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-rw-r--r--fs/notify/inode_mark.c247
1 files changed, 247 insertions, 0 deletions
diff --git a/fs/notify/inode_mark.c b/fs/notify/inode_mark.c
new file mode 100644
index 000000000..3daf513ee
--- /dev/null
+++ b/fs/notify/inode_mark.c
@@ -0,0 +1,247 @@
+/*
+ * Copyright (C) 2008 Red Hat, Inc., Eric Paris <eparis@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING. If not, write to
+ * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/spinlock.h>
+
+#include <linux/atomic.h>
+
+#include <linux/fsnotify_backend.h>
+#include "fsnotify.h"
+
+#include "../internal.h"
+
+/*
+ * Recalculate the inode->i_fsnotify_mask, or the mask of all FS_* event types
+ * any notifier is interested in hearing for this inode.
+ */
+void fsnotify_recalc_inode_mask(struct inode *inode)
+{
+ spin_lock(&inode->i_lock);
+ inode->i_fsnotify_mask = fsnotify_recalc_mask(&inode->i_fsnotify_marks);
+ spin_unlock(&inode->i_lock);
+
+ __fsnotify_update_child_dentry_flags(inode);
+}
+
+void fsnotify_destroy_inode_mark(struct fsnotify_mark *mark)
+{
+ struct inode *inode = mark->inode;
+
+ BUG_ON(!mutex_is_locked(&mark->group->mark_mutex));
+ assert_spin_locked(&mark->lock);
+
+ spin_lock(&inode->i_lock);
+
+ hlist_del_init_rcu(&mark->obj_list);
+ mark->inode = NULL;
+
+ /*
+ * this mark is now off the inode->i_fsnotify_marks list and we
+ * hold the inode->i_lock, so this is the perfect time to update the
+ * inode->i_fsnotify_mask
+ */
+ inode->i_fsnotify_mask = fsnotify_recalc_mask(&inode->i_fsnotify_marks);
+ spin_unlock(&inode->i_lock);
+}
+
+/*
+ * Given an inode, destroy all of the marks associated with that inode.
+ */
+void fsnotify_clear_marks_by_inode(struct inode *inode)
+{
+ struct fsnotify_mark *mark;
+ struct hlist_node *n;
+ LIST_HEAD(free_list);
+
+ spin_lock(&inode->i_lock);
+ hlist_for_each_entry_safe(mark, n, &inode->i_fsnotify_marks, obj_list) {
+ list_add(&mark->free_list, &free_list);
+ hlist_del_init_rcu(&mark->obj_list);
+ fsnotify_get_mark(mark);
+ }
+ spin_unlock(&inode->i_lock);
+
+ fsnotify_destroy_marks(&free_list);
+}
+
+/*
+ * Given a group clear all of the inode marks associated with that group.
+ */
+void fsnotify_clear_inode_marks_by_group(struct fsnotify_group *group)
+{
+ fsnotify_clear_marks_by_group_flags(group, FSNOTIFY_MARK_FLAG_INODE);
+}
+
+/*
+ * given a group and inode, find the mark associated with that combination.
+ * if found take a reference to that mark and return it, else return NULL
+ */
+struct fsnotify_mark *fsnotify_find_inode_mark(struct fsnotify_group *group,
+ struct inode *inode)
+{
+ struct fsnotify_mark *mark;
+
+ spin_lock(&inode->i_lock);
+ mark = fsnotify_find_mark(&inode->i_fsnotify_marks, group);
+ spin_unlock(&inode->i_lock);
+
+ return mark;
+}
+
+/*
+ * If we are setting a mark mask on an inode mark we should pin the inode
+ * in memory.
+ */
+void fsnotify_set_inode_mark_mask_locked(struct fsnotify_mark *mark,
+ __u32 mask)
+{
+ struct inode *inode;
+
+ assert_spin_locked(&mark->lock);
+
+ if (mask &&
+ mark->inode &&
+ !(mark->flags & FSNOTIFY_MARK_FLAG_OBJECT_PINNED)) {
+ mark->flags |= FSNOTIFY_MARK_FLAG_OBJECT_PINNED;
+ inode = igrab(mark->inode);
+ /*
+ * we shouldn't be able to get here if the inode wasn't
+ * already safely held in memory. But bug in case it
+ * ever is wrong.
+ */
+ BUG_ON(!inode);
+ }
+}
+
+/*
+ * Attach an initialized mark to a given inode.
+ * These marks may be used for the fsnotify backend to determine which
+ * event types should be delivered to which group and for which inodes. These
+ * marks are ordered according to priority, highest number first, and then by
+ * the group's location in memory.
+ */
+int fsnotify_add_inode_mark(struct fsnotify_mark *mark,
+ struct fsnotify_group *group, struct inode *inode,
+ int allow_dups)
+{
+ int ret;
+
+ mark->flags |= FSNOTIFY_MARK_FLAG_INODE;
+
+ BUG_ON(!mutex_is_locked(&group->mark_mutex));
+ assert_spin_locked(&mark->lock);
+
+ spin_lock(&inode->i_lock);
+ mark->inode = inode;
+ ret = fsnotify_add_mark_list(&inode->i_fsnotify_marks, mark,
+ allow_dups);
+ inode->i_fsnotify_mask = fsnotify_recalc_mask(&inode->i_fsnotify_marks);
+ spin_unlock(&inode->i_lock);
+
+ return ret;
+}
+
+/**
+ * fsnotify_unmount_inodes - an sb is unmounting. handle any watched inodes.
+ * @list: list of inodes being unmounted (sb->s_inodes)
+ *
+ * Called during unmount with no locks held, so needs to be safe against
+ * concurrent modifiers. We temporarily drop inode_sb_list_lock and CAN block.
+ */
+void fsnotify_unmount_inodes(struct list_head *list)
+{
+ struct inode *inode, *next_i, *need_iput = NULL;
+
+ spin_lock(&inode_sb_list_lock);
+ list_for_each_entry_safe(inode, next_i, list, i_sb_list) {
+ struct inode *need_iput_tmp;
+
+ /*
+ * We cannot __iget() an inode in state I_FREEING,
+ * I_WILL_FREE, or I_NEW which is fine because by that point
+ * the inode cannot have any associated watches.
+ */
+ spin_lock(&inode->i_lock);
+ if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) {
+ spin_unlock(&inode->i_lock);
+ continue;
+ }
+
+ /*
+ * If i_count is zero, the inode cannot have any watches and
+ * doing an __iget/iput with MS_ACTIVE clear would actually
+ * evict all inodes with zero i_count from icache which is
+ * unnecessarily violent and may in fact be illegal to do.
+ */
+ if (!atomic_read(&inode->i_count)) {
+ spin_unlock(&inode->i_lock);
+ continue;
+ }
+
+ need_iput_tmp = need_iput;
+ need_iput = NULL;
+
+ /* In case fsnotify_inode_delete() drops a reference. */
+ if (inode != need_iput_tmp)
+ __iget(inode);
+ else
+ need_iput_tmp = NULL;
+ spin_unlock(&inode->i_lock);
+
+ /* In case the dropping of a reference would nuke next_i. */
+ while (&next_i->i_sb_list != list) {
+ spin_lock(&next_i->i_lock);
+ if (!(next_i->i_state & (I_FREEING | I_WILL_FREE)) &&
+ atomic_read(&next_i->i_count)) {
+ __iget(next_i);
+ need_iput = next_i;
+ spin_unlock(&next_i->i_lock);
+ break;
+ }
+ spin_unlock(&next_i->i_lock);
+ next_i = list_entry(next_i->i_sb_list.next,
+ struct inode, i_sb_list);
+ }
+
+ /*
+ * We can safely drop inode_sb_list_lock here because either
+ * we actually hold references on both inode and next_i or
+ * end of list. Also no new inodes will be added since the
+ * umount has begun.
+ */
+ spin_unlock(&inode_sb_list_lock);
+
+ if (need_iput_tmp)
+ iput(need_iput_tmp);
+
+ /* for each watch, send FS_UNMOUNT and then remove it */
+ fsnotify(inode, FS_UNMOUNT, inode, FSNOTIFY_EVENT_INODE, NULL, 0);
+
+ fsnotify_inode_delete(inode);
+
+ iput(inode);
+
+ spin_lock(&inode_sb_list_lock);
+ }
+ spin_unlock(&inode_sb_list_lock);
+}