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Diffstat (limited to 'drivers/staging/lustre/lustre/include/lu_object.h')
| -rw-r--r-- | drivers/staging/lustre/lustre/include/lu_object.h | 1346 |
1 files changed, 1346 insertions, 0 deletions
diff --git a/drivers/staging/lustre/lustre/include/lu_object.h b/drivers/staging/lustre/lustre/include/lu_object.h new file mode 100644 index 000000000000..d40ad81b4eb2 --- /dev/null +++ b/drivers/staging/lustre/lustre/include/lu_object.h @@ -0,0 +1,1346 @@ +/* + * 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) 2007, 2010, Oracle and/or its affiliates. All rights reserved. + * Use is subject to license terms. + * + * Copyright (c) 2011, 2012, Intel Corporation. + */ +/* + * This file is part of Lustre, http://www.lustre.org/ + * Lustre is a trademark of Sun Microsystems, Inc. + */ + +#ifndef __LUSTRE_LU_OBJECT_H +#define __LUSTRE_LU_OBJECT_H + +#include <stdarg.h> +#include <linux/libcfs/libcfs.h> +#include <lustre/lustre_idl.h> +#include <lu_ref.h> + +struct seq_file; +struct proc_dir_entry; +struct lustre_cfg; +struct lprocfs_stats; + +/** \defgroup lu lu + * lu_* data-types represent server-side entities shared by data and meta-data + * stacks. + * + * Design goals: + * + * -# support for layering. + * + * Server side object is split into layers, one per device in the + * corresponding device stack. Individual layer is represented by struct + * lu_object. Compound layered object --- by struct lu_object_header. Most + * interface functions take lu_object as an argument and operate on the + * whole compound object. This decision was made due to the following + * reasons: + * + * - it's envisaged that lu_object will be used much more often than + * lu_object_header; + * + * - we want lower (non-top) layers to be able to initiate operations + * on the whole object. + * + * Generic code supports layering more complex than simple stacking, e.g., + * it is possible that at some layer object "spawns" multiple sub-objects + * on the lower layer. + * + * -# fid-based identification. + * + * Compound object is uniquely identified by its fid. Objects are indexed + * by their fids (hash table is used for index). + * + * -# caching and life-cycle management. + * + * Object's life-time is controlled by reference counting. When reference + * count drops to 0, object is returned to cache. Cached objects still + * retain their identity (i.e., fid), and can be recovered from cache. + * + * Objects are kept in the global LRU list, and lu_site_purge() function + * can be used to reclaim given number of unused objects from the tail of + * the LRU. + * + * -# avoiding recursion. + * + * Generic code tries to replace recursion through layers by iterations + * where possible. Additionally to the end of reducing stack consumption, + * data, when practically possible, are allocated through lu_context_key + * interface rather than on stack. + * @{ + */ + +struct lu_site; +struct lu_object; +struct lu_device; +struct lu_object_header; +struct lu_context; +struct lu_env; + +/** + * Operations common for data and meta-data devices. + */ +struct lu_device_operations { + /** + * Allocate object for the given device (without lower-layer + * parts). This is called by lu_object_operations::loo_object_init() + * from the parent layer, and should setup at least lu_object::lo_dev + * and lu_object::lo_ops fields of resulting lu_object. + * + * Object creation protocol. + * + * Due to design goal of avoiding recursion, object creation (see + * lu_object_alloc()) is somewhat involved: + * + * - first, lu_device_operations::ldo_object_alloc() method of the + * top-level device in the stack is called. It should allocate top + * level object (including lu_object_header), but without any + * lower-layer sub-object(s). + * + * - then lu_object_alloc() sets fid in the header of newly created + * object. + * + * - then lu_object_operations::loo_object_init() is called. It has + * to allocate lower-layer object(s). To do this, + * lu_object_operations::loo_object_init() calls ldo_object_alloc() + * of the lower-layer device(s). + * + * - for all new objects allocated by + * lu_object_operations::loo_object_init() (and inserted into object + * stack), lu_object_operations::loo_object_init() is called again + * repeatedly, until no new objects are created. + * + * \post ergo(!IS_ERR(result), result->lo_dev == d && + * result->lo_ops != NULL); + */ + struct lu_object *(*ldo_object_alloc)(const struct lu_env *env, + const struct lu_object_header *h, + struct lu_device *d); + /** + * process config specific for device. + */ + int (*ldo_process_config)(const struct lu_env *env, + struct lu_device *, struct lustre_cfg *); + int (*ldo_recovery_complete)(const struct lu_env *, + struct lu_device *); + + /** + * initialize local objects for device. this method called after layer has + * been initialized (after LCFG_SETUP stage) and before it starts serving + * user requests. + */ + + int (*ldo_prepare)(const struct lu_env *, + struct lu_device *parent, + struct lu_device *dev); + +}; + +/** + * For lu_object_conf flags + */ +typedef enum { + /* This is a new object to be allocated, or the file + * corresponding to the object does not exists. */ + LOC_F_NEW = 0x00000001, +} loc_flags_t; + +/** + * Object configuration, describing particulars of object being created. On + * server this is not used, as server objects are full identified by fid. On + * client configuration contains struct lustre_md. + */ +struct lu_object_conf { + /** + * Some hints for obj find and alloc. + */ + loc_flags_t loc_flags; +}; + +/** + * Type of "printer" function used by lu_object_operations::loo_object_print() + * method. + * + * Printer function is needed to provide some flexibility in (semi-)debugging + * output: possible implementations: printk, CDEBUG, sysfs/seq_file + */ +typedef int (*lu_printer_t)(const struct lu_env *env, + void *cookie, const char *format, ...) + __attribute__ ((format (printf, 3, 4))); + +/** + * Operations specific for particular lu_object. + */ +struct lu_object_operations { + + /** + * Allocate lower-layer parts of the object by calling + * lu_device_operations::ldo_object_alloc() of the corresponding + * underlying device. + * + * This method is called once for each object inserted into object + * stack. It's responsibility of this method to insert lower-layer + * object(s) it create into appropriate places of object stack. + */ + int (*loo_object_init)(const struct lu_env *env, + struct lu_object *o, + const struct lu_object_conf *conf); + /** + * Called (in top-to-bottom order) during object allocation after all + * layers were allocated and initialized. Can be used to perform + * initialization depending on lower layers. + */ + int (*loo_object_start)(const struct lu_env *env, + struct lu_object *o); + /** + * Called before lu_object_operations::loo_object_free() to signal + * that object is being destroyed. Dual to + * lu_object_operations::loo_object_init(). + */ + void (*loo_object_delete)(const struct lu_env *env, + struct lu_object *o); + /** + * Dual to lu_device_operations::ldo_object_alloc(). Called when + * object is removed from memory. + */ + void (*loo_object_free)(const struct lu_env *env, + struct lu_object *o); + /** + * Called when last active reference to the object is released (and + * object returns to the cache). This method is optional. + */ + void (*loo_object_release)(const struct lu_env *env, + struct lu_object *o); + /** + * Optional debugging helper. Print given object. + */ + int (*loo_object_print)(const struct lu_env *env, void *cookie, + lu_printer_t p, const struct lu_object *o); + /** + * Optional debugging method. Returns true iff method is internally + * consistent. + */ + int (*loo_object_invariant)(const struct lu_object *o); +}; + +/** + * Type of lu_device. + */ +struct lu_device_type; + +/** + * Device: a layer in the server side abstraction stacking. + */ +struct lu_device { + /** + * reference count. This is incremented, in particular, on each object + * created at this layer. + * + * \todo XXX which means that atomic_t is probably too small. + */ + atomic_t ld_ref; + /** + * Pointer to device type. Never modified once set. + */ + struct lu_device_type *ld_type; + /** + * Operation vector for this device. + */ + const struct lu_device_operations *ld_ops; + /** + * Stack this device belongs to. + */ + struct lu_site *ld_site; + struct proc_dir_entry *ld_proc_entry; + + /** \todo XXX: temporary back pointer into obd. */ + struct obd_device *ld_obd; + /** + * A list of references to this object, for debugging. + */ + struct lu_ref ld_reference; + /** + * Link the device to the site. + **/ + struct list_head ld_linkage; +}; + +struct lu_device_type_operations; + +/** + * Tag bits for device type. They are used to distinguish certain groups of + * device types. + */ +enum lu_device_tag { + /** this is meta-data device */ + LU_DEVICE_MD = (1 << 0), + /** this is data device */ + LU_DEVICE_DT = (1 << 1), + /** data device in the client stack */ + LU_DEVICE_CL = (1 << 2) +}; + +/** + * Type of device. + */ +struct lu_device_type { + /** + * Tag bits. Taken from enum lu_device_tag. Never modified once