From patchwork Tue Nov 9 01:50:41 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dave Chinner X-Patchwork-Id: 12609299 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2F554C4167B for ; Tue, 9 Nov 2021 01:51:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 130DE61105 for ; Tue, 9 Nov 2021 01:51:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237370AbhKIBxs (ORCPT ); Mon, 8 Nov 2021 20:53:48 -0500 Received: from mail108.syd.optusnet.com.au ([211.29.132.59]:40624 "EHLO mail108.syd.optusnet.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240143AbhKIBxq (ORCPT ); Mon, 8 Nov 2021 20:53:46 -0500 Received: from dread.disaster.area (pa49-195-103-97.pa.nsw.optusnet.com.au [49.195.103.97]) by mail108.syd.optusnet.com.au (Postfix) with ESMTPS id 19B901B8A82 for ; Tue, 9 Nov 2021 12:50:59 +1100 (AEDT) Received: from discord.disaster.area ([192.168.253.110]) by dread.disaster.area with esmtp (Exim 4.92.3) (envelope-from ) id 1mkGHq-006ZXr-3s for linux-xfs@vger.kernel.org; Tue, 09 Nov 2021 12:50:58 +1100 Received: from dave by discord.disaster.area with local (Exim 4.95) (envelope-from ) id 1mkGHq-006UcN-2W for linux-xfs@vger.kernel.org; Tue, 09 Nov 2021 12:50:58 +1100 From: Dave Chinner To: linux-xfs@vger.kernel.org Subject: [PATCH 02/16] xfs: only CIL pushes require a start record Date: Tue, 9 Nov 2021 12:50:41 +1100 Message-Id: <20211109015055.1547604-3-david@fromorbit.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20211109015055.1547604-1-david@fromorbit.com> References: <20211109015055.1547604-1-david@fromorbit.com> MIME-Version: 1.0 X-Optus-CM-Score: 0 X-Optus-CM-Analysis: v=2.4 cv=epq8cqlX c=1 sm=1 tr=0 ts=6189d403 a=fP9RlOTWD4uZJjPSFnn6Ew==:117 a=fP9RlOTWD4uZJjPSFnn6Ew==:17 a=vIxV3rELxO4A:10 a=20KFwNOVAAAA:8 a=VwQbUJbxAAAA:8 a=KPKL3CcRt_6iA-bUn9MA:9 a=AjGcO6oz07-iQ99wixmX:22 Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org From: Dave Chinner So move the one-off start record writing in xlog_write() out into the static header that the CIL push builds to write into the log initially. This simplifes the xlog_write() logic a lot. pahole on x86-64 confirms that the xlog_cil_trans_hdr is correctly 32 bit aligned and packed for copying the log op and transaction headers directly into the log as a single log region copy. struct xlog_cil_trans_hdr { struct xlog_op_header oph[2]; /* 0 24 */ struct xfs_trans_header thdr; /* 24 16 */ struct xfs_log_iovec lhdr[2]; /* 40 32 */ /* size: 72, cachelines: 2, members: 3 */ /* last cacheline: 8 bytes */ }; A wart is needed to handle the fact that length of the region the opheader points to doesn't include the opheader length. hence if we embed the opheader, we have to substract the opheader length from the length written into the opheader by the generic copying code. This will eventually go away when everything is converted to embedded opheaders. Signed-off-by: Dave Chinner Reviewed-by: Darrick J. Wong Reviewed-by: Christoph Hellwig --- fs/xfs/xfs_log.c | 90 ++++++++++++++++++++++---------------------- fs/xfs/xfs_log_cil.c | 44 ++++++++++++++++++---- 2 files changed, 81 insertions(+), 53 deletions(-) diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c index 89fec9a18c34..e2953ce470de 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -2235,9 +2235,9 @@ xlog_print_trans( } /* - * Calculate the potential space needed by the log vector. We may need a start - * record, and