diff options
Diffstat (limited to 'libbcachefs/fs.c')
| -rw-r--r-- | libbcachefs/fs.c | 139 |
1 files changed, 123 insertions, 16 deletions
diff --git a/libbcachefs/fs.c b/libbcachefs/fs.c index 1aee5baf..857175f4 100644 --- a/libbcachefs/fs.c +++ b/libbcachefs/fs.c @@ -157,6 +157,20 @@ static bool subvol_inum_eq(subvol_inum a, subvol_inum b) return a.subvol == b.subvol && a.inum == b.inum; } +static u32 bch2_vfs_inode_hash_fn(const void *data, u32 len, u32 seed) +{ + const subvol_inum *inum = data; + + return jhash(&inum->inum, sizeof(inum->inum), seed); +} + +static u32 bch2_vfs_inode_obj_hash_fn(const void *data, u32 len, u32 seed) +{ + const struct bch_inode_info *inode = data; + + return bch2_vfs_inode_hash_fn(&inode->ei_inum, sizeof(inode->ei_inum), seed); +} + static int bch2_vfs_inode_cmp_fn(struct rhashtable_compare_arg *arg, const void *obj) { @@ -170,26 +184,111 @@ static const struct rhashtable_params bch2_vfs_inodes_params = { .head_offset = offsetof(struct bch_inode_info, hash), .key_offset = offsetof(struct bch_inode_info, ei_inum), .key_len = sizeof(subvol_inum), + .hashfn = bch2_vfs_inode_hash_fn, + .obj_hashfn = bch2_vfs_inode_obj_hash_fn, .obj_cmpfn = bch2_vfs_inode_cmp_fn, .automatic_shrinking = true, }; -static void __wait_on_freeing_inode(struct inode *inode) +int bch2_inode_or_descendents_is_open(struct btree_trans *trans, struct bpos p) { - wait_queue_head_t *wq; - DEFINE_WAIT_BIT(wait, &inode->i_state, __I_NEW); - wq = bit_waitqueue(&inode->i_state, __I_NEW); - prepare_to_wait(wq, &wait.wq_entry, TASK_UNINTERRUPTIBLE); - spin_unlock(&inode->i_lock); - schedule(); - finish_wait(wq, &wait.wq_entry); + struct bch_fs *c = trans->c; + struct rhashtable *ht = &c->vfs_inodes_table; + subvol_inum inum = (subvol_inum) { .inum = p.offset }; + DARRAY(u32) subvols; + int ret = 0; + + if (!test_bit(BCH_FS_started, &c->flags)) + return false; + + darray_init(&subvols); +restart_from_top: + + /* + * Tweaked version of __rhashtable_lookup(); we need to get a list of + * subvolumes in which the given inode number is open. + * + * For this to work, we don't include the subvolume ID in the key that + * we hash - all inodes with the same inode number regardless of + * subvolume will hash to the same slot. + * + * This will be less than ideal if the same file is ever open + * simultaneously in many different snapshots: + */ + rcu_read_lock(); + struct rhash_lock_head __rcu *const *bkt; + struct rhash_head *he; + unsigned int hash; + struct bucket_table *tbl = rht_dereference_rcu(ht->tbl, ht); +restart: + hash = rht_key_hashfn(ht, tbl, &inum, bch2_vfs_inodes_params); + bkt = rht_bucket(tbl, hash); + do { + struct bch_inode_info *inode; + + rht_for_each_entry_rcu_from(inode, he, rht_ptr_rcu(bkt), tbl, hash, hash) { + if (inode->ei_inum.inum == inum.inum) { + ret = darray_push_gfp(&subvols, inode->ei_inum.subvol, + GFP_NOWAIT|__GFP_NOWARN); + if (ret) { + rcu_read_unlock(); + ret = darray_make_room(&subvols, 1); + if (ret) + goto err; + subvols.nr = 0; + goto restart_from_top; + } + } + } + /* An object