[PATCH 2/5] cgroup: replace cftype->write_string() with cftype->write()

From: Tejun Heo
Date: Tue May 06 2014 - 08:44:57 EST

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 doesn't need this as blkg_conf_prep() can 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.

Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
Cc: Vivek Goyal <vgoyal@xxxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: Li Zefan <lizefan@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxx>
Cc: Aristeu Rozanski <arozansk@xxxxxxxxxx>
---
block/blk-throttle.c | 32 ++++++++++++++++----------------
block/cfq-iosched.c | 28 ++++++++++++++--------------
include/linux/cgroup.h | 10 +---------
kernel/cgroup.c | 38 +++++++++++++++++++-------------------
kernel/cgroup_freezer.c | 20 +++++++++-----------
kernel/cpuset.c | 16 +++++++++-------
mm/hugetlb_cgroup.c | 17 +++++++++--------
mm/memcontrol.c | 46 +++++++++++++++++++++++++---------------------
net/ipv4/tcp_memcontrol.c | 16 +++++++++-------
security/device_cgroup.c | 14 +++++++-------
10 files changed, 118 insertions(+), 119 deletions(-)

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 @@ static int tg_print_conf_uint(struct seq_file *sf, void *v)
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 @@ static int tg_set_conf(struct cgroup_subsys_state *css, struct cftype *cft,
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 @@ static int tg_set_conf(struct cgroup_subsys_state *css, struct cftype *cft,
}

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 @@ static struct cftype throtl_files[] = {
.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",
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index e0985f1..a73020b 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -1670,11 +1670,11 @@ static int cfq_print_leaf_weight(struct seq_file *sf, void *v)
return 0;
}

-static int __cfqg_set_weight_device(struct cgroup_subsys_state *css,
- struct cftype *cft, const char *buf,
- bool is_leaf_weight)
+static ssize_t __cfqg_set_weight_device(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off,
+ bool is_leaf_weight)
{
- struct blkcg *blkcg = css_to_blkcg(css);
+ struct blkcg *blkcg = css_to_blkcg(of_css(of));
struct blkg_conf_ctx ctx;
struct cfq_group *cfqg;
int ret;
@@ -1697,19 +1697,19 @@ static int __cfqg_set_weight_device(struct cgroup_subsys_state *css,
}

blkg_conf_finish(&ctx);
- return ret;
+ return ret ?: nbytes;
}

-static int cfqg_set_weight_device(struct cgroup_subsys_state *css,
- struct cftype *cft, char *buf)
+static ssize_t cfqg_set_weight_device(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
{
- return __cfqg_set_weight_device(css, cft, buf, false);
+ return __cfqg_set_weight_device(of, buf, nbytes, off, false);
}

-static int cfqg_set_leaf_weight_device(struct cgroup_subsys_state *css,
- struct cftype *cft, char *buf)
+static ssize_t cfqg_set_leaf_weight_device(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
{
- return __cfqg_set_weight_device(css, cft, buf, true);
+ return __cfqg_set_weight_device(of, buf, nbytes, off, true);
}

static int __cfq_set_weight(struct cgroup_subsys_state *css, struct cftype *cft,
@@ -1837,7 +1837,7 @@ static struct cftype cfq_blkcg_files[] = {
.name = "weight_device",
.flags = CFTYPE_ONLY_ON_ROOT,
.seq_show = cfqg_print_leaf_weight_device,
- .write_string = cfqg_set_leaf_weight_device,
+ .write = cfqg_set_leaf_weight_device,
},
{
.name = "weight",
@@ -1851,7 +1851,7 @@ static struct cftype cfq_blkcg_files[] = {
.name = "weight_device",
.flags = CFTYPE_NOT_ON_ROOT,
.seq_show = cfqg_print_weight_device,
- .write_string = cfqg_set_weight_device,
+ .write = cfqg_set_weight_device,
},
{
.name = "weight",
@@ -1863,7 +1863,7 @@ static struct cftype cfq_blkcg_files[] = {
{
.name = "leaf_weight_device",
.seq_show = cfqg_print_leaf_weight_device,
- .write_string = cfqg_set_leaf_weight_device,
+ .write = cfqg_set_leaf_weight_device,
},
{
.name = "leaf_weight",
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index da7a0ca..5f717d7 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -455,8 +455,7 @@ struct cftype {

/*
* 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;

@@ -503,13 +502,6 @@ struct cftype {
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
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 32d1624..8939fe4 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1035,7 +1035,7 @@ static umode_t cgroup_file_mode(const struct cftype *cft)
mode |= S_IRUGO;

if (cft->write_u64 || cft->write_s64 || cft->write ||
- cft->write_string || cft->trigger)
+ cft->trigger)
mode |= S_IWUSR;

return mode;
@@ -2352,20 +2352,21 @@ static int cgroup_procs_write(struct cgroup_subsys_state *css,
return attach_task_by_pid(css->cgroup, tgid, true);
}

