diff options
| -rw-r--r-- | Documentation/cgroups/cgroups.txt | 20 | ||||
| -rw-r--r-- | Documentation/cgroups/memory.txt | 4 | ||||
| -rw-r--r-- | Documentation/cgroups/resource_counter.txt | 4 | ||||
| -rw-r--r-- | block/blk-throttle.c | 35 | ||||
| -rw-r--r-- | block/cfq-iosched.c | 131 | ||||
| -rw-r--r-- | include/linux/cgroup.h | 109 | ||||
| -rw-r--r-- | include/linux/vmpressure.h | 8 | ||||
| -rw-r--r-- | init/Kconfig | 3 | ||||
| -rw-r--r-- | kernel/cgroup.c | 1197 | ||||
| -rw-r--r-- | kernel/cgroup_freezer.c | 7 | ||||
| -rw-r--r-- | kernel/cpuset.c | 71 | ||||
| -rw-r--r-- | kernel/sched/core.c | 13 | ||||
| -rw-r--r-- | kernel/sched/cpuacct.c | 18 | ||||
| -rw-r--r-- | mm/hugetlb_cgroup.c | 22 | ||||
| -rw-r--r-- | mm/memcontrol.c | 426 | ||||
| -rw-r--r-- | mm/vmpressure.c | 26 | ||||
| -rw-r--r-- | net/core/netprio_cgroup.c | 8 | ||||
| -rw-r--r-- | security/device_cgroup.c | 7 |
18 files changed, 1018 insertions, 1091 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 caa6d662b230..5108afb3645c 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, unsigned 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/include/linux/cgroup.h b/include/linux/cgroup.h index 39c1d9469677..cfaf416492dd 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 @@ -29,7 +30,6 @@ struct cgroup_subsys; struct inode; struct cgroup; struct css_id; -struct eventfd_ctx; extern int cgroup_init_early(void); extern int cgroup_init(void); @@ -239,10 +239,6 @@ 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 +276,9 @@ 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 +319,6 @@ 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 +385,6 @@ 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 +431,6 @@ 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 +440,14 @@ 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 +476,6 @@ 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 +489,26 @@ 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 +523,18 @@ 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 +614,8 @@ 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 4e5d96ab2034..6319b1975899 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..9ed68a339ea6 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; @@ -1976,8 +1962,8 @@ 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 +2036,11 @@ 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 +2076,9 @@ 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 +2095,11 @@ 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: @@ -2260,10 +2239,9 @@ 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 +2251,129 @@ 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); - - return simple_read_from_buffer(buf, nbytes, ppos, tmp, len); -} + struct cftype *cft = seq_cft(m); + struct cgroup_subsys_state *css = seq_css(m); -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->seq_show) + return cft->seq_show(m, arg); - 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 +2382,7 @@ 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 +2412,26 @@ 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 +2542,7 @@ 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 +2567,6 @@ 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 +2624,11 @@ 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 +2924,9 @@ 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 +2936,7 @@ 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 +2983,10 @@ 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 +2994,7 @@ 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 +3025,17 @@ 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 +3071,11 @@ 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 +3083,7 @@ 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 +3422,12 @@ 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 +3443,7 @@ 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 +3453,47 @@ 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 +3523,92 @@ 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 +3625,8 @@ 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 +3653,24 @@ 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 +3744,45 @@ 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 +3793,25 @@ 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 +3822,7 @@ 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 +3843,6 @@ 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 +3877,6 @@ 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 +3896,15 @@ 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 +3913,7 @@ 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 +3924,12 @@ 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 +3941,7 @@ 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 +4087,62 @@ 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 +4154,10 @@ 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 +4213,6 @@ 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 +4220,7 @@ 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 +4232,31 @@ 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 +4269,6 @@ 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 +4391,10 @@ 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 +4430,8 @@ 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 +4466,6 @@ 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 +4536,6 @@ 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 +4609,7 @@ 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 +4621,11 @@ 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 +4655,18 @@ 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 +4685,7 @@ 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 +4697,15 @@ 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 +4728,11 @@ 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 +4851,15 @@ 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 +4903,12 @@ 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 +5249,16 @@ __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 +5281,7 @@ 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 +5329,7 @@ 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 +5354,9 @@ 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 +5402,12 @@ 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 a88f4a485c5e..abc9a1a84d25 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -7258,15 +7258,14 @@ 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; } @@ -7320,7 +7319,7 @@ 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/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 1dda50c2e705..9043caedcd08 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 */ |