From: Miklos Szeredi <miklos@szeredi.hu>
Date: Mon, 16 Jan 2006 17:52:24 +0000 (+0000)
Subject: fix
X-Git-Tag: fuse_2_6_0_pre1~24
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=15af1b81cfcc81b9f25d4155d191c071e35dabac;p=qemu-gpiodev%2Flibfuse.git

fix
---

diff --git a/ChangeLog b/ChangeLog
index 8b76422..efd5a3e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,17 @@
+2006-01-16  Miklos Szeredi <miklos@szeredi.hu>
+
+	* Added (again) asynchronous readpages support
+
+	* Each connection now shows up under /sys/fs/fuse/connections
+
+	* Connection attributes exported to sysfs: 'waiting' number of
+	waiting requests; 'abort' abort the connection
+
+	* Connection may be aborted through either the sysfs interface or
+	with 'umount -f mountpoint'
+
+	* 
+
 2006-01-14  Miklos Szeredi <miklos@szeredi.hu>
 
 	* Released 2.5.0
@@ -12,7 +26,7 @@
 
 	* Clearing ->connected or ->mounted connection flags could race
 	with setting other bitfields not protected with a lock
-	
+
 2006-01-10  Miklos Szeredi <miklos@szeredi.hu>
 
 	* kernel: add necessary compile flags for 2.4.X/x86_64.
diff --git a/doc/kernel.txt b/doc/kernel.txt
index 6b5741e..33f7431 100644
--- a/doc/kernel.txt
+++ b/doc/kernel.txt
@@ -86,6 +86,62 @@ Mount options
   The default is infinite.  Note that the size of read requests is
   limited anyway to 32 pages (which is 128kbyte on i386).
 
+Sysfs
+~~~~~
+
+FUSE sets up the following hierarchy in sysfs:
+
+  /sys/fs/fuse/connections/N/
+
+where N is an increasing number allocated to each new connection.
+
+For each connection the following attributes are defined:
+
+ 'waiting'
+
+  The number of requests which are waiting to be transfered to
+  userspace or being processed by the filesystem daemon.  If there is
+  no filesystem activity and 'waiting' is non-zero, then the
+  filesystem is hung or deadlocked.
+
+ 'abort'
+
+  Writing anything into this file will abort the filesystem
+  connection.  This means that all waiting requests will be aborted an
+  error returned for all aborted and new requests.
+
+Only a privileged user may read or write these attributes.
+
+Aborting a filesystem connection
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+It is possible to get into certain situations where the filesystem is
+not responding.  Reasons for this may be:
+
+  a) Broken userspace filesystem implementation
+
+  b) Network connection down
+
+  c) Accidental deadlock
+
+  d) Malicious deadlock
+
+(For more on c) and d) see later sections)
+
+In either of these cases it may be useful to abort the connection to
+the filesystem.  There are several ways to do this:
+
+  - Kill the filesystem daemon.  Works in case of a) and b)
+
+  - Kill the filesystem daemon and all users of the filesystem.  Works
+    in all cases except some malicious deadlocks
+
+  - Use forced umount (umount -f).  Works in all cases but only if
+    filesystem is still attached (it hasn't been lazy unmounted)
+
+  - Abort filesystem through the sysfs interface.  Most powerful
+    method, always works.
+
 How do non-privileged mounts work?
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
@@ -313,3 +369,10 @@ faulted with get_user_pages().  The 'req->locked' flag indicates
 when the copy is taking place, and interruption is delayed until
 this flag is unset.
 
+Scenario 3 - Tricky deadlock with asynchronous read
+---------------------------------------------------
+
+The same situation as above, except thread-1 will wait on page lock
+and hence it will be uninterruptible as well.  The solution is to
+abort the connection with forced umount (if mount is attached) or
+through the abort attribute in sysfs.
diff --git a/kernel/configure.ac b/kernel/configure.ac
index 12d224a..0ef06f8 100644
--- a/kernel/configure.ac
+++ b/kernel/configure.ac
@@ -37,7 +37,9 @@ if test -z "$enable_kernel_module" -a -z "$kernelbuild" && echo "$runver" | grep
 	fi
 	if test "$checkmodule" = yes; then
 		AC_MSG_CHECKING([if FUSE module is from official kernel])
-			if fgrep -q "fuse distribution version: " /lib/modules/${runver}/kernel/fs/fuse/fuse.ko 2> /dev/null; then
+		if test ! -f /lib/modules/${runver}/kernel/fs/fuse/fuse.ko; then
+			AC_MSG_RESULT([no])
+		elif fgrep -q "fuse distribution version: " /lib/modules/${runver}/kernel/fs/fuse/fuse.ko 2> /dev/null; then
 			AC_MSG_RESULT([no])
 		else
 			AC_MSG_RESULT([yes])
@@ -152,6 +154,21 @@ if test "$ENABLE_FUSE_MODULE" = y; then
 	else
 		AC_MSG_RESULT([no])
 	fi
+	AC_MSG_CHECKING([if kernel defines kzalloc function])
+	if egrep -qw "kzalloc" $kernelsrc/include/linux/slab.h; then
+		AC_DEFINE(HAVE_KZALLOC, 1, [kzalloc() is defined])
+		AC_MSG_RESULT([yes])
+	else
+		AC_MSG_RESULT([no])
+	fi
+
+	AC_MSG_CHECKING([if kernel defines fs_subsys])
+	if egrep -qw "fs_subsys" $kernelsrc/include/linux/fs.h; then
+		AC_DEFINE(HAVE_FS_SUBSYS, 1, [fs_subsys is defined])
+		AC_MSG_RESULT([yes])
+	else
+		AC_MSG_RESULT([no])
+	fi
 
 	AC_MSG_CHECKING([whether lookup_instantiate_filp is defined])
 	if test -f $kernelsrc/include/linux/namei.h && egrep -q "lookup_instantiate_filp" $kernelsrc/include/linux/namei.h; then
diff --git a/kernel/dev.c b/kernel/dev.c
index 3880f13..2fc773b 100644
--- a/kernel/dev.c
+++ b/kernel/dev.c
@@ -23,18 +23,18 @@ MODULE_ALIAS_MISCDEV(FUSE_MINOR);
 
 static kmem_cache_t *fuse_req_cachep;
 
-static inline struct fuse_conn *fuse_get_conn(struct file *file)
+static struct fuse_conn *fuse_get_conn(struct file *file)
 {
 	struct fuse_conn *fc;
 	spin_lock(&fuse_lock);
 	fc = file->private_data;
-	if (fc && !fc->mounted)
+	if (fc && !fc->connected)
 		fc = NULL;
 	spin_unlock(&fuse_lock);
 	return fc;
 }
 
-static inline void fuse_request_init(struct fuse_req *req)
+static void fuse_request_init(struct fuse_req *req)
 {
 	memset(req, 0, sizeof(*req));
 	INIT_LIST_HEAD(&req->list);
@@ -56,7 +56,7 @@ void fuse_request_free(struct fuse_req *req)
 }
 
