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authorLinus Torvalds <torvalds@linux-foundation.org>2014-01-21 17:51:34 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-01-21 17:51:34 -0800
commitf075e0f6993f41c72dbb1d3e7a2d7740f14e89e2 (patch)
treea25b464a67fffc6f43940e0e85e2735a48bb1ad7
parent5cb7398caf69e3943df78435a19a8a77fe8b9463 (diff)
parentdd4b0a4676907481256d16d5de0851b315a6f22c (diff)
downloadlinux-f075e0f6993f41c72dbb1d3e7a2d7740f14e89e2.tar.bz2
Merge branch 'for-3.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo: "The bulk of changes are cleanups and preparations for the upcoming kernfs conversion. - cgroup_event mechanism which is and will be used only by memcg is moved to memcg. - pidlist handling is updated so that it can be served by seq_file. Also, the list is not sorted if sane_behavior. cgroup documentation explicitly states that the file is not sorted but it has been for quite some time. - All cgroup file handling now happens on top of seq_file. This is to prepare for kernfs conversion. In addition, all operations are restructured so that they map 1-1 to kernfs operations. - Other cleanups and low-pri fixes" * 'for-3.14' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (40 commits) cgroup: trivial style updates cgroup: remove stray references to css_id doc: cgroups: Fix typo in doc/cgroups cgroup: fix fail path in cgroup_load_subsys() cgroup: fix missing unlock on error in cgroup_load_subsys() cgroup: remove for_each_root_subsys() cgroup: implement for_each_css() cgroup: factor out cgroup_subsys_state creation into create_css() cgroup: combine css handling loops in cgroup_create() cgroup: reorder operations in cgroup_create() cgroup: make for_each_subsys() useable under cgroup_root_mutex cgroup: css iterations and css_from_dir() are safe under cgroup_mutex cgroup: unify pidlist and other file handling cgroup: replace cftype->read_seq_string() with cftype->seq_show() cgroup: attach cgroup_open_file to all cgroup files cgroup: generalize cgroup_pidlist_open_file cgroup: unify read path so that seq_file is always used cgroup: unify cgroup_write_X64() and cgroup_write_string() cgroup: remove cftype->read(), ->read_map() and ->write() hugetlb_cgroup: convert away from cftype->read() ...
Diffstat
-rw-r--r--Documentation/cgroups/cgroups.txt20
-rw-r--r--Documentation/cgroups/memory.txt4
-rw-r--r--Documentation/cgroups/resource_counter.txt4
-rw-r--r--block/blk-throttle.c35
-rw-r--r--block/cfq-iosched.c131
-rw-r--r--drivers/md/bcache/request.c1
-rw-r--r--include/linux/cgroup.h112
-rw-r--r--include/linux/vmpressure.h8
-rw-r--r--init/Kconfig3
-rw-r--r--kernel/cgroup.c1202
-rw-r--r--kernel/cgroup_freezer.c7
-rw-r--r--kernel/cpuset.c71
-rw-r--r--kernel/sched/core.c13
-rw-r--r--kernel/sched/cpuacct.c18
-rw-r--r--mm/hugetlb_cgroup.c22
-rw-r--r--mm/memcontrol.c426
-rw-r--r--mm/page_cgroup.c2
-rw-r--r--mm/vmpressure.c26
-rw-r--r--net/core/netprio_cgroup.c8
-rw-r--r--security/device_cgroup.c7
20 files changed, 1022 insertions, 1098 deletions
diff --git a/Documentation/cgroups/cgroups.txt b/Documentation/cgroups/cgroups.txt
index 638bf17ff869..821de56d1580 100644
--- a/Documentation/cgroups/cgroups.txt
+++ b/Documentation/cgroups/cgroups.txt
@@ -24,7 +24,6 @@ CONTENTS:
2.1 Basic Usage
2.2 Attaching processes
2.3 Mounting hierarchies by name
- 2.4 Notification API
3. Kernel API
3.1 Overview
3.2 Synchronization
@@ -472,25 +471,6 @@ you give a subsystem a name.
The name of the subsystem appears as part of the hierarchy description
in /proc/mounts and /proc/<pid>/cgroups.
-2.4 Notification API
---------------------
-
-There is mechanism which allows to get notifications about changing
-status of a cgroup.
-
-To register a new notification handler you need to:
- - create a file descriptor for event notification using eventfd(2);
- - open a control file to be monitored (e.g. memory.usage_in_bytes);
- - write "<event_fd> <control_fd> <args>" to cgroup.event_control.
- Interpretation of args is defined by control file implementation;
-
-eventfd will be woken up by control file implementation or when the
-cgroup is removed.
-
-To unregister a notification handler just close eventfd.
-
-NOTE: Support of notifications should be implemented for the control
-file. See documentation for the subsystem.
3. Kernel API
=============
diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt
index e2bc132608fd..2622115276aa 100644
--- a/Documentation/cgroups/memory.txt
+++ b/Documentation/cgroups/memory.txt
@@ -577,7 +577,7 @@ Each memcg's numa_stat file includes "total", "file", "anon" and "unevictable"
per-node page counts including "hierarchical_<counter>" which sums up all
hierarchical children's values in addition to the memcg's own value.
-The ouput format of memory.numa_stat is:
+The output format of memory.numa_stat is:
total=<total pages> N0=<node 0 pages> N1=<node 1 pages> ...
file=<total file pages> N0=<node 0 pages> N1=<node 1 pages> ...
@@ -670,7 +670,7 @@ page tables.
8.1 Interface
-This feature is disabled by default. It can be enabledi (and disabled again) by
+This feature is disabled by default. It can be enabled (and disabled again) by
writing to memory.move_charge_at_immigrate of the destination cgroup.
If you want to enable it:
diff --git a/Documentation/cgroups/resource_counter.txt b/Documentation/cgroups/resource_counter.txt
index c4d99ed0b418..52e1da16a309 100644
--- a/Documentation/cgroups/resource_counter.txt
+++ b/Documentation/cgroups/resource_counter.txt
@@ -97,8 +97,8 @@ to work with it.
(struct res_counter *rc, struct res_counter *top,
unsinged long val)
- Almost same as res_cunter_uncharge() but propagation of uncharge
- stops when rc == top. This is useful when kill a res_coutner in
+ Almost same as res_counter_uncharge() but propagation of uncharge
+ stops when rc == top. This is useful when kill a res_counter in
child cgroup.
2.1 Other accounting routines
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 06534049afba..a760857e6b62 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -1303,13 +1303,10 @@ static u64 tg_prfill_cpu_rwstat(struct seq_file *sf,
return __blkg_prfill_rwstat(sf, pd, &rwstat);
}
-static int tg_print_cpu_rwstat(struct cgroup_subsys_state *css,
- struct cftype *cft, struct seq_file *sf)
+static int tg_print_cpu_rwstat(struct seq_file *sf, void *v)
{
- struct blkcg *blkcg = css_to_blkcg(css);
-
- blkcg_print_blkgs(sf, blkcg, tg_prfill_cpu_rwstat, &blkcg_policy_throtl,
- cft->private, true);
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), tg_prfill_cpu_rwstat,
+ &blkcg_policy_throtl, seq_cft(sf)->private, true);
return 0;
}
@@ -1335,19 +1332,17 @@ static u64 tg_prfill_conf_uint(struct seq_file *sf, struct blkg_policy_data *pd,
return __blkg_prfill_u64(sf, pd, v);
}
-static int tg_print_conf_u64(struct cgroup_subsys_state *css,
- struct cftype *cft, struct seq_file *sf)
+static int tg_print_conf_u64(struct seq_file *sf, void *v)
{
- blkcg_print_blkgs(sf, css_to_blkcg(css), tg_prfill_conf_u64,
- &blkcg_policy_throtl, cft->private, false);
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), tg_prfill_conf_u64,
+ &blkcg_policy_throtl, seq_cft(sf)->private, false);
return 0;
}
-static int tg_print_conf_uint(struct cgroup_subsys_state *css,
- struct cftype *cft, struct seq_file *sf)
+static int tg_print_conf_uint(struct seq_file *sf, void *v)
{
- blkcg_print_blkgs(sf, css_to_blkcg(css), tg_prfill_conf_uint,
- &blkcg_policy_throtl, cft->private, false);
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), tg_prfill_conf_uint,
+ &blkcg_policy_throtl, seq_cft(sf)->private, false);
return 0;
}
@@ -1428,40 +1423,40 @@ static struct cftype throtl_files[] = {
{
.name = "throttle.read_bps_device",
.private = offsetof(struct throtl_grp, bps[READ]),
- .read_seq_string = tg_print_conf_u64,
+ .seq_show = tg_print_conf_u64,
.write_string = tg_set_conf_u64,
.max_write_len = 256,
},
{
.name = "throttle.write_bps_device",
.private = offsetof(struct throtl_grp, bps[WRITE]),
- .read_seq_string = tg_print_conf_u64,
+ .seq_show = tg_print_conf_u64,
.write_string = tg_set_conf_u64,
.max_write_len = 256,
},
{
.name = "throttle.read_iops_device",
.private = offsetof(struct throtl_grp, iops[READ]),
- .read_seq_string = tg_print_conf_uint,
+ .seq_show = tg_print_conf_uint,
.write_string = tg_set_conf_uint,
.max_write_len = 256,
},
{
.name = "throttle.write_iops_device",
.private = offsetof(struct throtl_grp, iops[WRITE]),
- .read_seq_string = tg_print_conf_uint,
+ .seq_show = tg_print_conf_uint,
.write_string = tg_set_conf_uint,
.max_write_len = 256,
},
{
.name = "throttle.io_service_bytes",
.private = offsetof(struct tg_stats_cpu, service_bytes),
- .read_seq_string = tg_print_cpu_rwstat,
+ .seq_show = tg_print_cpu_rwstat,
},
{
.name = "throttle.io_serviced",
.private = offsetof(struct tg_stats_cpu, serviced),
- .read_seq_string = tg_print_cpu_rwstat,
+ .seq_show = tg_print_cpu_rwstat,
},
{ } /* terminate */
};
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index 4d5cec1ad80d..744833b630c6 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -1632,11 +1632,11 @@ static u64 cfqg_prfill_weight_device(struct seq_file *sf,
return __blkg_prfill_u64(sf, pd, cfqg->dev_weight);
}
-static int cfqg_print_weight_device(struct cgroup_subsys_state *css,
- struct cftype *cft, struct seq_file *sf)
+static int cfqg_print_weight_device(struct seq_file *sf, void *v)
{
- blkcg_print_blkgs(sf, css_to_blkcg(css), cfqg_prfill_weight_device,
- &blkcg_policy_cfq, 0, false);
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
+ cfqg_prfill_weight_device, &blkcg_policy_cfq,
+ 0, false);
return 0;
}
@@ -1650,26 +1650,23 @@ static u64 cfqg_prfill_leaf_weight_device(struct seq_file *sf,
return __blkg_prfill_u64(sf, pd, cfqg->dev_leaf_weight);
}
-static int cfqg_print_leaf_weight_device(struct cgroup_subsys_state *css,
- struct cftype *cft,
- struct seq_file *sf)
+static int cfqg_print_leaf_weight_device(struct seq_file *sf, void *v)
{
- blkcg_print_blkgs(sf, css_to_blkcg(css), cfqg_prfill_leaf_weight_device,
- &blkcg_policy_cfq, 0, false);
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
+ cfqg_prfill_leaf_weight_device, &blkcg_policy_cfq,
+ 0, false);
return 0;
}
-static int cfq_print_weight(struct cgroup_subsys_state *css, struct cftype *cft,
- struct seq_file *sf)
+static int cfq_print_weight(struct seq_file *sf, void *v)
{
- seq_printf(sf, "%u\n", css_to_blkcg(css)->cfq_weight);
+ seq_printf(sf, "%u\n", css_to_blkcg(seq_css(sf))->cfq_weight);
return 0;
}
-static int cfq_print_leaf_weight(struct cgroup_subsys_state *css,
- struct cftype *cft, struct seq_file *sf)
+static int cfq_print_leaf_weight(struct seq_file *sf, void *v)
{
- seq_printf(sf, "%u\n", css_to_blkcg(css)->cfq_leaf_weight);
+ seq_printf(sf, "%u\n", css_to_blkcg(seq_css(sf))->cfq_leaf_weight);
return 0;
}
@@ -1762,23 +1759,17 @@ static int cfq_set_leaf_weight(struct cgroup_subsys_state *css,
return __cfq_set_weight(css, cft, val, true);
}
-static int cfqg_print_stat(struct cgroup_subsys_state *css, struct cftype *cft,
- struct seq_file *sf)
+static int cfqg_print_stat(struct seq_file *sf, void *v)
{
- struct blkcg *blkcg = css_to_blkcg(css);
-
- blkcg_print_blkgs(sf, blkcg, blkg_prfill_stat, &blkcg_policy_cfq,
- cft->private, false);
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), blkg_prfill_stat,
+ &blkcg_policy_cfq, seq_cft(sf)->private, false);
return 0;
}
-static int cfqg_print_rwstat(struct cgroup_subsys_state *css,
- struct cftype *cft, struct seq_file *sf)
+static int cfqg_print_rwstat(struct seq_file *sf, void *v)
{
- struct blkcg *blkcg = css_to_blkcg(css);
-
- blkcg_print_blkgs(sf, blkcg, blkg_prfill_rwstat, &blkcg_policy_cfq,
- cft->private, true);
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)), blkg_prfill_rwstat,
+ &blkcg_policy_cfq, seq_cft(sf)->private, true);
return 0;
}
@@ -1798,23 +1789,19 @@ static u64 cfqg_prfill_rwstat_recursive(struct seq_file *sf,
return __blkg_prfill_rwstat(sf, pd, &sum);
}
-static int cfqg_print_stat_recursive(struct cgroup_subsys_state *css,
- struct cftype *cft, struct seq_file *sf)
+static int cfqg_print_stat_recursive(struct seq_file *sf, void *v)
{
- struct blkcg *blkcg = css_to_blkcg(css);
-
- blkcg_print_blkgs(sf, blkcg, cfqg_prfill_stat_recursive,
- &blkcg_policy_cfq, cft->private, false);
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
+ cfqg_prfill_stat_recursive, &blkcg_policy_cfq,
+ seq_cft(sf)->private, false);
return 0;
}
-static int cfqg_print_rwstat_recursive(struct cgroup_subsys_state *css,
- struct cftype *cft, struct seq_file *sf)
+static int cfqg_print_rwstat_recursive(struct seq_file *sf, void *v)
{
- struct blkcg *blkcg = css_to_blkcg(css);
-
- blkcg_print_blkgs(sf, blkcg, cfqg_prfill_rwstat_recursive,
- &blkcg_policy_cfq, cft->private, true);
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
+ cfqg_prfill_rwstat_recursive, &blkcg_policy_cfq,
+ seq_cft(sf)->private, true);
return 0;
}
@@ -1835,13 +1822,11 @@ static u64 cfqg_prfill_avg_queue_size(struct seq_file *sf,
}
/* print avg_queue_size */
-static int cfqg_print_avg_queue_size(struct cgroup_subsys_state *css,
- struct cftype *cft, struct seq_file *sf)
+static int cfqg_print_avg_queue_size(struct seq_file *sf, void *v)
{
- struct blkcg *blkcg = css_to_blkcg(css);
-
- blkcg_print_blkgs(sf, blkcg, cfqg_prfill_avg_queue_size,
- &blkcg_policy_cfq, 0, false);
+ blkcg_print_blkgs(sf, css_to_blkcg(seq_css(sf)),
+ cfqg_prfill_avg_queue_size, &blkcg_policy_cfq,
+ 0, false);
return 0;
}
#endif /* CONFIG_DEBUG_BLK_CGROUP */
@@ -1851,14 +1836,14 @@ static struct cftype cfq_blkcg_files[] = {
{
.name = "weight_device",
.flags = CFTYPE_ONLY_ON_ROOT,
- .read_seq_string = cfqg_print_leaf_weight_device,
+ .seq_show = cfqg_print_leaf_weight_device,
.write_string = cfqg_set_leaf_weight_device,
.max_write_len = 256,
},
{
.name = "weight",
.flags = CFTYPE_ONLY_ON_ROOT,
- .read_seq_string = cfq_print_leaf_weight,
+ .seq_show = cfq_print_leaf_weight,
.write_u64 = cfq_set_leaf_weight,
},
@@ -1866,26 +1851,26 @@ static struct cftype cfq_blkcg_files[] = {
{
.name = "weight_device",
.flags = CFTYPE_NOT_ON_ROOT,
- .read_seq_string = cfqg_print_weight_device,
+ .seq_show = cfqg_print_weight_device,
.write_string = cfqg_set_weight_device,
.max_write_len = 256,
},
{
.name = "weight",
.flags = CFTYPE_NOT_ON_ROOT,
- .read_seq_string = cfq_print_weight,
+ .seq_show = cfq_print_weight,
.write_u64 = cfq_set_weight,
},
{
.name = "leaf_weight_device",
- .read_seq_string = cfqg_print_leaf_weight_device,
+ .seq_show = cfqg_print_leaf_weight_device,
.write_string = cfqg_set_leaf_weight_device,
.max_write_len = 256,
},
{
.name = "leaf_weight",
- .read_seq_string = cfq_print_leaf_weight,
+ .seq_show = cfq_print_leaf_weight,
.write_u64 = cfq_set_leaf_weight,
},
@@ -1893,114 +1878,114 @@ static struct cftype cfq_blkcg_files[] = {
{
.name = "time",
.private = offsetof(struct cfq_group, stats.time),
- .read_seq_string = cfqg_print_stat,
+ .seq_show = cfqg_print_stat,
},
{
.name = "sectors",
.private = offsetof(struct cfq_group, stats.sectors),
- .read_seq_string = cfqg_print_stat,
+ .seq_show = cfqg_print_stat,
},
{
