Allow a FS_ERROR_TYPE notification to send a filesystem provided blob
back to userspace. This is useful for filesystems who want to provide
debug information for recovery tools.
Signed-off-by: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx>
---
fs/notify/fanotify/fanotify_user.c | 27 +++++++++++++++++++++++++++
include/uapi/linux/fanotify.h | 10 ++++++++--
2 files changed, 35 insertions(+), 2 deletions(-)
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index cb79a4a8e6fb..e2f4599dfc25 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -69,6 +69,14 @@ static size_t fanotify_error_info_len(struct fanotify_error_event *fee)
return sizeof(struct fanotify_event_info_error);
}
+static size_t fanotify_error_fsdata_len(struct fanotify_error_event *fee)
+{
+ if (!fee->fs_data_size)
+ return 0;
+
+ return sizeof(struct fanotify_event_info_fsdata) + fee->fs_data_size;
+}
+
static size_t fanotify_location_info_len(const struct fanotify_event_location *loc)
{
if (!loc->function)
@@ -295,6 +303,25 @@ static size_t copy_location_info_to_user(struct fanotify_event_location *locatio
return info.hdr.len;
}
+static ssize_t copy_error_fsdata_info_to_user(struct fanotify_error_event *fee,
+ char __user *buf, int count)
+{
+ struct fanotify_event_info_fsdata info;
+
+ info.hdr.info_type = FAN_EVENT_INFO_TYPE_FSDATA;
+ info.hdr.len = fanotify_error_fsdata_len(fee);
+
+ if (copy_to_user(buf, &info, sizeof(info)))
+ return -EFAULT;
+
+ buf += sizeof(info);
+
+ if (copy_to_user(buf, fee->fs_data, fee->fs_data_size))
+ return -EFAULT;
+
+ return info.hdr.len;
+}
+
static int copy_info_to_user(__kernel_fsid_t *fsid, struct fanotify_fh *fh,
int info_type, const char *name, size_t name_len,
char __user *buf, size_t count)
diff --git a/include/uapi/linux/fanotify.h b/include/uapi/linux/fanotify.h
index 67217756dac9..49808c857ee1 100644
--- a/include/uapi/linux/fanotify.h
+++ b/include/uapi/linux/fanotify.h
@@ -124,8 +124,9 @@ struct fanotify_event_metadata {
#define FAN_EVENT_INFO_TYPE_FID 1
#define FAN_EVENT_INFO_TYPE_DFID_NAME 2
#define FAN_EVENT_INFO_TYPE_DFID 3
-#define FAN_EVENT_INFO_TYPE_ERROR 4
-#define FAN_EVENT_INFO_TYPE_LOCATION 5
+#define FAN_EVENT_INFO_TYPE_LOCATION 4
+#define FAN_EVENT_INFO_TYPE_ERROR 5
+#define FAN_EVENT_INFO_TYPE_FSDATA 6
/* Variable length info record following event metadata */
struct fanotify_event_info_header {
@@ -166,6 +167,11 @@ struct fanotify_event_info_location {
char function[0];
};
+struct fanotify_event_info_fsdata {
+ struct fanotify_event_info_header hdr;
+ char data[0];
+};
+
struct fanotify_response {
__s32 fd;
__u32 response;
--
2.31.0
