From 896567ee7f17a8a736cda8a28cc987228410a2ac 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 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 Otherwise, we can end up with iput() calling superblock operations that are no longer valid or accessible.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 --- 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 6bdee7ab3a6c27..62d3189745cdc7 100644 --- a/fs/nfs/internal.h +++ b/fs/nfs/internal.h @@ -599,12 +599,14 @@ 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)