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 D41A52D0C79; Sun, 1 Mar 2026 01:33:38 +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=1772328818; cv=none; b=HD19dGJMhXhQgdcEwRyUiyRbjDOaM4bfCwX5jxYUHmX+1j8qUhZng8hu9/G4qDkrzUZYbd2cbEmXhVGPvEQJJdekh8QhuwiN16TfwbBmgSS9yVVf20a8UdmtPaIOdo46gDd9lwPPu7KQFB3YT6EBcpGhY/Q+qJ/ZmjrQ4CrDPeQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772328818; c=relaxed/simple; bh=bbnxhDkgqj8+2K2uhb7dq1w6jFLvUJ5r6VAomHB4Dm4=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=jXG3ldpNCUyX+xh1cMEHmy7KFYG7h2u3Qb+NmuyGbIekIFknl39plE5eMSBa3acLKXWfmHzgY62L3jNTggLJXEKkLxTWMPF4rqw1WBFCduH96RmThGkDm07seU6T6MLAXoNBhVIdJ4AD/VDh2u4VLK9nQVf0dCkSss8IeVh1o3s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GDWwLC9r; 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="GDWwLC9r" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0D574C19421; Sun, 1 Mar 2026 01:33:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772328818; bh=bbnxhDkgqj8+2K2uhb7dq1w6jFLvUJ5r6VAomHB4Dm4=; h=From:To:Cc:Subject:Date:From; b=GDWwLC9rOFY6V7JcE09p4vZLMeD2K/jr/4+ru4f635SEht0kV2KmsM9VT2X135z++ nWCB4t2eq0ctrV9207fCJRbFsxxa+CXMDCNhXpa49TCnbpz9McYj1NiKBbQPI3hltz g9FjLheAaxaVzDfJNCSANCrhhWD21g6m2SjjA698sdTCl/PMwUI28O5961hAWZ0m+z O4a7HhiurlSvrJw7IZIcGh6k0yfogJfPeeQ6ufvws+tRHPPuMpkftvIu+YhNeAGOex AkzwXet1Bl/JZ6wAl5OAZCzTggk7vGhE5LSSRg+WgFXArCCMBiNkCZrSeEM+1u3XxI 8FrcSBA3tuJzQ== From: Sasha Levin To: stable@vger.kernel.org, bfoster@redhat.com Cc: Baokun Li , Theodore Ts'o , stable@kernel.org, linux-ext4@vger.kernel.org Subject: FAILED: Patch "ext4: fix dirtyclusters double decrement on fs shutdown" failed to apply to 6.6-stable tree Date: Sat, 28 Feb 2026 20:33:36 -0500 Message-ID: <20260301013336.1692882-1-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Hint: ignore X-stable: review Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.6-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 . Thanks, Sasha ------------------ 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 --- fs/ext4/mballoc-test.c | 2 +- fs/ext4/mballoc.c | 21 +++++---------------- 2 files changed, 6 insertions(+), 17 deletions(-) diff --git a/fs/ext4/mballoc-test.c b/fs/ext4/mballoc-test.c index a9416b20ff64c..4abb40d4561ce 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 de4cacb740b33..dd29558ad753b 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); -- 2.51.0