xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

block: add an API for Persistent Reservations

Browse Source 
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 <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Christoph Hellwig
2015-10-15 14:10:48 +02:00
committed by Jens Axboe
parent d8e4bb8103
commit bbd3e06436
5 changed files with 290 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

48
include/uapi/linux/pr.h Normal file
View File

@@ -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 */