NFS: Remove nfs_readpage_sync()

It makes no sense to maintain 2 parallel systems for reading in pages.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/nfs3proc.c

@@ -253,29 +253,6 @@ static int nfs3_proc_readlink(struct inode *inode, struct page *page,
 	return status;
 }
 
-static int nfs3_proc_read(struct nfs_read_data *rdata)
-{
-	int			flags = rdata->flags;
-	struct inode *		inode = rdata->inode;
-	struct nfs_fattr *	fattr = rdata->res.fattr;
-	struct rpc_message	msg = {
-		.rpc_proc	= &nfs3_procedures[NFS3PROC_READ],
-		.rpc_argp	= &rdata->args,
-		.rpc_resp	= &rdata->res,
-		.rpc_cred	= rdata->cred,
-	};
-	int			status;
-
-	dprintk("NFS call  read %d @ %Ld\n", rdata->args.count,
-			(long long) rdata->args.offset);
-	nfs_fattr_init(fattr);
-	status = rpc_call_sync(NFS_CLIENT(inode), &msg, flags);
-	if (status >= 0)
-		nfs_refresh_inode(inode, fattr);
-	dprintk("NFS reply read: %d\n", status);
-	return status;
-}
-
 /*
  * Create a regular file.
  * For now, we don't implement O_EXCL.
@@ -855,7 +832,6 @@ const struct nfs_rpc_ops nfs_v3_clientops = {
 	.lookup		= nfs3_proc_lookup,
 	.access		= nfs3_proc_access,
 	.readlink	= nfs3_proc_readlink,
-	.read		= nfs3_proc_read,
 	.create		= nfs3_proc_create,
 	.remove		= nfs3_proc_remove,
 	.unlink_setup	= nfs3_proc_unlink_setup,

fs/nfs/nfs4proc.c

@@ -1734,44 +1734,6 @@ static int nfs4_proc_readlink(struct inode *inode, struct page *page,
 	return err;
 }
 
-static int _nfs4_proc_read(struct nfs_read_data *rdata)
-{
-	int flags = rdata->flags;
-	struct inode *inode = rdata->inode;
-	struct nfs_fattr *fattr = rdata->res.fattr;
-	struct nfs_server *server = NFS_SERVER(inode);
-	struct rpc_message msg = {
-		.rpc_proc	= &nfs4_procedures[NFSPROC4_CLNT_READ],
-		.rpc_argp	= &rdata->args,
-		.rpc_resp	= &rdata->res,
-		.rpc_cred	= rdata->cred,
-	};
-	unsigned long timestamp = jiffies;
-	int status;
-
-	dprintk("NFS call  read %d @ %Ld\n", rdata->args.count,
-			(long long) rdata->args.offset);
-
-	nfs_fattr_init(fattr);
-	status = rpc_call_sync(server->client, &msg, flags);
-	if (!status)
-		renew_lease(server, timestamp);
-	dprintk("NFS reply read: %d\n", status);
-	return status;
-}
-
-static int nfs4_proc_read(struct nfs_read_data *rdata)
-{
-	struct nfs4_exception exception = { };
-	int err;
-	do {
-		err = nfs4_handle_exception(NFS_SERVER(rdata->inode),
-				_nfs4_proc_read(rdata),
-				&exception);
-	} while (exception.retry);
-	return err;
-}
-
 /*
  * Got race?
  * We will need to arrange for the VFS layer to provide an atomic open.
@@ -3643,7 +3605,6 @@ const struct nfs_rpc_ops nfs_v4_clientops = {
 	.lookup		= nfs4_proc_lookup,
 	.access		= nfs4_proc_access,
 	.readlink	= nfs4_proc_readlink,
-	.read		= nfs4_proc_read,
 	.create		= nfs4_proc_create,
 	.remove		= nfs4_proc_remove,
 	.unlink_setup	= nfs4_proc_unlink_setup,

fs/nfs/proc.c

@@ -186,35 +186,6 @@ static int nfs_proc_readlink(struct inode *inode, struct page *page,
 	return status;
 }
 
-static int nfs_proc_read(struct nfs_read_data *rdata)
-{
-	int			flags = rdata->flags;
-	struct inode *		inode = rdata->inode;
-	struct nfs_fattr *	fattr = rdata->res.fattr;
-	struct rpc_message	msg = {
-		.rpc_proc	= &nfs_procedures[NFSPROC_READ],
-		.rpc_argp	= &rdata->args,
-		.rpc_resp	= &rdata->res,
-		.rpc_cred	= rdata->cred,
-	};
-	int			status;
-
-	dprintk("NFS call  read %d @ %Ld\n", rdata->args.count,
-			(long long) rdata->args.offset);
-	nfs_fattr_init(fattr);
-	status = rpc_call_sync(NFS_CLIENT(inode), &msg, flags);
-	if (status >= 0) {
-		nfs_refresh_inode(inode, fattr);
-		/* Emulate the eof flag, which isn't normally needed in NFSv2
-		 * as it is guaranteed to always return the file attributes
-		 */
-		if (rdata->args.offset + rdata->args.count >= fattr->size)
-			rdata->res.eof = 1;
-	}
-	dprintk("NFS reply read: %d\n", status);
-	return status;
-}
-
 static int
 nfs_proc_create(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
 		int flags, struct nameidata *nd)
@@ -666,7 +637,6 @@ const struct nfs_rpc_ops nfs_v2_clientops = {
 	.lookup		= nfs_proc_lookup,
 	.access		= NULL,		       /* access */
 	.readlink	= nfs_proc_readlink,
-	.read		= nfs_proc_read,
 	.create		= nfs_proc_create,
 	.remove		= nfs_proc_remove,
 	.unlink_setup	= nfs_proc_unlink_setup,

