X-Git-Url: http://git.cascardo.eti.br/?a=blobdiff_plain;f=lib%2Fidr.c;h=73f4d53c02f3deaee2a0df5b2909a218b38a10e8;hb=3fb817f1cd54bedd23e8913051473d574a0f1717;hp=648239079dd21329f0329ddaf12552677149d846;hpb=684baeb1d78ac478a8e5f00aa9ab0ce0837f2a91;p=cascardo%2Flinux.git diff --git a/lib/idr.c b/lib/idr.c index 648239079dd2..73f4d53c02f3 100644 --- a/lib/idr.c +++ b/lib/idr.c @@ -35,10 +35,41 @@ #include #include #include +#include +#include + +#define MAX_IDR_SHIFT (sizeof(int) * 8 - 1) +#define MAX_IDR_BIT (1U << MAX_IDR_SHIFT) + +/* Leave the possibility of an incomplete final layer */ +#define MAX_IDR_LEVEL ((MAX_IDR_SHIFT + IDR_BITS - 1) / IDR_BITS) + +/* Number of id_layer structs to leave in free list */ +#define MAX_IDR_FREE (MAX_IDR_LEVEL * 2) static struct kmem_cache *idr_layer_cache; +static DEFINE_PER_CPU(struct idr_layer *, idr_preload_head); +static DEFINE_PER_CPU(int, idr_preload_cnt); static DEFINE_SPINLOCK(simple_ida_lock); +/* the maximum ID which can be allocated given idr->layers */ +static int idr_max(int layers) +{ + int bits = min_t(int, layers * IDR_BITS, MAX_IDR_SHIFT); + + return (1 << bits) - 1; +} + +/* + * Prefix mask for an idr_layer at @layer. For layer 0, the prefix mask is + * all bits except for the lower IDR_BITS. For layer 1, 2 * IDR_BITS, and + * so on. + */ +static int idr_layer_prefix_mask(int layer) +{ + return ~idr_max(layer + 1); +} + static struct idr_layer *get_from_free_list(struct idr *idp) { struct idr_layer *p; @@ -54,6 +85,50 @@ static struct idr_layer *get_from_free_list(struct idr *idp) return(p); } +/** + * idr_layer_alloc - allocate a new idr_layer + * @gfp_mask: allocation mask + * @layer_idr: optional idr to allocate from + * + * If @layer_idr is %NULL, directly allocate one using @gfp_mask or fetch + * one from the per-cpu preload buffer. If @layer_idr is not %NULL, fetch + * an idr_layer from @idr->id_free. + * + * @layer_idr is to maintain backward compatibility with the old alloc + * interface - idr_pre_get() and idr_get_new*() - and will be removed + * together with per-pool preload buffer. + */ +static struct idr_layer *idr_layer_alloc(gfp_t gfp_mask, struct idr *layer_idr) +{ + struct idr_layer *new; + + /* this is the old path, bypass to get_from_free_list() */ + if (layer_idr) + return get_from_free_list(layer_idr); + + /* try to allocate directly from kmem_cache */ + new = kmem_cache_zalloc(idr_layer_cache, gfp_mask); + if (new) + return new; + + /* + * Try to fetch one from the per-cpu preload buffer if in process + * context. See idr_preload() for details. + */ + if (in_interrupt()) + return NULL; + + preempt_disable(); + new = __this_cpu_read(idr_preload_head); + if (new) { + __this_cpu_write(idr_preload_head, new->ary[0]); + __this_cpu_dec(idr_preload_cnt); + new->ary[0] = NULL; + } + preempt_enable(); + return new; +} + static void idr_layer_rcu_free(struct rcu_head *head) { struct idr_layer *layer; @@ -62,8 +137,10 @@ static void idr_layer_rcu_free(struct rcu_head *head) kmem_cache_free(idr_layer_cache, layer); } -static inline void free_layer(struct idr_layer *p) +static inline void free_layer(struct idr *idr, struct idr_layer *p) { + if (idr->hint && idr->hint == p) + RCU_INIT_POINTER(idr->hint, NULL); call_rcu(&p->rcu_head, idr_layer_rcu_free); } @@ -92,18 +169,18 @@ static void idr_mark_full(struct idr_layer **pa, int id) struct idr_layer *p = pa[0]; int l = 0; - __set_bit(id & IDR_MASK, &p->bitmap); + __set_bit(id & IDR_MASK, p->bitmap); /* * If this layer is full mark the bit in the layer above to * show that this part of the radix tree is full. This may * complete the layer above and require walking up the radix * tree. */ - while (p->bitmap == IDR_FULL) { + while (bitmap_full(p->bitmap, IDR_SIZE)) { if (!