[Feature] add GA346 baseline version
Change-Id: Ic62933698569507dcf98240cdf5d9931ae34348f
diff --git a/src/kernel/linux/v4.19/fs/notify/fsnotify.c b/src/kernel/linux/v4.19/fs/notify/fsnotify.c
new file mode 100644
index 0000000..e8ee426
--- /dev/null
+++ b/src/kernel/linux/v4.19/fs/notify/fsnotify.c
@@ -0,0 +1,407 @@
+/*
+ * 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/dcache.h>
+#include <linux/fs.h>
+#include <linux/gfp.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/mount.h>
+#include <linux/srcu.h>
+
+#include <linux/fsnotify_backend.h>
+#include "fsnotify.h"
+
+/*
+ * Clear all of the marks on an inode when it is being evicted from core
+ */
+void __fsnotify_inode_delete(struct inode *inode)
+{
+ fsnotify_clear_marks_by_inode(inode);
+}
+EXPORT_SYMBOL_GPL(__fsnotify_inode_delete);
+
+void __fsnotify_vfsmount_delete(struct vfsmount *mnt)
+{
+ fsnotify_clear_marks_by_mount(mnt);
+}
+
+/**
+ * fsnotify_unmount_inodes - an sb is unmounting. handle any watched inodes.
+ * @sb: superblock being unmounted.
+ *
+ * Called during unmount with no locks held, so needs to be safe against
+ * concurrent modifiers. We temporarily drop sb->s_inode_list_lock and CAN block.
+ */
+void fsnotify_unmount_inodes(struct super_block *sb)
+{
+ struct inode *inode, *iput_inode = NULL;
+
+ spin_lock(&sb->s_inode_list_lock);
+ list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
+ /*
+ * 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 SB_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;
+ }
+
+ __iget(inode);
+ spin_unlock(&inode->i_lock);
+ spin_unlock(&sb->s_inode_list_lock);
+
+ if (iput_inode)
+ iput(iput_inode);
+
+ /* 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 = inode;
+
+ cond_resched();
+ spin_lock(&sb->s_inode_list_lock);
+ }
+ spin_unlock(&sb->s_inode_list_lock);
+
+ if (iput_inode)
+ iput(iput_inode);
+ /* Wait for outstanding inode references from connectors */
+ wait_var_event(&sb->s_fsnotify_inode_refs,
+ !atomic_long_read(&sb->s_fsnotify_inode_refs));
+}
+
+/*
+ * Given an inode, first check if we care what happens to our children. Inotify
+ * and dnotify both tell their parents about events. If we care about any event
+ * on a child we run all of our children and set a dentry flag saying that the
+ * parent cares. Thus when an event happens on a child it can quickly tell if
+ * if there is a need to find a parent and send the event to the parent.
+ */
+void __fsnotify_update_child_dentry_flags(struct inode *inode)
+{
+ struct dentry *alias;
+ int watched;
+
+ if (!S_ISDIR(inode->i_mode))
+ return;
+
+ /* determine if the children should tell inode about their events */
+ watched = fsnotify_inode_watches_children(inode);
+
+ spin_lock(&inode->i_lock);
+ /* run all of the dentries associated with this inode. Since this is a
+ * directory, there damn well better only be one item on this list */
+ hlist_for_each_entry(alias, &inode->i_dentry, d_u.d_alias) {
+ struct dentry *child;
+
+ /* run all of the children of the original inode and fix their
+ * d_flags to indicate parental interest (their parent is the
+ * original inode) */
+ spin_lock(&alias->d_lock);
+ list_for_each_entry(child, &alias->d_subdirs, d_child) {
+ if (!child->d_inode)
+ continue;
+
+ spin_lock_nested(&child->d_lock, DENTRY_D_LOCK_NESTED);
+ if (watched)
+ child->d_flags |= DCACHE_FSNOTIFY_PARENT_WATCHED;
+ else
+ child->d_flags &= ~DCACHE_FSNOTIFY_PARENT_WATCHED;
+ spin_unlock(&child->d_lock);
+ }
+ spin_unlock(&alias->d_lock);
+ }
