From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0ACD4C43441 for ; Mon, 26 Nov 2018 09:44:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C0A1A20850 for ; Mon, 26 Nov 2018 09:44:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C0A1A20850 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-btrfs-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726274AbeKZUiH (ORCPT ); Mon, 26 Nov 2018 15:38:07 -0500 Received: from mx2.suse.de ([195.135.220.15]:46564 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726184AbeKZUiH (ORCPT ); Mon, 26 Nov 2018 15:38:07 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 75CFFACA9; Mon, 26 Nov 2018 09:44:31 +0000 (UTC) Subject: Re: [PATCH 6/6] btrfs: fix truncate throttling To: Josef Bacik , linux-btrfs@vger.kernel.org, kernel-team@fb.com References: <20181121185912.24288-1-josef@toxicpanda.com> <20181121185912.24288-7-josef@toxicpanda.com> From: Nikolay Borisov Openpgp: preference=signencrypt Autocrypt: addr=nborisov@suse.com; prefer-encrypt=mutual; keydata= xsFNBFiKBz4BEADNHZmqwhuN6EAzXj9SpPpH/nSSP8YgfwoOqwrP+JR4pIqRK0AWWeWCSwmZ T7g+RbfPFlmQp+EwFWOtABXlKC54zgSf+uulGwx5JAUFVUIRBmnHOYi/lUiE0yhpnb1KCA7f u/W+DkwGerXqhhe9TvQoGwgCKNfzFPZoM+gZrm+kWv03QLUCr210n4cwaCPJ0Nr9Z3c582xc bCUVbsjt7BN0CFa2BByulrx5xD9sDAYIqfLCcZetAqsTRGxM7LD0kh5WlKzOeAXj5r8DOrU2 GdZS33uKZI/kZJZVytSmZpswDsKhnGzRN1BANGP8sC+WD4eRXajOmNh2HL4P+meO1TlM3GLl EQd2shHFY0qjEo7wxKZI1RyZZ5AgJnSmehrPCyuIyVY210CbMaIKHUIsTqRgY5GaNME24w7h TyyVCy2qAM8fLJ4Vw5bycM/u5xfWm7gyTb9V1TkZ3o1MTrEsrcqFiRrBY94Rs0oQkZvunqia c+NprYSaOG1Cta14o94eMH271Kka/reEwSZkC7T+o9hZ4zi2CcLcY0DXj0qdId7vUKSJjEep c++s8ncFekh1MPhkOgNj8pk17OAESanmDwksmzh1j12lgA5lTFPrJeRNu6/isC2zyZhTwMWs k3LkcTa8ZXxh0RfWAqgx/ogKPk4ZxOXQEZetkEyTFghbRH2BIwARAQABzSJOaWtvbGF5IEJv cmlzb3YgPG5ib3Jpc292QHN1c2UuZGU+wsF4BBMBAgAiBQJYijkSAhsDBgsJCAcDAgYVCAIJ CgsEFgIDAQIeAQIXgAAKCRBxvoJG5T8oV/B6D/9a8EcRPdHg8uLEPywuJR8URwXzkofT5bZE IfGF0Z+Lt2ADe+nLOXrwKsamhweUFAvwEUxxnndovRLPOpWerTOAl47lxad08080jXnGfYFS Dc+ew7C3SFI4tFFHln8Y22Q9075saZ2yQS1ywJy+TFPADIprAZXnPbbbNbGtJLoq0LTiESnD w/SUC6sfikYwGRS94Dc9qO4nWyEvBK3Ql8NkoY0Sjky3B0vL572Gq0ytILDDGYuZVo4alUs8 LeXS5ukoZIw1QYXVstDJQnYjFxYgoQ5uGVi4t7FsFM/6ykYDzbIPNOx49Rbh9W4uKsLVhTzG BDTzdvX4ARl9La2kCQIjjWRg+XGuBM5rxT/NaTS78PXjhqWNYlGc5OhO0l8e5DIS2tXwYMDY LuHYNkkpMFksBslldvNttSNei7xr5VwjVqW4vASk2Aak5AleXZS+xIq2FADPS/XSgIaepyTV tkfnyreep1pk09cjfXY4A7qpEFwazCRZg9LLvYVc2M2eFQHDMtXsH59nOMstXx2OtNMcx5p8 0a5FHXE/HoXz3p9bD0uIUq6p04VYOHsMasHqHPbsMAq9V2OCytJQPWwe46bBjYZCOwG0+x58 fBFreP/NiJNeTQPOa6FoxLOLXMuVtpbcXIqKQDoEte9aMpoj9L24f60G4q+pL/54ql2VRscK d87BTQRYigc+ARAAyJSq9EFk28++SLfg791xOh28tLI6Yr8wwEOvM3wKeTfTZd+caVb9gBBy wxYhIopKlK1zq2YP7ZjTP1aPJGoWvcQZ8fVFdK/1nW+Z8/NTjaOx1mfrrtTGtFxVBdSCgqBB jHTnlDYV1R5plJqK+ggEP1a0mr/rpQ9dFGvgf/5jkVpRnH6BY0aYFPprRL8ZCcdv2DeeicOO YMobD5g7g/poQzHLLeT0+y1qiLIFefNABLN06Lf0GBZC5l8hCM3Rpb4ObyQ4B9PmL/KTn2FV