On Wed, Jul 21, 2021 at 9:35 AM Amir Goldstein <amir73il@xxxxxxxxx> wrote:
>
> On Wed, Jul 21, 2021 at 9:18 AM Matthew Bobrowski <repnop@xxxxxxxxxx> wrote:
> >
> > The copy_info_records_to_user() helper allows for the separation of
> > info record copying routines/conditionals from copy_event_to_user(),
> > which reduces the overall clutter within this function. This becomes
> > especially true as we start introducing additional info records in the
> > future i.e. struct fanotify_event_info_pidfd. On success, this helper
> > returns the total amount of bytes that have been copied into the user
> > supplied buffer and on error, a negative value is returned to the
> > caller.
> >
> > The newly defined macro FANOTIFY_INFO_MODES can be used to obtain info
> > record types that have been enabled for a specific notification
> > group. This macro becomes useful in the subsequent patch when the
> > FAN_REPORT_PIDFD initialization flag is introduced.
> >
> > Signed-off-by: Matthew Bobrowski <repnop@xxxxxxxxxx>
> Reviewed-by: Amir Goldstein <amir73il@xxxxxxxxx>
>
> > ---
> > fs/notify/fanotify/fanotify_user.c | 155 ++++++++++++++++-------------
> > include/linux/fanotify.h | 2 +
> > 2 files changed, 90 insertions(+), 67 deletions(-)
> >
> > diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
> > index 182fea255376..d19f70b2c24c 100644
> > --- a/fs/notify/fanotify/fanotify_user.c
> > +++ b/fs/notify/fanotify/fanotify_user.c
> > @@ -173,7 +173,7 @@ static struct fanotify_event *get_one_event(struct fsnotify_group *group,
> > size_t event_size = FAN_EVENT_METADATA_LEN;
> > struct fanotify_event *event = NULL;
> > struct fsnotify_event *fsn_event;
> > - unsigned int fid_mode = FAN_GROUP_FLAG(group, FANOTIFY_FID_BITS);
> > + unsigned int info_mode = FAN_GROUP_FLAG(group, FANOTIFY_INFO_MODES);
> >
> > pr_debug("%s: group=%p count=%zd\n", __func__, group, count);
> >
> > @@ -183,8 +183,8 @@ static struct fanotify_event *get_one_event(struct fsnotify_group *group,
> > goto out;
> >
> > event = FANOTIFY_E(fsn_event);
> > - if (fid_mode)
> > - event_size += fanotify_event_info_len(fid_mode, event);
> > + if (info_mode)
> > + event_size += fanotify_event_info_len(info_mode, event);
> >
> > if (event_size > count) {
> > event = ERR_PTR(-EINVAL);
> > @@ -401,6 +401,86 @@ static int copy_fid_info_to_user(__kernel_fsid_t *fsid, struct fanotify_fh *fh,
> > return info_len;
> > }
> >
> > +static int copy_info_records_to_user(struct fanotify_event *event,
> > + struct fanotify_info *info,
> > + unsigned int info_mode,
> > + char __user *buf, size_t count)
> > +{
> > + int ret, total_bytes = 0, info_type = 0;
> > + unsigned int fid_mode = info_mode & FANOTIFY_FID_BITS;
> > +
> > + /*
> > + * Event info records order is as follows: dir fid + name, child fid.
> > + */
> > + if (fanotify_event_dir_fh_len(event)) {
> > + info_type = info->name_len ? FAN_EVENT_INFO_TYPE_DFID_NAME :
> > + FAN_EVENT_INFO_TYPE_DFID;
> > + ret = copy_fid_info_to_user(fanotify_event_fsid(event),
> > + fanotify_info_dir_fh(info),
> > + info_type,
> > + fanotify_info_name(info),
> > + info->name_len, buf, count);
> > + if (ret < 0)
> > + return ret;
> > +
> > + buf += ret;
> > + count -= ret;
> > + total_bytes += ret;
> > + }
> > +
> > + if (fanotify_event_object_fh_len(event)) {
> > + const char *dot = NULL;
> > + int dot_len = 0;
> > +
> > + if (fid_mode == FAN_REPORT_FID || info_type) {
> > + /*
> > + * With only group flag FAN_REPORT_FID only type FID is
> > + * reported. Second info record type is always FID.
> > + */
> > + info_type = FAN_EVENT_INFO_TYPE_FID;
> > + } else if ((fid_mode & FAN_REPORT_NAME) &&
> > + (event->mask & FAN_ONDIR)) {
> > + /*
> > + * With group flag FAN_REPORT_NAME, if name was not
> > + * recorded in an event on a directory, report the name
> > + * "." with info type DFID_NAME.
> > + */
> > + info_type = FAN_EVENT_INFO_TYPE_DFID_NAME;
> > + dot = ".";
> > + dot_len = 1;
> > + } else if ((event->mask & ALL_FSNOTIFY_DIRENT_EVENTS) ||
> > + (event->mask & FAN_ONDIR)) {
> > + /*
> > + * With group flag FAN_REPORT_DIR_FID, a single info
> > + * record has type DFID for directory entry
> > + * modificatio\ n event and for event on a directory.
Just notices this typo in the copied comment:
modificatio\ n
And for the next posting, please remove the mention of fanotify_user.c from
the commit title - it adds no information and clutters the git oneline log.
This concerns patch 3/5 as well. It does NOT concern the kernel/pid.c patches.
Thanks,
Amir.
