fanotify: deprecate uapi FAN_ALL_* constants

We do not want to add new bits to the FAN_ALL_* uapi constants
because they have been exposed to userspace.  If there are programs
out there using these constants, those programs could break if
re-compiled with modified FAN_ALL_* constants and run on an old kernel.

We deprecate the uapi constants FAN_ALL_* and define new FANOTIFY_*
constants for internal use to replace them. New feature bits will be
added only to the new constants.

Cc: <linux-api@vger.kernel.org>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
This commit is contained in:
Amir Goldstein 2018-10-04 00:25:35 +03:00 committed by Jan Kara
parent a72fd224e3
commit 23c9deeb32
5 changed files with 71 additions and 24 deletions

View file

@ -7,4 +7,51 @@
#define FAN_GROUP_FLAG(group, flag) \
((group)->fanotify_data.flags & (flag))
/*
* Flags allowed to be passed from/to userspace.
*
* We intentionally do not add new bits to the old FAN_ALL_* constants, because
* they are uapi exposed constants. If there are programs out there using
* these constant, the programs may break if re-compiled with new uapi headers
* and then run on an old kernel.
*/
#define FANOTIFY_CLASS_BITS (FAN_CLASS_NOTIF | FAN_CLASS_CONTENT | \
FAN_CLASS_PRE_CONTENT)
#define FANOTIFY_INIT_FLAGS (FANOTIFY_CLASS_BITS | \
FAN_CLOEXEC | FAN_NONBLOCK | \
FAN_UNLIMITED_QUEUE | FAN_UNLIMITED_MARKS)
#define FANOTIFY_MARK_TYPE_BITS (FAN_MARK_INODE | FAN_MARK_MOUNT | \
FAN_MARK_FILESYSTEM)
#define FANOTIFY_MARK_FLAGS (FANOTIFY_MARK_TYPE_BITS | \
FAN_MARK_ADD | \
FAN_MARK_REMOVE | \
FAN_MARK_DONT_FOLLOW | \
FAN_MARK_ONLYDIR | \
FAN_MARK_IGNORED_MASK | \
FAN_MARK_IGNORED_SURV_MODIFY | \
FAN_MARK_FLUSH)
/* Events that user can request to be notified on */
#define FANOTIFY_EVENTS (FAN_ACCESS | FAN_MODIFY | \
FAN_CLOSE | FAN_OPEN)
/* Events that require a permission response from user */
#define FANOTIFY_PERM_EVENTS (FAN_OPEN_PERM | FAN_ACCESS_PERM)
/* Events that may be reported to user */
#define FANOTIFY_OUTGOING_EVENTS (FANOTIFY_EVENTS | \
FANOTIFY_PERM_EVENTS | \
FAN_Q_OVERFLOW)
/* Do not use these old uapi constants internally */
#undef FAN_ALL_CLASS_BITS
#undef FAN_ALL_INIT_FLAGS
#undef FAN_ALL_MARK_FLAGS
#undef FAN_ALL_EVENTS
#undef FAN_ALL_PERM_EVENTS
#undef FAN_ALL_OUTGOING_EVENTS
#endif /* _LINUX_FANOTIFY_H */