/* * GPL HEADER START * * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 only, * as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License version 2 for more details (a copy is included * in the LICENSE file that accompanied this code). * * You should have received a copy of the GNU General Public License * version 2 along with this program; If not, see * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf * * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, * CA 95054 USA or visit www.sun.com if you need additional information or * have any questions. * * GPL HEADER END */ /* * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved. * Use is subject to license terms. * * Copyright (c) 2012, 2013, Intel Corporation. */ /* * This file is part of Lustre, http://www.lustre.org/ * Lustre is a trademark of Sun Microsystems, Inc. */ /* * This file is part of Lustre, http://www.lustre.org/ * Lustre is a trademark of Sun Microsystems, Inc. * * Internal interfaces of LOV layer. * * Author: Nikita Danilov * Author: Jinshan Xiong */ #ifndef LOV_CL_INTERNAL_H #define LOV_CL_INTERNAL_H #ifdef __KERNEL__ # include #else # include #endif #include #include #include "lov_internal.h" /** \defgroup lov lov * Logical object volume layer. This layer implements data striping (raid0). * * At the lov layer top-entity (object, page, lock, io) is connected to one or * more sub-entities: top-object, representing a file is connected to a set of * sub-objects, each representing a stripe, file-level top-lock is connected * to a set of per-stripe sub-locks, top-page is connected to a (single) * sub-page, and a top-level IO is connected to a set of (potentially * concurrent) sub-IO's. * * Sub-object, sub-page, and sub-io have well-defined top-object and top-page * respectively, while a single sub-lock can be part of multiple top-locks. * * Reference counting models are different for different types of entities: * * - top-object keeps a reference to its sub-objects, and destroys them * when it is destroyed. * * - top-page keeps a reference to its sub-page, and destroys it when it * is destroyed. * * - sub-lock keep a reference to its top-locks. Top-lock keeps a * reference (and a hold, see cl_lock_hold()) on its sub-locks when it * actively using them (that is, in cl_lock_state::CLS_QUEUING, * cl_lock_state::CLS_ENQUEUED, cl_lock_state::CLS_HELD states). When * moving into cl_lock_state::CLS_CACHED state, top-lock releases a * hold. From this moment top-lock has only a 'weak' reference to its * sub-locks. This reference is protected by top-lock * cl_lock::cll_guard, and will be automatically cleared by the sub-lock * when the latter is destroyed. When a sub-lock is canceled, a * reference to it is removed from the top-lock array, and top-lock is * moved into CLS_NEW state. It is guaranteed that all sub-locks exist * while their top-lock is in CLS_HELD or CLS_CACHED states. * * - IO's are not reference counted. * * To implement a connection between top and sub entities, lov layer is split * into two pieces: lov ("upper half"), and lovsub ("bottom half"), both * implementing full set of cl-interfaces. For example, top-object has vvp and * lov layers, and it's sub-object has lovsub and osc layers. lovsub layer is * used to track child-parent relationship. * * @{ */ struct lovsub_device; struct lovsub_object; struct lovsub_lock; enum lov_device_flags { LOV_DEV_INITIALIZED = 1 << 0 }; /* * Upper half. */ /** * Resources that are used in memory-cleaning path, and whose allocation * cannot fail even when memory is tight. They are preallocated in sufficient * quantities in lov_device::ld_emerg[], and access to them is serialized * lov_device::ld_mutex. */ struct lov_device_emerg { /** * Page list used to submit IO when memory is in pressure. */ struct cl_page_list emrg_page_list; /** * sub-io's shared by all threads accessing this device when memory is * too low to allocate sub-io's dynamically. */ struct cl_io emrg_subio; /** * Environments used by sub-io's in * lov_device_emerg::emrg_subio. */ struct lu_env *emrg_env; /** * Refchecks for lov_device_emerg::emrg_env. * * \see cl_env_get() */ int emrg_refcheck; }; struct lov_device { /* * XXX Locking of lov-private data is missing. */ struct cl_device ld_cl; struct lov_obd *ld_lov; /** size of lov_device::ld_target[] array */ __u32 ld_target_nr; struct lovsub_device **ld_target; __u32 ld_flags; /** Emergency resources used in memory-cleansing paths. */ struct lov_device_emerg **ld_emrg; /** * Serializes access to lov_device::ld_emrg in low-memory * conditions. */ struct mutex ld_mutex; }; /** * Layout type. */ enum lov_layout_type { LLT_EMPTY, /** empty file without body (mknod + truncate) */ LLT_RAID0, /** striped file */ LLT_RELEASED, /** file with no objects (data in HSM) */ LLT_NR }; static inline char *llt2str(enum lov_layout_type llt) { switch (llt) { case LLT_EMPTY: return "EMPTY"; case LLT_RAID0: return "RAID0"; case LLT_RELEASED: return "RELEASED"; case LLT_NR: LBUG(); } LBUG(); return ""; } /** * lov-specific file state. * * lov object has particular layout type, determining how top-object is built * on top of sub-objects. Layout type can change dynamically. When this * happens, lov_object::lo_type_guard semaphore is taken in exclusive mode, * all state pertaining to the old layout type is destroyed, and new state is * constructed. All object methods take said semaphore in the shared mode, * providing serialization against transition between layout types. * * To avoid multiple `if' or `switch' statements, selecting behavior for the * current layout type, object methods perform double-dispatch, invoking * function corresponding to the current layout type. */ struct lov_object { struct cl_object lo_cl; /** * Serializes object operations with transitions between layout types. * * This semaphore is taken in shared mode by all object methods, and * is taken in exclusive mode when object type is changed. * * \see lov_object::lo_type */ struct rw_semaphore lo_type_guard; /** * Type of an object. Protected by lov_object::lo_type_guard. */ enum lov_layout_type lo_type; /** * True if layout is invalid. This bit is cleared when layout lock * is lost. */ bool lo_layout_invalid; /** * How many IOs are on going on this object. Layout can be changed * only if there is no active IO. */ cfs_atomic_t lo_active_ios; /** * Waitq - wait for no one else is using lo_lsm */ wait_queue_head_t lo_waitq; /** * Layout metadata. NULL if empty layout. */ struct lov_stripe_md *lo_lsm; union lov_layout_state { struct lov_layout_raid0 { unsigned lo_nr; /** * When this is true, lov_object::lo_attr contains * valid up to date attributes for a top-level * object. This field is reset to 0 when attributes of * any sub-object change. */ int lo_attr_valid; /** * Array of sub-objects. Allocated when top-object is * created (lov_init_raid0()). * * Top-object is a strict master of its sub-objects: * it is created before them, and outlives its * children (this later is necessary so that basic * functions like cl_object_top() always * work). Top-object keeps a reference on every * sub-object. * * When top-object is destroyed (lov_delete_raid0()) * it releases its reference to a sub-object and waits * until the latter is finally destroyed. */ struct lovsub_object **lo_sub; /** * protect lo_sub */ spinlock_t lo_sub_lock; /** * Cached