From 1dcddd4abd2c6df7f28928ad5cafa4a1cd20030b Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 3 Oct 2013 13:22:44 -0400 Subject: [PATCH] ncpfs: rcu-delay unload_nls() and freeing ncp_server makes ->d_hash() and ->d_compare() safety in RCU mode independent from vfsmount_lock. Signed-off-by: Al Viro --- fs/ncpfs/inode.c | 19 ++++++++++++------- fs/ncpfs/ncp_fs_sb.h | 2 +- 2 files changed, 13 insertions(+), 8 deletions(-) diff --git a/fs/ncpfs/inode.c b/fs/ncpfs/inode.c index 4659da67e7f6..2cf2ebecb55f 100644 --- a/fs/ncpfs/inode.c +++ b/fs/ncpfs/inode.c @@ -782,6 +782,17 @@ out: return error; } +static void delayed_free(struct rcu_head *p) +{ + struct ncp_server *server = container_of(p, struct ncp_server, rcu); +#ifdef CONFIG_NCPFS_NLS + /* unload the NLS charsets */ + unload_nls(server->nls_vol); + unload_nls(server->nls_io); +#endif /* CONFIG_NCPFS_NLS */ + kfree(server); +} + static void ncp_put_super(struct super_block *sb) { struct ncp_server *server = NCP_SBP(sb); @@ -792,11 +803,6 @@ static void ncp_put_super(struct super_block *sb) ncp_stop_tasks(server); -#ifdef CONFIG_NCPFS_NLS - /* unload the NLS charsets */ - unload_nls(server->nls_vol); - unload_nls(server->nls_io); -#endif /* CONFIG_NCPFS_NLS */ mutex_destroy(&server->rcv.creq_mutex); mutex_destroy(&server->root_setup_lock); mutex_destroy(&server->mutex); @@ -813,8 +819,7 @@ static void ncp_put_super(struct super_block *sb) vfree(server->rxbuf); vfree(server->txbuf); vfree(server->packet); - sb->s_fs_info = NULL; - kfree(server); + call_rcu(&server->rcu, delayed_free); } static int ncp_statfs(struct dentry *dentry, struct kstatfs *buf) diff --git a/fs/ncpfs/ncp_fs_sb.h b/fs/ncpfs/ncp_fs_sb.h index c51b2c543539..b81e97adc5a9 100644 --- a/fs/ncpfs/ncp_fs_sb.h +++ b/fs/ncpfs/ncp_fs_sb.h @@ -38,7 +38,7 @@ struct ncp_mount_data_kernel { }; struct ncp_server { - + struct rcu_head rcu; struct ncp_mount_data_kernel m; /* Nearly all of the mount data is of interest for us later, so we store it completely. */ -- 2.20.1