@@ -444,6 +444,7 @@ enum fuse_notify_code {
FUSE_NOTIFY_STORE = 4,
FUSE_NOTIFY_RETRIEVE = 5,
FUSE_NOTIFY_DELETE = 6,
+ FUSE_NOTIFY_LOCK = 7,
FUSE_NOTIFY_CODE_MAX,
};
@@ -836,6 +837,12 @@ struct fuse_notify_retrieve_in {
uint64_t dummy4;
};
+struct fuse_notify_lock_out {
+ uint64_t unique;
+ int32_t error;
+ int32_t padding;
+};
+
/* Device ioctls: */
#define FUSE_DEV_IOC_CLONE _IOR(229, 0, uint32_t)
@@ -183,7 +183,8 @@ int fuse_send_reply_iov_nofree(fuse_req_t req, int error, struct iovec *iov,
{
struct fuse_out_header out;
- if (error <= -1000 || error > 0) {
+ /* error = 1 has been used to signal client to wait for notificaiton */
+ if (error <= -1000 || error > 1) {
fuse_log(FUSE_LOG_ERR, "fuse: bad error value: %i\n", error);
error = -ERANGE;
}
@@ -291,6 +292,12 @@ int fuse_reply_err(fuse_req_t req, int err)
return send_reply(req, -err, NULL, 0);
}
+int fuse_reply_wait(fuse_req_t req)
+{
+ /* TODO: This is a hack. Fix it */
+ return send_reply(req, 1, NULL, 0);
+}
+
void fuse_reply_none(fuse_req_t req)
{
fuse_free_req(req);
@@ -2207,6 +2214,20 @@ static int send_notify_iov(struct fuse_session *se, int notify_code,
return fuse_send_msg(se, NULL, iov, count);
}
+int fuse_lowlevel_notify_lock(struct fuse_session *se, uint64_t unique,
+ int32_t error)
+{
+ struct fuse_notify_lock_out outarg = {0};
+ struct iovec iov[2];
+
+ outarg.unique = unique;
+ outarg.error = -error;
+
+ iov[1].iov_base = &outarg;
+ iov[1].iov_len = sizeof(outarg);
+ return send_notify_iov(se, FUSE_NOTIFY_LOCK, iov, 2);
+}
+
int fuse_lowlevel_notify_poll(struct fuse_pollhandle *ph)
{
if (ph != NULL) {
@@ -1251,6 +1251,22 @@ struct fuse_lowlevel_ops {
*/
int fuse_reply_err(fuse_req_t req, int err);
+/**
+ * Ask caller to wait for lock.
+ *
+ * Possible requests:
+ * setlkw
+ *
+ * If caller sends a blocking lock request (setlkw), then reply to caller
+ * that wait for lock to be available. Once lock is available caller will
+ * receive a notification with request's unique id. Notification will
+ * carry info whether lock was successfully obtained or not.
+ *
+ * @param req request handle
+ * @return zero for success, -errno for failure to send reply
+ */
+int fuse_reply_wait(fuse_req_t req);
+
/**
* Don't send reply
*
@@ -1704,6 +1720,15 @@ int fuse_lowlevel_notify_delete(struct fuse_session *se,
int fuse_lowlevel_notify_store(struct fuse_session *se, fuse_ino_t ino,
off_t offset, struct fuse_bufvec *bufv,
enum fuse_buf_copy_flags flags);
+/**
+ * Notify event related to previous lock request
+ *
+ * @param se the session object
+ * @param unique the unique id of the request which requested setlkw
+ * @param error zero for success, -errno for the failure
+ */
+int fuse_lowlevel_notify_lock(struct fuse_session *se, uint64_t unique,
+ int32_t error);
/* ----------------------------------------------------------- *
* Utility functions *
@@ -208,6 +208,83 @@ static void copy_iov(struct iovec *src_iov, int src_count,
}
}
+static int virtio_send_notify_msg(struct fuse_session *se, struct iovec *iov,
+ int count)
+{
+ struct fv_QueueInfo *qi;
+ VuDev *dev = &se->virtio_dev->dev;
+ VuVirtq *q;
+ FVRequest *req;
+ VuVirtqElement *elem;
+ unsigned int in_num;
+ struct fuse_out_header *out = iov[0].iov_base;
+ size_t in_len, tosend_len = iov_size(iov, count);
+ struct iovec *in_sg;
+ int ret = 0;
+
+ /* Notifications have unique == 0 */
+ assert (!out->unique);
+
+ if (!se->notify_enabled)
+ return -EOPNOTSUPP;
+
+ /* If notifications are enabled, queue index 1 is notification queue */
+ qi = se->virtio_dev->qi[1];
+ q = vu_get_queue(dev, qi->qidx);
+
+ pthread_rwlock_rdlock(&qi->virtio_dev->vu_dispatch_rwlock);
+ pthread_mutex_lock(&qi->vq_lock);
+ /* Pop an element from queue */
+ req = vu_queue_pop(dev, q, sizeof(FVRequest), NULL, NULL);
+ if (!req) {
+ /* TODO: Implement some sort of ring buffer and queue notifications
+ * on that and send these later when notification queue has space
+ * available.
