From dd9086487c1bb38641bcfbe765422c7f0a1a8d95 Mon Sep 17 00:00:00 2001
From: Kent Overstreet <kent.overstreet@linux.dev>
Date: Thu, 20 Jun 2024 13:20:49 -0400
Subject: [PATCH] bcachefs: Fix I_NEW warning in race path in
bch2_inode_insert()
discard_new_inode() is the correct interface for tearing down an indoe
that was fully created but not made visible to other threads, but it
expects I_NEW to be set, which we don't use.
Reported-by: https://github.com/koverstreet/bcachefs/issues/690
Fixes: bcachefs: Fix race path in bch2_inode_insert()
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
---
fs/bcachefs/fs.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/fs/bcachefs/fs.c b/fs/bcachefs/fs.c
index 8314d3e1582d3..615ef8305c6eb 100644
--- a/fs/bcachefs/fs.c
+++ b/fs/bcachefs/fs.c
@@ -188,6 +188,12 @@ static struct bch_inode_info *bch2_inode_insert(struct bch_fs *c, struct bch_ino
BUG_ON(!old);
if (unlikely(old != inode)) {
+ /*
+ * bcachefs doesn't use I_NEW; we have no use for it since we
+ * only insert fully created inodes in the inode hash table. But
+ * discard_new_inode() expects it to be set...
+ */
+ inode->v.i_flags |= I_NEW;
discard_new_inode(&inode->v);
inode = old;
} else {
@@ -195,8 +201,10 @@ static struct bch_inode_info *bch2_inode_insert(struct bch_fs *c, struct bch_ino
list_add(&inode->ei_vfs_inode_list, &c->vfs_inodes_list);
mutex_unlock(&c->vfs_inodes_lock);
/*
- * we really don't want insert_inode_locked2() to be setting
- * I_NEW...
+ * Again, I_NEW makes no sense for bcachefs. This is only needed
+ * for clearing I_NEW, but since the inode was already fully
+ * created and initialized we didn't actually want
+ * inode_insert5() to set it for us.
*/
unlock_new_inode(&inode->v);
}
--
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