NFSv4.1: Fall back to ordinary i/o through the mds if we have no layout segment

[pandora-kernel.git] / fs / nfs / read.c

diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index 2bcf0dc..9b2a1d7 100644 (file)
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -32,6 +32,7 @@
 
 static int nfs_pagein_multi(struct nfs_pageio_descriptor *desc);
 static int nfs_pagein_one(struct nfs_pageio_descriptor *desc);
+static const struct nfs_pageio_ops nfs_pageio_read_ops;
 static const struct rpc_call_ops nfs_read_partial_ops;
 static const struct rpc_call_ops nfs_read_full_ops;
 
@@ -113,6 +114,20 @@ static void nfs_readpage_truncate_uninitialised_page(struct nfs_read_data *data)
        }
 }
 
+void nfs_pageio_init_read_mds(struct nfs_pageio_descriptor *pgio,
+               struct inode *inode)
+{
+       nfs_pageio_init(pgio, inode, &nfs_pageio_read_ops,
+                       NFS_SERVER(inode)->rsize, 0);
+}
+
+static void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
+               struct inode *inode)
+{
+       if (!pnfs_pageio_init_read(pgio, inode))
+               nfs_pageio_init_read_mds(pgio, inode);
+}
+
 int nfs_readpage_async(struct nfs_open_context *ctx, struct inode *inode,
                       struct page *page)
 {
@@ -131,14 +146,9 @@ int nfs_readpage_async(struct nfs_open_context *ctx, struct inode *inode,
        if (len < PAGE_CACHE_SIZE)
                zero_user_segment(page, len, PAGE_CACHE_SIZE);
 
-       nfs_pageio_init(&pgio, inode, NULL, 0, 0);
-       nfs_list_add_request(new, &pgio.pg_list);
-       pgio.pg_count = len;
-
-       if (NFS_SERVER(inode)->rsize < PAGE_CACHE_SIZE)
-               nfs_pagein_multi(&pgio);
-       else
-               nfs_pagein_one(&pgio);
+       nfs_pageio_init_read(&pgio, inode);
+       nfs_pageio_add_request(&pgio, new);
+       nfs_pageio_complete(&pgio);
        return 0;
 }
 
@@ -269,7 +279,7 @@ static int nfs_pagein_multi(struct nfs_pageio_descriptor *desc)
        unsigned int offset;
        int requests = 0;
        int ret = 0;
-       struct pnfs_layout_segment *lseg;
+       struct pnfs_layout_segment *lseg = desc->pg_lseg;
        LIST_HEAD(list);
 
        nfs_list_remove_request(req);
@@ -287,8 +297,6 @@ static int nfs_pagein_multi(struct nfs_pageio_descriptor *desc)
        } while(nbytes != 0);
        atomic_set(&req->wb_complete, requests);
 
-       BUG_ON(desc->pg_lseg != NULL);
-       lseg = pnfs_update_layout(desc->pg_inode, req->wb_context, IOMODE_READ, GFP_KERNEL);
        ClearPageError(page);
        offset = 0;
        nbytes = desc->pg_count;
@@ -322,6 +330,8 @@ out_bad:
        }
        SetPageError(page);
        nfs_readpage_release(req);
+       put_lseg(lseg);
+       desc->pg_lseg = NULL;
        return -ENOMEM;
 }
 
@@ -350,8 +360,6 @@ static int nfs_pagein_one(struct nfs_pageio_descriptor *desc)
                *pages++ = req->wb_page;
        }
        req = nfs_list_entry(data->pages.next);
-       if ((!lseg) && list_is_singular(&data->pages))
-               lseg = pnfs_update_layout(desc->pg_inode, req->wb_context, IOMODE_READ, GFP_KERNEL);
 
        ret = nfs_read_rpcsetup(req, data, &nfs_read_full_ops, desc->pg_count,
                                0, lseg);
@@ -361,6 +369,20 @@ out:
        return ret;
 }
 
+int nfs_generic_pg_readpages(struct nfs_pageio_descriptor *desc)
+{
+       if (desc->pg_bsize < PAGE_CACHE_SIZE)
+               return nfs_pagein_multi(desc);
+       return nfs_pagein_one(desc);
+}
+EXPORT_SYMBOL_GPL(nfs_generic_pg_readpages);
+
+
+static const struct nfs_pageio_ops nfs_pageio_read_ops = {
+       .pg_test = nfs_generic_pg_test,
+       .pg_doio = nfs_generic_pg_readpages,
+};
+
 /*
  * This is the callback from RPC telling us whether a reply was
  * received or some error occurred (timeout or socket shutdown).
@@ -631,8 +653,6 @@ int nfs_readpages(struct file *filp, struct address_space *mapping,
                .pgio = &pgio,
        };
        struct inode *inode = mapping->host;
-       struct nfs_server *server = NFS_SERVER(inode);
-       size_t rsize = server->rsize;
        unsigned long npages;
        int ret = -ESTALE;
 
@@ -660,11 +680,7 @@ int nfs_readpages(struct file *filp, struct address_space *mapping,
        if (ret == 0)
                goto read_complete; /* all pages were read */
 
-       pnfs_pageio_init_read(&pgio, inode);
-       if (rsize < PAGE_CACHE_SIZE)
-               nfs_pageio_init(&pgio, inode, nfs_pagein_multi, rsize, 0);
-       else
-               nfs_pageio_init(&pgio, inode, nfs_pagein_one, rsize, 0);
+       nfs_pageio_init_read(&pgio, inode);
 
        ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc);