[PATCH RFC 11/15] fanotify: Introduce filesystem specific data record
STALE1972d
From: Gabriel Krisman Bertazi <hidden>
Date: 2021-04-26 18:45:07
Also in:
linux-fsdevel
Subsystem:
fanotify, filesystems (vfs and infrastructure), fsnotify: filesystem notification infrastructure, the rest · Maintainers:
Jan Kara, Alexander Viro, Christian Brauner, Linus Torvalds
Revision rfc of 7 in this series.
Revisions (7)
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 <redacted> --- 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