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![Deming Wang](/assets/img/avatar_default.png)
We should isolate operators with spaces. Signed-off-by: Deming Wang <wangdeming@inspur.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
1541 lines
37 KiB
C
1541 lines
37 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* virtio-fs: Virtio Filesystem
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* Copyright (C) 2018 Red Hat, Inc.
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*/
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#include <linux/fs.h>
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#include <linux/dax.h>
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#include <linux/pci.h>
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#include <linux/pfn_t.h>
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#include <linux/memremap.h>
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#include <linux/module.h>
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#include <linux/virtio.h>
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#include <linux/virtio_fs.h>
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#include <linux/delay.h>
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#include <linux/fs_context.h>
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#include <linux/fs_parser.h>
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#include <linux/highmem.h>
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#include <linux/uio.h>
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#include "fuse_i.h"
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/* Used to help calculate the FUSE connection's max_pages limit for a request's
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* size. Parts of the struct fuse_req are sliced into scattergather lists in
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* addition to the pages used, so this can help account for that overhead.
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*/
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#define FUSE_HEADER_OVERHEAD 4
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/* List of virtio-fs device instances and a lock for the list. Also provides
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* mutual exclusion in device removal and mounting path
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*/
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static DEFINE_MUTEX(virtio_fs_mutex);
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static LIST_HEAD(virtio_fs_instances);
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enum {
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VQ_HIPRIO,
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VQ_REQUEST
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};
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#define VQ_NAME_LEN 24
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/* Per-virtqueue state */
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struct virtio_fs_vq {
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spinlock_t lock;
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struct virtqueue *vq; /* protected by ->lock */
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struct work_struct done_work;
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struct list_head queued_reqs;
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struct list_head end_reqs; /* End these requests */
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struct delayed_work dispatch_work;
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struct fuse_dev *fud;
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bool connected;
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long in_flight;
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struct completion in_flight_zero; /* No inflight requests */
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char name[VQ_NAME_LEN];
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} ____cacheline_aligned_in_smp;
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/* A virtio-fs device instance */
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struct virtio_fs {
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struct kref refcount;
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struct list_head list; /* on virtio_fs_instances */
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char *tag;
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struct virtio_fs_vq *vqs;
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unsigned int nvqs; /* number of virtqueues */
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unsigned int num_request_queues; /* number of request queues */
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struct dax_device *dax_dev;
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/* DAX memory window where file contents are mapped */
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void *window_kaddr;
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phys_addr_t window_phys_addr;
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size_t window_len;
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};
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struct virtio_fs_forget_req {
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struct fuse_in_header ih;
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struct fuse_forget_in arg;
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};
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struct virtio_fs_forget {
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/* This request can be temporarily queued on virt queue */
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struct list_head list;
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struct virtio_fs_forget_req req;
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};
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struct virtio_fs_req_work {
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struct fuse_req *req;
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struct virtio_fs_vq *fsvq;
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struct work_struct done_work;
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};
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static int virtio_fs_enqueue_req(struct virtio_fs_vq *fsvq,
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struct fuse_req *req, bool in_flight);
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static const struct constant_table dax_param_enums[] = {
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{"always", FUSE_DAX_ALWAYS },
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{"never", FUSE_DAX_NEVER },
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{"inode", FUSE_DAX_INODE_USER },
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{}
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};
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enum {
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OPT_DAX,
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OPT_DAX_ENUM,
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};
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static const struct fs_parameter_spec virtio_fs_parameters[] = {
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fsparam_flag("dax", OPT_DAX),
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fsparam_enum("dax", OPT_DAX_ENUM, dax_param_enums),
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{}
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};
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static int virtio_fs_parse_param(struct fs_context *fsc,
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struct fs_parameter *param)
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{
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struct fs_parse_result result;
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struct fuse_fs_context *ctx = fsc->fs_private;
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int opt;
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opt = fs_parse(fsc, virtio_fs_parameters, param, &result);
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if (opt < 0)
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return opt;
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switch (opt) {
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case OPT_DAX:
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ctx->dax_mode = FUSE_DAX_ALWAYS;
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break;
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case OPT_DAX_ENUM:
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ctx->dax_mode = result.uint_32;
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break;
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default:
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return -EINVAL;
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}
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return 0;
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}
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static void virtio_fs_free_fsc(struct fs_context *fsc)
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{
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struct fuse_fs_context *ctx = fsc->fs_private;
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kfree(ctx);
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}
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static inline struct virtio_fs_vq *vq_to_fsvq(struct virtqueue *vq)
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{
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struct virtio_fs *fs = vq->vdev->priv;
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return &fs->vqs[vq->index];
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}
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/* Should be called with fsvq->lock held. */
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static inline void inc_in_flight_req(struct virtio_fs_vq *fsvq)
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{
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fsvq->in_flight++;
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}
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/* Should be called with fsvq->lock held. */
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static inline void dec_in_flight_req(struct virtio_fs_vq *fsvq)
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{
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WARN_ON(fsvq->in_flight <= 0);
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fsvq->in_flight--;
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if (!fsvq->in_flight)
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complete(&fsvq->in_flight_zero);
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}
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static void release_virtio_fs_obj(struct kref *ref)
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{
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struct virtio_fs *vfs = container_of(ref, struct virtio_fs, refcount);
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kfree(vfs->vqs);
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kfree(vfs);
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}
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/* Make sure virtiofs_mutex is held */
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static void virtio_fs_put(struct virtio_fs *fs)
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{
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kref_put(&fs->refcount, release_virtio_fs_obj);
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}
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static void virtio_fs_fiq_release(struct fuse_iqueue *fiq)
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{
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struct virtio_fs *vfs = fiq->priv;
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mutex_lock(&virtio_fs_mutex);
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virtio_fs_put(vfs);
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mutex_unlock(&virtio_fs_mutex);
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}
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static void virtio_fs_drain_queue(struct virtio_fs_vq *fsvq)
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{
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WARN_ON(fsvq->in_flight < 0);
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/* Wait for in flight requests to finish.*/
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spin_lock(&fsvq->lock);
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if (fsvq->in_flight) {
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/* We are holding virtio_fs_mutex. There should not be any
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* waiters waiting for completion.
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*/
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reinit_completion(&fsvq->in_flight_zero);
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spin_unlock(&fsvq->lock);
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wait_for_completion(&fsvq->in_flight_zero);
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} else {
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spin_unlock(&fsvq->lock);
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}
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flush_work(&fsvq->done_work);
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flush_delayed_work(&fsvq->dispatch_work);
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}
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static void virtio_fs_drain_all_queues_locked(struct virtio_fs *fs)
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{
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struct virtio_fs_vq *fsvq;
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int i;
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for (i = 0; i < fs->nvqs; i++) {
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fsvq = &fs->vqs[i];
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virtio_fs_drain_queue(fsvq);
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}
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}
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static void virtio_fs_drain_all_queues(struct virtio_fs *fs)
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{
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/* Provides mutual exclusion between ->remove and ->kill_sb
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* paths. We don't want both of these draining queue at the
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* same time. Current completion logic reinits completion
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* and that means there should not be any other thread
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* doing reinit or waiting for completion already.
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*/
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mutex_lock(&virtio_fs_mutex);
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virtio_fs_drain_all_queues_locked(fs);
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mutex_unlock(&virtio_fs_mutex);
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}
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static void virtio_fs_start_all_queues(struct virtio_fs *fs)
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{
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struct virtio_fs_vq *fsvq;
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int i;
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for (i = 0; i < fs->nvqs; i++) {
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fsvq = &fs->vqs[i];
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spin_lock(&fsvq->lock);
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fsvq->connected = true;
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spin_unlock(&fsvq->lock);
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}
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}
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/* Add a new instance to the list or return -EEXIST if tag name exists*/
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static int virtio_fs_add_instance(struct virtio_fs *fs)
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{
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struct virtio_fs *fs2;
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bool duplicate = false;
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mutex_lock(&virtio_fs_mutex);
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list_for_each_entry(fs2, &virtio_fs_instances, list) {
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if (strcmp(fs->tag, fs2->tag) == 0)
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duplicate = true;
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}
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if (!duplicate)
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list_add_tail(&fs->list, &virtio_fs_instances);
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mutex_unlock(&virtio_fs_mutex);
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if (duplicate)
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return -EEXIST;
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return 0;
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}
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/* Return the virtio_fs with a given tag, or NULL */
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static struct virtio_fs *virtio_fs_find_instance(const char *tag)
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{
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struct virtio_fs *fs;
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mutex_lock(&virtio_fs_mutex);
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list_for_each_entry(fs, &virtio_fs_instances, list) {
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if (strcmp(fs->tag, tag) == 0) {
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kref_get(&fs->refcount);
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goto found;
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}
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}
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fs = NULL; /* not found */
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found:
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mutex_unlock(&virtio_fs_mutex);
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return fs;
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}
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static void virtio_fs_free_devs(struct virtio_fs *fs)
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{
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unsigned int i;
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for (i = 0; i < fs->nvqs; i++) {
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struct virtio_fs_vq *fsvq = &fs->vqs[i];
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if (!fsvq->fud)
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continue;
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fuse_dev_free(fsvq->fud);
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fsvq->fud = NULL;
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}
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}
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/* Read filesystem name from virtio config into fs->tag (must kfree()). */
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static int virtio_fs_read_tag(struct virtio_device *vdev, struct virtio_fs *fs)
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{
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char tag_buf[sizeof_field(struct virtio_fs_config, tag)];
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char *end;
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size_t len;
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virtio_cread_bytes(vdev, offsetof(struct virtio_fs_config, tag),
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&tag_buf, sizeof(tag_buf));
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end = memchr(tag_buf, '\0', sizeof(tag_buf));
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if (end == tag_buf)
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return -EINVAL; /* empty tag */
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if (!end)
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end = &tag_buf[sizeof(tag_buf)];
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len = end - tag_buf;
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fs->tag = devm_kmalloc(&vdev->dev, len + 1, GFP_KERNEL);
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if (!fs->tag)
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return -ENOMEM;
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memcpy(fs->tag, tag_buf, len);
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fs->tag[len] = '\0';
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return 0;
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}
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/* Work function for hiprio completion */
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static void virtio_fs_hiprio_done_work(struct work_struct *work)
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{
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struct virtio_fs_vq *fsvq = container_of(work, struct virtio_fs_vq,
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done_work);
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struct virtqueue *vq = fsvq->vq;
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/* Free completed FUSE_FORGET requests */
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spin_lock(&fsvq->lock);
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do {
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unsigned int len;
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void *req;
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virtqueue_disable_cb(vq);
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while ((req = virtqueue_get_buf(vq, &len)) != NULL) {
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kfree(req);
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dec_in_flight_req(fsvq);
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}
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} while (!virtqueue_enable_cb(vq) && likely(!virtqueue_is_broken(vq)));
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spin_unlock(&fsvq->lock);
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}
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static void virtio_fs_request_dispatch_work(struct work_struct *work)
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{
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struct fuse_req *req;
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struct virtio_fs_vq *fsvq = container_of(work, struct virtio_fs_vq,
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dispatch_work.work);
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int ret;
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pr_debug("virtio-fs: worker %s called.\n", __func__);
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while (1) {
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spin_lock(&fsvq->lock);
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req = list_first_entry_or_null(&fsvq->end_reqs, struct fuse_req,
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list);
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if (!req) {
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spin_unlock(&fsvq->lock);
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break;
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}
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list_del_init(&req->list);
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spin_unlock(&fsvq->lock);
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fuse_request_end(req);
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}
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/* Dispatch pending requests */
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while (1) {
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spin_lock(&fsvq->lock);
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req = list_first_entry_or_null(&fsvq->queued_reqs,
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struct fuse_req, list);
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if (!req) {
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spin_unlock(&fsvq->lock);
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return;
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}
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list_del_init(&req->list);
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spin_unlock(&fsvq->lock);
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ret = virtio_fs_enqueue_req(fsvq, req, true);
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if (ret < 0) {
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if (ret == -ENOMEM || ret == -ENOSPC) {
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spin_lock(&fsvq->lock);
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list_add_tail(&req->list, &fsvq->queued_reqs);
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schedule_delayed_work(&fsvq->dispatch_work,
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msecs_to_jiffies(1));
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spin_unlock(&fsvq->lock);
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return;
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}
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req->out.h.error = ret;
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spin_lock(&fsvq->lock);
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dec_in_flight_req(fsvq);
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spin_unlock(&fsvq->lock);
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pr_err("virtio-fs: virtio_fs_enqueue_req() failed %d\n",
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ret);
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fuse_request_end(req);
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}
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}
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}
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/*
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* Returns 1 if queue is full and sender should wait a bit before sending
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* next request, 0 otherwise.
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*/
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static int send_forget_request(struct virtio_fs_vq *fsvq,
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struct virtio_fs_forget *forget,
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bool in_flight)
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{
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struct scatterlist sg;
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struct virtqueue *vq;
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int ret = 0;
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bool notify;
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struct virtio_fs_forget_req *req = &forget->req;
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spin_lock(&fsvq->lock);
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if (!fsvq->connected) {
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if (in_flight)
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dec_in_flight_req(fsvq);
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kfree(forget);
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goto out;
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}
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sg_init_one(&sg, req, sizeof(*req));
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vq = fsvq->vq;
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dev_dbg(&vq->vdev->dev, "%s\n", __func__);
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ret = virtqueue_add_outbuf(vq, &sg, 1, forget, GFP_ATOMIC);
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if (ret < 0) {
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if (ret == -ENOMEM || ret == -ENOSPC) {
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pr_debug("virtio-fs: Could not queue FORGET: err=%d. Will try later\n",
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ret);
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list_add_tail(&forget->list, &fsvq->queued_reqs);
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schedule_delayed_work(&fsvq->dispatch_work,
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msecs_to_jiffies(1));
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if (!in_flight)
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inc_in_flight_req(fsvq);
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/* Queue is full */
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ret = 1;
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} else {
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pr_debug("virtio-fs: Could not queue FORGET: err=%d. Dropping it.\n",
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ret);
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kfree(forget);
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if (in_flight)
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dec_in_flight_req(fsvq);
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}
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goto out;
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}
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if (!in_flight)
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inc_in_flight_req(fsvq);
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notify = virtqueue_kick_prepare(vq);
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spin_unlock(&fsvq->lock);
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if (notify)
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virtqueue_notify(vq);
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return ret;
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out:
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spin_unlock(&fsvq->lock);
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return ret;
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}
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|
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static void virtio_fs_hiprio_dispatch_work(struct work_struct *work)
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{
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struct virtio_fs_forget *forget;
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struct virtio_fs_vq *fsvq = container_of(work, struct virtio_fs_vq,
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dispatch_work.work);
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pr_debug("virtio-fs: worker %s called.\n", __func__);
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while (1) {
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spin_lock(&fsvq->lock);
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forget = list_first_entry_or_null(&fsvq->queued_reqs,
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struct virtio_fs_forget, list);
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if (!forget) {
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spin_unlock(&fsvq->lock);
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return;
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}
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list_del(&forget->list);
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spin_unlock(&fsvq->lock);
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if (send_forget_request(fsvq, forget, true))
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return;
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}
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}
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|
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/* Allocate and copy args into req->argbuf */
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static int copy_args_to_argbuf(struct fuse_req *req)
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{
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struct fuse_args *args = req->args;
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unsigned int offset = 0;
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unsigned int num_in;
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unsigned int num_out;
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unsigned int len;
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unsigned int i;
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num_in = args->in_numargs - args->in_pages;
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num_out = args->out_numargs - args->out_pages;
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len = fuse_len_args(num_in, (struct fuse_arg *) args->in_args) +
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fuse_len_args(num_out, args->out_args);
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|
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req->argbuf = kmalloc(len, GFP_ATOMIC);
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if (!req->argbuf)
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return -ENOMEM;
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|
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for (i = 0; i < num_in; i++) {
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memcpy(req->argbuf + offset,
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args->in_args[i].value,
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args->in_args[i].size);
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offset += args->in_args[i].size;
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}
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return 0;
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|
}
|
|
|
|
/* Copy args out of and free req->argbuf */
|
|
static void copy_args_from_argbuf(struct fuse_args *args, struct fuse_req *req)
|
|
{
|
|
unsigned int remaining;
|
|
unsigned int offset;
|
|
unsigned int num_in;
|
|
unsigned int num_out;
|
|
unsigned int i;
|
|
|
|
remaining = req->out.h.len - sizeof(req->out.h);
|
|
num_in = args->in_numargs - args->in_pages;
|
|
num_out = args->out_numargs - args->out_pages;
|
|
offset = fuse_len_args(num_in, (struct fuse_arg *)args->in_args);
|
|
|
|
for (i = 0; i < num_out; i++) {
|
|
unsigned int argsize = args->out_args[i].size;
|
|
|
|
if (args->out_argvar &&
|
|
i == args->out_numargs - 1 &&
|
|
argsize > remaining) {
|
|
argsize = remaining;
|
|
}
|
|
|
|
memcpy(args->out_args[i].value, req->argbuf + offset, argsize);