each region gets its own struct xlog_op_header and may need to be - * double word aligned. + * Calculate the potential space needed by the log vector. If this is a start + * transaction, the caller has already accounted for both opheaders in the start + * transaction, so we don't need to account for them here. */ static int xlog_write_calc_vec_length( @@ -2250,9 +2250,6 @@ xlog_write_calc_vec_length( int len = 0; int i; - if (optype & XLOG_START_TRANS) - headers++; - for (lv = log_vector; lv; lv = lv->lv_next) { /* we don't write ordered log vectors */ if (lv->lv_buf_len == XFS_LOG_VEC_ORDERED) @@ -2268,24 +2265,20 @@ xlog_write_calc_vec_length( } } + /* Don't account for regions with embedded ophdrs */ + if (optype && headers > 0) { + if (optype & XLOG_START_TRANS) { + ASSERT(headers >= 2); + headers -= 2; + } + } + ticket->t_res_num_ophdrs += headers; len += headers * sizeof(struct xlog_op_header); return len; } -static void -xlog_write_start_rec( - struct xlog_op_header *ophdr, - struct xlog_ticket *ticket) -{ - ophdr->oh_tid = cpu_to_be32(ticket->t_tid); - ophdr->oh_clientid = ticket->t_clientid; - ophdr->oh_len = 0; - ophdr->oh_flags = XLOG_START_TRANS; - ophdr->oh_res2 = 0; -} - static xlog_op_header_t * xlog_write_setup_ophdr( struct xlog *log, @@ -2481,9 +2474,11 @@ xlog_write( * If this is a commit or unmount transaction, we don't need a start * record to be written. We do, however, have to account for the * commit or unmount header that gets written. Hence we always have - * to account for an extra xlog_op_header here. + * to account for an extra xlog_op_header here for commit and unmount + * records. */ - ticket->t_curr_res -= sizeof(struct xlog_op_header); + if (optype & (XLOG_COMMIT_TRANS | XLOG_UNMOUNT_TRANS)) + ticket->t_curr_res -= sizeof(struct xlog_op_header); if (ticket->t_curr_res < 0) { xfs_alert_tag(log->l_mp, XFS_PTAG_LOGRES, "ctx ticket reservation ran out. Need to up reservation"); @@ -2524,7 +2519,7 @@ xlog_write( int copy_len; int copy_off; bool ordered = false; - bool wrote_start_rec = false; + bool added_ophdr = false; /* ordered log vectors have no regions to write */ if (lv->lv_buf_len == XFS_LOG_VEC_ORDERED) { @@ -2538,25 +2533,24 @@ xlog_write( ASSERT((unsigned long)ptr % sizeof(int32_t) == 0); /* - * Before we start formatting log vectors, we need to - * write a start record. Only do this for the first - * iclog we write to. + * The XLOG_START_TRANS has embedded ophdrs for the + * start record and transaction header. They will always + * be the first two regions in the lv chain. */ if (optype & XLOG_START_TRANS) { - xlog_write_start_rec(ptr, ticket); - xlog_write_adv_cnt(&ptr, &len, &log_offset, - sizeof(struct xlog_op_header)); - optype &= ~XLOG_START_TRANS; - wrote_start_rec = true; - } - - ophdr = xlog_write_setup_ophdr(log, ptr, ticket, optype); - if (!ophdr) - return -EIO; + ophdr = reg->i_addr; + if (index) + optype &= ~XLOG_START_TRANS; + } else { + ophdr = xlog_write_setup_ophdr(log, ptr, + ticket, optype); + if (!ophdr) + return -EIO; - xlog_write_adv_cnt(&ptr, &len, &log_offset, + xlog_write_adv_cnt(&ptr, &len, &log_offset, sizeof(struct xlog_op_header)); - + added_ophdr = true; + } len += xlog_write_setup_copy(ticket, ophdr, iclog->ic_size-log_offset, reg->i_len, @@ -2565,13 +2559,22 @@ xlog_write( &partial_copy_len); xlog_verify_dest_ptr(log, ptr); + + /* + * Wart: need to update length in