Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756359AbbLXCPa (ORCPT ); Wed, 23 Dec 2015 21:15:30 -0500 Received: from mail.kernel.org ([198.145.29.136]:56138 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752764AbbLXCP2 (ORCPT ); Wed, 23 Dec 2015 21:15:28 -0500 From: Jaegeuk Kim To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Cc: Jaegeuk Kim Subject: [PATCH 3/4] f2fs: avoid f2fs_lock_op in f2fs_write_begin Date: Wed, 23 Dec 2015 18:15:19 -0800 Message-Id: <1450923320-41113-3-git-send-email-jaegeuk@kernel.org> X-Mailer: git-send-email 2.5.4 (Apple Git-61) In-Reply-To: <1450923320-41113-1-git-send-email-jaegeuk@kernel.org> References: <1450923320-41113-1-git-send-email-jaegeuk@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2525 Lines: 96 If f2fs_write_begin is to update data, we can bypass calling f2fs_lock_op() in order to avoid the checkpoint latency in the write syscall. Signed-off-by: Jaegeuk Kim --- fs/f2fs/data.c | 43 ++++++++++++++++++++++++++++++++++--------- 1 file changed, 34 insertions(+), 9 deletions(-) diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 49092da..d53cf4f 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -1418,10 +1418,16 @@ static int prepare_write_begin(struct f2fs_sb_info *sbi, pgoff_t index = page->index; struct dnode_of_data dn; struct page *ipage; + bool locked = false; + struct extent_info ei; int err = 0; - f2fs_lock_op(sbi); - + if (f2fs_has_inline_data(inode) || + (pos & PAGE_CACHE_MASK) >= i_size_read(inode)) { + f2fs_lock_op(sbi); + locked = true; + } +restart: /* check inline_data */ ipage = get_node_page(sbi, inode->i_ino); if (IS_ERR(ipage)) { @@ -1436,22 +1442,41 @@ static int prepare_write_begin(struct f2fs_sb_info *sbi, read_inline_data(page, ipage); set_inode_flag(F2FS_I(inode), FI_DATA_EXIST); sync_inode_page(&dn); - goto done; } else { err = f2fs_convert_inline_page(&dn, page); if (err) - goto err_out; + goto out; + err = f2fs_get_block(&dn, index); + } + } else if (locked) { + err = f2fs_get_block(&dn, index); + } else { + if (f2fs_lookup_extent_cache(inode, index, &ei)) { + dn.data_blkaddr = ei.blk + index - ei.fofs; + } else { + bool restart = false; + + /* hole case */ + err = get_dnode_of_data(&dn, index, LOOKUP_NODE); + if (err || (!err && dn.data_blkaddr == NULL_ADDR)) + restart = true; + if (restart) { + f2fs_put_dnode(&dn); + f2fs_lock_op(sbi); + locked = true; + goto restart; + } } } - err = f2fs_get_block(&dn, index); -done: + /* convert_inline_page can make node_changed */ *blk_addr = dn.data_blkaddr; *node_changed = dn.node_changed; -err_out: +out: f2fs_put_dnode(&dn); unlock_out: - f2fs_unlock_op(sbi); + if (locked) + f2fs_unlock_op(sbi); return err; } @@ -1488,7 +1513,7 @@ repeat: *pagep = page; - err = prepare_write_begin(sbi, page, pos + len, + err = prepare_write_begin(sbi, page, pos, len, &blkaddr, &need_balance); if (err) goto fail; -- 2.5.4 (Apple Git-61) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/