[ECOS] JFFS2 fseek
Andrew Lunn
andrew@lunn.ch
Mon Mar 29 13:06:00 GMT 2004
> There looks to be a logic bug...
>
> Cyg_ErrNo err;
> off_t newpos=pos;
>
> err = cyg_stdio_lseek( my_device, &newpos, whence );
>
> if( err == ENOERR )
> {
> // Clean out the buffer. Flush output if any present,
> // and clear any input out of input buffer and any ungot
> // chars from unread buffer.
>
> err = flush_output_unlocked();
> io_buf.drain_buffer();
>
> It appears to be working out where the new position is and then
> seeking the file descriptor to the new position. It then flushed the
> stream write buffer and resets the input buffer.
>
> To me, this seems to be in the wrong order. It should flush the
> buffers before moving the file pointer. Attached is a totally untested
> patch. It might work. Please give it a try and let me know.
>
> Andrew
I've tested this patch now and it appears to work OK for the simple
case i've tested. I've added a new test to the ramfs code which
exercises fseek and ftell a little.
Andrew
-------------- next part --------------
Index: fs/ram/current//ChangeLog
===================================================================
RCS file: /cvs/ecos/ecos/packages/fs/ram/current/ChangeLog,v
retrieving revision 1.11
retrieving revision 1.12
diff -u -r1.11 -r1.12
--- fs/ram/current//ChangeLog 15 Mar 2004 17:17:10 -0000 1.11
+++ fs/ram/current//ChangeLog 29 Mar 2004 13:01:33 -0000 1.12
@@ -1,3 +1,8 @@
+2004-03-29 Andrew Lunn <andrew.lunn@ascom.ch>
+
+ * test/fseek1.c: Test the fseek/ftell functions
+ * cdl/ramfs.cdl: Added a fseek1 test to the build
+
2004-03-15 Sebastien Couret <sebastien.couret@elios-informatique.fr>
* src/ramfs.c (block_init): Fixed compiler warning.
Index: fs/ram/current//cdl/ramfs.cdl
===================================================================
RCS file: /cvs/ecos/ecos/packages/fs/ram/current/cdl/ramfs.cdl,v
retrieving revision 1.5
retrieving revision 1.6
diff -u -r1.5 -r1.6
--- fs/ram/current//cdl/ramfs.cdl 24 Feb 2003 14:22:18 -0000 1.5
+++ fs/ram/current//cdl/ramfs.cdl 29 Mar 2004 13:01:33 -0000 1.6
@@ -182,7 +182,7 @@
display "RAM FS tests"
flavor data
no_define
- calculated { "tests/fileio1.c" }
+ calculated { "tests/fileio1.c tests/fseek1.c" }
description "
This option specifies the set of tests for the RAM FS package."
}
Index: fs/ram/current//tests/fseek1.c
===================================================================
RCS file: fs/ram/current//tests/fseek1.c
diff -N fs/ram/current//tests/fseek1.c
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ fs/ram/current//tests/fseek1.c 29 Mar 2004 13:01:34 -0000 1.1
@@ -0,0 +1,173 @@
+//==========================================================================
+//
+// fseek1.c
+//
+// Test fseek on a filesystem
+//
+//==========================================================================
+//####ECOSGPLCOPYRIGHTBEGIN####
+// -------------------------------------------
+// This file is part of eCos, the Embedded Configurable Operating System.
+// Copyright (C) 2004 Andrew Lunn
+//
+// eCos is free software; you can redistribute it and/or modify it under
+// the terms of the GNU General Public License as published by the Free
+// Software Foundation; either version 2 or (at your option) any later version.
+//
+// eCos is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+// for more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with eCos; if not, write to the Free Software Foundation, Inc.,
+// 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+//
+// As a special exception, if other files instantiate templates or use macros
+// or inline functions from this file, or you compile this file and link it
+// with other works to produce a work based on this file, this file does not
+// by itself cause the resulting work to be covered by the GNU General Public
+// License. However the source code for this file must still be made available
+// in accordance with section (3) of the GNU General Public License.
+//
+// This exception does not invalidate any other reasons why a work based on
+// this file might be covered by the GNU General Public License.
+//
+// Alternative licenses for eCos may be arranged by contacting Red Hat, Inc.
