Some `--write-device` fixes.

4 files changed, 24 insertions, 14 deletions

diff --git a/NEWS.md b/NEWS.md
index f95c6867..6dfed8d0 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -87,6 +87,12 @@
    per-file compression skipping has apparently never worked, so it is now
    documented as being ineffective.
 
+ - Fixed a truncate error when a `--write-devices` copy wrote a file onto a
+   device that was shorter than the device.
+
+ - Made `--write-devices` support both `--checksum` and `--no-whole-file` when
+   copying to a device.
+
  - Improved how the [`--stop-at`](rsync.1#opt), [`--stop-after`](rsync.1#opt),
    and (the deprecated) [`--time-limit`](rsync.1#opt) options check to see if
    the allowed time is over, which should make rsync exit more consistently.
diff --git a/generator.c b/generator.c
index 454fd19f..278e2a6f 100644
--- a/generator.c
+++ b/generator.c
@@ -35,11 +35,11 @@ extern int inc_recurse;
 extern int relative_paths;
 extern int implied_dirs;
 extern int keep_dirlinks;
+extern int write_devices;
 extern int preserve_acls;
 extern int preserve_xattrs;
 extern int preserve_links;
 extern int preserve_devices;
-extern int write_devices;
 extern int preserve_specials;
 extern int preserve_hard_links;
 extern int preserve_executability;
@@ -1793,6 +1793,12 @@ static void recv_generator(char *fname, struct file_struct *file, int ndx,
 		goto cleanup;
 	}
 
+	if (write_devices && IS_DEVICE(sx.st.st_mode) && sx.st.st_size == 0) {
+		/* This early open into fd skips the regular open below. */
+		if ((fd = do_open(fnamecmp, O_RDONLY, 0)) >= 0)
+			real_sx.st.st_size = sx.st.st_size = get_device_size(fd, fnamecmp);
+	}
+
 	if (fnamecmp_type <= FNAMECMP_BASIS_DIR_HIGH)
 		;
 	else if (fnamecmp_type >= FNAMECMP_FUZZY)
@@ -1858,7 +1864,7 @@ static void recv_generator(char *fname, struct file_struct *file, int ndx,
 	}
 
 	/* open the file */
-	if ((fd = do_open(fnamecmp, O_RDONLY, 0)) < 0) {
+	if (fd < 0 && (fd = do_open(fnamecmp, O_RDONLY, 0)) < 0) {
 		rsyserr(FERROR, errno, "failed to open %s, continuing",
 			full_fname(fnamecmp));
 	  pretend_missing:
@@ -1875,11 +1881,9 @@ static void recv_generator(char *fname, struct file_struct *file, int ndx,
 
 	if (inplace && make_backups > 0 && fnamecmp_type == FNAMECMP_FNAME) {
 		if (!(backupptr = get_backup_name(fname))) {
-			close(fd);
 			goto cleanup;
 		}
 		if (!(back_file = make_file(fname, NULL, NULL, 0, NO_FILTERS))) {
-			close(fd);
 			goto pretend_missing;
 		}
 		if (robust_unlink(backupptr) && errno != ENOENT) {
@@ -1887,14 +1891,12 @@ static void recv_generator(char *fname, struct file_struct *file, int ndx,
 				full_fname(backupptr));
 			unmake_file(back_file);
 			back_file = NULL;
-			close(fd);
 			goto cleanup;
 		}
 		if ((f_copy = do_open(backupptr, O_WRONLY | O_CREAT | O_TRUNC | O_EXCL, 0600)) < 0) {
 			rsyserr(FERROR_XFER, errno, "open %s", full_fname(backupptr));
 			unmake_file(back_file);
 			back_file = NULL;
-			close(fd);
 			goto cleanup;
 		}
 		fnamecmp_type = FNAMECMP_BACKUP;
@@ -1945,7 +1947,6 @@ static void recv_generator(char *fname, struct file_struct *file, int ndx,
 		write_sum_head(f_out, NULL);
 	else if (sx.st.st_size <= 0) {
 		write_sum_head(f_out, NULL);
-		close(fd);
 	} else {
 		if (generate_and_send_sums(fd, sx.st.st_size, f_out, f_copy) < 0) {
 			rprintf(FWARNING,
@@ -1953,10 +1954,11 @@ static void recv_generator(char *fname, struct file_struct *file, int ndx,
 				fnamecmp);
 			write_sum_head(f_out, NULL);
 		}
-		close(fd);
 	}
 
   cleanup:
+	if (fd >= 0)
+		close(fd);
 	if (back_file) {
 		int save_preserve_xattrs = preserve_xattrs;
 		if (f_copy >= 0)
diff --git a/receiver.c b/receiver.c
index 90e1685b..b3a69da0 100644
--- a/receiver.c
+++ b/receiver.c
@@ -808,14 +808,16 @@ int recv_files(int f_in, int f_out, char *local_name)
 			continue;
 		}
 
-		if (fd1 != -1 && !(S_ISREG(st.st_mode) || (write_devices && IS_DEVICE(st.st_mode)))) {
+		if (write_devices && IS_DEVICE(st.st_mode)) {
+			if (fd1 != -1 && st.st_size == 0)
+				st.st_size = get_device_size(fd1, fname);
+			/* Mark the file entry as a device so that we don't try to truncate it later on. */
+			file->mode = S_IFBLK | (file->mode & ACCESSPERMS);
+		} else if (fd1 != -1 && !(S_ISREG(st.st_mode))) {
 			close(fd1);
 			fd1 = -1;
 		}
 
-		if (fd1 != -1 && IS_DEVICE(st.st_mode) && st.st_size == 0)
-			st.st_size = get_device_size(fd1, fname);
-
 		/* If we're not preserving permissions, change the file-list's
 		 * mode based on the local permissions and some heuristics. */
 		if (!preserve_perms) {
diff --git a/rsync.1.md b/rsync.1.md
index 06024916..ca0ed7f7 100644
--- a/rsync.1.md
+++ b/rsync.1.md
@@ -1481,9 +1481,9 @@ your home directory (remove the '=' for that).
     This option implies the [`--inplace`](#opt) option.
 
     Be careful using this, as you should know what devices are present on the
-    receiving side of the transfer, especially if running rsync as root.
+    receiving side of the transfer, especially when running rsync as root.
 
-    This option is refused by an rsync daemon.
+    This option is refused by default by an rsync daemon.
 
 0.  `--times`, `-t`