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scsi: sd: Mark the disk dead if runtime resume fails in sd_remove()

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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 <hch@lst.de>
Tested-by: Lianqin Hu <hulianqin@vivo.com>
Reported-by: Lianqin Hu <hulianqin@vivo.com>
Closes: https://lore.kernel.org/all/TYUPR06MB6217DD31B1B3CD09E431CC12D2922@TYUPR06MB6217.apcprd06.prod.outlook.com/
Fixes: 6f8191fdf4 ("block: simplify disk shutdown")
Cc: stable@vger.kernel.org
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: John Garry <john.garry@linux.dev>
Link: https://patch.msgid.link/2c0c76d70f0fe197932836b9bcf8496095135d1b.1792446921.git.bvanassche@acm.org
Signed-off-by: Martin K. Petersen (Oracle) <mkp@kernel.org>
This commit is contained in:
Bart Van Assche 2026-10-19 14:55:32 -07:00 committed by Martin K. Petersen (Oracle)
parent eb7aa7fd67
commit 085bb18a0b
1 changed files with 9 additions and 1 deletions
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10
drivers/scsi/sd.c
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@ -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);