bcachefs: Fix null ptr deref when splitting compressed extents

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

diff --git a/fs/bcachefs/btree_iter.c b/fs/bcachefs/btree_iter.c
index d9ce82e04e76118bd866e33982081196aa7a0c1e..0dd7938101a5b59efd39e3482e9dfd64ffd9f768 100644 (file)
--- a/fs/bcachefs/btree_iter.c
+++ b/fs/bcachefs/btree_iter.c
@@ -2329,6 +2329,7 @@ void bch2_trans_reset(struct btree_trans *trans, unsigned flags)
 
        trans->iters_touched &= trans->iters_live;
 
+       trans->extra_journal_res        = 0;
        trans->nr_updates               = 0;
        trans->mem_top                  = 0;
 

diff --git a/fs/bcachefs/btree_types.h b/fs/bcachefs/btree_types.h
index e9c209f7a39fedf9458def446c8a6158364460a0..23de816b47575cebdbfc6d8496d63019c5bd9c22 100644 (file)
--- a/fs/bcachefs/btree_types.h
+++ b/fs/bcachefs/btree_types.h
@@ -383,6 +383,11 @@ struct btree_trans {
        unsigned                used_mempool:1;
        unsigned                error:1;
        unsigned                in_traverse_all:1;
+       /*
+        * For when bch2_trans_update notices we'll be splitting a compressed
+        * extent:
+        */
+       unsigned                extra_journal_res;
 
        u64                     iters_linked;
        u64                     iters_live;
@@ -680,7 +685,6 @@ enum btree_insert_ret {
        BTREE_INSERT_OK,
        /* leaf node needs to be split */
        BTREE_INSERT_BTREE_NODE_FULL,
-       BTREE_INSERT_ENOSPC,
        BTREE_INSERT_NEED_MARK_REPLICAS,
        BTREE_INSERT_NEED_JOURNAL_RES,
        BTREE_INSERT_NEED_JOURNAL_RECLAIM,

diff --git a/fs/bcachefs/btree_update_leaf.c b/fs/bcachefs/btree_update_leaf.c
index 4040771d645bacb2b39c23d69742953d38b21257..852d4e39199f5cdfb2dc596de41a3c7847496d69 100644 (file)
--- a/fs/bcachefs/btree_update_leaf.c
+++ b/fs/bcachefs/btree_update_leaf.c
@@ -696,10 +696,6 @@ int bch2_trans_commit_error(struct btree_trans *trans,
                        ret = -EINTR;
                }
                break;
-       case BTREE_INSERT_ENOSPC:
-               BUG_ON(flags & BTREE_INSERT_NOFAIL);
-               ret = -ENOSPC;
-               break;
        case BTREE_INSERT_NEED_MARK_REPLICAS:
                bch2_trans_unlock(trans);
 
@@ -833,7 +829,7 @@ static int extent_handle_overwrites(struct btree_trans *trans,
        struct bpos start = bkey_start_pos(&i->k->k);
        struct bkey_i *update;
        struct bkey_s_c k;
-       int ret = 0;
+       int ret = 0, compressed_sectors;
 
        iter = bch2_trans_get_iter(trans, i->btree_id, start,
                                   BTREE_ITER_INTENT|
@@ -854,6 +850,16 @@ static int extent_handle_overwrites(struct btree_trans *trans,
        }
 
        while (bkey_cmp(i->k->k.p, bkey_start_pos(k.k)) > 0) {
+               /*
+                * If we're going to be splitting a compressed extent, note it
+                * so that __bch2_trans_commit() can increase our disk
+                * reservation:
+                */
+               if (bkey_cmp(bkey_start_pos(k.k), start) < 0 &&
+                   bkey_cmp(k.k->p, i->k->k.p) > 0 &&
+                   (compressed_sectors = bch2_bkey_sectors_compressed(k)))
+                       trans->extra_journal_res += compressed_sectors;
+
                if (bkey_cmp(bkey_start_pos(k.k), start) < 0) {
                        update = bch2_trans_kmalloc(trans, bkey_bytes(k.k));
                        if ((ret = PTR_ERR_OR_ZERO(update)))
@@ -992,6 +998,15 @@ int __bch2_trans_commit(struct btree_trans *trans)
                        trans->journal_preres_u64s += u64s;
                trans->journal_u64s += u64s;
        }
+
+       if (trans->extra_journal_res) {
+               ret = bch2_disk_reservation_add(trans->c, trans->disk_res,
+                               trans->extra_journal_res,
+                               (trans->flags & BTREE_INSERT_NOFAIL)
+                               ? BCH_DISK_RESERVATION_NOFAIL : 0);
+               if (ret)
+                       goto err;
+       }
 retry:
        memset(&trans->journal_res, 0, sizeof(trans->journal_res));
 