object attribute, built from sub-object * attributes. */ struct cl_attr lo_attr; } raid0; struct lov_layout_state_empty { } empty; struct lov_layout_state_released { } released; } u; /** * Thread that acquired lov_object::lo_type_guard in an exclusive * mode. */ struct task_struct *lo_owner; }; /** * Flags that top-lock can set on each of its sub-locks. */ enum lov_sub_flags { /** Top-lock acquired a hold (cl_lock_hold()) on a sub-lock. */ LSF_HELD = 1 << 0 }; /** * State lov_lock keeps for each sub-lock. */ struct lov_lock_sub { /** sub-lock itself */ struct lovsub_lock *sub_lock; /** An array of per-sub-lock flags, taken from enum lov_sub_flags */ unsigned sub_flags; int sub_stripe; struct cl_lock_descr sub_descr; struct cl_lock_descr sub_got; }; /** * lov-specific lock state. */ struct lov_lock { struct cl_lock_slice lls_cl; /** Number of sub-locks in this lock */ int lls_nr; /** * Number of existing sub-locks. */ unsigned lls_nr_filled; /** * Set when sub-lock was canceled, while top-lock was being * used, or unused. */ unsigned int lls_cancel_race:1, lls_ever_canceled:1; /** * An array of sub-locks * * There are two issues with managing sub-locks: * * - sub-locks are concurrently canceled, and * * - sub-locks are shared with other top-locks. * * To manage cancellation, top-lock acquires a hold on a sublock * (lov_sublock_adopt()) when the latter is inserted into * lov_lock::lls_sub[]. This hold is released (lov_sublock_release()) * when top-lock is going into CLS_CACHED state or destroyed. Hold * prevents sub-lock from cancellation. * * Sub-lock sharing means, among other things, that top-lock that is * in the process of creation (i.e., not yet inserted into lock list) * is already accessible to other threads once at least one of its * sub-locks is created, see lov_lock_sub_init(). * * Sub-lock can be in one of the following states: * * - doesn't exist, lov_lock::lls_sub[]::sub_lock == NULL. Such * sub-lock was either never created (top-lock is in CLS_NEW * state), or it was created, then canceled, then destroyed * (lov_lock_unlink() cleared sub-lock pointer in the top-lock). * * - sub-lock exists and is on * hold. (lov_lock::lls_sub[]::sub_flags & LSF_HELD). This is a * normal state of a sub-lock in CLS_HELD and CLS_CACHED states * of a top-lock. * * - sub-lock exists, but is not held by the top-lock. This * happens after top-lock released a hold on sub-locks before * going into cache (lov_lock_unuse()). * * \todo To support wide-striping, array has to be replaced with a set * of queues to avoid scanning. */ struct lov_lock_sub *lls_sub; /** * Original description with which lock was enqueued. */ struct cl_lock_descr lls_orig; }; struct lov_page { struct cl_page_slice lps_cl; int lps_invalid; }; /* * Bottom half. */ struct lovsub_device { struct cl_device acid_cl; struct lov_device *acid_super; int acid_idx; struct cl_device *acid_next; }; struct lovsub_object { struct cl_object_header lso_header; struct cl_object lso_cl; struct lov_object *lso_super; int lso_index; }; /** * A link between a top-lock and a sub-lock. Separate data-structure is * necessary, because top-locks and sub-locks are in M:N relationship. * * \todo This can be optimized for a (by far) most frequent case of a single * top-lock per sub-lock. */ struct lov_lock_link { struct lov_lock *lll_super; /** An index within parent lock. */ int lll_idx; /** * A linkage into per sub-lock list of all corresponding top-locks, * hanging off lovsub_lock::lss_parents. */ cfs_list_t lll_list; }; /** * Lock state at lovsub layer. */ struct lovsub_lock { struct cl_lock_slice lss_cl; /** * List of top-locks that have given sub-lock as their