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-rw-r--r--fs/nfs/read.c140
1 files changed, 69 insertions, 71 deletions
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index 8b58bbf6e39e..e879ee6e1385 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -461,6 +461,55 @@ nfs_pagein_list(struct list_head *head, int rpages)
461} 461}
462 462
463/* 463/*
464 * This is the callback from RPC telling us whether a reply was
465 * received or some error occurred (timeout or socket shutdown).
466 */
467int nfs_readpage_result(struct rpc_task *task, struct nfs_read_data *data)
468{
469 int status;
470
471 dprintk("%s: %4d, (status %d)\n", __FUNCTION__, task->tk_pid,
472 task->tk_status);
473
474 status = NFS_PROTO(data->inode)->read_done(task, data);
475 if (status != 0)
476 return status;
477
478 nfs_add_stats(data->inode, NFSIOS_SERVERREADBYTES, data->res.count);
479
480 if (task->tk_status == -ESTALE) {
481 set_bit(NFS_INO_STALE, &NFS_FLAGS(data->inode));
482 nfs_mark_for_revalidate(data->inode);
483 }
484 spin_lock(&data->inode->i_lock);
485 NFS_I(data->inode)->cache_validity |= NFS_INO_INVALID_ATIME;
486 spin_unlock(&data->inode->i_lock);
487 return 0;
488}
489
490static int nfs_readpage_retry(struct rpc_task *task, struct nfs_read_data *data)
491{
492 struct nfs_readargs *argp = &data->args;
493 struct nfs_readres *resp = &data->res;
494
495 if (resp->eof || resp->count == argp->count)
496 return 0;
497
498 /* This is a short read! */
499 nfs_inc_stats(data->inode, NFSIOS_SHORTREAD);
500 /* Has the server at least made some progress? */
501 if (resp->count == 0)
502 return 0;
503
504 /* Yes, so retry the read at the end of the data */
505 argp->offset += resp->count;
506 argp->pgbase += resp->count;
507 argp->count -= resp->count;
508 rpc_restart_call(task);
509 return -EAGAIN;
510}
511
512/*
464 * Handle a read reply that fills part of a page. 513 * Handle a read reply that fills part of a page.
465 */ 514 */
466static void nfs_readpage_result_partial(struct rpc_task *task, void *calldata) 515static void nfs_readpage_result_partial(struct rpc_task *task, void *calldata)
@@ -469,12 +518,16 @@ static void nfs_readpage_result_partial(struct rpc_task *task, void *calldata)
469 struct nfs_page *req = data->req; 518 struct nfs_page *req = data->req;
470 struct page *page = req->wb_page; 519 struct page *page = req->wb_page;
471 520
472 if (likely(task->tk_status >= 0))
473 nfs_readpage_truncate_uninitialised_page(data);
474 else
475 SetPageError(page);
476 if (nfs_readpage_result(task, data) != 0) 521 if (nfs_readpage_result(task, data) != 0)
477 return; 522 return;
523
524 if (likely(task->tk_status >= 0)) {
525 nfs_readpage_truncate_uninitialised_page(data);
526 if (nfs_readpage_retry(task, data) != 0)
527 return;
528 }
529 if (unlikely(task->tk_status < 0))
530 SetPageError(page);
478 if (atomic_dec_and_test(&req->wb_complete)) { 531 if (atomic_dec_and_test(&req->wb_complete)) {
479 if (!PageError(page)) 532 if (!PageError(page))
480 SetPageUptodate(page); 533 SetPageUptodate(page);
@@ -502,25 +555,13 @@ static void nfs_readpage_set_pages_uptodate(struct nfs_read_data *data)
502 count += base; 555 count += base;
503 for (;count >= PAGE_CACHE_SIZE; count -= PAGE_CACHE_SIZE, pages++) 556 for (;count >= PAGE_CACHE_SIZE; count -= PAGE_CACHE_SIZE, pages++)
504 SetPageUptodate(*pages); 557 SetPageUptodate(*pages);
505 if (count != 0) 558 if (count == 0)
559 return;
560 /* Was this a short read? */
561 if (data->res.eof || data->res.count == data->args.count)
506 SetPageUptodate(*pages); 562 SetPageUptodate(*pages);
507} 563}
508 564
509static void nfs_readpage_set_pages_error(struct nfs_read_data *data)
510{
511 unsigned int count = data->args.count;
512 unsigned int base = data->args.pgbase;
513 struct page **pages;
514
515 pages = &data->args.pages[base >> PAGE_CACHE_SHIFT];
516 base &= ~PAGE_CACHE_MASK;
517 count += base;
518 for (;count >= PAGE_CACHE_SIZE; count -= PAGE_CACHE_SIZE, pages++)
519 SetPageError(*pages);
520 if (count != 0)
521 SetPageError(*pages);
522}
523
524/* 565/*
525 * This is the callback from RPC telling us whether a reply was 566 * This is the callback from RPC telling us whether a reply was
526 * received or some error occurred (timeout or socket shutdown). 567 * received or some error occurred (timeout or socket shutdown).
@@ -529,19 +570,20 @@ static void nfs_readpage_result_full(struct rpc_task *task, void *calldata)
529{ 570{
530 struct nfs_read_data *data = calldata; 571 struct nfs_read_data *data = calldata;
531 572
573 if (nfs_readpage_result(task, data) != 0)
574 return;
532 /* 575 /*
533 * Note: nfs_readpage_result may change the values of 576 * Note: nfs_readpage_retry may change the values of
534 * data->args. In the multi-page case, we therefore need 577 * data->args. In the multi-page case, we therefore need
535 * to ensure that we call the next nfs_readpage_set_page_uptodate() 578 * to ensure that we call nfs_readpage_set_pages_uptodate()
536 * first in the multi-page case. 579 * first.
537 */ 580 */
538 if (likely(task->tk_status >= 0)) { 581 if (likely(task->tk_status >= 0)) {
539 nfs_readpage_truncate_uninitialised_page(data); 582 nfs_readpage_truncate_uninitialised_page(data);
540 nfs_readpage_set_pages_uptodate(data); 583 nfs_readpage_set_pages_uptodate(data);
541 } else 584 if (nfs_readpage_retry(task, data) != 0)
542 nfs_readpage_set_pages_error(data); 585 return;
543 if (nfs_readpage_result(task, data) != 0) 586 }
544 return;
545 while (!list_empty(&data->pages)) { 587 while (!list_empty(&data->pages)) {
546 struct nfs_page *req = nfs_list_entry(data->pages.next); 588 struct nfs_page *req = nfs_list_entry(data->pages.next);
547 589
@@ -556,50 +598,6 @@ static const struct rpc_call_ops nfs_read_full_ops = {
556}; 598};
557 599
558/* 600/*
559 * This is the callback from RPC telling us whether a reply was
560 * received or some error occurred (timeout or socket shutdown).
561 */
562int nfs_readpage_result(struct rpc_task *task, struct nfs_read_data *data)
563{
564 struct nfs_readargs *argp = &data->args;
565 struct nfs_readres *resp = &data->res;
566 int status;
567
568 dprintk("NFS: %4d nfs_readpage_result, (status %d)\n",
569 task->tk_pid, task->tk_status);
570
571 status = NFS_PROTO(data->inode)->read_done(task, data);
572 if (status != 0)
573 return status;
574
575 nfs_add_stats(data->inode, NFSIOS_SERVERREADBYTES, resp->count);
576
577 if (task->tk_status < 0) {
578 if (task->tk_status == -ESTALE) {
579 set_bit(NFS_INO_STALE, &NFS_FLAGS(data->inode));
580 nfs_mark_for_revalidate(data->inode);
581 }
582 } else if (resp->count < argp->count && !resp->eof) {
583 /* This is a short read! */
584 nfs_inc_stats(data->inode, NFSIOS_SHORTREAD);
585 /* Has the server at least made some progress? */
586 if (resp->count != 0) {
587 /* Yes, so retry the read at the end of the data */
588 argp->offset += resp->count;
589 argp->pgbase += resp->count;
590 argp->count -= resp->count;
591 rpc_restart_call(task);
592 return -EAGAIN;
593 }
594 task->tk_status = -EIO;
595 }
596 spin_lock(&data->inode->i_lock);
597 NFS_I(data->inode)->cache_validity |= NFS_INO_INVALID_ATIME;
598 spin_unlock(&data->inode->i_lock);
599 return 0;
600}
601
602/*
603 * Read a page over NFS. 601 * Read a page over NFS.
604 * We read the page synchronously in the following case: 602 * We read the page synchronously in the following case:
605 * - The error flag is set for this page. This happens only when a 603 * - The error flag is set for this page. This happens only when a