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author | Tejun Heo <tj@kernel.org> | 2014-05-13 12:16:21 -0400 |
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committer | Tejun Heo <tj@kernel.org> | 2014-05-13 12:16:21 -0400 |
commit | 451af504df0c62f695a69b83c250486e77c66378 (patch) | |
tree | f89879cf3f88e9da346d8bd3fa1ae192a280d772 /mm/hugetlb_cgroup.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 'mm/hugetlb_cgroup.c')
-rw-r--r-- | mm/hugetlb_cgroup.c | 17 |
1 files changed, 9 insertions, 8 deletions
diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c index 372f1adca491..191de26b0148 100644 --- a/mm/hugetlb_cgroup.c +++ b/mm/hugetlb_cgroup.c @@ -253,15 +253,16 @@ static u64 hugetlb_cgroup_read_u64(struct cgroup_subsys_state *css, return res_counter_read_u64(&h_cg->hugepage[idx], name); } -static int hugetlb_cgroup_write(struct cgroup_subsys_state *css, - struct cftype *cft, char *buffer) +static ssize_t hugetlb_cgroup_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off) { int idx, name, ret; unsigned long long val; - struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(css); + struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(of_css(of)); - idx = MEMFILE_IDX(cft->private); - name = MEMFILE_ATTR(cft->private); + buf = strstrip(buf); + idx = MEMFILE_IDX(of_cft(of)->private); + name = MEMFILE_ATTR(of_cft(of)->private); switch (name) { case RES_LIMIT: @@ -271,7 +272,7 @@ static int hugetlb_cgroup_write(struct cgroup_subsys_state *css, break; } /* This function does all necessary parse...reuse it */ - ret = res_counter_memparse_write_strategy(buffer, &val); + ret = res_counter_memparse_write_strategy(buf, &val); if (ret) break; ret = res_counter_set_limit(&h_cg->hugepage[idx], val); @@ -280,7 +281,7 @@ static int hugetlb_cgroup_write(struct cgroup_subsys_state *css, ret = -EINVAL; break; } - return ret; + return ret ?: nbytes; } static int hugetlb_cgroup_reset(struct cgroup_subsys_state *css, @@ -331,7 +332,7 @@ static void __init __hugetlb_cgroup_file_init(int idx) snprintf(cft->name, MAX_CFTYPE_NAME, "%s.limit_in_bytes", buf); cft->private = MEMFILE_PRIVATE(idx, RES_LIMIT); cft->read_u64 = hugetlb_cgroup_read_u64; - cft->write_string = hugetlb_cgroup_write; + cft->write = hugetlb_cgroup_write; /* Add the usage file */ cft = &h->cgroup_files[1]; |