mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-06 04:46:39 +07:00
731 lines
18 KiB
C
731 lines
18 KiB
C
/*
|
|
* linux/fs/nfs/read.c
|
|
*
|
|
* Block I/O for NFS
|
|
*
|
|
* Partial copy of Linus' read cache modifications to fs/nfs/file.c
|
|
* modified for async RPC by okir@monad.swb.de
|
|
*
|
|
* We do an ugly hack here in order to return proper error codes to the
|
|
* user program when a read request failed: since generic_file_read
|
|
* only checks the return value of inode->i_op->readpage() which is always 0
|
|
* for async RPC, we set the error bit of the page to 1 when an error occurs,
|
|
* and make nfs_readpage transmit requests synchronously when encountering this.
|
|
* This is only a small problem, though, since we now retry all operations
|
|
* within the RPC code when root squashing is suspected.
|
|
*/
|
|
|
|
#include <linux/time.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/fcntl.h>
|
|
#include <linux/stat.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/pagemap.h>
|
|
#include <linux/sunrpc/clnt.h>
|
|
#include <linux/nfs_fs.h>
|
|
#include <linux/nfs_page.h>
|
|
#include <linux/smp_lock.h>
|
|
|
|
#include <asm/system.h>
|
|
|
|
#include "internal.h"
|
|
#include "iostat.h"
|
|
|
|
#define NFSDBG_FACILITY NFSDBG_PAGECACHE
|
|
|
|
static int nfs_pagein_one(struct list_head *, struct inode *);
|
|
static const struct rpc_call_ops nfs_read_partial_ops;
|
|
static const struct rpc_call_ops nfs_read_full_ops;
|
|
|
|
static struct kmem_cache *nfs_rdata_cachep;
|
|
static mempool_t *nfs_rdata_mempool;
|
|
|
|
#define MIN_POOL_READ (32)
|
|
|
|
struct nfs_read_data *nfs_readdata_alloc(size_t len)
|
|
{
|
|
unsigned int pagecount = (len + PAGE_SIZE - 1) >> PAGE_SHIFT;
|
|
struct nfs_read_data *p = mempool_alloc(nfs_rdata_mempool, GFP_NOFS);
|
|
|
|
if (p) {
|
|
memset(p, 0, sizeof(*p));
|
|
INIT_LIST_HEAD(&p->pages);
|
|
p->npages = pagecount;
|
|
if (pagecount <= ARRAY_SIZE(p->page_array))
|
|
p->pagevec = p->page_array;
|
|
else {
|
|
p->pagevec = kcalloc(pagecount, sizeof(struct page *), GFP_NOFS);
|
|
if (!p->pagevec) {
|
|
mempool_free(p, nfs_rdata_mempool);
|
|
p = NULL;
|
|
}
|
|
}
|
|
}
|
|
return p;
|
|
}
|
|
|
|
static void nfs_readdata_rcu_free(struct rcu_head *head)
|
|
{
|
|
struct nfs_read_data *p = container_of(head, struct nfs_read_data, task.u.tk_rcu);
|
|
if (p && (p->pagevec != &p->page_array[0]))
|
|
kfree(p->pagevec);
|
|
mempool_free(p, nfs_rdata_mempool);
|
|
}
|
|
|
|
static void nfs_readdata_free(struct nfs_read_data *rdata)
|
|
{
|
|
call_rcu_bh(&rdata->task.u.tk_rcu, nfs_readdata_rcu_free);
|
|
}
|
|
|
|
void nfs_readdata_release(void *data)
|
|
{
|
|
nfs_readdata_free(data);
|
|
}
|
|
|
|
static
|
|
int nfs_return_empty_page(struct page *page)
|
|
{
|
|
memclear_highpage_flush(page, 0, PAGE_CACHE_SIZE);
|
|
SetPageUptodate(page);
|
|
unlock_page(page);
|
|
return 0;
|
|
}
|
|
|
|
static void nfs_readpage_truncate_uninitialised_page(struct nfs_read_data *data)
|
|
{
|
|
unsigned int remainder = data->args.count - data->res.count;
|
|
unsigned int base = data->args.pgbase + data->res.count;
|
|
unsigned int pglen;
|
|
struct page **pages;
|
|
|
|
if (data->res.eof == 0 || remainder == 0)
|
|
return;
|
|
/*
|
|
* Note: "remainder" can never be negative, since we check for
|
|
* this in the XDR code.
