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 700DF35958; Mon, 23 Mar 2026 16:21:09 +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=1774282869; cv=none; b=ifRCWQ9DpITweTD3bq2zyfcIpSuMKMeeccmwlJ92h9rOuHJzhQYvIo46TyTJ92It2WFfEXIeP0VZ08gwdwUNzd8yNaOQOCQigfL4mvlHP9mELeyeboU6fZcDQISg+bLSrFdEE9r8OCs6zCN9bhOuTR+lNimHT4kR7FfyzvdDfHU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774282869; c=relaxed/simple; bh=fGtb9jzHxxEcjquKeI7+Rc6qSmp58yFRrZIP6tg2PAA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=q1qVcbR3GJ6Ja5ccNdEw7v1J1CYnRvp5MEF+UvMCuJQYKupY8xT+UwVUUiFBJyQbPIsMHJfqLihxJwDp5ENDC3UhFkZtcJG7W8Fmv7HkfrxYnSgcF51CcVIkRtyijRSjV7OXf682HhGrw0GKXCRCWw8uVUG5k+xjDi2La1HKWQ0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=u9ZPuJzo; 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="u9ZPuJzo" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 02703C4CEF7; Mon, 23 Mar 2026 16:21:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1774282869; bh=fGtb9jzHxxEcjquKeI7+Rc6qSmp58yFRrZIP6tg2PAA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=u9ZPuJzoN8k2IAPdaa7qfaTDh9yQXZmnexfl/XBER/dZMkXiXaxgUhMKqmLtQ4IUs eTG+HW+d4R5G2Z6PqXSq7O1OCiH0sGjQ19GDwQDerAU2+wdjhEVf5zqSd7cKkqH52/ d1NrkEnCnn+eIiNYphr+tdkbt1VckiaKQu0MvhkQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Brian Foster , Baokun Li , Theodore Tso , stable@kernel.org, Sasha Levin Subject: [PATCH 6.1 315/481] ext4: fix dirtyclusters double decrement on fs shutdown Date: Mon, 23 Mar 2026 14:44:57 +0100 Message-ID: <20260323134532.780372313@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260323134525.256603107@linuxfoundation.org> References: <20260323134525.256603107@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Brian Foster [ Upstream commit 94a8cea54cd935c54fa2fba70354757c0fc245e3 ] 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 [ Drop mballoc-test changes ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- fs/ext4/mballoc.c | 21 +++++---------------- 1 file changed, 5 insertions(+), 16 deletions(-) --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -3815,8 +3815,7 @@ void ext4_exit_mballoc(void) * 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 buffer_head *bitmap_bh = NULL; struct ext4_group_desc *gdp; @@ -3904,13 +3903,6 @@ ext4_mb_mark_diskspace_used(struct ext4_ ext4_unlock_group(sb, ac->ac_b_ex.fe_group); 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); if (sbi->s_log_groups_per_flex) { ext4_group_t flex_group = ext4_flex_group(sbi, @@ -5804,7 +5796,7 @@ repeat: ext4_mb_pa_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; @@ -5836,12 +5828,9 @@ out: kmem_cache_free(ext4_ac_cachep, ac); 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);