Currently __ub_get_css(ub) for dying or stopped container returns ub0-related css as failback. As result read from /proc/bc/<>/ files can show ve0-related info.
With this patch, __ub_get_css() will return NULL in such cases, and everyone who called of this function now handles this return value. https://jira.sw.ru/browse/PSBM-123686 Signed-off-by: Vasily Averin <[email protected]> --- v2: removed an extra cehck in end of __ub_get_css(), thanks to eshatokhin@ include/bc/beancounter.h | 10 +++++++- kernel/bc/beancounter.c | 65 +++++++++++++++++++++++++++++++++++------------- kernel/bc/io_prio.c | 13 ++++++++-- kernel/bc/proc.c | 3 +++ kernel/bc/vm_pages.c | 18 +++++++++++--- 5 files changed, 85 insertions(+), 24 deletions(-) diff --git a/include/bc/beancounter.h b/include/bc/beancounter.h index e4c5017..4b69a34 100644 --- a/include/bc/beancounter.h +++ b/include/bc/beancounter.h @@ -163,6 +163,10 @@ static __always_inline struct cgroup_subsys_state *__ub_get_css(struct user_bean css = ACCESS_ONCE(ub->ub_bound_css[idx]); if (likely(css && css_tryget(css))) { rcu_read_unlock(); + if ((ub != &ub0) && (css == ub0.ub_bound_css[idx])) { + css_put(css); + css = NULL; + } return css; } @@ -183,7 +187,11 @@ static __always_inline struct cgroup_subsys_state *__ub_get_css(struct user_bean if (css) css_put(css); - css_get(root_css); + if (ub == &ub0) + css_get(root_css); + else + root_css = NULL; + return root_css; } diff --git a/kernel/bc/beancounter.c b/kernel/bc/beancounter.c index 5e04d6c..ae8d21a 100644 --- a/kernel/bc/beancounter.c +++ b/kernel/bc/beancounter.c @@ -117,33 +117,53 @@ int ub_attach_task(struct user_beancounter *ub, struct task_struct *tsk) { int ret = 0; struct user_beancounter *old_ub = tsk->task_bc.exec_ub; - struct cgroup_subsys_state *css; + struct cgroup_subsys_state *css, *com, *cob; if (ub == old_ub) goto out; + + ret = -ENODEV; + com = ub_get_mem_css(old_ub); + if (!com) + goto out; + + cob = ub_get_blkio_css(old_ub); + if (!cob) + goto fail_om; + css = ub_get_mem_css(ub); + if (!css) + goto fail_ob; + ret = cgroup_kernel_attach(css->cgroup, tsk); css_put(css); if (ret) - goto out; + goto fail_ob; + + ret = -ENODEV; css = ub_get_blkio_css(ub); + if (!css) + goto fail_blkio; + ret = cgroup_kernel_attach(css->cgroup, tsk); css_put(css); if (ret) goto fail_blkio; + ret = cgroup_kernel_attach(ub->css.cgroup, tsk); if (ret) goto fail_ub; + +fail_ob: + css_put(cob); +fail_om: + css_put(com); out: return ret; fail_ub: - css = ub_get_blkio_css(old_ub); - cgroup_kernel_attach(css->cgroup, tsk); - css_put(css); + cgroup_kernel_attach(cob->cgroup, tsk); fail_blkio: - css = ub_get_mem_css(old_ub); - cgroup_kernel_attach(css->cgroup, tsk); - css_put(css); + cgroup_kernel_attach(com->cgroup, tsk); goto out; } @@ -167,6 +187,9 @@ int ub_update_memcg(struct user_beancounter *ub) int ret; css = ub_get_mem_css(ub); + if (!css) + return -ENODEV; + ret = mem_cgroup_apply_beancounter(mem_cgroup_from_cont(css->cgroup), ub); css_put(css); @@ -181,8 +204,10 @@ void ub_sync_pids(struct user_beancounter *ub) struct cgroup_subsys_state *css; css = ub_get_pids_css(ub); - pids_cgroup_sync_beancounter(pids_cgroup_from_cont(css->cgroup), ub); - css_put(css); + if (css) { + pids_cgroup_sync_beancounter(pids_cgroup_from_cont(css->cgroup), ub); + css_put(css); + } } /* @@ -193,18 +218,22 @@ void ub_sync_memcg(struct user_beancounter *ub) struct cgroup_subsys_state *css; css = ub_get_mem_css(ub); - mem_cgroup_sync_beancounter(mem_cgroup_from_cont(css->cgroup), ub); - css_put(css); + if (css) { + mem_cgroup_sync_beancounter(mem_cgroup_from_cont(css->cgroup), ub); + css_put(css); + } } unsigned long ub_total_pages(struct user_beancounter *ub, bool swap) { struct cgroup_subsys_state *css; - unsigned long ret; + unsigned long ret = 0; css = ub_get_mem_css(ub); - ret = mem_cgroup_total_pages(mem_cgroup_from_cont(css->cgroup), swap); - css_put(css); + if (css) { + ret = mem_cgroup_total_pages(mem_cgroup_from_cont(css->cgroup), swap); + css_put(css); + } return ret; } @@ -576,11 +605,12 @@ static ssize_t ub_cgroup_read(struct cgroup *cg, struct cftype *cft, struct cgroup_subsys_state *bound_css; char *path; int len; - ssize_t ret; + ssize_t ret = -ENOMEM; bound_css = __ub_get_css(ub, cft->private); + if (!bound_css) + goto fail; - ret = -ENOMEM; path = kmalloc(PATH_MAX + 1, GFP_KERNEL); if (!path) goto out; @@ -594,6 +624,7 @@ static ssize_t ub_cgroup_read(struct cgroup *cg, struct cftype *cft, kfree(path); out: css_put(bound_css); +fail: return ret; } diff --git a/kernel/bc/io_prio.c b/kernel/bc/io_prio.c index 16f5024..01a6251 100644 --- a/kernel/bc/io_prio.c +++ b/kernel/bc/io_prio.c @@ -35,8 +35,12 @@ int ub_set_ioprio(int id, int ioprio) goto out; css = ub_get_blkio_css(ub); + if (!css) + goto put; + ret = blkcg_set_weight(css->cgroup, ioprio_weight[ioprio]); css_put(css); +put: put_beancounter(ub); out: return ret; @@ -59,8 +63,10 @@ static int bc_iostat(struct seq_file *f, struct user_beancounter *bc) __ub_percpu_sum(bc, fuse_bytes) >> 9); css = ub_get_blkio_css(bc); - blkcg_show_ub_iostat(css->cgroup, f); - css_put(css); + if (css) { + blkcg_show_ub_iostat(css->cgroup, f); + css_put(css); + } return 0; } @@ -146,6 +152,9 @@ static int bc_ioprio_show(struct seq_file *f, void *v) bc = seq_beancounter(f); css = ub_get_blkio_css(bc); + if (!css) + return 0; + weight = blkcg_get_weight(css->cgroup); css_put(css); diff --git a/kernel/bc/proc.c b/kernel/bc/proc.c index efcfdbc..2251d6d 100644 --- a/kernel/bc/proc.c +++ b/kernel/bc/proc.c @@ -144,6 +144,9 @@ static int bc_proc_nodeinfo_show(struct seq_file *f, void *v) unsigned long pages[NR_LRU_LISTS]; css = ub_get_mem_css(seq_beancounter(f)); + if (!css) + return 0; + for_each_node_state(nid, N_HIGH_MEMORY) { memset(pages, 0, sizeof(pages)); mem_cgroup_get_nr_pages(mem_cgroup_from_cont(css->cgroup), diff --git a/kernel/bc/vm_pages.c b/kernel/bc/vm_pages.c index e5019c0..7952da1 100644 --- a/kernel/bc/vm_pages.c +++ b/kernel/bc/vm_pages.c @@ -127,7 +127,7 @@ int ub_enough_memory(struct mm_struct *mm, long pages) struct user_beancounter *ub; struct cgroup_subsys_state *css; unsigned long flags; - int ret; + int ret = -ENOMEM; if (!mm) return 0; @@ -135,15 +135,16 @@ int ub_enough_memory(struct mm_struct *mm, long pages) ub = mm->mm_ub; if (ub->ub_parms[UB_PRIVVMPAGES].held > - ub->ub_parms[UB_PRIVVMPAGES].barrier) { - ret = -ENOMEM; + ub->ub_parms[UB_PRIVVMPAGES].barrier) goto out; - } if (ub == get_ub0() || ub_overcommit_memory) return 0; css = ub_get_mem_css(ub); + if (!css) + goto out; + ret = mem_cgroup_enough_memory(mem_cgroup_from_cont(css->cgroup), pages); css_put(css); out: @@ -166,6 +167,9 @@ static int bc_fill_sysinfo(struct user_beancounter *ub, return NOTIFY_DONE | NOTIFY_STOP_MASK; css = ub_get_mem_css(ub); + if (!css) + return NOTIFY_BAD; + mem_cgroup_fill_sysinfo(mem_cgroup_from_cont(css->cgroup), si); css_put(css); @@ -185,6 +189,9 @@ static int bc_fill_meminfo(struct user_beancounter *ub, goto out; css = ub_get_mem_css(ub); + if (!css) + return NOTIFY_BAD; + mem_cgroup_fill_meminfo(mem_cgroup_from_cont(css->cgroup), mi); css_put(css); @@ -213,6 +220,9 @@ static int bc_fill_vmstat(struct user_beancounter *ub, unsigned long *stat) return NOTIFY_OK; css = ub_get_mem_css(ub); + if (!css) + return NOTIFY_BAD; + mem_cgroup_fill_vmstat(mem_cgroup_from_cont(css->cgroup), stat); css_put(css); return NOTIFY_OK; 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