*
* 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 <asm/system.h>
+#include "internal.h"
#include "iostat.h"
#define NFSDBG_FACILITY NFSDBG_PAGECACHE
static const struct rpc_call_ops nfs_read_partial_ops;
static const struct rpc_call_ops nfs_read_full_ops;
-static kmem_cache_t *nfs_rdata_cachep;
+static struct kmem_cache *nfs_rdata_cachep;
static mempool_t *nfs_rdata_mempool;
#define MIN_POOL_READ (32)
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
}
}
-/*
- * 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;
- struct nfs_read_data *rdata;
-
- rdata = nfs_readdata_alloc(count);
- if (!rdata)
- return -ENOMEM;
-
- 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:
- unlock_page(page);
- nfs_readdata_free(rdata);
- return result;
-}
-
static int nfs_readpage_async(struct nfs_open_context *ctx, struct inode *inode,
struct page *page)
{
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);
data->task.tk_cookie = (unsigned long)inode;
- dprintk("NFS: %4d initiated read call (req %s/%Ld, %u bytes @ offset %Lu)\n",
+ dprintk("NFS: %5u 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),
sigset_t oldset;
rpc_clnt_sigmask(clnt, &oldset);
- lock_kernel();
rpc_execute(&data->task);
- unlock_kernel();
rpc_clnt_sigunmask(clnt, &oldset);
}
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("NFS: %s: %5u, (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.
*/
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);
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).
{
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);
.rpc_release = nfs_readdata_release,
};
-/*
- * 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:
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);
- 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:
+ error = nfs_readpage_async(ctx, inode, page);
+
put_nfs_open_context(ctx);
return error;
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);
git.openpandora.org / pandora-kernel.git / blobdiff