might have been moved to a different hash chain, + * while we walk along it - better check and retry. + */ + } while (he != RHT_NULLS_MARKER(bkt)); + + /* Ensure we see any new tables. */ + smp_rmb(); + + tbl = rht_dereference_rcu(tbl->future_tbl, ht); + if (unlikely(tbl)) + goto restart; + rcu_read_unlock(); + + darray_for_each(subvols, i) { + u32 snap; + ret = bch2_subvolume_get_snapshot(trans, *i, &snap); + if (ret) + goto err; + + ret = bch2_snapshot_is_ancestor(c, snap, p.snapshot); + if (ret) + break; + } +err: + darray_exit(&subvols); + return ret; } -struct bch_inode_info *__bch2_inode_hash_find(struct bch_fs *c, subvol_inum inum) +static struct bch_inode_info *__bch2_inode_hash_find(struct bch_fs *c, subvol_inum inum) { return rhashtable_lookup_fast(&c->vfs_inodes_table, &inum, bch2_vfs_inodes_params); } +static void __wait_on_freeing_inode(struct bch_fs *c, + struct bch_inode_info *inode, + subvol_inum inum) +{ + wait_queue_head_t *wq; + struct wait_bit_queue_entry wait; + + wq = inode_bit_waitqueue(&wait, &inode->v, __I_NEW); + prepare_to_wait(wq, &wait.wq_entry, TASK_UNINTERRUPTIBLE); + spin_unlock(&inode->v.i_lock); + + if (__bch2_inode_hash_find(c, inum) == inode) + schedule_timeout(HZ * 10); + finish_wait(wq, &wait.wq_entry); +} + static struct bch_inode_info *bch2_inode_hash_find(struct bch_fs *c, struct btree_trans *trans, subvol_inum inum) { @@ -204,10 +303,10 @@ repeat: } if ((inode->v.i_state & (I_FREEING|I_WILL_FREE))) { if (!trans) { - __wait_on_freeing_inode(&inode->v); + __wait_on_freeing_inode(c, inode, inum); } else { bch2_trans_unlock(trans); - __wait_on_freeing_inode(&inode->v); + __wait_on_freeing_inode(c, inode, inum); int ret = bch2_trans_relock(trans); if (ret) return ERR_PTR(ret); @@ -232,6 +331,11 @@ static void bch2_inode_hash_remove(struct bch_fs *c, struct bch_inode_info *inod &inode->hash, bch2_vfs_inodes_params); BUG_ON(ret); inode->v.i_hash.pprev = NULL; + /* + * This pairs with the bch2_inode_hash_find() -> + * __wait_on_freeing_inode() path + */ + inode_wake_up_bit(&inode->v, __I_NEW); } } @@ -243,7 +347,8 @@ static struct bch_inode_info *bch2_inode_hash_insert(struct bch_fs *c, set_bit(EI_INODE_HASHED, &inode->ei_flags); retry: - if (unlikely(rhashtable_lookup_insert_fast(&c->vfs_inodes_table, + if (unlikely(rhashtable_lookup_insert_key(&c->vfs_inodes_table, + &inode->ei_inum, &inode->hash, bch2_vfs_inodes_params))) { old = bch2_inode_hash_find(c, trans, inode->ei_inum); @@ -1783,14 +1888,16 @@ again: break; } } else if (clean_pass && this_pass_clean) { - wait_queue_head_t *wq = bit_waitqueue(&inode->v.i_state, __I_NEW); - DEFINE_WAIT_BIT(wait, &inode->v.i_state, __I_NEW); + struct wait_bit_queue_entry wqe; + struct wait_queue_head *wq_head; - prepare_to_wait(wq, &wait.wq_entry, TASK_UNINTERRUPTIBLE); + wq_head = inode_bit_waitqueue(&wqe, &inode->v, __I_NEW); + prepare_to_wait_event(wq_head, &wqe.wq_entry, + TASK_UNINTERRUPTIBLE); mutex_unlock(&c->vfs_inodes_lock); schedule(); - finish_wait(wq, &wait.wq_entry); + finish_wait(wq_head, &wqe.wq_entry); goto again; } } |