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authorMatthew Wilcox <willy@infradead.org>2017-11-17 10:22:37 -0500
committerMatthew Wilcox <willy@infradead.org>2018-10-21 10:46:39 -0400
commit62f945b6a7b8cda6d1f35941eb374276f7b8749a (patch)
treeb9d69736724e6312aaa43c2dd2eb32b447b28a6d /mm/shmem.c
parent10bbd235859bf483f9a8a4ebe95463d700bae394 (diff)
downloadlwn-62f945b6a7b8cda6d1f35941eb374276f7b8749a.tar.gz
lwn-62f945b6a7b8cda6d1f35941eb374276f7b8749a.zip
shmem: Convert shmem_radix_tree_replace to XArray
Rename shmem_radix_tree_replace() to shmem_replace_entry() and convert it to use the XArray API. Signed-off-by: Matthew Wilcox <willy@infradead.org>
Diffstat (limited to 'mm/shmem.c')
-rw-r--r--mm/shmem.c22
1 files changed, 8 insertions, 14 deletions
diff --git a/mm/shmem.c b/mm/shmem.c
index c1062760fe41..5697c8fecdfc 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -322,24 +322,20 @@ void shmem_uncharge(struct inode *inode, long pages)
}
/*
- * Replace item expected in radix tree by a new item, while holding tree lock.
+ * Replace item expected in xarray by a new item, while holding xa_lock.
*/
-static int shmem_radix_tree_replace(struct address_space *mapping,
+static int shmem_replace_entry(struct address_space *mapping,
pgoff_t index, void *expected, void *replacement)
{
- struct radix_tree_node *node;
- void __rcu **pslot;
+ XA_STATE(xas, &mapping->i_pages, index);
void *item;
VM_BUG_ON(!expected);
VM_BUG_ON(!replacement);
- item = __radix_tree_lookup(&mapping->i_pages, index, &node, &pslot);
- if (!item)
- return -ENOENT;
+ item = xas_load(&xas);
if (item != expected)
return -ENOENT;
- __radix_tree_replace(&mapping->i_pages, node, pslot,
- replacement, NULL);
+ xas_store(&xas, replacement);
return 0;
}
@@ -624,8 +620,7 @@ static int shmem_add_to_page_cache(struct page *page,
} else if (!expected) {
error = radix_tree_insert(&mapping->i_pages, index, page);
} else {
- error = shmem_radix_tree_replace(mapping, index, expected,
- page);
+ error = shmem_replace_entry(mapping, index, expected, page);
}
if (!error) {
@@ -654,7 +649,7 @@ static void shmem_delete_from_page_cache(struct page *page, void *radswap)
VM_BUG_ON_PAGE(PageCompound(page), page);
xa_lock_irq(&mapping->i_pages);
- error = shmem_radix_tree_replace(mapping, page->index, page, radswap);
+ error = shmem_replace_entry(mapping, page->index, page, radswap);
page->mapping = NULL;
mapping->nrpages--;
__dec_node_page_state(page, NR_FILE_PAGES);
@@ -1578,8 +1573,7 @@ static int shmem_replace_page(struct page **pagep, gfp_t gfp,
* a nice clean interface for us to replace oldpage by newpage there.
*/
xa_lock_irq(&swap_mapping->i_pages);
- error = shmem_radix_tree_replace(swap_mapping, swap_index, oldpage,
- newpage);
+ error = shmem_replace_entry(swap_mapping, swap_index, oldpage, newpage);
if (!error) {
__inc_node_page_state(newpage, NR_FILE_PAGES);
__dec_node_page_state(oldpage, NR_FILE_PAGES);