From: Fan Yong Date: Sat, 3 May 2014 02:39:24 +0000 (+0800) Subject: LU-4976 osp: add comments for osp_trans.c functions X-Git-Tag: 2.6.0-RC1~98 X-Git-Url: https://git.whamcloud.com/?p=fs%2Flustre-release.git;a=commitdiff_plain;h=a0da0ad1438f694dcff9ee9826d388927ea19d4e LU-4976 osp: add comments for osp_trans.c functions 1) Rename some structures and functions names to avoid misguiding others, including: 1.1) osp_async_update_interpterer_t => osp_async_request_interpreter_t 1.2) osp_insert_async_update => osp_insert_async_request 1.3) osp_unplug_async_update => osp_unplug_async_request 1.4) osp_async_update_item => osp_async_request 1.5) osp_async_update_item_init => osp_async_request_init 1.6) osp_async_update_item_fini => osp_async_request_fini 1.7) osp_insert_async_update => osp_insert_async_request 2) Add introductory comment block for the osp_trans.c file. And add function comment blocks to all functions in the osp_trans.c file. 3) Typo fixing and code cleanup. Signed-off-by: Fan Yong Change-Id: I3dc4e9d6613baa035d228f2254306b6a71b2d48c Reviewed-on: http://review.whamcloud.com/10361 Reviewed-by: Richard Henwood Tested-by: Jenkins Tested-by: Maloo Reviewed-by: John L. Hammond Reviewed-by: Oleg Drokin --- diff --git a/lustre/osp/osp_internal.h b/lustre/osp/osp_internal.h index 2f08aaa..6f12c20 100644 --- a/lustre/osp/osp_internal.h +++ b/lustre/osp/osp_internal.h @@ -494,27 +494,24 @@ static inline int osp_is_fid_client(struct osp_device *osp) return imp->imp_connect_data.ocd_connect_flags & OBD_CONNECT_FID; } -typedef int (*osp_async_update_interpterer_t)(const struct lu_env *env, - struct object_update_reply *reply, - struct ptlrpc_request *req, - struct osp_object *obj, - void *data, int index, int rc); +typedef int (*osp_async_request_interpreter_t)(const struct lu_env *env, + struct object_update_reply *rep, + struct ptlrpc_request *req, + struct osp_object *obj, + void *data, int index, int rc); /* osp_dev.c */ void osp_update_last_id(struct osp_device *d, obd_id objid); extern struct llog_operations osp_mds_ost_orig_logops; /* osp_trans.c */ -struct dt_update_request * -osp_find_or_create_async_update_request(struct osp_device *osp); -int osp_insert_async_update(const struct lu_env *env, - struct dt_update_request *update, int op, - struct osp_object *obj, int count, - int *lens, const char **bufs, void *data, - osp_async_update_interpterer_t interpterer); -int osp_unplug_async_update(const struct lu_env *env, - struct osp_device *osp, - struct dt_update_request *update); +int osp_insert_async_request(const struct lu_env *env, + int op, struct osp_object *obj, int count, + int *lens, const char **bufs, void *data, + osp_async_request_interpreter_t interpterer); +int osp_unplug_async_request(const struct lu_env *env, + struct osp_device *osp, + struct dt_update_request *update); struct thandle *osp_trans_create(const struct lu_env *env, struct dt_device *d); int osp_trans_start(const struct lu_env *env, struct dt_device *dt, diff --git a/lustre/osp/osp_object.c b/lustre/osp/osp_object.c index efd2a3d..690e1ce 100644 --- a/lustre/osp/osp_object.c +++ b/lustre/osp/osp_object.c @@ -281,7 +281,6 @@ static int osp_declare_attr_get(const struct lu_env *env, struct dt_object *dt, { struct osp_object *obj = dt2osp_obj(dt); struct osp_device *osp = lu2osp_dev(dt->do_lu.lo_dev); - struct dt_update_request *update; int rc = 0; if (obj->opo_ooa == NULL) { @@ -291,14 +290,9 @@ static int osp_declare_attr_get(const struct lu_env *env, struct dt_object *dt, } mutex_lock(&osp->opd_async_requests_mutex); - update = osp_find_or_create_async_update_request(osp); - if (IS_ERR(update)) - rc = PTR_ERR(update); - else - rc = osp_insert_async_update(env, update, OUT_ATTR_GET, obj, 0, - NULL, NULL, - &obj->opo_ooa->ooa_attr, - osp_attr_get_interpterer); + rc = osp_insert_async_request(env, OUT_ATTR_GET, obj, 0, NULL, NULL, + &obj->opo_ooa->ooa_attr, + osp_attr_get_interpterer); mutex_unlock(&osp->opd_async_requests_mutex); return rc; @@ -550,7 +544,6 @@ static