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updated filesystem auditing patches for lspp test kernel

PATCH In review Amy Griffis 2 participants 4 messages Apr 7, 2006 – Apr 11, 2006

Subsystems (6)
VFS Scheduler Proc sysctl Audit +2 more subsystems
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#0 lore raw

PATCH 1/2 updated filesystem auditing patches for lspp test kernel

Updated Inotify kernel API patch, based on lspp.b6 branch.

For more details see:

    http://lkml.org/lkml/2006/4/6/96

Please include this patch in the next lspp test kernel.

 fs/Kconfig               |   24 -
 fs/Makefile              |    1 
 fs/inotify.c             |  966 ++++++++++++-----------------------------------
 fs/inotify_user.c        |  708 ++++++++++++++++++++++++++++++++++
 include/linux/fsnotify.h |   29 -
 include/linux/inotify.h  |   85 +++-
 include/linux/sched.h    |    2 
 kernel/sysctl.c          |    4 
 kernel/user.c            |    2 
 9 files changed, 1094 insertions(+), 727 deletions(-)
fs/Kconfig +18 -6
index e207be6..eda587d 100644
@@ -393,18 +393,30 @@ config INOTIFY
 	bool "Inotify file change notification support"
 	default y
 	---help---
-	  Say Y here to enable inotify support and the associated system
-	  calls.  Inotify is a file change notification system and a
-	  replacement for dnotify.  Inotify fixes numerous shortcomings in
-	  dnotify and introduces several new features.  It allows monitoring
-	  of both files and directories via a single open fd.  Other features
-	  include multiple file events, one-shot support, and unmount
+	  Say Y here to enable inotify support.  Inotify is a file change
+	  notification system and a replacement for dnotify.  Inotify fixes
+	  numerous shortcomings in dnotify and introduces several new features
+	  including multiple file events, one-shot support, and unmount
 	  notification.
 
 	  For more information, see Documentation/filesystems/inotify.txt
 
 	  If unsure, say Y.
 
+config INOTIFY_USER
+	bool "Inotify support for userspace"
+	depends on INOTIFY
+	default y
+	---help---
+	  Say Y here to enable inotify support for userspace, including the
+	  associated system calls.  Inotify allows monitoring of both files and
+	  directories via a single open fd.  Events are read from the file
+	  descriptor, which is also select()- and poll()-able.
+
+	  For more information, see Documentation/filesystems/inotify.txt
+
+	  If unsure, say Y.
+
 config QUOTA
 	bool "Quota support"
 	help
fs/Makefile +1 -0
index 83bf478..6d7b4be 100644
@@ -13,6 +13,7 @@ obj-y :=	open.o read_write.o file_table.
 		ioprio.o pnode.o drop_caches.o splice.o sync.o
 
 obj-$(CONFIG_INOTIFY)		+= inotify.o
+obj-$(CONFIG_INOTIFY_USER)	+= inotify_user.o
 obj-$(CONFIG_EPOLL)		+= eventpoll.o
 obj-$(CONFIG_COMPAT)		+= compat.o compat_ioctl.o
 
fs/inotify.c +265 -701

1,199 lines not on this page · raw message

fs/inotify_user.c new file +708 -0

708 lines not on this page · raw message

include/linux/fsnotify.h +16 -13
index 11438ef..a9d3044 100644
@@ -54,16 +54,18 @@ static inline void fsnotify_move(struct 
 
 	if (isdir)
 		isdir = IN_ISDIR;
-	inotify_inode_queue_event(old_dir, IN_MOVED_FROM|isdir,cookie,old_name);
-	inotify_inode_queue_event(new_dir, IN_MOVED_TO|isdir, cookie, new_name);
+	inotify_inode_queue_event(old_dir, IN_MOVED_FROM|isdir,cookie,old_name,
+				  source);
+	inotify_inode_queue_event(new_dir, IN_MOVED_TO|isdir, cookie, new_name,
+				  source);
 
 	if (target) {
-		inotify_inode_queue_event(target, IN_DELETE_SELF, 0, NULL);
+		inotify_inode_queue_event(target, IN_DELETE_SELF, 0, NULL, NULL);
 		inotify_inode_is_dead(target);
 	}
 
 	if (source) {
-		inotify_inode_queue_event(source, IN_MOVE_SELF, 0, NULL);
+		inotify_inode_queue_event(source, IN_MOVE_SELF, 0, NULL, NULL);
 	}
 	audit_inode_child(old_name, source, old_dir->i_ino);
 	audit_inode_child(new_name, target, new_dir->i_ino);
@@ -85,7 +87,7 @@ static inline void fsnotify_nameremove(s
  */
 static inline void fsnotify_inoderemove(struct inode *inode)
 {
-	inotify_inode_queue_event(inode, IN_DELETE_SELF, 0, NULL);
+	inotify_inode_queue_event(inode, IN_DELETE_SELF, 0, NULL, NULL);
 	inotify_inode_is_dead(inode);
 }
 
@@ -95,7 +97,8 @@ static inline void fsnotify_inoderemove(
 static inline void fsnotify_create(struct inode *inode, struct dentry *dentry)
 {
 	inode_dir_notify(inode, DN_CREATE);
-	inotify_inode_queue_event(inode, IN_CREATE, 0, dentry->d_name.name);
+	inotify_inode_queue_event(inode, IN_CREATE, 0, dentry->d_name.name,
+				  dentry->d_inode);
 	audit_inode_child(dentry->d_name.name, dentry->d_inode, inode->i_ino);
 }
 
@@ -106,7 +109,7 @@ static inline void fsnotify_mkdir(struct
 {
 	inode_dir_notify(inode, DN_CREATE);
 	inotify_inode_queue_event(inode, IN_CREATE | IN_ISDIR, 0, 
-				  dentry->d_name.name);
+				  dentry->d_name.name, dentry->d_inode);
 	audit_inode_child(dentry->d_name.name, dentry->d_inode, inode->i_ino);
 }
 
@@ -123,7 +126,7 @@ static inline void fsnotify_access(struc
 
 	dnotify_parent(dentry, DN_ACCESS);
 	inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name);
-	inotify_inode_queue_event(inode, mask, 0, NULL);
+	inotify_inode_queue_event(inode, mask, 0, NULL, NULL);
 }
 
 /*
@@ -139,7 +142,7 @@ static inline void fsnotify_modify(struc
 
 	dnotify_parent(dentry, DN_MODIFY);
 	inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name);
-	inotify_inode_queue_event(inode, mask, 0, NULL);
+	inotify_inode_queue_event(inode, mask, 0, NULL, NULL);
 }
 
