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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
50 # include <libcfs/libcfs.h>
52 # include <liblustre.h>
56 /* osc_build_res_name() */
58 #include <cl_object.h>
60 #include "osc_internal.h"
69 * State maintained by osc layer for each IO context.
73 struct cl_io_slice oi_cl;
74 /** true if this io is lockless. */
76 /** active extents, we know how many bytes is going to be written,
77 * so having an active extent will prevent it from being fragmented */
78 struct osc_extent *oi_active;
79 /** partially truncated extent, we need to hold this extent to prevent
80 * page writeback from happening. */
81 struct osc_extent *oi_trunc;
83 struct obd_info oi_info;
85 struct osc_async_cbargs {
88 struct completion opc_sync;
93 * State of transfer for osc.
96 struct cl_req_slice or_cl;
100 * State maintained by osc layer for the duration of a system call.
106 #define OTI_PVEC_SIZE 64
107 struct osc_thread_info {
108 struct ldlm_res_id oti_resname;
109 ldlm_policy_data_t oti_policy;
110 struct cl_lock_descr oti_descr;
111 struct cl_attr oti_attr;
112 struct lustre_handle oti_handle;
113 struct cl_page_list oti_plist;
115 struct cl_page *oti_pvec[OTI_PVEC_SIZE];
119 struct cl_object oo_cl;
120 struct lov_oinfo *oo_oinfo;
122 * True if locking against this stripe got -EUSERS.
125 cfs_time_t oo_contention_time;
126 #ifdef CONFIG_LUSTRE_DEBUG_EXPENSIVE_CHECK
128 * IO context used for invariant checks in osc_lock_has_pages().
130 struct cl_io oo_debug_io;
131 /** Serialization object for osc_object::oo_debug_io. */
132 struct mutex oo_debug_mutex;
135 * List of pages in transfer.
137 cfs_list_t oo_inflight[CRT_NR];
139 * Lock, protecting ccc_object::cob_inflight, because a seat-belt is
140 * locked during take-off and landing.
142 spinlock_t oo_seatbelt;
145 * used by the osc to keep track of what objects to build into rpcs.
146 * Protected by client_obd->cli_loi_list_lock.
148 cfs_list_t oo_ready_item;
149 cfs_list_t oo_hp_ready_item;
150 cfs_list_t oo_write_item;
151 cfs_list_t oo_read_item;
154 * extent is a red black tree to manage (async) dirty pages.
156 struct rb_root oo_root;
158 * Manage write(dirty) extents.
160 cfs_list_t oo_hp_exts; /* list of hp extents */
161 cfs_list_t oo_urgent_exts; /* list of writeback extents */
162 cfs_list_t oo_rpc_exts;
164 cfs_list_t oo_reading_exts;
166 cfs_atomic_t oo_nr_reads;
167 cfs_atomic_t oo_nr_writes;
169 /** Protect extent tree. Will be used to protect
170 * oo_{read|write}_pages soon. */
174 static inline void osc_object_lock(struct osc_object *obj)
176 spin_lock(&obj->oo_lock);
179 static inline int osc_object_trylock(struct osc_object *obj)
181 return spin_trylock(&obj->oo_lock);
184 static inline void osc_object_unlock(struct osc_object *obj)
186 spin_unlock(&obj->oo_lock);
189 static inline int osc_object_is_locked(struct osc_object *obj)
191 return spin_is_locked(&obj->oo_lock);
195 * Lock "micro-states" for osc layer.
197 enum osc_lock_state {
208 * osc-private state of cl_lock.
210 * Interaction with DLM.
212 * CLIO enqueues all DLM locks through ptlrpcd (that is, in "async" mode).
214 * Once receive upcall is invoked, osc_lock remembers a handle of DLM lock in
215 * osc_lock::ols_handle and a pointer to that lock in osc_lock::ols_lock.
217 * This pointer is protected through a reference, acquired by
218 * osc_lock_upcall0(). Also, an additional reference is acquired by
219 * ldlm_lock_addref() call protecting the lock from cancellation, until
220 * osc_lock_unuse() releases it.
