nfs/localio: remove extra indirect nfs_to call to check {read,write}_iter

Push the read_iter and write_iter availability checks down to
nfs_do_local_read and nfs_do_local_write respectively.

This eliminates a redundant nfs_to->nfsd_file_file() call.

Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

diff --git a/fs/nfs/localio.c b/fs/nfs/localio.c
index 153e00e..23f6d2a 100644 (file)
--- a/fs/nfs/localio.c
+++ b/fs/nfs/localio.c
@@ -273,7 +273,7 @@ nfs_local_iocb_free(struct nfs_local_kiocb *iocb)
 
 static struct nfs_local_kiocb *
 nfs_local_iocb_alloc(struct nfs_pgio_header *hdr,
-                    struct nfsd_file *localio, gfp_t flags)
+                    struct file *file, gfp_t flags)
 {
        struct nfs_local_kiocb *iocb;
 
@@ -286,9 +286,8 @@ nfs_local_iocb_alloc(struct nfs_pgio_header *hdr,
                kfree(iocb);
                return NULL;
        }
-       init_sync_kiocb(&iocb->kiocb, nfs_to->nfsd_file_file(localio));
+       init_sync_kiocb(&iocb->kiocb, file);
        iocb->kiocb.ki_pos = hdr->args.offset;
-       iocb->localio = localio;
        iocb->hdr = hdr;
        iocb->kiocb.ki_flags &= ~IOCB_APPEND;
        return iocb;
@@ -389,13 +388,19 @@ nfs_do_local_read(struct nfs_pgio_header *hdr,
                  const struct rpc_call_ops *call_ops)
 {
        struct nfs_local_kiocb *iocb;
+       struct file *file = nfs_to->nfsd_file_file(localio);
+
+       /* Don't support filesystems without read_iter */
+       if (!file->f_op->read_iter)
+               return -EAGAIN;
 
        dprintk("%s: vfs_read count=%u pos=%llu\n",
                __func__, hdr->args.count, hdr->args.offset);
 
-       iocb = nfs_local_iocb_alloc(hdr, localio, GFP_KERNEL);
+       iocb = nfs_local_iocb_alloc(hdr, file, GFP_KERNEL);
        if (iocb == NULL)
                return -ENOMEM;
+       iocb->localio = localio;
 
        nfs_local_pgio_init(hdr, call_ops);
        hdr->res.eof = false;
@@ -558,14 +563,20 @@ nfs_do_local_write(struct nfs_pgio_header *hdr,
                   const struct rpc_call_ops *call_ops)
 {
        struct nfs_local_kiocb *iocb;
+       struct file *file = nfs_to->nfsd_file_file(localio);
+
+       /* Don't support filesystems without write_iter */
+       if (!file->f_op->write_iter)
+               return -EAGAIN;
 
        dprintk("%s: vfs_write count=%u pos=%llu %s\n",
                __func__, hdr->args.count, hdr->args.offset,
                (hdr->args.stable == NFS_UNSTABLE) ?  "unstable" : "stable");
 
-       iocb = nfs_local_iocb_alloc(hdr, localio, GFP_NOIO);
+       iocb = nfs_local_iocb_alloc(hdr, file, GFP_NOIO);
        if (iocb == NULL)
                return -ENOMEM;
+       iocb->localio = localio;
 
        switch (hdr->args.stable) {
        default:
@@ -591,16 +602,9 @@ int nfs_local_doio(struct nfs_client *clp, struct nfsd_file *localio,
                   const struct rpc_call_ops *call_ops)
 {
        int status = 0;
-       struct file *filp = nfs_to->nfsd_file_file(localio);
 
        if (!hdr->args.count)
                return 0;
-       /* Don't support filesystems without read_iter/write_iter */
-       if (!filp->f_op->read_iter || !filp->f_op->write_iter) {
-               nfs_local_disable(clp);
-               status = -EAGAIN;
-               goto out;
-       }
 
        switch (hdr->rw_mode) {
        case FMODE_READ:
@@ -614,8 +618,10 @@ int nfs_local_doio(struct nfs_client *clp, struct nfsd_file *localio,
                        hdr->rw_mode);
                status = -EINVAL;
        }
-out:
+
        if (status != 0) {
+               if (status == -EAGAIN)
+                       nfs_local_disable(clp);
                nfs_to_nfsd_file_put_local(localio);
                hdr->task.tk_status = status;
                nfs_local_hdr_release(hdr, call_ops);