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/direct.c b/fs/nfs/direct.c
index f69d95a..fd7ac5e 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -154,6 +154,7 @@
struct list_head *list;
struct nfs_direct_req *dreq;
unsigned int reads = 0;
+ unsigned int rpages = (rsize + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
dreq = kmem_cache_alloc(nfs_direct_cachep, SLAB_KERNEL);
if (!dreq)
@@ -167,7 +168,7 @@
list = &dreq->list;
for(;;) {
- struct nfs_read_data *data = nfs_readdata_alloc();
+ struct nfs_read_data *data = nfs_readdata_alloc(rpages);
if (unlikely(!data)) {
while (!list_empty(list)) {
@@ -431,7 +432,7 @@
struct nfs_writeverf first_verf;
struct nfs_write_data *wdata;
- wdata = nfs_writedata_alloc();
+ wdata = nfs_writedata_alloc(NFS_SERVER(inode)->wpages);
if (!wdata)
return -ENOMEM;
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,
diff --git a/fs/nfs/nfsroot.c b/fs/nfs/nfsroot.c
index 1b272a1..985cc53 100644
--- a/fs/nfs/nfsroot.c
+++ b/fs/nfs/nfsroot.c
@@ -296,8 +296,8 @@
nfs_port = -1;
nfs_data.version = NFS_MOUNT_VERSION;
nfs_data.flags = NFS_MOUNT_NONLM; /* No lockd in nfs root yet */
- nfs_data.rsize = NFS_DEF_FILE_IO_BUFFER_SIZE;
- nfs_data.wsize = NFS_DEF_FILE_IO_BUFFER_SIZE;
+ nfs_data.rsize = NFS_DEF_FILE_IO_SIZE;
+ nfs_data.wsize = NFS_DEF_FILE_IO_SIZE;
nfs_data.acregmin = 3;
nfs_data.acregmax = 60;
nfs_data.acdirmin = 30;
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index 2148624..05eb43f 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -83,7 +83,7 @@
int result;
struct nfs_read_data *rdata;
- rdata = nfs_readdata_alloc();
+ rdata = nfs_readdata_alloc(1);
if (!rdata)
return -ENOMEM;
@@ -283,7 +283,7 @@
nbytes = req->wb_bytes;
for(;;) {
- data = nfs_readdata_alloc();
+ data = nfs_readdata_alloc(1);
if (!data)
goto out_bad;
INIT_LIST_HEAD(&data->pages);
@@ -339,7 +339,7 @@
if (NFS_SERVER(inode)->rsize < PAGE_CACHE_SIZE)
return nfs_pagein_multi(head, inode);
- data = nfs_readdata_alloc();
+ data = nfs_readdata_alloc(NFS_SERVER(inode)->rpages);
if (!data)
goto out_bad;
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 80bc4ea..1ce0c20 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -89,18 +89,33 @@
static DECLARE_WAIT_QUEUE_HEAD(nfs_write_congestion);
-static inline struct nfs_write_data *nfs_commit_alloc(void)
+static inline struct nfs_write_data *nfs_commit_alloc(unsigned int pagecount)
{
struct nfs_write_data *p = mempool_alloc(nfs_commit_mempool, SLAB_NOFS);
+
if (p) {
memset(p, 0, sizeof(*p));
INIT_LIST_HEAD(&p->pages);
+ if (pagecount < NFS_PAGEVEC_SIZE)
+ p->pagevec = &p->page_array[0];
+ else {
+ size_t size = ++pagecount * sizeof(struct page *);
+ p->pagevec = kmalloc(size, GFP_NOFS);
+ if (p->pagevec) {
+ memset(p->pagevec, 0, size);
+ } else {
+ mempool_free(p, nfs_commit_mempool);
+ p = NULL;
+ }
+ }
}
return p;
}
static inline void nfs_commit_free(struct nfs_write_data *p)
{
+ if (p && (p->pagevec != &p->page_array[0]))
+ kfree(p->pagevec);
mempool_free(p, nfs_commit_mempool);
}
@@ -167,7 +182,7 @@
int result, written = 0;
struct nfs_write_data *wdata;
- wdata = nfs_writedata_alloc();
+ wdata = nfs_writedata_alloc(1);
if (!wdata)
return -ENOMEM;
@@ -909,7 +924,7 @@
nbytes = req->wb_bytes;
for (;;) {
- data = nfs_writedata_alloc();
+ data = nfs_writedata_alloc(1);
if (!data)
goto out_bad;
list_add(&data->pages, &list);
@@ -973,7 +988,7 @@
if (NFS_SERVER(inode)->wsize < PAGE_CACHE_SIZE)
return nfs_flush_multi(head, inode, how);
- data = nfs_writedata_alloc();
+ data = nfs_writedata_alloc(NFS_SERVER(inode)->wpages);
if (!data)
goto out_bad;
@@ -1241,12 +1256,12 @@
* Commit dirty pages
*/
static int
-nfs_commit_list(struct list_head *head, int how)
+nfs_commit_list(struct inode *inode, struct list_head *head, int how)
{
struct nfs_write_data *data;
struct nfs_page *req;
- data = nfs_commit_alloc();
+ data = nfs_commit_alloc(NFS_SERVER(inode)->wpages);
if (!data)
goto out_bad;
@@ -1351,7 +1366,7 @@
res = nfs_scan_commit(inode, &head, 0, 0);
spin_unlock(&nfsi->req_lock);
if (res) {
- error = nfs_commit_list(&head, how);
+ error = nfs_commit_list(inode, &head, how);
if (error < 0)
return error;
}
diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 4dff705..d38010b 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -38,9 +38,6 @@
# define NFS_DEBUG
#endif
-#define NFS_MAX_FILE_IO_BUFFER_SIZE 32768
-#define NFS_DEF_FILE_IO_BUFFER_SIZE 4096
-
/* Default timeout values */
#define NFS_MAX_UDP_TIMEOUT (60*HZ)
#define NFS_MAX_TCP_TIMEOUT (600*HZ)
@@ -462,18 +459,33 @@
*/
extern mempool_t *nfs_wdata_mempool;
-static inline struct nfs_write_data *nfs_writedata_alloc(void)
+static inline struct nfs_write_data *nfs_writedata_alloc(unsigned int pagecount)
{
struct nfs_write_data *p = mempool_alloc(nfs_wdata_mempool, SLAB_NOFS);
+
if (p) {
memset(p, 0, sizeof(*p));
INIT_LIST_HEAD(&p->pages);
+ if (pagecount < NFS_PAGEVEC_SIZE)
+ p->pagevec = &p->page_array[0];
+ else {
+ size_t size = ++pagecount * sizeof(struct page *);
+ p->pagevec = kmalloc(size, GFP_NOFS);
+ if (p->pagevec) {
+ memset(p->pagevec, 0, size);
+ } else {
+ mempool_free(p, nfs_wdata_mempool);
+ p = NULL;
+ }
+ }
}
return p;
}
static inline void nfs_writedata_free(struct nfs_write_data *p)
{
+ if (p && (p->pagevec != &p->page_array[0]))
+ kfree(p->pagevec);
mempool_free(p, nfs_wdata_mempool);
}
@@ -492,16 +504,33 @@
*/
extern mempool_t *nfs_rdata_mempool;
-static inline struct nfs_read_data *nfs_readdata_alloc(void)
+static inline struct nfs_read_data *nfs_readdata_alloc(unsigned int pagecount)
{
struct nfs_read_data *p = mempool_alloc(nfs_rdata_mempool, SLAB_NOFS);
- if (p)
+
+ if (p) {
memset(p, 0, sizeof(*p));
+ INIT_LIST_HEAD(&p->pages);
+ if (pagecount < NFS_PAGEVEC_SIZE)
+ p->pagevec = &p->page_array[0];
+ else {
+ size_t size = ++pagecount * sizeof(struct page *);
+ p->pagevec = kmalloc(size, GFP_NOFS);
+ if (p->pagevec) {
+ memset(p->pagevec, 0, size);
+ } else {
+ mempool_free(p, nfs_rdata_mempool);
+ p = NULL;
+ }
+ }
+ }
return p;
}
static inline void nfs_readdata_free(struct nfs_read_data *p)
{
+ if (p && (p->pagevec != &p->page_array[0]))
+ kfree(p->pagevec);
mempool_free(p, nfs_rdata_mempool);
}
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index b8b0eed..9f422fd 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -4,6 +4,16 @@
#include <linux/sunrpc/xprt.h>
#include <linux/nfsacl.h>
+/*
+ * To change the maximum rsize and wsize supported by the NFS client, adjust
+ * NFS_MAX_FILE_IO_SIZE. 64KB is a typical maximum, but some servers can
+ * support a megabyte or more. The default is left at 4096 bytes, which is
+ * reasonable for NFS over UDP.
+ */
+#define NFS_MAX_FILE_IO_SIZE (1048576U)
+#define NFS_DEF_FILE_IO_SIZE (4096U)
+#define NFS_MIN_FILE_IO_SIZE (1024U)
+
struct nfs4_fsid {
__u64 major;
__u64 minor;
@@ -215,12 +225,6 @@
/*
* Arguments to the read call.
*/
-
-#define NFS_READ_MAXIOV (9U)
-#if (NFS_READ_MAXIOV > (MAX_IOVEC -2))
-#error "NFS_READ_MAXIOV is too large"
-#endif
-
struct nfs_readargs {
struct nfs_fh * fh;
struct nfs_open_context *context;
@@ -239,11 +243,6 @@
/*
* Arguments to the write call.
*/
-#define NFS_WRITE_MAXIOV (9U)
-#if (NFS_WRITE_MAXIOV > (MAX_IOVEC -2))
-#error "NFS_WRITE_MAXIOV is too large"
-#endif
-
struct nfs_writeargs {
struct nfs_fh * fh;
struct nfs_open_context *context;
@@ -674,6 +673,8 @@
struct nfs_page;
+#define NFS_PAGEVEC_SIZE (8U)
+
struct nfs_read_data {
int flags;
struct rpc_task task;
@@ -682,13 +683,14 @@
struct nfs_fattr fattr; /* fattr storage */
struct list_head pages; /* Coalesced read requests */
struct nfs_page *req; /* multi ops per nfs_page */
- struct page *pagevec[NFS_READ_MAXIOV];
+ struct page **pagevec;
struct nfs_readargs args;
struct nfs_readres res;
#ifdef CONFIG_NFS_V4
unsigned long timestamp; /* For lease renewal */
#endif
void (*complete) (struct nfs_read_data *, int);
+ struct page *page_array[NFS_PAGEVEC_SIZE + 1];
};
struct nfs_write_data {
@@ -700,13 +702,14 @@
struct nfs_writeverf verf;
struct list_head pages; /* Coalesced requests we wish to flush */
struct nfs_page *req; /* multi ops per nfs_page */
- struct page *pagevec[NFS_WRITE_MAXIOV];
+ struct page **pagevec;
struct nfs_writeargs args; /* argument struct */
struct nfs_writeres res; /* result struct */
#ifdef CONFIG_NFS_V4
unsigned long timestamp; /* For lease renewal */
#endif
void (*complete) (struct nfs_write_data *, int);
+ struct page *page_array[NFS_PAGEVEC_SIZE + 1];
};
struct nfs_access_entry;
diff --git a/include/linux/sunrpc/xdr.h b/include/linux/sunrpc/xdr.h
index 5da9687..5676794 100644
--- a/include/linux/sunrpc/xdr.h
+++ b/include/linux/sunrpc/xdr.h
@@ -135,11 +135,6 @@
}
/*
- * Maximum number of iov's we use.
- */
-#define MAX_IOVEC (12)
-
-/*
* XDR buffer helper functions
*/
extern void xdr_shift_buf(struct xdr_buf *, size_t);
