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* [PATCH][RFC] fanotify: deprecate uapi FAN_ALL_* constants
@ 2018-09-27 22:01 Amir Goldstein
  2018-10-02 15:56 ` Jan Kara
  0 siblings, 1 reply; 4+ messages in thread
From: Amir Goldstein @ 2018-09-27 22:01 UTC (permalink / raw)
  To: Jan Kara; +Cc: linux-fsdevel, linux-api

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 FAN_USER_*
constants for internal use to replace them. New feature bits will be
added only to the new constants.

Use high bits for kernel internal flag FAN_MARK_ONDIR and add
BUILD_BUG_ON to avoid collision between uapi and kernel internal
mark flags.

Cc: <linux-api@vger.kernel.org>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
---

Jan,

I have rebased the API changes (FAN_MARK_FILESYSTEM and
FAN_EVENT_INFO_TID) on top of commit 60f7ed8c7c4d ("fsnotify: send path
type events to group with super block marks") from your 'fsnotify'
branch starting with this change. The work is available on my branch
fanotify_api-v3 [1].

The end result is that no existing uapi constant are modified and
new bit group definitions (FAN_MARK_TYPE_MASK, FAN_EVENT_INFO_FLAGS)
are not repeating past mistake and not exposed in uapi.

If you agree with this approach and I will post the rest of the series.

Thanks,
Amir.

[1] https://github.com/amir73il/linux/commits/fanotify_api-v3

 fs/notify/fanotify/fanotify.c      |  6 ++--
 fs/notify/fanotify/fanotify.h      |  2 +-
 fs/notify/fanotify/fanotify_user.c | 20 ++++++-----
 include/linux/fanotify.h           | 54 ++++++++++++++++++++++++++++--
 include/uapi/linux/fanotify.h      | 12 ++++---
 5 files changed, 74 insertions(+), 20 deletions(-)

diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
index 94b52157bf8d..e5a3c69848e4 100644
--- a/fs/notify/fanotify/fanotify.c
+++ b/fs/notify/fanotify/fanotify.c
@@ -131,8 +131,8 @@ static bool fanotify_should_send_event(struct fsnotify_iter_info *iter_info,
 	    !(marks_mask & FS_ISDIR & ~marks_ignored_mask))
 		return false;
 
-	if (event_mask & FAN_ALL_OUTGOING_EVENTS & marks_mask &
-				 ~marks_ignored_mask)
+	if (event_mask & FAN_USER_OUTGOING_EVENTS &
+	    marks_mask & ~marks_ignored_mask)
 		return true;
 
 	return false;
@@ -236,7 +236,7 @@ static int fanotify_handle_event(struct fsnotify_group *group,
 	ret = fsnotify_add_event(group, fsn_event, fanotify_merge);
 	if (ret) {
 		/* Permission events shouldn't be merged */
-		BUG_ON(ret == 1 && mask & FAN_ALL_PERM_EVENTS);
+		BUG_ON(ret == 1 && mask & FAN_USER_PERM_EVENTS);
 		/* Our event wasn't used in the end. Free it. */
 		fsnotify_destroy_event(group, fsn_event);
 
diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h
index 8609ba06f474..2686a34319ca 100644
--- a/fs/notify/fanotify/fanotify.h
+++ b/fs/notify/fanotify/fanotify.h
@@ -44,7 +44,7 @@ FANOTIFY_PE(struct fsnotify_event *fse)
 static inline bool fanotify_is_perm_event(u32 mask)
 {
 	return IS_ENABLED(CONFIG_FANOTIFY_ACCESS_PERMISSIONS) &&
-		mask & FAN_ALL_PERM_EVENTS;
+		mask & FAN_USER_PERM_EVENTS;
 }
 
