From bbd3e064362e5057cc4799ba2e4d68c7593e490b Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 15 Oct 2015 14:10:48 +0200 Subject: block: add an API for Persistent Reservations This commits adds a driver API and ioctls for controlling Persistent Reservations s/genericly/generically/ at the block layer. Persistent Reservations are supported by SCSI and NVMe and allow controlling who gets access to a device in a shared storage setup. Note that we add a pr_ops structure to struct block_device_operations instead of adding the members directly to avoid bloating all instances of devices that will never support Persistent Reservations. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 2 ++ include/linux/pr.h | 18 ++++++++++++++++++ include/uapi/linux/pr.h | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 68 insertions(+) create mode 100644 include/linux/pr.h create mode 100644 include/uapi/linux/pr.h (limited to 'include') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 19c2e947d4d1..fe25da05e823 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -35,6 +35,7 @@ struct sg_io_hdr; struct bsg_job; struct blkcg_gq; struct blk_flush_queue; +struct pr_ops; #define BLKDEV_MIN_RQ 4 #define BLKDEV_MAX_RQ 128 /* Default maximum */ @@ -1633,6 +1634,7 @@ struct block_device_operations { /* this callback is with swap_lock and sometimes page table lock held */ void (*swap_slot_free_notify) (struct block_device *, unsigned long); struct module *owner; + const struct pr_ops *pr_ops; }; extern int __blkdev_driver_ioctl(struct block_device *, fmode_t, unsigned int, diff --git a/include/linux/pr.h b/include/linux/pr.h new file mode 100644 index 000000000000..65c01c10b335 --- /dev/null +++ b/include/linux/pr.h @@ -0,0 +1,18 @@ +#ifndef LINUX_PR_H +#define LINUX_PR_H + +#include + +struct pr_ops { + int (*pr_register)(struct block_device *bdev, u64 old_key, u64 new_key, + u32 flags); + int (*pr_reserve)(struct block_device *bdev, u64 key, + enum pr_type type, u32 flags); + int (*pr_release)(struct block_device *bdev, u64 key, + enum pr_type type); + int (*pr_preempt)(struct block_device *bdev, u64 old_key, u64 new_key, + enum pr_type type, bool abort); + int (*pr_clear)(struct block_device *bdev, u64 key); +}; + +#endif /* LINUX_PR_H */ diff --git a/include/uapi/linux/pr.h b/include/uapi/linux/pr.h new file mode 100644 index 000000000000..57d7c0f916b6 --- /dev/null +++ b/include/uapi/linux/pr.h @@ -0,0 +1,48 @@ +#ifndef _UAPI_PR_H +#define _UAPI_PR_H + +enum pr_type { + PR_WRITE_EXCLUSIVE = 1, + PR_EXCLUSIVE_ACCESS = 2, + PR_WRITE_EXCLUSIVE_REG_ONLY = 3, + PR_EXCLUSIVE_ACCESS_REG_ONLY = 4, + PR_WRITE_EXCLUSIVE_ALL_REGS = 5, + PR_EXCLUSIVE_ACCESS_ALL_REGS = 6, +}; + +struct pr_reservation { + __u64 key; + __u32 type; + __u32 flags; +}; + +struct pr_registration { + __u64 old_key; + __u64 new_key; + __u32 flags; + __u32 __pad; +}; + +struct pr_preempt { + __u64 old_key; + __u64 new_key; + __u32 type; + __u32 flags; +}; + +struct pr_clear { + __u64 key; + __u32 flags; + __u32 __pad; +}; + +#define PR_FL_IGNORE_KEY (1 << 0) /* ignore existing key */ + +#define IOC_PR_REGISTER _IOW('p', 200, struct pr_registration) +#define IOC_PR_RESERVE _IOW('p', 201, struct pr_reservation) +#define IOC_PR_RELEASE _IOW('p', 202, struct pr_reservation) +#define IOC_PR_PREEMPT _IOW('p', 203, struct pr_preempt) +#define IOC_PR_PREEMPT_ABORT _IOW('p', 204, struct pr_preempt) +#define IOC_PR_CLEAR _IOW('p', 205, struct pr_clear) + +#endif /* _UAPI_PR_H */ -- cgit v1.2.3