fuse: umount should wait for all requests
fuse_abort_conn() does not guarantee that all async requests have actually
finished aborting (i.e. their ->end() function is called). This could
actually result in still used inodes after umount.
Add a helper to wait until all requests are fully done. This is done by
looking at the "num_waiting" counter. When this counter drops to zero, we
can be sure that no more requests are outstanding.
Fixes: 0d8e84b0432b ("fuse: simplify request abort")
Cc: <stable@vger.kernel.org> # v4.2
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index c8b197e..ec83b10 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -127,6 +127,16 @@
return !fc->initialized || (for_background && fc->blocked);
}
+static void fuse_drop_waiting(struct fuse_conn *fc)
+{
+ if (fc->connected) {
+ atomic_dec(&fc->num_waiting);
+ } else if (atomic_dec_and_test(&fc->num_waiting)) {
+ /* wake up aborters */
+ wake_up_all(&fc->blocked_waitq);
+ }
+}
+
static struct fuse_req *__fuse_get_req(struct fuse_conn *fc, unsigned npages,
bool for_background)
{
@@ -175,7 +185,7 @@
return req;
out:
- atomic_dec(&fc->num_waiting);
+ fuse_drop_waiting(fc);
return ERR_PTR(err);
}
@@ -285,7 +295,7 @@
if (test_bit(FR_WAITING, &req->flags)) {
__clear_bit(FR_WAITING, &req->flags);
- atomic_dec(&fc->num_waiting);
+ fuse_drop_waiting(fc);
}
if (req->stolen_file)
@@ -371,7 +381,7 @@
struct fuse_iqueue *fiq = &fc->iq;
if (test_and_set_bit(FR_FINISHED, &req->flags))
- goto out_put_req;
+ goto put_request;
spin_lock(&fiq->waitq.lock);
list_del_init(&req->intr_entry);
@@ -400,7 +410,7 @@
wake_up(&req->waitq);
if (req->end)
req->end(fc, req);
-out_put_req:
+put_request:
fuse_put_request(fc, req);
}
@@ -2143,6 +2153,11 @@
}
EXPORT_SYMBOL_GPL(fuse_abort_conn);
+void fuse_wait_aborted(struct fuse_conn *fc)
+{
+ wait_event(fc->blocked_waitq, atomic_read(&fc->num_waiting) == 0);
+}
+
int fuse_dev_release(struct inode *inode, struct file *file)
{
struct fuse_dev *fud = fuse_get_dev(file);
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 5256ad3..582b175 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -862,6 +862,7 @@
/* Abort all requests */
void fuse_abort_conn(struct fuse_conn *fc, bool is_abort);
+void fuse_wait_aborted(struct fuse_conn *fc);
/**
* Invalidate inode attributes
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index a24df88..eeab70e 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -394,6 +394,8 @@
fuse_send_destroy(fc);
fuse_abort_conn(fc, false);
+ fuse_wait_aborted(fc);
+
mutex_lock(&fuse_mutex);
list_del(&fc->entry);
fuse_ctl_remove_conn(fc);