 #ifdef KERNEL_2_6
-static inline void block_sigs(sigset_t *oldset)
+static void block_sigs(sigset_t *oldset)
 {
 	sigset_t mask;
 
@@ -64,13 +64,13 @@ static inline void block_sigs(sigset_t *oldset)
 	sigprocmask(SIG_BLOCK, &mask, oldset);
 }
 
-static inline void restore_sigs(sigset_t *oldset)
+static void restore_sigs(sigset_t *oldset)
 {
 	sigprocmask(SIG_SETMASK, oldset, NULL);
 }
 #else
 #ifdef HAVE_RECALC_SIGPENDING_TSK
-static inline void block_sigs(sigset_t *oldset)
+static void block_sigs(sigset_t *oldset)
 {
 	spin_lock_irq(&current->sighand->siglock);
 	*oldset = current->blocked;
@@ -79,7 +79,7 @@ static inline void block_sigs(sigset_t *oldset)
 	spin_unlock_irq(&current->sighand->siglock);
 }
 
-static inline void restore_sigs(sigset_t *oldset)
+static void restore_sigs(sigset_t *oldset)
 {
 	spin_lock_irq(&current->sighand->siglock);
 	current->blocked = *oldset;
@@ -87,7 +87,7 @@ static inline void restore_sigs(sigset_t *oldset)
 	spin_unlock_irq(&current->sighand->siglock);
 }
 #else
-static inline void block_sigs(sigset_t *oldset)
+static void block_sigs(sigset_t *oldset)
 {
 	spin_lock_irq(&current->sigmask_lock);
 	*oldset = current->blocked;
@@ -96,7 +96,7 @@ static inline void block_sigs(sigset_t *oldset)
 	spin_unlock_irq(&current->sigmask_lock);
 }
 
-static inline void restore_sigs(sigset_t *oldset)
+static void restore_sigs(sigset_t *oldset)
 {
 	spin_lock_irq(&current->sigmask_lock);
 	current->blocked = *oldset;
@@ -149,18 +149,24 @@ struct fuse_req *fuse_get_request(struct fuse_conn *fc)
 	int intr;
 	sigset_t oldset;
 
+	atomic_inc(&fc->num_waiting);
 	block_sigs(&oldset);
 	intr = down_interruptible(&fc->outstanding_sem);
 	restore_sigs(&oldset);
-	return intr ? NULL : do_get_request(fc);
+	if (intr) {
+		atomic_dec(&fc->num_waiting);
+		return NULL;
+	}
+	return do_get_request(fc);
 }
 
 static void fuse_putback_request(struct fuse_conn *fc, struct fuse_req *req)
 {
 	spin_lock(&fuse_lock);
-	if (req->preallocated)
+	if (req->preallocated) {
+		atomic_dec(&fc->num_waiting);
 		list_add(&req->list, &fc->unused_list);
-	else
+	} else
 		fuse_request_free(req);
 
 	/* If we are in debt decrease that first */
@@ -188,40 +194,23 @@ void fuse_release_background(struct fuse_req *req)
 	spin_unlock(&fuse_lock);
 }
 
-static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
-{
-	int i;
-	struct fuse_init_out *arg = &req->misc.init_out;
-
-	if (arg->major != FUSE_KERNEL_VERSION)
-		fc->conn_error = 1;
-	else {
-		fc->minor = arg->minor;
-		fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
-	}
-
-	/* After INIT reply is received other requests can go
-	   out.  So do (FUSE_MAX_OUTSTANDING - 1) number of
-	   up()s on outstanding_sem.  The last up() is done in
-	   fuse_putback_request() */
-	for (i = 1; i < FUSE_MAX_OUTSTANDING; i++)
-		up(&fc->outstanding_sem);
-}
-
 /*
  * This function is called when a request is finished.  Either a reply
  * has arrived or it was interrupted (and not yet sent) or some error
- * occurred during communication with userspace, or the device file was
- * closed.  It decreases the reference count for the request.  In case
- * of a background request the reference to the stored objects are
- * released.  The requester thread is woken up (if still waiting), and
- * finally the request is either freed or put on the unused_list
+ * occurred during communication with userspace, or the device file
+ * was closed.  In case of a background request the reference to the
+ * stored objects are released.  The requester thread is woken up (if
+ * still waiting), the 'end' callback is called if given, else the
+ * reference to the request is released
  *
  * Called with fuse_lock, unlocks it
  */
 static void request_end(struct fuse_conn *fc, struct fuse_req *req)
 {
-	req->finished = 1;
+	void (*end) (struct fuse_conn *, struct fuse_req *) = req->end;
+	req->end = NULL;
+	list_del(&req->list);
+	req->state = FUSE_REQ_FINISHED;
 	spin_unlock(&fuse_lock);
 	if (req->background) {
 		down_read(&fc->sbput_sem);
@@ -230,16 +219,10 @@ static void request_end(struct fuse_conn *fc, struct fuse_req *req)
 		up_read(&fc->sbput_sem);
 	}
 	wake_up(&req->waitq);
-	if (req->in.h.opcode == FUSE_INIT)
-		process_init_reply(fc, req);
-	else if (req->in.h.opcode == FUSE_RELEASE && req->inode == NULL) {
-		/* Special case for failed iget in CREATE */
-		u64 nodeid = req->in.h.nodeid;
-		fuse_reset_request(req);
-		fuse_send_forget(fc, req, nodeid, 1);
-		return;
-	}
-	fuse_put_request(fc, req);
+	if (end)
+		end(fc, req);
+	else
+		fuse_put_request(fc, req);
 }
 
 /*
@@ -290,14 +273,16 @@ static void request_wait_answer(struct fuse_conn *fc, struct fuse_req *req)
 
 	spin_unlock(&fuse_lock);
 	block_sigs(&oldset);
-	wait_event_interruptible(req->waitq, req->finished);
+	wait_event_interruptible(req->waitq, req->state == FUSE_REQ_FINISHED);
 	restore_sigs(&oldset);
 	spin_lock(&fuse_lock);
-	if (req->finished)
+	if (req->state == FUSE_REQ_FINISHED && !req->interrupted)
 		return;
 
-	req->out.h.error = -EINTR;
-	req->interrupted = 1;
+	if (!req->interrupted) {
+		req->out.h.error = -EINTR;
+		req->interrupted = 1;
+	}
 	if (req->locked) {
 		/* This is uninterruptible sleep, because data is
 		   being copied to/from the buffers of req.  During
@@ -308,10 +293,10 @@ static void request_wait_answer(struct fuse_conn *fc, struct fuse_req *req)
 		wait_event(req->waitq, !req->locked);
 		spin_lock(&fuse_lock);
 	}
-	if (!req->sent && !list_empty(&req->list)) {
+	if (req->state == FUSE_REQ_PENDING) {
 		list_del(&req->list);
 		__fuse_put_request(req);
-	} else if (!req->finished && req->sent)
+	} else if (req->state == FUSE_REQ_SENT)
 		background_request(fc, req);
 }
 