 static inline struct fanotify_event_info *FANOTIFY_E(struct fsnotify_event *fse)
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index 69054886915b..5ede3488ec93 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -131,7 +131,7 @@ static int fill_event_metadata(struct fsnotify_group *group,
 	metadata->metadata_len = FAN_EVENT_METADATA_LEN;
 	metadata->vers = FANOTIFY_METADATA_VERSION;
 	metadata->reserved = 0;
-	metadata->mask = fsn_event->mask & FAN_ALL_OUTGOING_EVENTS;
+	metadata->mask = fsn_event->mask & FAN_USER_OUTGOING_EVENTS;
 	metadata->pid = pid_vnr(event->tgid);
 	if (unlikely(fsn_event->mask & FAN_Q_OVERFLOW))
 		metadata->fd = FAN_NOFD;
@@ -395,7 +395,7 @@ static int fanotify_release(struct inode *ignored, struct file *file)
 	 */
 	while (!fsnotify_notify_queue_is_empty(group)) {
 		fsn_event = fsnotify_remove_first_event(group);
-		if (!(fsn_event->mask & FAN_ALL_PERM_EVENTS)) {
+		if (!(fsn_event->mask & FAN_USER_PERM_EVENTS)) {
 			spin_unlock(&group->notification_lock);
 			fsnotify_destroy_event(group, fsn_event);
 			spin_lock(&group->notification_lock);
@@ -693,9 +693,9 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
 		return -EPERM;
 
 #ifdef CONFIG_AUDITSYSCALL
-	if (flags & ~(FAN_ALL_INIT_FLAGS | FAN_ENABLE_AUDIT))
+	if (flags & ~(FAN_USER_INIT_FLAGS | FAN_ENABLE_AUDIT))
 #else
-	if (flags & ~FAN_ALL_INIT_FLAGS)
+	if (flags & ~FAN_USER_INIT_FLAGS)
 #endif
 		return -EINVAL;
 
@@ -746,7 +746,7 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
 	group->fanotify_data.f_flags = event_f_flags;
 	init_waitqueue_head(&group->fanotify_data.access_waitq);
 	INIT_LIST_HEAD(&group->fanotify_data.access_list);
-	switch (flags & FAN_ALL_CLASS_BITS) {
+	switch (flags & FAN_USER_CLASS_BITS) {
 	case FAN_CLASS_NOTIF:
 		group->priority = FS_PRIO_0;
 		break;
@@ -805,9 +805,11 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
 	struct fsnotify_group *group;
 	struct fd f;
 	struct path path;
-	u32 valid_mask = FAN_ALL_EVENTS | FAN_EVENT_ON_CHILD;
+	u32 valid_mask = FAN_USER_EVENTS | FAN_EVENT_ON_CHILD;
 	int ret;
 
+	BUILD_BUG_ON(FAN_USER_MARK_FLAGS & FAN_KERN_MARK_FLAGS);
+
 	pr_debug("%s: fanotify_fd=%d flags=%x dfd=%d pathname=%p mask=%llx\n",
 		 __func__, fanotify_fd, flags, dfd, pathname, mask);
 
@@ -815,7 +817,7 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
 	if (mask & ((__u64)0xffffffff << 32))
 		return -EINVAL;
 
-	if (flags & ~FAN_ALL_MARK_FLAGS)
+	if (flags & ~FAN_USER_MARK_FLAGS)
 		return -EINVAL;
 	switch (flags & (FAN_MARK_ADD | FAN_MARK_REMOVE | FAN_MARK_FLUSH)) {
 	case FAN_MARK_ADD:		/* fallthrough */
@@ -837,7 +839,7 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
 	}
 
 	if (IS_ENABLED(CONFIG_FANOTIFY_ACCESS_PERMISSIONS))
-		valid_mask |= FAN_ALL_PERM_EVENTS;
+		valid_mask |= FAN_USER_PERM_EVENTS;
 
 	if (mask & ~valid_mask)
 		return -EINVAL;
@@ -857,7 +859,7 @@ static int do_fanotify_mark(int fanotify_fd, unsigned int flags, __u64 mask,
 	 * allowed to set permissions events.
 	 */
 	ret = -EINVAL;
-	if (mask & FAN_ALL_PERM_EVENTS &&
+	if (mask & FAN_USER_PERM_EVENTS &&
 	    group->priority == FS_PRIO_0)
 		goto fput_and_out;
 
diff --git a/include/linux/fanotify.h b/include/linux/fanotify.h
index 096c96f4f16a..a67430811006 100644
--- a/include/linux/fanotify.h
+++ b/include/linux/fanotify.h
@@ -4,6 +4,56 @@
 
