From b7617f22a5e607d8018859d271bd20d24bdf0384 Mon Sep 17 00:00:00 2001 From: Hannes Reinecke Date: Tue, 26 Apr 2016 08:06:58 +0200 Subject: [PATCH] sd: get disk reference in sd_check_events() commit eb72d0bb84eee5d0dc3044fd17b75e7101dabb57 upstream. sd_check_events() is called asynchronously, and might race with device removal. So always take a disk reference when processing the event to avoid the device being removed while the event is processed. Signed-off-by: Hannes Reinecke Reviewed-by: Ewan D. Milne Reviewed-by: Bart Van Assche Signed-off-by: Martin K. Petersen Cc: Jinpu Wang Signed-off-by: Jiri Slaby Signed-off-by: Willy Tarreau --- drivers/scsi/sd.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 29699fd10025..bb3c27de71c8 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -1382,11 +1382,15 @@ static int media_not_present(struct scsi_disk *sdkp, **/ static unsigned int sd_check_events(struct gendisk *disk, unsigned int clearing) { - struct scsi_disk *sdkp = scsi_disk(disk); - struct scsi_device *sdp = sdkp->device; + struct scsi_disk *sdkp = scsi_disk_get(disk); + struct scsi_device *sdp; struct scsi_sense_hdr *sshdr = NULL; int retval; + if (!sdkp) + return 0; + + sdp = sdkp->device; SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_check_events\n")); /* @@ -1443,6 +1447,7 @@ out: kfree(sshdr); retval = sdp->changed ? DISK_EVENT_MEDIA_CHANGE : 0; sdp->changed = 0; + scsi_disk_put(sdkp); return retval; }