+ spin_unlock(&inode->i_lock);
+}
+
+/* Notify this dentry's parent about a child's events. */
+int __fsnotify_parent(const struct path *path, struct dentry *dentry, __u32 mask)
+{
+ struct dentry *parent;
+ struct inode *p_inode;
+ int ret = 0;
+
+ if (!dentry)
+ dentry = path->dentry;
+
+ if (!(dentry->d_flags & DCACHE_FSNOTIFY_PARENT_WATCHED))
+ return 0;
+
+ parent = dget_parent(dentry);
+ p_inode = parent->d_inode;
+
+ if (unlikely(!fsnotify_inode_watches_children(p_inode))) {
+ __fsnotify_update_child_dentry_flags(p_inode);
+ } else if (p_inode->i_fsnotify_mask & mask & ALL_FSNOTIFY_EVENTS) {
+ struct name_snapshot name;
+
+ /* we are notifying a parent so come up with the new mask which
+ * specifies these are events which came from a child. */
+ mask |= FS_EVENT_ON_CHILD;
+
+ take_dentry_name_snapshot(&name, dentry);
+ if (path)
+ ret = fsnotify(p_inode, mask, path, FSNOTIFY_EVENT_PATH,
+ name.name, 0);
+ else
+ ret = fsnotify(p_inode, mask, dentry->d_inode, FSNOTIFY_EVENT_INODE,
+ name.name, 0);
+ release_dentry_name_snapshot(&name);
+ }
+
+ dput(parent);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(__fsnotify_parent);
+
+static int send_to_group(struct inode *to_tell,
+ __u32 mask, const void *data,
+ int data_is, u32 cookie,
+ const unsigned char *file_name,
+ struct fsnotify_iter_info *iter_info)
+{
+ struct fsnotify_group *group = NULL;
+ __u32 test_mask = (mask & ALL_FSNOTIFY_EVENTS);
+ __u32 marks_mask = 0;
+ __u32 marks_ignored_mask = 0;
+ struct fsnotify_mark *mark;
+ int type;
+
+ if (WARN_ON(!iter_info->report_mask))
+ return 0;
+
+ /* clear ignored on inode modification */
+ if (mask & FS_MODIFY) {
+ fsnotify_foreach_obj_type(type) {
+ if (!fsnotify_iter_should_report_type(iter_info, type))
+ continue;
+ mark = iter_info->marks[type];
+ if (mark &&
+ !(mark->flags & FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY))
+ mark->ignored_mask = 0;
+ }
+ }
+
+ fsnotify_foreach_obj_type(type) {
+ if (!fsnotify_iter_should_report_type(iter_info, type))
+ continue;
+ mark = iter_info->marks[type];
+ /* does the object mark tell us to do something? */
+ if (mark) {
+ group = mark->group;
+ marks_mask |= mark->mask;
+ marks_ignored_mask |= mark->ignored_mask;
+ }
+ }
+
+ pr_debug("%s: group=%p to_tell=%p mask=%x marks_mask=%x marks_ignored_mask=%x"
+ " data=%p data_is=%d cookie=%d\n",
+ __func__, group, to_tell, mask, marks_mask, marks_ignored_mask,
+ data, data_is, cookie);
+
+ if (!(test_mask & marks_mask & ~marks_ignored_mask))
+ return 0;
+
+ return group->ops->handle_event(group, to_tell, mask, data, data_is,
+ file_name, cookie, iter_info);
+}
+
+static struct fsnotify_mark *fsnotify_first_mark(struct fsnotify_mark_connector **connp)
+{
+ struct fsnotify_mark_connector *conn;
+ struct hlist_node *node = NULL;
+
+ conn = srcu_dereference(*connp, &fsnotify_mark_srcu);
+ if (conn)
+ node = srcu_dereference(conn->list.first, &fsnotify_mark_srcu);
+
+ return hlist_entry_safe(node, struct fsnotify_mark, obj_list);
+}
+
+static struct fsnotify_mark *fsnotify_next_mark(struct fsnotify_mark *mark)
+{
+ struct hlist_node *node = NULL;
+
+ if (mark)
+ node = srcu_dereference(mark->obj_list.next,
+ &fsnotify_mark_srcu);
+
+ return hlist_entry_safe(node, struct fsnotify_mark, obj_list);
+}
+
+/*
+ * iter_info is a multi head priority queue of marks.
+ * Pick a subset of marks from queue heads, all with the
+ * same group and set the report_mask for selected subset.
+ * Returns the report_mask of the selected subset.
