Re: [RFC PATCH -v4 00/14] fsnotify, dnotify, and inotify
From: Niraj Kumar
Date: Mon Dec 22 2008 - 05:58:58 EST
O Sun, Dec 21, 2008 at 10:22:06PM -0500, Eric Paris wrote:
> On Thu, 2008-12-18 at 18:36 -0500, C. Scott Ananian wrote:
> > On Fri, Dec 12, 2008 at 4:51 PM, Eric Paris <eparis@xxxxxxxxxx> wrote:
> > > The following series implements a new generic in kernel filesystem
> > > notification system, fsnotify. On top of fsnotify I reimplement dnotify and
> > > inotify. I have not finished with the change from inotify although I think
> > > inotify_user should be completed. In kernel inotify users (aka audit) still
> > > (until I get positive feedback) relay on the old inotify backend. This can be
> > > 'easily' fixed.
> > > All of this is in preperation for fanotify and using fanotify as an on access
> > > file scanner. So you better know it's coming.
Eric,
I was also getting my hands dirty with inotify (and friends)
but I see that you are already ahead. So, I thought I would
rather list my immediate requirements and see how far we can go with that.
My application is interested in only filesystem events (read/write/delete) but:
1) wants notification of only those events which are generated by the
calling process and it's children.
2) Subject to the constraint as mentioned above (1), it would be nice if I
can just say that I need to be notified of events on all filesystem
objects (perhaps within a namespace) rather than specifying each and
every file/dir that I am interested in. This is somewhat similar to the
"recursive watch" problem that others have mentioned.
The first part is fairly easy to achieve and I had already created a
patch for that on top of inotify. (See patch below). I was still
thinking about second part when I saw your patches. Can you tell me
whether your work is going to achive this? Maybe I can modify my
patch to work on top of what you are proposing ...
-Niraj
--------------------------------
Inotify: filter events only by the current process and it's children.
Adds a new flag (to be used with sys_inotify_init1) which
restricts notifications of only those events which has been
generated by the calling process and it's children.
This patch is on top of 2.6.28-rc5.
Signed-off-by: Niraj Kumar <niraj17@xxxxxxxxx>
diff --git a/fs/inotify.c b/fs/inotify.c
index 7bbed1b..f7ed34e 100644
--- a/fs/inotify.c
+++ b/fs/inotify.c
@@ -80,6 +80,8 @@ struct inotify_handle {
struct list_head watches; /* list of watches */
atomic_t count; /* reference count */
u32 last_wd; /* the last wd allocated */
+ struct task_struct *owner_task; /* owner task_struct */
+ u32 flags; /* operations flags */
const struct inotify_operations *in_ops; /* inotify caller operations */
};
@@ -310,6 +312,18 @@ void inotify_inode_queue_event(struct inode *inode, u32 mask, u32 cookie,
u32 watch_mask = watch->mask;
if (watch_mask & mask) {
struct inotify_handle *ih= watch->ih;
+ struct task_struct *curr = current;
+ int found = 0;
+ if (ih->flags & IN_ONLY_CHILD) {
+ for (curr = current; curr != &init_task;
+ curr = curr->parent)
+ if (ih->owner_task == curr) {
+ found = 1;
+ break;
+ }
+ if (!found)
+ continue;
+ }
mutex_lock(&ih->mutex);
if (watch_mask & IN_ONESHOT)
remove_watch_no_event(watch, ih);
@@ -467,7 +481,8 @@ EXPORT_SYMBOL_GPL(inotify_inode_is_dead);
* inotify_init - allocate and initialize an inotify instance
* @ops: caller's inotify operations
*/
-struct inotify_handle *inotify_init(const struct inotify_operations *ops)
+struct inotify_handle *inotify_init(const struct inotify_operations *ops,
+ int flags)
{
struct inotify_handle *ih;
@@ -479,6 +494,8 @@ struct inotify_handle *inotify_init(const struct inotify_operations *ops)
INIT_LIST_HEAD(&ih->watches);
mutex_init(&ih->mutex);
ih->last_wd = 0;
+ ih->owner_task = current;
+ ih->flags = flags;
ih->in_ops = ops;
atomic_set(&ih->count, 0);
get_inotify_handle(ih);
diff --git a/fs/inotify_user.c b/fs/inotify_user.c
index d367e9b..15359e3 100644
--- a/fs/inotify_user.c
+++ b/fs/inotify_user.c
@@ -588,7 +588,7 @@ asmlinkage long sys_inotify_init1(int flags)
BUILD_BUG_ON(IN_CLOEXEC != O_CLOEXEC);
BUILD_BUG_ON(IN_NONBLOCK != O_NONBLOCK);
- if (flags & ~(IN_CLOEXEC | IN_NONBLOCK))
+ if (flags & ~(IN_CLOEXEC | IN_NONBLOCK | IN_ONLY_CHILD))
return -EINVAL;
fd = get_unused_fd_flags(flags & O_CLOEXEC);
@@ -614,7 +614,7 @@ asmlinkage long sys_inotify_init1(int flags)
goto out_free_uid;
}
- ih = inotify_init(&inotify_user_ops);
+ ih = inotify_init(&inotify_user_ops, flags);
if (IS_ERR(ih)) {
ret = PTR_ERR(ih);
goto out_free_dev;
diff --git a/include/linux/inotify.h b/include/linux/inotify.h
index 37ea289..24adb0e 100644
--- a/include/linux/inotify.h
+++ b/include/linux/inotify.h
@@ -66,8 +66,10 @@ struct inotify_event {
IN_MOVE_SELF)
/* Flags for sys_inotify_init1. */
-#define IN_CLOEXEC O_CLOEXEC
-#define IN_NONBLOCK O_NONBLOCK
+#define IN_CLOEXEC O_CLOEXEC /* 02000000 */
+#define IN_NONBLOCK O_NONBLOCK /* 00004000 */
+#define IN_ONLY_CHILD 0x00000002 /* only notify event generated by this
+ process and children. */
#ifdef __KERNEL__
@@ -117,7 +119,8 @@ extern u32 inotify_get_cookie(void);
/* Kernel Consumer API */
-extern struct inotify_handle *inotify_init(const struct inotify_operations *);
+extern struct inotify_handle *inotify_init(const struct inotify_operations *,
+ int);
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 *,
diff --git a/kernel/audit.c b/kernel/audit.c
index 4414e93..c3c9e7d 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -983,7 +983,7 @@ static int __init audit_init(void)
audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized");
#ifdef CONFIG_AUDITSYSCALL
- audit_ih = inotify_init(&audit_inotify_ops);
+ audit_ih = inotify_init(&audit_inotify_ops, 0);
if (IS_ERR(audit_ih))
audit_panic("cannot initialize inotify handle");
#endif
diff --git a/kernel/audit_tree.c b/kernel/audit_tree.c
index 8b50944..e631b60 100644
--- a/kernel/audit_tree.c
+++ b/kernel/audit_tree.c
@@ -907,7 +907,7 @@ static int __init audit_tree_init(void)
{
int i;
- rtree_ih = inotify_init(&rtree_inotify_ops);
+ rtree_ih = inotify_init(&rtree_inotify_ops, 0);
if (IS_ERR(rtree_ih))
audit_panic("cannot initialize inotify handle for rectree watches");
--
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