 #include <uapi/linux/fanotify.h>
 
-/* not valid from userspace, only kernel internal */
-#define FAN_MARK_ONDIR		0x00000100
+/*
+ * Flags not valid from userspace, only kernel internal.
+ * Use high bits so we won't collide with userspace flags.
+ */
+#define FAN_MARK_ONDIR		0x80000000
+
+#define FAN_KERN_MARK_FLAGS	(FAN_MARK_ONDIR)
+
+/*
+ * 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 FAN_USER_CLASS_BITS	(FAN_CLASS_NOTIF | FAN_CLASS_CONTENT | \
+				 FAN_CLASS_PRE_CONTENT)
+
+#define FAN_USER_INIT_FLAGS	(FAN_CLOEXEC | FAN_NONBLOCK | \
+				 FAN_USER_CLASS_BITS | \
+				 FAN_UNLIMITED_QUEUE | FAN_UNLIMITED_MARKS)
+
+#define FAN_USER_MARK_FLAGS	(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| \
+				 FAN_MARK_MOUNT)
+
+/* All events that user can request */
+#define FAN_USER_EVENTS		(FAN_ACCESS | FAN_MODIFY | \
+				 FAN_CLOSE | FAN_OPEN)
+
+/* All events which require a permission response from userspace */
+#define FAN_USER_PERM_EVENTS	(FAN_OPEN_PERM | FAN_ACCESS_PERM)
+
+/* All events that can be reported to user */
+#define FAN_USER_OUTGOING_EVENTS	(FAN_USER_EVENTS | \
+					 FAN_USER_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 */
diff --git a/include/uapi/linux/fanotify.h b/include/uapi/linux/fanotify.h
index 74247917de04..690acdbb2bec 100644
--- a/include/uapi/linux/fanotify.h
+++ b/include/uapi/linux/fanotify.h
@@ -31,6 +31,8 @@
 #define FAN_CLASS_NOTIF		0x00000000
 #define FAN_CLASS_CONTENT	0x00000004
 #define FAN_CLASS_PRE_CONTENT	0x00000008
+
+/* Deprecated - do not use this in programs and do not add new flags here! */
 #define FAN_ALL_CLASS_BITS	(FAN_CLASS_NOTIF | FAN_CLASS_CONTENT | \
 				 FAN_CLASS_PRE_CONTENT)
 
@@ -38,6 +40,7 @@
 #define FAN_UNLIMITED_MARKS	0x00000020
 #define FAN_ENABLE_AUDIT	0x00000040
 
+/* Deprecated - do not use this in programs and do not add new flags here! */
 #define FAN_ALL_INIT_FLAGS	(FAN_CLOEXEC | FAN_NONBLOCK | \
 				 FAN_ALL_CLASS_BITS | FAN_UNLIMITED_QUEUE |\
 				 FAN_UNLIMITED_MARKS)
@@ -52,6 +55,7 @@
 #define FAN_MARK_IGNORED_SURV_MODIFY	0x00000040
 #define FAN_MARK_FLUSH		0x00000080
 
+/* Deprecated - do not use this in programs and do not add new flags here! */
 #define FAN_ALL_MARK_FLAGS	(FAN_MARK_ADD |\
 				 FAN_MARK_REMOVE |\
 				 FAN_MARK_DONT_FOLLOW |\
@@ -61,11 +65,7 @@
 				 FAN_MARK_IGNORED_SURV_MODIFY |\
 				 FAN_MARK_FLUSH)
 
-/*
- * 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!
- */
+/* Deprecated - do not use this in programs and do not add new flags here! */
 #define FAN_ALL_EVENTS (FAN_ACCESS |\
 			FAN_MODIFY |\
 			FAN_CLOSE |\
@@ -74,9 +74,11 @@
 /*
  * All events which require a permission response from userspace
  */
+/* Deprecated - do not use this in programs and do not add new flags here! */
 #define FAN_ALL_PERM_EVENTS (FAN_OPEN_PERM |\
 			     FAN_ACCESS_PERM)
 
+/* Deprecated - do not use this in programs and do not add new flags here! */
 #define FAN_ALL_OUTGOING_EVENTS	(FAN_ALL_EVENTS |\
 				 FAN_ALL_PERM_EVENTS |\
 				 FAN_Q_OVERFLOW)
-- 
2.17.1

