diff options
Diffstat (limited to 'fs/ceph/snap.c')
| -rw-r--r-- | fs/ceph/snap.c | 54 |
1 files changed, 38 insertions, 16 deletions
diff --git a/fs/ceph/snap.c b/fs/ceph/snap.c index ce35fbd4ba5..a97e39f09ba 100644 --- a/fs/ceph/snap.c +++ b/fs/ceph/snap.c @@ -70,13 +70,11 @@ void ceph_get_snap_realm(struct ceph_mds_client *mdsc, * safe. we do need to protect against concurrent empty list * additions, however. */ - if (atomic_read(&realm->nref) == 0) { + if (atomic_inc_return(&realm->nref) == 1) { spin_lock(&mdsc->snap_empty_lock); list_del_init(&realm->empty_item); spin_unlock(&mdsc->snap_empty_lock); } - - atomic_inc(&realm->nref); } static void __insert_snap_realm(struct rb_root *root, @@ -116,7 +114,7 @@ static struct ceph_snap_realm *ceph_create_snap_realm( if (!realm) return ERR_PTR(-ENOMEM); - atomic_set(&realm->nref, 0); /* tree does not take a ref */ + atomic_set(&realm->nref, 1); /* for caller */ realm->ino = ino; INIT_LIST_HEAD(&realm->children); INIT_LIST_HEAD(&realm->child_item); @@ -134,8 +132,8 @@ static struct ceph_snap_realm *ceph_create_snap_realm( * * caller must hold snap_rwsem for write. */ -struct ceph_snap_realm *ceph_lookup_snap_realm(struct ceph_mds_client *mdsc, - u64 ino) +static struct ceph_snap_realm *__lookup_snap_realm(struct ceph_mds_client *mdsc, + u64 ino) { struct rb_node *n = mdsc->snap_realms.rb_node; struct ceph_snap_realm *r; @@ -154,6 +152,16 @@ struct ceph_snap_realm *ceph_lookup_snap_realm(struct ceph_mds_client *mdsc, return NULL; } +struct ceph_snap_realm *ceph_lookup_snap_realm(struct ceph_mds_client *mdsc, + u64 ino) +{ + struct ceph_snap_realm *r; + r = __lookup_snap_realm(mdsc, ino); + if (r) + ceph_get_snap_realm(mdsc, r); + return r; +} + static void __put_snap_realm(struct ceph_mds_client *mdsc, struct ceph_snap_realm *realm); @@ -273,7 +281,6 @@ static int adjust_snap_realm_parent(struct ceph_mds_client *mdsc, } realm->parent_ino = parentino; realm->parent = parent; - ceph_get_snap_realm(mdsc, parent); list_add(&realm->child_item, &parent->children); return 1; } @@ -631,12 +638,14 @@ static void queue_realm_cap_snaps(struct ceph_snap_realm *realm) * Caller must hold snap_rwsem for write. */ int ceph_update_snap_trace(struct ceph_mds_client *mdsc, - void *p, void *e, bool deletion) + void *p, void *e, bool deletion, + struct ceph_snap_realm **realm_ret) { struct ceph_mds_snap_realm *ri; /* encoded */ __le64 *snaps; /* encoded */ __le64 *prior_parent_snaps; /* encoded */ - struct ceph_snap_realm *realm; + struct ceph_snap_realm *realm = NULL; + struct ceph_snap_realm *first_realm = NULL; int invalidate = 0; int err = -ENOMEM; LIST_HEAD(dirty_realms); @@ -704,13 +713,18 @@ more: dout("done with %llx %p, invalidated=%d, %p %p\n", realm->ino, realm, invalidate, p, e); - if (p < e) - goto more; - /* invalidate when we reach the _end_ (root) of the trace */ - if (invalidate) + if (invalidate && p >= e) rebuild_snap_realms(realm); + if (!first_realm) + first_realm = realm; + else + ceph_put_snap_realm(mdsc, realm); + + if (p < e) + goto more; + /* * queue cap snaps _after_ we've built the new snap contexts, * so that i_head_snapc can be set appropriately. @@ -721,12 +735,21 @@ more: queue_realm_cap_snaps(realm); } + if (realm_ret) + *realm_ret = first_realm; + else + ceph_put_snap_realm(mdsc, first_realm); + __cleanup_empty_realms(mdsc); return 0; bad: err = -EINVAL; fail: + if (realm && !IS_ERR(realm)) + ceph_put_snap_realm(mdsc, realm); + if (first_realm) + ceph_put_snap_realm(mdsc, first_realm); pr_err("update_snap_trace error %d\n", err); return err; } @@ -844,7 +867,6 @@ void ceph_handle_snap(struct ceph_mds_client *mdsc, if (IS_ERR(realm)) goto out; } - ceph_get_snap_realm(mdsc, realm); dout("splitting snap_realm %llx %p\n", realm->ino, realm); for (i = 0; i < num_split_inos; i++) { @@ -905,7 +927,7 @@ skip_inode: /* we may have taken some of the old realm's children. */ for (i = 0; i < num_split_realms; i++) { struct ceph_snap_realm *child = - ceph_lookup_snap_realm(mdsc, + __lookup_snap_realm(mdsc, le64_to_cpu(split_realms[i])); if (!child) continue; @@ -918,7 +940,7 @@ skip_inode: * snap, we can avoid queueing cap_snaps. */ ceph_update_snap_trace(mdsc, p, e, - op == CEPH_SNAP_OP_DESTROY); + op == CEPH_SNAP_OP_DESTROY, NULL); if (op == CEPH_SNAP_OP_SPLIT) /* we took a reference when we created the realm, above */ |