 /*
@@ -154,7 +157,7 @@ static inline void fsnotify_open(struct 
 		mask |= IN_ISDIR;
 
 	inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name);
-	inotify_inode_queue_event(inode, mask, 0, NULL);	
+	inotify_inode_queue_event(inode, mask, 0, NULL, NULL);
 }
 
 /*
@@ -172,7 +175,7 @@ static inline void fsnotify_close(struct
 		mask |= IN_ISDIR;
 
 	inotify_dentry_parent_queue_event(dentry, mask, 0, name);
-	inotify_inode_queue_event(inode, mask, 0, NULL);
+	inotify_inode_queue_event(inode, mask, 0, NULL, NULL);
 }
 
 /*
@@ -187,7 +190,7 @@ static inline void fsnotify_xattr(struct
 		mask |= IN_ISDIR;
 
 	inotify_dentry_parent_queue_event(dentry, mask, 0, dentry->d_name.name);
-	inotify_inode_queue_event(inode, mask, 0, NULL);
+	inotify_inode_queue_event(inode, mask, 0, NULL, NULL);
 }
 
 /*
@@ -234,7 +237,7 @@ static inline void fsnotify_change(struc
 	if (in_mask) {
 		if (S_ISDIR(inode->i_mode))
 			in_mask |= IN_ISDIR;
-		inotify_inode_queue_event(inode, in_mask, 0, NULL);
+		inotify_inode_queue_event(inode, in_mask, 0, NULL, NULL);
 		inotify_dentry_parent_queue_event(dentry, in_mask, 0,
 						  dentry->d_name.name);
 	}
include/linux/inotify.h +82 -3

120 lines not on this page · raw message

include/linux/sched.h +1 -1
index 541f482..f48b8b1 100644
@@ -494,7 +494,7 @@ struct user_struct {
 	atomic_t processes;	/* How many processes does this user have? */
 	atomic_t files;		/* How many open files does this user have? */
 	atomic_t sigpending;	/* How many pending signals does this user have? */
-#ifdef CONFIG_INOTIFY
+#ifdef CONFIG_INOTIFY_USER
 	atomic_t inotify_watches; /* How many inotify watches does this user have? */
 	atomic_t inotify_devs;	/* How many inotify devs does this user have opened? */
 #endif
kernel/sysctl.c +2 -2
index e82726f..0d656e6 100644
@@ -150,7 +150,7 @@ extern ctl_table random_table[];
 #ifdef CONFIG_UNIX98_PTYS
 extern ctl_table pty_table[];
 #endif
-#ifdef CONFIG_INOTIFY
+#ifdef CONFIG_INOTIFY_USER
 extern ctl_table inotify_table[];
 #endif
 
@@ -1028,7 +1028,7 @@ static ctl_table fs_table[] = {
 		.mode		= 0644,
 		.proc_handler	= &proc_doulongvec_minmax,
 	},
-#ifdef CONFIG_INOTIFY
+#ifdef CONFIG_INOTIFY_USER
 	{
 		.ctl_name	= FS_INOTIFY,
 		.procname	= "inotify",
kernel/user.c +1 -1
index 2116642..4b1eb74 100644
@@ -140,7 +140,7 @@ struct user_struct * alloc_uid(uid_t uid
 		atomic_set(&new->processes, 0);
 		atomic_set(&new->files, 0);
 		atomic_set(&new->sigpending, 0);
-#ifdef CONFIG_INOTIFY
+#ifdef CONFIG_INOTIFY_USER
 		atomic_set(&new->inotify_watches, 0);
 		atomic_set(&new->inotify_devs, 0);
 #endif
#1 lore raw

Updated filesystem auditing patch based on lspp.b6 branch.

The following patch updates the previous filesystem auditing patch based on changes to the inotify kernel API.

Other changes include:
- use inotify_find_watch() instead of maintaining our own list of audit_parent structures
- add audit_add_rm_mutex to prevent add/remove rule races
- check for list_empty before calling inotify registration or de-registration routines

TODO
----
1. postpone some rule updates until exit filtering completes
2. add watch insertion path to audit record
3. remove inotify watches for moved parents

Please include this patch in the next lspp test kernel.

 include/linux/audit.h |    1 
 init/Kconfig          |    3 
 kernel/audit.c        |   19 -
 kernel/audit.h        |   22 +
 kernel/auditfilter.c  |  673 +++++++++++++++++++++++++++++++++++++++++++++++---
 kernel/auditsc.c      |   65 ++--
 6 files changed, 706 insertions(+), 77 deletions(-)
include/linux/audit.h +1 -0
index b74c148..e552ac4 100644
@@ -159,6 +159,7 @@
 #define AUDIT_INODE	102
 #define AUDIT_EXIT	103
 #define AUDIT_SUCCESS   104	/* exit >= 0; value ignored */
+#define AUDIT_WATCH	105
 
 #define AUDIT_ARG0      200
 #define AUDIT_ARG1      (AUDIT_ARG0+1)
init/Kconfig +2 -1
index 3b36a1d..c4d0fa6 100644
@@ -182,7 +182,8 @@ config AUDITSYSCALL
 	help
 	  Enable low-overhead system-call auditing infrastructure that
 	  can be used independently or with another kernel subsystem,
-	  such as SELinux.
+	  such as SELinux.  To use audit's filesystem watch feature, please
+	  ensure that INOTIFY is configured.
 
 config IKCONFIG
 	bool "Kernel .config support"
kernel/audit.c +11 -8
index df57b49..35b2c6f 100644
@@ -56,6 +56,7 @@
 #include <linux/skbuff.h>
 #include <linux/netlink.h>
 #include <linux/selinux.h>
+#include <linux/inotify.h>
 
 #include "audit.h"
 
@@ -102,6 +103,9 @@ static atomic_t    audit_lost = ATOMIC_I
 /* The netlink socket. */
 static struct sock *audit_sock;
 
+/* Inotify handle. */
+struct inotify_handle *audit_ih;
+
 /* The audit_freelist is a list of pre-allocated audit buffers (if more
  * than AUDIT_MAXFREE are in use, the audit buffer is freed instead of
  * being placed on the freelist). */
@@ -114,11 +118,6 @@ static struct task_struct *kauditd_task;
 static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait);
 static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait);
 
-/* The netlink socket is only to be read by 1 CPU, which lets us assume
- * that list additions and deletions never happen simultaneously in
- * auditsc.c */
-DEFINE_MUTEX(audit_netlink_mutex);
-
 /* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting
  * audit records.  Since printk uses a 1024 byte buffer, this buffer
  * should be at least that large. */
@@ -629,14 +628,11 @@ static void audit_receive(struct sock *s
 	struct sk_buff  *skb;
 	unsigned int qlen;
 
