From nobody Wed Feb 15 21:33:14 2023 X-Original-To: dev-commits-src-all@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4PHBBy3CVMz3rMf1; Wed, 15 Feb 2023 21:33:14 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4PHBBy2kYLz3LjT; Wed, 15 Feb 2023 21:33:14 +0000 (UTC) (envelope-from git@FreeBSD.org) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1676496794; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=7SIOT1vHEXkBjnhdvFssQGMMEuAV7YlOZXu+wwvOP+A=; b=ItsT8Imn40Bi8HuAcwiEDR3l1WonpWd7zPfgAUvFDwBb5q+0Bn1E8g5oqrVgZ070wOl381 EH3vB4FHmqnDglAJB8QFjKbUEhRgX8kuA1v5Ssy6GIXf/ro1acFgpDiUBgZz1n/1SgGQVC gKwVdN3ZlkLfw08p8qY6RDvq1UXFqasvD1dvm98iD1xPloM46o6ZIj/KMK4Cp8ePKJzCON ksar7LX5vSl+L1Vrz8Q9SswjliBnWwiZmoIztjzdtc2Vgej3lcBVTKJkvhOufOd5YkscV1 nYwiApB2A1PRDS4iACQslJp16YkxY+eJyu7c7JLsOZbEc9EpB2omTjUky1Ff2Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1676496794; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=7SIOT1vHEXkBjnhdvFssQGMMEuAV7YlOZXu+wwvOP+A=; b=GzP0CmaBwZeD4QC64YmaUfCwg5zsq0ZNiNq6gj0E40T5yY/xWKFnB3gp59YdNx3GGZuqm1 8WcKXcqtrn1EmsenPQMFal8lTYhyLFL7ddJSJ3LiF6R3lrKWyAIAfgbRZLcdIFKt8ugA2g XKj7kxhe6wTOCoNG+e1TBgoYbDvThXY6OqePupo4MR1/r149kCz2/kvqwuwvGKQ7WGM4nl yrtDXGrKF3yresktzqRZ6Pn1nSMa3iv/IKneTNn0ycjrvFISXkAUoWyhQgDIOxecQvBnJ7 jA1vqxsKuSFbsLFHF3mdvkogwyro961+AZo7WgjckeV/QTlteE1Agg2I6KJXmw== ARC-Authentication-Results: i=1; mx1.freebsd.org; none ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1676496794; a=rsa-sha256; cv=none; b=L9dmD6mgcS71muMuJZL2hbNgXdXPnWjWPW5IoFVxuZ4h9hAZ6xFw+jfWqtuPoGjHtoEq+R /BKC4LvDm+tcLeEkWxVPz19cwEm+g74WhREXstGZBLVuf3J5/HULL8BzMwCD8Uo0bev8Nu 9y6VOuGak9d5B6gDl5MlHg3iiGYqa0Z5+HxvPtoWTRPLP5f4Ae3L8NNMCI62eKWTQBzJTx EIB9huRVARIRbG5CZIuFgLba3xnwyYNoEFUdd4U7wKLj7ZplZ9p14729nMLbebJOpkV9EQ gJhwt6YliGfq7GNrpbACD/spmFdapl1Zoy9ppXuBV83smb4OLlQXutdenSaDQA== Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 4PHBBy1n4MzfgF; Wed, 15 Feb 2023 21:33:14 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.16.1/8.16.1) with ESMTP id 31FLXErE021522; Wed, 15 Feb 2023 21:33:14 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 31FLXEep021521; Wed, 15 Feb 2023 21:33:14 GMT (envelope-from git) Date: Wed, 15 Feb 2023 21:33:14 GMT Message-Id: <202302152133.31FLXEep021521@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: John Baldwin Subject: git: 98844e99d40a - main - aio: Fix more synchronization issues in aio_biowakeup. List-Id: Commit messages for all branches of the src repository List-Archive: https://lists.freebsd.org/archives/dev-commits-src-all List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-dev-commits-src-all@freebsd.org X-BeenThere: dev-commits-src-all@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: jhb X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 98844e99d40a90ae89d84762e07150af3a8f89bd Auto-Submitted: auto-generated X-ThisMailContainsUnwantedMimeParts: N The branch main has been updated by jhb: URL: https://cgit.FreeBSD.org/src/commit/?id=98844e99d40a90ae89d84762e07150af3a8f89bd commit 98844e99d40a90ae89d84762e07150af3a8f89bd Author: John Baldwin AuthorDate: 2023-02-15 21:32:52 +0000 Commit: John Baldwin CommitDate: 2023-02-15 21:32:52 +0000 aio: Fix more synchronization issues in aio_biowakeup. - Use atomic_store to set job->error. atomic_set does an or operation, not assignment. - Use refcount_* to manage job->nbio. This ensures proper memory barriers are present so that the last bio won't see a possibly stale value of job->error. - Don't re-read job->error after reading it via atomic_load. Reported by: markj (1) Reviewed by: mjg, markj Differential Revision: https://reviews.freebsd.org/D38611 --- sys/kern/vfs_aio.c | 11 ++++++----- sys/sys/aio.h | 2 +- 2 files changed, 7 insertions(+), 6 deletions(-) diff --git a/sys/kern/vfs_aio.c b/sys/kern/vfs_aio.c index 9868b8770747..d32e6fea15ca 100644 --- a/sys/kern/vfs_aio.c +++ b/sys/kern/vfs_aio.c @@ -1281,7 +1281,7 @@ aio_qbio(struct proc *p, struct kaiocb *job) } bios = malloc(sizeof(struct bio *) * iovcnt, M_TEMP, M_WAITOK); - atomic_store_int(&job->nbio, iovcnt); + refcount_init(&job->nbio, iovcnt); for (i = 0; i < iovcnt; i++) { struct vm_page** pages; struct bio *bp; @@ -2489,15 +2489,16 @@ aio_biowakeup(struct bio *bp) * error of whichever failed bio completed last. */ if (flags & BIO_ERROR) - atomic_set_int(&job->error, bio_error); + atomic_store_int(&job->error, bio_error); if (opcode & LIO_WRITE) atomic_add_int(&job->outblock, nblks); else atomic_add_int(&job->inblock, nblks); - if (atomic_fetchadd_int(&job->nbio, -1) == 1) { - if (atomic_load_int(&job->error)) - aio_complete(job, -1, job->error); + if (refcount_release(&job->nbio)) { + bio_error = atomic_load_int(&job->error); + if (bio_error != 0) + aio_complete(job, -1, bio_error); else aio_complete(job, atomic_load_long(&job->nbytes), 0); } diff --git a/sys/sys/aio.h b/sys/sys/aio.h index 7b931d04febc..272132acf91e 100644 --- a/sys/sys/aio.h +++ b/sys/sys/aio.h @@ -151,7 +151,7 @@ struct kaiocb { aio_handle_fn_t *handle_fn; /* (c) backend handle function */ union { /* Backend-specific data fields */ struct { /* BIO backend */ - int nbio; /* Number of remaining bios */ + volatile u_int nbio; /* Number of remaining bios */ int error; /* Worst error of all bios */ long nbytes; /* Bytes completed so far */ };