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authorKristian Hoegsberg <krh@redhat.com>2007-07-15 23:37:24 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-07-16 09:05:34 -0700
commit23936cc0b5d89619c34c2dab11d8cf3d6f7ca028 (patch)
tree506ec36cc37d3bc7dbf0ca68d1b271f9247fa458 /lib/idr.c
parent96d7fa421e6424ad9ef6d1d039375dc2edb63fe8 (diff)
downloadlinux-2.6.38-lt-ux500-23936cc0b5d89619c34c2dab11d8cf3d6f7ca028.tar.gz
lib: add idr_remove_all
Remove all ids from the given idr tree. 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. Signed-off-by: Kristian Hoegsberg <krh@redhat.com> Cc: Tejun Heo <htejun@gmail.com> Cc: Dave Airlie <airlied@linux.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib/idr.c')
-rw-r--r--lib/idr.c47
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
*/