cgroup: replace cftype->write_string() with cftype->write()
Convert all cftype->write_string() users to the new cftype->write()
which maps directly to kernfs write operation and has full access to
kernfs and cgroup contexts. The conversions are mostly mechanical.
* @css and @cft are accessed using of_css() and of_cft() accessors
respectively instead of being specified as arguments.
* Should return @nbytes on success instead of 0.
* @buf is not trimmed automatically. Trim if necessary. Note that
blkcg and netprio don't need this as the parsers already handle
whitespaces.
cftype->write_string() has no user left after the conversions and
removed.
While at it, remove unnecessary local variable @p in
cgroup_subtree_control_write() and stale comment about
CGROUP_LOCAL_BUFFER_SIZE in cgroup_freezer.c.
This patch doesn't introduce any visible behavior changes.
v2: netprio was missing from conversion. Converted.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Aristeu Rozanski <arozansk@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: "David S. Miller" <davem@davemloft.net>
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index c5a170c..aecdc84 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -453,8 +453,7 @@
/*
* The maximum length of string, excluding trailing nul, that can
- * be passed to write_string. If < PAGE_SIZE-1, PAGE_SIZE-1 is
- * assumed.
+ * be passed to write. If < PAGE_SIZE-1, PAGE_SIZE-1 is assumed.
*/
size_t max_write_len;
@@ -501,13 +500,6 @@
s64 val);
/*
- * write_string() is passed a nul-terminated kernelspace
- * buffer of maximum length determined by max_write_len.
- * Returns 0 or -ve error code.
- */
- int (*write_string)(struct cgroup_subsys_state *css, struct cftype *cft,
- char *buffer);
- /*
* trigger() callback can be used to get some kick from the
* userspace, when the actual string written is not important
* at all. The private field can be used to determine the