]> git.sesse.net Git - bcachefs-tools-debian/blobdiff - libbcachefs/subvolume.c
Update bcachefs sources to 04f2d2ae5b bcachefs: Fix build error on weird gcc
[bcachefs-tools-debian] / libbcachefs / subvolume.c
index f3852c433ca981c3e80f75d9240db6d861dae4b1..f118e585f12080d3d0389ffd6a30d9df27185183 100644 (file)
@@ -8,8 +8,41 @@
 #include "fs.h"
 #include "subvolume.h"
 
+#include <linux/random.h>
+
 static int bch2_subvolume_delete(struct btree_trans *, u32);
 
+static inline u32 get_ancestor_below(struct bch_fs *c, u32 id, u32 ancestor)
+{
+       struct snapshot_t *s = snapshot_t(c, id);
+
+       if (s->skip[2] <= ancestor)
+               return s->skip[2];
+       if (s->skip[1] <= ancestor)
+               return s->skip[1];
+       if (s->skip[0] <= ancestor)
+               return s->skip[0];
+       return s->parent;
+}
+
+bool bch2_snapshot_is_ancestor(struct bch_fs *c, u32 id, u32 ancestor)
+{
+       EBUG_ON(c->curr_recovery_pass <= BCH_RECOVERY_PASS_check_snapshots);
+
+       while (id && id < ancestor)
+               id = get_ancestor_below(c, id, ancestor);
+
+       return id == ancestor;
+}
+
+static bool bch2_snapshot_is_ancestor_early(struct bch_fs *c, u32 id, u32 ancestor)
+{
+       while (id && id < ancestor)
+               id = snapshot_t(c, id)->parent;
+
+       return id == ancestor;
+}
+
 /* Snapshot tree: */
 
 void bch2_snapshot_tree_to_text(struct printbuf *out, struct bch_fs *c,
@@ -140,6 +173,25 @@ int bch2_snapshot_invalid(const struct bch_fs *c, struct bkey_s_c k,
                }
        }
 
+       if (bkey_val_bytes(k.k) > offsetof(struct bch_snapshot, skip)) {
+               if (le32_to_cpu(s.v->skip[0]) > le32_to_cpu(s.v->skip[1]) ||
+                   le32_to_cpu(s.v->skip[1]) > le32_to_cpu(s.v->skip[2])) {
+                       prt_printf(err, "skiplist not normalized");
+                       return -BCH_ERR_invalid_bkey;
+               }
+
+               for (i = 0; i < ARRAY_SIZE(s.v->skip); i++) {
+                       id = le32_to_cpu(s.v->skip[i]);
+
+                       if (!id != !s.v->parent ||
+                           (s.v->parent &&
+                            id <= k.k->p.offset)) {
+                               prt_printf(err, "bad skiplist node %u)", id);
+                               return -BCH_ERR_invalid_bkey;
+                       }
+               }
+       }
+
        return 0;
 }
 
@@ -161,10 +213,17 @@ int bch2_mark_snapshot(struct btree_trans *trans,
                struct bkey_s_c_snapshot s = bkey_s_c_to_snapshot(new);
 
                t->parent       = le32_to_cpu(s.v->parent);
+               t->skip[0]      = le32_to_cpu(s.v->skip[0]);
+               t->skip[1]      = le32_to_cpu(s.v->skip[1]);
+               t->skip[2]      = le32_to_cpu(s.v->skip[2]);
+               t->depth        = le32_to_cpu(s.v->depth);
                t->children[0]  = le32_to_cpu(s.v->children[0]);
                t->children[1]  = le32_to_cpu(s.v->children[1]);
                t->subvol       = BCH_SNAPSHOT_SUBVOL(s.v) ? le32_to_cpu(s.v->subvol) : 0;
                t->tree         = le32_to_cpu(s.v->tree);
+
+               if (BCH_SNAPSHOT_DELETED(s.v))
+                       set_bit(BCH_FS_HAVE_DELETED_SNAPSHOTS, &c->flags);
        } else {
                t->parent       = 0;
                t->children[0]  = 0;
@@ -370,9 +429,9 @@ static int check_snapshot_tree(struct btree_trans *trans,
                        "snapshot tree points to missing subvolume:\n  %s",
                        (printbuf_reset(&buf),
                         bch2_bkey_val_to_text(&buf, c, st.s_c), buf.buf)) ||
-           fsck_err_on(!bch2_snapshot_is_ancestor(c,
-                                                  le32_to_cpu(subvol.snapshot),
-                                                  root_id), c,
+           fsck_err_on(!bch2_snapshot_is_ancestor_early(c,
+                                               le32_to_cpu(subvol.snapshot),
+                                               root_id), c,
                        "snapshot tree points to subvolume that does not point to snapshot in this tree:\n  %s",
                        (printbuf_reset(&buf),
                         bch2_bkey_val_to_text(&buf, c, st.s_c), buf.buf)) ||
@@ -441,7 +500,48 @@ static int snapshot_tree_ptr_good(struct btree_trans *trans,
        if (ret)
                return ret;
 
