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OpenCloudOS-Kernel
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OpenCloudOS-Kernel/include/linux/blk-pm.h

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block: Move power management code into a new source file Move the code for runtime power management from blk-core.c into the new source file blk-pm.c. Move the corresponding declarations from <linux/blkdev.h> into <linux/blk-pm.h>. For CONFIG_PM=n, leave out the declarations of the functions that are not used in that mode. This patch not only reduces the number of #ifdefs in the block layer core code but also reduces the size of header file <linux/blkdev.h> and hence should help to reduce the build time of the Linux kernel if CONFIG_PM is not defined. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Jianchao Wang <jianchao.w.wang@oracle.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Johannes Thumshirn <jthumshirn@suse.de> Cc: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-27 05:01:03 +08:00
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _BLK_PM_H_
#define _BLK_PM_H_
struct device;
struct request_queue;
/*
* block layer runtime pm functions
*/
#ifdef CONFIG_PM
extern void blk_pm_runtime_init(struct request_queue *q, struct device *dev);
extern int blk_pre_runtime_suspend(struct request_queue *q);
extern void blk_post_runtime_suspend(struct request_queue *q, int err);
extern void blk_pre_runtime_resume(struct request_queue *q);
scsi: block: pm: Always set request queue runtime active in blk_post_runtime_resume() John Garry reported a deadlock that occurs when trying to access a runtime-suspended SATA device. For obscure reasons, the rescan procedure causes the link to be hard-reset, which disconnects the device. The rescan tries to carry out a runtime resume when accessing the device. scsi_rescan_device() holds the SCSI device lock and won't release it until it can put commands onto the device's block queue. This can't happen until the queue is successfully runtime-resumed or the device is unregistered. But the runtime resume fails because the device is disconnected, and __scsi_remove_device() can't do the unregistration because it can't get the device lock. The best way to resolve this deadlock appears to be to allow the block queue to start running again even after an unsuccessful runtime resume. The idea is that the driver or the SCSI error handler will need to be able to use the queue to resolve the runtime resume failure. This patch removes the err argument to blk_post_runtime_resume() and makes the routine act as though the resume was successful always. This fixes the deadlock. Link: https://lore.kernel.org/r/1639999298-244569-4-git-send-email-chenxiang66@hisilicon.com Fixes: e27829dc92e5 ("scsi: serialize ->rescan against ->remove") Reported-and-tested-by: John Garry <john.garry@huawei.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-12-20 19:21:26 +08:00
extern void blk_post_runtime_resume(struct request_queue *q);
block: Move power management code into a new source file Move the code for runtime power management from blk-core.c into the new source file blk-pm.c. Move the corresponding declarations from <linux/blkdev.h> into <linux/blk-pm.h>. For CONFIG_PM=n, leave out the declarations of the functions that are not used in that mode. This patch not only reduces the number of #ifdefs in the block layer core code but also reduces the size of header file <linux/blkdev.h> and hence should help to reduce the build time of the Linux kernel if CONFIG_PM is not defined. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Jianchao Wang <jianchao.w.wang@oracle.com> Cc: Hannes Reinecke <hare@suse.com> Cc: Johannes Thumshirn <jthumshirn@suse.de> Cc: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-09-27 05:01:03 +08:00
extern void blk_set_runtime_active(struct request_queue *q);
#else
static inline void blk_pm_runtime_init(struct request_queue *q,
struct device *dev) {}
#endif
#endif /* _BLK_PM_H_ */