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Commit 3bcf3860 authored by Eric Paris's avatar Eric Paris
Browse files

fsnotify: store struct file not struct path 



Al explains that calling dentry_open() with a mnt/dentry pair is only
garunteed to be safe if they are already used in an open struct file.  To
make sure this is the case don't store and use a struct path in fsnotify,
always use a struct file.

Signed-off-by: default avatarEric Paris <eparis@redhat.com>
parent f70ab54c

fs/notify/fanotify/fanotify.c

+4 −4
Original line number Diff line number Diff line
@@ -17,9 +17,9 @@ static bool should_merge(struct fsnotify_event *old, struct fsnotify_event *new) 
	    old->data_type == new->data_type &&

	    old->tgid == new->tgid) {

		switch (old->data_type) {

		case (FSNOTIFY_EVENT_PATH):

			if ((old->path.mnt == new->path.mnt) &&

			    (old->path.dentry == new->path.dentry))

		case (FSNOTIFY_EVENT_FILE):

			if ((old->file->f_path.mnt == new->file->f_path.mnt) &&

			    (old->file->f_path.dentry == new->file->f_path.dentry))

				return true;

		case (FSNOTIFY_EVENT_NONE):

			return true;
@@ -226,7 +226,7 @@ static bool fanotify_should_send_event(struct fsnotify_group *group, struct inod 
		return false;



	/* if we don't have enough info to send an event to userspace say no */

	if (data_type != FSNOTIFY_EVENT_PATH)

	if (data_type != FSNOTIFY_EVENT_FILE)

		return false;



	if (mnt)

fs/notify/fanotify/fanotify_user.c

+3 −3
Original line number Diff line number Diff line
@@ -65,7 +65,7 @@ static int create_fd(struct fsnotify_group *group, struct fsnotify_event *event) 
	if (client_fd < 0)

		return client_fd;



	if (event->data_type != FSNOTIFY_EVENT_PATH) {

	if (event->data_type != FSNOTIFY_EVENT_FILE) {

		WARN_ON(1);

		put_unused_fd(client_fd);

		return -EINVAL;
@@ -75,8 +75,8 @@ static int create_fd(struct fsnotify_group *group, struct fsnotify_event *event) 
	 * we need a new file handle for the userspace program so it can read even if it was

	 * originally opened O_WRONLY.

	 */

	dentry = dget(event->path.dentry);

	mnt = mntget(event->path.mnt);

	dentry = dget(event->file->f_path.dentry);

	mnt = mntget(event->file->f_path.mnt);

	/* it's possible this event was an overflow event.  in that case dentry and mnt

	 * are NULL;  That's fine, just don't call dentry open */

	if (dentry && mnt)

fs/notify/fsnotify.c

+8 −8
Original line number Diff line number Diff line
@@ -84,7 +84,7 @@ void __fsnotify_update_child_dentry_flags(struct inode *inode) 
}



/* Notify this dentry's parent about a child's events. */

void __fsnotify_parent(struct path *path, struct dentry *dentry, __u32 mask)

void __fsnotify_parent(struct file *file, struct dentry *dentry, __u32 mask)

{

	struct dentry *parent;

	struct inode *p_inode;
@@ -92,7 +92,7 @@ void __fsnotify_parent(struct path *path, struct dentry *dentry, __u32 mask) 
	bool should_update_children = false;



	if (!dentry)

		dentry = path->dentry;

		dentry = file->f_path.dentry;



	if (!(dentry->d_flags & DCACHE_FSNOTIFY_PARENT_WATCHED))

		return;
@@ -124,8 +124,8 @@ void __fsnotify_parent(struct path *path, struct dentry *dentry, __u32 mask) 
		 * specifies these are events which came from a child. */

		mask |= FS_EVENT_ON_CHILD;



		if (path)

			fsnotify(p_inode, mask, path, FSNOTIFY_EVENT_PATH,

		if (file)

			fsnotify(p_inode, mask, file, FSNOTIFY_EVENT_FILE,

				 dentry->d_name.name, 0);

		else

			fsnotify(p_inode, mask, dentry->d_inode, FSNOTIFY_EVENT_INODE,
@@ -154,10 +154,10 @@ void __fsnotify_flush_ignored_mask(struct inode *inode, void *data, int data_is) 
		spin_unlock(&inode->i_lock);

	}



	if (data_is == FSNOTIFY_EVENT_PATH) {

	if (data_is == FSNOTIFY_EVENT_FILE) {

		struct vfsmount *mnt;



		mnt = ((struct path *)data)->mnt;

		mnt = ((struct file *)data)->f_path.mnt;

		if (mnt && !hlist_empty(&mnt->mnt_fsnotify_marks)) {

			spin_lock(&mnt->mnt_root->d_lock);

			hlist_for_each_entry(mark, node, &mnt->mnt_fsnotify_marks, m.m_list) {
@@ -228,8 +228,8 @@ int fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is, 
	    !(test_mask & fsnotify_vfsmount_mask))

		return 0;

 

	if (data_is == FSNOTIFY_EVENT_PATH)

		mnt = ((struct path *)data)->mnt;

	if (data_is == FSNOTIFY_EVENT_FILE)

		mnt = ((struct file *)data)->f_path.mnt;



	/* if this inode's directed listeners don't care and nothing on the vfsmount

	 * listeners list cares, nothing to do */

fs/notify/inotify/inotify_fsnotify.c

+6 −6
Original line number Diff line number Diff line
@@ -52,9 +52,9 @@ static bool event_compare(struct fsnotify_event *old, struct fsnotify_event *new 
			    !strcmp(old->file_name, new->file_name))

				return true;

			break;

		case (FSNOTIFY_EVENT_PATH):

			if ((old->path.mnt == new->path.mnt) &&

			    (old->path.dentry == new->path.dentry))

		case (FSNOTIFY_EVENT_FILE):

			if ((old->file->f_path.mnt == new->file->f_path.mnt) &&

			    (old->file->f_path.dentry == new->file->f_path.dentry))

				return true;

			break;

		case (FSNOTIFY_EVENT_NONE):
@@ -165,10 +165,10 @@ static bool inotify_should_send_event(struct fsnotify_group *group, struct inode 
	send = (fsn_mark->mask & mask);



	if (send && (fsn_mark->mask & FS_EXCL_UNLINK) &&

	    (data_type == FSNOTIFY_EVENT_PATH)) {

		struct path *path  = data;

	    (data_type == FSNOTIFY_EVENT_FILE)) {

		struct file *file  = data;



		if (d_unlinked(path->dentry))

		if (d_unlinked(file->f_path.dentry))

			send = false;

	}

fs/notify/notification.c

+9 −11
Original line number Diff line number Diff line
@@ -31,6 +31,7 @@ 
 * allocated and used.

 */



#include <linux/file.h>

#include <linux/fs.h>

#include <linux/init.h>

#include <linux/kernel.h>
@@ -89,8 +90,8 @@ void fsnotify_put_event(struct fsnotify_event *event) 
	if (atomic_dec_and_test(&event->refcnt)) {

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



		if (event->data_type == FSNOTIFY_EVENT_PATH)

			path_put(&event->path);

		if (event->data_type == FSNOTIFY_EVENT_FILE)

			fput(event->file);



		BUG_ON(!list_empty(&event->private_data_list));
@@ -375,8 +376,8 @@ struct fsnotify_event *fsnotify_clone_event(struct fsnotify_event *old_event) 
		}

	}

	event->tgid = get_pid(old_event->tgid);

	if (event->data_type == FSNOTIFY_EVENT_PATH)

		path_get(&event->path);

	if (event->data_type == FSNOTIFY_EVENT_FILE)

		get_file(event->file);



	return event;

}
@@ -423,11 +424,9 @@ struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask, 
	event->data_type = data_type;



	switch (data_type) {

	case FSNOTIFY_EVENT_PATH: {

		struct path *path = data;

		event->path.dentry = path->dentry;

		event->path.mnt = path->mnt;

		path_get(&event->path);

	case FSNOTIFY_EVENT_FILE: {

		event->file = data;

		get_file(event->file);

		break;

	}

	case FSNOTIFY_EVENT_INODE:
@@ -435,8 +434,7 @@ struct fsnotify_event *fsnotify_create_event(struct inode *to_tell, __u32 mask, 
		break;

	case FSNOTIFY_EVENT_NONE:

		event->inode = NULL;

		event->path.dentry = NULL;

		event->path.mnt = NULL;

		event->file = NULL;

		break;

	default:

		BUG();