diff options
Diffstat (limited to 'fs/dlm/lock.c')
| -rw-r--r-- | fs/dlm/lock.c | 1022 |
1 files changed, 819 insertions, 203 deletions
diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c index bdafb65a5234..d9ee1b96549a 100644 --- a/fs/dlm/lock.c +++ b/fs/dlm/lock.c @@ -90,6 +90,7 @@ static void __receive_convert_reply(struct dlm_rsb *r, struct dlm_lkb *lkb, static int receive_extralen(struct dlm_message *ms); static void do_purge(struct dlm_ls *ls, int nodeid, int pid); static void del_timeout(struct dlm_lkb *lkb); +static void toss_rsb(struct kref *kref); /* * Lock compatibilty matrix - thanks Steve @@ -170,9 +171,11 @@ void dlm_print_lkb(struct dlm_lkb *lkb) static void dlm_print_rsb(struct dlm_rsb *r) { - printk(KERN_ERR "rsb: nodeid %d flags %lx first %x rlc %d name %s\n", - r->res_nodeid, r->res_flags, r->res_first_lkid, - r->res_recover_locks_count, r->res_name); + printk(KERN_ERR "rsb: nodeid %d master %d dir %d flags %lx first %x " + "rlc %d name %s\n", + r->res_nodeid, r->res_master_nodeid, r->res_dir_nodeid, + r->res_flags, r->res_first_lkid, r->res_recover_locks_count, + r->res_name); } void dlm_dump_rsb(struct dlm_rsb *r) @@ -327,6 +330,37 @@ static void queue_bast(struct dlm_rsb *r, struct dlm_lkb *lkb, int rqmode) * Basic operations on rsb's and lkb's */ +/* This is only called to add a reference when the code already holds + a valid reference to the rsb, so there's no need for locking. */ + +static inline void hold_rsb(struct dlm_rsb *r) +{ + kref_get(&r->res_ref); +} + +void dlm_hold_rsb(struct dlm_rsb *r) +{ + hold_rsb(r); +} + +/* When all references to the rsb are gone it's transferred to + the tossed list for later disposal. */ + +static void put_rsb(struct dlm_rsb *r) +{ + struct dlm_ls *ls = r->res_ls; + uint32_t bucket = r->res_bucket; + + spin_lock(&ls->ls_rsbtbl[bucket].lock); + kref_put(&r->res_ref, toss_rsb); + spin_unlock(&ls->ls_rsbtbl[bucket].lock); +} + +void dlm_put_rsb(struct dlm_rsb *r) +{ + put_rsb(r); +} + static int pre_rsb_struct(struct dlm_ls *ls) { struct dlm_rsb *r1, *r2; @@ -411,11 +445,10 @@ static int rsb_cmp(struct dlm_rsb *r, const char *name, int nlen) } int dlm_search_rsb_tree(struct rb_root *tree, char *name, int len, - unsigned int flags, struct dlm_rsb **r_ret) + struct dlm_rsb **r_ret) { struct rb_node *node = tree->rb_node; struct dlm_rsb *r; - int error = 0; int rc; while (node) { @@ -432,10 +465,8 @@ int dlm_search_rsb_tree(struct rb_root *tree, char *name, int len, return -EBADR; found: - if (r->res_nodeid && (flags & R_MASTER)) - error = -ENOTBLK; *r_ret = r; - return error; + return 0; } static int rsb_insert(struct dlm_rsb *rsb, struct rb_root *tree) @@ -467,124 +498,587 @@ static int rsb_insert(struct dlm_rsb *rsb, struct rb_root *tree) return 0; } -static int _search_rsb(struct dlm_ls *ls, char *name, int len, int b, - unsigned int flags, struct dlm_rsb **r_ret) +/* + * Find rsb in rsbtbl and potentially create/add one + * + * Delaying the release of rsb's has a similar benefit to applications keeping + * NL locks on an rsb, but without the guarantee that the cached master value + * will still be valid when the rsb is reused. Apps aren't always smart enough + * to keep NL locks on an rsb that they may lock again shortly; this can lead + * to excessive master lookups and removals if we don't delay the release. + * + * Searching for an rsb means looking through both the normal list and toss + * list. When found on the toss list the rsb is moved to the normal list with + * ref count of 1; when found on normal list the ref count is incremented. + * + * rsb's on the keep list are being used locally and refcounted. + * rsb's on the toss list are not being used locally, and are not refcounted. + * + * The toss list rsb's were either + * - previously used locally but not any more (were on keep list, then + * moved to toss list when last refcount dropped) + * - created and put on toss list as a directory record for a lookup + * (we are the dir node for the res, but are not using the res right now, + * but some other node is) + * + * The purpose of find_rsb() is to return a refcounted rsb for local use. + * So, if the given rsb is on the toss list, it is moved to the keep list + * before being returned. + * + * toss_rsb() happens when all local usage of the rsb is done, i.e. no + * more refcounts exist, so the rsb is moved from the keep list to the + * toss list. + * + * rsb's on both keep and toss lists are used for doing a name to master + * lookups. rsb's that are in use locally (and being refcounted) are on + * the keep list, rsb's that are not in use locally (not refcounted) and + * only exist for name/master lookups are on the toss list. + * + * rsb's on the toss list who's dir_nodeid is not local can have stale + * name/master mappings. So, remote requests on such rsb's can potentially + * return with an error, which means the mapping is stale and needs to + * be updated with a new lookup. (The idea behind MASTER UNCERTAIN and + * first_lkid is to keep only a single outstanding request on an rsb + * while that rsb has a potentially stale master.) + */ + +static int find_rsb_dir(struct