nfsd: fix leak on error in nfsv3 readdir
[safe/jmp/linux-2.6] / mm / memcontrol.c
index 2fc6d6c..fd4529d 100644 (file)
@@ -45,7 +45,7 @@ struct cgroup_subsys mem_cgroup_subsys __read_mostly;
 #define MEM_CGROUP_RECLAIM_RETRIES     5
 
 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
-/* Turned on only when memory cgroup is enabled && really_do_swap_account = 0 */
+/* Turned on only when memory cgroup is enabled && really_do_swap_account = 1 */
 int do_swap_account __read_mostly;
 static int really_do_swap_account __initdata = 1; /* for remember boot option*/
 #else
@@ -62,7 +62,8 @@ enum mem_cgroup_stat_index {
         * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
         */
        MEM_CGROUP_STAT_CACHE,     /* # of pages charged as cache */
-       MEM_CGROUP_STAT_RSS,       /* # of pages charged as rss */
+       MEM_CGROUP_STAT_RSS,       /* # of pages charged as anon rss */
+       MEM_CGROUP_STAT_MAPPED_FILE,  /* # of pages charged as file rss */
        MEM_CGROUP_STAT_PGPGIN_COUNT,   /* # of pages paged in */
        MEM_CGROUP_STAT_PGPGOUT_COUNT,  /* # of pages paged out */
 
@@ -176,6 +177,9 @@ struct mem_cgroup {
 
        unsigned int    swappiness;
 
+       /* set when res.limit == memsw.limit */
+       bool            memsw_is_minimum;
+
        /*
         * statistics. This must be placed at the end of memcg.
         */
@@ -188,6 +192,7 @@ enum charge_type {
        MEM_CGROUP_CHARGE_TYPE_SHMEM,   /* used by page migration of shmem */
        MEM_CGROUP_CHARGE_TYPE_FORCE,   /* used by force_empty */
        MEM_CGROUP_CHARGE_TYPE_SWAPOUT, /* for accounting swapcache */
+       MEM_CGROUP_CHARGE_TYPE_DROP,    /* a page was unused swap cache */
        NR_CHARGE_TYPE,
 };
 
@@ -314,14 +319,6 @@ static struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)
        return mem;
 }
 
-static bool mem_cgroup_is_obsolete(struct mem_cgroup *mem)
-{
-       if (!mem)
-               return true;
-       return css_is_removed(&mem->css);
-}
-
-
 /*
  * Call callback function against all cgroup under hierarchy tree.
  */
@@ -578,6 +575,17 @@ int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg)
        return 0;
 }
 
+int mem_cgroup_inactive_file_is_low(struct mem_cgroup *memcg)
+{
+       unsigned long active;
+       unsigned long inactive;
+
+       inactive = mem_cgroup_get_local_zonestat(memcg, LRU_INACTIVE_FILE);
+       active = mem_cgroup_get_local_zonestat(memcg, LRU_ACTIVE_FILE);
+
+       return (active > inactive);
+}
+
 unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup *memcg,
                                       struct zone *zone,
                                       enum lru_list lru)
@@ -641,6 +649,7 @@ unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
        int zid = zone_idx(z);
        struct mem_cgroup_per_zone *mz;
        int lru = LRU_FILE * !!file + !!active;
+       int ret;
 
        BUG_ON(!mem_cont);
        mz = mem_cgroup_zoneinfo(mem_cont, nid, zid);
@@ -658,9 +667,19 @@ unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
                        continue;
 
                scan++;
-               if (__isolate_lru_page(page, mode, file) == 0) {
+               ret = __isolate_lru_page(page, mode, file);
+               switch (ret) {
+               case 0:
                        list_move(&page->lru, dst);
+                       mem_cgroup_del_lru(page);
                        nr_taken++;
+                       break;
+               case -EBUSY:
+                       /* we don't affect global LRU but rotate in our LRU */
+                       mem_cgroup_rotate_lru_list(page, page_lru(page));
+                       break;
+               default:
+                       break;
                }
        }
 
@@ -842,6 +861,10 @@ static int mem_cgroup_hierarchical_reclaim(struct mem_cgroup *root_mem,
        int ret, total = 0;
        int loop = 0;
 
+       /* If memsw_is_minimum==1, swap-out is of-no-use. */
+       if (root_mem->memsw_is_minimum)
+               noswap = true;
+
        while (loop < 2) {
                victim = mem_cgroup_select_victim(root_mem);
                if (victim == root_mem)
@@ -897,6 +920,44 @@ static void record_last_oom(struct mem_cgroup *mem)
        mem_cgroup_walk_tree(mem, NULL, record_last_oom_cb);
 }
 