@@ -346,6 +331,7 @@ static void queue_request(struct fuse_conn *fc, struct fuse_req *req)
 			fc->outstanding_debt++;
 	}
 	list_add_tail(&req->list, &fc->pending);
+	req->state = FUSE_REQ_PENDING;
 	wake_up(&fc->waitq);
 }
 
@@ -398,34 +384,12 @@ void request_send_background(struct fuse_conn *fc, struct fuse_req *req)
 	request_send_nowait(fc, req);
 }
 
-void fuse_send_init(struct fuse_conn *fc)
-{
-	/* This is called from fuse_read_super() so there's guaranteed
-	   to be a request available */
-	struct fuse_req *req = do_get_request(fc);
-	struct fuse_init_in *arg = &req->misc.init_in;
-	arg->major = FUSE_KERNEL_VERSION;
-	arg->minor = FUSE_KERNEL_MINOR_VERSION;
-	req->in.h.opcode = FUSE_INIT;
-	req->in.numargs = 1;
-	req->in.args[0].size = sizeof(*arg);
-	req->in.args[0].value = arg;
-	req->out.numargs = 1;
-	/* Variable length arguement used for backward compatibility
-	   with interface version < 7.5.  Rest of init_out is zeroed
-	   by do_get_request(), so a short reply is not a problem */
-	req->out.argvar = 1;
-	req->out.args[0].size = sizeof(struct fuse_init_out);
-	req->out.args[0].value = &req->misc.init_out;
-	request_send_background(fc, req);
-}
-
 /*
  * Lock the request.  Up to the next unlock_request() there mustn't be
  * anything that could cause a page-fault.  If the request was already
  * interrupted bail out.
  */
-static inline int lock_request(struct fuse_req *req)
+static int lock_request(struct fuse_req *req)
 {
 	int err = 0;
 	if (req) {
@@ -444,7 +408,7 @@ static inline int lock_request(struct fuse_req *req)
  * requester thread is currently waiting for it to be unlocked, so
  * wake it up.
  */
-static inline void unlock_request(struct fuse_req *req)
+static void unlock_request(struct fuse_req *req)
 {
 	if (req) {
 		spin_lock(&fuse_lock);
@@ -480,7 +444,7 @@ static void fuse_copy_init(struct fuse_copy_state *cs, int write,
 }
 
 /* Unmap and put previous page of userspace buffer */
-static inline void fuse_copy_finish(struct fuse_copy_state *cs)
+static void fuse_copy_finish(struct fuse_copy_state *cs)
 {
 	if (cs->mapaddr) {
 		kunmap_atomic(cs->mapaddr, KM_USER0);
@@ -529,8 +493,7 @@ static int fuse_copy_fill(struct fuse_copy_state *cs)
 }
 
 /* Do as much copy to/from userspace buffer as we can */
-static inline int fuse_copy_do(struct fuse_copy_state *cs, void **val,
-			       unsigned *size)
+static int fuse_copy_do(struct fuse_copy_state *cs, void **val, unsigned *size)
 {
 	unsigned ncpy = min(*size, cs->len);
 	if (val) {
@@ -550,8 +513,8 @@ static inline int fuse_copy_do(struct fuse_copy_state *cs, void **val,
  * Copy a page in the request to/from the userspace buffer.  Must be
  * done atomically
  */
-static inline int fuse_copy_page(struct fuse_copy_state *cs, struct page *page,
-				 unsigned offset, unsigned count, int zeroing)
+static int fuse_copy_page(struct fuse_copy_state *cs, struct page *page,
+			  unsigned offset, unsigned count, int zeroing)
 {
 	if (page && zeroing && count < PAGE_SIZE) {
 		void *mapaddr = kmap_atomic(page, KM_USER1);
@@ -633,7 +596,7 @@ static void request_wait(struct fuse_conn *fc)
 	DECLARE_WAITQUEUE(wait, current);
 
 	add_wait_queue_exclusive(&fc->waitq, &wait);
-	while (fc->mounted && list_empty(&fc->pending)) {
+	while (fc->connected && list_empty(&fc->pending)) {
 		set_current_state(TASK_INTERRUPTIBLE);
 		if (signal_pending(current))
 			break;
@@ -647,7 +610,7 @@ static void request_wait(struct fuse_conn *fc)
 }
 
 #ifndef KERNEL_2_6
-static inline size_t iov_length(const struct iovec *iov, unsigned long nr_segs)
+static size_t iov_length(const struct iovec *iov, unsigned long nr_segs)
 {
 	unsigned long seg;
 	size_t ret = 0;
@@ -684,14 +647,15 @@ static ssize_t fuse_dev_readv(struct file *file, const struct iovec *iov,
 		goto err_unlock;
 	request_wait(fc);
 	err = -ENODEV;
-	if (!fc->mounted)
+	if (!fc->connected)
 		goto err_unlock;
 	err = -ERESTARTSYS;
 	if (list_empty(&fc->pending))
 		goto err_unlock;
 
 	req = list_entry(fc->pending.next, struct fuse_req, list);
-	list_del_init(&req->list);
+	req->state = FUSE_REQ_READING;
+	list_move(&req->list, &fc->io);
 
 	in = &req->in;
 	reqsize = in->h.len;
@@ -724,8 +688,8 @@ static ssize_t fuse_dev_readv(struct file *file, const struct iovec *iov,
 	if (!req->isreply)
 		request_end(fc, req);
 	else {
-		req->sent = 1;
-		list_add_tail(&req->list, &fc->processing);
+		req->state = FUSE_REQ_SENT;
+		list_move_tail(&req->list, &fc->processing);
 		spin_unlock(&fuse_lock);
 	}
 	return reqsize;
@@ -813,12 +777,15 @@ static ssize_t fuse_dev_writev(struct file *file, const struct iovec *iov,
 		goto err_finish;
 
 	spin_lock(&fuse_lock);
+	err = -ENOENT;
+	if (!fc->connected)
+		goto err_unlock;
+
 	req = request_find(fc, oh.unique);
 	err = -EINVAL;
 	if (!req)
 		goto err_unlock;
 
-	list_del_init(&req->list);
 	if (req->interrupted) {
 		spin_unlock(&fuse_lock);
 		fuse_copy_finish(&cs);
@@ -826,6 +793,7 @@ static ssize_t fuse_dev_writev(struct file *file, const struct iovec *iov,
 		request_end(fc, req);
 		return -ENOENT;
 	}
+	list_move(&req->list, &fc->io);
 	req->out.h = oh;
 	req->locked = 1;
 	cs.req = req;
@@ -879,19 +847,90 @@ static unsigned fuse_dev_poll(struct file *file, poll_table *wait)
 	return mask;
 }
 
-/* Abort all requests on the given list (pending or processing) */
+/*
+ * Abort all requests on the given list (pending or processing)
+ *
+ * This function releases and reacquires fuse_lock
+ */
 static void end_requests(struct fuse_conn *fc, struct list_head *head)
 {
 	while (!list_empty(head)) {
 		struct fuse_req *req;
 		req = list_entry(head->next, struct fuse_req, list);
-		list_del_init(&req->list);
 		req->out.h.error = -ECONNABORTED;
 		request_end(fc, req);
 		spin_lock(&fuse_lock);
 	}
 }
 
