From: Vivek Goyal <vgoyal@redhat.com>
To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
kvm@vger.kernel.org, linux-nvdimm@lists.01.org
Cc: vgoyal@redhat.com, miklos@szeredi.hu, stefanha@redhat.com,
dgilbert@redhat.com, swhiteho@redhat.com
Subject: [PATCH v2 09/30] fuse: add fuse_iqueue_ops callbacks
Date: Wed, 15 May 2019 15:26:54 -0400 [thread overview]
Message-ID: <20190515192715.18000-10-vgoyal@redhat.com> (raw)
In-Reply-To: <20190515192715.18000-1-vgoyal@redhat.com>
From: Stefan Hajnoczi <stefanha@redhat.com>
The /dev/fuse device uses fiq->waitq and fasync to signal that requests
are available. These mechanisms do not apply to virtio-fs. This patch
introduces callbacks so alternative behavior can be used.
Note that queue_interrupt() changes along these lines:
spin_lock(&fiq->waitq.lock);
wake_up_locked(&fiq->waitq);
+ kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
spin_unlock(&fiq->waitq.lock);
- kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
Since queue_request() and queue_forget() also call kill_fasync() inside
the spinlock this should be safe.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
---
fs/fuse/cuse.c | 2 +-
fs/fuse/dev.c | 50 ++++++++++++++++++++++++++++++++----------------
fs/fuse/fuse_i.h | 48 +++++++++++++++++++++++++++++++++++++++++++++-
fs/fuse/inode.c | 16 ++++++++++++----
4 files changed, 94 insertions(+), 22 deletions(-)
diff --git a/fs/fuse/cuse.c b/fs/fuse/cuse.c
index 55a26f351467..a6ed7a036b50 100644
--- a/fs/fuse/cuse.c
+++ b/fs/fuse/cuse.c
@@ -504,7 +504,7 @@ static int cuse_channel_open(struct inode *inode, struct file *file)
* Limit the cuse channel to requests that can
* be represented in file->f_cred->user_ns.
*/
- fuse_conn_init(&cc->fc, file->f_cred->user_ns);
+ fuse_conn_init(&cc->fc, file->f_cred->user_ns, &fuse_dev_fiq_ops, NULL);
fud = fuse_dev_alloc(&cc->fc);
if (!fud) {
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 42fd3b576686..ef489beadf58 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -375,13 +375,33 @@ static unsigned int fuse_req_hash(u64 unique)
return hash_long(unique & ~FUSE_INT_REQ_BIT, FUSE_PQ_HASH_BITS);
}
-static void queue_request(struct fuse_iqueue *fiq, struct fuse_req *req)
+/**
+ * A new request is available, wake fiq->waitq
+ */
+static void fuse_dev_wake_and_unlock(struct fuse_iqueue *fiq)
+__releases(fiq->waitq.lock)
{
- req->in.h.len = sizeof(struct fuse_in_header) +
- fuse_len_args(req->in.numargs, (struct fuse_arg *) req->in.args);
- list_add_tail(&req->list, &fiq->pending);
wake_up_locked(&fiq->waitq);
kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
+ spin_unlock(&fiq->waitq.lock);
+}
+
+const struct fuse_iqueue_ops fuse_dev_fiq_ops = {
+ .wake_forget_and_unlock = fuse_dev_wake_and_unlock,
+ .wake_interrupt_and_unlock = fuse_dev_wake_and_unlock,
+ .wake_pending_and_unlock = fuse_dev_wake_and_unlock,
+};
+EXPORT_SYMBOL_GPL(fuse_dev_fiq_ops);
+
+static void queue_request_and_unlock(struct fuse_iqueue *fiq,
+ struct fuse_req *req)
