diff options
Diffstat (limited to '0001-block-loop-convert-to-per-device-workqueue.patch')
| -rw-r--r-- | 0001-block-loop-convert-to-per-device-workqueue.patch | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/0001-block-loop-convert-to-per-device-workqueue.patch b/0001-block-loop-convert-to-per-device-workqueue.patch new file mode 100644 index 000000000000..3b426c7b4ac5 --- /dev/null +++ b/0001-block-loop-convert-to-per-device-workqueue.patch @@ -0,0 +1,133 @@ +From ebcacf05168d9791d39c5434164c64b9ef937171 Mon Sep 17 00:00:00 2001 +From: Ming Lei <ming.lei@canonical.com> +Date: Tue, 5 May 2015 19:49:54 +0800 +Subject: [PATCH 1/2] block: loop: convert to per-device workqueue + +Documentation/workqueue.txt: + If there is dependency among multiple work items used + during memory reclaim, they should be queued to separate + wq each with WQ_MEM_RECLAIM. + +Loop devices can be stacked, so we have to convert to per-device +workqueue. One example is Fedora live CD. + +Fixes: b5dd2f6047ca108001328aac0e8588edd15f1778 +Cc: stable@vger.kernel.org (v4.0) +Cc: Justin M. Forbes <jforbes@fedoraproject.org> +Signed-off-by: Ming Lei <ming.lei@canonical.com> +Acked-by: Tejun Heo <tj@kernel.org> +Signed-off-by: Jens Axboe <axboe@fb.com> +--- + drivers/block/loop.c | 30 ++++++++++++++---------------- + drivers/block/loop.h | 1 + + 2 files changed, 15 insertions(+), 16 deletions(-) + +diff --git a/drivers/block/loop.c b/drivers/block/loop.c +index d1f168b..fec06d5 100644 +--- a/drivers/block/loop.c ++++ b/drivers/block/loop.c +@@ -85,8 +85,6 @@ static DEFINE_MUTEX(loop_index_mutex); + static int max_part; + static int part_shift; + +-static struct workqueue_struct *loop_wq; +- + /* + * Transfer functions + */ +@@ -777,6 +775,12 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode, + size = get_loop_size(lo, file); + if ((loff_t)(sector_t)size != size) + goto out_putf; ++ error = -ENOMEM; ++ lo->wq = alloc_workqueue("kloopd%d", ++ WQ_MEM_RECLAIM | WQ_HIGHPRI | WQ_UNBOUND, 0, ++ lo->lo_number); ++ if (!lo->wq) ++ goto out_putf; + + error = 0; + +@@ -924,6 +928,8 @@ static int loop_clr_fd(struct loop_device *lo) + lo->lo_flags = 0; + if (!part_shift) + lo->lo_disk->flags |= GENHD_FL_NO_PART_SCAN; ++ destroy_workqueue(lo->wq); ++ lo->wq = NULL; + mutex_unlock(&lo->lo_ctl_mutex); + /* + * Need not hold lo_ctl_mutex to fput backing file. +@@ -1477,9 +1483,13 @@ static int loop_queue_rq(struct blk_mq_hw_ctx *hctx, + const struct blk_mq_queue_data *bd) + { + struct loop_cmd *cmd = blk_mq_rq_to_pdu(bd->rq); ++ struct loop_device *lo = cmd->rq->q->queuedata; + + blk_mq_start_request(bd->rq); + ++ if (lo->lo_state != Lo_bound) ++ return -EIO; ++ + if (cmd->rq->cmd_flags & REQ_WRITE) { + struct loop_device *lo = cmd->rq->q->queuedata; + bool need_sched = true; +@@ -1493,9 +1503,9 @@ static int loop_queue_rq(struct blk_mq_hw_ctx *hctx, + spin_unlock_irq(&lo->lo_lock); + + if (need_sched) +- queue_work(loop_wq, &lo->write_work); ++ queue_work(lo->wq, &lo->write_work); + } else { +- queue_work(loop_wq, &cmd->read_work); ++ queue_work(lo->wq, &cmd->read_work); + } + + return BLK_MQ_RQ_QUEUE_OK; +@@ -1507,9 +1517,6 @@ static void loop_handle_cmd(struct loop_cmd *cmd) + struct loop_device *lo = cmd->rq->q->queuedata; + int ret = -EIO; + +- if (lo->lo_state != Lo_bound) +- goto failed; +- + if (write && (lo->lo_flags & LO_FLAGS_READ_ONLY)) + goto failed; + +@@ -1858,13 +1865,6 @@ static int __init loop_init(void) + goto misc_out; + } + +- loop_wq = alloc_workqueue("kloopd", +- WQ_MEM_RECLAIM | WQ_HIGHPRI | WQ_UNBOUND, 0); +- if (!loop_wq) { +- err = -ENOMEM; +- goto misc_out; +- } +- + blk_register_region(MKDEV(LOOP_MAJOR, 0), range, + THIS_MODULE, loop_probe, NULL, NULL); + +@@ -1902,8 +1902,6 @@ static void __exit loop_exit(void) + blk_unregister_region(MKDEV(LOOP_MAJOR, 0), range); + unregister_blkdev(LOOP_MAJOR, "loop"); + +- destroy_workqueue(loop_wq); +- + misc_deregister(&loop_misc); + } + +diff --git a/drivers/block/loop.h b/drivers/block/loop.h +index 301c27f..49564ed 100644 +--- a/drivers/block/loop.h ++++ b/drivers/block/loop.h +@@ -54,6 +54,7 @@ struct loop_device { + gfp_t old_gfp_mask; + + spinlock_t lo_lock; ++ struct workqueue_struct *wq; + struct list_head write_cmd_head; + struct work_struct write_work; + bool write_started; +-- +2.4.5 + |