-	mutex_lock(&audit_netlink_mutex);
-
 	for (qlen = skb_queue_len(&sk->sk_receive_queue); qlen; qlen--) {
 		skb = skb_dequeue(&sk->sk_receive_queue);
 		audit_receive_skb(skb);
 		kfree_skb(skb);
 	}
-	mutex_unlock(&audit_netlink_mutex);
 }
 
 
@@ -661,6 +657,13 @@ static int __init audit_init(void)
 	selinux_audit_set_callback(&selinux_audit_rule_update);
 
 	audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized");
+
+#ifdef CONFIG_AUDITSYSCALL
+	audit_ih = inotify_init(audit_handle_ievent);
+	if (IS_ERR(audit_ih))
+		audit_panic("cannot initialize inotify handle");
+#endif
+
 	return 0;
 }
 __initcall(audit_init);
kernel/audit.h +19 -3
index 6f73392..1fe45e8 100644
@@ -19,7 +19,6 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
-#include <linux/mutex.h>
 #include <linux/fs.h>
 #include <linux/audit.h>
 
@@ -53,6 +52,18 @@ enum audit_state {
 };
 
 /* Rule lists */
+struct audit_parent;
+
+struct audit_watch {
+	atomic_t		count;	/* reference count */
+	char			*path;	/* insertion path */
+	dev_t			dev;	/* associated superblock device */
+	unsigned long		ino;	/* associated inode number */
+	struct audit_parent	*parent; /* associated parent */
+	struct list_head	wlist;	/* entry in parent->watches list */
+	struct list_head	rules;	/* associated rules */
+};
+
 struct audit_field {
 	u32				type;
 	u32				val;
@@ -70,6 +81,8 @@ struct audit_krule {
 	u32			buflen; /* for data alloc on list rules */
 	u32			field_count;
 	struct audit_field	*fields;
+	struct audit_watch	*watch;	/* associated watch */
+	struct list_head	rlist;	/* entry in audit_watch.rules list */
 };
 
 struct audit_entry {
@@ -81,12 +94,15 @@ struct audit_entry {
 
 extern int audit_pid;
 extern int audit_comparator(const u32 left, const u32 op, const u32 right);
-
+extern int audit_compare_dname_path(const char *dname, const char *path);
 extern void		    audit_send_reply(int pid, int seq, int type,
 					     int done, int multi,
 					     void *payload, int size);
 extern void		    audit_log_lost(const char *message);
 extern void		    audit_panic(const char *message);
-extern struct mutex audit_netlink_mutex;
 
+struct inotify_watch;
+extern void audit_handle_ievent(struct inotify_watch *, u32, u32, u32,
+				const char *, struct inode *);
 extern int selinux_audit_rule_update(void);
+
kernel/auditfilter.c +637 -36

859 lines not on this page · raw message

kernel/auditsc.c +36 -29

85 lines not on this page · raw message

#2 lore raw

Hard to give this a meaningful review - particularly the first patch, a large part of which seemed to be moving functionality from one file to another. But slowly reading along, at least this smells like an error:

Quoted 8 lines · Amy Griffis
kernel/auditfilter.c +8 -0
+/* Initialize a watch entry. */
+static inline struct audit_watch *audit_init_watch(char *path)
+{
+	struct audit_watch *watch;
+
+	watch = kzalloc(sizeof(*watch), GFP_KERNEL);
+	if (unlikely(!watch))
+		return ERR_PTR(-ENOMEM);

...

kernel/auditfilter.c static char *audit_unpack_string(void ** · line 263

Quoted 3 lines
kernel/auditfilter.c +3 -0
+	watch = audit_init_watch(path);
+	if (unlikely(IS_ERR(watch)))
+		return PTR_ERR(watch);

Ok, but

kernel/auditfilter.c static int audit_compare_rule(struct aud · line 591

Quoted 5 lines
kernel/auditfilter.c +5 -0
+	new = audit_init_watch(path);
+	if (unlikely(!new)) {
+		kfree(path);
+		return ERR_PTR(-ENOMEM);
+	}

not ok

-serge

#3 lore raw

Serge E. Hallyn wrote: [Mon Apr 10 2006, 01:56:26PM EDT]

Quoted 3 lines

Hard to give this a meaningful review - particularly the first patch, a large part of which seemed to be moving functionality from one file to another.

FWIW, it may help to diff inotify_user.c against an unpatched inotify.c (included below for reference). The essence of the inotify patch is *how* the current functionality is split between kernel API and userspace support. There isn't much new code.

Quoted 16 lines · Amy Griffis
Quoted 8 lines
(quoted diff) +8 -0
+/* Initialize a watch entry. */
+static inline struct audit_watch *audit_init_watch(char *path)
+{
+	struct audit_watch *watch;
+
+	watch = kzalloc(sizeof(*watch), GFP_KERNEL);
+	if (unlikely(!watch))
+		return ERR_PTR(-ENOMEM);

...

Review

Quoted 3 lines
(quoted diff) +3 -0
+	watch = audit_init_watch(path);
+	if (unlikely(IS_ERR(watch)))
+		return PTR_ERR(watch);

Ok, but

Quoted 7 lines

Review

Quoted 5 lines
(quoted diff) +5 -0
+	new = audit_init_watch(path);
+	if (unlikely(!new)) {
+		kfree(path);
+		return ERR_PTR(-ENOMEM);
+	}

not ok

thanks

fs/inotify_user.c renamed from fs/inotify.c +100 -539
@@ -18,11 +18,8 @@
  * General Public License for more details.
  */
 
-#include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/sched.h>
-#include <linux/spinlock.h>
-#include <linux/idr.h>
 #include <linux/slab.h>
 #include <linux/fs.h>
 #include <linux/file.h>
@@ -31,14 +28,11 @@
 #include <linux/poll.h>
 #include <linux/init.h>
 #include <linux/list.h>
-#include <linux/writeback.h>
 #include <linux/inotify.h>
 #include <linux/syscalls.h>
 
 #include <asm/ioctls.h>
 
-static atomic_t inotify_cookie;
-
 static kmem_cache_t *watch_cachep __read_mostly;
 static kmem_cache_t *event_cachep __read_mostly;
 
@@ -52,27 +46,21 @@ int inotify_max_queued_events __read_mos
 /*
  * Lock ordering:
  *
- * dentry->d_lock (used to keep d_move() away from dentry->d_parent)
- * iprune_mutex (synchronize shrink_icache_memory())
- * 	inode_lock (protects the super_block->s_inodes list)
- * 	inode->inotify_mutex (protects inode->inotify_watches and watches->i_list)
- * 		inotify_dev->mutex (protects inotify_device and watches->d_list)
+ * inotify_dev->up_mutex (ensures we don't re-add the same watch)
+ * 	inode->inotify_mutex (protects inode's watch list)
+ * 		inotify_handle->mutex (protects inotify_handle's watch list)
+ * 			inotify_dev->ev_mutex (protects device's event queue)
  */
 