(p = pa[++l])) break; id = id >> IDR_BITS; - __set_bit((id & IDR_MASK), &p->bitmap); + __set_bit((id & IDR_MASK), p->bitmap); } } @@ -133,12 +210,29 @@ int idr_pre_get(struct idr *idp, gfp_t gfp_mask) } EXPORT_SYMBOL(idr_pre_get); -static int sub_alloc(struct idr *idp, int *starting_id, struct idr_layer **pa) +/** + * sub_alloc - try to allocate an id without growing the tree depth + * @idp: idr handle + * @starting_id: id to start search at + * @id: pointer to the allocated handle + * @pa: idr_layer[MAX_IDR_LEVEL] used as backtrack buffer + * @gfp_mask: allocation mask for idr_layer_alloc() + * @layer_idr: optional idr passed to idr_layer_alloc() + * + * Allocate an id in range [@starting_id, INT_MAX] from @idp without + * growing its depth. Returns + * + * the allocated id >= 0 if successful, + * -EAGAIN if the tree needs to grow for allocation to succeed, + * -ENOSPC if the id space is exhausted, + * -ENOMEM if more idr_layers need to be allocated. + */ +static int sub_alloc(struct idr *idp, int *starting_id, struct idr_layer **pa, + gfp_t gfp_mask, struct idr *layer_idr) { int n, m, sh; struct idr_layer *p, *new; int l, id, oid; - unsigned long bm; id = *starting_id; restart: @@ -150,8 +244,7 @@ static int sub_alloc(struct idr *idp, int *starting_id, struct idr_layer **pa) * We run around this while until we reach the leaf node... */ n = (id >> (IDR_BITS*l)) & IDR_MASK; - bm = ~p->bitmap; - m = find_next_bit(&bm, IDR_SIZE, n); + m = find_next_zero_bit(p->bitmap, IDR_SIZE, n); if (m == IDR_SIZE) { /* no space available go back to previous layer. */ l++; @@ -161,7 +254,7 @@ static int sub_alloc(struct idr *idp, int *starting_id, struct idr_layer **pa) /* if already at the top layer, we need to grow */ if (id >= 1 << (idp->layers * IDR_BITS)) { *starting_id = id; - return IDR_NEED_TO_GROW; + return -EAGAIN; } p = pa[l]; BUG_ON(!p); @@ -180,17 +273,18 @@ static int sub_alloc(struct idr *idp, int *starting_id, struct idr_layer **pa) id = ((id >> sh) ^ n ^ m) << sh; } if ((id >= MAX_IDR_BIT) || (id < 0)) - return IDR_NOMORE_SPACE; + return -ENOSPC; if (l == 0) break; /* * Create the layer below if it is missing. */ if (!p->ary[m]) { - new = get_from_free_list(idp); + new = idr_layer_alloc(gfp_mask, layer_idr); if (!new) - return -1; + return -ENOMEM; new->layer = l-1; + new->prefix = id & idr_layer_prefix_mask(new->layer); rcu_assign_pointer(p->ary[m], new); p->count++; } @@ -203,7 +297,8 @@ static int sub_alloc(struct idr *idp, int *starting_id, struct idr_layer **pa) } static int idr_get_empty_slot(struct idr *idp, int starting_id, - struct idr_layer **pa) + struct idr_layer **pa, gfp_t gfp_mask, + struct idr *layer_idr) { struct idr_layer *p, *new; int layers, v, id; @@ -214,8 +309,8 @@ build_up: p = idp->top; layers = idp->layers; if (unlikely(!p)) { - if (!(p = get_from_free_list(idp))) - return -1; + if (!(p = idr_layer_alloc(gfp_mask, layer_idr))) + return -ENOMEM; p->layer = 0; layers = 1; } @@ -223,7 +318,7 @@ build_up: * Add a new layer to the top of the tree if the requested * id is larger than the currently allocated space. */ - while ((layers < (MAX_IDR_LEVEL - 1)) && (id >= (1 << (layers*IDR_BITS)))) { + while (id > idr_max(layers)) { layers++; if (!p->count) { /* special case: if the tree is currently empty, @@ -231,9 +326,10 @@ build_up: * upwards. */ p->layer++; + WARN_ON_ONCE(p->prefix); continue; } - if (!(new = get_from_free_list(idp))) { + if (!(new = idr_layer_alloc(gfp_mask, layer_idr))) { /* * The allocation failed. If we built part of * the structure tear it down. @@ -242,45 +338,42 @@ build_up: for (new = p; p && p != idp->top; new = p) { p = p->ary[0]; new->ary[0] = NULL; - new->bitmap = new->count = 0; + new->count = 0; + bitmap_clear(new->bitmap, 0, IDR_SIZE); __move_to_free_list(idp, new); } spin_unlock_irqrestore(&idp->lock, flags); - return -1; + return -ENOMEM; } new->ary[0] = p; new->count = 1; new->layer = layers-1; - if (p->bitmap == IDR_FULL) - __set_bit(0, &new->bitmap); + new->prefix = id & idr_layer_prefix_mask(new->layer); + if (bitmap_full(p->bitmap, IDR_SIZE)) + __set_bit(0, new->bitmap); p = new; } rcu_assign_pointer(idp->top, p); idp->layers = layers; - v = sub_alloc(idp, &id, pa); - if (v == IDR_NEED_TO_GROW) + v = sub_alloc(idp, &id, pa, gfp_mask, layer_idr); + if (v == -EAGAIN) goto build_up; return(v); } -static int idr_get_new_above_int(struct idr *idp, void *ptr, int starting_id) +/* + * @id and @pa are from a successful allocation from idr_get_empty_slot(). + * Install the user pointer @ptr and mark the slot full. + */ +static void idr_fill_slot(struct idr *idr, void *ptr, int id, + struct idr_layer **pa) { - struct idr_layer *pa[MAX_IDR_LEVEL]; - int id; - - id = idr_get_empty_slot(idp, starting_id, pa); - if (id >= 0) { - /* - * Successfully found an empty slot. Install the user - * pointer and mark the slot full. - */ - rcu_assign_pointer(pa[0]->ary[id & IDR_MASK], - (struct idr_layer *)ptr); - pa[0]->count++; - idr_mark_full(pa, id); - } + /* update hint used for lookup, cleared from free_layer() */ + rcu_assign_pointer(idr->hint, pa[0]); - return id; + rcu_assign_pointer(pa[0]->ary[id & IDR_MASK], (struct idr_layer *)ptr); + pa[0]->count++; + idr_mark_full(pa, id); } /** @@ -303,49 +396,124 @@ static int idr_get_new_above_int(struct idr *idp, void *ptr, int starting_id) */ int idr_get_new_above(struct idr *idp, void *ptr, int starting_id, int *id) { + struct idr_layer *pa[MAX_IDR_LEVEL + 1]; int rv; - rv = idr_get_new_above_int(idp, ptr, starting_id); - /* - * This is a cheap hack until the IDR code can be fixed to - * return proper error values. - */ + rv = idr_get_empty_slot(idp, starting_id, pa, 0, idp); if (rv < 0) - return _idr_rc_to_errno(rv); + return rv == -ENOMEM ? -EAGAIN : rv; + + idr_fill_slot(idp, ptr, rv, pa); *id = rv; return 0; } EXPORT_SYMBOL(idr_get_new_above); /** - * idr_get_new - allocate new idr entry - * @idp: idr handle - * @ptr: pointer you want associated with the id - * @id: pointer to the allocated handle + * idr_preload - preload for idr_alloc() + * @gfp_mask: allocation mask to use for preloading * - * If allocation from IDR's private freelist fails, idr_get_new_above() will - * return %-EAGAIN. The caller should retry the idr_pre_get() call to refill - * IDR's preallocation and then