From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755647Ab2KHNDz (ORCPT ); Thu, 8 Nov 2012 08:03:55 -0500 Received: from mga01.intel.com ([192.55.52.88]:60814 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755622Ab2KHNDx (ORCPT ); Thu, 8 Nov 2012 08:03:53 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.80,737,1344236400"; d="scan'208";a="244102077" From: dragos.tatulea@intel.com To: linux-kernel@vger.kernel.org, linux-mmc@vger.kernel.org, cjb@laptop.org Cc: kirill.shutemov@linux.intel.com, irina.tirdea@intel.com, octavian.purdila@intel.com, tony.luck@intel.com, keescook@chromium.org, dragos.tatulea@gmail.com, Adrian Hunter Subject: [PATCH v2 05/26] block: add panic write Date: Thu, 8 Nov 2012 15:06:03 +0200 Message-Id: <1352379984-18381-6-git-send-email-dragos.tatulea@intel.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1352379984-18381-1-git-send-email-dragos.tatulea@intel.com> References: <1352379984-18381-1-git-send-email-dragos.tatulea@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Adrian Hunter Add a small interface to allow block devices to attempt to write during an oops or panic. Signed-off-by: Adrian Hunter Signed-off-by: Irina Tirdea --- drivers/block/Kconfig | 3 ++ include/linux/blkdev.h | 77 ++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/genhd.h | 3 ++ 3 files changed, 83 insertions(+) diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig index af5b325..922cfd6 100644 --- a/drivers/block/Kconfig +++ b/drivers/block/Kconfig @@ -554,4 +554,7 @@ config BLK_DEV_OOPS See for more information. +config BLK_DEV_PANIC_WRITE + bool + endif # BLK_DEV diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 1756001..bedfaab 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1461,6 +1461,83 @@ static inline bool blk_integrity_is_initialized(struct gendisk *g) #endif /* CONFIG_BLK_DEV_INTEGRITY */ +#ifdef CONFIG_BLK_DEV_PANIC_WRITE + +/** + * struct panic_write_operations - operations to support writing during an oops + * or panic. + * @init: allocate resources + * @cleanup: release resources + * @write: called in an oops or panic context to write data + * @flush: called in an oops or panic context to finish write operations + * + * @write may need resources that cannot be allocated in a panic or oops + * context. @init can be used to allocate those resources in advance. + * @cleanup is called if panic writing becomes disabled. + */ +struct panic_write_operations { + int (*init)(struct block_device *); + void (*cleanup)(struct block_device *); + int (*write)(struct block_device *, sector_t, void *, unsigned long); + int (*flush)(struct block_device *); +}; + +static inline int blk_panic_init(struct block_device *bdev) +{ + if (!bdev->bd_disk->pwops || !bdev->bd_disk->pwops->write) + return -EOPNOTSUPP; + if (bdev->bd_disk->pwops && bdev->bd_disk->pwops->init) + return bdev->bd_disk->pwops->init(bdev); + return 0; +} + +static inline void blk_panic_cleanup(struct block_device *bdev) +{ + if (bdev->bd_disk->pwops && bdev->bd_disk->pwops->cleanup) + bdev->bd_disk->pwops->cleanup(bdev); +} + +static inline int blk_panic_write(struct block_device *bdev, sector_t sect, + void *addr, unsigned long len) +{ + if (!bdev->bd_disk->pwops || !bdev->bd_disk->pwops->write) + return -EOPNOTSUPP; + if (bdev != bdev->bd_contains) + sect += bdev->bd_part->start_sect; + return bdev->bd_disk->pwops->write(bdev, sect, addr, len); +} + +static inline int blk_panic_flush(struct block_device *bdev) +{ + if (bdev->bd_disk->pwops && bdev->bd_disk->pwops->flush) + return bdev->bd_disk->pwops->flush(bdev); + return 0; +} + +#else + +static inline int blk_panic_init(struct block_device *bdev) +{ + return -EOPNOTSUPP; +} + +static inline void blk_panic_cleanup(struct block_device *bdev) +{ +} + +static inline int blk_panic_write(struct block_device *bdev, sector_t sect, + void *addr, unsigned long len) +{ + return -EOPNOTSUPP; +} + +static inline int blk_panic_flush(struct block_device *bdev) +{ + return -EOPNOTSUPP; +} + +#endif /* CONFIG_BLK_DEV_PANIC_WRITE */ + struct block_device_operations { int (*open) (struct block_device *, fmode_t); int (*release) (struct gendisk *, fmode_t); diff --git a/include/linux/genhd.h b/include/linux/genhd.h index 4f440b3..73470af 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -195,6 +195,9 @@ struct gendisk { #ifdef CONFIG_BLK_DEV_INTEGRITY struct blk_integrity *integrity; #endif +#ifdef CONFIG_BLK_DEV_PANIC_WRITE + const struct panic_write_operations *pwops; +#endif int node_id; }; -- 1.7.9.5