NFS: create common nfs_pgio_header for both read and write
In order to avoid duplicating all the data in nfs_read_data whenever we
split it up into multiple RPC calls (either due to a short read result
or due to rsize < PAGE_SIZE), we split out the bits that are the same
per RPC call into a separate "header" structure.
The goal this patch moves towards is to have a single header
refcounted by several rpc_data structures. Thus, want to always refer
from rpc_data to the header, and not the other way. This patch comes
close to that ideal, but the directio code currently needs some
special casing, isolated in the nfs_direct_[read_write]hdr_release()
functions. This will be dealt with in a future patch.
Signed-off-by: Fred Isaman <iisaman@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index 4ddba67..d6d4682 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -35,19 +35,24 @@
static struct kmem_cache *nfs_rdata_cachep;
-struct nfs_read_data *nfs_readdata_alloc(unsigned int pagecount)
+struct nfs_read_header *nfs_readhdr_alloc(unsigned int pagecount)
{
- struct nfs_read_data *p;
+ struct nfs_read_header *p;
p = kmem_cache_zalloc(nfs_rdata_cachep, GFP_KERNEL);
if (p) {
- INIT_LIST_HEAD(&p->pages);
- p->npages = pagecount;
- if (pagecount <= ARRAY_SIZE(p->page_array))
- p->pagevec = p->page_array;
+ struct nfs_pgio_header *hdr = &p->header;
+ struct nfs_read_data *data = &p->rpc_data;
+
+ INIT_LIST_HEAD(&hdr->pages);
+ INIT_LIST_HEAD(&data->list);
+ data->npages = pagecount;
+ data->header = hdr;
+ if (pagecount <= ARRAY_SIZE(data->page_array))
+ data->pagevec = data->page_array;
else {
- p->pagevec = kcalloc(pagecount, sizeof(struct page *), GFP_KERNEL);
- if (!p->pagevec) {
+ data->pagevec = kcalloc(pagecount, sizeof(struct page *), GFP_KERNEL);
+ if (!data->pagevec) {
kmem_cache_free(nfs_rdata_cachep, p);
p = NULL;
}
@@ -56,17 +61,19 @@
return p;
}
-void nfs_readdata_free(struct nfs_read_data *p)
+void nfs_readhdr_free(struct nfs_pgio_header *hdr)
{
- if (p && (p->pagevec != &p->page_array[0]))
- kfree(p->pagevec);
- kmem_cache_free(nfs_rdata_cachep, p);
+ struct nfs_read_header *rhdr = container_of(hdr, struct nfs_read_header, header);
+
+ kmem_cache_free(nfs_rdata_cachep, rhdr);
}
void nfs_readdata_release(struct nfs_read_data *rdata)
{
put_nfs_open_context(rdata->args.context);
- nfs_readdata_free(rdata);
+ if (rdata->pagevec != rdata->page_array)
+ kfree(rdata->pagevec);
+ nfs_readhdr_free(rdata->header);
}
static
@@ -173,13 +180,13 @@
struct nfs_read_data *data,
const struct rpc_call_ops *call_ops)
{
- struct inode *inode = data->inode;
+ struct inode *inode = data->header->inode;
int swap_flags = IS_SWAPFILE(inode) ? NFS_RPC_SWAPFLAGS : 0;
struct rpc_task *task;
struct rpc_message msg = {
.rpc_argp = &data->args,
.rpc_resp = &data->res,
- .rpc_cred = data->cred,
+ .rpc_cred = data->header->cred,
};
struct rpc_task_setup task_setup_data = {
.task = &data->task,
@@ -216,11 +223,11 @@
static void nfs_read_rpcsetup(struct nfs_page *req, struct nfs_read_data *data,
unsigned int count, unsigned int offset)
{
- struct inode *inode = req->wb_context->dentry->d_inode;
+ struct inode *inode = data->header->inode;
- data->req = req;
- data->inode = inode;
- data->cred = req->wb_context->cred;
+ data->header->req = req;
+ data->header->inode = inode;
+ data->header->cred = req->wb_context->cred;
data->args.fh = NFS_FH(inode);
data->args.offset = req_offset(req) + offset;
@@ -239,7 +246,7 @@
static int nfs_do_read(struct nfs_read_data *data,
const struct rpc_call_ops *call_ops)
{
- struct inode *inode = data->args.context->dentry->d_inode;
+ struct inode *inode = data->header->inode;
return nfs_initiate_read(NFS_CLIENT(inode), data, call_ops);
