linux.git/fs/notify, branch v4.13

dentry name snapshots

2017-07-08T00:09:10+00:00

take_dentry_name_snapshot() takes a safe snapshot of dentry name;
if the name is a short one, it gets copied into caller-supplied
structure, otherwise an extra reference to external name is grabbed
(those are never modified).  In either case the pointer to stable
string is stored into the same structure.

dentry must be held by the caller of take_dentry_name_snapshot(),
but may be freely dropped afterwards - the snapshot will stay
until destroyed by release_dentry_name_snapshot().

Intended use:
	struct name_snapshot s;

	take_dentry_name_snapshot(&s, dentry);
	...
	access s.name
	...
	release_dentry_name_snapshot(&s);

Replaces fsnotify_oldname_...(), gets used in fsnotify to obtain the name
to pass down with event.

Signed-off-by: Al Viro

fanotify: don't expose EOPENSTALE to userspace

2017-04-25T13:48:06+00:00

When delivering an event to userspace for a file on an NFS share,
if the file is deleted on server side before user reads the event,
user will not get the event.

If the event queue contained several events, the stale event is
quietly dropped and read() returns to user with events read so far
in the buffer.

If the event queue contains a single stale event or if the stale
event is a permission event, read() returns to user with the kernel
internal error code 518 (EOPENSTALE), which is not a POSIX error code.

Check the internal return value -EOPENSTALE in fanotify_read(), just
the same as it is checked in path_openat() and drop the event in the
cases that it is not already dropped.

This is a reproducer from Marko Rauhamaa:

Just take the example program listed under "man fanotify" ("fantest")
and follow these steps:

    ==============================================================
    NFS Server    NFS Client(1)     NFS Client(2)
    ==============================================================
    # echo foo >/nfsshare/bar.txt
                  # cat /nfsshare/bar.txt
                  foo
                                    # ./fantest /nfsshare
                                    Press enter key to terminate.
                                    Listening for events.
    # rm -f /nfsshare/bar.txt
                  # cat /nfsshare/bar.txt
                                    read: Unknown error 518
                  cat: /nfsshare/bar.txt: Operation not permitted
    ==============================================================

where NFS Client (1) and (2) are two terminal sessions on a single NFS
Client machine.

Reported-by: Marko Rauhamaa 
Tested-by: Marko Rauhamaa 
Cc: 
Cc: 
Signed-off-by: Amir Goldstein 
Signed-off-by: Jan Kara

fsnotify: remove a stray unlock

2017-04-24T14:41:28+00:00

We recently shifted this code around, so we're no longer holding the
lock on this path.

Fixes: 755b5bc681eb ("fsnotify: Remove indirection from mark list addition")
Signed-off-by: Dan Carpenter 
Signed-off-by: Jan Kara

fsnotify: Move ->free_mark callback to fsnotify_ops

2017-04-10T15:37:36+00:00

Pointer to ->free_mark callback unnecessarily occupies one long in each
fsnotify_mark although they are the same for all marks from one
notification group. Move the callback pointer to fsnotify_ops.

Reviewed-by: Miklos Szeredi 
Reviewed-by: Amir Goldstein 
Signed-off-by: Jan Kara

fsnotify: Add group pointer in fsnotify_init_mark()

2017-04-10T15:37:36+00:00

Currently we initialize mark->group only in fsnotify_add_mark_lock().
However we will need to access fsnotify_ops of corresponding group from
fsnotify_put_mark() so we need mark->group initialized earlier. Do that
in fsnotify_init_mark() which has a consequence that once
fsnotify_init_mark() is called on a mark, the mark has to be destroyed
by fsnotify_put_mark().

Reviewed-by: Miklos Szeredi 
Reviewed-by: Amir Goldstein 
Signed-off-by: Jan Kara

fsnotify: Drop inode_mark.c

2017-04-10T15:37:36+00:00

inode_mark.c now contains only a single function. Move it to
fs/notify/fsnotify.c and remove inode_mark.c.

Reviewed-by: Miklos Szeredi 
Reviewed-by: Amir Goldstein 
Signed-off-by: Jan Kara

fsnotify: Remove fsnotify_find_{inode|vfsmount}_mark()

2017-04-10T15:37:36+00:00

These are very thin wrappers, just remove them. Drop
fs/notify/vfsmount_mark.c as it is empty now.

Reviewed-by: Miklos Szeredi 
Reviewed-by: Amir Goldstein 
Signed-off-by: Jan Kara

fsnotify: Remove fsnotify_detach_group_marks()

2017-04-10T15:37:36+00:00

The function is already mostly contained in what
fsnotify_clear_marks_by_group() does. Just update that function to not
select marks when all of them should be destroyed and remove
fsnotify_detach_group_marks().

Reviewed-by: Miklos Szeredi 
Reviewed-by: Amir Goldstein 
Signed-off-by: Jan Kara

fsnotify: Rename fsnotify_clear_marks_by_group_flags()

2017-04-10T15:37:36+00:00

The _flags() suffix in the function name was more confusing than
explaining so just remove it. Also rename the argument from 'flags' to
'type' to better explain what the function expects.

Reviewed-by: Miklos Szeredi 
Suggested-by: Amir Goldstein 
Reviewed-by: Amir Goldstein 
Signed-off-by: Jan Kara

fsnotify: Inline fsnotify_clear_{inode|vfsmount}_mark_group()

2017-04-10T15:37:36+00:00

Inline these helpers as they are very thin. We still keep them as we
don't want to expose details about how list type is determined.

Reviewed-by: Miklos Szeredi 
Reviewed-by: Amir Goldstein 
Signed-off-by: Jan Kara