nfs: move nfs_pgio_data and remove nfs_rw_header

nfs_rw_header was used to allocate an nfs_pgio_header along with an
nfs_pgio_data, because a _header would need at least one _data.

Now there is only ever one nfs_pgio_data for each nfs_pgio_header -- move
it to nfs_pgio_header and get rid of nfs_rw_header.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

1 files changed, 28 insertions, 66 deletions

diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index b6ee3a6ee96d..e4cde476562f 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -452,95 +452,61 @@ size_t nfs_generic_pg_test(struct nfs_pageio_descriptor *desc,
 }
 EXPORT_SYMBOL_GPL(nfs_generic_pg_test);
 
-static inline struct nfs_rw_header *NFS_RW_HEADER(struct nfs_pgio_header *hdr)
+struct nfs_pgio_header *nfs_pgio_header_alloc(const struct nfs_rw_ops *ops)
 {
-        return container_of(hdr, struct nfs_rw_header, header);
-}
-
-/**
- * nfs_rw_header_alloc - Allocate a header for a read or write
- * @ops: Read or write function vector
- */
-struct nfs_rw_header *nfs_rw_header_alloc(const struct nfs_rw_ops *ops)
-{
-        struct nfs_rw_header *header = ops->rw_alloc_header();
-
-        if (header) {
-                struct nfs_pgio_header *hdr = &header->header;
+        struct nfs_pgio_header *hdr = ops->rw_alloc_header();
 
+        if (hdr) {
                 INIT_LIST_HEAD(&hdr->pages);
                 spin_lock_init(&hdr->lock);
                 atomic_set(&hdr->refcnt, 0);
                 hdr->rw_ops = ops;
         }
-        return header;
+        return hdr;
 }
-EXPORT_SYMBOL_GPL(nfs_rw_header_alloc);
+EXPORT_SYMBOL_GPL(nfs_pgio_header_alloc);
 
 /*
- * nfs_rw_header_free - Free a read or write header
+ * nfs_pgio_header_free - Free a read or write header
  * @hdr: The header to free
  */
-void nfs_rw_header_free(struct nfs_pgio_header *hdr)
+void nfs_pgio_header_free(struct nfs_pgio_header *hdr)
 {
-        hdr->rw_ops->rw_free_header(NFS_RW_HEADER(hdr));
+        hdr->rw_ops->rw_free_header(hdr);
 }
-EXPORT_SYMBOL_GPL(nfs_rw_header_free);
+EXPORT_SYMBOL_GPL(nfs_pgio_header_free);
 
 /**
  * nfs_pgio_data_alloc - Allocate pageio data
  * @hdr: The header making a request
  * @pagecount: Number of pages to create
  */
-static struct nfs_pgio_data *nfs_pgio_data_alloc(struct nfs_pgio_header *hdr,
-                                                 unsigned int pagecount)
+static bool nfs_pgio_data_init(struct nfs_pgio_header *hdr,
+                               unsigned int pagecount)
 {
-        struct nfs_pgio_data *data, *prealloc;
-
-        prealloc = &NFS_RW_HEADER(hdr)->rpc_data;
-        if (prealloc->header == NULL)
-                data = prealloc;
-        else
-                data = kzalloc(sizeof(*data), GFP_KERNEL);
-        if (!data)
-                goto out;
-
-        if (nfs_pgarray_set(&data->pages, pagecount)) {
-                data->header = hdr;
+        if (nfs_pgarray_set(&hdr->data.pages, pagecount)) {
+                hdr->data.header = hdr;
                 atomic_inc(&hdr->refcnt);
-        } else {
-                if (data != prealloc)
-                        kfree(data);
-                data = NULL;
+                return true;
         }
-out:
-        return data;
+        return false;
 }
 
