]> git.sesse.net Git - bcachefs-tools-debian/blobdiff - libbcachefs/subvolume.c
Merge https://github.com/YellowOnion/bcachefs-tools
[bcachefs-tools-debian] / libbcachefs / subvolume.c
index d1c111050c35cdf2601e011f504b46175ef58c2d..0ef625d21672798595db8d172d82c75768aa1e68 100644 (file)
@@ -4,6 +4,7 @@
 #include "btree_key_cache.h"
 #include "btree_update.h"
 #include "error.h"
+#include "fs.h"
 #include "subvolume.h"
 
 /* Snapshot tree: */
@@ -60,10 +61,11 @@ const char *bch2_snapshot_invalid(const struct bch_fs *c, struct bkey_s_c k)
        return NULL;
 }
 
-int bch2_mark_snapshot(struct bch_fs *c,
+int bch2_mark_snapshot(struct btree_trans *trans,
                       struct bkey_s_c old, struct bkey_s_c new,
-                      u64 journal_seq, unsigned flags)
+                      unsigned flags)
 {
+       struct bch_fs *c = trans->c;
        struct snapshot_t *t;
 
        t = genradix_ptr_alloc(&c->snapshots,
@@ -307,7 +309,7 @@ int bch2_fs_snapshots_start(struct bch_fs *c)
                if (BCH_SNAPSHOT_DELETED(bkey_s_c_to_snapshot(k).v))
                        have_deleted = true;
 
-               ret = bch2_mark_snapshot(c, bkey_s_c_null, k, 0, 0);
+               ret = bch2_mark_snapshot(&trans, bkey_s_c_null, k, 0);
                if (ret)
                        break;
        }
@@ -498,7 +500,7 @@ static int bch2_snapshot_node_create(struct btree_trans *trans, u32 parent,
 
                bch2_trans_update(trans, &iter, &n->k_i, 0);
 
-               ret = bch2_mark_snapshot(trans->c, bkey_s_c_null, bkey_i_to_s_c(&n->k_i), 0, 0);
+               ret = bch2_mark_snapshot(trans, bkey_s_c_null, bkey_i_to_s_c(&n->k_i), 0);
                if (ret)
                        break;
 
@@ -541,23 +543,6 @@ err:
        return ret;
 }
 
-/* List of snapshot IDs that are being deleted: */
-struct snapshot_id_list {
-       u32             nr;
-       u32             size;
-       u32             *d;
-};
-
-static bool snapshot_list_has_id(struct snapshot_id_list *s, u32 id)
-{
-       unsigned i;
-
-       for (i = 0; i < s->nr; i++)
-               if (id == s->d[i])
-                       return true;
-       return false;
-}
-
 static int snapshot_id_add(struct snapshot_id_list *s, u32 id)
 {
        BUG_ON(snapshot_list_has_id(s, id));
@@ -819,9 +804,11 @@ int bch2_subvolume_get_snapshot(struct btree_trans *trans, u32 subvol,
        return ret;
 }
 
-/* XXX: mark snapshot id for deletion, walk btree and delete: */
-int bch2_subvolume_delete(struct btree_trans *trans, u32 subvolid,
-                         int deleting_snapshot)
+/*
+ * Delete subvolume, mark snapshot ID as deleted, queue up snapshot
+ * deletion/cleanup:
+ */
+int bch2_subvolume_delete(struct btree_trans *trans, u32 subvolid)
 {
        struct btree_iter iter;
        struct bkey_s_c k;
@@ -849,12 +836,6 @@ int bch2_subvolume_delete(struct btree_trans *trans, u32 subvolid,
        subvol = bkey_s_c_to_subvolume(k);
        snapid = le32_to_cpu(subvol.v->snapshot);
 
-       if (deleting_snapshot >= 0 &&
-           deleting_snapshot != BCH_SUBVOLUME_SNAP(subvol.v)) {
-               ret = -ENOENT;
-               goto err;
-       }
-
        delete = bch2_trans_kmalloc(trans, sizeof(*delete));
        ret = PTR_ERR_OR_ZERO(delete);
        if (ret)
@@ -880,12 +861,123 @@ err:
        return ret;
 }
 
