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Diffstat (limited to 'drivers/staging/lustre/lustre/osc/osc_cl_internal.h')
| -rw-r--r-- | drivers/staging/lustre/lustre/osc/osc_cl_internal.h | 677 |
1 files changed, 677 insertions, 0 deletions
diff --git a/drivers/staging/lustre/lustre/osc/osc_cl_internal.h b/drivers/staging/lustre/lustre/osc/osc_cl_internal.h new file mode 100644 index 000000000000..158e8fff838f --- /dev/null +++ b/drivers/staging/lustre/lustre/osc/osc_cl_internal.h @@ -0,0 +1,677 @@ +/* + * 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, 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 OSC layer. + * + * Author: Nikita Danilov <nikita.danilov@sun.com> + * Author: Jinshan Xiong <jinshan.xiong@whamcloud.com> + */ + +#ifndef OSC_CL_INTERNAL_H +#define OSC_CL_INTERNAL_H + +# include <linux/libcfs/libcfs.h> + +#include <obd.h> +/* osc_build_res_name() */ +#include <obd_ost.h> +#include <cl_object.h> +#include <lclient.h> +#include "osc_internal.h" + +/** \defgroup osc osc + * @{ + */ + +struct osc_extent; + +/** + * State maintained by osc layer for each IO context. + */ +struct osc_io { + /** super class */ + struct cl_io_slice oi_cl; + /** true if this io is lockless. */ + int oi_lockless; + /** active extents, we know how many bytes is going to be written, + * so having an active extent will prevent it from being fragmented */ + struct osc_extent *oi_active; + /** partially truncated extent, we need to hold this extent to prevent + * page writeback from happening. */ + struct osc_extent *oi_trunc; + + struct obd_info oi_info; + struct obdo oi_oa; + struct osc_async_cbargs { + bool opc_rpc_sent; + int opc_rc; + struct completion opc_sync; + } oi_cbarg; +}; + +/** + * State of transfer for osc. + */ +struct osc_req { + struct cl_req_slice or_cl; +}; + +/** + * State maintained by osc layer for the duration of a system call. + */ +struct osc_session { + struct osc_io os_io; +}; + +#define OTI_PVEC_SIZE 64 +struct osc_thread_info { + struct ldlm_res_id oti_resname; + ldlm_policy_data_t oti_policy; + struct cl_lock_descr oti_descr; + struct cl_attr oti_attr; + struct lustre_handle oti_handle; + struct cl_page_list oti_plist; + struct cl_io oti_io; + struct cl_page *oti_pvec[OTI_PVEC_SIZE]; +}; + +struct osc_object { + struct cl_object oo_cl; + struct lov_oinfo *oo_oinfo; + /** + * True if locking against this stripe got -EUSERS. + */ + int oo_contended; + cfs_time_t oo_contention_time; + /** + * List of pages in transfer. + */ + struct list_head oo_inflight[CRT_NR]; + /** + * Lock, protecting ccc_object::cob_inflight, because a seat-belt is + * locked during take-off and landing. + */ + spinlock_t oo_seatbelt; + + /** + * used by the osc to keep track of what objects to build into rpcs. + * Protected by client_obd->cli_loi_list_lock. + */ + struct list_head oo_ready_item; + struct list_head oo_hp_ready_item; + struct list_head oo_write_item; + struct list_head oo_read_item; + + /** + * extent is a red black tree to manage (async) dirty pages. + */ + struct rb_root oo_root; + /** + * Manage write(dirty) extents. + */ + struct list_head oo_hp_exts; /* list of hp extents */ + struct list_head oo_urgent_exts; /* list of writeback extents */ + struct list_head oo_rpc_exts; + + struct list_head oo_reading_exts; + + atomic_t oo_nr_reads; + atomic_t oo_nr_writes; + + /** Protect extent tree. Will be used to protect + * oo_{read|write}_pages soon. */ + spinlock_t oo_lock; +}; + +static inline void osc_object_lock(struct osc_object *obj) +{ + spin_lock(&obj->oo_lock); +} + +static inline int osc_object_trylock(struct osc_object *obj) +{ + return spin_trylock(&obj->oo_lock); +} + +static inline void osc_object_unlock(struct osc_object *obj) +{ + spin_unlock(&obj->oo_lock); +} + +static inline int osc_object_is_locked(struct osc_object *obj) +{ + return spin_is_locked(&obj->oo_lock); +} + +/* + * Lock "micro-states" for osc layer. + */ +enum osc_lock_state { + OLS_NEW, + OLS_ENQUEUED, + OLS_UPCALL_RECEIVED, + OLS_GRANTED, + OLS_RELEASED, + OLS_BLOCKED, + OLS_CANCELLED +}; + +/** + * osc-private state of cl_lock. + * + * Interaction with DLM. + * + * CLIO enqueues all DLM locks through ptlrpcd (that is, in "async" mode). + * + * Once receive upcall is invoked, osc_lock remembers a handle of DLM lock in + * osc_lock::ols_handle and a pointer to that lock in osc_lock::ols_lock. + * + * This pointer is protected through a reference, acquired by + * osc_lock_upcall0(). Also, an additional reference is acquired by + * ldlm_lock_addref() call protecting the lock from cancellation, until + * osc_lock_unuse() releases it. + * + * Below is a description of how lock references are acquired and released + * inside of DLM. + * + * - When new lock is created and enqueued to the server (ldlm_cli_enqueue()) + * - ldlm_lock_create() + * - ldlm_lock_new(): initializes a lock with 2 references. One for + * the caller (released when reply from the server is received, or on + * error), and another for the hash table. + * - ldlm_lock_addref_internal(): protects the lock from cancellation. + * + * - When reply is received from the server (osc_enqueue_interpret()) + * - ldlm_cli_enqueue_fini() + * - LDLM_LOCK_PUT(): releases caller reference acquired by + * ldlm_lock_new(). + * - if (rc != 0) + * ldlm_lock_decref(): error case: matches ldlm_cli_enqueue(). + * - ldlm_lock_decref(): for async locks, matches ldlm_cli_enqueue(). + * + * - When lock is being cancelled (ldlm_lock_cancel()) + * - ldlm_lock_destroy() + * - LDLM_LOCK_PUT(): releases hash-table reference acquired by + * ldlm_lock_new(). + * + * osc_lock is detached from ldlm_lock by osc_lock_detach() that is called + * either when lock is cancelled (osc_lock_blocking()), or when locks is + * deleted without cancellation (e.g., from cl_locks_prune()). In the latter + * case ldlm lock remains in memory, and can be re-attached to osc_lock in the + * future. + */ +struct osc_lock { + struct cl_lock_slice ols_cl; + /** underlying DLM lock */ + struct ldlm_lock *ols_lock; + /** lock value block */ + struct ost_lvb ols_lvb; + /** DLM flags with which osc_lock::ols_lock was enqueued */ + __u64 ols_flags; + /** osc_lock::ols_lock handle */ + struct lustre_handle ols_handle; + struct ldlm_enqueue_info ols_einfo; + enum osc_lock_state ols_state; + + /** + * How many pages are using this lock for io, currently only used by + * read-ahead. If non-zero, the underlying dlm lock won't be cancelled + * during recovery to avoid deadlock. see bz16774. + * + * \see osc_page::ops_lock + * \see osc_page_addref_lock(), osc_page_putref_lock() + */ + atomic_t ols_pageref; + + /** + * true, if ldlm_lock_addref() was called against + * osc_lock::ols_lock. This is used for sanity checking. + * + * \see osc_lock::ols_has_ref + */ + unsigned ols_hold :1, + /** + * this is much like osc_lock::ols_hold, except that this bit is + * cleared _after_ reference in released in osc_lock_unuse(). This + * fine distinction is needed because: + * + * - if ldlm lock still has a reference, osc_ast_data_get() needs + * to return associated cl_lock (so that a flag is needed that is + * cleared after ldlm_lock_decref() returned), and + * + * - ldlm_lock_decref() can invoke blocking ast (for a + * LDLM_FL_CBPENDING lock), and osc_lock functions like + * osc_lock_cancel() called from there need to know whether to + * release lock reference (so that a flag is needed that is + * cleared before ldlm_lock_decref() is called). + */ + ols_has_ref:1, + /** + * inherit the lockless attribute from top level cl_io. + * If true, osc_lock_enqueue is able to tolerate the -EUSERS error. + */ + ols_locklessable:1, + /** + * set by osc_lock_use() to wait until blocking AST enters into + * osc_ldlm_blocking_ast0(), so that cl_lock mutex can be used for + * further synchronization. + */ + ols_ast_wait:1, + /** + * If the data of this lock has been flushed to server side. + */ + ols_flush:1, + /** + * if set, the osc_lock is a glimpse lock. For glimpse locks, we treat + * the EVAVAIL error as torerable, this will make upper logic happy + * to wait all glimpse locks to each OSTs to be completed. + * Glimpse lock converts to normal lock if the server lock is + * granted. + * Glimpse lock should be destroyed immediately after use. + */ + ols_glimpse:1, + /** + * For async glimpse lock. + */ + ols_agl:1; + /** + * IO that owns this lock. This field is used for a dead-lock + * avoidance by osc_lock_enqueue_wait(). + * + * XXX: unfortunately, the owner of a osc_lock is not unique, + * the lock may have multiple users, if the lock is granted and + * then matched. + */ + struct osc_io *ols_owner; +}; + + +/** + * Page state private for osc layer. + */ +struct osc_page { + struct cl_page_slice ops_cl; + /** + * Page queues used by osc to detect when RPC can be formed. + */ + struct osc_async_page ops_oap; + /** + * An offset within page from which next transfer starts. This is used + * by cl_page_clip() to submit partial page transfers. + */ + int ops_from; + /** + * An offset within page at which next transfer ends. + * + * \see osc_page::ops_from. + */ + int ops_to; + /** + * Boolean, true iff page is under transfer. Used for sanity checking. + */ + unsigned ops_transfer_pinned:1, + /** + * True for a `temporary page' created by read-ahead code, probably + * outside of any DLM lock. + */ + ops_temp:1, + /** + * in LRU? + */ + ops_in_lru:1, + /** + * Set if the page must be transferred with OBD_BRW_SRVLOCK. + */ + ops_srvlock:1; + union { + /** + * lru page list. ops_inflight and ops_lru are exclusive so + * that they can share the same data. + */ + struct list_head ops_lru; + /** + * Linkage into a per-osc_object list of pages in flight. For + * debugging. + */ + struct list_head ops_inflight; + }; + /** + * Thread that submitted this page for transfer. For debugging. + */ + task_t *ops_submitter; + /** + * Submit time - the time when the page is starting RPC. For debugging. + */ + cfs_time_t ops_submit_time; + + /** + * A lock of which we hold a reference covers this page. Only used by + * read-ahead: for a readahead page, we hold it's covering lock to + * prevent it from being canceled during recovery. + * + * \see osc_lock::ols_pageref + * \see osc_page_addref_lock(), osc_page_putref_lock(). + */ + struct cl_lock *ops_lock; +}; + +extern struct kmem_cache *osc_lock_kmem; +extern struct kmem_cache *osc_object_kmem; +extern struct kmem_cache *osc_thread_kmem; +extern struct kmem_cache *osc_session_kmem; +extern struct kmem_cache *osc_req_kmem; +extern struct kmem_cache *osc_extent_kmem; + +extern struct lu_device_type osc_device_type; +extern struct lu_context_key osc_key; +extern struct lu_context_key osc_session_key; + +#define OSC_FLAGS (ASYNC_URGENT|ASYNC_READY) + +int osc_lock_init(const struct lu_env *env, + struct cl_object *obj, struct cl_lock *lock, + const struct cl_io *io); +int osc_io_init (const struct lu_env *env, + struct cl_object *obj, struct cl_io *io); +int osc_req_init (const struct lu_env *env, struct cl_device *dev, + struct cl_req *req); +struct lu_object *osc_object_alloc(const struct lu_env *env, + const struct lu_object_header *hdr, + struct lu_device *dev); +int osc_page_init(const struct lu_env *env, struct cl_object *obj, + struct cl_page *page, struct page *vmpage); + +void osc_index2policy (ldlm_policy_data_t *policy, const struct cl_object *obj, + pgoff_t start, pgoff_t end); +int osc_lvb_print (const struct lu_env *env, void *cookie, + lu_printer_t p, const struct ost_lvb *lvb); + +void osc_page_submit(const struct lu_env *env, struct osc_page *opg, + enum cl_req_type crt, int brw_flags); +int osc_cancel_async_page(const struct lu_env *env, struct osc_page *ops); +int osc_set_async_flags(struct osc_object *obj, struct osc_page *opg, + obd_flag async_flags); +int osc_prep_async_page(struct osc_object *osc, struct osc_page *ops, + struct page *page, loff_t offset); +int osc_queue_async_io(const struct lu_env *env, struct cl_io *io, + struct osc_page *ops); +int