user/sven/linux.git/include/uapi/linux/fanotify.h, branch v5.18.18

fanotify: report old and/or new parent+name in FAN_RENAME event

2021-12-15T14:57:31Z

In the special case of FAN_RENAME event, we report old or new or both old and new parent+name. A single info record will be reported if either the old or new dir is watched and two records will be reported if both old and new dir (or their filesystem) are watched. The old and new parent+name are reported using new info record types FAN_EVENT_INFO_TYPE_{OLD,NEW}_DFID_NAME, so if a single info record is reported, it is clear to the application, to which dir entry the fid+name info is referring to. Link: https://lore.kernel.org/r/20211129201537.1932819-11-amir73il@gmail.com Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara

fanotify: record old and new parent and name in FAN_RENAME event

2021-12-15T13:04:56Z

In the special case of FAN_RENAME event, we record both the old and new parent and name. Link: https://lore.kernel.org/r/20211129201537.1932819-9-amir73il@gmail.com Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara

fanotify: introduce group flag FAN_REPORT_TARGET_FID

2021-12-15T13:04:25Z

FAN_REPORT_FID is ambiguous in that it reports the fid of the child for some events and the fid of the parent for create/delete/move events. The new FAN_REPORT_TARGET_FID flag is an implicit request to report the fid of the target object of the operation (a.k.a the child inode) also in create/delete/move events in addition to the fid of the parent and the name of the child. To reduce the test matrix for uninteresting use cases, the new FAN_REPORT_TARGET_FID flag requires both FAN_REPORT_NAME and FAN_REPORT_FID. The convenience macro FAN_REPORT_DFID_NAME_TARGET combines FAN_REPORT_TARGET_FID with all the required flags. Link: https://lore.kernel.org/r/20211129201537.1932819-4-amir73il@gmail.com Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara

fanotify: Emit generic error info for error event

2021-10-27T10:53:42Z

The error info is a record sent to users on FAN_FS_ERROR events documenting the type of error. It also carries an error count, documenting how many errors were observed since the last reporting. Link: https://lore.kernel.org/r/20211025192746.66445-28-krisman@collabora.com Reviewed-by: Amir Goldstein Reviewed-by: Jan Kara Signed-off-by: Gabriel Krisman Bertazi Signed-off-by: Jan Kara

fanotify: Reserve UAPI bits for FAN_FS_ERROR

2021-10-27T10:34:59Z

FAN_FS_ERROR allows reporting of event type FS_ERROR to userspace, which is a mechanism to report file system wide problems via fanotify. This commit preallocate userspace visible bits to match the FS_ERROR event. Link: https://lore.kernel.org/r/20211025192746.66445-19-krisman@collabora.com Reviewed-by: Jan Kara Reviewed-by: Amir Goldstein Signed-off-by: Gabriel Krisman Bertazi Signed-off-by: Jan Kara

fanotify: add pidfd support to the fanotify API

2021-08-10T11:08:49Z

Introduce a new flag FAN_REPORT_PIDFD for fanotify_init(2) which allows userspace applications to control whether a pidfd information record containing a pidfd is to be returned alongside the generic event metadata for each event. If FAN_REPORT_PIDFD is enabled for a notification group, an additional struct fanotify_event_info_pidfd object type will be supplied alongside the generic struct fanotify_event_metadata for a single event. This functionality is analogous to that of FAN_REPORT_FID in terms of how the event structure is supplied to a userspace application. Usage of FAN_REPORT_PIDFD with FAN_REPORT_FID/FAN_REPORT_DFID_NAME is permitted, and in this case a struct fanotify_event_info_pidfd object will likely follow any struct fanotify_event_info_fid object. Currently, the usage of the FAN_REPORT_TID flag is not permitted along with FAN_REPORT_PIDFD as the pidfd API currently only supports the creation of pidfds for thread-group leaders. Additionally, usage of the FAN_REPORT_PIDFD flag is limited to privileged processes only i.e. event listeners that are running with the CAP_SYS_ADMIN capability. Attempting to supply the FAN_REPORT_TID initialization flags with FAN_REPORT_PIDFD or creating a notification group without CAP_SYS_ADMIN will result with -EINVAL being returned to the caller. In the event of a pidfd creation error, there are two types of error values that can be reported back to the listener. There is FAN_NOPIDFD, which will be reported in cases where the process responsible for generating the event has terminated prior to the event listener being able to read the event. Then there is FAN_EPIDFD, which will be reported when a more generic pidfd creation error has occurred when fanotify calls pidfd_create(). Link: https://lore.kernel.org/r/5f9e09cff7ed62bfaa51c1369e0f7ea5f16a91aa.1628398044.git.repnop@google.com Signed-off-by: Matthew Bobrowski Signed-off-by: Jan Kara