+// at http://sources.redhat.com/ecos/ecos-license/
+// -------------------------------------------
+//####ECOSGPLCOPYRIGHTEND####
+//==========================================================================
+//#####DESCRIPTIONBEGIN####
+//
+// Author(s): asl
+// Contributors: asl
+// Date: 2004-03-29
+// Purpose: Test fseek on a filesystem
+// Description: This test uses the ramfs to check out the fseek
+// operation on a filesystem.
+//
+//
+//
+//
+//
+//
+//
+//####DESCRIPTIONEND####
+//
+//==========================================================================
+#include <stdio.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <string.h>
+
+#include <cyg/fileio/fileio.h>
+
+#include <cyg/infra/testcase.h>
+#include <cyg/infra/diag.h> // HAL polled output
+//==========================================================================
+
+#define SHOW_RESULT( _fn, _res ) \
+diag_printf("FAIL: " #_fn "() returned %d %s\n", _res, _res<0?strerror(errno):"");
+
+//==========================================================================
+
+char buf[1024];
+char buf1[1024];
+
+//==========================================================================
+// main
+
+int main( int argc, char **argv )
+{
+ int err;
+ FILE *stream;
+ long pos;
+ int i;
+
+ CYG_TEST_INIT();
+
+ // --------------------------------------------------------------
+
+ CYG_TEST_INFO("mount /");
+ err = mount( "", "/", "ramfs" );
+ if( err < 0 ) SHOW_RESULT( mount, err );
+
+ CYG_TEST_INFO("creating /fseek");
+ stream = fopen("/fseek","w+");
+ if (!stream) {
+ diag_printf("FAIL: fopen() returned NULL, %s\n", strerror(errno));
+ CYG_TEST_FINISH("done"); \
+ }
+
+ /* Write a buffer full of cyclic numbers */
+ for (i = 0; i < sizeof(buf); i++) {
+ buf[i] = i % 256;
+ }
+
+ CYG_TEST_INFO("writing test pattern");
+ err=fwrite(buf,sizeof(buf), 1, stream);
+ if ( err < 0 ) SHOW_RESULT( fwrite, err );
+
+ /* The current position should be the same size as the buffer */
+ pos = ftell(stream);
+
+ if (pos < 0) SHOW_RESULT( ftell, pos );
+ if (pos != sizeof(buf))
+ diag_printf("<FAIL>: ftell is not telling the truth.");
+
+ CYG_TEST_INFO("fseek()ing to beginning and writing");
+
+ /* Seek back to the beginning of the file */
+ err = fseek(stream, 0, SEEK_SET);
+ if ( err < 0 ) SHOW_RESULT( fwrite, err );
+
+ pos = ftell(stream);
+
+ if (pos < 0) SHOW_RESULT( ftell, pos );
+ if (pos != 0) CYG_TEST_FAIL("ftell is not telling the truth");
+
+ /* Write 4 zeros to the beginning of the file */
+ for (i = 0; i < 4; i++) {
+ buf[i] = 0;
+ }
+
+ err = fwrite(buf, 4, 1, stream);
+ if ( err < 0 ) SHOW_RESULT( fwrite, err );
+
+ /* Check the pointer is at 4 */
+ pos = ftell(stream);
+
+ if (pos < 0) SHOW_RESULT( ftell, pos );
+ if (pos != 4) CYG_TEST_FAIL("ftell is not telling the truth");
+
+ CYG_TEST_INFO("closing file");
+
+ /* Close the file, open it up again and read it back */
+ err = fclose(stream);
+ if (err != 0) SHOW_RESULT( fclose, err );
+
+ CYG_TEST_INFO("open file /fseek");
+ stream = fopen("/fseek", "r+");
+ if (!stream) {
+ diag_printf("<FAIL>: fopen() returned NULL, %s\n", strerror(errno));
+ }
+
+ err = fread(buf1,sizeof(buf1),1, stream);
+ if (err != 1) SHOW_RESULT( fread, err );
+
+ CYG_TEST_INFO("Comparing contents");
+ if (memcmp(buf, buf1, sizeof(buf1))) {
+ CYG_TEST_FAIL("File contents inconsistent");
+ }
+
+ err = fclose(stream);
+ if (err != 0) SHOW_RESULT( fclose, err );
+
+ CYG_TEST_INFO("umount /");
+ err = umount( "/" );
+ if( err < 0 ) SHOW_RESULT( umount, err );
+
+ CYG_TEST_PASS_FINISH("fseek1");
+}
More information about the Ecos-patches
mailing list