From: Tetsuo Handa Date: Wed, 22 Oct 2025 11:11:37 +0000 (+0900) Subject: jbd2: use a per-journal lock_class_key for jbd2_trans_commit_key X-Git-Tag: v6.19-rc1~161^2~41 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=524c3853831cf4f7e1db579e487c757c3065165c;p=thirdparty%2Fkernel%2Flinux.git jbd2: use a per-journal lock_class_key for jbd2_trans_commit_key syzbot is reporting possibility of deadlock due to sharing lock_class_key for jbd2_handle across ext4 and ocfs2. But this is a false positive, for one disk partition can't have two filesystems at the same time. Reported-by: syzbot+6e493c165d26d6fcbf72@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=6e493c165d26d6fcbf72 Signed-off-by: Tetsuo Handa Tested-by: syzbot+6e493c165d26d6fcbf72@syzkaller.appspotmail.com Reviewed-by: Jan Kara Message-ID: <987110fc-5470-457a-a218-d286a09dd82f@I-love.SAKURA.ne.jp> Signed-off-by: Theodore Ts'o Cc: stable@kernel.org --- diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index d480b94117cd7..f43474002f50f 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -1521,7 +1521,6 @@ static journal_t *journal_init_common(struct block_device *bdev, struct block_device *fs_dev, unsigned long long start, int len, int blocksize) { - static struct lock_class_key jbd2_trans_commit_key; journal_t *journal; int err; int n; @@ -1530,6 +1529,7 @@ static journal_t *journal_init_common(struct block_device *bdev, if (!journal) return ERR_PTR(-ENOMEM); + lockdep_register_key(&journal->jbd2_trans_commit_key); journal->j_blocksize = blocksize; journal->j_dev = bdev; journal->j_fs_dev = fs_dev; @@ -1560,7 +1560,7 @@ static journal_t *journal_init_common(struct block_device *bdev, journal->j_max_batch_time = 15000; /* 15ms */ atomic_set(&journal->j_reserved_credits, 0); lockdep_init_map(&journal->j_trans_commit_map, "jbd2_handle", - &jbd2_trans_commit_key, 0); + &journal->jbd2_trans_commit_key, 0); /* The journal is marked for error until we succeed with recovery! */ journal->j_flags = JBD2_ABORT; @@ -1611,6 +1611,7 @@ err_cleanup: kfree(journal->j_wbuf); jbd2_journal_destroy_revoke(journal); journal_fail_superblock(journal); + lockdep_unregister_key(&journal->jbd2_trans_commit_key); kfree(journal); return ERR_PTR(err); } @@ -2187,6 +2188,7 @@ int jbd2_journal_destroy(journal_t *journal) jbd2_journal_destroy_revoke(journal); kfree(journal->j_fc_wbuf); kfree(journal->j_wbuf); + lockdep_unregister_key(&journal->jbd2_trans_commit_key); kfree(journal); return err; diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h index 43b9297fe8a75..f5eaf76198f37 100644 --- a/include/linux/jbd2.h +++ b/include/linux/jbd2.h @@ -1253,6 +1253,12 @@ struct journal_s */ struct lockdep_map j_trans_commit_map; #endif + /** + * @jbd2_trans_commit_key: + * + * "struct lock_class_key" for @j_trans_commit_map + */ + struct lock_class_key jbd2_trans_commit_key; /** * @j_fc_cleanup_callback: