From 1e1a9cecfab3f22ebef0a976f849c87be8d03c1c Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 31 Jan 2025 13:03:47 +0100 Subject: block: force noio scope in blk_mq_freeze_queue When block drivers or the core block code perform allocations with a frozen queue, this could try to recurse into the block device to reclaim memory and deadlock. Thus all allocations done by a process that froze a queue need to be done without __GFP_IO and __GFP_FS. Instead of tying to track all of them down, force a noio scope as part of freezing the queue. Note that nvme is a bit of a mess here due to the non-owner freezes, and they will be addressed separately. Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20250131120352.1315351-2-hch@lst.de Signed-off-by: Jens Axboe --- drivers/scsi/scsi_scan.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'drivers/scsi/scsi_scan.c') diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c index 042329b74c6e..312d78213954 100644 --- a/drivers/scsi/scsi_scan.c +++ b/drivers/scsi/scsi_scan.c @@ -220,6 +220,7 @@ static int scsi_realloc_sdev_budget_map(struct scsi_device *sdev, int new_shift = sbitmap_calculate_shift(depth); bool need_alloc = !sdev->budget_map.map; bool need_free = false; + unsigned int memflags; int ret; struct sbitmap sb_backup; @@ -240,7 +241,7 @@ static int scsi_realloc_sdev_budget_map(struct scsi_device *sdev, * and here disk isn't added yet, so freezing is pretty fast */ if (need_free) { - blk_mq_freeze_queue(sdev->request_queue); + memflags = blk_mq_freeze_queue(sdev->request_queue); sb_backup = sdev->budget_map; } ret = sbitmap_init_node(&sdev->budget_map, @@ -256,7 +257,7 @@ static int scsi_realloc_sdev_budget_map(struct scsi_device *sdev, else sbitmap_free(&sb_backup); ret = 0; - blk_mq_unfreeze_queue(sdev->request_queue); + blk_mq_unfreeze_queue(sdev->request_queue, memflags); } return ret; } -- cgit v1.2.3