From: Ioannis Angelakopoulos <iangelak@redhat.com>
To: linux-fsdevel@vger.kernel.org, virtio-fs@redhat.com,
linux-kernel@vger.kernel.org, jack@suse.cz, amir73il@gmail.com,
viro@zeniv.linux.org.uk, miklos@szeredi.hu, vgoyal@redhat.com
Cc: Ioannis Angelakopoulos <iangelak@redhat.com>
Subject: [RFC PATCH 7/7] virtiofs: Add support for handling the remote fsnotify notifications
Date: Mon, 25 Oct 2021 16:46:34 -0400 [thread overview]
Message-ID: <20211025204634.2517-8-iangelak@redhat.com> (raw)
In-Reply-To: <20211025204634.2517-1-iangelak@redhat.com>
FUSE and specifically virtiofs should be able to handle the asynchronous
event notifications originating from the FUSE server. To this end we add
the FUSE_NOTIFY_FSNOTIFY switch case to the "virtio_fs_handle_notify" in
fs/fuse/virtio_fs.c to handle these specific notifications.
The event notification contains the information that a user space
application would receive when monitoring an inode for events. The
information is the mask of the inode watch, a file name corresponding to
the inode the remote event was generated for and finally, the inotify
cookie.
Then a new event should be generated corresponding to the event
notification received from the FUSE server. Specifically, FUSE in the guest
kernel will call the "__fsnotify" function in fs/notify/fsnotify.c to send
the event to user space.
Signed-off-by: Ioannis Angelakopoulos <iangelak@redhat.com>
---
fs/fuse/virtio_fs.c | 64 +++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 62 insertions(+), 2 deletions(-)
diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c
index d3dba9e3a07e..4c48c2812caa 100644
--- a/fs/fuse/virtio_fs.c
+++ b/fs/fuse/virtio_fs.c
@@ -16,6 +16,7 @@
#include <linux/fs_parser.h>
#include <linux/highmem.h>
#include <linux/uio.h>
+#include <linux/fsnotify_backend.h>
#include "fuse_i.h"
/* Used to help calculate the FUSE connection's max_pages limit for a request's
@@ -655,14 +656,69 @@ static void notify_node_reuse(struct virtio_fs_vq *notify_fsvq,
spin_unlock(¬ify_fsvq->lock);
}
+static int fsnotify_remote_event(struct inode *inode, uint32_t mask,
+ struct qstr *filename, uint32_t cookie)
+{
+ return __fsnotify(mask, NULL, 0, NULL,
+ (const struct qstr *)filename, inode, cookie);
+}
+
+/*
+ * Function to generate a new event when a fsnotify notification comes from the
+ * fuse server
+ */
+static int generate_fsnotify_event(struct fuse_conn *fc,
+ struct fuse_notify_fsnotify_out *fsnotify_out)
+{
+ struct inode *inode;
+ uint32_t mask, cookie;
+ struct fuse_mount *fm;
+ int ret = -1;
+ struct qstr name;
+
+ down_read(&fc->killsb);
+ inode = fuse_ilookup(fc, fsnotify_out->inode, &fm);
+ /*
+ * The inode that corresponds to the event does not exist in this case
+ * so do not generate any new event and just return an error
+ */
+ if (!inode)
+ goto out;
+
+ mask = fsnotify_out->mask;
+ cookie = fsnotify_out->cookie;
+
+ /*
+ * If the notification contained the name of the file/dir the event
+ * occurred for, it will be placed after the fsnotify_out struct in the
+ * notification message
+ */
+ if (fsnotify_out->namelen > 0) {
+ name.len = fsnotify_out->namelen;
+ name.name = (char *)fsnotify_out + sizeof(struct fuse_notify_fsnotify_out);
+ ret = fsnotify_remote_event(inode, mask, &name, cookie);
+ } else {
+ ret = fsnotify_remote_event(inode, mask, NULL, cookie);
+ }
+
+ up_read(&fc->killsb);
+out:
+ if (ret < 0)
+ return -EINVAL;
+
+ return ret;
+}
+
static int virtio_fs_handle_notify(struct virtio_fs *vfs,
- struct virtio_fs_notify_node *notifyn)
+ struct virtio_fs_notify_node *notifyn,
+ struct fuse_conn *fc)
{
int ret = 0, no_reuse = 0;
struct virtio_fs_notify *notify = ¬ifyn->notify;
struct virtio_fs_vq *notify_fsvq = &vfs->vqs[VQ_NOTIFY_IDX];
struct fuse_out_header *oh = ¬ify->out_hdr;
struct fuse_notify_lock_out *lo;
+ struct fuse_notify_fsnotify_out *fsnotify_out;
/*
* For notifications, oh.unique is 0 and oh->error contains code
@@ -673,6 +729,10 @@ static int virtio_fs_handle_notify(struct virtio_fs *vfs,
lo = (struct fuse_notify_lock_out *) ¬ify->outarg;
no_reuse = notify_complete_waiting_req(vfs, lo);
break;
+ case FUSE_NOTIFY_FSNOTIFY:
+ fsnotify_out = (struct fuse_notify_fsnotify_out *) ¬ify->outarg;
+ generate_fsnotify_event(fc, fsnotify_out);
+ break;
default:
pr_err("virtio-fs: Unexpected notification %d\n", oh->error);
}
@@ -711,7 +771,7 @@ static void virtio_fs_notify_done_work(struct work_struct *work)
WARN_ON(oh->unique);
list_del_init(¬ifyn->list);
/* Handle notification */
- virtio_fs_handle_notify(vfs, notifyn);
+ virtio_fs_handle_notify(vfs, notifyn, fsvq->fud->fc);
spin_lock(&fsvq->lock);
dec_in_flight_req(fsvq);
spin_unlock(&fsvq->lock);
--
2.33.0
next prev parent reply other threads:[~2021-10-25 20:48 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-25 20:46 [RFC PATCH 0/7] Inotify support in FUSE and virtiofs Ioannis Angelakopoulos
2021-10-25 20:46 ` [RFC PATCH 1/7] FUSE: Add the fsnotify opcode and in/out structs to FUSE Ioannis Angelakopoulos
2021-10-26 14:56 ` Amir Goldstein
2021-10-26 18:28 ` Amir Goldstein
[not found] ` <CAO17o20+jiij64y7b3eKoCjG5b_mLZj6o1LSnZ7+8exN3dFYEg@mail.gmail.com>
2021-10-27 5:46 ` Amir Goldstein
2021-10-27 21:46 ` Vivek Goyal
2021-10-28 4:13 ` Amir Goldstein
2021-10-28 14:20 ` Vivek Goyal
2021-10-25 20:46 ` [RFC PATCH 2/7] FUSE: Add the remote inotify support capability " Ioannis Angelakopoulos
2021-10-25 20:46 ` [RFC PATCH 3/7] FUSE,Inotify,Fsnotify,VFS: Add the fuse_fsnotify_update_mark inode operation Ioannis Angelakopoulos
2021-10-26 15:06 ` Amir Goldstein
2021-11-01 17:49 ` Vivek Goyal
2021-11-02 7:34 ` Amir Goldstein
2021-10-25 20:46 ` [RFC PATCH 4/7] FUSE: Add the fuse_fsnotify_send_request to FUSE Ioannis Angelakopoulos
2021-10-25 20:46 ` [RFC PATCH 5/7] Fsnotify: Add a wrapper around the fsnotify function Ioannis Angelakopoulos
2021-10-26 14:37 ` Amir Goldstein
2021-10-26 15:38 ` Vivek Goyal
2021-10-25 20:46 ` [RFC PATCH 6/7] FUSE,Fsnotify: Add the fuse_fsnotify_event inode operation Ioannis Angelakopoulos
2021-10-25 20:46 ` Ioannis Angelakopoulos [this message]
2021-10-26 15:23 ` [RFC PATCH 0/7] Inotify support in FUSE and virtiofs Amir Goldstein
2021-10-26 15:52 ` Vivek Goyal
2021-10-26 18:19 ` Amir Goldstein
2021-10-26 16:18 ` Vivek Goyal
2021-10-26 17:59 ` Amir Goldstein
2021-10-26 18:27 ` Vivek Goyal
2021-10-26 19:04 ` Amir Goldstein
[not found] ` <CAO17o20sdKAWQN6w7Oe0Ze06qcK+J=6rrmA_aWGnY__MRVDCKw@mail.gmail.com>
2021-10-27 5:59 ` Amir Goldstein
2021-10-27 13:23 ` Jan Kara
2021-10-27 20:29 ` Vivek Goyal
2021-10-27 20:37 ` Vivek Goyal
2021-11-02 11:09 ` Jan Kara
2021-11-02 12:54 ` Amir Goldstein
2021-11-02 20:34 ` Vivek Goyal
2021-11-03 7:31 ` Amir Goldstein
2021-11-03 22:29 ` Vivek Goyal
2021-11-04 5:19 ` Amir Goldstein
2021-11-03 10:09 ` Jan Kara
2021-11-03 11:17 ` Amir Goldstein
2021-11-03 22:36 ` Vivek Goyal
2021-11-04 5:29 ` Amir Goldstein
2021-11-04 10:03 ` Jan Kara
2021-11-05 14:30 ` Vivek Goyal
2021-11-10 6:28 ` Amir Goldstein
2021-11-11 17:30 ` Jan Kara
2021-11-11 20:52 ` Amir Goldstein
2021-10-27 20:24 ` Vivek Goyal
2021-10-28 5:11 ` Amir Goldstein
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