bcachefs: Switch replicas to mark_lock

Prep work for upcoming disk accounting changes

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

diff --git a/fs/bcachefs/bcachefs.h b/fs/bcachefs/bcachefs.h
index 829b2c8b067b97a747d438e2e8c16909fbd0dc0a..512498c275a5bab6a9f1599e7d09096005264c05 100644 (file)
--- a/fs/bcachefs/bcachefs.h
+++ b/fs/bcachefs/bcachefs.h
@@ -528,8 +528,8 @@ struct bch_fs {
 
        struct bch_dev __rcu    *devs[BCH_SB_MEMBERS_MAX];
 
-       struct bch_replicas_cpu __rcu *replicas;
-       struct bch_replicas_cpu __rcu *replicas_gc;
+       struct bch_replicas_cpu replicas;
+       struct bch_replicas_cpu replicas_gc;
        struct mutex            replicas_gc_lock;
 
        struct bch_disk_groups_cpu __rcu *disk_groups;

diff --git a/fs/bcachefs/recovery.c b/fs/bcachefs/recovery.c
index 2d0736caa5efd006df19b9bfce5c2cd11a156ee8..cfdf9b5636375c8e06f486d873674556a04064ac 100644 (file)
--- a/fs/bcachefs/recovery.c
+++ b/fs/bcachefs/recovery.c
@@ -131,8 +131,7 @@ int bch2_fs_recovery(struct bch_fs *c)
        int ret;
 
        mutex_lock(&c->sb_lock);
-       if (!rcu_dereference_protected(c->replicas,
-                       lockdep_is_held(&c->sb_lock))->nr) {
+       if (!c->replicas.entries) {
                bch_info(c, "building replicas info");
                set_bit(BCH_FS_REBUILD_REPLICAS, &c->flags);
        }

diff --git a/fs/bcachefs/replicas.c b/fs/bcachefs/replicas.c
index 77d175f34b2b2eddd0a515990128ed86f5911ab0..a694b0fcd6a15847999c2cdfe4925f75f8f71867 100644 (file)
--- a/fs/bcachefs/replicas.c
+++ b/fs/bcachefs/replicas.c
@@ -149,35 +149,31 @@ static inline void devlist_to_replicas(struct bch_devs_list devs,
        replicas_entry_sort(e);
 }
 
-static struct bch_replicas_cpu *
+static struct bch_replicas_cpu
 cpu_replicas_add_entry(struct bch_replicas_cpu *old,
                       struct bch_replicas_entry *new_entry)
 {
-       struct bch_replicas_cpu *new;
-       unsigned i, nr, entry_size;
-
-       entry_size = max_t(unsigned, old->entry_size,
-                          replicas_entry_bytes(new_entry));
-       nr = old->nr + 1;
-
-       new = kzalloc(sizeof(struct bch_replicas_cpu) +
-                     nr * entry_size, GFP_NOIO);
-       if (!new)
-               return NULL;
+       unsigned i;
+       struct bch_replicas_cpu new = {
+               .nr             = old->nr + 1,
+               .entry_size     = max_t(unsigned, old->entry_size,
+                                       replicas_entry_bytes(new_entry)),
+       };
 
-       new->nr         = nr;
-       new->entry_size = entry_size;
+       new.entries = kcalloc(new.nr, new.entry_size, GFP_NOIO);
+       if (!new.entries)
+               return new;
 
        for (i = 0; i < old->nr; i++)
-               memcpy(cpu_replicas_entry(new, i),
+               memcpy(cpu_replicas_entry(&new, i),
                       cpu_replicas_entry(old, i),
                       old->entry_size);
 
-       memcpy(cpu_replicas_entry(new, old->nr),
+       memcpy(cpu_replicas_entry(&new, old->nr),
               new_entry,
               replicas_entry_bytes(new_entry));
 
-       bch2_cpu_replicas_sort(new);
+       bch2_cpu_replicas_sort(&new);
        return new;
 }
 