+__releases(fiq->waitq.lock)
+{
+ req->in.h.len = sizeof(struct fuse_in_header) +
+ fuse_len_args(req->in.numargs,
+ (struct fuse_arg *) req->in.args);
+ list_add_tail(&req->list, &fiq->pending);
+ fiq->ops->wake_pending_and_unlock(fiq);
}
void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
@@ -396,12 +416,11 @@ void fuse_queue_forget(struct fuse_conn *fc, struct fuse_forget_link *forget,
if (fiq->connected) {
fiq->forget_list_tail->next = forget;
fiq->forget_list_tail = forget;
- wake_up_locked(&fiq->waitq);
- kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
+ fiq->ops->wake_forget_and_unlock(fiq);
} else {
kfree(forget);
+ spin_unlock(&fiq->waitq.lock);
}
- spin_unlock(&fiq->waitq.lock);
}
static void flush_bg_queue(struct fuse_conn *fc)
@@ -417,8 +436,7 @@ static void flush_bg_queue(struct fuse_conn *fc)
fc->active_background++;
spin_lock(&fiq->waitq.lock);
req->in.h.unique = fuse_get_unique(fiq);
- queue_request(fiq, req);
- spin_unlock(&fiq->waitq.lock);
+ queue_request_and_unlock(fiq, req);
}
}
@@ -506,10 +524,10 @@ static int queue_interrupt(struct fuse_iqueue *fiq, struct fuse_req *req)
spin_unlock(&fiq->waitq.lock);
return 0;
}
- wake_up_locked(&fiq->waitq);
- kill_fasync(&fiq->fasync, SIGIO, POLL_IN);
+ fiq->ops->wake_interrupt_and_unlock(fiq);
+ } else {
+ spin_unlock(&fiq->waitq.lock);
}
- spin_unlock(&fiq->waitq.lock);
return 0;
}
@@ -569,11 +587,10 @@ static void __fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
req->out.h.error = -ENOTCONN;
} else {
req->in.h.unique = fuse_get_unique(fiq);
- queue_request(fiq, req);
/* acquire extra reference, since request is still needed
after fuse_request_end() */
__fuse_get_request(req);
- spin_unlock(&fiq->waitq.lock);
+ queue_request_and_unlock(fiq, req);
request_wait_answer(fc, req);
/* Pairs with smp_wmb() in fuse_request_end() */
@@ -706,10 +723,11 @@ static int fuse_request_send_notify_reply(struct fuse_conn *fc,
req->in.h.unique = unique;
spin_lock(&fiq->waitq.lock);
if (fiq->connected) {
- queue_request(fiq, req);
+ queue_request_and_unlock(fiq, req);
err = 0;
+ } else {
+ spin_unlock(&fiq->waitq.lock);
}
- spin_unlock(&fiq->waitq.lock);
return err;
}
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 84f094e4ac36..0b578e07156d 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -71,6 +71,12 @@ struct fuse_mount_data {
unsigned max_read;
unsigned blksize;
+ /* fuse input queue operations */
+ const struct fuse_iqueue_ops *fiq_ops;
+
+ /* device-specific state for fuse_iqueue */
+ void *fiq_priv;
+
/* fuse_dev pointer to fill in, should contain NULL on entry */
void **fudptr;
};
@@ -461,6 +467,39 @@ struct fuse_req {
struct file *stolen_file;
};
+struct fuse_iqueue;
+
+/**
+ * Input queue callbacks
+ *
+ * Input queue signalling is device-specific. For example, the /dev/fuse file
+ * uses fiq->waitq and fasync to wake processes that are waiting on queue
+ * readiness. These callbacks allow other device types to respond to input
+ * queue activity.
