diff options
Diffstat (limited to 'xlators/mgmt/glusterd/src/glusterd-locks.c')
| -rw-r--r-- | xlators/mgmt/glusterd/src/glusterd-locks.c | 637 |
1 files changed, 637 insertions, 0 deletions
diff --git a/xlators/mgmt/glusterd/src/glusterd-locks.c b/xlators/mgmt/glusterd/src/glusterd-locks.c new file mode 100644 index 000000000..0af2a186f --- /dev/null +++ b/xlators/mgmt/glusterd/src/glusterd-locks.c @@ -0,0 +1,637 @@ +/* + Copyright (c) 2013-2014 Red Hat, Inc. <http://www.redhat.com> + This file is part of GlusterFS. + + This file is licensed to you under your choice of the GNU Lesser + General Public License, version 3 or any later version (LGPLv3 or + later), or the GNU General Public License, version 2 (GPLv2), in all + cases as published by the Free Software Foundation. +*/ +#ifndef _CONFIG_H +#define _CONFIG_H +#include "config.h" +#endif + +#include "common-utils.h" +#include "cli1-xdr.h" +#include "xdr-generic.h" +#include "glusterd.h" +#include "glusterd-op-sm.h" +#include "glusterd-store.h" +#include "glusterd-utils.h" +#include "glusterd-volgen.h" +#include "glusterd-locks.h" +#include "run.h" +#include "syscall.h" + +#include <signal.h> + +#define GF_MAX_LOCKING_ENTITIES 2 + +/* Valid entities that the mgmt_v3 lock can hold locks upon * + * To add newer entities to be locked, we can just add more * + * entries to this table along with the type and default value */ +valid_entities valid_types[] = { + { "vol", _gf_true }, + { "snap", _gf_false }, + { NULL }, +}; + +static dict_t *mgmt_v3_lock; + +/* Checks if the lock request is for a valid entity */ +gf_boolean_t +glusterd_mgmt_v3_is_type_valid (char *type) +{ + int32_t i = 0; + gf_boolean_t ret = _gf_false; + + GF_ASSERT (type); + + for (i = 0; valid_types[i].type; i++) { + if (!strcmp (type, valid_types[i].type)) { + ret = _gf_true; + break; + } + } + + return ret; +} + +/* Initialize the global mgmt_v3 lock list(dict) when + * glusterd is spawned */ +int32_t +glusterd_mgmt_v3_lock_init () +{ + int32_t ret = -1; + + mgmt_v3_lock = dict_new (); + if (!mgmt_v3_lock) { + ret = -1; + goto out; + } + + ret = 0; +out: + return ret; +} + +/* Destroy the global mgmt_v3 lock list(dict) when + * glusterd cleanup is performed */ +void +glusterd_mgmt_v3_lock_fini () +{ + if (mgmt_v3_lock) + dict_destroy (mgmt_v3_lock); +} + +int32_t +glusterd_get_mgmt_v3_lock_owner (char *key, uuid_t *uuid) +{ + int32_t ret = -1; + mgmt_v3_lock_obj *lock_obj = NULL; + uuid_t no_owner = {"\0"}; + xlator_t *this = NULL; + + GF_ASSERT(THIS); + this = THIS; + + if (!key || !uuid) { + gf_log (this->name, GF_LOG_ERROR, "key or uuid is null."); + ret = -1; + goto out; + } + + ret = dict_get_bin(mgmt_v3_lock, key, (void **) &lock_obj); + if (!ret) + uuid_copy (*uuid, lock_obj->lock_owner); + else + uuid_copy (*uuid, no_owner); + + ret = 0; +out: + gf_log (this->name, GF_LOG_TRACE, "Returning %d", ret); + return ret; +} + +/* This function is called with the locked_count and type, to * + * release all the acquired locks. */ +static int32_t +glusterd_release_multiple_locks_per_entity (dict_t *dict, uuid_t uuid, + int32_t locked_count, + char *type) +{ + char name_buf[PATH_MAX] = ""; + char *name = NULL; + int32_t i = -1; + int32_t op_ret = 0; + int32_t ret = -1; + xlator_t *this = NULL; + + this = THIS; + GF_ASSERT(this); + GF_ASSERT (dict); + GF_ASSERT (type); + + if (locked_count == 0) { + gf_log (this->name, GF_LOG_DEBUG, + "No %s locked as part of this transaction", + type); + goto out; + } + + /* Release all the locks held */ + for (i = 0; i < locked_count; i++) { + snprintf (name_buf, sizeof(name_buf), + "%sname%d", type, i+1); + + /* Looking for volname1, volname2 or snapname1, * + * as key in the dict snapname2 */ + ret = dict_get_str (dict, name_buf, &name); + if (ret) { + gf_log (this->name, GF_LOG_ERROR, + "Unable to get %s