From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6E89F312829; Mon, 17 Nov 2025 18:21:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763403696; cv=none; b=evMV0QulMZrFUck2U63MnfqbnqmfCfXV25FY7kssZK9EfVlDumrbbn0yjZzzsn1iM9UoC9oTY6zaWLcQLS/SIYVXiBvmjJcxDD8nPPCmzPyU88My4vaJGt6AWQdVbgYLPU5Vn1YuSHN+Nr6uoGnrdKGtDSFKk+DgOtAyAQ+jz7g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763403696; c=relaxed/simple; bh=2yisANE7qjI9IISnPxhYqY2yn6Md2ZHrrpDB3XpbIOw=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=HRZqFEU/tSmjmd43IBJdtzWcTbEEJb6knAERDWSf56JKOS3+031PaTSH5H7pVs8c2apVThhn7AcRcuyhF6AMJgWsLVXT2TD4MjujCHGb3wvA7STXG74m10Wx/wClUjArmXqpfTxYm+ZHz313jYATCYMwKCMenjV9V7OuqQwCmsE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=eyqM01mu; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="eyqM01mu" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3295BC2BCB2; Mon, 17 Nov 2025 18:21:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1763403695; bh=2yisANE7qjI9IISnPxhYqY2yn6Md2ZHrrpDB3XpbIOw=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=eyqM01mu5dcY4s04TTk8DUmlsmv4u6ZHm/RBNirRm8y0boW4sR9zElwcCj1omt3S1 u254ZPzt3wE0j9af2yTywcB9CAqABXakGEUXVTc6r5WWVE9UeJh8kon2HEvuSk+WlJ CJE4Q7zUsHiCYWk+dv2n1vI4l/9NFpnRM3HuomWQXlUG0XQDUe7hvXoVWKwMz+VxjM tgt2SH5BYxGTxL4vUJJZbMXHUwmpYuOJfju/eJuWXW0I0gG6dFpRgLSk2Txk/MD1i6 E3q7/KHwXLwiWYxFyBFfNvYpIZEVlQGgkgpcrNgbfvXVDwfmJD6yqFpf1tyWSX64Ni 8YSo49WF6Fx6Q== Message-ID: <5d19304ea493177c35d0ce13abe6dbf358240fa1.camel@kernel.org> Subject: Re: [PATCH v4 2/3] locks: Threads with layout conflict must wait until client was fenced. From: Jeff Layton To: Dai Ngo , chuck.lever@oracle.com, neilb@ownmail.net, okorniev@redhat.com, tom@talpey.com, hch@lst.de, alex.aring@gmail.com, viro@zeniv.linux.org.uk, brauner@kernel.org, jack@suse.cz Cc: linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org Date: Mon, 17 Nov 2025 13:21:32 -0500 In-Reply-To: <20251115191722.3739234-3-dai.ngo@oracle.com> References: <20251115191722.3739234-1-dai.ngo@oracle.com> <20251115191722.3739234-3-dai.ngo@oracle.com> Autocrypt: addr=jlayton@kernel.org; prefer-encrypt=mutual; keydata=mQINBE6V0TwBEADXhJg7s8wFDwBMEvn0qyhAnzFLTOCHooMZyx7XO7dAiIhDSi7G1NPxw n8jdFUQMCR/GlpozMFlSFiZXiObE7sef9rTtM68ukUyZM4pJ9l0KjQNgDJ6Fr342Htkjxu/kFV1Wv egyjnSsFt7EGoDjdKqr1TS9syJYFjagYtvWk/UfHlW09X+jOh4vYtfX7iYSx/NfqV3W1D7EDi0PqV T2h6v8i8YqsATFPwO4nuiTmL6I40ZofxVd+9wdRI4Db8yUNA4ZSP2nqLcLtFjClYRBoJvRWvsv4lm 0OX6MYPtv76hka8lW4mnRmZqqx3UtfHX/hF/zH24Gj7A6sYKYLCU3YrI2Ogiu7/ksKcl7goQjpvtV YrOOI5VGLHge0awt7bhMCTM9KAfPc+xL/ZxAMVWd3NCk5SamL2cE99UWgtvNOIYU8m6EjTLhsj8sn 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DfX/sn9XcfoVZIxMpCRE750zvJvcCUz9HojsrMQ1NFc7MFT1z3MOW2/RlzPcog7xvR5ENPH19ojRD CHqumUHRry+RF0lH00clzX/W8OrQJZtoBPXv9ahka/Vp7kEulcBJr1cH5Wz/WprhsIM7U9pse1f1g Yy9YbXtWctUz8uvDR7shsQxAhX3qO7DilMtuGo1v97I/Kx4gXQ52syh/w6EBny71CZrOgD6kJwPVV AaM1LRC28muq91WCFhs/nzHozpbzcheyGtMUI2Ao4K6mnY+3zIuXPygZMFr9KXE6fF7HzKxKuZMJO aEZCiDOq0anx6FmOzs5E6Jqdpo/mtI8beK+BE7Va6ni7YrQlnT0i3vaTVMTiCThbqsB20VrbMjlhp f8lfK1XVNbRq/R7GZ9zHESlsa35ha60yd/j3pu5hT2xyy8krV8vGhHvnJ1XRMJBAB/UYb6FyC7S+m QZIQXVeAA+smfTT0tDrisj1U5x6ZB9b3nBg65kc= Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.58.1 (3.58.1-1.fc43) Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Sat, 