222 * Below is a description of how lock references are acquired and released
225 * - When new lock is created and enqueued to the server (ldlm_cli_enqueue())
226 * - ldlm_lock_create()
227 * - ldlm_lock_new(): initializes a lock with 2 references. One for
228 * the caller (released when reply from the server is received, or on
229 * error), and another for the hash table.
230 * - ldlm_lock_addref_internal(): protects the lock from cancellation.
232 * - When reply is received from the server (osc_enqueue_interpret())
233 * - ldlm_cli_enqueue_fini()
234 * - LDLM_LOCK_PUT(): releases caller reference acquired by
237 * ldlm_lock_decref(): error case: matches ldlm_cli_enqueue().
238 * - ldlm_lock_decref(): for async locks, matches ldlm_cli_enqueue().
240 * - When lock is being cancelled (ldlm_lock_cancel())
241 * - ldlm_lock_destroy()
242 * - LDLM_LOCK_PUT(): releases hash-table reference acquired by
245 * osc_lock is detached from ldlm_lock by osc_lock_detach() that is called
246 * either when lock is cancelled (osc_lock_blocking()), or when locks is
247 * deleted without cancellation (e.g., from cl_locks_prune()). In the latter
248 * case ldlm lock remains in memory, and can be re-attached to osc_lock in the
252 struct cl_lock_slice ols_cl;
253 /** underlying DLM lock */
254 struct ldlm_lock *ols_lock;
255 /** lock value block */
256 struct ost_lvb ols_lvb;
257 /** DLM flags with which osc_lock::ols_lock was enqueued */
259 /** osc_lock::ols_lock handle */
260 struct lustre_handle ols_handle;
261 struct ldlm_enqueue_info ols_einfo;
262 enum osc_lock_state ols_state;
265 * How many pages are using this lock for io, currently only used by
266 * read-ahead. If non-zero, the underlying dlm lock won't be cancelled
267 * during recovery to avoid deadlock. see bz16774.
269 * \see osc_page::ops_lock
270 * \see osc_page_addref_lock(), osc_page_putref_lock()
272 cfs_atomic_t ols_pageref;
275 * true, if ldlm_lock_addref() was called against
276 * osc_lock::ols_lock. This is used for sanity checking.
278 * \see osc_lock::ols_has_ref
280 unsigned ols_hold :1,
282 * this is much like osc_lock::ols_hold, except that this bit is
283 * cleared _after_ reference in released in osc_lock_unuse(). This
284 * fine distinction is needed because:
286 * - if ldlm lock still has a reference, osc_ast_data_get() needs
287 * to return associated cl_lock (so that a flag is needed that is
288 * cleared after ldlm_lock_decref() returned), and
290 * - ldlm_lock_decref() can invoke blocking ast (for a
291 * LDLM_FL_CBPENDING lock), and osc_lock functions like
292 * osc_lock_cancel() called from there need to know whether to
293 * release lock reference (so that a flag is needed that is
294 * cleared before ldlm_lock_decref() is called).
298 * inherit the lockless attribute from top level cl_io.
299 * If true, osc_lock_enqueue is able to tolerate the -EUSERS error.
303 * set by osc_lock_use() to wait until blocking AST enters into
304 * osc_ldlm_blocking_ast0(), so that cl_lock mutex can be used for
305 * further synchronization.
309 * If the data of this lock has been flushed to server side.
313 * if set, the osc_lock is a glimpse lock. For glimpse locks, we treat
314 * the EVAVAIL error as torerable, this will make upper logic happy
315 * to wait all glimpse locks to each OSTs to be completed.
316 * Glimpse lock converts to normal lock if the server lock is
318 * Glimpse lock should be destroyed immediately after use.
322 * For async glimpse lock.
326 * IO that owns this lock. This field is used for a dead-lock
327 * avoidance by osc_lock_enqueue_wait().
329 * XXX: unfortunately, the owner of a osc_lock is not unique,
330 * the lock may have multiple users, if the lock is granted and
333 struct osc_io *ols_owner;
338 * Page state private for osc layer.
341 struct cl_page_slice ops_cl;
343 * Page queues used by osc to detect when RPC can be formed.
345 struct osc_async_page ops_oap;
347 * An offset within page from which next transfer starts. This is used
348 * by cl_page_clip() to submit partial page transfers.
352 * An offset within page at which next transfer ends.
354 * \see osc_page::ops_from.
358 * Boolean, true iff page is under transfer. Used for sanity checking.
360 unsigned ops_transfer_pinned:1,
362 * True for a `temporary page' created by read-ahead code, probably
363 * outside of any DLM lock.
371 * Set if the page must be transferred with OBD_BRW_SRVLOCK.
376 * lru page list. ops_inflight and ops_lru are exclusive so
377 * that they can share the same data.
381 * Linkage into a per-osc_object list of pages in flight. For
384 cfs_list_t ops_inflight;
387 * Thread that submitted this page for transfer. For debugging.
389 cfs_task_t *ops_submitter;
391 * Submit time - the time when the page is starting RPC. For debugging.
393 cfs_time_t ops_submit_time;
396 * A lock of which we hold a reference covers this page. Only used by
397 * read-ahead: for a readahead page, we hold it's covering lock to
398 * prevent it from being canceled during recovery.
400 * \see osc_lock::ols_pageref
401 * \see osc_page_addref_lock(), osc_page_putref_lock().
403 struct cl_lock *ops_lock;
406 extern struct kmem_cache *osc_lock_kmem;
407 extern struct kmem_cache *osc_object_kmem;
408 extern struct kmem_cache *osc_thread_kmem;
409 extern struct kmem_cache *osc_session_kmem;
410 extern struct kmem_cache *osc_req_kmem;
411 extern struct kmem_cache *osc_extent_kmem;
413 extern struct lu_device_type osc_device_type;
414 extern struct lu_context_key osc_key;
415 extern struct lu_context_key osc_session_key;
417 #define OSC_FLAGS (ASYNC_URGENT|ASYNC_READY)
419 int osc_lock_init(const struct lu_env *env,
420 struct cl_object *obj, struct cl_lock *lock,
421 const struct cl_io *io);
422 int osc_io_init (const struct lu_env *env,
423 struct cl_object *obj, struct cl_io *io);
424 int osc_req_init (const struct lu_env *env, struct cl_device *dev,
426 struct lu_object *osc_object_alloc(const struct lu_env *env,
427 const struct lu_object_header *hdr,
428 struct lu_device *dev);
429 int osc_page_init(const struct lu_env *env, struct cl_object *obj,
430 struct cl_page *page, struct page *vmpage);
432 void osc_index2policy (ldlm_policy_data_t *policy, const struct cl_object *obj,
433 pgoff_t start, pgoff_t end);
434 int osc_lvb_print (const struct lu_env *env, void *cookie,
435 lu_printer_t p, const struct ost_lvb *lvb);
437 void osc_page_submit(const struct lu_env *env, struct osc_page *opg,
438 enum cl_req_type crt, int brw_flags);
439 int osc_cancel_async_page(const struct lu_env *env, struct osc_page *ops);
440 int osc_set_async_flags(struct osc_object *obj, struct osc_page *opg,
441 obd_flag async_flags);
442 int osc_prep_async_page(struct osc_object *osc, struct osc_page *ops,
443 struct page *page, loff_t offset);
444 int osc_queue_async_io(const struct lu_env *env, struct cl_io *io,
445 struct osc_page *ops);
446 int osc_teardown_async_page(const struct lu_env *env, struct osc_object *obj,
447 struct osc_page *ops);
448 int osc_flush_async_page(const struct lu_env *env, struct cl_io *io,
449 struct osc_page *ops);
450 int osc_queue_sync_pages(const struct lu_env *env, struct osc_object *obj,
451 cfs_list_t *list, int cmd, int brw_flags);
452 int osc_cache_truncate_start(const struct lu_env *env, struct osc_io *oio,
453 struct osc_object *obj, __u64 size);
454 void osc_cache_truncate_end(const struct lu_env *env, struct osc_io *oio,
455 struct osc_object *obj);
456 int osc_cache_writeback_range(const struct lu_env *env, struct osc_object *obj,
457 pgoff_t start, pgoff_t end, int hp, int discard);
458 int osc_cache_wait_range(const struct lu_env *env, struct osc_object *obj,
459 pgoff_t start, pgoff_t end);
460 void osc_io_unplug(const struct lu_env *env, struct client_obd *cli,
461 struct osc_object *osc, pdl_policy_t pol);
463 void osc_object_set_contended (struct osc_object *obj);
464 void osc_object_clear_contended(struct osc_object *obj);
465 int osc_object_is_contended (struct osc_object *obj);
467 int osc_lock_is_lockless (const struct osc_lock *olck);
469 /*****************************************************************************
475 static inline struct osc_thread_info *osc_env_info(const struct lu_env *env)
477 struct osc_thread_info *info;
479 info = lu_context_key_get(&env->le_ctx, &osc_key);
480 LASSERT(info != NULL);
484 static inline struct osc_session *osc_env_session(const struct lu_env *env)
486 struct osc_session *ses;
488 ses = lu_context_key_get(env->le_ses, &osc_session_key);
489 LASSERT(ses != NULL);
493 static inline struct osc_io *osc_env_io(const struct lu_env *env)
495 return &osc_env_session(env)->os_io;
498 static inline int osc_is_object(const struct lu_object *obj)
500 return obj->lo_dev->ld_type == &osc_device_type;
503 static inline struct osc_device *lu2osc_dev(const struct lu_device *d)
505 LINVRNT(d->ld_type == &osc_device_type);
506 return container_of0(d, struct osc_device, od_cl.cd_lu_dev);
509 static inline struct obd_export *osc_export(const struct osc_object *obj)
511 return lu2osc_dev(obj->oo_cl.co_lu.lo_dev)->od_exp;
514 static inline struct client_obd *osc_cli(const struct osc_object *obj)
516 return &osc_export(obj)->exp_obd->u.cli;
519 static inline struct osc_object *cl2osc(const struct cl_object *obj)
521 LINVRNT(osc_is_object(&obj->co_lu));
522 return container_of0(obj, struct osc_object, oo_cl);
525 static inline struct cl_object *osc2cl(const struct osc_object *obj)
527 return (struct cl_object *)&obj->oo_cl;
530 static inline ldlm_mode_t osc_cl_lock2ldlm(enum cl_lock_mode mode)
532 LASSERT(mode == CLM_READ || mode == CLM_WRITE || mode == CLM_GROUP);
533 if (mode == CLM_READ)
535 else if (mode == CLM_WRITE)
541 static inline enum cl_lock_mode osc_ldlm2cl_lock(ldlm_mode_t mode)
543 LASSERT(mode == LCK_PR || mode == LCK_PW || mode == LCK_GROUP);
546 else if (mode == LCK_PW)
552 static inline struct osc_page *cl2osc_page(const struct cl_page_slice *slice)
554 LINVRNT(osc_is_object(&slice->cpl_obj->co_lu));
555 return container_of0(slice, struct osc_page, ops_cl);
558 static inline struct osc_page *oap2osc(struct osc_async_page *oap)
560 return container_of0(oap, struct osc_page, ops_oap);
563 static inline struct cl_page *oap2cl_page(struct osc_async_page *oap)
565 return oap2osc(oap)->ops_cl.cpl_page;
568 static inline struct osc_page *oap2osc_page(struct osc_async_page *oap)
570 return (struct osc_page *)container_of(oap, struct osc_page, ops_oap);
573 static inline struct osc_lock *cl2osc_lock(const struct cl_lock_slice *slice)
575 LINVRNT(osc_is_object(&slice->cls_obj->co_lu));
576 return container_of0(slice, struct osc_lock, ols_cl);
579 static inline struct osc_lock *osc_lock_at(const struct cl_lock *lock)
581 return cl2osc_lock(cl_lock_at(lock, &osc_device_type));
584 static inline int osc_io_srvlock(struct osc_io *oio)
586 return (oio->oi_lockless && !oio->oi_cl.cis_io->ci_no_srvlock);
589 enum osc_extent_state {
590 OES_INV = 0, /** extent is just initialized or destroyed */
591 OES_ACTIVE = 1, /** process is using this extent */
592 OES_CACHE = 2, /** extent is ready for IO */
593 OES_LOCKING = 3, /** locking page to prepare IO */
594 OES_LOCK_DONE = 4, /** locking finished, ready to send */
595 OES_RPC = 5, /** in RPC */
596 OES_TRUNC = 6, /** being truncated */
601 * osc_extent data to manage dirty pages.