|
|
offset += argsize;
|
|
|
|
if (i != args->out_numargs - 1)
|
|
remaining -= argsize;
|
|
}
|
|
|
|
/* Store the actual size of the variable-length arg */
|
|
if (args->out_argvar)
|
|
args->out_args[args->out_numargs - 1].size = remaining;
|
|
|
|
kfree(req->argbuf);
|
|
req->argbuf = NULL;
|
|
}
|
|
|
|
/* Work function for request completion */
|
|
static void virtio_fs_request_complete(struct fuse_req *req,
|
|
struct virtio_fs_vq *fsvq)
|
|
{
|
|
struct fuse_pqueue *fpq = &fsvq->fud->pq;
|
|
struct fuse_args *args;
|
|
struct fuse_args_pages *ap;
|
|
unsigned int len, i, thislen;
|
|
struct page *page;
|
|
|
|
/*
|
|
* TODO verify that server properly follows FUSE protocol
|
|
* (oh.uniq, oh.len)
|
|
*/
|
|
args = req->args;
|
|
copy_args_from_argbuf(args, req);
|
|
|
|
if (args->out_pages && args->page_zeroing) {
|
|
len = args->out_args[args->out_numargs - 1].size;
|
|
ap = container_of(args, typeof(*ap), args);
|
|
for (i = 0; i < ap->num_pages; i++) {
|
|
thislen = ap->descs[i].length;
|
|
if (len < thislen) {
|
|
WARN_ON(ap->descs[i].offset);
|
|
page = ap->pages[i];
|
|
zero_user_segment(page, len, thislen);
|
|
len = 0;
|
|
} else {
|
|
len -= thislen;
|
|
}
|
|
}
|
|
}
|
|
|
|
spin_lock(&fpq->lock);
|
|
clear_bit(FR_SENT, &req->flags);
|
|
spin_unlock(&fpq->lock);
|
|
|
|
fuse_request_end(req);
|
|
spin_lock(&fsvq->lock);
|
|
dec_in_flight_req(fsvq);
|
|
spin_unlock(&fsvq->lock);
|
|
}
|
|
|
|
static void virtio_fs_complete_req_work(struct work_struct *work)
|
|
{
|
|
struct virtio_fs_req_work *w =
|
|
container_of(work, typeof(*w), done_work);
|
|
|
|
virtio_fs_request_complete(w->req, w->fsvq);
|
|
kfree(w);
|
|
}
|
|
|
|
static void virtio_fs_requests_done_work(struct work_struct *work)
|
|
{
|
|
struct virtio_fs_vq *fsvq = container_of(work, struct virtio_fs_vq,
|
|
done_work);
|
|
struct fuse_pqueue *fpq = &fsvq->fud->pq;
|
|
struct virtqueue *vq = fsvq->vq;
|
|
struct fuse_req *req;
|
|
struct fuse_req *next;
|
|
unsigned int len;
|
|
LIST_HEAD(reqs);
|
|
|
|
/* Collect completed requests off the virtqueue */
|
|
spin_lock(&fsvq->lock);
|
|
do {
|
|
virtqueue_disable_cb(vq);
|
|
|
|
while ((req = virtqueue_get_buf(vq, &len)) != NULL) {
|
|
spin_lock(&fpq->lock);
|
|
list_move_tail(&req->list, &reqs);
|
|
spin_unlock(&fpq->lock);
|
|
}
|
|
} while (!virtqueue_enable_cb(vq) && likely(!virtqueue_is_broken(vq)));
|
|
spin_unlock(&fsvq->lock);
|
|
|
|
/* End requests */
|
|
list_for_each_entry_safe(req, next, &reqs, list) {
|
|
list_del_init(&req->list);
|
|
|
|
/* blocking async request completes in a worker context */
|
|
if (req->args->may_block) {
|
|
struct virtio_fs_req_work *w;
|
|
|
|
w = kzalloc(sizeof(*w), GFP_NOFS | __GFP_NOFAIL);
|
|
INIT_WORK(&w->done_work, virtio_fs_complete_req_work);
|
|
w->fsvq = fsvq;
|
|
w->req = req;
|
|
schedule_work(&w->done_work);
|
|
} else {
|
|
virtio_fs_request_complete(req, fsvq);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Virtqueue interrupt handler */
|
|
static void virtio_fs_vq_done(struct virtqueue *vq)
|
|
{
|
|
struct virtio_fs_vq *fsvq = vq_to_fsvq(vq);
|
|
|
|
dev_dbg(&vq->vdev->dev, "%s %s\n", __func__, fsvq->name);
|
|
|
|
schedule_work(&fsvq->done_work);
|
|
}
|
|
|
|
static void virtio_fs_init_vq(struct virtio_fs_vq *fsvq, char *name,
|
|
int vq_type)
|
|
{
|
|
strscpy(fsvq->name, name, VQ_NAME_LEN);
|
|
spin_lock_init(&fsvq->lock);
|
|
INIT_LIST_HEAD(&fsvq->queued_reqs);
|
|
INIT_LIST_HEAD(&fsvq->end_reqs);
|
|
init_completion(&fsvq->in_flight_zero);
|
|
|
|
if (vq_type == VQ_REQUEST) {
|
|
INIT_WORK(&fsvq->done_work, virtio_fs_requests_done_work);
|
|
INIT_DELAYED_WORK(&fsvq->dispatch_work,
|
|
virtio_fs_request_dispatch_work);
|
|
} else {
|
|
INIT_WORK(&fsvq->done_work, virtio_fs_hiprio_done_work);
|
|
INIT_DELAYED_WORK(&fsvq->dispatch_work,
|
|
virtio_fs_hiprio_dispatch_work);
|
|
}
|
|
}
|
|
|
|
/* Initialize virtqueues */
|
|
static int virtio_fs_setup_vqs(struct virtio_device *vdev,
|
|
struct virtio_fs *fs)
|
|
{
|
|
struct virtqueue **vqs;
|
|
vq_callback_t **callbacks;
|
|
const char **names;
|
|
unsigned int i;
|
|
int ret = 0;
|
|
|
|
virtio_cread_le(vdev, struct virtio_fs_config, num_request_queues,
|
|
&fs->num_request_queues);
|
|
if (fs->num_request_queues == 0)
|
|
return -EINVAL;
|
|
|
|
fs->nvqs = VQ_REQUEST + fs->num_request_queues;
|
|
fs->vqs = kcalloc(fs->nvqs, sizeof(fs->vqs[VQ_HIPRIO]), GFP_KERNEL);
|
|
if (!fs->vqs)
|
|
return -ENOMEM;
|
|
|
|
vqs = kmalloc_array(fs->nvqs, sizeof(vqs[VQ_HIPRIO]), GFP_KERNEL);
|
|
callbacks = kmalloc_array(fs->nvqs, sizeof(callbacks[VQ_HIPRIO]),
|
|
GFP_KERNEL);
|
|
names = kmalloc_array(fs->nvqs, sizeof(names[VQ_HIPRIO]), GFP_KERNEL);
|
|
if (!vqs || !callbacks || !names) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
|
|
/* Initialize the hiprio/forget request virtqueue */
|
|
callbacks[VQ_HIPRIO] = virtio_fs_vq_done;
|
|
virtio_fs_init_vq(&fs->vqs[VQ_HIPRIO], "hiprio", VQ_HIPRIO);
|
|
names[VQ_HIPRIO] = fs->vqs[VQ_HIPRIO].name;
|
|
|
|
/* Initialize the requests virtqueues */
|
|
for (i = VQ_REQUEST; i < fs->nvqs; i++) {
|
|
char vq_name[VQ_NAME_LEN];
|
|
|
|
snprintf(vq_name, VQ_NAME_LEN, "requests.%u", i - VQ_REQUEST);
|
|
virtio_fs_init_vq(&fs->vqs[i], vq_name, VQ_REQUEST);
|
|
callbacks[i] = virtio_fs_vq_done;
|
|
names[i] = fs->vqs[i].name;
|
|
}
|
|
|
|
ret = virtio_find_vqs(vdev, fs->nvqs, vqs, callbacks, names, NULL);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
for (i = 0; i < fs->nvqs; i++)
|
|
fs->vqs[i].vq = vqs[i];
|
|
|
|
virtio_fs_start_all_queues(fs);
|
|
out:
|
|
kfree(names);
|
|
kfree(callbacks);
|
|
kfree(vqs);
|
|
if (ret)
|
|
kfree(fs->vqs);
|
|
return ret;
|
|
}
|
|
|
|
/* Free virtqueues (device must already be reset) */
|
|
static void virtio_fs_cleanup_vqs(struct virtio_device *vdev)
|
|
{
|
|
vdev->config->del_vqs(vdev);
|
|
}
|
|
|
|
/* Map a window offset to a page frame number. The window offset will have
|
|
* been produced by .iomap_begin(), which maps a file offset to a window
|
|
* offset.
|
|
*/
|
|
static long virtio_fs_direct_access(struct dax_device *dax_dev, pgoff_t pgoff,
|
|
long nr_pages, enum dax_access_mode mode,
|
|
void **kaddr, pfn_t *pfn)
|
|
{
|
|
struct virtio_fs *fs = dax_get_private(dax_dev);
|
|
phys_addr_t offset = PFN_PHYS(pgoff);
|
|
size_t max_nr_pages = fs->window_len / PAGE_SIZE - pgoff;
|
|
|
|
if (kaddr)
|
|
*kaddr = fs->window_kaddr + offset;
|
|
if (pfn)
|
|
*pfn = phys_to_pfn_t(fs->window_phys_addr + offset,
|
|
PFN_DEV | PFN_MAP);
|
|
return nr_pages > max_nr_pages ? max_nr_pages : nr_pages;
|
|
}
|
|
|
|
static int virtio_fs_zero_page_range(struct dax_device *dax_dev,
|
|
pgoff_t pgoff, size_t nr_pages)
|
|
{
|
|
long rc;
|
|
void *kaddr;
|
|
|
|
rc = dax_direct_access(dax_dev, pgoff, nr_pages, DAX_ACCESS, &kaddr,
|
|
NULL);
|
|
if (rc < 0)
|
|
return rc;
|
|
memset(kaddr, 0, nr_pages << PAGE_SHIFT);
|
|
dax_flush(dax_dev, kaddr, nr_pages << PAGE_SHIFT);
|
|
return 0;
|
|
}
|
|
|
|
static const struct dax_operations virtio_fs_dax_ops = {
|
|
.direct_access = virtio_fs_direct_access,
|
|
.zero_page_range = virtio_fs_zero_page_range,
|
|
};
|
|
|
|
static void virtio_fs_cleanup_dax(void *data)
|
|
{
|
|
struct dax_device *dax_dev = data;
|
|
|
|
kill_dax(dax_dev);
|
|
put_dax(dax_dev);
|
|
}
|
|
|
|
static int virtio_fs_setup_dax(struct virtio_device *vdev, struct virtio_fs *fs)
|
|
{
|
|
struct virtio_shm_region cache_reg;
|
|
struct dev_pagemap *pgmap;
|
|
bool have_cache;
|
|
|
|
if (!IS_ENABLED(CONFIG_FUSE_DAX))
|
|
return 0;
|
|
|
|
/* Get cache region */
|
|
have_cache = virtio_get_shm_region(vdev, &cache_reg,
|
|
(u8)VIRTIO_FS_SHMCAP_ID_CACHE);
|
|
if (!have_cache) {
|
|
dev_notice(&vdev->dev, "%s: No cache capability\n", __func__);
|
|
return 0;
|
|
}
|
|
|
|
if (!devm_request_mem_region(&vdev->dev, cache_reg.addr, cache_reg.len,
|
|
dev_name(&vdev->dev))) {
|
|
dev_warn(&vdev->dev, "could not reserve region addr=0x%llx len=0x%llx\n",
|
|
cache_reg.addr, cache_reg.len);
|
|
return -EBUSY;
|
|
}
|
|
|
|
dev_notice(&vdev->dev, "Cache len: 0x%llx @ 0x%llx\n", cache_reg.len,
|
|
cache_reg.addr);
|
|
|
|
pgmap = devm_kzalloc(&vdev->dev, sizeof(*pgmap), GFP_KERNEL);
|
|
if (!pgmap)
|
|
return -ENOMEM;
|
|
|
|
pgmap->type = MEMORY_DEVICE_FS_DAX;
|
|
|
|
/* Ideally we would directly use the PCI BAR resource but
|
|
* devm_memremap_pages() wants its own copy in pgmap. So
|
|
* initialize a struct resource from scratch (only the start
|
|
* and end fields will be used).
