NFS: Create a common rw_header_alloc and rw_header_free function

I create a new struct nfs_rw_ops to decide the differences between reads
and writes.  This struct will be set when initializing a new
nfs_pgio_descriptor, and then passed on to the nfs_rw_header when a new
header is allocated.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

1 files changed, 33 insertions, 0 deletions

diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index a98ccf722d7b..ca356fe0836b 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -301,6 +301,37 @@ static inline struct nfs_rw_header *NFS_RW_HEADER(struct nfs_pgio_header *hdr)
 }
 
 /**
+ * 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;
+
+                INIT_LIST_HEAD(&hdr->pages);
+                INIT_LIST_HEAD(&hdr->rpc_list);
+                spin_lock_init(&hdr->lock);
+                atomic_set(&hdr->refcnt, 0);
+                hdr->rw_ops = ops;
+        }
+        return header;
+}
+EXPORT_SYMBOL_GPL(nfs_rw_header_alloc);
+
+/*
+ * nfs_rw_header_free - Free a read or write header
+ * @hdr: The header to free
+ */
+void nfs_rw_header_free(struct nfs_pgio_header *hdr)
+{
+        hdr->rw_ops->rw_free_header(NFS_RW_HEADER(hdr));
+}
+EXPORT_SYMBOL_GPL(nfs_rw_header_free);
+
+/**
  * nfs_pgio_data_alloc - Allocate pageio data
  * @hdr: The header making a request
  * @pagecount: Number of pages to create
@@ -367,6 +398,7 @@ void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
                      struct inode *inode,
                      const struct nfs_pageio_ops *pg_ops,
                      const struct nfs_pgio_completion_ops *compl_ops,
+                     const struct nfs_rw_ops *rw_ops,
                      size_t bsize,
                      int io_flags)
 {
@@ -380,6 +412,7 @@ void nfs_pageio_init(struct nfs_pageio_descriptor *desc,
         desc->pg_inode = inode;
         desc->pg_ops = pg_ops;
         desc->pg_completion_ops = compl_ops;
+        desc->pg_rw_ops = rw_ops;
         desc->pg_ioflags = io_flags;
         desc->pg_error = 0;
         desc->pg_lseg = NULL;