Jan, This is v2 of the fanotify name info series. The user requirement for the name info feature, as well as early UAPI discussions can be found in this [1] lore thread. The "prep" part of v1 was posted to the list [2] and includes two minor bug fixes, but I decided not to split the submission into two series this posting. The patches are also available on my github branch fanotify_name [3] along with LTP tests [4], man page draft [5] and a demo [6]. Patches 1-7 are cleanup and minor re-factoring in prep for the name info patches. Patches 8-9 are fixes for minor bug that I found during the work. The referred LTP branch [4] includes improvements to ltp tests fanotify09 and fanotify15 to cover these bugs. I did not mark those patches for stable, because backporting is not trivial and the bugs are really minor. For the same reason, I did not bother to provide bug fix patches that are not dependent on the cleanup patches. Patches 10-13 implement the new event type FAN_DIR_MODIFY per your suggestion, which includes the directory fid and entry name info. Patches 14-15 implement the FAN_REPORT_NAME init flag for reporting name info on path type events. Patch 16 is a "bonus" patch that implements an unprivileged fanotify watch. It is not proposed for merging at this time, but is provided in order to demonstrate how name info reporting is applicable for an unprivileged watcher, should we decide to implement the feature. LTP tests, man page draft for unprivileged fanotify written by Matthew Bobrowski are available on fanotify_unpriv branches in respective trees. The inotify demo branch [6] includes a script test_demo.sh whose output [7] can be seen here below. The demo generates filesystem events including file and directory renames, sleeps 2 seconds and then reads the events from the queue and generates a report on changes in the filesystem. At event report time, the watcher uses open_by_handle_at(2) to report up-to-date paths for parent dirs. The last name element in the path is reported as it was recorded at event time, but the watcher uses fstatat(2) to check whether the reported entry is negative or positive. Negative entry paths are annotated with "(deleted)" postfix. The idea is that file change monitors will use this information to query the content of modified directories and file and update a secondary data structure or take other actions. The demo scripts can run as root and non-root user. When run as non-root user, if the bonus FAN_UNPRIVILEGED patch is applied, it demonstrates the unprivileged fanotify recursive watcher and produces the exact same report information as the privileged filesystem watcher. Thanks, Amir. Changes since v1: - A few more cleanup patches - Drop the abstract take_name_snapshot() vfs interface change - Do not obfuscate event type for path type events - Deal with the corner cases of event on root and disconnected dentry - Bonus FAN_UNPRIVILEGED patch [1] https://lore.kernel.org/linux-fsdevel/CADKPpc2RuncyN+ZONkwBqtW7iBb5ep_3yQN7PKe7ASn8DpNvBw@xxxxxxxxxxxxxx/ [2] https://lore.kernel.org/linux-fsdevel/20200114151655.29473-1-amir73il@xxxxxxxxx/ [3] https://github.com/amir73il/linux/commits/fanotify_name [4] https://github.com/amir73il/ltp/commits/fanotify_name [5] https://github.com/amir73il/man-pages/commits/fanotify_name [6] https://github.com/amir73il/inotify-tools/commits/fanotify_name [7] Demo run of inotifywatch race free monitor ============================================== ~# ./test_demo.sh /vdf + WD=/vdf + cd /vdf + rm -rf a + mkdir -p a/b/c/d/e/f/g/ + touch a/b/c/0 a/b/c/1 a/b/c/d/e/f/g/0 + id -u + [ 0 = 0 ] + MODE=--global + EVENTS=-e dir_modify -e modify -e attrib -e close_write + sleep 1 + inotifywatch --global -e dir_modify -e modify -e attrib -e close_write --timeout -2 /vdf Establishing filesystem global watch... Finished establishing watches, now collecting statistics. Sleeping for 2 seconds... + + t=Create files and dirs... + touch a/0 a/1 a/2 a/3 + mkdir a/dir0 a/dir1 a/dir2 + + t=Rename files and dirs... + mv a/0 a/3 + mv a/dir0 a/dir3 + + t=Delete files and dirs... + rm a/1 + rmdir a/dir1 + + t=Modify files and dirs... + chmod +x a/b/c/d + echo + + t=Move files and dirs... + mv a/b/c/1 a/b/c/d/e/f/g/1 + mv a/b/c/d/e/f/g a/b/c/d/e/G + [fid=fd50.0.2007403;name='0'] /vdf/a/0 (deleted) [fid=fd50.0.2007403;name='1'] /vdf/a/1 (deleted) [fid=fd50.0.2007403;name='2'] /vdf/a/2 [fid=fd50.0.2007403;name='3'] /vdf/a/3 [fid=fd50.0.2007403;name='dir0'] /vdf/a/dir0 (deleted) [fid=fd50.0.2007403;name='dir1'] /vdf/a/dir1 (deleted) [fid=fd50.0.2007403;name='dir2'] /vdf/a/dir2 [fid=fd50.0.2007403;name='dir3'] /vdf/a/dir3 [fid=fd50.0.86;name='d'] /vdf/a/b/c/d [fid=fd50.0.86;name='0'] /vdf/a/b/c/0 [fid=fd50.0.86;name='1'] /vdf/a/b/c/1 (deleted) [fid=fd50.0.87;name='1'] /vdf/a/b/c/d/e/G/1 [fid=fd50.0.3000083;name='g'] /vdf/a/b/c/d/e/f/g (deleted) [fid=fd50.0.2007404;name='G'] /vdf/a/b/c/d/e/G total modify attrib close_write dir_modify filename 3 0 1 1 2 /vdf/a/0 (deleted) 3 0 1 1 2 /vdf/a/1 (deleted) 3 0 1 1 2 /vdf/a/3 2 0 1 1 1 /vdf/a/2 2 0 0 0 2 /vdf/a/dir0 (deleted) 2 0 0 0 2 /vdf/a/dir1 (deleted) 1 0 0 0 1 /vdf/a/dir2 1 0 0 0 1 /vdf/a/dir3 1 0 1 0 0 /vdf/a/b/c/d 1 1 0 1 0 /vdf/a/b/c/0 1 0 0 0 1 /vdf/a/b/c/1 (deleted) 1 0 0 0 1 /vdf/a/b/c/d/e/G/1 1 0 0 0 1 /vdf/a/b/c/d/e/f/g (deleted) 1 0 0 0 1 /vdf/a/b/c/d/e/G ============================================== Amir Goldstein (16): fsnotify: tidy up FS_ and FAN_ constants fsnotify: factor helpers fsnotify_dentry() and fsnotify_file() fsnotify: funnel all dirent events through fsnotify_name() fsnotify: use helpers to access data by data_type fsnotify: simplify arguments passing to fsnotify_parent() fsnotify: pass dentry instead of inode for events possible on child fsnotify: replace inode pointer with tag fanotify: merge duplicate events on parent and child fanotify: fix merging marks masks with FAN_ONDIR fanotify: send FAN_DIR_MODIFY event flavor with dir inode and name fanotify: prepare to encode both parent and child fid's fanotify: record name info for FAN_DIR_MODIFY event fanotify: report name info for FAN_DIR_MODIFY event fanotify: report parent fid + name with FAN_REPORT_NAME fanotify: refine rules for when name is reported fanotify: support limited functionality for unprivileged users fs/notify/fanotify/fanotify.c | 231 +++++++++++++++++++++------ fs/notify/fanotify/fanotify.h | 111 ++++++++++--- fs/notify/fanotify/fanotify_user.c | 182 +++++++++++++++++---- fs/notify/fsnotify.c | 22 +-- fs/notify/inotify/inotify_fsnotify.c | 10 +- include/linux/fanotify.h | 21 ++- include/linux/fsnotify.h | 135 +++++++--------- include/linux/fsnotify_backend.h | 87 +++++++--- include/uapi/linux/fanotify.h | 11 +- kernel/audit_fsnotify.c | 13 +- kernel/audit_watch.c | 16 +- 11 files changed, 584 insertions(+), 255 deletions(-) base-commit: 11a48a5a18c63fd7621bb050228cebf13566e4d8 -- 2.17.1
