NFS: Optimise away the sigmask code in aio/dio reads and writes

There are no interruptible waits for asynchronous RPC tasks, so we don't
need to wrap calls to rpc_run_task() with an
rpc_clnt_sigmask/rpc_clnt_unsigmask pair.

Instead we can wrap the wait_for_completion_interruptible() in
nfs_direct_wait(). This means that we completely optimise away sigmask
setting for the case of non-blocking aio/dio.

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

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index eadd87f7159f164a79f70322ae06c03f7337f744..f8e165c7d5a637de762e619e1ddd1a7db4436fb7 100644 (file)
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -188,12 +188,17 @@ static void nfs_direct_req_release(struct nfs_direct_req *dreq)
 static ssize_t nfs_direct_wait(struct nfs_direct_req *dreq)
 {
        ssize_t result = -EIOCBQUEUED;
+       struct rpc_clnt *clnt;
+       sigset_t oldset;
 
        /* Async requests don't wait here */
        if (dreq->iocb)
                goto out;
 
+       clnt = NFS_CLIENT(dreq->inode);
+       rpc_clnt_sigmask(clnt, &oldset);
        result = wait_for_completion_interruptible(&dreq->completion);
+       rpc_clnt_sigunmask(clnt, &oldset);
 
        if (!result)
                result = dreq->error;
@@ -403,9 +408,7 @@ static ssize_t nfs_direct_read(struct kiocb *iocb, const struct iovec *iov,
                               unsigned long nr_segs, loff_t pos)
 {
        ssize_t result = 0;
-       sigset_t oldset;
        struct inode *inode = iocb->ki_filp->f_mapping->host;
-       struct rpc_clnt *clnt = NFS_CLIENT(inode);
        struct nfs_direct_req *dreq;
 
        dreq = nfs_direct_req_alloc();
@@ -417,11 +420,9 @@ static ssize_t nfs_direct_read(struct kiocb *iocb, const struct iovec *iov,
        if (!is_sync_kiocb(iocb))
                dreq->iocb = iocb;
 
-       rpc_clnt_sigmask(clnt, &oldset);
        result = nfs_direct_read_schedule_iovec(dreq, iov, nr_segs, pos);
        if (!result)
                result = nfs_direct_wait(dreq);
-       rpc_clnt_sigunmask(clnt, &oldset);
        nfs_direct_req_release(dreq);
 
        return result;
@@ -816,9 +817,7 @@ static ssize_t nfs_direct_write(struct kiocb *iocb, const struct iovec *iov,
                                size_t count)
 {
        ssize_t result = 0;
-       sigset_t oldset;
        struct inode *inode = iocb->ki_filp->f_mapping->host;
-       struct rpc_clnt *clnt = NFS_CLIENT(inode);
        struct nfs_direct_req *dreq;
        size_t wsize = NFS_SERVER(inode)->wsize;
        int sync = NFS_UNSTABLE;
@@ -836,11 +835,9 @@ static ssize_t nfs_direct_write(struct kiocb *iocb, const struct iovec *iov,
        if (!is_sync_kiocb(iocb))
                dreq->iocb = iocb;
 
-       rpc_clnt_sigmask(clnt, &oldset);
        result = nfs_direct_write_schedule_iovec(dreq, iov, nr_segs, pos, sync);
        if (!result)
                result = nfs_direct_wait(dreq);
-       rpc_clnt_sigunmask(clnt, &oldset);
        nfs_direct_req_release(dreq);
 
        return result;