retry the idr_get_new_above() call. + * Preload per-cpu layer buffer for idr_alloc(). Can only be used from + * process context and each idr_preload() invocation should be matched with + * idr_preload_end(). Note that preemption is disabled while preloaded. * - * If the idr is full idr_get_new_above() will return %-ENOSPC. + * The first idr_alloc() in the preloaded section can be treated as if it + * were invoked with @gfp_mask used for preloading. This allows using more + * permissive allocation masks for idrs protected by spinlocks. + * + * For example, if idr_alloc() below fails, the failure can be treated as + * if idr_alloc() were called with GFP_KERNEL rather than GFP_NOWAIT. + * + * idr_preload(GFP_KERNEL); + * spin_lock(lock); + * + * id = idr_alloc(idr, ptr, start, end, GFP_NOWAIT); * - * @id returns a value in the range %0 ... %0x7fffffff + * spin_unlock(lock); + * idr_preload_end(); + * if (id < 0) + * error; */ -int idr_get_new(struct idr *idp, void *ptr, int *id) +void idr_preload(gfp_t gfp_mask) { - int rv; + /* + * Consuming preload buffer from non-process context breaks preload + * allocation guarantee. Disallow usage from those contexts. + */ + WARN_ON_ONCE(in_interrupt()); + might_sleep_if(gfp_mask & __GFP_WAIT); + + preempt_disable(); - rv = idr_get_new_above_int(idp, ptr, 0); /* - * This is a cheap hack until the IDR code can be fixed to - * return proper error values. + * idr_alloc() is likely to succeed w/o full idr_layer buffer and + * return value from idr_alloc() needs to be checked for failure + * anyway. Silently give up if allocation fails. The caller can + * treat failures from idr_alloc() as if idr_alloc() were called + * with @gfp_mask which should be enough. */ - if (rv < 0) - return _idr_rc_to_errno(rv); - *id = rv; - return 0; + while (__this_cpu_read(idr_preload_cnt) < MAX_IDR_FREE) { + struct idr_layer *new; + + preempt_enable(); + new = kmem_cache_zalloc(idr_layer_cache, gfp_mask); + preempt_disable(); + if (!new) + break; + + /* link the new one to per-cpu preload list */ + new->ary[0] = __this_cpu_read(idr_preload_head); + __this_cpu_write(idr_preload_head, new); + __this_cpu_inc(idr_preload_cnt); + } } -EXPORT_SYMBOL(idr_get_new); +EXPORT_SYMBOL(idr_preload); + +/** + * idr_alloc - allocate new idr entry + * @idr: the (initialized) idr + * @ptr: pointer to be associated with the new id + * @start: the minimum id (inclusive) + * @end: the maximum id (exclusive, <= 0 for max) + * @gfp_mask: memory allocation flags + * + * Allocate an id in [start, end) and associate it with @ptr. If no ID is + * available in the specified range, returns -ENOSPC. On memory allocation + * failure, returns -ENOMEM. + * + * Note that @end is treated as max when <= 0. This is to always allow + * using @start + N as @end as long as N is inside integer range. + * + * The user is responsible for exclusively synchronizing all operations + * which may modify @idr. However, read-only accesses such as idr_find() + * or iteration can be performed under RCU read lock provided the user + * destroys @ptr in RCU-safe way after removal from idr. + */ +int idr_alloc(struct idr *idr, void *ptr, int start, int end, gfp_t gfp_mask) +{ + int max = end > 0 ? end - 1 : INT_MAX; /* inclusive upper limit */ + struct idr_layer *pa[MAX_IDR_LEVEL + 1]; + int id; + + might_sleep_if(gfp_mask & __GFP_WAIT); + + /* sanity checks */ + if (WARN_ON_ONCE(start < 0)) + return -EINVAL; + if (unlikely(max < start)) + return -ENOSPC; + + /* allocate id */ + id = idr_get_empty_slot(idr, start, pa, gfp_mask, NULL); + if (unlikely(id < 0)) + return id; + if (unlikely(id > max)) + return -ENOSPC; + + idr_fill_slot(idr, ptr, id, pa); + return id; +} +EXPORT_SYMBOL_GPL(idr_alloc); static void idr_remove_warning(int id) { @@ -357,7 +525,7 @@ static void idr_remove_warning(int id) static void sub_remove(struct idr *idp, int shift, int id) { struct idr_layer *p = idp->top; - struct idr_layer **pa[MAX_IDR_LEVEL]; + struct idr_layer **pa[MAX_IDR_LEVEL + 1]; struct idr_layer ***paa = &pa[0]; struct idr_layer *to_free; int n; @@ -367,26 +535,26 @@ static void sub_remove(struct idr *idp, int shift, int id) while ((shift > 0) && p) { n = (id >> shift) & IDR_MASK; - __clear_bit(n, &p->bitmap); + __clear_bit(n, p->bitmap); *++paa = &p->ary[n]; p = p->ary[n]; shift -= IDR_BITS; } n = id & IDR_MASK; - if (likely(p != NULL && test_bit(n, &p->bitmap))){ - __clear_bit(n, &p->bitmap); + if (likely(p != NULL && test_bit(n, p->bitmap))) { + __clear_bit(n, p->bitmap); rcu_assign_pointer(p->ary[n], NULL); to_free = NULL; while(*paa && ! --((**paa)->count)){ if (to_free) - free_layer(to_free); + free_layer(idp, to_free); to_free = **paa; **paa-- = NULL; } if (!*paa) idp->layers = 0; if (to_free) - free_layer(to_free); + free_layer(idp, to_free); } else idr_remove_warning(id); } @@ -401,8 +569,9 @@ void idr_remove(struct idr *idp, int id) struct idr_layer *p; struct idr_layer *to_free; - /* Mask off upper bits we don't use for the search. */ - id &= MAX_IDR_MASK; + /* see comment in idr_find_slowpath() */ + if (WARN_ON_ONCE(id < 0)) + return; sub_remove(idp, (idp->layers - 1) * IDR_BITS, id); if (idp->top && idp->top->count == 1 && (idp->layers > 1) && @@ -417,8 +586,9 @@ void idr_remove(struct idr *idp, int id) p = idp->top->ary[0]; rcu_assign_pointer(idp->top, p); --idp->layers; - to_free->bitmap = to_free->count = 0; - free_layer(to_free); + to_free->count = 0; + bitmap_clear(to_free->bitmap, 0, IDR_SIZE); + free_layer(idp, to_free); } while (idp->id_free_cnt >= MAX_IDR_FREE) { p = get_from_free_list(idp); @@ -433,34 +603,21 @@ void idr_remove(struct idr *idp, int id) } EXPORT_SYMBOL(idr_remove); -/** - * idr_remove_all - remove all ids from the given idr tree - * @idp: idr handle - * - * idr_destroy() only frees up unused, cached idp_layers, but this - * function will remove all id mappings and leave all idp_layers - * unused. - * - * A typical clean-up sequence for objects stored in an idr tree will - * use idr_for_each() to free all objects, if necessay, then - * idr_remove_all() to remove all ids, and idr_destroy() to free - * up the cached idr_layers. - */ -void idr_remove_all(struct idr *idp) +void __idr_remove_all(struct idr *idp) { int n, id, max; int bt_mask; struct idr_layer *p; - struct idr_layer *pa[MAX_IDR_LEVEL]; + struct idr_layer *pa[MAX_IDR_LEVEL + 1]; struct idr_layer **paa = &pa[0]; n = idp->layers * IDR_BITS; p = idp->top; rcu_assign_pointer(idp->top, NULL); - max = 1 << n; + max = idr_max(idp->layers); id = 0; - while (id < max) { + while (id >= 0 && id <= max) { while (n > IDR_BITS && p) { n -= IDR_BITS; *paa++ = p; @@ -472,21 +629,32 @@ void idr_remove_all(struct idr *idp) /* Get the highest bit that the above add changed from 0->1. */ while (n < fls(id ^ bt_mask)) { if (p) - free_layer(p); + free_layer(idp, p); n += IDR_BITS; p = *--paa; } } idp->layers = 0; } -EXPORT_SYMBOL(idr_remove_all); +EXPORT_SYMBOL(__idr_remove_all); /** * idr_destroy - release all cached layers within an idr tree * @idp: idr handle + * + * Free all id mappings and all idp_layers. After this function, @idp is + * completely unused and can be freed / recycled. The caller is + * responsible for ensuring that no one else accesses @idp during or after + * idr_destroy(). + * + * A typical clean-up sequence for objects stored in an idr tree will use + * idr_for_each() to free all objects, if necessay, then idr_destroy() to + * free up the id mappings and cached idr_layers. */ void idr_destroy(struct idr *idp) { + __idr_remove_all(idp); + while (idp->id_free_cnt) { struct idr_layer *p = get_from_free_list(idp); kmem_cache_free(idr_layer_cache, p); @@ -494,32 +662,28 @@ void idr_destroy(struct idr *idp) } EXPORT_SYMBOL(idr_destroy); -/** - * idr_find - return pointer for given id - * @idp: idr handle - * @id: lookup key - * - * Return the pointer given the id it has been registered with. A %NULL - * return indicates that @id is not valid or you passed %NULL in - * idr_get_new(). - * - * This function can be called under rcu_read_lock(), given that the leaf - * pointers lifetimes are correctly managed. - */ -void *idr_find(struct idr *idp, int id) +void *idr_find_slowpath(struct idr *idp, int id) { int n; struct idr_layer *p; + /* + * If @id is negative, idr_find() used to ignore the sign bit and + * performed lookup with the rest of bits, which is weird and can + * lead to very obscure bugs. We're now returning NULL for all + * negative IDs but just in case somebody was depending on the sign + * bit being ignored, let's trigger WARN_ON_ONCE() so that they can + * be detected and fixed. WARN_ON_ONCE() can later be removed. + */ + if (WARN_ON_ONCE(id < 0)) + return NULL; + p = rcu_dereference_raw(idp->top); if (!p) return NULL; n = (p->layer+1) * IDR_BITS; - /* Mask off upper bits we don't use for the search. */ - id &= MAX_IDR_MASK; - - if (id >= (1 << n)) + if (id > idr_max(p->layer + 1)) return NULL; BUG_ON(n == 0); @@ -530,7 +694,7 @@ void *idr_find(struct idr *idp, int id) } return((void *)p); } -EXPORT_SYMBOL(idr_find); +EXPORT_SYMBOL(idr_find_slowpath); /** * idr_for_each - iterate through all stored pointers @@ -555,15 +719,15 @@ int idr_for_each(struct idr *idp, { int n, id, max, error = 0; struct idr_layer *p; - struct idr_layer *pa[MAX_IDR_LEVEL]; + struct idr_layer *pa[MAX_IDR_LEVEL + 1]; struct idr_layer **paa = &pa[0]; n = idp->layers * IDR_BITS; p = rcu_dereference_raw(idp->top); - max = 1 << n; + max = idr_max(idp->layers); id = 0; - while (id < max) { + while (id >= 0 && id <= max) { while (n > 0 && p) { n -= IDR_BITS; *paa++ = p; @@ -601,7 +765,7 @@ EXPORT_SYMBOL(idr_for_each); */ void *idr_get_next(struct idr *idp, int *nextidp) { - struct idr_layer *p, *pa[MAX_IDR_LEVEL]; + struct idr_layer *p, *pa[MAX_IDR_LEVEL + 1]; struct idr_layer **paa = &pa[0]; int id = *nextidp; int n, max; @@ -611,9 +775,9 @@ void *idr_get_next(struct idr *idp, int *nextidp) if (!p) return NULL; n = (p->layer + 1) * IDR_BITS; - max = 1 << n; + max = idr_max(p->layer + 1); - while (id < max) { + while (id >= 0 && id <= max) { while (n > 0 && p) { n -= IDR_BITS; *paa++ = p; @@ -625,7 +789,14 @@ void *idr_get_next(struct idr *idp, int *nextidp) return p; } - id += 1 << n; + /* + * Proceed to the next layer at the current level. Unlike + * idr_for_each(), @id isn't guaranteed to be aligned to + * layer boundary at this point and adding 1 << n may + * incorrectly skip IDs. Make sure we jump to the + * beginning of the next layer using round_up(). + */ + id = round_up(id + 1, 1 << n); while (n < fls(id)) { n += IDR_BITS; p = *--paa; @@ -653,14 +824,16 @@ void *idr_replace(struct idr *idp, void *ptr, int id) int n; struct idr_layer *p, *old_p; + /* see comment in idr_find_slowpath() */ + if (WARN_ON_ONCE(id < 0)) + return ERR_PTR(-EINVAL); + p = idp->top; if (!p) return ERR_PTR(-EINVAL); n = (p->layer+1) * IDR_BITS; - id &= MAX_IDR_MASK; - if (id >= (1 << n)) return ERR_PTR(-EINVAL); @@ -671,7 +844,7 @@ void *idr_replace(struct idr *idp, void *ptr, int id) } n = id & IDR_MASK; - if (unlikely(p == NULL || !test_bit(n, &p->bitmap))) + if (unlikely(p == NULL || !test_bit(n, p->bitmap))) return ERR_PTR(-ENOENT); old_p = p->ary[n]; @@ -780,7 +953,7 @@ EXPORT_SYMBOL(ida_pre_get); */ int ida_get_new_above(struct ida *ida, int starting_id, int *p_id) { - struct idr_layer *pa[MAX_IDR_LEVEL]; + struct idr_layer *pa[MAX_IDR_LEVEL + 1]; struct ida_bitmap *bitmap; unsigned long flags; int idr_id = starting_id / IDA_BITMAP_BITS; @@ -789,9 +962,9 @@ int ida_get_new_above(struct ida *ida, int starting_id, int *p_id) restart: /* get vacant slot */ - t = idr_get_empty_slot(&ida->idr, idr_id, pa); + t = idr_get_empty_slot(&ida->idr, idr_id, pa, 0, &ida->idr); if (t < 0) - return _idr_rc_to_errno(t); + return t == -ENOMEM ? -EAGAIN : t; if (t * IDA_BITMAP_BITS >= MAX_IDR_BIT) return -ENOSPC; @@ -851,25 +1024,6 @@ int ida_get_new_above(struct ida *ida, int starting_id, int *p_id) } EXPORT_SYMBOL(ida_get_new_above); -/** - * ida_get_new - allocate new ID - * @ida: idr handle - * @p_id: pointer to the allocated handle - * - * Allocate new ID. It should be called with any required locks. - * - * If memory is required, it will return %-EAGAIN, you should unlock - * and go back to the idr_pre_get() call. If the idr is full, it will - * return %-ENOSPC. - * - * @p_id returns a value in the range %0 ... %0x7fffffff. - */ -int ida_get_new(struct ida *ida, int *p_id) -{ - return ida_get_new_above(ida, 0, p_id); -} -EXPORT_SYMBOL(ida_get_new); - /** * ida_remove - remove the given ID * @ida: ida handle @@ -887,7 +1041,7 @@ void ida_remove(struct ida *ida, int id) /* clear full bits while looking up the leaf idr_layer */ while ((shift > 0) && p) { n = (idr_id >> shift) & IDR_MASK; - __clear_bit(n, &p->bitmap); + __clear_bit(n, p->bitmap); p = p->ary[n]; shift -= IDR_BITS; } @@ -896,7 +1050,7 @@ void ida_remove(struct ida *ida, int id) goto err; n = idr_id & IDR_MASK; - __clear_bit(n, &p->bitmap); + __clear_bit(n, p->bitmap); bitmap = (void *)p->ary[n]; if (!test_bit(offset, bitmap->bitmap)) @@ -905,7 +1059,7 @@ void ida_remove(struct ida *ida, int id) /* update bitmap and remove it if empty */ __clear_bit(offset, bitmap->bitmap); if (--bitmap->nr_busy == 0) { - __set_bit(n, &p->bitmap); /* to please idr_remove() */ + __set_bit(n, p->bitmap); /* to please idr_remove() */ idr_remove(&ida->idr, idr_id); free_bitmap(ida, bitmap); }