Jan, This patch set follows up on the discussion on FAN_REPORT_TARGET_FID [1] from 3 months ago. With FAN_REPORT_PIDFD in 5.15 and FAN_FS_ERROR on its way to 5.16, I figured we could get an early (re)start of the discussion on FAN_REPORT_TARGET_FID towards 5.17. The added information in dirent events solves problems for my use case - It helps getting the following information in a race free manner: 1. fid of a created directory on mkdir 2. from/to path information on rename of non-dir I realize those are two different API traits, but they are close enough so I preferred not to clutter the REPORT flags space any further than it already is. The single added flag FAN_REPORT_TARGET_FID adds: 1. child fid info to CREATE/DELETE/MOVED_* events 2. new parent+name info to MOVED_FROM event Instead of going the "inotify way" and trying to join the MOVED_FROM/ MOVED_TO events using a cookie, I chose to incorporate the new parent+name intomation only in the MOVED_FROM event. I made this choice for several reasons: 1. Availability of the moved dentry in the hook and event data 2. First info record is the old parent+name, like FAN_REPORT_DFID_NAME 3. Unlike, MOVED_TO, MOVED_FROM was useless for applications that use DFID_NAME info to statat(2) the object as we suggested I chose to reduce testing complexity and require all other FID flags with FAN_REPORT_TARGET_FID and there is a convenience macro FAN_REPORT_ALL_FIDS that application can use. This restriction could be relaxed in the future if we have a good reason to do so. Since the POC branch 3 months ago, I dropped the 'sub_type' field of the info header, because it did not add much value IMO. Patches [2] and LTP test [3] are available on my github. Thanks, Amir. [1] https://lore.kernel.org/linux-fsdevel/CAOQ4uxjYDDk00VPdWtRB1_tf+gCoPFgSQ9O0p0fGaW_JiFUUKA@xxxxxxxxxxxxxx/ [2] https://github.com/amir73il/linux/commits/fanotify_target_fid [3] https://github.com/amir73il/ltp/commits/fanotify_target_fid Amir Goldstein (7): fsnotify: pass dentry instead of inode data for move events fanotify: introduce group flag FAN_REPORT_TARGET_FID fanotify: use macros to get the offset to fanotify_info buffer fanotify: support secondary dir fh and name in fanotify_info fanotify: record new parent and name in MOVED_FROM event fanotify: report new parent and name in MOVED_FROM event fanotify: enable the FAN_REPORT_TARGET_FID flag fs/notify/fanotify/fanotify.c | 108 ++++++++++++++++++++++----- fs/notify/fanotify/fanotify.h | 113 +++++++++++++++++++++++++---- fs/notify/fanotify/fanotify_user.c | 43 +++++++++-- include/linux/fanotify.h | 2 +- include/linux/fsnotify.h | 7 +- include/uapi/linux/fanotify.h | 5 ++ 6 files changed, 235 insertions(+), 43 deletions(-) -- 2.33.1
