1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
2 * vim:expandtab:shiftwidth=8:tabstop=8:
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15 * General Public License version 2 for more details (a copy is included
16 * in the LICENSE file that accompanied this code).
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29 * Copyright 2008 Sun Microsystems, Inc. All rights reserved
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33 * This file is part of Lustre, http://www.lustre.org/
34 * Lustre is a trademark of Sun Microsystems, Inc.
37 #ifndef __LUSTRE_DT_OBJECT_H
38 #define __LUSTRE_DT_OBJECT_H
41 * Sub-class of lu_object with methods common for "data" objects in OST stack.
43 * Data objects behave like regular files: you can read/write them, get and
44 * set their attributes. Implementation of dt interface is supposed to
45 * implement some form of garbage collection, normally reference counting
48 * Examples: osd (lustre/osd) is an implementation of dt interface.
54 * super-class definitions.
56 #include <lu_object.h>
58 #include <libcfs/libcfs.h>
61 struct proc_dir_entry;
68 struct dt_index_features;
71 struct dt_device_param {
72 unsigned ddp_max_name_len;
73 unsigned ddp_max_nlink;
74 unsigned ddp_block_shift;
78 * Basic transaction credit op
88 DTO_LOG_REC, /**< XXX temporary: dt layer knows nothing about llog. */
97 * Operations on dt device.
99 struct dt_device_operations {
101 * Return device-wide statistics.
103 int (*dt_statfs)(const struct lu_env *env,
104 struct dt_device *dev, struct kstatfs *sfs);
106 * Start transaction, described by \a param.
108 struct thandle *(*dt_trans_start)(const struct lu_env *env,
109 struct dt_device *dev,
110 struct txn_param *param);
112 * Finish previously started transaction.
114 void (*dt_trans_stop)(const struct lu_env *env,
117 * Return fid of root index object.
119 int (*dt_root_get)(const struct lu_env *env,
120 struct dt_device *dev, struct lu_fid *f);
122 * Return device configuration data.
124 void (*dt_conf_get)(const struct lu_env *env,
125 const struct dt_device *dev,
126 struct dt_device_param *param);
128 * handling device state, mostly for tests
130 int (*dt_sync)(const struct lu_env *env, struct dt_device *dev);
131 void (*dt_ro)(const struct lu_env *env, struct dt_device *dev);
133 * Start a transaction commit asynchronously
135 * \param env environment
136 * \param dev dt_device to start commit on
138 * \return 0 success, negative value if error
140 int (*dt_commit_async)(const struct lu_env *env,
141 struct dt_device *dev);
143 * Initialize capability context.
145 int (*dt_init_capa_ctxt)(const struct lu_env *env,
146 struct dt_device *dev,
147 int mode, unsigned long timeout,
148 __u32 alg, struct lustre_capa_key *keys);
150 * Initialize quota context.
152 void (*dt_init_quota_ctxt)(const struct lu_env *env,
153 struct dt_device *dev,
154 struct dt_quota_ctxt *ctxt, void *data);
157 * get transaction credits for given \a op.
159 int (*dt_credit_get)(const struct lu_env *env, struct dt_device *dev,
163 struct dt_index_features {
164 /** required feature flags from enum dt_index_flags */
166 /** minimal required key size */
167 size_t dif_keysize_min;
168 /** maximal required key size, 0 if no limit */
169 size_t dif_keysize_max;
170 /** minimal required record size */
171 size_t dif_recsize_min;
172 /** maximal required record size, 0 if no limit */
173 size_t dif_recsize_max;
174 /** pointer size for record */
178 enum dt_index_flags {
179 /** index supports variable sized keys */
180 DT_IND_VARKEY = 1 << 0,
181 /** index supports variable sized records */
182 DT_IND_VARREC = 1 << 1,
183 /** index can be modified */
184 DT_IND_UPDATE = 1 << 2,
185 /** index supports records with non-unique (duplicate) keys */
186 DT_IND_NONUNQ = 1 << 3
190 * Features, required from index to support file system directories (mapping
193 extern const struct dt_index_features dt_directory_features;
196 * This is a general purpose dt allocation hint.