-       return bch2_snapshot_is_ancestor(trans->c, snap_id, le32_to_cpu(s_t.root_snapshot));
+       return bch2_snapshot_is_ancestor_early(trans->c, snap_id, le32_to_cpu(s_t.root_snapshot));
+}
+
+static u32 snapshot_rand_ancestor_get(struct bch_fs *c, u32 id)
+{
+       struct snapshot_t *s;
+
+       if (!id)
+               return 0;
+
+       s = snapshot_t(c, id);
+       if (!s->parent)
+               return id;
+
+       return bch2_snapshot_nth_parent(c, id, get_random_u32_below(s->depth));
+}
+
+static int snapshot_rand_ancestor_good(struct btree_trans *trans,
+                                      struct bch_snapshot s)
+{
+       struct bch_snapshot a;
+       unsigned i;
+       int ret;
+
+       for (i = 0; i < 3; i++) {
+               if (!s.parent != !s.skip[i])
+                       return false;
+
+               if (!s.parent)
+                       continue;
+
+               ret = snapshot_lookup(trans, le32_to_cpu(s.skip[i]), &a);
+               if (bch2_err_matches(ret, ENOENT))
+                       return false;
+               if (ret)
+                       return ret;
+
+               if (a.tree != s.tree)
+                       return false;
+       }
+
+       return true;
 }
 
 /*
@@ -451,14 +551,15 @@ static int snapshot_tree_ptr_good(struct btree_trans *trans,
  */
 static int snapshot_tree_ptr_repair(struct btree_trans *trans,
                                    struct btree_iter *iter,
-                                   struct bkey_s_c_snapshot *s)
+                                   struct bkey_s_c k,
+                                   struct bch_snapshot *s)
 {
        struct bch_fs *c = trans->c;
        struct btree_iter root_iter;
        struct bch_snapshot_tree s_t;
        struct bkey_s_c_snapshot root;
        struct bkey_i_snapshot *u;
-       u32 root_id = bch2_snapshot_root(c, s->k->p.offset), tree_id;
+       u32 root_id = bch2_snapshot_root(c, k.k->p.offset), tree_id;
        int ret;
 
        root = bch2_bkey_get_iter_typed(trans, &root_iter,
@@ -484,18 +585,18 @@ static int snapshot_tree_ptr_repair(struct btree_trans *trans,
                        goto err;
 
                u->v.tree = cpu_to_le32(tree_id);
-               if (s->k->p.snapshot == root_id)
-                       *s = snapshot_i_to_s_c(u);
+               if (k.k->p.offset == root_id)
+                       *s = u->v;
        }
 
-       if (s->k->p.snapshot != root_id) {
-               u = bch2_bkey_make_mut_typed(trans, iter, &s->s_c, 0, snapshot);
+       if (k.k->p.offset != root_id) {
+               u = bch2_bkey_make_mut_typed(trans, iter, &k, 0, snapshot);
                ret = PTR_ERR_OR_ZERO(u);
                if (ret)
                        goto err;
 
                u->v.tree = cpu_to_le32(tree_id);
-               *s = snapshot_i_to_s_c(u);
+               *s = u->v;
        }
 err:
        bch2_trans_iter_exit(trans, &root_iter);
@@ -507,9 +608,14 @@ static int check_snapshot(struct btree_trans *trans,
                          struct bkey_s_c k)
 {
        struct bch_fs *c = trans->c;
-       struct bkey_s_c_snapshot s;
+       struct bch_snapshot s;
        struct bch_subvolume subvol;
        struct bch_snapshot v;
+       struct bkey_i_snapshot *u;
+       u32 parent_id = bch2_snapshot_parent_early(c, k.k->p.offset);
+       struct snapshot_t *parent = parent_id
+               ? snapshot_t(c, parent_id)
+               : NULL;
        struct printbuf buf = PRINTBUF;
        bool should_have_subvol;
        u32 i, id;
@@ -518,94 +624,119 @@ static int check_snapshot(struct btree_trans *trans,
        if (k.k->type != KEY_TYPE_snapshot)
                return 0;
 