.name = "io_service_bytes",
.private = offsetof(struct cfq_group, stats.service_bytes),
- .read_seq_string = cfqg_print_rwstat,
+ .seq_show = cfqg_print_rwstat,
},
{
.name = "io_serviced",
.private = offsetof(struct cfq_group, stats.serviced),
- .read_seq_string = cfqg_print_rwstat,
+ .seq_show = cfqg_print_rwstat,
},
{
.name = "io_service_time",
.private = offsetof(struct cfq_group, stats.service_time),
- .read_seq_string = cfqg_print_rwstat,
+ .seq_show = cfqg_print_rwstat,
},
{
.name = "io_wait_time",
.private = offsetof(struct cfq_group, stats.wait_time),
- .read_seq_string = cfqg_print_rwstat,
+ .seq_show = cfqg_print_rwstat,
},
{
.name = "io_merged",
.private = offsetof(struct cfq_group, stats.merged),
- .read_seq_string = cfqg_print_rwstat,
+ .seq_show = cfqg_print_rwstat,
},
{
.name = "io_queued",
.private = offsetof(struct cfq_group, stats.queued),
- .read_seq_string = cfqg_print_rwstat,
+ .seq_show = cfqg_print_rwstat,
},
/* the same statictics which cover the cfqg and its descendants */
{
.name = "time_recursive",
.private = offsetof(struct cfq_group, stats.time),
- .read_seq_string = cfqg_print_stat_recursive,
+ .seq_show = cfqg_print_stat_recursive,
},
{
.name = "sectors_recursive",
.private = offsetof(struct cfq_group, stats.sectors),
- .read_seq_string = cfqg_print_stat_recursive,
+ .seq_show = cfqg_print_stat_recursive,
},
{
.name = "io_service_bytes_recursive",
.private = offsetof(struct cfq_group, stats.service_bytes),
- .read_seq_string = cfqg_print_rwstat_recursive,
+ .seq_show = cfqg_print_rwstat_recursive,
},
{
.name = "io_serviced_recursive",
.private = offsetof(struct cfq_group, stats.serviced),
- .read_seq_string = cfqg_print_rwstat_recursive,
+ .seq_show = cfqg_print_rwstat_recursive,
},
{
.name = "io_service_time_recursive",
.private = offsetof(struct cfq_group, stats.service_time),
- .read_seq_string = cfqg_print_rwstat_recursive,
+ .seq_show = cfqg_print_rwstat_recursive,
},
{
.name = "io_wait_time_recursive",
.private = offsetof(struct cfq_group, stats.wait_time),
- .read_seq_string = cfqg_print_rwstat_recursive,
+ .seq_show = cfqg_print_rwstat_recursive,
},
{
.name = "io_merged_recursive",
.private = offsetof(struct cfq_group, stats.merged),
- .read_seq_string = cfqg_print_rwstat_recursive,
+ .seq_show = cfqg_print_rwstat_recursive,
},
{
.name = "io_queued_recursive",
.private = offsetof(struct cfq_group, stats.queued),
- .read_seq_string = cfqg_print_rwstat_recursive,
+ .seq_show = cfqg_print_rwstat_recursive,
},
#ifdef CONFIG_DEBUG_BLK_CGROUP
{
.name = "avg_queue_size",
- .read_seq_string = cfqg_print_avg_queue_size,
+ .seq_show = cfqg_print_avg_queue_size,
},
{
.name = "group_wait_time",
.private = offsetof(struct cfq_group, stats.group_wait_time),
- .read_seq_string = cfqg_print_stat,
+ .seq_show = cfqg_print_stat,
},
{
.name = "idle_time",
.private = offsetof(struct cfq_group, stats.idle_time),
- .read_seq_string = cfqg_print_stat,
+ .seq_show = cfqg_print_stat,
},
{
.name = "empty_time",
.private = offsetof(struct cfq_group, stats.empty_time),
- .read_seq_string = cfqg_print_stat,
+ .seq_show = cfqg_print_stat,
},
{
.name = "dequeue",
.private = offsetof(struct cfq_group, stats.dequeue),
- .read_seq_string = cfqg_print_stat,
+ .seq_show = cfqg_print_stat,
},
{
.name = "unaccounted_time",
.private = offsetof(struct cfq_group, stats.unaccounted_time),
- .read_seq_string = cfqg_print_stat,
+ .seq_show = cfqg_print_stat,
},
#endif /* CONFIG_DEBUG_BLK_CGROUP */
{ } /* terminate */
diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c
index fbcc851ed5a5..61bcfc21d2a0 100644
--- a/drivers/md/bcache/request.c
+++ b/drivers/md/bcache/request.c
@@ -163,7 +163,6 @@ static struct cgroup_subsys_state *bcachecg_create(struct cgroup *cgroup)
static void bcachecg_destroy(struct cgroup *cgroup)
{
struct bch_cgroup *cg = cgroup_to_bcache(cgroup);
- free_css_id(&bcache_subsys, &cg->css);
kfree(cg);
}
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index 39c1d9469677..5c097596104b 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -21,6 +21,7 @@
#include <linux/xattr.h>
#include <linux/fs.h>
#include <linux/percpu-refcount.h>
+#include <linux/seq_file.h>
#ifdef CONFIG_CGROUPS
@@ -28,8 +29,6 @@ struct cgroupfs_root;
struct cgroup_subsys;
struct inode;
struct cgroup;
-struct css_id;
-struct eventfd_ctx;
extern int cgroup_init_early(void);
extern int cgroup_init(void);
@@ -79,8 +78,6 @@ struct cgroup_subsys_state {
struct cgroup_subsys_state *parent;
unsigned long flags;
- /* ID for this css, if possible */
- struct css_id __rcu *id;
/* percpu_ref killing and RCU release */
struct rcu_head rcu_head;
@@ -239,10 +236,6 @@ struct cgroup {
struct rcu_head rcu_head;
struct work_struct destroy_work;
- /* List of events which userspace want to receive */
- struct list_head event_list;
- spinlock_t event_list_lock;
-
/* directory xattrs */
struct simple_xattrs xattrs;
};
@@ -280,6 +273,9 @@ enum {
* - "tasks" is removed. Everything should be at process
* granularity. Use "cgroup.procs" instead.
*
+ * - "cgroup.procs" is not sorted. pids will be unique unless they
+ * got recycled inbetween reads.
+ *
* - "release_agent" and "notify_on_release" are removed.
* Replacement notification mechanism will be implemented.
*
@@ -320,9 +316,6 @@ struct cgroupfs_root {
/* Unique id for this hierarchy. */
int hierarchy_id;
- /* A list running through the attached subsystems */
- struct list_head subsys_list;
-
/* The root cgroup for this hierarchy */
struct cgroup top_cgroup;
@@ -389,16 +382,6 @@ struct css_set {
};
/*
- * cgroup_map_cb is an abstract callback API for reporting map-valued
- * control files
- */
-
-struct cgroup_map_cb {
- int (*fill)(struct cgroup_map_cb *cb, const char *key, u64 value);
- void *state;
-};
-
-/*
* struct cftype: handler definitions for cgroup control files
*
* When reading/writing to a file:
@@ -445,10 +428,6 @@ struct cftype {
*/
struct cgroup_subsys *ss;
- int (*open)(struct inode *inode, struct file *file);
- ssize_t (*read)(struct cgroup_subsys_state *css, struct cftype *cft,
- struct file *file,
- char __user *buf, size_t nbytes, loff_t *ppos);
/*
* read_u64() is a shortcut for the common case of returning a
* single integer. Use it in place of read()
@@ -458,24 +437,14 @@ struct cftype {
* read_s64() is a signed version of read_u64()
*/
s64 (*read_s64)(struct cgroup_subsys_state *css, struct cftype *cft);
- /*
- * read_map() is used for defining a map of key/value
- * pairs. It should call cb->fill(cb, key, value) for each
- * entry. The key/value pairs (and their ordering) should not
- * change between reboots.
- */
- int (*read_map)(struct cgroup_subsys_state *css, struct cftype *cft,
- struct cgroup_map_cb *cb);
- /*
- * read_seq_string() is used for outputting a simple sequence
- * using seqfile.
- */
- int (*read_seq_string)(struct cgroup_subsys_state *css,
- struct cftype *cft, struct seq_file *m);
- ssize_t (*write)(struct cgroup_subsys_state *css, struct cftype *cft,
- struct file *file,
- const char __user *buf, size_t nbytes, loff_t *ppos);
+ /* generic seq_file read interface */
+ int (*seq_show)(struct seq_file *sf, void *v);
+
+ /* optional ops, implement all or none */
+ void *(*seq_start)(struct seq_file *sf, loff_t *ppos);
+ void *(*seq_next)(struct seq_file *sf, void *v, loff_t *ppos);
+ void (*seq_stop)(struct seq_file *sf, void *v);
/*
* write_u64() is a shortcut for the common case of accepting
@@ -504,27 +473,6 @@ struct cftype {
* kick type for multiplexing.
*/
int (*trigger)(struct cgroup_subsys_state *css, unsigned int event);
-
- int (*release)(struct inode *inode, struct file *file);
-
- /*
- * register_event() callback will be used to add new userspace
- * waiter for changes related to the cftype. Implement it if
- * you want to provide this functionality. Use eventfd_signal()
- * on eventfd to send notification to userspace.
- */
- int (*register_event)(struct cgroup_subsys_state *css,
- struct cftype *cft, struct eventfd_ctx *eventfd,
- const char *args);
- /*
- * unregister_event() callback will be called when userspace
- * closes the eventfd or on cgroup removing.
- * This callback must be implemented, if you want provide
- * notification functionality.
- */
- void (*unregister_event)(struct cgroup_subsys_state *css,
- struct cftype *cft,
- struct eventfd_ctx *eventfd);
};
/*
@@ -538,6 +486,26 @@ struct cftype_set {
};
/*
+ * cgroupfs file entry, pointed to from leaf dentry->d_fsdata. Don't
+ * access directly.
+ */
+struct cfent {
+ struct list_head node;
+ struct dentry *dentry;
+ struct cftype *type;
+ struct cgroup_subsys_state *css;
+
+ /* file xattrs */
+ struct simple_xattrs xattrs;
+};
+
+/* seq_file->private points to the following, only ->priv is public */
+struct cgroup_open_file {
+ struct cfent *cfe;
+ void *priv;
+};
+
+/*
* See the comment above CGRP_ROOT_SANE_BEHAVIOR for details. This
* function can be called as long as @cgrp is accessible.
*/
@@ -552,6 +520,18 @@ static inline const char *cgroup_name(const struct cgroup *cgrp)
return rcu_dereference(cgrp->name)->name;
}
+static inline struct cgroup_subsys_state *seq_css(struct seq_file *seq)
+{
+ struct cgroup_open_file *of = seq->private;
+ return of->cfe->css;
+}
+
+static inline struct cftype *seq_cft(struct seq_file *seq)
+{
+ struct cgroup_open_file *of = seq->private;
+ return of->cfe->type;
+}
+
int cgroup_add_cftypes(struct cgroup_subsys *ss, struct cftype *cfts);
int cgroup_rm_cftypes(struct cftype *cfts);
@@ -631,12 +611,8 @@ struct cgroup_subsys {
#define MAX_CGROUP_TYPE_NAMELEN 32
const char *name;
- /*
- * Link to parent, and list entry in parent's children.
- * Protected by cgroup_lock()
- */
+ /* link to parent, protected by cgroup_lock() */
struct cgroupfs_root *root;
- struct list_head sibling;
/* list of cftype_sets */
struct list_head cftsets;
diff --git a/include/linux/vmpressure.h b/include/linux/vmpressure.h
index 3f3788d49362..3e4535876d37 100644
--- a/include/linux/vmpressure.h
+++ b/include/linux/vmpressure.h
@@ -7,6 +7,7 @@
#include <linux/gfp.h>
#include <linux/types.h>
#include <linux/cgroup.h>
+#include <linux/eventfd.h>
struct vmpressure {
unsigned long scanned;
@@ -33,13 +34,10 @@ extern void vmpressure_init(struct vmpressure *vmpr);
extern void vmpressure_cleanup(struct vmpressure *vmpr);
extern struct vmpressure *memcg_to_vmpressure(struct mem_cgroup *memcg);
extern struct cgroup_subsys_state *vmpressure_to_css(struct vmpressure *vmpr);
-extern struct vmpressure *css_to_vmpressure(struct cgroup_subsys_state *css);
-extern int vmpressure_register_event(struct cgroup_subsys_state *css,
- struct cftype *cft,
+extern int vmpressure_register_event(struct mem_cgroup *memcg,
struct eventfd_ctx *eventfd,
const char *args);
-extern void vmpressure_unregister_event(struct cgroup_subsys_state *css,
- struct cftype *cft,
+extern void vmpressure_unregister_event(struct mem_cgroup *memcg,
struct eventfd_ctx *eventfd);
#else
static inline void vmpressure(gfp_t gfp, struct mem_cgroup *memcg,
diff --git a/init/Kconfig b/init/Kconfig
index 5236dc562a36..8d402e33b7fc 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -854,7 +854,6 @@ config NUMA_BALANCING
menuconfig CGROUPS
boolean "Control Group support"
- depends on EVENTFD
help
This option adds support for grouping sets of processes together, for
use with process control subsystems such as Cpusets, CFS, memory
@@ -921,6 +920,7 @@ config MEMCG
bool "Memory Resource Controller for Control Groups"
depends on RESOURCE_COUNTERS
select MM_OWNER
+ select EVENTFD
help
Provides a memory resource controller that manages both anonymous
memory and page cache. (See Documentation/cgroups/memory.txt)
@@ -1160,7 +1160,6 @@ config UIDGID_STRICT_TYPE_CHECKS
config SCHED_AUTOGROUP
bool "Automatic process group scheduling"
- select EVENTFD
select CGROUPS
select CGROUP_SCHED
select FAIR_GROUP_SCHED
diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index bc1dcabe9217..e2f46ba37f72 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -41,7 +41,6 @@
#include <linux/rcupdate.h>
#include <linux/sched.h>
#include <linux/backing-dev.h>
-#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/magic.h>
#include <linux/spinlock.h>
@@ -56,15 +55,20 @@
#include <linux/pid_namespace.h>
#include <linux/idr.h>
#include <linux/vmalloc.h> /* TODO: replace with more sophisticated array */
-#include <linux/eventfd.h>
-#include <linux/poll.h>
#include <linux/flex_array.h> /* used in cgroup_attach_task */
#include <linux/kthread.h>
-#include <linux/file.h>
#include <linux/atomic.h>
/*
+ * pidlists linger the following amount before being destroyed. The goal
+ * is avoiding frequent destruction in the middle of consecutive read calls
+ * Expiring in the middle is a performance problem not a correctness one.
+ * 1 sec should be enough.
+ */
+#define CGROUP_PIDLIST_DESTROY_DELAY HZ
+
+/*
* cgroup_mutex is the master lock. Any modification to cgroup or its
* hierarchy must be performed while holding it.
*
@@ -89,6 +93,19 @@ static DEFINE_MUTEX(cgroup_mutex);
static DEFINE_MUTEX(cgroup_root_mutex);
+#define cgroup_assert_mutex_or_rcu_locked() \
+ rcu_lockdep_assert(rcu_read_lock_held() || \
+ lockdep_is_held(&cgroup_mutex), \
+ "cgroup_mutex or RCU read lock required");
+
+#ifdef CONFIG_LOCKDEP
+#define cgroup_assert_mutex_or_root_locked() \
+ WARN_ON_ONCE(debug_locks && (!lockdep_is_held(&cgroup_mutex) && \
+ !lockdep_is_held(&cgroup_root_mutex)))
+#else
+#define cgroup_assert_mutex_or_root_locked() do { } while (0)
+#endif
+
/*
* cgroup destruction makes heavy use of work items and there can be a lot
* of concurrent destructions. Use a separate workqueue so that cgroup
@@ -98,6 +115,12 @@ static DEFINE_MUTEX(cgroup_root_mutex);
static struct workqueue_struct *cgroup_destroy_wq;
/*
+ * pidlist destructions need to be flushed on cgroup destruction. Use a
+ * separate workqueue as flush domain.
+ */
+static struct workqueue_struct *cgroup_pidlist_destroy_wq;
+
+/*
* Generate an array of cgroup subsystem pointers. At boot time, this is
* populated with the built in subsystems, and modular subsystems are
* registered after that. The mutable section of this array is protected by
@@ -119,49 +142,6 @@ static struct cgroupfs_root cgroup_dummy_root;
/* dummy_top is a shorthand for the dummy hierarchy's top cgroup */
static struct cgroup * const cgroup_dummy_top = &cgroup_dummy_root.top_cgroup;
-/*
- * cgroupfs file entry, pointed to from leaf dentry->d_fsdata.
- */
-struct cfent {
- struct list_head node;
- struct dentry *dentry;
- struct cftype *type;
- struct cgroup_subsys_state *css;
-
- /* file xattrs */
- struct simple_xattrs xattrs;
-};
-
-/*
- * cgroup_event represents events which userspace want to receive.
- */
-struct cgroup_event {
- /*
- * css which the event belongs to.
- */
- struct cgroup_subsys_state *css;
- /*
- * Control file which the event associated.
- */
- struct cftype *cft;
- /*
- * eventfd to signal userspace about the event.
- */
- struct eventfd_ctx *eventfd;
- /*
- * Each of these stored in a list by the cgroup.
- */
- struct list_head list;
- /*
- * All fields below needed to unregister event when
- * userspace closes eventfd.