fanotify: add support for FAN_REPORT_NAME

2020-07-27T21:24:00Z

Introduce a new fanotify_init() flag FAN_REPORT_NAME. It requires the flag FAN_REPORT_DIR_FID and there is a constant for setting both flags named FAN_REPORT_DFID_NAME. For a group with flag FAN_REPORT_NAME, the parent fid and name are reported for directory entry modification events (create/detete/move) and for events on non-directory objects. Events on directories themselves are reported with their own fid and "." as the name. The parent fid and name are reported with an info record of type FAN_EVENT_INFO_TYPE_DFID_NAME, similar to the way that parent fid is reported with into type FAN_EVENT_INFO_TYPE_DFID, but with an appended null terminated name string. Link: https://lore.kernel.org/r/20200716084230.30611-21-amir73il@gmail.com Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara

fanotify: add basic support for FAN_REPORT_DIR_FID

2020-07-27T21:24:00Z

For now, the flag is mutually exclusive with FAN_REPORT_FID. Events include a single info record of type FAN_EVENT_INFO_TYPE_DFID with a directory file handle. For now, events are only reported for: - Directory modification events - Events on children of a watching directory - Events on directory objects Soon, we will add support for reporting the parent directory fid for events on non-directories with filesystem/mount mark and support for reporting both parent directory fid and child fid. Link: https://lore.kernel.org/r/20200716084230.30611-19-amir73il@gmail.com Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara

fanotify: remove event FAN_DIR_MODIFY

2020-07-27T19:23:36Z

It was never enabled in uapi and its functionality is about to be superseded by events FAN_CREATE, FAN_DELETE, FAN_MOVE with group flag FAN_REPORT_NAME. Keep a place holder variable name_event instead of removing the name recording code since it will be used by the new events. Link: https://lore.kernel.org/r/20200708111156.24659-17-amir73il@gmail.com Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara

fanotify: report name info for FAN_DIR_MODIFY event

2020-03-25T22:17:16Z

Report event FAN_DIR_MODIFY with name in a variable length record similar to how fid's are reported. With name info reporting implemented, setting FAN_DIR_MODIFY in mark mask is now allowed. When events are reported with name, the reported fid identifies the directory and the name follows the fid. The info record type for this event info is FAN_EVENT_INFO_TYPE_DFID_NAME. For now, all reported events have at most one info record which is either FAN_EVENT_INFO_TYPE_FID or FAN_EVENT_INFO_TYPE_DFID_NAME (for FAN_DIR_MODIFY). Later on, events "on child" will report both records. There are several ways that an application can use this information: 1. When watching a single directory, the name is always relative to the watched directory, so application need to fstatat(2) the name relative to the watched directory. 2. When watching a set of directories, the application could keep a map of dirfd for all watched directories and hash the map by fid obtained with name_to_handle_at(2). When getting a name event, the fid in the event info could be used to lookup the base dirfd in the map and then call fstatat(2) with that dirfd. 3. When watching a filesystem (FAN_MARK_FILESYSTEM) or a large set of directories, the application could use open_by_handle_at(2) with the fid in event info to obtain dirfd for the directory where event happened and call fstatat(2) with this dirfd. The last option scales better for a large number of watched directories. The first two options may be available in the future also for non privileged fanotify watchers, because open_by_handle_at(2) requires the CAP_DAC_READ_SEARCH capability. Link: https://lore.kernel.org/r/20200319151022.31456-15-amir73il@gmail.com Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara