From: Omar Sandoval <[email protected]> This can be used to diagnose freeze-related hangs.
Signed-off-by: Omar Sandoval <[email protected]> --- block/blk-mq-debugfs.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c index f6d917977b33..1459546788da 100644 --- a/block/blk-mq-debugfs.c +++ b/block/blk-mq-debugfs.c @@ -29,6 +29,26 @@ struct blk_mq_debugfs_attr { const struct file_operations *fops; }; +static int queue_freeze_depth_show(struct seq_file *m, void *v) +{ + struct request_queue *q = m->private; + + seq_printf(m, "%d\n", atomic_read(&q->mq_freeze_depth)); + return 0; +} + +static int queue_freeze_depth_open(struct inode *inode, struct file *file) +{ + return single_open(file, queue_freeze_depth_show, inode->i_private); +} + +static const struct file_operations queue_freeze_depth_fops = { + .open = queue_freeze_depth_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + static int blk_mq_debugfs_seq_open(struct inode *inode, struct file *file, const struct seq_operations *ops) { @@ -636,6 +656,11 @@ static const struct file_operations ctx_completed_fops = { .release = single_release, }; +static const struct blk_mq_debugfs_attr blk_mq_debugfs_queue_attrs[] = { + {"freeze_depth", 0400, &queue_freeze_depth_fops}, + {}, +}; + static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = { {"state", 0400, &hctx_state_fops}, {"flags", 0400, &hctx_flags_fops}, @@ -753,6 +778,9 @@ int blk_mq_debugfs_register_hctxs(struct request_queue *q) if (!q->mq_debugfs_dir) goto err; + if (!debugfs_create_files(q->mq_debugfs_dir, q, blk_mq_debugfs_queue_attrs)) + return -ENOMEM; + queue_for_each_hw_ctx(q, hctx, i) { if (blk_mq_debugfs_register_hctx(q, hctx)) goto err; -- 2.12.0