|
|
*/
|
|
pages = &data->args.pages[base >> PAGE_CACHE_SHIFT];
|
|
base &= ~PAGE_CACHE_MASK;
|
|
pglen = PAGE_CACHE_SIZE - base;
|
|
for (;;) {
|
|
if (remainder <= pglen) {
|
|
memclear_highpage_flush(*pages, base, remainder);
|
|
break;
|
|
}
|
|
memclear_highpage_flush(*pages, base, pglen);
|
|
pages++;
|
|
remainder -= pglen;
|
|
pglen = PAGE_CACHE_SIZE;
|
|
base = 0;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Read a page synchronously.
|
|
*/
|
|
static int nfs_readpage_sync(struct nfs_open_context *ctx, struct inode *inode,
|
|
struct page *page)
|
|
{
|
|
unsigned int rsize = NFS_SERVER(inode)->rsize;
|
|
unsigned int count = PAGE_CACHE_SIZE;
|
|
int result = -ENOMEM;
|
|
struct nfs_read_data *rdata;
|
|
|
|
rdata = nfs_readdata_alloc(count);
|
|
if (!rdata)
|
|
goto out_unlock;
|
|
|
|
memset(rdata, 0, sizeof(*rdata));
|
|
rdata->flags = (IS_SWAPFILE(inode)? NFS_RPC_SWAPFLAGS : 0);
|
|
rdata->cred = ctx->cred;
|
|
rdata->inode = inode;
|
|
INIT_LIST_HEAD(&rdata->pages);
|
|
rdata->args.fh = NFS_FH(inode);
|
|
rdata->args.context = ctx;
|
|
rdata->args.pages = &page;
|
|
rdata->args.pgbase = 0UL;
|
|
rdata->args.count = rsize;
|
|
rdata->res.fattr = &rdata->fattr;
|
|
|
|
dprintk("NFS: nfs_readpage_sync(%p)\n", page);
|
|
|
|
/*
|
|
* This works now because the socket layer never tries to DMA
|
|
* into this buffer directly.
|
|
*/
|
|
do {
|
|
if (count < rsize)
|
|
rdata->args.count = count;
|
|
rdata->res.count = rdata->args.count;
|
|
rdata->args.offset = page_offset(page) + rdata->args.pgbase;
|
|
|
|
dprintk("NFS: nfs_proc_read(%s, (%s/%Ld), %Lu, %u)\n",
|
|
NFS_SERVER(inode)->nfs_client->cl_hostname,
|
|
inode->i_sb->s_id,
|
|
(long long)NFS_FILEID(inode),
|
|
(unsigned long long)rdata->args.pgbase,
|
|
rdata->args.count);
|
|
|
|
lock_kernel();
|
|
result = NFS_PROTO(inode)->read(rdata);
|
|
unlock_kernel();
|
|
|
|
/*
|
|
* Even if we had a partial success we can't mark the page
|
|
* cache valid.
|
|
*/
|
|
if (result < 0) {
|
|
if (result == -EISDIR)
|
|
result = -EINVAL;
|
|
goto io_error;
|
|
}
|
|
count -= result;
|
|
rdata->args.pgbase += result;
|
|
nfs_add_stats(inode, NFSIOS_SERVERREADBYTES, result);
|
|
|
|
/* Note: result == 0 should only happen if we're caching
|
|
* a write that extends the file and punches a hole.
