bcachefs: Don't BUG_ON() on bucket sector count overflow

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

diff --git a/fs/bcachefs/buckets.c b/fs/bcachefs/buckets.c
index 5011e7af3563ecc1dcb708cacd410c7bcf5cf116..bddddcb93bc6c72c042dde72a9ac13411395927a 100644 (file)
--- a/fs/bcachefs/buckets.c
+++ b/fs/bcachefs/buckets.c
@@ -541,29 +541,40 @@ static int bch2_mark_alloc(struct bch_fs *c, struct bkey_s_c k,
 }
 
 #define checked_add(a, b)                                      \
-do {                                                           \
+({                                                             \
        unsigned _res = (unsigned) (a) + (b);                   \
+       bool overflow = _res > U16_MAX;                         \
+       if (overflow)                                           \
+               _res = U16_MAX;                                 \
        (a) = _res;                                             \
-       BUG_ON((a) != _res);                                    \
-} while (0)
+       overflow;                                               \
+})
 
 static int __bch2_mark_metadata_bucket(struct bch_fs *c, struct bch_dev *ca,
                                       size_t b, enum bch_data_type type,
                                       unsigned sectors, bool gc)
 {
-       struct bch_fs_usage *fs_usage = this_cpu_ptr(c->usage[gc]);
        struct bucket *g = __bucket(ca, b, gc);
-       struct bucket_mark new;
+       struct bucket_mark old, new;
+       bool overflow;
 
        BUG_ON(type != BCH_DATA_SB &&
               type != BCH_DATA_JOURNAL);
 
-       bucket_data_cmpxchg(c, ca, fs_usage, g, new, ({
+       old = bucket_cmpxchg(g, new, ({
                new.dirty       = true;
                new.data_type   = type;
-               checked_add(new.dirty_sectors, sectors);
+               overflow = checked_add(new.dirty_sectors, sectors);
        }));
 
+       bch2_fs_inconsistent_on(overflow, c,
+               "bucket sector count overflow: %u + %u > U16_MAX",
+               old.dirty_sectors, sectors);
+
+       if (c)
+               bch2_dev_usage_update(c, ca, this_cpu_ptr(c->usage[gc]),
+                                     old, new, gc);
+
        return 0;
 }
 
@@ -581,19 +592,7 @@ void bch2_mark_metadata_bucket(struct bch_fs *c, struct bch_dev *ca,
                do_mark_fn(__bch2_mark_metadata_bucket, c, pos, flags,
                           ca, b, type, sectors);
        } else {
-               struct bucket *g;
-               struct bucket_mark new;
-
-               rcu_read_lock();
-
-               g = bucket(ca, b);
-               bucket_cmpxchg(g, new, ({
-                       new.dirty       = true;
-                       new.data_type   = type;
-                       checked_add(new.dirty_sectors, sectors);
-               }));
-
-               rcu_read_unlock();
+               __bch2_mark_metadata_bucket(c, ca, b, type, sectors, 0);
        }
 
        preempt_enable();
@@ -636,6 +635,7 @@ static bool bch2_mark_pointer(struct bch_fs *c,
        struct bch_dev *ca = bch_dev_bkey_exists(c, p.ptr.dev);
        size_t b = PTR_BUCKET_NR(ca, &p.ptr);
        struct bucket *g = __bucket(ca, b, gc);
+       bool overflow;
        u64 v;
 
        v = atomic64_read(&g->_mark.v);
@@ -657,9 +657,9 @@ static bool bch2_mark_pointer(struct bch_fs *c,
                }
 
                if (!p.ptr.cached)
-                       checked_add(new.dirty_sectors, sectors);
+                       overflow = checked_add(new.dirty_sectors, sectors);
                else
-                       checked_add(new.cached_sectors, sectors);
+                       overflow = checked_add(new.cached_sectors, sectors);
 
                if (!new.dirty_sectors &&
                    !new.cached_sectors) {
@@ -681,6 +681,12 @@ static bool bch2_mark_pointer(struct bch_fs *c,
                              old.v.counter,
                              new.v.counter)) != old.v.counter);
 
+       bch2_fs_inconsistent_on(overflow, c,
+               "bucket sector count overflow: %u + %lli > U16_MAX",
+               !p.ptr.cached
+               ? old.dirty_sectors
+               : old.cached_sectors, sectors);
+
        bch2_dev_usage_update(c, ca, fs_usage, old, new, gc);
 
        BUG_ON(!gc && bucket_became_unavailable(old, new));