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 451B1301468 for ; Tue, 24 Feb 2026 21:45:30 +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=1771969530; cv=none; b=CBFicczlEezhAU/ivNL01h0TuF8Ue1xOr732kmprSHvBetuyjHNlHi3OE4XgHjfZmsewkexJ1NdlVI/r/6cVwl4khGl6p4FwO1uY/IZHvhGHhm36VpDujPMWElX0KRMQwX6406tDS2l2cWBHykQx4o9EIFiqait/h8RvePd7v4Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771969530; c=relaxed/simple; bh=u+qccsN0DukhxWC3wiwEOxsJ/gicwqC2bQuwSHYg2fY=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=EtTNcnJuqBD15KOYcTkcbqnm5i6NN0Tp7RyKNtbh9KQdQ84JTvlPPeBBbO6IMiqvhdhNFh7TS0EJPJNvoR94KhzNyhmkBRPVnMZFm9D7NWIzp7EUZ/YGwthI/ro+EJ6ifI5Mh8Bk4CkPNlaiNcPbEtFfCJH+uW3c7SzxkPIBzx4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=N2hVsFuV; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="N2hVsFuV" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AFA24C116D0; Tue, 24 Feb 2026 21:45:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1771969529; bh=u+qccsN0DukhxWC3wiwEOxsJ/gicwqC2bQuwSHYg2fY=; h=Subject:To:Cc:From:Date:From; b=N2hVsFuV9gT+IjcN+bdAx3DeYwricUYTXFZ0v6+SoNLz81BG5pFg6yFv5ATGq10ni DLFrGxzPz0F1UBrGY4OlyfehGX2PVsXAweZqY7aIrUhrnTyplaxKXCcWbaIavatYNE YUrIIdyTu6+KQpr046Q+BaL8VUDJjo0vBobgMBI0= Subject: FAILED: patch "[PATCH] ext4: fix dirtyclusters double decrement on fs shutdown" failed to apply to 5.15-stable tree To: bfoster@redhat.com,libaokun1@huawei.com,tytso@mit.edu Cc: From: Date: Tue, 24 Feb 2026 13:45:22 -0800 Message-ID: <2026022422-deviancy-scanning-ca65@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 5.15-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-5.15.y git checkout FETCH_HEAD git cherry-pick -x 94a8cea54cd935c54fa2fba70354757c0fc245e3 # git commit -s git send-email --to '' --in-reply-to '2026022422-deviancy-scanning-ca65@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 94a8cea54cd935c54fa2fba70354757c0fc245e3 Mon Sep 17 00:00:00 2001 From: Brian Foster Date: Tue, 13 Jan 2026 12:19:05 -0500 Subject: [PATCH] ext4: fix dirtyclusters double decrement on fs shutdown fstests test generic/388 occasionally reproduces a warning in ext4_put_super() associated with the dirty clusters count: WARNING: CPU: 7 PID: 76064 at fs/ext4/super.c:1324 ext4_put_super+0x48c/0x590 [ext4] Tracing the failure shows that the warning fires due to an s_dirtyclusters_counter value of -1. IOW, this appears to be a spurious decrement as opposed to some sort of leak. Further tracing of the dirty cluster count deltas and an LLM scan of the resulting output identified the cause as a double decrement in the error path between ext4_mb_mark_diskspace_used() and the caller ext4_mb_new_blocks(). First, note that generic/388 is a shutdown vs. fsstress test and so produces a random set of operations and shutdown injections. In the problematic case, the shutdown triggers an error return from the ext4_handle_dirty_metadata() call(s) made from ext4_mb_mark_context(). The changed value is non-zero at this point, so ext4_mb_mark_diskspace_used() does not exit after the error bubbles up from ext4_mb_mark_context(). Instead, the former decrements both cluster counters and returns the error up to ext4_mb_new_blocks(). The latter falls into the !ar->len out path which decrements the dirty clusters counter a second time, creating the inconsistency. To avoid this problem and simplify ownership of the cluster reservation in this codepath, lift the counter reduction to a single place in the caller. This makes it more clear that ext4_mb_new_blocks() is responsible for acquiring cluster reservation (via ext4_claim_free_clusters()) in the !delalloc case as well as releasing it, regardless of whether it ends up consumed or returned due to failure. Fixes: 0087d9fb3f29 ("ext4: Fix s_dirty_blocks_counter if block allocation failed with nodelalloc") Signed-off-by: Brian Foster Reviewed-by: Baokun Li Link: https://patch.msgid.link/20260113171905.118284-1-bfoster@redhat.com Signed-off-by: Theodore Ts'o Cc: stable@kernel.org diff --git a/fs/ext4/mballoc-test.c b/fs/ext4/mballoc-test.c index a9416b20ff64..4abb40d4561c 100644 --- a/fs/ext4/mballoc-test.c +++ b/fs/ext4/mballoc-test.c @@ -567,7 +567,7 @@ test_mark_diskspace_used_range(struct kunit *test, bitmap = mbt_ctx_bitmap(sb, TEST_GOAL_GROUP); memset(bitmap, 0, sb->s_blocksize); - ret = ext4_mb_mark_diskspace_used(ac, NULL, 0); + ret = ext4_mb_mark_diskspace_used(ac, NULL); KUNIT_ASSERT_EQ(test, ret, 0); max = EXT4_CLUSTERS_PER_GROUP(sb); diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index de4cacb740b3..dd29558ad753 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -4186,8 +4186,7 @@ ext4_mb_mark_context(handle_t *handle, struct super_block *sb, bool state, * Returns 0 if success or error code */ static noinline_for_stack int -ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac, - handle_t *handle, unsigned int reserv_clstrs) +ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac, handle_t *handle) { struct ext4_group_desc *gdp; struct ext4_sb_info *sbi; @@ -4242,13 +4241,6 @@ ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac, BUG_ON(changed != ac->ac_b_ex.fe_len); #endif percpu_counter_sub(&sbi->s_freeclusters_counter, ac->ac_b_ex.fe_len); - /* - * Now reduce the dirty block count also. Should not go negative - */ - if (!(ac->ac_flags & EXT4_MB_DELALLOC_RESERVED)) - /* release all the reserved blocks if non delalloc */ - percpu_counter_sub(&sbi->s_dirtyclusters_counter, - reserv_clstrs); return err; } @@ -6333,7 +6325,7 @@ ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle, ext4_mb_pa_put_free(ac); } if (likely(ac->ac_status == AC_STATUS_FOUND)) { - *errp = ext4_mb_mark_diskspace_used(ac, handle, reserv_clstrs); + *errp = ext4_mb_mark_diskspace_used(ac, handle); if (*errp) { ext4_discard_allocated_blocks(ac); goto errout; @@ -6364,12 +6356,9 @@ ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle, out: if (inquota && ar->len < inquota) dquot_free_block(ar->inode, EXT4_C2B(sbi, inquota - ar->len)); - if (!ar->len) { - if ((ar->flags & EXT4_MB_DELALLOC_RESERVED) == 0) - /* release all the reserved blocks if non delalloc */ - percpu_counter_sub(&sbi->s_dirtyclusters_counter, - reserv_clstrs); - } + /* release any reserved blocks */ + if (reserv_clstrs) + percpu_counter_sub(&sbi->s_dirtyclusters_counter, reserv_clstrs); trace_ext4_allocate_blocks(ar, (unsigned long long)block);