nfs: remove ->read_pageio_init from rpc ops

The read_pageio_init method is just a very convoluted way to grab the
right nfs_pageio_ops vector.  The vector to chose is not a choice of
protocol version, but just a pNFS vs MDS I/O choice that can simply be
done inside nfs_pageio_init_read based on the presence of a layout
driver, and a new force_mds flag to the special case of falling back
to MDS I/O on a pNFS-capable volume.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

9 files changed, 17 insertions, 35 deletions

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 6a31102b0819..bbe688e2cc89 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -424,7 +424,7 @@ static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq,
         size_t requested_bytes = 0;
         unsigned long seg;
 
-        NFS_PROTO(dreq->inode)->read_pageio_init(&desc, dreq->inode,
+        nfs_pageio_init_read(&desc, dreq->inode, false,
                              &nfs_direct_read_completion_ops);
         get_dreq(dreq);
         desc.pg_dreq = dreq;
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 8431083de179..98fe618db2aa 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -398,7 +398,7 @@ struct nfs_pgio_completion_ops;
 extern struct nfs_read_header *nfs_readhdr_alloc(void);
 extern void nfs_readhdr_free(struct nfs_pgio_header *hdr);
 extern void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
-                        struct inode *inode,
+                        struct inode *inode, bool force_mds,
                         const struct nfs_pgio_completion_ops *compl_ops);
 extern int nfs_initiate_read(struct rpc_clnt *clnt,
                              struct nfs_read_data *data,
diff --git a/fs/nfs/nfs3proc.c b/fs/nfs/nfs3proc.c
index e98488053906..d873241a9b3a 100644
--- a/fs/nfs/nfs3proc.c
+++ b/fs/nfs/nfs3proc.c
@@ -947,7 +947,6 @@ const struct nfs_rpc_ops nfs_v3_clientops = {
         .pathconf       = nfs3_proc_pathconf,
         .decode_dirent  = nfs3_decode_dirent,
         .read_setup     = nfs3_proc_read_setup,
-        .read_pageio_init = nfs_pageio_init_read,
         .read_rpc_prepare = nfs3_proc_read_rpc_prepare,
         .read_done      = nfs3_read_done,
         .write_setup    = nfs3_proc_write_setup,
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 8da0c62966b5..21cd1f2ee35a 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -8433,7 +8433,6 @@ const struct nfs_rpc_ops nfs_v4_clientops = {
         .set_capabilities = nfs4_server_capabilities,
         .decode_dirent  = nfs4_decode_dirent,
         .read_setup     = nfs4_proc_read_setup,
-        .read_pageio_init = pnfs_pageio_init_read,
         .read_rpc_prepare = nfs4_proc_read_rpc_prepare,
         .read_done      = nfs4_read_done,
         .write_setup    = nfs4_proc_write_setup,
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 9edac9f01c2a..3d5bc2baafd1 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -1434,19 +1434,6 @@ pnfs_generic_pg_init_write(struct nfs_pageio_descriptor *pgio,
 }
 EXPORT_SYMBOL_GPL(pnfs_generic_pg_init_write);
 
-void
-pnfs_pageio_init_read(struct nfs_pageio_descriptor *pgio, struct inode *inode,
-                      const struct nfs_pgio_completion_ops *compl_ops)
-{
-        struct nfs_server *server = NFS_SERVER(inode);
-        struct pnfs_layoutdriver_type *ld = server->pnfs_curr_ld;
-
-        if (ld == NULL)
-                nfs_pageio_init_read(pgio, inode, compl_ops);
-        else
-                nfs_pageio_init(pgio, inode, ld->pg_read_ops, compl_ops, server->rsize, 0);
-}
-
 bool
 pnfs_generic_pg_test(struct nfs_pageio_descriptor *pgio, struct nfs_page *prev,
                      struct nfs_page *req)
@@ -1641,7 +1628,7 @@ int pnfs_read_done_resend_to_mds(struct inode *inode,
         LIST_HEAD(failed);
 
         /* Resend all requests through the MDS */
-        nfs_pageio_init_read(&pgio, inode, compl_ops);
+        nfs_pageio_init_read(&pgio, inode, true, compl_ops);
         pgio.pg_dreq = dreq;
         while (!list_empty(head)) {
                 struct nfs_page *req = nfs_list_entry(head->next);
diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h
index e9ac8fbaee3d..94a9a1834b3f 100644
--- a/fs/nfs/pnfs.h
+++ b/fs/nfs/pnfs.h
@@ -180,9 +180,6 @@ extern int nfs4_proc_layoutreturn(struct nfs4_layoutreturn *lrp);
 void pnfs_get_layout_hdr(struct pnfs_layout_hdr *lo);
 void pnfs_put_lseg(struct pnfs_layout_segment *lseg);
 