|
|
*/
|
|
if (rdata->res.eof != 0 || result == 0)
|
|
break;
|
|
} while (count);
|
|
spin_lock(&inode->i_lock);
|
|
NFS_I(inode)->cache_validity |= NFS_INO_INVALID_ATIME;
|
|
spin_unlock(&inode->i_lock);
|
|
|
|
if (rdata->res.eof || rdata->res.count == rdata->args.count) {
|
|
SetPageUptodate(page);
|
|
if (rdata->res.eof && count != 0)
|
|
memclear_highpage_flush(page, rdata->args.pgbase, count);
|
|
}
|
|
result = 0;
|
|
|
|
io_error:
|
|
nfs_readdata_free(rdata);
|
|
out_unlock:
|
|
unlock_page(page);
|
|
return result;
|
|
}
|
|
|
|
static int nfs_readpage_async(struct nfs_open_context *ctx, struct inode *inode,
|
|
struct page *page)
|
|
{
|
|
LIST_HEAD(one_request);
|
|
struct nfs_page *new;
|
|
unsigned int len;
|
|
|
|
len = nfs_page_length(page);
|
|
if (len == 0)
|
|
return nfs_return_empty_page(page);
|
|
new = nfs_create_request(ctx, inode, page, 0, len);
|
|
if (IS_ERR(new)) {
|
|
unlock_page(page);
|
|
return PTR_ERR(new);
|
|
}
|
|
if (len < PAGE_CACHE_SIZE)
|
|
memclear_highpage_flush(page, len, PAGE_CACHE_SIZE - len);
|
|
|
|
nfs_list_add_request(new, &one_request);
|
|
nfs_pagein_one(&one_request, inode);
|
|
return 0;
|
|
}
|
|
|
|
static void nfs_readpage_release(struct nfs_page *req)
|
|
{
|
|
unlock_page(req->wb_page);
|
|
|
|
dprintk("NFS: read done (%s/%Ld %d@%Ld)\n",
|
|
req->wb_context->dentry->d_inode->i_sb->s_id,
|
|
(long long)NFS_FILEID(req->wb_context->dentry->d_inode),
|
|
req->wb_bytes,
|
|
(long long)req_offset(req));
|
|
nfs_clear_request(req);
|
|
nfs_release_request(req);
|
|
}
|
|
|
|
/*
|
|
* Set up the NFS read request struct
|
|
*/
|
|
static void nfs_read_rpcsetup(struct nfs_page *req, struct nfs_read_data *data,
|
|
const struct rpc_call_ops *call_ops,
|
|
unsigned int count, unsigned int offset)
|
|
{
|
|
struct inode *inode;
|
|
int flags;
|
|
|
|
data->req = req;
|
|
data->inode = inode = req->wb_context->dentry->d_inode;
|
|
data->cred = req->wb_context->cred;
|
|
|
|
data->args.fh = NFS_FH(inode);
|
|
data->args.offset = req_offset(req) + offset;
|
|
data->args.pgbase = req->wb_pgbase + offset;
|
|
data->args.pages = data->pagevec;
|
|
data->args.count = count;
|
|
data->args.context = req->wb_context;
|
|
|
|
data->res.fattr = &data->fattr;
|
|
data->res.count = count;
|
|
data->res.eof = 0;
|
|
nfs_fattr_init(&data->fattr);
|
|
|
|
/* Set up the initial task struct. */
|
|
flags = RPC_TASK_ASYNC | (IS_SWAPFILE(inode)? NFS_RPC_SWAPFLAGS : 0);
|
|
rpc_init_task(&data->task, NFS_CLIENT(inode), flags, call_ops, data);
|
|
NFS_PROTO(inode)->read_setup(data);
|
|
|
|
data->task.tk_cookie = (unsigned long)inode;
|
|
|
|
dprintk("NFS: %4d initiated read call (req %s/%Ld, %u bytes @ offset %Lu)\n",
|
|
data->task.tk_pid,
|
|
inode->i_sb->s_id,
|
|
(long long)NFS_FILEID(inode),
|
|
count,
|
|
(unsigned long long)data->args.offset);
|
|
}
|
|
|
|
static void
|
|
nfs_async_read_error(struct list_head *head)
|
|
{
|
|
struct nfs_page *req;
|
|
|
|
while (!list_empty(head)) {
|
|
req = nfs_list_entry(head->next);
|
|
nfs_list_remove_request(req);
|
|
SetPageError(req->wb_page);
|
|
nfs_readpage_release(req);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Start an async read operation
|
|
*/
|
|
static void nfs_execute_read(struct nfs_read_data *data)
|
|
{
|
|
struct rpc_clnt *clnt = NFS_CLIENT(data->inode);
|
|
sigset_t oldset;
|
|
|
|
rpc_clnt_sigmask(clnt, &oldset);
|
|
rpc_execute(&data->task);
|
|
rpc_clnt_sigunmask(clnt, &oldset);
|
|
}
|
|
|
|
/*
|
|
* Generate multiple requests to fill a single page.
