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fedora core 6 1.2949 + vserver 2.2.0
[linux-2.6.git] / fs / fuse / dev.c
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 0c9a2ee..357764d 100644 (file)
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -1,6 +1,6 @@
 /*
   FUSE: Filesystem in Userspace
 /*
   FUSE: Filesystem in Userspace
-  Copyright (C) 2001-2005  Miklos Szeredi <miklos@szeredi.hu>
+  Copyright (C) 2001-2006  Miklos Szeredi <miklos@szeredi.hu>
 
   This program can be distributed under the terms of the GNU GPL.
   See the file COPYING.
 
   This program can be distributed under the terms of the GNU GPL.
   See the file COPYING.
@@ -19,30 +19,29 @@
 
 MODULE_ALIAS_MISCDEV(FUSE_MINOR);
 
 
 MODULE_ALIAS_MISCDEV(FUSE_MINOR);
 
-static kmem_cache_t *fuse_req_cachep;
+static struct kmem_cache *fuse_req_cachep;
 
 static 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->connected)
-               fc = NULL;
-       spin_unlock(&fuse_lock);
-       return fc;
+       /*
+        * Lockless access is OK, because file->private data is set
+        * once during mount and is valid until the file is released.
+        */
+       return file->private_data;
 }
 
 static void fuse_request_init(struct fuse_req *req)
 {
        memset(req, 0, sizeof(*req));
        INIT_LIST_HEAD(&req->list);
 }
 
 static void fuse_request_init(struct fuse_req *req)
 {
        memset(req, 0, sizeof(*req));
        INIT_LIST_HEAD(&req->list);
+       INIT_LIST_HEAD(&req->intr_entry);
        init_waitqueue_head(&req->waitq);
        atomic_set(&req->count, 1);
 }
 
 struct fuse_req *fuse_request_alloc(void)
 {
        init_waitqueue_head(&req->waitq);
        atomic_set(&req->count, 1);
 }
 
 struct fuse_req *fuse_request_alloc(void)
 {
-       struct fuse_req *req = kmem_cache_alloc(fuse_req_cachep, SLAB_KERNEL);
+       struct fuse_req *req = kmem_cache_alloc(fuse_req_cachep, GFP_KERNEL);
        if (req)
                fuse_request_init(req);
        return req;
        if (req)
                fuse_request_init(req);
        return req;
@@ -66,20 +65,6 @@ static void restore_sigs(sigset_t *oldset)
        sigprocmask(SIG_SETMASK, oldset, NULL);
 }
 
        sigprocmask(SIG_SETMASK, oldset, NULL);
 }
 
-/*
- * Reset request, so that it can be reused
- *
- * The caller must be _very_ careful to make sure, that it is holding
- * the only reference to req
- */
-void fuse_reset_request(struct fuse_req *req)
-{
-       int preallocated = req->preallocated;
-       BUG_ON(atomic_read(&req->count) != 1);
-       fuse_request_init(req);
-       req->preallocated = preallocated;
-}
-
 static void __fuse_get_request(struct fuse_req *req)
 {
        atomic_inc(&req->count);
 static void __fuse_get_request(struct fuse_req *req)
 {
        atomic_inc(&req->count);
@@ -92,196 +77,242 @@ static void __fuse_put_request(struct fuse_req *req)
        atomic_dec(&req->count);
 }
 
        atomic_dec(&req->count);
 }
 
-static struct fuse_req *do_get_request(struct fuse_conn *fc)
+static void fuse_req_init_context(struct fuse_req *req)
 {
 {
-       struct fuse_req *req;
-
-       spin_lock(&fuse_lock);
-       BUG_ON(list_empty(&fc->unused_list));
-       req = list_entry(fc->unused_list.next, struct fuse_req, list);
-       list_del_init(&req->list);
-       spin_unlock(&fuse_lock);
-       fuse_request_init(req);
-       req->preallocated = 1;
        req->in.h.uid = current->fsuid;
        req->in.h.gid = current->fsgid;
        req->in.h.pid = current->pid;
        req->in.h.uid = current->fsuid;
        req->in.h.gid = current->fsgid;
        req->in.h.pid = current->pid;
-       return req;
 }
 
 }
 
-/* This can return NULL, but only in case it's interrupted by a SIGKILL */
-struct fuse_req *fuse_get_request(struct fuse_conn *fc)
+struct fuse_req *fuse_get_req(struct fuse_conn *fc)
 {
 {
-       int intr;
+       struct fuse_req *req;
        sigset_t oldset;
        sigset_t oldset;
+       int intr;
+       int err;
 
        atomic_inc(&fc->num_waiting);
        block_sigs(&oldset);
 
        atomic_inc(&fc->num_waiting);
        block_sigs(&oldset);
-       intr = down_interruptible(&fc->outstanding_sem);
+       intr = wait_event_interruptible(fc->blocked_waitq, !fc->blocked);
        restore_sigs(&oldset);
        restore_sigs(&oldset);
-       if (intr) {
-               atomic_dec(&fc->num_waiting);
-               return NULL;
-       }
-       return do_get_request(fc);
+       err = -EINTR;
+       if (intr)
+               goto out;
+
+       err = -ENOTCONN;
+       if (!fc->connected)
+               goto out;
+
+       req = fuse_request_alloc();
+       err = -ENOMEM;
+       if (!req)
+               goto out;
+
+       fuse_req_init_context(req);
+       req->waiting = 1;
+       return req;
+
+ out:
+       atomic_dec(&fc->num_waiting);
+       return ERR_PTR(err);
 }
 
