From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm1-f67.google.com ([209.85.128.67]:36309 "EHLO mail-wm1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726416AbeKZAfd (ORCPT ); Sun, 25 Nov 2018 19:35:33 -0500 From: Amir Goldstein To: Jan Kara Cc: Matthew Bobrowski , linux-fsdevel@vger.kernel.org, linux-api@vger.kernel.org Subject: [PATCH v3 13/13] fanotify: report FAN_ONDIR to listener with FAN_REPORT_FID Date: Sun, 25 Nov 2018 15:43:52 +0200 Message-Id: <20181125134352.21499-14-amir73il@gmail.com> In-Reply-To: <20181125134352.21499-1-amir73il@gmail.com> References: <20181125134352.21499-1-amir73il@gmail.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: dirent modification events (create/delete/move) do not carry the child entry name/inode information. Instead, we report FAN_ONDIR for mkdir/rmdir so user can differentiate them from creat/unlink. For backward compatibility and consistency, do not report FAN_ONDIR to user in legacy fanotify mode (reporting fd) and report FAN_ONDIR to user in FAN_REPORT_FID mode for all event types. Unlike legacy fanotify events (open/access/close), dirent events for subdir entries (mkdir/rmdir) will be reported regardless if user requested FAN_ONDIR, but the FAN_ONDIR flag itself will only be reported if the user asked for it. Cc: Signed-off-by: Amir Goldstein --- fs/notify/fanotify/fanotify.c | 31 +++++++++++++++++++++++++++++-- include/linux/fanotify.h | 9 ++++++--- 2 files changed, 35 insertions(+), 5 deletions(-) diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c index 883db359c508..610a7f8981b5 100644 --- a/fs/notify/fanotify/fanotify.c +++ b/fs/notify/fanotify/fanotify.c @@ -107,6 +107,7 @@ static u32 fanotify_group_event_mask(struct fsnotify_iter_info *iter_info, int data_type, __kernel_fsid_t *fsid) { __u32 marks_mask = 0, marks_ignored_mask = 0; + __u32 test_mask, user_mask = FANOTIFY_EVENT_TYPES; const struct path *path = data; struct fsnotify_mark *mark; int type, err; @@ -144,12 +145,38 @@ static u32 fanotify_group_event_mask(struct fsnotify_iter_info *iter_info, marks_ignored_mask |= mark->ignored_mask; } + test_mask = event_mask & marks_mask & ~marks_ignored_mask; + + /* + * dirent modification events (create/delete/move) do not carry the + * child entry name/inode information. Instead, we report FAN_ONDIR + * for mkdir/rmdir so user can differentiate them from creat/unlink. + * + * For backward compatibility and consistency, do not report FAN_ONDIR + * to user in legacy fanotify mode (reporting fd) and report FAN_ONDIR + * to user in FAN_REPORT_FID mode for all event types. + */ + if (fsid) { + /* Do not report FAN_ONDIR without an event type */ + BUILD_BUG_ON(FANOTIFY_EVENT_TYPES & FANOTIFY_EVENT_FLAGS); + if (!(test_mask & FANOTIFY_EVENT_TYPES)) + return 0; + + user_mask |= FAN_ONDIR; + } + + /* + * Unlike legacy fanotify events (open/access/close), dirent events + * for subdir entries (mkdir/rmdir) will be reported regardless if + * user requested FAN_ONDIR, but the FAN_ONDIR flag itself will only + * be reported if the user asked for it. + */ if (event_mask & FS_ISDIR && + !(event_mask & ALL_FSNOTIFY_DIRENT_EVENTS) && !(marks_mask & FS_ISDIR & ~marks_ignored_mask)) return 0; - return event_mask & FANOTIFY_OUTGOING_EVENTS & marks_mask & - ~marks_ignored_mask; + return test_mask & user_mask; } static struct fanotify_event_fid *fanotify_alloc_fid(struct inode *inode, diff --git a/include/linux/fanotify.h b/include/linux/fanotify.h index e9d45387089f..f5f86566c277 100644 --- a/include/linux/fanotify.h +++ b/include/linux/fanotify.h @@ -61,13 +61,16 @@ #define FANOTIFY_PERM_EVENTS (FAN_OPEN_PERM | FAN_ACCESS_PERM | \ FAN_OPEN_EXEC_PERM) +/* Events types that may be reported from vfs */ +#define FANOTIFY_EVENT_TYPES (FANOTIFY_EVENTS | \ + FANOTIFY_PERM_EVENTS) + /* Extra flags that may be reported with event or control handling of events */ #define FANOTIFY_EVENT_FLAGS (FAN_EVENT_ON_CHILD | FAN_ONDIR) /* Events that may be reported to user */ -#define FANOTIFY_OUTGOING_EVENTS (FANOTIFY_EVENTS | \ - FANOTIFY_PERM_EVENTS | \ - FAN_Q_OVERFLOW) +#define FANOTIFY_OUTGOING_EVENTS (FANOTIFY_EVENT_TYPES | \ + FAN_Q_OVERFLOW | FAN_ONDIR) #define ALL_FANOTIFY_EVENT_BITS (FANOTIFY_OUTGOING_EVENTS | \ FANOTIFY_EVENT_FLAGS) -- 2.17.1