|
|
*
|
|
* We optimize to reduce the number of read operations on the wire. If we
|
|
* detect that we're reading a page, or an area of a page, that is past the
|
|
* end of file, we do not generate NFS read operations but just clear the
|
|
* parts of the page that would have come back zero from the server anyway.
|
|
*
|
|
* We rely on the cached value of i_size to make this determination; another
|
|
* client can fill pages on the server past our cached end-of-file, but we
|
|
* won't see the new data until our attribute cache is updated. This is more
|
|
* or less conventional NFS client behavior.
|
|
*/
|
|
static int nfs_pagein_multi(struct list_head *head, struct inode *inode)
|
|
{
|
|
struct nfs_page *req = nfs_list_entry(head->next);
|
|
struct page *page = req->wb_page;
|
|
struct nfs_read_data *data;
|
|
size_t rsize = NFS_SERVER(inode)->rsize, nbytes;
|
|
unsigned int offset;
|
|
int requests = 0;
|
|
LIST_HEAD(list);
|
|
|
|
nfs_list_remove_request(req);
|
|
|
|
nbytes = req->wb_bytes;
|
|
do {
|
|
size_t len = min(nbytes,rsize);
|
|
|
|
data = nfs_readdata_alloc(len);
|
|
if (!data)
|
|
goto out_bad;
|
|
INIT_LIST_HEAD(&data->pages);
|
|
list_add(&data->pages, &list);
|
|
requests++;
|
|
nbytes -= len;
|
|
} while(nbytes != 0);
|
|
atomic_set(&req->wb_complete, requests);
|
|
|
|
ClearPageError(page);
|
|
offset = 0;
|
|
nbytes = req->wb_bytes;
|
|
do {
|
|
data = list_entry(list.next, struct nfs_read_data, pages);
|
|
list_del_init(&data->pages);
|
|
|
|
data->pagevec[0] = page;
|
|
|
|
if (nbytes > rsize) {
|
|
nfs_read_rpcsetup(req, data, &nfs_read_partial_ops,
|
|
rsize, offset);
|
|
offset += rsize;
|
|
nbytes -= rsize;
|
|
} else {
|
|
nfs_read_rpcsetup(req, data, &nfs_read_partial_ops,
|
|
nbytes, offset);
|
|
nbytes = 0;
|
|
}
|
|
nfs_execute_read(data);
|
|
} while (nbytes != 0);
|
|
|
|
return 0;
|
|
|
|
out_bad:
|
|
while (!list_empty(&list)) {
|
|
data = list_entry(list.next, struct nfs_read_data, pages);
|
|
list_del(&data->pages);
|
|
nfs_readdata_free(data);
|
|
}
|
|
SetPageError(page);
|
|
nfs_readpage_release(req);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
static int nfs_pagein_one(struct list_head *head, struct inode *inode)
|
|
{
|
|
struct nfs_page *req;
|
|
struct page **pages;
|
|
struct nfs_read_data *data;
|
|
unsigned int count;
|
|
|
|
if (NFS_SERVER(inode)->rsize < PAGE_CACHE_SIZE)
|
|
return nfs_pagein_multi(head, inode);
|
|
|
|
data = nfs_readdata_alloc(NFS_SERVER(inode)->rsize);
|
|
if (!data)
|
|
goto out_bad;
|
|
|
|
INIT_LIST_HEAD(&data->pages);
|
|
pages = data->pagevec;
|
|
count = 0;
|
|
while (!list_empty(head)) {
|
|
req = nfs_list_entry(head->next);
|
|
nfs_list_remove_request(req);
|
|
nfs_list_add_request(req, &data->pages);
|
|
ClearPageError(req->wb_page);
|
|
*pages++ = req->wb_page;
|
|
count += req->wb_bytes;
|
|
}
|
|
req = nfs_list_entry(data->pages.next);
|
|
|
|
nfs_read_rpcsetup(req, data, &nfs_read_full_ops, count, 0);
|
|
|
|
nfs_execute_read(data);
|
|
return 0;
|
|
out_bad:
|
|
nfs_async_read_error(head);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
static int
|
|
nfs_pagein_list(struct list_head *head, int rpages)
|
|
{
|
|
LIST_HEAD(one_request);
|
|
struct nfs_page *req;
|
|
int error = 0;
|
|
unsigned int pages = 0;
|
|
|
|
while (!list_empty(head)) {
|
|
pages += nfs_coalesce_requests(head, &one_request, rpages);
|
|
req = nfs_list_entry(one_request.next);
|
|
error = nfs_pagein_one(&one_request, req->wb_context->dentry->d_inode);
|
|
if (error < 0)
|
|
break;
|
|
}
|
|
if (error >= 0)
|
|
return pages;
|
|
|
|
nfs_async_read_error(head);
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* This is the callback from RPC telling us whether a reply was
|
|
* received or some error occurred (timeout or socket shutdown).