197 * It now contains the parent object.
198 * It can contain any allocation hint in the future.
200 struct dt_allocation_hint {
201 struct dt_object *dah_parent;
206 * object type specifier.
209 enum dt_format_type {
214 /** for special index */
216 /** for symbolic link */
221 * object format specifier.
223 struct dt_object_format {
224 /** type for dt object */
225 enum dt_format_type dof_type;
234 * special index need feature as parameter to create
238 const struct dt_index_features *di_feat;
243 enum dt_format_type dt_mode_to_dft(__u32 mode);
246 * Per-dt-object operations.
248 struct dt_object_operations {
249 void (*do_read_lock)(const struct lu_env *env,
250 struct dt_object *dt, unsigned role);
251 void (*do_write_lock)(const struct lu_env *env,
252 struct dt_object *dt, unsigned role);
253 void (*do_read_unlock)(const struct lu_env *env,
254 struct dt_object *dt);
255 void (*do_write_unlock)(const struct lu_env *env,
256 struct dt_object *dt);
258 * Note: following ->do_{x,}attr_{set,get}() operations are very
259 * similar to ->moo_{x,}attr_{set,get}() operations in struct
260 * md_object_operations (see md_object.h). These operations are not in
261 * lu_object_operations, because ->do_{x,}attr_set() versions take
262 * transaction handle as an argument (this transaction is started by
263 * caller). We might factor ->do_{x,}attr_get() into
264 * lu_object_operations, but that would break existing symmetry.
268 * Return standard attributes.
270 * precondition: lu_object_exists(&dt->do_lu);
272 int (*do_attr_get)(const struct lu_env *env,
273 struct dt_object *dt, struct lu_attr *attr,
274 struct lustre_capa *capa);
276 * Set standard attributes.
278 * precondition: dt_object_exists(dt);
280 int (*do_attr_set)(const struct lu_env *env,
281 struct dt_object *dt,
282 const struct lu_attr *attr,
283 struct thandle *handle,
284 struct lustre_capa *capa);
286 * Return a value of an extended attribute.
288 * precondition: dt_object_exists(dt);
290 int (*do_xattr_get)(const struct lu_env *env, struct dt_object *dt,
291 struct lu_buf *buf, const char *name,
292 struct lustre_capa *capa);
294 * Set value of an extended attribute.
296 * \a fl - flags from enum lu_xattr_flags
298 * precondition: dt_object_exists(dt);
300 int (*do_xattr_set)(const struct lu_env *env,
301 struct dt_object *dt, const struct lu_buf *buf,
302 const char *name, int fl, struct thandle *handle,
303 struct lustre_capa *capa);
305 * Delete existing extended attribute.
307 * precondition: dt_object_exists(dt);
309 int (*do_xattr_del)(const struct lu_env *env,
310 struct dt_object *dt,
311 const char *name, struct thandle *handle,
312 struct lustre_capa *capa);
314 * Place list of existing extended attributes into \a buf (which has
317 * precondition: dt_object_exists(dt);
319 int (*do_xattr_list)(const struct lu_env *env,
320 struct dt_object *dt, struct lu_buf *buf,
321 struct lustre_capa *capa);
323 * Init allocation hint using parent object and child mode.
324 * (1) The \a parent might be NULL if this is a partial creation for
326 * (2) The type of child is in \a child_mode.
327 * (3) The result hint is stored in \a ah;
329 void (*do_ah_init)(const struct lu_env *env,
330 struct dt_allocation_hint *ah,
331 struct dt_object *parent,
334 * Create new object on this device.
