radix-tree,shmem: introduce radix_tree_iter_next()
shmem likes to occasionally drop the lock, schedule, then reacqire the
lock and continue with the iteration from the last place it left off.
This is currently done with a pretty ugly goto. Introduce
radix_tree_iter_next() and use it throughout shmem.c.
[koct9i@gmail.com: fix bug in radix_tree_iter_next() for tagged iteration]
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/shmem.c b/mm/shmem.c
index 91c0dad..9428c51 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -376,7 +376,6 @@
rcu_read_lock();
-restart:
radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, start) {
if (iter.index >= end)
break;
@@ -393,8 +392,7 @@
if (need_resched()) {
cond_resched_rcu();
- start = iter.index + 1;
- goto restart;
+ slot = radix_tree_iter_next(&iter);
}
}
@@ -1944,7 +1942,6 @@
start = 0;
rcu_read_lock();
-restart:
radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, start) {
page = radix_tree_deref_slot(slot);
if (!page || radix_tree_exception(page)) {
@@ -1961,8 +1958,7 @@
if (need_resched()) {
cond_resched_rcu();
- start = iter.index + 1;
- goto restart;
+ slot = radix_tree_iter_next(&iter);
}
}
rcu_read_unlock();
@@ -1999,7 +1995,6 @@
start = 0;
rcu_read_lock();
-restart:
radix_tree_for_each_tagged(slot, &mapping->page_tree, &iter,
start, SHMEM_TAG_PINNED) {
@@ -2033,8 +2028,7 @@
continue_resched:
if (need_resched()) {
cond_resched_rcu();
- start = iter.index + 1;
- goto restart;
+ slot = radix_tree_iter_next(&iter);
}
}
rcu_read_unlock();