 }
 
-/* Must be called with fuse_lock held */
-static void fuse_putback_request(struct fuse_conn *fc, struct fuse_req *req)
+/*
+ * Return request in fuse_file->reserved_req.  However that may
+ * currently be in use.  If that is the case, wait for it to become
+ * available.
+ */
+static struct fuse_req *get_reserved_req(struct fuse_conn *fc,
+                                        struct file *file)
 {
 {
-       if (req->preallocated) {
-               atomic_dec(&fc->num_waiting);
-               list_add(&req->list, &fc->unused_list);
-       } else
-               fuse_request_free(req);
+       struct fuse_req *req = NULL;
+       struct fuse_file *ff = file->private_data;
+
+       do {
+               wait_event(fc->blocked_waitq, ff->reserved_req);
+               spin_lock(&fc->lock);
+               if (ff->reserved_req) {
+                       req = ff->reserved_req;
+                       ff->reserved_req = NULL;
+                       get_file(file);
+                       req->stolen_file = file;
+               }
+               spin_unlock(&fc->lock);
+       } while (!req);
 
 
-       /* If we are in debt decrease that first */
-       if (fc->outstanding_debt)
-               fc->outstanding_debt--;
-       else
-               up(&fc->outstanding_sem);
+       return req;
 }
 
 }
 
-void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req)
+/*
+ * Put stolen request back into fuse_file->reserved_req
+ */
+static void put_reserved_req(struct fuse_conn *fc, struct fuse_req *req)
 {
 {
-       if (atomic_dec_and_test(&req->count)) {
-               spin_lock(&fuse_lock);
-               fuse_putback_request(fc, req);
-               spin_unlock(&fuse_lock);
-       }
+       struct file *file = req->stolen_file;
+       struct fuse_file *ff = file->private_data;
+
+       spin_lock(&fc->lock);
+       fuse_request_init(req);
+       BUG_ON(ff->reserved_req);
+       ff->reserved_req = req;
+       wake_up(&fc->blocked_waitq);
+       spin_unlock(&fc->lock);
+       fput(file);
 }
 
 }
 
-static void fuse_put_request_locked(struct fuse_conn *fc, struct fuse_req *req)
+/*
+ * Gets a requests for a file operation, always succeeds
+ *
+ * This is used for sending the FLUSH request, which must get to
+ * userspace, due to POSIX locks which may need to be unlocked.
+ *
+ * If allocation fails due to OOM, use the reserved request in
+ * fuse_file.
+ *
+ * This is very unlikely to deadlock accidentally, since the
+ * filesystem should not have it's own file open.  If deadlock is
+ * intentional, it can still be broken by "aborting" the filesystem.
+ */
+struct fuse_req *fuse_get_req_nofail(struct fuse_conn *fc, struct file *file)
 {
 {
-       if (atomic_dec_and_test(&req->count))
-               fuse_putback_request(fc, req);
+       struct fuse_req *req;
+
+       atomic_inc(&fc->num_waiting);
+       wait_event(fc->blocked_waitq, !fc->blocked);
+       req = fuse_request_alloc();
+       if (!req)
+               req = get_reserved_req(fc, file);
+
+       fuse_req_init_context(req);
+       req->waiting = 1;
+       return req;
 }
 
 }
 
-void fuse_release_background(struct fuse_req *req)
+void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req)
 {
 {
-       iput(req->inode);
-       iput(req->inode2);
-       if (req->file)
-               fput(req->file);
-       spin_lock(&fuse_lock);
-       list_del(&req->bg_entry);
-       spin_unlock(&fuse_lock);
+       if (atomic_dec_and_test(&req->count)) {
+               if (req->waiting)
+                       atomic_dec(&fc->num_waiting);
+
+               if (req->stolen_file)
+                       put_reserved_req(fc, req);
+               else
+                       fuse_request_free(req);
+       }
 }
 
 /*
  * This function is called when a request is finished.  Either a reply
 }
 
 /*
  * 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
+ * has arrived or it was aborted (and not yet sent) or some error
  * occurred during communication with userspace, or the device file
  * 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
+ * was closed.  The requester thread is woken up (if still waiting),
+ * the 'end' callback is called if given, else the reference to the
+ * request is released
  *
  *
- * Releasing extra reference for foreground requests must be done
- * within the same locked region as setting state to finished.  This
- * is because fuse_reset_request() may be called after request is
- * finished and it must be the sole possessor.  If request is
- * interrupted and put in the background, it will return with an error
- * and hence never be reset and reused.
- *
- * Called with fuse_lock, unlocks it
+ * Called with fc->lock, unlocks it
  */
 static void request_end(struct fuse_conn *fc, struct fuse_req *req)
  */
 static void request_end(struct fuse_conn *fc, struct fuse_req *req)
+       __releases(fc->lock)
 {
 {
+       void (*end) (struct fuse_conn *, struct fuse_req *) = req->end;
+       req->end = NULL;
        list_del(&req->list);
        list_del(&req->list);
+       list_del(&req->intr_entry);
        req->state = FUSE_REQ_FINISHED;
        req->state = FUSE_REQ_FINISHED;
-       if (!req->background) {
-               wake_up(&req->waitq);
-               fuse_put_request_locked(fc, req);
-               spin_unlock(&fuse_lock);
-       } else {
-               void (*end) (struct fuse_conn *, struct fuse_req *) = req->end;
-               req->end = NULL;
-               spin_unlock(&fuse_lock);
-               down_read(&fc->sbput_sem);
-               if (fc->mounted)
-                       fuse_release_background(req);
-               up_read(&fc->sbput_sem);
-               if (end)
-                       end(fc, req);
-               else
-                       fuse_put_request(fc, req);
+       if (req->background) {
+               if (fc->num_background == FUSE_MAX_BACKGROUND) {
+                       fc->blocked = 0;
+                       wake_up_all(&fc->blocked_waitq);
+               }
+               fc->num_background--;
        }
        }
+       spin_unlock(&fc->lock);
+       dput(req->dentry);
+       mntput(req->vfsmount);
+       if (req->file)
+               fput(req->file);
+       wake_up(&req->waitq);
+       if (end)
+               end(fc, req);
+       else
+               fuse_put_request(fc, req);
 }
 
