NFS: Reduce the stack usage in NFSv3 create operations
authorTrond Myklebust <Trond.Myklebust@netapp.com>
Fri, 20 Jun 2008 21:00:23 +0000 (17:00 -0400)
committerTrond Myklebust <Trond.Myklebust@netapp.com>
Wed, 9 Jul 2008 16:08:38 +0000 (12:08 -0400)
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
fs/nfs/nfs3proc.c

index c3523ad03ed1b6d860b4782878eeb01ccfd071c3..cf7d4e5927d6be2d5e49f7995cd88cce8e0430b2 100644 (file)
@@ -248,6 +248,53 @@ static int nfs3_proc_readlink(struct inode *inode, struct page *page,
        return status;
 }
 
+struct nfs3_createdata {
+       struct rpc_message msg;
+       union {
+               struct nfs3_createargs create;
+               struct nfs3_mkdirargs mkdir;
+               struct nfs3_symlinkargs symlink;
+               struct nfs3_mknodargs mknod;
+       } arg;
+       struct nfs3_diropres res;
+       struct nfs_fh fh;
+       struct nfs_fattr fattr;
+       struct nfs_fattr dir_attr;
+};
+
+static struct nfs3_createdata *nfs3_alloc_createdata(void)
+{
+       struct nfs3_createdata *data;
+
+       data = kzalloc(sizeof(*data), GFP_KERNEL);
+       if (data != NULL) {
+               data->msg.rpc_argp = &data->arg;
+               data->msg.rpc_resp = &data->res;
+               data->res.fh = &data->fh;
+               data->res.fattr = &data->fattr;
+               data->res.dir_attr = &data->dir_attr;
+               nfs_fattr_init(data->res.fattr);
+               nfs_fattr_init(data->res.dir_attr);
+       }
+       return data;
+}
+
+static int nfs3_do_create(struct inode *dir, struct dentry *dentry, struct nfs3_createdata *data)
+{
+       int status;
+
+       status = rpc_call_sync(NFS_CLIENT(dir), &data->msg, 0);
+       nfs_post_op_update_inode(dir, data->res.dir_attr);
+       if (status == 0)
+               status = nfs_instantiate(dentry, data->res.fh, data->res.fattr);
+       return status;
+}
+
+static void nfs3_free_createdata(struct nfs3_createdata *data)
+{
+       kfree(data);
+}
+
 /*
  * Create a regular file.
  * For now, we don't implement O_EXCL.
@@ -256,70 +303,60 @@ static int
 nfs3_proc_create(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
                 int flags, struct nameidata *nd)
 {
-       struct nfs_fh           fhandle;
-       struct nfs_fattr        fattr;
-       struct nfs_fattr        dir_attr;
-       struct nfs3_createargs  arg = {
-               .fh             = NFS_FH(dir),
-               .name           = dentry->d_name.name,
-               .len            = dentry->d_name.len,
-               .sattr          = sattr,
-       };
-       struct nfs3_diropres    res = {
-               .dir_attr       = &dir_attr,
-               .fh             = &fhandle,
-               .fattr          = &fattr
-       };
-       struct rpc_message msg = {
-               .rpc_proc       = &nfs3_procedures[NFS3PROC_CREATE],
-               .rpc_argp       = &arg,
-               .rpc_resp       = &res,
-       };
+       struct nfs3_createdata *data;
        mode_t mode = sattr->ia_mode;
-       int status;
+       int status = -ENOMEM;
 
        dprintk("NFS call  create %s\n", dentry->d_name.name);
-       arg.createmode = NFS3_CREATE_UNCHECKED;
+
+       data = nfs3_alloc_createdata();
+       if (data == NULL)
+               goto out;
+
+       data->msg.rpc_proc = &nfs3_procedures[NFS3PROC_CREATE];
+       data->arg.create.fh = NFS_FH(dir);
+       data->arg.create.name = dentry->d_name.name;
+       data->arg.create.len = dentry->d_name.len;
+       data->arg.create.sattr = sattr;
+
+       data->arg.create.createmode = NFS3_CREATE_UNCHECKED;
        if (flags & O_EXCL) {
-               arg.createmode  = NFS3_CREATE_EXCLUSIVE;
-               arg.verifier[0] = jiffies;
-               arg.verifier[1] = current->pid;
+               data->arg.create.createmode  = NFS3_CREATE_EXCLUSIVE;
+               data->arg.create.verifier[0] = jiffies;
+               data->arg.create.verifier[1] = current->pid;
        }
 
        sattr->ia_mode &= ~current->fs->umask;
 
-again:
-       nfs_fattr_init(&dir_attr);
-       nfs_fattr_init(&fattr);
-       status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
-       nfs_refresh_inode(dir, &dir_attr);
+       for (;;) {
+               status = nfs3_do_create(dir, dentry, data);
 
