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-rw-r--r--fs/notify/fsnotify.c201
1 files changed, 166 insertions, 35 deletions
diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c
index fcc2f06..4d2a82c 100644
--- a/fs/notify/fsnotify.c
+++ b/fs/notify/fsnotify.c
@@ -21,6 +21,7 @@
#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>
@@ -35,6 +36,11 @@ void __fsnotify_inode_delete(struct inode *inode)
}
EXPORT_SYMBOL_GPL(__fsnotify_inode_delete);
+void __fsnotify_vfsmount_delete(struct vfsmount *mnt)
+{
+ fsnotify_clear_marks_by_mount(mnt);
+}
+
/*
* 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
@@ -78,13 +84,16 @@ void __fsnotify_update_child_dentry_flags(struct inode *inode)
}
/* Notify this dentry's parent about a child's events. */
-void __fsnotify_parent(struct dentry *dentry, __u32 mask)
+void __fsnotify_parent(struct file *file, struct dentry *dentry, __u32 mask)
{
struct dentry *parent;
struct inode *p_inode;
bool send = false;
bool should_update_children = false;
+ if (!dentry)
+ dentry = file->f_path.dentry;
+
if (!(dentry->d_flags & DCACHE_FSNOTIFY_PARENT_WATCHED))
return;
@@ -115,8 +124,12 @@ void __fsnotify_parent(struct dentry *dentry, __u32 mask)
* specifies these are events which came from a child. */
mask |= FS_EVENT_ON_CHILD;
- fsnotify(p_inode, mask, dentry->d_inode, FSNOTIFY_EVENT_INODE,
- dentry->d_name.name, 0);
+ if (file)
+ fsnotify(p_inode, mask, file, FSNOTIFY_EVENT_FILE,
+ dentry->d_name.name, 0);
+ else
+ fsnotify(p_inode, mask, dentry->d_inode, FSNOTIFY_EVENT_INODE,
+ dentry->d_name.name, 0);
dput(parent);
}
@@ -127,63 +140,181 @@ void __fsnotify_parent(struct dentry *dentry, __u32 mask)
}
EXPORT_SYMBOL_GPL(__fsnotify_parent);
+static int send_to_group(struct inode *to_tell, struct vfsmount *mnt,
+ struct fsnotify_mark *inode_mark,
+ struct fsnotify_mark *vfsmount_mark,
+ __u32 mask, void *data,
+ int data_is, u32 cookie,
+ const unsigned char *file_name,
+ struct fsnotify_event **event)
+{
+ struct fsnotify_group *group = inode_mark->group;
+ __u32 inode_test_mask = (mask & ~FS_EVENT_ON_CHILD);
+ __u32 vfsmount_test_mask = (mask & ~FS_EVENT_ON_CHILD);
+
+ pr_debug("%s: group=%p to_tell=%p mnt=%p mark=%p mask=%x data=%p"
+ " data_is=%d cookie=%d event=%p\n", __func__, group, to_tell,
+ mnt, inode_mark, mask, data, data_is, cookie, *event);
+
+ /* clear ignored on inode modification */
+ if (mask & FS_MODIFY) {
+ if (inode_mark &&
+ !(inode_mark->flags & FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY))
+ inode_mark->ignored_mask = 0;
+ if (vfsmount_mark &&
+ !(vfsmount_mark->flags & FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY))
+ vfsmount_mark->ignored_mask = 0;
+ }
+
+ /* does the inode mark tell us to do something? */
+ if (inode_mark) {
+ inode_test_mask &= inode_mark->mask;
+ inode_test_mask &= ~inode_mark->ignored_mask;
+ }
+
+ /* does the vfsmount_mark tell us to do something? */
+ if (vfsmount_mark) {
+ vfsmount_test_mask &= vfsmount_mark->mask;
+ vfsmount_test_mask &= ~vfsmount_mark->ignored_mask;
+ if (inode_mark)
+ vfsmount_test_mask &= ~inode_mark->ignored_mask;
+ }
+
+ if (!inode_test_mask && !vfsmount_test_mask)
+ return 0;
+
+ if (group->ops->should_send_event(group, to_tell, inode_mark,
+ vfsmount_mark, mask, data,
+ data_is) == false)
+ return 0;
+
+ if (!*event) {
+ *event = fsnotify_create_event(to_tell, mask, data,
+ data_is, file_name,
+ cookie, GFP_KERNEL);
+ if (!*event)
+ return -ENOMEM;
+ }
+ return group->ops->handle_event(group, inode_mark, vfsmount_mark, *event);
+}
+
/*
* 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.
