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40 * Internal interfaces of OSC layer.
42 * Author: Nikita Danilov <nikita.danilov@sun.com>
43 * Author: Jinshan Xiong <jinshan.xiong@whamcloud.com>
46 #ifndef OSC_CL_INTERNAL_H
47 #define OSC_CL_INTERNAL_H
49 #include <libcfs/libcfs.h>
51 /* osc_build_res_name() */
52 #include <cl_object.h>
54 #include "osc_internal.h"
63 * State maintained by osc layer for each IO context.
67 struct cl_io_slice oi_cl;
68 /** true if this io is lockless. */
70 /** how many LRU pages are reserved for this IO */
73 /** active extents, we know how many bytes is going to be written,
74 * so having an active extent will prevent it from being fragmented */
75 struct osc_extent *oi_active;
76 /** partially truncated extent, we need to hold this extent to prevent
77 * page writeback from happening. */
78 struct osc_extent *oi_trunc;
79 /** write osc_lock for this IO, used by osc_extent_find(). */
80 struct osc_lock *oi_write_osclock;
82 struct obd_info oi_info;
84 struct osc_async_cbargs {
87 struct completion opc_sync;
92 * State of transfer for osc.
95 struct cl_req_slice or_cl;
99 * State maintained by osc layer for the duration of a system call.
105 #define OTI_PVEC_SIZE 256
106 struct osc_thread_info {
107 struct ldlm_res_id oti_resname;
108 ldlm_policy_data_t oti_policy;
109 struct cl_lock_descr oti_descr;
110 struct cl_attr oti_attr;
111 struct lustre_handle oti_handle;
112 struct cl_page_list oti_plist;
114 void *oti_pvec[OTI_PVEC_SIZE];
116 * Fields used by cl_lock_discard_pages().
118 pgoff_t oti_next_index;
119 pgoff_t oti_fn_index; /* first non-overlapped index */
120 struct cl_sync_io oti_anchor;
124 struct cl_object oo_cl;
125 struct lov_oinfo *oo_oinfo;
127 * True if locking against this stripe got -EUSERS.
130 cfs_time_t oo_contention_time;
131 #ifdef CONFIG_LUSTRE_DEBUG_EXPENSIVE_CHECK
133 * IO context used for invariant checks in osc_lock_has_pages().
135 struct cl_io oo_debug_io;
136 /** Serialization object for osc_object::oo_debug_io. */
137 struct mutex oo_debug_mutex;
140 * List of pages in transfer.
142 struct list_head oo_inflight[CRT_NR];
144 * Lock, protecting ccc_object::cob_inflight, because a seat-belt is
145 * locked during take-off and landing.
147 spinlock_t oo_seatbelt;
150 * used by the osc to keep track of what objects to build into rpcs.
151 * Protected by client_obd->cli_loi_list_lock.
153 struct list_head oo_ready_item;
154 struct list_head oo_hp_ready_item;
155 struct list_head oo_write_item;
156 struct list_head oo_read_item;
159 * extent is a red black tree to manage (async) dirty pages.
161 struct rb_root oo_root;
163 * Manage write(dirty) extents.
165 struct list_head oo_hp_exts; /* list of hp extents */
166 struct list_head oo_urgent_exts; /* list of writeback extents */
167 struct list_head oo_rpc_exts;
169 struct list_head oo_reading_exts;
171 atomic_t oo_nr_reads;
172 atomic_t oo_nr_writes;
174 /** Protect extent tree. Will be used to protect
175 * oo_{read|write}_pages soon. */
179 * Radix tree for caching pages
181 struct radix_tree_root oo_tree;
182 spinlock_t oo_tree_lock;
183 unsigned long oo_npages;
185 /* Protect osc_lock this osc_object has */
186 spinlock_t oo_ol_spin;
187 struct list_head oo_ol_list;
190 static inline void osc_object_lock(struct osc_object *obj)
192 spin_lock(&obj->oo_lock);
195 static inline int osc_object_trylock(struct osc_object *obj)
197 return spin_trylock(&obj->oo_lock);
200 static inline void osc_object_unlock(struct osc_object *obj)
202 spin_unlock(&obj->oo_lock);
205 static inline int osc_object_is_locked(struct osc_object *obj)
207 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
208 return spin_is_locked(&obj->oo_lock);
211 * It is not perfect to return true all the time.