Xq/c0scGMdXD2QeWLePC+yLMhf1fZby1vVJ59pXGq+o7XXfYA7xX0JsTUNxVPx/MgK8aLjYW hX+TRA4bCr4uYt/S3ThDRywSX6Hr1lyp4FJBwgyb8iv42it8KvoeOsHqVbuCIGRCXqGGiaeX Wa0M/oxN1vJjMSIEVzBAPi16tztL/wQtFHJtZAdCnuzFAz8ue6GzvsyBj97pzkBVacwp3/Mw qbiu7sDz7yB0d7J2tFBJYNpVt/Lce6nQhrvon0VqiWeMHxgtQ4k92Eja9u80JDaKnHDdjdwq FUikZirB28UiLPQV6PvCckgIiukmz/5ctAfKpyYRGfez+JbAGl6iCvHYt/wAZ7Oqe/3Cirs5 KhaXBcMmJR1qo8QH8eYZ+qhFE3bSPH446+5oEw8A9v5oonKV7zMAEQEAAcLBXwQYAQIACQUC WIoHPgIbDAAKCRBxvoJG5T8oV1pyD/4zdXdOL0lhkSIjJWGqz7Idvo0wjVHSSQCbOwZDWNTN JBTP0BUxHpPu/Z8gRNNP9/k6i63T4eL1xjy4umTwJaej1X15H8Hsh+zakADyWHadbjcUXCkg OJK4NsfqhMuaIYIHbToi9K5pAKnV953xTrK6oYVyd/Rmkmb+wgsbYQJ0Ur1Ficwhp6qU1CaJ mJwFjaWaVgUERoxcejL4ruds66LM9Z1Qqgoer62ZneID6ovmzpCWbi2sfbz98+kW46aA/w8r 7sulgs1KXWhBSv5aWqKU8C4twKjlV2XsztUUsyrjHFj91j31pnHRklBgXHTD/pSRsN0UvM26 lPs0g3ryVlG5wiZ9+JbI3sKMfbdfdOeLxtL25ujs443rw1s/PVghphoeadVAKMPINeRCgoJH zZV/2Z/myWPRWWl/79amy/9MfxffZqO9rfugRBORY0ywPHLDdo9Kmzoxoxp9w3uTrTLZaT9M KIuxEcV8wcVjr+Wr9zRl06waOCkgrQbTPp631hToxo+4rA1jiQF2M80HAet65ytBVR2pFGZF zGYYLqiG+mpUZ+FPjxk9kpkRYz61mTLSY7tuFljExfJWMGfgSg1OxfLV631jV1TcdUnx+h3l Sqs2vMhAVt14zT8mpIuu2VNxcontxgVr1kzYA/tQg32fVRbGr449j1gw57BV9i0vww== Message-ID: Date: Mon, 26 Nov 2018 11:44:30 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.2.1 MIME-Version: 1.0 In-Reply-To: <20181121185912.24288-7-josef@toxicpanda.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On 21.11.18 г. 20:59 ч., Josef Bacik wrote: > We have a bunch of magic to make sure we're throttling delayed refs when > truncating a file. Now that we have a delayed refs rsv and a mechanism > for refilling that reserve simply use that instead of all of this magic. > > Signed-off-by: Josef Bacik Reviewed-by: Nikolay Borisov > --- > fs/btrfs/inode.c | 79 ++++++++++++-------------------------------------------- > 1 file changed, 17 insertions(+), 62 deletions(-) > > diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c > index 8532a2eb56d1..cae30f6c095f 100644 > --- a/fs/btrfs/inode.c > +++ b/fs/btrfs/inode.c > @@ -4437,31 +4437,6 @@ static int btrfs_rmdir(struct inode *dir, struct dentry *dentry) > return err; > } > > -static int truncate_space_check(struct btrfs_trans_handle *trans, > - struct btrfs_root *root, > - u64 bytes_deleted) > -{ > - struct btrfs_fs_info *fs_info = root->fs_info; > - int ret; > - > - /* > - * This is only used to apply pressure to the enospc system, we don't > - * intend to use this reservation at all. > - */ > - bytes_deleted = btrfs_csum_bytes_to_leaves(fs_info, bytes_deleted); > - bytes_deleted *= fs_info->nodesize; > - ret = btrfs_block_rsv_add(root, &fs_info->trans_block_rsv, > - bytes_deleted, BTRFS_RESERVE_NO_FLUSH); > - if (!ret) { > - trace_btrfs_space_reservation(fs_info, "transaction", > - trans->transid, > - bytes_deleted, 1); > - trans->bytes_reserved += bytes_deleted; > - } > - return ret; > - > -} > - > /* > * Return this if we need to call truncate_block for the last bit of the > * truncate. > @@ -4506,7 +4481,6 @@ int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans, > u64 bytes_deleted = 0; > bool be_nice = false; > bool should_throttle = false; > - bool should_end = false; > > BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY); > > @@ -4719,15 +4693,7 @@ int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans, > btrfs_abort_transaction(trans, ret); > break; > } > - if (btrfs_should_throttle_delayed_refs(trans)) > - btrfs_async_run_delayed_refs(fs_info, > - trans->delayed_ref_updates * 2, > - trans->transid, 0); > if (be_nice) { > - if (truncate_space_check(trans, root, > - extent_num_bytes)) { > - should_end = true; > - } > if (btrfs_should_throttle_delayed_refs(trans)) > should_throttle = true; > } > @@ -4738,7 +4704,7 @@ int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans, > > if (path->slots[0] == 0 || > path->slots[0] != pending_del_slot || > - should_throttle || should_end) { > + should_throttle) { > if (pending_del_nr) { > ret = btrfs_del_items(trans, root, path, > pending_del_slot, > @@ -4750,23 +4716,24 @@ int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans, > pending_del_nr = 0; > } > btrfs_release_path(path); > - if (should_throttle) { > - unsigned long updates = trans->delayed_ref_updates; > - if (updates) { > - trans->delayed_ref_updates = 0; > - ret = btrfs_run_delayed_refs(trans, > - updates * 2); > - if (ret) > - break; > - } > - } > + > /* > - * if we failed to refill our space rsv, bail out > - * and let the transaction restart > + * We can generate a lot of delayed refs, so we need to > + * throttle every once and a while and make sure we're > + * adding enough space to keep up with the work we are > + * generating. Since we hold a transaction here we > + * can't flush, and we don't want to FLUSH_LIMIT because > + * we could have generated too many delayed refs to > + * actually allocate, so just bail if we're short and > + * let the normal reservation dance happen higher up. > */ > - if (should_end) { > - ret = -EAGAIN; > - break; > + if (should_throttle) { > + ret = btrfs_throttle_delayed_refs(fs_info, > + BTRFS_RESERVE_NO_FLUSH); > + if (ret) { > + ret = -EAGAIN; > + break; > + } > } > goto search_again; > } else { > @@ -4792,18 +4759,6 @@ int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans, > } > > btrfs_free_path(path); > - > - if (be_nice && bytes_deleted > SZ_32M && (ret >= 0 || ret == -EAGAIN)) { > - unsigned long updates = trans->delayed_ref_updates; > - int err; > - > - if (updates) { > - trans->delayed_ref_updates = 0; > - err = btrfs_run_delayed_refs(trans, updates * 2); > - if (err) > - ret = err; > - } > - } > return ret; > } > >