--- embedaddon/rsync/fileio.c	2016/11/01 09:54:32	1.1.1.3
+++ embedaddon/rsync/fileio.c	2021/03/17 00:32:36	1.1.1.4
@@ -3,7 +3,7 @@
  *
  * Copyright (C) 1998 Andrew Tridgell
  * Copyright (C) 2002 Martin Pool
- * Copyright (C) 2004-2015 Wayne Davison
+ * Copyright (C) 2004-2020 Wayne Davison
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -26,21 +26,27 @@
 #define ENODATA EAGAIN
 #endif
 
-/* We want all reads to be aligned on 1K boundries. */
-#define ALIGN_BOUNDRY 1024
+/* We want all reads to be aligned on 1K boundaries. */
+#define ALIGN_BOUNDARY 1024
 /* How far past the boundary is an offset? */
-#define ALIGNED_OVERSHOOT(oft) ((oft) & (ALIGN_BOUNDRY-1))
+#define ALIGNED_OVERSHOOT(oft) ((oft) & (ALIGN_BOUNDARY-1))
 /* Round up a length to the next boundary */
-#define ALIGNED_LENGTH(len) ((((len) - 1) | (ALIGN_BOUNDRY-1)) + 1)
+#define ALIGNED_LENGTH(len) ((((len) - 1) | (ALIGN_BOUNDARY-1)) + 1)
 
 extern int sparse_files;
+extern int sparse_files_block_size;
 
+OFF_T preallocated_len = 0;
+
 static OFF_T sparse_seek = 0;
+static OFF_T sparse_past_write = 0;
 
 int sparse_end(int f, OFF_T size)
 {
 	int ret;
 
+	sparse_past_write = 0;
+
 	if (!sparse_seek)
 		return 0;
 
@@ -63,8 +69,10 @@ int sparse_end(int f, OFF_T size)
 	return ret;
 }
 
-
-static int write_sparse(int f, char *buf, int len)
+/* Note that the offset is just the caller letting us know where
+ * the current file position is in the file. The use_seek arg tells
+ * us that we should seek over matching data instead of writing it. */
+static int write_sparse(int f, int use_seek, OFF_T offset, const char *buf, int len)
 {
 	int l1 = 0, l2 = 0;
 	int ret;
@@ -77,10 +85,25 @@ static int write_sparse(int f, char *buf, int len)
 	if (l1 == len)
 		return len;
 
-	if (sparse_seek)
-		do_lseek(f, sparse_seek, SEEK_CUR);
+	if (sparse_seek) {
+		if (sparse_past_write >= preallocated_len) {
+			if (do_lseek(f, sparse_seek, SEEK_CUR) < 0)
+				return -1;
+		} else if (do_punch_hole(f, sparse_past_write, sparse_seek) < 0) {
+			sparse_seek = 0;
+			return -1;
+		}
+	}
 	sparse_seek = l2;
+	sparse_past_write = offset + len - l2;
 
+	if (use_seek) {
+		/* The in-place data already matches. */
+		if (do_lseek(f, len - (l1+l2), SEEK_CUR) < 0)
+			return -1;
+		return len;
+	}
+
 	while ((ret = write(f, buf + l1, len - (l1+l2))) <= 0) {
 		if (ret < 0 && errno == EINTR)
 			continue;
@@ -96,7 +119,6 @@ static int write_sparse(int f, char *buf, int len)
 	return len;
 }
 
-
 static char *wf_writeBuf;
 static size_t wf_writeBufSize;
 static size_t wf_writeBufCnt;
@@ -118,27 +140,24 @@ int flush_write_file(int f)
 	return ret;
 }
 
-
-/*
- * write_file does not allow incomplete writes.  It loops internally
- * until len bytes are written or errno is set.
- */
-int write_file(int f, char *buf, int len)
+/* write_file does not allow incomplete writes.  It loops internally
+ * until len bytes are written or errno is set.  Note that use_seek and
+ * offset are only used in sparse processing (see write_sparse()). */
+int write_file(int f, int use_seek, OFF_T offset, const char *buf, int len)
 {
 	int ret = 0;
 
 	while (len > 0) {
 		int r1;
 		if (sparse_files > 0) {
-			int len1 = MIN(len, SPARSE_WRITE_SIZE);
-			r1 = write_sparse(f, buf, len1);
+			int len1 = MIN(len, sparse_files_block_size);
+			r1 = write_sparse(f, use_seek, offset, buf, len1);
+			offset += r1;
 		} else {
 			if (!wf_writeBuf) {
 				wf_writeBufSize = WRITE_SIZE * 8;
 				wf_writeBufCnt  = 0;
 				wf_writeBuf = new_array(char, wf_writeBufSize);
-				if (!wf_writeBuf)
-					out_of_memory("write_file");
 			}
 			r1 = (int)MIN((size_t)len, wf_writeBufSize - wf_writeBufCnt);
 			if (r1) {
@@ -164,7 +183,31 @@ int write_file(int f, char *buf, int len)
 	return ret;
 }
 
+/* An in-place update found identical data at an identical location. We either
+ * just seek past it, or (for an in-place sparse update), we give the data to
+ * the sparse processor with the use_seek flag set. */
+int skip_matched(int fd, OFF_T offset, const char *buf, int len)
+{
+	OFF_T pos;
 
+	if (sparse_files > 0) {
+		if (write_file(fd, 1, offset, buf, len) != len)
+			return -1;
+		return 0;
+	}
+
+	if (flush_write_file(fd) < 0)
+		return -1;
+
+	if ((pos = do_lseek(fd, len, SEEK_CUR)) != offset + len) {
+		rsyserr(FERROR_XFER, errno, "lseek returned %s, not %s",
+			big_num(pos), big_num(offset));
+		return -1;
+	}
+
+	return 0;
+}
+
 /* This provides functionality somewhat similar to mmap() but using read().
  * It gives sliding window access to a file.  mmap() is not used because of
  * the possibility of another program (such as a mailer) truncating the
@@ -173,8 +216,7 @@ struct map_struct *map_file(int fd, OFF_T len, int32 r
 {
 	struct map_struct *map;
 
-	if (!(map = new0(struct map_struct)))
-		out_of_memory("map_file");
+	map = new0(struct map_struct);
 
 	if (blk_size && (read_size % blk_size))
 		read_size += blk_size - (read_size % blk_size);
@@ -217,8 +259,6 @@ char *map_ptr(struct map_struct *map, OFF_T offset, in
 	/* make sure we have allocated enough memory for the window */
 	if (window_size > map->p_size) {
 		map->p = realloc_array(map->p, char, window_size);
-		if (!map->p)
-			out_of_memory("map_ptr");
 		map->p_size = window_size;
 	}
 
@@ -271,7 +311,6 @@ char *map_ptr(struct map_struct *map, OFF_T offset, in
 	return map->p + align_fudge;
 }
 
-
 int unmap_file(struct map_struct *map)
 {
 	int	ret;
@@ -281,7 +320,9 @@ int unmap_file(struct map_struct *map)
 		map->p = NULL;
 	}
 	ret = map->status;
-	memset(map, 0, sizeof map[0]);
+#if 0 /* I don't think we really need this. */
+	force_memzero(map, sizeof map[0]);
+#endif
 	free(map);
 
 	return ret;