From 22be093ffb403a1c474037939ca9b88b1ee39f77 Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Thu, 23 Sep 2010 15:01:41 +0200 Subject: readahead: implement minimal readahead logic based on fanotify(), mincore() and readahead() --- src/linux/fanotify.h | 98 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 98 insertions(+) create mode 100644 src/linux/fanotify.h (limited to 'src/linux') diff --git a/src/linux/fanotify.h b/src/linux/fanotify.h new file mode 100644 index 0000000000..63531a6b4d --- /dev/null +++ b/src/linux/fanotify.h @@ -0,0 +1,98 @@ +#ifndef _LINUX_FANOTIFY_H +#define _LINUX_FANOTIFY_H + +#include + +/* the following events that user-space can register for */ +#define FAN_ACCESS 0x00000001 /* File was accessed */ +#define FAN_MODIFY 0x00000002 /* File was modified */ +#define FAN_CLOSE_WRITE 0x00000008 /* Unwrittable file closed */ +#define FAN_CLOSE_NOWRITE 0x00000010 /* Writtable file closed */ +#define FAN_OPEN 0x00000020 /* File was opened */ + +#define FAN_EVENT_ON_CHILD 0x08000000 /* interested in child events */ + +/* FIXME currently Q's have no limit.... */ +#define FAN_Q_OVERFLOW 0x00004000 /* Event queued overflowed */ + +#define FAN_OPEN_PERM 0x00010000 /* File open in perm check */ +#define FAN_ACCESS_PERM 0x00020000 /* File accessed in perm check */ + +/* helper events */ +#define FAN_CLOSE (FAN_CLOSE_WRITE | FAN_CLOSE_NOWRITE) /* close */ + +/* flags used for fanotify_init() */ +#define FAN_CLOEXEC 0x00000001 +#define FAN_NONBLOCK 0x00000002 + +#define FAN_ALL_INIT_FLAGS (FAN_CLOEXEC | FAN_NONBLOCK) + +/* flags used for fanotify_modify_mark() */ +#define FAN_MARK_ADD 0x00000001 +#define FAN_MARK_REMOVE 0x00000002 +#define FAN_MARK_DONT_FOLLOW 0x00000004 +#define FAN_MARK_ONLYDIR 0x00000008 +#define FAN_MARK_MOUNT 0x00000010 +#define FAN_MARK_IGNORED_MASK 0x00000020 +#define FAN_MARK_IGNORED_SURV_MODIFY 0x00000040 +#define FAN_MARK_FLUSH 0x00000080 + +#define FAN_ALL_MARK_FLAGS (FAN_MARK_ADD |\ + FAN_MARK_REMOVE |\ + FAN_MARK_DONT_FOLLOW |\ + FAN_MARK_ONLYDIR |\ + FAN_MARK_MOUNT |\ + FAN_MARK_IGNORED_MASK |\ + FAN_MARK_IGNORED_SURV_MODIFY) + +/* + * All of the events - we build the list by hand so that we can add flags in + * the future and not break backward compatibility. Apps will get only the + * events that they originally wanted. Be sure to add new events here! + */ +#define FAN_ALL_EVENTS (FAN_ACCESS |\ + FAN_MODIFY |\ + FAN_CLOSE |\ + FAN_OPEN) + +/* + * All events which require a permission response from userspace + */ +#define FAN_ALL_PERM_EVENTS (FAN_OPEN_PERM |\ + FAN_ACCESS_PERM) + +#define FAN_ALL_OUTGOING_EVENTS (FAN_ALL_EVENTS |\ + FAN_ALL_PERM_EVENTS |\ + FAN_Q_OVERFLOW) + +#define FANOTIFY_METADATA_VERSION 2 + +struct fanotify_event_metadata { + __u32 event_len; + __u32 vers; + __u64 mask; + __s32 fd; + __s32 pid; +} __attribute__ ((packed)); + +struct fanotify_response { + __s32 fd; + __u32 response; +} __attribute__ ((packed)); + +/* Legit userspace responses to a _PERM event */ +#define FAN_ALLOW 0x01 +#define FAN_DENY 0x02 + +/* Helper functions to deal with fanotify_event_metadata buffers */ +#define FAN_EVENT_METADATA_LEN (sizeof(struct fanotify_event_metadata)) + +#define FAN_EVENT_NEXT(meta, len) ((len) -= (meta)->event_len, \ + (struct fanotify_event_metadata*)(((char *)(meta)) + \ + (meta)->event_len)) + +#define FAN_EVENT_OK(meta, len) ((long)(len) >= (long)FAN_EVENT_METADATA_LEN && \ + (long)(meta)->event_len >= (long)FAN_EVENT_METADATA_LEN && \ + (long)(meta)->event_len <= (long)(len)) + +#endif /* _LINUX_FANOTIFY_H */ -- cgit v1.2.3-54-g00ecf