| Message ID | adfd31f369528c9958922d901fbe8eba48dfe496.1721931241.git.josef@toxicpanda.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | fanotify: add pre-content hooks | expand |
On Thu 25-07-24 14:19:38, Josef Bacik wrote: > Previously we would only include optional information if you requested > it via an FAN_ flag at fanotify_init time (FAN_REPORT_FID for example). > However this isn't necessary as the event length is encoded in the > metadata, and if the user doesn't want to consume the information they > don't have to. So I somewhat disagree with this statement because historically there was fanotify userspace that completely ignored event length reported in the event and assumed particular hardcoded constant that was working for years. That's why we are careful and add info to *existing* events only if userspace explicitely asks for it (by which it obviously also acknowledges that it is ready to parse/skip it). Now here we are adding range info only to new events so preexisting userspace isn't a problem in this case. And I agree it is kind of pointless to add a new flag, just to be able to tell you want info without which these events are pointless. Also as far as I can tell these changes will not result in any new info records to be generated for existing events. So I would just change the description to something like: New pre-content events will be path events but they will also carry additional range information. Remove the optimization to skip checking whether info structures need to be generated for path events. This results in no change in generated info structures for existing events. Honza > With the PRE_ACCESS events we will always generate range > information, so drop this check in order to allow this extra > information to be exported without needing to have another flag. > > Signed-off-by: Josef Bacik <josef@toxicpanda.com> > --- > fs/notify/fanotify/fanotify_user.c | 13 ++++--------- > 1 file changed, 4 insertions(+), 9 deletions(-) > > diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c > index 9ec313e9f6e1..2e2fba8a9d20 100644 > --- a/fs/notify/fanotify/fanotify_user.c > +++ b/fs/notify/fanotify/fanotify_user.c > @@ -160,9 +160,6 @@ static size_t fanotify_event_len(unsigned int info_mode, > int fh_len; > int dot_len = 0; > > - if (!info_mode) > - return event_len; > - > if (fanotify_is_error_event(event->mask)) > event_len += FANOTIFY_ERROR_INFO_LEN; > > @@ -740,12 +737,10 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group, > if (fanotify_is_perm_event(event->mask)) > FANOTIFY_PERM(event)->fd = fd; > > - if (info_mode) { > - ret = copy_info_records_to_user(event, info, info_mode, pidfd, > - buf, count); > - if (ret < 0) > - goto out_close_fd; > - } > + ret = copy_info_records_to_user(event, info, info_mode, pidfd, > + buf, count); > + if (ret < 0) > + goto out_close_fd; > > if (f) > fd_install(fd, f); > -- > 2.43.0 >
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c index 9ec313e9f6e1..2e2fba8a9d20 100644 --- a/fs/notify/fanotify/fanotify_user.c +++ b/fs/notify/fanotify/fanotify_user.c @@ -160,9 +160,6 @@ static size_t fanotify_event_len(unsigned int info_mode, int fh_len; int dot_len = 0; - if (!info_mode) - return event_len; - if (fanotify_is_error_event(event->mask)) event_len += FANOTIFY_ERROR_INFO_LEN; @@ -740,12 +737,10 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group, if (fanotify_is_perm_event(event->mask)) FANOTIFY_PERM(event)->fd = fd; - if (info_mode) { - ret = copy_info_records_to_user(event, info, info_mode, pidfd, - buf, count); - if (ret < 0) - goto out_close_fd; - } + ret = copy_info_records_to_user(event, info, info_mode, pidfd, + buf, count); + if (ret < 0) + goto out_close_fd; if (f) fd_install(fd, f);
Previously we would only include optional information if you requested it via an FAN_ flag at fanotify_init time (FAN_REPORT_FID for example). However this isn't necessary as the event length is encoded in the metadata, and if the user doesn't want to consume the information they don't have to. With the PRE_ACCESS events we will always generate range information, so drop this check in order to allow this extra information to be exported without needing to have another flag. Signed-off-by: Josef Bacik <josef@toxicpanda.com> --- fs/notify/fanotify/fanotify_user.c | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-)