-       /* If the server doesn't support the exclusive creation semantics,
-        * try again with simple 'guarded' mode. */
-       if (status == -ENOTSUPP) {
-               switch (arg.createmode) {
+               if (status != -ENOTSUPP)
+                       break;
+               /* If the server doesn't support the exclusive creation
+                * semantics, try again with simple 'guarded' mode. */
+               switch (data->arg.create.createmode) {
                        case NFS3_CREATE_EXCLUSIVE:
-                               arg.createmode = NFS3_CREATE_GUARDED;
+                               data->arg.create.createmode = NFS3_CREATE_GUARDED;
                                break;
 
                        case NFS3_CREATE_GUARDED:
-                               arg.createmode = NFS3_CREATE_UNCHECKED;
+                               data->arg.create.createmode = NFS3_CREATE_UNCHECKED;
                                break;
 
                        case NFS3_CREATE_UNCHECKED:
                                goto out;
                }
-               goto again;
+               nfs_fattr_init(data->res.dir_attr);
+               nfs_fattr_init(data->res.fattr);
        }
 
-       if (status == 0)
-               status = nfs_instantiate(dentry, &fhandle, &fattr);
        if (status != 0)
                goto out;
 
        /* When we created the file with exclusive semantics, make
         * sure we set the attributes afterwards. */
-       if (arg.createmode == NFS3_CREATE_EXCLUSIVE) {
+       if (data->arg.create.createmode == NFS3_CREATE_EXCLUSIVE) {
                dprintk("NFS call  setattr (post-create)\n");
 
                if (!(sattr->ia_valid & ATTR_ATIME_SET))
@@ -330,14 +367,15 @@ again:
                /* Note: we could use a guarded setattr here, but I'm
                 * not sure this buys us anything (and I'd have
                 * to revamp the NFSv3 XDR code) */
-               status = nfs3_proc_setattr(dentry, &fattr, sattr);
-               nfs_post_op_update_inode(dentry->d_inode, &fattr);
+               status = nfs3_proc_setattr(dentry, data->res.fattr, sattr);
+               nfs_post_op_update_inode(dentry->d_inode, data->res.fattr);
                dprintk("NFS reply setattr (post-create): %d\n", status);
+               if (status != 0)
+                       goto out;
        }
-       if (status != 0)
-               goto out;
        status = nfs3_proc_set_default_acl(dir, dentry->d_inode, mode);
 out:
+       nfs3_free_createdata(data);
        dprintk("NFS reply create: %d\n", status);
        return status;
 }
@@ -452,40 +490,28 @@ static int
 nfs3_proc_symlink(struct inode *dir, struct dentry *dentry, struct page *page,
                  unsigned int len, struct iattr *sattr)
 {
-       struct nfs_fh fhandle;
-       struct nfs_fattr fattr, dir_attr;
-       struct nfs3_symlinkargs arg = {
-               .fromfh         = NFS_FH(dir),
-               .fromname       = dentry->d_name.name,
-               .fromlen        = dentry->d_name.len,
-               .pages          = &page,
-               .pathlen        = len,
-               .sattr          = sattr
-       };
-       struct nfs3_diropres    res = {
-               .dir_attr       = &dir_attr,
-               .fh             = &fhandle,
-               .fattr          = &fattr
-       };
-       struct rpc_message msg = {
-               .rpc_proc       = &nfs3_procedures[NFS3PROC_SYMLINK],
-               .rpc_argp       = &arg,
-               .rpc_resp       = &res,
-       };
-       int                     status;
+       struct nfs3_createdata *data;
+       int status = -ENOMEM;
 
        if (len > NFS3_MAXPATHLEN)
                return -ENAMETOOLONG;
 
        dprintk("NFS call  symlink %s\n", dentry->d_name.name);
 
-       nfs_fattr_init(&dir_attr);
-       nfs_fattr_init(&fattr);
-       status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
-       nfs_post_op_update_inode(dir, &dir_attr);
-       if (status != 0)
+       data = nfs3_alloc_createdata();
+       if (data == NULL)
                goto out;
-       status = nfs_instantiate(dentry, &fhandle, &fattr);
+       data->msg.rpc_proc = &nfs3_procedures[NFS3PROC_SYMLINK];
+       data->arg.symlink.fromfh = NFS_FH(dir);
+       data->arg.symlink.fromname = dentry->d_name.name;
+       data->arg.symlink.fromlen = dentry->d_name.len;
+       data->arg.symlink.pages = &page;
+       data->arg.symlink.pathlen = len;
+       data->arg.symlink.sattr = sattr;
+
+       status = nfs3_do_create(dir, dentry, data);
+
+       nfs3_free_createdata(data);
 out:
        dprintk("NFS reply symlink: %d\n", status);
        return status;
@@ -494,42 +520,31 @@ out:
 static int
 nfs3_proc_mkdir(struct inode *dir, struct dentry *dentry, struct iattr *sattr)
 {
-       struct nfs_fh fhandle;
-       struct nfs_fattr fattr, dir_attr;
-       struct nfs3_mkdirargs   arg = {
-               .fh             = NFS_FH(dir),
-               .name           = dentry->d_name.name,
-               .len            = dentry->d_name.len,
-               .sattr          = sattr
-       };
-       struct nfs3_diropres    res = {
-               .dir_attr       = &dir_attr,
-               .fh             = &fhandle,
-               .fattr          = &fattr
-       };
-       struct rpc_message msg = {
-               .rpc_proc       = &nfs3_procedures[NFS3PROC_MKDIR],
-               .rpc_argp       = &arg,
-               .rpc_resp       = &res,
-       };
+       struct nfs3_createdata *data;
        int mode = sattr->ia_mode;
-       int status;
+       int status = -ENOMEM;
 
