This is close to a 1:1 replacement of radix tree APIs with their XArray
equivalents. It would be possible to optimise nilfs_copy_back_pages(),
but that doesn't seem to be in the performance path. Also, I think
it has a pre-existing bug, and I've added a note to that effect in the
source code.
Signed-off-by: Matthew Wilcox <willy@xxxxxxxxxxxxx>
---
fs/nilfs2/btnode.c | 26 +++++++++-----------------
fs/nilfs2/page.c | 29 +++++++++++++----------------
2 files changed, 22 insertions(+), 33 deletions(-)
diff --git a/fs/nilfs2/btnode.c b/fs/nilfs2/btnode.c
index dec98cab729d..e9fcffb3a15c 100644
--- a/fs/nilfs2/btnode.c
+++ b/fs/nilfs2/btnode.c
@@ -177,24 +177,18 @@ int nilfs_btnode_prepare_change_key(struct address_space *btnc,
ctxt->newbh = NULL;
if (inode->i_blkbits == PAGE_SHIFT) {
- lock_page(obh->b_page);
- /*
- * We cannot call radix_tree_preload for the kernels older
- * than 2.6.23, because it is not exported for modules.
- */
+ struct page *opage = obh->b_page;
+ lock_page(opage);
retry:
- err = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
- if (err)
- goto failed_unlock;
/* BUG_ON(oldkey != obh->b_page->index); */
- if (unlikely(oldkey != obh->b_page->index))
- NILFS_PAGE_BUG(obh->b_page,
+ if (unlikely(oldkey != opage->index))
+ NILFS_PAGE_BUG(opage,
"invalid oldkey %lld (newkey=%lld)",
(unsigned long long)oldkey,
(unsigned long long)newkey);
xa_lock_irq(&btnc->i_pages);
- err = radix_tree_insert(&btnc->i_pages, newkey, obh->b_page);
+ err = __xa_insert(&btnc->i_pages, newkey, opage, GFP_NOFS);
xa_unlock_irq(&btnc->i_pages);
/*
* Note: page->index will not change to newkey until
@@ -202,7 +196,6 @@ int nilfs_btnode_prepare_change_key(struct address_space *btnc,
* To protect the page in intermediate state, the page lock
* is held.
*/
- radix_tree_preload_end();
if (!err)
return 0;
else if (err != -EEXIST)
@@ -212,7 +205,7 @@ int nilfs_btnode_prepare_change_key(struct address_space *btnc,
if (!err)
goto retry;
/* fallback to copy mode */
- unlock_page(obh->b_page);
+ unlock_page(opage);
}
nbh = nilfs_btnode_create_block(btnc, newkey);
@@ -252,9 +245,8 @@ void nilfs_btnode_commit_change_key(struct address_space *btnc,
mark_buffer_dirty(obh);
xa_lock_irq(&btnc->i_pages);
- radix_tree_delete(&btnc->i_pages, oldkey);
- radix_tree_tag_set(&btnc->i_pages, newkey,
- PAGECACHE_TAG_DIRTY);
+ __xa_erase(&btnc->i_pages, oldkey);
+ __xa_set_tag(&btnc->i_pages, newkey, PAGECACHE_TAG_DIRTY);
xa_unlock_irq(&btnc->i_pages);
opage->index = obh->b_blocknr = newkey;
@@ -284,7 +276,7 @@ void nilfs_btnode_abort_change_key(struct address_space *btnc,
if (nbh == NULL) { /* blocksize == pagesize */
xa_lock_irq(&btnc->i_pages);
- radix_tree_delete(&btnc->i_pages, newkey);
+ __xa_erase(&btnc->i_pages, newkey);
xa_unlock_irq(&btnc->i_pages);
unlock_page(ctxt->bh->b_page);
} else
diff --git a/fs/nilfs2/page.c b/fs/nilfs2/page.c
index 4cb850a6f1c2..8384473b98b8 100644
--- a/fs/nilfs2/page.c
+++ b/fs/nilfs2/page.c
@@ -298,7 +298,7 @@ int nilfs_copy_dirty_pages(struct address_space *dmap,
* @dmap: destination page cache
* @smap: source page cache
*
- * No pages must no be added to the cache during this process.
+ * No pages must be added to the cache during this process.
* This must be ensured by the caller.
*/
void nilfs_copy_back_pages(struct address_space *dmap,
@@ -307,7 +307,6 @@ void nilfs_copy_back_pages(struct address_space *dmap,
struct pagevec pvec;
unsigned int i, n;
pgoff_t index = 0;
- int err;
pagevec_init(&pvec);
repeat:
@@ -322,35 +321,34 @@ void nilfs_copy_back_pages(struct address_space *dmap,
lock_page(page);
dpage = find_lock_page(dmap, offset);
if (dpage) {
- /* override existing page on the destination cache */
+ /* overwrite existing page in the destination cache */
WARN_ON(PageDirty(dpage));
nilfs_copy_page(dpage, page, 0);
unlock_page(dpage);
put_page(dpage);
+ /* Do we not need to remove page from smap here? */
} else {
- struct page *page2;
+ struct page *p;
/* move the page to the destination cache */
xa_lock_irq(&smap->i_pages);
- page2 = radix_tree_delete(&smap->i_pages, offset);
- WARN_ON(page2 != page);
-
+ p = __xa_erase(&smap->i_pages, offset);
+ WARN_ON(page != p);
smap->nrpages--;
xa_unlock_irq(&smap->i_pages);
xa_lock_irq(&dmap->i_pages);
- err = radix_tree_insert(&dmap->i_pages, offset, page);
- if (unlikely(err < 0)) {
- WARN_ON(err == -EEXIST);
+ p = __xa_store(&dmap->i_pages, offset, page, GFP_NOFS);
+ if (unlikely(p)) {
+ /* Probably -ENOMEM */
page->mapping = NULL;
- put_page(page); /* for cache */
+ put_page(page);
} else {
page->mapping = dmap;
dmap->nrpages++;
if (PageDirty(page))
- radix_tree_tag_set(&dmap->i_pages,
- offset,
- PAGECACHE_TAG_DIRTY);
+ __xa_set_tag(&dmap->i_pages, offset,
+ PAGECACHE_TAG_DIRTY);
}
xa_unlock_irq(&dmap->i_pages);
}
@@ -476,8 +474,7 @@ int __nilfs_clear_page_dirty(struct page *page)
if (mapping) {
xa_lock_irq(&mapping->i_pages);
if (test_bit(PG_dirty, &page->flags)) {
- radix_tree_tag_clear(&mapping->i_pages,
- page_index(page),
+ __xa_clear_tag(&mapping->i_pages, page_index(page),
PAGECACHE_TAG_DIRTY);
xa_unlock_irq(&mapping->i_pages);
return clear_page_dirty_for_io(page);
--
2.17.1