+/*
+ * Currently used to update mapped file statistics, but the routine can be
+ * generalized to update other statistics as well.
+ */
+void mem_cgroup_update_mapped_file_stat(struct page *page, int val)
+{
+       struct mem_cgroup *mem;
+       struct mem_cgroup_stat *stat;
+       struct mem_cgroup_stat_cpu *cpustat;
+       int cpu;
+       struct page_cgroup *pc;
+
+       if (!page_is_file_cache(page))
+               return;
+
+       pc = lookup_page_cgroup(page);
+       if (unlikely(!pc))
+               return;
+
+       lock_page_cgroup(pc);
+       mem = pc->mem_cgroup;
+       if (!mem)
+               goto done;
+
+       if (!PageCgroupUsed(pc))
+               goto done;
+
+       /*
+        * Preemption is already disabled, we don't need get_cpu()
+        */
+       cpu = smp_processor_id();
+       stat = &mem->stat;
+       cpustat = &stat->cpustat[cpu];
+
+       __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_MAPPED_FILE, val);
+done:
+       unlock_page_cgroup(pc);
+}
 
 /*
  * Unlike exported interface, "oom" parameter is added. if oom==true,
@@ -932,7 +993,7 @@ static int __mem_cgroup_try_charge(struct mm_struct *mm,
        if (unlikely(!mem))
                return 0;
 
-       VM_BUG_ON(mem_cgroup_is_obsolete(mem));
+       VM_BUG_ON(css_is_removed(&mem->css));
 
        while (1) {
                int ret;
@@ -1024,9 +1085,7 @@ static struct mem_cgroup *try_get_mem_cgroup_from_swapcache(struct page *page)
                return NULL;
 
        pc = lookup_page_cgroup(page);
-       /*
-        * Used bit of swapcache is solid under page lock.
-        */
+       lock_page_cgroup(pc);
        if (PageCgroupUsed(pc)) {
                mem = pc->mem_cgroup;
                if (mem && !css_tryget(&mem->css))
@@ -1040,6 +1099,7 @@ static struct mem_cgroup *try_get_mem_cgroup_from_swapcache(struct page *page)
                        mem = NULL;
                rcu_read_unlock();
        }
+       unlock_page_cgroup(pc);
        return mem;
 }
 
@@ -1096,6 +1156,10 @@ static int mem_cgroup_move_account(struct page_cgroup *pc,
        struct mem_cgroup_per_zone *from_mz, *to_mz;
        int nid, zid;
        int ret = -EBUSY;
+       struct page *page;
+       int cpu;
+       struct mem_cgroup_stat *stat;
+       struct mem_cgroup_stat_cpu *cpustat;
 
        VM_BUG_ON(from == to);
        VM_BUG_ON(PageLRU(pc->page));
@@ -1116,6 +1180,23 @@ static int mem_cgroup_move_account(struct page_cgroup *pc,
 
        res_counter_uncharge(&from->res, PAGE_SIZE);
        mem_cgroup_charge_statistics(from, pc, false);
+
+       page = pc->page;
+       if (page_is_file_cache(page) && page_mapped(page)) {
+               cpu = smp_processor_id();
+               /* Update mapped_file data for mem_cgroup "from" */
+               stat = &from->stat;
+               cpustat = &stat->cpustat[cpu];
+               __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_MAPPED_FILE,
+                                               -1);
+
+               /* Update mapped_file data for mem_cgroup "to" */
+               stat = &to->stat;
+               cpustat = &stat->cpustat[cpu];
+               __mem_cgroup_stat_add_safe(cpustat, MEM_CGROUP_STAT_MAPPED_FILE,
+                                               1);
+       }
+
        if (do_swap_account)
                res_counter_uncharge(&from->memsw, PAGE_SIZE);
        css_put(&from->css);
@@ -1126,6 +1207,12 @@ static int mem_cgroup_move_account(struct page_cgroup *pc,
        ret = 0;
 out:
        unlock_page_cgroup(pc);
+       /*
+        * We charges against "to" which may not have any tasks. Then, "to"
+        * can be under rmdir(). But in current implementation, caller of
+        * this function is just force_empty() and it's garanteed that
+        * "to" is never removed. So, we don't check rmdir status here.
+        */
        return ret;
 }
 
