[PATCH v8 47/63] shmem: Convert find_swap_entry to XArray

From: Matthew Wilcox
Date: Tue Mar 06 2018 - 14:32:55 EST


From: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>

This is a 1:1 conversion.

Signed-off-by: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
---
mm/shmem.c | 23 +++++++++++------------
1 file changed, 11 insertions(+), 12 deletions(-)

diff --git a/mm/shmem.c b/mm/shmem.c
index 0af8a439dfad..49f42dc9e1dc 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1076,28 +1076,27 @@ static void shmem_evict_inode(struct inode *inode)
clear_inode(inode);
}

-static unsigned long find_swap_entry(struct radix_tree_root *root, void *item)
+static unsigned long find_swap_entry(struct xarray *xa, void *item)
{
- struct radix_tree_iter iter;
- void **slot;
- unsigned long found = -1;
+ XA_STATE(xas, xa, 0);
unsigned int checked = 0;
+ void *entry;

rcu_read_lock();
- radix_tree_for_each_slot(slot, root, &iter, 0) {
- if (*slot == item) {
- found = iter.index;
+ xas_for_each(&xas, entry, ULONG_MAX) {
+ if (xas_retry(&xas, entry))
+ continue;
+ if (entry == item)
break;
- }
checked++;
- if ((checked % 4096) != 0)
+ if ((checked % XA_CHECK_SCHED) != 0)
continue;
- slot = radix_tree_iter_resume(slot, &iter);
+ xas_pause(&xas);
cond_resched_rcu();
}
-
rcu_read_unlock();
- return found;
+
+ return xas_invalid(&xas) ? -1 : xas.xa_index;
}

/*
--
2.16.1