// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0/* Copyright (c) 2018 Mellanox Technologies. All rights reserved */ #include <linux/module.h>#include <linux/slab.h>#include <linux/rhashtable.h>#include <linux/idr.h>#include <linux/list.h>#include <linux/sort.h>#include <linux/objagg.h> #define CREATE_TRACE_POINTS#include <trace/events/objagg.h> struct objagg_hints { struct rhashtable node_ht; struct rhashtable_params ht_params; struct list_head node_list; unsigned int node_count; unsigned int root_count; unsigned int refcount; const struct objagg_ops *ops;}; struct objagg_hints_node { struct rhash_head ht_node; /* member of objagg_hints->node_ht */ struct list_head list; /* member of objagg_hints->node_list */ struct objagg_hints_node *parent; unsigned int root_id; struct objagg_obj_stats_info stats_info; unsigned long obj[0];}; static struct objagg_hints_node *objagg_hints_lookup(struct objagg_hints *objagg_hints, void *obj){ if (!objagg_hints) return NULL; return rhashtable_lookup_fast(&objagg_hints->node_ht, obj, objagg_hints->ht_params);} struct objagg { const struct objagg_ops *ops; void *priv; struct rhashtable obj_ht; struct rhashtable_params ht_params; struct list_head obj_list; unsigned int obj_count; struct ida root_ida; struct objagg_hints *hints;}; struct objagg_obj { struct rhash_head ht_node; /* member of objagg->obj_ht */ struct list_head list; /* member of objagg->obj_list */ struct objagg_obj *parent; /* if the object is nested, this * holds pointer to parent, otherwise NULL */ union { void *delta_priv; /* user delta private */ void *root_priv; /* user root private */ }; unsigned int root_id; unsigned int refcount; /* counts number of users of this object * including nested objects */ struct objagg_obj_stats stats; unsigned long obj[0];}; static unsigned int objagg_obj_ref_inc(struct objagg_obj *objagg_obj){ return ++objagg_obj->refcount;} static unsigned int objagg_obj_ref_dec(struct objagg_obj *objagg_obj){ return --objagg_obj->refcount;} static void objagg_obj_stats_inc(struct objagg_obj *objagg_obj){ objagg_obj->stats.user_count++; objagg_obj->stats.delta_user_count++; if (objagg_obj->parent) objagg_obj->parent->stats.delta_user_count++;} static void objagg_obj_stats_dec(struct objagg_obj *objagg_obj){ objagg_obj->stats.user_count--; objagg_obj->stats.delta_user_count--; if (objagg_obj->parent) objagg_obj->parent->stats.delta_user_count--;} static bool objagg_obj_is_root(const struct objagg_obj *objagg_obj){ /* Nesting is not supported, so we can use ->parent * to figure out if the object is root. */ return !objagg_obj->parent;} /** * objagg_obj_root_priv - obtains root private for an object * @objagg_obj: objagg object instance * * Note: all locking must be provided by the caller. * * Either the object is root itself when the private is returned * directly, or the parent is root and its private is returned * instead. * * Returns a user private root pointer. */const void *objagg_obj_root_priv(const struct objagg_obj *objagg_obj){ if (objagg_obj_is_root(objagg_obj)) return objagg_obj->root_priv; WARN_ON(!objagg_obj_is_root(objagg_obj->parent)); return objagg_obj->parent->root_priv;}EXPORT_SYMBOL(objagg_obj_root_priv); /** * objagg_obj_delta_priv - obtains delta private for an object * @objagg_obj: objagg object instance * * Note: all locking must be provided by the caller. * * Returns user private delta pointer or NULL in case the passed * object is root. */const void *objagg_obj_delta_priv(const struct objagg_obj *objagg_obj){ if (objagg_obj_is_root(objagg_obj)) return NULL; return objagg_obj->delta_priv;}EXPORT_SYMBOL(objagg_obj_delta_priv); /** * objagg_obj_raw - obtains