On 6/17/22 15:11, Amir Goldstein wrote:
FAN_REPORT_TARGET_FID adds an information record about the child to directory entry modification events (create/delete/move). This flag also adds sanity checks that directory modification events (create,delete,moved) cannot be set in mask of a non-dir inode mark. Reviewed-by: Matthew Bobrowski <repnop@xxxxxxxxxx> Signed-off-by: Amir Goldstein <amir73il@xxxxxxxxx>
Hi Amir, Please see some comment below. Thanks, Alex
--- man2/fanotify_init.2 | 40 +++++++++++++++++++++++++++++++++++++--- man2/fanotify_mark.2 | 7 +++++++ man7/fanotify.7 | 27 +++++++++++++-------------- 3 files changed, 57 insertions(+), 17 deletions(-) diff --git a/man2/fanotify_init.2 b/man2/fanotify_init.2 index 9abec5fca..ac4d3a305 100644 --- a/man2/fanotify_init.2 +++ b/man2/fanotify_init.2 @@ -182,9 +182,11 @@ and .BR FAN_MOVE_SELF . All the events above require an fanotify group that identifies filesystem objects by file handles. -Note that for the directory entry modification events the reported file handle -identifies the modified directory and not the created/deleted/moved child -object. +Note that without the flag +.BR FAN_REPORT_TARGET_FID , +for the directory entry modification events, +there is an inforamtion record that identifies the modified directory +and not the created/deleted/moved child object. The use of .B FAN_CLASS_CONTENT or @@ -282,6 +284,38 @@ for additional details. .B FAN_REPORT_DFID_NAME This is a synonym for .RB ( FAN_REPORT_DIR_FID | FAN_REPORT_NAME ). +.TP +.BR FAN_REPORT_TARGET_FID " (since Linux 5.17)" +.\" commit d61fd650e9d206a71fda789f02a1ced4b19944c4 +Events for fanotify groups initialized with this flag +will contain additional information about the child +correlated with directory entry modification events. +This flag must be provided in conjunction with the flags +.BR FAN_REPORT_FID , +.B FAN_REPORT_DIR_FID +and +.BR FAN_REPORT_NAME . +or else the error +.B EINVAL +will be returned. +For the directory entry modification events +.BR FAN_CREATE , +.BR FAN_DELETE , +and +.BR FAN_MOVE , +an additional record of type +.BR FAN_EVENT_INFO_TYPE_FID , +is reported in addition to the information record of type +.B FAN_EVENT_INFO_TYPE_DFID +or +.BR FAN_EVENT_INFO_TYPE_DFID_NAME . +The additional record includes a file handle +that identifies the filesystem child object +that the directory entry is referring to. +.TP +.B FAN_REPORT_DFID_NAME_TARGET +This is a synonym for +.RB ( FAN_REPORT_DFID_NAME | FAN_REPORT_FID | FAN_REPORT_TARGET_FID ). .PP .TP .BR FAN_REPORT_PIDFD " (since Linux 5.15)" diff --git a/man2/fanotify_mark.2 b/man2/fanotify_mark.2 index 3dc538b7f..ebb327bdd 100644 --- a/man2/fanotify_mark.2 +++ b/man2/fanotify_mark.2 @@ -472,6 +472,13 @@ and and .I pathname do not specify a directory. +For an fanotify group that was initialized with flag +.BR FAN_REPORT_TARGET_FID , +this error will also be returned when trying to set directory entry modification +events (e.g.,
man-pages(7):
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It only applies to the 2 lines above. The rest of the patch looks good.
+.BR FAN_CREATE , +.BR FAN_DELETE ) +in the mask of a non directory inode mark. .TP .B EOPNOTSUPP The object indicated by diff --git a/man7/fanotify.7 b/man7/fanotify.7 index f4d391603..5f2c01408 100644 --- a/man7/fanotify.7 +++ b/man7/fanotify.7 @@ -171,14 +171,14 @@ alongside the generic structure. For example, if a notification group is initialized with -.B FAN_REPORT_FID +.B FAN_REPORT_TARGET_FID and .BR FAN_REPORT_PIDFD , -then an event listener should also expect to receive both +then an event listener should expect to receive up to two .I fanotify_event_info_fid -and +information records and one .I fanotify_event_info_pidfd -structures alongside the generic +information record alongside the generic .I fanotify_event_metadata structure. Importantly, @@ -552,7 +552,15 @@ identifying a parent directory object, and one with .I info_type field value of .BR FAN_EVENT_INFO_TYPE_FID , -identifying a non-directory object. +identifying a child object. +Note that for the directory entry modification events +.BR FAN_CREATE , +.BR FAN_DELETE , +and +.BR FAN_MOVE , +an information record identifying the created/deleted/moved child object +is reported only if an fanotify group was initialized with the flag +.BR FAN_REPORT_TARGET_FID. .TP .I fsid This is a unique identifier of the filesystem containing the object @@ -572,15 +580,6 @@ filesystem as returned by It can be used to uniquely identify a file on a filesystem and can be passed as an argument to .BR open_by_handle_at (2). -Note that for the directory entry modification events -.BR FAN_CREATE , -.BR FAN_DELETE , -and -.BR FAN_MOVE , -the -.I file_handle -identifies the modified directory and not the created/deleted/moved child -object. If the value of .I info_type field is
-- Alejandro Colomar <http://www.alejandro-colomar.es/>
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