From: ruanmeisi <ruan.meisi@zte.com.cn>
Date: Tue, 25 Apr 2023 19:13:54 +0800
Subject: fuse: nlookup missing decrement in fuse_direntplus_link
Git-commit: b8bd342d50cbf606666488488f9fea374aceb2d5
Patch-mainline: v6.6-rc1
References: bsc#1215607
During our debugging of glusterfs, we found an Assertion failed error:
inode_lookup >= nlookup, which was caused by the nlookup value in the
kernel being greater than that in the FUSE file system.
The issue was introduced by fuse_direntplus_link, where in the function,
fuse_iget increments nlookup, and if d_splice_alias returns failure,
fuse_direntplus_link returns failure without decrementing nlookup
https://github.com/gluster/glusterfs/pull/4081
Signed-off-by: ruanmeisi <ruan.meisi@zte.com.cn>
Fixes: 0b05b18381ee ("fuse: implement NFS-like readdirplus support")
Cc: <stable@vger.kernel.org> # v3.9
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
[- patch dir.c instead of readdir.c as we don't have have commit
d123d8e1833c ("fuse: split out readdir.c")
- use ->lock from struct fuse_conn instead of struct struct fuse_inode]
Acked-by: Luís Henriques <lhenriques@suse.de>
---
fs/fuse/dir.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -1303,8 +1303,16 @@ retry:
dput(dentry);
dentry = alias;
}
- if (IS_ERR(dentry))
+ if (IS_ERR(dentry)) {
+ if (!IS_ERR(inode)) {
+ struct fuse_inode *fi = get_fuse_inode(inode);
+
+ spin_lock(&fc->lock);
+ fi->nlookup--;
+ spin_unlock(&fc->lock);
+ }
return PTR_ERR(dentry);
+ }
}
if (fc->readdirplus_auto)
set_bit(FUSE_I_INIT_RDPLUS, &get_fuse_inode(inode)->state);