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

[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
......@@ -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
*/
......
......@@ -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);
......
......@@ -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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