diff options
Diffstat (limited to 'lib/idr.c')
| -rw-r--r-- | lib/idr.c | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/lib/idr.c b/lib/idr.c index d29da6159da..5ca67b3cfd3 100644 --- a/lib/idr.c +++ b/lib/idr.c @@ -391,6 +391,53 @@ 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) +{ + 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 && !error) { + while (n > IDR_BITS && p) { + n -= IDR_BITS; + *paa++ = p; + p = p->ary[(id >> n) & IDR_MASK]; + } + + id += 1 << n; + while (n < fls(id)) { + if (p) { + memset(p, 0, sizeof *p); + free_layer(idp, p); + } + n += IDR_BITS; + p = *--paa; + } + } + idp->top = NULL; + idp->layers = 0; +} +EXPORT_SYMBOL(idr_remove_all); + +/** * idr_destroy - release all cached layers within an idr tree * idp: idr handle */ |