From: Vivek Goyal <vgo...@redhat.com> 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 <vgo...@redhat.com> Signed-off-by: Ioannis Angelakopoulos <iange...@redhat.com> --- include/standard-headers/linux/fuse.h | 8 ++ tools/virtiofsd/fuse_lowlevel.c | 38 +++++++++- tools/virtiofsd/fuse_lowlevel.h | 26 +++++++ tools/virtiofsd/fuse_virtio.c | 101 ++++++++++++++++++++++++-- tools/virtiofsd/passthrough_ll.c | 59 ++++++++++----- 5 files changed, 207 insertions(+), 25 deletions(-) diff --git a/include/standard-headers/linux/fuse.h b/include/standard-headers/linux/fuse.h index 950d7edb7e..4680efc531 100644 --- a/include/standard-headers/linux/fuse.h +++ b/include/standard-headers/linux/fuse.h @@ -511,6 +511,7 @@ enum fuse_notify_code { FUSE_NOTIFY_STORE = 4, FUSE_NOTIFY_RETRIEVE = 5, FUSE_NOTIFY_DELETE = 6, + FUSE_NOTIFY_LOCK = 7, FUSE_NOTIFY_CODE_MAX, }; @@ -898,6 +899,13 @@ 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) diff --git a/tools/virtiofsd/fuse_lowlevel.c b/tools/virtiofsd/fuse_lowlevel.c index 7fe2cef1eb..4b03ec2f9f 100644 --- a/tools/virtiofsd/fuse_lowlevel.c +++ b/tools/virtiofsd/fuse_lowlevel.c @@ -179,8 +179,8 @@ int fuse_send_reply_iov_nofree(fuse_req_t req, int error, struct iovec *iov, .unique = req->unique, .error = error, }; - - 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); out.error = -ERANGE; } @@ -290,6 +290,12 @@ 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); @@ -2145,6 +2151,34 @@ static void do_destroy(fuse_req_t req, fuse_ino_t nodeid, send_reply_ok(req, NULL, 0); } +static int send_notify_iov(struct fuse_session *se, int notify_code, + struct iovec *iov, int count) +{ + struct fuse_out_header out; + if (!se->got_init) { + return -ENOTCONN; + } + out.unique = 0; + out.error = notify_code; + iov[0].iov_base = &out; + iov[0].iov_len = sizeof(struct fuse_out_header); + 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_store(struct fuse_session *se, fuse_ino_t ino, off_t offset, struct fuse_bufvec *bufv) { diff --git a/tools/virtiofsd/fuse_lowlevel.h b/tools/virtiofsd/fuse_lowlevel.h index 3bf786b034..1e8b3d2c35 100644 --- a/tools/virtiofsd/fuse_lowlevel.h +++ b/tools/virtiofsd/fuse_lowlevel.h @@ -1250,6 +1250,22 @@ 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 * @@ -1684,6 +1700,16 @@ int fuse_lowlevel_notify_delete(struct fuse_session *se, fuse_ino_t parent, int fuse_lowlevel_notify_store(struct fuse_session *se, fuse_ino_t ino, off_t offset, struct fuse_bufvec *bufv); +/** + * 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 */ diff --git a/tools/virtiofsd/fuse_virtio.c b/tools/virtiofsd/fuse_virtio.c index f16801bbee..cb4dbafd91 100644 --- a/tools/virtiofsd/fuse_virtio.c +++ b/tools/virtiofsd/fuse_virtio.c @@ -233,6 +233,86 @@ 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)); + 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; +} + /* * pthread_rwlock_rdlock() and pthread_rwlock_wrlock can fail if * a deadlock condition is detected or the current thread already @@ -266,11 +346,11 @@ static void vu_dispatch_unlock(struct fv_VuDev *vud) 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); @@ -281,8 +361,16 @@ 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 */ @@ -867,6 +955,7 @@ 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) + diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c index f2fa9d95bb..8f24954a00 100644 --- a/tools/virtiofsd/passthrough_ll.c +++ b/tools/virtiofsd/passthrough_ll.c @@ -968,14 +968,6 @@ static int do_statx(struct lo_data *lo, int dirfd, const char *pathname, return 0; } -static void posix_locks_value_destroy(gpointer data) -{ - struct lo_inode_plock *plock = data; - - close(plock->fd); - free(plock); -} - /* * Increments nlookup on the inode on success. unref_inode_lolocked() must be * called eventually to decrement nlookup again. If inodep is non-NULL, the @@ -2064,7 +2056,10 @@ static void lo_setlk(fuse_req_t req, fuse_ino_t ino, struct fuse_file_info *fi, 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)" @@ -2078,11 +2073,6 @@ static void lo_setlk(fuse_req_t req, fuse_ino_t ino, struct fuse_file_info *fi, return; } - if (sleep) { - fuse_reply_err(req, EOPNOTSUPP); - return; - } - inode = lo_inode(req, ino); if (!inode) { fuse_reply_err(req, EBADF); @@ -2095,21 +2085,56 @@ static void lo_setlk(fuse_req_t req, fuse_ino_t ino, struct fuse_file_info *fi, 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, -- 2.27.0