@@ -194,16 +190,14 @@ static bool replicas_has_entry(struct bch_fs *c,
                               struct bch_replicas_entry *search,
                               bool check_gc_replicas)
 {
-       struct bch_replicas_cpu *r, *gc_r;
        bool marked;
 
-       rcu_read_lock();
-       r = rcu_dereference(c->replicas);
-       marked = __replicas_has_entry(r, search) &&
+       percpu_down_read(&c->mark_lock);
+       marked = __replicas_has_entry(&c->replicas, search) &&
                (!check_gc_replicas ||
-                likely(!(gc_r = rcu_dereference(c->replicas_gc))) ||
-                __replicas_has_entry(gc_r, search));
-       rcu_read_unlock();
+                likely((!c->replicas_gc.entries)) ||
+                __replicas_has_entry(&c->replicas_gc, search));
+       percpu_up_read(&c->mark_lock);
 
        return marked;
 }
@@ -212,54 +206,55 @@ noinline
 static int bch2_mark_replicas_slowpath(struct bch_fs *c,
                                struct bch_replicas_entry *new_entry)
 {
-       struct bch_replicas_cpu *old_gc, *new_gc = NULL, *old_r, *new_r = NULL;
+       struct bch_replicas_cpu new_r, new_gc;
        int ret = -ENOMEM;
 
+       memset(&new_r, 0, sizeof(new_r));
+       memset(&new_gc, 0, sizeof(new_gc));
+
        mutex_lock(&c->sb_lock);
 
-       old_gc = rcu_dereference_protected(c->replicas_gc,
-                                          lockdep_is_held(&c->sb_lock));
-       if (old_gc && !__replicas_has_entry(old_gc, new_entry)) {
-               new_gc = cpu_replicas_add_entry(old_gc, new_entry);
-               if (!new_gc)
+       if (c->replicas_gc.entries &&
+           !__replicas_has_entry(&c->replicas_gc, new_entry)) {
+               new_gc = cpu_replicas_add_entry(&c->replicas_gc, new_entry);
+               if (!new_gc.entries)
                        goto err;
        }
 
-       old_r = rcu_dereference_protected(c->replicas,
-                                         lockdep_is_held(&c->sb_lock));
-       if (!__replicas_has_entry(old_r, new_entry)) {
-               new_r = cpu_replicas_add_entry(old_r, new_entry);
-               if (!new_r)
+       if (!__replicas_has_entry(&c->replicas, new_entry)) {
+               new_r = cpu_replicas_add_entry(&c->replicas, new_entry);
+               if (!new_r.entries)
                        goto err;
 
-               ret = bch2_cpu_replicas_to_sb_replicas(c, new_r);
+               ret = bch2_cpu_replicas_to_sb_replicas(c, &new_r);
                if (ret)
                        goto err;
        }
 
+       if (!new_r.entries &&
+           !new_gc.entries)
+               goto out;
+
        /* allocations done, now commit: */
 
-       if (new_r)
+       if (new_r.entries)
                bch2_write_super(c);
 
        /* don't update in memory replicas until changes are persistent */
-
-       if (new_gc) {
-               rcu_assign_pointer(c->replicas_gc, new_gc);
-               kfree_rcu(old_gc, rcu);
-       }
-
-       if (new_r) {
-               rcu_assign_pointer(c->replicas, new_r);
-               kfree_rcu(old_r, rcu);
-       }
-
-       mutex_unlock(&c->sb_lock);
-       return 0;
+       percpu_down_write(&c->mark_lock);
+       if (new_r.entries)
+               swap(new_r, c->replicas);
+       if (new_gc.entries)
+               swap(new_gc, c->replicas_gc);
+       percpu_up_write(&c->mark_lock);
+out:
+       ret = 0;
 err:
        mutex_unlock(&c->sb_lock);
-       kfree(new_gc);
-       kfree(new_r);
+
+       kfree(new_r.entries);
+       kfree(new_gc.entries);
+
        return ret;
 }
 
