1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ 2 #ifndef _UAPI_LINUX_WATCH_QUEUE_H 3 #define _UAPI_LINUX_WATCH_QUEUE_H 4 5 #include <linux/types.h> 6 #include <linux/fcntl.h> 7 8 #define O_NOTIFICATION_PIPE O_EXCL /* Parameter to pipe2() selecting notification pipe */ 9 10 enum watch_notification_type { 11 WATCH_TYPE_META = 0, /* Special record */ 12 WATCH_TYPE__NR = 1 13 }; 14 15 enum watch_meta_notification_subtype { 16 WATCH_META_REMOVAL_NOTIFICATION = 0, /* Watched object was removed */ 17 WATCH_META_LOSS_NOTIFICATION = 1, /* Data loss occurred */ 18 }; 19 20 /* 21 * Notification record header. This is aligned to 64-bits so that subclasses 22 * can contain __u64 fields. 23 */ 24 struct watch_notification { 25 __u32 type:24; /* enum watch_notification_type */ 26 __u32 subtype:8; /* Type-specific subtype (filterable) */ 27 __u32 info; 28 #define WATCH_INFO_LENGTH 0x0000007f /* Length of record */ 29 #define WATCH_INFO_LENGTH__SHIFT 0 30 #define WATCH_INFO_ID 0x0000ff00 /* ID of watchpoint */ 31 #define WATCH_INFO_ID__SHIFT 8 32 #define WATCH_INFO_TYPE_INFO 0xffff0000 /* Type-specific info */ 33 #define WATCH_INFO_TYPE_INFO__SHIFT 16 34 #define WATCH_INFO_FLAG_0 0x00010000 /* Type-specific info, flag bit 0 */ 35 #define WATCH_INFO_FLAG_1 0x00020000 /* ... */ 36 #define WATCH_INFO_FLAG_2 0x00040000 37 #define WATCH_INFO_FLAG_3 0x00080000 38 #define WATCH_INFO_FLAG_4 0x00100000 39 #define WATCH_INFO_FLAG_5 0x00200000 40 #define WATCH_INFO_FLAG_6 0x00400000 41 #define WATCH_INFO_FLAG_7 0x00800000 42 }; 43 44 45 /* 46 * Extended watch removal notification. This is used optionally if the type 47 * wants to indicate an identifier for the object being watched, if there is 48 * such. This can be distinguished by the length. 49 * 50 * type -> WATCH_TYPE_META 51 * subtype -> WATCH_META_REMOVAL_NOTIFICATION 52 */ 53 struct watch_notification_removal { 54 struct watch_notification watch; 55 __u64 id; /* Type-dependent identifier */ 56 }; 57 58 #endif /* _UAPI_LINUX_WATCH_QUEUE_H */ 59