- */
- poll_table pt;
- wait_queue_head_t *wqh;
- wait_queue_t wait;
- struct work_struct remove;
-};
-
/* The list of hierarchy roots */
static LIST_HEAD(cgroup_roots);
@@ -200,6 +180,7 @@ static int cgroup_destroy_locked(struct cgroup *cgrp);
static int cgroup_addrm_files(struct cgroup *cgrp, struct cftype cfts[],
bool is_add);
static int cgroup_file_release(struct inode *inode, struct file *file);
+static void cgroup_pidlist_destroy_all(struct cgroup *cgrp);
/**
* cgroup_css - obtain a cgroup's css for the specified subsystem
@@ -262,16 +243,32 @@ static int notify_on_release(const struct cgroup *cgrp)
}
/**
+ * for_each_css - iterate all css's of a cgroup
+ * @css: the iteration cursor
+ * @ssid: the index of the subsystem, CGROUP_SUBSYS_COUNT after reaching the end
+ * @cgrp: the target cgroup to iterate css's of
+ *
+ * Should be called under cgroup_mutex.
+ */
+#define for_each_css(css, ssid, cgrp) \
+ for ((ssid) = 0; (ssid) < CGROUP_SUBSYS_COUNT; (ssid)++) \
+ if (!((css) = rcu_dereference_check( \
+ (cgrp)->subsys[(ssid)], \
+ lockdep_is_held(&cgroup_mutex)))) { } \
+ else
+
+/**
* for_each_subsys - iterate all loaded cgroup subsystems
* @ss: the iteration cursor
- * @i: the index of @ss, CGROUP_SUBSYS_COUNT after reaching the end
+ * @ssid: the index of @ss, CGROUP_SUBSYS_COUNT after reaching the end
*
- * Should be called under cgroup_mutex.
+ * Iterates through all loaded subsystems. Should be called under
+ * cgroup_mutex or cgroup_root_mutex.
*/
-#define for_each_subsys(ss, i) \
- for ((i) = 0; (i) < CGROUP_SUBSYS_COUNT; (i)++) \
- if (({ lockdep_assert_held(&cgroup_mutex); \
- !((ss) = cgroup_subsys[i]); })) { } \
+#define for_each_subsys(ss, ssid) \
+ for (({ cgroup_assert_mutex_or_root_locked(); (ssid) = 0; }); \
+ (ssid) < CGROUP_SUBSYS_COUNT; (ssid)++) \
+ if (!((ss) = cgroup_subsys[(ssid)])) { } \
else
/**
@@ -286,10 +283,6 @@ static int notify_on_release(const struct cgroup *cgrp)
for ((i) = 0; (i) < CGROUP_BUILTIN_SUBSYS_COUNT && \
(((ss) = cgroup_subsys[i]) || true); (i)++)
-/* iterate each subsystem attached to a hierarchy */
-#define for_each_root_subsys(root, ss) \
- list_for_each_entry((ss), &(root)->subsys_list, sibling)
-
/* iterate across the active hierarchies */
#define for_each_active_root(root) \
list_for_each_entry((root), &cgroup_roots, root_list)
@@ -863,11 +856,7 @@ static void cgroup_free_fn(struct work_struct *work)
*/
deactivate_super(cgrp->root->sb);
- /*
- * if we're getting rid of the cgroup, refcount should ensure
- * that there are no pidlists left.
- */
- BUG_ON(!list_empty(&cgrp->pidlists));
+ cgroup_pidlist_destroy_all(cgrp);
simple_xattrs_free(&cgrp->xattrs);
@@ -1050,7 +1039,6 @@ static int rebind_subsystems(struct cgroupfs_root *root,
cgroup_css(cgroup_dummy_top, ss));
cgroup_css(cgrp, ss)->cgroup = cgrp;
- list_move(&ss->sibling, &root->subsys_list);
ss->root = root;
if (ss->bind)
ss->bind(cgroup_css(cgrp, ss));
@@ -1069,7 +1057,6 @@ static int rebind_subsystems(struct cgroupfs_root *root,
RCU_INIT_POINTER(cgrp->subsys[i], NULL);
cgroup_subsys[i]->root = &cgroup_dummy_root;
- list_move(&ss->sibling, &cgroup_dummy_root.subsys_list);
/* subsystem is now free - drop reference on module */
module_put(ss->module);
@@ -1096,10 +1083,12 @@ static int cgroup_show_options(struct seq_file *seq, struct dentry *dentry)
{
struct cgroupfs_root *root = dentry->d_sb->s_fs_info;
struct cgroup_subsys *ss;
+ int ssid;
mutex_lock(&cgroup_root_mutex);
- for_each_root_subsys(root, ss)
- seq_printf(seq, ",%s", ss->name);
+ for_each_subsys(ss, ssid)
+ if (root->subsys_mask & (1 << ssid))
+ seq_printf(seq, ",%s", ss->name);
if (root->flags & CGRP_ROOT_SANE_BEHAVIOR)
seq_puts(seq, ",sane_behavior");
if (root->flags & CGRP_ROOT_NOPREFIX)
@@ -1362,8 +1351,6 @@ static void init_cgroup_housekeeping(struct cgroup *cgrp)
INIT_LIST_HEAD(&cgrp->pidlists);
mutex_init(&cgrp->pidlist_mutex);
cgrp->dummy_css.cgroup = cgrp;
- INIT_LIST_HEAD(&cgrp->event_list);
- spin_lock_init(&cgrp->event_list_lock);
simple_xattrs_init(&cgrp->xattrs);
}
@@ -1371,7 +1358,6 @@ static void init_cgroup_root(struct cgroupfs_root *root)
{
struct cgroup *cgrp = &root->top_cgroup;
- INIT_LIST_HEAD(&root->subsys_list);
INIT_LIST_HEAD(&root->root_list);
root->number_of_cgroups = 1;
cgrp->root = root;
@@ -1693,7 +1679,8 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type,
return ERR_PTR(ret);
}
-static void cgroup_kill_sb(struct super_block *sb) {
+static void cgroup_kill_sb(struct super_block *sb)
+{
struct cgroupfs_root *root = sb->s_fs_info;
struct cgroup *cgrp = &root->top_cgroup;
struct cgrp_cset_link *link, *tmp_link;
@@ -1976,8 +1963,8 @@ static int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk,
bool threadgroup)
{
int retval, i, group_size;
- struct cgroup_subsys *ss, *failed_ss = NULL;
struct cgroupfs_root *root = cgrp->root;
+ struct cgroup_subsys_state *css, *failed_css = NULL;
/* threadgroup list cursor and array */
struct task_struct *leader = tsk;
struct task_and_cgroup *tc;
@@ -2050,13 +2037,11 @@ static int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk,
/*
* step 1: check that we can legitimately attach to the cgroup.
*/
- for_each_root_subsys(root, ss) {
- struct cgroup_subsys_state *css = cgroup_css(cgrp, ss);
-
- if (ss->can_attach) {
- retval = ss->can_attach(css, &tset);
+ for_each_css(css, i, cgrp) {
+ if (css->ss->can_attach) {
+ retval = css->ss->can_attach(css, &tset);
if (retval) {
- failed_ss = ss;
+ failed_css = css;
goto out_cancel_attach;
}
}
@@ -2092,12 +2077,9 @@ static int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk,
/*
* step 4: do subsystem attach callbacks.
*/
- for_each_root_subsys(root, ss) {
- struct cgroup_subsys_state *css = cgroup_css(cgrp, ss);
-
- if (ss->attach)
- ss->attach(css, &tset);
- }
+ for_each_css(css, i, cgrp)
+ if (css->ss->attach)
+ css->ss->attach(css, &tset);
/*
* step 5: success! and cleanup
@@ -2114,13 +2096,11 @@ out_put_css_set_refs:
}
out_cancel_attach:
if (retval) {
- for_each_root_subsys(root, ss) {
- struct cgroup_subsys_state *css = cgroup_css(cgrp, ss);
-
- if (ss == failed_ss)
+ for_each_css(css, i, cgrp) {
+ if (css == failed_css)
break;
- if (ss->cancel_attach)
- ss->cancel_attach(css, &tset);
+ if (css->ss->cancel_attach)
+ css->ss->cancel_attach(css, &tset);
}
}
out_free_group_list:
@@ -2148,7 +2128,7 @@ retry_find_task:
tsk = find_task_by_vpid(pid);
if (!tsk) {
rcu_read_unlock();
- ret= -ESRCH;
+ ret = -ESRCH;
goto out_unlock_cgroup;
}
/*
@@ -2260,10 +2240,9 @@ static int cgroup_release_agent_write(struct cgroup_subsys_state *css,
return 0;
}
-static int cgroup_release_agent_show(struct cgroup_subsys_state *css,
- struct cftype *cft, struct seq_file *seq)
+static int cgroup_release_agent_show(struct seq_file *seq, void *v)
{
- struct cgroup *cgrp = css->cgroup;
+ struct cgroup *cgrp = seq_css(seq)->cgroup;
if (!cgroup_lock_live_group(cgrp))
return -ENODEV;
@@ -2273,174 +2252,129 @@ static int cgroup_release_agent_show(struct cgroup_subsys_state *css,
return 0;
}
-static int cgroup_sane_behavior_show(struct cgroup_subsys_state *css,
- struct cftype *cft, struct seq_file *seq)
+static int cgroup_sane_behavior_show(struct seq_file *seq, void *v)
{
- seq_printf(seq, "%d\n", cgroup_sane_behavior(css->cgroup));
+ struct cgroup *cgrp = seq_css(seq)->cgroup;
+
+ seq_printf(seq, "%d\n", cgroup_sane_behavior(cgrp));
return 0;
}
/* A buffer size big enough for numbers or short strings */
#define CGROUP_LOCAL_BUFFER_SIZE 64
-static ssize_t cgroup_write_X64(struct cgroup_subsys_state *css,
- struct cftype *cft, struct file *file,
- const char __user *userbuf, size_t nbytes,
- loff_t *unused_ppos)
+static ssize_t cgroup_file_write(struct file *file, const char __user *userbuf,
+ size_t nbytes, loff_t *ppos)
{
- char buffer[CGROUP_LOCAL_BUFFER_SIZE];
- int retval = 0;
- char *end;
+ struct cfent *cfe = __d_cfe(file->f_dentry);
+ struct cftype *cft = __d_cft(file->f_dentry);
+ struct cgroup_subsys_state *css = cfe->css;
+ size_t max_bytes = cft->max_write_len ?: CGROUP_LOCAL_BUFFER_SIZE - 1;
+ char *buf;
+ int ret;
- if (!nbytes)
- return -EINVAL;
- if (nbytes >= sizeof(buffer))
+ if (nbytes >= max_bytes)
return -E2BIG;
- if (copy_from_user(buffer, userbuf, nbytes))
- return -EFAULT;
- buffer[nbytes] = 0; /* nul-terminate */
- if (cft->write_u64) {
- u64 val = simple_strtoull(strstrip(buffer), &end, 0);
- if (*end)
- return -EINVAL;
- retval = cft->write_u64(css, cft, val);
+ buf = kmalloc(nbytes + 1, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ if (copy_from_user(buf, userbuf, nbytes)) {
+ ret = -EFAULT;
+ goto out_free;
+ }
+
+ buf[nbytes] = '\0';
+
+ if (cft->write_string) {
+ ret = cft->write_string(css, cft, strstrip(buf));
+ } else if (cft->write_u64) {
+ unsigned long long v;
+ ret = kstrtoull(buf, 0, &v);
+ if (!ret)
+ ret = cft->write_u64(css, cft, v);
+ } else if (cft->write_s64) {
+ long long v;
+ ret = kstrtoll(buf, 0, &v);
+ if (!ret)
+ ret = cft->write_s64(css, cft, v);
+ } else if (cft->trigger) {
+ ret = cft->trigger(css, (unsigned int)cft->private);
} else {
- s64 val = simple_strtoll(strstrip(buffer), &end, 0);
- if (*end)
- return -EINVAL;
- retval = cft->write_s64(css, cft, val);
+ ret = -EINVAL;
}
- if (!retval)
- retval = nbytes;
- return retval;
+out_free:
+ kfree(buf);
+ return ret ?: nbytes;
}
-static ssize_t cgroup_write_string(struct cgroup_subsys_state *css,
- struct cftype *cft, struct file *file,
- const char __user *userbuf, size_t nbytes,
- loff_t *unused_ppos)
+/*
+ * seqfile ops/methods for returning structured data. Currently just
+ * supports string->u64 maps, but can be extended in future.
+ */
+
+static void *cgroup_seqfile_start(struct seq_file *seq, loff_t *ppos)
{
- char local_buffer[CGROUP_LOCAL_BUFFER_SIZE];
- int retval = 0;
- size_t max_bytes = cft->max_write_len;
- char *buffer = local_buffer;
+ struct cftype *cft = seq_cft(seq);
- if (!max_bytes)
- max_bytes = sizeof(local_buffer) - 1;
- if (nbytes >= max_bytes)
- return -E2BIG;
- /* Allocate a dynamic buffer if we need one */
- if (nbytes >= sizeof(local_buffer)) {
- buffer = kmalloc(nbytes + 1, GFP_KERNEL);
- if (buffer == NULL)
- return -ENOMEM;
- }
- if (nbytes && copy_from_user(buffer, userbuf, nbytes)) {
- retval = -EFAULT;
- goto out;
+ if (cft->seq_start) {
+ return cft->seq_start(seq, ppos);
+ } else {
+ /*
+ * The same behavior and code as single_open(). Returns
+ * !NULL if pos is at the beginning; otherwise, NULL.
+ */
+ return NULL + !*ppos;
}
-
- buffer[nbytes] = 0; /* nul-terminate */
- retval = cft->write_string(css, cft, strstrip(buffer));
- if (!retval)
- retval = nbytes;
-out:
- if (buffer != local_buffer)
- kfree(buffer);
- return retval;
}
-static ssize_t cgroup_file_write(struct file *file, const char __user *buf,
- size_t nbytes, loff_t *ppos)
+static void *cgroup_seqfile_next(struct seq_file *seq, void *v, loff_t *ppos)
{
- struct cfent *cfe = __d_cfe(file->f_dentry);
- struct cftype *cft = __d_cft(file->f_dentry);
- struct cgroup_subsys_state *css = cfe->css;
+ struct cftype *cft = seq_cft(seq);
- if (cft->write)
- return cft->write(css, cft, file, buf, nbytes, ppos);
- if (cft->write_u64 || cft->write_s64)
- return cgroup_write_X64(css, cft, file, buf, nbytes, ppos);
- if (cft->write_string)
- return cgroup_write_string(css, cft, file, buf, nbytes, ppos);
- if (cft->trigger) {
- int ret = cft->trigger(css, (unsigned int)cft->private);
- return ret ? ret : nbytes;
+ if (cft->seq_next) {
+ return cft->seq_next(seq, v, ppos);
+ } else {
+ /*
+ * The same behavior and code as single_open(), always
+ * terminate after the initial read.
+ */
+ ++*ppos;
+ return NULL;
}
- return -EINVAL;
}
-static ssize_t cgroup_read_u64(struct cgroup_subsys_state *css,
- struct cftype *cft, struct file *file,
- char __user *buf, size_t nbytes, loff_t *ppos)
+static void cgroup_seqfile_stop(struct seq_file *seq, void *v)
{
- char tmp[CGROUP_LOCAL_BUFFER_SIZE];
- u64 val = cft->read_u64(css, cft);
- int len = sprintf(tmp, "%llu\n", (unsigned long long) val);
+ struct cftype *cft = seq_cft(seq);
- return simple_read_from_buffer(buf, nbytes, ppos, tmp, len);
+ if (cft->seq_stop)
+ cft->seq_stop(seq, v);
}
-static ssize_t cgroup_read_s64(struct cgroup_subsys_state *css,
- struct cftype *cft, struct file *file,
- char __user *buf, size_t nbytes, loff_t *ppos)
+static int cgroup_seqfile_show(struct seq_file *m, void *arg)
{
- char tmp[CGROUP_LOCAL_BUFFER_SIZE];
- s64 val = cft->read_s64(css, cft);
- int len = sprintf(tmp, "%lld\n", (long long) val);
+ struct cftype *cft = seq_cft(m);
+ struct cgroup_subsys_state *css = seq_css(m);
- return simple_read_from_buffer(buf, nbytes, ppos, tmp, len);
-}
+ if (cft->seq_show)
+ return cft->seq_show(m, arg);
-static ssize_t cgroup_file_read(struct file *file, char __user *buf,
- size_t nbytes, loff_t *ppos)
-{
- struct cfent *cfe = __d_cfe(file->f_dentry);
- struct cftype *cft = __d_cft(file->f_dentry);
- struct cgroup_subsys_state *css = cfe->css;
-
- if (cft->read)
- return cft->read(css, cft, file, buf, nbytes, ppos);
if (cft->read_u64)
- return cgroup_read_u64(css, cft, file, buf, nbytes, ppos);
- if (cft->read_s64)
- return cgroup_read_s64(css, cft, file, buf, nbytes, ppos);
- return -EINVAL;
-}
-
-/*
- * seqfile ops/methods for returning structured data. Currently just
- * supports string->u64 maps, but can be extended in future.
