Correctly return ERANGE in getxattr(2)

According to the getxattr(2) man page the ERANGE errno should be
returned when the size of the value buffer is to small to hold the
result.  Prior to this patch the implementation would just truncate
the value to size bytes.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1408

diff --git a/module/zfs/zpl_xattr.c b/module/zfs/zpl_xattr.c
index c03764f..a7e38e6 100644 (file)
--- a/module/zfs/zpl_xattr.c
+++ b/module/zfs/zpl_xattr.c
@@ -225,6 +225,11 @@ zpl_xattr_get_dir(struct inode *ip, const char *name, void *value,
                goto out;
        }
 
+       if (size < i_size_read(xip)) {
+               error = -ERANGE;
+               goto out;
+       }
+
        error = zpl_read_common(xip, value, size, 0, UIO_SYSSPACE, 0, cr);
 out:
        if (xip)
@@ -263,9 +268,12 @@ zpl_xattr_get_sa(struct inode *ip, const char *name, void *value, size_t size)
        if (!size)
                return (nv_size);
 
-       memcpy(value, nv_value, MIN(size, nv_size));
+       if (size < nv_size)
+               return (-ERANGE);
+
+       memcpy(value, nv_value, nv_size);
 
-       return (MIN(size, nv_size));
+       return (nv_size);
 }
 
 static int