set. + */ + __u32 ldt_tags; + /** + * Name of this class. Unique system-wide. Never modified once set. + */ + char *ldt_name; + /** + * Operations for this type. + */ + const struct lu_device_type_operations *ldt_ops; + /** + * \todo XXX: temporary pointer to associated obd_type. + */ + struct obd_type *ldt_obd_type; + /** + * \todo XXX: temporary: context tags used by obd_*() calls. + */ + __u32 ldt_ctx_tags; + /** + * Number of existing device type instances. + */ + unsigned ldt_device_nr; + /** + * Linkage into a global list of all device types. + * + * \see lu_device_types. + */ + struct list_head ldt_linkage; +}; + +/** + * Operations on a device type. + */ +struct lu_device_type_operations { + /** + * Allocate new device. + */ + struct lu_device *(*ldto_device_alloc)(const struct lu_env *env, + struct lu_device_type *t, + struct lustre_cfg *lcfg); + /** + * Free device. Dual to + * lu_device_type_operations::ldto_device_alloc(). Returns pointer to + * the next device in the stack. + */ + struct lu_device *(*ldto_device_free)(const struct lu_env *, + struct lu_device *); + + /** + * Initialize the devices after allocation + */ + int (*ldto_device_init)(const struct lu_env *env, + struct lu_device *, const char *, + struct lu_device *); + /** + * Finalize device. Dual to + * lu_device_type_operations::ldto_device_init(). Returns pointer to + * the next device in the stack. + */ + struct lu_device *(*ldto_device_fini)(const struct lu_env *env, + struct lu_device *); + /** + * Initialize device type. This is called on module load. + */ + int (*ldto_init)(struct lu_device_type *t); + /** + * Finalize device type. Dual to + * lu_device_type_operations::ldto_init(). Called on module unload. + */ + void (*ldto_fini)(struct lu_device_type *t); + /** + * Called when the first device is created. + */ + void (*ldto_start)(struct lu_device_type *t); + /** + * Called when number of devices drops to 0. + */ + void (*ldto_stop)(struct lu_device_type *t); +}; + +static inline int lu_device_is_md(const struct lu_device *d) +{ + return ergo(d != NULL, d->ld_type->ldt_tags & LU_DEVICE_MD); +} + +/** + * Flags for the object layers. + */ +enum lu_object_flags { + /** + * this flags is set if lu_object_operations::loo_object_init() has + * been called for this layer. Used by lu_object_alloc(). + */ + LU_OBJECT_ALLOCATED = (1 << 0) +}; + +/** + * Common object attributes. + */ +struct lu_attr { + /** size in bytes */ + __u64 la_size; + /** modification time in seconds since Epoch */ + obd_time la_mtime; + /** access time in seconds since Epoch */ + obd_time la_atime; + /** change time in seconds since Epoch */ + obd_time la_ctime; + /** 512-byte blocks allocated to object */ + __u64 la_blocks; + /** permission bits and file type */ + __u32 la_mode; + /** owner id */ + __u32 la_uid; + /** group id */ + __u32 la_gid; + /** object flags */ + __u32 la_flags; + /** number of persistent references to this object */ + __u32 la_nlink; + /** blk bits of the object*/ + __u32 la_blkbits; + /** blk size of the object*/ + __u32 la_blksize; + /** real device */ + __u32 la_rdev; + /** + * valid bits + * + * \see enum la_valid + */ + __u64 la_valid; +}; + +/** Bit-mask of valid attributes */ +enum la_valid { + LA_ATIME = 1 << 0, + LA_MTIME = 1 << 1, + LA_CTIME = 1 << 2, + LA_SIZE = 1 << 3, + LA_MODE = 1 << 4, + LA_UID = 1 << 5, + LA_GID = 1 << 6, + LA_BLOCKS = 1 << 7, + LA_TYPE = 1 << 8, + LA_FLAGS = 1 << 9, + LA_NLINK = 1 << 10, + LA_RDEV = 1 << 11, + LA_BLKSIZE = 1 << 12, + LA_KILL_SUID = 1 << 13, + LA_KILL_SGID = 1 << 14, +}; + +/** + * Layer in the layered object. + */ +struct lu_object { + /** + * Header for this object. + */ + struct lu_object_header *lo_header; + /** + * Device for this layer. + */ + struct lu_device *lo_dev; + /** + * Operations for this object. + */ + const struct lu_object_operations *lo_ops; + /** + * Linkage into list of all layers. + */ + struct list_head lo_linkage; + /** + * Depth. Top level layer depth is 0. + */ + int lo_depth; + /** + * Flags from enum lu_object_flags. + */ + __u32 lo_flags; + /** + * Link to the device, for debugging. + */ + struct lu_ref_link *lo_dev_ref; +}; + +enum lu_object_header_flags { + /** + * Don't keep this object in cache. Object will be destroyed as soon + * as last reference to it is released. This flag cannot be cleared + * once set. + */ + LU_OBJECT_HEARD_BANSHEE = 0, + /** + * Mark this object has already been taken out of cache. + */ + LU_OBJECT_UNHASHED = 1 +}; + +enum lu_object_header_attr { + LOHA_EXISTS = 1 << 0, + LOHA_REMOTE = 1 << 1, + /** + * UNIX file type is stored in S_IFMT