Do not make io_select return errors on unsupported READ/WRITE mode

The descriptor is valid, it is just the mode which is not available.

* console-client/kbd-repeat.c (repeater_select): Drop SELECT_URG flag from
`type'.  Return 0 instead of EINVAL if `type' contains SELECT_WRITE.
* console-client/pc-mouse (repeater_select): Likewise.
* trans/mtab.c (trivfs_S_io_select): Return 0 instead of EBADF when the
openmodes do not match the requested modes in `type'.
* trans/new-fifo.c (io_select_common): Likewise.
* trans/fifo.c (io_select_common): Likewise.
* trans/null.c (trivfs_S_io_select): Likewise.
* trans/streamio.c (io_select_common): Likewise.

7 files changed, 13 insertions, 23 deletions

diff --git a/console-client/kbd-repeat.c b/console-client/kbd-repeat.c
index d3a39d07..8d8c9ee8 100644
--- a/console-client/kbd-repeat.c
+++ b/console-client/kbd-repeat.c
@@ -94,8 +94,11 @@ repeater_select (struct protid *cred, mach_port_t reply,
   if (!cred)
     return EOPNOTSUPP;
 
+  *type &= ~SELECT_URG;
+
   if (*type & ~SELECT_READ)
-    return EINVAL;
+    /* Error immediately available...  */
+    return 0;
 
   if (*type == 0)
     return 0;
diff --git a/console-client/pc-mouse.c b/console-client/pc-mouse.c
index abdb602b..40a569d0 100644
--- a/console-client/pc-mouse.c
+++ b/console-client/pc-mouse.c
@@ -118,8 +118,11 @@ repeater_select (struct protid *cred, mach_port_t reply,
   if (!cred)
     return EOPNOTSUPP;
 
+  *type &= ~SELECT_URG;
+
   if (*type & ~SELECT_READ)
-    return EINVAL;
+    /* Error immediately available...  */
+    return 0;
 
   if (*type == 0)
     return 0;
diff --git a/trans/fifo.c b/trans/fifo.c
index f52baba9..ac31f495 100644
--- a/trans/fifo.c
+++ b/trans/fifo.c
@@ -436,7 +436,6 @@ io_select_common (struct trivfs_protid *cred,
 	}
       else
 	{
-	  err = EBADF;
 	  ready |= SELECT_READ;	/* Error immediately available...  */
 	}
       if (err)
@@ -458,7 +457,6 @@ io_select_common (struct trivfs_protid *cred,
 	}
       else
 	{
-	  err = EBADF;
 	  ready |= SELECT_WRITE;	/* Error immediately available...  */
 	}
     }
diff --git a/trans/mtab.c b/trans/mtab.c
index e0fcb468..c03749cc 100644
--- a/trans/mtab.c
+++ b/trans/mtab.c
@@ -843,10 +843,6 @@ trivfs_S_io_select (struct trivfs_protid *cred,
   if (!cred)
     return EOPNOTSUPP;
 
-  if (((*type & SELECT_READ) && !(cred->po->openmodes & O_READ))
-      || ((*type & SELECT_WRITE) && !(cred->po->openmodes & O_WRITE)))
-    return EBADF;
-
   *type &= ~SELECT_URG;
   return 0;
 }
diff --git a/trans/new-fifo.c b/trans/new-fifo.c
index 0ceb8422..f11cecae 100644
--- a/trans/new-fifo.c
+++ b/trans/new-fifo.c
@@ -623,7 +623,6 @@ io_select_common (struct trivfs_protid *cred,
 	}
       else
 	{
-	  err = EBADF;
 	  ready |= SELECT_READ;	/* Error immediately available...  */
 	}
       if (err)
@@ -645,7 +644,6 @@ io_select_common (struct trivfs_protid *cred,
 	}
       else
 	{
-	  err = EBADF;
 	  ready |= SELECT_WRITE;	/* Error immediately available...  */
 	}
     }
diff --git a/trans/null.c b/trans/null.c
index bd082dc8..92717ed8 100644
--- a/trans/null.c
+++ b/trans/null.c
@@ -204,11 +204,7 @@ trivfs_S_io_select (struct trivfs_protid *cred,
 {
   if (!cred)
     return EOPNOTSUPP;
-  else if (((*type & SELECT_READ) && !(cred->po->openmodes & O_READ))
-	   || ((*type & SELECT_WRITE) && !(cred->po->openmodes & O_WRITE)))
-    return EBADF;
-  else
-    *type &= ~SELECT_URG;
+  *type &= ~SELECT_URG;
   return 0;
 }
 
diff --git a/trans/streamio.c b/trans/streamio.c
index a80975f3..5539c8ea 100644
--- a/trans/streamio.c
+++ b/trans/streamio.c
@@ -560,9 +560,6 @@ io_select_common (struct trivfs_protid *cred,
   if (!cred)
     return EOPNOTSUPP;
 
-  if (!(cred->po->openmodes & O_WRITE) && (*type & SELECT_WRITE))
-    return EBADF;
-
   *type &= SELECT_READ | SELECT_WRITE;
 
   if (*type == 0)
@@ -575,11 +572,10 @@ io_select_common (struct trivfs_protid *cred,
       pthread_mutex_lock (&global_lock);
       if ((*type & SELECT_READ) && buffer_readable (input_buffer))
 	available |= SELECT_READ;
-      if (output_buffer)
-	{
-	  if ((*type & SELECT_WRITE) && buffer_writable (output_buffer))
-	    available |= SELECT_WRITE;
-	}
+      if ((*type & SELECT_WRITE) &&
+	  (!(cred->po->openmodes & O_WRITE) ||
+	    (buffer_writable && buffer_writable (output_buffer))))
+	available |= SELECT_WRITE;
 
       if (available)
 	{