[PATCH] fix for cpusets minor problem

This patch fixes minor problem that the CPUSETS have when files in the
cpuset filesystem are read after lseek()-ed beyond the EOF.

Signed-off-by: KUROSAWA Takahiro <kurosawa@valinux.co.jp>
Acked-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 1f06e7690106..712d02029971 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -972,6 +972,10 @@ static ssize_t cpuset_common_file_read(struct file *file, char __user *buf,
         *s++ = '\n';
         *s = '\0';
 
+        /* Do nothing if *ppos is at the eof or beyond the eof. */
+        if (s - page <= *ppos)
+                return 0;
+
         start = page + *ppos;
         n = s - start;
         retval = n - copy_to_user(buf, start, min(n, nbytes));