diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/idr.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/lib/idr.c b/lib/idr.c index 44ab3b2a4eb..21e12af1f23 100644 --- a/lib/idr.c +++ b/lib/idr.c @@ -456,7 +456,8 @@ EXPORT_SYMBOL(idr_destroy); * return indicates that @id is not valid or you passed %NULL in * idr_get_new(). * - * The caller must serialize idr_find() vs idr_get_new() and idr_remove(). + * 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) { @@ -464,7 +465,7 @@ void *idr_find(struct idr *idp, int id) struct idr_layer *p; n = idp->layers * IDR_BITS; - p = idp->top; + p = rcu_dereference(idp->top); /* Mask off upper bits we don't use for the search. */ id &= MAX_ID_MASK; @@ -474,7 +475,7 @@ void *idr_find(struct idr *idp, int id) while (n > 0 && p) { n -= IDR_BITS; - p = p->ary[(id >> n) & IDR_MASK]; + p = rcu_dereference(p->ary[(id >> n) & IDR_MASK]); } return((void *)p); } @@ -507,7 +508,7 @@ int idr_for_each(struct idr *idp, struct idr_layer **paa = &pa[0]; n = idp->layers * IDR_BITS; - p = idp->top; + p = rcu_dereference(idp->top); max = 1 << n; id = 0; @@ -515,7 +516,7 @@ int idr_for_each(struct idr *idp, while (n > 0 && p) { n -= IDR_BITS; *paa++ = p; - p = p->ary[(id >> n) & IDR_MASK]; + p = rcu_dereference(p->ary[(id >> n) & IDR_MASK]); } if (p) { |