[PATCH v3 2/4] NFS: release per-net clients lock before calling PipeFS dentries creation
From: Stanislav Kinsbursky <hidden>
Date: 2012-02-27 18:05:56
Also in:
linux-nfs, lkml
Subsystem:
filesystems (vfs and infrastructure), nfs, sunrpc, and lockd clients, the rest · Maintainers:
Alexander Viro, Christian Brauner, Trond Myklebust, Anna Schumaker, Linus Torvalds
v3: 1) Lookup for client is performed from the beginning of the list on each PipeFS event handling operation. Lockdep is sad otherwise, because inode mutex is taken on PipeFS dentry creation, which can be called on mount notification, where this per-net client lock is taken on clients list walk. Signed-off-by: Stanislav Kinsbursky <redacted> --- fs/nfs/idmap.c | 30 ++++++++++++++++++++++++------ 1 files changed, 24 insertions(+), 6 deletions(-)
diff --git a/fs/nfs/idmap.c b/fs/nfs/idmap.c
index b5c6d8e..d4db3b6 100644
--- a/fs/nfs/idmap.c
+++ b/fs/nfs/idmap.c@@ -553,23 +553,41 @@ static int __rpc_pipefs_event(struct nfs_client *clp, unsigned long event, return err; } -static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event, - void *ptr) +static struct nfs_client *nfs_get_client_for_event(struct net *net, int event) { - struct super_block *sb = ptr; - struct nfs_net *nn = net_generic(sb->s_fs_info, nfs_net_id); + struct nfs_net *nn = net_generic(net, nfs_net_id); + struct dentry *cl_dentry; struct nfs_client *clp; - int error = 0; spin_lock(&nn->nfs_client_lock); list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) { if (clp->rpc_ops != &nfs_v4_clientops) continue; + cl_dentry = clp->cl_idmap->idmap_pipe->dentry; + if (((event == RPC_PIPEFS_MOUNT) && cl_dentry) || + ((event == RPC_PIPEFS_UMOUNT) && !cl_dentry)) + continue; + atomic_inc(&clp->cl_count); + spin_unlock(&nn->nfs_client_lock); + return clp; + } + spin_unlock(&nn->nfs_client_lock); + return NULL; +} + +static int rpc_pipefs_event(struct notifier_block *nb, unsigned long event, + void *ptr) +{ + struct super_block *sb = ptr; + struct nfs_client *clp; + int error = 0; + + while ((clp = nfs_get_client_for_event(sb->s_fs_info, event))) { error = __rpc_pipefs_event(clp, event, sb); + nfs_put_client(clp); if (error) break; } - spin_unlock(&nn->nfs_client_lock); return error; } --
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html