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cgroup: Disable IRQs while holding css_set_lock

While testing the deadline scheduler + cgroup setup I hit this warning. [ 132.612935] ------------[ cut here ]------------ [ 132.612951] WARNING: CPU: 5 PID: 0 at kernel/softirq.c:150 __local_bh_enable_ip+0x6b/0x80 [ 132.612952] Modules linked in: (a ton of modules...) [ 132.612981] CPU: 5 PID: 0 Comm: swapper/5 Not tainted 4.7.0-rc2 #2 [ 132.612981] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.2-20150714_191134- 04/01/2014 [ 132.612982] 0000000000000086 45c8bb5effdd088b ffff88013fd43da0 ffffffff813d229e [ 132.612984] 0000000000000000 0000000000000000 ffff88013fd43de0 ffffffff810a652b [ 132.612985] 00000096811387b5 0000000000000200 ffff8800bab29d80 ffff880034c54c00 [ 132.612986] Call Trace: [ 132.612987] <IRQ> [<ffffffff813d229e>] dump_stack+0x63/0x85 [ 132.612994] [<ffffffff810a652b>] __warn+0xcb/0xf0 [ 132.612997] [<ffffffff810e76a0>] ? push_dl_task.part.32+0x170/0x170 [ 132.612999] [<ffffffff810a665d>] warn_slowpath_null+0x1d/0x20 [ 132.613000] [<ffffffff810aba5b>] __local_bh_enable_ip+0x6b/0x80 [ 132.613008] [<ffffffff817d6c8a>] _raw_write_unlock_bh+0x1a/0x20 [ 132.613010] [<ffffffff817d6c9e>] _raw_spin_unlock_bh+0xe/0x10 [ 132.613015] [<ffffffff811388ac>] put_css_set+0x5c/0x60 [ 132.613016] [<ffffffff8113dc7f>] cgroup_free+0x7f/0xa0 [ 132.613017] [<ffffffff810a3912>] __put_task_struct+0x42/0x140 [ 132.613018] [<ffffffff810e776a>] dl_task_timer+0xca/0x250 [ 132.613027] [<ffffffff810e76a0>] ? push_dl_task.part.32+0x170/0x170 [ 132.613030] [<ffffffff8111371e>] __hrtimer_run_queues+0xee/0x270 [ 132.613031] [<ffffffff81113ec8>] hrtimer_interrupt+0xa8/0x190 [ 132.613034] [<ffffffff81051a58>] local_apic_timer_interrupt+0x38/0x60 [ 132.613035] [<ffffffff817d9b0d>] smp_apic_timer_interrupt+0x3d/0x50 [ 132.613037] [<ffffffff817d7c5c>] apic_timer_interrupt+0x8c/0xa0 [ 132.613038] <EOI> [<ffffffff81063466>] ? native_safe_halt+0x6/0x10 [ 132.613043] [<ffffffff81037a4e>] default_idle+0x1e/0xd0 [ 132.613044] [<ffffffff810381cf>] arch_cpu_idle+0xf/0x20 [ 132.613046] [<ffffffff810e8fda>] default_idle_call+0x2a/0x40 [ 132.613047] [<ffffffff810e92d7>] cpu_startup_entry+0x2e7/0x340 [ 132.613048] [<ffffffff81050235>] start_secondary+0x155/0x190 [ 132.613049] ---[ end trace f91934d162ce9977 ]--- The warn is the spin_(lock|unlock)_bh(&css_set_lock) in the interrupt context. Converting the spin_lock_bh to spin_lock_irq(save) to avoid this problem - and other problems of sharing a spinlock with an interrupt.

