f2fs: fix to add refcount once page is tagged PG_private
As Gao Xiang reported in bugzilla:
https://bugzilla.kernel.org/show_bug.cgi?id=202749
f2fs may skip pageout() due to incorrect page reference count.
The problem here is that MM defined the rule [1] very clearly that
once page was set with PG_private flag, we should increment the
refcount in that page, also main flows like pageout(), migrate_page()
will assume there is one additional page reference count if
page_has_private() returns true.
But currently, f2fs won't add/del refcount when changing PG_private
flag. Anyway, f2fs should follow MM's rule to make MM's related flows
running as expected.
[1] https://lore.kernel.org/lkml/[email protected]/
Reported-by: Gao Xiang <[email protected]>
Signed-off-by: Chao Yu <[email protected]>
Signed-off-by: Jaegeuk Kim <[email protected]>
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index e730c33..aa7fe79 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -191,8 +191,7 @@ void f2fs_register_inmem_page(struct inode *inode, struct page *page)
f2fs_trace_pid(page);
- set_page_private(page, (unsigned long)ATOMIC_WRITTEN_PAGE);
- SetPagePrivate(page);
+ f2fs_set_page_private(page, (unsigned long)ATOMIC_WRITTEN_PAGE);
new = f2fs_kmem_cache_alloc(inmem_entry_slab, GFP_NOFS);
@@ -280,8 +279,7 @@ static int __revoke_inmem_pages(struct inode *inode,
ClearPageUptodate(page);
clear_cold_data(page);
}
- set_page_private(page, 0);
- ClearPagePrivate(page);
+ f2fs_clear_page_private(page);
f2fs_put_page(page, 1);
list_del(&cur->list);
@@ -370,8 +368,7 @@ void f2fs_drop_inmem_page(struct inode *inode, struct page *page)
kmem_cache_free(inmem_entry_slab, cur);
ClearPageUptodate(page);
- set_page_private(page, 0);
- ClearPagePrivate(page);
+ f2fs_clear_page_private(page);
f2fs_put_page(page, 0);
trace_f2fs_commit_inmem_page(page, INMEM_INVALIDATE);
