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Diffstat (limited to 'fs/nfs/read.c')
-rw-r--r--fs/nfs/read.c179
1 files changed, 84 insertions, 95 deletions
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index 244a8c45b68..a9c26521a9e 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -30,6 +30,7 @@
#include <asm/system.h>
+#include "internal.h"
#include "iostat.h"
#define NFSDBG_FACILITY NFSDBG_PAGECACHE
@@ -65,32 +66,22 @@ struct nfs_read_data *nfs_readdata_alloc(size_t len)
return p;
}
-static void nfs_readdata_free(struct nfs_read_data *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);
}
-void nfs_readdata_release(void *data)
+static void nfs_readdata_free(struct nfs_read_data *rdata)
{
- nfs_readdata_free(data);
+ call_rcu_bh(&rdata->task.u.tk_rcu, nfs_readdata_rcu_free);
}
-static
-unsigned int nfs_page_length(struct inode *inode, struct page *page)
+void nfs_readdata_release(void *data)
{
- loff_t i_size = i_size_read(inode);
- unsigned long idx;
-
- if (i_size <= 0)
- return 0;
- idx = (i_size - 1) >> PAGE_CACHE_SHIFT;
- if (page->index > idx)
- return 0;
- if (page->index != idx)
- return PAGE_CACHE_SIZE;
- return 1 + ((i_size - 1) & (PAGE_CACHE_SIZE - 1));
+ nfs_readdata_free(data);
}
static
@@ -139,12 +130,12 @@ static int nfs_readpage_sync(struct nfs_open_context *ctx, struct inode *inode,
{
unsigned int rsize = NFS_SERVER(inode)->rsize;
unsigned int count = PAGE_CACHE_SIZE;
- int result;
+ int result = -ENOMEM;
struct nfs_read_data *rdata;
rdata = nfs_readdata_alloc(count);
if (!rdata)
- return -ENOMEM;
+ goto out_unlock;
memset(rdata, 0, sizeof(*rdata));
rdata->flags = (IS_SWAPFILE(inode)? NFS_RPC_SWAPFLAGS : 0);
@@ -212,8 +203,9 @@ static int nfs_readpage_sync(struct nfs_open_context *ctx, struct inode *inode,
result = 0;
io_error:
- unlock_page(page);
nfs_readdata_free(rdata);
+out_unlock:
+ unlock_page(page);
return result;
}
@@ -224,7 +216,7 @@ static int nfs_readpage_async(struct nfs_open_context *ctx, struct inode *inode,
struct nfs_page *new;
unsigned int len;
- len = nfs_page_length(inode, page);
+ len = nfs_page_length(page);
if (len == 0)
return nfs_return_empty_page(page);
new = nfs_create_request(ctx, inode, page, 0, len);
@@ -316,9 +308,7 @@ static void nfs_execute_read(struct nfs_read_data *data)
sigset_t oldset;
rpc_clnt_sigmask(clnt, &oldset);
- lock_kernel();
rpc_execute(&data->task);
- unlock_kernel();
rpc_clnt_sigunmask(clnt, &oldset);
}
@@ -455,6 +445,55 @@ nfs_pagein_list(struct list_head *head, int rpages)
}
/*
+ * 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)
@@ -463,12 +502,16 @@ static void nfs_readpage_result_partial(struct rpc_task *task, void *calldata)
struct nfs_page *req = data->req;
struct page *page = req->wb_page;
- if (likely(task->tk_status >= 0))
- nfs_readpage_truncate_uninitialised_page(data);
- else
- SetPageError(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);
@@ -496,25 +539,13 @@ static void nfs_readpage_set_pages_uptodate(struct nfs_read_data *data)
count += base;
for (;count >= PAGE_CACHE_SIZE; count -= PAGE_CACHE_SIZE, pages++)
SetPageUptodate(*pages);
- if (count != 0)
+ if (count == 0)
+ return;
+ /* Was this a short read? */
+ if (data->res.eof || data->res.count == data->args.count)
SetPageUptodate(*pages);
}
-static void nfs_readpage_set_pages_error(struct nfs_read_data *data)
-{
- unsigned int count = data->args.count;
- unsigned int base = data->args.pgbase;
- struct page **pages;
-
- pages = &data->args.pages[base >> PAGE_CACHE_SHIFT];
- base &= ~PAGE_CACHE_MASK;
- count += base;
- for (;count >= PAGE_CACHE_SIZE; count -= PAGE_CACHE_SIZE, pages++)
- SetPageError(*pages);
- if (count != 0)
- SetPageError(*pages);
-}
-
/*
* This is the callback from RPC telling us whether a reply was
* received or some error occurred (timeout or socket shutdown).
@@ -523,19 +554,20 @@ 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_result may change the values of
+ * Note: nfs_readpage_retry may change the values of
* data->args. In the multi-page case, we therefore need
- * to ensure that we call the next nfs_readpage_set_page_uptodate()
- * first in the multi-page case.
+ * 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);
- } else
- nfs_readpage_set_pages_error(data);
- if (nfs_readpage_result(task, data) != 0)
- return;
+ if (nfs_readpage_retry(task, data) != 0)
+ return;
+ }
while (!list_empty(&data->pages)) {
struct nfs_page *req = nfs_list_entry(data->pages.next);
@@ -550,50 +582,6 @@ static const struct rpc_call_ops nfs_read_full_ops = {
};
/*
- * 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)
-{
- struct nfs_readargs *argp = &data->args;
- struct nfs_readres *resp = &data->res;
- int status;
-
- dprintk("NFS: %4d nfs_readpage_result, (status %d)\n",
- 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, resp->count);
-
- if (task->tk_status < 0) {
- if (task->tk_status == -ESTALE) {
- set_bit(NFS_INO_STALE, &NFS_FLAGS(data->inode));
- nfs_mark_for_revalidate(data->inode);
- }
- } else if (resp->count < argp->count && !resp->eof) {
- /* This is a short read! */
- nfs_inc_stats(data->inode, NFSIOS_SHORTREAD);
- /* Has the server at least made some progress? */
- if (resp->count != 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;
- }
- task->tk_status = -EIO;
- }
- spin_lock(&data->inode->i_lock);
- NFS_I(data->inode)->cache_validity |= NFS_INO_INVALID_ATIME;
- spin_unlock(&data->inode->i_lock);
- return 0;
-}
-
-/*
* 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
@@ -626,9 +614,10 @@ int nfs_readpage(struct file *file, struct page *page)
goto out_error;
if (file == NULL) {
+ error = -EBADF;
ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
if (ctx == NULL)
- return -EBADF;
+ goto out_error;
} else
ctx = get_nfs_open_context((struct nfs_open_context *)
file->private_data);
@@ -663,7 +652,7 @@ readpage_async_filler(void *data, struct page *page)
unsigned int len;
nfs_wb_page(inode, page);
- len = nfs_page_length(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);