Commit 3cf984e9 authored by Amir Goldstein's avatar Amir Goldstein Committed by Jan Kara
Browse files

fanotify: support secondary dir fh and name in fanotify_info 

Allow storing a secondary dir fh and name tupple in fanotify_info.
This will be used to store the new parent and name information in
FAN_RENAME event.

Link: https://lore.kernel.org/r/20211129201537.1932819-8-amir73il@gmail.com


Signed-off-by: default avatarAmir Goldstein <amir73il@gmail.com>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
parent 1a9515ac

fs/notify/fanotify/fanotify.c

+16 −4
Original line number Diff line number Diff line
@@ -76,8 +76,10 @@ static bool fanotify_info_equal(struct fanotify_info *info1, 
				struct fanotify_info *info2)

{

	if (info1->dir_fh_totlen != info2->dir_fh_totlen ||

	    info1->dir2_fh_totlen != info2->dir2_fh_totlen ||

	    info1->file_fh_totlen != info2->file_fh_totlen ||

	    info1->name_len != info2->name_len)

	    info1->name_len != info2->name_len ||

	    info1->name2_len != info2->name2_len)

		return false;



	if (info1->dir_fh_totlen &&
@@ -85,14 +87,24 @@ static bool fanotify_info_equal(struct fanotify_info *info1, 
			       fanotify_info_dir_fh(info2)))

		return false;



	if (info1->dir2_fh_totlen &&

	    !fanotify_fh_equal(fanotify_info_dir2_fh(info1),

			       fanotify_info_dir2_fh(info2)))

		return false;



	if (info1->file_fh_totlen &&

	    !fanotify_fh_equal(fanotify_info_file_fh(info1),

			       fanotify_info_file_fh(info2)))

		return false;



	return !info1->name_len ||

		!memcmp(fanotify_info_name(info1), fanotify_info_name(info2),

			info1->name_len);

	if (info1->name_len &&

	    memcmp(fanotify_info_name(info1), fanotify_info_name(info2),

		   info1->name_len))

		return false;



	return !info1->name2_len ||

		!memcmp(fanotify_info_name2(info1), fanotify_info_name2(info2),

			info1->name2_len);

}



static bool fanotify_name_event_equal(struct fanotify_name_event *fne1,

fs/notify/fanotify/fanotify.h

+71 −8
Original line number Diff line number Diff line
@@ -40,31 +40,45 @@ struct fanotify_fh { 
struct fanotify_info {

	/* size of dir_fh/file_fh including fanotify_fh hdr size */

	u8 dir_fh_totlen;

	u8 dir2_fh_totlen;

	u8 file_fh_totlen;

	u8 name_len;

	u8 pad;

	u8 name2_len;

	u8 pad[3];

	unsigned char buf[];

	/*

	 * (struct fanotify_fh) dir_fh starts at buf[0]

	 * (optional) file_fh starts at buf[dir_fh_totlen]

	 * name starts at buf[dir_fh_totlen + file_fh_totlen]

	 * (optional) dir2_fh starts at buf[dir_fh_totlen]

	 * (optional) file_fh starts at buf[dir_fh_totlen + dir2_fh_totlen]

	 * name starts at buf[dir_fh_totlen + dir2_fh_totlen + file_fh_totlen]

	 * ...

	 */

#define FANOTIFY_DIR_FH_SIZE(info)	((info)->dir_fh_totlen)

#define FANOTIFY_DIR2_FH_SIZE(info)	((info)->dir2_fh_totlen)

#define FANOTIFY_FILE_FH_SIZE(info)	((info)->file_fh_totlen)

#define FANOTIFY_NAME_SIZE(info)	((info)->name_len + 1)

#define FANOTIFY_NAME2_SIZE(info)	((info)->name2_len + 1)



#define FANOTIFY_DIR_FH_OFFSET(info)	0

#define FANOTIFY_FILE_FH_OFFSET(info) \

#define FANOTIFY_DIR2_FH_OFFSET(info) \

	(FANOTIFY_DIR_FH_OFFSET(info) + FANOTIFY_DIR_FH_SIZE(info))

#define FANOTIFY_FILE_FH_OFFSET(info) \

	(FANOTIFY_DIR2_FH_OFFSET(info) + FANOTIFY_DIR2_FH_SIZE(info))

#define FANOTIFY_NAME_OFFSET(info) \

	(FANOTIFY_FILE_FH_OFFSET(info) + FANOTIFY_FILE_FH_SIZE(info))

#define FANOTIFY_NAME2_OFFSET(info) \

	(FANOTIFY_NAME_OFFSET(info) + FANOTIFY_NAME_SIZE(info))



#define FANOTIFY_DIR_FH_BUF(info) \

	((info)->buf + FANOTIFY_DIR_FH_OFFSET(info))

#define FANOTIFY_DIR2_FH_BUF(info) \

	((info)->buf + FANOTIFY_DIR2_FH_OFFSET(info))