212 * But since this function is only used for assertion
213 * and checking, it seems OK.
220 * Lock "micro-states" for osc layer.
222 enum osc_lock_state {
231 * osc-private state of cl_lock.
233 * Interaction with DLM.
235 * Once receive upcall is invoked, osc_lock remembers a handle of DLM lock in
236 * osc_lock::ols_handle and a pointer to that lock in osc_lock::ols_dlmlock.
238 * This pointer is protected through a reference, acquired by
239 * osc_lock_upcall0(). Also, an additional reference is acquired by
240 * ldlm_lock_addref() call protecting the lock from cancellation, until
241 * osc_lock_unuse() releases it.
243 * Below is a description of how lock references are acquired and released
246 * - When new lock is created and enqueued to the server (ldlm_cli_enqueue())
247 * - ldlm_lock_create()
248 * - ldlm_lock_new(): initializes a lock with 2 references. One for
249 * the caller (released when reply from the server is received, or on
250 * error), and another for the hash table.
251 * - ldlm_lock_addref_internal(): protects the lock from cancellation.
253 * - When reply is received from the server (osc_enqueue_interpret())
254 * - ldlm_cli_enqueue_fini()
255 * - LDLM_LOCK_PUT(): releases caller reference acquired by
258 * ldlm_lock_decref(): error case: matches ldlm_cli_enqueue().
259 * - ldlm_lock_decref(): for async locks, matches ldlm_cli_enqueue().
261 * - When lock is being cancelled (ldlm_lock_cancel())
262 * - ldlm_lock_destroy()
263 * - LDLM_LOCK_PUT(): releases hash-table reference acquired by
266 * osc_lock is detached from ldlm_lock by osc_lock_detach() that is called
267 * either when lock is cancelled (osc_lock_blocking()), or when locks is
268 * deleted without cancellation (e.g., from cl_locks_prune()). In the latter
269 * case ldlm lock remains in memory, and can be re-attached to osc_lock in the
273 struct cl_lock_slice ols_cl;
274 /** Internal lock to protect states, etc. */
276 /** Owner sleeps on this channel for state change */
277 struct cl_sync_io *ols_owner;
278 /** waiting list for this lock to be cancelled */
279 struct list_head ols_waiting_list;
280 /** wait entry of ols_waiting_list */
281 struct list_head ols_wait_entry;
282 /** list entry for osc_object::oo_ol_list */
283 struct list_head ols_nextlock_oscobj;
285 /** underlying DLM lock */
286 struct ldlm_lock *ols_dlmlock;
287 /** DLM flags with which osc_lock::ols_lock was enqueued */
289 /** osc_lock::ols_lock handle */
290 struct lustre_handle ols_handle;
291 struct ldlm_enqueue_info ols_einfo;
292 enum osc_lock_state ols_state;
293 /** lock value block */
294 struct ost_lvb ols_lvb;
297 * true, if ldlm_lock_addref() was called against
298 * osc_lock::ols_lock. This is used for sanity checking.
300 * \see osc_lock::ols_has_ref
302 unsigned ols_hold :1,
304 * this is much like osc_lock::ols_hold, except that this bit is
305 * cleared _after_ reference in released in osc_lock_unuse(). This
306 * fine distinction is needed because:
308 * - if ldlm lock still has a reference, osc_ast_data_get() needs
309 * to return associated cl_lock (so that a flag is needed that is
310 * cleared after ldlm_lock_decref() returned), and
312 * - ldlm_lock_decref() can invoke blocking ast (for a
313 * LDLM_FL_CBPENDING lock), and osc_lock functions like
314 * osc_lock_cancel() called from there need to know whether to
315 * release lock reference (so that a flag is needed that is
316 * cleared before ldlm_lock_decref() is called).
320 * inherit the lockless attribute from top level cl_io.
321 * If true, osc_lock_enqueue is able to tolerate the -EUSERS error.
325 * if set, the osc_lock is a glimpse lock. For glimpse locks, we treat
326 * the EVAVAIL error as torerable, this will make upper logic happy
327 * to wait all glimpse locks to each OSTs to be completed.