 /**
- * nfs_pgio_data_release - Properly free pageio data
- * @data: The data to release
+ * nfs_pgio_data_destroy - Properly free pageio data
+ * @data: The data to destroy
  */
-void nfs_pgio_data_release(struct nfs_pgio_data *data)
+void nfs_pgio_data_destroy(struct nfs_pgio_data *data)
 {
         struct nfs_pgio_header *hdr = data->header;
-        struct nfs_rw_header *pageio_header = NFS_RW_HEADER(hdr);
 
         put_nfs_open_context(data->args.context);
         if (data->pages.pagevec != data->pages.page_array)
                 kfree(data->pages.pagevec);
-        if (data == &pageio_header->rpc_data) {
-                data->header = NULL;
-                data = NULL;
-        }
         if (atomic_dec_and_test(&hdr->refcnt))
                 hdr->completion_ops->completion(hdr);
-        /* Note: we only free the rpc_task after callbacks are done.
-         * See the comment in rpc_free_task() for why
-         */
-        kfree(data);
 }
-EXPORT_SYMBOL_GPL(nfs_pgio_data_release);
+EXPORT_SYMBOL_GPL(nfs_pgio_data_destroy);
 
 /**
  * nfs_pgio_rpcsetup - Set up arguments for a pageio call
@@ -655,8 +621,7 @@ static int nfs_pgio_error(struct nfs_pageio_descriptor *desc,
                           struct nfs_pgio_header *hdr)
 {
         set_bit(NFS_IOHDR_REDO, &hdr->flags);
-        nfs_pgio_data_release(hdr->data);
-        hdr->data = NULL;
+        nfs_pgio_data_destroy(&hdr->data);
         desc->pg_completion_ops->error_cleanup(&desc->pg_list);
         return -ENOMEM;
 }
@@ -670,7 +635,7 @@ static void nfs_pgio_release(void *calldata)
         struct nfs_pgio_data *data = calldata;
         if (data->header->rw_ops->rw_release)
                 data->header->rw_ops->rw_release(data);
-        nfs_pgio_data_release(data);
+        nfs_pgio_data_destroy(data);
 }
 
 /**
@@ -746,11 +711,11 @@ int nfs_generic_pgio(struct nfs_pageio_descriptor *desc,
         struct list_head *head = &desc->pg_list;
         struct nfs_commit_info cinfo;
 
-        data = nfs_pgio_data_alloc(hdr, nfs_page_array_len(desc->pg_base,
-                                                           desc->pg_count));
-        if (!data)
+        if (!nfs_pgio_data_init(hdr, nfs_page_array_len(desc->pg_base,
+                           desc->pg_count)))
                 return nfs_pgio_error(desc, hdr);
 
+        data = &hdr->data;
         nfs_init_cinfo(&cinfo, desc->pg_inode, desc->pg_dreq);
         pages = data->pages.pagevec;
         while (!list_empty(head)) {
@@ -766,7 +731,6 @@ int nfs_generic_pgio(struct nfs_pageio_descriptor *desc,
 
         /* Set up the argument struct */
         nfs_pgio_rpcsetup(data, desc->pg_count, 0, desc->pg_ioflags, &cinfo);
-        hdr->data = data;
         desc->pg_rpc_callops = &nfs_pgio_common_ops;
         return 0;
 }
@@ -774,22 +738,20 @@ EXPORT_SYMBOL_GPL(nfs_generic_pgio);
 
 static int nfs_generic_pg_pgios(struct nfs_pageio_descriptor *desc)
 {
-        struct nfs_rw_header *rw_hdr;
         struct nfs_pgio_header *hdr;
         int ret;
 
-        rw_hdr = nfs_rw_header_alloc(desc->pg_rw_ops);
-        if (!rw_hdr) {
+        hdr = nfs_pgio_header_alloc(desc->pg_rw_ops);
+        if (!hdr) {
                 desc->pg_completion_ops->error_cleanup(&desc->pg_list);
                 return -ENOMEM;
         }
-        hdr = &rw_hdr->header;
-        nfs_pgheader_init(desc, hdr, nfs_rw_header_free);
+        nfs_pgheader_init(desc, hdr, nfs_pgio_header_free);
         atomic_inc(&hdr->refcnt);
         ret = nfs_generic_pgio(desc, hdr);
         if (ret == 0)
                 ret = nfs_initiate_pgio(NFS_CLIENT(hdr->inode),
-                                        hdr->data, desc->pg_rpc_callops,
+                                        &hdr->data, desc->pg_rpc_callops,
                                         desc->pg_ioflags, 0);
         if (atomic_dec_and_test(&hdr->refcnt))
                 hdr->completion_ops->completion(hdr);