From 4b1cd8c0ec87c64e077c281a362a7543a2fdf1eb Mon Sep 17 00:00:00 2001
From: Philip Homburg <philip@cs.vu.nl>
Date: Wed, 15 Aug 2007 12:53:52 +0000
Subject: [PATCH] Return EIO if a filedescriptor cannot be re-opened after a
 driver restart. Select now returns such a filedescriptor as ready (instead of
 EBADF). Reply before dev_up in FSSIGNON to avoid the problem that a DEV_OPEN
 request is received by a driver that expects a reply from the FSSIGNON.

---
 servers/vfs/device.c  |  8 +++++---
 servers/vfs/filedes.c |  7 +++++++
 servers/vfs/misc.c    |  4 ++++
 servers/vfs/read.c    |  3 ++-
 servers/vfs/select.c  | 14 +++++++++++---
 5 files changed, 29 insertions(+), 7 deletions(-)

diff --git a/servers/vfs/device.c b/servers/vfs/device.c
index be6933a3b..36b449b2d 100644
--- a/servers/vfs/device.c
+++ b/servers/vfs/device.c
@@ -807,10 +807,12 @@ printf("VFSdev_up: error sending new driver endpoint. FS_e: %d req_nr: %d\n",
 
         minor = ((vp->v_sdev >> MINOR) & BYTE);
 
-        printf("VFS: reopening special %d/%d..\n", maj, minor);
+        printf("vfs:dev_up: reopening special %d/%d..\n", maj, minor);
 
-        if((r = dev_open(vp->v_sdev, FS_PROC_NR,
-                        vp->v_mode & (R_BIT|W_BIT))) != OK) {
+	printf("vfs:dev_up: before dev_open\n");
+        r = dev_open(vp->v_sdev, FS_PROC_NR, vp->v_mode & (R_BIT|W_BIT));
+	printf("vfs:dev_up: after dev_open: result = %d\n", r);
+        if (r != OK) {
             int n;
             /* This function will set the fp_filp[]s of processes
              * holding that fp to NULL, but _not_ clear
diff --git a/servers/vfs/filedes.c b/servers/vfs/filedes.c
index 6e57d8f6c..f1fae581c 100644
--- a/servers/vfs/filedes.c
+++ b/servers/vfs/filedes.c
@@ -84,6 +84,13 @@ int fild;			/* file descriptor */
 
   err_code = EBADF;
   if (fild < 0 || fild >= OPEN_MAX ) return(NIL_FILP);
+  if (rfp->fp_filp[fild] == NIL_FILP && FD_ISSET(fild, &rfp->fp_filp_inuse))
+  {
+	printf("get_filp2: setting err_code to EIO for proc %d fd %d\n",
+		rfp->fp_endpoint, fild);
+	err_code = EIO;	/* The filedes is not there, but is not closed either.
+			 */
+  }
   return(rfp->fp_filp[fild]);	/* may also be NIL_FILP */
 }
 
diff --git a/servers/vfs/misc.c b/servers/vfs/misc.c
index 240fd03fb..5d24df96c 100644
--- a/servers/vfs/misc.c
+++ b/servers/vfs/misc.c
@@ -550,7 +550,11 @@ PUBLIC int do_svrctl()
 		 * to be up.
 		*/
 		if(fproc[proc_nr_n].fp_execced) {
+			/* Reply before calling dev_up */
+			printf("do_svrctl: replying before dev_up\n");
+			reply(who_e, r);
 			dev_up(major);
+			r= SUSPEND;
 		} else {
 			dmap[major].dmap_flags |= DMAP_BABY;
 		}
diff --git a/servers/vfs/read.c b/servers/vfs/read.c
index 46ee6c88d..d3660d6cf 100644
--- a/servers/vfs/read.c
+++ b/servers/vfs/read.c
@@ -71,7 +71,8 @@ int rw_flag;			/* READING or WRITING */
 
   if ((f = get_filp(m_in.fd)) == NIL_FILP)
   {
-  	printf("vfs:read_write: returning %d\n", err_code);
+  	printf("vfs:read_write: returning %d to endpoint %d\n",
+		err_code, who_e);
   	return(err_code);
   }
   if (((f->filp_mode) & (rw_flag == READING ? R_BIT : W_BIT)) == 0) {
diff --git a/servers/vfs/select.c b/servers/vfs/select.c
index 05fd10c79..710e3ed63 100644
--- a/servers/vfs/select.c
+++ b/servers/vfs/select.c
@@ -278,9 +278,17 @@ PUBLIC int do_select(void)
 	
 		if (!(orig_ops = ops = tab2ops(fd, &selecttab[s])))
 			continue;
-		if (!(filp = selecttab[s].filps[fd] = get_filp(fd))) {
-			select_cancel_all(&selecttab[s]);
-			return EBADF;
+		filp = selecttab[s].filps[fd] = get_filp(fd);
+		if (filp == NULL) {
+			if (err_code == EBADF) {
+				select_cancel_all(&selecttab[s]);
+				return EBADF;
+			}
+
+			/* File descriptor is 'ready' to return EIO */
+			printf("vfs:do_select: EIO after driver failure\n");
+			ops2tab(SEL_RD|SEL_WR|SEL_ERR, fd, &selecttab[s]);
+			continue;
 		}
 
 		for(t = 0; t < SEL_FDS; t++) {
-- 
2.44.0