Commit a9dc971d authored by Amy Griffis's avatar Amy Griffis Committed by Al Viro
Browse files

[PATCH] inotify (3/5): add interfaces to kernel API 



Add inotify_init_watch() so caller can use inotify_watch refcounts
before calling inotify_add_watch().

Add inotify_find_watch() to find an existing watch for an (ih,inode)
pair.  This is similar to inotify_find_update_watch(), but does not
update the watch's mask if one is found.

Add inotify_rm_watch() to remove a watch via the watch pointer instead
of the watch descriptor.

Signed-off-by: default avatarAmy Griffis <amy.griffis@hp.com>
Acked-by: default avatarRobert Love <rml@novell.com>
Acked-by: default avatarJohn McCutchan <john@johnmccutchan.com>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 7c297722

fs/inotify.c

+58 −6
Original line number Diff line number Diff line
@@ -467,6 +467,19 @@ struct inotify_handle *inotify_init(const struct inotify_operations *ops) 
}

EXPORT_SYMBOL_GPL(inotify_init);



/**

 * inotify_init_watch - initialize an inotify watch

 * @watch: watch to initialize

 */

void inotify_init_watch(struct inotify_watch *watch)

{

	INIT_LIST_HEAD(&watch->h_list);

	INIT_LIST_HEAD(&watch->i_list);

	atomic_set(&watch->count, 0);

	get_inotify_watch(watch); /* initial get */

}

EXPORT_SYMBOL_GPL(inotify_init_watch);



/**

 * inotify_destroy - clean up and destroy an inotify instance

 * @ih: inotify handle
@@ -514,6 +527,37 @@ void inotify_destroy(struct inotify_handle *ih) 
}

EXPORT_SYMBOL_GPL(inotify_destroy);



/**

 * inotify_find_watch - find an existing watch for an (ih,inode) pair

 * @ih: inotify handle

 * @inode: inode to watch

 * @watchp: pointer to existing inotify_watch

 *

 * Caller must pin given inode (via nameidata).

 */

s32 inotify_find_watch(struct inotify_handle *ih, struct inode *inode,

		       struct inotify_watch **watchp)

{

	struct inotify_watch *old;

	int ret = -ENOENT;



	mutex_lock(&inode->inotify_mutex);

	mutex_lock(&ih->mutex);



	old = inode_find_handle(inode, ih);

	if (unlikely(old)) {

		get_inotify_watch(old); /* caller must put watch */

		*watchp = old;

		ret = old->wd;

	}



	mutex_unlock(&ih->mutex);

	mutex_unlock(&inode->inotify_mutex);



	return ret;

}

EXPORT_SYMBOL_GPL(inotify_find_watch);



/**

 * inotify_find_update_watch - find and update the mask of an existing watch

 * @ih: inotify handle
@@ -593,10 +637,6 @@ s32 inotify_add_watch(struct inotify_handle *ih, struct inotify_watch *watch, 
		goto out;

	ret = watch->wd;



	atomic_set(&watch->count, 0);

	INIT_LIST_HEAD(&watch->h_list);

	INIT_LIST_HEAD(&watch->i_list);



	/* save a reference to handle and bump the count to make it official */

	get_inotify_handle(ih);

	watch->ih = ih;
@@ -607,8 +647,6 @@ s32 inotify_add_watch(struct inotify_handle *ih, struct inotify_watch *watch, 
	 */

	watch->inode = igrab(inode);



	get_inotify_watch(watch); /* initial get */



	if (!inotify_inode_watched(inode))

		set_dentry_child_flags(inode, 1);
@@ -659,6 +697,20 @@ int inotify_rm_wd(struct inotify_handle *ih, u32 wd) 
}

EXPORT_SYMBOL_GPL(inotify_rm_wd);



/**

 * inotify_rm_watch - remove a watch from an inotify instance

 * @ih: inotify handle

 * @watch: watch to remove

 *

 * Can sleep.

 */

int inotify_rm_watch(struct inotify_handle *ih,

		     struct inotify_watch *watch)

{

	return inotify_rm_wd(ih, watch->wd);

}

EXPORT_SYMBOL_GPL(inotify_rm_watch);



/*

 * inotify_setup - core initialization function

 */

fs/inotify_user.c

+1 −0
Original line number Diff line number Diff line
@@ -380,6 +380,7 @@ static int create_watch(struct inotify_device *dev, struct inode *inode, 


	atomic_inc(&dev->user->inotify_watches);



	inotify_init_watch(&watch->wdata);

	ret = inotify_add_watch(dev->ih, &watch->wdata, inode, mask);

	if (ret < 0)

		free_inotify_user_watch(&watch->wdata);

include/linux/inotify.h

+20 −0
Original line number Diff line number Diff line
@@ -112,11 +112,15 @@ extern u32 inotify_get_cookie(void); 
/* Kernel Consumer API */



extern struct inotify_handle *inotify_init(const struct inotify_operations *);

extern void inotify_init_watch(struct inotify_watch *);

extern void inotify_destroy(struct inotify_handle *);

extern __s32 inotify_find_watch(struct inotify_handle *, struct inode *,

				struct inotify_watch **);

extern __s32 inotify_find_update_watch(struct inotify_handle *, struct inode *,

				       u32);

extern __s32 inotify_add_watch(struct inotify_handle *, struct inotify_watch *,

			       struct inode *, __u32);

extern int inotify_rm_watch(struct inotify_handle *, struct inotify_watch *);

extern int inotify_rm_wd(struct inotify_handle *, __u32);

extern void get_inotify_watch(struct inotify_watch *);

extern void put_inotify_watch(struct inotify_watch *);
@@ -163,10 +167,20 @@ static inline struct inotify_handle *inotify_init(const struct inotify_operation 
	return ERR_PTR(-EOPNOTSUPP);

}



static inline void inotify_init_watch(struct inotify_watch *watch)

{

}



static inline void inotify_destroy(struct inotify_handle *ih)

{

}



static inline __s32 inotify_find_watch(struct inotify_handle *ih, struct inode *inode,

				       struct inotify_watch **watchp)

{

	return -EOPNOTSUPP;

}



static inline __s32 inotify_find_update_watch(struct inotify_handle *ih,

					      struct inode *inode, u32 mask)

{
@@ -180,6 +194,12 @@ static inline __s32 inotify_add_watch(struct inotify_handle *ih, 
	return -EOPNOTSUPP;

}



static inline int inotify_rm_watch(struct inotify_handle *ih,

				   struct inotify_watch *watch)

{

	return -EOPNOTSUPP;

}



static inline int inotify_rm_wd(struct inotify_handle *ih, __u32 wd)

{

	return -EOPNOTSUPP;

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