Enhance io_submit() decoding

strace didn't decode important fields in the iocb passed to io_submit.
This patch changes the code to dump them all.  Also it prefixes the fields
with names to make it easier to read.

* desc.c (iocb_cmd_lookup, print_common_flags): New functions.
(sys_io_submit): New iocb decoder.

diff --git a/desc.c b/desc.c
index 293bfa42047cff452c01f886f7a110ce8ad3067a..f9100c46490077287a75faaf291cb273afe8815e 100644 (file)
--- a/desc.c
+++ b/desc.c
@@ -815,6 +815,51 @@ sys_io_destroy(struct tcb *tcp)
        return 0;
 }
 
+enum iocb_sub {
+       SUB_NONE, SUB_COMMON, SUB_POLL, SUB_VECTOR
+};
+
+static const char *
+iocb_cmd_lookup(unsigned cmd, enum iocb_sub *sub)
+{
+       static char buf[64];
+       static struct {
+               const char *name;
+               enum iocb_sub sub;
+       } cmds[] = {
+               { "pread", SUB_COMMON },
+               { "pwrite", SUB_COMMON },
+               { "fsync", SUB_NONE },
+               { "fdsync", SUB_NONE },
+               { "op4", SUB_NONE },
+               { "poll", SUB_POLL },
+               { "noop", SUB_NONE },
+               { "preadv", SUB_VECTOR },
+               { "pwritev", SUB_VECTOR },
+       };
+
+       if (cmd < ARRAY_SIZE(cmds)) {
+               *sub = cmds[cmd].sub;
+               return cmds[cmd].name;
+       }
+       *sub = SUB_NONE;
+       snprintf(buf, sizeof(buf), "%u /* SUB_??? */", cmd);
+       return buf;
+}
+
+/* Not defined in libaio.h */
+#ifndef IOCB_RESFD
+# define IOCB_RESFD (1 << 0)
+#endif
+
+static void
+print_common_flags(struct iocb *iocb)
+{
+       if (iocb->u.c.flags & IOCB_RESFD)
+               tprintf("resfd=%d, ", iocb->u.c.resfd);
+       if (iocb->u.c.flags & ~IOCB_RESFD)
+               tprintf("flags=%x, ", iocb->u.c.flags);
+}
 int
 sys_io_submit(struct tcb *tcp)
 {
@@ -831,6 +876,7 @@ sys_io_submit(struct tcb *tcp)
                        struct iocb *iocbp, **iocbs = (void *)tcp->u_arg[2];
 
                        for (i = 0; i < nr; i++, iocbs++) {
+                               enum iocb_sub sub;
                                struct iocb iocb;
                                if (i == 0)
                                        tprintf("{");
@@ -842,15 +888,49 @@ sys_io_submit(struct tcb *tcp)
                                        tprintf("{...}");
                                        continue;
                                }
-                               tprintf("{%p, %u, %hu, %hu, %d}",
-                                       iocb.data, iocb.key,
-                                       iocb.aio_lio_opcode,
-                                       iocb.aio_reqprio, iocb.aio_fildes);
+                               tprintf("{");
+                               if (iocb.data)
+                                       tprintf("data:%p, ", iocb.data);
+                               if (iocb.key)
+                                       tprintf("key:%u, ", iocb.key);
+                               tprintf("%s, ", iocb_cmd_lookup(iocb.aio_lio_opcode, &sub));
+                               if (iocb.aio_reqprio)
+                                       tprintf("reqprio:%d, ", iocb.aio_reqprio);
+                               tprintf("filedes:%d", iocb.aio_fildes);
+                               switch (sub) {
+                               case SUB_COMMON:
+                                       if (iocb.aio_lio_opcode == IO_CMD_PWRITE) {
+                                               tprintf(", str:");
+                                               printstr(tcp, (unsigned long)iocb.u.c.buf,
+                                                        iocb.u.c.nbytes);
+                                       } else {
+                                               tprintf(", buf:%p", iocb.u.c.buf);
+                                       }
+                                       tprintf(", nbytes:%lu, offset:%llx",
+                                               iocb.u.c.nbytes,
+                                               iocb.u.c.offset);
+                                       print_common_flags(&iocb);
+                                       break;
+                               case SUB_VECTOR:
+                                       tprintf(", %llx, ", iocb.u.v.offset);
+                                       print_common_flags(&iocb);
+                                       tprint_iov(tcp, iocb.u.v.nr,
+                                                  (unsigned long)iocb.u.v.vec,
+                                                  iocb.aio_lio_opcode == IO_CMD_PWRITEV);
+                                       break;
+                               case SUB_POLL:
+                                       tprintf(", %x", iocb.u.poll.events);
+                                       break;
+                               case SUB_NONE:
+                                       break;
+                               }
+                               tprintf("}");
                        }
                        if (i)
                                tprintf("}");
 #else
-                       tprintf("{...}");
+#warning "libaio-devel is not available => no io_submit decoding"
+                       tprintf("%#lx", tcp->u_arg[2]);
 #endif
                }
        }