+/*
+ * Abort requests under I/O
+ *
+ * The requests are set to interrupted and finished, and the request
+ * waiter is woken up.  This will make request_wait_answer() wait
+ * until the request is unlocked and then return.
+ *
+ * If the request is asynchronous, then the end function needs to be
+ * called after waiting for the request to be unlocked (if it was
+ * locked).
+ */
+static void end_io_requests(struct fuse_conn *fc)
+{
+	while (!list_empty(&fc->io)) {
+		struct fuse_req *req =
+			list_entry(fc->io.next, struct fuse_req, list);
+		void (*end) (struct fuse_conn *, struct fuse_req *) = req->end;
+
+		req->interrupted = 1;
+		req->out.h.error = -ECONNABORTED;
+		req->state = FUSE_REQ_FINISHED;
+		list_del_init(&req->list);
+		wake_up(&req->waitq);
+		if (end) {
+			req->end = NULL;
+			/* The end function will consume this reference */
+			__fuse_get_request(req);
+			spin_unlock(&fuse_lock);
+			wait_event(req->waitq, !req->locked);
+			end(fc, req);
+			spin_lock(&fuse_lock);
+		}
+	}
+}
+
+/*
+ * Abort all requests.
+ *
+ * Emergency exit in case of a malicious or accidental deadlock, or
+ * just a hung filesystem.
+ *
+ * The same effect is usually achievable through killing the
+ * filesystem daemon and all users of the filesystem.  The exception
+ * is the combination of an asynchronous request and the tricky
+ * deadlock (see Documentation/filesystems/fuse.txt).
+ *
+ * During the aborting, progression of requests from the pending and
+ * processing lists onto the io list, and progression of new requests
+ * onto the pending list is prevented by req->connected being false.
+ *
+ * Progression of requests under I/O to the processing list is
+ * prevented by the req->interrupted flag being true for these
+ * requests.  For this reason requests on the io list must be aborted
+ * first.
+ */
+void fuse_abort_conn(struct fuse_conn *fc)
+{
+	spin_lock(&fuse_lock);
+	if (fc->connected) {
+		fc->connected = 0;
+		end_io_requests(fc);
+		end_requests(fc, &fc->pending);
+		end_requests(fc, &fc->processing);
+		wake_up_all(&fc->waitq);
+	}
+	spin_unlock(&fuse_lock);
+}
+
 static int fuse_dev_release(struct inode *inode, struct file *file)
 {
 	struct fuse_conn *fc;
@@ -902,9 +941,11 @@ static int fuse_dev_release(struct inode *inode, struct file *file)
 		fc->connected = 0;
 		end_requests(fc, &fc->pending);
 		end_requests(fc, &fc->processing);
-		fuse_release_conn(fc);
 	}
 	spin_unlock(&fuse_lock);
+	if (fc)
+		kobject_put(&fc->kobj);
+
 	return 0;
 }
 
diff --git a/kernel/dir.c b/kernel/dir.c
index 084946d..478f576 100644
--- a/kernel/dir.c
+++ b/kernel/dir.c
@@ -27,10 +27,9 @@
  */
 
 /*
- * Calcualte the time in jiffies until a dentry/attributes are valid
+ * Calculate the time in jiffies until a dentry/attributes are valid
  */
-static inline unsigned long time_to_jiffies(unsigned long sec,
-					    unsigned long nsec)
+static unsigned long time_to_jiffies(unsigned long sec, unsigned long nsec)
 {
 	struct timespec ts = {sec, nsec};
 	return jiffies + timespec_to_jiffies(&ts);
@@ -171,7 +170,7 @@ static int dir_alias(struct inode *inode)
 	return 0;
 }
 
-static inline int invalid_nodeid(u64 nodeid)
+static int invalid_nodeid(u64 nodeid)
 {
 	return !nodeid || nodeid == FUSE_ROOT_ID;
 }
@@ -190,7 +189,7 @@ static struct dentry_operations fuse_dentry_operations = {
 #endif
 };
 
-static inline int valid_mode(int m)
+static int valid_mode(int m)
 {
 	return S_ISREG(m) || S_ISDIR(m) || S_ISLNK(m) || S_ISCHR(m) ||
 		S_ISBLK(m) || S_ISFIFO(m) || S_ISSOCK(m);
@@ -825,13 +824,6 @@ static int parse_dirfile(char *buf, size_t nbytes, struct file *file,
 	return 0;
 }
 
-static inline size_t fuse_send_readdir(struct fuse_req *req, struct file *file,
-				       struct inode *inode, loff_t pos,
-				       size_t count)
-{
-	return fuse_send_read_common(req, file, inode, pos, count, 1);
-}
-
 static int fuse_readdir(struct file *file, void *dstbuf, filldir_t filldir)
 {
 	int err;
@@ -855,7 +847,9 @@ static int fuse_readdir(struct file *file, void *dstbuf, filldir_t filldir)
 	}
 	req->num_pages = 1;
 	req->pages[0] = page;
-	nbytes = fuse_send_readdir(req, file, inode, file->f_pos, PAGE_SIZE);
+	fuse_read_fill(req, file, inode, file->f_pos, PAGE_SIZE, FUSE_READDIR);
+	request_send(fc, req);
+	nbytes = req->out.args[0].size;
 	err = req->out.h.error;
 	fuse_put_request(fc, req);
 	if (!err)
diff --git a/kernel/file.c b/kernel/file.c
index 14c4f7c..42ab037 100644
--- a/kernel/file.c
+++ b/kernel/file.c
@@ -127,6 +127,14 @@ int fuse_open_common(struct inode *inode, struct file *file, int isdir)
 	return err;
 }
 
+/* Special case for failed iget in CREATE */
+static void fuse_release_end(struct fuse_conn *fc, struct fuse_req *req)
+{
+	u64 nodeid = req->in.h.nodeid;
+	fuse_reset_request(req);
+	fuse_send_forget(fc, req, nodeid, 1);
+}
+
 void fuse_send_release(struct fuse_conn *fc, struct fuse_file *ff,
 		       u64 nodeid, struct inode *inode, int flags, int isdir)
 {
@@ -142,6 +150,8 @@ void fuse_send_release(struct fuse_conn *fc, struct fuse_file *ff,
 	req->in.args[0].size = sizeof(struct fuse_release_in);
 	req->in.args[0].value = inarg;
 	request_send_background(fc, req);
+	if (!inode)
+		req->end = fuse_release_end;
 	kfree(ff);
 }
 
@@ -254,38 +264,35 @@ static int fuse_fsync(struct file *file, struct dentry *de, int datasync)
 	return fuse_fsync_common(file, de, datasync, 0);
 }
 
-size_t fuse_send_read_common(struct fuse_req *req, struct file *file,
-			     struct inode *inode, loff_t pos, size_t count,
-			     int isdir)
+void fuse_read_fill(struct fuse_req *req, struct file *file,
+		    struct inode *inode, loff_t pos, size_t count, int opcode)
 {
-	struct fuse_conn *fc = get_fuse_conn(inode);
 	struct fuse_file *ff = file->private_data;
-	struct fuse_read_in inarg;
+	struct fuse_read_in *inarg = &req->misc.read_in;
 