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH][RFC] fanotify: deprecate uapi FAN_ALL_* constants
  2018-09-27 22:01 [PATCH][RFC] fanotify: deprecate uapi FAN_ALL_* constants Amir Goldstein
@ 2018-10-02 15:56 ` Jan Kara
  2018-10-02 16:23   ` Amir Goldstein
  0 siblings, 1 reply; 4+ messages in thread
From: Jan Kara @ 2018-10-02 15:56 UTC (permalink / raw)
  To: Amir Goldstein; +Cc: Jan Kara, linux-fsdevel, linux-api

On Fri 28-09-18 01:01:12, Amir Goldstein wrote:
> 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 FAN_USER_*
> constants for internal use to replace them. New feature bits will be
> added only to the new constants.
> 
> Use high bits for kernel internal flag FAN_MARK_ONDIR and add
> BUILD_BUG_ON to avoid collision between uapi and kernel internal
> mark flags.
> 
> Cc: <linux-api@vger.kernel.org>
> Signed-off-by: Amir Goldstein <amir73il@gmail.com>
> ---
> 
> Jan,
> 
> I have rebased the API changes (FAN_MARK_FILESYSTEM and
> FAN_EVENT_INFO_TID) on top of commit 60f7ed8c7c4d ("fsnotify: send path
> type events to group with super block marks") from your 'fsnotify'
> branch starting with this change. The work is available on my branch
> fanotify_api-v3 [1].
> 
> The end result is that no existing uapi constant are modified and
> new bit group definitions (FAN_MARK_TYPE_MASK, FAN_EVENT_INFO_FLAGS)
> are not repeating past mistake and not exposed in uapi.
> 
> If you agree with this approach and I will post the rest of the series.
> 
> Thanks,
> Amir.
> 
> [1] https://github.com/amir73il/linux/commits/fanotify_api-v3

WRT all stuff in your tree I'd prefer if we had to rebase less stuff. What
about following:

1) AFAIU "fanotify: store fanotify_init() flags in group's fanotify_data"
needs no change so I keep it.

2) I'll drop "fanotify: support reporting thread id instead of process id"
from fsnotify for now and merge your new version once you post it together
with your cleanup of mask constants.

3) I will keep "fanotify: add API to attach/detach super block mark" as is,
just please write a separate small patch that resolves the clash between
FAN_MARK_ONDIR and FAN_MARK_FILESYSTEM.

Regarding to this patch I have just two nits:

> diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
> index 94b52157bf8d..e5a3c69848e4 100644
> --- a/fs/notify/fanotify/fanotify.c
> +++ b/fs/notify/fanotify/fanotify.c
> @@ -131,8 +131,8 @@ static bool fanotify_should_send_event(struct fsnotify_iter_info *iter_info,
>  	    !(marks_mask & FS_ISDIR & ~marks_ignored_mask))
>  		return false;
>  
> -	if (event_mask & FAN_ALL_OUTGOING_EVENTS & marks_mask &
> -				 ~marks_ignored_mask)
> +	if (event_mask & FAN_USER_OUTGOING_EVENTS &
> +	    marks_mask & ~marks_ignored_mask)
>  		return true;

I don't like the _USER_ part of the constant name. How about _KNOWN_?
I.e., FAN_KNOWN_OUTGOING_EVENTS sounds about like what it should?

...
> +	BUILD_BUG_ON(FAN_USER_MARK_FLAGS & FAN_KERN_MARK_FLAGS);
> +

We have in fsnotify_init():

BUG_ON(hweight32(ALL_FSNOTIFY_EVENTS) != 23)

Maybe we should have in fanotify_user_setup() something similar for
fanotify flags including the internal ones?

> diff --git a/include/linux/fanotify.h b/include/linux/fanotify.h
> index 096c96f4f16a..a67430811006 100644
> --- a/include/linux/fanotify.h
> +++ b/include/linux/fanotify.h
> @@ -4,6 +4,56 @@
>  
>  #include <uapi/linux/fanotify.h>
>  
> -/* not valid from userspace, only kernel internal */
> -#define FAN_MARK_ONDIR		0x00000100
> +/*
> + * Flags not valid from userspace, only kernel internal.
> + * Use high bits so we won't collide with userspace flags.
> + */
> +#define FAN_MARK_ONDIR		0x80000000

This ought to be a separate change as I wrote above.

