| From b8f95e5d13f5f0191dcb4b9113113d241636e7cb Mon Sep 17 00:00:00 2001 |
| From: Miklos Szeredi <mszeredi@redhat.com> |
| Date: Thu, 26 Jul 2018 16:13:11 +0200 |
| Subject: fuse: umount should wait for all requests |
| |
| From: Miklos Szeredi <mszeredi@redhat.com> |
| |
| 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> |
| |
| --- |
| fs/fuse/dev.c | 23 +++++++++++++++++++---- |
| fs/fuse/fuse_i.h | 1 + |
| fs/fuse/inode.c | 2 ++ |
| 3 files changed, 22 insertions(+), 4 deletions(-) |
| |
| --- a/fs/fuse/dev.c |
| +++ b/fs/fuse/dev.c |
| @@ -131,6 +131,16 @@ static bool fuse_block_alloc(struct fuse |
| 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) |
| { |
| @@ -171,7 +181,7 @@ static struct fuse_req *__fuse_get_req(s |
| return req; |
| |
| out: |
| - atomic_dec(&fc->num_waiting); |
| + fuse_drop_waiting(fc); |
| return ERR_PTR(err); |
| } |
| |
| @@ -278,7 +288,7 @@ void fuse_put_request(struct fuse_conn * |
| |
| 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) |
| @@ -364,7 +374,7 @@ static void request_end(struct fuse_conn |
| 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 |
| wake_up(&req->waitq); |
| if (req->end) |
| req->end(fc, req); |
| -out_put_req: |
| +put_request: |
| fuse_put_request(fc, req); |
| } |
| |
| @@ -2141,6 +2151,11 @@ void fuse_abort_conn(struct fuse_conn *f |
| } |
| 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); |
| --- a/fs/fuse/fuse_i.h |
| +++ b/fs/fuse/fuse_i.h |
| @@ -852,6 +852,7 @@ void fuse_request_send_background_locked |
| |
| /* Abort all requests */ |
| void fuse_abort_conn(struct fuse_conn *fc); |
| +void fuse_wait_aborted(struct fuse_conn *fc); |
| |
| /** |
| * Invalidate inode attributes |
| --- a/fs/fuse/inode.c |
| +++ b/fs/fuse/inode.c |
| @@ -400,6 +400,8 @@ static void fuse_put_super(struct super_ |
| 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); |