From e9e0c8903009477b630e37a8b6364b26a00720da Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Thu, 10 Jan 2019 19:04:34 +0200 Subject: fanotify: encode file identifier for FAN_REPORT_FID When user requests the flag FAN_REPORT_FID in fanotify_init(), a unique file identifier of the event target object will be reported with the event. The file identifier includes the filesystem's fsid (i.e. from statfs(2)) and an NFS file handle of the file (i.e. from name_to_handle_at(2)). The file identifier makes holding the path reference and passing a file descriptor to user redundant, so those are disabled in a group with FAN_REPORT_FID. Encode fid and store it in event for a group with FAN_REPORT_FID. Up to 12 bytes of file handle on 32bit arch (16 bytes on 64bit arch) are stored inline in fanotify_event struct. Larger file handles are stored in an external allocated buffer. On failure to encode fid, we print a warning and queue the event without the fid information. [JK: Fold part of later patched into this one to use exportfs_encode_inode_fh() right away] Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara --- include/uapi/linux/fanotify.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/fanotify.h b/include/uapi/linux/fanotify.h index 909c98fcace2..d07f3cbc2786 100644 --- a/include/uapi/linux/fanotify.h +++ b/include/uapi/linux/fanotify.h @@ -44,6 +44,7 @@ /* Flags to determine fanotify event format */ #define FAN_REPORT_TID 0x00000100 /* event->pid is thread id */ +#define FAN_REPORT_FID 0x00000200 /* Report unique file id */ /* Deprecated - do not use this in programs and do not add new flags here! */ #define FAN_ALL_INIT_FLAGS (FAN_CLOEXEC | FAN_NONBLOCK | \ -- cgit v1.2.3 From 5e469c830fdb5a1ebaa69b375b87f583326fd296 Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Thu, 10 Jan 2019 19:04:35 +0200 Subject: fanotify: copy event fid info to user If group requested FAN_REPORT_FID and event has file identifier, copy that information to user reading the event after event metadata. fid information is formatted as struct fanotify_event_info_fid that includes a generic header struct fanotify_event_info_header, so that other info types could be defined in the future using the same header. metadata->event_len includes the length of the fid information. The fid information includes the filesystem's fsid (see statfs(2)) followed by an NFS file handle of the file that could be passed as an argument to open_by_handle_at(2). Cc: Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara --- include/uapi/linux/fanotify.h | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/fanotify.h b/include/uapi/linux/fanotify.h index d07f3cbc2786..959ae2bdc7ca 100644 --- a/include/uapi/linux/fanotify.h +++ b/include/uapi/linux/fanotify.h @@ -107,6 +107,26 @@ struct fanotify_event_metadata { __s32 pid; }; +#define FAN_EVENT_INFO_TYPE_FID 1 + +/* Variable length info record following event metadata */ +struct fanotify_event_info_header { + __u8 info_type; + __u8 pad; + __u16 len; +}; + +/* Unique file identifier info record */ +struct fanotify_event_info_fid { + struct fanotify_event_info_header hdr; + __kernel_fsid_t fsid; + /* + * Following is an opaque struct file_handle that can be passed as + * an argument to open_by_handle_at(2). + */ + unsigned char handle[0]; +}; + struct fanotify_response { __s32 fd; __u32 response; -- cgit v1.2.3 From 235328d1fa4251c6dcb32351219bb553a58838d2 Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Thu, 10 Jan 2019 19:04:43 +0200 Subject: fanotify: add support for create/attrib/move/delete events Add support for events with data type FSNOTIFY_EVENT_INODE (e.g. create/attrib/move/delete) for inode and filesystem mark types. The "inode" events do not carry enough information (i.e. path) to report event->fd, so we do not allow setting a mask for those events unless group supports reporting fid. The "inode" events are not supported on a mount mark, because they do not carry enough information (i.e. path) to be filtered by mount point. The "dirent" events (create/move/delete) report the fid of the parent directory where events took place without specifying the filename of the child. In the future, fanotify may get support for reporting filename information for those events. Cc: Signed-off-by: Amir Goldstein Signed-off-by: Jan Kara --- include/uapi/linux/fanotify.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/fanotify.h b/include/uapi/linux/fanotify.h index 959ae2bdc7ca..b9effa6f8503 100644 --- a/include/uapi/linux/fanotify.h +++ b/include/uapi/linux/fanotify.h @@ -7,9 +7,16 @@ /* the following events that user-space can register for */ #define FAN_ACCESS 0x00000001 /* File was accessed */ #define FAN_MODIFY 0x00000002 /* File was modified */ +#define FAN_ATTRIB 0x00000004 /* Metadata changed */ #define FAN_CLOSE_WRITE 0x00000008 /* Writtable file closed */ #define FAN_CLOSE_NOWRITE 0x00000010 /* Unwrittable file closed */ #define FAN_OPEN 0x00000020 /* File was opened */ +#define FAN_MOVED_FROM 0x00000040 /* File was moved from X */ +#define FAN_MOVED_TO 0x00000080 /* File was moved to Y */ +#define FAN_CREATE 0x00000100 /* Subfile was created */ +#define FAN_DELETE 0x00000200 /* Subfile was deleted */ +#define FAN_DELETE_SELF 0x00000400 /* Self was deleted */ +#define FAN_MOVE_SELF 0x00000800 /* Self was moved */ #define FAN_OPEN_EXEC 0x00001000 /* File was opened for exec */ #define FAN_Q_OVERFLOW 0x00004000 /* Event queued overflowed */ @@ -24,6 +31,7 @@ /* helper events */ #define FAN_CLOSE (FAN_CLOSE_WRITE | FAN_CLOSE_NOWRITE) /* close */ +#define FAN_MOVE (FAN_MOVED_FROM | FAN_MOVED_TO) /* moves */ /* flags used for fanotify_init() */ #define FAN_CLOEXEC 0x00000001 -- cgit v1.2.3