fs/nfs/read.c

@@ -5,14 +5,6 @@
  *
  * Partial copy of Linus' read cache modifications to fs/nfs/file.c
  * modified for async RPC by okir@monad.swb.de
- *
- * We do an ugly hack here in order to return proper error codes to the
- * user program when a read request failed: since generic_file_read
- * only checks the return value of inode->i_op->readpage() which is always 0
- * for async RPC, we set the error bit of the page to 1 when an error occurs,
- * and make nfs_readpage transmit requests synchronously when encountering this.
- * This is only a small problem, though, since we now retry all operations
- * within the RPC code when root squashing is suspected.
  */
 
 #include <linux/time.h>
@@ -122,93 +114,6 @@ static void nfs_readpage_truncate_uninitialised_page(struct nfs_read_data *data)
 	}
 }
 
-/*
- * Read a page synchronously.
- */
-static int nfs_readpage_sync(struct nfs_open_context *ctx, struct inode *inode,
-		struct page *page)
-{
-	unsigned int	rsize = NFS_SERVER(inode)->rsize;
-	unsigned int	count = PAGE_CACHE_SIZE;
-	int result = -ENOMEM;
-	struct nfs_read_data *rdata;
-
-	rdata = nfs_readdata_alloc(count);
-	if (!rdata)
-		goto out_unlock;
-
-	memset(rdata, 0, sizeof(*rdata));
-	rdata->flags = (IS_SWAPFILE(inode)? NFS_RPC_SWAPFLAGS : 0);
-	rdata->cred = ctx->cred;
-	rdata->inode = inode;
-	INIT_LIST_HEAD(&rdata->pages);
-	rdata->args.fh = NFS_FH(inode);
-	rdata->args.context = ctx;
-	rdata->args.pages = &page;
-	rdata->args.pgbase = 0UL;
-	rdata->args.count = rsize;
-	rdata->res.fattr = &rdata->fattr;
-
-	dprintk("NFS: nfs_readpage_sync(%p)\n", page);
-
-	/*
-	 * This works now because the socket layer never tries to DMA
-	 * into this buffer directly.
-	 */
-	do {
-		if (count < rsize)
-			rdata->args.count = count;
-		rdata->res.count = rdata->args.count;
-		rdata->args.offset = page_offset(page) + rdata->args.pgbase;
-
-		dprintk("NFS: nfs_proc_read(%s, (%s/%Ld), %Lu, %u)\n",
-			NFS_SERVER(inode)->nfs_client->cl_hostname,
-			inode->i_sb->s_id,
-			(long long)NFS_FILEID(inode),
-			(unsigned long long)rdata->args.pgbase,
-			rdata->args.count);
-
-		lock_kernel();
-		result = NFS_PROTO(inode)->read(rdata);
-		unlock_kernel();
-
-		/*
-		 * Even if we had a partial success we can't mark the page
-		 * cache valid.
-		 */
-		if (result < 0) {
-			if (result == -EISDIR)
-				result = -EINVAL;
-			goto io_error;
-		}
-		count -= result;
-		rdata->args.pgbase += result;
-		nfs_add_stats(inode, NFSIOS_SERVERREADBYTES, result);
-
-		/* Note: result == 0 should only happen if we're caching
-		 * a write that extends the file and punches a hole.
-		 */
-		if (rdata->res.eof != 0 || result == 0)
-			break;
-	} while (count);
-	spin_lock(&inode->i_lock);
-	NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ATIME;
-	spin_unlock(&inode->i_lock);
-
-	if (rdata->res.eof || rdata->res.count == rdata->args.count) {
-		SetPageUptodate(page);
-		if (rdata->res.eof && count != 0)
-			memclear_highpage_flush(page, rdata->args.pgbase, count);
-	}
-	result = 0;
-
-io_error:
-	nfs_readdata_free(rdata);
-out_unlock:
-	unlock_page(page);
-	return result;
-}
-
 static int nfs_readpage_async(struct nfs_open_context *ctx, struct inode *inode,
 		struct page *page)
 {
@@ -621,15 +526,9 @@ int nfs_readpage(struct file *file, struct page *page)
 	} else
 		ctx = get_nfs_open_context((struct nfs_open_context *)
 				file->private_data);
-	if (!IS_SYNC(inode)) {
-		error = nfs_readpage_async(ctx, inode, page);
-		goto out;
-	}
 
-	error = nfs_readpage_sync(ctx, inode, page);
-	if (error < 0 && IS_SWAPFILE(inode))
-		printk("Aiee.. nfs swap-in of page failed!\n");
-out:
+	error = nfs_readpage_async(ctx, inode, page);
+
 	put_nfs_open_context(ctx);
 	return error;
 

include/linux/nfs_xdr.h

@@ -784,7 +784,6 @@ struct nfs_rpc_ops {
 	int	(*access)  (struct inode *, struct nfs_access_entry *);
 	int	(*readlink)(struct inode *, struct page *, unsigned int,
 			    unsigned int);
-	int	(*read)    (struct nfs_read_data *);
 	int	(*create)  (struct inode *, struct dentry *,
 			    struct iattr *, int, struct nameidata *);
 	int	(*remove)  (struct inode *, struct qstr *);