Commit 2fd4f4cb authored by Alexander Strakh's avatar Alexander Strakh Committed by james toy

Driver scsi_lib.c might sleep in atomic context, because it calls

scsi_device_put under spin_lock_irqsave.

drivers/scsi/scsi_lib.c:356:
	spin_lock_irqsave(shost->host_lock, flags);
	scsi_device_put(sdev);
Path to might_sleep macro from scsi_device_put:
1. scsi_device_put calls put_device at ./drivers/scsi/scsi.c:1111
2. put_device calls kobject_put at ./drivers/base/core.c:1038
3. kobject_put calls kref_put at ./lib/kobject.c
4. kref_put may call callback function kobject_release at ./lib/kref.c if
refcount becomes zero, which might_sleep because it calls user event. Details:
	4.1 kobject_cleanup calls kobject_uevent at ./lib/kobject.c:555
	4.2 kobject_uevent calls kobject_uevent_env at  ./lib/kobject_uevent.c:282
	4.3 kobject_uevent_env calls call_usermodehelper_exec at
./include/linux/kmod.h:83
	4.4 call_usermodehelper_exec calls wait_for_completion at
./kernel/kmod.c:481
	4.5 wait_for_completion calls wait_for_common at ./kernel/sched.c:5710
	4.5 wait_for_common calls might_sleep at ./kernels/sched.c:5692

Found by Linux Driver Verification project.

Delete wrong sleeping function calls.
Signed-off-by: default avatarAlexander Strakh <strakh@ispras.ru>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 33482a49
...@@ -353,9 +353,9 @@ static void scsi_single_lun_run(struct scsi_device *current_sdev) ...@@ -353,9 +353,9 @@ static void scsi_single_lun_run(struct scsi_device *current_sdev)
spin_unlock_irqrestore(shost->host_lock, flags); spin_unlock_irqrestore(shost->host_lock, flags);
blk_run_queue(sdev->request_queue); blk_run_queue(sdev->request_queue);
spin_lock_irqsave(shost->host_lock, flags);
scsi_device_put(sdev); scsi_device_put(sdev);
spin_lock_irqsave(shost->host_lock, flags);
} }
out: out:
spin_unlock_irqrestore(shost->host_lock, flags); spin_unlock_irqrestore(shost->host_lock, flags);
......
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