r8746: replace opendir/readdir/telldir/seekdir/closedir on systems where they

are broken (apparently all BSD systems). This breakage leads to unlink
on files in an open directory causing a later seekdir to miss
files. The bug happens due to a block boundary bug in the BSD libc
implementation of these calls.

This replacement code also fixes a severe memory usage problem with
telldir that can cause closedir() to take an arbitrary amount of time.

I have reported the bug in readdir to Greg Lehey (a FreeBSD maintainer)
(This used to be commit e1bf7c4279fbc03a52497d24cea375e75059cba1)

1 files changed, 110 insertions, 0 deletions

diff --git a/source4/build/tests/os2_delete.c b/source4/build/tests/os2_delete.c
new file mode 100644
index 0000000000..dad27e8f2c
--- /dev/null
+++ b/source4/build/tests/os2_delete.c
@@ -0,0 +1,110 @@
+/*
+  test readdir/unlink pattern that OS/2 uses
+  tridge@samba.org July 2005
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <dirent.h>
+#include <errno.h>
+#include <string.h>
+#include <fcntl.h>
+#ifdef REPLACE_READDIR
+#include "lib/replace/repdir/repdir.h"
+#endif
+
+#define NUM_FILES 700
+#define READDIR_SIZE 100
+#define DELETE_SIZE 4
+
+#define TESTDIR "test.dir"
+
+#define FAILED() (fprintf(stderr, "Failed at %s:%d - %s\n", __FUNCTION__, __LINE__, strerror(errno)), exit(1), 1)
+
+#ifndef MIN
+#define MIN(a,b) ((a)<(b)?(a):(b))
+#endif
+
+static void cleanup(void)
+{
+	/* I'm a lazy bastard */
+	system("rm -rf " TESTDIR);
+	mkdir(TESTDIR, 0700) == 0 || FAILED();
+}
+
+static void create_files()
+{
+	int i;
+	for (i=0;i<NUM_FILES;i++) {
+		char fname[40];
+		sprintf(fname, TESTDIR "/test%u.txt", i);
+		close(open(fname, O_CREAT|O_RDWR, 0600)) == 0 || FAILED();
+	}
+}
+
+static int os2_delete(DIR *d)
+{
+	off_t offsets[READDIR_SIZE];
+	int i, j;
+	struct dirent *de;
+	char names[READDIR_SIZE][30];
+
+	/* scan, remembering offsets */
+	for (i=0, de=readdir(d); 
+	     de && i < READDIR_SIZE; 
+	     de=readdir(d), i++) {
+		offsets[i] = telldir(d);
+		strcpy(names[i], de->d_name);
+	}
+
+	if (i == 0) {
+		return 0;
+	}
+
+	/* delete the first few */
+	for (j=0; j<MIN(i, DELETE_SIZE); j++) {
+		char fname[40];
+		sprintf(fname, TESTDIR "/%s", names[j]);
+		unlink(fname) == 0 || FAILED();
+	}
+
+	/* seek to just after the deletion */
+	seekdir(d, offsets[j-1]);
+
+	/* return number deleted */
+	return j;
+}
+
+int main(void)
+{
+	int total_deleted = 0;
+	DIR *d;
+	struct dirent *de;
+
+	cleanup();
+	create_files();
+	
+	d = opendir(TESTDIR);
+
+	/* skip past . and .. */
+	de = readdir(d);
+	strcmp(de->d_name, ".") == 0 || FAILED();
+	de = readdir(d);
+	strcmp(de->d_name, "..") == 0 || FAILED();
+
+	while (1) {
+		int n = os2_delete(d);
+		if (n == 0) break;
+		total_deleted += n;
+	}
+	closedir(d);
+
+	printf("Deleted %d files of %d\n", total_deleted, NUM_FILES);
+
+	rmdir(TESTDIR) == 0 || FAILED();
+
+	return 0;
+}