@@ -312,20 +307,14 @@ int bch2_mark_bkey_replicas(struct bch_fs *c, struct bkey_s_c k)
 
 int bch2_replicas_gc_end(struct bch_fs *c, int ret)
 {
-       struct bch_replicas_cpu *new_r, *old_r;
-
        lockdep_assert_held(&c->replicas_gc_lock);
 
        mutex_lock(&c->sb_lock);
 
-       new_r = rcu_dereference_protected(c->replicas_gc,
-                                         lockdep_is_held(&c->sb_lock));
-       rcu_assign_pointer(c->replicas_gc, NULL);
-
        if (ret)
                goto err;
 
-       if (bch2_cpu_replicas_to_sb_replicas(c, new_r)) {
+       if (bch2_cpu_replicas_to_sb_replicas(c, &c->replicas_gc)) {
                ret = -ENOSPC;
                goto err;
        }
@@ -333,51 +322,54 @@ int bch2_replicas_gc_end(struct bch_fs *c, int ret)
        bch2_write_super(c);
 
        /* don't update in memory replicas until changes are persistent */
+err:
+       percpu_down_write(&c->mark_lock);
+       if (!ret)
+               swap(c->replicas, c->replicas_gc);
 
-       old_r = rcu_dereference_protected(c->replicas,
-                                         lockdep_is_held(&c->sb_lock));
+       kfree(c->replicas_gc.entries);
+       c->replicas_gc.entries = NULL;
+       percpu_up_write(&c->mark_lock);
 
-       rcu_assign_pointer(c->replicas, new_r);
-       kfree_rcu(old_r, rcu);
-out:
        mutex_unlock(&c->sb_lock);
        return ret;
-err:
-       kfree_rcu(new_r, rcu);
-       goto out;
 }
 
 int bch2_replicas_gc_start(struct bch_fs *c, unsigned typemask)
 {
-       struct bch_replicas_cpu *dst, *src;
        struct bch_replicas_entry *e;
+       unsigned i = 0;
 
        lockdep_assert_held(&c->replicas_gc_lock);
 
        mutex_lock(&c->sb_lock);
-       BUG_ON(c->replicas_gc);
+       BUG_ON(c->replicas_gc.entries);
 
-       src = rcu_dereference_protected(c->replicas,
-                                       lockdep_is_held(&c->sb_lock));
+       c->replicas_gc.nr               = 0;
+       c->replicas_gc.entry_size       = 0;
 
-       dst = kzalloc(sizeof(struct bch_replicas_cpu) +
-                     src->nr * src->entry_size, GFP_NOIO);
-       if (!dst) {
+       for_each_cpu_replicas_entry(&c->replicas, e)
+               if (!((1 << e->data_type) & typemask)) {
+                       c->replicas_gc.nr++;
+                       c->replicas_gc.entry_size =
+                               max_t(unsigned, c->replicas_gc.entry_size,
+                                     replicas_entry_bytes(e));
+               }
+
+       c->replicas_gc.entries = kcalloc(c->replicas_gc.nr,
+                                        c->replicas_gc.entry_size,
+                                        GFP_NOIO);
+       if (!c->replicas_gc.entries) {
                mutex_unlock(&c->sb_lock);
                return -ENOMEM;
        }
 
-       dst->nr         = 0;
-       dst->entry_size = src->entry_size;
-
-       for_each_cpu_replicas_entry(src, e)
+       for_each_cpu_replicas_entry(&c->replicas, e)
                if (!((1 << e->data_type) & typemask))
-                       memcpy(cpu_replicas_entry(dst, dst->nr++),
-                              e, dst->entry_size);
-
-       bch2_cpu_replicas_sort(dst);
+                       memcpy(cpu_replicas_entry(&c->replicas_gc, i++),
+                              e, c->replicas_gc.entry_size);
 
-       rcu_assign_pointer(c->replicas_gc, dst);
+       bch2_cpu_replicas_sort(&c->replicas_gc);
        mutex_unlock(&c->sb_lock);
 
        return 0;
@@ -385,11 +377,11 @@ int bch2_replicas_gc_start(struct bch_fs *c, unsigned typemask)
 