+ */
+ ret = -ENOSPC;
+ }
+ pthread_mutex_unlock(&qi->vq_lock);
+ pthread_rwlock_unlock(&qi->virtio_dev->vu_dispatch_rwlock);
+
+ if (ret)
+ return ret;
+
+ out->len = tosend_len;
+ elem = &req->elem;
+ in_num = elem->in_num;
+ in_sg = elem->in_sg;
+ in_len = iov_size(in_sg, in_num);
+ fuse_log(FUSE_LOG_DEBUG, "%s: elem %d: with %d in desc of length %zd\n",
+ __func__, elem->index, in_num, in_len);
+
+ if (in_len < sizeof(struct fuse_out_header)) {
+ fuse_log(FUSE_LOG_ERR, "%s: elem %d too short for out_header\n",
+ __func__, elem->index);
+ ret = -E2BIG;
+ goto out;
+ }
+
+ if (in_len < tosend_len) {
+ fuse_log(FUSE_LOG_ERR, "%s: elem %d too small for data len"
+ " %zd\n", __func__, elem->index, tosend_len);
+ ret = -E2BIG;
+ goto out;
+ }
+
+ /* First copy the header data from iov->in_sg */
+ copy_iov(iov, count, in_sg, in_num, tosend_len);
+
+ pthread_rwlock_rdlock(&qi->virtio_dev->vu_dispatch_rwlock);
+ pthread_mutex_lock(&qi->vq_lock);
+ vu_queue_push(dev, q, elem, tosend_len);
+ vu_queue_notify(dev, q);
+ pthread_mutex_unlock(&qi->vq_lock);
+ pthread_rwlock_unlock(&qi->virtio_dev->vu_dispatch_rwlock);
+out:
+ free(req);
+ return ret;
+}
+
/*
* Called back by ll whenever it wants to send a reply/message back
* The 1st element of the iov starts with the fuse_out_header
@@ -216,11 +293,11 @@ static void copy_iov(struct iovec *src_iov, int src_count,
int virtio_send_msg(struct fuse_session *se, struct fuse_chan *ch,
struct iovec *iov, int count)
{
- FVRequest *req = container_of(ch, FVRequest, ch);
- struct fv_QueueInfo *qi = ch->qi;
+ FVRequest *req;
+ struct fv_QueueInfo *qi;
VuDev *dev = &se->virtio_dev->dev;
- VuVirtq *q = vu_get_queue(dev, qi->qidx);
- VuVirtqElement *elem = &req->elem;
+ VuVirtq *q;
+ VuVirtqElement *elem;
int ret = 0;
assert(count >= 1);
@@ -231,8 +308,15 @@ int virtio_send_msg(struct fuse_session *se, struct fuse_chan *ch,
size_t tosend_len = iov_size(iov, count);
- /* unique == 0 is notification, which we don't support */
- assert(out->unique);
+ /* unique == 0 is notification */
+ if (!out->unique)
+ return virtio_send_notify_msg(se, iov, count);
+
+ assert(ch);
+ req = container_of(ch, FVRequest, ch);
+ elem = &req->elem;
+ qi = ch->qi;
+ q = vu_get_queue(dev, qi->qidx);
assert(!req->reply_sent);
/* The 'in' part of the elem is to qemu */
@@ -885,6 +969,7 @@ static int fv_get_config(VuDev *dev, uint8_t *config, uint32_t len)
struct fuse_notify_delete_out delete_out;
struct fuse_notify_store_out store_out;
struct fuse_notify_retrieve_out retrieve_out;
+ struct fuse_notify_lock_out lock_out;
};
notify_size = sizeof(struct fuse_out_header) +
@@ -1926,7 +1926,10 @@ static void lo_setlk(fuse_req_t req, fuse_ino_t ino,
