From: Vivek Goyal <vgoyal@redhat.com>
To: Liu Bo <bo.liu@linux.alibaba.com>
Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-nvdimm@lists.01.org, virtio-fs@redhat.com,
miklos@szeredi.hu, stefanha@redhat.com, dgilbert@redhat.com,
mst@redhat.com
Subject: Re: [PATCH 20/20] fuse,virtiofs: Add logic to free up a memory range
Date: Wed, 11 Mar 2020 08:59:23 -0400 [thread overview]
Message-ID: <20200311125923.GA83257@redhat.com> (raw)
In-Reply-To: <20200311051641.l6gonmmyb4o5rcrb@rsjd01523.et2sqa>
On Wed, Mar 11, 2020 at 01:16:42PM +0800, Liu Bo wrote:
[..]
> > @@ -719,6 +723,7 @@ void fuse_conn_put(struct fuse_conn *fc)
> > if (refcount_dec_and_test(&fc->count)) {
> > struct fuse_iqueue *fiq = &fc->iq;
> >
> > + flush_delayed_work(&fc->dax_free_work);
>
> Today while debugging another case, I realized that flushing work here
> at the very last fuse_conn_put() is a bit too late, here's my analysis,
>
> umount kthread
>
> deactivate_locked_super
> ->virtio_kill_sb try_to_free_dmap_chunks
> ->generic_shutdown_super ->igrab()
> ...
> ->evict_inodes() -> check all inodes' count
> ->fuse_conn_put ->iput
> ->virtio_fs_free_devs
> ->fuse_dev_free
> ->fuse_conn_put // vq1
> ->fuse_dev_free
> ->fuse_conn_put // vq2
> ->flush_delayed_work
>
> The above can end up with a warning message reported by evict_inodes()
> about stable inodes.
Hi Liu Bo,
Which warning is that? Can you point me to it in code.
> So I think it's necessary to put either
> cancel_delayed_work_sync() or flush_delayed_work() before going to
> generic_shutdown_super().
In general I agree that shutting down memory range freeing worker
earling in unmount/shutdown sequence makes sense. It does not seem
to help to let it run while filesystem is going away. How about following
patch.
---
fs/fuse/inode.c | 1 -
fs/fuse/virtio_fs.c | 5 +++++
2 files changed, 5 insertions(+), 1 deletion(-)
Index: redhat-linux/fs/fuse/virtio_fs.c
===================================================================
--- redhat-linux.orig/fs/fuse/virtio_fs.c 2020-03-10 14:11:10.970284651 -0400
+++ redhat-linux/fs/fuse/virtio_fs.c 2020-03-11 08:27:08.103330039 -0400
@@ -1295,6 +1295,11 @@ static void virtio_kill_sb(struct super_
vfs = fc->iq.priv;
fsvq = &vfs->vqs[VQ_HIPRIO];
+ /* Stop dax worker. Soon evict_inodes() will be called which will
+ * free all memory ranges belonging to all inodes.
+ */
+ flush_delayed_work(&fc->dax_free_work);
+
/* Stop forget queue. Soon destroy will be sent */
spin_lock(&fsvq->lock);
fsvq->connected = false;
Index: redhat-linux/fs/fuse/inode.c
===================================================================
--- redhat-linux.orig/fs/fuse/inode.c 2020-03-10 09:13:35.132565666 -0400
+++ redhat-linux/fs/fuse/inode.c 2020-03-11 08:22:02.685330039 -0400
@@ -723,7 +723,6 @@ void fuse_conn_put(struct fuse_conn *fc)
if (refcount_dec_and_test(&fc->count)) {
struct fuse_iqueue *fiq = &fc->iq;
- flush_delayed_work(&fc->dax_free_work);
if (fc->dax_dev)
fuse_free_dax_mem_ranges(&fc->free_ranges);
if (fiq->ops->release)
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next prev parent reply other threads:[~2020-03-11 12:59 UTC|newest]
Thread overview: 67+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-04 16:58 [PATCH 00/20] virtiofs: Add DAX support Vivek Goyal
2020-03-04 16:58 ` [PATCH 01/20] dax: Modify bdev_dax_pgoff() to handle NULL bdev Vivek Goyal