bits. + */ + LOHA_FT_START = 001 << 12, /**< S_IFIFO */ + LOHA_FT_END = 017 << 12, /**< S_IFMT */ +}; + +/** + * "Compound" object, consisting of multiple layers. + * + * Compound object with given fid is unique with given lu_site. + * + * Note, that object does *not* necessary correspond to the real object in the + * persistent storage: object is an anchor for locking and method calling, so + * it is created for things like not-yet-existing child created by mkdir or + * create calls. lu_object_operations::loo_exists() can be used to check + * whether object is backed by persistent storage entity. + */ +struct lu_object_header { + /** + * Object flags from enum lu_object_header_flags. Set and checked + * atomically. + */ + unsigned long loh_flags; + /** + * Object reference count. Protected by lu_site::ls_guard. + */ + atomic_t loh_ref; + /** + * Fid, uniquely identifying this object. + */ + struct lu_fid loh_fid; + /** + * Common object attributes, cached for efficiency. From enum + * lu_object_header_attr. + */ + __u32 loh_attr; + /** + * Linkage into per-site hash table. Protected by lu_site::ls_guard. + */ + struct hlist_node loh_hash; + /** + * Linkage into per-site LRU list. Protected by lu_site::ls_guard. + */ + struct list_head loh_lru; + /** + * Linkage into list of layers. Never modified once set (except lately + * during object destruction). No locking is necessary. + */ + struct list_head loh_layers; + /** + * A list of references to this object, for debugging. + */ + struct lu_ref loh_reference; +}; + +struct fld; + +struct lu_site_bkt_data { + /** + * number of busy object on this bucket + */ + long lsb_busy; + /** + * LRU list, updated on each access to object. Protected by + * bucket lock of lu_site::ls_obj_hash. + * + * "Cold" end of LRU is lu_site::ls_lru.next. Accessed object are + * moved to the lu_site::ls_lru.prev (this is due to the non-existence + * of list_for_each_entry_safe_reverse()). + */ + struct list_head lsb_lru; + /** + * Wait-queue signaled when an object in this site is ultimately + * destroyed (lu_object_free()). It is used by lu_object_find() to + * wait before re-trying when object in the process of destruction is + * found in the hash table. + * + * \see htable_lookup(). + */ + wait_queue_head_t lsb_marche_funebre; +}; + +enum { + LU_SS_CREATED = 0, + LU_SS_CACHE_HIT, + LU_SS_CACHE_MISS, + LU_SS_CACHE_RACE, + LU_SS_CACHE_DEATH_RACE, + LU_SS_LRU_PURGED, + LU_SS_LAST_STAT +}; + +/** + * lu_site is a "compartment" within which objects are unique, and LRU + * discipline is maintained. + * + * lu_site exists so that multiple layered stacks can co-exist in the same + * address space. + * + * lu_site has the same relation to lu_device as lu_object_header to + * lu_object. + */ +struct lu_site { + /** + * objects hash table + */ + cfs_hash_t *ls_obj_hash; + /** + * index of bucket on hash table while purging + */ + int ls_purge_start; + /** + * Top-level device for this stack. + */ + struct lu_device *ls_top_dev; + /** + * Bottom-level device for this stack + */ + struct lu_device *ls_bottom_dev; + /** + * Linkage into global list of sites. + */ + struct list_head ls_linkage; + /** + * List for lu device for this site, protected + * by ls_ld_lock. + **/ + struct list_head ls_ld_linkage; + spinlock_t ls_ld_lock; + + /** + * lu_site stats + */ + struct lprocfs_stats *ls_stats; + /** + * XXX: a hack! fld has to find md_site via site, remove when possible + */ + struct seq_server_site *ld_seq_site; +}; + +static inline struct lu_site_bkt_data * +lu_site_bkt_from_fid(struct lu_site *site, struct lu_fid *fid) +{ + cfs_hash_bd_t bd; + + cfs_hash_bd_get(site->ls_obj_hash, fid, &bd); + return cfs_hash_bd_extra_get(site->ls_obj_hash, &bd); +} + +/** \name ctors + * Constructors/destructors. + * @{ + */ + +int lu_site_init (struct lu_site *s, struct lu_device *d); +void lu_site_fini (struct lu_site *s); +int lu_site_init_finish (struct lu_site *s); +void lu_stack_fini (const struct lu_env *env, struct lu_device *top); +void lu_device_get (struct lu_device *d); +void lu_device_put (struct lu_device *d); +int lu_device_init (struct lu_device *d, struct lu_device_type *t); +void lu_device_fini (struct lu_device *d); +int lu_object_header_init(struct lu_object_header *h); +void lu_object_header_fini(struct lu_object_header *h); +int lu_object_init (struct lu_object *o, + struct lu_object_header *h, struct lu_device *d); +void lu_object_fini (struct lu_object *o); +void lu_object_add_top (struct lu_object_header *h, struct lu_object *o); +void lu_object_add (struct lu_object *before, struct lu_object *o); + +void