dlm_ls *ls, char *name, int len, + uint32_t hash, uint32_t b, + int dir_nodeid, int from_nodeid, + unsigned int flags, struct dlm_rsb **r_ret) { - struct dlm_rsb *r; + struct dlm_rsb *r = NULL; + int our_nodeid = dlm_our_nodeid(); + int from_local = 0; + int from_other = 0; + int from_dir = 0; + int create = 0; int error; - error = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].keep, name, len, flags, &r); - if (!error) { - kref_get(&r->res_ref); - goto out; + if (flags & R_RECEIVE_REQUEST) { + if (from_nodeid == dir_nodeid) + from_dir = 1; + else + from_other = 1; + } else if (flags & R_REQUEST) { + from_local = 1; + } + + /* + * flags & R_RECEIVE_RECOVER is from dlm_recover_master_copy, so + * from_nodeid has sent us a lock in dlm_recover_locks, believing + * we're the new master. Our local recovery may not have set + * res_master_nodeid to our_nodeid yet, so allow either. Don't + * create the rsb; dlm_recover_process_copy() will handle EBADR + * by resending. + * + * If someone sends us a request, we are the dir node, and we do + * not find the rsb anywhere, then recreate it. This happens if + * someone sends us a request after we have removed/freed an rsb + * from our toss list. (They sent a request instead of lookup + * because they are using an rsb from their toss list.) + */ + + if (from_local || from_dir || + (from_other && (dir_nodeid == our_nodeid))) { + create = 1; } - if (error == -ENOTBLK) - goto out; - error = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].toss, name, len, flags, &r); + retry: + if (create) { + error = pre_rsb_struct(ls); + if (error < 0) + goto out; + } + + spin_lock(&ls->ls_rsbtbl[b].lock); + + error = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].keep, name, len, &r); if (error) - goto out; + goto do_toss; + + /* + * rsb is active, so we can't check master_nodeid without lock_rsb. + */ - rb_erase(&r->res_hashnode, &ls->ls_rsbtbl[b].toss); - error = rsb_insert(r, &ls->ls_rsbtbl[b].keep); + kref_get(&r->res_ref); + error = 0; + goto out_unlock; + + + do_toss: + error = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].toss, name, len, &r); if (error) - return error; + goto do_new; - if (dlm_no_directory(ls)) - goto out; + /* + * rsb found inactive (master_nodeid may be out of date unless + * we are the dir_nodeid or were the master) No other thread + * is using this rsb because it's on the toss list, so we can + * look at or update res_master_nodeid without lock_rsb. + */ - if (r->res_nodeid == -1) { + if ((r->res_master_nodeid != our_nodeid) && from_other) { + /* our rsb was not master, and another node (not the dir node) + has sent us a request */ + log_debug(ls, "find_rsb toss from_other %d master %d dir %d %s", + from_nodeid, r->res_master_nodeid, dir_nodeid, + r->res_name); + error = -ENOTBLK; + goto out_unlock; + } + + if ((r->res_master_nodeid != our_nodeid) && from_dir) { + /* don't think this should ever happen */ + log_error(ls, "find_rsb toss from_dir %d master %d", + from_nodeid, r->res_master_nodeid); + dlm_print_rsb(r); + /* fix it and go on */ + r->res_master_nodeid = our_nodeid; + r->res_nodeid = 0; rsb_clear_flag(r, RSB_MASTER_UNCERTAIN); r->res_first_lkid = 0; - } else if (r->res_nodeid > 0) { + } + + if (from_local && (r->res_master_nodeid != our_nodeid)) { + /* Because we have held no locks on this rsb, + res_master_nodeid could have become stale. */ rsb_set_flag(r, RSB_MASTER_UNCERTAIN); r->res_first_lkid = 0; + } + + rb_erase(&r->res_hashnode, &ls->ls_rsbtbl[b].toss); + error = rsb_insert(r, &ls->ls_rsbtbl[b].keep); + goto out_unlock; + + + do_new: + /* + * rsb not found + */ + + if (error == -EBADR && !create) + goto out_unlock; + + error = get_rsb_struct(ls, name, len, &r); + if (error == -EAGAIN) { + spin_unlock(&ls->ls_rsbtbl[b].lock); + goto retry; + } + if (error) + goto out_unlock; + + r->res_hash = hash; + r->res_bucket = b; + r->res_dir_nodeid = dir_nodeid; + kref_init(&r->res_ref); + + if (from_dir) { + /* want to see how often this happens */ + log_debug(ls, "find_rsb new from_dir %d recreate %s", + from_nodeid, r->res_name); + r->res_master_nodeid = our_nodeid; + r->res_nodeid = 0; + goto out_add; + } + + if (from_other && (dir_nodeid != our_nodeid)) { + /* should never happen */ + log_error(ls, "find_rsb new from_other %d dir %d our %d %s", + from_nodeid, dir_nodeid, our_nodeid, r->res_name); + dlm_free_rsb(r); + error = -ENOTBLK; + goto out_unlock; + } + + if (from_other) { + log_debug(ls, "find_rsb new from_other %d dir %d %s", + from_nodeid, dir_nodeid, r->res_name); + } + + if (dir_nodeid == our_nodeid) { + /* When we are the dir nodeid, we can set the master + node immediately */ + r->res_master_nodeid = our_nodeid; + r->res_nodeid = 0; } else { - DLM_ASSERT(r->res_nodeid == 0, dlm_print_rsb(r);); - DLM_ASSERT(!rsb_flag(r, RSB_MASTER_UNCERTAIN),); + /* set_master will send_lookup to dir_nodeid */ + r->res_master_nodeid = 0; + r->res_nodeid = -1; } + + out_add: + error = rsb_insert(r, &ls->ls_rsbtbl[b].keep); + out_unlock: + spin_unlock(&ls->ls_rsbtbl[b].lock); out: *r_ret = r; return error; } +/* During recovery, other nodes can send us