 /*
- * Lifetimes of the three main data structures--inotify_device, inode, and
- * inotify_watch--are managed by reference count.
- *
- * inotify_device: Lifetime is from inotify_init() until release.  Additional
- * references can bump the count via get_inotify_dev() and drop the count via
- * put_inotify_dev().
+ * Lifetimes of the main data structures:
  *
- * inotify_watch: Lifetime is from create_watch() to destory_watch().
- * Additional references can bump the count via get_inotify_watch() and drop
- * the count via put_inotify_watch().
+ * inotify_device: Lifetime is managed by reference count, from
+ * sys_inotify_init() until release.  Additional references can bump the count
+ * via get_inotify_dev() and drop the count via put_inotify_dev().
  *
- * inode: Pinned so long as the inode is associated with a watch, from
- * create_watch() to put_inotify_watch().
+ * inotify_user_watch: Lifetime is from create_watch() to the receipt of an
+ * IN_IGNORED event from inotify.
  */
 
 /*
@@ -82,16 +70,15 @@ int inotify_max_queued_events __read_mos
  */
 struct inotify_device {
 	wait_queue_head_t 	wq;		/* wait queue for i/o */
-	struct idr		idr;		/* idr mapping wd -> watch */
-	struct mutex		mutex;		/* protects this bad boy */
+	struct mutex		ev_mutex;	/* protects event queue */
+	struct mutex		up_mutex;	/* synchronizes watch updates */
 	struct list_head 	events;		/* list of queued events */
-	struct list_head	watches;	/* list of watches */
 	atomic_t		count;		/* reference count */
 	struct user_struct	*user;		/* user who opened this dev */
+	struct inotify_handle	*ih;		/* inotify handle */
 	unsigned int		queue_size;	/* size of the queue (bytes) */
 	unsigned int		event_count;	/* number of pending events */
 	unsigned int		max_events;	/* maximum number of events */
-	u32			last_wd;	/* the last wd allocated */
 };
 
 /*
@@ -100,7 +87,7 @@ struct inotify_device {
  * device.  In read(), this list is walked and all events that can fit in the
  * buffer are returned.
  *
- * Protected by dev->mutex of the device in which we are queued.
+ * Protected by dev->ev_mutex of the device in which we are queued.
  */
 struct inotify_kernel_event {
 	struct inotify_event	event;	/* the user-space event */
@@ -109,20 +96,12 @@ struct inotify_kernel_event {
 };
 
 /*
- * struct inotify_watch - represents a watch request on a specific inode
- *
- * d_list is protected by dev->mutex of the associated watch->dev.
- * i_list and mask are protected by inode->inotify_mutex of the associated inode.
- * dev, inode, and wd are never written to once the watch is created.
+ * struct inotify_user_watch - our version of an inotify_watch, we add
+ * a reference to the associated inotify_device.
  */
-struct inotify_watch {
-	struct list_head	d_list;	/* entry in inotify_device's list */
-	struct list_head	i_list;	/* entry in inode's list */
-	atomic_t		count;	/* reference count */
+struct inotify_user_watch {
 	struct inotify_device	*dev;	/* associated device */
-	struct inode		*inode;	/* associated inode */
-	s32 			wd;	/* watch descriptor */
-	u32			mask;	/* event mask for this watch */
+	struct inotify_watch	wdata;	/* inotify watch data */
 };
 
 #ifdef CONFIG_SYSCTL
@@ -150,16 +129,16 @@ ctl_table inotify_table[] = {
 		.mode		= 0644,
 		.proc_handler	= &proc_dointvec_minmax,
 		.strategy	= &sysctl_intvec,
-		.extra1		= &zero, 
+		.extra1		= &zero,
 	},
 	{
 		.ctl_name	= INOTIFY_MAX_QUEUED_EVENTS,
 		.procname	= "max_queued_events",
 		.data		= &inotify_max_queued_events,
 		.maxlen		= sizeof(int),
-		.mode		= 0644, 
+		.mode		= 0644,
 		.proc_handler	= &proc_dointvec_minmax,
-		.strategy	= &sysctl_intvec, 
+		.strategy	= &sysctl_intvec,
 		.extra1		= &zero
 	},
 	{ .ctl_name = 0 }
@@ -176,27 +155,20 @@ static inline void put_inotify_dev(struc
 	if (atomic_dec_and_test(&dev->count)) {
 		atomic_dec(&dev->user->inotify_devs);
 		free_uid(dev->user);
-		idr_destroy(&dev->idr);
 		kfree(dev);
 	}
 }
 
-static inline void get_inotify_watch(struct inotify_watch *watch)
-{
-	atomic_inc(&watch->count);
-}
-
 /*
- * put_inotify_watch - decrements the ref count on a given watch.  cleans up
- * the watch and its references if the count reaches zero.
+ * free_inotify_user_watch - * cleans up the watch and its references
  */
-static inline void put_inotify_watch(struct inotify_watch *watch)
+static inline void free_inotify_user_watch(struct inotify_user_watch *watch)
 {
-	if (atomic_dec_and_test(&watch->count)) {
-		put_inotify_dev(watch->dev);
-		iput(watch->inode);
-		kmem_cache_free(watch_cachep, watch);
-	}
+	struct inotify_device *dev = watch->dev;
+
+	atomic_dec(&dev->user->inotify_watches);
+	put_inotify_dev(dev);
+	kmem_cache_free(watch_cachep, watch);
 }
 
 /*
@@ -247,7 +219,7 @@ static struct inotify_kernel_event * ker
 		}
 		memcpy(kevent->name, name, len);
 		if (rem)
-			memset(kevent->name + len, 0, rem);		
+			memset(kevent->name + len, 0, rem);
 		kevent->event.len = len + rem;
 	} else {
 		kevent->event.len = 0;
@@ -260,7 +232,7 @@ static struct inotify_kernel_event * ker
 /*
  * inotify_dev_get_event - return the next event in the given dev's queue
  *
- * Caller must hold dev->mutex.
+ * Caller must hold dev->ev_mutex.
  */
 static inline struct inotify_kernel_event *
 inotify_dev_get_event(struct inotify_device *dev)
@@ -269,19 +241,33 @@ inotify_dev_get_event(struct inotify_dev
 }
 
 /*
- * inotify_dev_queue_event - add a new event to the given device
+ * inotify_dev_queue_event - event callback registered with core inotify, adds
+ * a new event to the given device
  *
- * Caller must hold dev->mutex.  Can sleep (calls kernel_event()).
+ * Can sleep (calls kernel_event()).
  */
-static void inotify_dev_queue_event(struct inotify_device *dev,
-				    struct inotify_watch *watch, u32 mask,
-				    u32 cookie, const char *name)
+static void inotify_dev_queue_event(struct inotify_watch *w, u32 wd, u32 mask,
+				    u32 cookie, const char *name,
+				    struct inode *ignored)
 {
+	struct inotify_user_watch *watch;
+	struct inotify_device *dev;
 	struct inotify_kernel_event *kevent, *last;
 
+	watch = container_of(w, struct inotify_user_watch, wdata);
+	dev = watch->dev;
+
+	mutex_lock(&dev->ev_mutex);
+
+	/* we can safely put the watch as we don't reference it while
+	 * generating the event
+	 */
+	if (mask & IN_IGNORED)
+		free_inotify_user_watch(watch);
+
 	/* coalescing: drop this event if it is a dupe of the previous */
 	last = inotify_dev_get_event(dev);
-	if (last && last->event.mask == mask && last->event.wd == watch->wd &&
+	if (last && last->event.mask == mask && last->event.wd == wd &&
 			last->event.cookie == cookie) {
 		const char *lastname = last->name;
 
@@ -299,7 +285,7 @@ static void inotify_dev_queue_event(stru
 	if (unlikely(dev->event_count == dev->max_events))
 		kevent = kernel_event(-1, IN_Q_OVERFLOW, cookie, NULL);
 	else
-		kevent = kernel_event(watch->wd, mask, cookie, name);
+		kevent = kernel_event(wd, mask, cookie, name);
 
 	if (unlikely(!kevent))
 		return;
@@ -309,12 +295,14 @@ static void inotify_dev_queue_event(stru
 	dev->queue_size += sizeof(struct inotify_event) + kevent->event.len;
 	list_add_tail(&kevent->list, &dev->events);
 	wake_up_interruptible(&dev->wq);
+
+	mutex_unlock(&dev->ev_mutex);
 }
 
 /*
  * remove_kevent - cleans up and ultimately frees the given kevent
  *
- * Caller must hold dev->mutex.
+ * Caller must hold dev->ev_mutex.
  */
 static void remove_kevent(struct inotify_device *dev,
 			  struct inotify_kernel_event *kevent)
@@ -331,7 +319,7 @@ static void remove_kevent(struct inotify
 /*
  * inotify_dev_event_dequeue - destroy an event on the given device
  *
- * Caller must hold dev->mutex.
+ * Caller must hold dev->ev_mutex.
  */
 static void inotify_dev_event_dequeue(struct inotify_device *dev)
 {
@@ -343,25 +331,6 @@ static void inotify_dev_event_dequeue(st
 }
 
 /*
- * inotify_dev_get_wd - returns the next WD for use by the given dev
- *
- * Callers must hold dev->mutex.  This function can sleep.
- */
-static int inotify_dev_get_wd(struct inotify_device *dev,
-			      struct inotify_watch *watch)
-{
-	int ret;
-
-	do {
-		if (unlikely(!idr_pre_get(&dev->idr, GFP_KERNEL)))
-			return -ENOSPC;
-		ret = idr_get_new_above(&dev->idr, watch, dev->last_wd+1, &watch->wd);
-	} while (ret == -EAGAIN);
-
-	return ret;
-}
-
-/*
  * find_inode - resolve a user-given path to a specific inode and return a nd
  */
 static int find_inode(const char __user *dirname, struct nameidata *nd,
@@ -374,359 +343,45 @@ static int find_inode(const char __user 
 		return error;
 	/* you can only watch an inode if you have read permissions on it */
 	error = vfs_permission(nd, MAY_READ);
-	if (error) 
+	if (error)
 		path_release(nd);
 	return error;
 }
 
 /*
- * inotify_inode_watched - returns nonzero if there are watches on this inode
- * and zero otherwise.  We call this lockless, we do not care if we race.
- */
-static inline int inotify_inode_watched(struct inode *inode)
-{
-	return !list_empty(&inode->inotify_watches);
-}
-
-/*
- * Get child dentry flag into synch with parent inode.
- * Flag should always be clear for negative dentrys.
- */
-static void set_dentry_child_flags(struct inode *inode, int watched)
-{
-	struct dentry *alias;
-
-	spin_lock(&dcache_lock);
-	list_for_each_entry(alias, &inode->i_dentry, d_alias) {
-		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);
-				continue;
-			}
-			spin_lock(&child->d_lock);
-			if (watched) {
-				WARN_ON(child->d_flags &
-						DCACHE_INOTIFY_PARENT_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;
-			}
-			spin_unlock(&child->d_lock);
-		}
-	}
-	spin_unlock(&dcache_lock);
-}
-
-/*
  * create_watch - creates a watch on the given device.
  *
- * Callers must hold dev->mutex.  Calls inotify_dev_get_wd() so may sleep.
- * Both 'dev' and 'inode' (by way of nameidata) need to be pinned.
+ * Callers must hold dev->up_mutex.
  */
-static struct inotify_watch *create_watch(struct inotify_device *dev,
-					  u32 mask, struct inode *inode)
+static int create_watch(struct inotify_device *dev, struct inode *inode,
+			u32 mask)
 {
-	struct inotify_watch *watch;
+	struct inotify_user_watch *watch;
 	int ret;
 
 	if (atomic_read(&dev->user->inotify_watches) >=
 			inotify_max_user_watches)
-		return ERR_PTR(-ENOSPC);
+		return -ENOSPC;
 
 	watch = kmem_cache_alloc(watch_cachep, GFP_KERNEL);
 	if (unlikely(!watch))
-		return ERR_PTR(-ENOMEM);
-
-	ret = inotify_dev_get_wd(dev, watch);
-	if (unlikely(ret)) {
-		kmem_cache_free(watch_cachep, watch);
-		return ERR_PTR(ret);
-	}
-
-	dev->last_wd = watch->wd;
-	watch->mask = mask;
-	atomic_set(&watch->count, 0);
-	INIT_LIST_HEAD(&watch->d_list);
-	INIT_LIST_HEAD(&watch->i_list);
+		return -ENOMEM;
 
 	/* save a reference to device and bump the count to make it official */
 	get_inotify_dev(dev);
 	watch->dev = dev;
 
-	/*
-	 * Save a reference to the inode and bump the ref count to make it
-	 * official.  We hold a reference to nameidata, which makes this safe.
-	 */
-	watch->inode = igrab(inode);
-
-	/* bump our own count, corresponding to our entry in dev->watches */
-	get_inotify_watch(watch);
-
 	atomic_inc(&dev->user->inotify_watches);
 
