From 255ae85b1ea2a42d0df32f3326e03f8201efc46b Mon Sep 17 00:00:00 2001
From: Evgeniy Ivanov <lolkaantimat@gmail.com>
Date: Fri, 15 Jul 2011 14:21:05 +0000
Subject: [PATCH] Fix time modification on truncate()

POSIX truncate specification says "Upon successful completion, if
the *file size is changed*, this function shall mark for update the
st_ctime and st_mtime fields of the file." This patch prevents
changing of the date fields when the size stays the same.
---
 servers/ext2/link.c | 2 ++
 servers/mfs/link.c  | 8 +++++---
 test/test16.c       | 9 +++++++++
 3 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/servers/ext2/link.c b/servers/ext2/link.c
index 2cf634b1b..4da39513d 100644
--- a/servers/ext2/link.c
+++ b/servers/ext2/link.c
@@ -563,6 +563,8 @@ off_t newsize;			/* inode must become this size */
 	return(EINVAL);
   if (newsize > rip->i_sp->s_max_size)	/* don't let inode grow too big */
 	return(EFBIG);
+  if (rip->i_size == newsize)
+	return(OK);
 
   /* Free the actual space if truncating. */
   if (newsize < rip->i_size) {
diff --git a/servers/mfs/link.c b/servers/mfs/link.c
index f43e2e945..580988e2c 100644
--- a/servers/mfs/link.c
+++ b/servers/mfs/link.c
@@ -525,17 +525,19 @@ off_t newsize;			/* inode must become this size */
   file_type = rip->i_mode & I_TYPE;	/* check to see if file is special */
   if (file_type == I_CHAR_SPECIAL || file_type == I_BLOCK_SPECIAL)
 	return(EINVAL);
-  if(newsize > rip->i_sp->s_max_size)	/* don't let inode grow too big */
+  if (rip->i_size == newsize)
+	return(OK);
+  if (newsize > rip->i_sp->s_max_size)	/* don't let inode grow too big */
 	return(EFBIG);
 
   /* Free the actual space if truncating. */
-  if(newsize < rip->i_size) {
+  if (newsize < rip->i_size) {
   	if ((r = freesp_inode(rip, newsize, rip->i_size)) != OK)
   		return(r);
   }
 
   /* Clear the rest of the last zone if expanding. */
-  if(newsize > rip->i_size) clear_zone(rip, rip->i_size, 0);
+  if (newsize > rip->i_size) clear_zone(rip, rip->i_size, 0);
 
   /* Next correct the inode size. */
   rip->i_size = newsize;
diff --git a/test/test16.c b/test/test16.c
index ac5a1e40d..033bdcff0 100644
--- a/test/test16.c
+++ b/test/test16.c
@@ -204,6 +204,15 @@ void test16a()
   if (unlink("T16.i1") != 0) e(84); 
   if (unlink("T16.j") != 0) e(85); 
   if (unlink("T16.k") != 0) e(86); 
+
+  /* Test the times for truncate. */
+  if (system("echo 1 > T16.l") != 0) e(87);
+  stat("T16.l", &s);
+  get_times("T16.l", &a, &c, &m);
+  sleep(1);
+  truncate("T16.l", s.st_size);
+  get_times("T16.l", &ta, &tc, &tm);
+  if (a != ta || c != tc || m != tm) e(88);
 }
 
 void get_times(name, a, c, m)