- */
-
-static int cgroup_map_add(struct cgroup_map_cb *cb, const char *key, u64 value)
-{
- struct seq_file *sf = cb->state;
- return seq_printf(sf, "%s %llu\n", key, (unsigned long long)value);
-}
-
-static int cgroup_seqfile_show(struct seq_file *m, void *arg)
-{
- struct cfent *cfe = m->private;
- struct cftype *cft = cfe->type;
- struct cgroup_subsys_state *css = cfe->css;
-
- if (cft->read_map) {
- struct cgroup_map_cb cb = {
- .fill = cgroup_map_add,
- .state = m,
- };
- return cft->read_map(css, cft, &cb);
- }
- return cft->read_seq_string(css, cft, m);
+ seq_printf(m, "%llu\n", cft->read_u64(css, cft));
+ else if (cft->read_s64)
+ seq_printf(m, "%lld\n", cft->read_s64(css, cft));
+ else
+ return -EINVAL;
+ return 0;
}
-static const struct file_operations cgroup_seqfile_operations = {
- .read = seq_read,
- .write = cgroup_file_write,
- .llseek = seq_lseek,
- .release = cgroup_file_release,
+static struct seq_operations cgroup_seq_operations = {
+ .start = cgroup_seqfile_start,
+ .next = cgroup_seqfile_next,
+ .stop = cgroup_seqfile_stop,
+ .show = cgroup_seqfile_show,
};
static int cgroup_file_open(struct inode *inode, struct file *file)
@@ -2449,6 +2383,7 @@ static int cgroup_file_open(struct inode *inode, struct file *file)
struct cftype *cft = __d_cft(file->f_dentry);
struct cgroup *cgrp = __d_cgrp(cfe->dentry->d_parent);
struct cgroup_subsys_state *css;
+ struct cgroup_open_file *of;
int err;
err = generic_file_open(inode, file);
@@ -2478,32 +2413,26 @@ static int cgroup_file_open(struct inode *inode, struct file *file)
WARN_ON_ONCE(cfe->css && cfe->css != css);
cfe->css = css;
- if (cft->read_map || cft->read_seq_string) {
- file->f_op = &cgroup_seqfile_operations;
- err = single_open(file, cgroup_seqfile_show, cfe);
- } else if (cft->open) {
- err = cft->open(inode, file);
+ of = __seq_open_private(file, &cgroup_seq_operations,
+ sizeof(struct cgroup_open_file));
+ if (of) {
+ of->cfe = cfe;
+ return 0;
}
- if (css->ss && err)
+ if (css->ss)
css_put(css);
- return err;
+ return -ENOMEM;
}
static int cgroup_file_release(struct inode *inode, struct file *file)
{
struct cfent *cfe = __d_cfe(file->f_dentry);
- struct cftype *cft = __d_cft(file->f_dentry);
struct cgroup_subsys_state *css = cfe->css;
- int ret = 0;
- if (cft->release)
- ret = cft->release(inode, file);
if (css->ss)
css_put(css);
- if (file->f_op == &cgroup_seqfile_operations)
- single_release(inode, file);
- return ret;
+ return seq_release_private(inode, file);
}
/*
@@ -2614,7 +2543,7 @@ static ssize_t cgroup_listxattr(struct dentry *dentry, char *buf, size_t size)
}
static const struct file_operations cgroup_file_operations = {
- .read = cgroup_file_read,
+ .read = seq_read,
.write = cgroup_file_write,
.llseek = generic_file_llseek,
.open = cgroup_file_open,
@@ -2639,16 +2568,6 @@ static const struct inode_operations cgroup_dir_inode_operations = {
.removexattr = cgroup_removexattr,
};
-/*
- * Check if a file is a control file
- */
-static inline struct cftype *__file_cft(struct file *file)
-{
- if (file_inode(file)->i_fop != &cgroup_file_operations)
- return ERR_PTR(-EINVAL);
- return __d_cft(file->f_dentry);
-}
-
static int cgroup_create_file(struct dentry *dentry, umode_t mode,
struct super_block *sb)
{
@@ -2706,12 +2625,11 @@ static umode_t cgroup_file_mode(const struct cftype *cft)
if (cft->mode)
return cft->mode;
- if (cft->read || cft->read_u64 || cft->read_s64 ||
- cft->read_map || cft->read_seq_string)
+ if (cft->read_u64 || cft->read_s64 || cft->seq_show)
mode |= S_IRUGO;
- if (cft->write || cft->write_u64 || cft->write_s64 ||
- cft->write_string || cft->trigger)
+ if (cft->write_u64 || cft->write_s64 || cft->write_string ||
+ cft->trigger)
mode |= S_IWUSR;
return mode;
@@ -3007,9 +2925,9 @@ static void cgroup_enable_task_cg_lists(void)
* @parent_css: css whose children to walk
*
* This function returns the next child of @parent_css and should be called
- * under RCU read lock. The only requirement is that @parent_css and
- * @pos_css are accessible. The next sibling is guaranteed to be returned
- * regardless of their states.
+ * under either cgroup_mutex or RCU read lock. The only requirement is
+ * that @parent_css and @pos_css are accessible. The next sibling is
+ * guaranteed to be returned regardless of their states.
*/
struct cgroup_subsys_state *
css_next_child(struct cgroup_subsys_state *pos_css,
@@ -3019,7 +2937,7 @@ css_next_child(struct cgroup_subsys_state *pos_css,
struct cgroup *cgrp = parent_css->cgroup;
struct cgroup *next;
- WARN_ON_ONCE(!rcu_read_lock_held());
+ cgroup_assert_mutex_or_rcu_locked();
/*
* @pos could already have been removed. Once a cgroup is removed,
@@ -3066,10 +2984,10 @@ EXPORT_SYMBOL_GPL(css_next_child);
* to visit for pre-order traversal of @root's descendants. @root is
* included in the iteration and the first node to be visited.
*
- * While this function requires RCU read locking, it doesn't require the
- * whole traversal to be contained in a single RCU critical section. This
- * function will return the correct next descendant as long as both @pos
- * and @root are accessible and @pos is a descendant of @root.
+ * While this function requires cgroup_mutex or RCU read locking, it
+ * doesn't require the whole traversal to be contained in a single critical
+ * section. This function will return the correct next descendant as long
+ * as both @pos and @root are accessible and @pos is a descendant of @root.
*/
struct cgroup_subsys_state *
css_next_descendant_pre(struct cgroup_subsys_state *pos,
@@ -3077,7 +2995,7 @@ css_next_descendant_pre(struct cgroup_subsys_state *pos,
{
struct cgroup_subsys_state *next;
- WARN_ON_ONCE(!rcu_read_lock_held());
+ cgroup_assert_mutex_or_rcu_locked();
/* if first iteration, visit @root */
if (!pos)
@@ -3108,17 +3026,17 @@ EXPORT_SYMBOL_GPL(css_next_descendant_pre);
* is returned. This can be used during pre-order traversal to skip
* subtree of @pos.
*
- * While this function requires RCU read locking, it doesn't require the
- * whole traversal to be contained in a single RCU critical section. This
- * function will return the correct rightmost descendant as long as @pos is
- * accessible.
+ * While this function requires cgroup_mutex or RCU read locking, it
+ * doesn't require the whole traversal to be contained in a single critical
+ * section. This function will return the correct rightmost descendant as
+ * long as @pos is accessible.
*/
struct cgroup_subsys_state *
css_rightmost_descendant(struct cgroup_subsys_state *pos)
{
struct cgroup_subsys_state *last, *tmp;
- WARN_ON_ONCE(!rcu_read_lock_held());
+ cgroup_assert_mutex_or_rcu_locked();
do {
last = pos;
@@ -3154,10 +3072,11 @@ css_leftmost_descendant(struct cgroup_subsys_state *pos)
* to visit for post-order traversal of @root's descendants. @root is
* included in the iteration and the last node to be visited.
*
- * While this function requires RCU read locking, it doesn't require the
- * whole traversal to be contained in a single RCU critical section. This
- * function will return the correct next descendant as long as both @pos
- * and @cgroup are accessible and @pos is a descendant of @cgroup.
+ * While this function requires cgroup_mutex or RCU read locking, it
+ * doesn't require the whole traversal to be contained in a single critical
+ * section. This function will return the correct next descendant as long
+ * as both @pos and @cgroup are accessible and @pos is a descendant of
+ * @cgroup.
*/
struct cgroup_subsys_state *
css_next_descendant_post(struct cgroup_subsys_state *pos,
@@ -3165,7 +3084,7 @@ css_next_descendant_post(struct cgroup_subsys_state *pos,
{
struct cgroup_subsys_state *next;
- WARN_ON_ONCE(!rcu_read_lock_held());
+ cgroup_assert_mutex_or_rcu_locked();
/* if first iteration, visit leftmost descendant which may be @root */
if (!pos)
@@ -3504,14 +3423,12 @@ struct cgroup_pidlist {
pid_t *list;
/* how many elements the above list has */
int length;
- /* how many files are using the current array */
- int use_count;
/* each of these stored in a list by its cgroup */
struct list_head links;
/* pointer to the cgroup we belong to, for list removal purposes */
struct cgroup *owner;
- /* protects the other fields */
- struct rw_semaphore rwsem;
+ /* for delayed destruction */
+ struct delayed_work destroy_dwork;
};
/*
@@ -3527,6 +3444,7 @@ static void *pidlist_allocate(int count)
else
return kmalloc(count * sizeof(pid_t), GFP_KERNEL);
}
+
static void pidlist_free(void *p)
{
if (is_vmalloc_addr(p))
@@ -3536,6 +3454,47 @@ static void pidlist_free(void *p)
}
/*
+ * Used to destroy all pidlists lingering waiting for destroy timer. None
+ * should be left afterwards.
+ */
+static void cgroup_pidlist_destroy_all(struct cgroup *cgrp)
+{
+ struct cgroup_pidlist *l, *tmp_l;
+
+ mutex_lock(&cgrp->pidlist_mutex);
+ list_for_each_entry_safe(l, tmp_l, &cgrp->pidlists, links)
+ mod_delayed_work(cgroup_pidlist_destroy_wq, &l->destroy_dwork, 0);
+ mutex_unlock(&cgrp->pidlist_mutex);
+
+ flush_workqueue(cgroup_pidlist_destroy_wq);
+ BUG_ON(!list_empty(&cgrp->pidlists));
+}
+
+static void cgroup_pidlist_destroy_work_fn(struct work_struct *work)
+{
+ struct delayed_work *dwork = to_delayed_work(work);
+ struct cgroup_pidlist *l = container_of(dwork, struct cgroup_pidlist,
+ destroy_dwork);
+ struct cgroup_pidlist *tofree = NULL;
+
+ mutex_lock(&l->owner->pidlist_mutex);
+
+ /*
+ * Destroy iff we didn't get queued again. The state won't change
+ * as destroy_dwork can only be queued while locked.
+ */
+ if (!delayed_work_pending(dwork)) {
+ list_del(&l->links);
+ pidlist_free(l->list);
+ put_pid_ns(l->key.ns);
+ tofree = l;
+ }
+
+ mutex_unlock(&l->owner->pidlist_mutex);
+ kfree(tofree);
+}
+
+/*
* pidlist_uniq - given a kmalloc()ed list, strip out all duplicate entries
* Returns the number of unique elements.
*/
@@ -3565,52 +3524,92 @@ after:
return dest;
}
+/*
+ * The two pid files - task and cgroup.procs - guaranteed that the result
+ * is sorted, which forced this whole pidlist fiasco. As pid order is
+ * different per namespace, each namespace needs differently sorted list,
+ * making it impossible to use, for example, single rbtree of member tasks
+ * sorted by task pointer. As pidlists can be fairly large, allocating one
+ * per open file is dangerous, so cgroup had to implement shared pool of
+ * pidlists keyed by cgroup and namespace.
+ *
+ * All this extra complexity was caused by the original implementation
+ * committing to an entirely unnecessary property. In the long term, we
+ * want to do away with it. Explicitly scramble sort order if
+ * sane_behavior so that no such expectation exists in the new interface.
+ *
+ * Scrambling is done by swapping every two consecutive bits, which is
+ * non-identity one-to-one mapping which disturbs sort order sufficiently.
+ */
+static pid_t pid_fry(pid_t pid)
+{
+ unsigned a = pid & 0x55555555;
+ unsigned b = pid & 0xAAAAAAAA;
+
+ return (a << 1) | (b >> 1);
+}
+
+static pid_t cgroup_pid_fry(struct cgroup *cgrp, pid_t pid)
+{
+ if (cgroup_sane_behavior(cgrp))
+ return pid_fry(pid);
+ else
+ return pid;
+}
+
static int cmppid(const void *a, const void *b)
{
return *(pid_t *)a - *(pid_t *)b;
}
+static int fried_cmppid(const void *a, const void *b)
+{
+ return pid_fry(*(pid_t *)a) - pid_fry(*(pid_t *)b);
+}
+
+static struct cgroup_pidlist *cgroup_pidlist_find(struct cgroup *cgrp,
+ enum cgroup_filetype type)
+{
+ struct cgroup_pidlist *l;
+ /* don't need task_nsproxy() if we're looking at ourself */
+ struct pid_namespace *ns = task_active_pid_ns(current);
+
+ lockdep_assert_held(&cgrp->pidlist_mutex);
+
+ list_for_each_entry(l, &cgrp->pidlists, links)
+ if (l->key.type == type && l->key.ns == ns)
+ return l;
+ return NULL;
+}
+
/*
* find the appropriate pidlist for our purpose (given procs vs tasks)
* returns with the lock on that pidlist already held, and takes care
* of the use count, or returns NULL with no locks held if we're out of
* memory.
*/
-static struct cgroup_pidlist *cgroup_pidlist_find(struct cgroup *cgrp,
- enum cgroup_filetype type)
+static struct cgroup_pidlist *cgroup_pidlist_find_create(struct cgroup *cgrp,
+ enum cgroup_filetype type)
{
struct cgroup_pidlist *l;
- /* don't need task_nsproxy() if we're looking at ourself */
- struct pid_namespace *ns = task_active_pid_ns(current);
- /*
- * We can't drop the pidlist_mutex before taking the l->rwsem in case
- * the last ref-holder is trying to remove l from the list at the same
- * time. Holding the pidlist_mutex precludes somebody taking whichever
- * list we find out from under us - compare release_pid_array().
- */
- mutex_lock(&cgrp->pidlist_mutex);
- list_for_each_entry(l, &cgrp->pidlists, links) {
- if (l->key.type == type && l->key.ns == ns) {
- /* make sure l doesn't vanish out from under us */
- down_write(&l->rwsem);
- mutex_unlock(&cgrp->pidlist_mutex);
- return l;
- }
- }
+ lockdep_assert_held(&cgrp->pidlist_mutex);
+
+ l = cgroup_pidlist_find(cgrp, type);
+ if (l)
+ return l;
+
/* entry not found; create a new one */
l = kzalloc(sizeof(struct cgroup_pidlist), GFP_KERNEL);
- if (!l) {
- mutex_unlock(&cgrp->pidlist_mutex);
+ if (!l)
return l;
- }
- init_rwsem(&l->rwsem);
- down_write(&l->rwsem);
+
+ INIT_DELAYED_WORK(&l->destroy_dwork, cgroup_pidlist_destroy_work_fn);
l->key.type = type;
- l->key.ns = get_pid_ns(ns);
+ /* don't need task_nsproxy() if we're looking at ourself */
+ l->key.ns = get_pid_ns(task_active_pid_ns(current));
l->owner = cgrp;
list_add(&l->links, &cgrp->pidlists);
- mutex_unlock(&cgrp->pidlist_mutex);
return l;
}
@@ -3627,6 +3626,8 @@ static int pidlist_array_load(struct cgroup *cgrp, enum cgroup_filetype type,
struct task_struct *tsk;
struct cgroup_pidlist *l;
+ lockdep_assert_held(&cgrp->pidlist_mutex);
+
/*
* If cgroup gets more users after we read count, we won't have
* enough space - tough. This race is indistinguishable to the
@@ -3653,20 +3654,24 @@ static int pidlist_array_load(struct cgroup *cgrp, enum cgroup_filetype type,
css_task_iter_end(&it);
length = n;
/* now sort & (if procs) strip out duplicates */
- sort(array, length, sizeof(pid_t), cmppid, NULL);
+ if (cgroup_sane_behavior(cgrp))
+ sort(array, length, sizeof(pid_t), fried_cmppid, NULL);
+ else
+ sort(array, length, sizeof(pid_t), cmppid, NULL);
if (type == CGROUP_FILE_PROCS)
length = pidlist_uniq(array, length);
- l = cgroup_pidlist_find(cgrp, type);
+
+ l = cgroup_pidlist_find_create(cgrp, type);
if (!l) {
+ mutex_unlock(&cgrp->pidlist_mutex);
pidlist_free(array);
return -ENOMEM;
}
- /* store array, freeing old if necessary - lock already held */
+
+ /* store array, freeing old if necessary */
pidlist_free(l->list);
l->list = array;
l->length = length;
- l->use_count++;
- up_write(&l->rwsem);
*lp = l;
return 0;
}
@@ -3740,20 +3745,45 @@ static void *cgroup_pidlist_start(struct seq_file *s, loff_t *pos)
* after a seek to the start). Use a binary-search to find the
* next pid to display, if any
*/
- struct cgroup_pidlist *l = s->private;
+ struct cgroup_open_file *of = s->private;
+ struct cgroup *cgrp = seq_css(s)->cgroup;
+ struct cgroup_pidlist *l;
+ enum cgroup_filetype type = seq_cft(s)->private;
int index = 0, pid = *pos;
- int *iter;
+ int *iter, ret;
+
+ mutex_lock(&cgrp->pidlist_mutex);
+
+ /*
+ * !NULL @of->priv indicates that this isn't the first start()
+ * after open. If the matching pidlist is around, we can use that.
+ * Look for it. Note that @of->priv can't be used directly. It
+ * could already have been destroyed.
+ */
+ if (of->priv)
+ of->priv = cgroup_pidlist_find(cgrp, type);
+
+ /*
+ * Either this is the first start() after open or the matching
+ * pidlist has been destroyed inbetween. Create a new one.
