From patchwork Fri Aug 21 07:39:52 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Omar Sandoval X-Patchwork-Id: 11728471 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id CA43B1575 for ; Fri, 21 Aug 2020 07:40:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A9F232087D for ; Fri, 21 Aug 2020 07:40:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=osandov-com.20150623.gappssmtp.com header.i=@osandov-com.20150623.gappssmtp.com header.b="yF3ZUILB" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728341AbgHUHkj (ORCPT ); Fri, 21 Aug 2020 03:40:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37200 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727902AbgHUHkT (ORCPT ); Fri, 21 Aug 2020 03:40:19 -0400 Received: from mail-pg1-x543.google.com (mail-pg1-x543.google.com [IPv6:2607:f8b0:4864:20::543]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 98220C061387 for ; Fri, 21 Aug 2020 00:40:19 -0700 (PDT) Received: by mail-pg1-x543.google.com with SMTP id 189so599926pgg.13 for ; Fri, 21 Aug 2020 00:40:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=osandov-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=rV0Iw2CCSZHG6p1G4uFOZPtC+8d3NmwhtMPWnU59b4o=; b=yF3ZUILBJ6pRuJOTEVflPp/vEYfpVErHnkY9F4KHaPMN2rchhmZ4blW6ivIKX/t5kk Bc4jBnsEvq0Al4xyHfDG4KcvMwGdOqguFCG/BabKcZLu4fgFmeNlh3/vqHK4mqim4N5n wPoJpKwrMsQiiES8kp/0YZWkWxUeXm2Ar0tWDe/Zh3t62KJ9z/HdxmIdwHaUyck3BnKe UanAV49SOd2H+bW+EVEGqhpOvnCElcpIIzhcoLeKJBy4juaDdohUU1H1H4WUZ85079tf IGbrthiM0giWDVo/bWkwdWKRRtp1blu0V3440gZZ0AugisuBgt+CCGN94WASxhEDo/Nr 0Jvw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=rV0Iw2CCSZHG6p1G4uFOZPtC+8d3NmwhtMPWnU59b4o=; b=W5j5DtTMSH4Oq4/3XqiEd8e4Q5uxQGKW8jRdpwBiuMKrnMsURHThut8n7/TlUMj1CL tsV2uaH1l0PNcQnH8gqK0VICyyIOyDJy4e5B8Rm+Irzh1LUKsYkCvCGM88G+dyucxARe LP7A/Z2hgj9mdBgr6/kTV21JrIR/9pbPBlJaV8whZFV8msG9vcwK2DLZn9hwwS2S8owh tNu7f3bzt/Ewh76Z77F9JrLCC+pZyTbrxE0K12ennJxyHjhJ11baJte5el8yX12K8x8W yryB/Bkjvdzf89+pfOr7MXPsiyWrU49iE2peMd4ohCMW7ySAG5W++J3T5Z1KCXBRfqBE 4AUA== X-Gm-Message-State: AOAM530kH0RBGLGCARxOL/k/SYiPSJLNItg75XMFtq8WgJZbBHcAGRIM k9NWBFheWjyh1YWNZ16xIpUMUl1KSeMbVw== X-Google-Smtp-Source: ABdhPJx5BYSVv2feYz5UTuKAlmjkIsTLVPVDIM/X9wiNoLdnQYy0W7Vg3XqVJIGd7kHmLA05UdiIAQ== X-Received: by 2002:a62:9246:: with SMTP id o67mr1416722pfd.249.1597995619020; Fri, 21 Aug 2020 00:40:19 -0700 (PDT) Received: from exodia.tfbnw.net ([2620:10d:c090:400::5:f2a4]) by smtp.gmail.com with ESMTPSA id jb1sm1080875pjb.9.2020.08.21.00.40.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 21 Aug 2020 00:40:17 -0700 (PDT) From: Omar Sandoval To: linux-btrfs@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Subject: [PATCH 2/9] btrfs: send: avoid copying file data Date: Fri, 21 Aug 2020 00:39:52 -0700 Message-Id: X-Mailer: git-send-email 2.28.0 In-Reply-To: References: MIME-Version: 1.0 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org From: Omar Sandoval send_write() currently copies from the page cache to sctx->read_buf, and then from sctx->read_buf to sctx->send_buf. Similarly, send_hole() zeroes sctx->read_buf and then copies from sctx->read_buf to sctx->send_buf. However, if we write the TLV header manually, we can copy to sctx->send_buf directly and get rid of sctx->read_buf. Signed-off-by: Omar Sandoval Reviewed-by: Filipe Manana Reviewed-by: Josef Bacik --- fs/btrfs/send.c | 65 +++++++++++++++++++++++++++++-------------------- fs/btrfs/send.h | 1 - 2 files changed, 39 insertions(+), 27 deletions(-) diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c index 8af5e867e4ca..e70f5ceb3261 100644 --- a/fs/btrfs/send.c +++ b/fs/btrfs/send.c @@ -122,8 +122,6 @@ struct send_ctx { struct file_ra_state ra; - char *read_buf; - /* * We process inodes by their increasing order, so if before an * incremental send we reverse the parent/child relationship of @@ -4794,7 +4792,25 @@ static int process_all_new_xattrs(struct send_ctx *sctx) return ret; } -static int fill_read_buf(struct send_ctx *sctx, u64 offset, u32 len) +static u64 max_send_read_size(struct send_ctx *sctx) +{ + return sctx->send_max_size - SZ_16K; +} + +static int put_data_header(struct send_ctx *sctx, u32 len) +{ + struct btrfs_tlv_header *hdr; + + if (sctx->send_max_size - sctx->send_size < sizeof(*hdr) + len) + return -EOVERFLOW; + hdr = (struct btrfs_tlv_header *)(sctx->send_buf + sctx->send_size); + hdr->tlv_type = cpu_to_le16(BTRFS_SEND_A_DATA); + hdr->tlv_len = cpu_to_le16(len); + sctx->send_size += sizeof(*hdr); + return 0; +} + +static int put_file_data(struct send_ctx *sctx, u64 offset, u32 len) { struct btrfs_root *root = sctx->send_root; struct btrfs_fs_info *fs_info = root->fs_info; @@ -4804,8 +4820,11 @@ static int fill_read_buf(struct send_ctx *sctx, u64 offset, u32 len) pgoff_t index = offset >> PAGE_SHIFT; pgoff_t last_index; unsigned pg_offset = offset_in_page(offset); - int ret = 0; - size_t read = 0; + int ret; + + ret = put_data_header(sctx, len); + if (ret) + return ret; inode = btrfs_iget(fs_info->sb, sctx->cur_ino, root); if (IS_ERR(inode)) @@ -4851,14 +4870,15 @@ static int fill_read_buf(struct send_ctx *sctx, u64 offset, u32 len) } addr = kmap(page); - memcpy(sctx->read_buf + read, addr + pg_offset, cur_len); + memcpy(sctx->send_buf + sctx->send_size, addr + pg_offset, + cur_len); kunmap(page); unlock_page(page); put_page(page); index++; pg_offset = 0; len -= cur_len; - read += cur_len; + sctx->send_size += cur_len; } iput(inode); return ret; @@ -4880,10 +4900,6 @@ static int send_write(struct send_ctx *sctx, u64 offset, u32 len) btrfs_debug(fs_info, "send_write offset=%llu, len=%d", offset, len); - ret = fill_read_buf(sctx, offset, len); - if (ret < 0) - goto out; - ret = begin_cmd(sctx, BTRFS_SEND_C_WRITE); if (ret < 0) goto out; @@ -4894,7 +4910,9 @@ static int send_write(struct send_ctx *sctx, u64 offset, u32 len) TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p); TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset); - TLV_PUT(sctx, BTRFS_SEND_A_DATA, sctx->read_buf, len); + ret = put_file_data(sctx, offset, len); + if (ret < 0) + goto out; ret = send_cmd(sctx); @@ -5013,8 +5031,8 @@ static int send_update_extent(struct send_ctx *sctx, static int send_hole(struct send_ctx *sctx, u64 end) { struct fs_path *p = NULL; + u64 read_size = max_send_read_size(sctx); u64 offset = sctx->cur_inode_last_extent; - u64 len; int ret = 0; /* @@ -5041,16 +5059,19 @@ static int send_hole(struct send_ctx *sctx, u64 end) ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p); if (ret < 0) goto tlv_put_failure; - memset(sctx->read_buf, 0, BTRFS_SEND_READ_SIZE); while (offset < end) { - len = min_t(u64, end - offset, BTRFS_SEND_READ_SIZE); + u64 len = min(end - offset, read_size); ret = begin_cmd(sctx, BTRFS_SEND_C_WRITE); if (ret < 0) break; TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p); TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset); - TLV_PUT(sctx, BTRFS_SEND_A_DATA, sctx->read_buf, len); + ret = put_data_header(sctx, len); + if (ret < 0) + break; + memset(sctx->send_buf + sctx->send_size, 0, len); + sctx->send_size += len; ret = send_cmd(sctx); if (ret < 0) break; @@ -5066,17 +5087,16 @@ static int send_extent_data(struct send_ctx *sctx, const u64 offset, const u64 len) { + u64 read_size = max_send_read_size(sctx); u64 sent = 0; if (sctx->flags & BTRFS_SEND_FLAG_NO_FILE_DATA) return send_update_extent(sctx, offset, len); while (sent < len) { - u64 size = len - sent; + u64 size = min(len - sent, read_size); int ret; - if (size > BTRFS_SEND_READ_SIZE) - size = BTRFS_SEND_READ_SIZE; ret = send_write(sctx, offset + sent, size); if (ret < 0) return ret; @@ -7145,12 +7165,6 @@ long btrfs_ioctl_send(struct file *mnt_file, struct btrfs_ioctl_send_args *arg) goto out; } - sctx->read_buf = kvmalloc(BTRFS_SEND_READ_SIZE, GFP_KERNEL); - if (!sctx->read_buf) { - ret = -ENOMEM; - goto out; - } - sctx->pending_dir_moves = RB_ROOT; sctx->waiting_dir_moves = RB_ROOT; sctx->orphan_dirs = RB_ROOT; @@ -7354,7 +7368,6 @@ long btrfs_ioctl_send(struct file *mnt_file, struct btrfs_ioctl_send_args *arg) kvfree(sctx->clone_roots); kvfree(sctx->send_buf); - kvfree(sctx->read_buf); name_cache_free(sctx); diff --git a/fs/btrfs/send.h b/fs/btrfs/send.h index ead397f7034f..de91488b7cd0 100644 --- a/fs/btrfs/send.h +++ b/fs/btrfs/send.h @@ -13,7 +13,6 @@ #define BTRFS_SEND_STREAM_VERSION 1 #define BTRFS_SEND_BUF_SIZE SZ_64K -#define BTRFS_SEND_READ_SIZE (48 * SZ_1K) enum btrfs_tlv_type { BTRFS_TLV_U8,