328 * Glimpse lock converts to normal lock if the server lock is
330 * Glimpse lock should be destroyed immediately after use.
334 * For async glimpse lock.
341 * Page state private for osc layer.
344 struct cl_page_slice ops_cl;
346 * Page queues used by osc to detect when RPC can be formed.
348 struct osc_async_page ops_oap;
350 * An offset within page from which next transfer starts. This is used
351 * by cl_page_clip() to submit partial page transfers.
355 * An offset within page at which next transfer ends.
357 * \see osc_page::ops_from.
361 * Boolean, true iff page is under transfer. Used for sanity checking.
363 unsigned ops_transfer_pinned:1,
365 * True for a `temporary page' created by read-ahead code, probably
366 * outside of any DLM lock.
374 * Set if the page must be transferred with OBD_BRW_SRVLOCK.
378 * lru page list. See osc_lru_{del|use}() in osc_page.c for usage.
380 struct list_head ops_lru;
382 * Linkage into a per-osc_object list of pages in flight. For
385 struct list_head ops_inflight;
387 * Thread that submitted this page for transfer. For debugging.
389 struct task_struct *ops_submitter;
391 * Submit time - the time when the page is starting RPC. For debugging.
393 cfs_time_t ops_submit_time;
396 extern struct kmem_cache *osc_lock_kmem;
397 extern struct kmem_cache *osc_object_kmem;
398 extern struct kmem_cache *osc_thread_kmem;
399 extern struct kmem_cache *osc_session_kmem;
400 extern struct kmem_cache *osc_req_kmem;
401 extern struct kmem_cache *osc_extent_kmem;
403 extern struct lu_device_type osc_device_type;
404 extern struct lu_context_key osc_key;
405 extern struct lu_context_key osc_session_key;
407 #define OSC_FLAGS (ASYNC_URGENT|ASYNC_READY)
409 int osc_lock_init(const struct lu_env *env,
410 struct cl_object *obj, struct cl_lock *lock,
411 const struct cl_io *io);
412 int osc_io_init (const struct lu_env *env,
413 struct cl_object *obj, struct cl_io *io);
414 int osc_req_init (const struct lu_env *env, struct cl_device *dev,
416 struct lu_object *osc_object_alloc(const struct lu_env *env,
417 const struct lu_object_header *hdr,
418 struct lu_device *dev);
419 int osc_page_init(const struct lu_env *env, struct cl_object *obj,
420 struct cl_page *page, pgoff_t ind);
422 void osc_index2policy (ldlm_policy_data_t *policy, const struct cl_object *obj,
423 pgoff_t start, pgoff_t end);
424 int osc_lvb_print (const struct lu_env *env, void *cookie,
425 lu_printer_t p, const struct ost_lvb *lvb);
427 void osc_lru_add_batch(struct client_obd *cli, struct list_head *list);
428 void osc_page_submit(const struct lu_env *env, struct osc_page *opg,
429 enum cl_req_type crt, int brw_flags);
430 int osc_cancel_async_page(const struct lu_env *env, struct osc_page *ops);
431 int osc_set_async_flags(struct osc_object *obj, struct osc_page *opg,
432 obd_flag async_flags);
433 int osc_prep_async_page(struct osc_object *osc, struct osc_page *ops,
434 struct page *page, loff_t offset);
435 int osc_queue_async_io(const struct lu_env *env, struct cl_io *io,
436 struct osc_page *ops);
437 int osc_page_cache_add(const struct lu_env *env,
438 const struct cl_page_slice *slice, struct cl_io *io);
439 int osc_teardown_async_page(const struct lu_env *env, struct osc_object *obj,
440 struct osc_page *ops);
441 int osc_flush_async_page(const struct lu_env *env, struct cl_io *io,
442 struct osc_page *ops);
443 int osc_queue_sync_pages(const struct lu_env *env, struct osc_object *obj,
444 struct list_head *list, int cmd, int brw_flags);
445 int osc_cache_truncate_start(const struct lu_env *env, struct osc_io *oio,
446 struct osc_object *obj, __u64 size);
447 void osc_cache_truncate_end(const struct lu_env *env, struct osc_io *oio,
448 struct osc_object *obj);
449 int osc_cache_writeback_range(const struct lu_env *env, struct osc_object *obj,
450 pgoff_t start, pgoff_t end, int hp, int discard);