|
|
*/
|
|
int nfs_readpage_result(struct rpc_task *task, struct nfs_read_data *data)
|
|
{
|
|
int status;
|
|
|
|
dprintk("%s: %4d, (status %d)\n", __FUNCTION__, task->tk_pid,
|
|
task->tk_status);
|
|
|
|
status = NFS_PROTO(data->inode)->read_done(task, data);
|
|
if (status != 0)
|
|
return status;
|
|
|
|
nfs_add_stats(data->inode, NFSIOS_SERVERREADBYTES, data->res.count);
|
|
|
|
if (task->tk_status == -ESTALE) {
|
|
set_bit(NFS_INO_STALE, &NFS_FLAGS(data->inode));
|
|
nfs_mark_for_revalidate(data->inode);
|
|
}
|
|
spin_lock(&data->inode->i_lock);
|
|
NFS_I(data->inode)->cache_validity |= NFS_INO_INVALID_ATIME;
|
|
spin_unlock(&data->inode->i_lock);
|
|
return 0;
|
|
}
|
|
|
|
static int nfs_readpage_retry(struct rpc_task *task, struct nfs_read_data *data)
|
|
{
|
|
struct nfs_readargs *argp = &data->args;
|
|
struct nfs_readres *resp = &data->res;
|
|
|
|
if (resp->eof || resp->count == argp->count)
|
|
return 0;
|
|
|
|
/* This is a short read! */
|
|
nfs_inc_stats(data->inode, NFSIOS_SHORTREAD);
|
|
/* Has the server at least made some progress? */
|
|
if (resp->count == 0)
|
|
return 0;
|
|
|
|
/* Yes, so retry the read at the end of the data */
|
|
argp->offset += resp->count;
|
|
argp->pgbase += resp->count;
|
|
argp->count -= resp->count;
|
|
rpc_restart_call(task);
|
|
return -EAGAIN;
|
|
}
|
|
|
|
/*
|
|
* Handle a read reply that fills part of a page.
