From 085bb18a0b91007f04ddca13af30277c78040157 Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Mon, 19 Oct 2026 14:55:32 -0700 Subject: [PATCH] scsi: sd: Mark the disk dead if runtime resume fails in sd_remove() If a SCSI disk is unplugged while runtime suspended, its request queue is still in the pm-only state when sd_remove() is called. The runtime resume attempted by scsi_autopm_get_device() fails because the parent device, e.g. a USB device in the USB_STATE_NOTATTACHED state, cannot be resumed. Hence, sdev_runtime_resume() is not called and the pm-only state is not cleared. Next, del_gendisk() calls blk_report_disk_dead(disk, false), which calls sync_filesystem(). Any bio submitted by the filesystem waits forever in __bio_queue_enter() because the queue will never leave the pm-only state and because GD_DEAD has not yet been set: __bio_queue_enter+0xb8/0x174 blk_mq_submit_bio+0x640/0x7e4 [ ... ] exfat_sync_fs+0xa4/0xe0 sync_filesystem+0xa8/0xdc fs_bdev_mark_dead+0x30/0x88 bdev_mark_dead+0x54/0xc4 blk_report_disk_dead+0x8c/0xd4 del_gendisk+0xa0/0x2f8 sd_remove+0x30/0x60 [ ... ] scsi_remove_host+0x88/0x18c usb_stor_disconnect+0x68/0xf4 Fix this hang by calling blk_mark_disk_dead() if runtime resume fails. This sets GD_DEAD, tells the filesystem that the disk has been removed without attempting to sync it, and wakes up any bios that are waiting in __bio_queue_enter(). Syncing the filesystem is not possible anyway if runtime resume failed, so no data is lost that could otherwise have been written. If runtime resume succeeds, behavior is not changed. Please note that this patch converts temporary runtime resume failures into permanent failures. Before this patch, if runtime resume fails temporarily, a filesytem sync would be postponed until a later resume succeeds. Cc: Christoph Hellwig Tested-by: Lianqin Hu Reported-by: Lianqin Hu Closes: https://lore.kernel.org/all/TYUPR06MB6217DD31B1B3CD09E431CC12D2922@TYUPR06MB6217.apcprd06.prod.outlook.com/ Fixes: 6f8191fdf41d ("block: simplify disk shutdown") Cc: stable@vger.kernel.org Signed-off-by: Bart Van Assche Reviewed-by: John Garry Link: https://patch.msgid.link/2c0c76d70f0fe197932836b9bcf8496095135d1b.1792446921.git.bvanassche@acm.org Signed-off-by: Martin K. Petersen (Oracle) --- drivers/scsi/sd.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index b0d2542fd317..dc45df819c42 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -4268,7 +4268,15 @@ static void sd_remove(struct scsi_device *sdp) struct device *dev = &sdp->sdev_gendev; struct scsi_disk *sdkp = dev_get_drvdata(dev); - scsi_autopm_get_device(sdkp->device); + /* + * If runtime resume fails, e.g. because the device was unplugged + * while runtime suspended, the request queue stays in the pm-only + * state and any I/O submitted by del_gendisk(), e.g. from + * sync_filesystem(), would wait forever in __bio_queue_enter(). + * Prevent this by marking the disk dead. + */ + if (scsi_autopm_get_device(sdkp->device) < 0) + blk_mark_disk_dead(sdkp->disk); device_del(&sdkp->disk_dev); del_gendisk(sdkp->disk);