On Thu 10-01-19 19:04:42, Amir Goldstein wrote:
> When event data type is FSNOTIFY_EVENT_INODE, we don't have a refernece
> to the mount, so we will not be able to open a file descriptor when user
> reads the event. However, if the listener has enabled reporting file
> identifier with the FAN_REPORT_FID init flag, we allow reporting those
> events and we use an identifier inode to encode fid.
>
> The inode to use as identifier when reporting fid depends on the event.
> For dirent modification events, we report the modified directory inode
> and we report the "victim" inode otherwise.
> For example:
> FS_ATTRIB reports the child inode even if reported on a watched parent.
> FS_CREATE reports the modified dir inode and not the created inode.
>
> Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
> ---
> fs/notify/fanotify/fanotify.c | 67 ++++++++++++++++++++----------
> fs/notify/fanotify/fanotify.h | 2 +-
> fs/notify/fanotify/fanotify_user.c | 3 +-
> 3 files changed, 48 insertions(+), 24 deletions(-)
>
> diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c
> index fcb98ea99508..e3ca1632feb8 100644
> --- a/fs/notify/fanotify/fanotify.c
> +++ b/fs/notify/fanotify/fanotify.c
> @@ -96,7 +96,7 @@ static int fanotify_get_response(struct fsnotify_group *group,
>
> pr_debug("%s: group=%p event=%p about to return ret=%d\n", __func__,
> group, event, ret);
> -
> +
> return ret;
> }
>
> @@ -106,9 +106,10 @@ static int fanotify_get_response(struct fsnotify_group *group,
> * been included within the event mask, but have not been explicitly
> * requested by the user, will not be present in the returned mask.
> */
> -static u32 fanotify_group_event_mask(struct fsnotify_iter_info *iter_info,
> - u32 event_mask, const void *data,
> - int data_type)
> +static u32 fanotify_group_event_mask(struct fsnotify_group *group,
> + struct fsnotify_iter_info *iter_info,
> + u32 event_mask, const void *data,
> + int data_type)
> {
> __u32 marks_mask = 0, marks_ignored_mask = 0;
> const struct path *path = data;
> @@ -118,14 +119,14 @@ static u32 fanotify_group_event_mask(struct fsnotify_iter_info *iter_info,
> pr_debug("%s: report_mask=%x mask=%x data=%p data_type=%d\n",
> __func__, iter_info->report_mask, event_mask, data, data_type);
>
> - /* If we don't have enough info to send an event to userspace say no */
> - if (data_type != FSNOTIFY_EVENT_PATH)
> - return 0;
> -
> - /* Sorry, fanotify only gives a damn about files and dirs */
> - if (!d_is_reg(path->dentry) &&
> - !d_can_lookup(path->dentry))
> + if (data_type == FSNOTIFY_EVENT_PATH) {
> + /* Path type events are only relevant for files and dirs */
> + if (!d_is_reg(path->dentry) && !d_can_lookup(path->dentry))
> + return 0;
Hum, does this mean that fanotify won't report O_PATH open on symlink
unlike inotify? So shouldn't the condition rather be:
if (!FAN_GROUP_FLAG(group, FAN_REPORT_FID)) {
if (data_type != FSNOTIFY_EVENT_PATH)
return 0;
if (!d_is_reg(path->dentry) && !d_can_lookup(path->dentry))
return 0;
}
?
Honza
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
