From 62f945b6a7b8cda6d1f35941eb374276f7b8749a Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Fri, 17 Nov 2017 10:22:37 -0500 Subject: 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 --- mm/shmem.c | 22 ++++++++-------------- 1 file changed, 8 insertions(+), 14 deletions(-) (limited to 'mm/shmem.c') 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); -- cgit v1.2.3-58-ga151