 }
 
-/*
- * Unfortunately request interruption not just solves the deadlock
- * problem, it causes problems too.  These stem from the fact, that an
- * interrupted request is continued to be processed in userspace,
- * while all the locks and object references (inode and file) held
- * during the operation are released.
- *
- * To release the locks is exactly why there's a need to interrupt the
- * request, so there's not a lot that can be done about this, except
- * introduce additional locking in userspace.
- *
- * More important is to keep inode and file references until userspace
- * has replied, otherwise FORGET and RELEASE could be sent while the
- * inode/file is still used by the filesystem.
- *
- * For this reason the concept of "background" request is introduced.
- * An interrupted request is backgrounded if it has been already sent
- * to userspace.  Backgrounding involves getting an extra reference to
- * inode(s) or file used in the request, and adding the request to
- * fc->background list.  When a reply is received for a background
- * request, the object references are released, and the request is
- * removed from the list.  If the filesystem is unmounted while there
- * are still background requests, the list is walked and references
- * are released as if a reply was received.
- *
- * There's one more use for a background request.  The RELEASE message is
- * always sent as background, since it doesn't return an error or
- * data.
- */
-static void background_request(struct fuse_conn *fc, struct fuse_req *req)
-{
-       req->background = 1;
-       list_add(&req->bg_entry, &fc->background);
-       if (req->inode)
-               req->inode = igrab(req->inode);
-       if (req->inode2)
-               req->inode2 = igrab(req->inode2);
-       if (req->file)
-               get_file(req->file);
+static void wait_answer_interruptible(struct fuse_conn *fc,
+                                     struct fuse_req *req)
+{
+       if (signal_pending(current))
+               return;
+
+       spin_unlock(&fc->lock);
+       wait_event_interruptible(req->waitq, req->state == FUSE_REQ_FINISHED);
+       spin_lock(&fc->lock);
 }
 
 }
 
-/* Called with fuse_lock held.  Releases, and then reacquires it. */
+static void queue_interrupt(struct fuse_conn *fc, struct fuse_req *req)
+{
+       list_add_tail(&req->intr_entry, &fc->interrupts);
+       wake_up(&fc->waitq);
+       kill_fasync(&fc->fasync, SIGIO, POLL_IN);
+}
+
+/* Called with fc->lock held.  Releases, and then reacquires it. */
 static void request_wait_answer(struct fuse_conn *fc, struct fuse_req *req)
 {
 static void request_wait_answer(struct fuse_conn *fc, struct fuse_req *req)
 {
-       sigset_t oldset;
+       if (!fc->no_interrupt) {
+               /* Any signal may interrupt this */
+               wait_answer_interruptible(fc, req);
 
 
-       spin_unlock(&fuse_lock);
-       block_sigs(&oldset);
-       wait_event_interruptible(req->waitq, req->state == FUSE_REQ_FINISHED);
-       restore_sigs(&oldset);
-       spin_lock(&fuse_lock);
-       if (req->state == FUSE_REQ_FINISHED && !req->interrupted)
-               return;
+               if (req->aborted)
+                       goto aborted;
+               if (req->state == FUSE_REQ_FINISHED)
+                       return;
 
 
-       if (!req->interrupted) {
-               req->out.h.error = -EINTR;
                req->interrupted = 1;
                req->interrupted = 1;
+               if (req->state == FUSE_REQ_SENT)
+                       queue_interrupt(fc, req);
+       }
+
+       if (req->force) {
+               spin_unlock(&fc->lock);
+               wait_event(req->waitq, req->state == FUSE_REQ_FINISHED);
+               spin_lock(&fc->lock);
+       } else {
+               sigset_t oldset;
+
+               /* Only fatal signals may interrupt this */
+               block_sigs(&oldset);
+               wait_answer_interruptible(fc, req);
+               restore_sigs(&oldset);
        }
        }
+
+       if (req->aborted)
+               goto aborted;
+       if (req->state == FUSE_REQ_FINISHED)
+               return;
+
+       req->out.h.error = -EINTR;
+       req->aborted = 1;
+
+ aborted:
        if (req->locked) {
                /* This is uninterruptible sleep, because data is
                   being copied to/from the buffers of req.  During
                   locked state, there mustn't be any filesystem
                   operation (e.g. page fault), since that could lead
                   to deadlock */
        if (req->locked) {
                /* This is uninterruptible sleep, because data is
                   being copied to/from the buffers of req.  During
                   locked state, there mustn't be any filesystem
                   operation (e.g. page fault), since that could lead
                   to deadlock */
-               spin_unlock(&fuse_lock);
+               spin_unlock(&fc->lock);
                wait_event(req->waitq, !req->locked);
                wait_event(req->waitq, !req->locked);
-               spin_lock(&fuse_lock);
+               spin_lock(&fc->lock);
        }
        if (req->state == FUSE_REQ_PENDING) {
                list_del(&req->list);
                __fuse_put_request(req);
        }
        if (req->state == FUSE_REQ_PENDING) {
                list_del(&req->list);
                __fuse_put_request(req);
-       } else if (req->state == FUSE_REQ_SENT)
-               background_request(fc, req);
+       } else if (req->state == FUSE_REQ_SENT) {
+               spin_unlock(&fc->lock);
+               wait_event(req->waitq, req->state == FUSE_REQ_FINISHED);
+               spin_lock(&fc->lock);
+       }
 }
 
 static unsigned len_args(unsigned numargs, struct fuse_arg *args)
 }
 
 static unsigned len_args(unsigned numargs, struct fuse_arg *args)
@@ -295,37 +326,35 @@ static unsigned len_args(unsigned numargs, struct fuse_arg *args)
        return nbytes;
 }
 
