NFSv4: Fix an Oops during delegation callbacks

If the server sends a CB_GETATTR or a CB_RECALL while the filesystem is
being unmounted, then we can Oops when releasing the inode in
nfs4_callback_getattr() and nfs4_callback_recall().

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
This commit is contained in:
Trond Myklebust 2018-11-13 16:37:54 -05:00
parent e3d5e573a5
commit e39d8a186e
2 changed files with 11 additions and 4 deletions

View File

@ -66,7 +66,7 @@ __be32 nfs4_callback_getattr(void *argp, void *resp,
out_iput:
rcu_read_unlock();
trace_nfs4_cb_getattr(cps->clp, &args->fh, inode, -ntohl(res->status));
iput(inode);
nfs_iput_and_deactive(inode);
out:
dprintk("%s: exit with status = %d\n", __func__, ntohl(res->status));
return res->status;
@ -108,7 +108,7 @@ __be32 nfs4_callback_recall(void *argp, void *resp,
}
trace_nfs4_cb_recall(cps->clp, &args->fh, inode,
&args->stateid, -ntohl(res));
iput(inode);
nfs_iput_and_deactive(inode);
out:
dprintk("%s: exit with status = %d\n", __func__, ntohl(res));
return res;

View File

@ -850,16 +850,23 @@ nfs_delegation_find_inode_server(struct nfs_server *server,
const struct nfs_fh *fhandle)
{
struct nfs_delegation *delegation;
struct inode *res = NULL;
struct inode *freeme, *res = NULL;
list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
spin_lock(&delegation->lock);
if (delegation->inode != NULL &&
nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) {
res = igrab(delegation->inode);
freeme = igrab(delegation->inode);
if (freeme && nfs_sb_active(freeme->i_sb))
res = freeme;
spin_unlock(&delegation->lock);
if (res != NULL)
return res;
if (freeme) {
rcu_read_unlock();
iput(freeme);
rcu_read_lock();
}
return ERR_PTR(-EAGAIN);
}
spin_unlock(&delegation->lock);