+ */
+ if (!of->priv) {
+ ret = pidlist_array_load(cgrp, type,
+ (struct cgroup_pidlist **)&of->priv);
+ if (ret)
+ return ERR_PTR(ret);
+ }
+ l = of->priv;
- down_read(&l->rwsem);
if (pid) {
int end = l->length;
while (index < end) {
int mid = (index + end) / 2;
- if (l->list[mid] == pid) {
+ if (cgroup_pid_fry(cgrp, l->list[mid]) == pid) {
index = mid;
break;
- } else if (l->list[mid] <= pid)
+ } else if (cgroup_pid_fry(cgrp, l->list[mid]) <= pid)
index = mid + 1;
else
end = mid;
@@ -3764,19 +3794,25 @@ static void *cgroup_pidlist_start(struct seq_file *s, loff_t *pos)
return NULL;
/* Update the abstract position to be the actual pid that we found */
iter = l->list + index;
- *pos = *iter;
+ *pos = cgroup_pid_fry(cgrp, *iter);
return iter;
}
static void cgroup_pidlist_stop(struct seq_file *s, void *v)
{
- struct cgroup_pidlist *l = s->private;
- up_read(&l->rwsem);
+ struct cgroup_open_file *of = s->private;
+ struct cgroup_pidlist *l = of->priv;
+
+ if (l)
+ mod_delayed_work(cgroup_pidlist_destroy_wq, &l->destroy_dwork,
+ CGROUP_PIDLIST_DESTROY_DELAY);
+ mutex_unlock(&seq_css(s)->cgroup->pidlist_mutex);
}
static void *cgroup_pidlist_next(struct seq_file *s, void *v, loff_t *pos)
{
- struct cgroup_pidlist *l = s->private;
+ struct cgroup_open_file *of = s->private;
+ struct cgroup_pidlist *l = of->priv;
pid_t *p = v;
pid_t *end = l->list + l->length;
/*
@@ -3787,7 +3823,7 @@ static void *cgroup_pidlist_next(struct seq_file *s, void *v, loff_t *pos)
if (p >= end) {
return NULL;
} else {
- *pos = *p;
+ *pos = cgroup_pid_fry(seq_css(s)->cgroup, *p);
return p;
}
}
@@ -3808,92 +3844,6 @@ static const struct seq_operations cgroup_pidlist_seq_operations = {
.show = cgroup_pidlist_show,
};
-static void cgroup_release_pid_array(struct cgroup_pidlist *l)
-{
- /*
- * the case where we're the last user of this particular pidlist will
- * have us remove it from the cgroup's list, which entails taking the
- * mutex. since in pidlist_find the pidlist->lock depends on cgroup->
- * pidlist_mutex, we have to take pidlist_mutex first.
- */
- mutex_lock(&l->owner->pidlist_mutex);
- down_write(&l->rwsem);
- BUG_ON(!l->use_count);
- if (!--l->use_count) {
- /* we're the last user if refcount is 0; remove and free */
- list_del(&l->links);
- mutex_unlock(&l->owner->pidlist_mutex);
- pidlist_free(l->list);
- put_pid_ns(l->key.ns);
- up_write(&l->rwsem);
- kfree(l);
- return;
- }
- mutex_unlock(&l->owner->pidlist_mutex);
- up_write(&l->rwsem);
-}
-
-static int cgroup_pidlist_release(struct inode *inode, struct file *file)
-{
- struct cgroup_pidlist *l;
- if (!(file->f_mode & FMODE_READ))
- return 0;
- /*
- * the seq_file will only be initialized if the file was opened for
- * reading; hence we check if it's not null only in that case.
- */
- l = ((struct seq_file *)file->private_data)->private;
- cgroup_release_pid_array(l);
- return seq_release(inode, file);
-}
-
-static const struct file_operations cgroup_pidlist_operations = {
- .read = seq_read,
- .llseek = seq_lseek,
- .write = cgroup_file_write,
- .release = cgroup_pidlist_release,
-};
-
-/*
- * The following functions handle opens on a file that displays a pidlist
- * (tasks or procs). Prepare an array of the process/thread IDs of whoever's
- * in the cgroup.
- */
-/* helper function for the two below it */
-static int cgroup_pidlist_open(struct file *file, enum cgroup_filetype type)
-{
- struct cgroup *cgrp = __d_cgrp(file->f_dentry->d_parent);
- struct cgroup_pidlist *l;
- int retval;
-
- /* Nothing to do for write-only files */
- if (!(file->f_mode & FMODE_READ))
- return 0;
-
- /* have the array populated */
- retval = pidlist_array_load(cgrp, type, &l);
- if (retval)
- return retval;
- /* configure file information */
- file->f_op = &cgroup_pidlist_operations;
-
- retval = seq_open(file, &cgroup_pidlist_seq_operations);
- if (retval) {
- cgroup_release_pid_array(l);
- return retval;
- }
- ((struct seq_file *)file->private_data)->private = l;
- return 0;
-}
-static int cgroup_tasks_open(struct inode *unused, struct file *file)
-{
- return cgroup_pidlist_open(file, CGROUP_FILE_TASKS);
-}
-static int cgroup_procs_open(struct inode *unused, struct file *file)
-{
- return cgroup_pidlist_open(file, CGROUP_FILE_PROCS);
-}
-
static u64 cgroup_read_notify_on_release(struct cgroup_subsys_state *css,
struct cftype *cft)
{
@@ -3928,202 +3878,6 @@ static void cgroup_dput(struct cgroup *cgrp)
deactivate_super(sb);
}
-/*
- * Unregister event and free resources.
- *
- * Gets called from workqueue.
- */
-static void cgroup_event_remove(struct work_struct *work)
-{
- struct cgroup_event *event = container_of(work, struct cgroup_event,
- remove);
- struct cgroup_subsys_state *css = event->css;
-
- remove_wait_queue(event->wqh, &event->wait);
-
- event->cft->unregister_event(css, event->cft, event->eventfd);
-
- /* Notify userspace the event is going away. */
- eventfd_signal(event->eventfd, 1);
-
- eventfd_ctx_put(event->eventfd);
- kfree(event);
- css_put(css);
-}
-
-/*
- * Gets called on POLLHUP on eventfd when user closes it.
- *
- * Called with wqh->lock held and interrupts disabled.
- */
-static int cgroup_event_wake(wait_queue_t *wait, unsigned mode,
- int sync, void *key)
-{
- struct cgroup_event *event = container_of(wait,
- struct cgroup_event, wait);
- struct cgroup *cgrp = event->css->cgroup;
- unsigned long flags = (unsigned long)key;
-
- if (flags & POLLHUP) {
- /*
- * If the event has been detached at cgroup removal, we
- * can simply return knowing the other side will cleanup
- * for us.
- *
- * We can't race against event freeing since the other
- * side will require wqh->lock via remove_wait_queue(),
- * which we hold.
- */
- spin_lock(&cgrp->event_list_lock);
- if (!list_empty(&event->list)) {
- list_del_init(&event->list);
- /*
- * We are in atomic context, but cgroup_event_remove()
- * may sleep, so we have to call it in workqueue.
- */
- schedule_work(&event->remove);
- }
- spin_unlock(&cgrp->event_list_lock);
- }
-
- return 0;
-}
-
-static void cgroup_event_ptable_queue_proc(struct file *file,
- wait_queue_head_t *wqh, poll_table *pt)
-{
- struct cgroup_event *event = container_of(pt,
- struct cgroup_event, pt);
-
- event->wqh = wqh;
- add_wait_queue(wqh, &event->wait);
-}
-
-/*
- * Parse input and register new cgroup event handler.
- *
- * Input must be in format '<event_fd> <control_fd> <args>'.
- * Interpretation of args is defined by control file implementation.
- */
-static int cgroup_write_event_control(struct cgroup_subsys_state *dummy_css,
- struct cftype *cft, const char *buffer)
-{
- struct cgroup *cgrp = dummy_css->cgroup;
- struct cgroup_event *event;
- struct cgroup_subsys_state *cfile_css;
- unsigned int efd, cfd;
- struct fd efile;
- struct fd cfile;
- char *endp;
- int ret;
-
- efd = simple_strtoul(buffer, &endp, 10);
- if (*endp != ' ')
- return -EINVAL;
- buffer = endp + 1;
-
- cfd = simple_strtoul(buffer, &endp, 10);
- if ((*endp != ' ') && (*endp != '\0'))
- return -EINVAL;
- buffer = endp + 1;
-
- event = kzalloc(sizeof(*event), GFP_KERNEL);
- if (!event)
- return -ENOMEM;
-
- INIT_LIST_HEAD(&event->list);
- init_poll_funcptr(&event->pt, cgroup_event_ptable_queue_proc);
- init_waitqueue_func_entry(&event->wait, cgroup_event_wake);
- INIT_WORK(&event->remove, cgroup_event_remove);
-
- efile = fdget(efd);
- if (!efile.file) {
- ret = -EBADF;
- goto out_kfree;
- }
-
- event->eventfd = eventfd_ctx_fileget(efile.file);
- if (IS_ERR(event->eventfd)) {
- ret = PTR_ERR(event->eventfd);
- goto out_put_efile;
- }
-
- cfile = fdget(cfd);
- if (!cfile.file) {
- ret = -EBADF;
- goto out_put_eventfd;
- }
-
- /* the process need read permission on control file */
- /* AV: shouldn't we check that it's been opened for read instead? */
- ret = inode_permission(file_inode(cfile.file), MAY_READ);
- if (ret < 0)
- goto out_put_cfile;
-
- event->cft = __file_cft(cfile.file);
- if (IS_ERR(event->cft)) {
- ret = PTR_ERR(event->cft);
- goto out_put_cfile;
- }
-
- if (!event->cft->ss) {
- ret = -EBADF;
- goto out_put_cfile;
- }
-
- /*
- * Determine the css of @cfile, verify it belongs to the same
- * cgroup as cgroup.event_control, and associate @event with it.
- * Remaining events are automatically removed on cgroup destruction
- * but the removal is asynchronous, so take an extra ref.
- */
- rcu_read_lock();
-
- ret = -EINVAL;
- event->css = cgroup_css(cgrp, event->cft->ss);
- cfile_css = css_from_dir(cfile.file->f_dentry->d_parent, event->cft->ss);
- if (event->css && event->css == cfile_css && css_tryget(event->css))
- ret = 0;
-
- rcu_read_unlock();
- if (ret)
- goto out_put_cfile;
-
- if (!event->cft->register_event || !event->cft->unregister_event) {
- ret = -EINVAL;
- goto out_put_css;
- }
-
- ret = event->cft->register_event(event->css, event->cft,
- event->eventfd, buffer);
- if (ret)
- goto out_put_css;
-
- efile.file->f_op->poll(efile.file, &event->pt);
-
- spin_lock(&cgrp->event_list_lock);
- list_add(&event->list, &cgrp->event_list);
- spin_unlock(&cgrp->event_list_lock);
-
- fdput(cfile);
- fdput(efile);
-
- return 0;
-
-out_put_css:
- css_put(event->css);
-out_put_cfile:
- fdput(cfile);
-out_put_eventfd:
- eventfd_ctx_put(event->eventfd);
-out_put_efile:
- fdput(efile);
-out_kfree:
- kfree(event);
-
- return ret;
-}
-
static u64 cgroup_clone_children_read(struct cgroup_subsys_state *css,
struct cftype *cft)
{
@@ -4143,17 +3897,15 @@ static int cgroup_clone_children_write(struct cgroup_subsys_state *css,
static struct cftype cgroup_base_files[] = {
{
.name = "cgroup.procs",
- .open = cgroup_procs_open,
+ .seq_start = cgroup_pidlist_start,
+ .seq_next = cgroup_pidlist_next,
+ .seq_stop = cgroup_pidlist_stop,
+ .seq_show = cgroup_pidlist_show,
+ .private = CGROUP_FILE_PROCS,
.write_u64 = cgroup_procs_write,
- .release = cgroup_pidlist_release,
.mode = S_IRUGO | S_IWUSR,
},
{
- .name = "cgroup.event_control",
- .write_string = cgroup_write_event_control,
- .mode = S_IWUGO,
- },
- {
.name = "cgroup.clone_children",
.flags = CFTYPE_INSANE,
.read_u64 = cgroup_clone_children_read,
@@ -4162,7 +3914,7 @@ static struct cftype cgroup_base_files[] = {
{
.name = "cgroup.sane_behavior",
.flags = CFTYPE_ONLY_ON_ROOT,
- .read_seq_string = cgroup_sane_behavior_show,
+ .seq_show = cgroup_sane_behavior_show,
},
/*
@@ -4173,9 +3925,12 @@ static struct cftype cgroup_base_files[] = {
{
.name = "tasks",
.flags = CFTYPE_INSANE, /* use "procs" instead */
- .open = cgroup_tasks_open,
+ .seq_start = cgroup_pidlist_start,
+ .seq_next = cgroup_pidlist_next,
+ .seq_stop = cgroup_pidlist_stop,
+ .seq_show = cgroup_pidlist_show,
+ .private = CGROUP_FILE_TASKS,
.write_u64 = cgroup_tasks_write,
- .release = cgroup_pidlist_release,
.mode = S_IRUGO | S_IWUSR,
},
{
@@ -4187,7 +3942,7 @@ static struct cftype cgroup_base_files[] = {
{
.name = "release_agent",
.flags = CFTYPE_INSANE | CFTYPE_ONLY_ON_ROOT,
- .read_seq_string = cgroup_release_agent_show,
+ .seq_show = cgroup_release_agent_show,
.write_string = cgroup_release_agent_write,
.max_write_len = PATH_MAX,
},
@@ -4333,6 +4088,62 @@ static void offline_css(struct cgroup_subsys_state *css)
RCU_INIT_POINTER(css->cgroup->subsys[ss->subsys_id], css);
}
+/**
+ * create_css - create a cgroup_subsys_state
+ * @cgrp: the cgroup new css will be associated with
+ * @ss: the subsys of new css
+ *
+ * Create a new css associated with @cgrp - @ss pair. On success, the new
+ * css is online and installed in @cgrp with all interface files created.
+ * Returns 0 on success, -errno on failure.
+ */
+static int create_css(struct cgroup *cgrp, struct cgroup_subsys *ss)
+{
+ struct cgroup *parent = cgrp->parent;
+ struct cgroup_subsys_state *css;
+ int err;
+
+ lockdep_assert_held(&cgrp->dentry->d_inode->i_mutex);
+ lockdep_assert_held(&cgroup_mutex);
+
+ css = ss->css_alloc(cgroup_css(parent, ss));
+ if (IS_ERR(css))
+ return PTR_ERR(css);
+
+ err = percpu_ref_init(&css->refcnt, css_release);
+ if (err)
+ goto err_free;
+
+ init_css(css, ss, cgrp);
+
+ err = cgroup_populate_dir(cgrp, 1 << ss->subsys_id);
+ if (err)
+ goto err_free;
+
+ err = online_css(css);
+ if (err)
+ goto err_free;
+
+ dget(cgrp->dentry);
+ css_get(css->parent);
+
+ if (ss->broken_hierarchy && !ss->warned_broken_hierarchy &&
+ parent->parent) {
+ pr_warning("cgroup: %s (%d) created nested cgroup for controller \"%s\" which has incomplete hierarchy support. Nested cgroups may change behavior in the future.\n",
+ current->comm, current->pid, ss->name);
+ if (!strcmp(ss->name, "memory"))
+ pr_warning("cgroup: \"memory\" requires setting use_hierarchy to 1 on the root.\n");
+ ss->warned_broken_hierarchy = true;
+ }
+
+ return 0;
+
+err_free:
+ percpu_ref_cancel_init(&css->refcnt);
+ ss->css_free(css);
+ return err;
+}
+
/*
* cgroup_create - create a cgroup
* @parent: cgroup that will be parent of the new cgroup
@@ -4344,11 +4155,10 @@ static void offline_css(struct cgroup_subsys_state *css)
static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
umode_t mode)
{
- struct cgroup_subsys_state *css_ar[CGROUP_SUBSYS_COUNT] = { };
struct cgroup *cgrp;
struct cgroup_name *name;
struct cgroupfs_root *root = parent->root;
- int err = 0;
+ int ssid, err = 0;
struct cgroup_subsys *ss;
struct super_block *sb = root->sb;
@@ -4404,23 +4214,6 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
if (test_bit(CGRP_CPUSET_CLONE_CHILDREN, &parent->flags))
set_bit(CGRP_CPUSET_CLONE_CHILDREN, &cgrp->flags);
- for_each_root_subsys(root, ss) {
- struct cgroup_subsys_state *css;
-
- css = ss->css_alloc(cgroup_css(parent, ss));
- if (IS_ERR(css)) {
- err = PTR_ERR(css);
- goto err_free_all;
- }
- css_ar[ss->subsys_id] = css;
-
- err = percpu_ref_init(&css->refcnt, css_release);
- if (err)
- goto err_free_all;
-
- init_css(css, ss, cgrp);
- }
-
/*
* Create directory. cgroup_create_file() returns with the new
* directory locked on success so that it can be populated without
@@ -4428,7 +4221,7 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
*/
err = cgroup_create_file(dentry, S_IFDIR | mode, sb);
if (err < 0)
- goto err_free_all;
+ goto err_unlock;
lockdep_assert_held(&dentry->d_inode->i_mutex);
cgrp->serial_nr = cgroup_serial_nr_next++;
@@ -4440,55 +4233,31 @@ static long cgroup_create(struct cgroup *parent, struct dentry *dentry,
/* hold a ref to the parent's dentry */
dget(parent->dentry);
- /* creation succeeded, notify subsystems */
- for_each_root_subsys(root, ss) {
- struct cgroup_subsys_state *css = css_ar[ss->subsys_id];
-
- err = online_css(css);
- if (err)
- goto err_destroy;
-
- /* each css holds a ref to the cgroup's dentry and parent css */
- dget(dentry);
- css_get(css->parent);
-
- /* mark it consumed for error path */
- css_ar[ss->subsys_id] = NULL;
-
- if (ss->broken_hierarchy && !ss->warned_broken_hierarchy &&
- parent->parent) {
- pr_warning("cgroup: %s (%d) created nested cgroup for controller \"%s\" which has incomplete hierarchy support. Nested cgroups may change behavior in the future.\n",
- current->comm, current->pid, ss->name);
- if (!strcmp(ss->name, "memory"))
- pr_warning("cgroup: \"memory\" requires setting use_hierarchy to 1 on the root.\n");
- ss->warned_broken_hierarchy = true;
- }
- }
-
+ /*
+ * @cgrp is now fully operational. If something fails after this
+ * point, it'll be released via the normal destruction path.
