The patch titled
scsi_lib.c: avoid calling scsi_device_put() from under ->host_lock
has been removed from the -mm tree. Its filename was
scsi_libc-avoid-calling-scsi_device_put-from-under-host_lock.patch
This patch was dropped because it was nacked
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: scsi_lib.c: avoid calling scsi_device_put() from under ->host_lock
From: Alexander Strakh <strakh@xxxxxxxxx>
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: Alexander Strakh <strakh@xxxxxxxxx>
Cc: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>
Cc: Jens Axboe <jens.axboe@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/scsi/scsi_lib.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff -puN drivers/scsi/scsi_lib.c~scsi_libc-avoid-calling-scsi_device_put-from-under-host_lock drivers/scsi/scsi_lib.c
--- a/drivers/scsi/scsi_lib.c~scsi_libc-avoid-calling-scsi_device_put-from-under-host_lock
+++ a/drivers/scsi/scsi_lib.c
@@ -353,9 +353,9 @@ static void scsi_single_lun_run(struct s
spin_unlock_irqrestore(shost->host_lock, flags);
blk_run_queue(sdev->request_queue);
- spin_lock_irqsave(shost->host_lock, flags);
scsi_device_put(sdev);
+ spin_lock_irqsave(shost->host_lock, flags);
}
out:
spin_unlock_irqrestore(shost->host_lock, flags);
_
Patches currently in -mm which might be from strakh@xxxxxxxxx are
scsi_libc-avoid-calling-scsi_device_put-from-under-host_lock.patch
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