4.19-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit e39d8a186ed002854196668cb7562ffdfbc6d379 ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- fs/nfs/callback_proc.c | 4 ++-- fs/nfs/delegation.c | 11 +++++++++-- 2 files changed, 11 insertions(+), 4 deletions(-)
diff --git a/fs/nfs/callback_proc.c b/fs/nfs/callback_proc.c index fa515d5ea5ba..7b861bbc0b43 100644 --- a/fs/nfs/callback_proc.c +++ b/fs/nfs/callback_proc.c @@ -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; diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c index f033f3a69a3b..75fe92eaa681 100644 --- a/fs/nfs/delegation.c +++ b/fs/nfs/delegation.c @@ -849,16 +849,23 @@ 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);