aboutsummaryrefslogtreecommitdiffstats
path: root/fs/nfs/read.c
diff options
context:
space:
mode:
authorTrond Myklebust <Trond.Myklebust@netapp.com>2007-05-20 13:05:05 -0400
committerTrond Myklebust <Trond.Myklebust@netapp.com>2007-07-10 23:40:23 -0400
commitde05a0cc2a2ae16eb8d8dbf88fe728ace45beb9a (patch)
tree363a6afc01a935d9e34b3559235687f8fec4d512 /fs/nfs/read.c
parent44dd151d5c21234cc534c47d7382f5c28c3143cd (diff)
NFS: Minor read optimisation...
Since PG_uptodate may now end up getting set during the call to nfs_wb_page(), we can avoid putting a read request on the wire in those situations. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Diffstat (limited to 'fs/nfs/read.c')
-rw-r--r--fs/nfs/read.c34
1 files changed, 23 insertions, 11 deletions
diff --git a/fs/nfs/read.c b/fs/nfs/read.c
index 7bd7cb95c034..c07d0d10d9ed 100644
--- a/fs/nfs/read.c
+++ b/fs/nfs/read.c
@@ -483,17 +483,19 @@ int nfs_readpage(struct file *file, struct page *page)
483 */ 483 */
484 error = nfs_wb_page(inode, page); 484 error = nfs_wb_page(inode, page);
485 if (error) 485 if (error)
486 goto out_error; 486 goto out_unlock;
487 if (PageUptodate(page))
488 goto out_unlock;
487 489
488 error = -ESTALE; 490 error = -ESTALE;
489 if (NFS_STALE(inode)) 491 if (NFS_STALE(inode))
490 goto out_error; 492 goto out_unlock;
491 493
492 if (file == NULL) { 494 if (file == NULL) {
493 error = -EBADF; 495 error = -EBADF;
494 ctx = nfs_find_open_context(inode, NULL, FMODE_READ); 496 ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
495 if (ctx == NULL) 497 if (ctx == NULL)
496 goto out_error; 498 goto out_unlock;
497 } else 499 } else
498 ctx = get_nfs_open_context((struct nfs_open_context *) 500 ctx = get_nfs_open_context((struct nfs_open_context *)
499 file->private_data); 501 file->private_data);
@@ -502,8 +504,7 @@ int nfs_readpage(struct file *file, struct page *page)
502 504
503 put_nfs_open_context(ctx); 505 put_nfs_open_context(ctx);
504 return error; 506 return error;
505 507out_unlock:
506out_error:
507 unlock_page(page); 508 unlock_page(page);
508 return error; 509 return error;
509} 510}
@@ -520,21 +521,32 @@ readpage_async_filler(void *data, struct page *page)
520 struct inode *inode = page->mapping->host; 521 struct inode *inode = page->mapping->host;
521 struct nfs_page *new; 522 struct nfs_page *new;
522 unsigned int len; 523 unsigned int len;
524 int error;
525
526 error = nfs_wb_page(inode, page);
527 if (error)
528 goto out_unlock;
529 if (PageUptodate(page))
530 goto out_unlock;
523 531
524 nfs_wb_page(inode, page);
525 len = nfs_page_length(page); 532 len = nfs_page_length(page);
526 if (len == 0) 533 if (len == 0)
527 return nfs_return_empty_page(page); 534 return nfs_return_empty_page(page);
535
528 new = nfs_create_request(desc->ctx, inode, page, 0, len); 536 new = nfs_create_request(desc->ctx, inode, page, 0, len);
529 if (IS_ERR(new)) { 537 if (IS_ERR(new))
530 SetPageError(page); 538 goto out_error;
531 unlock_page(page); 539
532 return PTR_ERR(new);
533 }
534 if (len < PAGE_CACHE_SIZE) 540 if (len < PAGE_CACHE_SIZE)
535 zero_user_page(page, len, PAGE_CACHE_SIZE - len, KM_USER0); 541 zero_user_page(page, len, PAGE_CACHE_SIZE - len, KM_USER0);
536 nfs_pageio_add_request(desc->pgio, new); 542 nfs_pageio_add_request(desc->pgio, new);
537 return 0; 543 return 0;
544out_error:
545 error = PTR_ERR(new);
546 SetPageError(page);
547out_unlock:
548 unlock_page(page);
549 return error;
538} 550}
539 551
540int nfs_readpages(struct file *filp, struct address_space *mapping, 552int nfs_readpages(struct file *filp, struct address_space *mapping,