fuse: nlookup missing decrement in fuse_direntplus_link

commit b8bd342d50cbf606666488488f9fea374aceb2d5 upstream.

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: 0b05b18381 ("fuse: implement NFS-like readdirplus support")
Cc: <stable@vger.kernel.org> # v3.9
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
ruanmeisi 2023-04-25 19:13:54 +08:00 committed by Greg Kroah-Hartman
parent 0e918d7c00
commit b0d236e3af

View File

@ -238,8 +238,16 @@ 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(&fi->lock);
fi->nlookup--;
spin_unlock(&fi->lock);
}
return PTR_ERR(dentry);
}
}
if (fc->readdirplus_auto)
set_bit(FUSE_I_INIT_RDPLUS, &get_fuse_inode(inode)->state);