int osp_declare_xattr_get(const struct lu_env *env, struct dt_object *dt, { struct osp_object *obj = dt2osp_obj(dt); struct osp_device *osp = lu2osp_dev(dt->do_lu.lo_dev); - struct dt_update_request *update; struct osp_xattr_entry *oxe; int namelen = strlen(name); int rc = 0; @@ -573,33 +566,28 @@ static int osp_declare_xattr_get(const struct lu_env *env, struct dt_object *dt, return -ENOMEM; mutex_lock(&osp->opd_async_requests_mutex); - update = osp_find_or_create_async_update_request(osp); - if (IS_ERR(update)) { - rc = PTR_ERR(update); + rc = osp_insert_async_request(env, OUT_XATTR_GET, obj, 1, + &namelen, &name, oxe, + osp_xattr_get_interpterer); + if (rc != 0) { mutex_unlock(&osp->opd_async_requests_mutex); osp_oac_xattr_put(oxe); } else { - rc = osp_insert_async_update(env, update, OUT_XATTR_GET, obj, - 1, &namelen, &name, oxe, - osp_xattr_get_interpterer); - if (rc != 0) { + struct dt_update_request *update; + + /* XXX: Currently, we trigger the batched async OUT + * RPC via dt_declare_xattr_get(). It is not + * perfect solution, but works well now. + * + * We will improve it in the future. */ + update = osp->opd_async_requests; + if (update != NULL && update->dur_req != NULL && + update->dur_req->ourq_count > 0) { + osp->opd_async_requests = NULL; mutex_unlock(&osp->opd_async_requests_mutex); - osp_oac_xattr_put(oxe); + rc = osp_unplug_async_request(env, osp, update); } else { - /* XXX: Currently, we trigger the batched async OUT - * RPC via dt_declare_xattr_get(). It is not - * perfect solution, but works well now. - * - * We will improve it in the future. */ - update = osp->opd_async_requests; - if (update != NULL && update->dur_req != NULL && - update->dur_req->ourq_count > 0) { - osp->opd_async_requests = NULL; - mutex_unlock(&osp->opd_async_requests_mutex); - rc = osp_unplug_async_update(env, osp, update); - } else { - mutex_unlock(&osp->opd_async_requests_mutex); - } + mutex_unlock(&osp->opd_async_requests_mutex); } } diff --git a/lustre/osp/osp_trans.c b/lustre/osp/osp_trans.c index 8e77ecf..39a42bc 100644 --- a/lustre/osp/osp_trans.c +++ b/lustre/osp/osp_trans.c @@ -20,11 +20,39 @@ * GPL HEADER END */ /* - * Copyright (c) 2013, Intel Corporation. + * Copyright (c) 2014, Intel Corporation. */ /* * lustre/osp/osp_trans.c * + * + * 1. OSP (Object Storage Proxy) transaction methods + * + * Implement OSP layer transaction related interfaces for the dt_device API + * dt_device_operations. + * + * + * 2. Handle asynchronous idempotent operations + * + * The OSP uses OUT (Object Unified Target) RPC to talk with other server + * (MDT or OST) for kinds of operations, such as create, unlink, insert, + * delete, lookup, set_(x)attr, get_(x)attr, and etc. To reduce the number + * of RPCs, we allow multiple operations to be packaged together in single + * OUT RPC. + * + * For the asynchronous idempotent operations, such as get_(x)attr, related + * RPCs will be inserted into a osp_device based shared asynchronous request + * queue - osp_device::opd_async_requests. When the queue is full, all the + * requests in the queue will be packaged into a single OUT RPC and given to + * the ptlrpcd daemon (for sending), then the queue is purged and other new + * requests can be inserted into it. + * + * When the asynchronous idempotent operation inserts the request into the + * shared queue, it will register an interpreter. When the packaged OUT RPC + * is replied (or failed to be sent out), all the registered interpreters + * will be called one by one to handle each own result. + * + * * Author: Di Wang * Author: Fan, Yong */ @@ -38,41 +66,78 @@ struct osp_async_update_args { bool oaua_flow_control; }; -struct osp_async_update_item { - struct list_head oaui_list; - struct osp_object *oaui_obj; - void *oaui_data; - osp_async_update_interpterer_t oaui_interpterer; +struct osp_async_request { + /* list in the dt_update_request::dur_cb_items */ + struct list_head oar_list; + + /* The target of the async update request. */ + struct osp_object *oar_obj; + + /* The data used by oar_interpreter. */ + void *oar_data; + + /* The interpreter function called after the async request handled. */ + osp_async_request_interpreter_t oar_interpreter; }; -static struct osp_async_update_item * -osp_async_update_item_init(struct osp_object *obj, void *data, - osp_async_update_interpterer_t interpterer) +/** + * Allocate an asynchronous request and initialize it with the given parameters. + * + * \param[in] obj pointer to the operation target + * \param[in] data pointer to the data used by the interpreter + * \param[in] interpreter pointer to the interpreter function + * + * \retval pointer to the asychronous request + * \retval NULL if the allocation failed + */ +static struct osp_async_request * +osp_async_request_init(struct osp_object *obj, void *data, + osp_async_request_interpreter_t interpreter) { - struct osp_async_update_item *oaui; + struct osp_async_request *oar; - OBD_ALLOC_PTR(oaui); - if (oaui == NULL) + OBD_ALLOC_PTR(oar); + if (oar == NULL) return NULL; lu_object_get(osp2lu_obj(obj)); - INIT_LIST_HEAD(&oaui->oaui_list); - oaui->oaui_obj = obj; - oaui->oaui_data = data; - oaui->oaui_interpterer = interpterer; + INIT_LIST_HEAD(&oar->oar_list); + oar->oar_obj = obj; + oar->oar_data = data; + oar->oar_interpreter = interpreter; - return oaui; + return oar; } -static void osp_async_update_item_fini(const struct lu_env *env, - struct osp_async_update_item *oaui) +/** + * Destroy the asychronous request. + * + * \param[in] env pointer to the thread context + * \param[in] oar pointer to asychronous request + */ +static void osp_async_request_fini(const struct lu_env *env, + struct osp_async_request *oar) { - LASSERT(list_empty(&oaui->oaui_list)); + LASSERT(list_empty(&oar->oar_list)); - lu_object_put(env, osp2lu_obj(oaui->oaui_obj)); - OBD_FREE_PTR(oaui); + lu_object_put(env, osp2lu_obj(oar->oar_obj)); + OBD_FREE_PTR(oar); } +/** + * Interpret the packaged OUT RPC results. + * + * For every packaged sub-request, call its registered interpreter function. + * Then destroy the sub-request. + * + * \param[in] env pointer to the thread context + * \param[in] req pointer to the RPC + * \param[in] arg pointer to data used by the interpreter + * \param[in] rc the RPC return value + * + * \retval 0 for success + * \retval negative error number on failure + */ static int osp_async_update_interpret(const struct lu_env *env, struct ptlrpc_request *req, void *arg, int rc) @@ -80,8 +145,8 @@ static int osp_async_update_interpret(const struct lu_env *env, struct object_update_reply *reply = NULL; struct osp_async_update_args *oaua = arg; struct dt_update_request *dt_update = oaua->oaua_update; - struct osp_async_update_item *oaui; - struct osp_async_update_item *next; + struct osp_async_request *oar; + struct osp_async_request *next; int count = 0; int index = 0; int rc1 = 0; @@ -90,7 +155,8 @@ static int osp_async_update_interpret(const struct lu_env *env, obd_put_request_slot( &dt2osp_dev(dt_update->dur_dt)->opd_obd->u.cli); - if (rc == 0 || req->rq_repmsg != NULL) { + /* Unpack the results from the reply message. */ + if (req->rq_repmsg != NULL) { reply = req_capsule_server_sized_get(&req->rq_pill, &RMF_OUT_UPDATE_REPLY, OUT_UPDATE_REPLY_SIZE); @@ -102,9 +168,13 @@ static int osp_async_update_interpret(const struct lu_env *env, rc1 = rc; } - list_for_each_entry_safe(oaui, next, &dt_update->dur_cb_items, - oaui_list) { - list_del_init(&oaui->oaui_list); + list_for_each_entry_safe(oar, next, &dt_update->dur_cb_items, + oar_list) { + list_del_init(&oar->oar_list); + + /* The peer may only have handled some requests (indicated + * by the 'count') in the packaged OUT RPC, we can only get + * results for the handled part. */ if (index < count && reply->ourp_lens[index] > 0) { struct object_update_result *result; @@ -119,9 +189,9 @@ static int osp_async_update_interpret(const struct lu_env *env, rc1 = -EINVAL; } - oaui->oaui_interpterer(env, reply, req, oaui->oaui_obj, - oaui->oaui_data, index, rc1); - osp_async_update_item_fini(env, oaui); + oar->oar_interpreter(env, reply, req, oar->oar_obj, + oar->oar_data, index, rc1); + osp_async_request_fini(env, oar); index++; } @@ -130,9 +200,20 @@ static int osp_async_update_interpret(const struct lu_env *env, return 0; } -int osp_unplug_async_update(const struct lu_env *env, - struct osp_device *osp, - struct dt_update_request *update) +/** + * Pack all the requests in the shared asynchronous idempotent request queue + * into a single OUT RPC that will be given to the background ptlrpcd daemon. + * + * \param[in] env pointer to the thread context + * \param[in] osp pointer to the OSP device + * \param[in] update pointer to the shared queue + * + * \retval 0 for success + * \retval negative error number on failure + */ +int osp_unplug_async_request(const struct lu_env *env, + struct osp_device *osp, + struct dt_update_request *update) { struct osp_async_update_args *args; struct ptlrpc_request *req = NULL; @@ -141,15 +222,15 @@ int osp_unplug_async_update(const struct lu_env *env, rc = out_prep_update_req(env, osp->opd_obd->u.cli.cl_import, update->dur_req, &req); if (rc != 0) { - struct osp_async_update_item *oaui; - struct osp_async_update_item *next; - - list_for_each_entry_safe(oaui, next, - &update->dur_cb_items, oaui_list) { - list_del_init(&oaui->oaui_list); - oaui->oaui_interpterer(env, NULL, NULL, oaui->oaui_obj, - oaui->oaui_data, 0, rc); - osp_async_update_item_fini(env, oaui); + struct osp_async_request *oar; + struct osp_async_request *next; + + list_for_each_entry_safe(oar, next, + &update->dur_cb_items, oar_list) { + list_del_init(&oar->oar_list); + oar->oar_interpreter(env, NULL, NULL, oar->oar_obj, + oar->oar_data, 0, rc); + osp_async_request_fini(env, oar); } out_destroy_update_req(update); } else { @@ -164,8 +245,19 @@ int osp_unplug_async_update(const struct lu_env *env, return rc; } -/* with osp::opd_async_requests_mutex held */ -struct dt_update_request * +/** + * Find or create (if NOT exist or purged) the shared asynchronous idempotent + * request queue - osp_device::opd_async_requests. + * + * If the osp_device::opd_async_requests is not NULL, then return it directly; + * otherwise create new dt_update_request and attach it to opd_async_requests. + * + * \param[in] osp pointer to the OSP device + * + * \retval pointer to the shared queue + * \retval negative error number on failure + */ +static struct dt_update_request * osp_find_or_create_async_update_request(struct osp_device *osp) { struct dt_update_request *update = osp->opd_async_requests; @@ -180,30 +272,58 @@ osp_find_or_create_async_update_request(struct osp_device *osp) return update; } -/* with osp::opd_async_requests_mutex held */ -int osp_insert_async_update(const struct lu_env *env, - struct dt_update_request *update, int op, - struct osp_object *obj, int count, - int *lens, const char **bufs, void *data, - osp_async_update_interpterer_t interpterer) +/** + * Insert an asynchronous idempotent request to the shared request queue that + * is attached to the osp_device. + * + * This function generates a new osp_async_request with the given parameters, + * then tries to insert the request into the osp_device-based shared request + * queue. If the queue is full, then triggers the packaged OUT RPC to purge + * the shared queue firstly, and then re-tries. + * + * NOTE: must hold the osp::opd_async_requests_mutex to serialize concurrent + * osp_insert_async_request call from others. + * + * \param[in] env pointer to the thread context + * \param[in] op operation type, see 'enum update_type' + * \param[in] obj pointer to the operation target + * \param[in] count array size of the subsequent @lens and @bufs + * \param[in] lens buffer length array for the subsequent @bufs + * \param[in] bufs the buffers to compose the request + * \param[in] data pointer to the data used by the interpreter + * \param[in] interpreter pointer to the interpreter function + * + * \retval 0 for success + * \retval negative error number on failure + */ +int