+void bch2_subvolume_wait_for_pagecache_and_delete(struct work_struct *work)
+{
+       struct bch_fs *c = container_of(work, struct bch_fs,
+                               snapshot_wait_for_pagecache_and_delete_work);
+       struct snapshot_id_list s;
+       u32 *id;
+       int ret = 0;
+
+       while (!ret) {
+               mutex_lock(&c->snapshots_unlinked_lock);
+               s = c->snapshots_unlinked;
+               memset(&c->snapshots_unlinked, 0, sizeof(c->snapshots_unlinked));
+               mutex_unlock(&c->snapshots_unlinked_lock);
+
+               if (!s.nr)
+                       break;
+
+               bch2_evict_subvolume_inodes(c, &s);
+
+               for (id = s.d; id < s.d + s.nr; id++) {
+                       ret = bch2_trans_do(c, NULL, NULL, BTREE_INSERT_NOFAIL,
+                                     bch2_subvolume_delete(&trans, *id));
+                       if (ret) {
+                               bch_err(c, "error %i deleting subvolume %u", ret, *id);
+                               break;
+                       }
+               }
+
+               kfree(s.d);
+       }
+
+       percpu_ref_put(&c->writes);
+}
+
+struct subvolume_unlink_hook {
+       struct btree_trans_commit_hook  h;
+       u32                             subvol;
+};
+
+int bch2_subvolume_wait_for_pagecache_and_delete_hook(struct btree_trans *trans,
+                                                     struct btree_trans_commit_hook *_h)
+{
+       struct subvolume_unlink_hook *h = container_of(_h, struct subvolume_unlink_hook, h);
+       struct bch_fs *c = trans->c;
+       int ret = 0;
+
+       mutex_lock(&c->snapshots_unlinked_lock);
+       if (!snapshot_list_has_id(&c->snapshots_unlinked, h->subvol))
+               ret = snapshot_id_add(&c->snapshots_unlinked, h->subvol);
+       mutex_unlock(&c->snapshots_unlinked_lock);
+
+       if (ret)
+               return ret;
+
+       if (unlikely(!percpu_ref_tryget(&c->writes)))
+               return -EROFS;
+
+       if (!queue_work(system_long_wq, &c->snapshot_wait_for_pagecache_and_delete_work))
+               percpu_ref_put(&c->writes);
+       return 0;
+}
+
+int bch2_subvolume_unlink(struct btree_trans *trans, u32 subvolid)
+{
+       struct btree_iter iter;
+       struct bkey_s_c k;
+       struct bkey_i_subvolume *n;
+       struct subvolume_unlink_hook *h;
+       int ret = 0;
+
+       bch2_trans_iter_init(trans, &iter, BTREE_ID_subvolumes,
+                            POS(0, subvolid),
+                            BTREE_ITER_CACHED|
+                            BTREE_ITER_INTENT);
+       k = bch2_btree_iter_peek_slot(&iter);
+       ret = bkey_err(k);
+       if (ret)
+               goto err;
+
+       if (k.k->type != KEY_TYPE_subvolume) {
+               bch2_fs_inconsistent(trans->c, "missing subvolume %u", subvolid);
+               ret = -EIO;
+               goto err;
+       }
+
+       n = bch2_trans_kmalloc(trans, sizeof(*n));
+       ret = PTR_ERR_OR_ZERO(n);
+       if (ret)
+               goto err;
+
+       bkey_reassemble(&n->k_i, k);
+       SET_BCH_SUBVOLUME_UNLINKED(&n->v, true);
+
+       ret = bch2_trans_update(trans, &iter, &n->k_i, 0);
+       if (ret)
+               goto err;
+
+       h = bch2_trans_kmalloc(trans, sizeof(*h));
+       ret = PTR_ERR_OR_ZERO(h);
+       if (ret)
+               goto err;
+
+       h->h.fn         = bch2_subvolume_wait_for_pagecache_and_delete_hook;
+       h->subvol       = subvolid;
+       bch2_trans_commit_hook(trans, &h->h);
+err:
+       bch2_trans_iter_exit(trans, &iter);
+       return ret;
+}
+
 int bch2_subvolume_create(struct btree_trans *trans, u64 inode,
                          u32 src_subvolid,
                          u32 *new_subvolid,
                          u32 *new_snapshotid,
                          bool ro)
 {
+       struct bch_fs *c = trans->c;
        struct btree_iter dst_iter, src_iter = (struct btree_iter) { NULL };
        struct bkey_i_subvolume *new_subvol = NULL;
        struct bkey_i_subvolume *src_subvol = NULL;
@@ -897,7 +989,13 @@ int bch2_subvolume_create(struct btree_trans *trans, u64 inode,
                           BTREE_ITER_SLOTS|BTREE_ITER_INTENT, k, ret) {
                if (bkey_cmp(k.k->p, SUBVOL_POS_MAX) > 0)
                        break;
-               if (bkey_deleted(k.k))
+
+               /*
+                * bch2_subvolume_delete() doesn't flush the btree key cache -
+                * ideally it would but that's tricky
+                */
+               if (bkey_deleted(k.k) &&
+                   !bch2_btree_key_cache_find(c, BTREE_ID_subvolumes, dst_iter.pos))
                        goto found_slot;
        }
 
@@ -925,7 +1023,7 @@ found_slot:
                        goto err;
 
                if (k.k->type != KEY_TYPE_subvolume) {
-                       bch_err(trans->c, "subvolume %u not found", src_subvolid);
+                       bch_err(c, "subvolume %u not found", src_subvolid);
                        ret = -ENOENT;
                        goto err;
                }
@@ -970,5 +1068,8 @@ err:
 int bch2_fs_subvolumes_init(struct bch_fs *c)
 {
        INIT_WORK(&c->snapshot_delete_work, bch2_delete_dead_snapshots_work);
+       INIT_WORK(&c->snapshot_wait_for_pagecache_and_delete_work,
+                 bch2_subvolume_wait_for_pagecache_and_delete);
+       mutex_init(&c->snapshots_unlinked_lock);
        return 0;
 }