fanotify: add basic support for FAN_REPORT_DIR_FID (83b7a598) · Commits · 戴 / test

fs/notify/fanotify/fanotify.c

+32 −2

Original line number	Diff line number	Diff line
		@@ -223,7 +223,7 @@ out:
		static u32 fanotify_group_event_mask(struct fsnotify_group *group,
		struct fsnotify_iter_info *iter_info,
		u32 event_mask, const void *data,
		int data_type)
		int data_type, struct inode *dir)
		{
		__u32 marks_mask = 0, marks_ignored_mask = 0;
		__u32 test_mask, user_mask = FANOTIFY_OUTGOING_EVENTS \|
		@@ -243,6 +243,10 @@ static u32 fanotify_group_event_mask(struct fsnotify_group *group,
		/* Path type events are only relevant for files and dirs */
		if (!d_is_reg(path->dentry) && !d_can_lookup(path->dentry))
		return 0;
		} else if (!(fid_mode & FAN_REPORT_FID)) {
		/* Do we have a directory inode to report? */
		if (!dir && !(event_mask & FS_ISDIR))
		return 0;
		}

		fsnotify_foreach_obj_type(type) {
		@@ -396,6 +400,28 @@ static struct inode fanotify_fid_inode(u32 event_mask, const void data,
		return fsnotify_data_inode(data, data_type);
		}

		/*
		* The inode to use as identifier when reporting dir fid depends on the event.
		* Report the modified directory inode on dirent modification events.
		* Report the "victim" inode if "victim" is a directory.
		* Report the parent inode if "victim" is not a directory and event is
		* reported to parent.
		* Otherwise, do not report dir fid.
		*/
		static struct inode fanotify_dfid_inode(u32 event_mask, const void data,
		int data_type, struct inode *dir)
		{
		struct inode *inode = fsnotify_data_inode(data, data_type);

		if (event_mask & ALL_FSNOTIFY_DIRENT_EVENTS)
		return dir;

		if (S_ISDIR(inode->i_mode))
		return inode;

		return dir;
		}

		static struct fanotify_event fanotify_alloc_path_event(const struct path path,
		gfp_t gfp)
		{
		@@ -491,10 +517,14 @@ static struct fanotify_event fanotify_alloc_event(struct fsnotify_group group,
		struct fanotify_event *event = NULL;
		gfp_t gfp = GFP_KERNEL_ACCOUNT;
		struct inode *id = fanotify_fid_inode(mask, data, data_type, dir);
		struct inode *dirid = fanotify_dfid_inode(mask, data, data_type, dir);
		const struct path *path = fsnotify_data_path(data, data_type);
		unsigned int fid_mode = FAN_GROUP_FLAG(group, FANOTIFY_FID_BITS);
		bool name_event = false;

		if ((fid_mode & FAN_REPORT_DIR_FID) && dirid)
		id = dirid;

		/*
		* For queues with unlimited length lost events are not expected and
		* can possibly have security implications. Avoid losing events when
		@@ -605,7 +635,7 @@ static int fanotify_handle_event(struct fsnotify_group *group, u32 mask,
		BUILD_BUG_ON(HWEIGHT32(ALL_FANOTIFY_EVENT_BITS) != 19);

		mask = fanotify_group_event_mask(group, iter_info, mask, data,
		data_type);
		data_type, dir);
		if (!mask)
		return 0;

fs/notify/fanotify/fanotify_user.c

+61 −10

Original line number	Diff line number	Diff line
		@@ -216,7 +216,7 @@ static int process_access_response(struct fsnotify_group *group,
		}

		static int copy_info_to_user(__kernel_fsid_t fsid, struct fanotify_fh fh,
		const char *name, size_t name_len,
		int info_type, const char *name, size_t name_len,
		char __user *buf, size_t count)
		{
		struct fanotify_event_info_fid info = { };
		@@ -229,7 +229,7 @@ static int copy_info_to_user(__kernel_fsid_t fsid, struct fanotify_fh fh,
		pr_debug("%s: fh_len=%zu name_len=%zu, info_len=%zu, count=%zu\n",
		__func__, fh_len, name_len, info_len, count);

