, size_t len, size_t offset);
 
+// Like fsync() but handles interrupted system calls by retrying and
+// aborts on unrecoverable errors.
+extern bool safe_fsync(int fd);
+
 // Wraps close(2) to emit error messages and abort on unrecoverable errors.
 extern void safe_close(int fd);