-	return watch;
-}
-
-/*
- * inotify_find_dev - find the watch associated with the given inode and dev
- *
- * Callers must hold inode->inotify_mutex.
- */
-static struct inotify_watch *inode_find_dev(struct inode *inode,
-					    struct inotify_device *dev)
-{
-	struct inotify_watch *watch;
-
-	list_for_each_entry(watch, &inode->inotify_watches, i_list) {
-		if (watch->dev == dev)
-			return watch;
-	}
-
-	return NULL;
-}
-
-/*
- * remove_watch_no_event - remove_watch() without the IN_IGNORED event.
- */
-static void remove_watch_no_event(struct inotify_watch *watch,
-				  struct inotify_device *dev)
-{
-	list_del(&watch->i_list);
-	list_del(&watch->d_list);
-
-	if (!inotify_inode_watched(watch->inode))
-		set_dentry_child_flags(watch->inode, 0);
+	ret = inotify_add_watch(dev->ih, &watch->wdata, inode, mask);
+	if (ret < 0)
+		free_inotify_user_watch(watch);
 
-	atomic_dec(&dev->user->inotify_watches);
-	idr_remove(&dev->idr, watch->wd);
-	put_inotify_watch(watch);
-}
-
-/*
- * remove_watch - Remove a watch from both the device and the inode.  Sends
- * the IN_IGNORED event to the given device signifying that the inode is no
- * longer watched.
- *
- * Callers must hold both inode->inotify_mutex and dev->mutex.  We drop a
- * reference to the inode before returning.
- *
- * The inode is not iput() so as to remain atomic.  If the inode needs to be
- * iput(), the call returns one.  Otherwise, it returns zero.
- */
-static void remove_watch(struct inotify_watch *watch,struct inotify_device *dev)
-{
-	inotify_dev_queue_event(dev, watch, IN_IGNORED, 0, NULL);
-	remove_watch_no_event(watch, dev);
+	return ret;
 }
 
 /* Kernel API */
 
-/*
- * inotify_d_instantiate - instantiate dcache entry for inode
- */
-void inotify_d_instantiate(struct dentry *entry, struct inode *inode)
-{
-	struct dentry *parent;
-
-	if (!inode)
-		return;
-
-	WARN_ON(entry->d_flags & DCACHE_INOTIFY_PARENT_WATCHED);
-	spin_lock(&entry->d_lock);
-	parent = entry->d_parent;
-	if (inotify_inode_watched(parent->d_inode))
-		entry->d_flags |= DCACHE_INOTIFY_PARENT_WATCHED;
-	spin_unlock(&entry->d_lock);
-}
-
-/*
- * inotify_d_move - dcache entry has been moved
- */
-void inotify_d_move(struct dentry *entry)
-{
-	struct dentry *parent;
-
-	parent = entry->d_parent;
-	if (inotify_inode_watched(parent->d_inode))
-		entry->d_flags |= DCACHE_INOTIFY_PARENT_WATCHED;
-	else
-		entry->d_flags &= ~DCACHE_INOTIFY_PARENT_WATCHED;
-}
-
-/**
- * inotify_inode_queue_event - queue an event to all watches on this inode
- * @inode: inode event is originating from
- * @mask: event mask describing this event
- * @cookie: cookie for synchronization, or zero
- * @name: filename, if any
- */
-void inotify_inode_queue_event(struct inode *inode, u32 mask, u32 cookie,
-			       const char *name)
-{
-	struct inotify_watch *watch, *next;
-
-	if (!inotify_inode_watched(inode))
-		return;
-
-	mutex_lock(&inode->inotify_mutex);
-	list_for_each_entry_safe(watch, next, &inode->inotify_watches, i_list) {
-		u32 watch_mask = watch->mask;
-		if (watch_mask & mask) {
-			struct inotify_device *dev = watch->dev;
-			get_inotify_watch(watch);
-			mutex_lock(&dev->mutex);
-			inotify_dev_queue_event(dev, watch, mask, cookie, name);
-			if (watch_mask & IN_ONESHOT)
-				remove_watch_no_event(watch, dev);
-			mutex_unlock(&dev->mutex);
-			put_inotify_watch(watch);
-		}
-	}
-	mutex_unlock(&inode->inotify_mutex);
-}
-EXPORT_SYMBOL_GPL(inotify_inode_queue_event);
-
-/**
- * inotify_dentry_parent_queue_event - queue an event to a dentry's parent
- * @dentry: the dentry in question, we queue against this dentry's parent
- * @mask: event mask describing this event
- * @cookie: cookie for synchronization, or zero
- * @name: filename, if any
- */
-void inotify_dentry_parent_queue_event(struct dentry *dentry, u32 mask,
-				       u32 cookie, const char *name)
-{
-	struct dentry *parent;
-	struct inode *inode;
-
-	if (!(dentry->d_flags & DCACHE_INOTIFY_PARENT_WATCHED))
-		return;
-
-	spin_lock(&dentry->d_lock);
-	parent = dentry->d_parent;
-	inode = parent->d_inode;
-
-	if (inotify_inode_watched(inode)) {
-		dget(parent);
-		spin_unlock(&dentry->d_lock);
-		inotify_inode_queue_event(inode, mask, cookie, name);
-		dput(parent);
-	} else
-		spin_unlock(&dentry->d_lock);
-}
-EXPORT_SYMBOL_GPL(inotify_dentry_parent_queue_event);
-
-/**
- * inotify_get_cookie - return a unique cookie for use in synchronizing events.
- */
-u32 inotify_get_cookie(void)
-{
-	return atomic_inc_return(&inotify_cookie);
-}
-EXPORT_SYMBOL_GPL(inotify_get_cookie);
-
-/**
- * inotify_unmount_inodes - an sb is unmounting.  handle any watched inodes.
- * @list: list of inodes being unmounted (sb->s_inodes)
- *
- * Called with inode_lock held, protecting the unmounting super block's list
- * of inodes, and with iprune_mutex held, keeping shrink_icache_memory() at bay.
- * We temporarily drop inode_lock, however, and CAN block.
- */
-void inotify_unmount_inodes(struct list_head *list)
-{
-	struct inode *inode, *next_i, *need_iput = NULL;
-
-	list_for_each_entry_safe(inode, next_i, list, i_sb_list) {
-		struct inotify_watch *watch, *next_w;
-		struct inode *need_iput_tmp;
-		struct list_head *watches;
-
-		/*
-		 * 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))
-			continue;
-
-		/*
-		 * We cannot __iget() an inode in state I_CLEAR, I_FREEING, or
-		 * I_WILL_FREE which is fine because by that point the inode
-		 * cannot have any associated watches.
-		 */
-		if (inode->i_state & (I_CLEAR | I_FREEING | I_WILL_FREE))
-			continue;
-
-		need_iput_tmp = need_iput;
-		need_iput = NULL;
-		/* In case the remove_watch() drops a reference. */
-		if (inode != need_iput_tmp)
-			__iget(inode);
-		else
-			need_iput_tmp = NULL;
-		/* In case the dropping of a reference would nuke next_i. */
-		if ((&next_i->i_sb_list != list) &&
-				atomic_read(&next_i->i_count) &&
-				!(next_i->i_state & (I_CLEAR | I_FREEING |
-					I_WILL_FREE))) {
-			__iget(next_i);
-			need_iput = next_i;
-		}
-
-		/*
-		 * We can safely drop inode_lock here because we hold
-		 * references on both inode and next_i.  Also no new inodes
-		 * will be added since the umount has begun.  Finally,
-		 * iprune_mutex keeps shrink_icache_memory() away.
-		 */
-		spin_unlock(&inode_lock);
-
-		if (need_iput_tmp)
-			iput(need_iput_tmp);
-
-		/* for each watch, send IN_UNMOUNT and then remove it */
-		mutex_lock(&inode->inotify_mutex);
-		watches = &inode->inotify_watches;
-		list_for_each_entry_safe(watch, next_w, watches, i_list) {
-			struct inotify_device *dev = watch->dev;
-			mutex_lock(&dev->mutex);
-			inotify_dev_queue_event(dev, watch, IN_UNMOUNT,0,NULL);
-			remove_watch(watch, dev);
-			mutex_unlock(&dev->mutex);
-		}
-		mutex_unlock(&inode->inotify_mutex);
-		iput(inode);		
-
-		spin_lock(&inode_lock);
-	}
-}
-EXPORT_SYMBOL_GPL(inotify_unmount_inodes);
-
-/**
- * inotify_inode_is_dead - an inode has been deleted, cleanup any watches
- * @inode: inode that is about to be removed
- */
-void inotify_inode_is_dead(struct inode *inode)
-{
-	struct inotify_watch *watch, *next;
-
-	mutex_lock(&inode->inotify_mutex);
-	list_for_each_entry_safe(watch, next, &inode->inotify_watches, i_list) {
-		struct inotify_device *dev = watch->dev;
-		mutex_lock(&dev->mutex);
-		remove_watch(watch, dev);
-		mutex_unlock(&dev->mutex);
-	}
-	mutex_unlock(&inode->inotify_mutex);
-}
-EXPORT_SYMBOL_GPL(inotify_inode_is_dead);
-
 /* Device Interface */
 