-static int cgroup_release_agent_write(struct cgroup_subsys_state *css,
- struct cftype *cft, char *buffer)
+static ssize_t cgroup_release_agent_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
{
- struct cgroup_root *root = css->cgroup->root;
+ struct cgroup *cgrp = of_css(of)->cgroup;
+ struct cgroup_root *root = cgrp->root;

BUILD_BUG_ON(sizeof(root->release_agent_path) < PATH_MAX);
- if (!cgroup_lock_live_group(css->cgroup))
+ if (!cgroup_lock_live_group(cgrp))
return -ENODEV;
spin_lock(&release_agent_path_lock);
- strlcpy(root->release_agent_path, buffer,
+ strlcpy(root->release_agent_path, strstrip(buf),
sizeof(root->release_agent_path));
spin_unlock(&release_agent_path_lock);
mutex_unlock(&cgroup_mutex);
- return 0;
+ return nbytes;
}

static int cgroup_release_agent_show(struct seq_file *seq, void *v)
@@ -2530,21 +2531,22 @@ out_finish:
}

/* change the enabled child controllers for a cgroup in the default hierarchy */
-static int cgroup_subtree_control_write(struct cgroup_subsys_state *dummy_css,
- struct cftype *cft, char *buffer)
+static ssize_t cgroup_subtree_control_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes,
+ loff_t off)
{
unsigned int enable = 0, disable = 0;
- struct cgroup *cgrp = dummy_css->cgroup, *child;
+ struct cgroup *cgrp = of_css(of)->cgroup, *child;
struct cgroup_subsys *ss;
- char *tok, *p;
+ char *tok;
int ssid, ret;

/*
* Parse input - space separated list of subsystem names prefixed
* with either + or -.
*/
- p = buffer;
- while ((tok = strsep(&p, " "))) {
+ buf = strstrip(buf);
+ while ((tok = strsep(&buf, " "))) {
for_each_subsys(ss, ssid) {
if (ss->disabled || strcmp(tok + 1, ss->name))
continue;
@@ -2690,7 +2692,7 @@ out_unlock_tree:
out_unbreak:
kernfs_unbreak_active_protection(cgrp->control_kn);
cgroup_put(cgrp);
- return ret;
+ return ret ?: nbytes;

err_undo_css:
cgrp->child_subsys_mask &= ~enable;
@@ -2736,9 +2738,7 @@ static ssize_t cgroup_file_write(struct kernfs_open_file *of, char *buf,
css = cgroup_css(cgrp, cft->ss);
rcu_read_unlock();

- if (cft->write_string) {
- ret = cft->write_string(css, cft, strstrip(buf));
- } else if (cft->write_u64) {
+ if (cft->write_u64) {
unsigned long long v;
ret = kstrtoull(buf, 0, &v);
if (!ret)
@@ -3982,7 +3982,7 @@ static struct cftype cgroup_base_files[] = {
.name = "cgroup.subtree_control",
.flags = CFTYPE_ONLY_ON_DFL,
.seq_show = cgroup_subtree_control_show,
- .write_string = cgroup_subtree_control_write,
+ .write = cgroup_subtree_control_write,
},
{
.name = "cgroup.populated",
@@ -4016,7 +4016,7 @@ static struct cftype cgroup_base_files[] = {
.name = "release_agent",
.flags = CFTYPE_INSANE | CFTYPE_ONLY_ON_ROOT,
.seq_show = cgroup_release_agent_show,
- .write_string = cgroup_release_agent_write,
+ .write = cgroup_release_agent_write,
.max_write_len = PATH_MAX - 1,
},
{ } /* terminate */
diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c
index 2bc4a22..d2b4bc7 100644
--- a/kernel/cgroup_freezer.c
+++ b/kernel/cgroup_freezer.c
@@ -71,10 +71,6 @@ 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)
@@ -441,20 +437,22 @@ static void freezer_change_state(struct freezer *freezer, bool freeze)
rcu_read_unlock();
}

-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,
@@ -478,7 +476,7 @@ 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",
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 7c0e8da..97cbb59 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -1603,13 +1603,15 @@ out_unlock:
/*
* Common handling for a write to a "cpus" or "mems" file.
*/
-static int cpuset_write_resmask(struct cgroup_subsys_state *css,
- struct cftype *cft, char *buf)
+static ssize_t cpuset_write_resmask(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
{
- struct cpuset *cs = css_cs(css);
+ struct cpuset *cs = css_cs(of_css(of));
struct cpuset *trialcs;
int retval = -ENODEV;

+ buf = strstrip(buf);
+
/*
* CPU or memory hotunplug may leave @cs w/o any execution
* resources, in which case the hotplug code asynchronously updates
@@ -1633,7 +1635,7 @@ static int cpuset_write_resmask(struct cgroup_subsys_state *css,
goto out_unlock;
}

