Bump to version 1.22.1

[platform/upstream/busybox.git] / libbb / copyfd.c

diff --git a/libbb/copyfd.c b/libbb/copyfd.c
index ed383ae..eda2747 100644 (file)
--- a/libbb/copyfd.c
+++ b/libbb/copyfd.c
@@ -4,30 +4,45 @@
  *
  * Copyright (C) 1999-2005 by Erik Andersen <andersen@codepoet.org>
  *
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  */
 
 #include "libbb.h"
 
-/* Used by NOFORK applets (e.g. cat) - must not use xmalloc */
-
+/* Used by NOFORK applets (e.g. cat) - must not use xmalloc.
+ * size < 0 means "ignore write errors", used by tar --to-command
+ * size = 0 means "copy till EOF"
+ */
 static off_t bb_full_fd_action(int src_fd, int dst_fd, off_t size)
 {
        int status = -1;
        off_t total = 0;
+       bool continue_on_write_error = 0;
 #if CONFIG_FEATURE_COPYBUF_KB <= 4
        char buffer[CONFIG_FEATURE_COPYBUF_KB * 1024];
        enum { buffer_size = sizeof(buffer) };
 #else
        char *buffer;
        int buffer_size;
+#endif
 
+       if (size < 0) {
+               size = -size;
+               continue_on_write_error = 1;
+       }
+
+#if CONFIG_FEATURE_COPYBUF_KB > 4
+       if (size > 0 && size <= 4 * 1024)
+               goto use_small_buf;
+       /* We want page-aligned buffer, just in case kernel is clever
+        * and can do page-aligned io more efficiently */
        buffer = mmap(NULL, CONFIG_FEATURE_COPYBUF_KB * 1024,
                        PROT_READ | PROT_WRITE,
                        MAP_PRIVATE | MAP_ANON,
                        /* ignored: */ -1, 0);
        buffer_size = CONFIG_FEATURE_COPYBUF_KB * 1024;
        if (buffer == MAP_FAILED) {
+ use_small_buf:
                buffer = alloca(4 * 1024);
                buffer_size = 4 * 1024;
        }
@@ -58,8 +73,11 @@ static off_t bb_full_fd_action(int src_fd, int dst_fd, off_t size)
                if (dst_fd >= 0) {
                        ssize_t wr = full_write(dst_fd, buffer, rd);
                        if (wr < rd) {
-                               bb_perror_msg(bb_msg_write_error);
-                               break;
+                               if (!continue_on_write_error) {
+                                       bb_perror_msg(bb_msg_write_error);
+                                       break;
+                               }
+                               dst_fd = -1;
                        }
                }
                total += rd;
@@ -83,7 +101,7 @@ static off_t bb_full_fd_action(int src_fd, int dst_fd, off_t size)
 
 
 #if 0
-void complain_copyfd_and_die(off_t sz)
+void FAST_FUNC complain_copyfd_and_die(off_t sz)
 {
        if (sz != -1)
                bb_error_msg_and_die("short read");
@@ -92,7 +110,7 @@ void complain_copyfd_and_die(off_t sz)
 }
 #endif
 
-off_t bb_copyfd_size(int fd1, int fd2, off_t size)
+off_t FAST_FUNC bb_copyfd_size(int fd1, int fd2, off_t size)
 {
        if (size) {
                return bb_full_fd_action(fd1, fd2, size);
@@ -100,10 +118,10 @@ off_t bb_copyfd_size(int fd1, int fd2, off_t size)
        return 0;
 }
 
-void bb_copyfd_exact_size(int fd1, int fd2, off_t size)
+void FAST_FUNC bb_copyfd_exact_size(int fd1, int fd2, off_t size)
 {
        off_t sz = bb_copyfd_size(fd1, fd2, size);
-       if (sz == size)
+       if (sz == (size >= 0 ? size : -size))
                return;
        if (sz != -1)
                bb_error_msg_and_die("short read");
@@ -111,7 +129,7 @@ void bb_copyfd_exact_size(int fd1, int fd2, off_t size)
        xfunc_die();
 }
 
-off_t bb_copyfd_eof(int fd1, int fd2)
+off_t FAST_FUNC bb_copyfd_eof(int fd1, int fd2)
 {
        return bb_full_fd_action(fd1, fd2, 0);
 }