From: David van Moolenbroek <david@minix3.org>
Date: Sun, 31 Aug 2014 17:12:45 +0000 (+0000)
Subject: VFS: convert EINTR to EAGAIN for nonblocking I/O
X-Git-Tag: v3.3.0~30
X-Git-Url: http://zhaoyanbai.com/repos/%22http:/www.isc.org/icons/zlib_tech.html?a=commitdiff_plain;h=refs%2Fchanges%2F01%2F2801%2F1;p=minix.git

VFS: convert EINTR to EAGAIN for nonblocking I/O

The conversion was never properly implemented for asynchronous
character drivers, and got lost during the removal of the
synchronous character protocol.

Change-Id: Ib858806859aa7a52d6b391d4c6c521a2be361fdd
---

diff --git a/minix/servers/vfs/device.c b/minix/servers/vfs/device.c
index 7d34c0479..9fed98ae1 100644
--- a/minix/servers/vfs/device.c
+++ b/minix/servers/vfs/device.c
@@ -751,7 +751,7 @@ static void cdev_generic_reply(message *m_ptr)
   struct fproc *rfp;
   struct worker_thread *wp;
   endpoint_t proc_e;
-  int slot;
+  int r, slot;
 
   proc_e = m_ptr->m_lchardriver_vfs_reply.id;
 
@@ -777,7 +777,13 @@ static void cdev_generic_reply(message *m_ptr)
 	 */
 	printf("VFS: proc %d not blocked on %d\n", proc_e, m_ptr->m_source);
   } else {
-	revive(proc_e, m_ptr->m_lchardriver_vfs_reply.status);
+	/* Some services (inet) use the same infrastructure for nonblocking
+	 * and cancelled requests, resulting in one of EINTR or EAGAIN when the
+	 * other is really the appropriate code.  Thus, cdev_cancel converts
+	 * EAGAIN into EINTR, and we convert EINTR into EAGAIN here.
+	 */
+	r = m_ptr->m_lchardriver_vfs_reply.status;
+	revive(proc_e, (r == EINTR) ? EAGAIN : r);
   }
 }