		if (!fh_len \|\| (name && !name_len))
		if (!fh_len)
		return 0;

		if (WARN_ON_ONCE(len < sizeof(info) \|\| len > count))
		@@ -239,8 +239,21 @@ static int copy_info_to_user(__kernel_fsid_t fsid, struct fanotify_fh fh,
		* Copy event info fid header followed by variable sized file handle
		* and optionally followed by variable sized filename.
		*/
		info.hdr.info_type = name_len ? FAN_EVENT_INFO_TYPE_DFID_NAME :
		FAN_EVENT_INFO_TYPE_FID;
		switch (info_type) {
		case FAN_EVENT_INFO_TYPE_FID:
		case FAN_EVENT_INFO_TYPE_DFID:
		if (WARN_ON_ONCE(name_len))
		return -EFAULT;
		break;
		case FAN_EVENT_INFO_TYPE_DFID_NAME:
		if (WARN_ON_ONCE(!name \|\| !name_len))
		return -EFAULT;
		break;
		default:
		return -EFAULT;
		}

		info.hdr.info_type = info_type;
		info.hdr.len = len;
		info.fsid = *fsid;
		if (copy_to_user(buf, &info, sizeof(info)))
		@@ -304,8 +317,10 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group,
		struct fanotify_event_metadata metadata;
		struct path *path = fanotify_event_path(event);
		struct fanotify_info *info = fanotify_event_info(event);
		unsigned int fid_mode = FAN_GROUP_FLAG(group, FANOTIFY_FID_BITS);
		struct file *f = NULL;
		int ret, fd = FAN_NOFD;
		int info_type = 0;

		pr_debug("%s: group=%p event=%p\n", __func__, group, event);

		@@ -346,9 +361,10 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group,

		/* Event info records order is: dir fid + name, child fid */
		if (fanotify_event_dir_fh_len(event)) {
		info_type = FAN_EVENT_INFO_TYPE_DFID_NAME;
		ret = copy_info_to_user(fanotify_event_fsid(event),
		fanotify_info_dir_fh(info),
		fanotify_info_name(info),
		info_type, fanotify_info_name(info),
		info->name_len, buf, count);
		if (ret < 0)
		return ret;
		@@ -358,9 +374,33 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group,
		}

		if (fanotify_event_object_fh_len(event)) {
		if (fid_mode == FAN_REPORT_FID \|\| info_type) {
		/*
		* With only group flag FAN_REPORT_FID only type FID is
		* reported. Second info record type is always FID.
		*/
		info_type = FAN_EVENT_INFO_TYPE_FID;
		} else if ((event->mask & ALL_FSNOTIFY_DIRENT_EVENTS) \|\|
		(event->mask & FAN_ONDIR)) {
		/*
		* With group flag FAN_REPORT_DIR_FID, a single info
		* record has type DFID for directory entry modification
		* event and for event on a directory.
		*/
		info_type = FAN_EVENT_INFO_TYPE_DFID;
		} else {
		/*
		* With group flags FAN_REPORT_DIR_FID\|FAN_REPORT_FID,
		* a single info record has type FID for event on a
		* non-directory, when there is no directory to report.
		* For example, on FAN_DELETE_SELF event.
		*/
		info_type = FAN_EVENT_INFO_TYPE_FID;
		}

		ret = copy_info_to_user(fanotify_event_fsid(event),
		fanotify_event_object_fh(event),
		NULL, 0, buf, count);
		info_type, NULL, 0, buf, count);
		if (ret < 0)
		return ret;

		@@ -861,6 +901,8 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
		struct fsnotify_group *group;
		int f_flags, fd;
		struct user_struct *user;
		unsigned int fid_mode = flags & FANOTIFY_FID_BITS;
		unsigned int class = flags & FANOTIFY_CLASS_BITS;

		pr_debug("%s: flags=%x event_f_flags=%x\n",
		__func__, flags, event_f_flags);
		@@ -887,10 +929,19 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
		return -EINVAL;
		}

		if ((flags & FANOTIFY_FID_BITS) &&
		(flags & FANOTIFY_CLASS_BITS) != FAN_CLASS_NOTIF)
		if (fid_mode && class != FAN_CLASS_NOTIF)
		return -EINVAL;

