NFS: support large reads and writes on the wire
Most NFS server implementations allow up to 64KB reads and writes on the
wire. The Solaris NFS server allows up to a megabyte, for instance.
Now the Linux NFS client supports transfer sizes up to 1MB, too. This will
help reduce protocol and context switch overhead on read/write intensive NFS
workloads, and support larger atomic read and write operations on servers
that support them.
Test-plan:
Connectathon and iozone on mount point with wsize=rsize>32768 over TCP.
Tests with NFS over UDP to verify the maximum RPC payload size cap.
Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 4e6558d..acde2c5 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -221,10 +221,10 @@
static inline unsigned long
nfs_block_size(unsigned long bsize, unsigned char *nrbitsp)
{
- if (bsize < 1024)
- bsize = NFS_DEF_FILE_IO_BUFFER_SIZE;
- else if (bsize >= NFS_MAX_FILE_IO_BUFFER_SIZE)
- bsize = NFS_MAX_FILE_IO_BUFFER_SIZE;
+ if (bsize < NFS_MIN_FILE_IO_SIZE)
+ bsize = NFS_DEF_FILE_IO_SIZE;
+ else if (bsize >= NFS_MAX_FILE_IO_SIZE)
+ bsize = NFS_MAX_FILE_IO_SIZE;
return nfs_block_bits(bsize, nrbitsp);
}
@@ -307,20 +307,15 @@
max_rpc_payload = nfs_block_size(rpc_max_payload(server->client), NULL);
if (server->rsize > max_rpc_payload)
server->rsize = max_rpc_payload;
+ if (server->rsize > NFS_MAX_FILE_IO_SIZE)
+ server->rsize = NFS_MAX_FILE_IO_SIZE;
+ server->rpages = (server->rsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+
if (server->wsize > max_rpc_payload)
server->wsize = max_rpc_payload;
-
- server->rpages = (server->rsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
- if (server->rpages > NFS_READ_MAXIOV) {
- server->rpages = NFS_READ_MAXIOV;
- server->rsize = server->rpages << PAGE_CACHE_SHIFT;
- }
-
+ if (server->wsize > NFS_MAX_FILE_IO_SIZE)
+ server->wsize = NFS_MAX_FILE_IO_SIZE;
server->wpages = (server->wsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
- if (server->wpages > NFS_WRITE_MAXIOV) {
- server->wpages = NFS_WRITE_MAXIOV;
- server->wsize = server->wpages << PAGE_CACHE_SHIFT;
- }
if (sb->s_blocksize == 0)
sb->s_blocksize = nfs_block_bits(server->wsize,