From 996e509bbc956d60f761dc955f5c5131e9a8fb13 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 29 Oct 2020 15:58:31 +0100 Subject: [PATCH] sd: use __register_blkdev to avoid a modprobe for an unregistered dev_t Switch from using blk_register_region to the probe callback passed to __register_blkdev to disable the request_module call for an unclaimed dev_t in the SD majors. Signed-off-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Acked-by: Martin K. Petersen Signed-off-by: Jens Axboe --- drivers/scsi/sd.c | 19 +++++-------------- 1 file changed, 5 insertions(+), 14 deletions(-) diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 656bcf4940d6..106a9cda0eb7 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -630,13 +630,11 @@ static struct scsi_driver sd_template = { }; /* - * Dummy kobj_map->probe function. - * The default ->probe function will call modprobe, which is - * pointless as this module is already loaded. + * Don't request a new module, as that could deadlock in multipath + * environment. */ -static struct kobject *sd_default_probe(dev_t devt, int *partno, void *data) +static void sd_default_probe(dev_t devt) { - return NULL; } /* @@ -3528,9 +3526,6 @@ static int sd_remove(struct device *dev) free_opal_dev(sdkp->opal_dev); - blk_register_region(devt, SD_MINORS, NULL, - sd_default_probe, NULL, NULL); - mutex_lock(&sd_ref_mutex); dev_set_drvdata(dev, NULL); put_device(&sdkp->dev); @@ -3720,11 +3715,9 @@ static int __init init_sd(void) SCSI_LOG_HLQUEUE(3, printk("init_sd: sd driver entry point\n")); for (i = 0; i < SD_MAJORS; i++) { - if (register_blkdev(sd_major(i), "sd") != 0) + if (__register_blkdev(sd_major(i), "sd", sd_default_probe)) continue; majors++; - blk_register_region(sd_major(i), SD_MINORS, NULL, - sd_default_probe, NULL, NULL); } if (!majors) @@ -3797,10 +3790,8 @@ static void __exit exit_sd(void) class_unregister(&sd_disk_class); - for (i = 0; i < SD_MAJORS; i++) { - blk_unregister_region(sd_major(i), SD_MINORS); + for (i = 0; i < SD_MAJORS; i++) unregister_blkdev(sd_major(i), "sd"); - } } module_init(init_sd); -- 2.11.0