fs: sysfs: return EGBIG on write if offset is larger than file size

According to the user expectations common utilities like dd or sh
redirection operator > should work correctly over binary files from
sysfs. At the moment doing excessive write can not be completed:

  write(1, "\0\0\0\0\0\0\0\0", 8)         = 4
  write(1, "\0\0\0\0", 4)                 = 0
  write(1, "\0\0\0\0", 4)                 = 0
  write(1, "\0\0\0\0", 4)                 = 0
  ...

Fix the problem by returning EFBIG described in man 2 write.

Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index e9ef59b3abb1..589abee16a39 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -125,7 +125,7 @@ static ssize_t sysfs_kf_bin_write(struct kernfs_open_file *of, char *buf,
 
         if (size) {
                 if (size <= pos)
-                        return 0;
+                        return -EFBIG;
                 count = min_t(ssize_t, count, size - pos);
         }
         if (!count)