1 files changed, 81 insertions, 46 deletions

diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index aedcaa7f291f..7cded2b12a05 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -18,19 +18,20 @@
 #include <linux/sunrpc/clnt.h>
 #include <linux/nfs_fs.h>
 #include <linux/nfs_page.h>
+#include <linux/module.h>
 
 #include <asm/system.h>
+#include "pnfs.h"
 
 #include "nfs4_fs.h"
 #include "internal.h"
 #include "iostat.h"
 #include "fscache.h"
-#include "pnfs.h"
 
 #define NFSDBG_FACILITY         NFSDBG_PAGECACHE
 
-static int nfs_pagein_multi(struct inode *, struct list_head *, unsigned int, size_t, int);
-static int nfs_pagein_one(struct inode *, struct list_head *, unsigned int, size_t, int);
+static int nfs_pagein_multi(struct nfs_pageio_descriptor *desc);
+static int nfs_pagein_one(struct nfs_pageio_descriptor *desc);
 static const struct rpc_call_ops nfs_read_partial_ops;
 static const struct rpc_call_ops nfs_read_full_ops;
 
@@ -69,6 +70,7 @@ void nfs_readdata_free(struct nfs_read_data *p)
 
 static void nfs_readdata_release(struct nfs_read_data *rdata)
 {
+        put_lseg(rdata->lseg);
         put_nfs_open_context(rdata->args.context);
         nfs_readdata_free(rdata);
 }
@@ -114,14 +116,13 @@ static void nfs_readpage_truncate_uninitialised_page(struct nfs_read_data *data)
 int nfs_readpage_async(struct nfs_open_context *ctx, struct inode *inode,
                        struct page *page)
 {
-        LIST_HEAD(one_request);
         struct nfs_page *new;
         unsigned int len;
+        struct nfs_pageio_descriptor pgio;
 
         len = nfs_page_length(page);
         if (len == 0)
                 return nfs_return_empty_page(page);
-        pnfs_update_layout(inode, ctx, IOMODE_READ);
         new = nfs_create_request(ctx, inode, page, 0, len);
         if (IS_ERR(new)) {
                 unlock_page(page);
@@ -130,11 +131,14 @@ 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_list_add_request(new, &one_request);
+        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(inode, &one_request, 1, len, 0);
+                nfs_pagein_multi(&pgio);
         else
-                nfs_pagein_one(inode, &one_request, 1, len, 0);
+                nfs_pagein_one(&pgio);
         return 0;
 }
 
@@ -155,24 +159,20 @@ static void nfs_readpage_release(struct nfs_page *req)
         nfs_release_request(req);
 }
 
-/*
- * Set up the NFS read request struct
- */
-static int nfs_read_rpcsetup(struct nfs_page *req, struct nfs_read_data *data,
-                const struct rpc_call_ops *call_ops,
-                unsigned int count, unsigned int offset)
+int nfs_initiate_read(struct nfs_read_data *data, struct rpc_clnt *clnt,
+                      const struct rpc_call_ops *call_ops)
 {
-        struct inode *inode = req->wb_context->path.dentry->d_inode;
+        struct inode *inode = data->inode;
         int swap_flags = IS_SWAPFILE(inode) ? NFS_RPC_SWAPFLAGS : 0;
         struct rpc_task *task;
         struct rpc_message msg = {
                 .rpc_argp = &data->args,
                 .rpc_resp = &data->res,
-                .rpc_cred = req->wb_context->cred,
+                .rpc_cred = data->cred,
         };
         struct rpc_task_setup task_setup_data = {
                 .task = &data->task,
-                .rpc_client = NFS_CLIENT(inode),
+                .rpc_client = clnt,
                 .rpc_message = &msg,
                 .callback_ops = call_ops,
                 .callback_data = data,
@@ -180,9 +180,39 @@ static int nfs_read_rpcsetup(struct nfs_page *req, struct nfs_read_data *data,
                 .flags = RPC_TASK_ASYNC | swap_flags,
         };
 
+        /* Set up the initial task struct. */
+        NFS_PROTO(inode)->read_setup(data, &msg);
+
+        dprintk("NFS: %5u initiated read call (req %s/%lld, %u bytes @ "
+                        "offset %llu)\n",
+                        data->task.tk_pid,
+                        inode->i_sb->s_id,
+                        (long long)NFS_FILEID(inode),
+                        data->args.count,
+                        (unsigned long long)data->args.offset);
+
+        task = rpc_run_task(&task_setup_data);
+        if (IS_ERR(task))
+                return PTR_ERR(task);
+        rpc_put_task(task);
+        return 0;
+}
+EXPORT_SYMBOL_GPL(nfs_initiate_read);
+
+/*
+ * Set up the NFS read request struct
+ */
+static int nfs_read_rpcsetup(struct nfs_page *req, struct nfs_read_data *data,
+                const struct rpc_call_ops *call_ops,
+                unsigned int count, unsigned int offset,
+                struct pnfs_layout_segment *lseg)
+{
+        struct inode *inode = req->wb_context->path.dentry->d_inode;
+
         data->req         = req;
         data->inode       = inode;
-        data->cred        = msg.rpc_cred;
+        data->cred        = req->wb_context->cred;
+        data->lseg        = get_lseg(lseg);
 
         data->args.fh     = NFS_FH(inode);
         data->args.offset = req_offset(req) + offset;
@@ -197,21 +227,11 @@ static int nfs_read_rpcsetup(struct nfs_page *req, struct nfs_read_data *data,
         data->res.eof     = 0;
         nfs_fattr_init(&data->fattr);
 