Daniel Bristot de Oliveira committed 10 years ago

Commit 82d64891 parent 8fa3b8d1 file · +74 −68Browse files

Unified · Split

kernel/cgroup.c+74−68
@@ -837,6 +837,8 @@ static void put_css_set_locked(struct css_set *cset) · 836 unmodified lines
837 837
838static void put_css_set(struct css_set *cset)838static void put_css_set(struct css_set *cset)
839{839{
840 unsigned long flags;
841
840 /*842 /*
841 * Ensure that the refcount doesn't hit zero while any readers843 * Ensure that the refcount doesn't hit zero while any readers
842 * can see it. Similar to atomic_dec_and_lock(), but for an844 * can see it. Similar to atomic_dec_and_lock(), but for an
@@ -845,9 +847,9 @@ static void put_css_set(struct css_set *cset) · 2 unmodified lines
845 if (atomic_add_unless(&cset->refcount, -1, 1))847 if (atomic_add_unless(&cset->refcount, -1, 1))
846 return;848 return;
847 849
848 spin_lock_bh(&css_set_lock);850 spin_lock_irqsave(&css_set_lock, flags);
849 put_css_set_locked(cset);851 put_css_set_locked(cset);
850 spin_unlock_bh(&css_set_lock);852 spin_unlock_irqrestore(&css_set_lock, flags);
851}853}
852 854
853/*855/*
@@ -1070,11 +1072,11 @@ static struct css_set *find_css_set(struct css_set *old_cset, · 216 unmodified lines
1070 1072
1071 /* First see if we already have a cgroup group that matches1073 /* First see if we already have a cgroup group that matches
1072 * the desired set */1074 * the desired set */
1073 spin_lock_bh(&css_set_lock);1075 spin_lock_irq(&css_set_lock);
1074 cset = find_existing_css_set(old_cset, cgrp, template);1076 cset = find_existing_css_set(old_cset, cgrp, template);
1075 if (cset)1077 if (cset)
1076 get_css_set(cset);1078 get_css_set(cset);
1077 spin_unlock_bh(&css_set_lock);1079 spin_unlock_irq(&css_set_lock);
1078 1080
1079 if (cset)1081 if (cset)
1080 return cset;1082 return cset;
@@ -1102,7 +1104,7 @@ static struct css_set *find_css_set(struct css_set *old_cset, · 21 unmodified lines
1102 * find_existing_css_set() */1104 * find_existing_css_set() */
1103 memcpy(cset->subsys, template, sizeof(cset->subsys));1105 memcpy(cset->subsys, template, sizeof(cset->subsys));
1104 1106
1105 spin_lock_bh(&css_set_lock);1107 spin_lock_irq(&css_set_lock);
1106 /* Add reference counts and links from the new css_set. */1108 /* Add reference counts and links from the new css_set. */
1107 list_for_each_entry(link, &old_cset->cgrp_links, cgrp_link) {1109 list_for_each_entry(link, &old_cset->cgrp_links, cgrp_link) {
1108 struct cgroup *c = link->cgrp;1110 struct cgroup *c = link->cgrp;
@@ -1128,7 +1130,7 @@ static struct css_set *find_css_set(struct css_set *old_cset, · 19 unmodified lines
1128 css_get(css);1130 css_get(css);
1129 }1131 }
1130 1132
1131 spin_unlock_bh(&css_set_lock);1133 spin_unlock_irq(&css_set_lock);
1132 1134
1133 return cset;1135 return cset;
1134}1136}
@@ -1192,7 +1194,7 @@ static void cgroup_destroy_root(struct cgroup_root *root) · 57 unmodified lines
1192 * Release all the links from cset_links to this hierarchy's1194 * Release all the links from cset_links to this hierarchy's
1193 * root cgroup1195 * root cgroup
1194 */1196 */
1195 spin_lock_bh(&css_set_lock);1197 spin_lock_irq(&css_set_lock);
1196 1198
1197 list_for_each_entry_safe(link, tmp_link, &cgrp->cset_links, cset_link) {1199 list_for_each_entry_safe(link, tmp_link, &cgrp->cset_links, cset_link) {
1198 list_del(&link->cset_link);1200 list_del(&link->cset_link);
@@ -1200,7 +1202,7 @@ static void cgroup_destroy_root(struct cgroup_root *root) · 1 unmodified line
1200 kfree(link);1202 kfree(link);
1201 }1203 }
1202 1204
1203 spin_unlock_bh(&css_set_lock);1205 spin_unlock_irq(&css_set_lock);
1204 1206
1205 if (!list_empty(&root->root_list)) {1207 if (!list_empty(&root->root_list)) {
1206 list_del(&root->root_list);1208 list_del(&root->root_list);
@@ -1600,11 +1602,11 @@ static int rebind_subsystems(struct cgroup_root *dst_root, u16 ss_mask) · 393 unmodified lines
1600 ss->root = dst_root;1602 ss->root = dst_root;
1601 css->cgroup = dcgrp;1603 css->cgroup = dcgrp;
1602 1604
1603 spin_lock_bh(&css_set_lock);1605 spin_lock_irq(&css_set_lock);
1604 hash_for_each(css_set_table, i, cset, hlist)1606 hash_for_each(css_set_table, i, cset, hlist)
1605 list_move_tail(&cset->e_cset_node[ss->id],1607 list_move_tail(&cset->e_cset_node[ss->id],
1606 &dcgrp->e_csets[ss->id]);1608 &dcgrp->e_csets[ss->id]);
1607 spin_unlock_bh(&css_set_lock);1609 spin_unlock_irq(&css_set_lock);
1608 1610
1609 /* default hierarchy doesn't enable controllers by default */1611 /* default hierarchy doesn't enable controllers by default */
1610 dst_root->subsys_mask |= 1 << ssid;1612 dst_root->subsys_mask |= 1 << ssid;
@@ -1640,10 +1642,10 @@ static int cgroup_show_path(struct seq_file *sf, struct kernfs_node *kf_node, · 29 unmodified lines
1640 if (!buf)1642 if (!buf)
1641 return -ENOMEM;1643 return -ENOMEM;
1642 1644
1643 spin_lock_bh(&css_set_lock);1645 spin_lock_irq(&css_set_lock);
1644 ns_cgroup = current_cgns_cgroup_from_root(kf_cgroot);1646 ns_cgroup = current_cgns_cgroup_from_root(kf_cgroot);
1645 len = kernfs_path_from_node(kf_node, ns_cgroup->kn, buf, PATH_MAX);1647 len = kernfs_path_from_node(kf_node, ns_cgroup->kn, buf, PATH_MAX);
1646 spin_unlock_bh(&css_set_lock);1648 spin_unlock_irq(&css_set_lock);
1647 1649
1648 if (len >= PATH_MAX)1650 if (len >= PATH_MAX)
1649 len = -ERANGE;1651 len = -ERANGE;
@@ -1897,7 +1899,7 @@ static void cgroup_enable_task_cg_lists(void) · 247 unmodified lines
1897{1899{
1898 struct task_struct *p, *g;1900 struct task_struct *p, *g;
1899 1901
1900 spin_lock_bh(&css_set_lock);1902 spin_lock_irq(&css_set_lock);
1901 1903
1902 if (use_task_css_set_links)1904 if (use_task_css_set_links)
1903 goto out_unlock;1905 goto out_unlock;
@@ -1922,8 +1924,12 @@ static void cgroup_enable_task_cg_lists(void) · 18 unmodified lines
1922 * entry won't be deleted though the process has exited.1924 * entry won't be deleted though the process has exited.
1923 * Do it while holding siglock so that we don't end up1925 * Do it while holding siglock so that we don't end up
1924 * racing against cgroup_exit().1926 * racing against cgroup_exit().
1927 *
1928 * Interrupts were already disabled while acquiring
1929 * the css_set_lock, so we do not need to disable it
1930 * again when acquiring the sighand->siglock here.
1925 */1931 */
1926 spin_lock_irq(&p->sighand->siglock);1932 spin_lock(&p->sighand->siglock);
1927 if (!(p->flags & PF_EXITING)) {1933 if (!(p->flags & PF_EXITING)) {
1928 struct css_set *cset = task_css_set(p);1934 struct css_set *cset = task_css_set(p);
1929 1935
@@ -1932,11 +1938,11 @@ static void cgroup_enable_task_cg_lists(void) · 2 unmodified lines
1932 list_add_tail(&p->cg_list, &cset->tasks);1938 list_add_tail(&p->cg_list, &cset->tasks);
1933 get_css_set(cset);1939 get_css_set(cset);
1934 }1940 }
1935 spin_unlock_irq(&p->sighand->siglock);1941 spin_unlock(&p->sighand->siglock);
1936 } while_each_thread(g, p);1942 } while_each_thread(g, p);
1937 read_unlock(&tasklist_lock);1943 read_unlock(&tasklist_lock);
1938out_unlock:1944out_unlock:
1939 spin_unlock_bh(&css_set_lock);1945 spin_unlock_irq(&css_set_lock);
1940}1946}
1941 1947
1942static void init_cgroup_housekeeping(struct cgroup *cgrp)1948static void init_cgroup_housekeeping(struct cgroup *cgrp)
@@ -2043,13 +2049,13 @@ static int cgroup_setup_root(struct cgroup_root *root, u16 ss_mask) · 100 unmodified lines
2043 * Link the root cgroup in this hierarchy into all the css_set2049 * Link the root cgroup in this hierarchy into all the css_set
2044 * objects.2050 * objects.
2045 */2051 */
2046 spin_lock_bh(&css_set_lock);2052 spin_lock_irq(&css_set_lock);
2047 hash_for_each(css_set_table, i, cset, hlist) {2053 hash_for_each(css_set_table, i, cset, hlist) {
2048 link_css_set(&tmp_links, cset, root_cgrp);2054 link_css_set(&tmp_links, cset, root_cgrp);
2049 if (css_set_populated(cset))2055 if (css_set_populated(cset))
2050 cgroup_update_populated(root_cgrp, true);2056 cgroup_update_populated(root_cgrp, true);
2051 }2057 }
2052 spin_unlock_bh(&css_set_lock);2058 spin_unlock_irq(&css_set_lock);
2053 2059
2054 BUG_ON(!list_empty(&root_cgrp->self.children));2060 BUG_ON(!list_empty(&root_cgrp->self.children));
2055 BUG_ON(atomic_read(&root->nr_cgrps) != 1);2061 BUG_ON(atomic_read(&root->nr_cgrps) != 1);
@@ -2256,11 +2262,11 @@ out_mount: · 200 unmodified lines
2256 struct cgroup *cgrp;2262 struct cgroup *cgrp;
2257 2263
2258 mutex_lock(&cgroup_mutex);2264 mutex_lock(&cgroup_mutex);
2259 spin_lock_bh(&css_set_lock);2265 spin_lock_irq(&css_set_lock);
2260 2266
2261 cgrp = cset_cgroup_from_root(ns->root_cset, root);2267 cgrp = cset_cgroup_from_root(ns->root_cset, root);
2262 2268
2263 spin_unlock_bh(&css_set_lock);2269 spin_unlock_irq(&css_set_lock);
2264 mutex_unlock(&cgroup_mutex);2270 mutex_unlock(&cgroup_mutex);
2265 2271
2266 nsdentry = kernfs_node_dentry(cgrp->kn, dentry->d_sb);2272 nsdentry = kernfs_node_dentry(cgrp->kn, dentry->d_sb);
@@ -2337,11 +2343,11 @@ char *cgroup_path_ns(struct cgroup *cgrp, char *buf, size_t buflen, · 70 unmodified lines
2337 char *ret;2343 char *ret;
2338 2344
2339 mutex_lock(&cgroup_mutex);2345 mutex_lock(&cgroup_mutex);
2340 spin_lock_bh(&css_set_lock);2346 spin_lock_irq(&css_set_lock);
2341 2347
2342 ret = cgroup_path_ns_locked(cgrp, buf, buflen, ns);2348 ret = cgroup_path_ns_locked(cgrp, buf, buflen, ns);
2343 2349
2344 spin_unlock_bh(&css_set_lock);2350 spin_unlock_irq(&css_set_lock);
2345 mutex_unlock(&cgroup_mutex);2351 mutex_unlock(&cgroup_mutex);
2346 2352
2347 return ret;2353 return ret;
@@ -2369,7 +2375,7 @@ char *task_cgroup_path(struct task_struct *task, char *buf, size_t buflen) · 21 unmodified lines
2369 char *path = NULL;2375 char *path = NULL;
2370 2376
2371 mutex_lock(&cgroup_mutex);2377 mutex_lock(&cgroup_mutex);