336 * precondition: !dt_object_exists(dt);
337 * postcondition: ergo(result == 0, dt_object_exists(dt));
339 int (*do_create)(const struct lu_env *env, struct dt_object *dt,
340 struct lu_attr *attr,
341 struct dt_allocation_hint *hint,
342 struct dt_object_format *dof,
346 * Announce that this object is going to be used as an index. This
347 * operation check that object supports indexing operations and
348 * installs appropriate dt_index_operations vector on success.
350 * Also probes for features. Operation is successful if all required
351 * features are supported.
353 int (*do_index_try)(const struct lu_env *env,
354 struct dt_object *dt,
355 const struct dt_index_features *feat);
357 * Add nlink of the object
358 * precondition: dt_object_exists(dt);
360 void (*do_ref_add)(const struct lu_env *env,
361 struct dt_object *dt, struct thandle *th);
363 * Del nlink of the object
364 * precondition: dt_object_exists(dt);
366 void (*do_ref_del)(const struct lu_env *env,
367 struct dt_object *dt, struct thandle *th);
369 struct obd_capa *(*do_capa_get)(const struct lu_env *env,
370 struct dt_object *dt,
371 struct lustre_capa *old,
373 int (*do_object_sync)(const struct lu_env *, struct dt_object *);
377 * Per-dt-object operations on "file body".
379 struct dt_body_operations {
381 * precondition: dt_object_exists(dt);
383 ssize_t (*dbo_read)(const struct lu_env *env, struct dt_object *dt,
384 struct lu_buf *buf, loff_t *pos,
385 struct lustre_capa *capa);
387 * precondition: dt_object_exists(dt);
389 ssize_t (*dbo_write)(const struct lu_env *env, struct dt_object *dt,
390 const struct lu_buf *buf, loff_t *pos,
391 struct thandle *handle, struct lustre_capa *capa,
396 * Incomplete type of index record.
401 * Incomplete type of index key.
406 * Incomplete type of dt iterator.
411 * Per-dt-object operations on object as index.
413 struct dt_index_operations {
415 * precondition: dt_object_exists(dt);
417 int (*dio_lookup)(const struct lu_env *env, struct dt_object *dt,
418 struct dt_rec *rec, const struct dt_key *key,
419 struct lustre_capa *capa);
421 * precondition: dt_object_exists(dt);
423 int (*dio_insert)(const struct lu_env *env, struct dt_object *dt,
424 const struct dt_rec *rec, const struct dt_key *key,
425 struct thandle *handle, struct lustre_capa *capa,
428 * precondition: dt_object_exists(dt);
430 int (*dio_delete)(const struct lu_env *env, struct dt_object *dt,
431 const struct dt_key *key, struct thandle *handle,
432 struct lustre_capa *capa);
438 * Allocate and initialize new iterator.
440 * precondition: dt_object_exists(dt);
442 struct dt_it *(*init)(const struct lu_env *env,
443 struct dt_object *dt,
444 struct lustre_capa *capa);
445 void (*fini)(const struct lu_env *env,
447 int (*get)(const struct lu_env *env,
449 const struct dt_key *key);
450 void (*put)(const struct lu_env *env,
452 int (*next)(const struct lu_env *env,
454 struct dt_key *(*key)(const struct lu_env *env,
455 const struct dt_it *di);
456 int (*key_size)(const struct lu_env *env,
457 const struct dt_it *di);
458 struct dt_rec *(*rec)(const struct lu_env *env,
459 const struct dt_it *di);
460 __u64 (*store)(const struct lu_env *env,
461 const struct dt_it *di);
462 int (*load)(const struct lu_env *env,
463 const struct dt_it *di, __u64 hash);
468 struct lu_device dd_lu_dev;
469 const struct dt_device_operations *dd_ops;
472 * List of dt_txn_callback (see below). This is not protected in any
473 * way, because callbacks are supposed to be added/deleted only during
474 * single-threaded start-up shut-down procedures.
