linux-kernel - [PATCH] fuse: always revalidate rename target dentry

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Date:   Wed, 28 Sep 2022 20:19:34 +0800
From:   Jiachen Zhang <zhangjiachen.jaycee@...edance.com>
To:     Miklos Szeredi <miklos@...redi.hu>
Cc:     linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
        Jiachen Zhang <zhangjiachen.jaycee@...edance.com>,
        Zhang Tianci <zhangtianci.1997@...edance.com>
Subject: [PATCH] fuse: always revalidate rename target dentry

The previous commit df8629af2934 ("fuse: always revalidate if exclusive
create") ensures that the dentries are revalidated on O_EXCL creates. This
commit complements it by also performing revalidation for rename target
dentries. Otherwise, a rename target file that only exists in kernel dentry
cache but not in the filesystem may result in an EEXIST.

Signed-off-by: Jiachen Zhang <zhangjiachen.jaycee@...edance.com>
Signed-off-by: Zhang Tianci <zhangtianci.1997@...edance.com>
---
 fs/fuse/dir.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index b585b04e815e..a453fc57ce4f 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -214,7 +214,7 @@ static int fuse_dentry_revalidate(struct dentry *entry, unsigned int flags)
 	if (inode && fuse_is_bad(inode))
 		goto invalid;
 	else if (time_before64(fuse_dentry_time(entry), get_jiffies_64()) ||
-		 (flags & (LOOKUP_EXCL | LOOKUP_REVAL))) {
+		 (flags & (LOOKUP_EXCL | LOOKUP_REVAL | LOOKUP_RENAME_TARGET))) {
 		struct fuse_entry_out outarg;
 		FUSE_ARGS(args);
 		struct fuse_forget_link *forget;
-- 
2.20.1