2372 spin_lock_bh(&css_set_lock);2378 spin_lock_irq(&css_set_lock);
2373 2379
2374 root = idr_get_next(&cgroup_hierarchy_idr, &hierarchy_id);2380 root = idr_get_next(&cgroup_hierarchy_idr, &hierarchy_id);
2375 2381
@@ -2382,7 +2388,7 @@ char *task_cgroup_path(struct task_struct *task, char *buf, size_t buflen) · 6 unmodified lines
2382 path = buf;2388 path = buf;
2383 }2389 }
2384 2390
2385 spin_unlock_bh(&css_set_lock);2391 spin_unlock_irq(&css_set_lock);
2386 mutex_unlock(&cgroup_mutex);2392 mutex_unlock(&cgroup_mutex);
2387 return path;2393 return path;
2388}2394}
@@ -2557,7 +2563,7 @@ static int cgroup_taskset_migrate(struct cgroup_taskset *tset, · 168 unmodified lines
2557 * the new cgroup. There are no failure cases after here, so this2563 * the new cgroup. There are no failure cases after here, so this
2558 * is the commit point.2564 * is the commit point.
2559 */2565 */
2560 spin_lock_bh(&css_set_lock);2566 spin_lock_irq(&css_set_lock);
2561 list_for_each_entry(cset, &tset->src_csets, mg_node) {2567 list_for_each_entry(cset, &tset->src_csets, mg_node) {
2562 list_for_each_entry_safe(task, tmp_task, &cset->mg_tasks, cg_list) {2568 list_for_each_entry_safe(task, tmp_task, &cset->mg_tasks, cg_list) {
2563 struct css_set *from_cset = task_css_set(task);2569 struct css_set *from_cset = task_css_set(task);
@@ -2568,7 +2574,7 @@ static int cgroup_taskset_migrate(struct cgroup_taskset *tset, · 4 unmodified lines
2568 put_css_set_locked(from_cset);2574 put_css_set_locked(from_cset);
2569 }2575 }
2570 }2576 }
2571 spin_unlock_bh(&css_set_lock);2577 spin_unlock_irq(&css_set_lock);
2572 2578
2573 /*2579 /*
2574 * Migration is committed, all target tasks are now on dst_csets.2580 * Migration is committed, all target tasks are now on dst_csets.
@@ -2597,13 +2603,13 @@ out_cancel_attach: · 22 unmodified lines
2597 }2603 }
2598 } while_each_subsys_mask();2604 } while_each_subsys_mask();
2599out_release_tset:2605out_release_tset:
2600 spin_lock_bh(&css_set_lock);2606 spin_lock_irq(&css_set_lock);
2601 list_splice_init(&tset->dst_csets, &tset->src_csets);2607 list_splice_init(&tset->dst_csets, &tset->src_csets);
2602 list_for_each_entry_safe(cset, tmp_cset, &tset->src_csets, mg_node) {2608 list_for_each_entry_safe(cset, tmp_cset, &tset->src_csets, mg_node) {
2603 list_splice_tail_init(&cset->mg_tasks, &cset->tasks);2609 list_splice_tail_init(&cset->mg_tasks, &cset->tasks);
2604 list_del_init(&cset->mg_node);2610 list_del_init(&cset->mg_node);
2605 }2611 }
2606 spin_unlock_bh(&css_set_lock);2612 spin_unlock_irq(&css_set_lock);
2607 return ret;2613 return ret;
2608}2614}
2609 2615
@@ -2634,7 +2640,7 @@ static void cgroup_migrate_finish(struct list_head *preloaded_csets) · 24 unmodified lines
2634 2640
2635 lockdep_assert_held(&cgroup_mutex);2641 lockdep_assert_held(&cgroup_mutex);
2636 2642
2637 spin_lock_bh(&css_set_lock);2643 spin_lock_irq(&css_set_lock);
2638 list_for_each_entry_safe(cset, tmp_cset, preloaded_csets, mg_preload_node) {2644 list_for_each_entry_safe(cset, tmp_cset, preloaded_csets, mg_preload_node) {
2639 cset->mg_src_cgrp = NULL;2645 cset->mg_src_cgrp = NULL;
2640 cset->mg_dst_cgrp = NULL;2646 cset->mg_dst_cgrp = NULL;
@@ -2642,7 +2648,7 @@ static void cgroup_migrate_finish(struct list_head *preloaded_csets) · 1 unmodified line
2642 list_del_init(&cset->mg_preload_node);2648 list_del_init(&cset->mg_preload_node);
2643 put_css_set_locked(cset);2649 put_css_set_locked(cset);
2644 }2650 }
2645 spin_unlock_bh(&css_set_lock);2651 spin_unlock_irq(&css_set_lock);
2646}2652}
2647 2653
2648/**2654/**
@@ -2783,7 +2789,7 @@ static int cgroup_migrate(struct task_struct *leader, bool threadgroup, · 134 unmodified lines
2783 * already PF_EXITING could be freed from underneath us unless we2789 * already PF_EXITING could be freed from underneath us unless we
2784 * take an rcu_read_lock.2790 * take an rcu_read_lock.