*/
-void fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is, const char *file_name, u32 cookie)
+int fsnotify(struct inode *to_tell, __u32 mask, void *data, int data_is,
+ const unsigned char *file_name, u32 cookie)
{
- struct fsnotify_group *group;
+ struct hlist_node *inode_node, *vfsmount_node;
+ struct fsnotify_mark *inode_mark = NULL, *vfsmount_mark = NULL;
+ struct fsnotify_group *inode_group, *vfsmount_group;
struct fsnotify_event *event = NULL;
- int idx;
+ struct vfsmount *mnt;
+ int idx, ret = 0;
+ bool used_inode = false, used_vfsmount = false;
/* global tests shouldn't care about events on child only the specific event */
__u32 test_mask = (mask & ~FS_EVENT_ON_CHILD);
- if (list_empty(&fsnotify_groups))
- return;
+ if (data_is == FSNOTIFY_EVENT_FILE)
+ mnt = ((struct file *)data)->f_path.mnt;
+ else
+ mnt = NULL;
- if (!(test_mask & fsnotify_mask))
- return;
-
- if (!(test_mask & to_tell->i_fsnotify_mask))
- return;
/*
- * SRCU!! the groups list is very very much read only and the path is
- * very hot. The VAST majority of events are not going to need to do
- * anything other than walk the list so it's crazy to pre-allocate.
+ * 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.
*/
- idx = srcu_read_lock(&fsnotify_grp_srcu);
- list_for_each_entry_rcu(group, &fsnotify_groups, group_list) {
- if (test_mask & group->mask) {
- if (!group->ops->should_send_event(group, to_tell, mask))
- continue;
- if (!event) {
- event = fsnotify_create_event(to_tell, mask, data,
- data_is, file_name, cookie,
- GFP_KERNEL);
- /* shit, we OOM'd and now we can't tell, maybe
- * someday someone else will want to do something
- * here */
- if (!event)
- break;
- }
- group->ops->handle_event(group, event);
+ if (!(mask & FS_MODIFY) &&
+ !(test_mask & to_tell->i_fsnotify_mask) &&
+ !(mnt && test_mask & mnt->mnt_fsnotify_mask))
+ return 0;
+
+ idx = srcu_read_lock(&fsnotify_mark_srcu);
+
+ if ((mask & FS_MODIFY) ||
+ (test_mask & to_tell->i_fsnotify_mask))
+ inode_node = srcu_dereference(to_tell->i_fsnotify_marks.first,
+ &fsnotify_mark_srcu);
+ else
+ inode_node = NULL;
+
+ if (mnt) {
+ if ((mask & FS_MODIFY) ||
+ (test_mask & mnt->mnt_fsnotify_mask))
+ vfsmount_node = srcu_dereference(mnt->mnt_fsnotify_marks.first,
+ &fsnotify_mark_srcu);
+ else
+ vfsmount_node = NULL;
+ } else {
+ mnt = NULL;
+ vfsmount_node = NULL;
+ }
+
+ while (inode_node || vfsmount_node) {
+ if (inode_node) {
+ inode_mark = hlist_entry(srcu_dereference(inode_node, &fsnotify_mark_srcu),
+ struct fsnotify_mark, i.i_list);
+ inode_group = inode_mark->group;
+ } else
+ inode_group = (void *)-1;
+
+ if (vfsmount_node) {
+ vfsmount_mark = hlist_entry(srcu_dereference(vfsmount_node, &fsnotify_mark_srcu),
+ struct fsnotify_mark, m.m_list);
+ vfsmount_group = vfsmount_mark->group;
+ } else
+ vfsmount_group = (void *)-1;
+
+ if (inode_group < vfsmount_group) {
+ /* handle inode */
+ send_to_group(to_tell, NULL, inode_mark, NULL, mask, data,
+ data_is, cookie, file_name, &event);
+ used_inode = true;
+ } else if (vfsmount_group < inode_group) {
+ send_to_group(to_tell, mnt, NULL, vfsmount_mark, mask, data,
+ data_is, cookie, file_name, &event);
+ used_vfsmount = true;
+ } else {
+ send_to_group(to_tell, mnt, inode_mark, vfsmount_mark,
+ mask, data, data_is, cookie, file_name,
+ &event);
+ used_vfsmount = true;
+ used_inode = true;
}
+
+ if (used_inode)
+ inode_node = srcu_dereference(inode_node->next,
+ &fsnotify_mark_srcu);
+ if (used_vfsmount)
+ vfsmount_node = srcu_dereference(vfsmount_node->next,
+ &fsnotify_mark_srcu);
}
- srcu_read_unlock(&fsnotify_grp_srcu, idx);
+
+ srcu_read_unlock(&fsnotify_mark_srcu, idx);
/*
* fsnotify_create_event() took a reference so the event can't be cleaned
* up while we are still trying to add it to lists, drop that one.
*/
if (event)
fsnotify_put_event(event);
+
+ return ret;
}
EXPORT_SYMBOL_GPL(fsnotify);
static __init int fsnotify_init(void)
{
- return init_srcu_struct(&fsnotify_grp_srcu);
+ int ret;
+
+ BUG_ON(hweight32(ALL_FSNOTIFY_EVENTS) != 23);
+
+ ret = init_srcu_struct(&fsnotify_mark_srcu);
+ if (ret)
+ panic("initializing fsnotify_mark_srcu");
+
+ return 0;
}
-subsys_initcall(fsnotify_init);
+core_initcall(fsnotify_init);
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