 /* Replicas tracking - superblock: */
 
-static struct bch_replicas_cpu *
-__bch2_sb_replicas_to_cpu_replicas(struct bch_sb_field_replicas *sb_r)
+static int
+__bch2_sb_replicas_to_cpu_replicas(struct bch_sb_field_replicas *sb_r,
+                                  struct bch_replicas_cpu *cpu_r)
 {
        struct bch_replicas_entry *e, *dst;
-       struct bch_replicas_cpu *cpu_r;
        unsigned nr = 0, entry_size = 0, idx = 0;
 
        for_each_replicas_entry(sb_r, e) {
@@ -398,10 +390,9 @@ __bch2_sb_replicas_to_cpu_replicas(struct bch_sb_field_replicas *sb_r)
                nr++;
        }
 
-       cpu_r = kzalloc(sizeof(struct bch_replicas_cpu) +
-                       nr * entry_size, GFP_NOIO);
-       if (!cpu_r)
-               return NULL;
+       cpu_r->entries = kcalloc(nr, entry_size, GFP_NOIO);
+       if (!cpu_r->entries)
+               return -ENOMEM;
 
        cpu_r->nr               = nr;
        cpu_r->entry_size       = entry_size;
@@ -412,14 +403,14 @@ __bch2_sb_replicas_to_cpu_replicas(struct bch_sb_field_replicas *sb_r)
                replicas_entry_sort(dst);
        }
 
-       return cpu_r;
+       return 0;
 }
 
-static struct bch_replicas_cpu *
-__bch2_sb_replicas_v0_to_cpu_replicas(struct bch_sb_field_replicas_v0 *sb_r)
+static int
+__bch2_sb_replicas_v0_to_cpu_replicas(struct bch_sb_field_replicas_v0 *sb_r,
+                                     struct bch_replicas_cpu *cpu_r)
 {
        struct bch_replicas_entry_v0 *e;
-       struct bch_replicas_cpu *cpu_r;
        unsigned nr = 0, entry_size = 0, idx = 0;
 
        for_each_replicas_entry(sb_r, e) {
@@ -431,10 +422,9 @@ __bch2_sb_replicas_v0_to_cpu_replicas(struct bch_sb_field_replicas_v0 *sb_r)
        entry_size += sizeof(struct bch_replicas_entry) -
                sizeof(struct bch_replicas_entry_v0);
 
-       cpu_r = kzalloc(sizeof(struct bch_replicas_cpu) +
-                       nr * entry_size, GFP_NOIO);
-       if (!cpu_r)
-               return NULL;
+       cpu_r->entries = kcalloc(nr, entry_size, GFP_NOIO);
+       if (!cpu_r->entries)
+               return -ENOMEM;
 
        cpu_r->nr               = nr;
        cpu_r->entry_size       = entry_size;
@@ -450,31 +440,31 @@ __bch2_sb_replicas_v0_to_cpu_replicas(struct bch_sb_field_replicas_v0 *sb_r)
                replicas_entry_sort(dst);
        }
 
-       return cpu_r;
+       return 0;
 }
 
 int bch2_sb_replicas_to_cpu_replicas(struct bch_fs *c)
 {
        struct bch_sb_field_replicas *sb_v1;
        struct bch_sb_field_replicas_v0 *sb_v0;
-       struct bch_replicas_cpu *cpu_r, *old_r;
+       struct bch_replicas_cpu new_r = { 0, 0, NULL };
+       int ret = 0;
 
        if ((sb_v1 = bch2_sb_get_replicas(c->disk_sb.sb)))
-               cpu_r = __bch2_sb_replicas_to_cpu_replicas(sb_v1);
+               ret = __bch2_sb_replicas_to_cpu_replicas(sb_v1, &new_r);
        else if ((sb_v0 = bch2_sb_get_replicas_v0(c->disk_sb.sb)))
-               cpu_r = __bch2_sb_replicas_v0_to_cpu_replicas(sb_v0);
-       else
-               cpu_r = kzalloc(sizeof(struct bch_replicas_cpu), GFP_NOIO);
+               ret = __bch2_sb_replicas_v0_to_cpu_replicas(sb_v0, &new_r);
 
