From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 4F27D4D0CF6 for ; Wed, 16 Sep 2026 17:26:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789579565; cv=none; b=scBKrENfXUG7cQBAf4fx+ic+WCQMahG7i/Dm5RBUC7J57KZoRllIyq4MDGHS2UBCz8hQYnDgBY1RVpBonADKkZpqV6Ig8fuZPS5MX7BJ3bgX3KxhkMm28tbNCeoHcFV0x/w4oGIFsokWpGKFtT95ftv/xUmdlpf//b9EAl96LKU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789579565; c=relaxed/simple; bh=aGkijWri3u+H0hpFqmpraAVe0Fv5oein7qZtUDJ9g6Y=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=thsy+iwAlADLBr50NqsdHFnspk4dj4HHMWQq6Gb60Sh7aXRapDbLdg+4SGt8CjeM6Rs9OGG5uDGSqs1Osj6u72Fsio+VbnNbtP41l7VjqQQxigFofLeDGmjxKSDUOItyux+J/s65CQUawB8sYHL9BplZDIvqhtuLFdnsp6OByYw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=uBWXx6nW; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="uBWXx6nW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5D7E51F000FF; Wed, 16 Sep 2026 17:26:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789579563; bh=gFSFyR8C3oe4Yz2FqiH/WCD0KvEPBhVnj3XTXG174nw=; h=Subject:To:Cc:From:Date; b=uBWXx6nWVWSEt0n3IlBsWV8B4lWuOUJkNnWzFT5hHi6yDeqje63N4YViK/xQVw1D8 GrduhExie4MkJ6tLNTswrcItfsA7l/Inja3kH87GCU1y6BfaaLdzXc6MEhfjzX7PjQ IubyCP+ILPC0jRUX+5wjlwsajcP0VFhnJ4PsyBqE= Subject: FAILED: patch "[PATCH] xfs: snapshot old AGFL before rewriting it" failed to apply to 6.1-stable tree To: djwong@kernel.org,cem@kernel.org,cmaiolino@redhat.com,hch@lst.de Cc: From: Date: Wed, 16 Sep 2026 18:21:28 +0100 Message-ID: <2026091628-remarry-broadness-51ba@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x 3466dfef0a20f842363958deea55be9f1d26818a # git commit -s git send-email --to '' --in-reply-to '2026091628-remarry-broadness-51ba@gregkh' --subject-prefix 'PATCH 6.1.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 3466dfef0a20f842363958deea55be9f1d26818a Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Tue, 8 Sep 2026 23:04:04 -0700 Subject: [PATCH] xfs: snapshot old AGFL before rewriting it LOLLM complains that we can't undo an attempt at fixing the AGFL if anything goes wrong during the rewrite, so take a snapshot of the whole buffer so that we can restore it. Move the xrep_agfl_update_agf call so that we only update the AGF if the AGFL update is 100% successful. While we're at it, fix leaking the used_extents bitmap if the disunion operation fails. Cc: stable@vger.kernel.org # v4.19 Fixes: 0e93d3f43ec7d3 ("xfs: repair the AGFL") Signed-off-by: Darrick J. Wong Assisted-by: LOLLM # finding obvious bugs Reviewed-by: Carlos Maiolino Reviewed-by: Christoph Hellwig Signed-off-by: Carlos Maiolino diff --git a/fs/xfs/scrub/agheader_repair.c b/fs/xfs/scrub/agheader_repair.c index 2104512f1ee1..46c95354ca64 100644 --- a/fs/xfs/scrub/agheader_repair.c +++ b/fs/xfs/scrub/agheader_repair.c @@ -668,14 +668,16 @@ xrep_agfl_init_header( struct xfs_scrub *sc, struct xfs_buf *agfl_bp, struct