X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/2a189350f27d092fd05e85d4a08b941a26f13718..28b519c93b6db30b6520d46f8cd65160213fddd2:/util.c

diff --git a/util.c b/util.c
index a53ea291..3f611d15 100644
--- a/util.c
+++ b/util.c
@@ -30,6 +30,7 @@ extern int modify_window;
 extern int relative_paths;
 extern int preserve_times;
 extern int preserve_xattrs;
+extern int preallocate_files;
 extern char *module_dir;
 extern unsigned int module_dirlen;
 extern char *partial_dir;
@@ -315,6 +316,9 @@ int copy_file(const char *source, const char *dest, int ofd, mode_t mode)
 	int ifd;
 	char buf[1024 * 8];
 	int len;   /* Number of bytes read into `buf'. */
+#ifdef PREALLOCATE_NEEDS_TRUNCATE
+	OFF_T preallocated_len = 0, offset = 0;
+#endif
 
 	if ((ifd = do_open(source, O_RDONLY, 0)) < 0) {
 		int save_errno = errno;
@@ -345,6 +349,25 @@ int copy_file(const char *source, const char *dest, int ofd, mode_t mode)
 		}
 	}
 
+#ifdef SUPPORT_PREALLOCATION
+	if (preallocate_files) {
+		STRUCT_STAT srcst;
+
+		/* Try to preallocate enough space for file's eventual length.  Can
+		 * reduce fragmentation on filesystems like ext4, xfs, and NTFS. */
+		if (do_fstat(ifd, &srcst) < 0)
+			rsyserr(FWARNING, errno, "fstat %s", full_fname(source));
+		else if (srcst.st_size > 0) {
+			if (do_fallocate(ofd, 0, srcst.st_size) == 0) {
+#ifdef PREALLOCATE_NEEDS_TRUNCATE
+				preallocated_len = srcst.st_size;
+#endif
+			} else
+				rsyserr(FWARNING, errno, "do_fallocate %s", full_fname(dest));
+		}
+	}
+#endif
+
 	while ((len = safe_read(ifd, buf, sizeof buf)) > 0) {
 		if (full_write(ofd, buf, len) < 0) {
 			int save_errno = errno;
@@ -354,6 +377,9 @@ int copy_file(const char *source, const char *dest, int ofd, mode_t mode)
 			errno = save_errno;
 			return -1;
 		}
+#ifdef PREALLOCATE_NEEDS_TRUNCATE
+		offset += len;
+#endif
 	}
 
 	if (len < 0) {
@@ -370,6 +396,16 @@ int copy_file(const char *source, const char *dest, int ofd, mode_t mode)
 			full_fname(source));
 	}
 
+#ifdef PREALLOCATE_NEEDS_TRUNCATE
+	/* Source file might have shrunk since we fstatted it.
+	 * Cut off any extra preallocated zeros from dest file. */
+	if (offset < preallocated_len && do_ftruncate(ofd, offset) < 0) {
+		/* If we fail to truncate, the dest file may be wrong, so we
+		 * must trigger the "partial transfer" error. */
+		rsyserr(FERROR_XFER, errno, "ftruncate %s", full_fname(dest));
+	}
+#endif
+
 	if (close(ofd) < 0) {
 		int save_errno = errno;
 		rsyserr(FERROR_XFER, errno, "close failed on %s",