lu_dev_add_linkage(struct lu_site *s, struct lu_device *d); +void lu_dev_del_linkage(struct lu_site *s, struct lu_device *d); + +/** + * Helpers to initialize and finalize device types. + */ + +int lu_device_type_init(struct lu_device_type *ldt); +void lu_device_type_fini(struct lu_device_type *ldt); +void lu_types_stop(void); + +/** @} ctors */ + +/** \name caching + * Caching and reference counting. + * @{ + */ + +/** + * Acquire additional reference to the given object. This function is used to + * attain additional reference. To acquire initial reference use + * lu_object_find(). + */ +static inline void lu_object_get(struct lu_object *o) +{ + LASSERT(atomic_read(&o->lo_header->loh_ref) > 0); + atomic_inc(&o->lo_header->loh_ref); +} + +/** + * Return true of object will not be cached after last reference to it is + * released. + */ +static inline int lu_object_is_dying(const struct lu_object_header *h) +{ + return test_bit(LU_OBJECT_HEARD_BANSHEE, &h->loh_flags); +} + +void lu_object_put(const struct lu_env *env, struct lu_object *o); +void lu_object_put_nocache(const struct lu_env *env, struct lu_object *o); +void lu_object_unhash(const struct lu_env *env, struct lu_object *o); + +int lu_site_purge(const struct lu_env *env, struct lu_site *s, int nr); + +void lu_site_print(const struct lu_env *env, struct lu_site *s, void *cookie, + lu_printer_t printer); +struct lu_object *lu_object_find(const struct lu_env *env, + struct lu_device *dev, const struct lu_fid *f, + const struct lu_object_conf *conf); +struct lu_object *lu_object_find_at(const struct lu_env *env, + struct lu_device *dev, + const struct lu_fid *f, + const struct lu_object_conf *conf); +struct lu_object *lu_object_find_slice(const struct lu_env *env, + struct lu_device *dev, + const struct lu_fid *f, + const struct lu_object_conf *conf); +/** @} caching */ + +/** \name helpers + * Helpers. + * @{ + */ + +/** + * First (topmost) sub-object of given compound object + */ +static inline struct lu_object *lu_object_top(struct lu_object_header *h) +{ + LASSERT(!list_empty(&h->loh_layers)); + return container_of0(h->loh_layers.next, struct lu_object, lo_linkage); +} + +/** + * Next sub-object in the layering + */ +static inline struct lu_object *lu_object_next(const struct lu_object *o) +{ + return container_of0(o->lo_linkage.next, struct lu_object, lo_linkage); +} + +/** + * Pointer to the fid of this object. + */ +static inline const struct lu_fid *lu_object_fid(const struct lu_object *o) +{ + return &o->lo_header->loh_fid; +} + +/** + * return device operations vector for this object + */ +static const inline struct lu_device_operations * +lu_object_ops(const struct lu_object *o) +{ + return o->lo_dev->ld_ops; +} + +/** + * Given a compound object, find its slice, corresponding to the device type + * \a dtype. + */ +struct lu_object *lu_object_locate(struct lu_object_header *h, + const struct lu_device_type *dtype); + +/** + * Printer function emitting messages through libcfs_debug_msg(). + */ +int lu_cdebug_printer(const struct lu_env *env, + void *cookie, const char *format, ...); + +/** + * Print object description followed by a user-supplied message. + */ +#define LU_OBJECT_DEBUG(mask, env, object, format, ...) \ +do { \ + LIBCFS_DEBUG_MSG_DATA_DECL(msgdata, mask, NULL); \ + \ + if (cfs_cdebug_show(mask, DEBUG_SUBSYSTEM)) { \ + lu_object_print(env, &msgdata, lu_cdebug_printer, object);\ + CDEBUG(mask, format , ## __VA_ARGS__); \ + } \ +} while (0) + +/** + * Print short object description followed by a user-supplied message. + */ +#define LU_OBJECT_HEADER(mask, env, object, format, ...) \ +do { \ + LIBCFS_DEBUG_MSG_DATA_DECL(msgdata, mask, NULL); \ + \ + if (cfs_cdebug_show(mask, DEBUG_SUBSYSTEM)) { \ + lu_object_header_print(env, &msgdata, lu_cdebug_printer,\ + (object)->lo_header); \ + lu_cdebug_printer(env, &msgdata, "\n"); \ + CDEBUG(mask, format , ## __VA_ARGS__); \ + } \ +} while (0) + +void lu_object_print (const struct lu_env *env, void *cookie, + lu_printer_t printer, const struct lu_object *o); +void lu_object_header_print(const struct lu_env *env, void *cookie, + lu_printer_t printer, + const struct lu_object_header *hdr); + +/** + * Check object consistency. + */ +int lu_object_invariant(const struct lu_object *o); + + +/** + * Check whether object exists, no matter on local or remote storage. + * Note: LOHA_EXISTS will be set once some one created the object, + * and it does not needs to be committed to storage. + */ +#define lu_object_exists(o) ((o)->lo_header->loh_attr & LOHA_EXISTS) + +/** + * Check whether object on the remote