new MSTCPY locks (from + dlm_recover_locks) before we've made ourself master (in + dlm_recover_masters). */ + +static int find_rsb_nodir(struct dlm_ls *ls, char *name, int len, + uint32_t hash, uint32_t b, + int dir_nodeid, int from_nodeid, + unsigned int flags, struct dlm_rsb **r_ret) +{ + struct dlm_rsb *r = NULL; + int our_nodeid = dlm_our_nodeid(); + int recover = (flags & R_RECEIVE_RECOVER); + int error; + + retry: + error = pre_rsb_struct(ls); + if (error < 0) + goto out; + + spin_lock(&ls->ls_rsbtbl[b].lock); + + error = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].keep, name, len, &r); + if (error) + goto do_toss; + + /* + * rsb is active, so we can't check master_nodeid without lock_rsb. + */ + + kref_get(&r->res_ref); + goto out_unlock; + + + do_toss: + error = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].toss, name, len, &r); + if (error) + goto do_new; + + /* + * rsb found inactive. No other thread is using this rsb because + * it's on the toss list, so we can look at or update + * res_master_nodeid without lock_rsb. + */ + + if (!recover && (r->res_master_nodeid != our_nodeid) && from_nodeid) { + /* our rsb is not master, and another node has sent us a + request; this should never happen */ + log_error(ls, "find_rsb toss from_nodeid %d master %d dir %d", + from_nodeid, r->res_master_nodeid, dir_nodeid); + dlm_print_rsb(r); + error = -ENOTBLK; + goto out_unlock; + } + + if (!recover && (r->res_master_nodeid != our_nodeid) && + (dir_nodeid == our_nodeid)) { + /* our rsb is not master, and we are dir; may as well fix it; + this should never happen */ + log_error(ls, "find_rsb toss our %d master %d dir %d", + our_nodeid, r->res_master_nodeid, dir_nodeid); + dlm_print_rsb(r); + r->res_master_nodeid = our_nodeid; + r->res_nodeid = 0; + } + + rb_erase(&r->res_hashnode, &ls->ls_rsbtbl[b].toss); + error = rsb_insert(r, &ls->ls_rsbtbl[b].keep); + goto out_unlock; + + + do_new: + /* + * rsb not found + */ + + error = get_rsb_struct(ls, name, len, &r); + if (error == -EAGAIN) { + spin_unlock(&ls->ls_rsbtbl[b].lock); + goto retry; + } + if (error) + goto out_unlock; + + r->res_hash = hash; + r->res_bucket = b; + r->res_dir_nodeid = dir_nodeid; + r->res_master_nodeid = dir_nodeid; + r->res_nodeid = (dir_nodeid == our_nodeid) ? 0 : dir_nodeid; + kref_init(&r->res_ref); + + error = rsb_insert(r, &ls->ls_rsbtbl[b].keep); + out_unlock: + spin_unlock(&ls->ls_rsbtbl[b].lock); + out: + *r_ret = r; + return error; +} + +static int find_rsb(struct dlm_ls *ls, char *name, int len, int from_nodeid, + unsigned int flags, struct dlm_rsb **r_ret) +{ + uint32_t hash, b; + int dir_nodeid; + + if (len > DLM_RESNAME_MAXLEN) + return -EINVAL; + + hash = jhash(name, len, 0); + b = hash & (ls->ls_rsbtbl_size - 1); + + dir_nodeid = dlm_hash2nodeid(ls, hash); + + if (dlm_no_directory(ls)) + return find_rsb_nodir(ls, name, len, hash, b, dir_nodeid, + from_nodeid, flags, r_ret); + else + return find_rsb_dir(ls, name, len, hash, b, dir_nodeid, + from_nodeid, flags, r_ret); +} + +/* we have received a request and found that res_master_nodeid != our_nodeid, + so we need to return an error or make ourself the master */ + +static int validate_master_nodeid(struct dlm_ls *ls, struct dlm_rsb *r, + int from_nodeid) +{ + if (dlm_no_directory(ls)) { + log_error(ls, "find_rsb keep from_nodeid %d master %d dir %d", + from_nodeid, r->res_master_nodeid, + r->res_dir_nodeid); + dlm_print_rsb(r); + return -ENOTBLK; + } + + if (from_nodeid != r->res_dir_nodeid) { + /* our rsb is not master, and another node (not the dir node) + has sent us a request. this is much more common when our + master_nodeid is zero, so limit debug to non-zero. */ + + if (r->res_master_nodeid) { + log_debug(ls, "validate master from_other %d master %d " + "dir %d first %x %s", from_nodeid, + r->res_master_nodeid, r->res_dir_nodeid, + r->res_first_lkid, r->res_name); + } + return -ENOTBLK; + } else { + /* our rsb is not master, but the dir nodeid has sent us a + request; this could happen with master 0 / res_nodeid -1 */ + + if (r->res_master_nodeid) { + log_error(ls, "validate master from_dir %d master %d " + "first %x %s", + from_nodeid, r->res_master_nodeid, + r->res_first_lkid, r->res_name); + } + + r->res_master_nodeid = dlm_our_nodeid(); + r->res_nodeid = 0; + return 0; + } +} + /* - * Find rsb in rsbtbl and potentially create/add one + * We're the dir node for this res and another node wants to know the + * master nodeid. During normal operation (non recovery) this is only + * called from receive_lookup(); master lookups when the local node is + * the dir node are done by find_rsb(). * - * Delaying the release of rsb's has a similar benefit to applications keeping - * NL locks on an rsb, but without the guarantee that the cached master value - * will still be valid when the rsb is reused. Apps aren't always smart enough - * to keep NL locks on an rsb that they may lock again shortly; this can lead - * to excessive master lookups and removals if we don't delay the release. + * normal operation, we are the dir node for a resource + * . _request_lock + * . set_master + * . send_lookup + * . receive_lookup + * . dlm_master_lookup flags 0 * - * Searching for an rsb means looking through both the normal list and toss - * list. When found on the toss list the rsb is moved to the normal list with - * ref count of 1; when found on normal list the ref count is incremented. + * recover directory, we are rebuilding dir for all resources + * . dlm_recover_directory + * . dlm_rcom_names + * remote node sends back the rsb names it is master of and we are dir of + * . dlm_master_lookup RECOVER_DIR (fix_master 0, from_master 1) + * we either create new rsb setting remote node as master, or find existing + * rsb and set master to be the remote node. + * + * recover masters, we are finding the new master for resources + * . dlm_recover_masters + * . recover_master + * . dlm_send_rcom_lookup + * . receive_rcom_lookup + * . dlm_master_lookup RECOVER_MASTER (fix_master 1, from_master 0) */ -static int find_rsb(struct dlm_ls *ls, char *name, int namelen, - unsigned int flags, struct dlm_rsb **r_ret) +int dlm_master_lookup(struct dlm_ls *ls, int from_nodeid, char *name, int len, + unsigned int flags, int *r_nodeid, int *result) { struct dlm_rsb *r = NULL; - uint32_t hash, bucket; - int error; + uint32_t hash, b; + int from_master = (flags & DLM_LU_RECOVER_DIR); + int fix_master = (flags & DLM_LU_RECOVER_MASTER); + int our_nodeid = dlm_our_nodeid(); + int dir_nodeid, error, toss_list = 0; - if (namelen > DLM_RESNAME_MAXLEN) { - error = -EINVAL; - goto out; + if (len > DLM_RESNAME_MAXLEN) + return -EINVAL; + + if (from_nodeid == our_nodeid) { + log_error(ls, "dlm_master_lookup from our_nodeid %d flags %x", + our_nodeid, flags); + return -EINVAL; } - if (dlm_no_directory(ls)) - flags |= R_CREATE; + hash = jhash(name, len, 0); + b = hash & (ls->ls_rsbtbl_size - 1); - hash = jhash(name, namelen, 0); - bucket = hash & (ls->ls_rsbtbl_size - 1); + dir_nodeid = dlm_hash2nodeid(ls, hash); + if (dir_nodeid != our_nodeid) { + log_error(ls, "dlm_master_lookup from %d dir %d our %d h %x %d", + from_nodeid, dir_nodeid, our_nodeid, hash, + ls->ls_num_nodes); + *r_nodeid = -1; + return -EINVAL; + } retry: - if (flags & R_CREATE) { - error = pre_rsb_struct(ls); - if (error < 0) - goto out; + error = pre_rsb_struct(ls); + if (error < 0) + return error; + + spin_lock(&ls->ls_rsbtbl[b].lock); + error = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].keep, name, len, &r); + if (!error) { + /* because the rsb is active, we need to lock_rsb before + checking/changing re_master_nodeid */ + + hold_rsb(r); + spin_unlock(&ls->ls_rsbtbl[b].lock); + lock_rsb(r); + goto found; } - spin_lock(&ls->ls_rsbtbl[bucket].lock); + error = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].toss, name, len, &r); + if (error) + goto not_found; - error = _search_rsb(ls, name, namelen, bucket, flags, &r); - if (!error) - goto out_unlock; + /* because the rsb is inactive (on toss list), it's not refcounted + and lock_rsb is not used, but is protected by the rsbtbl lock */ - if (error == -EBADR && !(flags & R_CREATE)) - goto out_unlock; + toss_list = 1; + found: + if (r->res_dir_nodeid != our_nodeid) { + /* should not happen, but may as well fix it and carry on */ + log_error(ls, "dlm_master_lookup res_dir %d our %d %s", + r->res_dir_nodeid, our_nodeid, r->res_name); + r->res_dir_nodeid = our_nodeid; + } + + if (fix_master && dlm_is_removed(ls, r->res_master_nodeid)) { + /* Recovery uses this function to set a new master when + the previous master failed. Setting NEW_MASTER will + force dlm_recover_masters to call recover_master on this + rsb even though the res_nodeid is no longer removed. */ + + r->res_master_nodeid = from_nodeid; + r->res_nodeid = from_nodeid; + rsb_set_flag(r, RSB_NEW_MASTER); + + if (toss_list) { + /* I don't think we should ever find it on toss list. */ + log_error(ls, "dlm_master_lookup fix_master on toss"); + dlm_dump_rsb(r); + } + } - /* the rsb was found but wasn't a master copy */ - if (error == -ENOTBLK) - goto out_unlock; + if (from_master && (r->res_master_nodeid != from_nodeid)) { + /* this will happen if from_nodeid became master during + a previous recovery cycle, and we aborted the previous + cycle before recovering this master value */ - error = get_rsb_struct(ls, name, namelen, &r); + log_limit(ls, "dlm_master_lookup from_master %d " + "master_nodeid %d res_nodeid %d first %x %s", + from_nodeid, r->res_master_nodeid, r->res_nodeid, + r->res_first_lkid, r->res_name); + + if (r->res_master_nodeid == our_nodeid) { + log_error(ls, "from_master %d our_master", from_nodeid); + dlm_dump_rsb(r); + dlm_send_rcom_lookup_dump(r, from_nodeid); + goto out_found; + } + + r->res_master_nodeid = from_nodeid; + r->res_nodeid = from_nodeid; + rsb_set_flag(r, RSB_NEW_MASTER); + } + + if (!r->res_master_nodeid) { + /* this will happen if recovery happens while we're looking + up the master for this rsb */ + + log_debug(ls, "dlm_master_lookup master 0 to %d first %x %s", + from_nodeid, r->res_first_lkid, r->res_name); + r->res_master_nodeid = from_nodeid; + r->res_nodeid = from_nodeid; + } + + if (!from_master && !fix_master && + (r->res_master_nodeid == from_nodeid)) { + /* this