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 5717A77F39; Thu, 26 Mar 2026 02:52:03 +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=1774493523; cv=none; b=pn83FAJBFob1tAebRili3/aTGSHqvc1nGHLxpsHtVZVu9uedwwPwpPXLVGrYQZ8YZZIT1GJiwZcEqC0imi7SHIu2B8H9tT+XOtAlaG8PGhVpHT4+gxeuGQ/804wXUkd69CP1n01AuskB977eE46mmdgwnL64i0kFTltafPn1TkQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774493523; c=relaxed/simple; bh=A+GXnGT9Ep3iwufn3Pmxa7uHTI+2orro7gkD2bePT7c=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=AQQDAesOYrngSXNyO7h0jEtrhreRz0wZ1zanzmWM2G8GT9nD2z4n+4RZtRJ8tjRgpdU5zYbYCw+XeFBaE9vnqbXSq4gSM8IG//Cnf8BMvZHwI/vokAMtL+TNG+XX6kJ+oHP8dcFwDW10id0St8efWhW/w5Y+YkCl591pE2nq7+o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=E96b6OMM; 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="E96b6OMM" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 94256C4CEF7; Thu, 26 Mar 2026 02:51:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774493523; bh=A+GXnGT9Ep3iwufn3Pmxa7uHTI+2orro7gkD2bePT7c=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=E96b6OMMq/PGfVGGxG5F3VmYcRtn3DwFeCyF82CcVS9/vmB9a3WA4IXux2MzLienI +O/VDw+ck3Yrh/h65c4dSafbBUXcYGFqy7xgGiSV6f4nUnkwzgIpEx+4P9md9kFB0O 4E2/YaY65xyaWw0tq+8l9FJWzpI+oIAYYlEtrMDRCLRr6l8bIKTtKQUVtwnU4HJRjh IrLYUXLTCnBO27noyggqzgGAAQPExY+tpeOFndnqxyV/jY/rk4NdwHjpir3DiuODKw sqt3ul0ERaBwiiFKbB6WTzR0snVMeltCsP9gYZZ10tNqn4liWsjK0zi+YB2c0F5Luw +nE5n6BwditIg== Date: Thu, 26 Mar 2026 13:51:54 +1100 From: Dave Chinner To: Hans Holmberg Cc: Carlos Maiolino , Dave Chinner , "Darrick J . Wong" , Christoph Hellwig , Damien Le Moal , linux-xfs@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH v2] xfs: start gc on zonegc_low_space attribute updates Message-ID: References: <20260325124312.26349-1-hans.holmberg@wdc.com> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260325124312.26349-1-hans.holmberg@wdc.com> On Wed, Mar 25, 2026 at 01:43:12PM +0100, Hans Holmberg wrote: > Start gc if the agressiveness of zone garbage collection is changed > by the user (if the file system is not read only). > > Without this change, the new setting will not be taken into account > until the gc thread is woken up by e.g. a write. > > Cc: # v6.15 > Fixes: 845abeb1f06a8a ("xfs: add tunable threshold parameter for triggering zone GC") > Signed-off-by: Hans Holmberg > --- > > v2: > - Added a new helper to wake up the gc thread in stead of unparking it, > which is required to make this work properly. > - Added protection against races with unmounts as sysfs gets torn down > after the zone info struct is freed. This also avoids unneded > wakeups during remount. Isn't that a deadlock vector? i.e. unmount takes s_umount, concurrently userspace writes a new value to sysfs file. sysfs file write blocks on s_umount, unmount blocks holding s_umount waiting for sysfs file reference count to go to zero to destroy it? -Dave. -- Dave Chinner dgc@kernel.org