#include <linux/idr.h>
#include <linux/slab.h>
#include <linux/fs.h>
+#include <linux/sched.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/writeback.h>
struct dentry *child;
list_for_each_entry(child, &alias->d_subdirs, d_u.d_child) {
- if (!child->d_inode) {
- WARN_ON(child->d_flags & DCACHE_INOTIFY_PARENT_WATCHED);
+ if (!child->d_inode)
continue;
- }
+
spin_lock(&child->d_lock);
- if (watched) {
- WARN_ON(child->d_flags &
- DCACHE_INOTIFY_PARENT_WATCHED);
+ if (watched)
child->d_flags |= DCACHE_INOTIFY_PARENT_WATCHED;
- } else {
- WARN_ON(!(child->d_flags &
- DCACHE_INOTIFY_PARENT_WATCHED));
- child->d_flags&=~DCACHE_INOTIFY_PARENT_WATCHED;
- }
+ else
+ child->d_flags &=~DCACHE_INOTIFY_PARENT_WATCHED;
spin_unlock(&child->d_lock);
}
}
}
/*
- * remove_watch_no_event - remove_watch() without the IN_IGNORED event.
+ * remove_watch_no_event - remove watch without the IN_IGNORED event.
*
* Callers must hold both inode->inotify_mutex and ih->mutex.
*/
idr_remove(&ih->idr, watch->wd);
}
-/*
- * remove_watch - Remove a watch from both the handle and the inode. Sends
- * the IN_IGNORED event signifying that the inode is no longer watched.
+/**
+ * inotify_remove_watch_locked - Remove a watch from both the handle and the
+ * inode. Sends the IN_IGNORED event signifying that the inode is no longer
+ * watched. May be invoked from a caller's event handler.
+ * @ih: inotify handle associated with watch
+ * @watch: watch to remove
*
* Callers must hold both inode->inotify_mutex and ih->mutex.
*/
-static void remove_watch(struct inotify_watch *watch, struct inotify_handle *ih)
+void inotify_remove_watch_locked(struct inotify_handle *ih,
+ struct inotify_watch *watch)
{
remove_watch_no_event(watch, ih);
ih->in_ops->handle_event(watch, watch->wd, IN_IGNORED, 0, NULL, NULL);
}
+EXPORT_SYMBOL_GPL(inotify_remove_watch_locked);
/* Kernel API for producing events */
if (!inode)
return;
- WARN_ON(entry->d_flags & DCACHE_INOTIFY_PARENT_WATCHED);
spin_lock(&entry->d_lock);
parent = entry->d_parent;
if (parent->d_inode && inotify_inode_watched(parent->d_inode))
need_iput_tmp = need_iput;
need_iput = NULL;
- /* In case the remove_watch() drops a reference. */
+ /* In case inotify_remove_watch_locked() drops a reference. */
if (inode != need_iput_tmp)
__iget(inode);
else
mutex_lock(&ih->mutex);
ih->in_ops->handle_event(watch, watch->wd, IN_UNMOUNT, 0,
NULL, NULL);
- remove_watch(watch, ih);
+ inotify_remove_watch_locked(ih, watch);
mutex_unlock(&ih->mutex);
}
mutex_unlock(&inode->inotify_mutex);
list_for_each_entry_safe(watch, next, &inode->inotify_watches, i_list) {
struct inotify_handle *ih = watch->ih;
mutex_lock(&ih->mutex);
- remove_watch(watch, ih);
+ inotify_remove_watch_locked(ih, watch);
mutex_unlock(&ih->mutex);
}
mutex_unlock(&inode->inotify_mutex);
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
*/
mutex_unlock(&ih->mutex);
break;
}
- watch = list_entry(watches->next, struct inotify_watch, h_list);
+ watch = list_first_entry(watches, struct inotify_watch, h_list);
get_inotify_watch(watch);
mutex_unlock(&ih->mutex);
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
* @inode: inode's watch to update
struct inode *inode, u32 mask)
{
int ret = 0;
+ int newly_watched;
/* don't allow invalid bits: we don't want flags set */
mask &= IN_ALL_EVENTS | IN_ONESHOT;
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;
*/
watch->inode = igrab(inode);
- get_inotify_watch(watch); /* initial get */
-
- if (!inotify_inode_watched(inode))
- set_dentry_child_flags(inode, 1);
-
/* Add the watch to the handle's and the inode's list */
+ newly_watched = !inotify_inode_watched(inode);
list_add(&watch->h_list, &ih->watches);
list_add(&watch->i_list, &inode->inotify_watches);
+ /*
+ * Set child flags _after_ adding the watch, so there is no race
+ * windows where newly instantiated children could miss their parent's
+ * watched flag.
+ */
+ if (newly_watched)
+ set_dentry_child_flags(inode, 1);
+
out:
mutex_unlock(&ih->mutex);
mutex_unlock(&inode->inotify_mutex);
EXPORT_SYMBOL_GPL(inotify_add_watch);
/**
+ * inotify_clone_watch - put the watch next to existing one
+ * @old: already installed watch
+ * @new: new watch
+ *
+ * Caller must hold the inotify_mutex of inode we are dealing with;
+ * it is expected to remove the old watch before unlocking the inode.
+ */
+s32 inotify_clone_watch(struct inotify_watch *old, struct inotify_watch *new)
+{
+ struct inotify_handle *ih = old->ih;
+ int ret = 0;
+
+ new->mask = old->mask;
+ new->ih = ih;
+
+ mutex_lock(&ih->mutex);
+
+ /* Initialize a new watch */
+ ret = inotify_handle_get_wd(ih, new);
+ if (unlikely(ret))
+ goto out;
+ ret = new->wd;
+
+ get_inotify_handle(ih);
+
+ new->inode = igrab(old->inode);
+
+ list_add(&new->h_list, &ih->watches);
+ list_add(&new->i_list, &old->inode->inotify_watches);
+out:
+ mutex_unlock(&ih->mutex);
+ return ret;
+}
+
+void inotify_evict_watch(struct inotify_watch *watch)
+{
+ get_inotify_watch(watch);
+ mutex_lock(&watch->ih->mutex);
+ inotify_remove_watch_locked(watch->ih, watch);
+ mutex_unlock(&watch->ih->mutex);
+}
+
+/**
* inotify_rm_wd - remove a watch from an inotify instance
* @ih: inotify handle
* @wd: watch descriptor to remove
/* make sure that we did not race */
if (likely(idr_find(&ih->idr, wd) == watch))
- remove_watch(watch, ih);
+ inotify_remove_watch_locked(ih, watch);
mutex_unlock(&ih->mutex);
mutex_unlock(&inode->inotify_mutex);
}
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
*/
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff