3.2-stable review patch. If anyone has any objections, please let me know.
------------------ From: Bart Van Assche <bvanass...@acm.org> commit 67bd94130015c507011af37858989b199c52e1de upstream. Use blk_queue_dead() to test whether the queue is dead instead of !sdev. Since scsi_prep_fn() may be invoked concurrently with __scsi_remove_device(), keep the queuedata (sdev) pointer in __scsi_remove_device(). This patch fixes a kernel oops that can be triggered by USB device removal. See also http://www.spinics.net/lists/linux-scsi/msg56254.html. Other changes included in this patch: - Swap the blk_cleanup_queue() and kfree() calls in scsi_host_dev_release() to make that code easier to grasp. - Remove the queue dead check from scsi_run_queue() since the queue state can change anyway at any point in that function where the queue lock is not held. - Remove the queue dead check from the start of scsi_request_fn() since it is redundant with the scsi_device_online() check. Reported-by: Jun'ichi Nomura <j-nom...@ce.jp.nec.com> Signed-off-by: Bart Van Assche <bvanass...@acm.org> Reviewed-by: Mike Christie <micha...@cs.wisc.edu> Reviewed-by: Tejun Heo <t...@kernel.org> Signed-off-by: James Bottomley <jbottom...@parallels.com> Signed-off-by: Ben Hutchings <b...@decadent.org.uk> --- drivers/scsi/hosts.c | 7 ++++--- drivers/scsi/scsi_lib.c | 32 ++++---------------------------- drivers/scsi/scsi_priv.h | 1 - drivers/scsi/scsi_sysfs.c | 5 +---- 4 files changed, 9 insertions(+), 36 deletions(-) diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c index 2b6a03d..593085a 100644 --- a/drivers/scsi/hosts.c +++ b/drivers/scsi/hosts.c @@ -290,6 +290,7 @@ static void scsi_host_dev_release(struct device *dev) struct Scsi_Host *shost = dev_to_shost(dev); struct device *parent = dev->parent; struct request_queue *q; + void *queuedata; scsi_proc_hostdir_rm(shost->hostt); @@ -299,9 +300,9 @@ static void scsi_host_dev_release(struct device *dev) destroy_workqueue(shost->work_q); q = shost->uspace_req_q; if (q) { - kfree(q->queuedata); - q->queuedata = NULL; - scsi_free_queue(q); + queuedata = q->queuedata; + blk_cleanup_queue(q); + kfree(queuedata); } scsi_destroy_command_freelist(shost); diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 9f00c12..4acf5c2 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -406,10 +406,6 @@ static void scsi_run_queue(struct request_queue *q) LIST_HEAD(starved_list); unsigned long flags; - /* if the device is dead, sdev will be NULL, so no queue to run */ - if (!sdev) - return; - shost = sdev->host; if (scsi_target(sdev)->single_lun) scsi_single_lun_run(sdev); @@ -1371,16 +1367,16 @@ static inline int scsi_host_queue_ready(struct request_queue *q, * may be changed after request stacking drivers call the function, * regardless of taking lock or not. * - * When scsi can't dispatch I/Os anymore and needs to kill I/Os - * (e.g. !sdev), scsi needs to return 'not busy'. - * Otherwise, request stacking drivers may hold requests forever. + * When scsi can't dispatch I/Os anymore and needs to kill I/Os scsi + * needs to return 'not busy'. Otherwise, request stacking drivers + * may hold requests forever. */ static int scsi_lld_busy(struct request_queue *q) { struct scsi_device *sdev = q->queuedata; struct Scsi_Host *shost; - if (!sdev) + if (blk_queue_dead(q)) return 0; shost = sdev->host; @@ -1491,12 +1487,6 @@ static void scsi_request_fn(struct request_queue *q) struct scsi_cmnd *cmd; struct request *req; - if (!sdev) { - while ((req = blk_peek_request(q)) != NULL) - scsi_kill_request(req, q); - return; - } - if(!get_device(&sdev->sdev_gendev)) /* We must be tearing the block queue down already */ return; @@ -1698,20 +1688,6 @@ struct request_queue *scsi_alloc_queue(struct scsi_device *sdev) return q; } -void scsi_free_queue(struct request_queue *q) -{ - unsigned long flags; - - WARN_ON(q->queuedata); - - /* cause scsi_request_fn() to kill all non-finished requests */ - spin_lock_irqsave(q->queue_lock, flags); - q->request_fn(q); - spin_unlock_irqrestore(q->queue_lock, flags); - - blk_cleanup_queue(q); -} - /* * Function: scsi_block_requests() * diff --git a/drivers/scsi/scsi_priv.h b/drivers/scsi/scsi_priv.h index cbfe5df..291db6e 100644 --- a/drivers/scsi/scsi_priv.h +++ b/drivers/scsi/scsi_priv.h @@ -85,7 +85,6 @@ extern void scsi_next_command(struct scsi_cmnd *cmd); extern void scsi_io_completion(struct scsi_cmnd *, unsigned int); extern void scsi_run_host_queues(struct Scsi_Host *shost); extern struct request_queue *scsi_alloc_queue(struct scsi_device *sdev); -extern void scsi_free_queue(struct request_queue *q); extern int scsi_init_queue(void); extern void scsi_exit_queue(void); struct request_queue; diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c index 5747478..9aa578a 100644 --- a/drivers/scsi/scsi_sysfs.c +++ b/drivers/scsi/scsi_sysfs.c @@ -972,11 +972,8 @@ void __scsi_remove_device(struct scsi_device *sdev) sdev->host->hostt->slave_destroy(sdev); transport_destroy_device(dev); - /* cause the request function to reject all I/O requests */ - sdev->request_queue->queuedata = NULL; - /* Freeing the queue signals to block that we're done */ - scsi_free_queue(sdev->request_queue); + blk_cleanup_queue(sdev->request_queue); put_device(dev); } -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
