file_copy: handle zero bytes copied by copy_file_range (bug 828844)
When copy_file_range copied zero bytes, fall back to sendfile,
so that we don't call copy_file_range in an infinite loop.
Bug: https://bugs.gentoo.org/828844
Tested-by: John Helmert III <ajak@gentoo.org>
Signed-off-by: Zac Medico <zmedico@gentoo.org>
diff --git a/src/portage_util_file_copy_reflink_linux.c b/src/portage_util_file_copy_reflink_linux.c
index c6affe5..b00b579 100644
--- a/src/portage_util_file_copy_reflink_linux.c
+++ b/src/portage_util_file_copy_reflink_linux.c
@@ -261,13 +261,14 @@
&offset_out,
len);
- if (copyfunc_ret < 0) {
+ if (copyfunc_ret <= 0) {
error = errno;
- if ((errno == EXDEV || errno == ENOSYS || errno == EOPNOTSUPP) &&
+ if ((errno == EXDEV || errno == ENOSYS || errno == EOPNOTSUPP || copyfunc_ret == 0) &&
copyfunc == cfr_wrapper) {
/* Use sendfile instead of copy_file_range for
* cross-device copies, or when the copy_file_range
- * syscall is not available (less than Linux 4.5).
+ * syscall is not available (less than Linux 4.5),
+ * or when copy_file_range copies zero bytes.
*/
error = 0;
copyfunc = sf_wrapper;