|
|
*/
|
|
pgmap->range = (struct range) {
|
|
.start = (phys_addr_t) cache_reg.addr,
|
|
.end = (phys_addr_t) cache_reg.addr + cache_reg.len - 1,
|
|
};
|
|
pgmap->nr_range = 1;
|
|
|
|
fs->window_kaddr = devm_memremap_pages(&vdev->dev, pgmap);
|
|
if (IS_ERR(fs->window_kaddr))
|
|
return PTR_ERR(fs->window_kaddr);
|
|
|
|
fs->window_phys_addr = (phys_addr_t) cache_reg.addr;
|
|
fs->window_len = (phys_addr_t) cache_reg.len;
|
|
|
|
dev_dbg(&vdev->dev, "%s: window kaddr 0x%px phys_addr 0x%llx len 0x%llx\n",
|
|
__func__, fs->window_kaddr, cache_reg.addr, cache_reg.len);
|
|
|
|
fs->dax_dev = alloc_dax(fs, &virtio_fs_dax_ops);
|
|
if (IS_ERR(fs->dax_dev))
|
|
return PTR_ERR(fs->dax_dev);
|
|
|
|
return devm_add_action_or_reset(&vdev->dev, virtio_fs_cleanup_dax,
|
|
fs->dax_dev);
|
|
}
|
|
|
|
static int virtio_fs_probe(struct virtio_device *vdev)
|
|
{
|
|
struct virtio_fs *fs;
|
|
int ret;
|
|
|
|
fs = kzalloc(sizeof(*fs), GFP_KERNEL);
|
|
if (!fs)
|
|
return -ENOMEM;
|
|
kref_init(&fs->refcount);
|
|
vdev->priv = fs;
|
|
|
|
ret = virtio_fs_read_tag(vdev, fs);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
ret = virtio_fs_setup_vqs(vdev, fs);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
/* TODO vq affinity */
|
|
|
|
ret = virtio_fs_setup_dax(vdev, fs);
|
|
if (ret < 0)
|
|
goto out_vqs;
|
|
|
|
/* Bring the device online in case the filesystem is mounted and
|
|
* requests need to be sent before we return.
|
|
*/
|
|
virtio_device_ready(vdev);
|
|
|
|
ret = virtio_fs_add_instance(fs);
|
|
if (ret < 0)
|
|
goto out_vqs;
|
|
|
|
return 0;
|
|
|
|
out_vqs:
|
|
virtio_reset_device(vdev);
|
|
virtio_fs_cleanup_vqs(vdev);
|
|
kfree(fs->vqs);
|
|
|
|
out:
|
|
vdev->priv = NULL;
|
|
kfree(fs);
|
|
return ret;
|
|
}
|
|
|
|
static void virtio_fs_stop_all_queues(struct virtio_fs *fs)
|
|
{
|
|
struct virtio_fs_vq *fsvq;
|
|
int i;
|
|
|
|
for (i = 0; i < fs->nvqs; i++) {
|
|
fsvq = &fs->vqs[i];
|
|
spin_lock(&fsvq->lock);
|
|
fsvq->connected = false;
|
|
spin_unlock(&fsvq->lock);
|
|
}
|
|
}
|
|
|
|
static void virtio_fs_remove(struct virtio_device *vdev)
|
|
{
|
|
struct virtio_fs *fs = vdev->priv;
|
|
|
|
mutex_lock(&virtio_fs_mutex);
|
|
/* This device is going away. No one should get new reference */
|
|
list_del_init(&fs->list);
|
|
virtio_fs_stop_all_queues(fs);
|
|
virtio_fs_drain_all_queues_locked(fs);
|
|
virtio_reset_device(vdev);
|
|
virtio_fs_cleanup_vqs(vdev);
|
|
|
|
vdev->priv = NULL;
|
|
/* Put device reference on virtio_fs object */
|
|
virtio_fs_put(fs);
|
|
mutex_unlock(&virtio_fs_mutex);
|
|
}
|
|
|
|
#ifdef CONFIG_PM_SLEEP
|
|
static int virtio_fs_freeze(struct virtio_device *vdev)
|
|
{
|
|
/* TODO need to save state here */
|
|
pr_warn("virtio-fs: suspend/resume not yet supported\n");
|
|
return -EOPNOTSUPP;
|
|
}
|
|
|
|
static int virtio_fs_restore(struct virtio_device *vdev)
|
|
{
|
|
/* TODO need to restore state here */
|
|
return 0;
|
|
}
|
|
#endif /* CONFIG_PM_SLEEP */
|
|
|
|
static const struct virtio_device_id id_table[] = {
|
|
{ VIRTIO_ID_FS, VIRTIO_DEV_ANY_ID },
|
|
{},
|
|
};
|
|
|
|
static const unsigned int feature_table[] = {};
|
|
|
|
static struct virtio_driver virtio_fs_driver = {
|
|
.driver.name = KBUILD_MODNAME,
|
|
.driver.owner = THIS_MODULE,
|
|
.id_table = id_table,
|
|
.feature_table = feature_table,
|
|
.feature_table_size = ARRAY_SIZE(feature_table),
|
|
.probe = virtio_fs_probe,
|
|
.remove = virtio_fs_remove,
|
|
#ifdef CONFIG_PM_SLEEP
|
|
.freeze = virtio_fs_freeze,
|
|
.restore = virtio_fs_restore,
|
|
#endif
|
|
};
|
|
|
|
static void virtio_fs_wake_forget_and_unlock(struct fuse_iqueue *fiq)
|
|
__releases(fiq->lock)
|
|
{
|
|
struct fuse_forget_link *link;
|
|
struct virtio_fs_forget *forget;
|
|
struct virtio_fs_forget_req *req;
|
|
struct virtio_fs *fs;
|
|
struct virtio_fs_vq *fsvq;
|
|
u64 unique;
|
|
|
|
link = fuse_dequeue_forget(fiq, 1, NULL);
|
|
unique = fuse_get_unique(fiq);
|
|
|
|
fs = fiq->priv;
|
|
fsvq = &fs->vqs[VQ_HIPRIO];
|
|
spin_unlock(&fiq->lock);
|
|
|
|
/* Allocate a buffer for the request */
|
|
forget = kmalloc(sizeof(*forget), GFP_NOFS | __GFP_NOFAIL);
|
|
req = &forget->req;
|
|
|
|
req->ih = (struct fuse_in_header){
|
|
.opcode = FUSE_FORGET,
|
|
.nodeid = link->forget_one.nodeid,
|
|
.unique = unique,
|
|
.len = sizeof(*req),
|
|
};
|
|
req->arg = (struct fuse_forget_in){
|
|
.nlookup = link->forget_one.nlookup,
|
|
};
|
|
|
|
send_forget_request(fsvq, forget, false);
|
|
kfree(link);
|
|
}
|
|
|
|
static void virtio_fs_wake_interrupt_and_unlock(struct fuse_iqueue *fiq)
|
|
__releases(fiq->lock)
|
|
{
|
|
/*
|
|
* TODO interrupts.
|
|
*
|
|
* Normal fs operations on a local filesystems aren't interruptible.
|
|
* Exceptions are blocking lock operations; for example fcntl(F_SETLKW)
|
|
* with shared lock between host and guest.
|
|
*/
|
|
spin_unlock(&fiq->lock);
|
|
}
|
|
|
|
/* Count number of scatter-gather elements required */
|
|
static unsigned int sg_count_fuse_pages(struct fuse_page_desc *page_descs,
|
|
unsigned int num_pages,
|
|
unsigned int total_len)
|
|
{
|
|
unsigned int i;
|
|
unsigned int this_len;
|
|
|
|
for (i = 0; i < num_pages && total_len; i++) {
|
|
this_len = min(page_descs[i].length, total_len);
|
|
total_len -= this_len;
|
|
}
|
|
|
|
return i;
|
|
}
|
|
|
|
/* Return the number of scatter-gather list elements required */
|
|
static unsigned int sg_count_fuse_req(struct fuse_req *req)
|
|
{
|
|
struct fuse_args *args = req->args;
|
|
struct fuse_args_pages *ap = container_of(args, typeof(*ap), args);
|
|
unsigned int size, total_sgs = 1 /* fuse_in_header */;
|
|
|
|
if (args->in_numargs - args->in_pages)
|
|
total_sgs += 1;
|
|
|
|
if (args->in_pages) {
|
|
size = args->in_args[args->in_numargs - 1].size;
|
|
total_sgs += sg_count_fuse_pages(ap->descs, ap->num_pages,
|
|
size);
|
|
}
|
|
|
|
if (!test_bit(FR_ISREPLY, &req->flags))
|
|
return total_sgs;
|
|
|
|
total_sgs += 1 /* fuse_out_header */;
|
|
|
|
if (args->out_numargs - args->out_pages)
|
|
total_sgs += 1;
|
|
|
|
if (args->out_pages) {
|
|
size = args->out_args[args->out_numargs - 1].size;
|
|
total_sgs += sg_count_fuse_pages(ap->descs, ap->num_pages,
|
|
size);
|
|
}
|
|
|
|
return total_sgs;
|
|
}
|
|
|
|
/* Add pages to scatter-gather list and return number of elements used */
|
|
static unsigned int sg_init_fuse_pages(struct scatterlist *sg,
|
|
struct page **pages,
|
|
struct fuse_page_desc *page_descs,
|
|
unsigned int num_pages,
|
|
unsigned int total_len)
|
|
{
|
|
unsigned int i;
|
|
unsigned int this_len;
|
|
|
|
for (i = 0; i < num_pages && total_len; i++) {
|
|
sg_init_table(&sg[i], 1);
|
|
this_len = min(page_descs[i].length, total_len);
|
|
sg_set_page(&sg[i], pages[i], this_len, page_descs[i].offset);
|
|
total_len -= this_len;
|
|
}
|
|
|
|
return i;
|
|
}
|
|
|
|
/* Add args to scatter-gather list and return number of elements used */
|
|
static unsigned int sg_init_fuse_args(struct scatterlist *sg,
|
|
struct fuse_req *req,
|
|
struct fuse_arg *args,
|
|
unsigned int numargs,
|
|
bool argpages,
|
|
void *argbuf,
|
|
unsigned int *len_used)
|
|
{
|
|
struct fuse_args_pages *ap = container_of(req->args, typeof(*ap), args);
|
|
unsigned int total_sgs = 0;
|
|
unsigned int len;
|
|
|
|
len = fuse_len_args(numargs - argpages, args);
|
|
if (len)
|
|
sg_init_one(&sg[total_sgs++], argbuf, len);
|
|
|
|
if (argpages)
|
|
total_sgs += sg_init_fuse_pages(&sg[total_sgs],
|
|
ap->pages, ap->descs,
|
|
ap->num_pages,
|
|
args[numargs - 1].size);
|
|
|
|
if (len_used)
|
|
*len_used = len;
|
|
|
|
return total_sgs;
|
|
}
|
|
|
|
/* Add a request to a virtqueue and kick the device */
|
|
static int virtio_fs_enqueue_req(struct virtio_fs_vq *fsvq,
|
|
struct fuse_req *req, bool in_flight)
|
|
{
|
|
/* requests need at least 4 elements */
|
|
struct scatterlist *stack_sgs[6];
|
|
struct scatterlist stack_sg[ARRAY_SIZE(stack_sgs)];
|
|
struct scatterlist **sgs = stack_sgs;
|
|
struct scatterlist *sg = stack_sg;
|
|
struct virtqueue *vq;
|
|
struct fuse_args *args = req->args;
|
|
unsigned int argbuf_used = 0;
|
|
unsigned int out_sgs = 0;
|
|
unsigned int in_sgs = 0;
|
|
unsigned int total_sgs;
|
|
unsigned int i;
|
|
int ret;
|
|
bool notify;
|
|
struct fuse_pqueue *fpq;
|
|
|
|
/* Does the sglist fit on the stack? */
|
|
total_sgs = sg_count_fuse_req(req);
|
|
if (total_sgs > ARRAY_SIZE(stack_sgs)) {
|
|
sgs = kmalloc_array(total_sgs, sizeof(sgs[0]), GFP_ATOMIC);
|
|
sg = kmalloc_array(total_sgs, sizeof(sg[0]), GFP_ATOMIC);
|
|
if (!sgs || !sg) {
|
|
ret = -ENOMEM;
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
/* Use a bounce buffer since stack args cannot be mapped */
|
|
ret = copy_args_to_argbuf(req);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
/* Request elements */
|
|
sg_init_one(&sg[out_sgs++], &req->in.h, sizeof(req->in.h));
|
|
out_sgs += sg_init_fuse_args(&sg[out_sgs], req,
|
|
(struct fuse_arg *)args->in_args,
|
|
args->in_numargs, args->in_pages,
|
|
req->argbuf, &argbuf_used);
|
|
|
|
/* Reply elements */
|
|
if (test_bit(FR_ISREPLY, &req->flags)) {
|
|
sg_init_one(&sg[out_sgs + in_sgs++],
|
|
&req->out.h, sizeof(req->out.h));
|
|
in_sgs += sg_init_fuse_args(&sg[out_sgs + in_sgs], req,
|
|
args->out_args, args->out_numargs,
|
|
args->out_pages,
|
|
req->argbuf + argbuf_used, NULL);
|
|
}
|
|
|
|
WARN_ON(out_sgs + in_sgs != total_sgs);
|
|
|
|
for (i = 0; i < total_sgs; i++)
|
|
sgs[i] = &sg[i];
|
|
|
|
spin_lock(&fsvq->lock);
|
|
|
|
if (!fsvq->connected) {
|
|
spin_unlock(&fsvq->lock);
|
|
ret = -ENOTCONN;
|
|
goto out;
|
|
}
|
|
|
|
vq = fsvq->vq;
|
|
ret = virtqueue_add_sgs(vq, sgs, out_sgs, in_sgs, req, GFP_ATOMIC);
|
|
if (ret < 0) {
|
|
spin_unlock(&fsvq->lock);
|
|
goto out;
|
|
}
|
|
|
|
/* Request successfully sent. */
