NFS: Reduce the stack usage in NFSv4 create operations

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 1293e0a..26fbeb3 100644 (file)
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -2079,47 +2079,81 @@ static int nfs4_proc_link(struct inode *inode, struct inode *dir, struct qstr *n
        return err;
 }
 
+struct nfs4_createdata {
+       struct rpc_message msg;
+       struct nfs4_create_arg arg;
+       struct nfs4_create_res res;
+       struct nfs_fh fh;
+       struct nfs_fattr fattr;
+       struct nfs_fattr dir_fattr;
+};
+
+static struct nfs4_createdata *nfs4_alloc_createdata(struct inode *dir,
+               struct qstr *name, struct iattr *sattr, u32 ftype)
+{
+       struct nfs4_createdata *data;
+
+       data = kzalloc(sizeof(*data), GFP_KERNEL);
+       if (data != NULL) {
+               struct nfs_server *server = NFS_SERVER(dir);
+
+               data->msg.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_CREATE];
+               data->msg.rpc_argp = &data->arg;
+               data->msg.rpc_resp = &data->res;
+               data->arg.dir_fh = NFS_FH(dir);
+               data->arg.server = server;
+               data->arg.name = name;
+               data->arg.attrs = sattr;
+               data->arg.ftype = ftype;
+               data->arg.bitmask = server->attr_bitmask;
+               data->res.server = server;
+               data->res.fh = &data->fh;
+               data->res.fattr = &data->fattr;
+               data->res.dir_fattr = &data->dir_fattr;
+               nfs_fattr_init(data->res.fattr);
+               nfs_fattr_init(data->res.dir_fattr);
+       }
+       return data;
+}
+
+static int nfs4_do_create(struct inode *dir, struct dentry *dentry, struct nfs4_createdata *data)
+{
+       int status = rpc_call_sync(NFS_CLIENT(dir), &data->msg, 0);
+       if (status == 0) {
+               update_changeattr(dir, &data->res.dir_cinfo);
+               nfs_post_op_update_inode(dir, data->res.dir_fattr);
+               status = nfs_instantiate(dentry, data->res.fh, data->res.fattr);
+       }
+       return status;
+}
+
+static void nfs4_free_createdata(struct nfs4_createdata *data)
+{
+       kfree(data);
+}
+
 static int _nfs4_proc_symlink(struct inode *dir, struct dentry *dentry,
                struct page *page, unsigned int len, struct iattr *sattr)
 {
-       struct nfs_server *server = NFS_SERVER(dir);
-       struct nfs_fh fhandle;
-       struct nfs_fattr fattr, dir_fattr;
-       struct nfs4_create_arg arg = {
-               .dir_fh = NFS_FH(dir),
-               .server = server,
-               .name = &dentry->d_name,
-               .attrs = sattr,
-               .ftype = NF4LNK,
-               .bitmask = server->attr_bitmask,
-       };
-       struct nfs4_create_res res = {
-               .server = server,
-               .fh = &fhandle,
-               .fattr = &fattr,
-               .dir_fattr = &dir_fattr,
-       };
-       struct rpc_message msg = {
-               .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_SYMLINK],
-               .rpc_argp = &arg,
-               .rpc_resp = &res,
-       };
-       int                     status;
+       struct nfs4_createdata *data;
+       int status = -ENAMETOOLONG;
 
        if (len > NFS4_MAXPATHLEN)
-               return -ENAMETOOLONG;
+               goto out;
 
-       arg.u.symlink.pages = &page;
-       arg.u.symlink.len = len;
-       nfs_fattr_init(&fattr);
-       nfs_fattr_init(&dir_fattr);
+       status = -ENOMEM;
+       data = nfs4_alloc_createdata(dir, &dentry->d_name, sattr, NF4LNK);
+       if (data == NULL)
+               goto out;
+
+       data->msg.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_SYMLINK];
+       data->arg.u.symlink.pages = &page;
+       data->arg.u.symlink.len = len;
        
-       status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
-       if (!status) {
-               update_changeattr(dir, &res.dir_cinfo);
-               nfs_post_op_update_inode(dir, res.dir_fattr);
-               status = nfs_instantiate(dentry, &fhandle, &fattr);
-       }
+       status = nfs4_do_create(dir, dentry, data);
+
+       nfs4_free_createdata(data);
+out:
        return status;
 }
 
@@ -2140,39 +2174,17 @@ static int nfs4_proc_symlink(struct inode *dir, struct dentry *dentry,
 static int _nfs4_proc_mkdir(struct inode *dir, struct dentry *dentry,
                struct iattr *sattr)
 {
-       struct nfs_server *server = NFS_SERVER(dir);
-       struct nfs_fh fhandle;
-       struct nfs_fattr fattr, dir_fattr;
-       struct nfs4_create_arg arg = {
-               .dir_fh = NFS_FH(dir),
-               .server = server,
-               .name = &dentry->d_name,
-               .attrs = sattr,
-               .ftype = NF4DIR,
-               .bitmask = server->attr_bitmask,
-       };
-       struct nfs4_create_res res = {
-               .server = server,
-               .fh = &fhandle,
-               .fattr = &fattr,
-               .dir_fattr = &dir_fattr,
-       };
-       struct rpc_message msg = {
-               .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_CREATE],
-               .rpc_argp = &arg,
-               .rpc_resp = &res,
-       };
-       int                     status;
+       struct nfs4_createdata *data;
+       int status = -ENOMEM;
 
-       nfs_fattr_init(&fattr);
-       nfs_fattr_init(&dir_fattr);
-       
-       status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
-       if (!status) {
-               update_changeattr(dir, &res.dir_cinfo);
-               nfs_post_op_update_inode(dir, res.dir_fattr);
-               status = nfs_instantiate(dentry, &fhandle, &fattr);
-       }
+       data = nfs4_alloc_createdata(dir, &dentry->d_name, sattr, NF4DIR);
+       if (data == NULL)
+               goto out;
+
+       status = nfs4_do_create(dir, dentry, data);
+
+       nfs4_free_createdata(data);
+out:
        return status;
 }
 
@@ -2242,56 +2254,34 @@ static int nfs4_proc_readdir(struct dentry *dentry, struct rpc_cred *cred,
 static int _nfs4_proc_mknod(struct inode *dir, struct dentry *dentry,
                struct iattr *sattr, dev_t rdev)
 {
-       struct nfs_server *server = NFS_SERVER(dir);
-       struct nfs_fh fh;
-       struct nfs_fattr fattr, dir_fattr;
-       struct nfs4_create_arg arg = {
-               .dir_fh = NFS_FH(dir),
-               .server = server,
-               .name = &dentry->d_name,
-               .attrs = sattr,
-               .bitmask = server->attr_bitmask,
-       };
-       struct nfs4_create_res res = {
-               .server = server,
-               .fh = &fh,
-               .fattr = &fattr,
-               .dir_fattr = &dir_fattr,
-       };
-       struct rpc_message msg = {
-               .rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_CREATE],
-               .rpc_argp = &arg,
-               .rpc_resp = &res,
-       };
-       int                     status;
-       int                     mode = sattr->ia_mode;
-
-       nfs_fattr_init(&fattr);
-       nfs_fattr_init(&dir_fattr);
+       struct nfs4_createdata *data;
+       int mode = sattr->ia_mode;
+       int status = -ENOMEM;
 
        BUG_ON(!(sattr->ia_valid & ATTR_MODE));
        BUG_ON(!S_ISFIFO(mode) && !S_ISBLK(mode) && !S_ISCHR(mode) && !S_ISSOCK(mode));
+
+       data = nfs4_alloc_createdata(dir, &dentry->d_name, sattr, NF4SOCK);
+       if (data == NULL)
+               goto out;
+
        if (S_ISFIFO(mode))
-               arg.ftype = NF4FIFO;
+               data->arg.ftype = NF4FIFO;
        else if (S_ISBLK(mode)) {
-               arg.ftype = NF4BLK;
-               arg.u.device.specdata1 = MAJOR(rdev);
-               arg.u.device.specdata2 = MINOR(rdev);
+               data->arg.ftype = NF4BLK;
+               data->arg.u.device.specdata1 = MAJOR(rdev);
+               data->arg.u.device.specdata2 = MINOR(rdev);
        }
        else if (S_ISCHR(mode)) {
-               arg.ftype = NF4CHR;
-               arg.u.device.specdata1 = MAJOR(rdev);
-               arg.u.device.specdata2 = MINOR(rdev);
+               data->arg.ftype = NF4CHR;
+               data->arg.u.device.specdata1 = MAJOR(rdev);
+               data->arg.u.device.specdata2 = MINOR(rdev);
        }
-       else
-               arg.ftype = NF4SOCK;
        
-       status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
-       if (status == 0) {
-               update_changeattr(dir, &res.dir_cinfo);
-               nfs_post_op_update_inode(dir, res.dir_fattr);
-               status = nfs_instantiate(dentry, &fh, &fattr);
-       }
+       status = nfs4_do_create(dir, dentry, data);
+
+       nfs4_free_createdata(data);
+out:
        return status;
 }