struct lo_data *lo = lo_data(req);
struct lo_inode *inode;
struct lo_inode_plock *plock;
- int ret, saverr = 0;
+ int ret, saverr = 0, ofd;
+ uint64_t unique;
+ struct fuse_session *se = req->se;
+ bool async_lock = false;
fuse_log(FUSE_LOG_DEBUG, "lo_setlk(ino=%" PRIu64 ", flags=%d)"
" cmd=%d pid=%d owner=0x%lx sleep=%d l_whence=%d"
@@ -1934,11 +1937,6 @@ static void lo_setlk(fuse_req_t req, fuse_ino_t ino,
lock->l_type, lock->l_pid, fi->lock_owner, sleep,
lock->l_whence, lock->l_start, lock->l_len);
- if (sleep) {
- fuse_reply_err(req, EOPNOTSUPP);
- return;
- }
-
inode = lo_inode(req, ino);
if (!inode) {
fuse_reply_err(req, EBADF);
@@ -1951,21 +1949,54 @@ static void lo_setlk(fuse_req_t req, fuse_ino_t ino,
if (!plock) {
saverr = ret;
+ pthread_mutex_unlock(&inode->plock_mutex);
goto out;
}
+ /*
+ * plock is now released when inode is going away. We already have
+ * a reference on inode, so it is guaranteed that plock->fd is
+ * still around even after dropping inode->plock_mutex lock
+ */
+ ofd = plock->fd;
+ pthread_mutex_unlock(&inode->plock_mutex);
+
+ /*
+ * If this lock request can block, request caller to wait for
+ * notification. Do not access req after this. Once lock is
+ * available, send a notification instead.
+ */
+ if (sleep && lock->l_type != F_UNLCK) {
+ /*
+ * If notification queue is not enabled, can't support async
+ * locks.
+ */
+ if (!se->notify_enabled) {
+ saverr = EOPNOTSUPP;
+ goto out;
+ }
+ async_lock = true;
+ unique = req->unique;
+ fuse_reply_wait(req);
+ }
/* TODO: Is it alright to modify flock? */
lock->l_pid = 0;
- ret = fcntl(plock->fd, F_OFD_SETLK, lock);
+ if (async_lock)
+ ret = fcntl(ofd, F_OFD_SETLKW, lock);
+ else
+ ret = fcntl(ofd, F_OFD_SETLK, lock);
if (ret == -1) {
saverr = errno;
}
out:
- pthread_mutex_unlock(&inode->plock_mutex);
lo_inode_put(lo, &inode);
- fuse_reply_err(req, saverr);
+ if (!async_lock)
+ fuse_reply_err(req, saverr);
+ else {
+ fuse_lowlevel_notify_lock(se, unique, saverr);
+ }
}
static void lo_fsyncdir(fuse_req_t req, fuse_ino_t ino, int datasync,
As of now we don't support fcntl(F_SETLKW) and if we see one, we return -EOPNOTSUPP. Change that by accepting these requests and returning a reply immediately asking caller to wait. Once lock is available, send a notification to the waiter indicating lock is available. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> --- contrib/virtiofsd/fuse_kernel.h | 7 +++ contrib/virtiofsd/fuse_lowlevel.c | 23 ++++++- contrib/virtiofsd/fuse_lowlevel.h | 25 ++++++++ contrib/virtiofsd/fuse_virtio.c | 97 ++++++++++++++++++++++++++++-- contrib/virtiofsd/passthrough_ll.c | 49 ++++++++++++--- 5 files changed, 185 insertions(+), 16 deletions(-)