2785 */2791 */
2786 spin_lock_bh(&css_set_lock);2792 spin_lock_irq(&css_set_lock);
2787 rcu_read_lock();2793 rcu_read_lock();
2788 task = leader;2794 task = leader;
2789 do {2795 do {
@@ -2792,7 +2798,7 @@ static int cgroup_migrate(struct task_struct *leader, bool threadgroup, · 2 unmodified lines
2792 break;2798 break;
2793 } while_each_thread(leader, task);2799 } while_each_thread(leader, task);
2794 rcu_read_unlock();2800 rcu_read_unlock();
2795 spin_unlock_bh(&css_set_lock);2801 spin_unlock_irq(&css_set_lock);
2796 2802
2797 return cgroup_taskset_migrate(&tset, root);2803 return cgroup_taskset_migrate(&tset, root);
2798}2804}
@@ -2816,7 +2822,7 @@ static int cgroup_attach_task(struct cgroup *dst_cgrp, · 17 unmodified lines
2816 return -EBUSY;2822 return -EBUSY;
2817 2823
2818 /* look up all src csets */2824 /* look up all src csets */
2819 spin_lock_bh(&css_set_lock);2825 spin_lock_irq(&css_set_lock);
2820 rcu_read_lock();2826 rcu_read_lock();
2821 task = leader;2827 task = leader;
2822 do {2828 do {
@@ -2826,7 +2832,7 @@ static int cgroup_attach_task(struct cgroup *dst_cgrp, · 3 unmodified lines
2826 break;2832 break;
2827 } while_each_thread(leader, task);2833 } while_each_thread(leader, task);
2828 rcu_read_unlock();2834 rcu_read_unlock();
2829 spin_unlock_bh(&css_set_lock);2835 spin_unlock_irq(&css_set_lock);
2830 2836
2831 /* prepare dst csets and commit */2837 /* prepare dst csets and commit */
2832 ret = cgroup_migrate_prepare_dst(&preloaded_csets);2838 ret = cgroup_migrate_prepare_dst(&preloaded_csets);
@@ -2859,9 +2865,9 @@ static int cgroup_procs_write_permission(struct task_struct *task, · 26 unmodified lines
2859 struct cgroup *cgrp;2865 struct cgroup *cgrp;
2860 struct inode *inode;2866 struct inode *inode;
2861 2867
2862 spin_lock_bh(&css_set_lock);2868 spin_lock_irq(&css_set_lock);
2863 cgrp = task_cgroup_from_root(task, &cgrp_dfl_root);2869 cgrp = task_cgroup_from_root(task, &cgrp_dfl_root);
2864 spin_unlock_bh(&css_set_lock);2870 spin_unlock_irq(&css_set_lock);
2865 2871
2866 while (!cgroup_is_descendant(dst_cgrp, cgrp))2872 while (!cgroup_is_descendant(dst_cgrp, cgrp))
2867 cgrp = cgroup_parent(cgrp);2873 cgrp = cgroup_parent(cgrp);
@@ -2962,9 +2968,9 @@ int cgroup_attach_task_all(struct task_struct *from, struct task_struct *tsk) · 94 unmodified lines
2962 if (root == &cgrp_dfl_root)2968 if (root == &cgrp_dfl_root)
2963 continue;2969 continue;
2964 2970
2965 spin_lock_bh(&css_set_lock);2971 spin_lock_irq(&css_set_lock);
2966 from_cgrp = task_cgroup_from_root(from, root);2972 from_cgrp = task_cgroup_from_root(from, root);
2967 spin_unlock_bh(&css_set_lock);2973 spin_unlock_irq(&css_set_lock);
2968 2974
2969 retval = cgroup_attach_task(from_cgrp, tsk, false);2975 retval = cgroup_attach_task(from_cgrp, tsk, false);
2970 if (retval)2976 if (retval)
@@ -3080,7 +3086,7 @@ static int cgroup_update_dfl_csses(struct cgroup *cgrp) · 109 unmodified lines
3080 percpu_down_write(&cgroup_threadgroup_rwsem);3086 percpu_down_write(&cgroup_threadgroup_rwsem);
3081 3087
3082 /* look up all csses currently attached to @cgrp's subtree */3088 /* look up all csses currently attached to @cgrp's subtree */
3083 spin_lock_bh(&css_set_lock);3089 spin_lock_irq(&css_set_lock);
3084 cgroup_for_each_live_descendant_pre(dsct, d_css, cgrp) {3090 cgroup_for_each_live_descendant_pre(dsct, d_css, cgrp) {
3085 struct cgrp_cset_link *link;3091 struct cgrp_cset_link *link;
3086 3092
@@ -3088,14 +3094,14 @@ static int cgroup_update_dfl_csses(struct cgroup *cgrp) · 1 unmodified line