locked_count = %d", + name_buf, locked_count); + op_ret = ret; + continue; + } + + ret = glusterd_mgmt_v3_unlock (name, uuid, type); + if (ret) { + gf_log (this->name, GF_LOG_ERROR, + "Failed to release lock for %s.", + name); + op_ret = ret; + } + } + +out: + gf_log (this->name, GF_LOG_TRACE, "Returning %d", op_ret); + return op_ret; +} + +/* Given the count and type of the entity this function acquires * + * locks on multiple elements of the same entity. For example: * + * If type is "vol" this function tries to acquire locks on multiple * + * volumes */ +static int32_t +glusterd_acquire_multiple_locks_per_entity (dict_t *dict, uuid_t uuid, + int32_t count, char *type) +{ + char name_buf[PATH_MAX] = ""; + char *name = NULL; + int32_t i = -1; + int32_t ret = -1; + int32_t locked_count = 0; + xlator_t *this = NULL; + + this = THIS; + GF_ASSERT(this); + GF_ASSERT (dict); + GF_ASSERT (type); + + /* Locking one element after other */ + for (i = 0; i < count; i++) { + snprintf (name_buf, sizeof(name_buf), + "%sname%d", type, i+1); + + /* Looking for volname1, volname2 or snapname1, * + * as key in the dict snapname2 */ + ret = dict_get_str (dict, name_buf, &name); + if (ret) { + gf_log (this->name, GF_LOG_ERROR, + "Unable to get %s count = %d", + name_buf, count); + break; + } + + ret = glusterd_mgmt_v3_lock (name, uuid, type); + if (ret) { + gf_log (this->name, GF_LOG_ERROR, + "Failed to acquire lock for %s %s " + "on behalf of %s. Reversing " + "this transaction", type, name, + uuid_utoa(uuid)); + break; + } + locked_count++; + } + + if (count == locked_count) { + /* If all locking ops went successfuly, return as success */ + ret = 0; + goto out; + } + + /* If we failed to lock one element, unlock others and return failure */ + ret = glusterd_release_multiple_locks_per_entity (dict, uuid, + locked_count, + type); + if (ret) { + gf_log (this->name, GF_LOG_ERROR, + "Failed to release multiple %s locks", + type); + } + ret = -1; +out: + gf_log (this->name, GF_LOG_TRACE, "Returning %d", ret); + return ret; +} + +/* Given the type of entity, this function figures out if it should unlock a * + * single element of multiple elements of the said entity. For example: * + * if the type is "vol", this function will accordingly unlock a single volume * + * or multiple volumes */ +static int32_t +glusterd_mgmt_v3_unlock_entity (dict_t *dict, uuid_t uuid, char *type, + gf_boolean_t default_value) +{ + char name_buf[PATH_MAX] = ""; + char *name = NULL; + int32_t count = -1; + int32_t ret = -1; + gf_boolean_t hold_locks = _gf_false; + xlator_t *this = NULL; + + this = THIS; + GF_ASSERT(this); + GF_ASSERT (dict); + GF_ASSERT (type); + + snprintf (name_buf, sizeof(name_buf), "hold_%s_locks", type); + hold_locks = dict_get_str_boolean (dict, name_buf, default_value); + + if (hold_locks == _gf_false) { + /* Locks were not held for this particular entity * + * Hence nothing to release */ + ret = 0; + goto out; + } + + /* Looking for volcount or snapcount in the dict */ + snprintf (name_buf, sizeof(name_buf), "%scount", type); + ret = dict_get_int32 (dict, name_buf, &count); + if (ret) { + /* count is not present. Only one * + * element name needs to be unlocked */ + snprintf (name_buf, sizeof(name_buf), "%sname", + type); + ret = dict_get_str (dict, name_buf, &name); + if (ret) { + gf_log (this->name, GF_LOG_ERROR, + "Unable to fetch %sname", type); + goto out; + } + + ret = glusterd_mgmt_v3_unlock (name, uuid, type); + if (ret) { + gf_log (this->name, GF_LOG_ERROR, + "Failed to release lock for %s %s " + "on behalf of %s.", type, name, + uuid_utoa(uuid)); + goto out; + } + } else { + /* Unlocking one element name after another */ + ret = glusterd_release_multiple_locks_per_entity (dict, + uuid, + count, + type); + if (ret) { + gf_log (this->name, GF_LOG_ERROR, + "Failed to release all %s