X-Git-Url: https://git.karo-electronics.de/?a=blobdiff_plain;f=fs%2Ffuse%2Fdev.c;h=104a62dadb94c9b8fa489963b51a97bc69b3dba2;hb=edc4ff7c08e9885c40e60c4fb39fa42cc91a0602;hp=63d2cf43b5e31c5df807523713a239f2527e9cf5;hpb=d713311464bcca73c990d1a1b5c9467eae87f5b4;p=mv-sheeva.git

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 63d2cf43b5e..104a62dadb9 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -72,10 +72,8 @@ static void restore_sigs(sigset_t *oldset)
  */
 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)
@@ -90,79 +88,63 @@ static void __fuse_put_request(struct fuse_req *req)
 	atomic_dec(&req->count);
 }
 
-static struct fuse_req *do_get_request(struct fuse_conn *fc)
+struct fuse_req *fuse_get_req(struct fuse_conn *fc)
 {
 	struct fuse_req *req;
-
-	spin_lock(&fc->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(&fc->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;
-	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)
-{
-	int intr;
 	sigset_t oldset;
+	int intr;
+	int err;
 
 	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);
-	if (intr) {
-		atomic_dec(&fc->num_waiting);
-		return NULL;
-	}
-	return do_get_request(fc);
-}
+	err = -EINTR;
+	if (intr)
+		goto out;
 
-/* Must be called with fc->lock held */
-static void fuse_putback_request(struct fuse_conn *fc, struct fuse_req *req)
-{
-	if (req->preallocated) {
-		atomic_dec(&fc->num_waiting);
-		list_add(&req->list, &fc->unused_list);
-	} else
-		fuse_request_free(req);
+	req = fuse_request_alloc();
+	err = -ENOMEM;
+	if (!req)
+		goto out;
 
-	/* If we are in debt decrease that first */
-	if (fc->outstanding_debt)
-		fc->outstanding_debt--;
-	else
-		up(&fc->outstanding_sem);
+	req->in.h.uid = current->fsuid;
+	req->in.h.gid = current->fsgid;
+	req->in.h.pid = current->pid;
+	req->waiting = 1;
+	return req;
+
+ out:
+	atomic_dec(&fc->num_waiting);
+	return ERR_PTR(err);
 }
 
 void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req)
 {
 	if (atomic_dec_and_test(&req->count)) {
-		spin_lock(&fc->lock);
-		fuse_putback_request(fc, req);
-		spin_unlock(&fc->lock);
+		if (req->waiting)
+			atomic_dec(&fc->num_waiting);
+		fuse_request_free(req);
 	}
 }
 
-static void fuse_put_request_locked(struct fuse_conn *fc, struct fuse_req *req)
-{
-	if (atomic_dec_and_test(&req->count))
-		fuse_putback_request(fc, req);
-}
-
+/*
+ * Called with sbput_sem held for read (request_end) or write
+ * (fuse_put_super).  By the time fuse_put_super() is finished, all
+ * inodes belonging to background requests must be released, so the
+ * iputs have to be done within the locked region.
+ */
 void fuse_release_background(struct fuse_conn *fc, struct fuse_req *req)
 {
 	iput(req->inode);
 	iput(req->inode2);
-	if (req->file)
-		fput(req->file);
 	spin_lock(&fc->lock);
 	list_del(&req->bg_entry);
+	if (fc->num_background == FUSE_MAX_BACKGROUND) {
+		fc->blocked = 0;
+		wake_up_all(&fc->blocked_waitq);
+	}
+	fc->num_background--;
 	spin_unlock(&fc->lock);
 }
 
@@ -189,9 +171,9 @@ static void request_end(struct fuse_conn *fc, struct fuse_req *req)
 	list_del(&req->list);
 	req->state = FUSE_REQ_FINISHED;
 	if (!req->background) {
-		wake_up(&req->waitq);
-		fuse_put_request_locked(fc, req);
 		spin_unlock(&fc->lock);
+		wake_up(&req->waitq);
+		fuse_put_request(fc, req);
 	} else {
 		void (*end) (struct fuse_conn *, struct fuse_req *) = req->end;
 		req->end = NULL;
@@ -200,6 +182,11 @@ static void request_end(struct fuse_conn *fc, struct fuse_req *req)
 		if (fc->mounted)
 			fuse_release_background(fc, req);
 		up_read(&fc->sbput_sem);
+
+		/* fput must go outside sbput_sem, otherwise it can deadlock */
+		if (req->file)
+			fput(req->file);
+
 		if (end)
 			end(fc, req);
 		else
@@ -240,6 +227,9 @@ static void background_request(struct fuse_conn *fc, struct fuse_req *req)
 {
 	req->background = 1;
 	list_add(&req->bg_entry, &fc->background);
+	fc->num_background++;
+	if (fc->num_background == FUSE_MAX_BACKGROUND)
+		fc->blocked = 1;
 	if (req->inode)
 		req->inode = igrab(req->inode);
 	if (req->inode2)
@@ -302,18 +292,12 @@ static void queue_request(struct fuse_conn *fc, struct fuse_req *req)
 	req->in.h.unique = fc->reqctr;
 	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;
+	if (!req->waiting) {
+		req->waiting = 1;
+		atomic_inc(&fc->num_waiting);
+	}
 	wake_up(&fc->waitq);
 	kill_fasync(&fc->fasync, SIGIO, POLL_IN);
 }
@@ -343,6 +327,7 @@ void request_send(struct fuse_conn *fc, struct fuse_req *req)
 static void request_send_nowait(struct fuse_conn *fc, struct fuse_req *req)
 {
 	spin_lock(&fc->lock);
+	background_request(fc, req);
 	if (fc->connected) {
 		queue_request(fc, req);
 		spin_unlock(&fc->lock);
@@ -361,9 +346,6 @@ 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;
-	spin_lock(&fc->lock);
-	background_request(fc, req);
-	spin_unlock(&fc->lock);
 	request_send_nowait(fc, req);
 }
 
@@ -739,7 +721,7 @@ static ssize_t fuse_dev_writev(struct file *file, const struct iovec *iov,
 	struct fuse_copy_state cs;
 	struct fuse_conn *fc = fuse_get_conn(file);
 	if (!fc)
-		return -ENODEV;
+		return -EPERM;
 
 	fuse_copy_init(&cs, fc, 0, NULL, iov, nr_segs);
 	if (nbytes < sizeof(struct fuse_out_header))
@@ -930,7 +912,7 @@ static int fuse_dev_fasync(int fd, struct file *file, int on)
 {
 	struct fuse_conn *fc = fuse_get_conn(file);
 	if (!fc)
-		return -ENODEV;
+		return -EPERM;
 
 	/* No locking - fasync_helper does its own locking */
 	return fasync_helper(fd, file, on, &fc->fasync);