        return nbytes;
 }
 
+static u64 fuse_get_unique(struct fuse_conn *fc)
+ {
+       fc->reqctr++;
+       /* zero is special */
+       if (fc->reqctr == 0)
+               fc->reqctr = 1;
+
+       return fc->reqctr;
+}
+
 static void queue_request(struct fuse_conn *fc, struct fuse_req *req)
 {
 static void queue_request(struct fuse_conn *fc, struct fuse_req *req)
 {
-       fc->reqctr++;
-       /* zero is special */
-       if (fc->reqctr == 0)
-               fc->reqctr = 1;
-       req->in.h.unique = fc->reqctr;
+       req->in.h.unique = fuse_get_unique(fc);
        req->in.h.len = sizeof(struct fuse_in_header) +
                len_args(req->in.numargs, (struct fuse_arg *) req->in.args);
        req->in.h.len = sizeof(struct fuse_in_header) +
                len_args(req->in.numargs, (struct fuse_arg *) req->in.args);
-       if (!req->preallocated) {
-               /* If request is not preallocated (either FORGET or
-                  RELEASE), then still decrease outstanding_sem, so
-                  user can't open infinite number of files while not
-                  processing the RELEASE requests.  However for
-                  efficiency do it without blocking, so if down()
-                  would block, just increase the debt instead */
-               if (down_trylock(&fc->outstanding_sem))
-                       fc->outstanding_debt++;
-       }
        list_add_tail(&req->list, &fc->pending);
        req->state = FUSE_REQ_PENDING;
        list_add_tail(&req->list, &fc->pending);
        req->state = FUSE_REQ_PENDING;
+       if (!req->waiting) {
+               req->waiting = 1;
+               atomic_inc(&fc->num_waiting);
+       }
        wake_up(&fc->waitq);
        wake_up(&fc->waitq);
+       kill_fasync(&fc->fasync, SIGIO, POLL_IN);
 }
 
 }
 
-/*
- * This can only be interrupted by a SIGKILL
- */
 void request_send(struct fuse_conn *fc, struct fuse_req *req)
 {
        req->isreply = 1;
 void request_send(struct fuse_conn *fc, struct fuse_req *req)
 {
        req->isreply = 1;
-       spin_lock(&fuse_lock);
+       spin_lock(&fc->lock);
        if (!fc->connected)
                req->out.h.error = -ENOTCONN;
        else if (fc->conn_error)
        if (!fc->connected)
                req->out.h.error = -ENOTCONN;
        else if (fc->conn_error)
@@ -338,15 +367,20 @@ void request_send(struct fuse_conn *fc, struct fuse_req *req)
 
                request_wait_answer(fc, req);
        }
 
                request_wait_answer(fc, req);
        }
-       spin_unlock(&fuse_lock);
+       spin_unlock(&fc->lock);
 }
 
 static void request_send_nowait(struct fuse_conn *fc, struct fuse_req *req)
 {
 }
 
 static void request_send_nowait(struct fuse_conn *fc, struct fuse_req *req)
 {
-       spin_lock(&fuse_lock);
+       spin_lock(&fc->lock);
        if (fc->connected) {
        if (fc->connected) {
+               req->background = 1;
+               fc->num_background++;
+               if (fc->num_background == FUSE_MAX_BACKGROUND)
+                       fc->blocked = 1;
+
                queue_request(fc, req);
                queue_request(fc, req);
-               spin_unlock(&fuse_lock);
+               spin_unlock(&fc->lock);
        } else {
                req->out.h.error = -ENOTCONN;
                request_end(fc, req);
        } else {
                req->out.h.error = -ENOTCONN;
                request_end(fc, req);
@@ -362,48 +396,46 @@ void request_send_noreply(struct fuse_conn *fc, struct fuse_req *req)
 void request_send_background(struct fuse_conn *fc, struct fuse_req *req)
 {
        req->isreply = 1;
 void request_send_background(struct fuse_conn *fc, struct fuse_req *req)
 {
        req->isreply = 1;
-       spin_lock(&fuse_lock);
-       background_request(fc, req);
-       spin_unlock(&fuse_lock);
        request_send_nowait(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
        request_send_nowait(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.
+ * aborted bail out.
  */
  */
-static int lock_request(struct fuse_req *req)
+static int lock_request(struct fuse_conn *fc, struct fuse_req *req)
 {
        int err = 0;
        if (req) {
 {
        int err = 0;
        if (req) {
-               spin_lock(&fuse_lock);
-               if (req->interrupted)
+               spin_lock(&fc->lock);
+               if (req->aborted)
                        err = -ENOENT;
                else
                        req->locked = 1;
                        err = -ENOENT;
                else
                        req->locked = 1;
-               spin_unlock(&fuse_lock);
+               spin_unlock(&fc->lock);
        }
        return err;
 }
 
 /*
        }
        return err;
 }
 
 /*
- * Unlock request.  If it was interrupted during being locked, the
+ * Unlock request.  If it was aborted during being locked, the
  * requester thread is currently waiting for it to be unlocked, so
  * wake it up.
  */
  * requester thread is currently waiting for it to be unlocked, so
  * wake it up.
  */
-static void unlock_request(struct fuse_req *req)
+static void unlock_request(struct fuse_conn *fc, struct fuse_req *req)
 {
        if (req) {
 {
        if (req) {
-               spin_lock(&fuse_lock);
+               spin_lock(&fc->lock);
                req->locked = 0;
                req->locked = 0;
-               if (req->interrupted)
+               if (req->aborted)
                        wake_up(&req->waitq);
                        wake_up(&req->waitq);
-               spin_unlock(&fuse_lock);
+               spin_unlock(&fc->lock);
        }
 }
 
 struct fuse_copy_state {
        }
 }
 
 struct fuse_copy_state {
+       struct fuse_conn *fc;
        int write;
        struct fuse_req *req;
        const struct iovec *iov;
        int write;
        struct fuse_req *req;
        const struct iovec *iov;
@@ -416,11 +448,12 @@ struct fuse_copy_state {
        unsigned len;
 };
 
        unsigned len;
 };
 
