diff options
| -rw-r--r-- | fs/notify/fanotify/fanotify.c | 34 | ||||
| -rw-r--r-- | include/linux/fanotify.h | 2 |
2 files changed, 32 insertions, 4 deletions
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c index 158c69acb04d..4ff84bc5772e 100644 --- a/fs/notify/fanotify/fanotify.c +++ b/fs/notify/fanotify/fanotify.c @@ -34,7 +34,16 @@ static bool should_merge(struct fsnotify_event *old_fsn, return old->path.mnt == new->path.mnt && old->path.dentry == new->path.dentry; } else if (fanotify_event_has_fid(old)) { - return fanotify_fid_equal(&old->fid, &new->fid, old->fh_len); + /* + * We want to merge many dirent events in the same dir (i.e. + * creates/unlinks/renames), but we do not want to merge dirent + * events referring to subdirs with dirent events referring to + * non subdirs, otherwise, user won't be able to tell from a + * mask FAN_CREATE|FAN_DELETE|FAN_ONDIR if it describes mkdir+ + * unlink pair or rmdir+create pair of events. + */ + return (old->mask & FS_ISDIR) == (new->mask & FS_ISDIR) && + fanotify_fid_equal(&old->fid, &new->fid, old->fh_len); } /* Do not merge events if we failed to encode fid */ @@ -112,6 +121,7 @@ static u32 fanotify_group_event_mask(struct fsnotify_group *group, int data_type) { __u32 marks_mask = 0, marks_ignored_mask = 0; + __u32 test_mask, user_mask = FANOTIFY_OUTGOING_EVENTS; const struct path *path = data; struct fsnotify_mark *mark; int type; @@ -145,12 +155,30 @@ static u32 fanotify_group_event_mask(struct fsnotify_group *group, 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 (FAN_GROUP_FLAG(group, FAN_REPORT_FID)) { + /* Do not report FAN_ONDIR without any event */ + if (!(test_mask & ~FAN_ONDIR)) + return 0; + } else { + user_mask &= ~FAN_ONDIR; + } + if (event_mask & FS_ISDIR && !(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 int fanotify_encode_fid(struct fanotify_event *event, diff --git a/include/linux/fanotify.h b/include/linux/fanotify.h index e9d45387089f..b79fa9bb7359 100644 --- a/include/linux/fanotify.h +++ b/include/linux/fanotify.h @@ -67,7 +67,7 @@ /* Events that may be reported to user */ #define FANOTIFY_OUTGOING_EVENTS (FANOTIFY_EVENTS | \ FANOTIFY_PERM_EVENTS | \ - FAN_Q_OVERFLOW) + FAN_Q_OVERFLOW | FAN_ONDIR) #define ALL_FANOTIFY_EVENT_BITS (FANOTIFY_OUTGOING_EVENTS | \ FANOTIFY_EVENT_FLAGS) |