diff options
| -rw-r--r-- | include/linux/idr.h | 2 | ||||
| -rw-r--r-- | lib/idr.c | 55 |
2 files changed, 57 insertions, 0 deletions
diff --git a/include/linux/idr.h b/include/linux/idr.h index 915572fa030b..8442c0bffc06 100644 --- a/include/linux/idr.h +++ b/include/linux/idr.h @@ -78,6 +78,8 @@ void *idr_find(struct idr *idp, int id); int idr_pre_get(struct idr *idp, gfp_t gfp_mask); int idr_get_new(struct idr *idp, void *ptr, int *id); int idr_get_new_above(struct idr *idp, void *ptr, int starting_id, int *id); +int idr_for_each(struct idr *idp, + int (*fn)(int id, void *p, void *data), void *data); void *idr_replace(struct idr *idp, void *ptr, int id); void idr_remove(struct idr *idp, int id); void idr_destroy(struct idr *idp); diff --git a/lib/idr.c b/lib/idr.c index b98f01a2eb94..d29da6159dae 100644 --- a/lib/idr.c +++ b/lib/idr.c @@ -437,6 +437,61 @@ void *idr_find(struct idr *idp, int id) EXPORT_SYMBOL(idr_find); /** + * idr_for_each - iterate through all stored pointers + * @idp: idr handle + * @fn: function to be called for each pointer + * @data: data passed back to callback function + * + * Iterate over the pointers registered with the given idr. The + * callback function will be called for each pointer currently + * registered, passing the id, the pointer and the data pointer passed + * to this function. It is not safe to modify the idr tree while in + * the callback, so functions such as idr_get_new and idr_remove are + * not allowed. + * + * We check the return of @fn each time. If it returns anything other + * than 0, we break out and return that value. + * + * The caller must serialize idr_for_each() vs idr_get_new() and idr_remove(). + */ +int idr_for_each(struct idr *idp, + int (*fn)(int id, void *p, void *data), void *data) +{ + int n, id, max, error = 0; + struct idr_layer *p; + struct idr_layer *pa[MAX_LEVEL]; + struct idr_layer **paa = &pa[0]; + + n = idp->layers * IDR_BITS; + p = idp->top; + max = 1 << n; + + id = 0; + while (id < max) { + while (n > 0 && p) { + n -= IDR_BITS; + *paa++ = p; + p = p->ary[(id >> n) & IDR_MASK]; + } + + if (p) { + error = fn(id, (void *)p, data); + if (error) + break; + } + + id += 1 << n; + while (n < fls(id)) { + n += IDR_BITS; + p = *--paa; + } + } + + return error; +} +EXPORT_SYMBOL(idr_for_each); + +/** * idr_replace - replace pointer for given id * @idp: idr handle * @ptr: pointer you want associated with the id |