|
|
*/
|
|
static void nfs_readpage_result_partial(struct rpc_task *task, void *calldata)
|
|
{
|
|
struct nfs_read_data *data = calldata;
|
|
struct nfs_page *req = data->req;
|
|
struct page *page = req->wb_page;
|
|
|
|
if (nfs_readpage_result(task, data) != 0)
|
|
return;
|
|
|
|
if (likely(task->tk_status >= 0)) {
|
|
nfs_readpage_truncate_uninitialised_page(data);
|
|
if (nfs_readpage_retry(task, data) != 0)
|
|
return;
|
|
}
|
|
if (unlikely(task->tk_status < 0))
|
|
SetPageError(page);
|
|
if (atomic_dec_and_test(&req->wb_complete)) {
|
|
if (!PageError(page))
|
|
SetPageUptodate(page);
|
|
nfs_readpage_release(req);
|
|
}
|
|
}
|
|
|
|
static const struct rpc_call_ops nfs_read_partial_ops = {
|
|
.rpc_call_done = nfs_readpage_result_partial,
|
|
.rpc_release = nfs_readdata_release,
|
|
};
|
|
|
|
static void nfs_readpage_set_pages_uptodate(struct nfs_read_data *data)
|
|
{
|
|
unsigned int count = data->res.count;
|
|
unsigned int base = data->args.pgbase;
|
|
struct page **pages;
|
|
|
|
if (data->res.eof)
|
|
count = data->args.count;
|
|
if (unlikely(count == 0))
|
|
return;
|
|
pages = &data->args.pages[base >> PAGE_CACHE_SHIFT];
|
|
base &= ~PAGE_CACHE_MASK;
|
|
count += base;
|
|
for (;count >= PAGE_CACHE_SIZE; count -= PAGE_CACHE_SIZE, pages++)
|
|
SetPageUptodate(*pages);
|
|
if (count == 0)
|
|
return;
|
|
/* Was this a short read? */
|
|
if (data->res.eof || data->res.count == data->args.count)
|
|
SetPageUptodate(*pages);
|
|
}
|
|
|
|
/*
|
|
* This is the callback from RPC telling us whether a reply was
|
|
* received or some error occurred (timeout or socket shutdown).
|
|
*/
|
|
static void nfs_readpage_result_full(struct rpc_task *task, void *calldata)
|
|
{
|
|
struct nfs_read_data *data = calldata;
|
|
|
|
if (nfs_readpage_result(task, data) != 0)
|
|
return;
|
|
/*
|
|
* Note: nfs_readpage_retry may change the values of
|
|
* data->args. In the multi-page case, we therefore need
|
|
* to ensure that we call nfs_readpage_set_pages_uptodate()
|
|
* first.
|
|
*/
|
|
if (likely(task->tk_status >= 0)) {
|
|
nfs_readpage_truncate_uninitialised_page(data);
|
|
nfs_readpage_set_pages_uptodate(data);
|
|
if (nfs_readpage_retry(task, data) != 0)
|
|
return;
|
|
}
|
|
while (!list_empty(&data->pages)) {
|
|
struct nfs_page *req = nfs_list_entry(data->pages.next);
|
|
|
|
nfs_list_remove_request(req);
|
|
nfs_readpage_release(req);
|
|
}
|
|
}
|
|
|
|
static const struct rpc_call_ops nfs_read_full_ops = {
|
|
.rpc_call_done = nfs_readpage_result_full,
|
|
.rpc_release = nfs_readdata_release,
|
|
};
|
|
|
|
/*
|
|
* Read a page over NFS.
|
|
* We read the page synchronously in the following case:
|
|
* - The error flag is set for this page. This happens only when a
|
|
* previous async read operation failed.
|
|
*/
|
|
int nfs_readpage(struct file *file, struct page *page)
|
|
{
|
|
struct nfs_open_context *ctx;
|
|
struct inode *inode = page->mapping->host;
|
|
int error;
|
|
|
|
dprintk("NFS: nfs_readpage (%p %ld@%lu)\n",
|
|
page, PAGE_CACHE_SIZE, page->index);
|
|
nfs_inc_stats(inode, NFSIOS_VFSREADPAGE);
|
|
nfs_add_stats(inode, NFSIOS_READPAGES, 1);
|
|
|
|
/*
|
|
* Try to flush any pending writes to the file..
|
|
*
|
|
* NOTE! Because we own the page lock, there cannot
|
|
* be any new pending writes generated at this point
|
|
* for this page (other pages can be written to).