locks", type); + goto out; + } + } + + ret = 0; +out: + gf_log (this->name, GF_LOG_TRACE, "Returning %d", ret); + return ret; +} + +/* Given the type of entity, this function figures out if it should lock a * + * single element or multiple elements of the said entity. For example: * + * if the type is "vol", this function will accordingly lock a single volume * + * or multiple volumes */ +static int32_t +glusterd_mgmt_v3_lock_entity (dict_t *dict, uuid_t uuid, char *type, + gf_boolean_t default_value) +{ + char name_buf[PATH_MAX] = ""; + char *name = NULL; + int32_t count = -1; + int32_t ret = -1; + gf_boolean_t hold_locks = _gf_false; + xlator_t *this = NULL; + + this = THIS; + GF_ASSERT(this); + GF_ASSERT (dict); + GF_ASSERT (type); + + snprintf (name_buf, sizeof(name_buf), "hold_%s_locks", type); + hold_locks = dict_get_str_boolean (dict, name_buf, default_value); + + if (hold_locks == _gf_false) { + /* Not holding locks for this particular entity */ + ret = 0; + goto out; + } + + /* Looking for volcount or snapcount in the dict */ + snprintf (name_buf, sizeof(name_buf), "%scount", type); + ret = dict_get_int32 (dict, name_buf, &count); + if (ret) { + /* count is not present. Only one * + * element name needs to be locked */ + snprintf (name_buf, sizeof(name_buf), "%sname", + type); + ret = dict_get_str (dict, name_buf, &name); + if (ret) { + gf_log (this->name, GF_LOG_ERROR, + "Unable to fetch %sname", type); + goto out; + } + + ret = glusterd_mgmt_v3_lock (name, uuid, type); + if (ret) { + gf_log (this->name, GF_LOG_ERROR, + "Failed to acquire lock for %s %s " + "on behalf of %s.", type, name, + uuid_utoa(uuid)); + goto out; + } + } else { + /* Locking one element name after another */ + ret = glusterd_acquire_multiple_locks_per_entity (dict, + uuid, + count, + type); + if (ret) { + gf_log (this->name, GF_LOG_ERROR, + "Failed to acquire all %s locks", type); + goto out; + } + } + + ret = 0; +out: + gf_log (this->name, GF_LOG_TRACE, "Returning %d", ret); + return ret; +} + +/* Try to release locks of multiple entities like * + * volume, snaps etc. */ +int32_t +glusterd_multiple_mgmt_v3_unlock (dict_t *dict, uuid_t uuid) +{ + int32_t i = -1; + int32_t ret = -1; + int32_t op_ret = 0; + xlator_t *this = NULL; + + this = THIS; + GF_ASSERT(this); + + if (!dict) { + gf_log (this->name, GF_LOG_ERROR, "dict is null."); + ret = -1; + goto out; + } + + for (i = 0; valid_types[i].type; i++) { + ret = glusterd_mgmt_v3_unlock_entity + (dict, uuid, + valid_types[i].type, + valid_types[i].default_value); + if (ret) { + gf_log (this->name, GF_LOG_ERROR, + "Unable to unlock all %s", + valid_types[i].type); + op_ret = ret; + } + } + + ret = op_ret; +out: + gf_log (this->name, GF_LOG_DEBUG, "Returning %d", ret); + return ret; +} + +/* Try to acquire locks on multiple entities like * + * volume, snaps etc. */ +int32_t +glusterd_multiple_mgmt_v3_lock (dict_t *dict, uuid_t uuid) +{ + int32_t i = -1; + int32_t ret = -1; + int32_t locked_count = 0; + xlator_t *this = NULL; + + this = THIS; + GF_ASSERT(this); + + if (!dict) { + gf_log (this->name, GF_LOG_ERROR, "dict is null."); + ret = -1; + goto out; + } + + /* Locking one entity after other */ + for (i = 0; valid_types[i].type; i++) { + ret = glusterd_mgmt_v3_lock_entity + (dict, uuid, + valid_types[i].type, + valid_types[i].default_value); + if (ret) { + gf_log (this->name, GF_LOG_ERROR, + "Unable to lock all %s", + valid_types[i].type); + break; + } + locked_count++; + } + + if (locked_count == GF_MAX_LOCKING_ENTITIES) { + /* If all locking ops went successfuly, return as success */ + ret = 0; + goto out; + } + + /* If we failed to lock one entity, unlock others and return failure */ + for (i = 0; i < locked_count; i++) { + ret = glusterd_mgmt_v3_unlock_entity + (dict, uuid, + valid_types[i].type, + valid_types[i].default_value); + if (ret) { + gf_log (this->name, GF_LOG_ERROR, + "Unable to unlock all %s", + valid_types[i].type); + } + } + ret = -1; +out: + gf_log (this->name, GF_LOG_DEBUG, "Returning %d", ret); + return ret; +} + +int32_t +glusterd_mgmt_v3_lock (const char *name, uuid_t uuid, char *type) +{ + char key[PATH_MAX] = ""; + int32_t ret = -1; + mgmt_v3_lock_obj *lock_obj = NULL; + gf_boolean_t is_valid = _gf_true; + uuid_t owner = {0}; + xlator_t *this = NULL; + + GF_ASSERT(THIS); + this = THIS; + + if (!name || !type) { + gf_log (this->name, GF_LOG_ERROR, "name or type is null."); + ret = -1; + goto out; + } + + is_valid = glusterd_mgmt_v3_is_type_valid (type); + if (is_valid != _gf_true) { + gf_log (this->name, GF_LOG_ERROR, + "Invalid entity. Cannot perform locking " + "operation on %s types", type); + ret = -1; + goto out; + } + + ret = snprintf (key, sizeof(key), "%s_%s", name, type); + if (ret != strlen(name) + 1 + strlen(type)) { + ret = -1; + gf_log (this->name, GF_LOG_ERROR, "Unable to create key"); + goto out; + } + + gf_log (this->name, GF_LOG_DEBUG, + "Trying to acquire lock of %s %s for %s as %s", + type, name, uuid_utoa (uuid), key); + + ret = glusterd_get_mgmt_v3_lock_owner (key, &owner); + if (ret) { + gf_log (this->name, GF_LOG_DEBUG, + "Unable to get mgmt_v3 lock owner"); + goto out; + } + + /* If the lock has already been held for the given volume + * we fail */ + if (!uuid_is_null (owner)) { + gf_log (this->name, GF_LOG_ERROR, "Lock for %s held by %s", + name, uuid_utoa (owner)); + ret = -1; + goto out; + } + + lock_obj = GF_CALLOC (1, sizeof(mgmt_v3_lock_obj), + gf_common_mt_mgmt_v3_lock_obj_t); + if (!lock_obj) { + ret = -1; + goto out; + } + + uuid_copy (lock_obj->lock_owner, uuid); + + ret = dict_set_bin (mgmt_v3_lock, key, lock_obj, + sizeof(*lock_obj)); + if (ret) { + gf_log (this->name, GF_LOG_ERROR, + "Unable to set lock owner in mgmt_v3 lock"); + if (lock_obj) + GF_FREE (lock_obj); + goto out; + } + + gf_log (this->name, GF_LOG_DEBUG, + "Lock for %s %s successfully held by %s", + type, name, uuid_utoa (uuid)); + + ret = 0; +out: + gf_log (this->name, GF_LOG_TRACE, "Returning %d", ret); + return ret; +} + +int32_t +glusterd_mgmt_v3_unlock (const char *name, uuid_t uuid, char *type) +{ + char key[PATH_MAX] = ""; + int32_t ret = -1; + gf_boolean_t is_valid = _gf_true; + uuid_t owner = {0}; + xlator_t *this = NULL; + + GF_ASSERT(THIS); + this = THIS; + + if (!name || !type) { + gf_log (this->name, GF_LOG_ERROR, "name is null."); + ret = -1; + goto out; + } + + is_valid = glusterd_mgmt_v3_is_type_valid (type); + if (is_valid != _gf_true) { + gf_log (this->name, GF_LOG_ERROR, + "Invalid entity. Cannot perform unlocking " + "operation on %s types", type); + ret = -1; + goto out; + } + + ret = snprintf (key, sizeof(key), "%s_%s", + name, type); + if (ret != strlen(name) + 1 + strlen(type)) { + gf_log (this->name, GF_LOG_ERROR, "Unable to create key"); + ret = -1; + goto out; + } + + gf_log (this->name, GF_LOG_DEBUG, + "Trying to release lock of %s %s for %s as %s", + type, name, uuid_utoa (uuid), key); + + ret = glusterd_get_mgmt_v3_lock_owner (key, &owner); + if (ret) { + gf_log (this->name, GF_LOG_DEBUG, + "Unable to get mgmt_v3 lock owner"); + goto out; + } + + if (uuid_is_null (owner)) { + gf_log (this->name, GF_LOG_ERROR, + "Lock for %s %s not held", type, name); + ret = -1; + goto out; + } + + ret = uuid_compare (uuid, owner); + if (ret) { + + gf_log (this->name, GF_LOG_ERROR, "Lock owner mismatch. " + "Lock for %s %s held by %s", + type, name, uuid_utoa (owner)); + goto out; + } + + /* Removing the mgmt_v3 lock from the global list */ + dict_del (mgmt_v3_lock, key); + + gf_log (this->name, GF_LOG_DEBUG, + "Lock for %s %s successfully released", + type, name); + + ret = 0; +out: + gf_log (this->name, GF_LOG_TRACE, "Returning %d", ret); + return ret; +} |