+ */
idr_replace(&root->cgroup_idr, cgrp, cgrp->id);
err = cgroup_addrm_files(cgrp, cgroup_base_files, true);
if (err)
goto err_destroy;
- err = cgroup_populate_dir(cgrp, root->subsys_mask);
- if (err)
- goto err_destroy;
+ /* let's create and online css's */
+ for_each_subsys(ss, ssid) {
+ if (root->subsys_mask & (1 << ssid)) {
+ err = create_css(cgrp, ss);
+ if (err)
+ goto err_destroy;
+ }
+ }
mutex_unlock(&cgroup_mutex);
mutex_unlock(&cgrp->dentry->d_inode->i_mutex);
return 0;
-err_free_all:
- for_each_root_subsys(root, ss) {
- struct cgroup_subsys_state *css = css_ar[ss->subsys_id];
-
- if (css) {
- percpu_ref_cancel_init(&css->refcnt);
- ss->css_free(css);
- }
- }
+err_unlock:
mutex_unlock(&cgroup_mutex);
/* Release the reference count that we took on the superblock */
deactivate_super(sb);
@@ -4501,14 +4270,6 @@ err_free_cgrp:
return err;
err_destroy:
- for_each_root_subsys(root, ss) {
- struct cgroup_subsys_state *css = css_ar[ss->subsys_id];
-
- if (css) {
- percpu_ref_cancel_init(&css->refcnt);
- ss->css_free(css);
- }
- }
cgroup_destroy_locked(cgrp);
mutex_unlock(&cgroup_mutex);
mutex_unlock(&dentry->d_inode->i_mutex);
@@ -4631,10 +4392,10 @@ static int cgroup_destroy_locked(struct cgroup *cgrp)
__releases(&cgroup_mutex) __acquires(&cgroup_mutex)
{
struct dentry *d = cgrp->dentry;
- struct cgroup_event *event, *tmp;
- struct cgroup_subsys *ss;
+ struct cgroup_subsys_state *css;
struct cgroup *child;
bool empty;
+ int ssid;
lockdep_assert_held(&d->d_inode->i_mutex);
lockdep_assert_held(&cgroup_mutex);
@@ -4670,12 +4431,8 @@ static int cgroup_destroy_locked(struct cgroup *cgrp)
* will be invoked to perform the rest of destruction once the
* percpu refs of all css's are confirmed to be killed.
*/
- for_each_root_subsys(cgrp->root, ss) {
- struct cgroup_subsys_state *css = cgroup_css(cgrp, ss);
-
- if (css)
- kill_css(css);
- }
+ for_each_css(css, ssid, cgrp)
+ kill_css(css);
/*
* Mark @cgrp dead. This prevents further task migration and child
@@ -4710,18 +4467,6 @@ static int cgroup_destroy_locked(struct cgroup *cgrp)
dget(d);
cgroup_d_remove_dir(d);
- /*
- * Unregister events and notify userspace.
- * Notify userspace about cgroup removing only after rmdir of cgroup
- * directory to avoid race between userspace and kernelspace.
- */
- spin_lock(&cgrp->event_list_lock);
- list_for_each_entry_safe(event, tmp, &cgrp->event_list, list) {
- list_del_init(&event->list);
- schedule_work(&event->remove);
- }
- spin_unlock(&cgrp->event_list_lock);
-
return 0;
};
@@ -4792,7 +4537,6 @@ static void __init cgroup_init_subsys(struct cgroup_subsys *ss)
cgroup_init_cftsets(ss);
/* Create the top cgroup state for this subsystem */
- list_add(&ss->sibling, &cgroup_dummy_root.subsys_list);
ss->root = &cgroup_dummy_root;
css = ss->css_alloc(cgroup_css(cgroup_dummy_top, ss));
/* We don't handle early failures gracefully */
@@ -4866,6 +4610,7 @@ int __init_or_module cgroup_load_subsys(struct cgroup_subsys *ss)
cgroup_init_cftsets(ss);
mutex_lock(&cgroup_mutex);
+ mutex_lock(&cgroup_root_mutex);
cgroup_subsys[ss->subsys_id] = ss;
/*
@@ -4877,11 +4622,11 @@ int __init_or_module cgroup_load_subsys(struct cgroup_subsys *ss)
if (IS_ERR(css)) {
/* failure case - need to deassign the cgroup_subsys[] slot. */
cgroup_subsys[ss->subsys_id] = NULL;
+ mutex_unlock(&cgroup_root_mutex);
mutex_unlock(&cgroup_mutex);
return PTR_ERR(css);
}
- list_add(&ss->sibling, &cgroup_dummy_root.subsys_list);
ss->root = &cgroup_dummy_root;
/* our new subsystem will be attached to the dummy hierarchy. */
@@ -4911,14 +4656,18 @@ int __init_or_module cgroup_load_subsys(struct cgroup_subsys *ss)
write_unlock(&css_set_lock);
ret = online_css(css);
- if (ret)
+ if (ret) {
+ ss->css_free(css);
goto err_unload;
+ }
/* success! */
+ mutex_unlock(&cgroup_root_mutex);
mutex_unlock(&cgroup_mutex);
return 0;
err_unload:
+ mutex_unlock(&cgroup_root_mutex);
mutex_unlock(&cgroup_mutex);
/* @ss can't be mounted here as try_module_get() would fail */
cgroup_unload_subsys(ss);
@@ -4937,6 +4686,7 @@ EXPORT_SYMBOL_GPL(cgroup_load_subsys);
void cgroup_unload_subsys(struct cgroup_subsys *ss)
{
struct cgrp_cset_link *link;
+ struct cgroup_subsys_state *css;
BUG_ON(ss->module == NULL);
@@ -4948,15 +4698,15 @@ void cgroup_unload_subsys(struct cgroup_subsys *ss)
BUG_ON(ss->root != &cgroup_dummy_root);
mutex_lock(&cgroup_mutex);
+ mutex_lock(&cgroup_root_mutex);
- offline_css(cgroup_css(cgroup_dummy_top, ss));
+ css = cgroup_css(cgroup_dummy_top, ss);
+ if (css)
+ offline_css(css);
/* deassign the subsys_id */
cgroup_subsys[ss->subsys_id] = NULL;
- /* remove subsystem from the dummy root's list of subsystems */
- list_del_init(&ss->sibling);
-
/*
* disentangle the css from all css_sets attached to the dummy
* top. as in loading, we need to pay our respects to the hashtable
@@ -4979,9 +4729,11 @@ void cgroup_unload_subsys(struct cgroup_subsys *ss)
* need to free before marking as null because ss->css_free needs
* the cgrp->subsys pointer to find their state.
*/
- ss->css_free(cgroup_css(cgroup_dummy_top, ss));
+ if (css)
+ ss->css_free(css);
RCU_INIT_POINTER(cgroup_dummy_top->subsys[ss->subsys_id], NULL);
+ mutex_unlock(&cgroup_root_mutex);
mutex_unlock(&cgroup_mutex);
}
EXPORT_SYMBOL_GPL(cgroup_unload_subsys);
@@ -5100,6 +4852,15 @@ static int __init cgroup_wq_init(void)
*/
cgroup_destroy_wq = alloc_workqueue("cgroup_destroy", 0, 1);
BUG_ON(!cgroup_destroy_wq);
+
+ /*
+ * Used to destroy pidlists and separate to serve as flush domain.
+ * Cap @max_active to 1 too.
+ */
+ cgroup_pidlist_destroy_wq = alloc_workqueue("cgroup_pidlist_destroy",
+ 0, 1);
+ BUG_ON(!cgroup_pidlist_destroy_wq);
+
return 0;
}
core_initcall(cgroup_wq_init);
@@ -5143,11 +4904,12 @@ int proc_cgroup_show(struct seq_file *m, void *v)
for_each_active_root(root) {
struct cgroup_subsys *ss;
struct cgroup *cgrp;
- int count = 0;
+ int ssid, count = 0;
seq_printf(m, "%d:", root->hierarchy_id);
- for_each_root_subsys(root, ss)
- seq_printf(m, "%s%s", count++ ? "," : "", ss->name);
+ for_each_subsys(ss, ssid)
+ if (root->subsys_mask & (1 << ssid))
+ seq_printf(m, "%s%s", count++ ? "," : "", ss->name);
if (strlen(root->name))
seq_printf(m, "%sname=%s", count ? "," : "",
root->name);
@@ -5488,16 +5250,16 @@ __setup("cgroup_disable=", cgroup_disable);
* @dentry: directory dentry of interest
* @ss: subsystem of interest
*
- * Must be called under RCU read lock. The caller is responsible for
- * pinning the returned css if it needs to be accessed outside the RCU
- * critical section.
+ * Must be called under cgroup_mutex or RCU read lock. The caller is
+ * responsible for pinning the returned css if it needs to be accessed
+ * outside the critical section.
*/
struct cgroup_subsys_state *css_from_dir(struct dentry *dentry,
struct cgroup_subsys *ss)
{
struct cgroup *cgrp;
- WARN_ON_ONCE(!rcu_read_lock_held());
+ cgroup_assert_mutex_or_rcu_locked();
/* is @dentry a cgroup dir? */
if (!dentry->d_inode ||
@@ -5520,9 +5282,7 @@ struct cgroup_subsys_state *css_from_id(int id, struct cgroup_subsys *ss)
{
struct cgroup *cgrp;
- rcu_lockdep_assert(rcu_read_lock_held() ||
- lockdep_is_held(&cgroup_mutex),
- "css_from_id() needs proper protection");
+ cgroup_assert_mutex_or_rcu_locked();
cgrp = idr_find(&ss->root->cgroup_idr, id);
if (cgrp)
@@ -5570,9 +5330,7 @@ static u64 current_css_set_refcount_read(struct cgroup_subsys_state *css,
return count;
}
-static int current_css_set_cg_links_read(struct cgroup_subsys_state *css,
- struct cftype *cft,
- struct seq_file *seq)
+static int current_css_set_cg_links_read(struct seq_file *seq, void *v)
{
struct cgrp_cset_link *link;
struct css_set *cset;
@@ -5597,9 +5355,9 @@ static int current_css_set_cg_links_read(struct cgroup_subsys_state *css,
}
#define MAX_TASKS_SHOWN_PER_CSS 25
-static int cgroup_css_links_read(struct cgroup_subsys_state *css,
- struct cftype *cft, struct seq_file *seq)
+static int cgroup_css_links_read(struct seq_file *seq, void *v)
{
+ struct cgroup_subsys_state *css = seq_css(seq);
struct cgrp_cset_link *link;
read_lock(&css_set_lock);
@@ -5645,12 +5403,12 @@ static struct cftype debug_files[] = {
{
.name = "current_css_set_cg_links",
- .read_seq_string = current_css_set_cg_links_read,
+ .seq_show = current_css_set_cg_links_read,
},
{
.name = "cgroup_css_links",
- .read_seq_string = cgroup_css_links_read,
+ .seq_show = cgroup_css_links_read,
},
{
diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c
index f0ff64d0ebaa..6c3154e477f6 100644
--- a/kernel/cgroup_freezer.c
+++ b/kernel/cgroup_freezer.c
@@ -301,10 +301,9 @@ out_unlock:
spin_unlock_irq(&freezer->lock);
}
-static int freezer_read(struct cgroup_subsys_state *css, struct cftype *cft,
- struct seq_file *m)
+static int freezer_read(struct seq_file *m, void *v)
{
- struct cgroup_subsys_state *pos;
+ struct cgroup_subsys_state *css = seq_css(m), *pos;
rcu_read_lock();
@@ -458,7 +457,7 @@ static struct cftype files[] = {
{
.name = "state",
.flags = CFTYPE_NOT_ON_ROOT,
- .read_seq_string = freezer_read,
+ .seq_show = freezer_read,
.write_string = freezer_write,
},
{
diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 4772034b4b17..4410ac6a55f1 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -1731,66 +1731,41 @@ out_unlock:
* used, list of ranges of sequential numbers, is variable length,
* and since these maps can change value dynamically, one could read
* gibberish by doing partial reads while a list was changing.
- * A single large read to a buffer that crosses a page boundary is
- * ok, because the result being copied to user land is not recomputed
- * across a page fault.