		/* Reporting either object fid or dir fid */
		switch (fid_mode) {
		case 0:
		case FAN_REPORT_FID:
		case FAN_REPORT_DIR_FID:
		break;
		default:
		return -EINVAL;
		}

		user = get_current_user();
		if (atomic_read(&user->fanotify_listeners) > FANOTIFY_DEFAULT_MAX_LISTENERS) {
		free_uid(user);
		@@ -926,7 +977,7 @@ SYSCALL_DEFINE2(fanotify_init, unsigned int, flags, unsigned int, event_f_flags)
		group->fanotify_data.f_flags = event_f_flags;
		init_waitqueue_head(&group->fanotify_data.access_waitq);
		INIT_LIST_HEAD(&group->fanotify_data.access_list);
		switch (flags & FANOTIFY_CLASS_BITS) {
		switch (class) {
		case FAN_CLASS_NOTIF:
		group->priority = FS_PRIO_0;
		break;
		@@ -1236,7 +1287,7 @@ COMPAT_SYSCALL_DEFINE6(fanotify_mark,
		*/
		static int __init fanotify_user_setup(void)
		{
		BUILD_BUG_ON(HWEIGHT32(FANOTIFY_INIT_FLAGS) != 8);
		BUILD_BUG_ON(HWEIGHT32(FANOTIFY_INIT_FLAGS) != 9);
		BUILD_BUG_ON(HWEIGHT32(FANOTIFY_MARK_FLAGS) != 9);

		fanotify_mark_cache = KMEM_CACHE(fsnotify_mark,

include/linux/fanotify.h

+1 −1

Original line number	Diff line number	Diff line
		@@ -18,7 +18,7 @@
		#define FANOTIFY_CLASS_BITS (FAN_CLASS_NOTIF \| FAN_CLASS_CONTENT \| \
		FAN_CLASS_PRE_CONTENT)

		#define FANOTIFY_FID_BITS (FAN_REPORT_FID)
		#define FANOTIFY_FID_BITS (FAN_REPORT_FID \| FAN_REPORT_DIR_FID)

		#define FANOTIFY_INIT_FLAGS (FANOTIFY_CLASS_BITS \| FANOTIFY_FID_BITS \| \
		FAN_REPORT_TID \| \

include/uapi/linux/fanotify.h

+7 −4

Original line number	Diff line number	Diff line
		@@ -53,6 +53,7 @@
		/* 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 */
		#define FAN_REPORT_DIR_FID 0x00000400 /* Report unique directory id */

		/* Deprecated - do not use this in programs and do not add new flags here! */
		#define FAN_ALL_INIT_FLAGS (FAN_CLOEXEC \| FAN_NONBLOCK \| \
		@@ -117,6 +118,7 @@ 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

		/* Variable length info record following event metadata */
		struct fanotify_event_info_header {
		@@ -126,10 +128,11 @@ struct fanotify_event_info_header {
		};

		/*
		* Unique file identifier info record. This is used both for
		* FAN_EVENT_INFO_TYPE_FID records and for FAN_EVENT_INFO_TYPE_DFID_NAME
		* records. For FAN_EVENT_INFO_TYPE_DFID_NAME there is additionally a null
		* terminated name immediately after the file handle.
		* Unique file identifier info record.
		* This structure is used for records of types FAN_EVENT_INFO_TYPE_FID,
		* FAN_EVENT_INFO_TYPE_DFID and FAN_EVENT_INFO_TYPE_DFID_NAME.
		* For FAN_EVENT_INFO_TYPE_DFID_NAME there is additionally a null terminated
		* name immediately after the file handle.
		*/
		struct fanotify_event_info_fid {
		struct fanotify_event_info_header hdr;

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