476 struct list_head dd_txn_callbacks;
479 int dt_device_init(struct dt_device *dev, struct lu_device_type *t);
480 void dt_device_fini(struct dt_device *dev);
482 static inline int lu_device_is_dt(const struct lu_device *d)
484 return ergo(d != NULL, d->ld_type->ldt_tags & LU_DEVICE_DT);
487 static inline struct dt_device * lu2dt_dev(struct lu_device *l)
489 LASSERT(lu_device_is_dt(l));
490 return container_of0(l, struct dt_device, dd_lu_dev);
494 struct lu_object do_lu;
495 const struct dt_object_operations *do_ops;
496 const struct dt_body_operations *do_body_ops;
497 const struct dt_index_operations *do_index_ops;
500 int dt_object_init(struct dt_object *obj,
501 struct lu_object_header *h, struct lu_device *d);
503 void dt_object_fini(struct dt_object *obj);
505 static inline int dt_object_exists(const struct dt_object *dt)
507 return lu_object_exists(&dt->do_lu);
511 /** number of blocks this transaction will modify */
512 unsigned int tp_credits;
513 /** sync transaction is needed */
517 static inline void txn_param_init(struct txn_param *p, unsigned int credits)
519 memset(p, 0, sizeof(*p));
520 p->tp_credits = credits;
524 * This is the general purpose transaction handle.
525 * 1. Transaction Life Cycle
526 * This transaction handle is allocated upon starting a new transaction,
527 * and deallocated after this transaction is committed.
528 * 2. Transaction Nesting
529 * We do _NOT_ support nested transaction. So, every thread should only
530 * have one active transaction, and a transaction only belongs to one
531 * thread. Due to this, transaction handle need no reference count.
532 * 3. Transaction & dt_object locking
533 * dt_object locks should be taken inside transaction.
534 * 4. Transaction & RPC
535 * No RPC request should be issued inside transaction.
538 /** the dt device on which the transactions are executed */
539 struct dt_device *th_dev;
541 /** context for this transaction, tag is LCT_TX_HANDLE */
542 struct lu_context th_ctx;
544 /** the last operation result in this transaction.
545 * this value is used in recovery */
550 * Transaction call-backs.
552 * These are invoked by osd (or underlying transaction engine) when
553 * transaction changes state.
555 * Call-backs are used by upper layers to modify transaction parameters and to
556 * perform some actions on for each transaction state transition. Typical
557 * example is mdt registering call-back to write into last-received file
558 * before each transaction commit.
560 struct dt_txn_callback {
561 int (*dtc_txn_start)(const struct lu_env *env,
562 struct txn_param *param, void *cookie);
563 int (*dtc_txn_stop)(const struct lu_env *env,
564 struct thandle *txn, void *cookie);
565 int (*dtc_txn_commit)(const struct lu_env *env,
566 struct thandle *txn, void *cookie);
568 struct list_head dtc_linkage;
571 void dt_txn_callback_add(struct dt_device *dev, struct dt_txn_callback *cb);
572 void dt_txn_callback_del(struct dt_device *dev, struct dt_txn_callback *cb);
574 int dt_txn_hook_start(const struct lu_env *env,
575 struct dt_device *dev, struct txn_param *param);
576 int dt_txn_hook_stop(const struct lu_env *env, struct thandle *txn);
577 int dt_txn_hook_commit(const struct lu_env *env, struct thandle *txn);
579 int dt_try_as_dir(const struct lu_env *env, struct dt_object *obj);
582 * Callback function used for parsing path.
583 * \see llo_store_resolve
585 typedef int (*dt_entry_func_t)(const struct lu_env *env,
589 #define DT_MAX_PATH 1024
591 int dt_path_parser(const struct lu_env *env,
592 char *local, dt_entry_func_t entry_func,
595 struct dt_object *dt_store_open(const struct lu_env *env,
596 struct dt_device *dt,
598 const char *filename,
601 struct dt_object *dt_locate(const struct lu_env *env,
602 struct dt_device *dev,
603 const struct lu_fid *fid);
606 #endif /* __LUSTRE_DT_OBJECT_H */