 static unsigned int inotify_poll(struct file *file, poll_table *wait)
@@ -735,10 +390,10 @@ static unsigned int inotify_poll(struct 
 	int ret = 0;
 
 	poll_wait(file, &dev->wq, wait);
-	mutex_lock(&dev->mutex);
+	mutex_lock(&dev->ev_mutex);
 	if (!list_empty(&dev->events))
 		ret = POLLIN | POLLRDNORM;
-	mutex_unlock(&dev->mutex);
+	mutex_unlock(&dev->ev_mutex);
 
 	return ret;
 }
@@ -760,9 +415,9 @@ static ssize_t inotify_read(struct file 
 
 		prepare_to_wait(&dev->wq, &wait, TASK_INTERRUPTIBLE);
 
-		mutex_lock(&dev->mutex);
+		mutex_lock(&dev->ev_mutex);
 		events = !list_empty(&dev->events);
-		mutex_unlock(&dev->mutex);
+		mutex_unlock(&dev->ev_mutex);
 		if (events) {
 			ret = 0;
 			break;
@@ -785,7 +440,7 @@ static ssize_t inotify_read(struct file 
 	if (ret)
 		return ret;
 
-	mutex_lock(&dev->mutex);
+	mutex_lock(&dev->ev_mutex);
 	while (1) {
 		struct inotify_kernel_event *kevent;
 
@@ -815,7 +470,7 @@ static ssize_t inotify_read(struct file 
 
 		remove_kevent(dev, kevent);
 	}
-	mutex_unlock(&dev->mutex);
+	mutex_unlock(&dev->ev_mutex);
 
 	return ret;
 }
@@ -824,41 +479,13 @@ static int inotify_release(struct inode 
 {
 	struct inotify_device *dev = file->private_data;
 
-	/*
-	 * Destroy all of the watches on this device.  Unfortunately, not very
-	 * pretty.  We cannot do a simple iteration over the list, because we
-	 * do not know the inode until we iterate to the watch.  But we need to
-	 * hold inode->inotify_mutex before dev->mutex.  The following works.
-	 */
-	while (1) {
-		struct inotify_watch *watch;
-		struct list_head *watches;
-		struct inode *inode;
-
-		mutex_lock(&dev->mutex);
-		watches = &dev->watches;
-		if (list_empty(watches)) {
-			mutex_unlock(&dev->mutex);
-			break;
-		}
-		watch = list_entry(watches->next, struct inotify_watch, d_list);
-		get_inotify_watch(watch);
-		mutex_unlock(&dev->mutex);
-
-		inode = watch->inode;
-		mutex_lock(&inode->inotify_mutex);
-		mutex_lock(&dev->mutex);
-		remove_watch_no_event(watch, dev);
-		mutex_unlock(&dev->mutex);
-		mutex_unlock(&inode->inotify_mutex);
-		put_inotify_watch(watch);
-	}
+	inotify_destroy(dev->ih);
 
 	/* destroy all of the events on this device */
-	mutex_lock(&dev->mutex);
+	mutex_lock(&dev->ev_mutex);
 	while (!list_empty(&dev->events))
 		inotify_dev_event_dequeue(dev);
-	mutex_unlock(&dev->mutex);
+	mutex_unlock(&dev->ev_mutex);
 
 	/* free this device: the put matching the get in inotify_init() */
 	put_inotify_dev(dev);
@@ -866,41 +493,6 @@ static int inotify_release(struct inode 
 	return 0;
 }
 
