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authorStanislav Kinsbursky <skinsbursky@parallels.com>2011-12-26 15:39:22 +0300
committerTrond Myklebust <Trond.Myklebust@netapp.com>2012-01-31 18:20:24 -0500
commit432eb1a5fb380477ae759041bac2bb305977e436 (patch)
treecf00739e461828c4757f74b324bab71952284649
parent2d00131acc641b2cb6f0bdefb8c7bdd8fdf7410b (diff)
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SUNRPC: pipefs dentry lookup helper introduced
In all places, where pipefs dentries are created, only directory inode is actually required to create new dentry. And all this directories has root pipefs dentry as their parent. So we actually don't need this pipefs mount point at all if some pipefs lookup method will be provided. IOW, all we really need is just superblock and simple lookup method to find root's child dentry with appropriate name. And this patch introduces this method. Note, that no locking implemented in rpc_d_lookup_sb(). So it can be used only in case of assurance, that pipefs superblock still exist. IOW, we can use this method only in pipefs mount-umount notification subscribers callbacks. Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
-rw-r--r--include/linux/sunrpc/rpc_pipe_fs.h3
-rw-r--r--net/sunrpc/rpc_pipe.c16
2 files changed, 19 insertions, 0 deletions
diff --git a/include/linux/sunrpc/rpc_pipe_fs.h b/include/linux/sunrpc/rpc_pipe_fs.h
index d39782ce6c6..2f338223014 100644
--- a/include/linux/sunrpc/rpc_pipe_fs.h
+++ b/include/linux/sunrpc/rpc_pipe_fs.h
@@ -51,6 +51,9 @@ enum {
RPC_PIPEFS_UMOUNT,
};
+extern struct dentry *rpc_d_lookup_sb(const struct super_block *sb,
+ const unsigned char *dir_name);
+
extern ssize_t rpc_pipe_generic_upcall(struct file *, struct rpc_pipe_msg *,
char __user *, size_t);
extern int rpc_queue_upcall(struct inode *, struct rpc_pipe_msg *);
diff --git a/net/sunrpc/rpc_pipe.c b/net/sunrpc/rpc_pipe.c
index 58a5062df26..6f295e6c12a 100644
--- a/net/sunrpc/rpc_pipe.c
+++ b/net/sunrpc/rpc_pipe.c
@@ -1007,6 +1007,22 @@ static const struct rpc_filelist files[] = {
},
};
+/*
+ * This call can be used only in RPC pipefs mount notification hooks.
+ */
+struct dentry *rpc_d_lookup_sb(const struct super_block *sb,
+ const unsigned char *dir_name)
+{
+ struct qstr dir = {
+ .name = dir_name,
+ .len = strlen(dir_name),
+ .hash = full_name_hash(dir_name, strlen(dir_name)),
+ };
+
+ return d_lookup(sb->s_root, &dir);
+}
+EXPORT_SYMBOL_GPL(rpc_d_lookup_sb);
+
static int
rpc_fill_super(struct super_block *sb, void *data, int silent)
{