        dprintk("NFS call  mkdir %s\n", dentry->d_name.name);
 
        sattr->ia_mode &= ~current->fs->umask;
 
-       nfs_fattr_init(&dir_attr);
-       nfs_fattr_init(&fattr);
-       status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
-       nfs_post_op_update_inode(dir, &dir_attr);
-       if (status != 0)
+       data = nfs3_alloc_createdata();
+       if (data == NULL)
                goto out;
-       status = nfs_instantiate(dentry, &fhandle, &fattr);
+
+       data->msg.rpc_proc = &nfs3_procedures[NFS3PROC_MKDIR];
+       data->arg.mkdir.fh = NFS_FH(dir);
+       data->arg.mkdir.name = dentry->d_name.name;
+       data->arg.mkdir.len = dentry->d_name.len;
+       data->arg.mkdir.sattr = sattr;
+
+       status = nfs3_do_create(dir, dentry, data);
        if (status != 0)
                goto out;
+
        status = nfs3_proc_set_default_acl(dir, dentry->d_inode, mode);
 out:
+       nfs3_free_createdata(data);
        dprintk("NFS reply mkdir: %d\n", status);
        return status;
 }
@@ -615,52 +630,50 @@ static int
 nfs3_proc_mknod(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
                dev_t rdev)
 {
-       struct nfs_fh fh;
-       struct nfs_fattr fattr, dir_attr;
-       struct nfs3_mknodargs   arg = {
-               .fh             = NFS_FH(dir),
-               .name           = dentry->d_name.name,
-               .len            = dentry->d_name.len,
-               .sattr          = sattr,
-               .rdev           = rdev
-       };
-       struct nfs3_diropres    res = {
-               .dir_attr       = &dir_attr,
-               .fh             = &fh,
-               .fattr          = &fattr
-       };
-       struct rpc_message msg = {
-               .rpc_proc       = &nfs3_procedures[NFS3PROC_MKNOD],
-               .rpc_argp       = &arg,
-               .rpc_resp       = &res,
-       };
+       struct nfs3_createdata *data;
        mode_t mode = sattr->ia_mode;
-       int status;
-
-       switch (sattr->ia_mode & S_IFMT) {
-       case S_IFBLK:   arg.type = NF3BLK;  break;
-       case S_IFCHR:   arg.type = NF3CHR;  break;
-       case S_IFIFO:   arg.type = NF3FIFO; break;
-       case S_IFSOCK:  arg.type = NF3SOCK; break;
-       default:        return -EINVAL;
-       }
+       int status = -ENOMEM;
 
        dprintk("NFS call  mknod %s %u:%u\n", dentry->d_name.name,
                        MAJOR(rdev), MINOR(rdev));
 
        sattr->ia_mode &= ~current->fs->umask;
 
-       nfs_fattr_init(&dir_attr);
-       nfs_fattr_init(&fattr);
-       status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
-       nfs_post_op_update_inode(dir, &dir_attr);
-       if (status != 0)
+       data = nfs3_alloc_createdata();
+       if (data == NULL)
                goto out;
-       status = nfs_instantiate(dentry, &fh, &fattr);
+
+       data->msg.rpc_proc = &nfs3_procedures[NFS3PROC_MKNOD];
+       data->arg.mknod.fh = NFS_FH(dir);
+       data->arg.mknod.name = dentry->d_name.name;
+       data->arg.mknod.len = dentry->d_name.len;
+       data->arg.mknod.sattr = sattr;
+       data->arg.mknod.rdev = rdev;
+
+       switch (sattr->ia_mode & S_IFMT) {
+       case S_IFBLK:
+               data->arg.mknod.type = NF3BLK;
+               break;
+       case S_IFCHR:
+               data->arg.mknod.type = NF3CHR;
+               break;
+       case S_IFIFO:
+               data->arg.mknod.type = NF3FIFO;
+               break;
+       case S_IFSOCK:
+               data->arg.mknod.type = NF3SOCK;
+               break;
+       default:
+               status = -EINVAL;
+               goto out;
+       }
+
+       status = nfs3_do_create(dir, dentry, data);
        if (status != 0)
                goto out;
        status = nfs3_proc_set_default_acl(dir, dentry->d_inode, mode);
 out:
+       nfs3_free_createdata(data);
        dprintk("NFS reply mknod: %d\n", status);
        return status;
 }