osp_insert_async_request(const struct lu_env *env, + int op, struct osp_object *obj, int count, + int *lens, const char **bufs, void *data, + osp_async_request_interpreter_t interpreter) { - struct osp_async_update_item *oaui; + struct osp_async_request *oar; struct osp_device *osp = lu2osp_dev(osp2lu_obj(obj)->lo_dev); + struct dt_update_request *update; int rc = 0; ENTRY; - oaui = osp_async_update_item_init(obj, data, interpterer); - if (oaui == NULL) + oar = osp_async_request_init(obj, data, interpreter); + if (oar == NULL) RETURN(-ENOMEM); + update = osp_find_or_create_async_update_request(osp); + if (IS_ERR(update)) + GOTO(out, rc = PTR_ERR(update)); + again: rc = out_insert_update(env, update, op, lu_object_fid(osp2lu_obj(obj)), count, lens, bufs); + /* The queue is full. */ if (rc == -E2BIG) { osp->opd_async_requests = NULL; mutex_unlock(&osp->opd_async_requests_mutex); - rc = osp_unplug_async_update(env, osp, update); + rc = osp_unplug_async_request(env, osp, update); mutex_lock(&osp->opd_async_requests_mutex); if (rc != 0) GOTO(out, rc); @@ -216,27 +336,49 @@ again: } if (rc == 0) - list_add_tail(&oaui->oaui_list, &update->dur_cb_items); + list_add_tail(&oar->oar_list, &update->dur_cb_items); GOTO(out, rc); out: if (rc != 0) - osp_async_update_item_fini(env, oaui); + osp_async_request_fini(env, oar); return rc; } /** - * If the transaction creation goes to OSP, it means the update - * in this transaction only includes remote UPDATE. It is only - * used by LFSCK right now. - **/ + * The OSP layer dt_device_operations::dt_trans_create() interface + * to create a transaction. + * + * There are two kinds of transactions that will involve OSP: + * + * 1) If the transaction only contains the updates on remote server + * (MDT or OST), such as re-generating the lost OST-object for + * LFSCK, then it is a remote transaction. For remote transaction, + * the upper layer caller (such as the LFSCK engine) will call the + * dt_trans_create() (with the OSP dt_device as the parameter), + * then the call will be directed to the osp_trans_create() that + * creates the transaction handler and returns it to the caller. + * + * 2) If the transcation contains both local and remote updates, + * such as cross MDTs create under DNE mode, then the upper layer + * caller will not trigger osp_trans_create(). Instead, it will + * call dt_trans_create() on other dt_device, such as LOD that + * will generate the transaction handler. Such handler will be + * used by the whole transaction in subsequent sub-operations. + * + * \param[in] env pointer to the thread context + * \param[in] d pointer to the OSP dt_device + * + * \retval pointer to the transaction handler + * \retval negative error number on failure + */ struct thandle *osp_trans_create(const struct lu_env *env, struct dt_device *d) { - struct thandle *th = NULL; - struct thandle_update *tu = NULL; - int rc = 0; + struct thandle *th = NULL; + struct thandle_update *tu = NULL; + int rc = 0; OBD_ALLOC_PTR(th); if (unlikely(th == NULL)) @@ -267,17 +409,33 @@ out: return th; } +/** + * Trigger the request for remote updates. + * + * If the transaction is a remote transaction, then related remote updates + * will be sent asynchronously; otherwise, the cross MDTs transaction will + * be synchronized. + * + * Please refer to osp_trans_create() for transaction type. + * + * \param[in] env pointer to the thread context + * \param[in] osp pointer to the OSP device + * \param[in] dt_update pointer to the dt_update_request + * \param[in] th pointer to the transaction handler + * \param[in] flow_control whether need to control the flow + * + * \retval 0 for success + * \retval negative error number on failure + */ static int osp_trans_trigger(const struct lu_env *env, struct osp_device *osp, struct dt_update_request *dt_update, struct thandle *th, bool flow_control) { struct thandle_update *tu = th->th_update; - int rc = 0; + int rc = 0; LASSERT(tu != NULL); - /* If the transaction only includes remote update, it should - * still be asynchronous */ if (is_only_remote_trans(th)) { struct osp_async_update_args *args; struct ptlrpc_request *req; @@ -296,8 +454,6 @@ static int osp_trans_trigger(const struct lu_env *env, struct osp_device *osp, out_destroy_update_req(dt_update); } } else { - /* Before we support async update, the cross MDT transaction - * has to been synchronized */ th->th_sync = 1; rc = out_remote_sync(env, osp->opd_obd->u.cli.cl_import, dt_update, NULL); @@ -306,12 +462,39 @@ static int osp_trans_trigger(const struct lu_env *env, struct osp_device *osp, return rc; } +/** + * The OSP layer dt_device_operations::dt_trans_start() interface + * to start the transaction. + * + * If the transaction is a remote transaction, then related remote + * updates will be triggered in the osp_trans_stop(); otherwise the + * transaction contains both local and remote update(s), then when + * the OUT RPC will be triggered depends on the operation, and is + * indicated by the dt_device::tu_sent_after_local_trans, for example: + * + * 1) If it is remote create, it will send the remote req after local + * transaction. i.e. create the object locally first, then insert the + * remote name entry. + * + * 2) If it is remote unlink, it will send the remote req before the + * local transaction, i.e. delete the name entry remotely first, then + * destroy the local object. + * + * Please refer to osp_trans_create() for transaction type. + * + * \param[in] env pointer to the thread context + * \param[in] dt pointer to the OSP dt_device + * \param[in] th pointer to the transaction handler + * + * \retval 0 for success + * \retval negative error number on failure + */ int osp_trans_start(const struct lu_env *env, struct dt_device *dt, struct thandle *th) { - struct thandle_update *tu = th->th_update; - struct dt_update_request *dt_update; - int rc = 0; + struct thandle_update *tu = th->th_update; + struct dt_update_request *dt_update; + int rc = 0; if (tu == NULL) return rc; @@ -321,19 +504,6 @@ int osp_trans_start(const struct lu_env *env, struct dt_device *dt, if (dt_update == NULL) return rc; - /* Note: some updates needs to send before local transaction, - * some needs to send after local transaction. - * - * If the transaction only includes remote updates, it will - * send updates to remote MDT in osp_trans_stop. - * - * If it is remote create, it will send the remote req after - * local transaction. i.e. create the object locally first, - * then insert the name entry. - * - * If it is remote unlink, it will send the remote req before - * the local transaction, i.e. delete the name entry remote - * first, then destroy the local object. */ if (!is_only_remote_trans(th) && !tu->tu_sent_after_local_trans) rc = osp_trans_trigger(env, dt2osp_dev(dt), dt_update, th, false); @@ -341,15 +511,36 @@ int osp_trans_start(const struct lu_env *env, struct dt_device *dt, return rc; } +/** + * The OSP layer dt_device_operations::dt_trans_stop() interface + * to stop the transaction. + * + * If the transaction is a remote transaction, or the update handler + * is marked as 'tu_sent_after_local_trans', then related remote + * updates will be triggered here via osp_trans_trigger(). + * + * For synchronous mode update or any failed update, the request + * will be destroyed explicitly when the osp_trans_stop(). + * + * Please refer to osp_trans_create() for transaction type. + * + * \param[in] env pointer to the thread context + * \param[in] dt pointer to the OSP dt_device + * \param[in] th pointer to the transaction handler + * + * \retval 0 for success + * \retval negative error number on failure + */ int osp_trans_stop(const struct lu_env *env, struct dt_device *dt, struct thandle *th) { struct thandle_update *tu = th->th_update; struct dt_update_request *dt_update; - int rc = 0; + int rc = 0; LASSERT(tu != NULL); - LASSERT(tu != LP_POISON); + LASSERT(tu != LP_POISON); + /* Check whether there are updates related with this OSP */ dt_update = out_find_update(tu, dt); if (dt_update == NULL) {