-       s = bkey_s_c_to_snapshot(k);
-       id = le32_to_cpu(s.v->parent);
+       memset(&s, 0, sizeof(s));
+       memcpy(&s, k.v, bkey_val_bytes(k.k));
+
+       id = le32_to_cpu(s.parent);
        if (id) {
                ret = snapshot_lookup(trans, id, &v);
                if (bch2_err_matches(ret, ENOENT))
                        bch_err(c, "snapshot with nonexistent parent:\n  %s",
-                               (bch2_bkey_val_to_text(&buf, c, s.s_c), buf.buf));
+                               (bch2_bkey_val_to_text(&buf, c, k), buf.buf));
                if (ret)
                        goto err;
 
-               if (le32_to_cpu(v.children[0]) != s.k->p.offset &&
-                   le32_to_cpu(v.children[1]) != s.k->p.offset) {
+               if (le32_to_cpu(v.children[0]) != k.k->p.offset &&
+                   le32_to_cpu(v.children[1]) != k.k->p.offset) {
                        bch_err(c, "snapshot parent %u missing pointer to child %llu",
-                               id, s.k->p.offset);
+                               id, k.k->p.offset);
                        ret = -EINVAL;
                        goto err;
                }
        }
 
-       for (i = 0; i < 2 && s.v->children[i]; i++) {
-               id = le32_to_cpu(s.v->children[i]);
+       for (i = 0; i < 2 && s.children[i]; i++) {
+               id = le32_to_cpu(s.children[i]);
 
                ret = snapshot_lookup(trans, id, &v);
                if (bch2_err_matches(ret, ENOENT))
                        bch_err(c, "snapshot node %llu has nonexistent child %u",
-                               s.k->p.offset, id);
+                               k.k->p.offset, id);
                if (ret)
                        goto err;
 
-               if (le32_to_cpu(v.parent) != s.k->p.offset) {
+               if (le32_to_cpu(v.parent) != k.k->p.offset) {
                        bch_err(c, "snapshot child %u has wrong parent (got %u should be %llu)",
-                               id, le32_to_cpu(v.parent), s.k->p.offset);
+                               id, le32_to_cpu(v.parent), k.k->p.offset);
                        ret = -EINVAL;
                        goto err;
                }
        }
 
-       should_have_subvol = BCH_SNAPSHOT_SUBVOL(s.v) &&
-               !BCH_SNAPSHOT_DELETED(s.v);
+       should_have_subvol = BCH_SNAPSHOT_SUBVOL(&s) &&
+               !BCH_SNAPSHOT_DELETED(&s);
 
        if (should_have_subvol) {
-               id = le32_to_cpu(s.v->subvol);
+               id = le32_to_cpu(s.subvol);
                ret = bch2_subvolume_get(trans, id, 0, false, &subvol);
                if (bch2_err_matches(ret, ENOENT))
                        bch_err(c, "snapshot points to nonexistent subvolume:\n  %s",
-                               (bch2_bkey_val_to_text(&buf, c, s.s_c), buf.buf));
+                               (bch2_bkey_val_to_text(&buf, c, k), buf.buf));
                if (ret)
                        goto err;
 
-               if (BCH_SNAPSHOT_SUBVOL(s.v) != (le32_to_cpu(subvol.snapshot) == s.k->p.offset)) {
+               if (BCH_SNAPSHOT_SUBVOL(&s) != (le32_to_cpu(subvol.snapshot) == k.k->p.offset)) {
                        bch_err(c, "snapshot node %llu has wrong BCH_SNAPSHOT_SUBVOL",
-                               s.k->p.offset);
+                               k.k->p.offset);
                        ret = -EINVAL;
                        goto err;
                }
        } else {
-               if (fsck_err_on(s.v->subvol, c, "snapshot should not point to subvol:\n  %s",
-                               (bch2_bkey_val_to_text(&buf, c, s.s_c), buf.buf))) {
-                       struct bkey_i_snapshot *u = bch2_trans_kmalloc(trans, sizeof(*u));
-
+               if (fsck_err_on(s.subvol, c, "snapshot should not point to subvol:\n  %s",
+                               (bch2_bkey_val_to_text(&buf, c, k), buf.buf))) {
+                       u = bch2_bkey_make_mut_typed(trans, iter, &k, 0, snapshot);
                        ret = PTR_ERR_OR_ZERO(u);
                        if (ret)
                                goto err;
 
-                       bkey_reassemble(&u->k_i, s.s_c);
                        u->v.subvol = 0;
-                       ret = bch2_trans_update(trans, iter, &u->k_i, 0);
-                       if (ret)
-                               goto err;
-
-                       s = snapshot_i_to_s_c(u);
+                       s = u->v;
                }
        }
 
