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authorMiklos Szeredi <mszeredi@redhat.com>2018-07-26 16:13:11 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-09-05 09:20:08 +0200
commit6465d7688c2d568054c174231fb1d01e3d408e08 (patch)
tree78be3355bb8c6089fbb7014d94f5a56e8907b173 /fs/fuse
parentc66025c1085c5983a64ac2a8ed733b8cefe1659d (diff)
fuse: umount should wait for all requests
commit b8f95e5d13f5f0191dcb4b9113113d241636e7cb upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/fuse')
-rw-r--r--fs/fuse/dev.c23
-rw-r--r--fs/fuse/fuse_i.h1
-rw-r--r--fs/fuse/inode.c2
3 files changed, 22 insertions, 4 deletions
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index d7c02ebb50cc..c94bab6103f5 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -130,6 +130,16 @@ static bool fuse_block_alloc(struct fuse_conn *fc, bool for_background)
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)
{
@@ -170,7 +180,7 @@ static struct fuse_req *__fuse_get_req(struct fuse_conn *fc, unsigned npages,
return req;
out:
- atomic_dec(&fc->num_waiting);
+ fuse_drop_waiting(fc);
return ERR_PTR(err);
}
@@ -277,7 +287,7 @@ void fuse_put_request(struct fuse_conn *fc, struct fuse_req *req)
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)
@@ -363,7 +373,7 @@ static void request_end(struct fuse_conn *fc, struct fuse_req *req)
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);
@@ -393,7 +403,7 @@ static void request_end(struct fuse_conn *fc, struct fuse_req *req)
wake_up(&req->waitq);
if (req->end)
req->end(fc, req);
-out_put_req:
+put_request:
fuse_put_request(fc, req);
}
@@ -2135,6 +2145,11 @@ void fuse_abort_conn(struct fuse_conn *fc)
}
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 e48b10c88ce7..1c905c7666de 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -854,6 +854,7 @@ void fuse_request_send_background_locked(struct fuse_conn *fc,
/* Abort all requests */
void fuse_abort_conn(struct fuse_conn *fc);
+void fuse_wait_aborted(struct fuse_conn *fc);
/**
* Invalidate inode attributes
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 0c28d8b58f2e..ce8f7f01107b 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -405,6 +405,8 @@ static void fuse_put_super(struct super_block *sb)
fuse_send_destroy(fc);
fuse_abort_conn(fc);
+ fuse_wait_aborted(fc);
+
mutex_lock(&fuse_mutex);
list_del(&fc->entry);
fuse_ctl_remove_conn(fc);