Merge pull request #4498 from soloestoy/aof-safe-write

Aof safe write -- fix the short write

src/aof.c

@@ -266,6 +266,27 @@ int startAppendOnly(void) {
     return C_OK;
 }
 
+ssize_t safe_write(int fd, const char *buf, size_t len) {
+    ssize_t nwritten = 0, totwritten = 0;
+
+    while(len) {
+        nwritten = write(fd, buf, len);
+
+        if (nwritten < 0) {
+            if (errno == EINTR) {
+                continue;
+            }
+            return totwritten ? totwritten : -1;
+        }
+
+        len -= nwritten;
+        buf += nwritten;
+        totwritten += nwritten;
+    }
+
+    return totwritten;
+}
+
 /* Write the append only file buffer on disk.
  *
  * Since we are required to write the AOF before replying to the client,
@@ -323,7 +344,7 @@ void flushAppendOnlyFile(int force) {
      * or alike */
 
     latencyStartMonitor(latency);
-    nwritten = write(server.aof_fd,server.aof_buf,sdslen(server.aof_buf));
+    nwritten = safe_write(server.aof_fd,server.aof_buf,sdslen(server.aof_buf));
     latencyEndMonitor(latency);
     /* We want to capture different events for delayed writes:
      * when the delay happens with a pending fsync, or with a saving child
@@ -342,7 +363,7 @@ void flushAppendOnlyFile(int force) {
     /* We performed the write so reset the postponed flush sentinel to zero. */
     server.aof_flush_postponed_start = 0;
 
-    if (nwritten != (signed)sdslen(server.aof_buf)) {
+    if (nwritten != (ssize_t)sdslen(server.aof_buf)) {
         static time_t last_write_error_log = 0;
         int can_log = 0;