part. Protected * by cl_lock::cll_guard mutex. */ cfs_list_t lss_parents; /** * Top-lock that initiated current operation on this sub-lock. This is * only set during top-to-bottom lock operations like enqueue, and is * used to optimize state change notification. Protected by * cl_lock::cll_guard mutex. * * \see lovsub_lock_state_one(). */ struct cl_lock *lss_active; }; /** * Describe the environment settings for sublocks. */ struct lov_sublock_env { const struct lu_env *lse_env; struct cl_io *lse_io; struct lov_io_sub *lse_sub; }; struct lovsub_page { struct cl_page_slice lsb_cl; }; struct lov_thread_info { struct cl_object_conf lti_stripe_conf; struct lu_fid lti_fid; struct cl_lock_descr lti_ldescr; struct ost_lvb lti_lvb; struct cl_2queue lti_cl2q; struct cl_lock_closure lti_closure; wait_queue_t lti_waiter; }; /** * State that lov_io maintains for every sub-io. */ struct lov_io_sub { int sub_stripe; /** * sub-io for a stripe. Ideally sub-io's can be stopped and resumed * independently, with lov acting as a scheduler to maximize overall * throughput. */ struct cl_io *sub_io; /** * Linkage into a list (hanging off lov_io::lis_active) of all * sub-io's active for the current IO iteration. */ cfs_list_t sub_linkage; /** * true, iff cl_io_init() was successfully executed against * lov_io_sub::sub_io. */ int sub_io_initialized; /** * True, iff lov_io_sub::sub_io and lov_io_sub::sub_env weren't * allocated, but borrowed from a per-device emergency pool. */ int sub_borrowed; /** * environment, in which sub-io executes. */ struct lu_env *sub_env; /** * environment's refcheck. * * \see cl_env_get() */ int sub_refcheck; int sub_refcheck2; int sub_reenter; void *sub_cookie; }; /** * IO state private for LOV. */ struct lov_io { /** super-class */ struct cl_io_slice lis_cl; /** * Pointer to the object slice. This is a duplicate of * lov_io::lis_cl::cis_object. */ struct lov_object *lis_object; /** * Original end-of-io position for this IO, set by the upper layer as * cl_io::u::ci_rw::pos + cl_io::u::ci_rw::count. lov remembers this, * changes pos and count to fit IO into a single stripe and uses saved * value to determine when IO iterations have to stop. * * This is used only for CIT_READ and CIT_WRITE io's. */ loff_t lis_io_endpos; /** * starting position within a file, for the current io loop iteration * (stripe), used by ci_io_loop(). */ obd_off lis_pos; /** * end position with in a file, for the current stripe io. This is * exclusive (i.e., next offset after last byte affected by io). */ obd_off lis_endpos; int lis_mem_frozen; int lis_stripe_count; int lis_active_subios; /** * the index of ls_single_subio in ls_subios array */ int lis_single_subio_index; struct cl_io lis_single_subio; /** * size of ls_subios array, actually the highest stripe # */ int lis_nr_subios; struct lov_io_sub *lis_subs; /** * List of active sub-io's. */ cfs_list_t lis_active; }; struct lov_session { struct lov_io ls_io; struct lov_sublock_env ls_subenv; }; /** * State of transfer for lov. */ struct lov_req { struct cl_req_slice lr_cl; }; /** * State of transfer for lovsub. */ struct lovsub_req { struct cl_req_slice lsrq_cl; }; extern struct lu_device_type lov_device_type; extern struct lu_device_type lovsub_device_type; extern struct lu_context_key lov_key; extern struct lu_context_key lov_session_key; extern struct kmem_cache *lov_lock_kmem; extern struct kmem_cache *lov_object_kmem; extern struct kmem_cache *lov_thread_kmem; extern struct kmem_cache *lov_session_kmem; extern struct kmem_cache *lov_req_kmem; extern struct kmem_cache *lovsub_lock_kmem; extern struct kmem_cache *lovsub_object_kmem; extern struct kmem_cache *lovsub_req_kmem; extern