-	memset(&inarg, 0, sizeof(struct fuse_read_in));
-	inarg.fh = ff->fh;
-	inarg.offset = pos;
-	inarg.size = count;
-	req->in.h.opcode = isdir ? FUSE_READDIR : FUSE_READ;
+	inarg->fh = ff->fh;
+	inarg->offset = pos;
+	inarg->size = count;
+	req->in.h.opcode = opcode;
 	req->in.h.nodeid = get_node_id(inode);
 	req->inode = inode;
 	req->file = file;
 	req->in.numargs = 1;
 	req->in.args[0].size = sizeof(struct fuse_read_in);
-	req->in.args[0].value = &inarg;
+	req->in.args[0].value = inarg;
 	req->out.argpages = 1;
 	req->out.argvar = 1;
 	req->out.numargs = 1;
 	req->out.args[0].size = count;
-	request_send(fc, req);
-	return req->out.args[0].size;
 }
 
-static inline size_t fuse_send_read(struct fuse_req *req, struct file *file,
-				    struct inode *inode, loff_t pos,
-				    size_t count)
+static size_t fuse_send_read(struct fuse_req *req, struct file *file,
+			     struct inode *inode, loff_t pos, size_t count)
 {
-	return fuse_send_read_common(req, file, inode, pos, count, 0);
+	struct fuse_conn *fc = get_fuse_conn(inode);
+	fuse_read_fill(req, file, inode, pos, count, FUSE_READ);
+	request_send(fc, req);
+	return req->out.args[0].size;
 }
 
 static int fuse_readpage(struct file *file, struct page *page)
@@ -319,21 +326,33 @@ static int fuse_readpage(struct file *file, struct page *page)
 }
 
 #ifdef KERNEL_2_6
-static int fuse_send_readpages(struct fuse_req *req, struct file *file,
-			       struct inode *inode)
+static void fuse_readpages_end(struct fuse_conn *fc, struct fuse_req *req)
 {
-	loff_t pos = page_offset(req->pages[0]);
-	size_t count = req->num_pages << PAGE_CACHE_SHIFT;
-	unsigned i;
-	req->out.page_zeroing = 1;
-	fuse_send_read(req, file, inode, pos, count);
+	int i;
+
+	fuse_invalidate_attr(req->pages[0]->mapping->host); /* atime changed */
+
 	for (i = 0; i < req->num_pages; i++) {
 		struct page *page = req->pages[i];
 		if (!req->out.h.error)
 			SetPageUptodate(page);
+		else
+			SetPageError(page);
 		unlock_page(page);
 	}
-	return req->out.h.error;
+	fuse_put_request(fc, req);
+}
+
+static void fuse_send_readpages(struct fuse_req *req, struct file *file,
+				struct inode *inode)
+{
+	struct fuse_conn *fc = get_fuse_conn(inode);
+	loff_t pos = page_offset(req->pages[0]);
+	size_t count = req->num_pages << PAGE_CACHE_SHIFT;
+	req->out.page_zeroing = 1;
+	req->end = fuse_readpages_end;
+	fuse_read_fill(req, file, inode, pos, count, FUSE_READ);
+	request_send_background(fc, req);
 }
 
 struct fuse_readpages_data {
@@ -353,12 +372,12 @@ static int fuse_readpages_fill(void *_data, struct page *page)
 	    (req->num_pages == FUSE_MAX_PAGES_PER_REQ ||
 	     (req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_read ||
 	     req->pages[req->num_pages - 1]->index + 1 != page->index)) {
-		int err = fuse_send_readpages(req, data->file, inode);
-		if (err) {
+		fuse_send_readpages(req, data->file, inode);
+		data->req = req = fuse_get_request(fc);
+		if (!req) {
 			unlock_page(page);
-			return err;
+			return -EINTR;
 		}
-		fuse_reset_request(req);
 	}
 	req->pages[req->num_pages] = page;
 	req->num_pages ++;
@@ -383,10 +402,8 @@ static int fuse_readpages(struct file *file, struct address_space *mapping,
 		return -EINTR;
 
 	err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
-	if (!err && data.req->num_pages)
-		err = fuse_send_readpages(data.req, file, inode);
-	fuse_put_request(fc, data.req);
-	fuse_invalidate_attr(inode); /* atime changed */
+	if (!err)
+		fuse_send_readpages(data.req, file, inode);
 	return err;
 }
 #else /* KERNEL_2_6 */
@@ -725,12 +742,8 @@ static int fuse_set_page_dirty(struct page *page)
 static struct file_operations fuse_file_operations = {
 	.llseek		= generic_file_llseek,
 #ifdef KERNEL_2_6
-	.read		= do_sync_read,
-	.write		= do_sync_write,
-	.readv		= generic_file_readv,
-	.writev		= generic_file_writev,
-	.aio_read	= generic_file_aio_read,
-	.aio_write	= generic_file_aio_write,
+	.read		= generic_file_read,
+	.write		= generic_file_write,
 #else
 	.read		= fuse_file_read,
 	.write		= generic_file_write,
diff --git a/kernel/fuse_i.h b/kernel/fuse_i.h
index 84e17dc..b68b9e3 100644
--- a/kernel/fuse_i.h
+++ b/kernel/fuse_i.h
@@ -55,6 +55,7 @@
 #  endif
 #  define new_decode_dev(x) (x)
 #  define new_encode_dev(x) (x)
+#  define s_fs_info u.generic_sbp
 #endif /* KERNEL_2_6 */
 #endif /* FUSE_MAINLINE */
 #include <linux/fs.h>
@@ -86,6 +87,22 @@ static inline void set_page_dirty_lock(struct page *page)
 	set_page_dirty(page);
 	unlock_page(page);
 }
+
+struct kobject {
+	atomic_t count;
+	void (*release) (struct kobject *);
+};
+
+static inline void kobject_get(struct kobject *kobj)
+{
+	atomic_inc(&kobj->count);
+}
+
+static inline void kobject_put(struct kobject *kobj)
+{
+	if (atomic_dec_and_test(&kobj->count))
+		kobj->release(kobj);
+}
 #endif
 /** Max number of pages that can be used in a single read request */
 #define FUSE_MAX_PAGES_PER_REQ 32
@@ -171,6 +188,11 @@ struct fuse_out {
 	/** Header returned from userspace */
 	struct fuse_out_header h;
 
+	/*
+	 * The following bitfields are not changed during the request
+	 * processing
+	 */
+
 	/** Last argument is variable length (can be shorter than
 	    arg->size) */
 	unsigned argvar:1;
@@ -188,12 +210,23 @@ struct fuse_out {
 	struct fuse_arg args[3];
 };
 
