On Fri, Aug 13, 2021 at 12:41 AM Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx> wrote: > > 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> > Reviewed-by: Amir Goldstein <amir73il@xxxxxxxxx> > --- > Changes since v5: > - Move error code here > --- > fs/notify/fanotify/fanotify.c | 1 + > fs/notify/fanotify/fanotify.h | 1 + > fs/notify/fanotify/fanotify_user.c | 36 ++++++++++++++++++++++++++++++ > include/uapi/linux/fanotify.h | 7 ++++++ > 4 files changed, 45 insertions(+) > > diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c > index f5c16ac37835..b49a474c1d7f 100644 > --- a/fs/notify/fanotify/fanotify.c > +++ b/fs/notify/fanotify/fanotify.c > @@ -745,6 +745,7 @@ static int fanotify_handle_error_event(struct fsnotify_iter_info *iter_info, > spin_unlock(&group->notification_lock); > > fee->fae.type = FANOTIFY_EVENT_TYPE_FS_ERROR; > + fee->error = report->error; > fee->fsid = fee->sb_mark->fsn_mark.connector->fsid; > > fh_len = fanotify_encode_fh_len(inode); > diff --git a/fs/notify/fanotify/fanotify.h b/fs/notify/fanotify/fanotify.h > index 158cf0c4b0bd..0cfe376c6fd9 100644 > --- a/fs/notify/fanotify/fanotify.h > +++ b/fs/notify/fanotify/fanotify.h > @@ -220,6 +220,7 @@ FANOTIFY_NE(struct fanotify_event *event) > > struct fanotify_error_event { > struct fanotify_event fae; > + s32 error; /* Error reported by the Filesystem. */ > u32 err_count; /* Suppressed errors count */ > > struct fanotify_sb_mark *sb_mark; /* Back reference to the mark. */ > diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c > index 1ab8f9d8b3ac..ca53159ce673 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); > @@ -176,6 +181,7 @@ static struct fanotify_event *fanotify_dup_error_to_stack( > error_on_stack->fae.type = FANOTIFY_EVENT_TYPE_FS_ERROR; > error_on_stack->err_count = fee->err_count; > error_on_stack->sb_mark = fee->sb_mark; > + error_on_stack->error = fee->error; > > error_on_stack->fsid = fee->fsid; > > @@ -342,6 +348,28 @@ 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) > @@ -505,6 +533,14 @@ 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 >