object user private pointer * @objagg_obj: objagg object instance * * Note: all locking must be provided by the caller. * * Returns user private pointer as was passed to objagg_obj_get() by "obj" arg. */const void *objagg_obj_raw(const struct objagg_obj *objagg_obj){ return objagg_obj->obj;}EXPORT_SYMBOL(objagg_obj_raw); static struct objagg_obj *objagg_obj_lookup(struct objagg *objagg, void *obj){ return rhashtable_lookup_fast(&objagg->obj_ht, obj, objagg->ht_params);} static int objagg_obj_parent_assign(struct objagg *objagg, struct objagg_obj *objagg_obj, struct objagg_obj *parent, bool take_parent_ref){ void *delta_priv; delta_priv = objagg->ops->delta_create(objagg->priv, parent->obj, objagg_obj->obj); if (IS_ERR(delta_priv)) return PTR_ERR(delta_priv); /* User returned a delta private, that means that * our object can be aggregated into the parent. */ objagg_obj->parent = parent; objagg_obj->delta_priv = delta_priv; if (take_parent_ref) objagg_obj_ref_inc(objagg_obj->parent); trace_objagg_obj_parent_assign(objagg, objagg_obj, parent, parent->refcount); return 0;} static int objagg_obj_parent_lookup_assign(struct objagg *objagg, struct objagg_obj *objagg_obj){ struct objagg_obj *objagg_obj_cur; int err; list_for_each_entry(objagg_obj_cur, &objagg->obj_list, list) { /* Nesting is not supported. In case the object * is not root, it cannot be assigned as parent. */ if (!objagg_obj_is_root(objagg_obj_cur)) continue; err = objagg_obj_parent_assign(objagg, objagg_obj, objagg_obj_cur, true); if (!err) return 0; } return -ENOENT;} static void __objagg_obj_put(struct objagg *objagg, struct objagg_obj *objagg_obj); static void objagg_obj_parent_unassign(struct objagg *objagg, struct objagg_obj *objagg_obj){ trace_objagg_obj_parent_unassign(objagg, objagg_obj, objagg_obj->parent, objagg_obj->parent->refcount); objagg->ops->delta_destroy(objagg->priv, objagg_obj->delta_priv); __objagg_obj_put(objagg, objagg_obj->parent);} static int objagg_obj_root_id_alloc(struct objagg *objagg, struct objagg_obj *objagg_obj, struct objagg_hints_node *hnode){ unsigned int min, max; int root_id; /* In case there are no hints available, the root id is invalid. */ if (!objagg->hints) { objagg_obj->root_id = OBJAGG_OBJ_ROOT_ID_INVALID; return 0; } if (hnode) { min = hnode->root_id; max = hnode->root_id; } else { /* For objects with no hint, start after the last * hinted root_id. */ min = objagg->hints->root_count; max = ~0; } root_id = ida_alloc_range(&objagg->root_ida, min, max, GFP_KERNEL); if (root_id < 0) return root_id; objagg_obj->root_id = root_id; return 0;} static void objagg_obj_root_id_free(struct objagg *objagg, struct objagg_obj *objagg_obj){ if (!objagg->hints) return; ida_free(&objagg->root_ida, objagg_obj->root_id);} static int objagg_obj_root_create(struct objagg *objagg, struct objagg_obj *objagg_obj, struct objagg_hints_node *hnode){ int err; err = objagg_obj_root_id_alloc(objagg, objagg_obj, hnode); if (err) return err; objagg_obj->root_priv = objagg->ops->root_create(objagg->priv, objagg_obj->obj, objagg_obj->root_id); if (IS_ERR(objagg_obj->root_priv)) { err = PTR_ERR(objagg_obj->root_priv); goto err_root_create; } trace_objagg_obj_root_create(objagg, objagg_obj); return 0; err_root_create: objagg_obj_root_id_free(objagg, objagg_obj); return err;} static void objagg_obj_root_destroy(struct objagg *objagg, struct objagg_obj *objagg_obj){ trace_objagg_obj_root_destroy(objagg, objagg_obj); objagg->ops->root_destroy(objagg->priv, objagg_obj->root_priv); objagg_obj_root_id_free(objagg, objagg_obj);} static struct objagg_obj *__objagg_obj_get(struct objagg *objagg, void *obj); static int objagg_obj_init_with_hints(struct