3088 cgroup_migrate_add_src(link->cset, dsct,3094 cgroup_migrate_add_src(link->cset, dsct,
3089 &preloaded_csets);3095 &preloaded_csets);
3090 }3096 }
3091 spin_unlock_bh(&css_set_lock);3097 spin_unlock_irq(&css_set_lock);
3092 3098
3093 /* NULL dst indicates self on default hierarchy */3099 /* NULL dst indicates self on default hierarchy */
3094 ret = cgroup_migrate_prepare_dst(&preloaded_csets);3100 ret = cgroup_migrate_prepare_dst(&preloaded_csets);
3095 if (ret)3101 if (ret)
3096 goto out_finish;3102 goto out_finish;
3097 3103
3098 spin_lock_bh(&css_set_lock);3104 spin_lock_irq(&css_set_lock);
3099 list_for_each_entry(src_cset, &preloaded_csets, mg_preload_node) {3105 list_for_each_entry(src_cset, &preloaded_csets, mg_preload_node) {
3100 struct task_struct *task, *ntask;3106 struct task_struct *task, *ntask;
3101 3107
@@ -3107,7 +3113,7 @@ static int cgroup_update_dfl_csses(struct cgroup *cgrp) · 5 unmodified lines
3107 list_for_each_entry_safe(task, ntask, &src_cset->tasks, cg_list)3113 list_for_each_entry_safe(task, ntask, &src_cset->tasks, cg_list)
3108 cgroup_taskset_add(task, &tset);3114 cgroup_taskset_add(task, &tset);
3109 }3115 }
3110 spin_unlock_bh(&css_set_lock);3116 spin_unlock_irq(&css_set_lock);
3111 3117
3112 ret = cgroup_taskset_migrate(&tset, cgrp->root);3118 ret = cgroup_taskset_migrate(&tset, cgrp->root);
3113out_finish:3119out_finish:
@@ -3908,10 +3914,10 @@ static int cgroup_task_count(const struct cgroup *cgrp) · 794 unmodified lines
3908 int count = 0;3914 int count = 0;
3909 struct cgrp_cset_link *link;3915 struct cgrp_cset_link *link;
3910 3916
3911 spin_lock_bh(&css_set_lock);3917 spin_lock_irq(&css_set_lock);
3912 list_for_each_entry(link, &cgrp->cset_links, cset_link)3918 list_for_each_entry(link, &cgrp->cset_links, cset_link)
3913 count += atomic_read(&link->cset->refcount);3919 count += atomic_read(&link->cset->refcount);
3914 spin_unlock_bh(&css_set_lock);3920 spin_unlock_irq(&css_set_lock);
3915 return count;3921 return count;
3916}3922}
3917 3923
@@ -4249,7 +4255,7 @@ void css_task_iter_start(struct cgroup_subsys_state *css, · 331 unmodified lines
4249 4255
4250 memset(it, 0, sizeof(*it));4256 memset(it, 0, sizeof(*it));
4251 4257
4252 spin_lock_bh(&css_set_lock);4258 spin_lock_irq(&css_set_lock);
4253 4259
4254 it->ss = css->ss;4260 it->ss = css->ss;
4255 4261
@@ -4262,7 +4268,7 @@ void css_task_iter_start(struct cgroup_subsys_state *css, · 6 unmodified lines
4262 4268
4263 css_task_iter_advance_css_set(it);4269 css_task_iter_advance_css_set(it);
4264 4270
4265 spin_unlock_bh(&css_set_lock);4271 spin_unlock_irq(&css_set_lock);
4266}4272}
4267 4273
4268/**4274/**
@@ -4280,7 +4286,7 @@ struct task_struct *css_task_iter_next(struct css_task_iter *it) · 11 unmodified lines
4280 it->cur_task = NULL;4286 it->cur_task = NULL;
4281 }4287 }
4282 4288
4283 spin_lock_bh(&css_set_lock);4289 spin_lock_irq(&css_set_lock);
4284 4290
4285 if (it->task_pos) {4291 if (it->task_pos) {
4286 it->cur_task = list_entry(it->task_pos, struct task_struct,4292 it->cur_task = list_entry(it->task_pos, struct task_struct,
@@ -4289,7 +4295,7 @@ struct task_struct *css_task_iter_next(struct css_task_iter *it) · 2 unmodified lines
4289 css_task_iter_advance(it);4295 css_task_iter_advance(it);
4290 }4296 }
4291 4297
4292 spin_unlock_bh(&css_set_lock);4298 spin_unlock_irq(&css_set_lock);
4293 4299
4294 return it->cur_task;4300 return it->cur_task;
4295}4301}
@@ -4303,10 +4309,10 @@ struct task_struct *css_task_iter_next(struct css_task_iter *it) · 7 unmodified lines
4303void css_task_iter_end(struct css_task_iter *it)4309void css_task_iter_end(struct css_task_iter *it)
