NFS: Cleanup for nfs_readpages()

Do the coalescing of read requests into block sized requests at start of
I/O as we scan through the pages instead of going through a second pass.

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

2 files changed, 17 insertions, 34 deletions

diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 528128545d66..094537ddd344 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -342,8 +342,8 @@ static void nfs_pageio_doio(struct nfs_pageio_descriptor *desc)
  * Returns true if the request 'req' was successfully coalesced into the
  * existing list of pages 'desc'.
  */
-static int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
-                                  struct nfs_page *req)
+int nfs_pageio_add_request(struct nfs_pageio_descriptor *desc,
+                           struct nfs_page *req)
 {
         while (!nfs_pageio_do_add_request(desc, req)) {
                 nfs_pageio_doio(desc);
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index 0effa74992df..f0016062340d 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -321,28 +321,6 @@ out_bad:
         return -ENOMEM;
 }
 
-static int
-nfs_pagein_list(struct inode *inode, struct list_head *head, unsigned int rsize)
-{
-        struct nfs_pageio_descriptor desc;
-        unsigned int pages = 0;
-        int error = 0;
-
-        if (rsize < PAGE_CACHE_SIZE)
-                nfs_pageio_init(&desc, inode, nfs_pagein_multi, rsize, 0);
-        else
-                nfs_pageio_init(&desc, inode, nfs_pagein_one, rsize, 0);
-
-        nfs_pageio_add_list(&desc, head);
-        nfs_pageio_complete(&desc);
-        pages += (desc.pg_bytes_written + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
-
-        nfs_async_read_error(head);
-        if (error >= 0)
-                return pages;
-        return error;
-}
-
 /*
  * This is the callback from RPC telling us whether a reply was
  * received or some error occurred (timeout or socket shutdown).
@@ -532,7 +510,7 @@ out_error:
 }
 
 struct nfs_readdesc {
-        struct list_head *head;
+        struct nfs_pageio_descriptor *pgio;
         struct nfs_open_context *ctx;
 };
 
@@ -556,19 +534,21 @@ readpage_async_filler(void *data, struct page *page)
         }
         if (len < PAGE_CACHE_SIZE)
                 memclear_highpage_flush(page, len, PAGE_CACHE_SIZE - len);
-        nfs_list_add_request(new, desc->head);
+        nfs_pageio_add_request(desc->pgio, new);
         return 0;
 }
 
 int nfs_readpages(struct file *filp, struct address_space *mapping,
                 struct list_head *pages, unsigned nr_pages)
 {
-        LIST_HEAD(head);
+        struct nfs_pageio_descriptor pgio;
         struct nfs_readdesc desc = {
-                .head           = &head,
+                .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;
 
         dprintk("NFS: nfs_readpages (%s/%Ld %d)\n",
@@ -587,13 +567,16 @@ int nfs_readpages(struct file *filp, struct address_space *mapping,
         } else
                 desc.ctx = get_nfs_open_context((struct nfs_open_context *)
                                 filp->private_data);
+        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);
+
         ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc);
-        if (!list_empty(&head)) {
-                int err = nfs_pagein_list(inode, &head, server->rsize);
-                if (!ret)
-                        nfs_add_stats(inode, NFSIOS_READPAGES, err);
-                        ret = err;
-        }
+
+        nfs_pageio_complete(&pgio);
+        npages = (pgio.pg_bytes_written + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+        nfs_add_stats(inode, NFSIOS_READPAGES, npages);
         put_nfs_open_context(desc.ctx);
 out:
         return ret;