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/block/blk-throttle.c b/block/blk-throttle.c
index 033745c..5e8fd1b 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -1346,10 +1346,10 @@
return 0;
}
-static int tg_set_conf(struct cgroup_subsys_state *css, struct cftype *cft,
- const char *buf, bool is_u64)
+static ssize_t tg_set_conf(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off, bool is_u64)
{
- struct blkcg *blkcg = css_to_blkcg(css);
+ struct blkcg *blkcg = css_to_blkcg(of_css(of));
struct blkg_conf_ctx ctx;
struct throtl_grp *tg;
struct throtl_service_queue *sq;
@@ -1368,9 +1368,9 @@
ctx.v = -1;
if (is_u64)
- *(u64 *)((void *)tg + cft->private) = ctx.v;
+ *(u64 *)((void *)tg + of_cft(of)->private) = ctx.v;
else
- *(unsigned int *)((void *)tg + cft->private) = ctx.v;
+ *(unsigned int *)((void *)tg + of_cft(of)->private) = ctx.v;
throtl_log(&tg->service_queue,
"limit change rbps=%llu wbps=%llu riops=%u wiops=%u",
@@ -1404,19 +1404,19 @@
}
blkg_conf_finish(&ctx);
- return 0;
+ return nbytes;
}
-static int tg_set_conf_u64(struct cgroup_subsys_state *css, struct cftype *cft,
- char *buf)
+static ssize_t tg_set_conf_u64(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
{
- return tg_set_conf(css, cft, buf, true);
+ return tg_set_conf(of, buf, nbytes, off, true);
}
-static int tg_set_conf_uint(struct cgroup_subsys_state *css, struct cftype *cft,
- char *buf)
+static ssize_t tg_set_conf_uint(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
{
- return tg_set_conf(css, cft, buf, false);
+ return tg_set_conf(of, buf, nbytes, off, false);
}
static struct cftype throtl_files[] = {
@@ -1424,25 +1424,25 @@
.name = "throttle.read_bps_device",
.private = offsetof(struct throtl_grp, bps[READ]),
.seq_show = tg_print_conf_u64,
- .write_string = tg_set_conf_u64,
+ .write = tg_set_conf_u64,
},
{
.name = "throttle.write_bps_device",
.private = offsetof(struct throtl_grp, bps[WRITE]),
.seq_show = tg_print_conf_u64,
- .write_string = tg_set_conf_u64,
+ .write = tg_set_conf_u64,
},
{
.name = "throttle.read_iops_device",
.private = offsetof(struct throtl_grp, iops[READ]),
.seq_show = tg_print_conf_uint,
- .write_string = tg_set_conf_uint,
+ .write = tg_set_conf_uint,
},
{
.name = "throttle.write_iops_device",
.private = offsetof(struct throtl_grp, iops[WRITE]),
.seq_show = tg_print_conf_uint,
- .write_string = tg_set_conf_uint,
+ .write = tg_set_conf_uint,
},
{
.name = "throttle.io_service_bytes",