-static void fuse_copy_init(struct fuse_copy_state *cs, int write,
-                          struct fuse_req *req, const struct iovec *iov,
-                          unsigned long nr_segs)
+static void fuse_copy_init(struct fuse_copy_state *cs, struct fuse_conn *fc,
+                          int write, struct fuse_req *req,
+                          const struct iovec *iov, unsigned long nr_segs)
 {
        memset(cs, 0, sizeof(*cs));
 {
        memset(cs, 0, sizeof(*cs));
+       cs->fc = fc;
        cs->write = write;
        cs->req = req;
        cs->iov = iov;
        cs->write = write;
        cs->req = req;
        cs->iov = iov;
@@ -450,7 +483,7 @@ static int fuse_copy_fill(struct fuse_copy_state *cs)
        unsigned long offset;
        int err;
 
        unsigned long offset;
        int err;
 
-       unlock_request(cs->req);
+       unlock_request(cs->fc, cs->req);
        fuse_copy_finish(cs);
        if (!cs->seglen) {
                BUG_ON(!cs->nr_segs);
        fuse_copy_finish(cs);
        if (!cs->seglen) {
                BUG_ON(!cs->nr_segs);
@@ -473,7 +506,7 @@ static int fuse_copy_fill(struct fuse_copy_state *cs)
        cs->seglen -= cs->len;
        cs->addr += cs->len;
 
        cs->seglen -= cs->len;
        cs->addr += cs->len;
 
-       return lock_request(cs->req);
+       return lock_request(cs->fc, cs->req);
 }
 
 /* Do as much copy to/from userspace buffer as we can */
 }
 
 /* Do as much copy to/from userspace buffer as we can */
@@ -574,58 +607,113 @@ static int fuse_copy_args(struct fuse_copy_state *cs, unsigned numargs,
        return err;
 }
 
        return err;
 }
 
+static int request_pending(struct fuse_conn *fc)
+{
+       return !list_empty(&fc->pending) || !list_empty(&fc->interrupts);
+}
+
 /* Wait until a request is available on the pending list */
 static void request_wait(struct fuse_conn *fc)
 {
        DECLARE_WAITQUEUE(wait, current);
 
        add_wait_queue_exclusive(&fc->waitq, &wait);
 /* Wait until a request is available on the pending list */
 static void request_wait(struct fuse_conn *fc)
 {
        DECLARE_WAITQUEUE(wait, current);
 
        add_wait_queue_exclusive(&fc->waitq, &wait);
-       while (fc->connected && list_empty(&fc->pending)) {
+       while (fc->connected && !request_pending(fc)) {
                set_current_state(TASK_INTERRUPTIBLE);
                if (signal_pending(current))
                        break;
 
                set_current_state(TASK_INTERRUPTIBLE);
                if (signal_pending(current))
                        break;
 
-               spin_unlock(&fuse_lock);
+               spin_unlock(&fc->lock);
                schedule();
                schedule();
-               spin_lock(&fuse_lock);
+               spin_lock(&fc->lock);
        }
        set_current_state(TASK_RUNNING);
        remove_wait_queue(&fc->waitq, &wait);
 }
 
        }
        set_current_state(TASK_RUNNING);
        remove_wait_queue(&fc->waitq, &wait);
 }
 
+/*
+ * Transfer an interrupt request to userspace
+ *
+ * Unlike other requests this is assembled on demand, without a need
+ * to allocate a separate fuse_req structure.
+ *
+ * Called with fc->lock held, releases it
+ */
+static int fuse_read_interrupt(struct fuse_conn *fc, struct fuse_req *req,
+                              const struct iovec *iov, unsigned long nr_segs)
+       __releases(fc->lock)
+{
+       struct fuse_copy_state cs;
+       struct fuse_in_header ih;
+       struct fuse_interrupt_in arg;
+       unsigned reqsize = sizeof(ih) + sizeof(arg);
+       int err;
+
+       list_del_init(&req->intr_entry);
+       req->intr_unique = fuse_get_unique(fc);
+       memset(&ih, 0, sizeof(ih));
+       memset(&arg, 0, sizeof(arg));
+       ih.len = reqsize;
+       ih.opcode = FUSE_INTERRUPT;
+       ih.unique = req->intr_unique;
+       arg.unique = req->in.h.unique;
+
+       spin_unlock(&fc->lock);
+       if (iov_length(iov, nr_segs) < reqsize)
+               return -EINVAL;
+
+       fuse_copy_init(&cs, fc, 1, NULL, iov, nr_segs);
+       err = fuse_copy_one(&cs, &ih, sizeof(ih));
+       if (!err)
+               err = fuse_copy_one(&cs, &arg, sizeof(arg));
+       fuse_copy_finish(&cs);
+
+       return err ? err : reqsize;
+}
+
 /*
  * Read a single request into the userspace filesystem's buffer.  This
  * function waits until a request is available, then removes it from
  * the pending list and copies request data to userspace buffer.  If
 /*
  * Read a single request into the userspace filesystem's buffer.  This
  * function waits until a request is available, then removes it from
  * the pending list and copies request data to userspace buffer.  If
- * no reply is needed (FORGET) or request has been interrupted or
- * there was an error during the copying then it's finished by calling
+ * no reply is needed (FORGET) or request has been aborted or there
+ * was an error during the copying then it's finished by calling
  * request_end().  Otherwise add it to the processing list, and set
  * the 'sent' flag.
  */
  * request_end().  Otherwise add it to the processing list, and set
  * the 'sent' flag.
  */
-static ssize_t fuse_dev_readv(struct file *file, const struct iovec *iov,
-                             unsigned long nr_segs, loff_t *off)
+static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov,
+                             unsigned long nr_segs, loff_t pos)
 {
        int err;
 {
        int err;
-       struct fuse_conn *fc;
        struct fuse_req *req;
        struct fuse_in *in;
        struct fuse_copy_state cs;
        unsigned reqsize;
        struct fuse_req *req;
        struct fuse_in *in;
        struct fuse_copy_state cs;
        unsigned reqsize;
+       struct file *file = iocb->ki_filp;
+       struct fuse_conn *fc = fuse_get_conn(file);
+       if (!fc)
+               return -EPERM;
 
