From: Vladimir Zapolskiy <vladimir@tuxera.com>
To: Gao Xiang <xiang@kernel.org>, Chao Yu <chao@kernel.org>
Cc: linux-fsdevel@vger.kernel.org, linux-erofs@lists.ozlabs.org,
Matthew Wilcox <willy@infradead.org>,
Anton Altaparmakov <anton@tuxera.com>
Subject: [PATCH 3/3] erofs: remove void tagging/untagging of workgroup pointers
Date: Thu, 2 Jan 2020 14:01:18 +0200 [thread overview]
Message-ID: <20200102120118.14979-4-vladimir@tuxera.com> (raw)
In-Reply-To: <20200102120118.14979-1-vladimir@tuxera.com>
Because workgroup pointers inserted to a radix tree are always tagged with
a single value of 0, it is possible to remove tagging and untagging of the
pointers completely.
Signed-off-by: Vladimir Zapolskiy <vladimir@tuxera.com>
---
fs/erofs/utils.c | 9 ++-------
1 file changed, 2 insertions(+), 7 deletions(-)
diff --git a/fs/erofs/utils.c b/fs/erofs/utils.c
index 7b47c56b89b7..fddc5059c930 100644
--- a/fs/erofs/utils.c
+++ b/fs/erofs/utils.c
@@ -68,8 +68,6 @@ struct erofs_workgroup *erofs_find_workgroup(struct super_block *sb,
rcu_read_lock();
grp = radix_tree_lookup(&sbi->workstn_tree, index);
if (grp) {
- grp = xa_untag_pointer(grp);
-
if (erofs_workgroup_get(grp)) {
/* prefer to relax rcu read side */
rcu_read_unlock();
@@ -101,8 +99,6 @@ int erofs_register_workgroup(struct super_block *sb,
sbi = EROFS_SB(sb);
xa_lock(&sbi->workstn_tree);
- grp = xa_tag_pointer(grp, 0);
-
/*
* Bump up reference count before making this workgroup
* visible to other users in order to avoid potential UAF
@@ -173,8 +169,7 @@ static bool erofs_try_to_release_workgroup(struct erofs_sb_info *sbi,
* however in order to avoid some race conditions, add a
* DBG_BUGON to observe this in advance.
*/
- DBG_BUGON(xa_untag_pointer(radix_tree_delete(&sbi->workstn_tree,
- grp->index)) != grp);
+ DBG_BUGON(radix_tree_delete(&sbi->workstn_tree, grp->index) != grp);
/*
* If managed cache is on, last refcount should indicate
@@ -199,7 +194,7 @@ static unsigned long erofs_shrink_workstation(struct erofs_sb_info *sbi,
batch, first_index, PAGEVEC_SIZE);
for (i = 0; i < found; ++i) {
- struct erofs_workgroup *grp = xa_untag_pointer(batch[i]);
+ struct erofs_workgroup *grp = batch[i];
first_index = grp->index + 1;
--
2.20.1
next prev parent reply other threads:[~2020-01-02 12:31 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-02 12:01 [PATCH 0/3] erofs: remove tags of pointers stored in a radix tree Vladimir Zapolskiy
2020-01-02 12:01 ` [PATCH 1/3] erofs: remove unused tag argument while finding a workgroup Vladimir Zapolskiy
2020-01-02 12:01 ` [PATCH 2/3] erofs: remove unused tag argument while registering " Vladimir Zapolskiy
2020-01-02 12:01 ` Vladimir Zapolskiy [this message]
2020-01-02 12:55 ` [PATCH 0/3] erofs: remove tags of pointers stored in a radix tree Gao Xiang
2020-01-03 7:08 ` Chao Yu
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