+ */
+struct fuse_iqueue_ops {
+ /**
+ * Signal that a forget has been queued
+ */
+ void (*wake_forget_and_unlock)(struct fuse_iqueue *fiq)
+ __releases(fiq->waitq.lock);
+
+ /**
+ * Signal that an INTERRUPT request has been queued
+ */
+ void (*wake_interrupt_and_unlock)(struct fuse_iqueue *fiq)
+ __releases(fiq->waitq.lock);
+
+ /**
+ * Signal that a request has been queued
+ */
+ void (*wake_pending_and_unlock)(struct fuse_iqueue *fiq)
+ __releases(fiq->waitq.lock);
+};
+
+/** /dev/fuse input queue operations */
+extern const struct fuse_iqueue_ops fuse_dev_fiq_ops;
+
struct fuse_iqueue {
/** Connection established */
unsigned connected;
@@ -486,6 +525,12 @@ struct fuse_iqueue {
/** O_ASYNC requests */
struct fasync_struct *fasync;
+
+ /** Device-specific callbacks */
+ const struct fuse_iqueue_ops *ops;
+
+ /** Device-specific state */
+ void *priv;
};
#define FUSE_PQ_HASH_BITS 8
@@ -997,7 +1042,8 @@ struct fuse_conn *fuse_conn_get(struct fuse_conn *fc);
/**
* Initialize fuse_conn
*/
-void fuse_conn_init(struct fuse_conn *fc, struct user_namespace *user_ns);
+void fuse_conn_init(struct fuse_conn *fc, struct user_namespace *user_ns,
+ const struct fuse_iqueue_ops *fiq_ops, void *fiq_priv);
/**
* Release reference to fuse_conn
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index baf2966a753a..126e77854dac 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -570,7 +570,9 @@ static int fuse_show_options(struct seq_file *m, struct dentry *root)
return 0;
}
-static void fuse_iqueue_init(struct fuse_iqueue *fiq)
+static void fuse_iqueue_init(struct fuse_iqueue *fiq,
+ const struct fuse_iqueue_ops *ops,
+ void *priv)
{
memset(fiq, 0, sizeof(struct fuse_iqueue));
init_waitqueue_head(&fiq->waitq);
@@ -578,6 +580,8 @@ static void fuse_iqueue_init(struct fuse_iqueue *fiq)
INIT_LIST_HEAD(&fiq->interrupts);
fiq->forget_list_tail = &fiq->forget_list_head;
fiq->connected = 1;
+ fiq->ops = ops;
+ fiq->priv = priv;
}
static void fuse_pqueue_init(struct fuse_pqueue *fpq)
@@ -591,7 +595,8 @@ static void fuse_pqueue_init(struct fuse_pqueue *fpq)
fpq->connected = 1;
}
-void fuse_conn_init(struct fuse_conn *fc, struct user_namespace *user_ns)
+void fuse_conn_init(struct fuse_conn *fc, struct user_namespace *user_ns,
+ const struct fuse_iqueue_ops *fiq_ops, void *fiq_priv)
{
memset(fc, 0, sizeof(*fc));
spin_lock_init(&fc->lock);
@@ -601,7 +606,7 @@ void fuse_conn_init(struct fuse_conn *fc, struct user_namespace *user_ns)
atomic_set(&fc->dev_count, 1);
init_waitqueue_head(&fc->blocked_waitq);
init_waitqueue_head(&fc->reserved_req_waitq);
- fuse_iqueue_init(&fc->iq);
+ fuse_iqueue_init(&fc->iq, fiq_ops, fiq_priv);
INIT_LIST_HEAD(&fc->bg_queue);
INIT_LIST_HEAD(&fc->entry);
INIT_LIST_HEAD(&fc->devices);
@@ -1113,7 +1118,8 @@ int fuse_fill_super_common(struct super_block *sb,
if (!fc)
goto err;
- fuse_conn_init(fc, sb->s_user_ns);
+ fuse_conn_init(fc, sb->s_user_ns, mount_data->fiq_ops,
+ mount_data->fiq_priv);
fc->release = fuse_free_conn;
fud = fuse_dev_alloc(fc);
@@ -1215,6 +1221,8 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent)
goto err_fput;
__set_bit(FR_BACKGROUND, &init_req->flags);
+ d.fiq_ops = &fuse_dev_fiq_ops;
+ d.fiq_priv = NULL;
d.fudptr = &file->private_data;
err = fuse_fill_super_common(sb, &d);
if (err < 0)
--
2.20.1
next prev parent reply other threads:[~2019-05-15 19:27 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-15 19:26 [PATCH v2 00/30] [RFC] virtio-fs: shared file system for virtual machines Vivek Goyal
