diff options
| author | Stanislav Kinsbursky <skinsbursky@parallels.com> | 2011-12-26 16:39:39 +0400 |
|---|---|---|
| committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2012-02-01 03:20:24 +0400 |
| commit | c21a588f35b1c50304e505fad542b3aab0814266 (patch) | |
| tree | 2dda83e8d5f62eb9892c425941265aeeb278e952 /net | |
| parent | 90c4e82999c517e0cd00d0782c68d186cb18b784 (diff) | |
| download | linux-c21a588f35b1c50304e505fad542b3aab0814266.tar.xz | |
SUNRPC: pipefs per-net operations helper introduced
During per-net pipes creation and destruction we have to make sure, that pipefs
sb exists for the whole creation/destruction cycle. This is done by using
special mutex which controls pipefs sb reference on network namespace context.
Helper consists of two parts: first of them (rpc_get_dentry_net) searches for
dentry with specified name and returns with mutex taken on success. When pipe
creation or destructions is completed, caller should release this mutex by
rpc_put_dentry_net call.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'net')
| -rw-r--r-- | net/sunrpc/netns.h | 1 | ||||
| -rw-r--r-- | net/sunrpc/rpc_pipe.c | 36 | ||||
| -rw-r--r-- | net/sunrpc/sunrpc_syms.c | 1 |
3 files changed, 38 insertions, 0 deletions
diff --git a/net/sunrpc/netns.h b/net/sunrpc/netns.h index b3842529aec9..11d2f4863403 100644 --- a/net/sunrpc/netns.h +++ b/net/sunrpc/netns.h @@ -11,6 +11,7 @@ struct sunrpc_net { struct cache_detail *ip_map_cache; struct super_block *pipefs_sb; + struct mutex pipefs_sb_lock; }; extern int sunrpc_net_id; diff --git a/net/sunrpc/rpc_pipe.c b/net/sunrpc/rpc_pipe.c index e5e1f357b561..f075f8817773 100644 --- a/net/sunrpc/rpc_pipe.c +++ b/net/sunrpc/rpc_pipe.c @@ -1023,6 +1023,40 @@ struct dentry *rpc_d_lookup_sb(const struct super_block *sb, } EXPORT_SYMBOL_GPL(rpc_d_lookup_sb); +void rpc_pipefs_init_net(struct net *net) +{ + struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); + + mutex_init(&sn->pipefs_sb_lock); +} + +/* + * This call will be used for per network namespace operations calls. + * Note: Function will be returned with pipefs_sb_lock taken if superblock was + * found. This lock have to be released by rpc_put_sb_net() when all operations + * will be completed. + */ +struct super_block *rpc_get_sb_net(const struct net *net) +{ + struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); + + mutex_lock(&sn->pipefs_sb_lock); + if (sn->pipefs_sb) + return sn->pipefs_sb; + mutex_unlock(&sn->pipefs_sb_lock); + return NULL; +} +EXPORT_SYMBOL_GPL(rpc_get_sb_net); + +void rpc_put_sb_net(const struct net *net) +{ + struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); + + BUG_ON(sn->pipefs_sb == NULL); + mutex_unlock(&sn->pipefs_sb_lock); +} +EXPORT_SYMBOL_GPL(rpc_put_sb_net); + static int rpc_fill_super(struct super_block *sb, void *data, int silent) { @@ -1077,7 +1111,9 @@ void rpc_kill_sb(struct super_block *sb) struct net *net = sb->s_fs_info; struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); + mutex_lock(&sn->pipefs_sb_lock); sn->pipefs_sb = NULL; + mutex_unlock(&sn->pipefs_sb_lock); put_net(net); blocking_notifier_call_chain(&rpc_pipefs_notifier_list, RPC_PIPEFS_UMOUNT, diff --git a/net/sunrpc/sunrpc_syms.c b/net/sunrpc/sunrpc_syms.c index 8ec9778c3f4a..7086d11589c8 100644 --- a/net/sunrpc/sunrpc_syms.c +++ b/net/sunrpc/sunrpc_syms.c @@ -38,6 +38,7 @@ static __net_init int sunrpc_init_net(struct net *net) if (err) goto err_ipmap; + rpc_pipefs_init_net(net); return 0; err_ipmap: |