#define FANOTIFY_FILE_FH_BUF(info) \

	((info)->buf + FANOTIFY_FILE_FH_OFFSET(info))

#define FANOTIFY_NAME_BUF(info) \

	((info)->buf + FANOTIFY_NAME_OFFSET(info))

#define FANOTIFY_NAME2_BUF(info) \

	((info)->buf + FANOTIFY_NAME2_OFFSET(info))

} __aligned(4);



static inline bool fanotify_fh_has_ext_buf(struct fanotify_fh *fh)
@@ -106,6 +120,20 @@ static inline struct fanotify_fh *fanotify_info_dir_fh(struct fanotify_info *inf 
	return (struct fanotify_fh *)FANOTIFY_DIR_FH_BUF(info);

}



static inline int fanotify_info_dir2_fh_len(struct fanotify_info *info)

{

	if (!info->dir2_fh_totlen ||

	    WARN_ON_ONCE(info->dir2_fh_totlen < FANOTIFY_FH_HDR_LEN))

		return 0;



	return info->dir2_fh_totlen - FANOTIFY_FH_HDR_LEN;

}



static inline struct fanotify_fh *fanotify_info_dir2_fh(struct fanotify_info *info)

{

	return (struct fanotify_fh *)FANOTIFY_DIR2_FH_BUF(info);

}



static inline int fanotify_info_file_fh_len(struct fanotify_info *info)

{

	if (!info->file_fh_totlen ||
@@ -128,31 +156,55 @@ static inline char *fanotify_info_name(struct fanotify_info *info) 
	return FANOTIFY_NAME_BUF(info);

}



static inline char *fanotify_info_name2(struct fanotify_info *info)

{

	if (!info->name2_len)

		return NULL;



	return FANOTIFY_NAME2_BUF(info);

}



static inline void fanotify_info_init(struct fanotify_info *info)

{

	BUILD_BUG_ON(FANOTIFY_FH_HDR_LEN + MAX_HANDLE_SZ > U8_MAX);

	BUILD_BUG_ON(NAME_MAX > U8_MAX);



	info->dir_fh_totlen = 0;

	info->dir2_fh_totlen = 0;

	info->file_fh_totlen = 0;

	info->name_len = 0;

	info->name2_len = 0;

}



/* These set/copy helpers MUST be called by order */

static inline void fanotify_info_set_dir_fh(struct fanotify_info *info,

					    unsigned int totlen)

{

	if (WARN_ON_ONCE(info->file_fh_totlen > 0) ||

	    WARN_ON_ONCE(info->name_len > 0))

	if (WARN_ON_ONCE(info->dir2_fh_totlen > 0) ||

	    WARN_ON_ONCE(info->file_fh_totlen > 0) ||

	    WARN_ON_ONCE(info->name_len > 0) ||

	    WARN_ON_ONCE(info->name2_len > 0))

		return;



	info->dir_fh_totlen = totlen;

}



static inline void fanotify_info_set_dir2_fh(struct fanotify_info *info,

					     unsigned int totlen)

{

	if (WARN_ON_ONCE(info->file_fh_totlen > 0) ||

	    WARN_ON_ONCE(info->name_len > 0) ||

	    WARN_ON_ONCE(info->name2_len > 0))

		return;



	info->dir2_fh_totlen = totlen;

}



static inline void fanotify_info_set_file_fh(struct fanotify_info *info,

					     unsigned int totlen)

{

	if (WARN_ON_ONCE(info->name_len > 0))

	if (WARN_ON_ONCE(info->name_len > 0) ||

	    WARN_ON_ONCE(info->name2_len > 0))

		return;



	info->file_fh_totlen = totlen;
@@ -161,13 +213,24 @@ static inline void fanotify_info_set_file_fh(struct fanotify_info *info, 
static inline void fanotify_info_copy_name(struct fanotify_info *info,

					   const struct qstr *name)

{

	if (WARN_ON_ONCE(name->len > NAME_MAX))

	if (WARN_ON_ONCE(name->len > NAME_MAX) ||

	    WARN_ON_ONCE(info->name2_len > 0))

		return;



	info->name_len = name->len;

	strcpy(fanotify_info_name(info), name->name);

}



static inline void fanotify_info_copy_name2(struct fanotify_info *info,

					    const struct qstr *name)

{

	if (WARN_ON_ONCE(name->len > NAME_MAX))

		return;



	info->name2_len = name->len;

	strcpy(fanotify_info_name2(info), name->name);

}



/*

 * Common structure for fanotify events. Concrete structs are allocated in

 * fanotify_handle_event() and freed when the information is retrieved by

fs/notify/fanotify/fanotify_user.c

+1 −2
Original line number Diff line number Diff line
@@ -332,11 +332,10 @@ static int process_access_response(struct fsnotify_group *group, 
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_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_ERROR_INFO_LEN;



	if (WARN_ON(count < info.hdr.len))