xagb_bitmap *agfl_extents, - xfs_agblock_t flcount) + xfs_agblock_t flcount, + struct xfs_agfl *old_agfl) { struct xrep_agfl_fill af = { .sc = sc, .flcount = flcount, }; struct xfs_mount *mp = sc->mp; - struct xfs_agfl *agfl; + struct xfs_agfl *agfl = XFS_BUF_TO_AGFL(agfl_bp); + const size_t agfl_sz = BBTOB(agfl_bp->b_length); int error; ASSERT(flcount <= xfs_agfl_size(mp)); @@ -684,8 +686,8 @@ xrep_agfl_init_header( * Start rewriting the header by setting the bno[] array to * NULLAGBLOCK, then setting AGFL header fields. */ - agfl = XFS_BUF_TO_AGFL(agfl_bp); - memset(agfl, 0xFF, BBTOB(agfl_bp->b_length)); + memcpy(old_agfl, agfl, agfl_sz); + memset(agfl, 0xFF, agfl_sz); agfl->agfl_magicnum = cpu_to_be32(XFS_AGFL_MAGIC); agfl->agfl_seqno = cpu_to_be32(pag_agno(sc->sa.pag)); uuid_copy(&agfl->agfl_uuid, &mp->m_sb.sb_meta_uuid); @@ -700,13 +702,18 @@ xrep_agfl_init_header( xagb_bitmap_walk(agfl_extents, xrep_agfl_fill, &af); error = xagb_bitmap_disunion(agfl_extents, &af.used_extents); if (error) - return error; + goto err_undo; /* Write new AGFL to disk. */ xfs_trans_buf_set_type(sc->tp, agfl_bp, XFS_BLFT_AGFL_BUF); - xfs_trans_log_buf(sc->tp, agfl_bp, 0, BBTOB(agfl_bp->b_length) - 1); + xfs_trans_log_buf(sc->tp, agfl_bp, 0, agfl_sz - 1); xagb_bitmap_destroy(&af.used_extents); return 0; + +err_undo: + xagb_bitmap_destroy(&af.used_extents); + memcpy(agfl, old_agfl, agfl_sz); + return error; } /* Repair the AGFL. */ @@ -718,6 +725,7 @@ xrep_agfl( struct xfs_mount *mp = sc->mp; struct xfs_buf *agf_bp; struct xfs_buf *agfl_bp; + struct xfs_agfl *old_agfl; xfs_agblock_t flcount; int error; @@ -725,6 +733,10 @@ xrep_agfl( if (!xfs_has_rmapbt(mp)) return -EOPNOTSUPP; + old_agfl = kzalloc(BBTOB(XFS_FSS_TO_BB(mp, 1)), XCHK_GFP_FLAGS); + if (!old_agfl) + return -ENOMEM; + xagb_bitmap_init(&agfl_extents); /* @@ -734,7 +746,7 @@ xrep_agfl( */ error = xfs_alloc_read_agf(sc->sa.pag, sc->tp, 0, &agf_bp); if (error) - return error; + goto err_old_agfl; /* * Make sure we have the AGFL buffer, as scrub might have decided it @@ -745,7 +757,7 @@ xrep_agfl( XFS_AGFL_DADDR(mp)), XFS_FSS_TO_BB(mp, 1), 0, &agfl_bp, NULL); if (error) - return error; + goto err_old_agfl; agfl_bp->b_ops = &xfs_agfl_buf_ops; /* Gather all the extents we're going to put on the new AGFL. */ @@ -762,10 +774,11 @@ xrep_agfl( * we adjust the AGF flcount (which can fail) so avoid updating any * buffers until we know that part works. */ - xrep_agfl_update_agf(sc, agf_bp, flcount); - error = xrep_agfl_init_header(sc, agfl_bp, &agfl_extents, flcount); + error = xrep_agfl_init_header(sc, agfl_bp, &agfl_extents, flcount, + old_agfl); if (error) goto err; + xrep_agfl_update_agf(sc, agf_bp, flcount); /* * Ok, the AGFL should be ready to go now. Roll the transaction to @@ -785,6 +798,8 @@ xrep_agfl( err: xagb_bitmap_destroy(&agfl_extents); +err_old_agfl: + kfree(old_agfl); return error; }