  restart:
 
  restart:
-       spin_lock(&fuse_lock);
-       fc = file->private_data;
-       err = -EPERM;
-       if (!fc)
+       spin_lock(&fc->lock);
+       err = -EAGAIN;
+       if ((file->f_flags & O_NONBLOCK) && fc->connected &&
+           !request_pending(fc))
                goto err_unlock;
                goto err_unlock;
+
        request_wait(fc);
        err = -ENODEV;
        if (!fc->connected)
                goto err_unlock;
        err = -ERESTARTSYS;
        request_wait(fc);
        err = -ENODEV;
        if (!fc->connected)
                goto err_unlock;
        err = -ERESTARTSYS;
-       if (list_empty(&fc->pending))
+       if (!request_pending(fc))
                goto err_unlock;
 
                goto err_unlock;
 
+       if (!list_empty(&fc->interrupts)) {
+               req = list_entry(fc->interrupts.next, struct fuse_req,
+                                intr_entry);
+               return fuse_read_interrupt(fc, req, iov, nr_segs);
+       }
+
        req = list_entry(fc->pending.next, struct fuse_req, list);
        req->state = FUSE_REQ_READING;
        list_move(&req->list, &fc->io);
        req = list_entry(fc->pending.next, struct fuse_req, list);
        req->state = FUSE_REQ_READING;
        list_move(&req->list, &fc->io);
@@ -641,19 +729,19 @@ static ssize_t fuse_dev_readv(struct file *file, const struct iovec *iov,
                request_end(fc, req);
                goto restart;
        }
                request_end(fc, req);
                goto restart;
        }
-       spin_unlock(&fuse_lock);
-       fuse_copy_init(&cs, 1, req, iov, nr_segs);
+       spin_unlock(&fc->lock);
+       fuse_copy_init(&cs, fc, 1, req, iov, nr_segs);
        err = fuse_copy_one(&cs, &in->h, sizeof(in->h));
        if (!err)
                err = fuse_copy_args(&cs, in->numargs, in->argpages,
                                     (struct fuse_arg *) in->args, 0);
        fuse_copy_finish(&cs);
        err = fuse_copy_one(&cs, &in->h, sizeof(in->h));
        if (!err)
                err = fuse_copy_args(&cs, in->numargs, in->argpages,
                                     (struct fuse_arg *) in->args, 0);
        fuse_copy_finish(&cs);
-       spin_lock(&fuse_lock);
+       spin_lock(&fc->lock);
        req->locked = 0;
        req->locked = 0;
-       if (!err && req->interrupted)
+       if (!err && req->aborted)
                err = -ENOENT;
        if (err) {
                err = -ENOENT;
        if (err) {
-               if (!req->interrupted)
+               if (!req->aborted)
                        req->out.h.error = -EIO;
                request_end(fc, req);
                return err;
                        req->out.h.error = -EIO;
                request_end(fc, req);
                return err;
@@ -663,24 +751,17 @@ static ssize_t fuse_dev_readv(struct file *file, const struct iovec *iov,
        else {
                req->state = FUSE_REQ_SENT;
                list_move_tail(&req->list, &fc->processing);
        else {
                req->state = FUSE_REQ_SENT;
                list_move_tail(&req->list, &fc->processing);
-               spin_unlock(&fuse_lock);
+               if (req->interrupted)
+                       queue_interrupt(fc, req);
+               spin_unlock(&fc->lock);
        }
        return reqsize;
 
  err_unlock:
        }
        return reqsize;
 
  err_unlock:
-       spin_unlock(&fuse_lock);
+       spin_unlock(&fc->lock);
        return err;
 }
 
        return err;
 }
 
-static ssize_t fuse_dev_read(struct file *file, char __user *buf,
-                            size_t nbytes, loff_t *off)
-{
-       struct iovec iov;
-       iov.iov_len = nbytes;
-       iov.iov_base = buf;
-       return fuse_dev_readv(file, &iov, 1, off);
-}
-
 /* Look up request on processing list by unique ID */
 static struct fuse_req *request_find(struct fuse_conn *fc, u64 unique)
 {
 /* Look up request on processing list by unique ID */
 static struct fuse_req *request_find(struct fuse_conn *fc, u64 unique)
 {
@@ -689,7 +770,7 @@ static struct fuse_req *request_find(struct fuse_conn *fc, u64 unique)
        list_for_each(entry, &fc->processing) {
                struct fuse_req *req;
                req = list_entry(entry, struct fuse_req, list);
        list_for_each(entry, &fc->processing) {
                struct fuse_req *req;
                req = list_entry(entry, struct fuse_req, list);
-               if (req->in.h.unique == unique)
+               if (req->in.h.unique == unique || req->intr_unique == unique)
                        return req;
        }
        return NULL;
                        return req;
        }
        return NULL;
@@ -725,19 +806,19 @@ static int copy_out_args(struct fuse_copy_state *cs, struct fuse_out *out,
  * it from the list and copy the rest of the buffer to the request.
  * The request is finished by calling request_end()
  */
  * it from the list and copy the rest of the buffer to the request.
  * The request is finished by calling request_end()
  */
-static ssize_t fuse_dev_writev(struct file *file, const struct iovec *iov,
-                              unsigned long nr_segs, loff_t *off)
+static ssize_t fuse_dev_write(struct kiocb *iocb, const struct iovec *iov,
+                              unsigned long nr_segs, loff_t pos)
 {
        int err;
        unsigned nbytes = iov_length(iov, nr_segs);
        struct fuse_req *req;
        struct fuse_out_header oh;
        struct fuse_copy_state cs;
 {
        int err;
        unsigned nbytes = iov_length(iov, nr_segs);
        struct fuse_req *req;
        struct fuse_out_header oh;
        struct fuse_copy_state cs;
-       struct fuse_conn *fc = fuse_get_conn(file);
+       struct fuse_conn *fc = fuse_get_conn(iocb->ki_filp);
        if (!fc)
        if (!fc)
-               return -ENODEV;
+               return -EPERM;
 
