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| author | Tejun Heo <tj@kernel.org> | 2014-05-13 12:16:21 -0400 |
|---|---|---|
| committer | Tejun Heo <tj@kernel.org> | 2014-05-13 12:16:21 -0400 |
| commit | 451af504df0c62f695a69b83c250486e77c66378 (patch) | |
| tree | f89879cf3f88e9da346d8bd3fa1ae192a280d772 /kernel/cgroup_freezer.c | |
| parent | b41686401e501430ffe93b575ef7959d2ecc6f2e (diff) | |
| download | lwn-451af504df0c62f695a69b83c250486e77c66378.tar.gz lwn-451af504df0c62f695a69b83c250486e77c66378.zip | |
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>
Diffstat (limited to 'kernel/cgroup_freezer.c')
| -rw-r--r-- | kernel/cgroup_freezer.c | 20 |
1 files changed, 9 insertions, 11 deletions
diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c index 0398f7e9ac81..6b4e60e33a9a 100644 --- a/kernel/cgroup_freezer.c +++ b/kernel/cgroup_freezer.c @@ -73,10 +73,6 @@ bool cgroup_freezing(struct task_struct *task) return ret; } -/* - * cgroups_write_string() limits the size of freezer state strings to - * CGROUP_LOCAL_BUFFER_SIZE - */ static const char *freezer_state_strs(unsigned int state) { if (state & CGROUP_FROZEN) @@ -423,20 +419,22 @@ static void freezer_change_state(struct freezer *freezer, bool freeze) mutex_unlock(&freezer_mutex); } -static int freezer_write(struct cgroup_subsys_state *css, struct cftype *cft, - char *buffer) +static ssize_t freezer_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off) { bool freeze; - if (strcmp(buffer, freezer_state_strs(0)) == 0) + buf = strstrip(buf); + + if (strcmp(buf, freezer_state_strs(0)) == 0) freeze = false; - else if (strcmp(buffer, freezer_state_strs(CGROUP_FROZEN)) == 0) + else if (strcmp(buf, freezer_state_strs(CGROUP_FROZEN)) == 0) freeze = true; else return -EINVAL; - freezer_change_state(css_freezer(css), freeze); - return 0; + freezer_change_state(css_freezer(of_css(of)), freeze); + return nbytes; } static u64 freezer_self_freezing_read(struct cgroup_subsys_state *css, @@ -460,7 +458,7 @@ static struct cftype files[] = { .name = "state", .flags = CFTYPE_NOT_ON_ROOT, .seq_show = freezer_read, - .write_string = freezer_write, + .write = freezer_write, }, { .name = "self_freezing", |