src/shared/util.h: import loop_write() from upstream

Signed-off-by: Anthony G. Basile <blueness@gentoo.org>

2 files changed, 39 insertions, 0 deletions

diff --git a/src/shared/util.c b/src/shared/util.c
index f726e0ee2b..88defdc4f2 100644
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -906,6 +906,44 @@ int loop_read_exact(int fd, void *buf, size_t nbytes, bool do_poll) {
         return 0;
 }
 
+int loop_write(int fd, const void *buf, size_t nbytes, bool do_poll) {
+        const uint8_t *p = buf;
+
+        assert(fd >= 0);
+        assert(buf);
+
+        errno = 0;
+
+        do {
+                ssize_t k;
+
+                k = write(fd, p, nbytes);
+                if (k < 0) {
+                        if (errno == EINTR)
+                                continue;
+
+                        if (errno == EAGAIN && do_poll) {
+                                /* We knowingly ignore any return value here,
+                                 * and expect that any error/EOF is reported
+                                 * via write() */
+
+                                fd_wait_for_event(fd, POLLOUT, USEC_INFINITY);
+                                continue;
+                        }
+
+                        return -errno;
+                }
+
+                if (nbytes > 0 && k == 0) /* Can't really happen */
+                        return -EIO;
+
+                p += k;
+                nbytes -= k;
+        } while (nbytes > 0);
+
+        return 0;
+}
+
 char* dirname_malloc(const char *path) {
         char *d, *dir, *dir2;
 
diff --git a/src/shared/util.h b/src/shared/util.h
index f6c8f75649..423210e2f0 100644
--- a/src/shared/util.h
+++ b/src/shared/util.h
@@ -221,6 +221,7 @@ int fopen_temporary(const char *path, FILE **_f, char **_temp_path);
 
 ssize_t loop_read(int fd, void *buf, size_t nbytes, bool do_poll);
 int loop_read_exact(int fd, void *buf, size_t nbytes, bool do_poll);
+int loop_write(int fd, const void *buf, size_t nbytes, bool do_poll);
 
 char* dirname_malloc(const char *path);