 
-       fuse_copy_init(&cs, 0, NULL, iov, nr_segs);
+       fuse_copy_init(&cs, fc, 0, NULL, iov, nr_segs);
        if (nbytes < sizeof(struct fuse_out_header))
                return -EINVAL;
 
        if (nbytes < sizeof(struct fuse_out_header))
                return -EINVAL;
 
@@ -749,73 +830,81 @@ static ssize_t fuse_dev_writev(struct file *file, const struct iovec *iov,
            oh.len != nbytes)
                goto err_finish;
 
            oh.len != nbytes)
                goto err_finish;
 
-       spin_lock(&fuse_lock);
+       spin_lock(&fc->lock);
        err = -ENOENT;
        if (!fc->connected)
                goto err_unlock;
 
        req = request_find(fc, oh.unique);
        err = -ENOENT;
        if (!fc->connected)
                goto err_unlock;
 
        req = request_find(fc, oh.unique);
-       err = -EINVAL;
        if (!req)
                goto err_unlock;
 
        if (!req)
                goto err_unlock;
 
-       if (req->interrupted) {
-               spin_unlock(&fuse_lock);
+       if (req->aborted) {
+               spin_unlock(&fc->lock);
                fuse_copy_finish(&cs);
                fuse_copy_finish(&cs);
-               spin_lock(&fuse_lock);
+               spin_lock(&fc->lock);
                request_end(fc, req);
                return -ENOENT;
        }
                request_end(fc, req);
                return -ENOENT;
        }
+       /* Is it an interrupt reply? */
+       if (req->intr_unique == oh.unique) {
+               err = -EINVAL;
+               if (nbytes != sizeof(struct fuse_out_header))
+                       goto err_unlock;
+
+               if (oh.error == -ENOSYS)
+                       fc->no_interrupt = 1;
+               else if (oh.error == -EAGAIN)
+                       queue_interrupt(fc, req);
+
+               spin_unlock(&fc->lock);
+               fuse_copy_finish(&cs);
+               return nbytes;
+       }
+
+       req->state = FUSE_REQ_WRITING;
        list_move(&req->list, &fc->io);
        req->out.h = oh;
        req->locked = 1;
        cs.req = req;
        list_move(&req->list, &fc->io);
        req->out.h = oh;
        req->locked = 1;
        cs.req = req;
-       spin_unlock(&fuse_lock);
+       spin_unlock(&fc->lock);
 
        err = copy_out_args(&cs, &req->out, nbytes);
        fuse_copy_finish(&cs);
 
 
        err = copy_out_args(&cs, &req->out, nbytes);
        fuse_copy_finish(&cs);
 
-       spin_lock(&fuse_lock);
+       spin_lock(&fc->lock);
        req->locked = 0;
        if (!err) {
        req->locked = 0;
        if (!err) {
-               if (req->interrupted)
+               if (req->aborted)
                        err = -ENOENT;
                        err = -ENOENT;
-       } else if (!req->interrupted)
+       } else if (!req->aborted)
                req->out.h.error = -EIO;
        request_end(fc, req);
 
        return err ? err : nbytes;
 
  err_unlock:
                req->out.h.error = -EIO;
        request_end(fc, req);
 
        return err ? err : nbytes;
 
  err_unlock:
-       spin_unlock(&fuse_lock);
+       spin_unlock(&fc->lock);
  err_finish:
        fuse_copy_finish(&cs);
        return err;
 }
 
  err_finish:
        fuse_copy_finish(&cs);
        return err;
 }
 
-static ssize_t fuse_dev_write(struct file *file, const char __user *buf,
-                             size_t nbytes, loff_t *off)
-{
-       struct iovec iov;
-       iov.iov_len = nbytes;
-       iov.iov_base = (char __user *) buf;
-       return fuse_dev_writev(file, &iov, 1, off);
-}
-
 static unsigned fuse_dev_poll(struct file *file, poll_table *wait)
 {
 static unsigned fuse_dev_poll(struct file *file, poll_table *wait)
 {
-       struct fuse_conn *fc = fuse_get_conn(file);
        unsigned mask = POLLOUT | POLLWRNORM;
        unsigned mask = POLLOUT | POLLWRNORM;
-
+       struct fuse_conn *fc = fuse_get_conn(file);
        if (!fc)
        if (!fc)
-               return -ENODEV;
+               return POLLERR;
 
        poll_wait(file, &fc->waitq, wait);
 
 
        poll_wait(file, &fc->waitq, wait);
 
-       spin_lock(&fuse_lock);
-       if (!list_empty(&fc->pending))
-                mask |= POLLIN | POLLRDNORM;
-       spin_unlock(&fuse_lock);
+       spin_lock(&fc->lock);
+       if (!fc->connected)
+               mask = POLLERR;
+       else if (request_pending(fc))
+               mask |= POLLIN | POLLRDNORM;
+       spin_unlock(&fc->lock);
 
        return mask;
 }
 
        return mask;
 }
@@ -823,7 +912,7 @@ static unsigned fuse_dev_poll(struct file *file, poll_table *wait)
 /*
  * 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
+ * This function releases and reacquires fc->lock
  */
 static void end_requests(struct fuse_conn *fc, struct list_head *head)
 {
  */
 static void end_requests(struct fuse_conn *fc, struct list_head *head)
 {
@@ -832,14 +921,14 @@ static void end_requests(struct fuse_conn *fc, struct list_head *head)
                req = list_entry(head->next, struct fuse_req, list);
                req->out.h.error = -ECONNABORTED;
                request_end(fc, req);
                req = list_entry(head->next, struct fuse_req, list);
                req->out.h.error = -ECONNABORTED;
                request_end(fc, req);
-               spin_lock(&fuse_lock);
+               spin_lock(&fc->lock);
        }
 }
 