osc_teardown_async_page(const struct lu_env *env, struct osc_object *obj, + struct osc_page *ops); +int osc_flush_async_page(const struct lu_env *env, struct cl_io *io, + struct osc_page *ops); +int osc_queue_sync_pages(const struct lu_env *env, struct osc_object *obj, + struct list_head *list, int cmd, int brw_flags); +int osc_cache_truncate_start(const struct lu_env *env, struct osc_io *oio, + struct osc_object *obj, __u64 size); +void osc_cache_truncate_end(const struct lu_env *env, struct osc_io *oio, + struct osc_object *obj); +int osc_cache_writeback_range(const struct lu_env *env, struct osc_object *obj, + pgoff_t start, pgoff_t end, int hp, int discard); +int osc_cache_wait_range(const struct lu_env *env, struct osc_object *obj, + pgoff_t start, pgoff_t end); +void osc_io_unplug(const struct lu_env *env, struct client_obd *cli, + struct osc_object *osc, pdl_policy_t pol); + +void osc_object_set_contended (struct osc_object *obj); +void osc_object_clear_contended(struct osc_object *obj); +int osc_object_is_contended (struct osc_object *obj); + +int osc_lock_is_lockless (const struct osc_lock *olck); + +/***************************************************************************** + * + * Accessors. + * + */ + +static inline struct osc_thread_info *osc_env_info(const struct lu_env *env) +{ + struct osc_thread_info *info; + + info = lu_context_key_get(&env->le_ctx, &osc_key); + LASSERT(info != NULL); + return info; +} + +static inline struct osc_session *osc_env_session(const struct lu_env *env) +{ + struct osc_session *ses; + + ses = lu_context_key_get(env->le_ses, &osc_session_key); + LASSERT(ses != NULL); + return ses; +} + +static inline struct osc_io *osc_env_io(const struct lu_env *env) +{ + return &osc_env_session(env)->os_io; +} + +static inline int osc_is_object(const struct lu_object *obj) +{ + return obj->lo_dev->ld_type == &osc_device_type; +} + +static inline struct osc_device *lu2osc_dev(const struct lu_device *d) +{ + LINVRNT(d->ld_type == &osc_device_type); + return container_of0(d, struct osc_device, od_cl.cd_lu_dev); +} + +static inline struct obd_export *osc_export(const struct osc_object *obj) +{ + return lu2osc_dev(obj->oo_cl.co_lu.lo_dev)->od_exp; +} + +static inline struct client_obd *osc_cli(const struct osc_object *obj) +{ + return &osc_export(obj)->exp_obd->u.cli; +} + +static inline struct osc_object *cl2osc(const struct cl_object *obj) +{ + LINVRNT(osc_is_object(&obj->co_lu)); + return container_of0(obj, struct osc_object, oo_cl); +} + +static inline struct cl_object *osc2cl(const struct osc_object *obj) +{ + return (struct cl_object *)&obj->oo_cl; +} + +static inline ldlm_mode_t osc_cl_lock2ldlm(enum cl_lock_mode mode) +{ + LASSERT(mode == CLM_READ || mode == CLM_WRITE || mode == CLM_GROUP); + if (mode == CLM_READ) + return LCK_PR; + else if (mode == CLM_WRITE) + return LCK_PW; + else + return LCK_GROUP; +} + +static inline enum cl_lock_mode osc_ldlm2cl_lock(ldlm_mode_t mode) +{ + LASSERT(mode == LCK_PR || mode == LCK_PW || mode == LCK_GROUP); + if (mode == LCK_PR) + return CLM_READ; + else if (mode == LCK_PW) + return CLM_WRITE; + else + return CLM_GROUP; +} + +static inline struct osc_page *cl2osc_page(const struct cl_page_slice *slice) +{ + LINVRNT(osc_is_object(&slice->cpl_obj->co_lu)); + return container_of0(slice, struct osc_page, ops_cl); +} + +static inline struct osc_page *oap2osc(struct osc_async_page *oap) +{ + return container_of0(oap, struct osc_page, ops_oap); +} + +static inline struct cl_page *oap2cl_page(struct osc_async_page *oap) +{ + return oap2osc(oap)->ops_cl.cpl_page; +} + +static inline struct osc_page *oap2osc_page(struct osc_async_page *oap) +{ + return (struct osc_page *)container_of(oap, struct osc_page, ops_oap); +} + +static inline struct osc_lock *cl2osc_lock(const struct cl_lock_slice *slice) +{ + LINVRNT(osc_is_object(&slice->cls_obj->co_lu)); + return container_of0(slice, struct osc_lock, ols_cl); +} + +static inline struct osc_lock *osc_lock_at(const struct cl_lock *lock) +{ + return cl2osc_lock(cl_lock_at(lock, &osc_device_type)); +} + +static inline int osc_io_srvlock(struct osc_io *oio) +{ + return (oio->oi_lockless && !oio->oi_cl.cis_io->ci_no_srvlock); +} + +enum osc_extent_state { + OES_INV = 0, /** extent is just initialized or destroyed */ + OES_ACTIVE = 1, /** process is using this extent */ + OES_CACHE = 2, /** extent is ready for IO */ + OES_LOCKING = 3, /** locking page to prepare IO */ + OES_LOCK_DONE = 4, /** locking finished, ready to send */ + OES_RPC = 5, /** in RPC */ + OES_TRUNC = 6, /** being truncated */ + OES_STATE_MAX +}; + +/** + * osc_extent data to manage dirty pages. + * osc_extent has the following attributes: + * 1. all pages in the same must be in one RPC in write back; + * 2. # of pages must be less than max_pages_per_rpc - implied by 1; + * 3. must be covered by only 1 osc_lock; + * 4. exclusive. It's impossible to have overlapped osc_extent. + * + * The lifetime of an extent is from when the 1st page is dirtied to when + * all pages inside it are written out. + * + * LOCKING ORDER + * ============= + * page lock -> client_obd_list_lock -> object lock(osc_object::oo_lock) + */ +struct osc_extent { + /** red-black tree node */ + struct rb_node oe_node; + /** osc_object of this extent */ + struct osc_object *oe_obj; + /** refcount, removed from red-black tree if reaches zero. */ + atomic_t oe_refc; + /** busy if non-zero */ + atomic_t oe_users; + /** link list of osc_object's oo_{hp|urgent|locking}_exts. */ + struct list_head oe_link; + /** state of this extent */ + unsigned int oe_state; + /** flags for this extent. */ + unsigned int oe_intree:1, + /** 0 is write, 1 is read */ + oe_rw:1, + oe_srvlock:1, + oe_memalloc:1, + /** an ACTIVE extent is going to be truncated, so when this extent + * is released, it will turn into TRUNC state instead of CACHE. */ + oe_trunc_pending:1, + /** this extent should be written asap and someone may wait for the + * write to finish. This bit is usually set along with urgent if + * the extent was CACHE state. + * fsync_wait extent can't be merged because new extent region may + * exceed fsync range. */ + oe_fsync_wait:1, + /** covering lock is being canceled */ + oe_hp:1, + /** this extent should be written back asap. set if one of pages is + * called by page WB daemon, or sync write or reading requests. */ + oe_urgent:1; + /** how many grants allocated for this extent. + * Grant allocated for this extent. There is no grant allocated + * for reading extents and sync write extents. */ + unsigned int oe_grants; + /** # of dirty pages in this extent */ + unsigned int oe_nr_pages; + /** list of pending oap pages. Pages in this list are NOT sorted. */ + struct list_head oe_pages; + /** Since an extent has to be written out in atomic, this is used to + * remember the next page need to be locked to write this extent out. + * Not used right now. + */ + struct osc_page *oe_next_page; + /** start and end index of this extent, include start and end + * themselves. Page offset here is the page index of osc_pages. + * oe_start is used as keyword for red-black tree. */ + pgoff_t oe_start; + pgoff_t oe_end; + /** maximum ending index of this extent, this is limited by + * max_pages_per_rpc, lock extent and chunk size. */ + pgoff_t oe_max_end; + /** waitqueue - for those who want to be notified if this extent's + * state has changed. */ + wait_queue_head_t oe_waitq; + /** lock covering this extent */ + struct cl_lock *oe_osclock; + /** terminator of this extent. Must be true if this extent is in IO. */ + task_t *oe_owner; + /** return value of writeback. If somebody is waiting for this extent, + * this value can be known by outside world. */ + int oe_rc; + /** max pages per rpc when this extent was created */ + unsigned int oe_mppr; +}; + +int osc_extent_finish(const struct lu_env *env, struct osc_extent *ext, + int sent, int rc); +int osc_extent_release(const struct lu_env *env, struct osc_extent *ext); + +/** @} osc */ + +#endif /* OSC_CL_INTERNAL_H */ |