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Commit 1c529063 authored by Eric Paris's avatar Eric Paris
Browse files

fanotify: should_send_event needs to handle vfsmounts 



currently should_send_event in fanotify only cares about marks on inodes.
This patch extends that interface to indicate that it cares about events
that happened on vfsmounts.

Signed-off-by: default avatarEric Paris <eparis@redhat.com>
parent ca9c726e

fs/notify/fanotify/fanotify.c

+45 −11
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ 
#include <linux/fsnotify_backend.h>

#include <linux/init.h>

#include <linux/kernel.h> /* UINT_MAX */

#include <linux/mount.h>

#include <linux/types.h>



#include "fanotify.h"
@@ -99,24 +100,35 @@ static int fanotify_handle_event(struct fsnotify_group *group, struct fsnotify_e 
	return ret;

}



static bool fanotify_should_send_event(struct fsnotify_group *group, struct inode *inode,

				       struct vfsmount *mnt, __u32 mask, void *data,

				       int data_type)

static bool should_send_vfsmount_event(struct fsnotify_group *group, struct vfsmount *mnt,

				       __u32 mask)

{

	struct fsnotify_mark *fsn_mark;

	bool send;



	pr_debug("%s: group=%p inode=%p mask=%x data=%p data_type=%d\n",

		 __func__, group, inode, mask, data, data_type);

	pr_debug("%s: group=%p vfsmount=%p mask=%x\n",

		 __func__, group, mnt, mask);



	/* sorry, fanotify only gives a damn about files and dirs */

	if (!S_ISREG(inode->i_mode) &&

	    !S_ISDIR(inode->i_mode))

	fsn_mark = fsnotify_find_vfsmount_mark(group, mnt);

	if (!fsn_mark)

		return false;



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

	if (data_type != FSNOTIFY_EVENT_PATH)

		return false;

	send = (mask & fsn_mark->mask);



	/* find took a reference */

	fsnotify_put_mark(fsn_mark);



	return send;

}



static bool should_send_inode_event(struct fsnotify_group *group, struct inode *inode,

				    __u32 mask)

{

	struct fsnotify_mark *fsn_mark;

	bool send;



	pr_debug("%s: group=%p inode=%p mask=%x\n",

		 __func__, group, inode, mask);



	fsn_mark = fsnotify_find_inode_mark(group, inode);

	if (!fsn_mark)
@@ -142,6 +154,28 @@ static bool fanotify_should_send_event(struct fsnotify_group *group, struct inod 
	return send;

}



static bool fanotify_should_send_event(struct fsnotify_group *group, struct inode *to_tell,

				       struct vfsmount *mnt, __u32 mask, void *data,

				       int data_type)

{

	pr_debug("%s: group=%p to_tell=%p mnt=%p mask=%x data=%p data_type=%d\n",

		 __func__, group, to_tell, mnt, mask, data, data_type);



	/* sorry, fanotify only gives a damn about files and dirs */

	if (!S_ISREG(to_tell->i_mode) &&

	    !S_ISDIR(to_tell->i_mode))

		return false;



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

	if (data_type != FSNOTIFY_EVENT_PATH)

		return false;



	if (mnt)

		return should_send_vfsmount_event(group, mnt, mask);

	else

		return should_send_inode_event(group, to_tell, mask);

}



const struct fsnotify_ops fanotify_fsnotify_ops = {

	.handle_event = fanotify_handle_event,

	.should_send_event = fanotify_should_send_event,

include/linux/fsnotify_backend.h

+2 −0
Original line number Diff line number Diff line
@@ -368,6 +368,8 @@ extern void fsnotify_recalc_inode_mask(struct inode *inode); 
extern void fsnotify_init_mark(struct fsnotify_mark *mark, void (*free_mark)(struct fsnotify_mark *mark));

/* find (and take a reference) to a mark associated with group and inode */

extern struct fsnotify_mark *fsnotify_find_inode_mark(struct fsnotify_group *group, struct inode *inode);

/* find (and take a reference) to a mark associated with group and vfsmount */

extern struct fsnotify_mark *fsnotify_find_vfsmount_mark(struct fsnotify_group *group, struct vfsmount *mnt);

/* copy the values from old into new */

extern void fsnotify_duplicate_mark(struct fsnotify_mark *new, struct fsnotify_mark *old);

/* attach the mark to both the group and the inode */