VFS: start off cleanup of pipe2 IPC message

There is no reason to use a single message for nonoverlapping requests
and replies combined, and in fact splitting them out allows reuse of
messages and avoids various problems with field layouts.  Since the
upcoming socketpair(2) system call will be using the same reply as
pipe2(2), split up the single message used for the latter.  In order
to keep the used parts of messages at the front, start a transitional
phase to move the pipe(2) flags field to the front of its request.

Change-Id: If3f1c3d348ec7e27b7f5b7147ce1b9ef490dfab9

diff --git a/minix/include/minix/ipc.h b/minix/include/minix/ipc.h
index 00e25add8b4ac2a2fda80f3118601373a3a43c20..ac4e7e2a2040a30293f343a8526dc43749ec302c 100644 (file)
--- a/minix/include/minix/ipc.h
+++ b/minix/include/minix/ipc.h
@@ -760,9 +760,14 @@ typedef struct {
 _ASSERT_MSG_SIZE(mess_lc_vfs_path);
 
 typedef struct {
-       int fd0;
-       int fd1;
+       /*
+        * We are in the process of cleaning up this message, by moving the
+        * flags value from the third integer into the first.  Once enough time
+        * has passed, we can get rid of the second and third integer fields.
+        */
        int flags;
+       int _unused;
+       int oflags;
 
        uint8_t padding[44];
 } mess_lc_vfs_pipe2;
@@ -1949,6 +1954,14 @@ typedef struct {
 } mess_vfs_fs_utime;
 _ASSERT_MSG_SIZE(mess_vfs_fs_utime);
 
+typedef struct {
+       int fd0;
+       int fd1;
+
+       uint8_t padding[48];
+} mess_vfs_lc_fdpair;
+_ASSERT_MSG_SIZE(mess_vfs_lc_fdpair);
+
 typedef struct {
        off_t offset;
 
@@ -2262,6 +2275,7 @@ typedef struct noxfer_message {
                mess_vfs_fs_statvfs     m_vfs_fs_statvfs;
                mess_vfs_fs_unlink      m_vfs_fs_unlink;
                mess_vfs_fs_utime       m_vfs_fs_utime;
+               mess_vfs_lc_fdpair      m_vfs_lc_fdpair;
                mess_vfs_lc_lseek       m_vfs_lc_lseek;
                mess_vfs_lchardriver_cancel     m_vfs_lchardriver_cancel;
                mess_vfs_lchardriver_openclose  m_vfs_lchardriver_openclose;

diff --git a/minix/lib/libc/sys/pipe.c b/minix/lib/libc/sys/pipe.c
index 38e79664b82564f55636d25b08e2ea2524daaa9c..15dbf236ce31e7d513af5886f8f468d2a6d6f35f 100644 (file)
--- a/minix/lib/libc/sys/pipe.c
+++ b/minix/lib/libc/sys/pipe.c
@@ -16,10 +16,11 @@ pipe2(int fild[2], int flags)
 
        memset(&m, 0, sizeof(m));
        m.m_lc_vfs_pipe2.flags = flags;
+       m.m_lc_vfs_pipe2.oflags = flags;        /* backward compatibility */
 
        if (_syscall(VFS_PROC_NR, VFS_PIPE2, &m) < 0) return(-1);
-       fild[0] = m.m_lc_vfs_pipe2.fd0;
-       fild[1] = m.m_lc_vfs_pipe2.fd1;
+       fild[0] = m.m_vfs_lc_fdpair.fd0;
+       fild[1] = m.m_vfs_lc_fdpair.fd1;
        return(0);
 }
 

diff --git a/minix/servers/vfs/pipe.c b/minix/servers/vfs/pipe.c
index 2aee4ac5c7c87fb3b31b4e2f1078aeb8b133b8f0..795023fe1aa8840f7e1eff96cc1acca3020cdfb6 100644 (file)
--- a/minix/servers/vfs/pipe.c
+++ b/minix/servers/vfs/pipe.c
@@ -43,11 +43,12 @@ int do_pipe2(void)
   int fil_des[2];              /* reply goes here */
 
   flags = job_m_in.m_lc_vfs_pipe2.flags;
+  flags |= job_m_in.m_lc_vfs_pipe2.oflags;     /* backward compatibility */
 
   r = create_pipe(fil_des, flags);
   if (r == OK) {
-       job_m_out.m_lc_vfs_pipe2.fd0 = fil_des[0];
-       job_m_out.m_lc_vfs_pipe2.fd1 = fil_des[1];
+       job_m_out.m_vfs_lc_fdpair.fd0 = fil_des[0];
+       job_m_out.m_vfs_lc_fdpair.fd1 = fil_des[1];
   }
 
   return r;

diff --git a/minix/usr.bin/trace/service/vfs.c b/minix/usr.bin/trace/service/vfs.c
index c928f2e269ff6189a2ac8fe067919929b4911982..ed4791dfc166b01c5f32254a95978d152b98455a 100644 (file)
--- a/minix/usr.bin/trace/service/vfs.c
+++ b/minix/usr.bin/trace/service/vfs.c
@@ -678,8 +678,8 @@ vfs_pipe2_in(struct trace_proc * proc, const message * m_out,
 
        if (!failed) {
                put_open(proc, "fd", PF_NONAME, "[", ", ");
-               put_fd(proc, "rfd", m_in->m_lc_vfs_pipe2.fd0);
-               put_fd(proc, "wfd", m_in->m_lc_vfs_pipe2.fd1);
+               put_fd(proc, "rfd", m_in->m_vfs_lc_fdpair.fd0);
+               put_fd(proc, "wfd", m_in->m_vfs_lc_fdpair.fd1);
                put_close(proc, "]");
        } else
                put_field(proc, "fd", "&..");