storage. + */ +#define lu_object_remote(o) unlikely((o)->lo_header->loh_attr & LOHA_REMOTE) + +static inline int lu_object_assert_exists(const struct lu_object *o) +{ + return lu_object_exists(o); +} + +static inline int lu_object_assert_not_exists(const struct lu_object *o) +{ + return !lu_object_exists(o); +} + +/** + * Attr of this object. + */ +static inline __u32 lu_object_attr(const struct lu_object *o) +{ + LASSERT(lu_object_exists(o) != 0); + return o->lo_header->loh_attr; +} + +static inline struct lu_ref_link *lu_object_ref_add(struct lu_object *o, + const char *scope, + const void *source) +{ + return lu_ref_add(&o->lo_header->loh_reference, scope, source); +} + +static inline void lu_object_ref_del(struct lu_object *o, + const char *scope, const void *source) +{ + lu_ref_del(&o->lo_header->loh_reference, scope, source); +} + +static inline void lu_object_ref_del_at(struct lu_object *o, + struct lu_ref_link *link, + const char *scope, const void *source) +{ + lu_ref_del_at(&o->lo_header->loh_reference, link, scope, source); +} + +/** input params, should be filled out by mdt */ +struct lu_rdpg { + /** hash */ + __u64 rp_hash; + /** count in bytes */ + unsigned int rp_count; + /** number of pages */ + unsigned int rp_npages; + /** requested attr */ + __u32 rp_attrs; + /** pointers to pages */ + struct page **rp_pages; +}; + +enum lu_xattr_flags { + LU_XATTR_REPLACE = (1 << 0), + LU_XATTR_CREATE = (1 << 1) +}; + +/** @} helpers */ + +/** \name lu_context + * @{ */ + +/** For lu_context health-checks */ +enum lu_context_state { + LCS_INITIALIZED = 1, + LCS_ENTERED, + LCS_LEFT, + LCS_FINALIZED +}; + +/** + * lu_context. Execution context for lu_object methods. Currently associated + * with thread. + * + * All lu_object methods, except device and device type methods (called during + * system initialization and shutdown) are executed "within" some + * lu_context. This means, that pointer to some "current" lu_context is passed + * as an argument to all methods. + * + * All service ptlrpc threads create lu_context as part of their + * initialization. It is possible to create "stand-alone" context for other + * execution environments (like system calls). + * + * lu_object methods mainly use lu_context through lu_context_key interface + * that allows each layer to associate arbitrary pieces of data with each + * context (see pthread_key_create(3) for similar interface). + * + * On a client, lu_context is bound to a thread, see cl_env_get(). + * + * \see lu_context_key + */ +struct lu_context { + /** + * lu_context is used on the client side too. Yet we don't want to + * allocate values of server-side keys for the client contexts and + * vice versa. + * + * To achieve this, set of tags in introduced. Contexts and keys are + * marked with tags. Key value are created only for context whose set + * of tags has non-empty intersection with one for key. Tags are taken + * from enum lu_context_tag. + */ + __u32 lc_tags; + enum lu_context_state lc_state; + /** + * Pointer to the home service thread. NULL for other execution + * contexts. + */ + struct ptlrpc_thread *lc_thread; + /** + * Pointer to an array with key values. Internal implementation + * detail. + */ + void **lc_value; + /** + * Linkage into a list of all remembered contexts. Only + * `non-transient' contexts, i.e., ones created for service threads + * are placed here. + */ + struct list_head lc_remember; + /** + * Version counter used to skip calls to lu_context_refill() when no + * keys were registered. + */ + unsigned lc_version; + /** + * Debugging cookie. + */ + unsigned lc_cookie; +}; + +/** + * lu_context_key interface. Similar to pthread_key. + */ + +enum lu_context_tag { + /** + * Thread on md server + */ + LCT_MD_THREAD = 1 << 0, + /** + * Thread on dt server + */ + LCT_DT_THREAD = 1 << 1, + /** + * Context for transaction handle + */ + LCT_TX_HANDLE = 1 << 2, + /** + * Thread on client + */ + LCT_CL_THREAD = 1 << 3, + /** + * A per-request session on a server, and a per-system-call session on + * a client. + */ + LCT_SESSION = 1 << 4, + /** + * A per-request data on OSP device + */ + LCT_OSP_THREAD = 1 << 5, + /** + * MGS device thread + */ + LCT_MG_THREAD = 1 << 6, + /** + * Context for local operations + */ + LCT_LOCAL = 1 << 7, + /** + * Set when at least one of keys, having values in this context has + * non-NULL lu_context_key::lct_exit() method. This is used to + * optimize lu_context_exit() call. + */ + LCT_HAS_EXIT = 1 << 28, + /** + * Don't add references for modules creating key values in that context. + * This is only for contexts used internally by lu_object framework. + */ + LCT_NOREF = 1 << 29, + /** + * Key is being prepared for retiring, don't create new values for it. + */ + LCT_QUIESCENT = 1 << 30, + /** + * Context should be remembered. + */ + LCT_REMEMBER = 1 << 31, + /** + * Contexts usable in cache shrinker thread. + */ + LCT_SHRINKER = LCT_MD_THREAD|LCT_DT_THREAD|LCT_CL_THREAD|LCT_NOREF +}; + +/** + * Key. Represents per-context value slot. + * + * Keys are usually registered when module owning the key is initialized, and + * de-registered when module is unloaded. Once key is registered, all new + * contexts with matching tags, will get key value. "Old" contexts, already + * initialized at the time of key registration, can be forced to get key value + * by calling lu_context_refill(). + * + * Every key value is counted in lu_context_key::lct_used and acquires a + * reference on an owning module. This means, that all key values have to be + * destroyed before module can be unloaded. This is usually achieved by + * stopping threads started by the module, that created contexts in their + * entry functions. Situation is complicated by the threads shared by multiple + * modules, like ptlrpcd daemon on a client. To work around this problem, + * contexts, created in such threads, are `remembered' (see + * LCT_REMEMBER)---i.e., added into a global list. When module is preparing + * for unloading it does the following: + * + * - marks its keys as `quiescent' (lu_context_tag::LCT_QUIESCENT) + * preventing new key values from being allocated in the new contexts, + * and + * + * - scans a list of remembered contexts, destroying values of module + * keys, thus releasing references to the module. + * + * This is done by lu_context_key_quiesce(). If module is re-activated + * before key has been de-registered, lu_context_key_revive() call clears + * `quiescent' marker. + * + * lu_context code doesn't provide any internal synchronization for these + * activities---it's assumed that startup (including threads start-up) and + * shutdown are serialized by some external means. + * + * \see lu_context + */ +struct lu_context_key { + /** + * Set of tags for which values of this key are to be instantiated. + */ + __u32 lct_tags; + /** + * Value constructor. This is called when new value is created for a + * context. Returns pointer to new value of error pointer. + */ + void *(*lct_init)(const struct lu_context *ctx, + struct lu_context_key *key); + /** + * Value destructor. Called when context with previously allocated + * value of this slot is destroyed. \a data is a value that was returned + * by a matching call to lu_context_key::lct_init(). + */ + void (*lct_fini)(const struct lu_context *ctx, + struct lu_context_key *key, void *data); + /** + * Optional method called on lu_context_exit() for all allocated + * keys. Can be used by debugging code checking that locks are + * released, etc. + */ + void (*lct_exit)(const struct lu_context *ctx, + struct lu_context_key *key, void *data); + /** + * Internal implementation detail: index within lu_context::lc_value[] + * reserved for this key. + */ + int lct_index; + /** + * Internal implementation detail: number of values created for this + * key. + */ + atomic_t lct_used; + /** + * Internal implementation detail: module for this key. + */ + module_t *lct_owner; + /** + * References to this key. For debugging. + */ + struct lu_ref lct_reference; +}; + +#define LU_KEY_INIT(mod, type) \ + static void* mod##_key_init(const struct lu_context *ctx, \ + struct lu_context_key *key) \ + { \ + type *value; \ + \ + CLASSERT(PAGE_CACHE_SIZE >= sizeof (*value)); \ + \ + OBD_ALLOC_PTR(value); \ + if (value == NULL) \ + value = ERR_PTR(-ENOMEM); \ + \ + return value; \ + } \ + struct __##mod##__dummy_init {;} /* semicolon catcher */ + +#define LU_KEY_FINI(mod, type) \ + static void mod##_key_fini(const struct lu_context *ctx, \ + struct lu_context_key *key, void* data) \ + { \ + type *info = data; \ + \ + OBD_FREE_PTR(info); \ + } \ + struct __##mod##__dummy_fini {;} /* semicolon catcher */ + +#define LU_KEY_INIT_FINI(mod, type) \ + LU_KEY_INIT(mod,type); \ + LU_KEY_FINI(mod,type) + +#define LU_CONTEXT_KEY_DEFINE(mod, tags) \ + struct lu_context_key mod##_thread_key = { \ + .lct_tags = tags, \ + .lct_init = mod##_key_init, \ + .lct_fini = mod##_key_fini \ + } + +#define LU_CONTEXT_KEY_INIT(key) \ +do { \ + (key)->lct_owner = THIS_MODULE; \ +} while (0) + +int lu_context_key_register(struct lu_context_key *key); +void lu_context_key_degister(struct lu_context_key *key); +void *lu_context_key_get (const struct lu_context *ctx, + const struct