2008-01-25 17:02:05

by Myklebust, Trond

[permalink] [raw]
Subject: [PATCH 106/112] 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 <[email protected]>
---

fs/nfs/direct.c | 13 +++++--------
1 files changed, 5 insertions(+), 8 deletions(-)

diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index eadd87f..f8e165c 100644
--- 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;