|
|
From: Jeff Dike <jdike@xxxxxxxxxxx>
This adds asynchronous notification to FUSE - a FUSE server can
request O_ASYNC on a /dev/fuse file descriptor and receive SIGIO
when there is input available.
One subtlety - fuse_dev_fasync, which is called when O_ASYNC is
requested, does no locking, unlink the other methods. I think it's
unnecessary, as the fuse_conn.fasync list is manipulated only by
fasync_helper and kill_fasync, which provide their own locking. It
would also be wrong to use the fuse_lock, as it's a spin lock and
fasync_helper can sleep. My one concern with this is the fuse_conn
going away underneath fuse_dev_fasync - sys_fcntl takes a reference
on the file struct, so this seems not to be a problem.
Signed-off-by: Jeff Dike <jdike@xxxxxxxxxxx>
Signed-off-by: Miklos Szeredi <miklos@xxxxxxxxxx>
Index: linux/fs/fuse/dev.c
===================================================================
--- linux.orig/fs/fuse/dev.c 2006-03-31 18:55:30.000000000 +0200
+++ linux/fs/fuse/dev.c 2006-03-31 18:55:31.000000000 +0200
@@ -317,6 +317,7 @@ static void queue_request(struct fuse_co
list_add_tail(&req->list, &fc->pending);
req->state = FUSE_REQ_PENDING;
wake_up(&fc->waitq);
+ kill_fasync(&fc->fasync, SIGIO, POLL_IN);
}
/*
@@ -901,6 +902,7 @@ void fuse_abort_conn(struct fuse_conn *f
end_requests(fc, &fc->pending);
end_requests(fc, &fc->processing);
wake_up_all(&fc->waitq);
+ kill_fasync(&fc->fasync, SIGIO, POLL_IN);
}
spin_unlock(&fuse_lock);
}
@@ -917,12 +919,24 @@ static int fuse_dev_release(struct inode
end_requests(fc, &fc->processing);
}
spin_unlock(&fuse_lock);
- if (fc)
+ if (fc) {
+ fasync_helper(-1, file, 0, &fc->fasync);
kobject_put(&fc->kobj);
+ }
return 0;
}
+static int fuse_dev_fasync(int fd, struct file *file, int on)
+{
+ struct fuse_conn *fc = fuse_get_conn(file);
+ if (!fc)
+ return -ENODEV;
+
+ /* No locking - fasync_helper does its own locking */
+ return fasync_helper(fd, file, on, &fc->fasync);
+}
+
const struct file_operations fuse_dev_operations = {
.owner = THIS_MODULE,
.llseek = no_llseek,
@@ -932,6 +946,7 @@ const struct file_operations fuse_dev_op
.writev = fuse_dev_writev,
.poll = fuse_dev_poll,
.release = fuse_dev_release,
+ .fasync = fuse_dev_fasync,
};
static struct miscdevice fuse_miscdevice = {
Index: linux/fs/fuse/fuse_i.h
===================================================================
--- linux.orig/fs/fuse/fuse_i.h 2006-03-31 18:55:11.000000000 +0200
+++ linux/fs/fuse/fuse_i.h 2006-03-31 18:55:31.000000000 +0200
@@ -318,6 +318,9 @@ struct fuse_conn {
/** kobject */
struct kobject kobj;
+
+ /** O_ASYNC requests */
+ struct fasync_struct *fasync;
};
static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
Index: linux/fs/fuse/inode.c
===================================================================
--- linux.orig/fs/fuse/inode.c 2006-03-31 18:55:11.000000000 +0200
+++ linux/fs/fuse/inode.c 2006-03-31 18:55:31.000000000 +0200
@@ -216,6 +216,7 @@ static void fuse_put_super(struct super_
spin_unlock(&fuse_lock);
up_write(&fc->sbput_sem);
/* Flush all readers on this fs */
+ kill_fasync(&fc->fasync, SIGIO, POLL_IN);
wake_up_all(&fc->waitq);
kobject_del(&fc->kobj);
kobject_put(&fc->kobj);
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at www.tux.org/lkml/">http://www.tux.org/lkml/
|
|