Thanks!
								Honza

-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH][RFC] fanotify: deprecate uapi FAN_ALL_* constants
  2018-10-02 15:56 ` Jan Kara
@ 2018-10-02 16:23   ` Amir Goldstein
  2018-10-02 16:43     ` Jan Kara
  0 siblings, 1 reply; 4+ messages in thread
From: Amir Goldstein @ 2018-10-02 16:23 UTC (permalink / raw)
  To: Jan Kara; +Cc: linux-fsdevel, linux-api

On Tue, Oct 2, 2018 at 6:56 PM Jan Kara <jack@suse.cz> wrote:
>
> On Fri 28-09-18 01:01:12, Amir Goldstein wrote:
> > 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 FAN_USER_*
> > constants for internal use to replace them. New feature bits will be
> > added only to the new constants.
> >
> > Use high bits for kernel internal flag FAN_MARK_ONDIR and add
> > BUILD_BUG_ON to avoid collision between uapi and kernel internal
> > mark flags.
> >
> > Cc: <linux-api@vger.kernel.org>
> > Signed-off-by: Amir Goldstein <amir73il@gmail.com>
> > ---
> >
> > Jan,
> >
> > I have rebased the API changes (FAN_MARK_FILESYSTEM and
> > FAN_EVENT_INFO_TID) on top of commit 60f7ed8c7c4d ("fsnotify: send path
> > type events to group with super block marks") from your 'fsnotify'
> > branch starting with this change. The work is available on my branch
> > fanotify_api-v3 [1].
> >
> > The end result is that no existing uapi constant are modified and
> > new bit group definitions (FAN_MARK_TYPE_MASK, FAN_EVENT_INFO_FLAGS)
> > are not repeating past mistake and not exposed in uapi.
> >
> > If you agree with this approach and I will post the rest of the series.
> >
> > Thanks,
> > Amir.
> >
> > [1] https://github.com/amir73il/linux/commits/fanotify_api-v3
>
> WRT all stuff in your tree I'd prefer if we had to rebase less stuff. What
> about following:
>
> 1) AFAIU "fanotify: store fanotify_init() flags in group's fanotify_data"
> needs no change so I keep it.
>
> 2) I'll drop "fanotify: support reporting thread id instead of process id"
> from fsnotify for now and merge your new version once you post it together
> with your cleanup of mask constants.
>
> 3) I will keep "fanotify: add API to attach/detach super block mark" as is,
> just please write a separate small patch that resolves the clash between
> FAN_MARK_ONDIR and FAN_MARK_FILESYSTEM.
>

OK.

> Regarding to this patch I have just two nits:
>
> > diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
> > index 94b52157bf8d..e5a3c69848e4 100644
> > --- a/fs/notify/fanotify/fanotify.c
> > +++ b/fs/notify/fanotify/fanotify.c
> > @@ -131,8 +131,8 @@ static bool fanotify_should_send_event(struct fsnotify_iter_info *iter_info,
> >           !(marks_mask & FS_ISDIR & ~marks_ignored_mask))
> >               return false;
> >
> > -     if (event_mask & FAN_ALL_OUTGOING_EVENTS & marks_mask &
> > -                              ~marks_ignored_mask)
> > +     if (event_mask & FAN_USER_OUTGOING_EVENTS &
> > +         marks_mask & ~marks_ignored_mask)
> >               return true;
>
> I don't like the _USER_ part of the constant name. How about _KNOWN_?
> I.e., FAN_KNOWN_OUTGOING_EVENTS sounds about like what it should?
>

Do you mean just for *this* constant? I would rather have some uniformity
across constants if possible.

Errr... Maybe FAN_VALID_EVENTS/FAN_VALID_OUTGOING_EVENTS
Although _VALID_ is more appropriate for user inputs, so maybe just
FAN_KNOWN_OUTGOING_EVENTS as an exception to the convention
is fine.

Or simply FAN_EVENTS_MASK/FAN_OUTGOING_EVENTS_MASK, like
the recent new constant FAN_MARK_TYPE_MASK?

> ...
> > +     BUILD_BUG_ON(FAN_USER_MARK_FLAGS & FAN_KERN_MARK_FLAGS);
> > +
>
> We have in fsnotify_init():
>
> BUG_ON(hweight32(ALL_FSNOTIFY_EVENTS) != 23)
>
> Maybe we should have in fanotify_user_setup() something similar for
> fanotify flags including the internal ones?
>

OK.