embedded ophdr not + * to include it's own length. + */ + if (!added_ophdr) { + ophdr->oh_len = cpu_to_be32(copy_len - + sizeof(struct xlog_op_header)); + } /* * Copy region. * - * Unmount records just log an opheader, so can have - * empty payloads with no data region to copy. Hence we - * only copy the payload if the vector says it has data - * to copy. + * Commit and unmount records just log an opheader, so + * we can have empty payloads with no data region to + * copy. Hence we only copy the payload if the vector + * says it has data to copy. */ ASSERT(copy_len >= 0); if (copy_len > 0) { @@ -2579,12 +2582,9 @@ xlog_write( xlog_write_adv_cnt(&ptr, &len, &log_offset, copy_len); } - copy_len += sizeof(struct xlog_op_header); - record_cnt++; - if (wrote_start_rec) { + if (added_ophdr) copy_len += sizeof(struct xlog_op_header); - record_cnt++; - } + record_cnt++; data_cnt += contwr ? copy_len : 0; error = xlog_write_copy_finish(log, iclog, optype, diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c index 28f8104fbef1..560af08d81dc 100644 --- a/fs/xfs/xfs_log_cil.c +++ b/fs/xfs/xfs_log_cil.c @@ -835,14 +835,22 @@ xlog_cil_write_commit_record( } struct xlog_cil_trans_hdr { + struct xlog_op_header oph[2]; struct xfs_trans_header thdr; - struct xfs_log_iovec lhdr; + struct xfs_log_iovec lhdr[2]; }; /* * Build a checkpoint transaction header to begin the journal transaction. We * need to account for the space used by the transaction header here as it is * not accounted for in xlog_write(). + * + * This is the only place we write a transaction header, so we also build the + * log opheaders that indicate the start of a log transaction and wrap the + * transaction header. We keep the start record in it's own log vector rather + * than compacting them into a single region as this ends up making the logic + * in xlog_write() for handling empty opheaders for start, commit and unmount + * records much simpler. */ static void xlog_cil_build_trans_hdr( @@ -852,20 +860,40 @@ xlog_cil_build_trans_hdr( int num_iovecs) { struct xlog_ticket *tic = ctx->ticket; + uint32_t tid = cpu_to_be32(tic->t_tid); memset(hdr, 0, sizeof(*hdr)); + /* Log start record */ + hdr->oph[0].oh_tid = tid; + hdr->oph[0].oh_clientid = XFS_TRANSACTION; + hdr->oph[0].oh_flags = XLOG_START_TRANS; + + /* log iovec region pointer */ + hdr->lhdr[0].i_addr = &hdr->oph[0]; + hdr->lhdr[0].i_len = sizeof(struct xlog_op_header); + hdr->lhdr[0].i_type = XLOG_REG_TYPE_LRHEADER; + + /* log opheader */ + hdr->oph[1].oh_tid = tid; + hdr->oph[1].oh_clientid = XFS_TRANSACTION; + + /* transaction header */ hdr->thdr.th_magic = XFS_TRANS_HEADER_MAGIC; hdr->thdr.th_type = XFS_TRANS_CHECKPOINT; - hdr->thdr.th_tid = tic->t_tid; + hdr->thdr.th_tid = tid; hdr->thdr.th_num_items = num_iovecs; - hdr->lhdr.i_addr = &hdr->thdr; - hdr->lhdr.i_len = sizeof(xfs_trans_header_t); - hdr->lhdr.i_type = XLOG_REG_TYPE_TRANSHDR; - tic->t_curr_res -= hdr->lhdr.i_len + sizeof(struct xlog_op_header); - lvhdr->lv_niovecs = 1; - lvhdr->lv_iovecp = &hdr->lhdr; + /* log iovec region pointer */ + hdr->lhdr[1].i_addr = &hdr->oph[1]; + hdr->lhdr[1].i_len = sizeof(struct xlog_op_header) + + sizeof(struct xfs_trans_header); + hdr->lhdr[1].i_type = XLOG_REG_TYPE_TRANSHDR; + + tic->t_curr_res -= hdr->lhdr[0].i_len + hdr->lhdr[1].i_len; + + lvhdr->lv_niovecs = 2; + lvhdr->lv_iovecp = &hdr->lhdr[0]; lvhdr->lv_next = ctx->lv_chain; }