2020-03-04 16:58 ` [PATCH 02/20] dax: Create a range version of dax_layout_busy_page() Vivek Goyal
2020-03-10 15:19 ` Ira Weiny
2020-03-10 20:29 ` Vivek Goyal
2020-03-04 16:58 ` [PATCH 03/20] virtio: Add get_shm_region method Vivek Goyal
2020-03-10 10:53 ` Stefan Hajnoczi
2020-03-04 16:58 ` [PATCH 04/20] virtio: Implement get_shm_region for PCI transport Vivek Goyal
2020-03-10 11:04 ` Stefan Hajnoczi
2020-03-10 18:19 ` Vivek Goyal
2020-03-11 17:34 ` Stefan Hajnoczi
2020-03-11 19:29 ` Vivek Goyal
2020-03-10 11:12 ` Michael S. Tsirkin
2020-03-10 18:47 ` Vivek Goyal
2020-03-10 21:27 ` Michael S. Tsirkin
2020-03-04 16:58 ` [PATCH 05/20] virtio: Implement get_shm_region for MMIO transport Vivek Goyal
2020-03-10 11:06 ` Stefan Hajnoczi
2020-03-04 16:58 ` [PATCH 06/20] virtiofs: Provide a helper function for virtqueue initialization Vivek Goyal
2020-03-10 14:10 ` Miklos Szeredi
2020-03-04 16:58 ` [PATCH 07/20] fuse: Get rid of no_mount_options Vivek Goyal
2020-03-10 14:12 ` Miklos Szeredi
2020-03-04 16:58 ` [PATCH 08/20] fuse,virtiofs: Add a mount option to enable dax Vivek Goyal
2020-03-10 14:16 ` Miklos Szeredi
2020-03-04 16:58 ` [PATCH 09/20] virtio_fs, dax: Set up virtio_fs dax_device Vivek Goyal
2020-03-04 16:58 ` [PATCH 10/20] fuse,virtiofs: Keep a list of free dax memory ranges Vivek Goyal
2020-03-10 19:29 ` Miklos Szeredi
2020-03-04 16:58 ` [PATCH 11/20] fuse: implement FUSE_INIT map_alignment field Vivek Goyal
2020-03-10 19:31 ` Miklos Szeredi
2020-03-04 16:58 ` [PATCH 12/20] fuse: Introduce setupmapping/removemapping commands Vivek Goyal
2020-03-10 19:49 ` Miklos Szeredi
2020-03-10 20:33 ` Vivek Goyal
2020-03-11 7:03 ` Amir Goldstein
2020-03-11 14:19 ` Miklos Szeredi
2020-03-11 14:41 ` Vivek Goyal
2020-03-11 15:12 ` Miklos Szeredi
2020-03-04 16:58 ` [PATCH 13/20] fuse, dax: Implement dax read/write operations Vivek Goyal
2020-03-12 9:43 ` Miklos Szeredi
2020-03-12 16:02 ` Vivek Goyal
2020-03-13 10:18 ` Miklos Szeredi
2020-03-13 13:41 ` Vivek Goyal
2020-04-04 0:25 ` Liu Bo
2020-04-14 12:54 ` Vivek Goyal
2020-03-04 16:58 ` [PATCH 14/20] fuse,dax: add DAX mmap support Vivek Goyal
2020-03-04 16:58 ` [PATCH 15/20] fuse, dax: Take ->i_mmap_sem lock during dax page fault Vivek Goyal
2020-03-04 16:58 ` [PATCH 16/20] fuse,virtiofs: Define dax address space operations Vivek Goyal
2020-03-04 16:58 ` [PATCH 17/20] fuse,virtiofs: Maintain a list of busy elements Vivek Goyal
2020-03-04 16:58 ` [PATCH 18/20] fuse: Release file in process context Vivek Goyal
2020-03-04 16:58 ` [PATCH 19/20] fuse: Take inode lock for dax inode truncation Vivek Goyal
2020-03-04 16:58 ` [PATCH 20/20] fuse,virtiofs: Add logic to free up a memory range Vivek Goyal
2020-03-11 5:16 ` Liu Bo
2020-03-11 12:59 ` Vivek Goyal [this message]
2020-03-11 17:24 ` Liu Bo
2020-03-26 0:09 ` Liu Bo
2020-03-27 14:01 ` Vivek Goyal
2020-03-27 22:06 ` Liu Bo
2020-04-14 19:30 ` Vivek Goyal
2020-04-15 17:22 ` Liu Bo
2020-04-16 19:05 ` Vivek Goyal
2020-04-17 18:05 ` Liu Bo
2020-03-11 5:22 ` [PATCH 00/20] virtiofs: Add DAX support Amir Goldstein
2020-03-11 13:09 ` Vivek Goyal
2020-03-11 18:48 ` Vivek Goyal
2020-03-11 19:32 ` Amir Goldstein
2020-03-11 19:39 ` Vivek Goyal
2020-03-11 13:38 ` Patrick Ohly
2020-03-16 13:02 ` Vivek Goyal
2020-03-17 8:28 ` Patrick Ohly
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