602 * osc_extent has the following attributes:
603 * 1. all pages in the same must be in one RPC in write back;
604 * 2. # of pages must be less than max_pages_per_rpc - implied by 1;
605 * 3. must be covered by only 1 osc_lock;
606 * 4. exclusive. It's impossible to have overlapped osc_extent.
608 * The lifetime of an extent is from when the 1st page is dirtied to when
609 * all pages inside it are written out.
613 * page lock -> client_obd_list_lock -> object lock(osc_object::oo_lock)
616 /** red-black tree node */
617 struct rb_node oe_node;
618 /** osc_object of this extent */
619 struct osc_object *oe_obj;
620 /** refcount, removed from red-black tree if reaches zero. */
621 cfs_atomic_t oe_refc;
622 /** busy if non-zero */
623 cfs_atomic_t oe_users;
624 /** link list of osc_object's oo_{hp|urgent|locking}_exts. */
626 /** state of this extent */
627 unsigned int oe_state;
628 /** flags for this extent. */
629 unsigned int oe_intree:1,
630 /** 0 is write, 1 is read */
634 /** an ACTIVE extent is going to be truncated, so when this extent
635 * is released, it will turn into TRUNC state instead of CACHE. */
637 /** this extent should be written asap and someone may wait for the
638 * write to finish. This bit is usually set along with urgent if
639 * the extent was CACHE state.
640 * fsync_wait extent can't be merged because new extent region may
641 * exceed fsync range. */
643 /** covering lock is being canceled */
645 /** this extent should be written back asap. set if one of pages is
646 * called by page WB daemon, or sync write or reading requests. */
648 /** how many grants allocated for this extent.
649 * Grant allocated for this extent. There is no grant allocated
650 * for reading extents and sync write extents. */
651 unsigned int oe_grants;
652 /** # of dirty pages in this extent */
653 unsigned int oe_nr_pages;
654 /** list of pending oap pages. Pages in this list are NOT sorted. */
656 /** Since an extent has to be written out in atomic, this is used to
657 * remember the next page need to be locked to write this extent out.
658 * Not used right now.
660 struct osc_page *oe_next_page;
661 /** start and end index of this extent, include start and end
662 * themselves. Page offset here is the page index of osc_pages.
663 * oe_start is used as keyword for red-black tree. */
666 /** maximum ending index of this extent, this is limited by
667 * max_pages_per_rpc, lock extent and chunk size. */
669 /** waitqueue - for those who want to be notified if this extent's
670 * state has changed. */
671 cfs_waitq_t oe_waitq;
672 /** lock covering this extent */
673 struct cl_lock *oe_osclock;
674 /** terminator of this extent. Must be true if this extent is in IO. */
675 cfs_task_t *oe_owner;
676 /** return value of writeback. If somebody is waiting for this extent,
677 * this value can be known by outside world. */
679 /** max pages per rpc when this extent was created */
680 unsigned int oe_mppr;
683 int osc_extent_finish(const struct lu_env *env, struct osc_extent *ext,
685 int osc_extent_release(const struct lu_env *env, struct osc_extent *ext);
689 #endif /* OSC_CL_INTERNAL_H */