From 38992092b54e3f3847a102087c946fea8f15280c Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Sun, 10 Jan 2021 15:58:08 -0500 Subject: [PATCH] NFS: nfs_igrab_and_active must first reference the superblock commit 896567ee7f17a8a736cda8a28cc987228410a2ac upstream. Before referencing the inode, we must ensure that the superblock can be referenced. Otherwise, we can end up with iput() calling superblock operations that are no longer valid or accessible. Fixes: ea7c38fef0b7 ("NFSv4: Ensure we reference the inode for return-on-close in delegreturn") Signed-off-by: Trond Myklebust Signed-off-by: Greg Kroah-Hartman --- fs/nfs/internal.h | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h index 447a3c17fa8e..9e717796e57b 100644 --- a/fs/nfs/internal.h +++ b/fs/nfs/internal.h @@ -569,12 +569,14 @@ extern void nfs4_test_session_trunk(struct rpc_clnt *clnt, static inline struct inode *nfs_igrab_and_active(struct inode *inode) { - inode = igrab(inode); - if (inode != NULL && !nfs_sb_active(inode->i_sb)) { - iput(inode); - inode = NULL; + struct super_block *sb = inode->i_sb; + + if (sb && nfs_sb_active(sb)) { + if (igrab(inode)) + return inode; + nfs_sb_deactive(sb); } - return inode; + return NULL; } static inline void nfs_iput_and_deactive(struct inode *inode)