2019-05-15 19:26 ` [PATCH v2 01/30] fuse: delete dentry if timeout is zero Vivek Goyal
2019-05-15 19:26 ` [PATCH v2 02/30] fuse: Clear setuid bit even in cache=never path Vivek Goyal
2019-05-20 14:41 ` Miklos Szeredi
2019-05-20 14:44 ` Miklos Szeredi
2019-05-20 20:25 ` Nikolaus Rath
2019-05-21 15:01 ` Vivek Goyal
2019-05-15 19:26 ` [PATCH v2 03/30] fuse: Use default_file_splice_read for direct IO Vivek Goyal
2019-05-15 19:26 ` [PATCH v2 04/30] fuse: export fuse_end_request() Vivek Goyal
2019-05-15 19:26 ` [PATCH v2 05/30] fuse: export fuse_len_args() Vivek Goyal
2019-05-15 19:26 ` [PATCH v2 06/30] fuse: Export fuse_send_init_request() Vivek Goyal
2019-05-15 19:26 ` [PATCH v2 07/30] fuse: export fuse_get_unique() Vivek Goyal
2019-05-15 19:26 ` [PATCH v2 08/30] fuse: extract fuse_fill_super_common() Vivek Goyal
2019-05-15 19:26 ` Vivek Goyal [this message]
2019-05-15 19:26 ` [PATCH v2 10/30] fuse: Separate fuse device allocation and installation in fuse_conn Vivek Goyal
2019-05-15 19:26 ` [PATCH v2 11/30] virtio_fs: add skeleton virtio_fs.ko module Vivek Goyal
2019-05-15 19:26 ` [PATCH v2 12/30] dax: remove block device dependencies Vivek Goyal
2019-05-16 0:21 ` Dan Williams
2019-05-16 10:07 ` Stefan Hajnoczi
2019-05-16 14:23 ` Vivek Goyal
2019-05-15 19:26 ` [PATCH v2 13/30] dax: Pass dax_dev to dax_writeback_mapping_range() Vivek Goyal
2019-05-15 19:26 ` [PATCH v2 14/30] virtio: Add get_shm_region method Vivek Goyal
2019-05-15 19:27 ` [PATCH v2 15/30] virtio: Implement get_shm_region for PCI transport Vivek Goyal
2019-05-15 19:27 ` [PATCH v2 16/30] virtio: Implement get_shm_region for MMIO transport Vivek Goyal
2019-05-15 19:27 ` [PATCH v2 17/30] fuse, dax: add fuse_conn->dax_dev field Vivek Goyal
2019-05-15 19:27 ` [PATCH v2 18/30] virtio_fs, dax: Set up virtio_fs dax_device Vivek Goyal
2019-07-17 17:27 ` Halil Pasic
2019-07-18 9:04 ` Cornelia Huck
2019-07-18 11:20 ` Halil Pasic
2019-07-18 14:47 ` Cornelia Huck
2019-07-18 13:15 ` Vivek Goyal
2019-07-18 14:30 ` Dan Williams
2019-07-22 10:51 ` Christian Borntraeger
2019-07-22 10:56 ` Dr. David Alan Gilbert
2019-07-22 11:20 ` Christian Borntraeger
2019-07-22 11:43 ` Cornelia Huck
2019-07-22 12:00 ` Christian Borntraeger
2019-07-22 12:08 ` David Hildenbrand
2019-07-29 13:20 ` Stefan Hajnoczi
2019-05-15 19:27 ` [PATCH v2 19/30] fuse: Keep a list of free dax memory ranges Vivek Goyal
2019-05-15 19:27 ` [PATCH v2 20/30] fuse: Introduce setupmapping/removemapping commands Vivek Goyal
2019-05-15 19:27 ` [PATCH v2 21/30] fuse, dax: Implement dax read/write operations Vivek Goyal
2019-05-15 19:27 ` [PATCH v2 22/30] fuse, dax: add DAX mmap support Vivek Goyal
2019-05-15 19:27 ` [PATCH v2 23/30] fuse: Define dax address space operations Vivek Goyal
2019-05-15 19:27 ` [PATCH v2 24/30] fuse, dax: Take ->i_mmap_sem lock during dax page fault Vivek Goyal
2019-05-15 19:27 ` [PATCH v2 25/30] fuse: Maintain a list of busy elements Vivek Goyal
2019-05-15 19:27 ` [PATCH v2 26/30] fuse: Add logic to free up a memory range Vivek Goyal
[not found] ` <CAN+Pk99SNKSf+GjSQUUWt_eu1fSjTy_ByUOEQUXHi8zNqXY1zA@mail.gmail.com>
2019-05-20 12:53 ` Vivek Goyal
2019-05-15 19:27 ` [PATCH v2 27/30] fuse: Release file in process context Vivek Goyal
2019-05-15 19:27 ` [PATCH v2 28/30] fuse: Reschedule dax free work if too many EAGAIN attempts Vivek Goyal
2019-05-15 19:27 ` [PATCH v2 29/30] fuse: Take inode lock for dax inode truncation Vivek Goyal
2019-05-15 19:27 ` [PATCH v2 30/30] virtio-fs: Do not provide abort interface in fusectl Vivek Goyal
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