*/
-
-static size_t cpuset_sprintf_cpulist(char *page, struct cpuset *cs)
+static int cpuset_common_seq_show(struct seq_file *sf, void *v)
{
- size_t count;
-
- mutex_lock(&callback_mutex);
- count = cpulist_scnprintf(page, PAGE_SIZE, cs->cpus_allowed);
- mutex_unlock(&callback_mutex);
+ struct cpuset *cs = css_cs(seq_css(sf));
+ cpuset_filetype_t type = seq_cft(sf)->private;
+ ssize_t count;
+ char *buf, *s;
+ int ret = 0;
- return count;
-}
-
-static size_t cpuset_sprintf_memlist(char *page, struct cpuset *cs)
-{
- size_t count;
+ count = seq_get_buf(sf, &buf);
+ s = buf;
mutex_lock(&callback_mutex);
- count = nodelist_scnprintf(page, PAGE_SIZE, cs->mems_allowed);
- mutex_unlock(&callback_mutex);
-
- return count;
-}
-
-static ssize_t cpuset_common_file_read(struct cgroup_subsys_state *css,
- struct cftype *cft, struct file *file,
- char __user *buf, size_t nbytes,
- loff_t *ppos)
-{
- struct cpuset *cs = css_cs(css);
- cpuset_filetype_t type = cft->private;
- char *page;
- ssize_t retval = 0;
- char *s;
-
- if (!(page = (char *)__get_free_page(GFP_TEMPORARY)))
- return -ENOMEM;
-
- s = page;
switch (type) {
case FILE_CPULIST:
- s += cpuset_sprintf_cpulist(s, cs);
+ s += cpulist_scnprintf(s, count, cs->cpus_allowed);
break;
case FILE_MEMLIST:
- s += cpuset_sprintf_memlist(s, cs);
+ s += nodelist_scnprintf(s, count, cs->mems_allowed);
break;
default:
- retval = -EINVAL;
- goto out;
+ ret = -EINVAL;
+ goto out_unlock;
}
- *s++ = '\n';
- retval = simple_read_from_buffer(buf, nbytes, ppos, page, s - page);
-out:
- free_page((unsigned long)page);
- return retval;
+ if (s < buf + count - 1) {
+ *s++ = '\n';
+ seq_commit(sf, s - buf);
+ } else {
+ seq_commit(sf, -1);
+ }
+out_unlock:
+ mutex_unlock(&callback_mutex);
+ return ret;
}
static u64 cpuset_read_u64(struct cgroup_subsys_state *css, struct cftype *cft)
@@ -1847,7 +1822,7 @@ static s64 cpuset_read_s64(struct cgroup_subsys_state *css, struct cftype *cft)
static struct cftype files[] = {
{
.name = "cpus",
- .read = cpuset_common_file_read,
+ .seq_show = cpuset_common_seq_show,
.write_string = cpuset_write_resmask,
.max_write_len = (100U + 6 * NR_CPUS),
.private = FILE_CPULIST,
@@ -1855,7 +1830,7 @@ static struct cftype files[] = {
{
.name = "mems",
- .read = cpuset_common_file_read,
+ .seq_show = cpuset_common_seq_show,
.write_string = cpuset_write_resmask,
.max_write_len = (100U + 6 * MAX_NUMNODES),
.private = FILE_MEMLIST,
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 36c951b7eef8..3897e09e86a2 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -7852,15 +7852,14 @@ static int __cfs_schedulable(struct task_group *tg, u64 period, u64 quota)
return ret;
}
-static int cpu_stats_show(struct cgroup_subsys_state *css, struct cftype *cft,
- struct cgroup_map_cb *cb)
+static int cpu_stats_show(struct seq_file *sf, void *v)
{
- struct task_group *tg = css_tg(css);
+ struct task_group *tg = css_tg(seq_css(sf));
struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth;
- cb->fill(cb, "nr_periods", cfs_b->nr_periods);
- cb->fill(cb, "nr_throttled", cfs_b->nr_throttled);
- cb->fill(cb, "throttled_time", cfs_b->throttled_time);
+ seq_printf(sf, "nr_periods %d\n", cfs_b->nr_periods);
+ seq_printf(sf, "nr_throttled %d\n", cfs_b->nr_throttled);
+ seq_printf(sf, "throttled_time %llu\n", cfs_b->throttled_time);
return 0;
}
@@ -7914,7 +7913,7 @@ static struct cftype cpu_files[] = {
},
{
.name = "stat",
- .read_map = cpu_stats_show,
+ .seq_show = cpu_stats_show,
},
#endif
#ifdef CONFIG_RT_GROUP_SCHED
diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c
index f64722ff0299..622e0818f905 100644
--- a/kernel/sched/cpuacct.c
+++ b/kernel/sched/cpuacct.c
@@ -163,10 +163,9 @@ out:
return err;
}
-static int cpuacct_percpu_seq_read(struct cgroup_subsys_state *css,
- struct cftype *cft, struct seq_file *m)
+static int cpuacct_percpu_seq_show(struct seq_file *m, void *V)
{
- struct cpuacct *ca = css_ca(css);
+ struct cpuacct *ca = css_ca(seq_css(m));
u64 percpu;
int i;
@@ -183,10 +182,9 @@ static const char * const cpuacct_stat_desc[] = {
[CPUACCT_STAT_SYSTEM] = "system",
};
-static int cpuacct_stats_show(struct cgroup_subsys_state *css,
- struct cftype *cft, struct cgroup_map_cb *cb)
+static int cpuacct_stats_show(struct seq_file *sf, void *v)
{
- struct cpuacct *ca = css_ca(css);
+ struct cpuacct *ca = css_ca(seq_css(sf));
int cpu;
s64 val = 0;
@@ -196,7 +194,7 @@ static int cpuacct_stats_show(struct cgroup_subsys_state *css,
val += kcpustat->cpustat[CPUTIME_NICE];
}
val = cputime64_to_clock_t(val);
- cb->fill(cb, cpuacct_stat_desc[CPUACCT_STAT_USER], val);
+ seq_printf(sf, "%s %lld\n", cpuacct_stat_desc[CPUACCT_STAT_USER], val);
val = 0;
for_each_online_cpu(cpu) {
@@ -207,7 +205,7 @@ static int cpuacct_stats_show(struct cgroup_subsys_state *css,
}
val = cputime64_to_clock_t(val);
- cb->fill(cb, cpuacct_stat_desc[CPUACCT_STAT_SYSTEM], val);
+ seq_printf(sf, "%s %lld\n", cpuacct_stat_desc[CPUACCT_STAT_SYSTEM], val);
return 0;
}
@@ -220,11 +218,11 @@ static struct cftype files[] = {
},
{
.name = "usage_percpu",
- .read_seq_string = cpuacct_percpu_seq_read,
+ .seq_show = cpuacct_percpu_seq_show,
},
{
.name = "stat",
- .read_map = cpuacct_stats_show,
+ .seq_show = cpuacct_stats_show,
},
{ } /* terminate */
};
diff --git a/mm/hugetlb_cgroup.c b/mm/hugetlb_cgroup.c
index bda8e44f6fde..d747a84e09b0 100644
--- a/mm/hugetlb_cgroup.c
+++ b/mm/hugetlb_cgroup.c
@@ -242,22 +242,16 @@ void hugetlb_cgroup_uncharge_cgroup(int idx, unsigned long nr_pages,
return;
}
-static ssize_t hugetlb_cgroup_read(struct cgroup_subsys_state *css,
- struct cftype *cft, struct file *file,
- char __user *buf, size_t nbytes,
- loff_t *ppos)
+static u64 hugetlb_cgroup_read_u64(struct cgroup_subsys_state *css,
+ struct cftype *cft)
{
- u64 val;
- char str[64];
- int idx, name, len;
+ int idx, name;
struct hugetlb_cgroup *h_cg = hugetlb_cgroup_from_css(css);
idx = MEMFILE_IDX(cft->private);
name = MEMFILE_ATTR(cft->private);
- val = res_counter_read_u64(&h_cg->hugepage[idx], name);
- len = scnprintf(str, sizeof(str), "%llu\n", (unsigned long long)val);
- return simple_read_from_buffer(buf, nbytes, ppos, str, len);
+ return res_counter_read_u64(&h_cg->hugepage[idx], name);
}
static int hugetlb_cgroup_write(struct cgroup_subsys_state *css,
@@ -337,28 +331,28 @@ static void __init __hugetlb_cgroup_file_init(int idx)
cft = &h->cgroup_files[0];
snprintf(cft->name, MAX_CFTYPE_NAME, "%s.limit_in_bytes", buf);
cft->private = MEMFILE_PRIVATE(idx, RES_LIMIT);
- cft->read = hugetlb_cgroup_read;
+ cft->read_u64 = hugetlb_cgroup_read_u64;
cft->write_string = hugetlb_cgroup_write;
/* Add the usage file */
cft = &h->cgroup_files[1];
snprintf(cft->name, MAX_CFTYPE_NAME, "%s.usage_in_bytes", buf);
cft->private = MEMFILE_PRIVATE(idx, RES_USAGE);
- cft->read = hugetlb_cgroup_read;
+ cft->read_u64 = hugetlb_cgroup_read_u64;
/* Add the MAX usage file */
cft = &h->cgroup_files[2];
snprintf(cft->name, MAX_CFTYPE_NAME, "%s.max_usage_in_bytes", buf);
cft->private = MEMFILE_PRIVATE(idx, RES_MAX_USAGE);
cft->trigger = hugetlb_cgroup_reset;
- cft->read = hugetlb_cgroup_read;
+ cft->read_u64 = hugetlb_cgroup_read_u64;
/* Add the failcntfile */
cft = &h->cgroup_files[3];
snprintf(cft->name, MAX_CFTYPE_NAME, "%s.failcnt", buf);
cft->private = MEMFILE_PRIVATE(idx, RES_FAILCNT);
cft->trigger = hugetlb_cgroup_reset;
- cft->read = hugetlb_cgroup_read;
+ cft->read_u64 = hugetlb_cgroup_read_u64;
/* NULL terminate the last cft */
cft = &h->cgroup_files[4];
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 7f1a356153c0..7caff36180cd 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -45,6 +45,7 @@
#include <linux/swapops.h>
#include <linux/spinlock.h>
#include <linux/eventfd.h>
+#include <linux/poll.h>
#include <linux/sort.h>
#include <linux/fs.h>
#include <linux/seq_file.h>
@@ -55,6 +56,7 @@
#include <linux/cpu.h>
#include <linux/oom.h>
#include <linux/lockdep.h>
+#include <linux/file.h>
#include "internal.h"
#include <net/sock.h>
#include <net/ip.h>
@@ -227,6 +229,46 @@ struct mem_cgroup_eventfd_list {
struct eventfd_ctx *eventfd;
};
+/*
+ * cgroup_event represents events which userspace want to receive.
+ */
+struct mem_cgroup_event {
+ /*
+ * memcg which the event belongs to.
+ */
+ struct mem_cgroup *memcg;
+ /*
+ * eventfd to signal userspace about the event.
+ */
+ struct eventfd_ctx *eventfd;
+ /*
+ * Each of these stored in a list by the cgroup.
+ */
+ struct list_head list;
+ /*
+ * register_event() callback will be used to add new userspace
+ * waiter for changes related to this event. Use eventfd_signal()
+ * on eventfd to send notification to userspace.
+ */
+ int (*register_event)(struct mem_cgroup *memcg,
+ struct eventfd_ctx *eventfd, const char *args);
+ /*
+ * unregister_event() callback will be called when userspace closes
+ * the eventfd or on cgroup removing. This callback must be set,
+ * if you want provide notification functionality.
+ */
+ void (*unregister_event)(struct mem_cgroup *memcg,
+ struct eventfd_ctx *eventfd);
+ /*
+ * All fields below needed to unregister event when
+ * userspace closes eventfd.
+ */
+ poll_table pt;
+ wait_queue_head_t *wqh;
+ wait_queue_t wait;
+ struct work_struct remove;
+};
+
static void mem_cgroup_threshold(struct mem_cgroup *memcg);
static void mem_cgroup_oom_notify(struct mem_cgroup *memcg);
@@ -331,6 +373,10 @@ struct mem_cgroup {
atomic_t numainfo_updating;
#endif
+ /* List of events which userspace want to receive */
+ struct list_head event_list;
+ spinlock_t event_list_lock;
+
struct mem_cgroup_per_node *nodeinfo[0];
/* WARNING: nodeinfo must be the last member here */
};
@@ -490,11 +536,6 @@ struct cgroup_subsys_state *vmpressure_to_css(struct vmpressure *vmpr)
return &container_of(vmpr, struct mem_cgroup, vmpressure)->css;
}
-struct vmpressure *css_to_vmpressure(struct cgroup_subsys_state *css)
-{
- return &mem_cgroup_from_css(css)->vmpressure;
-}
-
static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg)
{
return (memcg == root_mem_cgroup);
@@ -2976,10 +3017,9 @@ static struct kmem_cache *memcg_params_to_cache(struct memcg_cache_params *p)
}
#ifdef CONFIG_SLABINFO
-static int mem_cgroup_slabinfo_read(struct cgroup_subsys_state *css,
- struct cftype *cft, struct seq_file *m)
+static int mem_cgroup_slabinfo_read(struct seq_file *m, void *v)
{
- struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+ struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
struct memcg_cache_params *params;
if (!memcg_can_account_kmem(memcg))
@@ -5112,14 +5152,12 @@ static inline u64 mem_cgroup_usage(struct mem_cgroup *memcg, bool swap)
return val << PAGE_SHIFT;
}
-static ssize_t mem_cgroup_read(struct cgroup_subsys_state *css,
- struct cftype *cft, struct file *file,
- char __user *buf, size_t nbytes, loff_t *ppos)
+static u64 mem_cgroup_read_u64(struct cgroup_subsys_state *css,
+ struct cftype *cft)
{
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
- char str[64];
u64 val;
- int name, len;
+ int name;
enum res_type type;
type = MEMFILE_TYPE(cft->private);
@@ -5145,8 +5183,7 @@ static ssize_t mem_cgroup_read(struct cgroup_subsys_state *css,
BUG();
}
- len = scnprintf(str, sizeof(str), "%llu\n", (unsigned long long)val);
- return simple_read_from_buffer(buf, nbytes, ppos, str, len);
+ return val;
}
static int memcg_update_kmem_limit(struct cgroup_subsys_state *css, u64 val)
@@ -5383,8 +5420,7 @@ static int mem_cgroup_move_charge_write(struct cgroup_subsys_state *css,
#endif
#ifdef CONFIG_NUMA
-static int memcg_numa_stat_show(struct cgroup_subsys_state *css,
- struct cftype *cft, struct seq_file *m)
+static int memcg_numa_stat_show(struct seq_file *m, void *v)
{
struct numa_stat {
const char *name;
@@ -5400,7 +5436,7 @@ static int memcg_numa_stat_show(struct cgroup_subsys_state *css,
const struct numa_stat *stat;
int nid;
unsigned long nr;
- struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+ struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
for (stat = stats; stat < stats + ARRAY_SIZE(stats); stat++) {
nr = mem_cgroup_nr_lru_pages(memcg, stat->lru_mask);
@@ -5439,10 +5475,9 @@ static inline void mem_cgroup_lru_names_not_uptodate(void)
BUILD_BUG_ON(ARRAY_SIZE(mem_cgroup_lru_names) != NR_LRU_LISTS);
}
-static int memcg_stat_show(struct cgroup_subsys_state *css, struct cftype *cft,
- struct seq_file *m)
+static int memcg_stat_show(struct seq_file *m, void *v)
{
- struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+ struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(m));
struct mem_cgroup *mi;
unsigned int i;
@@ -5651,13 +5686,11 @@ static void mem_cgroup_oom_notify(struct mem_cgroup *memcg)
mem_cgroup_oom_notify_cb(iter);
}
-static int mem_cgroup_usage_register_event(struct cgroup_subsys_state *css,
- struct cftype *cft, struct eventfd_ctx *eventfd, const char *args)
+static int __mem_cgroup_usage_register_event(struct mem_cgroup *memcg,
+ struct eventfd_ctx *eventfd, const char *args, enum res_type type)
{
- struct mem_cgroup *memcg = mem_cgroup_from_css(css);
struct mem_cgroup_thresholds *thresholds;
struct mem_cgroup_threshold_ary *new;
- enum res_type type = MEMFILE_TYPE(cft->private);
u64 threshold, usage;
int i, size, ret;
@@ -5734,13 +5767,23 @@ unlock:
return ret;
}
-static void mem_cgroup_usage_unregister_event(struct cgroup_subsys_state *css,
- struct cftype *cft, struct eventfd_ctx *eventfd)
+static int mem_cgroup_usage_register_event(struct mem_cgroup *memcg,
+ struct eventfd_ctx *eventfd, const char *args)
+{
+ return __mem_cgroup_usage_register_event(memcg, eventfd, args, _MEM);
+}
+
+static int memsw_cgroup_usage_register_event(struct mem_cgroup *memcg,
+ struct eventfd_ctx *eventfd, const char *args)
+{
+ return __mem_cgroup_usage_register_event(memcg, eventfd, args, _MEMSWAP);
+}
+
+static void __mem_cgroup_usage_unregister_event(struct mem_cgroup *memcg,
+ struct eventfd_ctx *eventfd, enum res_type type)
{
- struct mem_cgroup *memcg = mem_cgroup_from_css(css);
struct mem_cgroup_thresholds *thresholds;
struct mem_cgroup_threshold_ary *new;
- enum res_type type = MEMFILE_TYPE(cft->private);
u64 usage;
int i, j, size;
@@ -5813,14 +5856,23 @@ unlock:
mutex_unlock(&memcg->thresholds_lock);
}
-static int mem_cgroup_oom_register_event(struct cgroup_subsys_state *css,
- struct cftype *cft, struct eventfd_ctx *eventfd, const char *args)
+static void mem_cgroup_usage_unregister_event(struct mem_cgroup *memcg,
+ struct eventfd_ctx *eventfd)
+{
+ return __mem_cgroup_usage_unregister_event(memcg, eventfd, _MEM);
+}
+
+static void memsw_cgroup_usage_unregister_event(struct mem_cgroup *memcg,
+ struct eventfd_ctx *eventfd)
+{
+ return __mem_cgroup_usage_unregister_event(memcg, eventfd, _MEMSWAP);
+}
+
+static int mem_cgroup_oom_register_event(struct mem_cgroup *memcg,
+ struct eventfd_ctx *eventfd, const char *args)
{
- struct mem_cgroup *memcg = mem_cgroup_from_css(css);
struct mem_cgroup_eventfd_list *event;
- enum res_type type = MEMFILE_TYPE(cft->private);
- BUG_ON(type != _OOM_TYPE);
event = kmalloc(sizeof(*event), GFP_KERNEL);
if (!event)
return -ENOMEM;
@@ -5838,14 +5890,10 @@ static int mem_cgroup_oom_register_event(struct cgroup_subsys_state *css,
return 0;
}
-static void mem_cgroup_oom_unregister_event(struct cgroup_subsys_state *css,
- struct cftype *cft, struct eventfd_ctx *eventfd)
+static void mem_cgroup_oom_unregister_event(struct mem_cgroup *memcg,
+ struct eventfd_ctx *eventfd)
{
- struct mem_cgroup *memcg = mem_cgroup_from_css(css);
struct mem_cgroup_eventfd_list *ev, *tmp;
- enum res_type type = MEMFILE_TYPE(cft->private);
-
- BUG_ON(type != _OOM_TYPE);
spin_lock(&memcg_oom_lock);
@@ -5859,17 +5907,12 @@ static void mem_cgroup_oom_unregister_event(struct cgroup_subsys_state *css,
spin_unlock(&memcg_oom_lock);
}
-static int mem_cgroup_oom_control_read(struct cgroup_subsys_state *css,
- struct cftype *cft, struct cgroup_map_cb *cb)
+static int mem_cgroup_oom_control_read(struct seq_file *sf, void *v)
{
- struct mem_cgroup *memcg = mem_cgroup_from_css(css);
-
- cb->fill(cb, "oom_kill_disable", memcg->oom_kill_disable);
+ struct mem_cgroup *memcg = mem_cgroup_from_css(seq_css(sf));
- if (atomic_read(&memcg->under_oom))
- cb->fill(cb, "under_oom", 1);
- else
- cb->fill(cb, "under_oom", 0);
+ seq_printf(sf, "oom_kill_disable %d\n", memcg->oom_kill_disable);
+ seq_printf(sf, "under_oom %d\n", (bool)atomic_read(&memcg->under_oom));
return 0;
}
@@ -5962,41 +6005,261 @@ static void kmem_cgroup_css_offline(struct mem_cgroup *memcg)
}
#endif
+/*
+ * DO NOT USE IN NEW FILES.
+ *
+ * "cgroup.event_control" implementation.
+ *
+ * This is way over-engineered. It tries to support fully configurable
+ * events for each user. Such level of flexibility is completely
+ * unnecessary especially in the light of the planned unified hierarchy.
+ *
+ * Please deprecate this and replace with something simpler if at all
+ * possible.
+ */
+
+/*
+ * Unregister event and free resources.
+ *
+ * Gets called from workqueue.
+ */
+static void memcg_event_remove(struct work_struct *work)
+{
+ struct mem_cgroup_event *event =
+ container_of(work, struct mem_cgroup_event, remove);
+ struct mem_cgroup *memcg = event->memcg;
+
+ remove_wait_queue(event->wqh, &event->wait);
+
+ event->unregister_event(memcg, event->eventfd);
+
+ /* Notify userspace the event is going away. */
+ eventfd_signal(event->eventfd, 1);
+
+ eventfd_ctx_put(event->eventfd);
+ kfree(event);
+ css_put(&memcg->css);
+}
+
+/*
+ * Gets called on POLLHUP on eventfd when user closes it.
+ *
+ * Called with wqh->lock held and interrupts disabled.
+ */
+static int memcg_event_wake(wait_queue_t *wait, unsigned mode,
+ int sync, void *key)
+{
+ struct mem_cgroup_event *event =
+ container_of(wait, struct mem_cgroup_event, wait);
+ struct mem_cgroup *memcg = event->memcg;
+ unsigned long flags = (unsigned long)key;
+
+ if (flags & POLLHUP) {
+ /*
+ * If the event has been detached at cgroup removal, we
+ * can simply return knowing the other side will cleanup
+ * for us.
+ *
+ * We can't race against event freeing since the other
+ * side will require wqh->lock via remove_wait_queue(),
+ * which we hold.
