From be5b82dbfec2a900925da4437af3c60b61f4c53d Mon Sep 17 00:00:00 2001 From: Al Viro Date: Fri, 22 Apr 2016 15:06:44 -0400 Subject: make ext2_get_page() and friends work without external serialization Right now ext2_get_page() (and its analogues in a bunch of other filesystems) relies upon the directory being locked - the way it sets and tests Checked and Error bits would be racy without that. Switch to a slightly different scheme, _not_ setting Checked in case of failure. That way the logics becomes if Checked => OK else if Error => fail else if !validate => fail else => OK with validation setting Checked or Error on success and failure resp. and returning which one had happened. Equivalent to the current logics, but unlike the current logics not sensitive to the order of set_bit, test_bit getting reordered by CPU, etc. Signed-off-by: Al Viro --- fs/ufs/dir.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'fs/ufs') diff --git a/fs/ufs/dir.c b/fs/ufs/dir.c index 0b1457292734..4c07421453af 100644 --- a/fs/ufs/dir.c +++ b/fs/ufs/dir.c @@ -105,7 +105,7 @@ void ufs_set_link(struct inode *dir, struct ufs_dir_entry *de, } -static void ufs_check_page(struct page *page) +static bool ufs_check_page(struct page *page) { struct inode *dir = page->mapping->host; struct super_block *sb = dir->i_sb; @@ -143,7 +143,7 @@ static void ufs_check_page(struct page *page) goto Eend; out: SetPageChecked(page); - return; + return true; /* Too bad, we had an error */ @@ -180,8 +180,8 @@ Eend: "offset=%lu", dir->i_ino, (page->index<