bcachefs: simplify gc locking a bit

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

diff --git a/fs/bcachefs/btree_gc.c b/fs/bcachefs/btree_gc.c
index aa8ac7d661ee4435439f9748b5ead79d8ff3d444..5abd7ac5bb78a8fc5ccea132fda843127d8478ac 100644 (file)
--- a/fs/bcachefs/btree_gc.c
+++ b/fs/bcachefs/btree_gc.c
@@ -480,12 +480,8 @@ static void bch2_gc_free(struct bch_fs *c)
                ca->usage[1] = NULL;
        }
 
-       percpu_down_write(&c->mark_lock);
-
        free_percpu(c->usage[1]);
        c->usage[1] = NULL;
-
-       percpu_up_write(&c->mark_lock);
 }
 
 static void bch2_gc_done(struct bch_fs *c, bool initial)
@@ -526,8 +522,6 @@ static void bch2_gc_done(struct bch_fs *c, bool initial)
 #define copy_fs_field(_f, _msg, ...)                                   \
        copy_field(_f, "fs has wrong " _msg, ##__VA_ARGS__)
 
-       percpu_down_write(&c->mark_lock);
-
        {
                struct genradix_iter dst_iter = genradix_iter_init(&c->stripes[0], 0);
                struct genradix_iter src_iter = genradix_iter_init(&c->stripes[1], 0);
@@ -635,8 +629,6 @@ static void bch2_gc_done(struct bch_fs *c, bool initial)
                }
        }
 
-       percpu_up_write(&c->mark_lock);
-
 #undef copy_fs_field
 #undef copy_dev_field
 #undef copy_bucket_field
@@ -649,8 +641,6 @@ static int bch2_gc_start(struct bch_fs *c)
        struct bch_dev *ca;
        unsigned i;
 
-       percpu_down_write(&c->mark_lock);
-
        /*
         * indicate to stripe code that we need to allocate for the gc stripes
         * radix tree, too
@@ -661,8 +651,6 @@ static int bch2_gc_start(struct bch_fs *c)
 
        c->usage[1] = __alloc_percpu_gfp(fs_usage_u64s(c) * sizeof(u64),
                                         sizeof(u64), GFP_KERNEL);
-       percpu_up_write(&c->mark_lock);
-
        if (!c->usage[1])
                return -ENOMEM;
 
@@ -685,8 +673,6 @@ static int bch2_gc_start(struct bch_fs *c)
                }
        }
 
-       percpu_down_write(&c->mark_lock);
-
        for_each_member_device(ca, c, i) {
                struct bucket_array *dst = __bucket_array(ca, 1);
                struct bucket_array *src = __bucket_array(ca, 0);
@@ -703,8 +689,6 @@ static int bch2_gc_start(struct bch_fs *c)
                }
        };
 
-       percpu_up_write(&c->mark_lock);
-
        return bch2_ec_mem_alloc(c, true);
 }
 
@@ -737,7 +721,10 @@ int bch2_gc(struct bch_fs *c, struct list_head *journal, bool initial)
 
        down_write(&c->gc_lock);
 again:
+       percpu_down_write(&c->mark_lock);
        ret = bch2_gc_start(c);
+       percpu_up_write(&c->mark_lock);
+
        if (ret)
                goto out;
 
@@ -762,7 +749,11 @@ out:
                        bch_info(c, "Fixed gens, restarting mark and sweep:");
                        clear_bit(BCH_FS_FIXED_GENS, &c->flags);
                        __gc_pos_set(c, gc_phase(GC_PHASE_NOT_RUNNING));
+
+                       percpu_down_write(&c->mark_lock);
                        bch2_gc_free(c);
+                       percpu_up_write(&c->mark_lock);
+
                        goto again;
                }
 
@@ -770,6 +761,8 @@ out:
                ret = -EINVAL;
        }
 
+       percpu_down_write(&c->mark_lock);
+
        if (!ret)
                bch2_gc_done(c, initial);
 
@@ -777,6 +770,8 @@ out:
        __gc_pos_set(c, gc_phase(GC_PHASE_NOT_RUNNING));
 
        bch2_gc_free(c);
+       percpu_up_write(&c->mark_lock);
+
        up_write(&c->gc_lock);
 
        trace_gc_end(c);