|
|
fpq = &fsvq->fud->pq;
|
|
spin_lock(&fpq->lock);
|
|
list_add_tail(&req->list, fpq->processing);
|
|
spin_unlock(&fpq->lock);
|
|
set_bit(FR_SENT, &req->flags);
|
|
/* matches barrier in request_wait_answer() */
|
|
smp_mb__after_atomic();
|
|
|
|
if (!in_flight)
|
|
inc_in_flight_req(fsvq);
|
|
notify = virtqueue_kick_prepare(vq);
|
|
|
|
spin_unlock(&fsvq->lock);
|
|
|
|
if (notify)
|
|
virtqueue_notify(vq);
|
|
|
|
out:
|
|
if (ret < 0 && req->argbuf) {
|
|
kfree(req->argbuf);
|
|
req->argbuf = NULL;
|
|
}
|
|
if (sgs != stack_sgs) {
|
|
kfree(sgs);
|
|
kfree(sg);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void virtio_fs_wake_pending_and_unlock(struct fuse_iqueue *fiq)
|
|
__releases(fiq->lock)
|
|
{
|
|
unsigned int queue_id = VQ_REQUEST; /* TODO multiqueue */
|
|
struct virtio_fs *fs;
|
|
struct fuse_req *req;
|
|
struct virtio_fs_vq *fsvq;
|
|
int ret;
|
|
|
|
WARN_ON(list_empty(&fiq->pending));
|
|
req = list_last_entry(&fiq->pending, struct fuse_req, list);
|
|
clear_bit(FR_PENDING, &req->flags);
|
|
list_del_init(&req->list);
|
|
WARN_ON(!list_empty(&fiq->pending));
|
|
spin_unlock(&fiq->lock);
|
|
|
|
fs = fiq->priv;
|
|
|
|
pr_debug("%s: opcode %u unique %#llx nodeid %#llx in.len %u out.len %u\n",
|
|
__func__, req->in.h.opcode, req->in.h.unique,
|
|
req->in.h.nodeid, req->in.h.len,
|
|
fuse_len_args(req->args->out_numargs, req->args->out_args));
|
|
|
|
fsvq = &fs->vqs[queue_id];
|
|
ret = virtio_fs_enqueue_req(fsvq, req, false);
|
|
if (ret < 0) {
|
|
if (ret == -ENOMEM || ret == -ENOSPC) {
|
|
/*
|
|
* Virtqueue full. Retry submission from worker
|
|
* context as we might be holding fc->bg_lock.
|
|
*/
|
|
spin_lock(&fsvq->lock);
|
|
list_add_tail(&req->list, &fsvq->queued_reqs);
|
|
inc_in_flight_req(fsvq);
|
|
schedule_delayed_work(&fsvq->dispatch_work,
|
|
msecs_to_jiffies(1));
|
|
spin_unlock(&fsvq->lock);
|
|
return;
|
|
}
|
|
req->out.h.error = ret;
|
|
pr_err("virtio-fs: virtio_fs_enqueue_req() failed %d\n", ret);
|
|
|
|
/* Can't end request in submission context. Use a worker */
|
|
spin_lock(&fsvq->lock);
|
|
list_add_tail(&req->list, &fsvq->end_reqs);
|
|
schedule_delayed_work(&fsvq->dispatch_work, 0);
|
|
spin_unlock(&fsvq->lock);
|
|
return;
|
|
}
|
|
}
|
|
|
|
static const struct fuse_iqueue_ops virtio_fs_fiq_ops = {
|
|
.wake_forget_and_unlock = virtio_fs_wake_forget_and_unlock,
|
|
.wake_interrupt_and_unlock = virtio_fs_wake_interrupt_and_unlock,
|
|
.wake_pending_and_unlock = virtio_fs_wake_pending_and_unlock,
|
|
.release = virtio_fs_fiq_release,
|
|
};
|
|
|
|
static inline void virtio_fs_ctx_set_defaults(struct fuse_fs_context *ctx)
|
|
{
|
|
ctx->rootmode = S_IFDIR;
|
|
ctx->default_permissions = 1;
|
|
ctx->allow_other = 1;
|
|
ctx->max_read = UINT_MAX;
|
|
ctx->blksize = 512;
|
|
ctx->destroy = true;
|
|
ctx->no_control = true;
|
|
ctx->no_force_umount = true;
|
|
}
|
|
|
|
static int virtio_fs_fill_super(struct super_block *sb, struct fs_context *fsc)
|
|
{
|
|
struct fuse_mount *fm = get_fuse_mount_super(sb);
|
|
struct fuse_conn *fc = fm->fc;
|
|
struct virtio_fs *fs = fc->iq.priv;
|
|
struct fuse_fs_context *ctx = fsc->fs_private;
|
|
unsigned int i;
|
|
int err;
|
|
|
|
virtio_fs_ctx_set_defaults(ctx);
|
|
mutex_lock(&virtio_fs_mutex);
|
|
|
|
/* After holding mutex, make sure virtiofs device is still there.
|
|
* Though we are holding a reference to it, drive ->remove might
|
|
* still have cleaned up virtual queues. In that case bail out.
|
|
*/
|
|
err = -EINVAL;
|
|
if (list_empty(&fs->list)) {
|
|
pr_info("virtio-fs: tag <%s> not found\n", fs->tag);
|
|
goto err;
|
|
}
|
|
|
|
err = -ENOMEM;
|
|
/* Allocate fuse_dev for hiprio and notification queues */
|
|
for (i = 0; i < fs->nvqs; i++) {
|
|
struct virtio_fs_vq *fsvq = &fs->vqs[i];
|
|
|
|
fsvq->fud = fuse_dev_alloc();
|
|
if (!fsvq->fud)
|
|
goto err_free_fuse_devs;
|
|
}
|
|
|
|
/* virtiofs allocates and installs its own fuse devices */
|
|
ctx->fudptr = NULL;
|
|
if (ctx->dax_mode != FUSE_DAX_NEVER) {
|
|
if (ctx->dax_mode == FUSE_DAX_ALWAYS && !fs->dax_dev) {
|
|
err = -EINVAL;
|
|
pr_err("virtio-fs: dax can't be enabled as filesystem"
|
|
" device does not support it.\n");
|
|
goto err_free_fuse_devs;
|
|
}
|
|
ctx->dax_dev = fs->dax_dev;
|
|
}
|
|
err = fuse_fill_super_common(sb, ctx);
|
|
if (err < 0)
|
|
goto err_free_fuse_devs;
|
|
|
|
for (i = 0; i < fs->nvqs; i++) {
|
|
struct virtio_fs_vq *fsvq = &fs->vqs[i];
|
|
|
|
fuse_dev_install(fsvq->fud, fc);
|
|
}
|
|
|
|
/* Previous unmount will stop all queues. Start these again */
|
|
virtio_fs_start_all_queues(fs);
|
|
fuse_send_init(fm);
|
|
mutex_unlock(&virtio_fs_mutex);
|
|
return 0;
|
|
|
|
err_free_fuse_devs:
|
|
virtio_fs_free_devs(fs);
|
|
err:
|
|
mutex_unlock(&virtio_fs_mutex);
|
|
return err;
|
|
}
|
|
|
|
static void virtio_fs_conn_destroy(struct fuse_mount *fm)
|
|
{
|
|
struct fuse_conn *fc = fm->fc;
|
|
struct virtio_fs *vfs = fc->iq.priv;
|
|
struct virtio_fs_vq *fsvq = &vfs->vqs[VQ_HIPRIO];
|
|
|
|
/* Stop dax worker. Soon evict_inodes() will be called which
|
|
* will free all memory ranges belonging to all inodes.