-       if (!cpu_r)
+       if (ret)
                return -ENOMEM;
 
-       bch2_cpu_replicas_sort(cpu_r);
+       bch2_cpu_replicas_sort(&new_r);
+
+       percpu_down_write(&c->mark_lock);
+       swap(c->replicas, new_r);
+       percpu_up_write(&c->mark_lock);
 
-       old_r = rcu_dereference_check(c->replicas, lockdep_is_held(&c->sb_lock));
-       rcu_assign_pointer(c->replicas, cpu_r);
-       if (old_r)
-               kfree_rcu(old_r, rcu);
+       kfree(new_r.entries);
 
        return 0;
 }
@@ -589,7 +579,7 @@ static const char *bch2_sb_validate_replicas(struct bch_sb *sb, struct bch_sb_fi
 {
        struct bch_sb_field_replicas *sb_r = field_to_type(f, replicas);
        struct bch_sb_field_members *mi = bch2_sb_get_members(sb);
-       struct bch_replicas_cpu *cpu_r = NULL;
+       struct bch_replicas_cpu cpu_r = { .entries = NULL };
        struct bch_replicas_entry *e;
        const char *err;
        unsigned i;
@@ -616,13 +606,12 @@ static const char *bch2_sb_validate_replicas(struct bch_sb *sb, struct bch_sb_fi
        }
 
        err = "cannot allocate memory";
-       cpu_r = __bch2_sb_replicas_to_cpu_replicas(sb_r);
-       if (!cpu_r)
+       if (__bch2_sb_replicas_to_cpu_replicas(sb_r, &cpu_r))
                goto err;
 
-       err = check_dup_replicas_entries(cpu_r);
+       err = check_dup_replicas_entries(&cpu_r);
 err:
-       kfree(cpu_r);
+       kfree(cpu_r.entries);
        return err;
 }
 
@@ -652,7 +641,7 @@ static const char *bch2_sb_validate_replicas_v0(struct bch_sb *sb, struct bch_sb
 {
        struct bch_sb_field_replicas_v0 *sb_r = field_to_type(f, replicas_v0);
        struct bch_sb_field_members *mi = bch2_sb_get_members(sb);
-       struct bch_replicas_cpu *cpu_r = NULL;
+       struct bch_replicas_cpu cpu_r = { .entries = NULL };
        struct bch_replicas_entry_v0 *e;
        const char *err;
        unsigned i;
@@ -673,13 +662,12 @@ static const char *bch2_sb_validate_replicas_v0(struct bch_sb *sb, struct bch_sb
        }
 
        err = "cannot allocate memory";
-       cpu_r = __bch2_sb_replicas_v0_to_cpu_replicas(sb_r);
-       if (!cpu_r)
+       if (__bch2_sb_replicas_v0_to_cpu_replicas(sb_r, &cpu_r))
                goto err;
 
-       err = check_dup_replicas_entries(cpu_r);
+       err = check_dup_replicas_entries(&cpu_r);
 err:
-       kfree(cpu_r);
+       kfree(cpu_r.entries);
        return err;
 }
 
@@ -734,7 +722,6 @@ struct replicas_status __bch2_replicas_status(struct bch_fs *c,
 {
        struct bch_sb_field_members *mi;
        struct bch_replicas_entry *e;
-       struct bch_replicas_cpu *r;
        unsigned i, nr_online, nr_offline;
        struct replicas_status ret;
 
@@ -744,10 +731,10 @@ struct replicas_status __bch2_replicas_status(struct bch_fs *c,
                ret.replicas[i].redundancy = INT_MAX;
 
        mi = bch2_sb_get_members(c->disk_sb.sb);
-       rcu_read_lock();
-       r = rcu_dereference(c->replicas);
 
-       for_each_cpu_replicas_entry(r, e) {
+       percpu_down_read(&c->mark_lock);
+
+       for_each_cpu_replicas_entry(&c->replicas, e) {
                if (e->data_type >= ARRAY_SIZE(ret.replicas))
                        panic("e %p data_type %u\n", e, e->data_type);
 