@@ -1045,22 +1060,12 @@ int bch2_trans_update(struct btree_trans *trans, struct btree_iter *iter,
        BUG_ON(trans->nr_updates >= BTREE_ITER_MAX);
 
 #ifdef CONFIG_BCACHEFS_DEBUG
-       BUG_ON(bkey_cmp(iter->pos,
-                       is_extent ? bkey_start_pos(&k->k) : k->k.p));
-
-       trans_for_each_update(trans, i) {
-               BUG_ON(bkey_cmp(i->iter->pos, i->k->k.p));
-
+       trans_for_each_update(trans, i)
                BUG_ON(i != trans->updates &&
                       btree_insert_entry_cmp(i - 1, i) >= 0);
-       }
 #endif
 
        if (is_extent) {
-               ret = bch2_extent_can_insert(trans, n.iter, n.k);
-               if (ret)
-                       return ret;
-
                ret = extent_handle_overwrites(trans, &n);
                if (ret)
                        return ret;

diff --git a/fs/bcachefs/extent_update.c b/fs/bcachefs/extent_update.c
index bb4b2b4352e04c727b405f7ea78449cd5095d149..ef4aaf1c30ed50cc909147543c082271bc54f130 100644 (file)
--- a/fs/bcachefs/extent_update.c
+++ b/fs/bcachefs/extent_update.c
@@ -173,38 +173,3 @@ int bch2_extent_is_atomic(struct bkey_i *k, struct btree_iter *iter)
 
        return !bkey_cmp(end, k->k.p);
 }
-
-enum btree_insert_ret
-bch2_extent_can_insert(struct btree_trans *trans,
-                      struct btree_iter *iter,
-                      struct bkey_i *insert)
-{
-       struct bkey_s_c k;
-       int ret, sectors;
-
-       k = bch2_btree_iter_peek_slot(iter);
-       ret = bkey_err(k);
-       if (ret)
-               return ret;
-
-       /* Check if we're splitting a compressed extent: */
-
-       if (bkey_cmp(bkey_start_pos(&insert->k), bkey_start_pos(k.k)) > 0 &&
-           bkey_cmp(insert->k.p, k.k->p) < 0 &&
-           (sectors = bch2_bkey_sectors_compressed(k))) {
-               int flags = trans->flags & BTREE_INSERT_NOFAIL
-                       ? BCH_DISK_RESERVATION_NOFAIL : 0;
-
-               switch (bch2_disk_reservation_add(trans->c, trans->disk_res,
-                                                 sectors, flags)) {
-               case 0:
-                       break;
-               case -ENOSPC:
-                       return BTREE_INSERT_ENOSPC;
-               default:
-                       BUG();
-               }
-       }
-
-       return BTREE_INSERT_OK;
-}

diff --git a/fs/bcachefs/extent_update.h b/fs/bcachefs/extent_update.h
index 38dc084627d253ab6267022f1fb9b3202e6f3d21..2fa4602967e04f5cf02033a19d5d134ba90dcf8c 100644 (file)
--- a/fs/bcachefs/extent_update.h
+++ b/fs/bcachefs/extent_update.h
@@ -9,8 +9,4 @@ int bch2_extent_atomic_end(struct btree_iter *, struct bkey_i *,
 int bch2_extent_trim_atomic(struct bkey_i *, struct btree_iter *);
 int bch2_extent_is_atomic(struct bkey_i *, struct btree_iter *);
 
-enum btree_insert_ret
-bch2_extent_can_insert(struct btree_trans *, struct btree_iter *,
-                      struct bkey_i *);
-
 #endif /* _BCACHEFS_EXTENT_UPDATE_H */