objagg *objagg, struct objagg_obj *objagg_obj, bool *hint_found){ struct objagg_hints_node *hnode; struct objagg_obj *parent; int err; hnode = objagg_hints_lookup(objagg->hints, objagg_obj->obj); if (!hnode) { *hint_found = false; return 0; } *hint_found = true; if (!hnode->parent) return objagg_obj_root_create(objagg, objagg_obj, hnode); parent = __objagg_obj_get(objagg, hnode->parent->obj); if (IS_ERR(parent)) return PTR_ERR(parent); err = objagg_obj_parent_assign(objagg, objagg_obj, parent, false); if (err) { *hint_found = false; err = 0; goto err_parent_assign; } return 0; err_parent_assign: objagg_obj_put(objagg, parent); return err;} static int objagg_obj_init(struct objagg *objagg, struct objagg_obj *objagg_obj){ bool hint_found; int err; /* First, try to use hints if they are available and * if they provide result. */ err = objagg_obj_init_with_hints(objagg, objagg_obj, &hint_found); if (err) return err; if (hint_found) return 0; /* Try to find if the object can be aggregated under an existing one. */ err = objagg_obj_parent_lookup_assign(objagg, objagg_obj); if (!err) return 0; /* If aggregation is not possible, make the object a root. */ return objagg_obj_root_create(objagg, objagg_obj, NULL);} static void objagg_obj_fini(struct objagg *objagg, struct objagg_obj *objagg_obj){ if (!objagg_obj_is_root(objagg_obj)) objagg_obj_parent_unassign(objagg, objagg_obj); else objagg_obj_root_destroy(objagg, objagg_obj);} static struct objagg_obj *objagg_obj_create(struct objagg *objagg, void *obj){ struct objagg_obj *objagg_obj; int err; objagg_obj = kzalloc(sizeof(*objagg_obj) + objagg->ops->obj_size, GFP_KERNEL); if (!objagg_obj) return ERR_PTR(-ENOMEM); objagg_obj_ref_inc(objagg_obj); memcpy(objagg_obj->obj, obj, objagg->ops->obj_size); err = objagg_obj_init(objagg, objagg_obj); if (err) goto err_obj_init; err = rhashtable_insert_fast(&objagg->obj_ht, &objagg_obj->ht_node, objagg->ht_params); if (err) goto err_ht_insert; list_add(&objagg_obj->list, &objagg->obj_list); objagg->obj_count++; trace_objagg_obj_create(objagg, objagg_obj); return objagg_obj; err_ht_insert: objagg_obj_fini(objagg, objagg_obj);err_obj_init: kfree(objagg_obj); return ERR_PTR(err);} static struct objagg_obj *__objagg_obj_get(struct objagg *objagg, void *obj){ struct objagg_obj *objagg_obj; /* First, try to find the object exactly as user passed it, * perhaps it is already in use. */ objagg_obj = objagg_obj_lookup(objagg, obj); if (objagg_obj) { objagg_obj_ref_inc(objagg_obj); return objagg_obj; } return objagg_obj_create(objagg, obj);} /** * objagg_obj_get - gets an object within objagg instance * @objagg: objagg instance * @obj: user-specific private object pointer * * Note: all locking must be provided by the caller. * * Size of the "obj" memory is specified in "objagg->ops". * * There are 3 main options this function wraps: * 1) The object according to "obj" already exist. In that case * the reference counter is incrementes and the object is returned. * 2) The object does not exist, but it can be aggregated within * another object. In that case, user ops->delta_create() is called * to obtain delta data and a new object is created with returned * user-delta private pointer. * 3) The object does not exist and cannot be aggregated into * any of the existing objects. In that case, user ops->root_create() * is called to create the root and a new object is created with * returned user-root private pointer. * * Returns a pointer to objagg object instance in case of success, * otherwise it returns pointer error using ERR_PTR macro. */struct objagg_obj *objagg_obj_get(struct objagg *objagg, void *obj){ struct objagg_obj *objagg_obj; objagg_obj = __objagg_obj_get(objagg, obj); if (IS_ERR(objagg_obj)) return objagg_obj; objagg_obj_stats_inc(objagg_obj); trace_objagg_obj_get(objagg, objagg_obj, objagg_obj->refcount); return objagg_obj;}EXPORT_SYMBOL(objagg_obj_get); static void objagg_obj_destroy(struct objagg *objagg, struct objagg_obj *objagg_obj){ trace_objagg_obj_destroy(objagg, objagg_obj); --objagg->obj_count; list_del(&objagg_obj->list); rhashtable_remove_fast(&objagg->obj_ht, &objagg_obj->ht_node, objagg->ht_params); objagg_obj_fini(objagg, objagg_obj); kfree(objagg_obj);} static void __objagg_obj_put(struct objagg *objagg, struct objagg_obj *objagg_obj){ if (!objagg_obj_ref_dec(objagg_obj)) objagg_obj_destroy(objagg, objagg_obj);} /** * objagg_obj_put - puts an object within objagg instance * @objagg: objagg instance * @objagg_obj: objagg object instance * * Note: all locking must be provided by the caller. * * Symmetric to objagg_obj_get(). */void objagg_obj_put(struct objagg *objagg, struct objagg_obj *objagg_obj){ trace_objagg_obj_put(objagg, objagg_obj, objagg_obj->refcount); objagg_obj_stats_dec(objagg_obj); __objagg_obj_put(objagg, objagg_obj);}EXPORT_SYMBOL(objagg_obj_put); /** * objagg_create - creates a new objagg instance * @ops: user-specific callbacks * @objagg_hints: hints, can be NULL * @priv: pointer to a private data passed to the ops * * Note: all locking must be provided by the caller. * * The purpose of the library is to provide an infrastructure to * aggregate user-specified objects. Library does not care about the type * of the object. User fills-up ops which take care of the specific * user object manipulation. * * As a very stupid example, consider integer numbers. For example * number 8 as a root object. That can aggregate number 9 with delta 1,Lines 1–500 of 1056. Load more
// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0 /* Copyright (c) 2018 Mellanox Technologies. All rights reserved */ #include <linux/module.h> #include <linux/slab.h> #include <linux/rhashtable.h> #include <linux/idr.h> #include <linux/list.h> #include <linux/sort.h> #include <linux/objagg.h> #define CREATE_TRACE_POINTS #include <trace/events/objagg.h> struct objagg_hints { struct rhashtable node_ht; struct rhashtable_params ht_params; struct list_head node_list; unsigned int node_count; unsigned int root_count; unsigned int refcount; const struct objagg_ops *ops; }; struct objagg_hints_node { struct rhash_head ht_node; /* member of objagg_hints->node_ht */ struct list_head list; /* member of objagg_hints->node_list */ struct objagg_hints_node *parent; unsigned int root_id; struct objagg_obj_stats_info stats_info; unsigned long obj[0]; }; static struct objagg_hints_node * objagg_hints_lookup(struct objagg_hints *objagg_hints, void *obj) { if (!objagg_hints) return NULL; return rhashtable_lookup_fast(&objagg_hints->node_ht, obj, objagg_hints->ht_params); } struct objagg { const struct objagg_ops *ops; void *priv; struct rhashtable obj_ht; struct rhashtable_params ht_params; struct list_head obj_list; unsigned int obj_count; struct ida root_ida; struct objagg_hints *hints; }; struct objagg_obj { struct rhash_head ht_node; /* member of objagg->obj_ht */ struct list_head list; /* member of objagg->obj_list */ struct objagg_obj *parent; /* if the object is nested, this * holds pointer to parent, otherwise NULL */ union { void *delta_priv; /* user delta private */ void *root_priv; /* user root private */ }; unsigned int root_id; unsigned int refcount; /* counts number of users of this object * including nested objects */ struct objagg_obj_stats stats; unsigned long obj[0]; }; static unsigned int objagg_obj_ref_inc(struct objagg_obj *objagg_obj) { return ++objagg_obj->refcount; } static unsigned int objagg_obj_ref_dec(struct objagg_obj *objagg_obj) { return --objagg_obj->refcount; } static void objagg_obj_stats_inc(struct objagg_obj *objagg_obj) { objagg_obj->stats.user_count++; objagg_obj->stats.delta_user_count++; if (objagg_obj->parent) objagg_obj->parent->stats.delta_user_count++; } static void objagg_obj_stats_dec(struct objagg_obj *objagg_obj) { objagg_obj->stats.user_count--; objagg_obj->stats.delta_user_count--; if (objagg_obj->parent) objagg_obj->parent->stats.delta_user_count--; } static bool objagg_obj_is_root(const struct objagg_obj *objagg_obj) { /* Nesting is not supported, so we can use ->parent * to figure out if the object is root. */ return !objagg_obj->parent; } /** * objagg_obj_root_priv - obtains root private for an object * @objagg_obj: objagg object instance * * Note: all locking must be provided by the caller. * * Either the object is root itself when the private is returned * directly, or the parent is root and its private is returned * instead. * * Returns a user private root pointer. */ const void *objagg_obj_root_priv(const struct objagg_obj *objagg_obj) { if (objagg_obj_is_root(objagg_obj)) return objagg_obj->root_priv; WARN_ON(!objagg_obj_is_root(objagg_obj->parent)); return objagg_obj->parent->root_priv; } EXPORT_SYMBOL(objagg_obj_root_priv); /** * objagg_obj_delta_priv - obtains delta private for an object * @objagg_obj: objagg object instance * * Note: all locking must be provided by the caller. * * Returns user private delta pointer or NULL in case the passed * object is root. */ const void *objagg_obj_delta_priv(const struct objagg_obj *objagg_obj) { if (objagg_obj_is_root(objagg_obj)) return NULL; return objagg_obj->delta_priv; } EXPORT_SYMBOL(objagg_obj_delta_priv); /** * objagg_obj_raw - obtains object user private pointer * @objagg_obj: objagg object instance * * Note: all locking must be provided by the caller. * * Returns user private pointer as was passed to objagg_obj_get() by "obj" arg. */ const void *objagg_obj_raw(const struct objagg_obj *objagg_obj) { return objagg_obj->obj; } EXPORT_SYMBOL(objagg_obj_raw); static struct objagg_obj *objagg_obj_lookup(struct objagg *objagg, void *obj) { return rhashtable_lookup_fast(&objagg->obj_ht, obj, objagg->ht_params); } static int objagg_obj_parent_assign(struct objagg *objagg, struct objagg_obj *objagg_obj, struct objagg_obj *parent, bool take_parent_ref) { void *delta_priv; delta_priv = objagg->ops->delta_create(objagg->priv, parent->obj, objagg_obj->obj); if (IS_ERR(delta_priv)) return PTR_ERR(delta_priv); /* User returned a delta private, that means that * our object can be aggregated into the parent. */ objagg_obj->parent = parent; objagg_obj->delta_priv = delta_priv; if (take_parent_ref) objagg_obj_ref_inc(objagg_obj->parent); trace_objagg_obj_parent_assign(objagg, objagg_obj, parent, parent->refcount); return 0; } static int objagg_obj_parent_lookup_assign(struct objagg *objagg, struct objagg_obj *objagg_obj) { struct objagg_obj *objagg_obj_cur; int err; list_for_each_entry(objagg_obj_cur, &objagg->obj_list, list) { /* Nesting is not supported. In case the object * is not root, it cannot be assigned as parent. */ if (!objagg_obj_is_root(objagg_obj_cur)) continue; err = objagg_obj_parent_assign(objagg, objagg_obj, objagg_obj_cur, true); if (!err) return 0; } return -ENOENT; } static void __objagg_obj_put(struct objagg *objagg, struct objagg_obj *objagg_obj); static void objagg_obj_parent_unassign(struct objagg *objagg, struct objagg_obj *objagg_obj) { trace_objagg_obj_parent_unassign(objagg, objagg_obj, objagg_obj->parent, objagg_obj->parent->refcount); objagg->ops->delta_destroy(objagg->priv, objagg_obj->delta_priv); __objagg_obj_put(objagg, objagg_obj->parent); } static int objagg_obj_root_id_alloc(struct objagg *objagg, struct objagg_obj *objagg_obj, struct objagg_hints_node *hnode) { unsigned int min, max; int root_id; /* In case there are no hints available, the root id is invalid. */ if (!objagg->hints) { objagg_obj->root_id = OBJAGG_OBJ_ROOT_ID_INVALID; return 0; } if (hnode) { min = hnode->root_id; max = hnode->root_id; } else { /* For objects with no hint, start after the last * hinted root_id. */ min = objagg->hints->root_count; max = ~0; } root_id = ida_alloc_range(&objagg->root_ida, min, max, GFP_KERNEL); if (root_id < 0) return root_id; objagg_obj->root_id = root_id; return 0; } static void objagg_obj_root_id_free(struct objagg *objagg, struct objagg_obj *objagg_obj) { if (!objagg->hints) return; ida_free(&objagg->root_ida, objagg_obj->root_id); } static int objagg_obj_root_create(struct objagg *objagg, struct objagg_obj *objagg_obj, struct objagg_hints_node *hnode) { int err; err = objagg_obj_root_id_alloc(objagg, objagg_obj, hnode); if (err) return err; objagg_obj->root_priv = objagg->ops->root_create(objagg->priv, objagg_obj->obj, objagg_obj->root_id); if (IS_ERR(objagg_obj->root_priv)) { err = PTR_ERR(objagg_obj->root_priv); goto err_root_create; } trace_objagg_obj_root_create(objagg, objagg_obj); return 0; err_root_create: objagg_obj_root_id_free(objagg, objagg_obj); return err; } static void objagg_obj_root_destroy(struct objagg *objagg, struct objagg_obj *objagg_obj) { trace_objagg_obj_root_destroy(objagg, objagg_obj); objagg->ops->root_destroy(objagg->priv, objagg_obj->root_priv); objagg_obj_root_id_free(objagg, objagg_obj); } static struct objagg_obj *__objagg_obj_get(struct objagg *objagg, void *obj); static int objagg_obj_init_with_hints(struct objagg *objagg, struct objagg_obj *objagg_obj, bool *hint_found) { struct objagg_hints_node *hnode; struct objagg_obj *parent; int err; hnode = objagg_hints_lookup(objagg->hints, objagg_obj->obj); if (!hnode) { *hint_found = false; return 0; } *hint_found = true; if (!hnode->parent) return objagg_obj_root_create(objagg, objagg_obj, hnode); parent = __objagg_obj_get(objagg, hnode->parent->obj); if (IS_ERR(parent)) return PTR_ERR(parent); err = objagg_obj_parent_assign(objagg, objagg_obj, parent, false); if (err) { *hint_found = false; err = 0; goto err_parent_assign; } return 0; err_parent_assign: objagg_obj_put(objagg, parent); return err; } static int objagg_obj_init(struct objagg *objagg, struct objagg_obj *objagg_obj) { bool hint_found; int err; /* First, try to use hints if they are available and * if they provide result. */ err = objagg_obj_init_with_hints(objagg, objagg_obj, &hint_found); if (err) return err; if (hint_found) return 0; /* Try to find if the object can be aggregated under an existing one. */ err = objagg_obj_parent_lookup_assign(objagg, objagg_obj); if (!err) return 0; /* If aggregation is not possible, make the object a root. */ return objagg_obj_root_create(objagg, objagg_obj, NULL); } static void objagg_obj_fini(struct objagg *objagg, struct objagg_obj *objagg_obj) { if (!objagg_obj_is_root(objagg_obj)) objagg_obj_parent_unassign(objagg, objagg_obj); else objagg_obj_root_destroy(objagg, objagg_obj); } static struct objagg_obj *objagg_obj_create(struct objagg *objagg, void *obj) { struct objagg_obj *objagg_obj; int err; objagg_obj = kzalloc(sizeof(*objagg_obj) + objagg->ops->obj_size, GFP_KERNEL); if (!objagg_obj) return ERR_PTR(-ENOMEM); objagg_obj_ref_inc(objagg_obj); memcpy(objagg_obj->obj, obj, objagg->ops->obj_size); err = objagg_obj_init(objagg, objagg_obj); if (err) goto err_obj_init; err = rhashtable_insert_fast(&objagg->obj_ht, &objagg_obj->ht_node, objagg->ht_params); if (err) goto err_ht_insert; list_add(&objagg_obj->list, &objagg->obj_list); objagg->obj_count++; trace_objagg_obj_create(objagg, objagg_obj); return objagg_obj; err_ht_insert: objagg_obj_fini(objagg, objagg_obj); err_obj_init: kfree(objagg_obj); return ERR_PTR(err); } static struct objagg_obj *__objagg_obj_get(struct objagg *objagg, void *obj) { struct objagg_obj *objagg_obj; /* First, try to find the object exactly as user passed it, * perhaps it is already in use. */ objagg_obj = objagg_obj_lookup(objagg, obj); if (objagg_obj) { objagg_obj_ref_inc(objagg_obj); return objagg_obj; } return objagg_obj_create(objagg, obj); } /** * objagg_obj_get - gets an object within objagg instance * @objagg: objagg instance * @obj: user-specific private object pointer * * Note: all locking must be provided by the caller. * * Size of the "obj" memory is specified in "objagg->ops". * * There are 3 main options this function wraps: * 1) The object according to "obj" already exist. In that case * the reference counter is incrementes and the object is returned. * 2) The object does not exist, but it can be aggregated within * another object. In that case, user ops->delta_create() is called * to obtain delta data and a new object is created with returned * user-delta private pointer. * 3) The object does not exist and cannot be aggregated into * any of the existing objects. In that case, user ops->root_create() * is called to create the root and a new object is created with * returned user-root private pointer. * * Returns a pointer to objagg object instance in case of success, * otherwise it returns pointer error using ERR_PTR macro. */ struct objagg_obj *objagg_obj_get(struct objagg *objagg, void *obj) { struct objagg_obj *objagg_obj; objagg_obj = __objagg_obj_get(objagg, obj); if (IS_ERR(objagg_obj)) return objagg_obj; objagg_obj_stats_inc(objagg_obj); trace_objagg_obj_get(objagg, objagg_obj, objagg_obj->refcount); return objagg_obj; } EXPORT_SYMBOL(objagg_obj_get); static void objagg_obj_destroy(struct objagg *objagg, struct objagg_obj *objagg_obj) { trace_objagg_obj_destroy(objagg, objagg_obj); --objagg->obj_count; list_del(&objagg_obj->list); rhashtable_remove_fast(&objagg->obj_ht, &objagg_obj->ht_node, objagg->ht_params); objagg_obj_fini(objagg, objagg_obj); kfree(objagg_obj); } static void __objagg_obj_put(struct objagg *objagg, struct objagg_obj *objagg_obj) { if (!objagg_obj_ref_dec(objagg_obj)) objagg_obj_destroy(objagg, objagg_obj); } /** * objagg_obj_put - puts an object within objagg instance * @objagg: objagg instance * @objagg_obj: objagg object instance * * Note: all locking must be provided by the caller. * * Symmetric to objagg_obj_get(). */ void objagg_obj_put(struct objagg *objagg, struct objagg_obj *objagg_obj) { trace_objagg_obj_put(objagg, objagg_obj, objagg_obj->refcount); objagg_obj_stats_dec(objagg_obj); __objagg_obj_put(objagg, objagg_obj); } EXPORT_SYMBOL(objagg_obj_put); /** * objagg_create - creates a new objagg instance * @ops: user-specific callbacks * @objagg_hints: hints, can be NULL * @priv: pointer to a private data passed to the ops * * Note: all locking must be provided by the caller. * * The purpose of the library is to provide an infrastructure to * aggregate user-specified objects. Library does not care about the type * of the object. User fills-up ops which take care of the specific * user object manipulation. * * As a very stupid example, consider integer numbers. For example * number 8 as a root object. That can aggregate number 9 with delta 1,