can happen when the master sends remove, the dir node + finds the rsb on the keep list and ignores the remove, + and the former master sends a lookup */ + + log_limit(ls, "dlm_master_lookup from master %d flags %x " + "first %x %s", from_nodeid, flags, + r->res_first_lkid, r->res_name); + } + + out_found: + *r_nodeid = r->res_master_nodeid; + if (result) + *result = DLM_LU_MATCH; + + if (toss_list) { + r->res_toss_time = jiffies; + /* the rsb was inactive (on toss list) */ + spin_unlock(&ls->ls_rsbtbl[b].lock); + } else { + /* the rsb was active */ + unlock_rsb(r); + put_rsb(r); + } + return 0; + + not_found: + error = get_rsb_struct(ls, name, len, &r); if (error == -EAGAIN) { - spin_unlock(&ls->ls_rsbtbl[bucket].lock); + spin_unlock(&ls->ls_rsbtbl[b].lock); goto retry; } if (error) goto out_unlock; r->res_hash = hash; - r->res_bucket = bucket; - r->res_nodeid = -1; + r->res_bucket = b; + r->res_dir_nodeid = our_nodeid; + r->res_master_nodeid = from_nodeid; + r->res_nodeid = from_nodeid; kref_init(&r->res_ref); + r->res_toss_time = jiffies; - /* With no directory, the master can be set immediately */ - if (dlm_no_directory(ls)) { - int nodeid = dlm_dir_nodeid(r); - if (nodeid == dlm_our_nodeid()) - nodeid = 0; - r->res_nodeid = nodeid; + error = rsb_insert(r, &ls->ls_rsbtbl[b].toss); + if (error) { + /* should never happen */ + dlm_free_rsb(r); + spin_unlock(&ls->ls_rsbtbl[b].lock); + goto retry; } - error = rsb_insert(r, &ls->ls_rsbtbl[bucket].keep); + + if (result) + *result = DLM_LU_ADD; + *r_nodeid = from_nodeid; + error = 0; out_unlock: - spin_unlock(&ls->ls_rsbtbl[bucket].lock); - out: - *r_ret = r; + spin_unlock(&ls->ls_rsbtbl[b].lock); return error; } @@ -605,17 +1099,27 @@ static void dlm_dump_rsb_hash(struct dlm_ls *ls, uint32_t hash) } } -/* This is only called to add a reference when the code already holds - a valid reference to the rsb, so there's no need for locking. */ - -static inline void hold_rsb(struct dlm_rsb *r) +void dlm_dump_rsb_name(struct dlm_ls *ls, char *name, int len) { - kref_get(&r->res_ref); -} + struct dlm_rsb *r = NULL; + uint32_t hash, b; + int error; -void dlm_hold_rsb(struct dlm_rsb *r) -{ - hold_rsb(r); + hash = jhash(name, len, 0); + b = hash & (ls->ls_rsbtbl_size - 1); + + spin_lock(&ls->ls_rsbtbl[b].lock); + error = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].keep, name, len, &r); + if (!error) + goto out_dump; + + error = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].toss, name, len, &r); + if (error) + goto out; + out_dump: + dlm_dump_rsb(r); + out: + spin_unlock(&ls->ls_rsbtbl[b].lock); } static void toss_rsb(struct kref *kref) @@ -634,24 +1138,6 @@ static void toss_rsb(struct kref *kref) } } -/* When all references to the rsb are gone it's transferred to - the tossed list for later disposal. */ - -static void put_rsb(struct dlm_rsb *r) -{ - struct dlm_ls *ls = r->res_ls; - uint32_t bucket = r->res_bucket; - - spin_lock(&ls->ls_rsbtbl[bucket].lock); - kref_put(&r->res_ref, toss_rsb); - spin_unlock(&ls->ls_rsbtbl[bucket].lock); -} - -void dlm_put_rsb(struct dlm_rsb *r) -{ - put_rsb(r); -} - /* See comment for unhold_lkb */ static void unhold_rsb(struct dlm_rsb *r) @@ -1138,27 +1624,13 @@ static int remove_from_waiters_ms(struct dlm_lkb *lkb, struct dlm_message *ms) return error; } -static void dir_remove(struct dlm_rsb *r) -{ - int to_nodeid; - - if (dlm_no_directory(r->res_ls)) - return; - - to_nodeid = dlm_dir_nodeid(r); - if (to_nodeid != dlm_our_nodeid()) - send_remove(r); - else - dlm_dir_remove_entry(r->res_ls, to_nodeid, - r->res_name, r->res_length); -} - /* FIXME: make this more efficient */ static int shrink_bucket(struct dlm_ls *ls, int b) { struct rb_node *n; struct dlm_rsb *r; + int our_nodeid = dlm_our_nodeid(); int count = 0, found; for (;;) { @@ -1166,6 +1638,17 @@ static int shrink_bucket(struct dlm_ls *ls, int b) spin_lock(&ls->ls_rsbtbl[b].lock); for (n = rb_first(&ls->ls_rsbtbl[b].toss); n; n = rb_next(n)) { r = rb_entry(n, struct dlm_rsb, res_hashnode); + + /* If we're the directory record for this rsb, and + we're not the master of it, then we need to wait + for the master node to send us a dir remove for + before removing the dir record. */ + + if (!dlm_no_directory(ls) && !is_master(r) && + (dlm_dir_nodeid(r) == our_nodeid)) { + continue; + } + if (!time_after_eq(jiffies, r->res_toss_time + dlm_config.ci_toss_secs * HZ)) continue; @@ -1182,8 +1665,15 @@ static int shrink_bucket(struct dlm_ls *ls, int b) rb_erase(&r->res_hashnode, &ls->ls_rsbtbl[b].toss); spin_unlock(&ls->ls_rsbtbl[b].lock); - if (is_master(r)) - dir_remove(r); + /* We're the master of this rsb but we're not + the directory record, so we need to tell the + dir node to remove the dir record. */ + + if (!dlm_no_directory(ls) && is_master(r) && + (dlm_dir_nodeid(r) != our_nodeid)) { + send_remove(r); + } + dlm_free_rsb(r); count++; } else { @@ -2078,8 +2568,7 @@ static void send_blocking_asts_all(struct dlm_rsb *r, struct dlm_lkb *lkb) static int set_master(struct dlm_rsb *r, struct dlm_lkb *lkb) { - struct dlm_ls *ls = r->res_ls; - int i, error, dir_nodeid, ret_nodeid, our_nodeid = dlm_our_nodeid(); + int our_nodeid = dlm_our_nodeid(); if (rsb_flag(r, RSB_MASTER_UNCERTAIN)) { rsb_clear_flag(r, RSB_MASTER_UNCERTAIN); @@ -2093,53 +2582,35 @@ static int set_master(struct dlm_rsb *r, struct dlm_lkb *lkb) return 1; } - if (r->res_nodeid == 0) { + if (r->res_master_nodeid == our_nodeid) { lkb->lkb_nodeid = 0; return 0; } - if (r->res_nodeid > 0) { - lkb->lkb_nodeid = r->res_nodeid; + if (r->res_master_nodeid) { + lkb->lkb_nodeid = r->res_master_nodeid; return 0; } - DLM_ASSERT(r->res_nodeid == -1, dlm_dump_rsb(r);); - - dir_nodeid = dlm_dir_nodeid(r); - - if (dir_nodeid != our_nodeid) { - r->res_first_lkid = lkb->lkb_id; - send_lookup(r, lkb); - return 1; - } - - for (i = 0; i < 2; i++) { - /* It's possible for dlm_scand to remove an old rsb for - this same resource from the toss list, us to create - a new one, look up the master locally, and find it - already exists just before dlm_scand does the - dir_remove() on the previous rsb. */ - - error = dlm_dir_lookup(ls, our_nodeid, r->res_name, - r->res_length, &ret_nodeid); - if (!error) - break; - log_debug(ls, "dir_lookup error %d %s", error, r->res_name); - schedule(); - } - if (error && error != -EEXIST) - return error; - - if (ret_nodeid == our_nodeid) { - r->res_first_lkid = 0; + if (dlm_dir_nodeid(r) == our_nodeid) { + /* This is a somewhat unusual case; find_rsb will usually + have set res_master_nodeid when dir nodeid is local, but + there are cases where we become the dir node after we've + past find_rsb and go through _request_lock again. + confirm_master() or process_lookup_list() needs to be + called after this. */ + log_debug(r->res_ls, "set_master %x self master %d dir %d %s", + lkb->lkb_id, r->res_master_nodeid, r->res_dir_nodeid, + r->res_name); + r->res_master_nodeid = our_nodeid; r->res_nodeid = 0; lkb->lkb_nodeid = 0; - } else { - r->res_first_lkid = lkb->lkb_id; - r->res_nodeid = ret_nodeid; - lkb->lkb_nodeid = ret_nodeid; + return 0; } - return 0; + + r->res_first_lkid = lkb->lkb_id; + send_lookup(r, lkb); + return 1; } static void process_lookup_list(struct dlm_rsb *r) @@ -2584,7 +3055,7 @@ static void do_unlock_effects(struct dlm_rsb *r, struct dlm_lkb *lkb, } /* returns: 0 did nothing, -DLM_ECANCEL canceled lock */ - + static int do_cancel(struct dlm_rsb *r, struct dlm_lkb *lkb) { int error; @@ -2708,11 +3179,11 @@ static int request_lock(struct dlm_ls *ls, struct dlm_lkb *lkb, char *name, error = validate_lock_args(ls, lkb, args); if (error) - goto out; + return error; - error = find_rsb(ls, name, len, R_CREATE, &r); + error = find_rsb(ls, name, len, 0, R_REQUEST, &r); if (error) - goto out; + return error; lock_rsb(r); @@ -2723,8 +3194,6 @@ static int request_lock(struct dlm_ls *ls, struct dlm_lkb *lkb, char *name, unlock_rsb(r); put_rsb(r); - - out: return error; } @@ -3406,8 +3875,11 @@ static int receive_request(struct dlm_ls *ls, struct dlm_message *ms) { struct dlm_lkb *lkb; struct dlm_rsb *r; + int from_nodeid; int error, namelen; + from_nodeid = ms->m_header.h_nodeid; + error = create_lkb(ls, &lkb); if (error) goto fail; @@ -3420,9 +3892,16 @@ static int receive_request(struct dlm_ls *ls, struct dlm_message *ms) goto fail; } + /* The dir node is the authority on whether we are the master + for this rsb or not, so if the master sends us a request, we should + recreate the rsb if we've destroyed it. This race happens when we + send a remove message to the dir node at the same time that the dir + node sends us a request for the rsb. */ + namelen = receive_extralen(ms); - error = find_rsb(ls, ms->m_extra, namelen, R_MASTER, &r); + error = find_rsb(ls, ms->m_extra, namelen, from_nodeid, + R_RECEIVE_REQUEST, &r); if (error) { __put_lkb(ls, lkb); goto fail; @@ -3430,6 +3909,16 @@ static int receive_request(struct dlm_ls *ls, struct dlm_message *ms) lock_rsb(r); + if (r->res_master_nodeid != dlm_our_nodeid()) { + error = validate_master_nodeid(ls, r, from_nodeid); + if (error) { + unlock_rsb(r); + put_rsb(r); + __put_lkb(ls, lkb); + goto fail; + } + } + attach_lkb(r, lkb); error = do_request(r, lkb); send_request_reply(r, lkb, error); @@ -3445,6 +3934,23 @@ static int receive_request(struct dlm_ls *ls, struct dlm_message *ms) return 0; fail: + /* TODO: instead of returning ENOTBLK, add the lkb to res_lookup + and do this receive_request again from process_lookup_list once + we get the lookup reply. This would avoid a many repeated + ENOTBLK request failures when the lookup reply designating us + as master is delayed. */ + + /* We could repeatedly return -EBADR here if our send_remove() is + delayed in being sent/arriving/being processed on the dir node. + Another node would repeatedly lookup up the master, and the dir + node would continue returning our nodeid until our send_remove + took effect. */ + + if (error != -ENOTBLK) { + log_limit(ls, "receive_request %x from %d %d", + ms->m_lkid, from_nodeid, error); + } + setup_stub_lkb(ls, ms); send_request_reply(&ls->ls_stub_rsb, &ls->ls_stub_lkb, error); return error; @@ -3651,49 +4157,110 @@ static int receive_bast(struct dlm_ls *ls, struct dlm_message *ms) static void receive_lookup(struct dlm_ls *ls, struct