nfsd: initialize i_private before d_add

A process could race in an open and attempt to read one of these files
before i_private is initialized, and get a spurious error.

Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This commit is contained in:
J. Bruce Fields 2019-08-15 16:18:26 -04:00
parent dc46bba709
commit bebd699716

View File

@ -1171,13 +1171,17 @@ static struct inode *nfsd_get_inode(struct super_block *sb, umode_t mode)
return inode;
}
static int __nfsd_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
static int __nfsd_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode, struct nfsdfs_client *ncl)
{
struct inode *inode;
inode = nfsd_get_inode(dir->i_sb, mode);
if (!inode)
return -ENOMEM;
if (ncl) {
inode->i_private = ncl;
kref_get(&ncl->cl_ref);
}
d_add(dentry, inode);
inc_nlink(dir);
fsnotify_mkdir(dir, dentry);
@ -1194,13 +1198,9 @@ static struct dentry *nfsd_mkdir(struct dentry *parent, struct nfsdfs_client *nc
dentry = d_alloc_name(parent, name);
if (!dentry)
goto out_err;
ret = __nfsd_mkdir(d_inode(parent), dentry, S_IFDIR | 0600);
ret = __nfsd_mkdir(d_inode(parent), dentry, S_IFDIR | 0600, ncl);
if (ret)
goto out_err;
if (ncl) {
d_inode(dentry)->i_private = ncl;
kref_get(&ncl->cl_ref);
}
out:
inode_unlock(dir);
return dentry;