+ */
+ spin_lock(&memcg->event_list_lock);
+ if (!list_empty(&event->list)) {
+ list_del_init(&event->list);
+ /*
+ * We are in atomic context, but cgroup_event_remove()
+ * may sleep, so we have to call it in workqueue.
+ */
+ schedule_work(&event->remove);
+ }
+ spin_unlock(&memcg->event_list_lock);
+ }
+
+ return 0;
+}
+
+static void memcg_event_ptable_queue_proc(struct file *file,
+ wait_queue_head_t *wqh, poll_table *pt)
+{
+ struct mem_cgroup_event *event =
+ container_of(pt, struct mem_cgroup_event, pt);
+
+ event->wqh = wqh;
+ add_wait_queue(wqh, &event->wait);
+}
+
+/*
+ * DO NOT USE IN NEW FILES.
+ *
+ * Parse input and register new cgroup event handler.
+ *
+ * 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, const char *buffer)
+{
+ struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+ struct mem_cgroup_event *event;
+ struct cgroup_subsys_state *cfile_css;
+ unsigned int efd, cfd;
+ struct fd efile;
+ struct fd cfile;
+ const char *name;
+ char *endp;
+ int ret;
+
+ efd = simple_strtoul(buffer, &endp, 10);
+ if (*endp != ' ')
+ return -EINVAL;
+ buffer = endp + 1;
+
+ cfd = simple_strtoul(buffer, &endp, 10);
+ if ((*endp != ' ') && (*endp != '\0'))
+ return -EINVAL;
+ buffer = endp + 1;
+
+ event = kzalloc(sizeof(*event), GFP_KERNEL);
+ if (!event)
+ return -ENOMEM;
+
+ event->memcg = memcg;
+ INIT_LIST_HEAD(&event->list);
+ init_poll_funcptr(&event->pt, memcg_event_ptable_queue_proc);
+ init_waitqueue_func_entry(&event->wait, memcg_event_wake);
+ INIT_WORK(&event->remove, memcg_event_remove);
+
+ efile = fdget(efd);
+ if (!efile.file) {
+ ret = -EBADF;
+ goto out_kfree;
+ }
+
+ event->eventfd = eventfd_ctx_fileget(efile.file);
+ if (IS_ERR(event->eventfd)) {
+ ret = PTR_ERR(event->eventfd);
+ goto out_put_efile;
+ }
+
+ cfile = fdget(cfd);
+ if (!cfile.file) {
+ ret = -EBADF;
+ goto out_put_eventfd;
+ }
+
+ /* the process need read permission on control file */
+ /* AV: shouldn't we check that it's been opened for read instead? */
+ ret = inode_permission(file_inode(cfile.file), MAY_READ);
+ if (ret < 0)
+ goto out_put_cfile;
+
+ /*
+ * Determine the event callbacks and set them in @event. This used
+ * to be done via struct cftype but cgroup core no longer knows
+ * about these events. The following is crude but the whole thing
+ * is for compatibility anyway.
+ *
+ * DO NOT ADD NEW FILES.
+ */
+ name = cfile.file->f_dentry->d_name.name;
+
+ if (!strcmp(name, "memory.usage_in_bytes")) {
+ event->register_event = mem_cgroup_usage_register_event;
+ event->unregister_event = mem_cgroup_usage_unregister_event;
+ } else if (!strcmp(name, "memory.oom_control")) {
+ event->register_event = mem_cgroup_oom_register_event;
+ event->unregister_event = mem_cgroup_oom_unregister_event;
+ } else if (!strcmp(name, "memory.pressure_level")) {
+ event->register_event = vmpressure_register_event;
+ event->unregister_event = vmpressure_unregister_event;
+ } else if (!strcmp(name, "memory.memsw.usage_in_bytes")) {
+ event->register_event = memsw_cgroup_usage_register_event;
+ event->unregister_event = memsw_cgroup_usage_unregister_event;
+ } else {
+ ret = -EINVAL;
+ goto out_put_cfile;
+ }
+
+ /*
+ * Verify @cfile should belong to @css. Also, remaining events are
+ * automatically removed on cgroup destruction but the removal is
+ * asynchronous, so take an extra ref on @css.
+ */
+ rcu_read_lock();
+
+ ret = -EINVAL;
+ cfile_css = css_from_dir(cfile.file->f_dentry->d_parent,
+ &mem_cgroup_subsys);
+ if (cfile_css == css && css_tryget(css))
+ ret = 0;
+
+ rcu_read_unlock();
+ if (ret)
+ goto out_put_cfile;
+
+ ret = event->register_event(memcg, event->eventfd, buffer);
+ if (ret)
+ goto out_put_css;
+
+ efile.file->f_op->poll(efile.file, &event->pt);
+
+ spin_lock(&memcg->event_list_lock);
+ list_add(&event->list, &memcg->event_list);
+ spin_unlock(&memcg->event_list_lock);
+
+ fdput(cfile);
+ fdput(efile);
+
+ return 0;
+
+out_put_css:
+ css_put(css);
+out_put_cfile:
+ fdput(cfile);
+out_put_eventfd:
+ eventfd_ctx_put(event->eventfd);
+out_put_efile:
+ fdput(efile);
+out_kfree:
+ kfree(event);
+
+ return ret;
+}
+
static struct cftype mem_cgroup_files[] = {
{
.name = "usage_in_bytes",
.private = MEMFILE_PRIVATE(_MEM, RES_USAGE),
- .read = mem_cgroup_read,
- .register_event = mem_cgroup_usage_register_event,
- .unregister_event = mem_cgroup_usage_unregister_event,
+ .read_u64 = mem_cgroup_read_u64,
},
{
.name = "max_usage_in_bytes",
.private = MEMFILE_PRIVATE(_MEM, RES_MAX_USAGE),
.trigger = mem_cgroup_reset,
- .read = mem_cgroup_read,
+ .read_u64 = mem_cgroup_read_u64,
},
{
.name = "limit_in_bytes",
.private = MEMFILE_PRIVATE(_MEM, RES_LIMIT),
.write_string = mem_cgroup_write,
- .read = mem_cgroup_read,
+ .read_u64 = mem_cgroup_read_u64,
},
{
.name = "soft_limit_in_bytes",
.private = MEMFILE_PRIVATE(_MEM, RES_SOFT_LIMIT),
.write_string = mem_cgroup_write,
- .read = mem_cgroup_read,
+ .read_u64 = mem_cgroup_read_u64,
},
{
.name = "failcnt",
.private = MEMFILE_PRIVATE(_MEM, RES_FAILCNT),
.trigger = mem_cgroup_reset,
- .read = mem_cgroup_read,
+ .read_u64 = mem_cgroup_read_u64,
},
{
.name = "stat",
- .read_seq_string = memcg_stat_show,
+ .seq_show = memcg_stat_show,
},
{
.name = "force_empty",
@@ -6009,6 +6272,12 @@ static struct cftype mem_cgroup_files[] = {
.read_u64 = mem_cgroup_hierarchy_read,
},
{
+ .name = "cgroup.event_control", /* XXX: for compat */
+ .write_string = memcg_write_event_control,
+ .flags = CFTYPE_NO_PREFIX,
+ .mode = S_IWUGO,
+ },
+ {
.name = "swappiness",
.read_u64 = mem_cgroup_swappiness_read,
.write_u64 = mem_cgroup_swappiness_write,
@@ -6020,21 +6289,17 @@ static struct cftype mem_cgroup_files[] = {
},
{
.name = "oom_control",
- .read_map = mem_cgroup_oom_control_read,
+ .seq_show = mem_cgroup_oom_control_read,
.write_u64 = mem_cgroup_oom_control_write,
- .register_event = mem_cgroup_oom_register_event,
- .unregister_event = mem_cgroup_oom_unregister_event,
.private = MEMFILE_PRIVATE(_OOM_TYPE, OOM_CONTROL),
},
{
.name = "pressure_level",
- .register_event = vmpressure_register_event,
- .unregister_event = vmpressure_unregister_event,
},
#ifdef CONFIG_NUMA
{
.name = "numa_stat",
- .read_seq_string = memcg_numa_stat_show,
+ .seq_show = memcg_numa_stat_show,
},
#endif
#ifdef CONFIG_MEMCG_KMEM
@@ -6042,29 +6307,29 @@ static struct cftype mem_cgroup_files[] = {
.name = "kmem.limit_in_bytes",
.private = MEMFILE_PRIVATE(_KMEM, RES_LIMIT),
.write_string = mem_cgroup_write,
- .read = mem_cgroup_read,
+ .read_u64 = mem_cgroup_read_u64,
},
{
.name = "kmem.usage_in_bytes",
.private = MEMFILE_PRIVATE(_KMEM, RES_USAGE),
- .read = mem_cgroup_read,
+ .read_u64 = mem_cgroup_read_u64,
},
{
.name = "kmem.failcnt",
.private = MEMFILE_PRIVATE(_KMEM, RES_FAILCNT),
.trigger = mem_cgroup_reset,
- .read = mem_cgroup_read,
+ .read_u64 = mem_cgroup_read_u64,
},
{
.name = "kmem.max_usage_in_bytes",
.private = MEMFILE_PRIVATE(_KMEM, RES_MAX_USAGE),
.trigger = mem_cgroup_reset,
- .read = mem_cgroup_read,
+ .read_u64 = mem_cgroup_read_u64,
},
#ifdef CONFIG_SLABINFO
{
.name = "kmem.slabinfo",
- .read_seq_string = mem_cgroup_slabinfo_read,
+ .seq_show = mem_cgroup_slabinfo_read,
},
#endif
#endif
@@ -6076,27 +6341,25 @@ static struct cftype memsw_cgroup_files[] = {
{
.name = "memsw.usage_in_bytes",
.private = MEMFILE_PRIVATE(_MEMSWAP, RES_USAGE),
- .read = mem_cgroup_read,
- .register_event = mem_cgroup_usage_register_event,
- .unregister_event = mem_cgroup_usage_unregister_event,
+ .read_u64 = mem_cgroup_read_u64,
},
{
.name = "memsw.max_usage_in_bytes",
.private = MEMFILE_PRIVATE(_MEMSWAP, RES_MAX_USAGE),
.trigger = mem_cgroup_reset,
- .read = mem_cgroup_read,
+ .read_u64 = mem_cgroup_read_u64,
},
{
.name = "memsw.limit_in_bytes",
.private = MEMFILE_PRIVATE(_MEMSWAP, RES_LIMIT),
.write_string = mem_cgroup_write,
- .read = mem_cgroup_read,
+ .read_u64 = mem_cgroup_read_u64,
},
{
.name = "memsw.failcnt",
.private = MEMFILE_PRIVATE(_MEMSWAP, RES_FAILCNT),
.trigger = mem_cgroup_reset,
- .read = mem_cgroup_read,
+ .read_u64 = mem_cgroup_read_u64,
},
{ }, /* terminate */
};
@@ -6268,6 +6531,8 @@ mem_cgroup_css_alloc(struct cgroup_subsys_state *parent_css)
mutex_init(&memcg->thresholds_lock);
spin_lock_init(&memcg->move_lock);
vmpressure_init(&memcg->vmpressure);
+ INIT_LIST_HEAD(&memcg->event_list);
+ spin_lock_init(&memcg->event_list_lock);
return &memcg->css;
@@ -6343,6 +6608,19 @@ static void mem_cgroup_invalidate_reclaim_iterators(struct mem_cgroup *memcg)
static void mem_cgroup_css_offline(struct cgroup_subsys_state *css)
{
struct mem_cgroup *memcg = mem_cgroup_from_css(css);
+ struct mem_cgroup_event *event, *tmp;
+
+ /*
+ * Unregister events and notify userspace.
+ * Notify userspace about cgroup removing only after rmdir of cgroup
+ * directory to avoid race between userspace and kernelspace.
+ */
+ spin_lock(&memcg->event_list_lock);
+ list_for_each_entry_safe(event, tmp, &memcg->event_list, list) {
+ list_del_init(&event->list);
+ schedule_work(&event->remove);
+ }
+ spin_unlock(&memcg->event_list_lock);
kmem_cgroup_css_offline(memcg);
diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c
index 6d757e3a872a..3bd0b8e6ab12 100644
--- a/mm/page_cgroup.c
+++ b/mm/page_cgroup.c
@@ -451,7 +451,7 @@ unsigned short swap_cgroup_record(swp_entry_t ent, unsigned short id)
* lookup_swap_cgroup_id - lookup mem_cgroup id tied to swap entry
* @ent: swap entry to be looked up.
*
- * Returns CSS ID of mem_cgroup at success. 0 at failure. (0 is invalid ID)
+ * Returns ID of mem_cgroup at success. 0 at failure. (0 is invalid ID)
*/
unsigned short lookup_swap_cgroup_id(swp_entry_t ent)
{
diff --git a/mm/vmpressure.c b/mm/vmpressure.c
index e0f62837c3f4..196970a4541f 100644
--- a/mm/vmpressure.c
+++ b/mm/vmpressure.c
@@ -278,8 +278,7 @@ void vmpressure_prio(gfp_t gfp, struct mem_cgroup *memcg, int prio)
/**
* vmpressure_register_event() - Bind vmpressure notifications to an eventfd
- * @css: css that is interested in vmpressure notifications
- * @cft: cgroup control files handle
+ * @memcg: memcg that is interested in vmpressure notifications
* @eventfd: eventfd context to link notifications with
* @args: event arguments (used to set up a pressure level threshold)
*
@@ -289,15 +288,12 @@ void vmpressure_prio(gfp_t gfp, struct mem_cgroup *memcg, int prio)
* threshold (one of vmpressure_str_levels, i.e. "low", "medium", or
* "critical").
*
- * This function should not be used directly, just pass it to (struct
- * cftype).register_event, and then cgroup core will handle everything by
- * itself.
+ * To be used as memcg event method.
*/
-int vmpressure_register_event(struct cgroup_subsys_state *css,
- struct cftype *cft, struct eventfd_ctx *eventfd,
- const char *args)
+int vmpressure_register_event(struct mem_cgroup *memcg,
+ struct eventfd_ctx *eventfd, const char *args)
{
- struct vmpressure *vmpr = css_to_vmpressure(css);
+ struct vmpressure *vmpr = memcg_to_vmpressure(memcg);
struct vmpressure_event *ev;
int level;
@@ -325,23 +321,19 @@ int vmpressure_register_event(struct cgroup_subsys_state *css,
/**
* vmpressure_unregister_event() - Unbind eventfd from vmpressure
- * @css: css handle
- * @cft: cgroup control files handle
+ * @memcg: memcg handle
* @eventfd: eventfd context that was used to link vmpressure with the @cg
*
* This function does internal manipulations to detach the @eventfd from
* the vmpressure notifications, and then frees internal resources
* associated with the @eventfd (but the @eventfd itself is not freed).
*
- * This function should not be used directly, just pass it to (struct
- * cftype).unregister_event, and then cgroup core will handle everything
- * by itself.
+ * To be used as memcg event method.
*/
-void vmpressure_unregister_event(struct cgroup_subsys_state *css,
- struct cftype *cft,
+void vmpressure_unregister_event(struct mem_cgroup *memcg,
struct eventfd_ctx *eventfd)
{
- struct vmpressure *vmpr = css_to_vmpressure(css);
+ struct vmpressure *vmpr = memcg_to_vmpressure(memcg);
struct vmpressure_event *ev;
mutex_lock(&vmpr->events_lock);
diff --git a/net/core/netprio_cgroup.c b/net/core/netprio_cgroup.c
index 9b7cf6c85f82..56cbb69ba024 100644
--- a/net/core/netprio_cgroup.c
+++ b/net/core/netprio_cgroup.c
@@ -173,14 +173,14 @@ static u64 read_prioidx(struct cgroup_subsys_state *css, struct cftype *cft)
return css->cgroup->id;
}
-static int read_priomap(struct cgroup_subsys_state *css, struct cftype *cft,
- struct cgroup_map_cb *cb)
+static int read_priomap(struct seq_file *sf, void *v)
{
struct net_device *dev;
rcu_read_lock();
for_each_netdev_rcu(&init_net, dev)
- cb->fill(cb, dev->name, netprio_prio(css, dev));
+ seq_printf(sf, "%s %u\n", dev->name,
+ netprio_prio(seq_css(sf), dev));
rcu_read_unlock();
return 0;
}
@@ -238,7 +238,7 @@ static struct cftype ss_files[] = {
},
{
.name = "ifpriomap",
- .read_map = read_priomap,
+ .seq_show = read_priomap,
.write_string = write_priomap,
},
{ } /* terminate */
diff --git a/security/device_cgroup.c b/security/device_cgroup.c
index 7c2a0a71049e..d3b6d2cd3a06 100644
--- a/security/device_cgroup.c
+++ b/security/device_cgroup.c
@@ -274,10 +274,9 @@ static void set_majmin(char *str, unsigned m)
sprintf(str, "%u", m);
}
-static int devcgroup_seq_read(struct cgroup_subsys_state *css,
- struct cftype *cft, struct seq_file *m)
+static int devcgroup_seq_show(struct seq_file *m, void *v)
{
- struct dev_cgroup *devcgroup = css_to_devcgroup(css);
+ struct dev_cgroup *devcgroup = css_to_devcgroup(seq_css(m));
struct dev_exception_item *ex;
char maj[MAJMINLEN], min[MAJMINLEN], acc[ACCLEN];
@@ -679,7 +678,7 @@ static struct cftype dev_cgroup_files[] = {
},
{
.name = "list",
- .read_seq_string = devcgroup_seq_read,
+ .seq_show = devcgroup_seq_show,
.private = DEVCG_LIST,
},
{ } /* terminate */
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-09 22:36:27 +0000