-/*
- * inotify_ignore - remove a given wd from this inotify instance.
- *
- * Can sleep.
- */
-static int inotify_ignore(struct inotify_device *dev, s32 wd)
-{
-	struct inotify_watch *watch;
-	struct inode *inode;
-
-	mutex_lock(&dev->mutex);
-	watch = idr_find(&dev->idr, wd);
-	if (unlikely(!watch)) {
-		mutex_unlock(&dev->mutex);
-		return -EINVAL;
-	}
-	get_inotify_watch(watch);
-	inode = watch->inode;
-	mutex_unlock(&dev->mutex);
-
-	mutex_lock(&inode->inotify_mutex);
-	mutex_lock(&dev->mutex);
-
-	/* make sure that we did not race */
-	watch = idr_find(&dev->idr, wd);
-	if (likely(watch))
-		remove_watch(watch, dev);
-
-	mutex_unlock(&dev->mutex);
-	mutex_unlock(&inode->inotify_mutex);
-	put_inotify_watch(watch);
-
-	return 0;
-}
-
 static long inotify_ioctl(struct file *file, unsigned int cmd,
 			  unsigned long arg)
 {
@@ -931,8 +523,9 @@ static const struct file_operations inot
 asmlinkage long sys_inotify_init(void)
 {
 	struct inotify_device *dev;
+	struct inotify_handle *ih;
 	struct user_struct *user;
-	struct file *filp;	
+	struct file *filp;
 	int fd, ret;
 
 	fd = get_unused_fd();
@@ -958,6 +551,13 @@ asmlinkage long sys_inotify_init(void)
 		goto out_free_uid;
 	}
 
+	ih = inotify_init(inotify_dev_queue_event);
+	if (unlikely(IS_ERR(ih))) {
+		ret = PTR_ERR(ih);
+		goto out_free_dev;
+	}
+	dev->ih = ih;
+
 	filp->f_op = &inotify_fops;
 	filp->f_vfsmnt = mntget(inotify_mnt);
 	filp->f_dentry = dget(inotify_mnt->mnt_root);
@@ -966,16 +566,14 @@ asmlinkage long sys_inotify_init(void)
 	filp->f_flags = O_RDONLY;
 	filp->private_data = dev;
 
-	idr_init(&dev->idr);
 	INIT_LIST_HEAD(&dev->events);
-	INIT_LIST_HEAD(&dev->watches);
 	init_waitqueue_head(&dev->wq);
-	mutex_init(&dev->mutex);
+	mutex_init(&dev->ev_mutex);
+	mutex_init(&dev->up_mutex);
 	dev->event_count = 0;
 	dev->queue_size = 0;
 	dev->max_events = inotify_max_queued_events;
 	dev->user = user;
-	dev->last_wd = 0;
 	atomic_set(&dev->count, 0);
 
 	get_inotify_dev(dev);
@@ -983,6 +581,8 @@ asmlinkage long sys_inotify_init(void)
 	fd_install(fd, filp);
 
 	return fd;
+out_free_dev:
+	kfree(dev);
 out_free_uid:
 	free_uid(user);
 	put_filp(filp);
@@ -993,13 +593,11 @@ out_put_fd:
 
 asmlinkage long sys_inotify_add_watch(int fd, const char __user *path, u32 mask)
 {
-	struct inotify_watch *watch, *old;
 	struct inode *inode;
 	struct inotify_device *dev;
 	struct nameidata nd;
 	struct file *filp;
 	int ret, fput_needed;
-	int mask_add = 0;
 	unsigned flags = 0;
 
 	filp = fget_light(fd, &fput_needed);
@@ -1025,49 +623,12 @@ asmlinkage long sys_inotify_add_watch(in
 	inode = nd.dentry->d_inode;
 	dev = filp->private_data;
 
-	mutex_lock(&inode->inotify_mutex);
-	mutex_lock(&dev->mutex);
-
-	if (mask & IN_MASK_ADD)
-		mask_add = 1;
+	mutex_lock(&dev->up_mutex);
+	ret = inotify_find_update_watch(dev->ih, inode, mask);
+	if (ret == -ENOENT)
+		ret = create_watch(dev, inode, mask);
+	mutex_unlock(&dev->up_mutex);
 
-	/* don't let user-space set invalid bits: we don't want flags set */
-	mask &= IN_ALL_EVENTS | IN_ONESHOT;
-	if (unlikely(!mask)) {
-		ret = -EINVAL;
-		goto out;
-	}
-
-	/*
-	 * Handle the case of re-adding a watch on an (inode,dev) pair that we
-	 * are already watching.  We just update the mask and return its wd.
-	 */
-	old = inode_find_dev(inode, dev);
-	if (unlikely(old)) {
-		if (mask_add)
-			old->mask |= mask;
-		else
-			old->mask = mask;
-		ret = old->wd;
-		goto out;
-	}
-
-	watch = create_watch(dev, mask, inode);
-	if (unlikely(IS_ERR(watch))) {
-		ret = PTR_ERR(watch);
-		goto out;
-	}
-
-	if (!inotify_inode_watched(inode))
-		set_dentry_child_flags(inode, 1);
-
-	/* Add the watch to the device's and the inode's list */
-	list_add(&watch->d_list, &dev->watches);
-	list_add(&watch->i_list, &inode->inotify_watches);
-	ret = watch->wd;
-out:
-	mutex_unlock(&dev->mutex);
-	mutex_unlock(&inode->inotify_mutex);
 	path_release(&nd);
 fput_and_out:
 	fput_light(filp, fput_needed);
@@ -1091,7 +652,9 @@ asmlinkage long sys_inotify_rm_watch(int
 	}
 
 	dev = filp->private_data;
-	ret = inotify_ignore(dev, wd);
+
+	/* we free our watch data when we get IN_IGNORED */
+	ret = inotify_rm_wd(dev->ih, wd);
 
 out:
 	fput_light(filp, fput_needed);
@@ -1112,11 +675,11 @@ static struct file_system_type inotify_f
 };
 
 /*
- * inotify_setup - Our initialization function.  Note that we cannnot return
+ * inotify_user_setup - Our initialization function.  Note that we cannnot return
  * error because we have compiled-in VFS hooks.  So an (unlikely) failure here
  * must result in panic().
  */
-static int __init inotify_setup(void)
+static int __init inotify_user_setup(void)
 {
 	int ret;
 
@@ -1132,10 +695,8 @@ static int __init inotify_setup(void)
 	inotify_max_user_instances = 128;
 	inotify_max_user_watches = 8192;
 
-	atomic_set(&inotify_cookie, 0);
-
 	watch_cachep = kmem_cache_create("inotify_watch_cache",
-					 sizeof(struct inotify_watch),
+					 sizeof(struct inotify_user_watch),
 					 0, SLAB_PANIC, NULL, NULL);
 	event_cachep = kmem_cache_create("inotify_event_cache",
 					 sizeof(struct inotify_kernel_event),
@@ -1144,4 +705,4 @@ static int __init inotify_setup(void)
 	return 0;
 }
 
-module_init(inotify_setup);
+module_init(inotify_user_setup);