2025-11-15 at 11:16 -0800, Dai Ngo wrote: > If multiple threads are waiting for a layout conflict on the same > file in __break_lease, these threads must wait until one of the > waiting threads completes the fencing operation before proceeding. > This ensures that I/O operations from these threads can only occurs > after the client was fenced. >=20 > Fixes: f99d4fbdae67 ("nfsd: add SCSI layout support") > Signed-off-by: Dai Ngo > --- > fs/locks.c | 24 ++++++++++++++++++++++++ > include/linux/filelock.h | 5 +++++ > 2 files changed, 29 insertions(+) >=20 > diff --git a/fs/locks.c b/fs/locks.c > index 1f254e0cd398..b6fd6aa2498c 100644 > --- a/fs/locks.c > +++ b/fs/locks.c > @@ -191,6 +191,7 @@ locks_get_lock_context(struct inode *inode, int type) > INIT_LIST_HEAD(&ctx->flc_flock); > INIT_LIST_HEAD(&ctx->flc_posix); > INIT_LIST_HEAD(&ctx->flc_lease); > + init_waitqueue_head(&ctx->flc_dispose_wait); > =20 > /* > * Assign the pointer if it's not already assigned. If it is, then > @@ -1609,6 +1610,10 @@ int __break_lease(struct inode *inode, unsigned in= t mode, unsigned int type) > error =3D -EWOULDBLOCK; > goto out; > } > + if (type =3D=3D FL_LAYOUT && !ctx->flc_conflict) { > + ctx->flc_conflict =3D true; > + ctx->flc_wait_for_dispose =3D false; > + } I don't like special casing this for FL_LAYOUT leases. It seems like we ought to be able to set up a lm_breaker_timedout operation on any sort of lease. > =20 > restart: > fl =3D list_first_entry(&ctx->flc_lease, struct file_lease, c.flc_list)= ; > @@ -1640,12 +1645,31 @@ int __break_lease(struct inode *inode, unsigned i= nt mode, unsigned int type) > time_out_leases(inode, &dispose); > if (any_leases_conflict(inode, new_fl)) > goto restart; > + if (type =3D=3D FL_LAYOUT && ctx->flc_wait_for_dispose) { > + /* > + * wait for flc_wait_for_dispose to ensure > + * the offending client has been fenced. > + */ > + spin_unlock(&ctx->flc_lock); > + wait_event_interruptible(ctx->flc_dispose_wait, > + ctx->flc_wait_for_dispose =3D=3D false); > + spin_lock(&ctx->flc_lock); > + } > error =3D 0; > + if (type =3D=3D FL_LAYOUT) > + ctx->flc_wait_for_dispose =3D true; > } > out: > spin_unlock(&ctx->flc_lock); > percpu_up_read(&file_rwsem); > locks_dispose_list(&dispose); > + if (type =3D=3D FL_LAYOUT) { > + spin_lock(&ctx->flc_lock); > + ctx->flc_wait_for_dispose =3D false; > + ctx->flc_conflict =3D false; > + wake_up(&ctx->flc_dispose_wait); > + spin_unlock(&ctx->flc_lock); > + } > free_lock: > locks_free_lease(new_fl); > return error; > diff --git a/include/linux/filelock.h b/include/linux/filelock.h > index 06ccd6b66012..5c5353aabbc8 100644 > --- a/include/linux/filelock.h > +++ b/include/linux/filelock.h > @@ -146,6 +146,11 @@ struct file_lock_context { > struct list_head flc_flock; > struct list_head flc_posix; > struct list_head flc_lease; > + > + /* for FL_LAYOUT */ > + bool flc_conflict; > + bool flc_wait_for_dispose; I'm also not a fan of this particular bool. Waiting for any lm_breaker_timeout operations to complete seems like something we ought to just always do. In the trivial case where we have no special fencing to do, that should just return quickly anyway. > + wait_queue_head_t flc_dispose_wait; > }; > =20 > #ifdef CONFIG_FILE_LOCKING --=20 Jeff Layton