Commit 22c36d18 authored by Jonathan Corbet's avatar Jonathan Corbet

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: default avatarJonathan Corbet <corbet@lwn.net>
parent b69d3987
...@@ -122,8 +122,7 @@ stop() is the place to free it. ...@@ -122,8 +122,7 @@ stop() is the place to free it.
} }
Finally, the show() function should format the object currently pointed to 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 by the iterator for output. The example module's show() function is:
something goes wrong. The example module's show() function is:
static int ct_seq_show(struct seq_file *s, void *v) static int ct_seq_show(struct seq_file *s, void *v)
{ {
...@@ -132,6 +131,12 @@ something goes wrong. The example module's show() function is: ...@@ -132,6 +131,12 @@ something goes wrong. The example module's show() function is:
return 0; 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 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 seq_file iterator is finished by creating a seq_operations structure with
the four functions we have just defined: the four functions we have just defined:
......
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