From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:56602 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934868AbcJTPyv (ORCPT ); Thu, 20 Oct 2016 11:54:51 -0400 Subject: Patch "jbd2: fix lockdep annotation in add_transaction_credits()" has been added to the 4.8-stable tree To: jack@suse.cz, gregkh@linuxfoundation.org, tglx@linutronix.de, tytso@mit.edu Cc: , From: Date: Thu, 20 Oct 2016 17:54:07 +0200 Message-ID: <147697884724046@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled jbd2: fix lockdep annotation in add_transaction_credits() to the 4.8-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: jbd2-fix-lockdep-annotation-in-add_transaction_credits.patch and it can be found in the queue-4.8 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From e03a9976afce6634826d56c33531dd10bb9a9166 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Thu, 22 Sep 2016 11:44:06 -0400 Subject: jbd2: fix lockdep annotation in add_transaction_credits() From: Jan Kara commit e03a9976afce6634826d56c33531dd10bb9a9166 upstream. Thomas has reported a lockdep splat hitting in add_transaction_credits(). The problem is that that function calls jbd2_might_wait_for_commit() while holding j_state_lock which is wrong (we do not really wait for transaction commit while holding that lock). Fix the problem by moving jbd2_might_wait_for_commit() into places where we are ready to wait for transaction commit and thus j_state_lock is unlocked. Fixes: 1eaa566d368b214d99cbb973647c1b0b8102a9ae Reported-by: Thomas Gleixner Signed-off-by: Jan Kara Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman --- fs/jbd2/transaction.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/fs/jbd2/transaction.c +++ b/fs/jbd2/transaction.c @@ -159,6 +159,7 @@ static void wait_transaction_locked(jour read_unlock(&journal->j_state_lock); if (need_to_start) jbd2_log_start_commit(journal, tid); + jbd2_might_wait_for_commit(journal); schedule(); finish_wait(&journal->j_wait_transaction_locked, &wait); } @@ -182,8 +183,6 @@ static int add_transaction_credits(journ int needed; int total = blocks + rsv_blocks; - jbd2_might_wait_for_commit(journal); - /* * If the current transaction is locked down for commit, wait * for the lock to be released. @@ -214,6 +213,7 @@ static int add_transaction_credits(journ if (atomic_read(&journal->j_reserved_credits) + total > journal->j_max_transaction_buffers) { read_unlock(&journal->j_state_lock); + jbd2_might_wait_for_commit(journal); wait_event(journal->j_wait_reserved, atomic_read(&journal->j_reserved_credits) + total <= journal->j_max_transaction_buffers); @@ -238,6 +238,7 @@ static int add_transaction_credits(journ if (jbd2_log_space_left(journal) < jbd2_space_needed(journal)) { atomic_sub(total, &t->t_outstanding_credits); read_unlock(&journal->j_state_lock); + jbd2_might_wait_for_commit(journal); write_lock(&journal->j_state_lock); if (jbd2_log_space_left(journal) < jbd2_space_needed(journal)) __jbd2_log_wait_for_space(journal); @@ -255,6 +256,7 @@ static int add_transaction_credits(journ sub_reserved_credits(journal, rsv_blocks); atomic_sub(total, &t->t_outstanding_credits); read_unlock(&journal->j_state_lock); + jbd2_might_wait_for_commit(journal); wait_event(journal->j_wait_reserved, atomic_read(&journal->j_reserved_credits) + rsv_blocks <= journal->j_max_transaction_buffers / 2); Patches currently in stable-queue which might be from jack@suse.cz are queue-4.8/ext4-allow-dax-writeback-for-hole-punch.patch queue-4.8/mm-filemap-don-t-plant-shadow-entries-without-radix-tree-node.patch queue-4.8/reiserfs-unlock-superblock-before-calling-reiserfs_quota_on_mount.patch queue-4.8/ext4-unmap-metadata-when-zeroing-blocks.patch queue-4.8/jbd2-fix-lockdep-annotation-in-add_transaction_credits.patch