From 53da07e436df21f078de665d90442ee5c7166ab7 Mon Sep 17 00:00:00 2001
From: Sebastian Huber <sebastian.huber@embedded-brains.de>
Date: Mon, 14 May 2012 15:21:30 +0200
Subject: Filesystem: PR1255: Move offset update to handlers

It is now the responsibility of the read() and write() handler to update
the offset field of the IO descriptor (rtems_libio_t).  This change
makes it possible to protect the IO descriptor from concurrent access by
per file locks.
---
 cpukit/libcsupport/src/read.c            | 8 +-------
 cpukit/libcsupport/src/readv.c           | 1 -
 cpukit/libcsupport/src/sup_fs_deviceio.c | 4 ++++
 cpukit/libcsupport/src/write.c           | 8 +-------
 cpukit/libcsupport/src/writev.c          | 1 -
 5 files changed, 6 insertions(+), 16 deletions(-)

(limited to 'cpukit/libcsupport/src')

diff --git a/cpukit/libcsupport/src/read.c b/cpukit/libcsupport/src/read.c
index 759133b0cb..ee10166dc8 100644
--- a/cpukit/libcsupport/src/read.c
+++ b/cpukit/libcsupport/src/read.c
@@ -22,7 +22,6 @@ ssize_t read(
   size_t      count
 )
 {
-  ssize_t      rc;
   rtems_libio_t *iop;
 
   rtems_libio_check_fd( fd );
@@ -35,12 +34,7 @@ ssize_t read(
   /*
    *  Now process the read().
    */
-  rc = (*iop->pathinfo.handlers->read_h)( iop, buffer, count );
-
-  if ( rc > 0 )
-    iop->offset += rc;
-
-  return rc;
+  return (*iop->pathinfo.handlers->read_h)( iop, buffer, count );
 }
 
 /*
diff --git a/cpukit/libcsupport/src/readv.c b/cpukit/libcsupport/src/readv.c
index b23abd0b82..4e540d5da4 100644
--- a/cpukit/libcsupport/src/readv.c
+++ b/cpukit/libcsupport/src/readv.c
@@ -106,7 +106,6 @@ ssize_t readv(
       return -1;
 
     if ( bytes > 0 ) {
-      iop->offset += bytes;
       total       += bytes;
     }
 
diff --git a/cpukit/libcsupport/src/sup_fs_deviceio.c b/cpukit/libcsupport/src/sup_fs_deviceio.c
index aeff60ea83..74f92cb44c 100644
--- a/cpukit/libcsupport/src/sup_fs_deviceio.c
+++ b/cpukit/libcsupport/src/sup_fs_deviceio.c
@@ -72,6 +72,8 @@ ssize_t rtems_deviceio_read(
 
   status = rtems_io_read( major, minor, &args );
   if ( status == RTEMS_SUCCESSFUL ) {
+    iop->offset += args.bytes_moved;
+
     return (ssize_t) args.bytes_moved;
   } else {
     return rtems_deviceio_errno( status );
@@ -98,6 +100,8 @@ ssize_t rtems_deviceio_write(
 
   status = rtems_io_write( major, minor, &args );
   if ( status == RTEMS_SUCCESSFUL ) {
+    iop->offset += args.bytes_moved;
+
     return (ssize_t) args.bytes_moved;
   } else {
     return rtems_deviceio_errno( status );
diff --git a/cpukit/libcsupport/src/write.c b/cpukit/libcsupport/src/write.c
index b74738845b..dc1255867d 100644
--- a/cpukit/libcsupport/src/write.c
+++ b/cpukit/libcsupport/src/write.c
@@ -29,7 +29,6 @@ ssize_t write(
   size_t      count
 )
 {
-  ssize_t  rc;
   rtems_libio_t     *iop;
 
   rtems_libio_check_fd( fd );
@@ -42,10 +41,5 @@ ssize_t write(
   /*
    *  Now process the write() request.
    */
-  rc = (*iop->pathinfo.handlers->write_h)( iop, buffer, count );
-
-  if ( rc > 0 )
-    iop->offset += rc;
-
-  return rc;
+  return (*iop->pathinfo.handlers->write_h)( iop, buffer, count );
 }
diff --git a/cpukit/libcsupport/src/writev.c b/cpukit/libcsupport/src/writev.c
index 8356c1ee66..47605a4cd9 100644
--- a/cpukit/libcsupport/src/writev.c
+++ b/cpukit/libcsupport/src/writev.c
@@ -113,7 +113,6 @@ ssize_t writev(
       return -1;
 
     if ( bytes > 0 ) {
-      iop->offset += bytes;
       total       += bytes;
     }
 
-- 
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