|
|
*/
|
|
if (IS_ENABLED(CONFIG_FUSE_DAX))
|
|
fuse_dax_cancel_work(fc);
|
|
|
|
/* Stop forget queue. Soon destroy will be sent */
|
|
spin_lock(&fsvq->lock);
|
|
fsvq->connected = false;
|
|
spin_unlock(&fsvq->lock);
|
|
virtio_fs_drain_all_queues(vfs);
|
|
|
|
fuse_conn_destroy(fm);
|
|
|
|
/* fuse_conn_destroy() must have sent destroy. Stop all queues
|
|
* and drain one more time and free fuse devices. Freeing fuse
|
|
* devices will drop their reference on fuse_conn and that in
|
|
* turn will drop its reference on virtio_fs object.
|
|
*/
|
|
virtio_fs_stop_all_queues(vfs);
|
|
virtio_fs_drain_all_queues(vfs);
|
|
virtio_fs_free_devs(vfs);
|
|
}
|
|
|
|
static void virtio_kill_sb(struct super_block *sb)
|
|
{
|
|
struct fuse_mount *fm = get_fuse_mount_super(sb);
|
|
bool last;
|
|
|
|
/* If mount failed, we can still be called without any fc */
|
|
if (sb->s_root) {
|
|
last = fuse_mount_remove(fm);
|
|
if (last)
|
|
virtio_fs_conn_destroy(fm);
|
|
}
|
|
kill_anon_super(sb);
|
|
fuse_mount_destroy(fm);
|
|
}
|
|
|
|
static int virtio_fs_test_super(struct super_block *sb,
|
|
struct fs_context *fsc)
|
|
{
|
|
struct fuse_mount *fsc_fm = fsc->s_fs_info;
|
|
struct fuse_mount *sb_fm = get_fuse_mount_super(sb);
|
|
|
|
return fsc_fm->fc->iq.priv == sb_fm->fc->iq.priv;
|
|
}
|
|
|
|
static int virtio_fs_get_tree(struct fs_context *fsc)
|
|
{
|
|
struct virtio_fs *fs;
|
|
struct super_block *sb;
|
|
struct fuse_conn *fc = NULL;
|
|
struct fuse_mount *fm;
|
|
unsigned int virtqueue_size;
|
|
int err = -EIO;
|
|
|
|
/* This gets a reference on virtio_fs object. This ptr gets installed
|
|
* in fc->iq->priv. Once fuse_conn is going away, it calls ->put()
|
|
* to drop the reference to this object.
|
|
*/
|
|
fs = virtio_fs_find_instance(fsc->source);
|
|
if (!fs) {
|
|
pr_info("virtio-fs: tag <%s> not found\n", fsc->source);
|
|
return -EINVAL;
|
|
}
|
|
|
|
virtqueue_size = virtqueue_get_vring_size(fs->vqs[VQ_REQUEST].vq);
|
|
if (WARN_ON(virtqueue_size <= FUSE_HEADER_OVERHEAD))
|
|
goto out_err;
|
|
|
|
err = -ENOMEM;
|
|
fc = kzalloc(sizeof(struct fuse_conn), GFP_KERNEL);
|
|
if (!fc)
|
|
goto out_err;
|
|
|
|
fm = kzalloc(sizeof(struct fuse_mount), GFP_KERNEL);
|
|
if (!fm)
|
|
goto out_err;
|
|
|
|
fuse_conn_init(fc, fm, fsc->user_ns, &virtio_fs_fiq_ops, fs);
|
|
fc->release = fuse_free_conn;
|
|
fc->delete_stale = true;
|
|
fc->auto_submounts = true;
|
|
fc->sync_fs = true;
|
|
|
|
/* Tell FUSE to split requests that exceed the virtqueue's size */
|
|
fc->max_pages_limit = min_t(unsigned int, fc->max_pages_limit,
|
|
virtqueue_size - FUSE_HEADER_OVERHEAD);
|
|
|
|
fsc->s_fs_info = fm;
|
|
sb = sget_fc(fsc, virtio_fs_test_super, set_anon_super_fc);
|
|
if (fsc->s_fs_info)
|
|
fuse_mount_destroy(fm);
|
|
if (IS_ERR(sb))
|
|
return PTR_ERR(sb);
|
|
|
|
if (!sb->s_root) {
|
|
err = virtio_fs_fill_super(sb, fsc);
|
|
if (err) {
|
|
deactivate_locked_super(sb);
|
|
return err;
|
|
}
|
|
|
|
sb->s_flags |= SB_ACTIVE;
|
|
}
|
|
|
|
WARN_ON(fsc->root);
|
|
fsc->root = dget(sb->s_root);
|
|
return 0;
|
|
|
|
out_err:
|
|
kfree(fc);
|
|
mutex_lock(&virtio_fs_mutex);
|
|
virtio_fs_put(fs);
|
|
mutex_unlock(&virtio_fs_mutex);
|
|
return err;
|
|
}
|
|
|
|
static const struct fs_context_operations virtio_fs_context_ops = {
|
|
.free = virtio_fs_free_fsc,
|
|
.parse_param = virtio_fs_parse_param,
|
|
.get_tree = virtio_fs_get_tree,
|
|
};
|
|
|
|
static int virtio_fs_init_fs_context(struct fs_context *fsc)
|
|
{
|
|
struct fuse_fs_context *ctx;
|
|
|
|
if (fsc->purpose == FS_CONTEXT_FOR_SUBMOUNT)
|
|
return fuse_init_fs_context_submount(fsc);
|
|
|
|
ctx = kzalloc(sizeof(struct fuse_fs_context), GFP_KERNEL);
|
|
if (!ctx)
|
|
return -ENOMEM;
|
|
fsc->fs_private = ctx;
|
|
fsc->ops = &virtio_fs_context_ops;
|
|
return 0;
|
|
}
|
|
|
|
static struct file_system_type virtio_fs_type = {
|
|
.owner = THIS_MODULE,
|
|
.name = "virtiofs",
|
|
.init_fs_context = virtio_fs_init_fs_context,
|
|
.kill_sb = virtio_kill_sb,
|
|
};
|
|
|
|
static int __init virtio_fs_init(void)
|
|
{
|
|
int ret;
|
|
|
|
ret = register_virtio_driver(&virtio_fs_driver);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
ret = register_filesystem(&virtio_fs_type);
|
|
if (ret < 0) {
|
|
unregister_virtio_driver(&virtio_fs_driver);
|
|
return ret;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
module_init(virtio_fs_init);
|
|
|
|
static void __exit virtio_fs_exit(void)
|
|
{
|
|
unregister_filesystem(&virtio_fs_type);
|
|
unregister_virtio_driver(&virtio_fs_driver);
|
|
}
|
|
module_exit(virtio_fs_exit);
|
|
|
|
MODULE_AUTHOR("Stefan Hajnoczi <stefanha@redhat.com>");
|
|
MODULE_DESCRIPTION("Virtio Filesystem");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS_FS(KBUILD_MODNAME);
|
|
MODULE_DEVICE_TABLE(virtio, id_table);
|