}
@@ -293,6 +300,7 @@
{
struct nfs_page *req = nfs_list_entry(desc->pg_list.next);
struct page *page = req->wb_page;
+ struct nfs_read_header *rhdr;
struct nfs_read_data *data;
size_t rsize = desc->pg_bsize, nbytes;
unsigned int offset;
@@ -306,9 +314,10 @@
do {
size_t len = min(nbytes,rsize);
- data = nfs_readdata_alloc(1);
- if (!data)
+ rhdr = nfs_readhdr_alloc(1);
+ if (!rhdr)
goto out_bad;
+ data = &rhdr->rpc_data;
data->pagevec[0] = page;
nfs_read_rpcsetup(req, data, len, offset);
list_add(&data->list, res);
@@ -333,26 +342,28 @@
{
struct nfs_page *req;
struct page **pages;
+ struct nfs_read_header *rhdr;
struct nfs_read_data *data;
struct list_head *head = &desc->pg_list;
int ret = 0;
- data = nfs_readdata_alloc(nfs_page_array_len(desc->pg_base,
- desc->pg_count));
- if (!data) {
+ rhdr = nfs_readhdr_alloc(nfs_page_array_len(desc->pg_base,
+ desc->pg_count));
+ if (!rhdr) {
nfs_async_read_error(head);
ret = -ENOMEM;
goto out;
}
+ data = &rhdr->rpc_data;
pages = data->pagevec;
while (!list_empty(head)) {
req = nfs_list_entry(head->next);
nfs_list_remove_request(req);
- nfs_list_add_request(req, &data->pages);
+ nfs_list_add_request(req, &rhdr->header.pages);
*pages++ = req->wb_page;
}
- req = nfs_list_entry(data->pages.next);
+ req = nfs_list_entry(rhdr->header.pages.next);
nfs_read_rpcsetup(req, data, desc->pg_count, 0);
list_add(&data->list, res);
@@ -390,20 +401,21 @@
*/
int nfs_readpage_result(struct rpc_task *task, struct nfs_read_data *data)
{
+ struct inode *inode = data->header->inode;
int status;
dprintk("NFS: %s: %5u, (status %d)\n", __func__, task->tk_pid,
task->tk_status);
- status = NFS_PROTO(data->inode)->read_done(task, data);
+ status = NFS_PROTO(inode)->read_done(task, data);
if (status != 0)
return status;
- nfs_add_stats(data->inode, NFSIOS_SERVERREADBYTES, data->res.count);
+ nfs_add_stats(inode, NFSIOS_SERVERREADBYTES, data->res.count);
if (task->tk_status == -ESTALE) {
- set_bit(NFS_INO_STALE, &NFS_I(data->inode)->flags);
- nfs_mark_for_revalidate(data->inode);
+ set_bit(NFS_INO_STALE, &NFS_I(inode)->flags);
+ nfs_mark_for_revalidate(inode);
}
return 0;
}
@@ -417,7 +429,7 @@
return;
/* This is a short read! */
- nfs_inc_stats(data->inode, NFSIOS_SHORTREAD);
+ nfs_inc_stats(data->header->inode, NFSIOS_SHORTREAD);
/* Has the server at least made some progress? */
if (resp->count == 0)
return;
@@ -449,7 +461,7 @@
static void nfs_readpage_release_partial(void *calldata)
{
struct nfs_read_data *data = calldata;
- struct nfs_page *req = data->req;
+ struct nfs_page *req = data->header->req;
struct page *page = req->wb_page;
int status = data->task.tk_status;
@@ -461,13 +473,13 @@
SetPageUptodate(page);
nfs_readpage_release(req);
}
- nfs_readdata_release(calldata);
+ nfs_readdata_release(data);
}
void nfs_read_prepare(struct rpc_task *task, void *calldata)
{
struct nfs_read_data *data = calldata;
- NFS_PROTO(data->inode)->read_rpc_prepare(task, data);
+ NFS_PROTO(data->header->inode)->read_rpc_prepare(task, data);
}
static const struct rpc_call_ops nfs_read_partial_ops = {
@@ -524,9 +536,10 @@
static void nfs_readpage_release_full(void *calldata)
{
struct nfs_read_data *data = calldata;
+ struct nfs_pgio_header *hdr = data->header;
- while (!list_empty(&data->pages)) {
- struct nfs_page *req = nfs_list_entry(data->pages.next);
+ while (!list_empty(&hdr->pages)) {
+ struct nfs_page *req = nfs_list_entry(hdr->pages.next);
nfs_list_remove_request(req);
nfs_readpage_release(req);
@@ -685,7 +698,7 @@
int __init nfs_init_readpagecache(void)
{
nfs_rdata_cachep = kmem_cache_create("nfs_read_data",
- sizeof(struct nfs_read_data),
+ sizeof(struct nfs_read_header),
0, SLAB_HWCACHE_ALIGN,
NULL);
if (nfs_rdata_cachep == NULL)