Hi Gabriel, Quick question; what userspace program are you using to test this feature? Do you have a custom testing program you are using? If so, could share it? Many thanks!! - Ted On Thu, May 20, 2021 at 10:41:23PM -0400, Gabriel Krisman Bertazi wrote: > Hi, > > This series follow up on my previous proposal [1] to support file system > wide monitoring. As suggested by Amir, this proposal drops the ring > buffer in favor of a single slot associated with each mark. This > simplifies a bit the implementation, as you can see in the code. > > As a reminder, This proposal is limited to an interface for > administrators to monitor the health of a file system, instead of a > generic inteface for file errors. Therefore, this doesn't solve the > problem of writeback errors or the need to watch a specific subtree. > > In comparison to the previous RFC, this implementation also drops the > per-fs data and location, and leave those as future extensions. > > * Implementation > > The feature is implemented on top of fanotify, as a new type of fanotify > mark, FAN_ERROR, which a file system monitoring tool can register to > receive error notifications. When an error occurs a new notification is > generated, in addition followed by this info field: > > - FS generic data: A file system agnostic structure that has a generic > error code and identifies the filesystem. Basically, it let's > userspace know something happened on a monitored filesystem. Since > only the first error is recorded since the last read, this also > includes a counter of errors that happened since the last read. > > * Testing > > This was tested by watching notifications flowing from an intentionally > corrupted filesystem in different places. In addition, other events > were watched in an attempt to detect regressions. > > Is there a specific testsuite for fanotify I should be running? > > * Patches > > This patchset is divided as follows: Patch 1 through 5 are refactoring > to fsnotify/fanotify in preparation for FS_ERROR/FAN_ERROR; patch 6 and > 7 implement the FS_ERROR API for filesystems to report error; patch 8 > add support for FAN_ERROR in fanotify; Patch 9 is an example > implementation for ext4; patch 10 and 11 provide a sample userspace code > and documentation. > > I also pushed the full series to: > > https://gitlab.collabora.com/krisman/linux -b fanotify-notifications-single-slot > > [1] https://lwn.net/Articles/854545/ > > Cc: Darrick J. Wong <djwong@xxxxxxxxxx> > Cc: Theodore Ts'o <tytso@xxxxxxx> > Cc: Dave Chinner <david@xxxxxxxxxxxxx> > Cc: jack@xxxxxxxx > To: amir73il@xxxxxxxxx > Cc: dhowells@xxxxxxxxxx > Cc: khazhy@xxxxxxxxxx > Cc: linux-fsdevel@xxxxxxxxxxxxxxx > Cc: linux-ext4@xxxxxxxxxxxxxxx > > Gabriel Krisman Bertazi (11): > fanotify: Fold event size calculation to its own function > fanotify: Split fsid check from other fid mode checks > fanotify: Simplify directory sanity check in DFID_NAME mode > fanotify: Expose fanotify_mark > inotify: Don't force FS_IN_IGNORED > fsnotify: Support FS_ERROR event type > fsnotify: Introduce helpers to send error_events > fanotify: Introduce FAN_ERROR event > ext4: Send notifications on error > samples: Add fs error monitoring example > Documentation: Document the FAN_ERROR event > > .../admin-guide/filesystem-monitoring.rst | 52 +++++ > Documentation/admin-guide/index.rst | 1 + > fs/ext4/super.c | 8 + > fs/notify/fanotify/fanotify.c | 80 ++++++- > fs/notify/fanotify/fanotify.h | 38 +++- > fs/notify/fanotify/fanotify_user.c | 213 ++++++++++++++---- > fs/notify/inotify/inotify_user.c | 6 +- > include/linux/fanotify.h | 6 +- > include/linux/fsnotify.h | 13 ++ > include/linux/fsnotify_backend.h | 15 +- > include/uapi/linux/fanotify.h | 10 + > samples/Kconfig | 8 + > samples/Makefile | 1 + > samples/fanotify/Makefile | 3 + > samples/fanotify/fs-monitor.c | 91 ++++++++ > 15 files changed, 485 insertions(+), 60 deletions(-) > create mode 100644 Documentation/admin-guide/filesystem-monitoring.rst > create mode 100644 samples/fanotify/Makefile > create mode 100644 samples/fanotify/fs-monitor.c > > -- > 2.31.0 >