lu_context_key *key); +void lu_context_key_quiesce (struct lu_context_key *key); +void lu_context_key_revive (struct lu_context_key *key); + + +/* + * LU_KEY_INIT_GENERIC() has to be a macro to correctly determine an + * owning module. + */ + +#define LU_KEY_INIT_GENERIC(mod) \ + static void mod##_key_init_generic(struct lu_context_key *k, ...) \ + { \ + struct lu_context_key *key = k; \ + va_list args; \ + \ + va_start(args, k); \ + do { \ + LU_CONTEXT_KEY_INIT(key); \ + key = va_arg(args, struct lu_context_key *); \ + } while (key != NULL); \ + va_end(args); \ + } + +#define LU_TYPE_INIT(mod, ...) \ + LU_KEY_INIT_GENERIC(mod) \ + static int mod##_type_init(struct lu_device_type *t) \ + { \ + mod##_key_init_generic(__VA_ARGS__, NULL); \ + return lu_context_key_register_many(__VA_ARGS__, NULL); \ + } \ + struct __##mod##_dummy_type_init {;} + +#define LU_TYPE_FINI(mod, ...) \ + static void mod##_type_fini(struct lu_device_type *t) \ + { \ + lu_context_key_degister_many(__VA_ARGS__, NULL); \ + } \ + struct __##mod##_dummy_type_fini {;} + +#define LU_TYPE_START(mod, ...) \ + static void mod##_type_start(struct lu_device_type *t) \ + { \ + lu_context_key_revive_many(__VA_ARGS__, NULL); \ + } \ + struct __##mod##_dummy_type_start {;} + +#define LU_TYPE_STOP(mod, ...) \ + static void mod##_type_stop(struct lu_device_type *t) \ + { \ + lu_context_key_quiesce_many(__VA_ARGS__, NULL); \ + } \ + struct __##mod##_dummy_type_stop {;} + + + +#define LU_TYPE_INIT_FINI(mod, ...) \ + LU_TYPE_INIT(mod, __VA_ARGS__); \ + LU_TYPE_FINI(mod, __VA_ARGS__); \ + LU_TYPE_START(mod, __VA_ARGS__); \ + LU_TYPE_STOP(mod, __VA_ARGS__) + +int lu_context_init (struct lu_context *ctx, __u32 tags); +void lu_context_fini (struct lu_context *ctx); +void lu_context_enter (struct lu_context *ctx); +void lu_context_exit (struct lu_context *ctx); +int lu_context_refill(struct lu_context *ctx); + +/* + * Helper functions to operate on multiple keys. These are used by the default + * device type operations, defined by LU_TYPE_INIT_FINI(). + */ + +int lu_context_key_register_many(struct lu_context_key *k, ...); +void lu_context_key_degister_many(struct lu_context_key *k, ...); +void lu_context_key_revive_many (struct lu_context_key *k, ...); +void lu_context_key_quiesce_many (struct lu_context_key *k, ...); + +/* + * update/clear ctx/ses tags. + */ +void lu_context_tags_update(__u32 tags); +void lu_context_tags_clear(__u32 tags); +void lu_session_tags_update(__u32 tags); +void lu_session_tags_clear(__u32 tags); + +/** + * Environment. + */ +struct lu_env { + /** + * "Local" context, used to store data instead of stack. + */ + struct lu_context le_ctx; + /** + * "Session" context for per-request data. + */ + struct lu_context *le_ses; +}; + +int lu_env_init (struct lu_env *env, __u32 tags); +void lu_env_fini (struct lu_env *env); +int lu_env_refill(struct lu_env *env); +int lu_env_refill_by_tags(struct lu_env *env, __u32 ctags, __u32 stags); + +/** @} lu_context */ + +/** + * Output site statistical counters into a buffer. Suitable for + * ll_rd_*()-style functions. + */ +int lu_site_stats_print(const struct lu_site *s, struct seq_file *m); + +/** + * Common name structure to be passed around for various name related methods. + */ +struct lu_name { + const char *ln_name; + int ln_namelen; +}; + +/** + * Common buffer structure to be passed around for various xattr_{s,g}et() + * methods. + */ +struct lu_buf { + void *lb_buf; + ssize_t lb_len; +}; + +#define DLUBUF "(%p %zu)" +#define PLUBUF(buf) (buf)->lb_buf, (buf)->lb_len +/** + * One-time initializers, called at obdclass module initialization, not + * exported. + */ + +/** + * Initialization of global lu_* data. + */ +int lu_global_init(void); + +/** + * Dual to lu_global_init(). + */ +void lu_global_fini(void); + +struct lu_kmem_descr { + struct kmem_cache **ckd_cache; + const char *ckd_name; + const size_t ckd_size; +}; + +int lu_kmem_init(struct lu_kmem_descr *caches); +void lu_kmem_fini(struct lu_kmem_descr *caches); + +void lu_object_assign_fid(const struct lu_env *env, struct lu_object *o, + const struct lu_fid *fid); +struct lu_object *lu_object_anon(const struct lu_env *env, + struct lu_device *dev, + const struct lu_object_conf *conf); + +/** null buffer */ +extern struct lu_buf LU_BUF_NULL; + +void lu_buf_free(struct lu_buf *buf); +void lu_buf_alloc(struct lu_buf *buf, int size); +void lu_buf_realloc(struct lu_buf *buf, int size); + +int lu_buf_check_and_grow(struct lu_buf *buf, int len); +struct lu_buf *lu_buf_check_and_alloc(struct lu_buf *buf, int len); + +/** @} lu */ +#endif /* __LUSTRE_LU_OBJECT_H */ |