@@ -1347,6 +1434,7 @@ __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
                return;
        if (!ptr)
                return;
+       cgroup_exclude_rmdir(&ptr->css);
        pc = lookup_page_cgroup(page);
        mem_cgroup_lru_del_before_commit_swapcache(page);
        __mem_cgroup_commit_charge(ptr, pc, ctype);
@@ -1376,8 +1464,12 @@ __mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr,
                }
                rcu_read_unlock();
        }
-       /* add this page(page_cgroup) to the LRU we want. */
-
+       /*
+        * At swapin, we may charge account against cgroup which has no tasks.
+        * So, rmdir()->pre_destroy() can be called while we do this charge.
+        * In that case, we need to call pre_destroy() again. check it here.
+        */
+       cgroup_release_and_wakeup_rmdir(&ptr->css);
 }
 
 void mem_cgroup_commit_charge_swapin(struct page *page, struct mem_cgroup *ptr)
@@ -1431,6 +1523,7 @@ __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
 
        switch (ctype) {
        case MEM_CGROUP_CHARGE_TYPE_MAPPED:
+       case MEM_CGROUP_CHARGE_TYPE_DROP:
                if (page_mapped(page))
                        goto unlock_out;
                break;
@@ -1489,24 +1582,31 @@ void mem_cgroup_uncharge_cache_page(struct page *page)
        __mem_cgroup_uncharge_common(page, MEM_CGROUP_CHARGE_TYPE_CACHE);
 }
 
+#ifdef CONFIG_SWAP
 /*
- * called from __delete_from_swap_cache() and drop "page" account.
+ * called after __delete_from_swap_cache() and drop "page" account.
  * memcg information is recorded to swap_cgroup of "ent"
  */
-void mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent)
+void
+mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout)
 {
        struct mem_cgroup *memcg;
+       int ctype = MEM_CGROUP_CHARGE_TYPE_SWAPOUT;
+
+       if (!swapout) /* this was a swap cache but the swap is unused ! */
+               ctype = MEM_CGROUP_CHARGE_TYPE_DROP;
+
+       memcg = __mem_cgroup_uncharge_common(page, ctype);
 
-       memcg = __mem_cgroup_uncharge_common(page,
-                                       MEM_CGROUP_CHARGE_TYPE_SWAPOUT);
        /* record memcg information */
-       if (do_swap_account && memcg) {
+       if (do_swap_account && swapout && memcg) {
                swap_cgroup_record(ent, css_id(&memcg->css));
                mem_cgroup_get(memcg);
        }
-       if (memcg)
+       if (swapout && memcg)
                css_put(&memcg->css);
 }
+#endif
 
 #ifdef CONFIG_CGROUP_MEM_RES_CTLR_SWAP
 /*
@@ -1575,7 +1675,7 @@ void mem_cgroup_end_migration(struct mem_cgroup *mem,
 
        if (!mem)
                return;
-
+       cgroup_exclude_rmdir(&mem->css);
        /* at migration success, oldpage->mapping is NULL. */
        if (oldpage->mapping) {
                target = oldpage;
@@ -1615,40 +1715,37 @@ void mem_cgroup_end_migration(struct mem_cgroup *mem,
         */
        if (ctype == MEM_CGROUP_CHARGE_TYPE_MAPPED)
                mem_cgroup_uncharge_page(target);
+       /*
+        * At migration, we may charge account against cgroup which has no tasks
+        * So, rmdir()->pre_destroy() can be called while we do this charge.
+        * In that case, we need to call pre_destroy() again. check it here.
+        */
+       cgroup_release_and_wakeup_rmdir(&mem->css);
 }
 
 /*
- * A call to try to shrink memory usage under specified resource controller.
- * This is typically used for page reclaiming for shmem for reducing side
- * effect of page allocation from shmem, which is used by some mem_cgroup.
+ * A call to try to shrink memory usage on charge failure at shmem's swapin.
+ * Calling hierarchical_reclaim is not enough because we should update
+ * last_oom_jiffies to prevent pagefault_out_of_memory from invoking global OOM.
+ * Moreover considering hierarchy, we should reclaim from the mem_over_limit,
+ * not from the memcg which this page would be charged to.
+ * try_charge_swapin does all of these works properly.
  */
-int mem_cgroup_shrink_usage(struct page *page,
+int mem_cgroup_shmem_charge_fallback(struct page *page,
                            struct mm_struct *mm,
                            gfp_t gfp_mask)
 {
        struct mem_cgroup *mem = NULL;
-       int progress = 0;
-       int retry = MEM_CGROUP_RECLAIM_RETRIES;
+       int ret;
 
        if (mem_cgroup_disabled())
                return 0;
-       if (page)
-               mem = try_get_mem_cgroup_from_swapcache(page);
-       if (!mem && mm)
-               mem = try_get_mem_cgroup_from_mm(mm);
-       if (unlikely(!mem))
-               return 0;
 
