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>
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44dd151d5c
commit
de05a0cc2a
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@ -483,17 +483,19 @@ int nfs_readpage(struct file *file, struct page *page)
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*/
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*/
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error = nfs_wb_page(inode, page);
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error = nfs_wb_page(inode, page);
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if (error)
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if (error)
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goto out_error;
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goto out_unlock;
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if (PageUptodate(page))
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goto out_unlock;
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error = -ESTALE;
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error = -ESTALE;
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if (NFS_STALE(inode))
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if (NFS_STALE(inode))
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goto out_error;
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goto out_unlock;
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if (file == NULL) {
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if (file == NULL) {
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error = -EBADF;
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error = -EBADF;
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ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
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ctx = nfs_find_open_context(inode, NULL, FMODE_READ);
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if (ctx == NULL)
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if (ctx == NULL)
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goto out_error;
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goto out_unlock;
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} else
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} else
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ctx = get_nfs_open_context((struct nfs_open_context *)
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ctx = get_nfs_open_context((struct nfs_open_context *)
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file->private_data);
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file->private_data);
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@ -502,8 +504,7 @@ int nfs_readpage(struct file *file, struct page *page)
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put_nfs_open_context(ctx);
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put_nfs_open_context(ctx);
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return error;
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return error;
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out_unlock:
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out_error:
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unlock_page(page);
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unlock_page(page);
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return error;
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return error;
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}
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}
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@ -520,21 +521,32 @@ readpage_async_filler(void *data, struct page *page)
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struct inode *inode = page->mapping->host;
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struct inode *inode = page->mapping->host;
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struct nfs_page *new;
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struct nfs_page *new;
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unsigned int len;
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unsigned int len;
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int error;
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error = nfs_wb_page(inode, page);
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if (error)
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goto out_unlock;
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if (PageUptodate(page))
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goto out_unlock;
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nfs_wb_page(inode, page);
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len = nfs_page_length(page);
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len = nfs_page_length(page);
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if (len == 0)
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if (len == 0)
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return nfs_return_empty_page(page);
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return nfs_return_empty_page(page);
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new = nfs_create_request(desc->ctx, inode, page, 0, len);
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new = nfs_create_request(desc->ctx, inode, page, 0, len);
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if (IS_ERR(new)) {
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if (IS_ERR(new))
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SetPageError(page);
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goto out_error;
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unlock_page(page);
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return PTR_ERR(new);
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}
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if (len < PAGE_CACHE_SIZE)
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if (len < PAGE_CACHE_SIZE)
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zero_user_page(page, len, PAGE_CACHE_SIZE - len, KM_USER0);
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zero_user_page(page, len, PAGE_CACHE_SIZE - len, KM_USER0);
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nfs_pageio_add_request(desc->pgio, new);
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nfs_pageio_add_request(desc->pgio, new);
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return 0;
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return 0;
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out_error:
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error = PTR_ERR(new);
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SetPageError(page);
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out_unlock:
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unlock_page(page);
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return error;
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}
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}
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int nfs_readpages(struct file *filp, struct address_space *mapping,
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int nfs_readpages(struct file *filp, struct address_space *mapping,
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