|
|
*/
|
|
error = nfs_wb_page(inode, page);
|
|
if (error)
|
|
goto out_error;
|
|
|
|
error = -ESTALE;
|
|
if (NFS_STALE(inode))
|
|
goto out_error;
|
|
|
|
if (file == NULL) {
|
|
error = -EBADF;
|
|
ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
|
|
if (ctx == NULL)
|
|
goto out_error;
|
|
} else
|
|
ctx = get_nfs_open_context((struct nfs_open_context *)
|
|
file->private_data);
|
|
if (!IS_SYNC(inode)) {
|
|
error = nfs_readpage_async(ctx, inode, page);
|
|
goto out;
|
|
}
|
|
|
|
error = nfs_readpage_sync(ctx, inode, page);
|
|
if (error < 0 && IS_SWAPFILE(inode))
|
|
printk("Aiee.. nfs swap-in of page failed!\n");
|
|
out:
|
|
put_nfs_open_context(ctx);
|
|
return error;
|
|
|
|
out_error:
|
|
unlock_page(page);
|
|
return error;
|
|
}
|
|
|
|
struct nfs_readdesc {
|
|
struct list_head *head;
|
|
struct nfs_open_context *ctx;
|
|
};
|
|
|
|
static int
|
|
readpage_async_filler(void *data, struct page *page)
|
|
{
|
|
struct nfs_readdesc *desc = (struct nfs_readdesc *)data;
|
|
struct inode *inode = page->mapping->host;
|
|
struct nfs_page *new;
|
|
unsigned int len;
|
|
|
|
nfs_wb_page(inode, page);
|
|
len = nfs_page_length(page);
|
|
if (len == 0)
|
|
return nfs_return_empty_page(page);
|
|
new = nfs_create_request(desc->ctx, inode, page, 0, len);
|
|
if (IS_ERR(new)) {
|
|
SetPageError(page);
|
|
unlock_page(page);
|
|
return PTR_ERR(new);
|
|
}
|
|
if (len < PAGE_CACHE_SIZE)
|
|
memclear_highpage_flush(page, len, PAGE_CACHE_SIZE - len);
|
|
nfs_list_add_request(new, desc->head);
|
|
return 0;
|
|
}
|
|
|
|
int nfs_readpages(struct file *filp, struct address_space *mapping,
|
|
struct list_head *pages, unsigned nr_pages)
|
|
{
|
|
LIST_HEAD(head);
|
|
struct nfs_readdesc desc = {
|
|
.head = &head,
|
|
};
|
|
struct inode *inode = mapping->host;
|
|
struct nfs_server *server = NFS_SERVER(inode);
|
|
int ret = -ESTALE;
|
|
|
|
dprintk("NFS: nfs_readpages (%s/%Ld %d)\n",
|
|
inode->i_sb->s_id,
|
|
(long long)NFS_FILEID(inode),
|
|
nr_pages);
|
|
nfs_inc_stats(inode, NFSIOS_VFSREADPAGES);
|
|
|
|
if (NFS_STALE(inode))
|
|
goto out;
|
|
|
|
if (filp == NULL) {
|
|
desc.ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
|
|
if (desc.ctx == NULL)
|
|
return -EBADF;
|
|
} else
|
|
desc.ctx = get_nfs_open_context((struct nfs_open_context *)
|
|
filp->private_data);
|
|
ret = read_cache_pages(mapping, pages, readpage_async_filler, &desc);
|
|
if (!list_empty(&head)) {
|
|
int err = nfs_pagein_list(&head, server->rpages);
|
|
if (!ret)
|
|
nfs_add_stats(inode, NFSIOS_READPAGES, err);
|
|
ret = err;
|
|
}
|
|
put_nfs_open_context(desc.ctx);
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
int __init nfs_init_readpagecache(void)
|
|
{
|
|
nfs_rdata_cachep = kmem_cache_create("nfs_read_data",
|
|
sizeof(struct nfs_read_data),
|
|
0, SLAB_HWCACHE_ALIGN,
|
|
NULL, NULL);
|
|
if (nfs_rdata_cachep == NULL)
|
|
return -ENOMEM;
|
|
|
|
nfs_rdata_mempool = mempool_create_slab_pool(MIN_POOL_READ,
|
|
nfs_rdata_cachep);
|
|
if (nfs_rdata_mempool == NULL)
|
|
return -ENOMEM;
|
|
|
|
return 0;
|
|
}
|
|
|
|
void nfs_destroy_readpagecache(void)
|
|
{
|
|
mempool_destroy(nfs_rdata_mempool);
|
|
kmem_cache_destroy(nfs_rdata_cachep);
|
|
}
|