-        /* Set up the initial task struct. */
-        NFS_PROTO(inode)->read_setup(data, &msg);
-
-        dprintk("NFS: %5u initiated read call (req %s/%Ld, %u bytes @ offset %Lu)\n",
-                        data->task.tk_pid,
-                        inode->i_sb->s_id,
-                        (long long)NFS_FILEID(inode),
-                        count,
-                        (unsigned long long)data->args.offset);
+        if (data->lseg &&
+            (pnfs_try_to_read_data(data, call_ops) == PNFS_ATTEMPTED))
+                return 0;
 
-        task = rpc_run_task(&task_setup_data);
-        if (IS_ERR(task))
-                return PTR_ERR(task);
-        rpc_put_task(task);
-        return 0;
+        return nfs_initiate_read(data, NFS_CLIENT(inode), call_ops);
 }
 
 static void
@@ -240,20 +260,21 @@ nfs_async_read_error(struct list_head *head)
  * won't see the new data until our attribute cache is updated.  This is more
  * or less conventional NFS client behavior.
  */
-static int nfs_pagein_multi(struct inode *inode, struct list_head *head, unsigned int npages, size_t count, int flags)
+static int nfs_pagein_multi(struct nfs_pageio_descriptor *desc)
 {
-        struct nfs_page *req = nfs_list_entry(head->next);
+        struct nfs_page *req = nfs_list_entry(desc->pg_list.next);
         struct page *page = req->wb_page;
         struct nfs_read_data *data;
-        size_t rsize = NFS_SERVER(inode)->rsize, nbytes;
+        size_t rsize = NFS_SERVER(desc->pg_inode)->rsize, nbytes;
         unsigned int offset;
         int requests = 0;
         int ret = 0;
+        struct pnfs_layout_segment *lseg;
         LIST_HEAD(list);
 
         nfs_list_remove_request(req);
 
-        nbytes = count;
+        nbytes = desc->pg_count;
         do {
                 size_t len = min(nbytes,rsize);
 
@@ -266,9 +287,11 @@ static int nfs_pagein_multi(struct inode *inode, struct list_head *head, unsigne
         } 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);
         ClearPageError(page);
         offset = 0;
-        nbytes = count;
+        nbytes = desc->pg_count;
         do {
                 int ret2;
 
@@ -280,12 +303,14 @@ static int nfs_pagein_multi(struct inode *inode, struct list_head *head, unsigne
                 if (nbytes < rsize)
                         rsize = nbytes;
                 ret2 = nfs_read_rpcsetup(req, data, &nfs_read_partial_ops,
-                                  rsize, offset);
+                                         rsize, offset, lseg);
                 if (ret == 0)
                         ret = ret2;
                 offset += rsize;
                 nbytes -= rsize;
         } while (nbytes != 0);
+        put_lseg(lseg);
+        desc->pg_lseg = NULL;
 
         return ret;
 
@@ -300,16 +325,21 @@ out_bad:
         return -ENOMEM;
 }
 
-static int nfs_pagein_one(struct inode *inode, struct list_head *head, unsigned int npages, size_t count, int flags)
+static int nfs_pagein_one(struct nfs_pageio_descriptor *desc)
 {
         struct nfs_page         *req;
         struct page             **pages;
         struct nfs_read_data    *data;
+        struct list_head *head = &desc->pg_list;
+        struct pnfs_layout_segment *lseg = desc->pg_lseg;
         int ret = -ENOMEM;
 
-        data = nfs_readdata_alloc(npages);
-        if (!data)
-                goto out_bad;
+        data = nfs_readdata_alloc(nfs_page_array_len(desc->pg_base,
+                                                     desc->pg_count));
+        if (!data) {
+                nfs_async_read_error(head);
+                goto out;
+        }
 
         pages = data->pagevec;
         while (!list_empty(head)) {
@@ -320,10 +350,14 @@ static int nfs_pagein_one(struct inode *inode, struct list_head *head, unsigned
                 *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);
 
-        return nfs_read_rpcsetup(req, data, &nfs_read_full_ops, count, 0);
-out_bad:
-        nfs_async_read_error(head);
+        ret = nfs_read_rpcsetup(req, data, &nfs_read_full_ops, desc->pg_count,
+                                0, lseg);
+out:
+        put_lseg(lseg);
+        desc->pg_lseg = NULL;
         return ret;
 }
 
@@ -366,6 +400,7 @@ static void nfs_readpage_retry(struct rpc_task *task, struct nfs_read_data *data
                 return;
 
         /* Yes, so retry the read at the end of the data */
+        data->mds_offset += resp->count;
         argp->offset += resp->count;
         argp->pgbase += resp->count;
         argp->count -= resp->count;
@@ -625,7 +660,7 @@ int nfs_readpages(struct file *filp, struct address_space *mapping,
         if (ret == 0)
                 goto read_complete; /* all pages were read */
 
-        pnfs_update_layout(inode, desc.ctx, IOMODE_READ);
+        pnfs_pageio_init_read(&pgio, inode);
         if (rsize < PAGE_CACHE_SIZE)
                 nfs_pageio_init(&pgio, inode, nfs_pagein_multi, rsize, 0);
         else