+/** The request state */
+enum fuse_req_state {
+	FUSE_REQ_INIT = 0,
+	FUSE_REQ_PENDING,
+	FUSE_REQ_READING,
+	FUSE_REQ_SENT,
+	FUSE_REQ_FINISHED
+};
+
+struct fuse_conn;
+
 /**
  * A request to the client
  */
 struct fuse_req {
-	/** This can be on either unused_list, pending or processing
-	    lists in fuse_conn */
+	/** This can be on either unused_list, pending processing or
+	    io lists in fuse_conn */
 	struct list_head list;
 
 	/** Entry on the background list */
@@ -202,6 +235,12 @@ struct fuse_req {
 	/** refcount */
 	atomic_t count;
 
+	/*
+	 * The following bitfields are either set once before the
+	 * request is queued or setting/clearing them is protected by
+	 * fuse_lock
+	 */
+
 	/** True if the request has reply */
 	unsigned isreply:1;
 
@@ -217,11 +256,8 @@ struct fuse_req {
 	/** Data is being copied to/from the request */
 	unsigned locked:1;
 
-	/** Request has been sent to userspace */
-	unsigned sent:1;
-
-	/** The request is finished */
-	unsigned finished:1;
+	/** State of the request */
+	enum fuse_req_state state;
 
 	/** The request input */
 	struct fuse_in in;
@@ -238,6 +274,7 @@ struct fuse_req {
 		struct fuse_release_in release_in;
 		struct fuse_init_in init_in;
 		struct fuse_init_out init_out;
+		struct fuse_read_in read_in;
 	} misc;
 
 	/** page vector */
@@ -257,6 +294,9 @@ struct fuse_req {
 
 	/** File used in the request (or NULL) */
 	struct file *file;
+
+	/** Request completion callback */
+	void (*end)(struct fuse_conn *, struct fuse_req *);
 };
 
 /**
@@ -267,9 +307,6 @@ struct fuse_req {
  * unmounted.
  */
 struct fuse_conn {
-	/** Reference count */
-	int count;
-
 	/** The user id for this mount */
 	uid_t user_id;
 
@@ -294,6 +331,9 @@ struct fuse_conn {
 	/** The list of requests being processed */
 	struct list_head processing;
 
+	/** The list of requests under I/O */
+	struct list_head io;
+
 	/** Requests put in the background (RELEASE or any other
 	    interrupted request) */
 	struct list_head background;
@@ -317,12 +357,20 @@ struct fuse_conn {
 	/** Mount is active */
 	unsigned mounted;
 
-	/** Connection established */
+	/** Connection established, cleared on umount, connection
+	    abort and device release */
 	unsigned connected;
 
-	/** Connection failed (version mismatch) */
+	/** Connection failed (version mismatch).  Cannot race with
+	    setting other bitfields since it is only set once in INIT
+	    reply, before any other request, and never cleared */
 	unsigned conn_error : 1;
 
+	/*
+	 * The following bitfields are only for optimization purposes
+	 * and hence races in setting them will not cause malfunction
+	 */
+
 	/** Is fsync not implemented by fs? */
 	unsigned no_fsync : 1;
 
@@ -350,6 +398,9 @@ struct fuse_conn {
 	/** Is create not implemented by fs? */
 	unsigned no_create : 1;
 
+	/** The number of requests waiting for completion */
+	atomic_t num_waiting;
+
 	/** Negotiated minor version */
 	unsigned minor;
 
@@ -357,20 +408,14 @@ struct fuse_conn {
 	/** Backing dev info */
 	struct backing_dev_info bdi;
 #endif
-};
 
-static inline struct fuse_conn **get_fuse_conn_super_p(struct super_block *sb)
-{
-#ifdef KERNEL_2_6
-	return (struct fuse_conn **) &sb->s_fs_info;
-#else
-	return (struct fuse_conn **) &sb->u.generic_sbp;
-#endif
-}
+	/** kobject */
+	struct kobject kobj;
+};
 
 static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
 {
-	return *get_fuse_conn_super_p(sb);
+	return sb->s_fs_info;
 }
 
 static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
@@ -378,6 +423,11 @@ static inline struct fuse_conn *get_fuse_conn(struct inode *inode)
 	return get_fuse_conn_super(inode->i_sb);
 }
 
+static inline struct fuse_conn *get_fuse_conn_kobj(struct kobject *obj)
+{
+	return container_of(obj, struct fuse_conn, kobj);
+}
+
 static inline struct fuse_inode *get_fuse_inode(struct inode *inode)
 {
 	return container_of(inode, struct fuse_inode, inode);
@@ -419,11 +469,10 @@ void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req,
 		      unsigned long nodeid, u64 nlookup);
 
 /**
- * Send READ or READDIR request
+ * Initialize READ or READDIR request
  */
-size_t fuse_send_read_common(struct fuse_req *req, struct file *file,
-			     struct inode *inode, loff_t pos, size_t count,
-			     int isdir);
+void fuse_read_fill(struct fuse_req *req, struct file *file,
+		    struct inode *inode, loff_t pos, size_t count, int opcode);
 
 /**
  * Send OPEN or OPENDIR request
@@ -477,12 +526,6 @@ void fuse_init_symlink(struct inode *inode);
  */
 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr);
 
-/**
- * Check if the connection can be released, and if yes, then free the
- * connection structure
- */
-void fuse_release_conn(struct fuse_conn *fc);
-
 /**
  * Initialize the client device
  */
@@ -539,6 +582,9 @@ void request_send_background(struct fuse_conn *fc, struct fuse_req *req);
  */
 void fuse_release_background(struct fuse_req *req);
 
+/* Abort all requests */
+void fuse_abort_conn(struct fuse_conn *fc);
+
 /**
  * Get the attributes of a file
  */
@@ -548,8 +594,3 @@ int fuse_do_getattr(struct inode *inode);
  * Invalidate inode attributes
  */
 void fuse_invalidate_attr(struct inode *inode);
-
-/**
- * Send the INIT message
- */
-void fuse_send_init(struct fuse_conn *fc);
diff --git a/kernel/inode.c b/kernel/inode.c
index af374c8..f10990f 100644
--- a/kernel/inode.c
+++ b/kernel/inode.c
@@ -30,6 +30,15 @@ MODULE_LICENSE("GPL");
 
 spinlock_t fuse_lock;
 static kmem_cache_t *fuse_inode_cachep;
+#ifdef KERNEL_2_6
+static struct subsystem connections_subsys;
+
+struct fuse_conn_attr {
+	struct attribute attr;
+	ssize_t (*show)(struct fuse_conn *, char *);
+	ssize_t (*store)(struct fuse_conn *, const char *, size_t);
+};
+#endif
 
 #define FUSE_SUPER_MAGIC 0x65735546
 
@@ -261,6 +270,11 @@ struct inode *fuse_iget(struct super_block *sb, unsigned long nodeid,
 }
 #endif
 
+static void fuse_umount_begin(struct super_block *sb)
+{
+	fuse_abort_conn(get_fuse_conn_super(sb));
+}
+
 static void fuse_put_super(struct super_block *sb)
 {
 	struct fuse_conn *fc = get_fuse_conn_super(sb);
@@ -272,14 +286,15 @@ static void fuse_put_super(struct super_block *sb)
 
 	spin_lock(&fuse_lock);
 	fc->mounted = 0;
-	fc->user_id = 0;
-	fc->group_id = 0;
-	fc->flags = 0;
+	fc->connected = 0;
+	spin_unlock(&fuse_lock);
+	up_write(&fc->sbput_sem);
 	/* Flush all readers on this fs */
 	wake_up_all(&fc->waitq);
-	up_write(&fc->sbput_sem);
-	fuse_release_conn(fc);
-	spin_unlock(&fuse_lock);
+#ifdef KERNEL_2_6
+	kobject_del(&fc->kobj);
+#endif
+	kobject_put(&fc->kobj);
 }
 
 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
@@ -445,8 +460,10 @@ static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
 	return 0;
 }
 
-static void free_conn(struct fuse_conn *fc)
+static void fuse_conn_release(struct kobject *kobj)
 {
+	struct fuse_conn *fc = get_fuse_conn_kobj(kobj);
+
 	while (!list_empty(&fc->unused_list)) {
 		struct fuse_req *req;
 		req = list_entry(fc->unused_list.next, struct fuse_req, list);
@@ -456,33 +473,42 @@ static void free_conn(struct fuse_conn *fc)
 	kfree(fc);
 }
 
-/* Must be called with the fuse lock held */
-void fuse_release_conn(struct fuse_conn *fc)
+#ifndef HAVE_KZALLOC
+static void *kzalloc(size_t size, int flags)
 {
-	fc->count--;
-	if (!fc->count)
-		free_conn(fc);
+	void *ret = kmalloc(size, flags);
+	if (ret)
+		memset(ret, 0, size);
+	return ret;
 }
-
+#endif
 static struct fuse_conn *new_conn(void)
 {
 	struct fuse_conn *fc;
 
-	fc = kmalloc(sizeof(*fc), GFP_KERNEL);
-	if (fc != NULL) {
+	fc = kzalloc(sizeof(*fc), GFP_KERNEL);
+	if (fc) {
 		int i;
-		memset(fc, 0, sizeof(*fc));
 		init_waitqueue_head(&fc->waitq);
 		INIT_LIST_HEAD(&fc->pending);
 		INIT_LIST_HEAD(&fc->processing);
+		INIT_LIST_HEAD(&fc->io);
 		INIT_LIST_HEAD(&fc->unused_list);
 		INIT_LIST_HEAD(&fc->background);
-		sema_init(&fc->outstanding_sem, 0);
+		sema_init(&fc->outstanding_sem, 1); /* One for INIT */
 		init_rwsem(&fc->sbput_sem);
+#ifdef KERNEL_2_6
+		kobj_set_kset_s(fc, connections_subsys);
+		kobject_init(&fc->kobj);
+#else
+		atomic_set(&fc->kobj.count, 1);
+		fc->kobj.release = fuse_conn_release;
+#endif
+		atomic_set(&fc->num_waiting, 0);
 		for (i = 0; i < FUSE_MAX_OUTSTANDING; i++) {
 			struct fuse_req *req = fuse_request_alloc();
 			if (!req) {
-				free_conn(fc);
+				kobject_put(&fc->kobj);
 				return NULL;
 			}
 			list_add(&req->list, &fc->unused_list);
@@ -499,25 +525,32 @@ static struct fuse_conn *new_conn(void)
 static struct fuse_conn *get_conn(struct file *file, struct super_block *sb)
 {
 	struct fuse_conn *fc;
+	int err;
 
+	err = -EINVAL;
 	if (file->f_op != &fuse_dev_operations)
-		return ERR_PTR(-EINVAL);
+		goto out_err;
+
+	err = -ENOMEM;
 	fc = new_conn();
-	if (fc == NULL)
-		return ERR_PTR(-ENOMEM);
+	if (!fc)
+		goto out_err;
+
 	spin_lock(&fuse_lock);
-	if (file->private_data) {
-		free_conn(fc);
-		fc = ERR_PTR(-EINVAL);
-	} else {
-		file->private_data = fc;
-		*get_fuse_conn_super_p(sb) = fc;
-		fc->mounted = 1;
-		fc->connected = 1;
-		fc->count = 2;
-	}
+	err = -EINVAL;
+	if (file->private_data)
+		goto out_unlock;
+
+	kobject_get(&fc->kobj);
+	file->private_data = fc;
 	spin_unlock(&fuse_lock);
 	return fc;
+
+ out_unlock:
+	spin_unlock(&fuse_lock);
+	kobject_put(&fc->kobj);
+ out_err:
+	return ERR_PTR(err);
 }
 
 static struct inode *get_root_inode(struct super_block *sb, unsigned mode)
@@ -600,16 +633,76 @@ static struct super_operations fuse_super_operations = {
 	.read_inode	= fuse_read_inode,
 	.clear_inode	= fuse_clear_inode,
 	.put_super	= fuse_put_super,
+	.umount_begin	= fuse_umount_begin,
 	.statfs		= fuse_statfs,
 	.show_options	= fuse_show_options,
 };
 
+static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
+{
+	int i;
+	struct fuse_init_out *arg = &req->misc.init_out;
+
+	if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
+		fc->conn_error = 1;
+	else {
+		fc->minor = arg->minor;
+		fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
+	}
+
+	/* After INIT reply is received other requests can go
+	   out.  So do (FUSE_MAX_OUTSTANDING - 1) number of
+	   up()s on outstanding_sem.  The last up() is done in
+	   fuse_putback_request() */
+	for (i = 1; i < FUSE_MAX_OUTSTANDING; i++)
+		up(&fc->outstanding_sem);
+
+	fuse_put_request(fc, req);
+}
+
+static void fuse_send_init(struct fuse_conn *fc)
+{
+	/* This is called from fuse_read_super() so there's guaranteed
+	   to be exactly one request available */
+	struct fuse_req *req = fuse_get_request(fc);
+	struct fuse_init_in *arg = &req->misc.init_in;
+
+	arg->major = FUSE_KERNEL_VERSION;
+	arg->minor = FUSE_KERNEL_MINOR_VERSION;
+	req->in.h.opcode = FUSE_INIT;
+	req->in.numargs = 1;
+	req->in.args[0].size = sizeof(*arg);
+	req->in.args[0].value = arg;
+	req->out.numargs = 1;
+	/* Variable length arguement used for backward compatibility
+	   with interface version < 7.5.  Rest of init_out is zeroed
+	   by do_get_request(), so a short reply is not a problem */
+	req->out.argvar = 1;
+	req->out.args[0].size = sizeof(struct fuse_init_out);
+	req->out.args[0].value = &req->misc.init_out;
+	req->end = process_init_reply;
+	request_send_background(fc, req);
+}
+
+#ifdef KERNEL_2_6
+static unsigned long long conn_id(void)
+{
+	static unsigned long long ctr = 1;
+	unsigned long long val;
+	spin_lock(&fuse_lock);
+	val = ctr++;
+	spin_unlock(&fuse_lock);
+	return val;
+}
+#endif
+
 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
 {
 	struct fuse_conn *fc;
 	struct inode *root;
 	struct fuse_mount_data d;
 	struct file *file;
+	struct dentry *root_dentry;
 	int err;
 
 	if (!parse_fuse_opt((char *) data, &d))
@@ -644,23 +737,46 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent)
 		fc->bdi.ra_pages = fc->max_read / PAGE_CACHE_SIZE;
 #endif
 
