The Error info type 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.
Signed-off-by: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx>
---
fs/notify/fanotify/fanotify_user.c | 35 ++++++++++++++++++++++++++++++
include/uapi/linux/fanotify.h | 7 ++++++
2 files changed, 42 insertions(+)
diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index 74def82630bb..ea22586c39e6 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -107,6 +107,8 @@ struct kmem_cache *fanotify_perm_event_cachep __read_mostly;
#define FANOTIFY_EVENT_ALIGN 4
#define FANOTIFY_INFO_HDR_LEN \
(sizeof(struct fanotify_event_info_fid) + sizeof(struct file_handle))
+#define FANOTIFY_INFO_ERROR_LEN \
+ (sizeof(struct fanotify_event_info_error))
static int fanotify_fid_info_len(int fh_len, int name_len)
{
@@ -130,6 +132,9 @@ static size_t fanotify_event_len(struct fanotify_event *event,
if (!fid_mode)
return event_len;
+ if (fanotify_is_error_event(event->mask))
+ event_len += FANOTIFY_INFO_ERROR_LEN;
+
info = fanotify_event_info(event);
dir_fh_len = fanotify_event_dir_fh_len(event);
fh_len = fanotify_event_object_fh_len(event);
@@ -395,6 +400,28 @@ static int process_access_response(struct fsnotify_group *group,
return -ENOENT;
}
+static size_t copy_error_info_to_user(struct fanotify_event *event,
+ char __user *buf, int count)
+{
+ struct fanotify_event_info_error info;
+ struct fanotify_error_event *fee = FANOTIFY_EE(event);
+
+ info.hdr.info_type = FAN_EVENT_INFO_TYPE_ERROR;
+ info.hdr.pad = 0;
+ info.hdr.len = FANOTIFY_INFO_ERROR_LEN;
+
+ if (WARN_ON(count < info.hdr.len))
+ return -EFAULT;
+
+ info.error = fee->error;
+ info.error_count = fee->err_count;
+
+ if (copy_to_user(buf, &info, sizeof(info)))
+ 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)
@@ -553,6 +580,14 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group,
if (f)
fd_install(fd, f);
+ if (fanotify_is_error_event(event->mask)) {
+ ret = copy_error_info_to_user(event, buf, count);
+ if (ret < 0)
+ goto out_close_fd;
+ buf += ret;
+ count -= ret;
+ }
+
/* Event info records order is: dir fid + name, child fid */
if (fanotify_event_dir_fh_len(event)) {
info_type = info->name_len ? FAN_EVENT_INFO_TYPE_DFID_NAME :
diff --git a/include/uapi/linux/fanotify.h b/include/uapi/linux/fanotify.h
index 16402037fc7a..80040a92e9d9 100644
--- a/include/uapi/linux/fanotify.h
+++ b/include/uapi/linux/fanotify.h
@@ -124,6 +124,7 @@ 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
/* Variable length info record following event metadata */
struct fanotify_event_info_header {
@@ -149,6 +150,12 @@ struct fanotify_event_info_fid {
unsigned char handle[0];
};
+struct fanotify_event_info_error {
+ struct fanotify_event_info_header hdr;
+ __s32 error;
+ __u32 error_count;
+};
+
struct fanotify_response {
__s32 fd;
__u32 response;
--
2.32.0