451 int osc_cache_wait_range(const struct lu_env *env, struct osc_object *obj,
452 pgoff_t start, pgoff_t end);
453 void osc_io_unplug(const struct lu_env *env, struct client_obd *cli,
454 struct osc_object *osc, pdl_policy_t pol);
455 int lru_queue_work(const struct lu_env *env, void *data);
457 void osc_object_set_contended (struct osc_object *obj);
458 void osc_object_clear_contended(struct osc_object *obj);
459 int osc_object_is_contended (struct osc_object *obj);
461 int osc_lock_is_lockless (const struct osc_lock *olck);
463 /*****************************************************************************
469 static inline struct osc_thread_info *osc_env_info(const struct lu_env *env)
471 struct osc_thread_info *info;
473 info = lu_context_key_get(&env->le_ctx, &osc_key);
474 LASSERT(info != NULL);
478 static inline struct osc_session *osc_env_session(const struct lu_env *env)
480 struct osc_session *ses;
482 ses = lu_context_key_get(env->le_ses, &osc_session_key);
483 LASSERT(ses != NULL);
487 static inline struct osc_io *osc_env_io(const struct lu_env *env)
489 return &osc_env_session(env)->os_io;
492 static inline int osc_is_object(const struct lu_object *obj)
494 return obj->lo_dev->ld_type == &osc_device_type;
497 static inline struct osc_device *lu2osc_dev(const struct lu_device *d)
499 LINVRNT(d->ld_type == &osc_device_type);
500 return container_of0(d, struct osc_device, od_cl.cd_lu_dev);
503 static inline struct obd_export *osc_export(const struct osc_object *obj)
505 return lu2osc_dev(obj->oo_cl.co_lu.lo_dev)->od_exp;
508 static inline struct client_obd *osc_cli(const struct osc_object *obj)
510 return &osc_export(obj)->exp_obd->u.cli;
513 static inline struct osc_object *cl2osc(const struct cl_object *obj)
515 LINVRNT(osc_is_object(&obj->co_lu));
516 return container_of0(obj, struct osc_object, oo_cl);
519 static inline struct cl_object *osc2cl(const struct osc_object *obj)
521 return (struct cl_object *)&obj->oo_cl;
524 static inline ldlm_mode_t osc_cl_lock2ldlm(enum cl_lock_mode mode)
526 LASSERT(mode == CLM_READ || mode == CLM_WRITE || mode == CLM_GROUP);
527 if (mode == CLM_READ)
529 else if (mode == CLM_WRITE)
535 static inline enum cl_lock_mode osc_ldlm2cl_lock(ldlm_mode_t mode)
537 LASSERT(mode == LCK_PR || mode == LCK_PW || mode == LCK_GROUP);
540 else if (mode == LCK_PW)
546 static inline struct osc_page *cl2osc_page(const struct cl_page_slice *slice)
548 LINVRNT(osc_is_object(&slice->cpl_obj->co_lu));
549 return container_of0(slice, struct osc_page, ops_cl);
552 static inline struct osc_page *oap2osc(struct osc_async_page *oap)
554 return container_of0(oap, struct osc_page, ops_oap);
557 static inline pgoff_t osc_index(struct osc_page *opg)
559 return opg->ops_cl.cpl_index;
562 static inline struct cl_page *oap2cl_page(struct osc_async_page *oap)
564 return oap2osc(oap)->ops_cl.cpl_page;
567 static inline struct osc_page *oap2osc_page(struct osc_async_page *oap)
569 return (struct osc_page *)container_of(oap, struct osc_page, ops_oap);
572 static inline struct osc_lock *cl2osc_lock(const struct cl_lock_slice *slice)
574 LINVRNT(osc_is_object(&slice->cls_obj->co_lu));
575 return container_of0(slice, struct osc_lock, ols_cl);
578 static inline struct osc_lock *osc_lock_at(const struct cl_lock *lock)
580 return cl2osc_lock(cl_lock_at(lock, &osc_device_type));
583 static inline int osc_io_srvlock(struct osc_io *oio)
585 return (oio->oi_lockless && !oio->oi_cl.cis_io->ci_no_srvlock);
588 enum osc_extent_state {
589 OES_INV = 0, /** extent is just initialized or destroyed */
590 OES_ACTIVE = 1, /** process is using this extent */
591 OES_CACHE = 2, /** extent is ready for IO */
592 OES_LOCKING = 3, /** locking page to prepare IO */
593 OES_LOCK_DONE = 4, /** locking finished, ready to send */
594 OES_RPC = 5, /** in RPC */
595 OES_TRUNC = 6, /** being truncated */
600 * osc_extent data to manage dirty pages.