-       do {
-               progress = mem_cgroup_hierarchical_reclaim(mem,
-                                       gfp_mask, true, false);
-               progress += mem_cgroup_check_under_limit(mem);
-       } while (!progress && --retry);
+       ret = mem_cgroup_try_charge_swapin(mm, page, gfp_mask, &mem);
+       if (!ret)
+               mem_cgroup_cancel_charge_swapin(mem); /* it does !mem check */
 
-       css_put(&mem->css);
-       if (!retry)
-               return -ENOMEM;
-       return 0;
+       return ret;
 }
 
 static DEFINE_MUTEX(set_limit_mutex);
@@ -1690,6 +1787,12 @@ static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
                        break;
                }
                ret = res_counter_set_limit(&memcg->res, val);
+               if (!ret) {
+                       if (memswlimit == val)
+                               memcg->memsw_is_minimum = true;
+                       else
+                               memcg->memsw_is_minimum = false;
+               }
                mutex_unlock(&set_limit_mutex);
 
                if (!ret)
@@ -1708,16 +1811,14 @@ static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,
        return ret;
 }
 
-int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
-                               unsigned long long val)
+static int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
+                                       unsigned long long val)
 {
        int retry_count;
        u64 memlimit, oldusage, curusage;
        int children = mem_cgroup_count_children(memcg);
        int ret = -EBUSY;
 
-       if (!do_swap_account)
-               return -EINVAL;
        /* see mem_cgroup_resize_res_limit */
        retry_count = children * MEM_CGROUP_RECLAIM_RETRIES;
        oldusage = res_counter_read_u64(&memcg->memsw, RES_USAGE);
@@ -1739,6 +1840,12 @@ int mem_cgroup_resize_memsw_limit(struct mem_cgroup *memcg,
                        break;
                }
                ret = res_counter_set_limit(&memcg->memsw, val);
+               if (!ret) {
+                       if (memlimit == val)
+                               memcg->memsw_is_minimum = true;
+                       else
+                               memcg->memsw_is_minimum = false;
+               }
                mutex_unlock(&set_limit_mutex);
 
                if (!ret)
@@ -1883,7 +1990,7 @@ try_to_free:
                if (!progress) {
                        nr_retries--;
                        /* maybe some writeback is necessary */
-                       congestion_wait(WRITE, HZ/10);
+                       congestion_wait(BLK_RW_ASYNC, HZ/10);
                }
 
        }
@@ -1952,8 +2059,7 @@ static u64 mem_cgroup_read(struct cgroup *cont, struct cftype *cft)
                val = res_counter_read_u64(&mem->res, name);
                break;
        case _MEMSWAP:
-               if (do_swap_account)
-                       val = res_counter_read_u64(&mem->memsw, name);
+               val = res_counter_read_u64(&mem->memsw, name);
                break;
        default:
                BUG();
@@ -2051,6 +2157,7 @@ static int mem_cgroup_reset(struct cgroup *cont, unsigned int event)
 enum {
        MCS_CACHE,
        MCS_RSS,
+       MCS_MAPPED_FILE,
        MCS_PGPGIN,
        MCS_PGPGOUT,
        MCS_INACTIVE_ANON,
@@ -2071,6 +2178,7 @@ struct {
 } memcg_stat_strings[NR_MCS_STAT] = {
        {"cache", "total_cache"},
        {"rss", "total_rss"},
+       {"mapped_file", "total_mapped_file"},
        {"pgpgin", "total_pgpgin"},
        {"pgpgout", "total_pgpgout"},
        {"inactive_anon", "total_inactive_anon"},
@@ -2091,6 +2199,8 @@ static int mem_cgroup_get_local_stat(struct mem_cgroup *mem, void *data)
        s->stat[MCS_CACHE] += val * PAGE_SIZE;
        val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_RSS);
        s->stat[MCS_RSS] += val * PAGE_SIZE;
+       val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_MAPPED_FILE);
+       s->stat[MCS_MAPPED_FILE] += val * PAGE_SIZE;
        val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_PGPGIN_COUNT);
        s->stat[MCS_PGPGIN] += val;
        val = mem_cgroup_read_stat(&mem->stat, MEM_CGROUP_STAT_PGPGOUT_COUNT);