struct kmem_cache *lov_lock_link_kmem; int lov_object_init (const struct lu_env *env, struct lu_object *obj, const struct lu_object_conf *conf); int lovsub_object_init (const struct lu_env *env, struct lu_object *obj, const struct lu_object_conf *conf); int lov_lock_init (const struct lu_env *env, struct cl_object *obj, struct cl_lock *lock, const struct cl_io *io); int lov_io_init (const struct lu_env *env, struct cl_object *obj, struct cl_io *io); int lovsub_lock_init (const struct lu_env *env, struct cl_object *obj, struct cl_lock *lock, const struct cl_io *io); int lov_lock_init_raid0 (const struct lu_env *env, struct cl_object *obj, struct cl_lock *lock, const struct cl_io *io); int lov_lock_init_empty (const struct lu_env *env, struct cl_object *obj, struct cl_lock *lock, const struct cl_io *io); int lov_io_init_raid0 (const struct lu_env *env, struct cl_object *obj, struct cl_io *io); int lov_io_init_empty (const struct lu_env *env, struct cl_object *obj, struct cl_io *io); int lov_io_init_released(const struct lu_env *env, struct cl_object *obj, struct cl_io *io); void lov_lock_unlink (const struct lu_env *env, struct lov_lock_link *link, struct lovsub_lock *sub); struct lov_io_sub *lov_sub_get(const struct lu_env *env, struct lov_io *lio, int stripe); void lov_sub_put (struct lov_io_sub *sub); int lov_sublock_modify (const struct lu_env *env, struct lov_lock *lov, struct lovsub_lock *sublock, const struct cl_lock_descr *d, int idx); int lov_page_init (const struct lu_env *env, struct cl_object *ob, struct cl_page *page, struct page *vmpage); int lovsub_page_init (const struct lu_env *env, struct cl_object *ob, struct cl_page *page, struct page *vmpage); int lov_page_init_empty (const struct lu_env *env, struct cl_object *obj, struct cl_page *page, struct page *vmpage); int lov_page_init_raid0 (const struct lu_env *env, struct cl_object *obj, struct cl_page *page, struct page *vmpage); struct lu_object *lov_object_alloc (const struct lu_env *env, const struct lu_object_header *hdr, struct lu_device *dev); struct lu_object *lovsub_object_alloc(const struct lu_env *env, const struct lu_object_header *hdr, struct lu_device *dev); struct lov_lock_link *lov_lock_link_find(const struct lu_env *env, struct lov_lock *lck, struct lovsub_lock *sub); struct lov_io_sub *lov_page_subio (const struct lu_env *env, struct lov_io *lio, const struct cl_page_slice *slice); void lov_lsm_decref(struct lov_object *lov, struct lov_stripe_md *lsm); struct lov_stripe_md *lov_lsm_addref(struct lov_object *lov); #define lov_foreach_target(lov, var) \ for (var = 0; var < lov_targets_nr(lov); ++var) /***************************************************************************** * * Type conversions. * * Accessors. * */ static inline struct lov_session *lov_env_session(const struct lu_env *env) { struct lov_session *ses; ses = lu_context_key_get(env->le_ses, &lov_session_key); LASSERT(ses != NULL); return ses; } static inline struct lov_io *lov_env_io(const struct lu_env *env) { return &lov_env_session(env)->ls_io; } static inline int lov_is_object(const struct lu_object *obj) { return obj->lo_dev->ld_type == &lov_device_type; } static inline int lovsub_is_object(const struct lu_object *obj) { return obj->lo_dev->ld_type == &lovsub_device_type; } static inline struct lu_device *lov2lu_dev(struct lov_device *lov) { return &lov->ld_cl.cd_lu_dev; } static inline struct lov_device *lu2lov_dev(const struct lu_device *d) { LINVRNT(d->ld_type == &lov_device_type); return container_of0(d, struct lov_device, ld_cl.cd_lu_dev); } static inline struct cl_device *lovsub2cl_dev(struct lovsub_device *lovsub) { return &lovsub->acid_cl; } static inline struct lu_device *lovsub2lu_dev(struct lovsub_device *lovsub) { return &lovsub2cl_dev(lovsub)->cd_lu_dev; } static inline struct lovsub_device *lu2lovsub_dev(const struct lu_device *d) { LINVRNT(d->ld_type == &lovsub_device_type); return container_of0(d, struct lovsub_device, acid_cl.cd_lu_dev); } static inline struct lovsub_device *cl2lovsub_dev(const struct cl_device *d) { LINVRNT(d->cd_lu_dev.ld_type == &lovsub_device_type); return container_of0(d, struct lovsub_device, acid_cl); } static inline struct lu_object *lov2lu(struct lov_object *lov) { return &lov->lo_cl.co_lu; } static inline struct cl_object *lov2cl(struct lov_object *lov) { return &lov->lo_cl; } static inline struct lov_object *lu2lov(const struct lu_object *obj) { LINVRNT(lov_is_object(obj)); return container_of0(obj, struct lov_object, lo_cl.co_lu); } static inline struct lov_object *cl2lov(const struct cl_object *obj) { LINVRNT(lov_is_object(&obj->co_lu)); return container_of0(obj, struct lov_object, lo_cl); } static inline struct lu_object *lovsub2lu(struct lovsub_object *los) { return &los->lso_cl.co_lu; } static inline struct cl_object *lovsub2cl(struct lovsub_object *los) { return &los->lso_cl; } static inline struct lovsub_object *cl2lovsub(const struct cl_object *obj) { LINVRNT(lovsub_is_object(&obj->co_lu)); return container_of0(obj, struct lovsub_object, lso_cl); } static inline struct lovsub_object *lu2lovsub(const struct lu_object *obj) { LINVRNT(lovsub_is_object(obj)); return container_of0(obj, struct lovsub_object, lso_cl.co_lu); } static inline struct lovsub_lock * cl2lovsub_lock(const struct cl_lock_slice *slice) { LINVRNT(lovsub_is_object(&slice->cls_obj->co_lu)); return container_of(slice, struct lovsub_lock, lss_cl); } static inline struct lovsub_lock *cl2sub_lock(const struct cl_lock *lock) { const struct cl_lock_slice *slice; slice = cl_lock_at(lock, &lovsub_device_type); LASSERT(slice != NULL); return cl2lovsub_lock(slice); } static inline struct lov_lock *cl2lov_lock(const struct cl_lock_slice *slice) { LINVRNT(lov_is_object(&slice->cls_obj->co_lu)); return container_of(slice, struct lov_lock, lls_cl); } static inline struct lov_page *cl2lov_page(const struct cl_page_slice *slice) { LINVRNT(lov_is_object(&slice->cpl_obj->co_lu)); return container_of0(slice, struct lov_page, lps_cl); } static inline struct lov_req *cl2lov_req(const struct cl_req_slice *slice) { return container_of0(slice, struct lov_req, lr_cl); } static inline struct lovsub_page * cl2lovsub_page(const struct cl_page_slice *slice) { LINVRNT(lovsub_is_object(&slice->cpl_obj->co_lu)); return container_of0(slice, struct lovsub_page, lsb_cl); } static inline struct lovsub_req *cl2lovsub_req(const struct cl_req_slice *slice) { return container_of0(slice, struct lovsub_req, lsrq_cl); } static inline struct cl_page *lov_sub_page(const struct cl_page_slice *slice) { return slice->cpl_page->cp_child; } static inline struct lov_io *cl2lov_io(const struct lu_env *env, const struct cl_io_slice *ios) { struct lov_io *lio; lio = container_of(ios, struct lov_io, lis_cl); LASSERT(lio == lov_env_io(env)); return lio; } static inline int lov_targets_nr(const struct lov_device *lov) { return lov->ld_lov->desc.ld_tgt_count; } static inline struct lov_thread_info *lov_env_info(const struct lu_env *env) { struct lov_thread_info *info; info = lu_context_key_get(&env->le_ctx, &lov_key); LASSERT(info != NULL); return info; } static inline struct lov_layout_raid0 *lov_r0(struct lov_object *lov) { LASSERT(lov->lo_type == LLT_RAID0); LASSERT(lov->lo_lsm->lsm_wire.lw_magic == LOV_MAGIC || lov->lo_lsm->lsm_wire.lw_magic == LOV_MAGIC_V3); return &lov->u.raid0; } /** @} lov */ #endif