static struct rpc_clnt *nfs_lookup_mountpoint(struct inode *dir, struct qstr *name, struct nfs_fh *fh, struct nfs_fattr *fattr) { int err; if (NFS_PROTO(dir)->version == 4) return nfs4_proc_lookup_mountpoint(dir, name, fh, fattr); err = NFS_PROTO(dir)->lookup(NFS_SERVER(dir)->client, dir, name, fh, fattr); if (err) return ERR_PTR(err); return rpc_clone_client(NFS_SERVER(dir)->client); }
/** * nfs_follow_referral - set up mountpoint when hitting a referral on moved error * @dentry - parent directory * @locations - array of NFSv4 server location information * */ static struct vfsmount *nfs_follow_referral(struct dentry *dentry, const struct nfs4_fs_locations *locations) { struct vfsmount *mnt = ERR_PTR(-ENOENT); struct nfs_clone_mount mountdata = { .sb = dentry->d_sb, .dentry = dentry, .authflavor = NFS_SB(dentry->d_sb)->client->cl_auth->au_flavor, }; char *page = NULL, *page2 = NULL; int loc, error; if (locations == NULL || locations->nlocations <= 0) goto out; dprintk("%s: referral at %s/%s\n", __func__, dentry->d_parent->d_name.name, dentry->d_name.name); page = (char *) __get_free_page(GFP_USER); if (!page) goto out; page2 = (char *) __get_free_page(GFP_USER); if (!page2) goto out; /* Ensure fs path is a prefix of current dentry path */ error = nfs4_validate_fspath(dentry, locations, page, page2); if (error < 0) { mnt = ERR_PTR(error); goto out; } for (loc = 0; loc < locations->nlocations; loc++) { const struct nfs4_fs_location *location = &locations->locations[loc]; if (location == NULL || location->nservers <= 0 || location->rootpath.ncomponents == 0) continue; mnt = try_location(&mountdata, page, page2, location); if (!IS_ERR(mnt)) break; } out: free_page((unsigned long) page); free_page((unsigned long) page2); dprintk("%s: done\n", __func__); return mnt; } /* * nfs_do_refmount - handle crossing a referral on server * @dentry - dentry of referral * */ static struct vfsmount *nfs_do_refmount(struct rpc_clnt *client, struct dentry *dentry) { struct vfsmount *mnt = ERR_PTR(-ENOMEM); struct dentry *parent; struct nfs4_fs_locations *fs_locations = NULL; struct page *page; int err; /* BUG_ON(IS_ROOT(dentry)); */ dprintk("%s: enter\n", __func__); page = alloc_page(GFP_KERNEL); if (page == NULL) goto out; fs_locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL); if (fs_locations == NULL) goto out_free; /* Get locations */ mnt = ERR_PTR(-ENOENT); parent = dget_parent(dentry); dprintk("%s: getting locations for %s/%s\n", __func__, parent->d_name.name, dentry->d_name.name); err = nfs4_proc_fs_locations(client, parent->d_inode, &dentry->d_name, fs_locations, page); dput(parent); if (err != 0 || fs_locations->nlocations <= 0 || fs_locations->fs_path.ncomponents <= 0) goto out_free; mnt = nfs_follow_referral(dentry, fs_locations); out_free: __free_page(page); kfree(fs_locations); out: dprintk("%s: done\n", __func__); return mnt; } struct vfsmount *nfs4_submount(struct nfs_server *server, struct dentry *dentry, struct nfs_fh *fh, struct nfs_fattr *fattr) { struct dentry *parent = dget_parent(dentry); struct rpc_clnt *client; struct vfsmount *mnt; /* Look it up again to get its attributes and sec flavor */ client = nfs4_proc_lookup_mountpoint(parent->d_inode, &dentry->d_name, fh, fattr); dput(parent); if (IS_ERR(client)) return ERR_CAST(client); if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) mnt = nfs_do_refmount(client, dentry); else mnt = nfs_do_submount(dentry, fh, fattr, client->cl_auth->au_flavor); rpc_shutdown_client(client); return mnt; }