601 * osc_extent has the following attributes:
602 * 1. all pages in the same must be in one RPC in write back;
603 * 2. # of pages must be less than max_pages_per_rpc - implied by 1;
604 * 3. must be covered by only 1 osc_lock;
605 * 4. exclusive. It's impossible to have overlapped osc_extent.
607 * The lifetime of an extent is from when the 1st page is dirtied to when
608 * all pages inside it are written out.
612 * page lock -> client_obd_list_lock -> object lock(osc_object::oo_lock)
615 /** red-black tree node */
616 struct rb_node oe_node;
617 /** osc_object of this extent */
618 struct osc_object *oe_obj;
619 /** refcount, removed from red-black tree if reaches zero. */
621 /** busy if non-zero */
623 /** link list of osc_object's oo_{hp|urgent|locking}_exts. */
624 struct list_head oe_link;
625 /** state of this extent */
626 unsigned int oe_state;
627 /** flags for this extent. */
628 unsigned int oe_intree:1,
629 /** 0 is write, 1 is read */
631 /** sync extent, queued by osc_queue_sync_pages() */
635 /** an ACTIVE extent is going to be truncated, so when this extent
636 * is released, it will turn into TRUNC state instead of CACHE. */
638 /** this extent should be written asap and someone may wait for the
639 * write to finish. This bit is usually set along with urgent if
640 * the extent was CACHE state.
641 * fsync_wait extent can't be merged because new extent region may
642 * exceed fsync range. */
644 /** covering lock is being canceled */
646 /** this extent should be written back asap. set if one of pages is
647 * called by page WB daemon, or sync write or reading requests. */
649 /** how many grants allocated for this extent.
650 * Grant allocated for this extent. There is no grant allocated
651 * for reading extents and sync write extents. */
652 unsigned int oe_grants;
653 /** # of dirty pages in this extent */
654 unsigned int oe_nr_pages;
655 /** list of pending oap pages. Pages in this list are NOT sorted. */
656 struct list_head oe_pages;
657 /** Since an extent has to be written out in atomic, this is used to
658 * remember the next page need to be locked to write this extent out.
659 * Not used right now.
661 struct osc_page *oe_next_page;
662 /** start and end index of this extent, include start and end
663 * themselves. Page offset here is the page index of osc_pages.
664 * oe_start is used as keyword for red-black tree. */
667 /** maximum ending index of this extent, this is limited by
668 * max_pages_per_rpc, lock extent and chunk size. */
670 /** waitqueue - for those who want to be notified if this extent's
671 * state has changed. */
672 wait_queue_head_t oe_waitq;
673 /** lock covering this extent */
674 struct ldlm_lock *oe_dlmlock;
675 /** terminator of this extent. Must be true if this extent is in IO. */
676 struct task_struct *oe_owner;
677 /** return value of writeback. If somebody is waiting for this extent,
678 * this value can be known by outside world. */
680 /** max pages per rpc when this extent was created */
681 unsigned int oe_mppr;
684 int osc_extent_finish(const struct lu_env *env, struct osc_extent *ext,
686 int osc_extent_release(const struct lu_env *env, struct osc_extent *ext);
688 int osc_lock_discard_pages(const struct lu_env *env, struct osc_object *osc,
689 pgoff_t start, pgoff_t end, enum cl_lock_mode mode);
691 typedef int (*osc_page_gang_cbt)(const struct lu_env *, struct cl_io *,
692 struct osc_page *, void *);
693 int osc_page_gang_lookup(const struct lu_env *env, struct cl_io *io,
694 struct osc_object *osc, pgoff_t start, pgoff_t end,
695 osc_page_gang_cbt cb, void *cbdata);
698 #endif /* OSC_CL_INTERNAL_H */