> > diff --git a/include/linux/fanotify.h b/include/linux/fanotify.h
> > index 096c96f4f16a..a67430811006 100644
> > --- a/include/linux/fanotify.h
> > +++ b/include/linux/fanotify.h
> > @@ -4,6 +4,56 @@
> >
> >  #include <uapi/linux/fanotify.h>
> >
> > -/* not valid from userspace, only kernel internal */
> > -#define FAN_MARK_ONDIR               0x00000100
> > +/*
> > + * Flags not valid from userspace, only kernel internal.
> > + * Use high bits so we won't collide with userspace flags.
> > + */
> > +#define FAN_MARK_ONDIR               0x80000000
>
> This ought to be a separate change as I wrote above.
>

Sure and maybe I'll name it FAN_KERN_MARK_ONDIR.

Thanks,
Amir.

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH][RFC] fanotify: deprecate uapi FAN_ALL_* constants
  2018-10-02 16:23   ` Amir Goldstein
@ 2018-10-02 16:43     ` Jan Kara
  0 siblings, 0 replies; 4+ messages in thread
From: Jan Kara @ 2018-10-02 16:43 UTC (permalink / raw)
  To: Amir Goldstein; +Cc: Jan Kara, linux-fsdevel, linux-api

On Tue 02-10-18 19:23:53, Amir Goldstein wrote:
> On Tue, Oct 2, 2018 at 6:56 PM Jan Kara <jack@suse.cz> wrote:
> > Regarding to this patch I have just two nits:
> >
> > > diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
> > > index 94b52157bf8d..e5a3c69848e4 100644
> > > --- a/fs/notify/fanotify/fanotify.c
> > > +++ b/fs/notify/fanotify/fanotify.c
> > > @@ -131,8 +131,8 @@ static bool fanotify_should_send_event(struct fsnotify_iter_info *iter_info,
> > >           !(marks_mask & FS_ISDIR & ~marks_ignored_mask))
> > >               return false;
> > >
> > > -     if (event_mask & FAN_ALL_OUTGOING_EVENTS & marks_mask &
> > > -                              ~marks_ignored_mask)
> > > +     if (event_mask & FAN_USER_OUTGOING_EVENTS &
> > > +         marks_mask & ~marks_ignored_mask)
> > >               return true;
> >
> > I don't like the _USER_ part of the constant name. How about _KNOWN_?
> > I.e., FAN_KNOWN_OUTGOING_EVENTS sounds about like what it should?
> >
> 
> Do you mean just for *this* constant? I would rather have some uniformity
> across constants if possible.

No, I meant for all. Sorry for the confusion.

> Errr... Maybe FAN_VALID_EVENTS/FAN_VALID_OUTGOING_EVENTS
> Although _VALID_ is more appropriate for user inputs, so maybe just
> FAN_KNOWN_OUTGOING_EVENTS as an exception to the convention
> is fine.
> 
> Or simply FAN_EVENTS_MASK/FAN_OUTGOING_EVENTS_MASK, like
> the recent new constant FAN_MARK_TYPE_MASK?

Yeah, MASK is fine with me as well. So are the names with VALID. Just pick
one you like the most.

> > > diff --git a/include/linux/fanotify.h b/include/linux/fanotify.h
> > > index 096c96f4f16a..a67430811006 100644
> > > --- a/include/linux/fanotify.h
> > > +++ b/include/linux/fanotify.h
> > > @@ -4,6 +4,56 @@
> > >
> > >  #include <uapi/linux/fanotify.h>
> > >
> > > -/* not valid from userspace, only kernel internal */
> > > -#define FAN_MARK_ONDIR               0x00000100
> > > +/*
> > > + * Flags not valid from userspace, only kernel internal.
> > > + * Use high bits so we won't collide with userspace flags.
> > > + */
> > > +#define FAN_MARK_ONDIR               0x80000000
> >
> > This ought to be a separate change as I wrote above.
> >
> 
> Sure and maybe I'll name it FAN_KERN_MARK_ONDIR.

Fine by me.

								Honza
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2018-10-02 23:27 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-09-27 22:01 [PATCH][RFC] fanotify: deprecate uapi FAN_ALL_* constants Amir Goldstein
2018-10-02 15:56 ` Jan Kara
2018-10-02 16:23   ` Amir Goldstein
2018-10-02 16:43     ` Jan Kara

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