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 */ | |