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.
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| 1 | #ifndef _UAPI_PR_H | ||
| 2 | #define _UAPI_PR_H | ||
| 3 | |||
| 4 | enum pr_type { | ||
| 5 | PR_WRITE_EXCLUSIVE = 1, | ||
| 6 | PR_EXCLUSIVE_ACCESS = 2, | ||
| 7 | PR_WRITE_EXCLUSIVE_REG_ONLY = 3, | ||
| 8 | PR_EXCLUSIVE_ACCESS_REG_ONLY = 4, | ||
| 9 | PR_WRITE_EXCLUSIVE_ALL_REGS = 5, | ||
| 10 | PR_EXCLUSIVE_ACCESS_ALL_REGS = 6, | ||
| 11 | }; | ||
| 12 | |||
| 13 | struct pr_reservation { | ||
| 14 | __u64 key; | ||
| 15 | __u32 type; | ||
| 16 | __u32 flags; | ||
| 17 | }; | ||
| 18 | |||
| 19 | struct pr_registration { | ||
| 20 | __u64 old_key; | ||
| 21 | __u64 new_key; | ||
| 22 | __u32 flags; | ||
| 23 | __u32 __pad; | ||
| 24 | }; | ||
| 25 | |||
| 26 | struct pr_preempt { | ||
| 27 | __u64 old_key; | ||
| 28 | __u64 new_key; | ||
| 29 | __u32 type; | ||
| 30 | __u32 flags; | ||
| 31 | }; | ||
| 32 | |||
| 33 | struct pr_clear { | ||
| 34 | __u64 key; | ||
| 35 | __u32 flags; | ||
| 36 | __u32 __pad; | ||
| 37 | }; | ||
| 38 | |||
| 39 | #define PR_FL_IGNORE_KEY (1 << 0) /* ignore existing key */ | ||
| 40 | |||
| 41 | #define IOC_PR_REGISTER _IOW('p', 200, struct pr_registration) | ||
| 42 | #define IOC_PR_RESERVE _IOW('p', 201, struct pr_reservation) | ||
| 43 | #define IOC_PR_RELEASE _IOW('p', 202, struct pr_reservation) | ||
| 44 | #define IOC_PR_PREEMPT _IOW('p', 203, struct pr_preempt) | ||
| 45 | #define IOC_PR_PREEMPT_ABORT _IOW('p', 204, struct pr_preempt) | ||
| 46 | #define IOC_PR_CLEAR _IOW('p', 205, struct pr_clear) | ||
| 47 | |||
| 48 | #endif /* _UAPI_PR_H */ | ||