- switch (cft->private) {
+ switch (of_cft(of)->private) {
case FILE_CPULIST:
retval = update_cpumask(cs, trialcs, buf);
break;
@@ -1648,7 +1650,7 @@ static int cpuset_write_resmask(struct cgroup_subsys_state *css,
free_trial_cpuset(trialcs);
out_unlock:
mutex_unlock(&cpuset_mutex);
- return retval;
+ return retval ?: nbytes;
}

/*
@@ -1750,7 +1752,7 @@ static struct cftype files[] = {
{
.name = "cpus",
.seq_show = cpuset_common_seq_show,
- .write_string = cpuset_write_resmask,
+ .write = cpuset_write_resmask,
.max_write_len = (100U + 6 * NR_CPUS),
.private = FILE_CPULIST,
},
@@ -1758,7 +1760,7 @@ static struct cftype files[] = {
{
.name = "mems",
.seq_show = cpuset_common_seq_show,
- .write_string = cpuset_write_resmask,
+ .write = cpuset_write_resmask,
.max_write_len = (100U + 6 * MAX_NUMNODES),
.private = FILE_MEMLIST,
},
diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c
index 595d7fd..faea871 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];
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index c3f82f6..0258419 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -5141,17 +5141,18 @@ static int memcg_update_kmem_limit(struct mem_cgroup *memcg,
* The user of this function is...
* RES_LIMIT.
*/
-static int mem_cgroup_write(struct cgroup_subsys_state *css, struct cftype *cft,
- char *buffer)
+static ssize_t mem_cgroup_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
{
- struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+ struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
enum res_type type;
int name;
unsigned long long val;
int ret;

- type = MEMFILE_TYPE(cft->private);
- name = MEMFILE_ATTR(cft->private);
+ buf = strstrip(buf);
+ type = MEMFILE_TYPE(of_cft(of)->private);
+ name = MEMFILE_ATTR(of_cft(of)->private);

switch (name) {
case RES_LIMIT:
@@ -5160,7 +5161,7 @@ static int mem_cgroup_write(struct cgroup_subsys_state *css, struct cftype *cft,
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;
if (type == _MEM)
@@ -5173,7 +5174,7 @@ static int mem_cgroup_write(struct cgroup_subsys_state *css, struct cftype *cft,
return -EINVAL;
break;
case RES_SOFT_LIMIT:
- ret = res_counter_memparse_write_strategy(buffer, &val);
+ ret = res_counter_memparse_write_strategy(buf, &val);
if (ret)
break;
/*
@@ -5190,7 +5191,7 @@ static int mem_cgroup_write(struct cgroup_subsys_state *css, struct cftype *cft,
ret = -EINVAL; /* should be BUG() ? */
break;
}
- return ret;
+ return ret ?: nbytes;
}

static void memcg_get_hierarchical_limit(struct mem_cgroup *memcg,
@@ -5962,9 +5963,10 @@ static void memcg_event_ptable_queue_proc(struct file *file,
* Input must be in format '<event_fd> <control_fd> <args>'.
* Interpretation of args is defined by control file implementation.
*/
-static int memcg_write_event_control(struct cgroup_subsys_state *css,
- struct cftype *cft, char *buffer)
+static ssize_t memcg_write_event_control(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
{
+ struct cgroup_subsys_state *css = of_css(of);
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
struct mem_cgroup_event *event;
struct cgroup_subsys_state *cfile_css;
@@ -5975,15 +5977,17 @@ static int memcg_write_event_control(struct cgroup_subsys_state *css,
char *endp;
int ret;

- efd = simple_strtoul(buffer, &endp, 10);
+ buf = strstrip(buf);
+
+ efd = simple_strtoul(buf, &endp, 10);
if (*endp != ' ')
return -EINVAL;
- buffer = endp + 1;
+ buf = endp + 1;

- cfd = simple_strtoul(buffer, &endp, 10);
+ cfd = simple_strtoul(buf, &endp, 10);
if ((*endp != ' ') && (*endp != '\0'))
return -EINVAL;
- buffer = endp + 1;
+ buf = endp + 1;

event = kzalloc(sizeof(*event), GFP_KERNEL);
if (!event)
@@ -6061,7 +6065,7 @@ static int memcg_write_event_control(struct cgroup_subsys_state *css,
goto out_put_cfile;
}

- ret = event->register_event(memcg, event->eventfd, buffer);
+ ret = event->register_event(memcg, event->eventfd, buf);
if (ret)
goto out_put_css;

@@ -6074,7 +6078,7 @@ static int memcg_write_event_control(struct cgroup_subsys_state *css,
fdput(cfile);
fdput(efile);

