Document SEQ_SKIP
2.6.26 adds a SEQ_SKIP return value for the seq_file show() function;
update the documentation to match.
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
diff --git a/Documentation/filesystems/seq_file.txt b/Documentation/filesystems/seq_file.txt
index 7fb8e6d..0ab92c2 100644
--- a/Documentation/filesystems/seq_file.txt
+++ b/Documentation/filesystems/seq_file.txt
@@ -122,8 +122,7 @@
}
Finally, the show() function should format the object currently pointed to
-by the iterator for output. It should return zero, or an error code if
-something goes wrong. The example module's show() function is:
+by the iterator for output. The example module's show() function is:
static int ct_seq_show(struct seq_file *s, void *v)
{
@@ -132,6 +131,12 @@
return 0;
}
+If all is well, the show() function should return zero. A negative error
+code in the usual manner indicates that something went wrong; it will be
+passed back to user space. This function can also return SEQ_SKIP, which
+causes the current item to be skipped; if the show() function has already
+generated output before returning SEQ_SKIP, that output will be dropped.
+
We will look at seq_printf() in a moment. But first, the definition of the
seq_file iterator is finished by creating a seq_operations structure with
the four functions we have just defined: