[v6,48/99] shmem: Convert shmem_free_swap to XArray
From: Matthew Wilcox <willy@infradead.org>
Date: 2018-01-17 20:21:12
Also in:
cgroups, intel-gfx, linux-f2fs-devel, linux-fsdevel, linux-iommu, linux-mm, linux-remoteproc, linux-s390, linux-sh, linux-xfs, lkml
Subsystem:
memory management, the rest, tmpfs (shmem filesystem) · Maintainers:
Andrew Morton, Linus Torvalds, Hugh Dickins
From: Matthew Wilcox <redacted> This is a perfect use for xa_cmpxchg(). Note the use of 0 for GFP flags; we won't be allocating memory. Signed-off-by: Matthew Wilcox <redacted> --- mm/shmem.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-)
diff --git a/mm/shmem.c b/mm/shmem.c
index e8233cb7ab5c..5a2226e06f8c 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c@@ -635,16 +635,13 @@ static void shmem_delete_from_page_cache(struct page *page, void *radswap) } /* - * Remove swap entry from radix tree, free the swap and its page cache. + * Remove swap entry from page cache, free the swap and its page cache. */ static int shmem_free_swap(struct address_space *mapping, pgoff_t index, void *radswap) { - void *old; + void *old = xa_cmpxchg(&mapping->pages, index, radswap, NULL, 0); - xa_lock_irq(&mapping->pages); - old = radix_tree_delete_item(&mapping->pages, index, radswap); - xa_unlock_irq(&mapping->pages); if (old != radswap) return -ENOENT; free_swap_and_cache(radix_to_swp_entry(radswap));