$NetBSD: patch-libntfs-3g_mft.c,v 1.1 2023/09/08 10:23:07 vins Exp $

Rip off mkntfs_get_page_size() from mkntfs.c, to avoid
a build error on archs where PAGE_SIZE is unusable.
From OpenBSD ports/sysutils/ntfs-3g.

--- libntfs-3g/mft.c.orig	2022-10-20 15:33:44.000000000 +0000
+++ libntfs-3g/mft.c
@@ -27,6 +27,9 @@
 #include "config.h"
 #endif
 
+#ifdef  HAVE_UNISTD_H
+#include <unistd.h>
+#endif
 #ifdef HAVE_STDLIB_H
 #include <stdlib.h>
 #endif
@@ -522,9 +525,28 @@ static int ntfs_is_mft(ntfs_inode *ni)
 	return 0;
 }
 
-#ifndef PAGE_SIZE
-#define PAGE_SIZE 4096
+/**
+ * mkntfs_get_page_size - detect the system's memory page size.
+ */
+static long mkntfs_get_page_size(void)
+{
+	long page_size;
+#ifdef _SC_PAGESIZE
+	page_size = sysconf(_SC_PAGESIZE);
+	if (page_size < 0)
 #endif
+#ifdef _SC_PAGE_SIZE
+		page_size = sysconf(_SC_PAGE_SIZE);
+	if (page_size < 0)
+#endif
+	{
+		ntfs_log_warning("Failed to determine system page size.  "
+				"Assuming safe default of 4096 bytes.\n");
+		return 4096;
+	}
+	ntfs_log_debug("System page size is %li bytes.\n", page_size);
+	return page_size;
+}
 
 #define RESERVED_MFT_RECORDS   64
 
@@ -550,6 +572,7 @@ static int ntfs_mft_bitmap_find_free_rec
 	s64 pass_end, ll, data_pos, pass_start, ofs, bit;
 	ntfs_attr *mftbmp_na;
 	u8 *buf, *byte;
+	long page_size;
 	unsigned int size;
 	u8 pass, b;
 	int ret = -1;
@@ -561,7 +584,8 @@ static int ntfs_mft_bitmap_find_free_rec
 	 * Set the end of the pass making sure we do not overflow the mft
 	 * bitmap.
 	 */
-	size = PAGE_SIZE;
+	page_size = mkntfs_get_page_size();
+	size = page_size;
 	pass_end = vol->mft_na->allocated_size >> vol->mft_record_size_bits;
 	ll = mftbmp_na->initialized_size << 3;
 	if (pass_end > ll)
@@ -587,7 +611,7 @@ static int ntfs_mft_bitmap_find_free_rec
 		pass = 2;
 	}
 	pass_start = data_pos;
-	buf = ntfs_malloc(PAGE_SIZE);
+	buf = ntfs_malloc(page_size);
 	if (!buf)
 		goto leave;
 	
@@ -600,7 +624,7 @@ static int ntfs_mft_bitmap_find_free_rec
 	b = 0;
 #endif
 	/* Loop until a free mft record is found. */
-	for (; pass <= 2; size = PAGE_SIZE) {
+	for (; pass <= 2; size = page_size) {
 		/* Cap size to pass_end. */
 		ofs = data_pos >> 3;
 		ll = ((pass_end + 7) >> 3) - ofs;