+	/* Used by get_root_inode() */
+	sb->s_fs_info = fc;
+
 	err = -ENOMEM;
 	root = get_root_inode(sb, d.rootmode);
-	if (root == NULL)
+	if (!root)
 		goto err;
 
-	sb->s_root = d_alloc_root(root);
-	if (!sb->s_root) {
+	root_dentry = d_alloc_root(root);
+	if (!root_dentry) {
 		iput(root);
 		goto err;
 	}
+
+#ifdef KERNEL_2_6
+	err = kobject_set_name(&fc->kobj, "%llu", conn_id());
+	if (err)
+		goto err_put_root;
+
+	err = kobject_add(&fc->kobj);
+	if (err)
+		goto err_put_root;
+#endif
+
+	sb->s_root = root_dentry;
+	spin_lock(&fuse_lock);
+	fc->mounted = 1;
+	fc->connected = 1;
+	spin_unlock(&fuse_lock);
+
 	fuse_send_init(fc);
+
 	return 0;
 
+#ifdef KERNEL_2_6
+ err_put_root:
+	dput(root_dentry);
+#endif
  err:
-	spin_lock(&fuse_lock);
-	fuse_release_conn(fc);
-	spin_unlock(&fuse_lock);
+	kobject_put(&fc->kobj);
 	return err;
 }
 
@@ -692,6 +808,81 @@ static struct super_block *fuse_read_super_compat(struct super_block *sb,
 static DECLARE_FSTYPE(fuse_fs_type, "fuse", fuse_read_super_compat, 0);
 #endif
 
+#ifdef KERNEL_2_6
+static ssize_t fuse_conn_waiting_show(struct fuse_conn *fc, char *page)
+{
+	return sprintf(page, "%i\n", atomic_read(&fc->num_waiting));
+}
+
+static ssize_t fuse_conn_abort_store(struct fuse_conn *fc, const char *page,
+				     size_t count)
+{
+	fuse_abort_conn(fc);
+	return count;
+}
+
+#ifndef __ATTR
+#define __ATTR(_name,_mode,_show,_store) { \
+	.attr = {.name = __stringify(_name), .mode = _mode, .owner = THIS_MODULE },	\
+	.show	= _show,					\
+	.store	= _store,					\
+}
+#endif
+static struct fuse_conn_attr fuse_conn_waiting =
+	__ATTR(waiting, 0400, fuse_conn_waiting_show, NULL);
+static struct fuse_conn_attr fuse_conn_abort =
+	__ATTR(abort, 0600, NULL, fuse_conn_abort_store);
+
+static struct attribute *fuse_conn_attrs[] = {
+	&fuse_conn_waiting.attr,
+	&fuse_conn_abort.attr,
+	NULL,
+};
+
+static ssize_t fuse_conn_attr_show(struct kobject *kobj,
+				   struct attribute *attr,
+				   char *page)
+{
+	struct fuse_conn_attr *fca =
+		container_of(attr, struct fuse_conn_attr, attr);
+
+	if (fca->show)
+		return fca->show(get_fuse_conn_kobj(kobj), page);
+	else
+		return -EACCES;
+}
+
+static ssize_t fuse_conn_attr_store(struct kobject *kobj,
+				    struct attribute *attr,
+				    const char *page, size_t count)
+{
+	struct fuse_conn_attr *fca =
+		container_of(attr, struct fuse_conn_attr, attr);
+
+	if (fca->store)
+		return fca->store(get_fuse_conn_kobj(kobj), page, count);
+	else
+		return -EACCES;
+}
+
+static struct sysfs_ops fuse_conn_sysfs_ops = {
+	.show	= &fuse_conn_attr_show,
+	.store	= &fuse_conn_attr_store,
+};
+
+static struct kobj_type ktype_fuse_conn = {
+	.release	= fuse_conn_release,
+	.sysfs_ops	= &fuse_conn_sysfs_ops,
+	.default_attrs	= fuse_conn_attrs,
+};
+
+#ifndef HAVE_FS_SUBSYS
+static decl_subsys(fs, NULL, NULL);
+#endif
+static decl_subsys(fuse, NULL, NULL);
+static decl_subsys(connections, &ktype_fuse_conn, NULL);
+#endif /* KERNEL_2_6 */
+
 static void fuse_inode_init_once(void *foo, kmem_cache_t *cachep,
 				 unsigned long flags)
 {
@@ -729,6 +920,55 @@ static void fuse_fs_cleanup(void)
 	kmem_cache_destroy(fuse_inode_cachep);
 }
 
+#ifdef KERNEL_2_6
+static int fuse_sysfs_init(void)
+{
+	int err;
+
+#ifndef HAVE_FS_SUBSYS
+	err = subsystem_register(&fs_subsys);
+	if (err)
+		return err;
+#endif
+	kset_set_kset_s(&fuse_subsys, fs_subsys);
+	err = subsystem_register(&fuse_subsys);
+	if (err)
+		goto out_err;
+
+	kset_set_kset_s(&connections_subsys, fuse_subsys);
+	err = subsystem_register(&connections_subsys);
+	if (err)
+		goto out_fuse_unregister;
+
+	return 0;
+
+ out_fuse_unregister:
+	subsystem_unregister(&fuse_subsys);
+ out_err:
+#ifndef HAVE_FS_SUBSYS
+	subsystem_unregister(&fs_subsys);
+#endif
+	return err;
+}
+
+static void fuse_sysfs_cleanup(void)
+{
+	subsystem_unregister(&connections_subsys);
+	subsystem_unregister(&fuse_subsys);
+#ifndef HAVE_FS_SUBSYS
+	subsystem_unregister(&fs_subsys);
+#endif
+}
+#else /* KERNEL_2_6 */
+static int fuse_sysfs_init(void)
+{
+	return 0;
+}
+static void fuse_sysfs_cleanup(void)
+{
+}
+#endif /* KERNEL_2_6 */
+
 static int __init fuse_init(void)
 {
 	int res;
@@ -748,8 +988,14 @@ static int __init fuse_init(void)
 	if (res)
 		goto err_fs_cleanup;
 
+	res = fuse_sysfs_init();
+	if (res)
+		goto err_dev_cleanup;
+
 	return 0;
 
+ err_dev_cleanup:
+	fuse_dev_cleanup();
  err_fs_cleanup:
 	fuse_fs_cleanup();
  err:
@@ -760,6 +1006,7 @@ static void __exit fuse_exit(void)
 {
 	printk(KERN_DEBUG "fuse exit\n");
 
+	fuse_sysfs_cleanup();
 	fuse_fs_cleanup();
 	fuse_dev_cleanup();
 }