+ */
+static unsigned int fsnotify_iter_select_report_types(
+ struct fsnotify_iter_info *iter_info)
+{
+ struct fsnotify_group *max_prio_group = NULL;
+ struct fsnotify_mark *mark;
+ int type;
+
+ /* Choose max prio group among groups of all queue heads */
+ fsnotify_foreach_obj_type(type) {
+ mark = iter_info->marks[type];
+ if (mark &&
+ fsnotify_compare_groups(max_prio_group, mark->group) > 0)
+ max_prio_group = mark->group;
+ }
+
+ if (!max_prio_group)
+ return 0;
+
+ /* Set the report mask for marks from same group as max prio group */
+ iter_info->report_mask = 0;
+ fsnotify_foreach_obj_type(type) {
+ mark = iter_info->marks[type];
+ if (mark &&
+ fsnotify_compare_groups(max_prio_group, mark->group) == 0)
+ fsnotify_iter_set_report_type(iter_info, type);
+ }
+
+ return iter_info->report_mask;
+}
+
+/*
+ * Pop from iter_info multi head queue, the marks that were iterated in the
+ * current iteration step.
+ */
+static void fsnotify_iter_next(struct fsnotify_iter_info *iter_info)
+{
+ int type;
+
+ fsnotify_foreach_obj_type(type) {
+ if (fsnotify_iter_should_report_type(iter_info, type))
+ iter_info->marks[type] =
+ fsnotify_next_mark(iter_info->marks[type]);
+ }
+}
+
+/*
+ * This is the main call to fsnotify. The VFS calls into hook specific functions
+ * in linux/fsnotify.h. Those functions then in turn call here. Here will call
+ * out to all of the registered fsnotify_group. Those groups can then use the
+ * notification event in whatever means they feel necessary.
+ */
+int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_is,
+ const unsigned char *file_name, u32 cookie)
+{
+ struct fsnotify_iter_info iter_info = {};
+ struct mount *mnt;
+ int ret = 0;
+ __u32 test_mask = (mask & ALL_FSNOTIFY_EVENTS);
+
+ if (data_is == FSNOTIFY_EVENT_PATH)
+ mnt = real_mount(((const struct path *)data)->mnt);
+ else
+ mnt = NULL;
+
+ /* An event "on child" is not intended for a mount mark */
+ if (mask & FS_EVENT_ON_CHILD)
+ mnt = NULL;
+
+ /*
+ * Optimization: srcu_read_lock() has a memory barrier which can
+ * be expensive. It protects walking the *_fsnotify_marks lists.
+ * However, if we do not walk the lists, we do not have to do
+ * SRCU because we have no references to any objects and do not
+ * need SRCU to keep them "alive".
+ */
+ if (!to_tell->i_fsnotify_marks &&
+ (!mnt || !mnt->mnt_fsnotify_marks))
+ return 0;
+ /*
+ * if this is a modify event we may need to clear the ignored masks
+ * otherwise return if neither the inode nor the vfsmount care about
+ * this type of event.
+ */
+ if (!(mask & FS_MODIFY) &&
+ !(test_mask & to_tell->i_fsnotify_mask) &&
+ !(mnt && test_mask & mnt->mnt_fsnotify_mask))
+ return 0;
+
+ iter_info.srcu_idx = srcu_read_lock(&fsnotify_mark_srcu);
+
+ iter_info.marks[FSNOTIFY_OBJ_TYPE_INODE] =
+ fsnotify_first_mark(&to_tell->i_fsnotify_marks);
+ if (mnt) {
+ iter_info.marks[FSNOTIFY_OBJ_TYPE_VFSMOUNT] =
+ fsnotify_first_mark(&mnt->mnt_fsnotify_marks);
+ }
+
+ /*
+ * We need to merge inode & vfsmount mark lists so that inode mark
+ * ignore masks are properly reflected for mount mark notifications.
+ * That's why this traversal is so complicated...
+ */
+ while (fsnotify_iter_select_report_types(&iter_info)) {
+ ret = send_to_group(to_tell, mask, data, data_is, cookie,
+ file_name, &iter_info);
+
+ if (ret && (mask & ALL_FSNOTIFY_PERM_EVENTS))
+ goto out;
+
+ fsnotify_iter_next(&iter_info);
+ }
+ ret = 0;
+out:
+ srcu_read_unlock(&fsnotify_mark_srcu, iter_info.srcu_idx);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(fsnotify);
+
+extern struct kmem_cache *fsnotify_mark_connector_cachep;
+
+static __init int fsnotify_init(void)
+{
+ int ret;
+
+ BUG_ON(hweight32(ALL_FSNOTIFY_BITS) != 23);
+
+ ret = init_srcu_struct(&fsnotify_mark_srcu);
+ if (ret)
+ panic("initializing fsnotify_mark_srcu");
+
+ fsnotify_mark_connector_cachep = KMEM_CACHE(fsnotify_mark_connector,
+ SLAB_PANIC);
+
+ return 0;
+}
+core_initcall(fsnotify_init);