-       ret = snapshot_tree_ptr_good(trans, s.k->p.offset, le32_to_cpu(s.v->tree));
+       ret = snapshot_tree_ptr_good(trans, k.k->p.offset, le32_to_cpu(s.tree));
        if (ret < 0)
                goto err;
 
        if (fsck_err_on(!ret, c, "snapshot points to missing/incorrect tree:\n  %s",
-                       (bch2_bkey_val_to_text(&buf, c, s.s_c), buf.buf))) {
-               ret = snapshot_tree_ptr_repair(trans, iter, &s);
+                       (bch2_bkey_val_to_text(&buf, c, k), buf.buf))) {
+               ret = snapshot_tree_ptr_repair(trans, iter, k, &s);
                if (ret)
                        goto err;
        }
        ret = 0;
 
-       if (BCH_SNAPSHOT_DELETED(s.v))
-               set_bit(BCH_FS_HAVE_DELETED_SNAPSHOTS, &c->flags);
+       if (fsck_err_on(le32_to_cpu(s.depth) != (parent ? parent->depth + 1 : 0), c,
+                       "snapshot with incorrect depth fields, should be %u:\n  %s",
+                       parent->depth + 1,
+                       (bch2_bkey_val_to_text(&buf, c, k), buf.buf))) {
+               u = bch2_bkey_make_mut_typed(trans, iter, &k, 0, snapshot);
+               ret = PTR_ERR_OR_ZERO(u);
+               if (ret)
+                       goto err;
+
+               u->v.depth = cpu_to_le32(parent ? parent->depth + 1 : 0);
+               s = u->v;
+       }
+
+       ret = snapshot_rand_ancestor_good(trans, s);
+       if (ret < 0)
+               goto err;
+
+       if (fsck_err_on(!ret, c, "snapshot with bad rand_ancestor field:\n  %s",
+                       (bch2_bkey_val_to_text(&buf, c, k), buf.buf))) {
+               u = bch2_bkey_make_mut_typed(trans, iter, &k, 0, snapshot);
+               ret = PTR_ERR_OR_ZERO(u);
+               if (ret)
+                       goto err;
+
+               for (i = 0; i < ARRAY_SIZE(u->v.skip); i++)
+                       u->v.skip[i] = cpu_to_le32(snapshot_rand_ancestor_get(c, parent_id));
+
+               bubble_sort(u->v.skip, ARRAY_SIZE(u->v.skip), cmp_int);
+               s = u->v;
+       }
+       ret = 0;
 err:
 fsck_err:
        printbuf_exit(&buf);
@@ -618,9 +749,13 @@ int bch2_check_snapshots(struct bch_fs *c)
        struct bkey_s_c k;
        int ret;
 
+       /*
+        * We iterate backwards as checking/fixing the depth field requires that
+        * the parent's depth already be correct:
+        */
        ret = bch2_trans_run(c,
-               for_each_btree_key_commit(&trans, iter,
-                       BTREE_ID_snapshots, POS_MIN,
+               for_each_btree_key_reverse_commit(&trans, iter,
+                       BTREE_ID_snapshots, POS_MAX,
                        BTREE_ITER_PREFETCH, k,
                        NULL, NULL, BTREE_INSERT_LAZY_RW|BTREE_INSERT_NOFAIL,
                check_snapshot(&trans, &iter, k)));
@@ -847,10 +982,12 @@ static int create_snapids(struct btree_trans *trans, u32 parent, u32 tree,
                          u32 *snapshot_subvols,
                          unsigned nr_snapids)
 {
+       struct bch_fs *c = trans->c;
        struct btree_iter iter;
        struct bkey_i_snapshot *n;
        struct bkey_s_c k;
-       unsigned i;
+       unsigned i, j;
+       u32 depth = parent ? snapshot_t(c, parent)->depth + 1 : 0;
        int ret;
 
        bch2_trans_iter_init(trans, &iter, BTREE_ID_snapshots,
@@ -880,6 +1017,12 @@ static int create_snapids(struct btree_trans *trans, u32 parent, u32 tree,
                n->v.parent     = cpu_to_le32(parent);
                n->v.subvol     = cpu_to_le32(snapshot_subvols[i]);
                n->v.tree       = cpu_to_le32(tree);
+               n->v.depth      = cpu_to_le32(depth);
+
+               for (j = 0; j < ARRAY_SIZE(n->v.skip); j++)
+                       n->v.skip[j] = cpu_to_le32(snapshot_rand_ancestor_get(c, parent));
+
+               bubble_sort(n->v.skip, ARRAY_SIZE(n->v.skip), cmp_int);
                SET_BCH_SNAPSHOT_SUBVOL(&n->v, true);
 
                ret = bch2_mark_snapshot(trans, BTREE_ID_snapshots, 0,