- return 0;
+ return nbytes;

out_put_css:
css_put(css);
@@ -6105,13 +6109,13 @@ static struct cftype mem_cgroup_files[] = {
{
.name = "limit_in_bytes",
.private = MEMFILE_PRIVATE(_MEM, RES_LIMIT),
- .write_string = mem_cgroup_write,
+ .write = mem_cgroup_write,
.read_u64 = mem_cgroup_read_u64,
},
{
.name = "soft_limit_in_bytes",
.private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT),
- .write_string = mem_cgroup_write,
+ .write = mem_cgroup_write,
.read_u64 = mem_cgroup_read_u64,
},
{
@@ -6136,7 +6140,7 @@ static struct cftype mem_cgroup_files[] = {
},
{
.name = "cgroup.event_control", /* XXX: for compat */
- .write_string = memcg_write_event_control,
+ .write = memcg_write_event_control,
.flags = CFTYPE_NO_PREFIX,
.mode = S_IWUGO,
},
@@ -6169,7 +6173,7 @@ static struct cftype mem_cgroup_files[] = {
{
.name = "kmem.limit_in_bytes",
.private = MEMFILE_PRIVATE(_KMEM, RES_LIMIT),
- .write_string = mem_cgroup_write,
+ .write = mem_cgroup_write,
.read_u64 = mem_cgroup_read_u64,
},
{
@@ -6215,7 +6219,7 @@ static struct cftype memsw_cgroup_files[] = {
{
.name = "memsw.limit_in_bytes",
.private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT),
- .write_string = mem_cgroup_write,
+ .write = mem_cgroup_write,
.read_u64 = mem_cgroup_read_u64,
},
{
diff --git a/net/ipv4/tcp_memcontrol.c b/net/ipv4/tcp_memcontrol.c
index d4f015a..841fd3f 100644
--- a/net/ipv4/tcp_memcontrol.c
+++ b/net/ipv4/tcp_memcontrol.c
@@ -102,17 +102,19 @@ static int tcp_update_limit(struct mem_cgroup *memcg, u64 val)
return 0;
}

-static int tcp_cgroup_write(struct cgroup_subsys_state *css, struct cftype *cft,
- char *buffer)
+static ssize_t tcp_cgroup_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
{
- struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+ struct mem_cgroup *memcg = mem_cgroup_from_css(of_css(of));
unsigned long long val;
int ret = 0;

- switch (cft->private) {
+ buf = strstrip(buf);
+
+ switch (of_cft(of)->private) {
case RES_LIMIT:
/* see memcontrol.c */
- ret = res_counter_memparse_write_strategy(buffer, &val);
+ ret = res_counter_memparse_write_strategy(buf, &val);
if (ret)
break;
ret = tcp_update_limit(memcg, val);
@@ -121,7 +123,7 @@ static int tcp_cgroup_write(struct cgroup_subsys_state *css, struct cftype *cft,
ret = -EINVAL;
break;
}
- return ret;
+ return ret ?: nbytes;
}

static u64 tcp_read_stat(struct mem_cgroup *memcg, int type, u64 default_val)
@@ -193,7 +195,7 @@ static int tcp_cgroup_reset(struct cgroup_subsys_state *css, unsigned int event)
static struct cftype tcp_files[] = {
{
.name = "kmem.tcp.limit_in_bytes",
- .write_string = tcp_cgroup_write,
+ .write = tcp_cgroup_write,
.read_u64 = tcp_cgroup_read,
.private = RES_LIMIT,
},
diff --git a/security/device_cgroup.c b/security/device_cgroup.c
index 8365909..82d6b4f 100644
--- a/security/device_cgroup.c
+++ b/security/device_cgroup.c
@@ -651,27 +651,27 @@ static int devcgroup_update_access(struct dev_cgroup *devcgroup,
return rc;
}

-static int devcgroup_access_write(struct cgroup_subsys_state *css,
- struct cftype *cft, char *buffer)
+static ssize_t devcgroup_access_write(struct kernfs_open_file *of,
+ char *buf, size_t nbytes, loff_t off)
{
int retval;

mutex_lock(&devcgroup_mutex);
- retval = devcgroup_update_access(css_to_devcgroup(css),
- cft->private, buffer);
+ retval = devcgroup_update_access(css_to_devcgroup(of_css(of)),
+ of_cft(of)->private, strstrip(buf));
mutex_unlock(&devcgroup_mutex);
- return retval;
+ return retval ?: nbytes;
}

static struct cftype dev_cgroup_files[] = {
{
.name = "allow",
- .write_string = devcgroup_access_write,
+ .write = devcgroup_access_write,
.private = DEVCG_ALLOW,
},
{
.name = "deny",
- .write_string = devcgroup_access_write,
+ .write = devcgroup_access_write,
.private = DEVCG_DENY,
},
{
--
1.9.0

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