-void pnfs_pageio_init_read(struct nfs_pageio_descriptor *, struct inode *,
-                           const struct nfs_pgio_completion_ops *);
-
 void set_pnfs_layoutdriver(struct nfs_server *, const struct nfs_fh *, u32);
 void unset_pnfs_layoutdriver(struct nfs_server *);
 void pnfs_generic_pg_init_read(struct nfs_pageio_descriptor *, struct nfs_page *);
@@ -459,12 +456,6 @@ static inline void unset_pnfs_layoutdriver(struct nfs_server *s)
 {
 }
 
-static inline void pnfs_pageio_init_read(struct nfs_pageio_descriptor *pgio, struct inode *inode,
-                                         const struct nfs_pgio_completion_ops *compl_ops)
-{
-        nfs_pageio_init_read(pgio, inode, compl_ops);
-}
-
 static inline int
 pnfs_commit_list(struct inode *inode, struct list_head *mds_pages, int how,
                  struct nfs_commit_info *cinfo)
diff --git a/fs/nfs/proc.c b/fs/nfs/proc.c
index f9cc29590a18..8cc227fcd4d2 100644
--- a/fs/nfs/proc.c
+++ b/fs/nfs/proc.c
@@ -735,7 +735,6 @@ const struct nfs_rpc_ops nfs_v2_clientops = {
         .pathconf       = nfs_proc_pathconf,
         .decode_dirent  = nfs2_decode_dirent,
         .read_setup     = nfs_proc_read_setup,
-        .read_pageio_init = nfs_pageio_init_read,
         .read_rpc_prepare = nfs_proc_read_rpc_prepare,
         .read_done      = nfs_read_done,
         .write_setup    = nfs_proc_write_setup,
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index 411aedda14bb..7f87461be3a9 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -24,6 +24,7 @@
 #include "internal.h"
 #include "iostat.h"
 #include "fscache.h"
+#include "pnfs.h"
 
 #define NFSDBG_FACILITY         NFSDBG_PAGECACHE
 
@@ -114,11 +115,17 @@ int nfs_return_empty_page(struct page *page)
 }
 
 void nfs_pageio_init_read(struct nfs_pageio_descriptor *pgio,
-                              struct inode *inode,
+                              struct inode *inode, bool force_mds,
                               const struct nfs_pgio_completion_ops *compl_ops)
 {
-        nfs_pageio_init(pgio, inode, &nfs_pageio_read_ops, compl_ops,
-                        NFS_SERVER(inode)->rsize, 0);
+        struct nfs_server *server = NFS_SERVER(inode);
+        const struct nfs_pageio_ops *pg_ops = &nfs_pageio_read_ops;
+
+#ifdef CONFIG_NFS_V4_1
+        if (server->pnfs_curr_ld && !force_mds)
+                pg_ops = server->pnfs_curr_ld->pg_read_ops;
+#endif
+        nfs_pageio_init(pgio, inode, pg_ops, compl_ops, server->rsize, 0);
 }
 EXPORT_SYMBOL_GPL(nfs_pageio_init_read);
 
@@ -147,7 +154,8 @@ 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_PROTO(inode)->read_pageio_init(&pgio, inode, &nfs_async_read_completion_ops);
+        nfs_pageio_init_read(&pgio, inode, false,
+                             &nfs_async_read_completion_ops);
         nfs_pageio_add_request(&pgio, new);
         nfs_pageio_complete(&pgio);
         NFS_I(inode)->read_io += pgio.pg_bytes_written;
@@ -654,7 +662,8 @@ int nfs_readpages(struct file *filp, struct address_space *mapping,
         if (ret == 0)
                 goto read_complete; /* all pages were read */
 
-        NFS_PROTO(inode)->read_pageio_init(&pgio, inode, &nfs_async_read_completion_ops);
+        nfs_pageio_init_read(&pgio, inode, false,
+                             &nfs_async_read_completion_ops);
 
         ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc);
 
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 78216f859527..3e8fc1fe585b 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -1466,8 +1466,6 @@ struct nfs_rpc_ops {
         int     (*set_capabilities)(struct nfs_server *, struct nfs_fh *);
         int     (*decode_dirent)(struct xdr_stream *, struct nfs_entry *, int);
         void    (*read_setup)   (struct nfs_read_data *, struct rpc_message *);
-        void    (*read_pageio_init)(struct nfs_pageio_descriptor *, struct inode *,
-                                    const struct nfs_pgio_completion_ops *);
         int     (*read_rpc_prepare)(struct rpc_task *, struct nfs_read_data *);
         int     (*read_done)  (struct rpc_task *, struct nfs_read_data *);
         void    (*write_setup)  (struct nfs_write_data *, struct rpc_message *);