4304{4310{
4305 if (it->cur_cset) {4311 if (it->cur_cset) {
4306 spin_lock_bh(&css_set_lock);4312 spin_lock_irq(&css_set_lock);
4307 list_del(&it->iters_node);4313 list_del(&it->iters_node);
4308 put_css_set_locked(it->cur_cset);4314 put_css_set_locked(it->cur_cset);
4309 spin_unlock_bh(&css_set_lock);4315 spin_unlock_irq(&css_set_lock);
4310 }4316 }
4311 4317
4312 if (it->cur_task)4318 if (it->cur_task)
@@ -4338,10 +4344,10 @@ int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from) · 25 unmodified lines
4338 mutex_lock(&cgroup_mutex);4344 mutex_lock(&cgroup_mutex);
4339 4345
4340 /* all tasks in @from are being moved, all csets are source */4346 /* all tasks in @from are being moved, all csets are source */
4341 spin_lock_bh(&css_set_lock);4347 spin_lock_irq(&css_set_lock);
4342 list_for_each_entry(link, &from->cset_links, cset_link)4348 list_for_each_entry(link, &from->cset_links, cset_link)
4343 cgroup_migrate_add_src(link->cset, to, &preloaded_csets);4349 cgroup_migrate_add_src(link->cset, to, &preloaded_csets);
4344 spin_unlock_bh(&css_set_lock);4350 spin_unlock_irq(&css_set_lock);
4345 4351
4346 ret = cgroup_migrate_prepare_dst(&preloaded_csets);4352 ret = cgroup_migrate_prepare_dst(&preloaded_csets);
4347 if (ret)4353 if (ret)
@@ -5449,10 +5455,10 @@ static int cgroup_destroy_locked(struct cgroup *cgrp) · 1101 unmodified lines
5449 */5455 */
5450 cgrp->self.flags &= ~CSS_ONLINE;5456 cgrp->self.flags &= ~CSS_ONLINE;
5451 5457
5452 spin_lock_bh(&css_set_lock);5458 spin_lock_irq(&css_set_lock);
5453 list_for_each_entry(link, &cgrp->cset_links, cset_link)5459 list_for_each_entry(link, &cgrp->cset_links, cset_link)
5454 link->cset->dead = true;5460 link->cset->dead = true;
5455 spin_unlock_bh(&css_set_lock);5461 spin_unlock_irq(&css_set_lock);
5456 5462
5457 /* initiate massacre of all css's */5463 /* initiate massacre of all css's */
5458 for_each_css(css, ssid, cgrp)5464 for_each_css(css, ssid, cgrp)
@@ -5723,7 +5729,7 @@ int proc_cgroup_show(struct seq_file *m, struct pid_namespace *ns, · 264 unmodified lines
5723 goto out;5729 goto out;
5724 5730
5725 mutex_lock(&cgroup_mutex);5731 mutex_lock(&cgroup_mutex);
5726 spin_lock_bh(&css_set_lock);5732 spin_lock_irq(&css_set_lock);
5727 5733
5728 for_each_root(root) {5734 for_each_root(root) {
5729 struct cgroup_subsys *ss;5735 struct cgroup_subsys *ss;
@@ -5776,7 +5782,7 @@ int proc_cgroup_show(struct seq_file *m, struct pid_namespace *ns, · 46 unmodified lines
5776 5782
5777 retval = 0;5783 retval = 0;
5778out_unlock:5784out_unlock:
5779 spin_unlock_bh(&css_set_lock);5785 spin_unlock_irq(&css_set_lock);
5780 mutex_unlock(&cgroup_mutex);5786 mutex_unlock(&cgroup_mutex);
5781 kfree(buf);5787 kfree(buf);
5782out:5788out:
@@ -5921,13 +5927,13 @@ void cgroup_post_fork(struct task_struct *child) · 138 unmodified lines
5921 if (use_task_css_set_links) {5927 if (use_task_css_set_links) {
5922 struct css_set *cset;5928 struct css_set *cset;
5923 5929
5924 spin_lock_bh(&css_set_lock);5930 spin_lock_irq(&css_set_lock);
5925 cset = task_css_set(current);5931 cset = task_css_set(current);
5926 if (list_empty(&child->cg_list)) {5932 if (list_empty(&child->cg_list)) {
5927 get_css_set(cset);5933 get_css_set(cset);
5928 css_set_move_task(child, NULL, cset, false);5934 css_set_move_task(child, NULL, cset, false);
5929 }5935 }
5930 spin_unlock_bh(&css_set_lock);5936 spin_unlock_irq(&css_set_lock);
5931 }5937 }
5932 5938
5933 /*5939 /*
@@ -5972,9 +5978,9 @@ void cgroup_exit(struct task_struct *tsk) · 38 unmodified lines
5972 cset = task_css_set(tsk);5978 cset = task_css_set(tsk);
5973 5979
5974 if (!list_empty(&tsk->cg_list)) {5980 if (!list_empty(&tsk->cg_list)) {
5975 spin_lock_bh(&css_set_lock);5981 spin_lock_irq(&css_set_lock);
5976 css_set_move_task(tsk, cset, NULL, false);5982 css_set_move_task(tsk, cset, NULL, false);
5977 spin_unlock_bh(&css_set_lock);5983 spin_unlock_irq(&css_set_lock);
5978 } else {5984 } else {
5979 get_css_set(cset);5985 get_css_set(cset);
5980 }5986 }
@@ -6042,9 +6048,9 @@ static void cgroup_release_agent(struct work_struct *work) · 61 unmodified lines
6042 if (!pathbuf || !agentbuf)6048 if (!pathbuf || !agentbuf)
6043 goto out;6049 goto out;
6044 6050
6045 spin_lock_bh(&css_set_lock);6051 spin_lock_irq(&css_set_lock);
6046 path = cgroup_path_ns_locked(cgrp, pathbuf, PATH_MAX, &init_cgroup_ns);6052 path = cgroup_path_ns_locked(cgrp, pathbuf, PATH_MAX, &init_cgroup_ns);
6047 spin_unlock_bh(&css_set_lock);6053 spin_unlock_irq(&css_set_lock);
6048 if (!path)6054 if (!path)
6049 goto out;6055 goto out;
6050 6056
@@ -6304,12 +6310,12 @@ struct cgroup_namespace *copy_cgroup_ns(unsigned long flags, · 253 unmodified lines
6304 return ERR_PTR(-EPERM);6310 return ERR_PTR(-EPERM);
6305 6311
6306 mutex_lock(&cgroup_mutex);6312 mutex_lock(&cgroup_mutex);
6307 spin_lock_bh(&css_set_lock);6313 spin_lock_irq(&css_set_lock);
6308 6314
6309 cset = task_css_set(current);6315 cset = task_css_set(current);
6310 get_css_set(cset);6316 get_css_set(cset);
6311 6317
6312 spin_unlock_bh(&css_set_lock);6318 spin_unlock_irq(&css_set_lock);
6313 mutex_unlock(&cgroup_mutex);6319 mutex_unlock(&cgroup_mutex);
6314 6320
6315 new_ns = alloc_cgroup_ns();6321 new_ns = alloc_cgroup_ns();
@@ -6433,7 +6439,7 @@ static int current_css_set_cg_links_read(struct seq_file *seq, void *v) · 117 unmodified lines
6433 if (!name_buf)6439 if (!name_buf)
6434 return -ENOMEM;6440 return -ENOMEM;
6435 6441
6436 spin_lock_bh(&css_set_lock);6442 spin_lock_irq(&css_set_lock);
6437 rcu_read_lock();6443 rcu_read_lock();
6438 cset = rcu_dereference(current->cgroups);6444 cset = rcu_dereference(current->cgroups);
6439 list_for_each_entry(link, &cset->cgrp_links, cgrp_link) {6445 list_for_each_entry(link, &cset->cgrp_links, cgrp_link) {
@@ -6444,7 +6450,7 @@ static int current_css_set_cg_links_read(struct seq_file *seq, void *v) · 4 unmodified lines
6444 c->root->hierarchy_id, name_buf);6450 c->root->hierarchy_id, name_buf);
6445 }6451 }
6446 rcu_read_unlock();6452 rcu_read_unlock();
6447 spin_unlock_bh(&css_set_lock);6453 spin_unlock_irq(&css_set_lock);
6448 kfree(name_buf);6454 kfree(name_buf);
6449 return 0;6455 return 0;
6450}6456}
@@ -6455,7 +6461,7 @@ static int cgroup_css_links_read(struct seq_file *seq, void *v) · 4 unmodified lines
6455 struct cgroup_subsys_state *css = seq_css(seq);6461 struct cgroup_subsys_state *css = seq_css(seq);
6456 struct cgrp_cset_link *link;6462 struct cgrp_cset_link *link;
6457 6463
6458 spin_lock_bh(&css_set_lock);6464 spin_lock_irq(&css_set_lock);
6459 list_for_each_entry(link, &css->cgroup->cset_links, cset_link) {6465 list_for_each_entry(link, &css->cgroup->cset_links, cset_link) {
6460 struct css_set *cset = link->cset;6466 struct css_set *cset = link->cset;
6461 struct task_struct *task;6467 struct task_struct *task;
@@ -6478,7 +6484,7 @@ static int cgroup_css_links_read(struct seq_file *seq, void *v) · 16 unmodified lines
6478 overflow:6484 overflow:
6479 seq_puts(seq, " ...\n");6485 seq_puts(seq, " ...\n");
6480 }6486 }
6481 spin_unlock_bh(&css_set_lock);6487 spin_unlock_irq(&css_set_lock);
6482 return 0;6488 return 0;
6483}6489}
6484 6490