dlm_message *ms) { - int len, error, ret_nodeid, dir_nodeid, from_nodeid, our_nodeid; + int len, error, ret_nodeid, from_nodeid, our_nodeid; from_nodeid = ms->m_header.h_nodeid; our_nodeid = dlm_our_nodeid(); len = receive_extralen(ms); - dir_nodeid = dlm_hash2nodeid(ls, ms->m_hash); - if (dir_nodeid != our_nodeid) { - log_error(ls, "lookup dir_nodeid %d from %d", - dir_nodeid, from_nodeid); - error = -EINVAL; - ret_nodeid = -1; - goto out; - } - - error = dlm_dir_lookup(ls, from_nodeid, ms->m_extra, len, &ret_nodeid); + error = dlm_master_lookup(ls, from_nodeid, ms->m_extra, len, 0, + &ret_nodeid, NULL); /* Optimization: we're master so treat lookup as a request */ if (!error && ret_nodeid == our_nodeid) { receive_request(ls, ms); return; } - out: send_lookup_reply(ls, ms, ret_nodeid, error); } static void receive_remove(struct dlm_ls *ls, struct dlm_message *ms) { - int len, dir_nodeid, from_nodeid; + char name[DLM_RESNAME_MAXLEN+1]; + struct dlm_rsb *r; + uint32_t hash, b; + int rv, len, dir_nodeid, from_nodeid; from_nodeid = ms->m_header.h_nodeid; len = receive_extralen(ms); + if (len > DLM_RESNAME_MAXLEN) { + log_error(ls, "receive_remove from %d bad len %d", + from_nodeid, len); + return; + } + dir_nodeid = dlm_hash2nodeid(ls, ms->m_hash); if (dir_nodeid != dlm_our_nodeid()) { - log_error(ls, "remove dir entry dir_nodeid %d from %d", - dir_nodeid, from_nodeid); + log_error(ls, "receive_remove from %d bad nodeid %d", + from_nodeid, dir_nodeid); return; } - dlm_dir_remove_entry(ls, from_nodeid, ms->m_extra, len); + /* Look for name on rsbtbl.toss, if it's there, kill it. + If it's on rsbtbl.keep, it's being used, and we should ignore this + message. This is an expected race between the dir node sending a + request to the master node at the same time as the master node sends + a remove to the dir node. The resolution to that race is for the + dir node to ignore the remove message, and the master node to + recreate the master rsb when it gets a request from the dir node for + an rsb it doesn't have. */ + + memset(name, 0, sizeof(name)); + memcpy(name, ms->m_extra, len); + + hash = jhash(name, len, 0); + b = hash & (ls->ls_rsbtbl_size - 1); + + spin_lock(&ls->ls_rsbtbl[b].lock); + + rv = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].toss, name, len, &r); + if (rv) { + /* verify the rsb is on keep list per comment above */ + rv = dlm_search_rsb_tree(&ls->ls_rsbtbl[b].keep, name, len, &r); + if (rv) { + /* should not happen */ + log_error(ls, "receive_remove from %d not found %s", + from_nodeid, name); + spin_unlock(&ls->ls_rsbtbl[b].lock); + return; + } + if (r->res_master_nodeid != from_nodeid) { + /* should not happen */ + log_error(ls, "receive_remove keep from %d master %d", + from_nodeid, r->res_master_nodeid); + dlm_print_rsb(r); + spin_unlock(&ls->ls_rsbtbl[b].lock); + return; + } + + log_debug(ls, "receive_remove from %d master %d first %x %s", + from_nodeid, r->res_master_nodeid, r->res_first_lkid, + name); + spin_unlock(&ls->ls_rsbtbl[b].lock); + return; + } + + if (r->res_master_nodeid != from_nodeid) { + log_error(ls, "receive_remove toss from %d master %d", + from_nodeid, r->res_master_nodeid); + dlm_print_rsb(r); + spin_unlock(&ls->ls_rsbtbl[b].lock); + return; + } + + if (kref_put(&r->res_ref, kill_rsb)) { + rb_erase(&r->res_hashnode, &ls->ls_rsbtbl[b].toss); + spin_unlock(&ls->ls_rsbtbl[b].lock); + dlm_free_rsb(r); + } else { + log_error(ls, "receive_remove from %d rsb ref error", + from_nodeid); + dlm_print_rsb(r); + spin_unlock(&ls->ls_rsbtbl[b].lock); + } } static void receive_purge(struct dlm_ls *ls, struct dlm_message *ms) @@ -3706,6 +4273,7 @@ static int receive_request_reply(struct dlm_ls *ls, struct dlm_message *ms) struct dlm_lkb *lkb; struct dlm_rsb *r; int error, mstype, result; + int from_nodeid = ms->m_header.h_nodeid; error = find_lkb(ls, ms->m_remid, &lkb); if (error) @@ -3723,8 +4291,7 @@ static int receive_request_reply(struct dlm_ls *ls, struct dlm_message *ms) error = remove_from_waiters(lkb, DLM_MSG_REQUEST_REPLY); if (error) { log_error(ls, "receive_request_reply %x remote %d %x result %d", - lkb->lkb_id, ms->m_header.h_nodeid, ms->m_lkid, - ms->m_result); + lkb->lkb_id, from_nodeid, ms->m_lkid, ms->m_result); dlm_dump_rsb(r); goto out; } @@ -3732,8 +4299,9 @@ static int receive_request_reply(struct dlm_ls *ls, struct dlm_message *ms) /* Optimization: the dir node was also the master, so it took our lookup as a request and sent request reply instead of lookup reply */ if (mstype == DLM_MSG_LOOKUP) { - r->res_nodeid = ms->m_header.h_nodeid; - lkb->lkb_nodeid = r->res_nodeid; + r->res_master_nodeid = from_nodeid; + r->res_nodeid = from_nodeid; + lkb->lkb_nodeid = from_nodeid; } /* this is the value returned from do_request() on the master */ @@ -3767,18 +4335,30 @@ static int receive_request_reply(struct dlm_ls *ls, struct dlm_message *ms) case -EBADR: case -ENOTBLK: /* find_rsb failed to find rsb or rsb wasn't master */ - log_debug(ls, "receive_request_reply %x %x master diff %d %d", - lkb->lkb_id, lkb->lkb_flags, r->res_nodeid, result); - r->res_nodeid = -1; - lkb->lkb_nodeid = -1; + log_limit(ls, "receive_request_reply %x from %d %d " + "master %d dir %d first %x %s", lkb->lkb_id, + from_nodeid, result, r->res_master_nodeid, + r->res_dir_nodeid, r->res_first_lkid, r->res_name); + + if (r->res_dir_nodeid != dlm_our_nodeid() && + r->res_master_nodeid != dlm_our_nodeid()) { + /* cause _request_lock->set_master->send_lookup */ + r->res_master_nodeid = 0; + r->res_nodeid = -1; + lkb->lkb_nodeid = -1; + } if (is_overlap(lkb)) { /* we'll ignore error in cancel/unlock reply */ queue_cast_overlap(r, lkb); confirm_master(r, result); unhold_lkb(lkb); /* undoes create_lkb() */ - } else + } else { _request_lock(r, lkb); + + if (r->res_master_nodeid == dlm_our_nodeid()) + confirm_master(r, 0); + } break; default: @@ -3994,6 +4574,7 @@ static void receive_lookup_reply(struct dlm_ls *ls, struct dlm_message *ms) struct dlm_lkb *lkb; struct dlm_rsb *r; int error, ret_nodeid; + int do_lookup_list = 0; error = find_lkb(ls, ms->m_lkid, &lkb); if (error) { @@ -4001,7 +4582,7 @@ static void receive_lookup_reply(struct dlm_ls *ls, struct dlm_message *ms) return; } - /* ms->m_result is the value returned by dlm_dir_lookup on dir node + /* ms->m_result is the value returned by dlm_master_lookup on dir node FIXME: will a non-zero error ever be returned? */ r = lkb->lkb_resource; @@ -4013,12 +4594,37 @@ static void receive_lookup_reply(struct dlm_ls *ls, struct dlm_message *ms) goto out; ret_nodeid = ms->m_nodeid; + + /* We sometimes receive a request from the dir node for this + rsb before we've received the dir node's loookup_reply for it. + The request from the dir node implies we're the master, so we set + ourself as master in receive_request_reply, and verify here that + we are indeed the master. */ + + if (r->res_master_nodeid && (r->res_master_nodeid != ret_nodeid)) { + /* This should never happen */ + log_error(ls, "receive_lookup_reply %x from %d ret %d " + "master %d dir %d our %d first %x %s", + lkb->lkb_id, ms->m_header.h_nodeid, ret_nodeid, + r->res_master_nodeid, r->res_dir_nodeid, + dlm_our_nodeid(), r->res_first_lkid, r->res_name); + } + if (ret_nodeid == dlm_our_nodeid()) { + r->res_master_nodeid = ret_nodeid; r->res_nodeid = 0; - ret_nodeid = 0; + do_lookup_list = 1; r->res_first_lkid = 0; + } else if (ret_nodeid == -1) { + /* the remote node doesn't believe it's the dir node */ + log_error(ls, "receive_lookup_reply %x from %d bad ret_nodeid", + lkb->lkb_id, ms->m_header.h_nodeid); + r->res_master_nodeid = 0; + r->res_nodeid = -1; + lkb->lkb_nodeid = -1; } else { - /* set_master() will copy res_nodeid to lkb_nodeid */ + /* set_master() will set lkb_nodeid from r */ + r->res_master_nodeid = ret_nodeid; r->res_nodeid = ret_nodeid; } @@ -4033,7 +4639,7 @@ static void receive_lookup_reply(struct dlm_ls *ls, struct dlm_message *ms) _request_lock(r, lkb); out_list: - if (!ret_nodeid) + if (do_lookup_list) process_lookup_list(r); out: unlock_rsb(r); @@ -4047,7 +4653,7 @@ static void _receive_message(struct dlm_ls *ls, struct dlm_message *ms, int error = 0, noent = 0; if (!dlm_is_member(ls, ms->m_header.h_nodeid)) { - log_debug(ls, "ignore non-member message %d from %d %x %x %d", + log_limit(ls, "receive %d from non-member %d %x %x %d", ms->m_type, ms->m_header.h_nodeid, ms->m_lkid, ms->m_remid, ms->m_result); return; @@ -4174,6 +4780,15 @@ static void dlm_receive_message(struct dlm_ls *ls, struct dlm_message *ms, int nodeid) { if (dlm_locking_stopped(ls)) { + /* If we were a member of this lockspace, left, and rejoined, + other nodes may still be sending us messages from the + lockspace generation before we left. */ + if (!ls->ls_generation) { + log_limit(ls, "receive %d from %d ignore old gen", + ms->m_type, nodeid); + return; + } + dlm_add_requestqueue(ls, nodeid, ms); } else { dlm_wait_requestqueue(ls); @@ -4798,6 +5413,7 @@ int dlm_recover_master_copy(struct dlm_ls *ls, struct dlm_rcom *rc) struct dlm_rsb *r; struct dlm_lkb *lkb; uint32_t remid = 0; + int from_nodeid = rc->rc_header.h_nodeid; int error; if (rl->rl_parent_lkid) { @@ -4815,21 +5431,21 @@ int dlm_recover_master_copy(struct dlm_ls *ls, struct dlm_rcom *rc) we make ourselves master, dlm_recover_masters() won't touch the MSTCPY locks we've received early. */ - error = find_rsb(ls, rl->rl_name, le16_to_cpu(rl->rl_namelen), 0, &r); + error = find_rsb(ls, rl->rl_name, le16_to_cpu(rl->rl_namelen), + from_nodeid, R_RECEIVE_RECOVER, &r); if (error) goto out; + lock_rsb(r); + if (dlm_no_directory(ls) && (dlm_dir_nodeid(r) != dlm_our_nodeid())) { log_error(ls, "dlm_recover_master_copy remote %d %x not dir", - rc->rc_header.h_nodeid, remid); + from_nodeid, remid); error = -EBADR; - put_rsb(r); - goto out; + goto out_unlock; } - lock_rsb(r); - - lkb = search_remid(r, rc->rc_header.h_nodeid, remid); + lkb = search_remid(r, from_nodeid, remid); if (lkb) { error = -EEXIST; goto out_remid; @@ -4866,7 +5482,7 @@ int dlm_recover_master_copy(struct dlm_ls *ls, struct dlm_rcom *rc) out: if (error && error != -EEXIST) log_debug(ls, "dlm_recover_master_copy remote %d %x error %d", - rc->rc_header.h_nodeid, remid, error); + from_nodeid, remid, error); rl->rl_result = cpu_to_le32(error); return error; } |