[PATCH v6 41/99] shmem: Convert replace to XArray
From: Matthew Wilcox <willy@infradead.org>
Date: 2018-01-17 20:21:05
Also in:
cgroups, intel-gfx, linux-f2fs-devel, linux-fsdevel, linux-iommu, linux-mm, linux-remoteproc, linux-s390, linux-usb, linux-xfs, lkml
Subsystem:
memory management, the rest, tmpfs (shmem filesystem) · Maintainers:
Andrew Morton, Linus Torvalds, Hugh Dickins
From: Matthew Wilcox <redacted> shmem_radix_tree_replace() is renamed to shmem_xa_replace() and converted to use the XArray API. Signed-off-by: Matthew Wilcox <redacted> --- mm/shmem.c | 22 ++++++++-------------- 1 file changed, 8 insertions(+), 14 deletions(-)
diff --git a/mm/shmem.c b/mm/shmem.c
index c5731bb954a1..fad6c9e7402e 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c@@ -321,24 +321,20 @@ 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_xa_replace(struct address_space *mapping, pgoff_t index, void *expected, void *replacement) { - struct radix_tree_node *node; - void **pslot; + XA_STATE(xas, &mapping->pages, index); void *item; VM_BUG_ON(!expected); VM_BUG_ON(!replacement); - item = __radix_tree_lookup(&mapping->pages, index, &node, &pslot); - if (!item) - return -ENOENT; + item = xas_load(&xas); if (item != expected) return -ENOENT; - __radix_tree_replace(&mapping->pages, node, pslot, - replacement, NULL); + xas_store(&xas, replacement); return 0; }
@@ -605,8 +601,7 @@ static int shmem_add_to_page_cache(struct page *page, } else if (!expected) { error = radix_tree_insert(&mapping->pages, index, page); } else { - error = shmem_radix_tree_replace(mapping, index, expected, - page); + error = shmem_xa_replace(mapping, index, expected, page); } if (!error) {
@@ -635,7 +630,7 @@ static void shmem_delete_from_page_cache(struct page *page, void *radswap) VM_BUG_ON_PAGE(PageCompound(page), page); xa_lock_irq(&mapping->pages); - error = shmem_radix_tree_replace(mapping, page->index, page, radswap); + error = shmem_xa_replace(mapping, page->index, page, radswap); page->mapping = NULL; mapping->nrpages--; __dec_node_page_state(page, NR_FILE_PAGES);
@@ -1550,8 +1545,7 @@ 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->pages); - error = shmem_radix_tree_replace(swap_mapping, swap_index, oldpage, - newpage); + error = shmem_xa_replace(swap_mapping, swap_index, oldpage, newpage); if (!error) { __inc_node_page_state(newpage, NR_FILE_PAGES); __dec_node_page_state(oldpage, NR_FILE_PAGES);
--
2.15.1