@@ -772,7 +759,7 @@ struct replicas_status __bch2_replicas_status(struct bch_fs *c,
                            nr_offline);
        }
 
-       rcu_read_unlock();
+       percpu_up_read(&c->mark_lock);
 
        for (i = 0; i < ARRAY_SIZE(ret.replicas); i++)
                if (ret.replicas[i].redundancy == INT_MAX)
@@ -821,18 +808,16 @@ int bch2_replicas_online(struct bch_fs *c, bool meta)
 unsigned bch2_dev_has_data(struct bch_fs *c, struct bch_dev *ca)
 {
        struct bch_replicas_entry *e;
-       struct bch_replicas_cpu *r;
        unsigned i, ret = 0;
 
-       rcu_read_lock();
-       r = rcu_dereference(c->replicas);
+       percpu_down_read(&c->mark_lock);
 
-       for_each_cpu_replicas_entry(r, e)
+       for_each_cpu_replicas_entry(&c->replicas, e)
                for (i = 0; i < e->nr_devs; i++)
                        if (e->devs[i] == ca->dev_idx)
                                ret |= 1 << e->data_type;
 
-       rcu_read_unlock();
+       percpu_up_read(&c->mark_lock);
 
        return ret;
 }

diff --git a/fs/bcachefs/replicas_types.h b/fs/bcachefs/replicas_types.h
index 3061840b6a02bfb241b0bd01fcb764aa6c42a6e6..0535b1d3760edc1cdbc8284c44546f60f1ffb944 100644 (file)
--- a/fs/bcachefs/replicas_types.h
+++ b/fs/bcachefs/replicas_types.h
@@ -2,10 +2,9 @@
 #define _BCACHEFS_REPLICAS_TYPES_H
 
 struct bch_replicas_cpu {
-       struct rcu_head         rcu;
        unsigned                nr;
        unsigned                entry_size;
-       struct bch_replicas_entry entries[];
+       struct bch_replicas_entry *entries;
 };
 
 #endif /* _BCACHEFS_REPLICAS_TYPES_H */

diff --git a/fs/bcachefs/super.c b/fs/bcachefs/super.c
index cc14d43104364fc393dcdfa7f03184308ff23762..3887e63c075650a48e49b04c8a35f39750938062 100644 (file)
--- a/fs/bcachefs/super.c
+++ b/fs/bcachefs/super.c
@@ -383,7 +383,8 @@ static void bch2_fs_free(struct bch_fs *c)
        mempool_exit(&c->btree_reserve_pool);
        mempool_exit(&c->fill_iter);
        percpu_ref_exit(&c->writes);
-       kfree(rcu_dereference_protected(c->replicas, 1));
+       kfree(c->replicas.entries);
+       kfree(c->replicas_gc.entries);
        kfree(rcu_dereference_protected(c->disk_groups, 1));
 
        if (c->copygc_wq)
@@ -565,6 +566,9 @@ static struct bch_fs *bch2_fs_alloc(struct bch_sb *sb, struct bch_opts opts)
 
        bch2_fs_btree_cache_init_early(&c->btree_cache);
 
+       if (percpu_init_rwsem(&c->mark_lock))
+               goto err;
+
        mutex_lock(&c->sb_lock);
 
        if (bch2_sb_to_fs(c, sb)) {
@@ -608,7 +612,6 @@ static struct bch_fs *bch2_fs_alloc(struct bch_sb *sb, struct bch_opts opts)
                            offsetof(struct btree_write_bio, wbio.bio)),
                        BIOSET_NEED_BVECS) ||
            !(c->usage[0] = alloc_percpu(struct bch_fs_usage)) ||
-           percpu_init_rwsem(&c->mark_lock) ||
            mempool_init_kvpmalloc_pool(&c->btree_bounce_pool, 1,
                                        btree_bytes(c)) ||
            mempool_init_kmalloc_pool(&c->btree_iters_pool, 1,