 /*
  * Abort requests under I/O
  *
        }
 }
 
 /*
  * Abort requests under I/O
  *
- * The requests are set to interrupted and finished, and the request
+ * The requests are set to aborted and finished, and the request
  * waiter is woken up.  This will make request_wait_answer() wait
  * until the request is unlocked and then return.
  *
  * waiter is woken up.  This will make request_wait_answer() wait
  * until the request is unlocked and then return.
  *
@@ -854,7 +943,7 @@ static void end_io_requests(struct fuse_conn *fc)
                        list_entry(fc->io.next, struct fuse_req, list);
                void (*end) (struct fuse_conn *, struct fuse_req *) = req->end;
 
                        list_entry(fc->io.next, struct fuse_req, list);
                void (*end) (struct fuse_conn *, struct fuse_req *) = req->end;
 
-               req->interrupted = 1;
+               req->aborted = 1;
                req->out.h.error = -ECONNABORTED;
                req->state = FUSE_REQ_FINISHED;
                list_del_init(&req->list);
                req->out.h.error = -ECONNABORTED;
                req->state = FUSE_REQ_FINISHED;
                list_del_init(&req->list);
@@ -863,10 +952,10 @@ static void end_io_requests(struct fuse_conn *fc)
                        req->end = NULL;
                        /* The end function will consume this reference */
                        __fuse_get_request(req);
                        req->end = NULL;
                        /* The end function will consume this reference */
                        __fuse_get_request(req);
-                       spin_unlock(&fuse_lock);
+                       spin_unlock(&fc->lock);
                        wait_event(req->waitq, !req->locked);
                        end(fc, req);
                        wait_event(req->waitq, !req->locked);
                        end(fc, req);
-                       spin_lock(&fuse_lock);
+                       spin_lock(&fc->lock);
                }
        }
 }
                }
        }
 }
@@ -887,50 +976,61 @@ static void end_io_requests(struct fuse_conn *fc)
  * onto the pending list is prevented by req->connected being false.
  *
  * Progression of requests under I/O to the processing list is
  * 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.
+ * prevented by the req->aborted 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)
 {
  */
 void fuse_abort_conn(struct fuse_conn *fc)
 {
-       spin_lock(&fuse_lock);
+       spin_lock(&fc->lock);
        if (fc->connected) {
                fc->connected = 0;
        if (fc->connected) {
                fc->connected = 0;
+               fc->blocked = 0;
                end_io_requests(fc);
                end_requests(fc, &fc->pending);
                end_requests(fc, &fc->processing);
                wake_up_all(&fc->waitq);
                end_io_requests(fc);
                end_requests(fc, &fc->pending);
                end_requests(fc, &fc->processing);
                wake_up_all(&fc->waitq);
+               wake_up_all(&fc->blocked_waitq);
+               kill_fasync(&fc->fasync, SIGIO, POLL_IN);
        }
        }
-       spin_unlock(&fuse_lock);
+       spin_unlock(&fc->lock);
 }
 
 static int fuse_dev_release(struct inode *inode, struct file *file)
 {
 }
 
 static int fuse_dev_release(struct inode *inode, struct file *file)
 {
-       struct fuse_conn *fc;
-
-       spin_lock(&fuse_lock);
-       fc = file->private_data;
+       struct fuse_conn *fc = fuse_get_conn(file);
        if (fc) {
        if (fc) {
+               spin_lock(&fc->lock);
                fc->connected = 0;
                end_requests(fc, &fc->pending);
                end_requests(fc, &fc->processing);
                fc->connected = 0;
                end_requests(fc, &fc->pending);
                end_requests(fc, &fc->processing);
+               spin_unlock(&fc->lock);
+               fasync_helper(-1, file, 0, &fc->fasync);
+               fuse_conn_put(fc);
        }
        }
-       spin_unlock(&fuse_lock);
-       if (fc)
-               kobject_put(&fc->kobj);
 
        return 0;
 }
 
 
        return 0;
 }
 
-struct file_operations fuse_dev_operations = {
+static int fuse_dev_fasync(int fd, struct file *file, int on)
+{
+       struct fuse_conn *fc = fuse_get_conn(file);
+       if (!fc)
+               return -EPERM;
+
+       /* No locking - fasync_helper does its own locking */
+       return fasync_helper(fd, file, on, &fc->fasync);
+}
+
+const struct file_operations fuse_dev_operations = {
        .owner          = THIS_MODULE,
        .llseek         = no_llseek,
        .owner          = THIS_MODULE,
        .llseek         = no_llseek,
-       .read           = fuse_dev_read,
-       .readv          = fuse_dev_readv,
-       .write          = fuse_dev_write,
-       .writev         = fuse_dev_writev,
+       .read           = do_sync_read,
+       .aio_read       = fuse_dev_read,
+       .write          = do_sync_write,
+       .aio_write      = fuse_dev_write,
        .poll           = fuse_dev_poll,
        .release        = fuse_dev_release,
        .poll           = fuse_dev_poll,
        .release        = fuse_dev_release,
+       .fasync         = fuse_dev_fasync,
 };
 
 static struct miscdevice fuse_miscdevice = {
 };
 
 static struct miscdevice fuse_miscdevice = {
linux-2.6