NFS: Reduce the stack usage in NFSv4 create operations

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

1 files changed, 97 insertions, 107 deletions

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 1293e0acd82b..26fbeb3467cb 100644
--- 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;
 }